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10a0d495 | 1 | /* __builtin_object_size (ptr, object_size_type) computation |
5624e564 | 2 | Copyright (C) 2004-2015 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 AM |
26 | #include "gimple.h" |
27 | #include "hard-reg-set.h" | |
28 | #include "ssa.h" | |
29 | #include "alias.h" | |
40e23961 | 30 | #include "fold-const.h" |
d8a2d370 | 31 | #include "tree-object-size.h" |
718f9c0f | 32 | #include "diagnostic-core.h" |
cf835838 | 33 | #include "gimple-pretty-print.h" |
2fb9a547 AM |
34 | #include "internal-fn.h" |
35 | #include "gimple-fold.h" | |
5be5c238 | 36 | #include "gimple-iterator.h" |
10a0d495 JJ |
37 | #include "tree-pass.h" |
38 | #include "tree-ssa-propagate.h" | |
9b2b7279 | 39 | #include "builtins.h" |
10a0d495 JJ |
40 | |
41 | struct object_size_info | |
42 | { | |
43 | int object_size_type; | |
44 | bitmap visited, reexamine; | |
45 | int pass; | |
46 | bool changed; | |
47 | unsigned int *depths; | |
48 | unsigned int *stack, *tos; | |
49 | }; | |
50 | ||
4cdce1a8 | 51 | static const unsigned HOST_WIDE_INT unknown[4] = { -1, -1, 0, 0 }; |
10a0d495 | 52 | |
ac545c64 | 53 | static tree compute_object_offset (const_tree, const_tree); |
eb9ed98a JJ |
54 | static unsigned HOST_WIDE_INT addr_object_size (struct object_size_info *, |
55 | const_tree, int); | |
538dd0b7 DM |
56 | static unsigned HOST_WIDE_INT alloc_object_size (const gcall *, int); |
57 | static tree pass_through_call (const gcall *); | |
10a0d495 JJ |
58 | static void collect_object_sizes_for (struct object_size_info *, tree); |
59 | static void expr_object_size (struct object_size_info *, tree, tree); | |
60 | static bool merge_object_sizes (struct object_size_info *, tree, tree, | |
61 | unsigned HOST_WIDE_INT); | |
726a989a | 62 | static bool plus_stmt_object_size (struct object_size_info *, tree, gimple); |
4e71066d | 63 | static bool cond_expr_object_size (struct object_size_info *, tree, gimple); |
10a0d495 JJ |
64 | static void init_offset_limit (void); |
65 | static void check_for_plus_in_loops (struct object_size_info *, tree); | |
66 | static void check_for_plus_in_loops_1 (struct object_size_info *, tree, | |
67 | unsigned int); | |
68 | ||
69 | /* object_sizes[0] is upper bound for number of bytes till the end of | |
70 | the object. | |
71 | object_sizes[1] is upper bound for number of bytes till the end of | |
72 | the subobject (innermost array or field with address taken). | |
73 | object_sizes[2] is lower bound for number of bytes till the end of | |
74 | the object and object_sizes[3] lower bound for subobject. */ | |
db84d11e | 75 | static vec<unsigned HOST_WIDE_INT> object_sizes[4]; |
10a0d495 JJ |
76 | |
77 | /* Bitmaps what object sizes have been computed already. */ | |
78 | static bitmap computed[4]; | |
79 | ||
80 | /* Maximum value of offset we consider to be addition. */ | |
81 | static unsigned HOST_WIDE_INT offset_limit; | |
82 | ||
83 | ||
84 | /* Initialize OFFSET_LIMIT variable. */ | |
85 | static void | |
86 | init_offset_limit (void) | |
87 | { | |
cc269bb6 | 88 | if (tree_fits_uhwi_p (TYPE_MAX_VALUE (sizetype))) |
ae7e9ddd | 89 | offset_limit = tree_to_uhwi (TYPE_MAX_VALUE (sizetype)); |
10a0d495 JJ |
90 | else |
91 | offset_limit = -1; | |
92 | offset_limit /= 2; | |
93 | } | |
94 | ||
95 | ||
96 | /* Compute offset of EXPR within VAR. Return error_mark_node | |
97 | if unknown. */ | |
98 | ||
99 | static tree | |
ac545c64 | 100 | compute_object_offset (const_tree expr, const_tree var) |
10a0d495 JJ |
101 | { |
102 | enum tree_code code = PLUS_EXPR; | |
103 | tree base, off, t; | |
104 | ||
105 | if (expr == var) | |
106 | return size_zero_node; | |
107 | ||
108 | switch (TREE_CODE (expr)) | |
109 | { | |
110 | case COMPONENT_REF: | |
111 | base = compute_object_offset (TREE_OPERAND (expr, 0), var); | |
112 | if (base == error_mark_node) | |
113 | return base; | |
114 | ||
115 | t = TREE_OPERAND (expr, 1); | |
116 | off = size_binop (PLUS_EXPR, DECL_FIELD_OFFSET (t), | |
ae7e9ddd | 117 | size_int (tree_to_uhwi (DECL_FIELD_BIT_OFFSET (t)) |
10a0d495 JJ |
118 | / BITS_PER_UNIT)); |
119 | break; | |
120 | ||
121 | case REALPART_EXPR: | |
1043771b | 122 | CASE_CONVERT: |
10a0d495 JJ |
123 | case VIEW_CONVERT_EXPR: |
124 | case NON_LVALUE_EXPR: | |
125 | return compute_object_offset (TREE_OPERAND (expr, 0), var); | |
126 | ||
127 | case IMAGPART_EXPR: | |
128 | base = compute_object_offset (TREE_OPERAND (expr, 0), var); | |
129 | if (base == error_mark_node) | |
130 | return base; | |
131 | ||
132 | off = TYPE_SIZE_UNIT (TREE_TYPE (expr)); | |
133 | break; | |
134 | ||
135 | case ARRAY_REF: | |
136 | base = compute_object_offset (TREE_OPERAND (expr, 0), var); | |
137 | if (base == error_mark_node) | |
138 | return base; | |
139 | ||
140 | t = TREE_OPERAND (expr, 1); | |
141 | if (TREE_CODE (t) == INTEGER_CST && tree_int_cst_sgn (t) < 0) | |
142 | { | |
143 | code = MINUS_EXPR; | |
144 | t = fold_build1 (NEGATE_EXPR, TREE_TYPE (t), t); | |
145 | } | |
b6f65e3c | 146 | t = fold_convert (sizetype, t); |
10a0d495 JJ |
147 | off = size_binop (MULT_EXPR, TYPE_SIZE_UNIT (TREE_TYPE (expr)), t); |
148 | break; | |
149 | ||
70f34814 RG |
150 | case MEM_REF: |
151 | gcc_assert (TREE_CODE (TREE_OPERAND (expr, 0)) == ADDR_EXPR); | |
807e902e | 152 | return wide_int_to_tree (sizetype, mem_ref_offset (expr)); |
70f34814 | 153 | |
10a0d495 JJ |
154 | default: |
155 | return error_mark_node; | |
156 | } | |
157 | ||
158 | return size_binop (code, base, off); | |
159 | } | |
160 | ||
161 | ||
162 | /* Compute __builtin_object_size for PTR, which is a ADDR_EXPR. | |
163 | OBJECT_SIZE_TYPE is the second argument from __builtin_object_size. | |
164 | If unknown, return unknown[object_size_type]. */ | |
165 | ||
166 | static unsigned HOST_WIDE_INT | |
eb9ed98a JJ |
167 | addr_object_size (struct object_size_info *osi, const_tree ptr, |
168 | int object_size_type) | |
10a0d495 | 169 | { |
eb9ed98a | 170 | tree pt_var, pt_var_size = NULL_TREE, var_size, bytes; |
10a0d495 JJ |
171 | |
172 | gcc_assert (TREE_CODE (ptr) == ADDR_EXPR); | |
173 | ||
174 | pt_var = TREE_OPERAND (ptr, 0); | |
d837d73d RG |
175 | while (handled_component_p (pt_var)) |
176 | pt_var = TREE_OPERAND (pt_var, 0); | |
10a0d495 JJ |
177 | |
178 | if (pt_var | |
d837d73d | 179 | && TREE_CODE (pt_var) == MEM_REF) |
10a0d495 | 180 | { |
eb9ed98a | 181 | unsigned HOST_WIDE_INT sz; |
10a0d495 | 182 | |
d837d73d | 183 | if (!osi || (object_size_type & 1) != 0 |
ea17de23 | 184 | || TREE_CODE (TREE_OPERAND (pt_var, 0)) != SSA_NAME) |
70f34814 RG |
185 | { |
186 | sz = compute_builtin_object_size (TREE_OPERAND (pt_var, 0), | |
187 | object_size_type & ~1); | |
70f34814 | 188 | } |
eb9ed98a | 189 | else |
10a0d495 | 190 | { |
eb9ed98a JJ |
191 | tree var = TREE_OPERAND (pt_var, 0); |
192 | if (osi->pass == 0) | |
193 | collect_object_sizes_for (osi, var); | |
194 | if (bitmap_bit_p (computed[object_size_type], | |
195 | SSA_NAME_VERSION (var))) | |
196 | sz = object_sizes[object_size_type][SSA_NAME_VERSION (var)]; | |
197 | else | |
198 | sz = unknown[object_size_type]; | |
d837d73d RG |
199 | } |
200 | if (sz != unknown[object_size_type]) | |
201 | { | |
807e902e KZ |
202 | offset_int dsz = wi::sub (sz, mem_ref_offset (pt_var)); |
203 | if (wi::neg_p (dsz)) | |
d837d73d | 204 | sz = 0; |
807e902e | 205 | else if (wi::fits_uhwi_p (dsz)) |
27bcd47c | 206 | sz = dsz.to_uhwi (); |
70f34814 | 207 | else |
d837d73d | 208 | sz = unknown[object_size_type]; |
eb9ed98a JJ |
209 | } |
210 | ||
211 | if (sz != unknown[object_size_type] && sz < offset_limit) | |
212 | pt_var_size = size_int (sz); | |
213 | } | |
e497b9bd RG |
214 | else if (pt_var |
215 | && DECL_P (pt_var) | |
cc269bb6 | 216 | && tree_fits_uhwi_p (DECL_SIZE_UNIT (pt_var)) |
7d362f6c | 217 | && tree_to_uhwi (DECL_SIZE_UNIT (pt_var)) < offset_limit) |
e497b9bd | 218 | pt_var_size = DECL_SIZE_UNIT (pt_var); |
eb9ed98a | 219 | else if (pt_var |
d837d73d | 220 | && TREE_CODE (pt_var) == STRING_CST |
eb9ed98a | 221 | && TYPE_SIZE_UNIT (TREE_TYPE (pt_var)) |
cc269bb6 | 222 | && tree_fits_uhwi_p (TYPE_SIZE_UNIT (TREE_TYPE (pt_var))) |
7d362f6c | 223 | && tree_to_uhwi (TYPE_SIZE_UNIT (TREE_TYPE (pt_var))) |
eb9ed98a JJ |
224 | < offset_limit) |
225 | pt_var_size = TYPE_SIZE_UNIT (TREE_TYPE (pt_var)); | |
226 | else | |
227 | return unknown[object_size_type]; | |
228 | ||
229 | if (pt_var != TREE_OPERAND (ptr, 0)) | |
230 | { | |
231 | tree var; | |
10a0d495 | 232 | |
eb9ed98a JJ |
233 | if (object_size_type & 1) |
234 | { | |
235 | var = TREE_OPERAND (ptr, 0); | |
236 | ||
237 | while (var != pt_var | |
238 | && TREE_CODE (var) != BIT_FIELD_REF | |
239 | && TREE_CODE (var) != COMPONENT_REF | |
240 | && TREE_CODE (var) != ARRAY_REF | |
241 | && TREE_CODE (var) != ARRAY_RANGE_REF | |
242 | && TREE_CODE (var) != REALPART_EXPR | |
243 | && TREE_CODE (var) != IMAGPART_EXPR) | |
244 | var = TREE_OPERAND (var, 0); | |
245 | if (var != pt_var && TREE_CODE (var) == ARRAY_REF) | |
38027156 | 246 | var = TREE_OPERAND (var, 0); |
eb9ed98a | 247 | if (! TYPE_SIZE_UNIT (TREE_TYPE (var)) |
cc269bb6 | 248 | || ! tree_fits_uhwi_p (TYPE_SIZE_UNIT (TREE_TYPE (var))) |
eb9ed98a JJ |
249 | || (pt_var_size |
250 | && tree_int_cst_lt (pt_var_size, | |
251 | TYPE_SIZE_UNIT (TREE_TYPE (var))))) | |
252 | var = pt_var; | |
70f34814 | 253 | else if (var != pt_var && TREE_CODE (pt_var) == MEM_REF) |
10a0d495 | 254 | { |
eb9ed98a JJ |
255 | tree v = var; |
256 | /* For &X->fld, compute object size only if fld isn't the last | |
257 | field, as struct { int i; char c[1]; } is often used instead | |
258 | of flexible array member. */ | |
259 | while (v && v != pt_var) | |
260 | switch (TREE_CODE (v)) | |
261 | { | |
262 | case ARRAY_REF: | |
263 | if (TYPE_SIZE_UNIT (TREE_TYPE (TREE_OPERAND (v, 0))) | |
264 | && TREE_CODE (TREE_OPERAND (v, 1)) == INTEGER_CST) | |
265 | { | |
266 | tree domain | |
267 | = TYPE_DOMAIN (TREE_TYPE (TREE_OPERAND (v, 0))); | |
268 | if (domain | |
269 | && TYPE_MAX_VALUE (domain) | |
270 | && TREE_CODE (TYPE_MAX_VALUE (domain)) | |
271 | == INTEGER_CST | |
272 | && tree_int_cst_lt (TREE_OPERAND (v, 1), | |
273 | TYPE_MAX_VALUE (domain))) | |
274 | { | |
275 | v = NULL_TREE; | |
276 | break; | |
277 | } | |
278 | } | |
279 | v = TREE_OPERAND (v, 0); | |
280 | break; | |
281 | case REALPART_EXPR: | |
282 | case IMAGPART_EXPR: | |
283 | v = NULL_TREE; | |
284 | break; | |
285 | case COMPONENT_REF: | |
8593e0b6 JJ |
286 | if (TREE_CODE (TREE_TYPE (v)) != ARRAY_TYPE) |
287 | { | |
288 | v = NULL_TREE; | |
289 | break; | |
290 | } | |
38027156 JJ |
291 | while (v != pt_var && TREE_CODE (v) == COMPONENT_REF) |
292 | if (TREE_CODE (TREE_TYPE (TREE_OPERAND (v, 0))) | |
293 | != UNION_TYPE | |
294 | && TREE_CODE (TREE_TYPE (TREE_OPERAND (v, 0))) | |
295 | != QUAL_UNION_TYPE) | |
296 | break; | |
297 | else | |
298 | v = TREE_OPERAND (v, 0); | |
299 | if (TREE_CODE (v) == COMPONENT_REF | |
300 | && TREE_CODE (TREE_TYPE (TREE_OPERAND (v, 0))) | |
301 | == RECORD_TYPE) | |
eb9ed98a | 302 | { |
910ad8de NF |
303 | tree fld_chain = DECL_CHAIN (TREE_OPERAND (v, 1)); |
304 | for (; fld_chain; fld_chain = DECL_CHAIN (fld_chain)) | |
8593e0b6 JJ |
305 | if (TREE_CODE (fld_chain) == FIELD_DECL) |
306 | break; | |
307 | ||
308 | if (fld_chain) | |
309 | { | |
310 | v = NULL_TREE; | |
eb9ed98a | 311 | break; |
8593e0b6 | 312 | } |
38027156 | 313 | v = TREE_OPERAND (v, 0); |
eb9ed98a | 314 | } |
38027156 JJ |
315 | while (v != pt_var && TREE_CODE (v) == COMPONENT_REF) |
316 | if (TREE_CODE (TREE_TYPE (TREE_OPERAND (v, 0))) | |
317 | != UNION_TYPE | |
318 | && TREE_CODE (TREE_TYPE (TREE_OPERAND (v, 0))) | |
319 | != QUAL_UNION_TYPE) | |
8593e0b6 JJ |
320 | break; |
321 | else | |
322 | v = TREE_OPERAND (v, 0); | |
38027156 | 323 | if (v != pt_var) |
8593e0b6 JJ |
324 | v = NULL_TREE; |
325 | else | |
326 | v = pt_var; | |
eb9ed98a JJ |
327 | break; |
328 | default: | |
329 | v = pt_var; | |
330 | break; | |
331 | } | |
332 | if (v == pt_var) | |
10a0d495 JJ |
333 | var = pt_var; |
334 | } | |
eb9ed98a JJ |
335 | } |
336 | else | |
337 | var = pt_var; | |
10a0d495 | 338 | |
eb9ed98a JJ |
339 | if (var != pt_var) |
340 | var_size = TYPE_SIZE_UNIT (TREE_TYPE (var)); | |
341 | else if (!pt_var_size) | |
342 | return unknown[object_size_type]; | |
343 | else | |
344 | var_size = pt_var_size; | |
345 | bytes = compute_object_offset (TREE_OPERAND (ptr, 0), var); | |
346 | if (bytes != error_mark_node) | |
347 | { | |
348 | if (TREE_CODE (bytes) == INTEGER_CST | |
349 | && tree_int_cst_lt (var_size, bytes)) | |
350 | bytes = size_zero_node; | |
351 | else | |
352 | bytes = size_binop (MINUS_EXPR, var_size, bytes); | |
353 | } | |
354 | if (var != pt_var | |
355 | && pt_var_size | |
70f34814 | 356 | && TREE_CODE (pt_var) == MEM_REF |
eb9ed98a JJ |
357 | && bytes != error_mark_node) |
358 | { | |
359 | tree bytes2 = compute_object_offset (TREE_OPERAND (ptr, 0), pt_var); | |
360 | if (bytes2 != error_mark_node) | |
10a0d495 | 361 | { |
eb9ed98a JJ |
362 | if (TREE_CODE (bytes2) == INTEGER_CST |
363 | && tree_int_cst_lt (pt_var_size, bytes2)) | |
364 | bytes2 = size_zero_node; | |
10a0d495 | 365 | else |
98a129b9 | 366 | bytes2 = size_binop (MINUS_EXPR, pt_var_size, bytes2); |
eb9ed98a | 367 | bytes = size_binop (MIN_EXPR, bytes, bytes2); |
10a0d495 JJ |
368 | } |
369 | } | |
10a0d495 | 370 | } |
eb9ed98a JJ |
371 | else if (!pt_var_size) |
372 | return unknown[object_size_type]; | |
373 | else | |
374 | bytes = pt_var_size; | |
375 | ||
cc269bb6 | 376 | if (tree_fits_uhwi_p (bytes)) |
ae7e9ddd | 377 | return tree_to_uhwi (bytes); |
10a0d495 JJ |
378 | |
379 | return unknown[object_size_type]; | |
380 | } | |
381 | ||
382 | ||
726a989a | 383 | /* Compute __builtin_object_size for CALL, which is a GIMPLE_CALL. |
10a0d495 JJ |
384 | Handles various allocation calls. OBJECT_SIZE_TYPE is the second |
385 | argument from __builtin_object_size. If unknown, return | |
386 | unknown[object_size_type]. */ | |
387 | ||
388 | static unsigned HOST_WIDE_INT | |
538dd0b7 | 389 | alloc_object_size (const gcall *call, int object_size_type) |
10a0d495 | 390 | { |
5039610b | 391 | tree callee, bytes = NULL_TREE; |
51bc54a6 DM |
392 | tree alloc_size; |
393 | int arg1 = -1, arg2 = -1; | |
10a0d495 | 394 | |
726a989a | 395 | gcc_assert (is_gimple_call (call)); |
10a0d495 | 396 | |
726a989a | 397 | callee = gimple_call_fndecl (call); |
51bc54a6 DM |
398 | if (!callee) |
399 | return unknown[object_size_type]; | |
400 | ||
c3284718 RS |
401 | alloc_size = lookup_attribute ("alloc_size", |
402 | TYPE_ATTRIBUTES (TREE_TYPE (callee))); | |
51bc54a6 DM |
403 | if (alloc_size && TREE_VALUE (alloc_size)) |
404 | { | |
405 | tree p = TREE_VALUE (alloc_size); | |
406 | ||
407 | arg1 = TREE_INT_CST_LOW (TREE_VALUE (p))-1; | |
408 | if (TREE_CHAIN (p)) | |
726a989a | 409 | arg2 = TREE_INT_CST_LOW (TREE_VALUE (TREE_CHAIN (p)))-1; |
51bc54a6 | 410 | } |
b8698a0f | 411 | |
51bc54a6 | 412 | if (DECL_BUILT_IN_CLASS (callee) == BUILT_IN_NORMAL) |
10a0d495 JJ |
413 | switch (DECL_FUNCTION_CODE (callee)) |
414 | { | |
51bc54a6 DM |
415 | case BUILT_IN_CALLOC: |
416 | arg2 = 1; | |
417 | /* fall through */ | |
10a0d495 JJ |
418 | case BUILT_IN_MALLOC: |
419 | case BUILT_IN_ALLOCA: | |
13e49da9 | 420 | case BUILT_IN_ALLOCA_WITH_ALIGN: |
51bc54a6 | 421 | arg1 = 0; |
10a0d495 JJ |
422 | default: |
423 | break; | |
424 | } | |
425 | ||
726a989a RB |
426 | if (arg1 < 0 || arg1 >= (int)gimple_call_num_args (call) |
427 | || TREE_CODE (gimple_call_arg (call, arg1)) != INTEGER_CST | |
b8698a0f | 428 | || (arg2 >= 0 |
726a989a RB |
429 | && (arg2 >= (int)gimple_call_num_args (call) |
430 | || TREE_CODE (gimple_call_arg (call, arg2)) != INTEGER_CST))) | |
b8698a0f | 431 | return unknown[object_size_type]; |
51bc54a6 DM |
432 | |
433 | if (arg2 >= 0) | |
434 | bytes = size_binop (MULT_EXPR, | |
726a989a RB |
435 | fold_convert (sizetype, gimple_call_arg (call, arg1)), |
436 | fold_convert (sizetype, gimple_call_arg (call, arg2))); | |
51bc54a6 | 437 | else if (arg1 >= 0) |
726a989a | 438 | bytes = fold_convert (sizetype, gimple_call_arg (call, arg1)); |
51bc54a6 | 439 | |
cc269bb6 | 440 | if (bytes && tree_fits_uhwi_p (bytes)) |
ae7e9ddd | 441 | return tree_to_uhwi (bytes); |
10a0d495 JJ |
442 | |
443 | return unknown[object_size_type]; | |
444 | } | |
445 | ||
446 | ||
447 | /* If object size is propagated from one of function's arguments directly | |
726a989a | 448 | to its return value, return that argument for GIMPLE_CALL statement CALL. |
10a0d495 JJ |
449 | Otherwise return NULL. */ |
450 | ||
451 | static tree | |
538dd0b7 | 452 | pass_through_call (const gcall *call) |
10a0d495 | 453 | { |
726a989a | 454 | tree callee = gimple_call_fndecl (call); |
10a0d495 JJ |
455 | |
456 | if (callee | |
457 | && DECL_BUILT_IN_CLASS (callee) == BUILT_IN_NORMAL) | |
458 | switch (DECL_FUNCTION_CODE (callee)) | |
459 | { | |
460 | case BUILT_IN_MEMCPY: | |
461 | case BUILT_IN_MEMMOVE: | |
462 | case BUILT_IN_MEMSET: | |
463 | case BUILT_IN_STRCPY: | |
464 | case BUILT_IN_STRNCPY: | |
465 | case BUILT_IN_STRCAT: | |
466 | case BUILT_IN_STRNCAT: | |
467 | case BUILT_IN_MEMCPY_CHK: | |
468 | case BUILT_IN_MEMMOVE_CHK: | |
469 | case BUILT_IN_MEMSET_CHK: | |
470 | case BUILT_IN_STRCPY_CHK: | |
471 | case BUILT_IN_STRNCPY_CHK: | |
f3fc9b80 | 472 | case BUILT_IN_STPNCPY_CHK: |
10a0d495 JJ |
473 | case BUILT_IN_STRCAT_CHK: |
474 | case BUILT_IN_STRNCAT_CHK: | |
8b1bdcc5 | 475 | case BUILT_IN_ASSUME_ALIGNED: |
726a989a RB |
476 | if (gimple_call_num_args (call) >= 1) |
477 | return gimple_call_arg (call, 0); | |
10a0d495 JJ |
478 | break; |
479 | default: | |
480 | break; | |
481 | } | |
482 | ||
483 | return NULL_TREE; | |
484 | } | |
485 | ||
486 | ||
487 | /* Compute __builtin_object_size value for PTR. OBJECT_SIZE_TYPE is the | |
488 | second argument from __builtin_object_size. */ | |
489 | ||
490 | unsigned HOST_WIDE_INT | |
491 | compute_builtin_object_size (tree ptr, int object_size_type) | |
492 | { | |
493 | gcc_assert (object_size_type >= 0 && object_size_type <= 3); | |
494 | ||
495 | if (! offset_limit) | |
496 | init_offset_limit (); | |
497 | ||
498 | if (TREE_CODE (ptr) == ADDR_EXPR) | |
eb9ed98a | 499 | return addr_object_size (NULL, ptr, object_size_type); |
10a0d495 | 500 | |
726a989a | 501 | if (TREE_CODE (ptr) == SSA_NAME |
eb9ed98a | 502 | && POINTER_TYPE_P (TREE_TYPE (ptr)) |
db84d11e | 503 | && computed[object_size_type] != NULL) |
10a0d495 JJ |
504 | { |
505 | if (!bitmap_bit_p (computed[object_size_type], SSA_NAME_VERSION (ptr))) | |
506 | { | |
507 | struct object_size_info osi; | |
508 | bitmap_iterator bi; | |
509 | unsigned int i; | |
510 | ||
db84d11e JJ |
511 | if (num_ssa_names > object_sizes[object_size_type].length ()) |
512 | object_sizes[object_size_type].safe_grow (num_ssa_names); | |
10a0d495 JJ |
513 | if (dump_file) |
514 | { | |
515 | fprintf (dump_file, "Computing %s %sobject size for ", | |
516 | (object_size_type & 2) ? "minimum" : "maximum", | |
517 | (object_size_type & 1) ? "sub" : ""); | |
518 | print_generic_expr (dump_file, ptr, dump_flags); | |
519 | fprintf (dump_file, ":\n"); | |
520 | } | |
521 | ||
522 | osi.visited = BITMAP_ALLOC (NULL); | |
523 | osi.reexamine = BITMAP_ALLOC (NULL); | |
524 | osi.object_size_type = object_size_type; | |
525 | osi.depths = NULL; | |
526 | osi.stack = NULL; | |
527 | osi.tos = NULL; | |
528 | ||
529 | /* First pass: walk UD chains, compute object sizes that | |
530 | can be computed. osi.reexamine bitmap at the end will | |
531 | contain what variables were found in dependency cycles | |
532 | and therefore need to be reexamined. */ | |
533 | osi.pass = 0; | |
534 | osi.changed = false; | |
535 | collect_object_sizes_for (&osi, ptr); | |
536 | ||
537 | /* Second pass: keep recomputing object sizes of variables | |
538 | that need reexamination, until no object sizes are | |
539 | increased or all object sizes are computed. */ | |
540 | if (! bitmap_empty_p (osi.reexamine)) | |
541 | { | |
542 | bitmap reexamine = BITMAP_ALLOC (NULL); | |
543 | ||
544 | /* If looking for minimum instead of maximum object size, | |
545 | detect cases where a pointer is increased in a loop. | |
546 | Although even without this detection pass 2 would eventually | |
547 | terminate, it could take a long time. If a pointer is | |
548 | increasing this way, we need to assume 0 object size. | |
549 | E.g. p = &buf[0]; while (cond) p = p + 4; */ | |
550 | if (object_size_type & 2) | |
551 | { | |
5ed6ace5 MD |
552 | osi.depths = XCNEWVEC (unsigned int, num_ssa_names); |
553 | osi.stack = XNEWVEC (unsigned int, num_ssa_names); | |
10a0d495 JJ |
554 | osi.tos = osi.stack; |
555 | osi.pass = 1; | |
556 | /* collect_object_sizes_for is changing | |
557 | osi.reexamine bitmap, so iterate over a copy. */ | |
558 | bitmap_copy (reexamine, osi.reexamine); | |
559 | EXECUTE_IF_SET_IN_BITMAP (reexamine, 0, i, bi) | |
560 | if (bitmap_bit_p (osi.reexamine, i)) | |
561 | check_for_plus_in_loops (&osi, ssa_name (i)); | |
562 | ||
563 | free (osi.depths); | |
564 | osi.depths = NULL; | |
565 | free (osi.stack); | |
566 | osi.stack = NULL; | |
567 | osi.tos = NULL; | |
568 | } | |
569 | ||
570 | do | |
571 | { | |
572 | osi.pass = 2; | |
573 | osi.changed = false; | |
574 | /* collect_object_sizes_for is changing | |
575 | osi.reexamine bitmap, so iterate over a copy. */ | |
576 | bitmap_copy (reexamine, osi.reexamine); | |
577 | EXECUTE_IF_SET_IN_BITMAP (reexamine, 0, i, bi) | |
578 | if (bitmap_bit_p (osi.reexamine, i)) | |
579 | { | |
580 | collect_object_sizes_for (&osi, ssa_name (i)); | |
581 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
582 | { | |
583 | fprintf (dump_file, "Reexamining "); | |
584 | print_generic_expr (dump_file, ssa_name (i), | |
585 | dump_flags); | |
586 | fprintf (dump_file, "\n"); | |
587 | } | |
588 | } | |
589 | } | |
590 | while (osi.changed); | |
591 | ||
592 | BITMAP_FREE (reexamine); | |
593 | } | |
594 | EXECUTE_IF_SET_IN_BITMAP (osi.reexamine, 0, i, bi) | |
595 | bitmap_set_bit (computed[object_size_type], i); | |
596 | ||
597 | /* Debugging dumps. */ | |
598 | if (dump_file) | |
599 | { | |
600 | EXECUTE_IF_SET_IN_BITMAP (osi.visited, 0, i, bi) | |
601 | if (object_sizes[object_size_type][i] | |
602 | != unknown[object_size_type]) | |
603 | { | |
604 | print_generic_expr (dump_file, ssa_name (i), | |
605 | dump_flags); | |
606 | fprintf (dump_file, | |
607 | ": %s %sobject size " | |
608 | HOST_WIDE_INT_PRINT_UNSIGNED "\n", | |
609 | (object_size_type & 2) ? "minimum" : "maximum", | |
610 | (object_size_type & 1) ? "sub" : "", | |
611 | object_sizes[object_size_type][i]); | |
612 | } | |
613 | } | |
614 | ||
615 | BITMAP_FREE (osi.reexamine); | |
616 | BITMAP_FREE (osi.visited); | |
617 | } | |
618 | ||
619 | return object_sizes[object_size_type][SSA_NAME_VERSION (ptr)]; | |
620 | } | |
621 | ||
622 | return unknown[object_size_type]; | |
623 | } | |
624 | ||
726a989a | 625 | /* Compute object_sizes for PTR, defined to VALUE, which is not an SSA_NAME. */ |
10a0d495 JJ |
626 | |
627 | static void | |
628 | expr_object_size (struct object_size_info *osi, tree ptr, tree value) | |
629 | { | |
630 | int object_size_type = osi->object_size_type; | |
631 | unsigned int varno = SSA_NAME_VERSION (ptr); | |
632 | unsigned HOST_WIDE_INT bytes; | |
633 | ||
634 | gcc_assert (object_sizes[object_size_type][varno] | |
635 | != unknown[object_size_type]); | |
636 | gcc_assert (osi->pass == 0); | |
637 | ||
638 | if (TREE_CODE (value) == WITH_SIZE_EXPR) | |
639 | value = TREE_OPERAND (value, 0); | |
640 | ||
641 | /* Pointer variables should have been handled by merge_object_sizes. */ | |
642 | gcc_assert (TREE_CODE (value) != SSA_NAME | |
643 | || !POINTER_TYPE_P (TREE_TYPE (value))); | |
644 | ||
645 | if (TREE_CODE (value) == ADDR_EXPR) | |
eb9ed98a | 646 | bytes = addr_object_size (osi, value, object_size_type); |
10a0d495 JJ |
647 | else |
648 | bytes = unknown[object_size_type]; | |
649 | ||
650 | if ((object_size_type & 2) == 0) | |
651 | { | |
652 | if (object_sizes[object_size_type][varno] < bytes) | |
653 | object_sizes[object_size_type][varno] = bytes; | |
654 | } | |
655 | else | |
656 | { | |
657 | if (object_sizes[object_size_type][varno] > bytes) | |
658 | object_sizes[object_size_type][varno] = bytes; | |
659 | } | |
660 | } | |
661 | ||
662 | ||
726a989a RB |
663 | /* Compute object_sizes for PTR, defined to the result of a call. */ |
664 | ||
665 | static void | |
538dd0b7 | 666 | call_object_size (struct object_size_info *osi, tree ptr, gcall *call) |
726a989a RB |
667 | { |
668 | int object_size_type = osi->object_size_type; | |
669 | unsigned int varno = SSA_NAME_VERSION (ptr); | |
670 | unsigned HOST_WIDE_INT bytes; | |
671 | ||
672 | gcc_assert (is_gimple_call (call)); | |
673 | ||
674 | gcc_assert (object_sizes[object_size_type][varno] | |
675 | != unknown[object_size_type]); | |
676 | gcc_assert (osi->pass == 0); | |
677 | ||
678 | bytes = alloc_object_size (call, object_size_type); | |
679 | ||
680 | if ((object_size_type & 2) == 0) | |
681 | { | |
682 | if (object_sizes[object_size_type][varno] < bytes) | |
683 | object_sizes[object_size_type][varno] = bytes; | |
684 | } | |
685 | else | |
686 | { | |
687 | if (object_sizes[object_size_type][varno] > bytes) | |
688 | object_sizes[object_size_type][varno] = bytes; | |
689 | } | |
690 | } | |
691 | ||
692 | ||
693 | /* Compute object_sizes for PTR, defined to an unknown value. */ | |
694 | ||
695 | static void | |
696 | unknown_object_size (struct object_size_info *osi, tree ptr) | |
697 | { | |
698 | int object_size_type = osi->object_size_type; | |
699 | unsigned int varno = SSA_NAME_VERSION (ptr); | |
700 | unsigned HOST_WIDE_INT bytes; | |
701 | ||
702 | gcc_assert (object_sizes[object_size_type][varno] | |
703 | != unknown[object_size_type]); | |
704 | gcc_assert (osi->pass == 0); | |
705 | ||
706 | bytes = unknown[object_size_type]; | |
707 | ||
708 | if ((object_size_type & 2) == 0) | |
709 | { | |
710 | if (object_sizes[object_size_type][varno] < bytes) | |
711 | object_sizes[object_size_type][varno] = bytes; | |
712 | } | |
713 | else | |
714 | { | |
715 | if (object_sizes[object_size_type][varno] > bytes) | |
716 | object_sizes[object_size_type][varno] = bytes; | |
717 | } | |
718 | } | |
719 | ||
720 | ||
10a0d495 JJ |
721 | /* Merge object sizes of ORIG + OFFSET into DEST. Return true if |
722 | the object size might need reexamination later. */ | |
723 | ||
724 | static bool | |
725 | merge_object_sizes (struct object_size_info *osi, tree dest, tree orig, | |
726 | unsigned HOST_WIDE_INT offset) | |
727 | { | |
728 | int object_size_type = osi->object_size_type; | |
729 | unsigned int varno = SSA_NAME_VERSION (dest); | |
730 | unsigned HOST_WIDE_INT orig_bytes; | |
731 | ||
732 | if (object_sizes[object_size_type][varno] == unknown[object_size_type]) | |
733 | return false; | |
734 | if (offset >= offset_limit) | |
735 | { | |
736 | object_sizes[object_size_type][varno] = unknown[object_size_type]; | |
737 | return false; | |
738 | } | |
739 | ||
740 | if (osi->pass == 0) | |
741 | collect_object_sizes_for (osi, orig); | |
742 | ||
743 | orig_bytes = object_sizes[object_size_type][SSA_NAME_VERSION (orig)]; | |
744 | if (orig_bytes != unknown[object_size_type]) | |
745 | orig_bytes = (offset > orig_bytes) | |
746 | ? (unsigned HOST_WIDE_INT) 0 : orig_bytes - offset; | |
747 | ||
748 | if ((object_size_type & 2) == 0) | |
749 | { | |
750 | if (object_sizes[object_size_type][varno] < orig_bytes) | |
751 | { | |
752 | object_sizes[object_size_type][varno] = orig_bytes; | |
753 | osi->changed = true; | |
754 | } | |
755 | } | |
756 | else | |
757 | { | |
758 | if (object_sizes[object_size_type][varno] > orig_bytes) | |
759 | { | |
760 | object_sizes[object_size_type][varno] = orig_bytes; | |
761 | osi->changed = true; | |
762 | } | |
763 | } | |
764 | return bitmap_bit_p (osi->reexamine, SSA_NAME_VERSION (orig)); | |
765 | } | |
766 | ||
767 | ||
726a989a RB |
768 | /* Compute object_sizes for VAR, defined to the result of an assignment |
769 | with operator POINTER_PLUS_EXPR. Return true if the object size might | |
770 | need reexamination later. */ | |
10a0d495 JJ |
771 | |
772 | static bool | |
726a989a | 773 | plus_stmt_object_size (struct object_size_info *osi, tree var, gimple stmt) |
10a0d495 | 774 | { |
10a0d495 JJ |
775 | int object_size_type = osi->object_size_type; |
776 | unsigned int varno = SSA_NAME_VERSION (var); | |
777 | unsigned HOST_WIDE_INT bytes; | |
726a989a RB |
778 | tree op0, op1; |
779 | ||
70f34814 RG |
780 | if (gimple_assign_rhs_code (stmt) == POINTER_PLUS_EXPR) |
781 | { | |
782 | op0 = gimple_assign_rhs1 (stmt); | |
783 | op1 = gimple_assign_rhs2 (stmt); | |
784 | } | |
785 | else if (gimple_assign_rhs_code (stmt) == ADDR_EXPR) | |
786 | { | |
787 | tree rhs = TREE_OPERAND (gimple_assign_rhs1 (stmt), 0); | |
788 | gcc_assert (TREE_CODE (rhs) == MEM_REF); | |
789 | op0 = TREE_OPERAND (rhs, 0); | |
790 | op1 = TREE_OPERAND (rhs, 1); | |
791 | } | |
792 | else | |
793 | gcc_unreachable (); | |
10a0d495 JJ |
794 | |
795 | if (object_sizes[object_size_type][varno] == unknown[object_size_type]) | |
796 | return false; | |
797 | ||
10a0d495 | 798 | /* Handle PTR + OFFSET here. */ |
5be014d5 | 799 | if (TREE_CODE (op1) == INTEGER_CST |
10a0d495 JJ |
800 | && (TREE_CODE (op0) == SSA_NAME |
801 | || TREE_CODE (op0) == ADDR_EXPR)) | |
802 | { | |
cc269bb6 | 803 | if (! tree_fits_uhwi_p (op1)) |
10a0d495 JJ |
804 | bytes = unknown[object_size_type]; |
805 | else if (TREE_CODE (op0) == SSA_NAME) | |
ae7e9ddd | 806 | return merge_object_sizes (osi, var, op0, tree_to_uhwi (op1)); |
10a0d495 JJ |
807 | else |
808 | { | |
ae7e9ddd | 809 | unsigned HOST_WIDE_INT off = tree_to_uhwi (op1); |
10a0d495 | 810 | |
726a989a | 811 | /* op0 will be ADDR_EXPR here. */ |
eb9ed98a | 812 | bytes = addr_object_size (osi, op0, object_size_type); |
ac5a28a6 JH |
813 | if (bytes == unknown[object_size_type]) |
814 | ; | |
815 | else if (off > offset_limit) | |
10a0d495 JJ |
816 | bytes = unknown[object_size_type]; |
817 | else if (off > bytes) | |
818 | bytes = 0; | |
819 | else | |
820 | bytes -= off; | |
821 | } | |
822 | } | |
823 | else | |
824 | bytes = unknown[object_size_type]; | |
825 | ||
826 | if ((object_size_type & 2) == 0) | |
827 | { | |
828 | if (object_sizes[object_size_type][varno] < bytes) | |
829 | object_sizes[object_size_type][varno] = bytes; | |
830 | } | |
831 | else | |
832 | { | |
833 | if (object_sizes[object_size_type][varno] > bytes) | |
834 | object_sizes[object_size_type][varno] = bytes; | |
835 | } | |
836 | return false; | |
837 | } | |
838 | ||
839 | ||
4e71066d | 840 | /* Compute object_sizes for VAR, defined at STMT, which is |
f255541f RC |
841 | a COND_EXPR. Return true if the object size might need reexamination |
842 | later. */ | |
843 | ||
844 | static bool | |
4e71066d | 845 | cond_expr_object_size (struct object_size_info *osi, tree var, gimple stmt) |
f255541f RC |
846 | { |
847 | tree then_, else_; | |
848 | int object_size_type = osi->object_size_type; | |
849 | unsigned int varno = SSA_NAME_VERSION (var); | |
850 | bool reexamine = false; | |
851 | ||
4e71066d | 852 | gcc_assert (gimple_assign_rhs_code (stmt) == COND_EXPR); |
f255541f RC |
853 | |
854 | if (object_sizes[object_size_type][varno] == unknown[object_size_type]) | |
855 | return false; | |
856 | ||
4e71066d RG |
857 | then_ = gimple_assign_rhs2 (stmt); |
858 | else_ = gimple_assign_rhs3 (stmt); | |
f255541f RC |
859 | |
860 | if (TREE_CODE (then_) == SSA_NAME) | |
861 | reexamine |= merge_object_sizes (osi, var, then_, 0); | |
862 | else | |
863 | expr_object_size (osi, var, then_); | |
864 | ||
865 | if (TREE_CODE (else_) == SSA_NAME) | |
866 | reexamine |= merge_object_sizes (osi, var, else_, 0); | |
867 | else | |
868 | expr_object_size (osi, var, else_); | |
869 | ||
870 | return reexamine; | |
871 | } | |
872 | ||
10a0d495 JJ |
873 | /* Compute object sizes for VAR. |
874 | For ADDR_EXPR an object size is the number of remaining bytes | |
619519c8 | 875 | to the end of the object (where what is considered an object depends on |
10a0d495 | 876 | OSI->object_size_type). |
726a989a | 877 | For allocation GIMPLE_CALL like malloc or calloc object size is the size |
10a0d495 | 878 | of the allocation. |
5be014d5 | 879 | For POINTER_PLUS_EXPR where second operand is a constant integer, |
10a0d495 JJ |
880 | object size is object size of the first operand minus the constant. |
881 | If the constant is bigger than the number of remaining bytes until the | |
882 | end of the object, object size is 0, but if it is instead a pointer | |
883 | subtraction, object size is unknown[object_size_type]. | |
884 | To differentiate addition from subtraction, ADDR_EXPR returns | |
885 | unknown[object_size_type] for all objects bigger than half of the address | |
886 | space, and constants less than half of the address space are considered | |
887 | addition, while bigger constants subtraction. | |
726a989a | 888 | For a memcpy like GIMPLE_CALL that always returns one of its arguments, the |
10a0d495 JJ |
889 | object size is object size of that argument. |
890 | Otherwise, object size is the maximum of object sizes of variables | |
891 | that it might be set to. */ | |
892 | ||
893 | static void | |
894 | collect_object_sizes_for (struct object_size_info *osi, tree var) | |
895 | { | |
896 | int object_size_type = osi->object_size_type; | |
897 | unsigned int varno = SSA_NAME_VERSION (var); | |
726a989a | 898 | gimple stmt; |
10a0d495 JJ |
899 | bool reexamine; |
900 | ||
901 | if (bitmap_bit_p (computed[object_size_type], varno)) | |
902 | return; | |
903 | ||
904 | if (osi->pass == 0) | |
905 | { | |
fcaa4ca4 | 906 | if (bitmap_set_bit (osi->visited, varno)) |
10a0d495 | 907 | { |
10a0d495 JJ |
908 | object_sizes[object_size_type][varno] |
909 | = (object_size_type & 2) ? -1 : 0; | |
910 | } | |
911 | else | |
912 | { | |
913 | /* Found a dependency loop. Mark the variable for later | |
914 | re-examination. */ | |
915 | bitmap_set_bit (osi->reexamine, varno); | |
916 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
917 | { | |
918 | fprintf (dump_file, "Found a dependency loop at "); | |
919 | print_generic_expr (dump_file, var, dump_flags); | |
920 | fprintf (dump_file, "\n"); | |
921 | } | |
922 | return; | |
923 | } | |
924 | } | |
925 | ||
926 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
927 | { | |
928 | fprintf (dump_file, "Visiting use-def links for "); | |
929 | print_generic_expr (dump_file, var, dump_flags); | |
930 | fprintf (dump_file, "\n"); | |
931 | } | |
932 | ||
933 | stmt = SSA_NAME_DEF_STMT (var); | |
934 | reexamine = false; | |
935 | ||
726a989a | 936 | switch (gimple_code (stmt)) |
10a0d495 | 937 | { |
726a989a | 938 | case GIMPLE_ASSIGN: |
10a0d495 | 939 | { |
70f34814 RG |
940 | tree rhs = gimple_assign_rhs1 (stmt); |
941 | if (gimple_assign_rhs_code (stmt) == POINTER_PLUS_EXPR | |
942 | || (gimple_assign_rhs_code (stmt) == ADDR_EXPR | |
943 | && TREE_CODE (TREE_OPERAND (rhs, 0)) == MEM_REF)) | |
726a989a | 944 | reexamine = plus_stmt_object_size (osi, var, stmt); |
4e71066d RG |
945 | else if (gimple_assign_rhs_code (stmt) == COND_EXPR) |
946 | reexamine = cond_expr_object_size (osi, var, stmt); | |
726a989a RB |
947 | else if (gimple_assign_single_p (stmt) |
948 | || gimple_assign_unary_nop_p (stmt)) | |
949 | { | |
726a989a RB |
950 | if (TREE_CODE (rhs) == SSA_NAME |
951 | && POINTER_TYPE_P (TREE_TYPE (rhs))) | |
952 | reexamine = merge_object_sizes (osi, var, rhs, 0); | |
726a989a RB |
953 | else |
954 | expr_object_size (osi, var, rhs); | |
955 | } | |
956 | else | |
957 | unknown_object_size (osi, var); | |
958 | break; | |
959 | } | |
f255541f | 960 | |
726a989a RB |
961 | case GIMPLE_CALL: |
962 | { | |
538dd0b7 DM |
963 | gcall *call_stmt = as_a <gcall *> (stmt); |
964 | tree arg = pass_through_call (call_stmt); | |
726a989a RB |
965 | if (arg) |
966 | { | |
967 | if (TREE_CODE (arg) == SSA_NAME | |
968 | && POINTER_TYPE_P (TREE_TYPE (arg))) | |
969 | reexamine = merge_object_sizes (osi, var, arg, 0); | |
726a989a RB |
970 | else |
971 | expr_object_size (osi, var, arg); | |
972 | } | |
973 | else | |
538dd0b7 | 974 | call_object_size (osi, var, call_stmt); |
10a0d495 JJ |
975 | break; |
976 | } | |
977 | ||
726a989a | 978 | case GIMPLE_ASM: |
10a0d495 JJ |
979 | /* Pointers defined by __asm__ statements can point anywhere. */ |
980 | object_sizes[object_size_type][varno] = unknown[object_size_type]; | |
981 | break; | |
982 | ||
726a989a | 983 | case GIMPLE_NOP: |
70b5e7dc RG |
984 | if (SSA_NAME_VAR (var) |
985 | && TREE_CODE (SSA_NAME_VAR (var)) == PARM_DECL) | |
986 | expr_object_size (osi, var, SSA_NAME_VAR (var)); | |
987 | else | |
988 | /* Uninitialized SSA names point nowhere. */ | |
989 | object_sizes[object_size_type][varno] = unknown[object_size_type]; | |
10a0d495 JJ |
990 | break; |
991 | ||
726a989a | 992 | case GIMPLE_PHI: |
10a0d495 | 993 | { |
726a989a | 994 | unsigned i; |
10a0d495 | 995 | |
726a989a | 996 | for (i = 0; i < gimple_phi_num_args (stmt); i++) |
10a0d495 | 997 | { |
726a989a | 998 | tree rhs = gimple_phi_arg (stmt, i)->def; |
10a0d495 JJ |
999 | |
1000 | if (object_sizes[object_size_type][varno] | |
1001 | == unknown[object_size_type]) | |
1002 | break; | |
1003 | ||
1004 | if (TREE_CODE (rhs) == SSA_NAME) | |
1005 | reexamine |= merge_object_sizes (osi, var, rhs, 0); | |
1006 | else if (osi->pass == 0) | |
1007 | expr_object_size (osi, var, rhs); | |
1008 | } | |
1009 | break; | |
1010 | } | |
726a989a | 1011 | |
10a0d495 JJ |
1012 | default: |
1013 | gcc_unreachable (); | |
1014 | } | |
1015 | ||
1016 | if (! reexamine | |
1017 | || object_sizes[object_size_type][varno] == unknown[object_size_type]) | |
1018 | { | |
1019 | bitmap_set_bit (computed[object_size_type], varno); | |
1020 | bitmap_clear_bit (osi->reexamine, varno); | |
1021 | } | |
1022 | else | |
1023 | { | |
1024 | bitmap_set_bit (osi->reexamine, varno); | |
1025 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1026 | { | |
1027 | fprintf (dump_file, "Need to reexamine "); | |
1028 | print_generic_expr (dump_file, var, dump_flags); | |
1029 | fprintf (dump_file, "\n"); | |
1030 | } | |
1031 | } | |
1032 | } | |
1033 | ||
1034 | ||
1035 | /* Helper function for check_for_plus_in_loops. Called recursively | |
1036 | to detect loops. */ | |
1037 | ||
1038 | static void | |
1039 | check_for_plus_in_loops_1 (struct object_size_info *osi, tree var, | |
1040 | unsigned int depth) | |
1041 | { | |
726a989a | 1042 | gimple stmt = SSA_NAME_DEF_STMT (var); |
10a0d495 JJ |
1043 | unsigned int varno = SSA_NAME_VERSION (var); |
1044 | ||
1045 | if (osi->depths[varno]) | |
1046 | { | |
1047 | if (osi->depths[varno] != depth) | |
1048 | { | |
1049 | unsigned int *sp; | |
1050 | ||
1051 | /* Found a loop involving pointer addition. */ | |
1052 | for (sp = osi->tos; sp > osi->stack; ) | |
1053 | { | |
1054 | --sp; | |
1055 | bitmap_clear_bit (osi->reexamine, *sp); | |
1056 | bitmap_set_bit (computed[osi->object_size_type], *sp); | |
1057 | object_sizes[osi->object_size_type][*sp] = 0; | |
1058 | if (*sp == varno) | |
1059 | break; | |
1060 | } | |
1061 | } | |
1062 | return; | |
1063 | } | |
1064 | else if (! bitmap_bit_p (osi->reexamine, varno)) | |
1065 | return; | |
1066 | ||
1067 | osi->depths[varno] = depth; | |
1068 | *osi->tos++ = varno; | |
1069 | ||
726a989a | 1070 | switch (gimple_code (stmt)) |
10a0d495 | 1071 | { |
10a0d495 | 1072 | |
726a989a | 1073 | case GIMPLE_ASSIGN: |
10a0d495 | 1074 | { |
726a989a RB |
1075 | if ((gimple_assign_single_p (stmt) |
1076 | || gimple_assign_unary_nop_p (stmt)) | |
1077 | && TREE_CODE (gimple_assign_rhs1 (stmt)) == SSA_NAME) | |
1078 | { | |
1079 | tree rhs = gimple_assign_rhs1 (stmt); | |
1080 | ||
1081 | check_for_plus_in_loops_1 (osi, rhs, depth); | |
1082 | } | |
1083 | else if (gimple_assign_rhs_code (stmt) == POINTER_PLUS_EXPR) | |
1084 | { | |
1085 | tree basevar = gimple_assign_rhs1 (stmt); | |
1086 | tree cst = gimple_assign_rhs2 (stmt); | |
1087 | ||
1088 | gcc_assert (TREE_CODE (cst) == INTEGER_CST); | |
1089 | ||
1090 | check_for_plus_in_loops_1 (osi, basevar, | |
1091 | depth + !integer_zerop (cst)); | |
1092 | } | |
1093 | else | |
1094 | gcc_unreachable (); | |
1095 | break; | |
1096 | } | |
10a0d495 | 1097 | |
726a989a RB |
1098 | case GIMPLE_CALL: |
1099 | { | |
538dd0b7 DM |
1100 | gcall *call_stmt = as_a <gcall *> (stmt); |
1101 | tree arg = pass_through_call (call_stmt); | |
726a989a RB |
1102 | if (arg) |
1103 | { | |
1104 | if (TREE_CODE (arg) == SSA_NAME) | |
1105 | check_for_plus_in_loops_1 (osi, arg, depth); | |
1106 | else | |
1107 | gcc_unreachable (); | |
1108 | } | |
1109 | break; | |
10a0d495 | 1110 | } |
726a989a RB |
1111 | |
1112 | case GIMPLE_PHI: | |
10a0d495 | 1113 | { |
726a989a | 1114 | unsigned i; |
10a0d495 | 1115 | |
726a989a | 1116 | for (i = 0; i < gimple_phi_num_args (stmt); i++) |
10a0d495 | 1117 | { |
726a989a | 1118 | tree rhs = gimple_phi_arg (stmt, i)->def; |
10a0d495 JJ |
1119 | |
1120 | if (TREE_CODE (rhs) == SSA_NAME) | |
1121 | check_for_plus_in_loops_1 (osi, rhs, depth); | |
1122 | } | |
1123 | break; | |
1124 | } | |
726a989a | 1125 | |
10a0d495 JJ |
1126 | default: |
1127 | gcc_unreachable (); | |
1128 | } | |
1129 | ||
1130 | osi->depths[varno] = 0; | |
1131 | osi->tos--; | |
1132 | } | |
1133 | ||
1134 | ||
1135 | /* Check if some pointer we are computing object size of is being increased | |
1136 | within a loop. If yes, assume all the SSA variables participating in | |
1137 | that loop have minimum object sizes 0. */ | |
1138 | ||
1139 | static void | |
1140 | check_for_plus_in_loops (struct object_size_info *osi, tree var) | |
1141 | { | |
726a989a | 1142 | gimple stmt = SSA_NAME_DEF_STMT (var); |
10a0d495 | 1143 | |
726a989a RB |
1144 | /* NOTE: In the pre-tuples code, we handled a CALL_EXPR here, |
1145 | and looked for a POINTER_PLUS_EXPR in the pass-through | |
1146 | argument, if any. In GIMPLE, however, such an expression | |
1147 | is not a valid call operand. */ | |
10a0d495 | 1148 | |
726a989a RB |
1149 | if (is_gimple_assign (stmt) |
1150 | && gimple_assign_rhs_code (stmt) == POINTER_PLUS_EXPR) | |
1151 | { | |
1152 | tree basevar = gimple_assign_rhs1 (stmt); | |
1153 | tree cst = gimple_assign_rhs2 (stmt); | |
b8698a0f | 1154 | |
726a989a RB |
1155 | gcc_assert (TREE_CODE (cst) == INTEGER_CST); |
1156 | ||
1157 | if (integer_zerop (cst)) | |
1158 | return; | |
1159 | ||
1160 | osi->depths[SSA_NAME_VERSION (basevar)] = 1; | |
1161 | *osi->tos++ = SSA_NAME_VERSION (basevar); | |
1162 | check_for_plus_in_loops_1 (osi, var, 2); | |
1163 | osi->depths[SSA_NAME_VERSION (basevar)] = 0; | |
1164 | osi->tos--; | |
10a0d495 JJ |
1165 | } |
1166 | } | |
1167 | ||
1168 | ||
1169 | /* Initialize data structures for the object size computation. */ | |
1170 | ||
1171 | void | |
1172 | init_object_sizes (void) | |
1173 | { | |
1174 | int object_size_type; | |
1175 | ||
db84d11e | 1176 | if (computed[0]) |
10a0d495 JJ |
1177 | return; |
1178 | ||
1179 | for (object_size_type = 0; object_size_type <= 3; object_size_type++) | |
1180 | { | |
db84d11e | 1181 | object_sizes[object_size_type].safe_grow (num_ssa_names); |
10a0d495 JJ |
1182 | computed[object_size_type] = BITMAP_ALLOC (NULL); |
1183 | } | |
1184 | ||
1185 | init_offset_limit (); | |
1186 | } | |
1187 | ||
1188 | ||
1189 | /* Destroy data structures after the object size computation. */ | |
1190 | ||
862d0b35 | 1191 | static void |
10a0d495 JJ |
1192 | fini_object_sizes (void) |
1193 | { | |
1194 | int object_size_type; | |
1195 | ||
1196 | for (object_size_type = 0; object_size_type <= 3; object_size_type++) | |
1197 | { | |
db84d11e | 1198 | object_sizes[object_size_type].release (); |
10a0d495 | 1199 | BITMAP_FREE (computed[object_size_type]); |
10a0d495 JJ |
1200 | } |
1201 | } | |
1202 | ||
1203 | ||
1204 | /* Simple pass to optimize all __builtin_object_size () builtins. */ | |
1205 | ||
be55bfe6 TS |
1206 | namespace { |
1207 | ||
1208 | const pass_data pass_data_object_sizes = | |
1209 | { | |
1210 | GIMPLE_PASS, /* type */ | |
1211 | "objsz", /* name */ | |
1212 | OPTGROUP_NONE, /* optinfo_flags */ | |
be55bfe6 TS |
1213 | TV_NONE, /* tv_id */ |
1214 | ( PROP_cfg | PROP_ssa ), /* properties_required */ | |
1215 | 0, /* properties_provided */ | |
1216 | 0, /* properties_destroyed */ | |
1217 | 0, /* todo_flags_start */ | |
3bea341f | 1218 | 0, /* todo_flags_finish */ |
be55bfe6 TS |
1219 | }; |
1220 | ||
1221 | class pass_object_sizes : public gimple_opt_pass | |
1222 | { | |
1223 | public: | |
1224 | pass_object_sizes (gcc::context *ctxt) | |
1225 | : gimple_opt_pass (pass_data_object_sizes, ctxt) | |
1226 | {} | |
1227 | ||
1228 | /* opt_pass methods: */ | |
1229 | opt_pass * clone () { return new pass_object_sizes (m_ctxt); } | |
1230 | virtual unsigned int execute (function *); | |
1231 | ||
1232 | }; // class pass_object_sizes | |
1233 | ||
1234 | unsigned int | |
1235 | pass_object_sizes::execute (function *fun) | |
10a0d495 JJ |
1236 | { |
1237 | basic_block bb; | |
be55bfe6 | 1238 | FOR_EACH_BB_FN (bb, fun) |
10a0d495 | 1239 | { |
726a989a RB |
1240 | gimple_stmt_iterator i; |
1241 | for (i = gsi_start_bb (bb); !gsi_end_p (i); gsi_next (&i)) | |
10a0d495 | 1242 | { |
1eadb567 | 1243 | tree result; |
726a989a | 1244 | gimple call = gsi_stmt (i); |
1eadb567 | 1245 | if (!gimple_call_builtin_p (call, BUILT_IN_OBJECT_SIZE)) |
10a0d495 JJ |
1246 | continue; |
1247 | ||
1248 | init_object_sizes (); | |
672ff0b6 JJ |
1249 | |
1250 | /* In the first pass instance, only attempt to fold | |
1251 | __builtin_object_size (x, 1) and __builtin_object_size (x, 3), | |
1252 | and rather than folding the builtin to the constant if any, | |
1253 | create a MIN_EXPR or MAX_EXPR of the __builtin_object_size | |
1254 | call result and the computed constant. */ | |
1255 | if (first_pass_instance) | |
1256 | { | |
1257 | tree ost = gimple_call_arg (call, 1); | |
1258 | if (tree_fits_uhwi_p (ost)) | |
1259 | { | |
1260 | unsigned HOST_WIDE_INT object_size_type = tree_to_uhwi (ost); | |
1261 | tree ptr = gimple_call_arg (call, 0); | |
1262 | tree lhs = gimple_call_lhs (call); | |
1263 | if ((object_size_type == 1 || object_size_type == 3) | |
1264 | && (TREE_CODE (ptr) == ADDR_EXPR | |
1265 | || TREE_CODE (ptr) == SSA_NAME) | |
1266 | && lhs) | |
1267 | { | |
1268 | tree type = TREE_TYPE (lhs); | |
1269 | unsigned HOST_WIDE_INT bytes | |
1270 | = compute_builtin_object_size (ptr, object_size_type); | |
1271 | if (bytes != (unsigned HOST_WIDE_INT) (object_size_type == 1 | |
1272 | ? -1 : 0) | |
1273 | && wi::fits_to_tree_p (bytes, type)) | |
1274 | { | |
1275 | tree tem = make_ssa_name (type); | |
1276 | gimple_call_set_lhs (call, tem); | |
1277 | enum tree_code code | |
1278 | = object_size_type == 1 ? MIN_EXPR : MAX_EXPR; | |
1279 | tree cst = build_int_cstu (type, bytes); | |
1280 | gimple g = gimple_build_assign (lhs, code, tem, cst); | |
1281 | gsi_insert_after (&i, g, GSI_NEW_STMT); | |
1282 | update_stmt (call); | |
1283 | } | |
1284 | } | |
1285 | } | |
1286 | continue; | |
1287 | } | |
1288 | ||
538dd0b7 | 1289 | result = fold_call_stmt (as_a <gcall *> (call), false); |
10a0d495 JJ |
1290 | if (!result) |
1291 | { | |
672ff0b6 JJ |
1292 | tree ost = gimple_call_arg (call, 1); |
1293 | ||
1294 | if (tree_fits_uhwi_p (ost)) | |
10a0d495 | 1295 | { |
672ff0b6 | 1296 | unsigned HOST_WIDE_INT object_size_type = tree_to_uhwi (ost); |
10a0d495 | 1297 | |
672ff0b6 JJ |
1298 | if (object_size_type < 2) |
1299 | result = fold_convert (size_type_node, | |
1300 | integer_minus_one_node); | |
1301 | else if (object_size_type < 4) | |
1302 | result = build_zero_cst (size_type_node); | |
10a0d495 JJ |
1303 | } |
1304 | ||
1305 | if (!result) | |
1306 | continue; | |
1307 | } | |
1308 | ||
1eadb567 RB |
1309 | gcc_assert (TREE_CODE (result) == INTEGER_CST); |
1310 | ||
10a0d495 JJ |
1311 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1312 | { | |
1313 | fprintf (dump_file, "Simplified\n "); | |
726a989a | 1314 | print_gimple_stmt (dump_file, call, 0, dump_flags); |
1eadb567 RB |
1315 | fprintf (dump_file, " to "); |
1316 | print_generic_expr (dump_file, result, 0); | |
1317 | fprintf (dump_file, "\n"); | |
10a0d495 JJ |
1318 | } |
1319 | ||
1eadb567 RB |
1320 | tree lhs = gimple_call_lhs (call); |
1321 | if (!lhs) | |
1322 | continue; | |
726a989a | 1323 | |
1eadb567 RB |
1324 | /* Propagate into all uses and fold those stmts. */ |
1325 | gimple use_stmt; | |
1326 | imm_use_iterator iter; | |
1327 | FOR_EACH_IMM_USE_STMT (use_stmt, iter, lhs) | |
10a0d495 | 1328 | { |
1eadb567 RB |
1329 | use_operand_p use_p; |
1330 | FOR_EACH_IMM_USE_ON_STMT (use_p, iter) | |
1331 | SET_USE (use_p, result); | |
1332 | gimple_stmt_iterator gsi = gsi_for_stmt (use_stmt); | |
1333 | fold_stmt (&gsi); | |
1334 | update_stmt (gsi_stmt (gsi)); | |
10a0d495 JJ |
1335 | } |
1336 | } | |
1337 | } | |
1338 | ||
1339 | fini_object_sizes (); | |
c2924966 | 1340 | return 0; |
10a0d495 JJ |
1341 | } |
1342 | ||
27a4cd48 DM |
1343 | } // anon namespace |
1344 | ||
1345 | gimple_opt_pass * | |
1346 | make_pass_object_sizes (gcc::context *ctxt) | |
1347 | { | |
1348 | return new pass_object_sizes (ctxt); | |
1349 | } |