1 /* Optimize and expand sanitizer functions.
2 Copyright (C) 2014-2020 Free Software Foundation, Inc.
3 Contributed by Marek Polacek <polacek@redhat.com>
4
5 This file is part of GCC.
6
7 GCC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 3, or (at your option) any later
10 version.
11
12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
15 for more details.
16
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING3. If not see
19 <http://www.gnu.org/licenses/>. */
20
21 #include "config.h"
22 #include "system.h"
23 #include "coretypes.h"
24 #include "backend.h"
25 #include "tree.h"
26 #include "gimple.h"
27 #include "ssa.h"
28 #include "tree-pass.h"
29 #include "tree-ssa-operands.h"
30 #include "gimple-pretty-print.h"
31 #include "fold-const.h"
32 #include "gimple-iterator.h"
33 #include "stringpool.h"
34 #include "attribs.h"
35 #include "asan.h"
36 #include "ubsan.h"
37 #include "tree-hash-traits.h"
38 #include "gimple-ssa.h"
39 #include "tree-phinodes.h"
40 #include "ssa-iterators.h"
41 #include "gimplify.h"
42 #include "gimple-iterator.h"
43 #include "gimple-walk.h"
44 #include "cfghooks.h"
45 #include "tree-dfa.h"
46 #include "tree-ssa.h"
47 #include "varasm.h"
48
49 /* This is used to carry information about basic blocks. It is
50 attached to the AUX field of the standard CFG block. */
51
52 struct sanopt_info
53 {
54 /* True if this BB might call (directly or indirectly) free/munmap
55 or similar operation. */
56 bool has_freeing_call_p;
57
58 /* True if HAS_FREEING_CALL_P flag has been computed. */
59 bool has_freeing_call_computed_p;
60
61 /* True if there is a block with HAS_FREEING_CALL_P flag set
62 on any path between an immediate dominator of BB, denoted
63 imm(BB), and BB. */
64 bool imm_dom_path_with_freeing_call_p;
65
66 /* True if IMM_DOM_PATH_WITH_FREEING_CALL_P has been computed. */
67 bool imm_dom_path_with_freeing_call_computed_p;
68
69 /* Number of possibly freeing calls encountered in this bb
70 (so far). */
71 uint64_t freeing_call_events;
72
73 /* True if BB is currently being visited during computation
74 of IMM_DOM_PATH_WITH_FREEING_CALL_P flag. */
75 bool being_visited_p;
76
77 /* True if this BB has been visited in the dominator walk. */
78 bool visited_p;
79 };
80
81 /* If T has a single definition of form T = T2, return T2. */
82
83 static tree
maybe_get_single_definition(tree t)84 maybe_get_single_definition (tree t)
85 {
86 if (TREE_CODE (t) == SSA_NAME)
87 {
88 gimple *g = SSA_NAME_DEF_STMT (t);
89 if (gimple_assign_single_p (g))
90 return gimple_assign_rhs1 (g);
91 }
92 return NULL_TREE;
93 }
94
95 /* Tree triplet for vptr_check_map. */
96 struct sanopt_tree_triplet
97 {
98 tree t1, t2, t3;
99 };
100
101 /* Traits class for tree triplet hash maps below. */
102
103 struct sanopt_tree_triplet_hash : typed_noop_remove <sanopt_tree_triplet>
104 {
105 typedef sanopt_tree_triplet value_type;
106 typedef sanopt_tree_triplet compare_type;
107
108 static hashval_t
hashsanopt_tree_triplet_hash109 hash (const sanopt_tree_triplet &ref)
110 {
111 inchash::hash hstate (0);
112 inchash::add_expr (ref.t1, hstate);
113 inchash::add_expr (ref.t2, hstate);
114 inchash::add_expr (ref.t3, hstate);
115 return hstate.end ();
116 }
117
118 static bool
equalsanopt_tree_triplet_hash119 equal (const sanopt_tree_triplet &ref1, const sanopt_tree_triplet &ref2)
120 {
121 return operand_equal_p (ref1.t1, ref2.t1, 0)
122 && operand_equal_p (ref1.t2, ref2.t2, 0)
123 && operand_equal_p (ref1.t3, ref2.t3, 0);
124 }
125
126 static void
mark_deletedsanopt_tree_triplet_hash127 mark_deleted (sanopt_tree_triplet &ref)
128 {
129 ref.t1 = reinterpret_cast<tree> (1);
130 }
131
132 static const bool empty_zero_p = true;
133
134 static void
mark_emptysanopt_tree_triplet_hash135 mark_empty (sanopt_tree_triplet &ref)
136 {
137 ref.t1 = NULL;
138 }
139
140 static bool
is_deletedsanopt_tree_triplet_hash141 is_deleted (const sanopt_tree_triplet &ref)
142 {
143 return ref.t1 == reinterpret_cast<tree> (1);
144 }
145
146 static bool
is_emptysanopt_tree_triplet_hash147 is_empty (const sanopt_tree_triplet &ref)
148 {
149 return ref.t1 == NULL;
150 }
151 };
152
153 /* Tree couple for ptr_check_map. */
154 struct sanopt_tree_couple
155 {
156 tree ptr;
157 bool pos_p;
158 };
159
160 /* Traits class for tree triplet hash maps below. */
161
162 struct sanopt_tree_couple_hash : typed_noop_remove <sanopt_tree_couple>
163 {
164 typedef sanopt_tree_couple value_type;
165 typedef sanopt_tree_couple compare_type;
166
167 static hashval_t
hashsanopt_tree_couple_hash168 hash (const sanopt_tree_couple &ref)
169 {
170 inchash::hash hstate (0);
171 inchash::add_expr (ref.ptr, hstate);
172 hstate.add_int (ref.pos_p);
173 return hstate.end ();
174 }
175
176 static bool
equalsanopt_tree_couple_hash177 equal (const sanopt_tree_couple &ref1, const sanopt_tree_couple &ref2)
178 {
179 return operand_equal_p (ref1.ptr, ref2.ptr, 0)
180 && ref1.pos_p == ref2.pos_p;
181 }
182
183 static void
mark_deletedsanopt_tree_couple_hash184 mark_deleted (sanopt_tree_couple &ref)
185 {
186 ref.ptr = reinterpret_cast<tree> (1);
187 }
188
189 static const bool empty_zero_p = true;
190
191 static void
mark_emptysanopt_tree_couple_hash192 mark_empty (sanopt_tree_couple &ref)
193 {
194 ref.ptr = NULL;
195 }
196
197 static bool
is_deletedsanopt_tree_couple_hash198 is_deleted (const sanopt_tree_couple &ref)
199 {
200 return ref.ptr == reinterpret_cast<tree> (1);
201 }
202
203 static bool
is_emptysanopt_tree_couple_hash204 is_empty (const sanopt_tree_couple &ref)
205 {
206 return ref.ptr == NULL;
207 }
208 };
209
210 /* This is used to carry various hash maps and variables used
211 in sanopt_optimize_walker. */
212
213 class sanopt_ctx
214 {
215 public:
216 /* This map maps a pointer (the first argument of UBSAN_NULL) to
217 a vector of UBSAN_NULL call statements that check this pointer. */
218 hash_map<tree, auto_vec<gimple *> > null_check_map;
219
220 /* This map maps a pointer (the second argument of ASAN_CHECK) to
221 a vector of ASAN_CHECK call statements that check the access. */
222 hash_map<tree_operand_hash, auto_vec<gimple *> > asan_check_map;
223
224 /* This map maps a tree triplet (the first, second and fourth argument
225 of UBSAN_VPTR) to a vector of UBSAN_VPTR call statements that check
226 that virtual table pointer. */
227 hash_map<sanopt_tree_triplet_hash, auto_vec<gimple *> > vptr_check_map;
228
229 /* This map maps a couple (tree and boolean) to a vector of UBSAN_PTR
230 call statements that check that pointer overflow. */
231 hash_map<sanopt_tree_couple_hash, auto_vec<gimple *> > ptr_check_map;
232
233 /* Number of IFN_ASAN_CHECK statements. */
234 int asan_num_accesses;
235
236 /* True when the current functions constains an ASAN_MARK. */
237 bool contains_asan_mark;
238 };
239
240 /* Return true if there might be any call to free/munmap operation
241 on any path in between DOM (which should be imm(BB)) and BB. */
242
243 static bool
imm_dom_path_with_freeing_call(basic_block bb,basic_block dom)244 imm_dom_path_with_freeing_call (basic_block bb, basic_block dom)
245 {
246 sanopt_info *info = (sanopt_info *) bb->aux;
247 edge e;
248 edge_iterator ei;
249
250 if (info->imm_dom_path_with_freeing_call_computed_p)
251 return info->imm_dom_path_with_freeing_call_p;
252
253 info->being_visited_p = true;
254
255 FOR_EACH_EDGE (e, ei, bb->preds)
256 {
257 sanopt_info *pred_info = (sanopt_info *) e->src->aux;
258
259 if (e->src == dom)
260 continue;
261
262 if ((pred_info->imm_dom_path_with_freeing_call_computed_p
263 && pred_info->imm_dom_path_with_freeing_call_p)
264 || (pred_info->has_freeing_call_computed_p
265 && pred_info->has_freeing_call_p))
266 {
267 info->imm_dom_path_with_freeing_call_computed_p = true;
268 info->imm_dom_path_with_freeing_call_p = true;
269 info->being_visited_p = false;
270 return true;
271 }
272 }
273
274 FOR_EACH_EDGE (e, ei, bb->preds)
275 {
276 sanopt_info *pred_info = (sanopt_info *) e->src->aux;
277
278 if (e->src == dom)
279 continue;
280
281 if (pred_info->has_freeing_call_computed_p)
282 continue;
283
284 gimple_stmt_iterator gsi;
285 for (gsi = gsi_start_bb (e->src); !gsi_end_p (gsi); gsi_next (&gsi))
286 {
287 gimple *stmt = gsi_stmt (gsi);
288 gasm *asm_stmt;
289
290 if ((is_gimple_call (stmt) && !nonfreeing_call_p (stmt))
291 || ((asm_stmt = dyn_cast <gasm *> (stmt))
292 && (gimple_asm_clobbers_memory_p (asm_stmt)
293 || gimple_asm_volatile_p (asm_stmt))))
294 {
295 pred_info->has_freeing_call_p = true;
296 break;
297 }
298 }
299
300 pred_info->has_freeing_call_computed_p = true;
301 if (pred_info->has_freeing_call_p)
302 {
303 info->imm_dom_path_with_freeing_call_computed_p = true;
304 info->imm_dom_path_with_freeing_call_p = true;
305 info->being_visited_p = false;
306 return true;
307 }
308 }
309
310 FOR_EACH_EDGE (e, ei, bb->preds)
311 {
312 if (e->src == dom)
313 continue;
314
315 basic_block src;
316 for (src = e->src; src != dom; )
317 {
318 sanopt_info *pred_info = (sanopt_info *) src->aux;
319 if (pred_info->being_visited_p)
320 break;
321 basic_block imm = get_immediate_dominator (CDI_DOMINATORS, src);
322 if (imm_dom_path_with_freeing_call (src, imm))
323 {
324 info->imm_dom_path_with_freeing_call_computed_p = true;
325 info->imm_dom_path_with_freeing_call_p = true;
326 info->being_visited_p = false;
327 return true;
328 }
329 src = imm;
330 }
331 }
332
333 info->imm_dom_path_with_freeing_call_computed_p = true;
334 info->imm_dom_path_with_freeing_call_p = false;
335 info->being_visited_p = false;
336 return false;
337 }
338
339 /* Get the first dominating check from the list of stored checks.
340 Non-dominating checks are silently dropped. */
341
342 static gimple *
maybe_get_dominating_check(auto_vec<gimple * > & v)343 maybe_get_dominating_check (auto_vec<gimple *> &v)
344 {
345 for (; !v.is_empty (); v.pop ())
346 {
347 gimple *g = v.last ();
348 sanopt_info *si = (sanopt_info *) gimple_bb (g)->aux;
349 if (!si->visited_p)
350 /* At this point we shouldn't have any statements
351 that aren't dominating the current BB. */
352 return g;
353 }
354 return NULL;
355 }
356
357 /* Optimize away redundant UBSAN_NULL calls. */
358
359 static bool
maybe_optimize_ubsan_null_ifn(class sanopt_ctx * ctx,gimple * stmt)360 maybe_optimize_ubsan_null_ifn (class sanopt_ctx *ctx, gimple *stmt)
361 {
362 gcc_assert (gimple_call_num_args (stmt) == 3);
363 tree ptr = gimple_call_arg (stmt, 0);
364 tree cur_align = gimple_call_arg (stmt, 2);
365 gcc_assert (TREE_CODE (cur_align) == INTEGER_CST);
366 bool remove = false;
367
368 auto_vec<gimple *> &v = ctx->null_check_map.get_or_insert (ptr);
369 gimple *g = maybe_get_dominating_check (v);
370 if (!g)
371 {
372 /* For this PTR we don't have any UBSAN_NULL stmts recorded, so there's
373 nothing to optimize yet. */
374 v.safe_push (stmt);
375 return false;
376 }
377
378 /* We already have recorded a UBSAN_NULL check for this pointer. Perhaps we
379 can drop this one. But only if this check doesn't specify stricter
380 alignment. */
381
382 tree align = gimple_call_arg (g, 2);
383 int kind = tree_to_shwi (gimple_call_arg (g, 1));
384 /* If this is a NULL pointer check where we had segv anyway, we can
385 remove it. */
386 if (integer_zerop (align)
387 && (kind == UBSAN_LOAD_OF
388 || kind == UBSAN_STORE_OF
389 || kind == UBSAN_MEMBER_ACCESS))
390 remove = true;
391 /* Otherwise remove the check in non-recovering mode, or if the
392 stmts have same location. */
393 else if (integer_zerop (align))
394 remove = (flag_sanitize_recover & SANITIZE_NULL) == 0
395 || flag_sanitize_undefined_trap_on_error
396 || gimple_location (g) == gimple_location (stmt);
397 else if (tree_int_cst_le (cur_align, align))
398 remove = (flag_sanitize_recover & SANITIZE_ALIGNMENT) == 0
399 || flag_sanitize_undefined_trap_on_error
400 || gimple_location (g) == gimple_location (stmt);
401
402 if (!remove && gimple_bb (g) == gimple_bb (stmt)
403 && tree_int_cst_compare (cur_align, align) == 0)
404 v.pop ();
405
406 if (!remove)
407 v.safe_push (stmt);
408 return remove;
409 }
410
411 /* Return true when pointer PTR for a given CUR_OFFSET is already sanitized
412 in a given sanitization context CTX. */
413
414 static bool
has_dominating_ubsan_ptr_check(sanopt_ctx * ctx,tree ptr,offset_int & cur_offset)415 has_dominating_ubsan_ptr_check (sanopt_ctx *ctx, tree ptr,
416 offset_int &cur_offset)
417 {
418 bool pos_p = !wi::neg_p (cur_offset);
419 sanopt_tree_couple couple;
420 couple.ptr = ptr;
421 couple.pos_p = pos_p;
422
423 auto_vec<gimple *> &v = ctx->ptr_check_map.get_or_insert (couple);
424 gimple *g = maybe_get_dominating_check (v);
425 if (!g)
426 return false;
427
428 /* We already have recorded a UBSAN_PTR check for this pointer. Perhaps we
429 can drop this one. But only if this check doesn't specify larger offset.
430 */
431 tree offset = gimple_call_arg (g, 1);
432 gcc_assert (TREE_CODE (offset) == INTEGER_CST);
433 offset_int ooffset = wi::sext (wi::to_offset (offset), POINTER_SIZE);
434
435 if (pos_p)
436 {
437 if (wi::les_p (cur_offset, ooffset))
438 return true;
439 }
440 else if (!pos_p && wi::les_p (ooffset, cur_offset))
441 return true;
442
443 return false;
444 }
445
446 /* Record UBSAN_PTR check of given context CTX. Register pointer PTR on
447 a given OFFSET that it's handled by GIMPLE STMT. */
448
449 static void
record_ubsan_ptr_check_stmt(sanopt_ctx * ctx,gimple * stmt,tree ptr,const offset_int & offset)450 record_ubsan_ptr_check_stmt (sanopt_ctx *ctx, gimple *stmt, tree ptr,
451 const offset_int &offset)
452 {
453 sanopt_tree_couple couple;
454 couple.ptr = ptr;
455 couple.pos_p = !wi::neg_p (offset);
456
457 auto_vec<gimple *> &v = ctx->ptr_check_map.get_or_insert (couple);
458 v.safe_push (stmt);
459 }
460
461 /* Optimize away redundant UBSAN_PTR calls. */
462
463 static bool
maybe_optimize_ubsan_ptr_ifn(sanopt_ctx * ctx,gimple * stmt)464 maybe_optimize_ubsan_ptr_ifn (sanopt_ctx *ctx, gimple *stmt)
465 {
466 poly_int64 bitsize, pbitpos;
467 machine_mode mode;
468 int volatilep = 0, reversep, unsignedp = 0;
469 tree offset;
470
471 gcc_assert (gimple_call_num_args (stmt) == 2);
472 tree ptr = gimple_call_arg (stmt, 0);
473 tree off = gimple_call_arg (stmt, 1);
474
475 if (TREE_CODE (off) != INTEGER_CST)
476 return false;
477
478 if (integer_zerop (off))
479 return true;
480
481 offset_int cur_offset = wi::sext (wi::to_offset (off), POINTER_SIZE);
482 if (has_dominating_ubsan_ptr_check (ctx, ptr, cur_offset))
483 return true;
484
485 tree base = ptr;
486 if (TREE_CODE (base) == ADDR_EXPR)
487 {
488 base = TREE_OPERAND (base, 0);
489
490 HOST_WIDE_INT bitpos;
491 base = get_inner_reference (base, &bitsize, &pbitpos, &offset, &mode,
492 &unsignedp, &reversep, &volatilep);
493 if ((offset == NULL_TREE || TREE_CODE (offset) == INTEGER_CST)
494 && DECL_P (base)
495 && ((!VAR_P (base)
496 && TREE_CODE (base) != PARM_DECL
497 && TREE_CODE (base) != RESULT_DECL)
498 || !DECL_REGISTER (base))
499 && pbitpos.is_constant (&bitpos))
500 {
501 offset_int expr_offset;
502 if (offset)
503 expr_offset = wi::to_offset (offset) + bitpos / BITS_PER_UNIT;
504 else
505 expr_offset = bitpos / BITS_PER_UNIT;
506 expr_offset = wi::sext (expr_offset, POINTER_SIZE);
507 offset_int total_offset = expr_offset + cur_offset;
508 if (total_offset != wi::sext (total_offset, POINTER_SIZE))
509 {
510 record_ubsan_ptr_check_stmt (ctx, stmt, ptr, cur_offset);
511 return false;
512 }
513
514 /* If BASE is a fixed size automatic variable or
515 global variable defined in the current TU, we don't have
516 to instrument anything if offset is within address
517 of the variable. */
518 if ((VAR_P (base)
519 || TREE_CODE (base) == PARM_DECL
520 || TREE_CODE (base) == RESULT_DECL)
521 && DECL_SIZE_UNIT (base)
522 && TREE_CODE (DECL_SIZE_UNIT (base)) == INTEGER_CST
523 && (!is_global_var (base) || decl_binds_to_current_def_p (base)))
524 {
525 offset_int base_size = wi::to_offset (DECL_SIZE_UNIT (base));
526 if (!wi::neg_p (expr_offset)
527 && wi::les_p (total_offset, base_size))
528 {
529 if (!wi::neg_p (total_offset)
530 && wi::les_p (total_offset, base_size))
531 return true;
532 }
533 }
534
535 /* Following expression: UBSAN_PTR (&MEM_REF[ptr + x], y) can be
536 handled as follows:
537
538 1) sign (x) == sign (y), then check for dominating check of (x + y)
539 2) sign (x) != sign (y), then first check if we have a dominating
540 check for ptr + x. If so, then we have 2 situations:
541 a) sign (x) == sign (x + y), here we are done, example:
542 UBSAN_PTR (&MEM_REF[ptr + 100], -50)
543 b) check for dominating check of ptr + x + y.
544 */
545
546 bool sign_cur_offset = !wi::neg_p (cur_offset);
547 bool sign_expr_offset = !wi::neg_p (expr_offset);
548
549 tree base_addr
550 = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (base)), base);
551
552 bool add = false;
553 if (sign_cur_offset == sign_expr_offset)
554 {
555 if (has_dominating_ubsan_ptr_check (ctx, base_addr, total_offset))
556 return true;
557 else
558 add = true;
559 }
560 else
561 {
562 if (!has_dominating_ubsan_ptr_check (ctx, base_addr, expr_offset))
563 ; /* Don't record base_addr + expr_offset, it's not a guarding
564 check. */
565 else
566 {
567 bool sign_total_offset = !wi::neg_p (total_offset);
568 if (sign_expr_offset == sign_total_offset)
569 return true;
570 else
571 {
572 if (has_dominating_ubsan_ptr_check (ctx, base_addr,
573 total_offset))
574 return true;
575 else
576 add = true;
577 }
578 }
579 }
580
581 /* Record a new dominating check for base_addr + total_offset. */
582 if (add && !operand_equal_p (base, base_addr, 0))
583 record_ubsan_ptr_check_stmt (ctx, stmt, base_addr,
584 total_offset);
585 }
586 }
587
588 /* For this PTR we don't have any UBSAN_PTR stmts recorded, so there's
589 nothing to optimize yet. */
590 record_ubsan_ptr_check_stmt (ctx, stmt, ptr, cur_offset);
591
592 return false;
593 }
594
595 /* Optimize away redundant UBSAN_VPTR calls. The second argument
596 is the value loaded from the virtual table, so rely on FRE to find out
597 when we can actually optimize. */
598
599 static bool
maybe_optimize_ubsan_vptr_ifn(class sanopt_ctx * ctx,gimple * stmt)600 maybe_optimize_ubsan_vptr_ifn (class sanopt_ctx *ctx, gimple *stmt)
601 {
602 gcc_assert (gimple_call_num_args (stmt) == 5);
603 sanopt_tree_triplet triplet;
604 triplet.t1 = gimple_call_arg (stmt, 0);
605 triplet.t2 = gimple_call_arg (stmt, 1);
606 triplet.t3 = gimple_call_arg (stmt, 3);
607
608 auto_vec<gimple *> &v = ctx->vptr_check_map.get_or_insert (triplet);
609 gimple *g = maybe_get_dominating_check (v);
610 if (!g)
611 {
612 /* For this PTR we don't have any UBSAN_VPTR stmts recorded, so there's
613 nothing to optimize yet. */
614 v.safe_push (stmt);
615 return false;
616 }
617
618 return true;
619 }
620
621 /* Returns TRUE if ASan check of length LEN in block BB can be removed
622 if preceded by checks in V. */
623
624 static bool
can_remove_asan_check(auto_vec<gimple * > & v,tree len,basic_block bb)625 can_remove_asan_check (auto_vec<gimple *> &v, tree len, basic_block bb)
626 {
627 unsigned int i;
628 gimple *g;
629 gimple *to_pop = NULL;
630 bool remove = false;
631 basic_block last_bb = bb;
632 bool cleanup = false;
633
634 FOR_EACH_VEC_ELT_REVERSE (v, i, g)
635 {
636 basic_block gbb = gimple_bb (g);
637 sanopt_info *si = (sanopt_info *) gbb->aux;
638 if (gimple_uid (g) < si->freeing_call_events)
639 {
640 /* If there is a potentially freeing call after g in gbb, we should
641 remove it from the vector, can't use in optimization. */
642 cleanup = true;
643 continue;
644 }
645
646 tree glen = gimple_call_arg (g, 2);
647 gcc_assert (TREE_CODE (glen) == INTEGER_CST);
648
649 /* If we've checked only smaller length than we want to check now,
650 we can't remove the current stmt. If g is in the same basic block,
651 we want to remove it though, as the current stmt is better. */
652 if (tree_int_cst_lt (glen, len))
653 {
654 if (gbb == bb)
655 {
656 to_pop = g;
657 cleanup = true;
658 }
659 continue;
660 }
661
662 while (last_bb != gbb)
663 {
664 /* Paths from last_bb to bb have been checked before.
665 gbb is necessarily a dominator of last_bb, but not necessarily
666 immediate dominator. */
667 if (((sanopt_info *) last_bb->aux)->freeing_call_events)
668 break;
669
670 basic_block imm = get_immediate_dominator (CDI_DOMINATORS, last_bb);
671 gcc_assert (imm);
672 if (imm_dom_path_with_freeing_call (last_bb, imm))
673 break;
674
675 last_bb = imm;
676 }
677 if (last_bb == gbb)
678 remove = true;
679 break;
680 }
681
682 if (cleanup)
683 {
684 unsigned int j = 0, l = v.length ();
685 for (i = 0; i < l; i++)
686 if (v[i] != to_pop
687 && (gimple_uid (v[i])
688 == ((sanopt_info *)
689 gimple_bb (v[i])->aux)->freeing_call_events))
690 {
691 if (i != j)
692 v[j] = v[i];
693 j++;
694 }
695 v.truncate (j);
696 }
697
698 return remove;
699 }
700
701 /* Optimize away redundant ASAN_CHECK calls. */
702
703 static bool
maybe_optimize_asan_check_ifn(class sanopt_ctx * ctx,gimple * stmt)704 maybe_optimize_asan_check_ifn (class sanopt_ctx *ctx, gimple *stmt)
705 {
706 gcc_assert (gimple_call_num_args (stmt) == 4);
707 tree ptr = gimple_call_arg (stmt, 1);
708 tree len = gimple_call_arg (stmt, 2);
709 basic_block bb = gimple_bb (stmt);
710 sanopt_info *info = (sanopt_info *) bb->aux;
711
712 if (TREE_CODE (len) != INTEGER_CST)
713 return false;
714 if (integer_zerop (len))
715 return false;
716
717 gimple_set_uid (stmt, info->freeing_call_events);
718
719 auto_vec<gimple *> *ptr_checks = &ctx->asan_check_map.get_or_insert (ptr);
720
721 tree base_addr = maybe_get_single_definition (ptr);
722 auto_vec<gimple *> *base_checks = NULL;
723 if (base_addr)
724 {
725 base_checks = &ctx->asan_check_map.get_or_insert (base_addr);
726 /* Original pointer might have been invalidated. */
727 ptr_checks = ctx->asan_check_map.get (ptr);
728 }
729
730 gimple *g = maybe_get_dominating_check (*ptr_checks);
731 gimple *g2 = NULL;
732
733 if (base_checks)
734 /* Try with base address as well. */
735 g2 = maybe_get_dominating_check (*base_checks);
736
737 if (g == NULL && g2 == NULL)
738 {
739 /* For this PTR we don't have any ASAN_CHECK stmts recorded, so there's
740 nothing to optimize yet. */
741 ptr_checks->safe_push (stmt);
742 if (base_checks)
743 base_checks->safe_push (stmt);
744 return false;
745 }
746
747 bool remove = false;
748
749 if (ptr_checks)
750 remove = can_remove_asan_check (*ptr_checks, len, bb);
751
752 if (!remove && base_checks)
753 /* Try with base address as well. */
754 remove = can_remove_asan_check (*base_checks, len, bb);
755
756 if (!remove)
757 {
758 ptr_checks->safe_push (stmt);
759 if (base_checks)
760 base_checks->safe_push (stmt);
761 }
762
763 return remove;
764 }
765
766 /* Try to optimize away redundant UBSAN_NULL and ASAN_CHECK calls.
767
768 We walk blocks in the CFG via a depth first search of the dominator
769 tree; we push unique UBSAN_NULL or ASAN_CHECK statements into a vector
770 in the NULL_CHECK_MAP or ASAN_CHECK_MAP hash maps as we enter the
771 blocks. When leaving a block, we mark the block as visited; then
772 when checking the statements in the vector, we ignore statements that
773 are coming from already visited blocks, because these cannot dominate
774 anything anymore. CTX is a sanopt context. */
775
776 static void
sanopt_optimize_walker(basic_block bb,class sanopt_ctx * ctx)777 sanopt_optimize_walker (basic_block bb, class sanopt_ctx *ctx)
778 {
779 basic_block son;
780 gimple_stmt_iterator gsi;
781 sanopt_info *info = (sanopt_info *) bb->aux;
782 bool asan_check_optimize = (flag_sanitize & SANITIZE_ADDRESS) != 0;
783
784 for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi);)
785 {
786 gimple *stmt = gsi_stmt (gsi);
787 bool remove = false;
788
789 if (!is_gimple_call (stmt))
790 {
791 /* Handle asm volatile or asm with "memory" clobber
792 the same as potentionally freeing call. */
793 gasm *asm_stmt = dyn_cast <gasm *> (stmt);
794 if (asm_stmt
795 && asan_check_optimize
796 && (gimple_asm_clobbers_memory_p (asm_stmt)
797 || gimple_asm_volatile_p (asm_stmt)))
798 info->freeing_call_events++;
799 gsi_next (&gsi);
800 continue;
801 }
802
803 if (asan_check_optimize && !nonfreeing_call_p (stmt))
804 info->freeing_call_events++;
805
806 /* If __asan_before_dynamic_init ("module"); is followed by
807 __asan_after_dynamic_init (); without intervening memory loads/stores,
808 there is nothing to guard, so optimize both away. */
809 if (asan_check_optimize
810 && gimple_call_builtin_p (stmt, BUILT_IN_ASAN_BEFORE_DYNAMIC_INIT))
811 {
812 use_operand_p use;
813 gimple *use_stmt;
814 if (single_imm_use (gimple_vdef (stmt), &use, &use_stmt))
815 {
816 if (is_gimple_call (use_stmt)
817 && gimple_call_builtin_p (use_stmt,
818 BUILT_IN_ASAN_AFTER_DYNAMIC_INIT))
819 {
820 unlink_stmt_vdef (use_stmt);
821 gimple_stmt_iterator gsi2 = gsi_for_stmt (use_stmt);
822 gsi_remove (&gsi2, true);
823 remove = true;
824 }
825 }
826 }
827
828 if (gimple_call_internal_p (stmt))
829 switch (gimple_call_internal_fn (stmt))
830 {
831 case IFN_UBSAN_NULL:
832 remove = maybe_optimize_ubsan_null_ifn (ctx, stmt);
833 break;
834 case IFN_UBSAN_VPTR:
835 remove = maybe_optimize_ubsan_vptr_ifn (ctx, stmt);
836 break;
837 case IFN_UBSAN_PTR:
838 remove = maybe_optimize_ubsan_ptr_ifn (ctx, stmt);
839 break;
840 case IFN_ASAN_CHECK:
841 if (asan_check_optimize)
842 remove = maybe_optimize_asan_check_ifn (ctx, stmt);
843 if (!remove)
844 ctx->asan_num_accesses++;
845 break;
846 case IFN_ASAN_MARK:
847 ctx->contains_asan_mark = true;
848 break;
849 default:
850 break;
851 }
852
853 if (remove)
854 {
855 /* Drop this check. */
856 if (dump_file && (dump_flags & TDF_DETAILS))
857 {
858 fprintf (dump_file, "Optimizing out: ");
859 print_gimple_stmt (dump_file, stmt, 0, dump_flags);
860 }
861 unlink_stmt_vdef (stmt);
862 gsi_remove (&gsi, true);
863 }
864 else
865 {
866 if (dump_file && (dump_flags & TDF_DETAILS))
867 {
868 fprintf (dump_file, "Leaving: ");
869 print_gimple_stmt (dump_file, stmt, 0, dump_flags);
870 }
871
872 gsi_next (&gsi);
873 }
874 }
875
876 if (asan_check_optimize)
877 {
878 info->has_freeing_call_p = info->freeing_call_events != 0;
879 info->has_freeing_call_computed_p = true;
880 }
881
882 for (son = first_dom_son (CDI_DOMINATORS, bb);
883 son;
884 son = next_dom_son (CDI_DOMINATORS, son))
885 sanopt_optimize_walker (son, ctx);
886
887 /* We're leaving this BB, so mark it to that effect. */
888 info->visited_p = true;
889 }
890
891 /* Try to remove redundant sanitizer checks in function FUN. */
892
893 static int
sanopt_optimize(function * fun,bool * contains_asan_mark)894 sanopt_optimize (function *fun, bool *contains_asan_mark)
895 {
896 class sanopt_ctx ctx;
897 ctx.asan_num_accesses = 0;
898 ctx.contains_asan_mark = false;
899
900 /* Set up block info for each basic block. */
901 alloc_aux_for_blocks (sizeof (sanopt_info));
902
903 /* We're going to do a dominator walk, so ensure that we have
904 dominance information. */
905 calculate_dominance_info (CDI_DOMINATORS);
906
907 /* Recursively walk the dominator tree optimizing away
908 redundant checks. */
909 sanopt_optimize_walker (ENTRY_BLOCK_PTR_FOR_FN (fun), &ctx);
910
911 free_aux_for_blocks ();
912
913 *contains_asan_mark = ctx.contains_asan_mark;
914 return ctx.asan_num_accesses;
915 }
916
917 /* Perform optimization of sanitize functions. */
918
919 namespace {
920
921 const pass_data pass_data_sanopt =
922 {
923 GIMPLE_PASS, /* type */
924 "sanopt", /* name */
925 OPTGROUP_NONE, /* optinfo_flags */
926 TV_NONE, /* tv_id */
927 ( PROP_ssa | PROP_cfg | PROP_gimple_leh ), /* properties_required */
928 0, /* properties_provided */
929 0, /* properties_destroyed */
930 0, /* todo_flags_start */
931 TODO_update_ssa, /* todo_flags_finish */
932 };
933
934 class pass_sanopt : public gimple_opt_pass
935 {
936 public:
pass_sanopt(gcc::context * ctxt)937 pass_sanopt (gcc::context *ctxt)
938 : gimple_opt_pass (pass_data_sanopt, ctxt)
939 {}
940
941 /* opt_pass methods: */
gate(function *)942 virtual bool gate (function *) { return flag_sanitize; }
943 virtual unsigned int execute (function *);
944
945 }; // class pass_sanopt
946
947 /* Sanitize all ASAN_MARK unpoison calls that are not reachable by a BB
948 that contains an ASAN_MARK poison. All these ASAN_MARK unpoison call
949 can be removed as all variables are unpoisoned in a function prologue. */
950
951 static void
sanitize_asan_mark_unpoison(void)952 sanitize_asan_mark_unpoison (void)
953 {
954 /* 1) Find all BBs that contain an ASAN_MARK poison call. */
955 auto_sbitmap with_poison (last_basic_block_for_fn (cfun) + 1);
956 bitmap_clear (with_poison);
957 basic_block bb;
958
959 FOR_EACH_BB_FN (bb, cfun)
960 {
961 if (bitmap_bit_p (with_poison, bb->index))
962 continue;
963
964 gimple_stmt_iterator gsi;
965 for (gsi = gsi_last_bb (bb); !gsi_end_p (gsi); gsi_prev (&gsi))
966 {
967 gimple *stmt = gsi_stmt (gsi);
968 if (asan_mark_p (stmt, ASAN_MARK_POISON))
969 {
970 bitmap_set_bit (with_poison, bb->index);
971 break;
972 }
973 }
974 }
975
976 auto_sbitmap poisoned (last_basic_block_for_fn (cfun) + 1);
977 bitmap_clear (poisoned);
978 auto_sbitmap worklist (last_basic_block_for_fn (cfun) + 1);
979 bitmap_copy (worklist, with_poison);
980
981 /* 2) Propagate the information to all reachable blocks. */
982 while (!bitmap_empty_p (worklist))
983 {
984 unsigned i = bitmap_first_set_bit (worklist);
985 bitmap_clear_bit (worklist, i);
986 basic_block bb = BASIC_BLOCK_FOR_FN (cfun, i);
987 gcc_assert (bb);
988
989 edge e;
990 edge_iterator ei;
991 FOR_EACH_EDGE (e, ei, bb->succs)
992 if (!bitmap_bit_p (poisoned, e->dest->index))
993 {
994 bitmap_set_bit (poisoned, e->dest->index);
995 bitmap_set_bit (worklist, e->dest->index);
996 }
997 }
998
999 /* 3) Iterate all BBs not included in POISONED BBs and remove unpoison
1000 ASAN_MARK preceding an ASAN_MARK poison (which can still happen). */
1001 FOR_EACH_BB_FN (bb, cfun)
1002 {
1003 if (bitmap_bit_p (poisoned, bb->index))
1004 continue;
1005
1006 gimple_stmt_iterator gsi;
1007 for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi);)
1008 {
1009 gimple *stmt = gsi_stmt (gsi);
1010 if (gimple_call_internal_p (stmt, IFN_ASAN_MARK))
1011 {
1012 if (asan_mark_p (stmt, ASAN_MARK_POISON))
1013 break;
1014 else
1015 {
1016 if (dump_file)
1017 fprintf (dump_file, "Removing ASAN_MARK unpoison\n");
1018 unlink_stmt_vdef (stmt);
1019 release_defs (stmt);
1020 gsi_remove (&gsi, true);
1021 continue;
1022 }
1023 }
1024
1025 gsi_next (&gsi);
1026 }
1027 }
1028 }
1029
1030 /* Return true when STMT is either ASAN_CHECK call or a call of a function
1031 that can contain an ASAN_CHECK. */
1032
1033 static bool
maybe_contains_asan_check(gimple * stmt)1034 maybe_contains_asan_check (gimple *stmt)
1035 {
1036 if (is_gimple_call (stmt))
1037 {
1038 if (gimple_call_internal_p (stmt, IFN_ASAN_MARK))
1039 return false;
1040 else
1041 return !(gimple_call_flags (stmt) & ECF_CONST);
1042 }
1043 else if (is_a<gasm *> (stmt))
1044 return true;
1045
1046 return false;
1047 }
1048
1049 /* Sanitize all ASAN_MARK poison calls that are not followed by an ASAN_CHECK
1050 call. These calls can be removed. */
1051
1052 static void
sanitize_asan_mark_poison(void)1053 sanitize_asan_mark_poison (void)
1054 {
1055 /* 1) Find all BBs that possibly contain an ASAN_CHECK. */
1056 auto_sbitmap with_check (last_basic_block_for_fn (cfun) + 1);
1057 bitmap_clear (with_check);
1058 basic_block bb;
1059
1060 FOR_EACH_BB_FN (bb, cfun)
1061 {
1062 gimple_stmt_iterator gsi;
1063 for (gsi = gsi_last_bb (bb); !gsi_end_p (gsi); gsi_prev (&gsi))
1064 {
1065 gimple *stmt = gsi_stmt (gsi);
1066 if (maybe_contains_asan_check (stmt))
1067 {
1068 bitmap_set_bit (with_check, bb->index);
1069 break;
1070 }
1071 }
1072 }
1073
1074 auto_sbitmap can_reach_check (last_basic_block_for_fn (cfun) + 1);
1075 bitmap_clear (can_reach_check);
1076 auto_sbitmap worklist (last_basic_block_for_fn (cfun) + 1);
1077 bitmap_copy (worklist, with_check);
1078
1079 /* 2) Propagate the information to all definitions blocks. */
1080 while (!bitmap_empty_p (worklist))
1081 {
1082 unsigned i = bitmap_first_set_bit (worklist);
1083 bitmap_clear_bit (worklist, i);
1084 basic_block bb = BASIC_BLOCK_FOR_FN (cfun, i);
1085 gcc_assert (bb);
1086
1087 edge e;
1088 edge_iterator ei;
1089 FOR_EACH_EDGE (e, ei, bb->preds)
1090 if (!bitmap_bit_p (can_reach_check, e->src->index))
1091 {
1092 bitmap_set_bit (can_reach_check, e->src->index);
1093 bitmap_set_bit (worklist, e->src->index);
1094 }
1095 }
1096
1097 /* 3) Iterate all BBs not included in CAN_REACH_CHECK BBs and remove poison
1098 ASAN_MARK not followed by a call to function having an ASAN_CHECK. */
1099 FOR_EACH_BB_FN (bb, cfun)
1100 {
1101 if (bitmap_bit_p (can_reach_check, bb->index))
1102 continue;
1103
1104 gimple_stmt_iterator gsi;
1105 for (gsi = gsi_last_bb (bb); !gsi_end_p (gsi);)
1106 {
1107 gimple *stmt = gsi_stmt (gsi);
1108 if (maybe_contains_asan_check (stmt))
1109 break;
1110 else if (asan_mark_p (stmt, ASAN_MARK_POISON))
1111 {
1112 if (dump_file)
1113 fprintf (dump_file, "Removing ASAN_MARK poison\n");
1114 unlink_stmt_vdef (stmt);
1115 release_defs (stmt);
1116 gimple_stmt_iterator gsi2 = gsi;
1117 gsi_prev (&gsi);
1118 gsi_remove (&gsi2, true);
1119 continue;
1120 }
1121
1122 gsi_prev (&gsi);
1123 }
1124 }
1125 }
1126
1127 /* Rewrite all usages of tree OP which is a PARM_DECL with a VAR_DECL
1128 that is it's DECL_VALUE_EXPR. */
1129
1130 static tree
rewrite_usage_of_param(tree * op,int * walk_subtrees,void *)1131 rewrite_usage_of_param (tree *op, int *walk_subtrees, void *)
1132 {
1133 if (TREE_CODE (*op) == PARM_DECL && DECL_HAS_VALUE_EXPR_P (*op))
1134 {
1135 *op = DECL_VALUE_EXPR (*op);
1136 *walk_subtrees = 0;
1137 }
1138
1139 return NULL;
1140 }
1141
1142 /* For a given function FUN, rewrite all addressable parameters so that
1143 a new automatic variable is introduced. Right after function entry
1144 a parameter is assigned to the variable. */
1145
1146 static void
sanitize_rewrite_addressable_params(function * fun)1147 sanitize_rewrite_addressable_params (function *fun)
1148 {
1149 gimple *g;
1150 gimple_seq stmts = NULL;
1151 bool has_any_addressable_param = false;
1152 auto_vec<tree> clear_value_expr_list;
1153
1154 for (tree arg = DECL_ARGUMENTS (current_function_decl);
1155 arg; arg = DECL_CHAIN (arg))
1156 {
1157 tree type = TREE_TYPE (arg);
1158 if (TREE_ADDRESSABLE (arg)
1159 && !TREE_ADDRESSABLE (type)
1160 && !TREE_THIS_VOLATILE (arg)
1161 && TREE_CODE (TYPE_SIZE (type)) == INTEGER_CST)
1162 {
1163 TREE_ADDRESSABLE (arg) = 0;
1164 /* The parameter is no longer addressable. */
1165 has_any_addressable_param = true;
1166
1167 /* Create a new automatic variable. */
1168 tree var = build_decl (DECL_SOURCE_LOCATION (arg),
1169 VAR_DECL, DECL_NAME (arg), type);
1170 TREE_ADDRESSABLE (var) = 1;
1171 DECL_IGNORED_P (var) = 1;
1172
1173 gimple_add_tmp_var (var);
1174
1175 /* We skip parameters that have a DECL_VALUE_EXPR. */
1176 if (DECL_HAS_VALUE_EXPR_P (arg))
1177 continue;
1178
1179 if (dump_file)
1180 {
1181 fprintf (dump_file,
1182 "Rewriting parameter whose address is taken: ");
1183 print_generic_expr (dump_file, arg, dump_flags);
1184 fputc ('\n', dump_file);
1185 }
1186
1187 SET_DECL_PT_UID (var, DECL_PT_UID (arg));
1188
1189 /* Assign value of parameter to newly created variable. */
1190 if ((TREE_CODE (type) == COMPLEX_TYPE
1191 || TREE_CODE (type) == VECTOR_TYPE))
1192 {
1193 /* We need to create a SSA name that will be used for the
1194 assignment. */
1195 DECL_GIMPLE_REG_P (arg) = 1;
1196 tree tmp = get_or_create_ssa_default_def (cfun, arg);
1197 g = gimple_build_assign (var, tmp);
1198 gimple_set_location (g, DECL_SOURCE_LOCATION (arg));
1199 gimple_seq_add_stmt (&stmts, g);
1200 }
1201 else
1202 {
1203 g = gimple_build_assign (var, arg);
1204 gimple_set_location (g, DECL_SOURCE_LOCATION (arg));
1205 gimple_seq_add_stmt (&stmts, g);
1206 }
1207
1208 if (target_for_debug_bind (arg))
1209 {
1210 g = gimple_build_debug_bind (arg, var, NULL);
1211 gimple_seq_add_stmt (&stmts, g);
1212 clear_value_expr_list.safe_push (arg);
1213 }
1214
1215 DECL_HAS_VALUE_EXPR_P (arg) = 1;
1216 SET_DECL_VALUE_EXPR (arg, var);
1217 }
1218 }
1219
1220 if (!has_any_addressable_param)
1221 return;
1222
1223 /* Replace all usages of PARM_DECLs with the newly
1224 created variable VAR. */
1225 basic_block bb;
1226 FOR_EACH_BB_FN (bb, fun)
1227 {
1228 gimple_stmt_iterator gsi;
1229 for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
1230 {
1231 gimple *stmt = gsi_stmt (gsi);
1232 gimple_stmt_iterator it = gsi_for_stmt (stmt);
1233 walk_gimple_stmt (&it, NULL, rewrite_usage_of_param, NULL);
1234 }
1235 for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi))
1236 {
1237 gphi *phi = dyn_cast<gphi *> (gsi_stmt (gsi));
1238 for (unsigned i = 0; i < gimple_phi_num_args (phi); ++i)
1239 {
1240 hash_set<tree> visited_nodes;
1241 walk_tree (gimple_phi_arg_def_ptr (phi, i),
1242 rewrite_usage_of_param, NULL, &visited_nodes);
1243 }
1244 }
1245 }
1246
1247 /* Unset value expr for parameters for which we created debug bind
1248 expressions. */
1249 unsigned i;
1250 tree arg;
1251 FOR_EACH_VEC_ELT (clear_value_expr_list, i, arg)
1252 {
1253 DECL_HAS_VALUE_EXPR_P (arg) = 0;
1254 SET_DECL_VALUE_EXPR (arg, NULL_TREE);
1255 }
1256
1257 /* Insert default assignments at the beginning of a function. */
1258 basic_block entry_bb = ENTRY_BLOCK_PTR_FOR_FN (fun);
1259 entry_bb = split_edge (single_succ_edge (entry_bb));
1260
1261 gimple_stmt_iterator gsi = gsi_start_bb (entry_bb);
1262 gsi_insert_seq_before (&gsi, stmts, GSI_NEW_STMT);
1263 }
1264
1265 unsigned int
execute(function * fun)1266 pass_sanopt::execute (function *fun)
1267 {
1268 basic_block bb;
1269 int asan_num_accesses = 0;
1270 bool contains_asan_mark = false;
1271 int ret = 0;
1272
1273 /* Try to remove redundant checks. */
1274 if (optimize
1275 && (flag_sanitize
1276 & (SANITIZE_NULL | SANITIZE_ALIGNMENT
1277 | SANITIZE_ADDRESS | SANITIZE_VPTR | SANITIZE_POINTER_OVERFLOW)))
1278 asan_num_accesses = sanopt_optimize (fun, &contains_asan_mark);
1279 else if (flag_sanitize & SANITIZE_ADDRESS)
1280 {
1281 gimple_stmt_iterator gsi;
1282 FOR_EACH_BB_FN (bb, fun)
1283 for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
1284 {
1285 gimple *stmt = gsi_stmt (gsi);
1286 if (gimple_call_internal_p (stmt, IFN_ASAN_CHECK))
1287 ++asan_num_accesses;
1288 else if (gimple_call_internal_p (stmt, IFN_ASAN_MARK))
1289 contains_asan_mark = true;
1290 }
1291 }
1292
1293 if (contains_asan_mark)
1294 {
1295 sanitize_asan_mark_unpoison ();
1296 sanitize_asan_mark_poison ();
1297 }
1298
1299 if (asan_sanitize_stack_p ())
1300 sanitize_rewrite_addressable_params (fun);
1301
1302 bool use_calls = param_asan_instrumentation_with_call_threshold < INT_MAX
1303 && asan_num_accesses >= param_asan_instrumentation_with_call_threshold;
1304
1305 hash_map<tree, tree> shadow_vars_mapping;
1306 bool need_commit_edge_insert = false;
1307 FOR_EACH_BB_FN (bb, fun)
1308 {
1309 gimple_stmt_iterator gsi;
1310 for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); )
1311 {
1312 gimple *stmt = gsi_stmt (gsi);
1313 bool no_next = false;
1314
1315 if (!is_gimple_call (stmt))
1316 {
1317 gsi_next (&gsi);
1318 continue;
1319 }
1320
1321 if (gimple_call_internal_p (stmt))
1322 {
1323 enum internal_fn ifn = gimple_call_internal_fn (stmt);
1324 int this_ret = TODO_cleanup_cfg;
1325 switch (ifn)
1326 {
1327 case IFN_UBSAN_NULL:
1328 no_next = ubsan_expand_null_ifn (&gsi);
1329 break;
1330 case IFN_UBSAN_BOUNDS:
1331 no_next = ubsan_expand_bounds_ifn (&gsi);
1332 break;
1333 case IFN_UBSAN_OBJECT_SIZE:
1334 no_next = ubsan_expand_objsize_ifn (&gsi);
1335 break;
1336 case IFN_UBSAN_PTR:
1337 no_next = ubsan_expand_ptr_ifn (&gsi);
1338 break;
1339 case IFN_UBSAN_VPTR:
1340 no_next = ubsan_expand_vptr_ifn (&gsi);
1341 break;
1342 case IFN_ASAN_CHECK:
1343 no_next = asan_expand_check_ifn (&gsi, use_calls);
1344 break;
1345 case IFN_ASAN_MARK:
1346 no_next = asan_expand_mark_ifn (&gsi);
1347 break;
1348 case IFN_ASAN_POISON:
1349 no_next = asan_expand_poison_ifn (&gsi,
1350 &need_commit_edge_insert,
1351 shadow_vars_mapping);
1352 break;
1353 default:
1354 this_ret = 0;
1355 break;
1356 }
1357 ret |= this_ret;
1358 }
1359 else if (gimple_call_builtin_p (stmt, BUILT_IN_NORMAL))
1360 {
1361 tree callee = gimple_call_fndecl (stmt);
1362 switch (DECL_FUNCTION_CODE (callee))
1363 {
1364 case BUILT_IN_UNREACHABLE:
1365 if (sanitize_flags_p (SANITIZE_UNREACHABLE))
1366 no_next = ubsan_instrument_unreachable (&gsi);
1367 break;
1368 default:
1369 break;
1370 }
1371 }
1372
1373 if (dump_file && (dump_flags & TDF_DETAILS))
1374 {
1375 fprintf (dump_file, "Expanded: ");
1376 print_gimple_stmt (dump_file, stmt, 0, dump_flags);
1377 }
1378
1379 if (!no_next)
1380 gsi_next (&gsi);
1381 }
1382 }
1383
1384 if (need_commit_edge_insert)
1385 gsi_commit_edge_inserts ();
1386
1387 return ret;
1388 }
1389
1390 } // anon namespace
1391
1392 gimple_opt_pass *
make_pass_sanopt(gcc::context * ctxt)1393 make_pass_sanopt (gcc::context *ctxt)
1394 {
1395 return new pass_sanopt (ctxt);
1396 }
1397