Hi!
gsi_safe_insert_before properly updates gsi_bb in gimple_stmt_iterator
in case it splits objects, but unfortunately build_check_stmt was in
some places (but not others) using a copy of the iterator rather than
the iterator passed from callers and so didn't propagate that to callers.
I guess it didn't matter much before when it was just using
gsi_insert_before as that really didn't change the iterator.
The !before_p case is apparently dead code, nothing is calling it with
before_p=false since around 4.9.
Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
2024-10-24 Jakub Jelinek <ja...@redhat.com>
PR sanitizer/117209
* asan.cc (maybe_cast_to_ptrmode): Formatting fix.
(build_check_stmt): Don't copy *iter into gsi, perform all
the updates on iter directly.
* gcc.dg/asan/pr117209.c: New test.
--- gcc/asan.cc.jj 2024-08-30 09:09:44.924630892 +0200
+++ gcc/asan.cc 2024-10-23 12:00:39.352238282 +0200
@@ -2610,7 +2610,7 @@ maybe_cast_to_ptrmode (location_t loc, t
if (ptrofftype_p (len))
return len;
gimple *g = gimple_build_assign (make_ssa_name (pointer_sized_int_node),
- NOP_EXPR, len);
+ NOP_EXPR, len);
gimple_set_location (g, loc);
if (before_p)
gsi_safe_insert_before (iter, g);
@@ -2644,16 +2644,13 @@ build_check_stmt (location_t loc, tree b
bool is_non_zero_len, bool before_p, bool is_store,
bool is_scalar_access, unsigned int align = 0)
{
- gimple_stmt_iterator gsi = *iter;
gimple *g;
gcc_assert (!(size_in_bytes > 0 && !is_non_zero_len));
gcc_assert (size_in_bytes == -1 || size_in_bytes >= 1);
- gsi = *iter;
-
base = unshare_expr (base);
- base = maybe_create_ssa_name (loc, base, &gsi, before_p);
+ base = maybe_create_ssa_name (loc, base, iter, before_p);
if (len)
{
@@ -2704,12 +2701,11 @@ build_check_stmt (location_t loc, tree b
align / BITS_PER_UNIT));
gimple_set_location (g, loc);
if (before_p)
- gsi_safe_insert_before (&gsi, g);
+ gsi_safe_insert_before (iter, g);
else
{
- gsi_insert_after (&gsi, g, GSI_NEW_STMT);
- gsi_next (&gsi);
- *iter = gsi;
+ gsi_insert_after (iter, g, GSI_NEW_STMT);
+ gsi_next (iter);
}
}
--- gcc/testsuite/gcc.dg/asan/pr117209.c.jj 2024-10-23 12:16:19.418928237
+0200
+++ gcc/testsuite/gcc.dg/asan/pr117209.c 2024-10-23 12:16:12.970019545
+0200
@@ -0,0 +1,15 @@
+/* PR sanitizer/117209 */
+/* { dg-do compile } */
+/* { dg-options "-fsanitize=address" } */
+
+struct A { char a; };
+void foo (void);
+__attribute__((returns_twice, const)) int bar (struct A);
+
+void
+baz (struct A *x, int *y, int z)
+{
+ if (z)
+ foo ();
+ *y = bar (*x);
+}
Jakub
