> Am 24.10.2024 um 09:29 schrieb Jakub Jelinek <ja...@redhat.com>:
>
> 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?
Ok
Richard
> 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
>
