On Thu, Nov 28, 2013 at 07:04:43PM -0500, Jason Merrill wrote:
> On 11/28/2013 12:14 PM, Marek Polacek wrote:
> > t = fold_build2 (COMPOUND_EXPR, TREE_TYPE (t),
> >- ubsan_instrument_vla (input_location, t), t);
> >+ ubsan_instrument_vla (input_location, t),
> >+ /* Cast to void to prevent bogus warning. */
> >+ build1 (CONVERT_EXPR, void_type_node, t));
> > finish_expr_stmt (t);
>
> Why do you need the COMPOUND_EXPR at all? Why can't you just do
>
> t = ubsan_instrument_vla (input_location, t);
>
> ?
You're right, I don't need it at all here. It was needed in the C FE
and I lived under wrong impression that I'll need it in the C++ as
well. And of course the warning goes away... Thanks a lot.
Tested x86_64-unknown-linux-gnu. Ok now?
2013-11-29 Marek Polacek <pola...@redhat.com>
PR sanitizer/59331
cp/
* decl.c (compute_array_index_type): Don't build COMPOUND_EXPR for
instrumentation.
testsuite/
* g++.dg/ubsan/pr59331.C: New test.
* g++.dg/ubsan/cxx1y-vla.C: Enable -Wall -Wno-unused-variable.
Disable the -w option.
* c-c++-common/ubsan/vla-1.c: Likewise.
* c-c++-common/ubsan/vla-2.c: Likewise.
* c-c++-common/ubsan/vla-3.c: Don't use the -w option.
--- gcc/cp/decl.c.mp5 2013-11-28 16:15:42.606690956 +0100
+++ gcc/cp/decl.c 2013-11-29 12:31:17.032996706 +0100
@@ -8434,8 +8434,7 @@ compute_array_index_type (tree name, tre
LE_EXPR rather than LT_EXPR. */
tree t = fold_build2 (PLUS_EXPR, TREE_TYPE (itype), itype,
build_one_cst (TREE_TYPE (itype)));
- t = fold_build2 (COMPOUND_EXPR, TREE_TYPE (t),
- ubsan_instrument_vla (input_location, t), t);
+ t = ubsan_instrument_vla (input_location, t);
finish_expr_stmt (t);
}
}
--- gcc/testsuite/g++.dg/ubsan/pr59331.C.mp5 2013-11-28 16:29:13.967882392
+0100
+++ gcc/testsuite/g++.dg/ubsan/pr59331.C 2013-11-28 17:54:24.125451857
+0100
@@ -0,0 +1,8 @@
+/* { dg-do compile } */
+/* { dg-options "-fsanitize=vla-bound -Wall -Wno-unused-variable" } */
+
+void foo(int i)
+{
+ /* Don't warn here with "value computed is not used". */
+ char a[i];
+}
--- gcc/testsuite/g++.dg/ubsan/cxx1y-vla.C.mp5 2013-11-28 17:51:51.066755487
+0100
+++ gcc/testsuite/g++.dg/ubsan/cxx1y-vla.C 2013-11-28 18:28:33.411162834
+0100
@@ -1,5 +1,5 @@
/* { dg-do run } */
-/* { dg-options "-fsanitize=vla-bound -w -std=c++1y" } */
+/* { dg-options "-fsanitize=vla-bound -Wall -Wno-unused-variable -std=c++1y" }
*/
/* { dg-shouldfail "ubsan" } */
int
--- gcc/testsuite/c-c++-common/ubsan/vla-1.c.mp5 2013-11-28
18:03:32.318664603 +0100
+++ gcc/testsuite/c-c++-common/ubsan/vla-1.c 2013-11-28 18:28:33.410162830
+0100
@@ -1,5 +1,5 @@
/* { dg-do run } */
-/* { dg-options "-fsanitize=vla-bound -w" } */
+/* { dg-options "-fsanitize=vla-bound -Wall -Wno-unused-variable" } */
static int
bar (void)
--- gcc/testsuite/c-c++-common/ubsan/vla-3.c.mp5 2013-11-28
18:04:25.737865780 +0100
+++ gcc/testsuite/c-c++-common/ubsan/vla-3.c 2013-11-28 18:28:33.411162834
+0100
@@ -1,5 +1,5 @@
/* { dg-do run } */
-/* { dg-options "-fsanitize=vla-bound -w" } */
+/* { dg-options "-fsanitize=vla-bound" } */
/* Don't instrument the arrays here. */
int
--- gcc/testsuite/c-c++-common/ubsan/vla-2.c.mp5 2013-11-28
18:03:54.249748290 +0100
+++ gcc/testsuite/c-c++-common/ubsan/vla-2.c 2013-11-28 18:28:33.410162830
+0100
@@ -1,5 +1,5 @@
/* { dg-do run } */
-/* { dg-options "-fsanitize=vla-bound -w" } */
+/* { dg-options "-fsanitize=vla-bound -Wall -Wno-unused-variable" } */
int
main (void)
Marek
