On Fri, 13 Apr 2012, Martin Jambor wrote:
> Hi,
>
> currently we ICE when attempting to devirtualize a call to a virtual
> method introduced in a descendant but with a base which is an ancestor
> which does not have it. This is because fold_ctor_reference returns
> constant zero when it cannot find the particular value in the provided
> constructor which is something gimple_get_virt_method_for_binfo cannot
> cope with. The patch below avoids it by simply testing for that
> value and bailing out.
>
> Bootstrapped and tested on x86_64-linux, OK for trunk?
Ok.
Thanks,
Richard.
> Thanks,
>
> Martin
>
>
> 2012-04-12 Martin Jambor <mjam...@suse.cz>
>
> PR middle-end/52939
> * gimple-fold.c (gimple_get_virt_method_for_binfo): Bail out if
> fold_ctor_reference returns a zero constant.
>
> * testsuite/g++.dg/ipa/pr52939.C: New test.
>
> Index: src/gcc/gimple-fold.c
> ===================================================================
> --- src.orig/gcc/gimple-fold.c
> +++ src/gcc/gimple-fold.c
> @@ -3087,7 +3087,7 @@ gimple_get_virt_method_for_binfo (HOST_W
> offset += token * size;
> fn = fold_ctor_reference (TREE_TYPE (TREE_TYPE (v)), DECL_INITIAL (v),
> offset, size);
> - if (!fn)
> + if (!fn || integer_zerop (fn))
> return NULL_TREE;
> gcc_assert (TREE_CODE (fn) == ADDR_EXPR
> || TREE_CODE (fn) == FDESC_EXPR);
> Index: src/gcc/testsuite/g++.dg/ipa/pr52939.C
> ===================================================================
> --- /dev/null
> +++ src/gcc/testsuite/g++.dg/ipa/pr52939.C
> @@ -0,0 +1,58 @@
> +/* Verify that we do not ICE on invalid devirtualizations (which might
> + be OK at run-time because never executed). */
> +/* { dg-do run } */
> +/* { dg-options "-O3 -fno-early-inlining -fno-inline" } */
> +
> +extern "C" void abort (void);
> +
> +class A
> +{
> +public:
> + int data;
> + virtual int foo (int i);
> +};
> +
> +class B : public A
> +{
> +public:
> + virtual int foo (int i);
> + virtual int bar (int i);
> +};
> +
> +int A::foo (int i)
> +{
> + return i + 1;
> +}
> +
> +int B::foo (int i)
> +{
> + return i + 2;
> +}
> +
> +int B::bar (int i)
> +{
> + return i + 3;
> +}
> +
> +static int middleman (class A *obj, int i)
> +{
> + class B *b = (class B *) obj;
> +
> + if (i != 1)
> + return b->bar (i);
> + else
> + return i;
> +}
> +
> +int __attribute__ ((noinline,noclone)) get_input(void)
> +{
> + return 1;
> +}
> +
> +int main (int argc, char *argv[])
> +{
> + class A o;
> + if (middleman (&o, get_input ()) != 1)
> + abort ();
> + return 0;
> +}
>
>
--
Richard Guenther <rguent...@suse.de>
SUSE / SUSE Labs
SUSE LINUX Products GmbH - Nuernberg - AG Nuernberg - HRB 16746
GF: Jeff Hawn, Jennifer Guild, Felix Imendörffer
