Re: [PATCH, PR67405, committed] Avoid NULL pointer dereference

[Richard Biener <richard.guenther@gmail.com>]

On Tue, Sep 1, 2015 at 5:03 PM, Ilya Enkovich <enkovich.gnu@gmail.com> wrote:
> Hi,
>
> This fixes an ICE by adding a NULL check.  Bootstrapped and regtested for x86_64-unknown-linux-gnu.  Applied to trunk.  Does this need to be ported to gcc-5-branch?
>
> Thanks,
> Ilya
> --
> gcc/
>
> 2015-09-01  Ilya Enkovich  <enkovich.gnu@gmail.com>
>
>         PR target/67405
>         * tree-chkp.c (chkp_find_bound_slots_1): Add NULL check.
>
> gcc/testsuite/
>
> 2015-09-01  Ilya Enkovich  <enkovich.gnu@gmail.com>
>
>         PR target/67405
>         * g++.dg/pr67405.C: New test.
>
>
> diff --git a/gcc/testsuite/g++.dg/pr67405.C b/gcc/testsuite/g++.dg/pr67405.C
> new file mode 100644
> index 0000000..5055921
> --- /dev/null
> +++ b/gcc/testsuite/g++.dg/pr67405.C
> @@ -0,0 +1,11 @@
> +// { dg-do compile }
> +
> +struct S
> +{
> +  S f; // { dg-error "incomplete type" }
> +};
> +
> +void
> +fn1 (S p1)
> +{
> +}
> diff --git a/gcc/tree-chkp.c b/gcc/tree-chkp.c
> index 8c1b48c..2489abb 100644
> --- a/gcc/tree-chkp.c
> +++ b/gcc/tree-chkp.c
> @@ -1667,8 +1667,9 @@ chkp_find_bound_slots_1 (const_tree type, bitmap have_bound,
>        for (field = TYPE_FIELDS (type); field; field = DECL_CHAIN (field))
>         if (TREE_CODE (field) == FIELD_DECL)
>           {
> -           HOST_WIDE_INT field_offs
> -             = TREE_INT_CST_LOW (DECL_FIELD_BIT_OFFSET (field));
> +           HOST_WIDE_INT field_offs = 0;
> +           if (DECL_FIELD_BIT_OFFSET (field))

DECL_FIELD_BIT_OFFSET should be never NULL.  Whoever created that
FIELD_DECL created an invalid one.

Richard.

> +             field_offs += TREE_INT_CST_LOW (DECL_FIELD_BIT_OFFSET (field));
>             if (DECL_FIELD_OFFSET (field))
>               field_offs += TREE_INT_CST_LOW (DECL_FIELD_OFFSET (field)) * 8;
>             chkp_find_bound_slots_1 (TREE_TYPE (field), have_bound,