On Thu, Apr 16, 2015 at 11:11 PM, Jakub Jelinek <ja...@redhat.com> wrote:
> Hi!
>
> As mentioned in the PR, on the following testcase we ICE, because for
> # DEBUG D#2 => b
> # DEBUG D#1 => a[D#2].t
> # DEBUG c => D#1
> during expansion we get the a[D#2].t added as MEM_EXPR of a MEM, and because
> we can't mem_loc_descriptor that MEM (I'll post separately a trunk only
> patch that fixes that in this case, but generally not all MEMs can be
> represented in debug info), we try harder and try to use MEM_EXPR in
> loc_list_from_tree, but that one ICEs on DEBUG_EXPR_DECL. There is nothing
> we can do for those at this point, debug_exprs are only useful to
> var-tracking, so returning NULL is the only thing we can do for those.
>
> Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk and 5.1?
Ok.
Thanks,
Richard.
> 2015-04-16 Jakub Jelinek <ja...@redhat.com>
>
> PR debug/65771
> * dwarf2out.c (loc_list_from_tree): Return NULL
> for DEBUG_EXPR_DECL.
>
> * gcc.dg/debug/pr65771.c: New test.
>
> --- gcc/dwarf2out.c.jj 2015-04-16 16:51:52.000000000 +0200
> +++ gcc/dwarf2out.c 2015-04-16 16:57:28.866134980 +0200
> @@ -14642,6 +14642,7 @@ loc_list_from_tree (tree loc, int want_a
>
> case TARGET_MEM_REF:
> case SSA_NAME:
> + case DEBUG_EXPR_DECL:
> return NULL;
>
> case COMPOUND_EXPR:
> --- gcc/testsuite/gcc.dg/debug/pr65771.c.jj 2015-04-16 17:00:23.811328842
> +0200
> +++ gcc/testsuite/gcc.dg/debug/pr65771.c 2015-04-16 17:00:13.000000000
> +0200
> @@ -0,0 +1,15 @@
> +/* PR debug/65771 */
> +/* { dg-do link } */
> +/* { dg-require-effective-target tls } */
> +
> +struct S { int s; int t; };
> +__thread struct S a[10];
> +int b;
> +
> +int
> +main ()
> +{
> + int c = a[b].t;
> + (void) c;
> + return 0;
> +}
>
> Jakub
