Fix up ICE with initializer containing address of invalid var (PR tree-optimization/69483)

Hi!

If as in the testcase below a VAR_DECL has error_mark_node type
(and that unfortunately happens (and has to) quite late, at the end of
parsing the TU), canonicalize_constructor_val can ICE on that, because it
will try to fold convert something to error_mark_node type.

Fixed by giving up in that case.
The patch also cleans up the change that introduced the error_mark_node in
there, to use FOR_EACH_VEC_ELT.

Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?

2016-01-26  Jakub Jelinek  <jakub@redhat.com>

	PR tree-optimization/69483
	* gimple-fold.c (canonicalize_constructor_val): Return NULL
	if base has error_mark_node type.

	* c-parser.c (c_parser_translation_unit): Use FOR_EACH_VEC_ELT.

	* gcc.dg/pr69483.c: New test.
	* g++.dg/opt/pr69483.C: New test.


	Jakub

On Tue, Jan 26, 2016 at 3:17 PM, Jakub Jelinek <jakub@redhat.com> wrote:
> Hi!
>
> If as in the testcase below a VAR_DECL has error_mark_node type
> (and that unfortunately happens (and has to) quite late, at the end of
> parsing the TU), canonicalize_constructor_val can ICE on that, because it
> will try to fold convert something to error_mark_node type.
>
> Fixed by giving up in that case.
> The patch also cleans up the change that introduced the error_mark_node in
> there, to use FOR_EACH_VEC_ELT.
>
> Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?

Ok.

Thanks,
Richard.

> 2016-01-26  Jakub Jelinek  <jakub@redhat.com>
>
>         PR tree-optimization/69483
>         * gimple-fold.c (canonicalize_constructor_val): Return NULL
>         if base has error_mark_node type.
>
>         * c-parser.c (c_parser_translation_unit): Use FOR_EACH_VEC_ELT.
>
>         * gcc.dg/pr69483.c: New test.
>         * g++.dg/opt/pr69483.C: New test.
>
> --- gcc/gimple-fold.c.jj        2016-01-08 21:48:36.000000000 +0100
> +++ gcc/gimple-fold.c   2016-01-26 10:54:12.142355308 +0100
> @@ -195,6 +195,8 @@ canonicalize_constructor_val (tree cval,
>            || TREE_CODE (base) == FUNCTION_DECL)
>           && !can_refer_decl_in_current_unit_p (base, from_decl))
>         return NULL_TREE;
> +      if (TREE_TYPE (base) == error_mark_node)
> +       return NULL_TREE;
>        if (TREE_CODE (base) == VAR_DECL)
>         TREE_ADDRESSABLE (base) = 1;
>        else if (TREE_CODE (base) == FUNCTION_DECL)
> --- gcc/c/c-parser.c.jj 2016-01-21 00:41:47.000000000 +0100
> +++ gcc/c/c-parser.c    2016-01-26 10:59:30.104941374 +0100
> @@ -1431,15 +1431,14 @@ c_parser_translation_unit (c_parser *par
>        while (c_parser_next_token_is_not (parser, CPP_EOF));
>      }
>
> -  for (unsigned i = 0; i < incomplete_record_decls.length (); ++i)
> -    {
> -      tree decl = incomplete_record_decls[i];
> -      if (DECL_SIZE (decl) == NULL_TREE && TREE_TYPE (decl) != error_mark_node)
> -       {
> -         error ("storage size of %q+D isn%'t known", decl);
> -         TREE_TYPE (decl) = error_mark_node;
> -       }
> -    }
> +  unsigned int i;
> +  tree decl;
> +  FOR_EACH_VEC_ELT (incomplete_record_decls, i, decl)
> +    if (DECL_SIZE (decl) == NULL_TREE && TREE_TYPE (decl) != error_mark_node)
> +      {
> +       error ("storage size of %q+D isn%'t known", decl);
> +       TREE_TYPE (decl) = error_mark_node;
> +      }
>  }
>
>  /* Parse an external declaration (C90 6.7, C99 6.9).
> --- gcc/testsuite/gcc.dg/pr69483.c.jj   2016-01-26 11:02:41.152289108 +0100
> +++ gcc/testsuite/gcc.dg/pr69483.c      2016-01-26 11:02:20.000000000 +0100
> @@ -0,0 +1,6 @@
> +/* PR tree-optimization/69483 */
> +/* { dg-do compile } */
> +
> +struct T { struct S *a; };
> +struct S b; /* { dg-error "storage size of 'b' isn't known" } */
> +struct T c = { &b };
> --- gcc/testsuite/g++.dg/opt/pr69483.C.jj       2016-01-26 11:06:03.375481313 +0100
> +++ gcc/testsuite/g++.dg/opt/pr69483.C  2016-01-26 11:03:20.000000000 +0100
> @@ -0,0 +1,6 @@
> +// PR tree-optimization/69483
> +// { dg-do compile }
> +
> +struct T { struct S *a; };
> +struct S b; // { dg-error "aggregate 'S b' has incomplete type and cannot be defined" }
> +struct T c = { &b };
>
>         Jakub