On Tue, 3 Dec 2013, Jakub Jelinek wrote:
> Hi!
>
> tree-nested.c uses declare_vars with last argument true, which
> relies on BLOCK_VARS of gimple_bind_block being a tail
> of the gimple_bind_vars chain. But unfortunately a debug info
> improvement I've added to gimplify_var_or_parm_decl 4 years ago
> violates this assumption, in that it adds some VAR_DECLs
> at the head of BLOCK_VARS (DECL_INITIAL (current_function_decl))
> chain, but doesn't adjust gimple_bind_vars chain correspondingly.
>
> Fixed thusly, bootstrapped/regtested on x86_64-linux and i686-linux,
> ok for trunk/4.8?
Ok.
Thanks,
Richard.
> 2013-12-02 Jakub Jelinek <ja...@redhat.com>
>
> PR middle-end/59011
> * gimplify.c (nonlocal_vla_vars): New variable.
> (gimplify_var_or_parm_decl): Put VAR_DECLs for VLAs into
> nonlocal_vla_vars chain.
> (gimplify_body): Call declare_vars on nonlocal_vla_vars chain
> if outer_bind has DECL_INITIAL (current_function_decl) block.
>
> * gcc.dg/pr59011.c: New test.
>
> --- gcc/gimplify.c.jj 2013-12-02 14:33:34.000000000 +0100
> +++ gcc/gimplify.c 2013-12-02 20:32:02.883491995 +0100
> @@ -1689,6 +1689,9 @@ gimplify_conversion (tree *expr_p)
> /* Nonlocal VLAs seen in the current function. */
> static struct pointer_set_t *nonlocal_vlas;
>
> +/* The VAR_DECLs created for nonlocal VLAs for debug info purposes. */
> +static tree nonlocal_vla_vars;
> +
> /* Gimplify a VAR_DECL or PARM_DECL. Return GS_OK if we expanded a
> DECL_VALUE_EXPR, and it's worth re-examining things. */
>
> @@ -1737,14 +1740,13 @@ gimplify_var_or_parm_decl (tree *expr_p)
> ctx = ctx->outer_context;
> if (!ctx && !pointer_set_insert (nonlocal_vlas, decl))
> {
> - tree copy = copy_node (decl), block;
> + tree copy = copy_node (decl);
>
> lang_hooks.dup_lang_specific_decl (copy);
> SET_DECL_RTL (copy, 0);
> TREE_USED (copy) = 1;
> - block = DECL_INITIAL (current_function_decl);
> - DECL_CHAIN (copy) = BLOCK_VARS (block);
> - BLOCK_VARS (block) = copy;
> + DECL_CHAIN (copy) = nonlocal_vla_vars;
> + nonlocal_vla_vars = copy;
> SET_DECL_VALUE_EXPR (copy, unshare_expr (value_expr));
> DECL_HAS_VALUE_EXPR_P (copy) = 1;
> }
> @@ -8562,6 +8564,21 @@ gimplify_body (tree fndecl, bool do_parm
>
> if (nonlocal_vlas)
> {
> + if (nonlocal_vla_vars)
> + {
> + /* tree-nested.c may later on call declare_vars (..., true);
> + which relies on BLOCK_VARS chain to be the tail of the
> + gimple_bind_vars chain. Ensure we don't violate that
> + assumption. */
> + if (gimple_bind_block (outer_bind)
> + == DECL_INITIAL (current_function_decl))
> + declare_vars (nonlocal_vla_vars, outer_bind, true);
> + else
> + BLOCK_VARS (DECL_INITIAL (current_function_decl))
> + = chainon (BLOCK_VARS (DECL_INITIAL (current_function_decl)),
> + nonlocal_vla_vars);
> + nonlocal_vla_vars = NULL_TREE;
> + }
> pointer_set_destroy (nonlocal_vlas);
> nonlocal_vlas = NULL;
> }
> --- gcc/testsuite/gcc.dg/pr59011.c.jj 2013-12-02 20:14:22.350702153 +0100
> +++ gcc/testsuite/gcc.dg/pr59011.c 2013-12-02 20:15:10.902455660 +0100
> @@ -0,0 +1,22 @@
> +/* PR middle-end/59011 */
> +/* { dg-do compile } */
> +/* { dg-options "-std=gnu99" } */
> +
> +void
> +foo (int m)
> +{
> + int a[m];
> + void
> + bar (void)
> + {
> + {
> + int
> + baz (void)
> + {
> + return a[0];
> + }
> + }
> + a[0] = 42;
> + }
> + bar ();
> +}
>
> Jakub
>
>
--
Richard Biener <rguent...@suse.de>
SUSE / SUSE Labs
SUSE LINUX Products GmbH - Nuernberg - AG Nuernberg - HRB 16746
GF: Jeff Hawn, Jennifer Guild, Felix Imend"orffer
