On Wed, 26 Nov 2014, Jakub Jelinek wrote:
> Hi!
>
> The testcase shows that when expanding ARRAY_REF from a const static var
> with initializer that contains COMPOUND_LITERAL_EXPR, we can try to expand
> COMPOUND_LITERAL_EXPR even when modifier is not EXPAND_INITIALIZER (it is
> EXPAND_SUM in that testcase, but could be many others).
> While gimplification should get rid of all the compound literal exprs
> for automatic compound literals, COMPOUND_LITERAL_EXPR for static compound
> literals can survive in the initializers, thus this patch handles them
> always.
>
> Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
Ok. (I wonder if the fallthru still makes sense or if we should
hit a gcc_unreachable () for other uses of COMPOUND_LITERAL_EXPR).
Thanks,
Richard.
> 2014-11-26 Jakub Jelinek <ja...@redhat.com>
>
> PR middle-end/64067
> * expr.c (expand_expr_addr_expr_1) <case COMPOUND_LITERAL_EXPR>:
> Handle it by returning address of COMPOUND_LITERAL_EXPR_DECL
> not only if modifier is EXPAND_INITIALIZER, but whenever
> COMPOUND_LITERAL_EXPR_DECL is non-NULL and TREE_STATIC.
>
> * gcc.c-torture/compile/pr64067.c: New test.
>
> --- gcc/expr.c.jj 2014-11-18 08:26:45.000000000 +0100
> +++ gcc/expr.c 2014-11-26 17:38:52.877675088 +0100
> @@ -7677,11 +7677,13 @@ expand_expr_addr_expr_1 (tree exp, rtx t
> break;
>
> case COMPOUND_LITERAL_EXPR:
> - /* Allow COMPOUND_LITERAL_EXPR in initializers, if e.g.
> - rtl_for_decl_init is called on DECL_INITIAL with
> - COMPOUNT_LITERAL_EXPRs in it, they aren't gimplified. */
> - if (modifier == EXPAND_INITIALIZER
> - && COMPOUND_LITERAL_EXPR_DECL (exp))
> + /* Allow COMPOUND_LITERAL_EXPR in initializers or coming from
> + initializers, if e.g. rtl_for_decl_init is called on DECL_INITIAL
> + with COMPOUND_LITERAL_EXPRs in it, or ARRAY_REF on a const static
> + array with address of COMPOUND_LITERAL_EXPR in DECL_INITIAL;
> + the initializers aren't gimplified. */
> + if (COMPOUND_LITERAL_EXPR_DECL (exp)
> + && TREE_STATIC (COMPOUND_LITERAL_EXPR_DECL (exp)))
> return expand_expr_addr_expr_1 (COMPOUND_LITERAL_EXPR_DECL (exp),
> target, tmode, modifier, as);
> /* FALLTHRU */
> --- gcc/testsuite/gcc.c-torture/compile/pr64067.c.jj 2014-11-26
> 17:37:37.835865797 +0100
> +++ gcc/testsuite/gcc.c-torture/compile/pr64067.c 2014-11-26
> 17:37:02.000000000 +0100
> @@ -0,0 +1,10 @@
> +/* PR middle-end/64067 */
> +
> +struct S { int s; };
> +int *const v[1] = { &((struct S) { .s = 42 }).s };
> +
> +int *
> +foo (void)
> +{
> + return v[0];
> +}
>
> Jakub
>
>
--
Richard Biener <rguent...@suse.de>
SUSE LINUX GmbH, GF: Jeff Hawn, Jennifer Guild, Felix Imendoerffer, HRB 21284
(AG Nuernberg)
Maxfeldstrasse 5, 90409 Nuernberg, Germany
