On Tue, 5 Nov 2019, Jakub Jelinek wrote:
> Hi!
>
> On VLAs with register only constraints we ICE, because during gimplification
> we try to create temporaries for them and force_constant_size aborts in that
> case.
>
> The following patch diagnoses those early, like we diagnose already C++
> non-PODs.
>
> Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
>
> 2019-11-05 Jakub Jelinek <ja...@redhat.com>
>
> PR inline-asm/92352
> * gimplify.c (gimplify_asm_expr): Reject VLA in output or input
> operands with non-memory constraints.
>
> * c-c++-common/pr92352.c: New test.
>
> --- gcc/gimplify.c.jj 2019-11-02 10:00:59.595253274 +0100
> +++ gcc/gimplify.c 2019-11-05 00:21:01.585958514 +0100
> @@ -6235,8 +6235,14 @@ gimplify_asm_expr (tree *expr_p, gimple_
> is_inout = false;
> }
>
> - /* If we can't make copies, we can only accept memory. */
> - if (TREE_ADDRESSABLE (TREE_TYPE (TREE_VALUE (link))))
> + /* If we can't make copies, we can only accept memory.
> + Similarly for VLAs. */
> + tree outtype = TREE_TYPE (TREE_VALUE (link));
> + if (outtype != error_mark_node
so for error_mark_node we don't diagnose anything?
> + && (TREE_ADDRESSABLE (outtype)
> + || !COMPLETE_TYPE_P (outtype)
> + || (!tree_fits_poly_uint64_p (TYPE_SIZE_UNIT (outtype))
> + && max_int_size_in_bytes (outtype))))
so max_int_size_in_bytes == 0 is OK? I suppose we have a testcase
for this?
Otherwise looks reasonable to me.
Thanks,
Richard.
> {
> if (allows_mem)
> allows_reg = 0;
> @@ -6392,7 +6398,12 @@ gimplify_asm_expr (tree *expr_p, gimple_
> oconstraints, &allows_mem, &allows_reg);
>
> /* If we can't make copies, we can only accept memory. */
> - if (TREE_ADDRESSABLE (TREE_TYPE (TREE_VALUE (link))))
> + tree intype = TREE_TYPE (TREE_VALUE (link));
> + if (intype != error_mark_node
> + && (TREE_ADDRESSABLE (intype)
> + || !COMPLETE_TYPE_P (intype)
> + || (!tree_fits_poly_uint64_p (TYPE_SIZE_UNIT (intype))
> + && max_int_size_in_bytes (intype))))
> {
> if (allows_mem)
> allows_reg = 0;
> --- gcc/testsuite/c-c++-common/pr92352.c.jj 2019-11-04 14:03:18.725275255
> +0100
> +++ gcc/testsuite/c-c++-common/pr92352.c 2019-11-04 14:02:55.211629675
> +0100
> @@ -0,0 +1,15 @@
> +/* PR inline-asm/92352 */
> +
> +void
> +foo (int x)
> +{
> + int var[x];
> + asm volatile ("" : "+r" (var)); /* { dg-error "impossible constraint in
> 'asm'" } */
> +} /* { dg-error "non-memory output 0 must
> stay in memory" "" { target *-*-* } .-1 } */
> +
> +void
> +bar (int x)
> +{
> + int var[x];
> + asm volatile ("" : "+m" (var));
> +}
>
> Jakub
>
>
--
Richard Biener <rguent...@suse.de>
SUSE Software Solutions Germany GmbH, Maxfeldstrasse 5, 90409 Nuernberg,
Germany; GF: Felix Imendörffer; HRB 36809 (AG Nuernberg)
