[PATCH] clear more front end VLA bounds from IL (PR 97172)

[Christophe Lyon]

Hi,



On Wed, 24 Feb 2021 at 09:57, Richard Biener via Gcc-patches
<gcc-patches@gcc.gnu.org> wrote:
>
> On Tue, Feb 23, 2021 at 8:53 PM Martin Sebor via Gcc-patches
> <gcc-patches@gcc.gnu.org> wrote:
> >
> > Adding attribute access to declarations of functions that take
> > VLA arguments relies on the front end adding attribute "arg spec"
> > to each VLA parameter.  Like the VLA bounds in attribute access,
> > the same VLA bounds in attribute "arg spec" can cause trouble
> > during LTO streaming which expects front end trees to have been
> > either gimplified or removed.  For some reason, with arg spec
> > the LTO abort happens only with -fpic/-shared and so it escaped
> > testing in the prior fixes.
> >
> > The attached patch clears the bounds from attribute "arg spec."
>
> OK.


I committed the patch below as obvious, to avoid failures on targets
where -shared is not supported.
This happens on Arm where the multilibs are not compiled with -fpic
and link fails because
some relocations are generated which are incompatible with -shared.

commit 01c2ce169a05c8e59c4182796876f7e0754e4b5c
Author: Christophe Lyon <christophe.lyon@linaro.org>
Date:   Thu Feb 25 15:55:28 2021 +0000

    PR middle-end/97172 - ICE: tree code 'ssa_name' is not supported
in LTO streams

    Skip test when -shared is not supported.

    2021-02-25  Christophe Lyon  <christophe.lyon@linaro.org>

        gcc/testsuite/
        PR middle-end/97172
        * gcc.dg/pr97172-2.c: Add dg-require-effective-target shared.

diff --git a/gcc/testsuite/gcc.dg/pr97172-2.c b/gcc/testsuite/gcc.dg/pr97172-2.c
index 6f355bb..99cc6c2 100644
--- a/gcc/testsuite/gcc.dg/pr97172-2.c
+++ b/gcc/testsuite/gcc.dg/pr97172-2.c
@@ -3,6 +3,7 @@
    { dg-do link }
    { dg-options "-Wall -flto -fpic -shared" }
    { dg-require-effective-target fpic }
+   { dg-require-effective-target shared }
    { dg-require-effective-target lto } */

 #include "pr97172.c"

Christophe

>
> Richard.
>
> > Martin