[PATCH v2] Fix PR79908

[Bill Schmidt]

On Mar 21, 2017, at 10:18 AM, Christophe Lyon <christophe.lyon@linaro.org> wrote:
> 
> Since this was committed (r246319), I've noticed that
> GCC cross-compiler fails to build glibc for target aarch64-linux-gnu.
> 
> I'm seeing:
> In function '_IO_vfscanf_internal':
> cc1: internal compiler error: in gimplify_modify_expr, at gimplify.c:5627
> 0x8ae5bf gimplify_modify_expr
>        /tmp/1882393_6.tmpdir/aci-gcc-fsf/sources/gcc-fsf/gccsrc/gcc/gimplify.c:5627
> 0x8902b4 gimplify_expr(tree_node**, gimple**, gimple**, bool
> (*)(tree_node*), int)
>        /tmp/1882393_6.tmpdir/aci-gcc-fsf/sources/gcc-fsf/gccsrc/gcc/gimplify.c:11198
> 0x8963c8 gimplify_stmt(tree_node**, gimple**)
>        /tmp/1882393_6.tmpdir/aci-gcc-fsf/sources/gcc-fsf/gccsrc/gcc/gimplify.c:6477
> 0x89bf55 gimplify_cond_expr
>        /tmp/1882393_6.tmpdir/aci-gcc-fsf/sources/gcc-fsf/gccsrc/gcc/gimplify.c:3971
> 0x890273 gimplify_expr(tree_node**, gimple**, gimple**, bool
> (*)(tree_node*), int)
>        /tmp/1882393_6.tmpdir/aci-In function '_IO_vfscanf_internal':
> cc1: internal compiler error: in gimplify_modify_expr, at gimplify.c:5627
> 0x8ae5bf gimplify_modify_expr
>        /tmp/1882393_6.tmpdir/aci-gcc-fsf/sources/gcc-fsf/gccsrc/gcc/gimplify.c:5627
> 0x8902b4 gimplify_expr(tree_node**, gimple**, gimple**, bool
> (*)(tree_node*), int)
>        /tmp/1882393_6.tmpdir/aci-gcc-fsf/sources/gcc-fsf/gccsrc/gcc/gimplify.c:11198
> 0x8963c8 gimplify_stmt(tree_node**, gimple**)
>        /tmp/1882393_6.tmpdir/aci-gcc-fsf/sources/gcc-fsf/gccsrc/gcc/gimplify.c:6477
> 0x89bf55 gimplify_cond_expr
>        /tmp/1882393_6.tmpdir/aci-gcc-fsf/sources/gcc-fsf/gccsrc/gcc/gimplify.c:3971
> 0x890273 gimplify_expr(tree_node**, gimple**, gimple**, bool
> (*)(tree_node*), int)
>        /tmp/1882393_6.tmpdir/aci-gcc-fsf/sources/gcc-fsf/gccsrc/gcc/gimplify.c:11154
> 0x8963c8 gimplify_stmt(tree_node**, gimple**)
>        /tmp/1882393_6.tmpdir/aci-gcc-fsf/sources/gcc-fsf/gccsrc/gcc/gimplify.c:6477
> 0x89b803 gimplify_cond_expr
>        /tmp/1882393_6.tmpdir/aci-gcc-fsf/sources/gcc-fsf/gccsrc/gcc/gimplify.c:3864
> 0x890273 gimplify_expr(tree_node**, gimple**, gimple**, bool
> (*)(tree_node*), int)
>        /tmp/1882393_6.tmpdir/aci-gcc-fsf/sources/gcc-fsf/gccsrc/gcc/gimplify.c:11154
> 0x89328f gimplify_expr(tree_node**, gimple**, gimple**, bool
> (*)(tree_node*), int)
>        /tmp/1882393_6.tmpdir/aci-gcc-fsf/sources/gcc-fsf/gccsrc/gcc/gimplify.c:11356
> 0x8b49f9 force_gimple_operand_1(tree_node*, gimple**, bool
> (*)(tree_node*), tree_node*)
>        /tmp/1882393_6.tmpdir/aci-gcc-fsf/sources/gcc-fsf/gccsrc/gcc/gimplify-me.c:78
> 0xda0f16 expand_ifn_va_arg_1
>        /tmp/1882393_6.tmpdir/aci-gcc-fsf/sources/gcc-fsf/gccsrc/gcc/tree-stdarg.c:1064
> 0xda0f16 expand_ifn_va_arg
>        /tmp/1882393_6.tmpdir/aci-gcc-fsf/sources/gcc-fsf/gccsrc/gcc/tree-stdarg.c:1105
> 0xda494b execute
>        /tmp/1882393_6.tmpdir/aci-gcc-fsf/sources/gcc-fsf/gccsrc/gcc/tree-stdarg.c:1158
> gcc-fsf/sources/gcc-fsf/gccsrc/gcc/gimplify.c:11154
> 0x8963c8 gimplify_stmt(tree_node**, gimple**)
>        /tmp/1882393_6.tmpdir/aci-gcc-fsf/sources/gcc-fsf/gccsrc/gcc/gimplify.c:6477
> 0x89b803 gimplify_cond_expr
>        /tmp/1882393_6.tmpdir/aci-gcc-fsf/sources/gcc-fsf/gccsrc/gcc/gimplify.c:3864
> 0x890273 gimplify_expr(tree_node**, gimple**, gimple**, bool
> (*)(tree_node*), int)
>        /tmp/1882393_6.tmpdir/aci-gcc-fsf/sources/gcc-fsf/gccsrc/gcc/gimplify.c:11154
> 0x89328f gimplify_expr(tree_node**, gimple**, gimple**, bool
> (*)(tree_node*), int)
>        /tmp/1882393_6.tmpdir/aci-gcc-fsf/sources/gcc-fsf/gccsrc/gcc/gimplify.c:11356
> 0x8b49f9 force_gimple_operand_1(tree_node*, gimple**, bool
> (*)(tree_node*), tree_node*)
>        /tmp/1882393_6.tmpdir/aci-gcc-fsf/sources/gcc-fsf/gccsrc/gcc/gimplify-me.c:78
> 0xda0f16 expand_ifn_va_arg_1
>        /tmp/1882393_6.tmpdir/aci-gcc-fsf/sources/gcc-fsf/gccsrc/gcc/tree-stdarg.c:1064
> 0xda0f16 expand_ifn_va_arg
>        /tmp/1882393_6.tmpdir/aci-gcc-fsf/sources/gcc-fsf/gccsrc/gcc/tree-stdarg.c:1105
> 0xda494b execute
>        /tmp/1882393_6.tmpdir/aci-gcc-fsf/sources/gcc-fsf/gccsrc/gcc/tree-stdarg.c:1158
> 
> 
> I can start a manual build if you need a .i file.

Yes, please!  Please open a PR for tracking and CC me (wschmidt@gcc.gnu.org); I'll investigate.

Bill

> 
> Thanks,
> 
> Christophe
> 
>> Thanks,
>> Richard.
>> 
>>> Thanks,
>>> Bill
>>> 
>>> 
>>> [gcc]
>>> 
>>> 2017-03-20  Bill Schmidt  <wschmidt@linux.vnet.ibm.com>
>>>            Richard Biener  <rguenth@suse.com>
>>> 
>>>        PR tree-optimization/79908
>>>        * tree-stdarg.c (expand_ifn_va_arg_1): For a VA_ARG whose LHS has
>>>        been cast away, use force_gimple_operand to construct the side
>>>        effects.
>>> 
>>> [gcc/testsuite]
>>> 
>>> 2017-03-20  Bill Schmidt  <wschmidt@linux.vnet.ibm.com>
>>>            Richard Biener  <rguenther@suse.de>
>>> 
>>>        PR tree-optimization/79908
>>>        * gcc.dg/torture/pr79908.c: New file.
>>> 
>>> 
>>> Index: gcc/testsuite/gcc.dg/torture/pr79908.c
>>> ===================================================================
>>> --- gcc/testsuite/gcc.dg/torture/pr79908.c      (nonexistent)
>>> +++ gcc/testsuite/gcc.dg/torture/pr79908.c      (working copy)
>>> @@ -0,0 +1,12 @@
>>> +/* { dg-do compile } */
>>> +
>>> +/* Used to fail in the stdarg pass before fix for PR79908.  */
>>> +
>>> +typedef __builtin_va_list __gnuc_va_list;
>>> +typedef __gnuc_va_list va_list;
>>> +
>>> +void testva (int n, ...)
>>> +{
>>> +  va_list ap;
>>> +  _Complex int i = __builtin_va_arg (ap, _Complex int);
>>> +}
>>> Index: gcc/tree-stdarg.c
>>> ===================================================================
>>> --- gcc/tree-stdarg.c   (revision 246286)
>>> +++ gcc/tree-stdarg.c   (working copy)
>>> @@ -33,6 +33,7 @@ along with GCC; see the file COPYING3.  If not see
>>> #include "gimple-iterator.h"
>>> #include "gimple-walk.h"
>>> #include "gimplify.h"
>>> +#include "gimplify-me.h"
>>> #include "tree-into-ssa.h"
>>> #include "tree-cfg.h"
>>> #include "tree-stdarg.h"
>>> @@ -1058,12 +1059,16 @@ expand_ifn_va_arg_1 (function *fun)
>>>            gimplify_assign (lhs, expr, &pre);
>>>          }
>>>        else
>>> -         gimplify_expr (&expr, &pre, &post, is_gimple_lvalue, fb_lvalue);
>>> +         {
>>> +           gimple_seq tmp_seq;
>>> +           force_gimple_operand (expr, &tmp_seq, false, NULL_TREE);
>>> +           gimple_seq_add_seq_without_update (&pre, tmp_seq);
>>> +         }
>>> 
>>>        input_location = saved_location;
>>>        pop_gimplify_context (NULL);
>>> 
>>> -       gimple_seq_add_seq (&pre, post);
>>> +       gimple_seq_add_seq_without_update (&pre, post);
>>>        update_modified_stmts (pre);
>>> 
>>>        /* Add the sequence after IFN_VA_ARG.  This splits the bb right
>>> @@ -1072,11 +1077,10 @@ expand_ifn_va_arg_1 (function *fun)
>>>        gimple_find_sub_bbs (pre, &i);
>>> 
>>>        /* Remove the IFN_VA_ARG gimple_call.  It's the last stmt in the
>>> -          bb.  */
>>> +          bb if we added any stmts.  */
>>>        unlink_stmt_vdef (stmt);
>>>        release_ssa_name_fn (fun, gimple_vdef (stmt));
>>>        gsi_remove (&i, true);
>>> -       gcc_assert (gsi_end_p (i));
>>> 
>>>        /* We're walking here into the bbs which contain the expansion of
>>>           IFN_VA_ARG, and will not contain another IFN_VA_ARG that needs
>>> 
>