> On Mar 14, 2017, at 11:07 AM, Bill Schmidt <wschm...@linux.vnet.ibm.com>
> wrote:
>>
>> Your suggestion failed bootstrap in libiberty on vprintf-support.c.
>> Compilation failed with:
>>
>> /home/wschmidt/gcc/build/gcc-mainline-test2-debug/gcc/xgcc
>> -B/home/wschmidt/gcc/build/gcc-mainline-test2-debug/gcc/
>> -B/home/wschmidt/gcc/install/gcc-mainline-test2-debug/powerpc64le-unknown-linux-gnu/bin/
>>
>> -B/home/wschmidt/gcc/install/gcc-mainline-test2-debug/powerpc64le-unknown-linux-gnu/bin/
>>
>> -B/home/wschmidt/gcc/install/gcc-mainline-test2-debug/powerpc64le-unknown-linux-gnu/lib/
>> -isystem
>> /home/wschmidt/gcc/install/gcc-mainline-test2-debug/powerpc64le-unknown-linux-gnu/include
>> -isystem
>> /home/wschmidt/gcc/install/gcc-mainline-test2-debug/powerpc64le-unknown-linux-gnu/sys-include
>> -c -DHAVE_CONFIG_H -g -O2 -gtoggle -I.
>> -I/home/wschmidt/gcc/gcc-mainline-test2/libiberty/../include -W -Wall
>> -Wwrite-strings -Wc++-compat -Wstrict-prototypes -Wshadow=local -pedantic
>> -D_GNU_SOURCE -fPIC
>> /home/wschmidt/gcc/gcc-mainline-test2/libiberty/vprintf-support.c -o
>> pic/vprintf-support.o
>>
>> The initial expression being gimplified is ADDR_EXPR (VAR_DECL (ap)).
>> Gimplification
>> turns this into MEM_REF (VAR_DECL (D.4274), 0), and the is_gimple_val test
>> fails on that.
>
> Reduced test case:
>
> typedef __builtin_va_list __gnuc_va_list;
> typedef __gnuc_va_list va_list;
>
> void
> foo (va_list args)
> {
> va_list ap;
> __builtin_va_copy (ap, args);
> (void)__builtin_va_arg (ap, int);
> __builtin_va_end(ap);
> }
>
Perhaps something like this? It appears to be doing better on bootstrap, and
avoids
failure on both the original problem and the new test case above:
Index: gcc/tree-stdarg.c
===================================================================
--- gcc/tree-stdarg.c (revision 246109)
+++ gcc/tree-stdarg.c (working copy)
@@ -1058,7 +1058,13 @@ expand_ifn_va_arg_1 (function *fun)
gimplify_assign (lhs, expr, &pre);
}
else
- gimplify_expr (&expr, &pre, &post, is_gimple_lvalue, fb_lvalue);
+ {
+ enum gimplify_status status;
+ status = gimplify_expr (&expr, &pre, &post, is_gimple_lvalue,
+ fb_lvalue | fb_mayfail);
+ if (status == GS_ERROR)
+ gimplify_expr (&expr, &pre, &post, is_gimple_val, fb_rvalue);
+ }
input_location = saved_location;
pop_gimplify_context (NULL);
Bill
