Re: [Qemu-devel] [PATCH v3 2/4] configure: factor out supported flag check

[John Snow <jsnow@redhat.com>]

On 03/23/2015 09:03 AM, Stefan Hajnoczi wrote:
> On Thu, Mar 19, 2015 at 03:01:35PM -0400, John Snow wrote:
>> +cc_has_warning_flag() {
>> +    if [ "$2" != "--keep-tmpc" ]; then
>> +        write_c_skeleton;
>> +    fi
>> +
>>       # Use the positive sense of the flag when testing for -Wno-wombat
>>       # support (gcc will happily accept the -Wno- form of unknown
>>       # warning options).
>> -    optflag="$(echo $flag | sed -e 's/^-Wno-/-W/')"
>> -    if compile_prog "-Werror $optflag" "" ; then
>> -	QEMU_CFLAGS="$QEMU_CFLAGS $flag"
>> +    optflag="$(echo $1 | sed -e 's/^-Wno-/-W/')"
>> +    compile_prog "-Werror $optflag" ""
>> +}
>> +
>> +write_c_skeleton;
>> +for flag in $gcc_flags; do
>> +    if cc_has_warning_flag $flag --keep-tmpc; then
>
> The only caller that uses --keep-tmpc wants TMPC to be the skeleton
> program anyway.  The option can be dropped and the write_c_skeleton in
> cc_has_warning_flag can be unconditional.
>
> Stefan
>

I just figured there was no use in rewriting the same skeleton file 
unconditionally in a loop.

The helper is used later where we do want to regenerate the skeleton.

If you still want me to just make it unconditional, I can, but I don't 
see the point.

--js