[FFmpeg-devel] [PATCH] configure: force erroring out in check_disable_warning() if an option doesn't exists

[James Almer]

On 10/13/2017 8:54 PM, Michael Niedermayer wrote:
> On Fri, Oct 13, 2017 at 12:37:18PM -0300, James Almer wrote:
>> On 10/13/2017 11:30 AM, Hendrik Leppkes wrote:
>>> On Fri, Oct 13, 2017 at 4:14 PM, James Almer <jamrial at gmail.com> wrote:
>>>> On 10/12/2017 6:30 PM, James Almer wrote:
>>>>> Should prevent some options from being added to cflags when they
>>>>> don't exist and the compiler only warns about it.
>>>>>
>>>>> Signed-off-by: James Almer <jamrial at gmail.com>
>>>>> ---
>>>>> I figure this is safer than adding
>>>>> -Werror=unused-command-line-argument -Werror=unknown-warning-option
>>>>> as Ronald suggested.
>>>>>
>>>>>  configure | 2 +-
>>>>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>>>>
>>>>> diff --git a/configure b/configure
>>>>> index ade67a31bb..c7962665f1 100755
>>>>> --- a/configure
>>>>> +++ b/configure
>>>>> @@ -6370,7 +6370,7 @@ fi
>>>>>
>>>>>  check_disable_warning(){
>>>>>      warning_flag=-W${1#-Wno-}
>>>>> -    test_cflags $warning_flag && add_cflags $1
>>>>> +    test_cflags -Werror $warning_flag && add_cflags $1
>>>>>  }
>>>>>
>>>>>  check_disable_warning -Wno-parentheses
>>>>
>>>> Ping. This or a similar solution has been annoying Clang users for some
>>>> days now and should be part of the 3.4 release.
>>>
>>> I wonder if a general -Werror is really "safer", do these tests really
>>> execute without any other warnings, which might trigger a false
>>> negative? We're not exactly making it compile a proper source file, so
>>> it might warn about random things.
>>>
>>> - Hendrik
>>
>> Ok, what about the attached patch, then?
>>
>> Both -Werror=unused-command-line-argument and
>> -Werror=unknown-warning-option are not supported by gcc, so they
>> generate an error and would break every check.
>> This hopefully only uses them where they exist.
> 
>>  configure |    7 ++++++-
>>  1 file changed, 6 insertions(+), 1 deletion(-)
>> 11cd9cc220b675d4cbe171b61c969e024458afad  0001-configure-force-erroring-out-in-check_disable_warnin.patch
>> From 0e305676e6b30ed3274fcbb4f31e318d41cac66d Mon Sep 17 00:00:00 2001
>> From: James Almer <jamrial at gmail.com>
>> Date: Fri, 13 Oct 2017 12:34:34 -0300
>> Subject: [PATCH] configure: force erroring out in check_disable_warning() if
>>  an option doesn't exists
>>
>> Should prevent some options from being added to cflags when they
>> don't exist and the compiler only warns about it.
>>
>> Signed-off-by: James Almer <jamrial at gmail.com>
>> ---
>>  configure | 7 ++++++-
>>  1 file changed, 6 insertions(+), 1 deletion(-)
> 
> iam a bit surprised this has not been fixed long ago
> but LGTM

Applied and backported, thanks!