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

[Michael Niedermayer]

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

[...]

-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Observe your enemies, for they first find out your faults. -- Antisthenes
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