[FFmpeg-devel] [PATCH] configure: Fix Microsoft tools detection

[Hendrik Leppkes]

On Thu, Feb 3, 2022 at 12:34 PM Martin Storsjö <martin at martin.st> wrote:
>
> On Thu, 3 Feb 2022, Kacper Michajlow wrote:
>
> > On Wed, 26 Jan 2022 at 15:00, Martin Storsjö <martin at martin.st> wrote:
> >>
> >> Hi,
> >>
> >> On Sat, 22 Jan 2022, Kacper Michajłow wrote:
> >>
> >>> LLVM tools print installation path upon execution. If one uses LLVM
> >>> tools bundled with Microsoft Visual Studio installation, they would be
> >>> incorrectly detected as Microsoft's ones.
> >>>
> >>> Signed-off-by: Kacper Michajłow <kasper93 at gmail.com>
> >>> ---
> >>> configure | 6 +++---
> >>> 1 file changed, 3 insertions(+), 3 deletions(-)
> >>
> >> While the patch description seems to make sense, I wanted to try it out to
> >> see the practical effect for myself, and I fail to observe any difference.
> >>
> >> Can you provide your exact configure command line you use, where it makes
> >> a difference? I tried with "--cc=clang-cl --ld=lld-link --toolchain=msvc"
> >> and that works just as fine before this patch.
> >>
> >> In particular, the commands that you adjust run "$_cc -nologo-" and grep
> >> for "Microsoft" in the output of that. When I run that with clang-cl, it
> >> doesn't print a string containing "Microsoft".
> >>
> >> // Martin
> >
> > Hi,
> >
> > Yes you are right. In case of CC it doesn't change anything. clang-cl
> > prints installation dir only with `-v`. The main thing this patch
> > fixes is `--ar=llvm-ar` where it is mistaken for lib.exe and used with
> > wrong parameters. While fixing this I figured to make CC check also
> > more strict, because at some point it could be a problem. Sync all of
> > them to have same style as one that was already there
>
> Oh, ok, with the reference to llvm-ar, I see what it fixes. Thanks! The
> reference to llvm-ar absolutely needs to be in the patch description then.
>
> I remember that there has been some variance throughout the versions for
> exactly what MSVC prints as the identification thoughout the versions, but
> I think 'Microsoft.*Optimizing.*Compiler' should be safe.
>

I was wondering if non-english locale would translate that string, but
I can't easily test that, I don't think.

- Hendrik