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

[Kacper Michajlow]

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
> elif $_cc 2>&1 | grep -q 'Microsoft.*ARM.*Assembler'; then

just for consistency...

Also I noticed that latest MSVC (19.30.30709) complains about
> cl : Command line warning D9035 : option 'nologo-' has been deprecated and will be removed in a future release

But it doesn't affect anything, even if it were to be removed. Since
banner is shown always by default, unless `-nologo`. Just a side note
:)

-Kacper