[FFmpeg-devel] [PATCH] configure: autodetect libglslang ldflags

[Martin Storsjö]

On Mon, 22 Jan 2024, Timo Rothenpieler wrote:

> On 22/01/2024 07:51, Matthew White via ffmpeg-devel wrote:
>> Since glslang 14.0.0, OGLCompiler and HLSL stub libraries have been
>> fully removed from the build.
>> 
>> This fixes the configuration by detecting if the stub libraries are
>> still present (glslang releases before version 14.0.0).
>> 
>> ffbuild/config.log:
>> /usr/lib/gcc/x86_64-pc-linux-gnu/13/../../../../x86_64-pc-linux-gnu/bin/ld: 
>> cannot find -lOSDependent: No such file or directory
>> /usr/lib/gcc/x86_64-pc-linux-gnu/13/../../../../x86_64-pc-linux-gnu/bin/ld: 
>> cannot find -lHLSL: No such file or directory
>> /usr/lib/gcc/x86_64-pc-linux-gnu/13/../../../../x86_64-pc-linux-gnu/bin/ld: 
>> cannot find -lOGLCompiler: No such file or directory
>> 
>> Addresses https://trac.ffmpeg.org/ticket/10713
>> See https://bugs.gentoo.org/show_bug.cgi?id=918989
>> Should fix 
>> https://ffmpeg.org/pipermail/ffmpeg-devel/2023-August/313666.html
>> 
>> Signed-off-by: Matthew White <mehw.is.me at inventati.org>
>> ---
>>   configure | 23 +++++++++++++++++++++--
>>   1 file changed, 21 insertions(+), 2 deletions(-)
>> 
>> diff --git a/configure b/configure
>> index c8ae0a061d..abff488dc0 100755
>> --- a/configure
>> +++ b/configure
>> @@ -2626,6 +2626,7 @@ CMDLINE_SET="
>>       ignore_tests
>>       install
>>       ld
>> +    libglslang_ldflags
>>       ln_s
>>       logfile
>>       malloc_prefix
>> @@ -6652,6 +6653,24 @@ if enabled_all libglslang libshaderc; then
>>       die "ERROR: libshaderc and libglslang are mutually exclusive, if in 
>> doubt, disable libglslang"
>>   fi
>>   +if enabled libglslang; then
>> +    if [ -x "$(command -v glslang)" ]; then
>> +        # https://github.com/KhronosGroup/glslang
>> +        # commit 6be56e45e574b375d759b89dad35f780bbd4792f: Remove 
>> `OGLCompiler` and `HLSL` stub libraries from build
>> +        # StandAlone/StandAlone.cpp: 
>> "SpirvGeneratorVersion:GLSLANG_VERSION_MAJOR.GLSLANG_VERSION_MINOR.GLSLANG_VERSION_PATCH 
>> GLSLANG_VERSION_FLAVOR"
>> +        glslang_version="$(glslang -dumpversion)"
>> +        glslang_major="${glslang_version%%.*}"
>> +        glslang_major="${glslang_major#*:}"
>> +        if test ${glslang_major} -le 13; then
>> +            libglslang_ldflags=" -lOSDependent -lHLSL -lOGLCompiler"
>> +        elif ! [[ ${glslang_major} =~ ^[0-9]+$ ]]; then
>> +            die "ERROR: glslang's computed major version isn't a number: 
>> '${glslang_major}'"
>> +        fi
>> +    else
>> +        die "ERROR: glslang binary not found, impossible to determine 
>> installed glslang's version"
>> +    fi
>> +fi
>> +
>
> Does that library really not have a sane pkg-config file?
> This kind of guesswork in configure is extremely ugly.

Also, how does this work when cross compiling - won't the "glslang" binary 
be for the foreign cross target? Or is it something like the sdl-config 
script which is a local shell script that can give relevant build flags (a 
design preceding pkg-config)?

// Martin