Re: [Qemu-devel] [PATCH] configure: Support pkg-config for zlib

[Stefan Weil]

Am 18.07.2018 um 18:21 schrieb Daniel P. Berrangé:
> On Thu, Jul 12, 2018 at 09:26:03PM +0200, Stefan Weil wrote:
>> This is needed for builds with the mingw64-* packages from Cygwin,
>> but also works for Linux.
>>
>> Move the zlib test also more to the end because users should
>> get information on the really important missing packages
>> (which also require zlib) first.
> 
> According to the zlib Changelog file pkgconfig support was added
> in 2006 !
> 
> [quote]
> Changes in 1.2.3.1 (16 August 2006)
> 
>   - Add pkgconfig support [Weigelt]
> [/quote]
> 
> Given our target build platforms support guidelines
> 
>   https://qemu.weilnetz.de/doc/qemu-doc.html#Supported-build-platforms
> 
> we can safely say that all supported platforms will have a zlib
> that contains pkgconfig support, so......
> 
>>
>> Signed-off-by: Stefan Weil <address@hidden>
>> ---
>>  configure | 40 +++++++++++++++++++++++-----------------
>>  1 file changed, 23 insertions(+), 17 deletions(-)
>>
>> diff --git a/configure b/configure
>> index 2a7796ea80..dcaab01729 100755
>> --- a/configure
>> +++ b/configure
>> @@ -2140,23 +2140,6 @@ EOF
>>    fi
>>  fi
>>  
>> -#########################################
>> -# zlib check
>> -
>> -if test "$zlib" != "no" ; then
>> -    cat > $TMPC << EOF
>> -#include <zlib.h>
>> -int main(void) { zlibVersion(); return 0; }
>> -EOF
>> -    if compile_prog "" "-lz" ; then
>> -        :
>> -    else
>> -        error_exit "zlib check failed" \
>> -            "Make sure to have the zlib libs and headers installed."
>> -    fi
>> -fi
>> -LIBS="$LIBS -lz"
>> -
>>  ##########################################
>>  # lzo check
>>  
>> @@ -3525,6 +3508,29 @@ if ! compile_prog "$glib_cflags -Werror" "$glib_libs" 
>> ; then
>>      fi
>>  fi
>>  
>> +#########################################
>> +# zlib check
>> +
>> +if test "$zlib" != "no" ; then
>> +    if $pkg_config --exists zlib; then
>> +        zlib_cflags=$($pkg_config --cflags zlib)
>> +        zlib_libs=$($pkg_config --libs zlib)
>> +        QEMU_CFLAGS="$zlib_cflags $QEMU_CFLAGS"
>> +        LIBS="$zlib_libs $LIBS"
>> +    else
>> +        cat > $TMPC << EOF
>> +#include <zlib.h>
>> +int main(void) { zlibVersion(); return 0; }
>> +EOF
>> +        if compile_prog "" "-lz" ; then
>> +            LIBS="$LIBS -lz"
>> +        else
>> +            error_exit "zlib check failed" \
>> +                "Make sure to have the zlib libs and headers installed."
>> +        fi
>> +    fi
> 
> .... this fallback support for non-pkgconfig scenarios can be entirely
> deleted, just leaving the error_exit message. 
> 
> 
> Regards,
> Daniel

I have no objection. Thank you for the investigation of the zlib
history. Removing old unneeded code is always good, but maybe that's
something which could be done after release 3.0.

Or would you suggest to do it now? Then I can either send an updated
patch (v2), or whoever pulls that patch can make that trivial modification.

Cheers
Stefan