Re: [Qemu-devel] [PATCH] Fix cross compilation

[Stefan Weil <weil@mail.berlios.de>]

Am 18.05.2010 19:43, schrieb Aurelien Jarno:
> On Sun, Apr 11, 2010 at 06:44:18PM +0200, Stefan Weil wrote:
>    
>> This patch enhances the algorithm which finds the correct settings for SDL.
>> For cross compilations (when cross_prefix is set), it looks for sdl-config
>> with cross prefix. Here is the complete search order:
>>
>> $(cross_prefix}pkg-config              (old, only used for cross compilation)
>> ${cross_prefix}sdl_config              (new, only used for cross compilation)
>> pkg-config                             (old, needs PATH)
>> sdl-config                             (old, needs PATH)
>>
>> Cross SDL packages (or the user) now can simply set a link (for example
>> /usr/bin/i586-mingw32msvc-sdl-config ->  /usr/i586-mingw32msvc/bin/sdl-config)
>> which allows cross compilations without PATH modifications.
>>
>> Without the patch, configure and make (which calls configure) typically
>> need a non-standard PATH. Failing to set this special PATH results in
>> broken builds.
>>
>> v2:
>> * Favour pkg-config over sdl-config for cross compilations
>>    (suggested by Aurelien Jarno) and add comment for this.
>>
>> Cc: Aurelien Jarno<aurelien@aurel32.net>
>> Signed-off-by: Stefan Weil<weil@mail.berlios.de>
>> ---
>>   configure |   12 +++++++++++-
>>   1 files changed, 11 insertions(+), 1 deletions(-)
>>
>> diff --git a/configure b/configure
>> index 966cd7d..47fca4f 100755
>> --- a/configure
>> +++ b/configure
>> @@ -1064,7 +1064,17 @@ fi
>>   ##########################################
>>   # SDL probe
>>
>> -if $pkgconfig sdl --modversion>/dev/null 2>&1; then
>> +# Look for sdl configuration program (pkg-config or sdl-config).
>> +# Prefer variant with cross prefix if cross compiling,
>> +# and favour pkg-config with sdl over sdl-config.
>> +if test -n "$cross_prefix" -a $pkgconfig != pkg-config&&  \
>>      
>                                 ^^^^^^^^^^^^^^^^^^^^^^^^^^
> 			       Why this test ?
>
>    

This tests for cross compilation with a working cross pkg-config
(and not the fallback solution "hope for the best" which is used
in the third case).

>> +     $pkgconfig sdl --modversion>/dev/null 2>&1; then
>> +  sdlconfig="$pkgconfig sdl"
>>      
> It should probably be sdlconfig="${cross_prefix}$pkgconfig sdl" so that
> the cross version of pkg-config is called later in this file.
>    

pkgconfig="${cross_prefix}pkg-config" (was set earlier),
so it is the cross version.


>    
>> +  _sdlversion=`$sdlconfig --modversion 2>/dev/null | sed 's/[^0-9]//g'`
>> +elif test -n "$cross_prefix"&&  has ${cross_prefix}sdl-config; then
>> +  sdlconfig="${cross_prefix}sdl-config"
>> +  _sdlversion=`$sdlconfig --version | sed 's/[^0-9]//g'`
>> +elif $pkgconfig sdl --modversion>/dev/null 2>&1; then
>>     sdlconfig="$pkgconfig sdl"
>>     _sdlversion=`$sdlconfig --modversion 2>/dev/null | sed 's/[^0-9]//g'`
>>   elif has sdl-config; then
>> -- 
>> 1.7.0
>>
>>
>>
>>
>>      
>