Re: [Qemu-devel] [Qemu-trivial] [PATCH] fix MinGW compilation when --enable-vnc-jpeg is specified

[Paolo Bonzini <pbonzini@redhat.com>]

On 06/27/2011 07:22 PM, Stefan Weil wrote:
> Am 27.06.2011 07:56, schrieb Roy Tam:
>> 2011/6/27 Stefan Weil<weil@mail.berlios.de>:
>>> Am 27.06.2011 04:37, schrieb TeLeMan:
>>>> This patch breaks the compilation with --enable-vnc-png:
>>>>
>>>> CC ui/vnc-enc-tight.o
>>>> In file included from /usr/include/png.h:518,
>>>> from ui/vnc-enc-tight.c:34:
>>>> /usr/include/pngconf.h:371: error: expected '=', ',', ';', 'asm' or
>>>> '__attribute__' before '.' token
>>>> /usr/include/pngconf.h:372: error: expected '=', ',', ';', 'asm' or
>>>> '__attribute__' before 'include'
>>>> make: *** [ui/vnc-enc-tight.o] Error 1
>>>>
>>>> -- 
>>>> SUN OF A BEACH
>>> I get the same compiler error when I run with --enable-vnc-png,
>>> and the buildbots got it as well. In my last test, png support
>>> was disabled, so I did not notice this problem.
>>>
>>> The png header files check for prior inclusion of setjmp.h
>>> and have a really surprising way of telling that this happened
>>> (instead of #error, they use illegal C code - a comment without
>>> comment delimiters).
>>>
>> I wonder which libpng version do you use. Mine is 1.5.2 and it works 
>> here.
> 
> The critical code is only active for linux (#ifdef __linux__ ... #endif).
> I was using linbpng-1.2.42 (ubuntu) and libpng-1.2.44 (debian).
> 
> You won't get the problem when compiling with MinGW.

>From pngconf.h

 * You can bypass this test if you know that your application uses exactly
 * the same setjmp.h that was included when libpng was built.  Only define
 * PNG_SKIP_SETJMP_CHECK while building your application, prior to the
 * application's '#include "png.h"'. Don't define PNG_SKIP_SETJMP_CHECK
 * while building a separate libpng library for general use.

Paolo