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

[Roy Tam <roytam@gmail.com>]

Hi,

2011/6/27 TeLeMan <geleman@gmail.com>:
> 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
>

Works for me here.
But for the configure script, I need modifying to pass instead of giving error.

-    vnc_png_libs="-lpng"
+    vnc_png_libs="-lpng -lz"


> --
> SUN OF A BEACH
>
>
>
> On Mon, Jun 27, 2011 at 04:26, Blue Swirl <blauwirbel@gmail.com> wrote:
>> On Sun, Jun 26, 2011 at 11:03 PM, Stefan Weil <weil@mail.berlios.de> wrote:
>>> Am 26.06.2011 20:06, schrieb Blue Swirl:
>>>>
>>>> On Thu, Jun 23, 2011 at 6:05 PM, Stefan Weil<weil@mail.berlios.de>  wrote:
>>>>>
>>>>> Am 23.06.2011 15:52, schrieb Stefan Hajnoczi:
>>>>>>
>>>>>> On Sat, Jun 18, 2011 at 10:35:57AM +0200, Stefan Weil wrote:
>>>>>>>
>>>>>>> Am 18.06.2011 07:13, schrieb Roy Tam:
>>>>>>>>
>>>>>>>> This patch fix conflicting types for 'INT32' in basetsd.h in including
>>>>>>>> qemu-common.h first.
>>>>>>>>
>>>>>>>>
>>>>>>>> Sign-off-by: Roy Tam<roytam@gmail.com>
>>>>>>>> --
>>>
>>> ...
>>>>>>>
>>>>>>> The conflicting declaration is in jmorecfg.h which is included from
>>>>>>> jpeglib.h.
>>>>>>
>>>>>> Is the problem that the Windows headers included from qemu-common.h try
>>>>>> to #define INT32?
>>>>>> http://msdn.microsoft.com/en-us/library/aa383751(v=vs.85).aspx
>>>>>>
>>>>>> In that case I think an explicit fix is better:
>>>>>>
>>>>>> #ifdef _WIN32
>>>>>> /* Include this before jpeglib.h for the INT32 definition */
>>>>>> #include<basetsd.h>
>>>>>> #endif
>>>>>>
>>>>>> ...followed by png/jpeg includes...
>>>>>>
>>>>>> Simply moving qemu-common.h provides no hints and is rather indirect.
>>>>>> Someone may move it back in the future.
>>>>>>
>>>>>> Stefan
>>>>>
>>>>> INT32 is declared in basetsd.h which is included from windows.h
>>>>> (with some indirections) which is included from qemu-os-win32.h
>>>>> which is included from qemu-common.h.
>>>>>
>>>>> INT32 is not a #define, but a data type (typedef) and very common
>>>>> for w32 compilations. Windows programmers don't include basetsd.h
>>>>> directly, but usually use windows.h.
>>>>>
>>>>> Including qemu-common.h right at the beginning (after config.h where
>>>>> needed) should be good practice for QEMU source code - like this:
>>>>>
>>>>> #include "config.h"        /* optional */
>>>>> #include "qemu-common.h"
>>>>> #include <system includes> /* without those that are included from
>>>>> qemu-common.h */
>>>>> ...
>>>>> #include "other local includes"
>>>>> ...
>>>>>
>>>>> As long as the maintainers don't accept patches which simply move
>>>>> qemu-common.h, there is no danger. :-)
>>>>>
>>>>> Of course a comment might be added. In most cases, I'm a great friend
>>>>> of good comments, but in this special case, I don't think it is
>>>>> necessary.
>>>>> It's a very special case of a typedef conflict caused by the mingw32
>>>>> version of jpeglib (which is obviously rarely used), and it might be
>>>>> fixed
>>>>> in a newer version of jpeglib (so the comment would be no longer
>>>>> valid, and nobody would notice that).
>>>>
>>>> We could also add a configure time check for this case for maximum
>>>> over engineering.
>>>
>>> ... which nobody wants. I suggest to apply the patch as it was sent
>>> by Roy. Stefan H. suggests to add a comment before the patch is applied.
>>>
>>> Both ways fix a (small) problem, so please just decide which
>>> solution you prefer.
>>
>> I applied the patch with a comment, thanks.
>>
>>
>