[PATCH][Ffmpeg-devel] Compilation Issue

Michel Bardiaux mbardiaux
Mon Oct 3 14:18:06 CEST 2005


Alexander Strasser wrote:
> Hi,
> 
> Michel Bardiaux wrote:
> 
>>Alexander Strasser wrote:
>>
>>> Oh, sorry. Here is an updated patch.
>>
>>Here is what I get for a shared-lib compile on mingw:
> 
> [...]
> 
>>gcc -shared 
>>-Wl,--enable-runtime-pseudo-reloc,--output-def,avutil.def,--out-implib,libavutil.dll.a 
>>-o avutil.dll mathematics.o integ        er.o rational.o 
>>intfloat_readwrite.o  -lm
>>c:\mingw\bin\..\lib\gcc-lib\mingw32\3.2\..\..\..\..\mingw32\bin\ld.exe: 
>>unrecognized option '--enable-runtime-pseudo-reloc'
>>c:\mingw\bin\..\lib\gcc-lib\mingw32\3.2\..\..\..\..\mingw32\bin\ld.exe: 
>>use the --help option for usage information
>>make[1]: *** [avutil.dll] Error 1
>>make[1]: Leaving directory 
>>`/p/people/michel/internet/ffmpeg-mingw-org/libavutil'
>>make: *** [lib] Error 2
>>
>>$ gcc --version
>>gcc.exe (GCC) 3.2 (mingw special 20020817-1)
>>
>>Seems your patch depends on a very recent feature of gcc. What is it 
>>supposed to do?
> 
> 
>   Oh, i didn't know it is such a `new' linker option. OK, then
> i guess there is no way to make it work for every one without
> doing some changes to the code.
> 
> [...]
> 
>>Short version: it all hangs on --enable-runtime-pseudo-reloc. A little 
>>google shows it is strongly recommended for all dll builds using mingw, 
>>so I suppose we'll want to keep it even if not absolutely necessary. So, 
>>what is the minimum version of mingw/gcc/msys I need?
> 
> 
>   I don't know when it was exactly introduced, but i guess somewhen
> at end of 2002 and beginning of 2003 (not sure tho).
>   I am still a little bit confused of the issue as it requires special
> options for GNU ld but works (as it seems) flawlessly with m$ linker.
> What i have read would rather imply the opposite situation if i
> understood correctly.
> 
>   Another question is if we should apply this for now to fix the
> situation for people with recent linker versions as the shared build
> won't work correctly for the current version anyway?

I dont understand at all what you mean. Let me rephrase the questions.

(1) What version of gcc do you use?

(2) Why did you introduce --enable-runtime-pseudo-reloc? What fails if 
that option is not present?

> 
>   Maybe the best fix for all is to use the link directly-to-dll
> feature you demonstrated in your previous mails.

Uh? What do you mean? I dont think VC++ can link to a DLL without a .def 
or a .lib.

>  But it will be
> a bit more involved to implement it properly.
> 
>   Alex (beastd)
> 



-- 
Michel Bardiaux
R&D Director
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