[FFmpeg-devel] Question on libbrokenos support

Luca Abeni lucabe72
Mon Feb 4 12:01:15 CET 2008


Hi all,

first of all, sorry for the long delay

Michael Niedermayer wrote:
> On Wed, Jan 09, 2008 at 11:48:32AM +0100, Luca Abeni wrote:
[...]
>> Here, I just want to clarify that my proposal about #include_next did not imply
>> to install libos headers in standard paths: a user would have needed to specify
>> "-I <libos install path>/..." to include such headers, so I think my proposal
>> did not break the whole system.
> 
> hmm
> theres also the option of using
> gcc -include os_support.h

I tried this solution, but it unfortunately has problems: in this way,
os_support.h is included in all files, and it has to include some
system-dependent headers (for example, winsock2.h and ws2tcpip.h for
win32 targets) which sometime define symbols and names used by
os-independent files in libavcodec.
If I remember well, windows headers end up with a "#define near",
which break the compilation of some unrelated files (the jpeg encoder,
I think).
So, I believe that forcing the inclusion of an "os_support.h" in all the
files is not a good solution.

On the other hand, it seems to me that our configure script is already
using the "-E" gcc's option. So, such option can be used to find the
location of the system headers, and to copy them in lbos as suggested by
Michael. (it was objected that this solution is not portable, but if
ffmpeg's configure script is already using it I think it can be used by
lbos too, right?).

I have an almost-working version of lbos that uses "gcc -E" to find the
system headers, (avoiding the need for "#include_next"); I'll post it
after lunch.


				Luca




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