[Log4cpp-devel] Porting log4cpp to QNX Neutrino 6.1

[Harald W. <Har...@gm...>]

Hello again,

the short story is: log4cpp is running on QNX 6.1 without significant 
changes, and it passes all tests.

The long story: you may actually be wondering what the heck QNX is, and 
I do admit I had never heard of it until last year... It's a real-time 
embedded operating system, and a major player in that somewhat 
fragmented market. More details on www.qnx.com.

QNX does have some specialities, but it is more or less POSIX compatible 
and uses the gcc compiler suite, so you wouldn't expect any real trouble 
compiling any GNU compatible configure-make-install package.

The biggest issue is the fact that although they use gcc, it doesn't 
come with the GNU libstdc++ but with the Dinkumware libraries instead. I 
can't tell which of these two "Standard" C++ Library implementations is 
closer to the ISO C++ standard, but the fact is that most of the free 
stuff you get is developed on GNU, and most of it (going by the dozen or 
so packages I've tried) fails to compile against the Dinkum libs. To be 
fair, most of the errors are std:: namespace issues, and those are 
fairly easy to fix.

Now here's a summary of the changes I had to make:

- With the -pedantic compiler option, gcc gets so pedantic it refuses to 
compile anything at all, so I turned it off.

- Optimization -O2 produces internal compiler errors on some sources, so 
I removed that as well.

- gcc by default simply ignores the std:: namespace (at least in 
versions <= 2.95.3; I don't know about the most recent versions), but 
not in the QNX variant with the Dinkum libs. In most files, I had to 
insert "using namespace std;" or prefix a few function calls with std::.

- A similar problem is the syntax of standard C header includes. On QNX, 
you have to write #include <cstdio> instead of #include <stdio.h>, or 
you will get lots of symbol redefinition errors.

- The int64 stuff in PatternLayout doesn't compile, not even with the 
workaround, so I disabled it. Maybe there's a solution, I haven't looked 
at it closely.

- Some of the global Makefile settings are different, of course. The 
compiler and linker is called QCC, and you don't link any external 
libraries. pthread_* stuff is available by default.

- libtool refused to produce libraries. I installed a newer libtool 
version and I got archived libraries, but I haven't found out how to 
produce shared libs yet.


That's it, more or less. No big issues. I can post a patch for someone 
to review the changes, and if the community decides to accept them into 
the standard distribution, the final step (and for me, the most 
difficult one) would be to set up all the autoconf and automake input.
So far, I've simply edited the generated Makefiles, which is not the 
proper way, I know, but I have very limited experience with the auto* 
tools, and I find them rather hairy....

Any feedback is welcome!

Regards,
Harald