Re: [Plplot-general] wingcc drivers fails to build onWindows 7 64bit/VC

[Sisyphus <sis...@op...>]

----- Original Message ----- 
From: "Alan W. Irwin" <ir...@be...>

>> -- The CXX compiler identification is unknown
>> -- Check for working CXX compiler: g++.exe

> Assuming x86_64-w64-mingw32-g++.exe is on your PATH, my guess is the "++" 
> is
> causing problems in the name of the executable.  You may need to quote it
> ('++') or even escape it inside quotes ('\+\+') before cmake can find that
> executable for itself.  There is probably special code within CMake to
> find g++.exe (with no prefix) without further help, but that is probably
> not true of x86_64-w64-mingw32-g++.exe.

Haven't yet found a rendition that works. I've even created a copy of the 
g++ executable called 'cpp.exe' and tried to use it. I've tried altering 
CMAKE_CXX_COMPILER and CMAKE_CXX_COMPILER:FILEPATH, but it's always the same 
error (as above). I think the failure to access cpp.exe indicates that 
there's more to the problem than just the '+' symbols.
It's as though there's a decision made somewhere in the sources that the g++ 
executable has to be named 'g++.exe' and nothing else is acceptable.

>> Haven't yet worked out how I'm supposed to tell the process that 'ar.exe' 
>> is
>> really named 'x86_64-w64-mingw32-ar.exe' . Anyone know ?
>
> What do you get for CMAKE_AR:FILEPATH in your CMakeCache.txt file?  If 
> that
> is not the correct value, I think you should be able to override it with
> -DCMAKE_AR:FILEPATH=\whatever\path\to\ar\x86_64-w64-mingw32-ar.exe
>

Yes, that works nicely. Thanks.

> Of course, the proper way to set platform-dependent constants is with a 
> new
> or modified file in (e.g., $prefix/share/cmake-2.8/Modules/Platform/.
> However, platform files are sometimes a difficult topic, so I would report
> what constants you need to set with -D to the CMake developers at the
> cm...@cm... mailing list with an exact description of your platform so
> they can figure out what platform file changes need to be done to
> make the experience for the next user of your platform much smoother.

Most people who build with MinGW64 use the "sezero" version of the compiler 
where the various executables (gcc, g++, ar, etc.) are given their usual 
names. The only problems they will come up against are the wingcc.c code 
(already fixed in svn) and the absence of a correct library path in the 
MINGWLIBPATH list in CMakeLists.txt. Once that has been taken care of, 
they're right to go without any need for changes to platform files.

As regards the extra requirements that need to be met when the 
cross-compiler is being used, I'll consider raising it with the developers 
as you suggest - though I'm not sure that setting up new platform files just 
to accommodate the mingw64 cross-compiler is really worth the effort (given 
that very few seem to use that particular compiler, and those that do 
probably accept that they need to take some extra steps themselves). A 
,mention on how to build with the cross-compiler on the wiki might be handy, 
however.

Anyway, I'd like to first work out why I can't get the build process to use 
x86_64-w64-mingw32-g++.exe.

Thanks muchly for the pointers.

Cheers,
Rob