Hi Emad, On Fri, Jul 12, 2013 at 5:17 AM, Emad Gad wrote: (snip) > And that led me to conclude that the i686-w64-mingw32-g++ is the way to go (snip)
> The troubles I am having now is how to build the cmake-based project with > i686-w64-mingw32-g++ compiler, through the cygwin shell? Somehow, I feel > that this may be a contradiction in terms, but let me first report my > observations. > > The main issue here is that the cmake that comes with cygwin will not accept > the compiler i686-w64-mingw32-g++. It will complain that that compiler > "cannot compile a simple file" which is a lie, because I know that it does. > I actually tested, and Matlab used successfully. So how come cmake found out > that it fails to compile? > > I found out the reason by invoking cmake with the option --debug-trycompile, > and there I saw what cmake is trying to do and how it failed. > > cmake tests the compiler by requesting it to compile a very small file, > called textCCompile.c, that it creates on the fly. However, its uses the > absolute path of this file. To be more precise, here is the literal command > that the /cygwinish/ cmake issues > > /cygdrive/c/MinGW64/mingw64/i686-w64-mingw32-g++ -o > cmTryxxxxxxxx/testCCompile.c.o -c > /home/usrername/path/to/the/file/build/CMakeFiles/CMakeTmp/testCCompile.c. > > The main problem here is that i686-w64-mingw32-g++ will not take the > absolute path of the C file /home/usrername/path/to/the/file/testCCompile.c. > Instead, it returns a "file not found" kind of error. The problem is that /cygdrive/c/MinGW64/mingw64/i686-w64-mingw32-g++ is not a Cygwin program, so it interprets /home/usrername/path/to/the/file/testCCompile.c differently from Cygwin's cmake : as a path on the current drive, starting with a directory named "home". However, Cygwin's /home is Windows' C:\cygwin\home Cygwin contains a utility called "cygpath" which can convert between POSIX paths and Windows paths: $ cygpath -w /home/usrername/path/to/the/file/testCCompile.c C:\cygwin\home\usrername\path\to\the\file\testCCompile.c Unfortunately, I don't think you can force cmake to pass all paths through it. > So I feel now that the main problem is that mingw compiler, which worked > with Matlab, the i686-w64-mingw32-g++, does not like UNIX-style absolute > paths, and will not be able to grab any file specified using this mode. > > So my question is am I in the right place? Is it normal to use a > cygwin-based cmake to compile a project with i686-w64-mingw32-g++? It may be possible to force cmake to accept the compiler you specify without checking, e.g. in the environment, like this: CXX=/cygdrive/c/MinGW64/mingw64/i686-w64-mingw32-g++ cmake --trust-the-compiler --the-compiler-is-your-friend path/to/sources But it's likely that the makefiles it generates would also use POSIX paths, and i686-w64-mingw32-g++ will not understand them unless you hack the makefiles to use cygpath to translate filenames before make passes them to i686-w64-mingw32-g++ I suspect it would be easier to use the native Windows version of cmake with the mingw compiler. Csaba -- GCS a+ e++ d- C++ ULS$ L+$ !E- W++ P+++$ w++$ tv+ b++ DI D++ 5++ The Tao of math: The numbers you can count are not the real numbers. Life is complex, with real and imaginary parts. "Ok, it boots. Which means it must be bug-free and perfect. " -- Linus Torvalds "People disagree with me. I just ignore them." -- Linus Torvalds -- Problem reports: http://cygwin.com/problems.html FAQ: http://cygwin.com/faq/ Documentation: http://cygwin.com/docs.html Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple
