Re: [hatari-devel] cmake and cross-compiling

[Nicolas Pomarède <npomarede@xxxxxxxxxxxx>]

On 27/12/2012 11:09, Christer Solskogen wrote:
> Toolchain-mingw32.cmake uses CMAKE_FIND_ROOT_PATH in order to find its sysroot.
> I really don't see why that is necessary since a proper cross compiler
> will already have that set (using --with-sysroot= during build) - is
> CMAKE_FIND_ROOT_PATH something that cmake really needs to cross
> compile?

Hello

it's not the compiler that cmake doesn't find, it's the mingw version of 
sdl, zlib, libpng and other libraries.

With CMAKE_FIND_ROOT_PATH :

-- Found SDL: 
mingw32;/usr/i586-pc-mingw32/sys-root/mingw/lib/libSDLmain.a;/usr/i586-pc-mingw32/sys-root/mingw/bin/SDL.dll 

-- Found MATH: /usr/i586-pc-mingw32/sys-root/mingw/lib/libm.a
-- Found READLINE: /usr/i586-pc-mingw32/sys-root/mingw/bin/readline.dll
-- Found ZLIB: /usr/i586-pc-mingw32/sys-root/mingw/lib/libz.dll.a (found 
version "1.2.3")
-- Found PNG: /usr/i586-pc-mingw32/sys-root/mingw/lib/libpng.dll.a 
(found version "1.2.35")


Without CMAKE_FIND_ROOT_PATH :

-- Found SDL: mingw32;/usr/lib/libSDLmain.a;/usr/lib/libSDL.a
-- Could NOT find MATH (missing:  MATH_LIBRARY)
-- Could NOT find READLINE (missing:  READLINE_LIBRARY)
-- Found ZLIB: /usr/lib/libz.a (found version "1.2.7")
-- Could NOT find PNG (missing:  PNG_LIBRARY) (found version "1.5.13")


As you can see, the mingw versions of the libs are not found (or cmake 
will use the host system ones, which is not good)
Maybe different linux distrib / cmake will give good results without 
CMAKE_FIND_ROOT_PATH, but as it needed at least in this example, the 
line is needed.

It seems cmake has some proper rules to find c/c++ compiler and linker, 
but more "exotic" libs don't provide a definition file for cmake.

In your case, if you comment CMAKE_FIND_ROOT_PATH, does ./configure find 
the mingw libs ?

Nicolas