[CMake] Finding libs/headers on MSYS/MinGW

[Kai Sterker]

On 9/26/06, Brandon J. Van Every <bvanevery at gmail.com> wrote:

> > A CMake compiled from MSYS (as opposed to cygwin) seems to be
> > a native Windows App with limited knowledge of stuff like /usr/local.
>
> Data point: I use MinGW / MSYS as my primary build environment.  I use a
> CMake that was compiled with Visual Studio .NET 2003, i.e. standard
> issue CMake 2.4.

I tried versions I build with MSYS/MinGW and VC6 and just now the
official build from the cmake website, but I haven't seen any
difference in their behaviour (as should be expected).


> I do not invoke CMake from a MSYS command line.  I use
> a shortcut and run it from outside MSYS.  It picks up MSYS just fine.  I
> don't have the path problems you mention.

Maybe I should give an example of what works (and what doesn't).
Running cmake from MSYS like so

    Sterker at NTNBKST /d/adonthell/adonthell/build
    $ start cmake -DADONTHELL_DATADIR="." -G "MSYS Makefiles" -i ..

gives:

[snip]
    Variable Name: SDLMIXER_INCLUDE_DIR
    Description: Path to a file.
    Current Value: SDLMIXER_INCLUDE_DIR-NOTFOUND

    Variable Name: SDLMIXER_LIBRARY
    Description: Path to a library.
    Current Value: D:/Programme/msys/local/bin/SDL_mixer.dll

    Variable Name: SDL_INCLUDE_DIR
    Description: Path to a file.
    Current Value: SDL_INCLUDE_DIR-NOTFOUND

    Variable Name: SDL_LIBRARY
    Description: Where the SDL Library can be found
    Current Value: mingw32;D:/Programme/msys/local/bin/SDL.dll
[snip]

The pattern I see here is that cmake can find the DLLs that ended up
in the bin directory, because /usr/local/bin is in my $PATH:

    $ echo $PATH
    .:/usr/local/bin:/mingw/bin:/bin:/d/oracle/ora81/bin: \
    /c/Programme/Oracle/jre/1.1.7/bin:/c/WINNT/system32: \
    /c/WINNT:/c/WINNT/System32/Wbem:/d/TIBCO/TIBRV6.9/BIN: \
    /c/Programme/Gemeinsame Dateien/GTK/2.0/bin: \
    /c/Programme/cvsnt:/d/Programme/apache-ant-1.6.5/bin:/mingw/bin

But cmake cannot find the headers, (or libraries in /usr/local/lib),
because it does know nothing about the UNIX-like structure of MSYS.

So the problem is not that there is something wrong when running cmake
from a MSYS shell instead of a Windows command prompt. It behaves
exactly the same as far as I can tell. The "problem" is that it could
do better in a MSYS development environment than it currently does, by
taking the unixish nature of MSYS into account.


> In the meantime, you might consider using
> CMake "in the standard way" to get around your problems.

Well, I can specify all those libs and headers cmake couldn't figure
out manually, but I had hoped for it to work without user
intervention, just like on a proper UNIX. I know that only developers
will probably ever want to compile my application on Windows
themselves, so it shouldn't matter if the process is a bit rough. But
I thought that this would be an opportunity for improving an otherwise
great tool, so I wanted to let you know. (Being selfish here, I know
;-))

Cheers,

Kai