Added LIB_INSTALL_DIR to correct libs install on 64-bit systems

[Vascom]

Solve for #633

[xor-gate]

This looks good, but it should autodetect lib and lib64. We probably need to implement the solution which is on the cmake mailinglist here: https://cmake.org/pipermail/cmake/2013-July/055374.html

[Vascom]

This not should autodetect lib and lib64. It set by external parameter:
cmake .. -DLIB_INSTALL_DIR:PATH=/usr/lib64

[xor-gate]

That is not true autodetection, that is passed by the developer which builds the package. CMake should be able to autodetect it if the default libdir is lib64. I'm not against adding build parameters but the idea would be good by default.

[Vascom]

Fedora has /usr/lib and /usr/lib64 simultaneously and you can't autodetect where I want place builded libs. Let maintainer do it via -DLIB_INSTALL_DIR:PATH= .

[xor-gate]

Yeah the lib contains 32 bit stuff which can run with the 32bit compatibility layer under
64 bit kernels. But the default detected path should be lib64 because the system booted an amd64 or arm64 kernel anyway.

[Vascom]

You can add autodetect if you wish but keep force redefinition of it by this parameter.

[xor-gate]

Yes that would be fine, but please document the addition of this supported build parameter in doc/compiling.doc

[Vascom]

This is enough?

[xor-gate]

Great, thanks for this. The name LIB_INSTALL_DIR comes from autoconf GNU projects, but I can live with this as it is convenient for everybody.

[Vascom]

Thanks.
I don't know where it from but it used in %cmake macro for building Fedora packages:

  /usr/bin/cmake \
        -DCMAKE_C_FLAGS_RELEASE:STRING="-DNDEBUG" \
        -DCMAKE_CXX_FLAGS_RELEASE:STRING="-DNDEBUG" \
        -DCMAKE_Fortran_FLAGS_RELEASE:STRING="-DNDEBUG" \
        -DCMAKE_VERBOSE_MAKEFILE:BOOL=ON \
        -DCMAKE_INSTALL_PREFIX:PATH=/usr \
        -DINCLUDE_INSTALL_DIR:PATH=/usr/include \
        -DLIB_INSTALL_DIR:PATH=/usr/lib64 \
        -DSYSCONF_INSTALL_DIR:PATH=/etc \
        -DSHARE_INSTALL_PREFIX:PATH=/usr/share \
%if "lib64" == "lib64" 
        -DLIB_SUFFIX=64 \
%endif 
        -DBUILD_SHARED_LIBS:BOOL=ON

[xor-gate]

It also adds the -DLIB_SUFFIX=64 build parameter which seems it uses the solution from the CMake mailing list. The LIB_SUFFIX is probably not supported currently in stlink. I think still we need to implement the solution from the mailing list as I see the fedora specfile to build the RPM as it uses the "lib64" conditional and no /usr/lib64 is hardcoded.

[Vascom]

But -DLIB_SUFFIX is the same external parameter as -DLIB_INSTALL_DIR.