[CMake] How to install headers in a library

[Hendrik Sattler]

Am Sonntag 28 Februar 2010 10:31:57 schrieb Giampiero Gabbiani:
> Hi all,
> I like very much the simplicity of cmake in comparison with the classic
> autotools framework, but still I have two questions concerning the porting
>  of a Linux based project under cmake:
> 
> 1) when defining a library (shared or static) as a project target , I
>  expected that cmake would understand the architecture of the host machine
>  and install conseguently the libraries (.so or .a) in the correct /lib or
>  /lib64 path. Instead I noticed that I have to explicity set the
>  destination path
> 
> install(TARGETS <static library name> ARCHIVE DESTINATION lib64)
> install(TARGETS <shared object name> LIBRARY DESTINATION lib64)
> 
> This works well on my machine (a 64 bit system) but of course will not work
>  if anyone want to install on a 32 bit system.
> 
> So ... is there a way in order to let cmake automatically install on the
> correct path according with the hosting system architecture?
> 
> 2) together with the resulting binaries libs (both archive and library) I
>  want to install also the corrisponding header(s) in /usr/local/include
>  path...how is it possible to do that?

You could use a variable to represent the directory. This would depend on the 
existence of lib64/ (not all have this as directory, on Debian it's just a 
compatibility link to lib/) and on SIZEOF_VOID_P being 8:
set (LIBRARY_INSTALL_DIR lib)
if (EXISTS "${CMAKE_INSTALL_PREFIX}/lib32/" AND CMAKE_SIZEOF_VOID_P EQUAL 4)
  set (LIBRARY_INSTALL_DIR lib32)
elif (EXISTS "${CMAKE_INSTALL_PREFIX}/lib64/" AND CMAKE_SIZEOF_VOID_P EQUAL 8)
  set (LIBRARY_INSTALL_DIR lib64)
endif ()

Or let the user set it.

HS