[CMake] funny cmake warnings about conflicting library folders

[Markus Blatt]

On Mon, Sep 03, 2012 at 12:54:09AM +0200, Nico Schlömer wrote:
> In an attempt to make Foobar relocatable, the library and header
> directories are specified in
> /usr/share/cmake/Foobar/FoobarConfig.cmake as
> 
> SET(Foobar_INCLUDE_DIRS "${CMAKE_CURRENT_LIST_DIR}/../../../include/foobar")
> SET(Foobar_LIBRARY_DIRS "${CMAKE_CURRENT_LIST_DIR}/../../../lib")
> 
> All of this seems correct.
> When running CMake on a project with FIND_PACKAGE(Foobar), the user is
> swamped with warnings of the kind
> 
> ==================== *snip* ====================
> CMake Warning at test/CMakeLists.txt:81 (ADD_EXECUTABLE):
>   Cannot generate a safe runtime search path for target operatorTest because
>   files in some directories may conflict with libraries in implicit
>   directories:
> 
>     runtime library [libblas.so.3] in /usr/lib may be hidden by files in:
>       /usr/share/cmake/Foobar/../../../lib
> 
>   Some of these libraries may not be found correctly.
> ==================== *snap* ====================
> 
> When I edit /usr/share/cmake/Foobar/FoobarConfig.cmake to read
> 
> SET(Foobar_LIBRARY_DIRS "/usr/lib"),
> 
> those warnings disappear.

I think CMake relies on absolute pathes. You might want to do
something like this :

get_filename_component(_dir "${CMAKE_CURRENT_LIST_FILE}" PATH)
get_filename_component(_prefix "${_dir}/../../.." ABSOLUTE)
 SET(Foobar_INCLUDE_DIRS "${_prefix}/include/foobar")
 SET(Foobar_LIBRARY_DIRS "${_prefix}/lib")


In newer versions there are also some macros/functions in
CMakePackageConfigHelpers that help
producing portable package configuration files.

Cheers,

Markus

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Dr. Markus Blatt - HPC-Simulation-Software & Services http://www.dr-blatt.de
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