CMake で pkg-config を使う ref: http://qiita.com/janus_wel/items/e70695670c22a0331451

CMakeLists.txt

# load the module to use pkg-config
find_package(PkgConfig)

# search library with pkg-config and name its results "LIBSAMPLE"
pkg_check_modules(LIBSAMPLE REQUIRED libsample)

# use the variable <RESULTNAME>_INCLUDE_DIRS to get include paths
include_directories(${LIBSAMPLE_INCLUDE_DIRS})

add_executable(sample
    main.cpp
    )

# use the variable <RESULTNAME>_LIBRARIES to get library paths
target_link_libraries(sample
    ${LIBSAMPLE_LIBRARIES}
    )