Provide pkg-config file

This allows to use the pkg-config mechanism on supported systems.

cpp/CMakeLists.txt

@@ -712,6 +712,15 @@ configure_package_config_file("cmake/config.cmake.in" "${project_config}" INSTAL
 install(FILES "${project_config}" "${version_config}" DESTINATION "${config_install_dir}")
 install(EXPORT "${targets_export_name}" NAMESPACE ${PROJECT_NAME}:: DESTINATION "${config_install_dir}")
 
+#----------------------------------------------------------------
+# Build and install pkg-config file
+#----------------------------------------------------------------
+if (BUILD_SHARED_LIBS AND UNIX)
+  configure_file(libphonenumber.pc.in libphonenumber.pc @ONLY)
+  install(FILES "${CMAKE_CURRENT_BINARY_DIR}/libphonenumber.pc"
+          DESTINATION "${CMAKE_INSTALL_LIBDIR}/pkgconfig")
+endif ()
+
 #----------------------------------------------------------------
 # Build an RPM
 #----------------------------------------------------------------

cpp/libphonenumber.pc.in

@@ -0,0 +1,10 @@
+prefix=@CMAKE_INSTALL_PREFIX@
+exec_prefix=${prefix}
+libdir=${prefix}/@CMAKE_INSTALL_LIBDIR@
+includedir=${prefix}/@CMAKE_INSTALL_INCLUDEDIR@
+
+Name: libphonenumber
+Description: Parse, format, store and validate international phone numbers
+URL: https://github.com/google/libphonenumber
+Version: @CMAKE_PROJECT_VERSION@
+Libs: -L${libdir} -lphonenumber