use INSTALL_LIBDIR to find the actual OpenCL loader (#348)

On some distributions (e.g. Fedora) `/usr/lib` is used for 32 bit libs.

Instead of searching in hardcoded `/usr/lib/` and `/usr/local/lib` we
should make use of CMAKE_INSTALL_LIBDIR as this will most like contain the
correct value for the targeted system.

Author: karolherbst

intercept/CMakeLists.txt

@@ -273,5 +273,6 @@ if(WIN32)
     endforeach( OUTPUTCONFIG CMAKE_CONFIGURATION_TYPES )
 elseif(UNIX)
     include(GNUInstallDirs)
+    target_compile_definitions(OpenCL PRIVATE CLINTERCEPT_LIBRARY_DIR="${CMAKE_INSTALL_LIBDIR}")
     install(TARGETS OpenCL DESTINATION ${CMAKE_INSTALL_LIBDIR})
 endif()

intercept/src/intercept.cpp

@@ -557,6 +557,12 @@ bool CLIntercept::init()
 #ifdef CLINTERCEPT_LIBRARY_ARCHITECTURE
             "/usr/lib/" CLINTERCEPT_LIBRARY_ARCHITECTURE "/libOpenCL.so.1",
             "/usr/lib/" CLINTERCEPT_LIBRARY_ARCHITECTURE "/libOpenCL.so",
+#endif
+#ifdef CLINTERCEPT_LIBRARY_DIR
+            "/usr/" CLINTERCEPT_LIBRARY_DIR "/libOpenCL.so.1",
+            "/usr/" CLINTERCEPT_LIBRARY_DIR "/libOpenCL.so",
+            "/usr/local/" CLINTERCEPT_LIBRARY_DIR "/libOpenCL.so.1",
+            "/usr/local/" CLINTERCEPT_LIBRARY_DIR "/libOpenCL.so",
 #endif
             "/usr/lib/libOpenCL.so.1",
             "/usr/lib/libOpenCL.so",