Use GNUInstallDirs for install destinations

This has the advantage that the user may override e.g. the include
location, and the correct libdir (lib, lib64, lib/something) is
automatically determined.

Closes #1367.

CMakeLists.txt

@@ -14,7 +14,6 @@ set(GLFW_VERSION_PATCH "0")
 set(GLFW_VERSION_EXTRA "")
 set(GLFW_VERSION "${GLFW_VERSION_MAJOR}.${GLFW_VERSION_MINOR}")
 set(GLFW_VERSION_FULL "${GLFW_VERSION}.${GLFW_VERSION_PATCH}${GLFW_VERSION_EXTRA}")
-set(LIB_SUFFIX "" CACHE STRING "Takes an empty string or 64. Directory where lib will be installed: lib or lib64")
 
 set_property(GLOBAL PROPERTY USE_FOLDERS ON)
 
@@ -25,6 +24,8 @@ option(GLFW_BUILD_DOCS "Build the GLFW documentation" ON)
 option(GLFW_INSTALL "Generate installation target" ON)
 option(GLFW_VULKAN_STATIC "Use the Vulkan loader statically linked into application" OFF)
 
+include(GNUInstallDirs)
+
 if (UNIX)
     option(GLFW_USE_OSMESA "Use OSMesa for offscreen context creation" OFF)
 endif()
@@ -320,7 +321,7 @@ endforeach()
 #--------------------------------------------------------------------
 include(CMakePackageConfigHelpers)
 
-set(GLFW_CONFIG_PATH "lib${LIB_SUFFIX}/cmake/glfw3")
+set(GLFW_CONFIG_PATH "${CMAKE_INSTALL_LIBDIR}/cmake/glfw3")
 
 configure_package_config_file(src/glfw3Config.cmake.in
                               src/glfw3Config.cmake
@@ -357,7 +358,7 @@ endif()
 # The library is installed by src/CMakeLists.txt
 #--------------------------------------------------------------------
 if (GLFW_INSTALL)
-    install(DIRECTORY include/GLFW DESTINATION include
+    install(DIRECTORY include/GLFW DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
             FILES_MATCHING PATTERN glfw3.h PATTERN glfw3native.h)
 
     install(FILES "${GLFW_BINARY_DIR}/src/glfw3Config.cmake"
@@ -368,7 +369,7 @@ if (GLFW_INSTALL)
             EXPORT_LINK_INTERFACE_LIBRARIES
             DESTINATION "${GLFW_CONFIG_PATH}")
     install(FILES "${GLFW_BINARY_DIR}/src/glfw3.pc"
-            DESTINATION "lib${LIB_SUFFIX}/pkgconfig")
+            DESTINATION "${CMAKE_INSTALL_LIBDIR}/pkgconfig")
 
     # Only generate this target if no higher-level project already has
     if (NOT TARGET uninstall)

docs/compile.dox

@@ -210,11 +210,6 @@ cmake -DBUILD_SHARED_LIBS=ON .
 __BUILD_SHARED_LIBS__ determines whether GLFW is built as a static
 library or as a DLL / shared library / dynamic library.
 
-@anchor LIB_SUFFIX
-__LIB_SUFFIX__ affects where the GLFW shared /dynamic library is installed.  If
-it is empty, it is installed to `${CMAKE_INSTALL_PREFIX}/lib`.  If it is set to
-`64`, it is installed to `${CMAKE_INSTALL_PREFIX}/lib64`.
-
 @anchor GLFW_BUILD_EXAMPLES
 __GLFW_BUILD_EXAMPLES__ determines whether the GLFW examples are built
 along with the library.

src/CMakeLists.txt

@@ -100,7 +100,7 @@ set_target_properties(glfw PROPERTIES
 target_compile_definitions(glfw PRIVATE _GLFW_USE_CONFIG_H)
 target_include_directories(glfw PUBLIC
                            "$<BUILD_INTERFACE:${GLFW_SOURCE_DIR}/include>"
-                           "$<INSTALL_INTERFACE:$<INSTALL_PREFIX>/include>")
+                           "$<INSTALL_INTERFACE:${CMAKE_INSTALL_FULL_INCLUDEDIR}>")
 target_include_directories(glfw PRIVATE
                            "${GLFW_SOURCE_DIR}/src"
                            "${GLFW_BINARY_DIR}/src"
@@ -121,7 +121,7 @@ target_compile_options(glfw PRIVATE
 if (BUILD_SHARED_LIBS)
     if (WIN32)
         if (MINGW)
-            # Remove the lib prefix on the DLL (but not the import library
+            # Remove the lib prefix on the DLL (but not the import library)
             set_target_properties(glfw PROPERTIES PREFIX "")
 
             # Add a suffix to the import library to avoid naming conflicts
@@ -135,7 +135,7 @@ if (BUILD_SHARED_LIBS)
         target_compile_options(glfw PRIVATE "-fno-common")
 
         set_target_properties(glfw PROPERTIES
-                              INSTALL_NAME_DIR "lib${LIB_SUFFIX}")
+                              INSTALL_NAME_DIR "${CMAKE_INSTALL_LIBDIR}")
     elseif (UNIX)
         # Hide symbols not explicitly tagged for export from the shared library
         target_compile_options(glfw PRIVATE "-fvisibility=hidden")
@@ -155,7 +155,7 @@ if (GLFW_INSTALL)
     install(TARGETS glfw
             EXPORT glfwTargets
             RUNTIME DESTINATION "bin"
-            ARCHIVE DESTINATION "lib${LIB_SUFFIX}"
+            ARCHIVE DESTINATION "${CMAKE_INSTALL_LIBDIR}"
-            LIBRARY DESTINATION "lib${LIB_SUFFIX}")
+            LIBRARY DESTINATION "${CMAKE_INSTALL_LIBDIR}")
 endif()
 

src/glfw3.pc.in

@@ -1,7 +1,7 @@
 prefix=@CMAKE_INSTALL_PREFIX@
 exec_prefix=${prefix}
-includedir=${prefix}/include
+includedir=@CMAKE_INSTALL_FULL_INCLUDEDIR@
-libdir=${exec_prefix}/lib@LIB_SUFFIX@
+libdir=@CMAKE_INSTALL_FULL_LIBDIR@
 
 Name: GLFW
 Description: A multi-platform library for OpenGL, window and input