cmake: Use GnuInstallDirs to customize install directories

Replace custom LIB_INSTALL_DIR with standard CMAKE_INSTALL_LIBDIR variable.
For backward compatibility, set CMAKE_INSTALL_LIBDIR if LIB_INSTALL_DIR is set.

Signed-off-by: Biswapriyo Nath <[email protected]>

3rdparty/everest/CMakeLists.txt

@@ -23,5 +23,5 @@ endif(INSTALL_MBEDTLS_HEADERS)
 
 install(TARGETS everest
   EXPORT MbedTLSTargets
-  DESTINATION ${LIB_INSTALL_DIR}
+  DESTINATION ${CMAKE_INSTALL_LIBDIR}
   PERMISSIONS OWNER_READ OWNER_WRITE GROUP_READ WORLD_READ)

CMakeLists.txt

@@ -39,6 +39,8 @@ else()
     project("mbed TLS" C)
 endif()
 
+include(GNUInstallDirs)
+
 # Determine if mbed TLS is being built as a subproject using add_subdirectory()
 if(NOT DEFINED MBEDTLS_AS_SUBPROJECT)
   set(MBEDTLS_AS_SUBPROJECT ON)
@@ -249,8 +251,7 @@ if(CMAKE_BUILD_TYPE STREQUAL "Coverage")
 endif(CMAKE_BUILD_TYPE STREQUAL "Coverage")
 
 if(LIB_INSTALL_DIR)
-else()
-    set(LIB_INSTALL_DIR lib)
+    set(CMAKE_INSTALL_LIBDIR "${LIB_INSTALL_DIR}")
 endif()
 
 add_subdirectory(include)

ChangeLog.d/cmake_use_GnuInstallDirs.txt

@@ -0,0 +1,5 @@
+Changes
+   * cmake: Use GnuInstallDirs to customize install directories
+     Replace custom LIB_INSTALL_DIR variable with standard CMAKE_INSTALL_LIBDIR
+     variable. For backward compatibility, set CMAKE_INSTALL_LIBDIR if
+     LIB_INSTALL_DIR is set.

library/CMakeLists.txt

@@ -291,7 +291,7 @@ foreach(target IN LISTS target_libraries)
     install(
         TARGETS ${target}
         EXPORT MbedTLSTargets
-        DESTINATION ${LIB_INSTALL_DIR}
+        DESTINATION ${CMAKE_INSTALL_LIBDIR}
         PERMISSIONS OWNER_READ OWNER_WRITE GROUP_READ WORLD_READ)
 endforeach(target)