Merge topic 'EclipseDetectClangIncludeDirs'

a396b6e Eclipse: also detect include dirs and macro for clang (#13823)

Modules/CMakeExtraGeneratorDetermineCompilerMacrosAndIncludeDirs.cmake

@@ -90,7 +90,7 @@ set(ENV{LANG}        C)
 
 # Now check for C, works for gcc and Intel compiler at least
 if (NOT CMAKE_EXTRA_GENERATOR_C_SYSTEM_INCLUDE_DIRS)
-  if ("${CMAKE_C_COMPILER_ID}" MATCHES GNU  OR  "${CMAKE_C_COMPILER_ID}" MATCHES Intel)
+  if ("${CMAKE_C_COMPILER_ID}" MATCHES GNU  OR  "${CMAKE_C_COMPILER_ID}" MATCHES Intel  OR  "${CMAKE_C_COMPILER_ID}" MATCHES Clang)
     _DETERMINE_GCC_SYSTEM_INCLUDE_DIRS(c _dirs _defines)
     set(CMAKE_EXTRA_GENERATOR_C_SYSTEM_INCLUDE_DIRS "${_dirs}" CACHE INTERNAL "C compiler system include directories")
     set(CMAKE_EXTRA_GENERATOR_C_SYSTEM_DEFINED_MACROS "${_defines}" CACHE INTERNAL "C compiler system defined macros")
@@ -99,7 +99,7 @@ endif ()
 
 # And now the same for C++
 if (NOT CMAKE_EXTRA_GENERATOR_CXX_SYSTEM_INCLUDE_DIRS)
-  if ("${CMAKE_CXX_COMPILER_ID}" MATCHES GNU  OR  "${CMAKE_CXX_COMPILER_ID}" MATCHES Intel)
+  if ("${CMAKE_CXX_COMPILER_ID}" MATCHES GNU  OR  "${CMAKE_CXX_COMPILER_ID}" MATCHES Intel  OR  "${CMAKE_CXX_COMPILER_ID}" MATCHES Clang)
     _DETERMINE_GCC_SYSTEM_INCLUDE_DIRS(c++ _dirs _defines)
     set(CMAKE_EXTRA_GENERATOR_CXX_SYSTEM_INCLUDE_DIRS "${_dirs}" CACHE INTERNAL "CXX compiler system include directories")
     set(CMAKE_EXTRA_GENERATOR_CXX_SYSTEM_DEFINED_MACROS "${_defines}" CACHE INTERNAL "CXX compiler system defined macros")