Intel compiler: silence noisy warning for incorrectly evaluated inlining

cmake/CMakeLists.txt

@@ -28,6 +28,14 @@ else()
   set(CMAKE_CXX_EXTENSIONS OFF)
 endif()
 
+# The Intel compiler isn't able to deal with noinline member functions of
+# template classses defined in headers.  As such it spams the output with
+#   warning #2196: routine is both "inline" and "noinline"
+# This silences that warning.
+if (CMAKE_CXX_COMPILER_ID MATCHES Intel)
+  string(APPEND CMAKE_CXX_FLAGS " -diag-disable=2196")
+endif()
+
 # Options
 option(protobuf_BUILD_TESTS "Build tests" ON)
 option(protobuf_BUILD_CONFORMANCE "Build conformance tests" OFF)