Added CMake macro REMOVE_STRICT_FLAGS(), this means developers can build with -Werror in their CMAKE_C_FLAGS_DEBUG (so all warnings give errors).

but external libs which we don't maintain & generated code will have -Werror removed.

This is GCC only, MSVC can be added easily.

build_files/cmake/macros.cmake

@@ -238,6 +238,41 @@ MACRO(TEST_SSE_SUPPORT)
 
 ENDMACRO(TEST_SSE_SUPPORT)
 
+# when we have warnings as errors applied globally this
+# needs to be removed for some external libs which we dont maintain.
+
+# utility macro
+MACRO(_REMOVE_STRICT_FLAGS
+	flag)
+	
+	STRING(REGEX REPLACE ${flag} "" CMAKE_C_FLAGS ${CMAKE_C_FLAGS})
+	STRING(REGEX REPLACE ${flag} "" CMAKE_C_FLAGS_DEBUG ${CMAKE_C_FLAGS_DEBUG})
+	STRING(REGEX REPLACE ${flag} "" CMAKE_C_FLAGS_RELEASE ${CMAKE_C_FLAGS_RELEASE})
+	STRING(REGEX REPLACE ${flag} "" CMAKE_C_FLAGS_MINSIZEREL ${CMAKE_C_FLAGS_MINSIZEREL})
+	STRING(REGEX REPLACE ${flag} "" CMAKE_C_FLAGS_RELWITHDEBINFO ${CMAKE_C_FLAGS_RELWITHDEBINFO})
+
+	STRING(REGEX REPLACE ${flag} "" CMAKE_CXX_FLAGS ${CMAKE_CXX_FLAGS})
+	STRING(REGEX REPLACE ${flag} "" CMAKE_CXX_FLAGS_DEBUG ${CMAKE_CXX_FLAGS_DEBUG})
+	STRING(REGEX REPLACE ${flag} "" CMAKE_CXX_FLAGS_RELEASE ${CMAKE_CXX_FLAGS_RELEASE})
+	STRING(REGEX REPLACE ${flag} "" CMAKE_CXX_FLAGS_MINSIZEREL ${CMAKE_CXX_FLAGS_MINSIZEREL})
+	STRING(REGEX REPLACE ${flag} "" CMAKE_CXX_FLAGS_RELWITHDEBINFO ${CMAKE_CXX_FLAGS_RELWITHDEBINFO})
+
+ENDMACRO(_REMOVE_STRICT_FLAGS)
+
+MACRO(REMOVE_STRICT_FLAGS)
+
+	IF(CMAKE_COMPILER_IS_GNUCC)
+		_REMOVE_STRICT_FLAGS("-Wunused-parameter")
+		_REMOVE_STRICT_FLAGS("-Werror=[^ ]+")
+		_REMOVE_STRICT_FLAGS("-Werror")
+	ENDIF(CMAKE_COMPILER_IS_GNUCC)
+
+	IF(MSVC)
+		# TODO
+	ENDIF(MSVC)
+
+ENDMACRO(REMOVE_STRICT_FLAGS)
+
 
 MACRO(GET_BLENDER_VERSION)
 	FILE(READ ${CMAKE_SOURCE_DIR}/source/blender/blenkernel/BKE_blender.h CONTENT)