CMake: per-target CFLAG & CXXFLAG support

Applying cflags globally can be problematic especially with extern, intern libs.

Now flags from target named will be used when defined,
allowing for developers to define flags for modules they maintain.

Convention is CMAKE_CFLAGS_${UPPERCASE_TARGET_NAME}, (CXXFLAGS for C++).

eg: CMAKE_CFLAGS_BF_BLENDER, CMAKE_CFLAGS_MAKESDNA, CMAKE_CXXFLAGS_CYCLES_KERNEL

On Linux run `make help` for full list of names, MSVC shows these in the solution.

build_files/cmake/macros.cmake

@@ -196,8 +196,33 @@ function(blender_source_group
 endfunction()
 
 
+# Support per-target CMake flags
+# Read from: CMAKE_C_FLAGS_**** (made upper case) when set.
+#
+# 'name' should alway match the target name,
+# use this macro before add_library or add_executable.
+#
+# Optionally takes an arg passed to set(), eg PARENT_SCOPE.
+macro(add_cc_flags_custom_test
+	name
+	)
+
+	string(TOUPPER ${name} _name_upper)
+	if(DEFINED CMAKE_C_FLAGS_${_name_upper})
+		message(STATUS "Using custom CFLAGS: CMAKE_C_FLAGS_${_name_upper} in \"${CMAKE_CURRENT_SOURCE_DIR}\"")
+		set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${CMAKE_C_FLAGS_${_name_upper}}" ${ARGV1})
+	endif()
+	if(DEFINED CMAKE_CXX_FLAGS_${_name_upper})
+		message(STATUS "Using custom CXXFLAGS: CMAKE_CXX_FLAGS_${_name_upper} in \"${CMAKE_CURRENT_SOURCE_DIR}\"")
+		set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${CMAKE_CXX_FLAGS_${_name_upper}}" ${ARGV1})
+	endif()
+	unset(_name_upper)
+
+endmacro()
+
+
 # only MSVC uses SOURCE_GROUP
-function(blender_add_lib_nolist
+function(blender_add_lib__impl
 	name
 	sources
 	includes
@@ -225,6 +250,18 @@ function(blender_add_lib_nolist
 endfunction()
 
 
+function(blender_add_lib_nolist
+	name
+	sources
+	includes
+	includes_sys
+	)
+
+	add_cc_flags_custom_test(${name} PARENT_SCOPE)
+
+	blender_add_lib__impl(${name} "${sources}" "${includes}" "${includes_sys}")
+endfunction()
+
 function(blender_add_lib
 	name
 	sources
@@ -232,7 +269,9 @@ function(blender_add_lib
 	includes_sys
 	)
 
-	blender_add_lib_nolist(${name} "${sources}" "${includes}" "${includes_sys}")
+	add_cc_flags_custom_test(${name} PARENT_SCOPE)
+
+	blender_add_lib__impl(${name} "${sources}" "${includes}" "${includes_sys}")
 
 	set_property(GLOBAL APPEND PROPERTY BLENDER_LINK_LIBS ${name})
 endfunction()

source/blender/makesdna/intern/CMakeLists.txt

@@ -52,6 +52,8 @@ endif()
 
 # SRC_DNA_INC is defined in the parent dir
 
+add_cc_flags_custom_test(makesdna)
+
 add_executable(makesdna ${SRC} ${SRC_DNA_INC})
 
 # Output dna.c

source/blender/makesrna/intern/CMakeLists.txt

@@ -350,7 +350,10 @@ blender_include_dirs_sys(
 	"${GLEW_INCLUDE_PATH}"
 )
 
+add_cc_flags_custom_test(makesrna)
+
 add_executable(makesrna ${SRC} ${SRC_RNA_INC} ${SRC_DNA_INC})
+
 target_link_libraries(makesrna bf_dna)
 target_link_libraries(makesrna bf_dna_blenlib)
 

source/blenderplayer/CMakeLists.txt

@@ -63,6 +63,8 @@ if(WIN32 AND NOT UNIX)
 			COMPONENT Blenderplayer
 			DESTINATION ".")
 
+add_cc_flags_custom_test(blenderplayer)
+
 elseif(APPLE)
 	add_executable(blenderplayer ${EXETYPE} bad_level_call_stubs/stubs.c)
 	# setup Info.plist

source/creator/CMakeLists.txt

@@ -222,6 +222,8 @@ if(WITH_BUILDINFO)
 	add_dependencies(buildinfoobj buildinfo)
 endif()
 
+add_cc_flags_custom_test(blender)
+
 # message(STATUS "Configuring blender")
 if(WITH_PYTHON_MODULE)
 	add_definitions(-DWITH_PYTHON_MODULE)