cmake - Different compile flags for same file in different targets

Question

I would like to include a .cpp-file in two different targets (becoming two VS projects after running CMake). I would like to set different COMPILE_FLAGS for these projects.

However, when I do

SET_TARGET_PROPERTIES(myfile.cpp PROPERTIES COMPILE_FLAGS "flags1")
ADD_EXECUTABLE(project1 myfile.cpp)
SET_TARGET_PROPERTIES(myfile.cpp PROPERTIES COMPILE_FLAGS "flags2")
ADD_EXECUTABLE(project2 myfile.cpp)

the flags2 applies for both projects, so it seems like the properties are overwritten on line 3 and not considered on line 2. Is this true or am I missing something? Is there a way to solve this?

Answer 1

Apply the set_target_properties command to the projects and not to the source files:

add_executable(project1 myfile.cpp)
set_target_properties(project1 PROPERTIES COMPILE_FLAGS "flags1")
add_executable(project2 myfile.cpp)
set_target_properties(project2 PROPERTIES COMPILE_FLAGS "flags2")

The flags set on the target will apply to all sources within the target.