I declared a MMACRO in the main CmakeList.txt, using add_definitions( -DMMACRO ). Then when I check at CMakeList in a subfolder, where I use
if(COMMAND MMACRO)
#something here
endif()
It is not working. Does anyone know what should I do? Thanks.
how-to-check-if-a-macro-exists-in-cmake
copt the answer from the below link cmake: how to check if preprocessor is defined
This is to complete the answer by arrowd.
I also tried the COMPILE_DEFINITIONS option as mentioned above by arrowd unsuccessfully.
Following the documentation of CMake, at least for version 3.x, it turns out that when you call add_definitions() in CMake, it adds the definitions to the COMPILE_DEFINITIONS directory property.
Therefore, lets say you are defining the following as per your code:
add_definitions(-DOS=LINUX) To retrieve the string with the definitions added into the variable "MYDEFS" you can use the following lines in CMake:
get_directory_property(MYDEFS COMPILE_DEFINITIONS) MESSAGE( STATUS "Compile defs contain: " ${MYDEFS} ) Then you can check if in ${MYDEFS} the define you are looking for exists or not. For instance
if(MYDEFS MATCHES "^OS=" OR MYDEFS MATCHES ";OS=")
MESSAGE( STATUS "OS defined" )
else()
# You can define your OS here if desired
endif()
