Defining preprocessor options using Visual Studio Code

[CktDesigner]

I'm transitioning from SES to Visual Studio Code.

In SES, I can define multiple builds and then define preprocessor options (eg. -DOPTION1) for each build definition

I don't see a way to do this when using the nRF Connect SDK and Visual Studio Code.

(Note:  I know how to specify defines using the CMakeLists.txt file for all builds (using add_definitions(-DOPTION1) , but not on a "per-build" basis).

I'm using the NRF CONNECT extension in Visual Studio Code.

Thanks!

[Michal]

Hello,

When adding or editing a build configuration there is an option called "Extra CMake Arguments" with the blue "Add argument" button.

To get the edit the build configuration tab you can either right click on it or click the three dots next to it.

And here I added "-DOPTION1" as an argument.

I hope that answers your question.

Best regards,

Michal

[CktDesigner]

Thanks!

[CktDesigner]

Upon further testing...   This doesn't seem to work.

If I use the syntax you suggest, I get an error during the build process.    To fix the error, I must use a syntax like:

-DOPTION1:STRING="1"

But this isn't seen when my source files are compiled.

I have been successful at using a line in the CMakeLists.txt file:

add_definitions(-DOPTION1)

but this adds the define project-wide (not per build option)

Am I doing something wrong?

Thanks!

[Michal]

Hello,

Sorry, my earlier answer was incorrect. I have asked the extension developers and it looks like you do have to do it in a more manual way.

For now VS Code is missing this kind of CMake manipulation like SES.

He also linked me those two questions from StackOverlow that you may want to look at:

https://stackoverflow.com/questions/8564337/how-to-define-a-c-preprocessor-macro-through-the-command-line-with-cmake

https://stackoverflow.com/questions/9017573/define-preprocessor-macro-through-cmake

Best regards,

Michal

[Umer Mahmood]

any updates on this? Is there a better way available now to add preprocessor definitions per build configuration ?

[Michal]

Hello,

I have asked the developers and am awaiting their answer, but in the meantime could you take a look if CMake presets may be something relevant?

Best regards,

Michal

[Umer Mahmood]

I have already tried my best with CMake presets. But it does not seem to be a good solution, following is what I have tried:

CMakeLists.txt

option(CUSTOMBUILD "flag used to define all flags for custom build" n) #n by default
if(CUSTOMBUILD)
    #add some compilation flags
    target_compile_definitions(app PRIVATE DISABLE_SOMETHING=1)
else()
    #add some other compilation flags
endif(CUSTOMBUILD)
unset(CUSTOMBUILD CACHE)

Created a new build config with following Extra CMake arguments: 

-DCUSTOMBUILD=y

Saved the configuration as preset, it shows up in  CMakePresets.json as :

{
    "version": 2,
    "cmakeMinimumRequired": {
        "major": 3,
        "minor": 20
    },
    "configurePresets": [
        {
            "name": "build_custom",
            "displayName": "Build for nRF9160 DK NRF9160 Non Secure",
            "generator": "Ninja",
            "binaryDir": "${sourceDir}/build_custom",
            "cacheVariables": {
                "NCS_TOOLCHAIN_VERSION": "NONE",
                "BOARD": "nrf9160dk_nrf9160ns",
                "CUSTOMBUILD": "y",
                "CONF_FILE": "${sourceDir}/prj.conf",
                "DTC_OVERLAY_FILE": "${sourceDir}/nrf9160dk_nrf9160ns.overlay"
            }
        }
    ]
}

The problems with this approach are:

1. When another developer loads the build configuration, they are able to see the Extra CMake arguments filled from the CMakePresets. But afterwards, if someone goes to Edit Build Configuration, these extras are no more visible.
2. After a Prestine Build, extra presets are gone and have to be set again. 

My intention is to use the flags defined for custom build as:

#ifndef DISABLE_SOMETHING
// enable
#endif