How to add preprocessor macros in VS code with NCS.

RE: How to add preprocessor macros in VS code with NCS.

liteyear — Thu, 13 Jun 2024 19:29:59 GMT

Phwoah, spent a couple of unexpected days re-inventing the wheel here. Loooooong story short, here's what I'm now using to define preprocessor macros:

At the bottom of my CMakeLists.txt I have the line:
1. include(${CMAKE_CURRENT_SOURCE_DIR}/private.cmake OPTIONAL)
I then have an (optional) private.cmake file in the same directory, which can be ignored from source control.
In that file I'm free to define developer-specific configuration, and even secrets.
In particular, I use this is create preprocessor defines:
1. target_compile_definitions(app PRIVATE NAME_OF_DEFINE=value)
2. which appears to the preprocessor as #define NAME_OF_DEFINE value

There's a lot I hate about this bastardisation of a basic concept, but it works, and has these nice features:

You can use quotes literally, to make the define a C string. Eg. NAME="value" becomes #define NAME "value"
Escaping special characters like $ is automagic - no sign of shell expansion (however, be careful of Escape Sequences (\x) and Variable References (${var}) - they might still be evaluated).
You can use anything else that CMake has available, too.
You can use the file as you see fit - version it, share it, hide it, keep variations, etc. This is much easier than the Build Configurations in VSCode, which sent me batty with all their mysterious parsing and regular corruption.
You can combine it with, say CMake's option command, and turn it off and on by setting an "Extra CMake argument" like -DWITH_FEATURE_A=ON in the Build Configuration. See here for more details.
1. Note I haven't tried this. The Extra CMake arguments setting is difficult to work with, but given how little is required of it it would probably work fine in this case. FWIW, my needs were a bit different and after a long search I went down the build type path instead to give me some Build Configuration based settings. It's a bit hard to imagine how this could be tied into CMakeLists.txt.

Before landing on this implementation I tried all the suggestions in this thread, and also considered CONFIG_COMPILER_OPT. But everything else turned out nasty.

RE: How to add preprocessor macros in VS code with NCS.

runsiv — Fri, 16 Feb 2024 13:22:35 GMT

Sorry for the late update. I don't really have any definitive answer.

"However it seems that this is added project wide for all build configurations. So lets say we have 2 build configs, build x and y. In build x, we want to add_compile_definitions(ENALBED), however in build y, we do not want it added."

I would say that the best way to solve this is to create multiple build configuration in VScode where you set in the build configuration the extra defines you want in the code with the

-DVAR...=...

. That was recommendation i got at least, the drawback is that it could be easily lost.

it is also possible to include a file from CMakeList.txt but I could not see how to tie to different builds right now.

I guess it could be possible to have multiple Cmakelist.txt but multiple cmakelist are normally for example example used for when you create out of tree drivers.

It is also possible to use custom Kconfig options as described here https://docs.nordicsemi.com/bundle/ncs-latest/page/zephyr/build/kconfig/tips.html that could also be an option. To include an additional config file as part of the build configuration.

Regards

Runar

RE: How to add preprocessor macros in VS code with NCS.

Frikkie Badenhorst — Fri, 16 Feb 2024 10:50:05 GMT

Do we have an update here?

RE: How to add preprocessor macros in VS code with NCS.

Frikkie Badenhorst — Fri, 09 Feb 2024 13:38:09 GMT

I look forward to hearing back from you!

RE: How to add preprocessor macros in VS code with NCS.

runsiv — Fri, 09 Feb 2024 07:23:59 GMT

I will check and get back to you

RE: How to add preprocessor macros in VS code with NCS.

runsiv — Fri, 09 Feb 2024 07:23:45 GMT

Interresting, It was the same thing that I saw on my computer while my coworker did not get the ""

I will investigate a bit

Regards

Runar

RE: How to add preprocessor macros in VS code with NCS.

Frikkie Badenhorst — Thu, 08 Feb 2024 14:30:23 GMT

[quote userid="122502" url="~/f/nordic-q-a/108157/how-to-add-preprocessor-macros-in-vs-code-with-ncs/468079"]Update: I got a coworker to test the same Cmake flag and it works on their computer. So You need to write -DVARIABLE=y in the add extra cmake argument and it should work. [/quote]

By -DVARIABLE=y I assume you mean -DENABLED=y as in your example? If that is the case, this solution is not working on my side as I have explained in my previous post:

[quote userid="105759" url="~/f/nordic-q-a/108157/how-to-add-preprocessor-macros-in-vs-code-with-ncs/468069"]

ENABLE_SOMETHING is not defined, the Q_DEFINE_THIS_MODULE(main) function should be called:

I then add an extra CMAKE argument:

However, we still get a build error on the line "Q_DEFINE_THIS_MODULE(main)", even though it should not be compiled in. You can also see from the first screenshot that intelli-sense does not grey out the line, indicating the macro is not seen.

[/quote]

Note the "y" instead of y was automatically added by the extension

RE: How to add preprocessor macros in VS code with NCS.

Frikkie Badenhorst — Thu, 08 Feb 2024 14:22:55 GMT

Testing this solution at the moment:

https://stackoverflow.com/questions/46886308/cmakelists-txt-how-to-include-conditional-preprocessor?noredirect=1&lq=1

Will keep you updated.

RE: How to add preprocessor macros in VS code with NCS.

Frikkie Badenhorst — Thu, 08 Feb 2024 14:07:19 GMT

Hi Runar, thanks that seems helpful!

However it seems that this is added project wide for all build configurations. So lets say we have 2 build configs, build x and y. In build x, we want to add_compile_definitions(ENALBED), however in build y, we do not want it added.

How do we go about doing that? Can we specify 2 seperate CMakelList.txt files?

RE: How to add preprocessor macros in VS code with NCS.

runsiv — Thu, 08 Feb 2024 13:59:08 GMT

Hi and thanks for the fast reply.

To solve it like you want we need to define the preproccesor macros for cmake with the calls as shown in this post on stack overflow

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

You can add variables with the add_compile_definitions()

I did a quick test with the following code

#include <stdio.h>

int main(void)
{
	printf("Hello World! %s\n", CONFIG_BOARD);
	#ifdef ENALBED
		printf("IT IS ENABLED \n");
	#else
		printf("IT IS NOT ENABLED \n");
	#endif

	return 0;
}

cmakeList.txt

cmake_minimum_required(VERSION 3.20.0)

find_package(Zephyr REQUIRED HINTS $ENV{ZEPHYR_BASE})
project(hello_world_cmake)
#add_compile_definitions(ENALBED) #ran the code with this commentet and not commented 

target_sources(app PRIVATE src/main.c)

output

*** Booting nRF Connect SDK v2.5.99-dev1 ***
Hello World! nrf52833dk_nrf52833
IT IS ENABLED 
*** Booting nRF Connect SDK v2.5.99-dev1 ***
Hello World! nrf52833dk_nrf52833
IT IS NOT ENABLED

I thought it would work if you added it as an argument in the build configuration. But either I'm doing something wrong or it does not work. So I need to investigate more why it is ignored. Configuring CMakeLists.txt works however. I got it working if I build with the command line and write is as -DVARIABLE=y. I will get back to you tomorrow.
Update: I got a coworker to test the same Cmake flag and it works on their computer. So You need to write -DVARIABLE=y in the add extra cmake argument and it should work.

Regards

Runar

RE: How to add preprocessor macros in VS code with NCS.

Frikkie Badenhorst — Thu, 08 Feb 2024 13:30:00 GMT

Thanks for the fast response, Runar. Good to know that different build configurations can use different proj.conf files.

I have read through the 2 links you have posted, however my original question on how to add a preprocessor macro remains.

I have tried adding extra CMAKE arguments, but it does not work. Lets take for example the below code snippet, where we want to define something (in this example we just name it ENABLE_SOMETHING). So if ENABLE_SOMETHING is defined, nothing should happen as the code is commented out. However, if ENABLE_SOMETHING is not defined, the Q_DEFINE_THIS_MODULE(main) function should be called:

I then add an extra CMAKE argument:

In all IDEs I have worked with, you were simply able to go to the project options, add a preprocessor macro and on you go (IAR example below):

RE: How to add preprocessor macros in VS code with NCS.

runsiv — Thu, 08 Feb 2024 12:31:04 GMT

Hi Frikkie

I would recommend having a look at this guide and this on how to add different build configurations for Vscode. At least for debugging I would suggest selecting build optimization debugging as it would include more debugging features. You can also create multiple build configurations for one project with different settings and you can specify in the build configuration which prj.conf you want the application to use.

From the build configuration window it is also possible to add extra cmake arguments

Regards

Runar