Remove cmake: false in C target (and use CMake to finally create a nice, modular build ✨)?

[petervdonovan]

This is a continuation of the discussion started here. The proposal is to remove the cmake target property and to remove the logic in the C Generator that picks out which files to copy into the src-gen folder so that that logic can be implemented in CMake instead.

Code that could be removed from our compiler includes:

• CCompiler.java
• CCoreFilesUtils.java
• A few lines from TargetProperty.java
• Parts of doGenerate in CGenerator.java around here, here, and here
• Tests, including this, this, this, and this.
• Documentation, including this, this, and this, as well as this user warning

The total amount of code deleted might be only a few hundred lines, and that would be either partially or completely offset by the rewriting of the deleted code in CMake. However, I think complexity would be reduced in terms of:

• the amount of redundancy in the code we must maintain
• the number of complex tasks that must be handled in the C generator (not enough separation of concerns)
• the number of files (in distinct parts of the code base!) that must be touched in order to keep the main lingua-franca repo in sync with a change to the file structure of the C runtime
• the amount of explanation required to bring new users up to speed

Redundancy and separation of concerns are the primary motivators of this suggestion. An example of redundancy is that reactor-c already has a skeletal toy implementation of a CMake-only build process because we needed it for unit tests.

This issue is not very important to me. The reason why I bring it up is that after discussing it with Marten and Soroush, I am still not aware of use-cases for cmake: false, and if anyone knows of use-cases, I would like to understand them. To my knowledge, CMake probably can be used for cross-compilation to baremetal/embedded platforms; furthermore, if it cannot be used for that, then a drop-in replacement for CMake might be supplied using the build target property.

[petervdonovan]

This seems like a roadblock that I did not know about:

targetConfig.useCmake = false; // Force disable the CMake because
// it interferes with the Python target functionality

[Soroosh129]

Well, I forgot how CMake actually interferes here. Wouldn't setting targetConfig.noCompile = true be enough?

[petervdonovan]

Wouldn't setting targetConfig.noCompile = true be enough?

I suppose I will have to find out.

Hi @Soroosh129, I have a similar question -- It looks like the bash script in FedLauncher uses a compile command for remote federates. In order to move forward with this, would I need to update the bash script so that it invokes CMake?

This just came up because the way the C generator manages files is an obstacle for changes in the file structure of the runtime...

[Soroosh129]

In order to move forward with this, would I need to update the bash script so that it invokes CMake?

Yes, I think that has to be updated.