We have a couple python scripts that invoke cpp to preprocess a file before doing further work on the contents (eg: at least GenerateCSS2PropertiesWebIDL.py and GenerateCSSPropsGenerated.py). These scripts should automatically use the dependencies from cpp and incorporate them in some way with the mozbuild action. Since this is specific to make, it should only be done when using the make backend.
We'll probably have to figure out how to handle this for other build backends at some point. The way the file generation part of it works is pretty generic--the generating function just returns a `set` of filenames.
I had filed bug 1399450 on a related issue--it might be worthwhile to fix that first so that we have a single implementation of "run the C preprocessor from a Python script", and then we can add proper dependency tracking to that and fix all the callers.
See Also: → bug 1399450
FWIW, bug 1452542 is changing the two files mentioned in comment 0 to use generated files rather than invoking preprocessor. Maybe we can close this bug once that one gets merged.
You need to log in before you can comment on or make changes to this bug.