Move to ninja build system

Question

Prototype, WIP version of this is here: https://github.com/adafruit/circuitpython/compare/master...tannewt:ninja

该提问来源于开源项目：adafruit/circuitpython

Answer 1

Yesterday I read through the short ninja build manual and wonder if it's worth using the depfile feature that automatically discovers required header files by using gcc -MM -MF $out.d ... to write out all required headers for a given C file. Using depfile could help in several ways:

Besides eliminating the need to specify the implicit header dependencies for an given C file using | foo.h, it also makes the process more robust by ensuring no header files fall through. For example, the current generated ninja.build has:

I definitely want to use depfile for header dependencies. I don't think it'll work for mpversionhdr though because the file doesn't exist until built. I believe you need to be explicit for headers that are generated.

I've been experimenting by directly modifying the build.ninja file and can get past the genhdr/qstrdefs.enum.h error, but I don't trust the generated file is corrected because I haven't yet corrected for all the modified paths in the $include_pre, etc. Which is worrying: the ad-hoc sed commands, clearly are not fault tolerant and I think the sed functionality should be merged into the python later. What do you think?

The sed stuff should definitely be merged into one of the QSTR build scripts.