search

brettviren / moo

ruminants on module oriented programming
GNU General Public License v3.0
4 stars 4 forks source link

Add `moo render-deps` command to create `.d` files for build systems #26

Closed philiprodrigues closed 3 years ago

philiprodrigues commented 3 years ago

This PR adds a moo render-deps command that creates a .d file containing Makefile-style dependencies. The typical use is to use moo render-deps in conjunction with a moo render command: the render command creates an output file, while the render-deps command creates the .d file that describes the dependencies of that output file.

Also included are examples of how to use the generated .d file with a Makefile-based build and a CMake build. The CMake build requires the ninja backed generator. It looks like CMake 3.20 will be out soon, with support for using the .d files with the Makefile backend.

philiprodrigues commented 3 years ago

I edited buildsys.org but I don't have org-mode set up properly to recreate the "results" sections of the examples, so those need to be re-run.

brettviren commented 3 years ago

Thanks!

alessandrothea commented 3 years ago

Out of curiosity, how does the render-deps command differ from imports?

philiprodrigues commented 3 years ago

The .d files that render-deps generates consist of Makefile-style dependency lines like:

myfile.hpp : myfile.jsonnet sometemplate.hpp.j2 someotherimport.jsonnet

so render-deps needs to know ~everything that render knows (the target name, the jsonnet input and the template name). imports only takes one input (model or template), and it doesn't know the target name (myfile.hpp in this example). The .d file format is pretty simple, and one could alternatively try to stitch it together from moo import outputs in shell script/CMake, but after some discussion, Brett and I concluded that render-deps was the least bad option.

alessandrothea commented 3 years ago

Understood. daq-cmake uses moo imports but it has to be called several times to cover model, schema and templates. Looks like render-deps is going to simplify things quite a bit.

Thanks!

philiprodrigues commented 3 years ago

That was very much my motivation! I have some modifications to the daq-cmake code that use an earlier iteration of this functionality. Once i tidy it up, I'll make a daq-cmake PR for comments

alessandrothea commented 3 years ago

As usual, issues rather than PR are highly appreciated