How to I contribute?

[iliakan]

I'd like to contribute some code to emscripten, including tests.

Usually, to contribute to a project, I do it like this:

1. Github fork, clone.
2. Make changes, test locally, run install/build commands.
3. Git push && create PR.

Here the process looks to be different, can you describe it in a bit more details?

In particular, I have troubles running the tests. Here's what I get by running directly from a cloned repo:

➜  emscripten git:(proxyfs-mmap) test/runner test_loop
posixtestsuite not found (run git submodule update --init?)
Test suites:
['test_core']
Running test_core: (1 tests)
(checking sanity from test runner)
runner: warning: LLVM version for clang executable "/usr/bin/clang" appears incorrect (seeing "14.0", expected "17") [-Wversion-check]
shared:CRITICAL: LLVM has not been built with the WebAssembly backend, clang reports:
...

Do I need a setup before running tests?

@sbc100 recommended to see https://emscripten.org/docs/contributing/developers_guide.html#developers-guide-setting-up.

It's great to have such article, but it's quite confusing.

• The article starts with a suggestion to run emsdk, but emsdk isn't a system utility. Should I first install it? Looks like some steps are missing.
• Then it suggests to install tot-upstream, but to contribute I'd really prefer a git clone. Is it possible?

These things may be obvious for you, but not for a newcomer ;(

Please advise a step-by-step way to get emscripten from github, run tests and push the changes.

[sbc100]

Emscripten depends on both llvm and on binaryen. The simplest way to get binaries for those tools is it use emsdk.

You can configure your local emscripten git checkout to use those either by setting up your own .emscripten config file to point to the emsdk version of these tools, or simply by using the emsdk config file directly with export EM_CONFIG=/path/to/emsdk/.emscripten.

If you want to build llvm and binaryen from source that is also an option but can take a long time and a lof of disk space, and is also unnecessary if you only want to contribute to emscirpten.

[sbc100]

(To be clear you need to export the EM_CONFIG environment variable so it would be export EM_CONFIG=/path/to/emsdk/.emscripten on linux or mac).

[iliakan]

Ok, so here are my next steps:

cd /opt/projects
git clone https://github.com/emscripten-core/emscripten.git
export EM_CONFIG=/opt/projects/emsdk/.emscripten
cd emscripten
test/runner test_loop

PASSED! 🥳

But then I try to run test_proxyfs from test/test_other.py - how to do that?

I tried test/runner test_proxyfs and test/runner test_other - both show errors:

posixtestsuite not found (run git submodule update --init?)
ERROR: could not find the following tests: core0.test_proxyfs
ERROR: could not find the following tests: core0.test_other.

[sbc100]

To the other tests you prefix the test name with other. e.g. ./test/runner other.test_proxyfs. Or to run them all your would run ./test/runner other.

[iliakan]

./test/runner other.test_proxyfs

Worked! 😮 🍾 🙇

[iliakan]

Thanks, it looks like I'm on the road to go further contributing 🎊