Jasmine Tang

What I did for GSoc 2024

2024-08-22

Hi everyone, this article is a requirement for my GSoc Final Submission, linking directly to the submission.

This article will include the summary of my contribution, where you can find all my filed issues and PRs.

Introduction

This summer I worked on the gccrs project, a GCC Front-end for Rust.

gccrs is a project to implement the Rust programming languages from scratch in the GCC codebase in order for rust to be able to be compiled to a wider amount of targets. It currently targets the version 1.49 of Rust and is supported by Open Source Security and Embecosm.

By doing this, it helps with a couple things:

  • Targets architecture not available with rustc due to the use of LLVM. (SuperH for example, which powers the Dreamcast!)
  • Benefit from the existing GCC ecosystem.
  • Help with acceptance of Rust in the Linux kernel
  • Help with acceptance of Rust in other fields, where having multiple compilers helps.
  • Enable building Rust on targets with very old C++ compilers! (Targets with at least GCC version 4.8 (which released March 22, 2013) can build Rust)

Main contribution aspects

Overall, I contributed in 3 main aspects:

  • My main project - Inline Assembly in rust: I programmed the parser, set up the code infrastructure for TREE IR generation in the backend, along with AST, HIR lowering and typechecking.

  • CI/CD: I helped maintain and improve the CI/CD pipeline. This includes resolving dependency issues in GitHub Actions, adding support for 32 bit CI and glibc compliance CI. I also created a docker-compose dev environment for MacOS-based contributors, with all libraries and dependency installed; this helps us bypass MacOS's annoying build and link issues.

  • Code maintainance/Bug Fixes/Code Review: I maintained the code base via issues filed by my mentor and other contributors. I also helped fix some minor bugs in IR lowering and typechecking. I also help review some new, simple PRs for contributors.

Issues and PRs

Below is all the issues, PRs and commits I've made to the gccrs repository, up to Aug 22 2024, after producing this I ended up closing some resolved issues that has been silently addressed in some PRs.

The tables are produced via gh cli tool and some I use nvim btw love :)

Issues

Here's a formatted version of all my issues, up to Aug 22 2024, procured via gh issue list -A badumbatish --state all:

Issue Number Issue Status Issue Title Labels Filed Date
3102 OPEN Set up the rest of HIR pipeline in InlineAsm 2024-07-27T03:20:50Z
3099 OPEN parse_expr not stopping on => 2024-07-25T19:41:07Z
3072 OPEN asm parser lacking label parse functionality 2024-07-01T08:54:12Z
3069 OPEN Make asm parser stores parse result 2024-06-25T16:12:44Z
3062 CLOSED Add ExprType::InlineAsm variant to ExprType enum 2024-06-24T13:23:55Z
3061 OPEN Typechecking of asm! failed in let _ bug 2024-06-24T13:24:07Z
3057 OPEN asm! macro failed to exhaustively parse all of options(), clobber_abis(), and register operands bug, expansion 2024-06-18T13:32:24Z
3052 OPEN Fully incorporate tl::expected into InlineAsm parsing 2024-06-14T09:54:17Z
3051 CLOSED Remove unnecessary #include from rust-expr.h good-first-pr, cleanup 2024-07-11T09:23:53Z
3050 CLOSED Safe guard InlineAsm-related structs 2024-07-03T09:58:52Z
3048 OPEN Handle outer attributes properly for inline assembly 2024-06-14T09:55:37Z
2937 CLOSED Docker image and container for Mac 2024-05-10T14:53:25Z

The closed/filed rate is 4/8, which is not high. Through out writing the parser and the backend infra, I realized that there are these little issues that's just easier to just fix and not necessary filed. There is also issues that are discussed via hackmd notes between me and my mentor that are not necessarily filed via GitHub.

PRs

Here's a formatted version of all my pull requests, up to Aug 22 2024, procured via gh pr list -A badumbatish --state all:

PR Number PR Status PR Title Filed Date
3133 MERGED Fix the disorder struct and class in inline asm 2024-08-20T07:41:34Z
3119 OPEN Add running cicd 32bit 2024-08-04T19:47:37Z
3109 MERGED Inline asm resolve expr 2024-07-31T03:41:32Z
3103 MERGED Inline asm hir pipeline 2024-07-27T08:22:57Z
3098 MERGED Fix the parser's operand and flags storage 2024-07-25T16:38:11Z
3093 MERGED Change assertion of asm operand constructor 2024-07-21T22:46:28Z
3090 MERGED Added options for ParseMode 2024-07-20T07:48:51Z
3081 MERGED Pin node16 by allowing old version 2024-07-10T02:32:08Z
3074 MERGED Safe-guard InlineAsm structs 2024-07-01T00:43:59Z
3073 MERGED Store parse result of parse_format_string(s) 2024-07-01T00:24:42Z
3063 MERGED Added ExprType::InlineAsm 2024-06-23T18:06:02Z
3060 DRAFT Asm generic il codegen 2024-06-23T14:11:44Z
3059 MERGED Add test case for using asm! outside of unsafe 2024-06-22T06:40:27Z
3053 MERGED incorporate tl::expected into InlineAsm parsing 2024-06-14T06:08:01Z
3011 MERGED Remove cstddef header from rust-fmt 2024-05-19T03:03:05Z
3002 MERGED Make gccrs recognize negative_impls 2024-05-15T22:06:45Z
2982 MERGED Inline asm 2024-05-08T19:41:27Z
2981 OPEN Cleanup macro invoc 2024-05-08T17:47:46Z
2980 MERGED Fix all tests in execute to be \r\n 2024-05-08T06:47:12Z
2941 MERGED Add an alternative solution on MacOS 2024-04-05T03:10:57Z
2911 MERGED Store visibility properly in ExternalTypeItem: Fixes #2897 2024-03-09T22:46:59Z
2895 MERGED Add error emitting when we can't resolve id expr 2024-03-01T10:40:34Z
2874 MERGED First stab at issue 2855 by splitting the two maps 2024-02-25T21:13:02Z
2871 MERGED Fix FixMe in changing return type of builtin_macro_from_string() from BuiltinMacro to tl::optional/
 2024-02-23T21:22:58Z

The merged/filed rate is 22/25. Half of the PRs are easy to fix / fixable within a short amount of time (Code maintanence aspect). The other half is medium in difficulty, related to my summer project (Project aspect).

Introspection

Thinking back about the summer internship, I think I wasted a lot of time setting up dev envs, compiling and testing codes. Coding and building gcc/gccrs on a Macbook really sucks since the build step is confusing and there isn't a clear guide on how to do it. Compiling and testing requires a lot of time and for a person with ADHD, everytime I press that <space>b button, my mind goes to YouTube and Discord and it really disrupts my flow; I wish getting ADHD meds in America was easier.

As past Jasmine used to say:

idk its just hard to do stuff, i'm programming and it takes like x to compile and y minutes to test so i can't focus and then i go and change sth to test out my theory i have to wait like a bit for it to compile and test and then i just don't have any ideas cause i forgot them already and then an email comes in or a zulip msg comes in from my mentor and then fuck now i check them and then i was like "ok now what do i do" then the cycle continues

On the other hand, I did learn a lot. I learned how necessary it is to let the compiler do the work for you and how to design the software / compiler in a way that takes advantage of this as much as possible. This also applies to general stuff in my day to day tasks. Another thing is learning and using your tooling very well. This applies to neovim, git, bash shell, docker , etc etc etc; A more in-depth mastery of these tools allows me to iterate the development cycle faster and save more time to browse cute transbian on twitter :)

End words

It's been a blessing to contribute to gccrs this summer (and get paid for it hehe). I am mentored by Arthur Cohen and Pierre-Emmanuel "PEP" Patry; Arthur helped me with the direction of the project and code reviews while Pierre-Emmanuel provided me with code infrastructure navigation and PR code-reviews, both of which are much needed.

I am looking for internships/new grad gigs for 2025 in compiler and would love to connect with new people and be informed of new opportunities. Please contact me at either:

Thank you for reading :)