February 2024 Monthly report

Overview

Thanks again to Open Source Security, inc and Embecosm for their ongoing support for this project.

Project update

We have had an influx of potential GSoC applicants this month, with lots of new people joining our Zulip channel and GitHub repository. They have submitted a large number of pull-requests, and have started heavily participating in the compiler development chat - which we are really happy about! The potential applicants seem very motivated and eager to work on the project, which is very nice to see. Thank you all for your interest!

As a consequence, the amount of contributions has picked up - similarly to past years around this period. This increases our review load, but is also very productive.

On the upstream side, the tooling we had been working on is working nicely and speeding up the creation and testing of these commits. We are still going to improve it, but it is already proving to be useful. Since last month, we have upstreamed two patchsets in three weeks, with one more patchset being prepared for this week. This has enabled us to catch some minor issues we would not have discovered until much later, thanks to the wide range of architectures used by the GCC community.

Regarding technical contributions, progress continued on the borrow checker with multiple large pull-requests from Jakub currently being reviewed. These pull-requests concern the addition of variance analysis to the project, as well as the emission of more facts for the polonius-engine crate.

We have also made great progress on format_args!(), with the proper expansion of these macro invocations to their runtime components. Once these components are properly generated, it is relatively easy to implement the famous println!() macro - iterate on those components, calling the associated formatting function each time, and using stdout as a writer. Thanks to the work done by Philip on iterators, we are now able to have a functioning, but unoptimized println!() with gccrs - which is a huge milestone! Please note that the real println!() macro is a member of the std crate, not core, as it relies on dynamic allocation and locking in order to ensure a fast and safe access to the global operating system output streams.

A couple issues remain around the parsing of the format_args!() arguments, but we are expecting to take care of them soon. We will have to polish the integration of the Rust component responsible for parsing the format_args!() invocation, as there are build system subtleties to take in account.

We will soon get in touch with the GCC release maintainers in order to prepare this upcoming release, with the expectation of our frontend being part of GCC 14.1.

We would like to remind our readers that Jakub Dupak, one of our contributors working on integrating the polonius borrow-checker to gccrs, is currently finishing studying for his Master’s Degree and is looking for sponsorship to continue his work on the borrow checker. Please get in touch if you or your company would be interested in funding his work!

Community call

We will have our next monthly community call on the 18th of March at 10am UTC. You can subscribe to our calendar to see when the next one will be held. The call is open to everyone, even if you would just like to sit-in and listen. You can also subscribe to our mailing-list or join our Zulip chat to be notified of upcoming events.

• Jitsi link
• Calendar ID: 7060a0923ffebd3cb52b1afef35a28ff7b64f05962c9af84c23b1847f1f5f894@group.calendar.google.com
• Google calendar link
• iCal link

Call for contribution

This is a new section for particularly easy or interesting issues we would like folks external to the project to contribute to. We are available for mentoring and guiding you on their resolution. This is a great way to start making your mark on a complex project such as this one and to learn a lot in the process!

• Issue 2154

Derive macros (invoked through the #[derive(...)] attribute) should only be applied on type declarations - new structures, enumerations or unions. We need to report an error to the user when they try using such a macro on a non-type-declaration element - such as a function or trait.

The provided playground link (see the issue) showcases the expected behavior. The code it contains will need to be added as a test case to the project, with other test cases welcome.

This contribution will touch on our AST, our highest level intermediate representation in the compiler.

Check out our Contributing guidelines to get started on them or feel free to send us a message on Zulip or IRC!

Completed Activities

• Add error emitting when we can’t resolve id expr PR2895
• Make ```DefaultResolver``` visit more of the AST PR2891
• Ensure ```TupleStructPattern``` and ```TuplePattern``` have items PR2887
• Cleanup creation of lang items PR2880
• Fix FixMe in changing return type of builtin_{macrofromstring}() from BuiltinMacro to tl::optional<BuiltinMacro> PR2871
• Adjust error checks to match name resolution 2.0 PR2869
• Add base for implementing extern types PR2865
• gccrs: minor cleanup in langhook.type_formode PR2863
• gccrs: fix powif64 intrinsic PR2862
• Fix false positive for top-level ```AltPattern``` PR2861
• Return proper AST nodes from format_args!() expansion PR2859
• gccrs: Avoid *.bak suffixed tests - use dg-skip-if instead PR2857
• libgrust: Add missed commits for Changelog creation PR2853
• Fix variadic check on all function parameters PR2851
• Fix lookup of ```TuplePattern``` sub-pattern types PR2848
• gccrs: add powi intrinsics PR2845
• Update copyright years to 2024 PR2842
• gccrs: Fix typo in RegionConstraints instance PR2841
• Add testcase for #2314, fix formatting in macro error PR2840
• gccrs: Add testcase for matches!() macro PR2839
• [upstream] [2024-02-06] Prepare commits PR2831
• Start reusing rustc’s `format<sub>args</sub>` parser PR2822
• Fix rebinding imports PR2312
• Rust: Make ‘tree’-level ‘MAIN_NAMEP’ work PR2123

Contributors this month

• Sahil Yeole (new contributor!)
• Gyanendra Banjare (new contributor!)
• Jasmine Tang (new contributor!)
• Owen Avery
• Marc Poulhiès
• Thomas Schwinge

Overall Task Status

Test Cases

Bugs

Milestones Progress

Testing project

Planned Activities

• Proper extern type support, important for format_args!()
• Name resolution 2.0 fixes
• Start release preparations

Risks

Detailed changelog