May 2026 Monthly report

Overview

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

Project update

Please note that due to vacations and various events, we did not write a report for the month of April.

Our RustConf talk “Compiling the Linux kernel with gccrs” will also be given at EuroRust, in Barcelona, Spain. We still have to figure out how to organize all of the conferences that gccrs will be going to, with hopefully an appearance at GNU Cauldron and Kangrejos which happen around the same period.

Upstream has continued with our most recent batch of commits pushed earlier today. Activity around upstreaming had slowed down in May as the main GCC branch was frozen for the GCC 16.1 release, but is now resuming to our weekly target frequency.

The most important news this month is the start of GSoC with our two new students, Janet Chien and Enes Çevik!

Enes will be working on adding support for the alloc crate, a component on top of the core crate which allows for dynamic memory allocation. This crate is responsible for a lot of nice Rust types seen in most Rust programs, such as String or Vec, but also implements the memory-management types that Rust offers, such as Box or Rc. Support for this crate is important for general purpose Rust programs, as it is an essential part of the Rust standard library.

Janet will be focusing on our Drop infrastructure in order to automatically run “destructors” on Rust values. While this is important for preventing memory leaks, it is also essential for ensuring the correct behavior of Rust programs compiled with gccrs, as types that manage an inner resource will often clean up this ressource within their Drop implementation. For example, when a mutex guard is acquired, the lock is automatically released when the guard gets dropped. Without proper Drop calls, the lock is never released, and a lot of Rust programs would not function correctly.

Finally, Zhi Heng is joining us this summer as part of an Open Source Security internship and will be working on getting Linux to compile with gccrs. His work will focus on fixing gccrs bugs when interacting with the kernel crates and with core, but also on adding CI to enable us to easily test the compiler on kernel code. This will help ensure that no regressions are introduced as we continue working towards this objective.

On the technical side of things, we have made progress on our early name resolution failures and now properly separate namespaces for later uses of our resolution maps. This was a huge change in code, which affected all areas of the compiler, especially later in the pipeline, as so many processes rely on proper name resolution in order to work. As a result, all of the complex import and export structures within core now get resolved and inserted properly, and modules and imports get properly inserted in the types namespace, which makes gccrs more correct and more in line with rustc behavior. We ran into certain issues with our metadata exports, where certain modules and exports were not being properly output to our metadata files, which caused issues when linking complex crates together. This showed up when experimenting with the Linux kernel crates but was not caught by our testcases when previously working on our metadata. Once again, real code is proving to be very useful at identifying compiler bugs. This sparked a big rework of our metadata handling and created new issues for us, which we’ll address in the coming weeks.

Community call

We will have our next monthly community call on the 8th of June at 9am 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

• https://github.com/Rust-GCC/gccrs/issues/2500

• https://github.com/Rust-GCC/gccrs/issues/2376

Completed Activities

• Sync with upstream (2026-05-31): ca94c21cf8faa4a7364654a4377d31b01ba27efa PR4566
• gccrs: Register the Drop lang item PR4559
• gccrs: Fix ICE when parsing empty path expression PR4558
• ci: fix the issue reference scrapper when there’s no ref PR4555
• util: Switch VisType to an enum class and rename variants. PR4549
• testsuite: Add a testcase for issue 4158 PR4548
• testsuite: Add a testcase for issue 4159 PR4547
• testsuite: Add a testcase for issue 3537 PR4546
• Add feature gate for rustc_conststable attribute PR4542
• lex: Emit E0768 for empty non-decimal literals PR4541
• Sync with upstream (2026-04-29): c392d64098cc675c804ff4f516548d023a4fe29a PR4539
• Implement Block Label. PR4535
• gccrs: Fix ICE cloning trait functions without return types PR4532
• ci: parse and expand gccrs github’s issues PR4531
• Recognize `warn` and `deny` as built in attributes PR4528
• Do path resolution in types NS for all segments except the last one PR4527
• Fix ICE in get_functionexpr when cfg’d return type inside macro PR4526
• Sync with upstream (2026-04-13): e2174f54883a26687b3244246ec8e6154afccc0f PR4523
• Fix corrupted GIMPLE for const-compound-assignment PR4520
• Defer number literal evaluation to parser PR4516
• Add assert macro handler PR4513
• Clean up of ‘flag_nameresolution20’ mention, as this is no longer … PR4512
• Fix intrinsic error location PR4502
• lint: Fix ICE on error_marknode in unused variable linter PR4438

Contributors this month

• Fisnik Hasani (new contributor!)
• Jean Christian Cirstea (new contributor!)
• Jayant Chauhan
• Islam Imad
• Harishankar
• Zhi Heng
• Janet Chien
• Enes Çevik
• Marc Poulhiès
• Owen Avery
• Pierre-Emmanuel Patry
• Arthur Cohen

Overall Task Status

Bugs

Test Cases

Milestones Progress

Here is the list of overarching milestones gccrs is currently targeting. We’ll use the acronym in the following milestone tables, in the column named “OA Milest.”.