March 2026 Monthly report

Overview

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

Project update

The first major news this month is the acceptance of our talk “Compiling the Linux kernel with gccrs” for RustConf 2026! Pierre-Emmanuel and Arthur will be going to Montreal, Canada, and look forward to meeting many of you! We have also submitted the same talk to EuroRust.

In terms of project management, we have decided to organize our current milestones into greater milestones to better reflect how useful the compiler will be. These overarching milestones are, so far, “embedded Rust compiler”, “Rust for Linux compiler” and “General purpose compiler”. This aims to reflect the fact that gccrs will soon be usable as a compiler for embedded Rust programs, which will only depend on core and crates depending on core. Once this is achieved, we will be iterating on top of this compiler to support the alloc crate as well as all of the Rust-for-Linux crates, which will enable GCC to compile the Linux kernel in its entirety. These can be further split in at least two - compiling software and creating a proper executable - for example, we may have a compiler able to handle embedded software, but which does not insert the necessary Drop calls, hence resulting in incorrect behavior. This is particularly important for the kernel, as types such as mutexes often have complex side effects as part of their Drop implementation. Not being able to release a mutex in programs compiled with gccrs would have particularly bad consequences, but being able to mis-compile the kernel is still an important milestone!

Indicating the target GCC version does not accurately reflect the state in which the compiler will be for that version. Our goal is to focus on these overarching milestones, rather than having a specific set of features in time for a specific GCC version. If you would like to use the latest gccrs features, you will need to build the compiler from source or use one of the releases we will put out on our Github page.

In terms of technical news, the compiler is now able to handle more kernel crates, with compiler_builtins being added to the list this month, and Pierre-Emmanuel focusing on the kernel’s ffi crate with only a few issues to resolve. We have also added an equivalent to rustc ‘s -Zcrate-attr command line option, which enables passing attributes when invoking gccrs. This is particularly helpful for our friends fuzzing the compiler, as gccrs now properly handles - and requires - the #![no_core] nightly attribute to compile code without depending on core. For name resolution, we have once again had to rework our internal data structures and handling of path resolution, as we realized that path resolution must first be done in the types namespace, regardless of which namespace we are trying to resolve a path in. This is due to imports and modules always being inserted in the types namespace. While the changes are simple, they have consequences to much of the codebase and require multiple refactoring to many of our visitors.

Finally, the deadline for GSoC proposals has passed - we have received 7 proposals this year and are currently reviewing them. They are once again of really high quality, and we thank every applicant who has submitted one :)

Community call

We will have our next monthly community call on the 27th of April 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

• Fix ICE in unused var when we hit unit const type PR4518
• Add cttz and cttz_nonzero support PR4511
• Replace usages of `chainon` PR4508
• Strip down 1.0 resolver PR4506
• Delete macro attribute input PR4505
• rust: Fix ICE in function_{setparameters} PR4501
• gccrs: Fix ICE caused by TypeCheckBase::parse_reproptions PR4500
• Improve unit struct matching PR4499
• Fix glob import all ICE issue PR4498
• Remove redundant expand visitor overloads PR4497
• gccrs: Add new test cases for old issues PR4494
• Sync with upstream (2026-03-18): 1c73a21caf2dc83ced30f10076a682ea26e1ba71 PR4491
• Deduplicate some functions within PointerVisitor PR4489
• Accepts `compiler<sub>builtins</sub>` and `no<sub>builtins</sub>` attribute. PR4488
• Use pretty printer instead ofcall to open_memstream PR4487
• testsuite:Add a testcase for setup_{associatedtypes} PR4485
• Add ability to inject inner attributes from CLI PR4484
• Add enum items to value namespace as well PR4480
• Squashing local commits PR4468
• Intrinsic: Add `ctlz` and `ctlz<sub>nonzero</sub>` intrinsics PR4467
• Add no_std to builtin attributes PR4466
• Sync with upstream (2026-03-05): 0970bb8565616f61c6b7a7dd0edbc829b0064703 PR4464
• enforce function qualifier order PR4463
• feat: Implement `no<sub>core</sub>` feature gate check PR4462
• Fix match arm scope PR4460
• Intrinsic refactor PR4459
• Disambiguate identifier and path patterns PR4455
• gccrs: Fix 128-bit non-decimal integer literal saturation PR4454
• intrinsic: Add bswap intrinsic PR4452
• resolve: Fix ICE on ambiguous glob re-exports PR4451
• Prevent error emission with multiple wildcards PR4450
• rust: Explicitly instantiate FFIVec<Piece> template PR4446
• lint: Fix ICE on error_marknode in unused variable linter PR4438
• Improve path resolution PR4428
• expand: Add error check if derive has wrong item PR4359
• nr1.0: Remove support in checking phases PR4108

Contributors this month

• Mohamed Ali (new contributor!)
• Egas Ribeiro (new contributor!)
• Ahmed Said (new contributor!)
• Philipp Gesang (new contributor!)
• Hritam Shrivastava (new contributor!)
• Enes Çevik (new contributor!)
• Islam Imad
• Jayant Chauhan
• Harishankar
• 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.”.