Hi everyone,Here is our monthly report for the month of March. The milestones table formatting is probably very poor here, so I would suggest checking it out on the website:
https://rust-gcc.github.io/2026/04/13/2026-03-monthly-report.htmlThere are some changes to the way milestones will be presented moving forward, mostly aimed at making it clearer when the compiler will be usable for certain purposes - being able to compile embedded Rust software, being able to produce proper embedded Rust binaries, being able to compile the Rust parts of the kernel, being able to run a kernel compiled using gccrs, and being able to compile general purpose Rust code.
Apart from this, the content between the website and this email is the same. Kindly, Arthur 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. - https://meet.jit.si/gccrs-community-call-april - Calendar ID:7060a0923ffebd3cb52b1afef35a28ff7b64f05962c9af84c23b1847f1f5f...@group.calendar.google.com
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_(builtins)` and `no_(builtins)` 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_(nonzero)` 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_(core)` 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 Category Last Month This Month Delta ------------- ------------ ------------ ------- TODO 401 406 +5 In Progress 117 118 +1 Completed 1225 1245 +20 Bugs Category Last Month This Month Delta ------------- ------------ ------------ ------- TODO 190 192 +2 In Progress 52 52 - Completed 605 619 +14 Test Cases TestCases Last Month This Month Delta ----------- ------------ ------------ ------- Passing 10598 10945 +347 Failed - - - XFAIL 73 73 - XPASS - - - 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.".Milestone Description Acronym
------------------------------------ ---------------------------------------------------------------------------------- ---------
Embedded Rust 1.49 compiler 0.1 The compiler is able to compile embedded Rust code EC 0.1
Embedded Rust 1.49 compiler 1.0 The compiler is able to compile embedded Rust code and produce valid executables EC 1.0
Rust-for-Linux compiler 0.1 The compiler is able to compile the Linux kernel LC 0.1
Rust-for-Linux compiler 1.0 The compiler is able to compile the Linux kernel and produce a runnable kernel LC 1.0
General purpose Rust 1.49 compiler The compiler passes the Rust 1.49 testsuite, and handles general purpose code GC
Milestone Last Month This Month Delta Start Date Completion Date Target OA Milest.
-------------------------------- ------------ ------------ ------- --------------- ----------------- -------- ------------
Rust-for-Linux 16% 25% +9% 1st Nov 2025 - - LC 0.1
Full core Late nameres issues 24% 24% - 1st Dec 2025 - - EC 0.1
Full core Early nameres issues 95% 95% - 1st Dec 2025 - - EC 0.1
Full core Typecheck issues 12% 12% - 21st Jan 2026 - - EC 0.1
RfL build_(error) 0% 100% +100% - - - LC 0.1
RfL compiler_(builtins) 0% 100% +100% - - - LC 0.1
RfL ffi 0% 40% +40% - - - LC 0.1
RfL macros 0% 0% - - - - LC 0.1
RfL uapi 0% 0% - - - - LC 0.1
RfL main kernel files 0% 0% - - - - LC 0.1
Upcoming Milestone Last Month This Month Delta Start Date Completion Date Target OA Milest.
------------------------------- ------------ ------------ ------- --------------- ----------------- --------------- ------------
Unstable RfL features 0% 0% - 7th Jan 2025 - 1st Aug 2025 LC 0.1
Generic Associated Types 0% 0% - 15th Mar 2025 - 15th Jun 2025 LC 0.1
RfL const generics 0% 0% - 1st May 2025 - 15th Jun 2025 LC 0.1
frontend plugin hooks 0% 0% - 15th May 2025 - 7th Jul 2025 GC
Handling the testsuite issues 0% 0% - 15th Sep 2024 - 15th Sep 2025 GC
main shim 0% 0% - 28th Jul 2025 - 15th Sep 2025 GC
Final core attributes 0% 0% - - EC 0.1
Core nightly features 0% 0% - - EC 0.1
Defered inference 0% 0% - - EC 0.1
Fn traits fixes 0% 0% - - EC 0.1
Recursive types 0% 0% - - EC 0.1
Drop 0% 0% - - EC 1.0
Pin, PinInit 0% 0% - - EC 1.0
Past Milestone Last Month This Month Delta Start Date Completion Date Target Target GCC
----------------------------------- ------------ ------------ ------- --------------- ----------------- --------------- ------------
Data Structures 1 - Core 100% 100% - 30th Nov 2020 27th Jan 2021 29th Jan 2021 GCC 14.1
Control Flow 1 - Core 100% 100% - 28th Jan 2021 10th Feb 2021 26th Feb 2021 GCC 14.1
Data Structures 2 - Generics 100% 100% - 11th Feb 2021 14th May 2021 28th May 2021 GCC 14.1
Data Structures 3 - Traits 100% 100% - 20th May 2021 17th Sep 2021 27th Aug 2021 GCC 14.1
Control Flow 2 - Pattern Matching 100% 100% - 20th Sep 2021 9th Dec 2021 29th Nov 2021 GCC 14.1
Macros and cfg expansion 100% 100% - 1st Dec 2021 31st Mar 2022 28th Mar 2022 GCC 14.1
Imports and Visibility 100% 100% - 29th Mar 2022 13th Jul 2022 27th May 2022 GCC 14.1
Const Generics 100% 100% - 30th May 2022 10th Oct 2022 17th Oct 2022 GCC 14.1
Initial upstream patches 100% 100% - 10th Oct 2022 13th Nov 2022 13th Nov 2022 GCC 14.1
Upstream initial patchset 100% 100% - 13th Nov 2022 13th Dec 2022 19th Dec 2022 GCC 14.1
Update GCC's master branch 100% 100% - 1st Jan 2023 21st Feb 2023 3rd Mar 2023 GCC 14.1
Final set of upstream patches 100% 100% - 16th Nov 2022 1st May 2023 30th Apr 2023 GCC 14.1
Borrow Checking 1 100% 100% - TBD 8th Jan 2024 15th Aug 2023 GCC 14.1
Procedural Macros 1 100% 100% - 13th Apr 2023 6th Aug 2023 6th Aug 2023 GCC 14.1
GCC 13.2 Release 100% 100% - 13th Apr 2023 22nd Jul 2023 15th Jul 2023 GCC 14.1
GCC 14 Stage 3 100% 100% - 1st Sep 2023 20th Sep 2023 1st Nov 2023 GCC 14.1
GCC 14.1 Release 100% 100% - 2nd Jan 2024 2nd Jun 2024 15th Apr 2024 GCC 14.1
format_(args)!() support 100% 100% - 15th Feb 2024 - 1st Apr 2024 GCC 14.1
GCC 14.2 100% 100% - 7th Jun 2024 15th Jun 2024 15th Jun 2024 GCC 14.2
GCC 15.1 100% 100% - 21st Jun 2024 31st Jun 2024 1st Jul 2024 GCC 15.1
Unhandled attributes 100% 100% - 1st Jul 2024 15th Aug 2024 15th Aug 2024 GCC 15.1
Inline assembly 100% 100% - 1st Jun 2024 26th Aug 2024 15th Sep 2024 GCC 15.1
Rustc Testsuite Adaptor 100% 100% - 1st Jun 2024 26th Aug 2024 15th Sep 2024 GCC 15.1
Borrow checker improvements 100% 100% - 1st Jun 2024 26th Aug 2024 15th Sep 2024 GCC 15.1
Deref and DerefMut improvements 100% 100% - 28th Sep 2024 25th Oct 2024 28th Dec 2024 GCC 15.1
Indexing fixes 100% 100% - 21st Jul 2024 25th Dec 2024 15th Nov 2024 GCC 15.1
Iterator fixes 100% 100% - 21st Jul 2024 25th Dec 2024 15th Nov 2024 GCC 15.1
Auto traits improvements 100% 100% - 15th Sep 2024 20th Jan 2025 21st Dec 2024 GCC 15.1
Lang items 100% 100% - 1st Jul 2024 10th Jan 2025 21st Nov 2024 GCC 15.1
alloc parser issues 100% 100% - 7th Jan 2025 31st Jun 2024 28th Jan 2025 GCC 15.1
std parser issues 100% 100% - 7th Jan 2025 31st Jun 2024 28th Jan 2025 GCC 16.1
Question mark operator 100% 100% - 15th Dec 2024 21st Feb 2025 21st Feb 2025 GCC 15.1
Name resolution 2.0 rework 100% 100% - 1st Jun 2024 - 1st Apr 2025 GCC 15.1
Macro expansion 100% 100% - 1st Jun 2024 - 1st Jan 2025 GCC 15.1
Remaining typecheck issues 100% 100% - 21st Oct 2024 - 1st Mar 2025 GCC 15.1
cfg-core 100% 100% - 1st Dec 2024 24th Mar 2025 1st Mar 2025 GCC 15.1
Codegen fixes 100% 100% - 7th Oct 2024 1st Apr 2025 1st Mar 2025 GCC 15.1
black_(box) intrinsic 100% 100% - 28th Oct 2024 - 28th Jan 2025 GCC 15.1
let-else 100% 100% - 28th Jan 2025 - 28th Feb 2025 GCC 15.1
Specialization 100% 100% - 1st Jan 2025 1st Apr 2025 1st Mar 2025 GCC 15.1
cfg-rfl 100% 100% - 7th Jan 2025 19th Mar 2025 15th Feb 2025 GCC 15.1
Downgrade to Rust 1.49 100% 100% - 14th Mar 2025 26th Mar 2025 1st Apr 2025 GCC 15.1
try blocks 100% 100% - 30th Jul 2025 GCC 16.1
while-let loops 100% 100% - 30th Jul 2025 GCC 16.1
offset_(of)!() builtin macro 100% 100% - 15th Mar 2025 4th Aug 2025 15th Aug 2025 GCC 16.1
Explicit generics with impl Trait 100% 100% - 28th Feb 2025 21st Jul 2025 28th Mar 2025 GCC 16.1
Final Inline assembly fixes 100% 100% - - GCC 16.1
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