Revive L4Re target by farao · Pull Request #150885 · rust-lang/rust

farao · 2026-01-09T17:13:31Z

This revives the target for the L4Re OS. It changes the way, linking is done and adds aarch64 support and documentation including a maintainer for the target.

The update of the libc crate is necessary since only in 0.2.179 and higher is the fixed support for L4Re on uclibc.

rustbot · 2026-01-09T17:13:35Z

Some changes occurred in src/doc/rustc/src/platform-support

cc @Noratrieb

These commits modify the library/Cargo.lock file. Unintentional changes to library/Cargo.lock can be introduced when switching branches and rebasing PRs.

If this was unintentional then you should revert the changes before this PR is merged.
Otherwise, you can ignore this comment.

These commits modify compiler targets.
(See the Target Tier Policy.)

rustbot · 2026-01-09T17:13:37Z

r? @joboet

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rustbot · 2026-01-10T17:21:31Z

Some changes occurred in compiler/rustc_codegen_cranelift

cc @bjorn3

rust-analyzer is developed in its own repository. If possible, consider making this change to rust-lang/rust-analyzer instead.

cc @rust-lang/rust-analyzer

Some changes occurred in src/tools/clippy

cc @rust-lang/clippy

Some changes occurred in compiler/rustc_codegen_gcc

cc @antoyo, @GuillaumeGomez

Some changes occurred in GUI tests.

cc @GuillaumeGomez

Some changes occurred in compiler/rustc_attr_parsing

cc @jdonszelmann

Some changes occurred in HTML/CSS/JS.

cc @GuillaumeGomez, @lolbinarycat

GuillaumeGomez · 2026-01-10T17:22:55Z

Wrong rebase.

farao · 2026-01-10T17:29:24Z

Sorry for rebasing on an old commit by mistake

rust-bors · 2026-01-14T16:53:30Z

☔ The latest upstream changes (presumably #151107) made this pull request unmergeable. Please resolve the merge conflicts.

joboet

I can only comment on the library changes, those seem mostly fine to me.

View changes since this review

joboet · 2026-01-22T13:35:48Z

Does L4Re truly not support networking? All the necessary functions seem to be available in libc. What happens if you remove the L4Re special case from sys/net/connection/mod.rs?

Regarding the libc functions: L4Re's uclibc adaptation has a variety of these function which will when called just return an error or a disabled status code. I decided to put these in the libc crate because that should imo just bluntly mirror the functions when they exist, no matter if they are somehow disabled.

joboet · 2026-01-22T13:44:29Z

    #[allow(deprecated)]
    fn as_raw_stat(&self) -> &raw::stat {
-        unsafe { &*(self.as_inner().as_inner() as *const libc::stat64 as *const raw::stat) }
+        panic!("as_raw_stat not supported for L4Re");


How that? stat does appear in libc.

You're right, I'll change it back.

farao · 2026-01-29T09:51:59Z

Thanks for having a look! I realised that I need to disable some std tests for the std test suite to run through, I will make a small update to this PR this or next week.

Regarding networking (and to a somewhat lesser extent for fs): We do have initial support but that's opt-in and likely about to change, therefore we decided that this should be/stay disabled for now.

joboet · 2026-02-07T15:22:55Z

I'm just a bit worried about this removing the stable AsFd/... implementations for the sockets...

joboet · 2026-02-07T15:34:41Z

@rustbot author

rustbot · 2026-07-25T12:01:33Z

Any special-casing of Miri in the standard library requires review.

cc @rust-lang/miri

rustbot · 2026-07-25T12:01:36Z

This PR was rebased onto a different main commit. Here's a range-diff highlighting what actually changed.

Rebasing is a normal part of keeping PRs up to date, so no action is needed—this note is just to help reviewers.

farao · 2026-07-25T12:02:43Z

Rebased and moved to libc v. 0.2.189 for std because it includes important updates for L4Re.

RalfJung · 2026-07-25T19:22:45Z

@@ -1,6 +1,10 @@
 fn main() {
    // No `Command` on Miri and emscripten


This comment needs updating.

View changes since the review

Oh yes, thanks. Fixed.

farao · 2026-07-28T16:58:43Z

@joboet if you don't have the time to do the review, would you mind recommending or directly assigning a new reviewer for it?

joboet

Sorry for the delay, I've had some very busy weeks... the library changes look good (modulo two nits). I'll reassign for the compiler changes.

View changes since this review

joboet · 2026-07-29T13:39:02Z

r? compiler

saethlin · 2026-07-29T14:51:00Z

Compiler changes look contained to l4re, so I'm inclined to approve as soon as the library comments are addressed.

Fixes the builds of rustc and library/std for the L4Re target OS. A major change was done in linking binaries: The need for the L4Bender tool was removed and linking parameters are now fully configured in the rustc target config.

farao · 2026-07-30T13:54:32Z

Yeah, thanks for the review :) I fixed the two comments.

joboet · 2026-07-30T14:05:00Z

@bors r=@saethlin,joboet

rust-bors · 2026-07-30T14:05:04Z

📌 Commit 1ba6fd2 has been approved by saethlin,joboet

It is now in the queue for this repository.

Revive L4Re target This revives the target for the L4Re OS. It changes the way, linking is done and adds aarch64 support and documentation including a maintainer for the target. The update of the libc crate is necessary since only in 0.2.179 and higher is the fixed support for L4Re on uclibc.

Rollup of 14 pull requests Successful merges: - #159817 (Rename splat to avoid stable name collisions) - #160204 (Sync from portable simd 2026 07 30) - #150885 (Revive L4Re target) - #158057 (Don't escape U+FF9E and U+FF9F in `escape_debug_ext`) - #160125 (Fix typing mode handling in transmute checks and rustc_dump_layout) - #160152 (Create on-demand CI job for testing EC2 instances) - #159214 (std: improve the documentation of the random feature) - #159818 (Resolve vars before calling `unnormalized_obligations`) - #160040 (Split function parsing out of `item.rs` to a new module.) - #160044 (Add regression tests for fixed dead-code issues) - #160144 (renovate: group lockfiles PRs) - #160149 (Fix Windows on Arm PAC default) - #160175 (Try to recover less from incorrectly parsed const arg) - #160181 (Mark `Tuple` and `FnPtr` traits `#[fundamental]`)

JonathanBrouwer · 2026-07-30T22:06:06Z

💔 I suspect this PR failed tests as part of a rollup
@bors r-

After fixing the problem, consider running a try job for the failed job before re-approving.

Link to failure: #160222 (comment)

rust-bors · 2026-07-30T22:06:14Z

This pull request was unapproved.

This PR was contained in a rollup (#160222), which was unapproved.

View changes since this unapproval

rust-bors · 2026-07-31T08:07:46Z

☔ The latest upstream changes (presumably #160238) made this pull request unmergeable. Please resolve the merge conflicts by rebasing.

rustbot assigned joboet Jan 9, 2026

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farao force-pushed the main branch from 7e76bdd to e66e2d0 Compare January 10, 2026 17:21

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farao force-pushed the main branch from e66e2d0 to 9036110 Compare January 10, 2026 17:25

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farao force-pushed the main branch from 9036110 to cd3369f Compare January 14, 2026 11:44

joboet reviewed Jan 22, 2026

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rustbot added S-waiting-on-author Status: This is awaiting some action (such as code changes or more information) from the author. and removed S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. labels Feb 7, 2026

farao force-pushed the main branch from 567584b to f1d8522 Compare July 25, 2026 12:01

RalfJung reviewed Jul 25, 2026

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farao force-pushed the main branch 2 times, most recently from 3126dcf to af5aece Compare July 25, 2026 19:27

joboet approved these changes Jul 29, 2026

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Comment thread library/std/src/sys/random/mod.rs

Comment thread library/std/src/sys/net/connection/mod.rs Outdated

rustbot assigned adwinwhite and unassigned joboet Jul 29, 2026

saethlin assigned saethlin and unassigned adwinwhite Jul 29, 2026

L4Re: Repair build and move to rustc linking

1ba6fd2

Fixes the builds of rustc and library/std for the L4Re target OS. A major change was done in linking binaries: The need for the L4Bender tool was removed and linking parameters are now fully configured in the rustc target config.

farao force-pushed the main branch from af5aece to 1ba6fd2 Compare July 30, 2026 13:52

rust-bors Bot added S-waiting-on-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. and removed S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. labels Jul 30, 2026

jhpratt mentioned this pull request Jul 30, 2026

Rollup of 14 pull requests #160222

Closed

rust-bors Bot added S-waiting-on-author Status: This is awaiting some action (such as code changes or more information) from the author. and removed S-waiting-on-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. labels Jul 30, 2026

		@@ -1,6 +1,10 @@
		fn main() {
		// No `Command` on Miri and emscripten

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