Port `#[link]` to the new attribute parsing infrastructure #143193

JonathanBrouwer · 2025-06-29T13:34:29Z

Ports link to the new attribute parsing infrastructure for #131229 (comment)

bors · 2025-06-30T18:52:15Z

☔ The latest upstream changes (presumably #143233) made this pull request unmergeable. Please resolve the merge conflicts.

JonathanBrouwer · 2025-07-16T11:47:50Z

compiler/rustc_attr_data_structures/src/attributes.rs

+    PrintAttribute
+)]
+#[derive(HashStable_Generic)]
+pub enum NativeLibKind {


This type was moved here because it is needed for the link attribute and the original location caused a dependency cycle

JonathanBrouwer · 2025-07-16T11:50:16Z

tests/crashes/120175.rs


-#[link(name = "bar", import_name_type = "decorated", kind = "raw-dylib")]
+#[link(name = "bar", kind = "raw-dylib")]


This test is not testing for the invalid attribute, but instead for the link attribute on an extern type. Because attributes are parsed earlier and this attribute was invalid the error blocked the crash from happening. This is true for quite a few other of the test changes as well

JonathanBrouwer · 2025-07-16T11:51:39Z

tests/ui/attributes/malformed-attrs.rs

@@ -81,8 +81,7 @@
 #[export_stable = 1]
 //~^ ERROR malformed
 #[link]
-//~^ ERROR attribute must be of the form
-//~| WARN this was previously accepted by the compiler
+//~^ ERROR malformed


BREAKING CHANGE 1: A #[link] attribute which is not a list #[link(...)] used to be a warning future error, is now an error. This needs a crater run.

JonathanBrouwer · 2025-07-16T11:52:14Z

tests/ui/feature-gates/issue-43106-gating-of-builtin-attrs.rs

@@ -61,7 +61,7 @@
 #![doc = "2400"]
 #![cold] //~ WARN attribute should be applied to a function
 //~^ WARN this was previously accepted
-#![link()] //~ WARN attribute should be applied to an `extern` block
+#![link(name = "x")] //~ WARN attribute should be applied to an `extern` block


BREAKING CHANGE 2: A link attribute applied to an invalid target was not checked for syntactic correctness, it now is. The invalid target remains a warning, but the syntactic corectness is now checked

JonathanBrouwer · 2025-07-16T12:25:15Z

@rustbot ready
r? @jdonszelmann

Needs a crater run

rustbot · 2025-07-16T12:25:21Z

jdonszelmann is currently at their maximum review capacity.
They may take a while to respond.

rustbot · 2025-07-16T12:25:25Z

Some changes occurred in compiler/rustc_passes/src/check_attr.rs

cc @jdonszelmann

Some changes occurred in compiler/rustc_attr_parsing

cc @jdonszelmann

Some changes occurred in compiler/rustc_codegen_ssa

cc @WaffleLapkin

These commits modify the Cargo.lock file. Unintentional changes to 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.

Some changes occurred in compiler/rustc_attr_data_structures

cc @jdonszelmann

This PR changes a file inside tests/crashes. If a crash was fixed, please move into the corresponding ui subdir and add 'Fixes #' to the PR description to autoclose the issue upon merge.

jdonszelmann · 2025-07-16T12:42:04Z

@bors try @craterbot queue

Port `#[link]` to the new attribute parsing infrastructure Ports `link` to the new attribute parsing infrastructure for #131229 (comment) This rework is not yet finished, it is blocked on the `cfg` attribute being finished, since `link` takes a `cfg` attribute as argument `@rustbot` blocked

bors · 2025-07-16T12:43:15Z

⌛ Trying commit 6b10a20 with merge 4797991...

bors · 2025-07-16T15:00:28Z

☀️ Try build successful - checks-actions
Build commit: 4797991 (4797991aa2efb6d658150f10425b3f3b5d10eceb)

jdonszelmann · 2025-07-16T16:59:30Z

@craterbot queue

craterbot · 2025-07-16T16:59:32Z

🚨 Error: failed to parse the command

🆘 If you have any trouble with Crater please ask in t-infra on Zulip
ℹ️ Crater is a tool to run experiments across parts of the Rust ecosystem. Learn more

jdonszelmann · 2025-07-16T17:01:31Z

@craterbot check oops

craterbot · 2025-07-16T17:01:33Z

🚨 Error: failed to parse the command

🆘 If you have any trouble with Crater please ask in t-infra on Zulip
ℹ️ Crater is a tool to run experiments across parts of the Rust ecosystem. Learn more

jdonszelmann · 2025-07-16T17:01:53Z

@craterbot check

craterbot · 2025-07-16T17:02:19Z

👌 Experiment pr-143193 created and queued.
🤖 Automatically detected try build 4797991
🔍 You can check out the queue and this experiment's details.

ℹ️ Crater is a tool to run experiments across parts of the Rust ecosystem. Learn more

craterbot · 2025-07-19T06:19:26Z

🚧 Experiment pr-143193 is now running

ℹ️ Crater is a tool to run experiments across parts of the Rust ecosystem. Learn more

craterbot · 2025-07-20T10:18:38Z

🎉 Experiment pr-143193 is completed!
📊 628 regressed and 9 fixed (666127 total)
📰 Open the summary report.

⚠️ If you notice any spurious failure please add them to the denylist!
ℹ️ Crater is a tool to run experiments across parts of the Rust ecosystem. Learn more

JonathanBrouwer · 2025-07-20T10:47:45Z

These are a bunch of real regressions sadly.
As far as I can see, all regressions are caused crates depending on specifically by winit 0.13 and older (7 years+ old version) and glutin 0.6 and older (9 years+ old version). They are using the link attribute as #[link="dl"] which is invalid syntax. The breaking change is caused by "breaking change 1" above, which makes a future error into an error.

I don't think we should break these popular crates, even though they are very old versions.
On the other side, if this is truly a "future error", when will we make this an error? These old versions will likely be used forever by the hundreds of crates that showed up in crater that will never be updated to a modern version of winit/glutin.

Pinging @rust-lang/lang to decide
cc @jdonszelmann

traviscross · 2025-07-27T14:02:46Z

Thanks, we'll discuss.

Looking at the crater results, it's worth noting that almost all of the breakage is on GH repositories; very few crates on crates.io are broken.

joshtriplett · 2025-07-27T19:16:07Z

I wonder, could we ask the winit and glutin folks to upload a new micro version of those past major versions, with the only change being to fix the link syntax?

JonathanBrouwer · 2025-07-27T19:58:54Z

Sounds like a reasonable solution.
Alternatively we could accept specifically #[link="dl"] as a warning and error on all other invalid arguments, I'll leave T-lang to decide what's best

joshtriplett · 2025-07-30T15:16:09Z

@JonathanBrouwer Given the age of those crates, I don't think any addition of parsing logic here would be temporary. How much pain would that parsing logic be to handle the link="dl" case indefinitely?

JonathanBrouwer · 2025-07-30T15:21:34Z

@joshtriplett It should be easy, just an extra if statement at the start of the parser where it currently only accepts a list, just a few lines of code.

What should the attribute actually do? Afaik before this PR the attribute is completely ignored, so I propose to keep it that way. I'll double check that this is what happens

traviscross · 2025-07-31T03:58:10Z

We talked about this in lang triage.

Here's what I'd propose we do. Let's:

Take the breaking change for everything except #[link="dl"].
For #[link="dl"], this will trigger a deny-by-default FCW (that reports in dependencies).
- We can decide later, after the FCW has been out there, and based on a new crater run, whether we ever want to break this too.

@rfcbot fcp merge

rfcbot · 2025-07-31T03:58:12Z

Team member @traviscross has proposed to merge this. The next step is review by the rest of the tagged team members:

No concerns currently listed.

Once a majority of reviewers approve (and at most 2 approvals are outstanding), this will enter its final comment period. If you spot a major issue that hasn't been raised at any point in this process, please speak up!

cc @rust-lang/lang-advisors: FCP proposed for lang, please feel free to register concerns.
See this document for info about what commands tagged team members can give me.

rustbot added A-attributes Area: Attributes (`#[…]`, `#![…]`) T-compiler Relevant to the compiler team, which will review and decide on the PR/issue. S-blocked Status: Blocked on something else such as an RFC or other implementation work. labels Jun 29, 2025

JonathanBrouwer force-pushed the link_rework branch from 47c45bb to aaf7d53 Compare June 29, 2025 13:36

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jdonszelmann mentioned this pull request Jul 3, 2025

Tracking issue: Attribute refactor #131229

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JonathanBrouwer force-pushed the link_rework branch from aaf7d53 to d43b4b5 Compare July 15, 2025 20:19

rustbot added the A-run-make Area: port run-make Makefiles to rmake.rs label Jul 15, 2025

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JonathanBrouwer force-pushed the link_rework branch 5 times, most recently from 147aeec to 29b3648 Compare July 15, 2025 22:30

JonathanBrouwer added 3 commits July 16, 2025 13:45

Move NativeLibKind from rustc_session t- rust_attr_data_structures

3213d0e

Port the #[link] attribute to the new parser

6ad5110

Changes to the uitests

6b10a20

JonathanBrouwer force-pushed the link_rework branch from 29b3648 to 6b10a20 Compare July 16, 2025 11:47

JonathanBrouwer commented Jul 16, 2025

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rustbot added S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. and removed S-blocked Status: Blocked on something else such as an RFC or other implementation work. labels Jul 16, 2025

rustbot assigned jdonszelmann Jul 16, 2025

JonathanBrouwer marked this pull request as ready for review July 16, 2025 12:25

craterbot added S-waiting-on-crater Status: Waiting on a crater run to be completed. and removed S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. labels Jul 16, 2025

craterbot added S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. and removed S-waiting-on-crater Status: Waiting on a crater run to be completed. labels Jul 20, 2025

rfcbot added proposed-final-comment-period Proposed to merge/close by relevant subteam, see T-<team> label. Will enter FCP once signed off. disposition-merge This issue / PR is in PFCP or FCP with a disposition to merge it. labels Jul 31, 2025


		#[link(name = "bar", import_name_type = "decorated", kind = "raw-dylib")]
		#[link(name = "bar", kind = "raw-dylib")]

Port #[link] to the new attribute parsing infrastructure #143193

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Port #[link] to the new attribute parsing infrastructure #143193

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Port `#[link]` to the new attribute parsing infrastructure #143193

Port `#[link]` to the new attribute parsing infrastructure #143193

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