Rustdoc label trait feature by ThierryBerger · Pull Request #157058 · rust-lang/rust

ThierryBerger · 2026-05-28T12:04:38Z

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Part of Tracking Issue for doc_label_trait #156865
parse #[doc(label_trait)]
render it in html
add some parsing tests (for the unstable feature)
add some html tests
Render a color from a hash from its full path -> ⚠️ some colors may be ugly, but we have a path forward with the color argument.

Should the following be out of scope ?

Parse color (#[doc(label_trait(color="0xff0000")])
display a small colored indicator (with a hover/first letter?) when a type implementing a label_trait is listed outside of its main page
Some Integration with rust analyzer

rustbot · 2026-05-28T12:04:42Z

Some changes occurred in compiler/rustc_attr_parsing

cc @jdonszelmann, @JonathanBrouwer

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

cc @jdonszelmann, @JonathanBrouwer

Some changes occurred in HTML/CSS/JS.

cc @GuillaumeGomez, @lolbinarycat

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 compiler/rustc_hir/src/attrs

cc @jdonszelmann, @JonathanBrouwer

rustbot · 2026-05-28T12:04:45Z

r? @fmease

rustbot has assigned @fmease.
They will have a look at your PR within the next two weeks and either review your PR or reassign to another reviewer.

Use r? to explicitly pick a reviewer

Why was this reviewer chosen?

The reviewer was selected based on:

Owners of files modified in this PR: rustdoc
rustdoc expanded to 9 candidates
Random selection from GuillaumeGomez, camelid, fmease, lolbinarycat, notriddle

ThierryBerger · 2026-05-28T12:31:43Z

This is mostly a copy from notable_trait, should be updated.

View changes since the review

Should not be here, only in rustdoc book considering it's a rustdoc attribute.

I removed it, but seeing src/doc/unstable-book/src/language-features/doc-notable-trait.md is making me push back lightly on that, are you sure about your feedback? - or should we clean up other doc attributes that shouldn't be here (in other pr)?

ThierryBerger · 2026-05-28T12:33:05Z

+    /// Relative URL to the trait page, or empty when not linkable.
+    href: String,


should it be an option?

View changes since the review

I think we should always link to the trait, so I'd say no.

Maybe doc_hidden would make us not be able to do so ? It would be quite far-fetched to add label_trait to doc_hidden but... Maybe other cases like... visibility? not sure.

GuillaumeGomez · 2026-05-28T15:28:17Z

Render a color from a hash from DefId -> ⚠️ is that an issue? color won't be stable between releases.

I would generated the color hash from the trait path (so crate::Trait for current crate, etc). Like that it will be stable across releases.

GuillaumeGomez · 2026-05-28T15:35:16Z

+
+    let Some(impls) = cx.cache().impls.get(&did) else { return Vec::new() };
+
+    let mut out: Vec<LabelTraitInfo> = impls


Instead of using a Vec, would be better to use a BTreeMap. It's sorted on insert and prevents duplications.

View changes since the review

I changed to do that but then collect it to Vec, keeping this discussion opened as I'm not sure if you meant something else.

ThierryBerger · 2026-05-28T18:31:42Z

+            // FIXME: valid for traits, should be checked in attr_parsing
+            label_trait: _,


should we have strong verification on which items those are applied?

View changes since the review

Veykril

Could you remove the two rust-analyzer changes please? They don't do anything as is so they will likely cause unnecessary conflicts for us

View changes since this review

rust-log-analyzer · 2026-05-28T20:38:14Z

The job aarch64-gnu-llvm-21-1 failed! Check out the build log: (web) (plain enhanced) (plain)

Click to see the possible cause of the failure (guessed by this bot)


841 LL | #[repr]
842    | ^^^^^^^
843 
- error: valid forms for the attribute are `#[doc = "string"]`, `#[doc(alias)]`, `#[doc(attribute)]`, `#[doc(auto_cfg)]`, `#[doc(cfg)]`, `#[doc(fake_variadic)]`, `#[doc(hidden)]`, `#[doc(html_favicon_url)]`, `#[doc(html_logo_url)]`, `#[doc(html_no_source)]`, `#[doc(html_playground_url)]`, `#[doc(html_root_url)]`, `#[doc(include)]`, `#[doc(inline)]`, `#[doc(issue_tracker_base_url)]`, `#[doc(keyword)]`, `#[doc(masked)]`, `#[doc(no_default_passes)]`, `#[doc(no_inline)]`, `#[doc(notable_trait)]`, `#[doc(label_trait)]`, `#[doc(passes)]`, `#[doc(plugins)]`, `#[doc(rust_logo)]`, `#[doc(search_unbox)]`, `#[doc(spotlight)]`, and `#[doc(test)]`
+ error: valid forms for the attribute are `#[doc = "string"]`, `#[doc(alias)]`, `#[doc(attribute)]`, `#[doc(auto_cfg)]`, `#[doc(cfg)]`, `#[doc(fake_variadic)]`, `#[doc(hidden)]`, `#[doc(html_favicon_url)]`, `#[doc(html_logo_url)]`, `#[doc(html_no_source)]`, `#[doc(html_playground_url)]`, `#[doc(html_root_url)]`, `#[doc(include)]`, `#[doc(inline)]`, `#[doc(issue_tracker_base_url)]`, `#[doc(keyword)]`, `#[doc(masked)]`, `#[doc(no_default_passes)]`, `#[doc(no_inline)]`, `#[doc(notable_trait)]`, `#[doc(passes)]`, `#[doc(plugins)]`, `#[doc(rust_logo)]`, `#[doc(search_unbox)]`, `#[doc(spotlight)]`, and `#[doc(test)]`
845   --> $DIR/malformed-attrs.rs:41:1
846    |
847 LL | #[doc]

878 LL | | }
879    | |_^
880 
- error: valid forms for the attribute are `#[doc = "string"]`, `#[doc(alias)]`, `#[doc(attribute)]`, `#[doc(auto_cfg)]`, `#[doc(cfg)]`, `#[doc(fake_variadic)]`, `#[doc(hidden)]`, `#[doc(html_favicon_url)]`, `#[doc(html_logo_url)]`, `#[doc(html_no_source)]`, `#[doc(html_playground_url)]`, `#[doc(html_root_url)]`, `#[doc(include)]`, `#[doc(inline)]`, `#[doc(issue_tracker_base_url)]`, `#[doc(keyword)]`, `#[doc(masked)]`, `#[doc(no_default_passes)]`, `#[doc(no_inline)]`, `#[doc(notable_trait)]`, `#[doc(label_trait)]`, `#[doc(passes)]`, `#[doc(plugins)]`, `#[doc(rust_logo)]`, `#[doc(search_unbox)]`, `#[doc(spotlight)]`, and `#[doc(test)]`
+ error: valid forms for the attribute are `#[doc = "string"]`, `#[doc(alias)]`, `#[doc(attribute)]`, `#[doc(auto_cfg)]`, `#[doc(cfg)]`, `#[doc(fake_variadic)]`, `#[doc(hidden)]`, `#[doc(html_favicon_url)]`, `#[doc(html_logo_url)]`, `#[doc(html_no_source)]`, `#[doc(html_playground_url)]`, `#[doc(html_root_url)]`, `#[doc(include)]`, `#[doc(inline)]`, `#[doc(issue_tracker_base_url)]`, `#[doc(keyword)]`, `#[doc(masked)]`, `#[doc(no_default_passes)]`, `#[doc(no_inline)]`, `#[doc(notable_trait)]`, `#[doc(passes)]`, `#[doc(plugins)]`, `#[doc(rust_logo)]`, `#[doc(search_unbox)]`, `#[doc(spotlight)]`, and `#[doc(test)]`
882   --> $DIR/malformed-attrs.rs:76:1
883    |
884 LL | #[doc]


The actual stderr differed from the expected stderr
To update references, rerun the tests and pass the `--bless` flag
To only update this specific test, also pass `--test-args attributes/malformed-attrs.rs`

error: 1 errors occurred comparing output.
status: exit status: 1
command: env -u RUSTC_LOG_COLOR RUSTC_ICE="0" RUST_BACKTRACE="short" "/checkout/obj/build/aarch64-unknown-linux-gnu/stage2/bin/rustc" "/checkout/tests/ui/attributes/malformed-attrs.rs" "-Zthreads=1" "-Zsimulate-remapped-rust-src-base=/rustc/FAKE_PREFIX" "-Ztranslate-remapped-path-to-local-path=no" "-Z" "ignore-directory-in-diagnostics-source-blocks=/cargo" "-Z" "ignore-directory-in-diagnostics-source-blocks=/checkout/vendor" "--sysroot" "/checkout/obj/build/aarch64-unknown-linux-gnu/stage2" "--target=aarch64-unknown-linux-gnu" "--check-cfg" "cfg(test,FALSE)" "--error-format" "json" "--json" "future-incompat" "-Ccodegen-units=1" "-Zui-testing" "-Zdeduplicate-diagnostics=no" "-Zwrite-long-types-to-disk=no" "-Cstrip=debuginfo" "--emit" "metadata" "-C" "prefer-dynamic" "--out-dir" "/checkout/obj/build/aarch64-unknown-linux-gnu/test/ui/attributes/malformed-attrs" "-A" "unused" "-W" "unused_attributes" "-A" "internal_features" "-A" "incomplete_features" "-A" "unused_parens" "-A" "unused_braces" "-Crpath" "-Cdebuginfo=0" "-Lnative=/checkout/obj/build/aarch64-unknown-linux-gnu/native/rust-test-helpers"
stdout: none
--- stderr -------------------------------
error[E0539]: malformed `cfg` attribute input
##[error]  --> /checkout/tests/ui/attributes/malformed-attrs.rs:106:1
   |
---
   |
   = note: for more information, visit <https://doc.rust-lang.org/reference/attributes/diagnostics.html#lint-check-attributes>
help: the following are the possible correct uses
   |
LL | #[forbid(lint1)]
   |         +++++++
LL | #[forbid(lint1, lint2, ...)]
   |         +++++++++++++++++++
LL | #[forbid(lint1, lint2, lint3, reason = "...")]
   |         +++++++++++++++++++++++++++++++++++++

error: the `#[proc_macro]` attribute is only usable with crates of the `proc-macro` crate type
##[error]  --> /checkout/tests/ui/attributes/malformed-attrs.rs:103:1
   |
LL | #[proc_macro = 18]
   | ^^^^^^^^^^^^^^^^^^

error: the `#[proc_macro_attribute]` attribute is only usable with crates of the `proc-macro` crate type
##[error]  --> /checkout/tests/ui/attributes/malformed-attrs.rs:120:1
   |
---
   |
LL | #[allow_internal_unsafe = 1]
   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = help: add `#![feature(allow_internal_unsafe)]` to the crate attributes to enable
   = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date

error[E0539]: malformed `windows_subsystem` attribute input
##[error]  --> /checkout/tests/ui/attributes/malformed-attrs.rs:26:1
   |
LL | #![windows_subsystem]
---
   | ^^^^^^^^^^^^^^^^^^^^ expected this to be a list
   |
help: must be of the form
   |
LL | #[rustc_confusables("name1", "name2", ...)]
   |                    +++++++++++++++++++++++

error: `#[rustc_confusables]` attribute cannot be used on functions
##[error]  --> /checkout/tests/ui/attributes/malformed-attrs.rs:36:1
   |
---
help: try changing it to one of the following valid forms of the attribute
   |
LL | #[rustc_macro_transparency = "opaque"]
   |                            ++++++++++
LL | #[rustc_macro_transparency = "semiopaque"]
   |                            ++++++++++++++
LL | #[rustc_macro_transparency = "transparent"]
   |                            +++++++++++++++

error: `#[rustc_macro_transparency]` attribute cannot be used on functions
---
   | ^^^^^^^^^^^^^^ expected this to be a list
   |
help: must be of the form
   |
LL | #[rustc_align(<alignment in bytes>)]
   |              ++++++++++++++++++++++

error[E0539]: malformed `optimize` attribute input
##[error]  --> /checkout/tests/ui/attributes/malformed-attrs.rs:56:1
   |
---
LL | #[optimize(none)]
   |           ++++++
LL | #[optimize(size)]
   |           ++++++
LL | #[optimize(speed)]
   |           +++++++

error[E0565]: malformed `cold` attribute input
##[error]  --> /checkout/tests/ui/attributes/malformed-attrs.rs:58:1
   |
---
   |               didn't expect any arguments here
   |
help: must be of the form
   |
LL - #[unsafe(naked())]
LL + #[unsafe(naked)]
   |

error[E0565]: malformed `track_caller` attribute input
##[error]  --> /checkout/tests/ui/attributes/malformed-attrs.rs:66:1
   |
---
   | ^^^^^^^^^^^^^^^^^ expected this to be a list
   |
help: must be of the form
   |
LL | #[target_feature(enable = "feat1, feat2")]
   |                 +++++++++++++++++++++++++

error[E0565]: malformed `export_stable` attribute input
##[error]  --> /checkout/tests/ui/attributes/malformed-attrs.rs:80:1
   |
---

error[E0565]: malformed `proc_macro` attribute input
##[error]  --> /checkout/tests/ui/attributes/malformed-attrs.rs:103:1
   |
LL | #[proc_macro = 18]
   | ^^^^^^^^^^^^^----^
   |              |
   |              didn't expect any arguments here
   |
help: must be of the form
   |
LL - #[proc_macro = 18]
LL + #[proc_macro]
   |

error[E0539]: malformed `instruction_set` attribute input
##[error]  --> /checkout/tests/ui/attributes/malformed-attrs.rs:110:1
   |
---
   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected this to be a list
   |
help: must be of the form
   |
LL | #[patchable_function_entry(prefix_nops = m, entry_nops = n)]
   |                           +++++++++++++++++++++++++++++++++

error[E0565]: malformed `coroutine` attribute input
##[error]  --> /checkout/tests/ui/attributes/malformed-attrs.rs:115:5
   |
---
   |
   = note: for more information, visit <https://doc.rust-lang.org/reference/procedural-macros.html#derive-macros>
help: try changing it to one of the following valid forms of the attribute
   |
LL | #[proc_macro_derive(TraitName)]
   |                    +++++++++++
LL | #[proc_macro_derive(TraitName, attributes(name1, name2, ...))]
   |                    ++++++++++++++++++++++++++++++++++++++++++

error[E0539]: malformed `must_not_suspend` attribute input
##[error]  --> /checkout/tests/ui/attributes/malformed-attrs.rs:132:1
   |
---
   |
   = note: for more information, visit <https://doc.rust-lang.org/reference/items/external-blocks.html#the-link_ordinal-attribute>
help: must be of the form
   |
LL |     #[link_ordinal(ordinal)]
   |                   +++++++++

error[E0565]: malformed `ffi_const` attribute input
##[error]  --> /checkout/tests/ui/attributes/malformed-attrs.rs:169:5
   |
---
   |
   = note: for more information, visit <https://doc.rust-lang.org/reference/attributes/debugger.html#the-debugger_visualizer-attribute>
help: must be of the form
   |
LL | #[debugger_visualizer(natvis_file = "...", gdb_script_file = "...")]
   |                      ++++++++++++++++++++++++++++++++++++++++++++++

error[E0565]: malformed `automatically_derived` attribute input
##[error]  --> /checkout/tests/ui/attributes/malformed-attrs.rs:188:1
   |
---
   |
   = note: for more information, visit <https://doc.rust-lang.org/reference/macros-by-example.html#the-macro_use-attribute>
help: try changing it to one of the following valid forms of the attribute
   |
LL - #[macro_use = 1]
LL + #[macro_use(name1, name2, ...)]
   |
LL - #[macro_use = 1]
LL + #[macro_use]
   |

---
   |
LL | #[repr]
   | ^^^^^^^

error: valid forms for the attribute are `#[doc = "string"]`, `#[doc(alias)]`, `#[doc(attribute)]`, `#[doc(auto_cfg)]`, `#[doc(cfg)]`, `#[doc(fake_variadic)]`, `#[doc(hidden)]`, `#[doc(html_favicon_url)]`, `#[doc(html_logo_url)]`, `#[doc(html_no_source)]`, `#[doc(html_playground_url)]`, `#[doc(html_root_url)]`, `#[doc(include)]`, `#[doc(inline)]`, `#[doc(issue_tracker_base_url)]`, `#[doc(keyword)]`, `#[doc(masked)]`, `#[doc(no_default_passes)]`, `#[doc(no_inline)]`, `#[doc(notable_trait)]`, `#[doc(passes)]`, `#[doc(plugins)]`, `#[doc(rust_logo)]`, `#[doc(search_unbox)]`, `#[doc(spotlight)]`, and `#[doc(test)]`
##[error]  --> /checkout/tests/ui/attributes/malformed-attrs.rs:41:1
   |
LL | #[doc]
   | ^^^^^^
   |
---
   | ^^^^^^^^^^^^^
   |
   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
   = note: for more information, see issue #57571 <https://github.com/rust-lang/rust/issues/57571>
   = note: `#[deny(ill_formed_attribute_input)]` (part of `#[deny(future_incompatible)]`) on by default

warning: crate-level attribute should be an inner attribute: add an exclamation mark: `#![crate_name]`
##[warning]  --> /checkout/tests/ui/attributes/malformed-attrs.rs:73:1
   |
LL | #[crate_name]
---
...  |
LL | | }
   | |_^

error: valid forms for the attribute are `#[doc = "string"]`, `#[doc(alias)]`, `#[doc(attribute)]`, `#[doc(auto_cfg)]`, `#[doc(cfg)]`, `#[doc(fake_variadic)]`, `#[doc(hidden)]`, `#[doc(html_favicon_url)]`, `#[doc(html_logo_url)]`, `#[doc(html_no_source)]`, `#[doc(html_playground_url)]`, `#[doc(html_root_url)]`, `#[doc(include)]`, `#[doc(inline)]`, `#[doc(issue_tracker_base_url)]`, `#[doc(keyword)]`, `#[doc(masked)]`, `#[doc(no_default_passes)]`, `#[doc(no_inline)]`, `#[doc(notable_trait)]`, `#[doc(passes)]`, `#[doc(plugins)]`, `#[doc(rust_logo)]`, `#[doc(search_unbox)]`, `#[doc(spotlight)]`, and `#[doc(test)]`
##[error]  --> /checkout/tests/ui/attributes/malformed-attrs.rs:76:1
   |
LL | #[doc]
   | ^^^^^^

---
LL |     #[coroutine = 63] || {}
   |                       ^^^^^ expected `()`, found coroutine
   |
   = note: expected unit type `()`
              found coroutine `{coroutine@/checkout/tests/ui/attributes/malformed-attrs.rs:115:23: 115:25}`

error: aborting due to 73 previous errors; 8 warnings emitted

Some errors have detailed explanations: E0308, E0463, E0539, E0565, E0658, E0805.
For more information about an error, try `rustc --explain E0308`.
---
   | ^^^^^^^^^^^^^
   |
   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
   = note: for more information, see issue #57571 <https://github.com/rust-lang/rust/issues/57571>
   = note: `#[deny(ill_formed_attribute_input)]` (part of `#[deny(future_incompatible)]`) on by default

Future breakage diagnostic:
error: valid forms for the attribute are `#[ignore = "reason"]` and `#[ignore]`
##[error]  --> /checkout/tests/ui/attributes/malformed-attrs.rs:96:1
   |
LL | #[ignore()]
   | ^^^^^^^^^^^
   |
   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
   = note: for more information, see issue #57571 <https://github.com/rust-lang/rust/issues/57571>
   = note: `#[deny(ill_formed_attribute_input)]` (part of `#[deny(future_incompatible)]`) on by default

Future breakage diagnostic:
error: valid forms for the attribute are `#[ignore = "reason"]` and `#[ignore]`
##[error]  --> /checkout/tests/ui/attributes/malformed-attrs.rs:222:1
   |
LL | #[ignore = 1]
   | ^^^^^^^^^^^^^
   |
   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
   = note: for more information, see issue #57571 <https://github.com/rust-lang/rust/issues/57571>
   = note: `#[deny(ill_formed_attribute_input)]` (part of `#[deny(future_incompatible)]`) on by default
------------------------------------------

---- [ui] tests/ui/attributes/malformed-attrs.rs stdout end ----
---- [ui] tests/ui/malformed/malformed-regressions.rs stdout ----
Saved the actual stderr to `/checkout/obj/build/aarch64-unknown-linux-gnu/test/ui/malformed/malformed-regressions/malformed-regressions.stderr`
diff of stderr:

28    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
29    = note: requested on the command line with `-W unused-attributes`
30 
- error: valid forms for the attribute are `#[doc = "string"]`, `#[doc(alias)]`, `#[doc(attribute)]`, `#[doc(auto_cfg)]`, `#[doc(cfg)]`, `#[doc(fake_variadic)]`, `#[doc(hidden)]`, `#[doc(html_favicon_url)]`, `#[doc(html_logo_url)]`, `#[doc(html_no_source)]`, `#[doc(html_playground_url)]`, `#[doc(html_root_url)]`, `#[doc(include)]`, `#[doc(inline)]`, `#[doc(issue_tracker_base_url)]`, `#[doc(keyword)]`, `#[doc(masked)]`, `#[doc(no_default_passes)]`, `#[doc(no_inline)]`, `#[doc(notable_trait)]`, `#[doc(label_trait)]`, `#[doc(passes)]`, `#[doc(plugins)]`, `#[doc(rust_logo)]`, `#[doc(search_unbox)]`, `#[doc(spotlight)]`, and `#[doc(test)]`
+ error: valid forms for the attribute are `#[doc = "string"]`, `#[doc(alias)]`, `#[doc(attribute)]`, `#[doc(auto_cfg)]`, `#[doc(cfg)]`, `#[doc(fake_variadic)]`, `#[doc(hidden)]`, `#[doc(html_favicon_url)]`, `#[doc(html_logo_url)]`, `#[doc(html_no_source)]`, `#[doc(html_playground_url)]`, `#[doc(html_root_url)]`, `#[doc(include)]`, `#[doc(inline)]`, `#[doc(issue_tracker_base_url)]`, `#[doc(keyword)]`, `#[doc(masked)]`, `#[doc(no_default_passes)]`, `#[doc(no_inline)]`, `#[doc(notable_trait)]`, `#[doc(passes)]`, `#[doc(plugins)]`, `#[doc(rust_logo)]`, `#[doc(search_unbox)]`, `#[doc(spotlight)]`, and `#[doc(test)]`
32   --> $DIR/malformed-regressions.rs:3:1
33    |
34 LL | #[doc]


The actual stderr differed from the expected stderr
To update references, rerun the tests and pass the `--bless` flag
To only update this specific test, also pass `--test-args malformed/malformed-regressions.rs`

error: 1 errors occurred comparing output.
status: exit status: 1
command: env -u RUSTC_LOG_COLOR RUSTC_ICE="0" RUST_BACKTRACE="short" "/checkout/obj/build/aarch64-unknown-linux-gnu/stage2/bin/rustc" "/checkout/tests/ui/malformed/malformed-regressions.rs" "-Zthreads=1" "-Zsimulate-remapped-rust-src-base=/rustc/FAKE_PREFIX" "-Ztranslate-remapped-path-to-local-path=no" "-Z" "ignore-directory-in-diagnostics-source-blocks=/cargo" "-Z" "ignore-directory-in-diagnostics-source-blocks=/checkout/vendor" "--sysroot" "/checkout/obj/build/aarch64-unknown-linux-gnu/stage2" "--target=aarch64-unknown-linux-gnu" "--check-cfg" "cfg(test,FALSE)" "--error-format" "json" "--json" "future-incompat" "-Ccodegen-units=1" "-Zui-testing" "-Zdeduplicate-diagnostics=no" "-Zwrite-long-types-to-disk=no" "-Cstrip=debuginfo" "--emit" "metadata" "-C" "prefer-dynamic" "--out-dir" "/checkout/obj/build/aarch64-unknown-linux-gnu/test/ui/malformed/malformed-regressions" "-A" "unused" "-W" "unused_attributes" "-A" "internal_features" "-A" "incomplete_features" "-A" "unused_parens" "-A" "unused_braces" "-Crpath" "-Cdebuginfo=0" "-Lnative=/checkout/obj/build/aarch64-unknown-linux-gnu/native/rust-test-helpers"
stdout: none
--- stderr -------------------------------
error[E0539]: malformed `link` attribute input
##[error]  --> /checkout/tests/ui/malformed/malformed-regressions.rs:8:1
   |
LL | #[link] //~ ERROR malformed
   | ^^^^^^^ expected this to be a list
   |
   = note: for more information, visit <https://doc.rust-lang.org/reference/items/external-blocks.html#the-link-attribute>

error[E0539]: malformed `link` attribute input
##[error]  --> /checkout/tests/ui/malformed/malformed-regressions.rs:11:1
   |
LL | #[link = ""] //~ ERROR malformed
   | ^^^^^^^----^
   |        |
   |        expected this to be a list
   |
   = note: for more information, visit <https://doc.rust-lang.org/reference/items/external-blocks.html#the-link-attribute>

warning: attribute should be applied to an `extern` block with non-Rust ABI
##[warning]  --> /checkout/tests/ui/malformed/malformed-regressions.rs:8:1
   |
LL | #[link] //~ ERROR malformed
   | ^^^^^^^
...
LL | fn main() {}
   | ------------ not an `extern` block
   |
   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
   = note: requested on the command line with `-W unused-attributes`

error: valid forms for the attribute are `#[doc = "string"]`, `#[doc(alias)]`, `#[doc(attribute)]`, `#[doc(auto_cfg)]`, `#[doc(cfg)]`, `#[doc(fake_variadic)]`, `#[doc(hidden)]`, `#[doc(html_favicon_url)]`, `#[doc(html_logo_url)]`, `#[doc(html_no_source)]`, `#[doc(html_playground_url)]`, `#[doc(html_root_url)]`, `#[doc(include)]`, `#[doc(inline)]`, `#[doc(issue_tracker_base_url)]`, `#[doc(keyword)]`, `#[doc(masked)]`, `#[doc(no_default_passes)]`, `#[doc(no_inline)]`, `#[doc(notable_trait)]`, `#[doc(passes)]`, `#[doc(plugins)]`, `#[doc(rust_logo)]`, `#[doc(search_unbox)]`, `#[doc(spotlight)]`, and `#[doc(test)]`
##[error]  --> /checkout/tests/ui/malformed/malformed-regressions.rs:3:1
   |
LL | #[doc] //~ ERROR valid forms for the attribute are
   | ^^^^^^
   |
note: the lint level is defined here
  --> /checkout/tests/ui/malformed/malformed-regressions.rs:1:9
   |
LL | #![deny(invalid_doc_attributes)]
   |         ^^^^^^^^^^^^^^^^^^^^^^

error: valid forms for the attribute are `#[ignore = "reason"]` and `#[ignore]`
##[error]  --> /checkout/tests/ui/malformed/malformed-regressions.rs:4:1
   |
LL | #[ignore()] //~ ERROR valid forms for the attribute are
   | ^^^^^^^^^^^
   |
   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
   = note: for more information, see issue #57571 <https://github.com/rust-lang/rust/issues/57571>
   = note: `#[deny(ill_formed_attribute_input)]` (part of `#[deny(future_incompatible)]`) on by default

error: valid forms for the attribute are `#[inline(always)]`, `#[inline(never)]`, and `#[inline]`
##[error]  --> /checkout/tests/ui/malformed/malformed-regressions.rs:6:1
   |
LL | #[inline = ""] //~ ERROR valid forms for the attribute are
   | ^^^^^^^^^^^^^^
   |
   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
   = note: for more information, see issue #57571 <https://github.com/rust-lang/rust/issues/57571>

error: aborting due to 5 previous errors; 1 warning emitted

For more information about this error, try `rustc --explain E0539`.
Future incompatibility report: Future breakage diagnostic:
error: valid forms for the attribute are `#[ignore = "reason"]` and `#[ignore]`
##[error]  --> /checkout/tests/ui/malformed/malformed-regressions.rs:4:1
   |
LL | #[ignore()] //~ ERROR valid forms for the attribute are
   | ^^^^^^^^^^^
   |
   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
   = note: for more information, see issue #57571 <https://github.com/rust-lang/rust/issues/57571>
   = note: `#[deny(ill_formed_attribute_input)]` (part of `#[deny(future_incompatible)]`) on by default

Future breakage diagnostic:
error: valid forms for the attribute are `#[inline(always)]`, `#[inline(never)]`, and `#[inline]`
##[error]  --> /checkout/tests/ui/malformed/malformed-regressions.rs:6:1
   |
LL | #[inline = ""] //~ ERROR valid forms for the attribute are
   | ^^^^^^^^^^^^^^
   |
   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
   = note: for more information, see issue #57571 <https://github.com/rust-lang/rust/issues/57571>
   = note: `#[deny(ill_formed_attribute_input)]` (part of `#[deny(future_incompatible)]`) on by default
------------------------------------------

---- [ui] tests/ui/malformed/malformed-regressions.rs stdout end ----

failures:

ThierryBerger added 4 commits May 24, 2026 11:44

wip

19beb1c

wip in render html rustdoc

c95ffaa

actually render the label

4843bad

tests for label_traits

fcfb089

rustbot assigned fmease May 28, 2026

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ThierryBerger commented May 28, 2026

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ThierryBerger commented May 28, 2026

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