Rollup merge of #141746 - Urgau:rework-doc_cfg-checks, r=GuillaumeGomez

Rework `#[doc(cfg(..))]` checks as distinct pass in rustdoc

This PR reworks how rustdoc calls `rustc_attr_parsing::cfg_matches` to be in a separate pass, instead of being wired-up in a ad-hoc way, which is causing problems in https://github.com/rust-lang/rust/pull/138907#issuecomment-2920026627.

This un-does most part of https://github.com/rust-lang/rust/pull/140894, but the result is IMO much cleaner, easier to reason about, and most importantly no longer interfears with rust-lang/rust#138907.

r? `@GuillaumeGomez`

4 files changed, 39 insertions, 15 deletions

diff --git a/tests/rustdoc-ui/doc-cfg-check-cfg.cfg_empty.stderr b/tests/rustdoc-ui/doc-cfg-check-cfg.cfg_empty.stderr
index 7e6f8dec5ed..0878f7edbf4 100644
--- a/tests/rustdoc-ui/doc-cfg-check-cfg.cfg_empty.stderr
+++ b/tests/rustdoc-ui/doc-cfg-check-cfg.cfg_empty.stderr
@@ -1,12 +1,30 @@
 warning: unexpected `cfg` condition name: `foo`
-  --> $DIR/doc-cfg-check-cfg.rs:13:11
+  --> $DIR/doc-cfg-check-cfg.rs:12:12
+   |
+LL | #![doc(cfg(foo))]
+   |            ^^^
+   |
+   = help: to expect this configuration use `--check-cfg=cfg(foo)`
+   = note: see <https://doc.rust-lang.org/nightly/rustc/check-cfg.html> for more information about checking conditional configuration
+   = note: `#[warn(unexpected_cfgs)]` on by default
+
+warning: unexpected `cfg` condition name: `foo`
+  --> $DIR/doc-cfg-check-cfg.rs:19:11
+   |
+LL | #[doc(cfg(foo))]
+   |           ^^^
+   |
+   = help: to expect this configuration use `--check-cfg=cfg(foo)`
+   = note: see <https://doc.rust-lang.org/nightly/rustc/check-cfg.html> for more information about checking conditional configuration
+
+warning: unexpected `cfg` condition name: `foo`
+  --> $DIR/doc-cfg-check-cfg.rs:15:11
    |
 LL | #[doc(cfg(foo))]
    |           ^^^
    |
    = help: to expect this configuration use `--check-cfg=cfg(foo)`
    = note: see <https://doc.rust-lang.org/nightly/rustc/check-cfg.html> for more information about checking conditional configuration
-   = note: `#[warn(unexpected_cfgs)]` on by default
 
-warning: 1 warning emitted
+warning: 3 warnings emitted
 
diff --git a/tests/rustdoc-ui/doc-cfg-check-cfg.rs b/tests/rustdoc-ui/doc-cfg-check-cfg.rs
index 6bb520b0726..7d37077a32d 100644
--- a/tests/rustdoc-ui/doc-cfg-check-cfg.rs
+++ b/tests/rustdoc-ui/doc-cfg-check-cfg.rs
@@ -9,11 +9,15 @@
 //@[cfg_foo] compile-flags: --check-cfg cfg(foo)
 
 #![feature(doc_cfg)]
+#![doc(cfg(foo))]
+//[cfg_empty]~^ WARN unexpected `cfg` condition name: `foo`
 
 #[doc(cfg(foo))]
 //[cfg_empty]~^ WARN unexpected `cfg` condition name: `foo`
 pub fn foo() {}
 
+#[doc(cfg(foo))]
+//[cfg_empty]~^ WARN unexpected `cfg` condition name: `foo`
 pub mod module {
     #[allow(unexpected_cfgs)]
     #[doc(cfg(bar))]
diff --git a/tests/rustdoc-ui/doc-cfg.stderr b/tests/rustdoc-ui/doc-cfg.stderr
index 48c8e79ce96..1233ee010de 100644
--- a/tests/rustdoc-ui/doc-cfg.stderr
+++ b/tests/rustdoc-ui/doc-cfg.stderr
@@ -10,6 +10,18 @@ error: multiple `cfg` predicates are specified
 LL | #[doc(cfg(), cfg(foo, bar))]
    |                       ^^^
 
+error: `cfg` predicate is not specified
+  --> $DIR/doc-cfg.rs:9:7
+   |
+LL | #[doc(cfg())]
+   |       ^^^^^ help: expected syntax is: `cfg(/* predicate */)`
+
+error: multiple `cfg` predicates are specified
+  --> $DIR/doc-cfg.rs:10:16
+   |
+LL | #[doc(cfg(foo, bar))]
+   |                ^^^
+
 warning: unexpected `cfg` condition name: `foo`
   --> $DIR/doc-cfg.rs:6:11
    |
@@ -30,17 +42,5 @@ LL | #[doc(cfg(foo), cfg(bar))]
    = help: to expect this configuration use `--check-cfg=cfg(bar)`
    = note: see <https://doc.rust-lang.org/nightly/rustc/check-cfg.html> for more information about checking conditional configuration
 
-error: `cfg` predicate is not specified
-  --> $DIR/doc-cfg.rs:9:7
-   |
-LL | #[doc(cfg())]
-   |       ^^^^^ help: expected syntax is: `cfg(/* predicate */)`
-
-error: multiple `cfg` predicates are specified
-  --> $DIR/doc-cfg.rs:10:16
-   |
-LL | #[doc(cfg(foo, bar))]
-   |                ^^^
-
 error: aborting due to 4 previous errors; 2 warnings emitted
 
diff --git a/tests/rustdoc-ui/issues/issue-91713.stdout b/tests/rustdoc-ui/issues/issue-91713.stdout
index 790e58b0df9..30aadfe89f4 100644
--- a/tests/rustdoc-ui/issues/issue-91713.stdout
+++ b/tests/rustdoc-ui/issues/issue-91713.stdout
@@ -1,4 +1,5 @@
 Available passes for running rustdoc:
+       check-doc-cfg - checks `#[doc(cfg(...))]` for stability feature and unexpected cfgs
 check_doc_test_visibility - run various visibility-related lints on doctests
 strip-aliased-non-local - strips all non-local private aliased items from the output
         strip-hidden - strips all `#[doc(hidden)]` items from the output
@@ -14,6 +15,7 @@ calculate-doc-coverage - counts the number of items with and without documentati
 Default passes for rustdoc:
  collect-trait-impls
 check_doc_test_visibility
+       check-doc-cfg
 strip-aliased-non-local
         strip-hidden  (when not --document-hidden-items)
        strip-private  (when not --document-private-items)