Auto merge of #113958 - lukas-code:doc-links, r=GuillaumeGomez,petrochenkov

fix intra-doc links on nested `use` and `extern crate` items

This PR fixes two rustdoc ICEs that happen if there are any intra-doc links on nested `use` or `extern crate` items, for example:
```rust
/// Re-export [`fmt`] and [`io`].
pub use std::{fmt, io}; // "nested" use = use with braces

/// Re-export [`std`].
pub extern crate std;
```

Nested use items were incorrectly considered private and therefore didn't have their intra-doc links resolved. I fixed this by always resolving intra-doc links for nested `use` items that are declared `pub`.

<details>

During AST->HIR lowering, nested `use` items are desugared like this:
```rust
pub use std::{}; // "list stem"
pub use std::fmt;
pub use std::io;
```
Each of these HIR nodes has it's own effective visibility and the list stem is always considered private.
To check the effective visibility of an AST node, the AST node is mapped to a HIR node with `Resolver::local_def_id`, which returns the (private) list stem for nested use items.

</details>

For `extern crate`, there was a hack in rustdoc that stored the `DefId` of the crate itself in the cleaned item, instead of the `DefId` of the `extern crate` item. This made rustdoc look at the resolved links of the extern crate's crate root instead of the `extern crate` item. I've removed this hack and instead translate the `DefId` in the appropriate places.

As as side effect of fixing `extern crate`, i've turned
```rust
#[doc(masked)]
extern crate self as _;
```
into a no-op instead of hiding all trait impls. Proper verification for `doc(masked)` is included as a bonus.

fixes https://github.com/rust-lang/rust/issues/113896

8 files changed, 121 insertions, 121 deletions

diff --git a/tests/rustdoc-ui/intra-doc/broken-link-in-unused-doc-string.rs b/tests/rustdoc-ui/intra-doc/broken-link-in-unused-doc-string.rs
new file mode 100644
index 00000000000..f3f044f6105
--- /dev/null
+++ b/tests/rustdoc-ui/intra-doc/broken-link-in-unused-doc-string.rs
@@ -0,0 +1,16 @@
+// Test that we don't ICE with broken links that don't show up in the docs.
+
+// check-pass
+// edition: 2021
+
+/// [1]
+//~^ WARN unresolved link to `1`
+//~| WARN unresolved link to `1`
+pub use {std, core};
+
+/// [2]
+pub use {};
+
+/// [3]
+//~^ WARN unresolved link to `3`
+pub extern crate alloc;
diff --git a/tests/rustdoc-ui/intra-doc/broken-link-in-unused-doc-string.stderr b/tests/rustdoc-ui/intra-doc/broken-link-in-unused-doc-string.stderr
new file mode 100644
index 00000000000..83e0d3962ca
--- /dev/null
+++ b/tests/rustdoc-ui/intra-doc/broken-link-in-unused-doc-string.stderr
@@ -0,0 +1,27 @@
+warning: unresolved link to `3`
+  --> $DIR/broken-link-in-unused-doc-string.rs:14:6
+   |
+LL | /// [3]
+   |      ^ no item named `3` in scope
+   |
+   = help: to escape `[` and `]` characters, add '\' before them like `\[` or `\]`
+   = note: `#[warn(rustdoc::broken_intra_doc_links)]` on by default
+
+warning: unresolved link to `1`
+  --> $DIR/broken-link-in-unused-doc-string.rs:6:6
+   |
+LL | /// [1]
+   |      ^ no item named `1` in scope
+   |
+   = help: to escape `[` and `]` characters, add '\' before them like `\[` or `\]`
+
+warning: unresolved link to `1`
+  --> $DIR/broken-link-in-unused-doc-string.rs:6:6
+   |
+LL | /// [1]
+   |      ^ no item named `1` in scope
+   |
+   = help: to escape `[` and `]` characters, add '\' before them like `\[` or `\]`
+
+warning: 3 warnings emitted
+
diff --git a/tests/rustdoc-ui/lints/invalid-doc-attr.rs b/tests/rustdoc-ui/lints/invalid-doc-attr.rs
index c231e43b35c..16b12cca5a0 100644
--- a/tests/rustdoc-ui/lints/invalid-doc-attr.rs
+++ b/tests/rustdoc-ui/lints/invalid-doc-attr.rs
@@ -1,5 +1,10 @@
 #![crate_type = "lib"]
 #![deny(warnings)]
+#![feature(doc_masked)]
+
+#![doc(masked)]
+//~^ ERROR this attribute can only be applied to an `extern crate` item
+//~| WARN is being phased out
 
 #[doc(test(no_crate_inject))]
 //~^ ERROR can only be applied at the crate level
@@ -30,3 +35,13 @@ pub mod bar {
 //~^^ ERROR conflicting doc inlining attributes
 //~|  HELP remove one of the conflicting attributes
 pub use bar::baz;
+
+#[doc(masked)]
+//~^ ERROR this attribute can only be applied to an `extern crate` item
+//~| WARN is being phased out
+pub struct Masked;
+
+#[doc(masked)]
+//~^ ERROR this attribute cannot be applied to an `extern crate self` item
+//~| WARN is being phased out
+pub extern crate self as reexport;
diff --git a/tests/rustdoc-ui/lints/invalid-doc-attr.stderr b/tests/rustdoc-ui/lints/invalid-doc-attr.stderr
index b23b8ded867..82ea33e1d89 100644
--- a/tests/rustdoc-ui/lints/invalid-doc-attr.stderr
+++ b/tests/rustdoc-ui/lints/invalid-doc-attr.stderr
@@ -1,5 +1,5 @@
 error: this attribute can only be applied at the crate level
-  --> $DIR/invalid-doc-attr.rs:4:7
+  --> $DIR/invalid-doc-attr.rs:9:7
    |
 LL | #[doc(test(no_crate_inject))]
    |       ^^^^^^^^^^^^^^^^^^^^^
@@ -19,7 +19,7 @@ LL | #![doc(test(no_crate_inject))]
    |  +
 
 error: this attribute can only be applied to a `use` item
-  --> $DIR/invalid-doc-attr.rs:9:7
+  --> $DIR/invalid-doc-attr.rs:14:7
    |
 LL | #[doc(inline)]
    |       ^^^^^^ only applicable on `use` items
@@ -32,7 +32,7 @@ LL | pub fn foo() {}
    = note: read <https://doc.rust-lang.org/nightly/rustdoc/the-doc-attribute.html#inline-and-no_inline> for more information
 
 error: this attribute can only be applied at the crate level
-  --> $DIR/invalid-doc-attr.rs:15:12
+  --> $DIR/invalid-doc-attr.rs:20:12
    |
 LL |     #![doc(test(no_crate_inject))]
    |            ^^^^^^^^^^^^^^^^^^^^^
@@ -42,7 +42,7 @@ LL |     #![doc(test(no_crate_inject))]
    = note: read <https://doc.rust-lang.org/nightly/rustdoc/the-doc-attribute.html#at-the-crate-level> for more information
 
 error: conflicting doc inlining attributes
-  --> $DIR/invalid-doc-attr.rs:28:7
+  --> $DIR/invalid-doc-attr.rs:33:7
    |
 LL | #[doc(inline)]
    |       ^^^^^^ this attribute...
@@ -51,8 +51,43 @@ LL | #[doc(no_inline)]
    |
    = help: remove one of the conflicting attributes
 
+error: this attribute can only be applied to an `extern crate` item
+  --> $DIR/invalid-doc-attr.rs:39:7
+   |
+LL | #[doc(masked)]
+   |       ^^^^^^ only applicable on `extern crate` items
+...
+LL | pub struct Masked;
+   | ----------------- not an `extern crate` item
+   |
+   = 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 #82730 <https://github.com/rust-lang/rust/issues/82730>
+   = note: read <https://doc.rust-lang.org/unstable-book/language-features/doc-masked.html> for more information
+
+error: this attribute cannot be applied to an `extern crate self` item
+  --> $DIR/invalid-doc-attr.rs:44:7
+   |
+LL | #[doc(masked)]
+   |       ^^^^^^ not applicable on `extern crate self` items
+...
+LL | pub extern crate self as reexport;
+   | --------------------------------- `extern crate self` defined here
+   |
+   = 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 #82730 <https://github.com/rust-lang/rust/issues/82730>
+
+error: this attribute can only be applied to an `extern crate` item
+  --> $DIR/invalid-doc-attr.rs:5:8
+   |
+LL | #![doc(masked)]
+   |        ^^^^^^ only applicable on `extern crate` items
+   |
+   = 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 #82730 <https://github.com/rust-lang/rust/issues/82730>
+   = note: read <https://doc.rust-lang.org/unstable-book/language-features/doc-masked.html> for more information
+
 error: this attribute can only be applied at the crate level
-  --> $DIR/invalid-doc-attr.rs:19:11
+  --> $DIR/invalid-doc-attr.rs:24:11
    |
 LL |     #[doc(test(no_crate_inject))]
    |           ^^^^^^^^^^^^^^^^^^^^^
@@ -62,7 +97,7 @@ LL |     #[doc(test(no_crate_inject))]
    = note: read <https://doc.rust-lang.org/nightly/rustdoc/the-doc-attribute.html#at-the-crate-level> for more information
 
 error: this attribute can only be applied to a `use` item
-  --> $DIR/invalid-doc-attr.rs:22:11
+  --> $DIR/invalid-doc-attr.rs:27:11
    |
 LL |     #[doc(inline)]
    |           ^^^^^^ only applicable on `use` items
@@ -74,5 +109,5 @@ LL |     pub fn baz() {}
    = note: for more information, see issue #82730 <https://github.com/rust-lang/rust/issues/82730>
    = note: read <https://doc.rust-lang.org/nightly/rustdoc/the-doc-attribute.html#inline-and-no_inline> for more information
 
-error: aborting due to 6 previous errors
+error: aborting due to 9 previous errors
 
diff --git a/tests/rustdoc/intra-doc/nested-use.rs b/tests/rustdoc/intra-doc/nested-use.rs
new file mode 100644
index 00000000000..19ebfff1bce
--- /dev/null
+++ b/tests/rustdoc/intra-doc/nested-use.rs
@@ -0,0 +1,16 @@
+// Regression test for issue #113896: Intra-doc links on nested use items.
+
+#![crate_name = "foo"]
+
+// @has foo/struct.Foo.html
+// @has - '//a[@href="struct.Foo.html"]' 'Foo'
+// @has - '//a[@href="struct.Bar.html"]' 'Bar'
+
+/// [`Foo`]
+pub use m::{Foo, Bar};
+
+mod m {
+    /// [`Bar`]
+    pub struct Foo;
+    pub struct Bar;
+}
diff --git a/tests/rustdoc/issue-33178.rs b/tests/rustdoc/issue-33178.rs
index 1f45fe72391..ed643f5ae11 100644
--- a/tests/rustdoc/issue-33178.rs
+++ b/tests/rustdoc/issue-33178.rs
@@ -4,10 +4,11 @@
 // ignore-cross-compile
 
 // @has issue_33178/index.html
-// @has - //a/@title empty
-// @has - //a/@href ../empty/index.html
+// @has - '//a[@title="mod empty"][@href="../empty/index.html"]' empty
 pub extern crate empty;
 
-// @has - //a/@title variant_struct
-// @has - //a/@href ../variant_struct/index.html
+// @has - '//a[@title="mod variant_struct"][@href="../variant_struct/index.html"]' variant_struct
 pub extern crate variant_struct as foo;
+
+// @has - '//a[@title="mod issue_33178"][@href="index.html"]' self
+pub extern crate self as bar;
diff --git a/tests/ui/attributes/invalid-doc-attr.rs b/tests/ui/attributes/invalid-doc-attr.rs
deleted file mode 100644
index c231e43b35c..00000000000
--- a/tests/ui/attributes/invalid-doc-attr.rs
+++ /dev/null
@@ -1,32 +0,0 @@
-#![crate_type = "lib"]
-#![deny(warnings)]
-
-#[doc(test(no_crate_inject))]
-//~^ ERROR can only be applied at the crate level
-//~| WARN is being phased out
-//~| HELP to apply to the crate, use an inner attribute
-//~| SUGGESTION !
-#[doc(inline)]
-//~^ ERROR can only be applied to a `use` item
-//~| WARN is being phased out
-pub fn foo() {}
-
-pub mod bar {
-    #![doc(test(no_crate_inject))]
-    //~^ ERROR can only be applied at the crate level
-    //~| WARN is being phased out
-
-    #[doc(test(no_crate_inject))]
-    //~^ ERROR can only be applied at the crate level
-    //~| WARN is being phased out
-    #[doc(inline)]
-    //~^ ERROR can only be applied to a `use` item
-    //~| WARN is being phased out
-    pub fn baz() {}
-}
-
-#[doc(inline)]
-#[doc(no_inline)]
-//~^^ ERROR conflicting doc inlining attributes
-//~|  HELP remove one of the conflicting attributes
-pub use bar::baz;
diff --git a/tests/ui/attributes/invalid-doc-attr.stderr b/tests/ui/attributes/invalid-doc-attr.stderr
deleted file mode 100644
index b23b8ded867..00000000000
--- a/tests/ui/attributes/invalid-doc-attr.stderr
+++ /dev/null
@@ -1,78 +0,0 @@
-error: this attribute can only be applied at the crate level
-  --> $DIR/invalid-doc-attr.rs:4:7
-   |
-LL | #[doc(test(no_crate_inject))]
-   |       ^^^^^^^^^^^^^^^^^^^^^
-   |
-   = 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 #82730 <https://github.com/rust-lang/rust/issues/82730>
-   = note: read <https://doc.rust-lang.org/nightly/rustdoc/the-doc-attribute.html#at-the-crate-level> for more information
-note: the lint level is defined here
-  --> $DIR/invalid-doc-attr.rs:2:9
-   |
-LL | #![deny(warnings)]
-   |         ^^^^^^^^
-   = note: `#[deny(invalid_doc_attributes)]` implied by `#[deny(warnings)]`
-help: to apply to the crate, use an inner attribute
-   |
-LL | #![doc(test(no_crate_inject))]
-   |  +
-
-error: this attribute can only be applied to a `use` item
-  --> $DIR/invalid-doc-attr.rs:9:7
-   |
-LL | #[doc(inline)]
-   |       ^^^^^^ only applicable on `use` items
-...
-LL | pub fn foo() {}
-   | ------------ not a `use` item
-   |
-   = 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 #82730 <https://github.com/rust-lang/rust/issues/82730>
-   = note: read <https://doc.rust-lang.org/nightly/rustdoc/the-doc-attribute.html#inline-and-no_inline> for more information
-
-error: this attribute can only be applied at the crate level
-  --> $DIR/invalid-doc-attr.rs:15:12
-   |
-LL |     #![doc(test(no_crate_inject))]
-   |            ^^^^^^^^^^^^^^^^^^^^^
-   |
-   = 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 #82730 <https://github.com/rust-lang/rust/issues/82730>
-   = note: read <https://doc.rust-lang.org/nightly/rustdoc/the-doc-attribute.html#at-the-crate-level> for more information
-
-error: conflicting doc inlining attributes
-  --> $DIR/invalid-doc-attr.rs:28:7
-   |
-LL | #[doc(inline)]
-   |       ^^^^^^ this attribute...
-LL | #[doc(no_inline)]
-   |       ^^^^^^^^^ ...conflicts with this attribute
-   |
-   = help: remove one of the conflicting attributes
-
-error: this attribute can only be applied at the crate level
-  --> $DIR/invalid-doc-attr.rs:19:11
-   |
-LL |     #[doc(test(no_crate_inject))]
-   |           ^^^^^^^^^^^^^^^^^^^^^
-   |
-   = 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 #82730 <https://github.com/rust-lang/rust/issues/82730>
-   = note: read <https://doc.rust-lang.org/nightly/rustdoc/the-doc-attribute.html#at-the-crate-level> for more information
-
-error: this attribute can only be applied to a `use` item
-  --> $DIR/invalid-doc-attr.rs:22:11
-   |
-LL |     #[doc(inline)]
-   |           ^^^^^^ only applicable on `use` items
-...
-LL |     pub fn baz() {}
-   |     ------------ not a `use` item
-   |
-   = 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 #82730 <https://github.com/rust-lang/rust/issues/82730>
-   = note: read <https://doc.rust-lang.org/nightly/rustdoc/the-doc-attribute.html#inline-and-no_inline> for more information
-
-error: aborting due to 6 previous errors
-