Auto merge of #58824 - euclio:intra-link-ambiguity, r=petrochenkov

overhaul intra-doc-link ambiguity warning

Fixes #52784.

- Makes the warning part of the `intra_doc_link_resolution_failure`
lint.
- Tightens the span to just the ambiguous link.
- Reports ambiguities across all three namespaces.
- Uses structured suggestions for disambiguation.
- Adds a test for the warnings.

r? @QuietMisdreavus

src/test/rustdoc-ui/intra-links-ambiguity.rs

@@ -0,0 +1,36 @@
+#![deny(intra_doc_link_resolution_failure)]
+#![allow(non_camel_case_types)]
+#![allow(non_upper_case_globals)]
+
+pub fn ambiguous() {}
+
+pub struct ambiguous {}
+
+#[macro_export]
+macro_rules! multi_conflict { () => {} }
+
+#[allow(non_camel_case_types)]
+pub struct multi_conflict {}
+
+pub fn multi_conflict() {}
+
+pub mod type_and_value {}
+
+pub const type_and_value: i32 = 0;
+
+pub mod foo {
+    pub enum bar {}
+
+    pub fn bar() {}
+}
+
+/// [`ambiguous`] is ambiguous. //~ERROR `ambiguous`
+///
+/// [ambiguous] is ambiguous. //~ERROR ambiguous
+///
+/// [`multi_conflict`] is a three-way conflict. //~ERROR `multi_conflict`
+///
+/// Ambiguous [type_and_value]. //~ERROR type_and_value
+///
+/// Ambiguous non-implied shortcut link [`foo::bar`]. //~ERROR `foo::bar`
+pub struct Docs {}

src/test/rustdoc-ui/intra-links-ambiguity.stderr

@@ -0,0 +1,82 @@
+error: `ambiguous` is both a struct and a function
+  --> $DIR/intra-links-ambiguity.rs:27:6
+   |
+LL | /// [`ambiguous`] is ambiguous.
+   |      ^^^^^^^^^^^ ambiguous link
+   |
+note: lint level defined here
+  --> $DIR/intra-links-ambiguity.rs:1:9
+   |
+LL | #![deny(intra_doc_link_resolution_failure)]
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+help: to link to the struct, prefix with the item type
+   |
+LL | /// [`struct@ambiguous`] is ambiguous.
+   |      ^^^^^^^^^^^^^^^^^^
+help: to link to the function, add parentheses
+   |
+LL | /// [`ambiguous()`] is ambiguous.
+   |      ^^^^^^^^^^^^^
+
+error: `ambiguous` is both a struct and a function
+  --> $DIR/intra-links-ambiguity.rs:29:6
+   |
+LL | /// [ambiguous] is ambiguous.
+   |      ^^^^^^^^^ ambiguous link
+help: to link to the struct, prefix with the item type
+   |
+LL | /// [struct@ambiguous] is ambiguous.
+   |      ^^^^^^^^^^^^^^^^
+help: to link to the function, add parentheses
+   |
+LL | /// [ambiguous()] is ambiguous.
+   |      ^^^^^^^^^^^
+
+error: `multi_conflict` is a struct, a function, and a macro
+  --> $DIR/intra-links-ambiguity.rs:31:6
+   |
+LL | /// [`multi_conflict`] is a three-way conflict.
+   |      ^^^^^^^^^^^^^^^^ ambiguous link
+help: to link to the struct, prefix with the item type
+   |
+LL | /// [`struct@multi_conflict`] is a three-way conflict.
+   |      ^^^^^^^^^^^^^^^^^^^^^^^
+help: to link to the function, add parentheses
+   |
+LL | /// [`multi_conflict()`] is a three-way conflict.
+   |      ^^^^^^^^^^^^^^^^^^
+help: to link to the macro, add an exclamation mark
+   |
+LL | /// [`multi_conflict!`] is a three-way conflict.
+   |      ^^^^^^^^^^^^^^^^^
+
+error: `type_and_value` is both a module and a constant
+  --> $DIR/intra-links-ambiguity.rs:33:16
+   |
+LL | /// Ambiguous [type_and_value].
+   |                ^^^^^^^^^^^^^^ ambiguous link
+help: to link to the module, prefix with the item type
+   |
+LL | /// Ambiguous [module@type_and_value].
+   |                ^^^^^^^^^^^^^^^^^^^^^
+help: to link to the constant, prefix with the item type
+   |
+LL | /// Ambiguous [const@type_and_value].
+   |                ^^^^^^^^^^^^^^^^^^^^
+
+error: `foo::bar` is both an enum and a function
+  --> $DIR/intra-links-ambiguity.rs:35:42
+   |
+LL | /// Ambiguous non-implied shortcut link [`foo::bar`].
+   |                                          ^^^^^^^^^^ ambiguous link
+help: to link to the enum, prefix with the item type
+   |
+LL | /// Ambiguous non-implied shortcut link [`enum@foo::bar`].
+   |                                          ^^^^^^^^^^^^^^^
+help: to link to the function, add parentheses
+   |
+LL | /// Ambiguous non-implied shortcut link [`foo::bar()`].
+   |                                          ^^^^^^^^^^^^
+
+error: aborting due to 5 previous errors
+

src/test/rustdoc/intra-links.rs

@@ -22,6 +22,7 @@
 //! * [`ThisType::this_method`](ThisType::this_method)
 //! * [`ThisEnum`](ThisEnum)
 //! * [`ThisEnum::ThisVariant`](ThisEnum::ThisVariant)
+//! * [`ThisEnum::ThisVariantCtor`](ThisEnum::ThisVariantCtor)
 //! * [`ThisTrait`](ThisTrait)
 //! * [`ThisTrait::this_associated_method`](ThisTrait::this_associated_method)
 //! * [`ThisTrait::ThisAssociatedType`](ThisTrait::ThisAssociatedType)
@@ -50,7 +51,7 @@ pub struct ThisType;
 impl ThisType {
     pub fn this_method() {}
 }
-pub enum ThisEnum { ThisVariant, }
+pub enum ThisEnum { ThisVariant, ThisVariantCtor(u32), }
 pub trait ThisTrait {
     type ThisAssociatedType;
     const THIS_ASSOCIATED_CONST: u8;