Don't process [] and () in intra-doc links

These caused several false positives when documenting rustc, which means
there will likely be many more false positives in the rest of the
ecosystem.

src/librustdoc/passes/collect_intra_doc_links.rs

@@ -1020,7 +1020,7 @@ impl LinkCollector<'_, '_> {
             (link.trim(), None)
         };
 
-        if path_str.contains(|ch: char| !(ch.is_alphanumeric() || ":_<>, !*()[]&;".contains(ch))) {
+        if path_str.contains(|ch: char| !(ch.is_alphanumeric() || ":_<>, !*&;".contains(ch))) {
             return None;
         }
 
@@ -2085,10 +2085,11 @@ fn resolve_primitive(path_str: &str, ns: Namespace) -> Option<Res> {
         "char" => Char,
         "bool" | "true" | "false" => Bool,
         "str" => Str,
-        "slice" | "&[]" | "[T]" => Slice,
-        "array" | "[]" | "[T;N]" => Array,
-        "tuple" | "(,)" => Tuple,
-        "unit" | "()" => Unit,
+        // See #80181 for why these don't have symbols associated.
+        "slice" => Slice,
+        "array" => Array,
+        "tuple" => Tuple,
+        "unit" => Unit,
         "pointer" | "*" | "*const" | "*mut" => RawPointer,
         "reference" | "&" | "&mut" => Reference,
         "fn" => Fn,

src/test/rustdoc-ui/intra-doc/non-path-primitives.rs

@@ -0,0 +1,34 @@
+#![deny(broken_intra_doc_links)]
+// These are links that could reasonably expected to work, but don't.
+
+// `[]` isn't supported because it had too many false positives.
+//! [X]([T]::not_here)
+//! [Y](&[]::not_here)
+//! [X]([]::not_here)
+//! [Y]([T;N]::not_here)
+
+// These don't work because markdown syntax doesn't allow it.
+//! [[T]::rotate_left] //~ ERROR unresolved link to `T`
+//! [&[]::not_here]
+//![Z]([T; N]::map) //~ ERROR unresolved link to `Z`
+//! [`[T; N]::map`]
+//! [[]::map]
+//! [Z][] //~ ERROR unresolved link to `Z`
+//!
+//! [Z]: [T; N]::map //~ ERROR unresolved link to `Z`
+
+// `()` isn't supported because it had too many false positives.
+//! [()::not_here]
+//! [X]((,)::not_here)
+//! [(,)::not_here]
+
+// FIXME: Associated items on some primitives aren't working, because the impls
+// are part of the compiler instead of being part of the source code.
+//! [unit::eq] //~ ERROR unresolved
+//! [tuple::eq] //~ ERROR unresolved
+//! [fn::eq] //~ ERROR unresolved
+//! [never::eq] //~ ERROR unresolved
+
+// FIXME(#78800): This breaks because it's a blanket impl
+// (I think? Might break for other reasons too.)
+//! [reference::deref] //~ ERROR unresolved

src/test/rustdoc-ui/intra-doc/non-path-primitives.stderr

@@ -0,0 +1,69 @@
+error: unresolved link to `T`
+  --> $DIR/non-path-primitives.rs:11:7
+   |
+LL | //! [[T]::rotate_left]
+   |       ^ no item named `T` in scope
+   |
+note: the lint level is defined here
+  --> $DIR/non-path-primitives.rs:1:9
+   |
+LL | #![deny(broken_intra_doc_links)]
+   |         ^^^^^^^^^^^^^^^^^^^^^^
+   = help: to escape `[` and `]` characters, add '\' before them like `\[` or `\]`
+
+error: unresolved link to `Z`
+  --> $DIR/non-path-primitives.rs:13:5
+   |
+LL | //![Z]([T; N]::map)
+   |     ^ no item named `Z` in scope
+   |
+   = help: to escape `[` and `]` characters, add '\' before them like `\[` or `\]`
+
+error: unresolved link to `Z`
+  --> $DIR/non-path-primitives.rs:16:6
+   |
+LL | //! [Z][]
+   |      ^ no item named `Z` in scope
+   |
+   = help: to escape `[` and `]` characters, add '\' before them like `\[` or `\]`
+
+error: unresolved link to `Z`
+  --> $DIR/non-path-primitives.rs:18:6
+   |
+LL | //! [Z]: [T; N]::map
+   |      ^ no item named `Z` in scope
+   |
+   = help: to escape `[` and `]` characters, add '\' before them like `\[` or `\]`
+
+error: unresolved link to `unit::eq`
+  --> $DIR/non-path-primitives.rs:27:6
+   |
+LL | //! [unit::eq]
+   |      ^^^^^^^^ the builtin type `unit` has no associated item named `eq`
+
+error: unresolved link to `tuple::eq`
+  --> $DIR/non-path-primitives.rs:28:6
+   |
+LL | //! [tuple::eq]
+   |      ^^^^^^^^^ the builtin type `tuple` has no associated item named `eq`
+
+error: unresolved link to `fn::eq`
+  --> $DIR/non-path-primitives.rs:29:6
+   |
+LL | //! [fn::eq]
+   |      ^^^^^^ the builtin type `fn` has no associated item named `eq`
+
+error: unresolved link to `never::eq`
+  --> $DIR/non-path-primitives.rs:30:6
+   |
+LL | //! [never::eq]
+   |      ^^^^^^^^^ the builtin type `never` has no associated item named `eq`
+
+error: unresolved link to `reference::deref`
+  --> $DIR/non-path-primitives.rs:34:6
+   |
+LL | //! [reference::deref]
+   |      ^^^^^^^^^^^^^^^^ the builtin type `reference` has no associated item named `deref`
+
+error: aborting due to 9 previous errors
+

src/test/rustdoc/intra-doc/non-path-primitives.rs

@@ -3,28 +3,10 @@
 #![deny(broken_intra_doc_links)]
 
 // @has foo/index.html '//a[@href="https://doc.rust-lang.org/nightly/std/primitive.slice.html#method.rotate_left"]' 'slice::rotate_left'
-// @has - '//a[@href="https://doc.rust-lang.org/nightly/std/primitive.slice.html#method.rotate_left"]' 'X'
-// @has - '//a[@href="https://doc.rust-lang.org/nightly/std/primitive.slice.html#method.rotate_left"]' 'Y'
 //! [slice::rotate_left]
-//! [X]([T]::rotate_left)
-//! [Y](&[]::rotate_left)
-// These don't work because markdown syntax doesn't allow it.
-// [[T]::rotate_left]
-//! [&[]::rotate_left]
 
 // @has - '//a[@href="https://doc.rust-lang.org/nightly/std/primitive.array.html#method.map"]' 'array::map'
-// @has - '//a[@href="https://doc.rust-lang.org/nightly/std/primitive.array.html#method.map"]' 'X'
-// @has - '//a[@href="https://doc.rust-lang.org/nightly/std/primitive.array.html#method.map"]' 'Y'
 //! [array::map]
-//! [X]([]::map)
-//! [Y]([T;N]::map)
-// These don't work because markdown syntax doesn't allow it.
-// [Z]([T; N]::map)
-//! [`[T; N]::map`]
-//! [[]::map]
-// [Z][]
-//
-// [Z]: [T; N]::map
 
 // @has - '//a[@href="https://doc.rust-lang.org/nightly/std/primitive.pointer.html#method.is_null"]' 'pointer::is_null'
 // @has - '//a[@href="https://doc.rust-lang.org/nightly/std/primitive.pointer.html#method.is_null"]' '*const::is_null'
@@ -35,20 +17,11 @@
 //! [*mut::is_null]
 //! [*::is_null]
 
-// FIXME: Associated items on some primitives aren't working, because the impls
-// are part of the compiler instead of being part of the source code.
-
 // @has - '//a[@href="https://doc.rust-lang.org/nightly/std/primitive.unit.html"]' 'unit'
-// @has - '//a[@href="https://doc.rust-lang.org/nightly/std/primitive.unit.html"]' '()'
 //! [unit]
-//! [()]
 
 // @has - '//a[@href="https://doc.rust-lang.org/nightly/std/primitive.tuple.html"]' 'tuple'
-// @has - '//a[@href="https://doc.rust-lang.org/nightly/std/primitive.tuple.html"]' 'X'
-// @has - '//a[@href="https://doc.rust-lang.org/nightly/std/primitive.tuple.html"]' '(,)'
 //! [tuple]
-//! [X]((,))
-//! [(,)]
 
 // @has - '//a[@href="https://doc.rust-lang.org/nightly/std/primitive.reference.html"]' 'reference'
 // @has - '//a[@href="https://doc.rust-lang.org/nightly/std/primitive.reference.html"]' '&'