Rollup merge of rust-lang#76730 - ebkalderon:rustdoc-fix-mut-args-asy…

…nc-fn, r=tmandry

Fix rustdoc rendering of by-value mutable arguments in async fn

r? `@jyn514`

Fixes rust-lang#76517.

compiler/rustc_ast_lowering/src/item.rs

@@ -1096,8 +1096,18 @@ impl<'hir> LoweringContext<'_, 'hir> {
  // Check if this is a binding pattern, if so, we can optimize and avoid adding a
  // `let <pat> = __argN;` statement. In this case, we do not rename the parameter.
  let (ident, is_simple_parameter) = match parameter.pat.kind {
- hir::PatKind::Binding(hir::BindingAnnotation::Unannotated, _, ident, _) => {
- (ident, true)
+ hir::PatKind::Binding(
+ hir::BindingAnnotation::Unannotated | hir::BindingAnnotation::Mutable,
+ _,
+ ident,
+ _,
+ ) => (ident, true),
+ // For `ref mut` or wildcard arguments, we can't reuse the binding, but
+ // we can keep the same name for the parameter.
+ // This lets rustdoc render it correctly in documentation.
+ hir::PatKind::Binding(_, _, ident, _) => (ident, false),
+ hir::PatKind::Wild => {
+ (Ident::with_dummy_span(rustc_span::symbol::kw::Underscore), false)
  }
  _ => {
  // Replace the ident for bindings that aren't simple.

src/test/rustdoc/async-fn.rs

@@ -1,4 +1,5 @@
 // edition:2018
+#![feature(min_const_generics)]
 
 // @has async_fn/fn.foo.html '//pre[@class="rust fn"]' 'pub async fn foo() -> Option<Foo>'
 pub async fn foo() -> Option<Foo> {
@@ -20,6 +21,12 @@ pub async unsafe fn qux() -> char {
  '⚠'
 }
 
+// @has async_fn/fn.mut_args.html '//pre[@class="rust fn"]' 'pub async fn mut_args(a: usize)'
+pub async fn mut_args(mut a: usize) {}
+
+// @has async_fn/fn.mut_ref.html '//pre[@class="rust fn"]' 'pub async fn mut_ref(x: i32)'
+pub async fn mut_ref(ref mut x: i32) {}
+
 trait Bar {}
 
 impl Bar for () {}
@@ -32,9 +39,16 @@ pub async fn quux() -> impl Bar {
 // @has async_fn/struct.Foo.html
 // @matches - '//code' 'pub async fn f\(\)$'
 // @matches - '//code' 'pub async unsafe fn g\(\)$'
+// @matches - '//code' 'pub async fn mut_self\(self, first: usize\)$'
 pub struct Foo;
 
 impl Foo {
  pub async fn f() {}
  pub async unsafe fn g() {}
+ pub async fn mut_self(mut self, mut first: usize) {}
 }
+
+pub trait Trait<const N: usize> {}
+// @has async_fn/fn.const_generics.html
+// @has - '//pre[@class="rust fn"]' 'pub async fn const_generics<const N: usize>(_: impl Trait<N>)'
+pub async fn const_generics<const N: usize>(_: impl Trait<N>) {}