Auto merge of #146698 - Zalathar:rollup-0oxl4gx, r=Zalathar

Rollup of 5 pull requests

Successful merges:

 - rust-lang/rust#146566 (Lint more overlapping assignments in MIR.)
 - rust-lang/rust#146645 (Cleanup `FnDecl::inner_full_print`)
 - rust-lang/rust#146664 (Clean up `ty::Dynamic`)
 - rust-lang/rust#146673 (cg_llvm: Replace some DIBuilder wrappers with LLVM-C API bindings (part 4))
 - rust-lang/rust#146694 (Remove ImplSubject)

r? `@ghost`
`@rustbot` modify labels: rollup

6 files changed, 71 insertions, 60 deletions

diff --git a/src/librustdoc/clean/mod.rs b/src/librustdoc/clean/mod.rs
index 5ccacafea01..0afb969d5c8 100644
--- a/src/librustdoc/clean/mod.rs
+++ b/src/librustdoc/clean/mod.rs
@@ -2093,7 +2093,7 @@ pub(crate) fn clean_middle_ty<'tcx>(
             );
             Type::Path { path }
         }
-        ty::Dynamic(obj, reg, _) => {
+        ty::Dynamic(obj, reg) => {
             // HACK: pick the first `did` as the `did` of the trait object. Someone
             // might want to implement "native" support for marker-trait-only
             // trait objects.
diff --git a/src/librustdoc/display.rs b/src/librustdoc/display.rs
index aa0fad26520..db868c5c9a8 100644
--- a/src/librustdoc/display.rs
+++ b/src/librustdoc/display.rs
@@ -10,7 +10,7 @@ pub(crate) trait Joined: IntoIterator {
     ///
     /// The performance of `joined` is slightly better than `format`, since it doesn't need to use a `Cell` to keep track of whether [`fmt`](Display::fmt)
     /// was already called (`joined`'s API doesn't allow it be called more than once).
-    fn joined(self, sep: &str, f: &mut Formatter<'_>) -> fmt::Result;
+    fn joined(self, sep: impl Display, f: &mut Formatter<'_>) -> fmt::Result;
 }
 
 impl<I, T> Joined for I
@@ -18,12 +18,12 @@ where
     I: IntoIterator<Item = T>,
     T: Display,
 {
-    fn joined(self, sep: &str, f: &mut Formatter<'_>) -> fmt::Result {
+    fn joined(self, sep: impl Display, f: &mut Formatter<'_>) -> fmt::Result {
         let mut iter = self.into_iter();
         let Some(first) = iter.next() else { return Ok(()) };
         first.fmt(f)?;
         for item in iter {
-            f.write_str(sep)?;
+            sep.fmt(f)?;
             item.fmt(f)?;
         }
         Ok(())
diff --git a/src/librustdoc/html/format.rs b/src/librustdoc/html/format.rs
index 493fdc6fb1b..8c75f301841 100644
--- a/src/librustdoc/html/format.rs
+++ b/src/librustdoc/html/format.rs
@@ -1264,6 +1264,7 @@ impl std::fmt::Write for WriteCounter {
 }
 
 // Implements Display by emitting the given number of spaces.
+#[derive(Clone, Copy)]
 struct Indent(usize);
 
 impl Display for Indent {
@@ -1275,6 +1276,37 @@ impl Display for Indent {
     }
 }
 
+impl clean::Parameter {
+    fn print(&self, cx: &Context<'_>) -> impl fmt::Display {
+        fmt::from_fn(move |f| {
+            if let Some(self_ty) = self.to_receiver() {
+                match self_ty {
+                    clean::SelfTy => f.write_str("self"),
+                    clean::BorrowedRef { lifetime, mutability, type_: box clean::SelfTy } => {
+                        f.write_str(if f.alternate() { "&" } else { "&amp;" })?;
+                        if let Some(lt) = lifetime {
+                            write!(f, "{lt} ", lt = lt.print())?;
+                        }
+                        write!(f, "{mutability}self", mutability = mutability.print_with_space())
+                    }
+                    _ => {
+                        f.write_str("self: ")?;
+                        self_ty.print(cx).fmt(f)
+                    }
+                }
+            } else {
+                if self.is_const {
+                    write!(f, "const ")?;
+                }
+                if let Some(name) = self.name {
+                    write!(f, "{name}: ")?;
+                }
+                self.type_.print(cx).fmt(f)
+            }
+        })
+    }
+}
+
 impl clean::FnDecl {
     pub(crate) fn print(&self, cx: &Context<'_>) -> impl Display {
         fmt::from_fn(move |f| {
@@ -1333,63 +1365,42 @@ impl clean::FnDecl {
         f: &mut fmt::Formatter<'_>,
         cx: &Context<'_>,
     ) -> fmt::Result {
-        let amp = if f.alternate() { "&" } else { "&amp;" };
+        f.write_char('(')?;
 
-        write!(f, "(")?;
-        if let Some(n) = line_wrapping_indent
-            && !self.inputs.is_empty()
-        {
-            write!(f, "\n{}", Indent(n + 4))?;
-        }
+        if !self.inputs.is_empty() {
+            let line_wrapping_indent = line_wrapping_indent.map(|n| Indent(n + 4));
 
-        let last_input_index = self.inputs.len().checked_sub(1);
-        for (i, param) in self.inputs.iter().enumerate() {
-            if let Some(selfty) = param.to_receiver() {
-                match selfty {
-                    clean::SelfTy => {
-                        write!(f, "self")?;
-                    }
-                    clean::BorrowedRef { lifetime, mutability, type_: box clean::SelfTy } => {
-                        write!(f, "{amp}")?;
-                        if let Some(lt) = lifetime {
-                            write!(f, "{lt} ", lt = lt.print())?;
-                        }
-                        write!(f, "{mutability}self", mutability = mutability.print_with_space())?;
-                    }
-                    _ => {
-                        write!(f, "self: ")?;
-                        selfty.print(cx).fmt(f)?;
-                    }
-                }
-            } else {
-                if param.is_const {
-                    write!(f, "const ")?;
-                }
-                if let Some(name) = param.name {
-                    write!(f, "{name}: ")?;
+            if let Some(indent) = line_wrapping_indent {
+                write!(f, "\n{indent}")?;
+            }
+
+            let sep = fmt::from_fn(|f| {
+                if let Some(indent) = line_wrapping_indent {
+                    write!(f, ",\n{indent}")
+                } else {
+                    f.write_str(", ")
                 }
-                param.type_.print(cx).fmt(f)?;
+            });
+
+            self.inputs.iter().map(|param| param.print(cx)).joined(sep, f)?;
+
+            if line_wrapping_indent.is_some() {
+                writeln!(f, ",")?
             }
-            match (line_wrapping_indent, last_input_index) {
-                (_, None) => (),
-                (None, Some(last_i)) if i != last_i => write!(f, ", ")?,
-                (None, Some(_)) => (),
-                (Some(n), Some(last_i)) if i != last_i => write!(f, ",\n{}", Indent(n + 4))?,
-                (Some(_), Some(_)) => writeln!(f, ",")?,
+
+            if self.c_variadic {
+                match line_wrapping_indent {
+                    None => write!(f, ", ...")?,
+                    Some(indent) => writeln!(f, "{indent}...")?,
+                };
             }
         }
 
-        if self.c_variadic {
-            match line_wrapping_indent {
-                None => write!(f, ", ...")?,
-                Some(n) => writeln!(f, "{}...", Indent(n + 4))?,
-            };
+        if let Some(n) = line_wrapping_indent {
+            write!(f, "{}", Indent(n))?
         }
 
-        match line_wrapping_indent {
-            None => write!(f, ")")?,
-            Some(n) => write!(f, "{})", Indent(n))?,
-        };
+        f.write_char(')')?;
 
         self.print_output(cx).fmt(f)
     }
diff --git a/src/librustdoc/html/render/mod.rs b/src/librustdoc/html/render/mod.rs
index b4ef47d1e26..6d684449b6d 100644
--- a/src/librustdoc/html/render/mod.rs
+++ b/src/librustdoc/html/render/mod.rs
@@ -2454,11 +2454,11 @@ fn get_id_for_impl(tcx: TyCtxt<'_>, impl_id: ItemId) -> String {
             (ty, Some(ty::TraitRef::new(tcx, trait_, [ty])))
         }
         ItemId::Blanket { impl_id, .. } | ItemId::DefId(impl_id) => {
-            match tcx.impl_subject(impl_id).skip_binder() {
-                ty::ImplSubject::Trait(trait_ref) => {
-                    (trait_ref.args[0].expect_ty(), Some(trait_ref))
-                }
-                ty::ImplSubject::Inherent(ty) => (ty, None),
+            if let Some(trait_ref) = tcx.impl_trait_ref(impl_id) {
+                let trait_ref = trait_ref.skip_binder();
+                (trait_ref.self_ty(), Some(trait_ref))
+            } else {
+                (tcx.type_of(impl_id).skip_binder(), None)
             }
         }
     };
diff --git a/src/tools/clippy/clippy_utils/src/qualify_min_const_fn.rs b/src/tools/clippy/clippy_utils/src/qualify_min_const_fn.rs
index 40fd2cdeb86..2bda6d50373 100644
--- a/src/tools/clippy/clippy_utils/src/qualify_min_const_fn.rs
+++ b/src/tools/clippy/clippy_utils/src/qualify_min_const_fn.rs
@@ -86,7 +86,7 @@ fn check_ty<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'tcx>, span: Span, msrv: Msrv)
             ty::FnPtr(..) => {
                 return Err((span, "function pointers in const fn are unstable".into()));
             },
-            ty::Dynamic(preds, _, _) => {
+            ty::Dynamic(preds, _) => {
                 for pred in *preds {
                     match pred.skip_binder() {
                         ty::ExistentialPredicate::AutoTrait(_) | ty::ExistentialPredicate::Projection(_) => {
diff --git a/src/tools/clippy/clippy_utils/src/ty/mod.rs b/src/tools/clippy/clippy_utils/src/ty/mod.rs
index 9f77a1c4d9b..3e41bce1dc4 100644
--- a/src/tools/clippy/clippy_utils/src/ty/mod.rs
+++ b/src/tools/clippy/clippy_utils/src/ty/mod.rs
@@ -349,7 +349,7 @@ pub fn is_must_use_ty<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'tcx>) -> bool {
             }
             false
         },
-        ty::Dynamic(binder, _, _) => {
+        ty::Dynamic(binder, _) => {
             for predicate in *binder {
                 if let ty::ExistentialPredicate::Trait(ref trait_ref) = predicate.skip_binder()
                     && find_attr!(cx.tcx.get_all_attrs(trait_ref.def_id), AttributeKind::MustUse { .. })
@@ -673,7 +673,7 @@ pub fn ty_sig<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'tcx>) -> Option<ExprFnSig<'t
             cx.tcx.opt_parent(def_id),
         ),
         ty::FnPtr(sig_tys, hdr) => Some(ExprFnSig::Sig(sig_tys.with(hdr), None)),
-        ty::Dynamic(bounds, _, _) => {
+        ty::Dynamic(bounds, _) => {
             let lang_items = cx.tcx.lang_items();
             match bounds.principal() {
                 Some(bound)