Rollup merge of #110386 - nnethercote:clean-up-traversal-macros, r=lcnr

Clean up traversal macros

The declarative macros relating to type folding and visiting can be simplified.

r? ``@lcnr``

8 files changed, 54 insertions, 206 deletions

diff --git a/compiler/rustc_middle/src/infer/canonical.rs b/compiler/rustc_middle/src/infer/canonical.rs
index e63121475a1..c4e41e00520 100644
--- a/compiler/rustc_middle/src/infer/canonical.rs
+++ b/compiler/rustc_middle/src/infer/canonical.rs
@@ -392,10 +392,8 @@ pub type QueryOutlivesConstraint<'tcx> =
     (ty::OutlivesPredicate<GenericArg<'tcx>, Region<'tcx>>, ConstraintCategory<'tcx>);
 
 TrivialTypeTraversalAndLiftImpls! {
-    for <'tcx> {
-        crate::infer::canonical::Certainty,
-        crate::infer::canonical::CanonicalTyVarKind,
-    }
+    crate::infer::canonical::Certainty,
+    crate::infer::canonical::CanonicalTyVarKind,
 }
 
 impl<'tcx> CanonicalVarValues<'tcx> {
diff --git a/compiler/rustc_middle/src/macros.rs b/compiler/rustc_middle/src/macros.rs
index 89014f62d4d..cd1c6c330bc 100644
--- a/compiler/rustc_middle/src/macros.rs
+++ b/compiler/rustc_middle/src/macros.rs
@@ -43,34 +43,26 @@ macro_rules! span_bug {
 
 #[macro_export]
 macro_rules! CloneLiftImpls {
-    (for <$tcx:lifetime> { $($ty:ty,)+ }) => {
+    ($($ty:ty,)+) => {
         $(
-            impl<$tcx> $crate::ty::Lift<$tcx> for $ty {
+            impl<'tcx> $crate::ty::Lift<'tcx> for $ty {
                 type Lifted = Self;
-                fn lift_to_tcx(self, _: $crate::ty::TyCtxt<$tcx>) -> Option<Self> {
+                fn lift_to_tcx(self, _: $crate::ty::TyCtxt<'tcx>) -> Option<Self> {
                     Some(self)
                 }
             }
         )+
     };
-
-    ($($ty:ty,)+) => {
-        CloneLiftImpls! {
-            for <'tcx> {
-                $($ty,)+
-            }
-        }
-    };
 }
 
 /// Used for types that are `Copy` and which **do not care arena
 /// allocated data** (i.e., don't need to be folded).
 #[macro_export]
 macro_rules! TrivialTypeTraversalImpls {
-    (for <$tcx:lifetime> { $($ty:ty,)+ }) => {
+    ($($ty:ty,)+) => {
         $(
-            impl<$tcx> $crate::ty::fold::TypeFoldable<$crate::ty::TyCtxt<$tcx>> for $ty {
-                fn try_fold_with<F: $crate::ty::fold::FallibleTypeFolder<$crate::ty::TyCtxt<$tcx>>>(
+            impl<'tcx> $crate::ty::fold::TypeFoldable<$crate::ty::TyCtxt<'tcx>> for $ty {
+                fn try_fold_with<F: $crate::ty::fold::FallibleTypeFolder<$crate::ty::TyCtxt<'tcx>>>(
                     self,
                     _: &mut F,
                 ) -> ::std::result::Result<Self, F::Error> {
@@ -78,7 +70,7 @@ macro_rules! TrivialTypeTraversalImpls {
                 }
 
                 #[inline]
-                fn fold_with<F: $crate::ty::fold::TypeFolder<$crate::ty::TyCtxt<$tcx>>>(
+                fn fold_with<F: $crate::ty::fold::TypeFolder<$crate::ty::TyCtxt<'tcx>>>(
                     self,
                     _: &mut F,
                 ) -> Self {
@@ -86,9 +78,9 @@ macro_rules! TrivialTypeTraversalImpls {
                 }
             }
 
-            impl<$tcx> $crate::ty::visit::TypeVisitable<$crate::ty::TyCtxt<$tcx>> for $ty {
+            impl<'tcx> $crate::ty::visit::TypeVisitable<$crate::ty::TyCtxt<'tcx>> for $ty {
                 #[inline]
-                fn visit_with<F: $crate::ty::visit::TypeVisitor<$crate::ty::TyCtxt<$tcx>>>(
+                fn visit_with<F: $crate::ty::visit::TypeVisitor<$crate::ty::TyCtxt<'tcx>>>(
                     &self,
                     _: &mut F)
                     -> ::std::ops::ControlFlow<F::BreakTy>
@@ -98,14 +90,6 @@ macro_rules! TrivialTypeTraversalImpls {
             }
         )+
     };
-
-    ($($ty:ty,)+) => {
-        TrivialTypeTraversalImpls! {
-            for<'tcx> {
-                $($ty,)+
-            }
-        }
-    };
 }
 
 #[macro_export]
diff --git a/compiler/rustc_middle/src/mir/mod.rs b/compiler/rustc_middle/src/mir/mod.rs
index 2ea8602af12..f985aae9a22 100644
--- a/compiler/rustc_middle/src/mir/mod.rs
+++ b/compiler/rustc_middle/src/mir/mod.rs
@@ -714,9 +714,7 @@ pub enum BindingForm<'tcx> {
 }
 
 TrivialTypeTraversalAndLiftImpls! {
-    for<'tcx> {
-        BindingForm<'tcx>,
-    }
+    BindingForm<'tcx>,
 }
 
 mod binding_form_impl {
diff --git a/compiler/rustc_middle/src/mir/type_foldable.rs b/compiler/rustc_middle/src/mir/type_foldable.rs
index 9881583214e..ace856b9f95 100644
--- a/compiler/rustc_middle/src/mir/type_foldable.rs
+++ b/compiler/rustc_middle/src/mir/type_foldable.rs
@@ -25,9 +25,7 @@ TrivialTypeTraversalAndLiftImpls! {
 }
 
 TrivialTypeTraversalImpls! {
-    for <'tcx> {
-        ConstValue<'tcx>,
-    }
+    ConstValue<'tcx>,
 }
 
 impl<'tcx> TypeFoldable<TyCtxt<'tcx>> for &'tcx [InlineAsmTemplatePiece] {
diff --git a/compiler/rustc_middle/src/ty/context.rs b/compiler/rustc_middle/src/ty/context.rs
index 63f7cc2ee73..e5356581e6e 100644
--- a/compiler/rustc_middle/src/ty/context.rs
+++ b/compiler/rustc_middle/src/ty/context.rs
@@ -1329,9 +1329,12 @@ nop_list_lift! {bound_variable_kinds; ty::BoundVariableKind => ty::BoundVariable
 // This is the impl for `&'a InternalSubsts<'a>`.
 nop_list_lift! {substs; GenericArg<'a> => GenericArg<'tcx>}
 
-CloneLiftImpls! { for<'tcx> {
-    Constness, traits::WellFormedLoc, ImplPolarity, crate::mir::ReturnConstraint,
-} }
+CloneLiftImpls! {
+    Constness,
+    traits::WellFormedLoc,
+    ImplPolarity,
+    crate::mir::ReturnConstraint,
+}
 
 macro_rules! sty_debug_print {
     ($fmt: expr, $ctxt: expr, $($variant: ident),*) => {{
diff --git a/compiler/rustc_middle/src/ty/structural_impls.rs b/compiler/rustc_middle/src/ty/structural_impls.rs
index 619fcea8b7d..7706fdddeb8 100644
--- a/compiler/rustc_middle/src/ty/structural_impls.rs
+++ b/compiler/rustc_middle/src/ty/structural_impls.rs
@@ -276,9 +276,7 @@ TrivialTypeTraversalAndLiftImpls! {
 }
 
 TrivialTypeTraversalAndLiftImpls! {
-    for<'tcx> {
-        ty::ValTree<'tcx>,
-    }
+    ty::ValTree<'tcx>,
 }
 
 ///////////////////////////////////////////////////////////////////////////
diff --git a/compiler/rustc_type_ir/src/macros.rs b/compiler/rustc_type_ir/src/macros.rs
index 6c181039730..8c3cb228322 100644
--- a/compiler/rustc_type_ir/src/macros.rs
+++ b/compiler/rustc_type_ir/src/macros.rs
@@ -33,144 +33,3 @@ macro_rules! TrivialTypeTraversalImpls {
         )+
     };
 }
-
-macro_rules! EnumTypeTraversalImpl {
-    (impl<$($p:tt),*> TypeFoldable<$tcx:tt> for $s:path {
-        $($variants:tt)*
-    } $(where $($wc:tt)*)*) => {
-        impl<$($p),*> $crate::fold::TypeFoldable<$tcx> for $s
-            $(where $($wc)*)*
-        {
-            fn try_fold_with<V: $crate::fold::FallibleTypeFolder<$tcx>>(
-                self,
-                folder: &mut V,
-            ) -> ::std::result::Result<Self, V::Error> {
-                EnumTypeTraversalImpl!(@FoldVariants(self, folder) input($($variants)*) output())
-            }
-        }
-    };
-
-    (impl<$($p:tt),*> TypeVisitable<$tcx:tt> for $s:path {
-        $($variants:tt)*
-    } $(where $($wc:tt)*)*) => {
-        impl<$($p),*> $crate::visit::TypeVisitable<$tcx> for $s
-            $(where $($wc)*)*
-        {
-            fn visit_with<V: $crate::visit::TypeVisitor<$tcx>>(
-                &self,
-                visitor: &mut V,
-            ) -> ::std::ops::ControlFlow<V::BreakTy> {
-                EnumTypeTraversalImpl!(@VisitVariants(self, visitor) input($($variants)*) output())
-            }
-        }
-    };
-
-    (@FoldVariants($this:expr, $folder:expr) input() output($($output:tt)*)) => {
-        Ok(match $this {
-            $($output)*
-        })
-    };
-
-    (@FoldVariants($this:expr, $folder:expr)
-     input( ($variant:path) ( $($variant_arg:ident),* ) , $($input:tt)*)
-     output( $($output:tt)*) ) => {
-        EnumTypeTraversalImpl!(
-            @FoldVariants($this, $folder)
-                input($($input)*)
-                output(
-                    $variant ( $($variant_arg),* ) => {
-                        $variant (
-                            $($crate::fold::TypeFoldable::try_fold_with($variant_arg, $folder)?),*
-                        )
-                    }
-                    $($output)*
-                )
-        )
-    };
-
-    (@FoldVariants($this:expr, $folder:expr)
-     input( ($variant:path) { $($variant_arg:ident),* $(,)? } , $($input:tt)*)
-     output( $($output:tt)*) ) => {
-        EnumTypeTraversalImpl!(
-            @FoldVariants($this, $folder)
-                input($($input)*)
-                output(
-                    $variant { $($variant_arg),* } => {
-                        $variant {
-                            $($variant_arg: $crate::fold::TypeFoldable::fold_with(
-                                $variant_arg, $folder
-                            )?),* }
-                    }
-                    $($output)*
-                )
-        )
-    };
-
-    (@FoldVariants($this:expr, $folder:expr)
-     input( ($variant:path), $($input:tt)*)
-     output( $($output:tt)*) ) => {
-        EnumTypeTraversalImpl!(
-            @FoldVariants($this, $folder)
-                input($($input)*)
-                output(
-                    $variant => { $variant }
-                    $($output)*
-                )
-        )
-    };
-
-    (@VisitVariants($this:expr, $visitor:expr) input() output($($output:tt)*)) => {
-        match $this {
-            $($output)*
-        }
-    };
-
-    (@VisitVariants($this:expr, $visitor:expr)
-     input( ($variant:path) ( $($variant_arg:ident),* ) , $($input:tt)*)
-     output( $($output:tt)*) ) => {
-        EnumTypeTraversalImpl!(
-            @VisitVariants($this, $visitor)
-                input($($input)*)
-                output(
-                    $variant ( $($variant_arg),* ) => {
-                        $($crate::visit::TypeVisitable::visit_with(
-                            $variant_arg, $visitor
-                        )?;)*
-                        ::std::ops::ControlFlow::Continue(())
-                    }
-                    $($output)*
-                )
-        )
-    };
-
-    (@VisitVariants($this:expr, $visitor:expr)
-     input( ($variant:path) { $($variant_arg:ident),* $(,)? } , $($input:tt)*)
-     output( $($output:tt)*) ) => {
-        EnumTypeTraversalImpl!(
-            @VisitVariants($this, $visitor)
-                input($($input)*)
-                output(
-                    $variant { $($variant_arg),* } => {
-                        $($crate::visit::TypeVisitable::visit_with(
-                            $variant_arg, $visitor
-                        )?;)*
-                        ::std::ops::ControlFlow::Continue(())
-                    }
-                    $($output)*
-                )
-        )
-    };
-
-    (@VisitVariants($this:expr, $visitor:expr)
-     input( ($variant:path), $($input:tt)*)
-     output( $($output:tt)*) ) => {
-        EnumTypeTraversalImpl!(
-            @VisitVariants($this, $visitor)
-                input($($input)*)
-                output(
-                    $variant => { ::std::ops::ControlFlow::Continue(()) }
-                    $($output)*
-                )
-        )
-    };
-}
diff --git a/compiler/rustc_type_ir/src/structural_impls.rs b/compiler/rustc_type_ir/src/structural_impls.rs
index 3ebe241042f..c90c86b7690 100644
--- a/compiler/rustc_type_ir/src/structural_impls.rs
+++ b/compiler/rustc_type_ir/src/structural_impls.rs
@@ -70,30 +70,40 @@ impl<I: Interner, A: TypeVisitable<I>, B: TypeVisitable<I>, C: TypeVisitable<I>>
     }
 }
 
-EnumTypeTraversalImpl! {
-    impl<I, T> TypeFoldable<I> for Option<T> {
-        (Some)(a),
-        (None),
-    } where I: Interner, T: TypeFoldable<I>
-}
-EnumTypeTraversalImpl! {
-    impl<I, T> TypeVisitable<I> for Option<T> {
-        (Some)(a),
-        (None),
-    } where I: Interner, T: TypeVisitable<I>
-}
-
-EnumTypeTraversalImpl! {
-    impl<I, T, E> TypeFoldable<I> for Result<T, E> {
-        (Ok)(a),
-        (Err)(a),
-    } where I: Interner, T: TypeFoldable<I>, E: TypeFoldable<I>,
-}
-EnumTypeTraversalImpl! {
-    impl<I, T, E> TypeVisitable<I> for Result<T, E> {
-        (Ok)(a),
-        (Err)(a),
-    } where I: Interner, T: TypeVisitable<I>, E: TypeVisitable<I>,
+impl<I: Interner, T: TypeFoldable<I>> TypeFoldable<I> for Option<T> {
+    fn try_fold_with<F: FallibleTypeFolder<I>>(self, folder: &mut F) -> Result<Self, F::Error> {
+        Ok(match self {
+            Some(v) => Some(v.try_fold_with(folder)?),
+            None => None,
+        })
+    }
+}
+
+impl<I: Interner, T: TypeVisitable<I>> TypeVisitable<I> for Option<T> {
+    fn visit_with<V: TypeVisitor<I>>(&self, visitor: &mut V) -> ControlFlow<V::BreakTy> {
+        match self {
+            Some(v) => v.visit_with(visitor),
+            None => ControlFlow::Continue(()),
+        }
+    }
+}
+
+impl<I: Interner, T: TypeFoldable<I>, E: TypeFoldable<I>> TypeFoldable<I> for Result<T, E> {
+    fn try_fold_with<F: FallibleTypeFolder<I>>(self, folder: &mut F) -> Result<Self, F::Error> {
+        Ok(match self {
+            Ok(v) => Ok(v.try_fold_with(folder)?),
+            Err(e) => Err(e.try_fold_with(folder)?),
+        })
+    }
+}
+
+impl<I: Interner, T: TypeVisitable<I>, E: TypeVisitable<I>> TypeVisitable<I> for Result<T, E> {
+    fn visit_with<V: TypeVisitor<I>>(&self, visitor: &mut V) -> ControlFlow<V::BreakTy> {
+        match self {
+            Ok(v) => v.visit_with(visitor),
+            Err(e) => e.visit_with(visitor),
+        }
+    }
 }
 
 impl<I: Interner, T: TypeFoldable<I>> TypeFoldable<I> for Rc<T> {