Use $K:ty in query macros.

This is simpler and nicer than `$($K:tt)*`, and possible thanks to the
previous two commits.

Author: nnethercote

compiler/rustc_middle/src/dep_graph/dep_node.rs

@@ -354,11 +354,12 @@ impl StableOrd for WorkProductId {
     const THIS_IMPLEMENTATION_HAS_BEEN_TRIPLE_CHECKED: () = ();
 }
 
+// Note: `$K` and `$V` are unused but present so this can be called by `rustc_with_all_queries`.
 macro_rules! define_dep_nodes {
     (
         $(
             $(#[$attr:meta])*
-            [$($modifiers:tt)*] fn $variant:ident($($K:tt)*) -> $V:ty,
+            [$($modifiers:tt)*] fn $variant:ident($K:ty) -> $V:ty,
         )*
     ) => {
 
@@ -425,18 +426,18 @@ macro_rules! define_dep_nodes {
 }
 
 // Create various data structures for each query, and also for a few things
-// that aren't queries.
+// that aren't queries. The key and return types aren't used, hence the use of `()`.
 rustc_with_all_queries!(define_dep_nodes![
     /// We use this for most things when incr. comp. is turned off.
-    [] fn Null() -> (),
+    [] fn Null(()) -> (),
     /// We use this to create a forever-red node.
-    [] fn Red() -> (),
-    [] fn SideEffect() -> (),
-    [] fn AnonZeroDeps() -> (),
-    [] fn TraitSelect() -> (),
-    [] fn CompileCodegenUnit() -> (),
-    [] fn CompileMonoItem() -> (),
-    [] fn Metadata() -> (),
+    [] fn Red(()) -> (),
+    [] fn SideEffect(()) -> (),
+    [] fn AnonZeroDeps(()) -> (),
+    [] fn TraitSelect(()) -> (),
+    [] fn CompileCodegenUnit(()) -> (),
+    [] fn CompileMonoItem(()) -> (),
+    [] fn Metadata(()) -> (),
 ]);
 
 // WARNING: `construct` is generic and does not know that `CompileCodegenUnit` takes `Symbol`s as keys.

compiler/rustc_middle/src/query/plumbing.rs

@@ -293,7 +293,7 @@ macro_rules! define_callbacks {
     (
         $(
             $(#[$attr:meta])*
-            [$($modifiers:tt)*] fn $name:ident($($K:tt)*) -> $V:ty,
+            [$($modifiers:tt)*] fn $name:ident($K:ty) -> $V:ty,
         )*
     ) => {
         $(
@@ -302,13 +302,13 @@ macro_rules! define_callbacks {
                 use super::*;
                 use $crate::query::erase::{self, Erased};
 
-                pub type Key<'tcx> = $($K)*;
+                pub type Key<'tcx> = $K;
                 pub type Value<'tcx> = $V;
 
                 pub type LocalKey<'tcx> = if_separate_provide_extern!(
                     [$($modifiers)*]
-                    (<$($K)* as $crate::query::AsLocalKey>::LocalKey)
-                    ($($K)*)
+                    (<$K as $crate::query::AsLocalKey>::LocalKey)
+                    ($K)
                 );
 
                 /// This type alias specifies the type returned from query providers and the type
@@ -349,7 +349,7 @@ macro_rules! define_callbacks {
                     erase::erase_val(value)
                 }
 
-                pub type Storage<'tcx> = <$($K)* as $crate::query::Key>::Cache<Erased<$V>>;
+                pub type Storage<'tcx> = <$K as $crate::query::Key>::Cache<Erased<$V>>;
 
                 // Ensure that keys grow no larger than 88 bytes by accident.
                 // Increase this limit if necessary, but do try to keep the size low if possible
@@ -360,7 +360,7 @@ macro_rules! define_callbacks {
                             "the query `",
                             stringify!($name),
                             "` has a key type `",
-                            stringify!($($K)*),
+                            stringify!($K),
                             "` that is too large"
                         ));
                     }
@@ -410,7 +410,7 @@ macro_rules! define_callbacks {
                 #[inline(always)]
                 pub fn $name(
                     self,
-                    key: impl $crate::query::IntoQueryParam<$($K)*>,
+                    key: impl $crate::query::IntoQueryParam<$K>,
                 ) -> if_return_result_from_ensure_ok!(
                     [$($modifiers)*]
                     (Result<(), ErrorGuaranteed>)
@@ -441,7 +441,7 @@ macro_rules! define_callbacks {
             $(
                 $(#[$attr])*
                 #[inline(always)]
-                pub fn $name(self, key: impl $crate::query::IntoQueryParam<$($K)*>) {
+                pub fn $name(self, key: impl $crate::query::IntoQueryParam<$K>) {
                     crate::query::inner::query_ensure(
                         self.tcx,
                         self.tcx.query_system.fns.engine.$name,
@@ -458,7 +458,7 @@ macro_rules! define_callbacks {
                 $(#[$attr])*
                 #[inline(always)]
                 #[must_use]
-                pub fn $name(self, key: impl $crate::query::IntoQueryParam<$($K)*>) -> $V {
+                pub fn $name(self, key: impl $crate::query::IntoQueryParam<$K>) -> $V {
                     self.at(DUMMY_SP).$name(key)
                 }
             )*
@@ -468,7 +468,7 @@ macro_rules! define_callbacks {
             $(
                 $(#[$attr])*
                 #[inline(always)]
-                pub fn $name(self, key: impl $crate::query::IntoQueryParam<$($K)*>) -> $V {
+                pub fn $name(self, key: impl $crate::query::IntoQueryParam<$K>) -> $V {
                     use $crate::query::{erase, inner};
 
                     erase::restore_val::<$V>(inner::query_get_at(
@@ -494,7 +494,7 @@ macro_rules! define_callbacks {
         #[derive(Default)]
         pub struct QueryStates<'tcx> {
             $(
-                pub $name: $crate::query::QueryState<'tcx, $($K)*>,
+                pub $name: $crate::query::QueryState<'tcx, $K>,
             )*
         }
 
@@ -571,15 +571,16 @@ macro_rules! define_callbacks {
     };
 }
 
+// Note: `$V` is unused but present so this can be called by `rustc_with_all_queries`.
 macro_rules! define_feedable {
     (
         $(
             $(#[$attr:meta])*
-            [$($modifiers:tt)*] fn $name:ident($($K:tt)*) -> $V:ty,
+            [$($modifiers:tt)*] fn $name:ident($K:ty) -> $V:ty,
         )*
     ) => {
         $(
-            impl<'tcx, K: $crate::query::IntoQueryParam<$($K)*> + Copy> TyCtxtFeed<'tcx, K> {
+            impl<'tcx, K: $crate::query::IntoQueryParam<$K> + Copy> TyCtxtFeed<'tcx, K> {
                 $(#[$attr])*
                 #[inline(always)]
                 pub fn $name(self, value: $name::ProvidedValue<'tcx>) {

compiler/rustc_query_impl/src/plumbing.rs

@@ -470,13 +470,12 @@ pub(crate) fn force_from_dep_node_inner<'tcx, C: QueryCache, const FLAGS: QueryF
     }
 }
 
-// NOTE: `$V` isn't used here, but we still need to match on it so it can be passed to other macros
-// invoked by `rustc_with_all_queries`.
+// Note: `$K` and `$V` are unused but present so this can be called by `rustc_with_all_queries`.
 macro_rules! define_queries {
     (
         $(
             $(#[$attr:meta])*
-            [$($modifiers:tt)*] fn $name:ident($($K:tt)*) -> $V:ty,
+            [$($modifiers:tt)*] fn $name:ident($K:ty) -> $V:ty,
         )*
     ) => {