Remove DepKind name plumbing.

There is a bunch of plumbing to record the string `"foo"` for each
variant `DepKind::foo`. But that's what the `Debug `impl` now produces.
So this commit removes the plumbing.

compiler/rustc_middle/src/dep_graph/dep_node.rs

@@ -83,10 +83,6 @@ pub const fn as_usize(&self) -> usize {
         *self as usize
     }
 
-    pub(crate) fn name(self) -> &'static str {
-        DEP_KIND_NAMES[self.as_usize()]
-    }
-
     /// This is the highest value a `DepKind` can have. It's used during encoding to
     /// pack information into the unused bits.
     pub(crate) const MAX: u16 = DEP_KIND_NUM_VARIANTS - 1;
@@ -287,9 +283,6 @@ pub struct DepKindVTable<'tcx> {
 
     /// Invoke a query to put the on-disk cached value in memory.
     pub try_load_from_on_disk_cache: Option<fn(TyCtxt<'tcx>, DepNode)>,
-
-    /// The name of this dep kind.
-    pub name: &'static &'static str,
 }
 
 /// A "work product" corresponds to a `.o` (or other) file that we
@@ -372,12 +365,6 @@ pub enum DepKind {
             deps.len() as u16
         };
 
-        /// List containing the name of each dep kind as a static string,
-        /// indexable by `DepKind`.
-        pub(crate) const DEP_KIND_NAMES: &[&str] = &[
-            $( self::label_strs::$variant, )*
-        ];
-
         pub(super) fn dep_kind_from_label_string(label: &str) -> Result<DepKind, ()> {
             match label {
                 $( stringify!($variant) => Ok(self::DepKind::$variant), )*

compiler/rustc_middle/src/dep_graph/serialized.rs

@@ -288,13 +288,14 @@ pub fn decode(d: &mut MemDecoder<'_>) -> Arc<SerializedDepGraph> {
             if index[node.kind.as_usize()].insert(node.key_fingerprint, idx).is_some() {
                 // Empty nodes and side effect nodes can have duplicates
                 if node.kind != DepKind::Null && node.kind != DepKind::SideEffect {
-                    let name = node.kind.name();
+                    let kind = node.kind;
                     panic!(
-                    "Error: A dep graph node ({name}) does not have an unique index. \
-                     Running a clean build on a nightly compiler with `-Z incremental-verify-ich` \
-                     can help narrow down the issue for reporting. A clean build may also work around the issue.\n
-                     DepNode: {node:?}"
-                )
+                        "Error: A dep graph node ({kind:?}) does not have an unique index. \
+                         Running a clean build on a nightly compiler with \
+                         `-Z incremental-verify-ich` can help narrow down the issue for reporting. \
+                         A clean build may also work around the issue.\n
+                         DepNode: {node:?}"
+                    )
                 }
             }
         }

compiler/rustc_query_impl/src/dep_kind_vtables.rs

@@ -20,7 +20,6 @@ pub(crate) fn Null<'tcx>() -> DepKindVTable<'tcx> {
                 bug!("force_from_dep_node: encountered {dep_node:?}")
             }),
             try_load_from_on_disk_cache: None,
-            name: &"Null",
         }
     }
 
@@ -34,7 +33,6 @@ pub(crate) fn Red<'tcx>() -> DepKindVTable<'tcx> {
                 bug!("force_from_dep_node: encountered {dep_node:?}")
             }),
             try_load_from_on_disk_cache: None,
-            name: &"Red",
         }
     }
 
@@ -48,7 +46,6 @@ pub(crate) fn SideEffect<'tcx>() -> DepKindVTable<'tcx> {
                 true
             }),
             try_load_from_on_disk_cache: None,
-            name: &"SideEffect",
         }
     }
 
@@ -59,7 +56,6 @@ pub(crate) fn AnonZeroDeps<'tcx>() -> DepKindVTable<'tcx> {
             key_fingerprint_style: KeyFingerprintStyle::Opaque,
             force_from_dep_node: Some(|_, _, _| bug!("cannot force an anon node")),
             try_load_from_on_disk_cache: None,
-            name: &"AnonZeroDeps",
         }
     }
 
@@ -70,7 +66,6 @@ pub(crate) fn TraitSelect<'tcx>() -> DepKindVTable<'tcx> {
             key_fingerprint_style: KeyFingerprintStyle::Unit,
             force_from_dep_node: None,
             try_load_from_on_disk_cache: None,
-            name: &"TraitSelect",
         }
     }
 
@@ -81,7 +76,6 @@ pub(crate) fn CompileCodegenUnit<'tcx>() -> DepKindVTable<'tcx> {
             key_fingerprint_style: KeyFingerprintStyle::Opaque,
             force_from_dep_node: None,
             try_load_from_on_disk_cache: None,
-            name: &"CompileCodegenUnit",
         }
     }
 
@@ -92,7 +86,6 @@ pub(crate) fn CompileMonoItem<'tcx>() -> DepKindVTable<'tcx> {
             key_fingerprint_style: KeyFingerprintStyle::Opaque,
             force_from_dep_node: None,
             try_load_from_on_disk_cache: None,
-            name: &"CompileMonoItem",
         }
     }
 
@@ -103,7 +96,6 @@ pub(crate) fn Metadata<'tcx>() -> DepKindVTable<'tcx> {
             key_fingerprint_style: KeyFingerprintStyle::Unit,
             force_from_dep_node: None,
             try_load_from_on_disk_cache: None,
-            name: &"Metadata",
         }
     }
 }
@@ -131,7 +123,6 @@ pub(crate) fn make_dep_kind_vtable_for_query<'tcx, Q, Cache, const FLAGS: QueryF
             key_fingerprint_style,
             force_from_dep_node: None,
             try_load_from_on_disk_cache: None,
-            name: Q::NAME,
         };
     }
 
@@ -145,7 +136,6 @@ pub(crate) fn make_dep_kind_vtable_for_query<'tcx, Q, Cache, const FLAGS: QueryF
         try_load_from_on_disk_cache: Some(|tcx, dep_node| {
             try_load_from_on_disk_cache_inner(Q::query_dispatcher(tcx), tcx, dep_node)
         }),
-        name: Q::NAME,
     }
 }
 

compiler/rustc_query_impl/src/job.rs

@@ -423,10 +423,8 @@ pub fn print_query_stack<'tcx>(
         if let Some(ref mut file) = file {
             let _ = writeln!(
                 file,
-                "#{} [{}] {}",
-                count_total,
-                tcx.dep_kind_vtable(query_info.frame.dep_kind).name,
-                query_extra.description
+                "#{} [{:?}] {}",
+                count_total, query_info.frame.dep_kind, query_extra.description
             );
         }
 

compiler/rustc_query_impl/src/lib.rs

@@ -231,8 +231,6 @@ fn construct_dep_node(self, tcx: TyCtxt<'tcx>, key: &C::Key) -> DepNode {
 trait QueryDispatcherUnerased<'tcx, C: QueryCache, const FLAGS: QueryFlags> {
     type UnerasedValue;
 
-    const NAME: &'static &'static str;
-
     fn query_dispatcher(tcx: TyCtxt<'tcx>) -> SemiDynamicQueryDispatcher<'tcx, C, FLAGS>;
 
     fn restore_val(value: C::Value) -> Self::UnerasedValue;

compiler/rustc_query_impl/src/plumbing.rs

@@ -630,8 +630,6 @@ impl<'tcx> QueryDispatcherUnerased<'tcx, queries::$name::Storage<'tcx>, FLAGS>
             {
                 type UnerasedValue = queries::$name::Value<'tcx>;
 
-                const NAME: &'static &'static str = &stringify!($name);
-
                 #[inline(always)]
                 fn query_dispatcher(tcx: TyCtxt<'tcx>)
                     -> SemiDynamicQueryDispatcher<'tcx, queries::$name::Storage<'tcx>, FLAGS>