Do not create a new NodeId when not used.

cjgillot · cjgillot · commit 9d6214fb6bdc · 2022-04-30T14:56:01.000+02:00
diff --git a/compiler/rustc_ast_lowering/src/lib.rs b/compiler/rustc_ast_lowering/src/lib.rs
@@ -646,9 +646,13 @@ impl<'hir> LoweringContext<'hir> {
         }
     }
 
+    /// Generate a new `HirId` without a backing `NodeId`.
     fn next_id(&mut self) -> hir::HirId {
-        let node_id = self.next_node_id();
-        self.lower_node_id(node_id)
+        let owner = self.current_hir_id_owner;
+        let local_id = self.item_local_id_counter;
+        assert_ne!(local_id, hir::ItemLocalId::new(0));
+        self.item_local_id_counter.increment_by(1);
+        hir::HirId { owner, local_id }
     }
 
     fn lower_res(&mut self, res: Res<NodeId>) -> Res {

Original file line number	Diff line number	Diff line change
`@@ -646,9 +646,13 @@ impl<'hir> LoweringContext<'hir> {`
`646`	`646`	`}`
`647`	`647`	`}`
`648`	`648`
	`649`	+ /// Generate a new `HirId` without a backing `NodeId`.
`649`	`650`	`fn next_id(&mut self) -> hir::HirId {`
`650`		`- let node_id = self.next_node_id();`
`651`		`- self.lower_node_id(node_id)`
	`651`	`+ let owner = self.current_hir_id_owner;`
	`652`	`+ let local_id = self.item_local_id_counter;`
	`653`	`+ assert_ne!(local_id, hir::ItemLocalId::new(0));`
	`654`	`+ self.item_local_id_counter.increment_by(1);`
	`655`	`+ hir::HirId { owner, local_id }`
`652`	`656`	`}`
`653`	`657`
`654`	`658`	`fn lower_res(&mut self, res: Res<NodeId>) -> Res {`