From 7519c3e2a6cc1ceaeb11b541acb677778a295ab8 Mon Sep 17 00:00:00 2001
From: Niko Matsakis <niko@alum.mit.edu>
Date: Sat, 18 May 2024 06:27:08 -0400
Subject: [PATCH] extend IdentityInterner to be based on LookupId

---
 .../salsa-2022-macros/src/tracked_fn.rs       |  4 ++--
 components/salsa-2022/src/interned.rs         | 20 ++++++++++++++++---
 2 files changed, 19 insertions(+), 5 deletions(-)

diff --git a/components/salsa-2022-macros/src/tracked_fn.rs b/components/salsa-2022-macros/src/tracked_fn.rs
index cbc1211f..0e67af52 100644
--- a/components/salsa-2022-macros/src/tracked_fn.rs
+++ b/components/salsa-2022-macros/src/tracked_fn.rs
@@ -431,7 +431,7 @@ fn fn_configuration(args: &FnArgs, item_fn: &syn::ItemFn) -> Configuration {
                 let (__jar, __runtime) = <_ as salsa::storage::HasJar<#jar_ty>>::jar(__db);
                 let __ingredients =
                     <_ as salsa::storage::HasIngredientsFor<#fn_ty>>::ingredient(__jar);
-                let #key_var = __ingredients.intern_map.data(__id).clone();
+                let #key_var = __ingredients.intern_map.data_with_db(__id, __db).clone();
                 #recovery_fn(__db, __cycle, #key_splat)
             }
         };
@@ -463,7 +463,7 @@ fn fn_configuration(args: &FnArgs, item_fn: &syn::ItemFn) -> Configuration {
             let (__jar, __runtime) = <_ as salsa::storage::HasJar<#jar_ty>>::jar(__db);
             let __ingredients =
                 <_ as salsa::storage::HasIngredientsFor<#fn_ty>>::ingredient(__jar);
-            let #key_var = __ingredients.intern_map.data(__id).clone();
+            let #key_var = __ingredients.intern_map.data_with_db(__id, __db).clone();
             #inner_fn_name(__db, #key_splat)
         }
     };
diff --git a/components/salsa-2022/src/interned.rs b/components/salsa-2022/src/interned.rs
index 6c276145..295b6adc 100644
--- a/components/salsa-2022/src/interned.rs
+++ b/components/salsa-2022/src/interned.rs
@@ -4,7 +4,7 @@ use std::hash::Hash;
 use std::marker::PhantomData;
 
 use crate::durability::Durability;
-use crate::id::AsId;
+use crate::id::{AsId, LookupId};
 use crate::ingredient::{fmt_index, IngredientRequiresReset};
 use crate::key::DependencyIndex;
 use crate::plumbing::transmute_lifetime;
@@ -141,10 +141,20 @@ where
         unsafe { transmute_lifetime(self, &**r) }
     }
 
+    /// Lookup the data for an interned value based on its id.
+    /// Rarely used since end-users generally carry a struct with a pointer directly
+    /// to the interned item.
     pub fn data<'db>(&'db self, id: Id) -> &'db C::Data<'db> {
         self.interned_value(id).data()
     }
 
+    /// Variant of `data` that takes a (unnecessary) database argument.
+    /// This exists because tracked functions sometimes use true interning and sometimes use
+    /// [`IdentityInterner`][], which requires the database argument.
+    pub fn data_with_db<'db, DB: ?Sized>(&'db self, id: Id, _db: &'db DB) -> &'db C::Data<'db> {
+        self.data(id)
+    }
+
     pub fn reset(&mut self, revision: Revision) {
         assert!(revision > self.reset_at);
         self.reset_at = revision;
@@ -242,8 +252,12 @@ where
         id.as_id()
     }
 
-    pub fn data<'db>(&'db self, id: crate::Id) -> C::Data<'db> {
-        <C::Data<'db>>::from_id(id)
+    pub fn data_with_db<'db, DB>(&'db self, id: crate::Id, db: &'db DB) -> C::Data<'db>
+    where
+        DB: ?Sized,
+        C::Data<'db>: LookupId<&'db DB>,
+    {
+        <C::Data<'db>>::lookup_id(id, db)
     }
 }