From 204f4eea6f9226294691712a10929f91a7e376cd Mon Sep 17 00:00:00 2001
From: Niko Matsakis <niko@alum.mit.edu>
Date: Sat, 6 Jul 2024 08:34:59 -0400
Subject: [PATCH] move struct debug name to Configuration

---
 components/salsa-macros/src/tracked_struct.rs | 11 ++++++++---
 src/tracked_struct.rs                         | 10 ++++------
 src/tracked_struct/tracked_field.rs           |  3 +--
 3 files changed, 13 insertions(+), 11 deletions(-)

diff --git a/components/salsa-macros/src/tracked_struct.rs b/components/salsa-macros/src/tracked_struct.rs
index 5cd549d..9d4c59d 100644
--- a/components/salsa-macros/src/tracked_struct.rs
+++ b/components/salsa-macros/src/tracked_struct.rs
@@ -1,6 +1,9 @@
 use proc_macro2::{Literal, Span, TokenStream};
 
-use crate::salsa_struct::{SalsaField, SalsaStruct, TheStructKind};
+use crate::{
+    literal,
+    salsa_struct::{SalsaField, SalsaStruct, TheStructKind},
+};
 
 /// For an tracked struct `Foo` with fields `f1: T1, ..., fN: TN`, we generate...
 ///
@@ -105,6 +108,7 @@ impl TrackedStruct {
         let arity = self.all_field_count();
         let the_ident = self.the_ident();
         let lt_db = &self.named_db_lifetime();
+        let debug_name_struct = literal(self.the_ident());
 
         // Create the function body that will update the revisions for each field.
         // If a field is a "backdate field" (the default), then we first check if
@@ -143,6 +147,8 @@ impl TrackedStruct {
 
         parse_quote! {
             impl salsa::tracked_struct::Configuration for #config_ident {
+                const DEBUG_NAME: &'static str = #debug_name_struct;
+
                 type Fields<#lt_db> = ( #(#field_tys,)* );
 
                 type Struct<#lt_db> = #the_ident<#lt_db>;
@@ -263,7 +269,6 @@ impl TrackedStruct {
         let arity = self.all_field_count();
         let tracked_struct_ingredient: Literal = self.tracked_struct_ingredient_index();
         let tracked_fields_ingredients: Literal = self.tracked_field_ingredients_index();
-        let debug_name_struct = literal(self.the_ident());
         let debug_name_fields: Vec<_> = self.all_field_names().into_iter().map(literal).collect();
 
         parse_quote! {
@@ -294,7 +299,7 @@ impl TrackedStruct {
                                 &mut ingredients.#tracked_struct_ingredient
                             },
                         );
-                        salsa::tracked_struct::TrackedStructIngredient::new(index, #debug_name_struct)
+                        salsa::tracked_struct::TrackedStructIngredient::new(index)
                     };
 
                     let field_ingredients = [
diff --git a/src/tracked_struct.rs b/src/tracked_struct.rs
index b1a9238..95b5386 100644
--- a/src/tracked_struct.rs
+++ b/src/tracked_struct.rs
@@ -26,6 +26,8 @@ mod tracked_field;
 /// Implemented by the `#[salsa::tracked]` macro when applied
 /// to a struct.
 pub trait Configuration: Sized + 'static {
+    const DEBUG_NAME: &'static str;
+
     /// A (possibly empty) tuple of the fields for this struct.
     type Fields<'db>;
 
@@ -134,8 +136,6 @@ where
     /// each of these functions will be notified
     /// so they can remove any data tied to that instance.
     dependent_fns: IngredientList,
-
-    debug_name: &'static str,
 }
 
 /// Defines the identity of a tracked struct.
@@ -215,14 +215,13 @@ where
 
     /// Create a tracked struct ingredient. Generated by the `#[tracked]` macro,
     /// not meant to be called directly by end-users.
-    pub fn new(index: IngredientIndex, debug_name: &'static str) -> Self {
+    pub fn new(index: IngredientIndex) -> Self {
         Self {
             ingredient_index: index,
             keys: FxDashMap::default(),
             counter: AtomicCell::new(0),
             struct_map: StructMap::new(),
             dependent_fns: IngredientList::new(),
-            debug_name,
         }
     }
 
@@ -243,7 +242,6 @@ where
             ingredient_index: field_ingredient_index,
             field_index,
             struct_map: self.struct_map.view(),
-            struct_debug_name: self.debug_name,
             field_debug_name,
         }
     }
@@ -457,7 +455,7 @@ where
     }
 
     fn fmt_index(&self, index: Option<crate::Id>, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
-        fmt_index(self.debug_name, index, fmt)
+        fmt_index(C::DEBUG_NAME, index, fmt)
     }
 }
 
diff --git a/src/tracked_struct/tracked_field.rs b/src/tracked_struct/tracked_field.rs
index 5e7bc1b..0774a47 100644
--- a/src/tracked_struct/tracked_field.rs
+++ b/src/tracked_struct/tracked_field.rs
@@ -23,7 +23,6 @@ where
     pub(super) ingredient_index: IngredientIndex,
     pub(super) field_index: u32,
     pub(super) struct_map: StructMapView<C>,
-    pub(super) struct_debug_name: &'static str,
     pub(super) field_debug_name: &'static str,
 }
 
@@ -122,7 +121,7 @@ where
         write!(
             fmt,
             "{}.{}({:?})",
-            self.struct_debug_name,
+            C::DEBUG_NAME,
             self.field_debug_name,
             index.unwrap()
         )