feat: Implement Return Position Impl Trait In Traits correctly

Cargo.toml

@@ -160,6 +160,7 @@ tracing-subscriber = { version = "0.3.19", default-features = false, features =
 triomphe = { version = "0.1.14", default-features = false, features = ["std"] }
 url = "2.5.4"
 xshell = "0.2.7"
+thin-vec = "0.2.14"
 
 # We need to freeze the version of the crate, as the raw-api feature is considered unstable
 dashmap = { version = "=6.1.0", features = ["raw-api", "inline"] }

crates/base-db/src/lib.rs

@@ -28,6 +28,7 @@ use syntax::{Parse, SyntaxError, ast};
 use triomphe::Arc;
 pub use vfs::{AnchoredPath, AnchoredPathBuf, FileId, VfsPath, file_set::FileSet};
 
+/// Prefer to use `impl_intern_key_ref!()`, which will not clone the value.
 #[macro_export]
 macro_rules! impl_intern_key {
     ($id:ident, $loc:ident) => {
@@ -47,6 +48,26 @@ macro_rules! impl_intern_key {
     };
 }
 
+#[macro_export]
+macro_rules! impl_intern_key_ref {
+    ($id:ident, $loc:ident) => {
+        #[salsa_macros::interned(no_lifetime)]
+        pub struct $id {
+            #[return_ref]
+            pub loc: $loc,
+        }
+
+        // If we derive this salsa prints the values recursively, and this causes us to blow.
+        impl ::std::fmt::Debug for $id {
+            fn fmt(&self, f: &mut ::std::fmt::Formatter<'_>) -> ::std::fmt::Result {
+                f.debug_tuple(stringify!($id))
+                    .field(&format_args!("{:04x}", self.0.as_u32()))
+                    .finish()
+            }
+        }
+    };
+}
+
 pub const DEFAULT_FILE_TEXT_LRU_CAP: u16 = 16;
 pub const DEFAULT_PARSE_LRU_CAP: u16 = 128;
 pub const DEFAULT_BORROWCK_LRU_CAP: u16 = 2024;

crates/hir-def/Cargo.toml

@@ -44,7 +44,7 @@ mbe.workspace = true
 cfg.workspace = true
 tt.workspace = true
 span.workspace = true
-thin-vec = "0.2.14"
+thin-vec.workspace = true
 
 [dev-dependencies]
 expect-test.workspace = true

crates/hir-ty/Cargo.toml

@@ -35,6 +35,7 @@ rustc_apfloat = "0.2.2"
 query-group.workspace = true
 salsa.workspace = true
 salsa-macros.workspace = true
+thin-vec.workspace = true
 
 ra-ap-rustc_abi.workspace = true
 ra-ap-rustc_index.workspace = true