Auto merge of #119139 - michaelwoerister:cleanup-stable-source-file-id, r=cjgillot

Unify SourceFile::name_hash and StableSourceFileId

This PR adapts the existing `StableSourceFileId` type so that it can be used instead of the `name_hash` field of `SourceFile`. This simplifies a few things that were kind of duplicated before.

The PR should also fix issues https://github.com/rust-lang/rust/issues/112700 and https://github.com/rust-lang/rust/issues/115835, but I was not able to reproduce these issues in a regression test. As far as I can tell, the root cause of these issues is that the id of the originating crate is not hashed in the `HashStable` impl of `Span` and thus cache entries that should have been considered invalidated were loaded. After this PR, the `stable_id` field of `SourceFile` includes information about the originating crate, so that ICE should not occur anymore.

1 files changed, 3 insertions, 3 deletions

diff --git a/compiler/rustc_query_system/src/ich/impls_syntax.rs b/compiler/rustc_query_system/src/ich/impls_syntax.rs
index f2387017c82..d170cd36ca6 100644
--- a/compiler/rustc_query_system/src/ich/impls_syntax.rs
+++ b/compiler/rustc_query_system/src/ich/impls_syntax.rs
@@ -60,8 +60,8 @@ impl<'ctx> rustc_ast::HashStableContext for StableHashingContext<'ctx> {
 impl<'a> HashStable<StableHashingContext<'a>> for SourceFile {
     fn hash_stable(&self, hcx: &mut StableHashingContext<'a>, hasher: &mut StableHasher) {
         let SourceFile {
-            name: _, // We hash the smaller name_hash instead of this
-            name_hash,
+            name: _, // We hash the smaller stable_id instead of this
+            stable_id,
             cnum,
             // Do not hash the source as it is not encoded
             src: _,
@@ -75,7 +75,7 @@ impl<'a> HashStable<StableHashingContext<'a>> for SourceFile {
             ref normalized_pos,
         } = *self;
 
-        name_hash.hash_stable(hcx, hasher);
+        stable_id.hash_stable(hcx, hasher);
 
         src_hash.hash_stable(hcx, hasher);