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.

2 files changed, 6 insertions, 5 deletions

diff --git a/compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs b/compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs
index 883f82caa80..59c075a3d3e 100644
--- a/compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs
+++ b/compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs
@@ -534,7 +534,7 @@ fn hex_encode(data: &[u8]) -> String {
 }
 
 pub fn file_metadata<'ll>(cx: &CodegenCx<'ll, '_>, source_file: &SourceFile) -> &'ll DIFile {
-    let cache_key = Some((source_file.name_hash, source_file.src_hash));
+    let cache_key = Some((source_file.stable_id, source_file.src_hash));
     return debug_context(cx)
         .created_files
         .borrow_mut()
diff --git a/compiler/rustc_codegen_llvm/src/debuginfo/mod.rs b/compiler/rustc_codegen_llvm/src/debuginfo/mod.rs
index 31631e8a864..d3a851b40c0 100644
--- a/compiler/rustc_codegen_llvm/src/debuginfo/mod.rs
+++ b/compiler/rustc_codegen_llvm/src/debuginfo/mod.rs
@@ -1,6 +1,7 @@
 #![doc = include_str!("doc.md")]
 
 use rustc_codegen_ssa::mir::debuginfo::VariableKind::*;
+use rustc_data_structures::unord::UnordMap;
 
 use self::metadata::{file_metadata, type_di_node};
 use self::metadata::{UNKNOWN_COLUMN_NUMBER, UNKNOWN_LINE_NUMBER};
@@ -20,8 +21,6 @@ use crate::value::Value;
 use rustc_codegen_ssa::debuginfo::type_names;
 use rustc_codegen_ssa::mir::debuginfo::{DebugScope, FunctionDebugContext, VariableKind};
 use rustc_codegen_ssa::traits::*;
-use rustc_data_structures::fx::FxHashMap;
-use rustc_data_structures::stable_hasher::Hash128;
 use rustc_data_structures::sync::Lrc;
 use rustc_hir::def_id::{DefId, DefIdMap};
 use rustc_index::IndexVec;
@@ -32,7 +31,9 @@ use rustc_middle::ty::{self, Instance, ParamEnv, Ty, TypeVisitableExt};
 use rustc_session::config::{self, DebugInfo};
 use rustc_session::Session;
 use rustc_span::symbol::Symbol;
-use rustc_span::{BytePos, Pos, SourceFile, SourceFileAndLine, SourceFileHash, Span};
+use rustc_span::{
+    BytePos, Pos, SourceFile, SourceFileAndLine, SourceFileHash, Span, StableSourceFileId,
+};
 use rustc_target::abi::Size;
 
 use libc::c_uint;
@@ -61,7 +62,7 @@ pub struct CodegenUnitDebugContext<'ll, 'tcx> {
     llcontext: &'ll llvm::Context,
     llmod: &'ll llvm::Module,
     builder: &'ll mut DIBuilder<'ll>,
-    created_files: RefCell<FxHashMap<Option<(Hash128, SourceFileHash)>, &'ll DIFile>>,
+    created_files: RefCell<UnordMap<Option<(StableSourceFileId, SourceFileHash)>, &'ll DIFile>>,
 
     type_map: metadata::TypeMap<'ll, 'tcx>,
     namespace_map: RefCell<DefIdMap<&'ll DIScope>>,