[clang] [serialization] no transitive decl change (PR #92083)

[Jan Svoboda via cfe-commits]

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@@ -7802,20 +7800,31 @@ Decl *ASTReader::GetDecl(GlobalDeclID ID) {
 
 LocalDeclID ASTReader::mapGlobalIDToModuleFileGlobalID(ModuleFile &M,
                                                        GlobalDeclID GlobalID) {
-  DeclID ID = GlobalID.get();
-  if (ID < NUM_PREDEF_DECL_IDS)
+  if (GlobalID.get() < NUM_PREDEF_DECL_IDS)
+    return LocalDeclID(GlobalID.get());
+
+  if (!M.ModuleOffsetMap.empty())
+    ReadModuleOffsetMap(M);
+
+  ModuleFile *Owner = getOwningModuleFile(GlobalID);
+  DeclID ID = GlobalID.getLocalDeclIndex();
+
+  if (Owner == &M) {
+    ID += NUM_PREDEF_DECL_IDS;
     return LocalDeclID(ID);
+  }
 
-  GlobalDeclMapType::const_iterator I = GlobalDeclMap.find(GlobalID);
-  assert(I != GlobalDeclMap.end() && "Corrupted global declaration map");
-  ModuleFile *Owner = I->second;
+  uint64_t OrignalModuleFileIndex = 0;
+  for (unsigned I = 0; I < M.DependentModules.size(); I++)
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jansvoboda11 wrote:

I just now noticed the name `DependentModules` (introduced in #86912) sounds like exactly the opposite of what this member represents. Can we rename this to `TransitiveImports` (or something similar) in a prep patch to clarify the semantics here?

https://github.com/llvm/llvm-project/pull/92083