4 files changed, 12 insertions, 2 deletions
diff --git a/clang/lib/CodeGen/CGDebugInfo.cpp b/clang/lib/CodeGen/CGDebugInfo.cpp
index ae1f5e7ecfa..72ddf4efc7c 100644
--- a/clang/lib/CodeGen/CGDebugInfo.cpp
+++ b/clang/lib/CodeGen/CGDebugInfo.cpp
@@ -3453,6 +3453,12 @@ CGDebugInfo::getOrCreateNameSpace(const NamespaceDecl *NSDecl) {
   return NS;
 }
 
+void CGDebugInfo::setDwoId(uint64_t Signature) {
+  assert(TheCU && "no main compile unit");
+  TheCU->setDWOId(Signature);
+}
+
+
 void CGDebugInfo::finalize() {
   // Creating types might create further types - invalidating the current
   // element and the size(), so don't cache/reference them.
diff --git a/clang/lib/CodeGen/CGDebugInfo.h b/clang/lib/CodeGen/CGDebugInfo.h
index 8cad0c16b76..ddc90bfa67d 100644
--- a/clang/lib/CodeGen/CGDebugInfo.h
+++ b/clang/lib/CodeGen/CGDebugInfo.h
@@ -276,6 +276,9 @@ public:
 
   void finalize();
 
+  /// Set the main CU's DwoId field to \p Signature.
+  void setDwoId(uint64_t Signature);
+
   /// When generating debug information for a clang module or
   /// precompiled header, this module map will be used to determine
   /// the module of origin of each Decl.
diff --git a/clang/lib/CodeGen/ObjectFilePCHContainerOperations.cpp b/clang/lib/CodeGen/ObjectFilePCHContainerOperations.cpp
index 310e374e348..8ceaf7cb3a0 100644
--- a/clang/lib/CodeGen/ObjectFilePCHContainerOperations.cpp
+++ b/clang/lib/CodeGen/ObjectFilePCHContainerOperations.cpp
@@ -142,7 +142,6 @@ public:
     CodeGenOpts.ThreadModel = "single";
     CodeGenOpts.DebugTypeExtRefs = true;
     CodeGenOpts.setDebugInfo(CodeGenOptions::FullDebugInfo);
-    CodeGenOpts.SplitDwarfFile = OutputFileName;
   }
 
   ~PCHContainerGenerator() override = default;
@@ -201,6 +200,7 @@ public:
 
     M->setTargetTriple(Ctx.getTargetInfo().getTriple().getTriple());
     M->setDataLayout(Ctx.getTargetInfo().getDataLayoutString());
+    Builder->getModuleDebugInfo()->setDwoId(Buffer->Signature);
 
     // Finalize the Builder.
     if (Builder)
diff --git a/clang/lib/Serialization/GeneratePCH.cpp b/clang/lib/Serialization/GeneratePCH.cpp
index 08660bc9675..9de2fdb75a0 100644
--- a/clang/lib/Serialization/GeneratePCH.cpp
+++ b/clang/lib/Serialization/GeneratePCH.cpp
@@ -48,7 +48,8 @@ void PCHGenerator::HandleTranslationUnit(ASTContext &Ctx) {
 
   // Emit the PCH file to the Buffer.
   assert(SemaPtr && "No Sema?");
-  Writer.WriteAST(*SemaPtr, OutputFile, Module, isysroot, hasErrors);
+  Buffer->Signature =
+      Writer.WriteAST(*SemaPtr, OutputFile, Module, isysroot, hasErrors);
 
   Buffer->IsComplete = true;
 }