Module Debugging: Use the clang module signature as the module's dwo_id

when building a module. Clang already records the module signature when
building a skeleton CU to reference a clang module.

Matching the id in the skeleton with the one in the module allows a DWARF
consumer to verify that they found the correct version of the module
without them needing to know about the clang module format.

llvm-svn: 248345

1 files changed, 2 insertions, 1 deletions

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;
 }