Debug info: use the file a typedef is defined in as its decl_file instead

of the current compilation unit.
As a side effect this enables many more LTO uniquing opportunities.

This reapplies r199757 with a better testcase.

llvm-svn: 199760

2 files changed, 15 insertions, 2 deletions

diff --git a/clang/lib/CodeGen/CGDebugInfo.cpp b/clang/lib/CodeGen/CGDebugInfo.cpp
index faf6fbba1a4..ff17a03dccd 100644
--- a/clang/lib/CodeGen/CGDebugInfo.cpp
+++ b/clang/lib/CodeGen/CGDebugInfo.cpp
@@ -739,14 +739,16 @@ llvm::DIType CGDebugInfo::CreateType(const TypedefType *Ty, llvm::DIFile Unit) {
     return llvm::DIType();
   // We don't set size information, but do specify where the typedef was
   // declared.
-  unsigned Line = getLineNumber(Ty->getDecl()->getLocation());
+  SourceLocation Loc = Ty->getDecl()->getLocation();
+  llvm::DIFile File = getOrCreateFile(Loc);
+  unsigned Line = getLineNumber(Loc);
   const TypedefNameDecl *TyDecl = Ty->getDecl();
 
   llvm::DIDescriptor TypedefContext =
     getContextDescriptor(cast<Decl>(Ty->getDecl()->getDeclContext()));
 
   return
-    DBuilder.createTypedef(Src, TyDecl->getName(), Unit, Line, TypedefContext);
+    DBuilder.createTypedef(Src, TyDecl->getName(), File, Line, TypedefContext);
 }
 
 llvm::DIType CGDebugInfo::CreateType(const FunctionType *Ty,
diff --git a/clang/test/CodeGen/debug-info-typedef.c b/clang/test/CodeGen/debug-info-typedef.c
new file mode 100644
index 00000000000..51ebcc4d874
--- /dev/null
+++ b/clang/test/CodeGen/debug-info-typedef.c
@@ -0,0 +1,11 @@
+// RUN: %clang_cc1 -emit-llvm -g -I%p %s -o - | FileCheck %s
+// Test that the location of the typedef points to the header file.
+#line 1 "a.c"
+#line 2 "b.h"
+typedef int MyType;
+#line 2 "a.c"
+
+MyType a;
+
+// CHECK: metadata ![[HEADER:[0-9]+]], null, metadata !"MyType"{{.*}} ; [ DW_TAG_typedef ] [MyType] [line 2, size 0, align 0, offset 0] [from int]
+// CHECK: ![[HEADER]] = metadata !{metadata !"b.h",