Index: clang/include/clang/Basic/TargetInfo.h
===================================================================
--- clang/include/clang/Basic/TargetInfo.h
+++ clang/include/clang/Basic/TargetInfo.h
@@ -1388,7 +1388,7 @@
   virtual void setAuxTarget(const TargetInfo *Aux) {}
 
   /// Whether target allows debuginfo types for decl only variables.
-  virtual bool allowDebugInfoForExternalVar() const { return false; }
+  virtual bool allowDebugInfoForExternalVar() const { return true; }
 
 protected:
   /// Copy type and layout related info.
Index: clang/lib/CodeGen/CGDebugInfo.cpp
===================================================================
--- clang/lib/CodeGen/CGDebugInfo.cpp
+++ clang/lib/CodeGen/CGDebugInfo.cpp
@@ -4619,6 +4619,8 @@
   assert(CGM.getCodeGenOpts().hasReducedDebugInfo());
   if (D->hasAttr<NoDebugAttr>())
     return;
+  if (DebugKind < clang::codegenoptions::FullDebugInfo)
+    return;
 
   auto Align = getDeclAlignIfRequired(D, CGM.getContext());
   llvm::DIFile *Unit = getOrCreateFile(D->getLocation());
Index: clang/test/CodeGen/debug-info-extern-variable-basic.c
===================================================================
--- /dev/null
+++ clang/test/CodeGen/debug-info-extern-variable-basic.c
@@ -0,0 +1,10 @@
+// RUN: %clang -emit-llvm -S -g -fstandalone-debug %s -o - | FileCheck %s
+
+extern int i;
+int foo() {
+  extern int j;
+  return i+j;
+}
+
+// CHECK: distinct !DIGlobalVariable(name: "i"
+// CHECK: distinct !DIGlobalVariable(name: "j"
Index: clang/test/CodeGen/debug-info-extern-variable-unused.c
===================================================================
--- /dev/null
+++ clang/test/CodeGen/debug-info-extern-variable-unused.c
@@ -0,0 +1,10 @@
+// RUN: %clang -emit-llvm -S -g -fstandalone-debug %s -o - | FileCheck %s
+
+extern int i;
+int foo() {
+  extern int j;
+  return 0;
+}
+
+// CHECK-NOT: distinct !DIGlobalVariable(name: "i"
+// CHECK-NOT: distinct !DIGlobalVariable(name: "j"