Debug Info: Don't print the display name and colon prefix for DEBUG_VALUE comments if the display name is empty

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184026 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/AsmPrinter/AsmPrinter.cpp b/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
index 69ff329..7f4ba7a 100644
--- a/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
+++ b/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
@@ -562,8 +562,11 @@
 
   // cast away const; DIetc do not take const operands for some reason.
   DIVariable V(const_cast<MDNode*>(MI->getOperand(2).getMetadata()));
-  if (V.getContext().isSubprogram())
-    OS << DISubprogram(V.getContext()).getDisplayName() << ":";
+  if (V.getContext().isSubprogram()) {
+    StringRef Name = DISubprogram(V.getContext()).getDisplayName();
+    if (!Name.empty())
+      OS << Name << ":";
+  }
   OS << V.getName() << " <- ";
 
   // Register or immediate value. Register 0 means undef.