llvm-symbolizer: Fix FRAME handling of missing AT_name.

Summary:
llvm-symbolizer protocol is empty string means end-of-output.
Do not emit empty string when a function or a variable do not have a
name for any reason. Emit "??".

Reviewers: pcc, vitalybuka, jdoerfert

Subscribers: srhines, hiraditya, rupprecht, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D70626

1 files changed, 13 insertions, 2 deletions

diff --git a/llvm/lib/DebugInfo/Symbolize/DIPrinter.cpp b/llvm/lib/DebugInfo/Symbolize/DIPrinter.cpp
index b1a80cbc458..2f3a2500c29 100644
--- a/llvm/lib/DebugInfo/Symbolize/DIPrinter.cpp
+++ b/llvm/lib/DebugInfo/Symbolize/DIPrinter.cpp
@@ -118,21 +118,32 @@ DIPrinter &DIPrinter::operator<<(const DIGlobal &Global) {
 }
 
 DIPrinter &DIPrinter::operator<<(const DILocal &Local) {
-  OS << Local.FunctionName << '\n';
-  OS << Local.Name << '\n';
+  if (Local.FunctionName.empty())
+    OS << "??\n";
+  else
+    OS << Local.FunctionName << '\n';
+
+  if (Local.Name.empty())
+    OS << "??\n";
+  else
+    OS << Local.Name << '\n';
+
   if (Local.DeclFile.empty())
     OS << "??";
   else
     OS << Local.DeclFile;
   OS << ':' << Local.DeclLine << '\n';
+
   if (Local.FrameOffset)
     OS << *Local.FrameOffset << ' ';
   else
     OS << "?? ";
+
   if (Local.Size)
     OS << *Local.Size << ' ';
   else
     OS << "?? ";
+
   if (Local.TagOffset)
     OS << *Local.TagOffset << '\n';
   else