llvm-symbolizer: don't always run demangler on global object names

llvm-svn: 192781
diff --git a/llvm/tools/llvm-symbolizer/LLVMSymbolize.cpp b/llvm/tools/llvm-symbolizer/LLVMSymbolize.cpp
index 45c8664..320ab3f 100644
--- a/llvm/tools/llvm-symbolizer/LLVMSymbolize.cpp
+++ b/llvm/tools/llvm-symbolizer/LLVMSymbolize.cpp
@@ -196,7 +196,7 @@
   if (Opts.UseSymbolTable) {
     if (ModuleInfo *Info = getOrCreateModuleInfo(ModuleName)) {
       if (Info->symbolizeData(ModuleOffset, Name, Start, Size) && Opts.Demangle)
-        Name = DemangleName(Name);
+        Name = DemangleGlobalName(Name);
     }
   }
   std::stringstream ss;
@@ -436,5 +436,11 @@
 #endif
 }
 
+std::string LLVMSymbolizer::DemangleGlobalName(const std::string &Name) {
+  // We can spoil names of globals with C linkage, so use an heuristic
+  // approach to check if the name should be demangled.
+  return (Name.substr(0, 2) == "_Z") ? DemangleName(Name) : Name;
+}
+
 } // namespace symbolize
 } // namespace llvm