1 files changed, 37 insertions, 4 deletions
diff --git a/llvm/lib/DebugInfo/Symbolize/Symbolize.cpp b/llvm/lib/DebugInfo/Symbolize/Symbolize.cpp
index 389a8f743e9..8e1852bcf8e 100644
--- a/llvm/lib/DebugInfo/Symbolize/Symbolize.cpp
+++ b/llvm/lib/DebugInfo/Symbolize/Symbolize.cpp
@@ -35,6 +35,19 @@
 #include <cassert>
 #include <cstring>
 
+#if defined(_MSC_VER)
+#include <Windows.h>
+
+// This must be included after windows.h.
+#include <DbgHelp.h>
+#pragma comment(lib, "dbghelp.lib")
+
+// Windows.h conflicts with our COFF header definitions.
+#ifdef IMAGE_FILE_MACHINE_I386
+#undef IMAGE_FILE_MACHINE_I386
+#endif
+#endif
+
 namespace llvm {
 namespace symbolize {
 
@@ -511,11 +524,31 @@ LLVMSymbolizer::DemangleName(const std::string &Name,
                              const SymbolizableModule *DbiModuleDescriptor) {
   // We can spoil names of symbols with C linkage, so use an heuristic
   // approach to check if the name should be demangled.
-  // MSVC C++ mangled symbols start with '?', while itanium mangled ones
-  // start with _Z.
-  if (Name.substr(0, 2) == "_Z" || (!Name.empty() && Name.front() == '?'))
-    return demangle(Name);
+  if (Name.substr(0, 2) == "_Z") {
+    int status = 0;
+    char *DemangledName = itaniumDemangle(Name.c_str(), nullptr, nullptr, &status);
+    if (status != 0)
+      return Name;
+    std::string Result = DemangledName;
+    free(DemangledName);
+    return Result;
+  }
 
+#if defined(_MSC_VER)
+  if (!Name.empty() && Name.front() == '?') {
+    // Only do MSVC C++ demangling on symbols starting with '?'.
+    char DemangledName[1024] = {0};
+    DWORD result = ::UnDecorateSymbolName(
+        Name.c_str(), DemangledName, 1023,
+        UNDNAME_NO_ACCESS_SPECIFIERS |       // Strip public, private, protected
+            UNDNAME_NO_ALLOCATION_LANGUAGE | // Strip __thiscall, __stdcall, etc
+            UNDNAME_NO_THROW_SIGNATURES |    // Strip throw() specifications
+            UNDNAME_NO_MEMBER_TYPE | // Strip virtual, static, etc specifiers
+            UNDNAME_NO_MS_KEYWORDS | // Strip all MS extension keywords
+            UNDNAME_NO_FUNCTION_RETURNS); // Strip function return types
+    return (result == 0) ? Name : std::string(DemangledName);
+  }
+#endif
   if (DbiModuleDescriptor && DbiModuleDescriptor->isWin32Module())
     return std::string(demanglePE32ExternCFunc(Name));
   return Name;