Revert "[LLDB] Use the llvm microsoft demangler instead of the windows dbghelp api. NFC."

This reverts SVN r373144, as it changed the demangled output a little, see
http://lab.llvm.org:8011/builders/lldb-x64-windows-ninja/builds/9306.

llvm-svn: 373146

Author: mstorsjo

lldb/source/Core/Mangled.cpp

@@ -8,6 +8,13 @@
 
 #include "lldb/Core/Mangled.h"
 
+#if defined(_WIN32)
+#include "lldb/Host/windows/windows.h"
+
+#include <dbghelp.h>
+#pragma comment(lib, "dbghelp.lib")
+#endif
+
 #include "lldb/Core/RichManglingContext.h"
 #include "lldb/Utility/ConstString.h"
 #include "lldb/Utility/Log.h"
@@ -32,6 +39,25 @@
 #include <string.h>
 using namespace lldb_private;
 
+#if defined(_MSC_VER)
+static DWORD safeUndecorateName(const char *Mangled, char *Demangled,
+                                DWORD DemangledLength) {
+  static std::mutex M;
+  std::lock_guard<std::mutex> Lock(M);
+  return ::UnDecorateSymbolName(
+      Mangled, Demangled, DemangledLength,
+      UNDNAME_NO_ACCESS_SPECIFIERS |       // Strip public, private, protected
+                                           // keywords
+          UNDNAME_NO_ALLOCATION_LANGUAGE | // Strip __thiscall, __stdcall,
+                                           // etc keywords
+          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
+      );
+}
+#endif
+
 static inline Mangled::ManglingScheme cstring_mangling_scheme(const char *s) {
   if (s) {
     if (s[0] == '?')
@@ -192,16 +218,28 @@ void Mangled::SetValue(ConstString name) {
 
 // Local helpers for different demangling implementations.
 static char *GetMSVCDemangledStr(const char *M) {
-  char *demangled_cstr = llvm::microsoftDemangle(M, nullptr, nullptr, nullptr);
+#if defined(_MSC_VER)
+  const size_t demangled_length = 2048;
+  char *demangled_cstr = static_cast<char *>(::malloc(demangled_length));
+  ::ZeroMemory(demangled_cstr, demangled_length);
+  DWORD result = safeUndecorateName(M, demangled_cstr, demangled_length);
 
   if (Log *log = lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_DEMANGLE)) {
     if (demangled_cstr && demangled_cstr[0])
       LLDB_LOGF(log, "demangled msvc: %s -> \"%s\"", M, demangled_cstr);
     else
-      LLDB_LOGF(log, "demangled msvc: %s -> error", M);
+      LLDB_LOGF(log, "demangled msvc: %s -> error: 0x%lu", M, result);
   }
 
-  return demangled_cstr;
+  if (result != 0) {
+    return demangled_cstr;
+  } else {
+    ::free(demangled_cstr);
+    return nullptr;
+  }
+#else
+  return nullptr;
+#endif
 }
 
 static char *GetItaniumDemangledStr(const char *M) {