Index: lib/Tooling/JSONCompilationDatabase.cpp
===================================================================
--- lib/Tooling/JSONCompilationDatabase.cpp
+++ lib/Tooling/JSONCompilationDatabase.cpp
@@ -16,7 +16,10 @@
 #include "clang/Tooling/CompilationDatabasePluginRegistry.h"
 #include "clang/Tooling/Tooling.h"
 #include "llvm/ADT/SmallString.h"
+#include "llvm/Support/Allocator.h"
+#include "llvm/Support/CommandLine.h"
 #include "llvm/Support/Path.h"
+#include "llvm/Support/StringSaver.h"
 #include <system_error>
 
 namespace clang {
@@ -113,8 +116,17 @@
 
 std::vector<std::string> unescapeCommandLine(
     StringRef EscapedCommandLine) {
+#if defined(LLVM_ON_WIN32)
+  llvm::BumpPtrAllocator Alloc;
+  llvm::StringSaver Saver(Alloc);
+  llvm::SmallVector<const char *, 64> T;
+  llvm::cl::TokenizeWindowsCommandLine(EscapedCommandLine, Saver, T);
+  std::vector<std::string> Result(T.begin(), T.end());
+  return Result;
+#else
   CommandLineArgumentParser parser(EscapedCommandLine);
   return parser.parse();
+#endif
 }
 
 class JSONCompilationDatabasePlugin : public CompilationDatabasePlugin {