Index: lib/Tooling/JSONCompilationDatabase.cpp
===================================================================
--- lib/Tooling/JSONCompilationDatabase.cpp
+++ lib/Tooling/JSONCompilationDatabase.cpp
@@ -62,7 +62,7 @@
   bool parseDoubleQuotedStringInto(std::string &String) {
     if (!next()) return false;
     while (*Position != '"') {
-      if (!skipEscapeCharacter()) return false;
+      if (!skipEscapeForDoubleQuote()) return false;
       String.push_back(*Position);
       if (!next()) return false;
     }
@@ -80,16 +80,18 @@
 
   bool parseFreeStringInto(std::string &String) {
     do {
-      if (!skipEscapeCharacter()) return false;
+      if (!skipEscapeForDoubleQuote()) return false;
       String.push_back(*Position);
       if (!next()) return false;
     } while (*Position != ' ' && *Position != '"' && *Position != '\'');
     return true;
   }
 
-  bool skipEscapeCharacter() {
+  bool skipEscapeForDoubleQuote() {
     if (*Position == '\\') {
-      return next();
+      if (next() && *Position == '"')
+        return true;
+      --Position;
     }
     return true;
   }
Index: unittests/Tooling/CompilationDatabaseTest.cpp
===================================================================
--- unittests/Tooling/CompilationDatabaseTest.cpp
+++ unittests/Tooling/CompilationDatabaseTest.cpp
@@ -90,10 +90,10 @@
 
   StringRef Directory1("//net/dir1");
   StringRef FileName1("file1");
-  StringRef Command1("command1");
+  StringRef Command1(R"(command1 -DFOO=\"1\\2\\\" \" -DBAR=\\)");
   StringRef Directory2("//net/dir2");
   StringRef FileName2("file1");
-  StringRef Command2("command1");
+  StringRef Command2(R"(command2 \"with spaces\")");
 
   std::vector<CompileCommand> Commands = getAllCompileCommands(
       ("[{\"directory\":\"" + Directory1 + "\"," +
@@ -103,13 +103,16 @@
              "\"command\":\"" + Command2 + "\","
              "\"file\":\"" + FileName2 + "\"}]").str(),
       ErrorMessage);
-  EXPECT_EQ(2U, Commands.size()) << ErrorMessage;
+  EXPECT_EQ(2u, Commands.size()) << ErrorMessage;
   EXPECT_EQ(Directory1, Commands[0].Directory) << ErrorMessage;
-  ASSERT_EQ(1u, Commands[0].CommandLine.size());
-  EXPECT_EQ(Command1, Commands[0].CommandLine[0]) << ErrorMessage;
+  ASSERT_EQ(3u, Commands[0].CommandLine.size());
+  EXPECT_EQ("command1", Commands[0].CommandLine[0]) << ErrorMessage;
+  EXPECT_EQ(R"(-DFOO=1\2" )", Commands[0].CommandLine[1]) << ErrorMessage;
+  EXPECT_EQ(R"(-DBAR=\)", Commands[0].CommandLine[2]) << ErrorMessage;
   EXPECT_EQ(Directory2, Commands[1].Directory) << ErrorMessage;
-  ASSERT_EQ(1u, Commands[1].CommandLine.size());
-  EXPECT_EQ(Command2, Commands[1].CommandLine[0]) << ErrorMessage;
+  ASSERT_EQ(2u, Commands[1].CommandLine.size());
+  EXPECT_EQ("command2", Commands[1].CommandLine[0]) << ErrorMessage;
+  EXPECT_EQ("with spaces", Commands[1].CommandLine[1]) << ErrorMessage;
 }
 
 static CompileCommand findCompileArgsInJsonDatabase(StringRef FileName,