Correctly quote arguments in LLDB driver

[labath]

Summary

LLDB driver was simply tacking quotes around the strings in lldb commands, hoping that will work.
This changes it to properly escape quotes and backslashes.

[clayborg]

Looks good.

tools/driver/Driver.cpp

#ifdef _WIN32
         _close(fds[READ]); fds[READ] = -1;
 #else
         close(fds[READ]); fds[READ] = -1;
 #endif
     }
 
 }
 
+std::string
+EscapeString (std::string arg)
+{
+    std::string::size_type pos = 0;
+    while ((pos = arg.find_first_of("\"\\", pos)) != std::string::npos)
+    {
+        arg.insert (pos, 1, '\\');
+        pos += 2;
+    }
+    return '"' + arg + '"';
+}
+
 void
 Driver::MainLoop ()
 {
     if (::tcgetattr(STDIN_FILENO, &g_old_stdin_termios) == 0)
     {
         g_old_stdin_termios_is_valid = true;
         atexit (reset_stdin_termios);
     }
Driver::MainLoop ()
     // First source in the commands specified to be run before the file arguments are processed.
     WriteCommandsForSourcing(eCommandPlacementBeforeFile, commands_stream);
         
     const size_t num_args = m_option_data.m_args.size();
     if (num_args > 0)
     {
         char arch_name[64];
         if (m_debugger.GetDefaultArchitecture (arch_name, sizeof (arch_name)))
-            commands_stream.Printf("target create --arch=%s \"%s\"", arch_name, m_option_data.m_args[0].c_str());
+            commands_stream.Printf("target create --arch=%s %s", arch_name, EscapeString(m_option_data.m_args[0]).c_str());
         else
-            commands_stream.Printf("target create \"%s\"", m_option_data.m_args[0].c_str());
+            commands_stream.Printf("target create %s", EscapeString(m_option_data.m_args[0]).c_str());
 
         if (!m_option_data.m_core_file.empty())
         {
-            commands_stream.Printf(" --core \"%s\"", m_option_data.m_core_file.c_str());
+            commands_stream.Printf(" --core %s", EscapeString(m_option_data.m_core_file).c_str());
         }
         commands_stream.Printf("\n");
         
         if (num_args > 1)
         {
             commands_stream.Printf ("settings set -- target.run-args ");
             for (size_t arg_idx = 1; arg_idx < num_args; ++arg_idx)
-            {
-                const char *arg_cstr = m_option_data.m_args[arg_idx].c_str();
-                if (strchr(arg_cstr, '"') == NULL)
-                    commands_stream.Printf(" \"%s\"", arg_cstr);
-                else
-                    commands_stream.Printf(" '%s'", arg_cstr);
-            }
+                commands_stream.Printf(" %s", EscapeString(m_option_data.m_args[arg_idx]).c_str());
             commands_stream.Printf("\n");
         }
     }
     else if (!m_option_data.m_core_file.empty())
     {
-        commands_stream.Printf("target create --core \"%s\"\n", m_option_data.m_core_file.c_str());
+        commands_stream.Printf("target create --core %s\n", EscapeString(m_option_data.m_core_file).c_str());
     }
     else if (!m_option_data.m_process_name.empty())
     {
-        commands_stream.Printf ("process attach --name \"%s\"", m_option_data.m_process_name.c_str());
+        commands_stream.Printf ("process attach --name %s", EscapeString(m_option_data.m_process_name).c_str());
         
         if (m_option_data.m_wait_for)
             commands_stream.Printf(" --waitfor");
 
         commands_stream.Printf("\n");
 
     }
     else if (LLDB_INVALID_PROCESS_ID != m_option_data.m_process_pid)