klippy: Validate that options in the config file exist

Check that all options specified in the config file are valid.  This
catches possible typos and spelling errors in variable names that have
a default.

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>

klippy/klippy.py

@@ -44,6 +44,8 @@ class ConfigWrapper:
         if (default is not self.sentinel
             and not self.printer.fileconfig.has_option(self.section, option)):
             return default
+        self.printer.all_config_options[
+            (self.section.lower(), option.lower())] = 1
         try:
             return parser(self.section, option)
         except self.error, e:
@@ -79,6 +81,7 @@ class Printer:
         self.stats_timer = self.reactor.register_timer(self.stats)
         self.connect_timer = self.reactor.register_timer(
             self.connect, self.reactor.NOW)
+        self.all_config_options = {}
         self.state_message = message_startup
         self.debugoutput = self.dictionary = None
         self.fileconfig = None
@@ -118,6 +121,19 @@ class Printer:
             self.objects[oname].build_config()
         self.gcode.build_config()
         self.mcu.build_config()
+    def validate_config(self):
+        valid_sections = dict([(s, 1) for s, o in self.all_config_options])
+        for section in self.fileconfig.sections():
+            section = section.lower()
+            if section not in valid_sections:
+                raise ConfigParser.Error("Unknown config file section '%s'" % (
+                    section,))
+            for option in self.fileconfig.options(section):
+                option = option.lower()
+                if (section, option) not in self.all_config_options:
+                    raise ConfigParser.Error(
+                        "Unknown option '%s' in section '%s'" % (
+                            option, section))
     def connect(self, eventtime):
         try:
             self.load_config()
@@ -127,6 +143,7 @@ class Printer:
                 self.mcu.connect_file(self.debugoutput, self.dictionary)
             self.mcu.connect()
             self.build_config()
+            self.validate_config()
             self.gcode.set_printer_ready(True)
             self.state_message = "Running"
         except ConfigParser.Error, e: