Bug 850380 - Ensure xpidl Makefile is regenerated properly; r=glandium

config/makefiles/xpidl/Makefile.in

@@ -11,6 +11,7 @@ include $(DEPTH)/config/autoconf.mk
 
 SUPPRESS_DEFAULT_RULES := 1
 STANDALONE_MAKEFILE := 1
+NO_MAKEFILE_RULE := 1
 
 include $(topsrcdir)/config/rules.mk
 

python/mozbuild/mozbuild/backend/recursivemake.py

@@ -442,6 +442,11 @@ class RecursiveMakeBackend(CommonBackend):
         self._update_from_avoid_write(result)
         self.summary.managed_count += 1
 
+        # The Makefile can't regenerate itself because of custom substitution.
+        # We need to list it here to ensure changes cause regeneration.
+        self.backend_input_files.add(os.path.join(self.environment.topsrcdir,
+            'config', 'makefiles', 'xpidl', 'Makefile.in'))
+
     def _process_program(self, program, backend_file):
         backend_file.write('PROGRAM = %s\n' % program)