build-rpc: Fail if call is defined more than once

Signed-off-by: Michael Hanselmann <hansmi@google.com>
Reviewed-by: Iustin Pop <iustin@google.com>

autotools/build-rpc

@@ -187,6 +187,12 @@ def main():
     assert module.SINGLE == _SINGLE
     assert module.MULTI == _MULTI
 
+    dups = utils.FindDuplicates(itertools.chain(*map(lambda value: value.keys(),
+                                                     module.CALLS.values())))
+    if dups:
+      raise Exception("Found duplicate RPC definitions for '%s'" %
+                      utils.CommaJoin(sorted(dups)))
+
     for (clsname, calls) in module.CALLS.items():
       _WriteBaseClass(sw, clsname, calls.values())