contrib/fsm-to-dot: warn about identically named FSMs

FSMs with identical names confuse the script, so at least warn about them.
IMHO we should also have different names for each FSM, so not bothering to make
the script safe against identical naming.

Change-Id: I4fe7e85d2fdf23e2ba964f3b47be1954edc63cef

contrib/fsm-to-dot.py

@@ -262,7 +262,7 @@ class Fsm:
   def __str__(fsm):
     return 'Fsm(%r,%r)' % (fsm.struct_name, fsm.from_file)
 
-  def parse_states(fsm, src):
+  def parse_states(fsm, src, c_file):
     state = None
     started = None
 
@@ -274,6 +274,15 @@ class Fsm:
     for line in lines:
       state_name = state_starts(line)
       if state_name:
+        state = fsm.find_state_by_name(state_name)
+        if state is not None:
+          if c_file is fsm.from_file:
+            print('ERROR: fsm %r has multiple definitions of state %r' % (fsm, state_name))
+          else:
+            print('ERROR: it appears two FSMs with identical name %r exist in %r and %r'
+                  % (fsm.struct_name, fsm.from_file, c_file))
+          state = None
+          continue
         state = State()
         fsm.states.append(state)
         started = None
@@ -664,7 +673,7 @@ class CFile():
       states_struct_name = m.group(1)
       for fsm in fsms:
         if states_struct_name == fsm.states_struct_name:
-          fsm.parse_states(c_file.extract_block('{', '}', m.start()))
+          fsm.parse_states(c_file.extract_block('{', '}', m.start()), c_file)
 
   def parse_functions(c_file):
     funcs = {}
@@ -787,6 +796,14 @@ fsms = []
 for c_file in c_files:
   fsms.extend(c_file.find_fsms())
 
+for fsm1 in fsms:
+  for fsm2 in fsms:
+    if fsm1 is fsm2:
+      continue
+    if fsm1.states_struct_name == fsm2.states_struct_name:
+      print('ERROR: two distinct FSMs share the same states-struct name: %r and %r both use %r'
+            % (fsm1, fsm2, fsm1.states_struct_name))
+
 for c_file in c_files:
   c_file.find_fsm_states(fsms)
   c_file.find_event_sources(fsms)