[antlr-interest] How do I find what Antlr is really telling me?

[Alan Lehotsky]

I've massaged the PLSQL.g grammar which has a number of rules of the form:

select_statement :  SELECT swallow_to_semi;

update_statement : UPDATE swallow_to_semi;

...

swallow_to_semi :  ~( SEMI )+


These all seem to do the right thing, but I get a warning from Antlr that 
says

warning(200): plsql.g:815:39; Decision can match input such as 
"{BLOCK..DIVIDE, OR..END, BODY..RETURN, TEMPORARY..INOUT_, 
TRANSACTION..VERTBAR}" using multiple alternatives: 1, 2
As a result, alternative(s) 2 were disabled for that input


But line 815 is in fact the swallow_to_semi rule, so it must have subsumed 
this rule into some other rule with multiple selections.


  
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