Re: warning: rule never reduced because of conflicts: @3: /* empty */

[Hans Aberg]

At 12:44 +0200 2005/05/01, Eduardo Robles Elvira wrote:
> I've added some mid-rule actions, and I get a message like this one:
>
> $ bison --verbose -d lea.y
> lea.y: conflicts: 4 shift/reduce, 3 reduce/reduce
> lea.y:293.17-40: warning: rule never reduced because of conflicts: @3: /*
> empty */
> lea.y:317.17-40: warning: rule never reduced because of conflicts: @4: /*
> empty */
> lea.y:337.9-31: warning: rule never reduced because of conflicts: @5: /* empty
> */

If if you want an explanation of what that means, it means exactly 
what it says, namely, you have entered a grammar which is such that 
no parser input can cause those rules to be reduced. Normally that is 
an error in the grammar design. If you enter a mid-rule action, Bison 
will implement that by introducing an anonymous, empty rule, which 
thus is prone at generating conflicts, if not used cautiously.
--
  Hans Aberg