[antlr-interest] Dangling ELSE on Cobol

[Nilo Roberto C Paim]

Hi, folks.

I'm trying to parse Cobol sources using Antlr 3.4 (ANTLR Parser Generator
3.4 Jul 19, 2011 11:35:12. actually).

I'm stuck with the old dangling ELSE problem. Here the relevant piece of
code of my grammar that shows me the problem:


	command :
      		ifCmd
    		| 	initializeCmd
    		| 	moveCmd
    		| 	openCmd
    		;

	ifCmd:
    			IF expr command+ ( (ELSE)=> ELSE command+)?
    		;


I cannot put a terminator on the commands 'cause commands in Cobol may end
or with a '.' or with the following command. This is true including the
ifCmd itself.

The code above shows me the following messages:

warning(200): /SuperCobol/src/SC.g:229:13: 
Decision can match input such as "IF" using multiple alternatives: 1, 2
As a result, alternative(s) 2 were disabled for that input
 |---> IF expr command+ ( (ELSE)=> ELSE command+)?

warning(200): /SuperCobol/src/SC.g:229:13: 
Decision can match input such as "MOVE" using multiple alternatives: 1, 2
As a result, alternative(s) 2 were disabled for that input
 |---> IF expr command+ ( (ELSE)=> ELSE command+)?

warning(200): /SuperCobol/src/SC.g:229:13: 
Decision can match input such as "OPEN" using multiple alternatives: 1, 2
As a result, alternative(s) 2 were disabled for that input
 |---> IF expr command+ ( (ELSE)=> ELSE command+)?

warning(200): /SuperCobol/src/SC.g:229:13: 
Decision can match input such as "INITIALIZE" using multiple alternatives:
1, 2
As a result, alternative(s) 2 were disabled for that input
 |---> IF expr command+ ( (ELSE)=> ELSE command+)?

warning(200): /SuperCobol/src/SC.g:229:38: 
Decision can match input such as "IF" using multiple alternatives: 1, 2
As a result, alternative(s) 2 were disabled for that input
 |---> IF expr command+ ( (ELSE)=> ELSE command+)?

warning(200): /SuperCobol/src/SC.g:229:38: 
Decision can match input such as "MOVE" using multiple alternatives: 1, 2
As a result, alternative(s) 2 were disabled for that input
 |---> IF expr command+ ( (ELSE)=> ELSE command+)?

warning(200): /SuperCobol/src/SC.g:229:38: 
Decision can match input such as "OPEN" using multiple alternatives: 1, 2
As a result, alternative(s) 2 were disabled for that input
 |---> IF expr command+ ( (ELSE)=> ELSE command+)?

warning(200): /SuperCobol/src/SC.g:229:38: 
Decision can match input such as "INITIALIZE" using multiple alternatives:
1, 2
As a result, alternative(s) 2 were disabled for that input
 |---> IF expr command+ ( (ELSE)=> ELSE command+)?


8 warnings

Please, any hints?

Thanks in advance,
Nilo
Brazil