[antlr-interest] ANTLR v3.0.1: Regression from ANTLR v2:?? left recusrsive grammar detected while it's not.

[Johannes Luber]

Francis ANDRE schrieb:
> Hi ANTLR's
> 
> Upon migration from ANTLR v2 to ANTLR v3 on the following snippet
> 
> grammar Cobol;
> tokens {  DOT='DOT';    SECTION='SECTION';    IDENT='IDENT';}
> debut    :    section;
> 
> section returns[PROCEDURE_SECTION section = null]
> @init {String s;}  :  section = sectionHeader DOT ;

You have three section-s here - one for the rule, one for return and one 
as label. ANTLR gets confused there. Rename at least the label and the 
return parameter.

Johannes
> 
> sectionHeader returns[PROCEDURE_SECTION section = null]
>    :    IDENT SECTION    { section = $IDENT.getText(); };
> 
> 
> got this error: [17:39:46] error(211): Cobol.g:2941:6: [fatal] rule 
> section has non-LL(*) decision due to recursive rule invocations 
> reachable from alts 1,2.  Resolve by left-factoring or using syntactic 
> predicates or using backtrack=true option.
> 
> IMHO,  in no way the 'section = ' is a left recursive invocation of the 
> section rule, but just the assignment if the result of sectionHeader to 
> the PROCEDURE_SECTION section.
> 
> What's yours?
> 
> FA
> 
> 
> 
>