[antlr-interest] Problem generating the Java parser for Oracle PL/SQL grammar

[Javier Luis Cánovas Izquierdo]

Hi Andrew!

Thanks for the advices. They have been useful for improving my grammar
definition.

I had to modify the antlr ant task to execute the antlr parser tool
(memory aspects) and some elements in the grammar definition (as you
told in your mail): options section, members section, and some grammar
rules. The only thing I have done different is the definition of rules
for keyword. I use the ANTLRNoCaseFileStream Java class defined in
http://www.antlr.org/wiki/pages/viewpage.action?pageId=1782. This way,
all keywords can be specified in uppercase, lowercase or both, they
will be recognized in uppercase in the lexer so these rules only work
with uppercase words.

Regards!

2008/11/10 Andrew Haritonkin <thikone at gmail.com>:
> Hi, Javier Luis Cánovas Izquierdo!
>
> You don't need so much memory for my grammar, really :) 256Mb is
> enough for ANTLR v3.1.1. Well I use 512Mb actually...
>
> You need to change one rule though, to make it compatible with ANTLR 3.1.x:
>
> column_spec
>   :       sql_identifier ( DOT sql_identifier )*;
>
> For some reason, ANTLR 3.1.x cannot compile it, raising a error:
>
> error(206): PLSQL3.g:791:4: Alternative 2: after matching input such
> as ID DOT ID DOT ID DOT ID DOT decision cannot predict what comes next
> due to recursion overflow to expr_add from sql_expression and to
> expr_mul from expr_add
>
> While with ANTLR 3.0.1 it was compiling just fine... Anyway, replace
> it with this:
>
> column_spec
>   :       sql_identifier ( DOT sql_identifier ( DOT sql_identifier )? )?;
>
> And regarding Java target - there is not much you need to change, only
> members declaration and some gate predicates:
>
> options {
>       language=Java;
>       k=*;
>       backtrack=true;
>       memoize=true;
>       output=AST;
> }
>
> @members {
>   private boolean is_sql = false;
> }
>
> and all parser rules for keywords should like like this:
>
> keyA : {PLSQL3Parser.this.input.LT(1).getText().toUpperCase().equals("A")}? ID;
>
> Here I have to reference parser class, because this predicate can be
> also embedded in DFA, but there only token type stream is available,
> LT(1) returns token ID, integer... not very convenient. Gonna write
> separate topic for this, eventually.
>
> I also use Java target, mainly to debug the grammar in ANTLRWorks -
> works perfectly.
>
> Andrew
>
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>



-- 
Javier Luis Cánovas Izquierdo
http://zirrus.es
zirrus at gmail.com