Adding line Nubers to Listener

[Bill Dickenson]

I have read the documentation on how to add the scope to the listener and I am wondering if I can do the same thing for line number. I am working on a project that requires traceability back to the line number, not just the artifact !

Has anyone done this and would be willing to share.

Thanks

[David Whitten]

Doesn't ANTLR already have a way to access the line number and the column number ?

Maybe its in the lexer ?

Thanks,

Dave Whitten

713-870-3834

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[Norman Dunbar]

Hi Bill,

I might have misunderstood your question, but the following is what I
did in an old app of mine - but it works to give me the line numbers and
column numbers for the input file correctly.

It might not be the best or most efficient way, but, from an old posting
of mine on this list ...


I've done this in my utility to parse an Oracle tnsnames.ora file. The
source is on GitHub here
https://github.com/NormanDunbar/Tnsnames_checker the relevant part being:

//----------------------------------------------------------------
// EVERY RULE
//----------------------------------------------------------------
// As we enter every rule, extract the line and column positions.
// Use them to build a location string for the start of this rule.
//----------------------------------------------------------------
@Override
public void enterEveryRule(ParserRuleContext ctx)
{
Token startToken = ctx.getStart();
if (startToken != null)
{
// Lines number from 1.
this.lineNumber = startToken.getLine();

// Characters from zero. Adjust.
this.charPosition = 1 + startToken.getCharPositionInLine();
}
else
{
// Just in case Token can ever be null.
this.lineNumber = 0;
this.charPosition = 0;
}

// Build a location string for error messages etc.
this.whereAmI = "\tLine " + lineNumber + ":" + charPosition + " ";
}

Apologies for the Java - I'm not a Java developer! Formatting might also
have been "amended" by the posting process.

Lines count from 1 but characters on the line count from 0 with ANTLR
(or is it Java?)

HTH

Disclaimer: I'm not a compiler writer, nor do I play one on TV.


Cheers,
Norm.