[antlr-interest] Generate AST from C runtime

[Jim Idle]

Compile the runtime in debug mode and single step - explained in the API
docs.

Download the example tar and find the tree example in C. This shows that
you get a pointer (pANTLR3_BASE_TREE) and the super pointer of such a node
is pANTLR3_COMMON_TREE. The code in the runtime that generates a .dot file
is a good example of how to walk the tree. This is also explained in the
API docs. This is also talked about many times in antlr.markmail.org


Jim




> -----Original Message-----
> From: antlr-interest-bounces at antlr.org [mailto:antlr-interest-
> bounces at antlr.org] On Behalf Of Sergiy Dubovik
> Sent: Sunday, March 25, 2012 9:31 AM
> To: AN TLR
> Subject: Re: [antlr-interest] Generate AST from C runtime
>
> Uff, sorry for posting unfinished email. Tab and space have special
> meaning in browser.
>
> Could someone help me to generate AST from a grammar using C with a
> minimum amount of C code?I just want to get a pointer to an AST root. I
> don't need tree walker. I have a grammar which generates nice AST in
> AntlrWorks. Can I have the same from C? Isn't it so that Antlr
> generates AST if I specify options=AST;?
>
>     pANTLR3_UINT8 fileName = (pANTLR3_UINT8) "example.rpp";
> >
> >     pANTLR3_INPUT_STREAM input = antlr3FileStreamNew(fileName,
> > ANTLR3_ENC_8BIT);
> >
> >     pRppLexer lexer = RppLexerNew(input);
> >
> >     pANTLR3_COMMON_TOKEN_STREAM tokenStream =
> > antlr3CommonTokenStreamSourceNew(ANTLR3_SIZE_HINT,
> > TOKENSOURCE(lexer));
> >
> >     pRppParser parser = RppParserNew(tokenStream);
> >
> >      RppParser_prog_return prog;
> >
> >     prog = parser->prog(parser);
> >
> >
> I found that prog.tree should point to a root AST and it's not NULL,
> however when I try to get token, it returns NULL.
> Some months ago, I think I was getting proper pointer but now for some
> reason (I updated antlr) it doesn't work anymore. C Runtime API makes
> it very difficult to debug anything :(
>
> Thanks.
>
> br,
> Sergiy
>
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