[antlr-interest] [C-target] Child-parent relationship

[Дмитрий Ильин]

I took "simplecTreeParser" example, antlr-3.2 and libantlr3c-3.2 ( + ms vs
2005). After generating AST (after "SimpleCAST = psr->program(psr);") and
after checking count of errors I inserted this code:

correctParent = SimpleCAST.tree;
child = (pANTLR3_BASE_TREE)(correctParent->getChild(correctParent, 0));
suggestedParent = (pANTLR3_BASE_TREE)(child->getParent(child));
if (correctParent == suggestedParent)
printf("\n\nCorrect\n\n");
 else
printf("\n\nIncorrect\n\n");

So after execution "Incorrect" was printed. Because
((pANTLR3_COMMON_TREE)child->super)->parent had NULL. It seems to me it
happens due to error in implementaion of "setParent" function in
antlr3commontree.c. I also used Python target and python's "setParent" has
diffrent logic.

Dmitry Ilyin


Take a look at antlr.markmail.org for other examples but where are you
>
trying to get the parent, in the parser before you have built the AST (it
>
sounds like this) or in the tree walker? You should not need to change any
>
of the runtime functions; you are probably just making them do things that
>
are going to get done anyway at the end of the rule. Look at the generated
>
code for ways to traverse the tree. I suppose there could be a bug, but ut
>
seems a bit unlikely at this point.
>

> Jim
>

> > -----Original Message-----
>
> From: antlr-interest-bounces at antlr.org [mailto:antlr-interest-
>
> bounces at antlr.org] On Behalf Of ??????? ?????
>
> Sent: Wednesday, April 27, 2011 11:15 AM
>
> To: antlr-interest at antlr.org
>
> Subject: [antlr-interest] [C-target] Child-parent relationship
>
>
>
> Sorry, I have no exp in using mailing lists, so I hope i'm doing right.
>
> I'm trying to get parent of AST node, but "getParent" function returns
>
> 0x00000001c address. Because pointer to parent of the node's super is
>
> equal to NULL. But when I've changed functions "addChild" and
>
> "setParent" all child-parent relationships become correct.
>
> Dmitry Ilyin
>
>
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