Re: [cdt-dev] Apparent incorrect C parsing

[Andrew Niefer <aniefer@xxxxxxxxxx>]

Hi Jason,
I believe that the problem you're describing is an instance of bug 77154,
where we are allowing a postfix expression with an empty LHS.
Which results in cast expression that don't make sense.
I would suggest adding your comments to that bug.  Also, there is currently
a patch attached to that bug which you might want to try to see if it fixes
your problem.

-Andrew

cdt-dev-admin@xxxxxxxxxxx wrote on 11/01/2004 10:54:25 AM:

> john,
>
> I'll put the bug in today, apologies for the delay.
>
> In the meantime I think I discovered another problem, let me know what
> you think.  Parsing the following program
>
> int main(int argc, char *argv[])
> {
>    unsigned long l = 0;
>    char *c;
>
>    l |= ((unsigned long)(*((c)++)))<<24;
> }
>
> results in the sub-expression (c)++ being a cast of ++ with the type
> (c).
>
> jason
>
>
>
> On Oct 28, 2004, at 15:52, John Camelon wrote:
>
> >
> > What you have found, is most likely a bug.
> > When an expression is created, some semantic validation is done on the
> > expression to ensure that the operand types adhere to the spirit of
> > the operation.
> > You have found a point where this is not done properly.  It most
> > likely had not been detected up to this point as the only symptom is
> > an IProblem or missed reference as compared to an ambiguity in the
> > grammar.
> >
> > Please raise a defect.
> > Thanks
> > JohnC
> >  www.eclipse.org/cdt
> >
> > cdt-dev-admin@xxxxxxxxxxx wrote on 10/28/2004 04:20:27 AM:
> >
> >  > Hi All,
> >  >
> >  > Maybe I have done something horribly wrong, but I wanted to ask if
> >  > anyone has seen this problem before.  I see that it is possible to
> > have
> >  > the parser complete successfully a parse, but for the C file to be
> >  > incorrect.
> >  >
> >  > Here is the example it works on, but shouldn't
> >  >
> >  > int main(int argc, char *argv[])
> >  > {
> >  >    m = 10;
> >  >    return 0;
> >  > }
> >  >
> >  > however the following fails to parser correctly as expected, but the
> >  > problem is not detected until the 'i' is reached.
> >  >
> >  > int main(int argc, char *argv[])
> >  > {
> >  >    m = i;
> >  >    return 0;
> >  > }
> >  >
> >  > I see that in the expression parser after trying to parse a cast,
> > which
> >  > is the last thing it tries a new name is created, but there does not
> >  > appear to be a check that the name has been declared in the scope.
> >  >
> >  > Here is another example that should cause a problem, but doesn't
> >  >
> >  > int main(int argc, char *argv[])
> >  > {
> >  >          switch(loopvar)
> >  >          {
> >  >             int k = 2;
> >  >          default:
> >  >             printf("k = \n", k);
> >  >             break;
> >  >          }
> >  >    return k;
> >  > }
> >  >
> >  > Here there are two issues (initialiser for k) and k is not in scope
> > in
> >  > the return statement.
> >  >
> >  > I'm using the latest version of the head of the cvs and i have been
> >  > using ParserMode.COMPLETE_PARSE.
> >  >
> >  > Any ideas as to what I am doing or I am assuming that I shouldn't
> > be?
> >  >
> >  > Jason
> >  >
> >  > _______________________________________________
> >  > cdt-dev mailing list
> >  > cdt-dev@xxxxxxxxxxx
> >  > http://dev.eclipse.org/mailman/listinfo/cdt-dev
>
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