Re: [PATCH] PR59170 make pretty printers check for singular iterators
Jan Kratochvil <[email protected]>
| Newsgroups | gmane.comp.gcc.patches,gmane.comp.gcc.libstdc++.devel,gmane.comp.gdb.devel |
|---|---|
| Message-ID | <[email protected]> |
On Fri, 16 Dec 2016 14:17:32 +0100, Jonathan Wakely wrote:
> On 16/12/16 14:06 +0100, Jan Kratochvil wrote:
> > (gdb) p bb.c.d
> > $4 = (D &) @0x601028: {e = 0x601060 <ee>}
>
> Wat?
>
> bb.c.d is not a valid expression.
>
> B::c is a pointer, it should be bb.c->d
>
> Is it GDB policy to make invalid expressions like that "work"?
Yes, this is a GDB extension from the times of plain C. In C++ it became
a problem. That was not the topic of this example for the initial
dereferencing operator.
> I had no idea this even worked, I'd have used bb.c->d.e->i because
> that's the correct expression for accessing that variable.
There was a plan to make the 'compile' project backward compatible with these
confusing GDB universal dot operators.
Jan