Re: [RFC/RFA?] Should break FILE:LINENO skip prologue?

Joel Brobecker
2008-01-09T19:44:49Z

> I don't remember the original conversation, but the suggestion still
> sounds like a good idea to me. (Whew!)

Cool! (double whew ;-)

> > [1]: I think we have made some progress with parameter/variable
> > tracking with DWARF, but I think it's not activated by default
> > and we also still support platforms where DWARF is not available.
>
> What is "not activated by default", exactly? Is it in GCC? In GDB?
> Where in GDB?

I think it's in GCC. I am not a GCC expert, so I might be wrong,
but I think that the option is -fvar-tracking. Eric Botcazou told
me about this option when debugging at -O1 or -O2, but apparently,
it has some drawbacks (for now, at least). IIUC, it had to do with
the fact that the optimizers have do so much work that it's hard
to relate back to the original source code entity.

> I've long had this dream that eventually we would just stop skipping
> prologues altogether, because everything would actually work at every
> instruction in the function.

Me too, but I think we're still quite a long ways away from this
happening. There is also the case of stabs, that is still, despite
a lot of effort from many people (including AdaCore), not extinct.

--
Joel