Re: [RFC/RFA/i386] pb reading insns if breakpoints still inserted

Joel Brobecker
2006-04-28T21:54:55Z

> So you guys would like to push the deprecation boundary further the
> other way, and deprecate SKIP_PROLOGUE itself? That's an idea.

I agree with idea, but in my humble opinion, it's premature. We're
still stuck with many platforms that are still in the dark ages and
don't provide the necessary frame info in the debugging info for us
to be able to correctly locate function arguments, unwind the call
stack, etc.

> I think the argument was that, in the long run, GCC should be emitting
> location lists so that the debugging information accurately describes
> the location of the arguments even within the prologues. Setting a
> breakpoint on a function would actually set the breakpoint ... at the
> function's entry point. We could delete SKIP_PROLOGUE altogether.
> Then, there'd be no point in producing or consuming an "end of
> prologue" marker whose meaning is kind of vague anyway.

I agree, especially at higher levels of optimization, the notion
of prologue becomes fuzzier and fuzzier. But not all architectures
offer this level of information, and sometimes the system libraries
offer nothing at all but the symbol table.

--
Joel