Re: [PATCH]: Add support for outputting dwarf2 location lists

[Daniel Berlin <dan at cgsoftware dot com>]

Jason Merrill <jason_merrill@redhat.com> writes:

> >>>>> "Daniel" == Daniel Berlin <dan@www.cgsoftware.com> writes:
> 
> > On 19 Apr 2001, Jason Merrill wrote:
> 
> >> Please add the 2.1 support soon; otherwise this is of limited utility for
> >> C++, since we often have functions in other sections.
> 
> > Well, here's the thing.
> > I was going to add it before submitting it, since it's not all that
> > difficult, but i noticed that the low_pc and high_pc attributes are always
> > based on the text section label as well.
> 
> Er, yes.  What else would they be based on?
You say above "We often have functions in other sections".

What are the low_pc and high_pc of those functions based on?


> Note that they are never generated if there are functions in other
> sections, as specified by the standard.
2.1 says all subroutines  either have DW_AT_low_pc and high_pc
attributes, if the range is contiguous, or a DW_AT_ranges attribute, if it's a non-contiguous
range of addresses.
It mentions nothing of sections. I don't remember 2.0 mentioning
anything about sections iether.

I don't have 2.0 handy to compare (though DW_AT_ranges is new, IIRC).

> 
> > Once I saw that, i didn't see much point in doing it right away, since if
> > you had a function in a seperate place, it wouldn't work anyway.
> 
> Why not?
Because we don't generate low_pc and high_pc attributes, or a
DW_AT_ranges attribute.


If GDB doesn't know where the function is, how would it help for it to
know where the variables in the function are?

> 
> Jason

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