Re: gdb can't handle a DIE with both sibling and children

Daniel Jacobowitz
2003-07-31T20:29:51Z

On Thu, Jul 31, 2003 at 01:22:29PM -0700, H. J. Lu wrote:
> On Thu, Jul 31, 2003 at 04:02:15PM -0400, Daniel Jacobowitz wrote:
> > >
> > > I don't know for sure how DW_TAG_entry_point works. It seems to me
> > > that DW_TAG_entry_point should inherit DW_AT_accessibility and
> > > DW_AT_high_pc from its parent.
> >
> > Certainly not high_pc. Its _bounds_ are the bounds of its parent; the
> > entry point is only specific PC that gets jumped to.
>
> The entry point is DW_AT_low_pc. From what I can see, its DW_AT_high_pc
> should be the same as its parent. See
>
> http://www-sld.slac.stanford.edu/HELP/FORTRAN/STATEMENTS/ENTRY

Think about this for a moment.

DW_AT_low_pc represents a PC - an entry point.

DW_AT_low_pc + DW_AT_high_pc represents a range - a whole subroutine.

The bounds of the entry point are the bounds of the entire function, or
none at all. Inheriting DW_AT_high_pc makes no sense. In Fortran,
they represent a low_pc->high_pc range, but there are a number of other
useful meanings for it.

Besides, what would you do if a function had DW_AT_ranges?

--
Daniel Jacobowitz
MontaVista Software Debian GNU/Linux Developer