This is the mail archive of the
mailing list for the GDB project.
Re: dwarf2_get_pc_bounds problem
Your patch fixes the problems I was seeing.
On Fri, 2003-02-14 at 07:12, Daniel Jacobowitz wrote:
> On Fri, Feb 14, 2003 at 02:59:40AM -0800, Martin M. Hunt wrote:
> > I'm investigating several errors in recent versions of gdb and they all
> > seem to be caused by bogus values for lowpc and highpc returned from
> > dwarf2_get_pc_bounds(). I'm not a DWARF expert so maybe the problem is
> > bad debug info, but the code in dwarf2_get_pc_bounds seems suspicious.
> > What I'm seeing is that with a program linked at 0x80000000, all the
> > highpc and lowpc look fine, except those derived from DW_AT_ranges
> > information. Those are all very small, like 0x100. Looking at the code
> > in dwarf2_get_pc_bounds(), most of it seems to be trying to calculate a
> > variable "base" which is then never used. Perhaps a simple addition was
> > left out?
> Ah, er, um, er.... I tested this, how the heck did it work? Aha, my
> test case involved multiple sections, so GCC used a base of 0. That's
> Could you try this obvious fix? Still doesn't fix Jakub's test (we
> really do need discontiguous ranges for that to work) but r_type
> searches one local block instead of going straight to the function.
> Oddly, I remember this happening before. I may have lost the addition
> in a merge somewhere.
> Daniel Jacobowitz
> MontaVista Software Debian GNU/Linux Developer
> 2003-02-14 Daniel Jacobowitz <email@example.com>
> * dwarf2read.c (dwarf2_get_pc_bounds): Offset addresses by base.
> Index: dwarf2read.c
> RCS file: /cvs/src/src/gdb/dwarf2read.c,v
> retrieving revision 1.85
> diff -u -p -r1.85 dwarf2read.c
> --- dwarf2read.c 4 Feb 2003 20:17:02 -0000 1.85
> +++ dwarf2read.c 14 Feb 2003 15:10:24 -0000
> @@ -2195,6 +2195,9 @@ dwarf2_get_pc_bounds (struct die_info *d
> return 0;
> + range_beginning += base;
> + range_end += base;
> /* FIXME: This is recording everything as a low-high
> segment of consecutive addresses. We should have a
> data structure for discontiguous block ranges