Re: Patch: DWARF2 location lists vs. shared libraries

Daniel Jacobowitz
2004-05-05T04:03:48Z

On Tue, May 04, 2004 at 08:45:52PM -0400, Bryce McKinlay wrote:
> 2004-05-04 Bryce McKinlay <mckinlay@redhat.com>
>
> * dwarf2read.c (dwarf2_symbol_mark_computed): Use ANOFFSET to
> adjust baton's base_address for shared libraries.

I spoke briefly to Bryce about this (on IRC).

I think the right thing to do would be to add the offset when
searching, rather than when saving. This will help us with relocating
objfiles, which I think would be good to support - that way we can
cache debug info for unchanged shared libraries across runs.

Does this make sense to others? I'll try to write the patch tomorrow
or Thursday.

>
> Index: dwarf2read.c
> ===================================================================
> RCS file: /cvs/src/src/gdb/dwarf2read.c,v
> retrieving revision 1.150
> diff -u -r1.150 dwarf2read.c
> --- dwarf2read.c 4 May 2004 00:11:25 -0000 1.150
> +++ dwarf2read.c 5 May 2004 00:41:00 -0000
> @@ -8662,6 +8662,7 @@
> if (attr->form == DW_FORM_data4 || attr->form == DW_FORM_data8)
> {
> struct dwarf2_loclist_baton *baton;
> + CORE_ADDR base_offset;
>
> baton = obstack_alloc (&cu->objfile->objfile_obstack,
> sizeof (struct dwarf2_loclist_baton));
> @@ -8671,7 +8672,10 @@
> don't run off the edge of the section. */
> baton->size = dwarf2_per_objfile->loc_size - DW_UNSND (attr);
> baton->data = dwarf2_per_objfile->loc_buffer + DW_UNSND (attr);
> - baton->base_address = cu->header.base_address;
> + /* Set base_address, adjusting for shared libraries. */
> + base_offset = ANOFFSET (cu->objfile->section_offsets,
> + SECT_OFF_TEXT (cu->objfile));
> + baton->base_address = cu->header.base_address + base_offset;
> if (cu->header.base_known == 0)
> complaint (&symfile_complaints,
> "Location list used without specifying the CU base address.");

--
Daniel Jacobowitz