[branch patch] dwarf-frame.c support for .eh_frame_hdr

[Mark Kettenis]

   Date: Mon, 12 May 2003 02:46:54 -0700
   From: Roland McGrath <roland@redhat.com>

   2003-05-12  Roland McGrath  <roland@redhat.com>

	   * dwarf2read.c (dwarf_eh_frame_hdr_offset, dwarf_eh_frame_hdr_size,
	   dwarf_eh_frame_hdr_section): New variables.
	   (dwarf2_locate_sections): Match a section whose name starts with
	   "eh_frame_hdr", and set those.
	   (dwarf2_has_info): Clear dwarf_eh_frame_hdr_offset here.
	   * dwarf-frame.c (decode_eh_frame_hdr): New function.
	   (dwarf2_build_frame_info): Call it when dwarf_eh_frame_hdr_offset
	   is set but dwarf_eh_frame_offset is not.

Having to build a "dummy" `struct comp_unit' probably indicates that I
should change read_encoded_value()'s signature.  Well, I'll worry
about that later.

The error messages in dwarf-frame.c should probably be harmonized
before we check merge this into mailine.  I wonder whether we should
complaint() instead of error().

Is there a particular reason why you don't read in the .eh_frame_hdr
section as a whole as the other parts of GDB's "symbol reader" do (and
which I just blindly copied when I wrote the guts of dwarf-frame.c)?

	   * symfile.c (symfile_bfd_open): Try bfd_check_format with bfd_core
	   if bfd_object fails.

I think a more elaborate comment on why core files might have
"symbols" is appropriate.

Mark