[patch] Add split DWARF (Fission) support to readelf/objdump

[Cary Coutant <ccoutant at google dot com>]

This patch adds support to readelf and objdump for the split debug
(Fission) extensions to DWARF:

   http://gcc.gnu.org/wiki/DebugFission

In summary, we've added the ability to dump all the .dwo debug
sections (most of which have the same format as the corresponding
regular debug sections), and the new DW_FORM, DW_OP, and DW_AT codes
that we've added. The --dwarf-check option is a new option to enable
some of the DWARF consistency checks that don't always work when not
all sections are present in the same file.

Tested on x86_64, with a compiler that generates split dwarf files.
(The GCC patches are about ready for submission.)

OK to commit?

-cary



2012-05-04  Sterling Augustine  <saugustine@google.com>
	    Cary Coutant  <ccoutant@google.com>

binutils/

	* doc/binutils.texi: Add --dwarf-check option.
	* dwarf.c (dwarf_check): New global flag.
	(fetch_indexed_string): New function.
	(fetch_indexed_value): New function.
	(get_FORM_name): Add DW_FORM_GNU_str_index and DW_FORM_GNU_addr_index.
	(decode_location_expression): Add DW_OP_GNU_addr_index.
	(read_and_display_attr_value): Add DW_FORM_GNU_str_index,
	DW_FORM_GNU_addr_index, DW_AT_GNU_addr_base, and DW_AT_GNU_ranges_base.
	(get_AT_name): Add new attributes for Fission.
	(process_debug_info): Load new debug sections for Fission.
	(load_debug_info): Check for .debug_info.dwo section.
	(display_loc_list, display_loc_list_dwo): New functions.
	(display_debug_loc): Move logic to above two functions.
	(display_debug_info): Choose abbrev section based on info section.
	(display_debug_types): Likewise.
	(display_trace_info): Likewise.
	(comp_addr_base): New function.
	(display_debug_addr): New function.
	(display_debug_str_offsets): New function.
	(display_debug_ranges): Allow missing range lists.  Suppress
	diagnostics if dwarf_check not set.
	(debug_displays): Add column to select abbrev section.
	* dwarf.h (enum dwarf_section_display_enum): Add new debug sections
	for Fission.
	(struct dwarf_section): Add abbrev_sec field.
	(struct dwarf_section_display): New type.
	(debug_info): Add addr_base, ranges_base fields.
	(dwarf_check): New global variable.
	* objdump.c (usage): Add --dwarf-check option.
	(enum option_values): Add OPTION_DWARF_CHECK.
	(long_options): Add --dwarf-check.
	(main): Likewise.
	* readelf.c (OPTION_DWARF_CHECK): New macro.
	(options): Add --dwarf-check.
	(parse_args): Likewise.
	(process_section_headers): Use const_strneq instead of
	streq.

Attachment: binutils-fission-patch-1.txt
Description: Text document