PATCH: Add support for decoding .debug_ranges to readelf

[Nick Clifton]

Hi Guys,

  I am applying the attached patch to add the ability to decode the
  contents of .debug_ranges sections to readelf.  This takes two
  forms.  The decoding is done automatically for a specific range when
  a DW_AT_range attribute is encountered and the entire contents of a
  .debug_ranges section can be displayed via the --debug-dump=Ranges
  command line switch.  (Short form: -wR).

  I have included code that should work with 64bit ranges but I have
  not test this yet.

  In the course of developing this patch I also encountered a couple
  of bugs.  One was that the dump_sects array was not being correctly
  reinitialised for each object file that was dumped.  There was code
  in main() to reinitialise the array for each object file specified
  on the command line, but this did not take into account the
  possibility that an archive was being dumped.  Since archives can
  contain multiple object file it is necessary to reinitialise the
  dump_sects array before dumping every single binary

  Another bug was the debug_apply_rela_addends() function warning
  about relocations against STT_OBJECT type symbols.  These can occur
  in good code (eg the _clz.o binary in libgcc.a), and so should be
  allowed. 

  I have included fixes for both of these bugs.
  
  I also tidied up the parsing of the --debug-dump switch so that it
  uses a table structure rather than a long switch statement.  I also
  added a streq() and strneq() macro to tidy up string comparison
  expressions.

binutils/ChangeLog
2004-11-03  Nick Clifton  <nickc@redhat.com>

	* readelf.c (do_debug_ranges): New variable.
	(usage): Document new switch: -wR or --debug-dump=Ranges.
	(parse_args): Handle new switch.  Replace switch statement for the
	long options with a more compact table structure.
	(process_section_headers): Allow the dumping of .debug_ranges
	sections if so requested.
	(debug_displays): Likewise.
	(load_debug_range): New function: Grabs the contents of a
	.debug_ranges section.
	(free_debug_range): New function: Releases the grabbed
	.debug_ranges section.
	(decode_64bit_range): New function: Displays a 64-bit range in a
	.debug_ranges section.
	(decode_range): New function: Displays a 32-bit range in a
	.debug_ranges section.
	(read_and_display_attr_value): Record the value of DW_AT_low_pc
	attributes.  Use decode_ranges() to display a DW_AT_ranges
	attribute.
	(display_debug_info): Use load_debug_range() and
	free_debug_range().
	(display_64bit_debug_ranges): New function.  Displays the contents
	of a 64-bit format .debug_ranges section.
	(display_debug_ranges): New function: Displays the contents of a
	32-bit .debug_ranges section.
	
	(main): Move cmdline_dump_sects and num_cmdline_dump_sects into the
	global scope.
	(process_object): Initialise the dump_sects array from the
	cmdline_dump_sects array before processing each object file.

	(streq, strneq): New macros.  Use them to replace occurrences of
	strcmp() and strncmp().

	(debug_information): New structure array to replace
	debug_line_pointer_sizes array.
	(num_debug_info_entries): New variable to replace
	num_debug_line_pointers.
	(get_pointer_size_of_comp_unit): New function: Returns the pointer
	size of a given compilation unit.
	(get_debug_info): New function to replace
	get_debug_line_pointer_sizes.
	(display_debug_lines): Use the new functions.
	(display_debug_loc): Likewise.
	
	(disassemble_section): Change return type to int.
	(display_debug_lines): Move local variables to their
	innermost scope.
	(display_debug_section): Likewise.  Also record the return value
	of functions called and pass this back to the parent.  Also only
	warn about undumped sections when the user explicitly requested
	their dumping.

	(debug_apply_rela_addends): Allow relocations against STT_OBJECT
	types as well.
	
	* NEWS: Mention the support for decoding .debug_ranges sections.
	* doc/binutils.texi: Document the new command line switch to
	readelf.

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