examples/examine_dwarf_info.py

   1 #-------------------------------------------------------------------------------
   2 # elftools example: examine_dwarf_info.py
   3 #
   4 # An example of examining information in the .debug_info section of an ELF file.
   5 #
   6 # Eli Bendersky (eliben@gmail.com)
   7 # This code is in the public domain
   8 #-------------------------------------------------------------------------------
   9 from __future__ import print_function
  10 import sys
  11 from elftools.elf.elffile import ELFFile
  12
  13
  14 def process_file(filename):
  15     print('Processing file:', filename)
  16     with open(filename) as f:
  17         elffile = ELFFile(f)
  18
  19         if not elffile.has_dwarf_info():
  20             print('  file has no DWARF info')
  21             return
  22
  23         # get_dwarf_info returns a DWARFInfo context object, which is the
  24         # starting point for all DWARF-based processing in pyelftools.
  25         dwarfinfo = elffile.get_dwarf_info()
  26
  27         for CU in dwarfinfo.iter_CUs():
  28             # DWARFInfo allows to iterate over the compile units contained in
  29             # the .debug_info section. CU is a CompileUnit object, with some
  30             # computed attributes (such as its offset in the section) and
  31             # a header which conforms to the DWARF standard. The access to
  32             # header elements is, as usual, via item-lookup.
  33             print('  Found a compile unit at offset %s, length %s' % (
  34                 CU.cu_offset, CU['unit_length']))
  35
  36             # The first DIE in each compile unit describes it.
  37             top_DIE = CU.get_top_DIE()
  38             print('    Top DIE with tag=%s' % top_DIE.tag)
  39
  40             # Each DIE holds an OrderedDict of attributes, mapping names to
  41             # values. Values are represented by AttributeValue objects in
  42             # elftools/dwarf/die.py
  43             # We're interested in the DW_AT_name attribute. Note that its value
  44             # is usually a string taken from the .debug_string section. This
  45             # is done transparently by the library, and such a value will be
  46             # simply given as a string.
  47             name_attr = top_DIE.attributes['DW_AT_name']
  48             print('    name=%s' % name_attr.value)
  49
  50 if __name__ == '__main__':
  51     for filename in sys.argv[1:]:
  52         process_file(filename)
  53
  54
  55
  56
  57