defs

#!/usr/bin/env python
from __future__ import print_function
import os
import subprocess

import sys
if sys.version_info[0] == 2:
    subp_ascii = {}
else:
    subp_ascii = dict(encoding='ascii')

def main():
    import argparse
    ap = argparse.ArgumentParser()
    ap.add_argument('-d','--with-data', action='store_true',
                    help='Show data symbols in addition to functions')
    ap.add_argument('binfile',
                    help='Executable or object file')
    args = ap.parse_args()
    un = os.path.basename(ap.prog).startswith('un')
    #
    binfile = args.binfile
    try:
        if not os.path.isfile(binfile):
            if os.path.sep not in binfile:
                full = ffip(binfile)
                if full is None:
                    raise ValueError('%s not found in PATH' % binfile)
                binfile = full
            else:
                raise ValueError('%s: No such file or directory' % binfile)
        with open(binfile, 'rb') as f:
            magic = f.read(32)
        if magic[:4] == b'\x7FELF':
            symdefs = elf_defs(un, binfile,
                               with_data=args.with_data)
        elif magic[2:4] == b'\x01\x07':
            # big-endian executable
            if magic[1:2] in (b'\x01', b'\x02'):
                # mc68010 or mc68020
                symdefs = m68k_defs(un, binfile,
                                    with_data=args.with_data)
        else:
            raise ValueError('%s: Unknown file type' % binfile)
        for sym in sorted(set(symdefs)):
            print(sym)
    except Exception as e:
        raise
        import sys
        print('%s: %s' % (ap.prog, e))
        sys.exit(1)

def elf_defs(un, binfile, with_data=False):
    for line in iter_output(['readelf','--symbols','--wide',binfile]):
        fields = line.split(None, 7)
        if len(fields) < 8:
            continue
        if fields[0].endswith(':') and fields[0][:-1].isdigit():
            #print(fields)
            _, _, _, type, bind, _, ndx, syminfo = fields[:8]
            sym, _, scope = syminfo.partition('@')
            if un:
                if ndx == 'UND':
                    yield sym
            else:
                if ndx != 'UND':
                    if with_data or type == 'FUNC':
                        yield sym

def m68k_defs(un, binfile, with_data=False):
    return _nm_defs('nm68k', un, binfile, with_data=with_data)

def _nm_defs(nm, un, binfile, with_data=False):
    """Extract symbols using 'nm' or a variant thereof"""
    if not ffip(nm):
        raise RuntimeError('No %s found in PATH' % nm)
    if un:
        tmatch = set('U')
    else:
        tmatch = set('T')
        if with_data:
            tmatch.add('D')
    for line in iter_output([nm,'-p',binfile]):
        xaddr, t, sym = ('x'+line).split(None, 2)
        if t in tmatch:
            yield sym

def iter_output(cmd):
    p = subprocess.Popen(cmd, stdout=subprocess.PIPE, **subp_ascii)
    for line in p.stdout:
        yield line.rstrip('\n')
    p.wait()

def ffip(name):
    """Find named file in PATH"""
    for dir in os.environ.get('PATH','/bin:/usr/bin').split(os.pathsep):
        fullname = os.path.join(dir, name)
        if os.path.isfile(fullname):
            return fullname
    return None

main()