#!/usr/bin/env python3

import imp
import os
import subprocess
import re

import common
rungdb = imp.load_source('rungdb', os.path.join(common.root_dir, 'rungdb'))

parser = common.get_argparse(argparse_args={
    'description': '''GDB step debug guest userland processes without gdbserver.

More information at: https://github.com/cirosantilli/linux-kernel-module-cheat#gdb-step-debug-userland-processes
'''
})
parser.add_argument(
    'executable',
    help='Path to the executable to be debugged relative to the Buildroot build directory.'
)
parser.add_argument(
    'break',
    default=None,
    help='Break at this point, e.g. main.',
    nargs='?'
)
args = common.setup(parser)
readelf_header = subprocess.check_output([
  common.get_toolchain_tool('readelf'),
  '-h',
  os.path.join(common.build_dir, args.executable),
])
for line in readelf_header.decode().split('\n'):
    split = line.split()
    if line.startswith('  Entry point address:'):
        addr = line.split()[-1]
        break
print(addr)
extra_args = {}
extra_args['before'] = '-ex \"add-symbol-file {} {}\"'.format(args.executable, addr)
# Or else lx-symbols throws for arm:
# gdb.MemoryError: Cannot access memory at address 0xbf0040cc
# TODO understand better.
# Also, lx-symbols overrides the add-symbol-file commands.
extra_args['no_lxsymbols'] = True
rungdb.main(args, extra_args)