import struct

# Calculate checksum of function
def calc_func_crc(func_begin, func_end):
    crc = 0
    for i in range(func_begin, func_end):
        crc += struct.unpack("B", i)[0]
    return crc

# Debuggee function
def debuggee_function():
    calc = 0
    calc += 2
    calc <<= 8
    calc -= 3

# End of debuggee function
def debuggee_function_end():
    pass

# Original function checksum
ORIG_CRC = 0x2bd0

# Calculate current function checksum
CUR_CRC = calc_func_crc(debuggee_function, debuggee_function_end)

# Check if current checksum matches original checksum
if CUR_CRC != ORIG_CRC:
    print("Stop debugging program!")
    exit(-1)