Extension types

pyMHF provides a number of extra types which can be used to either extend the built-in python ctypes library, or interface with c++ code more easily.

Note

These types should be considered experimental unless otherwise specified.

ctypes extensions

c_char_p32

This class is a wrapper around the ctypes.c_uint32 type to emulate the ctypes.c_char_p type. This is required because using ctypes.c_char_p as the type of a function argument can cause issues when the hooked function is called.

c_char_p64

This class is a wrapper around the ctypes.c_uint64 type to emulate the ctypes.c_char_p type. This is required because using ctypes.c_char_p as the type of a function argument can cause issues when the hooked function is called.

Both of these above types have the __str__ method defined on them, so the values can be logged directly (see example below). The value property of these classes is still the original integer in case that is needed for passing in to other functions.

import ctypes
import logging
from pymhf import Mod
from pymhf.extensions.ctypes import c_char_p64
from pymhf.core.hooking import static_function_hook

@static_function_hook("48 89 5C 24 ? 48 89 7C 24 ? 48 8B 05")
@staticmethod
def GetLookup(lpacName: c_char_p64) -> ctypes.c_uint64:
    ...

class ExampleMod(Mod):
    @GetLookup.before
    def log_lookup(self, lpacName: c_char_p64):
        logger.info(f"Got the lookup {lpacName}")

c_enum16

This class is a wrapper around the ctypes.c_int32 type, but it’s able to be subscripted to provide a concrete type based on the IntEnum used.

c_enum32

This class is a wrapper around the ctypes.c_int32 type, but it’s able to be subscripted to provide a concrete type based on the IntEnum used.

For example, consider the following code:

from pymhf.utils.partial_struct import partial_struct
from pymhf.extensions.ctypes import c_enum32
import ctypes
from enum import IntEnum
from typing import Annotated

class States(IntEnum):
    OFF = 0
    ON = 1
    UNDEFINED = 2

@partial_struct
class Test(ctypes.Structure):
    a: Annotated[c_enum32[States], 0x0]
    b: Annotated[ctypes.c_uint32, 0x10]

In the above we have cretated an enum which is mapped to a ctypes.c_uint32 variable. We can assign the value of a to an enum member after the struct has been instantiated with data, as well as being able to “see” the value of the int as an enum member instead.