# Copyright 2024 Apheleia
#
# Description:
# Apheleia Verification Library Variable Class
from __future__ import annotations
from collections.abc import Callable
from typing import Any
from z3 import BitVec
from .var import Var
[docs]
class Logic(Var):
def __copy__(self):
"""
Copy the Logic - always make a copy to ensure randomness is preserved.
:return: Copied Var.
:rtype: Var
"""
new_obj = Logic(self.value, auto_random=self._auto_random_, fmt=self._fmt_, width=self.width)
new_obj._constraints_ = {
k: v.copy() for k, v in self._constraints_.items()
}
return new_obj
[docs]
def __init__(
self,
*args,
auto_random: bool = True,
fmt: Callable[..., int] = hex,
width: int = 32
) -> None:
"""
Initialize an instance of the class.
:param value: The initial value of the variable.
:type value: any
:param auto_random: Indicates if the variable should be automatically randomized, defaults to True.
:type auto_random: bool, optional
:param fmt: The format of the variable, defaults to hex.
:type fmt: type, optional
:param width: The width of the variable in bits, defaults to 32.
:type width: int, optional
:raises ValueError: If the width is not a positive integer.
"""
if not isinstance(width, int) or width <= 0:
raise ValueError("Width must be a positive integer.")
self.width = int(width)
super().__init__(*args, auto_random=auto_random, fmt=fmt)
def _cast_(self, other: Any) -> int:
"""
Cast the value to the appropriate type based on the width of the variable.
:param other: The value to be cast.
:type other: Any
:return: The casted value.
:rtype: int
"""
v = other.value if isinstance(other, Logic) else other
return int(v & self._range_()[1])
def _wrap_(self, result : Any) -> Logic:
"""
Wrap the result in an Logic instance.
:param result: The result to be wrapped.
:type result: Any
:return: An instance of Logic with the result.
:rtype: Logic
"""
return type(self)(result, auto_random=self._auto_random_, fmt=self._fmt_, width=self.width)
def _range_(self) -> tuple[int, int]:
"""
Get the range of values that can be represented by this variable.
:return: A tuple containing the minimum and maximum values.
:rtype: tuple[int, int]
"""
return (0, (1 << self.width) - 1)
def _z3_(self) -> BitVec:
"""
Get the Z3 representation of the variable.
:return: The Z3 BitVec representation of the variable.
:rtype: z3.BitVecRef
"""
return BitVec(f"{self._idx_}", self.width)
__all__ = ["Logic"]