From 509fc35fcbf1aa0847428fbfb4310ca712f684a0 Mon Sep 17 00:00:00 2001 From: Joran Honig Date: Mon, 10 Dec 2018 16:55:21 +0100 Subject: [PATCH] Implements array type --- mythril/laser/smt/array.py | 43 +++++++++++++++++++++++++++++++++++++ mythril/laser/smt/solver.py | 0 2 files changed, 43 insertions(+) create mode 100644 mythril/laser/smt/array.py create mode 100644 mythril/laser/smt/solver.py diff --git a/mythril/laser/smt/array.py b/mythril/laser/smt/array.py new file mode 100644 index 00000000..b906b6e5 --- /dev/null +++ b/mythril/laser/smt/array.py @@ -0,0 +1,43 @@ +from mythril.laser.smt.bitvec import BitVec +import z3 + + +class BaseArray: + """ + Base array type, implements basic store and set operations + """ + def __getitem__(self, item: BitVec): + """ Gets item from the array, item can be symbolic""" + if isinstance(item, slice): + raise ValueError("Instance of BaseArray, does not support getitem with slices") + return z3.Select(self.raw, item.raw) + + def __setitem__(self, key: BitVec, value: BitVec): + """ Sets an item in the array, key can be symbolic""" + self.raw = z3.Store(self.raw, key, value) + + +class Array(BaseArray): + def __init__(self, name: str, domain: int, value_range: int): + """ + Initializes a symbolic array + :param name: Name of the array + :param domain: The domain for the array (10 -> all the values that a bv of size 10 could take) + :param range: The range for the values in the array (10 -> all the values that a bv of size 10 could take) + """ + self.domain = z3.BitVecSort(domain) + self.range = z3.BitVecSort(value_range) + self.raw = z3.Array(name, self.domain, self.range) + + +class K(BaseArray): + def __init__(self, domain: int, value_range: int, value: int): + """ + Initializes an array with a default value + :param domain: The domain for the array (10 -> all the values that a bv of size 10 could take) + :param value_range: The range for the values in the array (10 -> all the values that a bv of size 10 could take) + :param value: The default value to use for this array + """ + self.domain = z3.BitVecSort(domain) + self.value = z3.BitVecVal(value, value_range) + self.raw = z3.K(self.domain, self.value) diff --git a/mythril/laser/smt/solver.py b/mythril/laser/smt/solver.py new file mode 100644 index 00000000..e69de29b