expr_inferrer.py 文件源码

def _infer_arithmetic(left_type, right_type, op, lineno, solver):
    """Infer the type of an arithmetic operation, and add the corresponding axioms"""
    result_type = solver.new_z3_const("arithmetic_result")

    magic_method = ""
    if isinstance(op, ast.Sub):
        magic_method = "__sub__"
    elif isinstance(op, ast.FloorDiv):
        magic_method = "__floordiv__"
    elif isinstance(op, ast.Mod):
        magic_method = "__mod__"
    elif isinstance(op, ast.LShift):
        magic_method = "__lshift__"
    elif isinstance(op, ast.RShift):
        magic_method = "__rshift__"

    solver.add(axioms.arithmetic(left_type, right_type, result_type, magic_method,
                                 isinstance(op, ast.Mod), solver.z3_types),
               fail_message="Arithmetic operation in line {}".format(lineno))
    return result_type