image.py

from bytecodes import *
from ceptions import IllegalInstructionError
from opcodes import actions, dup_ops, swap_ops


def union(list_1, list_2):
    if list_1 == list_2:
        return list_1
    if isinstance(list_1, ByteCode):
        list_1 = [list_1]
    if isinstance(list_2, ByteCode):
        list_2 = [list_2]
    return list(set(list_1) | set(list_2))


class Image(object):
    def __init__(self, id_str, other=None):
        self.block_id = id_str
        self.stack = dict()
        self.top = 0
        if not other:
            return
        for k in other.stack:
            self.stack[k] = other.stack[k]
        self.top = other.top

    def debug_stack(self):
        for pos in sorted(self.stack.keys()):
            print("%d\t%s" % (pos, str(self.stack[pos])))
        print("")

    def interpret_bytecode(self, bytecode):
        opcode = bytecode.opcode
        if opcode not in actions:
            raise IllegalInstructionError("GARBAGE bytcode encountered")

        delta = actions[opcode][0]
        alpha = actions[opcode][1]

        reads = [self.top - i - 1 for i in range(delta)]
        writes = [self.top - delta + i for i in range(alpha)]

        if opcode in dup_ops:
            self.stack[self.top] = self.stack[self.top - delta]
            self.top = self.top - delta + alpha
            return

        if opcode in swap_ops:
            read1, read2 = self.top - delta, self.top - 1
            temp = self.stack[read1]
            self.stack[read1] = self.stack[read2]
            self.stack[read2] = temp
            return

        self.top = self.top - delta + alpha

        for i, stack_pos in enumerate(reads):
            bytecode.set_dependency(i, self.stack.pop(stack_pos))

        for stack_pos in writes:
            self.stack[stack_pos] = bytecode

    # make a copy, but not really a deep copy
    def make_copy(self):
        other = Image(self.block_id)
        other.top = self.top
        stack_1, stack_2 = self.stack, other.stack
        for pos, instructions in stack_1.items():
            stack_2[pos] = instructions
        return other

    # combine two different stacks
    def __add__(self, other):
        if self.top != other.top:
            raise RuntimeWarning("[WARNING] stack pointer not matched")

        temp, stack = Image(self.top), dict()
        stack_1, stack_2 = self.stack, other.stack
        for pos, instructions in stack_1.items():
            stack[pos] = instructions

        for pos, instructions in stack_2.items():
            if pos in stack:
                result = union(stack[pos], instructions)
                stack[pos] = result
            else:
                stack[pos] = instructions
        temp.stack = stack
        return temp

    def __eq__(self, other):
        if self.top != other.top:
            return False
        for i in range(self.top):
            # try:
            if isinstance(self.stack[i], PushByteCode) \
                    and self.stack[i] != other.stack[i]:
                return False
            # except KeyError:
            # 	raise DependencyError
        return True