def _build_flow_warp(state, addr, instruction):
warp = nodes.UnconditionalWarp()
warp.type = nodes.UnconditionalWarp.T_FLOW
warp.target = state._warp_in_block(addr + 1)
opcode = instruction.opcode
shift = 1 if opcode in (ins.FORI.opcode, ins.UCLO.opcode) else 0
return warp, shift
def _build_conditional_warp(state, last_addr, instructions):
condition = instructions[-2]
condition_addr = last_addr - 1
warp = nodes.ConditionalWarp()
if condition.opcode in (ins.ISTC.opcode, ins.ISFC.opcode):
expression = _build_unary_expression(state, condition_addr, condition)
setattr(warp, "_slot", condition.A)
elif condition.opcode >= ins.IST.opcode:
expression = _build_unary_expression(state, condition_addr, condition)
setattr(warp, "_slot", condition.CD)
else:
expression = _build_comparison_expression(state, condition_addr,
condition)
warp.condition = expression
jump = instructions[-1]
jump_addr = last_addr
destination = get_jump_destination(jump_addr, jump)
# A condition is inverted during the preparation phase above
warp.false_target = state._warp_in_block(destination)
warp.true_target = state._warp_in_block(jump_addr + 1)
shift = 2
if destination == (jump_addr + 1) \
and condition.opcode not in (ins.ISTC.opcode, ins.ISFC.opcode):
# This is an empty 'then' or 'else'. The simplest way to handle it is
# to insert a Block containing just a no-op statement.
block = nodes.Block()
block.first_address = jump_addr + 1
block.last_address = block.first_address
block.index = warp.true_target.index
block.warpins_count = 1
setattr(block, "_last_body_addr", block.last_address - shift)
block.warp = nodes.UnconditionalWarp()
block.warp.type = nodes.UnconditionalWarp.T_FLOW
block.warp.target = warp.true_target
setattr(block.warp, "_addr", block.last_address - shift + 1)
state.blocks.insert(state.blocks.index(warp.true_target), block)
warp.true_target = block
_create_no_op(state, jump_addr, block)
return warp, shift
def _build_unconditional_warp(state, addr, instruction):
warp = nodes.UnconditionalWarp()
warp.type = nodes.UnconditionalWarp.T_JUMP
opcode = instruction.opcode
warp.is_uclo = opcode == ins.UCLO.opcode
if warp.is_uclo and instruction.CD == 0:
# Not a jump
return _build_flow_warp(state, addr, instruction)
else:
destination = get_jump_destination(addr, instruction)
warp.target = state._warp_in_block(destination)
return warp, 1
def _unwarp_loops(blocks, repeat_until): loops = _find_all_loops(blocks, repeat_until) if len(loops) == 0: return blocks fixed = _cleanup_breaks_and_if_ends(loops, blocks) for start, end in fixed: start_index = blocks.index(start) end_index = blocks.index(end) if repeat_until: body = blocks[start_index:end_index] else: body = blocks[start_index + 1:end_index] loop = _unwarp_loop(start, end, body) body = loop.statements.contents block = nodes.Block() block.first_address = body[0].first_address block.last_address = body[-1].last_address block.index = start.index + 1 block.contents.append(loop) block.warp = nodes.UnconditionalWarp() block.warp.type = nodes.UnconditionalWarp.T_FLOW block.warp.target = end _replace_targets(blocks, body[0], block) _set_end(body[-1]) _unwarp_breaks(start, body, end) blocks = blocks[:start_index + 1] + [block] + blocks[end_index:] return blocks
def _set_flow_to(block, target): block.warp = nodes.UnconditionalWarp() block.warp.type = nodes.UnconditionalWarp.T_FLOW block.warp.target = target
