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mirror of synced 2024-11-27 23:50:47 +01:00

Implment several more opcodes in actual decompilation step.

This commit is contained in:
Jennifer Taylor 2021-04-26 01:22:39 +00:00
parent 6052deed3c
commit 6323ef9adf

View File

@ -7,10 +7,12 @@ from .types import (
IfAction,
PushAction,
AddNumVariableAction,
AddNumRegisterAction,
Expression,
Register,
GenericObject,
StringConstant,
InitRegisterAction,
StoreRegisterAction,
DefineFunction2Action,
GotoFrame2Action,
@ -194,6 +196,21 @@ class NullReturnStatement(Statement):
return [f"{prefix}return;"]
class ReturnStatement(Statement):
# A statement which directs the control flow to the end of the code,
# returning the top of the stack.
def __init__(self, ret: Any) -> None:
self.ret = ret
def __repr__(self) -> str:
ret = value_ref(self.ret, "")
return f"return {ret}"
def render(self, prefix: str) -> List[str]:
ret = value_ref(self.ret, prefix)
return [f"{prefix}return {ret};"]
class NopStatement(Statement):
# A literal no-op. We will get rid of these in an optimizing pass.
def __repr__(self) -> str:
@ -234,6 +251,24 @@ class PlayMovieStatement(Statement):
return [f"{prefix}builtin_StartPlaying();"]
class NextFrameStatement(Statement):
# Advance to the next frame, this is an actionscript-specific opcode.
def __repr__(self) -> str:
return "builtin_GotoNextFrame()"
def render(self, prefix: str) -> List[str]:
return [f"{prefix}builtin_GotoNextFrame();"]
class PreviousFrameStatement(Statement):
# Advance to the previous frame, this is an actionscript-specific opcode.
def __repr__(self) -> str:
return "builtin_GotoPreviousFrame()"
def render(self, prefix: str) -> List[str]:
return [f"{prefix}builtin_GotoPreviousFrame();"]
class DebugTraceStatement(Statement):
# Print a debug trace if supported.
def __init__(self, trace: Any) -> None:
@ -303,6 +338,19 @@ class ArithmeticExpression(Expression):
return f"{left} {self.op} {right}"
class NotExpression(Expression):
def __init__(self, obj: Any) -> None:
self.obj = obj
def __repr__(self) -> str:
obj = value_ref(self.obj, "", parens=True)
return f"not {obj}"
def render(self, parent_prefix: str, nested: bool = False) -> str:
obj = value_ref(self.obj, parent_prefix, parens=True)
return f"not {obj}"
class Array(Expression):
# Call a method on an object.
def __init__(self, params: List[Any]) -> None:
@ -446,6 +494,35 @@ class DeleteVariableStatement(Statement):
return [f"{prefix}del {name};"]
class DeleteMemberStatement(Statement):
# Call a method on an object.
def __init__(self, objectref: Any, name: Union[str, int, Expression]) -> None:
self.objectref = objectref
self.name = name
def __repr__(self) -> str:
try:
ref = object_ref(self.objectref, "")
name = name_ref(self.name, "")
return f"del {ref}.{name}"
except Exception:
# This is not a simple string object reference.
ref = object_ref(self.objectref, "")
name = value_ref(self.name, "")
return f"del {ref}[{name}]"
def render(self, prefix: str) -> List[str]:
try:
ref = object_ref(self.objectref, prefix)
name = name_ref(self.name, prefix)
return [f"{prefix}del {ref}.{name};"]
except Exception:
# This is not a simple string object reference.
ref = object_ref(self.objectref, prefix)
name = value_ref(self.name, prefix)
return [f"{prefix}del {ref}[{name}];"]
class StoreRegisterStatement(Statement):
# Set a variable to a value.
def __init__(self, register: Register, valueref: Any) -> None:
@ -1786,6 +1863,16 @@ class ByteCodeDecompiler(VerboseOutput):
chunk.actions[i] = MultiAction(store_actions)
continue
if isinstance(action, InitRegisterAction):
# Same as the above statement, but we are initializing to UNDEFINED.
init_actions: List[StoreRegisterStatement] = []
for reg in action.registers:
init_actions.append(StoreRegisterStatement(reg, UNDEFINED))
chunk.actions[i] = MultiAction(init_actions)
continue
if isinstance(action, JumpAction):
# This could possibly be a jump to the very next line, but we will wait for the
# optimization pass to figure that out.
@ -1811,6 +1898,17 @@ class ByteCodeDecompiler(VerboseOutput):
)
continue
if isinstance(action, AddNumRegisterAction):
chunk.actions[i] = StoreRegisterStatement(
action.register,
ArithmeticExpression(
action.register,
"+" if action.amount_to_add >= 0 else '-',
abs(action.amount_to_add),
)
)
continue
if isinstance(action, AP2Action):
if action.opcode == AP2Action.STOP:
chunk.actions[i] = StopMovieStatement()
@ -1824,6 +1922,14 @@ class ByteCodeDecompiler(VerboseOutput):
chunk.actions[i] = NullReturnStatement()
continue
if action.opcode == AP2Action.NEXT_FRAME:
chunk.actions[i] = NextFrameStatement()
continue
if action.opcode == AP2Action.PREVIOUS_FRAME:
chunk.actions[i] = PreviousFrameStatement()
continue
if action.opcode == AP2Action.CLONE_SPRITE:
depth = stack.pop()
if not isinstance(depth, (int, Expression)):
@ -1847,6 +1953,15 @@ class ByteCodeDecompiler(VerboseOutput):
chunk.actions[i] = NopStatement()
continue
if action.opcode == AP2Action.DELETE:
member_name = stack.pop()
if not isinstance(member_name, (str, int, Expression)):
raise Exception("Logic error!")
obj_name = stack.pop()
chunk.actions[i] = DeleteMemberStatement(obj_name, member_name)
continue
if action.opcode == AP2Action.DELETE2:
variable_name = stack.pop()
if not isinstance(variable_name, (str, StringConstant)):
@ -1883,6 +1998,28 @@ class ByteCodeDecompiler(VerboseOutput):
chunk.actions[i] = NopStatement()
continue
if action.opcode == AP2Action.NOT:
obj_ref = stack.pop()
stack.append(NotExpression(obj_ref))
chunk.actions[i] = NopStatement()
continue
if action.opcode == AP2Action.INSTANCEOF:
name_ref = stack.pop()
obj_to_check = stack.pop()
stack.append(FunctionCall('isinstance', [obj_to_check, name_ref]))
chunk.actions[i] = NopStatement()
continue
if action.opcode == AP2Action.TYPEOF:
obj_to_check = stack.pop()
stack.append(FunctionCall('typeof', [obj_to_check]))
chunk.actions[i] = NopStatement()
continue
if action.opcode == AP2Action.CALL_METHOD:
method_name = stack.pop()
if not isinstance(method_name, (str, int, Expression)):
@ -1914,6 +2051,11 @@ class ByteCodeDecompiler(VerboseOutput):
chunk.actions[i] = NopStatement()
continue
if action.opcode == AP2Action.RETURN:
retval = stack.pop()
chunk.actions[i] = ReturnStatement(retval)
continue
if action.opcode == AP2Action.POP:
# This is a discard. Let's see if its discarding a function or method
# call. If so, that means the return doesn't matter.