def _RLPlist(expr, args, kwargs, context):
# Second argument must be a list of types
if not isinstance(args[1], ast.List):
raise TypeMismatchException("Expecting list of types for second argument", args[1])
if len(args[1].elts) == 0:
raise TypeMismatchException("RLP list must have at least one item", expr)
if len(args[1].elts) > 32:
raise TypeMismatchException("RLP list must have at most 32 items", expr)
# Get the output format
_format = []
for arg in args[1].elts:
if isinstance(arg, ast.Name) and arg.id == "bytes":
subtyp = ByteArrayType(args[0].typ.maxlen)
else:
subtyp = parse_type(arg, 'memory')
if not isinstance(subtyp, BaseType):
raise TypeMismatchException("RLP lists only accept BaseTypes and byte arrays", arg)
if not is_base_type(subtyp, ('num', 'num256', 'bytes32', 'address', 'bool')):
raise TypeMismatchException("Unsupported base type: %s" % subtyp.typ, arg)
_format.append(subtyp)
output_type = TupleType(_format)
output_placeholder_type = ByteArrayType((2 * len(_format) + 1 + get_size_of_type(output_type)) * 32)
output_placeholder = context.new_placeholder(output_placeholder_type)
output_node = LLLnode.from_list(output_placeholder, typ=output_placeholder_type, location='memory')
# Create a decoder for each element in the tuple
decoder = []
for i, typ in enumerate(_format):
# Decoder for bytes32
if is_base_type(typ, 'bytes32'):
decoder.append(LLLnode.from_list(
['seq',
['assert', ['eq', ['mload', ['add', output_node, ['mload', ['add', output_node, 32 * i]]]], 32]],
['mload', ['add', 32, ['add', output_node, ['mload', ['add', output_node, 32 * i]]]]]],
typ, annotation='getting and checking bytes32 item'))
# Decoder for address
elif is_base_type(typ, 'address'):
decoder.append(LLLnode.from_list(
['seq',
['assert', ['eq', ['mload', ['add', output_node, ['mload', ['add', output_node, 32 * i]]]], 20]],
['mod',
['mload', ['add', 20, ['add', output_node, ['mload', ['add', output_node, 32 * i]]]]],
['mload', MemoryPositions.ADDRSIZE]]],
typ, annotation='getting and checking address item'))
# Decoder for bytes
elif isinstance(typ, ByteArrayType):
decoder.append(LLLnode.from_list(
['add', output_node, ['mload', ['add', output_node, 32 * i]]],
typ, location='memory', annotation='getting byte array'))
# Decoder for num and num256
elif is_base_type(typ, ('num', 'num256')):
bytez = LLLnode.from_list(
['add', output_node, ['mload', ['add', output_node, 32 * i]]],
typ, location='memory', annotation='getting and checking %s' % typ.typ)
decoder.append(byte_array_to_num(bytez, expr, typ.typ))
# Decoder for bools
elif is_base_type(typ, ('bool')):
# This is basically a really clever way to test for a length-prefixed one or zero. We take the 32 bytes
# starting one byte *after* the start of the length declaration; this includes the last 31 bytes of the
# length and the first byte of the value. 0 corresponds to length 0, first byte 0, and 257 corresponds
# to length 1, first byte \x01
decoder.append(LLLnode.from_list(
['with', '_ans', ['mload', ['add', 1, ['add', output_node, ['mload', ['add', output_node, 32 * i]]]]],
['seq', ['assert', ['or', ['eq', '_ans', 0], ['eq', '_ans', 257]]], ['div', '_ans', 257]]],
typ, annotation='getting and checking bool'))
else:
raise Exception("Type not yet supported")
# Copy the input data to memory
if args[0].location == "memory":
variable_pointer = args[0]
elif args[0].location == "storage":
placeholder = context.new_placeholder(args[0].typ)
placeholder_node = LLLnode.from_list(placeholder, typ=args[0].typ, location='memory')
copier = make_byte_array_copier(placeholder_node, LLLnode.from_list('_ptr', typ=args[0].typ, location=args[0].location))
variable_pointer = ['with', '_ptr', args[0], ['seq', copier, placeholder_node]]
else:
raise Exception("Location not yet supported")
# Decode the input data
initial_setter = LLLnode.from_list(
['seq',
['with', '_sub', variable_pointer,
['pop', ['call',
1500 + 400 * len(_format) + 10 * len(args),
LLLnode.from_list(RLP_DECODER_ADDRESS, annotation='RLP decoder'),
0,
['add', '_sub', 32],
['mload', '_sub'],
output_node,
64 * len(_format) + 32 + 32 * get_size_of_type(output_type)]]],
['assert', ['eq', ['mload', output_node], 32 * len(_format) + 32]]],
typ=None)
# Shove the input data decoder in front of the first variable decoder
decoder[0] = LLLnode.from_list(['seq', initial_setter, decoder[0]], typ=decoder[0].typ, location=decoder[0].location)
return LLLnode.from_list(["multi"] + decoder, typ=output_type, location='memory', pos=getpos(expr))
def bytes_to_num(expr, args, kwargs, context):
return byte_array_to_num(args[0], expr, 'num')