def base_type_conversion(orig, frm, to, pos=None):
orig = unwrap_location(orig)
if not isinstance(frm,
(BaseType, NullType)) or not isinstance(to, BaseType):
raise TypeMismatchException(
"Base type conversion from or to non-base type: %r %r" % (frm, to),
pos)
elif is_base_type(frm, to.typ) and are_units_compatible(frm, to):
return LLLnode(orig.value,
orig.args,
typ=to,
add_gas_estimate=orig.add_gas_estimate)
elif is_base_type(frm, 'num') and is_base_type(
to, 'decimal') and are_units_compatible(frm, to):
return LLLnode.from_list(['mul', orig, DECIMAL_DIVISOR],
typ=BaseType('decimal', to.unit,
to.positional))
elif is_base_type(frm, 'num256') and is_base_type(
to, 'num') and are_units_compatible(frm, to):
return LLLnode.from_list(
['uclample', orig, ['mload', MemoryPositions.MAXNUM]],
typ=BaseType("num"))
elif isinstance(frm, NullType):
if to.typ not in ('num', 'bool', 'num256', 'address', 'bytes32',
'decimal'):
raise TypeMismatchException(
"Cannot convert null-type object to type %r" % to, pos)
return LLLnode.from_list(0, typ=to)
else:
raise TypeMismatchException(
"Typecasting from base type %r to %r unavailable" % (frm, to), pos)
def attribute(self):
# x.balance: balance of address x
if self.expr.attr == 'balance':
addr = Expr.parse_value_expr(self.expr.value, self.context)
if not is_base_type(addr.typ, 'address'):
raise TypeMismatchException("Type mismatch: balance keyword expects an address as input", self.expr)
return LLLnode.from_list(['balance', addr], typ=BaseType('num', {'wei': 1}), location=None, pos=getpos(self.expr))
# x.codesize: codesize of address x
elif self.expr.attr == 'codesize' or self.expr.attr == 'is_contract':
addr = Expr.parse_value_expr(self.expr.value, self.context)
if not is_base_type(addr.typ, 'address'):
raise TypeMismatchException("Type mismatch: codesize keyword expects an address as input", self.expr)
if self.expr.attr == 'codesize':
output_type = 'num'
else:
output_type = 'bool'
return LLLnode.from_list(['extcodesize', addr], typ=BaseType(output_type), location=None, pos=getpos(self.expr))
# self.x: global attribute
elif isinstance(self.expr.value, ast.Name) and self.expr.value.id == "self":
if self.expr.attr not in self.context.globals:
raise VariableDeclarationException("Persistent variable undeclared: " + self.expr.attr, self.expr)
var = self.context.globals[self.expr.attr]
return LLLnode.from_list(var.pos, typ=var.typ, location='storage', pos=getpos(self.expr), annotation='self.' + self.expr.attr)
# Reserved keywords
elif isinstance(self.expr.value, ast.Name) and self.expr.value.id in ("msg", "block", "tx"):
key = self.expr.value.id + "." + self.expr.attr
if key == "msg.sender":
return LLLnode.from_list(['caller'], typ='address', pos=getpos(self.expr))
elif key == "msg.value":
if not self.context.is_payable:
raise NonPayableViolationException("Cannot use msg.value in a non-payable function", self.expr)
return LLLnode.from_list(['callvalue'], typ=BaseType('num', {'wei': 1}), pos=getpos(self.expr))
elif key == "msg.gas":
return LLLnode.from_list(['gas'], typ='num', pos=getpos(self.expr))
elif key == "block.difficulty":
return LLLnode.from_list(['difficulty'], typ='num', pos=getpos(self.expr))
elif key == "block.timestamp":
return LLLnode.from_list(['timestamp'], typ=BaseType('num', {'sec': 1}, True), pos=getpos(self.expr))
elif key == "block.coinbase":
return LLLnode.from_list(['coinbase'], typ='address', pos=getpos(self.expr))
elif key == "block.number":
return LLLnode.from_list(['number'], typ='num', pos=getpos(self.expr))
elif key == "block.prevhash":
return LLLnode.from_list(['blockhash', ['sub', 'number', 1]], typ='bytes32', pos=getpos(self.expr))
elif key == "tx.origin":
return LLLnode.from_list(['origin'], typ='address', pos=getpos(self.expr))
else:
raise Exception("Unsupported keyword: " + key)
# Other variables
else:
sub = Expr.parse_variable_location(self.expr.value, self.context)
if not isinstance(sub.typ, StructType):
raise TypeMismatchException("Type mismatch: member variable access not expected", self.expr.value)
attrs = sorted(sub.typ.members.keys())
if self.expr.attr not in attrs:
raise TypeMismatchException("Member %s not found. Only the following available: %s" % (self.expr.attr, " ".join(attrs)), self.expr)
return add_variable_offset(sub, self.expr.attr)
def make_clamper(datapos, mempos, typ, is_init=False):
if not is_init:
data_decl = ['calldataload', ['add', 4, datapos]]
copier = lambda pos, sz: ['calldatacopy', mempos, ['add', 4, pos], sz]
else:
data_decl = ['codeload', ['add', '~codelen', datapos]]
copier = lambda pos, sz: [
'codecopy', mempos, ['add', '~codelen', pos], sz
]
# Numbers: make sure they're in range
if is_base_type(typ, 'num'):
return LLLnode.from_list([
'clamp', ['mload', MemoryPositions.MINNUM], data_decl,
['mload', MemoryPositions.MAXNUM]
],
typ=typ,
annotation='checking num input')
# Booleans: make sure they're zero or one
elif is_base_type(typ, 'bool'):
return LLLnode.from_list(['uclamplt', data_decl, 2],
typ=typ,
annotation='checking bool input')
# Addresses: make sure they're in range
elif is_base_type(typ, 'address'):
return LLLnode.from_list(
['uclamplt', data_decl, ['mload', MemoryPositions.ADDRSIZE]],
typ=typ,
annotation='checking address input')
# Bytes: make sure they have the right size
elif isinstance(typ, ByteArrayType):
return LLLnode.from_list([
'seq',
copier(data_decl, 32 + typ.maxlen),
[
'assert',
['le', ['calldataload', ['add', 4, data_decl]], typ.maxlen]
]
],
typ=None,
annotation='checking bytearray input')
# Lists: recurse
elif isinstance(typ, ListType):
o = []
for i in range(typ.count):
offset = get_size_of_type(typ.subtype) * 32 * i
o.append(
make_clamper(datapos + offset, mempos + offset, typ.subtype,
is_init))
return LLLnode.from_list(['seq'] + o,
typ=None,
annotation='checking list input')
# Otherwise don't make any checks
else:
return LLLnode.from_list('pass')
def boolean_operations(self):
if len(self.expr.values) != 2:
raise StructureException("Expected two arguments for a bool op", self.expr)
left = Expr.parse_value_expr(self.expr.values[0], self.context)
right = Expr.parse_value_expr(self.expr.values[1], self.context)
if not is_base_type(left.typ, 'bool') or not is_base_type(right.typ, 'bool'):
raise TypeMismatchException("Boolean operations can only be between booleans!", self.expr)
if isinstance(self.expr.op, ast.And):
op = 'and'
elif isinstance(self.expr.op, ast.Or):
op = 'or'
else:
raise Exception("Unsupported bool op: " + self.expr.op)
return LLLnode.from_list([op, left, right], typ='bool', pos=getpos(self.expr))
def parse_return(self):
from .parser import (make_setter)
if self.context.return_type is None:
if self.stmt.value:
raise TypeMismatchException("Not expecting to return a value",
self.stmt)
return LLLnode.from_list(['return', 0, 0],
typ=None,
pos=getpos(self.stmt))
if not self.stmt.value:
raise TypeMismatchException("Expecting to return a value",
self.stmt)
sub = Expr(self.stmt.value, self.context).lll_node
self.context.increment_return_counter()
# Returning a value (most common case)
if isinstance(sub.typ, BaseType):
if not isinstance(self.context.return_type, BaseType):
raise TypeMismatchException(
"Trying to return base type %r, output expecting %r" %
(sub.typ, self.context.return_type), self.stmt.value)
sub = unwrap_location(sub)
if not are_units_compatible(sub.typ, self.context.return_type):
raise TypeMismatchException(
"Return type units mismatch %r %r" %
(sub.typ, self.context.return_type), self.stmt.value)
elif is_base_type(sub.typ, self.context.return_type.typ) or \
(is_base_type(sub.typ, 'num') and is_base_type(self.context.return_type, 'signed256')):
return LLLnode.from_list(
['seq', ['mstore', 0, sub], ['return', 0, 32]],
typ=None,
pos=getpos(self.stmt))
else:
raise TypeMismatchException(
"Unsupported type conversion: %r to %r" %
(sub.typ, self.context.return_type), self.stmt.value)
# Returning a byte array
elif isinstance(sub.typ, ByteArrayType):
if not isinstance(self.context.return_type, ByteArrayType):
raise TypeMismatchException(
"Trying to return base type %r, output expecting %r" %
(sub.typ, self.context.return_type), self.stmt.value)
if sub.typ.maxlen > self.context.return_type.maxlen:
raise TypeMismatchException(
"Cannot cast from greater max-length %d to shorter max-length %d"
% (sub.typ.maxlen, self.context.return_type.maxlen),
self.stmt.value)
# Returning something already in memory
if sub.location == 'memory':
return LLLnode.from_list([
'with', '_loc', sub,
[
'seq', ['mstore', ['sub', '_loc', 32], 32],
[
'return', ['sub', '_loc', 32],
['ceil32', ['add', ['mload', '_loc'], 64]]
]
]
],
typ=None,
pos=getpos(self.stmt))
# Copying from storage
elif sub.location == 'storage':
# Instantiate a byte array at some index
fake_byte_array = LLLnode(self.context.get_next_mem() + 32,
typ=sub.typ,
location='memory',
pos=getpos(self.stmt))
o = [
'seq',
# Copy the data to this byte array
make_byte_array_copier(fake_byte_array, sub),
# Store the number 32 before it for ABI formatting purposes
['mstore', self.context.get_next_mem(), 32],
# Return it
[
'return',
self.context.get_next_mem(),
[
'add',
[
'ceil32',
['mload',
self.context.get_next_mem() + 32]
], 64
]
]
]
return LLLnode.from_list(o, typ=None, pos=getpos(self.stmt))
else:
raise Exception("Invalid location: %s" % sub.location)
elif isinstance(sub.typ, ListType):
sub_base_type = re.split(r'\(|\[', str(sub.typ.subtype))[0]
ret_base_type = re.split(r'\(|\[',
str(self.context.return_type.subtype))[0]
if sub_base_type != ret_base_type and sub.value != 'multi':
raise TypeMismatchException(
"List return type %r does not match specified return type, expecting %r"
% (sub_base_type, ret_base_type), self.stmt)
if sub.location == "memory" and sub.value != "multi":
return LLLnode.from_list([
'return', sub,
get_size_of_type(self.context.return_type) * 32
],
typ=None,
pos=getpos(self.stmt))
else:
new_sub = LLLnode.from_list(self.context.new_placeholder(
self.context.return_type),
typ=self.context.return_type,
location='memory')
setter = make_setter(new_sub,
sub,
'memory',
pos=getpos(self.stmt))
return LLLnode.from_list([
'seq', setter,
[
'return', new_sub,
get_size_of_type(self.context.return_type) * 32
]
],
typ=None,
pos=getpos(self.stmt))
# Returning a tuple.
elif isinstance(sub.typ, TupleType):
if len(self.context.return_type.members) != len(sub.typ.members):
raise StructureException("Tuple lengths don't match!")
subs = []
dynamic_offset_counter = LLLnode(
self.context.get_next_mem(),
typ=None,
annotation="dynamic_offset_counter"
) # dynamic offset position counter.
new_sub = LLLnode.from_list(self.context.get_next_mem() + 32,
typ=self.context.return_type,
location='memory',
annotation='new_sub')
keyz = list(range(len(sub.typ.members)))
dynamic_offset_start = 32 * len(
sub.args) # The static list of args end.
left_token = LLLnode.from_list('_loc',
typ=new_sub.typ,
location="memory")
def get_dynamic_offset_value():
# Get value of dynamic offset counter.
return ['mload', dynamic_offset_counter]
def increment_dynamic_offset(dynamic_spot):
# Increment dyanmic offset counter in memory.
return [
'mstore', dynamic_offset_counter,
[
'add',
['add', ['ceil32', ['mload', dynamic_spot]], 32],
['mload', dynamic_offset_counter]
]
]
for i, typ in enumerate(keyz):
arg = sub.args[i]
variable_offset = LLLnode.from_list(
['add', 32 * i, left_token],
typ=arg.typ,
annotation='variable_offset')
if isinstance(arg.typ, ByteArrayType):
# Store offset pointer value.
subs.append([
'mstore', variable_offset,
get_dynamic_offset_value()
])
# Store dynamic data, from offset pointer onwards.
dynamic_spot = LLLnode.from_list(
['add', left_token,
get_dynamic_offset_value()],
location="memory",
typ=arg.typ,
annotation='dynamic_spot')
subs.append(
make_setter(dynamic_spot,
arg,
location="memory",
pos=getpos(self.stmt)))
subs.append(increment_dynamic_offset(dynamic_spot))
elif isinstance(arg.typ, BaseType):
subs.append(
make_setter(variable_offset,
arg,
"memory",
pos=getpos(self.stmt)))
else:
raise Exception("Can't return type %s as part of tuple",
type(arg.typ))
setter = LLLnode.from_list([
'seq', [
'mstore', dynamic_offset_counter, dynamic_offset_start
], ['with', '_loc', new_sub, ['seq'] + subs]
],
typ=None)
return LLLnode.from_list([
'seq', setter, ['return', new_sub,
get_dynamic_offset_value()]
],
typ=None,
pos=getpos(self.stmt))
else:
raise TypeMismatchException("Can only return base type!",
self.stmt)
def parse_return(self):
from .parser import (parse_expr, make_setter)
if self.context.return_type is None:
if self.stmt.value:
raise TypeMismatchException("Not expecting to return a value",
self.stmt)
return LLLnode.from_list(['return', 0, 0],
typ=None,
pos=getpos(self.stmt))
if not self.stmt.value:
raise TypeMismatchException("Expecting to return a value",
self.stmt)
sub = parse_expr(self.stmt.value, self.context)
# Returning a value (most common case)
if isinstance(sub.typ, BaseType):
if not isinstance(self.context.return_type, BaseType):
raise TypeMismatchException(
"Trying to return base type %r, output expecting %r" %
(sub.typ, self.context.return_type), self.stmt.value)
sub = unwrap_location(sub)
if not are_units_compatible(sub.typ, self.context.return_type):
raise TypeMismatchException(
"Return type units mismatch %r %r" %
(sub.typ, self.context.return_type), self.stmt.value)
elif is_base_type(sub.typ, self.context.return_type.typ) or \
(is_base_type(sub.typ, 'num') and is_base_type(self.context.return_type, 'signed256')):
return LLLnode.from_list(
['seq', ['mstore', 0, sub], ['return', 0, 32]],
typ=None,
pos=getpos(self.stmt))
else:
raise TypeMismatchException(
"Unsupported type conversion: %r to %r" %
(sub.typ, self.context.return_type), self.stmt.value)
# Returning a byte array
elif isinstance(sub.typ, ByteArrayType):
if not isinstance(self.context.return_type, ByteArrayType):
raise TypeMismatchException(
"Trying to return base type %r, output expecting %r" %
(sub.typ, self.context.return_type), self.stmt.value)
if sub.typ.maxlen > self.context.return_type.maxlen:
raise TypeMismatchException(
"Cannot cast from greater max-length %d to shorter max-length %d"
% (sub.typ.maxlen, self.context.return_type.maxlen),
self.stmt.value)
# Returning something already in memory
if sub.location == 'memory':
return LLLnode.from_list([
'with', '_loc', sub,
[
'seq', ['mstore', ['sub', '_loc', 32], 32],
[
'return', ['sub', '_loc', 32],
['ceil32', ['add', ['mload', '_loc'], 64]]
]
]
],
typ=None,
pos=getpos(self.stmt))
# Copying from storage
elif sub.location == 'storage':
# Instantiate a byte array at some index
fake_byte_array = LLLnode(self.context.get_next_mem() + 32,
typ=sub.typ,
location='memory',
pos=getpos(self.stmt))
o = [
'seq',
# Copy the data to this byte array
make_byte_array_copier(fake_byte_array, sub),
# Store the number 32 before it for ABI formatting purposes
['mstore', self.context.get_next_mem(), 32],
# Return it
[
'return',
self.context.get_next_mem(),
[
'add',
[
'ceil32',
['mload',
self.context.get_next_mem() + 32]
], 64
]
]
]
return LLLnode.from_list(o, typ=None, pos=getpos(self.stmt))
else:
raise Exception("Invalid location: %s" % sub.location)
# Returning a list
elif isinstance(sub.typ, ListType):
if sub.location == "memory" and sub.value != "multi":
return LLLnode.from_list([
'return', sub,
get_size_of_type(self.context.return_type) * 32
],
typ=None,
pos=getpos(self.stmt))
else:
new_sub = LLLnode.from_list(self.context.new_placeholder(
self.context.return_type),
typ=self.context.return_type,
location='memory')
setter = make_setter(new_sub, sub, 'memory')
return LLLnode.from_list([
'seq', setter,
[
'return', new_sub,
get_size_of_type(self.context.return_type) * 32
]
],
typ=None,
pos=getpos(self.stmt))
else:
raise TypeMismatchException("Can only return base type!",
self.stmt)
