def variables(self):
if self.expr.id == 'self':
return LLLnode.from_list(['address'], typ='address', pos=getpos(self.expr))
elif self.expr.id in self.context.vars:
var = self.context.vars[self.expr.id]
return LLLnode.from_list(
var.pos,
typ=var.typ,
location=var.location, # either 'memory' or 'calldata' storage is handled above.
pos=getpos(self.expr),
annotation=self.expr.id,
mutable=var.mutable,
)
elif self.expr.id in BUILTIN_CONSTANTS:
obj, typ = BUILTIN_CONSTANTS[self.expr.id]
return LLLnode.from_list(
[obj],
typ=BaseType(typ, is_literal=True),
pos=getpos(self.expr))
elif self.context.constants.ast_is_constant(self.expr):
return self.context.constants.get_constant(self.expr.id, self.context)
else:
raise VariableDeclarationException(f"Undeclared variable: {self.expr.id}", self.expr)
def _check_same_variable_assign(self, sub):
lhs_var_name = self.stmt.target.id
rhs_names = self._check_rhs_var_assn_recur(self.stmt.value)
if lhs_var_name in rhs_names:
raise VariableDeclarationException(
('Invalid variable assignment, same variable not allowed on '
f'LHS and RHS: {lhs_var_name}'))
else:
return True
def assign(self):
# Assignment (e.g. x[4] = y)
with self.context.assignment_scope():
sub = Expr(self.stmt.value, self.context).lll_node
# Error check when assigning to declared variable
if isinstance(self.stmt.target, sri_ast.Name):
# Do not allow assignment to undefined variables without annotation
if self.stmt.target.id not in self.context.vars:
raise VariableDeclarationException(
"Variable type not defined", self.stmt)
# Check against implicit conversion
self._check_implicit_conversion(self.stmt.target.id, sub)
is_valid_tuple_assign = (isinstance(
self.stmt.target, sri_ast.Tuple)) and isinstance(
self.stmt.value, sri_ast.Tuple)
# Do no allow tuple-to-tuple assignment
if is_valid_tuple_assign:
raise VariableDeclarationException(
"Tuple to tuple assignment not supported",
self.stmt,
)
# Checks to see if assignment is valid
target = self.get_target(self.stmt.target)
if isinstance(target.typ, ContractType) and not isinstance(
sub.typ, ContractType):
raise TypeMismatch(
'Contract assignment expects casted address: '
f'{target.typ}(<address_var>)', self.stmt)
o = make_setter(target,
sub,
target.location,
pos=getpos(self.stmt))
o.pos = getpos(self.stmt)
return o
def is_valid_varname(self, name, pos):
# Global context check first.
if self.global_ctx.is_valid_varname(name, pos):
check_valid_varname(
name,
custom_structs=self.structs,
constants=self.constants, pos=pos,
)
# Local context duplicate context check.
if any((name in self.vars, name in self.globals, name in self.constants)):
raise VariableDeclarationException(f"Duplicate variable name: {name}", name)
return True
def get_constant(self, const_name, context):
""" Return unrolled const """
# check if value is compatible with
const = self._constants[const_name]
if isinstance(const, sri_ast.AnnAssign): # Handle ByteArrays.
if context:
expr = Expr(const.value, context).lll_node
return expr
else:
raise VariableDeclarationException(
f"ByteArray: Can not be used outside of a function context: {const_name}"
)
# Other types are already unwrapped, no need
return self._constants[const_name]
def from_declaration(cls, code, global_ctx):
name = code.target.id
pos = 0
check_valid_varname(name,
global_ctx._structs,
global_ctx._constants,
pos=code,
error_prefix="Event name invalid. ",
exc=EventDeclarationException)
# Determine the arguments, expects something of the form def foo(arg1: num, arg2: num ...
args = []
indexed_list = []
topics_count = 1
if code.annotation.args:
keys = code.annotation.args[0].keys
values = code.annotation.args[0].values
for i in range(len(keys)):
typ = values[i]
if not isinstance(keys[i], sri_ast.Name):
raise EventDeclarationException(
'Invalid key type, expected a valid name.',
keys[i],
)
if not isinstance(
typ, (sri_ast.Name, sri_ast.Call, sri_ast.Subscript)):
raise EventDeclarationException(
'Invalid event argument type.', typ)
if isinstance(typ, sri_ast.Call) and not isinstance(
typ.func, sri_ast.Name):
raise EventDeclarationException(
'Invalid event argument type', typ)
arg = keys[i].id
arg_item = keys[i]
is_indexed = False
# Check to see if argument is a topic
if isinstance(typ, sri_ast.Call) and typ.func.id == 'indexed':
typ = values[i].args[0]
indexed_list.append(True)
topics_count += 1
is_indexed = True
else:
indexed_list.append(False)
if isinstance(typ, sri_ast.Subscript) and getattr(
typ.value, 'id', None
) == 'bytes' and typ.slice.value.n > 32 and is_indexed: # noqa: E501
raise EventDeclarationException(
"Indexed arguments are limited to 32 bytes")
if topics_count > 4:
raise EventDeclarationException(
f"Maximum of 3 topics {topics_count - 1} given",
arg,
)
if not isinstance(arg, str):
raise VariableDeclarationException("Argument name invalid",
arg)
if not typ:
raise InvalidType("Argument must have type", arg)
check_valid_varname(
arg,
global_ctx._structs,
global_ctx._constants,
pos=arg_item,
error_prefix="Event argument name invalid or reserved.",
)
if arg in (x.name for x in args):
raise VariableDeclarationException(
"Duplicate function argument name: " + arg,
arg_item,
)
# Can struct be logged?
parsed_type = global_ctx.parse_type(typ, None)
args.append(VariableRecord(arg, pos, parsed_type, False))
if isinstance(parsed_type, ByteArrayType):
pos += ceil32(typ.slice.value.n)
else:
pos += get_size_of_type(parsed_type) * 32
sig = name + '(' + ','.join([
canonicalize_type(arg.typ, indexed_list[pos])
for pos, arg in enumerate(args)
]) + ')' # noqa F812
event_id = bytes_to_int(keccak256(bytes(sig, 'utf-8')))
return cls(name, args, indexed_list, event_id, sig)
def external_contract_call(node,
context,
contract_name,
contract_address,
pos,
value=None,
gas=None):
from srilang.parser.expr import (
Expr, )
if value is None:
value = 0
if gas is None:
gas = 'gas'
if not contract_name:
raise StructureException(
f'Invalid external contract call "{node.func.attr}".', node)
if contract_name not in context.sigs:
raise VariableDeclarationException(
f'Contract "{contract_name}" not declared yet', node)
if contract_address.value == "address":
raise StructureException(f"External calls to self are not permitted.",
node)
method_name = node.func.attr
if method_name not in context.sigs[contract_name]:
raise FunctionDeclarationException((
f"Function not declared yet: {method_name} (reminder: "
"function must be declared in the correct contract)"
f"The available methods are: {','.join(context.sigs[contract_name].keys())}"
), node.func)
sig = context.sigs[contract_name][method_name]
inargs, inargsize, _ = pack_arguments(
sig,
[Expr(arg, context).lll_node for arg in node.args],
context,
node.func,
)
output_placeholder, output_size, returner = get_external_contract_call_output(
sig, context)
sub = [
'seq',
['assert', ['extcodesize', contract_address]],
['assert', ['ne', 'address', contract_address]],
]
if context.is_constant() and not sig.const:
raise ConstancyViolation(
f"May not call non-constant function '{method_name}' within {context.pp_constancy()}."
" For asserting the result of modifiable contract calls, try assert_modifiable.",
node)
if context.is_constant() or sig.const:
sub.append([
'assert',
[
'staticcall',
gas,
contract_address,
inargs,
inargsize,
output_placeholder,
output_size,
]
])
else:
sub.append([
'assert',
[
'call',
gas,
contract_address,
value,
inargs,
inargsize,
output_placeholder,
output_size,
]
])
sub.extend(returner)
o = LLLnode.from_list(sub,
typ=sig.output_type,
location='memory',
pos=getpos(node))
return o
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 TypeMismatch(
"Type mismatch: balance keyword expects an address as input",
self.expr
)
if (
isinstance(self.expr.value, sri_ast.Name) and
self.expr.value.id == "self" and
version_check(begin="istanbul")
):
seq = ['selfbalance']
else:
seq = ['balance', addr]
return LLLnode.from_list(
seq,
typ=BaseType('uint256'),
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 TypeMismatch(
"Type mismatch: codesize keyword expects an address as input",
self.expr,
)
if self.expr.attr == 'codesize':
eval_code = ['extcodesize', addr]
output_type = 'int128'
else:
eval_code = ['gt', ['extcodesize', addr], 0]
output_type = 'bool'
return LLLnode.from_list(
eval_code,
typ=BaseType(output_type),
location=None,
pos=getpos(self.expr),
)
# x.codehash: keccak of address x
elif self.expr.attr == 'codehash':
addr = Expr.parse_value_expr(self.expr.value, self.context)
if not is_base_type(addr.typ, 'address'):
raise TypeMismatch(
"codehash keyword expects an address as input",
self.expr,
)
if not version_check(begin="constantinople"):
raise EvmVersionException(
"address.codehash is unavailable prior to constantinople ruleset",
self.expr
)
return LLLnode.from_list(
['extcodehash', addr],
typ=BaseType('bytes32'),
location=None,
pos=getpos(self.expr)
)
# self.x: global attribute
elif isinstance(self.expr.value, sri_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, sri_ast.Name) and
self.expr.value.id in ENVIRONMENT_VARIABLES
):
key = self.expr.value.id + "." + self.expr.attr
if key == "msg.sender":
if self.context.is_private:
raise StructureException(
"msg.sender not allowed in private functions.", self.expr
)
return LLLnode.from_list(['caller'], typ='address', pos=getpos(self.expr))
elif key == "msg.value":
if not self.context.is_payable:
raise NonPayableViolation(
"Cannot use msg.value in a non-payable function", self.expr,
)
return LLLnode.from_list(
['callvalue'],
typ=BaseType('uint256'),
pos=getpos(self.expr),
)
elif key == "msg.gas":
return LLLnode.from_list(
['gas'],
typ='uint256',
pos=getpos(self.expr),
)
elif key == "block.difficulty":
return LLLnode.from_list(
['difficulty'],
typ='uint256',
pos=getpos(self.expr),
)
elif key == "block.timestamp":
return LLLnode.from_list(
['timestamp'],
typ=BaseType('uint256'),
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='uint256', 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))
elif key == "chain.id":
if not version_check(begin="istanbul"):
raise EvmVersionException(
"chain.id is unavailable prior to istanbul ruleset",
self.expr
)
return LLLnode.from_list(['chainid'], typ='uint256', pos=getpos(self.expr))
else:
raise StructureException("Unsupported keyword: " + key, self.expr)
# Other variables
else:
sub = Expr.parse_variable_location(self.expr.value, self.context)
# contract type
if isinstance(sub.typ, ContractType):
return sub
if not isinstance(sub.typ, StructType):
raise TypeMismatch(
"Type mismatch: member variable access not expected",
self.expr.value,
)
attrs = list(sub.typ.members.keys())
if self.expr.attr not in attrs:
raise TypeMismatch(
f"Member {self.expr.attr} not found. Only the following available: "
f"{' '.join(attrs)}",
self.expr,
)
return add_variable_offset(sub, self.expr.attr, pos=getpos(self.expr))