def parse_assert(self): with self.context.assertion_scope(): test_expr = Expr.parse_value_expr(self.stmt.test, self.context) if not self.is_bool_expr(test_expr): raise TypeMismatchException('Only boolean expressions allowed', self.stmt.test) if self.stmt.msg: if not isinstance(self.stmt.msg, ast.Str): raise StructureException( 'Reason parameter of assert needs to be a literal string.', self.stmt.msg) if len(self.stmt.msg.s.strip()) == 0: raise StructureException('Empty reason string not allowed.', self.stmt) reason_str = self.stmt.msg.s.strip() sig_placeholder = self.context.new_placeholder(BaseType(32)) arg_placeholder = self.context.new_placeholder(BaseType(32)) reason_str_type = ByteArrayType(len(reason_str)) placeholder_bytes = Expr(self.stmt.msg, self.context).lll_node method_id = fourbytes_to_int(sha3(b"Error(string)")[:4]) assert_reason = \ ['seq', ['mstore', sig_placeholder, method_id], ['mstore', arg_placeholder, 32], placeholder_bytes, ['assert_reason', test_expr, int(sig_placeholder + 28), int(4 + 32 + get_size_of_type(reason_str_type) * 32)]] return LLLnode.from_list(assert_reason, typ=None, pos=getpos(self.stmt)) else: return LLLnode.from_list(['assert', test_expr], typ=None, pos=getpos(self.stmt))
def _sha3(expr, args, kwargs, context): sub = args[0] # Can hash literals if isinstance(sub, bytes): return LLLnode.from_list(bytes_to_int(sha3(sub)), typ=BaseType('bytes32'), pos=getpos(expr)) # Can hash bytes32 objects if is_base_type(sub.typ, 'bytes32'): return LLLnode.from_list( ['seq', ['mstore', MemoryPositions.FREE_VAR_SPACE, sub], ['sha3', MemoryPositions.FREE_VAR_SPACE, 32]], typ=BaseType('bytes32'), pos=getpos(expr) ) # Copy the data to an in-memory array if sub.location == "memory": # If we are hashing a value in memory, no need to copy it, just hash in-place return LLLnode.from_list( ['with', '_sub', sub, ['sha3', ['add', '_sub', 32], ['mload', '_sub']]], typ=BaseType('bytes32'), pos=getpos(expr) ) elif sub.location == "storage": lengetter = LLLnode.from_list(['sload', ['sha3_32', '_sub']], typ=BaseType('int128')) else: # This should never happen, but just left here for future compiler-writers. raise Exception("Unsupported location: %s" % sub.location) # pragma: no test placeholder = context.new_placeholder(sub.typ) placeholder_node = LLLnode.from_list(placeholder, typ=sub.typ, location='memory') copier = make_byte_array_copier(placeholder_node, LLLnode.from_list('_sub', typ=sub.typ, location=sub.location)) return LLLnode.from_list( ['with', '_sub', sub, ['seq', copier, ['sha3', ['add', placeholder, 32], lengetter]]], typ=BaseType('bytes32'), pos=getpos(expr) )
def _assert_reason(self, test_expr, msg): if not isinstance(msg, ast.Str): raise StructureException( 'Reason parameter of assert needs to be a literal string.', msg) if len(msg.s.strip()) == 0: raise StructureException('Empty reason string not allowed.', self.stmt) reason_str = msg.s.strip() sig_placeholder = self.context.new_placeholder(BaseType(32)) arg_placeholder = self.context.new_placeholder(BaseType(32)) reason_str_type = ByteArrayType(len(reason_str)) placeholder_bytes = Expr(msg, self.context).lll_node method_id = fourbytes_to_int(sha3(b"Error(string)")[:4]) assert_reason = [ 'seq', ['mstore', sig_placeholder, method_id], ['mstore', arg_placeholder, 32], placeholder_bytes, [ 'assert_reason', test_expr, int(sig_placeholder + 28), int(4 + 32 + get_size_of_type(reason_str_type) * 32), ], ] return LLLnode.from_list(assert_reason, typ=None, pos=getpos(self.stmt))
def parse_assert(self): if self.stmt.msg: if len(self.stmt.msg.s.strip()) == 0: raise StructureException('Empty reason string not allowed.', self.stmt) reason_str = self.stmt.msg.s.strip() sig_placeholder = self.context.new_placeholder(BaseType(32)) arg_placeholder = self.context.new_placeholder(BaseType(32)) reason_str_type = ByteArrayType(len(reason_str)) placeholder_bytes = Expr(self.stmt.msg, self.context).lll_node method_id = fourbytes_to_int(sha3(b"Error(string)")[:4]) assert_reason = \ ['seq', ['mstore', sig_placeholder, method_id], ['mstore', arg_placeholder, 32], placeholder_bytes, ['assert_reason', Expr.parse_value_expr(self.stmt.test, self.context), int(sig_placeholder + 28), int(4 + 32 + get_size_of_type(reason_str_type) * 32)]] return LLLnode.from_list(assert_reason, typ=None, pos=getpos(self.stmt)) else: return LLLnode.from_list([ 'assert', Expr.parse_value_expr(self.stmt.test, self.context) ], typ=None, pos=getpos(self.stmt))
def from_declaration(cls, code, custom_units=None): name = code.target.id pos = 0 if not is_varname_valid(name, custom_units=custom_units): raise EventDeclarationException("Event name invalid: " + name) # 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] arg = keys[i].id is_indexed = False # Check to see if argument is a topic if isinstance(typ, 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, ast.Subscript) and getattr( typ.value, 'id', None ) == 'bytes' and typ.slice.value.n > 32 and is_indexed: raise EventDeclarationException( "Indexed arguments are limited to 32 bytes") if topics_count > 4: raise EventDeclarationException( "Maximum of 3 topics {} given".format(topics_count - 1), arg) if not isinstance(arg, str): raise VariableDeclarationException("Argument name invalid", arg) if not typ: raise InvalidTypeException("Argument must have type", arg) if not is_varname_valid(arg, custom_units): raise VariableDeclarationException( "Argument name invalid or reserved: " + arg, arg) if arg in (x.name for x in args): raise VariableDeclarationException( "Duplicate function argument name: " + arg, arg) parsed_type = parse_type(typ, None, custom_units=custom_units) 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(sha3(bytes(sig, 'utf-8'))) return cls(name, args, indexed_list, event_id, sig)
def method_id(expr, args, kwargs, context): if b' ' in args[0]: raise TypeMismatchException('Invalid function signature no spaces allowed.') method_id = fourbytes_to_int(sha3(args[0])[:4]) if args[1] == 'bytes32': return LLLnode(method_id, typ=BaseType('bytes32'), pos=getpos(expr)) elif args[1] == 'bytes[4]': placeholder = LLLnode.from_list(context.new_placeholder(ByteArrayType(4))) return LLLnode.from_list( ['seq', ['mstore', ['add', placeholder, 4], method_id], ['mstore', placeholder, 4], placeholder], typ=ByteArrayType(4), location='memory', pos=getpos(expr)) else: raise StructureException('Can only produce bytes32 or bytes[4] as outputs')
def from_definition(cls, code, sigs=None, custom_units=None, contract_def=False, constant=False): name = code.name pos = 0 if not is_varname_valid(name, custom_units=custom_units): raise FunctionDeclarationException("Function name invalid: " + name) # Determine the arguments, expects something of the form def foo(arg1: int128, arg2: int128 ... args = [] for arg in code.args.args: typ = arg.annotation if not typ: raise InvalidTypeException("Argument must have type", arg) if not is_varname_valid(arg.arg, custom_units=custom_units): raise FunctionDeclarationException( "Argument name invalid or reserved: " + arg.arg, arg) if arg.arg in (x.name for x in args): raise FunctionDeclarationException( "Duplicate function argument name: " + arg.arg, arg) parsed_type = parse_type(typ, None, sigs, custom_units=custom_units) args.append(VariableRecord(arg.arg, pos, parsed_type, False)) if isinstance(parsed_type, ByteArrayType): pos += 32 else: pos += get_size_of_type(parsed_type) * 32 # Apply decorators const, payable, private, public = False, False, False, False for dec in code.decorator_list: if isinstance(dec, ast.Name) and dec.id == "constant": const = True elif isinstance(dec, ast.Name) and dec.id == "payable": payable = True elif isinstance(dec, ast.Name) and dec.id == "private": private = True elif isinstance(dec, ast.Name) and dec.id == "public": public = True else: raise StructureException("Bad decorator", dec) if public and private: raise StructureException( "Cannot use public and private decorators on the same function: {}" .format(name)) if payable and const: raise StructureException( "Function {} cannot be both constant and payable.".format( name)) if payable and private: raise StructureException( "Function {} cannot be both private and payable.".format(name)) if (not public and not private) and not contract_def: raise StructureException( "Function visibility must be declared (@public or @private)", code) if constant: const = True # Determine the return type and whether or not it's constant. Expects something # of the form: # def foo(): ... # def foo() -> int128: ... # If there is no return type, ie. it's of the form def foo(): ... # and NOT def foo() -> type: ..., then it's null if not code.returns: output_type = None elif isinstance( code.returns, (ast.Name, ast.Compare, ast.Subscript, ast.Call, ast.Tuple)): output_type = parse_type(code.returns, None, sigs, custom_units=custom_units) else: raise InvalidTypeException( "Output type invalid or unsupported: %r" % parse_type(code.returns, None), code.returns, ) # Output type must be canonicalizable if output_type is not None: assert isinstance(output_type, TupleType) or canonicalize_type(output_type) # Get the canonical function signature sig = cls.get_full_sig(name, code.args.args, sigs, custom_units) # Take the first 4 bytes of the hash of the sig to get the method ID method_id = fourbytes_to_int(sha3(bytes(sig, 'utf-8'))[:4]) return cls(name, args, output_type, const, payable, private, sig, method_id, custom_units)
def method_id(expr, args, kwargs, context): method_id = fourbytes_to_int(sha3(args[0])[:4]) return LLLnode(method_id, typ=BaseType('method_id'), pos=getpos(expr))
def from_definition(cls, code, sigs=None, custom_units=None, custom_structs=None, contract_def=False, constants=None, constant=False): if not custom_structs: custom_structs = {} name = code.name mem_pos = 0 valid_name, msg = is_varname_valid(name, custom_units, custom_structs, constants) if not valid_name and (not name.lower() in function_whitelist): raise FunctionDeclarationException("Function name invalid. " + msg, code) # Validate default values. for default_value in getattr(code.args, 'defaults', []): if not isinstance(default_value, (ast.Num, ast.Str, ast.Bytes, ast.List)): raise FunctionDeclarationException( "Default parameter values have to be literals.") # Determine the arguments, expects something of the form def foo(arg1: # int128, arg2: int128 ... args = [] for arg in code.args.args: # Each arg needs a type specified. typ = arg.annotation if not typ: raise InvalidTypeException("Argument must have type", arg) # Validate arg name. check_valid_varname( arg.arg, custom_units, custom_structs, constants, arg, "Argument name invalid or reserved. ", FunctionDeclarationException, ) # Check for duplicate arg name. if arg.arg in (x.name for x in args): raise FunctionDeclarationException( "Duplicate function argument name: " + arg.arg, arg, ) parsed_type = parse_type( typ, None, sigs, custom_units=custom_units, custom_structs=custom_structs, constants=constants, ) args.append( VariableRecord( arg.arg, mem_pos, parsed_type, False, defined_at=getpos(arg), )) if isinstance(parsed_type, ByteArrayLike): mem_pos += 32 else: mem_pos += get_size_of_type(parsed_type) * 32 # Apply decorators const, payable, private, public, nonreentrant_key = False, False, False, False, '' for dec in code.decorator_list: if isinstance(dec, ast.Name) and dec.id == "constant": const = True elif isinstance(dec, ast.Name) and dec.id == "payable": payable = True elif isinstance(dec, ast.Name) and dec.id == "private": private = True elif isinstance(dec, ast.Name) and dec.id == "public": public = True elif isinstance(dec, ast.Call) and dec.func.id == "nonreentrant": if dec.args and len(dec.args) == 1 and isinstance( dec.args[0], ast.Str) and dec.args[0].s: # noqa: E501 nonreentrant_key = dec.args[0].s else: raise StructureException( "@nonreentrant decorator requires a non-empty string to use as a key.", dec) else: raise StructureException("Bad decorator", dec) if public and private: raise StructureException( "Cannot use public and private decorators on the same function: {}" .format(name)) if payable and const: raise StructureException( "Function {} cannot be both constant and payable.".format( name)) if payable and private: raise StructureException( "Function {} cannot be both private and payable.".format(name)) if (not public and not private) and not contract_def: raise StructureException( "Function visibility must be declared (@public or @private)", code, ) if constant and nonreentrant_key: raise StructureException( "@nonreentrant makes no sense on a @constant function.", code) if constant: const = True # Determine the return type and whether or not it's constant. Expects something # of the form: # def foo(): ... # def foo() -> int128: ... # If there is no return type, ie. it's of the form def foo(): ... # and NOT def foo() -> type: ..., then it's null if not code.returns: output_type = None elif isinstance( code.returns, (ast.Name, ast.Compare, ast.Subscript, ast.Call, ast.Tuple)): output_type = parse_type( code.returns, None, sigs, custom_units=custom_units, custom_structs=custom_structs, constants=constants, ) else: raise InvalidTypeException( "Output type invalid or unsupported: %r" % parse_type(code.returns, None), code.returns, ) # Output type must be canonicalizable if output_type is not None: assert isinstance(output_type, TupleType) or canonicalize_type(output_type) # Get the canonical function signature sig = cls.get_full_sig(name, code.args.args, sigs, custom_units, custom_structs, constants) # Take the first 4 bytes of the hash of the sig to get the method ID method_id = fourbytes_to_int(sha3(bytes(sig, 'utf-8'))[:4]) return cls(name, args, output_type, const, payable, private, nonreentrant_key, sig, method_id, custom_units, code)