def parse_expression(expression, caller_context): """ Returns: str: expression """ # Expression # = Expression ('++' | '--') # | NewExpression # | IndexAccess # | MemberAccess # | FunctionCall # | '(' Expression ')' # | ('!' | '~' | 'delete' | '++' | '--' | '+' | '-') Expression # | Expression '**' Expression # | Expression ('*' | '/' | '%') Expression # | Expression ('+' | '-') Expression # | Expression ('<<' | '>>') Expression # | Expression '&' Expression # | Expression '^' Expression # | Expression '|' Expression # | Expression ('<' | '>' | '<=' | '>=') Expression # | Expression ('==' | '!=') Expression # | Expression '&&' Expression # | Expression '||' Expression # | Expression '?' Expression ':' Expression # | Expression ('=' | '|=' | '^=' | '&=' | '<<=' | '>>=' | '+=' | '-=' | '*=' | '/=' | '%=') Expression # | PrimaryExpression # The AST naming does not follow the spec name = expression[caller_context.get_key()] is_compact_ast = caller_context.is_compact_ast if name == 'UnaryOperation': if is_compact_ast: attributes = expression else: attributes = expression['attributes'] assert 'prefix' in attributes operation_type = UnaryOperationType.get_type(attributes['operator'], attributes['prefix']) if is_compact_ast: expression = parse_expression(expression['subExpression'], caller_context) else: assert len(expression['children']) == 1 expression = parse_expression(expression['children'][0], caller_context) unary_op = UnaryOperation(expression, operation_type) return unary_op elif name == 'BinaryOperation': if is_compact_ast: attributes = expression else: attributes = expression['attributes'] operation_type = BinaryOperationType.get_type(attributes['operator']) if is_compact_ast: left_expression = parse_expression(expression['leftExpression'], caller_context) right_expression = parse_expression(expression['rightExpression'], caller_context) else: assert len(expression['children']) == 2 left_expression = parse_expression(expression['children'][0], caller_context) right_expression = parse_expression(expression['children'][1], caller_context) binary_op = BinaryOperation(left_expression, right_expression, operation_type) return binary_op elif name == 'FunctionCall': return parse_call(expression, caller_context) elif name == 'TupleExpression': """ For expression like (a,,c) = (1,2,3) the AST provides only two children in the left side We check the type provided (tuple(uint256,,uint256)) To determine that there is an empty variable Otherwhise we would not be able to determine that a = 1, c = 3, and 2 is lost Note: this is only possible with Solidity >= 0.4.12 """ if is_compact_ast: expressions = [ parse_expression(e, caller_context) if e else None for e in expression['components'] ] else: if 'children' not in expression: attributes = expression['attributes'] components = attributes['components'] expressions = [ parse_expression(c, caller_context) if c else None for c in components ] else: expressions = [ parse_expression(e, caller_context) for e in expression['children'] ] # Add none for empty tuple items if "attributes" in expression: if "type" in expression['attributes']: t = expression['attributes']['type'] if ',,' in t or '(,' in t or ',)' in t: t = t[len('tuple('):-1] elems = t.split(',') for idx in range(len(elems)): if elems[idx] == '': expressions.insert(idx, None) t = TupleExpression(expressions) return t elif name == 'Conditional': if is_compact_ast: if_expression = parse_expression(expression['condition'], caller_context) then_expression = parse_expression(expression['trueExpression'], caller_context) else_expression = parse_expression(expression['falseExpression'], caller_context) else: children = expression['children'] assert len(children) == 3 if_expression = parse_expression(children[0], caller_context) then_expression = parse_expression(children[1], caller_context) else_expression = parse_expression(children[2], caller_context) conditional = ConditionalExpression(if_expression, then_expression, else_expression) return conditional elif name == 'Assignment': if is_compact_ast: left_expression = parse_expression(expression['leftHandSide'], caller_context) right_expression = parse_expression(expression['rightHandSide'], caller_context) operation_type = AssignmentOperationType.get_type( expression['operator']) operation_return_type = expression['typeDescriptions'][ 'typeString'] else: attributes = expression['attributes'] children = expression['children'] assert len(expression['children']) == 2 left_expression = parse_expression(children[0], caller_context) right_expression = parse_expression(children[1], caller_context) operation_type = AssignmentOperationType.get_type( attributes['operator']) operation_return_type = attributes['type'] assignement = AssignmentOperation(left_expression, right_expression, operation_type, operation_return_type) return assignement elif name == 'Literal': assert 'children' not in expression if is_compact_ast: value = expression['value'] if value: if 'subdenomination' in expression and expression[ 'subdenomination']: value = str( convert_subdenomination(value, expression['subdenomination'])) elif not value and value != "": value = '0x' + expression['hexValue'] type = expression['typeDescriptions']['typeString'] # Length declaration for array was None until solc 0.5.5 if type is None: if expression['kind'] == 'number': type = 'int_const' else: value = expression['attributes']['value'] if value: if 'subdenomination' in expression['attributes'] and expression[ 'attributes']['subdenomination']: value = str( convert_subdenomination( value, expression['attributes']['subdenomination'])) elif value is None: # for literal declared as hex # see https://solidity.readthedocs.io/en/v0.4.25/types.html?highlight=hex#hexadecimal-literals assert 'hexvalue' in expression['attributes'] value = '0x' + expression['attributes']['hexvalue'] type = expression['attributes']['type'] if type is None: if value.isdecimal(): type = ElementaryType('uint256') else: type = ElementaryType('string') elif type.startswith('int_const '): type = ElementaryType('uint256') elif type.startswith('bool'): type = ElementaryType('bool') elif type.startswith('address'): type = ElementaryType('address') else: type = ElementaryType('string') literal = Literal(value, type) return literal elif name == 'Identifier': assert 'children' not in expression t = None if caller_context.is_compact_ast: value = expression['name'] t = expression['typeDescriptions']['typeString'] else: value = expression['attributes']['value'] if 'type' in expression['attributes']: t = expression['attributes']['type'] if t: found = re.findall( '[struct|enum|function|modifier] \(([\[\] ()a-zA-Z0-9\.,_]*)\)', t) assert len(found) <= 1 if found: value = value + '(' + found[0] + ')' value = filter_name(value) if 'referencedDeclaration' in expression: referenced_declaration = expression['referencedDeclaration'] else: referenced_declaration = None var = find_variable(value, caller_context, referenced_declaration) identifier = Identifier(var) return identifier elif name == 'IndexAccess': if is_compact_ast: index_type = expression['typeDescriptions']['typeString'] left = expression['baseExpression'] right = expression['indexExpression'] else: index_type = expression['attributes']['type'] children = expression['children'] assert len(children) == 2 left = children[0] right = children[1] # IndexAccess is used to describe ElementaryTypeNameExpression # if abi.decode is used # For example, abi.decode(data, ...(uint[]) ) if right is None: return _parse_elementary_type_name_expression( left, is_compact_ast, caller_context) left_expression = parse_expression(left, caller_context) right_expression = parse_expression(right, caller_context) index = IndexAccess(left_expression, right_expression, index_type) return index elif name == 'MemberAccess': if caller_context.is_compact_ast: member_name = expression['memberName'] member_type = expression['typeDescriptions']['typeString'] member_expression = parse_expression(expression['expression'], caller_context) else: member_name = expression['attributes']['member_name'] member_type = expression['attributes']['type'] children = expression['children'] assert len(children) == 1 member_expression = parse_expression(children[0], caller_context) if str(member_expression) == 'super': super_name = parse_super_name(expression, is_compact_ast) if isinstance(caller_context, Contract): inheritance = caller_context.inheritance else: assert isinstance(caller_context, Function) inheritance = caller_context.contract.inheritance var = None for father in inheritance: try: var = find_variable(super_name, father) break except VariableNotFound: continue if var is None: raise VariableNotFound( 'Variable not found: {}'.format(super_name)) return SuperIdentifier(var) member_access = MemberAccess(member_name, member_type, member_expression) if str(member_access) in SOLIDITY_VARIABLES_COMPOSED: return Identifier(SolidityVariableComposed(str(member_access))) return member_access elif name == 'ElementaryTypeNameExpression': return _parse_elementary_type_name_expression(expression, is_compact_ast, caller_context) # NewExpression is not a root expression, it's always the child of another expression elif name == 'NewExpression': if is_compact_ast: type_name = expression['typeName'] else: children = expression['children'] assert len(children) == 1 type_name = children[0] if type_name[caller_context.get_key()] == 'ArrayTypeName': depth = 0 while type_name[caller_context.get_key()] == 'ArrayTypeName': # Note: dont conserve the size of the array if provided # We compute it directly if is_compact_ast: type_name = type_name['baseType'] else: type_name = type_name['children'][0] depth += 1 if type_name[caller_context.get_key()] == 'ElementaryTypeName': if is_compact_ast: array_type = ElementaryType(type_name['name']) else: array_type = ElementaryType( type_name['attributes']['name']) elif type_name[caller_context.get_key()] == 'UserDefinedTypeName': if is_compact_ast: array_type = parse_type(UnknownType(type_name['name']), caller_context) else: array_type = parse_type( UnknownType(type_name['attributes']['name']), caller_context) elif type_name[caller_context.get_key()] == 'FunctionTypeName': array_type = parse_type(type_name, caller_context) else: raise ParsingError('Incorrect type array {}'.format(type_name)) array = NewArray(depth, array_type) return array if type_name[caller_context.get_key()] == 'ElementaryTypeName': if is_compact_ast: elem_type = ElementaryType(type_name['name']) else: elem_type = ElementaryType(type_name['attributes']['name']) new_elem = NewElementaryType(elem_type) return new_elem assert type_name[caller_context.get_key()] == 'UserDefinedTypeName' if is_compact_ast: contract_name = type_name['name'] else: contract_name = type_name['attributes']['name'] new = NewContract(contract_name) return new elif name == 'ModifierInvocation': if is_compact_ast: called = parse_expression(expression['modifierName'], caller_context) arguments = [] if expression['arguments']: arguments = [ parse_expression(a, caller_context) for a in expression['arguments'] ] else: children = expression['children'] called = parse_expression(children[0], caller_context) arguments = [ parse_expression(a, caller_context) for a in children[1::] ] call = CallExpression(called, arguments, 'Modifier') return call raise ParsingError('Expression not parsed %s' % name)
def find_variable(var_name, caller_context, referenced_declaration=None): if isinstance(caller_context, Contract): function = None contract = caller_context elif isinstance(caller_context, Function): function = caller_context contract = function.contract else: raise ParsingError('Incorrect caller context') if function: # We look for variable declared with the referencedDeclaration attr func_variables = function.variables_renamed if referenced_declaration and referenced_declaration in func_variables: return func_variables[referenced_declaration] # If not found, check for name func_variables = function.variables_as_dict() if var_name in func_variables: return func_variables[var_name] # A local variable can be a pointer # for example # function test(function(uint) internal returns(bool) t) interna{ # Will have a local variable t which will match the signature # t(uint256) func_variables_ptr = { get_pointer_name(f): f for f in function.variables } if var_name and var_name in func_variables_ptr: return func_variables_ptr[var_name] contract_variables = contract.variables_as_dict() if var_name in contract_variables: return contract_variables[var_name] # A state variable can be a pointer conc_variables_ptr = {get_pointer_name(f): f for f in contract.variables} if var_name and var_name in conc_variables_ptr: return conc_variables_ptr[var_name] functions = contract.functions_as_dict() if var_name in functions: return functions[var_name] modifiers = contract.modifiers_as_dict() if var_name in modifiers: return modifiers[var_name] structures = contract.structures_as_dict() if var_name in structures: return structures[var_name] events = contract.events_as_dict() if var_name in events: return events[var_name] enums = contract.enums_as_dict() if var_name in enums: return enums[var_name] # If the enum is refered as its name rather than its canonicalName enums = {e.name: e for e in contract.enums} if var_name in enums: return enums[var_name] # Could refer to any enum all_enums = [c.enums_as_dict() for c in contract.slither.contracts] all_enums = {k: v for d in all_enums for k, v in d.items()} if var_name in all_enums: return all_enums[var_name] if var_name in SOLIDITY_VARIABLES: return SolidityVariable(var_name) if var_name in SOLIDITY_FUNCTIONS: return SolidityFunction(var_name) contracts = contract.slither.contracts_as_dict() if var_name in contracts: return contracts[var_name] if referenced_declaration: for contract in contract.slither.contracts: if contract.id == referenced_declaration: return contract for function in contract.slither.functions: if function.referenced_declaration == referenced_declaration: return function raise VariableNotFound('Variable not found: {} (context {})'.format( var_name, caller_context))
def find_variable(var_name, caller_context, referenced_declaration=None, is_super=False): # variable are looked from the contract declarer # functions can be shadowed, but are looked from the contract instance, rather than the contract declarer # the difference between function and variable come from the fact that an internal call, or an variable access # in a function does not behave similariy, for example in: # contract C{ # function f(){ # state_var = 1 # f2() # } # state_var will refer to C.state_var, no mater if C is inherited # while f2() will refer to the function definition of the inherited contract (C.f2() in the context of C, or # the contract inheriting from C) # for events it's unclear what should be the behavior, as they can be shadowed, but there is not impact # structure/enums cannot be shadowed if isinstance(caller_context, Contract): function = None contract = caller_context contract_declarer = caller_context elif isinstance(caller_context, Function): function = caller_context contract = function.contract contract_declarer = function.contract_declarer else: raise ParsingError('Incorrect caller context') if function: # We look for variable declared with the referencedDeclaration attr func_variables = function.variables_renamed if referenced_declaration and referenced_declaration in func_variables: return func_variables[referenced_declaration] # If not found, check for name func_variables = function.variables_as_dict() if var_name in func_variables: return func_variables[var_name] # A local variable can be a pointer # for example # function test(function(uint) internal returns(bool) t) interna{ # Will have a local variable t which will match the signature # t(uint256) func_variables_ptr = { get_pointer_name(f): f for f in function.variables } if var_name and var_name in func_variables_ptr: return func_variables_ptr[var_name] # variable are looked from the contract declarer contract_variables = contract_declarer.variables_as_dict() if var_name in contract_variables: return contract_variables[var_name] # A state variable can be a pointer conc_variables_ptr = { get_pointer_name(f): f for f in contract_declarer.variables } if var_name and var_name in conc_variables_ptr: return conc_variables_ptr[var_name] if is_super: getter_available = lambda f: f.functions_declared d = {f.canonical_name: f for f in contract.functions} functions = { f.full_name: f for f in contract_declarer.available_elements_from_inheritances( d, getter_available).values() } else: functions = contract.available_functions_as_dict() if var_name in functions: return functions[var_name] if is_super: getter_available = lambda m: m.modifiers_declared d = {m.canonical_name: m for m in contract.modifiers} modifiers = { m.full_name: m for m in contract_declarer.available_elements_from_inheritances( d, getter_available).values() } else: modifiers = contract.available_modifiers_as_dict() if var_name in modifiers: return modifiers[var_name] # structures are looked on the contract declarer structures = contract.structures_as_dict() if var_name in structures: return structures[var_name] events = contract.events_as_dict() if var_name in events: return events[var_name] enums = contract.enums_as_dict() if var_name in enums: return enums[var_name] # If the enum is refered as its name rather than its canonicalName enums = {e.name: e for e in contract.enums} if var_name in enums: return enums[var_name] # Could refer to any enum all_enums = [c.enums_as_dict() for c in contract.slither.contracts] all_enums = {k: v for d in all_enums for k, v in d.items()} if var_name in all_enums: return all_enums[var_name] if var_name in SOLIDITY_VARIABLES: return SolidityVariable(var_name) if var_name in SOLIDITY_FUNCTIONS: return SolidityFunction(var_name) contracts = contract.slither.contracts_as_dict() if var_name in contracts: return contracts[var_name] if referenced_declaration: for contract in contract.slither.contracts: if contract.id == referenced_declaration: return contract for function in contract.slither.functions: if function.referenced_declaration == referenced_declaration: return function raise VariableNotFound('Variable not found: {} (context {})'.format( var_name, caller_context))
def parse_expression(expression: Dict, caller_context: CallerContext) -> "Expression": # pylint: disable=too-many-nested-blocks,too-many-statements """ Returns: str: expression """ # Expression # = Expression ('++' | '--') # | NewExpression # | IndexAccess # | MemberAccess # | FunctionCall # | '(' Expression ')' # | ('!' | '~' | 'delete' | '++' | '--' | '+' | '-') Expression # | Expression '**' Expression # | Expression ('*' | '/' | '%') Expression # | Expression ('+' | '-') Expression # | Expression ('<<' | '>>') Expression # | Expression '&' Expression # | Expression '^' Expression # | Expression '|' Expression # | Expression ('<' | '>' | '<=' | '>=') Expression # | Expression ('==' | '!=') Expression # | Expression '&&' Expression # | Expression '||' Expression # | Expression '?' Expression ':' Expression # | Expression ('=' | '|=' | '^=' | '&=' | '<<=' | '>>=' | '+=' | '-=' | '*=' | '/=' | '%=') Expression # | PrimaryExpression # The AST naming does not follow the spec name = expression[caller_context.get_key()] is_compact_ast = caller_context.is_compact_ast src = expression["src"] if name == "UnaryOperation": if is_compact_ast: attributes = expression else: attributes = expression["attributes"] assert "prefix" in attributes operation_type = UnaryOperationType.get_type(attributes["operator"], attributes["prefix"]) if is_compact_ast: expression = parse_expression(expression["subExpression"], caller_context) else: assert len(expression["children"]) == 1 expression = parse_expression(expression["children"][0], caller_context) unary_op = UnaryOperation(expression, operation_type) unary_op.set_offset(src, caller_context.slither) return unary_op if name == "BinaryOperation": if is_compact_ast: attributes = expression else: attributes = expression["attributes"] operation_type = BinaryOperationType.get_type(attributes["operator"]) if is_compact_ast: left_expression = parse_expression(expression["leftExpression"], caller_context) right_expression = parse_expression(expression["rightExpression"], caller_context) else: assert len(expression["children"]) == 2 left_expression = parse_expression(expression["children"][0], caller_context) right_expression = parse_expression(expression["children"][1], caller_context) binary_op = BinaryOperation(left_expression, right_expression, operation_type) binary_op.set_offset(src, caller_context.slither) return binary_op if name in "FunctionCall": return parse_call(expression, caller_context) if name == "FunctionCallOptions": # call/gas info are handled in parse_call if is_compact_ast: called = parse_expression(expression["expression"], caller_context) else: called = parse_expression(expression["children"][0], caller_context) assert isinstance(called, (MemberAccess, NewContract, Identifier, TupleExpression)) return called if name == "TupleExpression": # For expression like # (a,,c) = (1,2,3) # the AST provides only two children in the left side # We check the type provided (tuple(uint256,,uint256)) # To determine that there is an empty variable # Otherwhise we would not be able to determine that # a = 1, c = 3, and 2 is lost # # Note: this is only possible with Solidity >= 0.4.12 if is_compact_ast: expressions = [ parse_expression(e, caller_context) if e else None for e in expression["components"] ] else: if "children" not in expression: attributes = expression["attributes"] components = attributes["components"] expressions = [ parse_expression(c, caller_context) if c else None for c in components ] else: expressions = [parse_expression(e, caller_context) for e in expression["children"]] # Add none for empty tuple items if "attributes" in expression: if "type" in expression["attributes"]: t = expression["attributes"]["type"] if ",," in t or "(," in t or ",)" in t: t = t[len("tuple(") : -1] elems = t.split(",") for idx, _ in enumerate(elems): if elems[idx] == "": expressions.insert(idx, None) t = TupleExpression(expressions) t.set_offset(src, caller_context.slither) return t if name == "Conditional": if is_compact_ast: if_expression = parse_expression(expression["condition"], caller_context) then_expression = parse_expression(expression["trueExpression"], caller_context) else_expression = parse_expression(expression["falseExpression"], caller_context) else: children = expression["children"] assert len(children) == 3 if_expression = parse_expression(children[0], caller_context) then_expression = parse_expression(children[1], caller_context) else_expression = parse_expression(children[2], caller_context) conditional = ConditionalExpression(if_expression, then_expression, else_expression) conditional.set_offset(src, caller_context.slither) return conditional if name == "Assignment": if is_compact_ast: left_expression = parse_expression(expression["leftHandSide"], caller_context) right_expression = parse_expression(expression["rightHandSide"], caller_context) operation_type = AssignmentOperationType.get_type(expression["operator"]) operation_return_type = expression["typeDescriptions"]["typeString"] else: attributes = expression["attributes"] children = expression["children"] assert len(expression["children"]) == 2 left_expression = parse_expression(children[0], caller_context) right_expression = parse_expression(children[1], caller_context) operation_type = AssignmentOperationType.get_type(attributes["operator"]) operation_return_type = attributes["type"] assignement = AssignmentOperation( left_expression, right_expression, operation_type, operation_return_type ) assignement.set_offset(src, caller_context.slither) return assignement if name == "Literal": subdenomination = None assert "children" not in expression if is_compact_ast: value = expression["value"] if value: if "subdenomination" in expression and expression["subdenomination"]: subdenomination = expression["subdenomination"] elif not value and value != "": value = "0x" + expression["hexValue"] type_candidate = expression["typeDescriptions"]["typeString"] # Length declaration for array was None until solc 0.5.5 if type_candidate is None: if expression["kind"] == "number": type_candidate = "int_const" else: value = expression["attributes"]["value"] if value: if ( "subdenomination" in expression["attributes"] and expression["attributes"]["subdenomination"] ): subdenomination = expression["attributes"]["subdenomination"] elif value is None: # for literal declared as hex # see https://solidity.readthedocs.io/en/v0.4.25/types.html?highlight=hex#hexadecimal-literals assert "hexvalue" in expression["attributes"] value = "0x" + expression["attributes"]["hexvalue"] type_candidate = expression["attributes"]["type"] if type_candidate is None: if value.isdecimal(): type_candidate = ElementaryType("uint256") else: type_candidate = ElementaryType("string") elif type_candidate.startswith("int_const "): type_candidate = ElementaryType("uint256") elif type_candidate.startswith("bool"): type_candidate = ElementaryType("bool") elif type_candidate.startswith("address"): type_candidate = ElementaryType("address") else: type_candidate = ElementaryType("string") literal = Literal(value, type_candidate, subdenomination) literal.set_offset(src, caller_context.slither) return literal if name == "Identifier": assert "children" not in expression t = None if caller_context.is_compact_ast: value = expression["name"] t = expression["typeDescriptions"]["typeString"] else: value = expression["attributes"]["value"] if "type" in expression["attributes"]: t = expression["attributes"]["type"] if t: found = re.findall("[struct|enum|function|modifier] \(([\[\] ()a-zA-Z0-9\.,_]*)\)", t) assert len(found) <= 1 if found: value = value + "(" + found[0] + ")" value = filter_name(value) if "referencedDeclaration" in expression: referenced_declaration = expression["referencedDeclaration"] else: referenced_declaration = None var = find_variable(value, caller_context, referenced_declaration) identifier = Identifier(var) identifier.set_offset(src, caller_context.slither) return identifier if name == "IndexAccess": if is_compact_ast: index_type = expression["typeDescriptions"]["typeString"] left = expression["baseExpression"] right = expression.get("indexExpression", None) else: index_type = expression["attributes"]["type"] children = expression["children"] left = children[0] right = children[1] if len(children) > 1 else None # IndexAccess is used to describe ElementaryTypeNameExpression # if abi.decode is used # For example, abi.decode(data, ...(uint[]) ) if right is None: ret = parse_expression(left, caller_context) # Nested array are not yet available in abi.decode if isinstance(ret, ElementaryTypeNameExpression): old_type = ret.type ret.type = ArrayType(old_type, None) return ret left_expression = parse_expression(left, caller_context) right_expression = parse_expression(right, caller_context) index = IndexAccess(left_expression, right_expression, index_type) index.set_offset(src, caller_context.slither) return index if name == "MemberAccess": if caller_context.is_compact_ast: member_name = expression["memberName"] member_type = expression["typeDescriptions"]["typeString"] # member_type = parse_type( # UnknownType(expression["typeDescriptions"]["typeString"]), caller_context # ) member_expression = parse_expression(expression["expression"], caller_context) else: member_name = expression["attributes"]["member_name"] member_type = expression["attributes"]["type"] # member_type = parse_type(UnknownType(expression["attributes"]["type"]), caller_context) children = expression["children"] assert len(children) == 1 member_expression = parse_expression(children[0], caller_context) if str(member_expression) == "super": super_name = parse_super_name(expression, is_compact_ast) var = find_variable(super_name, caller_context, is_super=True) if var is None: raise VariableNotFound("Variable not found: {}".format(super_name)) sup = SuperIdentifier(var) sup.set_offset(src, caller_context.slither) return sup member_access = MemberAccess(member_name, member_type, member_expression) member_access.set_offset(src, caller_context.slither) if str(member_access) in SOLIDITY_VARIABLES_COMPOSED: id_idx = Identifier(SolidityVariableComposed(str(member_access))) id_idx.set_offset(src, caller_context.slither) return id_idx return member_access if name == "ElementaryTypeNameExpression": return _parse_elementary_type_name_expression(expression, is_compact_ast, caller_context) # NewExpression is not a root expression, it's always the child of another expression if name == "NewExpression": if is_compact_ast: type_name = expression["typeName"] else: children = expression["children"] assert len(children) == 1 type_name = children[0] if type_name[caller_context.get_key()] == "ArrayTypeName": depth = 0 while type_name[caller_context.get_key()] == "ArrayTypeName": # Note: dont conserve the size of the array if provided # We compute it directly if is_compact_ast: type_name = type_name["baseType"] else: type_name = type_name["children"][0] depth += 1 if type_name[caller_context.get_key()] == "ElementaryTypeName": if is_compact_ast: array_type = ElementaryType(type_name["name"]) else: array_type = ElementaryType(type_name["attributes"]["name"]) elif type_name[caller_context.get_key()] == "UserDefinedTypeName": if is_compact_ast: array_type = parse_type(UnknownType(type_name["name"]), caller_context) else: array_type = parse_type( UnknownType(type_name["attributes"]["name"]), caller_context ) elif type_name[caller_context.get_key()] == "FunctionTypeName": array_type = parse_type(type_name, caller_context) else: raise ParsingError("Incorrect type array {}".format(type_name)) array = NewArray(depth, array_type) array.set_offset(src, caller_context.slither) return array if type_name[caller_context.get_key()] == "ElementaryTypeName": if is_compact_ast: elem_type = ElementaryType(type_name["name"]) else: elem_type = ElementaryType(type_name["attributes"]["name"]) new_elem = NewElementaryType(elem_type) new_elem.set_offset(src, caller_context.slither) return new_elem assert type_name[caller_context.get_key()] == "UserDefinedTypeName" if is_compact_ast: # Changed introduced in Solidity 0.8 # see https://github.com/crytic/slither/issues/794 # TODO explore more the changes introduced in 0.8 and the usage of pathNode/IdentifierPath if "name" not in type_name: assert "pathNode" in type_name and "name" in type_name["pathNode"] contract_name = type_name["pathNode"]["name"] else: contract_name = type_name["name"] else: contract_name = type_name["attributes"]["name"] new = NewContract(contract_name) new.set_offset(src, caller_context.slither) return new if name == "ModifierInvocation": if is_compact_ast: called = parse_expression(expression["modifierName"], caller_context) arguments = [] if expression.get("arguments", None): arguments = [parse_expression(a, caller_context) for a in expression["arguments"]] else: children = expression["children"] called = parse_expression(children[0], caller_context) arguments = [parse_expression(a, caller_context) for a in children[1::]] call = CallExpression(called, arguments, "Modifier") call.set_offset(src, caller_context.slither) return call if name == "IndexRangeAccess": # For now, we convert array slices to a direct array access # As a result the generated IR will lose the slices information # As far as I understand, array slice are only used in abi.decode # https://solidity.readthedocs.io/en/v0.6.12/types.html # TODO: Investigate array slices usage and implication for the IR base = parse_expression(expression["baseExpression"], caller_context) return base # Introduced with solc 0.8 if name == "IdentifierPath": if caller_context.is_compact_ast: value = expression["name"] if "referencedDeclaration" in expression: referenced_declaration = expression["referencedDeclaration"] else: referenced_declaration = None var = find_variable(value, caller_context, referenced_declaration) identifier = Identifier(var) identifier.set_offset(src, caller_context.slither) return identifier raise ParsingError("IdentifierPath not currently supported for the legacy ast") raise ParsingError("Expression not parsed %s" % name)
def find_variable( var_name: str, caller_context: CallerContext, referenced_declaration: Optional[int] = None, is_super=False, ) -> Union[ Variable, Function, Contract, SolidityVariable, SolidityFunction, Event, Enum, Structure, ]: from slither.solc_parsing.declarations.function import FunctionSolc from slither.solc_parsing.declarations.contract import ContractSolc # variable are looked from the contract declarer # functions can be shadowed, but are looked from the contract instance, rather than the contract declarer # the difference between function and variable come from the fact that an internal call, or an variable access # in a function does not behave similariy, for example in: # contract C{ # function f(){ # state_var = 1 # f2() # } # state_var will refer to C.state_var, no mater if C is inherited # while f2() will refer to the function definition of the inherited contract (C.f2() in the context of C, or # the contract inheriting from C) # for events it's unclear what should be the behavior, as they can be shadowed, but there is not impact # structure/enums cannot be shadowed direct_contracts, direct_functions_parser, sl, sl_parser = _find_variable_init(caller_context) all_contracts = sl.contracts all_functions_parser = sl_parser.all_functions_and_modifiers_parser # Look for all references delcaration # First look only in the context of function/contract # Then look everywhere # Because functions are copied between contracts, two functions can have the same ref # So we need to first look with respect to the direct context ret = _find_variable_from_ref_declaration( referenced_declaration, direct_contracts, direct_functions_parser ) if ret: return ret ret = _find_variable_from_ref_declaration( referenced_declaration, all_contracts, all_functions_parser ) if ret: return ret function_parser: Optional[FunctionSolc] = ( caller_context if isinstance(caller_context, FunctionSolc) else None ) ret = _find_variable_in_function_parser(var_name, function_parser, referenced_declaration) if ret: return ret contract: Optional[Contract] = None contract_declarer: Optional[Contract] = None if isinstance(caller_context, ContractSolc): contract = caller_context.underlying_contract contract_declarer = caller_context.underlying_contract elif isinstance(caller_context, FunctionSolc): underlying_func = caller_context.underlying_function # If contract_parser is set to None, then underlying_function is a functionContract assert isinstance(underlying_func, FunctionContract) contract = underlying_func.contract contract_declarer = underlying_func.contract_declarer ret = _find_in_contract(var_name, contract, contract_declarer, is_super) if ret: return ret # Could refer to any enum all_enumss = [c.enums_as_dict for c in sl.contracts] all_enums = {k: v for d in all_enumss for k, v in d.items()} if var_name in all_enums: return all_enums[var_name] contracts = sl.contracts_as_dict if var_name in contracts: return contracts[var_name] if var_name in SOLIDITY_VARIABLES: return SolidityVariable(var_name) if var_name in SOLIDITY_FUNCTIONS: return SolidityFunction(var_name) # Top level must be at the end, if nothing else was found ret = _find_top_level(var_name, sl) if ret: return ret raise VariableNotFound("Variable not found: {} (context {})".format(var_name, caller_context))
def find_variable( var_name: str, caller_context: CallerContext, referenced_declaration: Optional[int] = None, is_super=False, ) -> Union[Variable, Function, Contract, SolidityVariable, SolidityFunction, Event, Enum, Structure]: from slither.solc_parsing.declarations.contract import ContractSolc from slither.solc_parsing.declarations.function import FunctionSolc # variable are looked from the contract declarer # functions can be shadowed, but are looked from the contract instance, rather than the contract declarer # the difference between function and variable come from the fact that an internal call, or an variable access # in a function does not behave similariy, for example in: # contract C{ # function f(){ # state_var = 1 # f2() # } # state_var will refer to C.state_var, no mater if C is inherited # while f2() will refer to the function definition of the inherited contract (C.f2() in the context of C, or # the contract inheriting from C) # for events it's unclear what should be the behavior, as they can be shadowed, but there is not impact # structure/enums cannot be shadowed if isinstance(caller_context, ContractSolc): function: Optional[FunctionSolc] = None contract = caller_context.underlying_contract contract_declarer = caller_context.underlying_contract elif isinstance(caller_context, FunctionSolc): function = caller_context contract = function.underlying_function.contract contract_declarer = function.underlying_function.contract_declarer else: raise ParsingError("Incorrect caller context") if function: # We look for variable declared with the referencedDeclaration attr func_variables = function.variables_renamed if referenced_declaration and referenced_declaration in func_variables: return func_variables[referenced_declaration].underlying_variable # If not found, check for name func_variables = function.underlying_function.variables_as_dict if var_name in func_variables: return func_variables[var_name] # A local variable can be a pointer # for example # function test(function(uint) internal returns(bool) t) interna{ # Will have a local variable t which will match the signature # t(uint256) func_variables_ptr = { get_pointer_name(f): f for f in function.underlying_function.variables } if var_name and var_name in func_variables_ptr: return func_variables_ptr[var_name] # variable are looked from the contract declarer contract_variables = contract_declarer.variables_as_dict if var_name in contract_variables: return contract_variables[var_name] # A state variable can be a pointer conc_variables_ptr = { get_pointer_name(f): f for f in contract_declarer.variables } if var_name and var_name in conc_variables_ptr: return conc_variables_ptr[var_name] if is_super: getter_available = lambda f: f.functions_declared d = {f.canonical_name: f for f in contract.functions} functions = { f.full_name: f for f in contract_declarer.available_elements_from_inheritances( d, getter_available).values() } else: functions = contract.available_functions_as_dict() if var_name in functions: return functions[var_name] if is_super: getter_available = lambda m: m.modifiers_declared d = {m.canonical_name: m for m in contract.modifiers} modifiers = { m.full_name: m for m in contract_declarer.available_elements_from_inheritances( d, getter_available).values() } else: modifiers = contract.available_modifiers_as_dict() if var_name in modifiers: return modifiers[var_name] # structures are looked on the contract declarer structures = contract.structures_as_dict if var_name in structures: return structures[var_name] structures_top_level = contract.slither.top_level_structures for st in structures_top_level: if st.name == var_name: return st events = contract.events_as_dict if var_name in events: return events[var_name] enums = contract.enums_as_dict if var_name in enums: return enums[var_name] enums_top_level = contract.slither.top_level_enums for enum in enums_top_level: if enum.name == var_name: return enum # If the enum is refered as its name rather than its canonicalName enums = {e.name: e for e in contract.enums} if var_name in enums: return enums[var_name] # Could refer to any enum all_enums = [c.enums_as_dict for c in contract.slither.contracts] all_enums = {k: v for d in all_enums for k, v in d.items()} if var_name in all_enums: return all_enums[var_name] if var_name in SOLIDITY_VARIABLES: return SolidityVariable(var_name) if var_name in SOLIDITY_FUNCTIONS: return SolidityFunction(var_name) contracts = contract.slither.contracts_as_dict if var_name in contracts: return contracts[var_name] if referenced_declaration: # id of the contracts is the referenced declaration # This is not true for the functions, as we dont always have the referenced_declaration # But maybe we could? (TODO) for contract_candidate in contract.slither.contracts: if contract_candidate.id == referenced_declaration: return contract_candidate for function_candidate in caller_context.slither_parser.all_functions_parser: if function_candidate.referenced_declaration == referenced_declaration: return function_candidate.underlying_function raise VariableNotFound("Variable not found: {} (context {})".format( var_name, caller_context))
def find_variable( var_name: str, caller_context: CallerContextExpression, referenced_declaration: Optional[int] = None, is_super: bool = False, ) -> Tuple[ Union[ Variable, Function, Contract, SolidityVariable, SolidityFunction, Event, Enum, Structure, CustomError, TypeAlias, ], bool, ]: """ Return the variable found and a boolean indicating if the variable was created If the variable was created, it has no source mapping, and it the caller must add it :param var_name: :type var_name: :param caller_context: :type caller_context: :param referenced_declaration: :type referenced_declaration: :param is_super: :type is_super: :return: :rtype: """ from slither.solc_parsing.declarations.function import FunctionSolc from slither.solc_parsing.declarations.contract import ContractSolc # variable are looked from the contract declarer # functions can be shadowed, but are looked from the contract instance, rather than the contract declarer # the difference between function and variable come from the fact that an internal call, or an variable access # in a function does not behave similariy, for example in: # contract C{ # function f(){ # state_var = 1 # f2() # } # state_var will refer to C.state_var, no mater if C is inherited # while f2() will refer to the function definition of the inherited contract (C.f2() in the context of C, or # the contract inheriting from C) # for events it's unclear what should be the behavior, as they can be shadowed, but there is not impact # structure/enums cannot be shadowed direct_contracts, direct_functions, current_scope = _find_variable_init(caller_context) # Only look for reference declaration in the direct contract, see comment at the end # Reference looked are split between direct and all # Because functions are copied between contracts, two functions can have the same ref # So we need to first look with respect to the direct context if var_name in current_scope.renaming: var_name = current_scope.renaming[var_name] if var_name in current_scope.user_defined_types: return current_scope.user_defined_types[var_name], False # Use ret0/ret1 to help mypy ret0 = _find_variable_from_ref_declaration( referenced_declaration, direct_contracts, direct_functions ) if ret0: return ret0, False function_parser: Optional[FunctionSolc] = ( caller_context if isinstance(caller_context, FunctionSolc) else None ) ret1 = _find_variable_in_function_parser(var_name, function_parser, referenced_declaration) if ret1: return ret1, False contract: Optional[Contract] = None contract_declarer: Optional[Contract] = None if isinstance(caller_context, ContractSolc): contract = caller_context.underlying_contract contract_declarer = caller_context.underlying_contract elif isinstance(caller_context, FunctionSolc): underlying_func = caller_context.underlying_function if isinstance(underlying_func, FunctionContract): contract = underlying_func.contract contract_declarer = underlying_func.contract_declarer else: assert isinstance(underlying_func, FunctionTopLevel) ret = _find_in_contract(var_name, contract, contract_declarer, is_super) if ret: return ret, False # Could refer to any enum all_enumss = [c.enums_as_dict for c in current_scope.contracts.values()] all_enums = {k: v for d in all_enumss for k, v in d.items()} if var_name in all_enums: return all_enums[var_name], False contracts = current_scope.contracts if var_name in contracts: return contracts[var_name], False if var_name in SOLIDITY_VARIABLES: return SolidityVariable(var_name), False if var_name in SOLIDITY_FUNCTIONS: return SolidityFunction(var_name), False # Top level must be at the end, if nothing else was found ret, var_was_created = _find_top_level(var_name, current_scope) if ret: return ret, var_was_created # Look from reference declaration in all the contracts at the end # Because they are many instances where this can't be trusted # For example in # contract A{ # function _f() internal view returns(uint){ # return 1; # } # # function get() public view returns(uint){ # return _f(); # } # } # # contract B is A{ # function _f() internal view returns(uint){ # return 2; # } # # } # get's AST will say that the ref declaration for _f() is A._f(), but in the context of B, its not ret = _find_variable_from_ref_declaration( referenced_declaration, list(current_scope.contracts.values()), list(current_scope.functions), ) if ret: return ret, False raise VariableNotFound(f"Variable not found: {var_name} (context {contract})")