function.py

import logging
from typing import Dict, Optional, Union, List, TYPE_CHECKING, Tuple, Set

from slither.core.cfg.node import NodeType, link_nodes, insert_node, Node
from slither.core.cfg.scope import Scope
from slither.core.declarations.contract import Contract
from slither.core.declarations.function import (
    Function,
    ModifierStatements,
    FunctionType,
)
from slither.core.declarations.function_contract import FunctionContract
from slither.core.expressions import AssignmentOperation
from slither.core.source_mapping.source_mapping import Source
from slither.core.variables.local_variable import LocalVariable
from slither.core.variables.local_variable_init_from_tuple import LocalVariableInitFromTuple
from slither.solc_parsing.cfg.node import NodeSolc
from slither.solc_parsing.declarations.caller_context import CallerContextExpression
from slither.solc_parsing.exceptions import ParsingError
from slither.solc_parsing.expressions.expression_parsing import parse_expression
from slither.solc_parsing.variables.local_variable import LocalVariableSolc
from slither.solc_parsing.variables.local_variable_init_from_tuple import (
    LocalVariableInitFromTupleSolc,
)
from slither.solc_parsing.variables.variable_declaration import MultipleVariablesDeclaration
from slither.utils.expression_manipulations import SplitTernaryExpression
from slither.visitors.expression.export_values import ExportValues
from slither.visitors.expression.has_conditional import HasConditional
from slither.solc_parsing.yul.parse_yul import YulBlock

if TYPE_CHECKING:
    from slither.core.expressions.expression import Expression
    from slither.solc_parsing.declarations.contract import ContractSolc
    from slither.solc_parsing.slither_compilation_unit_solc import SlitherCompilationUnitSolc
    from slither.core.compilation_unit import SlitherCompilationUnit


LOGGER = logging.getLogger("FunctionSolc")


def link_underlying_nodes(node1: NodeSolc, node2: NodeSolc):
    link_nodes(node1.underlying_node, node2.underlying_node)


# pylint: disable=too-many-lines,too-many-branches,too-many-locals,too-many-statements,too-many-instance-attributes


class FunctionSolc(CallerContextExpression):

    # elems = [(type, name)]

    def __init__(
        self,
        function: Function,
        function_data: Dict,
        contract_parser: Optional["ContractSolc"],
        slither_parser: "SlitherCompilationUnitSolc",
    ) -> None:
        self._slither_parser: "SlitherCompilationUnitSolc" = slither_parser
        self._contract_parser = contract_parser
        self._function = function

        # Only present if compact AST
        if self.is_compact_ast:
            self._function.name = function_data["name"]
        else:
            self._function.name = function_data["attributes"][self.get_key()]

        if "id" in function_data:
            self._function.id = function_data["id"]

        self._functionNotParsed = function_data
        self._returnsNotParsed: List[dict] = []
        self._params_was_analyzed = False
        self._content_was_analyzed = False

        self._counter_scope_local_variables = 0
        # variable renamed will map the solc id
        # to the variable. It only works for compact format
        # Later if an expression provides the referencedDeclaration attr
        # we can retrieve the variable
        # It only matters if two variables have the same name in the function
        # which is only possible with solc > 0.5
        self._variables_renamed: Dict[
            int, Union[LocalVariableSolc, LocalVariableInitFromTupleSolc]
        ] = {}

        self._analyze_type()

        self._node_to_nodesolc: Dict[Node, NodeSolc] = {}
        self._node_to_yulobject: Dict[Node, YulBlock] = {}

        self._local_variables_parser: List[
            Union[LocalVariableSolc, LocalVariableInitFromTupleSolc]
        ] = []

        if "documentation" in function_data:
            function.has_documentation = True

    @property
    def underlying_function(self) -> Function:
        return self._function

    @property
    def contract_parser(self) -> Optional["ContractSolc"]:
        return self._contract_parser

    @property
    def slither_parser(self) -> "SlitherCompilationUnitSolc":
        return self._slither_parser

    @property
    def compilation_unit(self) -> "SlitherCompilationUnit":
        return self._function.compilation_unit

    ###################################################################################
    ###################################################################################
    # region AST format
    ###################################################################################
    ###################################################################################

    def get_key(self) -> str:
        return self._slither_parser.get_key()

    def get_children(self, key: str) -> str:
        if self.is_compact_ast:
            return key
        return "children"

    @property
    def is_compact_ast(self):
        return self._slither_parser.is_compact_ast

    # endregion
    ###################################################################################
    ###################################################################################
    # region Variables
    ###################################################################################
    ###################################################################################

    @property
    def variables_renamed(
        self,
    ) -> Dict[int, Union[LocalVariableSolc, LocalVariableInitFromTupleSolc]]:
        return self._variables_renamed

    def _add_local_variable(
        self, local_var_parser: Union[LocalVariableSolc, LocalVariableInitFromTupleSolc]
    ) -> None:
        # If two local variables have the same name
        # We add a suffix to the new variable
        # This is done to prevent collision during SSA translation
        # Use of while in case of collision
        # In the worst case, the name will be really long
        if local_var_parser.underlying_variable.name:
            known_variables = [v.name for v in self._function.variables]
            while local_var_parser.underlying_variable.name in known_variables:
                local_var_parser.underlying_variable.name += (
                    f"_scope_{self._counter_scope_local_variables}"
                )
                self._counter_scope_local_variables += 1
                known_variables = [v.name for v in self._function.variables]
        if local_var_parser.reference_id is not None:
            self._variables_renamed[local_var_parser.reference_id] = local_var_parser
        self._function.variables_as_dict[
            local_var_parser.underlying_variable.name
        ] = local_var_parser.underlying_variable
        self._local_variables_parser.append(local_var_parser)

    # endregion
    ###################################################################################
    ###################################################################################
    # region Analyses
    ###################################################################################
    ###################################################################################

    @property
    def function_not_parsed(self) -> Dict:
        return self._functionNotParsed

    def _analyze_type(self) -> None:
        """
        Analyz the type of the function
        Myst be called in the constructor as the name might change according to the function's type
        For example both the fallback and the receiver will have an empty name
        :return:
        """
        if self.is_compact_ast:
            attributes = self._functionNotParsed
        else:
            attributes = self._functionNotParsed["attributes"]

        if self._function.name == "":
            self._function.function_type = FunctionType.FALLBACK
            # 0.6.x introduced the receiver function
            # It has also an empty name, so we need to check the kind attribute
            if "kind" in attributes:
                if attributes["kind"] == "receive":
                    self._function.function_type = FunctionType.RECEIVE
        else:
            self._function.function_type = FunctionType.NORMAL

        if isinstance(self._function, FunctionContract):
            if self._function.name == self._function.contract_declarer.name:
                self._function.function_type = FunctionType.CONSTRUCTOR

    def _analyze_attributes(self) -> None:
        if self.is_compact_ast:
            attributes = self._functionNotParsed
        else:
            attributes = self._functionNotParsed["attributes"]

        if "stateMutability" in attributes:
            if attributes["stateMutability"] == "payable":
                self._function.payable = True
            elif attributes["stateMutability"] == "pure":
                self._function.pure = True
                self._function.view = True
            elif attributes["stateMutability"] == "view":
                self._function.view = True

        if "constant" in attributes:
            self._function.view = attributes["constant"]

        if "isConstructor" in attributes and attributes["isConstructor"]:
            self._function.function_type = FunctionType.CONSTRUCTOR

        if "kind" in attributes:
            if attributes["kind"] == "constructor":
                self._function.function_type = FunctionType.CONSTRUCTOR

        if "visibility" in attributes:
            self._function.visibility = attributes["visibility"]
        # old solc
        elif "public" in attributes:
            if attributes["public"]:
                self._function.visibility = "public"
            else:
                self._function.visibility = "private"
        else:
            self._function.visibility = "public"

        if "payable" in attributes:
            self._function.payable = attributes["payable"]

        if "baseFunctions" in attributes:
            overrides_ids = attributes["baseFunctions"]
            if len(overrides_ids) > 0:
                for f_id in overrides_ids:
                    funcs = self.slither_parser.functions_by_id[f_id]
                    for f in funcs:
                        # Do not consider leaf contracts as overrides.
                        # B is A { function a() override {} } and C is A { function a() override {} } override A.a(), not each other.
                        if (
                            f.contract == self._function.contract
                            or f.contract in self._function.contract.inheritance
                        ):
                            self._function.overrides.append(f)
                            f.overridden_by.append(self._function)

        # Attaches reference to override specifier e.g. X is referenced by `function a() override(X)`
        if "overrides" in attributes and isinstance(attributes["overrides"], dict):
            for override in attributes["overrides"].get("overrides", []):
                refId = override["referencedDeclaration"]
                overridden_contract = self.slither_parser.contracts_by_id.get(refId, None)
                if overridden_contract:
                    overridden_contract.add_reference_from_raw_source(
                        override["src"], self.compilation_unit
                    )

        if "virtual" in attributes:
            self._function.is_virtual = attributes["virtual"]

    def analyze_params(self) -> None:
        # Can be re-analyzed due to inheritance
        if self._params_was_analyzed:
            return

        self._params_was_analyzed = True

        self._analyze_attributes()

        if self.is_compact_ast:
            params = self._functionNotParsed["parameters"]
            returns = self._functionNotParsed["returnParameters"]
        else:
            children = self._functionNotParsed[self.get_children("children")]
            # It uses to be
            # params = children[0]
            # returns = children[1]
            # But from Solidity 0.6.3 to 0.6.10 (included)
            # Comment above a function might be added in the children
            child_iter = iter(
                [child for child in children if child[self.get_key()] == "ParameterList"]
            )
            params = next(child_iter)
            returns = next(child_iter)

        if params:
            self._parse_params(params)
        if returns:
            self._parse_returns(returns)

    def analyze_content(self) -> None:
        if self._content_was_analyzed:
            return

        self._content_was_analyzed = True

        if self.is_compact_ast:
            body = self._functionNotParsed.get("body", None)
            return_params = self._functionNotParsed.get("returnParameters", None)

            if body and body[self.get_key()] == "Block":
                self._function.is_implemented = True
                self._parse_cfg(body)

            for modifier in self._functionNotParsed["modifiers"]:
                self._parse_modifier(modifier)

        else:
            children = self._functionNotParsed[self.get_children("children")]
            return_params = children[1]
            self._function.is_implemented = False
            for child in children[2:]:
                if child[self.get_key()] == "Block":
                    self._function.is_implemented = True
                    self._parse_cfg(child)

            # Parse modifier after parsing all the block
            # In the case a local variable is used in the modifier
            for child in children[2:]:
                if child[self.get_key()] == "ModifierInvocation":
                    self._parse_modifier(child)

        for local_var_parser in self._local_variables_parser:
            local_var_parser.analyze(self)

        for node_parser in self._node_to_nodesolc.values():
            node_parser.analyze_expressions(self)

        for yul_parser in self._node_to_yulobject.values():
            yul_parser.analyze_expressions()

        self._rewrite_ternary_as_if_else()

        self._remove_alone_endif()

        if return_params:
            self._fix_implicit_return(return_params)

        if self._function.entry_point:
            self._update_reachability(self._function.entry_point)

    # endregion
    ###################################################################################
    ###################################################################################
    # region Nodes
    ###################################################################################
    ###################################################################################

    def _new_node(
        self, node_type: NodeType, src: Union[str, Source], scope: Union[Scope, "Function"]
    ) -> NodeSolc:
        node = self._function.new_node(node_type, src, scope)
        node_parser = NodeSolc(node)
        self._node_to_nodesolc[node] = node_parser
        return node_parser

    def _new_yul_block(
        self, src: Union[str, Dict], father_scope: Union[Scope, Function]
    ) -> YulBlock:
        scope = Scope(False, True, father_scope)
        node = self._function.new_node(NodeType.ASSEMBLY, src, scope)
        contract = None
        if isinstance(self._function, FunctionContract):
            contract = self._function.contract
        yul_object = YulBlock(
            contract,
            node,
            [self._function.name, f"asm_{len(self._node_to_yulobject)}"],
            scope,
        )
        self._node_to_yulobject[node] = yul_object
        return yul_object

    # endregion
    ###################################################################################
    ###################################################################################
    # region Parsing function
    ###################################################################################
    ###################################################################################

    def _parse_if(self, if_statement: Dict, node: NodeSolc, scope: Scope) -> NodeSolc:
        # IfStatement = 'if' '(' Expression ')' Statement ( 'else' Statement )?
        falseStatement = None

        if self.is_compact_ast:
            condition = if_statement["condition"]
            # Note: check if the expression could be directly
            # parsed here
            condition_node = self._new_node(NodeType.IF, condition["src"], scope)
            condition_node.add_unparsed_expression(condition)
            link_underlying_nodes(node, condition_node)
            true_scope = Scope(scope.is_checked, False, scope)
            trueStatement = self._parse_statement(
                if_statement["trueBody"], condition_node, true_scope
            )
            if "falseBody" in if_statement and if_statement["falseBody"]:
                false_scope = Scope(scope.is_checked, False, scope)
                falseStatement = self._parse_statement(
                    if_statement["falseBody"], condition_node, false_scope
                )
        else:
            children = if_statement[self.get_children("children")]
            condition = children[0]
            # Note: check if the expression could be directly
            # parsed here
            condition_node = self._new_node(NodeType.IF, condition["src"], scope)
            condition_node.add_unparsed_expression(condition)
            link_underlying_nodes(node, condition_node)
            true_scope = Scope(scope.is_checked, False, scope)
            trueStatement = self._parse_statement(children[1], condition_node, true_scope)
            if len(children) == 3:
                false_scope = Scope(scope.is_checked, False, scope)
                falseStatement = self._parse_statement(children[2], condition_node, false_scope)

        endIf_node = self._new_node(NodeType.ENDIF, if_statement["src"], scope)
        link_underlying_nodes(trueStatement, endIf_node)

        if falseStatement:
            link_underlying_nodes(falseStatement, endIf_node)
        else:
            link_underlying_nodes(condition_node, endIf_node)
        return endIf_node

    def _parse_while(self, whilte_statement: Dict, node: NodeSolc, scope: Scope) -> NodeSolc:
        # WhileStatement = 'while' '(' Expression ')' Statement

        node_startWhile = self._new_node(NodeType.STARTLOOP, whilte_statement["src"], scope)

        body_scope = Scope(scope.is_checked, False, scope)
        if self.is_compact_ast:
            node_condition = self._new_node(
                NodeType.IFLOOP, whilte_statement["condition"]["src"], scope
            )
            node_condition.add_unparsed_expression(whilte_statement["condition"])
            statement = self._parse_statement(whilte_statement["body"], node_condition, body_scope)
        else:
            children = whilte_statement[self.get_children("children")]
            expression = children[0]
            node_condition = self._new_node(NodeType.IFLOOP, expression["src"], scope)
            node_condition.add_unparsed_expression(expression)
            statement = self._parse_statement(children[1], node_condition, body_scope)

        node_endWhile = self._new_node(NodeType.ENDLOOP, whilte_statement["src"], scope)

        link_underlying_nodes(node, node_startWhile)
        link_underlying_nodes(node_startWhile, node_condition)
        link_underlying_nodes(statement, node_condition)
        link_underlying_nodes(node_condition, node_endWhile)

        return node_endWhile

    def _parse_for_compact_ast(
        self, statement: Dict
    ) -> Tuple[Optional[Dict], Optional[Dict], Optional[Dict], Dict]:
        body = statement["body"]
        init_expression = statement.get("initializationExpression", None)
        condition = statement.get("condition", None)
        loop_expression = statement.get("loopExpression", None)

        return init_expression, condition, loop_expression, body

    def _parse_for_legacy_ast(
        self, statement: Dict
    ) -> Tuple[Optional[Dict], Optional[Dict], Optional[Dict], Dict]:
        # if we're using an old version of solc (anything below and including 0.4.11) or if the user
        # explicitly enabled compact ast, we might need to make some best-effort guesses
        children = statement[self.get_children("children")]

        # there should always be at least one, and never more than 4, children
        assert 1 <= len(children) <= 4

        # the last element of the children array must be the body, since it's mandatory
        # however, it might be a single expression
        body = children[-1]

        if len(children) == 4:
            # handle the first trivial case - if there are four children we know exactly what they are
            pre, cond, post = children[0], children[1], children[2]
        elif len(children) == 1:
            # handle the second trivial case - if there is only one child we know there are no expressions
            pre, cond, post = None, None, None
        else:
            attributes = statement.get("attributes", None)

            def has_hint(key):
                return key in attributes and not attributes[key]

            if attributes and any(
                map(
                    has_hint,
                    ["condition", "initializationExpression", "loopExpression"],
                )
            ):
                # if we have attribute hints, rely on those

                if len(children) == 2:
                    # we're missing two expressions, find the one we have
                    if not has_hint("initializationExpression"):
                        pre, cond, post = children[0], None, None
                    elif not has_hint("condition"):
                        pre, cond, post = None, children[0], None
                    else:  # if not has_hint('loopExpression'):
                        pre, cond, post = None, None, children[0]
                else:  # len(children) == 3
                    # we're missing one expression, figure out what it is
                    if has_hint("initializationExpression"):
                        pre, cond, post = None, children[0], children[1]
                    elif has_hint("condition"):
                        pre, cond, post = children[0], None, children[1]
                    else:  # if has_hint('loopExpression'):
                        pre, cond, post = children[0], children[1], None
            else:
                # we don't have attribute hints, and it's impossible to be 100% accurate here
                # let's just try our best

                first_type = children[0][self.get_key()]
                second_type = children[1][self.get_key()]

                # VariableDefinitionStatement is used by solc 0.4.0-0.4.6
                # it's changed in 0.4.7 to VariableDeclarationStatement
                if first_type in ["VariableDefinitionStatement", "VariableDeclarationStatement"]:
                    # only the pre statement can be a variable declaration

                    if len(children) == 2:
                        # only one child apart from body, it must be pre
                        pre, cond, post = children[0], None, None
                    else:
                        # more than one child, figure out which one is the cond
                        if second_type == "ExpressionStatement":
                            # only the post can be an expression statement
                            pre, cond, post = children[0], None, children[1]
                        else:
                            # similarly, the post cannot be anything other than an expression statement
                            pre, cond, post = children[0], children[1], None
                elif first_type == "ExpressionStatement":
                    # the first element can either be pre or post

                    if len(children) == 2:
                        # this is entirely ambiguous, so apply a very dumb heuristic:
                        # if the statement is closer to the start of the body, it's probably the post
                        # otherwise, it's probably the pre
                        # this will work in all cases where the formatting isn't completely borked

                        node_len = int(children[0]["src"].split(":")[1])

                        node_start = int(children[0]["src"].split(":")[0])
                        node_end = node_start + node_len

                        for_start = int(statement["src"].split(":")[0]) + 3  # trim off the 'for'
                        body_start = int(body["src"].split(":")[0])

                        dist_start = node_start - for_start
                        dist_end = body_start - node_end
                        if dist_start > dist_end:
                            pre, cond, post = None, None, children[0]
                        else:
                            pre, cond, post = children[0], None, None
                    else:
                        # more than one child, we must be the pre
                        pre, cond, post = children[0], children[1], None
                else:
                    # the first element must be the cond

                    if len(children) == 2:
                        pre, cond, post = None, children[0], None
                    else:
                        pre, cond, post = None, children[0], children[1]

        return pre, cond, post, body

    def _parse_for(self, statement: Dict, node: NodeSolc, scope: Scope) -> NodeSolc:
        # ForStatement = 'for' '(' (SimpleStatement)? ';' (Expression)? ';' (ExpressionStatement)? ')' Statement

        if self.is_compact_ast:
            pre, cond, post, body = self._parse_for_compact_ast(statement)
        else:
            pre, cond, post, body = self._parse_for_legacy_ast(statement)

        node_startLoop = self._new_node(NodeType.STARTLOOP, statement["src"], scope)
        node_endLoop = self._new_node(NodeType.ENDLOOP, statement["src"], scope)

        last_scope = scope

        if pre:
            pre_scope = Scope(scope.is_checked, False, last_scope)
            last_scope = pre_scope
            node_init_expression = self._parse_statement(pre, node, pre_scope)
            link_underlying_nodes(node_init_expression, node_startLoop)
        else:
            link_underlying_nodes(node, node_startLoop)

        if cond:
            cond_scope = Scope(scope.is_checked, False, last_scope)
            last_scope = cond_scope
            node_condition = self._new_node(NodeType.IFLOOP, cond["src"], cond_scope)
            node_condition.add_unparsed_expression(cond)
            link_underlying_nodes(node_startLoop, node_condition)

            node_beforeBody = node_condition
        else:
            node_condition = None
            node_beforeBody = node_startLoop

        body_scope = Scope(scope.is_checked, False, last_scope)
        last_scope = body_scope
        node_body = self._parse_statement(body, node_beforeBody, body_scope)

        if post:
            node_loopexpression = self._parse_statement(post, node_body, last_scope)
            link_underlying_nodes(node_loopexpression, node_beforeBody)
        else:
            # node_loopexpression = None
            link_underlying_nodes(node_body, node_beforeBody)

        if node_condition:
            link_underlying_nodes(node_condition, node_endLoop)
        else:
            link_underlying_nodes(
                node_startLoop, node_endLoop
            )  # this is an infinite loop but we can't break our cfg

        return node_endLoop

    def _parse_dowhile(self, do_while_statement: Dict, node: NodeSolc, scope: Scope) -> NodeSolc:

        node_startDoWhile = self._new_node(NodeType.STARTLOOP, do_while_statement["src"], scope)
        condition_scope = Scope(scope.is_checked, False, scope)

        if self.is_compact_ast:
            node_condition = self._new_node(
                NodeType.IFLOOP, do_while_statement["condition"]["src"], condition_scope
            )
            node_condition.add_unparsed_expression(do_while_statement["condition"])
            statement = self._parse_statement(
                do_while_statement["body"], node_condition, condition_scope
            )
        else:
            children = do_while_statement[self.get_children("children")]
            # same order in the AST as while
            expression = children[0]
            node_condition = self._new_node(NodeType.IFLOOP, expression["src"], condition_scope)
            node_condition.add_unparsed_expression(expression)
            statement = self._parse_statement(children[1], node_condition, condition_scope)

        body_scope = Scope(scope.is_checked, False, condition_scope)
        node_endDoWhile = self._new_node(NodeType.ENDLOOP, do_while_statement["src"], body_scope)

        link_underlying_nodes(node, node_startDoWhile)
        # empty block, loop from the start to the condition
        if not node_condition.underlying_node.sons:
            link_underlying_nodes(node_startDoWhile, node_condition)
        else:
            link_nodes(
                node_startDoWhile.underlying_node,
                node_condition.underlying_node.sons[0],
            )
        link_underlying_nodes(statement, node_condition)
        link_underlying_nodes(node_condition, node_endDoWhile)
        return node_endDoWhile

    def _construct_try_expression(self, externalCall: Dict, parameters_list: Dict) -> Dict:
        # if the parameters are more than 1 we make the leftHandSide of the Assignment node
        # a TupleExpression otherwise an Identifier

        # case when there isn't returns(...)
        # e.g. external call that doesn't have any return variable
        if not parameters_list:
            return externalCall

        ret: Dict = {"nodeType": "Assignment", "operator": "=", "src": parameters_list["src"]}

        parameters = parameters_list.get("parameters", None)

        # if the name is "" it means the return variable is not used
        if len(parameters) == 1:
            if parameters[0]["name"] != "":
                self._add_param(parameters[0])
                ret["typeDescriptions"] = {
                    "typeString": parameters[0]["typeName"]["typeDescriptions"]["typeString"]
                }
                leftHandSide = {
                    "name": parameters[0]["name"],
                    "nodeType": "Identifier",
                    "src": parameters[0]["src"],
                    "referencedDeclaration": parameters[0]["id"],
                    "typeDescriptions": parameters[0]["typeDescriptions"],
                }
            else:
                # we don't need an Assignment so we return only the external call
                return externalCall
        else:
            ret["typeDescriptions"] = {"typeString": "tuple()"}
            leftHandSide = {
                "components": [],
                "nodeType": "TupleExpression",
                "src": parameters_list["src"],
            }

            for i, p in enumerate(parameters):
                if p["name"] == "":
                    continue

                new_statement = {
                    "nodeType": "VariableDefinitionStatement",
                    "src": p["src"],
                    "declarations": [p],
                }
                self._add_param_init_tuple(new_statement, i)

                ident = {
                    "name": p["name"],
                    "nodeType": "Identifier",
                    "src": p["src"],
                    "referencedDeclaration": p["id"],
                    "typeDescriptions": p["typeDescriptions"],
                }
                leftHandSide["components"].append(ident)

        ret["leftHandSide"] = leftHandSide
        ret["rightHandSide"] = externalCall

        return ret

    def _parse_try_catch(self, statement: Dict, node: NodeSolc, scope: Scope) -> NodeSolc:
        externalCall = statement.get("externalCall", None)

        if externalCall is None:
            raise ParsingError(f"Try/Catch not correctly parsed by Slither {statement}")
        catch_scope = Scope(scope.is_checked, False, scope)
        new_node = self._new_node(NodeType.TRY, statement["src"], catch_scope)
        clauses = statement.get("clauses", [])
        # the first clause is the try scope
        returned_variables = clauses[0].get("parameters", None)
        constructed_try_expression = self._construct_try_expression(
            externalCall, returned_variables
        )
        new_node.add_unparsed_expression(constructed_try_expression)
        link_underlying_nodes(node, new_node)
        node = new_node

        for index, clause in enumerate(clauses):
            # clauses after the first one are related to catch cases
            # we set the parameters (e.g. data in this case. catch(string memory data) ...)
            # to be initialized so they are not reported by the uninitialized-local-variables detector
            if index >= 1:
                self._parse_catch(clause, node, catch_scope, True)
            else:
                # the parameters for the try scope were already added in _construct_try_expression
                self._parse_catch(clause, node, catch_scope, False)
        return node

    def _parse_catch(
        self, statement: Dict, node: NodeSolc, scope: Scope, add_param: bool
    ) -> NodeSolc:
        block = statement.get("block", None)

        if block is None:
            raise ParsingError(f"Catch not correctly parsed by Slither {statement}")
        try_scope = Scope(scope.is_checked, False, scope)

        try_node = self._new_node(NodeType.CATCH, statement["src"], try_scope)
        link_underlying_nodes(node, try_node)

        if add_param:
            if self.is_compact_ast:
                params = statement.get("parameters", None)
            else:
                params = statement[self.get_children("children")]

            if params:
                for param in params.get("parameters", []):
                    assert param[self.get_key()] == "VariableDeclaration"
                    self._add_param(param, True)

        return self._parse_statement(block, try_node, try_scope)

    def _parse_variable_definition(self, statement: Dict, node: NodeSolc, scope: Scope) -> NodeSolc:
        try:
            local_var = LocalVariable()
            local_var.set_function(self._function)
            local_var.set_offset(statement["src"], self._function.compilation_unit)

            local_var_parser = LocalVariableSolc(local_var, statement)
            self._add_local_variable(local_var_parser)
            # local_var.analyze(self)

            new_node = self._new_node(NodeType.VARIABLE, statement["src"], scope)
            new_node.underlying_node.add_variable_declaration(local_var)
            link_underlying_nodes(node, new_node)
            return new_node
        except MultipleVariablesDeclaration:
            # Custom handling of var (a,b) = .. style declaration
            if self.is_compact_ast:
                variables = statement["declarations"]
                count = len(variables)

                if (
                    statement["initialValue"]["nodeType"] == "TupleExpression"
                    and len(statement["initialValue"]["components"]) == count
                ):
                    inits = statement["initialValue"]["components"]
                    i = 0
                    new_node = node
                    for variable in variables:
                        if variable is None:
                            continue
                        init = inits[i]
                        src = variable["src"]
                        i = i + 1

                        new_statement = {
                            "nodeType": "VariableDefinitionStatement",
                            "src": src,
                            "declarations": [variable],
                            "initialValue": init,
                        }
                        new_node = self._parse_variable_definition(new_statement, new_node, scope)

                else:
                    # If we have
                    # var (a, b) = f()
                    # we can split in multiple declarations, without init
                    # Then we craft one expression that does the assignment
                    variables = []
                    i = 0
                    new_node = node
                    for variable in statement["declarations"]:
                        if variable:
                            src = variable["src"]
                            # Create a fake statement to be consistent
                            new_statement = {
                                "nodeType": "VariableDefinitionStatement",
                                "src": src,
                                "declarations": [variable],
                            }
                            variables.append(variable)

                            new_node = self._parse_variable_definition_init_tuple(
                                new_statement, i, new_node, scope
                            )
                        else:
                            variables.append(None)
                        i = i + 1

                    var_identifiers = []
                    # craft of the expression doing the assignement
                    for v in variables:
                        if v is not None:
                            identifier = {
                                "nodeType": "Identifier",
                                "src": v["src"],
                                "name": v["name"],
                                "referencedDeclaration": v["id"],
                                "typeDescriptions": {
                                    "typeString": v["typeDescriptions"]["typeString"]
                                },
                            }
                            var_identifiers.append(identifier)
                        else:
                            var_identifiers.append(None)

                    tuple_expression = {
                        "nodeType": "TupleExpression",
                        "src": statement["src"],
                        "components": var_identifiers,
                    }

                    expression = {
                        "nodeType": "Assignment",
                        "src": statement["src"],
                        "operator": "=",
                        "type": "tuple()",
                        "leftHandSide": tuple_expression,
                        "rightHandSide": statement["initialValue"],
                        "typeDescriptions": {"typeString": "tuple()"},
                    }
                    node = new_node
                    new_node = self._new_node(NodeType.EXPRESSION, statement["src"], scope)
                    new_node.add_unparsed_expression(expression)
                    link_underlying_nodes(node, new_node)

            else:
                count = 0
                children = statement[self.get_children("children")]
                child = children[0]
                while child[self.get_key()] == "VariableDeclaration":
                    count = count + 1
                    child = children[count]

                assert len(children) == (count + 1)
                tuple_vars = children[count]

                variables_declaration = children[0:count]
                i = 0
                new_node = node
                if tuple_vars[self.get_key()] == "TupleExpression":
                    assert len(tuple_vars[self.get_children("children")]) == count
                    for variable in variables_declaration:
                        init = tuple_vars[self.get_children("children")][i]
                        src = variable["src"]
                        i = i + 1
                        # Create a fake statement to be consistent
                        new_statement = {
                            self.get_key(): "VariableDefinitionStatement",
                            "src": src,
                            self.get_children("children"): [variable, init],
                        }

                        new_node = self._parse_variable_definition(new_statement, new_node, scope)
                else:
                    # If we have
                    # var (a, b) = f()
                    # we can split in multiple declarations, without init
                    # Then we craft one expression that does the assignment
                    assert tuple_vars[self.get_key()] in ["FunctionCall", "Conditional"]
                    variables = []
                    for variable in variables_declaration:
                        src = variable["src"]
                        # Create a fake statement to be consistent
                        new_statement = {
                            self.get_key(): "VariableDefinitionStatement",
                            "src": src,
                            self.get_children("children"): [variable],
                        }
                        variables.append(variable)

                        new_node = self._parse_variable_definition_init_tuple(
                            new_statement, i, new_node, scope
                        )
                        i = i + 1
                    var_identifiers = []
                    # craft of the expression doing the assignement
                    for v in variables:
                        identifier = {
                            self.get_key(): "Identifier",
                            "src": v["src"],
                            "attributes": {
                                "value": v["attributes"][self.get_key()],
                                "type": v["attributes"]["type"],
                            },
                        }
                        var_identifiers.append(identifier)

                    expression = {
                        self.get_key(): "Assignment",
                        "src": statement["src"],
                        "attributes": {"operator": "=", "type": "tuple()"},
                        self.get_children("children"): [
                            {
                                self.get_key(): "TupleExpression",
                                "src": statement["src"],
                                self.get_children("children"): var_identifiers,
                            },
                            tuple_vars,
                        ],
                    }
                    node = new_node
                    new_node = self._new_node(NodeType.EXPRESSION, statement["src"], scope)
                    new_node.add_unparsed_expression(expression)
                    link_underlying_nodes(node, new_node)

            return new_node

    def _parse_variable_definition_init_tuple(
        self, statement: Dict, index: int, node: NodeSolc, scope
    ) -> NodeSolc:
        local_var = LocalVariableInitFromTuple()
        local_var.set_function(self._function)
        local_var.set_offset(statement["src"], self._function.compilation_unit)

        local_var_parser = LocalVariableInitFromTupleSolc(local_var, statement, index)

        self._add_local_variable(local_var_parser)

        new_node = self._new_node(NodeType.VARIABLE, statement["src"], scope)
        new_node.underlying_node.add_variable_declaration(local_var)
        link_underlying_nodes(node, new_node)
        return new_node

    def _parse_statement(
        self, statement: Dict, node: NodeSolc, scope: Union[Scope, Function]
    ) -> NodeSolc:
        """

        Return:
            node
        """
        # Statement = IfStatement | WhileStatement | ForStatement | Block | InlineAssemblyStatement |
        #            ( DoWhileStatement | PlaceholderStatement | Continue | Break | Return |
        #                          Throw | EmitStatement | SimpleStatement ) ';'
        # SimpleStatement = VariableDefinition | ExpressionStatement

        name = statement[self.get_key()]
        # SimpleStatement = VariableDefinition | ExpressionStatement
        if name == "IfStatement":
            node = self._parse_if(statement, node, scope)
        elif name == "WhileStatement":
            node = self._parse_while(statement, node, scope)
        elif name == "ForStatement":
            node = self._parse_for(statement, node, scope)
        elif name == "Block":
            node = self._parse_block(statement, node, scope)
        elif name == "UncheckedBlock":
            node = self._parse_unchecked_block(statement, node, scope)
        elif name == "InlineAssembly":
            # Added with solc 0.6 - the yul code is an AST
            if "AST" in statement and not self.compilation_unit.core.skip_assembly:
                self._function.contains_assembly = True
                yul_object = self._new_yul_block(statement["src"], scope)
                entrypoint = yul_object.entrypoint
                exitpoint = yul_object.convert(statement["AST"])

                # technically, entrypoint and exitpoint are YulNodes and we should be returning a NodeSolc here
                # but they both expose an underlying_node so oh well
                link_underlying_nodes(node, entrypoint)
                end_assembly = self._new_node(NodeType.ENDASSEMBLY, statement["src"], scope)
                link_underlying_nodes(exitpoint, end_assembly)
                node = end_assembly
            else:
                asm_node = self._new_node(NodeType.ASSEMBLY, statement["src"], scope)
                self._function.contains_assembly = True
                # Added with solc 0.4.12
                if "operations" in statement:
                    asm_node.underlying_node.add_inline_asm(statement["operations"])
                link_underlying_nodes(node, asm_node)
                end_assembly = self._new_node(NodeType.ENDASSEMBLY, statement["src"], scope)
                link_underlying_nodes(asm_node, end_assembly)
                node = end_assembly
        elif name == "DoWhileStatement":
            node = self._parse_dowhile(statement, node, scope)
        # For Continue / Break / Return / Throw
        # The is fixed later
        elif name == "Continue":
            continue_node = self._new_node(NodeType.CONTINUE, statement["src"], scope)
            link_underlying_nodes(node, continue_node)
            node = continue_node
        elif name == "Break":
            break_node = self._new_node(NodeType.BREAK, statement["src"], scope)
            link_underlying_nodes(node, break_node)
            node = break_node
        elif name == "Return":
            return_node = self._new_node(NodeType.RETURN, statement["src"], scope)
            link_underlying_nodes(node, return_node)
            if self.is_compact_ast:
                if statement.get("expression", None):
                    return_node.add_unparsed_expression(statement["expression"])
            else:
                if (
                    self.get_children("children") in statement
                    and statement[self.get_children("children")]
                ):
                    assert len(statement[self.get_children("children")]) == 1
                    expression = statement[self.get_children("children")][0]
                    return_node.add_unparsed_expression(expression)
            node = return_node
        elif name == "Throw":
            throw_node = self._new_node(NodeType.THROW, statement["src"], scope)
            link_underlying_nodes(node, throw_node)
            node = throw_node
        elif name == "EmitStatement":
            # expression = parse_expression(statement[self.get_children('children')][0], self)
            if self.is_compact_ast:
                expression = statement["eventCall"]
            else:
                expression = statement[self.get_children("children")][0]
            new_node = self._new_node(NodeType.EXPRESSION, statement["src"], scope)
            new_node.add_unparsed_expression(expression)
            link_underlying_nodes(node, new_node)
            node = new_node
        elif name in ["VariableDefinitionStatement", "VariableDeclarationStatement"]:
            node = self._parse_variable_definition(statement, node, scope)
        elif name == "ExpressionStatement":
            # assert len(statement[self.get_children('expression')]) == 1
            # assert not 'attributes' in statement
            # expression = parse_expression(statement[self.get_children('children')][0], self)
            if self.is_compact_ast:
                expression = statement[self.get_children("expression")]
            else:
                expression = statement[self.get_children("expression")][0]
            new_node = self._new_node(NodeType.EXPRESSION, statement["src"], scope)
            new_node.add_unparsed_expression(expression)
            link_underlying_nodes(node, new_node)
            node = new_node
        elif name == "TryStatement":
            node = self._parse_try_catch(statement, node, scope)
        # elif name == 'TryCatchClause':
        #     self._parse_catch(statement, node)
        elif name == "RevertStatement":
            if self.is_compact_ast:
                expression = statement[self.get_children("errorCall")]
            else:
                expression = statement[self.get_children("errorCall")][0]
            new_node = self._new_node(NodeType.EXPRESSION, statement["src"], scope)
            new_node.add_unparsed_expression(expression)
            link_underlying_nodes(node, new_node)
            node = new_node
        else:
            raise ParsingError(f"Statement not parsed {name}")

        return node

    def _parse_block(self, block: Dict, node: NodeSolc, scope: Scope) -> NodeSolc:
        """
        Return:
            Node
        """
        assert block[self.get_key()] == "Block"

        if self.is_compact_ast:
            statements = block["statements"]
        else:
            statements = block[self.get_children("children")]

        new_scope = Scope(scope.is_checked, False, scope)
        for statement in statements:
            node = self._parse_statement(statement, node, new_scope)
        return node

    def _parse_unchecked_block(self, block: Dict, node: NodeSolc, scope):
        """
        Return:
            Node
        """
        assert block[self.get_key()] == "UncheckedBlock"

        if self.is_compact_ast:
            statements = block["statements"]
        else:
            statements = block[self.get_children("children")]

        new_scope = Scope(False, False, scope)

        for statement in statements:
            node = self._parse_statement(statement, node, new_scope)
        return node

    def _update_reachability(self, node: Node) -> None:
        worklist = [node]
        while worklist:
            current = worklist.pop()
            # fix point
            if not current.is_reachable:
                current.set_is_reachable(True)
                worklist.extend(current.sons)

    def _parse_cfg(self, cfg: Dict) -> None:

        assert cfg[self.get_key()] == "Block"

        node = self._new_node(NodeType.ENTRYPOINT, cfg["src"], self.underlying_function)
        self._function.entry_point = node.underlying_node

        if self.is_compact_ast:
            statements = cfg["statements"]
        else:
            statements = cfg[self.get_children("children")]

        if not statements:
            self._function.is_empty = True
        else:
            self._function.is_empty = False
            self._parse_block(cfg, node, self.underlying_function)
            self._remove_incorrect_edges()
            self._remove_alone_endif()

    # endregion
    ###################################################################################
    ###################################################################################
    # region Loops
    ###################################################################################
    ###################################################################################

    def _find_end_loop(self, node: Node, visited: List[Node], counter: int) -> Optional[Node]:
        # counter allows to explore nested loop
        if node in visited:
            return None

        if node.type == NodeType.ENDLOOP:
            if counter == 0:
                return node
            counter -= 1

        # nested loop
        if node.type == NodeType.STARTLOOP:
            counter += 1

        visited = visited + [node]
        for son in node.sons:
            ret = self._find_end_loop(son, visited, counter)
            if ret:
                return ret

        return None

    def _find_if_loop(self, node: Node, visited: List[Node], skip_if_loop: int) -> Optional[Node]:
        if node in visited:
            return None

        # If skip_if_loop is not 0 it means we are in a nested situation
        # and we have to skip the closer n loop headers.
        # If in the fathers there is an EXPRESSION node it's a for loop
        # and it's the index increment expression
        if node.type == NodeType.IFLOOP:
            if skip_if_loop == 0:
                for father in node.fathers:
                    if father.type == NodeType.EXPRESSION:
                        return father
                return node

        # skip_if_loop works as explained above.
        # This handle when a for loop doesn't have a condition
        # e.g. for (;;) {}
        # and decrement skip_if_loop since we are out of the nested loop
        if node.type == NodeType.STARTLOOP:
            if skip_if_loop == 0:
                return node
            skip_if_loop -= 1

        # If we find an ENDLOOP means we are in a nested loop
        # we increment skip_if_loop counter
        if node.type == NodeType.ENDLOOP:
            skip_if_loop += 1

        visited = visited + [node]
        for father in node.fathers:
            ret = self._find_if_loop(father, visited, skip_if_loop)
            if ret:
                return ret

        return None

    def _fix_break_node(self, node: Node) -> None:
        end_node = self._find_end_loop(node, [], 0)

        if not end_node:
            # If there is not end condition on the loop
            # The exploration will reach a STARTLOOP before reaching the endloop
            # We start with -1 as counter to catch this corner case
            end_node = self._find_end_loop(node, [], -1)
            if not end_node:
                raise ParsingError(f"Break in no-loop context {node.function}")

        for son in node.sons:
            son.remove_father(node)
        node.set_sons([end_node])
        end_node.add_father(node)

    def _fix_continue_node(self, node: Node) -> None:
        if_loop_node = self._find_if_loop(node, [], 0)

        if not if_loop_node:
            raise ParsingError(f"Continue in no-loop context {node.node_id}")

        for son in node.sons:
            son.remove_father(node)
        node.set_sons([if_loop_node])
        if_loop_node.add_father(node)

    # endregion
    ###################################################################################
    ###################################################################################
    # region Try-Catch
    ###################################################################################
    ###################################################################################

    def _fix_try(self, node: Node) -> None:
        end_node = next((son for son in node.sons if son.type != NodeType.CATCH), None)
        if end_node:
            for son in node.sons:
                if son.type == NodeType.CATCH:
                    self._fix_catch(son, end_node, set())

    def _fix_catch(self, node: Node, end_node: Node, visited: Set[Node]) -> None:
        if not node.sons:
            link_nodes(node, end_node)
        else:
            for son in node.sons:
                if son != end_node and son not in visited:
                    visited.add(son)
                    self._fix_catch(son, end_node, visited)

    # endregion
    ###################################################################################
    ###################################################################################
    # region Params, Returns, Modifiers
    ###################################################################################
    ###################################################################################

    def _add_param(self, param: Dict, initialized: bool = False) -> LocalVariableSolc:

        local_var = LocalVariable()
        local_var.set_function(self._function)
        local_var.set_offset(param["src"], self._function.compilation_unit)

        local_var_parser = LocalVariableSolc(local_var, param)

        local_var_parser.analyze(self)

        if initialized:
            local_var.initialized = True

        # see https://solidity.readthedocs.io/en/v0.4.24/types.html?highlight=storage%20location#data-location
        if local_var.location == "default":
            local_var.set_location("memory")

        self._add_local_variable(local_var_parser)
        return local_var_parser

    def _add_param_init_tuple(self, statement: Dict, index: int) -> LocalVariableInitFromTupleSolc:

        local_var = LocalVariableInitFromTuple()
        local_var.set_function(self._function)
        local_var.set_offset(statement["src"], self._function.compilation_unit)

        local_var_parser = LocalVariableInitFromTupleSolc(local_var, statement, index)

        self._add_local_variable(local_var_parser)
        return local_var_parser

    def _parse_params(self, params: Dict):
        assert params[self.get_key()] == "ParameterList"

        self._function.parameters_src().set_offset(params["src"], self._function.compilation_unit)

        if self.is_compact_ast:
            params = params["parameters"]
        else:
            params = params[self.get_children("children")]

        for param in params:
            assert param[self.get_key()] == "VariableDeclaration"
            local_var = self._add_param(param)
            self._function.add_parameters(local_var.underlying_variable)

    def _parse_returns(self, returns: Dict):

        assert returns[self.get_key()] == "ParameterList"

        self._function.returns_src().set_offset(returns["src"], self._function.compilation_unit)

        if self.is_compact_ast:
            self._returnsNotParsed = returns["parameters"]
        else:
            self._returnsNotParsed = returns[self.get_children("children")]

        for ret in self._returnsNotParsed:
            assert ret[self.get_key()] == "VariableDeclaration"
            local_var = self._add_param(ret)
            self._function.add_return(local_var.underlying_variable)

    def _parse_modifier(self, modifier: Dict):
        m = parse_expression(modifier, self)
        # self._expression_modifiers.append(m)

        # Do not parse modifier nodes for interfaces
        if not self._function.is_implemented:
            return

        for m in ExportValues(m).result():
            if isinstance(m, Function):
                node_parser = self._new_node(
                    NodeType.EXPRESSION, modifier["src"], self.underlying_function
                )
                node_parser.add_unparsed_expression(modifier)
                # The latest entry point is the entry point, or the latest modifier call
                if self._function.modifiers:
                    latest_entry_point = self._function.modifiers_statements[-1].nodes[-1]
                else:
                    latest_entry_point = self._function.entry_point
                insert_node(latest_entry_point, node_parser.underlying_node)
                self._function.add_modifier(
                    ModifierStatements(
                        modifier=m,
                        entry_point=latest_entry_point,
                        nodes=[latest_entry_point, node_parser.underlying_node],
                    )
                )

            elif isinstance(m, Contract):
                node_parser = self._new_node(
                    NodeType.EXPRESSION, modifier["src"], self.underlying_function
                )
                node_parser.add_unparsed_expression(modifier)
                # The latest entry point is the entry point, or the latest constructor call
                if self._function.explicit_base_constructor_calls_statements:
                    latest_entry_point = self._function.explicit_base_constructor_calls_statements[
                        -1
                    ].nodes[-1]
                else:
                    latest_entry_point = self._function.entry_point
                insert_node(latest_entry_point, node_parser.underlying_node)
                self._function.add_explicit_base_constructor_calls_statements(
                    ModifierStatements(
                        modifier=m,
                        entry_point=latest_entry_point,
                        nodes=[latest_entry_point, node_parser.underlying_node],
                    )
                )

    def _fix_implicit_return(self, return_params: Dict) -> None:
        """
        Creates an artificial return node iff a function has a named return variable declared in its signature.
        Finds all leaf nodes in the CFG which are not return nodes, and links them to the artificial return node.
        """
        does_not_have_return_params = len(self.underlying_function.returns) == 0
        does_not_have_named_returns = all(
            ret.name == "" for ret in self.underlying_function.returns
        )
        not_implemented = not self._function.is_implemented

        if does_not_have_return_params or does_not_have_named_returns or not_implemented:
            return

        return_node = self._new_node(
            NodeType.RETURN, return_params["src"], self.underlying_function
        )
        for node, node_solc in self._node_to_nodesolc.items():
            if len(node.sons) == 0 and node.type not in [NodeType.RETURN, NodeType.THROW]:
                link_underlying_nodes(node_solc, return_node)

        for _, yul_block in self._node_to_yulobject.items():
            for yul_node in yul_block.nodes:
                node = yul_node.underlying_node
                if len(node.sons) == 0 and node.type not in [NodeType.RETURN, NodeType.THROW]:
                    link_underlying_nodes(yul_node, return_node)

        if self.is_compact_ast:
            self._add_return_exp_compact(return_node, return_params)
        else:
            self._add_return_exp_legacy(return_node, return_params)

        return_node.analyze_expressions(self)

    def _add_return_exp_compact(self, return_node: NodeSolc, return_params: Dict) -> None:
        if len(self.underlying_function.returns) == 1:
            return_arg = self.underlying_function.returns[0]
            if return_arg.name != "":
                (refId, refSrc, refType) = next(
                    (ret["id"], ret["src"], ret["typeDescriptions"])
                    for ret in self._returnsNotParsed
                    if ret["name"] == return_arg.name
                )
                return_node.add_unparsed_expression(
                    {
                        "name": return_arg.name,
                        "nodeType": "Identifier",
                        "overloadedDeclarations": [],
                        "referencedDeclaration": refId,
                        "src": refSrc,
                        "typeDescriptions": refType,
                    }
                )
        else:
            expression = {
                "components": [],
                "isConstant": False,
                "isInlineArray": False,
                "isLValue": False,
                "isPure": False,
                "lValueRequested": False,
                "nodeType": "TupleExpression",
                "src": return_params["src"],
                "typeDescriptions": {},
            }
            type_ids = []
            type_strs = []
            for return_arg in self.underlying_function.returns:
                # For each named return variable, we add an identifier to the tuple.
                if return_arg.name != "":
                    (refId, refSrc, refType) = next(
                        (ret["id"], ret["src"], ret["typeDescriptions"])
                        for ret in self._returnsNotParsed
                        if ret["name"] == return_arg.name
                    )
                    type_ids.append(refType["typeIdentifier"])
                    type_strs.append(refType["typeString"])
                    expression["components"].append(
                        {
                            "name": return_arg.name,
                            "nodeType": "Identifier",
                            "overloadedDeclarations": [],
                            "referencedDeclaration": refId,
                            "src": refSrc,
                            "typeDescriptions": refType,
                        }
                    )
            expression["typeDescriptions"]["typeIdentifier"] = (
                "t_tuple$_" + "_$_".join(type_ids) + "_$"
            )
            expression["typeDescriptions"]["typeString"] = "tuple(" + ",".join(type_strs) + ")"
            return_node.add_unparsed_expression(expression)

    def _add_return_exp_legacy(self, return_node: NodeSolc, return_params: Dict) -> None:
        if len(self.underlying_function.returns) == 1:
            return_arg = self.underlying_function.returns[0]
            if return_arg.name != "":
                (refSrc, refType) = next(
                    (ret["src"], ret["attributes"]["type"])
                    for ret in self._returnsNotParsed
                    if ret["attributes"]["name"] == return_arg.name
                )
                return_node.add_unparsed_expression(
                    {
                        "attributes": {"type": refType, "value": return_arg.name},
                        "name": "Identifier",
                        "src": refSrc,
                    }
                )
        else:
            expression = {
                "children": [],
                "name": "TupleExpression",
                "src": return_params["src"],
            }
            for return_arg in self.underlying_function.returns:
                # For each named return variable, we add an identifier to the tuple.
                if return_arg.name != "":
                    (refSrc, refType) = next(
                        (ret["src"], ret["attributes"]["type"])
                        for ret in self._returnsNotParsed
                        if ret["attributes"]["name"] == return_arg.name
                    )
                    expression["children"].append(
                        {
                            "attributes": {"type": refType, "value": return_arg.name},
                            "name": "Identifier",
                            "src": refSrc,
                        }
                    )
            return_node.add_unparsed_expression(expression)

    # endregion
    ###################################################################################
    ###################################################################################
    # region Edges
    ###################################################################################
    ###################################################################################

    def _remove_incorrect_edges(self):
        for node in self._node_to_nodesolc:
            if node.type in [NodeType.RETURN, NodeType.THROW]:
                for son in node.sons:
                    son.remove_father(node)
                node.set_sons([])
            if node.type in [NodeType.BREAK]:
                self._fix_break_node(node)
            if node.type in [NodeType.CONTINUE]:
                self._fix_continue_node(node)
            if node.type in [NodeType.TRY]:
                self._fix_try(node)

        # this step needs to happen after all of the break statements are fixed
        # really, we should be passing some sort of context down so the break statement doesn't
        # need to be fixed out-of-band in the first place
        for node in self._node_to_nodesolc:
            if node.type in [NodeType.STARTLOOP]:
                # can we prune? only if after pruning, we have at least one son that isn't itself
                if (
                    len([son for son in node.sons if son.type != NodeType.ENDLOOP and son != node])
                    == 0
                ):
                    continue

                new_sons = []
                for son in node.sons:
                    if son.type != NodeType.ENDLOOP:
                        new_sons.append(son)
                        continue
                    son.remove_father(node)
                node.set_sons(new_sons)

    def _remove_alone_endif(self) -> None:
        """
        Can occur on:
        if(..){
            return
        }
        else{
            return
        }

        Iterate until a fix point to remove the ENDIF node
        creates on the following pattern
        if(){
            return
        }
        else if(){
            return
        }
        """
        prev_nodes = []
        while set(prev_nodes) != set(self._node_to_nodesolc.keys()):
            prev_nodes = self._node_to_nodesolc.keys()
            to_remove: List[Node] = []
            for node in self._node_to_nodesolc:
                if node.type == NodeType.ENDIF and not node.fathers:
                    for son in node.sons:
                        son.remove_father(node)
                    node.set_sons([])
                    to_remove.append(node)
            self._function.nodes = [n for n in self._function.nodes if n not in to_remove]
            for remove in to_remove:
                if remove in self._node_to_nodesolc:
                    del self._node_to_nodesolc[remove]

    # endregion
    ###################################################################################
    ###################################################################################
    # region Ternary
    ###################################################################################
    ###################################################################################

    def _rewrite_ternary_as_if_else(self) -> bool:
        ternary_found = True
        updated = False
        while ternary_found:
            ternary_found = False
            for node in self._node_to_nodesolc:
                has_cond = HasConditional(node.expression)
                if has_cond.result():
                    st = SplitTernaryExpression(node.expression)
                    condition = st.condition
                    if not condition:
                        raise ParsingError(
                            f"Incorrect ternary conversion {node.expression} {node.source_mapping}"
                        )
                    true_expr = st.true_expression
                    false_expr = st.false_expression
                    self._split_ternary_node(node, condition, true_expr, false_expr)
                    ternary_found = True
                    updated = True
                    break
        return updated

    def _split_ternary_node(
        self,
        node: Node,
        condition: "Expression",
        true_expr: "Expression",
        false_expr: "Expression",
    ):
        condition_node = self._new_node(NodeType.IF, node.source_mapping, node.scope)
        condition_node.underlying_node.add_expression(condition)
        condition_node.analyze_expressions(self)

        if node.type == NodeType.VARIABLE:
            condition_node.underlying_node.add_variable_declaration(node.variable_declaration)

        true_node_parser = self._new_node(NodeType.EXPRESSION, node.source_mapping, node.scope)
        if node.type == NodeType.VARIABLE:
            assert isinstance(true_expr, AssignmentOperation)
            # true_expr = true_expr.expression_right
        elif node.type == NodeType.RETURN:
            true_node_parser.underlying_node.type = NodeType.RETURN
        true_node_parser.underlying_node.add_expression(true_expr)
        true_node_parser.analyze_expressions(self)

        false_node_parser = self._new_node(NodeType.EXPRESSION, node.source_mapping, node.scope)
        if node.type == NodeType.VARIABLE:
            assert isinstance(false_expr, AssignmentOperation)
        elif node.type == NodeType.RETURN:
            false_node_parser.underlying_node.type = NodeType.RETURN
            # false_expr = false_expr.expression_right
        false_node_parser.underlying_node.add_expression(false_expr)
        false_node_parser.analyze_expressions(self)

        endif_node = self._new_node(NodeType.ENDIF, node.source_mapping, node.scope)

        for father in node.fathers:
            father.replace_son(node, condition_node.underlying_node)
            condition_node.underlying_node.add_father(father)

        for son in node.sons:
            son.remove_father(node)
            son.add_father(endif_node.underlying_node)
            endif_node.underlying_node.add_son(son)

        link_underlying_nodes(condition_node, true_node_parser)
        link_underlying_nodes(condition_node, false_node_parser)

        if true_node_parser.underlying_node.type not in [
            NodeType.THROW,
            NodeType.RETURN,
        ]:
            link_underlying_nodes(true_node_parser, endif_node)
        if false_node_parser.underlying_node.type not in [
            NodeType.THROW,
            NodeType.RETURN,
        ]:
            link_underlying_nodes(false_node_parser, endif_node)

        self._function.nodes = [n for n in self._function.nodes if n.node_id != node.node_id]
        del self._node_to_nodesolc[node]

    # endregion