/* This file is part of cpp-ethereum. cpp-ethereum is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. cpp-ethereum is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with cpp-ethereum. If not, see . */ /** * @author Christian * @date 2014 * Solidity abstract syntax tree. */ #pragma once #include #include #include #include #include #include #include #include #include namespace dev { namespace solidity { class ASTVisitor; /** * The root (abstract) class of the AST inheritance tree. * It is possible to traverse all direct and indirect children of an AST node by calling * accept, providing an ASTVisitor. */ class ASTNode: private boost::noncopyable { public: explicit ASTNode(Location const& _location): m_location(_location) {} virtual ~ASTNode() {} virtual void accept(ASTVisitor& _visitor) = 0; template static void listAccept(std::vector>& _list, ASTVisitor& _visitor) { for (ASTPointer& element: _list) element->accept(_visitor); } /// Returns the source code location of this node. Location const& getLocation() const { return m_location; } /// Creates a @ref TypeError exception and decorates it with the location of the node and /// the given description TypeError createTypeError(std::string const& _description); ///@{ ///@name equality operators /// Equality relies on the fact that nodes cannot be copied. bool operator==(ASTNode const& _other) const { return this == &_other; } bool operator!=(ASTNode const& _other) const { return !operator==(_other); } ///@} private: Location m_location; }; /** * Abstract AST class for a declaration (contract, function, struct, variable). */ class Declaration: public ASTNode { public: Declaration(Location const& _location, ASTPointer const& _name): ASTNode(_location), m_name(_name) {} /// Returns the declared name. ASTString const& getName() const { return *m_name; } private: ASTPointer m_name; }; /** * Definition of a contract. This is the only AST nodes where child nodes are not visited in * document order. It first visits all struct declarations, then all variable declarations and * finally all function declarations. */ class ContractDefinition: public Declaration { public: ContractDefinition(Location const& _location, ASTPointer const& _name, std::vector> const& _definedStructs, std::vector> const& _stateVariables, std::vector> const& _definedFunctions): Declaration(_location, _name), m_definedStructs(_definedStructs), m_stateVariables(_stateVariables), m_definedFunctions(_definedFunctions) {} virtual void accept(ASTVisitor& _visitor) override; std::vector> const& getDefinedStructs() const { return m_definedStructs; } std::vector> const& getStateVariables() const { return m_stateVariables; } std::vector> const& getDefinedFunctions() const { return m_definedFunctions; } /// Returns the functions that make up the calling interface in the intended order. std::vector getInterfaceFunctions() const; private: std::vector> m_definedStructs; std::vector> m_stateVariables; std::vector> m_definedFunctions; }; class StructDefinition: public Declaration { public: StructDefinition(Location const& _location, ASTPointer const& _name, std::vector> const& _members): Declaration(_location, _name), m_members(_members) {} virtual void accept(ASTVisitor& _visitor) override; std::vector> const& getMembers() const { return m_members; } private: std::vector> m_members; }; /** * Parameter list, used as function parameter list and return list. * None of the parameters is allowed to contain mappings (not even recursively * inside structs), but (@todo) this is not yet enforced. */ class ParameterList: public ASTNode { public: ParameterList(Location const& _location, std::vector> const& _parameters): ASTNode(_location), m_parameters(_parameters) {} virtual void accept(ASTVisitor& _visitor) override; std::vector> const& getParameters() const { return m_parameters; } private: std::vector> m_parameters; }; class FunctionDefinition: public Declaration { public: FunctionDefinition(Location const& _location, ASTPointer const& _name, bool _isPublic, ASTPointer const& _parameters, bool _isDeclaredConst, ASTPointer const& _returnParameters, ASTPointer const& _body): Declaration(_location, _name), m_isPublic(_isPublic), m_parameters(_parameters), m_isDeclaredConst(_isDeclaredConst), m_returnParameters(_returnParameters), m_body(_body) {} virtual void accept(ASTVisitor& _visitor) override; bool isPublic() const { return m_isPublic; } bool isDeclaredConst() const { return m_isDeclaredConst; } std::vector> const& getParameters() const { return m_parameters->getParameters(); } ParameterList& getParameterList() { return *m_parameters; } std::vector> const& getReturnParameters() const { return m_returnParameters->getParameters(); } ASTPointer const& getReturnParameterList() const { return m_returnParameters; } Block& getBody() { return *m_body; } void addLocalVariable(VariableDeclaration const& _localVariable) { m_localVariables.push_back(&_localVariable); } std::vector const& getLocalVariables() const { return m_localVariables; } /// Checks that all parameters have allowed types and calls checkTypeRequirements on the body. void checkTypeRequirements(); private: bool m_isPublic; ASTPointer m_parameters; bool m_isDeclaredConst; ASTPointer m_returnParameters; ASTPointer m_body; std::vector m_localVariables; }; /** * Declaration of a variable. This can be used in various places, e.g. in function parameter * lists, struct definitions and even function bodys. */ class VariableDeclaration: public Declaration { public: VariableDeclaration(Location const& _location, ASTPointer const& _type, ASTPointer const& _name): Declaration(_location, _name), m_typeName(_type) {} virtual void accept(ASTVisitor& _visitor) override; bool isTypeGivenExplicitly() const { return bool(m_typeName); } TypeName* getTypeName() const { return m_typeName.get(); } /// Returns the declared or inferred type. Can be an empty pointer if no type was explicitly /// declared and there is no assignment to the variable that fixes the type. std::shared_ptr const& getType() const { return m_type; } void setType(std::shared_ptr const& _type) { m_type = _type; } private: ASTPointer m_typeName; ///< can be empty ("var") std::shared_ptr m_type; ///< derived type, initially empty }; /// Types /// @{ /** * Abstract base class of a type name, can be any built-in or user-defined type. */ class TypeName: public ASTNode { public: explicit TypeName(Location const& _location): ASTNode(_location) {} virtual void accept(ASTVisitor& _visitor) override; /// Retrieve the element of the type hierarchy this node refers to. Can return an empty shared /// pointer until the types have been resolved using the @ref NameAndTypeResolver. virtual std::shared_ptr toType() const = 0; }; /** * Any pre-defined type name represented by a single keyword, i.e. it excludes mappings, * contracts, functions, etc. */ class ElementaryTypeName: public TypeName { public: explicit ElementaryTypeName(Location const& _location, Token::Value _type): TypeName(_location), m_type(_type) { if (asserts(Token::isElementaryTypeName(_type))) BOOST_THROW_EXCEPTION(InternalCompilerError()); } virtual void accept(ASTVisitor& _visitor) override; virtual std::shared_ptr toType() const override { return Type::fromElementaryTypeName(m_type); } Token::Value getTypeName() const { return m_type; } private: Token::Value m_type; }; /** * Name referring to a user-defined type (i.e. a struct). * @todo some changes are necessary if this is also used to refer to contract types later */ class UserDefinedTypeName: public TypeName { public: UserDefinedTypeName(Location const& _location, ASTPointer const& _name): TypeName(_location), m_name(_name) {} virtual void accept(ASTVisitor& _visitor) override; virtual std::shared_ptr toType() const override { return Type::fromUserDefinedTypeName(*this); } ASTString const& getName() const { return *m_name; } void setReferencedStruct(StructDefinition& _referencedStruct) { m_referencedStruct = &_referencedStruct; } StructDefinition const* getReferencedStruct() const { return m_referencedStruct; } private: ASTPointer m_name; StructDefinition* m_referencedStruct; }; /** * A mapping type. Its source form is "mapping('keyType' => 'valueType')" */ class Mapping: public TypeName { public: Mapping(Location const& _location, ASTPointer const& _keyType, ASTPointer const& _valueType): TypeName(_location), m_keyType(_keyType), m_valueType(_valueType) {} virtual void accept(ASTVisitor& _visitor) override; virtual std::shared_ptr toType() const override { return Type::fromMapping(*this); } ElementaryTypeName const& getKeyType() const { return *m_keyType; } TypeName const& getValueType() const { return *m_valueType; } private: ASTPointer m_keyType; ASTPointer m_valueType; }; /// @} /// Statements /// @{ /** * Abstract base class for statements. */ class Statement: public ASTNode { public: explicit Statement(Location const& _location): ASTNode(_location) {} virtual void accept(ASTVisitor& _visitor) override; /// Check all type requirements, throws exception if some requirement is not met. /// This includes checking that operators are applicable to their arguments but also that /// the number of function call arguments matches the number of formal parameters and so forth. virtual void checkTypeRequirements() = 0; }; /** * Brace-enclosed block containing zero or more statements. */ class Block: public Statement { public: Block(Location const& _location, std::vector> const& _statements): Statement(_location), m_statements(_statements) {} virtual void accept(ASTVisitor& _visitor) override; virtual void checkTypeRequirements() override; private: std::vector> m_statements; }; /** * If-statement with an optional "else" part. Note that "else if" is modeled by having a new * if-statement as the false (else) body. */ class IfStatement: public Statement { public: IfStatement(Location const& _location, ASTPointer const& _condition, ASTPointer const& _trueBody, ASTPointer const& _falseBody): Statement(_location), m_condition(_condition), m_trueBody(_trueBody), m_falseBody(_falseBody) {} virtual void accept(ASTVisitor& _visitor) override; virtual void checkTypeRequirements() override; Expression& getCondition() const { return *m_condition; } Statement& getTrueStatement() const { return *m_trueBody; } /// @returns the "else" part of the if statement or nullptr if there is no "else" part. Statement* getFalseStatement() const { return m_falseBody.get(); } private: ASTPointer m_condition; ASTPointer m_trueBody; ASTPointer m_falseBody; ///< "else" part, optional }; /** * Statement in which a break statement is legal. * @todo actually check this requirement. */ class BreakableStatement: public Statement { public: BreakableStatement(Location const& _location): Statement(_location) {} virtual void accept(ASTVisitor& _visitor) override; }; class WhileStatement: public BreakableStatement { public: WhileStatement(Location const& _location, ASTPointer const& _condition, ASTPointer const& _body): BreakableStatement(_location), m_condition(_condition), m_body(_body) {} virtual void accept(ASTVisitor& _visitor) override; virtual void checkTypeRequirements() override; Expression& getCondition() const { return *m_condition; } Statement& getBody() const { return *m_body; } private: ASTPointer m_condition; ASTPointer m_body; }; class Continue: public Statement { public: Continue(Location const& _location): Statement(_location) {} virtual void accept(ASTVisitor& _visitor) override; virtual void checkTypeRequirements() override {} }; class Break: public Statement { public: Break(Location const& _location): Statement(_location) {} virtual void accept(ASTVisitor& _visitor) override; virtual void checkTypeRequirements() override {} }; class Return: public Statement { public: Return(Location const& _location, ASTPointer _expression): Statement(_location), m_expression(_expression) {} virtual void accept(ASTVisitor& _visitor) override; virtual void checkTypeRequirements() override; void setFunctionReturnParameters(ParameterList& _parameters) { m_returnParameters = &_parameters; } ParameterList const& getFunctionReturnParameters() const { if (asserts(m_returnParameters)) BOOST_THROW_EXCEPTION(InternalCompilerError()); return *m_returnParameters; } Expression* getExpression() const { return m_expression.get(); } private: ASTPointer m_expression; ///< value to return, optional /// Pointer to the parameter list of the function, filled by the @ref NameAndTypeResolver. ParameterList* m_returnParameters; }; /** * Definition of a variable as a statement inside a function. It requires a type name (which can * also be "var") but the actual assignment can be missing. * Examples: var a = 2; uint256 a; */ class VariableDefinition: public Statement { public: VariableDefinition(Location const& _location, ASTPointer _variable, ASTPointer _value): Statement(_location), m_variable(_variable), m_value(_value) {} virtual void accept(ASTVisitor& _visitor) override; virtual void checkTypeRequirements() override; VariableDeclaration const& getDeclaration() const { return *m_variable; } Expression* getExpression() const { return m_value.get(); } private: ASTPointer m_variable; ASTPointer m_value; ///< the assigned value, can be missing }; /** * A statement that contains only an expression (i.e. an assignment, function call, ...). */ class ExpressionStatement: public Statement { public: ExpressionStatement(Location const& _location, ASTPointer _expression): Statement(_location), m_expression(_expression) {} virtual void accept(ASTVisitor& _visitor) override; virtual void checkTypeRequirements() override; Expression& getExpression() const { return *m_expression; } private: ASTPointer m_expression; }; /// @} /// Expressions /// @{ /** * An expression, i.e. something that has a value (which can also be of type "void" in case * of some function calls). * @abstract */ class Expression: public ASTNode { public: Expression(Location const& _location): ASTNode(_location), m_isLvalue(false), m_lvalueRequested(false) {} virtual void checkTypeRequirements() = 0; std::shared_ptr const& getType() const { return m_type; } bool isLvalue() const { return m_isLvalue; } /// Helper function, infer the type via @ref checkTypeRequirements and then check that it /// is implicitly convertible to @a _expectedType. If not, throw exception. void expectType(Type const& _expectedType); /// Checks that this expression is an lvalue and also registers that an address and /// not a value is generated during compilation. Can be called after checkTypeRequirements() /// by an enclosing expression. void requireLValue(); /// Returns true if @a requireLValue was previously called on this expression. bool lvalueRequested() const { return m_lvalueRequested; } protected: //! Inferred type of the expression, only filled after a call to checkTypeRequirements(). std::shared_ptr m_type; //! Whether or not this expression is an lvalue, i.e. something that can be assigned to. //! This is set during calls to @a checkTypeRequirements() bool m_isLvalue; //! Whether the outer expression requested the address (true) or the value (false) of this expression. bool m_lvalueRequested; }; /// Assignment, can also be a compound assignment. /// Examples: (a = 7 + 8) or (a *= 2) class Assignment: public Expression { public: Assignment(Location const& _location, ASTPointer const& _leftHandSide, Token::Value _assignmentOperator, ASTPointer const& _rightHandSide): Expression(_location), m_leftHandSide(_leftHandSide), m_assigmentOperator(_assignmentOperator), m_rightHandSide(_rightHandSide) { if (asserts(Token::isAssignmentOp(_assignmentOperator))) BOOST_THROW_EXCEPTION(InternalCompilerError()); } virtual void accept(ASTVisitor& _visitor) override; virtual void checkTypeRequirements() override; Expression& getLeftHandSide() const { return *m_leftHandSide; } Token::Value getAssignmentOperator() const { return m_assigmentOperator; } Expression& getRightHandSide() const { return *m_rightHandSide; } private: ASTPointer m_leftHandSide; Token::Value m_assigmentOperator; ASTPointer m_rightHandSide; }; /** * Operation involving a unary operator, pre- or postfix. * Examples: ++i, delete x or !true */ class UnaryOperation: public Expression { public: UnaryOperation(Location const& _location, Token::Value _operator, ASTPointer const& _subExpression, bool _isPrefix): Expression(_location), m_operator(_operator), m_subExpression(_subExpression), m_isPrefix(_isPrefix) { if (asserts(Token::isUnaryOp(_operator))) BOOST_THROW_EXCEPTION(InternalCompilerError()); } virtual void accept(ASTVisitor& _visitor) override; virtual void checkTypeRequirements() override; Token::Value getOperator() const { return m_operator; } bool isPrefixOperation() const { return m_isPrefix; } Expression& getSubExpression() const { return *m_subExpression; } private: Token::Value m_operator; ASTPointer m_subExpression; bool m_isPrefix; }; /** * Operation involving a binary operator. * Examples: 1 + 2, true && false or 1 <= 4 */ class BinaryOperation: public Expression { public: BinaryOperation(Location const& _location, ASTPointer const& _left, Token::Value _operator, ASTPointer const& _right): Expression(_location), m_left(_left), m_operator(_operator), m_right(_right) { if (asserts(Token::isBinaryOp(_operator) || Token::isCompareOp(_operator))) BOOST_THROW_EXCEPTION(InternalCompilerError()); } virtual void accept(ASTVisitor& _visitor) override; virtual void checkTypeRequirements() override; Expression& getLeftExpression() const { return *m_left; } Expression& getRightExpression() const { return *m_right; } Token::Value getOperator() const { return m_operator; } Type const& getCommonType() const { return *m_commonType; } private: ASTPointer m_left; Token::Value m_operator; ASTPointer m_right; /// The common type that is used for the operation, not necessarily the result type (e.g. for /// comparisons, this is always bool). std::shared_ptr m_commonType; }; /** * Can be ordinary function call, type cast or struct construction. */ class FunctionCall: public Expression { public: FunctionCall(Location const& _location, ASTPointer const& _expression, std::vector> const& _arguments): Expression(_location), m_expression(_expression), m_arguments(_arguments) {} virtual void accept(ASTVisitor& _visitor) override; virtual void checkTypeRequirements() override; Expression& getExpression() const { return *m_expression; } std::vector> const& getArguments() const { return m_arguments; } /// Returns true if this is not an actual function call, but an explicit type conversion /// or constructor call. bool isTypeConversion() const; private: ASTPointer m_expression; std::vector> m_arguments; }; /** * Access to a member of an object. Example: x.name */ class MemberAccess: public Expression { public: MemberAccess(Location const& _location, ASTPointer _expression, ASTPointer const& _memberName): Expression(_location), m_expression(_expression), m_memberName(_memberName) {} virtual void accept(ASTVisitor& _visitor) override; ASTString const& getMemberName() const { return *m_memberName; } virtual void checkTypeRequirements() override; private: ASTPointer m_expression; ASTPointer m_memberName; }; /** * Index access to an array. Example: a[2] */ class IndexAccess: public Expression { public: IndexAccess(Location const& _location, ASTPointer const& _base, ASTPointer const& _index): Expression(_location), m_base(_base), m_index(_index) {} virtual void accept(ASTVisitor& _visitor) override; virtual void checkTypeRequirements() override; Expression& getBaseExpression() const { return *m_base; } Expression& getIndexExpression() const { return *m_index; } private: ASTPointer m_base; ASTPointer m_index; }; /** * Primary expression, i.e. an expression that cannot be divided any further. Examples are literals * or variable references. */ class PrimaryExpression: public Expression { public: PrimaryExpression(Location const& _location): Expression(_location) {} }; /** * An identifier, i.e. a reference to a declaration by name like a variable or function. */ class Identifier: public PrimaryExpression { public: Identifier(Location const& _location, ASTPointer const& _name): PrimaryExpression(_location), m_name(_name) {} virtual void accept(ASTVisitor& _visitor) override; virtual void checkTypeRequirements() override; ASTString const& getName() const { return *m_name; } void setReferencedDeclaration(Declaration& _referencedDeclaration) { m_referencedDeclaration = &_referencedDeclaration; } Declaration* getReferencedDeclaration() { return m_referencedDeclaration; } private: ASTPointer m_name; /// Declaration the name refers to. Declaration* m_referencedDeclaration; }; /** * An elementary type name expression is used in expressions like "a = uint32(2)" to change the * type of an expression explicitly. Here, "uint32" is the elementary type name expression and * "uint32(2)" is a @ref FunctionCall. */ class ElementaryTypeNameExpression: public PrimaryExpression { public: ElementaryTypeNameExpression(Location const& _location, Token::Value _typeToken): PrimaryExpression(_location), m_typeToken(_typeToken) { if (asserts(Token::isElementaryTypeName(_typeToken))) BOOST_THROW_EXCEPTION(InternalCompilerError()); } virtual void accept(ASTVisitor& _visitor) override; virtual void checkTypeRequirements() override; Token::Value getTypeToken() const { return m_typeToken; } private: Token::Value m_typeToken; }; /** * A literal string or number. @see Type::literalToBigEndian is used to actually parse its value. */ class Literal: public PrimaryExpression { public: Literal(Location const& _location, Token::Value _token, ASTPointer const& _value): PrimaryExpression(_location), m_token(_token), m_value(_value) {} virtual void accept(ASTVisitor& _visitor) override; virtual void checkTypeRequirements() override; Token::Value getToken() const { return m_token; } /// @returns the non-parsed value of the literal ASTString const& getValue() const { return *m_value; } private: Token::Value m_token; ASTPointer m_value; }; /// @} } }