path: root/Parser.h

/*
    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 <http://www.gnu.org/licenses/>.
*/
/**
 * @author Christian <c@ethdev.com>
 * @date 2014
 * Solidity parser.
 */

#pragma once

#include "libsolidity/AST.h"

namespace dev
{
namespace solidity
{

class Scanner;

class Parser
{
public:
    Parser() {}

    ASTPointer<SourceUnit> parse(std::shared_ptr<Scanner> const& _scanner);
    std::shared_ptr<std::string const> const& getSourceName() const;

private:
    class ASTNodeFactory;

    /// Start position of the current token
    int getPosition() const;
    /// End position of the current token
    int getEndPosition() const;

    struct VarDeclParserOptions
    {
        VarDeclParserOptions() {}
        bool allowVar = false;
        bool isStateVariable = false;
        bool allowIndexed = false;
        bool allowEmptyName = false;
        bool allowInitialValue = false;
        bool allowLocationSpecifier = false;
    };

    ///@{
    ///@name Parsing functions for the AST nodes
    ASTPointer<ImportDirective> parseImportDirective();
    ASTPointer<ContractDefinition> parseContractDefinition();
    ASTPointer<InheritanceSpecifier> parseInheritanceSpecifier();
    Declaration::Visibility parseVisibilitySpecifier(Token::Value _token);
    ASTPointer<FunctionDefinition> parseFunctionDefinition(ASTString const* _contractName);
    ASTPointer<StructDefinition> parseStructDefinition();
    ASTPointer<EnumDefinition> parseEnumDefinition();
    ASTPointer<EnumValue> parseEnumValue();
    ASTPointer<VariableDeclaration> parseVariableDeclaration(VarDeclParserOptions const& _options = VarDeclParserOptions(),
        ASTPointer<TypeName> const& _lookAheadArrayType = ASTPointer<TypeName>());
    ASTPointer<ModifierDefinition> parseModifierDefinition();
    ASTPointer<EventDefinition> parseEventDefinition();
    ASTPointer<ModifierInvocation> parseModifierInvocation();
    ASTPointer<Identifier> parseIdentifier();
    ASTPointer<TypeName> parseTypeName(bool _allowVar);
    ASTPointer<Mapping> parseMapping();
    ASTPointer<ParameterList> parseParameterList(
        VarDeclParserOptions const& _options,
        bool _allowEmpty = true
    );
    ASTPointer<Block> parseBlock();
    ASTPointer<Statement> parseStatement();
    ASTPointer<IfStatement> parseIfStatement();
    ASTPointer<WhileStatement> parseWhileStatement();
    ASTPointer<ForStatement> parseForStatement();
    /// A "simple statement" can be a variable declaration statement or an expression statement.
    ASTPointer<Statement> parseSimpleStatement();
    ASTPointer<VariableDeclarationStatement> parseVariableDeclarationStatement(
        ASTPointer<TypeName> const& _lookAheadArrayType = ASTPointer<TypeName>());
    ASTPointer<ExpressionStatement> parseExpressionStatement(
        ASTPointer<Expression> const& _lookAheadIndexAccessStructure = ASTPointer<Expression>());
    ASTPointer<Expression> parseExpression(
        ASTPointer<Expression> const& _lookAheadIndexAccessStructure = ASTPointer<Expression>());
    ASTPointer<Expression> parseBinaryExpression(int _minPrecedence = 4,
        ASTPointer<Expression> const& _lookAheadIndexAccessStructure = ASTPointer<Expression>());
    ASTPointer<Expression> parseUnaryExpression(
        ASTPointer<Expression> const& _lookAheadIndexAccessStructure = ASTPointer<Expression>());
    ASTPointer<Expression> parseLeftHandSideExpression(
        ASTPointer<Expression> const& _lookAheadIndexAccessStructure = ASTPointer<Expression>());
    ASTPointer<Expression> parsePrimaryExpression();
    std::vector<ASTPointer<Expression>> parseFunctionCallListArguments();
    std::pair<std::vector<ASTPointer<Expression>>, std::vector<ASTPointer<ASTString>>> parseFunctionCallArguments();
    ///@}

    ///@{
    ///@name Helper functions

    /// Used as return value of @see peekStatementType.
    enum class LookAheadInfo
    {
        IndexAccessStructure, VariableDeclarationStatement, ExpressionStatement
    };

    /// Performs limited look-ahead to distinguish between variable declaration and expression statement.
    /// For source code of the form "a[][8]" ("IndexAccessStructure"), this is not possible to
    /// decide with constant look-ahead.
    LookAheadInfo peekStatementType() const;
    /// Returns a typename parsed in look-ahead fashion from something like "a[8][2**70]".
    ASTPointer<TypeName> typeNameIndexAccessStructure(
        ASTPointer<PrimaryExpression> const& _primary,
        std::vector<std::pair<ASTPointer<Expression>, SourceLocation>> const& _indices);
    /// Returns an expression parsed in look-ahead fashion from something like "a[8][2**70]".
    ASTPointer<Expression> expressionFromIndexAccessStructure(
        ASTPointer<PrimaryExpression> const& _primary,
        std::vector<std::pair<ASTPointer<Expression>, SourceLocation>> const& _indices);
    /// If current token value is not _value, throw exception otherwise advance token.
    void expectToken(Token::Value _value);
    Token::Value expectAssignmentOperator();
    ASTPointer<ASTString> expectIdentifierToken();
    ASTPointer<ASTString> getLiteralAndAdvance();
    ///@}

    /// Creates an empty ParameterList at the current location (used if parameters can be omitted).
    ASTPointer<ParameterList> createEmptyParameterList();

    /// Creates a @ref ParserError exception and annotates it with the current position and the
    /// given @a _description.
    ParserError createParserError(std::string const& _description) const;

    std::shared_ptr<Scanner> m_scanner;
    /// Flag that signifies whether '_' is parsed as a PlaceholderStatement or a regular identifier.
    bool m_insideModifier = false;
};

}
}