solidity/Parser.cpp
Christian 7f19f3d133 Contract compiler and also add ExpressionStatement to AST.
ExpressionStatement functions as glue between Statements and Expressions.

This way it is possible to detect when the border between statements and
expressions is crossed while walking the AST. Note that ExpressionStatement is
not the only border, almost every statement can contains expressions.
2014-10-30 01:25:42 +01:00

554 lines
17 KiB
C++

/*
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.
*/
#include <libdevcore/Log.h>
#include <libsolidity/BaseTypes.h>
#include <libsolidity/Parser.h>
#include <libsolidity/Scanner.h>
#include <libsolidity/Exceptions.h>
namespace dev
{
namespace solidity
{
ASTPointer<ContractDefinition> Parser::parse(std::shared_ptr<Scanner> const& _scanner)
{
m_scanner = _scanner;
return parseContractDefinition();
}
/// AST node factory that also tracks the begin and end position of an AST node
/// while it is being parsed
class Parser::ASTNodeFactory
{
public:
ASTNodeFactory(Parser const& _parser): m_parser(_parser), m_location(_parser.getPosition(), -1) {}
void markEndPosition() { m_location.end = m_parser.getEndPosition(); }
void setLocationEmpty() { m_location.end = m_location.start; }
/// Set the end position to the one of the given node.
void setEndPositionFromNode(ASTPointer<ASTNode> const& _node) { m_location.end = _node->getLocation().end; }
template <class NodeType, typename... Args>
ASTPointer<NodeType> createNode(Args&& ... _args)
{
if (m_location.end < 0)
markEndPosition();
return std::make_shared<NodeType>(m_location, std::forward<Args>(_args)...);
}
private:
Parser const& m_parser;
Location m_location;
};
int Parser::getPosition() const
{
return m_scanner->getCurrentLocation().start;
}
int Parser::getEndPosition() const
{
return m_scanner->getCurrentLocation().end;
}
ASTPointer<ContractDefinition> Parser::parseContractDefinition()
{
ASTNodeFactory nodeFactory(*this);
expectToken(Token::CONTRACT);
ASTPointer<ASTString> name = expectIdentifierToken();
expectToken(Token::LBRACE);
std::vector<ASTPointer<StructDefinition>> structs;
std::vector<ASTPointer<VariableDeclaration>> stateVariables;
std::vector<ASTPointer<FunctionDefinition>> functions;
bool visibilityIsPublic = true;
while (true)
{
Token::Value currentToken = m_scanner->getCurrentToken();
if (currentToken == Token::RBRACE)
break;
else if (currentToken == Token::PUBLIC || currentToken == Token::PRIVATE)
{
visibilityIsPublic = (m_scanner->getCurrentToken() == Token::PUBLIC);
m_scanner->next();
expectToken(Token::COLON);
}
else if (currentToken == Token::FUNCTION)
functions.push_back(parseFunctionDefinition(visibilityIsPublic));
else if (currentToken == Token::STRUCT)
structs.push_back(parseStructDefinition());
else if (currentToken == Token::IDENTIFIER || currentToken == Token::MAPPING ||
Token::isElementaryTypeName(currentToken))
{
bool const allowVar = false;
stateVariables.push_back(parseVariableDeclaration(allowVar));
expectToken(Token::SEMICOLON);
}
else
BOOST_THROW_EXCEPTION(createParserError("Function, variable or struct declaration expected."));
}
nodeFactory.markEndPosition();
expectToken(Token::RBRACE);
expectToken(Token::EOS);
return nodeFactory.createNode<ContractDefinition>(name, structs, stateVariables, functions);
}
ASTPointer<FunctionDefinition> Parser::parseFunctionDefinition(bool _isPublic)
{
ASTNodeFactory nodeFactory(*this);
expectToken(Token::FUNCTION);
ASTPointer<ASTString> name(expectIdentifierToken());
ASTPointer<ParameterList> parameters(parseParameterList());
bool isDeclaredConst = false;
if (m_scanner->getCurrentToken() == Token::CONST)
{
isDeclaredConst = true;
m_scanner->next();
}
ASTPointer<ParameterList> returnParameters;
if (m_scanner->getCurrentToken() == Token::RETURNS)
{
bool const permitEmptyParameterList = false;
m_scanner->next();
returnParameters = parseParameterList(permitEmptyParameterList);
}
else
{
// create an empty parameter list at a zero-length location
ASTNodeFactory nodeFactory(*this);
nodeFactory.setLocationEmpty();
returnParameters = nodeFactory.createNode<ParameterList>(std::vector<ASTPointer<VariableDeclaration>>());
}
ASTPointer<Block> block = parseBlock();
nodeFactory.setEndPositionFromNode(block);
return nodeFactory.createNode<FunctionDefinition>(name, _isPublic, parameters,
isDeclaredConst, returnParameters, block);
}
ASTPointer<StructDefinition> Parser::parseStructDefinition()
{
ASTNodeFactory nodeFactory(*this);
expectToken(Token::STRUCT);
ASTPointer<ASTString> name = expectIdentifierToken();
std::vector<ASTPointer<VariableDeclaration>> members;
expectToken(Token::LBRACE);
while (m_scanner->getCurrentToken() != Token::RBRACE)
{
bool const allowVar = false;
members.push_back(parseVariableDeclaration(allowVar));
expectToken(Token::SEMICOLON);
}
nodeFactory.markEndPosition();
expectToken(Token::RBRACE);
return nodeFactory.createNode<StructDefinition>(name, members);
}
ASTPointer<VariableDeclaration> Parser::parseVariableDeclaration(bool _allowVar)
{
ASTNodeFactory nodeFactory(*this);
ASTPointer<TypeName> type = parseTypeName(_allowVar);
nodeFactory.markEndPosition();
return nodeFactory.createNode<VariableDeclaration>(type, expectIdentifierToken());
}
ASTPointer<TypeName> Parser::parseTypeName(bool _allowVar)
{
ASTPointer<TypeName> type;
Token::Value token = m_scanner->getCurrentToken();
if (Token::isElementaryTypeName(token))
{
type = ASTNodeFactory(*this).createNode<ElementaryTypeName>(token);
m_scanner->next();
}
else if (token == Token::VAR)
{
if (!_allowVar)
BOOST_THROW_EXCEPTION(createParserError("Expected explicit type name."));
m_scanner->next();
}
else if (token == Token::MAPPING)
{
type = parseMapping();
}
else if (token == Token::IDENTIFIER)
{
ASTNodeFactory nodeFactory(*this);
nodeFactory.markEndPosition();
type = nodeFactory.createNode<UserDefinedTypeName>(expectIdentifierToken());
}
else
BOOST_THROW_EXCEPTION(createParserError("Expected type name"));
return type;
}
ASTPointer<Mapping> Parser::parseMapping()
{
ASTNodeFactory nodeFactory(*this);
expectToken(Token::MAPPING);
expectToken(Token::LPAREN);
if (!Token::isElementaryTypeName(m_scanner->getCurrentToken()))
BOOST_THROW_EXCEPTION(createParserError("Expected elementary type name for mapping key type"));
ASTPointer<ElementaryTypeName> keyType;
keyType = ASTNodeFactory(*this).createNode<ElementaryTypeName>(m_scanner->getCurrentToken());
m_scanner->next();
expectToken(Token::ARROW);
bool const allowVar = false;
ASTPointer<TypeName> valueType = parseTypeName(allowVar);
nodeFactory.markEndPosition();
expectToken(Token::RPAREN);
return nodeFactory.createNode<Mapping>(keyType, valueType);
}
ASTPointer<ParameterList> Parser::parseParameterList(bool _allowEmpty)
{
ASTNodeFactory nodeFactory(*this);
std::vector<ASTPointer<VariableDeclaration>> parameters;
expectToken(Token::LPAREN);
if (!_allowEmpty || m_scanner->getCurrentToken() != Token::RPAREN)
{
bool const allowVar = false;
parameters.push_back(parseVariableDeclaration(allowVar));
while (m_scanner->getCurrentToken() != Token::RPAREN)
{
expectToken(Token::COMMA);
parameters.push_back(parseVariableDeclaration(allowVar));
}
}
nodeFactory.markEndPosition();
m_scanner->next();
return nodeFactory.createNode<ParameterList>(parameters);
}
ASTPointer<Block> Parser::parseBlock()
{
ASTNodeFactory nodeFactory(*this);
expectToken(Token::LBRACE);
std::vector<ASTPointer<Statement>> statements;
while (m_scanner->getCurrentToken() != Token::RBRACE)
statements.push_back(parseStatement());
nodeFactory.markEndPosition();
expectToken(Token::RBRACE);
return nodeFactory.createNode<Block>(statements);
}
ASTPointer<Statement> Parser::parseStatement()
{
ASTPointer<Statement> statement;
switch (m_scanner->getCurrentToken())
{
case Token::IF:
return parseIfStatement();
case Token::WHILE:
return parseWhileStatement();
case Token::LBRACE:
return parseBlock();
// starting from here, all statements must be terminated by a semicolon
case Token::CONTINUE:
statement = ASTNodeFactory(*this).createNode<Continue>();
m_scanner->next();
break;
case Token::BREAK:
statement = ASTNodeFactory(*this).createNode<Break>();
m_scanner->next();
break;
case Token::RETURN:
{
ASTNodeFactory nodeFactory(*this);
ASTPointer<Expression> expression;
if (m_scanner->next() != Token::SEMICOLON)
{
expression = parseExpression();
nodeFactory.setEndPositionFromNode(expression);
}
statement = nodeFactory.createNode<Return>(expression);
}
break;
default:
// distinguish between variable definition (and potentially assignment) and expression statement
// (which include assignments to other expressions and pre-declared variables)
// We have a variable definition if we get a keyword that specifies a type name, or
// in the case of a user-defined type, we have two identifiers following each other.
if (m_scanner->getCurrentToken() == Token::MAPPING ||
m_scanner->getCurrentToken() == Token::VAR ||
Token::isElementaryTypeName(m_scanner->getCurrentToken()) ||
(m_scanner->getCurrentToken() == Token::IDENTIFIER &&
m_scanner->peekNextToken() == Token::IDENTIFIER))
statement = parseVariableDefinition();
else // "ordinary" expression statement
statement = parseExpressionStatement();
}
expectToken(Token::SEMICOLON);
return statement;
}
ASTPointer<IfStatement> Parser::parseIfStatement()
{
ASTNodeFactory nodeFactory(*this);
expectToken(Token::IF);
expectToken(Token::LPAREN);
ASTPointer<Expression> condition = parseExpression();
expectToken(Token::RPAREN);
ASTPointer<Statement> trueBody = parseStatement();
ASTPointer<Statement> falseBody;
if (m_scanner->getCurrentToken() == Token::ELSE)
{
m_scanner->next();
falseBody = parseStatement();
nodeFactory.setEndPositionFromNode(falseBody);
}
else
nodeFactory.setEndPositionFromNode(trueBody);
return nodeFactory.createNode<IfStatement>(condition, trueBody, falseBody);
}
ASTPointer<WhileStatement> Parser::parseWhileStatement()
{
ASTNodeFactory nodeFactory(*this);
expectToken(Token::WHILE);
expectToken(Token::LPAREN);
ASTPointer<Expression> condition = parseExpression();
expectToken(Token::RPAREN);
ASTPointer<Statement> body = parseStatement();
nodeFactory.setEndPositionFromNode(body);
return nodeFactory.createNode<WhileStatement>(condition, body);
}
ASTPointer<VariableDefinition> Parser::parseVariableDefinition()
{
ASTNodeFactory nodeFactory(*this);
bool const allowVar = true;
ASTPointer<VariableDeclaration> variable = parseVariableDeclaration(allowVar);
ASTPointer<Expression> value;
if (m_scanner->getCurrentToken() == Token::ASSIGN)
{
m_scanner->next();
value = parseExpression();
nodeFactory.setEndPositionFromNode(value);
}
else
nodeFactory.setEndPositionFromNode(variable);
return nodeFactory.createNode<VariableDefinition>(variable, value);
}
ASTPointer<ExpressionStatement> Parser::parseExpressionStatement()
{
ASTNodeFactory nodeFactory(*this);
ASTPointer<Expression> expression = parseExpression();
nodeFactory.setEndPositionFromNode(expression);
return nodeFactory.createNode<ExpressionStatement>(expression);
}
ASTPointer<Expression> Parser::parseExpression()
{
ASTNodeFactory nodeFactory(*this);
ASTPointer<Expression> expression = parseBinaryExpression();
if (!Token::isAssignmentOp(m_scanner->getCurrentToken()))
return expression;
Token::Value assignmentOperator = expectAssignmentOperator();
ASTPointer<Expression> rightHandSide = parseExpression();
nodeFactory.setEndPositionFromNode(rightHandSide);
return nodeFactory.createNode<Assignment>(expression, assignmentOperator, rightHandSide);
}
ASTPointer<Expression> Parser::parseBinaryExpression(int _minPrecedence)
{
ASTNodeFactory nodeFactory(*this);
ASTPointer<Expression> expression = parseUnaryExpression();
int precedence = Token::precedence(m_scanner->getCurrentToken());
for (; precedence >= _minPrecedence; --precedence)
{
while (Token::precedence(m_scanner->getCurrentToken()) == precedence)
{
Token::Value op = m_scanner->getCurrentToken();
m_scanner->next();
ASTPointer<Expression> right = parseBinaryExpression(precedence + 1);
nodeFactory.setEndPositionFromNode(right);
expression = nodeFactory.createNode<BinaryOperation>(expression, op, right);
}
}
return expression;
}
ASTPointer<Expression> Parser::parseUnaryExpression()
{
ASTNodeFactory nodeFactory(*this);
Token::Value token = m_scanner->getCurrentToken();
if (Token::isUnaryOp(token) || Token::isCountOp(token))
{
// prefix expression
m_scanner->next();
ASTPointer<Expression> subExpression = parseUnaryExpression();
nodeFactory.setEndPositionFromNode(subExpression);
return nodeFactory.createNode<UnaryOperation>(token, subExpression, true);
}
else
{
// potential postfix expression
ASTPointer<Expression> subExpression = parseLeftHandSideExpression();
token = m_scanner->getCurrentToken();
if (!Token::isCountOp(token))
return subExpression;
nodeFactory.markEndPosition();
m_scanner->next();
return nodeFactory.createNode<UnaryOperation>(token, subExpression, false);
}
}
ASTPointer<Expression> Parser::parseLeftHandSideExpression()
{
ASTNodeFactory nodeFactory(*this);
ASTPointer<Expression> expression = parsePrimaryExpression();
while (true)
{
switch (m_scanner->getCurrentToken())
{
case Token::LBRACK:
{
m_scanner->next();
ASTPointer<Expression> index = parseExpression();
nodeFactory.markEndPosition();
expectToken(Token::RBRACK);
expression = nodeFactory.createNode<IndexAccess>(expression, index);
}
break;
case Token::PERIOD:
{
m_scanner->next();
nodeFactory.markEndPosition();
expression = nodeFactory.createNode<MemberAccess>(expression, expectIdentifierToken());
}
break;
case Token::LPAREN:
{
m_scanner->next();
std::vector<ASTPointer<Expression>> arguments = parseFunctionCallArguments();
nodeFactory.markEndPosition();
expectToken(Token::RPAREN);
expression = nodeFactory.createNode<FunctionCall>(expression, arguments);
}
break;
default:
return expression;
}
}
}
ASTPointer<Expression> Parser::parsePrimaryExpression()
{
ASTNodeFactory nodeFactory(*this);
Token::Value token = m_scanner->getCurrentToken();
ASTPointer<Expression> expression;
switch (token)
{
case Token::TRUE_LITERAL:
case Token::FALSE_LITERAL:
expression = nodeFactory.createNode<Literal>(token, getLiteralAndAdvance());
break;
case Token::NUMBER:
case Token::STRING_LITERAL:
nodeFactory.markEndPosition();
expression = nodeFactory.createNode<Literal>(token, getLiteralAndAdvance());
break;
case Token::IDENTIFIER:
nodeFactory.markEndPosition();
expression = nodeFactory.createNode<Identifier>(getLiteralAndAdvance());
break;
case Token::LPAREN:
{
m_scanner->next();
ASTPointer<Expression> expression = parseExpression();
expectToken(Token::RPAREN);
return expression;
}
default:
if (Token::isElementaryTypeName(token))
{
// used for casts
expression = nodeFactory.createNode<ElementaryTypeNameExpression>(token);
m_scanner->next();
}
else
{
BOOST_THROW_EXCEPTION(createParserError("Expected primary expression."));
return ASTPointer<Expression>(); // this is not reached
}
break;
}
return expression;
}
std::vector<ASTPointer<Expression>> Parser::parseFunctionCallArguments()
{
std::vector<ASTPointer<Expression>> arguments;
if (m_scanner->getCurrentToken() != Token::RPAREN)
{
arguments.push_back(parseExpression());
while (m_scanner->getCurrentToken() != Token::RPAREN)
{
expectToken(Token::COMMA);
arguments.push_back(parseExpression());
}
}
return arguments;
}
void Parser::expectToken(Token::Value _value)
{
if (m_scanner->getCurrentToken() != _value)
BOOST_THROW_EXCEPTION(createParserError(std::string("Expected token ") + std::string(Token::getName(_value))));
m_scanner->next();
}
Token::Value Parser::expectAssignmentOperator()
{
Token::Value op = m_scanner->getCurrentToken();
if (!Token::isAssignmentOp(op))
BOOST_THROW_EXCEPTION(createParserError("Expected assignment operator"));
m_scanner->next();
return op;
}
ASTPointer<ASTString> Parser::expectIdentifierToken()
{
if (m_scanner->getCurrentToken() != Token::IDENTIFIER)
BOOST_THROW_EXCEPTION(createParserError("Expected identifier"));
return getLiteralAndAdvance();
}
ASTPointer<ASTString> Parser::getLiteralAndAdvance()
{
ASTPointer<ASTString> identifier = std::make_shared<ASTString>(m_scanner->getCurrentLiteral());
m_scanner->next();
return identifier;
}
ParserError Parser::createParserError(std::string const& _description) const
{
return ParserError() << errinfo_sourcePosition(getPosition()) << errinfo_comment(_description);
}
}
}