solidity/Parser.cpp
2015-03-06 12:46:23 +01:00

1002 lines
32 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 <vector>
#include <libdevcore/Log.h>
#include <libevmcore/SourceLocation.h>
#include <libsolidity/Parser.h>
#include <libsolidity/Scanner.h>
#include <libsolidity/Exceptions.h>
using namespace std;
namespace dev
{
namespace solidity
{
/// 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, _parser.getSourceName()) {}
ASTNodeFactory(Parser const& _parser, ASTPointer<ASTNode> const& _childNode):
m_parser(_parser), m_location(_childNode->getLocation()) {}
void markEndPosition() { m_location.end = m_parser.getEndPosition(); }
void setLocation(SourceLocation const& _location) { m_location = _location; }
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 make_shared<NodeType>(m_location, forward<Args>(_args)...);
}
private:
Parser const& m_parser;
SourceLocation m_location;
};
ASTPointer<SourceUnit> Parser::parse(shared_ptr<Scanner> const& _scanner)
{
m_scanner = _scanner;
ASTNodeFactory nodeFactory(*this);
vector<ASTPointer<ASTNode>> nodes;
while (_scanner->getCurrentToken() != Token::EOS)
{
switch (m_scanner->getCurrentToken())
{
case Token::Import:
nodes.push_back(parseImportDirective());
break;
case Token::Contract:
nodes.push_back(parseContractDefinition());
break;
default:
BOOST_THROW_EXCEPTION(createParserError(std::string("Expected import directive or contract definition.")));
}
}
return nodeFactory.createNode<SourceUnit>(nodes);
}
std::shared_ptr<const string> const& Parser::getSourceName() const
{
return m_scanner->getSourceName();
}
int Parser::getPosition() const
{
return m_scanner->getCurrentLocation().start;
}
int Parser::getEndPosition() const
{
return m_scanner->getCurrentLocation().end;
}
ASTPointer<ImportDirective> Parser::parseImportDirective()
{
ASTNodeFactory nodeFactory(*this);
expectToken(Token::Import);
if (m_scanner->getCurrentToken() != Token::StringLiteral)
BOOST_THROW_EXCEPTION(createParserError("Expected string literal (URL)."));
ASTPointer<ASTString> url = getLiteralAndAdvance();
nodeFactory.markEndPosition();
expectToken(Token::Semicolon);
return nodeFactory.createNode<ImportDirective>(url);
}
ASTPointer<ContractDefinition> Parser::parseContractDefinition()
{
ASTNodeFactory nodeFactory(*this);
ASTPointer<ASTString> docString;
if (m_scanner->getCurrentCommentLiteral() != "")
docString = make_shared<ASTString>(m_scanner->getCurrentCommentLiteral());
expectToken(Token::Contract);
ASTPointer<ASTString> name = expectIdentifierToken();
vector<ASTPointer<InheritanceSpecifier>> baseContracts;
vector<ASTPointer<StructDefinition>> structs;
vector<ASTPointer<EnumDefinition>> enums;
vector<ASTPointer<VariableDeclaration>> stateVariables;
vector<ASTPointer<FunctionDefinition>> functions;
vector<ASTPointer<ModifierDefinition>> modifiers;
vector<ASTPointer<EventDefinition>> events;
if (m_scanner->getCurrentToken() == Token::Is)
do
{
m_scanner->next();
baseContracts.push_back(parseInheritanceSpecifier());
}
while (m_scanner->getCurrentToken() == Token::Comma);
expectToken(Token::LBrace);
while (true)
{
Token::Value currentToken = m_scanner->getCurrentToken();
if (currentToken == Token::RBrace)
break;
else if (currentToken == Token::Function)
functions.push_back(parseFunctionDefinition(name.get()));
else if (currentToken == Token::Struct)
structs.push_back(parseStructDefinition());
else if (currentToken == Token::Enum)
enums.push_back(parseEnumDefinition());
else if (currentToken == Token::Identifier || currentToken == Token::Mapping ||
Token::isElementaryTypeName(currentToken))
{
VarDeclParserOptions options;
options.isStateVariable = true;
options.allowInitialValue = true;
stateVariables.push_back(parseVariableDeclaration(options));
expectToken(Token::Semicolon);
}
else if (currentToken == Token::Modifier)
modifiers.push_back(parseModifierDefinition());
else if (currentToken == Token::Event)
events.push_back(parseEventDefinition());
else
BOOST_THROW_EXCEPTION(createParserError("Function, variable, struct or modifier declaration expected."));
}
nodeFactory.markEndPosition();
expectToken(Token::RBrace);
return nodeFactory.createNode<ContractDefinition>(name, docString, baseContracts, structs, enums,
stateVariables, functions, modifiers, events);
}
ASTPointer<InheritanceSpecifier> Parser::parseInheritanceSpecifier()
{
ASTNodeFactory nodeFactory(*this);
ASTPointer<Identifier> name(parseIdentifier());
vector<ASTPointer<Expression>> arguments;
if (m_scanner->getCurrentToken() == Token::LParen)
{
m_scanner->next();
arguments = parseFunctionCallListArguments();
nodeFactory.markEndPosition();
expectToken(Token::RParen);
}
else
nodeFactory.setEndPositionFromNode(name);
return nodeFactory.createNode<InheritanceSpecifier>(name, arguments);
}
Declaration::Visibility Parser::parseVisibilitySpecifier(Token::Value _token)
{
Declaration::Visibility visibility(Declaration::Visibility::Default);
if (_token == Token::Public)
visibility = Declaration::Visibility::Public;
else if (_token == Token::Internal)
visibility = Declaration::Visibility::Internal;
else if (_token == Token::Private)
visibility = Declaration::Visibility::Private;
else if (_token == Token::External)
visibility = Declaration::Visibility::External;
else
solAssert(false, "Invalid visibility specifier.");
m_scanner->next();
return visibility;
}
ASTPointer<FunctionDefinition> Parser::parseFunctionDefinition(ASTString const* _contractName)
{
ASTNodeFactory nodeFactory(*this);
ASTPointer<ASTString> docstring;
if (m_scanner->getCurrentCommentLiteral() != "")
docstring = make_shared<ASTString>(m_scanner->getCurrentCommentLiteral());
expectToken(Token::Function);
ASTPointer<ASTString> name;
if (m_scanner->getCurrentToken() == Token::LParen)
name = make_shared<ASTString>(); // anonymous function
else
name = expectIdentifierToken();
ASTPointer<ParameterList> parameters(parseParameterList());
bool isDeclaredConst = false;
Declaration::Visibility visibility(Declaration::Visibility::Default);
vector<ASTPointer<ModifierInvocation>> modifiers;
while (true)
{
Token::Value token = m_scanner->getCurrentToken();
if (token == Token::Const)
{
isDeclaredConst = true;
m_scanner->next();
}
else if (token == Token::Identifier)
modifiers.push_back(parseModifierInvocation());
else if (Token::isVisibilitySpecifier(token))
{
if (visibility != Declaration::Visibility::Default)
BOOST_THROW_EXCEPTION(createParserError("Multiple visibility specifiers."));
visibility = parseVisibilitySpecifier(token);
}
else
break;
}
ASTPointer<ParameterList> returnParameters;
if (m_scanner->getCurrentToken() == Token::Returns)
{
bool const permitEmptyParameterList = false;
m_scanner->next();
returnParameters = parseParameterList(permitEmptyParameterList);
}
else
returnParameters = createEmptyParameterList();
ASTPointer<Block> block = parseBlock();
nodeFactory.setEndPositionFromNode(block);
bool const c_isConstructor = (_contractName && *name == *_contractName);
return nodeFactory.createNode<FunctionDefinition>(name, visibility, c_isConstructor, docstring,
parameters, isDeclaredConst, modifiers,
returnParameters, block);
}
ASTPointer<StructDefinition> Parser::parseStructDefinition()
{
ASTNodeFactory nodeFactory(*this);
expectToken(Token::Struct);
ASTPointer<ASTString> name = expectIdentifierToken();
vector<ASTPointer<VariableDeclaration>> members;
expectToken(Token::LBrace);
while (m_scanner->getCurrentToken() != Token::RBrace)
{
members.push_back(parseVariableDeclaration());
expectToken(Token::Semicolon);
}
nodeFactory.markEndPosition();
expectToken(Token::RBrace);
return nodeFactory.createNode<StructDefinition>(name, members);
}
ASTPointer<EnumValue> Parser::parseEnumValue()
{
ASTNodeFactory nodeFactory(*this);
nodeFactory.markEndPosition();
return nodeFactory.createNode<EnumValue>(expectIdentifierToken());
}
ASTPointer<EnumDefinition> Parser::parseEnumDefinition()
{
ASTNodeFactory nodeFactory(*this);
expectToken(Token::Enum);
ASTPointer<ASTString> name = expectIdentifierToken();
vector<ASTPointer<EnumValue>> members;
expectToken(Token::LBrace);
while (m_scanner->getCurrentToken() != Token::RBrace)
{
members.push_back(parseEnumValue());
if (m_scanner->getCurrentToken() == Token::RBrace)
break;
expectToken(Token::Comma);
if (m_scanner->getCurrentToken() != Token::Identifier)
BOOST_THROW_EXCEPTION(createParserError("Expected Identifier after ','"));
}
nodeFactory.markEndPosition();
expectToken(Token::RBrace);
return nodeFactory.createNode<EnumDefinition>(name, members);
}
ASTPointer<VariableDeclaration> Parser::parseVariableDeclaration(
VarDeclParserOptions const& _options, ASTPointer<TypeName> const& _lookAheadArrayType)
{
ASTNodeFactory nodeFactory = _lookAheadArrayType ?
ASTNodeFactory(*this, _lookAheadArrayType) : ASTNodeFactory(*this);
ASTPointer<TypeName> type;
if (_lookAheadArrayType)
type = _lookAheadArrayType;
else
{
type = parseTypeName(_options.allowVar);
if (type != nullptr)
nodeFactory.setEndPositionFromNode(type);
}
bool isIndexed = false;
ASTPointer<ASTString> identifier;
Token::Value token = m_scanner->getCurrentToken();
Declaration::Visibility visibility(Declaration::Visibility::Default);
if (_options.isStateVariable && Token::isVariableVisibilitySpecifier(token))
visibility = parseVisibilitySpecifier(token);
if (_options.allowIndexed && token == Token::Indexed)
{
isIndexed = true;
m_scanner->next();
}
nodeFactory.markEndPosition();
if (_options.allowEmptyName && m_scanner->getCurrentToken() != Token::Identifier)
{
identifier = make_shared<ASTString>("");
solAssert(type != nullptr, "");
nodeFactory.setEndPositionFromNode(type);
}
else
identifier = expectIdentifierToken();
ASTPointer<Expression> value;
if (_options.allowInitialValue)
{
if (m_scanner->getCurrentToken() == Token::Assign)
{
m_scanner->next();
value = parseExpression();
nodeFactory.setEndPositionFromNode(value);
}
}
return nodeFactory.createNode<VariableDeclaration>(type, identifier, value,
visibility, _options.isStateVariable,
isIndexed);
}
ASTPointer<ModifierDefinition> Parser::parseModifierDefinition()
{
ScopeGuard resetModifierFlag([this]() { m_insideModifier = false; });
m_insideModifier = true;
ASTNodeFactory nodeFactory(*this);
ASTPointer<ASTString> docstring;
if (m_scanner->getCurrentCommentLiteral() != "")
docstring = make_shared<ASTString>(m_scanner->getCurrentCommentLiteral());
expectToken(Token::Modifier);
ASTPointer<ASTString> name(expectIdentifierToken());
ASTPointer<ParameterList> parameters;
if (m_scanner->getCurrentToken() == Token::LParen)
parameters = parseParameterList();
else
parameters = createEmptyParameterList();
ASTPointer<Block> block = parseBlock();
nodeFactory.setEndPositionFromNode(block);
return nodeFactory.createNode<ModifierDefinition>(name, docstring, parameters, block);
}
ASTPointer<EventDefinition> Parser::parseEventDefinition()
{
ASTNodeFactory nodeFactory(*this);
ASTPointer<ASTString> docstring;
if (m_scanner->getCurrentCommentLiteral() != "")
docstring = make_shared<ASTString>(m_scanner->getCurrentCommentLiteral());
expectToken(Token::Event);
ASTPointer<ASTString> name(expectIdentifierToken());
ASTPointer<ParameterList> parameters;
if (m_scanner->getCurrentToken() == Token::LParen)
parameters = parseParameterList(true, true);
else
parameters = createEmptyParameterList();
nodeFactory.markEndPosition();
expectToken(Token::Semicolon);
return nodeFactory.createNode<EventDefinition>(name, docstring, parameters);
}
ASTPointer<ModifierInvocation> Parser::parseModifierInvocation()
{
ASTNodeFactory nodeFactory(*this);
ASTPointer<Identifier> name(parseIdentifier());
vector<ASTPointer<Expression>> arguments;
if (m_scanner->getCurrentToken() == Token::LParen)
{
m_scanner->next();
arguments = parseFunctionCallListArguments();
nodeFactory.markEndPosition();
expectToken(Token::RParen);
}
else
nodeFactory.setEndPositionFromNode(name);
return nodeFactory.createNode<ModifierInvocation>(name, arguments);
}
ASTPointer<Identifier> Parser::parseIdentifier()
{
ASTNodeFactory nodeFactory(*this);
nodeFactory.markEndPosition();
return nodeFactory.createNode<Identifier>(expectIdentifierToken());
}
ASTPointer<TypeName> Parser::parseTypeName(bool _allowVar)
{
ASTNodeFactory nodeFactory(*this);
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"));
// Parse "[...]" postfixes for arrays.
while (m_scanner->getCurrentToken() == Token::LBrack)
{
m_scanner->next();
ASTPointer<Expression> length;
if (m_scanner->getCurrentToken() != Token::RBrack)
length = parseExpression();
nodeFactory.markEndPosition();
expectToken(Token::RBrack);
type = nodeFactory.createNode<ArrayTypeName>(type, length);
}
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, bool _allowIndexed)
{
ASTNodeFactory nodeFactory(*this);
vector<ASTPointer<VariableDeclaration>> parameters;
VarDeclParserOptions options;
options.allowIndexed = _allowIndexed;
options.allowEmptyName = true;
expectToken(Token::LParen);
if (!_allowEmpty || m_scanner->getCurrentToken() != Token::RParen)
{
parameters.push_back(parseVariableDeclaration(options));
while (m_scanner->getCurrentToken() != Token::RParen)
{
expectToken(Token::Comma);
parameters.push_back(parseVariableDeclaration(options));
}
}
nodeFactory.markEndPosition();
m_scanner->next();
return nodeFactory.createNode<ParameterList>(parameters);
}
ASTPointer<Block> Parser::parseBlock()
{
ASTNodeFactory nodeFactory(*this);
expectToken(Token::LBrace);
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::For:
return parseForStatement();
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;
}
case Token::Identifier:
if (m_insideModifier && m_scanner->getCurrentLiteral() == "_")
{
statement = ASTNodeFactory(*this).createNode<PlaceholderStatement>();
m_scanner->next();
return statement;
}
// fall-through
default:
statement = parseSimpleStatement();
}
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<ForStatement> Parser::parseForStatement()
{
ASTNodeFactory nodeFactory(*this);
ASTPointer<Statement> initExpression;
ASTPointer<Expression> conditionExpression;
ASTPointer<ExpressionStatement> loopExpression;
expectToken(Token::For);
expectToken(Token::LParen);
// LTODO: Maybe here have some predicate like peekExpression() instead of checking for semicolon and RParen?
if (m_scanner->getCurrentToken() != Token::Semicolon)
initExpression = parseSimpleStatement();
expectToken(Token::Semicolon);
if (m_scanner->getCurrentToken() != Token::Semicolon)
conditionExpression = parseExpression();
expectToken(Token::Semicolon);
if (m_scanner->getCurrentToken() != Token::RParen)
loopExpression = parseExpressionStatement();
expectToken(Token::RParen);
ASTPointer<Statement> body = parseStatement();
nodeFactory.setEndPositionFromNode(body);
return nodeFactory.createNode<ForStatement>(initExpression,
conditionExpression,
loopExpression,
body);
}
ASTPointer<Statement> Parser::parseSimpleStatement()
{
// These two cases are very hard to distinguish:
// x[7 * 20 + 3] a; - x[7 * 20 + 3] = 9;
// In the first case, x is a type name, in the second it is the name of a variable.
switch (peekStatementType())
{
case LookAheadInfo::VariableDeclarationStatement:
return parseVariableDeclarationStatement();
case LookAheadInfo::ExpressionStatement:
return parseExpressionStatement();
default:
break;
}
// At this point, we have '(Identifier|ElementaryTypeName) "["'.
// We parse '(Identifier|ElementaryTypeName) ( "[" Expression "]" )+' and then decide whether to hand this over
// to ExpressionStatement or create a VariableDeclarationStatement out of it.
ASTPointer<PrimaryExpression> primary;
if (m_scanner->getCurrentToken() == Token::Identifier)
primary = parseIdentifier();
else
{
primary = ASTNodeFactory(*this).createNode<ElementaryTypeNameExpression>(m_scanner->getCurrentToken());
m_scanner->next();
}
vector<pair<ASTPointer<Expression>, SourceLocation>> indices;
solAssert(m_scanner->getCurrentToken() == Token::LBrack, "");
SourceLocation indexLocation = primary->getLocation();
do
{
expectToken(Token::LBrack);
ASTPointer<Expression> index;
if (m_scanner->getCurrentToken() != Token::RBrack)
index = parseExpression();
indexLocation.end = getEndPosition();
indices.push_back(make_pair(index, indexLocation));
expectToken(Token::RBrack);
}
while (m_scanner->getCurrentToken() == Token::LBrack);
if (m_scanner->getCurrentToken() == Token::Identifier)
return parseVariableDeclarationStatement(typeNameIndexAccessStructure(primary, indices));
else
return parseExpressionStatement(expressionFromIndexAccessStructure(primary, indices));
}
ASTPointer<VariableDeclarationStatement> Parser::parseVariableDeclarationStatement(
ASTPointer<TypeName> const& _lookAheadArrayType)
{
VarDeclParserOptions options;
options.allowVar = true;
options.allowInitialValue = true;
ASTPointer<VariableDeclaration> variable = parseVariableDeclaration(options, _lookAheadArrayType);
ASTNodeFactory nodeFactory(*this, variable);
return nodeFactory.createNode<VariableDeclarationStatement>(variable);
}
ASTPointer<ExpressionStatement> Parser::parseExpressionStatement(
ASTPointer<Expression> const& _lookAheadIndexAccessStructure)
{
ASTPointer<Expression> expression = parseExpression(_lookAheadIndexAccessStructure);
return ASTNodeFactory(*this, expression).createNode<ExpressionStatement>(expression);
}
ASTPointer<Expression> Parser::parseExpression(
ASTPointer<Expression> const& _lookAheadIndexAccessStructure)
{
ASTPointer<Expression> expression = parseBinaryExpression(4, _lookAheadIndexAccessStructure);
if (!Token::isAssignmentOp(m_scanner->getCurrentToken()))
return expression;
Token::Value assignmentOperator = expectAssignmentOperator();
ASTPointer<Expression> rightHandSide = parseExpression();
ASTNodeFactory nodeFactory(*this, expression);
nodeFactory.setEndPositionFromNode(rightHandSide);
return nodeFactory.createNode<Assignment>(expression, assignmentOperator, rightHandSide);
}
ASTPointer<Expression> Parser::parseBinaryExpression(int _minPrecedence,
ASTPointer<Expression> const& _lookAheadIndexAccessStructure)
{
ASTPointer<Expression> expression = parseUnaryExpression(_lookAheadIndexAccessStructure);
ASTNodeFactory nodeFactory(*this, expression);
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(
ASTPointer<Expression> const& _lookAheadIndexAccessStructure)
{
ASTNodeFactory nodeFactory = _lookAheadIndexAccessStructure ?
ASTNodeFactory(*this, _lookAheadIndexAccessStructure) : ASTNodeFactory(*this);
Token::Value token = m_scanner->getCurrentToken();
if (!_lookAheadIndexAccessStructure && (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(_lookAheadIndexAccessStructure);
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(
ASTPointer<Expression> const& _lookAheadIndexAccessStructure)
{
ASTNodeFactory nodeFactory = _lookAheadIndexAccessStructure ?
ASTNodeFactory(*this, _lookAheadIndexAccessStructure) : ASTNodeFactory(*this);
ASTPointer<Expression> expression;
if (_lookAheadIndexAccessStructure)
expression = _lookAheadIndexAccessStructure;
else if (m_scanner->getCurrentToken() == Token::New)
{
expectToken(Token::New);
ASTPointer<Identifier> contractName(parseIdentifier());
nodeFactory.setEndPositionFromNode(contractName);
expression = nodeFactory.createNode<NewExpression>(contractName);
}
else
expression = parsePrimaryExpression();
while (true)
{
switch (m_scanner->getCurrentToken())
{
case Token::LBrack:
{
m_scanner->next();
ASTPointer<Expression> index;
if (m_scanner->getCurrentToken() != Token::RBrack)
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();
vector<ASTPointer<Expression>> arguments;
vector<ASTPointer<ASTString>> names;
std::tie(arguments, names) = parseFunctionCallArguments();
nodeFactory.markEndPosition();
expectToken(Token::RParen);
expression = nodeFactory.createNode<FunctionCall>(expression, arguments, names);
}
break;
default:
return expression;
}
}
}
ASTPointer<Expression> Parser::parsePrimaryExpression()
{
ASTNodeFactory nodeFactory(*this);
Token::Value token = m_scanner->getCurrentToken();
ASTPointer<Expression> expression;
switch (token)
{
case Token::TrueLiteral:
case Token::FalseLiteral:
expression = nodeFactory.createNode<Literal>(token, getLiteralAndAdvance());
break;
case Token::Number:
if (Token::isEtherSubdenomination(m_scanner->peekNextToken()))
{
ASTPointer<ASTString> literal = getLiteralAndAdvance();
nodeFactory.markEndPosition();
Literal::SubDenomination subdenomination = static_cast<Literal::SubDenomination>(m_scanner->getCurrentToken());
m_scanner->next();
expression = nodeFactory.createNode<Literal>(token, literal, subdenomination);
break;
}
if (Token::isTimeSubdenomination(m_scanner->peekNextToken()))
{
ASTPointer<ASTString> literal = getLiteralAndAdvance();
nodeFactory.markEndPosition();
Literal::SubDenomination subdenomination = static_cast<Literal::SubDenomination>(m_scanner->getCurrentToken());
m_scanner->next();
expression = nodeFactory.createNode<Literal>(token, literal, subdenomination);
break;
}
// fall-through
case Token::StringLiteral:
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."));
break;
}
return expression;
}
vector<ASTPointer<Expression>> Parser::parseFunctionCallListArguments()
{
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;
}
pair<vector<ASTPointer<Expression>>, vector<ASTPointer<ASTString>>> Parser::parseFunctionCallArguments()
{
pair<vector<ASTPointer<Expression>>, vector<ASTPointer<ASTString>>> ret;
Token::Value token = m_scanner->getCurrentToken();
if (token == Token::LBrace)
{
// call({arg1 : 1, arg2 : 2 })
expectToken(Token::LBrace);
while (m_scanner->getCurrentToken() != Token::RBrace)
{
ret.second.push_back(expectIdentifierToken());
expectToken(Token::Colon);
ret.first.push_back(parseExpression());
if (m_scanner->getCurrentToken() == Token::Comma)
expectToken(Token::Comma);
else
break;
}
expectToken(Token::RBrace);
}
else
ret.first = parseFunctionCallListArguments();
return ret;
}
Parser::LookAheadInfo Parser::peekStatementType() const
{
// Distinguish between variable declaration (and potentially assignment) and expression statement
// (which include assignments to other expressions and pre-declared variables).
// We have a variable declaration if we get a keyword that specifies a type name.
// If it is an identifier or an elementary type name followed by an identifier, we also have
// a variable declaration.
// If we get an identifier followed by a "[", it can be both ("type[9] a;" or "arr[9] = 7;").
// In all other cases, we have an expression statement.
Token::Value token(m_scanner->getCurrentToken());
bool mightBeTypeName = (Token::isElementaryTypeName(token) || token == Token::Identifier);
if (token == Token::Mapping || token == Token::Var ||
(mightBeTypeName && m_scanner->peekNextToken() == Token::Identifier))
return LookAheadInfo::VariableDeclarationStatement;
if (mightBeTypeName && m_scanner->peekNextToken() == Token::LBrack)
return LookAheadInfo::IndexAccessStructure;
return LookAheadInfo::ExpressionStatement;
}
ASTPointer<TypeName> Parser::typeNameIndexAccessStructure(
ASTPointer<PrimaryExpression> const& _primary, vector<pair<ASTPointer<Expression>, SourceLocation>> const& _indices)
{
ASTNodeFactory nodeFactory(*this, _primary);
ASTPointer<TypeName> type;
if (auto identifier = dynamic_cast<Identifier const*>(_primary.get()))
type = nodeFactory.createNode<UserDefinedTypeName>(make_shared<ASTString>(identifier->getName()));
else if (auto typeName = dynamic_cast<ElementaryTypeNameExpression const*>(_primary.get()))
type = nodeFactory.createNode<ElementaryTypeName>(typeName->getTypeToken());
else
solAssert(false, "Invalid type name for array look-ahead.");
for (auto const& lengthExpression: _indices)
{
nodeFactory.setLocation(lengthExpression.second);
type = nodeFactory.createNode<ArrayTypeName>(type, lengthExpression.first);
}
return type;
}
ASTPointer<Expression> Parser::expressionFromIndexAccessStructure(
ASTPointer<PrimaryExpression> const& _primary, vector<pair<ASTPointer<Expression>, SourceLocation>> const& _indices)
{
ASTNodeFactory nodeFactory(*this, _primary);
ASTPointer<Expression> expression(_primary);
for (auto const& index: _indices)
{
nodeFactory.setLocation(index.second);
expression = nodeFactory.createNode<IndexAccess>(expression, index.first);
}
return expression;
}
void Parser::expectToken(Token::Value _value)
{
if (m_scanner->getCurrentToken() != _value)
BOOST_THROW_EXCEPTION(createParserError(string("Expected token ") + 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 = make_shared<ASTString>(m_scanner->getCurrentLiteral());
m_scanner->next();
return identifier;
}
ASTPointer<ParameterList> Parser::createEmptyParameterList()
{
ASTNodeFactory nodeFactory(*this);
nodeFactory.setLocationEmpty();
return nodeFactory.createNode<ParameterList>(vector<ASTPointer<VariableDeclaration>>());
}
ParserError Parser::createParserError(string const& _description) const
{
return ParserError() << errinfo_sourceLocation(SourceLocation(getPosition(), getPosition(), getSourceName()))
<< errinfo_comment(_description);
}
}
}