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// modification, are permitted provided that the following conditions are
// met:
//
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// copyright notice, this list of conditions and the following
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// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
//
// Modifications as part of cpp-ethereum under the following license:
//
// 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/>.
#pragma once
#include <boost/assert.hpp>
#include <libdevcore/Common.h>
#include <libdevcore/Log.h>
#include <libdevcore/CommonData.h>
#include <libsolidity/BaseTypes.h>
#include <libsolidity/Token.h>
namespace dev
{
namespace solidity
{
class AstRawString;
class AstValueFactory;
class ParserRecorder;
class CharStream
{
public:
CharStream()
: m_pos(0)
{}
explicit CharStream(const std::string& _source) : m_source(_source), m_pos(0) {}
int getPos() const { return m_pos; }
bool isPastEndOfInput() const { return m_pos >= m_source.size(); }
char get() const { return m_source[m_pos]; }
char advanceAndGet()
{
if (isPastEndOfInput()) return 0;
++m_pos;
if (isPastEndOfInput()) return 0;
return get();
}
char rollback(size_t _amount)
{
BOOST_ASSERT(m_pos >= _amount);
m_pos -= _amount;
return get();
}
/// Functions that help pretty-printing parse errors
/// Do only use in error cases, they are quite expensive.
/// @{
std::string getLineAtPosition(int _position) const;
std::tuple<int, int> translatePositionToLineColumn(int _position) const;
/// @}
private:
std::string m_source;
size_t m_pos;
};
// ----------------------------------------------------------------------------
// JavaScript Scanner.
class Scanner
{
public:
// Scoped helper for literal recording. Automatically drops the literal
// if aborting the scanning before it's complete.
class LiteralScope
{
public:
explicit LiteralScope(Scanner* self) : scanner_(self), complete_(false) { scanner_->startNewLiteral(); }
~LiteralScope() { if (!complete_) scanner_->dropLiteral(); }
void Complete() { complete_ = true; }
private:
Scanner* scanner_;
bool complete_;
};
explicit Scanner(const CharStream& _source);
// Resets the scanner as if newly constructed with _input as input.
void reset(const CharStream& _source);
// Returns the next token and advances input.
Token::Value next();
// Returns the current token again.
Token::Value getCurrentToken() { return m_current_token.token; }
// Returns the location information for the current token
// (the token last returned by Next()).
Location getCurrentLocation() const { return m_current_token.location; }
const std::string& getCurrentLiteral() const { return m_current_token.literal; }
// Similar functions for the upcoming token.
// One token look-ahead (past the token returned by Next()).
Token::Value peek() const { return m_next_token.token; }
Location peekLocation() const { return m_next_token.location; }
const std::string& peekLiteral() const { return m_next_token.literal; }
/// Functions that help pretty-printing parse errors.
/// Do only use in error cases, they are quite expensive.
/// @{
std::string getLineAtPosition(int _position) const
{
return m_source.getLineAtPosition(_position);
}
std::tuple<int, int> translatePositionToLineColumn(int _position) const
{
return m_source.translatePositionToLineColumn(_position);
}
/// @}
// Returns true if there was a line terminator before the peek'ed token,
// possibly inside a multi-line comment.
bool hasAnyLineTerminatorBeforeNext() const
{
return m_hasLineTerminatorBeforeNext ||
m_hasMultilineCommentBeforeNext;
}
private:
// Used for the current and look-ahead token.
struct TokenDesc
{
Token::Value token;
Location location;
std::string literal;
};
// Literal buffer support
inline void startNewLiteral() { m_next_token.literal.clear(); }
inline void addLiteralChar(char c) { m_next_token.literal.push_back(c); }
inline void dropLiteral() { m_next_token.literal.clear(); }
inline void addLiteralCharAndAdvance() { addLiteralChar(m_char); advance(); }
// Low-level scanning support.
bool advance() { m_char = m_source.advanceAndGet(); return !m_source.isPastEndOfInput(); }
void rollback(int amount) { m_char = m_source.rollback(amount); }
inline Token::Value selectToken(Token::Value tok) { advance(); return tok; }
inline Token::Value selectToken(char next, Token::Value then, Token::Value else_)
{
advance();
if (m_char == next)
{
advance();
return then;
}
else
return else_;
}
bool scanHexNumber(char& scanned_number, int expected_length);
// Scans a single JavaScript token.
void scanToken();
bool skipWhitespace();
Token::Value skipSingleLineComment();
Token::Value skipMultiLineComment();
void scanDecimalDigits();
Token::Value scanNumber(bool _periodSeen);
Token::Value scanIdentifierOrKeyword();
Token::Value scanString();
// Scans an escape-sequence which is part of a string and adds the
// decoded character to the current literal. Returns true if a pattern
// is scanned.
bool scanEscape();
// Return the current source position.
int getSourcePos() { return m_source.getPos(); }
bool isSourcePastEndOfInput() { return m_source.isPastEndOfInput(); }
TokenDesc m_current_token; // desc for current token (as returned by Next())
TokenDesc m_next_token; // desc for next token (one token look-ahead)
CharStream m_source;
// one character look-ahead, equals 0 at end of input
char m_char;
// Whether there is a line terminator whitespace character after
// the current token, and before the next. Does not count newlines
// inside multiline comments.
bool m_hasLineTerminatorBeforeNext;
// Whether there is a multi-line comment that contains a
// line-terminator after the current token, and before the next.
bool m_hasMultilineCommentBeforeNext;
};
}
}
