00b61a212f
Giving the lexer the ability to generate errors adds unnecessary
complexity - also it only calls its syntax_error() function in one place
anyway ("unterminated string literal"). But since the lexer *also* emits
tokens like Eof or UnterminatedStringLiteral, it should be up to the
consumer of these tokens to decide what to do.
Also remove the option to not print errors to stderr as that's not
relevant anymore.
472 lines
17 KiB
C++
472 lines
17 KiB
C++
/*
|
|
* Copyright (c) 2020, Stephan Unverwerth <s.unverwerth@gmx.de>
|
|
* All rights reserved.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions are met:
|
|
*
|
|
* 1. Redistributions of source code must retain the above copyright notice, this
|
|
* list of conditions and the following disclaimer.
|
|
*
|
|
* 2. Redistributions in binary form must reproduce the above copyright notice,
|
|
* this list of conditions and the following disclaimer in the documentation
|
|
* and/or other materials provided with the distribution.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
|
|
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
|
|
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
|
|
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
|
|
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
|
|
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
|
|
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
|
|
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
|
*/
|
|
|
|
#include "Lexer.h"
|
|
#include <AK/HashMap.h>
|
|
#include <AK/StringBuilder.h>
|
|
#include <ctype.h>
|
|
#include <stdio.h>
|
|
|
|
namespace JS {
|
|
|
|
HashMap<String, TokenType> Lexer::s_keywords;
|
|
HashMap<String, TokenType> Lexer::s_three_char_tokens;
|
|
HashMap<String, TokenType> Lexer::s_two_char_tokens;
|
|
HashMap<char, TokenType> Lexer::s_single_char_tokens;
|
|
|
|
Lexer::Lexer(StringView source)
|
|
: m_source(source)
|
|
, m_current_token(TokenType::Eof, StringView(nullptr), StringView(nullptr), 0, 0)
|
|
{
|
|
if (s_keywords.is_empty()) {
|
|
s_keywords.set("await", TokenType::Await);
|
|
s_keywords.set("break", TokenType::Break);
|
|
s_keywords.set("case", TokenType::Case);
|
|
s_keywords.set("catch", TokenType::Catch);
|
|
s_keywords.set("class", TokenType::Class);
|
|
s_keywords.set("const", TokenType::Const);
|
|
s_keywords.set("continue", TokenType::Continue);
|
|
s_keywords.set("debugger", TokenType::Debugger);
|
|
s_keywords.set("default", TokenType::Default);
|
|
s_keywords.set("delete", TokenType::Delete);
|
|
s_keywords.set("do", TokenType::Do);
|
|
s_keywords.set("else", TokenType::Else);
|
|
s_keywords.set("enum", TokenType::Enum);
|
|
s_keywords.set("export", TokenType::Export);
|
|
s_keywords.set("extends", TokenType::Extends);
|
|
s_keywords.set("false", TokenType::BoolLiteral);
|
|
s_keywords.set("finally", TokenType::Finally);
|
|
s_keywords.set("for", TokenType::For);
|
|
s_keywords.set("function", TokenType::Function);
|
|
s_keywords.set("if", TokenType::If);
|
|
s_keywords.set("import", TokenType::Import);
|
|
s_keywords.set("in", TokenType::In);
|
|
s_keywords.set("instanceof", TokenType::Instanceof);
|
|
s_keywords.set("let", TokenType::Let);
|
|
s_keywords.set("new", TokenType::New);
|
|
s_keywords.set("null", TokenType::NullLiteral);
|
|
s_keywords.set("return", TokenType::Return);
|
|
s_keywords.set("super", TokenType::Super);
|
|
s_keywords.set("switch", TokenType::Switch);
|
|
s_keywords.set("this", TokenType::This);
|
|
s_keywords.set("throw", TokenType::Throw);
|
|
s_keywords.set("true", TokenType::BoolLiteral);
|
|
s_keywords.set("try", TokenType::Try);
|
|
s_keywords.set("typeof", TokenType::Typeof);
|
|
s_keywords.set("var", TokenType::Var);
|
|
s_keywords.set("void", TokenType::Void);
|
|
s_keywords.set("while", TokenType::While);
|
|
s_keywords.set("with", TokenType::With);
|
|
s_keywords.set("yield", TokenType::Yield);
|
|
}
|
|
|
|
if (s_three_char_tokens.is_empty()) {
|
|
s_three_char_tokens.set("===", TokenType::EqualsEqualsEquals);
|
|
s_three_char_tokens.set("!==", TokenType::ExclamationMarkEqualsEquals);
|
|
s_three_char_tokens.set("**=", TokenType::DoubleAsteriskEquals);
|
|
s_three_char_tokens.set("<<=", TokenType::ShiftLeftEquals);
|
|
s_three_char_tokens.set(">>=", TokenType::ShiftRightEquals);
|
|
s_three_char_tokens.set(">>>", TokenType::UnsignedShiftRight);
|
|
s_three_char_tokens.set("...", TokenType::TripleDot);
|
|
}
|
|
|
|
if (s_two_char_tokens.is_empty()) {
|
|
s_two_char_tokens.set("=>", TokenType::Arrow);
|
|
s_two_char_tokens.set("+=", TokenType::PlusEquals);
|
|
s_two_char_tokens.set("-=", TokenType::MinusEquals);
|
|
s_two_char_tokens.set("*=", TokenType::AsteriskEquals);
|
|
s_two_char_tokens.set("/=", TokenType::SlashEquals);
|
|
s_two_char_tokens.set("%=", TokenType::PercentEquals);
|
|
s_two_char_tokens.set("&=", TokenType::AmpersandEquals);
|
|
s_two_char_tokens.set("|=", TokenType::PipeEquals);
|
|
s_two_char_tokens.set("^=", TokenType::CaretEquals);
|
|
s_two_char_tokens.set("&&", TokenType::DoubleAmpersand);
|
|
s_two_char_tokens.set("||", TokenType::DoublePipe);
|
|
s_two_char_tokens.set("??", TokenType::DoubleQuestionMark);
|
|
s_two_char_tokens.set("**", TokenType::DoubleAsterisk);
|
|
s_two_char_tokens.set("==", TokenType::EqualsEquals);
|
|
s_two_char_tokens.set("<=", TokenType::LessThanEquals);
|
|
s_two_char_tokens.set(">=", TokenType::GreaterThanEquals);
|
|
s_two_char_tokens.set("!=", TokenType::ExclamationMarkEquals);
|
|
s_two_char_tokens.set("--", TokenType::MinusMinus);
|
|
s_two_char_tokens.set("++", TokenType::PlusPlus);
|
|
s_two_char_tokens.set("<<", TokenType::ShiftLeft);
|
|
s_two_char_tokens.set(">>", TokenType::ShiftRight);
|
|
s_two_char_tokens.set("?.", TokenType::QuestionMarkPeriod);
|
|
}
|
|
|
|
if (s_single_char_tokens.is_empty()) {
|
|
s_single_char_tokens.set('&', TokenType::Ampersand);
|
|
s_single_char_tokens.set('*', TokenType::Asterisk);
|
|
s_single_char_tokens.set('[', TokenType::BracketOpen);
|
|
s_single_char_tokens.set(']', TokenType::BracketClose);
|
|
s_single_char_tokens.set('^', TokenType::Caret);
|
|
s_single_char_tokens.set(':', TokenType::Colon);
|
|
s_single_char_tokens.set(',', TokenType::Comma);
|
|
s_single_char_tokens.set('{', TokenType::CurlyOpen);
|
|
s_single_char_tokens.set('}', TokenType::CurlyClose);
|
|
s_single_char_tokens.set('=', TokenType::Equals);
|
|
s_single_char_tokens.set('!', TokenType::ExclamationMark);
|
|
s_single_char_tokens.set('-', TokenType::Minus);
|
|
s_single_char_tokens.set('(', TokenType::ParenOpen);
|
|
s_single_char_tokens.set(')', TokenType::ParenClose);
|
|
s_single_char_tokens.set('%', TokenType::Percent);
|
|
s_single_char_tokens.set('.', TokenType::Period);
|
|
s_single_char_tokens.set('|', TokenType::Pipe);
|
|
s_single_char_tokens.set('+', TokenType::Plus);
|
|
s_single_char_tokens.set('?', TokenType::QuestionMark);
|
|
s_single_char_tokens.set(';', TokenType::Semicolon);
|
|
s_single_char_tokens.set('/', TokenType::Slash);
|
|
s_single_char_tokens.set('~', TokenType::Tilde);
|
|
s_single_char_tokens.set('<', TokenType::LessThan);
|
|
s_single_char_tokens.set('>', TokenType::GreaterThan);
|
|
}
|
|
consume();
|
|
}
|
|
|
|
void Lexer::consume()
|
|
{
|
|
if (m_position >= m_source.length()) {
|
|
m_position = m_source.length() + 1;
|
|
m_current_char = EOF;
|
|
return;
|
|
}
|
|
|
|
if (m_current_char == '\n') {
|
|
m_line_number++;
|
|
m_line_column = 1;
|
|
} else {
|
|
m_line_column++;
|
|
}
|
|
|
|
m_current_char = m_source[m_position++];
|
|
}
|
|
|
|
void Lexer::consume_exponent()
|
|
{
|
|
consume();
|
|
if (m_current_char == '-' || m_current_char == '+')
|
|
consume();
|
|
while (isdigit(m_current_char)) {
|
|
consume();
|
|
}
|
|
}
|
|
|
|
bool Lexer::match(char a, char b) const
|
|
{
|
|
if (m_position >= m_source.length())
|
|
return false;
|
|
|
|
return m_current_char == a
|
|
&& m_source[m_position] == b;
|
|
}
|
|
|
|
bool Lexer::match(char a, char b, char c) const
|
|
{
|
|
if (m_position + 1 >= m_source.length())
|
|
return false;
|
|
|
|
return m_current_char == a
|
|
&& m_source[m_position] == b
|
|
&& m_source[m_position + 1] == c;
|
|
}
|
|
|
|
bool Lexer::match(char a, char b, char c, char d) const
|
|
{
|
|
if (m_position + 2 >= m_source.length())
|
|
return false;
|
|
|
|
return m_current_char == a
|
|
&& m_source[m_position] == b
|
|
&& m_source[m_position + 1] == c
|
|
&& m_source[m_position + 2] == d;
|
|
}
|
|
|
|
bool Lexer::is_eof() const
|
|
{
|
|
return m_current_char == EOF;
|
|
}
|
|
|
|
bool Lexer::is_identifier_start() const
|
|
{
|
|
return isalpha(m_current_char) || m_current_char == '_' || m_current_char == '$';
|
|
}
|
|
|
|
bool Lexer::is_identifier_middle() const
|
|
{
|
|
return is_identifier_start() || isdigit(m_current_char);
|
|
}
|
|
|
|
bool Lexer::is_line_comment_start() const
|
|
{
|
|
return match('/', '/') || match('<', '!', '-', '-') || match('-', '-', '>');
|
|
}
|
|
|
|
bool Lexer::is_block_comment_start() const
|
|
{
|
|
return match('/', '*');
|
|
}
|
|
|
|
bool Lexer::is_block_comment_end() const
|
|
{
|
|
return match('*', '/');
|
|
}
|
|
|
|
bool Lexer::is_numeric_literal_start() const
|
|
{
|
|
return isdigit(m_current_char) || (m_current_char == '.' && m_position < m_source.length() && isdigit(m_source[m_position]));
|
|
}
|
|
|
|
Token Lexer::next()
|
|
{
|
|
size_t trivia_start = m_position;
|
|
auto in_template = !m_template_states.is_empty();
|
|
|
|
if (!in_template || m_template_states.last().in_expr) {
|
|
// consume whitespace and comments
|
|
while (true) {
|
|
if (isspace(m_current_char)) {
|
|
do {
|
|
consume();
|
|
} while (isspace(m_current_char));
|
|
} else if (is_line_comment_start()) {
|
|
consume();
|
|
do {
|
|
consume();
|
|
} while (!is_eof() && m_current_char != '\n');
|
|
} else if (is_block_comment_start()) {
|
|
consume();
|
|
do {
|
|
consume();
|
|
} while (!is_eof() && !is_block_comment_end());
|
|
consume(); // consume *
|
|
consume(); // consume /
|
|
} else {
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
size_t value_start = m_position;
|
|
auto token_type = TokenType::Invalid;
|
|
|
|
if (m_current_char == '`') {
|
|
consume();
|
|
|
|
if (!in_template) {
|
|
token_type = TokenType::TemplateLiteralStart;
|
|
m_template_states.append({ false, 0 });
|
|
} else {
|
|
if (m_template_states.last().in_expr) {
|
|
m_template_states.append({ false, 0 });
|
|
token_type = TokenType::TemplateLiteralStart;
|
|
} else {
|
|
m_template_states.take_last();
|
|
token_type = TokenType::TemplateLiteralEnd;
|
|
}
|
|
}
|
|
} else if (in_template && m_template_states.last().in_expr && m_template_states.last().open_bracket_count == 0 && m_current_char == '}') {
|
|
consume();
|
|
token_type = TokenType::TemplateLiteralExprEnd;
|
|
m_template_states.last().in_expr = false;
|
|
} else if (in_template && !m_template_states.last().in_expr) {
|
|
if (is_eof()) {
|
|
token_type = TokenType::UnterminatedTemplateLiteral;
|
|
m_template_states.take_last();
|
|
} else if (match('$', '{')) {
|
|
token_type = TokenType::TemplateLiteralExprStart;
|
|
consume();
|
|
consume();
|
|
m_template_states.last().in_expr = true;
|
|
} else {
|
|
while (!match('$', '{') && m_current_char != '`' && !is_eof()) {
|
|
if (match('\\', '$') || match('\\', '`'))
|
|
consume();
|
|
consume();
|
|
}
|
|
|
|
token_type = TokenType::TemplateLiteralString;
|
|
}
|
|
} else if (is_identifier_start()) {
|
|
// identifier or keyword
|
|
do {
|
|
consume();
|
|
} while (is_identifier_middle());
|
|
|
|
StringView value = m_source.substring_view(value_start - 1, m_position - value_start);
|
|
auto it = s_keywords.find(value);
|
|
if (it == s_keywords.end()) {
|
|
token_type = TokenType::Identifier;
|
|
} else {
|
|
token_type = it->value;
|
|
}
|
|
} else if (is_numeric_literal_start()) {
|
|
if (m_current_char == '0') {
|
|
consume();
|
|
if (m_current_char == '.') {
|
|
// decimal
|
|
consume();
|
|
while (isdigit(m_current_char)) {
|
|
consume();
|
|
}
|
|
if (m_current_char == 'e' || m_current_char == 'E') {
|
|
consume_exponent();
|
|
}
|
|
} else if (m_current_char == 'e' || m_current_char == 'E') {
|
|
consume_exponent();
|
|
} else if (m_current_char == 'o' || m_current_char == 'O') {
|
|
// octal
|
|
consume();
|
|
while (m_current_char >= '0' && m_current_char <= '7') {
|
|
consume();
|
|
}
|
|
} else if (m_current_char == 'b' || m_current_char == 'B') {
|
|
// binary
|
|
consume();
|
|
while (m_current_char == '0' || m_current_char == '1') {
|
|
consume();
|
|
}
|
|
} else if (m_current_char == 'x' || m_current_char == 'X') {
|
|
// hexadecimal
|
|
consume();
|
|
while (isxdigit(m_current_char)) {
|
|
consume();
|
|
}
|
|
} else if (isdigit(m_current_char)) {
|
|
// octal without 'O' prefix. Forbidden in 'strict mode'
|
|
// FIXME: We need to make sure this produces a syntax error when in strict mode
|
|
do {
|
|
consume();
|
|
} while (isdigit(m_current_char));
|
|
}
|
|
} else {
|
|
// 1...9 or period
|
|
while (isdigit(m_current_char)) {
|
|
consume();
|
|
}
|
|
if (m_current_char == '.') {
|
|
consume();
|
|
while (isdigit(m_current_char)) {
|
|
consume();
|
|
}
|
|
}
|
|
if (m_current_char == 'e' || m_current_char == 'E') {
|
|
consume_exponent();
|
|
}
|
|
}
|
|
token_type = TokenType::NumericLiteral;
|
|
} else if (m_current_char == '"' || m_current_char == '\'') {
|
|
char stop_char = m_current_char;
|
|
consume();
|
|
while (m_current_char != stop_char && m_current_char != '\n' && !is_eof()) {
|
|
if (m_current_char == '\\') {
|
|
consume();
|
|
}
|
|
consume();
|
|
}
|
|
if (m_current_char != stop_char) {
|
|
token_type = TokenType::UnterminatedStringLiteral;
|
|
} else {
|
|
consume();
|
|
token_type = TokenType::StringLiteral;
|
|
}
|
|
} else if (m_current_char == EOF) {
|
|
token_type = TokenType::Eof;
|
|
} else {
|
|
// There is only one four-char operator: >>>=
|
|
bool found_four_char_token = false;
|
|
if (match('>', '>', '>', '=')) {
|
|
found_four_char_token = true;
|
|
consume();
|
|
consume();
|
|
consume();
|
|
consume();
|
|
token_type = TokenType::UnsignedShiftRightEquals;
|
|
}
|
|
|
|
bool found_three_char_token = false;
|
|
if (!found_four_char_token && m_position + 1 < m_source.length()) {
|
|
char second_char = m_source[m_position];
|
|
char third_char = m_source[m_position + 1];
|
|
char three_chars[] { (char)m_current_char, second_char, third_char, 0 };
|
|
auto it = s_three_char_tokens.find(three_chars);
|
|
if (it != s_three_char_tokens.end()) {
|
|
found_three_char_token = true;
|
|
consume();
|
|
consume();
|
|
consume();
|
|
token_type = it->value;
|
|
}
|
|
}
|
|
|
|
bool found_two_char_token = false;
|
|
if (!found_four_char_token && !found_three_char_token && m_position < m_source.length()) {
|
|
char second_char = m_source[m_position];
|
|
char two_chars[] { (char)m_current_char, second_char, 0 };
|
|
auto it = s_two_char_tokens.find(two_chars);
|
|
if (it != s_two_char_tokens.end()) {
|
|
found_two_char_token = true;
|
|
consume();
|
|
consume();
|
|
token_type = it->value;
|
|
}
|
|
}
|
|
|
|
bool found_one_char_token = false;
|
|
if (!found_four_char_token && !found_three_char_token && !found_two_char_token) {
|
|
auto it = s_single_char_tokens.find(m_current_char);
|
|
if (it != s_single_char_tokens.end()) {
|
|
found_one_char_token = true;
|
|
consume();
|
|
token_type = it->value;
|
|
}
|
|
}
|
|
|
|
if (!found_four_char_token && !found_three_char_token && !found_two_char_token && !found_one_char_token) {
|
|
consume();
|
|
token_type = TokenType::Invalid;
|
|
}
|
|
}
|
|
|
|
if (!m_template_states.is_empty() && m_template_states.last().in_expr) {
|
|
if (token_type == TokenType::CurlyOpen) {
|
|
m_template_states.last().open_bracket_count++;
|
|
} else if (token_type == TokenType::CurlyClose) {
|
|
m_template_states.last().open_bracket_count--;
|
|
}
|
|
}
|
|
|
|
m_current_token = Token(
|
|
token_type,
|
|
m_source.substring_view(trivia_start - 1, value_start - trivia_start),
|
|
m_source.substring_view(value_start - 1, m_position - value_start),
|
|
m_line_number,
|
|
m_line_column - m_position + value_start);
|
|
|
|
return m_current_token;
|
|
}
|
|
|
|
}
|