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1083 lines
31 KiB
1083 lines
31 KiB
// Copyright 2011 the V8 project authors. All rights reserved.
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// Redistribution and use in source and binary forms, with or without
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// modification, are permitted provided that the following conditions are
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// met:
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//
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// * Redistributions of source code must retain the above copyright
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// notice, this list of conditions and the following disclaimer.
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// * Redistributions in binary form must reproduce the above
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// copyright notice, this list of conditions and the following
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// disclaimer in the documentation and/or other materials provided
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// with the distribution.
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// * Neither the name of Google Inc. nor the names of its
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// contributors may be used to endorse or promote products derived
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// from this software without specific prior written permission.
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//
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// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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// Features shared by parsing and pre-parsing scanners.
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#include "scanner.h"
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#include "../include/v8stdint.h"
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#include "char-predicates-inl.h"
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namespace v8 {
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namespace internal {
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// ----------------------------------------------------------------------------
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// Scanner
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Scanner::Scanner(UnicodeCache* unicode_cache)
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: unicode_cache_(unicode_cache),
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octal_pos_(Location::invalid()),
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harmony_scoping_(false) { }
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void Scanner::Initialize(UC16CharacterStream* source) {
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source_ = source;
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// Need to capture identifiers in order to recognize "get" and "set"
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// in object literals.
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Init();
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// Skip initial whitespace allowing HTML comment ends just like
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// after a newline and scan first token.
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has_line_terminator_before_next_ = true;
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SkipWhiteSpace();
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Scan();
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}
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uc32 Scanner::ScanHexNumber(int expected_length) {
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ASSERT(expected_length <= 4); // prevent overflow
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uc32 digits[4] = { 0, 0, 0, 0 };
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uc32 x = 0;
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for (int i = 0; i < expected_length; i++) {
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digits[i] = c0_;
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int d = HexValue(c0_);
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if (d < 0) {
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// According to ECMA-262, 3rd, 7.8.4, page 18, these hex escapes
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// should be illegal, but other JS VMs just return the
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// non-escaped version of the original character.
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// Push back digits that we have advanced past.
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for (int j = i-1; j >= 0; j--) {
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PushBack(digits[j]);
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}
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return -1;
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}
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x = x * 16 + d;
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Advance();
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}
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return x;
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}
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// Ensure that tokens can be stored in a byte.
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STATIC_ASSERT(Token::NUM_TOKENS <= 0x100);
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// Table of one-character tokens, by character (0x00..0x7f only).
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static const byte one_char_tokens[] = {
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::LPAREN, // 0x28
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Token::RPAREN, // 0x29
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::COMMA, // 0x2c
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::COLON, // 0x3a
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Token::SEMICOLON, // 0x3b
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::CONDITIONAL, // 0x3f
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::LBRACK, // 0x5b
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Token::ILLEGAL,
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Token::RBRACK, // 0x5d
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::ILLEGAL,
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Token::LBRACE, // 0x7b
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Token::ILLEGAL,
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Token::RBRACE, // 0x7d
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Token::BIT_NOT, // 0x7e
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Token::ILLEGAL
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};
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Token::Value Scanner::Next() {
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current_ = next_;
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has_line_terminator_before_next_ = false;
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has_multiline_comment_before_next_ = false;
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if (static_cast<unsigned>(c0_) <= 0x7f) {
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Token::Value token = static_cast<Token::Value>(one_char_tokens[c0_]);
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if (token != Token::ILLEGAL) {
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int pos = source_pos();
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next_.token = token;
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next_.location.beg_pos = pos;
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next_.location.end_pos = pos + 1;
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Advance();
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return current_.token;
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}
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}
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Scan();
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return current_.token;
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}
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static inline bool IsByteOrderMark(uc32 c) {
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// The Unicode value U+FFFE is guaranteed never to be assigned as a
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// Unicode character; this implies that in a Unicode context the
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// 0xFF, 0xFE byte pattern can only be interpreted as the U+FEFF
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// character expressed in little-endian byte order (since it could
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// not be a U+FFFE character expressed in big-endian byte
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// order). Nevertheless, we check for it to be compatible with
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// Spidermonkey.
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return c == 0xFEFF || c == 0xFFFE;
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}
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bool Scanner::SkipWhiteSpace() {
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int start_position = source_pos();
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while (true) {
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// We treat byte-order marks (BOMs) as whitespace for better
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// compatibility with Spidermonkey and other JavaScript engines.
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while (unicode_cache_->IsWhiteSpace(c0_) || IsByteOrderMark(c0_)) {
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// IsWhiteSpace() includes line terminators!
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if (unicode_cache_->IsLineTerminator(c0_)) {
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// Ignore line terminators, but remember them. This is necessary
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// for automatic semicolon insertion.
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has_line_terminator_before_next_ = true;
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}
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Advance();
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}
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// If there is an HTML comment end '-->' at the beginning of a
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// line (with only whitespace in front of it), we treat the rest
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// of the line as a comment. This is in line with the way
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// SpiderMonkey handles it.
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if (c0_ == '-' && has_line_terminator_before_next_) {
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Advance();
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if (c0_ == '-') {
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Advance();
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if (c0_ == '>') {
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// Treat the rest of the line as a comment.
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SkipSingleLineComment();
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// Continue skipping white space after the comment.
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continue;
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}
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PushBack('-'); // undo Advance()
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}
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PushBack('-'); // undo Advance()
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}
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// Return whether or not we skipped any characters.
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return source_pos() != start_position;
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}
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}
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Token::Value Scanner::SkipSingleLineComment() {
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Advance();
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// The line terminator at the end of the line is not considered
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// to be part of the single-line comment; it is recognized
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// separately by the lexical grammar and becomes part of the
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// stream of input elements for the syntactic grammar (see
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// ECMA-262, section 7.4).
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while (c0_ >= 0 && !unicode_cache_->IsLineTerminator(c0_)) {
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Advance();
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}
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return Token::WHITESPACE;
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}
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Token::Value Scanner::SkipMultiLineComment() {
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ASSERT(c0_ == '*');
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Advance();
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while (c0_ >= 0) {
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uc32 ch = c0_;
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Advance();
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if (unicode_cache_->IsLineTerminator(ch)) {
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// Following ECMA-262, section 7.4, a comment containing
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// a newline will make the comment count as a line-terminator.
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has_multiline_comment_before_next_ = true;
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}
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// If we have reached the end of the multi-line comment, we
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// consume the '/' and insert a whitespace. This way all
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// multi-line comments are treated as whitespace.
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if (ch == '*' && c0_ == '/') {
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c0_ = ' ';
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return Token::WHITESPACE;
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}
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}
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// Unterminated multi-line comment.
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return Token::ILLEGAL;
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}
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Token::Value Scanner::ScanHtmlComment() {
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// Check for <!-- comments.
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ASSERT(c0_ == '!');
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Advance();
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if (c0_ == '-') {
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Advance();
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if (c0_ == '-') return SkipSingleLineComment();
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PushBack('-'); // undo Advance()
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}
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PushBack('!'); // undo Advance()
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ASSERT(c0_ == '!');
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return Token::LT;
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}
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void Scanner::Scan() {
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next_.literal_chars = NULL;
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Token::Value token;
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do {
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// Remember the position of the next token
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next_.location.beg_pos = source_pos();
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switch (c0_) {
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case ' ':
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case '\t':
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Advance();
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token = Token::WHITESPACE;
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break;
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case '\n':
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Advance();
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has_line_terminator_before_next_ = true;
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token = Token::WHITESPACE;
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break;
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case '"': case '\'':
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token = ScanString();
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break;
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case '<':
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// < <= << <<= <!--
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Advance();
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if (c0_ == '=') {
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token = Select(Token::LTE);
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} else if (c0_ == '<') {
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token = Select('=', Token::ASSIGN_SHL, Token::SHL);
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} else if (c0_ == '!') {
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token = ScanHtmlComment();
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} else {
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token = Token::LT;
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}
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break;
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case '>':
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// > >= >> >>= >>> >>>=
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Advance();
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if (c0_ == '=') {
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token = Select(Token::GTE);
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} else if (c0_ == '>') {
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// >> >>= >>> >>>=
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Advance();
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if (c0_ == '=') {
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token = Select(Token::ASSIGN_SAR);
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} else if (c0_ == '>') {
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token = Select('=', Token::ASSIGN_SHR, Token::SHR);
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} else {
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token = Token::SAR;
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}
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} else {
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token = Token::GT;
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}
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break;
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case '=':
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// = == ===
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Advance();
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if (c0_ == '=') {
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token = Select('=', Token::EQ_STRICT, Token::EQ);
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} else {
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token = Token::ASSIGN;
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}
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break;
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case '!':
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// ! != !==
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Advance();
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if (c0_ == '=') {
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token = Select('=', Token::NE_STRICT, Token::NE);
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} else {
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token = Token::NOT;
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}
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break;
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case '+':
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// + ++ +=
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Advance();
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if (c0_ == '+') {
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token = Select(Token::INC);
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} else if (c0_ == '=') {
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token = Select(Token::ASSIGN_ADD);
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} else {
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token = Token::ADD;
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}
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break;
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case '-':
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// - -- --> -=
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Advance();
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if (c0_ == '-') {
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Advance();
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if (c0_ == '>' && has_line_terminator_before_next_) {
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// For compatibility with SpiderMonkey, we skip lines that
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// start with an HTML comment end '-->'.
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token = SkipSingleLineComment();
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} else {
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token = Token::DEC;
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}
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} else if (c0_ == '=') {
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token = Select(Token::ASSIGN_SUB);
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} else {
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token = Token::SUB;
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}
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break;
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case '*':
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// * *=
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token = Select('=', Token::ASSIGN_MUL, Token::MUL);
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break;
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case '%':
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// % %=
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token = Select('=', Token::ASSIGN_MOD, Token::MOD);
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break;
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case '/':
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|
// / // /* /=
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Advance();
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if (c0_ == '/') {
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|
token = SkipSingleLineComment();
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|
} else if (c0_ == '*') {
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|
token = SkipMultiLineComment();
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|
} else if (c0_ == '=') {
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|
token = Select(Token::ASSIGN_DIV);
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|
} else {
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token = Token::DIV;
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|
}
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|
break;
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|
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case '&':
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|
// & && &=
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Advance();
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if (c0_ == '&') {
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|
token = Select(Token::AND);
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|
} else if (c0_ == '=') {
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|
token = Select(Token::ASSIGN_BIT_AND);
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|
} else {
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token = Token::BIT_AND;
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|
}
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|
break;
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|
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case '|':
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|
// | || |=
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|
Advance();
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if (c0_ == '|') {
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|
token = Select(Token::OR);
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|
} else if (c0_ == '=') {
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|
token = Select(Token::ASSIGN_BIT_OR);
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|
} else {
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|
token = Token::BIT_OR;
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|
}
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|
break;
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|
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|
case '^':
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|
// ^ ^=
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|
token = Select('=', Token::ASSIGN_BIT_XOR, Token::BIT_XOR);
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|
break;
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|
|
|
case '.':
|
|
// . Number
|
|
Advance();
|
|
if (IsDecimalDigit(c0_)) {
|
|
token = ScanNumber(true);
|
|
} else {
|
|
token = Token::PERIOD;
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|
}
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|
break;
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|
case ':':
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token = Select(Token::COLON);
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|
break;
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case ';':
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|
token = Select(Token::SEMICOLON);
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|
break;
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|
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|
case ',':
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|
token = Select(Token::COMMA);
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|
break;
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|
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|
case '(':
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|
token = Select(Token::LPAREN);
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|
break;
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|
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|
case ')':
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|
token = Select(Token::RPAREN);
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|
break;
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|
case '[':
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|
token = Select(Token::LBRACK);
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|
break;
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|
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|
case ']':
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|
token = Select(Token::RBRACK);
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|
break;
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|
|
|
case '{':
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|
token = Select(Token::LBRACE);
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|
break;
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|
case '}':
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|
token = Select(Token::RBRACE);
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|
break;
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|
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|
case '?':
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|
token = Select(Token::CONDITIONAL);
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|
break;
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|
|
|
case '~':
|
|
token = Select(Token::BIT_NOT);
|
|
break;
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|
|
|
default:
|
|
if (unicode_cache_->IsIdentifierStart(c0_)) {
|
|
token = ScanIdentifierOrKeyword();
|
|
} else if (IsDecimalDigit(c0_)) {
|
|
token = ScanNumber(false);
|
|
} else if (SkipWhiteSpace()) {
|
|
token = Token::WHITESPACE;
|
|
} else if (c0_ < 0) {
|
|
token = Token::EOS;
|
|
} else {
|
|
token = Select(Token::ILLEGAL);
|
|
}
|
|
break;
|
|
}
|
|
|
|
// Continue scanning for tokens as long as we're just skipping
|
|
// whitespace.
|
|
} while (token == Token::WHITESPACE);
|
|
|
|
next_.location.end_pos = source_pos();
|
|
next_.token = token;
|
|
}
|
|
|
|
|
|
void Scanner::SeekForward(int pos) {
|
|
// After this call, we will have the token at the given position as
|
|
// the "next" token. The "current" token will be invalid.
|
|
if (pos == next_.location.beg_pos) return;
|
|
int current_pos = source_pos();
|
|
ASSERT_EQ(next_.location.end_pos, current_pos);
|
|
// Positions inside the lookahead token aren't supported.
|
|
ASSERT(pos >= current_pos);
|
|
if (pos != current_pos) {
|
|
source_->SeekForward(pos - source_->pos());
|
|
Advance();
|
|
// This function is only called to seek to the location
|
|
// of the end of a function (at the "}" token). It doesn't matter
|
|
// whether there was a line terminator in the part we skip.
|
|
has_line_terminator_before_next_ = false;
|
|
has_multiline_comment_before_next_ = false;
|
|
}
|
|
Scan();
|
|
}
|
|
|
|
|
|
void Scanner::ScanEscape() {
|
|
uc32 c = c0_;
|
|
Advance();
|
|
|
|
// Skip escaped newlines.
|
|
if (unicode_cache_->IsLineTerminator(c)) {
|
|
// Allow CR+LF newlines in multiline string literals.
|
|
if (IsCarriageReturn(c) && IsLineFeed(c0_)) Advance();
|
|
// Allow LF+CR newlines in multiline string literals.
|
|
if (IsLineFeed(c) && IsCarriageReturn(c0_)) Advance();
|
|
return;
|
|
}
|
|
|
|
switch (c) {
|
|
case '\'': // fall through
|
|
case '"' : // fall through
|
|
case '\\': break;
|
|
case 'b' : c = '\b'; break;
|
|
case 'f' : c = '\f'; break;
|
|
case 'n' : c = '\n'; break;
|
|
case 'r' : c = '\r'; break;
|
|
case 't' : c = '\t'; break;
|
|
case 'u' : {
|
|
c = ScanHexNumber(4);
|
|
if (c < 0) c = 'u';
|
|
break;
|
|
}
|
|
case 'v' : c = '\v'; break;
|
|
case 'x' : {
|
|
c = ScanHexNumber(2);
|
|
if (c < 0) c = 'x';
|
|
break;
|
|
}
|
|
case '0' : // fall through
|
|
case '1' : // fall through
|
|
case '2' : // fall through
|
|
case '3' : // fall through
|
|
case '4' : // fall through
|
|
case '5' : // fall through
|
|
case '6' : // fall through
|
|
case '7' : c = ScanOctalEscape(c, 2); break;
|
|
}
|
|
|
|
// According to ECMA-262, 3rd, 7.8.4 (p 18ff) these
|
|
// should be illegal, but they are commonly handled
|
|
// as non-escaped characters by JS VMs.
|
|
AddLiteralChar(c);
|
|
}
|
|
|
|
|
|
// Octal escapes of the forms '\0xx' and '\xxx' are not a part of
|
|
// ECMA-262. Other JS VMs support them.
|
|
uc32 Scanner::ScanOctalEscape(uc32 c, int length) {
|
|
uc32 x = c - '0';
|
|
int i = 0;
|
|
for (; i < length; i++) {
|
|
int d = c0_ - '0';
|
|
if (d < 0 || d > 7) break;
|
|
int nx = x * 8 + d;
|
|
if (nx >= 256) break;
|
|
x = nx;
|
|
Advance();
|
|
}
|
|
// Anything except '\0' is an octal escape sequence, illegal in strict mode.
|
|
// Remember the position of octal escape sequences so that an error
|
|
// can be reported later (in strict mode).
|
|
// We don't report the error immediately, because the octal escape can
|
|
// occur before the "use strict" directive.
|
|
if (c != '0' || i > 0) {
|
|
octal_pos_ = Location(source_pos() - i - 1, source_pos() - 1);
|
|
}
|
|
return x;
|
|
}
|
|
|
|
|
|
Token::Value Scanner::ScanString() {
|
|
uc32 quote = c0_;
|
|
Advance(); // consume quote
|
|
|
|
LiteralScope literal(this);
|
|
while (c0_ != quote && c0_ >= 0
|
|
&& !unicode_cache_->IsLineTerminator(c0_)) {
|
|
uc32 c = c0_;
|
|
Advance();
|
|
if (c == '\\') {
|
|
if (c0_ < 0) return Token::ILLEGAL;
|
|
ScanEscape();
|
|
} else {
|
|
AddLiteralChar(c);
|
|
}
|
|
}
|
|
if (c0_ != quote) return Token::ILLEGAL;
|
|
literal.Complete();
|
|
|
|
Advance(); // consume quote
|
|
return Token::STRING;
|
|
}
|
|
|
|
|
|
void Scanner::ScanDecimalDigits() {
|
|
while (IsDecimalDigit(c0_))
|
|
AddLiteralCharAdvance();
|
|
}
|
|
|
|
|
|
Token::Value Scanner::ScanNumber(bool seen_period) {
|
|
ASSERT(IsDecimalDigit(c0_)); // the first digit of the number or the fraction
|
|
|
|
enum { DECIMAL, HEX, OCTAL } kind = DECIMAL;
|
|
|
|
LiteralScope literal(this);
|
|
if (seen_period) {
|
|
// we have already seen a decimal point of the float
|
|
AddLiteralChar('.');
|
|
ScanDecimalDigits(); // we know we have at least one digit
|
|
|
|
} else {
|
|
// if the first character is '0' we must check for octals and hex
|
|
if (c0_ == '0') {
|
|
int start_pos = source_pos(); // For reporting octal positions.
|
|
AddLiteralCharAdvance();
|
|
|
|
// either 0, 0exxx, 0Exxx, 0.xxx, an octal number, or a hex number
|
|
if (c0_ == 'x' || c0_ == 'X') {
|
|
// hex number
|
|
kind = HEX;
|
|
AddLiteralCharAdvance();
|
|
if (!IsHexDigit(c0_)) {
|
|
// we must have at least one hex digit after 'x'/'X'
|
|
return Token::ILLEGAL;
|
|
}
|
|
while (IsHexDigit(c0_)) {
|
|
AddLiteralCharAdvance();
|
|
}
|
|
} else if ('0' <= c0_ && c0_ <= '7') {
|
|
// (possible) octal number
|
|
kind = OCTAL;
|
|
while (true) {
|
|
if (c0_ == '8' || c0_ == '9') {
|
|
kind = DECIMAL;
|
|
break;
|
|
}
|
|
if (c0_ < '0' || '7' < c0_) {
|
|
// Octal literal finished.
|
|
octal_pos_ = Location(start_pos, source_pos());
|
|
break;
|
|
}
|
|
AddLiteralCharAdvance();
|
|
}
|
|
}
|
|
}
|
|
|
|
// Parse decimal digits and allow trailing fractional part.
|
|
if (kind == DECIMAL) {
|
|
ScanDecimalDigits(); // optional
|
|
if (c0_ == '.') {
|
|
AddLiteralCharAdvance();
|
|
ScanDecimalDigits(); // optional
|
|
}
|
|
}
|
|
}
|
|
|
|
// scan exponent, if any
|
|
if (c0_ == 'e' || c0_ == 'E') {
|
|
ASSERT(kind != HEX); // 'e'/'E' must be scanned as part of the hex number
|
|
if (kind == OCTAL) return Token::ILLEGAL; // no exponent for octals allowed
|
|
// scan exponent
|
|
AddLiteralCharAdvance();
|
|
if (c0_ == '+' || c0_ == '-')
|
|
AddLiteralCharAdvance();
|
|
if (!IsDecimalDigit(c0_)) {
|
|
// we must have at least one decimal digit after 'e'/'E'
|
|
return Token::ILLEGAL;
|
|
}
|
|
ScanDecimalDigits();
|
|
}
|
|
|
|
// The source character immediately following a numeric literal must
|
|
// not be an identifier start or a decimal digit; see ECMA-262
|
|
// section 7.8.3, page 17 (note that we read only one decimal digit
|
|
// if the value is 0).
|
|
if (IsDecimalDigit(c0_) || unicode_cache_->IsIdentifierStart(c0_))
|
|
return Token::ILLEGAL;
|
|
|
|
literal.Complete();
|
|
|
|
return Token::NUMBER;
|
|
}
|
|
|
|
|
|
uc32 Scanner::ScanIdentifierUnicodeEscape() {
|
|
Advance();
|
|
if (c0_ != 'u') return -1;
|
|
Advance();
|
|
uc32 result = ScanHexNumber(4);
|
|
if (result < 0) PushBack('u');
|
|
return result;
|
|
}
|
|
|
|
|
|
// ----------------------------------------------------------------------------
|
|
// Keyword Matcher
|
|
|
|
#define KEYWORDS(KEYWORD_GROUP, KEYWORD) \
|
|
KEYWORD_GROUP('b') \
|
|
KEYWORD("break", Token::BREAK) \
|
|
KEYWORD_GROUP('c') \
|
|
KEYWORD("case", Token::CASE) \
|
|
KEYWORD("catch", Token::CATCH) \
|
|
KEYWORD("class", Token::FUTURE_RESERVED_WORD) \
|
|
KEYWORD("const", Token::CONST) \
|
|
KEYWORD("continue", Token::CONTINUE) \
|
|
KEYWORD_GROUP('d') \
|
|
KEYWORD("debugger", Token::DEBUGGER) \
|
|
KEYWORD("default", Token::DEFAULT) \
|
|
KEYWORD("delete", Token::DELETE) \
|
|
KEYWORD("do", Token::DO) \
|
|
KEYWORD_GROUP('e') \
|
|
KEYWORD("else", Token::ELSE) \
|
|
KEYWORD("enum", Token::FUTURE_RESERVED_WORD) \
|
|
KEYWORD("export", Token::FUTURE_RESERVED_WORD) \
|
|
KEYWORD("extends", Token::FUTURE_RESERVED_WORD) \
|
|
KEYWORD_GROUP('f') \
|
|
KEYWORD("false", Token::FALSE_LITERAL) \
|
|
KEYWORD("finally", Token::FINALLY) \
|
|
KEYWORD("for", Token::FOR) \
|
|
KEYWORD("function", Token::FUNCTION) \
|
|
KEYWORD_GROUP('i') \
|
|
KEYWORD("if", Token::IF) \
|
|
KEYWORD("implements", Token::FUTURE_STRICT_RESERVED_WORD) \
|
|
KEYWORD("import", Token::FUTURE_RESERVED_WORD) \
|
|
KEYWORD("in", Token::IN) \
|
|
KEYWORD("instanceof", Token::INSTANCEOF) \
|
|
KEYWORD("interface", Token::FUTURE_STRICT_RESERVED_WORD) \
|
|
KEYWORD_GROUP('l') \
|
|
KEYWORD("let", harmony_scoping \
|
|
? Token::LET : Token::FUTURE_STRICT_RESERVED_WORD) \
|
|
KEYWORD_GROUP('n') \
|
|
KEYWORD("new", Token::NEW) \
|
|
KEYWORD("null", Token::NULL_LITERAL) \
|
|
KEYWORD_GROUP('p') \
|
|
KEYWORD("package", Token::FUTURE_STRICT_RESERVED_WORD) \
|
|
KEYWORD("private", Token::FUTURE_STRICT_RESERVED_WORD) \
|
|
KEYWORD("protected", Token::FUTURE_STRICT_RESERVED_WORD) \
|
|
KEYWORD("public", Token::FUTURE_STRICT_RESERVED_WORD) \
|
|
KEYWORD_GROUP('r') \
|
|
KEYWORD("return", Token::RETURN) \
|
|
KEYWORD_GROUP('s') \
|
|
KEYWORD("static", Token::FUTURE_STRICT_RESERVED_WORD) \
|
|
KEYWORD("super", Token::FUTURE_RESERVED_WORD) \
|
|
KEYWORD("switch", Token::SWITCH) \
|
|
KEYWORD_GROUP('t') \
|
|
KEYWORD("this", Token::THIS) \
|
|
KEYWORD("throw", Token::THROW) \
|
|
KEYWORD("true", Token::TRUE_LITERAL) \
|
|
KEYWORD("try", Token::TRY) \
|
|
KEYWORD("typeof", Token::TYPEOF) \
|
|
KEYWORD_GROUP('v') \
|
|
KEYWORD("var", Token::VAR) \
|
|
KEYWORD("void", Token::VOID) \
|
|
KEYWORD_GROUP('w') \
|
|
KEYWORD("while", Token::WHILE) \
|
|
KEYWORD("with", Token::WITH) \
|
|
KEYWORD_GROUP('y') \
|
|
KEYWORD("yield", Token::FUTURE_STRICT_RESERVED_WORD)
|
|
|
|
|
|
static Token::Value KeywordOrIdentifierToken(const char* input,
|
|
int input_length,
|
|
bool harmony_scoping) {
|
|
ASSERT(input_length >= 1);
|
|
const int kMinLength = 2;
|
|
const int kMaxLength = 10;
|
|
if (input_length < kMinLength || input_length > kMaxLength) {
|
|
return Token::IDENTIFIER;
|
|
}
|
|
switch (input[0]) {
|
|
default:
|
|
#define KEYWORD_GROUP_CASE(ch) \
|
|
break; \
|
|
case ch:
|
|
#define KEYWORD(keyword, token) \
|
|
{ \
|
|
/* 'keyword' is a char array, so sizeof(keyword) is */ \
|
|
/* strlen(keyword) plus 1 for the NUL char. */ \
|
|
const int keyword_length = sizeof(keyword) - 1; \
|
|
STATIC_ASSERT(keyword_length >= kMinLength); \
|
|
STATIC_ASSERT(keyword_length <= kMaxLength); \
|
|
if (input_length == keyword_length && \
|
|
input[1] == keyword[1] && \
|
|
(keyword_length <= 2 || input[2] == keyword[2]) && \
|
|
(keyword_length <= 3 || input[3] == keyword[3]) && \
|
|
(keyword_length <= 4 || input[4] == keyword[4]) && \
|
|
(keyword_length <= 5 || input[5] == keyword[5]) && \
|
|
(keyword_length <= 6 || input[6] == keyword[6]) && \
|
|
(keyword_length <= 7 || input[7] == keyword[7]) && \
|
|
(keyword_length <= 8 || input[8] == keyword[8]) && \
|
|
(keyword_length <= 9 || input[9] == keyword[9])) { \
|
|
return token; \
|
|
} \
|
|
}
|
|
KEYWORDS(KEYWORD_GROUP_CASE, KEYWORD)
|
|
}
|
|
return Token::IDENTIFIER;
|
|
}
|
|
|
|
|
|
Token::Value Scanner::ScanIdentifierOrKeyword() {
|
|
ASSERT(unicode_cache_->IsIdentifierStart(c0_));
|
|
LiteralScope literal(this);
|
|
// Scan identifier start character.
|
|
if (c0_ == '\\') {
|
|
uc32 c = ScanIdentifierUnicodeEscape();
|
|
// Only allow legal identifier start characters.
|
|
if (c < 0 ||
|
|
c == '\\' || // No recursive escapes.
|
|
!unicode_cache_->IsIdentifierStart(c)) {
|
|
return Token::ILLEGAL;
|
|
}
|
|
AddLiteralChar(c);
|
|
return ScanIdentifierSuffix(&literal);
|
|
}
|
|
|
|
uc32 first_char = c0_;
|
|
Advance();
|
|
AddLiteralChar(first_char);
|
|
|
|
// Scan the rest of the identifier characters.
|
|
while (unicode_cache_->IsIdentifierPart(c0_)) {
|
|
if (c0_ != '\\') {
|
|
uc32 next_char = c0_;
|
|
Advance();
|
|
AddLiteralChar(next_char);
|
|
continue;
|
|
}
|
|
// Fallthrough if no longer able to complete keyword.
|
|
return ScanIdentifierSuffix(&literal);
|
|
}
|
|
|
|
literal.Complete();
|
|
|
|
if (next_.literal_chars->is_ascii()) {
|
|
Vector<const char> chars = next_.literal_chars->ascii_literal();
|
|
return KeywordOrIdentifierToken(chars.start(),
|
|
chars.length(),
|
|
harmony_scoping_);
|
|
}
|
|
|
|
return Token::IDENTIFIER;
|
|
}
|
|
|
|
|
|
Token::Value Scanner::ScanIdentifierSuffix(LiteralScope* literal) {
|
|
// Scan the rest of the identifier characters.
|
|
while (unicode_cache_->IsIdentifierPart(c0_)) {
|
|
if (c0_ == '\\') {
|
|
uc32 c = ScanIdentifierUnicodeEscape();
|
|
// Only allow legal identifier part characters.
|
|
if (c < 0 ||
|
|
c == '\\' ||
|
|
!unicode_cache_->IsIdentifierPart(c)) {
|
|
return Token::ILLEGAL;
|
|
}
|
|
AddLiteralChar(c);
|
|
} else {
|
|
AddLiteralChar(c0_);
|
|
Advance();
|
|
}
|
|
}
|
|
literal->Complete();
|
|
|
|
return Token::IDENTIFIER;
|
|
}
|
|
|
|
|
|
bool Scanner::ScanRegExpPattern(bool seen_equal) {
|
|
// Scan: ('/' | '/=') RegularExpressionBody '/' RegularExpressionFlags
|
|
bool in_character_class = false;
|
|
|
|
// Previous token is either '/' or '/=', in the second case, the
|
|
// pattern starts at =.
|
|
next_.location.beg_pos = source_pos() - (seen_equal ? 2 : 1);
|
|
next_.location.end_pos = source_pos() - (seen_equal ? 1 : 0);
|
|
|
|
// Scan regular expression body: According to ECMA-262, 3rd, 7.8.5,
|
|
// the scanner should pass uninterpreted bodies to the RegExp
|
|
// constructor.
|
|
LiteralScope literal(this);
|
|
if (seen_equal) {
|
|
AddLiteralChar('=');
|
|
}
|
|
|
|
while (c0_ != '/' || in_character_class) {
|
|
if (unicode_cache_->IsLineTerminator(c0_) || c0_ < 0) return false;
|
|
if (c0_ == '\\') { // Escape sequence.
|
|
AddLiteralCharAdvance();
|
|
if (unicode_cache_->IsLineTerminator(c0_) || c0_ < 0) return false;
|
|
AddLiteralCharAdvance();
|
|
// If the escape allows more characters, i.e., \x??, \u????, or \c?,
|
|
// only "safe" characters are allowed (letters, digits, underscore),
|
|
// otherwise the escape isn't valid and the invalid character has
|
|
// its normal meaning. I.e., we can just continue scanning without
|
|
// worrying whether the following characters are part of the escape
|
|
// or not, since any '/', '\\' or '[' is guaranteed to not be part
|
|
// of the escape sequence.
|
|
|
|
// TODO(896): At some point, parse RegExps more throughly to capture
|
|
// octal esacpes in strict mode.
|
|
} else { // Unescaped character.
|
|
if (c0_ == '[') in_character_class = true;
|
|
if (c0_ == ']') in_character_class = false;
|
|
AddLiteralCharAdvance();
|
|
}
|
|
}
|
|
Advance(); // consume '/'
|
|
|
|
literal.Complete();
|
|
|
|
return true;
|
|
}
|
|
|
|
|
|
bool Scanner::ScanLiteralUnicodeEscape() {
|
|
ASSERT(c0_ == '\\');
|
|
uc32 chars_read[6] = {'\\', 'u', 0, 0, 0, 0};
|
|
Advance();
|
|
int i = 1;
|
|
if (c0_ == 'u') {
|
|
i++;
|
|
while (i < 6) {
|
|
Advance();
|
|
if (!IsHexDigit(c0_)) break;
|
|
chars_read[i] = c0_;
|
|
i++;
|
|
}
|
|
}
|
|
if (i < 6) {
|
|
// Incomplete escape. Undo all advances and return false.
|
|
while (i > 0) {
|
|
i--;
|
|
PushBack(chars_read[i]);
|
|
}
|
|
return false;
|
|
}
|
|
// Complete escape. Add all chars to current literal buffer.
|
|
for (int i = 0; i < 6; i++) {
|
|
AddLiteralChar(chars_read[i]);
|
|
}
|
|
return true;
|
|
}
|
|
|
|
|
|
bool Scanner::ScanRegExpFlags() {
|
|
// Scan regular expression flags.
|
|
LiteralScope literal(this);
|
|
while (unicode_cache_->IsIdentifierPart(c0_)) {
|
|
if (c0_ != '\\') {
|
|
AddLiteralCharAdvance();
|
|
} else {
|
|
if (!ScanLiteralUnicodeEscape()) {
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
literal.Complete();
|
|
|
|
next_.location.end_pos = source_pos() - 1;
|
|
return true;
|
|
}
|
|
|
|
} } // namespace v8::internal
|
|
|