jdk8-mips64-public/langtools: src/share/classes/com/sun/tools/javac/parser/UnicodeReader.java@d346ab55031b (annotated)

src/share/classes/com/sun/tools/javac/parser/UnicodeReader.java@d346ab55031b (annotated)

src/share/classes/com/sun/tools/javac/parser/UnicodeReader.java

Mon, 24 Oct 2011 13:00:20 +0100

author: mcimadamore
date: Mon, 24 Oct 2011 13:00:20 +0100
changeset 1113: d346ab55031b
child 1125: 56830d5cb5bb
permissions: -rw-r--r--

7096014: Javac tokens should retain state
Summary: Refactor javac tokens from enum constants to stateful instances (to keep track of position, comments, etc.)
Reviewed-by: jjg

 /*
  * Copyright (c) 2011, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 only, as
  * published by the Free Software Foundation.  Oracle designates this
  * particular file as subject to the "Classpath" exception as provided
  * by Oracle in the LICENSE file that accompanied this code.
  *
  * This code 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
  * version 2 for more details (a copy is included in the LICENSE file that
  * accompanied this code).
  *
  * You should have received a copy of the GNU General Public License version
  * 2 along with this work; if not, write to the Free Software Foundation,
  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  *
  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  * or visit www.oracle.com if you need additional information or have any
  * questions.
  */
 package com.sun.tools.javac.parser;
 import com.sun.tools.javac.file.JavacFileManager;
 import java.nio.CharBuffer;
 import com.sun.tools.javac.util.Log;
 import static com.sun.tools.javac.util.LayoutCharacters.*;
 /** The char reader used by the javac lexer/tokenizer. Returns the sequence of
  * characters contained in the input stream, handling unicode escape accordingly.
  * Additionally, it provide features for saving chars into a buffer and to retrieve
  * them at a later stage.
  *
  *  <p><b>This is NOT part of any supported API.
  *  If you write code that depends on this, you do so at your own risk.
  *  This code and its internal interfaces are subject to change or
  *  deletion without notice.</b>
  */
 public class UnicodeReader {
     /** The input buffer, index of next character to be read,
      *  index of one past last character in buffer.
      */
     protected char[] buf;
     protected int bp;
     protected final int buflen;
     /** The current character.
      */
     protected char ch;
     /** The buffer index of the last converted unicode character
      */
     protected int unicodeConversionBp = -1;
     protected Log log;
     /**
      * Create a scanner from the input array.  This method might
      * modify the array.  To avoid copying the input array, ensure
      * that {@code inputLength < input.length} or
      * {@code input[input.length -1]} is a white space character.
      *
      * @param fac the factory which created this Scanner
      * @param input the input, might be modified
      * @param inputLength the size of the input.
      * Must be positive and less than or equal to input.length.
      */
     protected UnicodeReader(ScannerFactory sf, CharBuffer buffer) {
         this(sf, JavacFileManager.toArray(buffer), buffer.limit());
     }
     protected UnicodeReader(ScannerFactory sf, char[] input, int inputLength) {
         log = sf.log;
         if (inputLength == input.length) {
             if (input.length > 0 && Character.isWhitespace(input[input.length - 1])) {
                 inputLength--;
             } else {
                 char[] newInput = new char[inputLength + 1];
                 System.arraycopy(input, 0, newInput, 0, input.length);
                 input = newInput;
             }
         }
         buf = input;
         buflen = inputLength;
         buf[buflen] = EOI;
         bp = -1;
         scanChar();
     }
     /** Read next character.
      */
     protected void scanChar() {
         if (bp < buflen) {
             ch = buf[++bp];
             if (ch == '\\') {
                 convertUnicode();
             }
         }
     }
     /** Convert unicode escape; bp points to initial '\' character
      *  (Spec 3.3).
      */
     protected void convertUnicode() {
         if (ch == '\\' && unicodeConversionBp != bp) {
             bp++; ch = buf[bp];
             if (ch == 'u') {
                 do {
                     bp++; ch = buf[bp];
                 } while (ch == 'u');
                 int limit = bp + 3;
                 if (limit < buflen) {
                     int d = digit(bp, 16);
                     int code = d;
                     while (bp < limit && d >= 0) {
                         bp++; ch = buf[bp];
                         d = digit(bp, 16);
                         code = (code << 4) + d;
                     }
                     if (d >= 0) {
                         ch = (char)code;
                         unicodeConversionBp = bp;
                         return;
                     }
                 }
                 log.error(bp, "illegal.unicode.esc");
             } else {
                 bp--;
                 ch = '\\';
             }
         }
     }
     /** Are surrogates supported?
      */
     final static boolean surrogatesSupported = surrogatesSupported();
     private static boolean surrogatesSupported() {
         try {
             Character.isHighSurrogate('a');
             return true;
         } catch (NoSuchMethodError ex) {
             return false;
         }
     }
     /** Scan surrogate pairs.  If 'ch' is a high surrogate and
      *  the next character is a low surrogate, then put the low
      *  surrogate in 'ch', and return the high surrogate.
      *  otherwise, just return 0.
      */
     protected char scanSurrogates() {
         if (surrogatesSupported && Character.isHighSurrogate(ch)) {
             char high = ch;
             scanChar();
             if (Character.isLowSurrogate(ch)) {
                 return high;
             }
             ch = high;
         }
         return 0;
     }
     /** Convert an ASCII digit from its base (8, 10, or 16)
      *  to its value.
      */
     protected int digit(int pos, int base) {
         char c = ch;
         int result = Character.digit(c, base);
         if (result >= 0 && c > 0x7f) {
             log.error(pos + 1, "illegal.nonascii.digit");
             ch = "0123456789abcdef".charAt(result);
         }
         return result;
     }
     protected boolean isUnicode() {
         return unicodeConversionBp == bp;
     }
     protected void skipChar() {
         bp++;
     }
     protected char peekChar() {
         return buf[bp + 1];
     }
     /**
      * Returns a copy of the input buffer, up to its inputLength.
      * Unicode escape sequences are not translated.
      */
     public char[] getRawCharacters() {
         char[] chars = new char[buflen];
         System.arraycopy(buf, 0, chars, 0, buflen);
         return chars;
     }
     /**
      * Returns a copy of a character array subset of the input buffer.
      * The returned array begins at the <code>beginIndex</code> and
      * extends to the character at index <code>endIndex - 1</code>.
      * Thus the length of the substring is <code>endIndex-beginIndex</code>.
      * This behavior is like
      * <code>String.substring(beginIndex, endIndex)</code>.
      * Unicode escape sequences are not translated.
      *
      * @param beginIndex the beginning index, inclusive.
      * @param endIndex the ending index, exclusive.
      * @throws IndexOutOfBounds if either offset is outside of the
      *         array bounds
      */
     public char[] getRawCharacters(int beginIndex, int endIndex) {
         int length = endIndex - beginIndex;
         char[] chars = new char[length];
         System.arraycopy(buf, beginIndex, chars, 0, length);
         return chars;
     }
 }

Mercurial > jdk8-mips64-public > langtools / annotate

src/share/classes/com/sun/tools/javac/parser/UnicodeReader.java@d346ab55031b (annotated)

src/share/classes/com/sun/tools/javac/parser/UnicodeReader.java