jdk8-mips64-public/langtools: src/share/classes/com/sun/tools/javac/util/Position.java@f2fdd52e4e87 (annotated)

src/share/classes/com/sun/tools/javac/util/Position.java@f2fdd52e4e87 (annotated)

src/share/classes/com/sun/tools/javac/util/Position.java

Thu, 10 Jun 2010 16:08:01 -0700

author: jjg
date: Thu, 10 Jun 2010 16:08:01 -0700
changeset 581: f2fdd52e4e87
parent 554: 9d9f26857129
child 1326: 30c36e23f154
permissions: -rw-r--r--

6944312: Potential rebranding issues in openjdk/langtools repository sources
Reviewed-by: darcy

 /*
  * Copyright (c) 1999, 2006, 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.util;
 import java.util.BitSet;
 import static com.sun.tools.javac.util.LayoutCharacters.*;
 /** A class that defines source code positions as simple character
  *  offsets from the beginning of the file. The first character
  *  is at position 0.
  *
  *  Support is also provided for (line,column) coordinates, but tab
  *  expansion is optional and no Unicode excape translation is considered.
  *  The first character is at location (1,1).
  *
  *  <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 Position {
     public static final int NOPOS        = -1;
     public static final int FIRSTPOS     = 0;
     public static final int FIRSTLINE    = 1;
     public static final int FIRSTCOLUMN  = 1;
     public static final int LINESHIFT    = 10;
     public static final int MAXCOLUMN    = (1<<LINESHIFT) - 1;
     public static final int MAXLINE      = (1<<(Integer.SIZE-LINESHIFT)) - 1;
     public static final int MAXPOS       = Integer.MAX_VALUE;
     /**
      * This is class is not supposed to be instantiated.
      */
     private Position() {}
     /** A two-way map between line/column numbers and positions,
      *  derived from a scan done at creation time.  Tab expansion is
      *  optionally supported via a character map.  Text content
      *  is not retained.
      *<p>
      *  Notes:  The first character position FIRSTPOS is at
      *  (FIRSTLINE,FIRSTCOLUMN).  No account is taken of Unicode escapes.
      *
      * @param   src         Source characters
      * @param   max         Number of characters to read
      * @param   expandTabs  If true, expand tabs when calculating columns
      */
     public static LineMap makeLineMap(char[] src, int max, boolean expandTabs) {
         LineMapImpl lineMap = expandTabs ?
             new LineTabMapImpl(max) : new LineMapImpl();
         lineMap.build(src, max);
         return lineMap;
     }
     /** Encode line and column numbers in an integer as:
      *  line-number << LINESHIFT + column-number
      *  {@link Position.NOPOS represents an undefined position.
      *
      * @param  line  number of line (first is 1)
      * @param  col   number of character on line (first is 1)
      * @return       an encoded position or {@link Position.NOPOS
      *               if the line or column number is too big to
      *               represent in the encoded format
      * @throws IllegalArgumentException if line or col is less than 1
      */
     public static int encodePosition(int line, int col) {
         if (line < 1)
             throw new IllegalArgumentException("line must be greater than 0");
         if (col < 1)
             throw new IllegalArgumentException("column must be greater than 0");
         if (line > MAXLINE || col > MAXCOLUMN) {
             return NOPOS;
         }
         return (line << LINESHIFT) + col;
     }
     public static interface LineMap extends com.sun.source.tree.LineMap {
         /** Find the start position of a line.
          *
          * @param line number of line (first is 1)
          * @return     position of first character in line
          * @throws  ArrayIndexOutOfBoundsException
          *           if <tt>lineNumber < 1</tt>
          *           if <tt>lineNumber > no. of lines</tt>
          */
         int getStartPosition(int line);
         /** Find the position corresponding to a (line,column).
          *
          * @param   line    number of line (first is 1)
          * @param   column  number of character on line (first is 1)
          *
          * @return  position of character
          * @throws  ArrayIndexOutOfBoundsException
          *           if <tt>line < 1</tt>
          *           if <tt>line > no. of lines</tt>
          */
         int getPosition(int line, int column);
         /** Find the line containing a position; a line termination
          * character is on the line it terminates.
          *
          * @param   pos  character offset of the position
          * @return the line number on which pos occurs (first line is 1)
          */
         int getLineNumber(int pos);
         /** Find the column for a character position.
          *  Note:  this method does not handle tab expansion.
          *  If tab expansion is needed, use a LineTabMap instead.
          *
          * @param  pos   character offset of the position
          * @return       the column number at which pos occurs
          */
         int getColumnNumber(int pos);
     }
     static class LineMapImpl implements LineMap {
         protected int[] startPosition; // start position of each line
         protected LineMapImpl() {}
         protected void build(char[] src, int max) {
             int c = 0;
             int i = 0;
             int[] linebuf = new int[max];
             while (i < max) {
                 linebuf[c++] = i;
                 do {
                     char ch = src[i];
                     if (ch == '\r' || ch == '\n') {
                         if (ch == '\r' && (i+1) < max && src[i+1] == '\n')
                             i += 2;
                         else
                             ++i;
                         break;
                     }
                     else if (ch == '\t')
                         setTabPosition(i);
                 } while (++i < max);
             }
             this.startPosition = new int[c];
             System.arraycopy(linebuf, 0, startPosition, 0, c);
         }
         public int getStartPosition(int line) {
             return startPosition[line - FIRSTLINE];
         }
         public long getStartPosition(long line) {
             return getStartPosition(longToInt(line));
         }
         public int getPosition(int line, int column) {
             return startPosition[line - FIRSTLINE] + column - FIRSTCOLUMN;
         }
         public long getPosition(long line, long column) {
             return getPosition(longToInt(line), longToInt(column));
         }
         // Cache of last line number lookup
         private int lastPosition = Position.FIRSTPOS;
         private int lastLine = Position.FIRSTLINE;
         public int getLineNumber(int pos) {
             if (pos == lastPosition) {
                 return lastLine;
             }
             lastPosition = pos;
             int low = 0;
             int high = startPosition.length-1;
             while (low <= high) {
                 int mid = (low + high) >> 1;
                 int midVal = startPosition[mid];
                 if (midVal < pos)
                     low = mid + 1;
                 else if (midVal > pos)
                     high = mid - 1;
                 else {
                     lastLine = mid + 1; // pos is at beginning of this line
                     return lastLine;
                 }
             }
             lastLine = low;
             return lastLine;  // pos is on this line
         }
         public long getLineNumber(long pos) {
             return getLineNumber(longToInt(pos));
         }
         public int getColumnNumber(int pos) {
             return pos - startPosition[getLineNumber(pos) - FIRSTLINE] + FIRSTCOLUMN;
         }
         public long getColumnNumber(long pos) {
             return getColumnNumber(longToInt(pos));
         }
         private static int longToInt(long longValue) {
             int intValue = (int)longValue;
             if (intValue != longValue)
                 throw new IndexOutOfBoundsException();
             return intValue;
         }
         protected void setTabPosition(int offset) {}
     }
     /**
      * A LineMap that handles tab expansion correctly.  The cost is
      * an additional bit per character in the source array.
      */
     public static class LineTabMapImpl extends LineMapImpl {
         private BitSet tabMap;       // bits set for tab positions.
         public LineTabMapImpl(int max) {
             super();
             tabMap = new BitSet(max);
         }
         protected void setTabPosition(int offset) {
             tabMap.set(offset);
         }
         public int getColumnNumber(int pos) {
             int lineStart = startPosition[getLineNumber(pos) - FIRSTLINE];
             int column = 0;
             for (int bp = lineStart; bp < pos; bp++) {
                 if (tabMap.get(bp))
                     column = (column / TabInc * TabInc) + TabInc;
                 else
                     column++;
             }
             return column + FIRSTCOLUMN;
         }
         public int getPosition(int line, int column) {
             int pos = startPosition[line - FIRSTLINE];
             column -= FIRSTCOLUMN;
             int col = 0;
             while (col < column) {
                 pos++;
                 if (tabMap.get(pos))
                     col = (col / TabInc * TabInc) + TabInc;
                 else
                     col++;
             }
             return pos;
         }
     }
 }

Mercurial > jdk8-mips64-public > langtools / annotate

src/share/classes/com/sun/tools/javac/util/Position.java@f2fdd52e4e87 (annotated)

src/share/classes/com/sun/tools/javac/util/Position.java