| 1 | /* |
| 2 | * Copyright 1999-2006 Sun Microsystems, Inc. All Rights Reserved. |
| 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| 4 | * |
| 5 | * This code is free software; you can redistribute it and/or modify it |
| 6 | * under the terms of the GNU General Public License version 2 only, as |
| 7 | * published by the Free Software Foundation. Sun designates this |
| 8 | * particular file as subject to the "Classpath" exception as provided |
| 9 | * by Sun in the LICENSE file that accompanied this code. |
| 10 | * |
| 11 | * This code is distributed in the hope that it will be useful, but WITHOUT |
| 12 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 13 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| 14 | * version 2 for more details (a copy is included in the LICENSE file that |
| 15 | * accompanied this code). |
| 16 | * |
| 17 | * You should have received a copy of the GNU General Public License version |
| 18 | * 2 along with this work; if not, write to the Free Software Foundation, |
| 19 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| 20 | * |
| 21 | * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
| 22 | * CA 95054 USA or visit www.sun.com if you need additional information or |
| 23 | * have any questions. |
| 24 | */ |
| 25 | |
| 26 | package com.sun.tools.javac.util; |
| 27 | |
| 28 | import java.util.BitSet; |
| 29 | import static com.sun.tools.javac.util.LayoutCharacters.*; |
| 30 | |
| 31 | /** A class that defines source code positions as simple character |
| 32 | * offsets from the beginning of the file. The first character |
| 33 | * is at position 0. |
| 34 | * |
| 35 | * Support is also provided for (line,column) coordinates, but tab |
| 36 | * expansion is optional and no Unicode excape translation is considered. |
| 37 | * The first character is at location (1,1). |
| 38 | * |
| 39 | * <p><b>This is NOT part of any API supported by Sun Microsystems. If |
| 40 | * you write code that depends on this, you do so at your own risk. |
| 41 | * This code and its internal interfaces are subject to change or |
| 42 | * deletion without notice.</b> |
| 43 | */ |
| 44 | public class Position { |
| 45 | public static final int NOPOS = -1; |
| 46 | |
| 47 | public static final int FIRSTPOS = 0; |
| 48 | public static final int FIRSTLINE = 1; |
| 49 | public static final int FIRSTCOLUMN = 1; |
| 50 | |
| 51 | public static final int LINESHIFT = 10; |
| 52 | public static final int MAXCOLUMN = (1<<LINESHIFT) - 1; |
| 53 | public static final int MAXLINE = (1<<(Integer.SIZE-LINESHIFT)) - 1; |
| 54 | |
| 55 | public static final int MAXPOS = Integer.MAX_VALUE; |
| 56 | |
| 57 | /** |
| 58 | * This is class is not supposed to be instantiated. |
| 59 | */ |
| 60 | private Position() {} |
| 61 | |
| 62 | /** A two-way map between line/column numbers and positions, |
| 63 | * derived from a scan done at creation time. Tab expansion is |
| 64 | * optionally supported via a character map. Text content |
| 65 | * is not retained. |
| 66 | *<p> |
| 67 | * Notes: The first character position FIRSTPOS is at |
| 68 | * (FIRSTLINE,FIRSTCOLUMN). No account is taken of Unicode escapes. |
| 69 | * |
| 70 | * @param src Source characters |
| 71 | * @param max Number of characters to read |
| 72 | * @param expandTabs If true, expand tabs when calculating columns |
| 73 | */ |
| 74 | public static LineMap makeLineMap(char[] src, int max, boolean expandTabs) { |
| 75 | LineMapImpl lineMap = expandTabs ? |
| 76 | new LineTabMapImpl(max) : new LineMapImpl(); |
| 77 | lineMap.build(src, max); |
| 78 | return lineMap; |
| 79 | } |
| 80 | |
| 81 | /** Encode line and column numbers in an integer as: |
| 82 | * line-number << LINESHIFT + column-number |
| 83 | * {@link Position.NOPOS represents an undefined position. |
| 84 | * |
| 85 | * @param line number of line (first is 1) |
| 86 | * @param col number of character on line (first is 1) |
| 87 | * @return an encoded position or {@link Position.NOPOS |
| 88 | * if the line or column number is too big to |
| 89 | * represent in the encoded format |
| 90 | * @throws IllegalArgumentException if line or col is less than 1 |
| 91 | */ |
| 92 | public static int encodePosition(int line, int col) { |
| 93 | if (line < 1) |
| 94 | throw new IllegalArgumentException("line must be greater than 0"); |
| 95 | if (col < 1) |
| 96 | throw new IllegalArgumentException("column must be greater than 0"); |
| 97 | |
| 98 | if (line > MAXLINE || col > MAXCOLUMN) { |
| 99 | return NOPOS; |
| 100 | } |
| 101 | return (line << LINESHIFT) + col; |
| 102 | } |
| 103 | |
| 104 | public static interface LineMap extends com.sun.source.tree.LineMap { |
| 105 | /** Find the start position of a line. |
| 106 | * |
| 107 | * @param line number of line (first is 1) |
| 108 | * @return position of first character in line |
| 109 | * @throws ArrayIndexOutOfBoundsException |
| 110 | * if <tt>lineNumber < 1</tt> |
| 111 | * if <tt>lineNumber > no. of lines</tt> |
| 112 | */ |
| 113 | int getStartPosition(int line); |
| 114 | |
| 115 | /** Find the position corresponding to a (line,column). |
| 116 | * |
| 117 | * @param line number of line (first is 1) |
| 118 | * @param column number of character on line (first is 1) |
| 119 | * |
| 120 | * @return position of character |
| 121 | * @throws ArrayIndexOutOfBoundsException |
| 122 | * if <tt>line < 1</tt> |
| 123 | * if <tt>line > no. of lines</tt> |
| 124 | */ |
| 125 | int getPosition(int line, int column); |
| 126 | |
| 127 | /** Find the line containing a position; a line termination |
| 128 | * character is on the line it terminates. |
| 129 | * |
| 130 | * @param pos character offset of the position |
| 131 | * @return the line number on which pos occurs (first line is 1) |
| 132 | */ |
| 133 | int getLineNumber(int pos); |
| 134 | |
| 135 | /** Find the column for a character position. |
| 136 | * Note: this method does not handle tab expansion. |
| 137 | * If tab expansion is needed, use a LineTabMap instead. |
| 138 | * |
| 139 | * @param pos character offset of the position |
| 140 | * @return the column number at which pos occurs |
| 141 | */ |
| 142 | int getColumnNumber(int pos); |
| 143 | } |
| 144 | |
| 145 | static class LineMapImpl implements LineMap { |
| 146 | protected int[] startPosition; // start position of each line |
| 147 | |
| 148 | protected LineMapImpl() {} |
| 149 | |
| 150 | protected void build(char[] src, int max) { |
| 151 | int c = 0; |
| 152 | int i = 0; |
| 153 | int[] linebuf = new int[max]; |
| 154 | while (i < max) { |
| 155 | linebuf[c++] = i; |
| 156 | do { |
| 157 | char ch = src[i]; |
| 158 | if (ch == '\r' || ch == '\n') { |
| 159 | if (ch == '\r' && (i+1) < max && src[i+1] == '\n') |
| 160 | i += 2; |
| 161 | else |
| 162 | ++i; |
| 163 | break; |
| 164 | } |
| 165 | else if (ch == '\t') |
| 166 | setTabPosition(i); |
| 167 | } while (++i < max); |
| 168 | } |
| 169 | this.startPosition = new int[c]; |
| 170 | System.arraycopy(linebuf, 0, startPosition, 0, c); |
| 171 | } |
| 172 | |
| 173 | public int getStartPosition(int line) { |
| 174 | return startPosition[line - FIRSTLINE]; |
| 175 | } |
| 176 | |
| 177 | public long getStartPosition(long line) { |
| 178 | return getStartPosition(longToInt(line)); |
| 179 | } |
| 180 | |
| 181 | public int getPosition(int line, int column) { |
| 182 | return startPosition[line - FIRSTLINE] + column - FIRSTCOLUMN; |
| 183 | } |
| 184 | |
| 185 | public long getPosition(long line, long column) { |
| 186 | return getPosition(longToInt(line), longToInt(column)); |
| 187 | } |
| 188 | |
| 189 | // Cache of last line number lookup |
| 190 | private int lastPosition = Position.FIRSTPOS; |
| 191 | private int lastLine = Position.FIRSTLINE; |
| 192 | |
| 193 | public int getLineNumber(int pos) { |
| 194 | if (pos == lastPosition) { |
| 195 | return lastLine; |
| 196 | } |
| 197 | lastPosition = pos; |
| 198 | |
| 199 | int low = 0; |
| 200 | int high = startPosition.length-1; |
| 201 | while (low <= high) { |
| 202 | int mid = (low + high) >> 1; |
| 203 | int midVal = startPosition[mid]; |
| 204 | |
| 205 | if (midVal < pos) |
| 206 | low = mid + 1; |
| 207 | else if (midVal > pos) |
| 208 | high = mid - 1; |
| 209 | else { |
| 210 | lastLine = mid + 1; // pos is at beginning of this line |
| 211 | return lastLine; |
| 212 | } |
| 213 | } |
| 214 | lastLine = low; |
| 215 | return lastLine; // pos is on this line |
| 216 | } |
| 217 | |
| 218 | public long getLineNumber(long pos) { |
| 219 | return getLineNumber(longToInt(pos)); |
| 220 | } |
| 221 | |
| 222 | public int getColumnNumber(int pos) { |
| 223 | return pos - startPosition[getLineNumber(pos) - FIRSTLINE] + FIRSTCOLUMN; |
| 224 | } |
| 225 | |
| 226 | public long getColumnNumber(long pos) { |
| 227 | return getColumnNumber(longToInt(pos)); |
| 228 | } |
| 229 | |
| 230 | private static int longToInt(long longValue) { |
| 231 | int intValue = (int)longValue; |
| 232 | if (intValue != longValue) |
| 233 | throw new IndexOutOfBoundsException(); |
| 234 | return intValue; |
| 235 | } |
| 236 | |
| 237 | protected void setTabPosition(int offset) {} |
| 238 | } |
| 239 | |
| 240 | /** |
| 241 | * A LineMap that handles tab expansion correctly. The cost is |
| 242 | * an additional bit per character in the source array. |
| 243 | */ |
| 244 | public static class LineTabMapImpl extends LineMapImpl { |
| 245 | private BitSet tabMap; // bits set for tab positions. |
| 246 | |
| 247 | public LineTabMapImpl(int max) { |
| 248 | super(); |
| 249 | tabMap = new BitSet(max); |
| 250 | } |
| 251 | |
| 252 | protected void setTabPosition(int offset) { |
| 253 | tabMap.set(offset); |
| 254 | } |
| 255 | |
| 256 | public int getColumnNumber(int pos) { |
| 257 | int lineStart = startPosition[getLineNumber(pos) - FIRSTLINE]; |
| 258 | int column = 0; |
| 259 | for (int bp = lineStart; bp < pos; bp++) { |
| 260 | if (tabMap.get(bp)) |
| 261 | column = (column / TabInc * TabInc) + TabInc; |
| 262 | else |
| 263 | column++; |
| 264 | } |
| 265 | return column + FIRSTCOLUMN; |
| 266 | } |
| 267 | |
| 268 | public int getPosition(int line, int column) { |
| 269 | int pos = startPosition[line - FIRSTLINE]; |
| 270 | column -= FIRSTCOLUMN; |
| 271 | int col = 0; |
| 272 | while (col < column) { |
| 273 | pos++; |
| 274 | if (tabMap.get(pos)) |
| 275 | col = (col / TabInc * TabInc) + TabInc; |
| 276 | else |
| 277 | col++; |
| 278 | } |
| 279 | return pos; |
| 280 | } |
| 281 | } |
| 282 | } |