001 /*
002 * Copyright 1999-2008 Sun Microsystems, Inc. All Rights Reserved.
003 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
004 *
005 * This code is free software; you can redistribute it and/or modify it
006 * under the terms of the GNU General Public License version 2 only, as
007 * published by the Free Software Foundation. Sun designates this
008 * particular file as subject to the "Classpath" exception as provided
009 * by Sun in the LICENSE file that accompanied this code.
010 *
011 * This code is distributed in the hope that it will be useful, but WITHOUT
012 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
013 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
014 * version 2 for more details (a copy is included in the LICENSE file that
015 * accompanied this code).
016 *
017 * You should have received a copy of the GNU General Public License version
018 * 2 along with this work; if not, write to the Free Software Foundation,
019 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
020 *
021 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
022 * CA 95054 USA or visit www.sun.com if you need additional information or
023 * have any questions.
024 */
025
026 package com.sun.tools.javac.util;
027
028 import java.io.IOException;
029 import java.lang.ref.SoftReference;
030 import java.nio.CharBuffer;
031 import java.util.Map;
032 import javax.tools.JavaFileObject;
033
034 import com.sun.tools.javac.file.JavacFileManager;
035 import com.sun.tools.javac.tree.JCTree;
036
037 import static com.sun.tools.javac.util.LayoutCharacters.*;
038
039 /**
040 * A simple abstraction of a source file, as needed for use in a diagnostic message.
041 * Provides access to the line and position in a line for any given character offset.
042 *
043 * <p><b>This is NOT part of any API supported by Sun Microsystems. If
044 * you write code that depends on this, you do so at your own risk.
045 * This code and its internal interfaces are subject to change or
046 * deletion without notice.</b>
047 */
048 public class DiagnosticSource {
049 public DiagnosticSource(JavaFileObject fo, AbstractLog log) {
050 this.fileObject = fo;
051 this.log = log;
052 }
053
054 /** Return the underlying file object handled by this
055 * DiagnosticSource object.
056 */
057 public JavaFileObject getFile() {
058 return fileObject;
059 }
060
061 public CharSequence getName() {
062 return JavacFileManager.getJavacBaseFileName(fileObject);
063 }
064
065 /** Return the one-based line number associated with a given pos
066 * for the current source file. Zero is returned if no line exists
067 * for the given position.
068 */
069 public int getLineNumber(int pos) {
070 try {
071 if (findLine(pos)) {
072 return line;
073 }
074 return 0;
075 } finally {
076 buf = null;
077 }
078 }
079
080 /** Return the one-based column number associated with a given pos
081 * for the current source file. Zero is returned if no column exists
082 * for the given position.
083 */
084 public int getColumnNumber(int pos, boolean expandTabs) {
085 try {
086 if (findLine(pos)) {
087 int column = 0;
088 for (int bp = lineStart; bp < pos; bp++) {
089 if (bp >= bufLen) {
090 return 0;
091 }
092 if (buf[bp] == '\t' && expandTabs) {
093 column = (column / TabInc * TabInc) + TabInc;
094 } else {
095 column++;
096 }
097 }
098 return column + 1; // positions are one-based
099 }
100 return 0;
101 } finally {
102 buf = null;
103 }
104 }
105
106 /** Return the content of the line containing a given pos.
107 */
108 public String getLine(int pos) {
109 try {
110 if (!findLine(pos))
111 return null;
112
113 int lineEnd = lineStart;
114 while (lineEnd < bufLen && buf[lineEnd] != CR && buf[lineEnd] != LF)
115 lineEnd++;
116 if (lineEnd - lineStart == 0)
117 return null;
118 return new String(buf, lineStart, lineEnd - lineStart);
119 } finally {
120 buf = null;
121 }
122 }
123
124 public Map<JCTree, Integer> getEndPosTable() {
125 return endPosTable;
126 }
127
128 public void setEndPosTable(Map<JCTree, Integer> t) {
129 if (endPosTable != null && endPosTable != t)
130 throw new IllegalStateException("endPosTable already set");
131 endPosTable = t;
132 }
133
134 /** Find the line in the buffer that contains the current position
135 * @param pos Character offset into the buffer
136 */
137 private boolean findLine(int pos) {
138 if (pos == Position.NOPOS)
139 return false;
140
141 try {
142 // try and recover buffer from soft reference cache
143 if (buf == null && refBuf != null)
144 buf = refBuf.get();
145
146 if (buf == null) {
147 buf = initBuf(fileObject);
148 lineStart = 0;
149 line = 1;
150 } else if (lineStart > pos) { // messages don't come in order
151 lineStart = 0;
152 line = 1;
153 }
154
155 int bp = lineStart;
156 while (bp < bufLen && bp < pos) {
157 switch (buf[bp++]) {
158 case CR:
159 if (bp < bufLen && buf[bp] == LF) bp++;
160 line++;
161 lineStart = bp;
162 break;
163 case LF:
164 line++;
165 lineStart = bp;
166 break;
167 }
168 }
169 return bp <= bufLen;
170 } catch (IOException e) {
171 log.directError("source.unavailable");
172 buf = new char[0];
173 return false;
174 }
175 }
176
177 protected char[] initBuf(JavaFileObject fileObject) throws IOException {
178 char[] buf;
179 CharSequence cs = fileObject.getCharContent(true);
180 if (cs instanceof CharBuffer) {
181 CharBuffer cb = (CharBuffer) cs;
182 buf = JavacFileManager.toArray(cb);
183 bufLen = cb.limit();
184 } else {
185 buf = cs.toString().toCharArray();
186 bufLen = buf.length;
187 }
188 refBuf = new SoftReference<char[]>(buf);
189 return buf;
190 }
191
192 /** The underlying file object. */
193 protected JavaFileObject fileObject;
194
195 protected Map<JCTree, Integer> endPosTable;
196
197 /** A soft reference to the content of the file object. */
198 protected SoftReference<char[]> refBuf;
199
200 /** A temporary hard reference to the content of the file object. */
201 protected char[] buf;
202
203 /** The length of the content. */
204 protected int bufLen;
205
206 /** The start of a line found by findLine. */
207 protected int lineStart;
208
209 /** The line number of a line found by findLine. */
210 protected int line;
211
212 /** A log for reporting errors, such as errors accessing the content. */
213 protected AbstractLog log;
214 }