jjg@73: /*
ohair@554:  * Copyright (c) 1999, 2008, Oracle and/or its affiliates. All rights reserved.
jjg@73:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
jjg@73:  *
jjg@73:  * This code is free software; you can redistribute it and/or modify it
jjg@73:  * under the terms of the GNU General Public License version 2 only, as
ohair@554:  * published by the Free Software Foundation.  Oracle designates this
jjg@73:  * particular file as subject to the "Classpath" exception as provided
ohair@554:  * by Oracle in the LICENSE file that accompanied this code.
jjg@73:  *
jjg@73:  * This code is distributed in the hope that it will be useful, but WITHOUT
jjg@73:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
jjg@73:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
jjg@73:  * version 2 for more details (a copy is included in the LICENSE file that
jjg@73:  * accompanied this code).
jjg@73:  *
jjg@73:  * You should have received a copy of the GNU General Public License version
jjg@73:  * 2 along with this work; if not, write to the Free Software Foundation,
jjg@73:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
jjg@73:  *
ohair@554:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
ohair@554:  * or visit www.oracle.com if you need additional information or have any
ohair@554:  * questions.
jjg@73:  */
jjg@73: 
jjg@73: package com.sun.tools.javac.util;
jjg@73: 
jjg@73: import java.io.IOException;
jjg@73: import java.lang.ref.SoftReference;
jjg@73: import java.nio.CharBuffer;
jjg@73: import java.util.Map;
jjg@73: import javax.tools.JavaFileObject;
jjg@73: 
jjg@73: import com.sun.tools.javac.file.JavacFileManager;
jjg@73: import com.sun.tools.javac.tree.JCTree;
jjg@73: 
jjg@73: import static com.sun.tools.javac.util.LayoutCharacters.*;
jjg@73: 
jjg@73: /**
jjg@73:  * A simple abstraction of a source file, as needed for use in a diagnostic message.
jjg@73:  * Provides access to the line and position in a line for any given character offset.
jjg@73:  *
jjg@581:  *  <p><b>This is NOT part of any supported API.
jjg@581:  *  If you write code that depends on this, you do so at your own risk.
jjg@73:  *  This code and its internal interfaces are subject to change or
jjg@73:  *  deletion without notice.</b>
jjg@73:  */
jjg@73: public class DiagnosticSource {
mcimadamore@303: 
mcimadamore@303:     /* constant DiagnosticSource to be used when sourcefile is missing */
mcimadamore@303:     public static final DiagnosticSource NO_SOURCE = new DiagnosticSource() {
mcimadamore@303:         @Override
mcimadamore@303:         protected boolean findLine(int pos) {
mcimadamore@303:             return false;
mcimadamore@303:         }
mcimadamore@303:     };
mcimadamore@303: 
jjg@73:     public DiagnosticSource(JavaFileObject fo, AbstractLog log) {
jjg@73:         this.fileObject = fo;
jjg@73:         this.log = log;
jjg@73:     }
jjg@73: 
mcimadamore@303:     private DiagnosticSource() {}
mcimadamore@303: 
jjg@73:     /** Return the underlying file object handled by this
jjg@73:      *  DiagnosticSource object.
jjg@73:      */
jjg@73:     public JavaFileObject getFile() {
jjg@73:         return fileObject;
jjg@73:     }
jjg@73: 
jjg@73:     /** Return the one-based line number associated with a given pos
jjg@73:      * for the current source file.  Zero is returned if no line exists
jjg@73:      * for the given position.
jjg@73:      */
jjg@73:     public int getLineNumber(int pos) {
jjg@73:         try {
jjg@73:             if (findLine(pos)) {
jjg@73:                 return line;
jjg@73:             }
jjg@73:             return 0;
jjg@73:         } finally {
jjg@73:             buf = null;
jjg@73:         }
jjg@73:     }
jjg@73: 
jjg@73:     /** Return the one-based column number associated with a given pos
jjg@73:      * for the current source file.  Zero is returned if no column exists
jjg@73:      * for the given position.
jjg@73:      */
mcimadamore@100:     public int getColumnNumber(int pos, boolean expandTabs) {
jjg@73:         try {
jjg@73:             if (findLine(pos)) {
jjg@73:                 int column = 0;
jjg@73:                 for (int bp = lineStart; bp < pos; bp++) {
jjg@73:                     if (bp >= bufLen) {
jjg@73:                         return 0;
jjg@73:                     }
mcimadamore@100:                     if (buf[bp] == '\t' && expandTabs) {
jjg@73:                         column = (column / TabInc * TabInc) + TabInc;
jjg@73:                     } else {
jjg@73:                         column++;
jjg@73:                     }
jjg@73:                 }
jjg@73:                 return column + 1; // positions are one-based
jjg@73:             }
jjg@73:             return 0;
jjg@73:         } finally {
jjg@73:             buf = null;
jjg@73:         }
jjg@73:     }
jjg@73: 
jjg@73:     /** Return the content of the line containing a given pos.
jjg@73:      */
jjg@73:     public String getLine(int pos) {
jjg@73:         try {
jjg@73:             if (!findLine(pos))
jjg@73:                 return null;
jjg@73: 
jjg@73:             int lineEnd = lineStart;
jjg@73:             while (lineEnd < bufLen && buf[lineEnd] != CR && buf[lineEnd] != LF)
jjg@73:                 lineEnd++;
jjg@73:             if (lineEnd - lineStart == 0)
jjg@73:                 return null;
jjg@73:             return new String(buf, lineStart, lineEnd - lineStart);
jjg@73:         } finally {
jjg@73:             buf = null;
jjg@73:         }
jjg@73:     }
jjg@73: 
jjg@73:     public Map<JCTree, Integer> getEndPosTable() {
jjg@73:         return endPosTable;
jjg@73:     }
jjg@73: 
jjg@73:     public void setEndPosTable(Map<JCTree, Integer> t) {
jjg@73:         if (endPosTable != null && endPosTable != t)
jjg@73:             throw new IllegalStateException("endPosTable already set");
jjg@73:         endPosTable = t;
jjg@73:     }
jjg@73: 
jjg@73:     /** Find the line in the buffer that contains the current position
jjg@73:      * @param pos      Character offset into the buffer
jjg@73:      */
mcimadamore@303:     protected boolean findLine(int pos) {
jjg@73:         if (pos == Position.NOPOS)
jjg@73:             return false;
jjg@73: 
jjg@73:         try {
jjg@73:             // try and recover buffer from soft reference cache
jjg@73:             if (buf == null && refBuf != null)
jjg@73:                 buf = refBuf.get();
jjg@73: 
jjg@73:             if (buf == null) {
jjg@73:                 buf = initBuf(fileObject);
jjg@73:                 lineStart = 0;
jjg@73:                 line = 1;
jjg@73:             } else if (lineStart > pos) { // messages don't come in order
jjg@73:                 lineStart = 0;
jjg@73:                 line = 1;
jjg@73:             }
jjg@73: 
jjg@73:             int bp = lineStart;
jjg@73:             while (bp < bufLen && bp < pos) {
jjg@73:                 switch (buf[bp++]) {
jjg@73:                 case CR:
jjg@73:                     if (bp < bufLen && buf[bp] == LF) bp++;
jjg@73:                     line++;
jjg@73:                     lineStart = bp;
jjg@73:                     break;
jjg@73:                 case LF:
jjg@73:                     line++;
jjg@73:                     lineStart = bp;
jjg@73:                     break;
jjg@73:                 }
jjg@73:             }
jjg@73:             return bp <= bufLen;
jjg@73:         } catch (IOException e) {
jjg@73:             log.directError("source.unavailable");
jjg@73:             buf = new char[0];
jjg@73:             return false;
jjg@73:         }
jjg@73:     }
jjg@73: 
jjg@73:     protected char[] initBuf(JavaFileObject fileObject) throws IOException {
jjg@73:         char[] buf;
jjg@73:         CharSequence cs = fileObject.getCharContent(true);
jjg@73:         if (cs instanceof CharBuffer) {
jjg@73:             CharBuffer cb = (CharBuffer) cs;
jjg@73:             buf = JavacFileManager.toArray(cb);
jjg@73:             bufLen = cb.limit();
jjg@73:         } else {
jjg@73:             buf = cs.toString().toCharArray();
jjg@73:             bufLen = buf.length;
jjg@73:         }
jjg@73:         refBuf = new SoftReference<char[]>(buf);
jjg@73:         return buf;
jjg@73:     }
jjg@73: 
jjg@73:     /** The underlying file object. */
jjg@73:     protected JavaFileObject fileObject;
jjg@73: 
jjg@73:     protected Map<JCTree, Integer> endPosTable;
jjg@73: 
jjg@73:     /** A soft reference to the content of the file object. */
jjg@73:     protected SoftReference<char[]> refBuf;
jjg@73: 
jjg@73:     /** A temporary hard reference to the content of the file object. */
jjg@73:     protected char[] buf;
jjg@73: 
jjg@73:     /** The length of the content. */
jjg@73:     protected int bufLen;
jjg@73: 
jjg@73:     /** The start of a line found by findLine. */
jjg@73:     protected int lineStart;
jjg@73: 
jjg@73:     /** The line number of a line found by findLine. */
jjg@73:     protected int line;
jjg@73: 
jjg@73:     /** A log for reporting errors, such as errors accessing the content. */
jjg@73:     protected AbstractLog log;
jjg@73: }