/*
* Copyright (c) 1999, 2012, 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.io.IOException;
import java.lang.ref.SoftReference;
import java.nio.CharBuffer;
import javax.tools.JavaFileObject;
import com.sun.tools.javac.file.JavacFileManager;
import com.sun.tools.javac.tree.EndPosTable;
import static com.sun.tools.javac.util.LayoutCharacters.*;
/**
* A simple abstraction of a source file, as needed for use in a diagnostic message.
* Provides access to the line and position in a line for any given character offset.
*
* <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 DiagnosticSource {
/* constant DiagnosticSource to be used when sourcefile is missing */
public static final DiagnosticSource NO_SOURCE = new DiagnosticSource() {
@Override
protected boolean findLine(int pos) {
return false;
}
};
public DiagnosticSource(JavaFileObject fo, AbstractLog log) {
this.fileObject = fo;
this.log = log;
}
private DiagnosticSource() {}
/** Return the underlying file object handled by this
* DiagnosticSource object.
*/
public JavaFileObject getFile() {
return fileObject;
}
/** Return the one-based line number associated with a given pos
* for the current source file. Zero is returned if no line exists
* for the given position.
*/
public int getLineNumber(int pos) {
try {
if (findLine(pos)) {
return line;
}
return 0;
} finally {
buf = null;
}
}
/** Return the one-based column number associated with a given pos
* for the current source file. Zero is returned if no column exists
* for the given position.
*/
public int getColumnNumber(int pos, boolean expandTabs) {
try {
if (findLine(pos)) {
int column = 0;
for (int bp = lineStart; bp < pos; bp++) {
if (bp >= bufLen) {
return 0;
}
if (buf[bp] == '\t' && expandTabs) {
column = (column / TabInc * TabInc) + TabInc;
} else {
column++;
}
}
return column + 1; // positions are one-based
}
return 0;
} finally {
buf = null;
}
}
/** Return the content of the line containing a given pos.
*/
public String getLine(int pos) {
try {
if (!findLine(pos))
return null;
int lineEnd = lineStart;
while (lineEnd < bufLen && buf[lineEnd] != CR && buf[lineEnd] != LF)
lineEnd++;
if (lineEnd - lineStart == 0)
return null;
return new String(buf, lineStart, lineEnd - lineStart);
} finally {
buf = null;
}
}
public EndPosTable getEndPosTable() {
return endPosTable;
}
public void setEndPosTable(EndPosTable t) {
if (endPosTable != null && endPosTable != t)
throw new IllegalStateException("endPosTable already set");
endPosTable = t;
}
/** Find the line in the buffer that contains the current position
* @param pos Character offset into the buffer
*/
protected boolean findLine(int pos) {
if (pos == Position.NOPOS)
return false;
try {
// try and recover buffer from soft reference cache
if (buf == null && refBuf != null)
buf = refBuf.get();
if (buf == null) {
buf = initBuf(fileObject);
lineStart = 0;
line = 1;
} else if (lineStart > pos) { // messages don't come in order
lineStart = 0;
line = 1;
}
int bp = lineStart;
while (bp < bufLen && bp < pos) {
switch (buf[bp++]) {
case CR:
if (bp < bufLen && buf[bp] == LF) bp++;
line++;
lineStart = bp;
break;
case LF:
line++;
lineStart = bp;
break;
}
}
return bp <= bufLen;
} catch (IOException e) {
log.directError("source.unavailable");
buf = new char[0];
return false;
}
}
protected char[] initBuf(JavaFileObject fileObject) throws IOException {
char[] buf;
CharSequence cs = fileObject.getCharContent(true);
if (cs instanceof CharBuffer) {
CharBuffer cb = (CharBuffer) cs;
buf = JavacFileManager.toArray(cb);
bufLen = cb.limit();
} else {
buf = cs.toString().toCharArray();
bufLen = buf.length;
}
refBuf = new SoftReference<>(buf);
return buf;
}
/** The underlying file object. */
protected JavaFileObject fileObject;
protected EndPosTable endPosTable;
/** A soft reference to the content of the file object. */
protected SoftReference<char[]> refBuf;
/** A temporary hard reference to the content of the file object. */
protected char[] buf;
/** The length of the content. */
protected int bufLen;
/** The start of a line found by findLine. */
protected int lineStart;
/** The line number of a line found by findLine. */
protected int line;
/** A log for reporting errors, such as errors accessing the content. */
protected AbstractLog log;
}