log.java

是一款用JAVA 编写的编译器 具有很强的编译功能

/*
 * Copyright 1999-2006 Sun Microsystems, Inc.  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.  Sun designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
 * CA 95054 USA or visit www.sun.com if you need additional information or
 * have any questions.
 */

package com.sun.tools.javac.util;

import java.io.*;
import java.nio.CharBuffer;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;
import javax.tools.DiagnosticListener;
import javax.tools.JavaFileObject;
import com.sun.tools.javac.code.Source;
import com.sun.tools.javac.tree.JCTree;
import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition;
import com.sun.tools.javac.util.JCDiagnostic.DiagnosticType;
import com.sun.tools.javac.util.JCDiagnostic.SimpleDiagnosticPosition;
import static com.sun.tools.javac.util.LayoutCharacters.*;

/** A class for error logs. Reports errors and warnings, and
 *  keeps track of error numbers and positions.
 *
 *  <p><b>This is NOT part of any API supported by Sun Microsystems.  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 Log {
    /** The context key for the log. */
    public static final Context.Key<Log> logKey
	= new Context.Key<Log>();

    /** The context key for the output PrintWriter. */
    public static final Context.Key<PrintWriter> outKey =
	new Context.Key<PrintWriter>();

    //@Deprecated
    public final PrintWriter errWriter;
    
    //@Deprecated
    public final PrintWriter warnWriter;
    
    //@Deprecated
    public final PrintWriter noticeWriter;

    /** The maximum number of errors/warnings that are reported.
     */
    public final int MaxErrors;
    public final int MaxWarnings;

    /** Whether or not to display the line of source containing a diagnostic.
     */
    private final boolean showSourceLine;

    /** Switch: prompt user on each error.
     */
    public boolean promptOnError;

    /** Switch: emit warning messages.
     */
    public boolean emitWarnings;

    /** Enforce mandatory warnings.
     */
    private boolean enforceMandatoryWarnings;

    /** Print stack trace on errors?
     */
    public boolean dumpOnError;

    /** Print multiple errors for same source locations.
     */
    public boolean multipleErrors;
  
    /**
     * Diagnostic listener, if provided through programmatic
     * interface to javac (JSR 199).
     */
    protected DiagnosticListener<? super JavaFileObject> diagListener;
    /**
     * Formatter for diagnostics
     */
    private DiagnosticFormatter diagFormatter;

    /**
     * Factory for diagnostics
     */
    private JCDiagnostic.Factory diags;


    /** Construct a log with given I/O redirections.
     */
    @Deprecated
    protected Log(Context context, PrintWriter errWriter, PrintWriter warnWriter, PrintWriter noticeWriter) {
	context.put(logKey, this);
	this.errWriter = errWriter;
	this.warnWriter = warnWriter;
	this.noticeWriter = noticeWriter;

	this.diags = JCDiagnostic.Factory.instance(context);

	Options options = Options.instance(context);
	this.dumpOnError = options.get("-doe") != null;
	this.promptOnError = options.get("-prompt") != null;
	this.emitWarnings = options.get("-Xlint:none") == null;
	this.MaxErrors = getIntOption(options, "-Xmaxerrs", 100);
	this.MaxWarnings = getIntOption(options, "-Xmaxwarns", 100);
	this.showSourceLine = options.get("rawDiagnostics") == null;

	this.diagFormatter = DiagnosticFormatter.instance(context);
	@SuppressWarnings("unchecked") // FIXME
	DiagnosticListener<? super JavaFileObject> diagListener =
	    context.get(DiagnosticListener.class);
	this.diagListener = diagListener;

	Source source = Source.instance(context);
	this.enforceMandatoryWarnings = source.enforceMandatoryWarnings();
    }
    // where
	private int getIntOption(Options options, String optionName, int defaultValue) {
	    String s = options.get(optionName);
	    try {
		if (s != null) return Integer.parseInt(s);
	    } catch (NumberFormatException e) {
		// silently ignore ill-formed numbers
	    }
	    return defaultValue;
	}

    /** The default writer for diagnostics
     */
    static final PrintWriter defaultWriter(Context context) {
	PrintWriter result = context.get(outKey);
	if (result == null)
	    context.put(outKey, result = new PrintWriter(System.err));
	return result;
    }

    /** Construct a log with default settings.
     */
    protected Log(Context context) {
	this(context, defaultWriter(context));
    }

    /** Construct a log with all output redirected.
     */
    protected Log(Context context, PrintWriter defaultWriter) {
	this(context, defaultWriter, defaultWriter, defaultWriter);
    }

    /** Get the Log instance for this context. */
    public static Log instance(Context context) {
	Log instance = context.get(logKey);
	if (instance == null)
	    instance = new Log(context);
	return instance;
    }

    /** The file that's currently translated.
     */
    protected JCDiagnostic.DiagnosticSource source;

    /** The number of errors encountered so far.
     */
    public int nerrors = 0;

    /** The number of warnings encountered so far.
     */
    public int nwarnings = 0;

    /** A set of all errors generated so far. This is used to avoid printing an
     *  error message more than once. For each error, a pair consisting of the
     *  source file name and source code position of the error is added to the set.
     */
    private Set<Pair<JavaFileObject, Integer>> recorded = new HashSet<Pair<JavaFileObject,Integer>>();
    
    private Map<JavaFileObject, Map<JCTree, Integer>> endPosTables;

    /** The buffer containing the file that's currently translated.
     */
    private char[] buf = null;

    /** The position in the buffer at which last error was reported
     */
    private int bp;

    /** number of the current source line; first line is 1
     */
    private int line;

    /**  buffer index of the first character of the current source line
     */
    private int lineStart;

    public boolean hasDiagnosticListener() {
        return diagListener != null;
    }
    
    public void setEndPosTable(JavaFileObject name, Map<JCTree, Integer> table) {
        if (endPosTables == null)
            endPosTables = new HashMap<JavaFileObject, Map<JCTree, Integer>>();
        endPosTables.put(name, table);
    }

    /** Re-assign source, returning previous setting.
     */
    public JavaFileObject useSource(final JavaFileObject name) {
	JavaFileObject prev = currentSource();
	if (name != prev) {
	    source = new JCDiagnostic.DiagnosticSource() {
		    public JavaFileObject getFile() {
			return name;
		    }
		    public CharSequence getName() {
			return JavacFileManager.getJavacBaseFileName(getFile());
		    }
		    public int getLineNumber(int pos) {
			return Log.this.getLineNumber(pos);
		    }
		    public int getColumnNumber(int pos) {
			return Log.this.getColumnNumber(pos);
		    }
                    public Map<JCTree, Integer> getEndPosTable() {
                        return (endPosTables == null ? null : endPosTables.get(name));
                    }
		};
	    buf = null;
	}
	return prev;
    }

    /** Re-assign source buffer for existing source name.
     */
    protected void setBuf(char[] newBuf) {
	buf = newBuf;
	bp = 0;
	lineStart = 0;
	line = 1;
    }

    protected char[] getBuf() {
	return buf;
    }

    /** Return current source name.
     */
    public JavaFileObject currentSource() {
        return source == null ? null : source.getFile();
    }

    /** Flush the logs
     */
    public void flush() {
	errWriter.flush();
	warnWriter.flush();
	noticeWriter.flush();
    }

    /** Returns true if an error needs to be reported for a given
     * source name and pos.
     */
    protected boolean shouldReport(JavaFileObject file, int pos) {
	if (multipleErrors || file == null)
	    return true;

        Pair<JavaFileObject,Integer> coords = new Pair<JavaFileObject,Integer>(file, pos);
        boolean shouldReport = !recorded.contains(coords);
        if (shouldReport)
            recorded.add(coords);
        return shouldReport;
    }        

    /** Prompt user after an error.
     */
    public void prompt() {
        if (promptOnError) {
            System.err.println(getLocalizedString("resume.abort"));
            char ch;
            try {
                while (true) {
                    switch (System.in.read()) {
                    case 'a': case 'A':
			System.exit(-1);
			return;
                    case 'r': case 'R':
                        return;
                    case 'x': case 'X':
                        throw new AssertionError("user abort");
                    default:
                    }
                }
            } catch (IOException e) {}
        }
    }

    /** Print the faulty source code line and point to the error.
     *  @param pos   Buffer index of the error position, must be on current line
     */
    private void printErrLine(int pos, PrintWriter writer) {
	if (!findLine(pos))
	    return;

	int lineEnd = lineStart;
	while (lineEnd < buf.length && buf[lineEnd] != CR && buf[lineEnd] != LF)
	    lineEnd++;
	if (lineEnd - lineStart == 0)
	    return;
	printLines(writer, new String(buf, lineStart, lineEnd - lineStart));
	for (bp = lineStart; bp < pos; bp++) {
	    writer.print((buf[bp] == '\t') ? "\t" : " ");
	}
	writer.println("^");
	writer.flush();
    }

    protected static char[] getCharContent(JavaFileObject fileObject) throws IOException {
        CharSequence cs = fileObject.getCharContent(true);
        if (cs instanceof CharBuffer) {
            return JavacFileManager.toArray((CharBuffer)cs);
        } else {
            return cs.toString().toCharArray();
        }
    }
    
    /** Find the line in the buffer that contains the current position
     * @param pos      Character offset into the buffer
     */
    private boolean findLine(int pos) {
	if (pos == Position.NOPOS || currentSource() == null)
	    return false;
	try {
	    if (buf == null) {
		buf = getCharContent(currentSource());
		lineStart = 0;
		line = 1;
	    } else if (lineStart > pos) { // messages don't come in order
		lineStart = 0;
		line = 1;
	    }