/*
* Copyright 2010 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may not
* use this file except in compliance with the License. You may obtain a copy of
* the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations under
* the License.
*/
package com.google.gwt.logging.server;
import com.google.gwt.thirdparty.debugging.sourcemap.SourceMapConsumerFactory;
import com.google.gwt.thirdparty.debugging.sourcemap.SourceMapping;
import com.google.gwt.thirdparty.debugging.sourcemap.proto.Mapping;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.HashMap;
import java.util.Map;
import java.util.Scanner;
import java.util.logging.LogRecord;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
/**
* Deobfuscates stack traces on the server side. This class requires that you have turned on
* emulated stack traces, via <code><set-property name="compiler.stackMode" value="emulated"
* /></code> in your <code>.gwt.xml</code> module file for non-Chrome browsers or
* <code><set-property name="compiler.useSourceMaps" value="true"/></code> for Chrome, and
* moved your symbol map files to a location accessible by your server sever side code. You can use
* the GWT compiler <code>-deploy</code> command line argument to specify the location of the folder
* into which the generated <code>symbolMaps</code> directory is written. By default, the final
* <code>symbolMaps</code> directory is <code>war/WEB-INF/deploy/<i>yourmodulename</i>/symbolMaps/</code>.
* Pass the resulting directory location into this class' {@link StackTraceDeobfuscator#symbolMapsDirectory}
* constructor or {@link #setSymbolMapsDirectory(String)} setter method.
*
* TODO(unnurg): Combine this code with similar code in JUnitHostImpl
*/
public class StackTraceDeobfuscator {
private static class SymbolMap extends HashMap<String, String> {
}
// From JsniRef class, which is in gwt-dev and so can't be accessed here
// TODO(unnurg) once there is a place for shared code, move this to there.
private static Pattern JsniRefPattern =
Pattern.compile("@?([^:]+)::([^(]+)(\\((.*)\\))?");
// The javadoc for StackTraceElement.getLineNumber() says it returns -1 when
// the line number is unavailable
private static final int LINE_NUMBER_UNKNOWN = -1;
Pattern fragmentIdPattern = Pattern.compile(".*(\\d+)\\.js");
protected File symbolMapsDirectory;
// Map of strongName + fragmentId to sourceMap
private Map<String, SourceMapping> sourceMaps =
new HashMap<String, SourceMapping>();
private Map<String, SymbolMap> symbolMaps =
new HashMap<String, SymbolMap>();
/**
* Constructor, which takes a <code>symbolMaps</code> directory as its argument. Symbol maps are
* generated into the location specified by the GWT compiler <code>-deploy</code> command line
* argument.
*
* @param symbolMapsDirectory the <code>symbolMaps</code> directory with, or without trailing
* directory separator character
*/
public StackTraceDeobfuscator(String symbolMapsDirectory) {
setSymbolMapsDirectory(symbolMapsDirectory);
}
/**
* Best effort resymbolization of a log record's stack trace.
*
* @param lr the log record to resymbolize
* @param strongName the GWT permutation strong name
* @return the best effort resymbolized log record
*/
public LogRecord deobfuscateLogRecord(LogRecord lr, String strongName) {
if (lr.getThrown() != null && strongName != null) {
lr.setThrown(deobfuscateThrowable(lr.getThrown(), strongName));
}
return lr;
}
/**
* Convenience method which resymbolizes an entire stack trace to extent possible.
*
* @param st the stack trace to resymbolize
* @param strongName the GWT permutation strong name
* @return a best effort resymbolized stack trace
*/
public StackTraceElement[] deobfuscateStackTrace(
StackTraceElement[] st, String strongName) {
StackTraceElement[] newSt = new StackTraceElement[st.length];
for (int i = 0; i < st.length; i++) {
newSt[i] = resymbolize(st[i], strongName);
}
return newSt;
}
/**
* Best effort resymbolization of a a single stack trace element.
*
* @param ste the stack trace element to resymbolize
* @param strongName the GWT permutation strong name
* @return the best effort resymbolized stack trace element
*/
public StackTraceElement resymbolize(StackTraceElement ste,
String strongName) {
String declaringClass = null;
String methodName = null;
String filename = null;
int lineNumber = -1;
int fragmentId = -1;
String steFilename = ste.getFileName();
SymbolMap map = loadSymbolMap(strongName);
String symbolData = map == null ? null : map.get(ste.getMethodName());
boolean sourceMapCapable = false;
int column = 1;
// column information is encoded in filename after '@' for sourceMap capable browsers
if (steFilename != null) {
int columnMarkerIndex = steFilename.indexOf("@");
if (columnMarkerIndex != -1) {
try {
column = Integer.parseInt(steFilename.substring(columnMarkerIndex + 1));
sourceMapCapable = true;
} catch (NumberFormatException nfe) {
}
steFilename = steFilename.substring(0, columnMarkerIndex);
}
}
// first use symbolMap, then refine via sourceMap if possible
if (symbolData != null) {
// jsniIdent, className, memberName, sourceUri, sourceLine, fragmentId
String[] parts = symbolData.split(",");
if (parts.length == 6) {
String[] ref = parse(
parts[0].substring(0, parts[0].lastIndexOf(')') + 1));
if (ref != null) {
declaringClass = ref[0];
methodName = ref[1];
} else {
declaringClass = ste.getClassName();
methodName = ste.getMethodName();
}
// parts[3] contains the source file URI or "Unknown"
filename = "Unknown".equals(parts[3]) ? null
: parts[3].substring(parts[3].lastIndexOf('/') + 1);
lineNumber = ste.getLineNumber();
/*
* When lineNumber is LINE_NUMBER_UNKNOWN, either because
* compiler.stackMode is not emulated or
* compiler.emulatedStack.recordLineNumbers is false, use the method
* declaration line number from the symbol map.
*/
if (lineNumber == LINE_NUMBER_UNKNOWN || (sourceMapCapable && column == -1)) {
// Safari will send line numbers, with col == -1, we need to use symbolMap in this case
lineNumber = Integer.parseInt(parts[4]);
}
fragmentId = Integer.parseInt(parts[5]);
}
}
// anonymous function, try to use <fragmentNum>.js:line to determine fragment id
if (fragmentId == -1 && steFilename != null) {
// fragment identifier encoded in filename
Matcher matcher = fragmentIdPattern.matcher(steFilename);
if (matcher.matches()) {
String fragment = matcher.group(1);
try {
fragmentId = Integer.parseInt(fragment);
} catch (Exception e) {
}
} else if (steFilename.contains(strongName)) {
// else it's <strongName>.cache.js which is the 0th fragment
fragmentId = 0;
}
}
int jsLineNumber = ste.getLineNumber();
// try to refine location via sourcemap
if (sourceMapCapable && fragmentId != -1 && column != -1) {
SourceMapping sourceMapping = loadSourceMap(strongName, fragmentId);
if (sourceMapping != null && ste.getLineNumber() > -1) {
Mapping.OriginalMapping mappingForLine = sourceMapping
.getMappingForLine(jsLineNumber, column);
if (mappingForLine != null) {
if (declaringClass == null || declaringClass.equals(ste.getClassName())) {
declaringClass = mappingForLine.getOriginalFile();
methodName = mappingForLine.getIdentifier();
}
filename = mappingForLine.getOriginalFile();
lineNumber = mappingForLine.getLineNumber();
}
}
}
if (declaringClass != null) {
return new StackTraceElement(declaringClass, methodName, filename, lineNumber);
}
// If anything goes wrong, just return the unobfuscated element
return ste;
}
public void setSymbolMapsDirectory(String symbolMapsDirectory) {
// permutations are unique, no need to clear the symbolMaps hash map
this.symbolMapsDirectory = new File(symbolMapsDirectory);
}
protected InputStream getSourceMapInputStream(String permutationStrongName, int fragmentNumber)
throws IOException {
String filename = symbolMapsDirectory.getCanonicalPath()
+ File.separatorChar + permutationStrongName + "_sourceMap" + fragmentNumber + ".json";
return new FileInputStream(filename);
}
/**
* Retrieves a new {@link InputStream} for the given permutation strong name. This implementation,
* which subclasses may override, returns a {@link InputStream} for the <code>
* <i>permutation-strong-name</i>.symbolMap</code> file in the <code>symbolMaps</code> directory.
*
* @param permutationStrongName the GWT permutation strong name
* @return a new {@link InputStream}
*/
protected InputStream getSymbolMapInputStream(String permutationStrongName)
throws IOException {
String filename = symbolMapsDirectory.getCanonicalPath()
+ File.separatorChar + permutationStrongName + ".symbolMap";
return new FileInputStream(filename);
}
private Throwable deobfuscateThrowable(Throwable old, String strongName) {
Throwable t = new Throwable(old.getMessage());
if (old.getStackTrace() != null) {
t.setStackTrace(deobfuscateStackTrace(old.getStackTrace(), strongName));
} else {
t.setStackTrace(new StackTraceElement[0]);
}
if (old.getCause() != null) {
t.initCause(deobfuscateThrowable(old.getCause(), strongName));
}
return t;
}
private SourceMapping loadSourceMap(String permutationStrongName, int fragmentId) {
SourceMapping toReturn = sourceMaps.get(permutationStrongName + fragmentId);
if (toReturn == null) {
try {
String sourceMapString = loadStreamAsString(
getSourceMapInputStream(permutationStrongName, fragmentId));
toReturn = SourceMapConsumerFactory.parse(sourceMapString);
sourceMaps.put(permutationStrongName + fragmentId, toReturn);
} catch (Exception e) {
}
}
return toReturn;
}
private String loadStreamAsString(InputStream stream) {
return new Scanner(stream).useDelimiter("\\A").next();
}
private SymbolMap loadSymbolMap(
String strongName) {
SymbolMap toReturn = symbolMaps.get(strongName);
if (toReturn != null) {
return toReturn;
}
toReturn = new SymbolMap();
String line;
try {
BufferedReader bin = new BufferedReader(
new InputStreamReader(getSymbolMapInputStream(strongName)));
try {
while ((line = bin.readLine()) != null) {
if (line.charAt(0) == '#') {
continue;
}
int idx = line.indexOf(',');
toReturn.put(new String(line.substring(0, idx)),
line.substring(idx + 1));
}
} finally {
bin.close();
}
} catch (IOException e) {
// use empty symbol map to avoid repeated lookups
toReturn = new SymbolMap();
}
symbolMaps.put(strongName, toReturn);
return toReturn;
}
/**
* Extracts the declaring class and method name from a JSNI ref, or null if the information cannot
* be extracted.
*
* @param refString symbol map reference string
* @return a string array contains the declaring class and method name, or null when the regex
* match fails
* @see com.google.gwt.dev.util.JsniRef
*/
private String[] parse(String refString) {
Matcher matcher = JsniRefPattern.matcher(refString);
if (!matcher.matches()) {
return null;
}
String className = matcher.group(1);
String memberName = matcher.group(2);
String[] toReturn = new String[]{className, memberName};
return toReturn;
}
}