/*
* Copyright 2013 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.core.server.impl;
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.net.URL;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Scanner;
import java.util.Set;
import java.util.concurrent.ConcurrentHashMap;
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 browsers that don't support
* sourcemaps or <code><set-property name="compiler.useSourceMaps" value="true"/></code> for
* browsers that support it (e.g. Chrome), and moved your symbol map files to a location accessible
* by your server-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>.
*/
public abstract class StackTraceDeobfuscator {
/**
* Creates a deobfuscator that loads symbol and source map files under given resource path. Uses
* StackTraceObfuscator's {@link ClassLoader}.
*/
public static StackTraceDeobfuscator fromResource(String symbolMapsPath) {
final String basePath = symbolMapsPath.endsWith("/") ? symbolMapsPath : symbolMapsPath + "/";
final ClassLoader classLoader = StackTraceDeobfuscator.class.getClassLoader();
return new StackTraceDeobfuscator() {
protected InputStream openInputStream(String fileName) throws IOException {
String filePath = basePath + fileName;
InputStream inputStream = classLoader.getResourceAsStream(filePath);
if (inputStream == null) {
throw new IOException("Missing resource: " + filePath);
}
return inputStream;
}
};
}
/**
* Creates a deobfuscator that loads symbol and source map files from the given directory.
*/
public static StackTraceDeobfuscator fromFileSystem(final String symbolMapsDirectory) {
return new StackTraceDeobfuscator() {
protected InputStream openInputStream(String fileName) throws IOException {
return new FileInputStream(new File(symbolMapsDirectory, fileName));
}
};
}
/**
* Creates a deobfuscator that loads symbol and source map files beneath the given URL.
*/
public static StackTraceDeobfuscator fromUrl(final URL urlPath) {
return new StackTraceDeobfuscator() {
protected InputStream openInputStream(String fileName) throws IOException {
return new URL(urlPath, fileName).openStream();
}
};
}
/**
* A cache that maps obfuscated symbols to arbitrary non-null string values. The cache can assume
* each (strongName, symbol) pair always maps to the same value (never goes invalid), but must
* treat data as an opaque string.
*/
private static class SymbolCache {
// TODO(srogoff): This SymbolCache implementation never drops old entries. If clients ever need
// to cap memory usage even with lazy loading, consider making SymbolCache an interface.
// This could allow clients to pass their own implementation to the StackTraceDeobfuscator
// constructor, backed by a Guava Cache or other entry-evicting mapping.
private final ConcurrentHashMap<String, HashMap<String, String>> symbolMaps;
SymbolCache() {
symbolMaps = new ConcurrentHashMap<String, HashMap<String, String>>();
}
/**
* Adds some symbol data to the cache for the given strong name.
*/
void putAll(String strongName, Map<String, String> symbolMap) {
if (strongName == null || symbolMap.size() == 0) {
return;
}
symbolMaps.putIfAbsent(strongName, new HashMap<String, String>());
HashMap<String, String> existingMap = symbolMaps.get(strongName);
synchronized (existingMap) {
existingMap.putAll(symbolMap);
}
}
/**
* Returns the data for each of the specified symbols that's currently cached for the given
* strong name. There will be no entry for symbols that are not in the cache. If none of the
* symbols are cached, an empty Map is returned.
*/
Map<String, String> getAll(String strongName, Set<String> symbols) {
Map<String, String> toReturn = new HashMap<String, String>();
if (strongName == null || !symbolMaps.containsKey(strongName) || symbols.isEmpty()) {
return toReturn;
}
HashMap<String, String> existingMap = symbolMaps.get(strongName);
synchronized (existingMap) {
for (String symbol : symbols) {
if (existingMap.containsKey(symbol)) {
toReturn.put(symbol, existingMap.get(symbol));
}
}
}
return toReturn;
}
}
private static final Pattern JsniRefPattern = Pattern.compile("@?([^:]+)::([^(]+)(\\((.*)\\))?");
private static final Pattern fragmentIdPattern = Pattern.compile(".*(\\d+)\\.js");
private static final int LINE_NUMBER_UNKNOWN = -1;
private static final String SYMBOL_DATA_UNKNOWN = "";
private final Map<String, SourceMapping> sourceMaps = new HashMap<String, SourceMapping>();
private final SymbolCache symbolCache = new SymbolCache();
private boolean lazyLoad = false;
/**
* If set to {@code true}, only symbols requested to be deobfuscated are cached and the rest is
* discarded. This provides a large memory savings at the expense of occasional extra disk reads.
* Note that, this will only have effect on symbol maps that haven't been fully loaded yet.
*/
public void setLazyLoad(boolean lazyLoad) {
this.lazyLoad = lazyLoad;
}
/**
* Replaces the stack traces in the given Throwable and its causes with deobfuscated stack traces
* wherever possible.
*
* @param throwable the Throwable that needs its stack trace to be deobfuscated
* @param strongName the GWT permutation strong name
*/
public final void deobfuscateStackTrace(Throwable throwable, String strongName) {
throwable.setStackTrace(resymbolize(throwable.getStackTrace(), strongName));
if (throwable.getCause() != null) {
deobfuscateStackTrace(throwable.getCause(), strongName);
}
}
/**
* 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 final StackTraceElement[] resymbolize(StackTraceElement[] st, String strongName) {
if (st == null) {
return null;
}
// Warm the symbol cache for all symbols in this stack trace.
Set<String> requiredSymbols = new HashSet<String>();
for (StackTraceElement ste : st) {
requiredSymbols.add(ste.getMethodName());
}
loadSymbolMap(strongName, requiredSymbols);
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 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 final 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();
String symbolData = loadOneSymbol(strongName, 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.isEmpty()) {
// 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;
}
protected InputStream getSourceMapInputStream(String permutationStrongName, int fragmentNumber)
throws IOException {
return openInputStream(permutationStrongName + "_sourceMap" + fragmentNumber + ".json");
}
/**
* 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.
*
* @param permutationStrongName the GWT permutation strong name
* @return a new {@link InputStream}
*/
protected InputStream getSymbolMapInputStream(String permutationStrongName) throws IOException {
return openInputStream(permutationStrongName + ".symbolMap");
}
/**
* Opens a new {@link InputStream} for a symbol or source map file.
*
* @param fileName name of the symbol or source map file
* @return an input stream for reading the file (doesn't need to be buffered).
* @exception IOException if an I/O error occurs while creating the input stream.
*/
protected abstract InputStream openInputStream(String fileName) throws IOException;
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 String loadOneSymbol(String strongName, String symbol) {
Set<String> symbolSet = new HashSet<String>();
symbolSet.add(symbol);
Map<String, String> symbolMap = loadSymbolMap(strongName, symbolSet);
return symbolMap.get(symbol);
}
/**
* Returns a symbol map for the given strong name containing symbol data for
* all of the given required symbols. First checks the symbol cache, then
* reads from disk if any symbol is missing. If a symbol cannot be loaded for
* some reason, it will be mapped to empty string.
*/
private Map<String, String> loadSymbolMap(
String strongName, Set<String> requiredSymbols) {
Map<String, String> toReturn = symbolCache.getAll(strongName, requiredSymbols);
if (toReturn.size() == requiredSymbols.size()) {
return toReturn;
}
Set<String> symbolsLeftToFind = new HashSet<String>(requiredSymbols);
toReturn = new HashMap<String, String>();
String line;
try {
BufferedReader bin = new BufferedReader(
new InputStreamReader(getSymbolMapInputStream(strongName)));
try {
while ((line = bin.readLine()) != null && (symbolsLeftToFind.size() > 0 || !lazyLoad)) {
if (line.charAt(0) == '#') {
continue;
}
int idx = line.indexOf(',');
String symbol = line.substring(0, idx);
String symbolData = line.substring(idx + 1);
if (requiredSymbols.contains(symbol) || !lazyLoad) {
symbolsLeftToFind.remove(symbol);
toReturn.put(symbol, symbolData);
}
}
} finally {
bin.close();
}
} catch (IOException e) {
// If the symbol map isn't found or there's an I/O error reading the file, the returned
// mapping may contain some or all empty data (see below).
}
for (String symbol : symbolsLeftToFind) {
// Store the empty string in the symbolCache to show we actually looked on disk and couldn't
// find the symbols. This avoids reading disk repeatedly for symbols that can't be translated.
toReturn.put(symbol, SYMBOL_DATA_UNKNOWN);
}
symbolCache.putAll(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;
}
}