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/*
* YUI Compressor
* http://developer.yahoo.com/yui/compressor/
* Author: Julien Lecomte - http://www.julienlecomte.net/
* Copyright (c) 2011 Yahoo! Inc. All rights reserved.
* The copyrights embodied in the content of this file are licensed
* by Yahoo! Inc. under the BSD (revised) open source license.
*/
package com.yahoo.platform.yui.compressor;
import org.mozilla.javascript.*;
import java.io.IOException;
import java.io.Reader;
import java.io.Writer;
import java.util.*;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class JavaScriptCompressor {
static final ArrayList ones;
static final ArrayList twos;
static final ArrayList threes;
static final Set builtin = new HashSet();
static final Map literals = new HashMap();
static final Set reserved = new HashSet();
static {
// This list contains all the 3 characters or less built-in global
// symbols available in a browser. Please add to this list if you
// see anything missing.
builtin.add("NaN");
builtin.add("top");
ones = new ArrayList();
for (char c = 'a'; c <= 'z'; c++)
ones.add(Character.toString(c));
for (char c = 'A'; c <= 'Z'; c++)
ones.add(Character.toString(c));
twos = new ArrayList();
for (int i = 0; i < ones.size(); i++) {
String one = (String) ones.get(i);
for (char c = 'a'; c <= 'z'; c++)
twos.add(one + Character.toString(c));
for (char c = 'A'; c <= 'Z'; c++)
twos.add(one + Character.toString(c));
for (char c = '0'; c <= '9'; c++)
twos.add(one + Character.toString(c));
}
threes = new ArrayList();
for (int i = 0; i < twos.size(); i++) {
String two = (String) twos.get(i);
for (char c = 'a'; c <= 'z'; c++)
threes.add(two + Character.toString(c));
for (char c = 'A'; c <= 'Z'; c++)
threes.add(two + Character.toString(c));
for (char c = '0'; c <= '9'; c++)
threes.add(two + Character.toString(c));
}
// Remove two-letter JavaScript reserved words and built-in globals...
twos.remove("as");
twos.remove("is");
twos.remove("do");
twos.remove("if");
twos.remove("in");
twos.removeAll(builtin);
// Remove three-letter JavaScript reserved words and built-in globals...
threes.remove("for");
threes.remove("int");
threes.remove("new");
threes.remove("try");
threes.remove("use");
threes.remove("var");
threes.removeAll(builtin);
// That's up to ((26+26)*(1+(26+26+10)))*(1+(26+26+10))-8
// (206,380 symbols per scope)
// The following list comes from org/mozilla/javascript/Decompiler.java...
literals.put(new Integer(Token.GET), "get ");
literals.put(new Integer(Token.SET), "set ");
literals.put(new Integer(Token.TRUE), "true");
literals.put(new Integer(Token.FALSE), "false");
literals.put(new Integer(Token.NULL), "null");
literals.put(new Integer(Token.THIS), "this");
literals.put(new Integer(Token.FUNCTION), "function");
literals.put(new Integer(Token.COMMA), ",");
literals.put(new Integer(Token.LC), "{");
literals.put(new Integer(Token.RC), "}");
literals.put(new Integer(Token.LP), "(");
literals.put(new Integer(Token.RP), ")");
literals.put(new Integer(Token.LB), "[");
literals.put(new Integer(Token.RB), "]");
literals.put(new Integer(Token.DOT), ".");
literals.put(new Integer(Token.NEW), "new ");
literals.put(new Integer(Token.DELPROP), "delete ");
literals.put(new Integer(Token.IF), "if");
literals.put(new Integer(Token.ELSE), "else");
literals.put(new Integer(Token.FOR), "for");
literals.put(new Integer(Token.IN), " in ");
literals.put(new Integer(Token.WITH), "with");
literals.put(new Integer(Token.WHILE), "while");
literals.put(new Integer(Token.DO), "do");
literals.put(new Integer(Token.TRY), "try");
literals.put(new Integer(Token.CATCH), "catch");
literals.put(new Integer(Token.FINALLY), "finally");
literals.put(new Integer(Token.THROW), "throw");
literals.put(new Integer(Token.SWITCH), "switch");
literals.put(new Integer(Token.BREAK), "break");
literals.put(new Integer(Token.CONTINUE), "continue");
literals.put(new Integer(Token.CASE), "case");
literals.put(new Integer(Token.DEFAULT), "default");
literals.put(new Integer(Token.RETURN), "return");
literals.put(new Integer(Token.VAR), "var ");
literals.put(new Integer(Token.SEMI), ";");
literals.put(new Integer(Token.ASSIGN), "=");
literals.put(new Integer(Token.ASSIGN_ADD), "+=");
literals.put(new Integer(Token.ASSIGN_SUB), "-=");
literals.put(new Integer(Token.ASSIGN_MUL), "*=");
literals.put(new Integer(Token.ASSIGN_DIV), "/=");
literals.put(new Integer(Token.ASSIGN_MOD), "%=");
literals.put(new Integer(Token.ASSIGN_BITOR), "|=");
literals.put(new Integer(Token.ASSIGN_BITXOR), "^=");
literals.put(new Integer(Token.ASSIGN_BITAND), "&=");
literals.put(new Integer(Token.ASSIGN_LSH), "<<=");
literals.put(new Integer(Token.ASSIGN_RSH), ">>=");
literals.put(new Integer(Token.ASSIGN_URSH), ">>>=");
literals.put(new Integer(Token.HOOK), "?");
literals.put(new Integer(Token.OBJECTLIT), ":");
literals.put(new Integer(Token.COLON), ":");
literals.put(new Integer(Token.OR), "||");
literals.put(new Integer(Token.AND), "&&");
literals.put(new Integer(Token.BITOR), "|");
literals.put(new Integer(Token.BITXOR), "^");
literals.put(new Integer(Token.BITAND), "&");
literals.put(new Integer(Token.SHEQ), "===");
literals.put(new Integer(Token.SHNE), "!==");
literals.put(new Integer(Token.EQ), "==");
literals.put(new Integer(Token.NE), "!=");
literals.put(new Integer(Token.LE), "<=");
literals.put(new Integer(Token.LT), "<");
literals.put(new Integer(Token.GE), ">=");
literals.put(new Integer(Token.GT), ">");
literals.put(new Integer(Token.INSTANCEOF), " instanceof ");
literals.put(new Integer(Token.LSH), "<<");
literals.put(new Integer(Token.RSH), ">>");
literals.put(new Integer(Token.URSH), ">>>");
literals.put(new Integer(Token.TYPEOF), "typeof");
literals.put(new Integer(Token.VOID), "void ");
literals.put(new Integer(Token.CONST), "const ");
literals.put(new Integer(Token.NOT), "!");
literals.put(new Integer(Token.BITNOT), "~");
literals.put(new Integer(Token.POS), "+");
literals.put(new Integer(Token.NEG), "-");
literals.put(new Integer(Token.INC), "++");
literals.put(new Integer(Token.DEC), "--");
literals.put(new Integer(Token.ADD), "+");
literals.put(new Integer(Token.SUB), "-");
literals.put(new Integer(Token.MUL), "*");
literals.put(new Integer(Token.DIV), "/");
literals.put(new Integer(Token.MOD), "%");
literals.put(new Integer(Token.COLONCOLON), "::");
literals.put(new Integer(Token.DOTDOT), "..");
literals.put(new Integer(Token.DOTQUERY), ".(");
literals.put(new Integer(Token.XMLATTR), "@");
literals.put(new Integer(Token.LET), "let ");
literals.put(new Integer(Token.YIELD), "yield ");
// See http://developer.mozilla.org/en/docs/Core_JavaScript_1.5_Reference:Reserved_Words
// JavaScript 1.5 reserved words
reserved.add("break");
reserved.add("case");
reserved.add("catch");
reserved.add("continue");
reserved.add("default");
reserved.add("delete");
reserved.add("do");
reserved.add("else");
reserved.add("finally");
reserved.add("for");
reserved.add("function");
reserved.add("if");
reserved.add("in");
reserved.add("instanceof");
reserved.add("new");
reserved.add("return");
reserved.add("switch");
reserved.add("this");
reserved.add("throw");
reserved.add("try");
reserved.add("typeof");
reserved.add("var");
reserved.add("void");
reserved.add("while");
reserved.add("with");
// Words reserved for future use
reserved.add("abstract");
reserved.add("boolean");
reserved.add("byte");
reserved.add("char");
reserved.add("class");
reserved.add("const");
reserved.add("debugger");
reserved.add("double");
reserved.add("enum");
reserved.add("export");
reserved.add("extends");
reserved.add("final");
reserved.add("float");
reserved.add("goto");
reserved.add("implements");
reserved.add("import");
reserved.add("int");
reserved.add("interface");
reserved.add("long");
reserved.add("native");
reserved.add("package");
reserved.add("private");
reserved.add("protected");
reserved.add("public");
reserved.add("short");
reserved.add("static");
reserved.add("super");
reserved.add("synchronized");
reserved.add("throws");
reserved.add("transient");
reserved.add("volatile");
// These are not reserved, but should be taken into account
// in isValidIdentifier (See jslint source code)
reserved.add("arguments");
reserved.add("eval");
reserved.add("true");
reserved.add("false");
reserved.add("Infinity");
reserved.add("NaN");
reserved.add("null");
reserved.add("undefined");
}
private static int countChar(String haystack, char needle) {
int idx = 0;
int count = 0;
int length = haystack.length();
while (idx < length) {
char c = haystack.charAt(idx++);
if (c == needle) {
count++;
}
}
return count;
}
private static int printSourceString(String source, int offset, StringBuffer sb) {
int length = source.charAt(offset);
++offset;
if ((0x8000 & length) != 0) {
length = ((0x7FFF & length) << 16) | source.charAt(offset);
++offset;
}
if (sb != null) {
String str = source.substring(offset, offset + length);
sb.append(str);
}
return offset + length;
}
private static int printSourceNumber(String source,
int offset, StringBuffer sb) {
double number = 0.0;
char type = source.charAt(offset);
++offset;
if (type == 'S') {
if (sb != null) {
number = source.charAt(offset);
}
++offset;
} else if (type == 'J' || type == 'D') {
if (sb != null) {
long lbits;
lbits = (long) source.charAt(offset) << 48;
lbits |= (long) source.charAt(offset + 1) << 32;
lbits |= (long) source.charAt(offset + 2) << 16;
lbits |= (long) source.charAt(offset + 3);
if (type == 'J') {
number = lbits;
} else {
number = Double.longBitsToDouble(lbits);
}
}
offset += 4;
} else {
// Bad source
throw new RuntimeException();
}
if (sb != null) {
sb.append(ScriptRuntime.numberToString(number, 10));
}
return offset;
}
private static ArrayList parse(Reader in, ErrorReporter reporter)
throws IOException, EvaluatorException {
CompilerEnvirons env = new CompilerEnvirons();
env.setLanguageVersion(Context.VERSION_1_7);
Parser parser = new Parser(env, reporter);
parser.parse(in, null, 1);
String source = parser.getEncodedSource();
int offset = 0;
int length = (source != null) ? source.length() : 0;
ArrayList tokens = new ArrayList();
StringBuffer sb = new StringBuffer();
while (offset < length) {
int tt = source.charAt(offset++);
switch (tt) {
case Token.CONDCOMMENT:
case Token.KEEPCOMMENT:
case Token.NAME:
case Token.REGEXP:
case Token.STRING:
sb.setLength(0);
offset = printSourceString(source, offset, sb);
tokens.add(new JavaScriptToken(tt, sb.toString()));
break;
case Token.NUMBER:
sb.setLength(0);
offset = printSourceNumber(source, offset, sb);
tokens.add(new JavaScriptToken(tt, sb.toString()));
break;
default:
String literal = (String) literals.get(new Integer(tt));
if (literal != null) {
tokens.add(new JavaScriptToken(tt, literal));
}
break;
}
}
return tokens;
}
private static void processStringLiterals(ArrayList tokens, boolean merge) {
String tv;
int i, length = tokens.size();
JavaScriptToken token, prevToken, nextToken;
if (merge) {
// Concatenate string literals that are being appended wherever
// it is safe to do so. Note that we take care of the cases:
// "a" + "b".toUpperCase()
// "a" + "bcd"[i]
for (i = 1; i < length - 1; i++) {
token = (JavaScriptToken) tokens.get(i);
if (token.getType() == Token.ADD) {
prevToken = (JavaScriptToken) tokens.get(i - 1);
nextToken = (JavaScriptToken) tokens.get(i + 1);
if (prevToken.getType() == Token.STRING &&
nextToken.getType() == Token.STRING ) {
if (i < length - 2) {
JavaScriptToken nextNextToken = (JavaScriptToken) tokens.get(i + 2);
if (nextNextToken.getType() == Token.DOT ||
nextNextToken.getType() == Token.LB) {
i += 3;
continue;
}
}
tokens.set(i - 1, new JavaScriptToken(Token.STRING,
prevToken.getValue() + nextToken.getValue()));
tokens.remove(i + 1);
tokens.remove(i);
i--;
length -= 2;
}
}
}
}
// Second pass...
for (i = 0; i < length; i++) {
token = (JavaScriptToken) tokens.get(i);
if (token.getType() == Token.STRING) {
tv = token.getValue();
// Finally, add the quoting characters and escape the string. We use
// the quoting character that minimizes the amount of escaping to save
// a few additional bytes.
char quotechar;
int singleQuoteCount = countChar(tv, '\'');
int doubleQuoteCount = countChar(tv, '"');
if (doubleQuoteCount <= singleQuoteCount) {
quotechar = '"';
} else {
quotechar = '\'';
}
tv = quotechar + escapeString(tv, quotechar) + quotechar;
// String concatenation transforms the old script scheme:
// '<scr'+'ipt ...><'+'/script>'
// into the following:
// '<script ...></script>'
// which breaks if this code is embedded inside an HTML document.
// Since this is not the right way to do this, let's fix the code by
// transforming all "</script" into "<\/script"
if (tv.indexOf("</script") >= 0) {
tv = tv.replaceAll("<\\/script", "<\\\\/script");
}
tokens.set(i, new JavaScriptToken(Token.STRING, tv));
}
}
}
// Add necessary escaping that was removed in Rhino's tokenizer.
private static String escapeString(String s, char quotechar) {
assert quotechar == '"' || quotechar == '\'';
if (s == null) {
return null;
}
StringBuffer sb = new StringBuffer();
for (int i = 0, L = s.length(); i < L; i++) {
int c = s.charAt(i);
if (c == quotechar) {
sb.append("\\");
}
sb.append((char) c);
}
return sb.toString();
}
/*
* Simple check to see whether a string is a valid identifier name.
* If a string matches this pattern, it means it IS a valid
* identifier name. If a string doesn't match it, it does not
* necessarily mean it is not a valid identifier name.
*/
private static final Pattern SIMPLE_IDENTIFIER_NAME_PATTERN = Pattern.compile("^[a-zA-Z_][a-zA-Z0-9_]*$");
private static boolean isValidIdentifier(String s) {
Matcher m = SIMPLE_IDENTIFIER_NAME_PATTERN.matcher(s);
return (m.matches() && !reserved.contains(s));
}
/*
* Transforms obj["foo"] into obj.foo whenever possible, saving 3 bytes.
*/
private static void optimizeObjectMemberAccess(ArrayList tokens) {
String tv;
int i, length;
JavaScriptToken token;
for (i = 0, length = tokens.size(); i < length; i++) {
if (((JavaScriptToken) tokens.get(i)).getType() == Token.LB &&
i > 0 && i < length - 2 &&
((JavaScriptToken) tokens.get(i - 1)).getType() == Token.NAME &&
((JavaScriptToken) tokens.get(i + 1)).getType() == Token.STRING &&
((JavaScriptToken) tokens.get(i + 2)).getType() == Token.RB) {
token = (JavaScriptToken) tokens.get(i + 1);
tv = token.getValue();
tv = tv.substring(1, tv.length() - 1);
if (isValidIdentifier(tv)) {
tokens.set(i, new JavaScriptToken(Token.DOT, "."));
tokens.set(i + 1, new JavaScriptToken(Token.NAME, tv));
tokens.remove(i + 2);
i = i + 2;
length = length - 1;
}
}
}
}
/*
* Transforms 'foo': ... into foo: ... whenever possible, saving 2 bytes.
*/
private static void optimizeObjLitMemberDecl(ArrayList tokens) {
String tv;
int i, length;
JavaScriptToken token;
for (i = 0, length = tokens.size(); i < length; i++) {
if (((JavaScriptToken) tokens.get(i)).getType() == Token.OBJECTLIT &&
i > 0 && ((JavaScriptToken) tokens.get(i - 1)).getType() == Token.STRING) {
token = (JavaScriptToken) tokens.get(i - 1);
tv = token.getValue();
tv = tv.substring(1, tv.length() - 1);
if (isValidIdentifier(tv)) {
tokens.set(i - 1, new JavaScriptToken(Token.NAME, tv));
}
}
}
}
private ErrorReporter logger;
private boolean munge;
private boolean verbose;
private boolean preserveUnknownHints;
private static final int BUILDING_SYMBOL_TREE = 1;
private static final int CHECKING_SYMBOL_TREE = 2;
private int mode;
private int offset;
private int braceNesting;
private ArrayList tokens;
private Stack scopes = new Stack();
private ScriptOrFnScope globalScope = new ScriptOrFnScope(-1, null);
private Hashtable indexedScopes = new Hashtable();
public JavaScriptCompressor(Reader in, ErrorReporter reporter)
throws IOException, EvaluatorException {
this.logger = reporter;
this.tokens = parse(in, reporter);
}
public void compress(Writer out, int linebreak, boolean munge, boolean verbose,
boolean preserveAllSemiColons, boolean disableOptimizations)
throws IOException {
compress(out, null, linebreak, munge, verbose, preserveAllSemiColons,
disableOptimizations, false);
}
public void compress(Writer out, Writer mungemap, int linebreak, boolean munge, boolean verbose,
boolean preserveAllSemiColons, boolean disableOptimizations, boolean preserveUnknownHints)
throws IOException {
this.munge = munge;
this.verbose = verbose;
this.preserveUnknownHints = preserveUnknownHints;
processStringLiterals(this.tokens, !disableOptimizations);
if (!disableOptimizations) {
optimizeObjectMemberAccess(this.tokens);
optimizeObjLitMemberDecl(this.tokens);
}
buildSymbolTree();
// DO NOT TOUCH this.tokens BETWEEN THESE TWO PHASES (BECAUSE OF this.indexedScopes)
mungeSymboltree();
StringBuffer sb = printSymbolTree(linebreak, preserveAllSemiColons);
out.write(sb.toString());
if (mungemap != null) {
printMungeMapping(mungemap);
}
}
private ScriptOrFnScope getCurrentScope() {
return (ScriptOrFnScope) scopes.peek();
}
private void enterScope(ScriptOrFnScope scope) {
scopes.push(scope);
}
private void leaveCurrentScope() {
scopes.pop();
}
private JavaScriptToken consumeToken() {
return (JavaScriptToken) tokens.get(offset++);
}
private JavaScriptToken getToken(int delta) {
try {
return (JavaScriptToken) tokens.get(offset + delta);
} catch(IndexOutOfBoundsException ex) {
return null;
}
}
/*
* Returns the identifier for the specified symbol defined in
* the specified scope or in any scope above it. Returns null
* if this symbol does not have a corresponding identifier.
*/
private JavaScriptIdentifier getIdentifier(String symbol, ScriptOrFnScope scope) {
JavaScriptIdentifier identifier;
while (scope != null) {
identifier = scope.getIdentifier(symbol);
if (identifier != null) {
return identifier;
}
scope = scope.getParentScope();
}
return null;
}
/*
* If either 'eval' or 'with' is used in a local scope, we must make
* sure that all containing local scopes don't get munged. Otherwise,
* the obfuscation would potentially introduce bugs.
*/
private void protectScopeFromObfuscation(ScriptOrFnScope scope) {
assert scope != null;
if (scope == globalScope) {
// The global scope does not get obfuscated,
// so we don't need to worry about it...
return;
}
// Find the highest local scope containing the specified scope.
while (scope.getParentScope() != globalScope) {
scope = scope.getParentScope();
}
assert scope.getParentScope() == globalScope;
scope.preventMunging();
}
private String getDebugString(int max) {
assert max > 0;
StringBuffer result = new StringBuffer();
int start = Math.max(offset - max, 0);
int end = Math.min(offset + max, tokens.size());
for (int i = start; i < end; i++) {
JavaScriptToken token = (JavaScriptToken) tokens.get(i);
if (i == offset - 1) {
result.append(" ---> ");
}
result.append(token.getValue());
if (i == offset - 1) {
result.append(" <--- ");
}
}
return result.toString();
}
private void warn(String message, boolean showDebugString) {
if (verbose) {
if (showDebugString) {
message = message + "\n" + getDebugString(10);
}
logger.warning(message, null, -1, null, -1);
}
}
private void parseFunctionDeclaration() {
String symbol;
JavaScriptToken token;
ScriptOrFnScope currentScope, fnScope;
JavaScriptIdentifier identifier;
currentScope = getCurrentScope();
token = consumeToken();
if (token.getType() == Token.NAME) {
if (mode == BUILDING_SYMBOL_TREE) {
// Get the name of the function and declare it in the current scope.
symbol = token.getValue();
if (currentScope.getIdentifier(symbol) != null) {
warn("The function " + symbol + " has already been declared in the same scope...", true);
}
currentScope.declareIdentifier(symbol);
}
token = consumeToken();
}
assert token.getType() == Token.LP;
if (mode == BUILDING_SYMBOL_TREE) {
fnScope = new ScriptOrFnScope(braceNesting, currentScope);
indexedScopes.put(new Integer(offset), fnScope);
} else {
fnScope = (ScriptOrFnScope) indexedScopes.get(new Integer(offset));
}
// Parse function arguments.
int argpos = 0;
while ((token = consumeToken()).getType() != Token.RP) {
assert token.getType() == Token.NAME ||
token.getType() == Token.COMMA;
if (token.getType() == Token.NAME && mode == BUILDING_SYMBOL_TREE) {
symbol = token.getValue();
identifier = fnScope.declareIdentifier(symbol);
if (symbol.equals("$super") && argpos == 0) {
// Exception for Prototype 1.6...
identifier.preventMunging();
}
argpos++;
}
}
token = consumeToken();
assert token.getType() == Token.LC;
braceNesting++;
token = getToken(0);
if (token.getType() == Token.STRING &&
getToken(1).getType() == Token.SEMI) {
// This is a hint. Hints are empty statements that look like
// "localvar1:nomunge, localvar2:nomunge"; They allow developers
// to prevent specific symbols from getting obfuscated (some heretic
// implementations, such as Prototype 1.6, require specific variable
// names, such as $super for example, in order to work appropriately.
// Note: right now, only "nomunge" is supported in the right hand side
// of a hint. However, in the future, the right hand side may contain
// other values.
consumeToken();
String hints = token.getValue();
// Remove the leading and trailing quotes...
hints = hints.substring(1, hints.length() - 1).trim();
StringTokenizer st1 = new StringTokenizer(hints, ",");
while (st1.hasMoreTokens()) {
String hint = st1.nextToken();
int idx = hint.indexOf(':');
if (idx <= 0 || idx >= hint.length() - 1) {
if (mode == BUILDING_SYMBOL_TREE && (! preserveUnknownHints)) {
// No need to report the error twice, hence the test...
warn("Not a YUICompressor hint: " + hint, true);
}
break;
}
String variableName = hint.substring(0, idx).trim();
String variableType = hint.substring(idx + 1).trim();
if (mode == BUILDING_SYMBOL_TREE) {
fnScope.addHint(variableName, variableType);
} else if (mode == CHECKING_SYMBOL_TREE) {
identifier = fnScope.getIdentifier(variableName);
if (identifier != null) {
if (variableType.equals("nomunge")) {
identifier.preventMunging();
} else {
warn("Unsupported hint value: " + hint, true);
}
} else {
warn("Hint refers to an unknown identifier: " + hint, true);
}
}
}
}
parseScope(fnScope);
}
private void parseCatch() {
String symbol;
JavaScriptToken token;
ScriptOrFnScope currentScope;
JavaScriptIdentifier identifier;
token = getToken(-1);
assert token.getType() == Token.CATCH;
token = consumeToken();
assert token.getType() == Token.LP;
token = consumeToken();
assert token.getType() == Token.NAME;
symbol = token.getValue();
currentScope = getCurrentScope();
if (mode == BUILDING_SYMBOL_TREE) {
// We must declare the exception identifier in the containing function
// scope to avoid errors related to the obfuscation process. No need to
// display a warning if the symbol was already declared here...
currentScope.declareIdentifier(symbol);
} else {
identifier = getIdentifier(symbol, currentScope);
identifier.incrementRefcount();
}
token = consumeToken();
assert token.getType() == Token.RP;
}
private void parseExpression() {
// Parse the expression until we encounter a comma or a semi-colon
// in the same brace nesting, bracket nesting and paren nesting.
// Parse functions if any...
String symbol;
JavaScriptToken token;
ScriptOrFnScope currentScope;
JavaScriptIdentifier identifier;
int expressionBraceNesting = braceNesting;
int bracketNesting = 0;
int parensNesting = 0;
int length = tokens.size();
while (offset < length) {
token = consumeToken();
currentScope = getCurrentScope();
switch (token.getType()) {
case Token.SEMI:
case Token.COMMA:
if (braceNesting == expressionBraceNesting &&
bracketNesting == 0 &&
parensNesting == 0) {
return;
}
break;
case Token.FUNCTION:
parseFunctionDeclaration();
break;
case Token.LC:
braceNesting++;
break;
case Token.RC:
braceNesting--;
assert braceNesting >= expressionBraceNesting;
break;
case Token.LB:
bracketNesting++;
break;
case Token.RB:
bracketNesting--;
break;
case Token.LP:
parensNesting++;
break;
case Token.RP:
parensNesting--;
break;
case Token.CONDCOMMENT:
if (mode == BUILDING_SYMBOL_TREE) {
protectScopeFromObfuscation(currentScope);
warn("Using JScript conditional comments is not recommended." + (munge ? " Moreover, using JScript conditional comments reduces the level of compression!" : ""), true);
}
break;
case Token.NAME:
symbol = token.getValue();
if (mode == BUILDING_SYMBOL_TREE) {
if (symbol.equals("eval")) {
protectScopeFromObfuscation(currentScope);
warn("Using 'eval' is not recommended." + (munge ? " Moreover, using 'eval' reduces the level of compression!" : ""), true);
}
} else if (mode == CHECKING_SYMBOL_TREE) {
if ((offset < 2 ||
(getToken(-2).getType() != Token.DOT &&
getToken(-2).getType() != Token.GET &&
getToken(-2).getType() != Token.SET)) &&
getToken(0).getType() != Token.OBJECTLIT) {
identifier = getIdentifier(symbol, currentScope);
if (identifier == null) {
if (symbol.length() <= 3 && !builtin.contains(symbol)) {
// Here, we found an undeclared and un-namespaced symbol that is
// 3 characters or less in length. Declare it in the global scope.
// We don't need to declare longer symbols since they won't cause
// any conflict with other munged symbols.
globalScope.declareIdentifier(symbol);
// I removed the warning since was only being done when
// for identifiers 3 chars or less, and was just causing
// noise for people who happen to rely on an externally
// declared variable that happen to be that short. We either
// should always warn or never warn -- the fact that we
// declare the short symbols in the global space doesn't
// change anything.
// warn("Found an undeclared symbol: " + symbol, true);
}
} else {
identifier.incrementRefcount();
}
}
}
break;
}
}
}
private void parseScope(ScriptOrFnScope scope) {
String symbol;
JavaScriptToken token;
JavaScriptIdentifier identifier;
int length = tokens.size();
enterScope(scope);
while (offset < length) {
token = consumeToken();
switch (token.getType()) {
case Token.VAR:
if (mode == BUILDING_SYMBOL_TREE && scope.incrementVarCount() > 1) {
warn("Try to use a single 'var' statement per scope.", true);
}
/* FALLSTHROUGH */
case Token.CONST:
// The var keyword is followed by at least one symbol name.
// If several symbols follow, they are comma separated.
for (; ;) {
token = consumeToken();
assert token.getType() == Token.NAME;
if (mode == BUILDING_SYMBOL_TREE) {
symbol = token.getValue();
if (scope.getIdentifier(symbol) == null) {
scope.declareIdentifier(symbol);
} else {
warn("The variable " + symbol + " has already been declared in the same scope...", true);
}
}
token = getToken(0);
assert token.getType() == Token.SEMI ||
token.getType() == Token.ASSIGN ||
token.getType() == Token.COMMA ||
token.getType() == Token.IN;
if (token.getType() == Token.IN) {
break;
} else {
parseExpression();
token = getToken(-1);
if (token.getType() == Token.SEMI) {
break;
}
}
}
break;
case Token.FUNCTION:
parseFunctionDeclaration();
break;
case Token.LC:
braceNesting++;
break;
case Token.RC:
braceNesting--;
assert braceNesting >= scope.getBraceNesting();
if (braceNesting == scope.getBraceNesting()) {
leaveCurrentScope();
return;
}
break;
case Token.WITH:
if (mode == BUILDING_SYMBOL_TREE) {
// Inside a 'with' block, it is impossible to figure out
// statically whether a symbol is a local variable or an
// object member. As a consequence, the only thing we can
// do is turn the obfuscation off for the highest scope
// containing the 'with' block.
protectScopeFromObfuscation(scope);
warn("Using 'with' is not recommended." + (munge ? " Moreover, using 'with' reduces the level of compression!" : ""), true);
}
break;
case Token.CATCH:
parseCatch();
break;
case Token.CONDCOMMENT:
if (mode == BUILDING_SYMBOL_TREE) {
protectScopeFromObfuscation(scope);
warn("Using JScript conditional comments is not recommended." + (munge ? " Moreover, using JScript conditional comments reduces the level of compression." : ""), true);
}
break;
case Token.NAME:
symbol = token.getValue();
if (mode == BUILDING_SYMBOL_TREE) {
if (symbol.equals("eval")) {
protectScopeFromObfuscation(scope);
warn("Using 'eval' is not recommended." + (munge ? " Moreover, using 'eval' reduces the level of compression!" : ""), true);
}
} else if (mode == CHECKING_SYMBOL_TREE) {
if ((offset < 2 || getToken(-2).getType() != Token.DOT) &&
getToken(0).getType() != Token.OBJECTLIT) {
identifier = getIdentifier(symbol, scope);
if (identifier == null) {
if (symbol.length() <= 3 && !builtin.contains(symbol)) {
// Here, we found an undeclared and un-namespaced symbol that is
// 3 characters or less in length. Declare it in the global scope.
// We don't need to declare longer symbols since they won't cause
// any conflict with other munged symbols.
globalScope.declareIdentifier(symbol);
// warn("Found an undeclared symbol: " + symbol, true);
}
} else {
identifier.incrementRefcount();
}
}
}
break;
}
}
}
private void buildSymbolTree() {
offset = 0;
braceNesting = 0;
scopes.clear();
indexedScopes.clear();
indexedScopes.put(new Integer(0), globalScope);
mode = BUILDING_SYMBOL_TREE;
parseScope(globalScope);
}
private void mungeSymboltree() {
if (!munge) {
return;
}
// One problem with obfuscation resides in the use of undeclared
// and un-namespaced global symbols that are 3 characters or less
// in length. Here is an example:
//
// var declaredGlobalVar;
//
// function declaredGlobalFn() {
// var localvar;
// localvar = abc; // abc is an undeclared global symbol
// }
//
// In the example above, there is a slim chance that localvar may be
// munged to 'abc', conflicting with the undeclared global symbol
// abc, creating a potential bug. The following code detects such
// global symbols. This must be done AFTER the entire file has been
// parsed, and BEFORE munging the symbol tree. Note that declaring
// extra symbols in the global scope won't hurt.
//
// Note: Since we go through all the tokens to do this, we also use
// the opportunity to count how many times each identifier is used.
offset = 0;
braceNesting = 0;
scopes.clear();
mode = CHECKING_SYMBOL_TREE;
parseScope(globalScope);
globalScope.munge();
}
private StringBuffer printSymbolTree(int linebreakpos, boolean preserveAllSemiColons)
throws IOException {
offset = 0;
braceNesting = 0;
scopes.clear();
String symbol;
JavaScriptToken token;
JavaScriptToken lastToken = getToken(0);
ScriptOrFnScope currentScope;
JavaScriptIdentifier identifier;
int length = tokens.size();
StringBuffer result = new StringBuffer();
int linestartpos = 0;
enterScope(globalScope);
while (offset < length) {
token = consumeToken();
symbol = token.getValue();
currentScope = getCurrentScope();
switch (token.getType()) {
case Token.GET:
case Token.SET:
lastToken = token;
case Token.NAME:
if (offset >= 2 && getToken(-2).getType() == Token.DOT ||
getToken(0).getType() == Token.OBJECTLIT) {
result.append(symbol);
} else {
identifier = getIdentifier(symbol, currentScope);
if (identifier != null) {
if (identifier.getMungedValue() != null) {
result.append(identifier.getMungedValue());
} else {
result.append(symbol);
}
if (currentScope != globalScope && identifier.getRefcount() == 0) {
warn("The symbol " + symbol + " is declared but is apparently never used.\nThis code can probably be written in a more compact way.", true);
}
} else {
result.append(symbol);
}
}
break;
case Token.REGEXP:
case Token.STRING:
result.append(symbol);
break;
case Token.NUMBER:
if (getToken(0).getType() == Token.DOT) {
// calling methods on int requires a leading dot so JS doesn't
// treat the method as the decimal component of a float
result.append('(');
result.append(symbol);
result.append(')');
} else {
result.append(symbol);
}
break;
case Token.ADD:
case Token.SUB:
result.append((String) literals.get(new Integer(token.getType())));
if (offset < length) {
token = getToken(0);
if (token.getType() == Token.INC ||
token.getType() == Token.DEC ||
token.getType() == Token.ADD ||
token.getType() == Token.DEC) {
// Handle the case x +/- ++/-- y
// We must keep a white space here. Otherwise, x +++ y would be
// interpreted as x ++ + y by the compiler, which is a bug (due
// to the implicit assignment being done on the wrong variable)
result.append(' ');
} else if (token.getType() == Token.POS && getToken(-1).getType() == Token.ADD ||
token.getType() == Token.NEG && getToken(-1).getType() == Token.SUB) {
// Handle the case x + + y and x - - y
result.append(' ');
}
}
break;
case Token.FUNCTION:
if (lastToken.getType() != Token.GET && lastToken.getType() != Token.SET) {
result.append("function");
}
lastToken = token;
token = consumeToken();
if (token.getType() == Token.NAME) {
result.append(' ');
symbol = token.getValue();
identifier = getIdentifier(symbol, currentScope);
assert identifier != null;
if (identifier.getMungedValue() != null) {
result.append(identifier.getMungedValue());
} else {
result.append(symbol);
}
if (currentScope != globalScope && identifier.getRefcount() == 0) {
warn("The symbol " + symbol + " is declared but is apparently never used.\nThis code can probably be written in a more compact way.", true);
}
token = consumeToken();
}
assert token.getType() == Token.LP;
result.append('(');
currentScope = (ScriptOrFnScope) indexedScopes.get(new Integer(offset));
enterScope(currentScope);
while ((token = consumeToken()).getType() != Token.RP) {
assert token.getType() == Token.NAME || token.getType() == Token.COMMA;
if (token.getType() == Token.NAME) {
symbol = token.getValue();
identifier = getIdentifier(symbol, currentScope);
assert identifier != null;
if (identifier.getMungedValue() != null) {
result.append(identifier.getMungedValue());
} else {
result.append(symbol);
}
} else if (token.getType() == Token.COMMA) {
result.append(',');
}
}
result.append(')');
token = consumeToken();
assert token.getType() == Token.LC;
result.append('{');
braceNesting++;
token = getToken(0);
if (token.getType() == Token.STRING &&
getToken(1).getType() == Token.SEMI) {
if (! preserveUnknownHints) {
// This is an unknown hint. Skip it!
consumeToken();
consumeToken();
}
}
break;
case Token.RETURN:
case Token.TYPEOF:
result.append(literals.get(new Integer(token.getType())));
// No space needed after 'return' and 'typeof' when followed
// by '(', '[', '{', a string or a regexp.
if (offset < length) {
token = getToken(0);
if (token.getType() != Token.LP &&
token.getType() != Token.LB &&
token.getType() != Token.LC &&
token.getType() != Token.STRING &&
token.getType() != Token.REGEXP &&
token.getType() != Token.SEMI) {
result.append(' ');
}
}
break;
case Token.CASE:
case Token.THROW:
result.append(literals.get(new Integer(token.getType())));
// White-space needed after 'case' and 'throw' when not followed by a string.
if (offset < length && getToken(0).getType() != Token.STRING) {
result.append(' ');
}
break;
case Token.BREAK:
case Token.CONTINUE:
result.append(literals.get(new Integer(token.getType())));
if (offset < length && getToken(0).getType() != Token.SEMI) {
// If 'break' or 'continue' is not followed by a semi-colon, it must
// be followed by a label, hence the need for a white space.
result.append(' ');
}
break;
case Token.LC:
result.append('{');
braceNesting++;
break;
case Token.RC:
result.append('}');
braceNesting--;
assert braceNesting >= currentScope.getBraceNesting();
if (braceNesting == currentScope.getBraceNesting()) {
leaveCurrentScope();
}
break;
case Token.SEMI:
// No need to output a semi-colon if the next character is a right-curly...
if (preserveAllSemiColons || offset < length && getToken(0).getType() != Token.RC) {
result.append(';');
}
if (linebreakpos >= 0 && result.length() - linestartpos > linebreakpos) {
// Some source control tools don't like it when files containing lines longer
// than, say 8000 characters, are checked in. The linebreak option is used in
// that case to split long lines after a specific column.
result.append('\n');
linestartpos = result.length();
}
break;
case Token.COMMA:
// No need to output a comma if the next character is a right-curly or a right-square bracket
if (offset < length && getToken(0).getType() != Token.RC && getToken(0).getType() != Token.RB) {
result.append(',');
}
break;
case Token.CONDCOMMENT:
case Token.KEEPCOMMENT:
if (result.length() > 0 && result.charAt(result.length() - 1) != '\n') {
result.append("\n");
}
result.append("/*");
if (token.getType() == Token.KEEPCOMMENT) {
result.append("!");
}
result.append(symbol);
result.append("*/\n");
break;
default:
String literal = (String) literals.get(new Integer(token.getType()));
if (literal != null) {
result.append(literal);
} else {
warn("This symbol cannot be printed: " + symbol, true);
}
break;
}
}
// Append a semi-colon at the end, even if unnecessary semi-colons are
// supposed to be removed. This is especially useful when concatenating
// several minified files (the absence of an ending semi-colon at the
// end of one file may very likely cause a syntax error)
if (!preserveAllSemiColons &&
result.length() > 0 &&
getToken(-1).getType() != Token.CONDCOMMENT &&
getToken(-1).getType() != Token.KEEPCOMMENT) {
if (result.charAt(result.length() - 1) == '\n') {
result.setCharAt(result.length() - 1, ';');
} else {
result.append(';');
}
}
return result;
}
private void printMungeMapping(Writer map) throws IOException {
StringBuffer sb = new StringBuffer();
globalScope.getFullMapping(sb, "");
map.write(sb.toString());
}
}