rename the npm package to "uglify-js" and cli tool to "uglifyjs"

otherwise we change the meaning of eval from global to lexical.

.gitignore

@@ -1 +1,2 @@
 tmp/
+node_modules/

README.md

@@ -14,7 +14,7 @@ Install
 
 From NPM:
 
-    npm install uglify-js2
+    npm install uglify-js
 
 From Git:
 
@@ -25,7 +25,7 @@ From Git:
 Usage
 -----
 
-    uglifyjs2 [input files] [options]
+    uglifyjs [input files] [options]
 
 UglifyJS2 can take multiple input files.  It's recommended that you pass the
 input files first, then pass the options.  UglifyJS will parse input files
@@ -98,7 +98,7 @@ map.
 
 For example:
 
-    uglifyjs2 /home/doe/work/foo/src/js/file1.js \
+    uglifyjs /home/doe/work/foo/src/js/file1.js \
              /home/doe/work/foo/src/js/file2.js \
              -o foo.min.js \
              --source-map foo.min.js.map \
@@ -140,7 +140,7 @@ When mangling is enabled but you want to prevent certain names from being
 mangled, you can declare those names with `--reserved` (`-r`) — pass a
 comma-separated list of names.  For example:
 
-    uglifyjs2 ... -m -r '$,require,exports'
+    uglifyjs ... -m -r '$,require,exports'
 
 to prevent the `require`, `exports` and `$` names from being changed.
 
@@ -206,7 +206,7 @@ separate file and include it into the build.  For example you can have a
 
 and build your code like this:
 
-    uglifyjs2 build/defines.js js/foo.js js/bar.js... -c
+    uglifyjs build/defines.js js/foo.js js/bar.js... -c
 
 UglifyJS will notice the constants and, since they cannot be altered, it
 will evaluate references to them to the value itself and drop unreachable
@@ -288,7 +288,7 @@ SpiderMonkey AST.  It has a small CLI utility that parses one file and dumps
 the AST in JSON on the standard output.  To use UglifyJS to mangle and
 compress that:
 
-    acorn file.js | uglifyjs2 --spidermonkey -m -c
+    acorn file.js | uglifyjs --spidermonkey -m -c
 
 The `--spidermonkey` option tells UglifyJS that all input files are not
 JavaScript, but JS code described in SpiderMonkey AST in JSON.  Therefore we
@@ -310,7 +310,7 @@ API Reference
 Assuming installation via NPM, you can load UglifyJS in your application
 like this:
 
-    var UglifyJS = require("uglify-js2");
+    var UglifyJS = require("uglify-js");
 
 It exports a lot of names, but I'll discuss here the basics that are needed
 for parsing, mangling and compressing a piece of code.  The sequence is (1)

bin/uglifyjs

@@ -252,7 +252,7 @@ if (SCOPE_IS_NEEDED) {
     time_it("scope", function(){
         TOPLEVEL.figure_out_scope();
         if (MANGLE) {
-            TOPLEVEL.compute_char_frequency();
+            TOPLEVEL.compute_char_frequency(MANGLE);
         }
     });
 }

lib/ast.js

@@ -345,6 +345,10 @@ var AST_Lambda = DEFNODE("Lambda", "name argnames uses_arguments", {
     }
 }, AST_Scope);
 
+var AST_Accessor = DEFNODE("Accessor", null, {
+    $documentation: "A setter/getter function"
+}, AST_Lambda);
+
 var AST_Function = DEFNODE("Function", null, {
     $documentation: "A function expression"
 }, AST_Lambda);
@@ -758,6 +762,10 @@ var AST_Symbol = DEFNODE("Symbol", "scope name thedef", {
     $documentation: "Base class for all symbols",
 });
 
+var AST_SymbolAccessor = DEFNODE("SymbolAccessor", null, {
+    $documentation: "The name of a property accessor (setter/getter function)"
+}, AST_Symbol);
+
 var AST_SymbolDeclaration = DEFNODE("SymbolDeclaration", "init", {
     $documentation: "A declaration symbol (symbol in var/const, function name or argument, symbol in catch)",
     $propdoc: {
@@ -802,7 +810,7 @@ var AST_SymbolRef = DEFNODE("SymbolRef", null, {
 
 var AST_LabelRef = DEFNODE("LabelRef", null, {
     $documentation: "Reference to a label symbol",
-}, AST_SymbolRef);
+}, AST_Symbol);
 
 var AST_This = DEFNODE("This", null, {
     $documentation: "The `this` symbol",

lib/compress.js

@@ -53,6 +53,7 @@ function Compressor(options, false_by_default) {
         dead_code     : !false_by_default,
         drop_debugger : !false_by_default,
         unsafe        : !false_by_default,
+        unsafe_comps  : false,
         conditionals  : !false_by_default,
         comparisons   : !false_by_default,
         evaluate      : !false_by_default,
@@ -553,12 +554,24 @@ merge(Compressor.prototype, {
         def(AST_UnaryPrefix, function(){
             return this.operator == "typeof";
         });
-        def(AST_Binary, function(){
+        def(AST_Binary, function(compressor){
             return this.operator == "+" &&
-                (this.left.is_string() || this.right.is_string());
+                (this.left.is_string(compressor) || this.right.is_string(compressor));
         });
-        def(AST_Assign, function(){
+        def(AST_Assign, function(compressor){
-            return this.operator == "=" && this.right.is_string();
+            return (this.operator == "=" || this.operator == "+=") && this.right.is_string(compressor);
+        });
+        def(AST_Seq, function(compressor){
+            return this.cdr.is_string(compressor);
+        });
+        def(AST_Conditional, function(compressor){
+            return this.consequent.is_string(compressor) && this.alternative.is_string(compressor);
+        });
+        def(AST_Call, function(compressor){
+            return compressor.option("unsafe")
+                && this.expression instanceof AST_SymbolRef
+                && this.expression.name == "String"
+                && this.expression.undeclared();
         });
     })(function(node, func){
         node.DEFMETHOD("is_string", func);
@@ -703,7 +716,7 @@ merge(Compressor.prototype, {
         });
         def(AST_Binary, function(compressor){
             var self = this.clone(), op = this.operator;
-            if (compressor.option("comparisons") && compressor.option("unsafe")) {
+            if (compressor.option("unsafe_comps")) {
                 switch (op) {
                   case "<=" : self.operator = ">"  ; return self;
                   case "<"  : self.operator = ">=" ; return self;
@@ -813,10 +826,12 @@ merge(Compressor.prototype, {
     (function(def){
         def(AST_Statement, function(){ return null });
         def(AST_Jump, function(){ return this });
-        def(AST_BlockStatement, function(){
+        function block_aborts(){
             var n = this.body.length;
             return n > 0 && aborts(this.body[n - 1]);
-        });
+        };
+        def(AST_BlockStatement, block_aborts);
+        def(AST_SwitchBranch, block_aborts);
         def(AST_If, function(){
             return this.alternative && aborts(this.body) && aborts(this.alternative);
         });
@@ -884,7 +899,7 @@ merge(Compressor.prototype, {
                         });
                         return true;
                     }
-                    if (node instanceof AST_SymbolRef && !(node instanceof AST_LabelRef)) {
+                    if (node instanceof AST_SymbolRef) {
                         push_uniq(in_use, node.definition());
                         return true;
                     }
@@ -907,8 +922,7 @@ merge(Compressor.prototype, {
                     if (decl instanceof AST_SymbolDeclaration) {
                         decl.init.forEach(function(init){
                             var tw = new TreeWalker(function(node){
-                                if (node instanceof AST_SymbolRef
+                                if (node instanceof AST_SymbolRef) {
-                                    && !(node instanceof AST_LabelRef)) {
                                     push_uniq(in_use, node.definition());
                                 }
                             });
@@ -919,7 +933,7 @@ merge(Compressor.prototype, {
             }
             // pass 3: we should drop declarations not in_use
             var tt = new TreeTransformer(
-                function before(node, descend) {
+                function before(node, descend, in_list) {
                     if (node instanceof AST_Lambda) {
                         for (var a = node.argnames, i = a.length; --i >= 0;) {
                             var sym = a[i];
@@ -1010,6 +1024,19 @@ merge(Compressor.prototype, {
                         }
                         return node;
                     }
+                    if (node instanceof AST_For && node.init instanceof AST_BlockStatement) {
+                        descend(node, this);
+                        // certain combination of unused name + side effect leads to:
+                        //    https://github.com/mishoo/UglifyJS2/issues/44
+                        // that's an invalid AST.
+                        // We fix it at this stage by moving the `var` outside the `for`.
+                        var body = node.init.body.slice(0, -1);
+                        node.init = node.init.body.slice(-1)[0].body;
+                        body.push(node);
+                        return in_list ? MAP.splice(body) : make_node(AST_BlockStatement, node, {
+                            body: body
+                        });
+                    }
                     if (node instanceof AST_Scope && node !== self)
                         return node;
                 }
@@ -1025,7 +1052,7 @@ merge(Compressor.prototype, {
         if (hoist_funs || hoist_vars) {
             var dirs = [];
             var hoisted = [];
-            var vars = {}, vars_found = 0, var_decl = 0;
+            var vars = new Dictionary(), vars_found = 0, var_decl = 0;
             // let's count var_decl first, we seem to waste a lot of
             // space if we hoist `var` when there's only one.
             self.walk(new TreeWalker(function(node){
@@ -1050,7 +1077,7 @@ merge(Compressor.prototype, {
                         }
                         if (node instanceof AST_Var && hoist_vars) {
                             node.definitions.forEach(function(def){
-                                vars[def.name.name] = def;
+                                vars.set(def.name.name, def);
                                 ++vars_found;
                             });
                             var seq = node.to_assignments();
@@ -1074,8 +1101,8 @@ merge(Compressor.prototype, {
             );
             self = self.transform(tt);
             if (vars_found > 0) hoisted.unshift(make_node(AST_Var, self, {
-                definitions: Object.keys(vars).map(function(name){
+                definitions: vars.map(function(def){
-                    var def = vars[name].clone();
+                    def = def.clone();
                     def.value = null;
                     return def;
                 })
@@ -1117,6 +1144,61 @@ merge(Compressor.prototype, {
         return self;
     });
 
+    function if_break_in_loop(self, compressor) {
+        function drop_it(rest) {
+            rest = as_statement_array(rest);
+            if (self.body instanceof AST_BlockStatement) {
+                self.body = self.body.clone();
+                self.body.body = rest.concat(self.body.body.slice(1));
+                self.body = self.body.transform(compressor);
+            } else {
+                self.body = make_node(AST_BlockStatement, self.body, {
+                    body: rest
+                }).transform(compressor);
+            }
+            if_break_in_loop(self, compressor);
+        }
+        var first = self.body instanceof AST_BlockStatement ? self.body.body[0] : self.body;
+        if (first instanceof AST_If) {
+            if (first.body instanceof AST_Break
+                && compressor.loopcontrol_target(first.body.label) === self) {
+                if (self.condition) {
+                    self.condition = make_node(AST_Binary, self.condition, {
+                        left: self.condition,
+                        operator: "&&",
+                        right: first.condition.negate(compressor),
+                    });
+                } else {
+                    self.condition = first.condition.negate(compressor);
+                }
+                drop_it(first.alternative);
+            }
+            else if (first.alternative instanceof AST_Break
+                     && compressor.loopcontrol_target(first.alternative.label) === self) {
+                if (self.condition) {
+                    self.condition = make_node(AST_Binary, self.condition, {
+                        left: self.condition,
+                        operator: "&&",
+                        right: first.condition,
+                    });
+                } else {
+                    self.condition = first.condition;
+                }
+                drop_it(first.body);
+            }
+        }
+    };
+
+    OPT(AST_While, function(self, compressor) {
+        if (!compressor.option("loops")) return self;
+        self = AST_DWLoop.prototype.optimize.call(self, compressor);
+        if (self instanceof AST_While) {
+            if_break_in_loop(self, compressor);
+            self = make_node(AST_For, self, self).transform(compressor);
+        }
+        return self;
+    });
+
     OPT(AST_For, function(self, compressor){
         var cond = self.condition;
         if (cond) {
@@ -1141,6 +1223,7 @@ merge(Compressor.prototype, {
                 }
             }
         }
+        if_break_in_loop(self, compressor);
         return self;
     });
 
@@ -1279,6 +1362,79 @@ merge(Compressor.prototype, {
             if (stat instanceof AST_Break && loop_body(compressor.loopcontrol_target(stat.label)) === self)
                 last_branch.body.pop();
         }
+        var exp = self.expression.evaluate(compressor);
+        out: if (exp.length == 2) try {
+            // constant expression
+            self.expression = exp[0];
+            if (!compressor.option("dead_code")) break out;
+            var value = exp[1];
+            var in_if = false;
+            var in_block = false;
+            var started = false;
+            var stopped = false;
+            var ruined = false;
+            var tt = new TreeTransformer(function(node, descend, in_list){
+                if (node instanceof AST_Lambda || node instanceof AST_SimpleStatement) {
+                    // no need to descend these node types
+                    return node;
+                }
+                else if (node instanceof AST_Switch && node === self) {
+                    node = node.clone();
+                    descend(node, this);
+                    return ruined ? node : make_node(AST_BlockStatement, node, {
+                        body: node.body.reduce(function(a, branch){
+                            return a.concat(branch.body);
+                        }, [])
+                    }).transform(compressor);
+                }
+                else if (node instanceof AST_If || node instanceof AST_Try) {
+                    var save = in_if;
+                    in_if = !in_block;
+                    descend(node, this);
+                    in_if = save;
+                    return node;
+                }
+                else if (node instanceof AST_StatementWithBody || node instanceof AST_Switch) {
+                    var save = in_block;
+                    in_block = true;
+                    descend(node, this);
+                    in_block = save;
+                    return node;
+                }
+                else if (node instanceof AST_Break && this.loopcontrol_target(node.label) === self) {
+                    if (in_if) {
+                        ruined = true;
+                        return node;
+                    }
+                    if (in_block) return node;
+                    stopped = true;
+                    return in_list ? MAP.skip : make_node(AST_EmptyStatement, node);
+                }
+                else if (node instanceof AST_SwitchBranch && this.parent() === self) {
+                    if (stopped) return MAP.skip;
+                    if (node instanceof AST_Case) {
+                        var exp = node.expression.evaluate(compressor);
+                        if (exp.length < 2) {
+                            // got a case with non-constant expression, baling out
+                            throw self;
+                        }
+                        if (exp[1] === value || started) {
+                            started = true;
+                            if (aborts(node)) stopped = true;
+                            descend(node, this);
+                            return node;
+                        }
+                        return MAP.skip;
+                    }
+                    descend(node, this);
+                    return node;
+                }
+            });
+            tt.stack = compressor.stack; // so that's able to see parent nodes
+            self = self.transform(tt);
+        } catch(ex) {
+            if (ex !== self) throw ex;
+        }
         return self;
     });
 
@@ -1357,9 +1513,9 @@ merge(Compressor.prototype, {
             }
             else if (exp instanceof AST_Dot && exp.property == "toString" && self.args.length == 0) {
                 return make_node(AST_Binary, self, {
-                    left: exp.expression,
+                    left: make_node(AST_String, self, { value: "" }),
                     operator: "+",
-                    right: make_node(AST_String, self, { value: "" })
+                    right: exp.expression
                 }).transform(compressor);
             }
         }
@@ -1393,8 +1549,19 @@ merge(Compressor.prototype, {
     OPT(AST_Seq, function(self, compressor){
         if (!compressor.option("side_effects"))
             return self;
-        if (!self.car.has_side_effects())
+        if (!self.car.has_side_effects()) {
+            // we shouldn't compress (1,eval)(something) to
+            // eval(something) because that changes the meaning of
+            // eval (becomes lexical instead of global).
+            var p;
+            if (!(self.cdr instanceof AST_SymbolRef
+                  && self.cdr.name == "eval"
+                  && self.cdr.undeclared()
+                  && (p = compressor.parent()) instanceof AST_Call
+                  && p.expression === self)) {
                 return self.cdr;
+            }
+        }
         if (compressor.option("cascade")) {
             if (self.car instanceof AST_Assign
                 && !self.car.left.has_side_effects()
@@ -1445,10 +1612,10 @@ merge(Compressor.prototype, {
                 compressor.warn("Boolean expression always true [{file}:{line},{col}]", self.start);
                 return make_node(AST_True, self);
             }
-        }
+            if (e instanceof AST_Binary && self.operator == "!") {
-        if (e instanceof AST_Binary) {
                 self = best_of(self, e.negate(compressor));
             }
+        }
         return self.evaluate(compressor)[0];
     });
 
@@ -1476,30 +1643,35 @@ merge(Compressor.prototype, {
         return this;
     });
 
+    var commutativeOperators = makePredicate("== === != !== * & | ^");
+
     OPT(AST_Binary, function(self, compressor){
+        function reverse(op) {
+            if (!(self.left.has_side_effects() && self.right.has_side_effects())) {
+                if (op) self.operator = op;
+                var tmp = self.left;
+                self.left = self.right;
+                self.right = tmp;
+            }
+        };
+        if (commutativeOperators(self.operator)) {
+            if (self.right instanceof AST_Constant
+                && !(self.left instanceof AST_Constant)) {
+                reverse();
+            }
+        }
         self = self.lift_sequences(compressor);
         if (compressor.option("comparisons")) switch (self.operator) {
           case "===":
           case "!==":
-            if ((self.left.is_string() && self.right.is_string()) ||
+            if ((self.left.is_string(compressor) && self.right.is_string(compressor)) ||
                 (self.left.is_boolean() && self.right.is_boolean())) {
                 self.operator = self.operator.substr(0, 2);
             }
             // XXX: intentionally falling down to the next case
           case "==":
           case "!=":
-            if (self.left instanceof AST_UnaryPrefix
+            if (self.left instanceof AST_String
-                && self.left.operator == "typeof"
-                && self.right instanceof AST_String
-                && self.right.value == "undefined") {
-                if (!(self.left.expression instanceof AST_SymbolRef)
-                    || !self.left.expression.undeclared()) {
-                    self.left = self.left.expression;
-                    self.right = make_node(AST_Undefined, self.right).optimize(compressor);
-                    if (self.operator.length == 2) self.operator += "=";
-                }
-            }
-            else if (self.left instanceof AST_String
                 && self.left.value == "undefined"
                 && self.right instanceof AST_UnaryPrefix
                 && self.right.operator == "typeof") {
@@ -1565,17 +1737,16 @@ merge(Compressor.prototype, {
                 });
                 self = best_of(self, negated);
             }
-            var reverse = function(op) {
-                self.operator = op;
-                var tmp = self.left;
-                self.left = self.right;
-                self.right = tmp;
-            };
             switch (self.operator) {
               case "<": reverse(">"); break;
               case "<=": reverse(">="); break;
             }
         }
+        if (self.operator == "+" && self.right instanceof AST_String
+            && self.right.getValue() === "" && self.left instanceof AST_Binary
+            && self.left.operator == "+" && self.left.is_string()) {
+            return self.left;
+        }
         return self;
     });
 

lib/output.js

@@ -59,7 +59,8 @@ function OutputStream(options) {
         source_map    : null,
         bracketize    : false,
         semicolons    : true,
-        comments      : false
+        comments      : false,
+        preserve_line : false
     }, true);
 
     var indentation = 0;
@@ -137,7 +138,7 @@ function OutputStream(options) {
         str = String(str);
         var ch = str.charAt(0);
         if (might_need_semicolon) {
-            if (";}".indexOf(ch) < 0 && !/[;]$/.test(last)) {
+            if ((!ch || ";}".indexOf(ch) < 0) && !/[;]$/.test(last)) {
                 if (options.semicolons || requireSemicolonChars(ch)) {
                     OUTPUT += ";";
                     current_col++;
@@ -154,6 +155,18 @@ function OutputStream(options) {
             might_need_semicolon = false;
             maybe_newline();
         }
+
+        if (!options.beautify && options.preserve_line && stack[stack.length - 1]) {
+            var target_line = stack[stack.length - 1].start.line;
+            while (current_line < target_line) {
+                OUTPUT += "\n";
+                current_pos++;
+                current_line++;
+                current_col = 0;
+                might_need_space = false;
+            }
+        }
+
         if (might_need_space) {
             var prev = last_char();
             if ((is_identifier_char(prev)
@@ -410,6 +423,11 @@ function OutputStream(options) {
         return first_in_statement(output);
     });
 
+    PARENS(AST_Unary, function(output){
+        var p = output.parent();
+        return p instanceof AST_PropAccess && p.expression === this;
+    });
+
     PARENS(AST_Seq, function(output){
         var p = output.parent();
         return p instanceof AST_Call             // (foo, bar)() or foo(1, (2, 3), 4)
@@ -463,10 +481,36 @@ function OutputStream(options) {
         }
     });
 
+    PARENS(AST_PropAccess, function(output){
+        var p = output.parent();
+        if (p instanceof AST_New && p.expression === this) {
+            // i.e. new (foo.bar().baz)
+            //
+            // if there's one call into this subtree, then we need
+            // parens around it too, otherwise the call will be
+            // interpreted as passing the arguments to the upper New
+            // expression.
+            try {
+                this.walk(new TreeWalker(function(node){
+                    if (node instanceof AST_Call) throw p;
+                }));
+            } catch(ex) {
+                if (ex !== p) throw ex;
+                return true;
+            }
+        }
+    });
+
+    PARENS(AST_Call, function(output){
+        var p = output.parent();
+        return p instanceof AST_New && p.expression === this;
+    });
+
     PARENS(AST_New, function(output){
         var p = output.parent();
-        // (new Date).getTime();
+        if (no_constructor_parens(this, output)
-        if (p instanceof AST_Dot && no_constructor_parens(this, output))
+            && (p instanceof AST_Dot // (new Date).getTime()
+                || p instanceof AST_Call && p.expression === this)) // (new foo)(bar)
             return true;
     });
 
@@ -529,6 +573,7 @@ function OutputStream(options) {
     });
     DEFPRINT(AST_Toplevel, function(self, output){
         display_body(self.body, true, output);
+        output.print("");
     });
     DEFPRINT(AST_LabeledStatement, function(self, output){
         self.label.print(output);

lib/parse.js

@@ -883,6 +883,8 @@ function parse($TEXT, options) {
     var function_ = function(in_statement, ctor) {
         var name = is("name") ? as_symbol(in_statement
                                           ? AST_SymbolDefun
+                                          : ctor === AST_Accessor
+                                          ? AST_SymbolAccessor
                                           : AST_SymbolLambda) : null;
         if (in_statement && !name)
             unexpected();
@@ -1158,7 +1160,7 @@ function parse($TEXT, options) {
                     a.push(new AST_ObjectGetter({
                         start : start,
                         key   : name,
-                        value : function_(false, AST_Lambda),
+                        value : function_(false, AST_Accessor),
                         end   : prev()
                     }));
                     continue;
@@ -1167,7 +1169,7 @@ function parse($TEXT, options) {
                     a.push(new AST_ObjectSetter({
                         start : start,
                         key   : name,
-                        value : function_(false, AST_Lambda),
+                        value : function_(false, AST_Accessor),
                         end   : prev()
                     }));
                     continue;

lib/scope.js

@@ -43,7 +43,7 @@
 
 "use strict";
 
-function SymbolDef(scope, orig) {
+function SymbolDef(scope, index, orig) {
     this.name = orig.name;
     this.orig = [ orig ];
     this.scope = scope;
@@ -52,15 +52,18 @@ function SymbolDef(scope, orig) {
     this.mangled_name = null;
     this.undeclared = false;
     this.constant = false;
+    this.index = index;
 };
 
 SymbolDef.prototype = {
-    unmangleable: function() {
+    unmangleable: function(options) {
-        return this.global || this.undeclared || this.scope.uses_eval || this.scope.uses_with;
+        return this.global
+            || this.undeclared
+            || (!(options && options.eval) && (this.scope.uses_eval || this.scope.uses_with));
     },
-    mangle: function() {
+    mangle: function(options) {
-        if (!this.mangled_name && !this.unmangleable())
+        if (!this.mangled_name && !this.unmangleable(options))
-            this.mangled_name = this.scope.next_mangled();
+            this.mangled_name = this.scope.next_mangled(options);
     }
 };
 
@@ -75,14 +78,17 @@ AST_Toplevel.DEFMETHOD("figure_out_scope", function(){
     // pass 1: setup scope chaining and handle definitions
     var self = this;
     var scope = self.parent_scope = null;
-    var labels = Object.create(null);
+    var labels = new Dictionary();
+    var nesting = 0;
     var tw = new TreeWalker(function(node, descend){
         if (node instanceof AST_Scope) {
-            node.init_scope_vars();
+            node.init_scope_vars(nesting);
             var save_scope = node.parent_scope = scope;
+            ++nesting;
             scope = node;
             descend();
             scope = save_scope;
+            --nesting;
             return true;        // don't descend again in TreeWalker
         }
         if (node instanceof AST_Directive) {
@@ -97,11 +103,11 @@ AST_Toplevel.DEFMETHOD("figure_out_scope", function(){
         }
         if (node instanceof AST_LabeledStatement) {
             var l = node.label;
-            if (labels[l.name])
+            if (labels.has(l.name))
                 throw new Error(string_template("Label {name} defined twice", l));
-            labels[l.name] = l;
+            labels.set(l.name, l);
             descend();
-            delete labels[l.name];
+            labels.del(l.name);
             return true;        // no descend again
         }
         if (node instanceof AST_SymbolDeclaration) {
@@ -151,7 +157,7 @@ AST_Toplevel.DEFMETHOD("figure_out_scope", function(){
             scope.def_variable(node);
         }
         if (node instanceof AST_LabelRef) {
-            var sym = labels[node.name];
+            var sym = labels.get(node.name);
             if (!sym) throw new Error(string_template("Undefined label {name} [{line},{col}]", {
                 name: node.name,
                 line: node.start.line,
@@ -164,7 +170,7 @@ AST_Toplevel.DEFMETHOD("figure_out_scope", function(){
 
     // pass 2: find back references and eval
     var func = null;
-    var globals = self.globals = Object.create(null);
+    var globals = self.globals = new Dictionary();
     var tw = new TreeWalker(function(node, descend){
         if (node instanceof AST_Lambda) {
             var prev_func = func;
@@ -182,12 +188,12 @@ AST_Toplevel.DEFMETHOD("figure_out_scope", function(){
             var sym = node.scope.find_variable(name);
             if (!sym) {
                 var g;
-                if (globals[name]) {
+                if (globals.has(name)) {
-                    g = globals[name];
+                    g = globals.get(name);
                 } else {
-                    g = new SymbolDef(self, node);
+                    g = new SymbolDef(self, globals.size(), node);
                     g.undeclared = true;
-                    globals[name] = g;
+                    globals.set(name, g);
                 }
                 node.thedef = g;
                 if (name == "eval" && tw.parent() instanceof AST_Call) {
@@ -207,15 +213,16 @@ AST_Toplevel.DEFMETHOD("figure_out_scope", function(){
     self.walk(tw);
 });
 
-AST_Scope.DEFMETHOD("init_scope_vars", function(){
+AST_Scope.DEFMETHOD("init_scope_vars", function(nesting){
     this.directives = [];     // contains the directives defined in this scope, i.e. "use strict"
-    this.variables = Object.create(null); // map name to AST_SymbolVar (variables defined in this scope; includes functions)
+    this.variables = new Dictionary(); // map name to AST_SymbolVar (variables defined in this scope; includes functions)
-    this.functions = Object.create(null); // map name to AST_SymbolDefun (functions defined in this scope)
+    this.functions = new Dictionary(); // map name to AST_SymbolDefun (functions defined in this scope)
     this.uses_with = false;   // will be set to true if this or some nested scope uses the `with` statement
     this.uses_eval = false;   // will be set to true if this or nested scope uses the global `eval`
     this.parent_scope = null; // the parent scope
     this.enclosed = [];       // a list of variables from this or outer scope(s) that are referenced from this or inner scopes
     this.cname = -1;          // the current index for mangling functions/variables
+    this.nesting = nesting;   // the nesting level of this scope (0 means toplevel)
 });
 
 AST_Scope.DEFMETHOD("strict", function(){
@@ -223,7 +230,7 @@ AST_Scope.DEFMETHOD("strict", function(){
 });
 
 AST_Lambda.DEFMETHOD("init_scope_vars", function(){
-    AST_Scope.prototype.init_scope_vars.call(this);
+    AST_Scope.prototype.init_scope_vars.apply(this, arguments);
     this.uses_arguments = false;
 });
 
@@ -236,6 +243,7 @@ AST_SymbolRef.DEFMETHOD("reference", function() {
         if (s === def.scope) break;
         s = s.parent_scope;
     }
+    this.frame = this.scope.nesting - def.scope.nesting;
 });
 
 AST_SymbolDeclaration.DEFMETHOD("init_scope_vars", function(){
@@ -252,7 +260,7 @@ AST_LabelRef.DEFMETHOD("reference", function(){
 
 AST_Scope.DEFMETHOD("find_variable", function(name){
     if (name instanceof AST_Symbol) name = name.name;
-    return this.variables[name]
+    return this.variables.get(name)
         || (this.parent_scope && this.parent_scope.find_variable(name));
 });
 
@@ -262,23 +270,23 @@ AST_Scope.DEFMETHOD("has_directive", function(value){
 });
 
 AST_Scope.DEFMETHOD("def_function", function(symbol){
-    this.functions[symbol.name] = this.def_variable(symbol);
+    this.functions.set(symbol.name, this.def_variable(symbol));
 });
 
 AST_Scope.DEFMETHOD("def_variable", function(symbol){
     var def;
-    if (!this.variables[symbol.name]) {
+    if (!this.variables.has(symbol.name)) {
-        def = new SymbolDef(this, symbol);
+        def = new SymbolDef(this, this.variables.size(), symbol);
-        this.variables[symbol.name] = def;
+        this.variables.set(symbol.name, def);
         def.global = !this.parent_scope;
     } else {
-        def = this.variables[symbol.name];
+        def = this.variables.get(symbol.name);
         def.orig.push(symbol);
     }
     return symbol.thedef = def;
 });
 
-AST_Scope.DEFMETHOD("next_mangled", function(){
+AST_Scope.DEFMETHOD("next_mangled", function(options){
     var ext = this.enclosed, n = ext.length;
     out: while (true) {
         var m = base54(++this.cname);
@@ -288,7 +296,7 @@ AST_Scope.DEFMETHOD("next_mangled", function(){
         // inner scopes.
         for (var i = n; --i >= 0;) {
             var sym = ext[i];
-            var name = sym.mangled_name || (sym.unmangleable() && sym.name);
+            var name = sym.mangled_name || (sym.unmangleable(options) && sym.name);
             if (m == name) continue out;
         }
         return m;
@@ -300,8 +308,13 @@ AST_Scope.DEFMETHOD("references", function(sym){
     return this.enclosed.indexOf(sym) < 0 ? null : sym;
 });
 
-AST_Symbol.DEFMETHOD("unmangleable", function(){
+AST_Symbol.DEFMETHOD("unmangleable", function(options){
-    return this.definition().unmangleable();
+    return this.definition().unmangleable(options);
+});
+
+// property accessors are not mangleable
+AST_SymbolAccessor.DEFMETHOD("unmangleable", function(){
+    return true;
 });
 
 // labels are always mangleable
@@ -334,10 +347,15 @@ AST_Symbol.DEFMETHOD("global", function(){
     return this.definition().global;
 });
 
-AST_Toplevel.DEFMETHOD("mangle_names", function(options){
+AST_Toplevel.DEFMETHOD("_default_mangler_options", function(options){
-    options = defaults(options, {
+    return defaults(options, {
-        except : []
+        except : [],
+        eval   : false,
     });
+});
+
+AST_Toplevel.DEFMETHOD("mangle_names", function(options){
+    options = this._default_mangler_options(options);
     // We only need to mangle declaration nodes.  Special logic wired
     // into the code generator will display the mangled name if it's
     // present (and for AST_SymbolRef-s it'll use the mangled name of
@@ -354,16 +372,11 @@ AST_Toplevel.DEFMETHOD("mangle_names", function(options){
         }
         if (node instanceof AST_Scope) {
             var p = tw.parent();
-            var is_setget = p instanceof AST_ObjectSetter || p instanceof AST_ObjectGetter;
+            node.variables.each(function(symbol){
-            var a = node.variables;
-            for (var i in a) {
-                var symbol = a[i];
-                if (!(is_setget && symbol instanceof AST_SymbolLambda)) {
                 if (options.except.indexOf(symbol.name) < 0) {
                     to_mangle.push(symbol);
                 }
-                }
+            });
-            }
             return;
         }
         if (node instanceof AST_Label) {
@@ -377,7 +390,8 @@ AST_Toplevel.DEFMETHOD("mangle_names", function(options){
     to_mangle.forEach(function(def){ def.mangle(options) });
 });
 
-AST_Toplevel.DEFMETHOD("compute_char_frequency", function(){
+AST_Toplevel.DEFMETHOD("compute_char_frequency", function(options){
+    options = this._default_mangler_options(options);
     var tw = new TreeWalker(function(node){
         if (node instanceof AST_Constant)
             base54.consider(node.print_to_string());
@@ -435,7 +449,7 @@ AST_Toplevel.DEFMETHOD("compute_char_frequency", function(){
             base54.consider("catch");
         else if (node instanceof AST_Finally)
             base54.consider("finally");
-        else if (node instanceof AST_Symbol && node.unmangleable())
+        else if (node instanceof AST_Symbol && node.unmangleable(options))
             base54.consider(node.name);
         else if (node instanceof AST_Unary || node instanceof AST_Binary)
             base54.consider(node.operator);

lib/transform.js

@@ -65,7 +65,7 @@ TreeTransformer.prototype = new TreeWalker;
                     x = this;
                     descend(x, tw);
                 } else {
-                    tw.stack[tw.stack - 1] = x = this.clone();
+                    tw.stack[tw.stack.length - 1] = x = this.clone();
                     descend(x, tw);
                     y = tw.after(x, in_list);
                     if (y !== undefined) x = y;

lib/utils.js

@@ -244,3 +244,37 @@ function makePredicate(words) {
     }
     return new Function("str", f);
 };
+
+function Dictionary() {
+    this._values = Object.create(null);
+    this._size = 0;
+};
+Dictionary.prototype = {
+    set: function(key, val) {
+        if (!this.has(key)) ++this._size;
+        this._values["$" + key] = val;
+        return this;
+    },
+    get: function(key) { return this._values["$" + key] },
+    del: function(key) {
+        if (this.has(key)) {
+            --this._size;
+            delete this._values["$" + key];
+        }
+        return this;
+    },
+    has: function(key) { return ("$" + key) in this._values },
+    each: function(f) {
+        for (var i in this._values)
+            f(this._values[i], i.substr(1));
+    },
+    size: function() {
+        return this._size;
+    },
+    map: function(f) {
+        var ret = [];
+        for (var i in this._values)
+            ret.push(f(this._values[i], i.substr(1)));
+        return ret;
+    }
+};

package.json

@@ -1,9 +1,9 @@
 {
-    "name": "uglify-js2",
+    "name": "uglify-js",
     "description": "JavaScript parser, mangler/compressor and beautifier toolkit",
     "homepage": "http://lisperator.net/uglifyjs",
     "main": "tools/node.js",
-    "version": "2.1.5",
+    "version": "2.2.0",
     "engines": { "node" : ">=0.4.0" },
     "maintainers": [{
         "name": "Mihai Bazon",
@@ -15,11 +15,11 @@
         "url": "https://github.com/mishoo/UglifyJS2.git"
     }],
     "dependencies": {
-        "source-map" : "*",
+        "source-map" : "~0.1.7",
-        "optimist"   : "*"
+        "optimist"   : "~0.3.5"
     },
     "bin": {
-        "uglifyjs2" : "bin/uglifyjs2"
+        "uglifyjs" : "bin/uglifyjs"
     },
     "scripts": {"test": "node test/run-tests.js"}
 }

test/compress/issue-44.js

@@ -0,0 +1,31 @@
+issue_44_valid_ast_1: {
+    options = { unused: true };
+    input: {
+        function a(b) {
+            for (var i = 0, e = b.qoo(); ; i++) {}
+        }
+    }
+    expect: {
+        function a(b) {
+            var i = 0;
+            for (b.qoo(); ; i++);
+        }
+    }
+}
+
+issue_44_valid_ast_2: {
+    options = { unused: true };
+    input: {
+        function a(b) {
+            if (foo) for (var i = 0, e = b.qoo(); ; i++) {}
+        }
+    }
+    expect: {
+        function a(b) {
+            if (foo) {
+                var i = 0;
+                for (b.qoo(); ; i++);
+            }
+        }
+    }
+}

test/compress/loops.js

@@ -0,0 +1,123 @@
+while_becomes_for: {
+    options = { loops: true };
+    input: {
+        while (foo()) bar();
+    }
+    expect: {
+        for (; foo(); ) bar();
+    }
+}
+
+drop_if_break_1: {
+    options = { loops: true };
+    input: {
+        for (;;)
+            if (foo()) break;
+    }
+    expect: {
+        for (; !foo(););
+    }
+}
+
+drop_if_break_2: {
+    options = { loops: true };
+    input: {
+        for (;bar();)
+            if (foo()) break;
+    }
+    expect: {
+        for (; bar() && !foo(););
+    }
+}
+
+drop_if_break_3: {
+    options = { loops: true };
+    input: {
+        for (;bar();) {
+            if (foo()) break;
+            stuff1();
+            stuff2();
+        }
+    }
+    expect: {
+        for (; bar() && !foo();) {
+            stuff1();
+            stuff2();
+        }
+    }
+}
+
+drop_if_break_4: {
+    options = { loops: true, sequences: true };
+    input: {
+        for (;bar();) {
+            x();
+            y();
+            if (foo()) break;
+            z();
+            k();
+        }
+    }
+    expect: {
+        for (; bar() && (x(), y(), !foo());) z(), k();
+    }
+}
+
+drop_if_else_break_1: {
+    options = { loops: true };
+    input: {
+        for (;;) if (foo()) bar(); else break;
+    }
+    expect: {
+        for (; foo(); ) bar();
+    }
+}
+
+drop_if_else_break_2: {
+    options = { loops: true };
+    input: {
+        for (;bar();) {
+            if (foo()) baz();
+            else break;
+        }
+    }
+    expect: {
+        for (; bar() && foo();) baz();
+    }
+}
+
+drop_if_else_break_3: {
+    options = { loops: true };
+    input: {
+        for (;bar();) {
+            if (foo()) baz();
+            else break;
+            stuff1();
+            stuff2();
+        }
+    }
+    expect: {
+        for (; bar() && foo();) {
+            baz();
+            stuff1();
+            stuff2();
+        }
+    }
+}
+
+drop_if_else_break_4: {
+    options = { loops: true, sequences: true };
+    input: {
+        for (;bar();) {
+            x();
+            y();
+            if (foo()) baz();
+            else break;
+            z();
+            k();
+        }
+    }
+    expect: {
+        for (; bar() && (x(), y(), foo());) baz(), z(), k();
+    }
+}

test/compress/switch.js

@@ -0,0 +1,210 @@
+constant_switch_1: {
+    options = { dead_code: true, evaluate: true };
+    input: {
+        switch (1+1) {
+          case 1: foo(); break;
+          case 1+1: bar(); break;
+          case 1+1+1: baz(); break;
+        }
+    }
+    expect: {
+        bar();
+    }
+}
+
+constant_switch_2: {
+    options = { dead_code: true, evaluate: true };
+    input: {
+        switch (1) {
+          case 1: foo();
+          case 1+1: bar(); break;
+          case 1+1+1: baz();
+        }
+    }
+    expect: {
+        foo();
+        bar();
+    }
+}
+
+constant_switch_3: {
+    options = { dead_code: true, evaluate: true };
+    input: {
+        switch (10) {
+          case 1: foo();
+          case 1+1: bar(); break;
+          case 1+1+1: baz();
+          default:
+            def();
+        }
+    }
+    expect: {
+        def();
+    }
+}
+
+constant_switch_4: {
+    options = { dead_code: true, evaluate: true };
+    input: {
+        switch (2) {
+          case 1:
+            x();
+            if (foo) break;
+            y();
+            break;
+          case 1+1:
+            bar();
+          default:
+            def();
+        }
+    }
+    expect: {
+        bar();
+        def();
+    }
+}
+
+constant_switch_5: {
+    options = { dead_code: true, evaluate: true };
+    input: {
+        switch (1) {
+          case 1:
+            x();
+            if (foo) break;
+            y();
+            break;
+          case 1+1:
+            bar();
+          default:
+            def();
+        }
+    }
+    expect: {
+        // the break inside the if ruins our job
+        // we can still get rid of irrelevant cases.
+        switch (1) {
+          case 1:
+            x();
+            if (foo) break;
+            y();
+        }
+        // XXX: we could optimize this better by inventing an outer
+        // labeled block, but that's kinda tricky.
+    }
+}
+
+constant_switch_6: {
+    options = { dead_code: true, evaluate: true };
+    input: {
+        OUT: {
+            foo();
+            switch (1) {
+              case 1:
+                x();
+                if (foo) break OUT;
+                y();
+              case 1+1:
+                bar();
+                break;
+              default:
+                def();
+            }
+        }
+    }
+    expect: {
+        OUT: {
+            foo();
+            x();
+            if (foo) break OUT;
+            y();
+            bar();
+        }
+    }
+}
+
+constant_switch_7: {
+    options = { dead_code: true, evaluate: true };
+    input: {
+        OUT: {
+            foo();
+            switch (1) {
+              case 1:
+                x();
+                if (foo) break OUT;
+                for (var x = 0; x < 10; x++) {
+                    if (x > 5) break; // this break refers to the for, not to the switch; thus it
+                                      // shouldn't ruin our optimization
+                    console.log(x);
+                }
+                y();
+              case 1+1:
+                bar();
+                break;
+              default:
+                def();
+            }
+        }
+    }
+    expect: {
+        OUT: {
+            foo();
+            x();
+            if (foo) break OUT;
+            for (var x = 0; x < 10; x++) {
+                if (x > 5) break;
+                console.log(x);
+            }
+            y();
+            bar();
+        }
+    }
+}
+
+constant_switch_8: {
+    options = { dead_code: true, evaluate: true };
+    input: {
+        OUT: switch (1) {
+          case 1:
+            x();
+            for (;;) break OUT;
+            y();
+            break;
+          case 1+1:
+            bar();
+          default:
+            def();
+        }
+    }
+    expect: {
+        OUT: {
+            x();
+            for (;;) break OUT;
+            y();
+        }
+    }
+}
+
+constant_switch_9: {
+    options = { dead_code: true, evaluate: true };
+    input: {
+        OUT: switch (1) {
+          case 1:
+            x();
+            for (;;) if (foo) break OUT;
+            y();
+          case 1+1:
+            bar();
+          default:
+            def();
+        }
+    }
+    expect: {
+        OUT: {
+            x();
+            for (;;) if (foo) break OUT;
+            y();
+            bar();
+            def();
+        }
+    }
+}

tools/node.js

@@ -1,18 +1,5 @@
 var path = require("path");
 var fs = require("fs");
-
-// Avoid NodeJS warning.
-//
-// There's a --no-deprecation command line argument supported by
-// NodeJS, but that's tricky to use, so I'd like to set it from the
-// program itself.  Turns out you need to set `process.noDeprecation`,
-// but by the time you can set that the `path` module is already
-// loaded and `path.existsSync` is already changed to display that
-// warning, therefore here's the poor solution:
-if (fs.existsSync) {
-    path.existsSync = fs.existsSync;
-}
-
 var vm = require("vm");
 var sys = require("util");