v2.8.26

Account for comments when detecting property access in `tokenizer`.

fixes #1943

README.md

@@ -11,9 +11,10 @@ There's also an
 Chrome and probably Safari).
 
 #### Note:
-- release versions of `uglify-js` only support ECMAScript 5 (ES5). If you wish to minify
-ES2015+ (ES6+) code then please use the [harmony](#harmony) development branch.
-- Node 7 has a known performance regression and runs `uglify-js` twice as slow.
+- `uglify-js` only supports ECMAScript 5 (ES5).
+- Support for `const` is [present but incomplete](#support-for-const), and may not be
+  transformed properly.
+- Those wishing to minify ES2015+ (ES6+) should use the `npm` package [**uglify-es**](https://github.com/mishoo/UglifyJS2/tree/harmony).
 
 Install
 -------
@@ -29,12 +30,6 @@ From NPM for programmatic use:
 
     npm install uglify-js
 
-From Git:
-
-    git clone git://github.com/mishoo/UglifyJS2.git
-    cd UglifyJS2
-    npm link .
-
 Usage
 -----
 
@@ -441,13 +436,19 @@ to set `true`; it's effectively a shortcut for `foo=true`).
   compressor from discarding function names.  Useful for code relying on
   `Function.prototype.name`. See also: the `keep_fnames` [mangle option](#mangle).
 
-- `passes` -- default `1`. Number of times to run compress. Use an
-  integer argument larger than 1 to further reduce code size in some cases.
-  Note: raising the number of passes will increase uglify compress time.
+- `passes` -- default `1`. Number of times to run compress with a maximum of 3.
+  In some cases more than one pass leads to further compressed code.  Keep in
+  mind more passes will take more time.
 
 - `keep_infinity` -- default `false`. Pass `true` to prevent `Infinity` from
   being compressed into `1/0`, which may cause performance issues on Chrome.
 
+- `side_effects` -- default `false`. Pass `true` to potentially drop functions
+marked as "pure".  A function call is marked as "pure" if a comment annotation
+`/*@__PURE__*/` or `/*#__PURE__*/` immediately precedes the call. For example:
+`/*@__PURE__*/foo()`;
+
+
 ### The `unsafe` option
 
 It enables some transformations that *might* break code logic in certain
@@ -983,19 +984,9 @@ The `source_map_options` (optional) can contain the following properties:
   [compressor]: http://lisperator.net/uglifyjs/compress
   [parser]: http://lisperator.net/uglifyjs/parser
 
-#### Harmony
+#### Support for `const`
 
-If you wish to use the experimental [harmony](https://github.com/mishoo/UglifyJS2/commits/harmony)
-branch to minify ES2015+ (ES6+) code please use the following in your `package.json` file:
-
-```
-"uglify-js": "git+https://github.com/mishoo/UglifyJS2.git#harmony"
-```
-
-or to directly install the experimental harmony version of uglify:
-
-```
-npm install --save-dev uglify-js@github:mishoo/UglifyJS2#harmony
-```
-
-See [#448](https://github.com/mishoo/UglifyJS2/issues/448) for additional details.
+`const` in `uglify-js@2.x` has function scope and as such behaves much like
+`var` - unlike `const` in ES2015 (ES6) which has block scope. It is recommended
+to avoid using `const` for this reason as it will have undefined behavior when
+run on an ES2015 compatible browser.

bin/uglifyjs

@@ -367,19 +367,19 @@ var index = 0;
                     if (ex instanceof UglifyJS.JS_Parse_Error) {
                         print_error("Parse error at " + file + ":" + ex.line + "," + ex.col);
                         var col = ex.col;
-                        var line = code.split(/\r?\n/)[ex.line - (col ? 1 : 2)];
+                        var lines = code.split(/\r?\n/);
+                        var line = lines[ex.line - 1];
+                        if (!line && !col) {
+                            line = lines[ex.line - 2];
+                            col = line.length;
+                        }
                         if (line) {
                             if (col > 40) {
                                 line = line.slice(col - 40);
                                 col = 40;
                             }
-                            if (col) {
                             print_error(line.slice(0, 80));
                             print_error(line.slice(0, col).replace(/\S/g, " ") + "^");
-                            } else {
-                                print_error(line.slice(-40));
-                                print_error(line.slice(-40).replace(/\S/g, " ") + "^");
-                            }
                         }
                         print_error(ex.stack);
                         process.exit(1);

lib/ast.js

@@ -798,8 +798,8 @@ var AST_Object = DEFNODE("Object", "properties", {
 var AST_ObjectProperty = DEFNODE("ObjectProperty", "key value", {
     $documentation: "Base class for literal object properties",
     $propdoc: {
-        key: "[string] the property name converted to a string for ObjectKeyVal.  For setters and getters this is an arbitrary AST_Node.",
-        value: "[AST_Node] property value.  For setters and getters this is an AST_Function."
+        key: "[string] the property name converted to a string for ObjectKeyVal.  For setters and getters this is an AST_SymbolAccessor.",
+        value: "[AST_Node] property value.  For setters and getters this is an AST_Accessor."
     },
     _walk: function(visitor) {
         return visitor._visit(this, function(){

lib/compress.js

@@ -316,9 +316,10 @@ merge(Compressor.prototype, {
                     safe_ids = save_ids;
                     return true;
                 }
+                if (node instanceof AST_Function) {
+                    push();
                     var iife;
-                if (node instanceof AST_Function
-                    && !node.name
+                    if (!node.name
                         && (iife = tw.parent()) instanceof AST_Call
                         && iife.expression === node) {
                         // Virtually turn IIFE parameters into variable definitions:
@@ -326,12 +327,45 @@ merge(Compressor.prototype, {
                         // So existing transformation rules can work on them.
                         node.argnames.forEach(function(arg, i) {
                             var d = arg.definition();
+                            if (!node.uses_arguments && d.fixed === undefined) {
                                 d.fixed = function() {
                                     return iife.args[i] || make_node(AST_Undefined, iife);
                                 };
                                 mark(d, true);
+                            } else {
+                                d.fixed = false;
+                            }
                         });
                     }
+                    descend();
+                    pop();
+                    return true;
+                }
+                if (node instanceof AST_Accessor) {
+                    var save_ids = safe_ids;
+                    safe_ids = Object.create(null);
+                    descend();
+                    safe_ids = save_ids;
+                    return true;
+                }
+                if (node instanceof AST_Binary
+                    && (node.operator == "&&" || node.operator == "||")) {
+                    node.left.walk(tw);
+                    push();
+                    node.right.walk(tw);
+                    pop();
+                    return true;
+                }
+                if (node instanceof AST_Conditional) {
+                    node.condition.walk(tw);
+                    push();
+                    node.consequent.walk(tw);
+                    pop();
+                    push();
+                    node.alternative.walk(tw);
+                    pop();
+                    return true;
+                }
                 if (node instanceof AST_If || node instanceof AST_DWLoop) {
                     node.condition.walk(tw);
                     push();
@@ -414,7 +448,9 @@ merge(Compressor.prototype, {
 
         function reset_def(def) {
             def.escaped = false;
-            if (toplevel || !def.global || def.orig[0] instanceof AST_SymbolConst) {
+            if (def.scope.uses_eval) {
+                def.fixed = false;
+            } else if (toplevel || !def.global || def.orig[0] instanceof AST_SymbolConst) {
                 def.fixed = undefined;
             } else {
                 def.fixed = false;
@@ -440,6 +476,14 @@ merge(Compressor.prototype, {
         return fixed();
     });
 
+    function is_reference_const(ref) {
+        if (!(ref instanceof AST_SymbolRef)) return false;
+        var orig = ref.definition().orig;
+        for (var i = orig.length; --i >= 0;) {
+            if (orig[i] instanceof AST_SymbolConst) return true;
+        }
+    }
+
     function find_variable(compressor, name) {
         var scope, i = 0;
         while (scope = compressor.parent(i++)) {
@@ -1181,12 +1225,12 @@ merge(Compressor.prototype, {
                 && !node.expression.has_side_effects(compressor);
     }
 
-    // may_eq_null()
-    // returns true if this node may evaluate to null or undefined
+    // may_throw_on_access()
+    // returns true if this node may be null, undefined or contain `AST_Accessor`
     (function(def) {
-        AST_Node.DEFMETHOD("may_eq_null", function(compressor) {
+        AST_Node.DEFMETHOD("may_throw_on_access", function(compressor) {
             var pure_getters = compressor.option("pure_getters");
-            return !pure_getters || this._eq_null(pure_getters);
+            return !pure_getters || this._throw_on_access(pure_getters);
         });
 
         function is_strict(pure_getters) {
@@ -1198,7 +1242,12 @@ merge(Compressor.prototype, {
         def(AST_Undefined, return_true);
         def(AST_Constant, return_false);
         def(AST_Array, return_false);
-        def(AST_Object, return_false);
+        def(AST_Object, function(pure_getters) {
+            if (!is_strict(pure_getters)) return false;
+            for (var i = this.properties.length; --i >=0;)
+                if (this.properties[i].value instanceof AST_Accessor) return true;
+            return false;
+        });
         def(AST_Function, return_false);
         def(AST_UnaryPostfix, return_false);
         def(AST_UnaryPrefix, function() {
@@ -1207,33 +1256,33 @@ merge(Compressor.prototype, {
         def(AST_Binary, function(pure_getters) {
             switch (this.operator) {
               case "&&":
-                return this.left._eq_null(pure_getters);
+                return this.left._throw_on_access(pure_getters);
               case "||":
-                return this.left._eq_null(pure_getters)
-                    && this.right._eq_null(pure_getters);
+                return this.left._throw_on_access(pure_getters)
+                    && this.right._throw_on_access(pure_getters);
               default:
                 return false;
             }
         })
         def(AST_Assign, function(pure_getters) {
             return this.operator == "="
-                && this.right._eq_null(pure_getters);
+                && this.right._throw_on_access(pure_getters);
         })
         def(AST_Conditional, function(pure_getters) {
-            return this.consequent._eq_null(pure_getters)
-                || this.alternative._eq_null(pure_getters);
+            return this.consequent._throw_on_access(pure_getters)
+                || this.alternative._throw_on_access(pure_getters);
         })
         def(AST_Seq, function(pure_getters) {
-            return this.cdr._eq_null(pure_getters);
+            return this.cdr._throw_on_access(pure_getters);
         });
         def(AST_SymbolRef, function(pure_getters) {
             if (this.is_undefined) return true;
             if (!is_strict(pure_getters)) return false;
             var fixed = this.fixed_value();
-            return !fixed || fixed._eq_null(pure_getters);
+            return !fixed || fixed._throw_on_access(pure_getters);
         });
     })(function(node, func) {
-        node.DEFMETHOD("_eq_null", func);
+        node.DEFMETHOD("_throw_on_access", func);
     });
 
     /* -----[ boolean/negation helpers ]----- */
@@ -1773,11 +1822,11 @@ merge(Compressor.prototype, {
             return any(this.elements, compressor);
         });
         def(AST_Dot, function(compressor){
-            return this.expression.may_eq_null(compressor)
+            return this.expression.may_throw_on_access(compressor)
                 || this.expression.has_side_effects(compressor);
         });
         def(AST_Sub, function(compressor){
-            return this.expression.may_eq_null(compressor)
+            return this.expression.may_throw_on_access(compressor)
                 || this.expression.has_side_effects(compressor)
                 || this.property.has_side_effects(compressor);
         });
@@ -1909,6 +1958,7 @@ merge(Compressor.prototype, {
                         && node instanceof AST_Assign
                         && node.operator == "="
                         && node.left instanceof AST_SymbolRef
+                        && !is_reference_const(node.left)
                         && scope === self) {
                         node.right.walk(tw);
                         return true;
@@ -2280,6 +2330,7 @@ merge(Compressor.prototype, {
             var args = trim(this.args, compressor, first_in_statement);
             return args && AST_Seq.from_array(args);
         });
+        def(AST_Accessor, return_null);
         def(AST_Function, return_null);
         def(AST_Binary, function(compressor, first_in_statement){
             var right = this.right.drop_side_effect_free(compressor);
@@ -2350,11 +2401,11 @@ merge(Compressor.prototype, {
             return values && AST_Seq.from_array(values);
         });
         def(AST_Dot, function(compressor, first_in_statement){
-            if (this.expression.may_eq_null(compressor)) return this;
+            if (this.expression.may_throw_on_access(compressor)) return this;
             return this.expression.drop_side_effect_free(compressor, first_in_statement);
         });
         def(AST_Sub, function(compressor, first_in_statement){
-            if (this.expression.may_eq_null(compressor)) return this;
+            if (this.expression.may_throw_on_access(compressor)) return this;
             var expression = this.expression.drop_side_effect_free(compressor, first_in_statement);
             if (!expression) return this.property.drop_side_effect_free(compressor, first_in_statement);
             var property = this.property.drop_side_effect_free(compressor);
@@ -3066,7 +3117,8 @@ merge(Compressor.prototype, {
             }
             if (left
                 && !(left instanceof AST_SymbolRef
-                    && left.definition().orig[0] instanceof AST_SymbolLambda)) {
+                    && (left.definition().orig[0] instanceof AST_SymbolLambda
+                        || is_reference_const(left)))) {
                 var parent, field;
                 var cdr = self.cdr;
                 while (true) {

lib/mozilla-ast.js

@@ -111,23 +111,19 @@
         },
         Property: function(M) {
             var key = M.key;
-            var name = key.type == "Identifier" ? key.name : key.value;
             var args = {
                 start    : my_start_token(key),
                 end      : my_end_token(M.value),
-                key      : name,
+                key      : key.type == "Identifier" ? key.name : key.value,
                 value    : from_moz(M.value)
             };
-            switch (M.kind) {
-              case "init":
-                return new AST_ObjectKeyVal(args);
-              case "set":
-                args.value.name = from_moz(key);
-                return new AST_ObjectSetter(args);
-              case "get":
-                args.value.name = from_moz(key);
-                return new AST_ObjectGetter(args);
-            }
+            if (M.kind == "init") return new AST_ObjectKeyVal(args);
+            args.key = new AST_SymbolAccessor({
+                name: args.key
+            });
+            args.value = new AST_Accessor(args.value);
+            if (M.kind == "get") return new AST_ObjectGetter(args);
+            if (M.kind == "set") return new AST_ObjectSetter(args);
         },
         ArrayExpression: function(M) {
             return new AST_Array({
@@ -256,10 +252,7 @@
     map("CallExpression", AST_Call, "callee>expression, arguments@args");
 
     def_to_moz(AST_Toplevel, function To_Moz_Program(M) {
-        return {
-            type: "Program",
-            body: M.body.map(to_moz)
-        };
+        return to_moz_scope("Program", M);
     });
 
     def_to_moz(AST_Defun, function To_Moz_FunctionDeclaration(M) {
@@ -267,7 +260,7 @@
             type: "FunctionDeclaration",
             id: to_moz(M.name),
             params: M.argnames.map(to_moz),
-            body: to_moz_block(M)
+            body: to_moz_scope("BlockStatement", M)
         }
     });
 
@@ -276,7 +269,7 @@
             type: "FunctionExpression",
             id: to_moz(M.name),
             params: M.argnames.map(to_moz),
-            body: to_moz_block(M)
+            body: to_moz_scope("BlockStatement", M)
         }
     });
 
@@ -382,11 +375,10 @@
     });
 
     def_to_moz(AST_ObjectProperty, function To_Moz_Property(M) {
-        var key = (
-            is_identifier(M.key)
-            ? {type: "Identifier", name: M.key}
-            : {type: "Literal", value: M.key}
-        );
+        var key = {
+            type: "Literal",
+            value: M.key instanceof AST_SymbolAccessor ? M.key.name : M.key
+        };
         var kind;
         if (M instanceof AST_ObjectKeyVal) {
             kind = "init";
@@ -547,8 +539,8 @@
         moz_to_me = new Function("U2", "my_start_token", "my_end_token", "from_moz", "return(" + moz_to_me + ")")(
             exports, my_start_token, my_end_token, from_moz
         );
-        me_to_moz = new Function("to_moz", "to_moz_block", "return(" + me_to_moz + ")")(
-            to_moz, to_moz_block
+        me_to_moz = new Function("to_moz", "to_moz_block", "to_moz_scope", "return(" + me_to_moz + ")")(
+            to_moz, to_moz_block, to_moz_scope
         );
         MOZ_TO_ME[moztype] = moz_to_me;
         def_to_moz(mytype, me_to_moz);
@@ -606,4 +598,14 @@
         };
     };
 
+    function to_moz_scope(type, node) {
+        var body = node.body.map(to_moz);
+        if (node.body[0] instanceof AST_SimpleStatement && node.body[0].body instanceof AST_String) {
+            body.unshift(to_moz(new AST_EmptyStatement(node.body[0])));
+        }
+        return {
+            type: type,
+            body: body
+        };
+    };
 })();

lib/parse.js

@@ -111,7 +111,7 @@ var WHITESPACE_CHARS = makePredicate(characters(" \u00a0\n\r\t\f\u000b\u200b\u20
 
 var NEWLINE_CHARS = makePredicate(characters("\n\r\u2028\u2029"));
 
-var PUNC_BEFORE_EXPRESSION = makePredicate(characters("[{(,.;:"));
+var PUNC_BEFORE_EXPRESSION = makePredicate(characters("[{(,;:"));
 
 var PUNC_CHARS = makePredicate(characters("[]{}(),;:"));
 
@@ -285,7 +285,11 @@ function tokenizer($TEXT, filename, html5_comments, shebang) {
         S.regex_allowed = ((type == "operator" && !UNARY_POSTFIX(value)) ||
                            (type == "keyword" && KEYWORDS_BEFORE_EXPRESSION(value)) ||
                            (type == "punc" && PUNC_BEFORE_EXPRESSION(value)));
-        prev_was_dot = (type == "punc" && value == ".");
+        if (type == "punc" && value == ".") {
+            prev_was_dot = true;
+        } else if (!is_comment) {
+            prev_was_dot = false;
+        }
         var ret = {
             type    : type,
             value   : value,
@@ -803,28 +807,23 @@ function parse($TEXT, options) {
     };
 
     var statement = embed_tokens(function() {
-        var tmp;
         handle_regexp();
         switch (S.token.type) {
           case "string":
-            var dir = false;
-            if (S.in_directives === true) {
-                if ((is_token(peek(), "punc", ";") || peek().nlb) && S.token.raw.indexOf("\\") === -1) {
+            if (S.in_directives) {
+                var token = peek();
+                if (S.token.raw.indexOf("\\") == -1
+                    && (token.nlb
+                        || is_token(token, "eof")
+                        || is_token(token, "punc", ";")
+                        || is_token(token, "punc", "}"))) {
                     S.input.add_directive(S.token.value);
                 } else {
                     S.in_directives = false;
                 }
             }
             var dir = S.in_directives, stat = simple_statement();
-            if (dir) {
-                return new AST_Directive({
-                    start : stat.body.start,
-                    end   : stat.body.end,
-                    quote : stat.body.quote,
-                    value : stat.body.value,
-                });
-            }
-            return stat;
+            return dir ? new AST_Directive(stat.body) : stat;
           case "num":
           case "regexp":
           case "operator":
@@ -856,75 +855,103 @@ function parse($TEXT, options) {
             }
 
           case "keyword":
-            switch (tmp = S.token.value, next(), tmp) {
+            switch (S.token.value) {
               case "break":
+                next();
                 return break_cont(AST_Break);
 
               case "continue":
+                next();
                 return break_cont(AST_Continue);
 
               case "debugger":
+                next();
                 semicolon();
                 return new AST_Debugger();
 
               case "do":
+                next();
+                var body = in_loop(statement);
+                expect_token("keyword", "while");
+                var condition = parenthesised();
+                semicolon(true);
                 return new AST_Do({
-                    body      : in_loop(statement),
-                    condition : (expect_token("keyword", "while"), tmp = parenthesised(), semicolon(true), tmp)
+                    body      : body,
+                    condition : condition
                 });
 
               case "while":
+                next();
                 return new AST_While({
                     condition : parenthesised(),
                     body      : in_loop(statement)
                 });
 
               case "for":
+                next();
                 return for_();
 
               case "function":
+                next();
                 return function_(AST_Defun);
 
               case "if":
+                next();
                 return if_();
 
               case "return":
                 if (S.in_function == 0 && !options.bare_returns)
                     croak("'return' outside of function");
+                next();
+                var value = null;
+                if (is("punc", ";")) {
+                    next();
+                } else if (!can_insert_semicolon()) {
+                    value = expression(true);
+                    semicolon();
+                }
                 return new AST_Return({
-                    value: ( is("punc", ";")
-                             ? (next(), null)
-                             : can_insert_semicolon()
-                             ? null
-                             : (tmp = expression(true), semicolon(), tmp) )
+                    value: value
                 });
 
               case "switch":
+                next();
                 return new AST_Switch({
                     expression : parenthesised(),
                     body       : in_loop(switch_body_)
                 });
 
               case "throw":
+                next();
                 if (S.token.nlb)
                     croak("Illegal newline after 'throw'");
+                var value = expression(true);
+                semicolon();
                 return new AST_Throw({
-                    value: (tmp = expression(true), semicolon(), tmp)
+                    value: value
                 });
 
               case "try":
+                next();
                 return try_();
 
               case "var":
-                return tmp = var_(), semicolon(), tmp;
+                next();
+                var node = var_();
+                semicolon();
+                return node;
 
               case "const":
-                return tmp = const_(), semicolon(), tmp;
+                next();
+                var node = const_();
+                semicolon();
+                return node;
 
               case "with":
                 if (S.input.has_directive("use strict")) {
                     croak("Strict mode may not include a with statement");
                 }
+                next();
                 return new AST_With({
                     expression : parenthesised(),
                     body       : statement()
@@ -1320,10 +1347,15 @@ function parse($TEXT, options) {
             var type = start.type;
             var name = as_property_name();
             if (type == "name" && !is("punc", ":")) {
+                var key = new AST_SymbolAccessor({
+                    start: S.token,
+                    name: as_property_name(),
+                    end: prev()
+                });
                 if (name == "get") {
                     a.push(new AST_ObjectGetter({
                         start : start,
-                        key   : as_atom_node(),
+                        key   : key,
                         value : create_accessor(),
                         end   : prev()
                     }));
@@ -1332,7 +1364,7 @@ function parse($TEXT, options) {
                 if (name == "set") {
                     a.push(new AST_ObjectSetter({
                         start : start,
-                        key   : as_atom_node(),
+                        key   : key,
                         value : create_accessor(),
                         end   : prev()
                     }));
@@ -1354,14 +1386,15 @@ function parse($TEXT, options) {
 
     function as_property_name() {
         var tmp = S.token;
-        next();
         switch (tmp.type) {
+          case "operator":
+            if (!KEYWORDS(tmp.value)) unexpected();
           case "num":
           case "string":
           case "name":
-          case "operator":
           case "keyword":
           case "atom":
+            next();
             return tmp.value;
           default:
             unexpected();
@@ -1370,16 +1403,9 @@ function parse($TEXT, options) {
 
     function as_name() {
         var tmp = S.token;
+        if (tmp.type != "name") unexpected();
         next();
-        switch (tmp.type) {
-          case "name":
-          case "operator":
-          case "keyword":
-          case "atom":
         return tmp.value;
-          default:
-            unexpected();
-        }
     };
 
     function _make_symbol(type) {
@@ -1440,14 +1466,14 @@ function parse($TEXT, options) {
         if (is("operator") && UNARY_PREFIX(start.value)) {
             next();
             handle_regexp();
-            var ex = make_unary(AST_UnaryPrefix, start.value, maybe_unary(allow_calls));
+            var ex = make_unary(AST_UnaryPrefix, start, maybe_unary(allow_calls));
             ex.start = start;
             ex.end = prev();
             return ex;
         }
         var val = expr_atom(allow_calls);
         while (is("operator") && UNARY_POSTFIX(S.token.value) && !S.token.nlb) {
-            val = make_unary(AST_UnaryPostfix, S.token.value, val);
+            val = make_unary(AST_UnaryPostfix, S.token, val);
             val.start = start;
             val.end = S.token;
             next();
@@ -1455,9 +1481,10 @@ function parse($TEXT, options) {
         return val;
     };
 
-    function make_unary(ctor, op, expr) {
+    function make_unary(ctor, token, expr) {
+        var op = token.value;
         if ((op == "++" || op == "--") && !is_assignable(expr))
-            croak("Invalid use of " + op + " operator", null, ctor === AST_UnaryPrefix ? expr.start.col - 1 : null);
+            croak("Invalid use of " + op + " operator", token.line, token.col, token.pos);
         return new ctor({ operator: op, expression: expr });
     };
 

lib/scope.js

@@ -361,11 +361,6 @@ AST_Symbol.DEFMETHOD("unmangleable", function(options){
     return this.definition().unmangleable(options);
 });
 
-// property accessors are not mangleable
-AST_SymbolAccessor.DEFMETHOD("unmangleable", function(){
-    return true;
-});
-
 // labels are always mangleable
 AST_Label.DEFMETHOD("unmangleable", function(){
     return false;

package.json

@@ -4,7 +4,7 @@
   "homepage": "http://lisperator.net/uglifyjs",
   "author": "Mihai Bazon <mihai.bazon@gmail.com> (http://lisperator.net/)",
   "license": "BSD-2-Clause",
-  "version": "2.8.23",
+  "version": "2.8.26",
   "engines": {
     "node": ">=0.8.0"
   },
@@ -33,10 +33,7 @@
     "yargs": "~3.10.0"
   },
   "devDependencies": {
-    "acorn": "~0.6.0",
-    "escodegen": "~1.3.3",
-    "esfuzz": "~0.3.1",
-    "estraverse": "~1.5.1",
+    "acorn": "~5.0.3",
     "mocha": "~2.3.4"
   },
   "optionalDependencies": {

test/compress/collapse_vars.js

@@ -1592,3 +1592,49 @@ var_side_effects_3: {
     }
     expect_stdout: true
 }
+
+reassign_const_1: {
+    options = {
+        collapse_vars: true,
+    }
+    input: {
+        function f() {
+            const a = 1;
+            a = 2;
+            return a;
+        }
+        console.log(f());
+    }
+    expect: {
+        function f() {
+            const a = 1;
+            a = 2;
+            return a;
+        }
+        console.log(f());
+    }
+    expect_stdout: true
+}
+
+reassign_const_2: {
+    options = {
+        collapse_vars: true,
+    }
+    input: {
+        function f() {
+            const a = 1;
+            ++a;
+            return a;
+        }
+        console.log(f());
+    }
+    expect: {
+        function f() {
+            const a = 1;
+            ++a;
+            return a;
+        }
+        console.log(f());
+    }
+    expect_stdout: true
+}

test/compress/dead-code.js

@@ -256,3 +256,19 @@ try_catch_finally: {
         "1",
     ]
 }
+
+accessor: {
+    options = {
+        side_effects: true,
+    }
+    input: {
+        ({
+            get a() {},
+            set a(v){
+                this.b = 2;
+            },
+            b: 1
+        });
+    }
+    expect: {}
+}

test/compress/drop-unused.js

@@ -1064,3 +1064,28 @@ issue_1830_2: {
     }
     expect_stdout: "1"
 }
+
+reassign_const: {
+    options = {
+        cascade: true,
+        sequences: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        function f() {
+            const a = 1;
+            a = 2;
+            return a;
+        }
+        console.log(f());
+    }
+    expect: {
+        function f() {
+            const a = 1;
+            return a = 2, a;
+        }
+        console.log(f());
+    }
+    expect_stdout: true
+}

test/compress/issue-1943.js

@@ -0,0 +1,31 @@
+operator: {
+    input: {
+        a. //comment
+        typeof
+    }
+    expect_exact: "a.typeof;"
+}
+
+name: {
+    input: {
+        a. //comment
+        b
+    }
+    expect_exact: "a.b;"
+}
+
+keyword: {
+    input: {
+        a. //comment
+        default
+    }
+    expect_exact: "a.default;"
+}
+
+atom: {
+    input: {
+        a. //comment
+        true
+    }
+    expect_exact: "a.true;"
+}

test/compress/pure_getters.js

@@ -119,3 +119,62 @@ chained: {
         a.b.c;
     }
 }
+
+impure_getter_1: {
+    options = {
+        pure_getters: "strict",
+        side_effects: true,
+    }
+    input: {
+        ({
+            get a() {
+                console.log(1);
+            },
+            b: 1
+        }).a;
+        ({
+            get a() {
+                console.log(1);
+            },
+            b: 1
+        }).b;
+    }
+    expect: {
+        ({
+            get a() {
+                console.log(1);
+            },
+            b: 1
+        }).a;
+        ({
+            get a() {
+                console.log(1);
+            },
+            b: 1
+        }).b;
+    }
+    expect_stdout: "1"
+}
+
+impure_getter_2: {
+    options = {
+        pure_getters: true,
+        side_effects: true,
+    }
+    input: {
+        // will produce incorrect output because getter is not pure
+        ({
+            get a() {
+                console.log(1);
+            },
+            b: 1
+        }).a;
+        ({
+            get a() {
+                console.log(1);
+            },
+            b: 1
+        }).b;
+    }
+    expect: {}
+}

test/compress/reduce_vars.js

@@ -41,22 +41,22 @@ reduce_vars: {
         var A = 1;
         (function() {
             console.log(-3);
-            console.log(-4);
+            console.log(A - 5);
         })();
         (function f1() {
             var a = 2;
-            console.log(-3);
+            console.log(a - 5);
             eval("console.log(a);");
         })();
         (function f2(eval) {
             var a = 2;
-            console.log(-3);
+            console.log(a - 5);
             eval("console.log(a);");
         })(eval);
         (function() {
             return "yes";
         })();
-        console.log(2);
+        console.log(A + 1);
     }
     expect_stdout: true
 }
@@ -1732,7 +1732,10 @@ redefine_arguments_3: {
         console.log(function() {
             var arguments;
             return typeof arguments;
-        }(), "number", "undefined");
+        }(), "number", function(x) {
+            var arguments = x;
+            return typeof arguments;
+        }());
     }
     expect_stdout: "object number undefined"
 }
@@ -2122,3 +2125,76 @@ issue_1865: {
     }
     expect_stdout: true
 }
+
+issue_1922_1: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        console.log(function(a) {
+            arguments[0] = 2;
+            return a;
+        }(1));
+    }
+    expect: {
+        console.log(function(a) {
+            arguments[0] = 2;
+            return a;
+        }(1));
+    }
+    expect_stdout: "2"
+}
+
+issue_1922_2: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        console.log(function() {
+            var a;
+            eval("a = 1");
+            return a;
+        }(1));
+    }
+    expect: {
+        console.log(function() {
+            var a;
+            eval("a = 1");
+            return a;
+        }(1));
+    }
+    expect_stdout: "1"
+}
+
+accessor: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        toplevel: true,
+    }
+    input: {
+        var a = 1;
+        console.log({
+            get a() {
+                a = 2;
+                return a;
+            },
+            b: 1
+        }.b, a);
+    }
+    expect: {
+        var a = 1;
+        console.log({
+            get a() {
+                a = 2;
+                return a;
+            },
+            b: 1
+        }.b, a);
+    }
+    expect_stdout: "1 1"
+}

test/compress/sequences.js

@@ -610,3 +610,27 @@ delete_seq_6: {
     }
     expect_stdout: true
 }
+
+reassign_const: {
+    options = {
+        cascade: true,
+        sequences: true,
+        side_effects: true,
+    }
+    input: {
+        function f() {
+            const a = 1;
+            a++;
+            return a;
+        }
+        console.log(f());
+    }
+    expect: {
+        function f() {
+            const a = 1;
+            return a++, a;
+        }
+        console.log(f());
+    }
+    expect_stdout: true
+}

test/input/invalid/assign_4.js

@@ -0,0 +1 @@
+++null

test/input/invalid/dot_1.js

@@ -0,0 +1 @@
+a.=

test/input/invalid/dot_2.js

@@ -0,0 +1 @@
+%.a;

test/input/invalid/dot_3.js

@@ -0,0 +1 @@
+a./();

test/input/invalid/else.js

@@ -0,0 +1 @@
+if (0) else 1;

test/input/invalid/object.js

@@ -0,0 +1 @@
+console.log({%: 1});

test/input/invalid/return.js

@@ -0,0 +1 @@
+return 42;

test/mocha/accessorTokens-1492.js

@@ -16,7 +16,7 @@ describe("Accessor tokens", function() {
                 assert.equal(node.start.pos, 12);
                 assert.equal(node.end.endpos, 46);
 
-                assert(node.key instanceof UglifyJS.AST_SymbolRef);
+                assert(node.key instanceof UglifyJS.AST_SymbolAccessor);
                 assert.equal(node.key.start.pos, 16);
                 assert.equal(node.key.end.endpos, 22);
 

test/mocha/cli.js

@@ -298,7 +298,7 @@ describe("bin/uglifyjs", function () {
             assert.ok(err);
             assert.strictEqual(stdout, "");
             assert.strictEqual(stderr.split(/\n/).slice(0, 4).join("\n"), [
-               "Parse error at test/input/invalid/assign_3.js:1,18",
+                "Parse error at test/input/invalid/assign_3.js:1,17",
                 "console.log(3 || ++this);",
                 "                 ^",
                 "SyntaxError: Invalid use of ++ operator"
@@ -306,4 +306,109 @@ describe("bin/uglifyjs", function () {
             done();
         });
     });
+    it("Should throw syntax error (++null)", function(done) {
+        var command = uglifyjscmd + ' test/input/invalid/assign_4.js';
+
+        exec(command, function (err, stdout, stderr) {
+            assert.ok(err);
+            assert.strictEqual(stdout, "");
+            assert.strictEqual(stderr.split(/\n/).slice(0, 4).join("\n"), [
+                "Parse error at test/input/invalid/assign_4.js:1,0",
+                "++null",
+                "^",
+                "SyntaxError: Invalid use of ++ operator"
+            ].join("\n"));
+            done();
+        });
+    });
+    it("Should throw syntax error (a.=)", function(done) {
+        var command = uglifyjscmd + ' test/input/invalid/dot_1.js';
+
+        exec(command, function (err, stdout, stderr) {
+            assert.ok(err);
+            assert.strictEqual(stdout, "");
+            assert.strictEqual(stderr.split(/\n/).slice(0, 4).join("\n"), [
+                "Parse error at test/input/invalid/dot_1.js:1,2",
+                "a.=",
+                "  ^",
+                "SyntaxError: Unexpected token: operator (=)"
+            ].join("\n"));
+            done();
+        });
+    });
+    it("Should throw syntax error (%.a)", function(done) {
+        var command = uglifyjscmd + ' test/input/invalid/dot_2.js';
+
+        exec(command, function (err, stdout, stderr) {
+            assert.ok(err);
+            assert.strictEqual(stdout, "");
+            assert.strictEqual(stderr.split(/\n/).slice(0, 4).join("\n"), [
+                "Parse error at test/input/invalid/dot_2.js:1,0",
+                "%.a;",
+                "^",
+                "SyntaxError: Unexpected token: operator (%)"
+            ].join("\n"));
+            done();
+        });
+    });
+    it("Should throw syntax error (a./();)", function(done) {
+        var command = uglifyjscmd + ' test/input/invalid/dot_3.js';
+
+        exec(command, function (err, stdout, stderr) {
+            assert.ok(err);
+            assert.strictEqual(stdout, "");
+            assert.strictEqual(stderr.split(/\n/).slice(0, 4).join("\n"), [
+                "Parse error at test/input/invalid/dot_3.js:1,2",
+                "a./();",
+                "  ^",
+                "SyntaxError: Unexpected token: operator (/)"
+            ].join("\n"));
+            done();
+        });
+    });
+    it("Should throw syntax error ({%: 1})", function(done) {
+        var command = uglifyjscmd + ' test/input/invalid/object.js';
+
+        exec(command, function (err, stdout, stderr) {
+            assert.ok(err);
+            assert.strictEqual(stdout, "");
+            assert.strictEqual(stderr.split(/\n/).slice(0, 4).join("\n"), [
+                "Parse error at test/input/invalid/object.js:1,13",
+                "console.log({%: 1});",
+                "             ^",
+                "SyntaxError: Unexpected token: operator (%)"
+            ].join("\n"));
+            done();
+        });
+    });
+    it("Should throw syntax error (else)", function(done) {
+        var command = uglifyjscmd + ' test/input/invalid/else.js';
+
+        exec(command, function (err, stdout, stderr) {
+            assert.ok(err);
+            assert.strictEqual(stdout, "");
+            assert.strictEqual(stderr.split(/\n/).slice(0, 4).join("\n"), [
+                "Parse error at test/input/invalid/else.js:1,7",
+                "if (0) else 1;",
+                "       ^",
+                "SyntaxError: Unexpected token: keyword (else)"
+            ].join("\n"));
+            done();
+        });
+    });
+    it("Should throw syntax error (return)", function(done) {
+        var command = uglifyjscmd + ' test/input/invalid/return.js';
+
+        exec(command, function (err, stdout, stderr) {
+            assert.ok(err);
+            assert.strictEqual(stdout, "");
+            assert.strictEqual(stderr.split(/\n/).slice(0, 4).join("\n"), [
+                "Parse error at test/input/invalid/return.js:1,0",
+                "return 42;",
+                "^",
+                "SyntaxError: 'return' outside of function"
+            ].join("\n"));
+            done();
+        });
+    });
 });

test/mocha/directives.js

@@ -351,18 +351,28 @@ describe("Directives", function() {
         var tests = [
             [
                 '"use strict";"use strict";"use strict";"use foo";"use strict";;"use sloppy";doSomething("foo");',
-                '"use strict";"use foo";doSomething("foo");'
+                '"use strict";"use foo";doSomething("foo");',
+                'function f(){ "use strict" }',
+                'function f(){ "use asm" }',
+                'function f(){ "use nondirective" }',
+                'function f(){ ;"use strict" }',
+                'function f(){ "use \n"; }',
             ],
             [
                  // Nothing gets optimised in the compressor because "use asm" is the first statement
                 '"use asm";"use\\x20strict";1+1;',
-                '"use asm";;"use strict";1+1;' // Yet, the parser noticed that "use strict" wasn't a directive
+                '"use asm";;"use strict";1+1;', // Yet, the parser noticed that "use strict" wasn't a directive
+                'function f(){"use strict"}',
+                'function f(){"use asm"}',
+                'function f(){"use nondirective"}',
+                'function f(){}',
+                'function f(){}',
             ]
         ];
 
         for (var i = 0; i < tests.length; i++) {
             assert.strictEqual(
-                uglify.minify(tests[i][0], {fromString: true, compress: {collapse_vars: true, side_effects: true}}).code,
+                uglify.minify(tests[i][0], {fromString: true}).code,
                 tests[i][1],
                 tests[i][0]
             );

test/mocha/getter-setter.js

@@ -71,7 +71,7 @@ describe("Getters and setters", function() {
         var fail = function(data) {
             return function (e) {
                 return e instanceof UglifyJS.JS_Parse_Error &&
-                    e.message === "Invalid getter/setter name: " + data.operator;
+                    e.message === "Unexpected token: operator (" + data.operator + ")";
             };
         };
 

test/mozilla-ast.js

@@ -1,103 +1,87 @@
 // Testing UglifyJS <-> SpiderMonkey AST conversion
-// through generative testing.
+"use strict";
 
-var UglifyJS = require(".."),
-    escodegen = require("escodegen"),
-    esfuzz = require("esfuzz"),
-    estraverse = require("estraverse"),
-    prefix = "\r    ";
-
-// Normalizes input AST for UglifyJS in order to get correct comparison.
-
-function normalizeInput(ast) {
-    return estraverse.replace(ast, {
-        enter: function(node, parent) {
-            switch (node.type) {
-                // Internally mark all the properties with semi-standard type "Property".
-                case "ObjectExpression":
-                    node.properties.forEach(function (property) {
-                        property.type = "Property";
-                    });
-                    break;
-
-                // Since UglifyJS doesn"t recognize different types of property keys,
-                // decision on SpiderMonkey node type is based on check whether key
-                // can be valid identifier or not - so we do in input AST.
-                case "Property":
-                    var key = node.key;
-                    if (key.type === "Literal" && typeof key.value === "string" && UglifyJS.is_identifier(key.value)) {
-                        node.key = {
-                            type: "Identifier",
-                            name: key.value
-                        };
-                    } else if (key.type === "Identifier" && !UglifyJS.is_identifier(key.name)) {
-                        node.key = {
-                            type: "Literal",
-                            value: key.name
-                        };
-                    }
-                    break;
-
-                // UglifyJS internally flattens all the expression sequences - either
-                // to one element (if sequence contains only one element) or flat list.
-                case "SequenceExpression":
-                    node.expressions = node.expressions.reduce(function flatten(list, expr) {
-                        return list.concat(expr.type === "SequenceExpression" ? expr.expressions.reduce(flatten, []) : [expr]);
-                    }, []);
-                    if (node.expressions.length === 1) {
-                        return node.expressions[0];
-                    }
-                    break;
-            }
-        }
-    });
-}
-
-module.exports = function(options) {
-    console.log("--- UglifyJS <-> Mozilla AST conversion");
-
-    for (var counter = 0; counter < options.iterations; counter++) {
-        process.stdout.write(prefix + counter + "/" + options.iterations);
-
-        var ast1 = normalizeInput(esfuzz.generate({
-            maxDepth: options.maxDepth
-        }));
-
-        var ast2 =
-            UglifyJS
-            .AST_Node
-            .from_mozilla_ast(ast1)
-            .to_mozilla_ast();
-
-        var astPair = [
-            {name: 'expected', value: ast1},
-            {name: 'actual', value: ast2}
-        ];
-
-        var jsPair = astPair.map(function(item) {
-            return {
-                name: item.name,
-                value: escodegen.generate(item.value)
-            }
-        });
-
-        if (jsPair[0].value !== jsPair[1].value) {
-            var fs = require("fs");
 var acorn = require("acorn");
+var ufuzz = require("./ufuzz");
+var UglifyJS = require("..");
 
-            fs.existsSync("tmp") || fs.mkdirSync("tmp");
-
-            jsPair.forEach(function (item) {
-                var fileName = "tmp/dump_" + item.name;
-                var ast = acorn.parse(item.value);
-                fs.writeFileSync(fileName + ".js", item.value);
-                fs.writeFileSync(fileName + ".json", JSON.stringify(ast, null, 2));
+function try_beautify(code) {
+    var beautified;
+    try {
+        beautified = UglifyJS.minify(code, {
+            fromString: true,
+            compress: false,
+            mangle: false,
+            output: {
+                beautify: true,
+                bracketize: true
+            }
         });
-
-            process.stdout.write("\n");
-            throw new Error("Got different outputs, check out tmp/dump_*.{js,json} for codes and ASTs.");
+    } catch (ex) {
+        beautified = { error: ex };
+    }
+    if (beautified.error) {
+        console.log("// !!! beautify failed !!!");
+        console.log(beautified.error.stack);
+        console.log(code);
+    } else {
+        console.log("// (beautified)");
+        console.log(beautified.code);
     }
 }
 
-    process.stdout.write(prefix + "Probability of error is less than " + (100 / options.iterations) + "%, stopping.\n");
+function test(original, estree, description) {
+    var transformed;
+    try {
+        transformed = UglifyJS.minify(estree, {
+            fromString: true,
+            compress: false,
+            mangle: false,
+            spidermonkey: true
+        });
+    } catch (ex) {
+        transformed = { error: ex };
+    }
+    if (transformed.error || original !== transformed.code) {
+        console.log("//=============================================================");
+        console.log("// !!!!!! Failed... round", round);
+        console.log("// original code");
+        try_beautify(original);
+        console.log();
+        console.log();
+        console.log("//-------------------------------------------------------------");
+        console.log("//", description);
+        if (transformed.error) {
+            console.log(transformed.error.stack);
+        } else {
+            try_beautify(transformed.code);
+        }
+        console.log("!!!!!! Failed... round", round);
+        process.exit(1);
+    }
+}
+
+var num_iterations = ufuzz.num_iterations;
+for (var round = 1; round <= num_iterations; round++) {
+    process.stdout.write(round + " of " + num_iterations + "\r");
+    var code = ufuzz.createTopLevelCode();
+    var uglified = {
+        ast: UglifyJS.parse(code),
+        code: UglifyJS.minify(code, {
+            fromString: true,
+            compress: false,
+            mangle: false
+        }).code
     };
+    test(uglified.code, uglified.ast.to_mozilla_ast(), "AST_Node.to_mozilla_ast()");
+    try {
+        test(uglified.code, acorn.parse(code), "acorn.parse()");
+    } catch (e) {
+        console.log("//=============================================================");
+        console.log("// acorn parser failed... round", round);
+        console.log(e);
+        console.log("// original code");
+        console.log(code);
+    }
+}
+console.log();

test/run-tests.js

@@ -23,12 +23,6 @@ mocha_tests();
 var run_sourcemaps_tests = require('./sourcemaps');
 run_sourcemaps_tests();
 
-var run_ast_conversion_tests = require("./mozilla-ast");
-
-run_ast_conversion_tests({
-    iterations: 1000
-});
-
 /* -----[ utils ]----- */
 
 function tmpl() {

test/sandbox.js

@@ -1,14 +1,16 @@
 var vm = require("vm");
 
-function safe_log(arg) {
+function safe_log(arg, level) {
     if (arg) switch (typeof arg) {
       case "function":
         return arg.toString();
       case "object":
         if (/Error$/.test(arg.name)) return arg.toString();
         arg.constructor.toString();
-        for (var key in arg) {
-            arg[key] = safe_log(arg[key]);
+        if (level--) for (var key in arg) {
+            if (!Object.getOwnPropertyDescriptor(arg, key).get) {
+                arg[key] = safe_log(arg[key], level);
+            }
         }
     }
     return arg;
@@ -48,7 +50,9 @@ exports.run_code = function(code) {
         ].join("\n"), {
             console: {
                 log: function() {
-                    return console.log.apply(console, [].map.call(arguments, safe_log));
+                    return console.log.apply(console, [].map.call(arguments, function(arg) {
+                        return safe_log(arg, 3);
+                    }));
                 }
             }
         }, { timeout: 5000 });

test/ufuzz.js

@@ -48,8 +48,9 @@ var STMT_COUNT_FROM_GLOBAL = true; // count statement depth from nearest functio
 var num_iterations = +process.argv[2] || 1/0;
 var verbose = false; // log every generated test
 var verbose_interval = false; // log every 100 generated tests
-var verbose_error = false;
 var use_strict = false;
+var catch_redef = require.main === module;
+var generate_directive = require.main === module;
 for (var i = 2; i < process.argv.length; ++i) {
     switch (process.argv[i]) {
       case '-v':
@@ -58,9 +59,6 @@ for (var i = 2; i < process.argv.length; ++i) {
       case '-V':
         verbose_interval = true;
         break;
-      case '-E':
-        verbose_error = true;
-        break;
       case '-t':
         MAX_GENERATED_TOPLEVELS_PER_RUN = +process.argv[++i];
         if (!MAX_GENERATED_TOPLEVELS_PER_RUN) throw new Error('Must generate at least one toplevel per run');
@@ -79,6 +77,12 @@ for (var i = 2; i < process.argv.length; ++i) {
         STMT_SECOND_LEVEL_OVERRIDE = STMT_ARG_TO_ID[name];
         if (!(STMT_SECOND_LEVEL_OVERRIDE >= 0)) throw new Error('Unknown statement name; use -? to get a list');
         break;
+      case '--no-catch-redef':
+        catch_redef = false;
+        break;
+      case '--no-directive':
+        generate_directive = false;
+        break;
       case '--use-strict':
         use_strict = true;
         break;
@@ -103,11 +107,12 @@ for (var i = 2; i < process.argv.length; ++i) {
         console.log('<number>: generate this many cases (if used must be first arg)');
         console.log('-v: print every generated test case');
         console.log('-V: print every 100th generated test case');
-        console.log('-E: print generated test case with runtime error');
         console.log('-t <int>: generate this many toplevels per run (more take longer)');
         console.log('-r <int>: maximum recursion depth for generator (higher takes longer)');
         console.log('-s1 <statement name>: force the first level statement to be this one (see list below)');
         console.log('-s2 <statement name>: force the second level statement to be this one (see list below)');
+        console.log('--no-catch-redef: do not redefine catch variables');
+        console.log('--no-directive: do not generate directives');
         console.log('--use-strict: generate "use strict"');
         console.log('--stmt-depth-from-func: reset statement depth counter at each function, counts from global otherwise');
         console.log('--only-stmt <statement names>: a comma delimited white list of statements that may be generated');
@@ -192,12 +197,33 @@ var ASSIGNMENTS = [
     '=',
     '=',
     '=',
+    '=',
+    '=',
+    '=',
+    '=',
+
+    '=',
+    '=',
+    '=',
+    '=',
+    '=',
+    '=',
+    '=',
+    '=',
+    '=',
+    '=',
 
-    '==',
-    '!=',
-    '===',
-    '!==',
     '+=',
+    '+=',
+    '+=',
+    '+=',
+    '+=',
+    '+=',
+    '+=',
+    '+=',
+    '+=',
+    '+=',
+
     '-=',
     '*=',
     '/=',
@@ -207,7 +233,8 @@ var ASSIGNMENTS = [
     '<<=',
     '>>=',
     '>>>=',
-    '%=' ];
+    '%=',
+];
 
 var UNARY_SAFE = [
     '+',
@@ -276,6 +303,7 @@ var TYPEOF_OUTCOMES = [
     'symbol',
     'crap' ];
 
+var unique_vars = [];
 var loops = 0;
 var funcs = 0;
 var labels = 10000;
@@ -290,6 +318,10 @@ function strictMode() {
 }
 
 function createTopLevelCode() {
+    VAR_NAMES.length = INITIAL_NAMES_LEN; // prune any previous names still in the list
+    unique_vars.length = 0;
+    loops = 0;
+    funcs = 0;
     return [
         strictMode(),
         'var a = 100, b = 10, c = 0;',
@@ -325,33 +357,36 @@ function createArgs() {
     return args.join(', ');
 }
 
+function filterDirective(s) {
+    if (!generate_directive && !s[1] && /\("/.test(s[2])) s[2] = ';' + s[2];
+    return s;
+}
+
 function createFunction(recurmax, inGlobal, noDecl, canThrow, stmtDepth) {
     if (--recurmax < 0) { return ';'; }
     if (!STMT_COUNT_FROM_GLOBAL) stmtDepth = 0;
     var func = funcs++;
     var namesLenBefore = VAR_NAMES.length;
-    var name = (inGlobal || rng(5) > 0) ? 'f' + func : createVarName(MANDATORY, noDecl);
-    if (name === 'a' || name === 'b' || name === 'c') name = 'f' + func; // quick hack to prevent assignment to func names of being called
-    var s = '';
+    var name;
+    if (inGlobal || rng(5) > 0) name = 'f' + func;
+    else {
+        unique_vars.push('a', 'b', 'c');
+        name = createVarName(MANDATORY, noDecl);
+        unique_vars.length -= 3;
+    }
+    var s = [
+        'function ' + name + '(' + createParams() + '){',
+        strictMode()
+    ];
     if (rng(5) === 0) {
         // functions with functions. lower the recursion to prevent a mess.
-        s = [
-            'function ' + name + '(' + createParams() + '){',
-            strictMode(),
-            createFunctions(rng(5) + 1, Math.ceil(recurmax * 0.7), NOT_GLOBAL, ANY_TYPE, canThrow, stmtDepth),
-            '}',
-            ''
-        ].join('\n');
+        s.push(createFunctions(rng(5) + 1, Math.ceil(recurmax * 0.7), NOT_GLOBAL, ANY_TYPE, canThrow, stmtDepth));
     } else {
         // functions with statements
-        s = [
-            'function ' + name + '(' + createParams() + '){',
-            strictMode(),
-            createStatements(3, recurmax, canThrow, CANNOT_BREAK, CANNOT_CONTINUE, CAN_RETURN, stmtDepth),
-            '}',
-            ''
-        ].join('\n');
+        s.push(createStatements(3, recurmax, canThrow, CANNOT_BREAK, CANNOT_CONTINUE, CAN_RETURN, stmtDepth));
     }
+    s.push('}', '');
+    s = filterDirective(s).join('\n');
 
     VAR_NAMES.length = namesLenBefore;
 
@@ -359,7 +394,6 @@ function createFunction(recurmax, inGlobal, noDecl, canThrow, stmtDepth) {
     // avoid "function statements" (decl inside statements)
     else if (inGlobal || rng(10) > 0) s += 'var ' + createVarName(MANDATORY) + ' = ' + name + '(' + createArgs() + ');';
 
-
     return s;
 }
 
@@ -406,7 +440,7 @@ function getLabel(label) {
     return label && " L" + label;
 }
 
-function createStatement(recurmax, canThrow, canBreak, canContinue, cannotReturn, stmtDepth) {
+function createStatement(recurmax, canThrow, canBreak, canContinue, cannotReturn, stmtDepth, target) {
     ++stmtDepth;
     var loop = ++loops;
     if (--recurmax < 0) {
@@ -414,10 +448,11 @@ function createStatement(recurmax, canThrow, canBreak, canContinue, cannotReturn
     }
 
     // allow to forcefully generate certain structures at first or second recursion level
-    var target = 0;
+    if (target === undefined) {
         if (stmtDepth === 1 && STMT_FIRST_LEVEL_OVERRIDE >= 0) target = STMT_FIRST_LEVEL_OVERRIDE;
         else if (stmtDepth === 2 && STMT_SECOND_LEVEL_OVERRIDE >= 0) target = STMT_SECOND_LEVEL_OVERRIDE;
         else target = STMTS_TO_USE[rng(STMTS_TO_USE.length)];
+    }
 
     switch (target) {
       case STMT_BLOCK:
@@ -460,20 +495,22 @@ function createStatement(recurmax, canThrow, canBreak, canContinue, cannotReturn
       case STMT_VAR:
         switch (rng(3)) {
           case 0:
+            unique_vars.push('c');
             var name = createVarName(MANDATORY);
-            if (name === 'c') name = 'a';
+            unique_vars.pop();
             return 'var ' + name + ';';
           case 1:
             // initializer can only have one expression
+            unique_vars.push('c');
             var name = createVarName(MANDATORY);
-            if (name === 'c') name = 'b';
+            unique_vars.pop();
             return 'var ' + name + ' = ' + createExpression(recurmax, NO_COMMA, stmtDepth, canThrow) + ';';
           default:
             // initializer can only have one expression
+            unique_vars.push('c');
             var n1 = createVarName(MANDATORY);
-            if (n1 === 'c') n1 = 'b';
             var n2 = createVarName(MANDATORY);
-            if (n2 === 'c') n2 = 'b';
+            unique_vars.pop();
             return 'var ' + n1 + ' = ' + createExpression(recurmax, NO_COMMA, stmtDepth, canThrow) + ', ' + n2 + ' = ' + createExpression(recurmax, NO_COMMA, stmtDepth, canThrow) + ';';
         }
       case STMT_RETURN_ETC:
@@ -514,8 +551,11 @@ function createStatement(recurmax, canThrow, canBreak, canContinue, cannotReturn
             var nameLenBefore = VAR_NAMES.length;
             var catchName = createVarName(MANDATORY);
             var freshCatchName = VAR_NAMES.length !== nameLenBefore;
+            if (!catch_redef) unique_vars.push(catchName);
             s += ' catch (' + catchName + ') { ' + createStatements(3, recurmax, canThrow, canBreak, canContinue, cannotReturn, stmtDepth) + ' }';
-            if (freshCatchName) VAR_NAMES.splice(nameLenBefore, 1); // remove catch name
+            // remove catch name
+            if (!catch_redef) unique_vars.pop();
+            if (freshCatchName) VAR_NAMES.splice(nameLenBefore, 1);
         }
         if (n !== 0) s += ' finally { ' + createStatements(3, recurmax, canThrow, canBreak, canContinue, cannotReturn, stmtDepth) + ' }';
         return s;
@@ -593,8 +633,9 @@ function _createExpression(recurmax, noComma, stmtDepth, canThrow) {
       case p++:
       case p++:
         var nameLenBefore = VAR_NAMES.length;
+        unique_vars.push('c');
         var name = createVarName(MAYBE); // note: this name is only accessible from _within_ the function. and immutable at that.
-        if (name == 'c') name = 'a';
+        unique_vars.pop();
         var s = [];
         switch (rng(5)) {
           case 0:
@@ -636,7 +677,7 @@ function _createExpression(recurmax, noComma, stmtDepth, canThrow) {
                 strictMode()
             );
             if (instantiate) for (var i = rng(4); --i >= 0;) {
-                if (rng(2)) s.push('this.' + getDotKey() + createAssignment() + _createBinaryExpr(recurmax, noComma, stmtDepth, canThrow) + ';');
+                if (rng(2)) s.push('this.' + getDotKey(true) + createAssignment() + _createBinaryExpr(recurmax, noComma, stmtDepth, canThrow) + ';');
                 else  s.push('this[' + createExpression(recurmax, COMMA_OK, stmtDepth, canThrow) + ']' + createAssignment() + _createBinaryExpr(recurmax, noComma, stmtDepth, canThrow) + ';');
             }
             s.push(
@@ -646,7 +687,7 @@ function _createExpression(recurmax, noComma, stmtDepth, canThrow) {
             break;
         }
         VAR_NAMES.length = nameLenBefore;
-        return s.join('\n');
+        return filterDirective(s).join('\n');
       case p++:
       case p++:
         return createTypeofExpr(recurmax, stmtDepth, canThrow);
@@ -689,19 +730,19 @@ function _createExpression(recurmax, noComma, stmtDepth, canThrow) {
             ") || " + rng(10) + ").toString()[" +
             createExpression(recurmax, COMMA_OK, stmtDepth, canThrow) + "] ";
       case p++:
-        return createArrayLiteral(recurmax, COMMA_OK, stmtDepth, canThrow);
+        return createArrayLiteral(recurmax, stmtDepth, canThrow);
       case p++:
-        return createObjectLiteral(recurmax, COMMA_OK, stmtDepth, canThrow);
+        return createObjectLiteral(recurmax, stmtDepth, canThrow);
       case p++:
-        return createArrayLiteral(recurmax, COMMA_OK, stmtDepth, canThrow) + '[' +
+        return createArrayLiteral(recurmax, stmtDepth, canThrow) + '[' +
             createExpression(recurmax, COMMA_OK, stmtDepth, canThrow) + ']';
       case p++:
-        return createObjectLiteral(recurmax, COMMA_OK, stmtDepth, canThrow) + '[' +
+        return createObjectLiteral(recurmax, stmtDepth, canThrow) + '[' +
             createExpression(recurmax, COMMA_OK, stmtDepth, canThrow) + ']';
       case p++:
-        return createArrayLiteral(recurmax, COMMA_OK, stmtDepth, canThrow) + '.' + getDotKey();
+        return createArrayLiteral(recurmax, stmtDepth, canThrow) + '.' + getDotKey();
       case p++:
-        return createObjectLiteral(recurmax, COMMA_OK, stmtDepth, canThrow) + '.' + getDotKey();
+        return createObjectLiteral(recurmax, stmtDepth, canThrow) + '.' + getDotKey();
       case p++:
         var name = getVarName();
         return name + ' && ' + name + '[' + createExpression(recurmax, COMMA_OK, stmtDepth, canThrow) + ']';
@@ -713,7 +754,7 @@ function _createExpression(recurmax, noComma, stmtDepth, canThrow) {
     return _createExpression(recurmax, noComma, stmtDepth, canThrow);
 }
 
-function createArrayLiteral(recurmax, noComma, stmtDepth, canThrow) {
+function createArrayLiteral(recurmax, stmtDepth, canThrow) {
     recurmax--;
     var arr = "[";
     for (var i = rng(6); --i >= 0;) {
@@ -746,18 +787,56 @@ var KEYS = [
     "3",
 ].concat(SAFE_KEYS);
 
-function getDotKey() {
-    return SAFE_KEYS[rng(SAFE_KEYS.length)];
+function getDotKey(assign) {
+    var key;
+    do {
+        key = SAFE_KEYS[rng(SAFE_KEYS.length)];
+    } while (assign && key == "length");
+    return key;
 }
 
-function createObjectLiteral(recurmax, noComma, stmtDepth, canThrow) {
-    recurmax--;
-    var obj = "({";
-    for (var i = rng(6); --i >= 0;) {
-        var key = KEYS[rng(KEYS.length)];
-        obj += key + ":(" + createExpression(recurmax, COMMA_OK, stmtDepth, canThrow) + "), ";
+function createAccessor(recurmax, stmtDepth, canThrow) {
+    var namesLenBefore = VAR_NAMES.length;
+    var s;
+    var prop1 = getDotKey();
+    if (rng(2) == 0) {
+        s = [
+            'get ' + prop1 + '(){',
+            strictMode(),
+            createStatements(2, recurmax, canThrow, CANNOT_BREAK, CANNOT_CONTINUE, CAN_RETURN, stmtDepth),
+            createStatement(recurmax, canThrow, CANNOT_BREAK, CANNOT_CONTINUE, CAN_RETURN, stmtDepth, STMT_RETURN_ETC),
+            '},'
+        ];
+    } else {
+        var prop2;
+        do {
+            prop2 = getDotKey();
+        } while (prop1 == prop2);
+        s = [
+            'set ' + prop1 + '(' + createVarName(MANDATORY) + '){',
+            strictMode(),
+            createStatements(2, recurmax, canThrow, CANNOT_BREAK, CANNOT_CONTINUE, CAN_RETURN, stmtDepth),
+            'this.' + prop2 + createAssignment() + _createBinaryExpr(recurmax, COMMA_OK, stmtDepth, canThrow) + ';',
+            '},'
+        ];
     }
-    return obj + "})";
+    VAR_NAMES.length = namesLenBefore;
+    return filterDirective(s).join('\n');
+}
+
+function createObjectLiteral(recurmax, stmtDepth, canThrow) {
+    recurmax--;
+    var obj = ['({'];
+    for (var i = rng(6); --i >= 0;) {
+        if (rng(20) == 0) {
+            obj.push(createAccessor(recurmax, stmtDepth, canThrow));
+        } else {
+            var key = KEYS[rng(KEYS.length)];
+            obj.push(key + ':(' + createExpression(recurmax, COMMA_OK, stmtDepth, canThrow) + '),');
+        }
+    }
+    obj.push('})');
+    return obj.join('\n');
 }
 
 function createNestedBinaryExpr(recurmax, noComma, stmtDepth, canThrow) {
@@ -787,7 +866,7 @@ function _createSimpleBinaryExpr(recurmax, noComma, stmtDepth, canThrow) {
         return canThrow && rng(10) == 0 ? expr : '(' + assignee + ' && ' + expr + ')';
       case 4:
         assignee = getVarName();
-        expr = '(' + assignee + '.' + getDotKey() + createAssignment()
+        expr = '(' + assignee + '.' + getDotKey(true) + createAssignment()
             + _createBinaryExpr(recurmax, noComma, stmtDepth, canThrow) + ')';
         return canThrow && rng(10) == 0 ? expr : '(' + assignee + ' && ' + expr + ')';
       default:
@@ -844,17 +923,24 @@ function getVarName() {
 
 function createVarName(maybe, dontStore) {
     if (!maybe || rng(2)) {
-        var name = VAR_NAMES[rng(VAR_NAMES.length)];
         var suffix = rng(3);
-        if (suffix) {
-            name += '_' + suffix;
-            if (!dontStore) VAR_NAMES.push(name);
-        }
+        var name;
+        do {
+            name = VAR_NAMES[rng(VAR_NAMES.length)];
+            if (suffix) name += '_' + suffix;
+        } while (unique_vars.indexOf(name) >= 0);
+        if (suffix && !dontStore) VAR_NAMES.push(name);
         return name;
     }
     return '';
 }
 
+if (require.main !== module) {
+    exports.createTopLevelCode = createTopLevelCode;
+    exports.num_iterations = num_iterations;
+    return;
+}
+
 function try_beautify(code, result) {
     try {
         var beautified = UglifyJS.minify(code, {
@@ -978,10 +1064,6 @@ var uglify_code, uglify_result, ok;
 for (var round = 1; round <= num_iterations; round++) {
     process.stdout.write(round + " of " + num_iterations + "\r");
 
-    VAR_NAMES.length = INITIAL_NAMES_LEN; // prune any previous names still in the list
-    loops = 0;
-    funcs = 0;
-
     original_code = createTopLevelCode();
     original_result = sandbox.run_code(original_code);
     (typeof original_result != "string" ? fallback_options : minify_options).forEach(function(options) {
@@ -999,7 +1081,7 @@ for (var round = 1; round <= num_iterations; round++) {
             ok = uglify_code.name == original_result.name;
         }
         if (verbose || (verbose_interval && !(round % INTERVAL_COUNT)) || !ok) log(options);
-        else if (verbose_error && typeof original_result != "string") {
+        else if (typeof original_result != "string") {
             console.log("//=============================================================");
             console.log("// original code");
             try_beautify(original_code, original_result);