v3.5.7

fixes #3377

README.md

@@ -636,6 +636,9 @@ If you're using the `X-SourceMap` header instead, you can just omit `sourceMap.u
 - `expression` (default: `false`) -- Pass `true` to preserve completion values
   from terminal statements without `return`, e.g. in bookmarklets.
 
+- `functions` (default: `true`) -- convert declarations from `var`to `function`
+  whenever possible.
+
 - `global_defs` (default: `{}`) -- see [conditional compilation](#conditional-compilation)
 
 - `hoist_funs` (default: `false`) -- hoist function declarations

lib/ast.js

@@ -773,7 +773,7 @@ var AST_Label = DEFNODE("Label", "references", {
     }
 }, AST_Symbol);
 
-var AST_SymbolRef = DEFNODE("SymbolRef", null, {
+var AST_SymbolRef = DEFNODE("SymbolRef", "fixed", {
     $documentation: "Reference to some symbol (not definition/declaration)",
 }, AST_Symbol);
 

lib/compress.js

@@ -60,6 +60,7 @@ function Compressor(options, false_by_default) {
         drop_debugger   : !false_by_default,
         evaluate        : !false_by_default,
         expression      : false,
+        functions       : !false_by_default,
         global_defs     : false,
         hoist_funs      : false,
         hoist_props     : !false_by_default,
@@ -113,7 +114,7 @@ function Compressor(options, false_by_default) {
         };
     } else if (Array.isArray(pure_funcs)) {
         this.pure_funcs = function(node) {
-            return pure_funcs.indexOf(node.expression.print_to_string()) < 0;
+            return !member(node.expression.print_to_string(), pure_funcs);
         };
     } else {
         this.pure_funcs = return_true;
@@ -130,7 +131,7 @@ function Compressor(options, false_by_default) {
             top_retain = top_retain.split(/,/);
         }
         this.top_retain = function(def) {
-            return top_retain.indexOf(def.name) >= 0;
+            return member(def.name, top_retain);
         };
     }
     var toplevel = this.options["toplevel"];
@@ -150,7 +151,7 @@ Compressor.prototype = new TreeTransformer;
 merge(Compressor.prototype, {
     option: function(key) { return this.options[key] },
     exposed: function(def) {
-        if (def.global) for (var i = 0, len = def.orig.length; i < len; i++)
+        if (def.global) for (var i = 0; i < def.orig.length; i++)
             if (!this.toplevel[def.orig[i] instanceof AST_SymbolDefun ? "funcs" : "vars"])
                 return true;
         return false;
@@ -311,8 +312,22 @@ merge(Compressor.prototype, {
         return value instanceof AST_SymbolRef && value.fixed_value() || value;
     }
 
+    function is_read_only_fn(value, name) {
+        if (value instanceof AST_Boolean) return native_fns.Boolean[name];
+        if (value instanceof AST_Number) return native_fns.Number[name];
+        if (value instanceof AST_String) return native_fns.String[name];
+        if (name == "valueOf") return false;
+        if (value instanceof AST_Array) return native_fns.Array[name];
+        if (value instanceof AST_Function) return native_fns.Function[name];
+        if (value instanceof AST_Object) return native_fns.Object[name];
+        if (value instanceof AST_RegExp) return native_fns.RegExp[name];
+    }
+
     function is_modified(compressor, tw, node, value, level, immutable) {
         var parent = tw.parent(level);
+        if (compressor.option("unsafe") && parent instanceof AST_Dot && is_read_only_fn(value, parent.property)) {
+            return;
+        }
         var lhs = is_lhs(node, parent);
         if (lhs) return lhs;
         if (!immutable
@@ -343,7 +358,7 @@ merge(Compressor.prototype, {
             def.assignments = 0;
             def.chained = false;
             def.direct_access = false;
-            def.escaped = false;
+            def.escaped = [];
             def.fixed = !def.scope.pinned()
                 && !compressor.exposed(def)
                 && !(def.init instanceof AST_Function && def.init !== def.scope)
@@ -482,8 +497,9 @@ merge(Compressor.prototype, {
                 || parent instanceof AST_Call && (node !== parent.expression || parent instanceof AST_New)
                 || parent instanceof AST_Exit && node === parent.value && node.scope !== d.scope
                 || parent instanceof AST_VarDef && node === parent.value) {
+                d.escaped.push(parent);
                 if (depth > 1 && !(value && value.is_constant_expression(scope))) depth = 1;
-                if (!d.escaped || d.escaped > depth) d.escaped = depth;
+                if (!d.escaped.depth || d.escaped.depth > depth) d.escaped.depth = depth;
                 return;
             } else if (parent instanceof AST_Array
                 || parent instanceof AST_Binary && lazy_op[parent.operator]
@@ -535,6 +551,7 @@ merge(Compressor.prototype, {
                 mark_assignment_to_arguments(sym);
                 return;
             }
+            if (sym.fixed) delete sym.fixed;
             var d = sym.definition();
             var safe = safe_to_assign(tw, d, sym.scope, node.right);
             d.assignments++;
@@ -544,7 +561,7 @@ merge(Compressor.prototype, {
             var value = eq ? node.right : node;
             if (is_modified(compressor, tw, node, value, 0)) return;
             if (!eq) d.chained = true;
-            d.fixed = eq ? function() {
+            sym.fixed = d.fixed = eq ? function() {
                 return node.right;
             } : function() {
                 return make_node(AST_Binary, node, {
@@ -558,7 +575,7 @@ merge(Compressor.prototype, {
             mark(tw, d, false);
             node.right.walk(tw);
             mark(tw, d, true);
-            mark_escaped(tw, d, sym.scope, node, value, 0, 1);
+            if (eq) mark_escaped(tw, d, sym.scope, node, value, 0, 1);
             return true;
         });
         def(AST_Binary, function(tw) {
@@ -714,6 +731,7 @@ merge(Compressor.prototype, {
             this.definition().fixed = false;
         });
         def(AST_SymbolRef, function(tw, descend, compressor) {
+            if (this.fixed) delete this.fixed;
             var d = this.definition();
             d.references.push(this);
             if (d.references.length == 1
@@ -726,7 +744,7 @@ merge(Compressor.prototype, {
                 d.fixed = false;
             } else if (d.fixed) {
                 value = this.fixed_value();
-                if (value instanceof AST_Lambda && recursive_ref(tw, d)) {
+                if (recursive_ref(tw, d)) {
                     d.recursive_refs++;
                 } else if (value && ref_once(tw, compressor, d)) {
                     d.single_use = value instanceof AST_Lambda && !value.pinned()
@@ -741,8 +759,8 @@ merge(Compressor.prototype, {
                         d.fixed = false;
                     }
                 }
+                mark_escaped(tw, d, this.scope, this, value, 0, 1);
             }
-            mark_escaped(tw, d, this.scope, this, value, 0, 1);
             var parent;
             if (d.fixed instanceof AST_Defun
                 && !((parent = tw.parent()) instanceof AST_Call && parent.expression === this)) {
@@ -781,13 +799,14 @@ merge(Compressor.prototype, {
                 mark_assignment_to_arguments(exp);
                 return;
             }
+            if (exp.fixed) delete exp.fixed;
             var d = exp.definition();
             var safe = safe_to_assign(tw, d, exp.scope, true);
             d.assignments++;
             var fixed = d.fixed;
             if (!fixed) return;
             d.chained = true;
-            d.fixed = function() {
+            exp.fixed = d.fixed = function() {
                 return make_node(AST_Binary, node, {
                     operator: node.operator.slice(0, -1),
                     left: make_node(AST_UnaryPrefix, node, {
@@ -858,10 +877,11 @@ merge(Compressor.prototype, {
         this.walk(tw);
     });
 
-    AST_Symbol.DEFMETHOD("fixed_value", function() {
+    AST_Symbol.DEFMETHOD("fixed_value", function(final) {
         var fixed = this.definition().fixed;
-        if (!fixed || fixed instanceof AST_Node) return fixed;
-        return fixed();
+        if (!fixed) return fixed;
+        if (!final && this.fixed) fixed = this.fixed;
+        return fixed instanceof AST_Node ? fixed : fixed();
     });
 
     AST_SymbolRef.DEFMETHOD("is_immutable", function() {
@@ -1241,7 +1261,7 @@ merge(Compressor.prototype, {
                 // Scan case expressions first in a switch statement
                 if (node instanceof AST_Switch) {
                     node.expression = node.expression.transform(scanner);
-                    for (var i = 0, len = node.body.length; !abort && i < len; i++) {
+                    for (var i = 0; !abort && i < node.body.length; i++) {
                         var branch = node.body[i];
                         if (branch instanceof AST_Case) {
                             if (!hit) {
@@ -1271,7 +1291,9 @@ merge(Compressor.prototype, {
                 if (node instanceof AST_Try) return true;
                 if (node instanceof AST_With) return true;
                 if (replace_all) return false;
-                return node instanceof AST_SymbolRef && !node.is_declared(compressor);
+                return node instanceof AST_SymbolRef
+                    && !node.is_declared(compressor)
+                    && !(parent instanceof AST_Assign && parent.left === node);
             }
 
             function in_conditional(node, parent) {
@@ -1578,9 +1600,14 @@ merge(Compressor.prototype, {
                     lvalues[candidate.name.name] = lhs;
                 }
                 var tw = new TreeWalker(function(node) {
-                    var sym = root_expr(node);
-                    if (sym instanceof AST_SymbolRef || sym instanceof AST_This) {
-                        lvalues[sym.name] = lvalues[sym.name] || is_modified(compressor, tw, node, node, 0);
+                    var value;
+                    if (node instanceof AST_SymbolRef) {
+                        value = node.fixed_value() || node;
+                    } else if (node instanceof AST_This) {
+                        value = node;
+                    }
+                    if (value && !lvalues[node.name]) {
+                        lvalues[node.name] = is_modified(compressor, tw, node, value, 0);
                     }
                 });
                 expr.walk(tw);
@@ -1690,7 +1717,7 @@ merge(Compressor.prototype, {
                     CHANGED = true;
                     statements.splice(i, 1);
                 } else if (stat instanceof AST_Directive) {
-                    if (seen_dirs.indexOf(stat.value) < 0) {
+                    if (!member(stat.value, seen_dirs)) {
                         i++;
                         seen_dirs.push(stat.value);
                     } else {
@@ -1887,7 +1914,7 @@ merge(Compressor.prototype, {
             }
 
             function next_index(i) {
-                for (var j = i + 1, len = statements.length; j < len; j++) {
+                for (var j = i + 1; j < statements.length; j++) {
                     var stat = statements[j];
                     if (!(stat instanceof AST_Var && declarations_only(stat))) {
                         break;
@@ -1978,7 +2005,7 @@ merge(Compressor.prototype, {
         function to_simple_statement(block, decls) {
             if (!(block instanceof AST_BlockStatement)) return block;
             var stat = null;
-            for (var i = 0, len = block.body.length; i < len; i++) {
+            for (var i = 0; i < block.body.length; i++) {
                 var line = block.body[i];
                 if (line instanceof AST_Var && declarations_only(line)) {
                     decls.push(line);
@@ -2118,7 +2145,7 @@ merge(Compressor.prototype, {
 
         function join_consecutive_vars(statements) {
             var defs;
-            for (var i = 0, j = -1, len = statements.length; i < len; i++) {
+            for (var i = 0, j = -1; i < statements.length; i++) {
                 var stat = statements[i];
                 var prev = statements[j];
                 if (stat instanceof AST_Definitions) {
@@ -2576,9 +2603,9 @@ merge(Compressor.prototype, {
     }
 
     function convert_to_predicate(obj) {
-        for (var key in obj) {
+        Object.keys(obj).forEach(function(key) {
             obj[key] = makePredicate(obj[key]);
-        }
+        });
     }
 
     var object_fns = [
@@ -2719,7 +2746,7 @@ merge(Compressor.prototype, {
         def(AST_Array, function(compressor, cached, depth) {
             if (compressor.option("unsafe")) {
                 var elements = [];
-                for (var i = 0, len = this.elements.length; i < len; i++) {
+                for (var i = 0; i < this.elements.length; i++) {
                     var element = this.elements[i];
                     var value = element._eval(compressor, cached, depth);
                     if (element === value) return this;
@@ -2732,7 +2759,7 @@ merge(Compressor.prototype, {
         def(AST_Object, function(compressor, cached, depth) {
             if (compressor.option("unsafe")) {
                 var val = {};
-                for (var i = 0, len = this.properties.length; i < len; i++) {
+                for (var i = 0; i < this.properties.length; i++) {
                     var prop = this.properties[i];
                     var key = prop.key;
                     if (key instanceof AST_Symbol) {
@@ -2832,7 +2859,7 @@ merge(Compressor.prototype, {
             var fixed = this.fixed_value();
             if (!fixed) return this;
             var value;
-            if (cached.indexOf(fixed) >= 0) {
+            if (member(fixed, cached)) {
                 value = fixed._eval();
             } else {
                 this._eval = return_this;
@@ -2846,9 +2873,25 @@ merge(Compressor.prototype, {
             }
             if (value && typeof value == "object") {
                 var escaped = this.definition().escaped;
-                if (escaped && depth > escaped) return this;
+                switch (escaped.length) {
+                  case 0:
+                    break;
+                  case 1:
+                    if (contains_ref(escaped[0], this)) break;
+                  default:
+                    if (depth > escaped.depth) return this;
+                }
             }
             return value;
+
+            function contains_ref(expr, ref) {
+                var found = false;
+                expr.walk(new TreeWalker(function(node) {
+                    if (found) return true;
+                    if (node === ref) return found = true;
+                }));
+                return found;
+            }
         });
         var global_objs = {
             Array: Array,
@@ -2927,7 +2970,7 @@ merge(Compressor.prototype, {
                     if (!native_fn || !native_fn[key]) return this;
                 }
                 var args = [];
-                for (var i = 0, len = this.args.length; i < len; i++) {
+                for (var i = 0; i < this.args.length; i++) {
                     var arg = this.args[i];
                     var value = arg._eval(compressor, cached, depth);
                     if (arg === value) return this;
@@ -3463,9 +3506,7 @@ merge(Compressor.prototype, {
             if (node instanceof AST_Definitions && scope === self) {
                 node.definitions.forEach(function(def) {
                     var node_def = def.name.definition();
-                    if (def.name instanceof AST_SymbolVar) {
-                        var_defs_by_id.add(node_def.id, def);
-                    }
+                    var_defs_by_id.add(node_def.id, def);
                     if (!drop_vars) {
                         if (!(node_def.id in in_use_ids)) {
                             in_use_ids[node_def.id] = true;
@@ -3477,7 +3518,7 @@ merge(Compressor.prototype, {
                         if (def.value.has_side_effects(compressor)) {
                             def.value.walk(tw);
                         }
-                        if (!node_def.chained && def.name.fixed_value() === def.value) {
+                        if (!node_def.chained && def.name.fixed_value(true) === def.value) {
                             fixed_ids[node_def.id] = def;
                         }
                     }
@@ -3572,29 +3613,49 @@ merge(Compressor.prototype, {
                         if (def.value && sym.id in fixed_ids && fixed_ids[sym.id] !== def) {
                             def.value = def.value.drop_side_effect_free(compressor);
                         }
-                        if (def.name instanceof AST_SymbolVar) {
-                            var var_defs = var_defs_by_id.get(sym.id);
-                            if (var_defs.length > 1 && (!def.value || sym.orig.indexOf(def.name) > sym.eliminated)) {
-                                compressor.warn("Dropping duplicated definition of variable {name} [{file}:{line},{col}]", template(def.name));
-                                if (def.value) {
-                                    var ref = make_node(AST_SymbolRef, def.name, def.name);
-                                    sym.references.push(ref);
-                                    var assign = make_node(AST_Assign, def, {
-                                        operator: "=",
-                                        left: ref,
-                                        right: def.value
-                                    });
-                                    if (fixed_ids[sym.id] === def) {
-                                        fixed_ids[sym.id] = assign;
-                                    }
-                                    side_effects.push(assign.transform(tt));
+                        var var_defs = var_defs_by_id.get(sym.id);
+                        if (var_defs.length > 1 && (!def.value || sym.orig.indexOf(def.name) > sym.eliminated)) {
+                            compressor.warn("Dropping duplicated definition of variable {name} [{file}:{line},{col}]", template(def.name));
+                            if (def.value) {
+                                var ref = make_node(AST_SymbolRef, def.name, def.name);
+                                sym.references.push(ref);
+                                var assign = make_node(AST_Assign, def, {
+                                    operator: "=",
+                                    left: ref,
+                                    right: def.value
+                                });
+                                if (fixed_ids[sym.id] === def) {
+                                    fixed_ids[sym.id] = assign;
                                 }
-                                remove(var_defs, def);
-                                sym.eliminated++;
-                                return;
+                                side_effects.push(assign.transform(tt));
                             }
+                            remove(var_defs, def);
+                            sym.eliminated++;
+                            return;
                         }
-                        if (def.value) {
+                        if (!def.value) {
+                            head.push(def);
+                        } else if (compressor.option("functions")
+                            && def.value === def.name.fixed_value()
+                            && def.value instanceof AST_Function
+                            && can_rename(def.value, def.name.name)
+                            && (!compressor.has_directive("use strict") || parent instanceof AST_Scope)) {
+                            compressor.warn("Declaring {name} as function [{file}:{line},{col}]", template(def.name));
+                            var defun = make_node(AST_Defun, def, def.value);
+                            defun.name = make_node(AST_SymbolDefun, def.name, def.name);
+                            var name_def = def.name.scope.resolve().def_function(defun.name);
+                            if (def.value.name) {
+                                var old_def = def.value.name.definition();
+                                def.value.walk(new TreeWalker(function(node) {
+                                    if (node instanceof AST_SymbolRef && node.definition() === old_def) {
+                                        node.name = name_def.name;
+                                        node.thedef = name_def;
+                                        node.reference({});
+                                    }
+                                }));
+                            }
+                            body.push(defun);
+                        } else {
                             if (side_effects.length > 0) {
                                 if (tail.length > 0) {
                                     side_effects.push(def.value);
@@ -3607,8 +3668,6 @@ merge(Compressor.prototype, {
                                 side_effects = [];
                             }
                             tail.push(def);
-                        } else {
-                            head.push(def);
                         }
                     } else if (sym.orig[0] instanceof AST_SymbolCatch) {
                         var value = def.value && def.value.drop_side_effect_free(compressor);
@@ -3625,6 +3684,11 @@ merge(Compressor.prototype, {
                         }
                         sym.eliminated++;
                     }
+
+                    function can_rename(fn, name) {
+                        var def = fn.variables.get(name);
+                        return !def || fn.name && def === fn.name.definition();
+                    }
                 });
                 if (head.length > 0 || tail.length > 0) {
                     node.definitions = head.concat(tail);
@@ -3650,6 +3714,7 @@ merge(Compressor.prototype, {
             //    https://github.com/mishoo/UglifyJS2/issues/44
             //    https://github.com/mishoo/UglifyJS2/issues/1830
             //    https://github.com/mishoo/UglifyJS2/issues/1838
+            //    https://github.com/mishoo/UglifyJS2/issues/3371
             // that's an invalid AST.
             // We fix it at this stage by moving the `var` outside the `for`.
             if (node instanceof AST_For) {
@@ -3660,7 +3725,15 @@ merge(Compressor.prototype, {
                     node.init = block.body.pop();
                     block.body.push(node);
                 }
-                if (node.init instanceof AST_SimpleStatement) {
+                if (node.init instanceof AST_Defun) {
+                    if (!block) {
+                        block = make_node(AST_BlockStatement, node, {
+                            body: [ node ]
+                        });
+                    }
+                    block.body.splice(-1, 0, node.init);
+                    node.init = null;
+                } else if (node.init instanceof AST_SimpleStatement) {
                     node.init = node.init.body;
                 } else if (is_empty(node.init)) {
                     node.init = null;
@@ -3716,7 +3789,7 @@ merge(Compressor.prototype, {
                 if (node instanceof AST_Assign) {
                     node.right.walk(tw);
                     if (node.left === sym) {
-                        if (!node_def.chained && sym.fixed_value() === node.right) {
+                        if (!node_def.chained && sym.fixed_value(true) === node.right) {
                             fixed_ids[node_def.id] = node;
                         }
                         if (!node.write_only) {
@@ -3966,7 +4039,7 @@ merge(Compressor.prototype, {
                 var def = sym.definition();
                 if (def.assignments != count) return;
                 if (def.direct_access) return;
-                if (def.escaped == 1) return;
+                if (def.escaped.depth == 1) return;
                 if (def.references.length == count) return;
                 if (def.single_use) return;
                 if (top_retain(def)) return;
@@ -4669,7 +4742,7 @@ merge(Compressor.prototype, {
             && !fn.uses_arguments
             && !fn.pinned()) {
             var pos = 0, last = 0;
-            for (var i = 0, len = self.args.length; i < len; i++) {
+            for (var i = 0; i < self.args.length; i++) {
                 var trim = i >= fn.argnames.length;
                 if (trim || fn.argnames[i].__unused) {
                     var node = self.args[i].drop_side_effect_free(compressor);
@@ -5035,7 +5108,7 @@ merge(Compressor.prototype, {
                     })) {
                         return false;
                     }
-                } else if (line instanceof AST_EmptyStatement) {
+                } else if (line instanceof AST_Defun || line instanceof AST_EmptyStatement) {
                     continue;
                 } else if (stat) {
                     return false;
@@ -5046,33 +5119,32 @@ merge(Compressor.prototype, {
             return return_value(stat);
         }
 
+        function var_exists(catches, name) {
+            return catches[name] || identifier_atom[name] || scope.var_names()[name];
+        }
+
         function can_inject_args(catches, safe_to_inject) {
-            for (var i = 0, len = fn.argnames.length; i < len; i++) {
+            for (var i = 0; i < fn.argnames.length; i++) {
                 var arg = fn.argnames[i];
                 if (arg.__unused) continue;
-                if (!safe_to_inject
-                    || catches[arg.name]
-                    || identifier_atom[arg.name]
-                    || scope.var_names()[arg.name]) {
-                    return false;
-                }
+                if (!safe_to_inject || var_exists(catches, arg.name)) return false;
                 if (in_loop) in_loop.push(arg.definition());
             }
             return true;
         }
 
         function can_inject_vars(catches, safe_to_inject) {
-            for (var i = 0, len = fn.body.length; i < len; i++) {
+            for (var i = 0; i < fn.body.length; i++) {
                 var stat = fn.body[i];
+                if (stat instanceof AST_Defun) {
+                    if (!safe_to_inject || var_exists(catches, stat.name.name)) return false;
+                    continue;
+                }
                 if (!(stat instanceof AST_Var)) continue;
                 if (!safe_to_inject) return false;
                 for (var j = stat.definitions.length; --j >= 0;) {
                     var name = stat.definitions[j].name;
-                    if (catches[name.name]
-                        || identifier_atom[name.name]
-                        || scope.var_names()[name.name]) {
-                        return false;
-                    }
+                    if (var_exists(catches, name.name)) return false;
                     if (in_loop) in_loop.push(name.definition());
                 }
             }
@@ -5142,10 +5214,10 @@ merge(Compressor.prototype, {
 
         function flatten_vars(decls, expressions) {
             var pos = expressions.length;
-            for (var i = 0, lines = fn.body.length; i < lines; i++) {
+            for (var i = 0; i < fn.body.length; i++) {
                 var stat = fn.body[i];
                 if (!(stat instanceof AST_Var)) continue;
-                for (var j = 0, defs = stat.definitions.length; j < defs; j++) {
+                for (var j = 0; j < stat.definitions.length; j++) {
                     var var_def = stat.definitions[j];
                     var name = var_def.name;
                     var redef = name.definition().redefined();
@@ -5176,12 +5248,21 @@ merge(Compressor.prototype, {
             flatten_args(decls, expressions);
             flatten_vars(decls, expressions);
             expressions.push(value);
-            if (decls.length) {
-                i = scope.body.indexOf(compressor.parent(level - 1)) + 1;
-                scope.body.splice(i, 0, make_node(AST_Var, fn, {
-                    definitions: decls
-                }));
-            }
+            var args = fn.body.filter(function(stat) {
+                if (stat instanceof AST_Defun) {
+                    var def = stat.name.definition();
+                    scope.functions.set(def.name, def);
+                    scope.variables.set(def.name, def);
+                    scope.enclosed.push(def);
+                    scope.var_names()[def.name] = true;
+                    return true;
+                }
+            });
+            args.unshift(scope.body.indexOf(compressor.parent(level - 1)) + 1, 0);
+            if (decls.length) args.push(make_node(AST_Var, fn, {
+                definitions: decls
+            }));
+            [].splice.apply(scope.body, args);
             return expressions;
         }
     });
@@ -5846,7 +5927,7 @@ merge(Compressor.prototype, {
             var single_use = def.single_use && !(parent instanceof AST_Call && parent.is_expr_pure(compressor));
             if (single_use && fixed instanceof AST_Lambda) {
                 if (def.scope !== self.scope
-                    && (!compressor.option("reduce_funcs") || def.escaped == 1 || fixed.inlined)) {
+                    && (!compressor.option("reduce_funcs") || def.escaped.depth == 1 || fixed.inlined)) {
                     single_use = false;
                 } else if (recursive_ref(compressor, def)) {
                     single_use = false;

lib/output.js

@@ -123,7 +123,7 @@ function OutputStream(options) {
         });
     } : function(str) {
         var s = "";
-        for (var i = 0, len = str.length; i < len; i++) {
+        for (var i = 0; i < str.length; i++) {
             if (is_surrogate_pair_head(str[i]) && !is_surrogate_pair_tail(str[i + 1])
                 || is_surrogate_pair_tail(str[i]) && !is_surrogate_pair_head(str[i - 1])) {
                 s += "\\u" + str.charCodeAt(i).toString(16);

lib/parse.js

@@ -164,10 +164,6 @@ function is_unicode_connector_punctuation(ch) {
     return UNICODE.connector_punctuation.test(ch);
 }
 
-function is_identifier(name) {
-    return !RESERVED_WORDS[name] && /^[a-z_$][a-z0-9_$]*$/i.test(name);
-}
-
 function is_identifier_start(code) {
     return code == 36 || code == 95 || is_letter(code);
 }
@@ -272,10 +268,8 @@ function tokenizer($TEXT, filename, html5_comments, shebang) {
 
     function find_eol() {
         var text = S.text;
-        for (var i = S.pos, n = S.text.length; i < n; ++i) {
-            var ch = text[i];
-            if (NEWLINE_CHARS[ch])
-                return i;
+        for (var i = S.pos; i < S.text.length; ++i) {
+            if (NEWLINE_CHARS[text[i]]) return i;
         }
         return -1;
     }

lib/scope.js

@@ -61,8 +61,6 @@ SymbolDef.next_id = 1;
 
 SymbolDef.prototype = {
     unmangleable: function(options) {
-        if (!options) options = {};
-
         return this.global && !options.toplevel
             || this.undeclared
             || !options.eval && this.scope.pinned()
@@ -198,24 +196,20 @@ AST_Toplevel.DEFMETHOD("figure_out_scope", function(options) {
         }
         if (node instanceof AST_SymbolLambda) {
             var def = node.thedef;
-            if (def.orig.length == 1) {
-                redefine(node, node.scope.parent_scope);
-                node.thedef.init = def.init;
-            }
+            redefine(node, node.scope.parent_scope);
+            node.thedef.init = def.init;
             return true;
         }
     }));
 
     function redefine(node, scope) {
         var name = node.name;
-        var refs = node.thedef.references;
-        var def = scope.find_variable(name) || self.globals.get(name) || scope.def_variable(node);
-        refs.forEach(function(ref) {
-            ref.thedef = def;
-            ref.reference(options);
+        var old_def = node.thedef;
+        var new_def = scope.find_variable(name) || self.globals.get(name) || scope.def_variable(node);
+        old_def.orig.concat(old_def.references).forEach(function(node) {
+            node.thedef = new_def;
+            node.reference(options);
         });
-        node.thedef = def;
-        node.reference(options);
     }
 });
 
@@ -300,7 +294,7 @@ AST_Scope.DEFMETHOD("def_variable", function(symbol, init) {
 
 AST_Lambda.DEFMETHOD("resolve", return_this);
 AST_Scope.DEFMETHOD("resolve", function() {
-    return this.parent_scope;
+    return this.parent_scope.resolve();
 });
 AST_Toplevel.DEFMETHOD("resolve", return_this);
 
@@ -337,7 +331,7 @@ function next_mangled_name(scope, options, def) {
         } while (scope = scope.parent_scope);
     });
     var name;
-    for (var i = 0, len = holes.length; i < len; i++) {
+    for (var i = 0; i < holes.length; i++) {
         name = base54(holes[i]);
         if (names[name]) continue;
         holes.splice(i, 1);
@@ -346,7 +340,7 @@ function next_mangled_name(scope, options, def) {
     }
     while (true) {
         name = base54(++scope.cname);
-        if (in_use[name] || !is_identifier(name) || options.reserved.has[name]) continue;
+        if (in_use[name] || RESERVED_WORDS[name] || options.reserved.has[name]) continue;
         if (!names[name]) break;
         holes.push(scope.cname);
     }
@@ -426,7 +420,7 @@ AST_Toplevel.DEFMETHOD("mangle_names", function(options) {
             var name;
             do {
                 name = base54(++lname);
-            } while (!is_identifier(name));
+            } while (RESERVED_WORDS[name]);
             node.mangled_name = name;
             return true;
         }
@@ -497,7 +491,7 @@ AST_Toplevel.DEFMETHOD("expand_names", function(options) {
         var name;
         do {
             name = base54(cname++);
-        } while (avoid[name] || !is_identifier(name));
+        } while (avoid[name] || RESERVED_WORDS[name]);
         return name;
     }
 
@@ -559,7 +553,7 @@ var base54 = (function() {
     var freq = Object.create(null);
     function init(chars) {
         var array = [];
-        for (var i = 0, len = chars.length; i < len; i++) {
+        for (var i = 0; i < chars.length; i++) {
             var ch = chars[i];
             array.push(ch);
             freq[ch] = -1e-2 * i;

package.json

@@ -3,7 +3,7 @@
   "description": "JavaScript parser, mangler/compressor and beautifier toolkit",
   "author": "Mihai Bazon <mihai.bazon@gmail.com> (http://lisperator.net/)",
   "license": "BSD-2-Clause",
-  "version": "3.5.2",
+  "version": "3.5.7",
   "engines": {
     "node": ">=0.8.0"
   },
@@ -23,12 +23,12 @@
     "LICENSE"
   ],
   "dependencies": {
-    "commander": "~2.19.0",
+    "commander": "~2.20.0",
     "source-map": "~0.6.1"
   },
   "devDependencies": {
     "acorn": "~6.1.1",
-    "semver": "~5.6.0"
+    "semver": "~6.0.0"
   },
   "scripts": {
     "test": "node test/run-tests.js"

test/compress/assignment.js

@@ -289,3 +289,25 @@ increment_decrement_2: {
     }
     expect_stdout: "42"
 }
+
+issue_3375: {
+    options = {
+        assignments: true,
+        reduce_vars: true,
+    }
+    input: {
+        console.log(typeof function(b) {
+            var a = b += 1;
+            --b;
+            return a;
+        }("object"));
+    }
+    expect: {
+        console.log(typeof function(b) {
+            var a = b += 1;
+            --b;
+            return a;
+        }("object"));
+    }
+    expect_stdout: "string"
+}

test/compress/collapse_vars.js

@@ -6157,3 +6157,24 @@ sub_property: {
     }
     expect_stdout: "PASS"
 }
+
+assign_undeclared: {
+    options = {
+        collapse_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var A = (console.log(42), function() {});
+        B = new A();
+        console.log(typeof B);
+    }
+    expect: {
+        B = new (console.log(42), function() {})();
+        console.log(typeof B);
+    }
+    expect_stdout: [
+        "42",
+        "object",
+    ]
+}

test/compress/drop-unused.js

@@ -2005,3 +2005,24 @@ issue_3233: {
     }
     expect_stdout: "PASS"
 }
+
+issue_3375: {
+    options = {
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var b = 1;
+        var a = c = [], c = --b + ("function" == typeof f && f());
+        var a = c && c[a];
+        console.log(a, b);
+    }
+    expect: {
+        var b = 1;
+        var a = [], c = --b + ("function" == typeof f && f());
+        a = c && c[a];
+        console.log(a, b);
+    }
+    expect_stdout: "0 0"
+}

test/compress/evaluate.js

@@ -1124,14 +1124,14 @@ issue_2207_1: {
         console.log(Math.max(3, 6, 2, 7, 3, 4));
         console.log(Math.cos(1.2345));
         console.log(Math.cos(1.2345) - Math.sin(4.321));
-        console.log(Math.pow(Math.PI, Math.E - Math.LN10));
+        console.log(Math.pow(Math.PI, Math.E - Math.LN10).toFixed(15));
     }
     expect: {
         console.log("A");
         console.log(7);
         console.log(Math.cos(1.2345));
         console.log(1.2543732512566947);
-        console.log(1.6093984514472044);
+        console.log("1.609398451447204");
     }
     expect_stdout: true
 }
@@ -1687,3 +1687,28 @@ try_increment: {
     }
     expect_stdout: "1"
 }
+
+unsafe_escaped: {
+    options = {
+        evaluate: true,
+        inline: true,
+        passes: 3,
+        reduce_vars: true,
+        side_effects: true,
+        unsafe: true,
+        unused: true,
+    }
+    input: {
+        (function(a) {
+            console.log(function(index) {
+                return a[index];
+            }(function(term) {
+                return a.indexOf(term);
+            }("PASS")));
+        })([ "PASS" ]);
+    }
+    expect: {
+        console.log("PASS");
+    }
+    expect_stdout: "PASS"
+}

test/compress/functions.js

@@ -2703,3 +2703,365 @@ loop_inline: {
     }
     expect_stdout: "undefined"
 }
+
+functions: {
+    options = {
+        functions: true,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        !function() {
+            var a = function a() {
+                return a && "a";
+            };
+            var b = function x() {
+                return !!x;
+            };
+            var c = function(c) {
+                return c;
+            };
+            if (c(b(a()))) {
+                var d = function() {};
+                var e = function y() {
+                    return typeof y;
+                };
+                var f = function(f) {
+                    return f;
+                };
+                console.log(a(d()), b(e()), c(f(42)), typeof d, e(), typeof f);
+            }
+        }();
+    }
+    expect: {
+        !function() {
+            function a() {
+                return a && "a";
+            }
+            function b() {
+                return !!b;
+            }
+            var c = function(c) {
+                return c;
+            };
+            if (c(b(a()))) {
+                function d() {}
+                function e() {
+                    return typeof e;
+                }
+                var f = function(f) {
+                    return f;
+                };
+                console.log(a(d()), b(e()), c(f(42)), typeof d, e(), typeof f);
+            }
+        }();
+    }
+    expect_stdout: "a true 42 function function function"
+}
+
+functions_use_strict: {
+    options = {
+        functions: true,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        "use strict";
+        !function() {
+            var a = function a() {
+                return a && "a";
+            };
+            var b = function x() {
+                return !!x;
+            };
+            var c = function(c) {
+                return c;
+            };
+            if (c(b(a()))) {
+                var d = function() {};
+                var e = function y() {
+                    return typeof y;
+                };
+                var f = function(f) {
+                    return f;
+                };
+                console.log(a(d()), b(e()), c(f(42)), typeof d, e(), typeof f);
+            }
+        }();
+    }
+    expect: {
+        "use strict";
+        !function() {
+            function a() {
+                return a && "a";
+            }
+            function b() {
+                return !!b;
+            }
+            var c = function(c) {
+                return c;
+            };
+            if (c(b(a()))) {
+                var d = function() {};
+                var e = function y() {
+                    return typeof y;
+                };
+                var f = function(f) {
+                    return f;
+                };
+                console.log(a(d()), b(e()), c(f(42)), typeof d, e(), typeof f);
+            }
+        }();
+    }
+    expect_stdout: "a true 42 function function function"
+}
+
+issue_2437: {
+    options = {
+        collapse_vars: true,
+        conditionals: true,
+        functions: true,
+        inline: true,
+        join_vars: true,
+        passes: 2,
+        reduce_funcs: true,
+        reduce_vars: true,
+        sequences: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        function foo() {
+            return bar();
+        }
+        function bar() {
+            if (xhrDesc) {
+                var req = new XMLHttpRequest();
+                var result = !!req.onreadystatechange;
+                Object.defineProperty(XMLHttpRequest.prototype, 'onreadystatechange', xhrDesc || {});
+                return result;
+            } else {
+                var req = new XMLHttpRequest();
+                var detectFunc = function(){};
+                req.onreadystatechange = detectFunc;
+                var result = req[SYMBOL_FAKE_ONREADYSTATECHANGE_1] === detectFunc;
+                req.onreadystatechange = null;
+                return result;
+            }
+        }
+        console.log(foo());
+    }
+    expect: {
+        console.log(function() {
+            if (xhrDesc) {
+                var result = !!(req = new XMLHttpRequest()).onreadystatechange;
+                return Object.defineProperty(XMLHttpRequest.prototype, "onreadystatechange", xhrDesc || {}),
+                    result;
+            }
+            function detectFunc() {}
+            var req;
+            (req = new XMLHttpRequest()).onreadystatechange = detectFunc;
+            result = req[SYMBOL_FAKE_ONREADYSTATECHANGE_1] === detectFunc;
+            return req.onreadystatechange = null, result;
+        }());
+    }
+}
+
+issue_2485: {
+    options = {
+        functions: true,
+        reduce_funcs: true,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        var foo = function(bar) {
+            var n = function(a, b) {
+                return a + b;
+            };
+            var sumAll = function(arg) {
+                return arg.reduce(n, 0);
+            };
+            var runSumAll = function(arg) {
+                return sumAll(arg);
+            };
+            bar.baz = function(arg) {
+                var n = runSumAll(arg);
+                return (n.get = 1), n;
+            };
+            return bar;
+        };
+        var bar = foo({});
+        console.log(bar.baz([1, 2, 3]));
+    }
+    expect: {
+        var foo = function(bar) {
+            function n(a, b) {
+                return a + b;
+            }
+            function runSumAll(arg) {
+                return function(arg) {
+                    return arg.reduce(n, 0);
+                }(arg);
+            }
+            bar.baz = function(arg) {
+                var n = runSumAll(arg);
+                return (n.get = 1), n;
+            };
+            return bar;
+        };
+        var bar = foo({});
+        console.log(bar.baz([1, 2, 3]));
+    }
+    expect_stdout: "6"
+}
+
+issue_3364: {
+    options = {
+        functions: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    mangle = {}
+    input: {
+        var s = 2, a = 100, b = 10, c = 0;
+        function f(p, e, r) {
+            try {
+                for (var i = 1; i-- > 0;)
+                    var a = function(x) {
+                        function g(y) {
+                            y && y[a++];
+                        }
+                        var x = g(--s >= 0 && f(c++));
+                        for (var j = 1; --j > 0;);
+                    }();
+            } catch (e) {
+                try {
+                    return;
+                } catch (z) {
+                    for (var k = 1; --k > 0;) {
+                        for (var l = 1; l > 0; --l) {
+                            var n = function() {};
+                            for (var k in n)
+                                var o = (n, k);
+                        }
+                    }
+                }
+            }
+        }
+        var r = f();
+        console.log(c);
+    }
+    expect: {
+        var s = 2, c = 0;
+        (function n(r, o, a) {
+            try {
+                for (var f = 1; f-- >0;)
+                    var t = function(r) {
+                        (function(r) {
+                            r && r[t++];
+                        })(--s >= 0 && n(c++));
+                        for (var o = 1; --o > 0;);
+                    }();
+            } catch (o) {
+                try {
+                    return;
+                } catch (r) {
+                    for (var v = 1; --v > 0;)
+                        for (var i = 1; i > 0;--i) {
+                            function u() {}
+                            for (var v in u);
+                        }
+                }
+            }
+        })();
+        console.log(c);
+    }
+    expect_stdout: "2"
+}
+
+issue_3366: {
+    options = {
+        functions: true,
+        inline: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        function f() {
+            function g() {
+                return function() {};
+            }
+            var a = g();
+            (function() {
+                this && a && console.log("PASS");
+            })();
+        }
+        f();
+    }
+    expect: {
+        void function() {
+            this && a && console.log("PASS");
+        }();
+        function a() {}
+    }
+    expect_stdout: "PASS"
+}
+
+issue_3371: {
+    options = {
+        functions: true,
+        inline: true,
+        reduce_vars: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        (function() {
+            var a = function f() {
+                (function() {
+                    console.log(typeof f);
+                })();
+            };
+            while (a());
+        })();
+    }
+    expect: {
+        (function() {
+            function a() {
+                console.log(typeof a);
+            }
+            while (a());
+        })();
+    }
+    expect_stdout: "function"
+}
+
+class_iife: {
+    options = {
+        inline: true,
+        sequences: true,
+        toplevel: true,
+    }
+    input: {
+        var A = function() {
+            function B() {}
+            B.prototype.m = function() {
+                console.log("PASS");
+            };
+            return B;
+        }();
+        new A().m();
+    }
+    expect: {
+        var A = (B.prototype.m = function() {
+            console.log("PASS");
+        }, B);
+        function B() {}
+        new A().m();
+    }
+    expect_stdout: "PASS"
+}

test/compress/ie8.js

@@ -861,3 +861,111 @@ issue_3215_4: {
     }
     expect_stdout: "PASS"
 }
+
+issue_3355_1: {
+    mangle = {
+        ie8: false,
+    }
+    input: {
+        (function f() {
+            var f;
+        })();
+        (function g() {
+        })();
+        console.log(typeof f === typeof g);
+    }
+    expect: {
+        (function o() {
+            var o;
+        })();
+        (function o() {
+        })();
+        console.log(typeof f === typeof g);
+    }
+    expect_stdout: "true"
+}
+
+issue_3355_2: {
+    mangle = {
+        ie8: true,
+    }
+    input: {
+        (function f() {
+            var f;
+        })();
+        (function g() {
+        })();
+        console.log(typeof f === typeof g);
+    }
+    expect: {
+        (function f() {
+            var f;
+        })();
+        (function g() {
+        })();
+        console.log(typeof f === typeof g);
+    }
+    expect_stdout: "true"
+}
+
+issue_3355_3: {
+    mangle = {
+        ie8: false,
+    }
+    input: {
+        !function(a) {
+            "aaaaaaaaaa";
+            a();
+            var b = function c() {
+                var c = 42;
+                console.log("FAIL");
+            };
+        }(function() {
+            console.log("PASS");
+        });
+    }
+    expect: {
+        !function(a) {
+            "aaaaaaaaaa";
+            a();
+            var o = function a() {
+                var a = 42;
+                console.log("FAIL");
+            };
+        }(function() {
+            console.log("PASS");
+        });
+    }
+    expect_stdout: "PASS"
+}
+
+issue_3355_4: {
+    mangle = {
+        ie8: true,
+    }
+    input: {
+        !function(a) {
+            "aaaaaaaaaa";
+            a();
+            var b = function c() {
+                var c = 42;
+                console.log("FAIL");
+            };
+        }(function() {
+            console.log("PASS");
+        });
+    }
+    expect: {
+        !function(a) {
+            "aaaaaaaaaa";
+            a();
+            var o = function n() {
+                var n = 42;
+                console.log("FAIL");
+            };
+        }(function() {
+            console.log("PASS");
+        });
+    }
+    expect_stdout: "PASS"
+}

test/compress/loops.js

@@ -646,3 +646,30 @@ issue_2904: {
     }
     expect_stdout: "1"
 }
+
+issue_3371: {
+    options = {
+        functions: true,
+        join_vars: true,
+        loops: true,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        (function() {
+            var a = function() {
+                console.log("PASS");
+            };
+            while (a());
+        })();
+    }
+    expect: {
+        (function() {
+            function a() {
+                console.log("PASS");
+            }
+            for (; a(); );
+        })();
+    }
+    expect_stdout: "PASS"
+}

test/compress/reduce_vars.js

@@ -281,8 +281,8 @@ unsafe_evaluate_escaped: {
         console.log(function(){ var o={p:3},a=[o]; console.log(a[0].p++); return o.p; }());
     }
     expect: {
-        console.log(function(){ var o={p:1}; console.log(o, o.p); return o.p; }());
-        console.log(function(){ var o={p:2}; console.log(o.p, o); return o.p; }());
+        console.log(function(){ var o={p:1}; console.log(o, 1); return o.p; }());
+        console.log(function(){ var o={p:2}; console.log(2, o); return o.p; }());
         console.log(function(){ var o={p:3},a=[o]; console.log(a[0].p++); return o.p; }());
     }
     expect_stdout: true
@@ -6737,3 +6737,21 @@ drop_side_effect_free: {
     }
     expect_stdout: "123"
 }
+
+issue_3377: {
+    options = {
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        console.log(function f() {
+            return f[0], (f = 42);
+        }());
+    }
+    expect: {
+        console.log(function f() {
+            return f[0], (f = 42);
+        }());
+    }
+    expect_stdout: "42"
+}

test/exports.js

@@ -1,7 +1,5 @@
-exports["base54"] = base54;
 exports["Compressor"] = Compressor;
 exports["defaults"] = defaults;
-exports["is_identifier"] = is_identifier;
 exports["JS_Parse_Error"] = JS_Parse_Error;
 exports["mangle_properties"] = mangle_properties;
 exports["minify"] = minify;
@@ -9,7 +7,6 @@ exports["OutputStream"] = OutputStream;
 exports["parse"] = parse;
 exports["push_uniq"] = push_uniq;
 exports["reserve_quoted_keys"] = reserve_quoted_keys;
-exports["SourceMap"] = SourceMap;
 exports["string_template"] = string_template;
 exports["tokenizer"] = tokenizer;
 exports["TreeTransformer"] = TreeTransformer;

test/jetstream.js

@@ -3,7 +3,7 @@
 
 "use strict";
 
-var site = "https://browserbench.org/JetStream";
+var site = "https://browserbench.org/JetStream1.1";
 if (typeof phantom == "undefined") {
     require("../tools/exit");
     var args = process.argv.slice(2);

test/sandbox.js

@@ -73,8 +73,10 @@ exports.run_code = function(code, reuse) {
         process.stdout.write = original_write;
         if (!reuse || code.indexOf(".prototype") >= 0) {
             context = null;
-        } else for (var key in context) {
-            delete context[key];
+        } else {
+            vm.runInContext(Object.keys(context).map(function(name) {
+                return "delete " + name;
+            }).join("\n"), context);
         }
     }
 };

tools/props.html

@@ -1,61 +1,540 @@
+<!doctype html>
 <html>
-  <head>
-  </head>
-  <body>
-    <script>(function(){
-      var props = {};
+<body>
+    <script>
+        !function() {
+            var names = [];
+            var scanned = [];
+            var to_scan = [];
 
-      function addObject(obj) {
-        if (obj == null) return;
-        try {
-          Object.getOwnPropertyNames(obj).forEach(add);
-        } catch(ex) {}
-        if (obj.prototype) {
-          Object.getOwnPropertyNames(obj.prototype).forEach(add);
-        }
-        if (typeof obj == "function") {
-          try {
-            Object.getOwnPropertyNames(new obj).forEach(add);
-          } catch(ex) {}
-        }
-      }
+            function scan(obj) {
+                if (obj && typeof obj == "object" && !~scanned.indexOf(obj)) {
+                    scanned.push(obj);
+                    to_scan.push(obj);
+                }
+            }
 
-      function add(name) {
-        props[name] = true;
-      }
+            scan(self);
+            [
+                "a",
+                "abbr",
+                "acronym",
+                "address",
+                "applet",
+                "area",
+                "article",
+                "aside",
+                "audio",
+                "b",
+                "base",
+                "basefont",
+                "bdi",
+                "bdo",
+                "bgsound",
+                "big",
+                "blink",
+                "blockquote",
+                "body",
+                "br",
+                "button",
+                "canvas",
+                "caption",
+                "center",
+                "checked",
+                "cite",
+                "code",
+                "col",
+                "colgroup",
+                "command",
+                "comment",
+                "compact",
+                "content",
+                "data",
+                "datalist",
+                "dd",
+                "declare",
+                "defer",
+                "del",
+                "details",
+                "dfn",
+                "dialog",
+                "dir",
+                "disabled",
+                "div",
+                "dl",
+                "dt",
+                "element",
+                "em",
+                "embed",
+                "fieldset",
+                "figcaption",
+                "figure",
+                "font",
+                "footer",
+                "form",
+                "frame",
+                "frameset",
+                "h1",
+                "h2",
+                "h3",
+                "h4",
+                "h5",
+                "h6",
+                "head",
+                "header",
+                "hgroup",
+                "hr",
+                "html",
+                "i",
+                "iframe",
+                "image",
+                "img",
+                "input",
+                "ins",
+                "isindex",
+                "ismap",
+                "kbd",
+                "keygen",
+                "label",
+                "legend",
+                "li",
+                "link",
+                "listing",
+                "main",
+                "map",
+                "mark",
+                "marquee",
+                "math",
+                "menu",
+                "menuitem",
+                "meta",
+                "meter",
+                "multicol",
+                "multiple",
+                "nav",
+                "nobr",
+                "noembed",
+                "noframes",
+                "nohref",
+                "noresize",
+                "noscript",
+                "noshade",
+                "nowrap",
+                "object",
+                "ol",
+                "optgroup",
+                "option",
+                "output",
+                "p",
+                "param",
+                "picture",
+                "plaintext",
+                "pre",
+                "progress",
+                "q",
+                "rb",
+                "readonly",
+                "rp",
+                "rt",
+                "rtc",
+                "ruby",
+                "s",
+                "samp",
+                "script",
+                "section",
+                "select",
+                "selected",
+                "shadow",
+                "small",
+                "source",
+                "spacer",
+                "span",
+                "strike",
+                "strong",
+                "style",
+                "sub",
+                "summary",
+                "sup",
+                "svg",
+                "table",
+                "tbody",
+                "td",
+                "template",
+                "textarea",
+                "tfoot",
+                "th",
+                "thead",
+                "time",
+                "title",
+                "tr",
+                "track",
+                "tt",
+                "u",
+                "ul",
+                "var",
+                "video",
+                "wbr",
+                "xmp",
+                "XXX",
+            ].forEach(function(tag) {
+                scan(document.createElement(tag));
+            });
+            [
+                "abort",
+                "absolutedeviceorientation",
+                "activate",
+                "active",
+                "addsourcebuffer",
+                "addstream",
+                "addtrack",
+                "afterprint",
+                "afterscriptexecute",
+                "afterupdate",
+                "animationcancel",
+                "animationend",
+                "animationiteration",
+                "animationstart",
+                "appinstalled",
+                "audioend",
+                "audioprocess",
+                "audiostart",
+                "autocomplete",
+                "autocompleteerror",
+                "auxclick",
+                "beforeactivate",
+                "beforecopy",
+                "beforecut",
+                "beforedeactivate",
+                "beforeeditfocus",
+                "beforeinstallprompt",
+                "beforepaste",
+                "beforeprint",
+                "beforescriptexecute",
+                "beforeunload",
+                "beforeupdate",
+                "blocked",
+                "blur",
+                "bounce",
+                "boundary",
+                "cached",
+                "cancel",
+                "candidatewindowhide",
+                "candidatewindowshow",
+                "candidatewindowupdate",
+                "canplay",
+                "canplaythrough",
+                "cellchange",
+                "change",
+                "chargingchange",
+                "chargingtimechange",
+                "checking",
+                "click",
+                "close",
+                "compassneedscalibration",
+                "complete",
+                "connect",
+                "connecting",
+                "connectionstatechange",
+                "contextmenu",
+                "controllerchange",
+                "controlselect",
+                "copy",
+                "cuechange",
+                "cut",
+                "dataavailable",
+                "datachannel",
+                "datasetchanged",
+                "datasetcomplete",
+                "dblclick",
+                "deactivate",
+                "devicechange",
+                "devicelight",
+                "devicemotion",
+                "deviceorientation",
+                "deviceorientationabsolute",
+                "deviceproximity",
+                "dischargingtimechange",
+                "disconnect",
+                "display",
+                "downloading",
+                "drag",
+                "dragend",
+                "dragenter",
+                "dragexit",
+                "dragleave",
+                "dragover",
+                "dragstart",
+                "drop",
+                "durationchange",
+                "emptied",
+                "encrypted",
+                "end",
+                "ended",
+                "enter",
+                "enterpictureinpicture",
+                "error",
+                "errorupdate",
+                "exit",
+                "filterchange",
+                "finish",
+                "focus",
+                "focusin",
+                "focusout",
+                "freeze",
+                "fullscreenchange",
+                "fullscreenerror",
+                "gesturechange",
+                "gestureend",
+                "gesturestart",
+                "gotpointercapture",
+                "hashchange",
+                "help",
+                "icecandidate",
+                "iceconnectionstatechange",
+                "icegatheringstatechange",
+                "inactive",
+                "input",
+                "invalid",
+                "keydown",
+                "keypress",
+                "keyup",
+                "languagechange",
+                "layoutcomplete",
+                "leavepictureinpicture",
+                "levelchange",
+                "load",
+                "loadeddata",
+                "loadedmetadata",
+                "loadend",
+                "loading",
+                "loadingdone",
+                "loadingerror",
+                "loadstart",
+                "losecapture",
+                "lostpointercapture",
+                "mark",
+                "message",
+                "messageerror",
+                "mousedown",
+                "mouseenter",
+                "mouseleave",
+                "mousemove",
+                "mouseout",
+                "mouseover",
+                "mouseup",
+                "mousewheel",
+                "move",
+                "moveend",
+                "movestart",
+                "mozfullscreenchange",
+                "mozfullscreenerror",
+                "mozorientationchange",
+                "mozpointerlockchange",
+                "mozpointerlockerror",
+                "mscontentzoom",
+                "msfullscreenchange",
+                "msfullscreenerror",
+                "msgesturechange",
+                "msgesturedoubletap",
+                "msgestureend",
+                "msgesturehold",
+                "msgesturestart",
+                "msgesturetap",
+                "msgotpointercapture",
+                "msinertiastart",
+                "mslostpointercapture",
+                "msmanipulationstatechanged",
+                "msneedkey",
+                "msorientationchange",
+                "mspointercancel",
+                "mspointerdown",
+                "mspointerenter",
+                "mspointerhover",
+                "mspointerleave",
+                "mspointermove",
+                "mspointerout",
+                "mspointerover",
+                "mspointerup",
+                "mssitemodejumplistitemremoved",
+                "msthumbnailclick",
+                "negotiationneeded",
+                "nomatch",
+                "noupdate",
+                "obsolete",
+                "offline",
+                "online",
+                "open",
+                "orientationchange",
+                "pagechange",
+                "pagehide",
+                "pageshow",
+                "paste",
+                "pause",
+                "play",
+                "playing",
+                "pluginstreamstart",
+                "pointercancel",
+                "pointerdown",
+                "pointerenter",
+                "pointerleave",
+                "pointerlockchange",
+                "pointerlockerror",
+                "pointermove",
+                "pointerout",
+                "pointerover",
+                "pointerup",
+                "popstate",
+                "progress",
+                "propertychange",
+                "ratechange",
+                "reading",
+                "readystatechange",
+                "rejectionhandled",
+                "removesourcebuffer",
+                "removestream",
+                "removetrack",
+                "reset",
+                "resize",
+                "resizeend",
+                "resizestart",
+                "resourcetimingbufferfull",
+                "result",
+                "resume",
+                "rowenter",
+                "rowexit",
+                "rowsdelete",
+                "rowsinserted",
+                "scroll",
+                "search",
+                "seeked",
+                "seeking",
+                "select",
+                "selectionchange",
+                "selectstart",
+                "show",
+                "signalingstatechange",
+                "soundend",
+                "soundstart",
+                "sourceclose",
+                "sourceclosed",
+                "sourceended",
+                "sourceopen",
+                "speechend",
+                "speechstart",
+                "stalled",
+                "start",
+                "statechange",
+                "stop",
+                "storage",
+                "storagecommit",
+                "submit",
+                "success",
+                "suspend",
+                "textinput",
+                "timeout",
+                "timeupdate",
+                "toggle",
+                "touchcancel",
+                "touchend",
+                "touchmove",
+                "touchstart",
+                "track",
+                "transitioncancel",
+                "transitionend",
+                "transitionrun",
+                "transitionstart",
+                "unhandledrejection",
+                "unload",
+                "updateready",
+                "upgradeneeded",
+                "userproximity",
+                "versionchange",
+                "visibilitychange",
+                "voiceschanged",
+                "volumechange",
+                "vrdisplayactivate",
+                "vrdisplayconnect",
+                "vrdisplaydeactivate",
+                "vrdisplaydisconnect",
+                "vrdisplaypresentchange",
+                "waiting",
+                "waitingforkey",
+                "warning",
+                "webkitanimationend",
+                "webkitanimationiteration",
+                "webkitanimationstart",
+                "webkitcurrentplaybacktargetiswirelesschanged",
+                "webkitfullscreenchange",
+                "webkitfullscreenerror",
+                "webkitkeyadded",
+                "webkitkeyerror",
+                "webkitkeymessage",
+                "webkitneedkey",
+                "webkitorientationchange",
+                "webkitplaybacktargetavailabilitychanged",
+                "webkitpointerlockchange",
+                "webkitpointerlockerror",
+                "webkitresourcetimingbufferfull",
+                "webkittransitionend",
+                "wheel",
+                "zoom",
+            ].forEach(function(type) {
+                [
+                    "beforeunloadevent",
+                    "compositionevent",
+                    "customevent",
+                    "devicemotionevent",
+                    "deviceorientationevent",
+                    "dragevent",
+                    "event",
+                    "events",
+                    "focusevent",
+                    "hashchangeevent",
+                    "htmlevents",
+                    "keyboardevent",
+                    "messageevent",
+                    "mouseevent",
+                    "mouseevents",
+                    "storageevent",
+                    "svgevents",
+                    "textevent",
+                    "touchevent",
+                    "uievent",
+                    "uievents",
+                ].forEach(function(interface) {
+                    try {
+                        var event = document.createEvent(interface);
+                        event.initEvent(type, true, true);
+                        scan(event);
+                    } catch (e) {}
+                });
+            });
 
-      Object.getOwnPropertyNames(window).forEach(function(thing){
-        addObject(window[thing]);
-      });
-
-      try {
-        addObject(new Event("click"));
-        addObject(new Event("contextmenu"));
-        addObject(new Event("mouseup"));
-        addObject(new Event("mousedown"));
-        addObject(new Event("keydown"));
-        addObject(new Event("keypress"));
-        addObject(new Event("keyup"));
-      } catch(ex) {}
-
-      var ta = document.createElement("textarea");
-      ta.style.width = "100%";
-      ta.style.height = "20em";
-      ta.style.boxSizing = "border-box";
-      <!-- ta.value = Object.keys(props).sort(cmp).map(function(name){ -->
-      <!--   return JSON.stringify(name); -->
-      <!-- }).join(",\n"); -->
-      ta.value = JSON.stringify({
-        vars: [],
-        props: Object.keys(props).sort(cmp)
-      }, null, 2);
-      document.body.appendChild(ta);
-
-      function cmp(a, b) {
-        a = a.toLowerCase();
-        b = b.toLowerCase();
-        return a < b ? -1 : a > b ? 1 : 0;
-      }
-    })();</script>
-  </body>
+            var obj;
+            while (obj = to_scan.shift()) {
+                var proto = obj;
+                do {
+                    Object.getOwnPropertyNames(proto).forEach(function(name) {
+                        var visited = ~names.indexOf(name);
+                        if (!visited) names.push(name);
+                        try {
+                            scan(obj[name]);
+                            if (visited) return;
+                            if (/^create/.test(name)) {
+                                scan(obj[name]());
+                            }
+                            if (/^[A-Z]/.test(name)) {
+                                scan(new obj[name]());
+                            }
+                        } catch (e) {}
+                    });
+                } while (proto = Object.getPrototypeOf(proto));
+            }
+            names.sort();
+            document.write('<pre>[\n    "');
+            document.write(names.join('",\n    "'));
+            document.write('"\n]</pre>');
+        }();
+    </script>
+</body>
 </html>