v3.5.5

fixes #3366

README.md

@@ -605,6 +605,8 @@ If you're using the `X-SourceMap` header instead, you can just omit `sourceMap.u
 - `arguments` (default: `true`) -- replace `arguments[index]` with function
   parameter name whenever possible.
 
+- `assignments` (default: `true`) -- apply optimizations to assignment expressions.
+
 - `booleans` (default: `true`) -- various optimizations for boolean context,
   for example `!!a ? b : c → a ? b : c`
 
@@ -634,6 +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/compress.js

@@ -49,6 +49,7 @@ function Compressor(options, false_by_default) {
     TreeTransformer.call(this, this.before, this.after);
     this.options = defaults(options, {
         arguments       : !false_by_default,
+        assignments     : !false_by_default,
         booleans        : !false_by_default,
         collapse_vars   : !false_by_default,
         comparisons     : !false_by_default,
@@ -59,6 +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,
@@ -149,7 +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;
@@ -537,13 +539,11 @@ merge(Compressor.prototype, {
             var d = sym.definition();
             var safe = safe_to_assign(tw, d, sym.scope, node.right);
             d.assignments++;
-            if (!safe) return;
             var fixed = d.fixed;
             if (!fixed && node.operator != "=") return;
             var eq = node.operator == "=";
             var value = eq ? node.right : node;
             if (is_modified(compressor, tw, node, value, 0)) return;
-            d.references.push(sym);
             if (!eq) d.chained = true;
             d.fixed = eq ? function() {
                 return node.right;
@@ -554,6 +554,8 @@ merge(Compressor.prototype, {
                     right: node.right
                 });
             };
+            if (!safe) return;
+            d.references.push(sym);
             mark(tw, d, false);
             node.right.walk(tw);
             mark(tw, d, true);
@@ -783,10 +785,8 @@ merge(Compressor.prototype, {
             var d = exp.definition();
             var safe = safe_to_assign(tw, d, exp.scope, true);
             d.assignments++;
-            if (!safe) return;
             var fixed = d.fixed;
             if (!fixed) return;
-            d.references.push(exp);
             d.chained = true;
             d.fixed = function() {
                 return make_node(AST_Binary, node, {
@@ -800,6 +800,8 @@ merge(Compressor.prototype, {
                     })
                 });
             };
+            if (!safe) return;
+            d.references.push(exp);
             mark(tw, d, true);
             return true;
         });
@@ -1100,10 +1102,10 @@ merge(Compressor.prototype, {
                     stop_if_hit = parent;
                 }
                 // Replace variable with assignment when found
-                var hit_lhs, hit_rhs;
+                var hit_rhs;
                 if (can_replace
                     && !(node instanceof AST_SymbolDeclaration)
-                    && (scan_lhs && (hit_lhs = lhs.equivalent_to(node))
+                    && (scan_lhs && lhs.equivalent_to(node)
                         || scan_rhs && (hit_rhs = scan_rhs(node, this)))) {
                     if (stop_if_hit && (hit_rhs || !lhs_local || !replace_all)) {
                         abort = true;
@@ -1193,10 +1195,9 @@ merge(Compressor.prototype, {
                     var stop_after = null;
                     var stop_if_hit = null;
                     var lhs = get_lhs(candidate);
-                    var rhs = get_rhs(candidate);
                     var side_effects = lhs && lhs.has_side_effects(compressor);
                     var scan_lhs = lhs && !side_effects && !is_lhs_read_only(lhs);
-                    var scan_rhs = rhs && foldable(rhs);
+                    var scan_rhs = foldable(get_rhs(candidate));
                     if (!scan_lhs && !scan_rhs) continue;
                     // Locate symbols which may execute code outside of scanning range
                     var lvalues = get_lvalues(candidate);
@@ -1241,7 +1242,7 @@ 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) {
@@ -1361,6 +1362,7 @@ merge(Compressor.prototype, {
                 hit_stack.push(expr);
                 if (expr instanceof AST_Assign) {
                     candidates.push(hit_stack.slice());
+                    extract_candidates(expr.left);
                     extract_candidates(expr.right);
                 } else if (expr instanceof AST_Binary) {
                     extract_candidates(expr.left);
@@ -1376,6 +1378,8 @@ merge(Compressor.prototype, {
                     extract_candidates(expr.alternative);
                 } else if (expr instanceof AST_Definitions) {
                     expr.definitions.forEach(extract_candidates);
+                } else if (expr instanceof AST_Dot) {
+                    extract_candidates(expr.expression);
                 } else if (expr instanceof AST_DWLoop) {
                     extract_candidates(expr.condition);
                     if (!(expr.body instanceof AST_Block)) {
@@ -1407,6 +1411,9 @@ merge(Compressor.prototype, {
                     expr.expressions.forEach(extract_candidates);
                 } else if (expr instanceof AST_SimpleStatement) {
                     extract_candidates(expr.body);
+                } else if (expr instanceof AST_Sub) {
+                    extract_candidates(expr.expression);
+                    extract_candidates(expr.property);
                 } else if (expr instanceof AST_Switch) {
                     extract_candidates(expr.expression);
                     expr.body.forEach(extract_candidates);
@@ -1465,6 +1472,7 @@ merge(Compressor.prototype, {
                     return node;
                 }
                 if (parent instanceof AST_IterationStatement) return node;
+                if (parent instanceof AST_PropAccess) return node;
                 if (parent instanceof AST_Sequence) {
                     return find_stop(parent, level + 1, parent.tail_node() !== node);
                 }
@@ -1523,6 +1531,7 @@ merge(Compressor.prototype, {
             }
 
             function foldable(expr) {
+                if (!expr) return false;
                 if (expr instanceof AST_SymbolRef) {
                     var value = expr.evaluate(compressor);
                     if (value === expr) return rhs_exact_match;
@@ -1544,10 +1553,10 @@ merge(Compressor.prototype, {
                     }
                 }));
                 return !circular && rhs_exact_match;
-            }
 
-            function rhs_exact_match(node) {
-                return rhs.equivalent_to(node);
+                function rhs_exact_match(node) {
+                    return expr.equivalent_to(node);
+                }
             }
 
             function rhs_fuzzy_match(value, fallback) {
@@ -1879,7 +1888,7 @@ 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;
@@ -1970,7 +1979,7 @@ 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);
@@ -2110,7 +2119,7 @@ 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) {
@@ -2238,7 +2247,11 @@ merge(Compressor.prototype, {
         });
         def(AST_SymbolRef, function() {
             var fixed = this.fixed_value();
-            return fixed && fixed.is_truthy();
+            if (!fixed) return false;
+            this.is_truthy = return_false;
+            var result = fixed.is_truthy();
+            delete this.is_truthy;
+            return result;
         });
     })(function(node, func) {
         node.DEFMETHOD("is_truthy", func);
@@ -2251,45 +2264,38 @@ merge(Compressor.prototype, {
             return !compressor.option("pure_getters")
                 || this._dot_throw(compressor);
         });
-
         function is_strict(compressor) {
             return /strict/.test(compressor.option("pure_getters"));
         }
-
         def(AST_Node, is_strict);
-        def(AST_Null, return_true);
-        def(AST_Undefined, return_true);
-        def(AST_Constant, return_false);
         def(AST_Array, return_false);
-        def(AST_Object, function(compressor) {
-            if (!is_strict(compressor)) return false;
-            for (var i = this.properties.length; --i >=0;)
-                if (this.properties[i].value instanceof AST_Accessor) return true;
-            return false;
-        });
-        def(AST_Lambda, return_false);
-        def(AST_UnaryPostfix, return_false);
-        def(AST_UnaryPrefix, function() {
-            return this.operator == "void";
-        });
-        def(AST_Binary, function(compressor) {
-            return (this.operator == "&&" || this.operator == "||")
-                && (this.left._dot_throw(compressor) || this.right._dot_throw(compressor));
-        })
         def(AST_Assign, function(compressor) {
             return this.operator == "="
                 && this.right._dot_throw(compressor);
         })
+        def(AST_Binary, function(compressor) {
+            return (this.operator == "&&" || this.operator == "||")
+                && (this.left._dot_throw(compressor) || this.right._dot_throw(compressor));
+        })
         def(AST_Conditional, function(compressor) {
             return this.consequent._dot_throw(compressor)
                 || this.alternative._dot_throw(compressor);
         })
+        def(AST_Constant, return_false);
         def(AST_Dot, function(compressor) {
             if (!is_strict(compressor)) return false;
             var exp = this.expression;
             if (exp instanceof AST_SymbolRef) exp = exp.fixed_value();
             return !(exp instanceof AST_Lambda && this.property == "prototype");
         });
+        def(AST_Lambda, return_false);
+        def(AST_Null, return_true);
+        def(AST_Object, function(compressor) {
+            if (!is_strict(compressor)) return false;
+            for (var i = this.properties.length; --i >=0;)
+                if (this.properties[i].value instanceof AST_Accessor) return true;
+            return false;
+        });
         def(AST_Sequence, function(compressor) {
             return this.tail_node()._dot_throw(compressor);
         });
@@ -2299,8 +2305,17 @@ merge(Compressor.prototype, {
             if (is_undeclared_ref(this) && this.is_declared(compressor)) return false;
             if (this.is_immutable()) return false;
             var fixed = this.fixed_value();
-            return !fixed || fixed._dot_throw(compressor);
+            if (!fixed) return true;
+            this._dot_throw = return_true;
+            var result = fixed._dot_throw(compressor);
+            delete this._dot_throw;
+            return result;
         });
+        def(AST_UnaryPrefix, function() {
+            return this.operator == "void";
+        });
+        def(AST_UnaryPostfix, return_false);
+        def(AST_Undefined, return_true);
     })(function(node, func) {
         node.DEFMETHOD("_dot_throw", func);
     });
@@ -2334,6 +2349,14 @@ merge(Compressor.prototype, {
         def(AST_Sequence, function(compressor) {
             return this.tail_node().is_boolean(compressor);
         });
+        def(AST_SymbolRef, function(compressor) {
+            var fixed = this.fixed_value();
+            if (!fixed) return false;
+            this.is_boolean = return_false;
+            var result = fixed.is_boolean(compressor);
+            delete this.is_boolean;
+            return result;
+        });
         var unary = makePredicate("! delete");
         def(AST_UnaryPrefix, function() {
             return unary[this.operator];
@@ -2415,6 +2438,14 @@ merge(Compressor.prototype, {
         def(AST_Sequence, function(compressor) {
             return this.tail_node().is_number(compressor);
         });
+        def(AST_SymbolRef, function(compressor) {
+            var fixed = this.fixed_value();
+            if (!fixed) return false;
+            this.is_number = return_false;
+            var result = fixed.is_number(compressor);
+            delete this.is_number;
+            return result;
+        });
         var unary = makePredicate("+ - ~ ++ --");
         def(AST_Unary, function() {
             return unary[this.operator];
@@ -2426,22 +2457,30 @@ merge(Compressor.prototype, {
     // methods to determine if an expression has a string result type
     (function(def) {
         def(AST_Node, return_false);
-        def(AST_String, return_true);
-        def(AST_UnaryPrefix, function() {
-            return this.operator == "typeof";
+        def(AST_Assign, function(compressor) {
+            return (this.operator == "=" || this.operator == "+=") && this.right.is_string(compressor);
         });
         def(AST_Binary, function(compressor) {
             return this.operator == "+" &&
                 (this.left.is_string(compressor) || this.right.is_string(compressor));
         });
-        def(AST_Assign, function(compressor) {
-            return (this.operator == "=" || this.operator == "+=") && this.right.is_string(compressor);
+        def(AST_Conditional, function(compressor) {
+            return this.consequent.is_string(compressor) && this.alternative.is_string(compressor);
         });
         def(AST_Sequence, function(compressor) {
             return this.tail_node().is_string(compressor);
         });
-        def(AST_Conditional, function(compressor) {
-            return this.consequent.is_string(compressor) && this.alternative.is_string(compressor);
+        def(AST_String, return_true);
+        def(AST_SymbolRef, function(compressor) {
+            var fixed = this.fixed_value();
+            if (!fixed) return false;
+            this.is_string = return_false;
+            var result = fixed.is_string(compressor);
+            delete this.is_string;
+            return result;
+        });
+        def(AST_UnaryPrefix, function() {
+            return this.operator == "typeof";
         });
     })(function(node, func) {
         node.DEFMETHOD("is_string", func);
@@ -2681,7 +2720,7 @@ 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;
@@ -2694,7 +2733,7 @@ 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) {
@@ -2889,7 +2928,7 @@ 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;
@@ -3240,6 +3279,12 @@ merge(Compressor.prototype, {
             return true;
         }
         def(AST_Node, return_false);
+        def(AST_Array, function() {
+            return all(this.elements);
+        });
+        def(AST_Binary, function() {
+            return this.left.is_constant_expression() && this.right.is_constant_expression();
+        });
         def(AST_Constant, return_true);
         def(AST_Lambda, function(scope) {
             var self = this;
@@ -3268,21 +3313,15 @@ merge(Compressor.prototype, {
             }));
             return result;
         });
-        def(AST_Unary, function() {
-            return this.expression.is_constant_expression();
-        });
-        def(AST_Binary, function() {
-            return this.left.is_constant_expression() && this.right.is_constant_expression();
-        });
-        def(AST_Array, function() {
-            return all(this.elements);
-        });
         def(AST_Object, function() {
             return all(this.properties);
         });
         def(AST_ObjectProperty, function() {
             return this.value.is_constant_expression();
         });
+        def(AST_Unary, function() {
+            return this.expression.is_constant_expression();
+        });
     })(function(node, func) {
         node.DEFMETHOD("is_constant_expression", func);
     });
@@ -3425,9 +3464,7 @@ 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;
@@ -3534,29 +3571,40 @@ 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
+                            && !def.value.name
+                            && !def.value.variables.get(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);
+                            def.name.scope.resolve().def_function(defun.name);
+                            body.push(defun);
+                        } else {
                             if (side_effects.length > 0) {
                                 if (tail.length > 0) {
                                     side_effects.push(def.value);
@@ -3569,8 +3617,6 @@ 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);
@@ -3992,17 +4038,17 @@ merge(Compressor.prototype, {
             return this;
         });
         def(AST_Binary, function(compressor, first_in_statement) {
-            var right = this.right.drop_side_effect_free(compressor);
+            var right = this.right.drop_side_effect_free(compressor, first_in_statement);
             if (!right) return this.left.drop_side_effect_free(compressor, first_in_statement);
             if (lazy_op[this.operator]) {
                 if (right === this.right) return this;
                 var node = this.clone();
-                node.right = right;
+                node.right = right.drop_side_effect_free(compressor);
                 return node;
             } else {
                 var left = this.left.drop_side_effect_free(compressor, first_in_statement);
-                if (!left) return this.right.drop_side_effect_free(compressor, first_in_statement);
-                return make_sequence(this, [ left, right ]);
+                if (!left) return right;
+                return make_sequence(this, [ left, right.drop_side_effect_free(compressor) ]);
             }
         });
         def(AST_Call, function(compressor, first_in_statement) {
@@ -4062,19 +4108,6 @@ merge(Compressor.prototype, {
         def(AST_Function, function(compressor) {
             return this.name && compressor.option("ie8") ? this : null;
         });
-        def(AST_Unary, function(compressor, first_in_statement) {
-            if (unary_side_effects[this.operator]) {
-                this.write_only = !this.expression.has_side_effects(compressor);
-                return this;
-            }
-            if (this.operator == "typeof" && this.expression instanceof AST_SymbolRef) return null;
-            var expression = this.expression.drop_side_effect_free(compressor, first_in_statement);
-            if (first_in_statement && expression && is_iife_call(expression)) {
-                if (expression === this.expression && this.operator == "!") return this;
-                return expression.negate(compressor, first_in_statement);
-            }
-            return expression;
-        });
         def(AST_Object, function(compressor, first_in_statement) {
             var values = trim(this.properties, compressor, first_in_statement);
             return values && make_sequence(this, values);
@@ -4082,12 +4115,10 @@ merge(Compressor.prototype, {
         def(AST_ObjectProperty, function(compressor, first_in_statement) {
             return this.value.drop_side_effect_free(compressor, first_in_statement);
         });
-        def(AST_Sequence, function(compressor) {
-            var last = this.tail_node();
-            var expr = last.drop_side_effect_free(compressor);
-            if (expr === last) return this;
-            var expressions = this.expressions.slice(0, -1);
-            if (expr) expressions.push(expr);
+        def(AST_Sequence, function(compressor, first_in_statement) {
+            var expressions = trim(this.expressions, compressor, first_in_statement);
+            if (expressions === this.expressions) return this;
+            if (!expressions) return null;
             return make_sequence(this, expressions);
         });
         def(AST_Sub, function(compressor, first_in_statement) {
@@ -4099,9 +4130,27 @@ merge(Compressor.prototype, {
             return make_sequence(this, [ expression, property ]);
         });
         def(AST_SymbolRef, function(compressor) {
-            return this.is_declared(compressor) ? null : this;
+            if (!this.is_declared(compressor)) return this;
+            this.definition().replaced++;
+            return null;
         });
         def(AST_This, return_null);
+        def(AST_Unary, function(compressor, first_in_statement) {
+            if (unary_side_effects[this.operator]) {
+                this.write_only = !this.expression.has_side_effects(compressor);
+                return this;
+            }
+            if (this.operator == "typeof" && this.expression instanceof AST_SymbolRef) {
+                this.expression.definition().replaced++;
+                return null;
+            }
+            var expression = this.expression.drop_side_effect_free(compressor, first_in_statement);
+            if (first_in_statement && expression && is_iife_call(expression)) {
+                if (expression === this.expression && this.operator == "!") return this;
+                return expression.negate(compressor, first_in_statement);
+            }
+            return expression;
+        });
     })(function(node, func) {
         node.DEFMETHOD("drop_side_effect_free", func);
     });
@@ -4596,9 +4645,7 @@ merge(Compressor.prototype, {
     });
 
     OPT(AST_Definitions, function(self, compressor) {
-        if (self.definitions.length == 0)
-            return make_node(AST_EmptyStatement, self);
-        return self;
+        return self.definitions.length ? self : make_node(AST_EmptyStatement, self);
     });
 
     AST_Call.DEFMETHOD("lift_sequences", function(compressor) {
@@ -4630,7 +4677,7 @@ 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);
@@ -4652,12 +4699,30 @@ merge(Compressor.prototype, {
         if (compressor.option("unsafe")) {
             if (is_undeclared_ref(exp)) switch (exp.name) {
               case "Array":
-                if (self.args.length != 1) {
-                    return make_node(AST_Array, self, {
-                        elements: self.args
-                    }).optimize(compressor);
+                if (self.args.length == 1) {
+                    var first = self.args[0];
+                    if (first instanceof AST_Number) try {
+                        var length = first.getValue();
+                        if (length > 6) break;
+                        var elements = Array(length);
+                        for (var i = 0; i < length; i++) elements[i] = make_node(AST_Hole, self);
+                        return make_node(AST_Array, self, {
+                            elements: elements
+                        });
+                    } catch (ex) {
+                        compressor.warn("Invalid array length: {length} [{file}:{line},{col}]", {
+                            length: length,
+                            file: self.start.file,
+                            line: self.start.line,
+                            col: self.start.col
+                        });
+                        break;
+                    }
+                    if (!first.is_boolean(compressor) && !first.is_string(compressor)) break;
                 }
-                break;
+                return make_node(AST_Array, self, {
+                    elements: self.args
+                });
               case "Object":
                 if (self.args.length == 0) {
                     return make_node(AST_Object, self, {
@@ -4990,7 +5055,7 @@ merge(Compressor.prototype, {
         }
 
         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
@@ -5005,8 +5070,7 @@ merge(Compressor.prototype, {
         }
 
         function can_inject_vars(catches, safe_to_inject) {
-            var len = fn.body.length;
-            for (var i = 0; i < len; i++) {
+            for (var i = 0; i < fn.body.length; i++) {
                 var stat = fn.body[i];
                 if (!(stat instanceof AST_Var)) continue;
                 if (!safe_to_inject) return false;
@@ -5035,7 +5099,8 @@ merge(Compressor.prototype, {
                     if (scope.fixed_value() instanceof AST_Scope) return false;
                 }
             } while (!(scope instanceof AST_Scope));
-            var safe_to_inject = !(scope instanceof AST_Toplevel) || compressor.toplevel.vars;
+            var safe_to_inject = (!(scope instanceof AST_Toplevel) || compressor.toplevel.vars)
+                && (exp !== fn || fn.parent_scope === compressor.find_parent(AST_Scope));
             var inline = compressor.option("inline");
             if (!can_inject_vars(catches, inline >= 3 && safe_to_inject)) return false;
             if (!can_inject_args(catches, inline >= 2 && safe_to_inject)) return false;
@@ -5085,10 +5150,10 @@ 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();
@@ -5844,6 +5909,7 @@ merge(Compressor.prototype, {
                     value = fixed.optimize(compressor);
                     if (value === fixed) value = fixed.clone(true);
                 }
+                def.replaced++;
                 return value;
             }
             if (fixed && def.should_replace === undefined) {
@@ -5886,7 +5952,9 @@ merge(Compressor.prototype, {
                 }
             }
             if (def.should_replace) {
-                return def.should_replace();
+                var value = def.should_replace();
+                def.replaced++;
+                return value;
             }
         }
         return self;
@@ -6010,6 +6078,7 @@ merge(Compressor.prototype, {
                 || parent instanceof AST_Sequence && parent.tail_node() === node);
         }
         self = self.lift_sequences(compressor);
+        if (!compressor.option("assignments")) return self;
         if (self.operator == "=" && self.left instanceof AST_SymbolRef && self.right instanceof AST_Binary) {
             // x = expr1 OP expr2
             if (self.right.left instanceof AST_SymbolRef
@@ -6028,6 +6097,16 @@ merge(Compressor.prototype, {
                 self.right = self.right.left;
             }
         }
+        if ((self.operator == "+=" || self.operator == "-=")
+            && self.left.is_number(compressor)
+            && self.right instanceof AST_Number
+            && self.right.getValue() === 1) {
+            var op = self.operator.slice(0, -1);
+            return make_node(AST_UnaryPrefix, self, {
+                operator: op + op,
+                expression: self.left
+            });
+        }
         return self;
 
         function in_try(level, node) {

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": "3.4.10",
+  "version": "3.5.5",
   "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/arrays.js

@@ -239,3 +239,113 @@ index_length: {
     }
     expect_stdout: "1 2"
 }
+
+constructor_bad: {
+    options = {
+        unsafe: true
+    }
+    input: {
+        try {
+            Array(NaN);
+            console.log("FAIL1");
+        } catch (ex) {
+            try {
+                new Array(NaN);
+                console.log("FAIL2");
+            } catch (ex) {
+                console.log("PASS");
+            }
+        }
+        try {
+            Array(3.14);
+            console.log("FAIL1");
+        } catch (ex) {
+            try {
+                new Array(3.14);
+                console.log("FAIL2");
+            } catch (ex) {
+                console.log("PASS");
+            }
+        }
+    }
+    expect: {
+        try {
+            Array(NaN);
+            console.log("FAIL1");
+        } catch (ex) {
+            try {
+                Array(NaN);
+                console.log("FAIL2");
+            } catch (ex) {
+                console.log("PASS");
+            }
+        }
+        try {
+            Array(3.14);
+            console.log("FAIL1");
+        } catch (ex) {
+            try {
+                Array(3.14);
+                console.log("FAIL2");
+            } catch (ex) {
+                console.log("PASS");
+            }
+        }
+    }
+    expect_stdout: [
+        "PASS",
+        "PASS",
+    ]
+    expect_warnings: [
+        "WARN: Invalid array length: 3.14 [test/compress/arrays.js:13,12]",
+        "WARN: Invalid array length: 3.14 [test/compress/arrays.js:17,16]",
+    ]
+}
+
+constructor_good: {
+    options = {
+        unsafe: true
+    }
+    input: {
+        console.log(Array());
+        console.log(Array(0));
+        console.log(Array(1));
+        console.log(Array(6));
+        console.log(Array(7));
+        console.log(Array(1, 2));
+        console.log(Array(false));
+        console.log(Array("foo"));
+        console.log(Array(Array));
+        console.log(new Array());
+        console.log(new Array(0));
+        console.log(new Array(1));
+        console.log(new Array(6));
+        console.log(new Array(7));
+        console.log(new Array(1, 2));
+        console.log(new Array(false));
+        console.log(new Array("foo"));
+        console.log(new Array(Array));
+    }
+    expect: {
+        console.log([]);
+        console.log([]);
+        console.log([,]);
+        console.log([,,,,,,]);
+        console.log(Array(7));
+        console.log([ 1, 2 ]);
+        console.log([ false ]);
+        console.log([ "foo" ]);
+        console.log(Array(Array));
+        console.log([]);
+        console.log([]);
+        console.log([,]);
+        console.log([,,,,,,]);
+        console.log(Array(7));
+        console.log([ 1, 2 ]);
+        console.log([ false ]);
+        console.log([ "foo" ]);
+        console.log(Array(Array));
+    }
+    expect_stdout: true
+    expect_warnings: []
+}

test/compress/asm.js

@@ -1,5 +1,6 @@
 asm_mixed: {
     options = {
+        assignments: true,
         booleans: true,
         comparisons: true,
         conditionals: true,

test/compress/assignment.js

@@ -1,5 +1,6 @@
 op_equals_left_local_var: {
     options = {
+        assignments: true,
         evaluate: true,
     }
     input: {
@@ -60,6 +61,7 @@ op_equals_left_local_var: {
 
 op_equals_right_local_var: {
     options = {
+        assignments: true,
         evaluate: true,
     }
     input: {
@@ -123,6 +125,7 @@ op_equals_right_local_var: {
 }
 op_equals_left_global_var: {
     options = {
+        assignments: true,
         evaluate: true,
     }
     input: {
@@ -179,6 +182,7 @@ op_equals_left_global_var: {
 
 op_equals_right_global_var: {
     options = {
+        assignments: true,
         evaluate: true,
     }
     input: {
@@ -236,3 +240,52 @@ op_equals_right_global_var: {
         x = g() &   x;
     }
 }
+
+increment_decrement_1: {
+    options = {
+        assignments: true,
+        reduce_vars: true,
+    }
+    input: {
+        console.log(function(a) {
+            a += 1;
+            a -= 1;
+            return a;
+        }(42));
+    }
+    expect: {
+        console.log(function(a){
+            ++a;
+            --a;
+            return a;
+        }(42));
+    }
+    expect_stdout: "42"
+}
+
+increment_decrement_2: {
+    options = {
+        assignments: true,
+        passes: 2,
+        reduce_vars: true,
+    }
+    input: {
+        console.log(function(a) {
+            a = a + 1;
+            a = a - 1;
+            a += 1;
+            a -= 1;
+            return a;
+        }(42));
+    }
+    expect: {
+        console.log(function(a){
+            ++a;
+            --a;
+            ++a;
+            --a;
+            return a;
+        }(42));
+    }
+    expect_stdout: "42"
+}

test/compress/collapse_vars.js

@@ -944,7 +944,7 @@ collapse_vars_misc1: {
         function f5(x) { var z = foo(); return (5 - window.x) / z }
         function f6() { return window.a * window.z && zap() }
         function f7() { var b = window.a * window.z; return b + b }
-        function f8() { var b = window.a * window.z; return b + (b + 5) }
+        function f8() { var b = window.a * window.z; return b + (5 + b) }
         function f9() { var b = window.a * window.z; return bar() || b }
         function f10(x) { var a = 5; return a += 3; }
         function f11(x) { var a = 5; return a += 2; }
@@ -3895,11 +3895,11 @@ issue_2436_10: {
             o = { b: 3 };
             return n;
         }
-        console.log((c = o, [
-            c.a,
+        console.log([
+            (c = o).a,
             f(c.b),
             c.b,
-        ]).join(" "));
+        ].join(" "));
         var c;
     }
     expect_stdout: "1 2 2"
@@ -6121,3 +6121,39 @@ issue_3327: {
     }
     expect_stdout: "PASS 42"
 }
+
+assign_left: {
+    options = {
+        collapse_vars: true,
+    }
+    input: {
+        console.log(function(a, b) {
+            (b = a, b.p).q = "PASS";
+            return a.p.q;
+        }({p: {}}));
+    }
+    expect: {
+        console.log(function(a, b) {
+            (b = a).p.q = "PASS";
+            return a.p.q;
+        }({p: {}}));
+    }
+    expect_stdout: "PASS"
+}
+
+sub_property: {
+    options = {
+        collapse_vars: true,
+    }
+    input: {
+        console.log(function(a, b) {
+            return a[(b = a, b.length - 1)];
+        }([ "FAIL", "PASS" ]));
+    }
+    expect: {
+        console.log(function(a, b) {
+            return a[(b = a).length - 1];
+        }([ "FAIL", "PASS" ]));
+    }
+    expect_stdout: "PASS"
+}

test/compress/comparisons.js

@@ -323,3 +323,25 @@ is_number_unsafe: {
     }
     expect_stdout: "true"
 }
+
+is_boolean_var: {
+    options = {
+        comparisons: true,
+        reduce_vars: true,
+    }
+    input: {
+        console.log(function(a, b) {
+            for (var i = 0, c = !b; i < a.length; i++)
+                if (!a[i] === c)
+                    return i;
+        }([ false, true ], 42));
+    }
+    expect: {
+        console.log(function(a, b) {
+            for (var i = 0, c = !b; i < a.length; i++)
+                if (!a[i] == c)
+                    return i;
+        }([ false, true ], 42));
+    }
+    expect_stdout: "1"
+}

test/compress/conditionals.js

@@ -1367,6 +1367,7 @@ cond_seq_assign_2: {
 
 cond_seq_assign_3: {
     options = {
+        assignments: true,
         conditionals: true,
     }
     input: {

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
 }
@@ -1540,7 +1540,7 @@ issue_2926_2: {
     expect_stdout: "function"
 }
 
-issue_2968: {
+issue_2968_1: {
     options = {
         collapse_vars: true,
         evaluate: true,
@@ -1571,6 +1571,39 @@ issue_2968: {
     expect_stdout: "PASS"
 }
 
+issue_2968_2: {
+    options = {
+        assignments: true,
+        collapse_vars: true,
+        evaluate: true,
+        inline: true,
+        passes: 2,
+        reduce_vars: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        var c = "FAIL";
+        (function() {
+            (function(a, b) {
+                a <<= 0;
+                a && (a[(c = "PASS", 0 >>> (b += 1))] = 0);
+            })(42, -42);
+        })();
+        console.log(c);
+    }
+    expect: {
+        var c = "FAIL";
+        (function() {
+            a = 42,
+            ((a <<= 0) && (a[(c = "PASS", 0)] = 0));
+            var a;
+        })();
+        console.log(c);
+    }
+    expect_stdout: "PASS"
+}
+
 truthy_conditionals: {
     options = {
         conditionals: true,
@@ -1610,3 +1643,47 @@ truthy_loops: {
         }
     }
 }
+
+if_increment: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        console.log(function(a) {
+            if (console)
+                return ++a;
+        }(0));
+    }
+    expect: {
+        console.log(function(a) {
+            if (console)
+                return 1;
+        }());
+    }
+    expect_stdout: "1"
+}
+
+try_increment: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        console.log(function(a) {
+            try {
+                return ++a;
+            } catch (e) {}
+        }(0));
+    }
+    expect: {
+        console.log(function(a) {
+            try {
+                return 1;
+            } catch (e) {}
+        }());
+    }
+    expect_stdout: "1"
+}

test/compress/functions.js

@@ -358,6 +358,7 @@ inner_ref: {
 
 issue_2107: {
     options = {
+        assignments: true,
         collapse_vars: true,
         inline: true,
         passes: 3,
@@ -387,6 +388,7 @@ issue_2107: {
 
 issue_2114_1: {
     options = {
+        assignments: true,
         collapse_vars: true,
         if_return: true,
         inline: true,
@@ -419,6 +421,7 @@ issue_2114_1: {
 
 issue_2114_2: {
     options = {
+        assignments: true,
         collapse_vars: true,
         if_return: true,
         inline: true,
@@ -1223,6 +1226,7 @@ issue_2630_1: {
 
 issue_2630_2: {
     options = {
+        assignments: true,
         collapse_vars: true,
         inline: true,
         passes: 2,
@@ -1320,6 +1324,7 @@ issue_2630_4: {
 
 issue_2630_5: {
     options = {
+        assignments: true,
         collapse_vars: true,
         inline: true,
         reduce_vars: true,
@@ -1398,6 +1403,8 @@ recursive_inline_2: {
 issue_2657: {
     options = {
         inline: true,
+        passes: 2,
+        reduce_funcs: true,
         reduce_vars: true,
         sequences: true,
         unused: true,
@@ -2467,6 +2474,7 @@ issue_3297_3: {
         inline: true,
         join_vars: true,
         passes: 3,
+        reduce_funcs: true,
         reduce_vars: true,
         sequences: true,
         side_effects: true,
@@ -2505,18 +2513,18 @@ issue_3297_3: {
         }).processBulk([1, 2, 3]);
     }
     expect: {
-        function function1(c) {
+        function function1(u) {
             return {
-                processBulk: function n(o) {
-                    var r, t, u = c();
-                    o && 0 < o.length && (r = {
-                        param1: o.shift(),
+                processBulk: function n(r) {
+                    var o, t = u();
+                    r && 0 < r.length && (o = {
+                        param1: r.shift(),
                         param2: {
-                            subparam1: u
+                            subparam1: t
                         }
-                    }, t = function() {
-                        n(o);
-                    }, console.log(JSON.stringify(r)), t());
+                    },
+                    console.log(JSON.stringify(o)),
+                    n(r));
                 }
             };
         }
@@ -2530,3 +2538,477 @@ issue_3297_3: {
         '{"param1":3,"param2":{"subparam1":42}}',
     ]
 }
+
+cross_references_1: {
+    options = {
+        inline: true,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        var Math = {
+            square: function(n) {
+                return n * n;
+            }
+        };
+        console.log((function(factory) {
+            return factory();
+        })(function() {
+            return function(Math) {
+                return function(n) {
+                    return Math.square(n);
+                };
+            }(Math);
+        })(3));
+    }
+    expect: {
+        var Math = {
+            square: function(n) {
+                return n * n;
+            }
+        };
+        console.log(function(Math) {
+            return function(n) {
+                return Math.square(n);
+            };
+        }(Math)(3));
+    }
+    expect_stdout: "9"
+}
+
+cross_references_2: {
+    options = {
+        collapse_vars: true,
+        evaluate: true,
+        hoist_props: true,
+        inline: true,
+        passes: 4,
+        pure_getters: true,
+        reduce_vars: true,
+        sequences: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var Math = {
+            square: function(n) {
+                return n * n;
+            }
+        };
+        console.log((function(factory) {
+            return factory();
+        })(function() {
+            return function(Math) {
+                return function(n) {
+                    return Math.square(n);
+                };
+            }(Math);
+        })(3));
+    }
+    expect: {
+        console.log(9);
+    }
+    expect_stdout: "9"
+}
+
+cross_references_3: {
+    options = {
+        inline: true,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        var Math = {
+            square: function(n) {
+                return n * n;
+            },
+            cube: function(n) {
+                return n * n * n;
+            }
+        };
+        console.log(function(factory) {
+            return factory();
+        }(function() {
+            return function(Math) {
+                return function(n) {
+                    Math = {
+                        square: function(x) {
+                            return "(SQUARE" + x + ")";
+                        },
+                        cube: function(x) {
+                            return "(CUBE" + x + ")";
+                        }
+                    };
+                    return Math.square(n) + Math.cube(n);
+                };
+            }(Math);
+        })(2));
+        console.log(Math.square(3), Math.cube(3));
+    }
+    expect: {
+        var Math = {
+            square: function(n) {
+                return n * n;
+            },
+            cube: function(n) {
+                return n * n * n;
+            }
+        };
+        console.log(function(Math) {
+            return function(n) {
+                Math = {
+                    square: function(x) {
+                        return "(SQUARE" + x + ")";
+                    },
+                    cube: function(x) {
+                        return "(CUBE" + x + ")";
+                    }
+                };
+                return Math.square(n) + Math.cube(n);
+            };
+        }(Math)(2));
+        console.log(Math.square(3), Math.cube(3));
+    }
+    expect_stdout: [
+        "(SQUARE2)(CUBE2)",
+        "9 27",
+    ]
+}
+
+loop_inline: {
+    options = {
+        inline: true,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        console.log(function(o) {
+            function g(p) {
+                return o[p];
+            }
+            function h(q) {
+                while (g(q));
+            }
+            return h;
+        }([ 1, "foo", 0 ])(2));
+    }
+    expect: {
+        console.log(function(o) {
+            return function(q) {
+                while (p = q, o[p]);
+                var p;
+            };
+        }([ 1, "foo", 0 ])(2));
+    }
+    expect_stdout: "undefined"
+}
+
+functions: {
+    options = {
+        functions: true,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        !function() {
+            var a = function() {
+                return "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";
+            }
+            var b = function x() {
+                return !!x;
+            };
+            var c = function(c) {
+                return c;
+            };
+            if (c(b(a()))) {
+                function d() {}
+                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"
+}
+
+functions_use_strict: {
+    options = {
+        functions: true,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        "use strict";
+        !function() {
+            var a = function() {
+                return "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";
+            }
+            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_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: {
+        (function() {
+            function a() {}
+            (function() {
+                this && a && console.log("PASS");
+            })();
+        })();
+    }
+    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/reduce_vars.js

@@ -6716,3 +6716,24 @@ issue_3297: {
     }
     expect_stdout: "true"
 }
+
+drop_side_effect_free: {
+    options = {
+        collapse_vars: true,
+        evaluate: true,
+        reduce_vars: true,
+        side_effects: true,
+        toplevel: true,
+    }
+    input: {
+        var a = 123;
+        "" + (a && (a.b = 0) || a);
+        console.log(a);
+    }
+    expect: {
+        var a = 123;
+        a.b = 0;
+        console.log(a);
+    }
+    expect_stdout: "123"
+}

test/compress/sequences.js

@@ -924,14 +924,14 @@ call: {
         b.c = function() {
             console.log(this === b ? "bar" : "baz");
         },
-        a, b(),
+        b(),
         (a, b.c)(),
-        a, function() {
+        function() {
             console.log(this === a);
         }(),
-        a, new b(),
-        a, new b.c(),
-        a, new function() {
+        new b(),
+        new b.c(),
+        new function() {
             console.log(this === a);
         }();
     }
@@ -944,3 +944,23 @@ call: {
         "false",
     ]
 }
+
+missing_link: {
+    options = {
+        conditionals: true,
+        evaluate: true,
+        sequences: true,
+    }
+    input: {
+        var a = 100;
+        a;
+        a++ + (0 ? 2 : 1);
+        console.log(a);
+    }
+    expect: {
+        var a = 100;
+        a,
+        a++,
+        console.log(a);
+    }
+}

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/mocha/cli.js

@@ -1,6 +1,7 @@
 var assert = require("assert");
 var exec = require("child_process").exec;
 var fs = require("fs");
+var run_code = require("../sandbox").run_code;
 
 function read(path) {
     return fs.readFileSync(path, "utf8");
@@ -714,4 +715,32 @@ describe("bin/uglifyjs", function() {
             done();
         });
     });
+    it("Should compress swarm of unused variables with reasonable performance", function(done) {
+        var code = [
+            "console.log(function() {",
+        ];
+        for (var i = 0; i < 10000; i++) {
+            code.push("var obj" + i + " = {p: " + i + "};");
+        }
+        code.push("var map = {");
+        for (var i = 0; i < 10000; i++) {
+            code.push("obj" + i + ": obj" + i + ",");
+        }
+        code = code.concat([
+            "};",
+            "return obj25.p + obj121.p + obj1024.p;",
+            "}());",
+        ]).join("\n");
+        exec(uglifyjscmd + " -mc", function(err, stdout) {
+            if (err) throw err;
+            assert.strictEqual(stdout, [
+                "console.log(function(){",
+                "var p={p:25},n={p:121},o={p:1024};",
+                "return p.p+n.p+o.p",
+                "}());\n",
+            ].join(""));
+            assert.strictEqual(run_code(stdout), run_code(code));
+            done();
+        }).stdin.end(code);
+    });
 });

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);
         }
     }
 };