v3.1.6

- trim array items only if `side_effects`
- extend to non-identifier properties

README.md

@@ -153,10 +153,10 @@ Additional options:
 - `--source-map "filename='<NAME>'"` to specify the name of the source map.
 
 - `--source-map "root='<URL>'"` to pass the URL where the original files can be found.
-  Otherwise UglifyJS assumes HTTP `X-SourceMap` is being used and will omit the
-  `//# sourceMappingURL=` directive.
 
 - `--source-map "url='<URL>'"` to specify the URL where the source map can be found.
+  Otherwise UglifyJS assumes HTTP `X-SourceMap` is being used and will omit the
+  `//# sourceMappingURL=` directive.
 
 For example:
 
@@ -203,11 +203,9 @@ Example:
 To enable the mangler you need to pass `--mangle` (`-m`).  The following
 (comma-separated) options are supported:
 
-- `toplevel` — mangle names declared in the top level scope (disabled by
-  default).
+- `toplevel` (default `false`) -- mangle names declared in the top level scope.
 
-- `eval` — mangle names visible in scopes where `eval` or `with` are used
-  (disabled by default).
+- `eval` (default `false`) -- mangle names visible in scopes where `eval` or `with` are used.
 
 When mangling is enabled but you want to prevent certain names from being
 mangled, you can declare those names with `--mangle reserved` — pass a
@@ -223,7 +221,7 @@ to prevent the `require`, `exports` and `$` names from being changed.
 is a separate step, different from variable name mangling.  Pass
 `--mangle-props` to enable it.  It will mangle all properties in the
 input code with the exception of built in DOM properties and properties
-in core javascript classes.  For example:
+in core JavaScript classes.  For example:
 
 ```javascript
 // example.js
@@ -238,7 +236,7 @@ x.bar_ = 2;
 x["baz_"] = 3;
 console.log(x.calc());
 ```
-Mangle all properties (except for javascript `builtins`):
+Mangle all properties (except for JavaScript `builtins`):
 ```bash
 $ uglifyjs example.js -c -m --mangle-props
 ```
@@ -510,11 +508,13 @@ if (result.error) throw result.error;
 
 - `ie8` (default `false`) - set to `true` to support IE8.
 
+- `keep_fnames` (default: `false`) - pass `true` to prevent discarding or mangling
+  of function names.  Useful for code relying on `Function.prototype.name`.
+
 ## Minify options structure
 
 ```javascript
 {
-    warnings: false,
     parse: {
         // parse options
     },
@@ -537,6 +537,7 @@ if (result.error) throw result.error;
     nameCache: null, // or specify a name cache object
     toplevel: false,
     ie8: false,
+    warnings: false,
 }
 ```
 
@@ -590,111 +591,88 @@ If you're using the `X-SourceMap` header instead, you can just omit `sourceMap.u
 ## Parse options
 
 - `bare_returns` (default `false`) -- support top level `return` statements
+
 - `html5_comments` (default `true`)
+
 - `shebang` (default `true`) -- support `#!command` as the first line
 
 ## Compress options
 
-- `sequences` (default: true) -- join consecutive simple statements using the
-  comma operator.  May be set to a positive integer to specify the maximum number
-  of consecutive comma sequences that will be generated. If this option is set to
-  `true` then the default `sequences` limit is `200`. Set option to `false` or `0`
-  to disable. The smallest `sequences` length is `2`. A `sequences` value of `1`
-  is grandfathered to be equivalent to `true` and as such means `200`. On rare
-  occasions the default sequences limit leads to very slow compress times in which
-  case a value of `20` or less is recommended.
+- `booleans` (default: `true`) -- various optimizations for boolean context, for example `!!a
+  ? b : c → a ? b : c`
 
-- `properties` -- rewrite property access using the dot notation, for
-  example `foo["bar"] → foo.bar`
+- `cascade` (default: `true`) -- small optimization for sequences, transform `x, x` into `x`
+  and `x = something(), x` into `x = something()`
 
-- `dead_code` -- remove unreachable code
+- `collapse_vars` (default: `true`) -- Collapse single-use non-constant variables - side
+  effects permitting.
 
-- `drop_debugger` -- remove `debugger;` statements
-
-- `unsafe` (default: false) -- apply "unsafe" transformations (discussion below)
-
-- `unsafe_comps` (default: false) -- Reverse `<` and `<=` to `>` and `>=` to
-  allow improved compression. This might be unsafe when an at least one of two
-  operands is an object with computed values due the use of methods like `get`,
-  or `valueOf`. This could cause change in execution order after operands in the
-  comparison are switching. Compression only works if both `comparisons` and
-  `unsafe_comps` are both set to true.
-
-- `unsafe_Func` (default: false) -- compress and mangle `Function(args, code)`
-  when both `args` and `code` are string literals.
-
-- `unsafe_math` (default: false) -- optimize numerical expressions like
-  `2 * x * 3` into `6 * x`, which may give imprecise floating point results.
-
-- `unsafe_proto` (default: false) -- optimize expressions like
-  `Array.prototype.slice.call(a)` into `[].slice.call(a)`
-
-- `unsafe_regexp` (default: false) -- enable substitutions of variables with
-  `RegExp` values the same way as if they are constants.
-
-- `conditionals` -- apply optimizations for `if`-s and conditional
-  expressions
-
-- `comparisons` -- apply certain optimizations to binary nodes, for example:
+- `comparisons` (default: `true`) -- apply certain optimizations to binary nodes, for example:
   `!(a <= b) → a > b` (only when `unsafe_comps`), attempts to negate binary
   nodes, e.g. `a = !b && !c && !d && !e → a=!(b||c||d||e)` etc.
 
-- `evaluate` -- attempt to evaluate constant expressions
+- `conditionals` (default: `true`) -- apply optimizations for `if`-s and conditional
+  expressions
 
-- `booleans` -- various optimizations for boolean context, for example `!!a
-  ? b : c → a ? b : c`
+- `dead_code` (default: `true`) -- remove unreachable code
 
-- `typeofs` -- default `true`.  Transforms `typeof foo == "undefined"` into
-  `foo === void 0`.  Note: recommend to set this value to `false` for IE10 and
-  earlier versions due to known issues.
+- `drop_console` (default: `false`) -- default `false`.  Pass `true` to discard calls to
+  `console.*` functions. If you wish to drop a specific function call
+  such as `console.info` and/or retain side effects from function arguments
+  after dropping the function call then use `pure_funcs` instead.
 
-- `loops` -- optimizations for `do`, `while` and `for` loops when we can
-  statically determine the condition
+- `drop_debugger` (default: `true`) -- remove `debugger;` statements
 
-- `unused` -- drop unreferenced functions and variables (simple direct variable
-  assignments do not count as references unless set to `"keep_assign"`)
+- `evaluate` (default: `true`) -- attempt to evaluate constant expressions
 
-- `toplevel` -- drop unreferenced functions (`"funcs"`) and/or variables (`"vars"`)
-  in the top level scope (`false` by default, `true` to drop both unreferenced
-  functions and variables)
+- `expression` (default: `false`) -- default `false`.  Pass `true` to preserve completion values
+  from terminal statements without `return`, e.g. in bookmarklets.
 
-- `top_retain` -- prevent specific toplevel functions and variables from `unused`
-  removal (can be array, comma-separated, RegExp or function. Implies `toplevel`)
+- `global_defs` (default: `{}`) -- see [conditional compilation](#conditional-compilation)
 
-- `hoist_funs` -- hoist function declarations
+- `hoist_funs` (default: `true`) -- hoist function declarations
 
-- `hoist_vars` (default: false) -- hoist `var` declarations (this is `false`
+- `hoist_props` (default: `false`) -- hoist properties from constant object and
+  array literals into regular variables subject to a set of constraints. For example:
+  `var o={p:1, q:2}; f(o.p, o.q);` is converted to `f(1, 2);`. Note: `hoist_props`
+  works best with `mangle` enabled, the `compress` option `passes` set to `2` or higher,
+  and the `compress` option `toplevel` enabled.
+
+- `hoist_vars` (default: `false`) -- hoist `var` declarations (this is `false`
   by default because it seems to increase the size of the output in general)
 
-- `if_return` -- optimizations for if/return and if/continue
+- `if_return` (default: `true`) -- optimizations for if/return and if/continue
 
-- `inline` -- embed simple functions
+- `inline` (default: `true`) -- embed simple functions
 
-- `join_vars` -- join consecutive `var` statements
+- `join_vars` (default: `true`) -- join consecutive `var` statements
 
-- `cascade` -- small optimization for sequences, transform `x, x` into `x`
-  and `x = something(), x` into `x = something()`
+- `keep_fargs` (default: `true`) -- default `true`.  Prevents the
+  compressor from discarding unused function arguments.  You need this
+  for code which relies on `Function.length`.
 
-- `collapse_vars` -- Collapse single-use non-constant variables - side
-  effects permitting.
+- `keep_fnames` (default: `false`) -- Pass `true` to prevent the
+  compressor from discarding function names.  Useful for code relying on
+  `Function.prototype.name`. See also: the `keep_fnames` [mangle option](#mangle).
 
-- `reduce_vars` -- Improve optimization on variables assigned with and
-  used as constant values.
+- `keep_infinity` (default: `false`) -- default `false`. Pass `true` to prevent `Infinity` from
+  being compressed into `1/0`, which may cause performance issues on Chrome.
 
-- `warnings` -- display warnings when dropping unreachable code or unused
-  declarations etc.
+- `loops` (default: `true`) -- optimizations for `do`, `while` and `for` loops when we can
+  statically determine the condition
 
-- `negate_iife` -- negate "Immediately-Called Function Expressions"
+- `negate_iife` (default: `true`) -- negate "Immediately-Called Function Expressions"
   where the return value is discarded, to avoid the parens that the
   code generator would insert.
 
-- `pure_getters` -- the default is `false`.  If you pass `true` for
-  this, UglifyJS will assume that object property access
-  (e.g. `foo.bar` or `foo["bar"]`) doesn't have any side effects.
-  Specify `"strict"` to treat `foo.bar` as side-effect-free only when
-  `foo` is certain to not throw, i.e. not `null` or `undefined`.
+- `passes` (default: `1`) -- The maximum number of times to run compress.
+  In some cases more than one pass leads to further compressed code.  Keep in
+  mind more passes will take more time.
 
-- `pure_funcs` -- default `null`.  You can pass an array of names and
+- `properties` (default: `true`) -- rewrite property access using the dot notation, for
+  example `foo["bar"] → foo.bar`
+
+- `pure_funcs` (default: `null`) -- You can pass an array of names and
   UglifyJS will assume that those functions do not produce side
   effects.  DANGER: will not check if the name is redefined in scope.
   An example case here, for instance `var q = Math.floor(a/b)`.  If
@@ -705,49 +683,84 @@ If you're using the `X-SourceMap` header instead, you can just omit `sourceMap.u
   statement would get discarded.  The current implementation adds some
   overhead (compression will be slower).
 
-- `drop_console` -- default `false`.  Pass `true` to discard calls to
-  `console.*` functions. If you wish to drop a specific function call
-  such as `console.info` and/or retain side effects from function arguments
-  after dropping the function call then use `pure_funcs` instead.
+- `pure_getters` (default: `"strict"`) -- If you pass `true` for
+  this, UglifyJS will assume that object property access
+  (e.g. `foo.bar` or `foo["bar"]`) doesn't have any side effects.
+  Specify `"strict"` to treat `foo.bar` as side-effect-free only when
+  `foo` is certain to not throw, i.e. not `null` or `undefined`.
 
-- `expression` -- default `false`.  Pass `true` to preserve completion values
-  from terminal statements without `return`, e.g. in bookmarklets.
+- `reduce_vars` (default: `true`) -- Improve optimization on variables assigned with and
+  used as constant values.
 
-- `keep_fargs` -- default `true`.  Prevents the
-  compressor from discarding unused function arguments.  You need this
-  for code which relies on `Function.length`.
+- `sequences` (default: `true`) -- join consecutive simple statements using the
+  comma operator.  May be set to a positive integer to specify the maximum number
+  of consecutive comma sequences that will be generated. If this option is set to
+  `true` then the default `sequences` limit is `200`. Set option to `false` or `0`
+  to disable. The smallest `sequences` length is `2`. A `sequences` value of `1`
+  is grandfathered to be equivalent to `true` and as such means `200`. On rare
+  occasions the default sequences limit leads to very slow compress times in which
+  case a value of `20` or less is recommended.
 
-- `keep_fnames` -- default `false`.  Pass `true` to prevent the
-  compressor from discarding function names.  Useful for code relying on
-  `Function.prototype.name`. See also: the `keep_fnames` [mangle option](#mangle).
-
-- `passes` -- default `1`. The maximum number of times to run compress.
-  In some cases more than one pass leads to further compressed code.  Keep in
-  mind more passes will take more time.
-
-- `keep_infinity` -- default `false`. Pass `true` to prevent `Infinity` from
-  being compressed into `1/0`, which may cause performance issues on Chrome.
-
-- `side_effects` -- default `true`. Pass `false` to disable potentially dropping
+- `side_effects` (default: `true`) -- default `true`. Pass `false` to disable potentially dropping
   functions marked as "pure".  A function call is marked as "pure" if a comment
   annotation `/*@__PURE__*/` or `/*#__PURE__*/` immediately precedes the call. For
   example: `/*@__PURE__*/foo();`
 
+- `switches` (default: `true`) -- de-duplicate and remove unreachable `switch` branches
+
+- `toplevel` (default: `false`) -- drop unreferenced functions (`"funcs"`) and/or variables (`"vars"`)
+  in the top level scope (`false` by default, `true` to drop both unreferenced
+  functions and variables)
+
+- `top_retain` (default: `null`) -- prevent specific toplevel functions and variables from `unused`
+  removal (can be array, comma-separated, RegExp or function. Implies `toplevel`)
+
+- `typeofs` (default: `true`) -- default `true`.  Transforms `typeof foo == "undefined"` into
+  `foo === void 0`.  Note: recommend to set this value to `false` for IE10 and
+  earlier versions due to known issues.
+
+- `unsafe` (default: `false`) -- apply "unsafe" transformations (discussion below)
+
+- `unsafe_comps` (default: `false`) -- Reverse `<` and `<=` to `>` and `>=` to
+  allow improved compression. This might be unsafe when an at least one of two
+  operands is an object with computed values due the use of methods like `get`,
+  or `valueOf`. This could cause change in execution order after operands in the
+  comparison are switching. Compression only works if both `comparisons` and
+  `unsafe_comps` are both set to true.
+
+- `unsafe_Func` (default: `false`) -- compress and mangle `Function(args, code)`
+  when both `args` and `code` are string literals.
+
+- `unsafe_math` (default: `false`) -- optimize numerical expressions like
+  `2 * x * 3` into `6 * x`, which may give imprecise floating point results.
+
+- `unsafe_proto` (default: `false`) -- optimize expressions like
+  `Array.prototype.slice.call(a)` into `[].slice.call(a)`
+
+- `unsafe_regexp` (default: `false`) -- enable substitutions of variables with
+  `RegExp` values the same way as if they are constants.
+
+- `unused` (default: `true`) -- drop unreferenced functions and variables (simple direct variable
+  assignments do not count as references unless set to `"keep_assign"`)
+
+- `warnings` (default: `false`) -- display warnings when dropping unreachable code or unused
+  declarations etc.
+
 ## Mangle options
 
+- `eval` (default `false`). Pass `true` to mangle names visible in scopes
+  where `eval` or `with` are used.
+
+- `keep_fnames` (default `false`).  Pass `true` to not mangle function names.
+  Useful for code relying on `Function.prototype.name`. See also: the `keep_fnames`
+  [compress option](#compress-options).
+
 - `reserved` (default `[]`). Pass an array of identifiers that should be
   excluded from mangling. Example: `["foo", "bar"]`.
 
 - `toplevel` (default `false`). Pass `true` to mangle names declared in the
   top level scope.
 
-- `keep_fnames` (default `false`).  Pass `true` to not mangle function names.
-  Useful for code relying on `Function.prototype.name`. See also: the `keep_fnames`
-  [compress option](#compress-options).
-
-- `eval` (default `false`). Pass `true` to mangle names visible in scopes
-  where `eval` or `with` are used.
-
 Examples:
 
 ```javascript
@@ -772,16 +785,20 @@ UglifyJS.minify(code, { mangle: { toplevel: true } }).code;
 
 ### Mangle properties options
 
-- `reserved` (default: `[]`) -- Do not mangle property names listed in the
-  `reserved` array.
-- `regex` (default: `null`) -— Pass a RegExp literal to only mangle property
-  names matching the regular expression.
-- `keep_quoted` (default: `false`) -— Only mangle unquoted property names.
-- `debug` (default: `false`) -— Mangle names with the original name still present.
-  Pass an empty string `""` to enable, or a non-empty string to set the debug suffix.
 - `builtins` (default: `false`) -- Use `true` to allow the mangling of builtin
   DOM properties. Not recommended to override this setting.
 
+- `debug` (default: `false`) -— Mangle names with the original name still present.
+  Pass an empty string `""` to enable, or a non-empty string to set the debug suffix.
+
+- `keep_quoted` (default: `false`) -— Only mangle unquoted property names.
+
+- `regex` (default: `null`) -— Pass a RegExp literal to only mangle property
+  names matching the regular expression.
+
+- `reserved` (default: `[]`) -- Do not mangle property names listed in the
+  `reserved` array.
+
 ## Output options
 
 The code generator tries to output shortest code possible by default.  In
@@ -790,31 +807,43 @@ can pass additional arguments that control the code output:
 
 - `ascii_only` (default `false`) -- escape Unicode characters in strings and
   regexps (affects directives with non-ascii characters becoming invalid)
+
 - `beautify` (default `true`) -- whether to actually beautify the output.
   Passing `-b` will set this to true, but you might need to pass `-b` even
   when you want to generate minified code, in order to specify additional
   arguments, so you can use `-b beautify=false` to override it.
+
 - `bracketize` (default `false`) -- always insert brackets in `if`, `for`,
   `do`, `while` or `with` statements, even if their body is a single
   statement.
+
 - `comments` (default `false`) -- pass `true` or `"all"` to preserve all
   comments, `"some"` to preserve some comments, a regular expression string
   (e.g. `/^!/`) or a function.
-- `indent_level` (default 4)
-- `indent_start` (default 0) -- prefix all lines by that many spaces
+
+- `indent_level` (default `4`)
+
+- `indent_start` (default `0`) -- prefix all lines by that many spaces
+
 - `inline_script` (default `false`) -- escape the slash in occurrences of
   `</script` in strings
+
 - `keep_quoted_props` (default `false`) -- when turned on, prevents stripping
   quotes from property names in object literals.
+
 - `max_line_len` (default `false`) -- maximum line length (for uglified code)
+
 - `preamble` (default `null`) -- when passed it must be a string and
   it will be prepended to the output literally.  The source map will
   adjust for this text.  Can be used to insert a comment containing
   licensing information, for example.
+
 - `preserve_line` (default `false`) -- pass `true` to preserve lines, but it
   only works if `beautify` is set to `false`.
+
 - `quote_keys` (default `false`) -- pass `true` to quote all keys in literal
   objects
+
 - `quote_style` (default `0`) -- preferred quote style for strings (affects
   quoted property names and directives as well):
   - `0` -- prefers double quotes, switches to single quotes when there are
@@ -822,16 +851,20 @@ can pass additional arguments that control the code output:
   - `1` -- always use single quotes
   - `2` -- always use double quotes
   - `3` -- always use the original quotes
+
 - `semicolons` (default `true`) -- separate statements with semicolons.  If
   you pass `false` then whenever possible we will use a newline instead of a
   semicolon, leading to more readable output of uglified code (size before
   gzip could be smaller; size after gzip insignificantly larger).
+
 - `shebang` (default `true`) -- preserve shebang `#!` in preamble (bash scripts)
-- `width` (default 80) -- only takes effect when beautification is on, this
+
+- `width` (default `80`) -- only takes effect when beautification is on, this
   specifies an (orientative) line width that the beautifier will try to
   obey.  It refers to the width of the line text (excluding indentation).
   It doesn't work very well currently, but it does make the code generated
   by UglifyJS more readable.
+
 - `wrap_iife` (default `false`) -- pass `true` to wrap immediately invoked
   function expressions. See
   [#640](https://github.com/mishoo/UglifyJS2/issues/640) for more details.
@@ -1033,7 +1066,7 @@ in total it's a bit more than just using UglifyJS's own parser.
 ### Uglify Fast Minify Mode
 
 It's not well known, but whitespace removal and symbol mangling accounts
-for 95% of the size reduction in minified code for most javascript - not
+for 95% of the size reduction in minified code for most JavaScript - not
 elaborate code transforms. One can simply disable `compress` to speed up
 Uglify builds by 3 to 4 times. In this fast `mangle`-only mode Uglify has
 comparable minify speeds and gzip sizes to

lib/compress.js

@@ -60,6 +60,7 @@ function Compressor(options, false_by_default) {
         expression    : false,
         global_defs   : {},
         hoist_funs    : !false_by_default,
+        hoist_props   : false,
         hoist_vars    : false,
         ie8           : false,
         if_return     : !false_by_default,
@@ -151,7 +152,7 @@ merge(Compressor.prototype, {
         var last_count = 1 / 0;
         for (var pass = 0; pass < passes; pass++) {
             if (pass > 0 || this.option("reduce_vars"))
-                node.reset_opt_flags(this, true);
+                node.reset_opt_flags(this);
             node = node.transform(this);
             if (passes > 1) {
                 var count = 0;
@@ -190,6 +191,7 @@ merge(Compressor.prototype, {
         if (node._squeezed) return node;
         var was_scope = false;
         if (node instanceof AST_Scope) {
+            node = node.hoist_properties(this);
             node = node.hoist_declarations(this);
             was_scope = true;
         }
@@ -283,8 +285,13 @@ merge(Compressor.prototype, {
         self.transform(tt);
     });
 
-    AST_Node.DEFMETHOD("reset_opt_flags", function(compressor, rescan) {
-        var reduce_vars = rescan && compressor.option("reduce_vars");
+    AST_Node.DEFMETHOD("reset_opt_flags", function(compressor) {
+        var reduce_vars = compressor.option("reduce_vars");
+        var unused = compressor.option("unused");
+        // Stack of look-up tables to keep track of whether a `SymbolDef` has been
+        // properly assigned before use:
+        // - `push()` & `pop()` when visiting conditional branches
+        // - backup & restore via `save_ids` when visiting out-of-order sections
         var safe_ids = Object.create(null);
         var suppressor = new TreeWalker(function(node) {
             if (!(node instanceof AST_Symbol)) return;
@@ -293,6 +300,8 @@ merge(Compressor.prototype, {
             if (node instanceof AST_SymbolRef) d.references.push(node);
             d.fixed = false;
         });
+        var in_loop = null;
+        var loop_ids = Object.create(null);
         var tw = new TreeWalker(function(node, descend) {
             node._squeezed = false;
             node._optimized = false;
@@ -302,16 +311,25 @@ merge(Compressor.prototype, {
                 if (node instanceof AST_SymbolRef) {
                     var d = node.definition();
                     d.references.push(node);
-                    if (d.fixed === undefined || !safe_to_read(d)
-                        || is_modified(node, 0, is_immutable(node.fixed_value()))) {
+                    if (d.fixed === undefined || !safe_to_read(d) || d.single_use == "m") {
                         d.fixed = false;
-                    } else {
-                        var parent = tw.parent();
-                        if (parent instanceof AST_Assign && parent.operator == "=" && node === parent.right
-                            || parent instanceof AST_Call && node !== parent.expression
-                            || parent instanceof AST_Return && node === parent.value && node.scope !== d.scope
-                            || parent instanceof AST_VarDef && node === parent.value) {
-                            d.escaped = true;
+                    } else if (d.fixed) {
+                        var value = node.fixed_value();
+                        if (unused) {
+                            d.single_use = value
+                                && d.references.length == 1
+                                && loop_ids[d.id] === in_loop
+                                && d.scope === node.scope
+                                && value.is_constant_expression();
+                        }
+                        if (is_modified(node, value, 0, is_immutable(value))) {
+                            if (d.single_use) {
+                                d.single_use = "m";
+                            } else {
+                                d.fixed = false;
+                            }
+                        } else {
+                            mark_escaped(d, node, value, 0);
                         }
                     }
                 }
@@ -325,6 +343,7 @@ merge(Compressor.prototype, {
                             d.fixed = function() {
                                 return node.value;
                             };
+                            loop_ids[d.id] = in_loop;
                             mark(d, false);
                             descend();
                         } else {
@@ -380,6 +399,7 @@ merge(Compressor.prototype, {
                                 d.fixed = function() {
                                     return iife.args[i] || make_node(AST_Undefined, iife);
                                 };
+                                loop_ids[d.id] = in_loop;
                                 mark(d, true);
                             } else {
                                 d.fixed = false;
@@ -391,14 +411,12 @@ merge(Compressor.prototype, {
                     return true;
                 }
                 if (node instanceof AST_Accessor) {
-                    var save_ids = safe_ids;
-                    safe_ids = Object.create(null);
+                    push();
                     descend();
-                    safe_ids = save_ids;
+                    pop();
                     return true;
                 }
-                if (node instanceof AST_Binary
-                    && (node.operator == "&&" || node.operator == "||")) {
+                if (node instanceof AST_Binary && lazy_op(node.operator)) {
                     node.left.walk(tw);
                     push();
                     node.right.walk(tw);
@@ -428,10 +446,13 @@ merge(Compressor.prototype, {
                     return true;
                 }
                 if (node instanceof AST_DWLoop) {
+                    var saved_loop = in_loop;
+                    in_loop = node;
                     push();
                     node.condition.walk(tw);
                     node.body.walk(tw);
                     pop();
+                    in_loop = saved_loop;
                     return true;
                 }
                 if (node instanceof AST_LabeledStatement) {
@@ -442,6 +463,8 @@ merge(Compressor.prototype, {
                 }
                 if (node instanceof AST_For) {
                     if (node.init) node.init.walk(tw);
+                    var saved_loop = in_loop;
+                    in_loop = node;
                     if (node.condition) {
                         push();
                         node.condition.walk(tw);
@@ -455,14 +478,18 @@ merge(Compressor.prototype, {
                         node.step.walk(tw);
                         pop();
                     }
+                    in_loop = saved_loop;
                     return true;
                 }
                 if (node instanceof AST_ForIn) {
                     node.init.walk(suppressor);
                     node.object.walk(tw);
+                    var saved_loop = in_loop;
+                    in_loop = node;
                     push();
                     node.body.walk(tw);
                     pop();
+                    in_loop = saved_loop;
                     return true;
                 }
                 if (node instanceof AST_Try) {
@@ -522,6 +549,7 @@ merge(Compressor.prototype, {
         }
 
         function reset_def(def) {
+            def.direct_access = false;
             def.escaped = false;
             if (def.scope.uses_eval) {
                 def.fixed = false;
@@ -532,24 +560,68 @@ merge(Compressor.prototype, {
             }
             def.references = [];
             def.should_replace = undefined;
+            def.single_use = undefined;
         }
 
         function is_immutable(value) {
-            return value && value.is_constant() || value instanceof AST_Lambda;
+            return value && (value.is_constant() || value instanceof AST_Lambda);
         }
 
-        function is_modified(node, level, immutable) {
+        function read_property(obj, key) {
+            if (key instanceof AST_Constant) key = key.getValue();
+            if (key instanceof AST_Node) return null;
+            var value;
+            if (obj instanceof AST_Array) {
+                var elements = obj.elements;
+                if (key == "length") return make_node_from_constant(elements.length, obj);
+                if (typeof key == "number" && key in elements) value = elements[key];
+            } else if (obj instanceof AST_Object) {
+                var props = obj.properties;
+                for (var i = props.length; --i >= 0;) {
+                    var prop = props[i];
+                    if (!(prop instanceof AST_ObjectKeyVal)) return;
+                    if (!value && props[i].key === key) value = props[i].value;
+                }
+            }
+            return value instanceof AST_SymbolRef && value.fixed_value() || value;
+        }
+
+        function is_modified(node, value, level, immutable) {
             var parent = tw.parent(level);
             if (is_lhs(node, parent)
-                || !immutable && parent instanceof AST_Call && parent.expression === node) {
+                || !immutable
+                    && parent instanceof AST_Call
+                    && parent.expression === node
+                    && (!(value instanceof AST_Function) || value.contains_this())) {
                 return true;
+            } else if (parent instanceof AST_Array || parent instanceof AST_Object) {
+                return is_modified(parent, parent, level + 1);
             } else if (parent instanceof AST_PropAccess && parent.expression === node) {
-                return !immutable && is_modified(parent, level + 1);
+                return !immutable && is_modified(parent, read_property(value, parent.property), level + 1);
             }
         }
+
+        function mark_escaped(d, node, value, level) {
+            var parent = tw.parent(level);
+            if (value instanceof AST_Constant || value instanceof AST_Function) return;
+            if (parent instanceof AST_Assign && parent.operator == "=" && node === parent.right
+                || parent instanceof AST_Call && node !== parent.expression
+                || parent instanceof AST_Return && node === parent.value && node.scope !== d.scope
+                || parent instanceof AST_VarDef && node === parent.value) {
+                d.escaped = true;
+                return;
+            } else if (parent instanceof AST_Array || parent instanceof AST_Object) {
+                mark_escaped(d, parent, parent, level + 1);
+            } else if (parent instanceof AST_PropAccess && node === parent.expression) {
+                value = read_property(value, parent.property);
+                mark_escaped(d, parent, value, level + 1);
+                if (value) return;
+            }
+            if (level == 0) d.direct_access = true;
+        }
     });
 
-    AST_SymbolRef.DEFMETHOD("fixed_value", function() {
+    AST_Symbol.DEFMETHOD("fixed_value", function() {
         var fixed = this.definition().fixed;
         if (!fixed || fixed instanceof AST_Node) return fixed;
         return fixed();
@@ -750,6 +822,7 @@ merge(Compressor.prototype, {
                     // Locate symbols which may execute code outside of scanning range
                     var lvalues = get_lvalues(candidate);
                     if (lhs instanceof AST_SymbolRef) lvalues[lhs.name] = false;
+                    var one_off = lhs instanceof AST_Symbol && lhs.definition().references.length == 1;
                     var side_effects = value_has_side_effects(candidate);
                     var hit = candidate.name instanceof AST_SymbolFunarg;
                     var abort = false, replaced = false;
@@ -810,16 +883,17 @@ merge(Compressor.prototype, {
                         if (node instanceof AST_Call
                             || node instanceof AST_Exit
                             || node instanceof AST_PropAccess
+                                && (side_effects || node.expression.may_throw_on_access(compressor))
                             || node instanceof AST_SymbolRef
                                && (lvalues[node.name]
                                    || side_effects && !references_in_scope(node.definition()))
-                            || (sym = lhs_or_def(node)) && get_symbol(sym).name in lvalues
-                            || parent instanceof AST_Binary
-                                && (parent.operator == "&&" || parent.operator == "||")
-                            || parent instanceof AST_Case
-                            || parent instanceof AST_Conditional
-                            || parent instanceof AST_For
-                            || parent instanceof AST_If) {
+                            || (sym = lhs_or_def(node))
+                                && (sym instanceof AST_PropAccess || sym.name in lvalues)
+                            || (side_effects || !one_off)
+                                && (parent instanceof AST_Binary && lazy_op(parent.operator)
+                                    || parent instanceof AST_Case
+                                    || parent instanceof AST_Conditional
+                                    || parent instanceof AST_If)) {
                             if (!(node instanceof AST_Scope)) descend(node, tt);
                             abort = true;
                             return node;
@@ -905,27 +979,14 @@ merge(Compressor.prototype, {
                 }
             }
 
-            function get_symbol(node) {
-                while (node instanceof AST_PropAccess) node = node.expression;
-                return node;
-            }
-
             function get_lvalues(expr) {
                 var lvalues = Object.create(null);
                 if (expr instanceof AST_Unary) return lvalues;
-                var scope;
                 var tw = new TreeWalker(function(node, descend) {
-                    if (node instanceof AST_Scope) {
-                        var save_scope = scope;
-                        descend();
-                        scope = save_scope;
-                        return true;
-                    }
-                    if (node instanceof AST_SymbolRef || node instanceof AST_PropAccess) {
-                        var sym = get_symbol(node);
-                        if (sym instanceof AST_SymbolRef) {
-                            lvalues[sym.name] = lvalues[sym.name] || is_lhs(node, tw.parent());
-                        }
+                    var sym = node;
+                    while (sym instanceof AST_PropAccess) sym = sym.expression;
+                    if (sym instanceof AST_SymbolRef || sym instanceof AST_This) {
+                        lvalues[sym.name] = lvalues[sym.name] || is_lhs(node, tw.parent());
                     }
                 });
                 expr[expr instanceof AST_Assign ? "right" : "value"].walk(tw);
@@ -1402,9 +1463,10 @@ merge(Compressor.prototype, {
             return member(this.operator, unary_bool);
         });
         def(AST_Binary, function(){
-            return member(this.operator, binary_bool) ||
-                ( (this.operator == "&&" || this.operator == "||") &&
-                  this.left.is_boolean() && this.right.is_boolean() );
+            return member(this.operator, binary_bool)
+                || lazy_op(this.operator)
+                    && this.left.is_boolean()
+                    && this.right.is_boolean();
         });
         def(AST_Conditional, function(){
             return this.consequent.is_boolean() && this.alternative.is_boolean();
@@ -1473,6 +1535,7 @@ merge(Compressor.prototype, {
         node.DEFMETHOD("is_string", func);
     });
 
+    var lazy_op = makePredicate("&& ||");
     var unary_side_effects = makePredicate("delete ++ --");
 
     function is_lhs(node, parent) {
@@ -1584,35 +1647,6 @@ merge(Compressor.prototype, {
                     && unaryPrefix(this.operator);
             }
         });
-        // Obtain the constant value of an expression already known to be constant.
-        // Result only valid iff this.is_constant() is true.
-        AST_Node.DEFMETHOD("constant_value", function(compressor){
-            // Accomodate when option evaluate=false.
-            if (this instanceof AST_Constant && !(this instanceof AST_RegExp)) {
-                return this.value;
-            }
-            // Accomodate the common constant expressions !0 and -1 when option evaluate=false.
-            if (this instanceof AST_UnaryPrefix
-                && this.expression instanceof AST_Constant) switch (this.operator) {
-              case "!":
-                return !this.expression.value;
-              case "~":
-                return ~this.expression.value;
-              case "-":
-                return -this.expression.value;
-              case "+":
-                return +this.expression.value;
-              default:
-                throw new Error(string_template("Cannot evaluate unary expression {value}", {
-                    value: this.print_to_string()
-                }));
-            }
-            var result = this.evaluate(compressor);
-            if (result !== this) {
-                return result;
-            }
-            throw new Error(string_template("Cannot evaluate constant [{file}:{line},{col}]", this.start));
-        });
         def(AST_Statement, function(){
             throw new Error(string_template("Cannot evaluate a statement [{file}:{line},{col}]", this.start));
         });
@@ -1631,6 +1665,7 @@ merge(Compressor.prototype, {
                 var elements = [];
                 for (var i = 0, len = this.elements.length; i < len; i++) {
                     var element = this.elements[i];
+                    if (element instanceof AST_Function) continue;
                     var value = ev(element, compressor);
                     if (element === value) return this;
                     elements.push(value);
@@ -1654,6 +1689,7 @@ merge(Compressor.prototype, {
                     if (typeof Object.prototype[key] === 'function') {
                         return this;
                     }
+                    if (prop.value instanceof AST_Function) continue;
                     val[key] = ev(prop.value, compressor);
                     if (val[key] === prop.value) return this;
                 }
@@ -2112,6 +2148,22 @@ merge(Compressor.prototype, {
         }
         def(AST_Node, return_false);
         def(AST_Constant, return_true);
+        def(AST_Function, function(){
+            var self = this;
+            var result = true;
+            self.walk(new TreeWalker(function(node) {
+                if (!result) return true;
+                if (node instanceof AST_SymbolRef) {
+                    var def = node.definition();
+                    if (self.enclosed.indexOf(def) >= 0
+                        && self.variables.get(def.name) !== def) {
+                        result = false;
+                        return true;
+                    }
+                }
+            }));
+            return result;
+        });
         def(AST_Unary, function(){
             return this.expression.is_constant_expression();
         });
@@ -2195,7 +2247,6 @@ merge(Compressor.prototype, {
         if (self.uses_eval || self.uses_with) return;
         var drop_funcs = !(self instanceof AST_Toplevel) || compressor.toplevel.funcs;
         var drop_vars = !(self instanceof AST_Toplevel) || compressor.toplevel.vars;
-        if (!drop_funcs && !drop_vars) return;
         var assign_as_unused = /keep_assign/.test(compressor.option("unused")) ? return_false : function(node) {
             if (node instanceof AST_Assign && (node.write_only || node.operator == "=")) {
                 return node.left;
@@ -2330,7 +2381,8 @@ merge(Compressor.prototype, {
                     }
                     return node;
                 }
-                if (drop_vars && node instanceof AST_Definitions && !(tt.parent() instanceof AST_ForIn && tt.parent().init === node)) {
+                var parent = tt.parent();
+                if (node instanceof AST_Definitions && !(parent instanceof AST_ForIn && parent.init === node)) {
                     // place uninitialized names at the start
                     var body = [], head = [], tail = [];
                     // for unused names whose initialization has
@@ -2340,7 +2392,7 @@ merge(Compressor.prototype, {
                     node.definitions.forEach(function(def) {
                         if (def.value) def.value = def.value.transform(tt);
                         var sym = def.name.definition();
-                        if (sym.id in in_use_ids) {
+                        if (!drop_vars || sym.id in in_use_ids) {
                             if (def.name instanceof AST_SymbolVar) {
                                 var var_defs = var_defs_by_id.get(sym.id);
                                 if (var_defs.length > 1 && !def.value) {
@@ -2406,11 +2458,11 @@ merge(Compressor.prototype, {
                         }));
                     }
                     switch (body.length) {
-                        case 0:
+                      case 0:
                         return in_list ? MAP.skip : make_node(AST_EmptyStatement, node);
-                        case 1:
+                      case 1:
                         return body[0];
-                        default:
+                      default:
                         return in_list ? MAP.splice(body) : make_node(AST_BlockStatement, node, {
                             body: body
                         });
@@ -2422,7 +2474,7 @@ merge(Compressor.prototype, {
                         && !((def = def.definition()).id in in_use_ids)
                         && self.variables.get(def.name) === def) {
                         if (node instanceof AST_Assign) {
-                            return maintain_this_binding(tt.parent(), node, node.right.transform(tt));
+                            return maintain_this_binding(parent, node, node.right.transform(tt));
                         }
                         return make_node(AST_Number, node, {
                             value: 0
@@ -2606,6 +2658,71 @@ merge(Compressor.prototype, {
         return self;
     });
 
+    AST_Scope.DEFMETHOD("hoist_properties", function(compressor){
+        var self = this;
+        if (!compressor.option("hoist_props") || compressor.has_directive("use asm")) return self;
+        var defs_by_id = Object.create(null);
+        var var_names = Object.create(null);
+        self.enclosed.forEach(function(def) {
+            var_names[def.name] = true;
+        });
+        self.variables.each(function(def, name) {
+            var_names[name] = true;
+        });
+        return self.transform(new TreeTransformer(function(node) {
+            if (node instanceof AST_VarDef) {
+                var sym = node.name, def, value;
+                if (sym.scope === self
+                    && !(def = sym.definition()).escaped
+                    && !def.single_use
+                    && !def.direct_access
+                    && (value = sym.fixed_value()) === node.value
+                    && value instanceof AST_Object) {
+                    var defs = new Dictionary();
+                    var assignments = [];
+                    value.properties.forEach(function(prop) {
+                        assignments.push(make_node(AST_VarDef, node, {
+                            name: make_sym(prop.key),
+                            value: prop.value
+                        }));
+                    });
+                    defs_by_id[def.id] = defs;
+                    return MAP.splice(assignments);
+                }
+            }
+            if (node instanceof AST_PropAccess && node.expression instanceof AST_SymbolRef) {
+                var defs = defs_by_id[node.expression.definition().id];
+                if (defs) {
+                    var key = node.property;
+                    if (key instanceof AST_Node) key = key.getValue();
+                    var def = defs.get(key);
+                    var sym = make_node(AST_SymbolRef, node, {
+                        name: def.name,
+                        scope: node.expression.scope,
+                        thedef: def
+                    });
+                    sym.reference({});
+                    return sym;
+                }
+            }
+
+            function make_sym(key) {
+                var prefix = sym.name + "_" + key.toString().replace(/[^a-z_$]+/ig, "_");
+                var name = prefix;
+                for (var i = 0; var_names[name]; i++) name = prefix + "$" + i;
+                var new_var = make_node(sym.CTOR, sym, {
+                    name: name,
+                    scope: self
+                });
+                var def = self.def_variable(new_var);
+                defs.set(key, def);
+                self.enclosed.push(def);
+                var_names[name] = true;
+                return new_var;
+            }
+        }));
+    });
+
     // drop_side_effect_free()
     // remove side-effect-free parts which only affects return value
     (function(def){
@@ -2653,14 +2770,12 @@ merge(Compressor.prototype, {
         def(AST_Binary, function(compressor, first_in_statement){
             var right = this.right.drop_side_effect_free(compressor);
             if (!right) return this.left.drop_side_effect_free(compressor, first_in_statement);
-            switch (this.operator) {
-              case "&&":
-              case "||":
+            if (lazy_op(this.operator)) {
                 if (right === this.right) return this;
                 var node = this.clone();
                 node.right = right;
                 return node;
-              default:
+            } 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 ]);
@@ -3526,7 +3641,7 @@ merge(Compressor.prototype, {
                     }
                     if (cdr instanceof AST_Binary && !(cdr instanceof AST_Assign)) {
                         if (cdr.left.is_constant()) {
-                            if (cdr.operator == "||" || cdr.operator == "&&") {
+                            if (lazy_op(cdr.operator)) {
                                 expressions[++i] = expressions[j];
                                 break;
                             }
@@ -3682,6 +3797,11 @@ merge(Compressor.prototype, {
     });
 
     var commutativeOperators = makePredicate("== === != !== * & | ^");
+    function is_object(node) {
+        return node instanceof AST_Array
+            || node instanceof AST_Lambda
+            || node instanceof AST_Object;
+    }
 
     OPT(AST_Binary, function(self, compressor){
         function reversible() {
@@ -3717,7 +3837,8 @@ merge(Compressor.prototype, {
           case "!==":
             if ((self.left.is_string(compressor) && self.right.is_string(compressor)) ||
                 (self.left.is_number(compressor) && self.right.is_number(compressor)) ||
-                (self.left.is_boolean() && self.right.is_boolean())) {
+                (self.left.is_boolean() && self.right.is_boolean()) ||
+                self.left.equivalent_to(self.right)) {
                 self.operator = self.operator.substr(0, 2);
             }
             // XXX: intentionally falling down to the next case
@@ -3737,6 +3858,13 @@ merge(Compressor.prototype, {
                     if (self.operator.length == 2) self.operator += "=";
                 }
             }
+            // obj !== obj => false
+            else if (self.left instanceof AST_SymbolRef
+                && self.right instanceof AST_SymbolRef
+                && self.left.definition() === self.right.definition()
+                && is_object(self.left.fixed_value())) {
+                return make_node(self.operator[0] == "=" ? AST_True : AST_False, self);
+            }
             break;
         }
         if (compressor.option("booleans") && self.operator == "+" && compressor.in_boolean_context()) {
@@ -4026,8 +4154,7 @@ merge(Compressor.prototype, {
         // "x" + (y + "z")==>  "x" + y + "z"
         if (self.right instanceof AST_Binary
             && self.right.operator == self.operator
-            && (self.operator == "&&"
-                || self.operator == "||"
+            && (lazy_op(self.operator)
                 || (self.operator == "+"
                     && (self.right.left.is_string(compressor)
                         || (self.left.is_string(compressor)
@@ -4075,12 +4202,14 @@ merge(Compressor.prototype, {
                 d.fixed = fixed = make_node(AST_Function, fixed, fixed);
             }
             if (compressor.option("unused")
-                && fixed instanceof AST_Function
+                && fixed
                 && d.references.length == 1
-                && !(d.scope.uses_arguments && d.orig[0] instanceof AST_SymbolFunarg)
-                && !d.scope.uses_eval
-                && compressor.find_parent(AST_Scope) === fixed.parent_scope) {
-                return fixed.clone(true);
+                && (d.single_use || fixed instanceof AST_Function
+                    && !(d.scope.uses_arguments && d.orig[0] instanceof AST_SymbolFunarg)
+                    && !d.scope.uses_eval
+                    && compressor.find_parent(AST_Scope) === fixed.parent_scope)) {
+                var value = fixed.optimize(compressor);
+                return value === fixed ? fixed.clone(true) : value;
             }
             if (compressor.option("evaluate") && fixed) {
                 if (d.should_replace === undefined) {
@@ -4408,19 +4537,69 @@ merge(Compressor.prototype, {
     });
 
     OPT(AST_Sub, function(self, compressor){
+        var expr = self.expression;
         var prop = self.property;
-        if (prop instanceof AST_String && compressor.option("properties")) {
-            prop = prop.getValue();
-            if (is_identifier_string(prop)) {
-                return make_node(AST_Dot, self, {
-                    expression : self.expression,
-                    property   : prop
-                }).optimize(compressor);
+        if (compressor.option("properties")) {
+            var key = prop.evaluate(compressor);
+            if (key !== prop) {
+                var property = "" + key;
+                if (is_identifier_string(property)
+                    && property.length <= prop.print_to_string().length + 1) {
+                    return make_node(AST_Dot, self, {
+                        expression: expr,
+                        property: property
+                    }).optimize(compressor);
+                }
+                if (!(prop instanceof AST_Number)) {
+                    var value = parseFloat(property);
+                    if (value.toString() == property) {
+                        prop = self.property = make_node(AST_Number, prop, {
+                            value: value
+                        });
+                    }
+                }
             }
-            var v = parseFloat(prop);
-            if (!isNaN(v) && v.toString() == prop) {
-                self.property = make_node(AST_Number, self.property, {
-                    value: v
+        }
+        if (is_lhs(self, compressor.parent())) return self;
+        if (compressor.option("properties") && key !== prop) {
+            var node = self.flatten_object(property);
+            if (node) {
+                expr = self.expression = node.expression;
+                prop = self.property = node.property;
+            }
+        }
+        if (compressor.option("properties") && compressor.option("side_effects")
+            && prop instanceof AST_Number && expr instanceof AST_Array) {
+            var index = prop.getValue();
+            var elements = expr.elements;
+            if (index in elements) {
+                var flatten = true;
+                var values = [];
+                for (var i = elements.length; --i > index;) {
+                    var value = elements[i].drop_side_effect_free(compressor);
+                    if (value) {
+                        values.unshift(value);
+                        if (flatten && value.has_side_effects(compressor)) flatten = false;
+                    }
+                }
+                var retValue = elements[index];
+                retValue = retValue instanceof AST_Hole ? make_node(AST_Undefined, retValue) : retValue;
+                if (!flatten) values.unshift(retValue);
+                while (--i >= 0) {
+                    var value = elements[i].drop_side_effect_free(compressor);
+                    if (value) values.unshift(value);
+                    else index--;
+                }
+                if (flatten) {
+                    values.push(retValue);
+                    return make_sequence(self, values).optimize(compressor);
+                } else return make_node(AST_Sub, self, {
+                    expression: make_node(AST_Array, expr, {
+                        elements: values
+                    }),
+                    property: make_node(AST_Number, prop, {
+                        value: index
+                    })
                 });
             }
         }
@@ -4443,25 +4622,38 @@ merge(Compressor.prototype, {
         return result;
     });
 
+    AST_PropAccess.DEFMETHOD("flatten_object", function(key) {
+        var expr = this.expression;
+        if (expr instanceof AST_Object) {
+            var props = expr.properties;
+            for (var i = props.length; --i >= 0;) {
+                var prop = props[i];
+                if ("" + prop.key == key) {
+                    if (!all(props, function(prop) {
+                        return prop instanceof AST_ObjectKeyVal;
+                    })) break;
+                    var value = prop.value;
+                    if (value instanceof AST_Function && value.contains_this()) break;
+                    return make_node(AST_Sub, this, {
+                        expression: make_node(AST_Array, expr, {
+                            elements: props.map(function(prop) {
+                                return prop.value;
+                            })
+                        }),
+                        property: make_node(AST_Number, this, {
+                            value: i
+                        })
+                    });
+                }
+            }
+        }
+    });
+
     OPT(AST_Dot, function(self, compressor){
         var def = self.resolve_defines(compressor);
         if (def) {
             return def.optimize(compressor);
         }
-        if (compressor.option("unsafe") && self.expression instanceof AST_Object) {
-            var values = self.expression.properties;
-            for (var i = values.length; --i >= 0;) {
-                if (values[i].key === self.property) {
-                    var value = values[i].value;
-                    if (value instanceof AST_Function ? !value.contains_this() : !value.has_side_effects(compressor)) {
-                        var obj = self.expression.clone();
-                        obj.properties = obj.properties.slice();
-                        obj.properties.splice(i, 1);
-                        return make_sequence(self, [ obj, value ]).optimize(compressor);
-                    }
-                }
-            }
-        }
         if (compressor.option("unsafe_proto")
             && self.expression instanceof AST_Dot
             && self.expression.property == "prototype") {
@@ -4484,6 +4676,11 @@ merge(Compressor.prototype, {
                 break;
             }
         }
+        if (is_lhs(self, compressor.parent())) return self;
+        if (compressor.option("properties")) {
+            var node = self.flatten_object(self.property);
+            if (node) return node.optimize(compressor);
+        }
         var ev = self.evaluate(compressor);
         if (ev !== self) {
             ev = make_node_from_constant(ev, self).optimize(compressor);

lib/parse.js

@@ -1054,6 +1054,8 @@ function parse($TEXT, options) {
         var name = is("name") ? as_symbol(in_statement ? AST_SymbolDefun : AST_SymbolLambda) : null;
         if (in_statement && !name)
             unexpected();
+        if (name && ctor !== AST_Accessor && !(name instanceof AST_SymbolDeclaration))
+            unexpected(prev());
         expect("(");
         var argnames = [];
         for (var first = true; !is("punc", ")");) {

package.json

@@ -4,7 +4,7 @@
   "homepage": "http://lisperator.net/uglifyjs",
   "author": "Mihai Bazon <mihai.bazon@gmail.com> (http://lisperator.net/)",
   "license": "BSD-2-Clause",
-  "version": "3.1.2",
+  "version": "3.1.6",
   "engines": {
     "node": ">=0.8.0"
   },
@@ -30,7 +30,7 @@
   ],
   "dependencies": {
     "commander": "~2.11.0",
-    "source-map": "~0.5.1"
+    "source-map": "~0.6.1"
   },
   "devDependencies": {
     "acorn": "~5.1.1",

test/compress/arrays.js

@@ -128,50 +128,110 @@ constant_join_3: {
 
 for_loop: {
     options = {
-        unsafe      : true,
-        unused      : true,
-        evaluate    : true,
-        reduce_vars : true
+        evaluate: true,
+        reduce_vars: true,
+        unsafe: true,
+        unused: true,
     };
     input: {
         function f0() {
             var a = [1, 2, 3];
-            for (var i = 0; i < a.length; i++) {
-                console.log(a[i]);
-            }
+            var b = 0;
+            for (var i = 0; i < a.length; i++)
+                b += a[i];
+            return b;
         }
-
         function f1() {
             var a = [1, 2, 3];
-            for (var i = 0, len = a.length; i < len; i++) {
-                console.log(a[i]);
-            }
+            var b = 0;
+            for (var i = 0, len = a.length; i < len; i++)
+                b += a[i];
+            return b;
         }
-
-        function f2() {
-            var a = [1, 2, 3];
-            for (var i = 0; i < a.length; i++) {
-                a[i]++;
-            }
-        }
-    }
-    expect: {
-        function f0() {
-            var a = [1, 2, 3];
-            for (var i = 0; i < 3; i++)
-                console.log(a[i]);
-        }
-
-        function f1() {
-            var a = [1, 2, 3];
-            for (var i = 0; i < 3; i++)
-                console.log(a[i]);
-        }
-
         function f2() {
             var a = [1, 2, 3];
             for (var i = 0; i < a.length; i++)
                 a[i]++;
+            return a[2];
         }
+        console.log(f0(), f1(), f2());
     }
+    expect: {
+        function f0() {
+            var a = [1, 2, 3];
+            var b = 0;
+            for (var i = 0; i < 3; i++)
+                b += a[i];
+            return b;
+        }
+        function f1() {
+            var a = [1, 2, 3];
+            var b = 0;
+            for (var i = 0; i < 3; i++)
+                b += a[i];
+            return b;
+        }
+        function f2() {
+            var a = [1, 2, 3];
+            for (var i = 0; i < a.length; i++)
+                a[i]++;
+            return a[2];
+        }
+        console.log(f0(), f1(), f2());
+    }
+    expect_stdout: "6 6 4"
+}
+
+index: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        toplevel: true,
+        unsafe: true,
+        unused: true,
+    }
+    input: {
+        var a = [ 1, 2 ];
+        console.log(a[0], a[1]);
+    }
+    expect: {
+        console.log(1, 2);
+    }
+    expect_stdout: "1 2"
+}
+
+length: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        toplevel: true,
+        unsafe: true,
+        unused: true,
+    }
+    input: {
+        var a = [ 1, 2 ];
+        console.log(a.length);
+    }
+    expect: {
+        console.log(2);
+    }
+    expect_stdout: "2"
+}
+
+index_length: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        toplevel: true,
+        unsafe: true,
+        unused: true,
+    }
+    input: {
+        var a = [ 1, 2 ];
+        console.log(a[0], a.length);
+    }
+    expect: {
+        console.log(1, 2);
+    }
+    expect_stdout: "1 2"
 }

test/compress/collapse_vars.js

@@ -1268,22 +1268,21 @@ collapse_vars_short_circuited_conditions: {
 
 collapse_vars_regexp: {
     options = {
-        collapse_vars: true,
-        loops:         false,
-        sequences:     true,
-        dead_code:     true,
-        conditionals:  true,
-        comparisons:   true,
-        evaluate:      true,
         booleans:      true,
-        unused:        true,
-        hoist_funs:    true,
-        keep_fargs:    true,
+        cascade:       true,
+        collapse_vars: true,
+        comparisons:   true,
+        conditionals:  true,
+        dead_code:     true,
+        evaluate:      true,
         if_return:     true,
         join_vars:     true,
-        cascade:       true,
-        side_effects:  true,
+        hoist_funs:    true,
+        keep_fargs:    true,
+        loops:         false,
         reduce_vars:   true,
+        side_effects:  true,
+        unused:        true,
     }
     input: {
         function f1() {
@@ -1292,12 +1291,12 @@ collapse_vars_regexp: {
             return [rx, k];
         }
         function f2() {
-            var rx = /[abc123]+/;
+            var rx = /ab*/g;
             return function(s) {
                 return rx.exec(s);
             };
         }
-        (function(){
+        (function() {
             var result;
             var s = 'acdabcdeabbb';
             var rx = /ab*/g;
@@ -1305,22 +1304,35 @@ collapse_vars_regexp: {
                 console.log(result[0]);
             }
         })();
+        (function() {
+            var result;
+            var s = 'acdabcdeabbb';
+            var rx = f2();
+            while (result = rx(s)) {
+                console.log(result[0]);
+            }
+        })();
     }
     expect: {
         function f1() {
             return [/[A-Z]+/, 9];
         }
         function f2() {
-            var rx = /[abc123]+/;
+            var rx = /ab*/g;
             return function(s) {
                 return rx.exec(s);
             };
         }
-        (function(){
+        (function() {
             var result, rx = /ab*/g;
             while (result = rx.exec("acdabcdeabbb"))
                 console.log(result[0]);
         })();
+        (function() {
+            var result, rx = f2();
+            while (result = rx("acdabcdeabbb"))
+                console.log(result[0]);
+        })();
     }
     expect_stdout: true
 }
@@ -1834,9 +1846,9 @@ issue_1858: {
     }
     expect: {
         console.log(function(x) {
-            var a = {}, b = a.b = x;
+            var a = {}, b = a.b = 1;
             return a.b + b;
-        }(1));
+        }());
     }
     expect_stdout: "2"
 }
@@ -2039,7 +2051,7 @@ inner_lvalues: {
         console.log(null, a, b);
     }
     expect: {
-        var a, b = 10;
+        var b = 10;
         var a = (--b || a || 3).toString(), c = --b + -a;
         console.log(null, a, b);
     }
@@ -2521,3 +2533,419 @@ issue_2319_3: {
     }
     expect_stdout: "true"
 }
+
+issue_2365: {
+    options = {
+        collapse_vars: true,
+        pure_getters: true,
+    }
+    input: {
+        console.log(function(a) {
+            var b = a.f;
+            a.f++;
+            return b;
+        }({ f: 1 }));
+        console.log(function() {
+            var a = { f: 1 }, b = a.f;
+            a.f++;
+            return b;
+        }());
+        console.log({
+            f: 1,
+            g: function() {
+                var b = this.f;
+                this.f++;
+                return b;
+            }
+        }.g());
+    }
+    expect: {
+        console.log(function(a) {
+            var b = a.f;
+            a.f++;
+            return b;
+        }({ f: 1 }));
+        console.log(function() {
+            var a = { f: 1 }, b = a.f;
+            a.f++;
+            return b;
+        }());
+        console.log({
+            f: 1,
+            g: function() {
+                var b = this.f;
+                this.f++;
+                return b;
+            }
+        }.g());
+    }
+    expect_stdout: [
+        "1",
+        "1",
+        "1",
+    ]
+}
+
+issue_2364_1: {
+    options = {
+        collapse_vars: true,
+        pure_getters: true,
+    }
+    input: {
+        function inc(obj) {
+            return obj.count++;
+        }
+        function foo() {
+            var first = arguments[0];
+            var result = inc(first);
+            return foo.amount = first.count, result;
+        }
+        var data = {
+            count: 0,
+        };
+        var answer = foo(data);
+        console.log(foo.amount, answer);
+    }
+    expect: {
+        function inc(obj) {
+            return obj.count++;
+        }
+        function foo() {
+            var first = arguments[0];
+            var result = inc(first);
+            return foo.amount = first.count, result;
+        }
+        var data = {
+            count: 0
+        };
+        var answer = foo(data);
+        console.log(foo.amount, answer);
+    }
+    expect_stdout: "1 0"
+}
+
+issue_2364_2: {
+    options = {
+        collapse_vars: true,
+        pure_getters: true,
+    }
+    input: {
+        function callValidate() {
+            var validate = compilation.validate;
+            var result = validate.apply(null, arguments);
+            return callValidate.errors = validate.errors, result;
+        }
+    }
+    expect: {
+        function callValidate() {
+            var validate = compilation.validate;
+            var result = validate.apply(null, arguments);
+            return callValidate.errors = validate.errors, result;
+        }
+    }
+}
+
+issue_2364_3: {
+    options = {
+        collapse_vars: true,
+        pure_getters: true,
+    }
+    input: {
+        function inc(obj) {
+            return obj.count++;
+        }
+        function foo(bar) {
+            var result = inc(bar);
+            return foo.amount = bar.count, result;
+        }
+        var data = {
+            count: 0,
+        };
+        var answer = foo(data);
+        console.log(foo.amount, answer);
+    }
+    expect: {
+        function inc(obj) {
+            return obj.count++;
+        }
+        function foo(bar) {
+            var result = inc(bar);
+            return foo.amount = bar.count, result;
+        }
+        var data = {
+            count: 0,
+        };
+        var answer = foo(data);
+        console.log(foo.amount, answer);
+    }
+    expect_stdout: "1 0"
+}
+
+issue_2364_4: {
+    options = {
+        collapse_vars: true,
+        pure_getters: true,
+    }
+    input: {
+        function inc(obj) {
+            return obj.count++;
+        }
+        function foo(bar, baz) {
+            var result = inc(bar);
+            return foo.amount = baz.count, result;
+        }
+        var data = {
+            count: 0,
+        };
+        var answer = foo(data, data);
+        console.log(foo.amount, answer);
+    }
+    expect: {
+        function inc(obj) {
+            return obj.count++;
+        }
+        function foo(bar, baz) {
+            var result = inc(bar);
+            return foo.amount = baz.count, result;
+        }
+        var data = {
+            count: 0,
+        };
+        var answer = foo(data, data);
+        console.log(foo.amount, answer);
+    }
+    expect_stdout: "1 0"
+}
+
+issue_2364_5: {
+    options = {
+        collapse_vars: true,
+        evaluate: true,
+        pure_getters: true,
+        properties: true,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        function f0(o, a, h) {
+            var b = 3 - a;
+            var obj = o;
+            var seven = 7;
+            var prop = 'run';
+            var t = obj[prop](b)[seven] = h;
+            return t;
+        }
+    }
+    expect: {
+        function f0(o, a, h) {
+            return o.run(3 - a)[7] = h;
+        }
+    }
+}
+
+issue_2364_6: {
+    options = {
+        collapse_vars: true,
+        pure_getters: true,
+    }
+    input: {
+        function f(a, b) {
+            var c = a.p;
+            b.p = "FAIL";
+            return c;
+        }
+        var o = {
+            p: "PASS"
+        }
+        console.log(f(o, o));
+    }
+    expect: {
+        function f(a, b) {
+            var c = a.p;
+            b.p = "FAIL";
+            return c;
+        }
+        var o = {
+            p: "PASS"
+        }
+        console.log(f(o, o));
+    }
+    expect_stdout: "PASS"
+}
+
+issue_2364_7: {
+    options = {
+        collapse_vars: true,
+        pure_getters: true,
+    }
+    input: {
+        function f(a, b) {
+            var c = a.p;
+            b.f();
+            return c;
+        }
+        var o = {
+            p: "PASS",
+            f: function() {
+                this.p = "FAIL";
+            }
+        }
+        console.log(f(o, o));
+    }
+    expect: {
+        function f(a, b) {
+            var c = a.p;
+            b.f();
+            return c;
+        }
+        var o = {
+            p: "PASS",
+            f: function() {
+                this.p = "FAIL";
+            }
+        }
+        console.log(f(o, o));
+    }
+    expect_stdout: "PASS"
+}
+
+issue_2364_8: {
+    options = {
+        collapse_vars: true,
+        pure_getters: true,
+    }
+    input: {
+        function f(a, b, c) {
+            var d = a[b.f = function() {
+                return "PASS";
+            }];
+            return c.f(d);
+        }
+        var o = {
+            f: function() {
+                return "FAIL";
+            }
+        };
+        console.log(f({}, o, o));
+    }
+    expect: {
+        function f(a, b, c) {
+            var d = a[b.f = function() {
+                return "PASS";
+            }];
+            return c.f(d);
+        }
+        var o = {
+            f: function() {
+                return "FAIL";
+            }
+        };
+        console.log(f({}, o, o));
+    }
+    expect_stdout: "PASS"
+}
+
+issue_2364_9: {
+    options = {
+        collapse_vars: true,
+        pure_getters: true,
+    }
+    input: {
+        function f(a, b) {
+            var d = a();
+            return b.f(d);
+        }
+        var o = {
+            f: function() {
+                return "FAIL";
+            }
+        };
+        console.log(f(function() {
+            o.f = function() {
+                return "PASS";
+            };
+        }, o));
+    }
+    expect: {
+        function f(a, b) {
+            var d = a();
+            return b.f(d);
+        }
+        var o = {
+            f: function() {
+                return "FAIL";
+            }
+        };
+        console.log(f(function() {
+            o.f = function() {
+                return "PASS";
+            };
+        }, o));
+    }
+    expect_stdout: "PASS"
+}
+
+pure_getters_chain: {
+    options = {
+        collapse_vars: true,
+        pure_getters: true,
+    }
+    input: {
+        function o(t, r) {
+            var a = t[1], s = t[2], o = t[3], i = t[5];
+            return a <= 23 && s <= 59 && o <= 59 && (!r || i);
+        }
+        console.log(o([ , 23, 59, 59, , 42], 1));
+    }
+    expect: {
+        function o(t, r) {
+            return t[1] <= 23 && t[2] <= 59 && t[3] <= 59 && (!r || t[5]);
+        }
+        console.log(o([ , 23, 59, 59, , 42], 1));
+    }
+    expect_stdout: "42"
+}
+
+conditional_1: {
+    options = {
+        collapse_vars: true,
+    }
+    input: {
+        function f(a, b) {
+            var c = "";
+            var d = b ? ">" : "<";
+            if (a) c += "=";
+            return c += d;
+        }
+        console.log(f(0, 0), f(0, 1), f(1, 0), f(1, 1));
+    }
+    expect: {
+        function f(a, b) {
+            var c = "";
+            if (a) c += "=";
+            return c += b ? ">" : "<";
+        }
+        console.log(f(0, 0), f(0, 1), f(1, 0), f(1, 1));
+    }
+    expect_stdout: "< > =< =>"
+}
+
+conditional_2: {
+    options = {
+        collapse_vars: true,
+    }
+    input: {
+        function f(a, b) {
+            var c = a + 1, d = a + 2;
+            return b ? c : d;
+        }
+        console.log(f(3, 0), f(4, 1));
+    }
+    expect: {
+        function f(a, b) {
+            return b ? a + 1 : a + 2;
+        }
+        console.log(f(3, 0), f(4, 1));
+    }
+    expect_stdout: "5 5"
+}

test/compress/comparing.js

@@ -73,4 +73,41 @@ dont_change_in_or_instanceof_expressions: {
         1 instanceof 1;
         null instanceof null;
     }
-}
+}
+
+self_comparison_1: {
+    options = {
+        comparisons: true,
+    }
+    input: {
+        a === a;
+        a !== b;
+        b.c === a.c;
+        b.c !== b.c;
+    }
+    expect: {
+        a == a;
+        a !== b;
+        b.c === a.c;
+        b.c != b.c;
+    }
+}
+
+self_comparison_2: {
+    options = {
+        comparisons: true,
+        reduce_vars: true,
+        toplevel: true,
+    }
+    input: {
+        function f() {}
+        var o = {};
+        console.log(f != f, o === o);
+    }
+    expect: {
+        function f() {}
+        var o = {};
+        console.log(false, true);
+    }
+    expect_stdout: "false true"
+}

test/compress/drop-unused.js

@@ -751,12 +751,12 @@ issue_1583: {
     expect: {
         function m(t) {
             (function(e) {
-                t = e();
-            })(function() {
-                return (function(a) {
-                    return a;
-                })(function(a) {});
-            });
+                t = function() {
+                    return (function(a) {
+                        return function(a) {};
+                    })();
+                }();
+            })();
         }
     }
 }

test/compress/evaluate.js

@@ -386,10 +386,11 @@ unsafe_object_accessor: {
     }
 }
 
-unsafe_function: {
+prop_function: {
     options = {
-        evaluate  : true,
-        unsafe    : true
+        evaluate: true,
+        properties: true,
+        side_effects: true,
     }
     input: {
         console.log(
@@ -402,9 +403,9 @@ unsafe_function: {
     expect: {
         console.log(
             ({a:{b:1},b:function(){}}) + 1,
-            ({b:function(){}}, {b:1}) + 1,
-            ({a:{b:1}}, function(){}) + 1,
-            ({b:function(){}}, {b:1}).b + 1
+            ({b:1}) + 1,
+            function(){} + 1,
+            2
         );
     }
     expect_stdout: true
@@ -630,10 +631,11 @@ unsafe_string_bad_index: {
     expect_stdout: true
 }
 
-unsafe_prototype_function: {
+prototype_function: {
     options = {
-        evaluate  : true,
-        unsafe    : true
+        evaluate: true,
+        properties: true,
+        side_effects: true,
     }
     input: {
         var a = ({valueOf: 0}) < 1;
@@ -652,8 +654,8 @@ unsafe_prototype_function: {
         var d = ({toString: 0}) + "";
         var e = (({valueOf: 0}) + "")[2];
         var f = (({toString: 0}) + "")[2];
-        var g = ({}, 0)();
-        var h = ({}, 0)();
+        var g = 0();
+        var h = 0();
     }
 }
 
@@ -1021,6 +1023,7 @@ issue_1964_1: {
     input: {
         function f() {
             var long_variable_name = /\s/;
+            console.log(long_variable_name.source);
             return "a b c".split(long_variable_name)[1];
         }
         console.log(f());
@@ -1028,11 +1031,15 @@ issue_1964_1: {
     expect: {
         function f() {
             var long_variable_name = /\s/;
+            console.log(long_variable_name.source);
             return "a b c".split(long_variable_name)[1];
         }
         console.log(f());
     }
-    expect_stdout: "b"
+    expect_stdout: [
+        "\\s",
+        "b",
+    ]
 }
 
 issue_1964_2: {
@@ -1045,17 +1052,22 @@ issue_1964_2: {
     input: {
         function f() {
             var long_variable_name = /\s/;
+            console.log(long_variable_name.source);
             return "a b c".split(long_variable_name)[1];
         }
         console.log(f());
     }
     expect: {
         function f() {
+            console.log(/\s/.source);
             return "a b c".split(/\s/)[1];
         }
         console.log(f());
     }
-    expect_stdout: "b"
+    expect_stdout: [
+        "\\s",
+        "b",
+    ]
 }
 
 array_slice_index: {
@@ -1185,3 +1197,40 @@ issue_2231_2: {
     }
     expect_stdout: true
 }
+
+self_comparison_1: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        toplevel: true,
+        unsafe: true,
+        unused: true,
+    }
+    input: {
+        var o = { n: NaN };
+        console.log(o.n == o.n, o.n === o.n, o.n != o.n, o.n !== o.n, typeof o.n);
+    }
+    expect: {
+        console.log(false, false, true, true, "number");
+    }
+    expect_stdout: "false false true true 'number'"
+}
+
+self_comparison_2: {
+    options = {
+        evaluate: true,
+        hoist_props: true,
+        passes: 2,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var o = { n: NaN };
+        console.log(o.n == o.n, o.n === o.n, o.n != o.n, o.n !== o.n, typeof o.n);
+    }
+    expect: {
+        console.log(false, false, true, true, "number");
+    }
+    expect_stdout: "false false true true 'number'"
+}

test/compress/functions.js

@@ -151,13 +151,13 @@ issue_1841_2: {
 
 function_returning_constant_literal: {
     options = {
-        reduce_vars: true,
-        unsafe: true,
-        toplevel: true,
-        evaluate: true,
-        cascade: true,
-        unused: true,
         inline: true,
+        passes: 2,
+        properties: true,
+        reduce_vars: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
     }
     input: {
         function greeter() {

test/compress/hoist_props.js

@@ -0,0 +1,371 @@
+issue_2377_1: {
+    options = {
+        evaluate: true,
+        inline: true,
+        hoist_props: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var obj = {
+            foo: 1,
+            bar: 2,
+            square: function(x) {
+                return x * x;
+            },
+            cube: function(x) {
+                return x * x * x;
+            },
+        };
+        console.log(obj.foo, obj.cube(3));
+    }
+    expect: {
+        var obj_foo = 1, obj_cube = function(x) {
+            return x * x * x;
+        };
+        console.log(obj_foo, obj_cube(3));
+    }
+    expect_stdout: "1 27"
+}
+
+issue_2377_2: {
+    options = {
+        evaluate: true,
+        inline: true,
+        hoist_props: true,
+        passes: 2,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var obj = {
+            foo: 1,
+            bar: 2,
+            square: function(x) {
+                return x * x;
+            },
+            cube: function(x) {
+                return x * x * x;
+            },
+        };
+        console.log(obj.foo, obj.cube(3));
+    }
+    expect: {
+        console.log(1, function(x) {
+            return x * x * x;
+        }(3));
+    }
+    expect_stdout: "1 27"
+}
+
+issue_2377_3: {
+    options = {
+        evaluate: true,
+        inline: true,
+        hoist_props: true,
+        passes: 3,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var obj = {
+            foo: 1,
+            bar: 2,
+            square: function(x) {
+                return x * x;
+            },
+            cube: function(x) {
+                return x * x * x;
+            },
+        };
+        console.log(obj.foo, obj.cube(3));
+    }
+    expect: {
+        console.log(1, 27);
+    }
+    expect_stdout: "1 27"
+}
+
+direct_access_1: {
+    options = {
+        hoist_props: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a = 0;
+        var obj = {
+            a: 1,
+            b: 2,
+        };
+        for (var k in obj) a++;
+        console.log(a, obj.a);
+    }
+    expect: {
+        var a = 0;
+        var obj = {
+            a: 1,
+            b: 2,
+        };
+        for (var k in obj) a++;
+        console.log(a, obj.a);
+    }
+    expect_stdout: "2 1"
+}
+
+direct_access_2: {
+    options = {
+        hoist_props: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var o = { a: 1 };
+        var f = function(k) {
+            if (o[k]) return "PASS";
+        };
+        console.log(f("a"));
+    }
+    expect: {
+        var o = { a: 1 };
+        console.log(function(k) {
+            if (o[k]) return "PASS";
+        }("a"));
+    }
+    expect_stdout: "PASS"
+}
+
+direct_access_3: {
+    options = {
+        hoist_props: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var o = { a: 1 };
+        o.b;
+        console.log(o.a);
+    }
+    expect: {
+        var o = { a: 1 };
+        o.b;
+        console.log(o.a);
+    }
+    expect_stdout: "1"
+}
+
+single_use: {
+    options = {
+        hoist_props: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var obj = {
+            bar: function() {
+                return 42;
+            },
+        };
+        console.log(obj.bar());
+    }
+    expect: {
+        console.log({
+            bar: function() {
+                return 42;
+            },
+        }.bar());
+    }
+}
+
+name_collision_1: {
+    options = {
+        hoist_props: true,
+        reduce_vars: true,
+        toplevel: true,
+    }
+    input: {
+        var obj_foo = 1;
+        var obj_bar = 2;
+        function f() {
+            var obj = {
+                foo: 3,
+                bar: 4,
+                "b-r": 5,
+                "b+r": 6,
+                "b!r": 7,
+            };
+            console.log(obj_foo, obj.foo, obj.bar, obj["b-r"], obj["b+r"], obj["b!r"]);
+        }
+        f();
+    }
+    expect: {
+        var obj_foo = 1;
+        var obj_bar = 2;
+        function f() {
+            var obj_foo$0 = 3,
+                obj_bar = 4,
+                obj_b_r = 5,
+                obj_b_r$0 = 6,
+                obj_b_r$1 = 7;
+            console.log(obj_foo, obj_foo$0, obj_bar, obj_b_r, obj_b_r$0, obj_b_r$1);
+        }
+        f();
+    }
+    expect_stdout: "1 3 4 5 6 7"
+}
+
+name_collision_2: {
+    options = {
+        hoist_props: true,
+        reduce_vars: true,
+        toplevel: true,
+    }
+    input: {
+        var o = {
+            p: 1,
+            0: function(x) {
+                return x;
+            },
+            1: function(x) {
+                return x + 1;
+            }
+        }, o__$0 = 2, o__$1 = 3;
+        console.log(o.p === o.p, o[0](4), o[1](5), o__$0, o__$1);
+    }
+    expect: {
+        var o_p = 1,
+            o__ = function(x) {
+                return x;
+            },
+            o__$2 = function(x) {
+                return x + 1;
+            },
+            o__$0 = 2,
+            o__$1 = 3;
+        console.log(o_p === o_p, o__(4), o__$2(5), o__$0, o__$1);
+    }
+    expect_stdout: "true 4 6 2 3"
+}
+
+name_collision_3: {
+    options = {
+        hoist_props: true,
+        reduce_vars: true,
+        toplevel: true,
+    }
+    input: {
+        var o = {
+            p: 1,
+            0: function(x) {
+                return x;
+            },
+            1: function(x) {
+                return x + 1;
+            }
+        }, o__$0 = 2, o__$1 = 3;
+        console.log(o.p === o.p, o[0](4), o[1](5));
+    }
+    expect: {
+        var o_p = 1,
+            o__ = function(x) {
+                return x;
+            },
+            o__$2 = function(x) {
+                return x + 1;
+            },
+            o__$0 = 2,
+            o__$1 = 3;
+        console.log(o_p === o_p, o__(4), o__$2(5));
+    }
+    expect_stdout: "true 4 6"
+}
+
+contains_this_1: {
+    options = {
+        evaluate: true,
+        hoist_props: true,
+        inline: true,
+        passes: 2,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var o = {
+            u: function() {
+                return this === this;
+            },
+            p: 1
+        };
+        console.log(o.p, o.p);
+    }
+    expect: {
+        console.log(1, 1);
+    }
+    expect_stdout: "1 1"
+}
+
+contains_this_2: {
+    options = {
+        evaluate: true,
+        hoist_props: true,
+        inline: true,
+        passes: 2,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var o = {
+            u: function() {
+                return this === this;
+            },
+            p: 1
+        };
+        console.log(o.p, o.p, o.u);
+    }
+    expect: {
+        console.log(1, 1, function() {
+            return this === this;
+        });
+    }
+    expect_stdout: true
+}
+
+contains_this_3: {
+    options = {
+        evaluate: true,
+        hoist_props: true,
+        inline: true,
+        passes: 2,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var o = {
+            u: function() {
+                return this === this;
+            },
+            p: 1
+        };
+        console.log(o.p, o.p, o.u());
+    }
+    expect: {
+        var o = {
+            u: function() {
+                return this === this;
+            },
+            p: 1
+        };
+        console.log(o.p, o.p, o.u());
+    }
+    expect_stdout: "1 1 true"
+}

test/compress/properties.js

@@ -1,7 +1,8 @@
 keep_properties: {
     options = {
-        properties: false
-    };
+        evaluate: true,
+        properties: false,
+    }
     input: {
         a["foo"] = "bar";
     }
@@ -12,6 +13,7 @@ keep_properties: {
 
 dot_properties: {
     options = {
+        evaluate: true,
         properties: true,
     }
     beautify = {
@@ -37,6 +39,7 @@ dot_properties: {
 
 dot_properties_es5: {
     options = {
+        evaluate: true,
         properties: true,
     }
     beautify = {
@@ -61,8 +64,8 @@ dot_properties_es5: {
 sub_properties: {
     options = {
         evaluate: true,
-        properties: true
-    };
+        properties: true,
+    }
     input: {
         a[0] = 0;
         a["0"] = 1;
@@ -81,18 +84,18 @@ sub_properties: {
         a[3.14] = 3;
         a.if = 4;
         a["foo bar"] = 5;
-        a[NaN] = 6;
-        a[null] = 7;
+        a.NaN = 6;
+        a.null = 7;
         a[void 0] = 8;
     }
 }
 
 evaluate_array_length: {
     options = {
+        evaluate: true,
         properties: true,
         unsafe: true,
-        evaluate: true
-    };
+    }
     input: {
         a = [1, 2, 3].length;
         a = [1, 2, 3].join()["len" + "gth"];
@@ -109,10 +112,10 @@ evaluate_array_length: {
 
 evaluate_string_length: {
     options = {
+        evaluate: true,
         properties: true,
         unsafe: true,
-        evaluate: true
-    };
+    }
     input: {
         a = "foo".length;
         a = ("foo" + "bar")["len" + "gth"];
@@ -151,7 +154,8 @@ mangle_properties: {
 
 mangle_unquoted_properties: {
     options = {
-        properties: false
+        evaluate: true,
+        properties: false,
     }
     mangle = {
         properties: {
@@ -249,7 +253,8 @@ mangle_debug_suffix: {
 
 mangle_debug_suffix_keep_quoted: {
     options = {
-        properties: false
+        evaluate: true,
+        properties: false,
     }
     mangle = {
         properties: {
@@ -677,8 +682,8 @@ accessor_this: {
 issue_2208_1: {
     options = {
         inline: true,
+        properties: true,
         side_effects: true,
-        unsafe: true,
     }
     input: {
         console.log({
@@ -696,8 +701,8 @@ issue_2208_1: {
 issue_2208_2: {
     options = {
         inline: true,
+        properties: true,
         side_effects: true,
-        unsafe: true,
     }
     input: {
         console.log({
@@ -721,8 +726,8 @@ issue_2208_2: {
 issue_2208_3: {
     options = {
         inline: true,
+        properties: true,
         side_effects: true,
-        unsafe: true,
     }
     input: {
         a = 42;
@@ -746,8 +751,8 @@ issue_2208_3: {
 issue_2208_4: {
     options = {
         inline: true,
+        properties: true,
         side_effects: true,
-        unsafe: true,
     }
     input: {
         function foo() {}
@@ -770,8 +775,8 @@ issue_2208_4: {
 issue_2208_5: {
     options = {
         inline: true,
+        properties: true,
         side_effects: true,
-        unsafe: true,
     }
     input: {
         console.log({
@@ -804,3 +809,200 @@ issue_2256: {
         g.keep = g.g;
     }
 }
+
+lhs_prop_1: {
+    options = {
+        evaluate: true,
+        properties: true,
+    }
+    input: {
+        console.log(++{
+            a: 1
+        }.a);
+    }
+    expect: {
+        console.log(++{
+            a: 1
+        }.a);
+    }
+    expect_stdout: "2"
+}
+
+lhs_prop_2: {
+    options = {
+        evaluate: true,
+        inline: true,
+        properties: true,
+        reduce_vars: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        [1][0] = 42;
+        (function(a) {
+            a.b = "g";
+        })("abc");
+        (function(a) {
+            a[2] = "g";
+        })("def");
+        (function(a) {
+            a[""] = "g";
+        })("ghi");
+    }
+    expect: {
+        [1][0] = 42;
+        "abc".b = "g";
+        "def"[2] = "g";
+        "ghi"[""] = "g";
+    }
+}
+
+literal_duplicate_key_side_effects: {
+    options = {
+        properties: true,
+        side_effects: true,
+    }
+    input: {
+        console.log({
+            a: "FAIL",
+            a: console.log ? "PASS" : "FAIL"
+        }.a);
+    }
+    expect: {
+        console.log(console.log ? "PASS" : "FAIL");
+    }
+    expect_stdout: "PASS"
+}
+
+prop_side_effects_1: {
+    options = {
+        evaluate: true,
+        inline: true,
+        properties: true,
+        reduce_vars: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var C = 1;
+        console.log(C);
+        var obj = {
+            bar: function() {
+                return C + C;
+            }
+        };
+        console.log(obj.bar());
+    }
+    expect: {
+        console.log(1);
+        var obj = {
+            bar: function() {
+                return 2;
+            }
+        };
+        console.log(obj.bar());
+    }
+    expect_stdout: [
+        "1",
+        "2",
+    ]
+}
+
+prop_side_effects_2: {
+    options = {
+        evaluate: true,
+        inline: true,
+        passes: 2,
+        properties: true,
+        reduce_vars: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var C = 1;
+        console.log(C);
+        var obj = {
+            "": function() {
+                return C + C;
+            }
+        };
+        console.log(obj[""]());
+    }
+    expect: {
+        console.log(1);
+        console.log(2);
+    }
+    expect_stdout: [
+        "1",
+        "2",
+    ]
+}
+
+accessor_1: {
+    options = {
+        properties: true,
+    }
+    input: {
+        console.log({
+            a: "FAIL",
+            get a() {
+                return "PASS";
+            }
+        }.a);
+    }
+    expect: {
+        console.log({
+            a: "FAIL",
+            get a() {
+                return "PASS";
+            }
+        }.a);
+    }
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}
+
+accessor_2: {
+    options = {
+        properties: true,
+    }
+    input: {
+        console.log({
+            get a() {
+                return "PASS";
+            },
+            set a(v) {},
+            a: "FAIL"
+        }.a);
+    }
+    expect: {
+        console.log({
+            get a() {
+                return "PASS";
+            },
+            set a(v) {},
+            a: "FAIL"
+        }.a);
+    }
+    expect_stdout: true
+}
+
+array_hole: {
+    options = {
+        properties: true,
+        side_effects: true,
+    }
+    input: {
+        console.log(
+            [ 1, 2, , 3][1],
+            [ 1, 2, , 3][2],
+            [ 1, 2, , 3][3]
+        );
+    }
+    expect: {
+        console.log(2, void 0, 3);
+    }
+    expect_stdout: "2 undefined 3"
+}

test/compress/reduce_vars.js

@@ -172,6 +172,7 @@ unsafe_evaluate: {
     options = {
         evaluate     : true,
         reduce_vars  : true,
+        side_effects : true,
         unsafe       : true,
         unused       : true
     }
@@ -210,7 +211,116 @@ unsafe_evaluate: {
     }
 }
 
-unsafe_evaluate_object: {
+unsafe_evaluate_side_effect_free_1: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        unsafe: true,
+        unused: true,
+    }
+    input: {
+        console.log(function(){ var o={p:1}; console.log(o.p); return o.p; }());
+        console.log(function(){ var o={p:2}; console.log(o.p); return o; }());
+        console.log(function(){ var o={p:3}; console.log([o][0].p); return o.p; }());
+    }
+    expect: {
+        console.log(function(){ console.log(1); return 1; }());
+        console.log(function(){ var o={p:2}; console.log(2); return o; }());
+        console.log(function(){ console.log(3); return 3; }());
+    }
+    expect_stdout: true
+}
+
+unsafe_evaluate_side_effect_free_2: {
+    options = {
+        collapse_vars: true,
+        evaluate: true,
+        passes: 2,
+        pure_getters: "strict",
+        reduce_vars: true,
+        unsafe: true,
+        unused: true,
+    }
+    input: {
+        console.log(function(){ var o={p:1},a=[o]; console.log(a[0].p); return o.p; }());
+    }
+    expect: {
+        console.log(function(){ console.log(1); return 1; }());
+    }
+    expect_stdout: true
+}
+
+unsafe_evaluate_escaped: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        unsafe: true,
+        unused: true,
+    }
+    input: {
+        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: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:3},a=[o]; console.log(a[0].p++); return o.p; }());
+    }
+    expect_stdout: true
+}
+
+unsafe_evaluate_modified: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        unsafe: true,
+        unused: true,
+    }
+    input: {
+        console.log(function(){ var o={p:1}; o.p++; console.log(o.p); return o.p; }());
+        console.log(function(){ var o={p:2}; --o.p; console.log(o.p); return o.p; }());
+        console.log(function(){ var o={p:3}; o.p += ""; console.log(o.p); return o.p; }());
+        console.log(function(){ var o={p:4}; o = {}; console.log(o.p); return o.p; }());
+        console.log(function(){ var o={p:5}; o.p = -9; console.log(o.p); return o.p; }());
+        function inc() { this.p++; }
+        console.log(function(){ var o={p:6}; inc.call(o); console.log(o.p); return o.p; }());
+        console.log(function(){ var o={p:7}; console.log([o][0].p++); return o.p; }());
+    }
+    expect: {
+        console.log(function(){ var o={p:1}; o.p++; console.log(o.p); return o.p; }());
+        console.log(function(){ var o={p:2}; --o.p; console.log(o.p); return o.p; }());
+        console.log(function(){ var o={p:3}; o.p += ""; console.log(o.p); return o.p; }());
+        console.log(function(){ var o={p:4}; o = {}; console.log(o.p); return o.p; }());
+        console.log(function(){ var o={p:5}; o.p = -9; console.log(o.p); return o.p; }());
+        function inc() { this.p++; }
+        console.log(function(){ var o={p:6}; inc.call(o); console.log(o.p); return o.p; }());
+        console.log(function(){ var o={p:7}; console.log([o][0].p++); return o.p; }());
+    }
+    expect_stdout: true
+}
+
+unsafe_evaluate_unknown: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        unsafe: true,
+        unused: true,
+    }
+    input: {
+        console.log(function(){ var o={p:1}; console.log(o.not_present); return o.p; }());
+        console.log(function(){ var o={p:2}; console.log(o.prototype); return o.p; }());
+        console.log(function(){ var o={p:3}; console.log(o.hasOwnProperty); return o.p; }());
+    }
+    expect: {
+        console.log(function(){ var o={p:1}; console.log(o.not_present); return o.p; }());
+        console.log(function(){ var o={p:2}; console.log(o.prototype); return o.p; }());
+        console.log(function(){ var o={p:3}; console.log(o.hasOwnProperty); return o.p; }());
+    }
+    expect_stdout: true
+}
+
+unsafe_evaluate_object_1: {
     options = {
         evaluate     : true,
         reduce_vars  : true,
@@ -250,7 +360,83 @@ unsafe_evaluate_object: {
     }
 }
 
-unsafe_evaluate_array: {
+unsafe_evaluate_object_2: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        toplevel: true,
+        unsafe: true,
+    }
+    input: {
+        var obj = {
+            foo: 1,
+            bar: 2,
+            square: function(x) {
+                return x * x;
+            },
+            cube: function(x) {
+                return x * x * x;
+            },
+        };
+        console.log(obj.foo, obj.bar, obj.square(2), obj.cube);
+    }
+    expect: {
+        var obj = {
+            foo: 1,
+            bar: 2,
+            square: function(x) {
+                return x * x;
+            },
+            cube: function(x) {
+                return x * x * x;
+            },
+        };
+        console.log(1, 2, obj.square(2), obj.cube);
+    }
+    expect_stdout: true
+}
+
+unsafe_evaluate_object_3: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        toplevel: true,
+        unsafe: true,
+    }
+    input: {
+        var obj = {
+            get foo() {
+                return 1;
+            },
+            bar: 2,
+            square: function(x) {
+                return x * x;
+            },
+            cube: function(x) {
+                return x * x * x;
+            },
+        };
+        console.log(obj.foo, obj.bar, obj.square(2), obj.cube);
+    }
+    expect: {
+        var obj = {
+            get foo() {
+                return 1;
+            },
+            bar: 2,
+            square: function(x) {
+                return x * x;
+            },
+            cube: function(x) {
+                return x * x * x;
+            },
+        };
+        console.log(obj.foo, obj.bar, obj.square(2), obj.cube);
+    }
+    expect_stdout: true
+}
+
+unsafe_evaluate_array_1: {
     options = {
         evaluate     : true,
         reduce_vars  : true,
@@ -298,6 +484,132 @@ unsafe_evaluate_array: {
     }
 }
 
+unsafe_evaluate_array_2: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        toplevel: true,
+        unsafe: true,
+    }
+    input: {
+        var arr = [
+            1,
+            2,
+            function(x) {
+                return x * x;
+            },
+            function(x) {
+                return x * x * x;
+            },
+        ];
+        console.log(arr[0], arr[1], arr[2](2), arr[3]);
+    }
+    expect: {
+        var arr = [
+            1,
+            2,
+            function(x) {
+                return x * x;
+            },
+            function(x) {
+                return x * x * x;
+            },
+        ];
+        console.log(1, 2, arr[2](2), arr[3]);
+    }
+    expect_stdout: true
+}
+
+unsafe_evaluate_array_3: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        toplevel: true,
+        unsafe: true,
+    }
+    input: {
+        var arr = [
+            1,
+            2,
+            function() {
+                return ++arr[0];
+            },
+        ];
+        console.log(arr[0], arr[1], arr[2](), arr[0]);
+    }
+    expect: {
+        var arr = [
+            1,
+            2,
+            function() {
+                return ++arr[0];
+            },
+        ];
+        console.log(arr[0], arr[1], arr[2](), arr[0]);
+    }
+    expect_stdout: "1 2 2 2"
+}
+
+unsafe_evaluate_array_4: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        toplevel: true,
+        unsafe: true,
+    }
+    input: {
+        var arr = [
+            1,
+            2,
+            function() {
+                return ++this[0];
+            },
+        ];
+        console.log(arr[0], arr[1], arr[2], arr[0]);
+    }
+    expect: {
+        var arr = [
+            1,
+            2,
+            function() {
+                return ++this[0];
+            },
+        ];
+        console.log(1, 2, arr[2], 1);
+    }
+    expect_stdout: true
+}
+
+unsafe_evaluate_array_5: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        toplevel: true,
+        unsafe: true,
+    }
+    input: {
+        var arr = [
+            1,
+            2,
+            function() {
+                return ++this[0];
+            },
+        ];
+        console.log(arr[0], arr[1], arr[2](), arr[0]);
+    }
+    expect: {
+        var arr = [
+            1,
+            2,
+            function() {
+                return ++this[0];
+            },
+        ];
+        console.log(arr[0], arr[1], arr[2](), arr[0]);
+    }
+    expect_stdout: "1 2 2 2"
+}
+
 unsafe_evaluate_equality_1: {
     options = {
         evaluate     : true,
@@ -1189,10 +1501,10 @@ defun_label: {
         !function() {
             console.log(function(a) {
                 L: {
-                    if (a) break L;
+                    if (2) break L;
                     return 1;
                 }
-            }(2));
+            }());
         }();
     }
     expect_stdout: true
@@ -1898,10 +2210,7 @@ redefine_farg_3: {
         console.log(f([]), g([]), h([]));
     }
     expect: {
-        console.log(function(a) {
-            var a;
-            return typeof a;
-        }([]), "number", "undefined");
+        console.log(typeof [], "number", "undefined");
     }
     expect_stdout: "object number undefined"
 }
@@ -2549,7 +2858,7 @@ issue_1922_2: {
     expect_stdout: "1"
 }
 
-accessor: {
+accessor_1: {
     options = {
         evaluate: true,
         reduce_vars: true,
@@ -2578,6 +2887,33 @@ accessor: {
     expect_stdout: "1 1"
 }
 
+accessor_2: {
+    options = {
+        collapse_vars: true,
+        evaluate: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var A = 1;
+        var B = {
+            get c() {
+                console.log(A);
+            }
+        };
+        B.c;
+    }
+    expect: {
+        ({
+            get c() {
+                console.log(1);
+            }
+        }).c;
+    }
+    expect_stdout: "1"
+}
+
 for_in_prop: {
     options = {
         reduce_vars: true,
@@ -2602,3 +2938,360 @@ for_in_prop: {
     }
     expect_stdout: "1"
 }
+
+obj_var_1: {
+    options = {
+        evaluate: true,
+        passes: 2,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var C = 1;
+        var obj = {
+            bar: function() {
+                return C + C;
+            }
+        };
+        console.log(obj.bar());
+    }
+    expect: {
+        console.log({
+            bar: function() {
+                return 2;
+            }
+        }.bar());
+    }
+    expect_stdout: "2"
+}
+
+obj_var_2: {
+    options = {
+        evaluate: true,
+        inline: true,
+        passes: 2,
+        properties: true,
+        reduce_vars: true,
+        side_effects: true,
+        toplevel: true,
+        unsafe: true,
+        unused: true,
+    }
+    input: {
+        var C = 1;
+        var obj = {
+            bar: function() {
+                return C + C;
+            }
+        };
+        console.log(obj.bar());
+    }
+    expect: {
+        console.log(2);
+    }
+    expect_stdout: "2"
+}
+
+obj_arg_1: {
+    options = {
+        evaluate: true,
+        inline: true,
+        passes: 2,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var C = 1;
+        function f(obj) {
+            return obj.bar();
+        }
+        console.log(f({
+            bar: function() {
+                return C + C;
+            }
+        }));
+    }
+    expect: {
+        console.log({
+            bar: function() {
+                return 2;
+            }
+        }.bar());
+    }
+    expect_stdout: "2"
+}
+
+obj_arg_2: {
+    options = {
+        evaluate: true,
+        inline: true,
+        passes: 2,
+        properties: true,
+        reduce_vars: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var C = 1;
+        function f(obj) {
+            return obj.bar();
+        }
+        console.log(f({
+            bar: function() {
+                return C + C;
+            }
+        }));
+    }
+    expect: {
+        console.log(2);
+    }
+    expect_stdout: "2"
+}
+
+func_arg_1: {
+    options = {
+        evaluate: true,
+        inline: true,
+        passes: 2,
+        reduce_vars: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a = 42;
+        !function(a) {
+            console.log(a());
+        }(function() {
+            return a;
+        });
+    }
+    expect: {
+        console.log(42);
+    }
+    expect_stdout: "42"
+}
+
+func_arg_2: {
+    options = {
+        evaluate: true,
+        inline: true,
+        passes: 2,
+        reduce_vars: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a = 42;
+        !function(a) {
+            console.log(a());
+        }(function(a) {
+            return a;
+        });
+    }
+    expect: {
+        console.log(void 0);
+    }
+    expect_stdout: "undefined"
+}
+
+regex_loop: {
+    options = {
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        function f(x) {
+            for (var r, s = "acdabcdeabbb"; r = x().exec(s);)
+                console.log(r[0]);
+        }
+        var a = /ab*/g;
+        f(function() {
+            return a;
+        });
+    }
+    expect: {
+        var a = /ab*/g;
+        (function(x) {
+            for (var r, s = "acdabcdeabbb"; r = x().exec(s);)
+                console.log(r[0]);
+        })(function() {
+            return a;
+        });
+    }
+    expect_stdout: true
+}
+
+obj_for_1: {
+    options = {
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var o = { a: 1 };
+        for (var i = o.a--; i; i--)
+            console.log(i);
+    }
+    expect: {
+        for (var i = { a: 1 }.a--; i; i--)
+            console.log(i);
+    }
+    expect_stdout: "1"
+}
+
+obj_for_2: {
+    options = {
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var o = { a: 1 };
+        for (var i; i = o.a--;)
+            console.log(i);
+    }
+    expect: {
+        var o = { a: 1 };
+        for (var i; i = o.a--;)
+            console.log(i);
+    }
+    expect_stdout: "1"
+}
+
+array_forin_1: {
+    options = {
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a = [ 1, 2, 3 ];
+        for (var b in a)
+            console.log(b);
+    }
+    expect: {
+        for (var b in [ 1, 2, 3 ])
+            console.log(b);
+    }
+    expect_stdout: [
+        "0",
+        "1",
+        "2",
+    ]
+}
+
+array_forin_2: {
+    options = {
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a = [];
+        for (var b in [ 1, 2, 3 ])
+            a.push(b);
+        console.log(a.length);
+    }
+    expect: {
+        var a = [];
+        for (var b in [ 1, 2, 3 ])
+            a.push(b);
+        console.log(a.length);
+    }
+    expect_stdout: "3"
+}
+
+const_expr_1: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        toplevel: true,
+        unsafe: true,
+        unused: true,
+    }
+    input: {
+        var o = {
+            a: 1,
+            b: 2
+        };
+        o.a++;
+        console.log(o.a, o.b);
+    }
+    expect: {
+        var o = {
+            a: 1,
+            b: 2
+        };
+        o.a++;
+        console.log(o.a, o.b);
+    }
+    expect_stdout: "2 2"
+}
+
+const_expr_2: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        toplevel: true,
+        unsafe: true,
+        unused: true,
+    }
+    input: {
+        Object.prototype.c = function() {
+            this.a++;
+        };
+        var o = {
+            a: 1,
+            b: 2
+        };
+        o.c();
+        console.log(o.a, o.b);
+    }
+    expect: {
+        Object.prototype.c = function() {
+            this.a++;
+        };
+        var o = {
+            a: 1,
+            b: 2
+        };
+        o.c();
+        console.log(o.a, o.b);
+    }
+    expect_stdout: "2 2"
+}
+
+escaped_prop: {
+    options = {
+        collapse_vars: true,
+        evaluate: true,
+        inline: true,
+        pure_getters: "strict",
+        reduce_vars: true,
+        side_effects: true,
+        toplevel: true,
+        unsafe: true,
+        unused: true,
+    }
+    input: {
+        var obj = { o: { a: 1 } };
+        (function(o) {
+            o.a++;
+        })(obj.o);
+        (function(o) {
+            console.log(o.a);
+        })(obj.o);
+    }
+    expect: {
+        var obj = { o: { a: 1 } };
+        obj.o.a++;
+        console.log(obj.o.a);
+    }
+    expect_stdout: "2"
+}

test/mocha/minify.js

@@ -73,6 +73,12 @@ describe("minify", function() {
         assert.strictEqual(run_code(compressed), run_code(original));
     });
 
+    it("should not parse invalid use of reserved words", function() {
+        assert.strictEqual(Uglify.minify("function enum(){}").error, undefined);
+        assert.strictEqual(Uglify.minify("function static(){}").error, undefined);
+        assert.strictEqual(Uglify.minify("function this(){}").error.message, "Unexpected token: name (this)");
+    });
+
     describe("keep_quoted_props", function() {
         it("Should preserve quotes in object literals", function() {
             var js = 'var foo = {"x": 1, y: 2, \'z\': 3};';

test/ufuzz.json

@@ -16,11 +16,9 @@
     {},
     {
         "compress": {
-            "toplevel": true
+            "hoist_props": true
         },
-        "mangle": {
-            "toplevel": true
-        }
+        "toplevel": true
     },
     {
         "compress": {