v2.4.23

Fix #714

.gitignore

@@ -1,2 +1,3 @@
+/node_modules/
+/npm-debug.log
 tmp/
-node_modules/

.travis.yml

@@ -1,6 +1,10 @@
 language: node_js
 before_install: "npm install -g npm"
 node_js:
-    - "0.8"
+    - "iojs"
-    - "0.10"
+    - "0.12"
     - "0.11"
+    - "0.10"
+matrix:
+  fast_finish: true
+sudo: false

README.md

@@ -52,70 +52,87 @@ a double dash to prevent input files being used as option arguments:
 The available options are:
 
 ```
-  --source-map       Specify an output file where to generate source map.
+  --source-map                  Specify an output file where to generate source
-                                                                        [string]
+                                map.
-  --source-map-root  The path to the original source to be included in the
+  --source-map-root             The path to the original source to be included
-                     source map.                                        [string]
+                                in the source map.
-  --source-map-url   The path to the source map to be added in //#
+  --source-map-url              The path to the source map to be added in //#
-                     sourceMappingURL.  Defaults to the value passed with
+                                sourceMappingURL.  Defaults to the value passed
-                     --source-map.                                      [string]
+                                with --source-map.
-  --source-map-include-sources
+  --source-map-include-sources  Pass this flag if you want to include the
-                     Pass this flag if you want to include the content of
+                                content of source files in the source map as
-                     source files in the source map as sourcesContent
+                                sourcesContent property.
-                     property.                                         [boolean]
+  --in-source-map               Input source map, useful if you're compressing
-  --in-source-map    Input source map, useful if you're compressing JS that was
+                                JS that was generated from some other original
-                     generated from some other original code.
+                                code.
-  --screw-ie8        Pass this flag if you don't care about full compliance
+  --screw-ie8                   Pass this flag if you don't care about full
-                     with Internet Explorer 6-8 quirks (by default UglifyJS
+                                compliance with Internet Explorer 6-8 quirks
-                     will try to be IE-proof).                         [boolean]
+                                (by default UglifyJS will try to be IE-proof).
-  --expr             Parse a single expression, rather than a program (for
+  --expr                        Parse a single expression, rather than a
-                     parsing JSON)                                     [boolean]
+                                program (for parsing JSON)
-  -p, --prefix       Skip prefix for original filenames that appear in source
+  -p, --prefix                  Skip prefix for original filenames that appear
-                     maps. For example -p 3 will drop 3 directories from file
+                                in source maps. For example -p 3 will drop 3
-                     names and ensure they are relative paths. You can also
+                                directories from file names and ensure they are
-                     specify -p relative, which will make UglifyJS figure out
+                                relative paths. You can also specify -p
-                     itself the relative paths between original sources, the
+                                relative, which will make UglifyJS figure out
-                     source map and the output file.                    [string]
+                                itself the relative paths between original
-  -o, --output       Output file (default STDOUT).
+                                sources, the source map and the output file.
-  -b, --beautify     Beautify output/specify output options.            [string]
+  -o, --output                  Output file (default STDOUT).
-  -m, --mangle       Mangle names/pass mangler options.                 [string]
+  -b, --beautify                Beautify output/specify output options.
-  -r, --reserved     Reserved names to exclude from mangling.
+  -m, --mangle                  Mangle names/pass mangler options.
-  -c, --compress     Enable compressor/pass compressor options. Pass options
+  -r, --reserved                Reserved names to exclude from mangling.
-                     like -c hoist_vars=false,if_return=false. Use -c with no
+  -c, --compress                Enable compressor/pass compressor options. Pass
-                     argument to use the default compression options.   [string]
+                                options like -c
-  -d, --define       Global definitions                                 [string]
+                                hoist_vars=false,if_return=false. Use -c with
-  -e, --enclose      Embed everything in a big function, with a configurable
+                                no argument to use the default compression
-                     parameter/argument list.                           [string]
+                                options.
-  --comments         Preserve copyright comments in the output. By default this
+  -d, --define                  Global definitions
-                     works like Google Closure, keeping JSDoc-style comments
+  -e, --enclose                 Embed everything in a big function, with a
-                     that contain "@license" or "@preserve". You can optionally
+                                configurable parameter/argument list.
-                     pass one of the following arguments to this flag:
+  --comments                    Preserve copyright comments in the output. By
-                     - "all" to keep all comments
+                                default this works like Google Closure, keeping
-                     - a valid JS regexp (needs to start with a slash) to keep
+                                JSDoc-style comments that contain "@license" or
-                     only comments that match.
+                                "@preserve". You can optionally pass one of the
-                     Note that currently not *all* comments can be kept when
+                                following arguments to this flag:
-                     compression is on, because of dead code removal or
+                                - "all" to keep all comments
-                     cascading statements into sequences.               [string]
+                                - a valid JS regexp (needs to start with a
-  --preamble         Preamble to prepend to the output.  You can use this to
+                                slash) to keep only comments that match.
-                     insert a comment, for example for licensing information.
+                                Note that currently not *all* comments can be
-                     This will not be parsed, but the source map will adjust
+                                kept when compression is on, because of dead
-                     for its presence.
+                                code removal or cascading statements into
-  --stats            Display operations run time on STDERR.            [boolean]
+                                sequences.
-  --acorn            Use Acorn for parsing.                            [boolean]
+  --preamble                    Preamble to prepend to the output.  You can use
-  --spidermonkey     Assume input files are SpiderMonkey AST format (as JSON).
+                                this to insert a comment, for example for
-                                                                       [boolean]
+                                licensing information.  This will not be
-  --self             Build itself (UglifyJS2) as a library (implies
+                                parsed, but the source map will adjust for its
-                     --wrap=UglifyJS --export-all)                     [boolean]
+                                presence.
-  --wrap             Embed everything in a big function, making the “exports”
+  --stats                       Display operations run time on STDERR.
-                     and “global” variables available. You need to pass an
+  --acorn                       Use Acorn for parsing.
-                     argument to this option to specify the name that your
+  --spidermonkey                Assume input files are SpiderMonkey AST format
-                     module will take when included in, say, a browser.
+                                (as JSON).
-                                                                        [string]
+  --self                        Build itself (UglifyJS2) as a library (implies
-  --export-all       Only used when --wrap, this tells UglifyJS to add code to
+                                --wrap=UglifyJS --export-all)
-                     automatically export all globals.                 [boolean]
+  --wrap                        Embed everything in a big function, making the
-  --lint             Display some scope warnings                       [boolean]
+                                “exports” and “global” variables available. You
-  -v, --verbose      Verbose                                           [boolean]
+                                need to pass an argument to this option to
-  -V, --version      Print version number and exit.                    [boolean]
+                                specify the name that your module will take
+                                when included in, say, a browser.
+  --export-all                  Only used when --wrap, this tells UglifyJS to
+                                add code to automatically export all globals.
+  --lint                        Display some scope warnings
+  -v, --verbose                 Verbose
+  -V, --version                 Print version number and exit.
+  --noerr                       Don't throw an error for unknown options in -c,
+                                -b or -m.
+  --bare-returns                Allow return outside of functions.  Useful when
+                                minifying CommonJS modules.
+  --keep-fnames                 Do not mangle/drop function names.  Useful for
+                                code relying on Function.prototype.name.
+  --reserved-file               File containing reserved names
+  --reserve-domprops            Make (most?) DOM properties reserved for
+                                --mangle-props
+  --mangle-props                Mangle property names
+  --name-cache                  File to hold mangled names mappings
 ```
 
 Specify `--output` (`-o`) to declare the output file.  Otherwise the output
@@ -189,6 +206,69 @@ comma-separated list of names.  For example:
 
 to prevent the `require`, `exports` and `$` names from being changed.
 
+### Mangling property names (`--mangle-props`)
+
+**Note:** this will probably break your code.  Mangling property names is a
+separate step, different from variable name mangling.  Pass
+`--mangle-props`.  It will mangle all properties that are seen in some
+object literal, or that are assigned to.  For example:
+
+```js
+var x = {
+  foo: 1
+};
+
+x.bar = 2;
+x["baz"] = 3;
+x[condition ? "moo" : "boo"] = 4;
+console.log(x.something());
+```
+
+In the above code, `foo`, `bar`, `baz`, `moo` and `boo` will be replaced
+with single characters, while `something()` will be left as is.
+
+In order for this to be of any use, we should avoid mangling standard JS
+names.  For instance, if your code would contain `x.length = 10`, then
+`length` becomes a candidate for mangling and it will be mangled throughout
+the code, regardless if it's being used as part of your own objects or
+accessing an array's length.  To avoid that, you can use `--reserved-file`
+to pass a filename that should contain the names to be excluded from
+mangling.  This file can be used both for excluding variable names and
+property names.  It could look like this, for example:
+
+```js
+{
+  "vars": [ "define", "require", ... ],
+  "props": [ "length", "prototype", ... ]
+}
+```
+
+`--reserved-file` can be an array of file names (either a single
+comma-separated argument, or you can pass multiple `--reserved-file`
+arguments) — in this case it will exclude names from all those files.
+
+A default exclusion file is provided in `tools/domprops.json` which should
+cover most standard JS and DOM properties defined in various browsers.  Pass
+`--reserve-domprops` to read that in.
+
+When you compress multiple files using this option, in order for them to
+work together in the end we need to ensure somehow that one property gets
+mangled to the same name in all of them.  For this, pass `--name-cache
+filename.json` and UglifyJS will maintain these mappings in a file which can
+then be reused.  It should be initially empty.  Example:
+
+```
+rm -f /tmp/cache.json  # start fresh
+uglifyjs file1.js file2.js --mangle-props --name-cache /tmp/cache.json -o part1.js
+uglifyjs file3.js file4.js --mangle-props --name-cache /tmp/cache.json -o part2.js
+```
+
+Now, `part1.js` and `part2.js` will be consistent with each other in terms
+of mangled property names.
+
+Using the name cache is not necessary if you compress all your files in a
+single call to UglifyJS.
+
 ## Compressor options
 
 You need to pass `--compress` (`-c`) to enable the compressor.  Optionally
@@ -272,14 +352,15 @@ contrived cases, but should be fine for most code.  You might want to try it
 on your own code, it should reduce the minified size.  Here's what happens
 when this flag is on:
 
-- `new Array(1, 2, 3)` or `Array(1, 2, 3)` → `[1, 2, 3 ]`
+- `new Array(1, 2, 3)` or `Array(1, 2, 3)` → `[ 1, 2, 3 ]`
 - `new Object()` → `{}`
 - `String(exp)` or `exp.toString()` → `"" + exp`
 - `new Object/RegExp/Function/Error/Array (...)` → we discard the `new`
 - `typeof foo == "undefined"` → `foo === void 0`
 - `void 0` → `undefined` (if there is a variable named "undefined" in
   scope; we do it because the variable name will be mangled, typically
-  reduced to a single character).
+  reduced to a single character)
+- discards unused function arguments (affects `function.length`)
 
 ### Conditional compilation
 
@@ -510,6 +591,16 @@ var result = UglifyJS.minify("compiled.js", {
 // same as before, it returns `code` and `map`
 ```
 
+If your input source map is not in a file, you can pass it in as an object
+using the `inSourceMap` argument:
+
+```javascript
+var result = UglifyJS.minify("compiled.js", {
+	inSourceMap: JSON.parse(my_source_map_string),
+	outSourceMap: "minified.js.map"
+});
+```
+
 The `inSourceMap` is only used if you also request `outSourceMap` (it makes
 no sense otherwise).
 

bin/extract-props.js

@@ -0,0 +1,77 @@
+#! /usr/bin/env node
+
+"use strict";
+
+var U2 = require("../tools/node");
+var fs = require("fs");
+var yargs = require("yargs");
+var ARGS = yargs
+    .describe("o", "Output file")
+    .argv;
+var files = ARGS._.slice();
+var output = {
+    vars: {},
+    props: {}
+};
+
+if (ARGS.o) try {
+    output = JSON.parse(fs.readFileSync(ARGS.o, "utf8"));
+} catch(ex) {}
+
+files.forEach(getProps);
+
+if (ARGS.o) {
+    fs.writeFileSync(ARGS.o, JSON.stringify(output, null, 2), "utf8");
+} else {
+    console.log("%s", JSON.stringify(output, null, 2));
+}
+
+function getProps(filename) {
+    var code = fs.readFileSync(filename, "utf8");
+    var ast = U2.parse(code);
+
+    ast.walk(new U2.TreeWalker(function(node){
+        if (node instanceof U2.AST_ObjectKeyVal) {
+            add(node.key);
+        }
+        else if (node instanceof U2.AST_ObjectProperty) {
+            add(node.key.name);
+        }
+        else if (node instanceof U2.AST_Dot) {
+            add(node.property);
+        }
+        else if (node instanceof U2.AST_Sub) {
+            addStrings(node.property);
+        }
+    }));
+
+    function addStrings(node) {
+        var out = {};
+        try {
+            (function walk(node){
+                node.walk(new U2.TreeWalker(function(node){
+                    if (node instanceof U2.AST_Seq) {
+                        walk(node.cdr);
+                        return true;
+                    }
+                    if (node instanceof U2.AST_String) {
+                        add(node.value);
+                        return true;
+                    }
+                    if (node instanceof U2.AST_Conditional) {
+                        walk(node.consequent);
+                        walk(node.alternative);
+                        return true;
+                    }
+                    throw out;
+                }));
+            })(node);
+        } catch(ex) {
+            if (ex !== out) throw ex;
+        }
+    }
+
+    function add(name) {
+        output.props[name] = true;
+    }
+}

bin/uglifyjs

@@ -67,6 +67,10 @@ You need to pass an argument to this option to specify the name that your module
     .describe("bare-returns", "Allow return outside of functions.  Useful when minifying CommonJS modules.")
     .describe("keep-fnames", "Do not mangle/drop function names.  Useful for code relying on Function.prototype.name.")
     .describe("quotes", "Quote style (0 - auto, 1 - single, 2 - double, 3 - original)")
+    .describe("reserved-file", "File containing reserved names")
+    .describe("reserve-domprops", "Make (most?) DOM properties reserved for --mangle-props")
+    .describe("mangle-props", "Mangle property names")
+    .describe("name-cache", "File to hold mangled names mappings")
 
     .alias("p", "prefix")
     .alias("o", "output")
@@ -84,13 +88,21 @@ You need to pass an argument to this option to specify the name that your module
     .string("source-map-root")
     .string("source-map-url")
     .string("b")
+    .string("beautify")
     .string("m")
+    .string("mangle")
     .string("c")
+    .string("compress")
     .string("d")
+    .string("define")
     .string("e")
+    .string("enclose")
     .string("comments")
     .string("wrap")
     .string("p")
+    .string("prefix")
+    .string("name-cache")
+    .array("reserved-file")
 
     .boolean("expr")
     .boolean("source-map-include-sources")
@@ -98,14 +110,18 @@ You need to pass an argument to this option to specify the name that your module
     .boolean("export-all")
     .boolean("self")
     .boolean("v")
+    .boolean("verbose")
     .boolean("stats")
     .boolean("acorn")
     .boolean("spidermonkey")
     .boolean("lint")
     .boolean("V")
+    .boolean("version")
     .boolean("noerr")
     .boolean("bare-returns")
     .boolean("keep-fnames")
+    .boolean("mangle-props")
+    .boolean("reserve-domprops")
 
     .wrap(80)
 
@@ -116,24 +132,24 @@ normalize(ARGS);
 
 if (ARGS.noerr) {
     UglifyJS.DefaultsError.croak = function(msg, defs) {
-        sys.error("WARN: " + msg);
+        print_error("WARN: " + msg);
     };
 }
 
 if (ARGS.version || ARGS.V) {
     var json = require("../package.json");
-    sys.puts(json.name + ' ' + json.version);
+    print(json.name + ' ' + json.version);
     process.exit(0);
 }
 
 if (ARGS.ast_help) {
     var desc = UglifyJS.describe_ast();
-    sys.puts(typeof desc == "string" ? desc : JSON.stringify(desc, null, 2));
+    print(typeof desc == "string" ? desc : JSON.stringify(desc, null, 2));
     process.exit(0);
 }
 
 if (ARGS.h || ARGS.help) {
-    sys.puts(yargs.help());
+    print(yargs.help());
     process.exit(0);
 }
 
@@ -144,6 +160,15 @@ if (ARGS.acorn) {
 var COMPRESS = getOptions("c", true);
 var MANGLE = getOptions("m", true);
 var BEAUTIFY = getOptions("b", true);
+var RESERVED = null;
+
+if (ARGS.reserved_file) ARGS.reserved_file.forEach(function(filename){
+    RESERVED = UglifyJS.readReservedFile(filename, RESERVED);
+});
+
+if (ARGS.reserve_domprops) {
+    RESERVED = UglifyJS.readDefaultReservedFile(RESERVED);
+}
 
 if (ARGS.d) {
     if (COMPRESS) COMPRESS.global_defs = getOptions("d");
@@ -153,6 +178,19 @@ if (ARGS.r) {
     if (MANGLE) MANGLE.except = ARGS.r.replace(/^\s+|\s+$/g).split(/\s*,+\s*/);
 }
 
+if (RESERVED && MANGLE) {
+    if (!MANGLE.except) MANGLE.except = RESERVED.vars;
+    else MANGLE.except = MANGLE.except.concat(RESERVED.vars);
+}
+
+function readNameCache(key) {
+    return UglifyJS.readNameCache(ARGS.name_cache, key);
+}
+
+function writeNameCache(key, cache) {
+    return UglifyJS.writeNameCache(ARGS.name_cache, key, cache);
+}
+
 if (ARGS.quotes === true) {
     ARGS.quotes = 3;
 }
@@ -177,13 +215,13 @@ if (ARGS.keep_fnames) {
 if (BEAUTIFY)
     UglifyJS.merge(OUTPUT_OPTIONS, BEAUTIFY);
 
-if (ARGS.comments) {
+if (ARGS.comments != null) {
     if (/^\/.*\/[a-zA-Z]*$/.test(ARGS.comments)) {
         var regex_pos = ARGS.comments.lastIndexOf("/");
         try {
             OUTPUT_OPTIONS.comments = new RegExp(ARGS.comments.substr(1, regex_pos - 1), ARGS.comments.substr(regex_pos + 1));
         } catch (e) {
-            sys.error("ERROR: Invalid --comments: " + e.message);
+            print_error("ERROR: Invalid --comments: " + e.message);
         }
     } else if (ARGS.comments == "all") {
         OUTPUT_OPTIONS.comments = true;
@@ -203,7 +241,7 @@ var files = ARGS._.slice();
 
 if (ARGS.self) {
     if (files.length > 0) {
-        sys.error("WARN: Ignoring input files since --self was passed");
+        print_error("WARN: Ignoring input files since --self was passed");
     }
     files = UglifyJS.FILES;
     if (!ARGS.wrap) ARGS.wrap = "UglifyJS";
@@ -215,7 +253,7 @@ var ORIG_MAP = ARGS.in_source_map;
 if (ORIG_MAP) {
     ORIG_MAP = JSON.parse(fs.readFileSync(ORIG_MAP));
     if (files.length == 0) {
-        sys.error("INFO: Using file from the input source map: " + ORIG_MAP.file);
+        print_error("INFO: Using file from the input source map: " + ORIG_MAP.file);
         files = [ ORIG_MAP.file ];
     }
     if (ARGS.source_map_root == null) {
@@ -228,12 +266,12 @@ if (files.length == 0) {
 }
 
 if (files.indexOf("-") >= 0 && ARGS.source_map) {
-    sys.error("ERROR: Source map doesn't work with input from STDIN");
+    print_error("ERROR: Source map doesn't work with input from STDIN");
     process.exit(1);
 }
 
 if (files.filter(function(el){ return el == "-" }).length > 1) {
-    sys.error("ERROR: Can read a single file from STDIN (two or more dashes specified)");
+    print_error("ERROR: Can read a single file from STDIN (two or more dashes specified)");
     process.exit(1);
 }
 
@@ -256,9 +294,9 @@ try {
     var compressor = COMPRESS && UglifyJS.Compressor(COMPRESS);
 } catch(ex) {
     if (ex instanceof UglifyJS.DefaultsError) {
-        sys.error(ex.msg);
+        print_error(ex.msg);
-        sys.error("Supported options:");
+        print_error("Supported options:");
-        sys.error(sys.inspect(ex.defs));
+        print_error(sys.inspect(ex.defs));
         process.exit(1);
     }
 }
@@ -266,7 +304,7 @@ try {
 async.eachLimit(files, 1, function (file, cb) {
     read_whole_file(file, function (err, code) {
         if (err) {
-            sys.error("ERROR: can't read file: " + file);
+            print_error("ERROR: can't read file: " + file);
             process.exit(1);
         }
         if (ARGS.p != null) {
@@ -303,9 +341,9 @@ async.eachLimit(files, 1, function (file, cb) {
                     });
                 } catch(ex) {
                     if (ex instanceof UglifyJS.JS_Parse_Error) {
-                        sys.error("Parse error at " + file + ":" + ex.line + "," + ex.col);
+                        print_error("Parse error at " + file + ":" + ex.line + "," + ex.col);
-                        sys.error(ex.message);
+                        print_error(ex.message);
-                        sys.error(ex.stack);
+                        print_error(ex.stack);
                         process.exit(1);
                     }
                     throw ex;
@@ -319,11 +357,11 @@ async.eachLimit(files, 1, function (file, cb) {
         TOPLEVEL = UglifyJS.AST_Node.from_mozilla_ast(TOPLEVEL);
     });
 
-    if (ARGS.wrap) {
+    if (ARGS.wrap != null) {
         TOPLEVEL = TOPLEVEL.wrap_commonjs(ARGS.wrap, ARGS.export_all);
     }
 
-    if (ARGS.enclose) {
+    if (ARGS.enclose != null) {
         var arg_parameter_list = ARGS.enclose;
         if (arg_parameter_list === true) {
             arg_parameter_list = [];
@@ -334,11 +372,23 @@ async.eachLimit(files, 1, function (file, cb) {
         TOPLEVEL = TOPLEVEL.wrap_enclose(arg_parameter_list);
     }
 
+    if (ARGS.mangle_props || ARGS.name_cache) (function(){
+        var reserved = RESERVED ? RESERVED.props : null;
+        var cache = readNameCache("props");
+        TOPLEVEL = UglifyJS.mangle_properties(TOPLEVEL, {
+            reserved   : reserved,
+            cache      : cache,
+            only_cache : !ARGS.mangle_props
+        });
+        writeNameCache("props", cache);
+    })();
+
     var SCOPE_IS_NEEDED = COMPRESS || MANGLE || ARGS.lint;
+    var TL_CACHE = readNameCache("vars");
 
     if (SCOPE_IS_NEEDED) {
         time_it("scope", function(){
-            TOPLEVEL.figure_out_scope({ screw_ie8: ARGS.screw_ie8 });
+            TOPLEVEL.figure_out_scope({ screw_ie8: ARGS.screw_ie8, cache: TL_CACHE });
             if (ARGS.lint) {
                 TOPLEVEL.scope_warnings();
             }
@@ -353,17 +403,20 @@ async.eachLimit(files, 1, function (file, cb) {
 
     if (SCOPE_IS_NEEDED) {
         time_it("scope", function(){
-            TOPLEVEL.figure_out_scope({ screw_ie8: ARGS.screw_ie8 });
+            TOPLEVEL.figure_out_scope({ screw_ie8: ARGS.screw_ie8, cache: TL_CACHE });
-            if (MANGLE) {
+            if (MANGLE && !TL_CACHE) {
                 TOPLEVEL.compute_char_frequency(MANGLE);
             }
         });
     }
 
     if (MANGLE) time_it("mangle", function(){
+        MANGLE.cache = TL_CACHE;
         TOPLEVEL.mangle_names(MANGLE);
     });
 
+    writeNameCache("vars", TL_CACHE);
+
     if (ARGS.source_map_include_sources) {
         for (var file in SOURCES_CONTENT) {
             if (SOURCES_CONTENT.hasOwnProperty(file)) {
@@ -391,15 +444,15 @@ async.eachLimit(files, 1, function (file, cb) {
     if (OUTPUT_FILE) {
         fs.writeFileSync(OUTPUT_FILE, output, "utf8");
     } else {
-        sys.print(output);
+        print(output);
     }
 
     if (ARGS.stats) {
-        sys.error(UglifyJS.string_template("Timing information (compressed {count} files):", {
+        print_error(UglifyJS.string_template("Timing information (compressed {count} files):", {
             count: files.length
         }));
         for (var i in STATS) if (STATS.hasOwnProperty(i)) {
-            sys.error(UglifyJS.string_template("- {name}: {time}s", {
+            print_error(UglifyJS.string_template("- {name}: {time}s", {
                 name: i,
                 time: (STATS[i] / 1000).toFixed(3)
             }));
@@ -418,15 +471,15 @@ function normalize(o) {
 
 function getOptions(x, constants) {
     x = ARGS[x];
-    if (!x) return null;
+    if (x == null) return null;
     var ret = {};
-    if (x !== true) {
+    if (x !== "") {
         var ast;
         try {
             ast = UglifyJS.parse(x, { expression: true });
         } catch(ex) {
             if (ex instanceof UglifyJS.JS_Parse_Error) {
-                sys.error("Error parsing arguments in: " + x);
+                print_error("Error parsing arguments in: " + x);
                 process.exit(1);
             }
         }
@@ -445,8 +498,8 @@ function getOptions(x, constants) {
                 ret[name] = true;
                 return true;    // no descend
             }
-            sys.error(node.TYPE)
+            print_error(node.TYPE)
-            sys.error("Error parsing arguments in: " + x);
+            print_error("Error parsing arguments in: " + x);
             process.exit(1);
         }));
     }
@@ -478,3 +531,11 @@ function time_it(name, cont) {
     }
     return ret;
 }
+
+function print_error(msg) {
+    console.error("%s", msg);
+}
+
+function print(txt) {
+    console.log("%s", txt);
+}

lib/compress.js

@@ -489,7 +489,7 @@ merge(Compressor.prototype, {
                 seq = [];
             };
             statements.forEach(function(stat){
-                if (stat instanceof AST_SimpleStatement) seq.push(stat.body);
+                if (stat instanceof AST_SimpleStatement && seq.length < 2000) seq.push(stat.body);
                 else push_seq(), ret.push(stat);
             });
             push_seq();
@@ -1086,7 +1086,7 @@ merge(Compressor.prototype, {
             var tt = new TreeTransformer(
                 function before(node, descend, in_list) {
                     if (node instanceof AST_Lambda && !(node instanceof AST_Accessor)) {
-                        if (!compressor.option("keep_fargs")) {
+                        if (compressor.option("unsafe") && !compressor.option("keep_fargs")) {
                             for (var a = node.argnames, i = a.length; --i >= 0;) {
                                 var sym = a[i];
                                 if (sym.unreferenced()) {
@@ -1168,12 +1168,12 @@ merge(Compressor.prototype, {
                             return make_node(AST_EmptyStatement, node);
                         }
                         if (def.length == 0) {
-                            return side_effects;
+                            return in_list ? MAP.splice(side_effects.body) : side_effects;
                         }
                         node.definitions = def;
                         if (side_effects) {
                             side_effects.body.unshift(node);
-                            node = side_effects;
+                            return in_list ? MAP.splice(side_effects.body) : side_effects;
                         }
                         return node;
                     }
@@ -2267,16 +2267,8 @@ merge(Compressor.prototype, {
     OPT(AST_Infinity, function (self, compressor) {
         return make_node(AST_Binary, self, {
             operator : '/',
-            left     : make_node(AST_Number, null, {value: 1}),
+            left     : make_node(AST_Number, self, {value: 1}),
-            right    : make_node(AST_Number, null, {value: 0})
+            right    : make_node(AST_Number, self, {value: 0})
-        });
-    });
-
-    OPT(AST_NaN, function (self, compressor) {
-        return make_node(AST_Binary, self, {
-            operator : '/',
-            left     : make_node(AST_Number, null, {value: 0}),
-            right    : make_node(AST_Number, null, {value: 0})
         });
     });
 
@@ -2343,6 +2335,7 @@ merge(Compressor.prototype, {
             && alternative instanceof AST_Assign
             && consequent.operator == alternative.operator
             && consequent.left.equivalent_to(alternative.left)
+            && !consequent.left.has_side_effects(compressor)
            ) {
             /*
              * Stuff like this:
@@ -2363,6 +2356,7 @@ merge(Compressor.prototype, {
         if (consequent instanceof AST_Call
             && alternative.TYPE === consequent.TYPE
             && consequent.args.length == alternative.args.length
+            && !consequent.expression.has_side_effects(compressor)
             && consequent.expression.equivalent_to(alternative.expression)) {
             if (consequent.args.length == 0) {
                 return make_node(AST_Seq, self, {
@@ -2480,7 +2474,7 @@ merge(Compressor.prototype, {
     });
 
     function literals_in_boolean_context(self, compressor) {
-        if (compressor.option("booleans") && compressor.in_boolean_context()) {
+        if (compressor.option("booleans") && compressor.in_boolean_context() && !self.has_side_effects(compressor)) {
             return make_node(AST_True, self);
         }
         return self;

lib/output.js

@@ -176,7 +176,6 @@ function OutputStream(options) {
                     might_need_space = false;
             }
             might_need_semicolon = false;
-            maybe_newline();
         }
 
         if (!options.beautify && options.preserve_line && stack[stack.length - 1]) {

lib/parse.js

@@ -108,7 +108,7 @@ var OPERATORS = makePredicate([
     "||"
 ]);
 
-var WHITESPACE_CHARS = makePredicate(characters(" \u00a0\n\r\t\f\u000b\u200b\u180e\u2000\u2001\u2002\u2003\u2004\u2005\u2006\u2007\u2008\u2009\u200a\u202f\u205f\u3000"));
+var WHITESPACE_CHARS = makePredicate(characters(" \u00a0\n\r\t\f\u000b\u200b\u180e\u2000\u2001\u2002\u2003\u2004\u2005\u2006\u2007\u2008\u2009\u200a\u202f\u205f\u3000\uFEFF"));
 
 var PUNC_BEFORE_EXPRESSION = makePredicate(characters("[{(,.;:"));
 
@@ -187,8 +187,9 @@ function parse_js_number(num) {
     }
 };
 
-function JS_Parse_Error(message, line, col, pos) {
+function JS_Parse_Error(message, filename, line, col, pos) {
     this.message = message;
+    this.filename = filename;
     this.line = line;
     this.col = col;
     this.pos = pos;
@@ -200,7 +201,7 @@ JS_Parse_Error.prototype.toString = function() {
 };
 
 function js_error(message, filename, line, col, pos) {
-    throw new JS_Parse_Error(message, line, col, pos);
+    throw new JS_Parse_Error(message, filename, line, col, pos);
 };
 
 function is_token(token, type, val) {
@@ -212,7 +213,7 @@ var EX_EOF = {};
 function tokenizer($TEXT, filename, html5_comments) {
 
     var S = {
-        text            : $TEXT.replace(/\uFEFF/g, ''),
+        text            : $TEXT,
         filename        : filename,
         pos             : 0,
         tokpos          : 0,
@@ -297,7 +298,8 @@ function tokenizer($TEXT, filename, html5_comments) {
     };
 
     function skip_whitespace() {
-        while (WHITESPACE_CHARS(peek()))
+        var ch;
+        while (WHITESPACE_CHARS(ch = peek()) || ch == "\u2028" || ch == "\u2029")
             next();
     };
 
@@ -352,8 +354,13 @@ function tokenizer($TEXT, filename, html5_comments) {
           case 120 : return String.fromCharCode(hex_bytes(2)); // \x
           case 117 : return String.fromCharCode(hex_bytes(4)); // \u
           case 10  : return ""; // newline
-          default  : return ch;
+          case 13  :            // \r
+            if (peek() == "\n") { // DOS newline
+                next(true, in_string);
+                return "";
+            }
         }
+        return ch;
     };
 
     function hex_bytes(n) {
@@ -370,7 +377,7 @@ function tokenizer($TEXT, filename, html5_comments) {
     var read_string = with_eof_error("Unterminated string constant", function(quote_char){
         var quote = next(), ret = "";
         for (;;) {
-            var ch = next(true);
+            var ch = next(true, true);
             if (ch == "\\") {
                 // read OctalEscapeSequence (XXX: deprecated if "strict mode")
                 // https://github.com/mishoo/UglifyJS/issues/178

lib/propmangle.js

@@ -0,0 +1,217 @@
+/***********************************************************************
+
+  A JavaScript tokenizer / parser / beautifier / compressor.
+  https://github.com/mishoo/UglifyJS2
+
+  -------------------------------- (C) ---------------------------------
+
+                           Author: Mihai Bazon
+                         <mihai.bazon@gmail.com>
+                       http://mihai.bazon.net/blog
+
+  Distributed under the BSD license:
+
+    Copyright 2012 (c) Mihai Bazon <mihai.bazon@gmail.com>
+
+    Redistribution and use in source and binary forms, with or without
+    modification, are permitted provided that the following conditions
+    are met:
+
+        * Redistributions of source code must retain the above
+          copyright notice, this list of conditions and the following
+          disclaimer.
+
+        * Redistributions in binary form must reproduce the above
+          copyright notice, this list of conditions and the following
+          disclaimer in the documentation and/or other materials
+          provided with the distribution.
+
+    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER “AS IS” AND ANY
+    EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+    IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+    PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER BE
+    LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
+    OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+    PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+    PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
+    TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
+    THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+    SUCH DAMAGE.
+
+ ***********************************************************************/
+
+"use strict";
+
+function find_builtins() {
+    var a = [];
+    [ Object, Array, Function, Number,
+      String, Boolean, Error, Math,
+      Date, RegExp
+    ].forEach(function(ctor){
+        Object.getOwnPropertyNames(ctor).map(add);
+        if (ctor.prototype) {
+            Object.getOwnPropertyNames(ctor.prototype).map(add);
+        }
+    });
+    function add(name) {
+        push_uniq(a, name);
+    }
+    return a;
+}
+
+function mangle_properties(ast, options) {
+    options = defaults(options, {
+        reserved : null,
+        cache : null,
+        only_cache : false
+    });
+
+    var reserved = options.reserved;
+    if (reserved == null)
+        reserved = find_builtins();
+
+    var cache = options.cache;
+    if (cache == null) {
+        cache = {
+            cname: -1,
+            props: new Dictionary()
+        };
+    }
+
+    var names_to_mangle = [];
+
+    // step 1: find candidates to mangle
+    ast.walk(new TreeWalker(function(node){
+        if (node instanceof AST_ObjectKeyVal) {
+            add(node.key);
+        }
+        else if (node instanceof AST_ObjectProperty) {
+            // setter or getter, since KeyVal is handled above
+            add(node.key.name);
+        }
+        else if (node instanceof AST_Dot) {
+            if (this.parent() instanceof AST_Assign) {
+                add(node.property);
+            }
+        }
+        else if (node instanceof AST_Sub) {
+            if (this.parent() instanceof AST_Assign) {
+                addStrings(node.property);
+            }
+        }
+    }));
+
+    // step 2: transform the tree, renaming properties
+    return ast.transform(new TreeTransformer(function(node){
+        if (node instanceof AST_ObjectKeyVal) {
+            if (should_mangle(node.key)) {
+                node.key = mangle(node.key);
+            }
+        }
+        else if (node instanceof AST_ObjectProperty) {
+            // setter or getter
+            if (should_mangle(node.key.name)) {
+                node.key.name = mangle(node.key.name);
+            }
+        }
+        else if (node instanceof AST_Dot) {
+            if (should_mangle(node.property)) {
+                node.property = mangle(node.property);
+            }
+        }
+        else if (node instanceof AST_Sub) {
+            node.property = mangleStrings(node.property);
+        }
+        // else if (node instanceof AST_String) {
+        //     if (should_mangle(node.value)) {
+        //         AST_Node.warn(
+        //             "Found \"{prop}\" property candidate for mangling in an arbitrary string [{file}:{line},{col}]", {
+        //                 file : node.start.file,
+        //                 line : node.start.line,
+        //                 col  : node.start.col,
+        //                 prop : node.value
+        //             }
+        //         );
+        //     }
+        // }
+    }));
+
+    // only function declarations after this line
+
+    function can_mangle(name) {
+        if (reserved.indexOf(name) >= 0) return false;
+        if (options.only_cache) {
+            return cache.props.has(name);
+        }
+        if (/^[0-9.]+$/.test(name)) return false;
+        return true;
+    }
+
+    function should_mangle(name) {
+        if (reserved.indexOf(name) >= 0) return false;
+        return cache.props.has(name)
+            || names_to_mangle.indexOf(name) >= 0;
+    }
+
+    function add(name) {
+        if (can_mangle(name))
+            push_uniq(names_to_mangle, name);
+    }
+
+    function mangle(name) {
+        var mangled = cache.props.get(name);
+        if (!mangled) {
+            do {
+                mangled = base54(++cache.cname);
+            } while (!can_mangle(mangled));
+            cache.props.set(name, mangled);
+        }
+        return mangled;
+    }
+
+    function addStrings(node) {
+        var out = {};
+        try {
+            (function walk(node){
+                node.walk(new TreeWalker(function(node){
+                    if (node instanceof AST_Seq) {
+                        walk(node.cdr);
+                        return true;
+                    }
+                    if (node instanceof AST_String) {
+                        add(node.value);
+                        return true;
+                    }
+                    if (node instanceof AST_Conditional) {
+                        walk(node.consequent);
+                        walk(node.alternative);
+                        return true;
+                    }
+                    throw out;
+                }));
+            })(node);
+        } catch(ex) {
+            if (ex !== out) throw ex;
+        }
+    }
+
+    function mangleStrings(node) {
+        return node.transform(new TreeTransformer(function(node){
+            if (node instanceof AST_Seq) {
+                node.cdr = mangleStrings(node.cdr);
+            }
+            else if (node instanceof AST_String) {
+                if (should_mangle(node.value)) {
+                    node.value = mangle(node.value);
+                }
+            }
+            else if (node instanceof AST_Conditional) {
+                node.consequent = mangleStrings(node.consequent);
+                node.alternative = mangleStrings(node.alternative);
+            }
+            return node;
+        }));
+    }
+
+}

lib/scope.js

@@ -67,18 +67,26 @@ SymbolDef.prototype = {
                     || this.orig[0] instanceof AST_SymbolDefun));
     },
     mangle: function(options) {
-        if (!this.mangled_name && !this.unmangleable(options)) {
+        var cache = options.cache && options.cache.props;
+        if (this.global && cache && cache.has(this.name)) {
+            this.mangled_name = cache.get(this.name);
+        }
+        else if (!this.mangled_name && !this.unmangleable(options)) {
             var s = this.scope;
             if (!options.screw_ie8 && this.orig[0] instanceof AST_SymbolLambda)
                 s = s.parent_scope;
             this.mangled_name = s.next_mangled(options, this);
+            if (this.global && cache) {
+                cache.set(this.name, this.mangled_name);
+            }
         }
     }
 };
 
 AST_Toplevel.DEFMETHOD("figure_out_scope", function(options){
     options = defaults(options, {
-        screw_ie8: false
+        screw_ie8: false,
+        cache: null
     });
 
     // pass 1: setup scope chaining and handle definitions
@@ -183,6 +191,10 @@ AST_Toplevel.DEFMETHOD("figure_out_scope", function(options){
         }
     });
     self.walk(tw);
+
+    if (options.cache) {
+        this.cname = options.cache.cname;
+    }
 });
 
 AST_Scope.DEFMETHOD("init_scope_vars", function(nesting){
@@ -344,6 +356,15 @@ AST_Toplevel.DEFMETHOD("mangle_names", function(options){
     // the AST_SymbolDeclaration that it points to).
     var lname = -1;
     var to_mangle = [];
+
+    if (options.cache) {
+        this.globals.each(function(symbol){
+            if (options.except.indexOf(symbol.name) < 0) {
+                to_mangle.push(symbol);
+            }
+        });
+    }
+
     var tw = new TreeWalker(function(node, descend){
         if (node instanceof AST_LabeledStatement) {
             // lname is incremented when we get to the AST_Label
@@ -378,6 +399,10 @@ AST_Toplevel.DEFMETHOD("mangle_names", function(options){
     });
     this.walk(tw);
     to_mangle.forEach(function(def){ def.mangle(options) });
+
+    if (options.cache) {
+        options.cache.cname = this.cname;
+    }
 });
 
 AST_Toplevel.DEFMETHOD("compute_char_frequency", function(options){

lib/utils.js

@@ -106,10 +106,12 @@ function defaults(args, defs, croak) {
 };
 
 function merge(obj, ext) {
+    var count = 0;
     for (var i in ext) if (ext.hasOwnProperty(i)) {
         obj[i] = ext[i];
+        count++;
     }
-    return obj;
+    return count;
 };
 
 function noop() {};
@@ -298,5 +300,11 @@ Dictionary.prototype = {
         for (var i in this._values)
             ret.push(f(this._values[i], i.substr(1)));
         return ret;
-    }
+    },
+    toObject: function() { return this._values }
+};
+Dictionary.fromObject = function(obj) {
+    var dict = new Dictionary();
+    dict._size = merge(dict._values, obj);
+    return dict;
 };

package.json

@@ -1,37 +1,51 @@
 {
   "name": "uglify-js",
   "description": "JavaScript parser, mangler/compressor and beautifier toolkit",
-    "homepage": "http://lisperator.net/uglifyjs",
+  "homepage": "http://lisperator.net/uglifyjs",
-    "main": "tools/node.js",
+  "author": "Mihai Bazon <mihai.bazon@gmail.com> (http://lisperator.net/)",
-    "version": "2.4.16",
+  "license": "BSD",
-    "engines": { "node" : ">=0.4.0" },
+  "version": "2.4.23",
-    "maintainers": [{
+  "engines": {
-        "name": "Mihai Bazon",
+    "node": ">=0.4.0"
-        "email": "mihai.bazon@gmail.com",
+  },
-        "web": "http://lisperator.net/"
+  "maintainers": [
-    }],
+    "Mihai Bazon <mihai.bazon@gmail.com> (http://lisperator.net/)"
-    "repository": {
+  ],
-        "type": "git",
+  "repository": {
-        "url": "https://github.com/mishoo/UglifyJS2.git"
+    "type": "git",
-    },
+    "url": "https://github.com/mishoo/UglifyJS2.git"
-    "dependencies": {
+  },
-        "async"      : "~0.2.6",
+  "bugs": {
-        "source-map" : "0.1.34",
+    "url": "https://github.com/mishoo/UglifyJS2/issues"
-        "yargs": "~1.3.3",
+  },
-        "uglify-to-browserify": "~1.0.0"
+  "main": "tools/node.js",
-    },
+  "bin": {
-    "devDependencies": {
+    "uglifyjs": "bin/uglifyjs"
-        "acorn": "~0.6.0",
+  },
-        "escodegen": "~1.3.3",
+  "files": [
-        "esfuzz": "~0.3.1",
+    "bin",
-        "estraverse": "~1.5.1"
+    "lib",
-    },
+    "tools",
-    "browserify": {
+    "LICENSE"
-        "transform": [ "uglify-to-browserify" ]
+  ],
-    },
+  "dependencies": {
-    "bin": {
+    "async": "~0.2.6",
-        "uglifyjs" : "bin/uglifyjs"
+    "source-map": "0.1.34",
-    },
+    "uglify-to-browserify": "~1.0.0",
-    "license": "BSD",
+    "yargs": "~3.5.4"
-    "scripts": {"test": "node test/run-tests.js"}
+  },
+  "devDependencies": {
+    "acorn": "~0.6.0",
+    "escodegen": "~1.3.3",
+    "esfuzz": "~0.3.1",
+    "estraverse": "~1.5.1"
+  },
+  "browserify": {
+    "transform": [
+      "uglify-to-browserify"
+    ]
+  },
+  "scripts": {
+    "test": "node test/run-tests.js"
+  }
 }

test/compress/conditionals.js

@@ -86,7 +86,9 @@ ifs_4: {
             x(foo)[10].bar.baz = something_else();
     }
     expect: {
-        x(foo)[10].bar.baz = (foo && bar) ? something() : something_else();
+        foo && bar
+            ? x(foo)[10].bar.baz = something()
+            : x(foo)[10].bar.baz = something_else();
     }
 }
 
@@ -133,6 +135,7 @@ ifs_6: {
         comparisons: true
     };
     input: {
+        var x;
         if (!foo && !bar && !baz && !boo) {
             x = 10;
         } else {
@@ -140,6 +143,7 @@ ifs_6: {
         }
     }
     expect: {
+        var x;
         x = foo || bar || baz || boo ? 20 : 10;
     }
 }
@@ -149,6 +153,7 @@ cond_1: {
         conditionals: true
     };
     input: {
+        var do_something; // if undeclared it's assumed to have side-effects
         if (some_condition()) {
             do_something(x);
         } else {
@@ -156,6 +161,7 @@ cond_1: {
         }
     }
     expect: {
+        var do_something;
         do_something(some_condition() ? x : y);
     }
 }
@@ -165,6 +171,7 @@ cond_2: {
         conditionals: true
     };
     input: {
+        var x, FooBar;
         if (some_condition()) {
             x = new FooBar(1);
         } else {
@@ -172,6 +179,7 @@ cond_2: {
         }
     }
     expect: {
+        var x, FooBar;
         x = new FooBar(some_condition() ? 1 : 2);
     }
 }
@@ -181,6 +189,7 @@ cond_3: {
         conditionals: true
     };
     input: {
+        var FooBar;
         if (some_condition()) {
             new FooBar(1);
         } else {
@@ -188,6 +197,7 @@ cond_3: {
         }
     }
     expect: {
+        var FooBar;
         some_condition() ? new FooBar(1) : FooBar(2);
     }
 }
@@ -197,6 +207,7 @@ cond_4: {
         conditionals: true
     };
     input: {
+        var do_something;
         if (some_condition()) {
             do_something();
         } else {
@@ -204,6 +215,7 @@ cond_4: {
         }
     }
     expect: {
+        var do_something;
         some_condition(), do_something();
     }
 }
@@ -303,6 +315,7 @@ cond_7_1: {
         evaluate    : true
     };
     input: {
+        var x;
         // access to global should be assumed to have side effects
         if (y) {
             x = 1+1;
@@ -311,6 +324,7 @@ cond_7_1: {
         }
     }
     expect: {
+        var x;
         x = (y, 2);
     }
 }
@@ -321,6 +335,7 @@ cond_8: {
         evaluate    : true
     };
     input: {
+        var a;
         // compress these
         a = condition ? true : false;
 
@@ -355,6 +370,7 @@ cond_8: {
 
     }
     expect: {
+        var a;
         a = !!condition;
         a = !condition;
         a = !!condition();
@@ -367,4 +383,4 @@ cond_8: {
         a = condition ? 0 : true;
         a = condition ? 1 : 0;
     }
-}
+}

test/compress/drop-unused.js

@@ -1,5 +1,5 @@
 unused_funarg_1: {
-    options = { unused: true };
+    options = { unused: true, unsafe: true };
     input: {
         function f(a, b, c, d, e) {
             return a + b;
@@ -13,7 +13,7 @@ unused_funarg_1: {
 }
 
 unused_funarg_2: {
-    options = { unused: true };
+    options = { unused: true, unsafe: true };
     input: {
         function f(a, b, c, d, e) {
             return a + c;
@@ -165,7 +165,7 @@ used_var_in_catch: {
 }
 
 keep_fnames: {
-    options = { unused: true, keep_fnames: true };
+    options = { unused: true, keep_fnames: true, unsafe: true };
     input: {
         function foo() {
             return function bar(baz) {};
@@ -176,4 +176,4 @@ keep_fnames: {
             return function bar() {};
         }
     }
-}
+}

test/compress/issue-597.js

@@ -6,7 +6,7 @@ NaN_and_Infinity_must_have_parens: {
     }
     expect: {
         (1/0).toString();
-        (0/0).toString();
+        NaN.toString();         // transformation to 0/0 dropped
     }
 }
 

test/run-tests.js

@@ -84,7 +84,12 @@ function run_compress_tests() {
                 warnings: false
             });
             var cmp = new U.Compressor(options, true);
-            var expect = make_code(as_toplevel(test.expect), false);
+            var expect;
+            if (test.expect) {
+                expect = make_code(as_toplevel(test.expect), false);
+            } else {
+                expect = test.expect_exact;
+            }
             var input = as_toplevel(test.input);
             var input_code = make_code(test.input);
             var output = input.transform(cmp);
@@ -150,7 +155,7 @@ function parse_test(file) {
             }
             if (node instanceof U.AST_LabeledStatement) {
                 assert.ok(
-                    node.label.name == "input" || node.label.name == "expect",
+                    node.label.name == "input" || node.label.name == "expect" || node.label.name == "expect_exact",
                     tmpl("Unsupported label {name} [{line},{col}]", {
                         name: node.label.name,
                         line: node.label.start.line,
@@ -162,7 +167,16 @@ function parse_test(file) {
                     if (stat.body.length == 1) stat = stat.body[0];
                     else if (stat.body.length == 0) stat = new U.AST_EmptyStatement();
                 }
-                test[node.label.name] = stat;
+                if (node.label.name === "expect_exact") {
+                    if (!(stat.TYPE === "SimpleStatement" && stat.body.TYPE === "String")) {
+                        throw new Error(
+                            "The value of the expect_exact clause should be a string, " +
+                            "like `expect_exact: \"some.exact.javascript;\"`");
+                    }
+                    test[node.label.name] = stat.body.start.value
+                } else {
+                    test[node.label.name] = stat;
+                }
                 return true;
             }
         });

tools/node.js

@@ -1,10 +1,8 @@
 var path = require("path");
 var fs = require("fs");
 var vm = require("vm");
-var sys = require("util");
 
 var UglifyJS = vm.createContext({
-    sys           : sys,
     console       : console,
     process       : process,
     Buffer        : Buffer,
@@ -19,7 +17,7 @@ function load_global(file) {
     } catch(ex) {
         // XXX: in case of a syntax error, the message is kinda
         // useless. (no location information).
-        sys.debug("ERROR in file: " + file + " / " + ex);
+        console.log("ERROR in file: " + file + " / " + ex);
         process.exit(1);
     }
 };
@@ -33,7 +31,8 @@ var FILES = exports.FILES = [
     "../lib/output.js",
     "../lib/compress.js",
     "../lib/sourcemap.js",
-    "../lib/mozilla-ast.js"
+    "../lib/mozilla-ast.js",
+    "../lib/propmangle.js"
 ].map(function(file){
     return fs.realpathSync(path.join(path.dirname(__filename), file));
 });
@@ -41,7 +40,7 @@ var FILES = exports.FILES = [
 FILES.forEach(load_global);
 
 UglifyJS.AST_Node.warn_function = function(txt) {
-    sys.error("WARN: " + txt);
+    console.error("WARN: %s", txt);
 };
 
 // XXX: perhaps we shouldn't export everything but heck, I'm lazy.
@@ -192,3 +191,63 @@ exports.describe_ast = function() {
     doitem(UglifyJS.AST_Node);
     return out + "";
 };
+
+function readReservedFile(filename, reserved) {
+    if (!reserved) {
+        reserved = { vars: [], props: [] };
+    }
+    var data = fs.readFileSync(filename, "utf8");
+    data = JSON.parse(data);
+    if (data.vars) {
+        data.vars.forEach(function(name){
+            UglifyJS.push_uniq(reserved.vars, name);
+        });
+    }
+    if (data.props) {
+        data.props.forEach(function(name){
+            UglifyJS.push_uniq(reserved.props, name);
+        });
+    }
+    return reserved;
+}
+
+exports.readReservedFile = readReservedFile;
+
+exports.readDefaultReservedFile = function(reserved) {
+    return readReservedFile(path.join(__dirname, "domprops.json"), reserved);
+};
+
+exports.readNameCache = function(filename, key) {
+    var cache = null;
+    if (filename) {
+        try {
+            var cache = fs.readFileSync(filename, "utf8");
+            cache = JSON.parse(cache)[key];
+            if (!cache) throw "init";
+            cache.props = UglifyJS.Dictionary.fromObject(cache.props);
+        } catch(ex) {
+            cache = {
+                cname: -1,
+                props: new UglifyJS.Dictionary()
+            };
+        }
+    }
+    return cache;
+};
+
+exports.writeNameCache = function(filename, key, cache) {
+    if (filename) {
+        var data;
+        try {
+            data = fs.readFileSync(filename, "utf8");
+            data = JSON.parse(data);
+        } catch(ex) {
+            data = {};
+        }
+        data[key] = {
+            cname: cache.cname,
+            props: cache.props.toObject()
+        };
+        fs.writeFileSync(filename, JSON.stringify(data, null, 2), "utf8");
+    }
+};

tools/props.html

@@ -0,0 +1,61 @@
+<html>
+  <head>
+  </head>
+  <body>
+    <script>(function(){
+      var props = {};
+
+      function addObject(obj) {
+        if (obj == null) return;
+        try {
+          Object.getOwnPropertyNames(obj).forEach(add);
+        } catch(ex) {}
+        if (obj.prototype) {
+          Object.getOwnPropertyNames(obj.prototype).forEach(add);
+        }
+        if (typeof obj == "function") {
+          try {
+            Object.getOwnPropertyNames(new obj).forEach(add);
+          } catch(ex) {}
+        }
+      }
+
+      function add(name) {
+        props[name] = true;
+      }
+
+      Object.getOwnPropertyNames(window).forEach(function(thing){
+        addObject(window[thing]);
+      });
+
+      try {
+        addObject(new Event("click"));
+        addObject(new Event("contextmenu"));
+        addObject(new Event("mouseup"));
+        addObject(new Event("mousedown"));
+        addObject(new Event("keydown"));
+        addObject(new Event("keypress"));
+        addObject(new Event("keyup"));
+      } catch(ex) {}
+
+      var ta = document.createElement("textarea");
+      ta.style.width = "100%";
+      ta.style.height = "20em";
+      ta.style.boxSizing = "border-box";
+      <!-- ta.value = Object.keys(props).sort(cmp).map(function(name){ -->
+      <!--   return JSON.stringify(name); -->
+      <!-- }).join(",\n"); -->
+      ta.value = JSON.stringify({
+        vars: [],
+        props: Object.keys(props).sort(cmp)
+      }, null, 2);
+      document.body.appendChild(ta);
+
+      function cmp(a, b) {
+        a = a.toLowerCase();
+        b = b.toLowerCase();
+        return a < b ? -1 : a > b ? 1 : 0;
+      }
+    })();</script>
+  </body>
+</html>