v2.4.8

bugfix #242

README.md

@@ -249,6 +249,9 @@ to set `true`; it's effectively a shortcut for `foo=true`).
   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.
+
 ### The `unsafe` option
 
 It enables some transformations that *might* break code logic in certain

lib/ast.js

@@ -498,12 +498,6 @@ var AST_Try = DEFNODE("Try", "bcatch bfinally", {
     }
 }, AST_Block);
 
-// XXX: this is wrong according to ECMA-262 (12.4).  the catch block
-// should introduce another scope, as the argname should be visible
-// only inside the catch block.  However, doing it this way because of
-// IE which simply introduces the name in the surrounding scope.  If
-// we ever want to fix this then AST_Catch should inherit from
-// AST_Scope.
 var AST_Catch = DEFNODE("Catch", "argname", {
     $documentation: "A `catch` node; only makes sense as part of a `try` statement",
     $propdoc: {

lib/compress.js

@@ -70,6 +70,7 @@ function Compressor(options, false_by_default) {
         pure_funcs    : null,
         negate_iife   : !false_by_default,
         screw_ie8     : false,
+        drop_console  : false,
 
         warnings      : true,
         global_defs   : {}
@@ -1669,10 +1670,10 @@ merge(Compressor.prototype, {
                                 return arg.value;
                             }).join(",") + "){" + self.args[self.args.length - 1].value + "})()";
                             var ast = parse(code);
-                            ast.figure_out_scope();
+                            ast.figure_out_scope({ screw_ie8: compressor.option("screw_ie8") });
                             var comp = new Compressor(compressor.options);
                             ast = ast.transform(comp);
-                            ast.figure_out_scope();
+                            ast.figure_out_scope({ screw_ie8: compressor.option("screw_ie8") });
                             ast.mangle_names();
                             var fun;
                             try {
@@ -1773,6 +1774,14 @@ merge(Compressor.prototype, {
                 return make_node(AST_Undefined, self).transform(compressor);
             }
         }
+        if (compressor.option("drop_console")) {
+            if (self.expression instanceof AST_PropAccess &&
+                self.expression.expression instanceof AST_SymbolRef &&
+                self.expression.expression.name == "console" &&
+                self.expression.expression.undeclared()) {
+                return make_node(AST_Undefined, self).transform(compressor);
+            }
+        }
         return self.evaluate(compressor)[0];
     });
 
@@ -1811,10 +1820,16 @@ merge(Compressor.prototype, {
         }
         if (compressor.option("cascade")) {
             if (self.car instanceof AST_Assign
-                && !self.car.left.has_side_effects(compressor)
+                && !self.car.left.has_side_effects(compressor)) {
-                && self.car.left.equivalent_to(self.cdr)) {
+                if (self.car.left.equivalent_to(self.cdr)) {
                     return self.car;
                 }
+                if (self.cdr instanceof AST_Call
+                    && self.cdr.expression.equivalent_to(self.car.left)) {
+                    self.cdr.expression = self.car;
+                    return self.cdr;
+                }
+            }
             if (!self.car.has_side_effects(compressor)
                 && !self.cdr.has_side_effects(compressor)
                 && self.car.equivalent_to(self.cdr)) {

lib/scope.js

@@ -71,27 +71,34 @@ SymbolDef.prototype = {
     }
 };
 
-AST_Toplevel.DEFMETHOD("figure_out_scope", function(){
+AST_Toplevel.DEFMETHOD("figure_out_scope", function(options){
-    // This does what ast_add_scope did in UglifyJS v1.
+    options = defaults(options, {
-    //
+        screw_ie8: false
-    // Part of it could be done at parse time, but it would complicate
+    });
-    // the parser (and it's already kinda complex).  It's also worth
-    // having it separated because we might need to call it multiple
-    // times on the same tree.
 
     // pass 1: setup scope chaining and handle definitions
     var self = this;
     var scope = self.parent_scope = null;
+    var defun = null;
     var nesting = 0;
     var tw = new TreeWalker(function(node, descend){
+        if (options.screw_ie8 && node instanceof AST_Catch) {
+            var save_scope = scope;
+            scope = new AST_Scope(node);
+            scope.init_scope_vars(nesting);
+            scope.parent_scope = save_scope;
+            descend();
+            scope = save_scope;
+            return true;
+        }
         if (node instanceof AST_Scope) {
             node.init_scope_vars(nesting);
             var save_scope = node.parent_scope = scope;
-            ++nesting;
+            var save_defun = defun;
-            scope = node;
+            defun = scope = node;
-            descend();
+            ++nesting; descend(); --nesting;
             scope = save_scope;
-            --nesting;
+            defun = save_defun;
             return true;        // don't descend again in TreeWalker
         }
         if (node instanceof AST_Directive) {
@@ -108,7 +115,7 @@ AST_Toplevel.DEFMETHOD("figure_out_scope", function(){
             node.scope = scope;
         }
         if (node instanceof AST_SymbolLambda) {
-            scope.def_function(node);
+            defun.def_function(node);
         }
         else if (node instanceof AST_SymbolDefun) {
             // Careful here, the scope where this should be defined is
@@ -116,22 +123,17 @@ AST_Toplevel.DEFMETHOD("figure_out_scope", function(){
             // scope when we encounter the AST_Defun node (which is
             // instanceof AST_Scope) but we get to the symbol a bit
             // later.
-            (node.scope = scope.parent_scope).def_function(node);
+            (node.scope = defun.parent_scope).def_function(node);
         }
         else if (node instanceof AST_SymbolVar
                  || node instanceof AST_SymbolConst) {
-            var def = scope.def_variable(node);
+            var def = defun.def_variable(node);
             def.constant = node instanceof AST_SymbolConst;
             def.init = tw.parent().value;
         }
         else if (node instanceof AST_SymbolCatch) {
-            // XXX: this is wrong according to ECMA-262 (12.4).  the
+            (options.screw_ie8 ? scope : defun)
-            // `catch` argument name should be visible only inside the
+                .def_variable(node);
-            // catch block.  For a quick fix AST_Catch should inherit
-            // from AST_Scope.  Keeping it this way because of IE,
-            // which doesn't obey the standard. (it introduces the
-            // identifier in the enclosing scope)
-            scope.def_variable(node);
         }
     });
     self.walk(tw);
@@ -244,6 +246,11 @@ AST_Scope.DEFMETHOD("next_mangled", function(options){
     out: while (true) {
         var m = base54(++this.cname);
         if (!is_identifier(m)) continue; // skip over "do"
+
+        // https://github.com/mishoo/UglifyJS2/issues/242 -- do not
+        // shadow a name excepted from mangling.
+        if (options.except.indexOf(m) >= 0) continue;
+
         // we must ensure that the mangled name does not shadow a name
         // from some parent scope that is referenced in this or in
         // inner scopes.

lib/sourcemap.js

@@ -49,6 +49,9 @@ function SourceMap(options) {
         file : null,
         root : null,
         orig : null,
+
+        orig_line_diff : 0,
+        dest_line_diff : 0,
     });
     var generator = new MOZ_SourceMap.SourceMapGenerator({
         file       : options.file,
@@ -67,8 +70,8 @@ function SourceMap(options) {
             name = info.name;
         }
         generator.addMapping({
-            generated : { line: gen_line, column: gen_col },
+            generated : { line: gen_line + options.dest_line_diff, column: gen_col },
-            original  : { line: orig_line, column: orig_col },
+            original  : { line: orig_line + options.orig_line_diff, column: orig_col },
             source    : source,
             name      : name
         });

lib/utils.js

@@ -82,9 +82,12 @@ function repeat_string(str, i) {
 };
 
 function DefaultsError(msg, defs) {
+    Error.call(this, msg);
     this.msg = msg;
     this.defs = defs;
 };
+DefaultsError.prototype = Object.create(Error.prototype);
+DefaultsError.prototype.constructor = DefaultsError;
 
 DefaultsError.croak = function(msg, defs) {
     throw new DefaultsError(msg, defs);

package.json

@@ -3,7 +3,7 @@
     "description": "JavaScript parser, mangler/compressor and beautifier toolkit",
     "homepage": "http://lisperator.net/uglifyjs",
     "main": "tools/node.js",
-    "version": "2.4.5",
+    "version": "2.4.8",
     "engines": { "node" : ">=0.4.0" },
     "maintainers": [{
         "name": "Mihai Bazon",

test/compress/drop-unused.js

@@ -119,3 +119,47 @@ unused_keep_setter_arg: {
         }
     }
 }
+
+unused_var_in_catch: {
+    options = { unused: true };
+    input: {
+        function foo() {
+            try {
+                foo();
+            } catch(ex) {
+                var x = 10;
+            }
+        }
+    }
+    expect: {
+        function foo() {
+            try {
+                foo();
+            } catch(ex) {}
+        }
+    }
+}
+
+used_var_in_catch: {
+    options = { unused: true };
+    input: {
+        function foo() {
+            try {
+                foo();
+            } catch(ex) {
+                var x = 10;
+            }
+            return x;
+        }
+    }
+    expect: {
+        function foo() {
+            try {
+                foo();
+            } catch(ex) {
+                var x = 10;
+            }
+            return x;
+        }
+    }
+}