inline Function() as code

- improve upon #203
- bail out on any local/global variable collisions

lib/compress.js

@@ -2165,53 +2165,29 @@ merge(Compressor.prototype, {
                         argnames: [],
                         body: []
                     });
-                    if (all(self.args, function(x){ return x instanceof AST_String })) {
-                        // quite a corner-case, but we can handle it:
-                        //   https://github.com/mishoo/UglifyJS2/issues/203
-                        // if the code argument is a constant, then we can minify it.
-                        try {
-                            var code = "(function(" + self.args.slice(0, -1).map(function(arg){
-                                return arg.value;
-                            }).join(",") + "){" + self.args[self.args.length - 1].value + "})()";
-                            var ast = parse(code);
-                            ast.figure_out_scope({ screw_ie8: compressor.option("screw_ie8") });
-                            var comp = new Compressor(compressor.options);
-                            ast = ast.transform(comp);
-                            ast.figure_out_scope({ screw_ie8: compressor.option("screw_ie8") });
-                            ast.mangle_names();
-                            var fun;
-                            try {
-                                ast.walk(new TreeWalker(function(node){
-                                    if (node instanceof AST_Lambda) {
-                                        fun = node;
-                                        throw ast;
-                                    }
-                                }));
-                            } catch(ex) {
-                                if (ex !== ast) throw ex;
-                            };
-                            if (!fun) return self;
-                            var args = fun.argnames.map(function(arg, i){
-                                return make_node(AST_String, self.args[i], {
-                                    value: arg.print_to_string()
-                                });
-                            });
-                            var code = OutputStream();
-                            AST_BlockStatement.prototype._codegen.call(fun, fun, code);
-                            code = code.toString().replace(/^\{|\}$/g, "");
-                            args.push(make_node(AST_String, self.args[self.args.length - 1], {
-                                value: code
-                            }));
-                            self.args = args;
-                            return self;
-                        } catch(ex) {
-                            if (ex instanceof JS_Parse_Error) {
-                                compressor.warn("Error parsing code passed to new Function [{file}:{line},{col}]", self.args[self.args.length - 1].start);
-                                compressor.warn(ex.toString());
-                            } else {
-                                console.log(ex);
-                                throw ex;
-                            }
+                    // new Function("x", "return x") => function(x){return x}
+                    try {
+                        var args = self.args.map(function(arg) {
+                            if (!(arg instanceof AST_String)) throw self;
+                            return arg.value;
+                        });
+                        var code = args.pop();
+                        var ast = parse("(function(" + args.join() + "){" + code + "})");
+                        ast.figure_out_scope({ screw_ie8: compressor.option("screw_ie8") });
+                        var scope = compressor.find_parent(AST_Scope);
+                        ast.globals.each(function(g) {
+                            var def = scope.find_variable(g.name);
+                            if (def && !(def.scope instanceof AST_Toplevel)) throw self;
+                        });
+                        var fun = ast.body[0].body;
+                        fun.parent_scope = scope;
+                        return fun;
+                    } catch(ex) {
+                        if (ex instanceof JS_Parse_Error) {
+                            compressor.warn("Error parsing code passed to new Function [{file}:{line},{col}]", self.args[self.args.length - 1].start);
+                            compressor.warn(ex.toString());
+                        } else if (ex !== self) {
+                            throw ex;
                         }
                     }
                     break;

lib/utils.js

@@ -262,13 +262,6 @@ function makePredicate(words) {
     return new Function("str", f);
 };
 
-function all(array, predicate) {
-    for (var i = array.length; --i >= 0;)
-        if (!predicate(array[i]))
-            return false;
-    return true;
-};
-
 function Dictionary() {
     this._values = Object.create(null);
     this._size = 0;

test/compress/functions.js

@@ -6,3 +6,55 @@ non_ascii_function_identifier_name: {
     }
     expect_exact: "function fooλ(δλ){}function λ(δλ){}(function λ(δλ){})();"
 }
+
+unsafe_eval: {
+    options = {
+        unsafe: true,
+    }
+    input: {
+        var a = Function("x", "return x");
+
+        function e() {
+            var a;
+            return Function("return a");
+        }
+
+        function f() {
+            return Function("return a");
+        }
+
+        function g(a) {
+            return Function("b", "return [ a, b ]");
+        }
+
+        function h(b) {
+            return Function("b", "c", "return [ a, b, c ]");
+        }
+    }
+    expect: {
+        var a = function(x) {
+            return x;
+        };
+
+        function e() {
+            var a;
+            return Function("return a");
+        }
+
+        function f() {
+            return function() {
+                return a;
+            };
+        }
+
+        function g(a) {
+            return Function("b", "return [ a, b ]");
+        }
+
+        function h(b) {
+            return function(b, c) {
+                return [ a, b, c ];
+            };
+        }
+    }
+}