Remove str-to-func eval of named function factory (emscripten-core#18748)

sbc100 · NickCarducci · web-flow · commit df727461762e · 2023-02-15T09:07:52.000-08:00
For support for this feature see: https://caniuse.com/mdn-javascript_operators_object_initializer_computed_property_names Based on emscripten-core#17296 Co-authored-by: Nick Carducci <nmcarducci@gmail.com>
diff --git a/src/embind/embind.js b/src/embind/embind.js
@@ -194,25 +194,16 @@ var LibraryEmbind = {
   },
 
 
-  // from https://github.com/imvu/imvujs/blob/master/src/function.js
   $createNamedFunction__deps: ['$makeLegalFunctionName'],
   $createNamedFunction: function(name, body) {
     name = makeLegalFunctionName(name);
-#if DYNAMIC_EXECUTION == 0
-    return function() {
-      "use strict";
-      return body.apply(this, arguments);
-    };
-#else
-    /*jshint evil:true*/
-    return new Function(
-        "body",
-        "return function " + name + "() {\n" +
-        "    \"use strict\";" +
-        "    return body.apply(this, arguments);\n" +
-        "};\n"
-    )(body);
-#endif
+    // Use an abject with a computed property name to create a new function with
+    // a name specified at runtime, but without using `new Function` or `eval`.
+    return {
+      [name]: function() {
+        return body.apply(this, arguments);
+      }
+    }[name];
   },
 
   $embindRepr: function(v) {
diff --git a/test/embind/embind.test.js b/test/embind/embind.test.js
@@ -162,17 +162,16 @@ module({
         });
 
         test("setting and getting property on unrelated class throws error", function() {
-            var className = cm['DYNAMIC_EXECUTION'] ? 'HasTwoBases' : '';
             var a = new cm.HasTwoBases;
             var e = assert.throws(cm.BindingError, function() {
                 Object.getOwnPropertyDescriptor(cm.HeldBySmartPtr.prototype, 'i').set.call(a, 10);
             });
-            assert.equal('HeldBySmartPtr.i setter incompatible with "this" of type ' + className, e.message);
+            assert.equal('HeldBySmartPtr.i setter incompatible with "this" of type HasTwoBases', e.message);
 
             var e = assert.throws(cm.BindingError, function() {
                 Object.getOwnPropertyDescriptor(cm.HeldBySmartPtr.prototype, 'i').get.call(a);
             });
-            assert.equal('HeldBySmartPtr.i getter incompatible with "this" of type ' + className, e.message);
+            assert.equal('HeldBySmartPtr.i getter incompatible with "this" of type HasTwoBases', e.message);
 
             a.delete();
         });
@@ -1766,8 +1765,7 @@ module({
 
         test("smart pointer object has correct constructor name", function() {
             var e = new cm.HeldBySmartPtr(10, "foo");
-            var expectedName = cm['DYNAMIC_EXECUTION'] ? "HeldBySmartPtr" : "";
-            assert.equal(expectedName, e.constructor.name);
+            assert.equal("HeldBySmartPtr", e.constructor.name);
             e.delete();
         });
 
@@ -2510,12 +2508,11 @@ module({
     });
 
     BaseFixture.extend("function names", function() {
+        assert.equal('ValHolder', cm.ValHolder.name);
         if (!cm['DYNAMIC_EXECUTION']) {
-          assert.equal('', cm.ValHolder.name);
           assert.equal('', cm.ValHolder.prototype.setVal.name);
           assert.equal('', cm.ValHolder.makeConst.name);
         } else {
-          assert.equal('ValHolder', cm.ValHolder.name);
           assert.equal('ValHolder$setVal', cm.ValHolder.prototype.setVal.name);
           assert.equal('ValHolder$makeConst', cm.ValHolder.makeConst.name);
         }
diff --git a/test/test_other.py b/test/test_other.py
@@ -12370,6 +12370,13 @@ def test_es5_transpile(self, args):
         // arror funcs + const
         const bar = () => 2;
         err('bar: ' + bar());
+
+        // Computed property names
+        var key = 'mykey';
+        var obj2 = {
+          [key]: 42,
+        };
+        err('value: ' + obj2[key]);
       }
     });
     ''')
@@ -12403,19 +12410,19 @@ def check_for_es6(filename, expect):
     print('with old browser')
     self.emcc_args.remove('-Werror')
     self.set_setting('MIN_CHROME_VERSION', '10')
-    self.do_runf('test.c', 'prop: 1\nbar: 2\n', output_basename='test2')
-    check_for_es6('test2.js', False)
+    self.do_runf('test.c', 'prop: 1\nbar: 2\n', output_basename='test_old')
+    check_for_es6('test_old.js', False)
 
     # If we add `--closure=0` that transpiler (closure) is not run at all
     print('with old browser + --closure=0')
-    self.do_runf('test.c', 'prop: 1\nbar: 2\n', emcc_args=['--closure=0'], output_basename='test3')
-    check_for_es6('test3.js', True)
+    self.do_runf('test.c', 'prop: 1\nbar: 2\n', emcc_args=['--closure=0'], output_basename='test_no_closure')
+    check_for_es6('test_no_closure.js', True)
 
     # If we use `--closure=1` closure will run in full optimization mode
     # and also transpile to ES5
     print('with old browser + --closure=1')
-    self.do_runf('test.c', 'prop: 1\nbar: 2\n', emcc_args=['--closure=1'], output_basename='test4')
-    check_for_es6('test4.js', False)
+    self.do_runf('test.c', 'prop: 1\nbar: 2\n', emcc_args=['--closure=1'], output_basename='test_closure')
+    check_for_es6('test_closure.js', False)
 
   def test_gmtime_noleak(self):
     # Confirm that gmtime_r does not leak when called in isolation.
