Restrict FunctionDeclarations in Statement position

test/mjsunit/harmony/sloppy-implicit-block-function.js

+// Copyright 2016 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --no-harmony-restrictive-declarations
+
+// ES#sec-functiondeclarations-in-ifstatement-statement-clauses
+// Annex B 3.4 FunctionDeclarations in IfStatement Statement Clauses
+// In sloppy mode, function declarations in if statements act like
+// they have a block around them. Prohibited in strict mode.
+(function() {

[adamk, 2016/03/02 00:33:45]

Maybe add assertEquals(undefined, f) before the if statement to demonstrate that
hoisting is still going on.

[Dan Ehrenberg, 2016/03/02 00:49:54]

Done

+  if (false) function f() { };

[adamk, 2016/03/02 00:33:45]

What about if (true)? I assume that results in the function being visible later?

[Dan Ehrenberg, 2016/03/02 00:49:54]

Good point, added tests for this, and for the 'else' case.

+  assertEquals(undefined, f);
+})();
+
+assertThrows(`
+  function() {
+    'use strict';
+    if (true) function foo() {}
+  }
+`, SyntaxError);

[adamk, 2016/03/02 00:51:10]

All these parsing tests will better-exercise the parser in cctest/test-parsing.
At the moment I think you have no PreParser support at all. Please move the
tests to test-parsing, which should point the way towards the changes you need
in the PreParser.

[Dan Ehrenberg, 2016/03/03 02:32:57]

Oops, not sure how I completely forgot about the preparser! Moved a bunch of
these tests to cctest and implemented preparser support.

+
+// For legacy reasons, we also support these types of semantics as
+// the body of a for or with statement.
+(function() {
+  for (;false;) function f() { };
+  assertEquals(undefined, f);
+})();
+
+(function() {
+  for (var x in {}) function f() { };
+  assertEquals(undefined, f);
+})();
+
+(function() {
+  var x;
+  for (x in {}) function f() { };
+  assertEquals(undefined, f);
+})();
+
+(function() {
+  for (var i = 0; i < 1; i++) function f() { };
+  assertEquals('function', typeof f);
+})();
+
+(function() {
+  for (var x in {a: 1}) function f() { };
+  assertEquals('function', typeof f);
+})();
+
+(function() {
+  var x;
+  for (x in {a: 1}) function f() { };
+  assertEquals('function', typeof f);
+})();
+
+(function() {
+  with ({}) function f() { };
+  assertEquals('function', typeof f);
+})();
+
+(function() {
+  do function f() {} while (0);
+  assertEquals('function', typeof f);
+})();
+
+assertThrows(`
+  function() {
+    'use strict';
+    for (;false;) function foo() {}
+  }
+`, SyntaxError);
+
+assertThrows(`
+  function() {
+    'use strict';
+    for (var x in {}) function foo() {}
+  }
+`, SyntaxError);
+
+assertThrows(`
+  function() {
+    'use strict';
+    var x;
+    for (x in {}) function foo() {}
+  }
+`, SyntaxError);
+
+assertThrows(`
+  function() {
+    'use strict';
+    do function foo() {} while (0);
+  }
+`, SyntaxError);
+
+// Some contexts always throw for function declarations, even in sloppy mode
+
+assertThrows(`
+  function() {
+    try function foo() {} catch (e) {}
+  }
+`, SyntaxError);
+
+assertThrows(`
+  function() {
+    'use strict';
+    try function foo() {} catch (e) {}
+  }
+`, SyntaxError);