Introduce extended mode.

test/mjsunit/harmony/block-let-declaration.js

 // Copyright 2011 the V8 project authors. All rights reserved.
 // 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
@@ skipping 10 matching lines @@
 // 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.
 
 // Flags: --harmony-scoping
 
 // Test let declarations in various settings.
+// TODO(ES6): properly activate extended mode
+"use strict";
 
 // Global
 let x;
 let y = 2;
 const z = 4;
 
 // Block local
 {
   let y;
   let x = 3;
   const z = 5;
 }
 
 assertEquals(undefined, x);
 assertEquals(2,y);
 assertEquals(4,z);
 
 if (true) {
   let y;
   assertEquals(undefined, y);
 }
 
 // Invalid declarations are early errors in harmony mode and thus should trigger
 // an exception in eval code during parsing, before even compiling or executing
 // the code. Thus the generated function is not called here.
 function TestLocalThrows(str, expect) {
-  assertThrows("(function(){" + str + "})", expect);
+  assertThrows("(function(){ 'use strict'; " + str + "})", expect);
 }
 
 function TestLocalDoesNotThrow(str) {
-  assertDoesNotThrow("(function(){" + str + "})()");
+  assertDoesNotThrow("(function(){ 'use strict'; " + str + "})()");
 }
 
 // Test let declarations in statement positions.
 TestLocalThrows("if (true) let x;", SyntaxError);
 TestLocalThrows("if (true) {} else let x;", SyntaxError);
 TestLocalThrows("do let x; while (false)", SyntaxError);
 TestLocalThrows("while (false) let x;", SyntaxError);
 TestLocalThrows("label: let x;", SyntaxError);
 TestLocalThrows("for (;false;) let x;", SyntaxError);
 TestLocalThrows("switch (true) { case true: let x; }", SyntaxError);
@@ skipping 54 matching lines @@
 
 // Test function declarations in statement position in strict mode.
 TestLocalThrows("function f() { if (true) function g() {}", SyntaxError);
 TestLocalThrows("function f() { if (true) {} else function g() {}", SyntaxError);
 TestLocalThrows("function f() { do function g() {} while (false)", SyntaxError);
 TestLocalThrows("function f() { while (false) function g() {}", SyntaxError);
 TestLocalThrows("function f() { label: function g() {}", SyntaxError);
 TestLocalThrows("function f() { for (;false;) function g() {}", SyntaxError);
 TestLocalThrows("function f() { switch (true) { case true: function g() {} }", SyntaxError);
 TestLocalThrows("function f() { switch (true) { default: function g() {} }", SyntaxError);