Put new global var semantics behind a flag until WebKit tests are cleaned up.

R=mstarzinger@chromium.org
BUG=
TEST=

Review URL: https://chromiumcodereview.appspot.com/10163003

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@11402 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/flag-definitions.h

@@ -132,6 +132,8 @@ public:
 
 // Flags for language modes and experimental language features.
 DEFINE_bool(use_strict, false, "enforce strict mode")
+DEFINE_bool(es52_globals, false,
+            "activate new semantics for global var declarations")
 
 DEFINE_bool(harmony_typeof, false, "enable harmony semantics for typeof")
 DEFINE_bool(harmony_scoping, false, "enable harmony block scoping")

src/runtime.cc

@@ -1300,7 +1300,10 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_DeclareGlobals) {
       // value of the variable if the property is already there.
       // Do the lookup locally only, see ES5 errata.
       LookupResult lookup(isolate);
-      global->LocalLookup(*name, &lookup);
+      if (FLAG_es52_globals)
+        global->LocalLookup(*name, &lookup);
+      else
+        global->Lookup(*name, &lookup);
       if (lookup.IsProperty()) {
         // We found an existing property. Unless it was an interceptor
         // that claims the property is absent, skip this declaration.

test/cctest/test-api.cc

@@ -12483,6 +12483,7 @@ THREADED_TEST(GetCallingContext) {
 // Check that a variable declaration with no explicit initialization
 // value does shadow an existing property in the prototype chain.
 THREADED_TEST(InitGlobalVarInProtoChain) {
+  i::FLAG_es52_globals = true;
   v8::HandleScope scope;
   LocalContext context;
   // Introduce a variable in the prototype chain.

test/cctest/test-decls.cc

@@ -521,6 +521,7 @@ class ExistsInPrototypeContext: public DeclarationContext {
 
 
 TEST(ExistsInPrototype) {
+  i::FLAG_es52_globals = true;
   HandleScope scope;
 
   // Sanity check to make sure that the holder of the interceptor
@@ -583,6 +584,7 @@ class AbsentInPrototypeContext: public DeclarationContext {
 
 
 TEST(AbsentInPrototype) {
+  i::FLAG_es52_globals = true;
   HandleScope scope;
 
   { AbsentInPrototypeContext context;

test/mjsunit/declare-locally.js

@@ -33,6 +33,8 @@
 // This exercises the code in runtime.cc in
 // DeclareGlobal...Locally().
 
+// Flags: --es52_globals
+
 this.__proto__.foo = 42;
 this.__proto__.bar = 87;
 

test/mjsunit/regress/regress-1119.js

@@ -28,6 +28,8 @@
 // Test runtime declaration of properties with var which are intercepted
 // by JS accessors.
 
+// Flags: --es52_globals
+
 this.__defineSetter__("x", function() { hasBeenInvoked = true; });
 this.__defineSetter__("y", function() { throw 'exception'; });
 

test/mjsunit/regress/regress-115452.js

@@ -27,6 +27,8 @@
 
 // Test that a function declaration cannot overwrite a read-only property.
 
+// Flags: --es52_globals
+
 function foobl() {}
 assertTrue(typeof this.foobl == "function");
 assertTrue(Object.getOwnPropertyDescriptor(this, "foobl").writable);

test/mjsunit/regress/regress-1170.js

@@ -25,6 +25,8 @@
 // (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: --es52_globals
+
 var setter_value = 0;
 
 this.__defineSetter__("a", function(v) { setter_value = v; });