Preliminary Harmony weak maps API implementation.

src/bootstrapper.cc

Index: src/bootstrapper.cc
diff --git a/src/bootstrapper.cc b/src/bootstrapper.cc
index 8cca5614b002d3db55a3f1b09aef85b932b073c8..7a2bd57d424a42376c01d752224e9b569293385d 100644
--- a/src/bootstrapper.cc
+++ b/src/bootstrapper.cc
@@ -1680,6 +1680,11 @@ bool Genesis::InstallExperimentalNatives() {
                "native proxy.js") == 0) {
       if (!CompileExperimentalBuiltin(isolate(), i)) return false;
     }
+    if (FLAG_harmony_weakmaps &&
+        strcmp(ExperimentalNatives::GetScriptName(i).start(),
+               "native weakmap.js") == 0) {
+      if (!CompileExperimentalBuiltin(isolate(), i)) return false;
+    }
   }
 
   InstallExperimentalNativeFunctions();
@@ -2169,6 +2174,17 @@ Genesis::Genesis(Isolate* isolate,
     isolate->counters()->contexts_created_from_scratch()->Increment();
   }
 
+  // TODO(mstarzinger): Move this into Genesis::InitializeGlobal once we no
+  // longer need to live behind a flag, so WeakMap gets added to the snapshot.
+  Handle<JSObject> global = Handle<JSObject>(global_context()->global());
+  if (FLAG_harmony_weakmaps) {  // -- W e a k M a p

[rossberg, 2011/08/02 12:33:38]

Can you perhaps move this into a separate function InitializeExperimentalGlobal?

[Michael Starzinger, 2011/08/02 14:05:22]

Done. I suppose you meant InstallExperimentalNatives, right?

[rossberg, 2011/08/02 15:32:04]

Actually, no, I had in mind a new function that mirrors the role of
InitializeGlobal, but for the experimental stuff.

[Michael Starzinger, 2011/08/02 16:04:51]

Done.

+     Handle<JSFunction> weakmap_fun =
+        InstallFunction(global, "WeakMap", JS_WEAK_MAP_TYPE, JSWeakMap::kSize,
+                        isolate->initial_object_prototype(),
+                        Builtins::kIllegal, true);
+    //global_context()->set_weakmap_function(*weakmap_fun);

[danno, 2011/08/02 12:48:02]

Should this really be commented out? If the code isn't used, it's better to
remove it.

[Michael Starzinger, 2011/08/02 14:05:22]

Done.

+  }
+
   // Install experimental natives.
   if (!InstallExperimentalNatives()) return;