Bug 814729 - Add getSelfHostedValue function to JS shell. r=shu

js/src/jscntxt.cpp

@@ -444,8 +444,7 @@ JSRuntime::cloneSelfHostedFunctionScript(JSContext *cx, Handle<PropertyName*> na
 }
 
 bool
-JSRuntime::cloneSelfHostedValue(JSContext *cx, Handle<PropertyName*> name, HandleObject holder,
-                                MutableHandleValue vp)
+JSRuntime::cloneSelfHostedValue(JSContext *cx, Handle<PropertyName*> name, MutableHandleValue vp)
 {
     RootedValue funVal(cx);
     if (!getUnclonedSelfHostedValue(cx, name, &funVal))
@@ -458,15 +457,15 @@ JSRuntime::cloneSelfHostedValue(JSContext *cx, Handle<PropertyName*> name, Handl
      */
     if (cx->global() == selfHostedGlobal_) {
         vp.set(funVal);
-    } else if (funVal.toObject().isFunction()){
+    } else if (funVal.isObject() && funVal.toObject().isFunction()) {
         RootedFunction fun(cx, funVal.toObject().toFunction());
         RootedObject clone(cx, CloneFunctionObject(cx, fun, cx->global(), fun->getAllocKind()));
         if (!clone)
             return false;
         vp.set(ObjectValue(*clone));
+    } else {
+        vp.set(UndefinedValue());
     }
-    DebugOnly<bool> ok = JS_DefinePropertyById(cx, holder, NameToId(name), vp, NULL, NULL, 0);
-    JS_ASSERT(ok);
     return true;
 }
 

js/src/jscntxt.h

@@ -560,7 +560,7 @@ struct JSRuntime : js::RuntimeFriendFields
     bool cloneSelfHostedFunctionScript(JSContext *cx, js::Handle<js::PropertyName*> name,
                                        js::Handle<JSFunction*> targetFun);
     bool cloneSelfHostedValue(JSContext *cx, js::Handle<js::PropertyName*> name,
-                              js::HandleObject holder, js::MutableHandleValue vp);
+                              js::MutableHandleValue vp);
 
     /* Base address of the native stack for the current thread. */
     uintptr_t           nativeStackBase;

js/src/shell/js.cpp

@@ -3582,6 +3582,23 @@ GetMaxArgs(JSContext *cx, unsigned arg, jsval *vp)
     return true;
 }
 
+static JSBool
+GetSelfHostedValue(JSContext *cx, unsigned argc, jsval *vp)
+{
+    CallArgs args = CallArgsFromVp(argc, vp);
+
+    if (argc != 1 || !args[0].isString()) {
+        JS_ReportErrorNumber(cx, my_GetErrorMessage, NULL, JSSMSG_INVALID_ARGS,
+                             "getSelfHostedValue");
+        return false;
+    }
+    RootedAtom srcAtom(cx, ToAtom(cx, args[0]));
+    if (!srcAtom)
+        return false;
+    RootedPropertyName srcName(cx, srcAtom->asPropertyName());
+    return cx->runtime->cloneSelfHostedValue(cx, srcName, args.rval());
+}
+
 static JSFunctionSpecWithHelp shell_functions[] = {
     JS_FN_HELP("version", Version, 0, 0,
 "version([number])",
@@ -3894,6 +3911,11 @@ static JSFunctionSpecWithHelp shell_functions[] = {
 "  rooting hazards. This is helpful to reduce the time taken when interpreting\n"
 "  heavily numeric code."),
 
+    JS_FN_HELP("getSelfHostedValue", GetSelfHostedValue, 1, 0,
+"getSelfHostedValue()",
+"  Get a self-hosted value by its name. Note that these values don't get \n"
+"  cached, so repeatedly getting the same value creates multiple distinct clones."),
+
     JS_FS_HELP_END
 };
 #ifdef MOZ_PROFILING

js/src/vm/GlobalObject.h

@@ -393,7 +393,11 @@ class GlobalObject : public JSObject
         if (HasDataProperty(cx, holder, id, value.address()))
             return true;
         Rooted<PropertyName*> rootedName(cx, name);
-        return cx->runtime->cloneSelfHostedValue(cx, rootedName, holder, value);
+        if (!cx->runtime->cloneSelfHostedValue(cx, rootedName, value))
+            return false;
+        mozilla::DebugOnly<bool> ok = JS_DefinePropertyById(cx, holder, id, value, NULL, NULL, 0);
+        JS_ASSERT(ok);
+        return true;
     }
 
     inline RegExpStatics *getRegExpStatics() const;