Bug 1328423 - Add AutoAssertNoContentJS assertion (r=sfink)

MozReview-Commit-ID: KY1JwysGzno

js/src/jsfriendapi.cpp

@@ -1439,3 +1439,15 @@ js::detail::IsWindowSlow(JSObject* obj)
 {
     return obj->as<GlobalObject>().maybeWindowProxy();
 }
+
+AutoAssertNoContentJS::AutoAssertNoContentJS(JSContext* cx)
+  : context_(cx),
+    prevAllowContentJS_(cx->runtime()->allowContentJS_)
+{
+    cx->runtime()->allowContentJS_ = false;
+}
+
+AutoAssertNoContentJS::~AutoAssertNoContentJS()
+{
+    context_->runtime()->allowContentJS_ = prevAllowContentJS_;
+}

js/src/jsfriendapi.h

@@ -2865,6 +2865,17 @@ ToWindowIfWindowProxy(JSObject* obj);
 extern bool
 AddPluralRulesConstructor(JSContext* cx, JS::Handle<JSObject*> intl);
 
+class MOZ_STACK_CLASS JS_FRIEND_API(AutoAssertNoContentJS)
+{
+  public:
+    explicit AutoAssertNoContentJS(JSContext* cx);
+    ~AutoAssertNoContentJS();
+
+  private:
+    JSContext* context_;
+    bool prevAllowContentJS_;
+};
+
 } /* namespace js */
 
 class NativeProfiler

js/src/vm/Interpreter.cpp

@@ -364,6 +364,9 @@ js::RunScript(JSContext* cx, RunState& state)
     // Since any script can conceivably GC, make sure it's safe to do so.
     cx->runtime()->gc.verifyIsSafeToGC();
 
+    MOZ_DIAGNOSTIC_ASSERT(cx->compartment()->isSystem() ||
+                          cx->runtime()->allowContentJS());
+
     if (!Debugger::checkNoExecute(cx, state.script()))
         return false;
 

js/src/vm/Runtime.cpp

@@ -222,6 +222,7 @@ JSRuntime::JSRuntime(JSRuntime* parentRuntime)
     keepAtoms_(0),
     trustedPrincipals_(nullptr),
     beingDestroyed_(false),
+    allowContentJS_(true),
     atoms_(nullptr),
     atomsCompartment_(nullptr),
     staticStrings(nullptr),

js/src/vm/Runtime.h

@@ -62,6 +62,7 @@ namespace js {
 
 class PerThreadData;
 class ExclusiveContext;
+class AutoAssertNoContentJS;
 class AutoKeepAtoms;
 class EnterDebuggeeNoExecute;
 #ifdef JS_TRACE_LOGGING
@@ -1042,6 +1043,15 @@ struct JSRuntime : public JS::shadow::Runtime,
         return beingDestroyed_;
     }
 
+  private:
+    bool allowContentJS_;
+  public:
+    bool allowContentJS() const {
+        return allowContentJS_;
+    }
+
+    friend class js::AutoAssertNoContentJS;
+
   private:
     // Set of all atoms other than those in permanentAtoms and staticStrings.
     // Reading or writing this set requires the calling thread to have an