Bug 1140472 - Set an async stack when invoking promise handlers. r=bz

dom/bindings/test/test_promise_rejections_from_jsimplemented.html

@@ -84,9 +84,10 @@ https://bugzilla.mozilla.org/show_bug.cgi?id=1107592
                         "doTest@http://mochi.test:8888/tests/dom/bindings/test/test_promise_rejections_from_jsimplemented.html:79:6\n")),
       t.testPromiseWithDOMExceptionThrowingThenFunction().then(
           ensurePromiseFail.bind(null, 8),
-          checkExn.bind(null, 0, "NetworkError",
+          checkExn.bind(null, 85, "NetworkError",
                         "We are a third DOMException",
-                        DOMException.NETWORK_ERR, "", 8, "")),
+                        DOMException.NETWORK_ERR, ourFile, 8,
+                        "Async*doTest@http://mochi.test:8888/tests/dom/bindings/test/test_promise_rejections_from_jsimplemented.html:85:6\n")),
       t.testPromiseWithDOMExceptionThrowingThenable().then(
           ensurePromiseFail.bind(null, 9),
           checkExn.bind(null, 0, "TypeMismatchError",

dom/promise/Promise.cpp

@@ -77,7 +77,20 @@ protected:
       return NS_OK;
     }
 
-    mCallback->Call(cx, value);
+    JS::Rooted<JSObject*> asyncStack(cx, mPromise->mAllocationStack);
+    JS::Rooted<JSString*> asyncCause(cx, JS_NewStringCopyZ(cx, "Promise"));
+    if (!asyncCause) {
+      JS_ClearPendingException(cx);
+      return NS_ERROR_OUT_OF_MEMORY;
+    }
+
+    {
+      Maybe<JS::AutoSetAsyncStackForNewCalls> sas;
+      if (asyncStack) {
+        sas.emplace(cx, asyncStack, asyncCause);
+      }
+      mCallback->Call(cx, value);
+    }
 
     return NS_OK;
   }

dom/promise/Promise.h

@@ -62,6 +62,7 @@ class Promise : public nsISupports,
                 public SupportsWeakPtr<Promise>
 {
   friend class NativePromiseCallback;
+  friend class PromiseCallbackTask;
   friend class PromiseResolverTask;
   friend class PromiseTask;
   friend class PromiseReportRejectFeature;

testing/modules/Assert.jsm

@@ -107,7 +107,7 @@ Assert.AssertionError = function(options) {
   // The part of the stack that comes from this module is not interesting.
   let stack = Components.stack;
   do {
-    stack = stack.caller;
+    stack = stack.asyncCaller || stack.caller;
   } while(stack.filename && stack.filename.contains("Assert.jsm"))
   this.stack = stack;
 };