tor-browser

commit d8e3b23cd602a8fcd13221a42f31608b98e1256f
parent f3e968c5ec1d577d46b206b6e43a050e9ae6067a
Author: Matthew Gaudet <mgaudet@mozilla.com>
Date:   Wed,  1 Oct 2025 21:38:50 +0000

Bug 1983154 - Create MaybeGetPromiseAllocationSite r=arai

This is a more flexibile version

Differential Revision: https://phabricator.services.mozilla.com/D261177

Diffstat:
M
js/public/Promise.h
 | 
16
++++++++++++++++
M
js/src/vm/Runtime.cpp
 | 
35
+++++++++++++++++++++++------------

2 files changed, 39 insertions(+), 12 deletions(-)
diff --git a/js/public/Promise.h b/js/public/Promise.h
@@ -398,10 +398,26 @@ extern JS_PUBLIC_API bool SetSettledPromiseIsHandled(JSContext* cx,
 /**
  * Returns a js::SavedFrame linked list of the stack that lead to the given
  * Promise's allocation.
+ *
+ * The promise parameter here should be an unwrapped promise.
  */
 extern JS_PUBLIC_API JSObject* GetPromiseAllocationSite(
     JS::HandleObject promise);
 
+/**
+ * A more flexible version of the above: Handles the cases where
+ * 1. maybePromise is wrapped
+ * 2. maybePromise is null
+ * 3. maybePromise isn't actually a promise.
+ *
+ * Returns js::SavedFrame if the passed argument is a
+ * wrapped promise (that's not a dead object wrapper) and it
+ * has an allocation site.
+ */
+extern JS_PUBLIC_API JSObject*
+MaybeGetPromiseAllocationSiteFromPossiblyWrappedPromise(
+    JS::HandleObject maybePromise);
+
 extern JS_PUBLIC_API JSObject* GetPromiseResolutionSite(
     JS::HandleObject promise);
 
diff --git a/js/src/vm/Runtime.cpp b/js/src/vm/Runtime.cpp
@@ -576,6 +576,26 @@ bool JSRuntime::getHostDefinedData(JSContext* cx,
   return cx->jobQueue->getHostDefinedData(cx, data);
 }
 
+JS_PUBLIC_API JSObject*
+JS::MaybeGetPromiseAllocationSiteFromPossiblyWrappedPromise(
+    HandleObject promise) {
+  if (!promise) {
+    return nullptr;
+  }
+
+  JSObject* unwrappedPromise = promise;
+  // While the job object is guaranteed to be unwrapped, the promise
+  // might be wrapped. See the comments in EnqueuePromiseReactionJob in
+  // builtin/Promise.cpp for details.
+  if (IsWrapper(promise)) {
+    unwrappedPromise = UncheckedUnwrap(promise);
+  }
+  if (unwrappedPromise->is<PromiseObject>()) {
+    return unwrappedPromise->as<PromiseObject>().allocationSite();
+  }
+  return nullptr;
+}
+
 bool JSRuntime::enqueuePromiseJob(JSContext* cx, HandleFunction job,
                                   HandleObject promise,
                                   HandleObject hostDefinedData) {
@@ -583,23 +603,14 @@ bool JSRuntime::enqueuePromiseJob(JSContext* cx, HandleFunction job,
              "Must select a JobQueue implementation using JS::JobQueue "
              "or js::UseInternalJobQueues before using Promises");
 
-  RootedObject allocationSite(cx);
   if (promise) {
 #ifdef DEBUG
     AssertSameCompartment(job, promise);
 #endif
-
-    RootedObject unwrappedPromise(cx, promise);
-    // While the job object is guaranteed to be unwrapped, the promise
-    // might be wrapped. See the comments in EnqueuePromiseReactionJob in
-    // builtin/Promise.cpp for details.
-    if (IsWrapper(promise)) {
-      unwrappedPromise = UncheckedUnwrap(promise);
-    }
-    if (unwrappedPromise->is<PromiseObject>()) {
-      allocationSite = JS::GetPromiseAllocationSite(unwrappedPromise);
-    }
   }
+
+  RootedObject allocationSite(
+      cx, JS::MaybeGetPromiseAllocationSiteFromPossiblyWrappedPromise(promise));
   return cx->jobQueue->enqueuePromiseJob(cx, promise, job, allocationSite,
                                          hostDefinedData);
 }