From 5e6632a42b53ae7306af1a6b84f741f6c488e686 Mon Sep 17 00:00:00 2001
From: Jon Coppeard <jcoppeard@mozilla.com>
Date: Thu, 13 Jun 2024 07:33:54 +0000
Subject: [PATCH] Bug 1896973 - Part 1: Tidy some JS::Heap methods r=sfink

This renames address() and unsafeGet() methods to be const and non-const
versions of unsafeAddress.

The unnecessary operator bool() overload is removed.

Differential Revision: https://phabricator.services.mozilla.com/D212260
---
 dom/bindings/BindingUtils.cpp     |  2 +-
 dom/bindings/Codegen.py           |  2 +-
 dom/promise/Promise-inl.h         |  2 +-
 js/public/RootingAPI.h            | 14 +++-----------
 js/public/TracingAPI.h            |  2 +-
 js/src/gc/Marking.cpp             |  2 +-
 js/xpconnect/src/XPCWrappedJS.cpp |  2 +-
 7 files changed, 9 insertions(+), 17 deletions(-)

diff --git a/dom/bindings/BindingUtils.cpp b/dom/bindings/BindingUtils.cpp
index 198db3b5e2b5..6790fe1bc436 100644
--- a/dom/bindings/BindingUtils.cpp
+++ b/dom/bindings/BindingUtils.cpp
@@ -4239,7 +4239,7 @@ JS::Handle<JSObject*> GetPerInterfaceObjectHandle(
   const JS::Heap<JSObject*>& entrySlot =
       protoAndIfaceCache.EntrySlotMustExist(aSlotId);
   JS::AssertObjectIsNotGray(entrySlot);
-  return JS::Handle<JSObject*>::fromMarkedLocation(entrySlot.address());
+  return JS::Handle<JSObject*>::fromMarkedLocation(entrySlot.unsafeAddress());
 }
 
 namespace binding_detail {
diff --git a/dom/bindings/Codegen.py b/dom/bindings/Codegen.py
index 59b711f3010a..9723a1546e52 100644
--- a/dom/bindings/Codegen.py
+++ b/dom/bindings/Codegen.py
@@ -3883,7 +3883,7 @@ class CGCreateInterfaceObjectsMethod(CGAbstractMethod):
                 fill(
                     """
                 JS::AssertObjectIsNotGray(*protoCache);
-                JS::Handle<JSObject*> proto = JS::Handle<JSObject*>::fromMarkedLocation(protoCache->address());
+                JS::Handle<JSObject*> proto = JS::Handle<JSObject*>::fromMarkedLocation(protoCache->unsafeAddress());
                 if (!proto) {
                   $*{failureCode}
                 }
diff --git a/dom/promise/Promise-inl.h b/dom/promise/Promise-inl.h
index a7a6ebd0fdbe..e9a9f22c45ed 100644
--- a/dom/promise/Promise-inl.h
+++ b/dom/promise/Promise-inl.h
@@ -195,7 +195,7 @@ class NativeThenHandler<ResolveCallback, RejectCallback, std::tuple<Args...>,
   template <typename T>
   static JS::Handle<T> GetJSArgHandleForCall(JS::Heap<T>& aArg) {
     aArg.exposeToActiveJS();
-    return JS::Handle<T>::fromMarkedLocation(aArg.address());
+    return JS::Handle<T>::fromMarkedLocation(aArg.unsafeAddress());
   }
 
   template <typename TCallback, size_t... Indices, size_t... JSIndices>
diff --git a/js/public/RootingAPI.h b/js/public/RootingAPI.h
index eaae2db1b7e1..9ced6b56413d 100644
--- a/js/public/RootingAPI.h
+++ b/js/public/RootingAPI.h
@@ -343,8 +343,6 @@ class MOZ_NON_MEMMOVABLE Heap : public js::HeapOperations<T, Heap<T>> {
   DECLARE_POINTER_CONSTREF_OPS(T);
   DECLARE_POINTER_ASSIGN_OPS(Heap, T);
 
-  const T* address() const { return &ptr; }
-
   void exposeToActiveJS() const { js::BarrierMethods<T>::exposeToJS(ptr); }
 
   const T& get() const {
@@ -362,17 +360,14 @@ class MOZ_NON_MEMMOVABLE Heap : public js::HeapOperations<T, Heap<T>> {
     ptr = newPtr;
     postWriteBarrier(tmp, ptr);
   }
-
-  T* unsafeGet() { return &ptr; }
-
   void unbarrieredSet(const T& newPtr) { ptr = newPtr; }
 
+  T* unsafeAddress() { return &ptr; }
+  const T* unsafeAddress() const { return &ptr; }
+
   explicit operator bool() const {
     return bool(js::BarrierMethods<T>::asGCThingOrNull(ptr));
   }
-  explicit operator bool() {
-    return bool(js::BarrierMethods<T>::asGCThingOrNull(ptr));
-  }
 
  private:
   void postWriteBarrier(const T& prev, const T& next) {
@@ -526,9 +521,6 @@ class TenuredHeap : public js::HeapOperations<T, TenuredHeap<T>> {
   explicit operator bool() const {
     return bool(js::BarrierMethods<T>::asGCThingOrNull(unbarrieredGetPtr()));
   }
-  explicit operator bool() {
-    return bool(js::BarrierMethods<T>::asGCThingOrNull(unbarrieredGetPtr()));
-  }
 
   TenuredHeap<T>& operator=(T p) {
     setPtr(p);
diff --git a/js/public/TracingAPI.h b/js/public/TracingAPI.h
index 4db1b0a30ca5..72a043718f71 100644
--- a/js/public/TracingAPI.h
+++ b/js/public/TracingAPI.h
@@ -348,7 +348,7 @@ template <typename T>
 inline void TraceEdge(JSTracer* trc, JS::Heap<T>* thingp, const char* name) {
   MOZ_ASSERT(thingp);
   if (*thingp) {
-    js::gc::TraceExternalEdge(trc, thingp->unsafeGet(), name);
+    js::gc::TraceExternalEdge(trc, thingp->unsafeAddress(), name);
   }
 }
 
diff --git a/js/src/gc/Marking.cpp b/js/src/gc/Marking.cpp
index c53fbb62b417..ccad6a817ad1 100644
--- a/js/src/gc/Marking.cpp
+++ b/js/src/gc/Marking.cpp
@@ -2607,7 +2607,7 @@ namespace js::gc {
 
 template <typename T>
 JS_PUBLIC_API bool TraceWeakEdge(JSTracer* trc, JS::Heap<T>* thingp) {
-  return TraceEdgeInternal(trc, gc::ConvertToBase(thingp->unsafeGet()),
+  return TraceEdgeInternal(trc, gc::ConvertToBase(thingp->unsafeAddress()),
                            "JS::Heap edge");
 }
 
diff --git a/js/xpconnect/src/XPCWrappedJS.cpp b/js/xpconnect/src/XPCWrappedJS.cpp
index d01c8016002e..36ec8b47c76e 100644
--- a/js/xpconnect/src/XPCWrappedJS.cpp
+++ b/js/xpconnect/src/XPCWrappedJS.cpp
@@ -615,7 +615,7 @@ void nsXPCWrappedJS::SystemIsBeingShutDown() {
   // containing mJSObj, which may have been freed at this point. This is safe
   // if we are not currently running an incremental GC.
   MOZ_ASSERT(!JS::IsIncrementalGCInProgress(xpc_GetSafeJSContext()));
-  *mJSObj.unsafeGet() = nullptr;
+  mJSObj.unbarrieredSet(nullptr);
   if (isInList()) {
     remove();
   }