Bug 1428742 - use Value::toGCCellPtr and delegating ctr of GCCellPtr. r=jonco

Differential Revision: https://phabricator.services.mozilla.com/D103589

js/public/Value.h

@@ -20,6 +20,7 @@
 #include "js-config.h"
 #include "jstypes.h"
 
+#include "js/HeapAPI.h"
 #include "js/RootingAPI.h"
 #include "js/TypeDecls.h"
 
@@ -930,7 +931,7 @@ static MOZ_ALWAYS_INLINE void ExposeValueToActiveJS(const Value& v) {
   MOZ_ASSERT(!js::gc::EdgeNeedsSweepUnbarrieredSlow(&tmp));
 #endif
   if (v.isGCThing()) {
-    js::gc::ExposeGCThingToActiveJS(GCCellPtr(v));
+    js::gc::ExposeGCThingToActiveJS(v.toGCCellPtr());
   }
 }
 
@@ -1162,6 +1163,7 @@ class WrappedPtrOperations<JS::Value, Wrapper> {
   JS::BigInt* toBigInt() const { return value().toBigInt(); }
   JSObject& toObject() const { return value().toObject(); }
   JSObject* toObjectOrNull() const { return value().toObjectOrNull(); }
+  JS::GCCellPtr toGCCellPtr() const { return value().toGCCellPtr(); }
   gc::Cell* toGCThing() const { return value().toGCThing(); }
   JS::TraceKind traceKind() const { return value().traceKind(); }
   void* toPrivate() const { return value().toPrivate(); }

js/src/gc/GC.cpp

@@ -235,6 +235,7 @@
 #include "jit/JitRuntime.h"
 #include "jit/JitZone.h"
 #include "jit/MacroAssembler.h"  // js::jit::CodeAlignment
+#include "js/HeapAPI.h"          // JS::GCCellPtr
 #include "js/Object.h"           // JS::GetClass
 #include "js/SliceBudget.h"
 #include "proxy/DeadObjectProxy.h"
@@ -8307,37 +8308,8 @@ JS_FRIEND_API size_t JS::GCTraceKindSize(JS::TraceKind kind) {
   }
 }
 
-JS::GCCellPtr::GCCellPtr(const Value& v) : ptr(0) {
-  switch (v.type()) {
-    case ValueType::String:
-      ptr = checkedCast(v.toString(), JS::TraceKind::String);
-      return;
-    case ValueType::Object:
-      ptr = checkedCast(&v.toObject(), JS::TraceKind::Object);
-      return;
-    case ValueType::Symbol:
-      ptr = checkedCast(v.toSymbol(), JS::TraceKind::Symbol);
-      return;
-    case ValueType::BigInt:
-      ptr = checkedCast(v.toBigInt(), JS::TraceKind::BigInt);
-      return;
-    case ValueType::PrivateGCThing:
-      ptr = checkedCast(v.toGCThing(), v.toGCThing()->getTraceKind());
-      return;
-    case ValueType::Double:
-    case ValueType::Int32:
-    case ValueType::Boolean:
-    case ValueType::Undefined:
-    case ValueType::Null:
-    case ValueType::Magic: {
-      MOZ_ASSERT(!v.isGCThing());
-      ptr = checkedCast(nullptr, JS::TraceKind::Null);
-      return;
-    }
-  }
-
-  ReportBadValueTypeAndCrash(v);
-}
+JS::GCCellPtr::GCCellPtr(const Value& v)
+    : GCCellPtr(v.toGCThing(), v.traceKind()) {}
 
 JS::TraceKind JS::GCCellPtr::outOfLineKind() const {
   MOZ_ASSERT((ptr & OutOfLineTraceKindMask) == OutOfLineTraceKindMask);

js/src/jsapi-tests/testGCCellPtr.cpp

@@ -35,11 +35,11 @@ BEGIN_TEST(testGCCellPtr) {
 
   CHECK(JS::GCCellPtr(obj.get()));
   CHECK(JS::GCCellPtr(obj.get()).kind() == JS::TraceKind::Object);
-  CHECK(JS::GCCellPtr(JS::ObjectValue(*obj)).kind() == JS::TraceKind::Object);
+  CHECK(JS::ObjectValue(*obj).toGCCellPtr().kind() == JS::TraceKind::Object);
 
   CHECK(JS::GCCellPtr(str.get()));
   CHECK(JS::GCCellPtr(str.get()).kind() == JS::TraceKind::String);
-  CHECK(JS::GCCellPtr(JS::StringValue(str)).kind() == JS::TraceKind::String);
+  CHECK(JS::StringValue(str).toGCCellPtr().kind() == JS::TraceKind::String);
 
   CHECK(JS::GCCellPtr(script.get()));
   CHECK(!JS::GCCellPtr(nullptr));

js/src/vm/ProxyObject.cpp

@@ -162,7 +162,7 @@ void ProxyObject::setSameCompartmentPrivate(const Value& priv) {
 
 inline void ProxyObject::setPrivate(const Value& priv) {
   MOZ_ASSERT_IF(IsMarkedBlack(this) && priv.isGCThing(),
-                !JS::GCThingIsMarkedGray(JS::GCCellPtr(priv)));
+                !JS::GCThingIsMarkedGray(priv.toGCCellPtr()));
   *slotOfPrivate() = priv;
 }
 

js/xpconnect/src/XPCVariant.cpp

@@ -77,7 +77,7 @@ NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(XPCVariant)
   JS::Value val = tmp->GetJSValPreserveColor();
   if (val.isObject()) {
     NS_CYCLE_COLLECTION_NOTE_EDGE_NAME(cb, "mJSVal");
-    cb.NoteJSChild(JS::GCCellPtr(val));
+    cb.NoteJSChild(val.toGCCellPtr());
   }
 
   tmp->mData.Traverse(cb);

xpcom/base/nsCycleCollectorTraceJSHelpers.cpp

@@ -34,7 +34,7 @@ void nsCycleCollectionParticipant::NoteJSChild(JS::GCCellPtr aGCThing,
 void TraceCallbackFunc::Trace(JS::Heap<JS::Value>* aPtr, const char* aName,
                               void* aClosure) const {
   if (aPtr->unbarrieredGet().isGCThing()) {
-    mCallback(JS::GCCellPtr(aPtr->unbarrieredGet()), aName, aClosure);
+    mCallback(aPtr->unbarrieredGet().toGCCellPtr(), aName, aClosure);
   }
 }