Switch arrayPrototypeFind to use void *ctx as an integer instead of a…

… pointer

Summary:
Use void *ctx as an interger in arrayPrototypeFind so its value can be retained
through S/D. Add NumKinds in IterationKind for sanity check.

Reviewed By: avp

Differential Revision: D16189506

fbshipit-source-id: b63ab3d2f3c48a06212b199368ed65d73b182ba9

include/hermes/VM/IterationKind.h

@@ -15,6 +15,7 @@ enum class IterationKind {
   Key,
   Value,
   Entry,
+  NumKinds,
 };
 
 } // namespace vm

include/hermes/VM/JSMapImpl.h

@@ -236,6 +236,9 @@ class JSMapIteratorImpl final : public JSObject {
             value = arrHandle.getHermesValue();
             break;
           };
+          case IterationKind::NumKinds:
+            llvm_unreachable("Invalid iteration kind");
+            return HermesValue::encodeEmptyValue();
         }
       } else {
         // If the next element in the iterator is invalid, we have

lib/VM/JSArray.cpp

@@ -759,7 +759,7 @@ CallResult<HermesValue> JSArrayIterator::nextElement(
       // 16. If itemKind is "value", let result be elementValue.
       return createIterResultObject(runtime, valueHandle, false)
           .getHermesValue();
-    case IterationKind::Entry:
+    case IterationKind::Entry: {
       // 17. b. Let result be CreateArrayFromList(«index, elementValue»).
       auto resultRes = JSArray::create(runtime, 2, 2);
       if (LLVM_UNLIKELY(resultRes == ExecutionStatus::EXCEPTION)) {
@@ -770,6 +770,10 @@ CallResult<HermesValue> JSArrayIterator::nextElement(
       JSArray::setElementAt(result, runtime, 1, valueHandle);
       // 18. Return CreateIterResultObject(result, false).
       return createIterResultObject(runtime, result, false).getHermesValue();
+    }
+    case IterationKind::NumKinds:
+      llvm_unreachable("Invalid iteration kind");
+      return HermesValue::encodeEmptyValue();
   }
 
   llvm_unreachable("Invalid iteration kind");

lib/VM/JSLib/Array.cpp

@@ -314,7 +314,7 @@ Handle<JSObject> createArrayConstructor(Runtime *runtime) {
       arrayPrototype,
       Predefined::getSymbolID(Predefined::findIndex),
       // Pass a non-null pointer here to indicate we're finding the index.
-      reinterpret_cast<void *>(arrayPrototypeFind),
+      (void *)true,
       arrayPrototypeFind,
       1);
   defineMethod(
@@ -339,29 +339,25 @@ Handle<JSObject> createArrayConstructor(Runtime *runtime) {
       arrayPrototypeIncludes,
       1);
 
-  static IterationKind iterationKindKey = IterationKind::Key;
-  static IterationKind iterationKindValue = IterationKind::Value;
-  static IterationKind iterationKindEntry = IterationKind::Entry;
-
   defineMethod(
       runtime,
       arrayPrototype,
       Predefined::getSymbolID(Predefined::keys),
-      &iterationKindKey,
+      (void *)IterationKind::Key,
       arrayPrototypeIterator,
       0);
   defineMethod(
       runtime,
       arrayPrototype,
       Predefined::getSymbolID(Predefined::values),
-      &iterationKindValue,
+      (void *)IterationKind::Value,
       arrayPrototypeIterator,
       0);
   defineMethod(
       runtime,
       arrayPrototype,
       Predefined::getSymbolID(Predefined::entries),
-      &iterationKindEntry,
+      (void *)IterationKind::Entry,
       arrayPrototypeIterator,
       0);
 
@@ -3080,13 +3076,16 @@ arrayPrototypeIncludes(void *, Runtime *runtime, NativeArgs args) {
 
 static CallResult<HermesValue>
 arrayPrototypeIterator(void *ctx, Runtime *runtime, NativeArgs args) {
+  IterationKind kind = *reinterpret_cast<IterationKind *>(&ctx);
+  assert(
+      kind < IterationKind::NumKinds &&
+      "arrayPrototypeIterator with wrong kind");
   auto objRes = toObject(runtime, args.getThisHandle());
   if (LLVM_UNLIKELY(objRes == ExecutionStatus::EXCEPTION)) {
     return ExecutionStatus::EXCEPTION;
   }
   auto obj = runtime->makeHandle<JSObject>(*objRes);
-  return JSArrayIterator::create(
-      runtime, obj, *reinterpret_cast<IterationKind *>(ctx));
+  return JSArrayIterator::create(runtime, obj, kind);
 }
 
 /// ES6.0 22.1.2.1 Array.from ( items [ , mapfn [ , thisArg ] ] )