[kernel,vm] First-class kernel serialization of FutureOrType and NullType

TEST=ci
Fixes https://github.com/dart-lang/sdk/issues/52565

Change-Id: I9906f2d10c7ed51d11a0c402b51c8189ac3b6298
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/306901
Commit-Queue: Alexander Markov <alexmarkov@google.com>
Reviewed-by: Chloe Stefantsova <cstefantsova@google.com>
Reviewed-by: Ryan Macnak <rmacnak@google.com>

pkg/kernel/binary.md

@@ -147,7 +147,7 @@ type CanonicalName {
 
 type ComponentFile {
   UInt32 magic = 0x90ABCDEF;
-  UInt32 formatVersion = 102;
+  UInt32 formatVersion = 103;
   Byte[10] shortSdkHash;
   List<String> problemsAsJson; // Described in problems.md.
   Library[] libraries;
@@ -1540,6 +1540,10 @@ type VoidType extends DartType {
   Byte tag = 92;
 }
 
+type NullType extends DartType {
+  Byte tag = 152;
+}
+
 type InterfaceType extends DartType {
   Byte tag = 93;
   Byte nullability; // Index into the Nullability enum above.
@@ -1633,6 +1637,12 @@ type TypedefType {
   List<DartType> typeArguments;
 }
 
+type FutureOrType extends DartType {
+  Byte tag = 107;
+  Byte nullability; // Index into the Nullability enum above.
+  DartType typeArgument;
+}
+
 type TypeParameter {
   // Note: there is no tag on TypeParameter
   Byte flags (isCovariantByClass);

pkg/kernel/lib/binary/ast_from_binary.dart

@@ -3817,6 +3817,8 @@ class BinaryBuilder {
         return _readInvalidType();
       case Tag.NeverType:
         return _readNeverType();
+      case Tag.NullType:
+        return _readNullType();
       case Tag.InlineType:
         return _readInlineType();
       case Tag.FunctionType:
@@ -3825,6 +3827,8 @@ class BinaryBuilder {
         return _readIntersectionType();
       case Tag.RecordType:
         return _readRecordType();
+      case Tag.FutureOrType:
+        return _readFutureOrType();
       default:
         throw fail('unexpected dart type tag: $tag');
     }
@@ -3853,19 +3857,14 @@ class BinaryBuilder {
     return NeverType.fromNullability(Nullability.values[nullabilityIndex]);
   }
 
+  DartType _readNullType() {
+    return const NullType();
+  }
+
   DartType _readInterfaceType() {
     int nullabilityIndex = readByte();
     Reference reference = readNonNullClassReference();
     List<DartType> typeArguments = readDartTypeList();
-    CanonicalName? canonicalName = reference.canonicalName;
-    if (canonicalName != null &&
-        canonicalName.name == "FutureOr" &&
-        canonicalName.parent!.name == "dart:async" &&
-        canonicalName.parent!.parent != null &&
-        canonicalName.parent!.parent!.isRoot) {
-      return new FutureOrType(
-          typeArguments.single, Nullability.values[nullabilityIndex]);
-    }
     return new InterfaceType.byReference(
         reference, Nullability.values[nullabilityIndex], typeArguments);
   }
@@ -3879,15 +3878,6 @@ class BinaryBuilder {
       throw 'Expected a class reference to be valid but was `null`.';
     }
 
-    // We check this before the cache to not return a wrong cached value for
-    // this special case.
-    if (!forSupertype &&
-        canonicalName.name == "Null" &&
-        canonicalName.parent!.name == "dart:core" &&
-        canonicalName.parent!.parent!.isRoot) {
-      return const NullType();
-    }
-
     // Check cache.
     final int cacheIndex =
         (classReferenceIndex - 1) * Nullability.values.length +
@@ -3905,6 +3895,12 @@ class BinaryBuilder {
     return result;
   }
 
+  DartType _readFutureOrType() {
+    int nullabilityIndex = readByte();
+    DartType typeArgument = readDartType();
+    return new FutureOrType(typeArgument, Nullability.values[nullabilityIndex]);
+  }
+
   DartType _readInlineType() {
     int nullabilityIndex = readByte();
     Reference reference = readNonNullInlineClassReference();

pkg/kernel/lib/binary/ast_to_binary.dart

@@ -2477,38 +2477,14 @@ class BinaryPrinter implements Visitor<void>, BinarySink {
 
   @override
   void visitFutureOrType(FutureOrType node) {
-    // TODO(cstefantsova): Remove special treatment of FutureOr when the VM
+    writeByte(Tag.FutureOrType);
-    // supports the new encoding: just write the tag.
-    assert(_knownCanonicalNameNonRootTops.isNotEmpty);
-    CanonicalName root = _knownCanonicalNameNonRootTops.first;
-    while (!root.isRoot) {
-      root = root.parent!;
-    }
-    CanonicalName canonicalNameOfFutureOr =
-        root.getChild("dart:async").getChild("FutureOr");
-    writeByte(Tag.InterfaceType);
     writeByte(node.declaredNullability.index);
-    checkCanonicalName(canonicalNameOfFutureOr);
-    writeUInt30(canonicalNameOfFutureOr.index + 1);
-    writeUInt30(1); // Type argument count.
     writeNode(node.typeArgument);
   }
 
   @override
   void visitNullType(NullType node) {
-    // TODO(cstefantsova): Remove special treatment of Null when the VM
+    writeByte(Tag.NullType);
-    // supports the new encoding: just write the tag.
-    assert(_knownCanonicalNameNonRootTops.isNotEmpty);
-    CanonicalName root = _knownCanonicalNameNonRootTops.first;
-    while (!root.isRoot) {
-      root = root.parent!;
-    }
-    CanonicalName canonicalNameOfNull =
-        root.getChild("dart:core").getChild("Null");
-    writeByte(Tag.SimpleInterfaceType);
-    writeByte(node.declaredNullability.index);
-    checkCanonicalName(canonicalNameOfNull);
-    writeUInt30(canonicalNameOfNull.index + 1);
   }
 
   @override

pkg/kernel/lib/binary/tag.dart

@@ -158,6 +158,7 @@ class Tag {
   // 104 is occupied by [RecordLiteral] (expression).
   // 105 is occupied by [ConstRecordLiteral] (expression).
   // 106 is occupied by [ConstantExpression].
+  static const int FutureOrType = 107;
 
   // 108 is occupied by [RedirectingFactory] (member).
   // 109 is occupied by [SetLiteral] (expression).
@@ -206,6 +207,8 @@ class Tag {
   static const int PatternAssignment = 150;
   static const int PatternVariableDeclaration = 151;
 
+  static const int NullType = 152;
+
   static const int SpecializedTagHighBits = 0xE0; // 0b11100000
   static const int SpecializedTagMask = 0xF8; //    0b11111000
   static const int SpecializedPayloadMask = 0x7; // 0b00000111
@@ -222,7 +225,7 @@ class Tag {
   /// Internal version of kernel binary format.
   /// Bump it when making incompatible changes in kernel binaries.
   /// Keep in sync with runtime/vm/kernel_binary.h, pkg/kernel/binary.md.
-  static const int BinaryFormatVersion = 102;
+  static const int BinaryFormatVersion = 103;
 }
 
 abstract class ConstantTag {

runtime/vm/compiler/frontend/kernel_fingerprints.cc

@@ -233,6 +233,7 @@ void KernelFingerprintHelper::CalculateDartTypeFingerprint() {
     case kInvalidType:
     case kDynamicType:
     case kVoidType:
+    case kNullType:
       // those contain nothing.
       break;
     case kNeverType:
@@ -280,6 +281,10 @@ void KernelFingerprintHelper::CalculateDartTypeFingerprint() {
       CalculateDartTypeFingerprint();  // read instantiated representation type.
       break;
     }
+    case kFutureOrType:
+      BuildHash(static_cast<uint32_t>(ReadNullability()));
+      CalculateDartTypeFingerprint();  // read type argument.
+      break;
     default:
       ReportUnexpectedTag("type", tag);
       UNREACHABLE();

runtime/vm/compiler/frontend/kernel_translation_helper.cc

@@ -2244,6 +2244,7 @@ void KernelReaderHelper::SkipDartType() {
     case kInvalidType:
     case kDynamicType:
     case kVoidType:
+    case kNullType:
       // those contain nothing.
       return;
     case kNeverType:
@@ -2292,6 +2293,10 @@ void KernelReaderHelper::SkipDartType() {
       SkipDartType();  // read left.
       SkipDartType();  // read right.
       return;
+    case kFutureOrType:
+      ReadNullability();
+      SkipDartType();  // read type argument.
+      break;
     default:
       ReportUnexpectedTag("type", tag);
       UNREACHABLE();
@@ -3205,6 +3210,9 @@ void TypeTranslator::BuildTypeInternal() {
                     .ToNullability(nullability, Heap::kOld);
       break;
     }
+    case kNullType:
+      result_ = IG->object_store()->null_type();
+      break;
     case kInterfaceType:
       BuildInterfaceType(false);
       break;
@@ -3229,6 +3237,9 @@ void TypeTranslator::BuildTypeInternal() {
     case kInlineType:
       BuildInlineType();
       break;
+    case kFutureOrType:
+      BuildFutureOrType();
+      break;
     default:
       helper_->ReportUnexpectedTag("type", tag);
       UNREACHABLE();
@@ -3275,6 +3286,27 @@ void TypeTranslator::BuildInterfaceType(bool simple) {
   }
 }
 
+void TypeTranslator::BuildFutureOrType() {
+  Nullability nullability = helper_->ReadNullability();
+  if (apply_canonical_type_erasure_ && nullability != Nullability::kNullable) {
+    nullability = Nullability::kLegacy;
+  }
+
+  const TypeArguments& type_arguments =
+      TypeArguments::Handle(Z, TypeArguments::New(1));
+  BuildTypeInternal();  // read type argument.
+  type_arguments.SetTypeAt(0, result_);
+
+  const Class& klass = Class::Handle(Z, IG->object_store()->future_or_class());
+  ASSERT(!klass.IsNull());
+
+  result_ = Type::New(klass, type_arguments, nullability);
+  result_ = result_.NormalizeFutureOrType(Heap::kOld);
+  if (finalize_) {
+    result_ = ClassFinalizer::FinalizeType(result_);
+  }
+}
+
 void TypeTranslator::BuildFunctionType(bool simple) {
   const intptr_t num_enclosing_type_arguments =
       active_class_->enclosing != nullptr

runtime/vm/compiler/frontend/kernel_translation_helper.h

@@ -1576,6 +1576,7 @@ class TypeTranslator {
   void BuildTypeParameterType();
   void BuildIntersectionType();
   void BuildInlineType();
+  void BuildFutureOrType();
 
   class TypeParameterScope {
    public:

runtime/vm/compiler/frontend/scope_builder.cc

@@ -1375,6 +1375,7 @@ void ScopeBuilder::VisitDartType() {
     case kInvalidType:
     case kDynamicType:
     case kVoidType:
+    case kNullType:
       // those contain nothing.
       return;
     case kNeverType:
@@ -1404,6 +1405,9 @@ void ScopeBuilder::VisitDartType() {
     case kInlineType:
       VisitInlineType();
       return;
+    case kFutureOrType:
+      VisitFutureOrType();
+      return;
     default:
       ReportUnexpectedTag("type", tag);
       UNREACHABLE();
@@ -1525,6 +1529,11 @@ void ScopeBuilder::VisitInlineType() {
   VisitDartType();  // read instantiated representation type.
 }
 
+void ScopeBuilder::VisitFutureOrType() {
+  helper_.ReadNullability();
+  VisitDartType();  // read type argument.
+}
+
 void ScopeBuilder::HandleLocalFunction(intptr_t parent_kernel_offset) {
   // "Peek" ahead into the function node
   const intptr_t offset = helper_.ReaderOffset();

runtime/vm/compiler/frontend/scope_builder.h

@@ -52,6 +52,7 @@ class ScopeBuilder {
   void VisitTypeParameterType();
   void VisitIntersectionType();
   void VisitInlineType();
+  void VisitFutureOrType();
   void HandleLocalFunction(intptr_t parent_kernel_offset);
 
   AbstractType& BuildAndVisitVariableType();

runtime/vm/compiler/recognized_methods_list.h

@@ -132,7 +132,7 @@ namespace dart {
     0xc40903ac)                                                                \
   V(_SuspendState, _clone, SuspendState_clone, 0xae1a40a0)                     \
   V(_SuspendState, _createAsyncCallbacks, SuspendState_createAsyncCallbacks,   \
-    0x5e84c091)                                                                \
+    0x86343257)                                                                \
   V(_SuspendState, _createAsyncStarCallback,                                   \
     SuspendState_createAsyncStarCallback, 0x98fb897c)                          \
   V(_SuspendState, _resume, SuspendState_resume, 0x5d7a8489)                   \
@@ -319,10 +319,10 @@ namespace dart {
   V(::, _getNativeField, GetNativeField, 0xa0139b85)                           \
   V(::, reachabilityFence, ReachabilityFence, 0x730f2b7f)                      \
   V(_Utf8Decoder, _scan, Utf8DecoderScan, 0xb99d2ee1)                          \
-  V(_Future, timeout, FutureTimeout, 0xe21f0bf8)                               \
+  V(_Future, timeout, FutureTimeout, 0xa0f743d4)                               \
-  V(Future, wait, FutureWait, 0x22f98225)                                      \
+  V(Future, wait, FutureWait, 0x295fe957)                                      \
   V(_RootZone, runUnary, RootZoneRunUnary, 0x64397ecb)                         \
-  V(_FutureListener, handleValue, FutureListenerHandleValue, 0xbf5d3892)       \
+  V(_FutureListener, handleValue, FutureListenerHandleValue, 0xec25d1b2)       \
   V(::, has63BitSmis, Has63BitSmis, 0xf61b56f1)                                \
   V(::, get:extensionStreamHasListener, ExtensionStreamHasListener, 0xfab46343)\
   V(_Smi, get:hashCode, Smi_hashCode, 0x75e0ccd2)                              \

runtime/vm/kernel_binary.h

@@ -18,7 +18,7 @@ namespace kernel {
 // package:kernel/binary.md.
 
 static const uint32_t kMagicProgramFile = 0x90ABCDEFu;
-static const uint32_t kSupportedKernelFormatVersion = 102;
+static const uint32_t kSupportedKernelFormatVersion = 103;
 
 // Keep in sync with package:kernel/lib/binary/tag.dart
 #define KERNEL_TAG_LIST(V)                                                     \
@@ -136,6 +136,7 @@ static const uint32_t kSupportedKernelFormatVersion = 102;
   V(RecordType, 100)                                                           \
   V(InlineType, 103)                                                           \
   V(ConstantExpression, 106)                                                   \
+  V(FutureOrType, 107)                                                         \
   V(InstanceGet, 118)                                                          \
   V(InstanceSet, 119)                                                          \
   V(InstanceInvocation, 120)                                                   \
@@ -171,6 +172,7 @@ static const uint32_t kSupportedKernelFormatVersion = 102;
   V(IfCaseStatement, 149)                                                      \
   V(PatternAssignment, 150)                                                    \
   V(PatternVariableDeclaration, 151)                                           \
+  V(NullType, 152)                                                             \
   V(SpecializedVariableGet, 224)                                               \
   V(SpecializedVariableSet, 232)                                               \
   V(SpecializedIntLiteral, 240)

runtime/vm/object.cc

@@ -2123,6 +2123,7 @@ ErrorPtr Object::Init(IsolateGroup* isolate_group,
     cls.set_num_type_arguments_unsafe(1);
     RegisterClass(cls, Symbols::FutureOr(), lib);
     pending_classes.Add(cls);
+    object_store->set_future_or_class(cls);
 
     cls = Class::New<SuspendState, RTN::SuspendState>(isolate_group);
     RegisterPrivateClass(cls, Symbols::_SuspendState(), lib);
@@ -2674,6 +2675,7 @@ ErrorPtr Object::Init(IsolateGroup* isolate_group,
     cls = Class::New<MirrorReference, RTN::MirrorReference>(isolate_group);
     cls = Class::New<UserTag, RTN::UserTag>(isolate_group);
     cls = Class::New<FutureOr, RTN::FutureOr>(isolate_group);
+    object_store->set_future_or_class(cls);
     cls = Class::New<TransferableTypedData, RTN::TransferableTypedData>(
         isolate_group);
   }

runtime/vm/object_store.h

@@ -114,6 +114,7 @@ class ObjectPointerVisitor;
   RW(Field, pragma_name)                                                       \
   RW(Field, pragma_options)                                                    \
   RW(Class, future_class)                                                      \
+  RW(Class, future_or_class)                                                   \
   RW(Class, completer_class)                                                   \
   RW(Class, one_byte_string_class)                                             \
   RW(Class, two_byte_string_class)                                             \