[VM/nnbd] Remove propagation of library mode to runtime after spec change.

On 1/27/20, the nnbd specification changed weak and strong mode instance checks
to make them behave uniformly across legacy and opted-in libraries.
Therefore, it is not necessary anymore to propagate the library mode in
generated code to the runtime.

Change-Id: I42d3ddc6e9a921899aeac21be6374c7893a6d27c
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/138111
Reviewed-by: Alexander Markov <alexmarkov@google.com>
Commit-Queue: Régis Crelier <regis@google.com>

Author: crelier

pkg/vm/lib/bytecode/dbc.dart

@@ -674,8 +674,3 @@ const int argumentsLimit = 1 << 8;
 // Base class for exceptions thrown when certain limit of bytecode
 // format is exceeded.
 abstract class BytecodeLimitExceededException {}
-
-// Constants specifying the NNBD mode of libraries.
-// Must be kept in sync with enum class NNBDMode in the VM.
-const int kLegacy = 0;
-const int kOptedIn = 1;

pkg/vm/lib/bytecode/gen_bytecode.dart

@@ -1272,11 +1272,6 @@ class BytecodeGenerator extends RecursiveVisitor<Null> {
     }
   }
 
-  void _genPushNnbdMode() {
-    asm.emitPushInt(
-        staticTypeContext.isNonNullableByDefault ? kOptedIn : kLegacy);
-  }
-
   Constant _getConstant(Expression expr) {
     if (expr is ConstantExpression) {
       return expr.constant;
@@ -1688,11 +1683,10 @@ class BytecodeGenerator extends RecursiveVisitor<Null> {
       asm.emitPushNull(); // Function type arguments.
     }
     asm.emitPushConstant(cp.addType(type));
-    _genPushNnbdMode();
-    final argDesc = objectTable.getArgDescHandle(5);
+    final argDesc = objectTable.getArgDescHandle(4);
     final cpIndex =
         cp.addInterfaceCall(InvocationKind.method, objectInstanceOf, argDesc);
-    asm.emitInterfaceCall(cpIndex, 5);
+    asm.emitInterfaceCall(cpIndex, 4);
   }
 
   void start(Member node, bool hasCode) {
@@ -2449,7 +2443,6 @@ class BytecodeGenerator extends RecursiveVisitor<Null> {
     final DartType bound = (forwardingTypeParameterBounds != null)
         ? forwardingTypeParameterBounds[typeParam]
         : typeParam.bound;
-    // TODO(regis): Revisit and take nnbdMode into consideration.
     final DartType type = new TypeParameterType(typeParam, Nullability.legacy);
     _genPushInstantiatorAndFunctionTypeArguments([type, bound]);
     asm.emitPushConstant(cp.addType(type));
@@ -2478,7 +2471,6 @@ class BytecodeGenerator extends RecursiveVisitor<Null> {
     _genPushInstantiatorAndFunctionTypeArguments([type]);
     asm.emitPushConstant(
         name != null ? cp.addName(name) : cp.addString(message));
-    // TODO(regis): Revisit and take nnbd mode into consideration.
     bool isIntOk = typeEnvironment.isSubtypeOf(
         typeEnvironment.coreTypes.intLegacyRawType,
         type,

pkg/vm/lib/bytecode/object_table.dart

@@ -763,7 +763,7 @@ class _NeverTypeHandle extends _TypeHandle {
       other is _NeverTypeHandle && this.nullability == other.nullability;
 
   @override
-  // TODO(regis): Print nullability, only if nnbd experiment is enabled?
+  // TODO(regis): Print nullability.
   String toString() => 'Never';
 }
 
@@ -803,7 +803,7 @@ class _SimpleTypeHandle extends _TypeHandle {
       this.nullability == other.nullability;
 
   @override
-  // TODO(regis): Print nullability, only if nnbd experiment is enabled?
+  // TODO(regis): Print nullability.
   String toString() => '$class_';
 }
 
@@ -857,7 +857,7 @@ class _TypeParameterHandle extends _TypeHandle {
       this.nullability == other.nullability;
 
   @override
-  // TODO(regis): Print nullability, only if nnbd experiment is enabled?
+  // TODO(regis): Print nullability.
   String toString() => '$parent::TypeParam/$indexInParent';
 }
 
@@ -903,7 +903,7 @@ class _GenericTypeHandle extends _TypeHandle {
       this.nullability == other.nullability;
 
   @override
-  // TODO(regis): Print nullability, only if nnbd experiment is enabled?
+  // TODO(regis): Print nullability.
   String toString() => '$class_ $typeArgs';
 }
 
@@ -956,7 +956,7 @@ class _RecursiveGenericTypeHandle extends _TypeHandle {
       this.nullability == other.nullability;
 
   @override
-  // TODO(regis): Print nullability, only if nnbd experiment is enabled?
+  // TODO(regis): Print nullability.
   String toString() => '(recursive #$id) $class_ $typeArgs';
 }
 
@@ -1009,7 +1009,7 @@ class NameAndType {
       this.type == other.type;
 
   @override
-  // TODO(regis): Print nullability, always or only if nnbd experiment is enabled?
+  // TODO(regis): Print nullability.
   String toString() => '$type ${name.name}';
 }
 
@@ -1152,7 +1152,7 @@ class _FunctionTypeHandle extends _TypeHandle {
       this.returnType == other.returnType;
 
   @override
-  // TODO(regis): Print nullability, only if nnbd experiment is enabled?
+  // TODO(regis): Print nullability.
   String toString() {
     StringBuffer sb = new StringBuffer();
     sb.write('FunctionType');

pkg/vm/testcases/bytecode/type_ops.dart.expect

@@ -31,8 +31,7 @@ L1:
   PushNull
   PushNull
   PushConstant         CP#6
-  PushInt              0
-  InterfaceCall        CP#7, 5
+  InterfaceCall        CP#7, 4
   JumpIfFalse          L2
   PushConstant         CP#9
   DirectCall           CP#4, 1
@@ -54,7 +53,7 @@ ConstantPool {
   [4] = DirectCall 'dart:core::print', ArgDesc num-args 1, num-type-args 0, names []
   [5] = Reserved
   [6] = Type #lib::C < dart:core::String, dart:core::int, dart:core::Object, dynamic >
-  [7] = InterfaceCall 'dart:core::Object::_instanceOf', ArgDesc num-args 5, num-type-args 0, names []
+  [7] = InterfaceCall 'dart:core::Object::_instanceOf', ArgDesc num-args 4, num-type-args 0, names []
   [8] = Reserved
   [9] = ObjectRef '12'
   [10] = Type #lib::A < dart:core::int >
@@ -222,8 +221,7 @@ Bytecode {
   LoadTypeArgumentsField CP#0
   PushNull
   PushConstant         CP#1
-  PushInt              0
-  InterfaceCall        CP#2, 5
+  InterfaceCall        CP#2, 4
   JumpIfFalse          L1
   PushConstant         CP#4
   DirectCall           CP#5, 1
@@ -234,8 +232,7 @@ L1:
   LoadTypeArgumentsField CP#0
   PushNull
   PushConstant         CP#7
-  PushInt              0
-  InterfaceCall        CP#2, 5
+  InterfaceCall        CP#2, 4
   JumpIfFalse          L2
   PushConstant         CP#8
   DirectCall           CP#5, 1
@@ -257,7 +254,7 @@ L2:
 ConstantPool {
   [0] = TypeArgumentsField #lib::D
   [1] = Type #lib::A < #lib::D::TypeParam/0 >
-  [2] = InterfaceCall 'dart:core::Object::_instanceOf', ArgDesc num-args 5, num-type-args 0, names []
+  [2] = InterfaceCall 'dart:core::Object::_instanceOf', ArgDesc num-args 4, num-type-args 0, names []
   [3] = Reserved
   [4] = ObjectRef '21'
   [5] = DirectCall 'dart:core::print', ArgDesc num-args 1, num-type-args 0, names []
@@ -285,8 +282,7 @@ Bytecode {
   PushNull
   Push                 r0
   PushConstant         CP#0
-  PushInt              0
-  InterfaceCall        CP#1, 5
+  InterfaceCall        CP#1, 4
   JumpIfFalse          L1
   PushConstant         CP#3
   DirectCall           CP#4, 1
@@ -297,8 +293,7 @@ L1:
   LoadTypeArgumentsField CP#6
   Push                 r0
   PushConstant         CP#7
-  PushInt              0
-  InterfaceCall        CP#1, 5
+  InterfaceCall        CP#1, 4
   JumpIfFalse          L2
   PushConstant         CP#8
   DirectCall           CP#4, 1
@@ -316,7 +311,7 @@ L2:
 }
 ConstantPool {
   [0] = Type #lib::A < #lib::D::foo3::TypeParam/0 >
-  [1] = InterfaceCall 'dart:core::Object::_instanceOf', ArgDesc num-args 5, num-type-args 0, names []
+  [1] = InterfaceCall 'dart:core::Object::_instanceOf', ArgDesc num-args 4, num-type-args 0, names []
   [2] = Reserved
   [3] = ObjectRef '31'
   [4] = DirectCall 'dart:core::print', ArgDesc num-args 1, num-type-args 0, names []

runtime/bin/entrypoints_verification_test_extension.cc

@@ -61,7 +61,6 @@ void FailClosurizeConstructor(const char* name, Dart_Handle result) {
 }
 
 void TestFields(Dart_Handle target) {
-  // TODO(regis): Fix these tests, as a function type is not nullable.
   FAIL("fld0", Dart_GetField(target, Dart_NewStringFromCString("fld0")));
   FAIL("fld0",
        Dart_SetField(target, Dart_NewStringFromCString("fld0"), Dart_Null()));

runtime/lib/ffi.cc

@@ -278,8 +278,7 @@ DEFINE_NATIVE_ENTRY(Ffi_storePointer, 0, 3) {
 
   auto& new_value_type =
       AbstractType::Handle(zone, new_value.GetType(Heap::kNew));
-  if (!new_value_type.IsSubtypeOf(NNBDMode::kLegacyLib, pointer_type_arg,
-                                  Heap::kNew)) {
+  if (!new_value_type.IsSubtypeOf(pointer_type_arg, Heap::kNew)) {
     const String& error = String::Handle(String::NewFormatted(
         "New value (%s) is not a subtype of '%s'.",
         String::Handle(new_value_type.UserVisibleName()).ToCString(),

runtime/lib/mirrors.cc

@@ -713,8 +713,8 @@ static RawAbstractType* InstantiateType(const AbstractType& type,
     instantiator_type_args = instantiator.arguments();
   }
   AbstractType& result = AbstractType::Handle(type.InstantiateFrom(
-      NNBDMode::kLegacyLib, instantiator_type_args,
-      Object::null_type_arguments(), kAllFree, NULL, Heap::kOld));
+      instantiator_type_args, Object::null_type_arguments(), kAllFree, NULL,
+      Heap::kOld));
   ASSERT(result.IsFinalized());
   return result.Canonicalize();
 }
@@ -1483,8 +1483,8 @@ DEFINE_NATIVE_ENTRY(ClassMirror_invokeConstructor, 0, 5) {
       // type arguments of the type reflected by the class mirror.
       ASSERT(redirect_type.IsInstantiated(kFunctions));
       redirect_type ^= redirect_type.InstantiateFrom(
-          NNBDMode::kLegacyLib, type_arguments, Object::null_type_arguments(),
-          kNoneFree, NULL, Heap::kOld);
+          type_arguments, Object::null_type_arguments(), kNoneFree, NULL,
+          Heap::kOld);
       redirect_type ^= redirect_type.Canonicalize();
     }
 
@@ -1513,8 +1513,7 @@ DEFINE_NATIVE_ENTRY(ClassMirror_invokeConstructor, 0, 5) {
       ArgumentsDescriptor::New(kTypeArgsLen, args.Length(), arg_names));
 
   ArgumentsDescriptor args_descriptor(args_descriptor_array);
-  if (!redirected_constructor.AreValidArguments(NNBDMode::kLegacyLib,
-                                                args_descriptor, NULL)) {
+  if (!redirected_constructor.AreValidArguments(args_descriptor, NULL)) {
     external_constructor_name = redirected_constructor.name();
     ThrowNoSuchMethod(AbstractType::Handle(klass.RareType()),
                       external_constructor_name, explicit_args, arg_names,
@@ -1524,7 +1523,7 @@ DEFINE_NATIVE_ENTRY(ClassMirror_invokeConstructor, 0, 5) {
   }
   const Object& type_error =
       Object::Handle(redirected_constructor.DoArgumentTypesMatch(
-          NNBDMode::kLegacyLib, args, args_descriptor, type_arguments));
+          args, args_descriptor, type_arguments));
   if (!type_error.IsNull()) {
     Exceptions::PropagateError(Error::Cast(type_error));
     UNREACHABLE();
@@ -1764,7 +1763,7 @@ DEFINE_NATIVE_ENTRY(VariableMirror_type, 0, 2) {
 DEFINE_NATIVE_ENTRY(TypeMirror_subtypeTest, 0, 2) {
   GET_NON_NULL_NATIVE_ARGUMENT(AbstractType, a, arguments->NativeArgAt(0));
   GET_NON_NULL_NATIVE_ARGUMENT(AbstractType, b, arguments->NativeArgAt(1));
-  return Bool::Get(a.IsSubtypeOf(NNBDMode::kLegacyLib, b, Heap::kNew)).raw();
+  return Bool::Get(a.IsSubtypeOf(b, Heap::kNew)).raw();
 }
 
 #endif  // !DART_PRECOMPILED_RUNTIME

runtime/lib/object.cc

@@ -133,7 +133,7 @@ DEFINE_NATIVE_ENTRY(Object_haveSameRuntimeType, 0, 2) {
       .raw();
 }
 
-DEFINE_NATIVE_ENTRY(Object_instanceOf, 0, 5) {
+DEFINE_NATIVE_ENTRY(Object_instanceOf, 0, 4) {
   const Instance& instance =
       Instance::CheckedHandle(zone, arguments->NativeArgAt(0));
   const TypeArguments& instantiator_type_arguments =
@@ -142,11 +142,9 @@ DEFINE_NATIVE_ENTRY(Object_instanceOf, 0, 5) {
       TypeArguments::CheckedHandle(zone, arguments->NativeArgAt(2));
   const AbstractType& type =
       AbstractType::CheckedHandle(zone, arguments->NativeArgAt(3));
-  const NNBDMode nnbd_mode = static_cast<NNBDMode>(
-      Smi::CheckedHandle(zone, arguments->NativeArgAt(4)).Value());
   ASSERT(type.IsFinalized());
   const bool is_instance_of = instance.IsInstanceOf(
-      nnbd_mode, type, instantiator_type_arguments, function_type_arguments);
+      type, instantiator_type_arguments, function_type_arguments);
   if (FLAG_trace_type_checks) {
     const char* result_str = is_instance_of ? "true" : "false";
     OS::PrintErr("Native Object.instanceOf: result %s\n", result_str);
@@ -169,18 +167,8 @@ DEFINE_NATIVE_ENTRY(Object_simpleInstanceOf, 0, 2) {
       AbstractType::CheckedHandle(zone, arguments->NativeArgAt(1));
   ASSERT(type.IsFinalized());
   ASSERT(type.IsInstantiated());
-  // If the instance is not null, the result of _simpleInstanceOf does not
-  // depend on the nnbd mode, because we only check against a rare type,
-  // i.e. a class. However, we need to determine the correct nnbd mode when
-  // the instance is null.
-  // Since type literals are not imported, a legacy type indicates that the
-  // call originated in a legacy library. Note that the type test against a
-  // non-legacy type (even in a legacy library) such as dynamic, void, or Null
-  // yield the same result independently of the mode used.
-  NNBDMode mode =
-      type.IsLegacy() ? NNBDMode::kLegacyLib : NNBDMode::kOptedInLib;
   const bool is_instance_of = instance.IsInstanceOf(
-      mode, type, Object::null_type_arguments(), Object::null_type_arguments());
+      type, Object::null_type_arguments(), Object::null_type_arguments());
   return Bool::Get(is_instance_of).raw();
 }
 
@@ -247,8 +235,8 @@ static bool ExtractInterfaceTypeArgs(Zone* zone,
       if (!cur_interface_type_args.IsNull() &&
           !cur_interface_type_args.IsInstantiated()) {
         cur_interface_type_args = cur_interface_type_args.InstantiateFrom(
-            cur_cls.nnbd_mode(), instance_type_args,
-            Object::null_type_arguments(), kNoneFree, NULL, Heap::kNew);
+            instance_type_args, Object::null_type_arguments(), kNoneFree, NULL,
+            Heap::kNew);
       }
       if (ExtractInterfaceTypeArgs(zone, cur_interface_cls,
                                    cur_interface_type_args, interface_cls,
@@ -401,10 +389,8 @@ DEFINE_NATIVE_ENTRY(Internal_boundsCheckForPartialInstantiation, 0, 2) {
     ASSERT(!supertype.IsNull());
 
     // The supertype may not be instantiated.
-    // TODO(regis): What is the correct nnbd mode to use here?
     if (!AbstractType::InstantiateAndTestSubtype(
-            NNBDMode::kLegacyLib, &subtype, &supertype, instantiator_type_args,
-            function_type_args)) {
+            &subtype, &supertype, instantiator_type_args, function_type_args)) {
       // Throw a dynamic type error.
       TokenPosition location;
       {

runtime/vm/bootstrap_natives.h

@@ -22,7 +22,7 @@ namespace dart {
   V(Object_toString, 1)                                                        \
   V(Object_runtimeType, 1)                                                     \
   V(Object_haveSameRuntimeType, 2)                                             \
-  V(Object_instanceOf, 5)                                                      \
+  V(Object_instanceOf, 4)                                                      \
   V(Object_simpleInstanceOf, 2)                                                \
   V(Function_apply, 2)                                                         \
   V(Closure_equals, 2)                                                         \

runtime/vm/class_finalizer.cc

@@ -390,16 +390,14 @@ void ClassFinalizer::CheckRecursiveType(const Class& cls,
           !pending_arguments.IsSubvectorInstantiated(first_type_param,
                                                      num_type_params)) {
         const TypeArguments& instantiated_arguments = TypeArguments::Handle(
-            zone, arguments.InstantiateFrom(NNBDMode::kLegacyLib,
-                                            Object::null_type_arguments(),
+            zone, arguments.InstantiateFrom(Object::null_type_arguments(),
                                             Object::null_type_arguments(),
                                             kNoneFree, NULL, Heap::kNew));
         const TypeArguments& instantiated_pending_arguments =
-            TypeArguments::Handle(
-                zone, pending_arguments.InstantiateFrom(
-                          NNBDMode::kLegacyLib, Object::null_type_arguments(),
-                          Object::null_type_arguments(), kNoneFree, NULL,
-                          Heap::kNew));
+            TypeArguments::Handle(zone, pending_arguments.InstantiateFrom(
+                                            Object::null_type_arguments(),
+                                            Object::null_type_arguments(),
+                                            kNoneFree, NULL, Heap::kNew));
         // By using TypeEquality::kInSubtypeTest, we throw a wider net than
         // using canonical or syntactical equality and may reject more
         // problematic declarations.
@@ -625,8 +623,8 @@ void ClassFinalizer::FinalizeTypeArguments(const Class& cls,
             continue;
           }
           super_type_arg = super_type_arg.InstantiateFrom(
-              cls.nnbd_mode(), arguments, Object::null_type_arguments(),
-              kNoneFree, instantiation_trail, Heap::kOld);
+              arguments, Object::null_type_arguments(), kNoneFree,
+              instantiation_trail, Heap::kOld);
           if (super_type_arg.IsBeingFinalized()) {
             // The super_type_arg was instantiated from a type being finalized.
             // We need to finish finalizing its type arguments.
@@ -783,8 +781,8 @@ RawAbstractType* ClassFinalizer::FinalizeType(const Class& cls,
           const TypeArguments& instantiator_type_arguments =
               TypeArguments::Handle(zone, fun_type.arguments());
           signature = signature.InstantiateSignatureFrom(
-              scope_class.nnbd_mode(), instantiator_type_arguments,
-              Object::null_type_arguments(), kNoneFree, Heap::kOld);
+              instantiator_type_arguments, Object::null_type_arguments(),
+              kNoneFree, Heap::kOld);
           // Note that if instantiator_type_arguments contains type parameters,
           // as in F<K>, the signature is still uninstantiated (the typedef type
           // parameters were substituted in the signature with typedef type