[vm/kernel/bytecode] Support partial tear-off instantiation constants…

… in bytecode generator and bytecode reader

Change-Id: I24855274df292903646844bb56ece0c35a62e9ef
Reviewed-on: https://dart-review.googlesource.com/68300
Reviewed-by: Régis Crelier <regis@google.com>
Commit-Queue: Alexander Markov <alexmarkov@google.com>

pkg/vm/lib/bytecode/constant_pool.dart

@@ -162,6 +162,12 @@ type ConstantSubtypeTestCache extends ConstantPoolEntry {
   Byte tag = 24;
 }
 
+type ConstantPartialTearOffInstantiation extends ConstantPoolEntry {
+  Byte tag = 25;
+  ConstantIndex tearOffConstant;
+  ConstantIndex typeArguments;
+}
+
 */
 
 enum ConstantTag {
@@ -190,6 +196,7 @@ enum ConstantTag {
   kEndClosureFunctionScope,
   kNativeEntry,
   kSubtypeTestCache,
+  kPartialTearOffInstantiation
 }
 
 abstract class ConstantPoolEntry {
@@ -258,6 +265,8 @@ abstract class ConstantPoolEntry {
         return new ConstantNativeEntry.readFromBinary(source);
       case ConstantTag.kSubtypeTestCache:
         return new ConstantSubtypeTestCache.readFromBinary(source);
+      case ConstantTag.kPartialTearOffInstantiation:
+        return new ConstantPartialTearOffInstantiation.readFromBinary(source);
     }
     throw 'Unexpected constant tag $tag';
   }
@@ -1088,6 +1097,42 @@ class ConstantSubtypeTestCache extends ConstantPoolEntry {
   bool operator ==(other) => identical(this, other);
 }
 
+class ConstantPartialTearOffInstantiation extends ConstantPoolEntry {
+  final int tearOffConstantIndex;
+  final int typeArgumentsConstantIndex;
+
+  ConstantPartialTearOffInstantiation(
+      this.tearOffConstantIndex, this.typeArgumentsConstantIndex);
+
+  @override
+  ConstantTag get tag => ConstantTag.kPartialTearOffInstantiation;
+
+  @override
+  void writeValueToBinary(BinarySink sink) {
+    sink.writeUInt30(tearOffConstantIndex);
+    sink.writeUInt30(typeArgumentsConstantIndex);
+  }
+
+  ConstantPartialTearOffInstantiation.readFromBinary(BinarySource source)
+      : tearOffConstantIndex = source.readUInt(),
+        typeArgumentsConstantIndex = source.readUInt();
+
+  @override
+  String toString() {
+    return 'PartialTearOffInstantiation tear-off CP#$tearOffConstantIndex type-args CP#$typeArgumentsConstantIndex';
+  }
+
+  @override
+  int get hashCode =>
+      _combineHashes(tearOffConstantIndex, typeArgumentsConstantIndex);
+
+  @override
+  bool operator ==(other) =>
+      other is ConstantPartialTearOffInstantiation &&
+      this.tearOffConstantIndex == other.tearOffConstantIndex &&
+      this.typeArgumentsConstantIndex == other.typeArgumentsConstantIndex;
+}
+
 class ConstantPool {
   final List<ConstantPoolEntry> entries = <ConstantPoolEntry>[];
   final Map<ConstantPoolEntry, int> _canonicalizationCache =

pkg/vm/lib/bytecode/gen_bytecode.dart

@@ -2457,6 +2457,12 @@ class ConstantEmitter extends ConstantVisitor<int> {
   @override
   int visitTypeLiteralConstant(TypeLiteralConstant node) =>
       cp.add(new ConstantType(node.type));
+
+  @override
+  int visitPartialInstantiationConstant(PartialInstantiationConstant node) =>
+      cp.add(new ConstantPartialTearOffInstantiation(
+          node.tearOffConstant.accept(this),
+          cp.add(new ConstantTypeArguments(node.types))));
 }
 
 class UnsupportedOperationError {

runtime/vm/compiler/frontend/bytecode_reader.cc

@@ -113,6 +113,7 @@ intptr_t BytecodeMetadataHelper::ReadPoolEntries(const Function& function,
     kEndClosureFunctionScope,
     kNativeEntry,
     kSubtypeTestCache,
+    kPartialTearOffInstantiation,
   };
 
   enum InvocationKind {
@@ -458,6 +459,25 @@ intptr_t BytecodeMetadataHelper::ReadPoolEntries(const Function& function,
       case ConstantPoolTag::kSubtypeTestCache: {
         obj = SubtypeTestCache::New();
       } break;
+      case ConstantPoolTag::kPartialTearOffInstantiation: {
+        intptr_t tearoff_index = helper_->ReadUInt();
+        ASSERT(tearoff_index < i);
+        const Closure& old_closure = Closure::CheckedHandle(
+            helper_->zone_, pool.ObjectAt(tearoff_index));
+
+        intptr_t type_args_index = helper_->ReadUInt();
+        ASSERT(type_args_index < i);
+        type_args ^= pool.ObjectAt(type_args_index);
+
+        obj = Closure::New(
+            TypeArguments::Handle(helper_->zone_,
+                                  old_closure.instantiator_type_arguments()),
+            TypeArguments::Handle(helper_->zone_,
+                                  old_closure.function_type_arguments()),
+            type_args, Function::Handle(helper_->zone_, old_closure.function()),
+            Context::Handle(helper_->zone_, old_closure.context()), Heap::kOld);
+        obj = H.Canonicalize(Instance::Cast(obj));
+      } break;
       default:
         UNREACHABLE();
     }