[dart2wasm] Allow dynamic modules to run without re-compiling or running TFA on main module.

Accomplishes this by serializing more metadata in the main module metadata:
1) Most of this new metadata is to have access to the main module's dispatch table from the dynamic modules, including ProcedureMetadataAttributes and the DispatchTable itself.
2) Indices to create correct calling names from the dynamic module into the main module (or into the global updateable functions "table").
3) Basic tree-shaking information about classes (e.g. did TFA fully delete a member or just delete its body).

Some metadata from TFA is still expected throughout the compiler. For dynamic modules, we create pessimistic versions of this information and attach it to the new Component.

All the same dynamic module tests that were passing (or failing) before are still in the same state. This significantly speeds up compilation of dynamic modules though as only necessary code is compiled and TFA is not run.

Change-Id: I109f53cf5dcbe6579c0f78e71ce7779d593455e9
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/415500
Reviewed-by: Martin Kustermann <[email protected]>

Author: natebiggs

pkg/dart2wasm/lib/class_info.dart

@@ -8,6 +8,7 @@ import 'package:kernel/ast.dart';
 import 'package:wasm_builder/wasm_builder.dart' as w;
 
 import 'dynamic_modules.dart';
+import 'serialization.dart';
 import 'translator.dart';
 
 /// Wasm struct field indices for fields that are accessed explicitly from Wasm
@@ -375,8 +376,8 @@ class ClassInfoCollector {
       }
 
       if (translator.isDynamicModule) {
-        final brandIndex =
-            translator.dynamicModuleInfo!.classMetadata[cls]?.brandIndex;
+        final brandIndex = translator
+            .dynamicModuleInfo!.metadata.classMetadata[cls]?.brandIndex;
         if (brandIndex != null) {
           translator.typesBuilder.addBrandTypeAssignment(struct, brandIndex);
         }
@@ -551,16 +552,20 @@ class ClassInfoCollector {
 
         final mainModuleConcreteRange =
             classIdNumbering.getConcreteClassIdRangeForMainModule(cls);
-        final dynamicModuleConcreteRange =
-            classIdNumbering.getConcreteClassIdRangeForDynamicModule(cls);
-
         // Only non-extendable classes can get here so they should only have
         // concrete implementations in either the main module or the dynamic
         // module, not both.
-        assert(mainModuleConcreteRange.isEmpty ||
-            dynamicModuleConcreteRange.isEmpty);
-        addRanges(mainModuleConcreteRange);
-        addRanges(dynamicModuleConcreteRange);
+        if (translator.isDynamicModule && mainModuleConcreteRange.isEmpty) {
+          final dynamicModuleConcreteRange =
+              classIdNumbering.getConcreteClassIdRangeForDynamicModule(cls);
+          assert(dynamicModuleConcreteRange.isNotEmpty);
+          addRanges(dynamicModuleConcreteRange);
+        } else {
+          assert(classIdNumbering
+              .getConcreteClassIdRangeForDynamicModule(cls)
+              .isEmpty);
+          addRanges(mainModuleConcreteRange);
+        }
       }
       final info = translator.classInfo[cls]!;
       info._repr = representation ?? info;
@@ -709,9 +714,9 @@ class ClassIdNumbering {
     final classIds = <Class, ClassId>{};
 
     if (translator.isDynamicModule) {
-      final savedMapping = translator.dynamicModuleInfo!.classMetadata;
-      savedMapping.forEach((cls, info) {
-        final classId = info.classId;
+      final savedMapping = translator.dynamicModuleInfo!.metadata.classMetadata;
+      savedMapping.forEach((cls, metadata) {
+        final classId = metadata.classId;
         classIds[cls] = AbsoluteClassId(classId);
         savedMaxClassId = max(savedMaxClassId ?? -2, classId);
         if (!cls.isAbstract && !cls.isAnonymousMixin) {
@@ -805,7 +810,9 @@ class ClassIdNumbering {
     }
 
     // Make a list of the depth-first pre-order traversal.
-    final dfsOrder = [...?translator.dynamicModuleInfo?.dfsOrderClassIds];
+    final dfsOrder = [
+      ...?translator.dynamicModuleInfo?.metadata.dfsOrderClassIds
+    ];
     final inDfsOrder = {...dfsOrder};
 
     // Maps any class to a dense range of concrete class ids that are subclasses
@@ -945,6 +952,17 @@ class Range {
     return Range._(start, end);
   }
 
+  void serialize(DataSerializer sink) {
+    sink.writeInt(start);
+    sink.writeInt(end);
+  }
+
+  factory Range.deserialize(DataDeserializer source) {
+    final start = source.readInt();
+    final end = source.readInt();
+    return Range(start, end);
+  }
+
   int get length => 1 + (end - start);
   bool get isEmpty => length == 0;
 

pkg/dart2wasm/lib/code_generator.dart

@@ -1828,8 +1828,14 @@ abstract class AstCodeGenerator
     w.ValueType? intrinsicResult = intrinsifier.generateEqualsIntrinsic(node);
     if (intrinsicResult != null) return intrinsicResult;
 
+    final leftType = translator.translateType(dartTypeOf(node.left));
     Member? singleTarget = translator.singleTarget(node);
-    if (singleTarget == translator.coreTypes.objectEquals) {
+    if (singleTarget == translator.coreTypes.objectEquals ||
+        // If leftType is not a Dart type (or builtin value type) then use
+        // reference equality (e.g. the vtable type is not a subtype of
+        // topType).
+        (leftType is w.RefType &&
+            !leftType.isSubtypeOf(translator.topInfo.nullableType))) {
       // Plain reference comparison
       translateExpression(node.left, w.RefType.eq(nullable: true));
       translateExpression(node.right, w.RefType.eq(nullable: true));
@@ -1924,64 +1930,51 @@ abstract class AstCodeGenerator
       void Function(w.FunctionType signature, ParameterInfo) pushArguments,
       {required bool useUncheckedEntry}) {
     assert(kind != _VirtualCallKind.Get || !useUncheckedEntry);
-    SelectorInfo selector = translator.dispatchTable.selectorForTarget(
-        interfaceTarget.referenceAs(
-            getter: kind.isGetter, setter: kind.isSetter));
+    final reference = interfaceTarget.referenceAs(
+        getter: kind.isGetter, setter: kind.isSetter);
+    final dispatchTable = translator.dispatchTableForTarget(reference);
+    SelectorInfo selector = dispatchTable.selectorForTarget(reference);
+    final signature = selector.signature;
     final name = selector.entryPointName(useUncheckedEntry);
     assert(selector.name == interfaceTarget.name.text);
 
-    pushReceiver(selector.signature);
-
-    SelectorTargets targets;
-
-    if (!translator.dynamicModuleSupportEnabled ||
-        b.module == translator.mainModule) {
-      targets =
-          selector.targets(unchecked: useUncheckedEntry, dynamicModule: false);
-    } else {
-      targets =
-          selector.targets(unchecked: useUncheckedEntry, dynamicModule: true);
-    }
-
-    final isDynamicModuleOverrideable = selector.isDynamicModuleOverrideable;
-    if (!isDynamicModuleOverrideable) {
-      w.ValueType? checkRanges(List<({Range range, Reference target})> ranges) {
-        if (ranges.length == 1) {
-          final target = translator.getFunctionEntry(ranges[0].target,
-              uncheckedEntry: useUncheckedEntry);
-          final signature = translator.signatureForDirectCall(target);
-          final paramInfo = translator.paramInfoForDirectCall(target);
-          pushArguments(signature, paramInfo);
-          return translator.outputOrVoid(call(target));
-        }
-        if (ranges.isEmpty) {
-          // Unreachable call
-          b.comment("Virtual call of $name with no targets"
-              " at ${node.location}");
-          pushArguments(selector.signature, selector.paramInfo);
-          for (int i = 0; i < selector.signature.inputs.length; ++i) {
-            b.drop();
-          }
-          b.block(const [], selector.signature.outputs);
-          b.unreachable();
-          b.end();
-          return translator.outputOrVoid(selector.signature.outputs);
+    pushReceiver(signature);
+
+    final targets = selector.targets(unchecked: useUncheckedEntry);
+    List<({Range range, Reference target})> targetRanges = targets.targetRanges;
+    List<({Range range, Reference target})> staticDispatchRanges =
+        targets.staticDispatchRanges;
+    if (!selector.isDynamicModuleOverrideable) {
+      if (targetRanges.length == 1) {
+        final target = translator.getFunctionEntry(targetRanges[0].target,
+            uncheckedEntry: useUncheckedEntry);
+        final directCallSignature = translator.signatureForDirectCall(target);
+        final paramInfo = translator.paramInfoForDirectCall(target);
+        pushArguments(directCallSignature, paramInfo);
+        return translator.outputOrVoid(call(target));
+      }
+      if (targetRanges.isEmpty) {
+        // Unreachable call
+        b.comment("Virtual call of $name with no targets"
+            " at ${node.location}");
+        pushArguments(signature, selector.paramInfo);
+        for (int i = 0; i < signature.inputs.length; ++i) {
+          b.drop();
         }
-        return null;
+        b.block(const [], signature.outputs);
+        b.unreachable();
+        b.end();
+        return translator.outputOrVoid(signature.outputs);
       }
-
-      final result = checkRanges(targets.targetRanges);
-      if (result != null) return result;
     }
 
     // Receiver is already on stack.
-    w.Local receiverVar = addLocal(selector.signature.inputs.first);
+    w.Local receiverVar = addLocal(signature.inputs.first);
     assert(!receiverVar.type.nullable);
     b.local_tee(receiverVar);
-    pushArguments(selector.signature, selector.paramInfo);
+    pushArguments(signature, selector.paramInfo);
 
-    if (targets.staticDispatchRanges.isNotEmpty) {
-      assert(!translator.dynamicModuleSupportEnabled);
+    if (staticDispatchRanges.isNotEmpty) {
       b.invoke(translator
           .getPolymorphicDispatchersForModule(b.module)
           .getPolymorphicDispatcher(selector,
@@ -1990,11 +1983,12 @@ abstract class AstCodeGenerator
       b.comment("Instance $kind of '$name'");
       b.local_get(receiverVar);
       translator.callDispatchTable(b, selector,
-          interfaceTarget: interfaceTarget,
-          useUncheckedEntry: useUncheckedEntry);
+          interfaceTarget: reference,
+          useUncheckedEntry: useUncheckedEntry,
+          table: dispatchTable);
     }
 
-    return translator.outputOrVoid(selector.signature.outputs);
+    return translator.outputOrVoid(signature.outputs);
   }
 
   @override
@@ -2102,7 +2096,7 @@ abstract class AstCodeGenerator
           () => visitThis(w.RefType.struct(nullable: false)));
       return w.RefType.def(closureStruct, nullable: false);
     }
-    return _directGet(target, ThisExpression(), () => null);
+    return _directGet(target, ThisExpression());
   }
 
   @override
@@ -2143,10 +2137,13 @@ abstract class AstCodeGenerator
       b.end(); // doneLabel
       return resultType;
     }
+
     Member? singleTarget = translator.singleTarget(node);
     if (singleTarget != null) {
-      return _directGet(singleTarget, node.receiver,
-          () => intrinsifier.generateInstanceGetterIntrinsic(node));
+      final intrinsic = intrinsifier.generateInstanceGetterIntrinsic(node);
+      if (intrinsic != null) return intrinsic;
+
+      return _directGet(singleTarget, node.receiver);
     } else {
       return _virtualCall(
           node,
@@ -2229,11 +2226,7 @@ abstract class AstCodeGenerator
     return translator.topInfo.nullableType;
   }
 
-  w.ValueType _directGet(
-      Member target, Expression receiver, w.ValueType? Function() intrinsify) {
-    w.ValueType? intrinsicResult = intrinsify();
-    if (intrinsicResult != null) return intrinsicResult;
-
+  w.ValueType _directGet(Member target, Expression receiver) {
     if (target is Field) {
       ClassInfo info = translator.classInfo[target.enclosingClass]!;
       int fieldIndex = translator.fieldIndex[target]!;

pkg/dart2wasm/lib/compile.dart

@@ -183,7 +183,8 @@ Future<CompilationResult> compileToModule(
 
   Component component = compilerResult!.component!;
   CoreTypes coreTypes = compilerResult.coreTypes!;
-  ClassHierarchy classHierarchy = compilerResult.classHierarchy!;
+  final classHierarchy =
+      ClassHierarchy(component, coreTypes) as ClosedWorldClassHierarchy;
   LibraryIndex libraryIndex = LibraryIndex(component, [
     "dart:_boxed_bool",
     "dart:_boxed_double",
@@ -222,12 +223,11 @@ Future<CompilationResult> compileToModule(
     moduleStrategy = DynamicMainModuleStrategy(
         component,
         coreTypes,
-        classHierarchy,
         File.fromUri(dynamicInterfaceUri).readAsStringSync(),
         options.dynamicInterfaceUri!);
   } else if (isDynamicModule) {
-    moduleStrategy = DynamicModuleStrategy(component, options, target,
-        coreTypes, classHierarchy, dynamicModuleMainUri);
+    moduleStrategy = DynamicModuleStrategy(
+        component, options, target, coreTypes, dynamicModuleMainUri);
   } else {
     moduleStrategy = DefaultModuleStrategy(component);
   }
@@ -268,19 +268,25 @@ Future<CompilationResult> compileToModule(
     final source = DataDeserializer(dynamicModuleMetadataBytes, component);
     mainModuleMetadata = MainModuleMetadata.deserialize(source);
     mainModuleMetadata.verifyDynamicModuleOptions(options);
+    mainModuleMetadata.initializeDynamicModuleKernel(
+        component,
+        coreTypes,
+        // Create a new hierarchy with generated record classes.
+        ClassHierarchy(component, coreTypes) as ClosedWorldClassHierarchy);
   } else if (isDynamicMainModule) {
     MainModuleMetadata.verifyMainModuleOptions(options);
     writeComponentToBinary(component, dynamicModuleMainUri.path,
         includeSource: false);
   }
 
-  _patchMainTearOffs(coreTypes, component);
+  if (!isDynamicModule) {
+    _patchMainTearOffs(coreTypes, component);
 
-  // Keep the flags in-sync with
-  // pkg/vm/test/transformations/type_flow/transformer_test.dart
-  // TODO(natebiggs): Only run TFA on main module when dynamic modules enabled.
-  globalTypeFlow.transformComponent(target, coreTypes, component,
-      useRapidTypeAnalysis: false);
+    // Keep the flags in-sync with
+    // pkg/vm/test/transformations/type_flow/transformer_test.dart
+    globalTypeFlow.transformComponent(target, coreTypes, component,
+        useRapidTypeAnalysis: false);
+  }
 
   if (options.dumpKernelAfterTfa != null) {
     writeComponentToText(component,
@@ -295,10 +301,6 @@ Future<CompilationResult> compileToModule(
 
   final moduleOutputData = moduleStrategy.buildModuleOutputData();
 
-  if (isDynamicMainModule) {
-    mainModuleMetadata.initialize(component, coreTypes);
-  }
-
   var translator = Translator(component, coreTypes, libraryIndex, recordClasses,
       moduleOutputData, options.translatorOptions,
       mainModuleMetadata: mainModuleMetadata,
@@ -340,7 +342,7 @@ Future<CompilationResult> compileToModule(
         Uri.parse(
             path.setExtension(dynamicMainModuleUri!.toFilePath(), '.dyndata'));
     final serializer = DataSerializer(translator.component);
-    translator.dynamicModuleInfo!.metadata.serialize(translator, serializer);
+    translator.dynamicModuleInfo!.metadata.serialize(serializer, translator);
     await File.fromUri(filename).writeAsBytes(serializer.takeBytes());
   }
 

pkg/dart2wasm/lib/constants.dart

@@ -595,6 +595,8 @@ class ConstantCreator extends ConstantVisitor<ConstantInfo?>
 
     if (cls == Constants._relativeInterfaceTypeIndicator) {
       cls = translator.interfaceTypeClass;
+      constant = InstanceConstant(
+          cls.reference, constant.typeArguments, constant.fieldValues);
       isRelativeInterfaceType = true;
     }