Add SSA instructions for reified type information

pkg/compiler/lib/src/ssa/codegen.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 import '../common.dart';
 import '../common/codegen.dart' show CodegenRegistry, CodegenWorkItem;
 import '../common/tasks.dart' show CompilerTask;
 import '../compiler.dart' show Compiler;
 import '../constants/constant_system.dart';
 import '../constants/values.dart';
@@ skipping 2837 matching lines @@
     } else {
       var arguments = [
         returnType,
         new js.ArrayInitializer(parameterTypes),
         new js.ObjectInitializer(namedParameters)
       ];
       push(js.js('#(#)', [accessHelper('buildNamedFunctionType'), arguments]));
     }
   }
 
+  void visitTypeInfoReadRaw(HTypeInfoReadRaw node) {
+    use(node.inputs[0]);
+    js.Expression receiver = pop();
+    push(js.js(r'#.$builtinTypeInfo', receiver));

[Siggi Cherem (dart-lang), 2016/08/19 18:21:46]

I thought $builtinTypeInfo was replaced by $ti, is it still around in some
cases? or is it just that the other CL is not submitted yet, but after that this
will become $ti?

[sra1, 2016/08/19 18:47:43]

Yes, the renaming is part of the other CL

+  }
+
+  void visitTypeInfoReadVariable(HTypeInfoReadVariable node) {
+    TypeVariableElement element = node.variable.element;
+    ClassElement context = element.enclosingClass;
+
+    int index = element.index;
+    use(node.inputs[0]);
+    js.Expression receiver = pop();
+
+    if (needsSubstitutionForTypeVariableAccess(context)) {
+      js.Expression typeName =
+          js.quoteName(backend.namer.runtimeTypeName(context));
+      Element helperElement = helpers.getRuntimeTypeArgument;
+      registry.registerStaticUse(
+          new StaticUse.staticInvoke(helperElement, CallStructure.THREE_ARGS));

[Siggi Cherem (dart-lang), 2016/08/19 18:21:46]

I'm surprised we never registered this before (even though it was called from
the builder), was that a bug?

[sra1, 2016/08/19 18:47:43]

No bug. It was registered via being lowered to a HInvokeStatic.

+      js.Expression helper =
+          backend.emitter.staticFunctionAccess(helperElement);
+      push(js.js(
+          r'#(#, #, #)', [helper, receiver, typeName, js.js.number(index)]));
+    } else {
+      Element helperElement = helpers.getTypeArgumentByIndex;
+      registry.registerStaticUse(
+          new StaticUse.staticInvoke(helperElement, CallStructure.TWO_ARGS));
+      js.Expression helper =
+          backend.emitter.staticFunctionAccess(helperElement);
+      push(js.js(r'#(#, #)', [helper, receiver, js.js.number(index)]));
+    }
+  }
+
+  void visitTypeInfoExpression(HTypeInfoExpression node) {
+    List<js.Expression> arguments = <js.Expression>[];
+    for (HInstruction input in node.inputs) {
+      use(input);
+      arguments.add(pop());
+    }
+
+    switch (node.kind) {
+      case TypeInfoExpressionKind.COMPLETE:
+        int index = 0;
+        js.Expression result = backend.rtiEncoder.getTypeRepresentation(
+            node.dartType,
+            (TypeVariableType variable) => arguments[index++]);
+        if (index != node.inputs.length) {
+          print('$node   $index  ${node.inputs}');

[Siggi Cherem (dart-lang), 2016/08/19 18:21:46]

delete debug code?

[sra1, 2016/08/19 18:47:43]

Done. That was from debugging https://codereview.chromium.org/2257813003/

+        }
+        assert(index == node.inputs.length);
+        push(result);
+        return;
+
+      case TypeInfoExpressionKind.INSTANCE:
+        // We expect only flat types for the INSTANCE representation.
+        assert(
+            node.dartType == (node.dartType.element as ClassElement).thisType);
+        registry.registerInstantiatedClass(coreClasses.listClass);
+        push(new js.ArrayInitializer(arguments)
+             .withSourceInformation(node.sourceInformation));
+    }
+  }
+
+  bool needsSubstitutionForTypeVariableAccess(ClassElement cls) {
+    ClassWorld classWorld = compiler.world;
+    if (classWorld.isUsedAsMixin(cls)) return true;
+
+    return compiler.world.anyStrictSubclassOf(cls, (ClassElement subclass) {
+      return !backend.rti.isTrivialSubstitution(subclass, cls);
+    });
+  }
+
   void visitReadTypeVariable(HReadTypeVariable node) {
     TypeVariableElement element = node.dartType.element;
     Element helperElement = helpers.convertRtiToRuntimeType;
     registry.registerStaticUse(
         new StaticUse.staticInvoke(helperElement, CallStructure.ONE_ARG));
 
     use(node.inputs[0]);
     if (node.hasReceiver) {
       if (backend.isInterceptorClass(element.enclosingClass)) {
         int index = element.index;
@@ skipping 46 matching lines @@
     registry.registerStaticUse(new StaticUse.staticInvoke(
         helper, new CallStructure.unnamed(argumentCount)));
     return backend.emitter.staticFunctionAccess(helper);
   }
 
   @override
   void visitRef(HRef node) {
     visit(node.value);
   }
 }