Introduce ClassLike, MemberLike, FieldLike and FunctionLike

pkg/compiler/lib/src/ssa/optimize.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/codegen.dart' show CodegenRegistry, CodegenWorkItem;
 import '../common/names.dart' show Selectors;
 import '../common/tasks.dart' show CompilerTask;
 import '../compiler.dart' show Compiler;
 import '../constants/constant_system.dart';
 import '../constants/values.dart';
@@ skipping 314 matching lines @@
     if (actualReceiver.isIndexablePrimitive(compiler)) {
       if (actualReceiver.isConstantString()) {
         HConstant constantInput = actualReceiver;
         StringConstantValue constant = constantInput.constant;
         return graph.addConstantInt(constant.length, compiler);
       } else if (actualReceiver.isConstantList()) {
         HConstant constantInput = actualReceiver;
         ListConstantValue constant = constantInput.constant;
         return graph.addConstantInt(constant.length, compiler);
       }
-      Element element = helpers.jsIndexableLength;
+      MemberElement element = helpers.jsIndexableLength;
       bool isFixed = isFixedLength(actualReceiver.instructionType, compiler);
       TypeMask actualType = node.instructionType;
       ClosedWorld closedWorld = compiler.closedWorld;
       TypeMask resultType = backend.positiveIntType;
       // If we already have computed a more specific type, keep that type.
       if (HInstruction.isInstanceOf(
           actualType, helpers.jsUInt31Class, closedWorld)) {
         resultType = backend.uint31Type;
       } else if (HInstruction.isInstanceOf(
           actualType, helpers.jsUInt32Class, closedWorld)) {
@@ skipping 30 matching lines @@
     HInstruction input = node.inputs[1];
 
     ClosedWorld world = compiler.closedWorld;
 
     bool applies(Element element) {
       return selector.applies(element) &&
           (mask == null || mask.canHit(element, selector, world));
     }
 
     if (selector.isCall || selector.isOperator) {
-      Element target;
+      MethodElement target;
       if (input.isExtendableArray(compiler)) {
         if (applies(helpers.jsArrayRemoveLast)) {
           target = helpers.jsArrayRemoveLast;
         } else if (applies(helpers.jsArrayAdd)) {
           // The codegen special cases array calls, but does not
           // inline argument type checks.
           if (!compiler.options.enableTypeAssertions) {
             target = helpers.jsArrayAdd;
           }
         }
@@ skipping 49 matching lines @@
     TypeMask receiverType = node.getDartReceiver(compiler).instructionType;
     Element element =
         compiler.closedWorld.locateSingleElement(node.selector, receiverType);
     // TODO(ngeoffray): Also fold if it's a getter or variable.
     if (element != null &&
         element.isFunction
         // If we found out that the only target is an implicitly called
         // [:noSuchMethod:] we just ignore it.
         &&
         node.selector.applies(element)) {
-      FunctionElement method = element;
+      MethodElement method = element;
 
       if (backend.isNative(method)) {
         HInstruction folded = tryInlineNativeMethod(node, method);
         if (folded != null) return folded;
       } else {
         // TODO(ngeoffray): If the method has optional parameters,
         // we should pass the default values.
         FunctionSignature parameters = method.functionSignature;
         if (parameters.optionalParameterCount == 0 ||
             parameters.parameterCount == node.selector.argumentCount) {
-          node.element = element;
+          node.element = method;
         }
       }
       return node;
     }
 
     // Replace method calls through fields with a closure call on the value of
     // the field. This usually removes the demand for the call-through stub and
     // makes the field load available to further optimization, e.g. LICM.
 
     if (element != null &&
         element.isField &&
         element.name == node.selector.name) {
-      if (!backend.isNative(element) && !node.isCallOnInterceptor(compiler)) {
+      FieldElement field = element;
+      if (!backend.isNative(field) && !node.isCallOnInterceptor(compiler)) {
         HInstruction receiver = node.getDartReceiver(compiler);
-        TypeMask type =
-            TypeMaskFactory.inferredTypeForElement(element, compiler);
-        HInstruction load = new HFieldGet(element, receiver, type);
+        TypeMask type = TypeMaskFactory.inferredTypeForElement(field, compiler);
+        HInstruction load = new HFieldGet(field, receiver, type);
         node.block.addBefore(node, load);
         Selector callSelector = new Selector.callClosureFrom(node.selector);
         List<HInstruction> inputs = <HInstruction>[load]
           ..addAll(node.inputs.skip(node.isInterceptedCall ? 2 : 1));
         HInstruction closureCall =
             new HInvokeClosure(callSelector, inputs, node.instructionType)
               ..sourceInformation = node.sourceInformation;
         node.block.addAfter(load, closureCall);
         return closureCall;
       }
     }
 
     return node;
   }
 
   HInstruction tryInlineNativeMethod(
-      HInvokeDynamicMethod node, FunctionElement method) {
+      HInvokeDynamicMethod node, MethodElement method) {
     // Enable direct calls to a native method only if we don't run in checked
     // mode, where the Dart version may have type annotations on parameters and
     // return type that it should check.
     // Also check that the parameters are not functions: it's the callee that
     // will translate them to JS functions.
     //
     // TODO(ngeoffray): There are some cases where we could still inline in
     // checked mode if we know the arguments have the right type. And we could
     // do the closure conversion as well as the return type annotation check.
 
@@ skipping 306 matching lines @@
   HInstruction removeIfCheckAlwaysSucceeds(HCheck node, TypeMask checkedType) {
     ClosedWorld closedWorld = compiler.closedWorld;
     if (checkedType.containsAll(closedWorld)) return node;
     HInstruction input = node.checkedInput;
     TypeMask inputType = input.instructionType;
     return inputType.isInMask(checkedType, closedWorld) ? input : node;
   }
 
   HInstruction removeCheck(HCheck node) => node.checkedInput;
 
-  VariableElement findConcreteFieldForDynamicAccess(
+  FieldElement findConcreteFieldForDynamicAccess(
       HInstruction receiver, Selector selector) {
     TypeMask receiverType = receiver.instructionType;
     return compiler.closedWorld.locateSingleField(selector, receiverType);
   }
 
   HInstruction visitFieldGet(HFieldGet node) {
     if (node.isNullCheck) return node;
     var receiver = node.receiver;
     if (node.element == helpers.jsIndexableLength) {
       if (graph.allocatedFixedLists.contains(receiver)) {
@@ skipping 54 matching lines @@
     return node;
   }
 
   HInstruction visitInvokeDynamicGetter(HInvokeDynamicGetter node) {
     propagateConstantValueToUses(node);
     if (node.isInterceptedCall) {
       HInstruction folded = handleInterceptedCall(node);
       if (folded != node) return folded;
     }
     HInstruction receiver = node.getDartReceiver(compiler);
-    Element field = findConcreteFieldForDynamicAccess(receiver, node.selector);
+    FieldElement field =
+        findConcreteFieldForDynamicAccess(receiver, node.selector);
     if (field != null) return directFieldGet(receiver, field);
 
     if (node.element == null) {
-      Element element = compiler.closedWorld
+      MemberElement element = compiler.closedWorld
           .locateSingleElement(node.selector, receiver.instructionType);
       if (element != null && element.name == node.selector.name) {
         node.element = element;
         if (element.isFunction) {
           // A property extraction getter, aka a tear-off.
           node.sideEffects.clearAllDependencies();
           node.sideEffects.clearAllSideEffects();
           node.setUseGvn(); // We don't care about identity of tear-offs.
         }
       }
     }
     return node;
   }
 
-  HInstruction directFieldGet(HInstruction receiver, Element field) {
+  HInstruction directFieldGet(HInstruction receiver, FieldElement field) {
     bool isAssignable = !compiler.closedWorld.fieldNeverChanges(field);
 
     TypeMask type;
     if (backend.isNative(field.enclosingClass)) {
       type = TypeMaskFactory.fromNativeBehavior(
           backend.getNativeFieldLoadBehavior(field), compiler);
     } else {
       type = TypeMaskFactory.inferredTypeForElement(field, compiler);
     }
 
     return new HFieldGet(field, receiver, type, isAssignable: isAssignable);
   }
 
   HInstruction visitInvokeDynamicSetter(HInvokeDynamicSetter node) {
     if (node.isInterceptedCall) {
       HInstruction folded = handleInterceptedCall(node);
       if (folded != node) return folded;
     }
 
     HInstruction receiver = node.getDartReceiver(compiler);
-    VariableElement field =
+    FieldElement field =
         findConcreteFieldForDynamicAccess(receiver, node.selector);
     if (field == null || !field.isAssignable) return node;
     // Use [:node.inputs.last:] in case the call follows the
     // interceptor calling convention, but is not a call on an
     // interceptor.
     HInstruction value = node.inputs.last;
     if (compiler.options.enableTypeAssertions) {
       DartType type = field.type;
       if (!type.treatAsRaw || type.isTypeVariable) {
         // We cannot generate the correct type representation here, so don't
         // inline this access.
         return node;
       }
       HInstruction other =
           value.convertType(compiler, type, HTypeConversion.CHECKED_MODE_CHECK);
       if (other != value) {
         node.block.addBefore(node, other);
         value = other;
       }
     }
     return new HFieldSet(field, receiver, value);
   }
 
   HInstruction visitInvokeStatic(HInvokeStatic node) {
     propagateConstantValueToUses(node);
-    Element element = node.element;
+    MemberElement element = node.element;
 
     if (element == backend.helpers.checkConcurrentModificationError) {
       if (node.inputs.length == 2) {
         HInstruction firstArgument = node.inputs[0];
         if (firstArgument is HConstant) {
           HConstant constant = firstArgument;
           if (constant.constant.isTrue) return constant;
         }
       }
     } else if (element == backend.helpers.checkInt) {
@@ skipping 351 matching lines @@
     index = insertBoundsCheck(node, node.receiver, index);
   }
 
   void visitIndexAssign(HIndexAssign node) {
     if (boundsChecked.contains(node)) return;
     HInstruction index = node.index;
     index = insertBoundsCheck(node, node.receiver, index);
   }
 
   void visitInvokeDynamicMethod(HInvokeDynamicMethod node) {
-    Element element = node.element;
+    MemberElement element = node.element;
     if (node.isInterceptedCall) return;
     if (element != helpers.jsArrayRemoveLast) return;
     if (boundsChecked.contains(node)) return;
     // `0` is the index we want to check, but we want to report `-1`, as if we
     // executed `a[a.length-1]`
     HBoundsCheck check = insertBoundsCheck(
         node, node.receiver, graph.addConstantInt(0, backend.compiler));
     HInstruction minusOne = graph.addConstantInt(-1, backend.compiler);
     check.inputs.add(minusOne);
     minusOne.usedBy.add(check);
@@ skipping 803 matching lines @@
 
     for (HBasicBlock block in falseTargets) {
       insertTypePropagationForDominatedUsers(block, input, nonNullType);
     }
     // We don't strengthen the known-true references. It doesn't happen often
     // and we don't want "if (x==null) return x;" to convert between JavaScript
     // 'null' and 'undefined'.
   }
 
   collectTargets(HInstruction instruction, List<HBasicBlock> trueTargets,
-                 List<HBasicBlock> falseTargets) {
+      List<HBasicBlock> falseTargets) {
     for (HInstruction user in instruction.usedBy) {
       if (user is HIf) {
         trueTargets?.add(user.thenBlock);
         falseTargets?.add(user.elseBlock);
       } else if (user is HNot) {
         collectTargets(user, falseTargets, trueTargets);
       } else if (user is HPhi) {
         List<HInstruction> inputs = user.inputs;
         if (inputs.length == 2) {
           assert(inputs.contains(instruction));
@@ skipping 76 matching lines @@
     HInstruction instruction = block.first;
     while (instruction != null) {
       HInstruction next = instruction.next;
       instruction.accept(this);
       instruction = next;
     }
   }
 
   void visitFieldGet(HFieldGet instruction) {
     if (instruction.isNullCheck) return;
-    Element element = instruction.element;
+    MemberElement element = instruction.element;
     HInstruction receiver = instruction.getDartReceiver(compiler).nonCheck();
     HInstruction existing = memorySet.lookupFieldValue(element, receiver);
     if (existing != null) {
       instruction.block.rewriteWithBetterUser(instruction, existing);
       instruction.block.remove(instruction);
     } else {
       memorySet.registerFieldValue(element, receiver, instruction);
     }
   }
 
   void visitFieldSet(HFieldSet instruction) {
     HInstruction receiver = instruction.getDartReceiver(compiler).nonCheck();
     memorySet.registerFieldValueUpdate(
         instruction.element, receiver, instruction.inputs.last);
   }
 
   void visitCreate(HCreate instruction) {
     memorySet.registerAllocation(instruction);
     if (shouldTrackInitialValues(instruction)) {
       int argumentIndex = 0;
-      instruction.element.forEachInstanceField((_, Element member) {
+      instruction.element.forEachInstanceField((_, FieldElement member) {
         if (compiler.elementHasCompileTimeError(member)) return;
         memorySet.registerFieldValue(
             member, instruction, instruction.inputs[argumentIndex++]);
       }, includeSuperAndInjectedMembers: true);
     }
     // In case this instruction has as input non-escaping objects, we
     // need to mark these objects as escaping.
     memorySet.killAffectedBy(instruction);
   }
 
@@ skipping 36 matching lines @@
   }
 
   void visitInstruction(HInstruction instruction) {
     if (instruction.isAllocation) {
       memorySet.registerAllocation(instruction);
     }
     memorySet.killAffectedBy(instruction);
   }
 
   void visitLazyStatic(HLazyStatic instruction) {
-    handleStaticLoad(instruction.element, instruction);
+    FieldElement field = instruction.element;
+    handleStaticLoad(field, instruction);
   }
 
-  void handleStaticLoad(Element element, HInstruction instruction) {
+  void handleStaticLoad(MemberElement element, HInstruction instruction) {
     HInstruction existing = memorySet.lookupFieldValue(element, null);
     if (existing != null) {
       instruction.block.rewriteWithBetterUser(instruction, existing);
       instruction.block.remove(instruction);
     } else {
       memorySet.registerFieldValue(element, null, instruction);
     }
   }
 
   void visitStatic(HStatic instruction) {
@@ skipping 126 matching lines @@
   void registerAllocation(HInstruction instruction) {
     assert(instruction == instruction.nonCheck());
     nonEscapingReceivers.add(instruction);
   }
 
   /**
    * Sets `receiver.element` to contain [value]. Kills all potential places that
    * may be affected by this update.
    */
   void registerFieldValueUpdate(
-      Element element, HInstruction receiver, HInstruction value) {
+      MemberElement element, HInstruction receiver, HInstruction value) {
     assert(receiver == null || receiver == receiver.nonCheck());
     if (backend.isNative(element)) {
       return; // TODO(14955): Remove this restriction?
     }
     // [value] is being set in some place in memory, we remove it from
     // the non-escaping set.
     nonEscapingReceivers.remove(value.nonCheck());
     Map<HInstruction, HInstruction> map =
         fieldValues.putIfAbsent(element, () => <HInstruction, HInstruction>{});
     map.forEach((key, value) {
       if (mayAlias(receiver, key)) map[key] = null;
     });
     map[receiver] = value;
   }
 
   /**
    * Registers that `receiver.element` is now [value].
    */
   void registerFieldValue(
-      Element element, HInstruction receiver, HInstruction value) {
+      MemberElement element, HInstruction receiver, HInstruction value) {
     assert(receiver == null || receiver == receiver.nonCheck());
     if (backend.isNative(element)) {
       return; // TODO(14955): Remove this restriction?
     }
     Map<HInstruction, HInstruction> map =
         fieldValues.putIfAbsent(element, () => <HInstruction, HInstruction>{});
     map[receiver] = value;
   }
 
   /**
@@ skipping 197 matching lines @@
 
     keyedValues.forEach((receiver, values) {
       result.keyedValues[receiver] =
           new Map<HInstruction, HInstruction>.from(values);
     });
 
     result.nonEscapingReceivers.addAll(nonEscapingReceivers);
     return result;
   }
 }