Compute Compiler.proxyConstant on demand.

pkg/compiler/lib/src/js_backend/backend.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.
 
 part of js_backend;
 
 const VERBOSE_OPTIMIZER_HINTS = false;
 
 class JavaScriptItemCompilationContext extends ItemCompilationContext {
   final Set<HInstruction> boundsChecked = new Set<HInstruction>();
@@ skipping 2973 matching lines @@
   }
 
   void onTypeVariableExpression(Registry registry) {
     assert(registry.isForResolution);
     registerBackendStaticInvocation(backend.getSetRuntimeTypeInfo(), registry);
     registerBackendStaticInvocation(backend.getGetRuntimeTypeInfo(), registry);
     backend.registerGetRuntimeTypeArgument(registry);
     registerBackendInstantiation(backend.compiler.listClass, registry);
     registerBackendStaticInvocation(backend.getRuntimeTypeToString(), registry);
     registerBackendStaticInvocation(backend.getCreateRuntimeType(), registry);
+    needsInt(registry); // Needed for accessing the type variable literal.

[karlklose, 2015/09/11 12:21:15]

Maybe we should make these comments into string arguments to the needsXxx calls,
so we could store/dump the relation later.

[Johnni Winther, 2015/09/11 12:38:36]

Done.

   }
 
   // TODO(johnniwinther): Maybe split this into [onAssertType] and [onTestType].
   void onIsCheck(DartType type, Registry registry) {
     assert(registry.isForResolution);
     type = type.unalias(backend.compiler);
     registerBackendInstantiation(backend.compiler.boolClass, registry);
     bool inCheckedMode = backend.compiler.enableTypeAssertions;
     if (inCheckedMode) {
       registerBackendStaticInvocation(backend.getThrowRuntimeError(), registry);
@@ skipping 40 matching lines @@
     assert(registry.isForResolution);
     registerBackendStaticInvocation(backend.getThrowTypeError(), registry);
     registerBackendStaticInvocation(backend.getAssertIsSubtype(), registry);
   }
 
   void onAbstractClassInstantiation(Registry registry) {
     assert(registry.isForResolution);
     registerBackendStaticInvocation(
         backend.getThrowAbstractClassInstantiationError(), registry);
     // Also register the types of the arguments passed to this method.
-    registerBackendInstantiation(backend.compiler.stringClass, registry);
+    needsString(registry); // Needed to encode the message.
   }
 
   void onFallThroughError(Registry registry) {
     assert(registry.isForResolution);
     registerBackendStaticInvocation(backend.getFallThroughError(), registry);
   }
 
   void onAsCheck(DartType type, Registry registry) {
     assert(registry.isForResolution);
     registerBackendStaticInvocation(backend.getThrowRuntimeError(), registry);
   }
 
   void onThrowNoSuchMethod(Registry registry) {
     assert(registry.isForResolution);
     registerBackendStaticInvocation(backend.getThrowNoSuchMethod(), registry);
     // Also register the types of the arguments passed to this method.
-    registerBackendInstantiation(backend.compiler.listClass, registry);
-    registerBackendInstantiation(backend.compiler.stringClass, registry);
+    needsList(registry); // Needed to encode the arguments.
+    needsString(registry); // Needed to encode the name.
   }
 
   void onThrowRuntimeError(Registry registry) {
     assert(registry.isForResolution);
     registerBackendStaticInvocation(backend.getThrowRuntimeError(), registry);
     // Also register the types of the arguments passed to this method.
     registerBackendInstantiation(backend.compiler.stringClass, registry);
   }
 
   void onCompileTimeError(Registry registry, ErroneousElement error) {
     if (backend.compiler.generateCodeWithCompileTimeErrors) {
       // TODO(johnniwinther): This should have its own uncatchable error.
       onThrowRuntimeError(registry);
     }
   }
 
   void onSuperNoSuchMethod(Registry registry) {
     assert(registry.isForResolution);
     registerBackendStaticInvocation(
         backend.getCreateInvocationMirror(), registry);
     registerBackendStaticInvocation(
         backend.compiler.objectClass.lookupLocalMember(
             Identifiers.noSuchMethod_),
         registry);
-    registerBackendInstantiation(backend.compiler.listClass, registry);
-    registerBackendInstantiation(backend.compiler.stringClass, registry);
+    needsInt(registry); // Needed to encode the invocation kind.
+    needsList(registry); // Needed to encode the arguments.
+    needsString(registry); // Needed to encode the name.
   }
 
   void onMapLiteral(ResolutionRegistry registry,
                     DartType type,
                     bool isConstant) {
     assert(registry.isForResolution);
     void enqueue(String name) {
       Element e = backend.find(backend.jsHelperLibrary, name);
       registerBackendInstantiation(e, registry);
     }
 
     if (isConstant) {
       enqueue(JavaScriptMapConstant.DART_CLASS);
       enqueue(JavaScriptMapConstant.DART_PROTO_CLASS);
       enqueue(JavaScriptMapConstant.DART_STRING_CLASS);
       enqueue(JavaScriptMapConstant.DART_GENERAL_CLASS);
     } else {
       registry.registerInstantiatedType(type);
     }
   }
 
   /// Called when resolving the `Symbol` constructor.
   void onSymbolConstructor(Registry registry) {
     assert(registry.isForResolution);
     // Make sure that _internals.Symbol.validated is registered.
     assert(backend.compiler.symbolValidatedConstructor != null);
     registerBackendStaticInvocation(
         backend.compiler.symbolValidatedConstructor, registry);
   }
+
+  /// Called when resolving a prefix or postfix expression.
+  void onIncDecOperation(Registry registry) {
+    needsInt(registry); // Need for the `+ 1` or `- 1` operation.
+  }
+
+  /// Helper for registering that `int` is needed.
+  void needsInt(Registry registry) {
+    registerBackendInstantiation(backend.compiler.intClass, registry);
+  }
+
+  /// Helper for registering that `List` is needed.
+  void needsList(Registry registry) {
+    registerBackendInstantiation(backend.compiler.listClass, registry);
+  }
+
+  /// Helper for registering that `String` is needed.
+  void needsString(Registry registry) {
+    registerBackendInstantiation(backend.compiler.stringClass, registry);
+  }
 }
 
 /// Records that [constant] is used by the element behind [registry].
 class Dependency {
   final ConstantValue constant;
   final Element annotatedElement;
 
   const Dependency(this.constant, this.annotatedElement);
 }