2.1/dev/core/src/com/google/gwt/dev/jjs/impl/JavaScriptObjectNormalizer.java - gwt - Git at Google

 /*
  * Copyright 2008 Google Inc.
  *
  * Licensed under the Apache License, Version 2.0 (the "License"); you may not
  * use this file except in compliance with the License. You may obtain a copy of
  * the License at
  *
  * http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
  * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
  * License for the specific language governing permissions and limitations under
  * the License.
  */
 package com.google.gwt.dev.jjs.impl;

 import com.google.gwt.dev.jjs.SourceInfo;
 import com.google.gwt.dev.jjs.ast.Context;
 import com.google.gwt.dev.jjs.ast.JArrayType;
 import com.google.gwt.dev.jjs.ast.JCastOperation;
 import com.google.gwt.dev.jjs.ast.JClassLiteral;
 import com.google.gwt.dev.jjs.ast.JClassType;
 import com.google.gwt.dev.jjs.ast.JConditional;
 import com.google.gwt.dev.jjs.ast.JDeclaredType;
 import com.google.gwt.dev.jjs.ast.JExpression;
 import com.google.gwt.dev.jjs.ast.JField;
 import com.google.gwt.dev.jjs.ast.JInstanceOf;
 import com.google.gwt.dev.jjs.ast.JLocal;
 import com.google.gwt.dev.jjs.ast.JLocalRef;
 import com.google.gwt.dev.jjs.ast.JMethod;
 import com.google.gwt.dev.jjs.ast.JMethodBody;
 import com.google.gwt.dev.jjs.ast.JMethodCall;
 import com.google.gwt.dev.jjs.ast.JModVisitor;
 import com.google.gwt.dev.jjs.ast.JNewArray;
 import com.google.gwt.dev.jjs.ast.JNonNullType;
 import com.google.gwt.dev.jjs.ast.JParameter;
 import com.google.gwt.dev.jjs.ast.JProgram;
 import com.google.gwt.dev.jjs.ast.JReferenceType;
 import com.google.gwt.dev.jjs.ast.JType;
 import com.google.gwt.dev.jjs.ast.js.JMultiExpression;
 import com.google.gwt.dev.util.log.speedtracer.CompilerEventType;
 import com.google.gwt.dev.util.log.speedtracer.SpeedTracerLogger;
 import com.google.gwt.dev.util.log.speedtracer.SpeedTracerLogger.Event;

 import java.util.Stack;

 /**
  * Replace references to JSO subtypes with JSO itself.
  */
 public class JavaScriptObjectNormalizer {
   /**
    * Map types from JSO subtypes to JSO itself.
    */
   private class NormalizeVisitor extends JModVisitor {

     private final Stack<JMethodBody> currentMethodBody = new Stack<JMethodBody>();

     @Override
     public void endVisit(JCastOperation x, Context ctx) {
       JType newType = translate(x.getCastType());
       if (newType != x.getCastType()) {
         ctx.replaceMe(new JCastOperation(x.getSourceInfo(), newType,
             x.getExpr()));
       }
     }

     @Override
     public void endVisit(JClassLiteral x, Context ctx) {
       JType newType = translate(x.getRefType());
       if (newType != x.getRefType()) {
         ctx.replaceMe(program.getLiteralClass(newType));
       }
     }

     @Override
     public void endVisit(JField x, Context ctx) {
       x.setType(translate(x.getType()));
     }

     @Override
     public void endVisit(JInstanceOf x, Context ctx) {
       JReferenceType newType = (JReferenceType) translate(x.getTestType());
       if (newType != x.getTestType()) {
         ctx.replaceMe(new JInstanceOf(x.getSourceInfo(), newType, x.getExpr()));
       }
     }

     @Override
     public void endVisit(JLocal x, Context ctx) {
       x.setType(translate(x.getType()));
     }

     @Override
     public void endVisit(JMethod x, Context ctx) {
       x.setType(translate(x.getType()));
     }

     @Override
     public void endVisit(JMethodBody x, Context ctx) {
       if (currentMethodBody.pop() != x) {
         throw new RuntimeException("Unexpected JMethodBody popped");
       }
     }

     /**
      * Polymorphic dispatches to interfaces implemented by both a JSO and a
      * regular type require special dispatch handling. If the instance is not a
      * Java-derived object, the method from the single JSO implementation will
      * be invoked. Otherwise, a polymorphic dispatch to the Java-derived object
      * is made.
      */
     @Override
     public void endVisit(JMethodCall x, Context ctx) {
       JDeclaredType targetClass = x.getTarget().getEnclosingType();
       if (program.typeOracle.getSingleJsoImpl(targetClass) != null) {

         SourceInfo info = x.getSourceInfo().makeChild(
             JavaScriptObjectNormalizer.class,
             "Polymorphic invocation of SingleJsoImpl interface");

         // Find the method in the JSO type
         JMethod jsoMethod = findJsoMethod(x.getTarget());
         assert jsoMethod != null;

         if (program.typeOracle.isDualJsoInterface(targetClass)) {
           /*
            * This is the special-case code to handle interfaces.
            */
           JMultiExpression multi = new JMultiExpression(info);
           JExpression instance = maybeMakeTempAssignment(multi, x.getInstance());

           // instance.method(arg, arg)
           JMethodCall localCall = new JMethodCall(info, instance, x.getTarget());
           localCall.addArgs(x.getArgs());

           // We need a second copy of the arguments for the else expression
           CloneExpressionVisitor cloner = new CloneExpressionVisitor();

           // instance.jsoMethod(arg, arg)
           JMethodCall jsoCall = new JMethodCall(info,
               cloner.cloneExpression(instance), jsoMethod);
           jsoCall.addArgs(cloner.cloneExpressions(x.getArgs()));

           // Cast.isJavaScriptObject() ? instance.jsoMethod() :
           // instance.method();
           JConditional newExpr = makeIsJsoConditional(info,
               cloner.cloneExpression(instance), x.getType(), jsoCall, localCall);

           multi.exprs.add(newExpr);
           // We may only have the ternary operation if there's no side-effect
           ctx.replaceMe(multi.exprs.size() == 1 ? multi.exprs.get(0) : multi);
         } else {
           /*
            * ... otherwise, if there's only a JSO implementation, we'll just
            * call that directly.
            */
           JMethodCall jsoCall = new JMethodCall(info, x.getInstance(),
               jsoMethod);
           jsoCall.addArgs(x.getArgs());
           ctx.replaceMe(jsoCall);
         }
       }
     }

     @Override
     public void endVisit(JNewArray x, Context ctx) {
       x.setType((JNonNullType) translate(x.getType()));
     }

     @Override
     public void endVisit(JParameter x, Context ctx) {
       x.setType(translate(x.getType()));
     }

     @Override
     public boolean visit(JMethodBody x, Context ctx) {
       currentMethodBody.push(x);
       return true;
     }

     private JMethod findConcreteImplementation(JMethod method,
         JClassType concreteType) {
       /*
        * Search supertypes for virtual overrides via subclass. See the javadoc
        * on JTypeOracle.getAllVirtualOverrides for an example.
        */
       while (concreteType != null) {
         for (JMethod m : concreteType.getMethods()) {
           if (program.typeOracle.getAllOverrides(m).contains(method)) {
             if (!m.isAbstract()) {
               return m;
             }
           }
         }
         concreteType = concreteType.getSuperClass();
       }

       return null;
     }

     private JMethod findJsoMethod(JMethod interfaceMethod) {
       JClassType jsoClass = program.typeOracle.getSingleJsoImpl(interfaceMethod.getEnclosingType());
       assert program.isJavaScriptObject(jsoClass);
       assert jsoClass != null;

       JMethod toReturn = findConcreteImplementation(interfaceMethod, jsoClass);
       assert toReturn != null;
       assert !toReturn.isAbstract();
       assert jsoClass.isFinal() || toReturn.isFinal();

       return toReturn;
     }

     private JConditional makeIsJsoConditional(SourceInfo info,
         JExpression instance, JType conditionalType, JExpression isJsoExpr,
         JExpression notJsoExpr) {
       // Cast.isJavaScriptObjectOrString(instance)
       JMethod isJavaScriptObjectMethod = program.getIndexedMethod("Cast.isJavaScriptObjectOrString");
       JMethodCall isJavaScriptObjectExpr = new JMethodCall(info, null,
           isJavaScriptObjectMethod);
       isJavaScriptObjectExpr.addArg(instance);
       return new JConditional(info, conditionalType, isJavaScriptObjectExpr,
           isJsoExpr, notJsoExpr);
     }

     private JExpression maybeMakeTempAssignment(JMultiExpression multi,
         JExpression instance) {
       if (instance.hasSideEffects()) {
         /*
          * It may be necessary to save off the instance expression into a local
          * variable if its evaluation would produce side-effects. The
          * multi-expression is used for this purpose.
          */
         SourceInfo info = instance.getSourceInfo().makeChild(
             JavaScriptObjectNormalizer.class,
             "Temporary assignment for instance with side-effects");
         JLocal local = JProgram.createLocal(info, "maybeJsoInvocation",
             instance.getType(), true, currentMethodBody.peek());
         multi.exprs.add(JProgram.createAssignmentStmt(info,
             new JLocalRef(info, local), instance).getExpr());

         instance = new JLocalRef(info, local);
       }
       return instance;
     }

     private JType translate(JType type) {
       if (!(type instanceof JReferenceType)) {
         return type;
       }
       JReferenceType refType = (JReferenceType) type;
       boolean canBeNull = refType.canBeNull();
       refType = refType.getUnderlyingType();

       if (program.isJavaScriptObject(refType)) {
         refType = program.getJavaScriptObject();
       } else if (program.typeOracle.getSingleJsoImpl(refType) != null
           && !program.typeOracle.isDualJsoInterface(refType)) {
         // Optimization: narrow to JSO if it's not a dual impl.
         refType = program.getJavaScriptObject();
       } else if (refType instanceof JArrayType) {
         JArrayType arrayType = (JArrayType) refType;
         JType leafType = arrayType.getLeafType();
         JType replacement = translate(leafType);
         if (leafType != replacement) {
           refType = program.getTypeArray(replacement, arrayType.getDims());
         }
       }
       return canBeNull ? refType : program.getNonNullType(refType);
     }
   }

   public static void exec(JProgram program) {
     Event normalizerEvent = SpeedTracerLogger.start(CompilerEventType.NORMALIZER);
     new JavaScriptObjectNormalizer(program).execImpl();
     normalizerEvent.end();
   }

   private final JProgram program;

   private JavaScriptObjectNormalizer(JProgram program) {
     this.program = program;
   }

   private void execImpl() {
     NormalizeVisitor visitor = new NormalizeVisitor();
     visitor.accept(program);
   }
 }
	/*
	* Copyright 2008 Google Inc.
	*
	* Licensed under the Apache License, Version 2.0 (the "License"); you may not
	* use this file except in compliance with the License. You may obtain a copy of
	* the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
	* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
	* License for the specific language governing permissions and limitations under
	* the License.
	*/
	package com.google.gwt.dev.jjs.impl;

	import com.google.gwt.dev.jjs.SourceInfo;
	import com.google.gwt.dev.jjs.ast.Context;
	import com.google.gwt.dev.jjs.ast.JArrayType;
	import com.google.gwt.dev.jjs.ast.JCastOperation;
	import com.google.gwt.dev.jjs.ast.JClassLiteral;
	import com.google.gwt.dev.jjs.ast.JClassType;
	import com.google.gwt.dev.jjs.ast.JConditional;
	import com.google.gwt.dev.jjs.ast.JDeclaredType;
	import com.google.gwt.dev.jjs.ast.JExpression;
	import com.google.gwt.dev.jjs.ast.JField;
	import com.google.gwt.dev.jjs.ast.JInstanceOf;
	import com.google.gwt.dev.jjs.ast.JLocal;
	import com.google.gwt.dev.jjs.ast.JLocalRef;
	import com.google.gwt.dev.jjs.ast.JMethod;
	import com.google.gwt.dev.jjs.ast.JMethodBody;
	import com.google.gwt.dev.jjs.ast.JMethodCall;
	import com.google.gwt.dev.jjs.ast.JModVisitor;
	import com.google.gwt.dev.jjs.ast.JNewArray;
	import com.google.gwt.dev.jjs.ast.JNonNullType;
	import com.google.gwt.dev.jjs.ast.JParameter;
	import com.google.gwt.dev.jjs.ast.JProgram;
	import com.google.gwt.dev.jjs.ast.JReferenceType;
	import com.google.gwt.dev.jjs.ast.JType;
	import com.google.gwt.dev.jjs.ast.js.JMultiExpression;
	import com.google.gwt.dev.util.log.speedtracer.CompilerEventType;
	import com.google.gwt.dev.util.log.speedtracer.SpeedTracerLogger;
	import com.google.gwt.dev.util.log.speedtracer.SpeedTracerLogger.Event;

	import java.util.Stack;

	/**
	* Replace references to JSO subtypes with JSO itself.
	*/
	public class JavaScriptObjectNormalizer {
	/**
	* Map types from JSO subtypes to JSO itself.
	*/
	private class NormalizeVisitor extends JModVisitor {

	private final Stack<JMethodBody> currentMethodBody = new Stack<JMethodBody>();

	@Override
	public void endVisit(JCastOperation x, Context ctx) {
	JType newType = translate(x.getCastType());
	if (newType != x.getCastType()) {
	ctx.replaceMe(new JCastOperation(x.getSourceInfo(), newType,
	x.getExpr()));
	}
	}

	@Override
	public void endVisit(JClassLiteral x, Context ctx) {
	JType newType = translate(x.getRefType());
	if (newType != x.getRefType()) {
	ctx.replaceMe(program.getLiteralClass(newType));
	}
	}

	@Override
	public void endVisit(JField x, Context ctx) {
	x.setType(translate(x.getType()));
	}

	@Override
	public void endVisit(JInstanceOf x, Context ctx) {
	JReferenceType newType = (JReferenceType) translate(x.getTestType());
	if (newType != x.getTestType()) {
	ctx.replaceMe(new JInstanceOf(x.getSourceInfo(), newType, x.getExpr()));
	}
	}

	@Override
	public void endVisit(JLocal x, Context ctx) {
	x.setType(translate(x.getType()));
	}

	@Override
	public void endVisit(JMethod x, Context ctx) {
	x.setType(translate(x.getType()));
	}

	@Override
	public void endVisit(JMethodBody x, Context ctx) {
	if (currentMethodBody.pop() != x) {
	throw new RuntimeException("Unexpected JMethodBody popped");
	}
	}

	/**
	* Polymorphic dispatches to interfaces implemented by both a JSO and a
	* regular type require special dispatch handling. If the instance is not a
	* Java-derived object, the method from the single JSO implementation will
	* be invoked. Otherwise, a polymorphic dispatch to the Java-derived object
	* is made.
	*/
	@Override
	public void endVisit(JMethodCall x, Context ctx) {
	JDeclaredType targetClass = x.getTarget().getEnclosingType();
	if (program.typeOracle.getSingleJsoImpl(targetClass) != null) {

	SourceInfo info = x.getSourceInfo().makeChild(
	JavaScriptObjectNormalizer.class,
	"Polymorphic invocation of SingleJsoImpl interface");

	// Find the method in the JSO type
	JMethod jsoMethod = findJsoMethod(x.getTarget());
	assert jsoMethod != null;

	if (program.typeOracle.isDualJsoInterface(targetClass)) {
	/*
	* This is the special-case code to handle interfaces.
	*/
	JMultiExpression multi = new JMultiExpression(info);
	JExpression instance = maybeMakeTempAssignment(multi, x.getInstance());

	// instance.method(arg, arg)
	JMethodCall localCall = new JMethodCall(info, instance, x.getTarget());
	localCall.addArgs(x.getArgs());

	// We need a second copy of the arguments for the else expression
	CloneExpressionVisitor cloner = new CloneExpressionVisitor();

	// instance.jsoMethod(arg, arg)
	JMethodCall jsoCall = new JMethodCall(info,
	cloner.cloneExpression(instance), jsoMethod);
	jsoCall.addArgs(cloner.cloneExpressions(x.getArgs()));

	// Cast.isJavaScriptObject() ? instance.jsoMethod() :
	// instance.method();
	JConditional newExpr = makeIsJsoConditional(info,
	cloner.cloneExpression(instance), x.getType(), jsoCall, localCall);

	multi.exprs.add(newExpr);
	// We may only have the ternary operation if there's no side-effect
	ctx.replaceMe(multi.exprs.size() == 1 ? multi.exprs.get(0) : multi);
	} else {
	/*
	* ... otherwise, if there's only a JSO implementation, we'll just
	* call that directly.
	*/
	JMethodCall jsoCall = new JMethodCall(info, x.getInstance(),
	jsoMethod);
	jsoCall.addArgs(x.getArgs());
	ctx.replaceMe(jsoCall);
	}
	}
	}

	@Override
	public void endVisit(JNewArray x, Context ctx) {
	x.setType((JNonNullType) translate(x.getType()));
	}

	@Override
	public void endVisit(JParameter x, Context ctx) {
	x.setType(translate(x.getType()));
	}

	@Override
	public boolean visit(JMethodBody x, Context ctx) {
	currentMethodBody.push(x);
	return true;
	}

	private JMethod findConcreteImplementation(JMethod method,
	JClassType concreteType) {
	/*
	* Search supertypes for virtual overrides via subclass. See the javadoc
	* on JTypeOracle.getAllVirtualOverrides for an example.
	*/
	while (concreteType != null) {
	for (JMethod m : concreteType.getMethods()) {
	if (program.typeOracle.getAllOverrides(m).contains(method)) {
	if (!m.isAbstract()) {
	return m;
	}
	}
	}
	concreteType = concreteType.getSuperClass();
	}

	return null;
	}

	private JMethod findJsoMethod(JMethod interfaceMethod) {
	JClassType jsoClass = program.typeOracle.getSingleJsoImpl(interfaceMethod.getEnclosingType());
	assert program.isJavaScriptObject(jsoClass);
	assert jsoClass != null;

	JMethod toReturn = findConcreteImplementation(interfaceMethod, jsoClass);
	assert toReturn != null;
	assert !toReturn.isAbstract();
	assert jsoClass.isFinal() \|\| toReturn.isFinal();

	return toReturn;
	}

	private JConditional makeIsJsoConditional(SourceInfo info,
	JExpression instance, JType conditionalType, JExpression isJsoExpr,
	JExpression notJsoExpr) {
	// Cast.isJavaScriptObjectOrString(instance)
	JMethod isJavaScriptObjectMethod = program.getIndexedMethod("Cast.isJavaScriptObjectOrString");
	JMethodCall isJavaScriptObjectExpr = new JMethodCall(info, null,
	isJavaScriptObjectMethod);
	isJavaScriptObjectExpr.addArg(instance);
	return new JConditional(info, conditionalType, isJavaScriptObjectExpr,
	isJsoExpr, notJsoExpr);
	}

	private JExpression maybeMakeTempAssignment(JMultiExpression multi,
	JExpression instance) {
	if (instance.hasSideEffects()) {
	/*
	* It may be necessary to save off the instance expression into a local
	* variable if its evaluation would produce side-effects. The
	* multi-expression is used for this purpose.
	*/
	SourceInfo info = instance.getSourceInfo().makeChild(
	JavaScriptObjectNormalizer.class,
	"Temporary assignment for instance with side-effects");
	JLocal local = JProgram.createLocal(info, "maybeJsoInvocation",
	instance.getType(), true, currentMethodBody.peek());
	multi.exprs.add(JProgram.createAssignmentStmt(info,
	new JLocalRef(info, local), instance).getExpr());

	instance = new JLocalRef(info, local);
	}
	return instance;
	}

	private JType translate(JType type) {
	if (!(type instanceof JReferenceType)) {
	return type;
	}
	JReferenceType refType = (JReferenceType) type;
	boolean canBeNull = refType.canBeNull();
	refType = refType.getUnderlyingType();

	if (program.isJavaScriptObject(refType)) {
	refType = program.getJavaScriptObject();
	} else if (program.typeOracle.getSingleJsoImpl(refType) != null
	&& !program.typeOracle.isDualJsoInterface(refType)) {
	// Optimization: narrow to JSO if it's not a dual impl.
	refType = program.getJavaScriptObject();
	} else if (refType instanceof JArrayType) {
	JArrayType arrayType = (JArrayType) refType;
	JType leafType = arrayType.getLeafType();
	JType replacement = translate(leafType);
	if (leafType != replacement) {
	refType = program.getTypeArray(replacement, arrayType.getDims());
	}
	}
	return canBeNull ? refType : program.getNonNullType(refType);
	}
	}

	public static void exec(JProgram program) {
	Event normalizerEvent = SpeedTracerLogger.start(CompilerEventType.NORMALIZER);
	new JavaScriptObjectNormalizer(program).execImpl();
	normalizerEvent.end();
	}

	private final JProgram program;

	private JavaScriptObjectNormalizer(JProgram program) {
	this.program = program;
	}

	private void execImpl() {
	NormalizeVisitor visitor = new NormalizeVisitor();
	visitor.accept(program);
	}
	}