org.aspectj/org.aspectj.ajdt.core/src/org/aspectj/ajdt/internal/compiler/ast/AccessForInlineVisitor.java

/* *******************************************************************
 * Copyright (c) 2002 Palo Alto Research Center, Incorporated (PARC).
 * All rights reserved. 
 * This program and the accompanying materials are made available 
 * under the terms of the Common Public License v1.0 
 * which accompanies this distribution and is available at 
 * http://www.eclipse.org/legal/cpl-v10.html 
 *  
 * Contributors: 
 *     PARC     initial implementation 
 * ******************************************************************/


package org.aspectj.ajdt.internal.compiler.ast;

//import java.util.Arrays;

import org.aspectj.ajdt.internal.compiler.lookup.EclipseFactory;
import org.aspectj.ajdt.internal.compiler.lookup.InlineAccessFieldBinding;
import org.aspectj.ajdt.internal.compiler.lookup.InterTypeFieldBinding;
import org.aspectj.ajdt.internal.compiler.lookup.InterTypeMethodBinding;
import org.aspectj.ajdt.internal.compiler.lookup.PrivilegedFieldBinding;
import org.aspectj.ajdt.internal.compiler.lookup.PrivilegedHandler;
import org.aspectj.weaver.AjcMemberMaker;
import org.aspectj.weaver.ResolvedMember;
import org.aspectj.org.eclipse.jdt.internal.compiler.ASTVisitor;
//import org.aspectj.org.eclipse.jdt.internal.compiler.AbstractSyntaxTreeVisitorAdapter;
import org.aspectj.org.eclipse.jdt.internal.compiler.ast.AllocationExpression;
import org.aspectj.org.eclipse.jdt.internal.compiler.ast.AssertStatement;
import org.aspectj.org.eclipse.jdt.internal.compiler.ast.ClassLiteralAccess;
import org.aspectj.org.eclipse.jdt.internal.compiler.ast.FieldReference;
import org.aspectj.org.eclipse.jdt.internal.compiler.ast.MessageSend;
import org.aspectj.org.eclipse.jdt.internal.compiler.ast.QualifiedNameReference;
import org.aspectj.org.eclipse.jdt.internal.compiler.ast.QualifiedTypeReference;
import org.aspectj.org.eclipse.jdt.internal.compiler.ast.SingleNameReference;
import org.aspectj.org.eclipse.jdt.internal.compiler.ast.SingleTypeReference;
import org.aspectj.org.eclipse.jdt.internal.compiler.ast.ThisReference;
import org.aspectj.org.eclipse.jdt.internal.compiler.ast.TypeDeclaration;
import org.aspectj.org.eclipse.jdt.internal.compiler.lookup.ArrayBinding;
import org.aspectj.org.eclipse.jdt.internal.compiler.lookup.BlockScope;
import org.aspectj.org.eclipse.jdt.internal.compiler.lookup.FieldBinding;
import org.aspectj.org.eclipse.jdt.internal.compiler.lookup.MethodBinding;
import org.aspectj.org.eclipse.jdt.internal.compiler.lookup.ReferenceBinding;
import org.aspectj.org.eclipse.jdt.internal.compiler.lookup.TypeBinding;
import org.aspectj.org.eclipse.jdt.internal.compiler.lookup.VariableBinding;

/**
 * Walks the body of around advice
 * 
 * Makes sure that all member accesses are to public members.  Will
 * convert to use access methods when needed to ensure that.  This
 * makes it much simpler (and more modular) to inline the body of
 * an around.
 * 
 * ??? constructors are handled different and require access to the
 * target type.  changes to org.eclipse.jdt.internal.compiler.ast.AllocationExpression
 * would be required to fix this issue.
 * 
 * @author Jim Hugunin
 */

public class AccessForInlineVisitor extends ASTVisitor {
	PrivilegedHandler handler;
	AspectDeclaration inAspect;
	EclipseFactory world; // alias for inAspect.world
	
	//	set to true for ClassLiteralAccess and AssertStatement
	// ??? A better answer would be to transform these into inlinable forms
	public boolean isInlinable = true;  
	
	public AccessForInlineVisitor(AspectDeclaration inAspect, PrivilegedHandler handler) {
		this.inAspect = inAspect;
		this.world = inAspect.factory;
		this.handler = handler;
	}
	
	
	public void endVisit(SingleNameReference ref, BlockScope scope) {
		if (ref.binding instanceof FieldBinding) {
			ref.binding = getAccessibleField((FieldBinding)ref.binding, ref.actualReceiverType);
		}
	}

	public void endVisit(QualifiedNameReference ref, BlockScope scope) {
		if (ref.binding instanceof FieldBinding) {
			ref.binding = getAccessibleField((FieldBinding)ref.binding, ref.actualReceiverType);
		}
		if (ref.otherBindings != null && ref.otherBindings.length > 0) {
			TypeBinding receiverType;
			if (ref.binding instanceof FieldBinding) {
				receiverType = ((FieldBinding)ref.binding).type;
			} else if (ref.binding instanceof VariableBinding) {
				receiverType = ((VariableBinding)ref.binding).type;
			} else {
				//!!! understand and fix this case later
				receiverType = ref.otherBindings[0].declaringClass;
			}
			
			for (int i=0, len=ref.otherBindings.length; i < len; i++) {
				FieldBinding binding = ref.otherBindings[i];
				ref.otherBindings[i] = getAccessibleField(binding, receiverType);
				receiverType = binding.type;
			}
		}
	}

	public void endVisit(FieldReference ref, BlockScope scope) {
		ref.binding = getAccessibleField(ref.binding, ref.receiverType);
	}
	public void endVisit(MessageSend send, BlockScope scope) {
		if (send instanceof Proceed) return;
		if (send.binding == null || !send.binding.isValidBinding()) return;
		
		if (send.isSuperAccess() && !send.binding.isStatic()) {
			send.receiver = new ThisReference(send.sourceStart, send.sourceEnd);
			MethodBinding superAccessBinding = getSuperAccessMethod(send.binding);
			AstUtil.replaceMethodBinding(send, superAccessBinding);
		} else if (!isPublic(send.binding)) {
			send.syntheticAccessor = getAccessibleMethod(send.binding, send.actualReceiverType);
		}
	}
	public void endVisit(AllocationExpression send, BlockScope scope) {
		if (send.binding == null || !send.binding.isValidBinding()) return;
		//XXX TBD
		if (isPublic(send.binding)) return;
		makePublic(send.binding.declaringClass);
		send.binding = handler.getPrivilegedAccessMethod(send.binding, send);
	}	
	public void endVisit(
		QualifiedTypeReference ref,
		BlockScope scope)
	{
		makePublic(ref.resolvedType); //getTypeBinding(scope));   //??? might be trouble
	}
	
	public void endVisit(
		SingleTypeReference ref,
		BlockScope scope)
	{
		makePublic(ref.resolvedType); //getTypeBinding(scope));  //??? might be trouble
	}
	
	private FieldBinding getAccessibleField(FieldBinding binding, TypeBinding receiverType) {
		//System.err.println("checking field: " + binding);
		if (!binding.isValidBinding()) return binding;
		
		makePublic(receiverType);
		if (isPublic(binding)) return binding;
		if (binding instanceof PrivilegedFieldBinding) return binding;
		if (binding instanceof InterTypeFieldBinding) return binding;

		if (binding.isPrivate() &&  binding.declaringClass != inAspect.binding) {
			binding.modifiers = AstUtil.makePackageVisible(binding.modifiers);
		}
		
		ResolvedMember m = EclipseFactory.makeResolvedMember(binding, receiverType);
		if (inAspect.accessForInline.containsKey(m)) return (FieldBinding)inAspect.accessForInline.get(m);
		FieldBinding ret = new InlineAccessFieldBinding(inAspect, binding, m);
		
		//System.err.println("   made accessor: " + ret);
		
		inAspect.accessForInline.put(m, ret);
		return ret;
	}
	
	private MethodBinding getAccessibleMethod(MethodBinding binding, TypeBinding receiverType) {
		if (!binding.isValidBinding()) return binding;
		
		makePublic(receiverType);  //???
		if (isPublic(binding)) return binding;
		if (binding instanceof InterTypeMethodBinding) return binding;

		ResolvedMember m = null;
		if (binding.isPrivate() &&  binding.declaringClass != inAspect.binding) {
			// does this always mean that the aspect is an inner aspect of the bindings
			// declaring class?  After all, the field is private but we can see it from 
			// where we are.
			binding.modifiers = AstUtil.makePackageVisible(binding.modifiers);
			m = EclipseFactory.makeResolvedMember(binding);
		} else {
			// Sometimes receiverType and binding.declaringClass are *not* the same.
			
			// Sometimes receiverType is a subclass of binding.declaringClass.  In these situations
			// we want the generated inline accessor to call the method on the subclass (at
			// runtime this will be satisfied by the super).
			m = EclipseFactory.makeResolvedMember(binding, receiverType);
		}
		if (inAspect.accessForInline.containsKey(m)) return (MethodBinding)inAspect.accessForInline.get(m);
		MethodBinding ret = world.makeMethodBinding(
			AjcMemberMaker.inlineAccessMethodForMethod(inAspect.typeX, m));
		inAspect.accessForInline.put(m, ret);
		return ret;
	}
	
	static class SuperAccessMethodPair {
		public ResolvedMember originalMethod;
		public MethodBinding accessMethod;
		public SuperAccessMethodPair(ResolvedMember originalMethod, MethodBinding accessMethod) {
			this.originalMethod = originalMethod;
			this.accessMethod = accessMethod;
		}
	}
	
	private MethodBinding getSuperAccessMethod(MethodBinding binding) {
		ResolvedMember m = EclipseFactory.makeResolvedMember(binding);
		ResolvedMember superAccessMember = AjcMemberMaker.superAccessMethod(inAspect.typeX, m);
		if (inAspect.superAccessForInline.containsKey(superAccessMember)) {
			return ((SuperAccessMethodPair)inAspect.superAccessForInline.get(superAccessMember)).accessMethod;
		} 
		MethodBinding ret = world.makeMethodBinding(superAccessMember);
		inAspect.superAccessForInline.put(superAccessMember, new SuperAccessMethodPair(m, ret));
		return ret;
	}
	
	private boolean isPublic(FieldBinding fieldBinding) {
		// these are always effectively public to the inliner
		if (fieldBinding instanceof InterTypeFieldBinding) return true;
		return fieldBinding.isPublic();
	}

	private boolean isPublic(MethodBinding methodBinding) {
		// these are always effectively public to the inliner
		if (methodBinding instanceof InterTypeMethodBinding) return true;
		return methodBinding.isPublic();
	}

	private void makePublic(TypeBinding binding) {
		if (binding == null || !binding.isValidBinding()) return;  // has already produced an error
		if (binding instanceof ReferenceBinding) {
			ReferenceBinding rb = (ReferenceBinding)binding;
			if (!rb.isPublic()) handler.notePrivilegedTypeAccess(rb, null); //???
		} else if (binding instanceof ArrayBinding) {
			makePublic( ((ArrayBinding)binding).leafComponentType );
		} else {
			return;
		}
	}

	public void endVisit(AssertStatement assertStatement, BlockScope scope) {
		isInlinable = false;
	}

	public void endVisit(ClassLiteralAccess classLiteral, BlockScope scope) {
		isInlinable = false;
	}

	public boolean visit(
		TypeDeclaration localTypeDeclaration,
		BlockScope scope) {
		// we don't want to transform any local anonymous classes as they won't be inlined
		return false;
	}

}