org.aspectj.weaver.patterns.CflowPointcut Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of aspectjmatcher Show documentation
The AspectJ matcher can be used for matching pointcuts independently of any AspectJ compilation or weaving steps. Most notably, this can be used by frameworks such as Spring AOP which utilise the @AspectJ pointcut syntax but implement aspect weaving in a way independent of AspectJ, e.g. using dynamic proxies.
There is a newer version: 1.9.22.1
Show newest version
/* *******************************************************************
 * 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 Eclipse Public License v 2.0
 * which accompanies this distribution and is available at
 * https://www.eclipse.org/org/documents/epl-2.0/EPL-2.0.txt
 *
 * Contributors:
 *     PARC     initial implementation
 * ******************************************************************/

package org.aspectj.weaver.patterns;

import java.io.IOException;
import java.lang.reflect.Modifier;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
import java.util.Map;

import org.aspectj.bridge.IMessage;
import org.aspectj.util.FileUtil;
import org.aspectj.util.FuzzyBoolean;
import org.aspectj.weaver.Advice;
import org.aspectj.weaver.CompressingDataOutputStream;
import org.aspectj.weaver.CrosscuttingMembers;
import org.aspectj.weaver.ISourceContext;
import org.aspectj.weaver.IntMap;
import org.aspectj.weaver.Member;
import org.aspectj.weaver.NameMangler;
import org.aspectj.weaver.ResolvedMember;
import org.aspectj.weaver.ResolvedMemberImpl;
import org.aspectj.weaver.ResolvedPointcutDefinition;
import org.aspectj.weaver.ResolvedType;
import org.aspectj.weaver.Shadow;
import org.aspectj.weaver.ShadowMunger;
import org.aspectj.weaver.UnresolvedType;
import org.aspectj.weaver.VersionedDataInputStream;
import org.aspectj.weaver.WeaverMessages;
import org.aspectj.weaver.World;
import org.aspectj.weaver.ast.Test;
import org.aspectj.weaver.patterns.ConcreteCflowPointcut.Slot;

public class CflowPointcut extends Pointcut {
	private final Pointcut entry; // The pointcut inside the cflow() that
	// represents the 'entry' point
	boolean isBelow;// Is this cflowbelow?
	private int[] freeVars;

	/**
	 * Used to indicate that we're in the context of a cflow when concretizing if's
	 *
	 * Will be removed or replaced with something better when we handle this as a non-error
	 */
	public static final ResolvedPointcutDefinition CFLOW_MARKER = new ResolvedPointcutDefinition(null, 0, null,
			UnresolvedType.NONE, Pointcut.makeMatchesNothing(Pointcut.RESOLVED));

	public CflowPointcut(Pointcut entry, boolean isBelow, int[] freeVars) {
		// System.err.println("Building cflow pointcut "+entry.toString());
		this.entry = entry;
		this.isBelow = isBelow;
		this.freeVars = freeVars;
		pointcutKind = CFLOW;
	}

	public boolean isCflowBelow() {
		return isBelow;
	}

	public int couldMatchKinds() {
		return Shadow.ALL_SHADOW_KINDS_BITS;
	}

	// enh 76055
	public Pointcut getEntry() {
		return entry;
	}

	public FuzzyBoolean fastMatch(FastMatchInfo type) {
		return FuzzyBoolean.MAYBE;
	}

	protected FuzzyBoolean matchInternal(Shadow shadow) {
		// ??? this is not maximally efficient
		return FuzzyBoolean.MAYBE;
	}

	public void write(CompressingDataOutputStream s) throws IOException {
		s.writeByte(Pointcut.CFLOW);
		entry.write(s);
		s.writeBoolean(isBelow);
		FileUtil.writeIntArray(freeVars, s);
		writeLocation(s);
	}

	public static Pointcut read(VersionedDataInputStream s, ISourceContext context) throws IOException {

		CflowPointcut ret = new CflowPointcut(Pointcut.read(s, context), s.readBoolean(), FileUtil.readIntArray(s));
		ret.readLocation(context, s);
		return ret;
	}

	public Pointcut parameterizeWith(Map typeVariableMap, World w) {
		CflowPointcut ret = new CflowPointcut(entry.parameterizeWith(typeVariableMap, w), isBelow, freeVars);
		ret.copyLocationFrom(this);
		return ret;
	}

	public void resolveBindings(IScope scope, Bindings bindings) {
		if (bindings == null) {
			entry.resolveBindings(scope, null);
			entry.state = RESOLVED;
			freeVars = new int[0];
		} else {
			// ??? for if's sake we might need to be more careful here
			Bindings entryBindings = new Bindings(bindings.size());

			entry.resolveBindings(scope, entryBindings);
			entry.state = RESOLVED;

			freeVars = entryBindings.getUsedFormals();

			bindings.mergeIn(entryBindings, scope);
		}
	}

	public boolean equals(Object other) {
		if (!(other instanceof CflowPointcut)) {
			return false;
		}
		CflowPointcut o = (CflowPointcut) other;
		return o.entry.equals(entry) && o.isBelow == isBelow;
	}

	public int hashCode() {
		int result = 17;
		result = 37 * result + entry.hashCode();
		result = 37 * result + (isBelow ? 0 : 1);
		return result;
	}

	public String toString() {
		return "cflow" + (isBelow ? "below" : "") + "(" + entry + ")";
	}

	protected Test findResidueInternal(Shadow shadow, ExposedState state) {
		throw new RuntimeException("unimplemented - did concretization fail?");
	}

	public Pointcut concretize1(ResolvedType inAspect, ResolvedType declaringType, IntMap bindings) {

		// the pointcut is marked as CONCRETE after returning from this
		// call - so we can't skip concretization
		// if (this.entry.state == Pointcut.SYMBOLIC) {
		// // too early to concretize, return unchanged
		// return this;
		// }

		// Enforce rule about which designators are supported in declare
		if (isDeclare(bindings.getEnclosingAdvice())) {
			inAspect.getWorld().showMessage(IMessage.ERROR,
					WeaverMessages.format(WeaverMessages.CFLOW_IN_DECLARE, isBelow ? "below" : ""),
					bindings.getEnclosingAdvice().getSourceLocation(), null);
			return Pointcut.makeMatchesNothing(Pointcut.CONCRETE);
		}

		// make this remap from formal positions to arrayIndices
		IntMap entryBindings = new IntMap();
		if (freeVars != null) {
			for (int i = 0, len = freeVars.length; i < len; i++) {
				int freeVar = freeVars[i];
				// int formalIndex = bindings.get(freeVar);
				entryBindings.put(freeVar, i);
			}
		}
		entryBindings.copyContext(bindings);
		// System.out.println(this + " bindings: " + entryBindings);

		World world = inAspect.getWorld();

		Pointcut concreteEntry;

		ResolvedType concreteAspect = bindings.getConcreteAspect();

		CrosscuttingMembers xcut = concreteAspect.crosscuttingMembers;
		Collection previousCflowEntries = xcut.getCflowEntries();

		entryBindings.pushEnclosingDefinition(CFLOW_MARKER);
		// This block concretizes the pointcut within the cflow pointcut
		try {
			concreteEntry = entry.concretize(inAspect, declaringType, entryBindings);
		} finally {
			entryBindings.popEnclosingDefinitition();
		}

		List innerCflowEntries = new ArrayList<>(xcut.getCflowEntries());
		innerCflowEntries.removeAll(previousCflowEntries);

		// Four routes of interest through this code (did I hear someone say
		// refactor??)
		// 1) no state in the cflow - we can use a counter *and* we have seen
		// this pointcut
		// before - so use the same counter as before.
		// 2) no state in the cflow - we can use a counter, but this is the
		// first time
		// we have seen this pointcut, so build the infrastructure.
		// 3) state in the cflow - we need to use a stack *and* we have seen
		// this pointcut
		// before - so share the stack.
		// 4) state in the cflow - we need to use a stack, but this is the first
		// time
		// we have seen this pointcut, so build the infrastructure.

		if (freeVars == null || freeVars.length == 0) { // No state, so don't
			// use a stack, use a
			// counter.
			ResolvedMember localCflowField = null;

			Object field = getCflowfield(xcut, concreteEntry, concreteAspect, "counter");

			// Check if we have already got a counter for this cflow pointcut
			if (field != null) {
				localCflowField = (ResolvedMember) field; // Use the one we
				// already have

			} else {

				// Create a counter field in the aspect
				localCflowField = new ResolvedMemberImpl(Member.FIELD, concreteAspect, Modifier.STATIC | Modifier.PUBLIC,
						NameMangler.cflowCounter(xcut), UnresolvedType.forName(NameMangler.CFLOW_COUNTER_TYPE)
						.getSignature());

				// Create type munger to add field to the aspect
				concreteAspect.crosscuttingMembers.addTypeMunger(world.getWeavingSupport().makeCflowCounterFieldAdder(
						localCflowField));

				// Create shadow munger to push stuff onto the stack
				concreteAspect.crosscuttingMembers.addConcreteShadowMunger(Advice.makeCflowEntry(world, concreteEntry, isBelow,
						localCflowField, freeVars == null ? 0 : freeVars.length, innerCflowEntries, inAspect));

				putCflowfield(xcut, concreteEntry, concreteAspect, localCflowField, "counter"); // Remember
				// it
			}

			Pointcut ret = new ConcreteCflowPointcut(concreteAspect, localCflowField, null, true);
			ret.copyLocationFrom(this);
			return ret;
		} else {

			List slots = new ArrayList<>();

			for (int i = 0, len = freeVars.length; i < len; i++) {
				int freeVar = freeVars[i];

				// we don't need to keep state that isn't actually exposed to
				// advice
				// ??? this means that we will store some state that we won't
				// actually use, optimize this later
				if (!bindings.hasKey(freeVar)) {
					continue;
				}

				int formalIndex = bindings.get(freeVar);

				// We need to look in the right place for the type of the
				// formal. Suppose the advice looks like this:
				// before(String s): somePointcut(*,s)
				// where the first argument in somePointcut is of type Number
				// for free variable 0 we want to ask the pointcut for the type
				// of its first argument, if we only
				// ask the advice for the type of its first argument then we'll
				// get the wrong type (pr86903)

				ResolvedPointcutDefinition enclosingDef = bindings.peekEnclosingDefinition();
				ResolvedType formalType = null;

				// Is there a useful enclosing pointcut?
				if (enclosingDef != null && enclosingDef.getParameterTypes().length > 0) {
					formalType = enclosingDef.getParameterTypes()[freeVar].resolve(world);
				} else {
					formalType = bindings.getAdviceSignature().getParameterTypes()[formalIndex].resolve(world);
				}

				ConcreteCflowPointcut.Slot slot = new ConcreteCflowPointcut.Slot(formalIndex, formalType, i);
				slots.add(slot);
			}
			ResolvedMember localCflowField = null;
			Object field = getCflowfield(xcut, concreteEntry, concreteAspect, "stack");
			if (field != null) {
				localCflowField = (ResolvedMember) field;
			} else {

				localCflowField = new ResolvedMemberImpl(Member.FIELD, concreteAspect, Modifier.STATIC | Modifier.PUBLIC,
						NameMangler.cflowStack(xcut), UnresolvedType.forName(NameMangler.CFLOW_STACK_TYPE)
						.getSignature());
				// System.out.println("adding field to: " + inAspect + " field "
				// + cflowField);

				// add field and initializer to inAspect
				// XXX and then that info above needs to be mapped down here to
				// help with
				// XXX getting the exposed state right
				concreteAspect.crosscuttingMembers.addConcreteShadowMunger(Advice.makeCflowEntry(world, concreteEntry, isBelow,
						localCflowField, freeVars.length, innerCflowEntries, inAspect));

				concreteAspect.crosscuttingMembers.addTypeMunger(world.getWeavingSupport()
						.makeCflowStackFieldAdder(localCflowField));
				putCflowfield(xcut, concreteEntry, concreteAspect, localCflowField, "stack");
			}
			Pointcut ret = new ConcreteCflowPointcut(concreteAspect, localCflowField, slots, false);
			ret.copyLocationFrom(this);
			return ret;
		}

	}

	private String getKey(Pointcut p, ResolvedType a, String stackOrCounter) {
		StringBuilder sb = new StringBuilder();
		sb.append(a.getName());
		sb.append("::");
		sb.append(p.toString());
		sb.append("::");
		sb.append(stackOrCounter);
		return sb.toString();
	}

	private Object getCflowfield(CrosscuttingMembers xcut, Pointcut pcutkey, ResolvedType concreteAspect, String stackOrCounter) {
		String key = getKey(pcutkey, concreteAspect, stackOrCounter);
		Object o = null;
		if (isBelow) {
			o = xcut.getCflowBelowFields().get(key);
		} else {
			o = xcut.getCflowFields().get(key);
		}
		// System.err.println("Retrieving for key "+key+" returning "+o);
		return o;
	}

	private void putCflowfield(CrosscuttingMembers xcut, Pointcut pcutkey, ResolvedType concreteAspect, Object o,
			String stackOrCounter) {
		String key = getKey(pcutkey, concreteAspect, stackOrCounter);
		// System.err.println("Storing cflow field for key"+key);
		if (isBelow) {
			xcut.getCflowBelowFields().put(key, o);
		} else {
			xcut.getCflowFields().put(key, o);
		}
	}

	public Object accept(PatternNodeVisitor visitor, Object data) {
		return visitor.visit(this, data);
	}

}