org.eclipse.jdt.internal.compiler.lookup.ImplicitNullAnnotationVerifier Maven / Gradle / Ivy

/*******************************************************************************
 * Copyright (c) 2012, 2015 GK Software AG, IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     Stephan Herrmann - initial API and implementation
 *******************************************************************************/
package org.eclipse.jdt.internal.compiler.lookup;

import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Set;

import org.eclipse.jdt.internal.compiler.ast.ASTNode;
import org.eclipse.jdt.internal.compiler.ast.AbstractMethodDeclaration;
import org.eclipse.jdt.internal.compiler.ast.Argument;
import org.eclipse.jdt.internal.compiler.ast.MethodDeclaration;
import org.eclipse.jdt.internal.compiler.ast.NullAnnotationMatching;
import org.eclipse.jdt.internal.compiler.ast.NullAnnotationMatching.CheckMode;
import org.eclipse.jdt.internal.compiler.impl.CompilerOptions;

/**
 * Extracted slice from MethodVerifier15, which is responsible only for implicit null annotations.
 * First, if enabled, it detects overridden methods from which null annotations are inherited.
 * Next, also default nullness is filled into remaining empty slots.
 * After all implicit annotations have been filled in compatibility is checked and problems are complained.
 */
@SuppressWarnings({"rawtypes", "unchecked"})
public class ImplicitNullAnnotationVerifier {

	/**
	 * Simple record to store nullness info for one argument or return type
	 * while iterating over a set of overridden methods.
	 */
	static class InheritedNonNullnessInfo {
		Boolean inheritedNonNullness;
		MethodBinding annotationOrigin;
		boolean complained;
	}

	// delegate which to ask for recursive analysis of super methods
	// can be 'this', but is never a MethodVerifier (to avoid infinite recursion).
	ImplicitNullAnnotationVerifier buddyImplicitNullAnnotationsVerifier;
	private boolean inheritNullAnnotations;
	protected LookupEnvironment environment;


	public ImplicitNullAnnotationVerifier(LookupEnvironment environment, boolean inheritNullAnnotations) {
		this.buddyImplicitNullAnnotationsVerifier = this;
		this.inheritNullAnnotations = inheritNullAnnotations;
		this.environment = environment;
	}

	// for sub-classes:
	ImplicitNullAnnotationVerifier(LookupEnvironment environment) {
		CompilerOptions options = environment.globalOptions;
		this.buddyImplicitNullAnnotationsVerifier = new ImplicitNullAnnotationVerifier(environment, options.inheritNullAnnotations);
		this.inheritNullAnnotations = options.inheritNullAnnotations;
		this.environment = environment;
	}

	/**
	 * Check and fill in implicit annotations from overridden methods and from default.
	 * Precondition: caller has checked whether annotation-based null analysis is enabled.
	 */
	public void checkImplicitNullAnnotations(MethodBinding currentMethod, AbstractMethodDeclaration srcMethod, boolean complain, Scope scope) {
		// check inherited nullness from superclass and superInterfaces
		try {
			ReferenceBinding currentType = currentMethod.declaringClass;
			if (currentType.id == TypeIds.T_JavaLangObject) {
				return;
			}
			boolean usesTypeAnnotations = scope.environment().usesNullTypeAnnotations();
			boolean needToApplyReturnNonNullDefault =
					currentMethod.hasNonNullDefaultFor(Binding.DefaultLocationReturnType, usesTypeAnnotations);
			boolean needToApplyParameterNonNullDefault =
					currentMethod.hasNonNullDefaultFor(Binding.DefaultLocationParameter, usesTypeAnnotations);
			boolean needToApplyNonNullDefault = needToApplyReturnNonNullDefault | needToApplyParameterNonNullDefault;
			// compatibility & inheritance do not consider constructors / static methods:
			boolean isInstanceMethod = !currentMethod.isConstructor() && !currentMethod.isStatic();
			complain &= isInstanceMethod;
			if (!needToApplyNonNullDefault 
					&& !complain 
					&& !(this.inheritNullAnnotations && isInstanceMethod)) {
				return; // short cut, no work to be done
			}

			if (isInstanceMethod) {
				List superMethodList = new ArrayList();
				
				// need super types connected:
				if (currentType instanceof SourceTypeBinding && !currentType.isHierarchyConnected() && !currentType.isAnonymousType()) {
					((SourceTypeBinding) currentType).scope.connectTypeHierarchy();
				}

				int paramLen = currentMethod.parameters.length;
				findAllOverriddenMethods(currentMethod.original(), currentMethod.selector, paramLen,
								currentType, new HashSet(), superMethodList);
				
				// prepare interim storage for nullness info so we don't pollute currentMethod before we know its conflict-free: 
				InheritedNonNullnessInfo[] inheritedNonNullnessInfos = new InheritedNonNullnessInfo[paramLen+1]; // index 0 is for the return type
				for (int i=0; i= 0;) {
					MethodBinding currentSuper = (MethodBinding) superMethodList.get(i);
					if ((currentSuper.tagBits & TagBits.IsNullnessKnown) == 0) {
						// recurse to prepare currentSuper
						checkImplicitNullAnnotations(currentSuper, null, false, scope); // TODO (stephan) complain=true if currentSuper is source method??
					}
					checkNullSpecInheritance(currentMethod, srcMethod, needToApplyReturnNonNullDefault, needToApplyParameterNonNullDefault, complain, currentSuper, null, scope, inheritedNonNullnessInfos);
					needToApplyNonNullDefault = false;
				}
				
				// transfer collected information into currentMethod:
				InheritedNonNullnessInfo info = inheritedNonNullnessInfos[0];
				if (!info.complained) {
					long tagBits = 0;
					if (info.inheritedNonNullness == Boolean.TRUE) {
						tagBits = TagBits.AnnotationNonNull;
					} else if (info.inheritedNonNullness == Boolean.FALSE) {
						tagBits = TagBits.AnnotationNullable;
					}
					if (tagBits != 0) {
						if (!usesTypeAnnotations) {
							currentMethod.tagBits |= tagBits;
						} else {
							if (!currentMethod.returnType.isBaseType()) {
								LookupEnvironment env = scope.environment();
								currentMethod.returnType = env.createAnnotatedType(currentMethod.returnType, env.nullAnnotationsFromTagBits(tagBits));
							}
						}
					}
				}
				for (int i=0; i and X as the same 'type'
		if (one.isParameterizedType() && two.isParameterizedType())
			return one.isEquivalentTo(two) && two.isEquivalentTo(one);

		// Can skip this since we resolved each method before comparing it, see computeSubstituteMethod()
		//	if (one instanceof UnresolvedReferenceBinding)
		//		return ((UnresolvedReferenceBinding) one).resolvedType == two;
		//	if (two instanceof UnresolvedReferenceBinding)
		//		return ((UnresolvedReferenceBinding) two).resolvedType == one;
		return false; // all other type bindings are identical
	}
}