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/*******************************************************************************
* Copyright (c) 2000, 2004 IBM Corporation and others.
* 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:
* IBM Corporation - initial API and implementation
*******************************************************************************/
package org.eclipse.jdt.internal.compiler.lookup;
import org.eclipse.jdt.core.compiler.CharOperation;
import org.eclipse.jdt.internal.compiler.ast.MethodDeclaration;
import org.eclipse.jdt.internal.compiler.ast.TypeDeclaration;
import org.eclipse.jdt.internal.compiler.problem.ProblemReporter;
import org.eclipse.jdt.internal.compiler.util.HashtableOfObject;
public final class MethodVerifier implements TagBits, TypeConstants {
SourceTypeBinding type;
HashtableOfObject inheritedMethods;
HashtableOfObject currentMethods;
ReferenceBinding runtimeException;
ReferenceBinding errorException;
LookupEnvironment environment;
/*
Binding creation is responsible for reporting all problems with types:
- all modifier problems (duplicates & multiple visibility modifiers + incompatible combinations - abstract/final)
- plus invalid modifiers given the context (the verifier did not do this before)
- qualified name collisions between a type and a package (types in default packages are excluded)
- all type hierarchy problems:
- cycles in the superclass or superinterface hierarchy
- an ambiguous, invisible or missing superclass or superinterface
- extending a final class
- extending an interface instead of a class
- implementing a class instead of an interface
- implementing the same interface more than once (ie. duplicate interfaces)
- with nested types:
- shadowing an enclosing type's source name
- defining a static class or interface inside a non-static nested class
- defining an interface as a local type (local types can only be classes)
*/
public MethodVerifier(LookupEnvironment environment) {
this.type = null; // Initialized with the public method verify(SourceTypeBinding)
this.inheritedMethods = null;
this.currentMethods = null;
this.runtimeException = null;
this.errorException = null;
this.environment = environment;
}
private boolean areParametersEqual(MethodBinding one, MethodBinding two) {
TypeBinding[] oneArgs = one.parameters;
TypeBinding[] twoArgs = two.parameters;
if (oneArgs == twoArgs) return true;
int length = oneArgs.length;
if (length != twoArgs.length) return false;
for (int i = 0; i < length; i++)
if (!areTypesEqual(oneArgs[i], twoArgs[i])) return false;
return true;
}
private boolean areTypesEqual(TypeBinding one, TypeBinding two) {
if (one == two) return true;
if (one instanceof ReferenceBinding && two instanceof ReferenceBinding)
// can compare unresolved to resolved reference bindings
return CharOperation.equals(((ReferenceBinding) one).compoundName, ((ReferenceBinding) two).compoundName);
return false; // all other type bindings are identical
}
private void checkAbstractMethod(MethodBinding abstractMethod) {
if (mustImplementAbstractMethod(abstractMethod)) {
TypeDeclaration typeDeclaration = this.type.scope.referenceContext;
if (typeDeclaration != null) {
MethodDeclaration missingAbstractMethod = typeDeclaration.addMissingAbstractMethodFor(abstractMethod);
missingAbstractMethod.scope.problemReporter().abstractMethodMustBeImplemented(this.type, abstractMethod);
} else {
this.problemReporter().abstractMethodMustBeImplemented(this.type, abstractMethod);
}
}
}
private void checkAgainstInheritedMethods(MethodBinding currentMethod, MethodBinding[] methods, int length) {
currentMethod.modifiers |= CompilerModifiers.AccOverriding;
nextMethod : for (int i = length; --i >= 0;) {
MethodBinding inheritedMethod = methods[i];
if (!currentMethod.isAbstract() && inheritedMethod.isAbstract())
currentMethod.modifiers |= CompilerModifiers.AccImplementing;
if (!areTypesEqual(currentMethod.returnType, inheritedMethod.returnType)) {
this.problemReporter(currentMethod).incompatibleReturnType(currentMethod, inheritedMethod);
} else if (currentMethod.isStatic() != inheritedMethod.isStatic()) { // Cannot override a static method or hide an instance method
this.problemReporter(currentMethod).staticAndInstanceConflict(currentMethod, inheritedMethod);
} else {
if (currentMethod.thrownExceptions != NoExceptions)
this.checkExceptions(currentMethod, inheritedMethod);
if (inheritedMethod.isFinal())
this.problemReporter(currentMethod).finalMethodCannotBeOverridden(currentMethod, inheritedMethod);
if (!this.isAsVisible(currentMethod, inheritedMethod))
this.problemReporter(currentMethod).visibilityConflict(currentMethod, inheritedMethod);
if (environment.options.reportDeprecationWhenOverridingDeprecatedMethod && inheritedMethod.isViewedAsDeprecated()) {
if (!currentMethod.isViewedAsDeprecated() || environment.options.reportDeprecationInsideDeprecatedCode) {
// check against the other inherited methods to see if they hide this inheritedMethod
ReferenceBinding declaringClass = inheritedMethod.declaringClass;
if (declaringClass.isInterface())
for (int j = length; --j >= 0;)
if (i != j && methods[j].declaringClass.implementsInterface(declaringClass, false))
continue nextMethod;
this.problemReporter(currentMethod).overridesDeprecatedMethod(currentMethod, inheritedMethod);
}
}
}
}
}
/*
"8.4.4"
Verify that newExceptions are all included in inheritedExceptions.
Assumes all exceptions are valid and throwable.
Unchecked exceptions (compatible with runtime & error) are ignored (see the spec on pg. 203).
*/
private void checkExceptions(MethodBinding newMethod, MethodBinding inheritedMethod) {
ReferenceBinding[] newExceptions = resolvedExceptionTypesFor(newMethod);
ReferenceBinding[] inheritedExceptions = resolvedExceptionTypesFor(inheritedMethod);
for (int i = newExceptions.length; --i >= 0;) {
ReferenceBinding newException = newExceptions[i];
int j = inheritedExceptions.length;
while (--j > -1 && !this.isSameClassOrSubclassOf(newException, inheritedExceptions[j])){/*empty*/}
if (j == -1)
if (!(newException.isCompatibleWith(this.runtimeException()) || newException.isCompatibleWith(this.errorException())))
this.problemReporter(newMethod).incompatibleExceptionInThrowsClause(this.type, newMethod, inheritedMethod, newException);
}
}
private void checkInheritedMethods(MethodBinding[] methods, int length) {
TypeBinding returnType = methods[0].returnType;
int index = length;
while (--index > 0 && areTypesEqual(returnType, methods[index].returnType)){/*empty*/}
if (index > 0) { // All inherited methods do NOT have the same vmSignature
this.problemReporter().inheritedMethodsHaveIncompatibleReturnTypes(this.type, methods, length);
return;
}
MethodBinding concreteMethod = null;
if (!type.isInterface()) { // ignore concrete methods for interfaces
for (int i = length; --i >= 0;) { // Remember that only one of the methods can be non-abstract
if (!methods[i].isAbstract()) {
concreteMethod = methods[i];
break;
}
}
}
if (concreteMethod == null) {
if (this.type.isClass() && !this.type.isAbstract()) {
for (int i = length; --i >= 0;) {
if (mustImplementAbstractMethod(methods[i])) {
TypeDeclaration typeDeclaration = this.type.scope.referenceContext;
if (typeDeclaration != null) {
MethodDeclaration missingAbstractMethod = typeDeclaration.addMissingAbstractMethodFor(methods[0]);
missingAbstractMethod.scope.problemReporter().abstractMethodMustBeImplemented(this.type, methods[0]);
} else {
this.problemReporter().abstractMethodMustBeImplemented(this.type, methods[0]);
}
return;
}
}
}
return;
}
MethodBinding[] abstractMethods = new MethodBinding[length - 1];
index = 0;
for (int i = length; --i >= 0;)
if (methods[i] != concreteMethod)
abstractMethods[index++] = methods[i];
// Remember that interfaces can only define public instance methods
if (concreteMethod.isStatic())
// Cannot inherit a static method which is specified as an instance method by an interface
this.problemReporter().staticInheritedMethodConflicts(type, concreteMethod, abstractMethods);
if (!concreteMethod.isPublic())
// Cannot reduce visibility of a public method specified by an interface
this.problemReporter().inheritedMethodReducesVisibility(type, concreteMethod, abstractMethods);
if (concreteMethod.thrownExceptions != NoExceptions)
for (int i = abstractMethods.length; --i >= 0;)
this.checkExceptions(concreteMethod, abstractMethods[i]);
}
/*
For each inherited method identifier (message pattern - vm signature minus the return type)
if current method exists
if current's vm signature does not match an inherited signature then complain
else compare current's exceptions & visibility against each inherited method
else
if inherited methods = 1
if inherited is abstract && type is NOT an interface or abstract, complain
else
if vm signatures do not match complain
else
find the concrete implementation amongst the abstract methods (can only be 1)
if one exists then
it must be a public instance method
compare concrete's exceptions against each abstract method
else
complain about missing implementation only if type is NOT an interface or abstract
*/
private void checkMethods() {
boolean mustImplementAbstractMethods = this.type.isClass() && !this.type.isAbstract();
boolean skipInheritedMethods = mustImplementAbstractMethods && this.type.superInterfaces() == NoSuperInterfaces
&& this.type.superclass() != null && !this.type.superclass().isAbstract(); // have a single concrete superclass so only check overridden methods
char[][] methodSelectors = this.inheritedMethods.keyTable;
nextSelector : for (int s = methodSelectors.length; --s >= 0;) {
if (methodSelectors[s] == null) continue nextSelector;
MethodBinding[] current = (MethodBinding[]) this.currentMethods.get(methodSelectors[s]);
if (current == null && skipInheritedMethods)
continue nextSelector;
MethodBinding[] inherited = (MethodBinding[]) this.inheritedMethods.valueTable[s];
if (inherited.length == 1 && current == null) { // handle the common case
if (mustImplementAbstractMethods && inherited[0].isAbstract())
checkAbstractMethod(inherited[0]);
continue nextSelector;
}
int index = -1;
MethodBinding[] matchingInherited = new MethodBinding[inherited.length];
if (current != null) {
for (int i = 0, length1 = current.length; i < length1; i++) {
while (index >= 0) matchingInherited[index--] = null; // clear the previous contents of the matching methods
MethodBinding currentMethod = current[i];
for (int j = 0, length2 = inherited.length; j < length2; j++) {
if (inherited[j] != null && areParametersEqual(currentMethod, inherited[j])) {
matchingInherited[++index] = inherited[j];
inherited[j] = null; // do not want to find it again
}
}
if (index >= 0)
this.checkAgainstInheritedMethods(currentMethod, matchingInherited, index + 1); // pass in the length of matching
}
}
for (int i = 0, length = inherited.length; i < length; i++) {
while (index >= 0) matchingInherited[index--] = null; // clear the previous contents of the matching methods
if (inherited[i] != null) {
matchingInherited[++index] = inherited[i];
for (int j = i + 1; j < length; j++) {
if (inherited[j] != null && areParametersEqual(inherited[i], inherited[j])) {
matchingInherited[++index] = inherited[j];
inherited[j] = null; // do not want to find it again
}
}
}
if (index > 0)
this.checkInheritedMethods(matchingInherited, index + 1); // pass in the length of matching
else if (mustImplementAbstractMethods && index == 0 && matchingInherited[0].isAbstract())
checkAbstractMethod(matchingInherited[0]);
}
}
}
private void checkPackagePrivateAbstractMethod(MethodBinding abstractMethod) {
ReferenceBinding superType = this.type.superclass();
char[] selector = abstractMethod.selector;
do {
if (!superType.isValidBinding()) return;
if (!superType.isAbstract()) return; // closer non abstract super type will be flagged instead
MethodBinding[] methods = superType.getMethods(selector);
nextMethod : for (int m = methods.length; --m >= 0;) {
MethodBinding method = methods[m];
if (!areTypesEqual(method.returnType, abstractMethod.returnType) || !areParametersEqual(method, abstractMethod))
continue nextMethod;
if (method.isPrivate() || method.isConstructor() || method.isDefaultAbstract())
continue nextMethod;
if (superType.fPackage == abstractMethod.declaringClass.fPackage) return; // found concrete implementation of abstract method in same package
}
} while ((superType = superType.superclass()) != abstractMethod.declaringClass);
// non visible abstract methods cannot be overridden so the type must be defined abstract
this.problemReporter().abstractMethodCannotBeOverridden(this.type, abstractMethod);
}
/*
Binding creation is responsible for reporting:
- all modifier problems (duplicates & multiple visibility modifiers + incompatible combinations)
- plus invalid modifiers given the context... examples:
- interface methods can only be public
- abstract methods can only be defined by abstract classes
- collisions... 2 methods with identical vmSelectors
- multiple methods with the same message pattern but different return types
- ambiguous, invisible or missing return/argument/exception types
- check the type of any array is not void
- check that each exception type is Throwable or a subclass of it
*/
private void computeInheritedMethods() {
this.inheritedMethods = new HashtableOfObject(51); // maps method selectors to an array of methods... must search to match paramaters & return type
ReferenceBinding[][] interfacesToVisit = new ReferenceBinding[3][];
int lastPosition = -1;
ReferenceBinding[] itsInterfaces = type.superInterfaces();
if (itsInterfaces != NoSuperInterfaces)
interfacesToVisit[++lastPosition] = itsInterfaces;
ReferenceBinding superType = this.type.isClass()
? this.type.superclass()
: this.type.scope.getJavaLangObject(); // check interface methods against Object
MethodBinding[] nonVisibleDefaultMethods = null;
int nonVisibleCount = 0;
while (superType != null) {
if (superType.isValidBinding()) {
if ((itsInterfaces = superType.superInterfaces()) != NoSuperInterfaces) {
if (++lastPosition == interfacesToVisit.length)
System.arraycopy(interfacesToVisit, 0, interfacesToVisit = new ReferenceBinding[lastPosition * 2][], 0, lastPosition);
interfacesToVisit[lastPosition] = itsInterfaces;
}
MethodBinding[] methods = superType.unResolvedMethods();
nextMethod : for (int m = methods.length; --m >= 0;) {
MethodBinding method = methods[m];
if (!(method.isPrivate() || method.isConstructor() || method.isDefaultAbstract())) {
MethodBinding[] existingMethods = (MethodBinding[]) this.inheritedMethods.get(method.selector);
if (existingMethods != null) {
for (int i = 0, length = existingMethods.length; i < length; i++) {
if (areTypesEqual(method.returnType, existingMethods[i].returnType) && areParametersEqual(method, existingMethods[i])) {
if (method.isDefault() && method.isAbstract() && method.declaringClass.fPackage != type.fPackage)
checkPackagePrivateAbstractMethod(method);
continue nextMethod;
}
}
}
if (nonVisibleDefaultMethods != null)
for (int i = 0; i < nonVisibleCount; i++)
if (CharOperation.equals(method.selector, nonVisibleDefaultMethods[i].selector)
&& areTypesEqual(method.returnType, nonVisibleDefaultMethods[i].returnType)
&& areParametersEqual(method, nonVisibleDefaultMethods[i]))
continue nextMethod;
if (!method.isDefault() || method.declaringClass.fPackage == type.fPackage) {
if (existingMethods == null)
existingMethods = new MethodBinding[1];
else
System.arraycopy(existingMethods, 0,
(existingMethods = new MethodBinding[existingMethods.length + 1]), 0, existingMethods.length - 1);
existingMethods[existingMethods.length - 1] = method;
this.inheritedMethods.put(method.selector, existingMethods);
} else {
if (nonVisibleDefaultMethods == null)
nonVisibleDefaultMethods = new MethodBinding[10];
else if (nonVisibleCount == nonVisibleDefaultMethods.length)
System.arraycopy(nonVisibleDefaultMethods, 0,
(nonVisibleDefaultMethods = new MethodBinding[nonVisibleCount * 2]), 0, nonVisibleCount);
nonVisibleDefaultMethods[nonVisibleCount++] = method;
if (method.isAbstract() && !this.type.isAbstract()) // non visible abstract methods cannot be overridden so the type must be defined abstract
this.problemReporter().abstractMethodCannotBeOverridden(this.type, method);
MethodBinding[] current = (MethodBinding[]) this.currentMethods.get(method.selector);
if (current != null) { // non visible methods cannot be overridden so a warning is issued
foundMatch : for (int i = 0, length = current.length; i < length; i++) {
if (areTypesEqual(method.returnType, current[i].returnType) && areParametersEqual(method, current[i])) {
this.problemReporter().overridesPackageDefaultMethod(current[i], method);
break foundMatch;
}
}
}
}
}
}
superType = superType.superclass();
}
}
for (int i = 0; i <= lastPosition; i++) {
ReferenceBinding[] interfaces = interfacesToVisit[i];
for (int j = 0, length = interfaces.length; j < length; j++) {
superType = interfaces[j];
if ((superType.tagBits & InterfaceVisited) == 0) {
superType.tagBits |= InterfaceVisited;
if (superType.isValidBinding()) {
if ((itsInterfaces = superType.superInterfaces()) != NoSuperInterfaces) {
if (++lastPosition == interfacesToVisit.length)
System.arraycopy(interfacesToVisit, 0, interfacesToVisit = new ReferenceBinding[lastPosition * 2][], 0, lastPosition);
interfacesToVisit[lastPosition] = itsInterfaces;
}
MethodBinding[] methods = superType.unResolvedMethods();
for (int m = methods.length; --m >= 0;) { // Interface methods are all abstract public
MethodBinding method = methods[m];
MethodBinding[] existingMethods = (MethodBinding[]) this.inheritedMethods.get(method.selector);
if (existingMethods == null)
existingMethods = new MethodBinding[1];
else
System.arraycopy(existingMethods, 0,
(existingMethods = new MethodBinding[existingMethods.length + 1]), 0, existingMethods.length - 1);
existingMethods[existingMethods.length - 1] = method;
this.inheritedMethods.put(method.selector, existingMethods);
}
}
}
}
}
// bit reinitialization
for (int i = 0; i <= lastPosition; i++) {
ReferenceBinding[] interfaces = interfacesToVisit[i];
for (int j = 0, length = interfaces.length; j < length; j++)
interfaces[j].tagBits &= ~InterfaceVisited;
}
}
private void computeMethods() {
MethodBinding[] methods = type.methods();
int size = methods.length;
this.currentMethods = new HashtableOfObject(size == 0 ? 1 : size); // maps method selectors to an array of methods... must search to match paramaters & return type
for (int m = size; --m >= 0;) {
MethodBinding method = methods[m];
if (!(method.isConstructor() || method.isDefaultAbstract())) { // keep all methods which are NOT constructors or default abstract
MethodBinding[] existingMethods = (MethodBinding[]) this.currentMethods.get(method.selector);
if (existingMethods == null)
existingMethods = new MethodBinding[1];
else
System.arraycopy(existingMethods, 0,
(existingMethods = new MethodBinding[existingMethods.length + 1]), 0, existingMethods.length - 1);
existingMethods[existingMethods.length - 1] = method;
this.currentMethods.put(method.selector, existingMethods);
}
}
}
private ReferenceBinding errorException() {
if (errorException == null)
this.errorException = this.type.scope.getJavaLangError();
return errorException;
}
private boolean isAsVisible(MethodBinding newMethod, MethodBinding inheritedMethod) {
if (inheritedMethod.modifiers == newMethod.modifiers) return true;
if (newMethod.isPublic()) return true; // Covers everything
if (inheritedMethod.isPublic()) return false;
if (newMethod.isProtected()) return true;
if (inheritedMethod.isProtected()) return false;
return !newMethod.isPrivate(); // The inheritedMethod cannot be private since it would not be visible
}
private boolean isSameClassOrSubclassOf(ReferenceBinding testClass, ReferenceBinding superclass) {
do {
if (testClass == superclass) return true;
} while ((testClass = testClass.superclass()) != null);
return false;
}
private boolean mustImplementAbstractMethod(MethodBinding abstractMethod) {
// if the type's superclass is an abstract class, then all abstract methods must be implemented
// otherwise, skip it if the type's superclass must implement any of the inherited methods
ReferenceBinding superclass = this.type.superclass();
ReferenceBinding declaringClass = abstractMethod.declaringClass;
if (declaringClass.isClass()) {
while (superclass.isAbstract() && superclass != declaringClass)
superclass = superclass.superclass(); // find the first concrete superclass or the abstract declaringClass
} else {
if (this.type.implementsInterface(declaringClass, false)) {
if (this.type.isAbstract()) return false; // leave it for the subclasses
if (!superclass.implementsInterface(declaringClass, true)) // only if a superclass does not also implement the interface
return true;
}
while (superclass.isAbstract() && !superclass.implementsInterface(declaringClass, false))
superclass = superclass.superclass(); // find the first concrete superclass or the superclass which implements the interface
}
return superclass.isAbstract(); // if it is a concrete class then we have already reported problem against it
}
private ProblemReporter problemReporter() {
return this.type.scope.problemReporter();
}
private ProblemReporter problemReporter(MethodBinding currentMethod) {
ProblemReporter reporter = problemReporter();
if (currentMethod.declaringClass == type) // only report against the currentMethod if its implemented by the type
reporter.referenceContext = currentMethod.sourceMethod();
return reporter;
}
ReferenceBinding[] resolvedExceptionTypesFor(MethodBinding method) {
ReferenceBinding[] exceptions = method.thrownExceptions;
if ((method.modifiers & CompilerModifiers.AccUnresolved) == 0)
return exceptions;
if (!(method.declaringClass instanceof BinaryTypeBinding))
return TypeConstants.NoExceptions; // safety check
BinaryTypeBinding binaryType = (BinaryTypeBinding) method.declaringClass;
for (int i = exceptions.length; --i >= 0;)
if (exceptions[i] instanceof UnresolvedReferenceBinding)
exceptions[i] = (ReferenceBinding) binaryType.resolveType(exceptions[i]);
return exceptions;
}
private ReferenceBinding runtimeException() {
if (runtimeException == null)
this.runtimeException = this.type.scope.getJavaLangRuntimeException();
return runtimeException;
}
public void verify(SourceTypeBinding someType) {
this.type = someType;
this.computeMethods();
this.computeInheritedMethods();
this.checkMethods();
}
public String toString() {
StringBuffer buffer = new StringBuffer(10);
buffer.append("MethodVerifier for type: "); //$NON-NLS-1$
buffer.append(type.readableName());
buffer.append('\n');
buffer.append("\t-inherited methods: "); //$NON-NLS-1$
buffer.append(this.inheritedMethods);
return buffer.toString();
}
}