/*

 * Copyright (c) 2009, 2015, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

package jdk.vm.ci.meta;

import java.lang.annotation.Annotation;

import jdk.vm.ci.meta.Assumptions.AssumptionResult;

/**

 * Represents a resolved Java type. Types include primitives, objects, {@code void}, and arrays

 * thereof. Types, like fields and methods, are resolved through {@link ConstantPool constant pools}

 * .

 */

public interface ResolvedJavaType extends JavaType, ModifiersProvider {

    /**

     * Checks whether this type has a finalizer method.

     *

     * @return {@code true} if this class has a finalizer

     */

    boolean hasFinalizer();

    /**

     * Checks whether this type has any finalizable subclasses so far. Any decisions based on this

     * information require the registration of a dependency, since this information may change.

     *

     * @return {@code true} if this class has any subclasses with finalizers

     */

    AssumptionResult<Boolean> hasFinalizableSubclass();

    /**

     * Checks whether this type is an interface.

     *

     * @return {@code true} if this type is an interface

     */

    boolean isInterface();

    /**

     * Checks whether this type is an instance class.

     *

     * @return {@code true} if this type is an instance class

     */

    boolean isInstanceClass();

    /**

     * Checks whether this type is an array class.

     *

     * @return {@code true} if this type is an array class

     */

    boolean isArray();

    /**

     * Checks whether this type is primitive.

     *

     * @return {@code true} if this type is primitive

     */

    boolean isPrimitive();

    /**

     * {@inheritDoc}

     * <p>

     * Only the flags specified in the JVM specification will be included in the returned mask. This

     * method is identical to {@link Class#getModifiers()} in terms of the value return for this

     * type.

     */

    int getModifiers();

    /*

     * The setting of the final bit for types is a bit confusing since arrays are marked as final.

     * This method provides a semantically equivalent test that appropriate for types.

     */

    default boolean isLeaf() {

        return getElementalType().isFinalFlagSet();

    }

    /**

     * Checks whether this type is initialized. If a type is initialized it implies that it was

     * {@link #isLinked() linked} and that the static initializer has run.

     *

     * @return {@code true} if this type is initialized

     */

    boolean isInitialized();

    /**

     * Initializes this type.

     */

    void initialize();

    /**

     * Checks whether this type is linked and verified. When a type is linked the static initializer

     * has not necessarily run. An {@link #isInitialized() initialized} type is always linked.

     *

     * @return {@code true} if this type is linked

     */

    boolean isLinked();

    /**

     * Determines if this type is either the same as, or is a superclass or superinterface of, the

     * type represented by the specified parameter. This method is identical to

     * {@link Class#isAssignableFrom(Class)} in terms of the value return for this type.

     */

    boolean isAssignableFrom(ResolvedJavaType other);

    /**

     * Returns true if this type is exactly the type {@link java.lang.Object}.

     */

    default boolean isJavaLangObject() {

        // Removed assertion due to https://bugs.eclipse.org/bugs/show_bug.cgi?id=434442

        return getSuperclass() == null && !isInterface() && getJavaKind() == JavaKind.Object;

    }

    /**

     * Checks whether the specified object is an instance of this type.

     *

     * @param obj the object to test

     * @return {@code true} if the object is an instance of this type

     */

    boolean isInstance(JavaConstant obj);

    /**

     * Returns this type if it is an exact type otherwise returns null. This type is exact if it is

     * void, primitive, final, or an array of a final or primitive type.

     *

     * @return this type if it is exact; {@code null} otherwise

     */

    ResolvedJavaType asExactType();

    /**

     * Gets the super class of this type. If this type represents either the {@code Object} class,

     * an interface, a primitive type, or void, then null is returned. If this object represents an

     * array class then the type object representing the {@code Object} class is returned.

     */

    ResolvedJavaType getSuperclass();

    /**

     * Gets the interfaces implemented or extended by this type. This method is analogous to

     * {@link Class#getInterfaces()} and as such, only returns the interfaces directly implemented

     * or extended by this type.

     */

    ResolvedJavaType[] getInterfaces();

    /**

     * Gets the single implementor of this type. Calling this method on a non-interface type causes

     * an exception.

     * <p>

     * If the compiler uses the result of this method for its compilation, the usage must be guarded

     * because the verifier can not guarantee that the assigned type really implements this

     * interface. Additionally, class loading can invalidate the result of this method.

     *

     * @return {@code null} if there is no implementor, the implementor if there is only one, or

     *         {@code this} if there are more than one.

     */

    ResolvedJavaType getSingleImplementor();

    /**

     * Walks the class hierarchy upwards and returns the least common class that is a superclass of

     * both the current and the given type.

     *

     * @return the least common type that is a super type of both the current and the given type, or

     *         {@code null} if primitive types are involved.

     */

    ResolvedJavaType findLeastCommonAncestor(ResolvedJavaType otherType);

    /**

     * Attempts to get a leaf concrete subclass of this type.

     * <p>

     * For an {@linkplain #isArray() array} type A, the leaf concrete subclass is A if the

     * {@linkplain #getElementalType() elemental} type of A is final (which includes primitive

     * types). Otherwise {@code null} is returned for A.

     * <p>

     * For a non-array type T, the result is the leaf concrete type in the current hierarchy of T.

     * <p>

     * A runtime may decide not to manage or walk a large hierarchy and so the result is

     * conservative. That is, a non-null result is guaranteed to be the leaf concrete class in T's

     * hierarchy <b>at the current point in time</b> but a null result does not necessarily imply

     * that there is no leaf concrete class in T's hierarchy.

     * <p>

     * If the compiler uses the result of this method for its compilation, it must register the

     * {@link AssumptionResult} in its {@link Assumptions} because dynamic class loading can

     * invalidate the result of this method.

     *

     * @return an {@link AssumptionResult} containing the leaf concrete subclass for this type as

     *         described above

     */

    AssumptionResult<ResolvedJavaType> findLeafConcreteSubtype();

    ResolvedJavaType getComponentType();

    default ResolvedJavaType getElementalType() {

        ResolvedJavaType t = this;

        while (t.isArray()) {

            t = t.getComponentType();

        }

        return t;

    }

    ResolvedJavaType getArrayClass();

    /**

     * Resolves the method implementation for virtual dispatches on objects of this dynamic type.

     *

     * @param method the method to select the implementation of

     * @param callerType the caller or context type used to perform access checks

     */

    ResolvedJavaMethod resolveMethod(ResolvedJavaMethod method, ResolvedJavaType callerType);

    /**

     *

     * @param method the method to select the implementation of

     * @param callerType the caller or context type used to perform access checks

     * @return the concrete method that would be selected at runtime, or {@code null} if there is no

     *         concrete implementation of {@code method} in this type or any of its superclasses

     */

    /**

     * Given a {@link ResolvedJavaMethod} A, returns a concrete {@link ResolvedJavaMethod} B that is

     * the only possible unique target for a virtual call on A(). Returns {@code null} if either no

     * such concrete method or more than one such method exists. Returns the method A if A is a

     * concrete method that is not overridden.

     * <p>

     * If the compiler uses the result of this method for its compilation, it must register an

     * assumption because dynamic class loading can invalidate the result of this method.

     *

     * @param method the method A for which a unique concrete target is searched

     * @return the unique concrete target or {@code null} if no such target exists or assumptions

     *         are not supported by this runtime

     */

    AssumptionResult<ResolvedJavaMethod> findUniqueConcreteMethod(ResolvedJavaMethod method);

    /**

     * Returns the instance fields of this class, including

     * {@linkplain ResolvedJavaField#isInternal() internal} fields. A zero-length array is returned

     * for array and primitive types. The order of fields returned by this method is stable. That

     * is, for a single JVM execution the same order is returned each time this method is called. It

     * is also the "natural" order, which means that the JVM would expect the fields in this order

     * if no specific order is given.

     *

     * @param includeSuperclasses if true, then instance fields for the complete hierarchy of this

     *            type are included in the result

     * @return an array of instance fields

     */

    ResolvedJavaField[] getInstanceFields(boolean includeSuperclasses);

    /**

     * Returns the static fields of this class, including

     * {@linkplain ResolvedJavaField#isInternal() internal} fields. A zero-length array is returned

     * for array and primitive types. The order of fields returned by this method is stable. That

     * is, for a single JVM execution the same order is returned each time this method is called.

     */

    ResolvedJavaField[] getStaticFields();

    /**

     * Returns all annotations of this class. If no annotations are present, an array of length 0 is

     * returned.

     */

    Annotation[] getAnnotations();

    /**

     * Returns the annotation for the specified type of this class, if such an annotation is

     * present.

     *

     * @param annotationClass the Class object corresponding to the annotation type

     * @return this element's annotation for the specified annotation type if present on this class,

     *         else {@code null}

     */

    <T extends Annotation> T getAnnotation(Class<T> annotationClass);

    /**

     * Returns the instance field of this class (or one of its super classes) at the given offset,

     * or {@code null} if there is no such field.

     *

     * @param offset the offset of the field to look for

     * @return the field with the given offset, or {@code null} if there is no such field.

     */

    ResolvedJavaField findInstanceFieldWithOffset(long offset, JavaKind expectedKind);

    /**

     * Returns name of source file of this type.

     */

    String getSourceFileName();

    /**

     * Returns {@code true} if the type is a local type.

     */

    boolean isLocal();

    /**

     * Returns {@code true} if the type is a member type.

     */

    boolean isMember();

    /**

     * Returns the enclosing type of this type, if it exists, or {@code null}.

     */

    ResolvedJavaType getEnclosingType();

    /**

     * Returns an array reflecting all the constructors declared by this type. This method is

     * similar to {@link Class#getDeclaredConstructors()} in terms of returned constructors.

     */

    ResolvedJavaMethod[] getDeclaredConstructors();

    /**

     * Returns an array reflecting all the methods declared by this type. This method is similar to

     * {@link Class#getDeclaredMethods()} in terms of returned methods.

     */

    ResolvedJavaMethod[] getDeclaredMethods();

    /**

     * Returns the {@code <clinit>} method for this class if there is one.

     */

    ResolvedJavaMethod getClassInitializer();

    /**

     * Returns true if this type represents an interface and it should be trusted even in places

     * where the JVM verifier would not give any guarantees other than {@link Object}.

     */

    boolean isTrustedInterfaceType();

    default ResolvedJavaMethod findMethod(String name, Signature signature) {

        for (ResolvedJavaMethod method : getDeclaredMethods()) {

            if (method.getName().equals(name) && method.getSignature().equals(signature)) {

                return method;

            }

        }

        return null;

    }

}