/*

 * 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

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 */

package jdk.vm.ci.meta;

import java.lang.annotation.Annotation;

import java.lang.reflect.AnnotatedElement;

import java.lang.reflect.Array;

import java.lang.reflect.Method;

import java.lang.reflect.Modifier;

import java.lang.reflect.Type;

/**

 * Represents a resolved Java method. Methods, like fields and types, are resolved through

 * {@link ConstantPool constant pools}.

 */

public interface ResolvedJavaMethod extends JavaMethod, InvokeTarget, ModifiersProvider, AnnotatedElement {

    /**

     * Returns the bytecode of this method, if the method has code. The returned byte array does not

     * contain breakpoints or non-Java bytecodes. This may return null if the

     *

     * The contained constant pool indices may not be the ones found in the original class file but

     * they can be used with the JVMCI API (e.g. methods in {@link ConstantPool}).

     *

     * @return the bytecode of the method, or {@code null} if {@code getCodeSize() == 0} or if the

     *         code is not ready.

     */

    byte[] getCode();

    /**

     * Returns the size of the bytecode of this method, if the method has code. This is equivalent

     * to {@link #getCode()}. {@code length} if the method has code.

     *

     * @return the size of the bytecode in bytes, or 0 if no bytecode is available

     */

    int getCodeSize();

    /**

     * Returns the {@link ResolvedJavaType} object representing the class or interface that declares

     * this method.

     */

    @Override

    ResolvedJavaType getDeclaringClass();

    /**

     * Returns the maximum number of locals used in this method's bytecodes.

     */

    int getMaxLocals();

    /**

     * Returns the maximum number of stack slots used in this method's bytecodes.

     */

    int getMaxStackSize();

    default boolean isFinal() {

        return ModifiersProvider.super.isFinalFlagSet();

    }

    /**

     * Determines if this method is a synthetic method as defined by the Java Language

     * Specification.

     */

    boolean isSynthetic();

    /**

     * Checks that the method is a

     * <a href="http://docs.oracle.com/javase/specs/jvms/se8/html/jvms-4.html#jvms-4.6">varargs</a>

     * method.

     *

     * @return whether the method is a varargs method

     */

    boolean isVarArgs();

    /**

     * Checks that the method is a

     * <a href="http://docs.oracle.com/javase/specs/jvms/se8/html/jvms-4.html#jvms-4.6">bridge</a>

     * method.

     *

     * @return whether the method is a bridge method

     */

    boolean isBridge();

    /**

     * Returns {@code true} if this method is a default method; returns {@code false} otherwise.

     *

     * A default method is a public non-abstract instance method, that is, a non-static method with

     * a body, declared in an interface type.

     *

     * @return true if and only if this method is a default method as defined by the Java Language

     *         Specification.

     */

    boolean isDefault();

    /**

     * Checks whether this method is a class initializer.

     *

     * @return {@code true} if the method is a class initializer

     */

    boolean isClassInitializer();

    /**

     * Checks whether this method is a constructor.

     *

     * @return {@code true} if the method is a constructor

     */

    boolean isConstructor();

    /**

     * Checks whether this method can be statically bound (usually, that means it is final or

     * private or static, but not abstract, or the declaring class is final).

     *

     * @return {@code true} if this method can be statically bound

     */

    boolean canBeStaticallyBound();

    /**

     * Returns the list of exception handlers for this method.

     */

    ExceptionHandler[] getExceptionHandlers();

    /**

     * Returns a stack trace element for this method and a given bytecode index.

     */

    StackTraceElement asStackTraceElement(int bci);

    /**

     * Returns an object that provides access to the profiling information recorded for this method.

     */

    default ProfilingInfo getProfilingInfo() {

        return getProfilingInfo(true, true);

    }

    /**

     * Returns an object that provides access to the profiling information recorded for this method.

     *

     * @param includeNormal if true,

     *            {@linkplain ProfilingInfo#getDeoptimizationCount(DeoptimizationReason)

     *            deoptimization counts} will include deoptimization that happened during execution

     *            of standard non-osr methods.

     * @param includeOSR if true,

     *            {@linkplain ProfilingInfo#getDeoptimizationCount(DeoptimizationReason)

     *            deoptimization counts} will include deoptimization that happened during execution

     *            of on-stack-replacement methods.

     */

    ProfilingInfo getProfilingInfo(boolean includeNormal, boolean includeOSR);

    /**

     * Invalidates the profiling information and restarts profiling upon the next invocation.

     */

    void reprofile();

    /**

     * Returns the constant pool of this method.

     */

    ConstantPool getConstantPool();

    /**

     * A {@code Parameter} provides information about method parameters.

     */

    class Parameter implements AnnotatedElement {

        private final String name;

        private final ResolvedJavaMethod method;

        private final int modifiers;

        private final int index;

        /**

         * Constructor for {@code Parameter}.

         *

         * @param name the name of the parameter or {@code null} if there is no

         *            {@literal MethodParameters} class file attribute providing a non-empty name

         *            for the parameter

         * @param modifiers the modifier flags for the parameter

         * @param method the method which defines this parameter

         * @param index the index of the parameter

         */

        public Parameter(String name,

                        int modifiers,

                        ResolvedJavaMethod method,

                        int index) {

            assert name == null || !name.isEmpty();

            this.name = name;

            this.modifiers = modifiers;

            this.method = method;

            this.index = index;

        }

        /**

         * Gets the name of the parameter. If the parameter's name is {@linkplain #isNamePresent()

         * present}, then this method returns the name provided by the class file. Otherwise, this

         * method synthesizes a name of the form argN, where N is the index of the parameter in the

         * descriptor of the method which declares the parameter.

         *

         * @return the name of the parameter, either provided by the class file or synthesized if

         *         the class file does not provide a name

         */

        public String getName() {

            if (name == null) {

                return "arg" + index;

            } else {

                return name;

            }

        }

        /**

         * Gets the method declaring the parameter.

         */

        public ResolvedJavaMethod getDeclaringMethod() {

            return method;

        }

        /**

         * Get the modifier flags for the parameter.

         */

        public int getModifiers() {

            return modifiers;

        }

        /**

         * Gets the kind of the parameter.

         */

        public JavaKind getKind() {

            return method.getSignature().getParameterKind(index);

        }

        /**

         * Gets the formal type of the parameter.

         */

        public Type getParameterizedType() {

            return method.getGenericParameterTypes()[index];

        }

        /**

         * Gets the type of the parameter.

         */

        public JavaType getType() {

            return method.getSignature().getParameterType(index, method.getDeclaringClass());

        }

        /**

         * Determines if the parameter has a name according to a {@literal MethodParameters} class

         * file attribute.

         *

         * @return true if and only if the parameter has a name according to the class file.

         */

        public boolean isNamePresent() {

            return name != null;

        }

        /**

         * Determines if the parameter represents a variable argument list.

         */

        public boolean isVarArgs() {

            return method.isVarArgs() && index == method.getSignature().getParameterCount(false) - 1;

        }

        @Override

        public <T extends Annotation> T getAnnotation(Class<T> annotationClass) {

            return method.getParameterAnnotations(annotationClass)[index];

        }

        @Override

        public Annotation[] getAnnotations() {

            return method.getParameterAnnotations()[index];

        }

        @Override

        public Annotation[] getDeclaredAnnotations() {

            return getAnnotations();

        }

        @Override

        public String toString() {

            Type type = getParameterizedType();

            String typename = type.getTypeName();

            if (isVarArgs()) {

                typename = typename.replaceFirst("\\[\\]$", "...");

            }

            final StringBuilder sb = new StringBuilder(Modifier.toString(getModifiers()));

            if (sb.length() != 0) {

                sb.append(' ');

            }

            return sb.append(typename).append(' ').append(getName()).toString();

        }

        @Override

        public boolean equals(Object obj) {

            if (obj instanceof Parameter) {

                Parameter other = (Parameter) obj;

                return (other.method.equals(method) && other.index == index);

            }

            return false;

        }

        @Override

        public int hashCode() {

            return method.hashCode() ^ index;

        }

    }

    /**

     * Returns an array of {@code Parameter} objects that represent all the parameters to this

     * method. Returns an array of length 0 if this method has no parameters. Returns {@code null}

     * if the parameter information is unavailable.

     */

    default Parameter[] getParameters() {

        return null;

    }

    /**

     * Returns an array of arrays that represent the annotations on the formal parameters, in

     * declaration order, of this method.

     *

     * @see Method#getParameterAnnotations()

     */

    Annotation[][] getParameterAnnotations();

    /**

     * Returns an array of {@link Type} objects that represent the formal parameter types, in

     * declaration order, of this method.

     *

     * @see Method#getGenericParameterTypes()

     */

    Type[] getGenericParameterTypes();

    /**

     * Returns {@code true} if this method is not excluded from inlining and has associated Java

     * bytecodes (@see {@link ResolvedJavaMethod#hasBytecodes()}).

     */

    boolean canBeInlined();

    /**

     * Determines if this method is targeted by a VM directive (e.g.,

     * {@code -XX:CompileCommand=dontinline,<pattern>}) or VM recognized annotation (e.g.,

     * {@code jdk.internal.vm.annotation.DontInline}) that specifies it should not be inlined.

     */

    boolean hasNeverInlineDirective();

    /**

     * Returns {@code true} if the inlining of this method should be forced.

     */

    boolean shouldBeInlined();

    /**

     * Returns the LineNumberTable of this method or null if this method does not have a line

     * numbers table.

     */

    LineNumberTable getLineNumberTable();

    /**

     * Returns the local variable table of this method or null if this method does not have a local

     * variable table.

     */

    LocalVariableTable getLocalVariableTable();

    /**

     * Gets the encoding of (that is, a constant representing the value of) this method.

     *

     * @return a constant representing a reference to this method

     */

    Constant getEncoding();

    /**

     * Checks if this method is present in the virtual table for subtypes of the specified

     * {@linkplain ResolvedJavaType type}.

     *

     * @return true is this method is present in the virtual table for subtypes of this type.

     */

    boolean isInVirtualMethodTable(ResolvedJavaType resolved);

    /**

     * Gets the annotation of a particular type for a formal parameter of this method.

     *

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

     * @param parameterIndex the index of a formal parameter of {@code method}

     * @return the annotation of type {@code annotationClass} for the formal parameter present, else

     *         null

     * @throws IndexOutOfBoundsException if {@code parameterIndex} does not denote a formal

     *             parameter

     */

    default <T extends Annotation> T getParameterAnnotation(Class<T> annotationClass, int parameterIndex) {

        if (parameterIndex >= 0) {

            Annotation[][] parameterAnnotations = getParameterAnnotations();

            for (Annotation a : parameterAnnotations[parameterIndex]) {

                if (a.annotationType() == annotationClass) {

                    return annotationClass.cast(a);

                }

            }

        }

        return null;

    }

    default JavaType[] toParameterTypes() {

        JavaType receiver = isStatic() || isConstructor() ? null : getDeclaringClass();

        return getSignature().toParameterTypes(receiver);

    }

    /**

     * Gets the annotations of a particular type for the formal parameters of this method.

     *

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

     * @return the annotation of type {@code annotationClass} (if any) for each formal parameter

     *         present

     */

    @SuppressWarnings("unchecked")

    default <T extends Annotation> T[] getParameterAnnotations(Class<T> annotationClass) {

        Annotation[][] parameterAnnotations = getParameterAnnotations();

        T[] result = (T[]) Array.newInstance(annotationClass, parameterAnnotations.length);

        for (int i = 0; i < parameterAnnotations.length; i++) {

            for (Annotation a : parameterAnnotations[i]) {

                if (a.annotationType() == annotationClass) {

                    result[i] = annotationClass.cast(a);

                }

            }

        }

        return result;

    }

    /**

     *

     */

    default boolean hasBytecodes() {

    }

    /**

     * Checks whether the method has a receiver parameter - i.e., whether it is not static.

     *

     * @return whether the method has a receiver parameter

     */

    default boolean hasReceiver() {

        return !isStatic();

    }

    /**

     * Determines if this method is {@link java.lang.Object#Object()}.

     */

    default boolean isJavaLangObjectInit() {

        return getDeclaringClass().isJavaLangObject() && getName().equals("<init>");

    }

    SpeculationLog getSpeculationLog();

}