/*

 * Copyright (c) 2003, 2018, 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.

 */

#include <stdio.h>

#include <string.h>

#include <jvmti.h>

#include "agent_common.h"

#include "JVMTITools.h"

extern "C" {

#define STATUS_FAILED 2

#define PASSED 0

static jvmtiEnv *jvmti = NULL;

static jvmtiCapabilities caps;

#ifdef STATIC_BUILD

JNIEXPORT jint JNICALL Agent_OnLoad_redefclass001(JavaVM *jvm, char *options, void *reserved) {

    return Agent_Initialize(jvm, options, reserved);

}

JNIEXPORT jint JNICALL Agent_OnAttach_redefclass001(JavaVM *jvm, char *options, void *reserved) {

    return Agent_Initialize(jvm, options, reserved);

}

JNIEXPORT jint JNI_OnLoad_redefclass001(JavaVM *jvm, char *options, void *reserved) {

    return JNI_VERSION_1_8;

}

#endif

jint  Agent_Initialize(JavaVM *vm, char *options, void *reserved) {

    jint res;

    jvmtiError err;

    res = vm->GetEnv((void **) &jvmti, JVMTI_VERSION_1_1);

    if (res != JNI_OK) {

        printf("%s: Failed to call GetEnv: error=%d\n", __FILE__, res);

        return JNI_ERR;

    }

    err = jvmti->GetPotentialCapabilities(&caps);

    if (err != JVMTI_ERROR_NONE) {

        printf("(GetPotentialCapabilities) unexpected error: %s (%d)\n",

               TranslateError(err), err);

        return JNI_ERR;

    }

    err = jvmti->AddCapabilities(&caps);

    if (err != JVMTI_ERROR_NONE) {

        printf("(AddCapabilities) unexpected error: %s (%d)\n",

               TranslateError(err), err);

        return JNI_ERR;

    }

    err = jvmti->GetCapabilities(&caps);

    if (err != JVMTI_ERROR_NONE) {

        printf("(GetCapabilities) unexpected error: %s (%d)\n",

               TranslateError(err), err);

        return JNI_ERR;

    }

    if (!caps.can_redefine_classes) {

        printf("Warning: RedefineClasses is not implemented\n");

    }

    return JNI_OK;

}

JNIEXPORT jint JNICALL

Java_nsk_jvmti_RedefineClasses_redefclass001_makeRedefinition(JNIEnv *env,

        jclass cls, jint fl, jclass redefCls, jbyteArray classBytes) {

    jvmtiClassDefinition classDef;

    jvmtiError err;

    if (jvmti == NULL) {

        printf("JVMTI client was not properly loaded!\n");

        return STATUS_FAILED;

    }

    if (!caps.can_redefine_classes) {

        return PASSED;

    }

/* filling the structure jvmtiClassDefinition */

    classDef.klass = redefCls;

    classDef.class_byte_count = env->GetArrayLength(classBytes);

    classDef.class_bytes = (unsigned char *) env->GetByteArrayElements(classBytes, NULL);

    if (fl == 2) {

        printf(">>>>>>>> Invoke RedefineClasses():\n");

        printf("\tnew class byte count=%d\n", classDef.class_byte_count);

    }

    err = jvmti->RedefineClasses(1, &classDef);

    if (err != JVMTI_ERROR_NONE) {

        printf("%s: Failed to call RedefineClasses():\n", __FILE__);

        printf("\tthe function returned error %d: %s\n",

            err, TranslateError(err));

        printf("\tFor more info about this error see the JVMTI spec.\n");

        return STATUS_FAILED;

    }

    if (fl == 2)

        printf("<<<<<<<< RedefineClasses() is successfully done\n");

    return PASSED;

}

}