/*

 * 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 <inttypes.h>

#include <stdio.h>

#include <string.h>

#include "jvmti.h"

#include "agent_common.h"

#include "jni_tools.h"

#include "JVMTITools.h"

#ifdef __cplusplus

extern "C" {

#endif

#ifndef JNI_ENV_ARG

#ifdef __cplusplus

#define JNI_ENV_ARG(x, y) y

#define JNI_ENV_PTR(x) x

#else

#define JNI_ENV_ARG(x,y) x, y

#define JNI_ENV_PTR(x) (*x)

#endif

#endif

#define PASSED 0

#define STATUS_FAILED 2

typedef struct {

    char *name;

    char *sig;

    jlocation loc;

} entry_info;

static jvmtiEnv *jvmti = NULL;

static jvmtiCapabilities caps;

static jvmtiEventCallbacks callbacks;

static jint result = PASSED;

static jboolean printdump = JNI_FALSE;

static size_t eventsExpected = 0;

static size_t eventsCount = 0;

static entry_info entries[] = {

    {"check", "()I", -1},

    {"dummy", "()V", 0},

    {"chain", "()V", -1}

};

void JNICALL MethodEntry(jvmtiEnv *jvmti_env, JNIEnv *env,

        jthread thr, jmethodID method) {

    jvmtiError err;

    char *cls_sig, *generic;

    entry_info entry;

    jclass cls;

    jmethodID mid;

    char buffer[32];

    err = (*jvmti_env)->GetMethodDeclaringClass(jvmti_env, method, &cls);

    if (err != JVMTI_ERROR_NONE) {

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

               TranslateError(err), err);

        result = STATUS_FAILED;

    }

    err = (*jvmti_env)->GetClassSignature(jvmti_env, cls, &cls_sig, &generic);

    if (err != JVMTI_ERROR_NONE) {

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

               TranslateError(err), err);

        result = STATUS_FAILED;

    }

    if (cls_sig != NULL &&

            strcmp(cls_sig, "Lnsk/jvmti/MethodEntry/mentry001;") == 0) {

        if (printdump == JNI_TRUE) {

            printf(">>> retrieving method entry info ...\n");

        }

        err = (*jvmti_env)->GetMethodName(jvmti_env, method,

            &entry.name, &entry.sig, &generic);

        if (err != JVMTI_ERROR_NONE) {

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

                   TranslateError(err), err);

            result = STATUS_FAILED;

        }

        err = (*jvmti_env)->GetFrameLocation(jvmti_env, thr, 0, &mid, &entry.loc);

        if (err != JVMTI_ERROR_NONE) {

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

                   TranslateError(err), err);

            result = STATUS_FAILED;

        }

        if (printdump == JNI_TRUE) {

            printf(">>>      class: \"%s\"\n", cls_sig);

            printf(">>>     method: \"%s%s\"\n", entry.name, entry.sig);

            printf(">>>   location: %s\n", jlong_to_string(entry.loc, buffer));

            printf(">>> ... done\n");

        }

        if (eventsCount < sizeof(entries)/sizeof(entry_info)) {

            if (entry.name == NULL ||

                    strcmp(entry.name, entries[eventsCount].name) != 0) {

                printf("(entry#%" PRIuPTR ") wrong method name: \"%s\"",

                       eventsCount, entry.name);

                printf(", expected: \"%s\"\n", entries[eventsCount].name);

                result = STATUS_FAILED;

            }

            if (entry.sig == NULL ||

                    strcmp(entry.sig, entries[eventsCount].sig) != 0) {

                printf("(entry#%" PRIuPTR ") wrong method sig: \"%s\"",

                       eventsCount, entry.sig);

                printf(", expected: \"%s\"\n", entries[eventsCount].sig);

                result = STATUS_FAILED;

            }

            if (entry.loc != entries[eventsCount].loc) {

                printf("(entry#%" PRIuPTR ") wrong location: %s",

                       eventsCount, jlong_to_string(entry.loc, buffer));

                printf(", expected: %s\n",

                       jlong_to_string(entries[eventsCount].loc, buffer));

                result = STATUS_FAILED;

            }

        } else {

            printf("Unexpected method entry catched:");

            printf("     class: \"%s\"\n", cls_sig);

            printf("    method: \"%s%s\"\n", entry.name, entry.sig);

            printf("  location: %s\n", jlong_to_string(entry.loc, buffer));

            result = STATUS_FAILED;

        }

        eventsCount++;

    }

}

#ifdef STATIC_BUILD

JNIEXPORT jint JNICALL Agent_OnLoad_mentry001(JavaVM *jvm, char *options, void *reserved) {

    return Agent_Initialize(jvm, options, reserved);

}

JNIEXPORT jint JNICALL Agent_OnAttach_mentry001(JavaVM *jvm, char *options, void *reserved) {

    return Agent_Initialize(jvm, options, reserved);

}

JNIEXPORT jint JNI_OnLoad_mentry001(JavaVM *jvm, char *options, void *reserved) {

    return JNI_VERSION_1_8;

}

#endif

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

    jvmtiError err;

    jint res;

    if (options != NULL && strcmp(options, "printdump") == 0) {

        printdump = JNI_TRUE;

    }

    res = JNI_ENV_PTR(jvm)->GetEnv(JNI_ENV_ARG(jvm, (void **) &jvmti),

        JVMTI_VERSION_1_1);

    if (res != JNI_OK || jvmti == NULL) {

        printf("Wrong result of a valid call to GetEnv!\n");

        return JNI_ERR;

    }

    err = (*jvmti)->GetPotentialCapabilities(jvmti, &caps);

    if (err != JVMTI_ERROR_NONE) {

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

               TranslateError(err), err);

        return JNI_ERR;

    }

    err = (*jvmti)->AddCapabilities(jvmti, &caps);

    if (err != JVMTI_ERROR_NONE) {

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

               TranslateError(err), err);

        return JNI_ERR;

    }

    err = (*jvmti)->GetCapabilities(jvmti, &caps);

    if (err != JVMTI_ERROR_NONE) {

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

               TranslateError(err), err);

        return JNI_ERR;

    }

    if (caps.can_generate_method_entry_events) {

        callbacks.MethodEntry = &MethodEntry;

        err = (*jvmti)->SetEventCallbacks(jvmti, &callbacks, sizeof(callbacks));

        if (err != JVMTI_ERROR_NONE) {

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

                   TranslateError(err), err);

            return JNI_ERR;

        }

    } else {

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

    }

    return JNI_OK;

}

JNIEXPORT void JNICALL

Java_nsk_jvmti_MethodEntry_mentry001_enable(JNIEnv *env, jclass cls) {

    jvmtiError err;

    if (jvmti == NULL) {

        return;

    }

    if (!caps.can_generate_method_entry_events) {

        return;

    }

    err = (*jvmti)->SetEventNotificationMode(jvmti, JVMTI_ENABLE,

            JVMTI_EVENT_METHOD_ENTRY, NULL);

    if (err == JVMTI_ERROR_NONE) {

        eventsExpected = sizeof(entries)/sizeof(entry_info);

    } else {

        printf("Failed to enable JVMTI_EVENT_METHOD_ENTRY event: %s (%d)\n",

               TranslateError(err), err);

        result = STATUS_FAILED;

    }

}

JNIEXPORT jint JNICALL

Java_nsk_jvmti_MethodEntry_mentry001_check(JNIEnv *env, jclass cls) {

    jmethodID mid;

    mid = JNI_ENV_PTR(env)->GetStaticMethodID(JNI_ENV_ARG(env, cls),

        "dummy", "()V");

    if (mid == NULL) {

        printf("Cannot find metod \"dummy()\"!\n");

        return STATUS_FAILED;

    }

    JNI_ENV_PTR(env)->CallStaticVoidMethod(JNI_ENV_ARG(env, cls), mid);

    if (eventsCount != eventsExpected) {

        printf("Wrong number of MethodEntry events: %" PRIuPTR ", expected: %" PRIuPTR "\n",

            eventsCount, eventsExpected);

        result = STATUS_FAILED;

    }

    return result;

}

JNIEXPORT void JNICALL

Java_nsk_jvmti_MethodEntry_mentry001_chain(JNIEnv *env, jclass cls) {

    jvmtiError err;

    if (jvmti == NULL) {

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

        result = STATUS_FAILED;

        return;

    }

    if (!caps.can_generate_method_entry_events) {

        return;

    }

    err = (*jvmti)->SetEventNotificationMode(jvmti, JVMTI_DISABLE,

            JVMTI_EVENT_METHOD_ENTRY, NULL);

    if (err != JVMTI_ERROR_NONE) {

        printf("Failed to disable JVMTI_EVENT_METHOD_ENTRY event: %s (%d)\n",

               TranslateError(err), err);

        result = STATUS_FAILED;

    }

}

#ifdef __cplusplus

}

#endif