/*

 * Copyright (c) 2016, 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 <jni.h>

#include <stdlib.h>

#ifdef WINDOWS

#include <windows.h>

#else

#include <dlfcn.h>

#endif // WINDOWS

#ifdef WINDOWS

  HMODULE handle;

#else

  void* handle;

#endif // WINDOWS

jint(JNICALL *jni_create_java_vm)(JavaVM **, JNIEnv **, void *) = NULL;

// method to perform dlclose on an open dynamic library handle

void closeHandle() {

#ifdef WINDOWS

  if (!FreeLibrary(handle)) {

   fprintf(stderr, "Error occurred while closing handle: 0x%02X\n", GetLastError());

  }

#else

  if (dlclose(handle) != 0) {

    fprintf(stderr, "Error occurred while closing handle: %s\n", dlerror());

  }

#endif // WINDOWS

}

void fail(int code) {

  if (handle) {

    closeHandle();

  }

  exit(code);

}

// method to load the dynamic library libjvm

int loadJVM(const char* path) {

#ifdef WINDOWS

  UINT errorMode = GetErrorMode();

  SetErrorMode(errorMode | SEM_FAILCRITICALERRORS | SEM_NOOPENFILEERRORBOX);

  handle = LoadLibraryA(path);

#else

  handle = dlopen(path, RTLD_LAZY);

#endif // WINDOWS

  if (handle) {

    // find the address of function

#ifdef WINDOWS

    *(void **) (&jni_create_java_vm) = GetProcAddress(handle, "JNI_CreateJavaVM");

#else

    *(void **) (&jni_create_java_vm) = dlsym(handle, "JNI_CreateJavaVM");

#endif // WINDOWS

    if (jni_create_java_vm == NULL) {

      fprintf(stderr, "ERROR: No JNI_CreateJavaVM found: '%s'\n", path);

      return -1;

    }

  } else {

#ifdef WINDOWS

    fprintf(stderr, "ERROR: Can't load JVM library: 0x%02X\n", GetLastError());

#else

    fprintf(stderr, "ERROR: Can't load JVM library: %s\n", dlerror());

#endif // WINDOWS

    return -1;

  }

  return 0;

}

long long unsigned int d2l(double d) {

  union {

    double d;

    long long unsigned int llu;

  } dl;

  dl.d = d;

  return dl.llu;

}

#define print_reg(r) printf("%s = %f (0x%llX)\n", #r, r, d2l(r));

int main(int argc, const char** argv) {

  JavaVM* jvm;

  JNIEnv* env;

  JavaVMInitArgs vm_args;

  // values to trick constant folding

  long long unsigned int vd[32];

  int i;

  int bad_cnt = 0;

  // values occupy fp registers

  // note: suitable code shape is produced only on Windows,

  // and even then registers are corrupted not on every machine

  register double d00;

  register double d01;

  register double d02;

  register double d03;

  register double d04;

  register double d05;

  register double d06;

  register double d07;

  register double d08;

  register double d09;

  register double d10;

  register double d11;

  register double d12;

  register double d13;

  register double d14;

  register double d15;

  if (argc != 2) {

    printf("Usage: FPRegs <jvm_path>");

    fail(2);

  }

  printf("jvm_path = %s\n", argv[1]);

  if (loadJVM(argv[1]) < 0) {

    fail(3);

  }

  vm_args.version = JNI_VERSION_1_8;

  vm_args.ignoreUnrecognized = JNI_FALSE;

  vm_args.options = NULL;

  vm_args.nOptions = 0;

  for(i = 0; i < 16; i++) {

    vd[i] = d2l(100 + i);

  }

  d00 = 100.0;

  d01 = 101.0;

  d02 = 102.0;

  d03 = 103.0;

  d04 = 104.0;

  d05 = 105.0;

  d06 = 106.0;

  d07 = 107.0;

  d08 = 108.0;

  d09 = 109.0;

  d10 = 110.0;

  d11 = 111.0;

  d12 = 112.0;

  d13 = 113.0;

  d14 = 114.0;

  d15 = 115.0;

  printf("BEFORE:\n");

  print_reg(d00);

  print_reg(d01);

  print_reg(d02);

  print_reg(d03);

  print_reg(d04);

  print_reg(d05);

  print_reg(d06);

  print_reg(d07);

  print_reg(d08);

  print_reg(d09);

  print_reg(d10);

  print_reg(d11);

  print_reg(d12);

  print_reg(d13);

  print_reg(d14);

  print_reg(d15);

  if (jni_create_java_vm(&jvm, &env, &vm_args) < 0 ) {

    fprintf(stderr, "ERROR: Can't create JavaVM\n");

    fail(4);

  }

  if (d2l(d00) != vd[0]) bad_cnt++;

  if (d2l(d01) != vd[1]) bad_cnt++;

  if (d2l(d02) != vd[2]) bad_cnt++;

  if (d2l(d03) != vd[3]) bad_cnt++;

  if (d2l(d04) != vd[4]) bad_cnt++;

  if (d2l(d05) != vd[5]) bad_cnt++;

  if (d2l(d06) != vd[6]) bad_cnt++;

  if (d2l(d07) != vd[7]) bad_cnt++;

  if (d2l(d08) != vd[8]) bad_cnt++;

  if (d2l(d09) != vd[9]) bad_cnt++;

  if (d2l(d10) != vd[10]) bad_cnt++;

  if (d2l(d11) != vd[11]) bad_cnt++;

  if (d2l(d12) != vd[12]) bad_cnt++;

  if (d2l(d13) != vd[13]) bad_cnt++;

  if (d2l(d14) != vd[14]) bad_cnt++;

  if (d2l(d15) != vd[15]) bad_cnt++;

  printf("AFTER:\n");

  print_reg(d00);

  print_reg(d01);

  print_reg(d02);

  print_reg(d03);

  print_reg(d04);

  print_reg(d05);

  print_reg(d06);

  print_reg(d07);

  print_reg(d08);

  print_reg(d09);

  print_reg(d10);

  print_reg(d11);

  print_reg(d12);

  print_reg(d13);

  print_reg(d14);

  print_reg(d15);

  printf("%d registers corrupted\n", bad_cnt);

  if (bad_cnt > 0) {

      printf("TEST FAILED");

      fail(1);

  }

  printf("TEST PASSED");

  closeHandle();

  return 0;

}