/*

 * Copyright (c) 1997, 2010, 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 "precompiled.hpp"

#include "prims/jvm.h"

#include "utilities/decoder.hpp"

HMODULE                   Decoder::_dbghelp_handle = NULL;

bool                      Decoder::_can_decode_in_vm = false;

pfn_SymGetSymFromAddr64   Decoder::_pfnSymGetSymFromAddr64 = NULL;

pfn_UndecorateSymbolName  Decoder::_pfnUndecorateSymbolName = NULL;

void Decoder::initialize() {

  if (!_initialized) {

    _initialized = true;

    HMODULE handle = ::LoadLibrary("dbghelp.dll");

    if (!handle) {

      _decoder_status = helper_not_found;

        return;

    }

    _dbghelp_handle = handle;

    pfn_SymSetOptions _pfnSymSetOptions = (pfn_SymSetOptions)::GetProcAddress(handle, "SymSetOptions");

    pfn_SymInitialize _pfnSymInitialize = (pfn_SymInitialize)::GetProcAddress(handle, "SymInitialize");

    _pfnSymGetSymFromAddr64 = (pfn_SymGetSymFromAddr64)::GetProcAddress(handle, "SymGetSymFromAddr64");

    _pfnUndecorateSymbolName = (pfn_UndecorateSymbolName)GetProcAddress(handle, "UnDecorateSymbolName");

    if (_pfnSymSetOptions == NULL || _pfnSymInitialize == NULL || _pfnSymGetSymFromAddr64 == NULL) {

      _pfnSymGetSymFromAddr64 = NULL;

      _pfnUndecorateSymbolName = NULL;

      ::FreeLibrary(handle);

      _dbghelp_handle = NULL;

      _decoder_status = helper_func_error;

      return;

    }

    _pfnSymSetOptions(SYMOPT_UNDNAME | SYMOPT_DEFERRED_LOADS);

    if (!_pfnSymInitialize(GetCurrentProcess(), NULL, TRUE)) {

      _pfnSymGetSymFromAddr64 = NULL;

      _pfnUndecorateSymbolName = NULL;

      ::FreeLibrary(handle);

      _dbghelp_handle = NULL;

      _decoder_status = helper_init_error;

      return;

    }

     // find out if jvm.dll contains private symbols, by decoding

     // current function and comparing the result

     address addr = (address)Decoder::initialize;

     char buf[MAX_PATH];

     if (decode(addr, buf, sizeof(buf), NULL) == no_error) {

       _can_decode_in_vm = !strcmp(buf, "Decoder::initialize");

     }

  }

}

void Decoder::uninitialize() {

  assert(_initialized, "Decoder not yet initialized");

  _pfnSymGetSymFromAddr64 = NULL;

  _pfnUndecorateSymbolName = NULL;

  if (_dbghelp_handle != NULL) {

    ::FreeLibrary(_dbghelp_handle);

  }

  _initialized = false;

}

bool Decoder::can_decode_C_frame_in_vm() {

  initialize();

  return  _can_decode_in_vm;

}

Decoder::decoder_status Decoder::decode(address addr, char *buf, int buflen, int *offset) {

  assert(_initialized, "Decoder not yet initialized");

  if (_pfnSymGetSymFromAddr64 != NULL) {

    PIMAGEHLP_SYMBOL64 pSymbol;

    char symbolInfo[MAX_PATH + sizeof(IMAGEHLP_SYMBOL64)];

    pSymbol = (PIMAGEHLP_SYMBOL64)symbolInfo;

    pSymbol->MaxNameLength = MAX_PATH;

    pSymbol->SizeOfStruct = sizeof(IMAGEHLP_SYMBOL64);

    DWORD64 displacement;

    if (_pfnSymGetSymFromAddr64(::GetCurrentProcess(), (DWORD64)addr, &displacement, pSymbol)) {

      if (buf != NULL) {

        if (!demangle(pSymbol->Name, buf, buflen)) {

          jio_snprintf(buf, buflen, "%s", pSymbol->Name);

        }

      }

      if (offset != NULL) *offset = (int)displacement;

      return no_error;

    }

  }

  return helper_not_found;

}

bool Decoder::demangle(const char* symbol, char *buf, int buflen) {

  assert(_initialized, "Decoder not yet initialized");

  return _pfnUndecorateSymbolName != NULL &&

         _pfnUndecorateSymbolName(symbol, buf, buflen, UNDNAME_COMPLETE);

}