/*

 * 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 "decoder_windows.hpp"

WindowsDecoder::WindowsDecoder() {

  _dbghelp_handle = NULL;

  _can_decode_in_vm = false;

  _pfnSymGetSymFromAddr64 = NULL;

  _pfnUndecorateSymbolName = NULL;

  _decoder_status = no_error;

  initialize();

}

void WindowsDecoder::initialize() {

  if (!has_error() && _dbghelp_handle == NULL) {

    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;

    }

    HANDLE hProcess = ::GetCurrentProcess();

    _pfnSymSetOptions(SYMOPT_UNDNAME | SYMOPT_DEFERRED_LOADS | SYMOPT_EXACT_SYMBOLS);

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

      _pfnSymGetSymFromAddr64 = NULL;

      _pfnUndecorateSymbolName = NULL;

      ::FreeLibrary(handle);

      _dbghelp_handle = NULL;

      _decoder_status = helper_init_error;

      return;

    }

    // set pdb search paths

    pfn_SymSetSearchPath  _pfn_SymSetSearchPath =

      (pfn_SymSetSearchPath)::GetProcAddress(handle, "SymSetSearchPath");

    pfn_SymGetSearchPath  _pfn_SymGetSearchPath =

      (pfn_SymGetSearchPath)::GetProcAddress(handle, "SymGetSearchPath");

    if (_pfn_SymSetSearchPath != NULL && _pfn_SymGetSearchPath != NULL) {

      char paths[MAX_PATH];

      int  len = sizeof(paths);

      if (!_pfn_SymGetSearchPath(hProcess, paths, len)) {

        paths[0] = '\0';

      } else {

        // available spaces in path buffer

        len -= (int)strlen(paths);

      }

      char tmp_path[MAX_PATH];

      DWORD dwSize;

      HMODULE hJVM = ::GetModuleHandle("jvm.dll");

      tmp_path[0] = '\0';

      // append the path where jvm.dll is located

      if (hJVM != NULL && (dwSize = ::GetModuleFileName(hJVM, tmp_path, sizeof(tmp_path))) > 0) {

        while (dwSize > 0 && tmp_path[dwSize] != '\\') {

          dwSize --;

        }

        tmp_path[dwSize] = '\0';

        if (dwSize > 0 && len > (int)dwSize + 1) {

          strncat(paths, os::path_separator(), 1);

          strncat(paths, tmp_path, dwSize);

          len -= dwSize + 1;

        }

      }

      // append $JRE/bin. Arguments::get_java_home actually returns $JRE

      // path

      char *p = Arguments::get_java_home();

      assert(p != NULL, "empty java home");

      size_t java_home_len = strlen(p);

      if (len > (int)java_home_len + 5) {

        strncat(paths, os::path_separator(), 1);

        strncat(paths, p, java_home_len);

        strncat(paths, "\\bin", 4);

        len -= (int)(java_home_len + 5);

      }

      // append $JDK/bin path if it exists

      assert(java_home_len < MAX_PATH, "Invalid path length");

      // assume $JRE is under $JDK, construct $JDK/bin path and

      // see if it exists or not

      if (strncmp(&p[java_home_len - 3], "jre", 3) == 0) {

        strncpy(tmp_path, p, java_home_len - 3);

        tmp_path[java_home_len - 3] = '\0';

        strncat(tmp_path, "bin", 3);

        // if the directory exists

        DWORD dwAttrib = GetFileAttributes(tmp_path);

        if (dwAttrib != INVALID_FILE_ATTRIBUTES &&

            (dwAttrib & FILE_ATTRIBUTE_DIRECTORY)) {

          // tmp_path should have the same length as java_home_len, since we only

          // replaced 'jre' with 'bin'

          if (len > (int)java_home_len + 1) {

            strncat(paths, os::path_separator(), 1);

            strncat(paths, tmp_path, java_home_len);

          }

        }

      }

      _pfn_SymSetSearchPath(hProcess, paths);

    }

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

     // current function and comparing the result

     address addr = (address)Decoder::demangle;

     char buf[MAX_PATH];

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

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

     }

  }

}

void WindowsDecoder::uninitialize() {

  _pfnSymGetSymFromAddr64 = NULL;

  _pfnUndecorateSymbolName = NULL;

  if (_dbghelp_handle != NULL) {

    ::FreeLibrary(_dbghelp_handle);

  }

  _dbghelp_handle = NULL;

}

bool WindowsDecoder::can_decode_C_frame_in_vm() const {

  return  (!has_error() && _can_decode_in_vm);

}

bool WindowsDecoder::decode(address addr, char *buf, int buflen, int* offset, const char* modulepath)  {

  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 true;

    }

  }

  if (buf != NULL && buflen > 0) buf[0] = '\0';

  if (offset != NULL) *offset = -1;

  return false;

}

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

  return _pfnUndecorateSymbolName != NULL &&

         _pfnUndecorateSymbolName(symbol, buf, buflen, UNDNAME_COMPLETE);

}