/*

 * Copyright (c) 1997, 2011, 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"

#if !defined(_WINDOWS) && !defined(__APPLE__)

#include "memory/allocation.inline.hpp"

#include "utilities/elfSymbolTable.hpp"

ElfSymbolTable::ElfSymbolTable(FILE* file, Elf_Shdr shdr) {

  assert(file, "null file handle");

  m_symbols = NULL;

  m_next = NULL;

  m_file = file;

  m_status = Decoder::no_error;

  // try to load the string table

  long cur_offset = ftell(file);

  if (cur_offset != -1) {

    // call malloc so we can back up if memory allocation fails.

    m_symbols = (Elf_Sym*)os::malloc(shdr.sh_size);

    if (m_symbols) {

      if (fseek(file, shdr.sh_offset, SEEK_SET) ||

        fread((void*)m_symbols, shdr.sh_size, 1, file) != 1 ||

        fseek(file, cur_offset, SEEK_SET)) {

        m_status = Decoder::file_invalid;

        os::free(m_symbols);

        m_symbols = NULL;

      }

    }

    if (m_status == Decoder::no_error) {

      memcpy(&m_shdr, &shdr, sizeof(Elf_Shdr));

    }

  } else {

    m_status = Decoder::file_invalid;

  }

}

ElfSymbolTable::~ElfSymbolTable() {

  if (m_symbols != NULL) {

    os::free(m_symbols);

  }

  if (m_next != NULL) {

    delete m_next;

  }

}

Decoder::decoder_status ElfSymbolTable::lookup(address addr, int* stringtableIndex, int* posIndex, int* offset) {

  assert(stringtableIndex, "null string table index pointer");

  assert(posIndex, "null string table offset pointer");

  assert(offset, "null offset pointer");

  if (m_status != Decoder::no_error) {

    return m_status;

  }

  address pc = 0;

  size_t  sym_size = sizeof(Elf_Sym);

  assert((m_shdr.sh_size % sym_size) == 0, "check size");

  int count = m_shdr.sh_size / sym_size;

  if (m_symbols != NULL) {

    for (int index = 0; index < count; index ++) {

      if (STT_FUNC == ELF_ST_TYPE(m_symbols[index].st_info)) {

        address sym_addr = (address)m_symbols[index].st_value;

        if (sym_addr < addr && (addr - sym_addr) < *offset) {

          pc = (address)m_symbols[index].st_value;

          *offset = (int)(addr - pc);

          *posIndex = m_symbols[index].st_name;

          *stringtableIndex = m_shdr.sh_link;

        }

      }

    }

  } else {

    long cur_pos;

    if ((cur_pos = ftell(m_file)) == -1 ||

      fseek(m_file, m_shdr.sh_offset, SEEK_SET)) {

      m_status = Decoder::file_invalid;

      return m_status;

    }

    Elf_Sym sym;

    for (int index = 0; index < count; index ++) {

      if (fread(&sym, sym_size, 1, m_file) == 1) {

        if (STT_FUNC == ELF_ST_TYPE(sym.st_info)) {

          address sym_addr = (address)sym.st_value;

          if (sym_addr < addr && (addr - sym_addr) < *offset) {

            pc = (address)sym.st_value;

            *offset = (int)(addr - pc);

            *posIndex = sym.st_name;

            *stringtableIndex = m_shdr.sh_link;

          }

        }

      } else {

        m_status = Decoder::file_invalid;

        return m_status;

      }

    }

    fseek(m_file, cur_pos, SEEK_SET);

  }

  return m_status;

}

#endif // _WINDOWS