libdwarf/dwarf_init.c

/* Create descriptor from file descriptor for processing file.
   Copyright (C) 2000, 2002 Red Hat, Inc.
   This file is part of Red Hat elfutils.
   Written by Ulrich Drepper <drepper@redhat.com>, 2000.

   Red Hat elfutils is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by the
   Free Software Foundation; version 2 of the License.

   Red Hat elfutils 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 for more details.

   You should have received a copy of the GNU General Public License along
   with Red Hat elfutils; if not, write to the Free Software Foundation,
   Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301 USA.

   Red Hat elfutils is an included package of the Open Invention Network.
   An included package of the Open Invention Network is a package for which
   Open Invention Network licensees cross-license their patents.  No patent
   license is granted, either expressly or impliedly, by designation as an
   included package.  Should you wish to participate in the Open Invention
   Network licensing program, please visit www.openinventionnetwork.com
   <http://www.openinventionnetwork.com>.  */

#ifdef HAVE_CONFIG_H
# include <config.h>
#endif

#include <stddef.h>
#include <sys/stat.h>

#include <libdwarfP.h>


int
dwarf_init (fd, access, errhand, errarg, dbg, error)
     int fd;
     Dwarf_Unsigned access;
     Dwarf_Handler errhand;
     Dwarf_Ptr errarg;
     Dwarf_Debug *dbg;
     Dwarf_Error *error;
{
  Elf *elf;
  Elf_Cmd cmd;
  struct Dwarf_Debug_s newdbg;
  int result = DW_DLV_ERROR;

  switch (access)
    {
    case DW_DLC_READ:
      cmd = ELF_C_READ_MMAP;
      break;
    case DW_DLC_WRITE:
      cmd = ELF_C_WRITE;
      break;
    case DW_DLC_RDWR:
      cmd = ELF_C_RDWR;
      break;
    default:
      /* These are the error values we want to use.  */
      newdbg.dbg_errhand = errhand;
      newdbg.dbg_errarg = errarg;

      __libdwarf_error (&newdbg, error, DW_E_INVALID_ACCESS);
      return DW_DLV_ERROR;
    }

  /* We have to call `elf_version' here since the user might have not
     done it or initialized libelf with a different version.  This
     would break libdwarf since we are using the ELF data structures
     in a certain way.  */
  elf_version (EV_CURRENT);

  /* Get an ELF descriptor.  */
  elf = elf_begin (fd, cmd, NULL);
  if (elf == NULL)
    {
      /* Test why the `elf_begin" call failed.  */
      struct stat64 st;

      /* These are the error values we want to use.  */
      newdbg.dbg_errhand = errhand;
      newdbg.dbg_errarg = errarg;

      if (fstat64 (fd, &st) == 0 && ! S_ISREG (st.st_mode))
	__libdwarf_error (&newdbg, error, DW_E_NO_REGFILE);
      else
	__libdwarf_error (&newdbg, error, DW_E_IO_ERROR);
    }
  else
    {
      /* Do the real work now that we have an ELF descriptor.  */
      result = dwarf_elf_init (elf, access, errhand, errarg, dbg, error);

      /* If this failed, free the resources.  */
      if (result != DW_DLV_OK)
	elf_end (elf);
    }

  return result;
}