1/* Create descriptor from file descriptor for processing file.
2   Copyright (C) 2002, 2003, 2004 Red Hat, Inc.
3   Written by Ulrich Drepper <drepper@redhat.com>, 2002.
4
5   This program is Open Source software; you can redistribute it and/or
6   modify it under the terms of the Open Software License version 1.0 as
7   published by the Open Source Initiative.
8
9   You should have received a copy of the Open Software License along
10   with this program; if not, you may obtain a copy of the Open Software
11   License version 1.0 from http://www.opensource.org/licenses/osl.php or
12   by writing the Open Source Initiative c/o Lawrence Rosen, Esq.,
13   3001 King Ranch Road, Ukiah, CA 95482.   */
14
15#ifdef HAVE_CONFIG_H
16# include <config.h>
17#endif
18
19#include <errno.h>
20#include <stddef.h>
21#include <sys/stat.h>
22
23#include <libdwP.h>
24
25
26Dwarf *
27dwarf_begin (fd, cmd)
28     int fd;
29     Dwarf_Cmd cmd;
30{
31  Elf *elf;
32  Elf_Cmd elfcmd;
33  Dwarf *result = NULL;
34
35  switch (cmd)
36    {
37    case DWARF_C_READ:
38      elfcmd = ELF_C_READ_MMAP;
39      break;
40    case DWARF_C_WRITE:
41      elfcmd = ELF_C_WRITE;
42      break;
43    case DWARF_C_RDWR:
44      elfcmd = ELF_C_RDWR;
45      break;
46    default:
47      /* No valid mode.  */
48      __libdw_seterrno (DWARF_E_INVALID_CMD);
49      return NULL;
50    }
51
52  /* We have to call `elf_version' here since the user might have not
53     done it or initialized libelf with a different version.  This
54     would break libdwarf since we are using the ELF data structures
55     in a certain way.  */
56  elf_version (EV_CURRENT);
57
58  /* Get an ELF descriptor.  */
59  elf = elf_begin (fd, elfcmd, NULL);
60  if (elf == NULL)
61    {
62      /* Test why the `elf_begin" call failed.  */
63      struct stat64 st;
64
65      if (fstat64 (fd, &st) == 0 && ! S_ISREG (st.st_mode))
66	__libdw_seterrno (DWARF_E_NO_REGFILE);
67      else if (errno == EBADF)
68	__libdw_seterrno (DWARF_E_INVALID_FILE);
69      else
70	__libdw_seterrno (DWARF_E_IO_ERROR);
71    }
72  else
73    {
74      /* Do the real work now that we have an ELF descriptor.  */
75      result = dwarf_begin_elf (elf, cmd, NULL);
76
77      /* If this failed, free the resources.  */
78      if (result == NULL)
79	elf_end (elf);
80      else
81	result->free_elf = true;
82    }
83
84  return result;
85}
86