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      1 /* Create descriptor from file descriptor for processing file.
      2    Copyright (C) 2002, 2003, 2004, 2005 Red Hat, Inc.
      3    This file is part of elfutils.
      4    Written by Ulrich Drepper <drepper (at) redhat.com>, 2002.
      5 
      6    This file is free software; you can redistribute it and/or modify
      7    it under the terms of either
      8 
      9      * the GNU Lesser General Public License as published by the Free
     10        Software Foundation; either version 3 of the License, or (at
     11        your option) any later version
     12 
     13    or
     14 
     15      * the GNU General Public License as published by the Free
     16        Software Foundation; either version 2 of the License, or (at
     17        your option) any later version
     18 
     19    or both in parallel, as here.
     20 
     21    elfutils is distributed in the hope that it will be useful, but
     22    WITHOUT ANY WARRANTY; without even the implied warranty of
     23    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     24    General Public License for more details.
     25 
     26    You should have received copies of the GNU General Public License and
     27    the GNU Lesser General Public License along with this program.  If
     28    not, see <http://www.gnu.org/licenses/>.  */
     29 
     30 #ifdef HAVE_CONFIG_H
     31 # include <config.h>
     32 #endif
     33 
     34 #include <errno.h>
     35 #include <stddef.h>
     36 #include <sys/stat.h>
     37 
     38 #include <libdwP.h>
     39 
     40 
     41 Dwarf *
     42 dwarf_begin (int fd, Dwarf_Cmd cmd)
     43 {
     44   Elf *elf;
     45   Elf_Cmd elfcmd;
     46   Dwarf *result = NULL;
     47 
     48   switch (cmd)
     49     {
     50     case DWARF_C_READ:
     51       elfcmd = ELF_C_READ_MMAP;
     52       break;
     53     case DWARF_C_WRITE:
     54       elfcmd = ELF_C_WRITE;
     55       break;
     56     case DWARF_C_RDWR:
     57       elfcmd = ELF_C_RDWR;
     58       break;
     59     default:
     60       /* No valid mode.  */
     61       __libdw_seterrno (DWARF_E_INVALID_CMD);
     62       return NULL;
     63     }
     64 
     65   /* We have to call `elf_version' here since the user might have not
     66      done it or initialized libelf with a different version.  This
     67      would break libdwarf since we are using the ELF data structures
     68      in a certain way.  */
     69   elf_version (EV_CURRENT);
     70 
     71   /* Get an ELF descriptor.  */
     72   elf = elf_begin (fd, elfcmd, NULL);
     73   if (elf == NULL)
     74     {
     75       /* Test why the `elf_begin" call failed.  */
     76       struct stat st;
     77 
     78       if (fstat (fd, &st) == 0 && ! S_ISREG (st.st_mode))
     79 	__libdw_seterrno (DWARF_E_NO_REGFILE);
     80       else if (errno == EBADF)
     81 	__libdw_seterrno (DWARF_E_INVALID_FILE);
     82       else
     83 	__libdw_seterrno (DWARF_E_IO_ERROR);
     84     }
     85   else
     86     {
     87       /* Do the real work now that we have an ELF descriptor.  */
     88       result = INTUSE(dwarf_begin_elf) (elf, cmd, NULL);
     89 
     90       /* If this failed, free the resources.  */
     91       if (result == NULL)
     92 	elf_end (elf);
     93       else
     94 	result->free_elf = true;
     95     }
     96 
     97   return result;
     98 }
     99 INTDEF(dwarf_begin)
    100