2003-05-02 Michael Snyder <msnyder@redhat.com>

[binutils.git] / bfd / bfd.c

/* Generic BFD library interface and support routines.
   Copyright 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
   2000, 2001, 2002, 2003
   Free Software Foundation, Inc.
   Written by Cygnus Support.

   This file is part of BFD, the Binary File Descriptor library.

   This program 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; either version 2 of the License, or
   (at your option) any later version.

   This program 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 this program; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */

/*
SECTION
        <<typedef bfd>>

        A BFD has type <<bfd>>; objects of this type are the
        cornerstone of any application using BFD. Using BFD
        consists of making references though the BFD and to data in the BFD.

        Here is the structure that defines the type <<bfd>>.  It
        contains the major data about the file and pointers
        to the rest of the data.

CODE_FRAGMENT
.
.struct bfd
.{
.  {* A unique identifier of the BFD  *}
.  unsigned int id;
.
.  {* The filename the application opened the BFD with.  *}
.  const char *filename;
.
.  {* A pointer to the target jump table.  *}
.  const struct bfd_target *xvec;
.
.  {* To avoid dragging too many header files into every file that
.     includes `<<bfd.h>>', IOSTREAM has been declared as a "char *",
.     and MTIME as a "long".  Their correct types, to which they
.     are cast when used, are "FILE *" and "time_t".    The iostream
.     is the result of an fopen on the filename.  However, if the
.     BFD_IN_MEMORY flag is set, then iostream is actually a pointer
.     to a bfd_in_memory struct.  *}
.  PTR iostream;
.
.  {* Is the file descriptor being cached?  That is, can it be closed as
.     needed, and re-opened when accessed later?  *}
.  bfd_boolean cacheable;
.
.  {* Marks whether there was a default target specified when the
.     BFD was opened. This is used to select which matching algorithm
.     to use to choose the back end.  *}
.  bfd_boolean target_defaulted;
.
.  {* The caching routines use these to maintain a
.     least-recently-used list of BFDs.  *}
.  struct bfd *lru_prev, *lru_next;
.
.  {* When a file is closed by the caching routines, BFD retains
.     state information on the file here...  *}
.  ufile_ptr where;
.
.  {* ... and here: (``once'' means at least once).  *}
.  bfd_boolean opened_once;
.
.  {* Set if we have a locally maintained mtime value, rather than
.     getting it from the file each time.  *}
.  bfd_boolean mtime_set;
.
.  {* File modified time, if mtime_set is TRUE.  *}
.  long mtime;
.
.  {* Reserved for an unimplemented file locking extension.  *}
.  int ifd;
.
.  {* The format which belongs to the BFD. (object, core, etc.)  *}
.  bfd_format format;
.
.  {* The direction with which the BFD was opened.  *}
.  enum bfd_direction
.    {
.      no_direction = 0,
.      read_direction = 1,
.      write_direction = 2,
.      both_direction = 3
.    }
.  direction;
.
.  {* Format_specific flags.  *}
.  flagword flags;
.
.  {* Currently my_archive is tested before adding origin to
.     anything. I believe that this can become always an add of
.     origin, with origin set to 0 for non archive files.  *}
.  ufile_ptr origin;
.
.  {* Remember when output has begun, to stop strange things
.     from happening.  *}
.  bfd_boolean output_has_begun;
.
.  {* A hash table for section names.  *}
.  struct bfd_hash_table section_htab;
.
.  {* Pointer to linked list of sections.  *}
.  struct sec *sections;
.
.  {* The place where we add to the section list.  *}
.  struct sec **section_tail;
.
.  {* The number of sections.  *}
.  unsigned int section_count;
.
.  {* Stuff only useful for object files:
.     The start address.  *}
.  bfd_vma start_address;
.
.  {* Used for input and output.  *}
.  unsigned int symcount;
.
.  {* Symbol table for output BFD (with symcount entries).  *}
.  struct symbol_cache_entry  **outsymbols;
.
.  {* Used for slurped dynamic symbol tables.  *}
.  unsigned int dynsymcount;
.
.  {* Pointer to structure which contains architecture information.  *}
.  const struct bfd_arch_info *arch_info;
.
.  {* Stuff only useful for archives.  *}
.  PTR arelt_data;
.  struct bfd *my_archive;      {* The containing archive BFD.  *}
.  struct bfd *next;            {* The next BFD in the archive.  *}
.  struct bfd *archive_head;    {* The first BFD in the archive.  *}
.  bfd_boolean has_armap;
.
.  {* A chain of BFD structures involved in a link.  *}
.  struct bfd *link_next;
.
.  {* A field used by _bfd_generic_link_add_archive_symbols.  This will
.     be used only for archive elements.  *}
.  int archive_pass;
.
.  {* Used by the back end to hold private data.  *}
.  union
.    {
.      struct aout_data_struct *aout_data;
.      struct artdata *aout_ar_data;
.      struct _oasys_data *oasys_obj_data;
.      struct _oasys_ar_data *oasys_ar_data;
.      struct coff_tdata *coff_obj_data;
.      struct pe_tdata *pe_obj_data;
.      struct xcoff_tdata *xcoff_obj_data;
.      struct ecoff_tdata *ecoff_obj_data;
.      struct ieee_data_struct *ieee_data;
.      struct ieee_ar_data_struct *ieee_ar_data;
.      struct srec_data_struct *srec_data;
.      struct ihex_data_struct *ihex_data;
.      struct tekhex_data_struct *tekhex_data;
.      struct elf_obj_tdata *elf_obj_data;
.      struct nlm_obj_tdata *nlm_obj_data;
.      struct bout_data_struct *bout_data;
.      struct mmo_data_struct *mmo_data;
.      struct sun_core_struct *sun_core_data;
.      struct sco5_core_struct *sco5_core_data;
.      struct trad_core_struct *trad_core_data;
.      struct som_data_struct *som_data;
.      struct hpux_core_struct *hpux_core_data;
.      struct hppabsd_core_struct *hppabsd_core_data;
.      struct sgi_core_struct *sgi_core_data;
.      struct lynx_core_struct *lynx_core_data;
.      struct osf_core_struct *osf_core_data;
.      struct cisco_core_struct *cisco_core_data;
.      struct versados_data_struct *versados_data;
.      struct netbsd_core_struct *netbsd_core_data;
.      struct mach_o_data_struct *mach_o_data;
.      struct mach_o_fat_data_struct *mach_o_fat_data;
.      struct bfd_pef_data_struct *pef_data;
.      struct bfd_pef_xlib_data_struct *pef_xlib_data;
.      struct bfd_sym_data_struct *sym_data;
.      PTR any;
.    }
.  tdata;
.
.  {* Used by the application to hold private data.  *}
.  PTR usrdata;
.
.  {* Where all the allocated stuff under this BFD goes.  This is a
.     struct objalloc *, but we use PTR to avoid requiring the inclusion of
.     objalloc.h.  *}
.  PTR memory;
.};
.
*/

#include "bfd.h"
#include "bfdver.h"
#include "sysdep.h"

#ifdef ANSI_PROTOTYPES
#include <stdarg.h>
#else
#include <varargs.h>
#endif

#include "libiberty.h"
#include "safe-ctype.h"
#include "bfdlink.h"
#include "libbfd.h"
#include "coff/internal.h"
#include "coff/sym.h"
#include "libcoff.h"
#include "libecoff.h"
#undef obj_symbols
#include "elf-bfd.h"
\f
/* provide storage for subsystem, stack and heap data which may have been
   passed in on the command line.  Ld puts this data into a bfd_link_info
   struct which ultimately gets passed in to the bfd.  When it arrives, copy
   it to the following struct so that the data will be available in coffcode.h
   where it is needed.  The typedef's used are defined in bfd.h */
\f
/*
SECTION
        Error reporting

        Most BFD functions return nonzero on success (check their
        individual documentation for precise semantics).  On an error,
        they call <<bfd_set_error>> to set an error condition that callers
        can check by calling <<bfd_get_error>>.
        If that returns <<bfd_error_system_call>>, then check
        <<errno>>.

        The easiest way to report a BFD error to the user is to
        use <<bfd_perror>>.

SUBSECTION
        Type <<bfd_error_type>>

        The values returned by <<bfd_get_error>> are defined by the
        enumerated type <<bfd_error_type>>.

CODE_FRAGMENT
.
.typedef enum bfd_error
.{
.  bfd_error_no_error = 0,
.  bfd_error_system_call,
.  bfd_error_invalid_target,
.  bfd_error_wrong_format,
.  bfd_error_wrong_object_format,
.  bfd_error_invalid_operation,
.  bfd_error_no_memory,
.  bfd_error_no_symbols,
.  bfd_error_no_armap,
.  bfd_error_no_more_archived_files,
.  bfd_error_malformed_archive,
.  bfd_error_file_not_recognized,
.  bfd_error_file_ambiguously_recognized,
.  bfd_error_no_contents,
.  bfd_error_nonrepresentable_section,
.  bfd_error_no_debug_section,
.  bfd_error_bad_value,
.  bfd_error_file_truncated,
.  bfd_error_file_too_big,
.  bfd_error_invalid_error_code
.}
.bfd_error_type;
.
*/

static bfd_error_type bfd_error = bfd_error_no_error;

const char *const bfd_errmsgs[] =
{
  N_("No error"),
  N_("System call error"),
  N_("Invalid bfd target"),
  N_("File in wrong format"),
  N_("Archive object file in wrong format"),
  N_("Invalid operation"),
  N_("Memory exhausted"),
  N_("No symbols"),
  N_("Archive has no index; run ranlib to add one"),
  N_("No more archived files"),
  N_("Malformed archive"),
  N_("File format not recognized"),
  N_("File format is ambiguous"),
  N_("Section has no contents"),
  N_("Nonrepresentable section on output"),
  N_("Symbol needs debug section which does not exist"),
  N_("Bad value"),
  N_("File truncated"),
  N_("File too big"),
  N_("#<Invalid error code>")
};

/*
FUNCTION
        bfd_get_error

SYNOPSIS
        bfd_error_type bfd_get_error (void);

DESCRIPTION
        Return the current BFD error condition.
*/

bfd_error_type
bfd_get_error ()
{
  return bfd_error;
}

/*
FUNCTION
        bfd_set_error

SYNOPSIS
        void bfd_set_error (bfd_error_type error_tag);

DESCRIPTION
        Set the BFD error condition to be @var{error_tag}.
*/

void
bfd_set_error (error_tag)
     bfd_error_type error_tag;
{
  bfd_error = error_tag;
}

/*
FUNCTION
        bfd_errmsg

SYNOPSIS
        const char *bfd_errmsg (bfd_error_type error_tag);

DESCRIPTION
        Return a string describing the error @var{error_tag}, or
        the system error if @var{error_tag} is <<bfd_error_system_call>>.
*/

const char *
bfd_errmsg (error_tag)
     bfd_error_type error_tag;
{
#ifndef errno
  extern int errno;
#endif
  if (error_tag == bfd_error_system_call)
    return xstrerror (errno);

  if ((((int) error_tag < (int) bfd_error_no_error) ||
       ((int) error_tag > (int) bfd_error_invalid_error_code)))
    error_tag = bfd_error_invalid_error_code;/* sanity check */

  return _(bfd_errmsgs [(int)error_tag]);
}

/*
FUNCTION
        bfd_perror

SYNOPSIS
        void bfd_perror (const char *message);

DESCRIPTION
        Print to the standard error stream a string describing the
        last BFD error that occurred, or the last system error if
        the last BFD error was a system call failure.  If @var{message}
        is non-NULL and non-empty, the error string printed is preceded
        by @var{message}, a colon, and a space.  It is followed by a newline.
*/

void
bfd_perror (message)
     const char *message;
{
  if (bfd_get_error () == bfd_error_system_call)
    /* Must be a system error then.  */
    perror ((char *)message);
  else
    {
      if (message == NULL || *message == '\0')
        fprintf (stderr, "%s\n", bfd_errmsg (bfd_get_error ()));
      else
        fprintf (stderr, "%s: %s\n", message, bfd_errmsg (bfd_get_error ()));
    }
}

/*
SUBSECTION
        BFD error handler

        Some BFD functions want to print messages describing the
        problem.  They call a BFD error handler function.  This
        function may be overriden by the program.

        The BFD error handler acts like printf.

CODE_FRAGMENT
.
.typedef void (*bfd_error_handler_type) PARAMS ((const char *, ...));
.
*/

/* The program name used when printing BFD error messages.  */

static const char *_bfd_error_program_name;

/* This is the default routine to handle BFD error messages.  */

static void _bfd_default_error_handler PARAMS ((const char *s, ...));

static void
_bfd_default_error_handler VPARAMS ((const char *s, ...))
{
  if (_bfd_error_program_name != NULL)
    fprintf (stderr, "%s: ", _bfd_error_program_name);
  else
    fprintf (stderr, "BFD: ");

  VA_OPEN (p, s);
  VA_FIXEDARG (p, const char *, s);
  vfprintf (stderr, s, p);
  VA_CLOSE (p);

  fprintf (stderr, "\n");
}

/* This is a function pointer to the routine which should handle BFD
   error messages.  It is called when a BFD routine encounters an
   error for which it wants to print a message.  Going through a
   function pointer permits a program linked against BFD to intercept
   the messages and deal with them itself.  */

bfd_error_handler_type _bfd_error_handler = _bfd_default_error_handler;

/*
FUNCTION
        bfd_set_error_handler

SYNOPSIS
        bfd_error_handler_type bfd_set_error_handler (bfd_error_handler_type);

DESCRIPTION
        Set the BFD error handler function.  Returns the previous
        function.
*/

bfd_error_handler_type
bfd_set_error_handler (pnew)
     bfd_error_handler_type pnew;
{
  bfd_error_handler_type pold;

  pold = _bfd_error_handler;
  _bfd_error_handler = pnew;
  return pold;
}

/*
FUNCTION
        bfd_set_error_program_name

SYNOPSIS
        void bfd_set_error_program_name (const char *);

DESCRIPTION
        Set the program name to use when printing a BFD error.  This
        is printed before the error message followed by a colon and
        space.  The string must not be changed after it is passed to
        this function.
*/

void
bfd_set_error_program_name (name)
     const char *name;
{
  _bfd_error_program_name = name;
}

/*
FUNCTION
        bfd_get_error_handler

SYNOPSIS
        bfd_error_handler_type bfd_get_error_handler (void);

DESCRIPTION
        Return the BFD error handler function.
*/

bfd_error_handler_type
bfd_get_error_handler ()
{
  return _bfd_error_handler;
}

/*
FUNCTION
        bfd_archive_filename

SYNOPSIS
        const char *bfd_archive_filename (bfd *);

DESCRIPTION
        For a BFD that is a component of an archive, returns a string
        with both the archive name and file name.  For other BFDs, just
        returns the file name.
*/

const char *
bfd_archive_filename (abfd)
     bfd *abfd;
{
  if (abfd->my_archive)
    {
      static size_t curr = 0;
      static char *buf;
      size_t needed;

      needed = (strlen (bfd_get_filename (abfd->my_archive))
                + strlen (bfd_get_filename (abfd)) + 3);
      if (needed > curr)
        {
          if (curr)
            free (buf);
          curr = needed + (needed >> 1);
          buf = bfd_malloc ((bfd_size_type) curr);
          /* If we can't malloc, fail safe by returning just the file
             name. This function is only used when building error
             messages.  */
          if (!buf)
            {
              curr = 0;
              return bfd_get_filename (abfd);
            }
        }
      sprintf (buf, "%s(%s)", bfd_get_filename (abfd->my_archive),
               bfd_get_filename (abfd));
      return buf;
    }
  else
    return bfd_get_filename (abfd);
}
\f
/*
SECTION
        Symbols
*/

/*
FUNCTION
        bfd_get_reloc_upper_bound

SYNOPSIS
        long bfd_get_reloc_upper_bound (bfd *abfd, asection *sect);

DESCRIPTION
        Return the number of bytes required to store the
        relocation information associated with section @var{sect}
        attached to bfd @var{abfd}.  If an error occurs, return -1.

*/

long
bfd_get_reloc_upper_bound (abfd, asect)
     bfd *abfd;
     sec_ptr asect;
{
  if (abfd->format != bfd_object)
    {
      bfd_set_error (bfd_error_invalid_operation);
      return -1;
    }

  return BFD_SEND (abfd, _get_reloc_upper_bound, (abfd, asect));
}

/*
FUNCTION
        bfd_canonicalize_reloc

SYNOPSIS
        long bfd_canonicalize_reloc
                (bfd *abfd,
                asection *sec,
                arelent **loc,
                asymbol **syms);

DESCRIPTION
        Call the back end associated with the open BFD
        @var{abfd} and translate the external form of the relocation
        information attached to @var{sec} into the internal canonical
        form.  Place the table into memory at @var{loc}, which has
        been preallocated, usually by a call to
        <<bfd_get_reloc_upper_bound>>.  Returns the number of relocs, or
        -1 on error.

        The @var{syms} table is also needed for horrible internal magic
        reasons.

*/
long
bfd_canonicalize_reloc (abfd, asect, location, symbols)
     bfd *abfd;
     sec_ptr asect;
     arelent **location;
     asymbol **symbols;
{
  if (abfd->format != bfd_object)
    {
      bfd_set_error (bfd_error_invalid_operation);
      return -1;
    }

  return BFD_SEND (abfd, _bfd_canonicalize_reloc,
                   (abfd, asect, location, symbols));
}

/*
FUNCTION
        bfd_set_reloc

SYNOPSIS
        void bfd_set_reloc
          (bfd *abfd, asection *sec, arelent **rel, unsigned int count);

DESCRIPTION
        Set the relocation pointer and count within
        section @var{sec} to the values @var{rel} and @var{count}.
        The argument @var{abfd} is ignored.

*/

void
bfd_set_reloc (ignore_abfd, asect, location, count)
     bfd *ignore_abfd ATTRIBUTE_UNUSED;
     sec_ptr asect;
     arelent **location;
     unsigned int count;
{
  asect->orelocation = location;
  asect->reloc_count = count;
}

/*
FUNCTION
        bfd_set_file_flags

SYNOPSIS
        bfd_boolean bfd_set_file_flags (bfd *abfd, flagword flags);

DESCRIPTION
        Set the flag word in the BFD @var{abfd} to the value @var{flags}.

        Possible errors are:
        o <<bfd_error_wrong_format>> - The target bfd was not of object format.
        o <<bfd_error_invalid_operation>> - The target bfd was open for reading.
        o <<bfd_error_invalid_operation>> -
        The flag word contained a bit which was not applicable to the
        type of file.  E.g., an attempt was made to set the <<D_PAGED>> bit
        on a BFD format which does not support demand paging.

*/

bfd_boolean
bfd_set_file_flags (abfd, flags)
     bfd *abfd;
     flagword flags;
{
  if (abfd->format != bfd_object)
    {
      bfd_set_error (bfd_error_wrong_format);
      return FALSE;
    }

  if (bfd_read_p (abfd))
    {
      bfd_set_error (bfd_error_invalid_operation);
      return FALSE;
    }

  bfd_get_file_flags (abfd) = flags;
  if ((flags & bfd_applicable_file_flags (abfd)) != flags)
    {
      bfd_set_error (bfd_error_invalid_operation);
      return FALSE;
    }

  return TRUE;
}

void
bfd_assert (file, line)
     const char *file;
     int line;
{
  (*_bfd_error_handler) (_("BFD %s assertion fail %s:%d"),
                         BFD_VERSION_STRING, file, line);
}

/* A more or less friendly abort message.  In libbfd.h abort is
   defined to call this function.  */

#ifndef EXIT_FAILURE
#define EXIT_FAILURE 1
#endif

void
_bfd_abort (file, line, fn)
     const char *file;
     int line;
     const char *fn;
{
  if (fn != NULL)
    (*_bfd_error_handler)
      (_("BFD %s internal error, aborting at %s line %d in %s\n"),
       BFD_VERSION_STRING, file, line, fn);
  else
    (*_bfd_error_handler)
      (_("BFD %s internal error, aborting at %s line %d\n"),
       BFD_VERSION_STRING, file, line);
  (*_bfd_error_handler) (_("Please report this bug.\n"));
  xexit (EXIT_FAILURE);
}

/*
FUNCTION
        bfd_get_arch_size

SYNOPSIS
        int bfd_get_arch_size (bfd *abfd);

DESCRIPTION
        Returns the architecture address size, in bits, as determined
        by the object file's format.  For ELF, this information is
        included in the header.

RETURNS
        Returns the arch size in bits if known, <<-1>> otherwise.
*/

int
bfd_get_arch_size (abfd)
     bfd *abfd;
{
  if (abfd->xvec->flavour == bfd_target_elf_flavour)
    return (get_elf_backend_data (abfd))->s->arch_size;

  return -1;
}

/*
FUNCTION
        bfd_get_sign_extend_vma

SYNOPSIS
        int bfd_get_sign_extend_vma (bfd *abfd);

DESCRIPTION
        Indicates if the target architecture "naturally" sign extends
        an address.  Some architectures implicitly sign extend address
        values when they are converted to types larger than the size
        of an address.  For instance, bfd_get_start_address() will
        return an address sign extended to fill a bfd_vma when this is
        the case.

RETURNS
        Returns <<1>> if the target architecture is known to sign
        extend addresses, <<0>> if the target architecture is known to
        not sign extend addresses, and <<-1>> otherwise.
*/

int
bfd_get_sign_extend_vma (abfd)
     bfd *abfd;
{
  char *name;

  if (bfd_get_flavour (abfd) == bfd_target_elf_flavour)
    return (get_elf_backend_data (abfd)->sign_extend_vma);

  name = bfd_get_target (abfd);

  /* Return a proper value for DJGPP COFF (an x86 COFF variant).
     This function is required for DWARF2 support, but there is
     no place to store this information in the COFF back end.
     Should enough other COFF targets add support for DWARF2,
     a place will have to be found.  Until then, this hack will do.  */
  if (strncmp (name, "coff-go32", sizeof ("coff-go32") - 1) == 0)
    return 1;

  bfd_set_error (bfd_error_wrong_format);
  return -1;
}

/*
FUNCTION
        bfd_set_start_address

SYNOPSIS
        bfd_boolean bfd_set_start_address (bfd *abfd, bfd_vma vma);

DESCRIPTION
        Make @var{vma} the entry point of output BFD @var{abfd}.

RETURNS
        Returns <<TRUE>> on success, <<FALSE>> otherwise.
*/

bfd_boolean
bfd_set_start_address (abfd, vma)
     bfd *abfd;
     bfd_vma vma;
{
  abfd->start_address = vma;
  return TRUE;
}

/*
FUNCTION
        bfd_get_gp_size

SYNOPSIS
        unsigned int bfd_get_gp_size (bfd *abfd);

DESCRIPTION
        Return the maximum size of objects to be optimized using the GP
        register under MIPS ECOFF.  This is typically set by the <<-G>>
        argument to the compiler, assembler or linker.
*/

unsigned int
bfd_get_gp_size (abfd)
     bfd *abfd;
{
  if (abfd->format == bfd_object)
    {
      if (abfd->xvec->flavour == bfd_target_ecoff_flavour)
        return ecoff_data (abfd)->gp_size;
      else if (abfd->xvec->flavour == bfd_target_elf_flavour)
        return elf_gp_size (abfd);
    }
  return 0;
}

/*
FUNCTION
        bfd_set_gp_size

SYNOPSIS
        void bfd_set_gp_size (bfd *abfd, unsigned int i);

DESCRIPTION
        Set the maximum size of objects to be optimized using the GP
        register under ECOFF or MIPS ELF.  This is typically set by
        the <<-G>> argument to the compiler, assembler or linker.
*/

void
bfd_set_gp_size (abfd, i)
     bfd *abfd;
     unsigned int i;
{
  /* Don't try to set GP size on an archive or core file!  */
  if (abfd->format != bfd_object)
    return;

  if (abfd->xvec->flavour == bfd_target_ecoff_flavour)
    ecoff_data (abfd)->gp_size = i;
  else if (abfd->xvec->flavour == bfd_target_elf_flavour)
    elf_gp_size (abfd) = i;
}

/* Get the GP value.  This is an internal function used by some of the
   relocation special_function routines on targets which support a GP
   register.  */

bfd_vma
_bfd_get_gp_value (abfd)
     bfd *abfd;
{
  if (abfd->format != bfd_object)
    return 0;

  if (abfd->xvec->flavour == bfd_target_ecoff_flavour)
    return ecoff_data (abfd)->gp;
  else if (abfd->xvec->flavour == bfd_target_elf_flavour)
    return elf_gp (abfd);

  return 0;
}

/* Set the GP value.  */

void
_bfd_set_gp_value (abfd, v)
     bfd *abfd;
     bfd_vma v;
{
  if (abfd->format != bfd_object)
    return;

  if (abfd->xvec->flavour == bfd_target_ecoff_flavour)
    ecoff_data (abfd)->gp = v;
  else if (abfd->xvec->flavour == bfd_target_elf_flavour)
    elf_gp (abfd) = v;
}

/*
FUNCTION
        bfd_scan_vma

SYNOPSIS
        bfd_vma bfd_scan_vma (const char *string, const char **end, int base);

DESCRIPTION
        Convert, like <<strtoul>>, a numerical expression
        @var{string} into a <<bfd_vma>> integer, and return that integer.
        (Though without as many bells and whistles as <<strtoul>>.)
        The expression is assumed to be unsigned (i.e., positive).
        If given a @var{base}, it is used as the base for conversion.
        A base of 0 causes the function to interpret the string
        in hex if a leading "0x" or "0X" is found, otherwise
        in octal if a leading zero is found, otherwise in decimal.

        If the value would overflow, the maximum <<bfd_vma>> value is
        returned.
*/

bfd_vma
bfd_scan_vma (string, end, base)
     const char *string;
     const char **end;
     int base;
{
  bfd_vma value;
  bfd_vma cutoff;
  unsigned int cutlim;
  int overflow;

  /* Let the host do it if possible.  */
  if (sizeof (bfd_vma) <= sizeof (unsigned long))
    return (bfd_vma) strtoul (string, (char **) end, base);

  if (base == 0)
    {
      if (string[0] == '0')
        {
          if ((string[1] == 'x') || (string[1] == 'X'))
            base = 16;
          else
            base = 8;
        }
    }

  if ((base < 2) || (base > 36))
    base = 10;

  if (base == 16
      && string[0] == '0'
      && (string[1] == 'x' || string[1] == 'X')
      && ISXDIGIT (string[2]))
    {
      string += 2;
    }

  cutoff = (~ (bfd_vma) 0) / (bfd_vma) base;
  cutlim = (~ (bfd_vma) 0) % (bfd_vma) base;
  value = 0;
  overflow = 0;
  while (1)
    {
      unsigned int digit;

      digit = *string;
      if (ISDIGIT (digit))
        digit = digit - '0';
      else if (ISALPHA (digit))
        digit = TOUPPER (digit) - 'A' + 10;
      else
        break;
      if (digit >= (unsigned int) base)
        break;
      if (value > cutoff || (value == cutoff && digit > cutlim))
        overflow = 1;
      value = value * base + digit;
      ++string;
    }

  if (overflow)
    value = ~ (bfd_vma) 0;

  if (end != NULL)
    *end = string;

  return value;
}

/*
FUNCTION
        bfd_copy_private_bfd_data

SYNOPSIS
        bfd_boolean bfd_copy_private_bfd_data (bfd *ibfd, bfd *obfd);

DESCRIPTION
        Copy private BFD information from the BFD @var{ibfd} to the
        the BFD @var{obfd}.  Return <<TRUE>> on success, <<FALSE>> on error.
        Possible error returns are:

        o <<bfd_error_no_memory>> -
        Not enough memory exists to create private data for @var{obfd}.

.#define bfd_copy_private_bfd_data(ibfd, obfd) \
.     BFD_SEND (obfd, _bfd_copy_private_bfd_data, \
.               (ibfd, obfd))

*/

/*
FUNCTION
        bfd_merge_private_bfd_data

SYNOPSIS
        bfd_boolean bfd_merge_private_bfd_data (bfd *ibfd, bfd *obfd);

DESCRIPTION
        Merge private BFD information from the BFD @var{ibfd} to the
        the output file BFD @var{obfd} when linking.  Return <<TRUE>>
        on success, <<FALSE>> on error.  Possible error returns are:

        o <<bfd_error_no_memory>> -
        Not enough memory exists to create private data for @var{obfd}.

.#define bfd_merge_private_bfd_data(ibfd, obfd) \
.     BFD_SEND (obfd, _bfd_merge_private_bfd_data, \
.               (ibfd, obfd))

*/

/*
FUNCTION
        bfd_set_private_flags

SYNOPSIS
        bfd_boolean bfd_set_private_flags (bfd *abfd, flagword flags);

DESCRIPTION
        Set private BFD flag information in the BFD @var{abfd}.
        Return <<TRUE>> on success, <<FALSE>> on error.  Possible error
        returns are:

        o <<bfd_error_no_memory>> -
        Not enough memory exists to create private data for @var{obfd}.

.#define bfd_set_private_flags(abfd, flags) \
.     BFD_SEND (abfd, _bfd_set_private_flags, (abfd, flags))

*/

/*
FUNCTION
        Other functions

DESCRIPTION
        The following functions exist but have not yet been documented.

.#define bfd_sizeof_headers(abfd, reloc) \
.       BFD_SEND (abfd, _bfd_sizeof_headers, (abfd, reloc))
.
.#define bfd_find_nearest_line(abfd, sec, syms, off, file, func, line) \
.       BFD_SEND (abfd, _bfd_find_nearest_line, \
.                 (abfd, sec, syms, off, file, func, line))
.
.#define bfd_debug_info_start(abfd) \
.       BFD_SEND (abfd, _bfd_debug_info_start, (abfd))
.
.#define bfd_debug_info_end(abfd) \
.       BFD_SEND (abfd, _bfd_debug_info_end, (abfd))
.
.#define bfd_debug_info_accumulate(abfd, section) \
.       BFD_SEND (abfd, _bfd_debug_info_accumulate, (abfd, section))
.
.#define bfd_stat_arch_elt(abfd, stat) \
.       BFD_SEND (abfd, _bfd_stat_arch_elt,(abfd, stat))
.
.#define bfd_update_armap_timestamp(abfd) \
.       BFD_SEND (abfd, _bfd_update_armap_timestamp, (abfd))
.
.#define bfd_set_arch_mach(abfd, arch, mach)\
.       BFD_SEND ( abfd, _bfd_set_arch_mach, (abfd, arch, mach))
.
.#define bfd_relax_section(abfd, section, link_info, again) \
.       BFD_SEND (abfd, _bfd_relax_section, (abfd, section, link_info, again))
.
.#define bfd_gc_sections(abfd, link_info) \
.       BFD_SEND (abfd, _bfd_gc_sections, (abfd, link_info))
.
.#define bfd_merge_sections(abfd, link_info) \
.       BFD_SEND (abfd, _bfd_merge_sections, (abfd, link_info))
.
.#define bfd_discard_group(abfd, sec) \
.       BFD_SEND (abfd, _bfd_discard_group, (abfd, sec))
.
.#define bfd_link_hash_table_create(abfd) \
.       BFD_SEND (abfd, _bfd_link_hash_table_create, (abfd))
.
.#define bfd_link_hash_table_free(abfd, hash) \
.       BFD_SEND (abfd, _bfd_link_hash_table_free, (hash))
.
.#define bfd_link_add_symbols(abfd, info) \
.       BFD_SEND (abfd, _bfd_link_add_symbols, (abfd, info))
.
.#define bfd_link_just_syms(sec, info) \
.       BFD_SEND (abfd, _bfd_link_just_syms, (sec, info))
.
.#define bfd_final_link(abfd, info) \
.       BFD_SEND (abfd, _bfd_final_link, (abfd, info))
.
.#define bfd_free_cached_info(abfd) \
.       BFD_SEND (abfd, _bfd_free_cached_info, (abfd))
.
.#define bfd_get_dynamic_symtab_upper_bound(abfd) \
.       BFD_SEND (abfd, _bfd_get_dynamic_symtab_upper_bound, (abfd))
.
.#define bfd_print_private_bfd_data(abfd, file)\
.       BFD_SEND (abfd, _bfd_print_private_bfd_data, (abfd, file))
.
.#define bfd_canonicalize_dynamic_symtab(abfd, asymbols) \
.       BFD_SEND (abfd, _bfd_canonicalize_dynamic_symtab, (abfd, asymbols))
.
.#define bfd_get_dynamic_reloc_upper_bound(abfd) \
.       BFD_SEND (abfd, _bfd_get_dynamic_reloc_upper_bound, (abfd))
.
.#define bfd_canonicalize_dynamic_reloc(abfd, arels, asyms) \
.       BFD_SEND (abfd, _bfd_canonicalize_dynamic_reloc, (abfd, arels, asyms))
.
.extern bfd_byte *bfd_get_relocated_section_contents
.       PARAMS ((bfd *, struct bfd_link_info *,
.                 struct bfd_link_order *, bfd_byte *,
.                 bfd_boolean, asymbol **));
.

*/

bfd_byte *
bfd_get_relocated_section_contents (abfd, link_info, link_order, data,
                                    relocateable, symbols)
     bfd *abfd;
     struct bfd_link_info *link_info;
     struct bfd_link_order *link_order;
     bfd_byte *data;
     bfd_boolean relocateable;
     asymbol **symbols;
{
  bfd *abfd2;
  bfd_byte *(*fn) PARAMS ((bfd *, struct bfd_link_info *,
                           struct bfd_link_order *, bfd_byte *, bfd_boolean,
                           asymbol **));

  if (link_order->type == bfd_indirect_link_order)
    {
      abfd2 = link_order->u.indirect.section->owner;
      if (abfd2 == NULL)
        abfd2 = abfd;
    }
  else
    abfd2 = abfd;

  fn = abfd2->xvec->_bfd_get_relocated_section_contents;

  return (*fn) (abfd, link_info, link_order, data, relocateable, symbols);
}

/* Record information about an ELF program header.  */

bfd_boolean
bfd_record_phdr (abfd, type, flags_valid, flags, at_valid, at,
                 includes_filehdr, includes_phdrs, count, secs)
     bfd *abfd;
     unsigned long type;
     bfd_boolean flags_valid;
     flagword flags;
     bfd_boolean at_valid;
     bfd_vma at;
     bfd_boolean includes_filehdr;
     bfd_boolean includes_phdrs;
     unsigned int count;
     asection **secs;
{
  struct elf_segment_map *m, **pm;
  bfd_size_type amt;

  if (bfd_get_flavour (abfd) != bfd_target_elf_flavour)
    return TRUE;

  amt = sizeof (struct elf_segment_map);
  amt += ((bfd_size_type) count - 1) * sizeof (asection *);
  m = (struct elf_segment_map *) bfd_alloc (abfd, amt);
  if (m == NULL)
    return FALSE;

  m->next = NULL;
  m->p_type = type;
  m->p_flags = flags;
  m->p_paddr = at;
  m->p_flags_valid = (unsigned int) flags_valid;
  m->p_paddr_valid = (unsigned int) at_valid;
  m->includes_filehdr = (unsigned int) includes_filehdr;
  m->includes_phdrs = (unsigned int) includes_phdrs;
  m->count = count;
  if (count > 0)
    memcpy (m->sections, secs, count * sizeof (asection *));

  for (pm = &elf_tdata (abfd)->segment_map; *pm != NULL; pm = &(*pm)->next)
    ;
  *pm = m;

  return TRUE;
}

void
bfd_sprintf_vma (abfd, buf, value)
     bfd *abfd;
     char *buf;
     bfd_vma value;
{
  if (bfd_get_flavour (abfd) == bfd_target_elf_flavour)
    get_elf_backend_data (abfd)->elf_backend_sprintf_vma (abfd, buf, value);
  else
    sprintf_vma (buf, value);
}

void
bfd_fprintf_vma (abfd, stream, value)
     bfd *abfd;
     PTR stream;
     bfd_vma value;
{
  if (bfd_get_flavour (abfd) == bfd_target_elf_flavour)
    get_elf_backend_data (abfd)->elf_backend_fprintf_vma (abfd, stream, value);
  else
    fprintf_vma ((FILE *) stream, value);
}

/*
FUNCTION
        bfd_alt_mach_code

SYNOPSIS
        bfd_boolean bfd_alt_mach_code (bfd *abfd, int alternative);

DESCRIPTION

        When more than one machine code number is available for the
        same machine type, this function can be used to switch between
        the preferred one (alternative == 0) and any others.  Currently,
        only ELF supports this feature, with up to two alternate
        machine codes.
*/

bfd_boolean
bfd_alt_mach_code (abfd, alternative)
     bfd *abfd;
     int alternative;
{
  if (bfd_get_flavour (abfd) == bfd_target_elf_flavour)
    {
      int code;

      switch (alternative)
        {
        case 0:
          code = get_elf_backend_data (abfd)->elf_machine_code;
          break;

        case 1:
          code = get_elf_backend_data (abfd)->elf_machine_alt1;
          if (code == 0)
            return FALSE;
          break;

        case 2:
          code = get_elf_backend_data (abfd)->elf_machine_alt2;
          if (code == 0)
            return FALSE;
          break;

        default:
          return FALSE;
        }

      elf_elfheader (abfd)->e_machine = code;

      return TRUE;
    }

  return FALSE;
}

/*
CODE_FRAGMENT

.struct bfd_preserve
.{
.  PTR marker;
.  PTR tdata;
.  flagword flags;
.  const struct bfd_arch_info *arch_info;
.  struct sec *sections;
.  struct sec **section_tail;
.  unsigned int section_count;
.  struct bfd_hash_table section_htab;
.};
.
*/

/*
FUNCTION
        bfd_preserve_save

SYNOPSIS
        bfd_boolean bfd_preserve_save (bfd *, struct bfd_preserve *);

DESCRIPTION
        When testing an object for compatibility with a particular
        target back-end, the back-end object_p function needs to set
        up certain fields in the bfd on successfully recognizing the
        object.  This typically happens in a piecemeal fashion, with
        failures possible at many points.  On failure, the bfd is
        supposed to be restored to its initial state, which is
        virtually impossible.  However, restoring a subset of the bfd
        state works in practice.  This function stores the subset and
        reinitializes the bfd.

*/

bfd_boolean
bfd_preserve_save (abfd, preserve)
     bfd *abfd;
     struct bfd_preserve *preserve;
{
  preserve->tdata = abfd->tdata.any;
  preserve->arch_info = abfd->arch_info;
  preserve->flags = abfd->flags;
  preserve->sections = abfd->sections;
  preserve->section_tail = abfd->section_tail;
  preserve->section_count = abfd->section_count;
  preserve->section_htab = abfd->section_htab;

  if (! bfd_hash_table_init (&abfd->section_htab, bfd_section_hash_newfunc))
    return FALSE;

  abfd->tdata.any = NULL;
  abfd->arch_info = &bfd_default_arch_struct;
  abfd->flags &= BFD_IN_MEMORY;
  abfd->sections = NULL;
  abfd->section_tail = &abfd->sections;
  abfd->section_count = 0;

  return TRUE;
}

/*
FUNCTION
        bfd_preserve_restore

SYNOPSIS
        void bfd_preserve_restore (bfd *, struct bfd_preserve *);

DESCRIPTION
        This function restores bfd state saved by bfd_preserve_save.
        If MARKER is non-NULL in struct bfd_preserve then that block
        and all subsequently bfd_alloc'd memory is freed.

*/

void
bfd_preserve_restore (abfd, preserve)
     bfd *abfd;
     struct bfd_preserve *preserve;
{
  bfd_hash_table_free (&abfd->section_htab);

  abfd->tdata.any = preserve->tdata;
  abfd->arch_info = preserve->arch_info;
  abfd->flags = preserve->flags;
  abfd->section_htab = preserve->section_htab;
  abfd->sections = preserve->sections;
  abfd->section_tail = preserve->section_tail;
  abfd->section_count = preserve->section_count;

  /* bfd_release frees all memory more recently bfd_alloc'd than
     its arg, as well as its arg.  */
  if (preserve->marker != NULL)
    {
      bfd_release (abfd, preserve->marker);
      preserve->marker = NULL;
    }
}

/*
FUNCTION
        bfd_preserve_finish

SYNOPSIS
        void bfd_preserve_finish (bfd *, struct bfd_preserve *);

DESCRIPTION
        This function should be called when the bfd state saved by
        bfd_preserve_save is no longer needed.  ie. when the back-end
        object_p function returns with success.

*/

void
bfd_preserve_finish (abfd, preserve)
     bfd *abfd ATTRIBUTE_UNUSED;
     struct bfd_preserve *preserve;
{
  /* It would be nice to be able to free more memory here, eg. old
     tdata, but that's not possible since these blocks are sitting
     inside bfd_alloc'd memory.  The section hash is on a separate
     objalloc.  */
  bfd_hash_table_free (&preserve->section_htab);
}