[deliverable/binutils-gdb.git] / bfd / elfcode.h

/* ELF executable support for BFD.
   Copyright 1991, 1992, 1993, 1994, 1995 Free Software Foundation, Inc.

   Written by Fred Fish @ Cygnus Support, from information published
   in "UNIX System V Release 4, Programmers Guide: ANSI C and
   Programming Support Tools".  Sufficient support for gdb.

   Rewritten by Mark Eichin @ Cygnus Support, from information
   published in "System V Application Binary Interface", chapters 4
   and 5, as well as the various "Processor Supplement" documents
   derived from it. Added support for assembler and other object file
   utilities.  Further work done by Ken Raeburn (Cygnus Support), Michael
   Meissner (Open Software Foundation), and Peter Hoogenboom (University
   of Utah) to finish and extend this.

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.  */

/* Problems and other issues to resolve.

   (1)  BFD expects there to be some fixed number of "sections" in
        the object file.  I.E. there is a "section_count" variable in the
        bfd structure which contains the number of sections.  However, ELF
        supports multiple "views" of a file.  In particular, with current
        implementations, executable files typically have two tables, a
        program header table and a section header table, both of which
        partition the executable.

        In ELF-speak, the "linking view" of the file uses the section header
        table to access "sections" within the file, and the "execution view"
        uses the program header table to access "segments" within the file.
        "Segments" typically may contain all the data from one or more
        "sections".

        Note that the section header table is optional in ELF executables,
        but it is this information that is most useful to gdb.  If the
        section header table is missing, then gdb should probably try
        to make do with the program header table.  (FIXME)

   (2)  The code in this file is compiled twice, once in 32-bit mode and
        once in 64-bit mode.  More of it should be made size-independent
        and moved into elf.c.

   (3)  ELF section symbols are handled rather sloppily now.  This should
        be cleaned up, and ELF section symbols reconciled with BFD section
        symbols.

   (4)  We need a published spec for 64-bit ELF.  We've got some stuff here
        that we're using for SPARC V9 64-bit chips, but don't assume that
        it's cast in stone.
 */

#include <string.h>             /* For strrchr and friends */
#include "bfd.h"
#include "sysdep.h"
#include "bfdlink.h"
#include "libbfd.h"
#include "elf-bfd.h"

/* Renaming structures, typedefs, macros and functions to be size-specific.  */
#define Elf_External_Ehdr       NAME(Elf,External_Ehdr)
#define Elf_External_Sym        NAME(Elf,External_Sym)
#define Elf_External_Shdr       NAME(Elf,External_Shdr)
#define Elf_External_Phdr       NAME(Elf,External_Phdr)
#define Elf_External_Rel        NAME(Elf,External_Rel)
#define Elf_External_Rela       NAME(Elf,External_Rela)
#define Elf_External_Dyn        NAME(Elf,External_Dyn)

#define elf_core_file_failing_command   NAME(bfd_elf,core_file_failing_command)
#define elf_core_file_failing_signal    NAME(bfd_elf,core_file_failing_signal)
#define elf_core_file_matches_executable_p \
  NAME(bfd_elf,core_file_matches_executable_p)
#define elf_object_p                    NAME(bfd_elf,object_p)
#define elf_core_file_p                 NAME(bfd_elf,core_file_p)
#define elf_get_symtab_upper_bound      NAME(bfd_elf,get_symtab_upper_bound)
#define elf_get_dynamic_symtab_upper_bound \
  NAME(bfd_elf,get_dynamic_symtab_upper_bound)
#define elf_swap_reloc_in               NAME(bfd_elf,swap_reloc_in)
#define elf_swap_reloca_in              NAME(bfd_elf,swap_reloca_in)
#define elf_swap_reloc_out              NAME(bfd_elf,swap_reloc_out)
#define elf_swap_reloca_out             NAME(bfd_elf,swap_reloca_out)
#define elf_swap_symbol_in              NAME(bfd_elf,swap_symbol_in)
#define elf_swap_symbol_out             NAME(bfd_elf,swap_symbol_out)
#define elf_swap_phdr_in                NAME(bfd_elf,swap_phdr_in)
#define elf_swap_phdr_out               NAME(bfd_elf,swap_phdr_out)
#define elf_swap_dyn_in                 NAME(bfd_elf,swap_dyn_in)
#define elf_swap_dyn_out                NAME(bfd_elf,swap_dyn_out)
#define elf_get_reloc_upper_bound       NAME(bfd_elf,get_reloc_upper_bound)
#define elf_canonicalize_reloc          NAME(bfd_elf,canonicalize_reloc)
#define elf_get_symtab                  NAME(bfd_elf,get_symtab)
#define elf_canonicalize_dynamic_symtab \
  NAME(bfd_elf,canonicalize_dynamic_symtab)
#define elf_make_empty_symbol           NAME(bfd_elf,make_empty_symbol)
#define elf_get_symbol_info             NAME(bfd_elf,get_symbol_info)
#define elf_get_lineno                  NAME(bfd_elf,get_lineno)
#define elf_set_arch_mach               NAME(bfd_elf,set_arch_mach)
#define elf_find_nearest_line           NAME(bfd_elf,find_nearest_line)
#define elf_sizeof_headers              NAME(bfd_elf,sizeof_headers)
#define elf_set_section_contents        NAME(bfd_elf,set_section_contents)
#define elf_no_info_to_howto            NAME(bfd_elf,no_info_to_howto)
#define elf_no_info_to_howto_rel        NAME(bfd_elf,no_info_to_howto_rel)
#define elf_find_section                NAME(bfd_elf,find_section)
#define elf_bfd_link_add_symbols        NAME(bfd_elf,bfd_link_add_symbols)
#define elf_add_dynamic_entry           NAME(bfd_elf,add_dynamic_entry)
#define elf_link_create_dynamic_sections \
  NAME(bfd_elf,link_create_dynamic_sections)
#define elf_link_record_dynamic_symbol  _bfd_elf_link_record_dynamic_symbol
#define elf_bfd_final_link              NAME(bfd_elf,bfd_final_link)

#if ARCH_SIZE == 64
#define ELF_R_INFO(X,Y) ELF64_R_INFO(X,Y)
#define ELF_R_SYM(X)    ELF64_R_SYM(X)
#define ELF_R_TYPE(X)   ELF64_R_TYPE(X)
#define ELFCLASS        ELFCLASS64
#define FILE_ALIGN      8
#define LOG_FILE_ALIGN  3
#endif
#if ARCH_SIZE == 32
#define ELF_R_INFO(X,Y) ELF32_R_INFO(X,Y)
#define ELF_R_SYM(X)    ELF32_R_SYM(X)
#define ELF_R_TYPE(X)   ELF32_R_TYPE(X)
#define ELFCLASS        ELFCLASS32
#define FILE_ALIGN      4
#define LOG_FILE_ALIGN  2
#endif

/* Forward declarations of static functions */

#define elf_stringtab_init _bfd_elf_stringtab_init

extern struct bfd_strtab_hash *_bfd_elf_stringtab_init PARAMS ((void));
#define section_from_elf_index bfd_section_from_elf_index
extern boolean bfd_section_from_phdr PARAMS ((bfd *, Elf_Internal_Phdr *,
                                              int));

 int _bfd_elf_section_from_bfd_section PARAMS ((bfd *, struct sec *));

static long elf_slurp_symbol_table PARAMS ((bfd *, asymbol **, boolean));

static boolean elf_slurp_reloc_table PARAMS ((bfd *, asection *, asymbol **));

 int _bfd_elf_symbol_from_bfd_symbol PARAMS ((bfd *,
                                             struct symbol_cache_entry **));

static void write_relocs PARAMS ((bfd *, asection *, PTR));

 boolean bfd_section_from_shdr PARAMS ((bfd *, unsigned int shindex));

#ifdef DEBUG
static void elf_debug_section PARAMS ((int, Elf_Internal_Shdr *));
static void elf_debug_file PARAMS ((Elf_Internal_Ehdr *));
static char *elf_symbol_flags PARAMS ((flagword));
#endif
\f
/* Structure swapping routines */

/* Should perhaps use put_offset, put_word, etc.  For now, the two versions
   can be handled by explicitly specifying 32 bits or "the long type".  */
#if ARCH_SIZE == 64
#define put_word        bfd_h_put_64
#define get_word        bfd_h_get_64
#endif
#if ARCH_SIZE == 32
#define put_word        bfd_h_put_32
#define get_word        bfd_h_get_32
#endif

/* Translate an ELF symbol in external format into an ELF symbol in internal
   format. */

void
elf_swap_symbol_in (abfd, src, dst)
     bfd *abfd;
     Elf_External_Sym *src;
     Elf_Internal_Sym *dst;
{
  dst->st_name = bfd_h_get_32 (abfd, (bfd_byte *) src->st_name);
  dst->st_value = get_word (abfd, (bfd_byte *) src->st_value);
  dst->st_size = get_word (abfd, (bfd_byte *) src->st_size);
  dst->st_info = bfd_h_get_8 (abfd, (bfd_byte *) src->st_info);
  dst->st_other = bfd_h_get_8 (abfd, (bfd_byte *) src->st_other);
  dst->st_shndx = bfd_h_get_16 (abfd, (bfd_byte *) src->st_shndx);
}

/* Translate an ELF symbol in internal format into an ELF symbol in external
   format. */

void
elf_swap_symbol_out (abfd, src, cdst)
     bfd *abfd;
     Elf_Internal_Sym *src;
     PTR cdst;
{
  Elf_External_Sym *dst = (Elf_External_Sym *) cdst;
  bfd_h_put_32 (abfd, src->st_name, dst->st_name);
  put_word (abfd, src->st_value, dst->st_value);
  put_word (abfd, src->st_size, dst->st_size);
  bfd_h_put_8 (abfd, src->st_info, dst->st_info);
  bfd_h_put_8 (abfd, src->st_other, dst->st_other);
  bfd_h_put_16 (abfd, src->st_shndx, dst->st_shndx);
}


/* Translate an ELF file header in external format into an ELF file header in
   internal format. */

static void
elf_swap_ehdr_in (abfd, src, dst)
     bfd *abfd;
     Elf_External_Ehdr *src;
     Elf_Internal_Ehdr *dst;
{
  memcpy (dst->e_ident, src->e_ident, EI_NIDENT);
  dst->e_type = bfd_h_get_16 (abfd, (bfd_byte *) src->e_type);
  dst->e_machine = bfd_h_get_16 (abfd, (bfd_byte *) src->e_machine);
  dst->e_version = bfd_h_get_32 (abfd, (bfd_byte *) src->e_version);
  dst->e_entry = get_word (abfd, (bfd_byte *) src->e_entry);
  dst->e_phoff = get_word (abfd, (bfd_byte *) src->e_phoff);
  dst->e_shoff = get_word (abfd, (bfd_byte *) src->e_shoff);
  dst->e_flags = bfd_h_get_32 (abfd, (bfd_byte *) src->e_flags);
  dst->e_ehsize = bfd_h_get_16 (abfd, (bfd_byte *) src->e_ehsize);
  dst->e_phentsize = bfd_h_get_16 (abfd, (bfd_byte *) src->e_phentsize);
  dst->e_phnum = bfd_h_get_16 (abfd, (bfd_byte *) src->e_phnum);
  dst->e_shentsize = bfd_h_get_16 (abfd, (bfd_byte *) src->e_shentsize);
  dst->e_shnum = bfd_h_get_16 (abfd, (bfd_byte *) src->e_shnum);
  dst->e_shstrndx = bfd_h_get_16 (abfd, (bfd_byte *) src->e_shstrndx);
}

/* Translate an ELF file header in internal format into an ELF file header in
   external format. */

static void
elf_swap_ehdr_out (abfd, src, dst)
     bfd *abfd;
     Elf_Internal_Ehdr *src;
     Elf_External_Ehdr *dst;
{
  memcpy (dst->e_ident, src->e_ident, EI_NIDENT);
  /* note that all elements of dst are *arrays of unsigned char* already... */
  bfd_h_put_16 (abfd, src->e_type, dst->e_type);
  bfd_h_put_16 (abfd, src->e_machine, dst->e_machine);
  bfd_h_put_32 (abfd, src->e_version, dst->e_version);
  put_word (abfd, src->e_entry, dst->e_entry);
  put_word (abfd, src->e_phoff, dst->e_phoff);
  put_word (abfd, src->e_shoff, dst->e_shoff);
  bfd_h_put_32 (abfd, src->e_flags, dst->e_flags);
  bfd_h_put_16 (abfd, src->e_ehsize, dst->e_ehsize);
  bfd_h_put_16 (abfd, src->e_phentsize, dst->e_phentsize);
  bfd_h_put_16 (abfd, src->e_phnum, dst->e_phnum);
  bfd_h_put_16 (abfd, src->e_shentsize, dst->e_shentsize);
  bfd_h_put_16 (abfd, src->e_shnum, dst->e_shnum);
  bfd_h_put_16 (abfd, src->e_shstrndx, dst->e_shstrndx);
}


/* Translate an ELF section header table entry in external format into an
   ELF section header table entry in internal format. */

static void
elf_swap_shdr_in (abfd, src, dst)
     bfd *abfd;
     Elf_External_Shdr *src;
     Elf_Internal_Shdr *dst;
{
  dst->sh_name = bfd_h_get_32 (abfd, (bfd_byte *) src->sh_name);
  dst->sh_type = bfd_h_get_32 (abfd, (bfd_byte *) src->sh_type);
  dst->sh_flags = get_word (abfd, (bfd_byte *) src->sh_flags);
  dst->sh_addr = get_word (abfd, (bfd_byte *) src->sh_addr);
  dst->sh_offset = get_word (abfd, (bfd_byte *) src->sh_offset);
  dst->sh_size = get_word (abfd, (bfd_byte *) src->sh_size);
  dst->sh_link = bfd_h_get_32 (abfd, (bfd_byte *) src->sh_link);
  dst->sh_info = bfd_h_get_32 (abfd, (bfd_byte *) src->sh_info);
  dst->sh_addralign = get_word (abfd, (bfd_byte *) src->sh_addralign);
  dst->sh_entsize = get_word (abfd, (bfd_byte *) src->sh_entsize);
  dst->bfd_section = NULL;
  dst->contents = NULL;
}

/* Translate an ELF section header table entry in internal format into an
   ELF section header table entry in external format. */

static void
elf_swap_shdr_out (abfd, src, dst)
     bfd *abfd;
     Elf_Internal_Shdr *src;
     Elf_External_Shdr *dst;
{
  /* note that all elements of dst are *arrays of unsigned char* already... */
  bfd_h_put_32 (abfd, src->sh_name, dst->sh_name);
  bfd_h_put_32 (abfd, src->sh_type, dst->sh_type);
  put_word (abfd, src->sh_flags, dst->sh_flags);
  put_word (abfd, src->sh_addr, dst->sh_addr);
  put_word (abfd, src->sh_offset, dst->sh_offset);
  put_word (abfd, src->sh_size, dst->sh_size);
  bfd_h_put_32 (abfd, src->sh_link, dst->sh_link);
  bfd_h_put_32 (abfd, src->sh_info, dst->sh_info);
  put_word (abfd, src->sh_addralign, dst->sh_addralign);
  put_word (abfd, src->sh_entsize, dst->sh_entsize);
}


/* Translate an ELF program header table entry in external format into an
   ELF program header table entry in internal format. */

void
elf_swap_phdr_in (abfd, src, dst)
     bfd *abfd;
     Elf_External_Phdr *src;
     Elf_Internal_Phdr *dst;
{
  dst->p_type = bfd_h_get_32 (abfd, (bfd_byte *) src->p_type);
  dst->p_flags = bfd_h_get_32 (abfd, (bfd_byte *) src->p_flags);
  dst->p_offset = get_word (abfd, (bfd_byte *) src->p_offset);
  dst->p_vaddr = get_word (abfd, (bfd_byte *) src->p_vaddr);
  dst->p_paddr = get_word (abfd, (bfd_byte *) src->p_paddr);
  dst->p_filesz = get_word (abfd, (bfd_byte *) src->p_filesz);
  dst->p_memsz = get_word (abfd, (bfd_byte *) src->p_memsz);
  dst->p_align = get_word (abfd, (bfd_byte *) src->p_align);
}

void
elf_swap_phdr_out (abfd, src, dst)
     bfd *abfd;
     Elf_Internal_Phdr *src;
     Elf_External_Phdr *dst;
{
  /* note that all elements of dst are *arrays of unsigned char* already... */
  bfd_h_put_32 (abfd, src->p_type, dst->p_type);
  put_word (abfd, src->p_offset, dst->p_offset);
  put_word (abfd, src->p_vaddr, dst->p_vaddr);
  put_word (abfd, src->p_paddr, dst->p_paddr);
  put_word (abfd, src->p_filesz, dst->p_filesz);
  put_word (abfd, src->p_memsz, dst->p_memsz);
  bfd_h_put_32 (abfd, src->p_flags, dst->p_flags);
  put_word (abfd, src->p_align, dst->p_align);
}

/* Translate an ELF reloc from external format to internal format. */
INLINE void
elf_swap_reloc_in (abfd, src, dst)
     bfd *abfd;
     Elf_External_Rel *src;
     Elf_Internal_Rel *dst;
{
  dst->r_offset = get_word (abfd, (bfd_byte *) src->r_offset);
  dst->r_info = get_word (abfd, (bfd_byte *) src->r_info);
}

INLINE void
elf_swap_reloca_in (abfd, src, dst)
     bfd *abfd;
     Elf_External_Rela *src;
     Elf_Internal_Rela *dst;
{
  dst->r_offset = get_word (abfd, (bfd_byte *) src->r_offset);
  dst->r_info = get_word (abfd, (bfd_byte *) src->r_info);
  dst->r_addend = get_word (abfd, (bfd_byte *) src->r_addend);
}

/* Translate an ELF reloc from internal format to external format. */
INLINE void
elf_swap_reloc_out (abfd, src, dst)
     bfd *abfd;
     Elf_Internal_Rel *src;
     Elf_External_Rel *dst;
{
  put_word (abfd, src->r_offset, dst->r_offset);
  put_word (abfd, src->r_info, dst->r_info);
}

INLINE void
elf_swap_reloca_out (abfd, src, dst)
     bfd *abfd;
     Elf_Internal_Rela *src;
     Elf_External_Rela *dst;
{
  put_word (abfd, src->r_offset, dst->r_offset);
  put_word (abfd, src->r_info, dst->r_info);
  put_word (abfd, src->r_addend, dst->r_addend);
}

INLINE void
elf_swap_dyn_in (abfd, src, dst)
     bfd *abfd;
     const Elf_External_Dyn *src;
     Elf_Internal_Dyn *dst;
{
  dst->d_tag = get_word (abfd, src->d_tag);
  dst->d_un.d_val = get_word (abfd, src->d_un.d_val);
}

INLINE void
elf_swap_dyn_out (abfd, src, dst)
     bfd *abfd;
     const Elf_Internal_Dyn *src;
     Elf_External_Dyn *dst;
{
  put_word (abfd, src->d_tag, dst->d_tag);
  put_word (abfd, src->d_un.d_val, dst->d_un.d_val);
}
\f
/* ELF .o/exec file reading */


/* Begin processing a given object.

   First we validate the file by reading in the ELF header and checking
   the magic number.  */

static INLINE boolean
elf_file_p (x_ehdrp)
     Elf_External_Ehdr *x_ehdrp;
{
  return ((x_ehdrp->e_ident[EI_MAG0] == ELFMAG0)
          && (x_ehdrp->e_ident[EI_MAG1] == ELFMAG1)
          && (x_ehdrp->e_ident[EI_MAG2] == ELFMAG2)
          && (x_ehdrp->e_ident[EI_MAG3] == ELFMAG3));
}

/* Check to see if the file associated with ABFD matches the target vector
   that ABFD points to.

   Note that we may be called several times with the same ABFD, but different
   target vectors, most of which will not match.  We have to avoid leaving
   any side effects in ABFD, or any data it points to (like tdata), if the
   file does not match the target vector.  */

const bfd_target *
elf_object_p (abfd)
     bfd *abfd;
{
  Elf_External_Ehdr x_ehdr;     /* Elf file header, external form */
  Elf_Internal_Ehdr *i_ehdrp;   /* Elf file header, internal form */
  Elf_External_Shdr x_shdr;     /* Section header table entry, external form */
  Elf_Internal_Shdr *i_shdrp = NULL; /* Section header table, internal form */
  unsigned int shindex;
  char *shstrtab;               /* Internal copy of section header stringtab */
  struct elf_backend_data *ebd;
  struct elf_obj_tdata *preserved_tdata = elf_tdata (abfd);
  struct elf_obj_tdata *new_tdata = NULL;

  /* Read in the ELF header in external format.  */

  if (bfd_read ((PTR) & x_ehdr, sizeof (x_ehdr), 1, abfd) != sizeof (x_ehdr))
    {
      if (bfd_get_error () != bfd_error_system_call)
        goto got_wrong_format_error;
      else
        goto got_no_match;
    }

  /* Now check to see if we have a valid ELF file, and one that BFD can
     make use of.  The magic number must match, the address size ('class')
     and byte-swapping must match our XVEC entry, and it must have a
     section header table (FIXME: See comments re sections at top of this
     file). */

  if ((elf_file_p (&x_ehdr) == false) ||
      (x_ehdr.e_ident[EI_VERSION] != EV_CURRENT) ||
      (x_ehdr.e_ident[EI_CLASS] != ELFCLASS))
    goto got_wrong_format_error;

  /* Check that file's byte order matches xvec's */
  switch (x_ehdr.e_ident[EI_DATA])
    {
    case ELFDATA2MSB:           /* Big-endian */
      if (!abfd->xvec->header_byteorder_big_p)
        goto got_wrong_format_error;
      break;
    case ELFDATA2LSB:           /* Little-endian */
      if (abfd->xvec->header_byteorder_big_p)
        goto got_wrong_format_error;
      break;
    case ELFDATANONE:           /* No data encoding specified */
    default:                    /* Unknown data encoding specified */
      goto got_wrong_format_error;
    }

  /* Allocate an instance of the elf_obj_tdata structure and hook it up to
     the tdata pointer in the bfd.  */

  new_tdata = ((struct elf_obj_tdata *)
               bfd_zalloc (abfd, sizeof (struct elf_obj_tdata)));
  if (new_tdata == NULL)
    goto got_no_match;
  elf_tdata (abfd) = new_tdata;

  /* Now that we know the byte order, swap in the rest of the header */
  i_ehdrp = elf_elfheader (abfd);
  elf_swap_ehdr_in (abfd, &x_ehdr, i_ehdrp);
#if DEBUG & 1
  elf_debug_file (i_ehdrp);
#endif

  /* If there is no section header table, we're hosed. */
  if (i_ehdrp->e_shoff == 0)
    goto got_wrong_format_error;

  /* As a simple sanity check, verify that the what BFD thinks is the
     size of each section header table entry actually matches the size
     recorded in the file. */
  if (i_ehdrp->e_shentsize != sizeof (x_shdr))
    goto got_wrong_format_error;

  ebd = get_elf_backend_data (abfd);

  /* Check that the ELF e_machine field matches what this particular
     BFD format expects.  */
  if (ebd->elf_machine_code != i_ehdrp->e_machine
      && (ebd->elf_machine_alt1 == 0 || i_ehdrp->e_machine != ebd->elf_machine_alt1)
      && (ebd->elf_machine_alt2 == 0 || i_ehdrp->e_machine != ebd->elf_machine_alt2))
    {
      const bfd_target * const *target_ptr;

      if (ebd->elf_machine_code != EM_NONE)
        goto got_wrong_format_error;

      /* This is the generic ELF target.  Let it match any ELF target
         for which we do not have a specific backend.  */
      for (target_ptr = bfd_target_vector; *target_ptr != NULL; target_ptr++)
        {
          struct elf_backend_data *back;

          if ((*target_ptr)->flavour != bfd_target_elf_flavour)
            continue;
          back = (struct elf_backend_data *) (*target_ptr)->backend_data;
          if (back->elf_machine_code == i_ehdrp->e_machine)
            {
              /* target_ptr is an ELF backend which matches this
                 object file, so reject the generic ELF target.  */
              goto got_wrong_format_error;
            }
        }
    }

  if (i_ehdrp->e_type == ET_EXEC)
    abfd->flags |= EXEC_P;
  else if (i_ehdrp->e_type == ET_DYN)
    abfd->flags |= DYNAMIC;

  if (i_ehdrp->e_phnum > 0)
    abfd->flags |= D_PAGED;

  if (! bfd_default_set_arch_mach (abfd, ebd->arch, 0))
    goto got_no_match;

  /* Remember the entry point specified in the ELF file header. */
  bfd_get_start_address (abfd) = i_ehdrp->e_entry;

  /* Allocate space for a copy of the section header table in
     internal form, seek to the section header table in the file,
     read it in, and convert it to internal form.  */
  i_shdrp = ((Elf_Internal_Shdr *)
             bfd_alloc (abfd, sizeof (*i_shdrp) * i_ehdrp->e_shnum));
  elf_elfsections (abfd) = ((Elf_Internal_Shdr **)
                            bfd_alloc (abfd,
                                       sizeof (i_shdrp) * i_ehdrp->e_shnum));
  if (!i_shdrp || !elf_elfsections (abfd))
    goto got_no_match;
  if (bfd_seek (abfd, i_ehdrp->e_shoff, SEEK_SET) != 0)
    goto got_no_match;
  for (shindex = 0; shindex < i_ehdrp->e_shnum; shindex++)
    {
      if (bfd_read ((PTR) & x_shdr, sizeof x_shdr, 1, abfd) != sizeof (x_shdr))
        goto got_no_match;
      elf_swap_shdr_in (abfd, &x_shdr, i_shdrp + shindex);
      elf_elfsections (abfd)[shindex] = i_shdrp + shindex;
    }
  if (i_ehdrp->e_shstrndx)
    {
      if (! bfd_section_from_shdr (abfd, i_ehdrp->e_shstrndx))
        goto got_no_match;
    }

  /* Read in the program headers.  */
  if (i_ehdrp->e_phnum == 0)
    elf_tdata (abfd)->phdr = NULL;
  else
    {
      Elf_Internal_Phdr *i_phdr;
      unsigned int i;

      elf_tdata (abfd)->phdr = ((Elf_Internal_Phdr *)
                                bfd_alloc (abfd,
                                           (i_ehdrp->e_phnum
                                            * sizeof (Elf_Internal_Phdr))));
      if (elf_tdata (abfd)->phdr == NULL)
        goto got_no_match;
      if (bfd_seek (abfd, i_ehdrp->e_phoff, SEEK_SET) != 0)
        goto got_no_match;
      i_phdr = elf_tdata (abfd)->phdr;
      for (i = 0; i < i_ehdrp->e_phnum; i++, i_phdr++)
        {
          Elf_External_Phdr x_phdr;

          if (bfd_read ((PTR) &x_phdr, sizeof x_phdr, 1, abfd)
              != sizeof x_phdr)
            goto got_no_match;
          elf_swap_phdr_in (abfd, &x_phdr, i_phdr);
        }
    }

  /* Read in the string table containing the names of the sections.  We
     will need the base pointer to this table later. */
  /* We read this inline now, so that we don't have to go through
     bfd_section_from_shdr with it (since this particular strtab is
     used to find all of the ELF section names.) */

  shstrtab = bfd_elf_get_str_section (abfd, i_ehdrp->e_shstrndx);
  if (!shstrtab)
    goto got_no_match;

  /* Once all of the section headers have been read and converted, we
     can start processing them.  Note that the first section header is
     a dummy placeholder entry, so we ignore it.  */

  for (shindex = 1; shindex < i_ehdrp->e_shnum; shindex++)
    {
      if (! bfd_section_from_shdr (abfd, shindex))
        goto got_no_match;
    }

  /* Let the backend double check the format and override global
     information.  */
  if (ebd->elf_backend_object_p)
    {
      if ((*ebd->elf_backend_object_p) (abfd) == false)
        goto got_wrong_format_error;
    }

  return (abfd->xvec);

got_wrong_format_error:
  bfd_set_error (bfd_error_wrong_format);
  goto got_no_match;
got_no_match:
  if (new_tdata != NULL
      && new_tdata->elf_sect_ptr != NULL)
    bfd_release (abfd, new_tdata->elf_sect_ptr);
  if (i_shdrp != NULL)
    bfd_release (abfd, i_shdrp);
  if (new_tdata != NULL)
    bfd_release (abfd, new_tdata);
  elf_tdata (abfd) = preserved_tdata;
  return (NULL);
}
\f

/* ELF .o/exec file writing */

static void
write_relocs (abfd, sec, data)
     bfd *abfd;
     asection *sec;
     PTR data;
{
  boolean *failedp = (boolean *) data;
  Elf_Internal_Shdr *rela_hdr;
  Elf_External_Rela *outbound_relocas;
  Elf_External_Rel *outbound_relocs;
  unsigned int idx;
  int use_rela_p = get_elf_backend_data (abfd)->use_rela_p;
  asymbol *last_sym = 0;
  int last_sym_idx = 9999999;   /* should always be written before use */

  /* If we have already failed, don't do anything.  */
  if (*failedp)
    return;

  if ((sec->flags & SEC_RELOC) == 0)
    return;

  /* The linker backend writes the relocs out itself, and sets the
     reloc_count field to zero to inhibit writing them here.  Also,
     sometimes the SEC_RELOC flag gets set even when there aren't any
     relocs.  */
  if (sec->reloc_count == 0)
    return;

  rela_hdr = &elf_section_data (sec)->rel_hdr;

  rela_hdr->sh_size = rela_hdr->sh_entsize * sec->reloc_count;
  rela_hdr->contents = (PTR) bfd_alloc (abfd, rela_hdr->sh_size);
  if (rela_hdr->contents == NULL)
    {
      *failedp = true;
      return;
    }

  /* orelocation has the data, reloc_count has the count... */
  if (use_rela_p)
    {
      outbound_relocas = (Elf_External_Rela *) rela_hdr->contents;

      for (idx = 0; idx < sec->reloc_count; idx++)
        {
          Elf_Internal_Rela dst_rela;
          Elf_External_Rela *src_rela;
          arelent *ptr;
          asymbol *sym;
          int n;

          ptr = sec->orelocation[idx];
          src_rela = outbound_relocas + idx;

          /* The address of an ELF reloc is section relative for an object
             file, and absolute for an executable file or shared library.
             The address of a BFD reloc is always section relative.  */
          if ((abfd->flags & (EXEC_P | DYNAMIC)) == 0)
            dst_rela.r_offset = ptr->address;
          else
            dst_rela.r_offset = ptr->address + sec->vma;

          sym = *ptr->sym_ptr_ptr;
          if (sym == last_sym)
            n = last_sym_idx;
          else
            {
              last_sym = sym;
              last_sym_idx = n = _bfd_elf_symbol_from_bfd_symbol (abfd, &sym);
            }
          dst_rela.r_info = ELF_R_INFO (n, ptr->howto->type);

          dst_rela.r_addend = ptr->addend;
          elf_swap_reloca_out (abfd, &dst_rela, src_rela);
        }
    }
  else
    /* REL relocations */
    {
      outbound_relocs = (Elf_External_Rel *) rela_hdr->contents;

      for (idx = 0; idx < sec->reloc_count; idx++)
        {
          Elf_Internal_Rel dst_rel;
          Elf_External_Rel *src_rel;
          arelent *ptr;
          int n;
          asymbol *sym;

          ptr = sec->orelocation[idx];
          sym = *ptr->sym_ptr_ptr;
          src_rel = outbound_relocs + idx;

          /* The address of an ELF reloc is section relative for an object
             file, and absolute for an executable file or shared library.
             The address of a BFD reloc is always section relative.  */
          if ((abfd->flags & (EXEC_P | DYNAMIC)) == 0)
            dst_rel.r_offset = ptr->address;
          else
            dst_rel.r_offset = ptr->address + sec->vma;

          if (sym == last_sym)
            n = last_sym_idx;
          else
            {
              last_sym = sym;
              last_sym_idx = n = _bfd_elf_symbol_from_bfd_symbol (abfd, &sym);
            }
          dst_rel.r_info = ELF_R_INFO (n, ptr->howto->type);

          elf_swap_reloc_out (abfd, &dst_rel, src_rel);
        }
    }
}

static int
write_out_phdrs (abfd, phdr, count)
     bfd *abfd;
     Elf_Internal_Phdr *phdr;
     int count;
{
  while (count--)
    {
      Elf_External_Phdr extphdr;
      elf_swap_phdr_out (abfd, phdr, &extphdr);
      if (bfd_write (&extphdr, sizeof (Elf_External_Phdr), 1, abfd)
          != sizeof (Elf_External_Phdr))
        return -1;
      phdr++;
    }
  return 0;
}

static boolean
write_shdrs_and_ehdr (abfd)
     bfd *abfd;
{
  Elf_External_Ehdr x_ehdr;     /* Elf file header, external form */
  Elf_Internal_Ehdr *i_ehdrp;   /* Elf file header, internal form */
  Elf_External_Shdr *x_shdrp;   /* Section header table, external form */
  Elf_Internal_Shdr **i_shdrp;  /* Section header table, internal form */
  unsigned int count;

  i_ehdrp = elf_elfheader (abfd);
  i_shdrp = elf_elfsections (abfd);

  /* swap the header before spitting it out... */

#if DEBUG & 1
  elf_debug_file (i_ehdrp);
#endif
  elf_swap_ehdr_out (abfd, i_ehdrp, &x_ehdr);
  if (bfd_seek (abfd, (file_ptr) 0, SEEK_SET) != 0
      || (bfd_write ((PTR) & x_ehdr, sizeof (x_ehdr), 1, abfd)
          != sizeof (x_ehdr)))
    return false;

  /* at this point we've concocted all the ELF sections... */
  x_shdrp = (Elf_External_Shdr *)
    bfd_alloc (abfd, sizeof (*x_shdrp) * (i_ehdrp->e_shnum));
  if (!x_shdrp)
    return false;

  for (count = 0; count < i_ehdrp->e_shnum; count++)
    {
#if DEBUG & 2
      elf_debug_section (count, i_shdrp[count]);
#endif
      elf_swap_shdr_out (abfd, i_shdrp[count], x_shdrp + count);
    }
  if (bfd_seek (abfd, (file_ptr) i_ehdrp->e_shoff, SEEK_SET) != 0
      || (bfd_write ((PTR) x_shdrp, sizeof (*x_shdrp), i_ehdrp->e_shnum, abfd)
          != sizeof (*x_shdrp) * i_ehdrp->e_shnum))
    return false;

  /* need to dump the string table too... */

  return true;
}

static long
elf_slurp_symbol_table (abfd, symptrs, dynamic)
     bfd *abfd;
     asymbol **symptrs;         /* Buffer for generated bfd symbols */
     boolean dynamic;
{
  Elf_Internal_Shdr *hdr;
  long symcount;                /* Number of external ELF symbols */
  elf_symbol_type *sym;         /* Pointer to current bfd symbol */
  elf_symbol_type *symbase;     /* Buffer for generated bfd symbols */
  Elf_Internal_Sym i_sym;
  Elf_External_Sym *x_symp = NULL;

  /* Read each raw ELF symbol, converting from external ELF form to
     internal ELF form, and then using the information to create a
     canonical bfd symbol table entry.

     Note that we allocate the initial bfd canonical symbol buffer
     based on a one-to-one mapping of the ELF symbols to canonical
     symbols.  We actually use all the ELF symbols, so there will be no
     space left over at the end.  When we have all the symbols, we
     build the caller's pointer vector. */

  if (dynamic)
    hdr = &elf_tdata (abfd)->dynsymtab_hdr;
  else
    hdr = &elf_tdata (abfd)->symtab_hdr;
  if (bfd_seek (abfd, hdr->sh_offset, SEEK_SET) == -1)
    return -1;

  symcount = hdr->sh_size / sizeof (Elf_External_Sym);

  if (symcount == 0)
    sym = symbase = NULL;
  else
    {
      long i;

      if (bfd_seek (abfd, hdr->sh_offset, SEEK_SET) == -1)
        return -1;

      symbase = ((elf_symbol_type *)
                 bfd_zalloc (abfd, symcount * sizeof (elf_symbol_type)));
      if (symbase == (elf_symbol_type *) NULL)
        return -1;
      sym = symbase;

      /* Temporarily allocate room for the raw ELF symbols.  */
      x_symp = ((Elf_External_Sym *)
                bfd_malloc (symcount * sizeof (Elf_External_Sym)));
      if (x_symp == NULL && symcount != 0)
        goto error_return;

      if (bfd_read ((PTR) x_symp, sizeof (Elf_External_Sym), symcount, abfd)
          != symcount * sizeof (Elf_External_Sym))
        goto error_return;
      /* Skip first symbol, which is a null dummy.  */
      for (i = 1; i < symcount; i++)
        {
          elf_swap_symbol_in (abfd, x_symp + i, &i_sym);
          memcpy (&sym->internal_elf_sym, &i_sym, sizeof (Elf_Internal_Sym));
#ifdef ELF_KEEP_EXTSYM
          memcpy (&sym->native_elf_sym, x_symp + i, sizeof (Elf_External_Sym));
#endif
          sym->symbol.the_bfd = abfd;

          sym->symbol.name = bfd_elf_string_from_elf_section (abfd,
                                                              hdr->sh_link,
                                                              i_sym.st_name);

          sym->symbol.value = i_sym.st_value;

          if (i_sym.st_shndx > 0 && i_sym.st_shndx < SHN_LORESERVE)
            {
              sym->symbol.section = section_from_elf_index (abfd,
                                                            i_sym.st_shndx);
              if (sym->symbol.section == NULL)
                {
                  /* This symbol is in a section for which we did not
                     create a BFD section.  Just use bfd_abs_section,
                     although it is wrong.  FIXME.  */
                  sym->symbol.section = bfd_abs_section_ptr;
                }
            }
          else if (i_sym.st_shndx == SHN_ABS)
            {
              sym->symbol.section = bfd_abs_section_ptr;
            }
          else if (i_sym.st_shndx == SHN_COMMON)
            {
              sym->symbol.section = bfd_com_section_ptr;
              /* Elf puts the alignment into the `value' field, and
                 the size into the `size' field.  BFD wants to see the
                 size in the value field, and doesn't care (at the
                 moment) about the alignment.  */
              sym->symbol.value = i_sym.st_size;
            }
          else if (i_sym.st_shndx == SHN_UNDEF)
            {
              sym->symbol.section = bfd_und_section_ptr;
            }
          else
            sym->symbol.section = bfd_abs_section_ptr;

          sym->symbol.value -= sym->symbol.section->vma;

          switch (ELF_ST_BIND (i_sym.st_info))
            {
            case STB_LOCAL:
              sym->symbol.flags |= BSF_LOCAL;
              break;
            case STB_GLOBAL:
              if (i_sym.st_shndx != SHN_UNDEF
                  && i_sym.st_shndx != SHN_COMMON)
                sym->symbol.flags |= BSF_GLOBAL;
              break;
            case STB_WEAK:
              sym->symbol.flags |= BSF_WEAK;
              break;
            }

          switch (ELF_ST_TYPE (i_sym.st_info))
            {
            case STT_SECTION:
              sym->symbol.flags |= BSF_SECTION_SYM | BSF_DEBUGGING;
              break;
            case STT_FILE:
              sym->symbol.flags |= BSF_FILE | BSF_DEBUGGING;
              break;
            case STT_FUNC:
              sym->symbol.flags |= BSF_FUNCTION;
              break;
            }

          if (dynamic)
            sym->symbol.flags |= BSF_DYNAMIC;

          /* Do some backend-specific processing on this symbol.  */
          {
            struct elf_backend_data *ebd = get_elf_backend_data (abfd);
            if (ebd->elf_backend_symbol_processing)
              (*ebd->elf_backend_symbol_processing) (abfd, &sym->symbol);
          }

          sym++;
        }
    }

  /* Do some backend-specific processing on this symbol table.  */
  {
    struct elf_backend_data *ebd = get_elf_backend_data (abfd);
    if (ebd->elf_backend_symbol_table_processing)
      (*ebd->elf_backend_symbol_table_processing) (abfd, symbase, symcount);
  }

  /* We rely on the zalloc to clear out the final symbol entry.  */

  symcount = sym - symbase;

  /* Fill in the user's symbol pointer vector if needed.  */
  if (symptrs)
    {
      long l = symcount;

      sym = symbase;
      while (l-- > 0)
        {
          *symptrs++ = &sym->symbol;
          sym++;
        }
      *symptrs = 0;             /* Final null pointer */
    }

  if (x_symp != NULL)
    free (x_symp);
  return symcount;
error_return:
  if (x_symp != NULL)
    free (x_symp);
  return -1;
}

/* Read in and swap the external relocs.  */

static boolean
elf_slurp_reloc_table (abfd, asect, symbols)
     bfd *abfd;
     asection *asect;
     asymbol **symbols;
{
  struct elf_backend_data * const ebd = get_elf_backend_data (abfd);
  struct bfd_elf_section_data * const d = elf_section_data (asect);
  PTR allocated = NULL;
  bfd_byte *native_relocs;
  arelent *relents;
  arelent *relent;
  unsigned int i;
  int entsize;

  if (asect->relocation != NULL
      || (asect->flags & SEC_RELOC) == 0
      || asect->reloc_count == 0)
    return true;

  BFD_ASSERT (asect->rel_filepos == d->rel_hdr.sh_offset
              && (asect->reloc_count
                  == d->rel_hdr.sh_size / d->rel_hdr.sh_entsize));

  allocated = (PTR) bfd_malloc ((size_t) d->rel_hdr.sh_size);
  if (allocated == NULL)
    goto error_return;

  if (bfd_seek (abfd, asect->rel_filepos, SEEK_SET) != 0
      || (bfd_read (allocated, 1, d->rel_hdr.sh_size, abfd)
          != d->rel_hdr.sh_size))
    goto error_return;

  native_relocs = (bfd_byte *) allocated;

  relents = ((arelent *)
             bfd_alloc (abfd, asect->reloc_count * sizeof (arelent)));
  if (relents == NULL)
    goto error_return;

  entsize = d->rel_hdr.sh_entsize;
  BFD_ASSERT (entsize == sizeof (Elf_External_Rel)
              || entsize == sizeof (Elf_External_Rela));

  for (i = 0, relent = relents;
       i < asect->reloc_count;
       i++, relent++, native_relocs += entsize)
    {
      Elf_Internal_Rela rela;
      Elf_Internal_Rel rel;

      if (entsize == sizeof (Elf_External_Rela))
        elf_swap_reloca_in (abfd, (Elf_External_Rela *) native_relocs, &rela);
      else
        {
          elf_swap_reloc_in (abfd, (Elf_External_Rel *) native_relocs, &rel);
          rela.r_offset = rel.r_offset;
          rela.r_info = rel.r_info;
          rela.r_addend = 0;
        }

      /* The address of an ELF reloc is section relative for an object
         file, and absolute for an executable file or shared library.
         The address of a BFD reloc is always section relative.  */
      if ((abfd->flags & (EXEC_P | DYNAMIC)) == 0)
        relent->address = rela.r_offset;
      else
        relent->address = rela.r_offset - asect->vma;

      if (ELF_R_SYM (rela.r_info) == 0)
        relent->sym_ptr_ptr = bfd_abs_section_ptr->symbol_ptr_ptr;
      else
        {
          asymbol **ps, *s;

          ps = symbols + ELF_R_SYM (rela.r_info) - 1;
          s = *ps;

          /* Canonicalize ELF section symbols.  FIXME: Why?  */
          if ((s->flags & BSF_SECTION_SYM) == 0)
            relent->sym_ptr_ptr = ps;
          else
            relent->sym_ptr_ptr = s->section->symbol_ptr_ptr;
        }

      relent->addend = rela.r_addend;

      if (entsize == sizeof (Elf_External_Rela))
        (*ebd->elf_info_to_howto) (abfd, relent, &rela);
      else
        (*ebd->elf_info_to_howto_rel) (abfd, relent, &rel);
    }

  asect->relocation = relents;

  if (allocated != NULL)
    free (allocated);

  return true;

 error_return:
  if (allocated != NULL)
    free (allocated);
  return false;
}

#ifdef DEBUG
static void
elf_debug_section (num, hdr)
     int num;
     Elf_Internal_Shdr *hdr;
{
  fprintf (stderr, "\nSection#%d '%s' 0x%.8lx\n", num,
           hdr->bfd_section != NULL ? hdr->bfd_section->name : "",
           (long) hdr);
  fprintf (stderr,
           "sh_name      = %ld\tsh_type      = %ld\tsh_flags     = %ld\n",
           (long) hdr->sh_name,
           (long) hdr->sh_type,
           (long) hdr->sh_flags);
  fprintf (stderr,
           "sh_addr      = %ld\tsh_offset    = %ld\tsh_size      = %ld\n",
           (long) hdr->sh_addr,
           (long) hdr->sh_offset,
           (long) hdr->sh_size);
  fprintf (stderr,
           "sh_link      = %ld\tsh_info      = %ld\tsh_addralign = %ld\n",
           (long) hdr->sh_link,
           (long) hdr->sh_info,
           (long) hdr->sh_addralign);
  fprintf (stderr, "sh_entsize   = %ld\n",
           (long) hdr->sh_entsize);
  fflush (stderr);
}

static void
elf_debug_file (ehdrp)
     Elf_Internal_Ehdr *ehdrp;
{
  fprintf (stderr, "e_entry      = 0x%.8lx\n", (long) ehdrp->e_entry);
  fprintf (stderr, "e_phoff      = %ld\n", (long) ehdrp->e_phoff);
  fprintf (stderr, "e_phnum      = %ld\n", (long) ehdrp->e_phnum);
  fprintf (stderr, "e_phentsize  = %ld\n", (long) ehdrp->e_phentsize);
  fprintf (stderr, "e_shoff      = %ld\n", (long) ehdrp->e_shoff);
  fprintf (stderr, "e_shnum      = %ld\n", (long) ehdrp->e_shnum);
  fprintf (stderr, "e_shentsize  = %ld\n", (long) ehdrp->e_shentsize);
}

static char *
elf_symbol_flags (flags)
     flagword flags;
{
  static char buffer[1024];

  buffer[0] = '\0';
  if (flags & BSF_LOCAL)
    strcat (buffer, " local");

  if (flags & BSF_GLOBAL)
    strcat (buffer, " global");

  if (flags & BSF_DEBUGGING)
    strcat (buffer, " debug");

  if (flags & BSF_FUNCTION)
    strcat (buffer, " function");

  if (flags & BSF_KEEP)
    strcat (buffer, " keep");

  if (flags & BSF_KEEP_G)
    strcat (buffer, " keep_g");

  if (flags & BSF_WEAK)
    strcat (buffer, " weak");

  if (flags & BSF_SECTION_SYM)
    strcat (buffer, " section-sym");

  if (flags & BSF_OLD_COMMON)
    strcat (buffer, " old-common");

  if (flags & BSF_NOT_AT_END)
    strcat (buffer, " not-at-end");

  if (flags & BSF_CONSTRUCTOR)
    strcat (buffer, " constructor");

  if (flags & BSF_WARNING)
    strcat (buffer, " warning");

  if (flags & BSF_INDIRECT)
    strcat (buffer, " indirect");

  if (flags & BSF_FILE)
    strcat (buffer, " file");

  if (flags & DYNAMIC)
    strcat (buffer, " dynamic");

  if (flags & ~(BSF_LOCAL
                | BSF_GLOBAL
                | BSF_DEBUGGING
                | BSF_FUNCTION
                | BSF_KEEP
                | BSF_KEEP_G
                | BSF_WEAK
                | BSF_SECTION_SYM
                | BSF_OLD_COMMON
                | BSF_NOT_AT_END
                | BSF_CONSTRUCTOR
                | BSF_WARNING
                | BSF_INDIRECT
                | BSF_FILE
                | BSF_DYNAMIC))
    strcat (buffer, " unknown-bits");

  return buffer;
}
#endif
\f
#include "elfcore.h"
#include "elflink.h"
\f
/* Size-dependent data and functions.  */
const struct elf_size_info NAME(_bfd_elf,size_info) = {
  sizeof (Elf_External_Ehdr),
  sizeof (Elf_External_Phdr),
  sizeof (Elf_External_Shdr),
  sizeof (Elf_External_Rel),
  sizeof (Elf_External_Rela),
  sizeof (Elf_External_Sym),
  sizeof (Elf_External_Dyn),
  sizeof (Elf_External_Note),

  ARCH_SIZE, FILE_ALIGN,
  ELFCLASS, EV_CURRENT,
  write_out_phdrs,
  write_shdrs_and_ehdr,
  write_relocs,
  elf_swap_symbol_out,
  elf_slurp_reloc_table,
  elf_slurp_symbol_table,
};