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/* BFD back-end data structures for ELF files.

   Copyright 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001

   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.  */

#ifndef _LIBELF_H_

#define _LIBELF_H_ 1

#include "elf/common.h"

#include "elf/internal.h"

#include "elf/external.h"

#include "bfdlink.h"

/* The number of entries in a section is its size divided by the size

   of a single entry.  This is normally only applicaable to reloc and

   symbol table sections.  */

#define NUM_SHDR_ENTRIES(shdr) ((shdr)->sh_size / (shdr)->sh_entsize)

/* If size isn't specified as 64 or 32, NAME macro should fail.  */

#ifndef NAME

#if ARCH_SIZE==64

#define NAME(x,y) CAT4(x,64,_,y)

#endif

#if ARCH_SIZE==32

#define NAME(x,y) CAT4(x,32,_,y)

#endif

#endif

#ifndef NAME

#define NAME(x,y) CAT4(x,NOSIZE,_,y)

#endif

#define ElfNAME(X)      NAME(Elf,X)

#define elfNAME(X)      NAME(elf,X)

/* Information held for an ELF symbol.  The first field is the

   corresponding asymbol.  Every symbol is an ELF file is actually a

   pointer to this structure, although it is often handled as a

   pointer to an asymbol.  */

typedef struct

{

  /* The BFD symbol.  */

  asymbol symbol;

  /* ELF symbol information.  */

  Elf_Internal_Sym internal_elf_sym;

  /* Backend specific information.  */

  union

    {

      unsigned int hppa_arg_reloc;

      PTR mips_extr;

      PTR any;

    }

  tc_data;

  /* Version information.  This is from an Elf_Internal_Versym

     structure in a SHT_GNU_versym section.  It is zero if there is no

     version information.  */

  unsigned short version;

} elf_symbol_type;

/* ELF linker hash table entries.  */

struct elf_link_hash_entry

{

  struct bfd_link_hash_entry root;

  /* Symbol index in output file.  This is initialized to -1.  It is

     set to -2 if the symbol is used by a reloc.  */

  long indx;

  /* Symbol size.  */

  bfd_size_type size;

  /* Symbol index as a dynamic symbol.  Initialized to -1, and remains

     -1 if this is not a dynamic symbol.  */

  /* ??? Note that this is consistently used as a synonym for tests

     against whether we can perform various simplifying transformations

     to the code.  (E.g. changing a pc-relative jump to a PLT entry

     into a pc-relative jump to the target function.)  That test, which

     is often relatively complex, and someplaces wrong or incomplete,

     should really be replaced by a predicate in elflink.c.

     End result: this field -1 does not indicate that the symbol is

     not in the dynamic symbol table, but rather that the symbol is

     not visible outside this DSO.  */

  long dynindx;

  /* String table index in .dynstr if this is a dynamic symbol.  */

  unsigned long dynstr_index;

  /* If this is a weak defined symbol from a dynamic object, this

     field points to a defined symbol with the same value, if there is

     one.  Otherwise it is NULL.  */

  struct elf_link_hash_entry *weakdef;

  /* If this symbol requires an entry in the global offset table, the

     processor specific backend uses this field to track usage and

     final offset.  We use a union and two names primarily to document

     the intent of any particular piece of code.  The field should be

     used as a count until size_dynamic_sections, at which point the

     contents of the .got is fixed.  Afterward, if this field is -1,

     then the symbol does not require a global offset table entry.  */

  union

    {

      bfd_signed_vma refcount;

      bfd_vma offset;

    } got;

  /* Same, but tracks a procedure linkage table entry.  */

  union

    {

      bfd_signed_vma refcount;

      bfd_vma offset;

    } plt;

  /* If this symbol is used in the linker created sections, the processor

     specific backend uses this field to map the field into the offset

     from the beginning of the section.  */

  struct elf_linker_section_pointers *linker_section_pointer;

  /* Version information.  */

  union

  {

    /* This field is used for a symbol which is not defined in a

       regular object.  It points to the version information read in

       from the dynamic object.  */

    Elf_Internal_Verdef *verdef;

    /* This field is used for a symbol which is defined in a regular

       object.  It is set up in size_dynamic_sections.  It points to

       the version information we should write out for this symbol.  */

    struct bfd_elf_version_tree *vertree;

  } verinfo;

  /* Virtual table entry use information.  This array is nominally of size

     size/sizeof(target_void_pointer), though we have to be able to assume

     and track a size while the symbol is still undefined.  It is indexed

     via offset/sizeof(target_void_pointer).  */

  size_t vtable_entries_size;

  boolean *vtable_entries_used;

  /* Virtual table derivation info.  */

  struct elf_link_hash_entry *vtable_parent;

  /* Symbol type (STT_NOTYPE, STT_OBJECT, etc.).  */

  char type;

  /* Symbol st_other value, symbol visibility.  */

  unsigned char other;

  /* Hash value of the name computed using the ELF hash function.  */

  unsigned long elf_hash_value;

  /* Some flags; legal values follow.  */

  unsigned short elf_link_hash_flags;

  /* Symbol is referenced by a non-shared object.  */

#define ELF_LINK_HASH_REF_REGULAR 01

  /* Symbol is defined by a non-shared object.  */

#define ELF_LINK_HASH_DEF_REGULAR 02

  /* Symbol is referenced by a shared object.  */

#define ELF_LINK_HASH_REF_DYNAMIC 04

  /* Symbol is defined by a shared object.  */

#define ELF_LINK_HASH_DEF_DYNAMIC 010

  /* Symbol has a non-weak reference from a non-shared object.  */

#define ELF_LINK_HASH_REF_REGULAR_NONWEAK 020

  /* Dynamic symbol has been adjustd.  */

#define ELF_LINK_HASH_DYNAMIC_ADJUSTED 040

  /* Symbol needs a copy reloc.  */

#define ELF_LINK_HASH_NEEDS_COPY 0100

  /* Symbol needs a procedure linkage table entry.  */

#define ELF_LINK_HASH_NEEDS_PLT 0200

  /* Symbol appears in a non-ELF input file.  */

#define ELF_LINK_NON_ELF 0400

  /* Symbol should be marked as hidden in the version information.  */

#define ELF_LINK_HIDDEN 01000

  /* Symbol was forced to local scope due to a version script file.  */

#define ELF_LINK_FORCED_LOCAL 02000

  /* Symbol was marked during garbage collection.  */

#define ELF_LINK_HASH_MARK 04000

  /* Symbol is referenced by a non-GOT/non-PLT relocation.  This is

     not currently set by all the backends.  */

#define ELF_LINK_NON_GOT_REF 010000

};

/* Records local symbols to be emitted in the dynamic symbol table.  */

struct elf_link_local_dynamic_entry

{

  struct elf_link_local_dynamic_entry *next;

  /* The input bfd this symbol came from.  */

  bfd *input_bfd;

  /* The index of the local symbol being copied.  */

  long input_indx;

  /* The index in the outgoing dynamic symbol table.  */

  long dynindx;

  /* A copy of the input symbol.  */

  Elf_Internal_Sym isym;

};

/* ELF linker hash table.  */

struct elf_link_hash_table

{

  struct bfd_link_hash_table root;

  /* Whether we have created the special dynamic sections required

     when linking against or generating a shared object.  */

  boolean dynamic_sections_created;

  /* The BFD used to hold special sections created by the linker.

     This will be the first BFD found which requires these sections to

     be created.  */

  bfd *dynobj;

  /* The number of symbols found in the link which must be put into

     the .dynsym section.  */

  bfd_size_type dynsymcount;

  /* The string table of dynamic symbols, which becomes the .dynstr

     section.  */

  struct bfd_strtab_hash *dynstr;

  /* The number of buckets in the hash table in the .hash section.

     This is based on the number of dynamic symbols.  */

  bfd_size_type bucketcount;

  /* A linked list of DT_NEEDED names found in dynamic objects

     included in the link.  */

  struct bfd_link_needed_list *needed;

  /* The _GLOBAL_OFFSET_TABLE_ symbol.  */

  struct elf_link_hash_entry *hgot;

  /* A pointer to information used to link stabs in sections.  */

  PTR stab_info;

  /* A pointer to information used to merge SEC_MERGE sections.  */

  PTR merge_info;

  /* A linked list of local symbols to be added to .dynsym.  */

  struct elf_link_local_dynamic_entry *dynlocal;

  /* A linked list of DT_RPATH/DT_RUNPATH names found in dynamic

     objects included in the link.  */

  struct bfd_link_needed_list *runpath;

};

/* Look up an entry in an ELF linker hash table.  */

#define elf_link_hash_lookup(table, string, create, copy, follow)       \

  ((struct elf_link_hash_entry *)                                       \

   bfd_link_hash_lookup (&(table)->root, (string), (create),            \

                         (copy), (follow)))

/* Traverse an ELF linker hash table.  */

#define elf_link_hash_traverse(table, func, info)                       \

  (bfd_link_hash_traverse                                               \

   (&(table)->root,                                                     \

    (boolean (*) PARAMS ((struct bfd_link_hash_entry *, PTR))) (func),  \

    (info)))

/* Get the ELF linker hash table from a link_info structure.  */

#define elf_hash_table(p) ((struct elf_link_hash_table *) ((p)->hash))

/* Constant information held for an ELF backend.  */

struct elf_size_info {

  unsigned char sizeof_ehdr, sizeof_phdr, sizeof_shdr;

  unsigned char sizeof_rel, sizeof_rela, sizeof_sym, sizeof_dyn, sizeof_note;

  /* The size of entries in the .hash section.  */

  unsigned char sizeof_hash_entry;

  /* The number of internal relocations to allocate per external

     relocation entry.  */

  unsigned char int_rels_per_ext_rel;

  unsigned char arch_size, file_align;

  unsigned char elfclass, ev_current;

  int (*write_out_phdrs) PARAMS ((bfd *, const Elf_Internal_Phdr *, int));

  boolean (*write_shdrs_and_ehdr) PARAMS ((bfd *));

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

  void (*swap_symbol_out) PARAMS ((bfd *, const Elf_Internal_Sym *, PTR));

  boolean (*slurp_reloc_table)

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

  long (*slurp_symbol_table) PARAMS ((bfd *, asymbol **, boolean));

  void (*swap_dyn_in) PARAMS ((bfd *, const PTR, Elf_Internal_Dyn *));

  void (*swap_dyn_out) PARAMS ((bfd *, const Elf_Internal_Dyn *, PTR));

  /* This function, if defined, is called to swap in a REL

     relocation.  If an external relocation corresponds to more than

     one internal relocation, then all relocations are swapped in at

     once.  */

  void (*swap_reloc_in)

    PARAMS ((bfd *, const bfd_byte *, Elf_Internal_Rel *));

  /* This function, if defined, is called to swap out a REL

     relocation.  */

  void (*swap_reloc_out)

    PARAMS ((bfd *, const Elf_Internal_Rel *, bfd_byte *));

  /* This function, if defined, is called to swap in a RELA

     relocation.  If an external relocation corresponds to more than

     one internal relocation, then all relocations are swapped in at

     once.  */

  void (*swap_reloca_in)

    PARAMS ((bfd *, const bfd_byte *, Elf_Internal_Rela *));

  /* This function, if defined, is called to swap out a RELA

     relocation.  */

  void (*swap_reloca_out)

    PARAMS ((bfd *, const Elf_Internal_Rela *, bfd_byte *));

};

#define elf_symbol_from(ABFD,S) \

        (((S)->the_bfd->xvec->flavour == bfd_target_elf_flavour \

          && (S)->the_bfd->tdata.elf_obj_data != 0) \

         ? (elf_symbol_type *) (S) \

         : 0)

struct elf_backend_data

{

  /* The architecture for this backend.  */

  enum bfd_architecture arch;

  /* The ELF machine code (EM_xxxx) for this backend.  */

  int elf_machine_code;

  /* The maximum page size for this backend.  */

  bfd_vma maxpagesize;

  /* A function to translate an ELF RELA relocation to a BFD arelent

     structure.  */

  void (*elf_info_to_howto) PARAMS ((bfd *, arelent *,

                                     Elf_Internal_Rela *));

  /* A function to translate an ELF REL relocation to a BFD arelent

     structure.  */

  void (*elf_info_to_howto_rel) PARAMS ((bfd *, arelent *,

                                         Elf_Internal_Rel *));

  /* A function to determine whether a symbol is global when

     partitioning the symbol table into local and global symbols.

     This should be NULL for most targets, in which case the correct

     thing will be done.  MIPS ELF, at least on the Irix 5, has

     special requirements.  */

  boolean (*elf_backend_sym_is_global) PARAMS ((bfd *, asymbol *));

  /* The remaining functions are hooks which are called only if they

     are not NULL.  */

  /* A function to permit a backend specific check on whether a

     particular BFD format is relevant for an object file, and to

     permit the backend to set any global information it wishes.  When

     this is called elf_elfheader is set, but anything else should be

     used with caution.  If this returns false, the check_format

     routine will return a bfd_error_wrong_format error.  */

  boolean (*elf_backend_object_p) PARAMS ((bfd *));

  /* A function to do additional symbol processing when reading the

     ELF symbol table.  This is where any processor-specific special

     section indices are handled.  */

  void (*elf_backend_symbol_processing) PARAMS ((bfd *, asymbol *));

  /* A function to do additional symbol processing after reading the

     entire ELF symbol table.  */

  boolean (*elf_backend_symbol_table_processing) PARAMS ((bfd *,

                                                          elf_symbol_type *,

                                                          unsigned int));

   /* A function to set the type of the info field.  Processor-specific

     types should be handled here.  */

  int (*elf_backend_get_symbol_type) PARAMS (( Elf_Internal_Sym *, int));

  /* A function to do additional processing on the ELF section header

     just before writing it out.  This is used to set the flags and

     type fields for some sections, or to actually write out data for

     unusual sections.  */

  boolean (*elf_backend_section_processing) PARAMS ((bfd *,

                                                     Elf32_Internal_Shdr *));

  /* A function to handle unusual section types when creating BFD

     sections from ELF sections.  */

  boolean (*elf_backend_section_from_shdr) PARAMS ((bfd *,

                                                    Elf32_Internal_Shdr *,

                                                    char *));

  /* A function to convert machine dependent section header flags to

     BFD internal section header flags.  */

  boolean (*elf_backend_section_flags) PARAMS ((flagword *,

                                                Elf32_Internal_Shdr *));

  /* A function to handle unusual program segment types when creating BFD

     sections from ELF program segments.  */

  boolean (*elf_backend_section_from_phdr) PARAMS ((bfd *,

                                                    Elf32_Internal_Phdr *,

                                                    int));

  /* A function to set up the ELF section header for a BFD section in

     preparation for writing it out.  This is where the flags and type

     fields are set for unusual sections.  */

  boolean (*elf_backend_fake_sections) PARAMS ((bfd *, Elf32_Internal_Shdr *,

                                                asection *));

  /* A function to get the ELF section index for a BFD section.  If

     this returns true, the section was found.  If it is a normal ELF

     section, *RETVAL should be left unchanged.  If it is not a normal

     ELF section *RETVAL should be set to the SHN_xxxx index.  */

  boolean (*elf_backend_section_from_bfd_section)

    PARAMS ((bfd *, Elf32_Internal_Shdr *, asection *, int *retval));

  /* If this field is not NULL, it is called by the add_symbols phase

     of a link just before adding a symbol to the global linker hash

     table.  It may modify any of the fields as it wishes.  If *NAME

     is set to NULL, the symbol will be skipped rather than being

     added to the hash table.  This function is responsible for

     handling all processor dependent symbol bindings and section

     indices, and must set at least *FLAGS and *SEC for each processor

     dependent case; failure to do so will cause a link error.  */

  boolean (*elf_add_symbol_hook)

    PARAMS ((bfd *abfd, struct bfd_link_info *info,

             const Elf_Internal_Sym *, const char **name,

             flagword *flags, asection **sec, bfd_vma *value));

  /* If this field is not NULL, it is called by the elf_link_output_sym

     phase of a link for each symbol which will appear in the object file.  */

  boolean (*elf_backend_link_output_symbol_hook)

    PARAMS ((bfd *, struct bfd_link_info *info, const char *,

             Elf_Internal_Sym *, asection *));

  /* The CREATE_DYNAMIC_SECTIONS function is called by the ELF backend

     linker the first time it encounters a dynamic object in the link.

     This function must create any sections required for dynamic

     linking.  The ABFD argument is a dynamic object.  The .interp,

     .dynamic, .dynsym, .dynstr, and .hash functions have already been

     created, and this function may modify the section flags if

     desired.  This function will normally create the .got and .plt

     sections, but different backends have different requirements.  */

  boolean (*elf_backend_create_dynamic_sections)

    PARAMS ((bfd *abfd, struct bfd_link_info *info));

  /* The CHECK_RELOCS function is called by the add_symbols phase of

     the ELF backend linker.  It is called once for each section with

     relocs of an object file, just after the symbols for the object

     file have been added to the global linker hash table.  The

     function must look through the relocs and do any special handling

     required.  This generally means allocating space in the global

     offset table, and perhaps allocating space for a reloc.  The

     relocs are always passed as Rela structures; if the section

     actually uses Rel structures, the r_addend field will always be

     zero.  */

  boolean (*check_relocs)

    PARAMS ((bfd *abfd, struct bfd_link_info *info, asection *o,

             const Elf_Internal_Rela *relocs));

  /* The ADJUST_DYNAMIC_SYMBOL function is called by the ELF backend

     linker for every symbol which is defined by a dynamic object and

     referenced by a regular object.  This is called after all the

     input files have been seen, but before the SIZE_DYNAMIC_SECTIONS

     function has been called.  The hash table entry should be

     bfd_link_hash_defined ore bfd_link_hash_defweak, and it should be

     defined in a section from a dynamic object.  Dynamic object

     sections are not included in the final link, and this function is

     responsible for changing the value to something which the rest of

     the link can deal with.  This will normally involve adding an

     entry to the .plt or .got or some such section, and setting the

     symbol to point to that.  */

  boolean (*elf_backend_adjust_dynamic_symbol)

    PARAMS ((struct bfd_link_info *info, struct elf_link_hash_entry *h));

  /* The ALWAYS_SIZE_SECTIONS function is called by the backend linker

     after all the linker input files have been seen but before the

     section sizes have been set.  This is called after

     ADJUST_DYNAMIC_SYMBOL, but before SIZE_DYNAMIC_SECTIONS.  */

  boolean (*elf_backend_always_size_sections)

    PARAMS ((bfd *output_bfd, struct bfd_link_info *info));

  /* The SIZE_DYNAMIC_SECTIONS function is called by the ELF backend

     linker after all the linker input files have been seen but before

     the sections sizes have been set.  This is called after

     ADJUST_DYNAMIC_SYMBOL has been called on all appropriate symbols.

     It is only called when linking against a dynamic object.  It must

     set the sizes of the dynamic sections, and may fill in their

     contents as well.  The generic ELF linker can handle the .dynsym,

     .dynstr and .hash sections.  This function must handle the

     .interp section and any sections created by the

     CREATE_DYNAMIC_SECTIONS entry point.  */

  boolean (*elf_backend_size_dynamic_sections)

    PARAMS ((bfd *output_bfd, struct bfd_link_info *info));

  /* The RELOCATE_SECTION function is called by the ELF backend linker

     to handle the relocations for a section.

     The relocs are always passed as Rela structures; if the section

     actually uses Rel structures, the r_addend field will always be

     zero.

     This function is responsible for adjust the section contents as

     necessary, and (if using Rela relocs and generating a

     relocateable output file) adjusting the reloc addend as

     necessary.

     This function does not have to worry about setting the reloc

     address or the reloc symbol index.

     LOCAL_SYMS is a pointer to the swapped in local symbols.

     LOCAL_SECTIONS is an array giving the section in the input file

     corresponding to the st_shndx field of each local symbol.

     The global hash table entry for the global symbols can be found

     via elf_sym_hashes (input_bfd).

     When generating relocateable output, this function must handle

     STB_LOCAL/STT_SECTION symbols specially.  The output symbol is

     going to be the section symbol corresponding to the output

     section, which means that the addend must be adjusted

     accordingly.  */

  boolean (*elf_backend_relocate_section)

    PARAMS ((bfd *output_bfd, struct bfd_link_info *info,

             bfd *input_bfd, asection *input_section, bfd_byte *contents,

             Elf_Internal_Rela *relocs, Elf_Internal_Sym *local_syms,

             asection **local_sections));

  /* The FINISH_DYNAMIC_SYMBOL function is called by the ELF backend

     linker just before it writes a symbol out to the .dynsym section.

     The processor backend may make any required adjustment to the

     symbol.  It may also take the opportunity to set contents of the

     dynamic sections.  Note that FINISH_DYNAMIC_SYMBOL is called on

     all .dynsym symbols, while ADJUST_DYNAMIC_SYMBOL is only called

     on those symbols which are defined by a dynamic object.  */

  boolean (*elf_backend_finish_dynamic_symbol)

    PARAMS ((bfd *output_bfd, struct bfd_link_info *info,

             struct elf_link_hash_entry *h, Elf_Internal_Sym *sym));

  /* The FINISH_DYNAMIC_SECTIONS function is called by the ELF backend

     linker just before it writes all the dynamic sections out to the

     output file.  The FINISH_DYNAMIC_SYMBOL will have been called on

     all dynamic symbols.  */

  boolean (*elf_backend_finish_dynamic_sections)

    PARAMS ((bfd *output_bfd, struct bfd_link_info *info));

  /* A function to do any beginning processing needed for the ELF file

     before building the ELF headers and computing file positions.  */

  void (*elf_backend_begin_write_processing)

    PARAMS ((bfd *, struct bfd_link_info *));

  /* A function to do any final processing needed for the ELF file

     before writing it out.  The LINKER argument is true if this BFD

     was created by the ELF backend linker.  */

  void (*elf_backend_final_write_processing)

    PARAMS ((bfd *, boolean linker));

  /* This function is called by get_program_header_size.  It should

     return the number of additional program segments which this BFD

     will need.  It should return -1 on error.  */

  int (*elf_backend_additional_program_headers) PARAMS ((bfd *));

  /* This function is called to modify an existing segment map in a

     backend specific fashion.  */

  boolean (*elf_backend_modify_segment_map) PARAMS ((bfd *));

  /* This function is called during section gc to discover the section a

     particular relocation refers to.  It need not be defined for hosts

     that have no queer relocation types.  */

  asection * (*gc_mark_hook)

    PARAMS ((bfd *abfd, struct bfd_link_info *, Elf_Internal_Rela *,

             struct elf_link_hash_entry *h, Elf_Internal_Sym *));

  /* This function, if defined, is called during the sweep phase of gc

     in order that a backend might update any data structures it might

     be maintaining.  */

  boolean (*gc_sweep_hook)

    PARAMS ((bfd *abfd, struct bfd_link_info *info, asection *o,

             const Elf_Internal_Rela *relocs));

  /* This function, if defined, is called after the ELF headers have

     been created.  This allows for things like the OS and ABI versions

     to be changed.  */

  void (*elf_backend_post_process_headers)

    PARAMS ((bfd *, struct bfd_link_info *));

  /* This function, if defined, prints a symbol to file and returns the

     name of the symbol to be printed.  It should return NULL to fall

     back to default symbol printing.  */

  const char *(*elf_backend_print_symbol_all)

    PARAMS ((bfd *, PTR, asymbol *));

  /* This function, if defined, is called after all local symbols and

     global symbols converted to locals are emited into the symtab

     section.  It allows the backend to emit special global symbols

     not handled in the hash table.  */

  boolean (*elf_backend_output_arch_syms)

    PARAMS ((bfd *, struct bfd_link_info *, PTR,

            boolean (*) PARAMS ((PTR, const char *,

             Elf_Internal_Sym *, asection *))));

  /* Copy any information related to dynamic linking from a pre-existing

     symbol IND to a newly created symbol DIR.  */

  void (*elf_backend_copy_indirect_symbol)

    PARAMS ((struct elf_link_hash_entry *, struct elf_link_hash_entry *));

  /* Modify any information related to dynamic linking such that the

     symbol is not exported.  */

  void (*elf_backend_hide_symbol)

    PARAMS ((struct bfd_link_info *, struct elf_link_hash_entry *));

  /* Emit relocations.  Overrides default routine for emitting relocs,

     except during a relocatable link, or if all relocs are being emitted.  */

  void (*elf_backend_emit_relocs)

    PARAMS ((bfd *, asection *, Elf_Internal_Shdr *, Elf_Internal_Rela *));

  /* Count relocations.  Not called for relocatable links

     or if all relocs are being preserved in the output.  */

  unsigned int (*elf_backend_count_relocs)

    PARAMS ((asection *, Elf_Internal_Rela *));

  /* This function, if defined, is called when an NT_PRSTATUS note is found

     in a core file. */

  boolean (*elf_backend_grok_prstatus) PARAMS ((bfd *, Elf_Internal_Note *));

  /* This function, if defined, is called when an NT_PSINFO or NT_PRPSINFO

     note is found in a core file. */

  boolean (*elf_backend_grok_psinfo) PARAMS ((bfd *, Elf_Internal_Note *));

  /* The swapping table to use when dealing with ECOFF information.

     Used for the MIPS ELF .mdebug section.  */

  const struct ecoff_debug_swap *elf_backend_ecoff_debug_swap;

  /* Alternate EM_xxxx machine codes for this backend.  */

  int elf_machine_alt1;

  int elf_machine_alt2;

  const struct elf_size_info *s;

  /* offset of the _GLOBAL_OFFSET_TABLE_ symbol from the start of the

     .got section */

  bfd_vma got_symbol_offset;

  /* The size in bytes of the headers for the GOT and PLT.  This includes

     the so-called reserved entries on some systems.  */

  bfd_vma got_header_size;

  bfd_vma plt_header_size;

  /* This is true if the linker should act like collect and gather

     global constructors and destructors by name.  This is true for

     MIPS ELF because the Irix 5 tools can not handle the .init

     section.  */

  unsigned collect : 1;

  /* This is true if the linker should ignore changes to the type of a

     symbol.  This is true for MIPS ELF because some Irix 5 objects

     record undefined functions as STT_OBJECT although the definitions

     are STT_FUNC.  */

  unsigned type_change_ok : 1;

  /* Whether the backend may use REL relocations.  (Some backends use

     both REL and RELA relocations, and this flag is set for those

     backends.)  */

  unsigned may_use_rel_p : 1;

  /* Whether the backend may use RELA relocations.  (Some backends use

     both REL and RELA relocations, and this flag is set for those

     backends.)  */

  unsigned may_use_rela_p : 1;

  /* Whether the default relocation type is RELA.  If a backend with

     this flag set wants REL relocations for a particular section,

     it must note that explicitly.  Similarly, if this flag is clear,

     and the backend wants RELA relocations for a particular

     section.  */

  unsigned default_use_rela_p : 1;

  /* True if addresses "naturally" sign extend.  This is used when

     swapping in from Elf32 when BFD64.  */

  unsigned sign_extend_vma : 1;

  unsigned want_got_plt : 1;

  unsigned plt_readonly : 1;

  unsigned want_plt_sym : 1;

  unsigned plt_not_loaded : 1;

  unsigned plt_alignment : 4;

  unsigned can_gc_sections : 1;

  unsigned want_dynbss : 1;

};

/* Information stored for each BFD section in an ELF file.  This

   structure is allocated by elf_new_section_hook.  */

struct bfd_elf_section_data

{

  /* The ELF header for this section.  */

  Elf_Internal_Shdr this_hdr;

  /* The ELF header for the reloc section associated with this

     section, if any.  */

  Elf_Internal_Shdr rel_hdr;

  /* If there is a second reloc section associated with this section,

     as can happen on Irix 6, this field points to the header.  */

  Elf_Internal_Shdr *rel_hdr2;

  /* The number of relocations currently assigned to REL_HDR.  */

  unsigned int rel_count;

  /* The number of relocations currently assigned to REL_HDR2.  */

  unsigned int rel_count2;

  /* The ELF section number of this section.  Only used for an output

     file.  */

  int this_idx;

  /* The ELF section number of the reloc section indicated by

     REL_HDR if any.  Only used for an output file.  */

  int rel_idx;

  /* The ELF section number of the reloc section indicated by

     REL_HDR2 if any.  Only used for an output file.  */

  int rel_idx2;

  /* Used by the backend linker to store the symbol hash table entries

     associated with relocs against global symbols.  */

  struct elf_link_hash_entry **rel_hashes;

  /* A pointer to the swapped relocs.  If the section uses REL relocs,

     rather than RELA, all the r_addend fields will be zero.  This

     pointer may be NULL.  It is used by the backend linker.  */

  Elf_Internal_Rela *relocs;

  /* Used by the backend linker when generating a shared library to

     record the dynamic symbol index for a section symbol

     corresponding to this section.  A value of 0 means that there is

     no dynamic symbol for this section.  */

  long dynindx;

  /* A pointer used for .stab linking optimizations.  */

  PTR stab_info;

  /* A pointer used for SEC_MERGE optimizations.  */

  PTR merge_info;

  /* A pointer available for the processor specific ELF backend.  */

  PTR tdata;

  /* Nonzero if this section uses RELA relocations, rather than REL.  */

  unsigned int use_rela_p:1;

};

#define elf_section_data(sec)  ((struct bfd_elf_section_data*)sec->used_by_bfd)

#define get_elf_backend_data(abfd) \

  ((struct elf_backend_data *) (abfd)->xvec->backend_data)

/* Enumeration to specify the special section.  */

typedef enum elf_linker_section_enum

{

  LINKER_SECTION_UNKNOWN,               /* not used */

  LINKER_SECTION_GOT,                   /* .got section for global offset pointers */

  LINKER_SECTION_PLT,                   /* .plt section for generated procedure stubs */

  LINKER_SECTION_SDATA,                 /* .sdata/.sbss section for PowerPC */

  LINKER_SECTION_SDATA2,                /* .sdata2/.sbss2 section for PowerPC */

  LINKER_SECTION_MAX                    /* # of linker sections */

} elf_linker_section_enum_t;

/* Sections created by the linker.  */

typedef struct elf_linker_section

{

  char *name;                           /* name of the section */

  char *rel_name;                       /* name of the associated .rel{,a}. section */