include/bfdlink.h - binutils-gdb - Git at Google

 /* bfdlink.h -- header file for BFD link routines
    Copyright 1993, 94, 95, 96, 97, 1999 Free Software Foundation, Inc.
    Written by Steve Chamberlain and Ian Lance Taylor, 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 BFDLINK_H
 #define BFDLINK_H

 /* Which symbols to strip during a link.  */
 enum bfd_link_strip
 {
   strip_none,		/* Don't strip any symbols.  */
   strip_debugger,	/* Strip debugging symbols.  */
   strip_some,		/* keep_hash is the list of symbols to keep.  */
   strip_all		/* Strip all symbols.  */
 };

 /* Which local symbols to discard during a link.  This is irrelevant
    if strip_all is used.  */
 enum bfd_link_discard
 {
   discard_none,		/* Don't discard any locals.  */
   discard_l,		/* Discard local temporary symbols.  */
   discard_all		/* Discard all locals.  */
 };

 /* These are the possible types of an entry in the BFD link hash
    table.  */

 enum bfd_link_hash_type
 {
   bfd_link_hash_new,		/* Symbol is new.  */
   bfd_link_hash_undefined,	/* Symbol seen before, but undefined.  */
   bfd_link_hash_undefweak,	/* Symbol is weak and undefined.  */
   bfd_link_hash_defined,	/* Symbol is defined.  */
   bfd_link_hash_defweak,	/* Symbol is weak and defined.  */
   bfd_link_hash_common,		/* Symbol is common.  */
   bfd_link_hash_indirect,	/* Symbol is an indirect link.  */
   bfd_link_hash_warning		/* Like indirect, but warn if referenced.  */
 };

 /* The linking routines use a hash table which uses this structure for
    its elements.  */

 struct bfd_link_hash_entry
 {
   /* Base hash table entry structure.  */
   struct bfd_hash_entry root;
   /* Type of this entry.  */
   enum bfd_link_hash_type type;

   /* Undefined and common symbols are kept in a linked list through
      this field.  This field is not in the union because that would
      force us to remove entries from the list when we changed their
      type, which would force the list to be doubly linked, which would
      waste more memory.  When an undefined or common symbol is
      created, it should be added to this list, the head of which is in
      the link hash table itself.  As symbols are defined, they need
      not be removed from the list; anything which reads the list must
      doublecheck the symbol type.

      Weak symbols are not kept on this list.

      Defined and defweak symbols use this field as a reference marker.
      If the field is not NULL, or this structure is the tail of the
      undefined symbol list, the symbol has been referenced.  If the
      symbol is undefined and becomes defined, this field will
      automatically be non-NULL since the symbol will have been on the
      undefined symbol list.  */
   struct bfd_link_hash_entry *next;
   /* A union of information depending upon the type.  */
   union
     {
       /* Nothing is kept for bfd_hash_new.  */
       /* bfd_link_hash_undefined, bfd_link_hash_undefweak.  */
       struct
 	{
 	  bfd *abfd;		/* BFD symbol was found in.  */
 	} undef;
       /* bfd_link_hash_defined, bfd_link_hash_defweak.  */
       struct
 	{
 	  bfd_vma value;	/* Symbol value.  */
 	  asection *section;	/* Symbol section.  */
 	} def;
       /* bfd_link_hash_indirect, bfd_link_hash_warning.  */
       struct
 	{
 	  struct bfd_link_hash_entry *link;	/* Real symbol.  */
 	  const char *warning;	/* Warning (bfd_link_hash_warning only).  */
 	} i;
       /* bfd_link_hash_common.  */
       struct
 	{
 	  /* The linker needs to know three things about common
              symbols: the size, the alignment, and the section in
              which the symbol should be placed.  We store the size
              here, and we allocate a small structure to hold the
              section and the alignment.  The alignment is stored as a
              power of two.  We don't store all the information
              directly because we don't want to increase the size of
              the union; this structure is a major space user in the
              linker.  */
 	  bfd_size_type size;	/* Common symbol size.  */
 	  struct bfd_link_hash_common_entry
 	    {
 	      unsigned int alignment_power;	/* Alignment.  */
 	      asection *section;		/* Symbol section.  */
 	    } *p;
 	} c;
     } u;
 };

 /* This is the link hash table.  It is a derived class of
    bfd_hash_table.  */

 struct bfd_link_hash_table
 {
   /* The hash table itself.  */
   struct bfd_hash_table table;
   /* The back end which created this hash table.  This indicates the
      type of the entries in the hash table, which is sometimes
      important information when linking object files of different
      types together.  */
   const bfd_target *creator;
   /* A linked list of undefined and common symbols, linked through the
      next field in the bfd_link_hash_entry structure.  */
   struct bfd_link_hash_entry *undefs;
   /* Entries are added to the tail of the undefs list.  */
   struct bfd_link_hash_entry *undefs_tail;
 };

 /* Look up an entry in a link hash table.  If FOLLOW is true, this
    follows bfd_link_hash_indirect and bfd_link_hash_warning links to
    the real symbol.  */
 extern struct bfd_link_hash_entry *bfd_link_hash_lookup
   PARAMS ((struct bfd_link_hash_table *, const char *, boolean create,
 	   boolean copy, boolean follow));

 /* Look up an entry in the main linker hash table if the symbol might
    be wrapped.  This should only be used for references to an
    undefined symbol, not for definitions of a symbol.  */

 extern struct bfd_link_hash_entry *bfd_wrapped_link_hash_lookup
   PARAMS ((bfd *, struct bfd_link_info *, const char *, boolean, boolean,
 	   boolean));

 /* Traverse a link hash table.  */
 extern void bfd_link_hash_traverse
   PARAMS ((struct bfd_link_hash_table *,
 	   boolean (*) (struct bfd_link_hash_entry *, PTR),
 	   PTR));

 /* Add an entry to the undefs list.  */
 extern void bfd_link_add_undef
   PARAMS ((struct bfd_link_hash_table *, struct bfd_link_hash_entry *));

 /* This structure holds all the information needed to communicate
    between BFD and the linker when doing a link.  */

 struct bfd_link_info
 {
   /* Function callbacks.  */
   const struct bfd_link_callbacks *callbacks;
   /* true if BFD should generate a relocateable object file.  */
   boolean relocateable;
   /* true if BFD should generate a "task linked" object file,
      similar to relocatable but also with globals converted to statics. */
   boolean task_link;
   /* true if BFD should generate a shared object.  */
   boolean shared;
   /* true if BFD should pre-bind symbols in a shared object.  */
   boolean symbolic;
   /* true if shared objects should be linked directly, not shared.  */
   boolean static_link;
   /* true if the output file should be in a traditional format.  This
      is equivalent to the setting of the BFD_TRADITIONAL_FORMAT flag
      on the output file, but may be checked when reading the input
      files.  */
   boolean traditional_format;
   /* true if we want to produced optimized output files.  This might
      need much more time and therefore must be explicitly selected.  */
   boolean optimize;
   /* true if BFD should generate errors for undefined symbols
      even if generating a shared object.  */
   boolean no_undefined;
   /* Which symbols to strip.  */
   enum bfd_link_strip strip;
   /* Which local symbols to discard.  */
   enum bfd_link_discard discard;
   /* true if symbols should be retained in memory, false if they
      should be freed and reread.  */
   boolean keep_memory;
   /* The list of input BFD's involved in the link.  These are chained
      together via the link_next field.  */
   bfd *input_bfds;
   /* If a symbol should be created for each input BFD, this is section
      where those symbols should be placed.  It must be a section in
      the output BFD.  It may be NULL, in which case no such symbols
      will be created.  This is to support CREATE_OBJECT_SYMBOLS in the
      linker command language.  */
   asection *create_object_symbols_section;
   /* Hash table handled by BFD.  */
   struct bfd_link_hash_table *hash;
   /* Hash table of symbols to keep.  This is NULL unless strip is
      strip_some.  */
   struct bfd_hash_table *keep_hash;
   /* true if every symbol should be reported back via the notice
      callback.  */
   boolean notice_all;
   /* Hash table of symbols to report back via the notice callback.  If
      this is NULL, and notice_all is false, then no symbols are
      reported back.  */
   struct bfd_hash_table *notice_hash;
   /* Hash table of symbols which are being wrapped (the --wrap linker
      option).  If this is NULL, no symbols are being wrapped.  */
   struct bfd_hash_table *wrap_hash;
   /* If a base output file is wanted, then this points to it */
   PTR base_file;

   /* If non-zero, specifies that branches which are problematic for the
   MPC860 C0 (or earlier) should be checked for and modified.  It gives the
   number of bytes that should be checked at the end of each text page. */
   int mpc860c0;

   /* The function to call when the executable or shared object is
      loaded.  */
   const char *init_function;
   /* The function to call when the executable or shared object is
      unloaded.  */
   const char *fini_function;
 };

 /* This structures holds a set of callback functions.  These are
    called by the BFD linker routines.  The first argument to each
    callback function is the bfd_link_info structure being used.  Each
    function returns a boolean value.  If the function returns false,
    then the BFD function which called it will return with a failure
    indication.  */

 struct bfd_link_callbacks
 {
   /* A function which is called when an object is added from an
      archive.  ABFD is the archive element being added.  NAME is the
      name of the symbol which caused the archive element to be pulled
      in.  */
   boolean (*add_archive_element) PARAMS ((struct bfd_link_info *,
 					  bfd *abfd,
 					  const char *name));
   /* A function which is called when a symbol is found with multiple
      definitions.  NAME is the symbol which is defined multiple times.
      OBFD is the old BFD, OSEC is the old section, OVAL is the old
      value, NBFD is the new BFD, NSEC is the new section, and NVAL is
      the new value.  OBFD may be NULL.  OSEC and NSEC may be
      bfd_com_section or bfd_ind_section.  */
   boolean (*multiple_definition) PARAMS ((struct bfd_link_info *,
 					  const char *name,
 					  bfd *obfd,
 					  asection *osec,
 					  bfd_vma oval,
 					  bfd *nbfd,
 					  asection *nsec,
 					  bfd_vma nval));
   /* A function which is called when a common symbol is defined
      multiple times.  NAME is the symbol appearing multiple times.
      OBFD is the BFD of the existing symbol; it may be NULL if this is
      not known.  OTYPE is the type of the existing symbol, which may
      be bfd_link_hash_defined, bfd_link_hash_defweak,
      bfd_link_hash_common, or bfd_link_hash_indirect.  If OTYPE is
      bfd_link_hash_common, OSIZE is the size of the existing symbol.
      NBFD is the BFD of the new symbol.  NTYPE is the type of the new
      symbol, one of bfd_link_hash_defined, bfd_link_hash_common, or
      bfd_link_hash_indirect.  If NTYPE is bfd_link_hash_common, NSIZE
      is the size of the new symbol.  */
   boolean (*multiple_common) PARAMS ((struct bfd_link_info *,
 				      const char *name,
 				      bfd *obfd,
 				      enum bfd_link_hash_type otype,
 				      bfd_vma osize,
 				      bfd *nbfd,
 				      enum bfd_link_hash_type ntype,
 				      bfd_vma nsize));
   /* A function which is called to add a symbol to a set.  ENTRY is
      the link hash table entry for the set itself (e.g.,
      __CTOR_LIST__).  RELOC is the relocation to use for an entry in
      the set when generating a relocateable file, and is also used to
      get the size of the entry when generating an executable file.
      ABFD, SEC and VALUE identify the value to add to the set.  */
   boolean (*add_to_set) PARAMS ((struct bfd_link_info *,
 				 struct bfd_link_hash_entry *entry,
 				 bfd_reloc_code_real_type reloc,
 				 bfd *abfd, asection *sec, bfd_vma value));
   /* A function which is called when the name of a g++ constructor or
      destructor is found.  This is only called by some object file
      formats.  CONSTRUCTOR is true for a constructor, false for a
      destructor.  This will use BFD_RELOC_CTOR when generating a
      relocateable file.  NAME is the name of the symbol found.  ABFD,
      SECTION and VALUE are the value of the symbol.  */
   boolean (*constructor) PARAMS ((struct bfd_link_info *,
 				  boolean constructor,
 				  const char *name, bfd *abfd, asection *sec,
 				  bfd_vma value));
   /* A function which is called to issue a linker warning.  For
      example, this is called when there is a reference to a warning
      symbol.  WARNING is the warning to be issued.  SYMBOL is the name
      of the symbol which triggered the warning; it may be NULL if
      there is none.  ABFD, SECTION and ADDRESS identify the location
      which trigerred the warning; either ABFD or SECTION or both may
      be NULL if the location is not known.  */
   boolean (*warning) PARAMS ((struct bfd_link_info *,
 			      const char *warning, const char *symbol,
 			      bfd *abfd, asection *section,
 			      bfd_vma address));
   /* A function which is called when a relocation is attempted against
      an undefined symbol.  NAME is the symbol which is undefined.
      ABFD, SECTION and ADDRESS identify the location from which the
      reference is made.  In some cases SECTION may be NULL.  */
   boolean (*undefined_symbol) PARAMS ((struct bfd_link_info *,
 				       const char *name, bfd *abfd,
 				       asection *section, bfd_vma address));
   /* A function which is called when a reloc overflow occurs.  NAME is
      the name of the symbol or section the reloc is against,
      RELOC_NAME is the name of the relocation, and ADDEND is any
      addend that is used.  ABFD, SECTION and ADDRESS identify the
      location at which the overflow occurs; if this is the result of a
      bfd_section_reloc_link_order or bfd_symbol_reloc_link_order, then
      ABFD will be NULL.  */
   boolean (*reloc_overflow) PARAMS ((struct bfd_link_info *,
 				     const char *name,
 				     const char *reloc_name, bfd_vma addend,
 				     bfd *abfd, asection *section,
 				     bfd_vma address));
   /* A function which is called when a dangerous reloc is performed.
      The canonical example is an a29k IHCONST reloc which does not
      follow an IHIHALF reloc.  MESSAGE is an appropriate message.
      ABFD, SECTION and ADDRESS identify the location at which the
      problem occurred; if this is the result of a
      bfd_section_reloc_link_order or bfd_symbol_reloc_link_order, then
      ABFD will be NULL.  */
   boolean (*reloc_dangerous) PARAMS ((struct bfd_link_info *,
 				      const char *message,
 				      bfd *abfd, asection *section,
 				      bfd_vma address));
   /* A function which is called when a reloc is found to be attached
      to a symbol which is not being written out.  NAME is the name of
      the symbol.  ABFD, SECTION and ADDRESS identify the location of
      the reloc; if this is the result of a
      bfd_section_reloc_link_order or bfd_symbol_reloc_link_order, then
      ABFD will be NULL.  */
   boolean (*unattached_reloc) PARAMS ((struct bfd_link_info *,
 				       const char *name,
 				       bfd *abfd, asection *section,
 				       bfd_vma address));
   /* A function which is called when a symbol in notice_hash is
      defined or referenced.  NAME is the symbol.  ABFD, SECTION and
      ADDRESS are the value of the symbol.  If SECTION is
      bfd_und_section, this is a reference.  */
   boolean (*notice) PARAMS ((struct bfd_link_info *, const char *name,
 			     bfd *abfd, asection *section, bfd_vma address));
 };

 /* The linker builds link_order structures which tell the code how to
    include input data in the output file.  */

 /* These are the types of link_order structures.  */

 enum bfd_link_order_type
 {
   bfd_undefined_link_order,	/* Undefined.  */
   bfd_indirect_link_order,	/* Built from a section.  */
   bfd_fill_link_order,		/* Fill with a 16 bit constant.  */
   bfd_data_link_order,		/* Set to explicit data.  */
   bfd_section_reloc_link_order,	/* Relocate against a section.  */
   bfd_symbol_reloc_link_order	/* Relocate against a symbol.  */
 };

 /* This is the link_order structure itself.  These form a chain
    attached to the section whose contents they are describing.  */

 struct bfd_link_order
 {
   /* Next link_order in chain.  */
   struct bfd_link_order *next;
   /* Type of link_order.  */
   enum bfd_link_order_type type;
   /* Offset within output section.  */
   bfd_vma offset;
   /* Size within output section.  */
   bfd_size_type size;
   /* Type specific information.  */
   union
     {
       struct
 	{
 	  /* Section to include.  If this is used, then
 	     section->output_section must be the section the
 	     link_order is attached to, section->output_offset must
 	     equal the link_order offset field, and section->_raw_size
 	     must equal the link_order size field.  Maybe these
 	     restrictions should be relaxed someday.  */
 	  asection *section;
 	} indirect;
       struct
 	{
 	  /* Value to fill with.  */
 	  unsigned int value;
 	} fill;
       struct
 	{
 	  /* Data to put into file.  The size field gives the number
 	     of bytes which this field points to.  */
 	  bfd_byte *contents;
 	} data;
       struct
 	{
 	  /* Description of reloc to generate.  Used for
 	     bfd_section_reloc_link_order and
 	     bfd_symbol_reloc_link_order.  */
 	  struct bfd_link_order_reloc *p;
 	} reloc;
     } u;
 };

 /* A linker order of type bfd_section_reloc_link_order or
    bfd_symbol_reloc_link_order means to create a reloc against a
    section or symbol, respectively.  This is used to implement -Ur to
    generate relocs for the constructor tables.  The
    bfd_link_order_reloc structure describes the reloc that BFD should
    create.  It is similar to a arelent, but I didn't use arelent
    because the linker does not know anything about most symbols, and
    any asymbol structure it creates will be partially meaningless.
    This information could logically be in the bfd_link_order struct,
    but I didn't want to waste the space since these types of relocs
    are relatively rare.  */

 struct bfd_link_order_reloc
 {
   /* Reloc type.  */
   bfd_reloc_code_real_type reloc;

   union
     {
       /* For type bfd_section_reloc_link_order, this is the section
 	 the reloc should be against.  This must be a section in the
 	 output BFD, not any of the input BFDs.  */
       asection *section;
       /* For type bfd_symbol_reloc_link_order, this is the name of the
 	 symbol the reloc should be against.  */
       const char *name;
     } u;

   /* Addend to use.  The object file should contain zero.  The BFD
      backend is responsible for filling in the contents of the object
      file correctly.  For some object file formats (e.g., COFF) the
      addend must be stored into in the object file, and for some
      (e.g., SPARC a.out) it is kept in the reloc.  */
   bfd_vma addend;
 };

 /* Allocate a new link_order for a section.  */
 extern struct bfd_link_order *bfd_new_link_order PARAMS ((bfd *, asection *));

 /* These structures are used to describe version information for the
    ELF linker.  These structures could be manipulated entirely inside
    BFD, but it would be a pain.  Instead, the regular linker sets up
    these structures, and then passes them into BFD.  */

 /* Regular expressions for a version.  */

 struct bfd_elf_version_expr
 {
   /* Next regular expression for this version.  */
   struct bfd_elf_version_expr *next;
   /* Regular expression.  */
   const char *pattern;
   /* Matching function.  */
   int (*match) PARAMS((struct bfd_elf_version_expr *, const char *));
 };

 /* Version dependencies.  */

 struct bfd_elf_version_deps
 {
   /* Next dependency for this version.  */
   struct bfd_elf_version_deps *next;
   /* The version which this version depends upon.  */
   struct bfd_elf_version_tree *version_needed;
 };

 /* A node in the version tree.  */

 struct bfd_elf_version_tree
 {
   /* Next version.  */
   struct bfd_elf_version_tree *next;
   /* Name of this version.  */
   const char *name;
   /* Version number.  */
   unsigned int vernum;
   /* Regular expressions for global symbols in this version.  */
   struct bfd_elf_version_expr *globals;
   /* Regular expressions for local symbols in this version.  */
   struct bfd_elf_version_expr *locals;
   /* List of versions which this version depends upon.  */
   struct bfd_elf_version_deps *deps;
   /* Index of the version name.  This is used within BFD.  */
   unsigned int name_indx;
   /* Whether this version tree was used.  This is used within BFD.  */
   int used;
 };

 #endif
	/* bfdlink.h -- header file for BFD link routines
	Copyright 1993, 94, 95, 96, 97, 1999 Free Software Foundation, Inc.
	Written by Steve Chamberlain and Ian Lance Taylor, 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 BFDLINK_H
	#define BFDLINK_H

	/* Which symbols to strip during a link. */
	enum bfd_link_strip
	{
	strip_none, /* Don't strip any symbols. */
	strip_debugger, /* Strip debugging symbols. */
	strip_some, /* keep_hash is the list of symbols to keep. */
	strip_all /* Strip all symbols. */
	};

	/* Which local symbols to discard during a link. This is irrelevant
	if strip_all is used. */
	enum bfd_link_discard
	{
	discard_none, /* Don't discard any locals. */
	discard_l, /* Discard local temporary symbols. */
	discard_all /* Discard all locals. */
	};

	/* These are the possible types of an entry in the BFD link hash
	table. */

	enum bfd_link_hash_type
	{
	bfd_link_hash_new, /* Symbol is new. */
	bfd_link_hash_undefined, /* Symbol seen before, but undefined. */
	bfd_link_hash_undefweak, /* Symbol is weak and undefined. */
	bfd_link_hash_defined, /* Symbol is defined. */
	bfd_link_hash_defweak, /* Symbol is weak and defined. */
	bfd_link_hash_common, /* Symbol is common. */
	bfd_link_hash_indirect, /* Symbol is an indirect link. */
	bfd_link_hash_warning /* Like indirect, but warn if referenced. */
	};

	/* The linking routines use a hash table which uses this structure for
	its elements. */

	struct bfd_link_hash_entry
	{
	/* Base hash table entry structure. */
	struct bfd_hash_entry root;
	/* Type of this entry. */
	enum bfd_link_hash_type type;

	/* Undefined and common symbols are kept in a linked list through
	this field. This field is not in the union because that would
	force us to remove entries from the list when we changed their
	type, which would force the list to be doubly linked, which would
	waste more memory. When an undefined or common symbol is
	created, it should be added to this list, the head of which is in
	the link hash table itself. As symbols are defined, they need
	not be removed from the list; anything which reads the list must
	doublecheck the symbol type.

	Weak symbols are not kept on this list.

	Defined and defweak symbols use this field as a reference marker.
	If the field is not NULL, or this structure is the tail of the
	undefined symbol list, the symbol has been referenced. If the
	symbol is undefined and becomes defined, this field will
	automatically be non-NULL since the symbol will have been on the
	undefined symbol list. */
	struct bfd_link_hash_entry *next;
	/* A union of information depending upon the type. */
	union
	{
	/* Nothing is kept for bfd_hash_new. */
	/* bfd_link_hash_undefined, bfd_link_hash_undefweak. */
	struct
	{
	bfd abfd; / BFD symbol was found in. */
	} undef;
	/* bfd_link_hash_defined, bfd_link_hash_defweak. */
	struct
	{
	bfd_vma value; /* Symbol value. */
	asection section; / Symbol section. */
	} def;
	/* bfd_link_hash_indirect, bfd_link_hash_warning. */
	struct
	{
	struct bfd_link_hash_entry link; / Real symbol. */
	const char warning; / Warning (bfd_link_hash_warning only). */
	} i;
	/* bfd_link_hash_common. */
	struct
	{
	/* The linker needs to know three things about common
	symbols: the size, the alignment, and the section in
	which the symbol should be placed. We store the size
	here, and we allocate a small structure to hold the
	section and the alignment. The alignment is stored as a
	power of two. We don't store all the information
	directly because we don't want to increase the size of
	the union; this structure is a major space user in the
	linker. */
	bfd_size_type size; /* Common symbol size. */
	struct bfd_link_hash_common_entry
	{
	unsigned int alignment_power; /* Alignment. */
	asection section; / Symbol section. */
	} *p;
	} c;
	} u;
	};

	/* This is the link hash table. It is a derived class of
	bfd_hash_table. */

	struct bfd_link_hash_table
	{
	/* The hash table itself. */
	struct bfd_hash_table table;
	/* The back end which created this hash table. This indicates the
	type of the entries in the hash table, which is sometimes
	important information when linking object files of different
	types together. */
	const bfd_target *creator;
	/* A linked list of undefined and common symbols, linked through the
	next field in the bfd_link_hash_entry structure. */
	struct bfd_link_hash_entry *undefs;
	/* Entries are added to the tail of the undefs list. */
	struct bfd_link_hash_entry *undefs_tail;
	};

	/* Look up an entry in a link hash table. If FOLLOW is true, this
	follows bfd_link_hash_indirect and bfd_link_hash_warning links to
	the real symbol. */
	extern struct bfd_link_hash_entry *bfd_link_hash_lookup
	PARAMS ((struct bfd_link_hash_table , const char , boolean create,
	boolean copy, boolean follow));

	/* Look up an entry in the main linker hash table if the symbol might
	be wrapped. This should only be used for references to an
	undefined symbol, not for definitions of a symbol. */

	extern struct bfd_link_hash_entry *bfd_wrapped_link_hash_lookup
	PARAMS ((bfd , struct bfd_link_info , const char *, boolean, boolean,
	boolean));

	/* Traverse a link hash table. */
	extern void bfd_link_hash_traverse
	PARAMS ((struct bfd_link_hash_table *,
	boolean () (struct bfd_link_hash_entry , PTR),
	PTR));

	/* Add an entry to the undefs list. */
	extern void bfd_link_add_undef
	PARAMS ((struct bfd_link_hash_table , struct bfd_link_hash_entry ));

	/* This structure holds all the information needed to communicate
	between BFD and the linker when doing a link. */

	struct bfd_link_info
	{
	/* Function callbacks. */
	const struct bfd_link_callbacks *callbacks;
	/* true if BFD should generate a relocateable object file. */
	boolean relocateable;
	/* true if BFD should generate a "task linked" object file,
	similar to relocatable but also with globals converted to statics. */
	boolean task_link;
	/* true if BFD should generate a shared object. */
	boolean shared;
	/* true if BFD should pre-bind symbols in a shared object. */
	boolean symbolic;
	/* true if shared objects should be linked directly, not shared. */
	boolean static_link;
	/* true if the output file should be in a traditional format. This
	is equivalent to the setting of the BFD_TRADITIONAL_FORMAT flag
	on the output file, but may be checked when reading the input
	files. */
	boolean traditional_format;
	/* true if we want to produced optimized output files. This might
	need much more time and therefore must be explicitly selected. */
	boolean optimize;
	/* true if BFD should generate errors for undefined symbols
	even if generating a shared object. */
	boolean no_undefined;
	/* Which symbols to strip. */
	enum bfd_link_strip strip;
	/* Which local symbols to discard. */
	enum bfd_link_discard discard;
	/* true if symbols should be retained in memory, false if they
	should be freed and reread. */
	boolean keep_memory;
	/* The list of input BFD's involved in the link. These are chained
	together via the link_next field. */
	bfd *input_bfds;
	/* If a symbol should be created for each input BFD, this is section
	where those symbols should be placed. It must be a section in
	the output BFD. It may be NULL, in which case no such symbols
	will be created. This is to support CREATE_OBJECT_SYMBOLS in the
	linker command language. */
	asection *create_object_symbols_section;
	/* Hash table handled by BFD. */
	struct bfd_link_hash_table *hash;
	/* Hash table of symbols to keep. This is NULL unless strip is
	strip_some. */
	struct bfd_hash_table *keep_hash;
	/* true if every symbol should be reported back via the notice
	callback. */
	boolean notice_all;
	/* Hash table of symbols to report back via the notice callback. If
	this is NULL, and notice_all is false, then no symbols are
	reported back. */
	struct bfd_hash_table *notice_hash;
	/* Hash table of symbols which are being wrapped (the --wrap linker
	option). If this is NULL, no symbols are being wrapped. */
	struct bfd_hash_table *wrap_hash;
	/* If a base output file is wanted, then this points to it */
	PTR base_file;

	/* If non-zero, specifies that branches which are problematic for the
	MPC860 C0 (or earlier) should be checked for and modified. It gives the
	number of bytes that should be checked at the end of each text page. */
	int mpc860c0;

	/* The function to call when the executable or shared object is
	loaded. */
	const char *init_function;
	/* The function to call when the executable or shared object is
	unloaded. */
	const char *fini_function;
	};

	/* This structures holds a set of callback functions. These are
	called by the BFD linker routines. The first argument to each
	callback function is the bfd_link_info structure being used. Each
	function returns a boolean value. If the function returns false,
	then the BFD function which called it will return with a failure
	indication. */

	struct bfd_link_callbacks
	{
	/* A function which is called when an object is added from an
	archive. ABFD is the archive element being added. NAME is the
	name of the symbol which caused the archive element to be pulled
	in. */
	boolean (add_archive_element) PARAMS ((struct bfd_link_info ,
	bfd *abfd,
	const char *name));
	/* A function which is called when a symbol is found with multiple
	definitions. NAME is the symbol which is defined multiple times.
	OBFD is the old BFD, OSEC is the old section, OVAL is the old
	value, NBFD is the new BFD, NSEC is the new section, and NVAL is
	the new value. OBFD may be NULL. OSEC and NSEC may be
	bfd_com_section or bfd_ind_section. */
	boolean (multiple_definition) PARAMS ((struct bfd_link_info ,
	const char *name,
	bfd *obfd,
	asection *osec,
	bfd_vma oval,
	bfd *nbfd,
	asection *nsec,
	bfd_vma nval));
	/* A function which is called when a common symbol is defined
	multiple times. NAME is the symbol appearing multiple times.
	OBFD is the BFD of the existing symbol; it may be NULL if this is
	not known. OTYPE is the type of the existing symbol, which may
	be bfd_link_hash_defined, bfd_link_hash_defweak,
	bfd_link_hash_common, or bfd_link_hash_indirect. If OTYPE is
	bfd_link_hash_common, OSIZE is the size of the existing symbol.
	NBFD is the BFD of the new symbol. NTYPE is the type of the new
	symbol, one of bfd_link_hash_defined, bfd_link_hash_common, or
	bfd_link_hash_indirect. If NTYPE is bfd_link_hash_common, NSIZE
	is the size of the new symbol. */
	boolean (multiple_common) PARAMS ((struct bfd_link_info ,
	const char *name,
	bfd *obfd,
	enum bfd_link_hash_type otype,
	bfd_vma osize,
	bfd *nbfd,
	enum bfd_link_hash_type ntype,
	bfd_vma nsize));
	/* A function which is called to add a symbol to a set. ENTRY is
	the link hash table entry for the set itself (e.g.,
	__CTOR_LIST__). RELOC is the relocation to use for an entry in
	the set when generating a relocateable file, and is also used to
	get the size of the entry when generating an executable file.
	ABFD, SEC and VALUE identify the value to add to the set. */
	boolean (add_to_set) PARAMS ((struct bfd_link_info ,
	struct bfd_link_hash_entry *entry,
	bfd_reloc_code_real_type reloc,
	bfd abfd, asection sec, bfd_vma value));
	/* A function which is called when the name of a g++ constructor or
	destructor is found. This is only called by some object file
	formats. CONSTRUCTOR is true for a constructor, false for a
	destructor. This will use BFD_RELOC_CTOR when generating a
	relocateable file. NAME is the name of the symbol found. ABFD,
	SECTION and VALUE are the value of the symbol. */
	boolean (constructor) PARAMS ((struct bfd_link_info ,
	boolean constructor,
	const char name, bfd abfd, asection *sec,
	bfd_vma value));
	/* A function which is called to issue a linker warning. For
	example, this is called when there is a reference to a warning
	symbol. WARNING is the warning to be issued. SYMBOL is the name
	of the symbol which triggered the warning; it may be NULL if
	there is none. ABFD, SECTION and ADDRESS identify the location
	which trigerred the warning; either ABFD or SECTION or both may
	be NULL if the location is not known. */
	boolean (warning) PARAMS ((struct bfd_link_info ,
	const char warning, const char symbol,
	bfd abfd, asection section,
	bfd_vma address));
	/* A function which is called when a relocation is attempted against
	an undefined symbol. NAME is the symbol which is undefined.
	ABFD, SECTION and ADDRESS identify the location from which the
	reference is made. In some cases SECTION may be NULL. */
	boolean (undefined_symbol) PARAMS ((struct bfd_link_info ,
	const char name, bfd abfd,
	asection *section, bfd_vma address));
	/* A function which is called when a reloc overflow occurs. NAME is
	the name of the symbol or section the reloc is against,
	RELOC_NAME is the name of the relocation, and ADDEND is any
	addend that is used. ABFD, SECTION and ADDRESS identify the
	location at which the overflow occurs; if this is the result of a
	bfd_section_reloc_link_order or bfd_symbol_reloc_link_order, then
	ABFD will be NULL. */
	boolean (reloc_overflow) PARAMS ((struct bfd_link_info ,
	const char *name,
	const char *reloc_name, bfd_vma addend,
	bfd abfd, asection section,
	bfd_vma address));
	/* A function which is called when a dangerous reloc is performed.
	The canonical example is an a29k IHCONST reloc which does not
	follow an IHIHALF reloc. MESSAGE is an appropriate message.
	ABFD, SECTION and ADDRESS identify the location at which the
	problem occurred; if this is the result of a
	bfd_section_reloc_link_order or bfd_symbol_reloc_link_order, then
	ABFD will be NULL. */
	boolean (reloc_dangerous) PARAMS ((struct bfd_link_info ,
	const char *message,
	bfd abfd, asection section,
	bfd_vma address));
	/* A function which is called when a reloc is found to be attached
	to a symbol which is not being written out. NAME is the name of
	the symbol. ABFD, SECTION and ADDRESS identify the location of
	the reloc; if this is the result of a
	bfd_section_reloc_link_order or bfd_symbol_reloc_link_order, then
	ABFD will be NULL. */
	boolean (unattached_reloc) PARAMS ((struct bfd_link_info ,
	const char *name,
	bfd abfd, asection section,
	bfd_vma address));
	/* A function which is called when a symbol in notice_hash is
	defined or referenced. NAME is the symbol. ABFD, SECTION and
	ADDRESS are the value of the symbol. If SECTION is
	bfd_und_section, this is a reference. */
	boolean (notice) PARAMS ((struct bfd_link_info , const char *name,
	bfd abfd, asection section, bfd_vma address));
	};

	/* The linker builds link_order structures which tell the code how to
	include input data in the output file. */

	/* These are the types of link_order structures. */

	enum bfd_link_order_type
	{
	bfd_undefined_link_order, /* Undefined. */
	bfd_indirect_link_order, /* Built from a section. */
	bfd_fill_link_order, /* Fill with a 16 bit constant. */
	bfd_data_link_order, /* Set to explicit data. */
	bfd_section_reloc_link_order, /* Relocate against a section. */
	bfd_symbol_reloc_link_order /* Relocate against a symbol. */
	};

	/* This is the link_order structure itself. These form a chain
	attached to the section whose contents they are describing. */

	struct bfd_link_order
	{
	/* Next link_order in chain. */
	struct bfd_link_order *next;
	/* Type of link_order. */
	enum bfd_link_order_type type;
	/* Offset within output section. */
	bfd_vma offset;
	/* Size within output section. */
	bfd_size_type size;
	/* Type specific information. */
	union
	{
	struct
	{
	/* Section to include. If this is used, then
	section->output_section must be the section the
	link_order is attached to, section->output_offset must
	equal the link_order offset field, and section->_raw_size
	must equal the link_order size field. Maybe these
	restrictions should be relaxed someday. */
	asection *section;
	} indirect;
	struct
	{
	/* Value to fill with. */
	unsigned int value;
	} fill;
	struct
	{
	/* Data to put into file. The size field gives the number
	of bytes which this field points to. */
	bfd_byte *contents;
	} data;
	struct
	{
	/* Description of reloc to generate. Used for
	bfd_section_reloc_link_order and
	bfd_symbol_reloc_link_order. */
	struct bfd_link_order_reloc *p;
	} reloc;
	} u;
	};

	/* A linker order of type bfd_section_reloc_link_order or
	bfd_symbol_reloc_link_order means to create a reloc against a
	section or symbol, respectively. This is used to implement -Ur to
	generate relocs for the constructor tables. The
	bfd_link_order_reloc structure describes the reloc that BFD should
	create. It is similar to a arelent, but I didn't use arelent
	because the linker does not know anything about most symbols, and
	any asymbol structure it creates will be partially meaningless.
	This information could logically be in the bfd_link_order struct,
	but I didn't want to waste the space since these types of relocs
	are relatively rare. */

	struct bfd_link_order_reloc
	{
	/* Reloc type. */
	bfd_reloc_code_real_type reloc;

	union
	{
	/* For type bfd_section_reloc_link_order, this is the section
	the reloc should be against. This must be a section in the
	output BFD, not any of the input BFDs. */
	asection *section;
	/* For type bfd_symbol_reloc_link_order, this is the name of the
	symbol the reloc should be against. */
	const char *name;
	} u;

	/* Addend to use. The object file should contain zero. The BFD
	backend is responsible for filling in the contents of the object
	file correctly. For some object file formats (e.g., COFF) the
	addend must be stored into in the object file, and for some
	(e.g., SPARC a.out) it is kept in the reloc. */
	bfd_vma addend;
	};

	/* Allocate a new link_order for a section. */
	extern struct bfd_link_order bfd_new_link_order PARAMS ((bfd , asection *));

	/* These structures are used to describe version information for the
	ELF linker. These structures could be manipulated entirely inside
	BFD, but it would be a pain. Instead, the regular linker sets up
	these structures, and then passes them into BFD. */

	/* Regular expressions for a version. */

	struct bfd_elf_version_expr
	{
	/* Next regular expression for this version. */
	struct bfd_elf_version_expr *next;
	/* Regular expression. */
	const char *pattern;
	/* Matching function. */
	int (match) PARAMS((struct bfd_elf_version_expr , const char *));
	};

	/* Version dependencies. */

	struct bfd_elf_version_deps
	{
	/* Next dependency for this version. */
	struct bfd_elf_version_deps *next;
	/* The version which this version depends upon. */
	struct bfd_elf_version_tree *version_needed;
	};

	/* A node in the version tree. */

	struct bfd_elf_version_tree
	{
	/* Next version. */
	struct bfd_elf_version_tree *next;
	/* Name of this version. */
	const char *name;
	/* Version number. */
	unsigned int vernum;
	/* Regular expressions for global symbols in this version. */
	struct bfd_elf_version_expr *globals;
	/* Regular expressions for local symbols in this version. */
	struct bfd_elf_version_expr *locals;
	/* List of versions which this version depends upon. */
	struct bfd_elf_version_deps *deps;
	/* Index of the version name. This is used within BFD. */
	unsigned int name_indx;
	/* Whether this version tree was used. This is used within BFD. */
	int used;
	};

	#endif