binutils-gdb/bfd/bfd.c

/* Generic BFD library interface and support routines.
   Copyright (C) 1990-1991 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., 675 Mass Ave, Cambridge, MA 02139, USA.  */

/* $Id$ */

/*
SECTION
	<<typedef bfd>>

DESCRIPTION
	A BFD is has type <<bfd>>; objects of this type are the
	cornerstone of any application using <<libbfd>>. References
	though the BFD and to data in the BFD give the entire BFD
	functionality.

	Here is the struct used to define the type <<bfd>>.  This
	contains he major data about the file, and contains pointers
	to the rest of the data.

.struct _bfd 
.{
	The filename the application opened the BFD with.

.  CONST char *filename;                

	A pointer to the target jump table.

.  struct bfd_target *xvec;

	To avoid dragging too many header files into every file that
	includes @file{bfd.h}, IOSTREAM has been declared as a "char
	*", and MTIME as a "long".  Their correct types, to which they
	are cast when used, are "FILE *" and "time_t".    The iostream
	is the result of an fopen on the filename. 

.  char *iostream;

Is the file being cached @xref{File Caching}.

.  boolean cacheable;

	Marks whether there was a default target specified when the
	BFD was opened. This is used to select what matching algorithm
	to use to chose the back end.

.  boolean target_defaulted;

	The caching routines use these to maintain a
	least-recently-used list of BFDs (@pxref{File Caching}).

.  struct _bfd *lru_prev, *lru_next;

	When a file is closed by the caching routines, BFD retains
	state information on the file here:

.  file_ptr where;              

	and here:

.  boolean opened_once;

.  boolean mtime_set;

File modified time 

.  long mtime;          

	Reserved for an unimplemented file locking extension.

.  int ifd;

	The format which belongs to the BFD.

.  bfd_format format;

	The direction the BFD was opened with

.  enum bfd_direction {no_direction = 0,
.                       read_direction = 1,
.                       write_direction = 2,
.                       both_direction = 3} direction;

	Format_specific flags

.  flagword flags;              

	Currently my_archive is tested before adding origin to
	anything. I believe that this can become always an add of
	origin, with origin set to 0 for non archive files.  

.  file_ptr origin;             

	Remember when output has begun, to stop strange things happening.

.  boolean output_has_begun;

	Pointer to linked list of sections

.  struct sec  *sections;

	The number of sections 

.  unsigned int section_count;

	Stuff only useful for object files: 
	The start address.

.  bfd_vma start_address;

	Used for input and output

.  unsigned int symcount;

	Symbol table for output BFD

.  struct symbol_cache_entry  **outsymbols;             

	Pointer to structure which contains architecture information

.  struct bfd_arch_info *arch_info;

	Stuff only useful for archives:

.  PTR arelt_data;              
.  struct _bfd *my_archive;     
.  struct _bfd *next;           
.  struct _bfd *archive_head;   
.  boolean has_armap;           

	Used by the back end to hold private data.

.  PTR tdata;

	Used by the application to hold private data

.  PTR usrdata;

	Where all the allocated stuff under this BFD goes
	(@pxref{Memory Usage}).

.  struct obstack memory;
.};

*/
#include "bfd.h"
#include "sysdep.h"
#include "libbfd.h"

#undef strerror
extern char *strerror();


CONST short _bfd_host_big_endian = 0x0100;
        /* Accessing the above as (*(char*)&_bfd_host_big_endian), will
           return 1 if the host is big-endian, 0 otherwise.
           (assuming that a short is two bytes long!!!  FIXME)
           (See HOST_IS_BIG_ENDIAN_P in bfd.h.)  */

/** Error handling
    o - Most functions return nonzero on success (check doc for
        precise semantics); 0 or NULL on error.
    o - Internal errors are documented by the value of bfd_error.
        If that is system_call_error then check errno.
    o - The easiest way to report this to the user is to use bfd_perror.
*/

bfd_ec bfd_error = no_error;

char *bfd_errmsgs[] = { "No error",
                        "System call error",
                        "Invalid target",
                        "File in wrong format",
                        "Invalid operation",
                        "Memory exhausted",
                        "No symbols",
                        "No relocation info",
                        "No more archived files",
                        "Malformed archive",
                        "Symbol not found",
                        "File format not recognized",
                        "File format is ambiguous",
                        "Section has no contents",
                        "Nonrepresentable section on output",
			"Symbol needs debug section which does not exist",
                        "#<Invalid error code>"
                       };

static 
void 
DEFUN(bfd_nonrepresentable_section,(abfd, name),
         CONST  bfd * CONST abfd AND
         CONST  char * CONST name)
{
  printf("bfd error writing file %s, format %s can't represent section %s\n",
         abfd->filename, 
         abfd->xvec->name,
         name);
  exit(1);
}

bfd_error_vector_type bfd_error_vector = 
  {
  bfd_nonrepresentable_section 
  };

char *
bfd_errmsg (error_tag)
     bfd_ec error_tag;
{
#ifndef errno
  extern int errno;
#endif
  if (error_tag == system_call_error)
    return strerror (errno);

  if ((((int)error_tag <(int) no_error) ||
       ((int)error_tag > (int)invalid_error_code)))
    error_tag = invalid_error_code;/* sanity check */

  return bfd_errmsgs [(int)error_tag];
}


void bfd_default_error_trap(error_tag)
bfd_ec error_tag;
{
  printf("bfd assert fail (%s)\n", bfd_errmsg(error_tag));
}

void (*bfd_error_trap)() = bfd_default_error_trap;
void (*bfd_error_nonrepresentabltrap)() = bfd_default_error_trap;

void
DEFUN(bfd_perror,(message),
      CONST char *message)
{
  if (bfd_error == system_call_error)
    perror((char *)message);            /* must be system error then... */
  else {
    if (message == NULL || *message == '\0')
      fprintf (stderr, "%s\n", bfd_errmsg (bfd_error));
    else
      fprintf (stderr, "%s: %s\n", message, bfd_errmsg (bfd_error));
  }
}

 
/** Symbols */

/* returns the number of octets of storage required */

unsigned int
get_reloc_upper_bound (abfd, asect)
     bfd *abfd;
     sec_ptr asect;
{
  if (abfd->format != bfd_object) {
    bfd_error = invalid_operation;
    return 0;
  }

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

unsigned int
DEFUN(bfd_canonicalize_reloc,(abfd, asect, location, symbols),
     bfd *abfd AND
     sec_ptr asect AND
     arelent **location AND
     asymbol **symbols)
{
    if (abfd->format != bfd_object) {
	bfd_error = invalid_operation;
	return 0;
    }
    return BFD_SEND (abfd, _bfd_canonicalize_reloc, (abfd, asect, location, symbols));
}


boolean
bfd_set_file_flags (abfd, flags)
     bfd *abfd;
     flagword flags;
{
  if (abfd->format != bfd_object) {
    bfd_error = wrong_format;
    return false;
  }

  if (bfd_read_p (abfd)) {
    bfd_error = invalid_operation;
    return false;
  }

  if ((flags & bfd_applicable_file_flags (abfd)) != flags) {
    bfd_error = invalid_operation;
    return false;
  }

  bfd_get_file_flags (abfd) = flags;
return true;
}


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

void
bfd_assert(file, line)
char *file;
int line;
{
  printf("bfd assertion fail %s:%d\n",file,line);
}


/*
FUNCTION
	bfd_set_start_address

DESCRIPTION

	Marks the entry point of an output BFD.

RETURNS
	Returns <<true>> on success, <<false>> otherwise.

SYNOPSIS
 	boolean bfd_set_start_address(bfd *, bfd_vma);
*/

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


/*
FUNCTION
	bfd_get_mtime

DESCRIPTION
	Return cached file modification time (e.g. as read from
	archive header for archive members, or from file system if we
	have been called before); else determine modify time, cache
	it, and return it.  

SYNOPSIS
	long bfd_get_mtime(bfd *);
*/

long
bfd_get_mtime (abfd)
     bfd *abfd;
{
  FILE *fp;
  struct stat buf;

  if (abfd->mtime_set)
    return abfd->mtime;

  fp = bfd_cache_lookup (abfd);
  if (0 != fstat (fileno (fp), &buf))
    return 0;

  abfd->mtime_set = true;
  abfd->mtime = buf.st_mtime;
  return abfd->mtime;
}

/*
FUNCTION
	stuff

DESCRIPTION
	stuff which should be documented

.#define bfd_sizeof_headers(abfd, reloc) \
.     BFD_SEND (abfd, _bfd_sizeof_headers, (abfd, reloc))
.
.#define bfd_find_nearest_line(abfd, section, symbols, offset, filename_ptr, func, line_ptr) \
.     BFD_SEND (abfd, _bfd_find_nearest_line,  (abfd, section, symbols, offset, filename_ptr, func, line_ptr))
.
.#define bfd_debug_info_start(abfd) \
.        BFD_SEND (abfd, _bfd_debug_info_start, (abfd))
.
.#define bfd_debug_info_end(abfd) \
.        BFD_SEND (abfd, _bfd_debug_info_end, (abfd))
.
.#define bfd_debug_info_accumulate(abfd, section) \
.        BFD_SEND (abfd, _bfd_debug_info_accumulate, (abfd, section))
.
.#define bfd_stat_arch_elt(abfd, stat) \
.        BFD_SEND (abfd, _bfd_stat_arch_elt,(abfd, stat))
.
.#define bfd_coff_swap_aux_in(a,e,t,c,i) \
.        BFD_SEND (a, _bfd_coff_swap_aux_in, (a,e,t,c,i))
.
.#define bfd_coff_swap_sym_in(a,e,i) \
.        BFD_SEND (a, _bfd_coff_swap_sym_in, (a,e,i))
.
.#define bfd_coff_swap_lineno_in(a,e,i) \
.        BFD_SEND ( a, _bfd_coff_swap_lineno_in, (a,e,i))
.
.#define bfd_set_arch_mach(abfd, arch, mach)\
.        BFD_SEND ( abfd, _bfd_set_arch_mach, (abfd, arch, mach))
.
.#define bfd_coff_swap_reloc_out(abfd, i, o) \
.        BFD_SEND (abfd, _bfd_coff_swap_reloc_out, (abfd, i, o))
.
.#define bfd_coff_swap_lineno_out(abfd, i, o) \
.        BFD_SEND (abfd, _bfd_coff_swap_lineno_out, (abfd, i, o))
.
.#define bfd_coff_swap_aux_out(abfd, i, t,c,o) \
.        BFD_SEND (abfd, _bfd_coff_swap_aux_out, (abfd, i,t,c, o))
.
.#define bfd_coff_swap_sym_out(abfd, i,o) \
.        BFD_SEND (abfd, _bfd_coff_swap_sym_out, (abfd, i, o))
.
.#define bfd_coff_swap_scnhdr_out(abfd, i,o) \
.        BFD_SEND (abfd, _bfd_coff_swap_scnhdr_out, (abfd, i, o))
.
.#define bfd_coff_swap_filehdr_out(abfd, i,o) \
.        BFD_SEND (abfd, _bfd_coff_swap_filehdr_out, (abfd, i, o))
.
.#define bfd_coff_swap_aouthdr_out(abfd, i,o) \
.        BFD_SEND (abfd, _bfd_coff_swap_aouthdr_out, (abfd, i, o))
.
*/