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/* Read NLM (NetWare Loadable Module) format executable files for GDB.

   Copyright 1993, 1994, 1995, 1996, 1998, 1999, 2000

   Free Software Foundation, Inc.

   Written by Fred Fish at Cygnus Support (fnf@cygnus.com).

   This file is part of GDB.

   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.  */

#include "defs.h"

#include "bfd.h"

#include "symtab.h"

#include "symfile.h"

#include "objfiles.h"

#include "buildsym.h"

#include "stabsread.h"

extern void _initialize_nlmread (void);

static void nlm_new_init (struct objfile *);

static void nlm_symfile_init (struct objfile *);

static void nlm_symfile_read (struct objfile *, int);

static void nlm_symfile_finish (struct objfile *);

static void nlm_symtab_read (bfd *, CORE_ADDR, struct objfile *);

/* Initialize anything that needs initializing when a completely new symbol

   file is specified (not just adding some symbols from another file, e.g. a

   shared library).

   We reinitialize buildsym, since gdb will be able to read stabs from an NLM

   file at some point in the near future.  */

static void

nlm_new_init (struct objfile *ignore)

{

  stabsread_new_init ();

  buildsym_new_init ();

}

/* NLM specific initialization routine for reading symbols.

   It is passed a pointer to a struct sym_fns which contains, among other

   things, the BFD for the file whose symbols are being read, and a slot for

   a pointer to "private data" which we can fill with goodies.

   For now at least, we have nothing in particular to do, so this function is

   just a stub. */

static void

nlm_symfile_init (struct objfile *ignore)

{

}

/*

   LOCAL FUNCTION

   nlm_symtab_read -- read the symbol table of an NLM file

   SYNOPSIS

   void nlm_symtab_read (bfd *abfd, CORE_ADDR addr,

   struct objfile *objfile)

   DESCRIPTION

   Given an open bfd, a base address to relocate symbols to, and a

   flag that specifies whether or not this bfd is for an executable

   or not (may be shared library for example), add all the global

   function and data symbols to the minimal symbol table.

 */

static void

nlm_symtab_read (bfd *abfd, CORE_ADDR addr, struct objfile *objfile)

{

  long storage_needed;

  asymbol *sym;

  asymbol **symbol_table;

  long number_of_symbols;

  long i;

  struct cleanup *back_to;

  CORE_ADDR symaddr;

  enum minimal_symbol_type ms_type;

  storage_needed = bfd_get_symtab_upper_bound (abfd);

  if (storage_needed < 0)

    error ("Can't read symbols from %s: %s", bfd_get_filename (abfd),

           bfd_errmsg (bfd_get_error ()));

  if (storage_needed > 0)

    {

      symbol_table = (asymbol **) xmalloc (storage_needed);

      back_to = make_cleanup (xfree, symbol_table);

      number_of_symbols = bfd_canonicalize_symtab (abfd, symbol_table);

      if (number_of_symbols < 0)

        error ("Can't read symbols from %s: %s", bfd_get_filename (abfd),

               bfd_errmsg (bfd_get_error ()));

      for (i = 0; i < number_of_symbols; i++)

        {

          sym = symbol_table[i];

          if ( /*sym -> flags & BSF_GLOBAL */ 1)

            {

              /* Bfd symbols are section relative. */

              symaddr = sym->value + sym->section->vma;

              /* Relocate all non-absolute symbols by base address.  */

              if (sym->section != &bfd_abs_section)

                symaddr += addr;

              /* For non-absolute symbols, use the type of the section

                 they are relative to, to intuit text/data.  BFD provides

                 no way of figuring this out for absolute symbols. */

              if (sym->section->flags & SEC_CODE)

                ms_type = mst_text;

              else if (sym->section->flags & SEC_DATA)

                ms_type = mst_data;

              else

                ms_type = mst_unknown;

              prim_record_minimal_symbol (sym->name, symaddr, ms_type,

                                          objfile);

            }

        }

      do_cleanups (back_to);

    }

}

/* Scan and build partial symbols for a symbol file.

   We have been initialized by a call to nlm_symfile_init, which

   currently does nothing.

   SECTION_OFFSETS is a set of offsets to apply to relocate the symbols

   in each section.  We simplify it down to a single offset for all

   symbols.  FIXME.

   MAINLINE is true if we are reading the main symbol

   table (as opposed to a shared lib or dynamically loaded file).

   This function only does the minimum work necessary for letting the

   user "name" things symbolically; it does not read the entire symtab.

   Instead, it reads the external and static symbols and puts them in partial

   symbol tables.  When more extensive information is requested of a

   file, the corresponding partial symbol table is mutated into a full

   fledged symbol table by going back and reading the symbols

   for real.

   Note that NLM files have two sets of information that is potentially

   useful for building gdb's minimal symbol table.  The first is a list

   of the publically exported symbols, and is currently used to build

   bfd's canonical symbol table.  The second is an optional native debugging

   format which contains additional symbols (and possibly duplicates of

   the publically exported symbols).  The optional native debugging format

   is not currently used. */

static void

nlm_symfile_read (struct objfile *objfile, int mainline)

{

  bfd *abfd = objfile->obfd;

  struct cleanup *back_to;

  CORE_ADDR offset;

  struct symbol *mainsym;

  init_minimal_symbol_collection ();

  back_to = make_cleanup_discard_minimal_symbols ();

  /* FIXME, should take a section_offsets param, not just an offset.  */

  offset = ANOFFSET (objfile->section_offsets, 0);

  /* Process the NLM export records, which become the bfd's canonical symbol

     table. */

  nlm_symtab_read (abfd, offset, objfile);

  stabsect_build_psymtabs (objfile, mainline, ".stab",

                           ".stabstr", ".text");

  mainsym = lookup_symbol ("main", NULL, VAR_NAMESPACE, NULL, NULL);

  if (mainsym

      && SYMBOL_CLASS (mainsym) == LOC_BLOCK)

    {

      objfile->ei.main_func_lowpc = BLOCK_START (SYMBOL_BLOCK_VALUE (mainsym));

      objfile->ei.main_func_highpc = BLOCK_END (SYMBOL_BLOCK_VALUE (mainsym));

    }

  /* FIXME:  We could locate and read the optional native debugging format

     here and add the symbols to the minimal symbol table. */

  /* Install any minimal symbols that have been collected as the current

     minimal symbols for this objfile. */

  install_minimal_symbols (objfile);

  do_cleanups (back_to);

}

/* Perform any local cleanups required when we are done with a particular

   objfile.  I.E, we are in the process of discarding all symbol information

   for an objfile, freeing up all memory held for it, and unlinking the

   objfile struct from the global list of known objfiles. */

static void

nlm_symfile_finish (struct objfile *objfile)

{

  if (objfile->sym_private != NULL)

    {

      mfree (objfile->md, objfile->sym_private);

    }

}

/* Register that we are able to handle NLM file format. */

static struct sym_fns nlm_sym_fns =

{

  bfd_target_nlm_flavour,

  nlm_new_init,                 /* sym_new_init: init anything gbl to entire symtab */

  nlm_symfile_init,             /* sym_init: read initial info, setup for sym_read() */

  nlm_symfile_read,             /* sym_read: read a symbol file into symtab */

  nlm_symfile_finish,           /* sym_finish: finished with file, cleanup */

  default_symfile_offsets,      /* sym_offsets:  Translate ext. to int. relocation */

  NULL                          /* next: pointer to next struct sym_fns */

};

void

_initialize_nlmread (void)

{

  add_symtab_fns (&nlm_sym_fns);

}