1/* Read NLM (NetWare Loadable Module) format executable files for GDB.
2   Copyright 1993, 1994, 1995, 1996, 1998, 1999, 2000
3   Free Software Foundation, Inc.
4   Written by Fred Fish at Cygnus Support (fnf@cygnus.com).
5
6   This file is part of GDB.
7
8   This program is free software; you can redistribute it and/or modify
9   it under the terms of the GNU General Public License as published by
10   the Free Software Foundation; either version 2 of the License, or
11   (at your option) any later version.
12
13   This program is distributed in the hope that it will be useful,
14   but WITHOUT ANY WARRANTY; without even the implied warranty of
15   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16   GNU General Public License for more details.
17
18   You should have received a copy of the GNU General Public License
19   along with this program; if not, write to the Free Software
20   Foundation, Inc., 59 Temple Place - Suite 330,
21   Boston, MA 02111-1307, USA.  */
22
23#include "defs.h"
24#include "bfd.h"
25#include "symtab.h"
26#include "symfile.h"
27#include "objfiles.h"
28#include "buildsym.h"
29#include "stabsread.h"
30#include "block.h"
31
32extern void _initialize_nlmread (void);
33
34static void nlm_new_init (struct objfile *);
35
36static void nlm_symfile_init (struct objfile *);
37
38static void nlm_symfile_read (struct objfile *, int);
39
40static void nlm_symfile_finish (struct objfile *);
41
42static void nlm_symtab_read (bfd *, CORE_ADDR, struct objfile *);
43
44/* Initialize anything that needs initializing when a completely new symbol
45   file is specified (not just adding some symbols from another file, e.g. a
46   shared library).
47
48   We reinitialize buildsym, since gdb will be able to read stabs from an NLM
49   file at some point in the near future.  */
50
51static void
52nlm_new_init (struct objfile *ignore)
53{
54  stabsread_new_init ();
55  buildsym_new_init ();
56}
57
58
59/* NLM specific initialization routine for reading symbols.
60
61   It is passed a pointer to a struct sym_fns which contains, among other
62   things, the BFD for the file whose symbols are being read, and a slot for
63   a pointer to "private data" which we can fill with goodies.
64
65   For now at least, we have nothing in particular to do, so this function is
66   just a stub. */
67
68static void
69nlm_symfile_init (struct objfile *ignore)
70{
71}
72
73/*
74
75   LOCAL FUNCTION
76
77   nlm_symtab_read -- read the symbol table of an NLM file
78
79   SYNOPSIS
80
81   void nlm_symtab_read (bfd *abfd, CORE_ADDR addr,
82   struct objfile *objfile)
83
84   DESCRIPTION
85
86   Given an open bfd, a base address to relocate symbols to, and a
87   flag that specifies whether or not this bfd is for an executable
88   or not (may be shared library for example), add all the global
89   function and data symbols to the minimal symbol table.
90 */
91
92static void
93nlm_symtab_read (bfd *abfd, CORE_ADDR addr, struct objfile *objfile)
94{
95  long storage_needed;
96  asymbol *sym;
97  asymbol **symbol_table;
98  long number_of_symbols;
99  long i;
100  struct cleanup *back_to;
101  CORE_ADDR symaddr;
102  enum minimal_symbol_type ms_type;
103
104  storage_needed = bfd_get_symtab_upper_bound (abfd);
105  if (storage_needed < 0)
106    error ("Can't read symbols from %s: %s", bfd_get_filename (abfd),
107	   bfd_errmsg (bfd_get_error ()));
108  if (storage_needed > 0)
109    {
110      symbol_table = (asymbol **) xmalloc (storage_needed);
111      back_to = make_cleanup (xfree, symbol_table);
112      number_of_symbols = bfd_canonicalize_symtab (abfd, symbol_table);
113      if (number_of_symbols < 0)
114	error ("Can't read symbols from %s: %s", bfd_get_filename (abfd),
115	       bfd_errmsg (bfd_get_error ()));
116
117      for (i = 0; i < number_of_symbols; i++)
118	{
119	  sym = symbol_table[i];
120	  if ( /*sym -> flags & BSF_GLOBAL */ 1)
121	    {
122	      /* Bfd symbols are section relative. */
123	      symaddr = sym->value + sym->section->vma;
124	      /* Relocate all non-absolute symbols by base address.  */
125	      if (sym->section != &bfd_abs_section)
126		symaddr += addr;
127
128	      /* For non-absolute symbols, use the type of the section
129	         they are relative to, to intuit text/data.  BFD provides
130	         no way of figuring this out for absolute symbols. */
131	      if (sym->section->flags & SEC_CODE)
132		ms_type = mst_text;
133	      else if (sym->section->flags & SEC_DATA)
134		ms_type = mst_data;
135	      else
136		ms_type = mst_unknown;
137
138	      prim_record_minimal_symbol (sym->name, symaddr, ms_type,
139					  objfile);
140	    }
141	}
142      do_cleanups (back_to);
143    }
144}
145
146
147/* Scan and build partial symbols for a symbol file.
148   We have been initialized by a call to nlm_symfile_init, which
149   currently does nothing.
150
151   SECTION_OFFSETS is a set of offsets to apply to relocate the symbols
152   in each section.  We simplify it down to a single offset for all
153   symbols.  FIXME.
154
155   MAINLINE is true if we are reading the main symbol
156   table (as opposed to a shared lib or dynamically loaded file).
157
158   This function only does the minimum work necessary for letting the
159   user "name" things symbolically; it does not read the entire symtab.
160   Instead, it reads the external and static symbols and puts them in partial
161   symbol tables.  When more extensive information is requested of a
162   file, the corresponding partial symbol table is mutated into a full
163   fledged symbol table by going back and reading the symbols
164   for real.
165
166   Note that NLM files have two sets of information that is potentially
167   useful for building gdb's minimal symbol table.  The first is a list
168   of the publically exported symbols, and is currently used to build
169   bfd's canonical symbol table.  The second is an optional native debugging
170   format which contains additional symbols (and possibly duplicates of
171   the publically exported symbols).  The optional native debugging format
172   is not currently used. */
173
174static void
175nlm_symfile_read (struct objfile *objfile, int mainline)
176{
177  bfd *abfd = objfile->obfd;
178  struct cleanup *back_to;
179  CORE_ADDR offset;
180  struct symbol *mainsym;
181
182  init_minimal_symbol_collection ();
183  back_to = make_cleanup_discard_minimal_symbols ();
184
185  /* FIXME, should take a section_offsets param, not just an offset.  */
186
187  offset = ANOFFSET (objfile->section_offsets, 0);
188
189  /* Process the NLM export records, which become the bfd's canonical symbol
190     table. */
191
192  nlm_symtab_read (abfd, offset, objfile);
193
194  /* Install any minimal symbols that have been collected as the current
195     minimal symbols for this objfile. */
196
197  install_minimal_symbols (objfile);
198  do_cleanups (back_to);
199
200  stabsect_build_psymtabs (objfile, mainline, ".stab",
201			   ".stabstr", ".text");
202
203  mainsym = lookup_symbol (main_name (), NULL, VAR_DOMAIN, NULL, NULL);
204
205  if (mainsym
206      && SYMBOL_CLASS (mainsym) == LOC_BLOCK)
207    {
208      objfile->ei.main_func_lowpc = BLOCK_START (SYMBOL_BLOCK_VALUE (mainsym));
209      objfile->ei.main_func_highpc = BLOCK_END (SYMBOL_BLOCK_VALUE (mainsym));
210    }
211
212  /* FIXME:  We could locate and read the optional native debugging format
213     here and add the symbols to the minimal symbol table. */
214}
215
216
217/* Perform any local cleanups required when we are done with a particular
218   objfile.  I.E, we are in the process of discarding all symbol information
219   for an objfile, freeing up all memory held for it, and unlinking the
220   objfile struct from the global list of known objfiles. */
221
222static void
223nlm_symfile_finish (struct objfile *objfile)
224{
225  if (objfile->sym_private != NULL)
226    {
227      xmfree (objfile->md, objfile->sym_private);
228    }
229}
230
231/* Register that we are able to handle NLM file format. */
232
233static struct sym_fns nlm_sym_fns =
234{
235  bfd_target_nlm_flavour,
236  nlm_new_init,			/* sym_new_init: init anything gbl to entire symtab */
237  nlm_symfile_init,		/* sym_init: read initial info, setup for sym_read() */
238  nlm_symfile_read,		/* sym_read: read a symbol file into symtab */
239  nlm_symfile_finish,		/* sym_finish: finished with file, cleanup */
240  default_symfile_offsets,	/* sym_offsets:  Translate ext. to int. relocation */
241  NULL				/* next: pointer to next struct sym_fns */
242};
243
244void
245_initialize_nlmread (void)
246{
247  add_symtab_fns (&nlm_sym_fns);
248}
249