1/* a.out object file format
2   Copyright 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1999, 2000,
3   2001, 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
4
5   This file is part of GAS, the GNU Assembler.
6
7   GAS is free software; you can redistribute it and/or modify
8   it under the terms of the GNU General Public License as
9   published by the Free Software Foundation; either version 2,
10   or (at your option) any later version.
11
12   GAS is distributed in the hope that it will be useful, but
13   WITHOUT ANY WARRANTY; without even the implied warranty of
14   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
15   the GNU General Public License for more details.
16
17   You should have received a copy of the GNU General Public License
18   along with GAS; see the file COPYING.  If not, write to the Free
19   Software Foundation, 51 Franklin Street - Fifth Floor, Boston, MA
20   02110-1301, USA.  */
21
22#define OBJ_HEADER "obj-aout.h"
23
24#include "as.h"
25#undef NO_RELOC
26#include "aout/aout64.h"
27#include "obstack.h"
28
29void
30obj_aout_frob_symbol (symbolS *sym, int *punt ATTRIBUTE_UNUSED)
31{
32  flagword flags;
33  asection *sec;
34  int desc, type, other;
35
36  flags = symbol_get_bfdsym (sym)->flags;
37  desc = aout_symbol (symbol_get_bfdsym (sym))->desc;
38  type = aout_symbol (symbol_get_bfdsym (sym))->type;
39  other = aout_symbol (symbol_get_bfdsym (sym))->other;
40  sec = S_GET_SEGMENT (sym);
41
42  /* Only frob simple symbols this way right now.  */
43  if (! (type & ~ (N_TYPE | N_EXT)))
44    {
45      if (type == (N_UNDF | N_EXT)
46	  && sec == &bfd_abs_section)
47	{
48	  sec = bfd_und_section_ptr;
49	  S_SET_SEGMENT (sym, sec);
50	}
51
52      if ((type & N_TYPE) != N_INDR
53	  && (type & N_TYPE) != N_SETA
54	  && (type & N_TYPE) != N_SETT
55	  && (type & N_TYPE) != N_SETD
56	  && (type & N_TYPE) != N_SETB
57	  && type != N_WARNING
58	  && (sec == &bfd_abs_section
59	      || sec == &bfd_und_section))
60	return;
61      if (flags & BSF_EXPORT)
62	type |= N_EXT;
63
64      switch (type & N_TYPE)
65	{
66	case N_SETA:
67	case N_SETT:
68	case N_SETD:
69	case N_SETB:
70	  /* Set the debugging flag for constructor symbols so that
71	     BFD leaves them alone.  */
72	  symbol_get_bfdsym (sym)->flags |= BSF_DEBUGGING;
73
74	  /* You can't put a common symbol in a set.  The way a set
75	     element works is that the symbol has a definition and a
76	     name, and the linker adds the definition to the set of
77	     that name.  That does not work for a common symbol,
78	     because the linker can't tell which common symbol the
79	     user means.  FIXME: Using as_bad here may be
80	     inappropriate, since the user may want to force a
81	     particular type without regard to the semantics of sets;
82	     on the other hand, we certainly don't want anybody to be
83	     mislead into thinking that their code will work.  */
84	  if (S_IS_COMMON (sym))
85	    as_bad (_("Attempt to put a common symbol into set %s"),
86		    S_GET_NAME (sym));
87	  /* Similarly, you can't put an undefined symbol in a set.  */
88	  else if (! S_IS_DEFINED (sym))
89	    as_bad (_("Attempt to put an undefined symbol into set %s"),
90		    S_GET_NAME (sym));
91
92	  break;
93	case N_INDR:
94	  /* Put indirect symbols in the indirect section.  */
95	  S_SET_SEGMENT (sym, bfd_ind_section_ptr);
96	  symbol_get_bfdsym (sym)->flags |= BSF_INDIRECT;
97	  if (type & N_EXT)
98	    {
99	      symbol_get_bfdsym (sym)->flags |= BSF_EXPORT;
100	      symbol_get_bfdsym (sym)->flags &=~ BSF_LOCAL;
101	    }
102	  break;
103	case N_WARNING:
104	  /* Mark warning symbols.  */
105	  symbol_get_bfdsym (sym)->flags |= BSF_WARNING;
106	  break;
107	}
108    }
109  else
110    symbol_get_bfdsym (sym)->flags |= BSF_DEBUGGING;
111
112  aout_symbol (symbol_get_bfdsym (sym))->type = type;
113
114  /* Double check weak symbols.  */
115  if (S_IS_WEAK (sym) && S_IS_COMMON (sym))
116    as_bad (_("Symbol `%s' can not be both weak and common"),
117	    S_GET_NAME (sym));
118}
119
120void
121obj_aout_frob_file_before_fix (void)
122{
123  /* Relocation processing may require knowing the VMAs of the sections.
124     Since writing to a section will cause the BFD back end to compute the
125     VMAs, fake it out here....  */
126  bfd_byte b = 0;
127  bfd_boolean x = TRUE;
128  if (bfd_section_size (stdoutput, text_section) != 0)
129    x = bfd_set_section_contents (stdoutput, text_section, &b, (file_ptr) 0,
130				  (bfd_size_type) 1);
131  else if (bfd_section_size (stdoutput, data_section) != 0)
132    x = bfd_set_section_contents (stdoutput, data_section, &b, (file_ptr) 0,
133				  (bfd_size_type) 1);
134
135  assert (x);
136}
137
138static void
139obj_aout_line (int ignore ATTRIBUTE_UNUSED)
140{
141  /* Assume delimiter is part of expression.
142     BSD4.2 as fails with delightful bug, so we
143     are not being incompatible here.  */
144  new_logical_line ((char *) NULL, (int) (get_absolute_expression ()));
145  demand_empty_rest_of_line ();
146}
147
148/* Handle .weak.  This is a GNU extension.  */
149
150static void
151obj_aout_weak (int ignore ATTRIBUTE_UNUSED)
152{
153  char *name;
154  int c;
155  symbolS *symbolP;
156
157  do
158    {
159      name = input_line_pointer;
160      c = get_symbol_end ();
161      symbolP = symbol_find_or_make (name);
162      *input_line_pointer = c;
163      SKIP_WHITESPACE ();
164      S_SET_WEAK (symbolP);
165      if (c == ',')
166	{
167	  input_line_pointer++;
168	  SKIP_WHITESPACE ();
169	  if (*input_line_pointer == '\n')
170	    c = '\n';
171	}
172    }
173  while (c == ',');
174  demand_empty_rest_of_line ();
175}
176
177/* Handle .type.  On {Net,Open}BSD, this is used to set the n_other field,
178   which is then apparently used when doing dynamic linking.  Older
179   versions of gas ignored the .type pseudo-op, so we also ignore it if
180   we can't parse it.  */
181
182static void
183obj_aout_type (int ignore ATTRIBUTE_UNUSED)
184{
185  char *name;
186  int c;
187  symbolS *sym;
188
189  name = input_line_pointer;
190  c = get_symbol_end ();
191  sym = symbol_find_or_make (name);
192  *input_line_pointer = c;
193  SKIP_WHITESPACE ();
194  if (*input_line_pointer == ',')
195    {
196      ++input_line_pointer;
197      SKIP_WHITESPACE ();
198      if (*input_line_pointer == '@')
199	{
200	  ++input_line_pointer;
201	  if (strncmp (input_line_pointer, "object", 6) == 0)
202	    S_SET_OTHER (sym, 1);
203	  else if (strncmp (input_line_pointer, "function", 8) == 0)
204	    S_SET_OTHER (sym, 2);
205	}
206    }
207
208  /* Ignore everything else on the line.  */
209  s_ignore (0);
210}
211
212/* Support for an AOUT emulation.  */
213
214static void
215aout_pop_insert (void)
216{
217  pop_insert (aout_pseudo_table);
218}
219
220static int
221obj_aout_s_get_other (symbolS *sym)
222{
223  return aout_symbol (symbol_get_bfdsym (sym))->other;
224}
225
226static void
227obj_aout_s_set_other (symbolS *sym, int o)
228{
229  aout_symbol (symbol_get_bfdsym (sym))->other = o;
230}
231
232static int
233obj_aout_sec_sym_ok_for_reloc (asection *sec ATTRIBUTE_UNUSED)
234{
235  return obj_sec_sym_ok_for_reloc (sec);
236}
237
238static void
239obj_aout_process_stab (segT seg ATTRIBUTE_UNUSED,
240		       int w,
241		       const char *s,
242		       int t,
243		       int o,
244		       int d)
245{
246  aout_process_stab (w, s, t, o, d);
247}
248
249static int
250obj_aout_s_get_desc (symbolS *sym)
251{
252  return aout_symbol (symbol_get_bfdsym (sym))->desc;
253}
254
255static void
256obj_aout_s_set_desc (symbolS *sym, int d)
257{
258  aout_symbol (symbol_get_bfdsym (sym))->desc = d;
259}
260
261static int
262obj_aout_s_get_type (symbolS *sym)
263{
264  return aout_symbol (symbol_get_bfdsym (sym))->type;
265}
266
267static void
268obj_aout_s_set_type (symbolS *sym, int t)
269{
270  aout_symbol (symbol_get_bfdsym (sym))->type = t;
271}
272
273static int
274obj_aout_separate_stab_sections (void)
275{
276  return 0;
277}
278
279/* When changed, make sure these table entries match the single-format
280   definitions in obj-aout.h.  */
281
282const struct format_ops aout_format_ops =
283{
284  bfd_target_aout_flavour,
285  1,	/* dfl_leading_underscore.  */
286  0,	/* emit_section_symbols.  */
287  0,	/* begin.  */
288  0,	/* app_file.  */
289  obj_aout_frob_symbol,
290  0,	/* frob_file.  */
291  0,	/* frob_file_before_adjust.  */
292  obj_aout_frob_file_before_fix,
293  0,	/* frob_file_after_relocs.  */
294  0,	/* s_get_size.  */
295  0,	/* s_set_size.  */
296  0,	/* s_get_align.  */
297  0,	/* s_set_align.  */
298  obj_aout_s_get_other,
299  obj_aout_s_set_other,
300  obj_aout_s_get_desc,
301  obj_aout_s_set_desc,
302  obj_aout_s_get_type,
303  obj_aout_s_set_type,
304  0,	/* copy_symbol_attributes.  */
305  0,	/* generate_asm_lineno.  */
306  obj_aout_process_stab,
307  obj_aout_separate_stab_sections,
308  0,	/* init_stab_section.  */
309  obj_aout_sec_sym_ok_for_reloc,
310  aout_pop_insert,
311  0,	/* ecoff_set_ext.  */
312  0,	/* read_begin_hook.  */
313  0 	/* symbol_new_hook.  */
314};
315
316const pseudo_typeS aout_pseudo_table[] =
317{
318  {"line", obj_aout_line, 0},	/* Source code line number.  */
319  {"ln", obj_aout_line, 0},	/* COFF line number that we use anyway.  */
320
321  {"weak", obj_aout_weak, 0},	/* Mark symbol as weak.  */
322
323  {"type", obj_aout_type, 0},
324
325  /* coff debug pseudos (ignored) */
326  {"def", s_ignore, 0},
327  {"dim", s_ignore, 0},
328  {"endef", s_ignore, 0},
329  {"ident", s_ignore, 0},
330  {"line", s_ignore, 0},
331  {"ln", s_ignore, 0},
332  {"scl", s_ignore, 0},
333  {"size", s_ignore, 0},
334  {"tag", s_ignore, 0},
335  {"val", s_ignore, 0},
336  {"version", s_ignore, 0},
337
338  {"optim", s_ignore, 0},	/* For sun386i cc (?).  */
339
340  /* other stuff */
341  {"ABORT", s_abort, 0},
342
343  {NULL, NULL, 0}
344};
345