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
29 void
obj_aout_frob_symbol(symbolS * sym,int * punt ATTRIBUTE_UNUSED)30 obj_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
120 void
obj_aout_frob_file_before_fix(void)121 obj_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
138 static void
obj_aout_line(int ignore ATTRIBUTE_UNUSED)139 obj_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
150 static void
obj_aout_weak(int ignore ATTRIBUTE_UNUSED)151 obj_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
182 static void
obj_aout_type(int ignore ATTRIBUTE_UNUSED)183 obj_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
214 static void
aout_pop_insert(void)215 aout_pop_insert (void)
216 {
217 pop_insert (aout_pseudo_table);
218 }
219
220 static int
obj_aout_s_get_other(symbolS * sym)221 obj_aout_s_get_other (symbolS *sym)
222 {
223 return aout_symbol (symbol_get_bfdsym (sym))->other;
224 }
225
226 static void
obj_aout_s_set_other(symbolS * sym,int o)227 obj_aout_s_set_other (symbolS *sym, int o)
228 {
229 aout_symbol (symbol_get_bfdsym (sym))->other = o;
230 }
231
232 static int
obj_aout_sec_sym_ok_for_reloc(asection * sec ATTRIBUTE_UNUSED)233 obj_aout_sec_sym_ok_for_reloc (asection *sec ATTRIBUTE_UNUSED)
234 {
235 return obj_sec_sym_ok_for_reloc (sec);
236 }
237
238 static void
obj_aout_process_stab(segT seg ATTRIBUTE_UNUSED,int w,const char * s,int t,int o,int d)239 obj_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
249 static int
obj_aout_s_get_desc(symbolS * sym)250 obj_aout_s_get_desc (symbolS *sym)
251 {
252 return aout_symbol (symbol_get_bfdsym (sym))->desc;
253 }
254
255 static void
obj_aout_s_set_desc(symbolS * sym,int d)256 obj_aout_s_set_desc (symbolS *sym, int d)
257 {
258 aout_symbol (symbol_get_bfdsym (sym))->desc = d;
259 }
260
261 static int
obj_aout_s_get_type(symbolS * sym)262 obj_aout_s_get_type (symbolS *sym)
263 {
264 return aout_symbol (symbol_get_bfdsym (sym))->type;
265 }
266
267 static void
obj_aout_s_set_type(symbolS * sym,int t)268 obj_aout_s_set_type (symbolS *sym, int t)
269 {
270 aout_symbol (symbol_get_bfdsym (sym))->type = t;
271 }
272
273 static int
obj_aout_separate_stab_sections(void)274 obj_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
282 const 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
316 const 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