1 /* a.out object file format
2 Copyright (C) 1989, 90, 91, 92, 93, 94, 95, 1996
3 Free Software Foundation, Inc.
5 This file is part of GAS, the GNU Assembler.
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.
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.
17 You should have received a copy of the GNU General Public
18 License along with GAS; see the file COPYING. If not, write
19 to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
24 #include "aout/aout64.h"
29 /* in: segT out: N_TYPE bits */
30 const short seg_N_TYPE
[] =
38 N_UNDF
, /* expression */
42 N_REGISTER
, /* register */
45 const segT N_TYPE_seg
[N_TYPE
+ 2] =
46 { /* N_TYPE == 0x1E = 32-2 */
47 SEG_UNKNOWN
, /* N_UNDF == 0 */
49 SEG_ABSOLUTE
, /* N_ABS == 2 */
51 SEG_TEXT
, /* N_TEXT == 4 */
53 SEG_DATA
, /* N_DATA == 6 */
55 SEG_BSS
, /* N_BSS == 8 */
57 SEG_GOOF
, SEG_GOOF
, SEG_GOOF
, SEG_GOOF
, SEG_GOOF
, SEG_GOOF
, SEG_GOOF
, SEG_GOOF
,
58 SEG_GOOF
, SEG_GOOF
, SEG_GOOF
, SEG_GOOF
, SEG_GOOF
, SEG_GOOF
, SEG_GOOF
, SEG_GOOF
,
59 SEG_GOOF
, SEG_GOOF
, SEG_GOOF
, SEG_GOOF
,
60 SEG_REGISTER
, /* dummy N_REGISTER for regs = 30 */
65 static void obj_aout_line
PARAMS ((int));
66 static void obj_aout_weak
PARAMS ((int));
67 static void obj_aout_type
PARAMS ((int));
69 const pseudo_typeS obj_pseudo_table
[] =
71 {"line", obj_aout_line
, 0}, /* source code line number */
72 {"ln", obj_aout_line
, 0}, /* coff line number that we use anyway */
74 {"weak", obj_aout_weak
, 0}, /* mark symbol as weak. */
76 {"type", obj_aout_type
, 0},
78 /* coff debug pseudos (ignored) */
81 {"endef", s_ignore
, 0},
82 {"ident", s_ignore
, 0},
83 {"line", s_ignore
, 0},
86 {"size", s_ignore
, 0},
89 {"version", s_ignore
, 0},
91 {"optim", s_ignore
, 0}, /* For sun386i cc (?) */
94 {"ABORT", s_abort
, 0},
96 {NULL
} /* end sentinel */
97 }; /* obj_pseudo_table */
103 obj_aout_frob_symbol (sym
, punt
)
109 int desc
, type
, other
;
111 flags
= sym
->bsym
->flags
;
112 desc
= S_GET_DESC (sym
);
113 type
= S_GET_TYPE (sym
);
114 other
= S_GET_OTHER (sym
);
115 sec
= sym
->bsym
->section
;
117 /* Only frob simple symbols this way right now. */
118 if (! (type
& ~ (N_TYPE
| N_EXT
)))
120 if (type
== (N_UNDF
| N_EXT
)
121 && sec
== &bfd_abs_section
)
122 sym
->bsym
->section
= sec
= bfd_und_section_ptr
;
124 if ((type
& N_TYPE
) != N_INDR
125 && (type
& N_TYPE
) != N_SETA
126 && (type
& N_TYPE
) != N_SETT
127 && (type
& N_TYPE
) != N_SETD
128 && (type
& N_TYPE
) != N_SETB
130 && (sec
== &bfd_abs_section
131 || sec
== &bfd_und_section
))
133 if (flags
& BSF_EXPORT
)
136 switch (type
& N_TYPE
)
142 /* Set the debugging flag for constructor symbols so that
143 BFD leaves them alone. */
144 sym
->bsym
->flags
|= BSF_DEBUGGING
;
146 /* You can't put a common symbol in a set. The way a set
147 element works is that the symbol has a definition and a
148 name, and the linker adds the definition to the set of
149 that name. That does not work for a common symbol,
150 because the linker can't tell which common symbol the
151 user means. FIXME: Using as_bad here may be
152 inappropriate, since the user may want to force a
153 particular type without regard to the semantics of sets;
154 on the other hand, we certainly don't want anybody to be
155 mislead into thinking that their code will work. */
156 if (S_IS_COMMON (sym
))
157 as_bad (_("Attempt to put a common symbol into set %s"),
159 /* Similarly, you can't put an undefined symbol in a set. */
160 else if (! S_IS_DEFINED (sym
))
161 as_bad (_("Attempt to put an undefined symbol into set %s"),
166 /* Put indirect symbols in the indirect section. */
167 sym
->bsym
->section
= bfd_ind_section_ptr
;
168 sym
->bsym
->flags
|= BSF_INDIRECT
;
171 sym
->bsym
->flags
|= BSF_EXPORT
;
172 sym
->bsym
->flags
&=~ BSF_LOCAL
;
176 /* Mark warning symbols. */
177 sym
->bsym
->flags
|= BSF_WARNING
;
183 sym
->bsym
->flags
|= BSF_DEBUGGING
;
186 S_SET_TYPE (sym
, type
);
188 /* Double check weak symbols. */
189 if (sym
->bsym
->flags
& BSF_WEAK
)
191 if (S_IS_COMMON (sym
))
192 as_bad (_("Symbol `%s' can not be both weak and common"),
198 obj_aout_frob_file ()
200 /* Relocation processing may require knowing the VMAs of the sections.
201 Since writing to a section will cause the BFD back end to compute the
202 VMAs, fake it out here.... */
205 if (bfd_section_size (stdoutput
, text_section
) != 0)
207 x
= bfd_set_section_contents (stdoutput
, text_section
, &b
, (file_ptr
) 0,
210 else if (bfd_section_size (stdoutput
, data_section
) != 0)
212 x
= bfd_set_section_contents (stdoutput
, data_section
, &b
, (file_ptr
) 0,
225 * Crawl along a fixS chain. Emit the segment's relocations.
228 obj_emit_relocations (where
, fixP
, segment_address_in_file
)
230 fixS
*fixP
; /* Fixup chain for this segment. */
231 relax_addressT segment_address_in_file
;
233 for (; fixP
; fixP
= fixP
->fx_next
)
234 if (fixP
->fx_done
== 0)
238 sym
= fixP
->fx_addsy
;
239 while (sym
->sy_value
.X_op
== O_symbol
240 && (! S_IS_DEFINED (sym
) || S_IS_COMMON (sym
)))
241 sym
= sym
->sy_value
.X_add_symbol
;
242 fixP
->fx_addsy
= sym
;
244 if (! sym
->sy_resolved
&& ! S_IS_DEFINED (sym
))
249 if (expr_symbol_where (sym
, &file
, &line
))
250 as_bad_where (file
, line
, _("unresolved relocation"));
252 as_bad (_("bad relocation: symbol `%s' not in symbol table"),
256 tc_aout_fix_to_chars (*where
, fixP
, segment_address_in_file
);
257 *where
+= md_reloc_size
;
261 #ifndef obj_header_append
262 /* Aout file generation & utilities */
264 obj_header_append (where
, headers
)
266 object_headers
*headers
;
268 tc_headers_hook (headers
);
271 md_number_to_chars (*where
, headers
->header
.a_info
, sizeof (headers
->header
.a_info
));
272 *where
+= sizeof (headers
->header
.a_info
);
273 md_number_to_chars (*where
, headers
->header
.a_text
, sizeof (headers
->header
.a_text
));
274 *where
+= sizeof (headers
->header
.a_text
);
275 md_number_to_chars (*where
, headers
->header
.a_data
, sizeof (headers
->header
.a_data
));
276 *where
+= sizeof (headers
->header
.a_data
);
277 md_number_to_chars (*where
, headers
->header
.a_bss
, sizeof (headers
->header
.a_bss
));
278 *where
+= sizeof (headers
->header
.a_bss
);
279 md_number_to_chars (*where
, headers
->header
.a_syms
, sizeof (headers
->header
.a_syms
));
280 *where
+= sizeof (headers
->header
.a_syms
);
281 md_number_to_chars (*where
, headers
->header
.a_entry
, sizeof (headers
->header
.a_entry
));
282 *where
+= sizeof (headers
->header
.a_entry
);
283 md_number_to_chars (*where
, headers
->header
.a_trsize
, sizeof (headers
->header
.a_trsize
));
284 *where
+= sizeof (headers
->header
.a_trsize
);
285 md_number_to_chars (*where
, headers
->header
.a_drsize
, sizeof (headers
->header
.a_drsize
));
286 *where
+= sizeof (headers
->header
.a_drsize
);
288 #else /* CROSS_COMPILE */
290 append (where
, (char *) &headers
->header
, sizeof (headers
->header
));
291 #endif /* CROSS_COMPILE */
297 obj_symbol_to_chars (where
, symbolP
)
301 md_number_to_chars ((char *) &(S_GET_OFFSET (symbolP
)), S_GET_OFFSET (symbolP
), sizeof (S_GET_OFFSET (symbolP
)));
302 md_number_to_chars ((char *) &(S_GET_DESC (symbolP
)), S_GET_DESC (symbolP
), sizeof (S_GET_DESC (symbolP
)));
303 md_number_to_chars ((char *) &(symbolP
->sy_symbol
.n_value
), S_GET_VALUE (symbolP
), sizeof (symbolP
->sy_symbol
.n_value
));
305 append (where
, (char *) &symbolP
->sy_symbol
, sizeof (obj_symbol_type
));
309 obj_emit_symbols (where
, symbol_rootP
)
311 symbolS
*symbol_rootP
;
315 /* Emit all symbols left in the symbol chain. */
316 for (symbolP
= symbol_rootP
; symbolP
; symbolP
= symbol_next (symbolP
))
318 /* Used to save the offset of the name. It is used to point
319 to the string in memory but must be a file offset. */
322 temp
= S_GET_NAME (symbolP
);
323 S_SET_OFFSET (symbolP
, symbolP
->sy_name_offset
);
325 /* Any symbol still undefined and is not a dbg symbol is made N_EXT. */
326 if (!S_IS_DEBUG (symbolP
) && !S_IS_DEFINED (symbolP
))
327 S_SET_EXTERNAL (symbolP
);
329 /* Adjust the type of a weak symbol. */
330 if (S_GET_WEAK (symbolP
))
332 switch (S_GET_TYPE (symbolP
))
334 case N_UNDF
: S_SET_TYPE (symbolP
, N_WEAKU
); break;
335 case N_ABS
: S_SET_TYPE (symbolP
, N_WEAKA
); break;
336 case N_TEXT
: S_SET_TYPE (symbolP
, N_WEAKT
); break;
337 case N_DATA
: S_SET_TYPE (symbolP
, N_WEAKD
); break;
338 case N_BSS
: S_SET_TYPE (symbolP
, N_WEAKB
); break;
339 default: as_bad (_("%s: bad type for weak symbol"), temp
); break;
343 obj_symbol_to_chars (where
, symbolP
);
344 S_SET_NAME (symbolP
, temp
);
348 #endif /* ! BFD_ASSEMBLER */
351 obj_aout_line (ignore
)
354 /* Assume delimiter is part of expression.
355 BSD4.2 as fails with delightful bug, so we
356 are not being incompatible here. */
357 new_logical_line ((char *) NULL
, (int) (get_absolute_expression ()));
358 demand_empty_rest_of_line ();
359 } /* obj_aout_line() */
361 /* Handle .weak. This is a GNU extension. */
364 obj_aout_weak (ignore
)
373 name
= input_line_pointer
;
374 c
= get_symbol_end ();
375 symbolP
= symbol_find_or_make (name
);
376 *input_line_pointer
= c
;
378 S_SET_WEAK (symbolP
);
381 input_line_pointer
++;
383 if (*input_line_pointer
== '\n')
388 demand_empty_rest_of_line ();
391 /* Handle .type. On {Net,Open}BSD, this is used to set the n_other field,
392 which is then apparently used when doing dynamic linking. Older
393 versions ogas ignored the .type pseudo-op, so we also ignore it if
394 we can't parse it. */
397 obj_aout_type (ignore
)
404 name
= input_line_pointer
;
405 c
= get_symbol_end ();
406 sym
= symbol_find (name
);
407 *input_line_pointer
= c
;
411 if (*input_line_pointer
== ',')
413 ++input_line_pointer
;
415 if (*input_line_pointer
== '@')
417 ++input_line_pointer
;
418 if (strncmp (input_line_pointer
, "object", 6) == 0)
419 S_SET_OTHER (sym
, 1);
420 else if (strncmp (input_line_pointer
, "function", 8) == 0)
421 S_SET_OTHER (sym
, 2);
426 /* Ignore everything else on the line. */
431 obj_read_begin_hook ()
435 #ifndef BFD_ASSEMBLER
438 obj_crawl_symbol_chain (headers
)
439 object_headers
*headers
;
443 int symbol_number
= 0;
445 tc_crawl_symbol_chain (headers
);
447 symbolPP
= &symbol_rootP
; /*->last symbol chain link. */
448 while ((symbolP
= *symbolPP
) != NULL
)
450 if (symbolP
->sy_mri_common
)
452 if (S_IS_EXTERNAL (symbolP
))
453 as_bad (_("%s: global symbols not supported in common sections"),
454 S_GET_NAME (symbolP
));
455 *symbolPP
= symbol_next (symbolP
);
459 if (flag_readonly_data_in_text
&& (S_GET_SEGMENT (symbolP
) == SEG_DATA
))
461 S_SET_SEGMENT (symbolP
, SEG_TEXT
);
462 } /* if pusing data into text */
464 resolve_symbol_value (symbolP
, 1);
466 /* Skip symbols which were equated to undefined or common
468 if (symbolP
->sy_value
.X_op
== O_symbol
469 && (! S_IS_DEFINED (symbolP
) || S_IS_COMMON (symbolP
)))
471 *symbolPP
= symbol_next (symbolP
);
475 /* OK, here is how we decide which symbols go out into the brave
476 new symtab. Symbols that do are:
478 * symbols with no name (stabd's?)
479 * symbols with debug info in their N_TYPE
481 Symbols that don't are:
482 * symbols that are registers
483 * symbols with \1 as their 3rd character (numeric labels)
484 * "local labels" as defined by S_LOCAL_NAME(name) if the -L
485 switch was passed to gas.
487 All other symbols are output. We complain if a deleted
488 symbol was marked external. */
491 if (!S_IS_REGISTER (symbolP
)
492 && (!S_GET_NAME (symbolP
)
493 || S_IS_DEBUG (symbolP
)
494 || !S_IS_DEFINED (symbolP
)
495 || S_IS_EXTERNAL (symbolP
)
496 || (S_GET_NAME (symbolP
)[0] != '\001'
497 && (flag_keep_locals
|| !S_LOCAL_NAME (symbolP
)))))
499 symbolP
->sy_number
= symbol_number
++;
501 /* The + 1 after strlen account for the \0 at the
502 end of each string */
503 if (!S_IS_STABD (symbolP
))
506 symbolP
->sy_name_offset
= string_byte_count
;
507 string_byte_count
+= strlen (S_GET_NAME (symbolP
)) + 1;
509 else /* .Stabd case. */
510 symbolP
->sy_name_offset
= 0;
511 symbolPP
= &(symbol_next (symbolP
));
515 if (S_IS_EXTERNAL (symbolP
) || !S_IS_DEFINED (symbolP
))
516 /* This warning should never get triggered any more.
517 Well, maybe if you're doing twisted things with
520 as_bad (_("Local symbol %s never defined."), decode_local_label_name (S_GET_NAME (symbolP
)));
523 /* Unhook it from the chain */
524 *symbolPP
= symbol_next (symbolP
);
525 } /* if this symbol should be in the output */
526 } /* for each symbol */
528 H_SET_SYMBOL_TABLE_SIZE (headers
, symbol_number
);
532 * Find strings by crawling along symbol table chain.
536 obj_emit_strings (where
)
542 /* Gotta do md_ byte-ordering stuff for string_byte_count first - KWK */
543 md_number_to_chars (*where
, string_byte_count
, sizeof (string_byte_count
));
544 *where
+= sizeof (string_byte_count
);
545 #else /* CROSS_COMPILE */
546 append (where
, (char *) &string_byte_count
, (unsigned long) sizeof (string_byte_count
));
547 #endif /* CROSS_COMPILE */
549 for (symbolP
= symbol_rootP
; symbolP
; symbolP
= symbol_next (symbolP
))
551 if (S_GET_NAME (symbolP
))
552 append (&next_object_file_charP
, S_GET_NAME (symbolP
),
553 (unsigned long) (strlen (S_GET_NAME (symbolP
)) + 1));
554 } /* walk symbol chain */
558 #define AOUT_VERSION 0
562 obj_pre_write_hook (headers
)
563 object_headers
*headers
;
565 H_SET_DYNAMIC (headers
, 0);
566 H_SET_VERSION (headers
, AOUT_VERSION
);
567 H_SET_MACHTYPE (headers
, AOUT_MACHTYPE
);
568 tc_aout_pre_write_hook (headers
);
574 /* Strip out the section name */
576 char *section_name_end
;
583 section_name
= input_line_pointer
;
584 c
= get_symbol_end ();
585 section_name_end
= input_line_pointer
;
587 len
= section_name_end
- section_name
;
588 input_line_pointer
++;
589 save
= input_line_pointer
;
594 exp
= get_absolute_expression ();
596 else if (*input_line_pointer
== ',')
598 input_line_pointer
++;
599 exp
= get_absolute_expression ();
603 input_line_pointer
= save
;
608 as_bad (_("subsegment index too high"));
611 if (strcmp (section_name
, ".text") == 0)
613 subseg_set (SEG_TEXT
, (subsegT
) exp
);
616 if (strcmp (section_name
, ".data") == 0)
618 if (flag_readonly_data_in_text
)
619 subseg_set (SEG_TEXT
, (subsegT
) exp
+ 1000);
621 subseg_set (SEG_DATA
, (subsegT
) exp
);
624 *section_name_end
= c
;
627 #endif /* ! BFD_ASSEMBLER */
629 /* end of obj-aout.c */