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.
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 License
18 along with GAS; see the file COPYING. If not, write to the Free
19 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
22 #define OBJ_HEADER "obj-aout.h"
27 #include "aout/aout64.h"
32 /* in: segT out: N_TYPE bits */
33 const short seg_N_TYPE
[] =
41 N_UNDF
, /* expression */
45 N_REGISTER
, /* register */
48 const segT N_TYPE_seg
[N_TYPE
+ 2] =
49 { /* N_TYPE == 0x1E = 32-2 */
50 SEG_UNKNOWN
, /* N_UNDF == 0 */
52 SEG_ABSOLUTE
, /* N_ABS == 2 */
54 SEG_TEXT
, /* N_TEXT == 4 */
56 SEG_DATA
, /* N_DATA == 6 */
58 SEG_BSS
, /* N_BSS == 8 */
60 SEG_GOOF
, SEG_GOOF
, SEG_GOOF
, SEG_GOOF
, SEG_GOOF
, SEG_GOOF
, SEG_GOOF
, SEG_GOOF
,
61 SEG_GOOF
, SEG_GOOF
, SEG_GOOF
, SEG_GOOF
, SEG_GOOF
, SEG_GOOF
, SEG_GOOF
, SEG_GOOF
,
62 SEG_GOOF
, SEG_GOOF
, SEG_GOOF
, SEG_GOOF
,
63 SEG_REGISTER
, /* dummy N_REGISTER for regs = 30 */
68 static void obj_aout_line
PARAMS ((int));
69 static void obj_aout_weak
PARAMS ((int));
70 static void obj_aout_type
PARAMS ((int));
72 const pseudo_typeS aout_pseudo_table
[] =
74 {"line", obj_aout_line
, 0}, /* source code line number */
75 {"ln", obj_aout_line
, 0}, /* coff line number that we use anyway */
77 {"weak", obj_aout_weak
, 0}, /* mark symbol as weak. */
79 {"type", obj_aout_type
, 0},
81 /* coff debug pseudos (ignored) */
84 {"endef", s_ignore
, 0},
85 {"ident", s_ignore
, 0},
86 {"line", s_ignore
, 0},
89 {"size", s_ignore
, 0},
92 {"version", s_ignore
, 0},
94 {"optim", s_ignore
, 0}, /* For sun386i cc (?) */
97 {"ABORT", s_abort
, 0},
99 {NULL
, NULL
, 0} /* end sentinel */
100 }; /* aout_pseudo_table */
105 obj_aout_frob_symbol (sym
, punt
)
107 int *punt ATTRIBUTE_UNUSED
;
111 int desc
, type
, other
;
113 flags
= symbol_get_bfdsym (sym
)->flags
;
114 desc
= aout_symbol (symbol_get_bfdsym (sym
))->desc
;
115 type
= aout_symbol (symbol_get_bfdsym (sym
))->type
;
116 other
= aout_symbol (symbol_get_bfdsym (sym
))->other
;
117 sec
= S_GET_SEGMENT (sym
);
119 /* Only frob simple symbols this way right now. */
120 if (! (type
& ~ (N_TYPE
| N_EXT
)))
122 if (type
== (N_UNDF
| N_EXT
)
123 && sec
== &bfd_abs_section
)
125 sec
= bfd_und_section_ptr
;
126 S_SET_SEGMENT (sym
, sec
);
129 if ((type
& N_TYPE
) != N_INDR
130 && (type
& N_TYPE
) != N_SETA
131 && (type
& N_TYPE
) != N_SETT
132 && (type
& N_TYPE
) != N_SETD
133 && (type
& N_TYPE
) != N_SETB
135 && (sec
== &bfd_abs_section
136 || sec
== &bfd_und_section
))
138 if (flags
& BSF_EXPORT
)
141 switch (type
& N_TYPE
)
147 /* Set the debugging flag for constructor symbols so that
148 BFD leaves them alone. */
149 symbol_get_bfdsym (sym
)->flags
|= BSF_DEBUGGING
;
151 /* You can't put a common symbol in a set. The way a set
152 element works is that the symbol has a definition and a
153 name, and the linker adds the definition to the set of
154 that name. That does not work for a common symbol,
155 because the linker can't tell which common symbol the
156 user means. FIXME: Using as_bad here may be
157 inappropriate, since the user may want to force a
158 particular type without regard to the semantics of sets;
159 on the other hand, we certainly don't want anybody to be
160 mislead into thinking that their code will work. */
161 if (S_IS_COMMON (sym
))
162 as_bad (_("Attempt to put a common symbol into set %s"),
164 /* Similarly, you can't put an undefined symbol in a set. */
165 else if (! S_IS_DEFINED (sym
))
166 as_bad (_("Attempt to put an undefined symbol into set %s"),
171 /* Put indirect symbols in the indirect section. */
172 S_SET_SEGMENT (sym
, bfd_ind_section_ptr
);
173 symbol_get_bfdsym (sym
)->flags
|= BSF_INDIRECT
;
176 symbol_get_bfdsym (sym
)->flags
|= BSF_EXPORT
;
177 symbol_get_bfdsym (sym
)->flags
&=~ BSF_LOCAL
;
181 /* Mark warning symbols. */
182 symbol_get_bfdsym (sym
)->flags
|= BSF_WARNING
;
188 symbol_get_bfdsym (sym
)->flags
|= BSF_DEBUGGING
;
191 aout_symbol (symbol_get_bfdsym (sym
))->type
= type
;
193 /* Double check weak symbols. */
196 if (S_IS_COMMON (sym
))
197 as_bad (_("Symbol `%s' can not be both weak and common"),
203 obj_aout_frob_file_before_fix ()
205 /* Relocation processing may require knowing the VMAs of the sections.
206 Since writing to a section will cause the BFD back end to compute the
207 VMAs, fake it out here.... */
209 bfd_boolean x
= TRUE
;
210 if (bfd_section_size (stdoutput
, text_section
) != 0)
212 x
= bfd_set_section_contents (stdoutput
, text_section
, &b
, (file_ptr
) 0,
215 else if (bfd_section_size (stdoutput
, data_section
) != 0)
217 x
= bfd_set_section_contents (stdoutput
, data_section
, &b
, (file_ptr
) 0,
223 #else /* ! BFD_ASSEMBLER */
230 * Crawl along a fixS chain. Emit the segment's relocations.
233 obj_emit_relocations (where
, fixP
, segment_address_in_file
)
235 fixS
*fixP
; /* Fixup chain for this segment. */
236 relax_addressT segment_address_in_file
;
238 for (; fixP
; fixP
= fixP
->fx_next
)
239 if (fixP
->fx_done
== 0)
243 sym
= fixP
->fx_addsy
;
244 while (sym
->sy_value
.X_op
== O_symbol
245 && (! S_IS_DEFINED (sym
) || S_IS_COMMON (sym
)))
246 sym
= sym
->sy_value
.X_add_symbol
;
247 fixP
->fx_addsy
= sym
;
249 if (! sym
->sy_resolved
&& ! S_IS_DEFINED (sym
))
254 if (expr_symbol_where (sym
, &file
, &line
))
255 as_bad_where (file
, line
, _("unresolved relocation"));
257 as_bad (_("bad relocation: symbol `%s' not in symbol table"),
261 tc_aout_fix_to_chars (*where
, fixP
, segment_address_in_file
);
262 *where
+= md_reloc_size
;
266 #ifndef obj_header_append
267 /* Aout file generation & utilities */
269 /* An AOUT header on disk is laid out in target byte order. */
272 obj_header_append (where
, headers
)
274 object_headers
*headers
;
278 tc_headers_hook (headers
);
280 #ifdef __A_OUT_GNU_H__
281 #define SIZEOF_HEADER(PIECE) (sizeof (((struct exec_bytes *) 0)->PIECE))
283 #define SIZEOF_HEADER(PIECE) 4
286 md_number_to_chars (p, headers->header.PIECE, SIZEOF_HEADER (PIECE)); \
287 p += SIZEOF_HEADER (PIECE);
302 #endif /* ! defined (obj_header_append) */
305 obj_symbol_to_chars (where
, symbolP
)
310 md_number_to_chars (p
, S_GET_OFFSET (symbolP
), 4);
312 /* Can't use S_GET_TYPE here as it masks. */
313 *p
++ = symbolP
->sy_symbol
.n_type
;
314 *p
++ = symbolP
->sy_symbol
.n_other
;
315 md_number_to_chars (p
, S_GET_DESC (symbolP
), 2);
317 md_number_to_chars (p
, S_GET_VALUE (symbolP
), 4);
323 obj_emit_symbols (where
, symbol_rootP
)
325 symbolS
*symbol_rootP
;
329 /* Emit all symbols left in the symbol chain. */
330 for (symbolP
= symbol_rootP
; symbolP
; symbolP
= symbol_next (symbolP
))
332 /* Used to save the offset of the name. It is used to point
333 to the string in memory but must be a file offset. */
336 temp
= S_GET_NAME (symbolP
);
337 S_SET_OFFSET (symbolP
, symbolP
->sy_name_offset
);
339 /* Any symbol still undefined and is not a dbg symbol is made N_EXT. */
340 if (!S_IS_DEBUG (symbolP
) && !S_IS_DEFINED (symbolP
))
341 S_SET_EXTERNAL (symbolP
);
343 /* Adjust the type of a weak symbol. */
344 if (S_GET_WEAK (symbolP
))
346 switch (S_GET_TYPE (symbolP
))
348 case N_UNDF
: S_SET_TYPE (symbolP
, N_WEAKU
); break;
349 case N_ABS
: S_SET_TYPE (symbolP
, N_WEAKA
); break;
350 case N_TEXT
: S_SET_TYPE (symbolP
, N_WEAKT
); break;
351 case N_DATA
: S_SET_TYPE (symbolP
, N_WEAKD
); break;
352 case N_BSS
: S_SET_TYPE (symbolP
, N_WEAKB
); break;
353 default: as_bad (_("%s: bad type for weak symbol"), temp
); break;
357 obj_symbol_to_chars (where
, symbolP
);
358 S_SET_NAME (symbolP
, temp
);
362 #endif /* ! BFD_ASSEMBLER */
365 obj_aout_line (ignore
)
366 int ignore ATTRIBUTE_UNUSED
;
368 /* Assume delimiter is part of expression.
369 BSD4.2 as fails with delightful bug, so we
370 are not being incompatible here. */
371 new_logical_line ((char *) NULL
, (int) (get_absolute_expression ()));
372 demand_empty_rest_of_line ();
373 } /* obj_aout_line() */
375 /* Handle .weak. This is a GNU extension. */
378 obj_aout_weak (ignore
)
379 int ignore ATTRIBUTE_UNUSED
;
387 name
= input_line_pointer
;
388 c
= get_symbol_end ();
389 symbolP
= symbol_find_or_make (name
);
390 *input_line_pointer
= c
;
392 S_SET_WEAK (symbolP
);
395 input_line_pointer
++;
397 if (*input_line_pointer
== '\n')
402 demand_empty_rest_of_line ();
405 /* Handle .type. On {Net,Open}BSD, this is used to set the n_other field,
406 which is then apparently used when doing dynamic linking. Older
407 versions of gas ignored the .type pseudo-op, so we also ignore it if
408 we can't parse it. */
411 obj_aout_type (ignore
)
412 int ignore ATTRIBUTE_UNUSED
;
418 name
= input_line_pointer
;
419 c
= get_symbol_end ();
420 sym
= symbol_find_or_make (name
);
421 *input_line_pointer
= c
;
423 if (*input_line_pointer
== ',')
425 ++input_line_pointer
;
427 if (*input_line_pointer
== '@')
429 ++input_line_pointer
;
430 if (strncmp (input_line_pointer
, "object", 6) == 0)
431 S_SET_OTHER (sym
, 1);
432 else if (strncmp (input_line_pointer
, "function", 8) == 0)
433 S_SET_OTHER (sym
, 2);
437 /* Ignore everything else on the line. */
441 #ifndef BFD_ASSEMBLER
444 obj_crawl_symbol_chain (headers
)
445 object_headers
*headers
;
449 int symbol_number
= 0;
451 tc_crawl_symbol_chain (headers
);
453 symbolPP
= &symbol_rootP
; /*->last symbol chain link. */
454 while ((symbolP
= *symbolPP
) != NULL
)
456 if (symbolP
->sy_mri_common
)
458 if (S_IS_EXTERNAL (symbolP
))
459 as_bad (_("%s: global symbols not supported in common sections"),
460 S_GET_NAME (symbolP
));
461 *symbolPP
= symbol_next (symbolP
);
465 if (flag_readonly_data_in_text
&& (S_GET_SEGMENT (symbolP
) == SEG_DATA
))
467 S_SET_SEGMENT (symbolP
, SEG_TEXT
);
468 } /* if pushing data into text */
470 resolve_symbol_value (symbolP
);
472 /* Skip symbols which were equated to undefined or common
473 symbols. Also skip defined uncommon symbols which can
474 be resolved since in this case they should have been
475 resolved to a non-symbolic constant. */
476 if (symbolP
->sy_value
.X_op
== O_symbol
477 && (! S_IS_DEFINED (symbolP
)
478 || S_IS_COMMON (symbolP
)
479 || symbol_resolved_p (symbolP
)))
481 *symbolPP
= symbol_next (symbolP
);
485 /* OK, here is how we decide which symbols go out into the brave
486 new symtab. Symbols that do are:
488 * symbols with no name (stabd's?)
489 * symbols with debug info in their N_TYPE
491 Symbols that don't are:
492 * symbols that are registers
493 * symbols with \1 as their 3rd character (numeric labels)
494 * "local labels" as defined by S_LOCAL_NAME(name) if the -L
495 switch was passed to gas.
497 All other symbols are output. We complain if a deleted
498 symbol was marked external. */
500 if (!S_IS_REGISTER (symbolP
)
501 && (!S_GET_NAME (symbolP
)
502 || S_IS_DEBUG (symbolP
)
503 || !S_IS_DEFINED (symbolP
)
504 || S_IS_EXTERNAL (symbolP
)
505 || (S_GET_NAME (symbolP
)[0] != '\001'
506 && (flag_keep_locals
|| !S_LOCAL_NAME (symbolP
)))))
508 symbolP
->sy_number
= symbol_number
++;
510 /* The + 1 after strlen account for the \0 at the
511 end of each string */
512 if (!S_IS_STABD (symbolP
))
515 symbolP
->sy_name_offset
= string_byte_count
;
516 string_byte_count
+= strlen (S_GET_NAME (symbolP
)) + 1;
518 else /* .Stabd case. */
519 symbolP
->sy_name_offset
= 0;
520 symbolPP
= &symbolP
->sy_next
;
524 if (S_IS_EXTERNAL (symbolP
) || !S_IS_DEFINED (symbolP
))
525 /* This warning should never get triggered any more.
526 Well, maybe if you're doing twisted things with
529 as_bad (_("Local symbol %s never defined."), decode_local_label_name (S_GET_NAME (symbolP
)));
532 /* Unhook it from the chain */
533 *symbolPP
= symbol_next (symbolP
);
534 } /* if this symbol should be in the output */
535 } /* for each symbol */
537 H_SET_SYMBOL_TABLE_SIZE (headers
, symbol_number
);
541 * Find strings by crawling along symbol table chain.
545 obj_emit_strings (where
)
550 md_number_to_chars (*where
, string_byte_count
, 4);
553 for (symbolP
= symbol_rootP
; symbolP
; symbolP
= symbol_next (symbolP
))
555 if (S_GET_NAME (symbolP
))
556 append (where
, S_GET_NAME (symbolP
),
557 (unsigned long) (strlen (S_GET_NAME (symbolP
)) + 1));
558 } /* walk symbol chain */
562 #define AOUT_VERSION 0
566 obj_pre_write_hook (headers
)
567 object_headers
*headers
;
569 H_SET_DYNAMIC (headers
, 0);
570 H_SET_VERSION (headers
, AOUT_VERSION
);
571 H_SET_MACHTYPE (headers
, AOUT_MACHTYPE
);
572 tc_aout_pre_write_hook (headers
);
575 #endif /* ! BFD_ASSEMBLER */
579 /* Support for an AOUT emulation. */
581 static void aout_pop_insert
PARAMS ((void));
582 static int obj_aout_s_get_other
PARAMS ((symbolS
*));
583 static void obj_aout_s_set_other
PARAMS ((symbolS
*, int));
584 static int obj_aout_s_get_desc
PARAMS ((symbolS
*));
585 static void obj_aout_s_set_desc
PARAMS ((symbolS
*, int));
586 static int obj_aout_s_get_type
PARAMS ((symbolS
*));
587 static void obj_aout_s_set_type
PARAMS ((symbolS
*, int));
588 static int obj_aout_separate_stab_sections
PARAMS ((void));
589 static int obj_aout_sec_sym_ok_for_reloc
PARAMS ((asection
*));
590 static void obj_aout_process_stab
PARAMS ((segT
, int, const char *, int, int, int));
595 pop_insert (aout_pseudo_table
);
599 obj_aout_s_get_other (sym
)
602 return aout_symbol (symbol_get_bfdsym (sym
))->other
;
606 obj_aout_s_set_other (sym
, o
)
610 aout_symbol (symbol_get_bfdsym (sym
))->other
= o
;
614 obj_aout_sec_sym_ok_for_reloc (sec
)
615 asection
*sec ATTRIBUTE_UNUSED
;
617 return obj_sec_sym_ok_for_reloc (sec
);
621 obj_aout_process_stab (seg
, w
, s
, t
, o
, d
)
622 segT seg ATTRIBUTE_UNUSED
;
629 aout_process_stab (w
, s
, t
, o
, d
);
633 obj_aout_s_get_desc (sym
)
636 return aout_symbol (symbol_get_bfdsym (sym
))->desc
;
640 obj_aout_s_set_desc (sym
, d
)
644 aout_symbol (symbol_get_bfdsym (sym
))->desc
= d
;
648 obj_aout_s_get_type (sym
)
651 return aout_symbol (symbol_get_bfdsym (sym
))->type
;
655 obj_aout_s_set_type (sym
, t
)
659 aout_symbol (symbol_get_bfdsym (sym
))->type
= t
;
663 obj_aout_separate_stab_sections ()
668 /* When changed, make sure these table entries match the single-format
669 definitions in obj-aout.h. */
670 const struct format_ops aout_format_ops
=
672 bfd_target_aout_flavour
,
673 1, /* dfl_leading_underscore */
674 0, /* emit_section_symbols */
677 obj_aout_frob_symbol
,
679 0, /* frob_file_before_adjust */
680 obj_aout_frob_file_before_fix
,
681 0, /* frob_file_after_relocs */
686 obj_aout_s_get_other
,
687 obj_aout_s_set_other
,
692 0, /* copy_symbol_attributes */
693 0, /* generate_asm_lineno */
694 obj_aout_process_stab
,
695 obj_aout_separate_stab_sections
,
696 0, /* init_stab_section */
697 obj_aout_sec_sym_ok_for_reloc
,
699 0, /* ecoff_set_ext */
700 0, /* read_begin_hook */
701 0 /* symbol_new_hook */
703 #endif /* BFD_ASSEMBLER */