1 /* a.out object file format
2 Copyright (C) 1989, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 2000
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 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 */
106 obj_aout_frob_symbol (sym
, punt
)
108 int *punt ATTRIBUTE_UNUSED
;
112 int desc
, type
, other
;
114 flags
= symbol_get_bfdsym (sym
)->flags
;
115 desc
= aout_symbol (symbol_get_bfdsym (sym
))->desc
;
116 type
= aout_symbol (symbol_get_bfdsym (sym
))->type
;
117 other
= aout_symbol (symbol_get_bfdsym (sym
))->other
;
118 sec
= S_GET_SEGMENT (sym
);
120 /* Only frob simple symbols this way right now. */
121 if (! (type
& ~ (N_TYPE
| N_EXT
)))
123 if (type
== (N_UNDF
| N_EXT
)
124 && sec
== &bfd_abs_section
)
126 sec
= bfd_und_section_ptr
;
127 S_SET_SEGMENT (sym
, sec
);
130 if ((type
& N_TYPE
) != N_INDR
131 && (type
& N_TYPE
) != N_SETA
132 && (type
& N_TYPE
) != N_SETT
133 && (type
& N_TYPE
) != N_SETD
134 && (type
& N_TYPE
) != N_SETB
136 && (sec
== &bfd_abs_section
137 || sec
== &bfd_und_section
))
139 if (flags
& BSF_EXPORT
)
142 switch (type
& N_TYPE
)
148 /* Set the debugging flag for constructor symbols so that
149 BFD leaves them alone. */
150 symbol_get_bfdsym (sym
)->flags
|= BSF_DEBUGGING
;
152 /* You can't put a common symbol in a set. The way a set
153 element works is that the symbol has a definition and a
154 name, and the linker adds the definition to the set of
155 that name. That does not work for a common symbol,
156 because the linker can't tell which common symbol the
157 user means. FIXME: Using as_bad here may be
158 inappropriate, since the user may want to force a
159 particular type without regard to the semantics of sets;
160 on the other hand, we certainly don't want anybody to be
161 mislead into thinking that their code will work. */
162 if (S_IS_COMMON (sym
))
163 as_bad (_("Attempt to put a common symbol into set %s"),
165 /* Similarly, you can't put an undefined symbol in a set. */
166 else if (! S_IS_DEFINED (sym
))
167 as_bad (_("Attempt to put an undefined symbol into set %s"),
172 /* Put indirect symbols in the indirect section. */
173 S_SET_SEGMENT (sym
, bfd_ind_section_ptr
);
174 symbol_get_bfdsym (sym
)->flags
|= BSF_INDIRECT
;
177 symbol_get_bfdsym (sym
)->flags
|= BSF_EXPORT
;
178 symbol_get_bfdsym (sym
)->flags
&=~ BSF_LOCAL
;
182 /* Mark warning symbols. */
183 symbol_get_bfdsym (sym
)->flags
|= BSF_WARNING
;
189 symbol_get_bfdsym (sym
)->flags
|= BSF_DEBUGGING
;
192 aout_symbol (symbol_get_bfdsym (sym
))->type
= type
;
194 /* Double check weak symbols. */
197 if (S_IS_COMMON (sym
))
198 as_bad (_("Symbol `%s' can not be both weak and common"),
204 obj_aout_frob_file ()
206 /* Relocation processing may require knowing the VMAs of the sections.
207 Since writing to a section will cause the BFD back end to compute the
208 VMAs, fake it out here.... */
211 if (bfd_section_size (stdoutput
, text_section
) != 0)
213 x
= bfd_set_section_contents (stdoutput
, text_section
, &b
, (file_ptr
) 0,
216 else if (bfd_section_size (stdoutput
, data_section
) != 0)
218 x
= bfd_set_section_contents (stdoutput
, data_section
, &b
, (file_ptr
) 0,
224 #else /* ! BFD_ASSEMBLER */
231 * Crawl along a fixS chain. Emit the segment's relocations.
234 obj_emit_relocations (where
, fixP
, segment_address_in_file
)
236 fixS
*fixP
; /* Fixup chain for this segment. */
237 relax_addressT segment_address_in_file
;
239 for (; fixP
; fixP
= fixP
->fx_next
)
240 if (fixP
->fx_done
== 0)
244 sym
= fixP
->fx_addsy
;
245 while (sym
->sy_value
.X_op
== O_symbol
246 && (! S_IS_DEFINED (sym
) || S_IS_COMMON (sym
)))
247 sym
= sym
->sy_value
.X_add_symbol
;
248 fixP
->fx_addsy
= sym
;
250 if (! sym
->sy_resolved
&& ! S_IS_DEFINED (sym
))
255 if (expr_symbol_where (sym
, &file
, &line
))
256 as_bad_where (file
, line
, _("unresolved relocation"));
258 as_bad (_("bad relocation: symbol `%s' not in symbol table"),
262 tc_aout_fix_to_chars (*where
, fixP
, segment_address_in_file
);
263 *where
+= md_reloc_size
;
267 #ifndef obj_header_append
268 /* Aout file generation & utilities */
270 obj_header_append (where
, headers
)
272 object_headers
*headers
;
274 tc_headers_hook (headers
);
277 md_number_to_chars (*where
, headers
->header
.a_info
, sizeof (headers
->header
.a_info
));
278 *where
+= sizeof (headers
->header
.a_info
);
279 md_number_to_chars (*where
, headers
->header
.a_text
, sizeof (headers
->header
.a_text
));
280 *where
+= sizeof (headers
->header
.a_text
);
281 md_number_to_chars (*where
, headers
->header
.a_data
, sizeof (headers
->header
.a_data
));
282 *where
+= sizeof (headers
->header
.a_data
);
283 md_number_to_chars (*where
, headers
->header
.a_bss
, sizeof (headers
->header
.a_bss
));
284 *where
+= sizeof (headers
->header
.a_bss
);
285 md_number_to_chars (*where
, headers
->header
.a_syms
, sizeof (headers
->header
.a_syms
));
286 *where
+= sizeof (headers
->header
.a_syms
);
287 md_number_to_chars (*where
, headers
->header
.a_entry
, sizeof (headers
->header
.a_entry
));
288 *where
+= sizeof (headers
->header
.a_entry
);
289 md_number_to_chars (*where
, headers
->header
.a_trsize
, sizeof (headers
->header
.a_trsize
));
290 *where
+= sizeof (headers
->header
.a_trsize
);
291 md_number_to_chars (*where
, headers
->header
.a_drsize
, sizeof (headers
->header
.a_drsize
));
292 *where
+= sizeof (headers
->header
.a_drsize
);
294 #else /* CROSS_COMPILE */
296 append (where
, (char *) &headers
->header
, sizeof (headers
->header
));
297 #endif /* CROSS_COMPILE */
300 #endif /* ! defined (obj_header_append) */
303 obj_symbol_to_chars (where
, symbolP
)
307 md_number_to_chars ((char *) &(S_GET_OFFSET (symbolP
)), S_GET_OFFSET (symbolP
), sizeof (S_GET_OFFSET (symbolP
)));
308 md_number_to_chars ((char *) &(S_GET_DESC (symbolP
)), S_GET_DESC (symbolP
), sizeof (S_GET_DESC (symbolP
)));
309 md_number_to_chars ((char *) &(symbolP
->sy_symbol
.n_value
), S_GET_VALUE (symbolP
), sizeof (symbolP
->sy_symbol
.n_value
));
311 append (where
, (char *) &symbolP
->sy_symbol
, sizeof (obj_symbol_type
));
315 obj_emit_symbols (where
, symbol_rootP
)
317 symbolS
*symbol_rootP
;
321 /* Emit all symbols left in the symbol chain. */
322 for (symbolP
= symbol_rootP
; symbolP
; symbolP
= symbol_next (symbolP
))
324 /* Used to save the offset of the name. It is used to point
325 to the string in memory but must be a file offset. */
328 temp
= S_GET_NAME (symbolP
);
329 S_SET_OFFSET (symbolP
, symbolP
->sy_name_offset
);
331 /* Any symbol still undefined and is not a dbg symbol is made N_EXT. */
332 if (!S_IS_DEBUG (symbolP
) && !S_IS_DEFINED (symbolP
))
333 S_SET_EXTERNAL (symbolP
);
335 /* Adjust the type of a weak symbol. */
336 if (S_GET_WEAK (symbolP
))
338 switch (S_GET_TYPE (symbolP
))
340 case N_UNDF
: S_SET_TYPE (symbolP
, N_WEAKU
); break;
341 case N_ABS
: S_SET_TYPE (symbolP
, N_WEAKA
); break;
342 case N_TEXT
: S_SET_TYPE (symbolP
, N_WEAKT
); break;
343 case N_DATA
: S_SET_TYPE (symbolP
, N_WEAKD
); break;
344 case N_BSS
: S_SET_TYPE (symbolP
, N_WEAKB
); break;
345 default: as_bad (_("%s: bad type for weak symbol"), temp
); break;
349 obj_symbol_to_chars (where
, symbolP
);
350 S_SET_NAME (symbolP
, temp
);
354 #endif /* ! BFD_ASSEMBLER */
357 obj_aout_line (ignore
)
358 int ignore ATTRIBUTE_UNUSED
;
360 /* Assume delimiter is part of expression.
361 BSD4.2 as fails with delightful bug, so we
362 are not being incompatible here. */
363 new_logical_line ((char *) NULL
, (int) (get_absolute_expression ()));
364 demand_empty_rest_of_line ();
365 } /* obj_aout_line() */
367 /* Handle .weak. This is a GNU extension. */
370 obj_aout_weak (ignore
)
371 int ignore ATTRIBUTE_UNUSED
;
379 name
= input_line_pointer
;
380 c
= get_symbol_end ();
381 symbolP
= symbol_find_or_make (name
);
382 *input_line_pointer
= c
;
384 S_SET_WEAK (symbolP
);
387 input_line_pointer
++;
389 if (*input_line_pointer
== '\n')
394 demand_empty_rest_of_line ();
397 /* Handle .type. On {Net,Open}BSD, this is used to set the n_other field,
398 which is then apparently used when doing dynamic linking. Older
399 versions of gas ignored the .type pseudo-op, so we also ignore it if
400 we can't parse it. */
403 obj_aout_type (ignore
)
404 int ignore ATTRIBUTE_UNUSED
;
410 name
= input_line_pointer
;
411 c
= get_symbol_end ();
412 sym
= symbol_find_or_make (name
);
413 *input_line_pointer
= c
;
415 if (*input_line_pointer
== ',')
417 ++input_line_pointer
;
419 if (*input_line_pointer
== '@')
421 ++input_line_pointer
;
422 if (strncmp (input_line_pointer
, "object", 6) == 0)
424 aout_symbol (symbol_get_bfdsym (sym
))->other
= 1;
426 S_SET_OTHER (sym
, 1);
428 else if (strncmp (input_line_pointer
, "function", 8) == 0)
430 aout_symbol (symbol_get_bfdsym (sym
))->other
= 2;
432 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 pusing data into text */
470 resolve_symbol_value (symbolP
, 1);
472 /* Skip symbols which were equated to undefined or common
474 if (symbolP
->sy_value
.X_op
== O_symbol
475 && (! S_IS_DEFINED (symbolP
) || S_IS_COMMON (symbolP
)))
477 *symbolPP
= symbol_next (symbolP
);
481 /* OK, here is how we decide which symbols go out into the brave
482 new symtab. Symbols that do are:
484 * symbols with no name (stabd's?)
485 * symbols with debug info in their N_TYPE
487 Symbols that don't are:
488 * symbols that are registers
489 * symbols with \1 as their 3rd character (numeric labels)
490 * "local labels" as defined by S_LOCAL_NAME(name) if the -L
491 switch was passed to gas.
493 All other symbols are output. We complain if a deleted
494 symbol was marked external. */
497 if (!S_IS_REGISTER (symbolP
)
498 && (!S_GET_NAME (symbolP
)
499 || S_IS_DEBUG (symbolP
)
500 || !S_IS_DEFINED (symbolP
)
501 || S_IS_EXTERNAL (symbolP
)
502 || (S_GET_NAME (symbolP
)[0] != '\001'
503 && (flag_keep_locals
|| !S_LOCAL_NAME (symbolP
)))))
505 symbolP
->sy_number
= symbol_number
++;
507 /* The + 1 after strlen account for the \0 at the
508 end of each string */
509 if (!S_IS_STABD (symbolP
))
512 symbolP
->sy_name_offset
= string_byte_count
;
513 string_byte_count
+= strlen (S_GET_NAME (symbolP
)) + 1;
515 else /* .Stabd case. */
516 symbolP
->sy_name_offset
= 0;
517 symbolPP
= &symbolP
->sy_next
;
521 if (S_IS_EXTERNAL (symbolP
) || !S_IS_DEFINED (symbolP
))
522 /* This warning should never get triggered any more.
523 Well, maybe if you're doing twisted things with
526 as_bad (_("Local symbol %s never defined."), decode_local_label_name (S_GET_NAME (symbolP
)));
529 /* Unhook it from the chain */
530 *symbolPP
= symbol_next (symbolP
);
531 } /* if this symbol should be in the output */
532 } /* for each symbol */
534 H_SET_SYMBOL_TABLE_SIZE (headers
, symbol_number
);
538 * Find strings by crawling along symbol table chain.
542 obj_emit_strings (where
)
548 /* Gotta do md_ byte-ordering stuff for string_byte_count first - KWK */
549 md_number_to_chars (*where
, string_byte_count
, sizeof (string_byte_count
));
550 *where
+= sizeof (string_byte_count
);
551 #else /* CROSS_COMPILE */
552 append (where
, (char *) &string_byte_count
, (unsigned long) sizeof (string_byte_count
));
553 #endif /* CROSS_COMPILE */
555 for (symbolP
= symbol_rootP
; symbolP
; symbolP
= symbol_next (symbolP
))
557 if (S_GET_NAME (symbolP
))
558 append (&next_object_file_charP
, S_GET_NAME (symbolP
),
559 (unsigned long) (strlen (S_GET_NAME (symbolP
)) + 1));
560 } /* walk symbol chain */
564 #define AOUT_VERSION 0
568 obj_pre_write_hook (headers
)
569 object_headers
*headers
;
571 H_SET_DYNAMIC (headers
, 0);
572 H_SET_VERSION (headers
, AOUT_VERSION
);
573 H_SET_MACHTYPE (headers
, AOUT_MACHTYPE
);
574 tc_aout_pre_write_hook (headers
);
580 /* Strip out the section name */
582 char *section_name_end
;
589 section_name
= input_line_pointer
;
590 c
= get_symbol_end ();
591 section_name_end
= input_line_pointer
;
593 len
= section_name_end
- section_name
;
594 input_line_pointer
++;
595 save
= input_line_pointer
;
600 exp
= get_absolute_expression ();
602 else if (*input_line_pointer
== ',')
604 input_line_pointer
++;
605 exp
= get_absolute_expression ();
609 input_line_pointer
= save
;
614 as_bad (_("subsegment index too high"));
617 if (strcmp (section_name
, ".text") == 0)
619 subseg_set (SEG_TEXT
, (subsegT
) exp
);
622 if (strcmp (section_name
, ".data") == 0)
624 if (flag_readonly_data_in_text
)
625 subseg_set (SEG_TEXT
, (subsegT
) exp
+ 1000);
627 subseg_set (SEG_DATA
, (subsegT
) exp
);
630 *section_name_end
= c
;
633 #endif /* ! BFD_ASSEMBLER */
637 /* Support for an AOUT emulation. */
639 static void aout_pop_insert
PARAMS ((void));
640 static int obj_aout_s_get_other
PARAMS ((symbolS
*));
641 static void obj_aout_s_set_other
PARAMS ((symbolS
*, int));
642 static int obj_aout_s_get_desc
PARAMS ((symbolS
*));
643 static void obj_aout_s_set_desc
PARAMS ((symbolS
*, int));
644 static int obj_aout_s_get_type
PARAMS ((symbolS
*));
645 static void obj_aout_s_set_type
PARAMS ((symbolS
*, int));
646 static int obj_aout_separate_stab_sections
PARAMS ((void));
647 static int obj_aout_sec_sym_ok_for_reloc
PARAMS ((asection
*));
648 static void obj_aout_process_stab
PARAMS ((segT
, int, const char *, int, int, int));
653 pop_insert (aout_pseudo_table
);
657 obj_aout_s_get_other (sym
)
660 return aout_symbol (symbol_get_bfdsym (sym
))->other
;
664 obj_aout_s_set_other (sym
, o
)
668 aout_symbol (symbol_get_bfdsym (sym
))->other
= o
;
672 obj_aout_sec_sym_ok_for_reloc (sec
)
673 asection
*sec ATTRIBUTE_UNUSED
;
675 return obj_sec_sym_ok_for_reloc (sec
);
679 obj_aout_process_stab (seg
, w
, s
, t
, o
, d
)
680 segT seg ATTRIBUTE_UNUSED
;
687 aout_process_stab (w
, s
, t
, o
, d
);
691 obj_aout_s_get_desc (sym
)
694 return aout_symbol (symbol_get_bfdsym (sym
))->desc
;
698 obj_aout_s_set_desc (sym
, d
)
702 aout_symbol (symbol_get_bfdsym (sym
))->desc
= d
;
706 obj_aout_s_get_type (sym
)
709 return aout_symbol (symbol_get_bfdsym (sym
))->type
;
713 obj_aout_s_set_type (sym
, t
)
717 aout_symbol (symbol_get_bfdsym (sym
))->type
= t
;
721 obj_aout_separate_stab_sections ()
726 /* When changed, make sure these table entries match the single-format
727 definitions in obj-aout.h. */
728 const struct format_ops aout_format_ops
=
730 bfd_target_aout_flavour
,
731 1, /* dfl_leading_underscore */
732 0, /* emit_section_symbols */
735 obj_aout_frob_symbol
,
737 0, /* frob_file_after_relocs */
742 obj_aout_s_get_other
,
743 obj_aout_s_set_other
,
748 0, /* copy_symbol_attributes */
749 0, /* generate_asm_lineno */
750 obj_aout_process_stab
,
751 obj_aout_separate_stab_sections
,
752 0, /* init_stab_section */
753 obj_aout_sec_sym_ok_for_reloc
,
755 0, /* ecoff_set_ext */
756 0, /* read_begin_hook */
757 0 /* symbol_new_hook */
761 /* end of obj-aout.c */