1 /* a.out object file format
2 Copyright (C) 1989, 90, 91, 92, 93, 94, 95, 96, 97, 98, 1999
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
25 #include "aout/aout64.h"
30 /* in: segT out: N_TYPE bits */
31 const short seg_N_TYPE
[] =
39 N_UNDF
, /* expression */
43 N_REGISTER
, /* register */
46 const segT N_TYPE_seg
[N_TYPE
+ 2] =
47 { /* N_TYPE == 0x1E = 32-2 */
48 SEG_UNKNOWN
, /* N_UNDF == 0 */
50 SEG_ABSOLUTE
, /* N_ABS == 2 */
52 SEG_TEXT
, /* N_TEXT == 4 */
54 SEG_DATA
, /* N_DATA == 6 */
56 SEG_BSS
, /* N_BSS == 8 */
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
, SEG_GOOF
, SEG_GOOF
, SEG_GOOF
, SEG_GOOF
,
60 SEG_GOOF
, SEG_GOOF
, SEG_GOOF
, SEG_GOOF
,
61 SEG_REGISTER
, /* dummy N_REGISTER for regs = 30 */
66 static void obj_aout_line
PARAMS ((int));
67 static void obj_aout_weak
PARAMS ((int));
68 static void obj_aout_type
PARAMS ((int));
70 const pseudo_typeS obj_pseudo_table
[] =
72 {"line", obj_aout_line
, 0}, /* source code line number */
73 {"ln", obj_aout_line
, 0}, /* coff line number that we use anyway */
75 {"weak", obj_aout_weak
, 0}, /* mark symbol as weak. */
77 {"type", obj_aout_type
, 0},
79 /* coff debug pseudos (ignored) */
82 {"endef", s_ignore
, 0},
83 {"ident", s_ignore
, 0},
84 {"line", s_ignore
, 0},
87 {"size", s_ignore
, 0},
90 {"version", s_ignore
, 0},
92 {"optim", s_ignore
, 0}, /* For sun386i cc (?) */
95 {"ABORT", s_abort
, 0},
97 {NULL
} /* end sentinel */
98 }; /* obj_pseudo_table */
104 obj_aout_frob_symbol (sym
, punt
)
110 int desc
, type
, other
;
112 flags
= symbol_get_bfdsym (sym
)->flags
;
113 desc
= S_GET_DESC (sym
);
114 type
= S_GET_TYPE (sym
);
115 other
= S_GET_OTHER (sym
);
116 sec
= S_GET_SEGMENT (sym
);
118 /* Only frob simple symbols this way right now. */
119 if (! (type
& ~ (N_TYPE
| N_EXT
)))
121 if (type
== (N_UNDF
| N_EXT
)
122 && sec
== &bfd_abs_section
)
124 sec
= bfd_und_section_ptr
;
125 S_SET_SEGMENT (sym
, sec
);
128 if ((type
& N_TYPE
) != N_INDR
129 && (type
& N_TYPE
) != N_SETA
130 && (type
& N_TYPE
) != N_SETT
131 && (type
& N_TYPE
) != N_SETD
132 && (type
& N_TYPE
) != N_SETB
134 && (sec
== &bfd_abs_section
135 || sec
== &bfd_und_section
))
137 if (flags
& BSF_EXPORT
)
140 switch (type
& N_TYPE
)
146 /* Set the debugging flag for constructor symbols so that
147 BFD leaves them alone. */
148 symbol_get_bfdsym (sym
)->flags
|= BSF_DEBUGGING
;
150 /* You can't put a common symbol in a set. The way a set
151 element works is that the symbol has a definition and a
152 name, and the linker adds the definition to the set of
153 that name. That does not work for a common symbol,
154 because the linker can't tell which common symbol the
155 user means. FIXME: Using as_bad here may be
156 inappropriate, since the user may want to force a
157 particular type without regard to the semantics of sets;
158 on the other hand, we certainly don't want anybody to be
159 mislead into thinking that their code will work. */
160 if (S_IS_COMMON (sym
))
161 as_bad (_("Attempt to put a common symbol into set %s"),
163 /* Similarly, you can't put an undefined symbol in a set. */
164 else if (! S_IS_DEFINED (sym
))
165 as_bad (_("Attempt to put an undefined symbol into set %s"),
170 /* Put indirect symbols in the indirect section. */
171 S_SET_SEGMENT (sym
, bfd_ind_section_ptr
);
172 symbol_get_bfdsym (sym
)->flags
|= BSF_INDIRECT
;
175 symbol_get_bfdsym (sym
)->flags
|= BSF_EXPORT
;
176 symbol_get_bfdsym (sym
)->flags
&=~ BSF_LOCAL
;
180 /* Mark warning symbols. */
181 symbol_get_bfdsym (sym
)->flags
|= BSF_WARNING
;
187 symbol_get_bfdsym (sym
)->flags
|= BSF_DEBUGGING
;
190 S_SET_TYPE (sym
, type
);
192 /* Double check weak symbols. */
195 if (S_IS_COMMON (sym
))
196 as_bad (_("Symbol `%s' can not be both weak and common"),
202 obj_aout_frob_file ()
204 /* Relocation processing may require knowing the VMAs of the sections.
205 Since writing to a section will cause the BFD back end to compute the
206 VMAs, fake it out here.... */
209 if (bfd_section_size (stdoutput
, text_section
) != 0)
211 x
= bfd_set_section_contents (stdoutput
, text_section
, &b
, (file_ptr
) 0,
214 else if (bfd_section_size (stdoutput
, data_section
) != 0)
216 x
= bfd_set_section_contents (stdoutput
, data_section
, &b
, (file_ptr
) 0,
222 #else /* ! BFD_ASSEMBLER */
229 * Crawl along a fixS chain. Emit the segment's relocations.
232 obj_emit_relocations (where
, fixP
, segment_address_in_file
)
234 fixS
*fixP
; /* Fixup chain for this segment. */
235 relax_addressT segment_address_in_file
;
237 for (; fixP
; fixP
= fixP
->fx_next
)
238 if (fixP
->fx_done
== 0)
242 sym
= fixP
->fx_addsy
;
243 while (sym
->sy_value
.X_op
== O_symbol
244 && (! S_IS_DEFINED (sym
) || S_IS_COMMON (sym
)))
245 sym
= sym
->sy_value
.X_add_symbol
;
246 fixP
->fx_addsy
= sym
;
248 if (! sym
->sy_resolved
&& ! S_IS_DEFINED (sym
))
253 if (expr_symbol_where (sym
, &file
, &line
))
254 as_bad_where (file
, line
, _("unresolved relocation"));
256 as_bad (_("bad relocation: symbol `%s' not in symbol table"),
260 tc_aout_fix_to_chars (*where
, fixP
, segment_address_in_file
);
261 *where
+= md_reloc_size
;
265 #ifndef obj_header_append
266 /* Aout file generation & utilities */
268 obj_header_append (where
, headers
)
270 object_headers
*headers
;
272 tc_headers_hook (headers
);
275 md_number_to_chars (*where
, headers
->header
.a_info
, sizeof (headers
->header
.a_info
));
276 *where
+= sizeof (headers
->header
.a_info
);
277 md_number_to_chars (*where
, headers
->header
.a_text
, sizeof (headers
->header
.a_text
));
278 *where
+= sizeof (headers
->header
.a_text
);
279 md_number_to_chars (*where
, headers
->header
.a_data
, sizeof (headers
->header
.a_data
));
280 *where
+= sizeof (headers
->header
.a_data
);
281 md_number_to_chars (*where
, headers
->header
.a_bss
, sizeof (headers
->header
.a_bss
));
282 *where
+= sizeof (headers
->header
.a_bss
);
283 md_number_to_chars (*where
, headers
->header
.a_syms
, sizeof (headers
->header
.a_syms
));
284 *where
+= sizeof (headers
->header
.a_syms
);
285 md_number_to_chars (*where
, headers
->header
.a_entry
, sizeof (headers
->header
.a_entry
));
286 *where
+= sizeof (headers
->header
.a_entry
);
287 md_number_to_chars (*where
, headers
->header
.a_trsize
, sizeof (headers
->header
.a_trsize
));
288 *where
+= sizeof (headers
->header
.a_trsize
);
289 md_number_to_chars (*where
, headers
->header
.a_drsize
, sizeof (headers
->header
.a_drsize
));
290 *where
+= sizeof (headers
->header
.a_drsize
);
292 #else /* CROSS_COMPILE */
294 append (where
, (char *) &headers
->header
, sizeof (headers
->header
));
295 #endif /* CROSS_COMPILE */
298 #endif /* ! defined (obj_header_append) */
301 obj_symbol_to_chars (where
, symbolP
)
305 md_number_to_chars ((char *) &(S_GET_OFFSET (symbolP
)), S_GET_OFFSET (symbolP
), sizeof (S_GET_OFFSET (symbolP
)));
306 md_number_to_chars ((char *) &(S_GET_DESC (symbolP
)), S_GET_DESC (symbolP
), sizeof (S_GET_DESC (symbolP
)));
307 md_number_to_chars ((char *) &(symbolP
->sy_symbol
.n_value
), S_GET_VALUE (symbolP
), sizeof (symbolP
->sy_symbol
.n_value
));
309 append (where
, (char *) &symbolP
->sy_symbol
, sizeof (obj_symbol_type
));
313 obj_emit_symbols (where
, symbol_rootP
)
315 symbolS
*symbol_rootP
;
319 /* Emit all symbols left in the symbol chain. */
320 for (symbolP
= symbol_rootP
; symbolP
; symbolP
= symbol_next (symbolP
))
322 /* Used to save the offset of the name. It is used to point
323 to the string in memory but must be a file offset. */
326 temp
= S_GET_NAME (symbolP
);
327 S_SET_OFFSET (symbolP
, symbolP
->sy_name_offset
);
329 /* Any symbol still undefined and is not a dbg symbol is made N_EXT. */
330 if (!S_IS_DEBUG (symbolP
) && !S_IS_DEFINED (symbolP
))
331 S_SET_EXTERNAL (symbolP
);
333 /* Adjust the type of a weak symbol. */
334 if (S_GET_WEAK (symbolP
))
336 switch (S_GET_TYPE (symbolP
))
338 case N_UNDF
: S_SET_TYPE (symbolP
, N_WEAKU
); break;
339 case N_ABS
: S_SET_TYPE (symbolP
, N_WEAKA
); break;
340 case N_TEXT
: S_SET_TYPE (symbolP
, N_WEAKT
); break;
341 case N_DATA
: S_SET_TYPE (symbolP
, N_WEAKD
); break;
342 case N_BSS
: S_SET_TYPE (symbolP
, N_WEAKB
); break;
343 default: as_bad (_("%s: bad type for weak symbol"), temp
); break;
347 obj_symbol_to_chars (where
, symbolP
);
348 S_SET_NAME (symbolP
, temp
);
352 #endif /* ! BFD_ASSEMBLER */
355 obj_aout_line (ignore
)
358 /* Assume delimiter is part of expression.
359 BSD4.2 as fails with delightful bug, so we
360 are not being incompatible here. */
361 new_logical_line ((char *) NULL
, (int) (get_absolute_expression ()));
362 demand_empty_rest_of_line ();
363 } /* obj_aout_line() */
365 /* Handle .weak. This is a GNU extension. */
368 obj_aout_weak (ignore
)
377 name
= input_line_pointer
;
378 c
= get_symbol_end ();
379 symbolP
= symbol_find_or_make (name
);
380 *input_line_pointer
= c
;
382 S_SET_WEAK (symbolP
);
385 input_line_pointer
++;
387 if (*input_line_pointer
== '\n')
392 demand_empty_rest_of_line ();
395 /* Handle .type. On {Net,Open}BSD, this is used to set the n_other field,
396 which is then apparently used when doing dynamic linking. Older
397 versions ogas ignored the .type pseudo-op, so we also ignore it if
398 we can't parse it. */
401 obj_aout_type (ignore
)
408 name
= input_line_pointer
;
409 c
= get_symbol_end ();
410 sym
= symbol_find (name
);
411 *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)
423 S_SET_OTHER (sym
, 1);
424 else if (strncmp (input_line_pointer
, "function", 8) == 0)
425 S_SET_OTHER (sym
, 2);
430 /* Ignore everything else on the line. */
435 obj_read_begin_hook ()
439 #ifndef BFD_ASSEMBLER
442 obj_crawl_symbol_chain (headers
)
443 object_headers
*headers
;
447 int symbol_number
= 0;
449 tc_crawl_symbol_chain (headers
);
451 symbolPP
= &symbol_rootP
; /*->last symbol chain link. */
452 while ((symbolP
= *symbolPP
) != NULL
)
454 if (symbolP
->sy_mri_common
)
456 if (S_IS_EXTERNAL (symbolP
))
457 as_bad (_("%s: global symbols not supported in common sections"),
458 S_GET_NAME (symbolP
));
459 *symbolPP
= symbol_next (symbolP
);
463 if (flag_readonly_data_in_text
&& (S_GET_SEGMENT (symbolP
) == SEG_DATA
))
465 S_SET_SEGMENT (symbolP
, SEG_TEXT
);
466 } /* if pusing data into text */
468 resolve_symbol_value (symbolP
, 1);
470 /* Skip symbols which were equated to undefined or common
472 if (symbolP
->sy_value
.X_op
== O_symbol
473 && (! S_IS_DEFINED (symbolP
) || S_IS_COMMON (symbolP
)))
475 *symbolPP
= symbol_next (symbolP
);
479 /* OK, here is how we decide which symbols go out into the brave
480 new symtab. Symbols that do are:
482 * symbols with no name (stabd's?)
483 * symbols with debug info in their N_TYPE
485 Symbols that don't are:
486 * symbols that are registers
487 * symbols with \1 as their 3rd character (numeric labels)
488 * "local labels" as defined by S_LOCAL_NAME(name) if the -L
489 switch was passed to gas.
491 All other symbols are output. We complain if a deleted
492 symbol was marked external. */
495 if (!S_IS_REGISTER (symbolP
)
496 && (!S_GET_NAME (symbolP
)
497 || S_IS_DEBUG (symbolP
)
498 || !S_IS_DEFINED (symbolP
)
499 || S_IS_EXTERNAL (symbolP
)
500 || (S_GET_NAME (symbolP
)[0] != '\001'
501 && (flag_keep_locals
|| !S_LOCAL_NAME (symbolP
)))))
503 symbolP
->sy_number
= symbol_number
++;
505 /* The + 1 after strlen account for the \0 at the
506 end of each string */
507 if (!S_IS_STABD (symbolP
))
510 symbolP
->sy_name_offset
= string_byte_count
;
511 string_byte_count
+= strlen (S_GET_NAME (symbolP
)) + 1;
513 else /* .Stabd case. */
514 symbolP
->sy_name_offset
= 0;
515 symbolPP
= &symbolP
->sy_next
;
519 if (S_IS_EXTERNAL (symbolP
) || !S_IS_DEFINED (symbolP
))
520 /* This warning should never get triggered any more.
521 Well, maybe if you're doing twisted things with
524 as_bad (_("Local symbol %s never defined."), decode_local_label_name (S_GET_NAME (symbolP
)));
527 /* Unhook it from the chain */
528 *symbolPP
= symbol_next (symbolP
);
529 } /* if this symbol should be in the output */
530 } /* for each symbol */
532 H_SET_SYMBOL_TABLE_SIZE (headers
, symbol_number
);
536 * Find strings by crawling along symbol table chain.
540 obj_emit_strings (where
)
546 /* Gotta do md_ byte-ordering stuff for string_byte_count first - KWK */
547 md_number_to_chars (*where
, string_byte_count
, sizeof (string_byte_count
));
548 *where
+= sizeof (string_byte_count
);
549 #else /* CROSS_COMPILE */
550 append (where
, (char *) &string_byte_count
, (unsigned long) sizeof (string_byte_count
));
551 #endif /* CROSS_COMPILE */
553 for (symbolP
= symbol_rootP
; symbolP
; symbolP
= symbol_next (symbolP
))
555 if (S_GET_NAME (symbolP
))
556 append (&next_object_file_charP
, 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
);
578 /* Strip out the section name */
580 char *section_name_end
;
587 section_name
= input_line_pointer
;
588 c
= get_symbol_end ();
589 section_name_end
= input_line_pointer
;
591 len
= section_name_end
- section_name
;
592 input_line_pointer
++;
593 save
= input_line_pointer
;
598 exp
= get_absolute_expression ();
600 else if (*input_line_pointer
== ',')
602 input_line_pointer
++;
603 exp
= get_absolute_expression ();
607 input_line_pointer
= save
;
612 as_bad (_("subsegment index too high"));
615 if (strcmp (section_name
, ".text") == 0)
617 subseg_set (SEG_TEXT
, (subsegT
) exp
);
620 if (strcmp (section_name
, ".data") == 0)
622 if (flag_readonly_data_in_text
)
623 subseg_set (SEG_TEXT
, (subsegT
) exp
+ 1000);
625 subseg_set (SEG_DATA
, (subsegT
) exp
);
628 *section_name_end
= c
;
631 #endif /* ! BFD_ASSEMBLER */
633 /* end of obj-aout.c */