1 /* a.out object file format
2 Copyright 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1999, 2000, 2001
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 */
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 ()
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.... */
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 obj_header_append (where, headers)
271 object_headers *headers;
273 tc_headers_hook (headers);
276 md_number_to_chars (*where, headers->header.a_info, sizeof (headers->header.a_info));
277 *where += sizeof (headers->header.a_info);
278 md_number_to_chars (*where, headers->header.a_text, sizeof (headers->header.a_text));
279 *where += sizeof (headers->header.a_text);
280 md_number_to_chars (*where, headers->header.a_data, sizeof (headers->header.a_data));
281 *where += sizeof (headers->header.a_data);
282 md_number_to_chars (*where, headers->header.a_bss, sizeof (headers->header.a_bss));
283 *where += sizeof (headers->header.a_bss);
284 md_number_to_chars (*where, headers->header.a_syms, sizeof (headers->header.a_syms));
285 *where += sizeof (headers->header.a_syms);
286 md_number_to_chars (*where, headers->header.a_entry, sizeof (headers->header.a_entry));
287 *where += sizeof (headers->header.a_entry);
288 md_number_to_chars (*where, headers->header.a_trsize, sizeof (headers->header.a_trsize));
289 *where += sizeof (headers->header.a_trsize);
290 md_number_to_chars (*where, headers->header.a_drsize, sizeof (headers->header.a_drsize));
291 *where += sizeof (headers->header.a_drsize);
293 #else /* CROSS_COMPILE */
295 append (where, (char *) &headers->header, sizeof (headers->header));
296 #endif /* CROSS_COMPILE */
299 #endif /* ! defined (obj_header_append) */
302 obj_symbol_to_chars (where, symbolP)
306 md_number_to_chars ((char *) &(S_GET_OFFSET (symbolP)), S_GET_OFFSET (symbolP), sizeof (S_GET_OFFSET (symbolP)));
307 md_number_to_chars ((char *) &(S_GET_DESC (symbolP)), S_GET_DESC (symbolP), sizeof (S_GET_DESC (symbolP)));
308 md_number_to_chars ((char *) &(symbolP->sy_symbol.n_value), S_GET_VALUE (symbolP), sizeof (symbolP->sy_symbol.n_value));
310 append (where, (char *) &symbolP->sy_symbol, sizeof (obj_symbol_type));
314 obj_emit_symbols (where, symbol_rootP)
316 symbolS *symbol_rootP;
320 /* Emit all symbols left in the symbol chain. */
321 for (symbolP = symbol_rootP; symbolP; symbolP = symbol_next (symbolP))
323 /* Used to save the offset of the name. It is used to point
324 to the string in memory but must be a file offset. */
327 temp = S_GET_NAME (symbolP);
328 S_SET_OFFSET (symbolP, symbolP->sy_name_offset);
330 /* Any symbol still undefined and is not a dbg symbol is made N_EXT. */
331 if (!S_IS_DEBUG (symbolP) && !S_IS_DEFINED (symbolP))
332 S_SET_EXTERNAL (symbolP);
334 /* Adjust the type of a weak symbol. */
335 if (S_GET_WEAK (symbolP))
337 switch (S_GET_TYPE (symbolP))
339 case N_UNDF: S_SET_TYPE (symbolP, N_WEAKU); break;
340 case N_ABS: S_SET_TYPE (symbolP, N_WEAKA); break;
341 case N_TEXT: S_SET_TYPE (symbolP, N_WEAKT); break;
342 case N_DATA: S_SET_TYPE (symbolP, N_WEAKD); break;
343 case N_BSS: S_SET_TYPE (symbolP, N_WEAKB); break;
344 default: as_bad (_("%s: bad type for weak symbol"), temp); break;
348 obj_symbol_to_chars (where, symbolP);
349 S_SET_NAME (symbolP, temp);
353 #endif /* ! BFD_ASSEMBLER */
356 obj_aout_line (ignore)
357 int ignore ATTRIBUTE_UNUSED;
359 /* Assume delimiter is part of expression.
360 BSD4.2 as fails with delightful bug, so we
361 are not being incompatible here. */
362 new_logical_line ((char *) NULL, (int) (get_absolute_expression ()));
363 demand_empty_rest_of_line ();
364 } /* obj_aout_line() */
366 /* Handle .weak. This is a GNU extension. */
369 obj_aout_weak (ignore)
370 int ignore ATTRIBUTE_UNUSED;
378 name = input_line_pointer;
379 c = get_symbol_end ();
380 symbolP = symbol_find_or_make (name);
381 *input_line_pointer = c;
383 S_SET_WEAK (symbolP);
386 input_line_pointer++;
388 if (*input_line_pointer == '\n')
393 demand_empty_rest_of_line ();
396 /* Handle .type. On {Net,Open}BSD, this is used to set the n_other field,
397 which is then apparently used when doing dynamic linking. Older
398 versions of gas ignored the .type pseudo-op, so we also ignore it if
399 we can't parse it. */
402 obj_aout_type (ignore)
403 int ignore ATTRIBUTE_UNUSED;
409 name = input_line_pointer;
410 c = get_symbol_end ();
411 sym = symbol_find_or_make (name);
412 *input_line_pointer = c;
414 if (*input_line_pointer == ',')
416 ++input_line_pointer;
418 if (*input_line_pointer == '@')
420 ++input_line_pointer;
421 if (strncmp (input_line_pointer, "object", 6) == 0)
423 aout_symbol (symbol_get_bfdsym (sym))->other = 1;
425 S_SET_OTHER (sym, 1);
427 else if (strncmp (input_line_pointer, "function", 8) == 0)
429 aout_symbol (symbol_get_bfdsym (sym))->other = 2;
431 S_SET_OTHER (sym, 2);
436 /* Ignore everything else on the line. */
440 #ifndef BFD_ASSEMBLER
443 obj_crawl_symbol_chain (headers)
444 object_headers *headers;
448 int symbol_number = 0;
450 tc_crawl_symbol_chain (headers);
452 symbolPP = &symbol_rootP; /*->last symbol chain link. */
453 while ((symbolP = *symbolPP) != NULL)
455 if (symbolP->sy_mri_common)
457 if (S_IS_EXTERNAL (symbolP))
458 as_bad (_("%s: global symbols not supported in common sections"),
459 S_GET_NAME (symbolP));
460 *symbolPP = symbol_next (symbolP);
464 if (flag_readonly_data_in_text && (S_GET_SEGMENT (symbolP) == SEG_DATA))
466 S_SET_SEGMENT (symbolP, SEG_TEXT);
467 } /* if pusing data into text */
469 resolve_symbol_value (symbolP);
471 /* Skip symbols which were equated to undefined or common
473 if (symbolP->sy_value.X_op == O_symbol
474 && (! S_IS_DEFINED (symbolP) || S_IS_COMMON (symbolP)))
476 *symbolPP = symbol_next (symbolP);
480 /* OK, here is how we decide which symbols go out into the brave
481 new symtab. Symbols that do are:
483 * symbols with no name (stabd's?)
484 * symbols with debug info in their N_TYPE
486 Symbols that don't are:
487 * symbols that are registers
488 * symbols with \1 as their 3rd character (numeric labels)
489 * "local labels" as defined by S_LOCAL_NAME(name) if the -L
490 switch was passed to gas.
492 All other symbols are output. We complain if a deleted
493 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 */
635 /* Support for an AOUT emulation. */
637 static void aout_pop_insert PARAMS ((void));
638 static int obj_aout_s_get_other PARAMS ((symbolS *));
639 static void obj_aout_s_set_other PARAMS ((symbolS *, int));
640 static int obj_aout_s_get_desc PARAMS ((symbolS *));
641 static void obj_aout_s_set_desc PARAMS ((symbolS *, int));
642 static int obj_aout_s_get_type PARAMS ((symbolS *));
643 static void obj_aout_s_set_type PARAMS ((symbolS *, int));
644 static int obj_aout_separate_stab_sections PARAMS ((void));
645 static int obj_aout_sec_sym_ok_for_reloc PARAMS ((asection *));
646 static void obj_aout_process_stab PARAMS ((segT, int, const char *, int, int, int));
651 pop_insert (aout_pseudo_table);
655 obj_aout_s_get_other (sym)
658 return aout_symbol (symbol_get_bfdsym (sym))->other;
662 obj_aout_s_set_other (sym, o)
666 aout_symbol (symbol_get_bfdsym (sym))->other = o;
670 obj_aout_sec_sym_ok_for_reloc (sec)
671 asection *sec ATTRIBUTE_UNUSED;
673 return obj_sec_sym_ok_for_reloc (sec);
677 obj_aout_process_stab (seg, w, s, t, o, d)
678 segT seg ATTRIBUTE_UNUSED;
685 aout_process_stab (w, s, t, o, d);
689 obj_aout_s_get_desc (sym)
692 return aout_symbol (symbol_get_bfdsym (sym))->desc;
696 obj_aout_s_set_desc (sym, d)
700 aout_symbol (symbol_get_bfdsym (sym))->desc = d;
704 obj_aout_s_get_type (sym)
707 return aout_symbol (symbol_get_bfdsym (sym))->type;
711 obj_aout_s_set_type (sym, t)
715 aout_symbol (symbol_get_bfdsym (sym))->type = t;
719 obj_aout_separate_stab_sections ()
724 /* When changed, make sure these table entries match the single-format
725 definitions in obj-aout.h. */
726 const struct format_ops aout_format_ops =
728 bfd_target_aout_flavour,
729 1, /* dfl_leading_underscore */
730 0, /* emit_section_symbols */
733 obj_aout_frob_symbol,
735 0, /* frob_file_before_adjust */
736 0, /* frob_file_after_relocs */
741 obj_aout_s_get_other,
742 obj_aout_s_set_other,
747 0, /* copy_symbol_attributes */
748 0, /* generate_asm_lineno */
749 obj_aout_process_stab,
750 obj_aout_separate_stab_sections,
751 0, /* init_stab_section */
752 obj_aout_sec_sym_ok_for_reloc,
754 0, /* ecoff_set_ext */
755 0, /* read_begin_hook */
756 0 /* symbol_new_hook */