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)
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)
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)
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 ogas ignored the .type pseudo-op, so we also ignore it if
400 we can't parse it. */
403 obj_aout_type (ignore)
410 name = input_line_pointer;
411 c = get_symbol_end ();
412 sym = symbol_find (name);
413 *input_line_pointer = c;
417 if (*input_line_pointer == ',')
419 ++input_line_pointer;
421 if (*input_line_pointer == '@')
423 ++input_line_pointer;
424 if (strncmp (input_line_pointer, "object", 6) == 0)
426 aout_symbol (symbol_get_bfdsym (sym))->other = 1;
428 S_SET_OTHER (sym, 1);
430 else if (strncmp (input_line_pointer, "function", 8) == 0)
432 aout_symbol (symbol_get_bfdsym (sym))->other = 2;
434 S_SET_OTHER (sym, 2);
440 /* Ignore everything else on the line. */
444 #ifndef BFD_ASSEMBLER
447 obj_crawl_symbol_chain (headers)
448 object_headers *headers;
452 int symbol_number = 0;
454 tc_crawl_symbol_chain (headers);
456 symbolPP = &symbol_rootP; /*->last symbol chain link. */
457 while ((symbolP = *symbolPP) != NULL)
459 if (symbolP->sy_mri_common)
461 if (S_IS_EXTERNAL (symbolP))
462 as_bad (_("%s: global symbols not supported in common sections"),
463 S_GET_NAME (symbolP));
464 *symbolPP = symbol_next (symbolP);
468 if (flag_readonly_data_in_text && (S_GET_SEGMENT (symbolP) == SEG_DATA))
470 S_SET_SEGMENT (symbolP, SEG_TEXT);
471 } /* if pusing data into text */
473 resolve_symbol_value (symbolP, 1);
475 /* Skip symbols which were equated to undefined or common
477 if (symbolP->sy_value.X_op == O_symbol
478 && (! S_IS_DEFINED (symbolP) || S_IS_COMMON (symbolP)))
480 *symbolPP = symbol_next (symbolP);
484 /* OK, here is how we decide which symbols go out into the brave
485 new symtab. Symbols that do are:
487 * symbols with no name (stabd's?)
488 * symbols with debug info in their N_TYPE
490 Symbols that don't are:
491 * symbols that are registers
492 * symbols with \1 as their 3rd character (numeric labels)
493 * "local labels" as defined by S_LOCAL_NAME(name) if the -L
494 switch was passed to gas.
496 All other symbols are output. We complain if a deleted
497 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)
551 /* Gotta do md_ byte-ordering stuff for string_byte_count first - KWK */
552 md_number_to_chars (*where, string_byte_count, sizeof (string_byte_count));
553 *where += sizeof (string_byte_count);
554 #else /* CROSS_COMPILE */
555 append (where, (char *) &string_byte_count, (unsigned long) sizeof (string_byte_count));
556 #endif /* CROSS_COMPILE */
558 for (symbolP = symbol_rootP; symbolP; symbolP = symbol_next (symbolP))
560 if (S_GET_NAME (symbolP))
561 append (&next_object_file_charP, S_GET_NAME (symbolP),
562 (unsigned long) (strlen (S_GET_NAME (symbolP)) + 1));
563 } /* walk symbol chain */
567 #define AOUT_VERSION 0
571 obj_pre_write_hook (headers)
572 object_headers *headers;
574 H_SET_DYNAMIC (headers, 0);
575 H_SET_VERSION (headers, AOUT_VERSION);
576 H_SET_MACHTYPE (headers, AOUT_MACHTYPE);
577 tc_aout_pre_write_hook (headers);
583 /* Strip out the section name */
585 char *section_name_end;
592 section_name = input_line_pointer;
593 c = get_symbol_end ();
594 section_name_end = input_line_pointer;
596 len = section_name_end - section_name;
597 input_line_pointer++;
598 save = input_line_pointer;
603 exp = get_absolute_expression ();
605 else if (*input_line_pointer == ',')
607 input_line_pointer++;
608 exp = get_absolute_expression ();
612 input_line_pointer = save;
617 as_bad (_("subsegment index too high"));
620 if (strcmp (section_name, ".text") == 0)
622 subseg_set (SEG_TEXT, (subsegT) exp);
625 if (strcmp (section_name, ".data") == 0)
627 if (flag_readonly_data_in_text)
628 subseg_set (SEG_TEXT, (subsegT) exp + 1000);
630 subseg_set (SEG_DATA, (subsegT) exp);
633 *section_name_end = c;
636 #endif /* ! BFD_ASSEMBLER */
640 /* Support for an AOUT emulation. */
642 static void aout_pop_insert PARAMS ((void));
643 static int obj_aout_s_get_other PARAMS ((symbolS *));
644 static int obj_aout_s_get_desc PARAMS ((symbolS *));
649 pop_insert (aout_pseudo_table);
653 obj_aout_s_get_other (sym)
656 return aout_symbol (symbol_get_bfdsym (sym))->other;
660 obj_aout_s_get_desc (sym)
663 return aout_symbol (symbol_get_bfdsym (sym))->desc;
667 const struct format_ops aout_format_ops =
669 bfd_target_aout_flavour,
670 1, /* dfl_leading_underscore */
671 0, /* emit_section_symbols */
672 obj_aout_frob_symbol,
674 0, /* frob_file_after_relocs */
679 obj_aout_s_get_other,
681 0, /* copy_symbol_attributes */
682 0, /* generate_asm_lineno */
683 0, /* process_stab */
684 0, /* sec_sym_ok_for_reloc */
686 0, /* ecoff_set_ext */
687 0, /* read_begin_hook */
688 0 /* symbol_new_hook */
692 /* end of obj-aout.c */