913146e798f4e64475479a4eb8eb991e27adb0af
[deliverable/binutils-gdb.git] / gas / write.c
1 /* write.c - emit .o file
2 Copyright (C) 1986, 1987, 1990, 1991, 1992, 1993 Free Software Foundation, Inc.
3
4 This file is part of GAS, the GNU Assembler.
5
6 GAS is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2, or (at your option)
9 any later version.
10
11 GAS is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
15
16 You should have received a copy of the GNU General Public License
17 along with GAS; see the file COPYING. If not, write to
18 the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
19
20 /* This thing should be set up to do byteordering correctly. But... */
21
22 #include "as.h"
23 #include "subsegs.h"
24 #include "obstack.h"
25 #include "output-file.h"
26
27 /* The NOP_OPCODE is for the alignment fill value. Fill it with a nop
28 instruction so that the disassembler does not choke on it. */
29 #ifndef NOP_OPCODE
30 #define NOP_OPCODE 0x00
31 #endif
32
33 #ifndef WORKING_DOT_WORD
34 extern CONST int md_short_jump_size;
35 extern CONST int md_long_jump_size;
36 #endif
37
38 #ifndef BFD_ASSEMBLER
39
40 #ifndef MANY_SEGMENTS
41 struct frag *text_frag_root;
42 struct frag *data_frag_root;
43 struct frag *bss_frag_root;
44
45 struct frag *text_last_frag; /* Last frag in segment. */
46 struct frag *data_last_frag; /* Last frag in segment. */
47 static struct frag *bss_last_frag; /* Last frag in segment. */
48 #endif
49
50 static object_headers headers;
51 long string_byte_count;
52 static char *the_object_file;
53 char *next_object_file_charP; /* Tracks object file bytes. */
54
55 #ifndef OBJ_VMS
56 int magic_number_for_object_file = DEFAULT_MAGIC_NUMBER_FOR_OBJECT_FILE;
57 #endif
58
59 #endif /* BFD_ASSEMBLER */
60
61 #ifdef BFD_ASSEMBLER
62 static fixS *fix_new_internal PARAMS ((fragS *, int where, int size,
63 symbolS *add, symbolS *sub,
64 offsetT offset, int pcrel,
65 bfd_reloc_code_real_type r_type));
66 #else
67 static fixS *fix_new_internal PARAMS ((fragS *, int where, int size,
68 symbolS *add, symbolS *sub,
69 offsetT offset, int pcrel,
70 int r_type));
71 #endif
72 static long fixup_segment PARAMS ((fixS * fixP, segT this_segment_type));
73 static relax_addressT relax_align PARAMS ((relax_addressT addr, int align));
74 void relax_segment PARAMS ((struct frag * seg_frag_root, segT seg_type));
75
76 /*
77 * fix_new()
78 *
79 * Create a fixS in obstack 'notes'.
80 */
81 static fixS *
82 fix_new_internal (frag, where, size, add_symbol, sub_symbol, offset, pcrel,
83 r_type)
84 fragS *frag; /* Which frag? */
85 int where; /* Where in that frag? */
86 int size; /* 1, 2, or 4 usually. */
87 symbolS *add_symbol; /* X_add_symbol. */
88 symbolS *sub_symbol; /* X_op_symbol. */
89 offsetT offset; /* X_add_number. */
90 int pcrel; /* TRUE if PC-relative relocation. */
91 #ifdef BFD_ASSEMBLER
92 bfd_reloc_code_real_type r_type; /* Relocation type */
93 #else
94 int r_type; /* Relocation type */
95 #endif
96 {
97 fixS *fixP;
98
99 fixP = (fixS *) obstack_alloc (&notes, sizeof (fixS));
100
101 fixP->fx_frag = frag;
102 fixP->fx_where = where;
103 fixP->fx_size = size;
104 fixP->fx_addsy = add_symbol;
105 fixP->fx_subsy = sub_symbol;
106 fixP->fx_offset = offset;
107 fixP->fx_pcrel = pcrel;
108 #if defined(NEED_FX_R_TYPE) || defined (BFD_ASSEMBLER)
109 fixP->fx_r_type = r_type;
110 #endif
111 fixP->fx_im_disp = 0;
112 fixP->fx_pcrel_adjust = 0;
113 fixP->fx_bit_fixP = 0;
114 fixP->fx_addnumber = 0;
115
116 #ifdef TC_something
117 fixP->fx_bsr = 0;
118 #endif
119 #ifdef TC_I960
120 fixP->fx_callj = 0;
121 #endif
122
123 /* Usually, we want relocs sorted numerically, but while
124 comparing to older versions of gas that have relocs
125 reverse sorted, it is convenient to have this compile
126 time option. xoxorich. */
127
128 {
129
130 #ifdef BFD_ASSEMBLER
131 fixS **seg_fix_rootP = & (seg_info (now_seg)->fix_root);
132 fixS **seg_fix_tailP = & (seg_info (now_seg)->fix_tail);
133 #endif
134
135 #ifdef REVERSE_SORT_RELOCS
136
137 fixP->fx_next = *seg_fix_rootP;
138 *seg_fix_rootP = fixP;
139
140 #else /* REVERSE_SORT_RELOCS */
141
142 fixP->fx_next = NULL;
143
144 if (*seg_fix_tailP)
145 (*seg_fix_tailP)->fx_next = fixP;
146 else
147 *seg_fix_rootP = fixP;
148 *seg_fix_tailP = fixP;
149
150 #endif /* REVERSE_SORT_RELOCS */
151
152 }
153
154 return fixP;
155 }
156
157 /* Create a fixup relative to a symbol (plus a constant). */
158
159 fixS *
160 fix_new (frag, where, size, add_symbol, offset, pcrel, r_type)
161 fragS *frag; /* Which frag? */
162 int where; /* Where in that frag? */
163 short int size; /* 1, 2, or 4 usually. */
164 symbolS *add_symbol; /* X_add_symbol. */
165 offsetT offset; /* X_add_number. */
166 int pcrel; /* TRUE if PC-relative relocation. */
167 #ifdef BFD_ASSEMBLER
168 bfd_reloc_code_real_type r_type; /* Relocation type */
169 #else
170 int r_type; /* Relocation type */
171 #endif
172 {
173 return fix_new_internal (frag, where, size, add_symbol,
174 (symbolS *) NULL, offset, pcrel, r_type);
175 }
176
177 /* Create a fixup for an expression. Currently we only support fixups
178 for difference expressions. That is itself more than most object
179 file formats support anyhow. */
180
181 fixS *
182 fix_new_exp (frag, where, size, exp, pcrel, r_type)
183 fragS *frag; /* Which frag? */
184 int where; /* Where in that frag? */
185 short int size; /* 1, 2, or 4 usually. */
186 expressionS *exp; /* Expression. */
187 int pcrel; /* TRUE if PC-relative relocation. */
188 #ifdef BFD_ASSEMBLER
189 bfd_reloc_code_real_type r_type; /* Relocation type */
190 #else
191 int r_type; /* Relocation type */
192 #endif
193 {
194 symbolS *add = NULL;
195 symbolS *sub = NULL;
196 offsetT off = 0;
197
198 switch (exp->X_op)
199 {
200 case O_absent:
201 break;
202
203 case O_uminus:
204 sub = exp->X_add_symbol;
205 off = exp->X_add_number;
206 break;
207
208 case O_subtract:
209 sub = exp->X_op_symbol;
210 /* Fall through. */
211 case O_symbol:
212 add = exp->X_add_symbol;
213 /* Fall through. */
214 case O_constant:
215 off = exp->X_add_number;
216 break;
217
218 default:
219 as_bad ("expression too complex for fixup");
220 }
221
222 return fix_new_internal (frag, where, size, add, sub, off,
223 pcrel, r_type);
224 }
225
226 /* Append a string onto another string, bumping the pointer along. */
227 void
228 append (charPP, fromP, length)
229 char **charPP;
230 char *fromP;
231 unsigned long length;
232 {
233 /* Don't trust memcpy() of 0 chars. */
234 if (length == 0)
235 return;
236
237 memcpy (*charPP, fromP, (int) length);
238 *charPP += length;
239 }
240
241 #ifndef BFD_ASSEMBLER
242 int section_alignment[SEG_MAXIMUM_ORDINAL];
243 #endif
244
245 /*
246 * This routine records the largest alignment seen for each segment.
247 * If the beginning of the segment is aligned on the worst-case
248 * boundary, all of the other alignments within it will work. At
249 * least one object format really uses this info.
250 */
251 void
252 record_alignment (seg, align)
253 /* Segment to which alignment pertains */
254 segT seg;
255 /* Alignment, as a power of 2 (e.g., 1 => 2-byte boundary, 2 => 4-byte
256 boundary, etc.) */
257 int align;
258 {
259 #ifdef BFD_ASSEMBLER
260 if (align > bfd_get_section_alignment (stdoutput, seg))
261 bfd_set_section_alignment (stdoutput, seg, align);
262 #else
263 if (align > section_alignment[(int) seg])
264 section_alignment[(int) seg] = align;
265 #endif
266 }
267
268 #if defined (BFD_ASSEMBLER) || ! defined (BFD)
269
270 static fragS *
271 chain_frchains_together_1 (section, frchp)
272 segT section;
273 struct frchain *frchp;
274 {
275 fragS dummy, *prev_frag = &dummy;
276 for (; frchp && frchp->frch_seg == section; frchp = frchp->frch_next)
277 {
278 prev_frag->fr_next = frchp->frch_root;
279 prev_frag = frchp->frch_last;
280 }
281 prev_frag->fr_next = 0;
282 return prev_frag;
283 }
284
285 #endif
286
287 #ifdef BFD_ASSEMBLER
288
289 static void
290 chain_frchains_together (abfd, section, xxx)
291 bfd *abfd; /* unused */
292 segT section;
293 char *xxx; /* unused */
294 {
295 segment_info_type *info;
296
297 /* BFD may have introduced its own sections without using
298 subseg_new, so it is possible that seg_info is NULL. */
299 info = seg_info (section);
300 if (info != (segment_info_type *) NULL)
301 chain_frchains_together_1 (section, info->frchainP);
302 }
303
304 #endif
305
306 #if !defined (BFD) && !defined (BFD_ASSEMBLER)
307
308 void
309 remove_subsegs (head, seg, root, last)
310 frchainS *head;
311 int seg;
312 fragS **root;
313 fragS **last;
314 {
315 *root = head->frch_root;
316 *last = chain_frchains_together_1 (seg, head);
317 }
318
319 #endif /* BFD */
320
321 #ifdef BFD_ASSEMBLER
322 static void
323 cvt_frag_to_fill (sec, fragP)
324 segT sec;
325 fragS *fragP;
326 #else
327 static void
328 cvt_frag_to_fill (headers, fragP)
329 object_headers *headers;
330 fragS *fragP;
331 #endif
332 {
333 switch (fragP->fr_type)
334 {
335 case rs_align:
336 case rs_org:
337 #ifdef HANDLE_ALIGN
338 HANDLE_ALIGN (fragP);
339 #endif
340 fragP->fr_type = rs_fill;
341 know (fragP->fr_var == 1);
342 know (fragP->fr_next != NULL);
343
344 fragP->fr_offset = (fragP->fr_next->fr_address
345 - fragP->fr_address
346 - fragP->fr_fix);
347 break;
348
349 case rs_fill:
350 break;
351
352 case rs_machine_dependent:
353 #ifdef BFD_ASSEMBLER
354 md_convert_frag (stdoutput, sec, fragP);
355 #else
356 md_convert_frag (headers, fragP);
357 #endif
358
359 assert (fragP->fr_next == NULL || (fragP->fr_next->fr_address - fragP->fr_address == fragP->fr_fix));
360
361 /*
362 * After md_convert_frag, we make the frag into a ".space 0".
363 * Md_convert_frag() should set up any fixSs and constants
364 * required.
365 */
366 frag_wane (fragP);
367 break;
368
369 #ifndef WORKING_DOT_WORD
370 case rs_broken_word:
371 {
372 struct broken_word *lie;
373
374 if (fragP->fr_subtype)
375 {
376 fragP->fr_fix += md_short_jump_size;
377 for (lie = (struct broken_word *) (fragP->fr_symbol);
378 lie && lie->dispfrag == fragP;
379 lie = lie->next_broken_word)
380 if (lie->added == 1)
381 fragP->fr_fix += md_long_jump_size;
382 }
383 frag_wane (fragP);
384 }
385 break;
386 #endif
387
388 default:
389 BAD_CASE (fragP->fr_type);
390 break;
391 }
392 }
393
394 #ifdef BFD_ASSEMBLER
395 static void
396 relax_and_size_seg (abfd, sec, xxx)
397 bfd *abfd;
398 asection *sec;
399 char *xxx;
400 {
401 flagword flags;
402 fragS *fragp;
403 segment_info_type *seginfo;
404 int x;
405 valueT size, newsize;
406
407 flags = bfd_get_section_flags (abfd, sec);
408
409 seginfo = (segment_info_type *) bfd_get_section_userdata (abfd, sec);
410 if (seginfo && seginfo->frchainP)
411 {
412 relax_segment (seginfo->frchainP->frch_root, sec);
413 for (fragp = seginfo->frchainP->frch_root; fragp; fragp = fragp->fr_next)
414 cvt_frag_to_fill (sec, fragp);
415 for (fragp = seginfo->frchainP->frch_root;
416 fragp->fr_next;
417 fragp = fragp->fr_next)
418 /* walk to last elt */;
419 size = fragp->fr_address + fragp->fr_fix;
420 }
421 else
422 size = 0;
423 if (size > 0)
424 {
425 flags |= SEC_HAS_CONTENTS;
426 /* @@ This is just an approximation. */
427 if (seginfo->fix_root)
428 flags |= SEC_RELOC;
429 else
430 flags &= ~SEC_RELOC;
431 x = bfd_set_section_flags (abfd, sec, flags);
432 assert (x == true);
433 }
434 size = md_section_align (sec, size);
435 x = bfd_set_section_size (abfd, sec, size);
436 assert (x == true);
437
438 /* If the size had to be rounded up, add some padding in the last
439 non-empty frag. */
440 newsize = bfd_get_section_size_before_reloc (sec);
441 assert (newsize >= size);
442 if (size != newsize)
443 {
444 fragS *last = seginfo->frchainP->frch_last;
445 fragp = seginfo->frchainP->frch_root;
446 while (fragp->fr_next != last)
447 fragp = fragp->fr_next;
448 last->fr_address = size;
449 fragp->fr_offset += newsize - size;
450 }
451
452 #ifdef tc_frob_section
453 tc_frob_section (sec);
454 #endif
455 #ifdef obj_frob_section
456 obj_frob_section (sec);
457 #endif
458 }
459
460 #ifdef DEBUG2
461 static void
462 dump_section_relocs (abfd, sec, stream_)
463 bfd *abfd;
464 asection *sec;
465 char *stream_;
466 {
467 FILE *stream = (FILE *) stream_;
468 segment_info_type *seginfo = seg_info (sec);
469 fixS *fixp = seginfo->fix_root;
470
471 if (!fixp)
472 return;
473
474 fprintf (stream, "sec %s relocs:\n", sec->name);
475 while (fixp)
476 {
477 symbolS *s = fixp->fx_addsy;
478 if (s)
479 fprintf (stream, " %08x: %s(%s+%x)+%x\n", fixp,
480 S_GET_NAME (s), s->bsym->section->name,
481 S_GET_VALUE (s), fixp->fx_offset);
482 else
483 fprintf (stream, " %08x: type %d no sym\n", fixp, fixp->fx_r_type);
484 fixp = fixp->fx_next;
485 }
486 }
487 #else
488 #define dump_section_relocs(ABFD,SEC,STREAM) (void)(ABFD,SEC,STREAM)
489 #endif
490
491 static void
492 adjust_reloc_syms (abfd, sec, xxx)
493 bfd *abfd;
494 asection *sec;
495 char *xxx;
496 {
497 segment_info_type *seginfo = seg_info (sec);
498 fixS *fixp;
499
500 if (seginfo == NULL)
501 return;
502
503 dump_section_relocs (abfd, sec, stderr);
504
505 for (fixp = seginfo->fix_root; fixp; fixp = fixp->fx_next)
506 if (fixp->fx_addsy)
507 {
508 symbolS *sym = fixp->fx_addsy;
509 asection *symsec = sym->bsym->section;
510 segment_info_type *symseginfo = seg_info (symsec);
511
512 /* If it's one of these sections, assume the symbol is definitely
513 going to be output. */
514 if (symsec == &bfd_und_section
515 || symsec == &bfd_abs_section
516 || bfd_is_com_section (symsec))
517 continue;
518
519 /* Since we're reducing to section symbols, don't attempt to reduce
520 anything that's already using one. */
521 if (sym->bsym == symsec->symbol)
522 continue;
523
524 /* Is there some other reason we can't adjust this one? (E.g.,
525 call/bal links in i960-bout symbols.) */
526 #ifdef obj_fix_adjustable
527 if (! obj_fix_adjustable (fixp))
528 continue;
529 #endif
530 /* If the section symbol isn't going to be output, the relocs
531 at least should still work. If not, figure out what to do
532 when we run into that case. */
533 fixp->fx_offset += S_GET_VALUE (sym);
534 if (sym->sy_frag)
535 fixp->fx_offset += sym->sy_frag->fr_address;
536 if (symseginfo->sym)
537 fixp->fx_addsy = symseginfo->sym;
538 else
539 {
540 fixp->fx_addsy = symbol_find (symsec->name);
541 if (!fixp->fx_addsy)
542 {
543 fixp->fx_addsy = symbol_make (symsec->name);
544 fixp->fx_addsy->bsym = symsec->symbol;
545 }
546 symseginfo->sym = fixp->fx_addsy;
547 }
548 }
549
550 dump_section_relocs (abfd, sec, stderr);
551 }
552
553 static void
554 write_relocs (abfd, sec, xxx)
555 bfd *abfd;
556 asection *sec;
557 char *xxx;
558 {
559 segment_info_type *seginfo = seg_info (sec);
560 int i, n;
561 arelent **relocs;
562 fixS *fixp;
563
564 /* If seginfo is NULL, we did not create this section; don't do
565 anything with it. */
566 if (seginfo == NULL)
567 return;
568
569 fixup_segment (seginfo->fix_root, sec);
570
571 n = 0;
572 for (fixp = seginfo->fix_root; fixp; fixp = fixp->fx_next)
573 n++;
574
575 #ifndef RELOC_EXPANSION_POSSIBLE
576 /* Set up reloc information as well. */
577 relocs = (arelent **) bfd_alloc_by_size_t (stdoutput,
578 n * sizeof (arelent *));
579 memset ((char*)relocs, 0, n * sizeof (arelent*));
580
581 i = 0;
582 for (fixp = seginfo->fix_root; fixp != (fixS *) NULL; fixp = fixp->fx_next)
583 {
584 arelent *reloc;
585 extern arelent *tc_gen_reloc ();
586 char *data;
587 bfd_reloc_status_type s;
588
589 if (fixp->fx_addsy == 0)
590 {
591 /* @@ Need some other flag to indicate which have already
592 been performed... */
593 n--;
594 continue;
595 }
596 reloc = tc_gen_reloc (sec, fixp);
597 if (!reloc)
598 {
599 n--;
600 continue;
601 }
602 data = fixp->fx_frag->fr_literal + fixp->fx_where;
603 /* @@ Assumes max size of reloc is 4. */
604 if (fixp->fx_where + 4
605 > fixp->fx_frag->fr_fix + fixp->fx_frag->fr_offset)
606 abort ();
607 /* Pass bogus address so that when bfd_perform_relocation adds
608 `address' back in, it'll come up with `data', which is where
609 we want it to operate. */
610 s = bfd_perform_relocation (stdoutput, reloc, data - reloc->address,
611 sec, stdoutput);
612 switch (s)
613 {
614 case bfd_reloc_ok:
615 break;
616 default:
617 as_fatal ("bad return from bfd_perform_relocation");
618 }
619 relocs[i++] = reloc;
620 }
621 #else
622 n = n * MAX_RELOC_EXPANSION;
623 /* Set up reloc information as well. */
624 relocs = (arelent **) bfd_alloc_by_size_t (stdoutput,
625 n * sizeof (arelent *));
626
627 i = 0;
628 for (fixp = seginfo->fix_root; fixp != (fixS *) NULL; fixp = fixp->fx_next)
629 {
630 arelent **reloc;
631 extern arelent **tc_gen_reloc ();
632 char *data;
633 bfd_reloc_status_type s;
634 int j;
635
636 if (fixp->fx_addsy == 0)
637 {
638 /* @@ Need some other flag to indicate which have already
639 been performed... */
640 n--;
641 continue;
642 }
643 reloc = tc_gen_reloc (sec, fixp);
644
645 for (j = 0; reloc[j]; j++)
646 {
647 relocs[i++] = reloc[j];
648 assert(i <= n);
649 }
650 data = fixp->fx_frag->fr_literal + fixp->fx_where;
651 if (fixp->fx_where + 4
652 > fixp->fx_frag->fr_fix + fixp->fx_frag->fr_offset)
653 abort ();
654 for (j = 0; reloc[j]; j++)
655 {
656 s = bfd_perform_relocation (stdoutput, reloc[j], data - reloc[j]->address,
657 sec, stdoutput);
658 switch (s)
659 {
660 case bfd_reloc_ok:
661 break;
662 default:
663 as_fatal ("bad return from bfd_perform_relocation");
664 }
665 }
666 }
667 n = i;
668 #endif
669
670 if (n)
671 bfd_set_reloc (stdoutput, sec, relocs, n);
672 else
673 bfd_set_section_flags (abfd, sec,
674 bfd_get_section_flags (abfd, sec) & ~SEC_RELOC);
675 #ifdef DEBUG2
676 {
677 int i;
678 arelent *r;
679 asymbol *s;
680 fprintf (stderr, "relocs for sec %s\n", sec->name);
681 for (i = 0; i < n; i++)
682 {
683 r = relocs[i];
684 s = *r->sym_ptr_ptr;
685 fprintf (stderr, " reloc %2d @%08x off %4x : sym %-10s addend %x\n",
686 i, r, r->address, s->name, r->addend);
687 }
688 }
689 #endif
690 }
691
692 static void
693 write_contents (abfd, sec, xxx)
694 bfd *abfd;
695 asection *sec;
696 char *xxx;
697 {
698 segment_info_type *seginfo = seg_info (sec);
699 unsigned long offset = 0;
700 fragS *frags;
701
702 /* Write out the frags. */
703 if (! (bfd_get_section_flags (abfd, sec) & SEC_HAS_CONTENTS))
704 return;
705
706 for (frags = seginfo->frchainP->frch_root;
707 frags;
708 frags = frags->fr_next)
709 {
710 int x;
711 unsigned long fill_size;
712 char *fill_literal;
713 long count;
714
715 assert (frags->fr_type == rs_fill);
716 if (frags->fr_fix)
717 {
718 x = bfd_set_section_contents (stdoutput, sec,
719 frags->fr_literal, offset,
720 frags->fr_fix);
721 assert (x == true);
722 offset += frags->fr_fix;
723 }
724 fill_literal = frags->fr_literal + frags->fr_fix;
725 fill_size = frags->fr_var;
726 count = frags->fr_offset;
727 assert (count >= 0);
728 if (fill_size && count)
729 while (count--)
730 {
731 x = bfd_set_section_contents (stdoutput, sec,
732 fill_literal, offset,
733 (bfd_size_type) fill_size);
734 assert (x == true);
735 offset += fill_size;
736 }
737 }
738 }
739 #endif
740
741 #if defined(BFD_ASSEMBLER) || !defined (BFD)
742 static void
743 merge_data_into_text ()
744 {
745 #if defined(BFD_ASSEMBLER) || defined(MANY_SEGMENTS)
746 seg_info (text_section)->frchainP->frch_last->fr_next =
747 seg_info (data_section)->frchainP->frch_root;
748 seg_info (text_section)->frchainP->frch_last =
749 seg_info (data_section)->frchainP->frch_last;
750 seg_info (data_section)->frchainP = 0;
751 #else
752 fixS *tmp;
753
754 text_last_frag->fr_next = data_frag_root;
755 text_last_frag = data_last_frag;
756 data_last_frag = NULL;
757 data_frag_root = NULL;
758 if (text_fix_root)
759 {
760 for (tmp = text_fix_root; tmp->fx_next; tmp = tmp->fx_next);;
761 tmp->fx_next = data_fix_root;
762 text_fix_tail = data_fix_tail;
763 }
764 else
765 text_fix_root = data_fix_root;
766 data_fix_root = NULL;
767 #endif
768 }
769 #endif /* BFD_ASSEMBLER || ! BFD */
770
771 #if !defined (BFD_ASSEMBLER) && !defined (BFD)
772 static void
773 relax_and_size_all_segments ()
774 {
775 fragS *fragP;
776
777 relax_segment (text_frag_root, SEG_TEXT);
778 relax_segment (data_frag_root, SEG_DATA);
779 relax_segment (bss_frag_root, SEG_BSS);
780 /*
781 * Now the addresses of frags are correct within the segment.
782 */
783
784 know (text_last_frag->fr_type == rs_fill && text_last_frag->fr_offset == 0);
785 H_SET_TEXT_SIZE (&headers, text_last_frag->fr_address);
786 text_last_frag->fr_address = H_GET_TEXT_SIZE (&headers);
787
788 /*
789 * Join the 2 segments into 1 huge segment.
790 * To do this, re-compute every rn_address in the SEG_DATA frags.
791 * Then join the data frags after the text frags.
792 *
793 * Determine a_data [length of data segment].
794 */
795 if (data_frag_root)
796 {
797 register relax_addressT slide;
798
799 know ((text_last_frag->fr_type == rs_fill) && (text_last_frag->fr_offset == 0));
800
801 H_SET_DATA_SIZE (&headers, data_last_frag->fr_address);
802 data_last_frag->fr_address = H_GET_DATA_SIZE (&headers);
803 slide = H_GET_TEXT_SIZE (&headers); /* & in file of the data segment. */
804 #ifdef OBJ_BOUT
805 #define RoundUp(N,S) (((N)+(S)-1)&-(S))
806 /* For b.out: If the data section has a strict alignment
807 requirement, its load address in the .o file will be
808 rounded up from the size of the text section. These
809 two values are *not* the same! Similarly for the bss
810 section.... */
811 slide = RoundUp (slide, 1 << section_alignment[SEG_DATA]);
812 #endif
813
814 for (fragP = data_frag_root; fragP; fragP = fragP->fr_next)
815 {
816 fragP->fr_address += slide;
817 } /* for each data frag */
818
819 know (text_last_frag != 0);
820 text_last_frag->fr_next = data_frag_root;
821 }
822 else
823 {
824 H_SET_DATA_SIZE (&headers, 0);
825 }
826
827 #ifdef OBJ_BOUT
828 /* See above comments on b.out data section address. */
829 {
830 long bss_vma;
831 if (data_last_frag == 0)
832 bss_vma = H_GET_TEXT_SIZE (&headers);
833 else
834 bss_vma = data_last_frag->fr_address;
835 bss_vma = RoundUp (bss_vma, 1 << section_alignment[SEG_BSS]);
836 bss_address_frag.fr_address = bss_vma;
837 }
838 #else /* ! OBJ_BOUT */
839 bss_address_frag.fr_address = (H_GET_TEXT_SIZE (&headers) +
840 H_GET_DATA_SIZE (&headers));
841
842
843 /* Slide all the frags */
844 if (bss_frag_root)
845 {
846 relax_addressT slide = bss_address_frag.fr_address;
847
848 for (fragP = bss_frag_root; fragP; fragP = fragP->fr_next)
849 {
850 fragP->fr_address += slide;
851 } /* for each bss frag */
852 }
853
854 #endif /* ! OBJ_BOUT */
855
856 if (bss_last_frag)
857 H_SET_BSS_SIZE (&headers,
858 bss_last_frag->fr_address - bss_frag_root->fr_address);
859 else
860 H_SET_BSS_SIZE (&headers, 0);
861 }
862 #endif /* ! BFD_ASSEMBLER && ! BFD */
863
864 #if defined (BFD_ASSEMBLER) || !defined (BFD)
865
866 void
867 write_object_file ()
868 {
869 register struct frchain *frchainP; /* Track along all frchains. */
870 #if ! defined (BFD_ASSEMBLER) || ! defined (WORKING_DOT_WORD)
871 register fragS *fragP; /* Track along all frags. */
872 #endif
873 #if !defined (BFD_ASSEMBLER) && !defined (OBJ_VMS)
874 long object_file_size;
875 #endif
876
877 /* Do we really want to write it? */
878 {
879 int n_warns, n_errs;
880 n_warns = had_warnings ();
881 n_errs = had_errors ();
882 /* The -Z flag indicates that an object file should be generated,
883 regardless of warnings and errors. */
884 if (flagseen['Z'])
885 {
886 if (n_warns || n_errs)
887 as_warn ("%d error%s, %d warning%s, generating bad object file.\n",
888 n_errs, n_errs == 1 ? "" : "s",
889 n_warns, n_warns == 1 ? "" : "s");
890 }
891 else
892 {
893 if (n_errs)
894 as_fatal ("%d error%s, %d warning%s, no object file generated.\n",
895 n_errs, n_errs == 1 ? "" : "s",
896 n_warns, n_warns == 1 ? "" : "s");
897 }
898 }
899
900 #ifdef OBJ_VMS
901 /*
902 * Under VMS we try to be compatible with VAX-11 "C". Thus, we
903 * call a routine to check for the definition of the procedure
904 * "_main", and if so -- fix it up so that it can be program
905 * entry point.
906 */
907 VMS_Check_For_Main ();
908 #endif /* VMS */
909
910 /* After every sub-segment, we fake an ".align ...". This conforms to
911 BSD4.2 brane-damage. We then fake ".fill 0" because that is the kind of
912 frag that requires least thought. ".align" frags like to have a
913 following frag since that makes calculating their intended length
914 trivial.
915
916 @@ Is this really necessary?? */
917 #ifndef SUB_SEGMENT_ALIGN
918 #ifdef BFD_ASSEMBLER
919 #define SUB_SEGMENT_ALIGN(SEG) (0)
920 #else
921 #define SUB_SEGMENT_ALIGN(SEG) (2)
922 #endif
923 #endif
924 for (frchainP = frchain_root; frchainP; frchainP = frchainP->frch_next)
925 {
926 #ifdef BFD_ASSEMBLER
927 subseg_set (frchainP->frch_seg, frchainP->frch_subseg);
928 #else
929 subseg_new (frchainP->frch_seg, frchainP->frch_subseg);
930 #endif
931 frag_align (SUB_SEGMENT_ALIGN (now_seg), NOP_OPCODE);
932 /* frag_align will have left a new frag.
933 Use this last frag for an empty ".fill".
934
935 For this segment ...
936 Create a last frag. Do not leave a "being filled in frag". */
937 frag_wane (frag_now);
938 frag_now->fr_fix = 0;
939 know (frag_now->fr_next == NULL);
940 }
941
942 /* From now on, we don't care about sub-segments. Build one frag chain
943 for each segment. Linked thru fr_next. */
944
945 #ifdef BFD_ASSEMBLER
946 /* Remove the sections created by gas for its own purposes. */
947 {
948 asection **seclist, *sec;
949 seclist = &stdoutput->sections;
950 while (seclist && *seclist)
951 {
952 sec = *seclist;
953 while (sec == reg_section || sec == expr_section)
954 {
955 sec = sec->next;
956 *seclist = sec;
957 stdoutput->section_count--;
958 if (!sec)
959 break;
960 }
961 if (*seclist)
962 seclist = &(*seclist)->next;
963 }
964 }
965
966 bfd_map_over_sections (stdoutput, chain_frchains_together, (char *) 0);
967 #else
968 remove_subsegs (frchain_root, SEG_TEXT, &text_frag_root, &text_last_frag);
969 remove_subsegs (data0_frchainP, SEG_DATA, &data_frag_root, &data_last_frag);
970 remove_subsegs (bss0_frchainP, SEG_BSS, &bss_frag_root, &bss_last_frag);
971 #endif
972
973 /* We have two segments. If user gave -R flag, then we must put the
974 data frags into the text segment. Do this before relaxing so
975 we know to take advantage of -R and make shorter addresses. */
976 #if !defined (OBJ_AOUT) || defined (BFD_ASSEMBLER)
977 if (flagseen['R'])
978 {
979 merge_data_into_text ();
980 }
981 #endif
982
983 #ifdef BFD_ASSEMBLER
984 bfd_map_over_sections (stdoutput, relax_and_size_seg, (char *) 0);
985 #else
986 relax_and_size_all_segments ();
987 #endif /* BFD_ASSEMBLER */
988
989 #ifndef BFD_ASSEMBLER
990 /*
991 *
992 * Crawl the symbol chain.
993 *
994 * For each symbol whose value depends on a frag, take the address of
995 * that frag and subsume it into the value of the symbol.
996 * After this, there is just one way to lookup a symbol value.
997 * Values are left in their final state for object file emission.
998 * We adjust the values of 'L' local symbols, even if we do
999 * not intend to emit them to the object file, because their values
1000 * are needed for fix-ups.
1001 *
1002 * Unless we saw a -L flag, remove all symbols that begin with 'L'
1003 * from the symbol chain. (They are still pointed to by the fixes.)
1004 *
1005 * Count the remaining symbols.
1006 * Assign a symbol number to each symbol.
1007 * Count the number of string-table chars we will emit.
1008 * Put this info into the headers as appropriate.
1009 *
1010 */
1011 know (zero_address_frag.fr_address == 0);
1012 string_byte_count = sizeof (string_byte_count);
1013
1014 obj_crawl_symbol_chain (&headers);
1015
1016 if (string_byte_count == sizeof (string_byte_count))
1017 string_byte_count = 0;
1018
1019 H_SET_STRING_SIZE (&headers, string_byte_count);
1020
1021 /*
1022 * Addresses of frags now reflect addresses we use in the object file.
1023 * Symbol values are correct.
1024 * Scan the frags, converting any ".org"s and ".align"s to ".fill"s.
1025 * Also converting any machine-dependent frags using md_convert_frag();
1026 */
1027 subseg_change (SEG_TEXT, 0);
1028
1029 for (fragP = text_frag_root; fragP; fragP = fragP->fr_next)
1030 {
1031 cvt_frag_to_fill (&headers, fragP);
1032
1033 /* Some assert macros don't work with # directives mixed in. */
1034 #ifndef NDEBUG
1035 if (!(fragP->fr_next == NULL
1036 #ifdef OBJ_BOUT
1037 || fragP->fr_next == data_frag_root
1038 #endif
1039 || ((fragP->fr_next->fr_address - fragP->fr_address)
1040 == (fragP->fr_fix + fragP->fr_offset * fragP->fr_var))))
1041 abort ();
1042 #endif
1043 }
1044 #endif /* ! BFD_ASSEMBLER */
1045
1046 #ifndef WORKING_DOT_WORD
1047 {
1048 struct broken_word *lie;
1049 struct broken_word **prevP;
1050
1051 prevP = &broken_words;
1052 for (lie = broken_words; lie; lie = lie->next_broken_word)
1053 if (!lie->added)
1054 {
1055 expressionS exp;
1056
1057 exp.X_op = O_subtract;
1058 exp.X_add_symbol = lie->add;
1059 exp.X_op_symbol = lie->sub;
1060 exp.X_add_number = lie->addnum;
1061 #ifdef BFD_ASSEMBLER
1062 fix_new_exp (lie->frag,
1063 lie->word_goes_here - lie->frag->fr_literal,
1064 2, &exp, 0, BFD_RELOC_NONE);
1065 #else
1066 #if defined(TC_SPARC) || defined(TC_A29K) || defined(NEED_FX_R_TYPE)
1067 fix_new_exp (lie->frag,
1068 lie->word_goes_here - lie->frag->fr_literal,
1069 2, &exp, 0, NO_RELOC);
1070 #else
1071 #ifdef TC_NS32K
1072 fix_new_ns32k_exp (lie->frag,
1073 lie->word_goes_here - lie->frag->fr_literal,
1074 2, &exp, 0, 0, 2, 0, 0);
1075 #else
1076 fix_new_exp (lie->frag,
1077 lie->word_goes_here - lie->frag->fr_literal,
1078 2, &exp, 0, 0);
1079 #endif /* TC_NS32K */
1080 #endif /* TC_SPARC|TC_A29K|NEED_FX_R_TYPE */
1081 #endif /* BFD_ASSEMBLER */
1082 *prevP = lie->next_broken_word;
1083 }
1084 else
1085 prevP = &(lie->next_broken_word);
1086
1087 for (lie = broken_words; lie;)
1088 {
1089 struct broken_word *untruth;
1090 char *table_ptr;
1091 addressT table_addr;
1092 addressT from_addr, to_addr;
1093 int n, m;
1094
1095 fragP = lie->dispfrag;
1096
1097 /* Find out how many broken_words go here. */
1098 n = 0;
1099 for (untruth = lie; untruth && untruth->dispfrag == fragP; untruth = untruth->next_broken_word)
1100 if (untruth->added == 1)
1101 n++;
1102
1103 table_ptr = lie->dispfrag->fr_opcode;
1104 table_addr = lie->dispfrag->fr_address + (table_ptr - lie->dispfrag->fr_literal);
1105 /* Create the jump around the long jumps. This is a short
1106 jump from table_ptr+0 to table_ptr+n*long_jump_size. */
1107 from_addr = table_addr;
1108 to_addr = table_addr + md_short_jump_size + n * md_long_jump_size;
1109 md_create_short_jump (table_ptr, from_addr, to_addr, lie->dispfrag, lie->add);
1110 table_ptr += md_short_jump_size;
1111 table_addr += md_short_jump_size;
1112
1113 for (m = 0; lie && lie->dispfrag == fragP; m++, lie = lie->next_broken_word)
1114 {
1115 if (lie->added == 2)
1116 continue;
1117 /* Patch the jump table */
1118 /* This is the offset from ??? to table_ptr+0 */
1119 to_addr = table_addr - S_GET_VALUE (lie->sub);
1120 md_number_to_chars (lie->word_goes_here, to_addr, 2);
1121 for (untruth = lie->next_broken_word; untruth && untruth->dispfrag == fragP; untruth = untruth->next_broken_word)
1122 {
1123 if (untruth->use_jump == lie)
1124 md_number_to_chars (untruth->word_goes_here, to_addr, 2);
1125 }
1126
1127 /* Install the long jump */
1128 /* this is a long jump from table_ptr+0 to the final target */
1129 from_addr = table_addr;
1130 to_addr = S_GET_VALUE (lie->add) + lie->addnum;
1131 md_create_long_jump (table_ptr, from_addr, to_addr, lie->dispfrag, lie->add);
1132 table_ptr += md_long_jump_size;
1133 table_addr += md_long_jump_size;
1134 }
1135 }
1136 }
1137 #endif /* not WORKING_DOT_WORD */
1138
1139 #ifndef BFD_ASSEMBLER
1140 #ifndef OBJ_VMS
1141 { /* not vms */
1142 /*
1143 * Scan every FixS performing fixups. We had to wait until now to do
1144 * this because md_convert_frag() may have made some fixSs.
1145 */
1146 int trsize, drsize;
1147
1148 subseg_change (SEG_TEXT, 0);
1149 trsize = md_reloc_size * fixup_segment (text_fix_root, SEG_TEXT);
1150 subseg_change (SEG_DATA, 0);
1151 drsize = md_reloc_size * fixup_segment (data_fix_root, SEG_DATA);
1152 H_SET_RELOCATION_SIZE (&headers, trsize, drsize);
1153
1154 /* FIXME move this stuff into the pre-write-hook */
1155 H_SET_MAGIC_NUMBER (&headers, magic_number_for_object_file);
1156 H_SET_ENTRY_POINT (&headers, 0);
1157
1158 obj_pre_write_hook (&headers); /* extra coff stuff */
1159
1160 object_file_size = H_GET_FILE_SIZE (&headers);
1161 next_object_file_charP = the_object_file = xmalloc (object_file_size);
1162
1163 output_file_create (out_file_name);
1164
1165 obj_header_append (&next_object_file_charP, &headers);
1166
1167 know ((next_object_file_charP - the_object_file) == H_GET_HEADER_SIZE (&headers));
1168
1169 /*
1170 * Emit code.
1171 */
1172 for (fragP = text_frag_root; fragP; fragP = fragP->fr_next)
1173 {
1174 register long count;
1175 register char *fill_literal;
1176 register long fill_size;
1177
1178 know (fragP->fr_type == rs_fill);
1179 append (&next_object_file_charP, fragP->fr_literal, (unsigned long) fragP->fr_fix);
1180 fill_literal = fragP->fr_literal + fragP->fr_fix;
1181 fill_size = fragP->fr_var;
1182 know (fragP->fr_offset >= 0);
1183
1184 for (count = fragP->fr_offset; count; count--)
1185 {
1186 append (&next_object_file_charP, fill_literal, (unsigned long) fill_size);
1187 } /* for each */
1188
1189 } /* for each code frag. */
1190
1191 know ((next_object_file_charP - the_object_file) == (H_GET_HEADER_SIZE (&headers) + H_GET_TEXT_SIZE (&headers) + H_GET_DATA_SIZE (&headers)));
1192
1193 /*
1194 * Emit relocations.
1195 */
1196 obj_emit_relocations (&next_object_file_charP, text_fix_root, (relax_addressT) 0);
1197 know ((next_object_file_charP - the_object_file) == (H_GET_HEADER_SIZE (&headers) + H_GET_TEXT_SIZE (&headers) + H_GET_DATA_SIZE (&headers) + H_GET_TEXT_RELOCATION_SIZE (&headers)));
1198 #ifdef TC_I960
1199 /* Make addresses in data relocation directives relative to beginning of
1200 * first data fragment, not end of last text fragment: alignment of the
1201 * start of the data segment may place a gap between the segments.
1202 */
1203 obj_emit_relocations (&next_object_file_charP, data_fix_root, data0_frchainP->frch_root->fr_address);
1204 #else /* TC_I960 */
1205 obj_emit_relocations (&next_object_file_charP, data_fix_root, text_last_frag->fr_address);
1206 #endif /* TC_I960 */
1207
1208 know ((next_object_file_charP - the_object_file) == (H_GET_HEADER_SIZE (&headers) + H_GET_TEXT_SIZE (&headers) + H_GET_DATA_SIZE (&headers) + H_GET_TEXT_RELOCATION_SIZE (&headers) + H_GET_DATA_RELOCATION_SIZE (&headers)));
1209
1210 /*
1211 * Emit line number entries.
1212 */
1213 OBJ_EMIT_LINENO (&next_object_file_charP, lineno_rootP, the_object_file);
1214 know ((next_object_file_charP - the_object_file) == (H_GET_HEADER_SIZE (&headers) + H_GET_TEXT_SIZE (&headers) + H_GET_DATA_SIZE (&headers) + H_GET_TEXT_RELOCATION_SIZE (&headers) + H_GET_DATA_RELOCATION_SIZE (&headers) + H_GET_LINENO_SIZE (&headers)));
1215
1216 /*
1217 * Emit symbols.
1218 */
1219 obj_emit_symbols (&next_object_file_charP, symbol_rootP);
1220 know ((next_object_file_charP - the_object_file) == (H_GET_HEADER_SIZE (&headers) + H_GET_TEXT_SIZE (&headers) + H_GET_DATA_SIZE (&headers) + H_GET_TEXT_RELOCATION_SIZE (&headers) + H_GET_DATA_RELOCATION_SIZE (&headers) + H_GET_LINENO_SIZE (&headers) + H_GET_SYMBOL_TABLE_SIZE (&headers)));
1221
1222 /*
1223 * Emit strings.
1224 */
1225
1226 if (string_byte_count > 0)
1227 {
1228 obj_emit_strings (&next_object_file_charP);
1229 } /* only if we have a string table */
1230
1231 #ifdef BFD_HEADERS
1232 bfd_seek (stdoutput, 0, 0);
1233 bfd_write (the_object_file, 1, object_file_size, stdoutput);
1234 #else
1235
1236 /* Write the data to the file */
1237 output_file_append (the_object_file, object_file_size, out_file_name);
1238 #endif
1239
1240 output_file_close (out_file_name);
1241 } /* non vms output */
1242 #else /* VMS */
1243 /*
1244 * Now do the VMS-dependent part of writing the object file
1245 */
1246 VMS_write_object_file (H_GET_TEXT_SIZE (&headers),
1247 H_GET_DATA_SIZE (&headers),
1248 H_GET_BSS_SIZE (&headers),
1249 text_frag_root, data_frag_root);
1250 #endif /* VMS */
1251 #else /* BFD_ASSEMBLER */
1252
1253 #ifdef obj_check_file_symbols
1254 obj_check_file_symbols ();
1255 #endif
1256
1257 bfd_map_over_sections (stdoutput, adjust_reloc_syms, (char *)0);
1258
1259 /* Set up symbol table, and write it out. */
1260 if (symbol_rootP)
1261 {
1262 int i = 0, n;
1263 symbolS *symp;
1264
1265 for (symp = symbol_rootP; symp; symp = symbol_next (symp))
1266 {
1267 if (! symp->sy_resolved)
1268 {
1269 if (symp->sy_value.X_op == O_constant)
1270 {
1271 /* This is the normal case; skip the call. */
1272 S_SET_VALUE (symp,
1273 (S_GET_VALUE (symp)
1274 + symp->sy_frag->fr_address));
1275 symp->sy_resolved = 1;
1276 }
1277 else
1278 resolve_symbol_value (symp);
1279 }
1280
1281 /* So far, common symbols have been treated like undefined symbols.
1282 Put them in the common section now. */
1283 if (S_IS_DEFINED (symp) == 0
1284 && S_GET_VALUE (symp) != 0)
1285 S_SET_SEGMENT (symp, &bfd_com_section);
1286 #if 0
1287 printf ("symbol `%s'\n\t@%x: value=%d flags=%x seg=%s\n",
1288 S_GET_NAME (symp), symp,
1289 S_GET_VALUE (symp),
1290 symp->bsym->flags,
1291 segment_name (symp->bsym->section));
1292 #endif
1293 {
1294 #ifdef obj_frob_symbol
1295 {
1296 int punt = 0;
1297 obj_frob_symbol (symp, punt);
1298 if (punt)
1299 goto punt_it;
1300 }
1301 #endif
1302 #ifdef tc_frob_symbol
1303 {
1304 int punt = 0;
1305 tc_frob_symbol (symp, punt);
1306 if (punt)
1307 goto punt_it;
1308 }
1309 #endif
1310 }
1311 /* If we don't want to keep this symbol, splice it out of the
1312 chain now. */
1313 if (S_IS_LOCAL (symp))
1314 {
1315 symbolS *prev, *next;
1316 #if defined (obj_frob_symbol) || defined (tc_frob_symbol)
1317 punt_it:
1318 #endif
1319 prev = symbol_previous (symp);
1320 next = symbol_next (symp);
1321 #ifdef DEBUG_SYMS
1322 verify_symbol_chain_2 (symp);
1323 #endif
1324 if (prev)
1325 {
1326 symbol_next (prev) = next;
1327 symp = prev;
1328 }
1329 else if (symp == symbol_rootP)
1330 symbol_rootP = next;
1331 else
1332 abort ();
1333 if (next)
1334 symbol_previous (next) = prev;
1335 else
1336 symbol_lastP = prev;
1337 #ifdef DEBUG_SYMS
1338 if (prev)
1339 verify_symbol_chain_2 (prev);
1340 else if (next)
1341 verify_symbol_chain_2 (next);
1342 #endif
1343 continue;
1344 }
1345
1346 /* Set the value into the BFD symbol. Up til now the value
1347 has only been kept in the gas symbolS struct. */
1348 symp->bsym->value = S_GET_VALUE (symp);
1349
1350 i++;
1351 }
1352 n = i;
1353 if (n)
1354 {
1355 asymbol **asympp;
1356 boolean result;
1357 extern PTR bfd_alloc PARAMS ((bfd *, size_t));
1358
1359 asympp = (asymbol **) bfd_alloc (stdoutput,
1360 n * sizeof (asymbol *));
1361 symp = symbol_rootP;
1362 for (i = 0; i < n; i++, symp = symbol_next (symp))
1363 {
1364 asympp[i] = symp->bsym;
1365 symp->written = 1;
1366 }
1367 result = bfd_set_symtab (stdoutput, asympp, n);
1368 assert (result == true);
1369 }
1370 }
1371
1372
1373 #ifdef obj_frob_file
1374 /* If obj_frob_file changes the symbol value at this point, it is
1375 responsible for moving the changed value into symp->bsym->value
1376 as well. Hopefully all symbol value changing can be done in
1377 {obj,tc}_frob_symbol. */
1378 obj_frob_file ();
1379 #endif
1380
1381 /* Now that all the sizes are known, and contents correct, we can
1382 start writing the file. */
1383 bfd_map_over_sections (stdoutput, write_relocs, (char *) 0);
1384
1385 bfd_map_over_sections (stdoutput, write_contents, (char *) 0);
1386
1387 output_file_close (out_file_name);
1388 #endif /* BFD_ASSEMBLER */
1389 }
1390 #endif /* ! BFD */
1391
1392 /*
1393 * relax_segment()
1394 *
1395 * Now we have a segment, not a crowd of sub-segments, we can make fr_address
1396 * values.
1397 *
1398 * Relax the frags.
1399 *
1400 * After this, all frags in this segment have addresses that are correct
1401 * within the segment. Since segments live in different file addresses,
1402 * these frag addresses may not be the same as final object-file addresses.
1403 */
1404
1405 /* Subroutines of relax_segment. */
1406 static int
1407 is_dnrange (f1, f2)
1408 struct frag *f1;
1409 struct frag *f2;
1410 {
1411 for (; f1; f1 = f1->fr_next)
1412 if (f1->fr_next == f2)
1413 return 1;
1414 return 0;
1415 }
1416
1417 /* Relax_align. Advance location counter to next address that has 'alignment'
1418 lowest order bits all 0s, return size of adjustment made. */
1419 static relax_addressT
1420 relax_align (address, alignment)
1421 register relax_addressT address; /* Address now. */
1422 register int alignment; /* Alignment (binary). */
1423 {
1424 relax_addressT mask;
1425 relax_addressT new_address;
1426
1427 mask = ~((~0) << alignment);
1428 new_address = (address + mask) & (~mask);
1429 if (linkrelax)
1430 /* We must provide lots of padding, so the linker can discard it
1431 when needed. The linker will not add extra space, ever. */
1432 new_address += (1 << alignment);
1433 return (new_address - address);
1434 }
1435
1436 void
1437 relax_segment (segment_frag_root, segment)
1438 struct frag *segment_frag_root;
1439 segT segment;
1440 {
1441 register struct frag *fragP;
1442 register relax_addressT address;
1443 #if !defined (MANY_SEGMENTS) && !defined (BFD_ASSEMBLER)
1444 know (segment == SEG_DATA || segment == SEG_TEXT || segment == SEG_BSS);
1445 #endif
1446 /* In case md_estimate_size_before_relax() wants to make fixSs. */
1447 subseg_change (segment, 0);
1448
1449 /* For each frag in segment: count and store (a 1st guess of)
1450 fr_address. */
1451 address = 0;
1452 for (fragP = segment_frag_root; fragP; fragP = fragP->fr_next)
1453 {
1454 fragP->fr_address = address;
1455 address += fragP->fr_fix;
1456
1457 switch (fragP->fr_type)
1458 {
1459 case rs_fill:
1460 address += fragP->fr_offset * fragP->fr_var;
1461 break;
1462
1463 case rs_align:
1464 address += relax_align (address, (int) fragP->fr_offset);
1465 break;
1466
1467 case rs_org:
1468 /* Assume .org is nugatory. It will grow with 1st relax. */
1469 break;
1470
1471 case rs_machine_dependent:
1472 address += md_estimate_size_before_relax (fragP, segment);
1473 break;
1474
1475 #ifndef WORKING_DOT_WORD
1476 /* Broken words don't concern us yet */
1477 case rs_broken_word:
1478 break;
1479 #endif
1480
1481 default:
1482 BAD_CASE (fragP->fr_type);
1483 break;
1484 } /* switch(fr_type) */
1485 } /* for each frag in the segment */
1486
1487 /* Do relax(). */
1488 {
1489 long stretch; /* May be any size, 0 or negative. */
1490 /* Cumulative number of addresses we have */
1491 /* relaxed this pass. */
1492 /* We may have relaxed more than one address. */
1493 long stretched; /* Have we stretched on this pass? */
1494 /* This is 'cuz stretch may be zero, when, in fact some piece of code
1495 grew, and another shrank. If a branch instruction doesn't fit anymore,
1496 we could be scrod. */
1497
1498 do
1499 {
1500 stretch = stretched = 0;
1501 for (fragP = segment_frag_root; fragP; fragP = fragP->fr_next)
1502 {
1503 long growth = 0;
1504 unsigned long was_address;
1505 long offset;
1506 symbolS *symbolP;
1507 long target;
1508 long after;
1509 long aim;
1510
1511 was_address = fragP->fr_address;
1512 address = fragP->fr_address += stretch;
1513 symbolP = fragP->fr_symbol;
1514 offset = fragP->fr_offset;
1515
1516 switch (fragP->fr_type)
1517 {
1518 case rs_fill: /* .fill never relaxes. */
1519 growth = 0;
1520 break;
1521
1522 #ifndef WORKING_DOT_WORD
1523 /* JF: This is RMS's idea. I do *NOT* want to be blamed
1524 for it I do not want to write it. I do not want to have
1525 anything to do with it. This is not the proper way to
1526 implement this misfeature. */
1527 case rs_broken_word:
1528 {
1529 struct broken_word *lie;
1530 struct broken_word *untruth;
1531
1532 /* Yes this is ugly (storing the broken_word pointer
1533 in the symbol slot). Still, this whole chunk of
1534 code is ugly, and I don't feel like doing anything
1535 about it. Think of it as stubbornness in action. */
1536 growth = 0;
1537 for (lie = (struct broken_word *) (fragP->fr_symbol);
1538 lie && lie->dispfrag == fragP;
1539 lie = lie->next_broken_word)
1540 {
1541
1542 if (lie->added)
1543 continue;
1544
1545 offset = (lie->add->sy_frag->fr_address
1546 + S_GET_VALUE (lie->add)
1547 + lie->addnum
1548 - (lie->sub->sy_frag->fr_address
1549 + S_GET_VALUE (lie->sub)));
1550 if (offset <= -32768 || offset >= 32767)
1551 {
1552 if (flagseen['K'])
1553 {
1554 char buf[50];
1555 sprint_value (buf, lie->addnum);
1556 as_warn (".word %s-%s+%s didn't fit",
1557 S_GET_NAME (lie->add),
1558 S_GET_NAME (lie->sub),
1559 buf);
1560 }
1561 lie->added = 1;
1562 if (fragP->fr_subtype == 0)
1563 {
1564 fragP->fr_subtype++;
1565 growth += md_short_jump_size;
1566 }
1567 for (untruth = lie->next_broken_word;
1568 untruth && untruth->dispfrag == lie->dispfrag;
1569 untruth = untruth->next_broken_word)
1570 if ((untruth->add->sy_frag == lie->add->sy_frag)
1571 && S_GET_VALUE (untruth->add) == S_GET_VALUE (lie->add))
1572 {
1573 untruth->added = 2;
1574 untruth->use_jump = lie;
1575 }
1576 growth += md_long_jump_size;
1577 }
1578 }
1579
1580 break;
1581 } /* case rs_broken_word */
1582 #endif
1583 case rs_align:
1584 growth = (relax_align ((relax_addressT) (address
1585 + fragP->fr_fix),
1586 (int) offset)
1587 - relax_align ((relax_addressT) (was_address
1588 + fragP->fr_fix),
1589 (int) offset));
1590 break;
1591
1592 case rs_org:
1593 target = offset;
1594
1595 if (symbolP)
1596 {
1597 #if !defined (MANY_SEGMENTS) && !defined (BFD_ASSEMBLER)
1598 know ((S_GET_SEGMENT (symbolP) == SEG_ABSOLUTE)
1599 || (S_GET_SEGMENT (symbolP) == SEG_DATA)
1600 || (S_GET_SEGMENT (symbolP) == SEG_TEXT)
1601 || S_GET_SEGMENT (symbolP) == SEG_BSS);
1602 know (symbolP->sy_frag);
1603 know (!(S_GET_SEGMENT (symbolP) == SEG_ABSOLUTE)
1604 || (symbolP->sy_frag == &zero_address_frag));
1605 #endif
1606 target += S_GET_VALUE (symbolP)
1607 + symbolP->sy_frag->fr_address;
1608 } /* if we have a symbol */
1609
1610 know (fragP->fr_next);
1611 after = fragP->fr_next->fr_address;
1612 growth = ((target - after) > 0) ? (target - after) : 0;
1613 /* Growth may be negative, but variable part of frag
1614 cannot have fewer than 0 chars. That is, we can't
1615 .org backwards. */
1616
1617 growth -= stretch; /* This is an absolute growth factor */
1618 break;
1619
1620 case rs_machine_dependent:
1621 {
1622 const relax_typeS *this_type;
1623 const relax_typeS *start_type;
1624 relax_substateT next_state;
1625 relax_substateT this_state;
1626
1627 this_state = fragP->fr_subtype;
1628 start_type = this_type = md_relax_table + this_state;
1629 target = offset;
1630
1631 if (symbolP)
1632 {
1633 #if !defined (MANY_SEGMENTS) && !defined (BFD_ASSEMBLER)
1634 know ((S_GET_SEGMENT (symbolP) == SEG_ABSOLUTE)
1635 || (S_GET_SEGMENT (symbolP) == SEG_DATA)
1636 || (S_GET_SEGMENT (symbolP) == SEG_BSS)
1637 || (S_GET_SEGMENT (symbolP) == SEG_TEXT));
1638 #endif
1639 know (symbolP->sy_frag);
1640 know (!(S_GET_SEGMENT (symbolP) == absolute_section)
1641 || symbolP->sy_frag == &zero_address_frag);
1642 target +=
1643 S_GET_VALUE (symbolP)
1644 + symbolP->sy_frag->fr_address;
1645
1646 /* If frag has yet to be reached on this pass,
1647 assume it will move by STRETCH just as we did.
1648 If this is not so, it will be because some frag
1649 between grows, and that will force another pass.
1650
1651 Beware zero-length frags.
1652
1653 There should be a faster way to do this. */
1654
1655 if (symbolP->sy_frag->fr_address >= was_address
1656 && is_dnrange (fragP, symbolP->sy_frag))
1657 {
1658 target += stretch;
1659 }
1660 }
1661
1662 aim = target - address - fragP->fr_fix;
1663 /* The displacement is affected by the instruction size
1664 for the 32k architecture. I think we ought to be able
1665 to add fragP->fr_pcrel_adjust in all cases (it should be
1666 zero if not used), but just in case it breaks something
1667 else we'll put this inside #ifdef NS32K ... #endif */
1668 #ifndef TC_NS32K
1669 if (fragP->fr_pcrel_adjust)
1670 abort ();
1671 #endif
1672 aim += fragP->fr_pcrel_adjust;
1673
1674 if (aim < 0)
1675 {
1676 /* Look backwards. */
1677 for (next_state = this_type->rlx_more; next_state;)
1678 if (aim >= this_type->rlx_backward)
1679 next_state = 0;
1680 else
1681 {
1682 /* Grow to next state. */
1683 this_state = next_state;
1684 this_type = md_relax_table + this_state;
1685 next_state = this_type->rlx_more;
1686 }
1687 }
1688 else
1689 {
1690 #ifdef M68K_AIM_KLUDGE
1691 M68K_AIM_KLUDGE (aim, this_state, this_type);
1692 #endif
1693 /* Look forwards. */
1694 for (next_state = this_type->rlx_more; next_state;)
1695 if (aim <= this_type->rlx_forward)
1696 next_state = 0;
1697 else
1698 {
1699 /* Grow to next state. */
1700 this_state = next_state;
1701 this_type = md_relax_table + this_state;
1702 next_state = this_type->rlx_more;
1703 }
1704 }
1705
1706 growth = this_type->rlx_length - start_type->rlx_length;
1707 if (growth != 0)
1708 fragP->fr_subtype = this_state;
1709 }
1710 break;
1711
1712 default:
1713 BAD_CASE (fragP->fr_type);
1714 break;
1715 }
1716 if (growth)
1717 {
1718 stretch += growth;
1719 stretched++;
1720 }
1721 } /* For each frag in the segment. */
1722 }
1723 while (stretched); /* Until nothing further to relax. */
1724 } /* do_relax */
1725
1726 /*
1727 * We now have valid fr_address'es for each frag.
1728 */
1729
1730 /*
1731 * All fr_address's are correct, relative to their own segment.
1732 * We have made all the fixS we will ever make.
1733 */
1734 } /* relax_segment() */
1735
1736 /* fixup_segment()
1737
1738 Go through all the fixS's in a segment and see which ones can be
1739 handled now. (These consist of fixS where we have since discovered
1740 the value of a symbol, or the address of the frag involved.)
1741 For each one, call md_apply_fix to put the fix into the frag data.
1742
1743 Result is a count of how many relocation structs will be needed to
1744 handle the remaining fixS's that we couldn't completely handle here.
1745 These will be output later by emit_relocations(). */
1746
1747 static long
1748 fixup_segment (fixP, this_segment_type)
1749 register fixS *fixP;
1750 segT this_segment_type; /* N_TYPE bits for segment. */
1751 {
1752 register long seg_reloc_count;
1753 register symbolS *add_symbolP;
1754 register symbolS *sub_symbolP;
1755 valueT add_number;
1756 register int size;
1757 register char *place;
1758 register long where;
1759 register char pcrel;
1760 register fragS *fragP;
1761 register segT add_symbol_segment = absolute_section;
1762
1763 seg_reloc_count = 0;
1764 /* If the linker is doing the relaxing, we must not do any fixups. */
1765 /* Well, strictly speaking that's not true -- we could do any that
1766 are PC-relative and don't cross regions that could change size.
1767 And for the i960 (the only machine for which we've got a relaxing
1768 linker right now), we might be able to turn callx/callj into bal
1769 in cases where we know the maximum displacement. */
1770 if (linkrelax)
1771 for (; fixP; fixP = fixP->fx_next)
1772 seg_reloc_count++;
1773 else
1774 for (; fixP; fixP = fixP->fx_next)
1775 {
1776 fragP = fixP->fx_frag;
1777 know (fragP);
1778 where = fixP->fx_where;
1779 place = fragP->fr_literal + where;
1780 size = fixP->fx_size;
1781 add_symbolP = fixP->fx_addsy;
1782 #ifdef TC_I960
1783 if (fixP->fx_callj && TC_S_IS_CALLNAME (add_symbolP))
1784 {
1785 /* Relocation should be done via the associated 'bal'
1786 entry point symbol. */
1787
1788 if (!TC_S_IS_BALNAME (tc_get_bal_of_call (add_symbolP)))
1789 {
1790 as_bad ("No 'bal' entry point for leafproc %s",
1791 S_GET_NAME (add_symbolP));
1792 continue;
1793 }
1794 fixP->fx_addsy = add_symbolP = tc_get_bal_of_call (add_symbolP);
1795 }
1796 #endif
1797 sub_symbolP = fixP->fx_subsy;
1798 add_number = fixP->fx_offset;
1799 pcrel = fixP->fx_pcrel;
1800
1801 if (add_symbolP)
1802 add_symbol_segment = S_GET_SEGMENT (add_symbolP);
1803
1804 if (sub_symbolP)
1805 {
1806 if (!add_symbolP)
1807 {
1808 /* Its just -sym */
1809 if (S_GET_SEGMENT (sub_symbolP) != absolute_section)
1810 as_bad ("Negative of non-absolute symbol %s",
1811 S_GET_NAME (sub_symbolP));
1812
1813 add_number -= S_GET_VALUE (sub_symbolP);
1814 }
1815 else if ((S_GET_SEGMENT (sub_symbolP) == add_symbol_segment)
1816 && (SEG_NORMAL (add_symbol_segment)
1817 || (add_symbol_segment == absolute_section)))
1818 {
1819 /* Difference of 2 symbols from same segment.
1820 Can't make difference of 2 undefineds: 'value' means
1821 something different for N_UNDF. */
1822 #ifdef TC_I960
1823 /* Makes no sense to use the difference of 2 arbitrary symbols
1824 as the target of a call instruction. */
1825 if (fixP->fx_callj)
1826 {
1827 as_bad ("callj to difference of 2 symbols");
1828 }
1829 #endif /* TC_I960 */
1830 add_number += S_GET_VALUE (add_symbolP) -
1831 S_GET_VALUE (sub_symbolP);
1832
1833 add_symbolP = NULL;
1834 fixP->fx_addsy = NULL;
1835 }
1836 else
1837 {
1838 /* Different segments in subtraction. */
1839 know (!(S_IS_EXTERNAL (sub_symbolP)
1840 && (S_GET_SEGMENT (sub_symbolP) == absolute_section)));
1841
1842 if ((S_GET_SEGMENT (sub_symbolP) == absolute_section))
1843 {
1844 add_number -= S_GET_VALUE (sub_symbolP);
1845 }
1846 else
1847 {
1848 char buf[50];
1849 sprint_value (buf, fragP->fr_address + where);
1850 as_bad ("Can't emit reloc {- %s-seg symbol \"%s\"} @ file address %s.",
1851 segment_name (S_GET_SEGMENT (sub_symbolP)),
1852 S_GET_NAME (sub_symbolP), buf);
1853 }
1854 }
1855 }
1856
1857 if (add_symbolP)
1858 {
1859 if (add_symbol_segment == this_segment_type && pcrel)
1860 {
1861 /*
1862 * This fixup was made when the symbol's segment was
1863 * SEG_UNKNOWN, but it is now in the local segment.
1864 * So we know how to do the address without relocation.
1865 */
1866 #ifdef TC_I960
1867 /* reloc_callj() may replace a 'call' with a 'calls' or a
1868 'bal', in which cases it modifies *fixP as appropriate.
1869 In the case of a 'calls', no further work is required,
1870 and *fixP has been set up to make the rest of the code
1871 below a no-op. */
1872 reloc_callj (fixP);
1873 #endif /* TC_I960 */
1874
1875 add_number += S_GET_VALUE (add_symbolP);
1876 add_number -= md_pcrel_from (fixP);
1877 pcrel = 0; /* Lie. Don't want further pcrel processing. */
1878 fixP->fx_addsy = NULL; /* No relocations please. */
1879 }
1880 else
1881 {
1882 if (add_symbol_segment == absolute_section)
1883 {
1884 #ifdef TC_I960
1885 /* See comment about reloc_callj() above. */
1886 reloc_callj (fixP);
1887 #endif /* TC_I960 */
1888 add_number += S_GET_VALUE (add_symbolP);
1889 fixP->fx_addsy = NULL;
1890 add_symbolP = NULL;
1891 }
1892 else if (add_symbol_segment == undefined_section
1893 #ifdef BFD_ASSEMBLER
1894 || bfd_is_com_section (add_symbol_segment)
1895 #endif
1896 )
1897 {
1898 #ifdef TC_I960
1899 if ((int) fixP->fx_bit_fixP == 13)
1900 {
1901 /* This is a COBR instruction. They have only a
1902 * 13-bit displacement and are only to be used
1903 * for local branches: flag as error, don't generate
1904 * relocation.
1905 */
1906 as_bad ("can't use COBR format with external label");
1907 fixP->fx_addsy = NULL; /* No relocations please. */
1908 continue;
1909 } /* COBR */
1910 #endif /* TC_I960 */
1911
1912 #ifdef OBJ_COFF
1913 #ifdef TE_I386AIX
1914 if (S_IS_COMMON (add_symbolP))
1915 add_number += S_GET_VALUE (add_symbolP);
1916 #endif /* TE_I386AIX */
1917 #endif /* OBJ_COFF */
1918 ++seg_reloc_count;
1919 }
1920 else
1921 {
1922 seg_reloc_count++;
1923 add_number += S_GET_VALUE (add_symbolP);
1924 }
1925 } /* if not in local seg */
1926 } /* if there was a + symbol */
1927
1928 if (pcrel)
1929 {
1930 add_number -= md_pcrel_from (fixP);
1931 if (add_symbolP == 0)
1932 {
1933 fixP->fx_addsy = &abs_symbol;
1934 ++seg_reloc_count;
1935 } /* if there's an add_symbol */
1936 } /* if pcrel */
1937
1938 if (!fixP->fx_bit_fixP)
1939 {
1940 valueT mask = 0;
1941 /* set all bits to one */
1942 mask--;
1943 /* Technically speaking, combining these produces an
1944 undefined result if size is sizeof (valueT), though I
1945 think these two half-way operations should both be
1946 defined. */
1947 mask <<= size * 4;
1948 mask <<= size * 4;
1949 if ((add_number & mask) != 0
1950 && (add_number & mask) != mask)
1951 {
1952 char buf[50];
1953 sprint_value (buf, fragP->fr_address + where);
1954 as_bad ("Value of %ld too large for field of %d bytes at %s",
1955 (long) add_number, size, buf);
1956 } /* generic error checking */
1957 #ifdef WARN_SIGNED_OVERFLOW_WORD
1958 /* Warn if a .word value is too large when treated as a signed
1959 number. We already know it is not too negative. This is to
1960 catch over-large switches generated by gcc on the 68k. */
1961 if (!flagseen['J']
1962 && size == 2
1963 && add_number > 0x7fff)
1964 as_bad ("Signed .word overflow; switch may be too large; %d at 0x%x",
1965 add_number, fragP->fr_address + where);
1966 #endif
1967 } /* not a bit fix */
1968
1969 #ifdef BFD_ASSEMBLER
1970 md_apply_fix (fixP, &add_number);
1971 #else
1972 md_apply_fix (fixP, add_number);
1973 #endif
1974 } /* For each fixS in this segment. */
1975
1976 #if defined (OBJ_COFF) && defined (TC_I960)
1977 {
1978 fixS *topP = fixP;
1979
1980 /* two relocs per callj under coff. */
1981 for (fixP = topP; fixP; fixP = fixP->fx_next)
1982 if (fixP->fx_callj && fixP->fx_addsy != 0)
1983 ++seg_reloc_count;
1984 }
1985 #endif /* OBJ_COFF && TC_I960 */
1986
1987 return (seg_reloc_count);
1988 }
1989
1990 /* end of write.c */
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