gas/
[binutils.git] / gas / write.c
bloba5d2b4d58da48ae321b17876a2adb32cd918d1af
1 /* write.c - emit .o file
2 Copyright 1986, 1987, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997,
3 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009,
4 2010 Free Software Foundation, Inc.
6 This file is part of GAS, the GNU Assembler.
8 GAS is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3, or (at your option)
11 any later version.
13 GAS is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with GAS; see the file COPYING. If not, write to the Free
20 Software Foundation, 51 Franklin Street - Fifth Floor, Boston, MA
21 02110-1301, USA. */
23 /* This thing should be set up to do byteordering correctly. But... */
25 #include "as.h"
26 #include "subsegs.h"
27 #include "obstack.h"
28 #include "output-file.h"
29 #include "dwarf2dbg.h"
30 #include "libbfd.h"
31 #include "compress-debug.h"
33 #ifndef TC_ADJUST_RELOC_COUNT
34 #define TC_ADJUST_RELOC_COUNT(FIX, COUNT)
35 #endif
37 #ifndef TC_FORCE_RELOCATION
38 #define TC_FORCE_RELOCATION(FIX) \
39 (generic_force_reloc (FIX))
40 #endif
42 #ifndef TC_FORCE_RELOCATION_ABS
43 #define TC_FORCE_RELOCATION_ABS(FIX) \
44 (TC_FORCE_RELOCATION (FIX))
45 #endif
47 #ifndef TC_FORCE_RELOCATION_LOCAL
48 #define TC_FORCE_RELOCATION_LOCAL(FIX) \
49 (!(FIX)->fx_pcrel \
50 || TC_FORCE_RELOCATION (FIX))
51 #endif
53 #ifndef TC_FORCE_RELOCATION_SUB_SAME
54 #define TC_FORCE_RELOCATION_SUB_SAME(FIX, SEG) \
55 (! SEG_NORMAL (SEG))
56 #endif
58 #ifndef md_register_arithmetic
59 # define md_register_arithmetic 1
60 #endif
62 #ifndef TC_FORCE_RELOCATION_SUB_ABS
63 #define TC_FORCE_RELOCATION_SUB_ABS(FIX, SEG) \
64 (!md_register_arithmetic && (SEG) == reg_section)
65 #endif
67 #ifndef TC_FORCE_RELOCATION_SUB_LOCAL
68 #ifdef DIFF_EXPR_OK
69 #define TC_FORCE_RELOCATION_SUB_LOCAL(FIX, SEG) \
70 (!md_register_arithmetic && (SEG) == reg_section)
71 #else
72 #define TC_FORCE_RELOCATION_SUB_LOCAL(FIX, SEG) 1
73 #endif
74 #endif
76 #ifndef TC_VALIDATE_FIX_SUB
77 #ifdef UNDEFINED_DIFFERENCE_OK
78 /* The PA needs this for PIC code generation. */
79 #define TC_VALIDATE_FIX_SUB(FIX, SEG) \
80 (md_register_arithmetic || (SEG) != reg_section)
81 #else
82 #define TC_VALIDATE_FIX_SUB(FIX, SEG) \
83 ((md_register_arithmetic || (SEG) != reg_section) \
84 && ((FIX)->fx_r_type == BFD_RELOC_GPREL32 \
85 || (FIX)->fx_r_type == BFD_RELOC_GPREL16))
86 #endif
87 #endif
89 #ifndef TC_LINKRELAX_FIXUP
90 #define TC_LINKRELAX_FIXUP(SEG) 1
91 #endif
93 #ifndef MD_APPLY_SYM_VALUE
94 #define MD_APPLY_SYM_VALUE(FIX) 1
95 #endif
97 #ifndef TC_FINALIZE_SYMS_BEFORE_SIZE_SEG
98 #define TC_FINALIZE_SYMS_BEFORE_SIZE_SEG 1
99 #endif
101 #ifndef MD_PCREL_FROM_SECTION
102 #define MD_PCREL_FROM_SECTION(FIX, SEC) md_pcrel_from (FIX)
103 #endif
105 #ifndef TC_FAKE_LABEL
106 #define TC_FAKE_LABEL(NAME) (strcmp ((NAME), FAKE_LABEL_NAME) == 0)
107 #endif
109 /* Positive values of TC_FX_SIZE_SLACK allow a target to define
110 fixups that far past the end of a frag. Having such fixups
111 is of course most most likely a bug in setting fx_size correctly.
112 A negative value disables the fixup check entirely, which is
113 appropriate for something like the Renesas / SuperH SH_COUNT
114 reloc. */
115 #ifndef TC_FX_SIZE_SLACK
116 #define TC_FX_SIZE_SLACK(FIX) 0
117 #endif
119 /* Used to control final evaluation of expressions. */
120 int finalize_syms = 0;
122 int symbol_table_frozen;
124 symbolS *abs_section_sym;
126 /* Remember the value of dot when parsing expressions. */
127 addressT dot_value;
129 /* Relocs generated by ".reloc" pseudo. */
130 struct reloc_list* reloc_list;
132 void print_fixup (fixS *);
134 /* We generally attach relocs to frag chains. However, after we have
135 chained these all together into a segment, any relocs we add after
136 that must be attached to a segment. This will include relocs added
137 in md_estimate_size_for_relax, for example. */
138 static int frags_chained = 0;
140 static int n_fixups;
142 #define RELOC_ENUM enum bfd_reloc_code_real
144 /* Create a fixS in obstack 'notes'. */
146 static fixS *
147 fix_new_internal (fragS *frag, /* Which frag? */
148 int where, /* Where in that frag? */
149 int size, /* 1, 2, or 4 usually. */
150 symbolS *add_symbol, /* X_add_symbol. */
151 symbolS *sub_symbol, /* X_op_symbol. */
152 offsetT offset, /* X_add_number. */
153 int pcrel, /* TRUE if PC-relative relocation. */
154 RELOC_ENUM r_type ATTRIBUTE_UNUSED /* Relocation type. */,
155 int at_beginning) /* Add to the start of the list? */
157 fixS *fixP;
159 n_fixups++;
161 fixP = (fixS *) obstack_alloc (&notes, sizeof (fixS));
163 fixP->fx_frag = frag;
164 fixP->fx_where = where;
165 fixP->fx_size = size;
166 /* We've made fx_size a narrow field; check that it's wide enough. */
167 if (fixP->fx_size != size)
169 as_bad (_("field fx_size too small to hold %d"), size);
170 abort ();
172 fixP->fx_addsy = add_symbol;
173 fixP->fx_subsy = sub_symbol;
174 fixP->fx_offset = offset;
175 fixP->fx_dot_value = dot_value;
176 fixP->fx_pcrel = pcrel;
177 fixP->fx_r_type = r_type;
178 fixP->fx_im_disp = 0;
179 fixP->fx_pcrel_adjust = 0;
180 fixP->fx_bit_fixP = 0;
181 fixP->fx_addnumber = 0;
182 fixP->fx_tcbit = 0;
183 fixP->fx_tcbit2 = 0;
184 fixP->fx_done = 0;
185 fixP->fx_no_overflow = 0;
186 fixP->fx_signed = 0;
188 #ifdef USING_CGEN
189 fixP->fx_cgen.insn = NULL;
190 fixP->fx_cgen.opinfo = 0;
191 #endif
193 #ifdef TC_FIX_TYPE
194 TC_INIT_FIX_DATA (fixP);
195 #endif
197 as_where (&fixP->fx_file, &fixP->fx_line);
201 fixS **seg_fix_rootP = (frags_chained
202 ? &seg_info (now_seg)->fix_root
203 : &frchain_now->fix_root);
204 fixS **seg_fix_tailP = (frags_chained
205 ? &seg_info (now_seg)->fix_tail
206 : &frchain_now->fix_tail);
208 if (at_beginning)
210 fixP->fx_next = *seg_fix_rootP;
211 *seg_fix_rootP = fixP;
212 if (fixP->fx_next == NULL)
213 *seg_fix_tailP = fixP;
215 else
217 fixP->fx_next = NULL;
218 if (*seg_fix_tailP)
219 (*seg_fix_tailP)->fx_next = fixP;
220 else
221 *seg_fix_rootP = fixP;
222 *seg_fix_tailP = fixP;
226 return fixP;
229 /* Create a fixup relative to a symbol (plus a constant). */
231 fixS *
232 fix_new (fragS *frag, /* Which frag? */
233 int where, /* Where in that frag? */
234 int size, /* 1, 2, or 4 usually. */
235 symbolS *add_symbol, /* X_add_symbol. */
236 offsetT offset, /* X_add_number. */
237 int pcrel, /* TRUE if PC-relative relocation. */
238 RELOC_ENUM r_type /* Relocation type. */)
240 return fix_new_internal (frag, where, size, add_symbol,
241 (symbolS *) NULL, offset, pcrel, r_type, FALSE);
244 /* Create a fixup for an expression. Currently we only support fixups
245 for difference expressions. That is itself more than most object
246 file formats support anyhow. */
248 fixS *
249 fix_new_exp (fragS *frag, /* Which frag? */
250 int where, /* Where in that frag? */
251 int size, /* 1, 2, or 4 usually. */
252 expressionS *exp, /* Expression. */
253 int pcrel, /* TRUE if PC-relative relocation. */
254 RELOC_ENUM r_type /* Relocation type. */)
256 symbolS *add = NULL;
257 symbolS *sub = NULL;
258 offsetT off = 0;
260 switch (exp->X_op)
262 case O_absent:
263 break;
265 case O_register:
266 as_bad (_("register value used as expression"));
267 break;
269 case O_add:
270 /* This comes up when _GLOBAL_OFFSET_TABLE_+(.-L0) is read, if
271 the difference expression cannot immediately be reduced. */
273 symbolS *stmp = make_expr_symbol (exp);
275 exp->X_op = O_symbol;
276 exp->X_op_symbol = 0;
277 exp->X_add_symbol = stmp;
278 exp->X_add_number = 0;
280 return fix_new_exp (frag, where, size, exp, pcrel, r_type);
283 case O_symbol_rva:
284 add = exp->X_add_symbol;
285 off = exp->X_add_number;
286 r_type = BFD_RELOC_RVA;
287 break;
289 case O_uminus:
290 sub = exp->X_add_symbol;
291 off = exp->X_add_number;
292 break;
294 case O_subtract:
295 sub = exp->X_op_symbol;
296 /* Fall through. */
297 case O_symbol:
298 add = exp->X_add_symbol;
299 /* Fall through. */
300 case O_constant:
301 off = exp->X_add_number;
302 break;
304 default:
305 add = make_expr_symbol (exp);
306 break;
309 return fix_new_internal (frag, where, size, add, sub, off, pcrel,
310 r_type, FALSE);
313 /* Create a fixup at the beginning of FRAG. The arguments are the same
314 as for fix_new, except that WHERE is implicitly 0. */
316 fixS *
317 fix_at_start (fragS *frag, int size, symbolS *add_symbol,
318 offsetT offset, int pcrel, RELOC_ENUM r_type)
320 return fix_new_internal (frag, 0, size, add_symbol,
321 (symbolS *) NULL, offset, pcrel, r_type, TRUE);
324 /* Generic function to determine whether a fixup requires a relocation. */
326 generic_force_reloc (fixS *fix)
328 if (fix->fx_r_type == BFD_RELOC_VTABLE_INHERIT
329 || fix->fx_r_type == BFD_RELOC_VTABLE_ENTRY)
330 return 1;
332 if (fix->fx_addsy == NULL)
333 return 0;
335 return S_FORCE_RELOC (fix->fx_addsy, fix->fx_subsy == NULL);
338 /* Append a string onto another string, bumping the pointer along. */
339 void
340 append (char **charPP, char *fromP, unsigned long length)
342 /* Don't trust memcpy() of 0 chars. */
343 if (length == 0)
344 return;
346 memcpy (*charPP, fromP, length);
347 *charPP += length;
350 /* This routine records the largest alignment seen for each segment.
351 If the beginning of the segment is aligned on the worst-case
352 boundary, all of the other alignments within it will work. At
353 least one object format really uses this info. */
355 void
356 record_alignment (/* Segment to which alignment pertains. */
357 segT seg,
358 /* Alignment, as a power of 2 (e.g., 1 => 2-byte
359 boundary, 2 => 4-byte boundary, etc.) */
360 int align)
362 if (seg == absolute_section)
363 return;
365 if ((unsigned int) align > bfd_get_section_alignment (stdoutput, seg))
366 bfd_set_section_alignment (stdoutput, seg, align);
370 get_recorded_alignment (segT seg)
372 if (seg == absolute_section)
373 return 0;
375 return bfd_get_section_alignment (stdoutput, seg);
378 /* Reset the section indices after removing the gas created sections. */
380 static void
381 renumber_sections (bfd *abfd ATTRIBUTE_UNUSED, asection *sec, void *countparg)
383 int *countp = (int *) countparg;
385 sec->index = *countp;
386 ++*countp;
389 static fragS *
390 chain_frchains_together_1 (segT section, struct frchain *frchp)
392 fragS dummy, *prev_frag = &dummy;
393 fixS fix_dummy, *prev_fix = &fix_dummy;
395 for (; frchp; frchp = frchp->frch_next)
397 prev_frag->fr_next = frchp->frch_root;
398 prev_frag = frchp->frch_last;
399 gas_assert (prev_frag->fr_type != 0);
400 if (frchp->fix_root != (fixS *) NULL)
402 if (seg_info (section)->fix_root == (fixS *) NULL)
403 seg_info (section)->fix_root = frchp->fix_root;
404 prev_fix->fx_next = frchp->fix_root;
405 seg_info (section)->fix_tail = frchp->fix_tail;
406 prev_fix = frchp->fix_tail;
409 gas_assert (prev_frag->fr_type != 0);
410 gas_assert (prev_frag != &dummy);
411 prev_frag->fr_next = 0;
412 return prev_frag;
415 static void
416 chain_frchains_together (bfd *abfd ATTRIBUTE_UNUSED,
417 segT section,
418 void *xxx ATTRIBUTE_UNUSED)
420 segment_info_type *info;
422 /* BFD may have introduced its own sections without using
423 subseg_new, so it is possible that seg_info is NULL. */
424 info = seg_info (section);
425 if (info != (segment_info_type *) NULL)
426 info->frchainP->frch_last
427 = chain_frchains_together_1 (section, info->frchainP);
429 /* Now that we've chained the frags together, we must add new fixups
430 to the segment, not to the frag chain. */
431 frags_chained = 1;
434 static void
435 cvt_frag_to_fill (segT sec ATTRIBUTE_UNUSED, fragS *fragP)
437 switch (fragP->fr_type)
439 case rs_align:
440 case rs_align_code:
441 case rs_align_test:
442 case rs_org:
443 case rs_space:
444 #ifdef HANDLE_ALIGN
445 HANDLE_ALIGN (fragP);
446 #endif
447 know (fragP->fr_next != NULL);
448 fragP->fr_offset = (fragP->fr_next->fr_address
449 - fragP->fr_address
450 - fragP->fr_fix) / fragP->fr_var;
451 if (fragP->fr_offset < 0)
453 as_bad_where (fragP->fr_file, fragP->fr_line,
454 _("attempt to .org/.space backwards? (%ld)"),
455 (long) fragP->fr_offset);
456 fragP->fr_offset = 0;
458 fragP->fr_type = rs_fill;
459 break;
461 case rs_fill:
462 break;
464 case rs_leb128:
466 valueT value = S_GET_VALUE (fragP->fr_symbol);
467 int size;
469 size = output_leb128 (fragP->fr_literal + fragP->fr_fix, value,
470 fragP->fr_subtype);
472 fragP->fr_fix += size;
473 fragP->fr_type = rs_fill;
474 fragP->fr_var = 0;
475 fragP->fr_offset = 0;
476 fragP->fr_symbol = NULL;
478 break;
480 case rs_cfa:
481 eh_frame_convert_frag (fragP);
482 break;
484 case rs_dwarf2dbg:
485 dwarf2dbg_convert_frag (fragP);
486 break;
488 case rs_machine_dependent:
489 md_convert_frag (stdoutput, sec, fragP);
491 gas_assert (fragP->fr_next == NULL
492 || ((offsetT) (fragP->fr_next->fr_address - fragP->fr_address)
493 == fragP->fr_fix));
495 /* After md_convert_frag, we make the frag into a ".space 0".
496 md_convert_frag() should set up any fixSs and constants
497 required. */
498 frag_wane (fragP);
499 break;
501 #ifndef WORKING_DOT_WORD
502 case rs_broken_word:
504 struct broken_word *lie;
506 if (fragP->fr_subtype)
508 fragP->fr_fix += md_short_jump_size;
509 for (lie = (struct broken_word *) (fragP->fr_symbol);
510 lie && lie->dispfrag == fragP;
511 lie = lie->next_broken_word)
512 if (lie->added == 1)
513 fragP->fr_fix += md_long_jump_size;
515 frag_wane (fragP);
517 break;
518 #endif
520 default:
521 BAD_CASE (fragP->fr_type);
522 break;
524 #ifdef md_frag_check
525 md_frag_check (fragP);
526 #endif
529 struct relax_seg_info
531 int pass;
532 int changed;
535 static void
536 relax_seg (bfd *abfd ATTRIBUTE_UNUSED, asection *sec, void *xxx)
538 segment_info_type *seginfo = seg_info (sec);
539 struct relax_seg_info *info = (struct relax_seg_info *) xxx;
541 if (seginfo && seginfo->frchainP
542 && relax_segment (seginfo->frchainP->frch_root, sec, info->pass))
543 info->changed = 1;
546 static void
547 size_seg (bfd *abfd, asection *sec, void *xxx ATTRIBUTE_UNUSED)
549 flagword flags;
550 fragS *fragp;
551 segment_info_type *seginfo;
552 int x;
553 valueT size, newsize;
555 subseg_change (sec, 0);
557 seginfo = seg_info (sec);
558 if (seginfo && seginfo->frchainP)
560 for (fragp = seginfo->frchainP->frch_root; fragp; fragp = fragp->fr_next)
561 cvt_frag_to_fill (sec, fragp);
562 for (fragp = seginfo->frchainP->frch_root;
563 fragp->fr_next;
564 fragp = fragp->fr_next)
565 /* Walk to last elt. */
567 size = fragp->fr_address + fragp->fr_fix;
569 else
570 size = 0;
572 flags = bfd_get_section_flags (abfd, sec);
573 if (size == 0 && bfd_get_section_size (sec) != 0 &&
574 (flags & SEC_HAS_CONTENTS) != 0)
575 return;
577 if (size > 0 && ! seginfo->bss)
578 flags |= SEC_HAS_CONTENTS;
580 flags &= ~SEC_RELOC;
581 x = bfd_set_section_flags (abfd, sec, flags);
582 gas_assert (x);
584 newsize = md_section_align (sec, size);
585 x = bfd_set_section_size (abfd, sec, newsize);
586 gas_assert (x);
588 /* If the size had to be rounded up, add some padding in the last
589 non-empty frag. */
590 gas_assert (newsize >= size);
591 if (size != newsize)
593 fragS *last = seginfo->frchainP->frch_last;
594 fragp = seginfo->frchainP->frch_root;
595 while (fragp->fr_next != last)
596 fragp = fragp->fr_next;
597 last->fr_address = size;
598 if ((newsize - size) % fragp->fr_var == 0)
599 fragp->fr_offset += (newsize - size) / fragp->fr_var;
600 else
601 /* If we hit this abort, it's likely due to subsegs_finish not
602 providing sufficient alignment on the last frag, and the
603 machine dependent code using alignment frags with fr_var
604 greater than 1. */
605 abort ();
608 #ifdef tc_frob_section
609 tc_frob_section (sec);
610 #endif
611 #ifdef obj_frob_section
612 obj_frob_section (sec);
613 #endif
616 #ifdef DEBUG2
617 static void
618 dump_section_relocs (bfd *abfd ATTRIBUTE_UNUSED, asection *sec, FILE *stream)
620 segment_info_type *seginfo = seg_info (sec);
621 fixS *fixp = seginfo->fix_root;
623 if (!fixp)
624 return;
626 fprintf (stream, "sec %s relocs:\n", sec->name);
627 while (fixp)
629 symbolS *s = fixp->fx_addsy;
631 fprintf (stream, " %08lx: type %d ", (unsigned long) fixp,
632 (int) fixp->fx_r_type);
633 if (s == NULL)
634 fprintf (stream, "no sym\n");
635 else
637 print_symbol_value_1 (stream, s);
638 fprintf (stream, "\n");
640 fixp = fixp->fx_next;
643 #else
644 #define dump_section_relocs(ABFD,SEC,STREAM) ((void) 0)
645 #endif
647 #ifndef EMIT_SECTION_SYMBOLS
648 #define EMIT_SECTION_SYMBOLS 1
649 #endif
651 /* Resolve U.A.OFFSET_SYM and U.A.SYM fields of RELOC_LIST entries,
652 and check for validity. Convert RELOC_LIST from using U.A fields
653 to U.B fields. */
654 static void
655 resolve_reloc_expr_symbols (void)
657 struct reloc_list *r;
659 for (r = reloc_list; r; r = r->next)
661 expressionS *symval;
662 symbolS *sym;
663 bfd_vma offset, addend;
664 asection *sec;
665 reloc_howto_type *howto;
667 resolve_symbol_value (r->u.a.offset_sym);
668 symval = symbol_get_value_expression (r->u.a.offset_sym);
670 offset = 0;
671 sym = NULL;
672 if (symval->X_op == O_constant)
673 sym = r->u.a.offset_sym;
674 else if (symval->X_op == O_symbol)
676 sym = symval->X_add_symbol;
677 offset = symval->X_add_number;
678 symval = symbol_get_value_expression (symval->X_add_symbol);
680 if (sym == NULL
681 || symval->X_op != O_constant
682 || (sec = S_GET_SEGMENT (sym)) == NULL
683 || !SEG_NORMAL (sec))
685 as_bad_where (r->file, r->line, _("invalid offset expression"));
686 sec = NULL;
688 else
689 offset += S_GET_VALUE (sym);
691 sym = NULL;
692 addend = r->u.a.addend;
693 if (r->u.a.sym != NULL)
695 resolve_symbol_value (r->u.a.sym);
696 symval = symbol_get_value_expression (r->u.a.sym);
697 if (symval->X_op == O_constant)
698 sym = r->u.a.sym;
699 else if (symval->X_op == O_symbol)
701 sym = symval->X_add_symbol;
702 addend += symval->X_add_number;
703 symval = symbol_get_value_expression (symval->X_add_symbol);
705 if (symval->X_op != O_constant)
707 as_bad_where (r->file, r->line, _("invalid reloc expression"));
708 sec = NULL;
710 else if (sym != NULL)
711 symbol_mark_used_in_reloc (sym);
713 if (sym == NULL)
715 if (abs_section_sym == NULL)
716 abs_section_sym = section_symbol (absolute_section);
717 sym = abs_section_sym;
720 howto = r->u.a.howto;
722 r->u.b.sec = sec;
723 r->u.b.s = symbol_get_bfdsym (sym);
724 r->u.b.r.sym_ptr_ptr = &r->u.b.s;
725 r->u.b.r.address = offset;
726 r->u.b.r.addend = addend;
727 r->u.b.r.howto = howto;
731 /* This pass over fixups decides whether symbols can be replaced with
732 section symbols. */
734 static void
735 adjust_reloc_syms (bfd *abfd ATTRIBUTE_UNUSED,
736 asection *sec,
737 void *xxx ATTRIBUTE_UNUSED)
739 segment_info_type *seginfo = seg_info (sec);
740 fixS *fixp;
742 if (seginfo == NULL)
743 return;
745 dump_section_relocs (abfd, sec, stderr);
747 for (fixp = seginfo->fix_root; fixp; fixp = fixp->fx_next)
748 if (fixp->fx_done)
749 /* Ignore it. */
751 else if (fixp->fx_addsy)
753 symbolS *sym;
754 asection *symsec;
756 #ifdef DEBUG5
757 fprintf (stderr, "\n\nadjusting fixup:\n");
758 print_fixup (fixp);
759 #endif
761 sym = fixp->fx_addsy;
763 /* All symbols should have already been resolved at this
764 point. It is possible to see unresolved expression
765 symbols, though, since they are not in the regular symbol
766 table. */
767 resolve_symbol_value (sym);
769 if (fixp->fx_subsy != NULL)
770 resolve_symbol_value (fixp->fx_subsy);
772 /* If this symbol is equated to an undefined or common symbol,
773 convert the fixup to being against that symbol. */
774 while (symbol_equated_reloc_p (sym)
775 || S_IS_WEAKREFR (sym))
777 symbolS *newsym = symbol_get_value_expression (sym)->X_add_symbol;
778 if (sym == newsym)
779 break;
780 fixp->fx_offset += symbol_get_value_expression (sym)->X_add_number;
781 fixp->fx_addsy = newsym;
782 sym = newsym;
785 if (symbol_mri_common_p (sym))
787 fixp->fx_offset += S_GET_VALUE (sym);
788 fixp->fx_addsy = symbol_get_value_expression (sym)->X_add_symbol;
789 continue;
792 /* If the symbol is undefined, common, weak, or global (ELF
793 shared libs), we can't replace it with the section symbol. */
794 if (S_FORCE_RELOC (fixp->fx_addsy, 1))
795 continue;
797 /* Is there some other (target cpu dependent) reason we can't adjust
798 this one? (E.g. relocations involving function addresses on
799 the PA. */
800 #ifdef tc_fix_adjustable
801 if (! tc_fix_adjustable (fixp))
802 continue;
803 #endif
805 /* Since we're reducing to section symbols, don't attempt to reduce
806 anything that's already using one. */
807 if (symbol_section_p (sym))
808 continue;
810 symsec = S_GET_SEGMENT (sym);
811 if (symsec == NULL)
812 abort ();
814 if (bfd_is_abs_section (symsec))
816 /* The fixup_segment routine normally will not use this
817 symbol in a relocation. */
818 continue;
821 /* Don't try to reduce relocs which refer to non-local symbols
822 in .linkonce sections. It can lead to confusion when a
823 debugging section refers to a .linkonce section. I hope
824 this will always be correct. */
825 if (symsec != sec && ! S_IS_LOCAL (sym))
827 if ((symsec->flags & SEC_LINK_ONCE) != 0
828 || (IS_ELF
829 /* The GNU toolchain uses an extension for ELF: a
830 section beginning with the magic string
831 .gnu.linkonce is a linkonce section. */
832 && strncmp (segment_name (symsec), ".gnu.linkonce",
833 sizeof ".gnu.linkonce" - 1) == 0))
834 continue;
837 /* Never adjust a reloc against local symbol in a merge section
838 with non-zero addend. */
839 if ((symsec->flags & SEC_MERGE) != 0
840 && (fixp->fx_offset != 0 || fixp->fx_subsy != NULL))
841 continue;
843 /* Never adjust a reloc against TLS local symbol. */
844 if ((symsec->flags & SEC_THREAD_LOCAL) != 0)
845 continue;
847 /* We refetch the segment when calling section_symbol, rather
848 than using symsec, because S_GET_VALUE may wind up changing
849 the section when it calls resolve_symbol_value. */
850 fixp->fx_offset += S_GET_VALUE (sym);
851 fixp->fx_addsy = section_symbol (S_GET_SEGMENT (sym));
852 #ifdef DEBUG5
853 fprintf (stderr, "\nadjusted fixup:\n");
854 print_fixup (fixp);
855 #endif
858 dump_section_relocs (abfd, sec, stderr);
861 /* fixup_segment()
863 Go through all the fixS's in a segment and see which ones can be
864 handled now. (These consist of fixS where we have since discovered
865 the value of a symbol, or the address of the frag involved.)
866 For each one, call md_apply_fix to put the fix into the frag data.
868 Result is a count of how many relocation structs will be needed to
869 handle the remaining fixS's that we couldn't completely handle here.
870 These will be output later by emit_relocations(). */
872 static long
873 fixup_segment (fixS *fixP, segT this_segment)
875 long seg_reloc_count = 0;
876 valueT add_number;
877 fragS *fragP;
878 segT add_symbol_segment = absolute_section;
880 if (fixP != NULL && abs_section_sym == NULL)
881 abs_section_sym = section_symbol (absolute_section);
883 /* If the linker is doing the relaxing, we must not do any fixups.
885 Well, strictly speaking that's not true -- we could do any that
886 are PC-relative and don't cross regions that could change size.
887 And for the i960 we might be able to turn callx/callj into bal
888 anyways in cases where we know the maximum displacement. */
889 if (linkrelax && TC_LINKRELAX_FIXUP (this_segment))
891 for (; fixP; fixP = fixP->fx_next)
892 if (!fixP->fx_done)
894 if (fixP->fx_addsy == NULL)
896 /* There was no symbol required by this relocation.
897 However, BFD doesn't really handle relocations
898 without symbols well. So fake up a local symbol in
899 the absolute section. */
900 fixP->fx_addsy = abs_section_sym;
902 symbol_mark_used_in_reloc (fixP->fx_addsy);
903 if (fixP->fx_subsy != NULL)
904 symbol_mark_used_in_reloc (fixP->fx_subsy);
905 seg_reloc_count++;
907 TC_ADJUST_RELOC_COUNT (fixP, seg_reloc_count);
908 return seg_reloc_count;
911 for (; fixP; fixP = fixP->fx_next)
913 #ifdef DEBUG5
914 fprintf (stderr, "\nprocessing fixup:\n");
915 print_fixup (fixP);
916 #endif
918 fragP = fixP->fx_frag;
919 know (fragP);
920 #ifdef TC_VALIDATE_FIX
921 TC_VALIDATE_FIX (fixP, this_segment, skip);
922 #endif
923 add_number = fixP->fx_offset;
925 if (fixP->fx_addsy != NULL)
926 add_symbol_segment = S_GET_SEGMENT (fixP->fx_addsy);
928 if (fixP->fx_subsy != NULL)
930 segT sub_symbol_segment;
931 resolve_symbol_value (fixP->fx_subsy);
932 sub_symbol_segment = S_GET_SEGMENT (fixP->fx_subsy);
933 if (fixP->fx_addsy != NULL
934 && sub_symbol_segment == add_symbol_segment
935 && !S_FORCE_RELOC (fixP->fx_addsy, 0)
936 && !S_FORCE_RELOC (fixP->fx_subsy, 0)
937 && !TC_FORCE_RELOCATION_SUB_SAME (fixP, add_symbol_segment))
939 add_number += S_GET_VALUE (fixP->fx_addsy);
940 add_number -= S_GET_VALUE (fixP->fx_subsy);
941 fixP->fx_offset = add_number;
942 fixP->fx_addsy = NULL;
943 fixP->fx_subsy = NULL;
944 #ifdef TC_M68K
945 /* See the comment below about 68k weirdness. */
946 fixP->fx_pcrel = 0;
947 #endif
949 else if (sub_symbol_segment == absolute_section
950 && !S_FORCE_RELOC (fixP->fx_subsy, 0)
951 && !TC_FORCE_RELOCATION_SUB_ABS (fixP, add_symbol_segment))
953 add_number -= S_GET_VALUE (fixP->fx_subsy);
954 fixP->fx_offset = add_number;
955 fixP->fx_subsy = NULL;
957 else if (sub_symbol_segment == this_segment
958 && !S_FORCE_RELOC (fixP->fx_subsy, 0)
959 && !TC_FORCE_RELOCATION_SUB_LOCAL (fixP, add_symbol_segment))
961 add_number -= S_GET_VALUE (fixP->fx_subsy);
962 fixP->fx_offset = (add_number + fixP->fx_dot_value
963 + fixP->fx_frag->fr_address);
965 /* Make it pc-relative. If the back-end code has not
966 selected a pc-relative reloc, cancel the adjustment
967 we do later on all pc-relative relocs. */
968 if (0
969 #ifdef TC_M68K
970 /* Do this for m68k even if it's already described
971 as pc-relative. On the m68k, an operand of
972 "pc@(foo-.-2)" should address "foo" in a
973 pc-relative mode. */
974 || 1
975 #endif
976 || !fixP->fx_pcrel)
977 add_number += MD_PCREL_FROM_SECTION (fixP, this_segment);
978 fixP->fx_subsy = NULL;
979 fixP->fx_pcrel = 1;
981 else if (!TC_VALIDATE_FIX_SUB (fixP, add_symbol_segment))
983 if (!md_register_arithmetic
984 && (add_symbol_segment == reg_section
985 || sub_symbol_segment == reg_section))
986 as_bad_where (fixP->fx_file, fixP->fx_line,
987 _("register value used as expression"));
988 else
989 as_bad_where (fixP->fx_file, fixP->fx_line,
990 _("can't resolve `%s' {%s section} - `%s' {%s section}"),
991 fixP->fx_addsy ? S_GET_NAME (fixP->fx_addsy) : "0",
992 segment_name (add_symbol_segment),
993 S_GET_NAME (fixP->fx_subsy),
994 segment_name (sub_symbol_segment));
998 if (fixP->fx_addsy)
1000 if (add_symbol_segment == this_segment
1001 && !S_FORCE_RELOC (fixP->fx_addsy, 0)
1002 && !TC_FORCE_RELOCATION_LOCAL (fixP))
1004 /* This fixup was made when the symbol's segment was
1005 SEG_UNKNOWN, but it is now in the local segment.
1006 So we know how to do the address without relocation. */
1007 add_number += S_GET_VALUE (fixP->fx_addsy);
1008 fixP->fx_offset = add_number;
1009 if (fixP->fx_pcrel)
1010 add_number -= MD_PCREL_FROM_SECTION (fixP, this_segment);
1011 fixP->fx_addsy = NULL;
1012 fixP->fx_pcrel = 0;
1014 else if (add_symbol_segment == absolute_section
1015 && !S_FORCE_RELOC (fixP->fx_addsy, 0)
1016 && !TC_FORCE_RELOCATION_ABS (fixP))
1018 add_number += S_GET_VALUE (fixP->fx_addsy);
1019 fixP->fx_offset = add_number;
1020 fixP->fx_addsy = NULL;
1022 else if (add_symbol_segment != undefined_section
1023 && ! bfd_is_com_section (add_symbol_segment)
1024 && MD_APPLY_SYM_VALUE (fixP))
1025 add_number += S_GET_VALUE (fixP->fx_addsy);
1028 if (fixP->fx_pcrel)
1030 add_number -= MD_PCREL_FROM_SECTION (fixP, this_segment);
1031 if (!fixP->fx_done && fixP->fx_addsy == NULL)
1033 /* There was no symbol required by this relocation.
1034 However, BFD doesn't really handle relocations
1035 without symbols well. So fake up a local symbol in
1036 the absolute section. */
1037 fixP->fx_addsy = abs_section_sym;
1041 if (!fixP->fx_done)
1042 md_apply_fix (fixP, &add_number, this_segment);
1044 if (!fixP->fx_done)
1046 ++seg_reloc_count;
1047 if (fixP->fx_addsy == NULL)
1048 fixP->fx_addsy = abs_section_sym;
1049 symbol_mark_used_in_reloc (fixP->fx_addsy);
1050 if (fixP->fx_subsy != NULL)
1051 symbol_mark_used_in_reloc (fixP->fx_subsy);
1054 if (!fixP->fx_bit_fixP && !fixP->fx_no_overflow && fixP->fx_size != 0)
1056 if (fixP->fx_size < sizeof (valueT))
1058 valueT mask;
1060 mask = 0;
1061 mask--; /* Set all bits to one. */
1062 mask <<= fixP->fx_size * 8 - (fixP->fx_signed ? 1 : 0);
1063 if ((add_number & mask) != 0 && (add_number & mask) != mask)
1065 char buf[50], buf2[50];
1066 sprint_value (buf, fragP->fr_address + fixP->fx_where);
1067 if (add_number > 1000)
1068 sprint_value (buf2, add_number);
1069 else
1070 sprintf (buf2, "%ld", (long) add_number);
1071 as_bad_where (fixP->fx_file, fixP->fx_line,
1072 _("value of %s too large for field of %d bytes at %s"),
1073 buf2, fixP->fx_size, buf);
1074 } /* Generic error checking. */
1076 #ifdef WARN_SIGNED_OVERFLOW_WORD
1077 /* Warn if a .word value is too large when treated as a signed
1078 number. We already know it is not too negative. This is to
1079 catch over-large switches generated by gcc on the 68k. */
1080 if (!flag_signed_overflow_ok
1081 && fixP->fx_size == 2
1082 && add_number > 0x7fff)
1083 as_bad_where (fixP->fx_file, fixP->fx_line,
1084 _("signed .word overflow; switch may be too large; %ld at 0x%lx"),
1085 (long) add_number,
1086 (long) (fragP->fr_address + fixP->fx_where));
1087 #endif
1088 } /* Not a bit fix. */
1090 #ifdef TC_VALIDATE_FIX
1091 skip: ATTRIBUTE_UNUSED_LABEL
1093 #endif
1094 #ifdef DEBUG5
1095 fprintf (stderr, "result:\n");
1096 print_fixup (fixP);
1097 #endif
1098 } /* For each fixS in this segment. */
1100 TC_ADJUST_RELOC_COUNT (fixP, seg_reloc_count);
1101 return seg_reloc_count;
1104 static void
1105 fix_segment (bfd *abfd ATTRIBUTE_UNUSED,
1106 asection *sec,
1107 void *xxx ATTRIBUTE_UNUSED)
1109 segment_info_type *seginfo = seg_info (sec);
1111 fixup_segment (seginfo->fix_root, sec);
1114 static void
1115 install_reloc (asection *sec, arelent *reloc, fragS *fragp,
1116 char *file, unsigned int line)
1118 char *err;
1119 bfd_reloc_status_type s;
1120 asymbol *sym;
1122 if (reloc->sym_ptr_ptr != NULL
1123 && (sym = *reloc->sym_ptr_ptr) != NULL
1124 && (sym->flags & BSF_KEEP) == 0
1125 && ((sym->flags & BSF_SECTION_SYM) == 0
1126 || (EMIT_SECTION_SYMBOLS
1127 && !bfd_is_abs_section (sym->section))))
1128 as_bad_where (file, line, _("redefined symbol cannot be used on reloc"));
1130 s = bfd_install_relocation (stdoutput, reloc,
1131 fragp->fr_literal, fragp->fr_address,
1132 sec, &err);
1133 switch (s)
1135 case bfd_reloc_ok:
1136 break;
1137 case bfd_reloc_overflow:
1138 as_bad_where (file, line, _("relocation overflow"));
1139 break;
1140 case bfd_reloc_outofrange:
1141 as_bad_where (file, line, _("relocation out of range"));
1142 break;
1143 default:
1144 as_fatal (_("%s:%u: bad return from bfd_install_relocation: %x"),
1145 file, line, s);
1149 static void
1150 write_relocs (bfd *abfd, asection *sec, void *xxx ATTRIBUTE_UNUSED)
1152 segment_info_type *seginfo = seg_info (sec);
1153 unsigned int i;
1154 unsigned int n;
1155 struct reloc_list *my_reloc_list, **rp, *r;
1156 arelent **relocs;
1157 fixS *fixp;
1159 /* If seginfo is NULL, we did not create this section; don't do
1160 anything with it. */
1161 if (seginfo == NULL)
1162 return;
1164 n = 0;
1165 for (fixp = seginfo->fix_root; fixp; fixp = fixp->fx_next)
1166 if (!fixp->fx_done)
1167 n++;
1169 #ifdef RELOC_EXPANSION_POSSIBLE
1170 n *= MAX_RELOC_EXPANSION;
1171 #endif
1173 /* Extract relocs for this section from reloc_list. */
1174 rp = &reloc_list;
1175 my_reloc_list = NULL;
1176 while ((r = *rp) != NULL)
1178 if (r->u.b.sec == sec)
1180 *rp = r->next;
1181 r->next = my_reloc_list;
1182 my_reloc_list = r;
1183 n++;
1185 else
1186 rp = &r->next;
1189 relocs = (arelent **) xcalloc (n, sizeof (arelent *));
1191 i = 0;
1192 for (fixp = seginfo->fix_root; fixp != (fixS *) NULL; fixp = fixp->fx_next)
1194 int j;
1195 int fx_size, slack;
1196 offsetT loc;
1198 if (fixp->fx_done)
1199 continue;
1201 fx_size = fixp->fx_size;
1202 slack = TC_FX_SIZE_SLACK (fixp);
1203 if (slack > 0)
1204 fx_size = fx_size > slack ? fx_size - slack : 0;
1205 loc = fixp->fx_where + fx_size;
1206 if (slack >= 0 && loc > fixp->fx_frag->fr_fix)
1207 as_bad_where (fixp->fx_file, fixp->fx_line,
1208 _("internal error: fixup not contained within frag"));
1210 #ifndef RELOC_EXPANSION_POSSIBLE
1212 arelent *reloc = tc_gen_reloc (sec, fixp);
1214 if (!reloc)
1215 continue;
1216 relocs[i++] = reloc;
1217 j = 1;
1219 #else
1221 arelent **reloc = tc_gen_reloc (sec, fixp);
1223 for (j = 0; reloc[j]; j++)
1224 relocs[i++] = reloc[j];
1226 #endif
1228 for ( ; j != 0; --j)
1229 install_reloc (sec, relocs[i - j], fixp->fx_frag,
1230 fixp->fx_file, fixp->fx_line);
1232 n = i;
1234 #ifdef DEBUG4
1236 unsigned int i, j, nsyms;
1237 asymbol **sympp;
1238 sympp = bfd_get_outsymbols (stdoutput);
1239 nsyms = bfd_get_symcount (stdoutput);
1240 for (i = 0; i < n; i++)
1241 if (((*relocs[i]->sym_ptr_ptr)->flags & BSF_SECTION_SYM) == 0)
1243 for (j = 0; j < nsyms; j++)
1244 if (sympp[j] == *relocs[i]->sym_ptr_ptr)
1245 break;
1246 if (j == nsyms)
1247 abort ();
1250 #endif
1252 for (r = my_reloc_list; r != NULL; r = r->next)
1254 fragS *f;
1255 for (f = seginfo->frchainP->frch_root; f; f = f->fr_next)
1256 if (f->fr_address <= r->u.b.r.address
1257 && r->u.b.r.address < f->fr_address + f->fr_fix)
1258 break;
1259 if (f == NULL)
1260 as_bad_where (r->file, r->line,
1261 _("reloc not within (fixed part of) section"));
1262 else
1264 relocs[n++] = &r->u.b.r;
1265 install_reloc (sec, &r->u.b.r, f, r->file, r->line);
1269 if (n)
1271 flagword flags = bfd_get_section_flags (abfd, sec);
1272 flags |= SEC_RELOC;
1273 bfd_set_section_flags (abfd, sec, flags);
1274 bfd_set_reloc (stdoutput, sec, relocs, n);
1277 #ifdef SET_SECTION_RELOCS
1278 SET_SECTION_RELOCS (sec, relocs, n);
1279 #endif
1281 #ifdef DEBUG3
1283 unsigned int i;
1284 arelent *r;
1285 asymbol *s;
1286 fprintf (stderr, "relocs for sec %s\n", sec->name);
1287 for (i = 0; i < n; i++)
1289 r = relocs[i];
1290 s = *r->sym_ptr_ptr;
1291 fprintf (stderr, " reloc %2d @%p off %4lx : sym %-10s addend %lx\n",
1292 i, r, (unsigned long)r->address, s->name, (unsigned long)r->addend);
1295 #endif
1298 static int
1299 compress_frag (struct z_stream_s *strm, const char *contents, int in_size,
1300 fragS **last_newf, struct obstack *ob)
1302 int out_size;
1303 int total_out_size = 0;
1304 fragS *f = *last_newf;
1305 char *next_out;
1306 int avail_out;
1308 /* Call the compression routine repeatedly until it has finished
1309 processing the frag. */
1310 while (in_size > 0)
1312 /* Reserve all the space available in the current chunk.
1313 If none is available, start a new frag. */
1314 avail_out = obstack_room (ob);
1315 if (avail_out <= 0)
1317 obstack_finish (ob);
1318 f = frag_alloc (ob);
1319 f->fr_type = rs_fill;
1320 (*last_newf)->fr_next = f;
1321 *last_newf = f;
1322 avail_out = obstack_room (ob);
1324 if (avail_out <= 0)
1325 as_fatal (_("can't extend frag"));
1326 next_out = obstack_next_free (ob);
1327 obstack_blank_fast (ob, avail_out);
1328 out_size = compress_data (strm, &contents, &in_size,
1329 &next_out, &avail_out);
1330 if (out_size < 0)
1331 return -1;
1333 f->fr_fix += out_size;
1334 total_out_size += out_size;
1336 /* Return unused space. */
1337 if (avail_out > 0)
1338 obstack_blank_fast (ob, -avail_out);
1341 return total_out_size;
1344 static void
1345 compress_debug (bfd *abfd, asection *sec, void *xxx ATTRIBUTE_UNUSED)
1347 segment_info_type *seginfo = seg_info (sec);
1348 fragS *f;
1349 fragS *first_newf;
1350 fragS *last_newf;
1351 struct obstack *ob = &seginfo->frchainP->frch_obstack;
1352 bfd_size_type uncompressed_size = (bfd_size_type) sec->size;
1353 bfd_size_type compressed_size;
1354 const char *section_name;
1355 char *compressed_name;
1356 char *header;
1357 struct z_stream_s *strm;
1358 int x;
1359 flagword flags = bfd_get_section_flags (abfd, sec);
1361 if (seginfo == NULL
1362 || sec->size < 32
1363 || (flags & (SEC_ALLOC | SEC_HAS_CONTENTS)) == SEC_ALLOC)
1364 return;
1366 section_name = bfd_get_section_name (stdoutput, sec);
1367 if (strncmp (section_name, ".debug_", 7) != 0)
1368 return;
1370 strm = compress_init ();
1371 if (strm == NULL)
1372 return;
1374 /* Create a new frag to contain the "ZLIB" header. */
1375 first_newf = frag_alloc (ob);
1376 if (obstack_room (ob) < 12)
1377 first_newf = frag_alloc (ob);
1378 if (obstack_room (ob) < 12)
1379 as_fatal (_("can't extend frag %u chars"), 12);
1380 last_newf = first_newf;
1381 obstack_blank_fast (ob, 12);
1382 last_newf->fr_type = rs_fill;
1383 last_newf->fr_fix = 12;
1384 header = last_newf->fr_literal;
1385 memcpy (header, "ZLIB", 4);
1386 header[11] = uncompressed_size; uncompressed_size >>= 8;
1387 header[10] = uncompressed_size; uncompressed_size >>= 8;
1388 header[9] = uncompressed_size; uncompressed_size >>= 8;
1389 header[8] = uncompressed_size; uncompressed_size >>= 8;
1390 header[7] = uncompressed_size; uncompressed_size >>= 8;
1391 header[6] = uncompressed_size; uncompressed_size >>= 8;
1392 header[5] = uncompressed_size; uncompressed_size >>= 8;
1393 header[4] = uncompressed_size;
1394 compressed_size = 12;
1396 /* Stream the frags through the compression engine, adding new frags
1397 as necessary to accomodate the compressed output. */
1398 for (f = seginfo->frchainP->frch_root;
1400 f = f->fr_next)
1402 offsetT fill_size;
1403 char *fill_literal;
1404 offsetT count;
1405 int out_size;
1407 gas_assert (f->fr_type == rs_fill);
1408 if (f->fr_fix)
1410 out_size = compress_frag (strm, f->fr_literal, f->fr_fix,
1411 &last_newf, ob);
1412 if (out_size < 0)
1413 return;
1414 compressed_size += out_size;
1416 fill_literal = f->fr_literal + f->fr_fix;
1417 fill_size = f->fr_var;
1418 count = f->fr_offset;
1419 gas_assert (count >= 0);
1420 if (fill_size && count)
1422 while (count--)
1424 out_size = compress_frag (strm, fill_literal, (int) fill_size,
1425 &last_newf, ob);
1426 if (out_size < 0)
1427 return;
1428 compressed_size += out_size;
1433 /* Flush the compression state. */
1434 for (;;)
1436 int avail_out;
1437 char *next_out;
1438 int out_size;
1440 /* Reserve all the space available in the current chunk.
1441 If none is available, start a new frag. */
1442 avail_out = obstack_room (ob);
1443 if (avail_out <= 0)
1445 fragS *newf;
1447 obstack_finish (ob);
1448 newf = frag_alloc (ob);
1449 newf->fr_type = rs_fill;
1450 last_newf->fr_next = newf;
1451 last_newf = newf;
1452 avail_out = obstack_room (ob);
1454 if (avail_out <= 0)
1455 as_fatal (_("can't extend frag"));
1456 next_out = obstack_next_free (ob);
1457 obstack_blank_fast (ob, avail_out);
1458 x = compress_finish (strm, &next_out, &avail_out, &out_size);
1459 if (x < 0)
1460 return;
1462 last_newf->fr_fix += out_size;
1463 compressed_size += out_size;
1465 /* Return unused space. */
1466 if (avail_out > 0)
1467 obstack_blank_fast (ob, -avail_out);
1469 if (x == 0)
1470 break;
1473 /* Replace the uncompressed frag list with the compressed frag list. */
1474 seginfo->frchainP->frch_root = first_newf;
1475 seginfo->frchainP->frch_last = last_newf;
1477 /* Update the section size and its name. */
1478 x = bfd_set_section_size (abfd, sec, compressed_size);
1479 gas_assert (x);
1480 compressed_name = (char *) xmalloc (strlen (section_name) + 2);
1481 compressed_name[0] = '.';
1482 compressed_name[1] = 'z';
1483 strcpy (compressed_name + 2, section_name + 1);
1484 bfd_section_name (stdoutput, sec) = compressed_name;
1487 static void
1488 write_contents (bfd *abfd ATTRIBUTE_UNUSED,
1489 asection *sec,
1490 void *xxx ATTRIBUTE_UNUSED)
1492 segment_info_type *seginfo = seg_info (sec);
1493 addressT offset = 0;
1494 fragS *f;
1496 /* Write out the frags. */
1497 if (seginfo == NULL
1498 || !(bfd_get_section_flags (abfd, sec) & SEC_HAS_CONTENTS))
1499 return;
1501 for (f = seginfo->frchainP->frch_root;
1503 f = f->fr_next)
1505 int x;
1506 addressT fill_size;
1507 char *fill_literal;
1508 offsetT count;
1510 gas_assert (f->fr_type == rs_fill);
1511 if (f->fr_fix)
1513 x = bfd_set_section_contents (stdoutput, sec,
1514 f->fr_literal, (file_ptr) offset,
1515 (bfd_size_type) f->fr_fix);
1516 if (!x)
1517 as_fatal (_("can't write %s: %s"), stdoutput->filename,
1518 bfd_errmsg (bfd_get_error ()));
1519 offset += f->fr_fix;
1521 fill_literal = f->fr_literal + f->fr_fix;
1522 fill_size = f->fr_var;
1523 count = f->fr_offset;
1524 gas_assert (count >= 0);
1525 if (fill_size && count)
1527 char buf[256];
1528 if (fill_size > sizeof (buf))
1530 /* Do it the old way. Can this ever happen? */
1531 while (count--)
1533 x = bfd_set_section_contents (stdoutput, sec,
1534 fill_literal,
1535 (file_ptr) offset,
1536 (bfd_size_type) fill_size);
1537 if (!x)
1538 as_fatal (_("can't write %s: %s"), stdoutput->filename,
1539 bfd_errmsg (bfd_get_error ()));
1540 offset += fill_size;
1543 else
1545 /* Build a buffer full of fill objects and output it as
1546 often as necessary. This saves on the overhead of
1547 potentially lots of bfd_set_section_contents calls. */
1548 int n_per_buf, i;
1549 if (fill_size == 1)
1551 n_per_buf = sizeof (buf);
1552 memset (buf, *fill_literal, n_per_buf);
1554 else
1556 char *bufp;
1557 n_per_buf = sizeof (buf) / fill_size;
1558 for (i = n_per_buf, bufp = buf; i; i--, bufp += fill_size)
1559 memcpy (bufp, fill_literal, fill_size);
1561 for (; count > 0; count -= n_per_buf)
1563 n_per_buf = n_per_buf > count ? count : n_per_buf;
1564 x = bfd_set_section_contents
1565 (stdoutput, sec, buf, (file_ptr) offset,
1566 (bfd_size_type) n_per_buf * fill_size);
1567 if (!x)
1568 as_fatal (_("cannot write to output file '%s': %s"),
1569 stdoutput->filename,
1570 bfd_errmsg (bfd_get_error ()));
1571 offset += n_per_buf * fill_size;
1578 static void
1579 merge_data_into_text (void)
1581 seg_info (text_section)->frchainP->frch_last->fr_next =
1582 seg_info (data_section)->frchainP->frch_root;
1583 seg_info (text_section)->frchainP->frch_last =
1584 seg_info (data_section)->frchainP->frch_last;
1585 seg_info (data_section)->frchainP = 0;
1588 static void
1589 set_symtab (void)
1591 int nsyms;
1592 asymbol **asympp;
1593 symbolS *symp;
1594 bfd_boolean result;
1596 /* Count symbols. We can't rely on a count made by the loop in
1597 write_object_file, because *_frob_file may add a new symbol or
1598 two. */
1599 nsyms = 0;
1600 for (symp = symbol_rootP; symp; symp = symbol_next (symp))
1601 nsyms++;
1603 if (nsyms)
1605 int i;
1606 bfd_size_type amt = (bfd_size_type) nsyms * sizeof (asymbol *);
1608 asympp = (asymbol **) bfd_alloc (stdoutput, amt);
1609 symp = symbol_rootP;
1610 for (i = 0; i < nsyms; i++, symp = symbol_next (symp))
1612 asympp[i] = symbol_get_bfdsym (symp);
1613 if (asympp[i]->flags != BSF_SECTION_SYM
1614 || !(bfd_is_const_section (asympp[i]->section)
1615 && asympp[i]->section->symbol == asympp[i]))
1616 asympp[i]->flags |= BSF_KEEP;
1617 symbol_mark_written (symp);
1620 else
1621 asympp = 0;
1622 result = bfd_set_symtab (stdoutput, asympp, nsyms);
1623 gas_assert (result);
1624 symbol_table_frozen = 1;
1627 /* Finish the subsegments. After every sub-segment, we fake an
1628 ".align ...". This conforms to BSD4.2 brane-damage. We then fake
1629 ".fill 0" because that is the kind of frag that requires least
1630 thought. ".align" frags like to have a following frag since that
1631 makes calculating their intended length trivial. */
1633 #ifndef SUB_SEGMENT_ALIGN
1634 #ifdef HANDLE_ALIGN
1635 /* The last subsegment gets an alignment corresponding to the alignment
1636 of the section. This allows proper nop-filling at the end of
1637 code-bearing sections. */
1638 #define SUB_SEGMENT_ALIGN(SEG, FRCHAIN) \
1639 (!(FRCHAIN)->frch_next ? get_recorded_alignment (SEG) : 0)
1640 #else
1641 #define SUB_SEGMENT_ALIGN(SEG, FRCHAIN) 0
1642 #endif
1643 #endif
1645 void
1646 subsegs_finish (void)
1648 struct frchain *frchainP;
1649 asection *s;
1651 for (s = stdoutput->sections; s; s = s->next)
1653 segment_info_type *seginfo = seg_info (s);
1654 if (!seginfo)
1655 continue;
1657 for (frchainP = seginfo->frchainP;
1658 frchainP != NULL;
1659 frchainP = frchainP->frch_next)
1661 int alignment = 0;
1663 subseg_set (s, frchainP->frch_subseg);
1665 /* This now gets called even if we had errors. In that case,
1666 any alignment is meaningless, and, moreover, will look weird
1667 if we are generating a listing. */
1668 if (!had_errors ())
1670 alignment = SUB_SEGMENT_ALIGN (now_seg, frchainP);
1671 if ((bfd_get_section_flags (now_seg->owner, now_seg) & SEC_MERGE)
1672 && now_seg->entsize)
1674 unsigned int entsize = now_seg->entsize;
1675 int entalign = 0;
1677 while ((entsize & 1) == 0)
1679 ++entalign;
1680 entsize >>= 1;
1682 if (entalign > alignment)
1683 alignment = entalign;
1687 if (subseg_text_p (now_seg))
1688 frag_align_code (alignment, 0);
1689 else
1690 frag_align (alignment, 0, 0);
1692 /* frag_align will have left a new frag.
1693 Use this last frag for an empty ".fill".
1695 For this segment ...
1696 Create a last frag. Do not leave a "being filled in frag". */
1697 frag_wane (frag_now);
1698 frag_now->fr_fix = 0;
1699 know (frag_now->fr_next == NULL);
1704 /* Write the object file. */
1706 void
1707 write_object_file (void)
1709 struct relax_seg_info rsi;
1710 #ifndef WORKING_DOT_WORD
1711 fragS *fragP; /* Track along all frags. */
1712 #endif
1714 /* Do we really want to write it? */
1716 int n_warns, n_errs;
1717 n_warns = had_warnings ();
1718 n_errs = had_errors ();
1719 /* The -Z flag indicates that an object file should be generated,
1720 regardless of warnings and errors. */
1721 if (flag_always_generate_output)
1723 if (n_warns || n_errs)
1724 as_warn (_("%d error%s, %d warning%s, generating bad object file"),
1725 n_errs, n_errs == 1 ? "" : "s",
1726 n_warns, n_warns == 1 ? "" : "s");
1728 else
1730 if (n_errs)
1731 as_fatal (_("%d error%s, %d warning%s, no object file generated"),
1732 n_errs, n_errs == 1 ? "" : "s",
1733 n_warns, n_warns == 1 ? "" : "s");
1737 #ifdef OBJ_VMS
1738 /* Under VMS we try to be compatible with VAX-11 "C". Thus, we call
1739 a routine to check for the definition of the procedure "_main",
1740 and if so -- fix it up so that it can be program entry point. */
1741 vms_check_for_main ();
1742 #endif /* OBJ_VMS */
1744 /* From now on, we don't care about sub-segments. Build one frag chain
1745 for each segment. Linked thru fr_next. */
1747 /* Remove the sections created by gas for its own purposes. */
1749 int i;
1751 bfd_section_list_remove (stdoutput, reg_section);
1752 bfd_section_list_remove (stdoutput, expr_section);
1753 stdoutput->section_count -= 2;
1754 i = 0;
1755 bfd_map_over_sections (stdoutput, renumber_sections, &i);
1758 bfd_map_over_sections (stdoutput, chain_frchains_together, (char *) 0);
1760 /* We have two segments. If user gave -R flag, then we must put the
1761 data frags into the text segment. Do this before relaxing so
1762 we know to take advantage of -R and make shorter addresses. */
1763 if (flag_readonly_data_in_text)
1765 merge_data_into_text ();
1768 rsi.pass = 0;
1769 while (1)
1771 #ifndef WORKING_DOT_WORD
1772 /* We need to reset the markers in the broken word list and
1773 associated frags between calls to relax_segment (via
1774 relax_seg). Since the broken word list is global, we do it
1775 once per round, rather than locally in relax_segment for each
1776 segment. */
1777 struct broken_word *brokp;
1779 for (brokp = broken_words;
1780 brokp != (struct broken_word *) NULL;
1781 brokp = brokp->next_broken_word)
1783 brokp->added = 0;
1785 if (brokp->dispfrag != (fragS *) NULL
1786 && brokp->dispfrag->fr_type == rs_broken_word)
1787 brokp->dispfrag->fr_subtype = 0;
1789 #endif
1791 rsi.changed = 0;
1792 bfd_map_over_sections (stdoutput, relax_seg, &rsi);
1793 rsi.pass++;
1794 if (!rsi.changed)
1795 break;
1798 /* Note - Most ports will use the default value of
1799 TC_FINALIZE_SYMS_BEFORE_SIZE_SEG, which 1. This will force
1800 local symbols to be resolved, removing their frag information.
1801 Some ports however, will not have finished relaxing all of
1802 their frags and will still need the local symbol frag
1803 information. These ports can set
1804 TC_FINALIZE_SYMS_BEFORE_SIZE_SEG to 0. */
1805 finalize_syms = TC_FINALIZE_SYMS_BEFORE_SIZE_SEG;
1807 bfd_map_over_sections (stdoutput, size_seg, (char *) 0);
1809 /* Relaxation has completed. Freeze all syms. */
1810 finalize_syms = 1;
1812 #ifdef md_post_relax_hook
1813 md_post_relax_hook;
1814 #endif
1816 #ifndef WORKING_DOT_WORD
1818 struct broken_word *lie;
1819 struct broken_word **prevP;
1821 prevP = &broken_words;
1822 for (lie = broken_words; lie; lie = lie->next_broken_word)
1823 if (!lie->added)
1825 expressionS exp;
1827 subseg_change (lie->seg, lie->subseg);
1828 exp.X_op = O_subtract;
1829 exp.X_add_symbol = lie->add;
1830 exp.X_op_symbol = lie->sub;
1831 exp.X_add_number = lie->addnum;
1832 #ifdef TC_CONS_FIX_NEW
1833 TC_CONS_FIX_NEW (lie->frag,
1834 lie->word_goes_here - lie->frag->fr_literal,
1835 2, &exp);
1836 #else
1837 fix_new_exp (lie->frag,
1838 lie->word_goes_here - lie->frag->fr_literal,
1839 2, &exp, 0, BFD_RELOC_16);
1840 #endif
1841 *prevP = lie->next_broken_word;
1843 else
1844 prevP = &(lie->next_broken_word);
1846 for (lie = broken_words; lie;)
1848 struct broken_word *untruth;
1849 char *table_ptr;
1850 addressT table_addr;
1851 addressT from_addr, to_addr;
1852 int n, m;
1854 subseg_change (lie->seg, lie->subseg);
1855 fragP = lie->dispfrag;
1857 /* Find out how many broken_words go here. */
1858 n = 0;
1859 for (untruth = lie;
1860 untruth && untruth->dispfrag == fragP;
1861 untruth = untruth->next_broken_word)
1862 if (untruth->added == 1)
1863 n++;
1865 table_ptr = lie->dispfrag->fr_opcode;
1866 table_addr = (lie->dispfrag->fr_address
1867 + (table_ptr - lie->dispfrag->fr_literal));
1868 /* Create the jump around the long jumps. This is a short
1869 jump from table_ptr+0 to table_ptr+n*long_jump_size. */
1870 from_addr = table_addr;
1871 to_addr = table_addr + md_short_jump_size + n * md_long_jump_size;
1872 md_create_short_jump (table_ptr, from_addr, to_addr, lie->dispfrag,
1873 lie->add);
1874 table_ptr += md_short_jump_size;
1875 table_addr += md_short_jump_size;
1877 for (m = 0;
1878 lie && lie->dispfrag == fragP;
1879 m++, lie = lie->next_broken_word)
1881 if (lie->added == 2)
1882 continue;
1883 /* Patch the jump table. */
1884 for (untruth = (struct broken_word *) (fragP->fr_symbol);
1885 untruth && untruth->dispfrag == fragP;
1886 untruth = untruth->next_broken_word)
1888 if (untruth->use_jump == lie)
1890 /* This is the offset from ??? to table_ptr+0.
1891 The target is the same for all users of this
1892 md_long_jump, but the "sub" bases (and hence the
1893 offsets) may be different. */
1894 addressT to_word = table_addr - S_GET_VALUE (untruth->sub);
1895 #ifdef TC_CHECK_ADJUSTED_BROKEN_DOT_WORD
1896 TC_CHECK_ADJUSTED_BROKEN_DOT_WORD (to_word, untruth);
1897 #endif
1898 md_number_to_chars (untruth->word_goes_here, to_word, 2);
1902 /* Install the long jump. */
1903 /* This is a long jump from table_ptr+0 to the final target. */
1904 from_addr = table_addr;
1905 to_addr = S_GET_VALUE (lie->add) + lie->addnum;
1906 md_create_long_jump (table_ptr, from_addr, to_addr, lie->dispfrag,
1907 lie->add);
1908 table_ptr += md_long_jump_size;
1909 table_addr += md_long_jump_size;
1913 #endif /* not WORKING_DOT_WORD */
1915 /* Resolve symbol values. This needs to be done before processing
1916 the relocations. */
1917 if (symbol_rootP)
1919 symbolS *symp;
1921 for (symp = symbol_rootP; symp; symp = symbol_next (symp))
1922 resolve_symbol_value (symp);
1924 resolve_local_symbol_values ();
1925 resolve_reloc_expr_symbols ();
1927 PROGRESS (1);
1929 #ifdef tc_frob_file_before_adjust
1930 tc_frob_file_before_adjust ();
1931 #endif
1932 #ifdef obj_frob_file_before_adjust
1933 obj_frob_file_before_adjust ();
1934 #endif
1936 bfd_map_over_sections (stdoutput, adjust_reloc_syms, (char *) 0);
1938 #ifdef tc_frob_file_before_fix
1939 tc_frob_file_before_fix ();
1940 #endif
1941 #ifdef obj_frob_file_before_fix
1942 obj_frob_file_before_fix ();
1943 #endif
1945 bfd_map_over_sections (stdoutput, fix_segment, (char *) 0);
1947 /* Set up symbol table, and write it out. */
1948 if (symbol_rootP)
1950 symbolS *symp;
1951 bfd_boolean skip_next_symbol = FALSE;
1953 for (symp = symbol_rootP; symp; symp = symbol_next (symp))
1955 int punt = 0;
1956 const char *name;
1958 if (skip_next_symbol)
1960 /* Don't do anything besides moving the value of the
1961 symbol from the GAS value-field to the BFD value-field. */
1962 symbol_get_bfdsym (symp)->value = S_GET_VALUE (symp);
1963 skip_next_symbol = FALSE;
1964 continue;
1967 if (symbol_mri_common_p (symp))
1969 if (S_IS_EXTERNAL (symp))
1970 as_bad (_("%s: global symbols not supported in common sections"),
1971 S_GET_NAME (symp));
1972 symbol_remove (symp, &symbol_rootP, &symbol_lastP);
1973 continue;
1976 name = S_GET_NAME (symp);
1977 if (name)
1979 const char *name2 =
1980 decode_local_label_name ((char *) S_GET_NAME (symp));
1981 /* They only differ if `name' is a fb or dollar local
1982 label name. */
1983 if (name2 != name && ! S_IS_DEFINED (symp))
1984 as_bad (_("local label `%s' is not defined"), name2);
1987 /* Do it again, because adjust_reloc_syms might introduce
1988 more symbols. They'll probably only be section symbols,
1989 but they'll still need to have the values computed. */
1990 resolve_symbol_value (symp);
1992 /* Skip symbols which were equated to undefined or common
1993 symbols. */
1994 if (symbol_equated_reloc_p (symp)
1995 || S_IS_WEAKREFR (symp))
1997 const char *sname = S_GET_NAME (symp);
1999 if (S_IS_COMMON (symp)
2000 && !TC_FAKE_LABEL (sname)
2001 && !S_IS_WEAKREFR (symp)
2002 && (!S_IS_EXTERNAL (symp) || S_IS_LOCAL (symp)))
2004 expressionS *e = symbol_get_value_expression (symp);
2006 as_bad (_("Local symbol `%s' can't be equated to common symbol `%s'"),
2007 sname, S_GET_NAME (e->X_add_symbol));
2009 if (S_GET_SEGMENT (symp) == reg_section)
2011 /* Report error only if we know the symbol name. */
2012 if (S_GET_NAME (symp) != reg_section->name)
2013 as_bad (_("can't make global register symbol `%s'"),
2014 sname);
2016 symbol_remove (symp, &symbol_rootP, &symbol_lastP);
2017 continue;
2020 #ifdef obj_frob_symbol
2021 obj_frob_symbol (symp, punt);
2022 #endif
2023 #ifdef tc_frob_symbol
2024 if (! punt || symbol_used_in_reloc_p (symp))
2025 tc_frob_symbol (symp, punt);
2026 #endif
2028 /* If we don't want to keep this symbol, splice it out of
2029 the chain now. If EMIT_SECTION_SYMBOLS is 0, we never
2030 want section symbols. Otherwise, we skip local symbols
2031 and symbols that the frob_symbol macros told us to punt,
2032 but we keep such symbols if they are used in relocs. */
2033 if (symp == abs_section_sym
2034 || (! EMIT_SECTION_SYMBOLS
2035 && symbol_section_p (symp))
2036 /* Note that S_IS_EXTERNAL and S_IS_LOCAL are not always
2037 opposites. Sometimes the former checks flags and the
2038 latter examines the name... */
2039 || (!S_IS_EXTERNAL (symp)
2040 && (punt || S_IS_LOCAL (symp) ||
2041 (S_IS_WEAKREFD (symp) && ! symbol_used_p (symp)))
2042 && ! symbol_used_in_reloc_p (symp)))
2044 symbol_remove (symp, &symbol_rootP, &symbol_lastP);
2046 /* After symbol_remove, symbol_next(symp) still returns
2047 the one that came after it in the chain. So we don't
2048 need to do any extra cleanup work here. */
2049 continue;
2052 /* Make sure we really got a value for the symbol. */
2053 if (! symbol_resolved_p (symp))
2055 as_bad (_("can't resolve value for symbol `%s'"),
2056 S_GET_NAME (symp));
2057 symbol_mark_resolved (symp);
2060 /* Set the value into the BFD symbol. Up til now the value
2061 has only been kept in the gas symbolS struct. */
2062 symbol_get_bfdsym (symp)->value = S_GET_VALUE (symp);
2064 /* A warning construct is a warning symbol followed by the
2065 symbol warned about. Don't let anything object-format or
2066 target-specific muck with it; it's ready for output. */
2067 if (symbol_get_bfdsym (symp)->flags & BSF_WARNING)
2068 skip_next_symbol = TRUE;
2072 PROGRESS (1);
2074 /* Now do any format-specific adjustments to the symbol table, such
2075 as adding file symbols. */
2076 #ifdef tc_adjust_symtab
2077 tc_adjust_symtab ();
2078 #endif
2079 #ifdef obj_adjust_symtab
2080 obj_adjust_symtab ();
2081 #endif
2083 /* Stop if there is an error. */
2084 if (had_errors ())
2085 return;
2087 /* Now that all the sizes are known, and contents correct, we can
2088 start writing to the file. */
2089 set_symtab ();
2091 /* If *_frob_file changes the symbol value at this point, it is
2092 responsible for moving the changed value into symp->bsym->value
2093 as well. Hopefully all symbol value changing can be done in
2094 *_frob_symbol. */
2095 #ifdef tc_frob_file
2096 tc_frob_file ();
2097 #endif
2098 #ifdef obj_frob_file
2099 obj_frob_file ();
2100 #endif
2101 #ifdef obj_coff_generate_pdata
2102 obj_coff_generate_pdata ();
2103 #endif
2104 bfd_map_over_sections (stdoutput, write_relocs, (char *) 0);
2106 #ifdef tc_frob_file_after_relocs
2107 tc_frob_file_after_relocs ();
2108 #endif
2109 #ifdef obj_frob_file_after_relocs
2110 obj_frob_file_after_relocs ();
2111 #endif
2113 /* Once all relocations have been written, we can compress the
2114 contents of the debug sections. This needs to be done before
2115 we start writing any sections, because it will affect the file
2116 layout, which is fixed once we start writing contents. */
2117 if (flag_compress_debug)
2118 bfd_map_over_sections (stdoutput, compress_debug, (char *) 0);
2120 bfd_map_over_sections (stdoutput, write_contents, (char *) 0);
2123 #ifdef TC_GENERIC_RELAX_TABLE
2124 /* Relax a fragment by scanning TC_GENERIC_RELAX_TABLE. */
2126 long
2127 relax_frag (segT segment, fragS *fragP, long stretch)
2129 const relax_typeS *this_type;
2130 const relax_typeS *start_type;
2131 relax_substateT next_state;
2132 relax_substateT this_state;
2133 offsetT growth;
2134 offsetT aim;
2135 addressT target;
2136 addressT address;
2137 symbolS *symbolP;
2138 const relax_typeS *table;
2140 target = fragP->fr_offset;
2141 address = fragP->fr_address;
2142 table = TC_GENERIC_RELAX_TABLE;
2143 this_state = fragP->fr_subtype;
2144 start_type = this_type = table + this_state;
2145 symbolP = fragP->fr_symbol;
2147 if (symbolP)
2149 fragS *sym_frag;
2151 sym_frag = symbol_get_frag (symbolP);
2153 #ifndef DIFF_EXPR_OK
2154 know (sym_frag != NULL);
2155 #endif
2156 know (S_GET_SEGMENT (symbolP) != absolute_section
2157 || sym_frag == &zero_address_frag);
2158 target += S_GET_VALUE (symbolP);
2160 /* If SYM_FRAG has yet to be reached on this pass, assume it
2161 will move by STRETCH just as we did, unless there is an
2162 alignment frag between here and SYM_FRAG. An alignment may
2163 well absorb any STRETCH, and we don't want to choose a larger
2164 branch insn by overestimating the needed reach of this
2165 branch. It isn't critical to calculate TARGET exactly; We
2166 know we'll be doing another pass if STRETCH is non-zero. */
2168 if (stretch != 0
2169 && sym_frag->relax_marker != fragP->relax_marker
2170 && S_GET_SEGMENT (symbolP) == segment)
2172 if (stretch < 0
2173 || sym_frag->region == fragP->region)
2174 target += stretch;
2175 /* If we get here we know we have a forward branch. This
2176 relax pass may have stretched previous instructions so
2177 far that omitting STRETCH would make the branch
2178 negative. Don't allow this in case the negative reach is
2179 large enough to require a larger branch instruction. */
2180 else if (target < address)
2181 target = fragP->fr_next->fr_address + stretch;
2185 aim = target - address - fragP->fr_fix;
2186 #ifdef TC_PCREL_ADJUST
2187 /* Currently only the ns32k family needs this. */
2188 aim += TC_PCREL_ADJUST (fragP);
2189 #endif
2191 #ifdef md_prepare_relax_scan
2192 /* Formerly called M68K_AIM_KLUDGE. */
2193 md_prepare_relax_scan (fragP, address, aim, this_state, this_type);
2194 #endif
2196 if (aim < 0)
2198 /* Look backwards. */
2199 for (next_state = this_type->rlx_more; next_state;)
2200 if (aim >= this_type->rlx_backward)
2201 next_state = 0;
2202 else
2204 /* Grow to next state. */
2205 this_state = next_state;
2206 this_type = table + this_state;
2207 next_state = this_type->rlx_more;
2210 else
2212 /* Look forwards. */
2213 for (next_state = this_type->rlx_more; next_state;)
2214 if (aim <= this_type->rlx_forward)
2215 next_state = 0;
2216 else
2218 /* Grow to next state. */
2219 this_state = next_state;
2220 this_type = table + this_state;
2221 next_state = this_type->rlx_more;
2225 growth = this_type->rlx_length - start_type->rlx_length;
2226 if (growth != 0)
2227 fragP->fr_subtype = this_state;
2228 return growth;
2231 #endif /* defined (TC_GENERIC_RELAX_TABLE) */
2233 /* Relax_align. Advance location counter to next address that has 'alignment'
2234 lowest order bits all 0s, return size of adjustment made. */
2235 static relax_addressT
2236 relax_align (register relax_addressT address, /* Address now. */
2237 register int alignment /* Alignment (binary). */)
2239 relax_addressT mask;
2240 relax_addressT new_address;
2242 mask = ~((~0) << alignment);
2243 new_address = (address + mask) & (~mask);
2244 #ifdef LINKER_RELAXING_SHRINKS_ONLY
2245 if (linkrelax)
2246 /* We must provide lots of padding, so the linker can discard it
2247 when needed. The linker will not add extra space, ever. */
2248 new_address += (1 << alignment);
2249 #endif
2250 return (new_address - address);
2253 /* Now we have a segment, not a crowd of sub-segments, we can make
2254 fr_address values.
2256 Relax the frags.
2258 After this, all frags in this segment have addresses that are correct
2259 within the segment. Since segments live in different file addresses,
2260 these frag addresses may not be the same as final object-file
2261 addresses. */
2264 relax_segment (struct frag *segment_frag_root, segT segment, int pass)
2266 unsigned long frag_count;
2267 struct frag *fragP;
2268 relax_addressT address;
2269 int region;
2270 int ret;
2272 /* In case md_estimate_size_before_relax() wants to make fixSs. */
2273 subseg_change (segment, 0);
2275 /* For each frag in segment: count and store (a 1st guess of)
2276 fr_address. */
2277 address = 0;
2278 region = 0;
2279 for (frag_count = 0, fragP = segment_frag_root;
2280 fragP;
2281 fragP = fragP->fr_next, frag_count ++)
2283 fragP->region = region;
2284 fragP->relax_marker = 0;
2285 fragP->fr_address = address;
2286 address += fragP->fr_fix;
2288 switch (fragP->fr_type)
2290 case rs_fill:
2291 address += fragP->fr_offset * fragP->fr_var;
2292 break;
2294 case rs_align:
2295 case rs_align_code:
2296 case rs_align_test:
2298 addressT offset = relax_align (address, (int) fragP->fr_offset);
2300 if (fragP->fr_subtype != 0 && offset > fragP->fr_subtype)
2301 offset = 0;
2303 if (offset % fragP->fr_var != 0)
2305 as_bad_where (fragP->fr_file, fragP->fr_line,
2306 _("alignment padding (%lu bytes) not a multiple of %ld"),
2307 (unsigned long) offset, (long) fragP->fr_var);
2308 offset -= (offset % fragP->fr_var);
2311 address += offset;
2312 region += 1;
2314 break;
2316 case rs_org:
2317 /* Assume .org is nugatory. It will grow with 1st relax. */
2318 region += 1;
2319 break;
2321 case rs_space:
2322 break;
2324 case rs_machine_dependent:
2325 /* If fr_symbol is an expression, this call to
2326 resolve_symbol_value sets up the correct segment, which will
2327 likely be needed in md_estimate_size_before_relax. */
2328 if (fragP->fr_symbol)
2329 resolve_symbol_value (fragP->fr_symbol);
2331 address += md_estimate_size_before_relax (fragP, segment);
2332 break;
2334 #ifndef WORKING_DOT_WORD
2335 /* Broken words don't concern us yet. */
2336 case rs_broken_word:
2337 break;
2338 #endif
2340 case rs_leb128:
2341 /* Initial guess is always 1; doing otherwise can result in
2342 stable solutions that are larger than the minimum. */
2343 address += fragP->fr_offset = 1;
2344 break;
2346 case rs_cfa:
2347 address += eh_frame_estimate_size_before_relax (fragP);
2348 break;
2350 case rs_dwarf2dbg:
2351 address += dwarf2dbg_estimate_size_before_relax (fragP);
2352 break;
2354 default:
2355 BAD_CASE (fragP->fr_type);
2356 break;
2360 /* Do relax(). */
2362 unsigned long max_iterations;
2364 /* Cumulative address adjustment. */
2365 offsetT stretch;
2367 /* Have we made any adjustment this pass? We can't just test
2368 stretch because one piece of code may have grown and another
2369 shrank. */
2370 int stretched;
2372 /* Most horrible, but gcc may give us some exception data that
2373 is impossible to assemble, of the form
2375 .align 4
2376 .byte 0, 0
2377 .uleb128 end - start
2378 start:
2379 .space 128*128 - 1
2380 .align 4
2381 end:
2383 If the leb128 is two bytes in size, then end-start is 128*128,
2384 which requires a three byte leb128. If the leb128 is three
2385 bytes in size, then end-start is 128*128-1, which requires a
2386 two byte leb128. We work around this dilemma by inserting
2387 an extra 4 bytes of alignment just after the .align. This
2388 works because the data after the align is accessed relative to
2389 the end label.
2391 This counter is used in a tiny state machine to detect
2392 whether a leb128 followed by an align is impossible to
2393 relax. */
2394 int rs_leb128_fudge = 0;
2396 /* We want to prevent going into an infinite loop where one frag grows
2397 depending upon the location of a symbol which is in turn moved by
2398 the growing frag. eg:
2400 foo = .
2401 .org foo+16
2402 foo = .
2404 So we dictate that this algorithm can be at most O2. */
2405 max_iterations = frag_count * frag_count;
2406 /* Check for overflow. */
2407 if (max_iterations < frag_count)
2408 max_iterations = frag_count;
2410 ret = 0;
2413 stretch = 0;
2414 stretched = 0;
2416 for (fragP = segment_frag_root; fragP; fragP = fragP->fr_next)
2418 offsetT growth = 0;
2419 addressT was_address;
2420 offsetT offset;
2421 symbolS *symbolP;
2423 fragP->relax_marker ^= 1;
2424 was_address = fragP->fr_address;
2425 address = fragP->fr_address += stretch;
2426 symbolP = fragP->fr_symbol;
2427 offset = fragP->fr_offset;
2429 switch (fragP->fr_type)
2431 case rs_fill: /* .fill never relaxes. */
2432 growth = 0;
2433 break;
2435 #ifndef WORKING_DOT_WORD
2436 /* JF: This is RMS's idea. I do *NOT* want to be blamed
2437 for it I do not want to write it. I do not want to have
2438 anything to do with it. This is not the proper way to
2439 implement this misfeature. */
2440 case rs_broken_word:
2442 struct broken_word *lie;
2443 struct broken_word *untruth;
2445 /* Yes this is ugly (storing the broken_word pointer
2446 in the symbol slot). Still, this whole chunk of
2447 code is ugly, and I don't feel like doing anything
2448 about it. Think of it as stubbornness in action. */
2449 growth = 0;
2450 for (lie = (struct broken_word *) (fragP->fr_symbol);
2451 lie && lie->dispfrag == fragP;
2452 lie = lie->next_broken_word)
2455 if (lie->added)
2456 continue;
2458 offset = (S_GET_VALUE (lie->add)
2459 + lie->addnum
2460 - S_GET_VALUE (lie->sub));
2461 if (offset <= -32768 || offset >= 32767)
2463 if (flag_warn_displacement)
2465 char buf[50];
2466 sprint_value (buf, (addressT) lie->addnum);
2467 as_warn_where (fragP->fr_file, fragP->fr_line,
2468 _(".word %s-%s+%s didn't fit"),
2469 S_GET_NAME (lie->add),
2470 S_GET_NAME (lie->sub),
2471 buf);
2473 if (fragP->fr_subtype == 0)
2475 fragP->fr_subtype++;
2476 growth += md_short_jump_size;
2479 /* Redirect *all* words of this table with the same
2480 target, lest we have to handle the case where the
2481 same target but with a offset that fits on this
2482 round overflows at the next relaxation round. */
2483 for (untruth = (struct broken_word *) (fragP->fr_symbol);
2484 untruth && untruth->dispfrag == lie->dispfrag;
2485 untruth = untruth->next_broken_word)
2486 if ((symbol_get_frag (untruth->add)
2487 == symbol_get_frag (lie->add))
2488 && (S_GET_VALUE (untruth->add)
2489 == S_GET_VALUE (lie->add)))
2491 untruth->added = 2;
2492 untruth->use_jump = lie;
2495 lie->added = 1;
2496 growth += md_long_jump_size;
2500 break;
2501 } /* case rs_broken_word */
2502 #endif
2503 case rs_align:
2504 case rs_align_code:
2505 case rs_align_test:
2507 addressT oldoff, newoff;
2509 oldoff = relax_align (was_address + fragP->fr_fix,
2510 (int) offset);
2511 newoff = relax_align (address + fragP->fr_fix,
2512 (int) offset);
2514 if (fragP->fr_subtype != 0)
2516 if (oldoff > fragP->fr_subtype)
2517 oldoff = 0;
2518 if (newoff > fragP->fr_subtype)
2519 newoff = 0;
2522 growth = newoff - oldoff;
2524 /* If this align happens to follow a leb128 and
2525 we have determined that the leb128 is bouncing
2526 in size, then break the cycle by inserting an
2527 extra alignment. */
2528 if (growth < 0
2529 && (rs_leb128_fudge & 16) != 0
2530 && (rs_leb128_fudge & 15) >= 2)
2532 segment_info_type *seginfo = seg_info (segment);
2533 struct obstack *ob = &seginfo->frchainP->frch_obstack;
2534 struct frag *newf;
2536 newf = frag_alloc (ob);
2537 obstack_blank_fast (ob, fragP->fr_var);
2538 obstack_finish (ob);
2539 memcpy (newf, fragP, SIZEOF_STRUCT_FRAG);
2540 memcpy (newf->fr_literal,
2541 fragP->fr_literal + fragP->fr_fix,
2542 fragP->fr_var);
2543 newf->fr_type = rs_fill;
2544 newf->fr_address = address + fragP->fr_fix + newoff;
2545 newf->fr_fix = 0;
2546 newf->fr_offset = (((offsetT) 1 << fragP->fr_offset)
2547 / fragP->fr_var);
2548 if (newf->fr_offset * newf->fr_var
2549 != (offsetT) 1 << fragP->fr_offset)
2551 newf->fr_offset = (offsetT) 1 << fragP->fr_offset;
2552 newf->fr_var = 1;
2554 /* Include size of new frag in GROWTH. */
2555 growth += newf->fr_offset * newf->fr_var;
2556 /* Adjust the new frag address for the amount
2557 we'll add when we process the new frag. */
2558 newf->fr_address -= stretch + growth;
2559 newf->relax_marker ^= 1;
2560 fragP->fr_next = newf;
2561 #ifdef DEBUG
2562 as_warn (_("padding added"));
2563 #endif
2566 break;
2568 case rs_org:
2570 addressT target = offset;
2571 addressT after;
2573 if (symbolP)
2575 /* Convert from an actual address to an octet offset
2576 into the section. Here it is assumed that the
2577 section's VMA is zero, and can omit subtracting it
2578 from the symbol's value to get the address offset. */
2579 know (S_GET_SEGMENT (symbolP)->vma == 0);
2580 target += S_GET_VALUE (symbolP) * OCTETS_PER_BYTE;
2583 know (fragP->fr_next);
2584 after = fragP->fr_next->fr_address + stretch;
2585 growth = target - after;
2586 if (growth < 0)
2588 growth = 0;
2590 /* Don't error on first few frag relax passes.
2591 The symbol might be an expression involving
2592 symbol values from other sections. If those
2593 sections have not yet been processed their
2594 frags will all have zero addresses, so we
2595 will calculate incorrect values for them. The
2596 number of passes we allow before giving an
2597 error is somewhat arbitrary. It should be at
2598 least one, with larger values requiring
2599 increasingly contrived dependencies between
2600 frags to trigger a false error. */
2601 if (pass < 2)
2603 /* Force another pass. */
2604 ret = 1;
2605 break;
2608 /* Growth may be negative, but variable part of frag
2609 cannot have fewer than 0 chars. That is, we can't
2610 .org backwards. */
2611 as_bad_where (fragP->fr_file, fragP->fr_line,
2612 _("attempt to move .org backwards"));
2614 /* We've issued an error message. Change the
2615 frag to avoid cascading errors. */
2616 fragP->fr_type = rs_align;
2617 fragP->fr_subtype = 0;
2618 fragP->fr_offset = 0;
2619 fragP->fr_fix = after - address;
2622 break;
2624 case rs_space:
2625 growth = 0;
2626 if (symbolP)
2628 offsetT amount;
2630 amount = S_GET_VALUE (symbolP);
2631 if (S_GET_SEGMENT (symbolP) != absolute_section
2632 || S_IS_COMMON (symbolP)
2633 || ! S_IS_DEFINED (symbolP))
2635 as_bad_where (fragP->fr_file, fragP->fr_line,
2636 _(".space specifies non-absolute value"));
2637 /* Prevent repeat of this error message. */
2638 fragP->fr_symbol = 0;
2640 else if (amount < 0)
2642 /* Don't error on first few frag relax passes.
2643 See rs_org comment for a longer explanation. */
2644 if (pass < 2)
2646 ret = 1;
2647 break;
2650 as_warn_where (fragP->fr_file, fragP->fr_line,
2651 _(".space or .fill with negative value, ignored"));
2652 fragP->fr_symbol = 0;
2654 else
2655 growth = (was_address + fragP->fr_fix + amount
2656 - fragP->fr_next->fr_address);
2658 break;
2660 case rs_machine_dependent:
2661 #ifdef md_relax_frag
2662 growth = md_relax_frag (segment, fragP, stretch);
2663 #else
2664 #ifdef TC_GENERIC_RELAX_TABLE
2665 /* The default way to relax a frag is to look through
2666 TC_GENERIC_RELAX_TABLE. */
2667 growth = relax_frag (segment, fragP, stretch);
2668 #endif /* TC_GENERIC_RELAX_TABLE */
2669 #endif
2670 break;
2672 case rs_leb128:
2674 valueT value;
2675 offsetT size;
2677 value = resolve_symbol_value (fragP->fr_symbol);
2678 size = sizeof_leb128 (value, fragP->fr_subtype);
2679 growth = size - fragP->fr_offset;
2680 fragP->fr_offset = size;
2682 break;
2684 case rs_cfa:
2685 growth = eh_frame_relax_frag (fragP);
2686 break;
2688 case rs_dwarf2dbg:
2689 growth = dwarf2dbg_relax_frag (fragP);
2690 break;
2692 default:
2693 BAD_CASE (fragP->fr_type);
2694 break;
2696 if (growth)
2698 stretch += growth;
2699 stretched = 1;
2700 if (fragP->fr_type == rs_leb128)
2701 rs_leb128_fudge += 16;
2702 else if (fragP->fr_type == rs_align
2703 && (rs_leb128_fudge & 16) != 0
2704 && stretch == 0)
2705 rs_leb128_fudge += 16;
2706 else
2707 rs_leb128_fudge = 0;
2711 if (stretch == 0
2712 && (rs_leb128_fudge & 16) == 0
2713 && (rs_leb128_fudge & -16) != 0)
2714 rs_leb128_fudge += 1;
2715 else
2716 rs_leb128_fudge = 0;
2718 /* Until nothing further to relax. */
2719 while (stretched && -- max_iterations);
2721 if (stretched)
2722 as_fatal (_("Infinite loop encountered whilst attempting to compute the addresses of symbols in section %s"),
2723 segment_name (segment));
2726 for (fragP = segment_frag_root; fragP; fragP = fragP->fr_next)
2727 if (fragP->last_fr_address != fragP->fr_address)
2729 fragP->last_fr_address = fragP->fr_address;
2730 ret = 1;
2732 return ret;
2735 void
2736 number_to_chars_bigendian (char *buf, valueT val, int n)
2738 if (n <= 0)
2739 abort ();
2740 while (n--)
2742 buf[n] = val & 0xff;
2743 val >>= 8;
2747 void
2748 number_to_chars_littleendian (char *buf, valueT val, int n)
2750 if (n <= 0)
2751 abort ();
2752 while (n--)
2754 *buf++ = val & 0xff;
2755 val >>= 8;
2759 void
2760 write_print_statistics (FILE *file)
2762 fprintf (file, "fixups: %d\n", n_fixups);
2765 /* For debugging. */
2766 extern int indent_level;
2768 void
2769 print_fixup (fixS *fixp)
2771 indent_level = 1;
2772 fprintf (stderr, "fix ");
2773 fprintf_vma (stderr, (bfd_vma)((bfd_hostptr_t) fixp));
2774 fprintf (stderr, " %s:%d",fixp->fx_file, fixp->fx_line);
2775 if (fixp->fx_pcrel)
2776 fprintf (stderr, " pcrel");
2777 if (fixp->fx_pcrel_adjust)
2778 fprintf (stderr, " pcrel_adjust=%d", fixp->fx_pcrel_adjust);
2779 if (fixp->fx_im_disp)
2781 #ifdef TC_NS32K
2782 fprintf (stderr, " im_disp=%d", fixp->fx_im_disp);
2783 #else
2784 fprintf (stderr, " im_disp");
2785 #endif
2787 if (fixp->fx_tcbit)
2788 fprintf (stderr, " tcbit");
2789 if (fixp->fx_done)
2790 fprintf (stderr, " done");
2791 fprintf (stderr, "\n size=%d frag=", fixp->fx_size);
2792 fprintf_vma (stderr, (bfd_vma) ((bfd_hostptr_t) fixp->fx_frag));
2793 fprintf (stderr, " where=%ld offset=%lx addnumber=%lx",
2794 (long) fixp->fx_where,
2795 (unsigned long) fixp->fx_offset,
2796 (unsigned long) fixp->fx_addnumber);
2797 fprintf (stderr, "\n %s (%d)", bfd_get_reloc_code_name (fixp->fx_r_type),
2798 fixp->fx_r_type);
2799 if (fixp->fx_addsy)
2801 fprintf (stderr, "\n +<");
2802 print_symbol_value_1 (stderr, fixp->fx_addsy);
2803 fprintf (stderr, ">");
2805 if (fixp->fx_subsy)
2807 fprintf (stderr, "\n -<");
2808 print_symbol_value_1 (stderr, fixp->fx_subsy);
2809 fprintf (stderr, ">");
2811 fprintf (stderr, "\n");
2812 #ifdef TC_FIX_DATA_PRINT
2813 TC_FIX_DATA_PRINT (stderr, fixp);
2814 #endif