1 /* write.c - emit .o file
2 Copyright (C) 1986-2018 Free Software Foundation, Inc.
4 This file is part of GAS, the GNU Assembler.
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 3, or (at your option)
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.
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 the Free
18 Software Foundation, 51 Franklin Street - Fifth Floor, Boston, MA
21 /* This thing should be set up to do byte ordering correctly. But... */
26 #include "output-file.h"
27 #include "dwarf2dbg.h"
28 #include "compress-debug.h"
30 #ifndef TC_FORCE_RELOCATION
31 #define TC_FORCE_RELOCATION(FIX) \
32 (generic_force_reloc (FIX))
35 #ifndef TC_FORCE_RELOCATION_ABS
36 #define TC_FORCE_RELOCATION_ABS(FIX) \
37 (TC_FORCE_RELOCATION (FIX))
40 #define GENERIC_FORCE_RELOCATION_LOCAL(FIX) \
42 || TC_FORCE_RELOCATION (FIX))
43 #ifndef TC_FORCE_RELOCATION_LOCAL
44 #define TC_FORCE_RELOCATION_LOCAL GENERIC_FORCE_RELOCATION_LOCAL
47 #define GENERIC_FORCE_RELOCATION_SUB_SAME(FIX, SEG) \
49 #ifndef TC_FORCE_RELOCATION_SUB_SAME
50 #define TC_FORCE_RELOCATION_SUB_SAME GENERIC_FORCE_RELOCATION_SUB_SAME
53 #ifndef md_register_arithmetic
54 # define md_register_arithmetic 1
57 #ifndef TC_FORCE_RELOCATION_SUB_ABS
58 #define TC_FORCE_RELOCATION_SUB_ABS(FIX, SEG) \
59 (!md_register_arithmetic && (SEG) == reg_section)
62 #ifndef TC_FORCE_RELOCATION_SUB_LOCAL
64 #define TC_FORCE_RELOCATION_SUB_LOCAL(FIX, SEG) \
65 (!md_register_arithmetic && (SEG) == reg_section)
67 #define TC_FORCE_RELOCATION_SUB_LOCAL(FIX, SEG) 1
71 #ifndef TC_VALIDATE_FIX_SUB
72 #ifdef UNDEFINED_DIFFERENCE_OK
73 /* The PA needs this for PIC code generation. */
74 #define TC_VALIDATE_FIX_SUB(FIX, SEG) \
75 (md_register_arithmetic || (SEG) != reg_section)
77 #define TC_VALIDATE_FIX_SUB(FIX, SEG) \
78 ((md_register_arithmetic || (SEG) != reg_section) \
79 && ((FIX)->fx_r_type == BFD_RELOC_GPREL32 \
80 || (FIX)->fx_r_type == BFD_RELOC_GPREL16))
84 #ifndef TC_LINKRELAX_FIXUP
85 #define TC_LINKRELAX_FIXUP(SEG) 1
88 #ifndef MD_APPLY_SYM_VALUE
89 #define MD_APPLY_SYM_VALUE(FIX) 1
92 #ifndef TC_FINALIZE_SYMS_BEFORE_SIZE_SEG
93 #define TC_FINALIZE_SYMS_BEFORE_SIZE_SEG 1
96 #ifndef MD_PCREL_FROM_SECTION
97 #define MD_PCREL_FROM_SECTION(FIX, SEC) md_pcrel_from (FIX)
100 #ifndef TC_FAKE_LABEL
101 #define TC_FAKE_LABEL(NAME) (strcmp ((NAME), FAKE_LABEL_NAME) == 0)
104 /* Positive values of TC_FX_SIZE_SLACK allow a target to define
105 fixups that far past the end of a frag. Having such fixups
106 is of course most most likely a bug in setting fx_size correctly.
107 A negative value disables the fixup check entirely, which is
108 appropriate for something like the Renesas / SuperH SH_COUNT
110 #ifndef TC_FX_SIZE_SLACK
111 #define TC_FX_SIZE_SLACK(FIX) 0
114 /* Used to control final evaluation of expressions. */
115 int finalize_syms = 0;
117 int symbol_table_frozen;
119 symbolS *abs_section_sym;
121 /* Remember the value of dot when parsing expressions. */
124 /* The frag that dot_value is based from. */
127 /* Relocs generated by ".reloc" pseudo. */
128 struct reloc_list* reloc_list;
130 void print_fixup (fixS *);
132 /* We generally attach relocs to frag chains. However, after we have
133 chained these all together into a segment, any relocs we add after
134 that must be attached to a segment. This will include relocs added
135 in md_estimate_size_for_relax, for example. */
136 static int frags_chained = 0;
140 #define RELOC_ENUM enum bfd_reloc_code_real
142 /* Create a fixS in obstack 'notes'. */
145 fix_new_internal (fragS *frag, /* Which frag? */
146 int where, /* Where in that frag? */
147 int size, /* 1, 2, or 4 usually. */
148 symbolS *add_symbol, /* X_add_symbol. */
149 symbolS *sub_symbol, /* X_op_symbol. */
150 offsetT offset, /* X_add_number. */
151 int pcrel, /* TRUE if PC-relative relocation. */
152 RELOC_ENUM r_type /* Relocation type. */,
153 int at_beginning) /* Add to the start of the list? */
159 fixP = (fixS *) obstack_alloc (¬es, sizeof (fixS));
161 fixP->fx_frag = frag;
162 fixP->fx_where = where;
163 fixP->fx_size = size;
164 /* We've made fx_size a narrow field; check that it's wide enough. */
165 if (fixP->fx_size != size)
167 as_bad (_("field fx_size too small to hold %d"), size);
170 fixP->fx_addsy = add_symbol;
171 fixP->fx_subsy = sub_symbol;
172 fixP->fx_offset = offset;
173 fixP->fx_dot_value = dot_value;
174 fixP->fx_dot_frag = dot_frag;
175 fixP->fx_pcrel = pcrel;
176 fixP->fx_r_type = r_type;
177 fixP->fx_im_disp = 0;
178 fixP->fx_pcrel_adjust = 0;
179 fixP->fx_bit_fixP = 0;
180 fixP->fx_addnumber = 0;
184 fixP->fx_no_overflow = 0;
188 fixP->fx_cgen.insn = NULL;
189 fixP->fx_cgen.opinfo = 0;
193 TC_INIT_FIX_DATA (fixP);
196 fixP->fx_file = as_where (&fixP->fx_line);
200 fixS **seg_fix_rootP = (frags_chained
201 ? &seg_info (now_seg)->fix_root
202 : &frchain_now->fix_root);
203 fixS **seg_fix_tailP = (frags_chained
204 ? &seg_info (now_seg)->fix_tail
205 : &frchain_now->fix_tail);
209 fixP->fx_next = *seg_fix_rootP;
210 *seg_fix_rootP = fixP;
211 if (fixP->fx_next == NULL)
212 *seg_fix_tailP = fixP;
216 fixP->fx_next = NULL;
218 (*seg_fix_tailP)->fx_next = fixP;
220 *seg_fix_rootP = fixP;
221 *seg_fix_tailP = fixP;
228 /* Create a fixup relative to a symbol (plus a constant). */
231 fix_new (fragS *frag, /* Which frag? */
232 int where, /* Where in that frag? */
233 int size, /* 1, 2, or 4 usually. */
234 symbolS *add_symbol, /* X_add_symbol. */
235 offsetT offset, /* X_add_number. */
236 int pcrel, /* TRUE if PC-relative relocation. */
237 RELOC_ENUM r_type /* Relocation type. */)
239 return fix_new_internal (frag, where, size, add_symbol,
240 (symbolS *) NULL, offset, pcrel, r_type, FALSE);
243 /* Create a fixup for an expression. Currently we only support fixups
244 for difference expressions. That is itself more than most object
245 file formats support anyhow. */
248 fix_new_exp (fragS *frag, /* Which frag? */
249 int where, /* Where in that frag? */
250 int size, /* 1, 2, or 4 usually. */
251 expressionS *exp, /* Expression. */
252 int pcrel, /* TRUE if PC-relative relocation. */
253 RELOC_ENUM r_type /* Relocation type. */)
265 as_bad (_("register value used as expression"));
269 /* This comes up when _GLOBAL_OFFSET_TABLE_+(.-L0) is read, if
270 the difference expression cannot immediately be reduced. */
272 symbolS *stmp = make_expr_symbol (exp);
274 exp->X_op = O_symbol;
275 exp->X_op_symbol = 0;
276 exp->X_add_symbol = stmp;
277 exp->X_add_number = 0;
279 return fix_new_exp (frag, where, size, exp, pcrel, r_type);
283 add = exp->X_add_symbol;
284 off = exp->X_add_number;
285 r_type = BFD_RELOC_RVA;
289 sub = exp->X_add_symbol;
290 off = exp->X_add_number;
294 sub = exp->X_op_symbol;
297 add = exp->X_add_symbol;
300 off = exp->X_add_number;
304 add = make_expr_symbol (exp);
308 return fix_new_internal (frag, where, size, add, sub, off, pcrel,
312 /* Create a fixup at the beginning of FRAG. The arguments are the same
313 as for fix_new, except that WHERE is implicitly 0. */
316 fix_at_start (fragS *frag, int size, symbolS *add_symbol,
317 offsetT offset, int pcrel, RELOC_ENUM r_type)
319 return fix_new_internal (frag, 0, size, add_symbol,
320 (symbolS *) NULL, offset, pcrel, r_type, TRUE);
323 /* Generic function to determine whether a fixup requires a relocation. */
325 generic_force_reloc (fixS *fix)
327 if (fix->fx_r_type == BFD_RELOC_VTABLE_INHERIT
328 || fix->fx_r_type == BFD_RELOC_VTABLE_ENTRY)
331 if (fix->fx_addsy == NULL)
334 return S_FORCE_RELOC (fix->fx_addsy, fix->fx_subsy == NULL);
337 /* Append a string onto another string, bumping the pointer along. */
339 append (char **charPP, char *fromP, unsigned long length)
341 /* Don't trust memcpy() of 0 chars. */
345 memcpy (*charPP, fromP, length);
349 /* This routine records the largest alignment seen for each segment.
350 If the beginning of the segment is aligned on the worst-case
351 boundary, all of the other alignments within it will work. At
352 least one object format really uses this info. */
355 record_alignment (/* Segment to which alignment pertains. */
357 /* Alignment, as a power of 2 (e.g., 1 => 2-byte
358 boundary, 2 => 4-byte boundary, etc.) */
361 if (seg == absolute_section)
364 if (align > bfd_get_section_alignment (stdoutput, seg))
365 bfd_set_section_alignment (stdoutput, seg, align);
369 get_recorded_alignment (segT seg)
371 if (seg == absolute_section)
374 return bfd_get_section_alignment (stdoutput, seg);
377 /* Reset the section indices after removing the gas created sections. */
380 renumber_sections (bfd *abfd ATTRIBUTE_UNUSED, asection *sec, void *countparg)
382 int *countp = (int *) countparg;
384 sec->index = *countp;
389 chain_frchains_together_1 (segT section, struct frchain *frchp)
391 fragS dummy, *prev_frag = &dummy;
392 fixS fix_dummy, *prev_fix = &fix_dummy;
394 for (; frchp; frchp = frchp->frch_next)
396 prev_frag->fr_next = frchp->frch_root;
397 prev_frag = frchp->frch_last;
398 gas_assert (prev_frag->fr_type != 0);
399 if (frchp->fix_root != (fixS *) NULL)
401 if (seg_info (section)->fix_root == (fixS *) NULL)
402 seg_info (section)->fix_root = frchp->fix_root;
403 prev_fix->fx_next = frchp->fix_root;
404 seg_info (section)->fix_tail = frchp->fix_tail;
405 prev_fix = frchp->fix_tail;
408 gas_assert (prev_frag != &dummy
409 && prev_frag->fr_type != 0);
410 prev_frag->fr_next = 0;
415 chain_frchains_together (bfd *abfd ATTRIBUTE_UNUSED,
417 void *xxx ATTRIBUTE_UNUSED)
419 segment_info_type *info;
421 /* BFD may have introduced its own sections without using
422 subseg_new, so it is possible that seg_info is NULL. */
423 info = seg_info (section);
424 if (info != (segment_info_type *) NULL)
425 info->frchainP->frch_last
426 = chain_frchains_together_1 (section, info->frchainP);
428 /* Now that we've chained the frags together, we must add new fixups
429 to the segment, not to the frag chain. */
434 cvt_frag_to_fill (segT sec ATTRIBUTE_UNUSED, fragS *fragP)
436 switch (fragP->fr_type)
446 HANDLE_ALIGN (fragP);
449 know (fragP->fr_next != NULL);
450 fragP->fr_offset = (fragP->fr_next->fr_address
452 - fragP->fr_fix) / fragP->fr_var;
453 if (fragP->fr_offset < 0)
455 as_bad_where (fragP->fr_file, fragP->fr_line,
456 _("attempt to .org/.space/.nops backwards? (%ld)"),
457 (long) fragP->fr_offset);
458 fragP->fr_offset = 0;
460 if (fragP->fr_type == rs_space_nop)
461 fragP->fr_type = rs_fill_nop;
463 fragP->fr_type = rs_fill;
472 valueT value = S_GET_VALUE (fragP->fr_symbol);
475 if (!S_IS_DEFINED (fragP->fr_symbol))
477 as_bad_where (fragP->fr_file, fragP->fr_line,
478 _("leb128 operand is an undefined symbol: %s"),
479 S_GET_NAME (fragP->fr_symbol));
482 size = output_leb128 (fragP->fr_literal + fragP->fr_fix, value,
485 fragP->fr_fix += size;
486 fragP->fr_type = rs_fill;
488 fragP->fr_offset = 0;
489 fragP->fr_symbol = NULL;
494 eh_frame_convert_frag (fragP);
498 dwarf2dbg_convert_frag (fragP);
501 case rs_machine_dependent:
502 md_convert_frag (stdoutput, sec, fragP);
504 gas_assert (fragP->fr_next == NULL
505 || ((offsetT) (fragP->fr_next->fr_address - fragP->fr_address)
508 /* After md_convert_frag, we make the frag into a ".space 0".
509 md_convert_frag() should set up any fixSs and constants
514 #ifndef WORKING_DOT_WORD
517 struct broken_word *lie;
519 if (fragP->fr_subtype)
521 fragP->fr_fix += md_short_jump_size;
522 for (lie = (struct broken_word *) (fragP->fr_symbol);
523 lie && lie->dispfrag == fragP;
524 lie = lie->next_broken_word)
526 fragP->fr_fix += md_long_jump_size;
534 BAD_CASE (fragP->fr_type);
538 md_frag_check (fragP);
542 struct relax_seg_info
549 relax_seg (bfd *abfd ATTRIBUTE_UNUSED, asection *sec, void *xxx)
551 segment_info_type *seginfo = seg_info (sec);
552 struct relax_seg_info *info = (struct relax_seg_info *) xxx;
554 if (seginfo && seginfo->frchainP
555 && relax_segment (seginfo->frchainP->frch_root, sec, info->pass))
560 size_seg (bfd *abfd, asection *sec, void *xxx ATTRIBUTE_UNUSED)
564 segment_info_type *seginfo;
566 valueT size, newsize;
568 subseg_change (sec, 0);
570 seginfo = seg_info (sec);
571 if (seginfo && seginfo->frchainP)
573 for (fragp = seginfo->frchainP->frch_root; fragp; fragp = fragp->fr_next)
574 cvt_frag_to_fill (sec, fragp);
575 for (fragp = seginfo->frchainP->frch_root;
577 fragp = fragp->fr_next)
578 /* Walk to last elt. */
580 size = fragp->fr_address + fragp->fr_fix;
585 flags = bfd_get_section_flags (abfd, sec);
586 if (size == 0 && bfd_get_section_size (sec) != 0 &&
587 (flags & SEC_HAS_CONTENTS) != 0)
590 if (size > 0 && ! seginfo->bss)
591 flags |= SEC_HAS_CONTENTS;
594 x = bfd_set_section_flags (abfd, sec, flags);
597 /* If permitted, allow the backend to pad out the section
598 to some alignment boundary. */
599 if (do_not_pad_sections_to_alignment)
602 newsize = md_section_align (sec, size);
603 x = bfd_set_section_size (abfd, sec, newsize);
606 /* If the size had to be rounded up, add some padding in the last
608 gas_assert (newsize >= size);
611 fragS *last = seginfo->frchainP->frch_last;
612 fragp = seginfo->frchainP->frch_root;
613 while (fragp->fr_next != last)
614 fragp = fragp->fr_next;
615 last->fr_address = size;
616 if ((newsize - size) % fragp->fr_var == 0)
617 fragp->fr_offset += (newsize - size) / fragp->fr_var;
619 /* If we hit this abort, it's likely due to subsegs_finish not
620 providing sufficient alignment on the last frag, and the
621 machine dependent code using alignment frags with fr_var
626 #ifdef tc_frob_section
627 tc_frob_section (sec);
629 #ifdef obj_frob_section
630 obj_frob_section (sec);
636 dump_section_relocs (bfd *abfd ATTRIBUTE_UNUSED, asection *sec, FILE *stream)
638 segment_info_type *seginfo = seg_info (sec);
639 fixS *fixp = seginfo->fix_root;
644 fprintf (stream, "sec %s relocs:\n", sec->name);
647 symbolS *s = fixp->fx_addsy;
649 fprintf (stream, " %08lx: type %d ", (unsigned long) fixp,
650 (int) fixp->fx_r_type);
652 fprintf (stream, "no sym\n");
655 print_symbol_value_1 (stream, s);
656 fprintf (stream, "\n");
658 fixp = fixp->fx_next;
662 #define dump_section_relocs(ABFD,SEC,STREAM) ((void) 0)
665 #ifndef EMIT_SECTION_SYMBOLS
666 #define EMIT_SECTION_SYMBOLS 1
669 /* Resolve U.A.OFFSET_SYM and U.A.SYM fields of RELOC_LIST entries,
670 and check for validity. Convert RELOC_LIST from using U.A fields
673 resolve_reloc_expr_symbols (void)
675 bfd_vma addr_mask = 1;
676 struct reloc_list *r;
678 /* Avoid a shift by the width of type. */
679 addr_mask <<= bfd_arch_bits_per_address (stdoutput) - 1;
683 for (r = reloc_list; r; r = r->next)
685 reloc_howto_type *howto = r->u.a.howto;
688 bfd_vma offset, addend;
691 resolve_symbol_value (r->u.a.offset_sym);
692 symval = symbol_get_value_expression (r->u.a.offset_sym);
696 if (symval->X_op == O_constant)
697 sym = r->u.a.offset_sym;
698 else if (symval->X_op == O_symbol)
700 sym = symval->X_add_symbol;
701 offset = symval->X_add_number;
702 symval = symbol_get_value_expression (symval->X_add_symbol);
705 || symval->X_op != O_constant
706 || (sec = S_GET_SEGMENT (sym)) == NULL
707 || !SEG_NORMAL (sec))
709 as_bad_where (r->file, r->line, _("invalid offset expression"));
713 offset += S_GET_VALUE (sym);
716 addend = r->u.a.addend;
717 if (r->u.a.sym != NULL)
719 resolve_symbol_value (r->u.a.sym);
720 symval = symbol_get_value_expression (r->u.a.sym);
721 if (symval->X_op == O_constant)
723 else if (symval->X_op == O_symbol)
725 sym = symval->X_add_symbol;
726 addend += symval->X_add_number;
727 symval = symbol_get_value_expression (symval->X_add_symbol);
729 if (symval->X_op != O_constant)
731 as_bad_where (r->file, r->line, _("invalid reloc expression"));
734 else if (sym != NULL && sec != NULL)
736 /* Convert relocs against local symbols to refer to the
737 corresponding section symbol plus offset instead. Keep
738 PC-relative relocs of the REL variety intact though to
739 prevent the offset from overflowing the relocated field,
740 unless it has enough bits to cover the whole address
742 if (S_IS_LOCAL (sym) && !symbol_section_p (sym)
744 || (howto->partial_inplace
745 && (!howto->pc_relative
746 || howto->src_mask == addr_mask))))
748 asection *symsec = S_GET_SEGMENT (sym);
749 if (!(((symsec->flags & SEC_MERGE) != 0
751 || (symsec->flags & SEC_THREAD_LOCAL) != 0))
753 addend += S_GET_VALUE (sym);
754 sym = section_symbol (symsec);
757 symbol_mark_used_in_reloc (sym);
762 if (abs_section_sym == NULL)
763 abs_section_sym = section_symbol (absolute_section);
764 sym = abs_section_sym;
768 r->u.b.s = symbol_get_bfdsym (sym);
769 r->u.b.r.sym_ptr_ptr = &r->u.b.s;
770 r->u.b.r.address = offset;
771 r->u.b.r.addend = addend;
772 r->u.b.r.howto = howto;
776 /* This pass over fixups decides whether symbols can be replaced with
780 adjust_reloc_syms (bfd *abfd ATTRIBUTE_UNUSED,
782 void *xxx ATTRIBUTE_UNUSED)
784 segment_info_type *seginfo = seg_info (sec);
790 dump_section_relocs (abfd, sec, stderr);
792 for (fixp = seginfo->fix_root; fixp; fixp = fixp->fx_next)
796 else if (fixp->fx_addsy)
802 fprintf (stderr, "\n\nadjusting fixup:\n");
806 sym = fixp->fx_addsy;
808 /* All symbols should have already been resolved at this
809 point. It is possible to see unresolved expression
810 symbols, though, since they are not in the regular symbol
812 resolve_symbol_value (sym);
814 if (fixp->fx_subsy != NULL)
815 resolve_symbol_value (fixp->fx_subsy);
817 /* If this symbol is equated to an undefined or common symbol,
818 convert the fixup to being against that symbol. */
819 while (symbol_equated_reloc_p (sym)
820 || S_IS_WEAKREFR (sym))
822 symbolS *newsym = symbol_get_value_expression (sym)->X_add_symbol;
825 fixp->fx_offset += symbol_get_value_expression (sym)->X_add_number;
826 fixp->fx_addsy = newsym;
830 if (symbol_mri_common_p (sym))
832 fixp->fx_offset += S_GET_VALUE (sym);
833 fixp->fx_addsy = symbol_get_value_expression (sym)->X_add_symbol;
837 /* If the symbol is undefined, common, weak, or global (ELF
838 shared libs), we can't replace it with the section symbol. */
839 if (S_FORCE_RELOC (fixp->fx_addsy, 1))
842 /* Is there some other (target cpu dependent) reason we can't adjust
843 this one? (E.g. relocations involving function addresses on
845 #ifdef tc_fix_adjustable
846 if (! tc_fix_adjustable (fixp))
850 /* Since we're reducing to section symbols, don't attempt to reduce
851 anything that's already using one. */
852 if (symbol_section_p (sym))
855 symsec = S_GET_SEGMENT (sym);
859 if (bfd_is_abs_section (symsec)
860 || symsec == reg_section)
862 /* The fixup_segment routine normally will not use this
863 symbol in a relocation. */
867 /* Don't try to reduce relocs which refer to non-local symbols
868 in .linkonce sections. It can lead to confusion when a
869 debugging section refers to a .linkonce section. I hope
870 this will always be correct. */
871 if (symsec != sec && ! S_IS_LOCAL (sym))
873 if ((symsec->flags & SEC_LINK_ONCE) != 0
875 /* The GNU toolchain uses an extension for ELF: a
876 section beginning with the magic string
877 .gnu.linkonce is a linkonce section. */
878 && strncmp (segment_name (symsec), ".gnu.linkonce",
879 sizeof ".gnu.linkonce" - 1) == 0))
883 /* Never adjust a reloc against local symbol in a merge section
884 with non-zero addend. */
885 if ((symsec->flags & SEC_MERGE) != 0
886 && (fixp->fx_offset != 0 || fixp->fx_subsy != NULL))
889 /* Never adjust a reloc against TLS local symbol. */
890 if ((symsec->flags & SEC_THREAD_LOCAL) != 0)
893 /* We refetch the segment when calling section_symbol, rather
894 than using symsec, because S_GET_VALUE may wind up changing
895 the section when it calls resolve_symbol_value. */
896 fixp->fx_offset += S_GET_VALUE (sym);
897 fixp->fx_addsy = section_symbol (S_GET_SEGMENT (sym));
899 fprintf (stderr, "\nadjusted fixup:\n");
904 dump_section_relocs (abfd, sec, stderr);
909 Go through all the fixS's in a segment and see which ones can be
910 handled now. (These consist of fixS where we have since discovered
911 the value of a symbol, or the address of the frag involved.)
912 For each one, call md_apply_fix to put the fix into the frag data.
913 Ones that we couldn't completely handle here will be output later
914 by emit_relocations. */
917 fixup_segment (fixS *fixP, segT this_segment)
921 segT add_symbol_segment = absolute_section;
923 if (fixP != NULL && abs_section_sym == NULL)
924 abs_section_sym = section_symbol (absolute_section);
926 /* If the linker is doing the relaxing, we must not do any fixups.
928 Well, strictly speaking that's not true -- we could do any that
929 are PC-relative and don't cross regions that could change size. */
930 if (linkrelax && TC_LINKRELAX_FIXUP (this_segment))
932 for (; fixP; fixP = fixP->fx_next)
935 if (fixP->fx_addsy == NULL)
937 /* There was no symbol required by this relocation.
938 However, BFD doesn't really handle relocations
939 without symbols well. So fake up a local symbol in
940 the absolute section. */
941 fixP->fx_addsy = abs_section_sym;
943 symbol_mark_used_in_reloc (fixP->fx_addsy);
944 if (fixP->fx_subsy != NULL)
945 symbol_mark_used_in_reloc (fixP->fx_subsy);
950 for (; fixP; fixP = fixP->fx_next)
953 fprintf (stderr, "\nprocessing fixup:\n");
957 fragP = fixP->fx_frag;
959 #ifdef TC_VALIDATE_FIX
960 TC_VALIDATE_FIX (fixP, this_segment, skip);
962 add_number = fixP->fx_offset;
964 if (fixP->fx_addsy != NULL)
965 add_symbol_segment = S_GET_SEGMENT (fixP->fx_addsy);
967 if (fixP->fx_subsy != NULL)
969 segT sub_symbol_segment;
970 resolve_symbol_value (fixP->fx_subsy);
971 sub_symbol_segment = S_GET_SEGMENT (fixP->fx_subsy);
972 if (fixP->fx_addsy != NULL
973 && sub_symbol_segment == add_symbol_segment
974 && !S_FORCE_RELOC (fixP->fx_addsy, 0)
975 && !S_FORCE_RELOC (fixP->fx_subsy, 0)
976 && !TC_FORCE_RELOCATION_SUB_SAME (fixP, add_symbol_segment))
978 add_number += S_GET_VALUE (fixP->fx_addsy);
979 add_number -= S_GET_VALUE (fixP->fx_subsy);
980 fixP->fx_offset = add_number;
981 fixP->fx_addsy = NULL;
982 fixP->fx_subsy = NULL;
984 /* See the comment below about 68k weirdness. */
988 else if (sub_symbol_segment == absolute_section
989 && !S_FORCE_RELOC (fixP->fx_subsy, 0)
990 && !TC_FORCE_RELOCATION_SUB_ABS (fixP, add_symbol_segment))
992 add_number -= S_GET_VALUE (fixP->fx_subsy);
993 fixP->fx_offset = add_number;
994 fixP->fx_subsy = NULL;
996 else if (sub_symbol_segment == this_segment
997 && !S_FORCE_RELOC (fixP->fx_subsy, 0)
998 && !TC_FORCE_RELOCATION_SUB_LOCAL (fixP, add_symbol_segment))
1000 add_number -= S_GET_VALUE (fixP->fx_subsy);
1001 fixP->fx_offset = (add_number + fixP->fx_dot_value
1002 + fixP->fx_dot_frag->fr_address);
1004 /* Make it pc-relative. If the back-end code has not
1005 selected a pc-relative reloc, cancel the adjustment
1006 we do later on all pc-relative relocs. */
1009 /* Do this for m68k even if it's already described
1010 as pc-relative. On the m68k, an operand of
1011 "pc@(foo-.-2)" should address "foo" in a
1012 pc-relative mode. */
1016 add_number += MD_PCREL_FROM_SECTION (fixP, this_segment);
1017 fixP->fx_subsy = NULL;
1020 else if (!TC_VALIDATE_FIX_SUB (fixP, add_symbol_segment))
1022 if (!md_register_arithmetic
1023 && (add_symbol_segment == reg_section
1024 || sub_symbol_segment == reg_section))
1025 as_bad_where (fixP->fx_file, fixP->fx_line,
1026 _("register value used as expression"));
1028 as_bad_where (fixP->fx_file, fixP->fx_line,
1029 _("can't resolve `%s' {%s section} - `%s' {%s section}"),
1030 fixP->fx_addsy ? S_GET_NAME (fixP->fx_addsy) : "0",
1031 segment_name (add_symbol_segment),
1032 S_GET_NAME (fixP->fx_subsy),
1033 segment_name (sub_symbol_segment));
1035 else if (sub_symbol_segment != undefined_section
1036 && ! bfd_is_com_section (sub_symbol_segment)
1037 && MD_APPLY_SYM_VALUE (fixP))
1038 add_number -= S_GET_VALUE (fixP->fx_subsy);
1043 if (add_symbol_segment == this_segment
1044 && !S_FORCE_RELOC (fixP->fx_addsy, 0)
1045 && !TC_FORCE_RELOCATION_LOCAL (fixP))
1047 /* This fixup was made when the symbol's segment was
1048 SEG_UNKNOWN, but it is now in the local segment.
1049 So we know how to do the address without relocation. */
1050 add_number += S_GET_VALUE (fixP->fx_addsy);
1051 fixP->fx_offset = add_number;
1053 add_number -= MD_PCREL_FROM_SECTION (fixP, this_segment);
1054 fixP->fx_addsy = NULL;
1057 else if (add_symbol_segment == absolute_section
1058 && !S_FORCE_RELOC (fixP->fx_addsy, 0)
1059 && !TC_FORCE_RELOCATION_ABS (fixP))
1061 add_number += S_GET_VALUE (fixP->fx_addsy);
1062 fixP->fx_offset = add_number;
1063 fixP->fx_addsy = NULL;
1065 else if (add_symbol_segment != undefined_section
1066 && ! bfd_is_com_section (add_symbol_segment)
1067 && MD_APPLY_SYM_VALUE (fixP))
1068 add_number += S_GET_VALUE (fixP->fx_addsy);
1073 add_number -= MD_PCREL_FROM_SECTION (fixP, this_segment);
1074 if (!fixP->fx_done && fixP->fx_addsy == NULL)
1076 /* There was no symbol required by this relocation.
1077 However, BFD doesn't really handle relocations
1078 without symbols well. So fake up a local symbol in
1079 the absolute section. */
1080 fixP->fx_addsy = abs_section_sym;
1085 md_apply_fix (fixP, &add_number, this_segment);
1089 if (fixP->fx_addsy == NULL)
1090 fixP->fx_addsy = abs_section_sym;
1091 symbol_mark_used_in_reloc (fixP->fx_addsy);
1092 if (fixP->fx_subsy != NULL)
1093 symbol_mark_used_in_reloc (fixP->fx_subsy);
1096 if (!fixP->fx_bit_fixP && !fixP->fx_no_overflow && fixP->fx_size != 0)
1098 if (fixP->fx_size < sizeof (valueT))
1103 mask--; /* Set all bits to one. */
1104 mask <<= fixP->fx_size * 8 - (fixP->fx_signed ? 1 : 0);
1105 if ((add_number & mask) != 0 && (add_number & mask) != mask)
1107 char buf[50], buf2[50];
1108 sprint_value (buf, fragP->fr_address + fixP->fx_where);
1109 if (add_number > 1000)
1110 sprint_value (buf2, add_number);
1112 sprintf (buf2, "%ld", (long) add_number);
1113 as_bad_where (fixP->fx_file, fixP->fx_line,
1114 ngettext ("value of %s too large for field "
1116 "value of %s too large for field "
1117 "of %d bytes at %s",
1119 buf2, fixP->fx_size, buf);
1120 } /* Generic error checking. */
1122 #ifdef WARN_SIGNED_OVERFLOW_WORD
1123 /* Warn if a .word value is too large when treated as a signed
1124 number. We already know it is not too negative. This is to
1125 catch over-large switches generated by gcc on the 68k. */
1126 if (!flag_signed_overflow_ok
1127 && fixP->fx_size == 2
1128 && add_number > 0x7fff)
1129 as_bad_where (fixP->fx_file, fixP->fx_line,
1130 _("signed .word overflow; switch may be too large; %ld at 0x%lx"),
1132 (long) (fragP->fr_address + fixP->fx_where));
1134 } /* Not a bit fix. */
1136 #ifdef TC_VALIDATE_FIX
1137 skip: ATTRIBUTE_UNUSED_LABEL
1141 fprintf (stderr, "result:\n");
1144 } /* For each fixS in this segment. */
1148 fix_segment (bfd *abfd ATTRIBUTE_UNUSED,
1150 void *xxx ATTRIBUTE_UNUSED)
1152 segment_info_type *seginfo = seg_info (sec);
1154 fixup_segment (seginfo->fix_root, sec);
1158 install_reloc (asection *sec, arelent *reloc, fragS *fragp,
1159 const char *file, unsigned int line)
1162 bfd_reloc_status_type s;
1165 if (reloc->sym_ptr_ptr != NULL
1166 && (sym = *reloc->sym_ptr_ptr) != NULL
1167 && (sym->flags & BSF_KEEP) == 0
1168 && ((sym->flags & BSF_SECTION_SYM) == 0
1169 || (EMIT_SECTION_SYMBOLS
1170 && !bfd_is_abs_section (sym->section))))
1171 as_bad_where (file, line, _("redefined symbol cannot be used on reloc"));
1173 s = bfd_install_relocation (stdoutput, reloc,
1174 fragp->fr_literal, fragp->fr_address,
1180 case bfd_reloc_overflow:
1181 as_bad_where (file, line, _("relocation overflow"));
1183 case bfd_reloc_outofrange:
1184 as_bad_where (file, line, _("relocation out of range"));
1187 as_fatal (_("%s:%u: bad return from bfd_install_relocation: %x"),
1193 get_frag_for_reloc (fragS *last_frag,
1194 const segment_info_type *seginfo,
1195 const struct reloc_list *r)
1199 for (f = last_frag; f != NULL; f = f->fr_next)
1200 if (f->fr_address <= r->u.b.r.address
1201 && r->u.b.r.address < f->fr_address + f->fr_fix)
1204 for (f = seginfo->frchainP->frch_root; f != NULL; f = f->fr_next)
1205 if (f->fr_address <= r->u.b.r.address
1206 && r->u.b.r.address < f->fr_address + f->fr_fix)
1209 for (f = seginfo->frchainP->frch_root; f != NULL; f = f->fr_next)
1210 if (f->fr_address <= r->u.b.r.address
1211 && r->u.b.r.address <= f->fr_address + f->fr_fix)
1214 as_bad_where (r->file, r->line,
1215 _("reloc not within (fixed part of) section"));
1220 write_relocs (bfd *abfd, asection *sec, void *xxx ATTRIBUTE_UNUSED)
1222 segment_info_type *seginfo = seg_info (sec);
1224 struct reloc_list *my_reloc_list, **rp, *r;
1229 /* If seginfo is NULL, we did not create this section; don't do
1230 anything with it. */
1231 if (seginfo == NULL)
1235 for (fixp = seginfo->fix_root; fixp; fixp = fixp->fx_next)
1239 #ifdef RELOC_EXPANSION_POSSIBLE
1240 n *= MAX_RELOC_EXPANSION;
1243 /* Extract relocs for this section from reloc_list. */
1245 my_reloc_list = NULL;
1246 while ((r = *rp) != NULL)
1248 if (r->u.b.sec == sec)
1251 r->next = my_reloc_list;
1259 relocs = XCNEWVEC (arelent *, n);
1264 for (fixp = seginfo->fix_root; fixp != (fixS *) NULL; fixp = fixp->fx_next)
1269 #ifndef RELOC_EXPANSION_POSSIBLE
1278 fx_size = fixp->fx_size;
1279 slack = TC_FX_SIZE_SLACK (fixp);
1281 fx_size = fx_size > slack ? fx_size - slack : 0;
1282 loc = fixp->fx_where + fx_size;
1283 if (slack >= 0 && loc > fixp->fx_frag->fr_fix)
1284 as_bad_where (fixp->fx_file, fixp->fx_line,
1285 _("internal error: fixup not contained within frag"));
1287 #ifndef RELOC_EXPANSION_POSSIBLE
1288 *reloc = tc_gen_reloc (sec, fixp);
1290 reloc = tc_gen_reloc (sec, fixp);
1295 while (r != NULL && r->u.b.r.address < (*reloc)->address)
1297 fragS *f = get_frag_for_reloc (last_frag, seginfo, r);
1301 relocs[n++] = &r->u.b.r;
1302 install_reloc (sec, &r->u.b.r, f, r->file, r->line);
1306 relocs[n++] = *reloc;
1307 install_reloc (sec, *reloc, fixp->fx_frag,
1308 fixp->fx_file, fixp->fx_line);
1309 #ifndef RELOC_EXPANSION_POSSIBLE
1319 fragS *f = get_frag_for_reloc (last_frag, seginfo, r);
1323 relocs[n++] = &r->u.b.r;
1324 install_reloc (sec, &r->u.b.r, f, r->file, r->line);
1331 unsigned int k, j, nsyms;
1333 sympp = bfd_get_outsymbols (stdoutput);
1334 nsyms = bfd_get_symcount (stdoutput);
1335 for (k = 0; k < n; k++)
1336 if (((*relocs[k]->sym_ptr_ptr)->flags & BSF_SECTION_SYM) == 0)
1338 for (j = 0; j < nsyms; j++)
1339 if (sympp[j] == *relocs[k]->sym_ptr_ptr)
1349 flagword flags = bfd_get_section_flags (abfd, sec);
1351 bfd_set_section_flags (abfd, sec, flags);
1352 bfd_set_reloc (stdoutput, sec, relocs, n);
1355 #ifdef SET_SECTION_RELOCS
1356 SET_SECTION_RELOCS (sec, relocs, n);
1363 fprintf (stderr, "relocs for sec %s\n", sec->name);
1364 for (k = 0; k < n; k++)
1366 arelent *rel = relocs[k];
1367 asymbol *s = *rel->sym_ptr_ptr;
1368 fprintf (stderr, " reloc %2d @%p off %4lx : sym %-10s addend %lx\n",
1369 k, rel, (unsigned long)rel->address, s->name,
1370 (unsigned long)rel->addend);
1377 compress_frag (struct z_stream_s *strm, const char *contents, int in_size,
1378 fragS **last_newf, struct obstack *ob)
1381 int total_out_size = 0;
1382 fragS *f = *last_newf;
1386 /* Call the compression routine repeatedly until it has finished
1387 processing the frag. */
1390 /* Reserve all the space available in the current chunk.
1391 If none is available, start a new frag. */
1392 avail_out = obstack_room (ob);
1395 obstack_finish (ob);
1396 f = frag_alloc (ob);
1397 f->fr_type = rs_fill;
1398 (*last_newf)->fr_next = f;
1400 avail_out = obstack_room (ob);
1403 as_fatal (_("can't extend frag"));
1404 next_out = obstack_next_free (ob);
1405 obstack_blank_fast (ob, avail_out);
1406 out_size = compress_data (strm, &contents, &in_size,
1407 &next_out, &avail_out);
1411 f->fr_fix += out_size;
1412 total_out_size += out_size;
1414 /* Return unused space. */
1416 obstack_blank_fast (ob, -avail_out);
1419 return total_out_size;
1423 compress_debug (bfd *abfd, asection *sec, void *xxx ATTRIBUTE_UNUSED)
1425 segment_info_type *seginfo = seg_info (sec);
1429 struct obstack *ob = &seginfo->frchainP->frch_obstack;
1430 bfd_size_type uncompressed_size = (bfd_size_type) sec->size;
1431 bfd_size_type compressed_size;
1432 const char *section_name;
1433 char *compressed_name;
1435 struct z_stream_s *strm;
1437 flagword flags = bfd_get_section_flags (abfd, sec);
1438 unsigned int header_size, compression_header_size;
1442 || (flags & (SEC_ALLOC | SEC_HAS_CONTENTS)) == SEC_ALLOC)
1445 section_name = bfd_get_section_name (stdoutput, sec);
1446 if (strncmp (section_name, ".debug_", 7) != 0)
1449 strm = compress_init ();
1453 if (flag_compress_debug == COMPRESS_DEBUG_GABI_ZLIB)
1455 compression_header_size
1456 = bfd_get_compression_header_size (stdoutput, NULL);
1457 header_size = compression_header_size;
1461 compression_header_size = 0;
1465 /* Create a new frag to contain the compression header. */
1466 first_newf = frag_alloc (ob);
1467 if (obstack_room (ob) < header_size)
1468 first_newf = frag_alloc (ob);
1469 if (obstack_room (ob) < header_size)
1470 as_fatal (ngettext ("can't extend frag %lu char",
1471 "can't extend frag %lu chars",
1472 (unsigned long) header_size),
1473 (unsigned long) header_size);
1474 last_newf = first_newf;
1475 obstack_blank_fast (ob, header_size);
1476 last_newf->fr_type = rs_fill;
1477 last_newf->fr_fix = header_size;
1478 header = last_newf->fr_literal;
1479 compressed_size = header_size;
1481 /* Stream the frags through the compression engine, adding new frags
1482 as necessary to accommodate the compressed output. */
1483 for (f = seginfo->frchainP->frch_root;
1492 gas_assert (f->fr_type == rs_fill);
1495 out_size = compress_frag (strm, f->fr_literal, f->fr_fix,
1499 compressed_size += out_size;
1501 fill_literal = f->fr_literal + f->fr_fix;
1502 fill_size = f->fr_var;
1503 count = f->fr_offset;
1504 gas_assert (count >= 0);
1505 if (fill_size && count)
1509 out_size = compress_frag (strm, fill_literal, (int) fill_size,
1513 compressed_size += out_size;
1518 /* Flush the compression state. */
1525 /* Reserve all the space available in the current chunk.
1526 If none is available, start a new frag. */
1527 avail_out = obstack_room (ob);
1532 obstack_finish (ob);
1533 newf = frag_alloc (ob);
1534 newf->fr_type = rs_fill;
1535 last_newf->fr_next = newf;
1537 avail_out = obstack_room (ob);
1540 as_fatal (_("can't extend frag"));
1541 next_out = obstack_next_free (ob);
1542 obstack_blank_fast (ob, avail_out);
1543 x = compress_finish (strm, &next_out, &avail_out, &out_size);
1547 last_newf->fr_fix += out_size;
1548 compressed_size += out_size;
1550 /* Return unused space. */
1552 obstack_blank_fast (ob, -avail_out);
1558 /* PR binutils/18087: If compression didn't make the section smaller,
1559 just keep it uncompressed. */
1560 if (compressed_size >= uncompressed_size)
1563 /* Replace the uncompressed frag list with the compressed frag list. */
1564 seginfo->frchainP->frch_root = first_newf;
1565 seginfo->frchainP->frch_last = last_newf;
1567 /* Update the section size and its name. */
1568 bfd_update_compression_header (abfd, (bfd_byte *) header, sec);
1569 x = bfd_set_section_size (abfd, sec, compressed_size);
1571 if (!compression_header_size)
1573 compressed_name = concat (".z", section_name + 1, (char *) NULL);
1574 bfd_section_name (stdoutput, sec) = compressed_name;
1578 #ifndef md_generate_nops
1579 /* Genenerate COUNT bytes of no-op instructions to WHERE. A target
1580 backend must override this with proper no-op instructions. */
1583 md_generate_nops (fragS *f ATTRIBUTE_UNUSED,
1584 char *where ATTRIBUTE_UNUSED,
1585 offsetT count ATTRIBUTE_UNUSED,
1586 int control ATTRIBUTE_UNUSED)
1588 as_bad (_("unimplemented .nops directive"));
1593 write_contents (bfd *abfd ATTRIBUTE_UNUSED,
1595 void *xxx ATTRIBUTE_UNUSED)
1597 segment_info_type *seginfo = seg_info (sec);
1598 addressT offset = 0;
1601 /* Write out the frags. */
1603 || !(bfd_get_section_flags (abfd, sec) & SEC_HAS_CONTENTS))
1606 for (f = seginfo->frchainP->frch_root;
1615 gas_assert (f->fr_type == rs_fill || f->fr_type == rs_fill_nop);
1618 x = bfd_set_section_contents (stdoutput, sec,
1619 f->fr_literal, (file_ptr) offset,
1620 (bfd_size_type) f->fr_fix);
1622 as_fatal (ngettext ("can't write %ld byte "
1623 "to section %s of %s: '%s'",
1624 "can't write %ld bytes "
1625 "to section %s of %s: '%s'",
1628 sec->name, stdoutput->filename,
1629 bfd_errmsg (bfd_get_error ()));
1630 offset += f->fr_fix;
1633 fill_size = f->fr_var;
1634 count = f->fr_offset;
1635 fill_literal = f->fr_literal + f->fr_fix;
1637 if (f->fr_type == rs_fill_nop)
1639 gas_assert (count >= 0 && fill_size == 1);
1642 char *buf = xmalloc (count);
1643 md_generate_nops (f, buf, count, *fill_literal);
1644 x = bfd_set_section_contents
1645 (stdoutput, sec, buf, (file_ptr) offset,
1646 (bfd_size_type) count);
1648 as_fatal (ngettext ("can't fill %ld byte "
1649 "in section %s of %s: '%s'",
1650 "can't fill %ld bytes "
1651 "in section %s of %s: '%s'",
1652 (long) count), (long) count,
1653 sec->name, stdoutput->filename,
1654 bfd_errmsg (bfd_get_error ()));
1661 gas_assert (count >= 0);
1662 if (fill_size && count)
1665 if (fill_size > sizeof (buf))
1667 /* Do it the old way. Can this ever happen? */
1670 x = bfd_set_section_contents (stdoutput, sec,
1673 (bfd_size_type) fill_size);
1675 as_fatal (ngettext ("can't fill %ld byte "
1676 "in section %s of %s: '%s'",
1677 "can't fill %ld bytes "
1678 "in section %s of %s: '%s'",
1681 sec->name, stdoutput->filename,
1682 bfd_errmsg (bfd_get_error ()));
1683 offset += fill_size;
1688 /* Build a buffer full of fill objects and output it as
1689 often as necessary. This saves on the overhead of
1690 potentially lots of bfd_set_section_contents calls. */
1694 n_per_buf = sizeof (buf);
1695 memset (buf, *fill_literal, n_per_buf);
1700 n_per_buf = sizeof (buf) / fill_size;
1701 for (i = n_per_buf, bufp = buf; i; i--, bufp += fill_size)
1702 memcpy (bufp, fill_literal, fill_size);
1704 for (; count > 0; count -= n_per_buf)
1706 n_per_buf = n_per_buf > count ? count : n_per_buf;
1707 x = bfd_set_section_contents
1708 (stdoutput, sec, buf, (file_ptr) offset,
1709 (bfd_size_type) n_per_buf * fill_size);
1711 as_fatal (ngettext ("can't fill %ld byte "
1712 "in section %s of %s: '%s'",
1713 "can't fill %ld bytes "
1714 "in section %s of %s: '%s'",
1715 (long) (n_per_buf * fill_size)),
1716 (long) (n_per_buf * fill_size),
1717 sec->name, stdoutput->filename,
1718 bfd_errmsg (bfd_get_error ()));
1719 offset += n_per_buf * fill_size;
1727 merge_data_into_text (void)
1729 seg_info (text_section)->frchainP->frch_last->fr_next =
1730 seg_info (data_section)->frchainP->frch_root;
1731 seg_info (text_section)->frchainP->frch_last =
1732 seg_info (data_section)->frchainP->frch_last;
1733 seg_info (data_section)->frchainP = 0;
1744 /* Count symbols. We can't rely on a count made by the loop in
1745 write_object_file, because *_frob_file may add a new symbol or
1748 for (symp = symbol_rootP; symp; symp = symbol_next (symp))
1754 bfd_size_type amt = (bfd_size_type) nsyms * sizeof (asymbol *);
1756 asympp = (asymbol **) bfd_alloc (stdoutput, amt);
1757 symp = symbol_rootP;
1758 for (i = 0; i < nsyms; i++, symp = symbol_next (symp))
1760 asympp[i] = symbol_get_bfdsym (symp);
1761 if (asympp[i]->flags != BSF_SECTION_SYM
1762 || !(bfd_is_const_section (asympp[i]->section)
1763 && asympp[i]->section->symbol == asympp[i]))
1764 asympp[i]->flags |= BSF_KEEP;
1765 symbol_mark_written (symp);
1770 result = bfd_set_symtab (stdoutput, asympp, nsyms);
1771 gas_assert (result);
1772 symbol_table_frozen = 1;
1775 /* Finish the subsegments. After every sub-segment, we fake an
1776 ".align ...". This conforms to BSD4.2 brain-damage. We then fake
1777 ".fill 0" because that is the kind of frag that requires least
1778 thought. ".align" frags like to have a following frag since that
1779 makes calculating their intended length trivial. */
1781 #ifndef SUB_SEGMENT_ALIGN
1783 /* The last subsegment gets an alignment corresponding to the alignment
1784 of the section. This allows proper nop-filling at the end of
1785 code-bearing sections. */
1786 #define SUB_SEGMENT_ALIGN(SEG, FRCHAIN) \
1787 (!(FRCHAIN)->frch_next && subseg_text_p (SEG) \
1788 && !do_not_pad_sections_to_alignment \
1789 ? get_recorded_alignment (SEG) \
1792 #define SUB_SEGMENT_ALIGN(SEG, FRCHAIN) 0
1797 subsegs_finish_section (asection *s)
1799 struct frchain *frchainP;
1800 segment_info_type *seginfo = seg_info (s);
1804 for (frchainP = seginfo->frchainP;
1806 frchainP = frchainP->frch_next)
1810 subseg_set (s, frchainP->frch_subseg);
1812 /* This now gets called even if we had errors. In that case,
1813 any alignment is meaningless, and, moreover, will look weird
1814 if we are generating a listing. */
1816 do_not_pad_sections_to_alignment = 1;
1818 alignment = SUB_SEGMENT_ALIGN (now_seg, frchainP);
1819 if ((bfd_get_section_flags (now_seg->owner, now_seg) & SEC_MERGE)
1820 && now_seg->entsize)
1822 unsigned int entsize = now_seg->entsize;
1825 while ((entsize & 1) == 0)
1831 if (entalign > alignment)
1832 alignment = entalign;
1835 if (subseg_text_p (now_seg))
1836 frag_align_code (alignment, 0);
1838 frag_align (alignment, 0, 0);
1840 /* frag_align will have left a new frag.
1841 Use this last frag for an empty ".fill".
1843 For this segment ...
1844 Create a last frag. Do not leave a "being filled in frag". */
1845 frag_wane (frag_now);
1846 frag_now->fr_fix = 0;
1847 know (frag_now->fr_next == NULL);
1852 subsegs_finish (void)
1856 for (s = stdoutput->sections; s; s = s->next)
1857 subsegs_finish_section (s);
1862 create_obj_attrs_section (void)
1869 size = bfd_elf_obj_attr_size (stdoutput);
1873 name = get_elf_backend_data (stdoutput)->obj_attrs_section;
1875 name = ".gnu.attributes";
1876 s = subseg_new (name, 0);
1877 elf_section_type (s)
1878 = get_elf_backend_data (stdoutput)->obj_attrs_section_type;
1879 bfd_set_section_flags (stdoutput, s, SEC_READONLY | SEC_DATA);
1881 p = frag_more (size);
1882 bfd_elf_set_obj_attr_contents (stdoutput, (bfd_byte *)p, size);
1884 subsegs_finish_section (s);
1885 relax_segment (seg_info (s)->frchainP->frch_root, s, 0);
1886 size_seg (stdoutput, s, NULL);
1889 #include "struc-symbol.h"
1891 /* Create a relocation against an entry in a GNU Build attribute section. */
1894 create_note_reloc (segT sec,
1896 bfd_size_type offset,
1901 struct reloc_list * reloc;
1903 reloc = XNEW (struct reloc_list);
1905 /* We create a .b type reloc as resolve_reloc_expr_symbols() has already been called. */
1906 reloc->u.b.sec = sec;
1907 reloc->u.b.s = sym->bsym;
1908 reloc->u.b.r.sym_ptr_ptr = & reloc->u.b.s;
1909 reloc->u.b.r.address = offset;
1910 reloc->u.b.r.addend = addend;
1911 reloc->u.b.r.howto = bfd_reloc_type_lookup (stdoutput, reloc_type);
1913 if (reloc->u.b.r.howto == NULL)
1915 as_bad (_("unable to create reloc for build note"));
1919 reloc->file = N_("<gnu build note>");
1922 reloc->next = reloc_list;
1925 /* For REL relocs, store the addend in the section. */
1926 if (! sec->use_rela_p
1927 /* The SH target is a special case that uses RELA relocs
1928 but still stores the addend in the word being relocated. */
1929 || strstr (bfd_get_target (stdoutput), "-sh") != NULL)
1931 if (target_big_endian)
1933 if (bfd_arch_bits_per_address (stdoutput) <= 32)
1934 note[offset + 3] = addend;
1936 note[offset + 7] = addend;
1939 note[offset] = addend;
1944 maybe_generate_build_notes (void)
1951 offsetT desc2_offset;
1955 if (! flag_generate_build_notes
1956 || bfd_get_section_by_name (stdoutput,
1957 GNU_BUILD_ATTRS_SECTION_NAME) != NULL)
1960 /* Create a GNU Build Attribute section. */
1961 sec = subseg_new (GNU_BUILD_ATTRS_SECTION_NAME, FALSE);
1962 elf_section_type (sec) = SHT_NOTE;
1963 bfd_set_section_flags (stdoutput, sec,
1964 SEC_READONLY | SEC_HAS_CONTENTS | SEC_DATA);
1965 bfd_set_section_alignment (stdoutput, sec, 2);
1967 /* Work out the size of the notes that we will create,
1968 and the relocation we should use. */
1969 if (bfd_arch_bits_per_address (stdoutput) <= 32)
1972 desc_size = 8; /* Two 4-byte offsets. */
1975 /* FIXME: The BFD backend for the CRX target does not support the
1976 BFD_RELOC_32, even though it really should. Likewise for the
1977 CR16 target. So we have special case code here... */
1978 if (strstr (bfd_get_target (stdoutput), "-crx") != NULL)
1979 desc_reloc = BFD_RELOC_CRX_NUM32;
1980 else if (strstr (bfd_get_target (stdoutput), "-cr16") != NULL)
1981 desc_reloc = BFD_RELOC_CR16_NUM32;
1983 desc_reloc = BFD_RELOC_32;
1988 desc_size = 16; /* Two 8-byte offsets. */
1990 /* FIXME: The BFD backend for the IA64 target does not support the
1991 BFD_RELOC_64, even though it really should. The HPPA backend
1992 has a similar issue, although it does not support BFD_RELOCs at
1993 all! So we have special case code to handle these targets. */
1994 if (strstr (bfd_get_target (stdoutput), "-ia64") != NULL)
1995 desc_reloc = target_big_endian ? BFD_RELOC_IA64_DIR32MSB : BFD_RELOC_IA64_DIR32LSB;
1996 else if (strstr (bfd_get_target (stdoutput), "-hppa") != NULL)
1997 desc_reloc = 80; /* R_PARISC_DIR64. */
1999 desc_reloc = BFD_RELOC_64;
2002 /* We have to create a note for *each* code section.
2003 Linker garbage collection might discard some. */
2007 for (sym = symbol_rootP; sym != NULL; sym = sym->sy_next)
2008 if (sym->bsym != NULL
2009 && sym->bsym->flags & BSF_SECTION_SYM
2010 && sym->bsym->section != NULL
2011 /* Skip linkonce sections - we cannot use these section symbols as they may disappear. */
2012 && (sym->bsym->section->flags & (SEC_CODE | SEC_LINK_ONCE)) == SEC_CODE
2013 /* Not all linkonce sections are flagged... */
2014 && strncmp (S_GET_NAME (sym), ".gnu.linkonce", sizeof ".gnu.linkonce" - 1) != 0)
2016 /* Create a version note. */
2018 note = frag_more (note_size);
2019 memset (note, 0, note_size);
2021 if (target_big_endian)
2023 note[3] = 8; /* strlen (name) + 1. */
2024 note[7] = desc_size; /* Two 8-byte offsets. */
2025 note[10] = NT_GNU_BUILD_ATTRIBUTE_OPEN >> 8;
2026 note[11] = NT_GNU_BUILD_ATTRIBUTE_OPEN & 0xff;
2030 note[0] = 8; /* strlen (name) + 1. */
2031 note[4] = desc_size; /* Two 8-byte offsets. */
2032 note[8] = NT_GNU_BUILD_ATTRIBUTE_OPEN & 0xff;
2033 note[9] = NT_GNU_BUILD_ATTRIBUTE_OPEN >> 8;
2036 /* The a1 version number indicates that this note was
2037 generated by the assembler and not the gcc annobin plugin. */
2038 memcpy (note + 12, "GA$
\ 13a1", 8);
2040 /* Create a relocation to install the start address of the note... */
2041 create_note_reloc (sec, sym, total_size + 20, desc_reloc, 0, note);
2043 /* ...and another one to install the end address. */
2044 create_note_reloc (sec, sym, total_size + desc2_offset, desc_reloc,
2045 bfd_get_section_size (sym->bsym->section),
2048 total_size += note_size;
2049 /* FIXME: Maybe add a note recording the assembler command line and version ? */
2052 /* Install the note(s) into the section. */
2054 bfd_set_section_contents (stdoutput, sec, (bfd_byte *) note, 0, total_size);
2055 subsegs_finish_section (sec);
2056 relax_segment (seg_info (sec)->frchainP->frch_root, sec, 0);
2057 size_seg (stdoutput, sec, NULL);
2059 #endif /* OBJ_ELF */
2061 /* Write the object file. */
2064 write_object_file (void)
2066 struct relax_seg_info rsi;
2067 #ifndef WORKING_DOT_WORD
2068 fragS *fragP; /* Track along all frags. */
2073 #ifdef md_pre_output_hook
2077 #ifdef md_pre_relax_hook
2081 /* From now on, we don't care about sub-segments. Build one frag chain
2082 for each segment. Linked through fr_next. */
2084 /* Remove the sections created by gas for its own purposes. */
2088 bfd_section_list_remove (stdoutput, reg_section);
2089 bfd_section_list_remove (stdoutput, expr_section);
2090 stdoutput->section_count -= 2;
2092 bfd_map_over_sections (stdoutput, renumber_sections, &i);
2095 bfd_map_over_sections (stdoutput, chain_frchains_together, (char *) 0);
2097 /* We have two segments. If user gave -R flag, then we must put the
2098 data frags into the text segment. Do this before relaxing so
2099 we know to take advantage of -R and make shorter addresses. */
2100 if (flag_readonly_data_in_text)
2102 merge_data_into_text ();
2108 #ifndef WORKING_DOT_WORD
2109 /* We need to reset the markers in the broken word list and
2110 associated frags between calls to relax_segment (via
2111 relax_seg). Since the broken word list is global, we do it
2112 once per round, rather than locally in relax_segment for each
2114 struct broken_word *brokp;
2116 for (brokp = broken_words;
2117 brokp != (struct broken_word *) NULL;
2118 brokp = brokp->next_broken_word)
2122 if (brokp->dispfrag != (fragS *) NULL
2123 && brokp->dispfrag->fr_type == rs_broken_word)
2124 brokp->dispfrag->fr_subtype = 0;
2129 bfd_map_over_sections (stdoutput, relax_seg, &rsi);
2135 /* Note - Most ports will use the default value of
2136 TC_FINALIZE_SYMS_BEFORE_SIZE_SEG, which 1. This will force
2137 local symbols to be resolved, removing their frag information.
2138 Some ports however, will not have finished relaxing all of
2139 their frags and will still need the local symbol frag
2140 information. These ports can set
2141 TC_FINALIZE_SYMS_BEFORE_SIZE_SEG to 0. */
2142 finalize_syms = TC_FINALIZE_SYMS_BEFORE_SIZE_SEG;
2144 bfd_map_over_sections (stdoutput, size_seg, (char *) 0);
2146 /* Relaxation has completed. Freeze all syms. */
2149 dwarf2dbg_final_check ();
2151 #ifdef md_post_relax_hook
2157 create_obj_attrs_section ();
2160 #ifndef WORKING_DOT_WORD
2162 struct broken_word *lie;
2163 struct broken_word **prevP;
2165 prevP = &broken_words;
2166 for (lie = broken_words; lie; lie = lie->next_broken_word)
2171 subseg_change (lie->seg, lie->subseg);
2172 exp.X_op = O_subtract;
2173 exp.X_add_symbol = lie->add;
2174 exp.X_op_symbol = lie->sub;
2175 exp.X_add_number = lie->addnum;
2176 #ifdef TC_CONS_FIX_NEW
2177 TC_CONS_FIX_NEW (lie->frag,
2178 lie->word_goes_here - lie->frag->fr_literal,
2179 2, &exp, TC_PARSE_CONS_RETURN_NONE);
2181 fix_new_exp (lie->frag,
2182 lie->word_goes_here - lie->frag->fr_literal,
2183 2, &exp, 0, BFD_RELOC_16);
2185 *prevP = lie->next_broken_word;
2188 prevP = &(lie->next_broken_word);
2190 for (lie = broken_words; lie;)
2192 struct broken_word *untruth;
2194 addressT table_addr;
2195 addressT from_addr, to_addr;
2198 subseg_change (lie->seg, lie->subseg);
2199 fragP = lie->dispfrag;
2201 /* Find out how many broken_words go here. */
2204 untruth && untruth->dispfrag == fragP;
2205 untruth = untruth->next_broken_word)
2206 if (untruth->added == 1)
2209 table_ptr = lie->dispfrag->fr_opcode;
2210 table_addr = (lie->dispfrag->fr_address
2211 + (table_ptr - lie->dispfrag->fr_literal));
2212 /* Create the jump around the long jumps. This is a short
2213 jump from table_ptr+0 to table_ptr+n*long_jump_size. */
2214 from_addr = table_addr;
2215 to_addr = table_addr + md_short_jump_size + n * md_long_jump_size;
2216 md_create_short_jump (table_ptr, from_addr, to_addr, lie->dispfrag,
2218 table_ptr += md_short_jump_size;
2219 table_addr += md_short_jump_size;
2222 lie && lie->dispfrag == fragP;
2223 m++, lie = lie->next_broken_word)
2225 if (lie->added == 2)
2227 /* Patch the jump table. */
2228 for (untruth = (struct broken_word *) (fragP->fr_symbol);
2229 untruth && untruth->dispfrag == fragP;
2230 untruth = untruth->next_broken_word)
2232 if (untruth->use_jump == lie)
2234 /* This is the offset from ??? to table_ptr+0.
2235 The target is the same for all users of this
2236 md_long_jump, but the "sub" bases (and hence the
2237 offsets) may be different. */
2238 addressT to_word = table_addr - S_GET_VALUE (untruth->sub);
2239 #ifdef TC_CHECK_ADJUSTED_BROKEN_DOT_WORD
2240 TC_CHECK_ADJUSTED_BROKEN_DOT_WORD (to_word, untruth);
2242 md_number_to_chars (untruth->word_goes_here, to_word, 2);
2246 /* Install the long jump. */
2247 /* This is a long jump from table_ptr+0 to the final target. */
2248 from_addr = table_addr;
2249 to_addr = S_GET_VALUE (lie->add) + lie->addnum;
2250 md_create_long_jump (table_ptr, from_addr, to_addr, lie->dispfrag,
2252 table_ptr += md_long_jump_size;
2253 table_addr += md_long_jump_size;
2257 #endif /* not WORKING_DOT_WORD */
2259 /* Resolve symbol values. This needs to be done before processing
2265 for (symp = symbol_rootP; symp; symp = symbol_next (symp))
2266 resolve_symbol_value (symp);
2268 resolve_local_symbol_values ();
2269 resolve_reloc_expr_symbols ();
2273 maybe_generate_build_notes ();
2278 #ifdef tc_frob_file_before_adjust
2279 tc_frob_file_before_adjust ();
2281 #ifdef obj_frob_file_before_adjust
2282 obj_frob_file_before_adjust ();
2285 bfd_map_over_sections (stdoutput, adjust_reloc_syms, (char *) 0);
2287 #ifdef tc_frob_file_before_fix
2288 tc_frob_file_before_fix ();
2290 #ifdef obj_frob_file_before_fix
2291 obj_frob_file_before_fix ();
2294 bfd_map_over_sections (stdoutput, fix_segment, (char *) 0);
2296 /* Set up symbol table, and write it out. */
2300 bfd_boolean skip_next_symbol = FALSE;
2302 for (symp = symbol_rootP; symp; symp = symbol_next (symp))
2307 if (skip_next_symbol)
2309 /* Don't do anything besides moving the value of the
2310 symbol from the GAS value-field to the BFD value-field. */
2311 symbol_get_bfdsym (symp)->value = S_GET_VALUE (symp);
2312 skip_next_symbol = FALSE;
2316 if (symbol_mri_common_p (symp))
2318 if (S_IS_EXTERNAL (symp))
2319 as_bad (_("%s: global symbols not supported in common sections"),
2321 symbol_remove (symp, &symbol_rootP, &symbol_lastP);
2325 name = S_GET_NAME (symp);
2329 decode_local_label_name ((char *) S_GET_NAME (symp));
2330 /* They only differ if `name' is a fb or dollar local
2332 if (name2 != name && ! S_IS_DEFINED (symp))
2333 as_bad (_("local label `%s' is not defined"), name2);
2336 /* Do it again, because adjust_reloc_syms might introduce
2337 more symbols. They'll probably only be section symbols,
2338 but they'll still need to have the values computed. */
2339 resolve_symbol_value (symp);
2341 /* Skip symbols which were equated to undefined or common
2343 if (symbol_equated_reloc_p (symp)
2344 || S_IS_WEAKREFR (symp))
2346 const char *sname = S_GET_NAME (symp);
2348 if (S_IS_COMMON (symp)
2349 && !TC_FAKE_LABEL (sname)
2350 && !S_IS_WEAKREFR (symp))
2352 expressionS *e = symbol_get_value_expression (symp);
2354 as_bad (_("`%s' can't be equated to common symbol `%s'"),
2355 sname, S_GET_NAME (e->X_add_symbol));
2357 if (S_GET_SEGMENT (symp) == reg_section)
2359 /* Report error only if we know the symbol name. */
2360 if (S_GET_NAME (symp) != reg_section->name)
2361 as_bad (_("can't make global register symbol `%s'"),
2364 symbol_remove (symp, &symbol_rootP, &symbol_lastP);
2368 #ifdef obj_frob_symbol
2369 obj_frob_symbol (symp, punt);
2371 #ifdef tc_frob_symbol
2372 if (! punt || symbol_used_in_reloc_p (symp))
2373 tc_frob_symbol (symp, punt);
2376 /* If we don't want to keep this symbol, splice it out of
2377 the chain now. If EMIT_SECTION_SYMBOLS is 0, we never
2378 want section symbols. Otherwise, we skip local symbols
2379 and symbols that the frob_symbol macros told us to punt,
2380 but we keep such symbols if they are used in relocs. */
2381 if (symp == abs_section_sym
2382 || (! EMIT_SECTION_SYMBOLS
2383 && symbol_section_p (symp))
2384 /* Note that S_IS_EXTERNAL and S_IS_LOCAL are not always
2385 opposites. Sometimes the former checks flags and the
2386 latter examines the name... */
2387 || (!S_IS_EXTERNAL (symp)
2388 && (punt || S_IS_LOCAL (symp) ||
2389 (S_IS_WEAKREFD (symp) && ! symbol_used_p (symp)))
2390 && ! symbol_used_in_reloc_p (symp)))
2392 symbol_remove (symp, &symbol_rootP, &symbol_lastP);
2394 /* After symbol_remove, symbol_next(symp) still returns
2395 the one that came after it in the chain. So we don't
2396 need to do any extra cleanup work here. */
2400 /* Make sure we really got a value for the symbol. */
2401 if (! symbol_resolved_p (symp))
2403 as_bad (_("can't resolve value for symbol `%s'"),
2405 symbol_mark_resolved (symp);
2408 /* Set the value into the BFD symbol. Up til now the value
2409 has only been kept in the gas symbolS struct. */
2410 symbol_get_bfdsym (symp)->value = S_GET_VALUE (symp);
2412 /* A warning construct is a warning symbol followed by the
2413 symbol warned about. Don't let anything object-format or
2414 target-specific muck with it; it's ready for output. */
2415 if (symbol_get_bfdsym (symp)->flags & BSF_WARNING)
2416 skip_next_symbol = TRUE;
2422 /* Now do any format-specific adjustments to the symbol table, such
2423 as adding file symbols. */
2424 #ifdef tc_adjust_symtab
2425 tc_adjust_symtab ();
2427 #ifdef obj_adjust_symtab
2428 obj_adjust_symtab ();
2431 /* Stop if there is an error. */
2435 /* Now that all the sizes are known, and contents correct, we can
2436 start writing to the file. */
2439 /* If *_frob_file changes the symbol value at this point, it is
2440 responsible for moving the changed value into symp->bsym->value
2441 as well. Hopefully all symbol value changing can be done in
2446 #ifdef obj_frob_file
2449 #ifdef obj_coff_generate_pdata
2450 obj_coff_generate_pdata ();
2453 bfd_map_over_sections (stdoutput, write_relocs, (char *) 0);
2455 #ifdef tc_frob_file_after_relocs
2456 tc_frob_file_after_relocs ();
2458 #ifdef obj_frob_file_after_relocs
2459 obj_frob_file_after_relocs ();
2462 #if defined OBJ_ELF || defined OBJ_MAYBE_ELF
2463 if (IS_ELF && flag_use_elf_stt_common)
2464 stdoutput->flags |= BFD_CONVERT_ELF_COMMON | BFD_USE_ELF_STT_COMMON;
2467 /* Once all relocations have been written, we can compress the
2468 contents of the debug sections. This needs to be done before
2469 we start writing any sections, because it will affect the file
2470 layout, which is fixed once we start writing contents. */
2471 if (flag_compress_debug)
2473 if (flag_compress_debug == COMPRESS_DEBUG_GABI_ZLIB)
2474 stdoutput->flags |= BFD_COMPRESS | BFD_COMPRESS_GABI;
2476 stdoutput->flags |= BFD_COMPRESS;
2477 bfd_map_over_sections (stdoutput, compress_debug, (char *) 0);
2480 bfd_map_over_sections (stdoutput, write_contents, (char *) 0);
2483 #ifdef TC_GENERIC_RELAX_TABLE
2484 /* Relax a fragment by scanning TC_GENERIC_RELAX_TABLE. */
2487 relax_frag (segT segment, fragS *fragP, long stretch)
2489 const relax_typeS *this_type;
2490 const relax_typeS *start_type;
2491 relax_substateT next_state;
2492 relax_substateT this_state;
2498 const relax_typeS *table;
2500 target = fragP->fr_offset;
2501 address = fragP->fr_address;
2502 table = TC_GENERIC_RELAX_TABLE;
2503 this_state = fragP->fr_subtype;
2504 start_type = this_type = table + this_state;
2505 symbolP = fragP->fr_symbol;
2511 sym_frag = symbol_get_frag (symbolP);
2513 #ifndef DIFF_EXPR_OK
2514 know (sym_frag != NULL);
2516 know (S_GET_SEGMENT (symbolP) != absolute_section
2517 || sym_frag == &zero_address_frag);
2518 target += S_GET_VALUE (symbolP);
2520 /* If SYM_FRAG has yet to be reached on this pass, assume it
2521 will move by STRETCH just as we did, unless there is an
2522 alignment frag between here and SYM_FRAG. An alignment may
2523 well absorb any STRETCH, and we don't want to choose a larger
2524 branch insn by overestimating the needed reach of this
2525 branch. It isn't critical to calculate TARGET exactly; We
2526 know we'll be doing another pass if STRETCH is non-zero. */
2529 && sym_frag->relax_marker != fragP->relax_marker
2530 && S_GET_SEGMENT (symbolP) == segment)
2533 || sym_frag->region == fragP->region)
2535 /* If we get here we know we have a forward branch. This
2536 relax pass may have stretched previous instructions so
2537 far that omitting STRETCH would make the branch
2538 negative. Don't allow this in case the negative reach is
2539 large enough to require a larger branch instruction. */
2540 else if (target < address)
2541 target = fragP->fr_next->fr_address + stretch;
2545 aim = target - address - fragP->fr_fix;
2546 #ifdef TC_PCREL_ADJUST
2547 /* Currently only the ns32k family needs this. */
2548 aim += TC_PCREL_ADJUST (fragP);
2551 #ifdef md_prepare_relax_scan
2552 /* Formerly called M68K_AIM_KLUDGE. */
2553 md_prepare_relax_scan (fragP, address, aim, this_state, this_type);
2558 /* Look backwards. */
2559 for (next_state = this_type->rlx_more; next_state;)
2560 if (aim >= this_type->rlx_backward)
2564 /* Grow to next state. */
2565 this_state = next_state;
2566 this_type = table + this_state;
2567 next_state = this_type->rlx_more;
2572 /* Look forwards. */
2573 for (next_state = this_type->rlx_more; next_state;)
2574 if (aim <= this_type->rlx_forward)
2578 /* Grow to next state. */
2579 this_state = next_state;
2580 this_type = table + this_state;
2581 next_state = this_type->rlx_more;
2585 growth = this_type->rlx_length - start_type->rlx_length;
2587 fragP->fr_subtype = this_state;
2591 #endif /* defined (TC_GENERIC_RELAX_TABLE) */
2593 /* Relax_align. Advance location counter to next address that has 'alignment'
2594 lowest order bits all 0s, return size of adjustment made. */
2595 static relax_addressT
2596 relax_align (relax_addressT address, /* Address now. */
2597 int alignment /* Alignment (binary). */)
2599 relax_addressT mask;
2600 relax_addressT new_address;
2602 mask = ~((relax_addressT) ~0 << alignment);
2603 new_address = (address + mask) & (~mask);
2604 #ifdef LINKER_RELAXING_SHRINKS_ONLY
2606 /* We must provide lots of padding, so the linker can discard it
2607 when needed. The linker will not add extra space, ever. */
2608 new_address += (1 << alignment);
2610 return (new_address - address);
2613 /* Now we have a segment, not a crowd of sub-segments, we can make
2618 After this, all frags in this segment have addresses that are correct
2619 within the segment. Since segments live in different file addresses,
2620 these frag addresses may not be the same as final object-file
2624 relax_segment (struct frag *segment_frag_root, segT segment, int pass)
2626 unsigned long frag_count;
2628 relax_addressT address;
2632 /* In case md_estimate_size_before_relax() wants to make fixSs. */
2633 subseg_change (segment, 0);
2635 /* For each frag in segment: count and store (a 1st guess of)
2639 for (frag_count = 0, fragP = segment_frag_root;
2641 fragP = fragP->fr_next, frag_count ++)
2643 fragP->region = region;
2644 fragP->relax_marker = 0;
2645 fragP->fr_address = address;
2646 address += fragP->fr_fix;
2648 switch (fragP->fr_type)
2651 address += fragP->fr_offset * fragP->fr_var;
2658 addressT offset = relax_align (address, (int) fragP->fr_offset);
2660 if (fragP->fr_subtype != 0 && offset > fragP->fr_subtype)
2663 if (offset % fragP->fr_var != 0)
2665 as_bad_where (fragP->fr_file, fragP->fr_line,
2666 ngettext ("alignment padding (%lu byte) "
2667 "not a multiple of %ld",
2668 "alignment padding (%lu bytes) "
2669 "not a multiple of %ld",
2670 (unsigned long) offset),
2671 (unsigned long) offset, (long) fragP->fr_var);
2672 offset -= (offset % fragP->fr_var);
2681 /* Assume .org is nugatory. It will grow with 1st relax. */
2689 case rs_machine_dependent:
2690 /* If fr_symbol is an expression, this call to
2691 resolve_symbol_value sets up the correct segment, which will
2692 likely be needed in md_estimate_size_before_relax. */
2693 if (fragP->fr_symbol)
2694 resolve_symbol_value (fragP->fr_symbol);
2696 address += md_estimate_size_before_relax (fragP, segment);
2699 #ifndef WORKING_DOT_WORD
2700 /* Broken words don't concern us yet. */
2701 case rs_broken_word:
2706 /* Initial guess is always 1; doing otherwise can result in
2707 stable solutions that are larger than the minimum. */
2708 address += fragP->fr_offset = 1;
2712 address += eh_frame_estimate_size_before_relax (fragP);
2716 address += dwarf2dbg_estimate_size_before_relax (fragP);
2720 BAD_CASE (fragP->fr_type);
2727 unsigned long max_iterations;
2729 /* Cumulative address adjustment. */
2732 /* Have we made any adjustment this pass? We can't just test
2733 stretch because one piece of code may have grown and another
2737 /* Most horrible, but gcc may give us some exception data that
2738 is impossible to assemble, of the form
2742 .uleb128 end - start
2748 If the leb128 is two bytes in size, then end-start is 128*128,
2749 which requires a three byte leb128. If the leb128 is three
2750 bytes in size, then end-start is 128*128-1, which requires a
2751 two byte leb128. We work around this dilemma by inserting
2752 an extra 4 bytes of alignment just after the .align. This
2753 works because the data after the align is accessed relative to
2756 This counter is used in a tiny state machine to detect
2757 whether a leb128 followed by an align is impossible to
2759 int rs_leb128_fudge = 0;
2761 /* We want to prevent going into an infinite loop where one frag grows
2762 depending upon the location of a symbol which is in turn moved by
2763 the growing frag. eg:
2769 So we dictate that this algorithm can be at most O2. */
2770 max_iterations = frag_count * frag_count;
2771 /* Check for overflow. */
2772 if (max_iterations < frag_count)
2773 max_iterations = frag_count;
2781 for (fragP = segment_frag_root; fragP; fragP = fragP->fr_next)
2784 addressT was_address;
2788 fragP->relax_marker ^= 1;
2789 was_address = fragP->fr_address;
2790 address = fragP->fr_address += stretch;
2791 symbolP = fragP->fr_symbol;
2792 offset = fragP->fr_offset;
2794 switch (fragP->fr_type)
2796 case rs_fill: /* .fill never relaxes. */
2800 #ifndef WORKING_DOT_WORD
2801 /* JF: This is RMS's idea. I do *NOT* want to be blamed
2802 for it I do not want to write it. I do not want to have
2803 anything to do with it. This is not the proper way to
2804 implement this misfeature. */
2805 case rs_broken_word:
2807 struct broken_word *lie;
2808 struct broken_word *untruth;
2810 /* Yes this is ugly (storing the broken_word pointer
2811 in the symbol slot). Still, this whole chunk of
2812 code is ugly, and I don't feel like doing anything
2813 about it. Think of it as stubbornness in action. */
2815 for (lie = (struct broken_word *) (fragP->fr_symbol);
2816 lie && lie->dispfrag == fragP;
2817 lie = lie->next_broken_word)
2823 offset = (S_GET_VALUE (lie->add)
2825 - S_GET_VALUE (lie->sub));
2826 if (offset <= -32768 || offset >= 32767)
2828 if (flag_warn_displacement)
2831 sprint_value (buf, (addressT) lie->addnum);
2832 as_warn_where (fragP->fr_file, fragP->fr_line,
2833 _(".word %s-%s+%s didn't fit"),
2834 S_GET_NAME (lie->add),
2835 S_GET_NAME (lie->sub),
2838 if (fragP->fr_subtype == 0)
2840 fragP->fr_subtype++;
2841 growth += md_short_jump_size;
2844 /* Redirect *all* words of this table with the same
2845 target, lest we have to handle the case where the
2846 same target but with a offset that fits on this
2847 round overflows at the next relaxation round. */
2848 for (untruth = (struct broken_word *) (fragP->fr_symbol);
2849 untruth && untruth->dispfrag == lie->dispfrag;
2850 untruth = untruth->next_broken_word)
2851 if ((symbol_get_frag (untruth->add)
2852 == symbol_get_frag (lie->add))
2853 && (S_GET_VALUE (untruth->add)
2854 == S_GET_VALUE (lie->add)))
2857 untruth->use_jump = lie;
2861 growth += md_long_jump_size;
2866 } /* case rs_broken_word */
2872 addressT oldoff, newoff;
2874 oldoff = relax_align (was_address + fragP->fr_fix,
2876 newoff = relax_align (address + fragP->fr_fix,
2879 if (fragP->fr_subtype != 0)
2881 if (oldoff > fragP->fr_subtype)
2883 if (newoff > fragP->fr_subtype)
2887 growth = newoff - oldoff;
2889 /* If this align happens to follow a leb128 and
2890 we have determined that the leb128 is bouncing
2891 in size, then break the cycle by inserting an
2894 && (rs_leb128_fudge & 16) != 0
2895 && (rs_leb128_fudge & 15) >= 2)
2897 segment_info_type *seginfo = seg_info (segment);
2898 struct obstack *ob = &seginfo->frchainP->frch_obstack;
2901 newf = frag_alloc (ob);
2902 obstack_blank_fast (ob, fragP->fr_var);
2903 obstack_finish (ob);
2904 memcpy (newf, fragP, SIZEOF_STRUCT_FRAG);
2905 memcpy (newf->fr_literal,
2906 fragP->fr_literal + fragP->fr_fix,
2908 newf->fr_type = rs_fill;
2909 newf->fr_address = address + fragP->fr_fix + newoff;
2911 newf->fr_offset = (((offsetT) 1 << fragP->fr_offset)
2913 if (newf->fr_offset * newf->fr_var
2914 != (offsetT) 1 << fragP->fr_offset)
2916 newf->fr_offset = (offsetT) 1 << fragP->fr_offset;
2919 /* Include size of new frag in GROWTH. */
2920 growth += newf->fr_offset * newf->fr_var;
2921 /* Adjust the new frag address for the amount
2922 we'll add when we process the new frag. */
2923 newf->fr_address -= stretch + growth;
2924 newf->relax_marker ^= 1;
2925 fragP->fr_next = newf;
2927 as_warn (_("padding added"));
2935 addressT target = offset;
2940 /* Convert from an actual address to an octet offset
2941 into the section. Here it is assumed that the
2942 section's VMA is zero, and can omit subtracting it
2943 from the symbol's value to get the address offset. */
2944 know (S_GET_SEGMENT (symbolP)->vma == 0);
2945 target += S_GET_VALUE (symbolP) * OCTETS_PER_BYTE;
2948 know (fragP->fr_next);
2949 after = fragP->fr_next->fr_address + stretch;
2950 growth = target - after;
2952 /* Growth may be negative, but variable part of frag
2953 cannot have fewer than 0 chars. That is, we can't
2955 if (address + fragP->fr_fix > target)
2959 /* Don't error on first few frag relax passes.
2960 The symbol might be an expression involving
2961 symbol values from other sections. If those
2962 sections have not yet been processed their
2963 frags will all have zero addresses, so we
2964 will calculate incorrect values for them. The
2965 number of passes we allow before giving an
2966 error is somewhat arbitrary. It should be at
2967 least one, with larger values requiring
2968 increasingly contrived dependencies between
2969 frags to trigger a false error. */
2972 /* Force another pass. */
2977 as_bad_where (fragP->fr_file, fragP->fr_line,
2978 _("attempt to move .org backwards"));
2980 /* We've issued an error message. Change the
2981 frag to avoid cascading errors. */
2982 fragP->fr_type = rs_align;
2983 fragP->fr_subtype = 0;
2984 fragP->fr_offset = 0;
2985 fragP->fr_fix = after - address;
2997 amount = S_GET_VALUE (symbolP);
2998 if (S_GET_SEGMENT (symbolP) != absolute_section
2999 || S_IS_COMMON (symbolP)
3000 || ! S_IS_DEFINED (symbolP))
3002 as_bad_where (fragP->fr_file, fragP->fr_line,
3003 _(".space specifies non-absolute value"));
3004 /* Prevent repeat of this error message. */
3005 fragP->fr_symbol = 0;
3007 else if (amount < 0)
3009 /* Don't error on first few frag relax passes.
3010 See rs_org comment for a longer explanation. */
3017 as_warn_where (fragP->fr_file, fragP->fr_line,
3018 _(".space, .nops or .fill with negative value, ignored"));
3019 fragP->fr_symbol = 0;
3022 growth = (was_address + fragP->fr_fix + amount
3023 - fragP->fr_next->fr_address);
3027 case rs_machine_dependent:
3028 #ifdef md_relax_frag
3029 growth = md_relax_frag (segment, fragP, stretch);
3031 #ifdef TC_GENERIC_RELAX_TABLE
3032 /* The default way to relax a frag is to look through
3033 TC_GENERIC_RELAX_TABLE. */
3034 growth = relax_frag (segment, fragP, stretch);
3035 #endif /* TC_GENERIC_RELAX_TABLE */
3044 value = resolve_symbol_value (fragP->fr_symbol);
3045 size = sizeof_leb128 (value, fragP->fr_subtype);
3046 growth = size - fragP->fr_offset;
3047 fragP->fr_offset = size;
3052 growth = eh_frame_relax_frag (fragP);
3056 growth = dwarf2dbg_relax_frag (fragP);
3060 BAD_CASE (fragP->fr_type);
3067 if (fragP->fr_type == rs_leb128)
3068 rs_leb128_fudge += 16;
3069 else if (fragP->fr_type == rs_align
3070 && (rs_leb128_fudge & 16) != 0
3072 rs_leb128_fudge += 16;
3074 rs_leb128_fudge = 0;
3079 && (rs_leb128_fudge & 16) == 0
3080 && (rs_leb128_fudge & -16) != 0)
3081 rs_leb128_fudge += 1;
3083 rs_leb128_fudge = 0;
3085 /* Until nothing further to relax. */
3086 while (stretched && -- max_iterations);
3089 as_fatal (_("Infinite loop encountered whilst attempting to compute the addresses of symbols in section %s"),
3090 segment_name (segment));
3093 for (fragP = segment_frag_root; fragP; fragP = fragP->fr_next)
3094 if (fragP->last_fr_address != fragP->fr_address)
3096 fragP->last_fr_address = fragP->fr_address;
3103 number_to_chars_bigendian (char *buf, valueT val, int n)
3109 buf[n] = val & 0xff;
3115 number_to_chars_littleendian (char *buf, valueT val, int n)
3121 *buf++ = val & 0xff;
3127 write_print_statistics (FILE *file)
3129 fprintf (file, "fixups: %d\n", n_fixups);
3132 /* For debugging. */
3133 extern int indent_level;
3136 print_fixup (fixS *fixp)
3139 fprintf (stderr, "fix ");
3140 fprintf_vma (stderr, (bfd_vma)((bfd_hostptr_t) fixp));
3141 fprintf (stderr, " %s:%d",fixp->fx_file, fixp->fx_line);
3143 fprintf (stderr, " pcrel");
3144 if (fixp->fx_pcrel_adjust)
3145 fprintf (stderr, " pcrel_adjust=%d", fixp->fx_pcrel_adjust);
3146 if (fixp->fx_im_disp)
3149 fprintf (stderr, " im_disp=%d", fixp->fx_im_disp);
3151 fprintf (stderr, " im_disp");
3155 fprintf (stderr, " tcbit");
3157 fprintf (stderr, " done");
3158 fprintf (stderr, "\n size=%d frag=", fixp->fx_size);
3159 fprintf_vma (stderr, (bfd_vma) ((bfd_hostptr_t) fixp->fx_frag));
3160 fprintf (stderr, " where=%ld offset=%lx addnumber=%lx",
3161 (long) fixp->fx_where,
3162 (unsigned long) fixp->fx_offset,
3163 (unsigned long) fixp->fx_addnumber);
3164 fprintf (stderr, "\n %s (%d)", bfd_get_reloc_code_name (fixp->fx_r_type),
3168 fprintf (stderr, "\n +<");
3169 print_symbol_value_1 (stderr, fixp->fx_addsy);
3170 fprintf (stderr, ">");
3174 fprintf (stderr, "\n -<");
3175 print_symbol_value_1 (stderr, fixp->fx_subsy);
3176 fprintf (stderr, ">");
3178 fprintf (stderr, "\n");
3179 #ifdef TC_FIX_DATA_PRINT
3180 TC_FIX_DATA_PRINT (stderr, fixp);