2000-07-20 H.J. Lu <hjl@gnu.org>
[deliverable/binutils-gdb.git] / bfd / reloc.c
1 /* BFD support for handling relocation entries.
2 Copyright (C) 1990, 91, 92, 93, 94, 95, 96, 97, 98, 99, 2000
3 Free Software Foundation, Inc.
4 Written by Cygnus Support.
5
6 This file is part of BFD, the Binary File Descriptor library.
7
8 This program 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 2 of the License, or
11 (at your option) any later version.
12
13 This program 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.
17
18 You should have received a copy of the GNU General Public License
19 along with this program; if not, write to the Free Software
20 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
21
22 /*
23 SECTION
24 Relocations
25
26 BFD maintains relocations in much the same way it maintains
27 symbols: they are left alone until required, then read in
28 en-masse and translated into an internal form. A common
29 routine <<bfd_perform_relocation>> acts upon the
30 canonical form to do the fixup.
31
32 Relocations are maintained on a per section basis,
33 while symbols are maintained on a per BFD basis.
34
35 All that a back end has to do to fit the BFD interface is to create
36 a <<struct reloc_cache_entry>> for each relocation
37 in a particular section, and fill in the right bits of the structures.
38
39 @menu
40 @* typedef arelent::
41 @* howto manager::
42 @end menu
43
44 */
45
46 /* DO compile in the reloc_code name table from libbfd.h. */
47 #define _BFD_MAKE_TABLE_bfd_reloc_code_real
48
49 #include "bfd.h"
50 #include "sysdep.h"
51 #include "bfdlink.h"
52 #include "libbfd.h"
53 /*
54 DOCDD
55 INODE
56 typedef arelent, howto manager, Relocations, Relocations
57
58 SUBSECTION
59 typedef arelent
60
61 This is the structure of a relocation entry:
62
63 CODE_FRAGMENT
64 .
65 .typedef enum bfd_reloc_status
66 .{
67 . {* No errors detected *}
68 . bfd_reloc_ok,
69 .
70 . {* The relocation was performed, but there was an overflow. *}
71 . bfd_reloc_overflow,
72 .
73 . {* The address to relocate was not within the section supplied. *}
74 . bfd_reloc_outofrange,
75 .
76 . {* Used by special functions *}
77 . bfd_reloc_continue,
78 .
79 . {* Unsupported relocation size requested. *}
80 . bfd_reloc_notsupported,
81 .
82 . {* Unused *}
83 . bfd_reloc_other,
84 .
85 . {* The symbol to relocate against was undefined. *}
86 . bfd_reloc_undefined,
87 .
88 . {* The relocation was performed, but may not be ok - presently
89 . generated only when linking i960 coff files with i960 b.out
90 . symbols. If this type is returned, the error_message argument
91 . to bfd_perform_relocation will be set. *}
92 . bfd_reloc_dangerous
93 . }
94 . bfd_reloc_status_type;
95 .
96 .
97 .typedef struct reloc_cache_entry
98 .{
99 . {* A pointer into the canonical table of pointers *}
100 . struct symbol_cache_entry **sym_ptr_ptr;
101 .
102 . {* offset in section *}
103 . bfd_size_type address;
104 .
105 . {* addend for relocation value *}
106 . bfd_vma addend;
107 .
108 . {* Pointer to how to perform the required relocation *}
109 . reloc_howto_type *howto;
110 .
111 .} arelent;
112
113 */
114
115 /*
116 DESCRIPTION
117
118 Here is a description of each of the fields within an <<arelent>>:
119
120 o <<sym_ptr_ptr>>
121
122 The symbol table pointer points to a pointer to the symbol
123 associated with the relocation request. It is
124 the pointer into the table returned by the back end's
125 <<get_symtab>> action. @xref{Symbols}. The symbol is referenced
126 through a pointer to a pointer so that tools like the linker
127 can fix up all the symbols of the same name by modifying only
128 one pointer. The relocation routine looks in the symbol and
129 uses the base of the section the symbol is attached to and the
130 value of the symbol as the initial relocation offset. If the
131 symbol pointer is zero, then the section provided is looked up.
132
133 o <<address>>
134
135 The <<address>> field gives the offset in bytes from the base of
136 the section data which owns the relocation record to the first
137 byte of relocatable information. The actual data relocated
138 will be relative to this point; for example, a relocation
139 type which modifies the bottom two bytes of a four byte word
140 would not touch the first byte pointed to in a big endian
141 world.
142
143 o <<addend>>
144
145 The <<addend>> is a value provided by the back end to be added (!)
146 to the relocation offset. Its interpretation is dependent upon
147 the howto. For example, on the 68k the code:
148
149
150 | char foo[];
151 | main()
152 | {
153 | return foo[0x12345678];
154 | }
155
156 Could be compiled into:
157
158 | linkw fp,#-4
159 | moveb @@#12345678,d0
160 | extbl d0
161 | unlk fp
162 | rts
163
164
165 This could create a reloc pointing to <<foo>>, but leave the
166 offset in the data, something like:
167
168
169 |RELOCATION RECORDS FOR [.text]:
170 |offset type value
171 |00000006 32 _foo
172 |
173 |00000000 4e56 fffc ; linkw fp,#-4
174 |00000004 1039 1234 5678 ; moveb @@#12345678,d0
175 |0000000a 49c0 ; extbl d0
176 |0000000c 4e5e ; unlk fp
177 |0000000e 4e75 ; rts
178
179
180 Using coff and an 88k, some instructions don't have enough
181 space in them to represent the full address range, and
182 pointers have to be loaded in two parts. So you'd get something like:
183
184
185 | or.u r13,r0,hi16(_foo+0x12345678)
186 | ld.b r2,r13,lo16(_foo+0x12345678)
187 | jmp r1
188
189
190 This should create two relocs, both pointing to <<_foo>>, and with
191 0x12340000 in their addend field. The data would consist of:
192
193
194 |RELOCATION RECORDS FOR [.text]:
195 |offset type value
196 |00000002 HVRT16 _foo+0x12340000
197 |00000006 LVRT16 _foo+0x12340000
198 |
199 |00000000 5da05678 ; or.u r13,r0,0x5678
200 |00000004 1c4d5678 ; ld.b r2,r13,0x5678
201 |00000008 f400c001 ; jmp r1
202
203
204 The relocation routine digs out the value from the data, adds
205 it to the addend to get the original offset, and then adds the
206 value of <<_foo>>. Note that all 32 bits have to be kept around
207 somewhere, to cope with carry from bit 15 to bit 16.
208
209 One further example is the sparc and the a.out format. The
210 sparc has a similar problem to the 88k, in that some
211 instructions don't have room for an entire offset, but on the
212 sparc the parts are created in odd sized lumps. The designers of
213 the a.out format chose to not use the data within the section
214 for storing part of the offset; all the offset is kept within
215 the reloc. Anything in the data should be ignored.
216
217 | save %sp,-112,%sp
218 | sethi %hi(_foo+0x12345678),%g2
219 | ldsb [%g2+%lo(_foo+0x12345678)],%i0
220 | ret
221 | restore
222
223 Both relocs contain a pointer to <<foo>>, and the offsets
224 contain junk.
225
226
227 |RELOCATION RECORDS FOR [.text]:
228 |offset type value
229 |00000004 HI22 _foo+0x12345678
230 |00000008 LO10 _foo+0x12345678
231 |
232 |00000000 9de3bf90 ; save %sp,-112,%sp
233 |00000004 05000000 ; sethi %hi(_foo+0),%g2
234 |00000008 f048a000 ; ldsb [%g2+%lo(_foo+0)],%i0
235 |0000000c 81c7e008 ; ret
236 |00000010 81e80000 ; restore
237
238
239 o <<howto>>
240
241 The <<howto>> field can be imagined as a
242 relocation instruction. It is a pointer to a structure which
243 contains information on what to do with all of the other
244 information in the reloc record and data section. A back end
245 would normally have a relocation instruction set and turn
246 relocations into pointers to the correct structure on input -
247 but it would be possible to create each howto field on demand.
248
249 */
250
251 /*
252 SUBSUBSECTION
253 <<enum complain_overflow>>
254
255 Indicates what sort of overflow checking should be done when
256 performing a relocation.
257
258 CODE_FRAGMENT
259 .
260 .enum complain_overflow
261 .{
262 . {* Do not complain on overflow. *}
263 . complain_overflow_dont,
264 .
265 . {* Complain if the bitfield overflows, whether it is considered
266 . as signed or unsigned. *}
267 . complain_overflow_bitfield,
268 .
269 . {* Complain if the value overflows when considered as signed
270 . number. *}
271 . complain_overflow_signed,
272 .
273 . {* Complain if the value overflows when considered as an
274 . unsigned number. *}
275 . complain_overflow_unsigned
276 .};
277
278 */
279
280 /*
281 SUBSUBSECTION
282 <<reloc_howto_type>>
283
284 The <<reloc_howto_type>> is a structure which contains all the
285 information that libbfd needs to know to tie up a back end's data.
286
287 CODE_FRAGMENT
288 .struct symbol_cache_entry; {* Forward declaration *}
289 .
290 .struct reloc_howto_struct
291 .{
292 . {* The type field has mainly a documentary use - the back end can
293 . do what it wants with it, though normally the back end's
294 . external idea of what a reloc number is stored
295 . in this field. For example, a PC relative word relocation
296 . in a coff environment has the type 023 - because that's
297 . what the outside world calls a R_PCRWORD reloc. *}
298 . unsigned int type;
299 .
300 . {* The value the final relocation is shifted right by. This drops
301 . unwanted data from the relocation. *}
302 . unsigned int rightshift;
303 .
304 . {* The size of the item to be relocated. This is *not* a
305 . power-of-two measure. To get the number of bytes operated
306 . on by a type of relocation, use bfd_get_reloc_size. *}
307 . int size;
308 .
309 . {* The number of bits in the item to be relocated. This is used
310 . when doing overflow checking. *}
311 . unsigned int bitsize;
312 .
313 . {* Notes that the relocation is relative to the location in the
314 . data section of the addend. The relocation function will
315 . subtract from the relocation value the address of the location
316 . being relocated. *}
317 . boolean pc_relative;
318 .
319 . {* The bit position of the reloc value in the destination.
320 . The relocated value is left shifted by this amount. *}
321 . unsigned int bitpos;
322 .
323 . {* What type of overflow error should be checked for when
324 . relocating. *}
325 . enum complain_overflow complain_on_overflow;
326 .
327 . {* If this field is non null, then the supplied function is
328 . called rather than the normal function. This allows really
329 . strange relocation methods to be accomodated (e.g., i960 callj
330 . instructions). *}
331 . bfd_reloc_status_type (*special_function)
332 . PARAMS ((bfd *abfd,
333 . arelent *reloc_entry,
334 . struct symbol_cache_entry *symbol,
335 . PTR data,
336 . asection *input_section,
337 . bfd *output_bfd,
338 . char **error_message));
339 .
340 . {* The textual name of the relocation type. *}
341 . char *name;
342 .
343 . {* Some formats record a relocation addend in the section contents
344 . rather than with the relocation. For ELF formats this is the
345 . distinction between USE_REL and USE_RELA (though the code checks
346 . for USE_REL == 1/0). The value of this field is TRUE if the
347 . addend is recorded with the section contents; when performing a
348 . partial link (ld -r) the section contents (the data) will be
349 . modified. The value of this field is FALSE if addends are
350 . recorded with the relocation (in arelent.addend); when performing
351 . a partial link the relocation will be modified.
352 . All relocations for all ELF USE_RELA targets should set this field
353 . to FALSE (values of TRUE should be looked on with suspicion).
354 . However, the converse is not true: not all relocations of all ELF
355 . USE_REL targets set this field to TRUE. Why this is so is peculiar
356 . to each particular target. For relocs that aren't used in partial
357 . links (e.g. GOT stuff) it doesn't matter what this is set to. *}
358 . boolean partial_inplace;
359 .
360 . {* The src_mask selects which parts of the read in data
361 . are to be used in the relocation sum. E.g., if this was an 8 bit
362 . byte of data which we read and relocated, this would be
363 . 0x000000ff. When we have relocs which have an addend, such as
364 . sun4 extended relocs, the value in the offset part of a
365 . relocating field is garbage so we never use it. In this case
366 . the mask would be 0x00000000. *}
367 . bfd_vma src_mask;
368 .
369 . {* The dst_mask selects which parts of the instruction are replaced
370 . into the instruction. In most cases src_mask == dst_mask,
371 . except in the above special case, where dst_mask would be
372 . 0x000000ff, and src_mask would be 0x00000000. *}
373 . bfd_vma dst_mask;
374 .
375 . {* When some formats create PC relative instructions, they leave
376 . the value of the pc of the place being relocated in the offset
377 . slot of the instruction, so that a PC relative relocation can
378 . be made just by adding in an ordinary offset (e.g., sun3 a.out).
379 . Some formats leave the displacement part of an instruction
380 . empty (e.g., m88k bcs); this flag signals the fact.*}
381 . boolean pcrel_offset;
382 .
383 .};
384
385 */
386
387 /*
388 FUNCTION
389 The HOWTO Macro
390
391 DESCRIPTION
392 The HOWTO define is horrible and will go away.
393
394
395 .#define HOWTO(C, R,S,B, P, BI, O, SF, NAME, INPLACE, MASKSRC, MASKDST, PC) \
396 . {(unsigned)C,R,S,B, P, BI, O,SF,NAME,INPLACE,MASKSRC,MASKDST,PC}
397
398 DESCRIPTION
399 And will be replaced with the totally magic way. But for the
400 moment, we are compatible, so do it this way.
401
402
403 .#define NEWHOWTO( FUNCTION, NAME,SIZE,REL,IN) HOWTO(0,0,SIZE,0,REL,0,complain_overflow_dont,FUNCTION, NAME,false,0,0,IN)
404 .
405
406 DESCRIPTION
407 This is used to fill in an empty howto entry in an array.
408
409 .#define EMPTY_HOWTO(C) \
410 . HOWTO((C),0,0,0,false,0,complain_overflow_dont,NULL,NULL,false,0,0,false)
411 .
412
413 DESCRIPTION
414 Helper routine to turn a symbol into a relocation value.
415
416 .#define HOWTO_PREPARE(relocation, symbol) \
417 . { \
418 . if (symbol != (asymbol *)NULL) { \
419 . if (bfd_is_com_section (symbol->section)) { \
420 . relocation = 0; \
421 . } \
422 . else { \
423 . relocation = symbol->value; \
424 . } \
425 . } \
426 .}
427
428 */
429
430 /*
431 FUNCTION
432 bfd_get_reloc_size
433
434 SYNOPSIS
435 unsigned int bfd_get_reloc_size (reloc_howto_type *);
436
437 DESCRIPTION
438 For a reloc_howto_type that operates on a fixed number of bytes,
439 this returns the number of bytes operated on.
440 */
441
442 unsigned int
443 bfd_get_reloc_size (howto)
444 reloc_howto_type *howto;
445 {
446 switch (howto->size)
447 {
448 case 0: return 1;
449 case 1: return 2;
450 case 2: return 4;
451 case 3: return 0;
452 case 4: return 8;
453 case 8: return 16;
454 case -2: return 4;
455 default: abort ();
456 }
457 }
458
459 /*
460 TYPEDEF
461 arelent_chain
462
463 DESCRIPTION
464
465 How relocs are tied together in an <<asection>>:
466
467 .typedef struct relent_chain {
468 . arelent relent;
469 . struct relent_chain *next;
470 .} arelent_chain;
471
472 */
473
474 /* N_ONES produces N one bits, without overflowing machine arithmetic. */
475 #define N_ONES(n) (((((bfd_vma) 1 << ((n) - 1)) - 1) << 1) | 1)
476
477 /*
478 FUNCTION
479 bfd_check_overflow
480
481 SYNOPSIS
482 bfd_reloc_status_type
483 bfd_check_overflow
484 (enum complain_overflow how,
485 unsigned int bitsize,
486 unsigned int rightshift,
487 unsigned int addrsize,
488 bfd_vma relocation);
489
490 DESCRIPTION
491 Perform overflow checking on @var{relocation} which has
492 @var{bitsize} significant bits and will be shifted right by
493 @var{rightshift} bits, on a machine with addresses containing
494 @var{addrsize} significant bits. The result is either of
495 @code{bfd_reloc_ok} or @code{bfd_reloc_overflow}.
496
497 */
498
499 bfd_reloc_status_type
500 bfd_check_overflow (how, bitsize, rightshift, addrsize, relocation)
501 enum complain_overflow how;
502 unsigned int bitsize;
503 unsigned int rightshift;
504 unsigned int addrsize;
505 bfd_vma relocation;
506 {
507 bfd_vma fieldmask, addrmask, signmask, ss, a;
508 bfd_reloc_status_type flag = bfd_reloc_ok;
509
510 a = relocation;
511
512 /* Note: BITSIZE should always be <= ADDRSIZE, but in case it's not,
513 we'll be permissive: extra bits in the field mask will
514 automatically extend the address mask for purposes of the
515 overflow check. */
516 fieldmask = N_ONES (bitsize);
517 addrmask = N_ONES (addrsize) | fieldmask;
518
519 switch (how)
520 {
521 case complain_overflow_dont:
522 break;
523
524 case complain_overflow_signed:
525 /* If any sign bits are set, all sign bits must be set. That
526 is, A must be a valid negative address after shifting. */
527 a = (a & addrmask) >> rightshift;
528 signmask = ~ (fieldmask >> 1);
529 ss = a & signmask;
530 if (ss != 0 && ss != ((addrmask >> rightshift) & signmask))
531 flag = bfd_reloc_overflow;
532 break;
533
534 case complain_overflow_unsigned:
535 /* We have an overflow if the address does not fit in the field. */
536 a = (a & addrmask) >> rightshift;
537 if ((a & ~ fieldmask) != 0)
538 flag = bfd_reloc_overflow;
539 break;
540
541 case complain_overflow_bitfield:
542 /* Bitfields are sometimes signed, sometimes unsigned. We
543 explicitly allow an address wrap too, which means a bitfield
544 of n bits is allowed to store -2**n to 2**n-1. Thus overflow
545 if the value has some, but not all, bits set outside the
546 field. */
547 a >>= rightshift;
548 ss = a & ~ fieldmask;
549 if (ss != 0 && ss != (((bfd_vma) -1 >> rightshift) & ~ fieldmask))
550 flag = bfd_reloc_overflow;
551 break;
552
553 default:
554 abort ();
555 }
556
557 return flag;
558 }
559
560 /*
561 FUNCTION
562 bfd_perform_relocation
563
564 SYNOPSIS
565 bfd_reloc_status_type
566 bfd_perform_relocation
567 (bfd *abfd,
568 arelent *reloc_entry,
569 PTR data,
570 asection *input_section,
571 bfd *output_bfd,
572 char **error_message);
573
574 DESCRIPTION
575 If @var{output_bfd} is supplied to this function, the
576 generated image will be relocatable; the relocations are
577 copied to the output file after they have been changed to
578 reflect the new state of the world. There are two ways of
579 reflecting the results of partial linkage in an output file:
580 by modifying the output data in place, and by modifying the
581 relocation record. Some native formats (e.g., basic a.out and
582 basic coff) have no way of specifying an addend in the
583 relocation type, so the addend has to go in the output data.
584 This is no big deal since in these formats the output data
585 slot will always be big enough for the addend. Complex reloc
586 types with addends were invented to solve just this problem.
587 The @var{error_message} argument is set to an error message if
588 this return @code{bfd_reloc_dangerous}.
589
590 */
591
592
593 bfd_reloc_status_type
594 bfd_perform_relocation (abfd, reloc_entry, data, input_section, output_bfd,
595 error_message)
596 bfd *abfd;
597 arelent *reloc_entry;
598 PTR data;
599 asection *input_section;
600 bfd *output_bfd;
601 char **error_message;
602 {
603 bfd_vma relocation;
604 bfd_reloc_status_type flag = bfd_reloc_ok;
605 bfd_size_type octets = reloc_entry->address * bfd_octets_per_byte (abfd);
606 bfd_vma output_base = 0;
607 reloc_howto_type *howto = reloc_entry->howto;
608 asection *reloc_target_output_section;
609 asymbol *symbol;
610
611 symbol = *(reloc_entry->sym_ptr_ptr);
612 if (bfd_is_abs_section (symbol->section)
613 && output_bfd != (bfd *) NULL)
614 {
615 reloc_entry->address += input_section->output_offset;
616 return bfd_reloc_ok;
617 }
618
619 /* If we are not producing relocateable output, return an error if
620 the symbol is not defined. An undefined weak symbol is
621 considered to have a value of zero (SVR4 ABI, p. 4-27). */
622 if (bfd_is_und_section (symbol->section)
623 && (symbol->flags & BSF_WEAK) == 0
624 && output_bfd == (bfd *) NULL)
625 flag = bfd_reloc_undefined;
626
627 /* If there is a function supplied to handle this relocation type,
628 call it. It'll return `bfd_reloc_continue' if further processing
629 can be done. */
630 if (howto->special_function)
631 {
632 bfd_reloc_status_type cont;
633 cont = howto->special_function (abfd, reloc_entry, symbol, data,
634 input_section, output_bfd,
635 error_message);
636 if (cont != bfd_reloc_continue)
637 return cont;
638 }
639
640 /* Is the address of the relocation really within the section? */
641 if (reloc_entry->address > input_section->_cooked_size /
642 bfd_octets_per_byte (abfd))
643 return bfd_reloc_outofrange;
644
645 /* Work out which section the relocation is targetted at and the
646 initial relocation command value. */
647
648 /* Get symbol value. (Common symbols are special.) */
649 if (bfd_is_com_section (symbol->section))
650 relocation = 0;
651 else
652 relocation = symbol->value;
653
654
655 reloc_target_output_section = symbol->section->output_section;
656
657 /* Convert input-section-relative symbol value to absolute. */
658 if (output_bfd && howto->partial_inplace == false)
659 output_base = 0;
660 else
661 output_base = reloc_target_output_section->vma;
662
663 relocation += output_base + symbol->section->output_offset;
664
665 /* Add in supplied addend. */
666 relocation += reloc_entry->addend;
667
668 /* Here the variable relocation holds the final address of the
669 symbol we are relocating against, plus any addend. */
670
671 if (howto->pc_relative == true)
672 {
673 /* This is a PC relative relocation. We want to set RELOCATION
674 to the distance between the address of the symbol and the
675 location. RELOCATION is already the address of the symbol.
676
677 We start by subtracting the address of the section containing
678 the location.
679
680 If pcrel_offset is set, we must further subtract the position
681 of the location within the section. Some targets arrange for
682 the addend to be the negative of the position of the location
683 within the section; for example, i386-aout does this. For
684 i386-aout, pcrel_offset is false. Some other targets do not
685 include the position of the location; for example, m88kbcs,
686 or ELF. For those targets, pcrel_offset is true.
687
688 If we are producing relocateable output, then we must ensure
689 that this reloc will be correctly computed when the final
690 relocation is done. If pcrel_offset is false we want to wind
691 up with the negative of the location within the section,
692 which means we must adjust the existing addend by the change
693 in the location within the section. If pcrel_offset is true
694 we do not want to adjust the existing addend at all.
695
696 FIXME: This seems logical to me, but for the case of
697 producing relocateable output it is not what the code
698 actually does. I don't want to change it, because it seems
699 far too likely that something will break. */
700
701 relocation -=
702 input_section->output_section->vma + input_section->output_offset;
703
704 if (howto->pcrel_offset == true)
705 relocation -= reloc_entry->address;
706 }
707
708 if (output_bfd != (bfd *) NULL)
709 {
710 if (howto->partial_inplace == false)
711 {
712 /* This is a partial relocation, and we want to apply the relocation
713 to the reloc entry rather than the raw data. Modify the reloc
714 inplace to reflect what we now know. */
715 reloc_entry->addend = relocation;
716 reloc_entry->address += input_section->output_offset;
717 return flag;
718 }
719 else
720 {
721 /* This is a partial relocation, but inplace, so modify the
722 reloc record a bit.
723
724 If we've relocated with a symbol with a section, change
725 into a ref to the section belonging to the symbol. */
726
727 reloc_entry->address += input_section->output_offset;
728
729 /* WTF?? */
730 if (abfd->xvec->flavour == bfd_target_coff_flavour
731 && strcmp (abfd->xvec->name, "coff-Intel-little") != 0
732 && strcmp (abfd->xvec->name, "coff-Intel-big") != 0)
733 {
734 #if 1
735 /* For m68k-coff, the addend was being subtracted twice during
736 relocation with -r. Removing the line below this comment
737 fixes that problem; see PR 2953.
738
739 However, Ian wrote the following, regarding removing the line below,
740 which explains why it is still enabled: --djm
741
742 If you put a patch like that into BFD you need to check all the COFF
743 linkers. I am fairly certain that patch will break coff-i386 (e.g.,
744 SCO); see coff_i386_reloc in coff-i386.c where I worked around the
745 problem in a different way. There may very well be a reason that the
746 code works as it does.
747
748 Hmmm. The first obvious point is that bfd_perform_relocation should
749 not have any tests that depend upon the flavour. It's seem like
750 entirely the wrong place for such a thing. The second obvious point
751 is that the current code ignores the reloc addend when producing
752 relocateable output for COFF. That's peculiar. In fact, I really
753 have no idea what the point of the line you want to remove is.
754
755 A typical COFF reloc subtracts the old value of the symbol and adds in
756 the new value to the location in the object file (if it's a pc
757 relative reloc it adds the difference between the symbol value and the
758 location). When relocating we need to preserve that property.
759
760 BFD handles this by setting the addend to the negative of the old
761 value of the symbol. Unfortunately it handles common symbols in a
762 non-standard way (it doesn't subtract the old value) but that's a
763 different story (we can't change it without losing backward
764 compatibility with old object files) (coff-i386 does subtract the old
765 value, to be compatible with existing coff-i386 targets, like SCO).
766
767 So everything works fine when not producing relocateable output. When
768 we are producing relocateable output, logically we should do exactly
769 what we do when not producing relocateable output. Therefore, your
770 patch is correct. In fact, it should probably always just set
771 reloc_entry->addend to 0 for all cases, since it is, in fact, going to
772 add the value into the object file. This won't hurt the COFF code,
773 which doesn't use the addend; I'm not sure what it will do to other
774 formats (the thing to check for would be whether any formats both use
775 the addend and set partial_inplace).
776
777 When I wanted to make coff-i386 produce relocateable output, I ran
778 into the problem that you are running into: I wanted to remove that
779 line. Rather than risk it, I made the coff-i386 relocs use a special
780 function; it's coff_i386_reloc in coff-i386.c. The function
781 specifically adds the addend field into the object file, knowing that
782 bfd_perform_relocation is not going to. If you remove that line, then
783 coff-i386.c will wind up adding the addend field in twice. It's
784 trivial to fix; it just needs to be done.
785
786 The problem with removing the line is just that it may break some
787 working code. With BFD it's hard to be sure of anything. The right
788 way to deal with this is simply to build and test at least all the
789 supported COFF targets. It should be straightforward if time and disk
790 space consuming. For each target:
791 1) build the linker
792 2) generate some executable, and link it using -r (I would
793 probably use paranoia.o and link against newlib/libc.a, which
794 for all the supported targets would be available in
795 /usr/cygnus/progressive/H-host/target/lib/libc.a).
796 3) make the change to reloc.c
797 4) rebuild the linker
798 5) repeat step 2
799 6) if the resulting object files are the same, you have at least
800 made it no worse
801 7) if they are different you have to figure out which version is
802 right
803 */
804 relocation -= reloc_entry->addend;
805 #endif
806 reloc_entry->addend = 0;
807 }
808 else
809 {
810 reloc_entry->addend = relocation;
811 }
812 }
813 }
814 else
815 {
816 reloc_entry->addend = 0;
817 }
818
819 /* FIXME: This overflow checking is incomplete, because the value
820 might have overflowed before we get here. For a correct check we
821 need to compute the value in a size larger than bitsize, but we
822 can't reasonably do that for a reloc the same size as a host
823 machine word.
824 FIXME: We should also do overflow checking on the result after
825 adding in the value contained in the object file. */
826 if (howto->complain_on_overflow != complain_overflow_dont
827 && flag == bfd_reloc_ok)
828 flag = bfd_check_overflow (howto->complain_on_overflow,
829 howto->bitsize,
830 howto->rightshift,
831 bfd_arch_bits_per_address (abfd),
832 relocation);
833
834 /*
835 Either we are relocating all the way, or we don't want to apply
836 the relocation to the reloc entry (probably because there isn't
837 any room in the output format to describe addends to relocs)
838 */
839
840 /* The cast to bfd_vma avoids a bug in the Alpha OSF/1 C compiler
841 (OSF version 1.3, compiler version 3.11). It miscompiles the
842 following program:
843
844 struct str
845 {
846 unsigned int i0;
847 } s = { 0 };
848
849 int
850 main ()
851 {
852 unsigned long x;
853
854 x = 0x100000000;
855 x <<= (unsigned long) s.i0;
856 if (x == 0)
857 printf ("failed\n");
858 else
859 printf ("succeeded (%lx)\n", x);
860 }
861 */
862
863 relocation >>= (bfd_vma) howto->rightshift;
864
865 /* Shift everything up to where it's going to be used */
866
867 relocation <<= (bfd_vma) howto->bitpos;
868
869 /* Wait for the day when all have the mask in them */
870
871 /* What we do:
872 i instruction to be left alone
873 o offset within instruction
874 r relocation offset to apply
875 S src mask
876 D dst mask
877 N ~dst mask
878 A part 1
879 B part 2
880 R result
881
882 Do this:
883 (( i i i i i o o o o o from bfd_get<size>
884 and S S S S S) to get the size offset we want
885 + r r r r r r r r r r) to get the final value to place
886 and D D D D D to chop to right size
887 -----------------------
888 = A A A A A
889 And this:
890 ( i i i i i o o o o o from bfd_get<size>
891 and N N N N N ) get instruction
892 -----------------------
893 = B B B B B
894
895 And then:
896 ( B B B B B
897 or A A A A A)
898 -----------------------
899 = R R R R R R R R R R put into bfd_put<size>
900 */
901
902 #define DOIT(x) \
903 x = ( (x & ~howto->dst_mask) | (((x & howto->src_mask) + relocation) & howto->dst_mask))
904
905 switch (howto->size)
906 {
907 case 0:
908 {
909 char x = bfd_get_8 (abfd, (char *) data + octets);
910 DOIT (x);
911 bfd_put_8 (abfd, x, (unsigned char *) data + octets);
912 }
913 break;
914
915 case 1:
916 {
917 short x = bfd_get_16 (abfd, (bfd_byte *) data + octets);
918 DOIT (x);
919 bfd_put_16 (abfd, x, (unsigned char *) data + octets);
920 }
921 break;
922 case 2:
923 {
924 long x = bfd_get_32 (abfd, (bfd_byte *) data + octets);
925 DOIT (x);
926 bfd_put_32 (abfd, x, (bfd_byte *) data + octets);
927 }
928 break;
929 case -2:
930 {
931 long x = bfd_get_32 (abfd, (bfd_byte *) data + octets);
932 relocation = -relocation;
933 DOIT (x);
934 bfd_put_32 (abfd, x, (bfd_byte *) data + octets);
935 }
936 break;
937
938 case -1:
939 {
940 long x = bfd_get_16 (abfd, (bfd_byte *) data + octets);
941 relocation = -relocation;
942 DOIT (x);
943 bfd_put_16 (abfd, x, (bfd_byte *) data + octets);
944 }
945 break;
946
947 case 3:
948 /* Do nothing */
949 break;
950
951 case 4:
952 #ifdef BFD64
953 {
954 bfd_vma x = bfd_get_64 (abfd, (bfd_byte *) data + octets);
955 DOIT (x);
956 bfd_put_64 (abfd, x, (bfd_byte *) data + octets);
957 }
958 #else
959 abort ();
960 #endif
961 break;
962 default:
963 return bfd_reloc_other;
964 }
965
966 return flag;
967 }
968
969 /*
970 FUNCTION
971 bfd_install_relocation
972
973 SYNOPSIS
974 bfd_reloc_status_type
975 bfd_install_relocation
976 (bfd *abfd,
977 arelent *reloc_entry,
978 PTR data, bfd_vma data_start,
979 asection *input_section,
980 char **error_message);
981
982 DESCRIPTION
983 This looks remarkably like <<bfd_perform_relocation>>, except it
984 does not expect that the section contents have been filled in.
985 I.e., it's suitable for use when creating, rather than applying
986 a relocation.
987
988 For now, this function should be considered reserved for the
989 assembler.
990
991 */
992
993
994 bfd_reloc_status_type
995 bfd_install_relocation (abfd, reloc_entry, data_start, data_start_offset,
996 input_section, error_message)
997 bfd *abfd;
998 arelent *reloc_entry;
999 PTR data_start;
1000 bfd_vma data_start_offset;
1001 asection *input_section;
1002 char **error_message;
1003 {
1004 bfd_vma relocation;
1005 bfd_reloc_status_type flag = bfd_reloc_ok;
1006 bfd_size_type octets = reloc_entry->address * bfd_octets_per_byte (abfd);
1007 bfd_vma output_base = 0;
1008 reloc_howto_type *howto = reloc_entry->howto;
1009 asection *reloc_target_output_section;
1010 asymbol *symbol;
1011 bfd_byte *data;
1012
1013 symbol = *(reloc_entry->sym_ptr_ptr);
1014 if (bfd_is_abs_section (symbol->section))
1015 {
1016 reloc_entry->address += input_section->output_offset;
1017 return bfd_reloc_ok;
1018 }
1019
1020 /* If there is a function supplied to handle this relocation type,
1021 call it. It'll return `bfd_reloc_continue' if further processing
1022 can be done. */
1023 if (howto->special_function)
1024 {
1025 bfd_reloc_status_type cont;
1026
1027 /* XXX - The special_function calls haven't been fixed up to deal
1028 with creating new relocations and section contents. */
1029 cont = howto->special_function (abfd, reloc_entry, symbol,
1030 /* XXX - Non-portable! */
1031 ((bfd_byte *) data_start
1032 - data_start_offset),
1033 input_section, abfd, error_message);
1034 if (cont != bfd_reloc_continue)
1035 return cont;
1036 }
1037
1038 /* Is the address of the relocation really within the section? */
1039 if (reloc_entry->address > input_section->_cooked_size)
1040 return bfd_reloc_outofrange;
1041
1042 /* Work out which section the relocation is targetted at and the
1043 initial relocation command value. */
1044
1045 /* Get symbol value. (Common symbols are special.) */
1046 if (bfd_is_com_section (symbol->section))
1047 relocation = 0;
1048 else
1049 relocation = symbol->value;
1050
1051 reloc_target_output_section = symbol->section->output_section;
1052
1053 /* Convert input-section-relative symbol value to absolute. */
1054 if (howto->partial_inplace == false)
1055 output_base = 0;
1056 else
1057 output_base = reloc_target_output_section->vma;
1058
1059 relocation += output_base + symbol->section->output_offset;
1060
1061 /* Add in supplied addend. */
1062 relocation += reloc_entry->addend;
1063
1064 /* Here the variable relocation holds the final address of the
1065 symbol we are relocating against, plus any addend. */
1066
1067 if (howto->pc_relative == true)
1068 {
1069 /* This is a PC relative relocation. We want to set RELOCATION
1070 to the distance between the address of the symbol and the
1071 location. RELOCATION is already the address of the symbol.
1072
1073 We start by subtracting the address of the section containing
1074 the location.
1075
1076 If pcrel_offset is set, we must further subtract the position
1077 of the location within the section. Some targets arrange for
1078 the addend to be the negative of the position of the location
1079 within the section; for example, i386-aout does this. For
1080 i386-aout, pcrel_offset is false. Some other targets do not
1081 include the position of the location; for example, m88kbcs,
1082 or ELF. For those targets, pcrel_offset is true.
1083
1084 If we are producing relocateable output, then we must ensure
1085 that this reloc will be correctly computed when the final
1086 relocation is done. If pcrel_offset is false we want to wind
1087 up with the negative of the location within the section,
1088 which means we must adjust the existing addend by the change
1089 in the location within the section. If pcrel_offset is true
1090 we do not want to adjust the existing addend at all.
1091
1092 FIXME: This seems logical to me, but for the case of
1093 producing relocateable output it is not what the code
1094 actually does. I don't want to change it, because it seems
1095 far too likely that something will break. */
1096
1097 relocation -=
1098 input_section->output_section->vma + input_section->output_offset;
1099
1100 if (howto->pcrel_offset == true && howto->partial_inplace == true)
1101 relocation -= reloc_entry->address;
1102 }
1103
1104 if (howto->partial_inplace == false)
1105 {
1106 /* This is a partial relocation, and we want to apply the relocation
1107 to the reloc entry rather than the raw data. Modify the reloc
1108 inplace to reflect what we now know. */
1109 reloc_entry->addend = relocation;
1110 reloc_entry->address += input_section->output_offset;
1111 return flag;
1112 }
1113 else
1114 {
1115 /* This is a partial relocation, but inplace, so modify the
1116 reloc record a bit.
1117
1118 If we've relocated with a symbol with a section, change
1119 into a ref to the section belonging to the symbol. */
1120
1121 reloc_entry->address += input_section->output_offset;
1122
1123 /* WTF?? */
1124 if (abfd->xvec->flavour == bfd_target_coff_flavour
1125 && strcmp (abfd->xvec->name, "coff-Intel-little") != 0
1126 && strcmp (abfd->xvec->name, "coff-Intel-big") != 0)
1127 {
1128 #if 1
1129 /* For m68k-coff, the addend was being subtracted twice during
1130 relocation with -r. Removing the line below this comment
1131 fixes that problem; see PR 2953.
1132
1133 However, Ian wrote the following, regarding removing the line below,
1134 which explains why it is still enabled: --djm
1135
1136 If you put a patch like that into BFD you need to check all the COFF
1137 linkers. I am fairly certain that patch will break coff-i386 (e.g.,
1138 SCO); see coff_i386_reloc in coff-i386.c where I worked around the
1139 problem in a different way. There may very well be a reason that the
1140 code works as it does.
1141
1142 Hmmm. The first obvious point is that bfd_install_relocation should
1143 not have any tests that depend upon the flavour. It's seem like
1144 entirely the wrong place for such a thing. The second obvious point
1145 is that the current code ignores the reloc addend when producing
1146 relocateable output for COFF. That's peculiar. In fact, I really
1147 have no idea what the point of the line you want to remove is.
1148
1149 A typical COFF reloc subtracts the old value of the symbol and adds in
1150 the new value to the location in the object file (if it's a pc
1151 relative reloc it adds the difference between the symbol value and the
1152 location). When relocating we need to preserve that property.
1153
1154 BFD handles this by setting the addend to the negative of the old
1155 value of the symbol. Unfortunately it handles common symbols in a
1156 non-standard way (it doesn't subtract the old value) but that's a
1157 different story (we can't change it without losing backward
1158 compatibility with old object files) (coff-i386 does subtract the old
1159 value, to be compatible with existing coff-i386 targets, like SCO).
1160
1161 So everything works fine when not producing relocateable output. When
1162 we are producing relocateable output, logically we should do exactly
1163 what we do when not producing relocateable output. Therefore, your
1164 patch is correct. In fact, it should probably always just set
1165 reloc_entry->addend to 0 for all cases, since it is, in fact, going to
1166 add the value into the object file. This won't hurt the COFF code,
1167 which doesn't use the addend; I'm not sure what it will do to other
1168 formats (the thing to check for would be whether any formats both use
1169 the addend and set partial_inplace).
1170
1171 When I wanted to make coff-i386 produce relocateable output, I ran
1172 into the problem that you are running into: I wanted to remove that
1173 line. Rather than risk it, I made the coff-i386 relocs use a special
1174 function; it's coff_i386_reloc in coff-i386.c. The function
1175 specifically adds the addend field into the object file, knowing that
1176 bfd_install_relocation is not going to. If you remove that line, then
1177 coff-i386.c will wind up adding the addend field in twice. It's
1178 trivial to fix; it just needs to be done.
1179
1180 The problem with removing the line is just that it may break some
1181 working code. With BFD it's hard to be sure of anything. The right
1182 way to deal with this is simply to build and test at least all the
1183 supported COFF targets. It should be straightforward if time and disk
1184 space consuming. For each target:
1185 1) build the linker
1186 2) generate some executable, and link it using -r (I would
1187 probably use paranoia.o and link against newlib/libc.a, which
1188 for all the supported targets would be available in
1189 /usr/cygnus/progressive/H-host/target/lib/libc.a).
1190 3) make the change to reloc.c
1191 4) rebuild the linker
1192 5) repeat step 2
1193 6) if the resulting object files are the same, you have at least
1194 made it no worse
1195 7) if they are different you have to figure out which version is
1196 right
1197 */
1198 relocation -= reloc_entry->addend;
1199 #endif
1200 reloc_entry->addend = 0;
1201 }
1202 else
1203 {
1204 reloc_entry->addend = relocation;
1205 }
1206 }
1207
1208 /* FIXME: This overflow checking is incomplete, because the value
1209 might have overflowed before we get here. For a correct check we
1210 need to compute the value in a size larger than bitsize, but we
1211 can't reasonably do that for a reloc the same size as a host
1212 machine word.
1213 FIXME: We should also do overflow checking on the result after
1214 adding in the value contained in the object file. */
1215 if (howto->complain_on_overflow != complain_overflow_dont)
1216 flag = bfd_check_overflow (howto->complain_on_overflow,
1217 howto->bitsize,
1218 howto->rightshift,
1219 bfd_arch_bits_per_address (abfd),
1220 relocation);
1221
1222 /*
1223 Either we are relocating all the way, or we don't want to apply
1224 the relocation to the reloc entry (probably because there isn't
1225 any room in the output format to describe addends to relocs)
1226 */
1227
1228 /* The cast to bfd_vma avoids a bug in the Alpha OSF/1 C compiler
1229 (OSF version 1.3, compiler version 3.11). It miscompiles the
1230 following program:
1231
1232 struct str
1233 {
1234 unsigned int i0;
1235 } s = { 0 };
1236
1237 int
1238 main ()
1239 {
1240 unsigned long x;
1241
1242 x = 0x100000000;
1243 x <<= (unsigned long) s.i0;
1244 if (x == 0)
1245 printf ("failed\n");
1246 else
1247 printf ("succeeded (%lx)\n", x);
1248 }
1249 */
1250
1251 relocation >>= (bfd_vma) howto->rightshift;
1252
1253 /* Shift everything up to where it's going to be used */
1254
1255 relocation <<= (bfd_vma) howto->bitpos;
1256
1257 /* Wait for the day when all have the mask in them */
1258
1259 /* What we do:
1260 i instruction to be left alone
1261 o offset within instruction
1262 r relocation offset to apply
1263 S src mask
1264 D dst mask
1265 N ~dst mask
1266 A part 1
1267 B part 2
1268 R result
1269
1270 Do this:
1271 (( i i i i i o o o o o from bfd_get<size>
1272 and S S S S S) to get the size offset we want
1273 + r r r r r r r r r r) to get the final value to place
1274 and D D D D D to chop to right size
1275 -----------------------
1276 = A A A A A
1277 And this:
1278 ( i i i i i o o o o o from bfd_get<size>
1279 and N N N N N ) get instruction
1280 -----------------------
1281 = B B B B B
1282
1283 And then:
1284 ( B B B B B
1285 or A A A A A)
1286 -----------------------
1287 = R R R R R R R R R R put into bfd_put<size>
1288 */
1289
1290 #define DOIT(x) \
1291 x = ( (x & ~howto->dst_mask) | (((x & howto->src_mask) + relocation) & howto->dst_mask))
1292
1293 data = (bfd_byte *) data_start + (octets - data_start_offset);
1294
1295 switch (howto->size)
1296 {
1297 case 0:
1298 {
1299 char x = bfd_get_8 (abfd, (char *) data);
1300 DOIT (x);
1301 bfd_put_8 (abfd, x, (unsigned char *) data);
1302 }
1303 break;
1304
1305 case 1:
1306 {
1307 short x = bfd_get_16 (abfd, (bfd_byte *) data);
1308 DOIT (x);
1309 bfd_put_16 (abfd, x, (unsigned char *) data);
1310 }
1311 break;
1312 case 2:
1313 {
1314 long x = bfd_get_32 (abfd, (bfd_byte *) data);
1315 DOIT (x);
1316 bfd_put_32 (abfd, x, (bfd_byte *) data);
1317 }
1318 break;
1319 case -2:
1320 {
1321 long x = bfd_get_32 (abfd, (bfd_byte *) data);
1322 relocation = -relocation;
1323 DOIT (x);
1324 bfd_put_32 (abfd, x, (bfd_byte *) data);
1325 }
1326 break;
1327
1328 case 3:
1329 /* Do nothing */
1330 break;
1331
1332 case 4:
1333 {
1334 bfd_vma x = bfd_get_64 (abfd, (bfd_byte *) data);
1335 DOIT (x);
1336 bfd_put_64 (abfd, x, (bfd_byte *) data);
1337 }
1338 break;
1339 default:
1340 return bfd_reloc_other;
1341 }
1342
1343 return flag;
1344 }
1345
1346 /* This relocation routine is used by some of the backend linkers.
1347 They do not construct asymbol or arelent structures, so there is no
1348 reason for them to use bfd_perform_relocation. Also,
1349 bfd_perform_relocation is so hacked up it is easier to write a new
1350 function than to try to deal with it.
1351
1352 This routine does a final relocation. Whether it is useful for a
1353 relocateable link depends upon how the object format defines
1354 relocations.
1355
1356 FIXME: This routine ignores any special_function in the HOWTO,
1357 since the existing special_function values have been written for
1358 bfd_perform_relocation.
1359
1360 HOWTO is the reloc howto information.
1361 INPUT_BFD is the BFD which the reloc applies to.
1362 INPUT_SECTION is the section which the reloc applies to.
1363 CONTENTS is the contents of the section.
1364 ADDRESS is the address of the reloc within INPUT_SECTION.
1365 VALUE is the value of the symbol the reloc refers to.
1366 ADDEND is the addend of the reloc. */
1367
1368 bfd_reloc_status_type
1369 _bfd_final_link_relocate (howto, input_bfd, input_section, contents, address,
1370 value, addend)
1371 reloc_howto_type *howto;
1372 bfd *input_bfd;
1373 asection *input_section;
1374 bfd_byte *contents;
1375 bfd_vma address;
1376 bfd_vma value;
1377 bfd_vma addend;
1378 {
1379 bfd_vma relocation;
1380
1381 /* Sanity check the address. */
1382 if (address > input_section->_raw_size)
1383 return bfd_reloc_outofrange;
1384
1385 /* This function assumes that we are dealing with a basic relocation
1386 against a symbol. We want to compute the value of the symbol to
1387 relocate to. This is just VALUE, the value of the symbol, plus
1388 ADDEND, any addend associated with the reloc. */
1389 relocation = value + addend;
1390
1391 /* If the relocation is PC relative, we want to set RELOCATION to
1392 the distance between the symbol (currently in RELOCATION) and the
1393 location we are relocating. Some targets (e.g., i386-aout)
1394 arrange for the contents of the section to be the negative of the
1395 offset of the location within the section; for such targets
1396 pcrel_offset is false. Other targets (e.g., m88kbcs or ELF)
1397 simply leave the contents of the section as zero; for such
1398 targets pcrel_offset is true. If pcrel_offset is false we do not
1399 need to subtract out the offset of the location within the
1400 section (which is just ADDRESS). */
1401 if (howto->pc_relative)
1402 {
1403 relocation -= (input_section->output_section->vma
1404 + input_section->output_offset);
1405 if (howto->pcrel_offset)
1406 relocation -= address;
1407 }
1408
1409 return _bfd_relocate_contents (howto, input_bfd, relocation,
1410 contents + address);
1411 }
1412
1413 /* Relocate a given location using a given value and howto. */
1414
1415 bfd_reloc_status_type
1416 _bfd_relocate_contents (howto, input_bfd, relocation, location)
1417 reloc_howto_type *howto;
1418 bfd *input_bfd;
1419 bfd_vma relocation;
1420 bfd_byte *location;
1421 {
1422 int size;
1423 bfd_vma x = 0;
1424 bfd_reloc_status_type flag;
1425 unsigned int rightshift = howto->rightshift;
1426 unsigned int bitpos = howto->bitpos;
1427
1428 /* If the size is negative, negate RELOCATION. This isn't very
1429 general. */
1430 if (howto->size < 0)
1431 relocation = -relocation;
1432
1433 /* Get the value we are going to relocate. */
1434 size = bfd_get_reloc_size (howto);
1435 switch (size)
1436 {
1437 default:
1438 case 0:
1439 abort ();
1440 case 1:
1441 x = bfd_get_8 (input_bfd, location);
1442 break;
1443 case 2:
1444 x = bfd_get_16 (input_bfd, location);
1445 break;
1446 case 4:
1447 x = bfd_get_32 (input_bfd, location);
1448 break;
1449 case 8:
1450 #ifdef BFD64
1451 x = bfd_get_64 (input_bfd, location);
1452 #else
1453 abort ();
1454 #endif
1455 break;
1456 }
1457
1458 /* Check for overflow. FIXME: We may drop bits during the addition
1459 which we don't check for. We must either check at every single
1460 operation, which would be tedious, or we must do the computations
1461 in a type larger than bfd_vma, which would be inefficient. */
1462 flag = bfd_reloc_ok;
1463 if (howto->complain_on_overflow != complain_overflow_dont)
1464 {
1465 bfd_vma addrmask, fieldmask, signmask, ss;
1466 bfd_vma a, b, sum;
1467
1468 /* Get the values to be added together. For signed and unsigned
1469 relocations, we assume that all values should be truncated to
1470 the size of an address. For bitfields, all the bits matter.
1471 See also bfd_check_overflow. */
1472 fieldmask = N_ONES (howto->bitsize);
1473 addrmask = N_ONES (bfd_arch_bits_per_address (input_bfd)) | fieldmask;
1474 a = relocation;
1475 b = x & howto->src_mask;
1476
1477 switch (howto->complain_on_overflow)
1478 {
1479 case complain_overflow_signed:
1480 a = (a & addrmask) >> rightshift;
1481
1482 /* If any sign bits are set, all sign bits must be set.
1483 That is, A must be a valid negative address after
1484 shifting. */
1485 signmask = ~ (fieldmask >> 1);
1486 ss = a & signmask;
1487 if (ss != 0 && ss != ((addrmask >> rightshift) & signmask))
1488 flag = bfd_reloc_overflow;
1489
1490 /* We only need this next bit of code if the sign bit of B
1491 is below the sign bit of A. This would only happen if
1492 SRC_MASK had fewer bits than BITSIZE. Note that if
1493 SRC_MASK has more bits than BITSIZE, we can get into
1494 trouble; we would need to verify that B is in range, as
1495 we do for A above. */
1496 signmask = ((~ howto->src_mask) >> 1) & howto->src_mask;
1497
1498 /* Set all the bits above the sign bit. */
1499 b = (b ^ signmask) - signmask;
1500
1501 b = (b & addrmask) >> bitpos;
1502
1503 /* Now we can do the addition. */
1504 sum = a + b;
1505
1506 /* See if the result has the correct sign. Bits above the
1507 sign bit are junk now; ignore them. If the sum is
1508 positive, make sure we did not have all negative inputs;
1509 if the sum is negative, make sure we did not have all
1510 positive inputs. The test below looks only at the sign
1511 bits, and it really just
1512 SIGN (A) == SIGN (B) && SIGN (A) != SIGN (SUM)
1513 */
1514 signmask = (fieldmask >> 1) + 1;
1515 if (((~ (a ^ b)) & (a ^ sum)) & signmask)
1516 flag = bfd_reloc_overflow;
1517
1518 break;
1519
1520 case complain_overflow_unsigned:
1521 /* Checking for an unsigned overflow is relatively easy:
1522 trim the addresses and add, and trim the result as well.
1523 Overflow is normally indicated when the result does not
1524 fit in the field. However, we also need to consider the
1525 case when, e.g., fieldmask is 0x7fffffff or smaller, an
1526 input is 0x80000000, and bfd_vma is only 32 bits; then we
1527 will get sum == 0, but there is an overflow, since the
1528 inputs did not fit in the field. Instead of doing a
1529 separate test, we can check for this by or-ing in the
1530 operands when testing for the sum overflowing its final
1531 field. */
1532 a = (a & addrmask) >> rightshift;
1533 b = (b & addrmask) >> bitpos;
1534 sum = (a + b) & addrmask;
1535 if ((a | b | sum) & ~ fieldmask)
1536 flag = bfd_reloc_overflow;
1537
1538 break;
1539
1540 case complain_overflow_bitfield:
1541 /* Much like the signed check, but for a field one bit
1542 wider, and no trimming inputs with addrmask. We allow a
1543 bitfield to represent numbers in the range -2**n to
1544 2**n-1, where n is the number of bits in the field.
1545 Note that when bfd_vma is 32 bits, a 32-bit reloc can't
1546 overflow, which is exactly what we want. */
1547 a >>= rightshift;
1548
1549 signmask = ~ fieldmask;
1550 ss = a & signmask;
1551 if (ss != 0 && ss != (((bfd_vma) -1 >> rightshift) & signmask))
1552 flag = bfd_reloc_overflow;
1553
1554 signmask = ((~ howto->src_mask) >> 1) & howto->src_mask;
1555 b = (b ^ signmask) - signmask;
1556
1557 b >>= bitpos;
1558
1559 sum = a + b;
1560
1561 /* We mask with addrmask here to explicitly allow an address
1562 wrap-around. The Linux kernel relies on it, and it is
1563 the only way to write assembler code which can run when
1564 loaded at a location 0x80000000 away from the location at
1565 which it is linked. */
1566 signmask = fieldmask + 1;
1567 if (((~ (a ^ b)) & (a ^ sum)) & signmask & addrmask)
1568 flag = bfd_reloc_overflow;
1569
1570 break;
1571
1572 default:
1573 abort ();
1574 }
1575 }
1576
1577 /* Put RELOCATION in the right bits. */
1578 relocation >>= (bfd_vma) rightshift;
1579 relocation <<= (bfd_vma) bitpos;
1580
1581 /* Add RELOCATION to the right bits of X. */
1582 x = ((x & ~howto->dst_mask)
1583 | (((x & howto->src_mask) + relocation) & howto->dst_mask));
1584
1585 /* Put the relocated value back in the object file. */
1586 switch (size)
1587 {
1588 default:
1589 case 0:
1590 abort ();
1591 case 1:
1592 bfd_put_8 (input_bfd, x, location);
1593 break;
1594 case 2:
1595 bfd_put_16 (input_bfd, x, location);
1596 break;
1597 case 4:
1598 bfd_put_32 (input_bfd, x, location);
1599 break;
1600 case 8:
1601 #ifdef BFD64
1602 bfd_put_64 (input_bfd, x, location);
1603 #else
1604 abort ();
1605 #endif
1606 break;
1607 }
1608
1609 return flag;
1610 }
1611
1612 /*
1613 DOCDD
1614 INODE
1615 howto manager, , typedef arelent, Relocations
1616
1617 SECTION
1618 The howto manager
1619
1620 When an application wants to create a relocation, but doesn't
1621 know what the target machine might call it, it can find out by
1622 using this bit of code.
1623
1624 */
1625
1626 /*
1627 TYPEDEF
1628 bfd_reloc_code_type
1629
1630 DESCRIPTION
1631 The insides of a reloc code. The idea is that, eventually, there
1632 will be one enumerator for every type of relocation we ever do.
1633 Pass one of these values to <<bfd_reloc_type_lookup>>, and it'll
1634 return a howto pointer.
1635
1636 This does mean that the application must determine the correct
1637 enumerator value; you can't get a howto pointer from a random set
1638 of attributes.
1639
1640 SENUM
1641 bfd_reloc_code_real
1642
1643 ENUM
1644 BFD_RELOC_64
1645 ENUMX
1646 BFD_RELOC_32
1647 ENUMX
1648 BFD_RELOC_26
1649 ENUMX
1650 BFD_RELOC_24
1651 ENUMX
1652 BFD_RELOC_16
1653 ENUMX
1654 BFD_RELOC_14
1655 ENUMX
1656 BFD_RELOC_8
1657 ENUMDOC
1658 Basic absolute relocations of N bits.
1659
1660 ENUM
1661 BFD_RELOC_64_PCREL
1662 ENUMX
1663 BFD_RELOC_32_PCREL
1664 ENUMX
1665 BFD_RELOC_24_PCREL
1666 ENUMX
1667 BFD_RELOC_16_PCREL
1668 ENUMX
1669 BFD_RELOC_12_PCREL
1670 ENUMX
1671 BFD_RELOC_8_PCREL
1672 ENUMDOC
1673 PC-relative relocations. Sometimes these are relative to the address
1674 of the relocation itself; sometimes they are relative to the start of
1675 the section containing the relocation. It depends on the specific target.
1676
1677 The 24-bit relocation is used in some Intel 960 configurations.
1678
1679 ENUM
1680 BFD_RELOC_32_GOT_PCREL
1681 ENUMX
1682 BFD_RELOC_16_GOT_PCREL
1683 ENUMX
1684 BFD_RELOC_8_GOT_PCREL
1685 ENUMX
1686 BFD_RELOC_32_GOTOFF
1687 ENUMX
1688 BFD_RELOC_16_GOTOFF
1689 ENUMX
1690 BFD_RELOC_LO16_GOTOFF
1691 ENUMX
1692 BFD_RELOC_HI16_GOTOFF
1693 ENUMX
1694 BFD_RELOC_HI16_S_GOTOFF
1695 ENUMX
1696 BFD_RELOC_8_GOTOFF
1697 ENUMX
1698 BFD_RELOC_32_PLT_PCREL
1699 ENUMX
1700 BFD_RELOC_24_PLT_PCREL
1701 ENUMX
1702 BFD_RELOC_16_PLT_PCREL
1703 ENUMX
1704 BFD_RELOC_8_PLT_PCREL
1705 ENUMX
1706 BFD_RELOC_32_PLTOFF
1707 ENUMX
1708 BFD_RELOC_16_PLTOFF
1709 ENUMX
1710 BFD_RELOC_LO16_PLTOFF
1711 ENUMX
1712 BFD_RELOC_HI16_PLTOFF
1713 ENUMX
1714 BFD_RELOC_HI16_S_PLTOFF
1715 ENUMX
1716 BFD_RELOC_8_PLTOFF
1717 ENUMDOC
1718 For ELF.
1719
1720 ENUM
1721 BFD_RELOC_68K_GLOB_DAT
1722 ENUMX
1723 BFD_RELOC_68K_JMP_SLOT
1724 ENUMX
1725 BFD_RELOC_68K_RELATIVE
1726 ENUMDOC
1727 Relocations used by 68K ELF.
1728
1729 ENUM
1730 BFD_RELOC_32_BASEREL
1731 ENUMX
1732 BFD_RELOC_16_BASEREL
1733 ENUMX
1734 BFD_RELOC_LO16_BASEREL
1735 ENUMX
1736 BFD_RELOC_HI16_BASEREL
1737 ENUMX
1738 BFD_RELOC_HI16_S_BASEREL
1739 ENUMX
1740 BFD_RELOC_8_BASEREL
1741 ENUMX
1742 BFD_RELOC_RVA
1743 ENUMDOC
1744 Linkage-table relative.
1745
1746 ENUM
1747 BFD_RELOC_8_FFnn
1748 ENUMDOC
1749 Absolute 8-bit relocation, but used to form an address like 0xFFnn.
1750
1751 ENUM
1752 BFD_RELOC_32_PCREL_S2
1753 ENUMX
1754 BFD_RELOC_16_PCREL_S2
1755 ENUMX
1756 BFD_RELOC_23_PCREL_S2
1757 ENUMDOC
1758 These PC-relative relocations are stored as word displacements --
1759 i.e., byte displacements shifted right two bits. The 30-bit word
1760 displacement (<<32_PCREL_S2>> -- 32 bits, shifted 2) is used on the
1761 SPARC. (SPARC tools generally refer to this as <<WDISP30>>.) The
1762 signed 16-bit displacement is used on the MIPS, and the 23-bit
1763 displacement is used on the Alpha.
1764
1765 ENUM
1766 BFD_RELOC_HI22
1767 ENUMX
1768 BFD_RELOC_LO10
1769 ENUMDOC
1770 High 22 bits and low 10 bits of 32-bit value, placed into lower bits of
1771 the target word. These are used on the SPARC.
1772
1773 ENUM
1774 BFD_RELOC_GPREL16
1775 ENUMX
1776 BFD_RELOC_GPREL32
1777 ENUMDOC
1778 For systems that allocate a Global Pointer register, these are
1779 displacements off that register. These relocation types are
1780 handled specially, because the value the register will have is
1781 decided relatively late.
1782
1783
1784 ENUM
1785 BFD_RELOC_I960_CALLJ
1786 ENUMDOC
1787 Reloc types used for i960/b.out.
1788
1789 ENUM
1790 BFD_RELOC_NONE
1791 ENUMX
1792 BFD_RELOC_SPARC_WDISP22
1793 ENUMX
1794 BFD_RELOC_SPARC22
1795 ENUMX
1796 BFD_RELOC_SPARC13
1797 ENUMX
1798 BFD_RELOC_SPARC_GOT10
1799 ENUMX
1800 BFD_RELOC_SPARC_GOT13
1801 ENUMX
1802 BFD_RELOC_SPARC_GOT22
1803 ENUMX
1804 BFD_RELOC_SPARC_PC10
1805 ENUMX
1806 BFD_RELOC_SPARC_PC22
1807 ENUMX
1808 BFD_RELOC_SPARC_WPLT30
1809 ENUMX
1810 BFD_RELOC_SPARC_COPY
1811 ENUMX
1812 BFD_RELOC_SPARC_GLOB_DAT
1813 ENUMX
1814 BFD_RELOC_SPARC_JMP_SLOT
1815 ENUMX
1816 BFD_RELOC_SPARC_RELATIVE
1817 ENUMX
1818 BFD_RELOC_SPARC_UA32
1819 ENUMDOC
1820 SPARC ELF relocations. There is probably some overlap with other
1821 relocation types already defined.
1822
1823 ENUM
1824 BFD_RELOC_SPARC_BASE13
1825 ENUMX
1826 BFD_RELOC_SPARC_BASE22
1827 ENUMDOC
1828 I think these are specific to SPARC a.out (e.g., Sun 4).
1829
1830 ENUMEQ
1831 BFD_RELOC_SPARC_64
1832 BFD_RELOC_64
1833 ENUMX
1834 BFD_RELOC_SPARC_10
1835 ENUMX
1836 BFD_RELOC_SPARC_11
1837 ENUMX
1838 BFD_RELOC_SPARC_OLO10
1839 ENUMX
1840 BFD_RELOC_SPARC_HH22
1841 ENUMX
1842 BFD_RELOC_SPARC_HM10
1843 ENUMX
1844 BFD_RELOC_SPARC_LM22
1845 ENUMX
1846 BFD_RELOC_SPARC_PC_HH22
1847 ENUMX
1848 BFD_RELOC_SPARC_PC_HM10
1849 ENUMX
1850 BFD_RELOC_SPARC_PC_LM22
1851 ENUMX
1852 BFD_RELOC_SPARC_WDISP16
1853 ENUMX
1854 BFD_RELOC_SPARC_WDISP19
1855 ENUMX
1856 BFD_RELOC_SPARC_7
1857 ENUMX
1858 BFD_RELOC_SPARC_6
1859 ENUMX
1860 BFD_RELOC_SPARC_5
1861 ENUMEQX
1862 BFD_RELOC_SPARC_DISP64
1863 BFD_RELOC_64_PCREL
1864 ENUMX
1865 BFD_RELOC_SPARC_PLT64
1866 ENUMX
1867 BFD_RELOC_SPARC_HIX22
1868 ENUMX
1869 BFD_RELOC_SPARC_LOX10
1870 ENUMX
1871 BFD_RELOC_SPARC_H44
1872 ENUMX
1873 BFD_RELOC_SPARC_M44
1874 ENUMX
1875 BFD_RELOC_SPARC_L44
1876 ENUMX
1877 BFD_RELOC_SPARC_REGISTER
1878 ENUMDOC
1879 SPARC64 relocations
1880
1881 ENUM
1882 BFD_RELOC_SPARC_REV32
1883 ENUMDOC
1884 SPARC little endian relocation
1885
1886 ENUM
1887 BFD_RELOC_ALPHA_GPDISP_HI16
1888 ENUMDOC
1889 Alpha ECOFF and ELF relocations. Some of these treat the symbol or
1890 "addend" in some special way.
1891 For GPDISP_HI16 ("gpdisp") relocations, the symbol is ignored when
1892 writing; when reading, it will be the absolute section symbol. The
1893 addend is the displacement in bytes of the "lda" instruction from
1894 the "ldah" instruction (which is at the address of this reloc).
1895 ENUM
1896 BFD_RELOC_ALPHA_GPDISP_LO16
1897 ENUMDOC
1898 For GPDISP_LO16 ("ignore") relocations, the symbol is handled as
1899 with GPDISP_HI16 relocs. The addend is ignored when writing the
1900 relocations out, and is filled in with the file's GP value on
1901 reading, for convenience.
1902
1903 ENUM
1904 BFD_RELOC_ALPHA_GPDISP
1905 ENUMDOC
1906 The ELF GPDISP relocation is exactly the same as the GPDISP_HI16
1907 relocation except that there is no accompanying GPDISP_LO16
1908 relocation.
1909
1910 ENUM
1911 BFD_RELOC_ALPHA_LITERAL
1912 ENUMX
1913 BFD_RELOC_ALPHA_ELF_LITERAL
1914 ENUMX
1915 BFD_RELOC_ALPHA_LITUSE
1916 ENUMDOC
1917 The Alpha LITERAL/LITUSE relocs are produced by a symbol reference;
1918 the assembler turns it into a LDQ instruction to load the address of
1919 the symbol, and then fills in a register in the real instruction.
1920
1921 The LITERAL reloc, at the LDQ instruction, refers to the .lita
1922 section symbol. The addend is ignored when writing, but is filled
1923 in with the file's GP value on reading, for convenience, as with the
1924 GPDISP_LO16 reloc.
1925
1926 The ELF_LITERAL reloc is somewhere between 16_GOTOFF and GPDISP_LO16.
1927 It should refer to the symbol to be referenced, as with 16_GOTOFF,
1928 but it generates output not based on the position within the .got
1929 section, but relative to the GP value chosen for the file during the
1930 final link stage.
1931
1932 The LITUSE reloc, on the instruction using the loaded address, gives
1933 information to the linker that it might be able to use to optimize
1934 away some literal section references. The symbol is ignored (read
1935 as the absolute section symbol), and the "addend" indicates the type
1936 of instruction using the register:
1937 1 - "memory" fmt insn
1938 2 - byte-manipulation (byte offset reg)
1939 3 - jsr (target of branch)
1940
1941 The GNU linker currently doesn't do any of this optimizing.
1942
1943 ENUM
1944 BFD_RELOC_ALPHA_USER_LITERAL
1945 ENUMX
1946 BFD_RELOC_ALPHA_USER_LITUSE_BASE
1947 ENUMX
1948 BFD_RELOC_ALPHA_USER_LITUSE_BYTOFF
1949 ENUMX
1950 BFD_RELOC_ALPHA_USER_LITUSE_JSR
1951 ENUMX
1952 BFD_RELOC_ALPHA_USER_GPDISP
1953 ENUMX
1954 BFD_RELOC_ALPHA_USER_GPRELHIGH
1955 ENUMX
1956 BFD_RELOC_ALPHA_USER_GPRELLOW
1957 ENUMDOC
1958 The BFD_RELOC_ALPHA_USER_* relocations are used by the assembler to
1959 process the explicit !<reloc>!sequence relocations, and are mapped
1960 into the normal relocations at the end of processing.
1961
1962 ENUM
1963 BFD_RELOC_ALPHA_HINT
1964 ENUMDOC
1965 The HINT relocation indicates a value that should be filled into the
1966 "hint" field of a jmp/jsr/ret instruction, for possible branch-
1967 prediction logic which may be provided on some processors.
1968
1969 ENUM
1970 BFD_RELOC_ALPHA_LINKAGE
1971 ENUMDOC
1972 The LINKAGE relocation outputs a linkage pair in the object file,
1973 which is filled by the linker.
1974
1975 ENUM
1976 BFD_RELOC_ALPHA_CODEADDR
1977 ENUMDOC
1978 The CODEADDR relocation outputs a STO_CA in the object file,
1979 which is filled by the linker.
1980
1981 ENUM
1982 BFD_RELOC_MIPS_JMP
1983 ENUMDOC
1984 Bits 27..2 of the relocation address shifted right 2 bits;
1985 simple reloc otherwise.
1986
1987 ENUM
1988 BFD_RELOC_MIPS16_JMP
1989 ENUMDOC
1990 The MIPS16 jump instruction.
1991
1992 ENUM
1993 BFD_RELOC_MIPS16_GPREL
1994 ENUMDOC
1995 MIPS16 GP relative reloc.
1996
1997 ENUM
1998 BFD_RELOC_HI16
1999 ENUMDOC
2000 High 16 bits of 32-bit value; simple reloc.
2001 ENUM
2002 BFD_RELOC_HI16_S
2003 ENUMDOC
2004 High 16 bits of 32-bit value but the low 16 bits will be sign
2005 extended and added to form the final result. If the low 16
2006 bits form a negative number, we need to add one to the high value
2007 to compensate for the borrow when the low bits are added.
2008 ENUM
2009 BFD_RELOC_LO16
2010 ENUMDOC
2011 Low 16 bits.
2012 ENUM
2013 BFD_RELOC_PCREL_HI16_S
2014 ENUMDOC
2015 Like BFD_RELOC_HI16_S, but PC relative.
2016 ENUM
2017 BFD_RELOC_PCREL_LO16
2018 ENUMDOC
2019 Like BFD_RELOC_LO16, but PC relative.
2020
2021 ENUMEQ
2022 BFD_RELOC_MIPS_GPREL
2023 BFD_RELOC_GPREL16
2024 ENUMDOC
2025 Relocation relative to the global pointer.
2026
2027 ENUM
2028 BFD_RELOC_MIPS_LITERAL
2029 ENUMDOC
2030 Relocation against a MIPS literal section.
2031
2032 ENUM
2033 BFD_RELOC_MIPS_GOT16
2034 ENUMX
2035 BFD_RELOC_MIPS_CALL16
2036 ENUMEQX
2037 BFD_RELOC_MIPS_GPREL32
2038 BFD_RELOC_GPREL32
2039 ENUMX
2040 BFD_RELOC_MIPS_GOT_HI16
2041 ENUMX
2042 BFD_RELOC_MIPS_GOT_LO16
2043 ENUMX
2044 BFD_RELOC_MIPS_CALL_HI16
2045 ENUMX
2046 BFD_RELOC_MIPS_CALL_LO16
2047 ENUMX
2048 BFD_RELOC_MIPS_SUB
2049 ENUMX
2050 BFD_RELOC_MIPS_GOT_PAGE
2051 ENUMX
2052 BFD_RELOC_MIPS_GOT_OFST
2053 ENUMX
2054 BFD_RELOC_MIPS_GOT_DISP
2055 COMMENT
2056 ENUMDOC
2057 MIPS ELF relocations.
2058
2059 COMMENT
2060
2061 ENUM
2062 BFD_RELOC_386_GOT32
2063 ENUMX
2064 BFD_RELOC_386_PLT32
2065 ENUMX
2066 BFD_RELOC_386_COPY
2067 ENUMX
2068 BFD_RELOC_386_GLOB_DAT
2069 ENUMX
2070 BFD_RELOC_386_JUMP_SLOT
2071 ENUMX
2072 BFD_RELOC_386_RELATIVE
2073 ENUMX
2074 BFD_RELOC_386_GOTOFF
2075 ENUMX
2076 BFD_RELOC_386_GOTPC
2077 ENUMDOC
2078 i386/elf relocations
2079
2080 ENUM
2081 BFD_RELOC_NS32K_IMM_8
2082 ENUMX
2083 BFD_RELOC_NS32K_IMM_16
2084 ENUMX
2085 BFD_RELOC_NS32K_IMM_32
2086 ENUMX
2087 BFD_RELOC_NS32K_IMM_8_PCREL
2088 ENUMX
2089 BFD_RELOC_NS32K_IMM_16_PCREL
2090 ENUMX
2091 BFD_RELOC_NS32K_IMM_32_PCREL
2092 ENUMX
2093 BFD_RELOC_NS32K_DISP_8
2094 ENUMX
2095 BFD_RELOC_NS32K_DISP_16
2096 ENUMX
2097 BFD_RELOC_NS32K_DISP_32
2098 ENUMX
2099 BFD_RELOC_NS32K_DISP_8_PCREL
2100 ENUMX
2101 BFD_RELOC_NS32K_DISP_16_PCREL
2102 ENUMX
2103 BFD_RELOC_NS32K_DISP_32_PCREL
2104 ENUMDOC
2105 ns32k relocations
2106
2107 ENUM
2108 BFD_RELOC_PJ_CODE_HI16
2109 ENUMX
2110 BFD_RELOC_PJ_CODE_LO16
2111 ENUMX
2112 BFD_RELOC_PJ_CODE_DIR16
2113 ENUMX
2114 BFD_RELOC_PJ_CODE_DIR32
2115 ENUMX
2116 BFD_RELOC_PJ_CODE_REL16
2117 ENUMX
2118 BFD_RELOC_PJ_CODE_REL32
2119 ENUMDOC
2120 Picojava relocs. Not all of these appear in object files.
2121
2122 ENUM
2123 BFD_RELOC_PPC_B26
2124 ENUMX
2125 BFD_RELOC_PPC_BA26
2126 ENUMX
2127 BFD_RELOC_PPC_TOC16
2128 ENUMX
2129 BFD_RELOC_PPC_B16
2130 ENUMX
2131 BFD_RELOC_PPC_B16_BRTAKEN
2132 ENUMX
2133 BFD_RELOC_PPC_B16_BRNTAKEN
2134 ENUMX
2135 BFD_RELOC_PPC_BA16
2136 ENUMX
2137 BFD_RELOC_PPC_BA16_BRTAKEN
2138 ENUMX
2139 BFD_RELOC_PPC_BA16_BRNTAKEN
2140 ENUMX
2141 BFD_RELOC_PPC_COPY
2142 ENUMX
2143 BFD_RELOC_PPC_GLOB_DAT
2144 ENUMX
2145 BFD_RELOC_PPC_JMP_SLOT
2146 ENUMX
2147 BFD_RELOC_PPC_RELATIVE
2148 ENUMX
2149 BFD_RELOC_PPC_LOCAL24PC
2150 ENUMX
2151 BFD_RELOC_PPC_EMB_NADDR32
2152 ENUMX
2153 BFD_RELOC_PPC_EMB_NADDR16
2154 ENUMX
2155 BFD_RELOC_PPC_EMB_NADDR16_LO
2156 ENUMX
2157 BFD_RELOC_PPC_EMB_NADDR16_HI
2158 ENUMX
2159 BFD_RELOC_PPC_EMB_NADDR16_HA
2160 ENUMX
2161 BFD_RELOC_PPC_EMB_SDAI16
2162 ENUMX
2163 BFD_RELOC_PPC_EMB_SDA2I16
2164 ENUMX
2165 BFD_RELOC_PPC_EMB_SDA2REL
2166 ENUMX
2167 BFD_RELOC_PPC_EMB_SDA21
2168 ENUMX
2169 BFD_RELOC_PPC_EMB_MRKREF
2170 ENUMX
2171 BFD_RELOC_PPC_EMB_RELSEC16
2172 ENUMX
2173 BFD_RELOC_PPC_EMB_RELST_LO
2174 ENUMX
2175 BFD_RELOC_PPC_EMB_RELST_HI
2176 ENUMX
2177 BFD_RELOC_PPC_EMB_RELST_HA
2178 ENUMX
2179 BFD_RELOC_PPC_EMB_BIT_FLD
2180 ENUMX
2181 BFD_RELOC_PPC_EMB_RELSDA
2182 ENUMDOC
2183 Power(rs6000) and PowerPC relocations.
2184
2185 ENUM
2186 BFD_RELOC_I370_D12
2187 ENUMDOC
2188 IBM 370/390 relocations
2189
2190 ENUM
2191 BFD_RELOC_CTOR
2192 ENUMDOC
2193 The type of reloc used to build a contructor table - at the moment
2194 probably a 32 bit wide absolute relocation, but the target can choose.
2195 It generally does map to one of the other relocation types.
2196
2197 ENUM
2198 BFD_RELOC_ARM_PCREL_BRANCH
2199 ENUMDOC
2200 ARM 26 bit pc-relative branch. The lowest two bits must be zero and are
2201 not stored in the instruction.
2202 ENUM
2203 BFD_RELOC_ARM_PCREL_BLX
2204 ENUMDOC
2205 ARM 26 bit pc-relative branch. The lowest bit must be zero and is
2206 not stored in the instruction. The 2nd lowest bit comes from a 1 bit
2207 field in the instruction.
2208 ENUM
2209 BFD_RELOC_THUMB_PCREL_BLX
2210 ENUMDOC
2211 Thumb 22 bit pc-relative branch. The lowest bit must be zero and is
2212 not stored in the instruction. The 2nd lowest bit comes from a 1 bit
2213 field in the instruction.
2214 ENUM
2215 BFD_RELOC_ARM_IMMEDIATE
2216 ENUMX
2217 BFD_RELOC_ARM_ADRL_IMMEDIATE
2218 ENUMX
2219 BFD_RELOC_ARM_OFFSET_IMM
2220 ENUMX
2221 BFD_RELOC_ARM_SHIFT_IMM
2222 ENUMX
2223 BFD_RELOC_ARM_SWI
2224 ENUMX
2225 BFD_RELOC_ARM_MULTI
2226 ENUMX
2227 BFD_RELOC_ARM_CP_OFF_IMM
2228 ENUMX
2229 BFD_RELOC_ARM_ADR_IMM
2230 ENUMX
2231 BFD_RELOC_ARM_LDR_IMM
2232 ENUMX
2233 BFD_RELOC_ARM_LITERAL
2234 ENUMX
2235 BFD_RELOC_ARM_IN_POOL
2236 ENUMX
2237 BFD_RELOC_ARM_OFFSET_IMM8
2238 ENUMX
2239 BFD_RELOC_ARM_HWLITERAL
2240 ENUMX
2241 BFD_RELOC_ARM_THUMB_ADD
2242 ENUMX
2243 BFD_RELOC_ARM_THUMB_IMM
2244 ENUMX
2245 BFD_RELOC_ARM_THUMB_SHIFT
2246 ENUMX
2247 BFD_RELOC_ARM_THUMB_OFFSET
2248 ENUMX
2249 BFD_RELOC_ARM_GOT12
2250 ENUMX
2251 BFD_RELOC_ARM_GOT32
2252 ENUMX
2253 BFD_RELOC_ARM_JUMP_SLOT
2254 ENUMX
2255 BFD_RELOC_ARM_COPY
2256 ENUMX
2257 BFD_RELOC_ARM_GLOB_DAT
2258 ENUMX
2259 BFD_RELOC_ARM_PLT32
2260 ENUMX
2261 BFD_RELOC_ARM_RELATIVE
2262 ENUMX
2263 BFD_RELOC_ARM_GOTOFF
2264 ENUMX
2265 BFD_RELOC_ARM_GOTPC
2266 ENUMDOC
2267 These relocs are only used within the ARM assembler. They are not
2268 (at present) written to any object files.
2269
2270 ENUM
2271 BFD_RELOC_SH_PCDISP8BY2
2272 ENUMX
2273 BFD_RELOC_SH_PCDISP12BY2
2274 ENUMX
2275 BFD_RELOC_SH_IMM4
2276 ENUMX
2277 BFD_RELOC_SH_IMM4BY2
2278 ENUMX
2279 BFD_RELOC_SH_IMM4BY4
2280 ENUMX
2281 BFD_RELOC_SH_IMM8
2282 ENUMX
2283 BFD_RELOC_SH_IMM8BY2
2284 ENUMX
2285 BFD_RELOC_SH_IMM8BY4
2286 ENUMX
2287 BFD_RELOC_SH_PCRELIMM8BY2
2288 ENUMX
2289 BFD_RELOC_SH_PCRELIMM8BY4
2290 ENUMX
2291 BFD_RELOC_SH_SWITCH16
2292 ENUMX
2293 BFD_RELOC_SH_SWITCH32
2294 ENUMX
2295 BFD_RELOC_SH_USES
2296 ENUMX
2297 BFD_RELOC_SH_COUNT
2298 ENUMX
2299 BFD_RELOC_SH_ALIGN
2300 ENUMX
2301 BFD_RELOC_SH_CODE
2302 ENUMX
2303 BFD_RELOC_SH_DATA
2304 ENUMX
2305 BFD_RELOC_SH_LABEL
2306 ENUMX
2307 BFD_RELOC_SH_LOOP_START
2308 ENUMX
2309 BFD_RELOC_SH_LOOP_END
2310 ENUMDOC
2311 Hitachi SH relocs. Not all of these appear in object files.
2312
2313 ENUM
2314 BFD_RELOC_THUMB_PCREL_BRANCH9
2315 ENUMX
2316 BFD_RELOC_THUMB_PCREL_BRANCH12
2317 ENUMX
2318 BFD_RELOC_THUMB_PCREL_BRANCH23
2319 ENUMDOC
2320 Thumb 23-, 12- and 9-bit pc-relative branches. The lowest bit must
2321 be zero and is not stored in the instruction.
2322
2323 ENUM
2324 BFD_RELOC_ARC_B22_PCREL
2325 ENUMDOC
2326 Argonaut RISC Core (ARC) relocs.
2327 ARC 22 bit pc-relative branch. The lowest two bits must be zero and are
2328 not stored in the instruction. The high 20 bits are installed in bits 26
2329 through 7 of the instruction.
2330 ENUM
2331 BFD_RELOC_ARC_B26
2332 ENUMDOC
2333 ARC 26 bit absolute branch. The lowest two bits must be zero and are not
2334 stored in the instruction. The high 24 bits are installed in bits 23
2335 through 0.
2336
2337 ENUM
2338 BFD_RELOC_D10V_10_PCREL_R
2339 ENUMDOC
2340 Mitsubishi D10V relocs.
2341 This is a 10-bit reloc with the right 2 bits
2342 assumed to be 0.
2343 ENUM
2344 BFD_RELOC_D10V_10_PCREL_L
2345 ENUMDOC
2346 Mitsubishi D10V relocs.
2347 This is a 10-bit reloc with the right 2 bits
2348 assumed to be 0. This is the same as the previous reloc
2349 except it is in the left container, i.e.,
2350 shifted left 15 bits.
2351 ENUM
2352 BFD_RELOC_D10V_18
2353 ENUMDOC
2354 This is an 18-bit reloc with the right 2 bits
2355 assumed to be 0.
2356 ENUM
2357 BFD_RELOC_D10V_18_PCREL
2358 ENUMDOC
2359 This is an 18-bit reloc with the right 2 bits
2360 assumed to be 0.
2361
2362 ENUM
2363 BFD_RELOC_D30V_6
2364 ENUMDOC
2365 Mitsubishi D30V relocs.
2366 This is a 6-bit absolute reloc.
2367 ENUM
2368 BFD_RELOC_D30V_9_PCREL
2369 ENUMDOC
2370 This is a 6-bit pc-relative reloc with
2371 the right 3 bits assumed to be 0.
2372 ENUM
2373 BFD_RELOC_D30V_9_PCREL_R
2374 ENUMDOC
2375 This is a 6-bit pc-relative reloc with
2376 the right 3 bits assumed to be 0. Same
2377 as the previous reloc but on the right side
2378 of the container.
2379 ENUM
2380 BFD_RELOC_D30V_15
2381 ENUMDOC
2382 This is a 12-bit absolute reloc with the
2383 right 3 bitsassumed to be 0.
2384 ENUM
2385 BFD_RELOC_D30V_15_PCREL
2386 ENUMDOC
2387 This is a 12-bit pc-relative reloc with
2388 the right 3 bits assumed to be 0.
2389 ENUM
2390 BFD_RELOC_D30V_15_PCREL_R
2391 ENUMDOC
2392 This is a 12-bit pc-relative reloc with
2393 the right 3 bits assumed to be 0. Same
2394 as the previous reloc but on the right side
2395 of the container.
2396 ENUM
2397 BFD_RELOC_D30V_21
2398 ENUMDOC
2399 This is an 18-bit absolute reloc with
2400 the right 3 bits assumed to be 0.
2401 ENUM
2402 BFD_RELOC_D30V_21_PCREL
2403 ENUMDOC
2404 This is an 18-bit pc-relative reloc with
2405 the right 3 bits assumed to be 0.
2406 ENUM
2407 BFD_RELOC_D30V_21_PCREL_R
2408 ENUMDOC
2409 This is an 18-bit pc-relative reloc with
2410 the right 3 bits assumed to be 0. Same
2411 as the previous reloc but on the right side
2412 of the container.
2413 ENUM
2414 BFD_RELOC_D30V_32
2415 ENUMDOC
2416 This is a 32-bit absolute reloc.
2417 ENUM
2418 BFD_RELOC_D30V_32_PCREL
2419 ENUMDOC
2420 This is a 32-bit pc-relative reloc.
2421
2422 ENUM
2423 BFD_RELOC_M32R_24
2424 ENUMDOC
2425 Mitsubishi M32R relocs.
2426 This is a 24 bit absolute address.
2427 ENUM
2428 BFD_RELOC_M32R_10_PCREL
2429 ENUMDOC
2430 This is a 10-bit pc-relative reloc with the right 2 bits assumed to be 0.
2431 ENUM
2432 BFD_RELOC_M32R_18_PCREL
2433 ENUMDOC
2434 This is an 18-bit reloc with the right 2 bits assumed to be 0.
2435 ENUM
2436 BFD_RELOC_M32R_26_PCREL
2437 ENUMDOC
2438 This is a 26-bit reloc with the right 2 bits assumed to be 0.
2439 ENUM
2440 BFD_RELOC_M32R_HI16_ULO
2441 ENUMDOC
2442 This is a 16-bit reloc containing the high 16 bits of an address
2443 used when the lower 16 bits are treated as unsigned.
2444 ENUM
2445 BFD_RELOC_M32R_HI16_SLO
2446 ENUMDOC
2447 This is a 16-bit reloc containing the high 16 bits of an address
2448 used when the lower 16 bits are treated as signed.
2449 ENUM
2450 BFD_RELOC_M32R_LO16
2451 ENUMDOC
2452 This is a 16-bit reloc containing the lower 16 bits of an address.
2453 ENUM
2454 BFD_RELOC_M32R_SDA16
2455 ENUMDOC
2456 This is a 16-bit reloc containing the small data area offset for use in
2457 add3, load, and store instructions.
2458
2459 ENUM
2460 BFD_RELOC_V850_9_PCREL
2461 ENUMDOC
2462 This is a 9-bit reloc
2463 ENUM
2464 BFD_RELOC_V850_22_PCREL
2465 ENUMDOC
2466 This is a 22-bit reloc
2467
2468 ENUM
2469 BFD_RELOC_V850_SDA_16_16_OFFSET
2470 ENUMDOC
2471 This is a 16 bit offset from the short data area pointer.
2472 ENUM
2473 BFD_RELOC_V850_SDA_15_16_OFFSET
2474 ENUMDOC
2475 This is a 16 bit offset (of which only 15 bits are used) from the
2476 short data area pointer.
2477 ENUM
2478 BFD_RELOC_V850_ZDA_16_16_OFFSET
2479 ENUMDOC
2480 This is a 16 bit offset from the zero data area pointer.
2481 ENUM
2482 BFD_RELOC_V850_ZDA_15_16_OFFSET
2483 ENUMDOC
2484 This is a 16 bit offset (of which only 15 bits are used) from the
2485 zero data area pointer.
2486 ENUM
2487 BFD_RELOC_V850_TDA_6_8_OFFSET
2488 ENUMDOC
2489 This is an 8 bit offset (of which only 6 bits are used) from the
2490 tiny data area pointer.
2491 ENUM
2492 BFD_RELOC_V850_TDA_7_8_OFFSET
2493 ENUMDOC
2494 This is an 8bit offset (of which only 7 bits are used) from the tiny
2495 data area pointer.
2496 ENUM
2497 BFD_RELOC_V850_TDA_7_7_OFFSET
2498 ENUMDOC
2499 This is a 7 bit offset from the tiny data area pointer.
2500 ENUM
2501 BFD_RELOC_V850_TDA_16_16_OFFSET
2502 ENUMDOC
2503 This is a 16 bit offset from the tiny data area pointer.
2504 COMMENT
2505 ENUM
2506 BFD_RELOC_V850_TDA_4_5_OFFSET
2507 ENUMDOC
2508 This is a 5 bit offset (of which only 4 bits are used) from the tiny
2509 data area pointer.
2510 ENUM
2511 BFD_RELOC_V850_TDA_4_4_OFFSET
2512 ENUMDOC
2513 This is a 4 bit offset from the tiny data area pointer.
2514 ENUM
2515 BFD_RELOC_V850_SDA_16_16_SPLIT_OFFSET
2516 ENUMDOC
2517 This is a 16 bit offset from the short data area pointer, with the
2518 bits placed non-contigously in the instruction.
2519 ENUM
2520 BFD_RELOC_V850_ZDA_16_16_SPLIT_OFFSET
2521 ENUMDOC
2522 This is a 16 bit offset from the zero data area pointer, with the
2523 bits placed non-contigously in the instruction.
2524 ENUM
2525 BFD_RELOC_V850_CALLT_6_7_OFFSET
2526 ENUMDOC
2527 This is a 6 bit offset from the call table base pointer.
2528 ENUM
2529 BFD_RELOC_V850_CALLT_16_16_OFFSET
2530 ENUMDOC
2531 This is a 16 bit offset from the call table base pointer.
2532 COMMENT
2533
2534 ENUM
2535 BFD_RELOC_MN10300_32_PCREL
2536 ENUMDOC
2537 This is a 32bit pcrel reloc for the mn10300, offset by two bytes in the
2538 instruction.
2539 ENUM
2540 BFD_RELOC_MN10300_16_PCREL
2541 ENUMDOC
2542 This is a 16bit pcrel reloc for the mn10300, offset by two bytes in the
2543 instruction.
2544
2545 ENUM
2546 BFD_RELOC_TIC30_LDP
2547 ENUMDOC
2548 This is a 8bit DP reloc for the tms320c30, where the most
2549 significant 8 bits of a 24 bit word are placed into the least
2550 significant 8 bits of the opcode.
2551
2552 ENUM
2553 BFD_RELOC_TIC54X_PARTLS7
2554 ENUMDOC
2555 This is a 7bit reloc for the tms320c54x, where the least
2556 significant 7 bits of a 16 bit word are placed into the least
2557 significant 7 bits of the opcode.
2558
2559 ENUM
2560 BFD_RELOC_TIC54X_PARTMS9
2561 ENUMDOC
2562 This is a 9bit DP reloc for the tms320c54x, where the most
2563 significant 9 bits of a 16 bit word are placed into the least
2564 significant 9 bits of the opcode.
2565
2566 ENUM
2567 BFD_RELOC_TIC54X_23
2568 ENUMDOC
2569 This is an extended address 23-bit reloc for the tms320c54x.
2570
2571 ENUM
2572 BFD_RELOC_TIC54X_16_OF_23
2573 ENUMDOC
2574 This is a 16-bit reloc for the tms320c54x, where the least
2575 significant 16 bits of a 23-bit extended address are placed into
2576 the opcode.
2577
2578 ENUM
2579 BFD_RELOC_TIC54X_MS7_OF_23
2580 ENUMDOC
2581 This is a reloc for the tms320c54x, where the most
2582 significant 7 bits of a 23-bit extended address are placed into
2583 the opcode.
2584
2585 ENUM
2586 BFD_RELOC_FR30_48
2587 ENUMDOC
2588 This is a 48 bit reloc for the FR30 that stores 32 bits.
2589 ENUM
2590 BFD_RELOC_FR30_20
2591 ENUMDOC
2592 This is a 32 bit reloc for the FR30 that stores 20 bits split up into
2593 two sections.
2594 ENUM
2595 BFD_RELOC_FR30_6_IN_4
2596 ENUMDOC
2597 This is a 16 bit reloc for the FR30 that stores a 6 bit word offset in
2598 4 bits.
2599 ENUM
2600 BFD_RELOC_FR30_8_IN_8
2601 ENUMDOC
2602 This is a 16 bit reloc for the FR30 that stores an 8 bit byte offset
2603 into 8 bits.
2604 ENUM
2605 BFD_RELOC_FR30_9_IN_8
2606 ENUMDOC
2607 This is a 16 bit reloc for the FR30 that stores a 9 bit short offset
2608 into 8 bits.
2609 ENUM
2610 BFD_RELOC_FR30_10_IN_8
2611 ENUMDOC
2612 This is a 16 bit reloc for the FR30 that stores a 10 bit word offset
2613 into 8 bits.
2614 ENUM
2615 BFD_RELOC_FR30_9_PCREL
2616 ENUMDOC
2617 This is a 16 bit reloc for the FR30 that stores a 9 bit pc relative
2618 short offset into 8 bits.
2619 ENUM
2620 BFD_RELOC_FR30_12_PCREL
2621 ENUMDOC
2622 This is a 16 bit reloc for the FR30 that stores a 12 bit pc relative
2623 short offset into 11 bits.
2624
2625 ENUM
2626 BFD_RELOC_MCORE_PCREL_IMM8BY4
2627 ENUMX
2628 BFD_RELOC_MCORE_PCREL_IMM11BY2
2629 ENUMX
2630 BFD_RELOC_MCORE_PCREL_IMM4BY2
2631 ENUMX
2632 BFD_RELOC_MCORE_PCREL_32
2633 ENUMX
2634 BFD_RELOC_MCORE_PCREL_JSR_IMM11BY2
2635 ENUMX
2636 BFD_RELOC_MCORE_RVA
2637 ENUMDOC
2638 Motorola Mcore relocations.
2639
2640 ENUM
2641 BFD_RELOC_AVR_7_PCREL
2642 ENUMDOC
2643 This is a 16 bit reloc for the AVR that stores 8 bit pc relative
2644 short offset into 7 bits.
2645 ENUM
2646 BFD_RELOC_AVR_13_PCREL
2647 ENUMDOC
2648 This is a 16 bit reloc for the AVR that stores 13 bit pc relative
2649 short offset into 12 bits.
2650 ENUM
2651 BFD_RELOC_AVR_16_PM
2652 ENUMDOC
2653 This is a 16 bit reloc for the AVR that stores 17 bit value (usually
2654 program memory address) into 16 bits.
2655 ENUM
2656 BFD_RELOC_AVR_LO8_LDI
2657 ENUMDOC
2658 This is a 16 bit reloc for the AVR that stores 8 bit value (usually
2659 data memory address) into 8 bit immediate value of LDI insn.
2660 ENUM
2661 BFD_RELOC_AVR_HI8_LDI
2662 ENUMDOC
2663 This is a 16 bit reloc for the AVR that stores 8 bit value (high 8 bit
2664 of data memory address) into 8 bit immediate value of LDI insn.
2665 ENUM
2666 BFD_RELOC_AVR_HH8_LDI
2667 ENUMDOC
2668 This is a 16 bit reloc for the AVR that stores 8 bit value (most high 8 bit
2669 of program memory address) into 8 bit immediate value of LDI insn.
2670 ENUM
2671 BFD_RELOC_AVR_LO8_LDI_NEG
2672 ENUMDOC
2673 This is a 16 bit reloc for the AVR that stores negated 8 bit value
2674 (usually data memory address) into 8 bit immediate value of SUBI insn.
2675 ENUM
2676 BFD_RELOC_AVR_HI8_LDI_NEG
2677 ENUMDOC
2678 This is a 16 bit reloc for the AVR that stores negated 8 bit value
2679 (high 8 bit of data memory address) into 8 bit immediate value of
2680 SUBI insn.
2681 ENUM
2682 BFD_RELOC_AVR_HH8_LDI_NEG
2683 ENUMDOC
2684 This is a 16 bit reloc for the AVR that stores negated 8 bit value
2685 (most high 8 bit of program memory address) into 8 bit immediate value
2686 of LDI or SUBI insn.
2687 ENUM
2688 BFD_RELOC_AVR_LO8_LDI_PM
2689 ENUMDOC
2690 This is a 16 bit reloc for the AVR that stores 8 bit value (usually
2691 command address) into 8 bit immediate value of LDI insn.
2692 ENUM
2693 BFD_RELOC_AVR_HI8_LDI_PM
2694 ENUMDOC
2695 This is a 16 bit reloc for the AVR that stores 8 bit value (high 8 bit
2696 of command address) into 8 bit immediate value of LDI insn.
2697 ENUM
2698 BFD_RELOC_AVR_HH8_LDI_PM
2699 ENUMDOC
2700 This is a 16 bit reloc for the AVR that stores 8 bit value (most high 8 bit
2701 of command address) into 8 bit immediate value of LDI insn.
2702 ENUM
2703 BFD_RELOC_AVR_LO8_LDI_PM_NEG
2704 ENUMDOC
2705 This is a 16 bit reloc for the AVR that stores negated 8 bit value
2706 (usually command address) into 8 bit immediate value of SUBI insn.
2707 ENUM
2708 BFD_RELOC_AVR_HI8_LDI_PM_NEG
2709 ENUMDOC
2710 This is a 16 bit reloc for the AVR that stores negated 8 bit value
2711 (high 8 bit of 16 bit command address) into 8 bit immediate value
2712 of SUBI insn.
2713 ENUM
2714 BFD_RELOC_AVR_HH8_LDI_PM_NEG
2715 ENUMDOC
2716 This is a 16 bit reloc for the AVR that stores negated 8 bit value
2717 (high 6 bit of 22 bit command address) into 8 bit immediate
2718 value of SUBI insn.
2719 ENUM
2720 BFD_RELOC_AVR_CALL
2721 ENUMDOC
2722 This is a 32 bit reloc for the AVR that stores 23 bit value
2723 into 22 bits.
2724
2725 ENUM
2726 BFD_RELOC_VTABLE_INHERIT
2727 ENUMX
2728 BFD_RELOC_VTABLE_ENTRY
2729 ENUMDOC
2730 These two relocations are used by the linker to determine which of
2731 the entries in a C++ virtual function table are actually used. When
2732 the --gc-sections option is given, the linker will zero out the entries
2733 that are not used, so that the code for those functions need not be
2734 included in the output.
2735
2736 VTABLE_INHERIT is a zero-space relocation used to describe to the
2737 linker the inheritence tree of a C++ virtual function table. The
2738 relocation's symbol should be the parent class' vtable, and the
2739 relocation should be located at the child vtable.
2740
2741 VTABLE_ENTRY is a zero-space relocation that describes the use of a
2742 virtual function table entry. The reloc's symbol should refer to the
2743 table of the class mentioned in the code. Off of that base, an offset
2744 describes the entry that is being used. For Rela hosts, this offset
2745 is stored in the reloc's addend. For Rel hosts, we are forced to put
2746 this offset in the reloc's section offset.
2747
2748 ENUM
2749 BFD_RELOC_IA64_IMM14
2750 ENUMX
2751 BFD_RELOC_IA64_IMM22
2752 ENUMX
2753 BFD_RELOC_IA64_IMM64
2754 ENUMX
2755 BFD_RELOC_IA64_DIR32MSB
2756 ENUMX
2757 BFD_RELOC_IA64_DIR32LSB
2758 ENUMX
2759 BFD_RELOC_IA64_DIR64MSB
2760 ENUMX
2761 BFD_RELOC_IA64_DIR64LSB
2762 ENUMX
2763 BFD_RELOC_IA64_GPREL22
2764 ENUMX
2765 BFD_RELOC_IA64_GPREL64I
2766 ENUMX
2767 BFD_RELOC_IA64_GPREL32MSB
2768 ENUMX
2769 BFD_RELOC_IA64_GPREL32LSB
2770 ENUMX
2771 BFD_RELOC_IA64_GPREL64MSB
2772 ENUMX
2773 BFD_RELOC_IA64_GPREL64LSB
2774 ENUMX
2775 BFD_RELOC_IA64_LTOFF22
2776 ENUMX
2777 BFD_RELOC_IA64_LTOFF64I
2778 ENUMX
2779 BFD_RELOC_IA64_PLTOFF22
2780 ENUMX
2781 BFD_RELOC_IA64_PLTOFF64I
2782 ENUMX
2783 BFD_RELOC_IA64_PLTOFF64MSB
2784 ENUMX
2785 BFD_RELOC_IA64_PLTOFF64LSB
2786 ENUMX
2787 BFD_RELOC_IA64_FPTR64I
2788 ENUMX
2789 BFD_RELOC_IA64_FPTR32MSB
2790 ENUMX
2791 BFD_RELOC_IA64_FPTR32LSB
2792 ENUMX
2793 BFD_RELOC_IA64_FPTR64MSB
2794 ENUMX
2795 BFD_RELOC_IA64_FPTR64LSB
2796 ENUMX
2797 BFD_RELOC_IA64_PCREL21B
2798 ENUMX
2799 BFD_RELOC_IA64_PCREL21BI
2800 ENUMX
2801 BFD_RELOC_IA64_PCREL21M
2802 ENUMX
2803 BFD_RELOC_IA64_PCREL21F
2804 ENUMX
2805 BFD_RELOC_IA64_PCREL22
2806 ENUMX
2807 BFD_RELOC_IA64_PCREL60B
2808 ENUMX
2809 BFD_RELOC_IA64_PCREL64I
2810 ENUMX
2811 BFD_RELOC_IA64_PCREL32MSB
2812 ENUMX
2813 BFD_RELOC_IA64_PCREL32LSB
2814 ENUMX
2815 BFD_RELOC_IA64_PCREL64MSB
2816 ENUMX
2817 BFD_RELOC_IA64_PCREL64LSB
2818 ENUMX
2819 BFD_RELOC_IA64_LTOFF_FPTR22
2820 ENUMX
2821 BFD_RELOC_IA64_LTOFF_FPTR64I
2822 ENUMX
2823 BFD_RELOC_IA64_LTOFF_FPTR64MSB
2824 ENUMX
2825 BFD_RELOC_IA64_LTOFF_FPTR64LSB
2826 ENUMX
2827 BFD_RELOC_IA64_SEGBASE
2828 ENUMX
2829 BFD_RELOC_IA64_SEGREL32MSB
2830 ENUMX
2831 BFD_RELOC_IA64_SEGREL32LSB
2832 ENUMX
2833 BFD_RELOC_IA64_SEGREL64MSB
2834 ENUMX
2835 BFD_RELOC_IA64_SEGREL64LSB
2836 ENUMX
2837 BFD_RELOC_IA64_SECREL32MSB
2838 ENUMX
2839 BFD_RELOC_IA64_SECREL32LSB
2840 ENUMX
2841 BFD_RELOC_IA64_SECREL64MSB
2842 ENUMX
2843 BFD_RELOC_IA64_SECREL64LSB
2844 ENUMX
2845 BFD_RELOC_IA64_REL32MSB
2846 ENUMX
2847 BFD_RELOC_IA64_REL32LSB
2848 ENUMX
2849 BFD_RELOC_IA64_REL64MSB
2850 ENUMX
2851 BFD_RELOC_IA64_REL64LSB
2852 ENUMX
2853 BFD_RELOC_IA64_LTV32MSB
2854 ENUMX
2855 BFD_RELOC_IA64_LTV32LSB
2856 ENUMX
2857 BFD_RELOC_IA64_LTV64MSB
2858 ENUMX
2859 BFD_RELOC_IA64_LTV64LSB
2860 ENUMX
2861 BFD_RELOC_IA64_IPLTMSB
2862 ENUMX
2863 BFD_RELOC_IA64_IPLTLSB
2864 ENUMX
2865 BFD_RELOC_IA64_EPLTMSB
2866 ENUMX
2867 BFD_RELOC_IA64_EPLTLSB
2868 ENUMX
2869 BFD_RELOC_IA64_COPY
2870 ENUMX
2871 BFD_RELOC_IA64_TPREL22
2872 ENUMX
2873 BFD_RELOC_IA64_TPREL64MSB
2874 ENUMX
2875 BFD_RELOC_IA64_TPREL64LSB
2876 ENUMX
2877 BFD_RELOC_IA64_LTOFF_TP22
2878 ENUMX
2879 BFD_RELOC_IA64_LTOFF22X
2880 ENUMX
2881 BFD_RELOC_IA64_LDXMOV
2882 ENUMDOC
2883 Intel IA64 Relocations.
2884
2885 ENUM
2886 BFD_RELOC_M68HC11_HI8
2887 ENUMDOC
2888 Motorola 68HC11 reloc.
2889 This is the 8 bits high part of an absolute address.
2890 ENUM
2891 BFD_RELOC_M68HC11_LO8
2892 ENUMDOC
2893 Motorola 68HC11 reloc.
2894 This is the 8 bits low part of an absolute address.
2895 ENUM
2896 BFD_RELOC_M68HC11_3B
2897 ENUMDOC
2898 Motorola 68HC11 reloc.
2899 This is the 3 bits of a value.
2900
2901 ENDSENUM
2902 BFD_RELOC_UNUSED
2903 CODE_FRAGMENT
2904 .
2905 .typedef enum bfd_reloc_code_real bfd_reloc_code_real_type;
2906 */
2907
2908
2909 /*
2910 FUNCTION
2911 bfd_reloc_type_lookup
2912
2913 SYNOPSIS
2914 reloc_howto_type *
2915 bfd_reloc_type_lookup (bfd *abfd, bfd_reloc_code_real_type code);
2916
2917 DESCRIPTION
2918 Return a pointer to a howto structure which, when
2919 invoked, will perform the relocation @var{code} on data from the
2920 architecture noted.
2921
2922 */
2923
2924
2925 reloc_howto_type *
2926 bfd_reloc_type_lookup (abfd, code)
2927 bfd *abfd;
2928 bfd_reloc_code_real_type code;
2929 {
2930 return BFD_SEND (abfd, reloc_type_lookup, (abfd, code));
2931 }
2932
2933 static reloc_howto_type bfd_howto_32 =
2934 HOWTO (0, 00, 2, 32, false, 0, complain_overflow_bitfield, 0, "VRT32", false, 0xffffffff, 0xffffffff, true);
2935
2936
2937 /*
2938 INTERNAL_FUNCTION
2939 bfd_default_reloc_type_lookup
2940
2941 SYNOPSIS
2942 reloc_howto_type *bfd_default_reloc_type_lookup
2943 (bfd *abfd, bfd_reloc_code_real_type code);
2944
2945 DESCRIPTION
2946 Provides a default relocation lookup routine for any architecture.
2947
2948
2949 */
2950
2951 reloc_howto_type *
2952 bfd_default_reloc_type_lookup (abfd, code)
2953 bfd *abfd;
2954 bfd_reloc_code_real_type code;
2955 {
2956 switch (code)
2957 {
2958 case BFD_RELOC_CTOR:
2959 /* The type of reloc used in a ctor, which will be as wide as the
2960 address - so either a 64, 32, or 16 bitter. */
2961 switch (bfd_get_arch_info (abfd)->bits_per_address)
2962 {
2963 case 64:
2964 BFD_FAIL ();
2965 case 32:
2966 return &bfd_howto_32;
2967 case 16:
2968 BFD_FAIL ();
2969 default:
2970 BFD_FAIL ();
2971 }
2972 default:
2973 BFD_FAIL ();
2974 }
2975 return (reloc_howto_type *) NULL;
2976 }
2977
2978 /*
2979 FUNCTION
2980 bfd_get_reloc_code_name
2981
2982 SYNOPSIS
2983 const char *bfd_get_reloc_code_name (bfd_reloc_code_real_type code);
2984
2985 DESCRIPTION
2986 Provides a printable name for the supplied relocation code.
2987 Useful mainly for printing error messages.
2988 */
2989
2990 const char *
2991 bfd_get_reloc_code_name (code)
2992 bfd_reloc_code_real_type code;
2993 {
2994 if (code > BFD_RELOC_UNUSED)
2995 return 0;
2996 return bfd_reloc_code_real_names[(int)code];
2997 }
2998
2999 /*
3000 INTERNAL_FUNCTION
3001 bfd_generic_relax_section
3002
3003 SYNOPSIS
3004 boolean bfd_generic_relax_section
3005 (bfd *abfd,
3006 asection *section,
3007 struct bfd_link_info *,
3008 boolean *);
3009
3010 DESCRIPTION
3011 Provides default handling for relaxing for back ends which
3012 don't do relaxing -- i.e., does nothing.
3013 */
3014
3015 /*ARGSUSED*/
3016 boolean
3017 bfd_generic_relax_section (abfd, section, link_info, again)
3018 bfd *abfd ATTRIBUTE_UNUSED;
3019 asection *section ATTRIBUTE_UNUSED;
3020 struct bfd_link_info *link_info ATTRIBUTE_UNUSED;
3021 boolean *again;
3022 {
3023 *again = false;
3024 return true;
3025 }
3026
3027 /*
3028 INTERNAL_FUNCTION
3029 bfd_generic_gc_sections
3030
3031 SYNOPSIS
3032 boolean bfd_generic_gc_sections
3033 (bfd *, struct bfd_link_info *);
3034
3035 DESCRIPTION
3036 Provides default handling for relaxing for back ends which
3037 don't do section gc -- i.e., does nothing.
3038 */
3039
3040 /*ARGSUSED*/
3041 boolean
3042 bfd_generic_gc_sections (abfd, link_info)
3043 bfd *abfd ATTRIBUTE_UNUSED;
3044 struct bfd_link_info *link_info ATTRIBUTE_UNUSED;
3045 {
3046 return true;
3047 }
3048
3049 /*
3050 INTERNAL_FUNCTION
3051 bfd_generic_get_relocated_section_contents
3052
3053 SYNOPSIS
3054 bfd_byte *
3055 bfd_generic_get_relocated_section_contents (bfd *abfd,
3056 struct bfd_link_info *link_info,
3057 struct bfd_link_order *link_order,
3058 bfd_byte *data,
3059 boolean relocateable,
3060 asymbol **symbols);
3061
3062 DESCRIPTION
3063 Provides default handling of relocation effort for back ends
3064 which can't be bothered to do it efficiently.
3065
3066 */
3067
3068 bfd_byte *
3069 bfd_generic_get_relocated_section_contents (abfd, link_info, link_order, data,
3070 relocateable, symbols)
3071 bfd *abfd;
3072 struct bfd_link_info *link_info;
3073 struct bfd_link_order *link_order;
3074 bfd_byte *data;
3075 boolean relocateable;
3076 asymbol **symbols;
3077 {
3078 /* Get enough memory to hold the stuff */
3079 bfd *input_bfd = link_order->u.indirect.section->owner;
3080 asection *input_section = link_order->u.indirect.section;
3081
3082 long reloc_size = bfd_get_reloc_upper_bound (input_bfd, input_section);
3083 arelent **reloc_vector = NULL;
3084 long reloc_count;
3085
3086 if (reloc_size < 0)
3087 goto error_return;
3088
3089 reloc_vector = (arelent **) bfd_malloc ((size_t) reloc_size);
3090 if (reloc_vector == NULL && reloc_size != 0)
3091 goto error_return;
3092
3093 /* read in the section */
3094 if (!bfd_get_section_contents (input_bfd,
3095 input_section,
3096 (PTR) data,
3097 0,
3098 input_section->_raw_size))
3099 goto error_return;
3100
3101 /* We're not relaxing the section, so just copy the size info */
3102 input_section->_cooked_size = input_section->_raw_size;
3103 input_section->reloc_done = true;
3104
3105 reloc_count = bfd_canonicalize_reloc (input_bfd,
3106 input_section,
3107 reloc_vector,
3108 symbols);
3109 if (reloc_count < 0)
3110 goto error_return;
3111
3112 if (reloc_count > 0)
3113 {
3114 arelent **parent;
3115 for (parent = reloc_vector; *parent != (arelent *) NULL;
3116 parent++)
3117 {
3118 char *error_message = (char *) NULL;
3119 bfd_reloc_status_type r =
3120 bfd_perform_relocation (input_bfd,
3121 *parent,
3122 (PTR) data,
3123 input_section,
3124 relocateable ? abfd : (bfd *) NULL,
3125 &error_message);
3126
3127 if (relocateable)
3128 {
3129 asection *os = input_section->output_section;
3130
3131 /* A partial link, so keep the relocs */
3132 os->orelocation[os->reloc_count] = *parent;
3133 os->reloc_count++;
3134 }
3135
3136 if (r != bfd_reloc_ok)
3137 {
3138 switch (r)
3139 {
3140 case bfd_reloc_undefined:
3141 if (!((*link_info->callbacks->undefined_symbol)
3142 (link_info, bfd_asymbol_name (*(*parent)->sym_ptr_ptr),
3143 input_bfd, input_section, (*parent)->address,
3144 true)))
3145 goto error_return;
3146 break;
3147 case bfd_reloc_dangerous:
3148 BFD_ASSERT (error_message != (char *) NULL);
3149 if (!((*link_info->callbacks->reloc_dangerous)
3150 (link_info, error_message, input_bfd, input_section,
3151 (*parent)->address)))
3152 goto error_return;
3153 break;
3154 case bfd_reloc_overflow:
3155 if (!((*link_info->callbacks->reloc_overflow)
3156 (link_info, bfd_asymbol_name (*(*parent)->sym_ptr_ptr),
3157 (*parent)->howto->name, (*parent)->addend,
3158 input_bfd, input_section, (*parent)->address)))
3159 goto error_return;
3160 break;
3161 case bfd_reloc_outofrange:
3162 default:
3163 abort ();
3164 break;
3165 }
3166
3167 }
3168 }
3169 }
3170 if (reloc_vector != NULL)
3171 free (reloc_vector);
3172 return data;
3173
3174 error_return:
3175 if (reloc_vector != NULL)
3176 free (reloc_vector);
3177 return NULL;
3178 }
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