bfd/reloc.c

   1 /* BFD support for handling relocation entries.
   2    Copyright (C) 1990, 91, 92, 93, 94, 95, 96, 97, 98, 1999
   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-mass 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 .       {* When performing a partial link, some formats must modify the
 344 .          relocations rather than the data - this flag signals this.*}
 345 .  boolean partial_inplace;
 346 .
 347 .       {* The src_mask selects which parts of the read in data
 348 .          are to be used in the relocation sum.  E.g., if this was an 8 bit
 349 .          bit of data which we read and relocated, this would be
 350 .          0x000000ff. When we have relocs which have an addend, such as
 351 .          sun4 extended relocs, the value in the offset part of a
 352 .          relocating field is garbage so we never use it. In this case
 353 .          the mask would be 0x00000000. *}
 354 .  bfd_vma src_mask;
 355 .
 356 .       {* The dst_mask selects which parts of the instruction are replaced
 357 .          into the instruction. In most cases src_mask == dst_mask,
 358 .          except in the above special case, where dst_mask would be
 359 .          0x000000ff, and src_mask would be 0x00000000.   *}
 360 .  bfd_vma dst_mask;
 361 .
 362 .       {* When some formats create PC relative instructions, they leave
 363 .          the value of the pc of the place being relocated in the offset
 364 .          slot of the instruction, so that a PC relative relocation can
 365 .          be made just by adding in an ordinary offset (e.g., sun3 a.out).
 366 .          Some formats leave the displacement part of an instruction
 367 .          empty (e.g., m88k bcs); this flag signals the fact.*}
 368 .  boolean pcrel_offset;
 369 .
 370 .};
 371
 372 */
 373
 374 /*
 375 FUNCTION
 376         The HOWTO Macro
 377
 378 DESCRIPTION
 379         The HOWTO define is horrible and will go away.
 380
 381
 382 .#define HOWTO(C, R,S,B, P, BI, O, SF, NAME, INPLACE, MASKSRC, MASKDST, PC) \
 383 .  {(unsigned)C,R,S,B, P, BI, O,SF,NAME,INPLACE,MASKSRC,MASKDST,PC}
 384
 385 DESCRIPTION
 386         And will be replaced with the totally magic way. But for the
 387         moment, we are compatible, so do it this way.
 388
 389
 390 .#define NEWHOWTO( FUNCTION, NAME,SIZE,REL,IN) HOWTO(0,0,SIZE,0,REL,0,complain_overflow_dont,FUNCTION, NAME,false,0,0,IN)
 391 .
 392 DESCRIPTION
 393         Helper routine to turn a symbol into a relocation value.
 394
 395 .#define HOWTO_PREPARE(relocation, symbol)      \
 396 .  {                                            \
 397 .  if (symbol != (asymbol *)NULL) {             \
 398 .    if (bfd_is_com_section (symbol->section)) { \
 399 .      relocation = 0;                          \
 400 .    }                                          \
 401 .    else {                                     \
 402 .      relocation = symbol->value;              \
 403 .    }                                          \
 404 .  }                                            \
 405 .}
 406
 407 */
 408
 409 /*
 410 FUNCTION
 411         bfd_get_reloc_size
 412
 413 SYNOPSIS
 414         unsigned int bfd_get_reloc_size (reloc_howto_type *);
 415
 416 DESCRIPTION
 417         For a reloc_howto_type that operates on a fixed number of bytes,
 418         this returns the number of bytes operated on.
 419  */
 420
 421 unsigned int
 422 bfd_get_reloc_size (howto)
 423      reloc_howto_type *howto;
 424 {
 425   switch (howto->size)
 426     {
 427     case 0: return 1;
 428     case 1: return 2;
 429     case 2: return 4;
 430     case 3: return 0;
 431     case 4: return 8;
 432     case 8: return 16;
 433     case -2: return 4;
 434     default: abort ();
 435     }
 436 }
 437
 438 /*
 439 TYPEDEF
 440         arelent_chain
 441
 442 DESCRIPTION
 443
 444         How relocs are tied together in an <<asection>>:
 445
 446 .typedef struct relent_chain {
 447 .  arelent relent;
 448 .  struct   relent_chain *next;
 449 .} arelent_chain;
 450
 451 */
 452
 453 /* N_ONES produces N one bits, without overflowing machine arithmetic.  */
 454 #define N_ONES(n) (((((bfd_vma) 1 << ((n) - 1)) - 1) << 1) | 1)
 455
 456 /*
 457 FUNCTION
 458         bfd_check_overflow
 459
 460 SYNOPSIS
 461         bfd_reloc_status_type
 462                 bfd_check_overflow
 463                         (enum complain_overflow how,
 464                          unsigned int bitsize,
 465                          unsigned int rightshift,
 466                          unsigned int addrsize,
 467                          bfd_vma relocation);
 468
 469 DESCRIPTION
 470         Perform overflow checking on @var{relocation} which has
 471         @var{bitsize} significant bits and will be shifted right by
 472         @var{rightshift} bits, on a machine with addresses containing
 473         @var{addrsize} significant bits.  The result is either of
 474         @code{bfd_reloc_ok} or @code{bfd_reloc_overflow}.
 475
 476 */
 477
 478 bfd_reloc_status_type
 479 bfd_check_overflow (how, bitsize, rightshift, addrsize, relocation)
 480      enum complain_overflow how;
 481      unsigned int bitsize;
 482      unsigned int rightshift;
 483      unsigned int addrsize;
 484      bfd_vma relocation;
 485 {
 486   bfd_vma fieldmask, addrmask, signmask, ss, a;
 487   bfd_reloc_status_type flag = bfd_reloc_ok;
 488
 489   a = relocation;
 490
 491   /* Note: BITSIZE should always be <= ADDRSIZE, but in case it's not,
 492      we'll be permissive: extra bits in the field mask will
 493      automatically extend the address mask for purposes of the
 494      overflow check.  */
 495   fieldmask = N_ONES (bitsize);
 496   addrmask = N_ONES (addrsize) | fieldmask;
 497
 498   switch (how)
 499     {
 500     case complain_overflow_dont:
 501       break;
 502
 503     case complain_overflow_signed:
 504       /* If any sign bits are set, all sign bits must be set.  That
 505          is, A must be a valid negative address after shifting.  */
 506       a = (a & addrmask) >> rightshift;
 507       signmask = ~ (fieldmask >> 1);
 508       ss = a & signmask;
 509       if (ss != 0 && ss != ((addrmask >> rightshift) & signmask))
 510         flag = bfd_reloc_overflow;
 511       break;
 512
 513     case complain_overflow_unsigned:
 514       /* We have an overflow if the address does not fit in the field.  */
 515       a = (a & addrmask) >> rightshift;
 516       if ((a & ~ fieldmask) != 0)
 517         flag = bfd_reloc_overflow;
 518       break;
 519
 520     case complain_overflow_bitfield:
 521       /* Bitfields are sometimes signed, sometimes unsigned.  We
 522          overflow if the value has some, but not all, bits set outside
 523          the field, or if it has any bits set outside the field but
 524          the sign bit is not set.  */
 525       a >>= rightshift;
 526       if ((a & ~ fieldmask) != 0)
 527         {
 528           signmask = (fieldmask >> 1) + 1;
 529           ss = (signmask << rightshift) - 1;
 530           if ((ss | relocation) != ~ (bfd_vma) 0)
 531             flag = bfd_reloc_overflow;
 532         }
 533       break;
 534
 535     default:
 536       abort ();
 537     }
 538
 539   return flag;
 540 }
 541
 542 /*
 543 FUNCTION
 544         bfd_perform_relocation
 545
 546 SYNOPSIS
 547         bfd_reloc_status_type
 548                 bfd_perform_relocation
 549                         (bfd *abfd,
 550                          arelent *reloc_entry,
 551                          PTR data,
 552                          asection *input_section,
 553                          bfd *output_bfd,
 554                          char **error_message);
 555
 556 DESCRIPTION
 557         If @var{output_bfd} is supplied to this function, the
 558         generated image will be relocatable; the relocations are
 559         copied to the output file after they have been changed to
 560         reflect the new state of the world. There are two ways of
 561         reflecting the results of partial linkage in an output file:
 562         by modifying the output data in place, and by modifying the
 563         relocation record.  Some native formats (e.g., basic a.out and
 564         basic coff) have no way of specifying an addend in the
 565         relocation type, so the addend has to go in the output data.
 566         This is no big deal since in these formats the output data
 567         slot will always be big enough for the addend. Complex reloc
 568         types with addends were invented to solve just this problem.
 569         The @var{error_message} argument is set to an error message if
 570         this return @code{bfd_reloc_dangerous}.
 571
 572 */
 573
 574
 575 bfd_reloc_status_type
 576 bfd_perform_relocation (abfd, reloc_entry, data, input_section, output_bfd,
 577                         error_message)
 578      bfd *abfd;
 579      arelent *reloc_entry;
 580      PTR data;
 581      asection *input_section;
 582      bfd *output_bfd;
 583      char **error_message;
 584 {
 585   bfd_vma relocation;
 586   bfd_reloc_status_type flag = bfd_reloc_ok;
 587   bfd_size_type addr = reloc_entry->address;
 588   bfd_vma output_base = 0;
 589   reloc_howto_type *howto = reloc_entry->howto;
 590   asection *reloc_target_output_section;
 591   asymbol *symbol;
 592
 593   symbol = *(reloc_entry->sym_ptr_ptr);
 594   if (bfd_is_abs_section (symbol->section)
 595       && output_bfd != (bfd *) NULL)
 596     {
 597       reloc_entry->address += input_section->output_offset;
 598       return bfd_reloc_ok;
 599     }
 600
 601   /* If we are not producing relocateable output, return an error if
 602      the symbol is not defined.  An undefined weak symbol is
 603      considered to have a value of zero (SVR4 ABI, p. 4-27).  */
 604   if (bfd_is_und_section (symbol->section)
 605       && (symbol->flags & BSF_WEAK) == 0
 606       && output_bfd == (bfd *) NULL)
 607     flag = bfd_reloc_undefined;
 608
 609   /* If there is a function supplied to handle this relocation type,
 610      call it.  It'll return `bfd_reloc_continue' if further processing
 611      can be done.  */
 612   if (howto->special_function)
 613     {
 614       bfd_reloc_status_type cont;
 615       cont = howto->special_function (abfd, reloc_entry, symbol, data,
 616                                       input_section, output_bfd,
 617                                       error_message);
 618       if (cont != bfd_reloc_continue)
 619         return cont;
 620     }
 621
 622   /* Is the address of the relocation really within the section?  */
 623   if (reloc_entry->address > input_section->_cooked_size)
 624     return bfd_reloc_outofrange;
 625
 626   /* Work out which section the relocation is targetted at and the
 627      initial relocation command value.  */
 628
 629   /* Get symbol value.  (Common symbols are special.)  */
 630   if (bfd_is_com_section (symbol->section))
 631     relocation = 0;
 632   else
 633     relocation = symbol->value;
 634
 635
 636   reloc_target_output_section = symbol->section->output_section;
 637
 638   /* Convert input-section-relative symbol value to absolute.  */
 639   if (output_bfd && howto->partial_inplace == false)
 640     output_base = 0;
 641   else
 642     output_base = reloc_target_output_section->vma;
 643
 644   relocation += output_base + symbol->section->output_offset;
 645
 646   /* Add in supplied addend.  */
 647   relocation += reloc_entry->addend;
 648
 649   /* Here the variable relocation holds the final address of the
 650      symbol we are relocating against, plus any addend.  */
 651
 652   if (howto->pc_relative == true)
 653     {
 654       /* This is a PC relative relocation.  We want to set RELOCATION
 655          to the distance between the address of the symbol and the
 656          location.  RELOCATION is already the address of the symbol.
 657
 658          We start by subtracting the address of the section containing
 659          the location.
 660
 661          If pcrel_offset is set, we must further subtract the position
 662          of the location within the section.  Some targets arrange for
 663          the addend to be the negative of the position of the location
 664          within the section; for example, i386-aout does this.  For
 665          i386-aout, pcrel_offset is false.  Some other targets do not
 666          include the position of the location; for example, m88kbcs,
 667          or ELF.  For those targets, pcrel_offset is true.
 668
 669          If we are producing relocateable output, then we must ensure
 670          that this reloc will be correctly computed when the final
 671          relocation is done.  If pcrel_offset is false we want to wind
 672          up with the negative of the location within the section,
 673          which means we must adjust the existing addend by the change
 674          in the location within the section.  If pcrel_offset is true
 675          we do not want to adjust the existing addend at all.
 676
 677          FIXME: This seems logical to me, but for the case of
 678          producing relocateable output it is not what the code
 679          actually does.  I don't want to change it, because it seems
 680          far too likely that something will break.  */
 681
 682       relocation -=
 683         input_section->output_section->vma + input_section->output_offset;
 684
 685       if (howto->pcrel_offset == true)
 686         relocation -= reloc_entry->address;
 687     }
 688
 689   if (output_bfd != (bfd *) NULL)
 690     {
 691       if (howto->partial_inplace == false)
 692         {
 693           /* This is a partial relocation, and we want to apply the relocation
 694              to the reloc entry rather than the raw data. Modify the reloc
 695              inplace to reflect what we now know.  */
 696           reloc_entry->addend = relocation;
 697           reloc_entry->address += input_section->output_offset;
 698           return flag;
 699         }
 700       else
 701         {
 702           /* This is a partial relocation, but inplace, so modify the
 703              reloc record a bit.
 704
 705              If we've relocated with a symbol with a section, change
 706              into a ref to the section belonging to the symbol.  */
 707
 708           reloc_entry->address += input_section->output_offset;
 709
 710           /* WTF?? */
 711           if (abfd->xvec->flavour == bfd_target_coff_flavour
 712               && strcmp (abfd->xvec->name, "aixcoff-rs6000") != 0
 713               && strcmp (abfd->xvec->name, "xcoff-powermac") != 0
 714               && strcmp (abfd->xvec->name, "coff-Intel-little") != 0
 715               && strcmp (abfd->xvec->name, "coff-Intel-big") != 0)
 716             {
 717 #if 1
 718               /* For m68k-coff, the addend was being subtracted twice during
 719                  relocation with -r.  Removing the line below this comment
 720                  fixes that problem; see PR 2953.
 721
 722 However, Ian wrote the following, regarding removing the line below,
 723 which explains why it is still enabled:  --djm
 724
 725 If you put a patch like that into BFD you need to check all the COFF
 726 linkers.  I am fairly certain that patch will break coff-i386 (e.g.,
 727 SCO); see coff_i386_reloc in coff-i386.c where I worked around the
 728 problem in a different way.  There may very well be a reason that the
 729 code works as it does.
 730
 731 Hmmm.  The first obvious point is that bfd_perform_relocation should
 732 not have any tests that depend upon the flavour.  It's seem like
 733 entirely the wrong place for such a thing.  The second obvious point
 734 is that the current code ignores the reloc addend when producing
 735 relocateable output for COFF.  That's peculiar.  In fact, I really
 736 have no idea what the point of the line you want to remove is.
 737
 738 A typical COFF reloc subtracts the old value of the symbol and adds in
 739 the new value to the location in the object file (if it's a pc
 740 relative reloc it adds the difference between the symbol value and the
 741 location).  When relocating we need to preserve that property.
 742
 743 BFD handles this by setting the addend to the negative of the old
 744 value of the symbol.  Unfortunately it handles common symbols in a
 745 non-standard way (it doesn't subtract the old value) but that's a
 746 different story (we can't change it without losing backward
 747 compatibility with old object files) (coff-i386 does subtract the old
 748 value, to be compatible with existing coff-i386 targets, like SCO).
 749
 750 So everything works fine when not producing relocateable output.  When
 751 we are producing relocateable output, logically we should do exactly
 752 what we do when not producing relocateable output.  Therefore, your
 753 patch is correct.  In fact, it should probably always just set
 754 reloc_entry->addend to 0 for all cases, since it is, in fact, going to
 755 add the value into the object file.  This won't hurt the COFF code,
 756 which doesn't use the addend; I'm not sure what it will do to other
 757 formats (the thing to check for would be whether any formats both use
 758 the addend and set partial_inplace).
 759
 760 When I wanted to make coff-i386 produce relocateable output, I ran
 761 into the problem that you are running into: I wanted to remove that
 762 line.  Rather than risk it, I made the coff-i386 relocs use a special
 763 function; it's coff_i386_reloc in coff-i386.c.  The function
 764 specifically adds the addend field into the object file, knowing that
 765 bfd_perform_relocation is not going to.  If you remove that line, then
 766 coff-i386.c will wind up adding the addend field in twice.  It's
 767 trivial to fix; it just needs to be done.
 768
 769 The problem with removing the line is just that it may break some
 770 working code.  With BFD it's hard to be sure of anything.  The right
 771 way to deal with this is simply to build and test at least all the
 772 supported COFF targets.  It should be straightforward if time and disk
 773 space consuming.  For each target:
 774     1) build the linker
 775     2) generate some executable, and link it using -r (I would
 776        probably use paranoia.o and link against newlib/libc.a, which
 777        for all the supported targets would be available in
 778        /usr/cygnus/progressive/H-host/target/lib/libc.a).
 779     3) make the change to reloc.c
 780     4) rebuild the linker
 781     5) repeat step 2
 782     6) if the resulting object files are the same, you have at least
 783        made it no worse
 784     7) if they are different you have to figure out which version is
 785        right
 786 */
 787               relocation -= reloc_entry->addend;
 788 #endif
 789               reloc_entry->addend = 0;
 790             }
 791           else
 792             {
 793               reloc_entry->addend = relocation;
 794             }
 795         }
 796     }
 797   else
 798     {
 799       reloc_entry->addend = 0;
 800     }
 801
 802   /* FIXME: This overflow checking is incomplete, because the value
 803      might have overflowed before we get here.  For a correct check we
 804      need to compute the value in a size larger than bitsize, but we
 805      can't reasonably do that for a reloc the same size as a host
 806      machine word.
 807      FIXME: We should also do overflow checking on the result after
 808      adding in the value contained in the object file.  */
 809   if (howto->complain_on_overflow != complain_overflow_dont
 810       && flag == bfd_reloc_ok)
 811     flag = bfd_check_overflow (howto->complain_on_overflow,
 812                                howto->bitsize,
 813                                howto->rightshift,
 814                                bfd_arch_bits_per_address (abfd),
 815                                relocation);
 816
 817   /*
 818     Either we are relocating all the way, or we don't want to apply
 819     the relocation to the reloc entry (probably because there isn't
 820     any room in the output format to describe addends to relocs)
 821     */
 822
 823   /* The cast to bfd_vma avoids a bug in the Alpha OSF/1 C compiler
 824      (OSF version 1.3, compiler version 3.11).  It miscompiles the
 825      following program:
 826
 827      struct str
 828      {
 829        unsigned int i0;
 830      } s = { 0 };
 831
 832      int
 833      main ()
 834      {
 835        unsigned long x;
 836
 837        x = 0x100000000;
 838        x <<= (unsigned long) s.i0;
 839        if (x == 0)
 840          printf ("failed\n");
 841        else
 842          printf ("succeeded (%lx)\n", x);
 843      }
 844      */
 845
 846   relocation >>= (bfd_vma) howto->rightshift;
 847
 848   /* Shift everything up to where it's going to be used */
 849
 850   relocation <<= (bfd_vma) howto->bitpos;
 851
 852   /* Wait for the day when all have the mask in them */
 853
 854   /* What we do:
 855      i instruction to be left alone
 856      o offset within instruction
 857      r relocation offset to apply
 858      S src mask
 859      D dst mask
 860      N ~dst mask
 861      A part 1
 862      B part 2
 863      R result
 864
 865      Do this:
 866      i i i i i o o o o o        from bfd_get<size>
 867      and           S S S S S    to get the size offset we want
 868      +   r r r r r r r r r r  to get the final value to place
 869      and           D D D D D  to chop to right size
 870      -----------------------
 871      A A A A A
 872      And this:
 873      ...   i i i i i o o o o o  from bfd_get<size>
 874      and   N N N N N            get instruction
 875      -----------------------
 876      ...   B B B B B
 877
 878      And then:
 879      B B B B B
 880      or              A A A A A
 881      -----------------------
 882      R R R R R R R R R R        put into bfd_put<size>
 883      */
 884
 885 #define DOIT(x) \
 886   x = ( (x & ~howto->dst_mask) | (((x & howto->src_mask) +  relocation) & howto->dst_mask))
 887
 888   switch (howto->size)
 889     {
 890     case 0:
 891       {
 892         char x = bfd_get_8 (abfd, (char *) data + addr);
 893         DOIT (x);
 894         bfd_put_8 (abfd, x, (unsigned char *) data + addr);
 895       }
 896       break;
 897
 898     case 1:
 899       {
 900         short x = bfd_get_16 (abfd, (bfd_byte *) data + addr);
 901         DOIT (x);
 902         bfd_put_16 (abfd, x, (unsigned char *) data + addr);
 903       }
 904       break;
 905     case 2:
 906       {
 907         long x = bfd_get_32 (abfd, (bfd_byte *) data + addr);
 908         DOIT (x);
 909         bfd_put_32 (abfd, x, (bfd_byte *) data + addr);
 910       }
 911       break;
 912     case -2:
 913       {
 914         long x = bfd_get_32 (abfd, (bfd_byte *) data + addr);
 915         relocation = -relocation;
 916         DOIT (x);
 917         bfd_put_32 (abfd, x, (bfd_byte *) data + addr);
 918       }
 919       break;
 920
 921     case -1:
 922       {
 923         long x = bfd_get_16 (abfd, (bfd_byte *) data + addr);
 924         relocation = -relocation;
 925         DOIT (x);
 926         bfd_put_16 (abfd, x, (bfd_byte *) data + addr);
 927       }
 928       break;
 929
 930     case 3:
 931       /* Do nothing */
 932       break;
 933
 934     case 4:
 935 #ifdef BFD64
 936       {
 937         bfd_vma x = bfd_get_64 (abfd, (bfd_byte *) data + addr);
 938         DOIT (x);
 939         bfd_put_64 (abfd, x, (bfd_byte *) data + addr);
 940       }
 941 #else
 942       abort ();
 943 #endif
 944       break;
 945     default:
 946       return bfd_reloc_other;
 947     }
 948
 949   return flag;
 950 }
 951
 952 /*
 953 FUNCTION
 954         bfd_install_relocation
 955
 956 SYNOPSIS
 957         bfd_reloc_status_type
 958                 bfd_install_relocation
 959                         (bfd *abfd,
 960                          arelent *reloc_entry,
 961                          PTR data, bfd_vma data_start,
 962                          asection *input_section,
 963                          char **error_message);
 964
 965 DESCRIPTION
 966         This looks remarkably like <<bfd_perform_relocation>>, except it
 967         does not expect that the section contents have been filled in.
 968         I.e., it's suitable for use when creating, rather than applying
 969         a relocation.
 970
 971         For now, this function should be considered reserved for the
 972         assembler.
 973
 974 */
 975
 976
 977 bfd_reloc_status_type
 978 bfd_install_relocation (abfd, reloc_entry, data_start, data_start_offset,
 979                         input_section, error_message)
 980      bfd *abfd;
 981      arelent *reloc_entry;
 982      PTR data_start;
 983      bfd_vma data_start_offset;
 984      asection *input_section;
 985      char **error_message;
 986 {
 987   bfd_vma relocation;
 988   bfd_reloc_status_type flag = bfd_reloc_ok;
 989   bfd_size_type addr = reloc_entry->address;
 990   bfd_vma output_base = 0;
 991   reloc_howto_type *howto = reloc_entry->howto;
 992   asection *reloc_target_output_section;
 993   asymbol *symbol;
 994   bfd_byte *data;
 995
 996   symbol = *(reloc_entry->sym_ptr_ptr);
 997   if (bfd_is_abs_section (symbol->section))
 998     {
 999       reloc_entry->address += input_section->output_offset;
1000       return bfd_reloc_ok;
1001     }
1002
1003   /* If there is a function supplied to handle this relocation type,
1004      call it.  It'll return `bfd_reloc_continue' if further processing
1005      can be done.  */
1006   if (howto->special_function)
1007     {
1008       bfd_reloc_status_type cont;
1009
1010       /* XXX - The special_function calls haven't been fixed up to deal
1011          with creating new relocations and section contents.  */
1012       cont = howto->special_function (abfd, reloc_entry, symbol,
1013                                       /* XXX - Non-portable! */
1014                                       ((bfd_byte *) data_start
1015                                        - data_start_offset),
1016                                       input_section, abfd, error_message);
1017       if (cont != bfd_reloc_continue)
1018         return cont;
1019     }
1020
1021   /* Is the address of the relocation really within the section?  */
1022   if (reloc_entry->address > input_section->_cooked_size)
1023     return bfd_reloc_outofrange;
1024
1025   /* Work out which section the relocation is targetted at and the
1026      initial relocation command value.  */
1027
1028   /* Get symbol value.  (Common symbols are special.)  */
1029   if (bfd_is_com_section (symbol->section))
1030     relocation = 0;
1031   else
1032     relocation = symbol->value;
1033
1034   reloc_target_output_section = symbol->section->output_section;
1035
1036   /* Convert input-section-relative symbol value to absolute.  */
1037   if (howto->partial_inplace == false)
1038     output_base = 0;
1039   else
1040     output_base = reloc_target_output_section->vma;
1041
1042   relocation += output_base + symbol->section->output_offset;
1043
1044   /* Add in supplied addend.  */
1045   relocation += reloc_entry->addend;
1046
1047   /* Here the variable relocation holds the final address of the
1048      symbol we are relocating against, plus any addend.  */
1049
1050   if (howto->pc_relative == true)
1051     {
1052       /* This is a PC relative relocation.  We want to set RELOCATION
1053          to the distance between the address of the symbol and the
1054          location.  RELOCATION is already the address of the symbol.
1055
1056          We start by subtracting the address of the section containing
1057          the location.
1058
1059          If pcrel_offset is set, we must further subtract the position
1060          of the location within the section.  Some targets arrange for
1061          the addend to be the negative of the position of the location
1062          within the section; for example, i386-aout does this.  For
1063          i386-aout, pcrel_offset is false.  Some other targets do not
1064          include the position of the location; for example, m88kbcs,
1065          or ELF.  For those targets, pcrel_offset is true.
1066
1067          If we are producing relocateable output, then we must ensure
1068          that this reloc will be correctly computed when the final
1069          relocation is done.  If pcrel_offset is false we want to wind
1070          up with the negative of the location within the section,
1071          which means we must adjust the existing addend by the change
1072          in the location within the section.  If pcrel_offset is true
1073          we do not want to adjust the existing addend at all.
1074
1075          FIXME: This seems logical to me, but for the case of
1076          producing relocateable output it is not what the code
1077          actually does.  I don't want to change it, because it seems
1078          far too likely that something will break.  */
1079
1080       relocation -=
1081         input_section->output_section->vma + input_section->output_offset;
1082
1083       if (howto->pcrel_offset == true && howto->partial_inplace == true)
1084         relocation -= reloc_entry->address;
1085     }
1086
1087   if (howto->partial_inplace == false)
1088     {
1089       /* This is a partial relocation, and we want to apply the relocation
1090          to the reloc entry rather than the raw data. Modify the reloc
1091          inplace to reflect what we now know.  */
1092       reloc_entry->addend = relocation;
1093       reloc_entry->address += input_section->output_offset;
1094       return flag;
1095     }
1096   else
1097     {
1098       /* This is a partial relocation, but inplace, so modify the
1099          reloc record a bit.
1100
1101          If we've relocated with a symbol with a section, change
1102          into a ref to the section belonging to the symbol.  */
1103
1104       reloc_entry->address += input_section->output_offset;
1105
1106       /* WTF?? */
1107       if (abfd->xvec->flavour == bfd_target_coff_flavour
1108           && strcmp (abfd->xvec->name, "aixcoff-rs6000") != 0
1109           && strcmp (abfd->xvec->name, "xcoff-powermac") != 0
1110           && strcmp (abfd->xvec->name, "coff-Intel-little") != 0
1111           && strcmp (abfd->xvec->name, "coff-Intel-big") != 0)
1112         {
1113 #if 1
1114 /* For m68k-coff, the addend was being subtracted twice during
1115    relocation with -r.  Removing the line below this comment
1116    fixes that problem; see PR 2953.
1117
1118 However, Ian wrote the following, regarding removing the line below,
1119 which explains why it is still enabled:  --djm
1120
1121 If you put a patch like that into BFD you need to check all the COFF
1122 linkers.  I am fairly certain that patch will break coff-i386 (e.g.,
1123 SCO); see coff_i386_reloc in coff-i386.c where I worked around the
1124 problem in a different way.  There may very well be a reason that the
1125 code works as it does.
1126
1127 Hmmm.  The first obvious point is that bfd_install_relocation should
1128 not have any tests that depend upon the flavour.  It's seem like
1129 entirely the wrong place for such a thing.  The second obvious point
1130 is that the current code ignores the reloc addend when producing
1131 relocateable output for COFF.  That's peculiar.  In fact, I really
1132 have no idea what the point of the line you want to remove is.
1133
1134 A typical COFF reloc subtracts the old value of the symbol and adds in
1135 the new value to the location in the object file (if it's a pc
1136 relative reloc it adds the difference between the symbol value and the
1137 location).  When relocating we need to preserve that property.
1138
1139 BFD handles this by setting the addend to the negative of the old
1140 value of the symbol.  Unfortunately it handles common symbols in a
1141 non-standard way (it doesn't subtract the old value) but that's a
1142 different story (we can't change it without losing backward
1143 compatibility with old object files) (coff-i386 does subtract the old
1144 value, to be compatible with existing coff-i386 targets, like SCO).
1145
1146 So everything works fine when not producing relocateable output.  When
1147 we are producing relocateable output, logically we should do exactly
1148 what we do when not producing relocateable output.  Therefore, your
1149 patch is correct.  In fact, it should probably always just set
1150 reloc_entry->addend to 0 for all cases, since it is, in fact, going to
1151 add the value into the object file.  This won't hurt the COFF code,
1152 which doesn't use the addend; I'm not sure what it will do to other
1153 formats (the thing to check for would be whether any formats both use
1154 the addend and set partial_inplace).
1155
1156 When I wanted to make coff-i386 produce relocateable output, I ran
1157 into the problem that you are running into: I wanted to remove that
1158 line.  Rather than risk it, I made the coff-i386 relocs use a special
1159 function; it's coff_i386_reloc in coff-i386.c.  The function
1160 specifically adds the addend field into the object file, knowing that
1161 bfd_install_relocation is not going to.  If you remove that line, then
1162 coff-i386.c will wind up adding the addend field in twice.  It's
1163 trivial to fix; it just needs to be done.
1164
1165 The problem with removing the line is just that it may break some
1166 working code.  With BFD it's hard to be sure of anything.  The right
1167 way to deal with this is simply to build and test at least all the
1168 supported COFF targets.  It should be straightforward if time and disk
1169 space consuming.  For each target:
1170     1) build the linker
1171     2) generate some executable, and link it using -r (I would
1172        probably use paranoia.o and link against newlib/libc.a, which
1173        for all the supported targets would be available in
1174        /usr/cygnus/progressive/H-host/target/lib/libc.a).
1175     3) make the change to reloc.c
1176     4) rebuild the linker
1177     5) repeat step 2
1178     6) if the resulting object files are the same, you have at least
1179        made it no worse
1180     7) if they are different you have to figure out which version is
1181        right
1182 */
1183           relocation -= reloc_entry->addend;
1184 #endif
1185           reloc_entry->addend = 0;
1186         }
1187       else
1188         {
1189           reloc_entry->addend = relocation;
1190         }
1191     }
1192
1193   /* FIXME: This overflow checking is incomplete, because the value
1194      might have overflowed before we get here.  For a correct check we
1195      need to compute the value in a size larger than bitsize, but we
1196      can't reasonably do that for a reloc the same size as a host
1197      machine word.
1198      FIXME: We should also do overflow checking on the result after
1199      adding in the value contained in the object file.  */
1200   if (howto->complain_on_overflow != complain_overflow_dont)
1201     flag = bfd_check_overflow (howto->complain_on_overflow,
1202                                howto->bitsize,
1203                                howto->rightshift,
1204                                bfd_arch_bits_per_address (abfd),
1205                                relocation);
1206
1207   /*
1208     Either we are relocating all the way, or we don't want to apply
1209     the relocation to the reloc entry (probably because there isn't
1210     any room in the output format to describe addends to relocs)
1211     */
1212
1213   /* The cast to bfd_vma avoids a bug in the Alpha OSF/1 C compiler
1214      (OSF version 1.3, compiler version 3.11).  It miscompiles the
1215      following program:
1216
1217      struct str
1218      {
1219        unsigned int i0;
1220      } s = { 0 };
1221
1222      int
1223      main ()
1224      {
1225        unsigned long x;
1226
1227        x = 0x100000000;
1228        x <<= (unsigned long) s.i0;
1229        if (x == 0)
1230          printf ("failed\n");
1231        else
1232          printf ("succeeded (%lx)\n", x);
1233      }
1234      */
1235
1236   relocation >>= (bfd_vma) howto->rightshift;
1237
1238   /* Shift everything up to where it's going to be used */
1239
1240   relocation <<= (bfd_vma) howto->bitpos;
1241
1242   /* Wait for the day when all have the mask in them */
1243
1244   /* What we do:
1245      i instruction to be left alone
1246      o offset within instruction
1247      r relocation offset to apply
1248      S src mask
1249      D dst mask
1250      N ~dst mask
1251      A part 1
1252      B part 2
1253      R result
1254
1255      Do this:
1256      i i i i i o o o o o        from bfd_get<size>
1257      and           S S S S S    to get the size offset we want
1258      +   r r r r r r r r r r  to get the final value to place
1259      and           D D D D D  to chop to right size
1260      -----------------------
1261      A A A A A
1262      And this:
1263      ...   i i i i i o o o o o  from bfd_get<size>
1264      and   N N N N N            get instruction
1265      -----------------------
1266      ...   B B B B B
1267
1268      And then:
1269      B B B B B
1270      or              A A A A A
1271      -----------------------
1272      R R R R R R R R R R        put into bfd_put<size>
1273      */
1274
1275 #define DOIT(x) \
1276   x = ( (x & ~howto->dst_mask) | (((x & howto->src_mask) +  relocation) & howto->dst_mask))
1277
1278   data = (bfd_byte *) data_start + (addr - data_start_offset);
1279
1280   switch (howto->size)
1281     {
1282     case 0:
1283       {
1284         char x = bfd_get_8 (abfd, (char *) data);
1285         DOIT (x);
1286         bfd_put_8 (abfd, x, (unsigned char *) data);
1287       }
1288       break;
1289
1290     case 1:
1291       {
1292         short x = bfd_get_16 (abfd, (bfd_byte *) data);
1293         DOIT (x);
1294         bfd_put_16 (abfd, x, (unsigned char *) data);
1295       }
1296       break;
1297     case 2:
1298       {
1299         long x = bfd_get_32 (abfd, (bfd_byte *) data);
1300         DOIT (x);
1301         bfd_put_32 (abfd, x, (bfd_byte *) data);
1302       }
1303       break;
1304     case -2:
1305       {
1306         long x = bfd_get_32 (abfd, (bfd_byte *) data);
1307         relocation = -relocation;
1308         DOIT (x);
1309         bfd_put_32 (abfd, x, (bfd_byte *) data);
1310       }
1311       break;
1312
1313     case 3:
1314       /* Do nothing */
1315       break;
1316
1317     case 4:
1318       {
1319         bfd_vma x = bfd_get_64 (abfd, (bfd_byte *) data);
1320         DOIT (x);
1321         bfd_put_64 (abfd, x, (bfd_byte *) data);
1322       }
1323       break;
1324     default:
1325       return bfd_reloc_other;
1326     }
1327
1328   return flag;
1329 }
1330
1331 /* This relocation routine is used by some of the backend linkers.
1332    They do not construct asymbol or arelent structures, so there is no
1333    reason for them to use bfd_perform_relocation.  Also,
1334    bfd_perform_relocation is so hacked up it is easier to write a new
1335    function than to try to deal with it.
1336
1337    This routine does a final relocation.  Whether it is useful for a
1338    relocateable link depends upon how the object format defines
1339    relocations.
1340
1341    FIXME: This routine ignores any special_function in the HOWTO,
1342    since the existing special_function values have been written for
1343    bfd_perform_relocation.
1344
1345    HOWTO is the reloc howto information.
1346    INPUT_BFD is the BFD which the reloc applies to.
1347    INPUT_SECTION is the section which the reloc applies to.
1348    CONTENTS is the contents of the section.
1349    ADDRESS is the address of the reloc within INPUT_SECTION.
1350    VALUE is the value of the symbol the reloc refers to.
1351    ADDEND is the addend of the reloc.  */
1352
1353 bfd_reloc_status_type
1354 _bfd_final_link_relocate (howto, input_bfd, input_section, contents, address,
1355                           value, addend)
1356      reloc_howto_type *howto;
1357      bfd *input_bfd;
1358      asection *input_section;
1359      bfd_byte *contents;
1360      bfd_vma address;
1361      bfd_vma value;
1362      bfd_vma addend;
1363 {
1364   bfd_vma relocation;
1365
1366   /* Sanity check the address.  */
1367   if (address > input_section->_raw_size)
1368     return bfd_reloc_outofrange;
1369
1370   /* This function assumes that we are dealing with a basic relocation
1371      against a symbol.  We want to compute the value of the symbol to
1372      relocate to.  This is just VALUE, the value of the symbol, plus
1373      ADDEND, any addend associated with the reloc.  */
1374   relocation = value + addend;
1375
1376   /* If the relocation is PC relative, we want to set RELOCATION to
1377      the distance between the symbol (currently in RELOCATION) and the
1378      location we are relocating.  Some targets (e.g., i386-aout)
1379      arrange for the contents of the section to be the negative of the
1380      offset of the location within the section; for such targets
1381      pcrel_offset is false.  Other targets (e.g., m88kbcs or ELF)
1382      simply leave the contents of the section as zero; for such
1383      targets pcrel_offset is true.  If pcrel_offset is false we do not
1384      need to subtract out the offset of the location within the
1385      section (which is just ADDRESS).  */
1386   if (howto->pc_relative)
1387     {
1388       relocation -= (input_section->output_section->vma
1389                      + input_section->output_offset);
1390       if (howto->pcrel_offset)
1391         relocation -= address;
1392     }
1393
1394   return _bfd_relocate_contents (howto, input_bfd, relocation,
1395                                  contents + address);
1396 }
1397
1398 /* Relocate a given location using a given value and howto.  */
1399
1400 bfd_reloc_status_type
1401 _bfd_relocate_contents (howto, input_bfd, relocation, location)
1402      reloc_howto_type *howto;
1403      bfd *input_bfd;
1404      bfd_vma relocation;
1405      bfd_byte *location;
1406 {
1407   int size;
1408   bfd_vma x;
1409   boolean overflow;
1410   unsigned int rightshift = howto->rightshift;
1411   unsigned int bitpos = howto->bitpos;
1412
1413   /* If the size is negative, negate RELOCATION.  This isn't very
1414      general.  */
1415   if (howto->size < 0)
1416     relocation = -relocation;
1417
1418   /* Get the value we are going to relocate.  */
1419   size = bfd_get_reloc_size (howto);
1420   switch (size)
1421     {
1422     default:
1423     case 0:
1424       abort ();
1425     case 1:
1426       x = bfd_get_8 (input_bfd, location);
1427       break;
1428     case 2:
1429       x = bfd_get_16 (input_bfd, location);
1430       break;
1431     case 4:
1432       x = bfd_get_32 (input_bfd, location);
1433       break;
1434     case 8:
1435 #ifdef BFD64
1436       x = bfd_get_64 (input_bfd, location);
1437 #else
1438       abort ();
1439 #endif
1440       break;
1441     }
1442
1443   /* Check for overflow.  FIXME: We may drop bits during the addition
1444      which we don't check for.  We must either check at every single
1445      operation, which would be tedious, or we must do the computations
1446      in a type larger than bfd_vma, which would be inefficient.  */
1447   overflow = false;
1448   if (howto->complain_on_overflow != complain_overflow_dont)
1449     {
1450       bfd_vma addrmask, fieldmask, signmask, ss;
1451       bfd_vma a, b, sum;
1452
1453       /* Get the values to be added together.  For signed and unsigned
1454          relocations, we assume that all values should be truncated to
1455          the size of an address.  For bitfields, all the bits matter.
1456          See also bfd_check_overflow.  */
1457       fieldmask = N_ONES (howto->bitsize);
1458       addrmask = N_ONES (bfd_arch_bits_per_address (input_bfd)) | fieldmask;
1459       a = relocation;
1460       b = x & howto->src_mask;
1461
1462       switch (howto->complain_on_overflow)
1463         {
1464         case complain_overflow_signed:
1465           a = (a & addrmask) >> rightshift;
1466
1467           /* If any sign bits are set, all sign bits must be set.
1468              That is, A must be a valid negative address after
1469              shifting.  */
1470           signmask = ~ (fieldmask >> 1);
1471           ss = a & signmask;
1472           if (ss != 0 && ss != ((addrmask >> rightshift) & signmask))
1473             overflow = true;
1474
1475           /* We only need this next bit of code if the sign bit of B
1476              is below the sign bit of A.  This would only happen if
1477              SRC_MASK had fewer bits than BITSIZE.  Note that if
1478              SRC_MASK has more bits than BITSIZE, we can get into
1479              trouble; we would need to verify that B is in range, as
1480              we do for A above.  */
1481           signmask = ((~ howto->src_mask) >> 1) & howto->src_mask;
1482           if ((b & signmask) != 0)
1483             {
1484               /* Set all the bits above the sign bit.  */
1485               b -= signmask <<= 1;
1486             }
1487
1488           b = (b & addrmask) >> bitpos;
1489
1490           /* Now we can do the addition.  */
1491           sum = a + b;
1492
1493           /* See if the result has the correct sign.  Bits above the
1494              sign bit are junk now; ignore them.  If the sum is
1495              positive, make sure we did not have all negative inputs;
1496              if the sum is negative, make sure we did not have all
1497              positive inputs.  The test below looks only at the sign
1498              bits, and it really just
1499                  SIGN (A) == SIGN (B) && SIGN (A) != SIGN (SUM)
1500              */
1501           signmask = (fieldmask >> 1) + 1;
1502           if (((~ (a ^ b)) & (a ^ sum)) & signmask)
1503             overflow = true;
1504
1505           break;
1506
1507         case complain_overflow_unsigned:
1508           /* Checking for an unsigned overflow is relatively easy:
1509              trim the addresses and add, and trim the result as well.
1510              Overflow is normally indicated when the result does not
1511              fit in the field.  However, we also need to consider the
1512              case when, e.g., fieldmask is 0x7fffffff or smaller, an
1513              input is 0x80000000, and bfd_vma is only 32 bits; then we
1514              will get sum == 0, but there is an overflow, since the
1515              inputs did not fit in the field.  Instead of doing a
1516              separate test, we can check for this by or-ing in the
1517              operands when testing for the sum overflowing its final
1518              field.  */
1519           a = (a & addrmask) >> rightshift;
1520           b = (b & addrmask) >> bitpos;
1521           sum = (a + b) & addrmask;
1522           if ((a | b | sum) & ~ fieldmask)
1523             overflow = true;
1524
1525           break;
1526
1527         case complain_overflow_bitfield:
1528           /* Much like unsigned, except no trimming with addrmask.  In
1529              addition, the sum overflows if there is a carry out of
1530              the bfd_vma, i.e., the sum is less than either input
1531              operand.  */
1532           a >>= rightshift;
1533           b >>= bitpos;
1534
1535           /* Bitfields are sometimes used for signed numbers; for
1536              example, a 13-bit field sometimes represents values in
1537              0..8191 and sometimes represents values in -4096..4095.
1538              If the field is signed and a is -4095 (0x1001) and b is
1539              -1 (0x1fff), the sum is -4096 (0x1000), but (0x1001 +
1540              0x1fff is 0x3000).  It's not clear how to handle this
1541              everywhere, since there is not way to know how many bits
1542              are significant in the relocation, but the original code
1543              assumed that it was fully sign extended, and we will keep
1544              that assumption.  */
1545           signmask = (fieldmask >> 1) + 1;
1546
1547           if ((a & ~ fieldmask) != 0)
1548             {
1549               /* Some bits out of the field are set.  This might not
1550                  be a problem: if this is a signed bitfield, it is OK
1551                  iff all the high bits are set, including the sign
1552                  bit.  We'll try setting all but the most significant
1553                  bit in the original relocation value: if this is all
1554                  ones, we are OK, assuming a signed bitfield.  */
1555               ss = (signmask << rightshift) - 1;
1556               if ((ss | relocation) != ~ (bfd_vma) 0)
1557                 overflow = true;
1558               a &= fieldmask;
1559             }
1560
1561           /* We just assume (b & ~ fieldmask) == 0.  */
1562
1563           sum = a + b;
1564           if (sum < a || (sum & ~ fieldmask) != 0)
1565             {
1566               /* There was a carry out, or the field overflow.  Test
1567                  for signed operands again.  Here is the overflow test
1568                  is as for complain_overflow_signed.  */
1569               if (((~ (a ^ b)) & (a ^ sum)) & signmask)
1570                 overflow = true;
1571             }
1572
1573           break;
1574
1575         default:
1576           abort ();
1577         }
1578     }
1579
1580   /* Put RELOCATION in the right bits.  */
1581   relocation >>= (bfd_vma) rightshift;
1582   relocation <<= (bfd_vma) bitpos;
1583
1584   /* Add RELOCATION to the right bits of X.  */
1585   x = ((x & ~howto->dst_mask)
1586        | (((x & howto->src_mask) + relocation) & howto->dst_mask));
1587
1588   /* Put the relocated value back in the object file.  */
1589   switch (size)
1590     {
1591     default:
1592     case 0:
1593       abort ();
1594     case 1:
1595       bfd_put_8 (input_bfd, x, location);
1596       break;
1597     case 2:
1598       bfd_put_16 (input_bfd, x, location);
1599       break;
1600     case 4:
1601       bfd_put_32 (input_bfd, x, location);
1602       break;
1603     case 8:
1604 #ifdef BFD64
1605       bfd_put_64 (input_bfd, x, location);
1606 #else
1607       abort ();
1608 #endif
1609       break;
1610     }
1611
1612   return overflow ? bfd_reloc_overflow : bfd_reloc_ok;
1613 }
1614
1615 /*
1616 DOCDD
1617 INODE
1618         howto manager,  , typedef arelent, Relocations
1619
1620 SECTION
1621         The howto manager
1622
1623         When an application wants to create a relocation, but doesn't
1624         know what the target machine might call it, it can find out by
1625         using this bit of code.
1626
1627 */
1628
1629 /*
1630 TYPEDEF
1631         bfd_reloc_code_type
1632
1633 DESCRIPTION
1634         The insides of a reloc code.  The idea is that, eventually, there
1635         will be one enumerator for every type of relocation we ever do.
1636         Pass one of these values to <<bfd_reloc_type_lookup>>, and it'll
1637         return a howto pointer.
1638
1639         This does mean that the application must determine the correct
1640         enumerator value; you can't get a howto pointer from a random set
1641         of attributes.
1642
1643 SENUM
1644    bfd_reloc_code_real
1645
1646 ENUM
1647   BFD_RELOC_64
1648 ENUMX
1649   BFD_RELOC_32
1650 ENUMX
1651   BFD_RELOC_26
1652 ENUMX
1653   BFD_RELOC_24
1654 ENUMX
1655   BFD_RELOC_16
1656 ENUMX
1657   BFD_RELOC_14
1658 ENUMX
1659   BFD_RELOC_8
1660 ENUMDOC
1661   Basic absolute relocations of N bits.
1662
1663 ENUM
1664   BFD_RELOC_64_PCREL
1665 ENUMX
1666   BFD_RELOC_32_PCREL
1667 ENUMX
1668   BFD_RELOC_24_PCREL
1669 ENUMX
1670   BFD_RELOC_16_PCREL
1671 ENUMX
1672   BFD_RELOC_12_PCREL
1673 ENUMX
1674   BFD_RELOC_8_PCREL
1675 ENUMDOC
1676   PC-relative relocations.  Sometimes these are relative to the address
1677 of the relocation itself; sometimes they are relative to the start of
1678 the section containing the relocation.  It depends on the specific target.
1679
1680 The 24-bit relocation is used in some Intel 960 configurations.
1681
1682 ENUM
1683   BFD_RELOC_32_GOT_PCREL
1684 ENUMX
1685   BFD_RELOC_16_GOT_PCREL
1686 ENUMX
1687   BFD_RELOC_8_GOT_PCREL
1688 ENUMX
1689   BFD_RELOC_32_GOTOFF
1690 ENUMX
1691   BFD_RELOC_16_GOTOFF
1692 ENUMX
1693   BFD_RELOC_LO16_GOTOFF
1694 ENUMX
1695   BFD_RELOC_HI16_GOTOFF
1696 ENUMX
1697   BFD_RELOC_HI16_S_GOTOFF
1698 ENUMX
1699   BFD_RELOC_8_GOTOFF
1700 ENUMX
1701   BFD_RELOC_32_PLT_PCREL
1702 ENUMX
1703   BFD_RELOC_24_PLT_PCREL
1704 ENUMX
1705   BFD_RELOC_16_PLT_PCREL
1706 ENUMX
1707   BFD_RELOC_8_PLT_PCREL
1708 ENUMX
1709   BFD_RELOC_32_PLTOFF
1710 ENUMX
1711   BFD_RELOC_16_PLTOFF
1712 ENUMX
1713   BFD_RELOC_LO16_PLTOFF
1714 ENUMX
1715   BFD_RELOC_HI16_PLTOFF
1716 ENUMX
1717   BFD_RELOC_HI16_S_PLTOFF
1718 ENUMX
1719   BFD_RELOC_8_PLTOFF
1720 ENUMDOC
1721   For ELF.
1722
1723 ENUM
1724   BFD_RELOC_68K_GLOB_DAT
1725 ENUMX
1726   BFD_RELOC_68K_JMP_SLOT
1727 ENUMX
1728   BFD_RELOC_68K_RELATIVE
1729 ENUMDOC
1730   Relocations used by 68K ELF.
1731
1732 ENUM
1733   BFD_RELOC_32_BASEREL
1734 ENUMX
1735   BFD_RELOC_16_BASEREL
1736 ENUMX
1737   BFD_RELOC_LO16_BASEREL
1738 ENUMX
1739   BFD_RELOC_HI16_BASEREL
1740 ENUMX
1741   BFD_RELOC_HI16_S_BASEREL
1742 ENUMX
1743   BFD_RELOC_8_BASEREL
1744 ENUMX
1745   BFD_RELOC_RVA
1746 ENUMDOC
1747   Linkage-table relative.
1748
1749 ENUM
1750   BFD_RELOC_8_FFnn
1751 ENUMDOC
1752   Absolute 8-bit relocation, but used to form an address like 0xFFnn.
1753
1754 ENUM
1755   BFD_RELOC_32_PCREL_S2
1756 ENUMX
1757   BFD_RELOC_16_PCREL_S2
1758 ENUMX
1759   BFD_RELOC_23_PCREL_S2
1760 ENUMDOC
1761   These PC-relative relocations are stored as word displacements --
1762 i.e., byte displacements shifted right two bits.  The 30-bit word
1763 displacement (<<32_PCREL_S2>> -- 32 bits, shifted 2) is used on the
1764 SPARC.  (SPARC tools generally refer to this as <<WDISP30>>.)  The
1765 signed 16-bit displacement is used on the MIPS, and the 23-bit
1766 displacement is used on the Alpha.
1767
1768 ENUM
1769   BFD_RELOC_HI22
1770 ENUMX
1771   BFD_RELOC_LO10
1772 ENUMDOC
1773   High 22 bits and low 10 bits of 32-bit value, placed into lower bits of
1774 the target word.  These are used on the SPARC.
1775
1776 ENUM
1777   BFD_RELOC_GPREL16
1778 ENUMX
1779   BFD_RELOC_GPREL32
1780 ENUMDOC
1781   For systems that allocate a Global Pointer register, these are
1782 displacements off that register.  These relocation types are
1783 handled specially, because the value the register will have is
1784 decided relatively late.
1785
1786
1787 ENUM
1788   BFD_RELOC_I960_CALLJ
1789 ENUMDOC
1790   Reloc types used for i960/b.out.
1791
1792 ENUM
1793   BFD_RELOC_NONE
1794 ENUMX
1795   BFD_RELOC_SPARC_WDISP22
1796 ENUMX
1797   BFD_RELOC_SPARC22
1798 ENUMX
1799   BFD_RELOC_SPARC13
1800 ENUMX
1801   BFD_RELOC_SPARC_GOT10
1802 ENUMX
1803   BFD_RELOC_SPARC_GOT13
1804 ENUMX
1805   BFD_RELOC_SPARC_GOT22
1806 ENUMX
1807   BFD_RELOC_SPARC_PC10
1808 ENUMX
1809   BFD_RELOC_SPARC_PC22
1810 ENUMX
1811   BFD_RELOC_SPARC_WPLT30
1812 ENUMX
1813   BFD_RELOC_SPARC_COPY
1814 ENUMX
1815   BFD_RELOC_SPARC_GLOB_DAT
1816 ENUMX
1817   BFD_RELOC_SPARC_JMP_SLOT
1818 ENUMX
1819   BFD_RELOC_SPARC_RELATIVE
1820 ENUMX
1821   BFD_RELOC_SPARC_UA32
1822 ENUMDOC
1823   SPARC ELF relocations.  There is probably some overlap with other
1824   relocation types already defined.
1825
1826 ENUM
1827   BFD_RELOC_SPARC_BASE13
1828 ENUMX
1829   BFD_RELOC_SPARC_BASE22
1830 ENUMDOC
1831   I think these are specific to SPARC a.out (e.g., Sun 4).
1832
1833 ENUMEQ
1834   BFD_RELOC_SPARC_64
1835   BFD_RELOC_64
1836 ENUMX
1837   BFD_RELOC_SPARC_10
1838 ENUMX
1839   BFD_RELOC_SPARC_11
1840 ENUMX
1841   BFD_RELOC_SPARC_OLO10
1842 ENUMX
1843   BFD_RELOC_SPARC_HH22
1844 ENUMX
1845   BFD_RELOC_SPARC_HM10
1846 ENUMX
1847   BFD_RELOC_SPARC_LM22
1848 ENUMX
1849   BFD_RELOC_SPARC_PC_HH22
1850 ENUMX
1851   BFD_RELOC_SPARC_PC_HM10
1852 ENUMX
1853   BFD_RELOC_SPARC_PC_LM22
1854 ENUMX
1855   BFD_RELOC_SPARC_WDISP16
1856 ENUMX
1857   BFD_RELOC_SPARC_WDISP19
1858 ENUMX
1859   BFD_RELOC_SPARC_7
1860 ENUMX
1861   BFD_RELOC_SPARC_6
1862 ENUMX
1863   BFD_RELOC_SPARC_5
1864 ENUMEQX
1865   BFD_RELOC_SPARC_DISP64
1866   BFD_RELOC_64_PCREL
1867 ENUMX
1868   BFD_RELOC_SPARC_PLT64
1869 ENUMX
1870   BFD_RELOC_SPARC_HIX22
1871 ENUMX
1872   BFD_RELOC_SPARC_LOX10
1873 ENUMX
1874   BFD_RELOC_SPARC_H44
1875 ENUMX
1876   BFD_RELOC_SPARC_M44
1877 ENUMX
1878   BFD_RELOC_SPARC_L44
1879 ENUMX
1880   BFD_RELOC_SPARC_REGISTER
1881 ENUMDOC
1882   SPARC64 relocations
1883
1884 ENUM
1885   BFD_RELOC_SPARC_REV32
1886 ENUMDOC
1887   SPARC little endian relocation
1888
1889 ENUM
1890   BFD_RELOC_ALPHA_GPDISP_HI16
1891 ENUMDOC
1892   Alpha ECOFF and ELF relocations.  Some of these treat the symbol or
1893      "addend" in some special way.
1894   For GPDISP_HI16 ("gpdisp") relocations, the symbol is ignored when
1895      writing; when reading, it will be the absolute section symbol.  The
1896      addend is the displacement in bytes of the "lda" instruction from
1897      the "ldah" instruction (which is at the address of this reloc).
1898 ENUM
1899   BFD_RELOC_ALPHA_GPDISP_LO16
1900 ENUMDOC
1901   For GPDISP_LO16 ("ignore") relocations, the symbol is handled as
1902      with GPDISP_HI16 relocs.  The addend is ignored when writing the
1903      relocations out, and is filled in with the file's GP value on
1904      reading, for convenience.
1905
1906 ENUM
1907   BFD_RELOC_ALPHA_GPDISP
1908 ENUMDOC
1909   The ELF GPDISP relocation is exactly the same as the GPDISP_HI16
1910      relocation except that there is no accompanying GPDISP_LO16
1911      relocation.
1912
1913 ENUM
1914   BFD_RELOC_ALPHA_LITERAL
1915 ENUMX
1916   BFD_RELOC_ALPHA_ELF_LITERAL
1917 ENUMX
1918   BFD_RELOC_ALPHA_LITUSE
1919 ENUMDOC
1920   The Alpha LITERAL/LITUSE relocs are produced by a symbol reference;
1921      the assembler turns it into a LDQ instruction to load the address of
1922      the symbol, and then fills in a register in the real instruction.
1923
1924      The LITERAL reloc, at the LDQ instruction, refers to the .lita
1925      section symbol.  The addend is ignored when writing, but is filled
1926      in with the file's GP value on reading, for convenience, as with the
1927      GPDISP_LO16 reloc.
1928
1929      The ELF_LITERAL reloc is somewhere between 16_GOTOFF and GPDISP_LO16.
1930      It should refer to the symbol to be referenced, as with 16_GOTOFF,
1931      but it generates output not based on the position within the .got
1932      section, but relative to the GP value chosen for the file during the
1933      final link stage.
1934
1935      The LITUSE reloc, on the instruction using the loaded address, gives
1936      information to the linker that it might be able to use to optimize
1937      away some literal section references.  The symbol is ignored (read
1938      as the absolute section symbol), and the "addend" indicates the type
1939      of instruction using the register:
1940               1 - "memory" fmt insn
1941               2 - byte-manipulation (byte offset reg)
1942               3 - jsr (target of branch)
1943
1944      The GNU linker currently doesn't do any of this optimizing.
1945
1946 ENUM
1947   BFD_RELOC_ALPHA_HINT
1948 ENUMDOC
1949   The HINT relocation indicates a value that should be filled into the
1950      "hint" field of a jmp/jsr/ret instruction, for possible branch-
1951      prediction logic which may be provided on some processors.
1952
1953 ENUM
1954   BFD_RELOC_ALPHA_LINKAGE
1955 ENUMDOC
1956   The LINKAGE relocation outputs a linkage pair in the object file,
1957      which is filled by the linker.
1958
1959 ENUM
1960   BFD_RELOC_ALPHA_CODEADDR
1961 ENUMDOC
1962   The CODEADDR relocation outputs a STO_CA in the object file,
1963      which is filled by the linker.
1964
1965 ENUM
1966   BFD_RELOC_MIPS_JMP
1967 ENUMDOC
1968   Bits 27..2 of the relocation address shifted right 2 bits;
1969      simple reloc otherwise.
1970
1971 ENUM
1972   BFD_RELOC_MIPS16_JMP
1973 ENUMDOC
1974   The MIPS16 jump instruction.
1975
1976 ENUM
1977   BFD_RELOC_MIPS16_GPREL
1978 ENUMDOC
1979   MIPS16 GP relative reloc.
1980
1981 ENUM
1982   BFD_RELOC_HI16
1983 ENUMDOC
1984   High 16 bits of 32-bit value; simple reloc.
1985 ENUM
1986   BFD_RELOC_HI16_S
1987 ENUMDOC
1988   High 16 bits of 32-bit value but the low 16 bits will be sign
1989      extended and added to form the final result.  If the low 16
1990      bits form a negative number, we need to add one to the high value
1991      to compensate for the borrow when the low bits are added.
1992 ENUM
1993   BFD_RELOC_LO16
1994 ENUMDOC
1995   Low 16 bits.
1996 ENUM
1997   BFD_RELOC_PCREL_HI16_S
1998 ENUMDOC
1999   Like BFD_RELOC_HI16_S, but PC relative.
2000 ENUM
2001   BFD_RELOC_PCREL_LO16
2002 ENUMDOC
2003   Like BFD_RELOC_LO16, but PC relative.
2004
2005 ENUMEQ
2006   BFD_RELOC_MIPS_GPREL
2007   BFD_RELOC_GPREL16
2008 ENUMDOC
2009   Relocation relative to the global pointer.
2010
2011 ENUM
2012   BFD_RELOC_MIPS_LITERAL
2013 ENUMDOC
2014   Relocation against a MIPS literal section.
2015
2016 ENUM
2017   BFD_RELOC_MIPS_GOT16
2018 ENUMX
2019   BFD_RELOC_MIPS_CALL16
2020 ENUMEQX
2021   BFD_RELOC_MIPS_GPREL32
2022   BFD_RELOC_GPREL32
2023 ENUMX
2024   BFD_RELOC_MIPS_GOT_HI16
2025 ENUMX
2026   BFD_RELOC_MIPS_GOT_LO16
2027 ENUMX
2028   BFD_RELOC_MIPS_CALL_HI16
2029 ENUMX
2030   BFD_RELOC_MIPS_CALL_LO16
2031 ENUMX
2032   BFD_RELOC_MIPS_SUB
2033 ENUMX
2034   BFD_RELOC_MIPS_GOT_PAGE
2035 ENUMX
2036   BFD_RELOC_MIPS_GOT_OFST
2037 ENUMX
2038   BFD_RELOC_MIPS_GOT_DISP
2039 COMMENT
2040 ENUMDOC
2041   MIPS ELF relocations.
2042
2043 COMMENT
2044
2045 ENUM
2046   BFD_RELOC_386_GOT32
2047 ENUMX
2048   BFD_RELOC_386_PLT32
2049 ENUMX
2050   BFD_RELOC_386_COPY
2051 ENUMX
2052   BFD_RELOC_386_GLOB_DAT
2053 ENUMX
2054   BFD_RELOC_386_JUMP_SLOT
2055 ENUMX
2056   BFD_RELOC_386_RELATIVE
2057 ENUMX
2058   BFD_RELOC_386_GOTOFF
2059 ENUMX
2060   BFD_RELOC_386_GOTPC
2061 ENUMDOC
2062   i386/elf relocations
2063
2064 ENUM
2065   BFD_RELOC_NS32K_IMM_8
2066 ENUMX
2067   BFD_RELOC_NS32K_IMM_16
2068 ENUMX
2069   BFD_RELOC_NS32K_IMM_32
2070 ENUMX
2071   BFD_RELOC_NS32K_IMM_8_PCREL
2072 ENUMX
2073   BFD_RELOC_NS32K_IMM_16_PCREL
2074 ENUMX
2075   BFD_RELOC_NS32K_IMM_32_PCREL
2076 ENUMX
2077   BFD_RELOC_NS32K_DISP_8
2078 ENUMX
2079   BFD_RELOC_NS32K_DISP_16
2080 ENUMX
2081   BFD_RELOC_NS32K_DISP_32
2082 ENUMX
2083   BFD_RELOC_NS32K_DISP_8_PCREL
2084 ENUMX
2085   BFD_RELOC_NS32K_DISP_16_PCREL
2086 ENUMX
2087   BFD_RELOC_NS32K_DISP_32_PCREL
2088 ENUMDOC
2089   ns32k relocations
2090
2091 ENUM
2092   BFD_RELOC_PPC_B26
2093 ENUMX
2094   BFD_RELOC_PPC_BA26
2095 ENUMX
2096   BFD_RELOC_PPC_TOC16
2097 ENUMX
2098   BFD_RELOC_PPC_B16
2099 ENUMX
2100   BFD_RELOC_PPC_B16_BRTAKEN
2101 ENUMX
2102   BFD_RELOC_PPC_B16_BRNTAKEN
2103 ENUMX
2104   BFD_RELOC_PPC_BA16
2105 ENUMX
2106   BFD_RELOC_PPC_BA16_BRTAKEN
2107 ENUMX
2108   BFD_RELOC_PPC_BA16_BRNTAKEN
2109 ENUMX
2110   BFD_RELOC_PPC_COPY
2111 ENUMX
2112   BFD_RELOC_PPC_GLOB_DAT
2113 ENUMX
2114   BFD_RELOC_PPC_JMP_SLOT
2115 ENUMX
2116   BFD_RELOC_PPC_RELATIVE
2117 ENUMX
2118   BFD_RELOC_PPC_LOCAL24PC
2119 ENUMX
2120   BFD_RELOC_PPC_EMB_NADDR32
2121 ENUMX
2122   BFD_RELOC_PPC_EMB_NADDR16
2123 ENUMX
2124   BFD_RELOC_PPC_EMB_NADDR16_LO
2125 ENUMX
2126   BFD_RELOC_PPC_EMB_NADDR16_HI
2127 ENUMX
2128   BFD_RELOC_PPC_EMB_NADDR16_HA
2129 ENUMX
2130   BFD_RELOC_PPC_EMB_SDAI16
2131 ENUMX
2132   BFD_RELOC_PPC_EMB_SDA2I16
2133 ENUMX
2134   BFD_RELOC_PPC_EMB_SDA2REL
2135 ENUMX
2136   BFD_RELOC_PPC_EMB_SDA21
2137 ENUMX
2138   BFD_RELOC_PPC_EMB_MRKREF
2139 ENUMX
2140   BFD_RELOC_PPC_EMB_RELSEC16
2141 ENUMX
2142   BFD_RELOC_PPC_EMB_RELST_LO
2143 ENUMX
2144   BFD_RELOC_PPC_EMB_RELST_HI
2145 ENUMX
2146   BFD_RELOC_PPC_EMB_RELST_HA
2147 ENUMX
2148   BFD_RELOC_PPC_EMB_BIT_FLD
2149 ENUMX
2150   BFD_RELOC_PPC_EMB_RELSDA
2151 ENUMDOC
2152   Power(rs6000) and PowerPC relocations.
2153
2154 ENUM
2155   BFD_RELOC_CTOR
2156 ENUMDOC
2157   The type of reloc used to build a contructor table - at the moment
2158   probably a 32 bit wide absolute relocation, but the target can choose.
2159   It generally does map to one of the other relocation types.
2160
2161 ENUM
2162   BFD_RELOC_ARM_PCREL_BRANCH
2163 ENUMDOC
2164   ARM 26 bit pc-relative branch.  The lowest two bits must be zero and are
2165   not stored in the instruction.
2166 ENUM
2167   BFD_RELOC_ARM_IMMEDIATE
2168 ENUMX
2169   BFD_RELOC_ARM_OFFSET_IMM
2170 ENUMX
2171   BFD_RELOC_ARM_SHIFT_IMM
2172 ENUMX
2173   BFD_RELOC_ARM_SWI
2174 ENUMX
2175   BFD_RELOC_ARM_MULTI
2176 ENUMX
2177   BFD_RELOC_ARM_CP_OFF_IMM
2178 ENUMX
2179   BFD_RELOC_ARM_ADR_IMM
2180 ENUMX
2181   BFD_RELOC_ARM_LDR_IMM
2182 ENUMX
2183   BFD_RELOC_ARM_LITERAL
2184 ENUMX
2185   BFD_RELOC_ARM_IN_POOL
2186 ENUMX
2187   BFD_RELOC_ARM_OFFSET_IMM8
2188 ENUMX
2189   BFD_RELOC_ARM_HWLITERAL
2190 ENUMX
2191   BFD_RELOC_ARM_THUMB_ADD
2192 ENUMX
2193   BFD_RELOC_ARM_THUMB_IMM
2194 ENUMX
2195   BFD_RELOC_ARM_THUMB_SHIFT
2196 ENUMX
2197   BFD_RELOC_ARM_THUMB_OFFSET
2198 ENUMX
2199   BFD_RELOC_ARM_GOT12
2200 ENUMX
2201   BFD_RELOC_ARM_GOT32
2202 ENUMX
2203   BFD_RELOC_ARM_JUMP_SLOT
2204 ENUMX
2205   BFD_RELOC_ARM_COPY
2206 ENUMX
2207   BFD_RELOC_ARM_GLOB_DAT
2208 ENUMX
2209   BFD_RELOC_ARM_PLT32
2210 ENUMX
2211   BFD_RELOC_ARM_RELATIVE
2212 ENUMX
2213   BFD_RELOC_ARM_GOTOFF
2214 ENUMX
2215   BFD_RELOC_ARM_GOTPC
2216 ENUMDOC
2217   These relocs are only used within the ARM assembler.  They are not
2218   (at present) written to any object files.
2219
2220 ENUM
2221   BFD_RELOC_SH_PCDISP8BY2
2222 ENUMX
2223   BFD_RELOC_SH_PCDISP12BY2
2224 ENUMX
2225   BFD_RELOC_SH_IMM4
2226 ENUMX
2227   BFD_RELOC_SH_IMM4BY2
2228 ENUMX
2229   BFD_RELOC_SH_IMM4BY4
2230 ENUMX
2231   BFD_RELOC_SH_IMM8
2232 ENUMX
2233   BFD_RELOC_SH_IMM8BY2
2234 ENUMX
2235   BFD_RELOC_SH_IMM8BY4
2236 ENUMX
2237   BFD_RELOC_SH_PCRELIMM8BY2
2238 ENUMX
2239   BFD_RELOC_SH_PCRELIMM8BY4
2240 ENUMX
2241   BFD_RELOC_SH_SWITCH16
2242 ENUMX
2243   BFD_RELOC_SH_SWITCH32
2244 ENUMX
2245   BFD_RELOC_SH_USES
2246 ENUMX
2247   BFD_RELOC_SH_COUNT
2248 ENUMX
2249   BFD_RELOC_SH_ALIGN
2250 ENUMX
2251   BFD_RELOC_SH_CODE
2252 ENUMX
2253   BFD_RELOC_SH_DATA
2254 ENUMX
2255   BFD_RELOC_SH_LABEL
2256 ENUMDOC
2257   Hitachi SH relocs.  Not all of these appear in object files.
2258
2259 ENUM
2260   BFD_RELOC_THUMB_PCREL_BRANCH9
2261 ENUMX
2262   BFD_RELOC_THUMB_PCREL_BRANCH12
2263 ENUMX
2264   BFD_RELOC_THUMB_PCREL_BRANCH23
2265 ENUMDOC
2266   Thumb 23-, 12- and 9-bit pc-relative branches.  The lowest bit must
2267   be zero and is not stored in the instruction.
2268
2269 ENUM
2270   BFD_RELOC_ARC_B22_PCREL
2271 ENUMDOC
2272   Argonaut RISC Core (ARC) relocs.
2273   ARC 22 bit pc-relative branch.  The lowest two bits must be zero and are
2274   not stored in the instruction.  The high 20 bits are installed in bits 26
2275   through 7 of the instruction.
2276 ENUM
2277   BFD_RELOC_ARC_B26
2278 ENUMDOC
2279   ARC 26 bit absolute branch.  The lowest two bits must be zero and are not
2280   stored in the instruction.  The high 24 bits are installed in bits 23
2281   through 0.
2282
2283 ENUM
2284   BFD_RELOC_D10V_10_PCREL_R
2285 ENUMDOC
2286   Mitsubishi D10V relocs.
2287   This is a 10-bit reloc with the right 2 bits
2288   assumed to be 0.
2289 ENUM
2290   BFD_RELOC_D10V_10_PCREL_L
2291 ENUMDOC
2292   Mitsubishi D10V relocs.
2293   This is a 10-bit reloc with the right 2 bits
2294   assumed to be 0.  This is the same as the previous reloc
2295   except it is in the left container, i.e.,
2296   shifted left 15 bits.
2297 ENUM
2298   BFD_RELOC_D10V_18
2299 ENUMDOC
2300   This is an 18-bit reloc with the right 2 bits
2301   assumed to be 0.
2302 ENUM
2303   BFD_RELOC_D10V_18_PCREL
2304 ENUMDOC
2305   This is an 18-bit reloc with the right 2 bits
2306   assumed to be 0.
2307
2308 ENUM
2309   BFD_RELOC_D30V_6
2310 ENUMDOC
2311   Mitsubishi D30V relocs.
2312   This is a 6-bit absolute reloc.
2313 ENUM
2314   BFD_RELOC_D30V_9_PCREL
2315 ENUMDOC
2316   This is a 6-bit pc-relative reloc with
2317   the right 3 bits assumed to be 0.
2318 ENUM
2319   BFD_RELOC_D30V_9_PCREL_R
2320 ENUMDOC
2321   This is a 6-bit pc-relative reloc with
2322   the right 3 bits assumed to be 0. Same
2323   as the previous reloc but on the right side
2324   of the container.
2325 ENUM
2326   BFD_RELOC_D30V_15
2327 ENUMDOC
2328   This is a 12-bit absolute reloc with the
2329   right 3 bitsassumed to be 0.
2330 ENUM
2331   BFD_RELOC_D30V_15_PCREL
2332 ENUMDOC
2333   This is a 12-bit pc-relative reloc with
2334   the right 3 bits assumed to be 0.
2335 ENUM
2336   BFD_RELOC_D30V_15_PCREL_R
2337 ENUMDOC
2338   This is a 12-bit pc-relative reloc with
2339   the right 3 bits assumed to be 0. Same
2340   as the previous reloc but on the right side
2341   of the container.
2342 ENUM
2343   BFD_RELOC_D30V_21
2344 ENUMDOC
2345   This is an 18-bit absolute reloc with
2346   the right 3 bits assumed to be 0.
2347 ENUM
2348   BFD_RELOC_D30V_21_PCREL
2349 ENUMDOC
2350   This is an 18-bit pc-relative reloc with
2351   the right 3 bits assumed to be 0.
2352 ENUM
2353   BFD_RELOC_D30V_21_PCREL_R
2354 ENUMDOC
2355   This is an 18-bit pc-relative reloc with
2356   the right 3 bits assumed to be 0. Same
2357   as the previous reloc but on the right side
2358   of the container.
2359 ENUM
2360   BFD_RELOC_D30V_32
2361 ENUMDOC
2362   This is a 32-bit absolute reloc.
2363 ENUM
2364   BFD_RELOC_D30V_32_PCREL
2365 ENUMDOC
2366   This is a 32-bit pc-relative reloc.
2367
2368 ENUM
2369   BFD_RELOC_M32R_24
2370 ENUMDOC
2371   Mitsubishi M32R relocs.
2372   This is a 24 bit absolute address.
2373 ENUM
2374   BFD_RELOC_M32R_10_PCREL
2375 ENUMDOC
2376   This is a 10-bit pc-relative reloc with the right 2 bits assumed to be 0.
2377 ENUM
2378   BFD_RELOC_M32R_18_PCREL
2379 ENUMDOC
2380   This is an 18-bit reloc with the right 2 bits assumed to be 0.
2381 ENUM
2382   BFD_RELOC_M32R_26_PCREL
2383 ENUMDOC
2384   This is a 26-bit reloc with the right 2 bits assumed to be 0.
2385 ENUM
2386   BFD_RELOC_M32R_HI16_ULO
2387 ENUMDOC
2388   This is a 16-bit reloc containing the high 16 bits of an address
2389   used when the lower 16 bits are treated as unsigned.
2390 ENUM
2391   BFD_RELOC_M32R_HI16_SLO
2392 ENUMDOC
2393   This is a 16-bit reloc containing the high 16 bits of an address
2394   used when the lower 16 bits are treated as signed.
2395 ENUM
2396   BFD_RELOC_M32R_LO16
2397 ENUMDOC
2398   This is a 16-bit reloc containing the lower 16 bits of an address.
2399 ENUM
2400   BFD_RELOC_M32R_SDA16
2401 ENUMDOC
2402   This is a 16-bit reloc containing the small data area offset for use in
2403   add3, load, and store instructions.
2404
2405 ENUM
2406   BFD_RELOC_V850_9_PCREL
2407 ENUMDOC
2408   This is a 9-bit reloc
2409 ENUM
2410   BFD_RELOC_V850_22_PCREL
2411 ENUMDOC
2412   This is a 22-bit reloc
2413
2414 ENUM
2415   BFD_RELOC_V850_SDA_16_16_OFFSET
2416 ENUMDOC
2417   This is a 16 bit offset from the short data area pointer.
2418 ENUM
2419   BFD_RELOC_V850_SDA_15_16_OFFSET
2420 ENUMDOC
2421   This is a 16 bit offset (of which only 15 bits are used) from the
2422   short data area pointer.
2423 ENUM
2424   BFD_RELOC_V850_ZDA_16_16_OFFSET
2425 ENUMDOC
2426   This is a 16 bit offset from the zero data area pointer.
2427 ENUM
2428   BFD_RELOC_V850_ZDA_15_16_OFFSET
2429 ENUMDOC
2430   This is a 16 bit offset (of which only 15 bits are used) from the
2431   zero data area pointer.
2432 ENUM
2433   BFD_RELOC_V850_TDA_6_8_OFFSET
2434 ENUMDOC
2435   This is an 8 bit offset (of which only 6 bits are used) from the
2436   tiny data area pointer.
2437 ENUM
2438   BFD_RELOC_V850_TDA_7_8_OFFSET
2439 ENUMDOC
2440   This is an 8bit offset (of which only 7 bits are used) from the tiny
2441   data area pointer.
2442 ENUM
2443   BFD_RELOC_V850_TDA_7_7_OFFSET
2444 ENUMDOC
2445   This is a 7 bit offset from the tiny data area pointer.
2446 ENUM
2447   BFD_RELOC_V850_TDA_16_16_OFFSET
2448 ENUMDOC
2449   This is a 16 bit offset from the tiny data area pointer.
2450 COMMENT
2451 ENUM
2452   BFD_RELOC_V850_TDA_4_5_OFFSET
2453 ENUMDOC
2454   This is a 5 bit offset (of which only 4 bits are used) from the tiny
2455   data area pointer.
2456 ENUM
2457   BFD_RELOC_V850_TDA_4_4_OFFSET
2458 ENUMDOC
2459   This is a 4 bit offset from the tiny data area pointer.
2460 ENUM
2461   BFD_RELOC_V850_SDA_16_16_SPLIT_OFFSET
2462 ENUMDOC
2463   This is a 16 bit offset from the short data area pointer, with the
2464   bits placed non-contigously in the instruction.
2465 ENUM
2466   BFD_RELOC_V850_ZDA_16_16_SPLIT_OFFSET
2467 ENUMDOC
2468   This is a 16 bit offset from the zero data area pointer, with the
2469   bits placed non-contigously in the instruction.
2470 ENUM
2471   BFD_RELOC_V850_CALLT_6_7_OFFSET
2472 ENUMDOC
2473   This is a 6 bit offset from the call table base pointer.
2474 ENUM
2475   BFD_RELOC_V850_CALLT_16_16_OFFSET
2476 ENUMDOC
2477   This is a 16 bit offset from the call table base pointer.
2478 COMMENT
2479
2480 ENUM
2481   BFD_RELOC_MN10300_32_PCREL
2482 ENUMDOC
2483   This is a 32bit pcrel reloc for the mn10300, offset by two bytes in the
2484   instruction.
2485 ENUM
2486   BFD_RELOC_MN10300_16_PCREL
2487 ENUMDOC
2488   This is a 16bit pcrel reloc for the mn10300, offset by two bytes in the
2489   instruction.
2490
2491 ENUM
2492   BFD_RELOC_TIC30_LDP
2493 ENUMDOC
2494   This is a 8bit DP reloc for the tms320c30, where the most
2495   significant 8 bits of a 24 bit word are placed into the least
2496   significant 8 bits of the opcode.
2497
2498 ENUM
2499   BFD_RELOC_FR30_48
2500 ENUMDOC
2501   This is a 48 bit reloc for the FR30 that stores 32 bits.
2502 ENUM
2503   BFD_RELOC_FR30_20
2504 ENUMDOC
2505   This is a 32 bit reloc for the FR30 that stores 20 bits split up into
2506   two sections.
2507 ENUM
2508   BFD_RELOC_FR30_6_IN_4
2509 ENUMDOC
2510   This is a 16 bit reloc for the FR30 that stores a 6 bit word offset in
2511   4 bits.
2512 ENUM
2513   BFD_RELOC_FR30_8_IN_8
2514 ENUMDOC
2515   This is a 16 bit reloc for the FR30 that stores an 8 bit byte offset
2516   into 8 bits.
2517 ENUM
2518   BFD_RELOC_FR30_9_IN_8
2519 ENUMDOC
2520   This is a 16 bit reloc for the FR30 that stores a 9 bit short offset
2521   into 8 bits.
2522 ENUM
2523   BFD_RELOC_FR30_10_IN_8
2524 ENUMDOC
2525   This is a 16 bit reloc for the FR30 that stores a 10 bit word offset
2526   into 8 bits.
2527 ENUM
2528   BFD_RELOC_FR30_9_PCREL
2529 ENUMDOC
2530   This is a 16 bit reloc for the FR30 that stores a 9 bit pc relative
2531   short offset into 8 bits.
2532 ENUM
2533   BFD_RELOC_FR30_12_PCREL
2534 ENUMDOC
2535   This is a 16 bit reloc for the FR30 that stores a 12 bit pc relative
2536   short offset into 11 bits.
2537
2538 ENUM
2539   BFD_RELOC_MCORE_PCREL_IMM8BY4
2540 ENUMX
2541   BFD_RELOC_MCORE_PCREL_IMM11BY2
2542 ENUMX
2543   BFD_RELOC_MCORE_PCREL_IMM4BY2
2544 ENUMX
2545   BFD_RELOC_MCORE_PCREL_32
2546 ENUMX
2547   BFD_RELOC_MCORE_PCREL_JSR_IMM11BY2
2548 ENUMX
2549   BFD_RELOC_MCORE_RVA
2550 ENUMDOC
2551   Motorola Mcore relocations.
2552
2553 ENUM
2554   BFD_RELOC_VTABLE_INHERIT
2555 ENUMX
2556   BFD_RELOC_VTABLE_ENTRY
2557 ENUMDOC
2558   These two relocations are used by the linker to determine which of
2559   the entries in a C++ virtual function table are actually used.  When
2560   the --gc-sections option is given, the linker will zero out the entries
2561   that are not used, so that the code for those functions need not be
2562   included in the output.
2563
2564   VTABLE_INHERIT is a zero-space relocation used to describe to the
2565   linker the inheritence tree of a C++ virtual function table.  The
2566   relocation's symbol should be the parent class' vtable, and the
2567   relocation should be located at the child vtable.
2568
2569   VTABLE_ENTRY is a zero-space relocation that describes the use of a
2570   virtual function table entry.  The reloc's symbol should refer to the
2571   table of the class mentioned in the code.  Off of that base, an offset
2572   describes the entry that is being used.  For Rela hosts, this offset
2573   is stored in the reloc's addend.  For Rel hosts, we are forced to put
2574   this offset in the reloc's section offset.
2575
2576 ENDSENUM
2577   BFD_RELOC_UNUSED
2578 CODE_FRAGMENT
2579 .
2580 .typedef enum bfd_reloc_code_real bfd_reloc_code_real_type;
2581 */
2582
2583
2584 /*
2585 FUNCTION
2586         bfd_reloc_type_lookup
2587
2588 SYNOPSIS
2589         reloc_howto_type *
2590         bfd_reloc_type_lookup (bfd *abfd, bfd_reloc_code_real_type code);
2591
2592 DESCRIPTION
2593         Return a pointer to a howto structure which, when
2594         invoked, will perform the relocation @var{code} on data from the
2595         architecture noted.
2596
2597 */
2598
2599
2600 reloc_howto_type *
2601 bfd_reloc_type_lookup (abfd, code)
2602      bfd *abfd;
2603      bfd_reloc_code_real_type code;
2604 {
2605   return BFD_SEND (abfd, reloc_type_lookup, (abfd, code));
2606 }
2607
2608 static reloc_howto_type bfd_howto_32 =
2609 HOWTO (0, 00, 2, 32, false, 0, complain_overflow_bitfield, 0, "VRT32", false, 0xffffffff, 0xffffffff, true);
2610
2611
2612 /*
2613 INTERNAL_FUNCTION
2614         bfd_default_reloc_type_lookup
2615
2616 SYNOPSIS
2617         reloc_howto_type *bfd_default_reloc_type_lookup
2618         (bfd *abfd, bfd_reloc_code_real_type  code);
2619
2620 DESCRIPTION
2621         Provides a default relocation lookup routine for any architecture.
2622
2623
2624 */
2625
2626 reloc_howto_type *
2627 bfd_default_reloc_type_lookup (abfd, code)
2628      bfd *abfd;
2629      bfd_reloc_code_real_type code;
2630 {
2631   switch (code)
2632     {
2633     case BFD_RELOC_CTOR:
2634       /* The type of reloc used in a ctor, which will be as wide as the
2635          address - so either a 64, 32, or 16 bitter.  */
2636       switch (bfd_get_arch_info (abfd)->bits_per_address)
2637         {
2638         case 64:
2639           BFD_FAIL ();
2640         case 32:
2641           return &bfd_howto_32;
2642         case 16:
2643           BFD_FAIL ();
2644         default:
2645           BFD_FAIL ();
2646         }
2647     default:
2648       BFD_FAIL ();
2649     }
2650   return (reloc_howto_type *) NULL;
2651 }
2652
2653 /*
2654 FUNCTION
2655         bfd_get_reloc_code_name
2656
2657 SYNOPSIS
2658         const char *bfd_get_reloc_code_name (bfd_reloc_code_real_type code);
2659
2660 DESCRIPTION
2661         Provides a printable name for the supplied relocation code.
2662         Useful mainly for printing error messages.
2663 */
2664
2665 const char *
2666 bfd_get_reloc_code_name (code)
2667      bfd_reloc_code_real_type code;
2668 {
2669   if (code > BFD_RELOC_UNUSED)
2670     return 0;
2671   return bfd_reloc_code_real_names[(int)code];
2672 }
2673
2674 /*
2675 INTERNAL_FUNCTION
2676         bfd_generic_relax_section
2677
2678 SYNOPSIS
2679         boolean bfd_generic_relax_section
2680          (bfd *abfd,
2681           asection *section,
2682           struct bfd_link_info *,
2683           boolean *);
2684
2685 DESCRIPTION
2686         Provides default handling for relaxing for back ends which
2687         don't do relaxing -- i.e., does nothing.
2688 */
2689
2690 /*ARGSUSED*/
2691 boolean
2692 bfd_generic_relax_section (abfd, section, link_info, again)
2693      bfd *abfd;
2694      asection *section;
2695      struct bfd_link_info *link_info;
2696      boolean *again;
2697 {
2698   *again = false;
2699   return true;
2700 }
2701
2702 /*
2703 INTERNAL_FUNCTION
2704         bfd_generic_gc_sections
2705
2706 SYNOPSIS
2707         boolean bfd_generic_gc_sections
2708          (bfd *, struct bfd_link_info *);
2709
2710 DESCRIPTION
2711         Provides default handling for relaxing for back ends which
2712         don't do section gc -- i.e., does nothing.
2713 */
2714
2715 /*ARGSUSED*/
2716 boolean
2717 bfd_generic_gc_sections (abfd, link_info)
2718      bfd *abfd;
2719      struct bfd_link_info *link_info;
2720 {
2721   return true;
2722 }
2723
2724 /*
2725 INTERNAL_FUNCTION
2726         bfd_generic_get_relocated_section_contents
2727
2728 SYNOPSIS
2729         bfd_byte *
2730            bfd_generic_get_relocated_section_contents (bfd *abfd,
2731              struct bfd_link_info *link_info,
2732              struct bfd_link_order *link_order,
2733              bfd_byte *data,
2734              boolean relocateable,
2735              asymbol **symbols);
2736
2737 DESCRIPTION
2738         Provides default handling of relocation effort for back ends
2739         which can't be bothered to do it efficiently.
2740
2741 */
2742
2743 bfd_byte *
2744 bfd_generic_get_relocated_section_contents (abfd, link_info, link_order, data,
2745                                             relocateable, symbols)
2746      bfd *abfd;
2747      struct bfd_link_info *link_info;
2748      struct bfd_link_order *link_order;
2749      bfd_byte *data;
2750      boolean relocateable;
2751      asymbol **symbols;
2752 {
2753   /* Get enough memory to hold the stuff */
2754   bfd *input_bfd = link_order->u.indirect.section->owner;
2755   asection *input_section = link_order->u.indirect.section;
2756
2757   long reloc_size = bfd_get_reloc_upper_bound (input_bfd, input_section);
2758   arelent **reloc_vector = NULL;
2759   long reloc_count;
2760
2761   if (reloc_size < 0)
2762     goto error_return;
2763
2764   reloc_vector = (arelent **) bfd_malloc ((size_t) reloc_size);
2765   if (reloc_vector == NULL && reloc_size != 0)
2766     goto error_return;
2767
2768   /* read in the section */
2769   if (!bfd_get_section_contents (input_bfd,
2770                                  input_section,
2771                                  (PTR) data,
2772                                  0,
2773                                  input_section->_raw_size))
2774     goto error_return;
2775
2776   /* We're not relaxing the section, so just copy the size info */
2777   input_section->_cooked_size = input_section->_raw_size;
2778   input_section->reloc_done = true;
2779
2780   reloc_count = bfd_canonicalize_reloc (input_bfd,
2781                                         input_section,
2782                                         reloc_vector,
2783                                         symbols);
2784   if (reloc_count < 0)
2785     goto error_return;
2786
2787   if (reloc_count > 0)
2788     {
2789       arelent **parent;
2790       for (parent = reloc_vector; *parent != (arelent *) NULL;
2791            parent++)
2792         {
2793           char *error_message = (char *) NULL;
2794           bfd_reloc_status_type r =
2795             bfd_perform_relocation (input_bfd,
2796                                     *parent,
2797                                     (PTR) data,
2798                                     input_section,
2799                                     relocateable ? abfd : (bfd *) NULL,
2800                                     &error_message);
2801
2802           if (relocateable)
2803             {
2804               asection *os = input_section->output_section;
2805
2806               /* A partial link, so keep the relocs */
2807               os->orelocation[os->reloc_count] = *parent;
2808               os->reloc_count++;
2809             }
2810
2811           if (r != bfd_reloc_ok)
2812             {
2813               switch (r)
2814                 {
2815                 case bfd_reloc_undefined:
2816                   if (!((*link_info->callbacks->undefined_symbol)
2817                         (link_info, bfd_asymbol_name (*(*parent)->sym_ptr_ptr),
2818                          input_bfd, input_section, (*parent)->address)))
2819                     goto error_return;
2820                   break;
2821                 case bfd_reloc_dangerous:
2822                   BFD_ASSERT (error_message != (char *) NULL);
2823                   if (!((*link_info->callbacks->reloc_dangerous)
2824                         (link_info, error_message, input_bfd, input_section,
2825                          (*parent)->address)))
2826                     goto error_return;
2827                   break;
2828                 case bfd_reloc_overflow:
2829                   if (!((*link_info->callbacks->reloc_overflow)
2830                         (link_info, bfd_asymbol_name (*(*parent)->sym_ptr_ptr),
2831                          (*parent)->howto->name, (*parent)->addend,
2832                          input_bfd, input_section, (*parent)->address)))
2833                     goto error_return;
2834                   break;
2835                 case bfd_reloc_outofrange:
2836                 default:
2837                   abort ();
2838                   break;
2839                 }
2840
2841             }
2842         }
2843     }
2844   if (reloc_vector != NULL)
2845     free (reloc_vector);
2846   return data;
2847
2848 error_return:
2849   if (reloc_vector != NULL)
2850     free (reloc_vector);
2851   return NULL;
2852 }