bfd/libaout.h

   1 /* BFD back-end data structures for a.out (and similar) files.
   2    Copyright 1990, 1991, 1992 Free Software Foundation, Inc.
   3    Written by Cygnus Support.
   4
   5 This file is part of BFD, the Binary File Descriptor library.
   6
   7 This program is free software; you can redistribute it and/or modify
   8 it under the terms of the GNU General Public License as published by
   9 the Free Software Foundation; either version 2 of the License, or
  10 (at your option) any later version.
  11
  12 This program is distributed in the hope that it will be useful,
  13 but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 GNU General Public License for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with this program; if not, write to the Free Software
  19 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */
  20
  21 #ifndef LIBAOUT_H
  22 #define LIBAOUT_H
  23
  24 /* We try to encapsulate the differences in the various a.out file
  25    variants in a few routines, and otherwise share large masses of code.
  26    This means we only have to fix bugs in one place, most of the time.  */
  27
  28 #include "bfdlink.h"
  29
  30 /* Parameterize the a.out code based on whether it is being built
  31    for a 32-bit architecture or a 64-bit architecture.  */
  32 #if ARCH_SIZE==64
  33 #define GET_WORD bfd_h_get_64
  34 #define GET_SWORD bfd_h_get_signed_64
  35 #define PUT_WORD bfd_h_put_64
  36 #ifndef NAME
  37 #define NAME(x,y) CAT3(x,_64_,y)
  38 #endif
  39 #define JNAME(x) CAT(x,_64)
  40 #define BYTES_IN_WORD 8
  41 #else /* ARCH_SIZE == 32 */
  42 #define GET_WORD bfd_h_get_32
  43 #define GET_SWORD bfd_h_get_signed_32
  44 #define PUT_WORD bfd_h_put_32
  45 #ifndef NAME
  46 #define NAME(x,y) CAT3(x,_32_,y)
  47 #endif
  48 #define JNAME(x) CAT(x,_32)
  49 #define BYTES_IN_WORD 4
  50 #endif /* ARCH_SIZE==32 */
  51
  52 /* Declare at file level, since used in parameter lists, which have
  53    weird scope.  */
  54 struct external_exec;
  55 struct external_nlist;
  56 struct reloc_ext_external;
  57 struct reloc_std_external;
  58 \f
  59 /* a.out backend linker hash table entries.  */
  60
  61 struct aout_link_hash_entry
  62 {
  63   struct bfd_link_hash_entry root;
  64   /* Symbol index in output file.  */
  65   int indx;
  66 };
  67
  68 /* a.out backend linker hash table.  */
  69
  70 struct aout_link_hash_table
  71 {
  72   struct bfd_link_hash_table root;
  73 };
  74
  75 /* Look up an entry in an a.out link hash table.  */
  76
  77 #define aout_link_hash_lookup(table, string, create, copy, follow) \
  78   ((struct aout_link_hash_entry *) \
  79    bfd_link_hash_lookup (&(table)->root, (string), (create), (copy), (follow)))
  80
  81 /* Traverse an a.out link hash table.  */
  82
  83 #define aout_link_hash_traverse(table, func, info)                      \
  84   (bfd_link_hash_traverse                                               \
  85    (&(table)->root,                                                     \
  86     (boolean (*) PARAMS ((struct bfd_link_hash_entry *, PTR))) (func),  \
  87     (info)))
  88
  89 /* Get the a.out link hash table from the info structure.  This is
  90    just a cast.  */
  91
  92 #define aout_hash_table(p) ((struct aout_link_hash_table *) ((p)->hash))
  93 \f
  94 /* Back-end information for various a.out targets.  */
  95 struct aout_backend_data
  96 {
  97   /* Are ZMAGIC files mapped contiguously?  If so, the text section may
  98      need more padding, if the segment size (granularity for memory access
  99      control) is larger than the page size.  */
 100   unsigned char zmagic_mapped_contiguous;
 101   /* If this flag is set, ZMAGIC/NMAGIC file headers get mapped in with the
 102      text section, which starts immediately after the file header.
 103      If not, the text section starts on the next page.  */
 104   unsigned char text_includes_header;
 105
 106   /* The value to pass to N_SET_FLAGS.  */
 107   unsigned char exec_hdr_flags;
 108
 109   /* If the text section VMA isn't specified, and we need an absolute
 110      address, use this as the default.  If we're producing a relocatable
 111      file, zero is always used.  */
 112   /* ?? Perhaps a callback would be a better choice?  Will this do anything
 113      reasonable for a format that handles multiple CPUs with different
 114      load addresses for each?  */
 115   bfd_vma default_text_vma;
 116
 117   /* Callback for setting the page and segment sizes, if they can't be
 118      trivially determined from the architecture.  */
 119   boolean (*set_sizes) PARAMS ((bfd *));
 120
 121   /* zmagic files only. For go32, the length of the exec header contributes
 122      to the size of the text section in the file for alignment purposes but
 123      does *not* get counted in the length of the text section. */
 124   unsigned char exec_header_not_counted;
 125
 126   /* Callback from the add symbols phase of the linker code to handle
 127      a dynamic object.  */
 128   boolean (*add_dynamic_symbols) PARAMS ((bfd *, struct bfd_link_info *));
 129
 130   /* Callback from the add symbols phase of the linker code to handle
 131      adding a single symbol to the global linker hash table.  */
 132   boolean (*add_one_symbol) PARAMS ((struct bfd_link_info *, bfd *,
 133                                      const char *, flagword, asection *,
 134                                      bfd_vma, const char *, boolean,
 135                                      boolean,
 136                                      struct bfd_link_hash_entry **));
 137
 138   /* Called to handle linking a dynamic object.  */
 139   boolean (*link_dynamic_object) PARAMS ((struct bfd_link_info *, bfd *));
 140
 141   /* Called for each global symbol being written out by the linker.
 142      This should write out the dynamic symbol information.  */
 143   boolean (*write_dynamic_symbol) PARAMS ((bfd *, struct bfd_link_info *,
 144                                            struct aout_link_hash_entry *));
 145
 146   /* This callback is called by the linker for each reloc against an
 147      external symbol.  RELOC is a pointer to the unswapped reloc.  If
 148      *SKIP is set to true, the reloc will be skipped.  */
 149   boolean (*check_dynamic_reloc) PARAMS ((struct bfd_link_info *info,
 150                                           bfd *input_bfd,
 151                                           asection *input_section,
 152                                           struct aout_link_hash_entry *h,
 153                                           PTR reloc, boolean *skip));
 154
 155   /* Called at the end of a link to finish up any dynamic linking
 156      information.  */
 157   boolean (*finish_dynamic_link) PARAMS ((bfd *, struct bfd_link_info *));
 158 };
 159 #define aout_backend_info(abfd) \
 160         ((CONST struct aout_backend_data *)((abfd)->xvec->backend_data))
 161
 162 /* This is the layout in memory of a "struct exec" while we process it.
 163    All 'lengths' are given as a number of bytes.
 164    All 'alignments' are for relinkable files only;  an alignment of
 165         'n' indicates the corresponding segment must begin at an
 166         address that is a multiple of (2**n).  */
 167
 168 struct internal_exec
 169 {
 170     long a_info;                /* Magic number and flags, packed */
 171     bfd_vma a_text;             /* length of text, in bytes  */
 172     bfd_vma a_data;             /* length of data, in bytes  */
 173     bfd_vma a_bss;              /* length of uninitialized data area in mem */
 174     bfd_vma a_syms;             /* length of symbol table data in file */
 175     bfd_vma a_entry;            /* start address */
 176     bfd_vma a_trsize;           /* length of text's relocation info, in bytes */
 177     bfd_vma a_drsize;           /* length of data's relocation info, in bytes */
 178     /* Added for i960 */
 179     bfd_vma a_tload;            /* Text runtime load address */
 180     bfd_vma a_dload;            /* Data runtime load address */
 181     unsigned char a_talign;     /* Alignment of text segment */
 182     unsigned char a_dalign;     /* Alignment of data segment */
 183     unsigned char a_balign;     /* Alignment of bss segment */
 184     char a_relaxable;           /* Enough info for linker relax */
 185 };
 186
 187 /* Magic number is written
 188 < MSB        >
 189 3130292827262524232221201918171615141312111009080706050403020100
 190 < FLAGS      >< MACHINE TYPE ><  MAGIC NUMBER                  >
 191 */
 192 /* Magic number for NetBSD is
 193 <MSB         >
 194 3130292827262524232221201918171615141312111009080706050403020100
 195 < FLAGS    ><                  ><  MAGIC NUMBER                >
 196 */
 197
 198 enum machine_type {
 199   M_UNKNOWN = 0,
 200   M_68010 = 1,
 201   M_68020 = 2,
 202   M_SPARC = 3,
 203   /* skip a bunch so we don't run into any of suns numbers */
 204   M_386 = 100,
 205   M_29K = 101,          /* AMD 29000 */
 206   M_386_DYNIX = 102,    /* Sequent running dynix */
 207   M_386_NETBSD = 134,           /* NetBSD/386 binary */
 208   M_MIPS1 = 151,        /* MIPS R2000/R3000 binary */
 209   M_MIPS2 = 152,        /* MIPS R4000/R6000 binary */
 210   M_HP200 = 200,        /* HP 200 (68010) BSD binary */
 211   M_HP300 = (300 % 256), /* HP 300 (68020+68881) BSD binary */
 212   M_HPUX = (0x20c % 256)/* HP 200/300 HPUX binary */
 213 };
 214
 215 #define N_DYNAMIC(exec) ((exec).a_info & 0x80000000)
 216
 217 #ifndef N_MAGIC
 218 # define N_MAGIC(exec) ((exec).a_info & 0xffff)
 219 #endif
 220
 221 #ifndef N_MACHTYPE
 222 # define N_MACHTYPE(exec) ((enum machine_type)(((exec).a_info >> 16) & 0xff))
 223 #endif
 224
 225 #ifndef N_FLAGS
 226 # define N_FLAGS(exec) (((exec).a_info >> 24) & 0xff)
 227 #endif
 228
 229 #ifndef N_SET_INFO
 230 # define N_SET_INFO(exec, magic, type, flags) \
 231 ((exec).a_info = ((magic) & 0xffff) \
 232  | (((int)(type) & 0xff) << 16) \
 233  | (((flags) & 0xff) << 24))
 234 #endif
 235
 236 #ifndef N_SET_DYNAMIC
 237 # define N_SET_DYNAMIC(exec, dynamic) \
 238 ((exec).a_info = (dynamic) ? ((exec).a_info | 0x80000000) : \
 239 ((exec).a_info & 0x7fffffff))
 240 #endif
 241
 242 #ifndef N_SET_MAGIC
 243 # define N_SET_MAGIC(exec, magic) \
 244 ((exec).a_info = (((exec).a_info & 0xffff0000) | ((magic) & 0xffff)))
 245 #endif
 246
 247 #ifndef N_SET_MACHTYPE
 248 # define N_SET_MACHTYPE(exec, machtype) \
 249 ((exec).a_info = \
 250  ((exec).a_info&0xff00ffff) | ((((int)(machtype))&0xff) << 16))
 251 #endif
 252
 253 #ifndef N_SET_FLAGS
 254 # define N_SET_FLAGS(exec, flags) \
 255 ((exec).a_info = \
 256  ((exec).a_info&0x00ffffff) | (((flags) & 0xff) << 24))
 257 #endif
 258
 259 typedef struct aout_symbol {
 260   asymbol symbol;
 261   short desc;
 262   char other;
 263   unsigned char type;
 264 } aout_symbol_type;
 265
 266 /* The `tdata' struct for all a.out-like object file formats.
 267    Various things depend on this struct being around any time an a.out
 268    file is being handled.  An example is dbxread.c in GDB.  */
 269
 270 struct aoutdata {
 271   struct internal_exec *hdr;            /* exec file header */
 272   aout_symbol_type *symbols;            /* symtab for input bfd */
 273
 274   /* For ease, we do this */
 275   asection *textsec;
 276   asection *datasec;
 277   asection *bsssec;
 278
 279   /* We remember these offsets so that after check_file_format, we have
 280      no dependencies on the particular format of the exec_hdr.  */
 281   file_ptr sym_filepos;
 282   file_ptr str_filepos;
 283
 284   /* Size of a relocation entry in external form */
 285   unsigned reloc_entry_size;
 286
 287   /* Size of a symbol table entry in external form */
 288   unsigned symbol_entry_size;
 289
 290   /* Page size - needed for alignment of demand paged files. */
 291   unsigned long page_size;
 292
 293   /* Segment size - needed for alignment of demand paged files. */
 294   unsigned long segment_size;
 295
 296   unsigned exec_bytes_size;
 297   unsigned vma_adjusted : 1;
 298
 299   /* used when a bfd supports several highly similar formats */
 300   enum {
 301     default_format = 0,
 302     gnu_encap_format } subformat;
 303
 304   enum {
 305     undecided_magic = 0,
 306     z_magic,
 307     o_magic,
 308     n_magic } magic;
 309
 310   /* The external symbol information.  */
 311   struct external_nlist *external_syms;
 312   bfd_size_type external_sym_count;
 313   char *external_strings;
 314   bfd_size_type external_string_size;
 315   struct aout_link_hash_entry **sym_hashes;
 316
 317   /* A pointer for shared library information.  */
 318   PTR dynamic_info;
 319 };
 320
 321 struct  aout_data_struct {
 322     struct aoutdata a;
 323     struct internal_exec e;
 324 };
 325
 326 #define adata(bfd)              ((bfd)->tdata.aout_data->a)
 327 #define exec_hdr(bfd)           (adata(bfd).hdr)
 328 #define obj_aout_symbols(bfd)   (adata(bfd).symbols)
 329 #define obj_textsec(bfd)        (adata(bfd).textsec)
 330 #define obj_datasec(bfd)        (adata(bfd).datasec)
 331 #define obj_bsssec(bfd)         (adata(bfd).bsssec)
 332 #define obj_sym_filepos(bfd)    (adata(bfd).sym_filepos)
 333 #define obj_str_filepos(bfd)    (adata(bfd).str_filepos)
 334 #define obj_reloc_entry_size(bfd) (adata(bfd).reloc_entry_size)
 335 #define obj_symbol_entry_size(bfd) (adata(bfd).symbol_entry_size)
 336 #define obj_aout_subformat(bfd) (adata(bfd).subformat)
 337 #define obj_aout_external_syms(bfd) (adata(bfd).external_syms)
 338 #define obj_aout_external_sym_count(bfd) (adata(bfd).external_sym_count)
 339 #define obj_aout_external_strings(bfd) (adata(bfd).external_strings)
 340 #define obj_aout_external_string_size(bfd) (adata(bfd).external_string_size)
 341 #define obj_aout_sym_hashes(bfd) (adata(bfd).sym_hashes)
 342 #define obj_aout_dynamic_info(bfd) (adata(bfd).dynamic_info)
 343
 344 /* We take the address of the first element of an asymbol to ensure that the
 345    macro is only ever applied to an asymbol */
 346 #define aout_symbol(asymbol) ((aout_symbol_type *)(&(asymbol)->the_bfd))
 347
 348 /* Information we keep for each a.out section.  This is currently only
 349    used by the a.out backend linker.  */
 350
 351 struct aout_section_data_struct
 352 {
 353   /* The unswapped relocation entries for this section.  */
 354   PTR relocs;
 355 };
 356
 357 #define aout_section_data(s) \
 358   ((struct aout_section_data_struct *) (s)->used_by_bfd)
 359
 360 /* Prototype declarations for functions defined in aoutx.h  */
 361
 362 boolean
 363 NAME(aout,squirt_out_relocs) PARAMS ((bfd *abfd, asection *section));
 364
 365 boolean
 366 NAME(aout,make_sections) PARAMS ((bfd *));
 367
 368 bfd_target *
 369 NAME(aout,some_aout_object_p) PARAMS ((bfd *abfd,
 370                         struct internal_exec *execp,
 371                         bfd_target * (*callback)(bfd *)));
 372
 373 boolean
 374 NAME(aout,mkobject) PARAMS ((bfd *abfd));
 375
 376 enum machine_type
 377 NAME(aout,machine_type) PARAMS ((enum bfd_architecture arch,
 378                                  unsigned long machine));
 379
 380 boolean
 381 NAME(aout,set_arch_mach) PARAMS ((bfd *abfd, enum bfd_architecture arch,
 382                                   unsigned long machine));
 383
 384 boolean
 385 NAME(aout,new_section_hook) PARAMS ((bfd *abfd, asection *newsect));
 386
 387 boolean
 388 NAME(aout,set_section_contents) PARAMS ((bfd *abfd, sec_ptr section,
 389                          PTR location, file_ptr offset, bfd_size_type count));
 390
 391 asymbol *
 392 NAME(aout,make_empty_symbol) PARAMS ((bfd *abfd));
 393
 394 boolean
 395 NAME(aout,translate_symbol_table) PARAMS ((bfd *, aout_symbol_type *,
 396                                            struct external_nlist *,
 397                                            bfd_size_type, char *,
 398                                            bfd_size_type,
 399                                            boolean dynamic));
 400
 401 boolean
 402 NAME(aout,slurp_symbol_table) PARAMS ((bfd *abfd));
 403
 404 boolean
 405 NAME(aout,write_syms) PARAMS ((bfd *abfd));
 406
 407 void
 408 NAME(aout,reclaim_symbol_table) PARAMS ((bfd *abfd));
 409
 410 long
 411 NAME(aout,get_symtab_upper_bound) PARAMS ((bfd *abfd));
 412
 413 long
 414 NAME(aout,get_symtab) PARAMS ((bfd *abfd, asymbol **location));
 415
 416 void
 417 NAME(aout,swap_ext_reloc_in) PARAMS ((bfd *, struct reloc_ext_external *,
 418                                       arelent *, asymbol **));
 419 void
 420 NAME(aout,swap_std_reloc_in) PARAMS ((bfd *, struct reloc_std_external *,
 421                                       arelent *, asymbol **));
 422
 423 boolean
 424 NAME(aout,slurp_reloc_table) PARAMS ((bfd *abfd, sec_ptr asect,
 425                                       asymbol **symbols));
 426
 427 long
 428 NAME(aout,canonicalize_reloc) PARAMS ((bfd *abfd, sec_ptr section,
 429                                        arelent **relptr, asymbol **symbols));
 430
 431 long
 432 NAME(aout,get_reloc_upper_bound) PARAMS ((bfd *abfd, sec_ptr asect));
 433
 434 void
 435 NAME(aout,reclaim_reloc) PARAMS ((bfd *ignore_abfd, sec_ptr ignore));
 436
 437 alent *
 438 NAME(aout,get_lineno) PARAMS ((bfd *ignore_abfd, asymbol *ignore_symbol));
 439
 440 void
 441 NAME(aout,print_symbol) PARAMS ((bfd *ignore_abfd, PTR file,
 442                             asymbol *symbol, bfd_print_symbol_type how));
 443
 444 void
 445 NAME(aout,get_symbol_info) PARAMS ((bfd *ignore_abfd,
 446                            asymbol *symbol, symbol_info *ret));
 447
 448 boolean
 449 NAME(aout,find_nearest_line) PARAMS ((bfd *abfd, asection *section,
 450       asymbol **symbols, bfd_vma offset, CONST char **filename_ptr,
 451       CONST char **functionname_ptr, unsigned int *line_ptr));
 452
 453 int
 454 NAME(aout,sizeof_headers) PARAMS ((bfd *abfd, boolean exec));
 455
 456 boolean
 457 NAME(aout,adjust_sizes_and_vmas) PARAMS ((bfd *abfd,
 458        bfd_size_type *text_size, file_ptr *text_end));
 459
 460 void
 461 NAME(aout,swap_exec_header_in) PARAMS ((bfd *abfd,
 462        struct external_exec *raw_bytes, struct internal_exec *execp));
 463
 464 void
 465 NAME(aout,swap_exec_header_out) PARAMS ((bfd *abfd,
 466        struct internal_exec *execp, struct external_exec *raw_bytes));
 467
 468 struct bfd_hash_entry *
 469 NAME(aout,link_hash_newfunc)
 470   PARAMS ((struct bfd_hash_entry *, struct bfd_hash_table *, const char *));
 471
 472 boolean
 473 NAME(aout,link_hash_table_init)
 474      PARAMS ((struct aout_link_hash_table *, bfd *,
 475               struct bfd_hash_entry *(*) (struct bfd_hash_entry *,
 476                                           struct bfd_hash_table *,
 477                                           const char *)));
 478
 479 struct bfd_link_hash_table *
 480 NAME(aout,link_hash_table_create) PARAMS ((bfd *));
 481
 482 boolean
 483 NAME(aout,link_add_symbols) PARAMS ((bfd *, struct bfd_link_info *));
 484
 485 boolean
 486 NAME(aout,final_link) PARAMS ((bfd *, struct bfd_link_info *,
 487                                void (*) (bfd *, file_ptr *, file_ptr *,
 488                                          file_ptr *)));
 489
 490 boolean
 491 NAME(aout,bfd_free_cached_info) PARAMS ((bfd *));
 492
 493 /* Prototypes for functions in stab-syms.c. */
 494
 495 CONST char *
 496 aout_stab_name PARAMS ((int code));
 497
 498 /* A.out uses the generic versions of these routines... */
 499
 500 #define aout_32_get_section_contents    _bfd_generic_get_section_contents
 501
 502 #define aout_64_get_section_contents    _bfd_generic_get_section_contents
 503 #ifndef NO_WRITE_HEADER_KLUDGE
 504 #define NO_WRITE_HEADER_KLUDGE 0
 505 #endif
 506
 507 #ifndef aout_32_bfd_is_local_label
 508 #define aout_32_bfd_is_local_label bfd_generic_is_local_label
 509 #endif
 510
 511 #ifndef WRITE_HEADERS
 512 #define WRITE_HEADERS(abfd, execp)                                            \
 513       {                                                                       \
 514         bfd_size_type text_size; /* dummy vars */                             \
 515         file_ptr text_end;                                                    \
 516         if (adata(abfd).magic == undecided_magic)                             \
 517           NAME(aout,adjust_sizes_and_vmas) (abfd, &text_size, &text_end);     \
 518                                                                               \
 519         execp->a_syms = bfd_get_symcount (abfd) * EXTERNAL_NLIST_SIZE;        \
 520         execp->a_entry = bfd_get_start_address (abfd);                        \
 521                                                                               \
 522         execp->a_trsize = ((obj_textsec (abfd)->reloc_count) *                \
 523                            obj_reloc_entry_size (abfd));                      \
 524         execp->a_drsize = ((obj_datasec (abfd)->reloc_count) *                \
 525                            obj_reloc_entry_size (abfd));                      \
 526         NAME(aout,swap_exec_header_out) (abfd, execp, &exec_bytes);           \
 527                                                                               \
 528         if (bfd_seek (abfd, (file_ptr) 0, SEEK_SET) != 0) return false;       \
 529         if (bfd_write ((PTR) &exec_bytes, 1, EXEC_BYTES_SIZE, abfd)           \
 530             != EXEC_BYTES_SIZE)                                               \
 531           return false;                                                       \
 532         /* Now write out reloc info, followed by syms and strings */          \
 533                                                                               \
 534         if (bfd_get_outsymbols (abfd) != (asymbol **) NULL                    \
 535             && bfd_get_symcount (abfd) != 0)                                  \
 536             {                                                                 \
 537               if (bfd_seek (abfd, (file_ptr)(N_SYMOFF(*execp)), SEEK_SET)     \
 538                   != 0)                                                       \
 539                 return false;                                                 \
 540                                                                               \
 541               if (! NAME(aout,write_syms)(abfd)) return false;                \
 542                                                                               \
 543               if (bfd_seek (abfd, (file_ptr)(N_TRELOFF(*execp)), SEEK_SET)    \
 544                   != 0)                                                       \
 545                 return false;                                                 \
 546                                                                               \
 547               if (!NAME(aout,squirt_out_relocs) (abfd, obj_textsec (abfd)))   \
 548                 return false;                                                 \
 549               if (bfd_seek (abfd, (file_ptr)(N_DRELOFF(*execp)), SEEK_SET)    \
 550                   != 0)                                                       \
 551                 return false;                                                 \
 552                                                                               \
 553               if (!NAME(aout,squirt_out_relocs)(abfd, obj_datasec (abfd)))    \
 554                 return false;                                                 \
 555             }                                                                 \
 556       }
 557 #endif
 558
 559 #endif /* ! defined (LIBAOUT_H) */