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   /* Whether this symbol has been written out.  */
  65   boolean written;
  66   /* Symbol index in output file.  */
  67   int indx;
  68 };
  69
  70 /* a.out backend linker hash table.  */
  71
  72 struct aout_link_hash_table
  73 {
  74   struct bfd_link_hash_table root;
  75 };
  76
  77 /* Look up an entry in an a.out link hash table.  */
  78
  79 #define aout_link_hash_lookup(table, string, create, copy, follow) \
  80   ((struct aout_link_hash_entry *) \
  81    bfd_link_hash_lookup (&(table)->root, (string), (create), (copy), (follow)))
  82
  83 /* Traverse an a.out link hash table.  */
  84
  85 #define aout_link_hash_traverse(table, func, info)                      \
  86   (bfd_link_hash_traverse                                               \
  87    (&(table)->root,                                                     \
  88     (boolean (*) PARAMS ((struct bfd_link_hash_entry *, PTR))) (func),  \
  89     (info)))
  90
  91 /* Get the a.out link hash table from the info structure.  This is
  92    just a cast.  */
  93
  94 #define aout_hash_table(p) ((struct aout_link_hash_table *) ((p)->hash))
  95 \f
  96 /* Back-end information for various a.out targets.  */
  97 struct aout_backend_data
  98 {
  99   /* Are ZMAGIC files mapped contiguously?  If so, the text section may
 100      need more padding, if the segment size (granularity for memory access
 101      control) is larger than the page size.  */
 102   unsigned char zmagic_mapped_contiguous;
 103   /* If this flag is set, ZMAGIC/NMAGIC file headers get mapped in with the
 104      text section, which starts immediately after the file header.
 105      If not, the text section starts on the next page.  */
 106   unsigned char text_includes_header;
 107
 108   /* The value to pass to N_SET_FLAGS.  */
 109   unsigned char exec_hdr_flags;
 110
 111   /* If the text section VMA isn't specified, and we need an absolute
 112      address, use this as the default.  If we're producing a relocatable
 113      file, zero is always used.  */
 114   /* ?? Perhaps a callback would be a better choice?  Will this do anything
 115      reasonable for a format that handles multiple CPUs with different
 116      load addresses for each?  */
 117   bfd_vma default_text_vma;
 118
 119   /* Callback for setting the page and segment sizes, if they can't be
 120      trivially determined from the architecture.  */
 121   boolean (*set_sizes) PARAMS ((bfd *));
 122
 123   /* zmagic files only. For go32, the length of the exec header contributes
 124      to the size of the text section in the file for alignment purposes but
 125      does *not* get counted in the length of the text section. */
 126   unsigned char exec_header_not_counted;
 127
 128   /* Callback from the add symbols phase of the linker code to handle
 129      a dynamic object.  */
 130   boolean (*add_dynamic_symbols) PARAMS ((bfd *, struct bfd_link_info *));
 131
 132   /* Callback from the add symbols phase of the linker code to handle
 133      adding a single symbol to the global linker hash table.  */
 134   boolean (*add_one_symbol) PARAMS ((struct bfd_link_info *, bfd *,
 135                                      const char *, flagword, asection *,
 136                                      bfd_vma, const char *, boolean,
 137                                      boolean,
 138                                      struct bfd_link_hash_entry **));
 139
 140   /* Called to handle linking a dynamic object.  */
 141   boolean (*link_dynamic_object) PARAMS ((struct bfd_link_info *, bfd *));
 142
 143   /* Called for each global symbol being written out by the linker.
 144      This should write out the dynamic symbol information.  */
 145   boolean (*write_dynamic_symbol) PARAMS ((bfd *, struct bfd_link_info *,
 146                                            struct aout_link_hash_entry *));
 147
 148   /* This callback is called by the linker for each reloc against an
 149      external symbol.  RELOC is a pointer to the unswapped reloc.  If
 150      *SKIP is set to true, the reloc will be skipped.  */
 151   boolean (*check_dynamic_reloc) PARAMS ((struct bfd_link_info *info,
 152                                           bfd *input_bfd,
 153                                           asection *input_section,
 154                                           struct aout_link_hash_entry *h,
 155                                           PTR reloc, boolean *skip));
 156
 157   /* Called at the end of a link to finish up any dynamic linking
 158      information.  */
 159   boolean (*finish_dynamic_link) PARAMS ((bfd *, struct bfd_link_info *));
 160 };
 161 #define aout_backend_info(abfd) \
 162         ((CONST struct aout_backend_data *)((abfd)->xvec->backend_data))
 163
 164 /* This is the layout in memory of a "struct exec" while we process it.
 165    All 'lengths' are given as a number of bytes.
 166    All 'alignments' are for relinkable files only;  an alignment of
 167         'n' indicates the corresponding segment must begin at an
 168         address that is a multiple of (2**n).  */
 169
 170 struct internal_exec
 171 {
 172     long a_info;                /* Magic number and flags, packed */
 173     bfd_vma a_text;             /* length of text, in bytes  */
 174     bfd_vma a_data;             /* length of data, in bytes  */
 175     bfd_vma a_bss;              /* length of uninitialized data area in mem */
 176     bfd_vma a_syms;             /* length of symbol table data in file */
 177     bfd_vma a_entry;            /* start address */
 178     bfd_vma a_trsize;           /* length of text's relocation info, in bytes */
 179     bfd_vma a_drsize;           /* length of data's relocation info, in bytes */
 180     /* Added for i960 */
 181     bfd_vma a_tload;            /* Text runtime load address */
 182     bfd_vma a_dload;            /* Data runtime load address */
 183     unsigned char a_talign;     /* Alignment of text segment */
 184     unsigned char a_dalign;     /* Alignment of data segment */
 185     unsigned char a_balign;     /* Alignment of bss segment */
 186     char a_relaxable;           /* Enough info for linker relax */
 187 };
 188
 189 /* Magic number is written
 190 < MSB        >
 191 3130292827262524232221201918171615141312111009080706050403020100
 192 < FLAGS      >< MACHINE TYPE ><  MAGIC NUMBER                  >
 193 */
 194 /* Magic number for NetBSD is
 195 <MSB         >
 196 3130292827262524232221201918171615141312111009080706050403020100
 197 < FLAGS    ><                  ><  MAGIC NUMBER                >
 198 */
 199
 200 enum machine_type {
 201   M_UNKNOWN = 0,
 202   M_68010 = 1,
 203   M_68020 = 2,
 204   M_SPARC = 3,
 205   /* skip a bunch so we don't run into any of suns numbers */
 206   M_386 = 100,
 207   M_29K = 101,          /* AMD 29000 */
 208   M_386_DYNIX = 102,    /* Sequent running dynix */
 209   M_386_NETBSD = 134,           /* NetBSD/386 binary */
 210   M_MIPS1 = 151,        /* MIPS R2000/R3000 binary */
 211   M_MIPS2 = 152,        /* MIPS R4000/R6000 binary */
 212   M_HP200 = 200,        /* HP 200 (68010) BSD binary */
 213   M_HP300 = (300 % 256), /* HP 300 (68020+68881) BSD binary */
 214   M_HPUX = (0x20c % 256)/* HP 200/300 HPUX binary */
 215 };
 216
 217 #define N_DYNAMIC(exec) ((exec).a_info & 0x80000000)
 218
 219 #ifndef N_MAGIC
 220 # define N_MAGIC(exec) ((exec).a_info & 0xffff)
 221 #endif
 222
 223 #ifndef N_MACHTYPE
 224 # define N_MACHTYPE(exec) ((enum machine_type)(((exec).a_info >> 16) & 0xff))
 225 #endif
 226
 227 #ifndef N_FLAGS
 228 # define N_FLAGS(exec) (((exec).a_info >> 24) & 0xff)
 229 #endif
 230
 231 #ifndef N_SET_INFO
 232 # define N_SET_INFO(exec, magic, type, flags) \
 233 ((exec).a_info = ((magic) & 0xffff) \
 234  | (((int)(type) & 0xff) << 16) \
 235  | (((flags) & 0xff) << 24))
 236 #endif
 237
 238 #ifndef N_SET_DYNAMIC
 239 # define N_SET_DYNAMIC(exec, dynamic) \
 240 ((exec).a_info = (dynamic) ? ((exec).a_info | 0x80000000) : \
 241 ((exec).a_info & 0x7fffffff))
 242 #endif
 243
 244 #ifndef N_SET_MAGIC
 245 # define N_SET_MAGIC(exec, magic) \
 246 ((exec).a_info = (((exec).a_info & 0xffff0000) | ((magic) & 0xffff)))
 247 #endif
 248
 249 #ifndef N_SET_MACHTYPE
 250 # define N_SET_MACHTYPE(exec, machtype) \
 251 ((exec).a_info = \
 252  ((exec).a_info&0xff00ffff) | ((((int)(machtype))&0xff) << 16))
 253 #endif
 254
 255 #ifndef N_SET_FLAGS
 256 # define N_SET_FLAGS(exec, flags) \
 257 ((exec).a_info = \
 258  ((exec).a_info&0x00ffffff) | (((flags) & 0xff) << 24))
 259 #endif
 260
 261 typedef struct aout_symbol {
 262   asymbol symbol;
 263   short desc;
 264   char other;
 265   unsigned char type;
 266 } aout_symbol_type;
 267
 268 /* The `tdata' struct for all a.out-like object file formats.
 269    Various things depend on this struct being around any time an a.out
 270    file is being handled.  An example is dbxread.c in GDB.  */
 271
 272 struct aoutdata {
 273   struct internal_exec *hdr;            /* exec file header */
 274   aout_symbol_type *symbols;            /* symtab for input bfd */
 275
 276   /* For ease, we do this */
 277   asection *textsec;
 278   asection *datasec;
 279   asection *bsssec;
 280
 281   /* We remember these offsets so that after check_file_format, we have
 282      no dependencies on the particular format of the exec_hdr.  */
 283   file_ptr sym_filepos;
 284   file_ptr str_filepos;
 285
 286   /* Size of a relocation entry in external form */
 287   unsigned reloc_entry_size;
 288
 289   /* Size of a symbol table entry in external form */
 290   unsigned symbol_entry_size;
 291
 292   /* Page size - needed for alignment of demand paged files. */
 293   unsigned long page_size;
 294
 295   /* Segment size - needed for alignment of demand paged files. */
 296   unsigned long segment_size;
 297
 298   unsigned exec_bytes_size;
 299   unsigned vma_adjusted : 1;
 300
 301   /* used when a bfd supports several highly similar formats */
 302   enum {
 303     default_format = 0,
 304     gnu_encap_format } subformat;
 305
 306   enum {
 307     undecided_magic = 0,
 308     z_magic,
 309     o_magic,
 310     n_magic } magic;
 311
 312   /* The external symbol information.  */
 313   struct external_nlist *external_syms;
 314   bfd_size_type external_sym_count;
 315   char *external_strings;
 316   bfd_size_type external_string_size;
 317   struct aout_link_hash_entry **sym_hashes;
 318
 319   /* A pointer for shared library information.  */
 320   PTR dynamic_info;
 321 };
 322
 323 struct  aout_data_struct {
 324     struct aoutdata a;
 325     struct internal_exec e;
 326 };
 327
 328 #define adata(bfd)              ((bfd)->tdata.aout_data->a)
 329 #define exec_hdr(bfd)           (adata(bfd).hdr)
 330 #define obj_aout_symbols(bfd)   (adata(bfd).symbols)
 331 #define obj_textsec(bfd)        (adata(bfd).textsec)
 332 #define obj_datasec(bfd)        (adata(bfd).datasec)
 333 #define obj_bsssec(bfd)         (adata(bfd).bsssec)
 334 #define obj_sym_filepos(bfd)    (adata(bfd).sym_filepos)
 335 #define obj_str_filepos(bfd)    (adata(bfd).str_filepos)
 336 #define obj_reloc_entry_size(bfd) (adata(bfd).reloc_entry_size)
 337 #define obj_symbol_entry_size(bfd) (adata(bfd).symbol_entry_size)
 338 #define obj_aout_subformat(bfd) (adata(bfd).subformat)
 339 #define obj_aout_external_syms(bfd) (adata(bfd).external_syms)
 340 #define obj_aout_external_sym_count(bfd) (adata(bfd).external_sym_count)
 341 #define obj_aout_external_strings(bfd) (adata(bfd).external_strings)
 342 #define obj_aout_external_string_size(bfd) (adata(bfd).external_string_size)
 343 #define obj_aout_sym_hashes(bfd) (adata(bfd).sym_hashes)
 344 #define obj_aout_dynamic_info(bfd) (adata(bfd).dynamic_info)
 345
 346 /* We take the address of the first element of an asymbol to ensure that the
 347    macro is only ever applied to an asymbol */
 348 #define aout_symbol(asymbol) ((aout_symbol_type *)(&(asymbol)->the_bfd))
 349
 350 /* Information we keep for each a.out section.  This is currently only
 351    used by the a.out backend linker.  */
 352
 353 struct aout_section_data_struct
 354 {
 355   /* The unswapped relocation entries for this section.  */
 356   PTR relocs;
 357 };
 358
 359 #define aout_section_data(s) \
 360   ((struct aout_section_data_struct *) (s)->used_by_bfd)
 361
 362 /* Prototype declarations for functions defined in aoutx.h  */
 363
 364 boolean
 365 NAME(aout,squirt_out_relocs) PARAMS ((bfd *abfd, asection *section));
 366
 367 boolean
 368 NAME(aout,make_sections) PARAMS ((bfd *));
 369
 370 bfd_target *
 371 NAME(aout,some_aout_object_p) PARAMS ((bfd *abfd,
 372                         struct internal_exec *execp,
 373                         bfd_target * (*callback)(bfd *)));
 374
 375 boolean
 376 NAME(aout,mkobject) PARAMS ((bfd *abfd));
 377
 378 enum machine_type
 379 NAME(aout,machine_type) PARAMS ((enum bfd_architecture arch,
 380                                  unsigned long machine,
 381                                  boolean *unknown));
 382
 383 boolean
 384 NAME(aout,set_arch_mach) PARAMS ((bfd *abfd, enum bfd_architecture arch,
 385                                   unsigned long machine));
 386
 387 boolean
 388 NAME(aout,new_section_hook) PARAMS ((bfd *abfd, asection *newsect));
 389
 390 boolean
 391 NAME(aout,set_section_contents) PARAMS ((bfd *abfd, sec_ptr section,
 392                          PTR location, file_ptr offset, bfd_size_type count));
 393
 394 asymbol *
 395 NAME(aout,make_empty_symbol) PARAMS ((bfd *abfd));
 396
 397 boolean
 398 NAME(aout,translate_symbol_table) PARAMS ((bfd *, aout_symbol_type *,
 399                                            struct external_nlist *,
 400                                            bfd_size_type, char *,
 401                                            bfd_size_type,
 402                                            boolean dynamic));
 403
 404 boolean
 405 NAME(aout,slurp_symbol_table) PARAMS ((bfd *abfd));
 406
 407 boolean
 408 NAME(aout,write_syms) PARAMS ((bfd *abfd));
 409
 410 void
 411 NAME(aout,reclaim_symbol_table) PARAMS ((bfd *abfd));
 412
 413 long
 414 NAME(aout,get_symtab_upper_bound) PARAMS ((bfd *abfd));
 415
 416 long
 417 NAME(aout,get_symtab) PARAMS ((bfd *abfd, asymbol **location));
 418
 419 void
 420 NAME(aout,swap_ext_reloc_in) PARAMS ((bfd *, struct reloc_ext_external *,
 421                                       arelent *, asymbol **));
 422 void
 423 NAME(aout,swap_std_reloc_in) PARAMS ((bfd *, struct reloc_std_external *,
 424                                       arelent *, asymbol **));
 425
 426 boolean
 427 NAME(aout,slurp_reloc_table) PARAMS ((bfd *abfd, sec_ptr asect,
 428                                       asymbol **symbols));
 429
 430 long
 431 NAME(aout,canonicalize_reloc) PARAMS ((bfd *abfd, sec_ptr section,
 432                                        arelent **relptr, asymbol **symbols));
 433
 434 long
 435 NAME(aout,get_reloc_upper_bound) PARAMS ((bfd *abfd, sec_ptr asect));
 436
 437 void
 438 NAME(aout,reclaim_reloc) PARAMS ((bfd *ignore_abfd, sec_ptr ignore));
 439
 440 alent *
 441 NAME(aout,get_lineno) PARAMS ((bfd *ignore_abfd, asymbol *ignore_symbol));
 442
 443 void
 444 NAME(aout,print_symbol) PARAMS ((bfd *ignore_abfd, PTR file,
 445                             asymbol *symbol, bfd_print_symbol_type how));
 446
 447 void
 448 NAME(aout,get_symbol_info) PARAMS ((bfd *ignore_abfd,
 449                            asymbol *symbol, symbol_info *ret));
 450
 451 boolean
 452 NAME(aout,find_nearest_line) PARAMS ((bfd *abfd, asection *section,
 453       asymbol **symbols, bfd_vma offset, CONST char **filename_ptr,
 454       CONST char **functionname_ptr, unsigned int *line_ptr));
 455
 456 int
 457 NAME(aout,sizeof_headers) PARAMS ((bfd *abfd, boolean exec));
 458
 459 boolean
 460 NAME(aout,adjust_sizes_and_vmas) PARAMS ((bfd *abfd,
 461        bfd_size_type *text_size, file_ptr *text_end));
 462
 463 void
 464 NAME(aout,swap_exec_header_in) PARAMS ((bfd *abfd,
 465        struct external_exec *raw_bytes, struct internal_exec *execp));
 466
 467 void
 468 NAME(aout,swap_exec_header_out) PARAMS ((bfd *abfd,
 469        struct internal_exec *execp, struct external_exec *raw_bytes));
 470
 471 struct bfd_hash_entry *
 472 NAME(aout,link_hash_newfunc)
 473   PARAMS ((struct bfd_hash_entry *, struct bfd_hash_table *, const char *));
 474
 475 boolean
 476 NAME(aout,link_hash_table_init)
 477      PARAMS ((struct aout_link_hash_table *, bfd *,
 478               struct bfd_hash_entry *(*) (struct bfd_hash_entry *,
 479                                           struct bfd_hash_table *,
 480                                           const char *)));
 481
 482 struct bfd_link_hash_table *
 483 NAME(aout,link_hash_table_create) PARAMS ((bfd *));
 484
 485 boolean
 486 NAME(aout,link_add_symbols) PARAMS ((bfd *, struct bfd_link_info *));
 487
 488 boolean
 489 NAME(aout,final_link) PARAMS ((bfd *, struct bfd_link_info *,
 490                                void (*) (bfd *, file_ptr *, file_ptr *,
 491                                          file_ptr *)));
 492
 493 boolean
 494 NAME(aout,bfd_free_cached_info) PARAMS ((bfd *));
 495
 496 /* Prototypes for functions in stab-syms.c. */
 497
 498 CONST char *
 499 aout_stab_name PARAMS ((int code));
 500
 501 /* A.out uses the generic versions of these routines... */
 502
 503 #define aout_32_get_section_contents    _bfd_generic_get_section_contents
 504
 505 #define aout_64_get_section_contents    _bfd_generic_get_section_contents
 506 #ifndef NO_WRITE_HEADER_KLUDGE
 507 #define NO_WRITE_HEADER_KLUDGE 0
 508 #endif
 509
 510 #ifndef aout_32_bfd_is_local_label
 511 #define aout_32_bfd_is_local_label bfd_generic_is_local_label
 512 #endif
 513
 514 #ifndef WRITE_HEADERS
 515 #define WRITE_HEADERS(abfd, execp)                                            \
 516       {                                                                       \
 517         bfd_size_type text_size; /* dummy vars */                             \
 518         file_ptr text_end;                                                    \
 519         if (adata(abfd).magic == undecided_magic)                             \
 520           NAME(aout,adjust_sizes_and_vmas) (abfd, &text_size, &text_end);     \
 521                                                                               \
 522         execp->a_syms = bfd_get_symcount (abfd) * EXTERNAL_NLIST_SIZE;        \
 523         execp->a_entry = bfd_get_start_address (abfd);                        \
 524                                                                               \
 525         execp->a_trsize = ((obj_textsec (abfd)->reloc_count) *                \
 526                            obj_reloc_entry_size (abfd));                      \
 527         execp->a_drsize = ((obj_datasec (abfd)->reloc_count) *                \
 528                            obj_reloc_entry_size (abfd));                      \
 529         NAME(aout,swap_exec_header_out) (abfd, execp, &exec_bytes);           \
 530                                                                               \
 531         if (bfd_seek (abfd, (file_ptr) 0, SEEK_SET) != 0) return false;       \
 532         if (bfd_write ((PTR) &exec_bytes, 1, EXEC_BYTES_SIZE, abfd)           \
 533             != EXEC_BYTES_SIZE)                                               \
 534           return false;                                                       \
 535         /* Now write out reloc info, followed by syms and strings */          \
 536                                                                               \
 537         if (bfd_get_outsymbols (abfd) != (asymbol **) NULL                    \
 538             && bfd_get_symcount (abfd) != 0)                                  \
 539             {                                                                 \
 540               if (bfd_seek (abfd, (file_ptr)(N_SYMOFF(*execp)), SEEK_SET)     \
 541                   != 0)                                                       \
 542                 return false;                                                 \
 543                                                                               \
 544               if (! NAME(aout,write_syms)(abfd)) return false;                \
 545                                                                               \
 546               if (bfd_seek (abfd, (file_ptr)(N_TRELOFF(*execp)), SEEK_SET)    \
 547                   != 0)                                                       \
 548                 return false;                                                 \
 549                                                                               \
 550               if (!NAME(aout,squirt_out_relocs) (abfd, obj_textsec (abfd)))   \
 551                 return false;                                                 \
 552               if (bfd_seek (abfd, (file_ptr)(N_DRELOFF(*execp)), SEEK_SET)    \
 553                   != 0)                                                       \
 554                 return false;                                                 \
 555                                                                               \
 556               if (!NAME(aout,squirt_out_relocs)(abfd, obj_datasec (abfd)))    \
 557                 return false;                                                 \
 558             }                                                                 \
 559       }
 560 #endif
 561
 562 #endif /* ! defined (LIBAOUT_H) */