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 /* We try to encapsulate the differences in the various a.out file
  22    variants in a few routines, and otherwise share large masses of code.
  23    This means we only have to fix bugs in one place, most of the time.  */
  24
  25 /* Parameterize the a.out code based on whether it is being built
  26    for a 32-bit architecture or a 64-bit architecture.  */
  27 #if ARCH_SIZE==64
  28 #define GET_WORD bfd_h_get_64
  29 #define GET_SWORD bfd_h_get_signed_64
  30 #define PUT_WORD bfd_h_put_64
  31 #ifndef NAME
  32 #define NAME(x,y) CAT3(x,_64_,y)
  33 #endif
  34 #define JNAME(x) CAT(x,_64)
  35 #define BYTES_IN_WORD 8
  36 #else /* ARCH_SIZE == 32 */
  37 #define GET_WORD bfd_h_get_32
  38 #define GET_SWORD bfd_h_get_signed_32
  39 #define PUT_WORD bfd_h_put_32
  40 #ifndef NAME
  41 #define NAME(x,y) CAT3(x,_32_,y)
  42 #endif
  43 #define JNAME(x) CAT(x,_32)
  44 #define BYTES_IN_WORD 4
  45 #endif /* ARCH_SIZE==32 */
  46
  47 /* Declare at file level, since used in parameter lists, which have
  48    weird scope.  */
  49 struct external_exec;
  50 struct external_nlist;
  51
  52 /* Back-end information for various a.out targets.  */
  53 struct aout_backend_data
  54 {
  55   /* Are ZMAGIC files mapped contiguously?  If so, the text section may
  56      need more padding, if the segment size (granularity for memory access
  57      control) is larger than the page size.  */
  58   unsigned char zmagic_mapped_contiguous;
  59   /* If this flag is set, ZMAGIC/NMAGIC file headers get mapped in with the
  60      text section, which starts immediately after the file header.
  61      If not, the text section starts on the next page.  */
  62   unsigned char text_includes_header;
  63
  64   /* If the text section VMA isn't specified, and we need an absolute
  65      address, use this as the default.  If we're producing a relocatable
  66      file, zero is always used.  */
  67   /* ?? Perhaps a callback would be a better choice?  Will this do anything
  68      reasonable for a format that handles multiple CPUs with different
  69      load addresses for each?  */
  70   bfd_vma default_text_vma;
  71
  72   /* Callback for setting the page and segment sizes, if they can't be
  73      trivially determined from the architecture.  */
  74   boolean (*set_sizes) PARAMS ((bfd *));
  75
  76   /* zmagic files only. For go32, the length of the exec header contributes
  77      to the size of the text section in the file for alignment purposes but
  78      does *not* get counted in the length of the text section. */
  79   unsigned char exec_header_not_counted;
  80
  81   /* A callback function to read in the dynamic symbols of an object
  82      which is dynamically linked.  This returns the number of symbols
  83      read (or -1 on error) and sets *SYMS to a buffer holding an array
  84      of external_nlist structures and *STRS and *STRSIZE to the
  85      associated string table.  (This interface works for SunOS, but
  86      can be changed if some other interface is better for some other
  87      shared library implementation).  */
  88   bfd_size_type (*read_dynamic_symbols) PARAMS ((bfd *,
  89                                                  struct external_nlist **syms,
  90                                                  char **strs,
  91                                                  bfd_size_type *strsize));
  92
  93   /* A callback function to read in the dynamic relocs of an object
  94      which is dynamically linked.  This returns the number of relocs
  95      read (or -1 on error) and sets *RELOCS to a buffer holding an
  96      array of external reloc structures (the type depends upon the
  97      type of object file).  */
  98   bfd_size_type (*read_dynamic_relocs) PARAMS ((bfd *, PTR *relocs));
  99 };
 100 #define aout_backend_info(abfd) \
 101         ((CONST struct aout_backend_data *)((abfd)->xvec->backend_data))
 102
 103 /* This is the layout in memory of a "struct exec" while we process it.
 104    All 'lengths' are given as a number of bytes.
 105    All 'alignments' are for relinkable files only;  an alignment of
 106         'n' indicates the corresponding segment must begin at an
 107         address that is a multiple of (2**n).  */
 108
 109 struct internal_exec
 110 {
 111     long a_info;                /* Magic number and flags, packed */
 112     bfd_vma a_text;             /* length of text, in bytes  */
 113     bfd_vma a_data;             /* length of data, in bytes  */
 114     bfd_vma a_bss;              /* length of uninitialized data area in mem */
 115     bfd_vma a_syms;             /* length of symbol table data in file */
 116     bfd_vma a_entry;            /* start address */
 117     bfd_vma a_trsize;           /* length of text's relocation info, in bytes */
 118     bfd_vma a_drsize;           /* length of data's relocation info, in bytes */
 119     /* Added for i960 */
 120     bfd_vma a_tload;            /* Text runtime load address */
 121     bfd_vma a_dload;            /* Data runtime load address */
 122     unsigned char a_talign;     /* Alignment of text segment */
 123     unsigned char a_dalign;     /* Alignment of data segment */
 124     unsigned char a_balign;     /* Alignment of bss segment */
 125     char a_relaxable;           /* Enough info for linker relax */
 126 };
 127
 128 /* Magic number is written
 129 < MSB        >
 130 3130292827262524232221201918171615141312111009080706050403020100
 131 < FLAGS      >< MACHINE TYPE ><  MAGIC NUMBER                  >
 132 */
 133 /* Magic number for NetBSD is
 134 <MSB         >
 135 3130292827262524232221201918171615141312111009080706050403020100
 136 < FLAGS    ><                  ><  MAGIC NUMBER                >
 137 */
 138
 139 enum machine_type {
 140   M_UNKNOWN = 0,
 141   M_68010 = 1,
 142   M_68020 = 2,
 143   M_SPARC = 3,
 144   /* skip a bunch so we don't run into any of suns numbers */
 145   M_386 = 100,
 146   M_29K = 101,          /* AMD 29000 */
 147   M_386_DYNIX = 102,    /* Sequent running dynix */
 148   M_386_NETBSD = 134,           /* NetBSD/386 binary */
 149   M_MIPS1 = 151,        /* MIPS R2000/R3000 binary */
 150   M_MIPS2 = 152,        /* MIPS R4000/R6000 binary */
 151   M_HP200 = 200,        /* HP 200 (68010) BSD binary */
 152   M_HP300 = (300 % 256), /* HP 300 (68020+68881) BSD binary */
 153   M_HPUX = (0x20c % 256)/* HP 200/300 HPUX binary */
 154 };
 155
 156 #define N_DYNAMIC(exec) ((exec).a_info & 0x80000000)
 157
 158 #ifndef N_MAGIC
 159 # define N_MAGIC(exec) ((exec).a_info & 0xffff)
 160 #endif
 161
 162 #ifndef N_MACHTYPE
 163 # define N_MACHTYPE(exec) ((enum machine_type)(((exec).a_info >> 16) & 0xff))
 164 #endif
 165
 166 #ifndef N_FLAGS
 167 # define N_FLAGS(exec) (((exec).a_info >> 24) & 0xff)
 168 #endif
 169
 170 #ifndef N_SET_INFO
 171 # define N_SET_INFO(exec, magic, type, flags) \
 172 ((exec).a_info = ((magic) & 0xffff) \
 173  | (((int)(type) & 0xff) << 16) \
 174  | (((flags) & 0xff) << 24))
 175 #endif
 176
 177 #ifndef N_SET_DYNAMIC
 178 # define N_SET_DYNAMIC(exec, dynamic) \
 179 ((exec).a_info = (dynamic) ? ((exec).a_info | 0x80000000) : \
 180 ((exec).a_info & 0x7fffffff))
 181 #endif
 182
 183 #ifndef N_SET_MAGIC
 184 # define N_SET_MAGIC(exec, magic) \
 185 ((exec).a_info = (((exec).a_info & 0xffff0000) | ((magic) & 0xffff)))
 186 #endif
 187
 188 #ifndef N_SET_MACHTYPE
 189 # define N_SET_MACHTYPE(exec, machtype) \
 190 ((exec).a_info = \
 191  ((exec).a_info&0xff00ffff) | ((((int)(machtype))&0xff) << 16))
 192 #endif
 193
 194 #ifndef N_SET_FLAGS
 195 # define N_SET_FLAGS(exec, flags) \
 196 ((exec).a_info = \
 197  ((exec).a_info&0x00ffffff) | (((flags) & 0xff) << 24))
 198 #endif
 199
 200 typedef struct aout_symbol {
 201   asymbol symbol;
 202   short desc;
 203   char other;
 204   unsigned char type;
 205 } aout_symbol_type;
 206
 207 /* The `tdata' struct for all a.out-like object file formats.
 208    Various things depend on this struct being around any time an a.out
 209    file is being handled.  An example is dbxread.c in GDB.  */
 210
 211 struct aoutdata {
 212   struct internal_exec *hdr;            /* exec file header */
 213   aout_symbol_type *symbols;            /* symtab for input bfd */
 214
 215   /* For ease, we do this */
 216   asection *textsec;
 217   asection *datasec;
 218   asection *bsssec;
 219
 220   /* We remember these offsets so that after check_file_format, we have
 221      no dependencies on the particular format of the exec_hdr.  */
 222   file_ptr sym_filepos;
 223   file_ptr str_filepos;
 224
 225   /* Size of a relocation entry in external form */
 226   unsigned reloc_entry_size;
 227
 228   /* Size of a symbol table entry in external form */
 229   unsigned symbol_entry_size;
 230
 231   /* Page size - needed for alignment of demand paged files. */
 232   unsigned long page_size;
 233
 234   /* Segment size - needed for alignment of demand paged files. */
 235   unsigned long segment_size;
 236
 237   unsigned exec_bytes_size;
 238   unsigned vma_adjusted : 1;
 239
 240   /* used when a bfd supports several highly similar formats */
 241   enum {
 242     default_format = 0,
 243     gnu_encap_format } subformat;
 244
 245   enum {
 246     undecided_magic = 0,
 247     z_magic,
 248     o_magic,
 249     n_magic } magic;
 250
 251   /* The external symbol information.  */
 252   struct external_nlist *external_syms;
 253   bfd_size_type external_sym_count;
 254   char *external_strings;
 255   bfd_size_type external_string_size;
 256   struct aout_link_hash_entry **sym_hashes;
 257
 258   /* A pointer for shared library information.  */
 259   PTR dynamic_info;
 260 };
 261
 262 struct  aout_data_struct {
 263     struct aoutdata a;
 264     struct internal_exec e;
 265 };
 266
 267 #define adata(bfd)              ((bfd)->tdata.aout_data->a)
 268 #define exec_hdr(bfd)           (adata(bfd).hdr)
 269 #define obj_aout_symbols(bfd)   (adata(bfd).symbols)
 270 #define obj_textsec(bfd)        (adata(bfd).textsec)
 271 #define obj_datasec(bfd)        (adata(bfd).datasec)
 272 #define obj_bsssec(bfd)         (adata(bfd).bsssec)
 273 #define obj_sym_filepos(bfd)    (adata(bfd).sym_filepos)
 274 #define obj_str_filepos(bfd)    (adata(bfd).str_filepos)
 275 #define obj_reloc_entry_size(bfd) (adata(bfd).reloc_entry_size)
 276 #define obj_symbol_entry_size(bfd) (adata(bfd).symbol_entry_size)
 277 #define obj_aout_subformat(bfd) (adata(bfd).subformat)
 278 #define obj_aout_external_syms(bfd) (adata(bfd).external_syms)
 279 #define obj_aout_external_sym_count(bfd) (adata(bfd).external_sym_count)
 280 #define obj_aout_external_strings(bfd) (adata(bfd).external_strings)
 281 #define obj_aout_external_string_size(bfd) (adata(bfd).external_string_size)
 282 #define obj_aout_sym_hashes(bfd) (adata(bfd).sym_hashes)
 283 #define obj_aout_dynamic_info(bfd) (adata(bfd).dynamic_info)
 284
 285 /* We take the address of the first element of an asymbol to ensure that the
 286    macro is only ever applied to an asymbol */
 287 #define aout_symbol(asymbol) ((aout_symbol_type *)(&(asymbol)->the_bfd))
 288
 289 /* Prototype declarations for functions defined in aoutx.h  */
 290
 291 boolean
 292 NAME(aout,squirt_out_relocs) PARAMS ((bfd *abfd, asection *section));
 293
 294 bfd_target *
 295 NAME(aout,some_aout_object_p) PARAMS ((bfd *abfd,
 296                         struct internal_exec *execp,
 297                         bfd_target * (*callback)(bfd *)));
 298
 299 boolean
 300 NAME(aout,mkobject) PARAMS ((bfd *abfd));
 301
 302 enum machine_type
 303 NAME(aout,machine_type) PARAMS ((enum bfd_architecture arch,
 304                                  unsigned long machine));
 305
 306 boolean
 307 NAME(aout,set_arch_mach) PARAMS ((bfd *abfd, enum bfd_architecture arch,
 308                                   unsigned long machine));
 309
 310 boolean
 311 NAME(aout,new_section_hook) PARAMS ((bfd *abfd, asection *newsect));
 312
 313 boolean
 314 NAME(aout,set_section_contents) PARAMS ((bfd *abfd, sec_ptr section,
 315                          PTR location, file_ptr offset, bfd_size_type count));
 316
 317 asymbol *
 318 NAME(aout,make_empty_symbol) PARAMS ((bfd *abfd));
 319
 320 boolean
 321 NAME(aout,slurp_symbol_table) PARAMS ((bfd *abfd));
 322
 323 boolean
 324 NAME(aout,write_syms) PARAMS ((bfd *abfd));
 325
 326 void
 327 NAME(aout,reclaim_symbol_table) PARAMS ((bfd *abfd));
 328
 329 long
 330 NAME(aout,get_symtab_upper_bound) PARAMS ((bfd *abfd));
 331
 332 long
 333 NAME(aout,get_symtab) PARAMS ((bfd *abfd, asymbol **location));
 334
 335 boolean
 336 NAME(aout,slurp_reloc_table) PARAMS ((bfd *abfd, sec_ptr asect,
 337                                       asymbol **symbols));
 338
 339 long
 340 NAME(aout,canonicalize_reloc) PARAMS ((bfd *abfd, sec_ptr section,
 341                                        arelent **relptr, asymbol **symbols));
 342
 343 long
 344 NAME(aout,get_reloc_upper_bound) PARAMS ((bfd *abfd, sec_ptr asect));
 345
 346 void
 347 NAME(aout,reclaim_reloc) PARAMS ((bfd *ignore_abfd, sec_ptr ignore));
 348
 349 alent *
 350 NAME(aout,get_lineno) PARAMS ((bfd *ignore_abfd, asymbol *ignore_symbol));
 351
 352 void
 353 NAME(aout,print_symbol) PARAMS ((bfd *ignore_abfd, PTR file,
 354                             asymbol *symbol, bfd_print_symbol_type how));
 355
 356 void
 357 NAME(aout,get_symbol_info) PARAMS ((bfd *ignore_abfd,
 358                            asymbol *symbol, symbol_info *ret));
 359
 360 boolean
 361 NAME(aout,find_nearest_line) PARAMS ((bfd *abfd, asection *section,
 362       asymbol **symbols, bfd_vma offset, CONST char **filename_ptr,
 363       CONST char **functionname_ptr, unsigned int *line_ptr));
 364
 365 int
 366 NAME(aout,sizeof_headers) PARAMS ((bfd *abfd, boolean exec));
 367
 368 boolean
 369 NAME(aout,adjust_sizes_and_vmas) PARAMS ((bfd *abfd,
 370        bfd_size_type *text_size, file_ptr *text_end));
 371
 372 void
 373 NAME(aout,swap_exec_header_in) PARAMS ((bfd *abfd,
 374        struct external_exec *raw_bytes, struct internal_exec *execp));
 375
 376 void
 377 NAME(aout,swap_exec_header_out) PARAMS ((bfd *abfd,
 378        struct internal_exec *execp, struct external_exec *raw_bytes));
 379
 380 struct bfd_link_hash_table *
 381 NAME(aout,link_hash_table_create) PARAMS ((bfd *));
 382
 383 boolean
 384 NAME(aout,link_add_symbols) PARAMS ((bfd *, struct bfd_link_info *));
 385
 386 boolean
 387 NAME(aout,final_link) PARAMS ((bfd *, struct bfd_link_info *,
 388                                void (*) (bfd *, file_ptr *, file_ptr *,
 389                                          file_ptr *)));
 390
 391 boolean
 392 NAME(aout,bfd_free_cached_info) PARAMS ((bfd *));
 393
 394 /* Prototypes for functions in stab-syms.c. */
 395
 396 CONST char *
 397 aout_stab_name PARAMS ((int code));
 398
 399 /* A.out uses the generic versions of these routines... */
 400
 401 #define aout_32_get_section_contents    _bfd_generic_get_section_contents
 402
 403 #define aout_64_get_section_contents    _bfd_generic_get_section_contents
 404 #ifndef NO_WRITE_HEADER_KLUDGE
 405 #define NO_WRITE_HEADER_KLUDGE 0
 406 #endif
 407
 408 #ifndef aout_32_bfd_is_local_label
 409 #define aout_32_bfd_is_local_label bfd_generic_is_local_label
 410 #endif
 411
 412 #ifndef WRITE_HEADERS
 413 #define WRITE_HEADERS(abfd, execp)                                            \
 414       {                                                                       \
 415         bfd_size_type text_size; /* dummy vars */                             \
 416         file_ptr text_end;                                                    \
 417         if (adata(abfd).magic == undecided_magic)                             \
 418           NAME(aout,adjust_sizes_and_vmas) (abfd, &text_size, &text_end);     \
 419                                                                               \
 420         execp->a_syms = bfd_get_symcount (abfd) * EXTERNAL_NLIST_SIZE;        \
 421         execp->a_entry = bfd_get_start_address (abfd);                        \
 422                                                                               \
 423         execp->a_trsize = ((obj_textsec (abfd)->reloc_count) *                \
 424                            obj_reloc_entry_size (abfd));                      \
 425         execp->a_drsize = ((obj_datasec (abfd)->reloc_count) *                \
 426                            obj_reloc_entry_size (abfd));                      \
 427         NAME(aout,swap_exec_header_out) (abfd, execp, &exec_bytes);           \
 428                                                                               \
 429         if (bfd_seek (abfd, (file_ptr) 0, SEEK_SET) != 0) return false;       \
 430         if (bfd_write ((PTR) &exec_bytes, 1, EXEC_BYTES_SIZE, abfd)           \
 431             != EXEC_BYTES_SIZE)                                               \
 432           return false;                                                       \
 433         /* Now write out reloc info, followed by syms and strings */          \
 434                                                                               \
 435         if (bfd_get_outsymbols (abfd) != (asymbol **) NULL                    \
 436             && bfd_get_symcount (abfd) != 0)                                  \
 437             {                                                                 \
 438               if (bfd_seek (abfd, (file_ptr)(N_SYMOFF(*execp)), SEEK_SET)     \
 439                   != 0)                                                       \
 440                 return false;                                                 \
 441                                                                               \
 442               if (! NAME(aout,write_syms)(abfd)) return false;                \
 443                                                                               \
 444               if (bfd_seek (abfd, (file_ptr)(N_TRELOFF(*execp)), SEEK_SET)    \
 445                   != 0)                                                       \
 446                 return false;                                                 \
 447                                                                               \
 448               if (!NAME(aout,squirt_out_relocs) (abfd, obj_textsec (abfd)))   \
 449                 return false;                                                 \
 450               if (bfd_seek (abfd, (file_ptr)(N_DRELOFF(*execp)), SEEK_SET)    \
 451                   != 0)                                                       \
 452                 return false;                                                 \
 453                                                                               \
 454               if (!NAME(aout,squirt_out_relocs)(abfd, obj_datasec (abfd)))    \
 455                 return false;                                                 \
 456             }                                                                 \
 457       }
 458 #endif