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