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 these types at file level, since they are used in parameter
  48    lists, which have wierd scope.  */
  49 struct external_exec;
  50 struct internal_exec;
  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 #define aout_backend_info(abfd) \
  82         ((CONST struct aout_backend_data *)((abfd)->xvec->backend_data))
  83
  84 /* This is the layout in memory of a "struct exec" while we process it.
  85    All 'lengths' are given as a number of bytes.
  86    All 'alignments' are for relinkable files only;  an alignment of
  87         'n' indicates the corresponding segment must begin at an
  88         address that is a multiple of (2**n).  */
  89
  90 struct internal_exec
  91 {
  92     long a_info;                /* Magic number and flags, packed */
  93     bfd_vma a_text;             /* length of text, in bytes  */
  94     bfd_vma a_data;             /* length of data, in bytes  */
  95     bfd_vma a_bss;              /* length of uninitialized data area in mem */
  96     bfd_vma a_syms;             /* length of symbol table data in file */
  97     bfd_vma a_entry;            /* start address */
  98     bfd_vma a_trsize;           /* length of text's relocation info, in bytes */
  99     bfd_vma a_drsize;           /* length of data's relocation info, in bytes */
 100     /* Added for i960 */
 101     bfd_vma a_tload;            /* Text runtime load address */
 102     bfd_vma a_dload;            /* Data runtime load address */
 103     unsigned char a_talign;     /* Alignment of text segment */
 104     unsigned char a_dalign;     /* Alignment of data segment */
 105     unsigned char a_balign;     /* Alignment of bss segment */
 106     char a_relaxable;           /* Enough info for linker relax */
 107 };
 108
 109 /* Magic number is written
 110 < MSB        >
 111 3130292827262524232221201918171615141312111009080706050403020100
 112 < FLAGS      >< MACHINE TYPE ><  MAGIC NUMBER                  >
 113 */
 114 /* Magic number for NetBSD is
 115 <MSB         >
 116 3130292827262524232221201918171615141312111009080706050403020100
 117 < FLAGS    ><                  ><  MAGIC NUMBER                >
 118 */
 119
 120 enum machine_type {
 121   M_UNKNOWN = 0,
 122   M_68010 = 1,
 123   M_68020 = 2,
 124   M_SPARC = 3,
 125   /* skip a bunch so we don't run into any of suns numbers */
 126   M_386 = 100,
 127   M_29K = 101,          /* AMD 29000 */
 128   M_386_DYNIX = 102,    /* Sequent running dynix */
 129   M_386_NETBSD = 134,           /* NetBSD/386 binary */
 130   M_MIPS1 = 151,        /* MIPS R2000/R3000 binary */
 131   M_MIPS2 = 152,        /* MIPS R4000/R6000 binary */
 132   M_HP200 = 200,        /* HP 200 (68010) BSD binary */
 133   M_HP300 = (300 % 256), /* HP 300 (68020+68881) BSD binary */
 134   M_HPUX = (0x20c % 256)/* HP 200/300 HPUX binary */
 135 };
 136
 137 #define N_DYNAMIC(exec) ((exec).a_info & 0x8000000)
 138
 139 #ifndef N_MAGIC
 140 # define N_MAGIC(exec) ((exec).a_info & 0xffff)
 141 #endif
 142
 143 #ifndef N_MACHTYPE
 144 # define N_MACHTYPE(exec) ((enum machine_type)(((exec).a_info >> 16) & 0xff))
 145 #endif
 146
 147 #ifndef N_FLAGS
 148 # define N_FLAGS(exec) (((exec).a_info >> 24) & 0xff)
 149 #endif
 150
 151 #ifndef N_SET_INFO
 152 # define N_SET_INFO(exec, magic, type, flags) \
 153 ((exec).a_info = ((magic) & 0xffff) \
 154  | (((int)(type) & 0xff) << 16) \
 155  | (((flags) & 0xff) << 24))
 156 #endif
 157
 158 #ifndef N_SET_MAGIC
 159 # define N_SET_MAGIC(exec, magic) \
 160 ((exec).a_info = (((exec).a_info & 0xffff0000) | ((magic) & 0xffff)))
 161 #endif
 162
 163 #ifndef N_SET_MACHTYPE
 164 # define N_SET_MACHTYPE(exec, machtype) \
 165 ((exec).a_info = \
 166  ((exec).a_info&0xff00ffff) | ((((int)(machtype))&0xff) << 16))
 167 #endif
 168
 169 #ifndef N_SET_FLAGS
 170 # define N_SET_FLAGS(exec, flags) \
 171 ((exec).a_info = \
 172  ((exec).a_info&0x00ffffff) | (((flags) & 0xff) << 24))
 173 #endif
 174
 175 typedef struct aout_symbol {
 176   asymbol symbol;
 177   short desc;
 178   char other;
 179   unsigned char type;
 180 } aout_symbol_type;
 181
 182 /* The `tdata' struct for all a.out-like object file formats.
 183    Various things depend on this struct being around any time an a.out
 184    file is being handled.  An example is dbxread.c in GDB.  */
 185
 186 struct aoutdata {
 187   struct internal_exec *hdr;            /* exec file header */
 188   aout_symbol_type *symbols;            /* symtab for input bfd */
 189
 190   /* For ease, we do this */
 191   asection *textsec;
 192   asection *datasec;
 193   asection *bsssec;
 194
 195   /* We remember these offsets so that after check_file_format, we have
 196      no dependencies on the particular format of the exec_hdr.  */
 197   file_ptr sym_filepos;
 198   file_ptr str_filepos;
 199
 200   /* Size of a relocation entry in external form */
 201   unsigned reloc_entry_size;
 202
 203   /* Size of a symbol table entry in external form */
 204   unsigned symbol_entry_size;
 205
 206   /* Page size - needed for alignment of demand paged files. */
 207   unsigned long page_size;
 208
 209   /* Segment size - needed for alignment of demand paged files. */
 210   unsigned long segment_size;
 211
 212   unsigned exec_bytes_size;
 213   unsigned vma_adjusted : 1;
 214
 215   /* used when a bfd supports several highly similar formats */
 216   enum {
 217     default_format = 0,
 218     gnu_encap_format } subformat;
 219
 220   enum {
 221     undecided_magic = 0,
 222     z_magic,
 223     o_magic,
 224     n_magic } magic;
 225
 226   /* The external symbol information.  */
 227   struct external_nlist *external_syms;
 228   bfd_size_type external_sym_count;
 229   char *external_strings;
 230   struct aout_link_hash_entry **sym_hashes;
 231 };
 232
 233 struct  aout_data_struct {
 234     struct aoutdata a;
 235     struct internal_exec e;
 236 };
 237
 238 #define adata(bfd)              ((bfd)->tdata.aout_data->a)
 239 #define exec_hdr(bfd)           (adata(bfd).hdr)
 240 #define obj_aout_symbols(bfd)   (adata(bfd).symbols)
 241 #define obj_textsec(bfd)        (adata(bfd).textsec)
 242 #define obj_datasec(bfd)        (adata(bfd).datasec)
 243 #define obj_bsssec(bfd)         (adata(bfd).bsssec)
 244 #define obj_sym_filepos(bfd)    (adata(bfd).sym_filepos)
 245 #define obj_str_filepos(bfd)    (adata(bfd).str_filepos)
 246 #define obj_reloc_entry_size(bfd) (adata(bfd).reloc_entry_size)
 247 #define obj_symbol_entry_size(bfd) (adata(bfd).symbol_entry_size)
 248 #define obj_aout_subformat(bfd) (adata(bfd).subformat)
 249 #define obj_aout_external_syms(bfd) (adata(bfd).external_syms)
 250 #define obj_aout_external_sym_count(bfd) (adata(bfd).external_sym_count)
 251 #define obj_aout_external_strings(bfd) (adata(bfd).external_strings)
 252 #define obj_aout_sym_hashes(bfd) (adata(bfd).sym_hashes)
 253
 254 /* We take the address of the first element of an asymbol to ensure that the
 255    macro is only ever applied to an asymbol */
 256 #define aout_symbol(asymbol) ((aout_symbol_type *)(&(asymbol)->the_bfd))
 257
 258 /* Prototype declarations for functions defined in aoutx.h  */
 259
 260 boolean
 261 NAME(aout,squirt_out_relocs) PARAMS ((bfd *abfd, asection *section));
 262
 263 bfd_target *
 264 NAME(aout,some_aout_object_p) PARAMS ((bfd *abfd,
 265                         struct internal_exec *execp,
 266                         bfd_target * (*callback)(bfd *)));
 267
 268 boolean
 269 NAME(aout,mkobject) PARAMS ((bfd *abfd));
 270
 271 enum machine_type
 272 NAME(aout,machine_type) PARAMS ((enum bfd_architecture arch,
 273                                  unsigned long machine));
 274
 275 boolean
 276 NAME(aout,set_arch_mach) PARAMS ((bfd *abfd, enum bfd_architecture arch,
 277                                   unsigned long machine));
 278
 279 boolean
 280 NAME(aout,new_section_hook) PARAMS ((bfd *abfd, asection *newsect));
 281
 282 boolean
 283 NAME(aout,set_section_contents) PARAMS ((bfd *abfd, sec_ptr section,
 284                          PTR location, file_ptr offset, bfd_size_type count));
 285
 286 asymbol *
 287 NAME(aout,make_empty_symbol) PARAMS ((bfd *abfd));
 288
 289 boolean
 290 NAME(aout,slurp_symbol_table) PARAMS ((bfd *abfd));
 291
 292 boolean
 293 NAME(aout,write_syms) PARAMS ((bfd *abfd));
 294
 295 void
 296 NAME(aout,reclaim_symbol_table) PARAMS ((bfd *abfd));
 297
 298 unsigned int
 299 NAME(aout,get_symtab_upper_bound) PARAMS ((bfd *abfd));
 300
 301 unsigned int
 302 NAME(aout,get_symtab) PARAMS ((bfd *abfd, asymbol **location));
 303
 304 boolean
 305 NAME(aout,slurp_reloc_table) PARAMS ((bfd *abfd, sec_ptr asect,
 306                                       asymbol **symbols));
 307
 308 unsigned int
 309 NAME(aout,canonicalize_reloc) PARAMS ((bfd *abfd, sec_ptr section,
 310                                        arelent **relptr, asymbol **symbols));
 311
 312 unsigned int
 313 NAME(aout,get_reloc_upper_bound) PARAMS ((bfd *abfd, sec_ptr asect));
 314
 315 void
 316 NAME(aout,reclaim_reloc) PARAMS ((bfd *ignore_abfd, sec_ptr ignore));
 317
 318 alent *
 319 NAME(aout,get_lineno) PARAMS ((bfd *ignore_abfd, asymbol *ignore_symbol));
 320
 321 void
 322 NAME(aout,print_symbol) PARAMS ((bfd *ignore_abfd, PTR file,
 323                             asymbol *symbol, bfd_print_symbol_type how));
 324
 325 void
 326 NAME(aout,get_symbol_info) PARAMS ((bfd *ignore_abfd,
 327                            asymbol *symbol, symbol_info *ret));
 328
 329 boolean
 330 NAME(aout,close_and_cleanup) PARAMS ((bfd *abfd));
 331
 332 boolean
 333 NAME(aout,find_nearest_line) PARAMS ((bfd *abfd, asection *section,
 334       asymbol **symbols, bfd_vma offset, CONST char **filename_ptr,
 335       CONST char **functionname_ptr, unsigned int *line_ptr));
 336
 337 int
 338 NAME(aout,sizeof_headers) PARAMS ((bfd *abfd, boolean exec));
 339
 340 boolean
 341 NAME(aout,adjust_sizes_and_vmas) PARAMS ((bfd *abfd,
 342        bfd_size_type *text_size, file_ptr *text_end));
 343
 344 void
 345 NAME(aout,swap_exec_header_in) PARAMS ((bfd *abfd,
 346        struct external_exec *raw_bytes, struct internal_exec *execp));
 347
 348 void
 349 NAME(aout,swap_exec_header_out) PARAMS ((bfd *abfd,
 350        struct internal_exec *execp, struct external_exec *raw_bytes));
 351
 352 struct bfd_link_hash_table *
 353 NAME(aout,link_hash_table_create) PARAMS ((bfd *));
 354
 355 boolean
 356 NAME(aout,link_add_symbols) PARAMS ((bfd *, struct bfd_link_info *));
 357
 358 boolean
 359 NAME(aout,final_link) PARAMS ((bfd *, struct bfd_link_info *,
 360                                void (*) (bfd *, file_ptr *, file_ptr *,
 361                                          file_ptr *)));
 362
 363 /* Prototypes for functions in stab-syms.c. */
 364
 365 CONST char *
 366 aout_stab_name PARAMS ((int code));
 367
 368 /* A.out uses the generic versions of these routines... */
 369
 370 #define aout_32_get_section_contents    bfd_generic_get_section_contents
 371 #define aout_32_close_and_cleanup       bfd_generic_close_and_cleanup
 372
 373 #define aout_64_get_section_contents    bfd_generic_get_section_contents
 374 #define aout_64_close_and_cleanup       bfd_generic_close_and_cleanup
 375 #ifndef NO_WRITE_HEADER_KLUDGE
 376 #define NO_WRITE_HEADER_KLUDGE 0
 377 #endif
 378
 379 #ifndef WRITE_HEADERS
 380 #define WRITE_HEADERS(abfd, execp)                                            \
 381       {                                                                       \
 382         bfd_size_type text_size; /* dummy vars */                             \
 383         file_ptr text_end;                                                    \
 384         if (adata(abfd).magic == undecided_magic)                             \
 385           NAME(aout,adjust_sizes_and_vmas) (abfd, &text_size, &text_end);     \
 386                                                                               \
 387         execp->a_syms = bfd_get_symcount (abfd) * EXTERNAL_NLIST_SIZE;        \
 388         execp->a_entry = bfd_get_start_address (abfd);                        \
 389                                                                               \
 390         execp->a_trsize = ((obj_textsec (abfd)->reloc_count) *                \
 391                            obj_reloc_entry_size (abfd));                      \
 392         execp->a_drsize = ((obj_datasec (abfd)->reloc_count) *                \
 393                            obj_reloc_entry_size (abfd));                      \
 394         NAME(aout,swap_exec_header_out) (abfd, execp, &exec_bytes);           \
 395                                                                               \
 396         bfd_seek (abfd, (file_ptr) 0, SEEK_SET);                              \
 397         bfd_write ((PTR) &exec_bytes, 1, EXEC_BYTES_SIZE, abfd);              \
 398         /* Now write out reloc info, followed by syms and strings */          \
 399                                                                               \
 400         if (bfd_get_outsymbols (abfd) != (asymbol **) NULL                    \
 401             && bfd_get_symcount (abfd) != 0)                                  \
 402             {                                                                 \
 403               bfd_seek (abfd, (file_ptr)(N_SYMOFF(*execp)), SEEK_SET);        \
 404                                                                               \
 405               if (! NAME(aout,write_syms)(abfd)) return false;                \
 406                                                                               \
 407               bfd_seek (abfd, (file_ptr)(N_TRELOFF(*execp)), SEEK_SET);       \
 408                                                                               \
 409               if (!NAME(aout,squirt_out_relocs) (abfd, obj_textsec (abfd))) return false; \
 410               bfd_seek (abfd, (file_ptr)(N_DRELOFF(*execp)), SEEK_SET);       \
 411                                                                               \
 412               if (!NAME(aout,squirt_out_relocs)(abfd, obj_datasec (abfd))) return false; \
 413             }                                                                 \
 414       }
 415 #endif