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 it isused in parameter lists, which
  48    have weird scope.  */
  49 struct external_exec;
  50
  51 /* Back-end information for various a.out targets.  */
  52 struct aout_backend_data
  53 {
  54   /* Are ZMAGIC files mapped contiguously?  If so, the text section may
  55      need more padding, if the segment size (granularity for memory access
  56      control) is larger than the page size.  */
  57   unsigned char zmagic_mapped_contiguous;
  58   /* If this flag is set, ZMAGIC/NMAGIC file headers get mapped in with the
  59      text section, which starts immediately after the file header.
  60      If not, the text section starts on the next page.  */
  61   unsigned char text_includes_header;
  62
  63   /* If the text section VMA isn't specified, and we need an absolute
  64      address, use this as the default.  If we're producing a relocatable
  65      file, zero is always used.  */
  66   /* ?? Perhaps a callback would be a better choice?  Will this do anything
  67      reasonable for a format that handles multiple CPUs with different
  68      load addresses for each?  */
  69   bfd_vma default_text_vma;
  70
  71   /* Callback for setting the page and segment sizes, if they can't be
  72      trivially determined from the architecture.  */
  73   boolean (*set_sizes) PARAMS ((bfd *));
  74
  75   /* zmagic files only. For go32, the length of the exec header contributes
  76      to the size of the text section in the file for alignment purposes but
  77      does *not* get counted in the length of the text section. */
  78   unsigned char exec_header_not_counted;
  79 };
  80 #define aout_backend_info(abfd) \
  81         ((CONST struct aout_backend_data *)((abfd)->xvec->backend_data))
  82
  83 /* This is the layout in memory of a "struct exec" while we process it.
  84    All 'lengths' are given as a number of bytes.
  85    All 'alignments' are for relinkable files only;  an alignment of
  86         'n' indicates the corresponding segment must begin at an
  87         address that is a multiple of (2**n).  */
  88
  89 struct internal_exec
  90 {
  91     long a_info;                /* Magic number and flags, packed */
  92     bfd_vma a_text;             /* length of text, in bytes  */
  93     bfd_vma a_data;             /* length of data, in bytes  */
  94     bfd_vma a_bss;              /* length of uninitialized data area in mem */
  95     bfd_vma a_syms;             /* length of symbol table data in file */
  96     bfd_vma a_entry;            /* start address */
  97     bfd_vma a_trsize;           /* length of text's relocation info, in bytes */
  98     bfd_vma a_drsize;           /* length of data's relocation info, in bytes */
  99     /* Added for i960 */
 100     bfd_vma a_tload;            /* Text runtime load address */
 101     bfd_vma a_dload;            /* Data runtime load address */
 102     unsigned char a_talign;     /* Alignment of text segment */
 103     unsigned char a_dalign;     /* Alignment of data segment */
 104     unsigned char a_balign;     /* Alignment of bss segment */
 105     char a_relaxable;           /* Enough info for linker relax */
 106 };
 107
 108 /* Magic number is written
 109 < MSB        >
 110 3130292827262524232221201918171615141312111009080706050403020100
 111 < FLAGS      >< MACHINE TYPE ><  MAGIC NUMBER                  >
 112 */
 113 /* Magic number for NetBSD is
 114 <MSB         >
 115 3130292827262524232221201918171615141312111009080706050403020100
 116 < FLAGS    ><                  ><  MAGIC NUMBER                >
 117 */
 118
 119 enum machine_type {
 120   M_UNKNOWN = 0,
 121   M_68010 = 1,
 122   M_68020 = 2,
 123   M_SPARC = 3,
 124   /* skip a bunch so we don't run into any of suns numbers */
 125   M_386 = 100,
 126   M_29K = 101,          /* AMD 29000 */
 127   M_386_DYNIX = 102,    /* Sequent running dynix */
 128   M_386_NETBSD = 134,           /* NetBSD/386 binary */
 129   M_MIPS1 = 151,        /* MIPS R2000/R3000 binary */
 130   M_MIPS2 = 152,        /* MIPS R4000/R6000 binary */
 131   M_HP200 = 200,        /* HP 200 (68010) BSD binary */
 132   M_HP300 = (300 % 256), /* HP 300 (68020+68881) BSD binary */
 133   M_HPUX = (0x20c % 256)/* HP 200/300 HPUX binary */
 134 };
 135
 136 #define N_DYNAMIC(exec) ((exec).a_info & 0x8000000)
 137
 138 #ifndef N_MAGIC
 139 # define N_MAGIC(exec) ((exec).a_info & 0xffff)
 140 #endif
 141
 142 #ifndef N_MACHTYPE
 143 # define N_MACHTYPE(exec) ((enum machine_type)(((exec).a_info >> 16) & 0xff))
 144 #endif
 145
 146 #ifndef N_FLAGS
 147 # define N_FLAGS(exec) (((exec).a_info >> 24) & 0xff)
 148 #endif
 149
 150 #ifndef N_SET_INFO
 151 # define N_SET_INFO(exec, magic, type, flags) \
 152 ((exec).a_info = ((magic) & 0xffff) \
 153  | (((int)(type) & 0xff) << 16) \
 154  | (((flags) & 0xff) << 24))
 155 #endif
 156
 157 #ifndef N_SET_MAGIC
 158 # define N_SET_MAGIC(exec, magic) \
 159 ((exec).a_info = (((exec).a_info & 0xffff0000) | ((magic) & 0xffff)))
 160 #endif
 161
 162 #ifndef N_SET_MACHTYPE
 163 # define N_SET_MACHTYPE(exec, machtype) \
 164 ((exec).a_info = \
 165  ((exec).a_info&0xff00ffff) | ((((int)(machtype))&0xff) << 16))
 166 #endif
 167
 168 #ifndef N_SET_FLAGS
 169 # define N_SET_FLAGS(exec, flags) \
 170 ((exec).a_info = \
 171  ((exec).a_info&0x00ffffff) | (((flags) & 0xff) << 24))
 172 #endif
 173
 174 typedef struct aout_symbol {
 175   asymbol symbol;
 176   short desc;
 177   char other;
 178   unsigned char type;
 179 } aout_symbol_type;
 180
 181 /* The `tdata' struct for all a.out-like object file formats.
 182    Various things depend on this struct being around any time an a.out
 183    file is being handled.  An example is dbxread.c in GDB.  */
 184
 185 struct aoutdata {
 186   struct internal_exec *hdr;            /* exec file header */
 187   aout_symbol_type *symbols;            /* symtab for input bfd */
 188
 189   /* For ease, we do this */
 190   asection *textsec;
 191   asection *datasec;
 192   asection *bsssec;
 193
 194   /* We remember these offsets so that after check_file_format, we have
 195      no dependencies on the particular format of the exec_hdr.  */
 196   file_ptr sym_filepos;
 197   file_ptr str_filepos;
 198
 199   /* Size of a relocation entry in external form */
 200   unsigned reloc_entry_size;
 201
 202   /* Size of a symbol table entry in external form */
 203   unsigned symbol_entry_size;
 204
 205   /* Page size - needed for alignment of demand paged files. */
 206   unsigned long page_size;
 207
 208   /* Segment size - needed for alignment of demand paged files. */
 209   unsigned long segment_size;
 210
 211   unsigned exec_bytes_size;
 212   unsigned vma_adjusted : 1;
 213
 214   /* used when a bfd supports several highly similar formats */
 215   enum {
 216     default_format = 0,
 217     gnu_encap_format } subformat;
 218
 219   enum {
 220     undecided_magic = 0,
 221     z_magic,
 222     o_magic,
 223     n_magic } magic;
 224
 225   /* The external symbol information.  */
 226   struct external_nlist *external_syms;
 227   bfd_size_type external_sym_count;
 228   char *external_strings;
 229   struct aout_link_hash_entry **sym_hashes;
 230 };
 231
 232 struct  aout_data_struct {
 233     struct aoutdata a;
 234     struct internal_exec e;
 235 };
 236
 237 #define adata(bfd)              ((bfd)->tdata.aout_data->a)
 238 #define exec_hdr(bfd)           (adata(bfd).hdr)
 239 #define obj_aout_symbols(bfd)   (adata(bfd).symbols)
 240 #define obj_textsec(bfd)        (adata(bfd).textsec)
 241 #define obj_datasec(bfd)        (adata(bfd).datasec)
 242 #define obj_bsssec(bfd)         (adata(bfd).bsssec)
 243 #define obj_sym_filepos(bfd)    (adata(bfd).sym_filepos)
 244 #define obj_str_filepos(bfd)    (adata(bfd).str_filepos)
 245 #define obj_reloc_entry_size(bfd) (adata(bfd).reloc_entry_size)
 246 #define obj_symbol_entry_size(bfd) (adata(bfd).symbol_entry_size)
 247 #define obj_aout_subformat(bfd) (adata(bfd).subformat)
 248 #define obj_aout_external_syms(bfd) (adata(bfd).external_syms)
 249 #define obj_aout_external_sym_count(bfd) (adata(bfd).external_sym_count)
 250 #define obj_aout_external_strings(bfd) (adata(bfd).external_strings)
 251 #define obj_aout_sym_hashes(bfd) (adata(bfd).sym_hashes)
 252
 253 /* We take the address of the first element of an asymbol to ensure that the
 254    macro is only ever applied to an asymbol */
 255 #define aout_symbol(asymbol) ((aout_symbol_type *)(&(asymbol)->the_bfd))
 256
 257 /* Prototype declarations for functions defined in aoutx.h  */
 258
 259 boolean
 260 NAME(aout,squirt_out_relocs) PARAMS ((bfd *abfd, asection *section));
 261
 262 bfd_target *
 263 NAME(aout,some_aout_object_p) PARAMS ((bfd *abfd,
 264                         struct internal_exec *execp,
 265                         bfd_target * (*callback)(bfd *)));
 266
 267 boolean
 268 NAME(aout,mkobject) PARAMS ((bfd *abfd));
 269
 270 enum machine_type
 271 NAME(aout,machine_type) PARAMS ((enum bfd_architecture arch,
 272                                  unsigned long machine));
 273
 274 boolean
 275 NAME(aout,set_arch_mach) PARAMS ((bfd *abfd, enum bfd_architecture arch,
 276                                   unsigned long machine));
 277
 278 boolean
 279 NAME(aout,new_section_hook) PARAMS ((bfd *abfd, asection *newsect));
 280
 281 boolean
 282 NAME(aout,set_section_contents) PARAMS ((bfd *abfd, sec_ptr section,
 283                          PTR location, file_ptr offset, bfd_size_type count));
 284
 285 asymbol *
 286 NAME(aout,make_empty_symbol) PARAMS ((bfd *abfd));
 287
 288 boolean
 289 NAME(aout,slurp_symbol_table) PARAMS ((bfd *abfd));
 290
 291 boolean
 292 NAME(aout,write_syms) PARAMS ((bfd *abfd));
 293
 294 void
 295 NAME(aout,reclaim_symbol_table) PARAMS ((bfd *abfd));
 296
 297 unsigned int
 298 NAME(aout,get_symtab_upper_bound) PARAMS ((bfd *abfd));
 299
 300 unsigned int
 301 NAME(aout,get_symtab) PARAMS ((bfd *abfd, asymbol **location));
 302
 303 boolean
 304 NAME(aout,slurp_reloc_table) PARAMS ((bfd *abfd, sec_ptr asect,
 305                                       asymbol **symbols));
 306
 307 unsigned int
 308 NAME(aout,canonicalize_reloc) PARAMS ((bfd *abfd, sec_ptr section,
 309                                        arelent **relptr, asymbol **symbols));
 310
 311 unsigned int
 312 NAME(aout,get_reloc_upper_bound) PARAMS ((bfd *abfd, sec_ptr asect));
 313
 314 void
 315 NAME(aout,reclaim_reloc) PARAMS ((bfd *ignore_abfd, sec_ptr ignore));
 316
 317 alent *
 318 NAME(aout,get_lineno) PARAMS ((bfd *ignore_abfd, asymbol *ignore_symbol));
 319
 320 void
 321 NAME(aout,print_symbol) PARAMS ((bfd *ignore_abfd, PTR file,
 322                             asymbol *symbol, bfd_print_symbol_type how));
 323
 324 void
 325 NAME(aout,get_symbol_info) PARAMS ((bfd *ignore_abfd,
 326                            asymbol *symbol, symbol_info *ret));
 327
 328 boolean
 329 NAME(aout,close_and_cleanup) PARAMS ((bfd *abfd));
 330
 331 boolean
 332 NAME(aout,find_nearest_line) PARAMS ((bfd *abfd, asection *section,
 333       asymbol **symbols, bfd_vma offset, CONST char **filename_ptr,
 334       CONST char **functionname_ptr, unsigned int *line_ptr));
 335
 336 int
 337 NAME(aout,sizeof_headers) PARAMS ((bfd *abfd, boolean exec));
 338
 339 boolean
 340 NAME(aout,adjust_sizes_and_vmas) PARAMS ((bfd *abfd,
 341        bfd_size_type *text_size, file_ptr *text_end));
 342
 343 void
 344 NAME(aout,swap_exec_header_in) PARAMS ((bfd *abfd,
 345        struct external_exec *raw_bytes, struct internal_exec *execp));
 346
 347 void
 348 NAME(aout,swap_exec_header_out) PARAMS ((bfd *abfd,
 349        struct internal_exec *execp, struct external_exec *raw_bytes));
 350
 351 struct bfd_link_hash_table *
 352 NAME(aout,link_hash_table_create) PARAMS ((bfd *));
 353
 354 boolean
 355 NAME(aout,link_add_symbols) PARAMS ((bfd *, struct bfd_link_info *));
 356
 357 boolean
 358 NAME(aout,final_link) PARAMS ((bfd *, struct bfd_link_info *,
 359                                void (*) (bfd *, file_ptr *, file_ptr *,
 360                                          file_ptr *)));
 361
 362 /* Prototypes for functions in stab-syms.c. */
 363
 364 CONST char *
 365 aout_stab_name PARAMS ((int code));
 366
 367 /* A.out uses the generic versions of these routines... */
 368
 369 #define aout_32_get_section_contents    bfd_generic_get_section_contents
 370 #define aout_32_close_and_cleanup       bfd_generic_close_and_cleanup
 371
 372 #define aout_64_get_section_contents    bfd_generic_get_section_contents
 373 #define aout_64_close_and_cleanup       bfd_generic_close_and_cleanup
 374 #ifndef NO_WRITE_HEADER_KLUDGE
 375 #define NO_WRITE_HEADER_KLUDGE 0
 376 #endif
 377
 378 #ifndef WRITE_HEADERS
 379 #define WRITE_HEADERS(abfd, execp)                                            \
 380       {                                                                       \
 381         bfd_size_type text_size; /* dummy vars */                             \
 382         file_ptr text_end;                                                    \
 383         if (adata(abfd).magic == undecided_magic)                             \
 384           NAME(aout,adjust_sizes_and_vmas) (abfd, &text_size, &text_end);     \
 385                                                                               \
 386         execp->a_syms = bfd_get_symcount (abfd) * EXTERNAL_NLIST_SIZE;        \
 387         execp->a_entry = bfd_get_start_address (abfd);                        \
 388                                                                               \
 389         execp->a_trsize = ((obj_textsec (abfd)->reloc_count) *                \
 390                            obj_reloc_entry_size (abfd));                      \
 391         execp->a_drsize = ((obj_datasec (abfd)->reloc_count) *                \
 392                            obj_reloc_entry_size (abfd));                      \
 393         NAME(aout,swap_exec_header_out) (abfd, execp, &exec_bytes);           \
 394                                                                               \
 395         bfd_seek (abfd, (file_ptr) 0, SEEK_SET);                              \
 396         bfd_write ((PTR) &exec_bytes, 1, EXEC_BYTES_SIZE, abfd);              \
 397         /* Now write out reloc info, followed by syms and strings */          \
 398                                                                               \
 399         if (bfd_get_outsymbols (abfd) != (asymbol **) NULL                    \
 400             && bfd_get_symcount (abfd) != 0)                                  \
 401             {                                                                 \
 402               bfd_seek (abfd, (file_ptr)(N_SYMOFF(*execp)), SEEK_SET);        \
 403                                                                               \
 404               if (! NAME(aout,write_syms)(abfd)) return false;                \
 405                                                                               \
 406               bfd_seek (abfd, (file_ptr)(N_TRELOFF(*execp)), SEEK_SET);       \
 407                                                                               \
 408               if (!NAME(aout,squirt_out_relocs) (abfd, obj_textsec (abfd))) return false; \
 409               bfd_seek (abfd, (file_ptr)(N_DRELOFF(*execp)), SEEK_SET);       \
 410                                                                               \
 411               if (!NAME(aout,squirt_out_relocs)(abfd, obj_datasec (abfd))) return false; \
 412             }                                                                 \
 413       }
 414 #endif