bfd/libaout.h

   1 /* BFD back-end data structures for a.out (and similar) files.
   2    Copyright (C) 1990-1991 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 /* $Id$ */
  26
  27 #ifdef __STDC__
  28 #define CAT3(a,b,c) a##b##c
  29 #else
  30 #define CAT3(a,b,c) a/**/b/**/c
  31 #endif
  32
  33 /* Parameterize the a.out code based on whether it is being built
  34    for a 32-bit architecture or a 64-bit architecture.  */
  35 #if ARCH_SIZE==64
  36 #define GET_WORD bfd_h_get_64
  37 #define GET_SWORD (int64_type)GET_WORD
  38 #define PUT_WORD bfd_h_put_64
  39 #define NAME(x,y) CAT3(x,_64_,y)
  40 #define JNAME(x) CAT(x,_64)
  41 #define BYTES_IN_WORD 8
  42 #else
  43 #define GET_WORD bfd_h_get_32
  44 #define GET_SWORD (int32_type)GET_WORD
  45 #define PUT_WORD bfd_h_put_32
  46 #define NAME(x,y) CAT3(x,_32_,y)
  47 #define JNAME(x) CAT(x,_32)
  48 #define BYTES_IN_WORD 4
  49 #endif
  50
  51 /* Declare these types at file level, since they are used in parameter
  52    lists, which have wierd scope.  */
  53 struct external_exec;
  54 struct internal_exec;
  55
  56 /* This is the layout in memory of a "struct exec" while we process it.
  57    All 'lengths' are given as a number of bytes.
  58    All 'alignments' are for relinkable files only;  an alignment of
  59         'n' indicates the corresponding segment must begin at an
  60         address that is a multiple of (2**n).  */
  61
  62 struct internal_exec
  63 {
  64     long a_info;                /* Magic number and flags, packed */
  65     bfd_vma a_text;             /* length of text, in bytes  */
  66     bfd_vma a_data;             /* length of data, in bytes  */
  67     bfd_vma a_bss;              /* length of uninitialized data area in mem */
  68     bfd_vma a_syms;             /* length of symbol table data in file */
  69     bfd_vma a_entry;            /* start address */
  70     bfd_vma a_trsize;           /* length of text's relocation info, in bytes */
  71     bfd_vma a_drsize;           /* length of data's relocation info, in bytes */
  72     /* Added for i960 */
  73     bfd_vma a_tload;            /* Text runtime load address */
  74     bfd_vma a_dload;            /* Data runtime load address */
  75     unsigned char a_talign;     /* Alignment of text segment */
  76     unsigned char a_dalign;     /* Alignment of data segment */
  77     unsigned char a_balign;     /* Alignment of bss segment */
  78 };
  79
  80 /* Magic number is written
  81 < MSB        >
  82 3130292827262524232221201918171615141312111009080706050403020100
  83 < FLAGS      >< MACHINE TYPE ><  MAGIC NUMBER                  >
  84 */
  85 enum machine_type {
  86   M_UNKNOWN = 0,
  87   M_68010 = 1,
  88   M_68020 = 2,
  89   M_SPARC = 3,
  90   /* skip a bunch so we dont run into any of suns numbers */
  91   M_386 = 100,
  92   M_29K = 101,
  93   M_HP200 = 200,        /* HP 200 (68010) BSD binary */
  94   M_HP300 = (300 % 256), /* HP 300 (68020+68881) BSD binary */
  95   M_HPUX = (0x20c % 256),/* HP 200/300 HPUX binary */
  96 };
  97
  98 #define N_DYNAMIC(exec) ((exec).a_info & 0x8000000)
  99
 100 #define N_MAGIC(exec) ((exec).a_info & 0xffff)
 101 #define N_MACHTYPE(exec) ((enum machine_type)(((exec).a_info >> 16) & 0xff))
 102 #define N_FLAGS(exec) (((exec).a_info >> 24) & 0xff)
 103 #define N_SET_INFO(exec, magic, type, flags) \
 104 ((exec).a_info = ((magic) & 0xffff) \
 105  | (((int)(type) & 0xff) << 16) \
 106  | (((flags) & 0xff) << 24))
 107
 108 #define N_SET_MAGIC(exec, magic) \
 109 ((exec).a_info = (((exec).a_info & 0xffff0000) | ((magic) & 0xffff)))
 110
 111 #define N_SET_MACHTYPE(exec, machtype) \
 112 ((exec).a_info = \
 113  ((exec).a_info&0xff00ffff) | ((((int)(machtype))&0xff) << 16))
 114
 115 #define N_SET_FLAGS(exec, flags) \
 116 ((exec).a_info = \
 117  ((exec).a_info&0x00ffffff) | (((flags) & 0xff) << 24))
 118
 119 typedef struct aout_symbol {
 120   asymbol symbol;
 121   short desc;
 122   char other;
 123   unsigned char type;
 124 } aout_symbol_type;
 125
 126 /* The `tdata' struct for all a.out-like object file formats.
 127    Various things depend on this struct being around any time an a.out
 128    file is being handled.  An example is dbxread.c in GDB.  */
 129
 130 struct aoutdata {
 131   struct internal_exec *hdr;            /* exec file header */
 132   aout_symbol_type *symbols;            /* symtab for input bfd */
 133
 134   /* For ease, we do this */
 135   asection *textsec;
 136   asection *datasec;
 137   asection *bsssec;
 138
 139   /* We remember these offsets so that after check_file_format, we have
 140      no dependencies on the particular format of the exec_hdr.  */
 141   file_ptr sym_filepos;
 142   file_ptr str_filepos;
 143
 144   /* Size of a relocation entry in external form */
 145   unsigned reloc_entry_size;
 146
 147   /* Size of a symbol table entry in external form */
 148   unsigned symbol_entry_size;
 149
 150   /* Page size - needed for alignment of demand paged files. */
 151   unsigned long page_size;
 152
 153   /* Segment size - needed for alignment of demand paged files. */
 154   unsigned long segment_size;
 155
 156   unsigned exec_bytes_size;
 157 };
 158
 159 #define adata(bfd)              ((struct aoutdata *) ((bfd)->tdata))
 160 #define exec_hdr(bfd)           (adata(bfd)->hdr)
 161 #define obj_aout_symbols(bfd)   (adata(bfd)->symbols)
 162 #define obj_textsec(bfd)        (adata(bfd)->textsec)
 163 #define obj_datasec(bfd)        (adata(bfd)->datasec)
 164 #define obj_bsssec(bfd)         (adata(bfd)->bsssec)
 165 #define obj_sym_filepos(bfd)    (adata(bfd)->sym_filepos)
 166 #define obj_str_filepos(bfd)    (adata(bfd)->str_filepos)
 167 #define obj_reloc_entry_size(bfd) (adata(bfd)->reloc_entry_size)
 168 #define obj_symbol_entry_size(bfd) (adata(bfd)->symbol_entry_size)
 169
 170 /* We take the address of the first element of an asymbol to ensure that the
 171    macro is only ever applied to an asymbol */
 172 #define aout_symbol(asymbol) ((aout_symbol_type *)(&(asymbol)->the_bfd))
 173
 174 /* Prototype declarations for functions defined in aoutx.h  */
 175
 176 PROTO (boolean, NAME(aout,squirt_out_relocs),(bfd *abfd, asection *section));
 177
 178 PROTO (bfd_target *, NAME(aout,some_aout_object_p), (bfd *abfd,
 179                                           struct internal_exec *execp,
 180                                           bfd_target *(*callback)()));
 181 PROTO (boolean, NAME(aout,mkobject), (bfd *abfd));
 182 PROTO (enum machine_type, NAME(aout,machine_type), (enum bfd_architecture arch,
 183                                                 unsigned long machine));
 184 PROTO (boolean, NAME(aout,set_arch_mach), (bfd *abfd, enum bfd_architecture arch,
 185                                                 unsigned long machine));
 186
 187 PROTO (boolean, NAME(aout,new_section_hook), (bfd *abfd, asection *newsect));
 188 PROTO (boolean, NAME(aout,set_section_contents), (bfd *abfd, sec_ptr section,
 189                          PTR location, file_ptr offset, bfd_size_type count));
 190
 191 PROTO (asymbol *,NAME(aout,make_empty_symbol), (bfd *abfd));
 192 PROTO (boolean, NAME(aout,slurp_symbol_table), (bfd *abfd));
 193 PROTO (void,    NAME(aout,write_syms), (bfd *abfd));
 194 PROTO (void,    NAME(aout,reclaim_symbol_table), (bfd *abfd));
 195 PROTO (unsigned int, NAME(aout,get_symtab_upper_bound), (bfd *abfd));
 196 PROTO (unsigned int, NAME(aout,get_symtab), (bfd *abfd, asymbol **location));
 197 PROTO (boolean, NAME(aout,slurp_reloc_table), (bfd *abfd, sec_ptr asect,
 198                                          asymbol **symbols));
 199 PROTO (unsigned int, NAME(aout,canonicalize_reloc), (bfd *abfd, sec_ptr section,
 200                                          arelent **relptr, asymbol **symbols));
 201 PROTO (unsigned int, NAME(aout,get_reloc_upper_bound), (bfd *abfd, sec_ptr asect));
 202 PROTO (void,    NAME(aout,reclaim_reloc), (bfd *ignore_abfd, sec_ptr ignore));
 203 PROTO (alent *, NAME(aout,get_lineno), (bfd *ignore_abfd, asymbol *ignore_symbol));
 204 PROTO (void,    NAME(aout,print_symbol), (bfd *ignore_abfd, PTR file,
 205                             asymbol *symbol, bfd_print_symbol_type how));
 206 PROTO (boolean, NAME(aout,close_and_cleanup), (bfd *abfd));
 207 PROTO (boolean, NAME(aout,find_nearest_line), (bfd *abfd, asection *section,
 208       asymbol **symbols, bfd_vma offset, CONST char **filename_ptr,
 209       CONST char **functionname_ptr, unsigned int *line_ptr));
 210 PROTO (int,     NAME(aout,sizeof_headers), (bfd *ignore_abfd, boolean exec));
 211
 212
 213 PROTO (void,    NAME(aout,swap_exec_header_in), (bfd *abfd,
 214                          struct external_exec *raw_bytes, struct internal_exec *execp));
 215
 216 PROTO (void,    NAME(aout,swap_exec_header_out),(bfd *abfd, struct internal_exec *execp,
 217                          struct external_exec *raw_bytes));
 218
 219 /* A.out uses the generic versions of these routines... */
 220
 221 #define aout_32_get_section_contents    bfd_generic_get_section_contents
 222 #define aout_32_close_and_cleanup       bfd_generic_close_and_cleanup
 223
 224 #define aout_64_get_section_contents    bfd_generic_get_section_contents
 225 #define aout_64_close_and_cleanup       bfd_generic_close_and_cleanup
 226
 227 /* Calculate the file positions of the parts of a newly read aout header */
 228 #define WORK_OUT_FILE_POSITIONS(abfd, execp)                            \
 229   /* The virtual memory addresses of the sections */                    \
 230   obj_datasec (abfd)->vma = N_DATADDR(*execp);                          \
 231   obj_bsssec (abfd)->vma = N_BSSADDR(*execp);                           \
 232   obj_textsec (abfd)->vma = N_TXTADDR(*execp);                          \
 233                                                                         \
 234   /* The file offsets of the sections */                                \
 235   obj_textsec (abfd)->filepos = N_TXTOFF (*execp);                      \
 236   obj_datasec (abfd)->filepos = N_DATOFF (*execp);                      \
 237                                                                         \
 238   /* The file offsets of the relocation info */                         \
 239   obj_textsec (abfd)->rel_filepos = N_TRELOFF(*execp);                  \
 240   obj_datasec (abfd)->rel_filepos = N_DRELOFF(*execp);                  \
 241                                                                         \
 242   /* The file offsets of the string table and symbol table.  */         \
 243   obj_sym_filepos (abfd) = N_SYMOFF (*execp);                           \
 244   obj_str_filepos (abfd) = N_STROFF (*execp);                           \
 245
 246
 247 #define WRITE_HEADERS(abfd, execp)                                            \
 248       {                                                                       \
 249         if (abfd->flags & D_PAGED)                                            \
 250             {                                                                 \
 251               execp->a_text = obj_textsec (abfd)->size;                       \
 252               /* Kludge to distinguish old- and new-style ZMAGIC.             \
 253                  The latter includes the exec header in the text size. */     \
 254               if (obj_textsec(abfd)->filepos == EXEC_BYTES_SIZE)              \
 255                 execp->a_text += EXEC_BYTES_SIZE;                             \
 256               N_SET_MAGIC (*execp, ZMAGIC);                                   \
 257             }                                                                 \
 258         else                                                                  \
 259             {                                                                 \
 260               execp->a_text = obj_textsec (abfd)->size;                       \
 261               if (abfd->flags & WP_TEXT)                                      \
 262                 { N_SET_MAGIC (*execp, NMAGIC); }                             \
 263               else                                                            \
 264                 { N_SET_MAGIC(*execp, OMAGIC); }                              \
 265             }                                                                 \
 266         if (abfd->flags & D_PAGED)                                            \
 267             {                                                                 \
 268               data_pad = ALIGN(obj_datasec(abfd)->size, PAGE_SIZE)            \
 269                   - obj_datasec(abfd)->size;                                  \
 270                                                                               \
 271               if (data_pad > obj_bsssec(abfd)->size)                          \
 272                 execp->a_bss = 0;                                             \
 273               else                                                            \
 274                 execp->a_bss = obj_bsssec(abfd)->size - data_pad;             \
 275               execp->a_data = obj_datasec(abfd)->size + data_pad;             \
 276             }                                                                 \
 277         else                                                                  \
 278             {                                                                 \
 279               execp->a_data = obj_datasec (abfd)->size;                       \
 280               execp->a_bss = obj_bsssec (abfd)->size;                         \
 281             }                                                                 \
 282                                                                               \
 283         execp->a_syms = bfd_get_symcount (abfd) * EXTERNAL_NLIST_SIZE;        \
 284         execp->a_entry = bfd_get_start_address (abfd);                        \
 285                                                                               \
 286         execp->a_trsize = ((obj_textsec (abfd)->reloc_count) *                \
 287                            obj_reloc_entry_size (abfd));                      \
 288         execp->a_drsize = ((obj_datasec (abfd)->reloc_count) *                \
 289                            obj_reloc_entry_size (abfd));                      \
 290         NAME(aout,swap_exec_header_out) (abfd, execp, &exec_bytes);           \
 291                                                                               \
 292         bfd_seek (abfd, 0L, false);                                           \
 293         bfd_write ((PTR) &exec_bytes, 1, EXEC_BYTES_SIZE, abfd);              \
 294         /* Now write out reloc info, followed by syms and strings */          \
 295                                                                               \
 296         if (bfd_get_symcount (abfd) != 0)                                     \
 297             {                                                                 \
 298               bfd_seek (abfd,                                                 \
 299                         (long)(N_SYMOFF(*execp)), false);                     \
 300                                                                               \
 301               NAME(aout,write_syms)(abfd);                                    \
 302                                                                               \
 303               bfd_seek (abfd,   (long)(N_TRELOFF(*execp)), false);            \
 304                                                                               \
 305               if (!NAME(aout,squirt_out_relocs) (abfd, obj_textsec (abfd))) return false; \
 306               bfd_seek (abfd, (long)(N_DRELOFF(*execp)), false);              \
 307                                                                               \
 308               if (!NAME(aout,squirt_out_relocs)(abfd, obj_datasec (abfd))) return false; \
 309             }                                                                 \
 310       }