gas/config/obj-bout.c

   1 /* b.out object file format
   2    Copyright (C) 1989, 90, 91, 92, 93, 94, 95, 1996
   3    Free Software Foundation, Inc.
   4
   5    This file is part of GAS, the GNU Assembler.
   6
   7    GAS is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as
   9    published by the Free Software Foundation; either version 2,
  10    or (at your option) any later version.
  11
  12    GAS is distributed in the hope that it will be useful, but
  13    WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
  15    the GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public
  18    License along with GAS; see the file COPYING.  If not, write
  19    to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
  20
  21 #include "as.h"
  22 #include "obstack.h"
  23 const short                     /* in: segT   out: N_TYPE bits */
  24   seg_N_TYPE[] =
  25 {
  26   N_ABS,
  27   N_TEXT,
  28   N_DATA,
  29   N_BSS,
  30   N_UNDF,                       /* unknown */
  31   N_UNDF,                       /* error */
  32   N_UNDF,                       /* expression */
  33   N_UNDF,                       /* debug */
  34   N_UNDF,                       /* ntv */
  35   N_UNDF,                       /* ptv */
  36   N_REGISTER,                   /* register */
  37 };
  38
  39 const segT N_TYPE_seg[N_TYPE + 2] =
  40 {                               /* N_TYPE == 0x1E = 32-2 */
  41   SEG_UNKNOWN,                  /* N_UNDF == 0 */
  42   SEG_GOOF,
  43   SEG_ABSOLUTE,                 /* N_ABS == 2 */
  44   SEG_GOOF,
  45   SEG_TEXT,                     /* N_TEXT == 4 */
  46   SEG_GOOF,
  47   SEG_DATA,                     /* N_DATA == 6 */
  48   SEG_GOOF,
  49   SEG_BSS,                      /* N_BSS == 8 */
  50   SEG_GOOF,
  51   SEG_GOOF, SEG_GOOF, SEG_GOOF, SEG_GOOF, SEG_GOOF, SEG_GOOF, SEG_GOOF, SEG_GOOF,
  52   SEG_GOOF, SEG_GOOF, SEG_GOOF, SEG_GOOF, SEG_GOOF, SEG_GOOF, SEG_GOOF, SEG_GOOF,
  53   SEG_GOOF, SEG_GOOF, SEG_GOOF, SEG_GOOF,
  54   SEG_REGISTER,                 /* dummy N_REGISTER for regs = 30 */
  55   SEG_GOOF,
  56 };
  57
  58 static void obj_bout_line PARAMS ((int));
  59
  60 const pseudo_typeS obj_pseudo_table[] =
  61 {
  62   {"line", obj_bout_line, 0},   /* source code line number */
  63
  64 /* coff debugging directives.  Currently ignored silently */
  65   {"def", s_ignore, 0},
  66   {"dim", s_ignore, 0},
  67   {"endef", s_ignore, 0},
  68   {"ln", s_ignore, 0},
  69   {"scl", s_ignore, 0},
  70   {"size", s_ignore, 0},
  71   {"tag", s_ignore, 0},
  72   {"type", s_ignore, 0},
  73   {"val", s_ignore, 0},
  74
  75 /* other stuff we don't handle */
  76   {"ABORT", s_ignore, 0},
  77   {"ident", s_ignore, 0},
  78
  79   {NULL}                        /* end sentinel */
  80 };                              /* obj_pseudo_table */
  81
  82 /* Relocation. */
  83
  84 /*
  85  *              emit_relocations()
  86  *
  87  * Crawl along a fixS chain. Emit the segment's relocations.
  88  */
  89 void
  90 obj_emit_relocations (where, fixP, segment_address_in_file)
  91      char **where;
  92      fixS *fixP;                /* Fixup chain for this segment. */
  93      relax_addressT segment_address_in_file;
  94 {
  95   for (; fixP; fixP = fixP->fx_next)
  96     {
  97       if (fixP->fx_done == 0
  98           || fixP->fx_r_type != NO_RELOC)
  99         {
 100           symbolS *sym;
 101
 102           sym = fixP->fx_addsy;
 103           while (sym->sy_value.X_op == O_symbol
 104                  && (! S_IS_DEFINED (sym) || S_IS_COMMON (sym)))
 105             sym = sym->sy_value.X_add_symbol;
 106           fixP->fx_addsy = sym;
 107
 108           tc_bout_fix_to_chars (*where, fixP, segment_address_in_file);
 109           *where += sizeof (struct relocation_info);
 110         }                       /* if there's a symbol */
 111     }                           /* for each fixup */
 112
 113 }                               /* emit_relocations() */
 114
 115 /* Aout file generation & utilities */
 116
 117 /* Convert a lvalue to machine dependent data */
 118 void
 119 obj_header_append (where, headers)
 120      char **where;
 121      object_headers *headers;
 122 {
 123   /* Always leave in host byte order */
 124
 125   headers->header.a_talign = section_alignment[SEG_TEXT];
 126
 127   if (headers->header.a_talign < 2)
 128     {
 129       headers->header.a_talign = 2;
 130     }                           /* force to at least 2 */
 131
 132   headers->header.a_dalign = section_alignment[SEG_DATA];
 133   headers->header.a_balign = section_alignment[SEG_BSS];
 134
 135   headers->header.a_tload = 0;
 136   headers->header.a_dload = md_section_align (SEG_DATA, H_GET_TEXT_SIZE (headers));
 137
 138   headers->header.a_relaxable = linkrelax;
 139
 140 #ifdef CROSS_COMPILE
 141   md_number_to_chars (*where, headers->header.a_magic, sizeof (headers->header.a_magic));
 142   *where += sizeof (headers->header.a_magic);
 143   md_number_to_chars (*where, headers->header.a_text, sizeof (headers->header.a_text));
 144   *where += sizeof (headers->header.a_text);
 145   md_number_to_chars (*where, headers->header.a_data, sizeof (headers->header.a_data));
 146   *where += sizeof (headers->header.a_data);
 147   md_number_to_chars (*where, headers->header.a_bss, sizeof (headers->header.a_bss));
 148   *where += sizeof (headers->header.a_bss);
 149   md_number_to_chars (*where, headers->header.a_syms, sizeof (headers->header.a_syms));
 150   *where += sizeof (headers->header.a_syms);
 151   md_number_to_chars (*where, headers->header.a_entry, sizeof (headers->header.a_entry));
 152   *where += sizeof (headers->header.a_entry);
 153   md_number_to_chars (*where, headers->header.a_trsize, sizeof (headers->header.a_trsize));
 154   *where += sizeof (headers->header.a_trsize);
 155   md_number_to_chars (*where, headers->header.a_drsize, sizeof (headers->header.a_drsize));
 156   *where += sizeof (headers->header.a_drsize);
 157   md_number_to_chars (*where, headers->header.a_tload, sizeof (headers->header.a_tload));
 158   *where += sizeof (headers->header.a_tload);
 159   md_number_to_chars (*where, headers->header.a_dload, sizeof (headers->header.a_dload));
 160   *where += sizeof (headers->header.a_dload);
 161   md_number_to_chars (*where, headers->header.a_talign, sizeof (headers->header.a_talign));
 162   *where += sizeof (headers->header.a_talign);
 163   md_number_to_chars (*where, headers->header.a_dalign, sizeof (headers->header.a_dalign));
 164   *where += sizeof (headers->header.a_dalign);
 165   md_number_to_chars (*where, headers->header.a_balign, sizeof (headers->header.a_balign));
 166   *where += sizeof (headers->header.a_balign);
 167   md_number_to_chars (*where, headers->header.a_relaxable, sizeof (headers->header.a_relaxable));
 168   *where += sizeof (headers->header.a_relaxable);
 169 #else /* ! CROSS_COMPILE */
 170   append (where, (char *) &headers->header, sizeof (headers->header));
 171 #endif /* ! CROSS_COMPILE */
 172 }                               /* a_header_append() */
 173
 174 void
 175 obj_symbol_to_chars (where, symbolP)
 176      char **where;
 177      symbolS *symbolP;
 178 {
 179   md_number_to_chars ((char *) &(S_GET_OFFSET (symbolP)), S_GET_OFFSET (symbolP), sizeof (S_GET_OFFSET (symbolP)));
 180   md_number_to_chars ((char *) &(S_GET_DESC (symbolP)), S_GET_DESC (symbolP), sizeof (S_GET_DESC (symbolP)));
 181   md_number_to_chars ((char *) &symbolP->sy_symbol.n_value, S_GET_VALUE (symbolP), sizeof (symbolP->sy_symbol.n_value));
 182
 183   append (where, (char *) &symbolP->sy_symbol, sizeof (obj_symbol_type));
 184 }                               /* obj_symbol_to_chars() */
 185
 186 void
 187 obj_emit_symbols (where, symbol_rootP)
 188      char **where;
 189      symbolS *symbol_rootP;
 190 {
 191   symbolS *symbolP;
 192
 193   /*
 194          * Emit all symbols left in the symbol chain.
 195          */
 196   for (symbolP = symbol_rootP; symbolP; symbolP = symbol_next (symbolP))
 197     {
 198       /* Used to save the offset of the name. It is used to point
 199                    to the string in memory but must be a file offset. */
 200       char *temp;
 201
 202       temp = S_GET_NAME (symbolP);
 203       S_SET_OFFSET (symbolP, symbolP->sy_name_offset);
 204
 205       /* Any symbol still undefined and is not a dbg symbol is made N_EXT. */
 206       if (!S_IS_DEBUG (symbolP) && !S_IS_DEFINED (symbolP))
 207         S_SET_EXTERNAL (symbolP);
 208
 209       obj_symbol_to_chars (where, symbolP);
 210       S_SET_NAME (symbolP, temp);
 211     }
 212 }                               /* emit_symbols() */
 213
 214 void
 215 obj_symbol_new_hook (symbolP)
 216      symbolS *symbolP;
 217 {
 218   S_SET_OTHER (symbolP, 0);
 219   S_SET_DESC (symbolP, 0);
 220 }
 221
 222 static void
 223 obj_bout_line (ignore)
 224      int ignore;
 225 {
 226   /* Assume delimiter is part of expression. */
 227   /* BSD4.2 as fails with delightful bug, so we */
 228   /* are not being incompatible here. */
 229   new_logical_line ((char *) NULL, (int) (get_absolute_expression ()));
 230   demand_empty_rest_of_line ();
 231 }                               /* obj_bout_line() */
 232
 233 void
 234 obj_read_begin_hook ()
 235 {
 236 }
 237
 238 void
 239 obj_crawl_symbol_chain (headers)
 240      object_headers *headers;
 241 {
 242   symbolS **symbolPP;
 243   symbolS *symbolP;
 244   int symbol_number = 0;
 245
 246   tc_crawl_symbol_chain (headers);
 247
 248   symbolPP = &symbol_rootP;     /*->last symbol chain link. */
 249   while ((symbolP = *symbolPP) != NULL)
 250     {
 251       if (flag_readonly_data_in_text && (S_GET_SEGMENT (symbolP) == SEG_DATA))
 252         {
 253           S_SET_SEGMENT (symbolP, SEG_TEXT);
 254         }                       /* if pusing data into text */
 255
 256       resolve_symbol_value (symbolP, 1);
 257
 258       /* Skip symbols which were equated to undefined or common
 259          symbols.  */
 260       if (symbolP->sy_value.X_op == O_symbol
 261           && (! S_IS_DEFINED (symbolP) || S_IS_COMMON (symbolP)))
 262         {
 263           *symbolPP = symbol_next (symbolP);
 264           continue;
 265         }
 266
 267       /* OK, here is how we decide which symbols go out into the
 268          brave new symtab.  Symbols that do are:
 269
 270          * symbols with no name (stabd's?)
 271          * symbols with debug info in their N_TYPE
 272
 273          Symbols that don't are:
 274          * symbols that are registers
 275          * symbols with \1 as their 3rd character (numeric labels)
 276          * "local labels" as defined by S_LOCAL_NAME(name)
 277          if the -L switch was passed to gas.
 278
 279          All other symbols are output.  We complain if a deleted
 280          symbol was marked external. */
 281
 282
 283       if (1
 284           && !S_IS_REGISTER (symbolP)
 285           && (!S_GET_NAME (symbolP)
 286               || S_IS_DEBUG (symbolP)
 287 #ifdef TC_I960
 288       /* FIXME-SOON this ifdef seems highly dubious to me.  xoxorich. */
 289               || !S_IS_DEFINED (symbolP)
 290               || S_IS_EXTERNAL (symbolP)
 291 #endif /* TC_I960 */
 292               || (S_GET_NAME (symbolP)[0] != '\001' && (flag_keep_locals || !S_LOCAL_NAME (symbolP)))))
 293         {
 294           symbolP->sy_number = symbol_number++;
 295
 296           /* The + 1 after strlen account for the \0 at the
 297                            end of each string */
 298           if (!S_IS_STABD (symbolP))
 299             {
 300               /* Ordinary case. */
 301               symbolP->sy_name_offset = string_byte_count;
 302               string_byte_count += strlen (S_GET_NAME (symbolP)) + 1;
 303             }
 304           else                  /* .Stabd case. */
 305             symbolP->sy_name_offset = 0;
 306           symbolPP = &(symbol_next (symbolP));
 307         }
 308       else
 309         {
 310           if (S_IS_EXTERNAL (symbolP) || !S_IS_DEFINED (symbolP))
 311             {
 312               as_bad (_("Local symbol %s never defined"), S_GET_NAME (symbolP));
 313             }                   /* oops. */
 314
 315           /* Unhook it from the chain */
 316           *symbolPP = symbol_next (symbolP);
 317         }                       /* if this symbol should be in the output */
 318     }                           /* for each symbol */
 319
 320   H_SET_SYMBOL_TABLE_SIZE (headers, symbol_number);
 321 }
 322
 323 /*
 324  * Find strings by crawling along symbol table chain.
 325  */
 326
 327 void
 328 obj_emit_strings (where)
 329      char **where;
 330 {
 331   symbolS *symbolP;
 332
 333 #ifdef CROSS_COMPILE
 334   /* Gotta do md_ byte-ordering stuff for string_byte_count first - KWK */
 335   md_number_to_chars (*where, string_byte_count, sizeof (string_byte_count));
 336   *where += sizeof (string_byte_count);
 337 #else /* CROSS_COMPILE */
 338   append (where, (char *) &string_byte_count, (unsigned long) sizeof (string_byte_count));
 339 #endif /* CROSS_COMPILE */
 340
 341   for (symbolP = symbol_rootP; symbolP; symbolP = symbol_next (symbolP))
 342     {
 343       if (S_GET_NAME (symbolP))
 344         append (where, S_GET_NAME (symbolP), (unsigned long) (strlen (S_GET_NAME (symbolP)) + 1));
 345     }                           /* walk symbol chain */
 346 }
 347
 348 /* end of obj-bout.c */