gas/config/obj-bout.c

   1 /* b.out object file format
   2    Copyright (C) 1989, 1990, 1991, 1992 Free Software Foundation, Inc.
   3
   4    This file is part of GAS, the GNU Assembler.
   5
   6    GAS is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as
   8    published by the Free Software Foundation; either version 2,
   9    or (at your option) any later version.
  10
  11    GAS is distributed in the hope that it will be useful, but
  12    WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
  14    the GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public
  17    License along with GAS; see the file COPYING.  If not, write
  18    to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
  19
  20 #include "as.h"
  21 #include "obstack.h"
  22 const short                     /* in: segT   out: N_TYPE bits */
  23   seg_N_TYPE[] =
  24 {
  25   N_ABS,
  26   N_TEXT,
  27   N_DATA,
  28   N_BSS,
  29   N_UNDF,                       /* unknown */
  30   N_UNDF,                       /* error */
  31   N_UNDF,                       /* expression */
  32   N_UNDF,                       /* debug */
  33   N_UNDF,                       /* ntv */
  34   N_UNDF,                       /* ptv */
  35   N_REGISTER,                   /* register */
  36 };
  37
  38 const segT N_TYPE_seg[N_TYPE + 2] =
  39 {                               /* N_TYPE == 0x1E = 32-2 */
  40   SEG_UNKNOWN,                  /* N_UNDF == 0 */
  41   SEG_GOOF,
  42   SEG_ABSOLUTE,                 /* N_ABS == 2 */
  43   SEG_GOOF,
  44   SEG_TEXT,                     /* N_TEXT == 4 */
  45   SEG_GOOF,
  46   SEG_DATA,                     /* N_DATA == 6 */
  47   SEG_GOOF,
  48   SEG_BSS,                      /* N_BSS == 8 */
  49   SEG_GOOF,
  50   SEG_GOOF, SEG_GOOF, SEG_GOOF, SEG_GOOF, SEG_GOOF, SEG_GOOF, SEG_GOOF, 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,
  53   SEG_REGISTER,                 /* dummy N_REGISTER for regs = 30 */
  54   SEG_GOOF,
  55 };
  56
  57 static void obj_bout_line PARAMS ((int));
  58
  59 const pseudo_typeS obj_pseudo_table[] =
  60 {
  61   {"line", obj_bout_line, 0},   /* source code line number */
  62
  63 /* coff debugging directives.  Currently ignored silently */
  64   {"def", s_ignore, 0},
  65   {"dim", s_ignore, 0},
  66   {"endef", s_ignore, 0},
  67   {"ln", s_ignore, 0},
  68   {"scl", s_ignore, 0},
  69   {"size", s_ignore, 0},
  70   {"tag", s_ignore, 0},
  71   {"type", s_ignore, 0},
  72   {"val", s_ignore, 0},
  73
  74 /* other stuff we don't handle */
  75   {"ABORT", s_ignore, 0},
  76   {"ident", s_ignore, 0},
  77
  78   {NULL}                        /* end sentinel */
  79 };                              /* obj_pseudo_table */
  80
  81 /* Relocation. */
  82
  83 /*
  84  *              emit_relocations()
  85  *
  86  * Crawl along a fixS chain. Emit the segment's relocations.
  87  */
  88 void
  89 obj_emit_relocations (where, fixP, segment_address_in_file)
  90      char **where;
  91      fixS *fixP;                /* Fixup chain for this segment. */
  92      relax_addressT segment_address_in_file;
  93 {
  94   for (; fixP; fixP = fixP->fx_next)
  95     {
  96       if (fixP->fx_done == 0
  97           || fixP->fx_r_type != NO_RELOC)
  98         {
  99           symbolS *sym;
 100
 101           sym = fixP->fx_addsy;
 102           while (sym->sy_value.X_op == O_symbol
 103                  && (! S_IS_DEFINED (sym) || S_IS_COMMON (sym)))
 104             sym = sym->sy_value.X_add_symbol;
 105           fixP->fx_addsy = sym;
 106
 107           tc_bout_fix_to_chars (*where, fixP, segment_address_in_file);
 108           *where += sizeof (struct relocation_info);
 109         }                       /* if there's a symbol */
 110     }                           /* for each fixup */
 111
 112 }                               /* emit_relocations() */
 113
 114 /* Aout file generation & utilities */
 115
 116 /* Convert a lvalue to machine dependent data */
 117 void
 118 obj_header_append (where, headers)
 119      char **where;
 120      object_headers *headers;
 121 {
 122   /* Always leave in host byte order */
 123
 124   headers->header.a_talign = section_alignment[SEG_TEXT];
 125
 126   if (headers->header.a_talign < 2)
 127     {
 128       headers->header.a_talign = 2;
 129     }                           /* force to at least 2 */
 130
 131   headers->header.a_dalign = section_alignment[SEG_DATA];
 132   headers->header.a_balign = section_alignment[SEG_BSS];
 133
 134   headers->header.a_tload = 0;
 135   headers->header.a_dload = md_section_align (SEG_DATA, H_GET_TEXT_SIZE (headers));
 136
 137   headers->header.a_relaxable = linkrelax;
 138
 139 #ifdef CROSS_COMPILE
 140   md_number_to_chars (*where, headers->header.a_magic, sizeof (headers->header.a_magic));
 141   *where += sizeof (headers->header.a_magic);
 142   md_number_to_chars (*where, headers->header.a_text, sizeof (headers->header.a_text));
 143   *where += sizeof (headers->header.a_text);
 144   md_number_to_chars (*where, headers->header.a_data, sizeof (headers->header.a_data));
 145   *where += sizeof (headers->header.a_data);
 146   md_number_to_chars (*where, headers->header.a_bss, sizeof (headers->header.a_bss));
 147   *where += sizeof (headers->header.a_bss);
 148   md_number_to_chars (*where, headers->header.a_syms, sizeof (headers->header.a_syms));
 149   *where += sizeof (headers->header.a_syms);
 150   md_number_to_chars (*where, headers->header.a_entry, sizeof (headers->header.a_entry));
 151   *where += sizeof (headers->header.a_entry);
 152   md_number_to_chars (*where, headers->header.a_trsize, sizeof (headers->header.a_trsize));
 153   *where += sizeof (headers->header.a_trsize);
 154   md_number_to_chars (*where, headers->header.a_drsize, sizeof (headers->header.a_drsize));
 155   *where += sizeof (headers->header.a_drsize);
 156   md_number_to_chars (*where, headers->header.a_tload, sizeof (headers->header.a_tload));
 157   *where += sizeof (headers->header.a_tload);
 158   md_number_to_chars (*where, headers->header.a_dload, sizeof (headers->header.a_dload));
 159   *where += sizeof (headers->header.a_dload);
 160   md_number_to_chars (*where, headers->header.a_talign, sizeof (headers->header.a_talign));
 161   *where += sizeof (headers->header.a_talign);
 162   md_number_to_chars (*where, headers->header.a_dalign, sizeof (headers->header.a_dalign));
 163   *where += sizeof (headers->header.a_dalign);
 164   md_number_to_chars (*where, headers->header.a_balign, sizeof (headers->header.a_balign));
 165   *where += sizeof (headers->header.a_balign);
 166   md_number_to_chars (*where, headers->header.a_relaxable, sizeof (headers->header.a_relaxable));
 167   *where += sizeof (headers->header.a_relaxable);
 168 #else /* ! CROSS_COMPILE */
 169   append (where, (char *) &headers->header, sizeof (headers->header));
 170 #endif /* ! CROSS_COMPILE */
 171 }                               /* a_header_append() */
 172
 173 void
 174 obj_symbol_to_chars (where, symbolP)
 175      char **where;
 176      symbolS *symbolP;
 177 {
 178   md_number_to_chars ((char *) &(S_GET_OFFSET (symbolP)), S_GET_OFFSET (symbolP), sizeof (S_GET_OFFSET (symbolP)));
 179   md_number_to_chars ((char *) &(S_GET_DESC (symbolP)), S_GET_DESC (symbolP), sizeof (S_GET_DESC (symbolP)));
 180   md_number_to_chars ((char *) &symbolP->sy_symbol.n_value, S_GET_VALUE (symbolP), sizeof (symbolP->sy_symbol.n_value));
 181
 182   append (where, (char *) &symbolP->sy_symbol, sizeof (obj_symbol_type));
 183 }                               /* obj_symbol_to_chars() */
 184
 185 void
 186 obj_emit_symbols (where, symbol_rootP)
 187      char **where;
 188      symbolS *symbol_rootP;
 189 {
 190   symbolS *symbolP;
 191
 192   /*
 193          * Emit all symbols left in the symbol chain.
 194          */
 195   for (symbolP = symbol_rootP; symbolP; symbolP = symbol_next (symbolP))
 196     {
 197       /* Used to save the offset of the name. It is used to point
 198                    to the string in memory but must be a file offset. */
 199       char *temp;
 200
 201       temp = S_GET_NAME (symbolP);
 202       S_SET_OFFSET (symbolP, symbolP->sy_name_offset);
 203
 204       /* Any symbol still undefined and is not a dbg symbol is made N_EXT. */
 205       if (!S_IS_DEBUG (symbolP) && !S_IS_DEFINED (symbolP))
 206         S_SET_EXTERNAL (symbolP);
 207
 208       obj_symbol_to_chars (where, symbolP);
 209       S_SET_NAME (symbolP, temp);
 210     }
 211 }                               /* emit_symbols() */
 212
 213 void
 214 obj_symbol_new_hook (symbolP)
 215      symbolS *symbolP;
 216 {
 217   S_SET_OTHER (symbolP, 0);
 218   S_SET_DESC (symbolP, 0);
 219 }
 220
 221 static void
 222 obj_bout_line (ignore)
 223      int ignore;
 224 {
 225   /* Assume delimiter is part of expression. */
 226   /* BSD4.2 as fails with delightful bug, so we */
 227   /* are not being incompatible here. */
 228   new_logical_line ((char *) NULL, (int) (get_absolute_expression ()));
 229   demand_empty_rest_of_line ();
 230 }                               /* obj_bout_line() */
 231
 232 void
 233 obj_read_begin_hook ()
 234 {
 235 }
 236
 237 void
 238 obj_crawl_symbol_chain (headers)
 239      object_headers *headers;
 240 {
 241   symbolS **symbolPP;
 242   symbolS *symbolP;
 243   int symbol_number = 0;
 244
 245   tc_crawl_symbol_chain (headers);
 246
 247   symbolPP = &symbol_rootP;     /*->last symbol chain link. */
 248   while ((symbolP = *symbolPP) != NULL)
 249     {
 250       if (flag_readonly_data_in_text && (S_GET_SEGMENT (symbolP) == SEG_DATA))
 251         {
 252           S_SET_SEGMENT (symbolP, SEG_TEXT);
 253         }                       /* if pusing data into text */
 254
 255       resolve_symbol_value (symbolP);
 256
 257       /* Skip symbols which were equated to undefined or common
 258          symbols.  */
 259       if (symbolP->sy_value.X_op == O_symbol
 260           && (! S_IS_DEFINED (symbolP) || S_IS_COMMON (symbolP)))
 261         {
 262           *symbolPP = symbol_next (symbolP);
 263           continue;
 264         }
 265
 266       /* OK, here is how we decide which symbols go out into the
 267          brave new symtab.  Symbols that do are:
 268
 269          * symbols with no name (stabd's?)
 270          * symbols with debug info in their N_TYPE
 271
 272          Symbols that don't are:
 273          * symbols that are registers
 274          * symbols with \1 as their 3rd character (numeric labels)
 275          * "local labels" as defined by S_LOCAL_NAME(name)
 276          if the -L switch was passed to gas.
 277
 278          All other symbols are output.  We complain if a deleted
 279          symbol was marked external. */
 280
 281
 282       if (1
 283           && !S_IS_REGISTER (symbolP)
 284           && (!S_GET_NAME (symbolP)
 285               || S_IS_DEBUG (symbolP)
 286 #ifdef TC_I960
 287       /* FIXME-SOON this ifdef seems highly dubious to me.  xoxorich. */
 288               || !S_IS_DEFINED (symbolP)
 289               || S_IS_EXTERNAL (symbolP)
 290 #endif /* TC_I960 */
 291               || (S_GET_NAME (symbolP)[0] != '\001' && (flag_keep_locals || !S_LOCAL_NAME (symbolP)))))
 292         {
 293           symbolP->sy_number = symbol_number++;
 294
 295           /* The + 1 after strlen account for the \0 at the
 296                            end of each string */
 297           if (!S_IS_STABD (symbolP))
 298             {
 299               /* Ordinary case. */
 300               symbolP->sy_name_offset = string_byte_count;
 301               string_byte_count += strlen (S_GET_NAME (symbolP)) + 1;
 302             }
 303           else                  /* .Stabd case. */
 304             symbolP->sy_name_offset = 0;
 305           symbolPP = &(symbol_next (symbolP));
 306         }
 307       else
 308         {
 309           if (S_IS_EXTERNAL (symbolP) || !S_IS_DEFINED (symbolP))
 310             {
 311               as_bad ("Local symbol %s never defined", S_GET_NAME (symbolP));
 312             }                   /* oops. */
 313
 314           /* Unhook it from the chain */
 315           *symbolPP = symbol_next (symbolP);
 316         }                       /* if this symbol should be in the output */
 317     }                           /* for each symbol */
 318
 319   H_SET_SYMBOL_TABLE_SIZE (headers, symbol_number);
 320 }
 321
 322 /*
 323  * Find strings by crawling along symbol table chain.
 324  */
 325
 326 void
 327 obj_emit_strings (where)
 328      char **where;
 329 {
 330   symbolS *symbolP;
 331
 332 #ifdef CROSS_COMPILE
 333   /* Gotta do md_ byte-ordering stuff for string_byte_count first - KWK */
 334   md_number_to_chars (*where, string_byte_count, sizeof (string_byte_count));
 335   *where += sizeof (string_byte_count);
 336 #else /* CROSS_COMPILE */
 337   append (where, (char *) &string_byte_count, (unsigned long) sizeof (string_byte_count));
 338 #endif /* CROSS_COMPILE */
 339
 340   for (symbolP = symbol_rootP; symbolP; symbolP = symbol_next (symbolP))
 341     {
 342       if (S_GET_NAME (symbolP))
 343         append (where, S_GET_NAME (symbolP), (unsigned long) (strlen (S_GET_NAME (symbolP)) + 1));
 344     }                           /* walk symbol chain */
 345 }
 346
 347 /* end of obj-bout.c */