gas/config/obj-aout.c

   1 /* a.out object file format
   2    Copyright (C) 1989, 1990, 1991 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 1,
   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, 675 Mass Ave, Cambridge, MA 02139, USA. */
  19
  20 /* $Id$ */
  21
  22 #include "as.h"
  23
  24 #include "obstack.h"
  25
  26  /* in: segT   out: N_TYPE bits */
  27 const short seg_N_TYPE[] = {
  28   N_ABS,
  29   N_TEXT,
  30   N_DATA,
  31   N_BSS,
  32   N_UNDF, /* unknown */
  33   N_UNDF, /* absent */
  34   N_UNDF, /* pass1 */
  35   N_UNDF, /* error */
  36   N_UNDF, /* bignum/flonum */
  37   N_UNDF, /* difference */
  38   N_UNDF, /* debug */
  39   N_UNDF, /* ntv */
  40   N_UNDF, /* ptv */
  41   N_REGISTER, /* register */
  42 };
  43
  44 const segT N_TYPE_seg [N_TYPE+2] = {    /* N_TYPE == 0x1E = 32-2 */
  45         SEG_UNKNOWN,                    /* N_UNDF == 0 */
  46         SEG_GOOF,
  47         SEG_ABSOLUTE,                   /* N_ABS == 2 */
  48         SEG_GOOF,
  49         SEG_TEXT,                       /* N_TEXT == 4 */
  50         SEG_GOOF,
  51         SEG_DATA,                       /* N_DATA == 6 */
  52         SEG_GOOF,
  53         SEG_BSS,                        /* N_BSS == 8 */
  54         SEG_GOOF,
  55         SEG_GOOF, SEG_GOOF, SEG_GOOF, SEG_GOOF, SEG_GOOF, SEG_GOOF, SEG_GOOF, SEG_GOOF,
  56         SEG_GOOF, SEG_GOOF, SEG_GOOF, SEG_GOOF, SEG_GOOF, SEG_GOOF, SEG_GOOF, SEG_GOOF,
  57         SEG_GOOF, SEG_GOOF, SEG_GOOF, SEG_GOOF,
  58         SEG_REGISTER,                   /* dummy N_REGISTER for regs = 30 */
  59         SEG_GOOF,
  60 };
  61
  62 #ifdef __STDC__
  63 static void obj_aout_stab(int what);
  64 static void obj_aout_line(void);
  65 static void obj_aout_desc(void);
  66 #else /* __STDC__ */
  67 static void obj_aout_desc();
  68 static void obj_aout_stab();
  69 static void obj_aout_line();
  70 #endif /* __STDC__ */
  71
  72 const pseudo_typeS obj_pseudo_table[] = {
  73         { "line",       obj_aout_line,          0       }, /* source code line number */
  74         { "ln",         obj_aout_line,          0       }, /* source code line number */
  75         { "desc",       obj_aout_desc,          0       }, /* def */
  76         { "stabd",      obj_aout_stab,          'd'     }, /* stabs */
  77         { "stabn",      obj_aout_stab,          'n'     }, /* stabs */
  78         { "stabs",      obj_aout_stab,          's'     }, /* stabs */
  79
  80         { NULL} /* end sentinel */
  81 }; /* obj_pseudo_table */
  82
  83
  84 /* Relocation. */
  85
  86 /*
  87  * In: length of relocation (or of address) in chars: 1, 2 or 4.
  88  * Out: GNU LD relocation length code: 0, 1, or 2.
  89  */
  90
  91 static unsigned char
  92 nbytes_r_length [] = {
  93   42, 0, 1, 42, 2
  94   };
  95
  96 /*
  97  *              emit_relocations()
  98  *
  99  * Crawl along a fixS chain. Emit the segment's relocations.
 100  */
 101 void obj_emit_relocations(where, fixP, segment_address_in_file)
 102 char **where;
 103 fixS *fixP; /* Fixup chain for this segment. */
 104 relax_addressT segment_address_in_file;
 105 {
 106         struct reloc_info_generic ri;
 107         register symbolS *symbolP;
 108
 109         /* If a machine dependent emitter is needed, call it instead. */
 110         if (md_emit_relocations) {
 111                 (*md_emit_relocations) (fixP, segment_address_in_file);
 112                 return;
 113         }
 114
 115         /* JF this is for paranoia */
 116         bzero((char *)&ri,sizeof(ri));
 117         for (;  fixP;  fixP = fixP->fx_next) {
 118                 if ((symbolP = fixP->fx_addsy) != 0) {
 119                         ri.r_bsr                = fixP->fx_bsr;
 120                         ri.r_disp               = fixP->fx_im_disp;
 121                         ri.r_callj              = fixP->fx_callj;
 122                         ri.r_length             = nbytes_r_length [fixP->fx_size];
 123                         ri.r_pcrel              = fixP->fx_pcrel;
 124                         ri.r_address    = fixP->fx_frag->fr_address + fixP->fx_where - segment_address_in_file;
 125
 126                         if (S_GET_TYPE(symbolP) == N_UNDF) {
 127                                 ri.r_extern     = 1;
 128                                 ri.r_symbolnum  = symbolP->sy_number;
 129                         } else {
 130                                 ri.r_extern     = 0;
 131                                 ri.r_symbolnum  = S_GET_TYPE(symbolP);
 132                         }
 133
 134                         /* Output the relocation information in machine-dependent form. */
 135                         md_ri_to_chars(*where, &ri);
 136                         *where += md_reloc_size;
 137                 } /* if there is an add symbol */
 138         } /* for each fix */
 139
 140         return;
 141 } /* emit_relocations() */
 142
 143 /* Aout file generation & utilities */
 144 void obj_header_append(where, headers)
 145 char **where;
 146 object_headers *headers;
 147 {
 148         tc_headers_hook(headers);
 149
 150 #ifdef CROSS_ASSEMBLE
 151         md_number_to_chars(*where, headers->header.a_info, sizeof(headers->header.a_info));
 152         *where += sizeof(headers->header.a_info);
 153         md_number_to_chars(*where, headers->header.a_text, sizeof(headers->header.a_text));
 154         *where += sizeof(headers->header.a_text);
 155         md_number_to_chars(*where, headers->header.a_data, sizeof(headers->header.a_data));
 156         *where += sizeof(headers->header.a_data);
 157         md_number_to_chars(*where, headers->header.a_bss, sizeof(headers->header.a_bss));
 158         *where += sizeof(headers->header.a_bss);
 159         md_number_to_chars(*where, headers->header.a_syms, sizeof(headers->header.a_syms));
 160         *where += sizeof(headers->header.a_syms);
 161         md_number_to_chars(*where, headers->header.a_entry, sizeof(headers->header.a_entry));
 162         *where += sizeof(headers->header.a_entry);
 163         md_number_to_chars(*where, headers->header.a_trsize, sizeof(headers->header.a_trsize));
 164         *where += sizeof(headers->header.a_trsize);
 165         md_number_to_chars(*where, headers->header.a_drsize, sizeof(headers->header.a_drsize));
 166         *where += sizeof(headers->header.a_drsize);
 167 #ifdef EXEC_MACHINE_TYPE
 168         md_number_to_chars(*where, headers->header.a_machtype, sizeof(headers->header.a_machtype));
 169         *where += sizeof(headers->header.a_machtype);
 170 #endif /* EXEC_MACHINE_TYPE */
 171 #ifdef EXEC_VERSION
 172         md_number_to_chars(*where, headers->header.a_version, sizeof(headers->header.a_version));
 173         *where += sizeof(headers->header.a_version);
 174 #endif /* EXEC_VERSION */
 175
 176 #else /* CROSS_ASSEMBLE */
 177
 178         append(where, (char *) &headers->header, sizeof(headers->header));
 179 #endif /* CROSS_ASSEMBLE */
 180
 181         return;
 182 } /* obj_append_header() */
 183
 184 void obj_symbol_to_chars(where, symbolP)
 185 char **where;
 186 symbolS *symbolP;
 187 {
 188         md_number_to_chars((char *)&(S_GET_OFFSET(symbolP)), S_GET_OFFSET(symbolP), sizeof(S_GET_OFFSET(symbolP)));
 189         md_number_to_chars((char *)&(S_GET_DESC(symbolP)), S_GET_DESC(symbolP), sizeof(S_GET_DESC(symbolP)));
 190         md_number_to_chars((char *)&(S_GET_VALUE(symbolP)), S_GET_VALUE(symbolP), sizeof(S_GET_VALUE(symbolP)));
 191
 192         append(where, (char *)&symbolP->sy_symbol, sizeof(obj_symbol_type));
 193 } /* obj_symbol_to_chars() */
 194
 195 void obj_emit_symbols(where, symbol_rootP)
 196 char **where;
 197 symbolS *symbol_rootP;
 198 {
 199     symbolS *   symbolP;
 200
 201     /*
 202      * Emit all symbols left in the symbol chain.
 203  */
 204     for(symbolP = symbol_rootP; symbolP; symbolP = symbol_next(symbolP)) {
 205         /* Used to save the offset of the name. It is used to point
 206            to the string in memory but must be a file offset. */
 207         register char *temp;
 208
 209         temp = S_GET_NAME(symbolP);
 210         S_SET_OFFSET(symbolP, symbolP->sy_name_offset);
 211
 212         /* Any symbol still undefined and is not a dbg symbol is made N_EXT. */
 213         if (!S_IS_DEBUG(symbolP) && !S_IS_DEFINED(symbolP)) S_SET_EXTERNAL(symbolP);
 214
 215         obj_symbol_to_chars(where, symbolP);
 216         S_SET_NAME(symbolP,temp);
 217     }
 218 } /* emit_symbols() */
 219
 220 void obj_symbol_new_hook(symbolP)
 221 symbolS *symbolP;
 222 {
 223         S_SET_OTHER(symbolP, 0);
 224         S_SET_DESC(symbolP, 0);
 225         return;
 226 } /* obj_symbol_new_hook() */
 227
 228 static void obj_aout_line() {
 229         /* Assume delimiter is part of expression. */
 230         /* BSD4.2 as fails with delightful bug, so we */
 231         /* are not being incompatible here. */
 232         new_logical_line((char *)NULL, (int)(get_absolute_expression()));
 233         demand_empty_rest_of_line();
 234 } /* obj_aout_line() */
 235
 236 /*
 237  *                      stab()
 238  *
 239  * Handle .stabX directives, which used to be open-coded.
 240  * So much creeping featurism overloaded the semantics that we decided
 241  * to put all .stabX thinking in one place. Here.
 242  *
 243  * We try to make any .stabX directive legal. Other people's AS will often
 244  * do assembly-time consistency checks: eg assigning meaning to n_type bits
 245  * and "protecting" you from setting them to certain values. (They also zero
 246  * certain bits before emitting symbols. Tut tut.)
 247  *
 248  * If an expression is not absolute we either gripe or use the relocation
 249  * information. Other people's assemblers silently forget information they
 250  * don't need and invent information they need that you didn't supply.
 251  *
 252  * .stabX directives always make a symbol table entry. It may be junk if
 253  * the rest of your .stabX directive is malformed.
 254  */
 255 static void obj_aout_stab(what)
 256 int what;
 257 {
 258   register symbolS *    symbolP = 0;
 259   register char *       string;
 260            int saved_type = 0;
 261            int length;
 262            int goof;    /* TRUE if we have aborted. */
 263            long longint;
 264
 265 /*
 266  * Enter with input_line_pointer pointing past .stabX and any following
 267  * whitespace.
 268  */
 269         goof = 0; /* JF who forgot this?? */
 270         if (what == 's') {
 271                 string = demand_copy_C_string(& length);
 272                 SKIP_WHITESPACE();
 273                 if (* input_line_pointer == ',')
 274                         input_line_pointer ++;
 275                 else {
 276                         as_bad("I need a comma after symbol's name");
 277                         goof = 1;
 278                 }
 279         } else
 280                 string = "";
 281
 282 /*
 283  * Input_line_pointer->after ','.  String->symbol name.
 284  */
 285         if (! goof) {
 286                 symbolP = symbol_new(string,
 287                                      SEG_UNKNOWN,
 288                                      0,
 289                                      (struct frag *)0);
 290                 switch (what) {
 291                 case 'd':
 292                         S_SET_NAME(symbolP, NULL); /* .stabd feature. */
 293                         S_SET_VALUE(symbolP, obstack_next_free(&frags) - frag_now->fr_literal);
 294                         symbolP->sy_frag = frag_now;
 295                         break;
 296
 297                 case 'n':
 298                         symbolP->sy_frag = &zero_address_frag;
 299                         break;
 300
 301                 case 's':
 302                         symbolP->sy_frag = & zero_address_frag;
 303                         break;
 304
 305                 default:
 306                         BAD_CASE(what);
 307                         break;
 308                 }
 309
 310                 if (get_absolute_expression_and_terminator(&longint) == ',')
 311                         symbolP->sy_symbol.n_type = saved_type = longint;
 312                 else {
 313                         as_bad("I want a comma after the n_type expression");
 314                         goof = 1;
 315                         input_line_pointer --; /* Backup over a non-',' char. */
 316                 }
 317         }
 318
 319         if (!goof) {
 320                 if (get_absolute_expression_and_terminator(&longint) == ',')
 321                         S_SET_OTHER(symbolP, longint);
 322                 else {
 323                         as_bad("I want a comma after the n_other expression");
 324                         goof = 1;
 325                         input_line_pointer--; /* Backup over a non-',' char. */
 326                 }
 327         }
 328
 329         if (!goof) {
 330                 S_SET_DESC(symbolP, get_absolute_expression());
 331                 if (what == 's' || what == 'n') {
 332                         if (*input_line_pointer != ',') {
 333                                 as_bad("I want a comma after the n_desc expression");
 334                                 goof = 1;
 335                         } else {
 336                                 input_line_pointer++;
 337                         }
 338                 }
 339         }
 340
 341         if ((!goof) && (what=='s' || what=='n')) {
 342                 pseudo_set(symbolP);
 343                 symbolP->sy_symbol.n_type = saved_type;
 344         }
 345
 346         if (goof)
 347                 ignore_rest_of_line();
 348         else
 349                 demand_empty_rest_of_line ();
 350 } /* obj_aout_stab() */
 351
 352 static void obj_aout_desc() {
 353         register char *name;
 354         register char c;
 355         register char *p;
 356         register symbolS *symbolP;
 357         register int temp;
 358
 359         /*
 360          * Frob invented at RMS' request. Set the n_desc of a symbol.
 361  */
 362         name = input_line_pointer;
 363         c = get_symbol_end();
 364         p = input_line_pointer;
 365         * p = c;
 366         SKIP_WHITESPACE();
 367         if (*input_line_pointer != ',') {
 368                 *p = 0;
 369                 as_bad("Expected comma after name \"%s\"", name);
 370                 *p = c;
 371                 ignore_rest_of_line();
 372         } else {
 373                 input_line_pointer ++;
 374                 temp = get_absolute_expression();
 375                 *p = 0;
 376                 symbolP = symbol_find_or_make(name);
 377                 *p = c;
 378                 S_SET_DESC(symbolP,temp);
 379         }
 380         demand_empty_rest_of_line();
 381 } /* obj_aout_desc() */
 382
 383 void obj_read_begin_hook() {
 384         return;
 385 } /* obj_read_begin_hook() */
 386
 387 void obj_crawl_symbol_chain(headers)
 388 object_headers *headers;
 389 {
 390         symbolS *symbolP;
 391         symbolS **symbolPP;
 392         int symbol_number = 0;
 393
 394         /* JF deal with forward references first... */
 395         for (symbolP = symbol_rootP; symbolP; symbolP = symbol_next(symbolP)) {
 396                 if (symbolP->sy_forward) {
 397                         S_SET_VALUE(symbolP, S_GET_VALUE(symbolP)
 398                                     + S_GET_VALUE(symbolP->sy_forward)
 399                                     + symbolP->sy_forward->sy_frag->fr_address);
 400
 401                         symbolP->sy_forward=0;
 402                 } /* if it has a forward reference */
 403         } /* walk the symbol chain */
 404
 405         tc_crawl_symbol_chain(headers);
 406
 407         symbolPP = &symbol_rootP;       /*->last symbol chain link. */
 408         while ((symbolP  = *symbolPP) != NULL) {
 409                 if (flagseen['R'] && (S_GET_SEGMENT(symbolP) == SEG_DATA)) {
 410                         S_SET_SEGMENT(symbolP, SEG_TEXT);
 411                 } /* if pusing data into text */
 412
 413                 S_SET_VALUE(symbolP, S_GET_VALUE(symbolP) + symbolP->sy_frag->fr_address);
 414
 415                 /* OK, here is how we decide which symbols go out into the
 416                    brave new symtab.  Symbols that do are:
 417
 418                    * symbols with no name (stabd's?)
 419                    * symbols with debug info in their N_TYPE
 420
 421                    Symbols that don't are:
 422                    * symbols that are registers
 423                    * symbols with \1 as their 3rd character (numeric labels)
 424                    * "local labels" as defined by S_LOCAL_NAME(name)
 425                    if the -L switch was passed to gas.
 426
 427                    All other symbols are output.  We complain if a deleted
 428                    symbol was marked external. */
 429
 430
 431                 if (!S_IS_REGISTER(symbolP)
 432                     && (!S_GET_NAME(symbolP)
 433                         || S_IS_DEBUG(symbolP)
 434 #ifdef TC_I960
 435                         /* FIXME-SOON this ifdef seems highly dubious to me.  xoxorich. */
 436                         || !S_IS_DEFINED(symbolP)
 437                         || S_IS_EXTERNAL(symbolP)
 438 #endif /* TC_I960 */
 439                         || (S_GET_NAME(symbolP)[0] != '\001' && (flagseen ['L'] || ! S_LOCAL_NAME(symbolP))))) {
 440                         symbolP->sy_number = symbol_number++;
 441
 442                         /* The + 1 after strlen account for the \0 at the
 443                            end of each string */
 444                         if (!S_IS_STABD(symbolP)) {
 445                                 /* Ordinary case. */
 446                                 symbolP->sy_name_offset = string_byte_count;
 447                                 string_byte_count += strlen(S_GET_NAME(symbolP)) + 1;
 448                         }
 449                         else    /* .Stabd case. */
 450                             symbolP->sy_name_offset = 0;
 451                         symbolPP = &(symbol_next(symbolP));
 452                 } else {
 453                         if (S_IS_EXTERNAL(symbolP) || !S_IS_DEFINED(symbolP)) {
 454                                 as_bad("Local symbol %s never defined", S_GET_NAME(symbolP));
 455                         } /* oops. */
 456
 457                         /* Unhook it from the chain */
 458                         *symbolPP = symbol_next(symbolP);
 459                 } /* if this symbol should be in the output */
 460         } /* for each symbol */
 461
 462         H_SET_SYMBOL_TABLE_SIZE(headers, symbol_number);
 463
 464         return;
 465 } /* obj_crawl_symbol_chain() */
 466
 467 /*
 468  * Find strings by crawling along symbol table chain.
 469  */
 470
 471 void obj_emit_strings(where)
 472 char **where;
 473 {
 474         symbolS *symbolP;
 475
 476 #ifdef CROSS_ASSEMBLE
 477         /* Gotta do md_ byte-ordering stuff for string_byte_count first - KWK */
 478         md_number_to_chars(*where, string_byte_count, sizeof(string_byte_count));
 479         *where += sizeof(string_byte_count);
 480 #else /* CROSS_ASSEMBLE */
 481         append (where, (char *)&string_byte_count, (unsigned long)sizeof(string_byte_count));
 482 #endif /* CROSS_ASSEMBLE */
 483
 484         for(symbolP = symbol_rootP; symbolP; symbolP = symbol_next(symbolP)) {
 485                 if(S_GET_NAME(symbolP))
 486                     append(&next_object_file_charP, S_GET_NAME(symbolP),
 487                            (unsigned long)(strlen (S_GET_NAME(symbolP)) + 1));
 488         } /* walk symbol chain */
 489
 490         return;
 491 } /* obj_emit_strings() */
 492
 493 /*
 494  * Local Variables:
 495  * comment-column: 0
 496  * fill-column: 131
 497  * End:
 498  */
 499
 500 /* end of obj-aout.c */