gas/config/obj-aout.c

   1 /* a.out object file format
   2    Copyright (C) 1989, 1990, 1991, 1992, 1993, 1994, 1995 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, 675 Mass Ave, Cambridge, MA 02139, USA. */
  19
  20 #include "as.h"
  21 #ifdef BFD_ASSEMBLER
  22 #undef NO_RELOC
  23 #include "aout/aout64.h"
  24 #endif
  25 #include "obstack.h"
  26
  27 #ifndef BFD_ASSEMBLER
  28 /* in: segT   out: N_TYPE bits */
  29 const short seg_N_TYPE[] =
  30 {
  31   N_ABS,
  32   N_TEXT,
  33   N_DATA,
  34   N_BSS,
  35   N_UNDF,                       /* unknown */
  36   N_UNDF,                       /* error */
  37   N_UNDF,                       /* expression */
  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] =
  45 {                               /* N_TYPE == 0x1E = 32-2 */
  46   SEG_UNKNOWN,                  /* N_UNDF == 0 */
  47   SEG_GOOF,
  48   SEG_ABSOLUTE,                 /* N_ABS == 2 */
  49   SEG_GOOF,
  50   SEG_TEXT,                     /* N_TEXT == 4 */
  51   SEG_GOOF,
  52   SEG_DATA,                     /* N_DATA == 6 */
  53   SEG_GOOF,
  54   SEG_BSS,                      /* N_BSS == 8 */
  55   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, SEG_GOOF, SEG_GOOF, SEG_GOOF, SEG_GOOF,
  58   SEG_GOOF, SEG_GOOF, SEG_GOOF, SEG_GOOF,
  59   SEG_REGISTER,                 /* dummy N_REGISTER for regs = 30 */
  60   SEG_GOOF,
  61 };
  62 #endif
  63
  64 static void obj_aout_line PARAMS ((int));
  65 static void obj_aout_weak PARAMS ((int));
  66
  67 const pseudo_typeS obj_pseudo_table[] =
  68 {
  69   {"line", obj_aout_line, 0},   /* source code line number */
  70   {"ln", obj_aout_line, 0},     /* coff line number that we use anyway */
  71
  72   {"weak", obj_aout_weak, 0},   /* mark symbol as weak.  */
  73
  74   /* coff debug pseudos (ignored) */
  75   {"def", s_ignore, 0},
  76   {"dim", s_ignore, 0},
  77   {"endef", s_ignore, 0},
  78   {"ident", s_ignore, 0},
  79   {"line", s_ignore, 0},
  80   {"ln", s_ignore, 0},
  81   {"scl", s_ignore, 0},
  82   {"size", s_ignore, 0},
  83   {"tag", s_ignore, 0},
  84   {"type", s_ignore, 0},
  85   {"val", s_ignore, 0},
  86   {"version", s_ignore, 0},
  87
  88   {"optim", s_ignore, 0},       /* For sun386i cc (?) */
  89
  90   /* other stuff */
  91   {"ABORT", s_abort, 0},
  92
  93   {NULL}                        /* end sentinel */
  94 };                              /* obj_pseudo_table */
  95
  96
  97 #ifdef BFD_ASSEMBLER
  98
  99 void
 100 obj_aout_frob_symbol (sym, punt)
 101      symbolS *sym;
 102      int *punt;
 103 {
 104   flagword flags;
 105   asection *sec;
 106   int desc, type, other;
 107
 108   flags = sym->bsym->flags;
 109   desc = S_GET_DESC (sym);
 110   type = S_GET_TYPE (sym);
 111   other = S_GET_OTHER (sym);
 112   sec = sym->bsym->section;
 113
 114   /* Only frob simple symbols this way right now.  */
 115   if (! (type & ~ (N_TYPE | N_EXT)))
 116     {
 117       if (type == (N_UNDF | N_EXT)
 118           && sec == &bfd_abs_section)
 119         sym->bsym->section = sec = bfd_und_section_ptr;
 120
 121       if ((type & N_TYPE) != N_INDR
 122           && (type & N_TYPE) != N_SETA
 123           && (type & N_TYPE) != N_SETT
 124           && (type & N_TYPE) != N_SETD
 125           && (type & N_TYPE) != N_SETB
 126           && type != N_WARNING
 127           && (sec == &bfd_abs_section
 128               || sec == &bfd_und_section))
 129         return;
 130       if (flags & BSF_EXPORT)
 131         type |= N_EXT;
 132
 133       switch (type & N_TYPE)
 134         {
 135         case N_SETA:
 136         case N_SETT:
 137         case N_SETD:
 138         case N_SETB:
 139           /* Set the debugging flag for constructor symbols so that
 140              BFD leaves them alone.  */
 141           sym->bsym->flags |= BSF_DEBUGGING;
 142
 143           /* You can't put a common symbol in a set.  The way a set
 144              element works is that the symbol has a definition and a
 145              name, and the linker adds the definition to the set of
 146              that name.  That does not work for a common symbol,
 147              because the linker can't tell which common symbol the
 148              user means.  FIXME: Using as_bad here may be
 149              inappropriate, since the user may want to force a
 150              particular type without regard to the semantics of sets;
 151              on the other hand, we certainly don't want anybody to be
 152              mislead into thinking that their code will work.  */
 153           if (S_IS_COMMON (sym))
 154             as_bad ("Attempt to put a common symbol into set %s",
 155                     S_GET_NAME (sym));
 156           /* Similarly, you can't put an undefined symbol in a set.  */
 157           else if (! S_IS_DEFINED (sym))
 158             as_bad ("Attempt to put an undefined symbol into set %s",
 159                     S_GET_NAME (sym));
 160
 161           break;
 162         case N_INDR:
 163           /* Put indirect symbols in the indirect section.  */
 164           sym->bsym->section = bfd_ind_section_ptr;
 165           sym->bsym->flags |= BSF_INDIRECT;
 166           if (type & N_EXT)
 167             {
 168               sym->bsym->flags |= BSF_EXPORT;
 169               sym->bsym->flags &=~ BSF_LOCAL;
 170             }
 171           break;
 172         case N_WARNING:
 173           /* Mark warning symbols.  */
 174           sym->bsym->flags |= BSF_WARNING;
 175           break;
 176         }
 177     }
 178   else
 179     {
 180       sym->bsym->flags |= BSF_DEBUGGING;
 181     }
 182
 183   S_SET_TYPE (sym, type);
 184
 185   /* Double check weak symbols.  */
 186   if (sym->bsym->flags & BSF_WEAK)
 187     {
 188       if (S_IS_COMMON (sym))
 189         as_bad ("Symbol `%s' can not be both weak and common",
 190                 S_GET_NAME (sym));
 191     }
 192 }
 193
 194 void
 195 obj_aout_frob_file ()
 196 {
 197   /* Relocation processing may require knowing the VMAs of the sections.
 198      Since writing to a section will cause the BFD back end to compute the
 199      VMAs, fake it out here....  */
 200   bfd_byte b = 0;
 201   boolean x = true;
 202   if (bfd_section_size (stdoutput, text_section) != 0)
 203     {
 204       x = bfd_set_section_contents (stdoutput, text_section, &b, (file_ptr) 0,
 205                                     (bfd_size_type) 1);
 206     }
 207   else if (bfd_section_size (stdoutput, data_section) != 0)
 208     {
 209       x = bfd_set_section_contents (stdoutput, data_section, &b, (file_ptr) 0,
 210                                     (bfd_size_type) 1);
 211     }
 212   assert (x == true);
 213 }
 214
 215 #else
 216
 217 /* Relocation. */
 218
 219 /*
 220  *              emit_relocations()
 221  *
 222  * Crawl along a fixS chain. Emit the segment's relocations.
 223  */
 224 void
 225 obj_emit_relocations (where, fixP, segment_address_in_file)
 226      char **where;
 227      fixS *fixP;                /* Fixup chain for this segment. */
 228      relax_addressT segment_address_in_file;
 229 {
 230   for (; fixP; fixP = fixP->fx_next)
 231     if (fixP->fx_done == 0)
 232       {
 233         tc_aout_fix_to_chars (*where, fixP, segment_address_in_file);
 234         *where += md_reloc_size;
 235       }
 236 }
 237
 238 #ifndef obj_header_append
 239 /* Aout file generation & utilities */
 240 void
 241 obj_header_append (where, headers)
 242      char **where;
 243      object_headers *headers;
 244 {
 245   tc_headers_hook (headers);
 246
 247 #ifdef CROSS_COMPILE
 248   md_number_to_chars (*where, headers->header.a_info, sizeof (headers->header.a_info));
 249   *where += sizeof (headers->header.a_info);
 250   md_number_to_chars (*where, headers->header.a_text, sizeof (headers->header.a_text));
 251   *where += sizeof (headers->header.a_text);
 252   md_number_to_chars (*where, headers->header.a_data, sizeof (headers->header.a_data));
 253   *where += sizeof (headers->header.a_data);
 254   md_number_to_chars (*where, headers->header.a_bss, sizeof (headers->header.a_bss));
 255   *where += sizeof (headers->header.a_bss);
 256   md_number_to_chars (*where, headers->header.a_syms, sizeof (headers->header.a_syms));
 257   *where += sizeof (headers->header.a_syms);
 258   md_number_to_chars (*where, headers->header.a_entry, sizeof (headers->header.a_entry));
 259   *where += sizeof (headers->header.a_entry);
 260   md_number_to_chars (*where, headers->header.a_trsize, sizeof (headers->header.a_trsize));
 261   *where += sizeof (headers->header.a_trsize);
 262   md_number_to_chars (*where, headers->header.a_drsize, sizeof (headers->header.a_drsize));
 263   *where += sizeof (headers->header.a_drsize);
 264
 265 #else /* CROSS_COMPILE */
 266
 267   append (where, (char *) &headers->header, sizeof (headers->header));
 268 #endif /* CROSS_COMPILE */
 269
 270 }
 271 #endif
 272
 273 void
 274 obj_symbol_to_chars (where, symbolP)
 275      char **where;
 276      symbolS *symbolP;
 277 {
 278   md_number_to_chars ((char *) &(S_GET_OFFSET (symbolP)), S_GET_OFFSET (symbolP), sizeof (S_GET_OFFSET (symbolP)));
 279   md_number_to_chars ((char *) &(S_GET_DESC (symbolP)), S_GET_DESC (symbolP), sizeof (S_GET_DESC (symbolP)));
 280   md_number_to_chars ((char *) &(symbolP->sy_symbol.n_value), S_GET_VALUE (symbolP), sizeof (symbolP->sy_symbol.n_value));
 281
 282   append (where, (char *) &symbolP->sy_symbol, sizeof (obj_symbol_type));
 283 }
 284
 285 void
 286 obj_emit_symbols (where, symbol_rootP)
 287      char **where;
 288      symbolS *symbol_rootP;
 289 {
 290   symbolS *symbolP;
 291
 292   /* Emit all symbols left in the symbol chain.  */
 293   for (symbolP = symbol_rootP; symbolP; symbolP = symbol_next (symbolP))
 294     {
 295       /* Used to save the offset of the name. It is used to point
 296          to the string in memory but must be a file offset. */
 297       register char *temp;
 298
 299       temp = S_GET_NAME (symbolP);
 300       S_SET_OFFSET (symbolP, symbolP->sy_name_offset);
 301
 302       /* Any symbol still undefined and is not a dbg symbol is made N_EXT. */
 303       if (!S_IS_DEBUG (symbolP) && !S_IS_DEFINED (symbolP))
 304         S_SET_EXTERNAL (symbolP);
 305
 306       /* Adjust the type of a weak symbol.  */
 307       if (S_GET_WEAK (symbolP))
 308         {
 309           switch (S_GET_TYPE (symbolP))
 310             {
 311             case N_UNDF: S_SET_TYPE (symbolP, N_WEAKU); break;
 312             case N_ABS:  S_SET_TYPE (symbolP, N_WEAKA); break;
 313             case N_TEXT: S_SET_TYPE (symbolP, N_WEAKT); break;
 314             case N_DATA: S_SET_TYPE (symbolP, N_WEAKD); break;
 315             case N_BSS:  S_SET_TYPE (symbolP, N_WEAKB); break;
 316             default: as_bad ("%s: bad type for weak symbol", temp); break;
 317             }
 318         }
 319
 320       obj_symbol_to_chars (where, symbolP);
 321       S_SET_NAME (symbolP, temp);
 322     }
 323 }
 324
 325 #endif /* ! BFD_ASSEMBLER */
 326
 327 static void
 328 obj_aout_line (ignore)
 329      int ignore;
 330 {
 331   /* Assume delimiter is part of expression.
 332      BSD4.2 as fails with delightful bug, so we
 333      are not being incompatible here. */
 334   new_logical_line ((char *) NULL, (int) (get_absolute_expression ()));
 335   demand_empty_rest_of_line ();
 336 }                               /* obj_aout_line() */
 337
 338 /* Handle .weak.  This is a GNU extension.  */
 339
 340 static void
 341 obj_aout_weak (ignore)
 342      int ignore;
 343 {
 344   char *name;
 345   int c;
 346   symbolS *symbolP;
 347
 348   do
 349     {
 350       name = input_line_pointer;
 351       c = get_symbol_end ();
 352       symbolP = symbol_find_or_make (name);
 353       *input_line_pointer = c;
 354       SKIP_WHITESPACE ();
 355       S_SET_WEAK (symbolP);
 356       if (c == ',')
 357         {
 358           input_line_pointer++;
 359           SKIP_WHITESPACE ();
 360           if (*input_line_pointer == '\n')
 361             c = '\n';
 362         }
 363     }
 364   while (c == ',');
 365   demand_empty_rest_of_line ();
 366 }
 367
 368 void
 369 obj_read_begin_hook ()
 370 {
 371 }
 372
 373 #ifndef BFD_ASSEMBLER
 374
 375 void
 376 obj_crawl_symbol_chain (headers)
 377      object_headers *headers;
 378 {
 379   symbolS *symbolP;
 380   symbolS **symbolPP;
 381   int symbol_number = 0;
 382
 383   tc_crawl_symbol_chain (headers);
 384
 385   symbolPP = &symbol_rootP;     /*->last symbol chain link. */
 386   while ((symbolP = *symbolPP) != NULL)
 387     {
 388       if (flag_readonly_data_in_text && (S_GET_SEGMENT (symbolP) == SEG_DATA))
 389         {
 390           S_SET_SEGMENT (symbolP, SEG_TEXT);
 391         }                       /* if pusing data into text */
 392
 393       resolve_symbol_value (symbolP);
 394
 395       /* OK, here is how we decide which symbols go out into the brave
 396          new symtab.  Symbols that do are:
 397
 398          * symbols with no name (stabd's?)
 399          * symbols with debug info in their N_TYPE
 400
 401          Symbols that don't are:
 402          * symbols that are registers
 403          * symbols with \1 as their 3rd character (numeric labels)
 404          * "local labels" as defined by S_LOCAL_NAME(name) if the -L
 405          switch was passed to gas.
 406
 407          All other symbols are output.  We complain if a deleted
 408          symbol was marked external. */
 409
 410
 411       if (!S_IS_REGISTER (symbolP)
 412           && (!S_GET_NAME (symbolP)
 413               || S_IS_DEBUG (symbolP)
 414               || !S_IS_DEFINED (symbolP)
 415               || S_IS_EXTERNAL (symbolP)
 416               || (S_GET_NAME (symbolP)[0] != '\001'
 417                   && (flag_keep_locals || !S_LOCAL_NAME (symbolP)))))
 418         {
 419           symbolP->sy_number = symbol_number++;
 420
 421           /* The + 1 after strlen account for the \0 at the
 422                            end of each string */
 423           if (!S_IS_STABD (symbolP))
 424             {
 425               /* Ordinary case. */
 426               symbolP->sy_name_offset = string_byte_count;
 427               string_byte_count += strlen (S_GET_NAME (symbolP)) + 1;
 428             }
 429           else                  /* .Stabd case. */
 430             symbolP->sy_name_offset = 0;
 431           symbolPP = &(symbol_next (symbolP));
 432         }
 433       else
 434         {
 435           if (S_IS_EXTERNAL (symbolP) || !S_IS_DEFINED (symbolP))
 436             /* This warning should never get triggered any more.
 437                Well, maybe if you're doing twisted things with
 438                register names...  */
 439             {
 440               as_bad ("Local symbol %s never defined.", decode_local_label_name (S_GET_NAME (symbolP)));
 441             }                   /* oops. */
 442
 443           /* Unhook it from the chain */
 444           *symbolPP = symbol_next (symbolP);
 445         }                       /* if this symbol should be in the output */
 446     }                           /* for each symbol */
 447
 448   H_SET_SYMBOL_TABLE_SIZE (headers, symbol_number);
 449 }
 450
 451 /*
 452  * Find strings by crawling along symbol table chain.
 453  */
 454
 455 void
 456 obj_emit_strings (where)
 457      char **where;
 458 {
 459   symbolS *symbolP;
 460
 461 #ifdef CROSS_COMPILE
 462   /* Gotta do md_ byte-ordering stuff for string_byte_count first - KWK */
 463   md_number_to_chars (*where, string_byte_count, sizeof (string_byte_count));
 464   *where += sizeof (string_byte_count);
 465 #else /* CROSS_COMPILE */
 466   append (where, (char *) &string_byte_count, (unsigned long) sizeof (string_byte_count));
 467 #endif /* CROSS_COMPILE */
 468
 469   for (symbolP = symbol_rootP; symbolP; symbolP = symbol_next (symbolP))
 470     {
 471       if (S_GET_NAME (symbolP))
 472         append (&next_object_file_charP, S_GET_NAME (symbolP),
 473                 (unsigned long) (strlen (S_GET_NAME (symbolP)) + 1));
 474     }                           /* walk symbol chain */
 475 }
 476
 477 #ifndef AOUT_VERSION
 478 #define AOUT_VERSION 0
 479 #endif
 480
 481 void
 482 obj_pre_write_hook (headers)
 483      object_headers *headers;
 484 {
 485   H_SET_DYNAMIC (headers, 0);
 486   H_SET_VERSION (headers, AOUT_VERSION);
 487   H_SET_MACHTYPE (headers, AOUT_MACHTYPE);
 488   tc_aout_pre_write_hook (headers);
 489 }
 490
 491 void
 492 DEFUN_VOID (s_sect)
 493 {
 494   /* Strip out the section name */
 495   char *section_name;
 496   char *section_name_end;
 497   char c;
 498
 499   unsigned int len;
 500   unsigned int exp;
 501   char *save;
 502
 503   section_name = input_line_pointer;
 504   c = get_symbol_end ();
 505   section_name_end = input_line_pointer;
 506
 507   len = section_name_end - section_name;
 508   input_line_pointer++;
 509   save = input_line_pointer;
 510
 511   SKIP_WHITESPACE ();
 512   if (c == ',')
 513     {
 514       exp = get_absolute_expression ();
 515     }
 516   else if (*input_line_pointer == ',')
 517     {
 518       input_line_pointer++;
 519       exp = get_absolute_expression ();
 520     }
 521   else
 522     {
 523       input_line_pointer = save;
 524       exp = 0;
 525     }
 526   if (exp >= 1000)
 527     {
 528       as_bad ("subsegment index too high");
 529     }
 530
 531   if (strcmp (section_name, ".text") == 0)
 532     {
 533       subseg_set (SEG_TEXT, (subsegT) exp);
 534     }
 535
 536   if (strcmp (section_name, ".data") == 0)
 537     {
 538       if (flag_readonly_data_in_text)
 539         subseg_set (SEG_TEXT, (subsegT) exp + 1000);
 540       else
 541         subseg_set (SEG_DATA, (subsegT) exp);
 542     }
 543
 544   *section_name_end = c;
 545 }
 546
 547 #endif /* ! BFD_ASSEMBLER */
 548
 549 /* end of obj-aout.c */