gas/as.c

   1 /* as.c - GAS main program.
   2    Copyright (C) 1987, 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 published by
   8    the Free Software Foundation; either version 2, or (at your option)
   9    any later version.
  10
  11    GAS is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with GAS; see the file COPYING.  If not, write to
  18    the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
  19
  20 /*
  21  * Main program for AS; a 32-bit assembler of GNU.
  22  * Understands command arguments.
  23  * Has a few routines that don't fit in other modules because they
  24  * are shared.
  25  *
  26  *
  27  *                      bugs
  28  *
  29  * : initialisers
  30  *      Since no-one else says they will support them in future: I
  31  * don't support them now.
  32  *
  33  */
  34
  35 #include <stdio.h>
  36 #include <string.h>
  37
  38 #ifdef _POSIX_SOURCE
  39 #include <sys/types.h>          /* For pid_t in signal.h */
  40 #endif
  41 #include <signal.h>
  42
  43 #define COMMON
  44
  45 #include "as.h"
  46 #include "config.h"
  47 #include "subsegs.h"
  48 #include "output-file.h"
  49
  50 #ifndef SIGTY
  51 #ifdef __STDC__
  52 #define SIGTY void
  53 #else
  54 #define SIGTY int
  55 #endif /* __STDC__ */
  56 #endif /* SIGTY */
  57
  58 #if 0
  59 /* Not currently used.  */
  60 static SIGTY got_sig PARAMS ((int sig));
  61 #endif
  62 static void perform_an_assembly_pass PARAMS ((int argc, char **argv));
  63
  64 #ifndef EXIT_SUCCESS
  65 #define EXIT_SUCCESS 0
  66 #define EXIT_FAILURE 1
  67 #endif
  68
  69 int listing;                    /* true if a listing is wanted */
  70
  71 char *myname;                   /* argv[0] */
  72 #ifdef BFD_ASSEMBLER
  73 segT reg_section, expr_section;
  74 segT text_section, data_section, bss_section;
  75 #endif
  76 \f
  77 void
  78 print_version_id ()
  79 {
  80   static int printed;
  81   if (printed)
  82     return;
  83   printed = 1;
  84
  85   fprintf (stderr, "GNU assembler version %s (%s)", GAS_VERSION, TARGET_ALIAS);
  86 #ifdef BFD_ASSEMBLER
  87   fprintf (stderr, ", using BFD version %s", BFD_VERSION);
  88 #endif
  89   fprintf (stderr, "\n");
  90 }
  91
  92 int
  93 main (argc, argv)
  94      int argc;
  95      char **argv;
  96 {
  97   int work_argc;                /* variable copy of argc */
  98   char **work_argv;             /* variable copy of argv */
  99   char *arg;                    /* an arg to program */
 100   char a;                       /* an arg flag (after -) */
 101
 102 #if 0 /* do we need any of this?? */
 103   {
 104     static const int sig[] = {SIGHUP, SIGINT, SIGPIPE, SIGTERM, 0};
 105
 106     for (a = 0; sig[a] != 0; a++)
 107       if (signal (sig[a], SIG_IGN) != SIG_IGN)
 108         signal (sig[a], got_sig);
 109   }
 110 #endif
 111
 112   myname = argv[0];
 113   memset (flagseen, '\0', sizeof (flagseen));   /* aint seen nothing yet */
 114 #ifndef OBJ_DEFAULT_OUTPUT_FILE_NAME
 115 #define OBJ_DEFAULT_OUTPUT_FILE_NAME "a.out"
 116 #endif
 117   out_file_name = OBJ_DEFAULT_OUTPUT_FILE_NAME;
 118
 119 #ifdef BFD_ASSEMBLER
 120   bfd_init ();
 121 #endif
 122
 123   symbol_begin ();
 124   subsegs_begin ();
 125   read_begin ();
 126   input_scrub_begin ();
 127   frag_init ();
 128   /*
 129    * Parse arguments, but we are only interested in flags.
 130    * When we find a flag, we process it then make it's argv[] NULL.
 131    * This helps any future argv[] scanners avoid what we processed.
 132    * Since it is easy to do here we interpret the special arg "-"
 133    * to mean "use stdin" and we set that argv[] pointing to "".
 134    * After we have munged argv[], the only things left are source file
 135    * name(s) and ""(s) denoting stdin. These file names are used
 136    * (perhaps more than once) later.
 137    */
 138   /* FIXME-SOMEDAY this should use getopt. */
 139   work_argc = argc - 1;         /* don't count argv[0] */
 140   work_argv = argv + 1;         /* skip argv[0] */
 141   for (; work_argc--; work_argv++)
 142     {
 143       arg = *work_argv;         /* work_argv points to this argument */
 144
 145       if (*arg != '-')          /* Filename. We need it later. */
 146         continue;               /* Keep scanning args looking for flags. */
 147       if (arg[1] == '-' && arg[2] == 0)
 148         {
 149           /* "--" as an argument means read STDIN */
 150           /* on this scan, we don't want to think about filenames */
 151           *work_argv = "";      /* Code that means 'use stdin'. */
 152           continue;
 153         }
 154       /* This better be a switch. */
 155       arg++;                    /*->letter. */
 156
 157       while ((a = *arg) != '\0')
 158         {                       /* scan all the 1-char flags */
 159           arg++;                /* arg->after letter. */
 160           a &= 0x7F;            /* ascii only please */
 161           flagseen[(unsigned char) a] = 1;
 162           switch (a)
 163             {
 164             case 'a':
 165               {
 166                 int loop = 1;
 167
 168                 while (loop)
 169                   {
 170                     switch (*arg)
 171                       {
 172                       case 'l':
 173                         listing |= LISTING_LISTING;
 174                         arg++;
 175                         break;
 176                       case 's':
 177                         listing |= LISTING_SYMBOLS;
 178                         arg++;
 179                         break;
 180                       case 'h':
 181                         listing |= LISTING_HLL;
 182                         arg++;
 183                         break;
 184
 185                       case 'n':
 186                         listing |= LISTING_NOFORM;
 187                         arg++;
 188                         break;
 189                       case 'd':
 190                         listing |= LISTING_NODEBUG;
 191                         arg++;
 192                         break;
 193                       default:
 194                         if (!listing)
 195                           listing = LISTING_DEFAULT;
 196                         loop = 0;
 197                         break;
 198                       }
 199                   }
 200               }
 201
 202               break;
 203
 204
 205             case 'f':
 206               break;            /* -f means fast - no need for "app" preprocessor. */
 207
 208             case 'D':
 209               /* DEBUG is implemented: it debugs different */
 210               /* things to other people's assemblers. */
 211               break;
 212
 213             case 'I':
 214               {                 /* Include file directory */
 215
 216                 char *temp = NULL;
 217                 if (*arg)
 218                   {
 219                     temp = strdup (arg);
 220                     if (!temp)
 221                       as_fatal ("virtual memory exhausted");
 222                   }
 223                 else if (work_argc)
 224                   {
 225                     *work_argv = NULL;
 226                     work_argc--;
 227                     temp = *++work_argv;
 228                   }
 229                 else
 230                   as_warn ("%s: I expected a filename after -I", myname);
 231                 add_include_dir (temp);
 232                 arg = "";       /* Finished with this arg. */
 233                 break;
 234               }
 235
 236 #ifdef WARN_SIGNED_OVERFLOW_WORD
 237               /* Don't warn about signed overflow.  */
 238             case 'J':
 239               break;
 240 #endif
 241
 242 #ifndef WORKING_DOT_WORD
 243             case 'K':
 244               break;
 245 #endif
 246
 247             case 'L':           /* -L means keep L* symbols */
 248               break;
 249
 250             case 'o':
 251               if (*arg)         /* Rest of argument is object file-name. */
 252                 {
 253                   out_file_name = strdup (arg);
 254                   if (!out_file_name)
 255                     as_fatal ("virtual memory exhausted");
 256                 }
 257               else if (work_argc)
 258                 {               /* Want next arg for a file-name. */
 259                   *work_argv = NULL;    /* This is not a file-name. */
 260                   work_argc--;
 261                   out_file_name = *++work_argv;
 262                 }
 263               else
 264                 as_warn ("%s: I expected a filename after -o. \"%s\" assumed.",
 265                          myname, out_file_name);
 266               arg = "";         /* Finished with this arg. */
 267               break;
 268
 269             case 'R':
 270               /* -R means put data into text segment */
 271               flag_readonly_data_in_text = 1;
 272               break;
 273
 274             case 'v':
 275 #ifdef  VMS
 276               {
 277                 extern char *compiler_version_string;
 278                 compiler_version_string = arg;
 279               }
 280 #else /* not VMS */
 281               if (*arg && strcmp (arg, "ersion"))
 282                 {
 283                   as_warn ("Unknown option `-v%s' ignored", arg);
 284                   arg += strlen (arg);
 285                   break;
 286                 }
 287
 288               print_version_id ();
 289 #endif /* not VMS */
 290               while (*arg)
 291                 arg++;          /* Skip the rest */
 292               break;
 293
 294             case 'W':
 295               /* -W means don't warn about things */
 296               flag_suppress_warnings = 1;
 297               break;
 298
 299             case 'w':
 300             case 'X':
 301               /* -X means treat warnings as errors */
 302               break;
 303             case 'Z':
 304               /* -Z means attempt to generate object file even after errors. */
 305               flag_always_generate_output = 1;
 306               break;
 307
 308             default:
 309               --arg;
 310               if (md_parse_option (&arg, &work_argc, &work_argv) == 0)
 311                 as_warn ("%s: I don't understand '%c' flag.", myname, a);
 312               if (arg && *arg)
 313                 arg++;
 314               break;
 315             }
 316         }
 317       /*
 318        * We have just processed a "-..." arg, which was not a
 319        * file-name. Smash it so the
 320        * things that look for filenames won't ever see it.
 321        *
 322        * Whatever work_argv points to, it has already been used
 323        * as part of a flag, so DON'T re-use it as a filename.
 324        */
 325       *work_argv = NULL;        /* NULL means 'not a file-name' */
 326     }
 327
 328 #ifdef BFD_ASSEMBLER
 329   output_file_create (out_file_name);
 330   assert (stdoutput != 0);
 331 #endif
 332
 333   /* Here with flags set up in flagseen[]. */
 334   perform_an_assembly_pass (argc, argv);        /* Assemble it. */
 335 #ifdef TC_I960
 336   brtab_emit ();
 337 #endif
 338
 339 #ifndef NO_LISTING
 340   listing_print ("");
 341 #endif
 342
 343   if (seen_at_least_1_file ()
 344       && !((had_warnings () && flag_always_generate_output)
 345            || had_errors () > 0))
 346     {
 347       write_object_file ();     /* relax() addresses then emit object file */
 348     }                           /* we also check in write_object_file() just before emit. */
 349 #ifdef BFD_ASSEMBLER
 350   else
 351     {
 352       output_file_close (out_file_name);
 353       unlink (out_file_name);
 354     }
 355 #endif
 356
 357   input_scrub_end ();
 358   md_end ();                    /* MACHINE.c */
 359
 360   if ((had_warnings () && flagseen['Z'])
 361       || had_errors () > 0)
 362     return EXIT_FAILURE;
 363   return EXIT_SUCCESS;
 364 }
 365 \f
 366
 367 /*                      perform_an_assembly_pass()
 368  *
 369  * Here to attempt 1 pass over each input file.
 370  * We scan argv[*] looking for filenames or exactly "" which is
 371  * shorthand for stdin. Any argv that is NULL is not a file-name.
 372  * We set need_pass_2 TRUE if, after this, we still have unresolved
 373  * expressions of the form (unknown value)+-(unknown value).
 374  *
 375  * Note the un*x semantics: there is only 1 logical input file, but it
 376  * may be a catenation of many 'physical' input files.
 377  */
 378 static void
 379 perform_an_assembly_pass (argc, argv)
 380      int argc;
 381      char **argv;
 382 {
 383   int saw_a_file = 0;
 384 #ifdef BFD_ASSEMBLER
 385   flagword applicable;
 386 #endif
 387
 388   need_pass_2 = 0;
 389
 390 #ifndef BFD_ASSEMBLER
 391 #ifdef MANY_SEGMENTS
 392   {
 393     unsigned int i;
 394     for (i = SEG_E0; i < SEG_UNKNOWN; i++)
 395       segment_info[i].fix_root = 0;
 396   }
 397   /* Create the three fixed ones */
 398   {
 399     segT seg;
 400
 401     seg = subseg_new (".text", 0);
 402     assert (seg == SEG_E0);
 403     seg = subseg_new (".data", 0);
 404     assert (seg == SEG_E1);
 405     seg = subseg_new (".bss", 0);
 406     assert (seg == SEG_E2);
 407   }
 408
 409 #else /* not MANY_SEGMENTS */
 410   text_fix_root = NULL;
 411   data_fix_root = NULL;
 412   bss_fix_root = NULL;
 413 #endif /* not MANY_SEGMENTS */
 414 #else /* BFD_ASSEMBLER */
 415   /* Create the standard sections, and those the assembler uses
 416      internally.  */
 417   text_section = subseg_new (".text", 0);
 418   data_section = subseg_new (".data", 0);
 419   bss_section = subseg_new (".bss", 0);
 420   /* @@ FIXME -- we're setting the RELOC flag so that sections are assumed
 421      to have relocs, otherwise we don't find out in time. */
 422   applicable = bfd_applicable_section_flags (stdoutput);
 423   bfd_set_section_flags (stdoutput, text_section,
 424                          applicable & (SEC_ALLOC | SEC_LOAD | SEC_RELOC
 425                                        | SEC_CODE | SEC_READONLY));
 426   /* @@ FIXME -- SEC_CODE seems to mean code only, rather than code possibly.*/
 427   bfd_set_section_flags (stdoutput, data_section,
 428                          applicable & (SEC_ALLOC | SEC_LOAD | SEC_RELOC));
 429   bfd_set_section_flags (stdoutput, bss_section, applicable & SEC_ALLOC);
 430   seg_info (bss_section)->bss = 1;
 431   subseg_new (BFD_ABS_SECTION_NAME, 0);
 432   subseg_new (BFD_UND_SECTION_NAME, 0);
 433   reg_section = subseg_new ("*GAS `reg' section*", 0);
 434   expr_section = subseg_new ("*GAS `expr' section*", 0);
 435
 436 #endif /* BFD_ASSEMBLER */
 437
 438   subseg_set (text_section, 0);
 439
 440   /* This may add symbol table entries, which requires having an open BFD,
 441      and sections already created, in BFD_ASSEMBLER mode.  */
 442   md_begin ();
 443
 444   argv++;                       /* skip argv[0] */
 445   argc--;                       /* skip argv[0] */
 446   while (argc--)
 447     {
 448       if (*argv)
 449         {                       /* Is it a file-name argument? */
 450           saw_a_file++;
 451           /* argv->"" if stdin desired, else->filename */
 452           read_a_source_file (*argv);
 453         }
 454       argv++;                   /* completed that argv */
 455     }
 456   if (!saw_a_file)
 457     read_a_source_file ("");
 458 }                               /* perform_an_assembly_pass() */
 459 \f
 460 #if 0
 461 /* This is not currently used.  */
 462 static SIGTY
 463 got_sig (sig)
 464      int sig;
 465 {
 466   static here_before = 0;
 467
 468   as_bad ("Interrupted by signal %d", sig);
 469   if (here_before++)
 470     exit (EXIT_FAILURE);
 471 #if 0 /* If SIGTY is void, this produces warnings.  */
 472   return ((SIGTY) 0);
 473 #endif
 474 }
 475 #endif
 476
 477 /* end of as.c */