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
  49 #if __STDC__ == 1
  50
  51 /* This prototype for got_sig() is ansi.  If you want
  52    anything else, then your compiler is lying to you when
  53    it says that it is __STDC__.  If you want to change it,
  54    #ifdef protect it from those of us with real ansi
  55    compilers. */
  56
  57 #define SIGTY void
  58
  59 static void got_sig (int sig);
  60 static void perform_an_assembly_pass (int argc, char **argv);
  61
  62 #else /* __STDC__ */
  63
  64 #ifndef SIGTY
  65 #define SIGTY int
  66 #endif
  67
  68 static SIGTY got_sig ();
  69 static void perform_an_assembly_pass ();
  70
  71 #endif /* not __STDC__ */
  72
  73 #ifndef EXIT_SUCCESS
  74 #define EXIT_SUCCESS 0
  75 #define EXIT_FAILURE 1
  76 #endif
  77
  78 int listing;                    /* true if a listing is wanted */
  79
  80 char *myname;                   /* argv[0] */
  81 #ifdef BFD_ASSEMBLER
  82 segT big_section, reg_section, pass1_section;
  83 segT diff_section, absent_section;
  84 segT text_section, data_section, bss_section;
  85 #endif
  86 \f
  87 int
  88 main (argc, argv)
  89      int argc;
  90      char **argv;
  91 {
  92   int work_argc;                /* variable copy of argc */
  93   char **work_argv;             /* variable copy of argv */
  94   char *arg;                    /* an arg to program */
  95   char a;                       /* an arg flag (after -) */
  96
  97 #if 0 /* do we need any of this?? */
  98   {
  99     static const int sig[] = {SIGHUP, SIGINT, SIGPIPE, SIGTERM, 0};
 100
 101     for (a = 0; sig[a] != 0; a++)
 102       if (signal (sig[a], SIG_IGN) != SIG_IGN)
 103         signal (sig[a], got_sig);
 104   }
 105 #endif
 106
 107   myname = argv[0];
 108   memset (flagseen, '\0', sizeof (flagseen));   /* aint seen nothing yet */
 109 #ifndef OBJ_DEFAULT_OUTPUT_FILE_NAME
 110 #define OBJ_DEFAULT_OUTPUT_FILE_NAME "a.out"
 111 #endif
 112   out_file_name = OBJ_DEFAULT_OUTPUT_FILE_NAME;
 113
 114 #ifdef BFD_ASSEMBLER
 115   bfd_init ();
 116 #endif
 117
 118   symbol_begin ();
 119   subsegs_begin ();
 120   read_begin ();
 121   md_begin ();
 122   input_scrub_begin ();
 123   frag_init ();
 124   /*
 125    * Parse arguments, but we are only interested in flags.
 126    * When we find a flag, we process it then make it's argv[] NULL.
 127    * This helps any future argv[] scanners avoid what we processed.
 128    * Since it is easy to do here we interpret the special arg "-"
 129    * to mean "use stdin" and we set that argv[] pointing to "".
 130    * After we have munged argv[], the only things left are source file
 131    * name(s) and ""(s) denoting stdin. These file names are used
 132    * (perhaps more than once) later.
 133    */
 134   /* FIXME-SOMEDAY this should use getopt. */
 135   work_argc = argc - 1;         /* don't count argv[0] */
 136   work_argv = argv + 1;         /* skip argv[0] */
 137   for (; work_argc--; work_argv++)
 138     {
 139       arg = *work_argv;         /* work_argv points to this argument */
 140
 141       if (*arg != '-')          /* Filename. We need it later. */
 142         continue;               /* Keep scanning args looking for flags. */
 143       if (arg[1] == '-' && arg[2] == 0)
 144         {
 145           /* "--" as an argument means read STDIN */
 146           /* on this scan, we don't want to think about filenames */
 147           *work_argv = "";      /* Code that means 'use stdin'. */
 148           continue;
 149         }
 150       /* This better be a switch. */
 151       arg++;                    /*->letter. */
 152
 153       while ((a = *arg) != '\0')
 154         {                       /* scan all the 1-char flags */
 155           arg++;                /* arg->after letter. */
 156           a &= 0x7F;            /* ascii only please */
 157           flagseen[a] = 1;
 158           switch (a)
 159             {
 160             case 'a':
 161               {
 162                 int loop = 1;
 163
 164                 while (loop)
 165                   {
 166                     switch (*arg)
 167                       {
 168                       case 'l':
 169                         listing |= LISTING_LISTING;
 170                         arg++;
 171                         break;
 172                       case 's':
 173                         listing |= LISTING_SYMBOLS;
 174                         arg++;
 175                         break;
 176                       case 'h':
 177                         listing |= LISTING_HLL;
 178                         arg++;
 179                         break;
 180
 181                       case 'n':
 182                         listing |= LISTING_NOFORM;
 183                         arg++;
 184                         break;
 185                       case 'd':
 186                         listing |= LISTING_NODEBUG;
 187                         arg++;
 188                         break;
 189                       default:
 190                         if (!listing)
 191                           listing = LISTING_DEFAULT;
 192                         loop = 0;
 193                         break;
 194                       }
 195                   }
 196               }
 197
 198               break;
 199
 200
 201             case 'f':
 202               break;            /* -f means fast - no need for "app" preprocessor. */
 203
 204             case 'D':
 205               /* DEBUG is implemented: it debugs different */
 206               /* things to other people's assemblers. */
 207               break;
 208
 209             case 'I':
 210               {                 /* Include file directory */
 211
 212                 char *temp = NULL;
 213                 if (*arg)
 214                   {
 215                     temp = strdup (arg);
 216                     if (!temp)
 217                       as_fatal ("virtual memory exhuasted");
 218                   }
 219                 else if (work_argc)
 220                   {
 221                     *work_argv = NULL;
 222                     work_argc--;
 223                     temp = *++work_argv;
 224                   }
 225                 else
 226                   as_warn ("%s: I expected a filename after -I", myname);
 227                 add_include_dir (temp);
 228                 arg = "";       /* Finished with this arg. */
 229                 break;
 230               }
 231
 232 #ifdef WARN_SIGNED_OVERFLOW_WORD
 233               /* Don't warn about signed overflow.  */
 234             case 'J':
 235               break;
 236 #endif
 237
 238 #ifndef WORKING_DOT_WORD
 239             case 'K':
 240               break;
 241 #endif
 242
 243             case 'L':           /* -L means keep L* symbols */
 244               break;
 245
 246             case 'o':
 247               if (*arg)         /* Rest of argument is object file-name. */
 248                 {
 249                   out_file_name = strdup (arg);
 250                   if (!out_file_name)
 251                     as_fatal ("virtual memory exhausted");
 252                 }
 253               else if (work_argc)
 254                 {               /* Want next arg for a file-name. */
 255                   *work_argv = NULL;    /* This is not a file-name. */
 256                   work_argc--;
 257                   out_file_name = *++work_argv;
 258                 }
 259               else
 260                 as_warn ("%s: I expected a filename after -o. \"%s\" assumed.",
 261                          myname, out_file_name);
 262               arg = "";         /* Finished with this arg. */
 263               break;
 264
 265             case 'R':
 266               /* -R means put data into text segment */
 267               flag_readonly_data_in_text = 1;
 268               break;
 269
 270             case 'v':
 271 #ifdef  VMS
 272               {
 273                 extern char *compiler_version_string;
 274                 compiler_version_string = arg;
 275               }
 276 #else /* not VMS */
 277               if (*arg && strcmp (arg, "ersion"))
 278                 {
 279                   as_warn ("Unknown -v option ignored");
 280                   arg += strlen (arg);
 281                   break;
 282                 }
 283
 284               fprintf (stderr, "GNU assembler version %s (%s)",
 285                        GAS_VERSION, TARGET_ALIAS);
 286 #ifdef BFD_ASSEMBLER
 287               fprintf (stderr, ", using BFD version %s", BFD_VERSION);
 288 #endif
 289               fprintf (stderr, "\n");
 290 #endif /* not VMS */
 291               while (*arg)
 292                 arg++;          /* Skip the rest */
 293               break;
 294
 295             case 'W':
 296               /* -W means don't warn about things */
 297               flag_suppress_warnings = 1;
 298               break;
 299
 300             case 'w':
 301             case 'X':
 302               /* -X means treat warnings as errors */
 303               break;
 304             case 'Z':
 305               /* -Z means attempt to generate object file even after errors. */
 306               flag_always_generate_output = 1;
 307               break;
 308
 309             default:
 310               --arg;
 311               if (md_parse_option (&arg, &work_argc, &work_argv) == 0)
 312                 as_warn ("%s: I don't understand '%c' flag.", myname, a);
 313               if (arg && *arg)
 314                 arg++;
 315               break;
 316             }
 317         }
 318       /*
 319        * We have just processed a "-..." arg, which was not a
 320        * file-name. Smash it so the
 321        * things that look for filenames won't ever see it.
 322        *
 323        * Whatever work_argv points to, it has already been used
 324        * as part of a flag, so DON'T re-use it as a filename.
 325        */
 326       *work_argv = NULL;        /* NULL means 'not a file-name' */
 327     }
 328
 329 #ifdef BFD_ASSEMBLER
 330   output_file_create (out_file_name);
 331   assert (stdoutput != 0);
 332 #endif
 333
 334   /* Here with flags set up in flagseen[]. */
 335   perform_an_assembly_pass (argc, argv);        /* Assemble it. */
 336 #ifdef TC_I960
 337   brtab_emit ();
 338 #endif
 339   if (seen_at_least_1_file ()
 340       && !((had_warnings () && flag_always_generate_output)
 341            || had_errors () > 0))
 342     {
 343       write_object_file ();     /* relax() addresses then emit object file */
 344     }                           /* we also check in write_object_file() just before emit. */
 345
 346   input_scrub_end ();
 347   md_end ();                    /* MACHINE.c */
 348
 349 #ifndef NO_LISTING
 350   listing_print ("");
 351 #endif
 352
 353   if ((had_warnings () && flagseen['Z'])
 354       || had_errors () > 0)
 355     return EXIT_FAILURE;
 356   return EXIT_SUCCESS;
 357 }
 358 \f
 359
 360 /*                      perform_an_assembly_pass()
 361  *
 362  * Here to attempt 1 pass over each input file.
 363  * We scan argv[*] looking for filenames or exactly "" which is
 364  * shorthand for stdin. Any argv that is NULL is not a file-name.
 365  * We set need_pass_2 TRUE if, after this, we still have unresolved
 366  * expressions of the form (unknown value)+-(unknown value).
 367  *
 368  * Note the un*x semantics: there is only 1 logical input file, but it
 369  * may be a catenation of many 'physical' input files.
 370  */
 371 static void
 372 perform_an_assembly_pass (argc, argv)
 373      int argc;
 374      char **argv;
 375 {
 376   int saw_a_file = 0;
 377   unsigned int i;
 378 #ifdef BFD_ASSEMBLER
 379   flagword applicable;
 380 #endif
 381
 382   need_pass_2 = 0;
 383
 384 #ifndef BFD_ASSEMBLER
 385 #ifdef MANY_SEGMENTS
 386   for (i = SEG_E0; i < SEG_UNKNOWN; i++)
 387     {
 388       segment_info[i].fix_root = 0;
 389     }
 390   /* Create the three fixed ones */
 391   subseg_new (SEG_E0, 0);
 392   subseg_new (SEG_E1, 0);
 393   subseg_new (SEG_E2, 0);
 394   strcpy (segment_info[SEG_E0].scnhdr.s_name, ".text");
 395   strcpy (segment_info[SEG_E1].scnhdr.s_name, ".data");
 396   strcpy (segment_info[SEG_E2].scnhdr.s_name, ".bss");
 397
 398   subseg_new (SEG_E0, 0);
 399 #else /* not MANY_SEGMENTS */
 400   text_fix_root = NULL;
 401   data_fix_root = NULL;
 402   bss_fix_root = NULL;
 403
 404   subseg_new (SEG_TEXT, 0);
 405 #endif /* not MANY_SEGMENTS */
 406 #else /* BFD_ASSEMBLER */
 407   /* Create the standard sections, and those the assembler uses
 408      internally.  */
 409   text_section = subseg_new (".text", 0);
 410   text_section->output_section = text_section;
 411   data_section = subseg_new (".data", 0);
 412   data_section->output_section = data_section;
 413   bss_section = subseg_new (".bss", 0);
 414   bss_section->output_section = bss_section;
 415   /* @@ FIXME -- we're setting the RELOC flag so that sections are assumed
 416      to have relocs, otherwise we don't find out in time. */
 417   applicable = bfd_applicable_section_flags (stdoutput);
 418   bfd_set_section_flags (stdoutput, text_section,
 419                          applicable & (SEC_ALLOC | SEC_LOAD | SEC_RELOC
 420                                        | SEC_CODE | SEC_READONLY));
 421   /* @@ FIXME -- SEC_CODE seems to mean code only, rather than code possibly.*/
 422   bfd_set_section_flags (stdoutput, data_section,
 423                          applicable & (SEC_ALLOC | SEC_LOAD | SEC_RELOC));
 424   bfd_set_section_flags (stdoutput, bss_section, applicable & SEC_ALLOC);
 425   subseg_new (BFD_ABS_SECTION_NAME, 0);
 426   subseg_new (BFD_UND_SECTION_NAME, 0);
 427   big_section = subseg_new ("*GAS `big' section*", 0);
 428   reg_section = subseg_new ("*GAS `reg' section*", 0);
 429   pass1_section = subseg_new ("*GAS `pass1' section*", 0);
 430   diff_section = subseg_new ("*GAS `diff' section*", 0);
 431   absent_section = subseg_new ("*GAS `absent' section*", 0);
 432
 433   subseg_new (".text", 0);
 434 #endif /* BFD_ASSEMBLER */
 435
 436   argv++;                       /* skip argv[0] */
 437   argc--;                       /* skip argv[0] */
 438   while (argc--)
 439     {
 440       if (*argv)
 441         {                       /* Is it a file-name argument? */
 442           saw_a_file++;
 443           /* argv->"" if stdin desired, else->filename */
 444           read_a_source_file (*argv);
 445         }
 446       argv++;                   /* completed that argv */
 447     }
 448   if (!saw_a_file)
 449     read_a_source_file ("");
 450 }                               /* perform_an_assembly_pass() */
 451 \f
 452 static SIGTY
 453 got_sig (sig)
 454      int sig;
 455 {
 456   static here_before = 0;
 457
 458   as_bad ("Interrupted by signal %d", sig);
 459   if (here_before++)
 460     exit (EXIT_FAILURE);
 461   return ((SIGTY) 0);
 462 }
 463
 464 /* end of as.c */