gas/cond.c

   1 /* cond.c - conditional assembly pseudo-ops, and .include
   2    Copyright (C) 1990, 91, 92, 93, 95, 96, 97, 98, 99, 2000
   3    Free Software Foundation, Inc.
   4
   5    This file is part of GAS, the GNU Assembler.
   6
   7    GAS is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 2, or (at your option)
  10    any later version.
  11
  12    GAS is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with GAS; see the file COPYING.  If not, write to the Free
  19    Software Foundation, 59 Temple Place - Suite 330, Boston, MA
  20    02111-1307, USA.  */
  21
  22 #include "as.h"
  23 #include "macro.h"
  24
  25 #include "obstack.h"
  26
  27 /* This is allocated to grow and shrink as .ifdef/.endif pairs are scanned. */
  28 struct obstack cond_obstack;
  29
  30 struct file_line
  31 {
  32   char *file;
  33   unsigned int line;
  34 };
  35
  36 /* We push one of these structures for each .if, and pop it at the
  37    .endif.  */
  38
  39 struct conditional_frame
  40 {
  41   /* The source file & line number of the "if".  */
  42   struct file_line if_file_line;
  43   /* The source file & line of the "else".  */
  44   struct file_line else_file_line;
  45   /* The previous conditional.  */
  46   struct conditional_frame *previous_cframe;
  47   /* Have we seen an else yet?  */
  48   int else_seen;
  49   /* Whether we are currently ignoring input.  */
  50   int ignoring;
  51   /* Whether a conditional at a higher level is ignoring input.  */
  52   int dead_tree;
  53   /* Macro nesting level at which this conditional was created.  */
  54   int macro_nest;
  55 };
  56
  57 static void initialize_cframe PARAMS ((struct conditional_frame *cframe));
  58 static char *get_mri_string PARAMS ((int, int *));
  59
  60 static struct conditional_frame *current_cframe = NULL;
  61
  62 void
  63 s_ifdef (arg)
  64      int arg;
  65 {
  66   register char *name;          /* points to name of symbol */
  67   register symbolS *symbolP;    /* Points to symbol */
  68   struct conditional_frame cframe;
  69
  70   SKIP_WHITESPACE ();           /* Leading whitespace is part of operand. */
  71   name = input_line_pointer;
  72
  73   if (!is_name_beginner (*name))
  74     {
  75       as_bad (_("invalid identifier for \".ifdef\""));
  76       obstack_1grow (&cond_obstack, 0);
  77       ignore_rest_of_line ();
  78     }
  79   else
  80     {
  81       char c;
  82
  83       c = get_symbol_end ();
  84       symbolP = symbol_find (name);
  85       *input_line_pointer = c;
  86
  87       initialize_cframe (&cframe);
  88       cframe.ignoring = cframe.dead_tree || !((symbolP != 0) ^ arg);
  89       current_cframe = ((struct conditional_frame *)
  90                         obstack_copy (&cond_obstack, &cframe,
  91                                       sizeof (cframe)));
  92
  93       if (LISTING_SKIP_COND ()
  94           && cframe.ignoring
  95           && (cframe.previous_cframe == NULL
  96               || ! cframe.previous_cframe->ignoring))
  97         listing_list (2);
  98
  99       demand_empty_rest_of_line ();
 100     }                           /* if a valid identifyer name */
 101 }                               /* s_ifdef() */
 102
 103 void
 104 s_if (arg)
 105      int arg;
 106 {
 107   expressionS operand;
 108   struct conditional_frame cframe;
 109   int t;
 110   char *stop = NULL;
 111   char stopc;
 112
 113   if (flag_mri)
 114     stop = mri_comment_field (&stopc);
 115
 116   SKIP_WHITESPACE ();           /* Leading whitespace is part of operand. */
 117
 118   if (current_cframe != NULL && current_cframe->ignoring)
 119     {
 120       operand.X_add_number = 0;
 121       while (! is_end_of_line[(unsigned char) *input_line_pointer])
 122         ++input_line_pointer;
 123     }
 124   else
 125     {
 126       expression (&operand);
 127       if (operand.X_op != O_constant)
 128         as_bad (_("non-constant expression in \".if\" statement"));
 129     }
 130
 131   switch ((operatorT) arg)
 132     {
 133     case O_eq: t = operand.X_add_number == 0; break;
 134     case O_ne: t = operand.X_add_number != 0; break;
 135     case O_lt: t = operand.X_add_number < 0; break;
 136     case O_le: t = operand.X_add_number <= 0; break;
 137     case O_ge: t = operand.X_add_number >= 0; break;
 138     case O_gt: t = operand.X_add_number > 0; break;
 139     default:
 140       abort ();
 141       return;
 142     }
 143
 144   /* If the above error is signaled, this will dispatch
 145      using an undefined result.  No big deal.  */
 146   initialize_cframe (&cframe);
 147   cframe.ignoring = cframe.dead_tree || ! t;
 148   current_cframe = ((struct conditional_frame *)
 149                     obstack_copy (&cond_obstack, &cframe, sizeof (cframe)));
 150
 151   if (LISTING_SKIP_COND ()
 152       && cframe.ignoring
 153       && (cframe.previous_cframe == NULL
 154           || ! cframe.previous_cframe->ignoring))
 155     listing_list (2);
 156
 157   if (flag_mri)
 158     mri_comment_end (stop, stopc);
 159
 160   demand_empty_rest_of_line ();
 161 }                               /* s_if() */
 162
 163 /* Get a string for the MRI IFC or IFNC pseudo-ops.  */
 164
 165 static char *
 166 get_mri_string (terminator, len)
 167      int terminator;
 168      int *len;
 169 {
 170   char *ret;
 171   char *s;
 172
 173   SKIP_WHITESPACE ();
 174   s = ret = input_line_pointer;
 175   if (*input_line_pointer == '\'')
 176     {
 177       ++s;
 178       ++input_line_pointer;
 179       while (! is_end_of_line[(unsigned char) *input_line_pointer])
 180         {
 181           *s++ = *input_line_pointer++;
 182           if (s[-1] == '\'')
 183             {
 184               if (*input_line_pointer != '\'')
 185                 break;
 186               ++input_line_pointer;
 187             }
 188         }
 189       SKIP_WHITESPACE ();
 190     }
 191   else
 192     {
 193       while (*input_line_pointer != terminator
 194              && ! is_end_of_line[(unsigned char) *input_line_pointer])
 195         ++input_line_pointer;
 196       s = input_line_pointer;
 197       while (s > ret && (s[-1] == ' ' || s[-1] == '\t'))
 198         --s;
 199     }
 200
 201   *len = s - ret;
 202   return ret;
 203 }
 204
 205 /* The MRI IFC and IFNC pseudo-ops.  */
 206
 207 void
 208 s_ifc (arg)
 209      int arg;
 210 {
 211   char *stop = NULL;
 212   char stopc;
 213   char *s1, *s2;
 214   int len1, len2;
 215   int res;
 216   struct conditional_frame cframe;
 217
 218   if (flag_mri)
 219     stop = mri_comment_field (&stopc);
 220
 221   s1 = get_mri_string (',', &len1);
 222
 223   if (*input_line_pointer != ',')
 224     as_bad (_("bad format for ifc or ifnc"));
 225   else
 226     ++input_line_pointer;
 227
 228   s2 = get_mri_string (';', &len2);
 229
 230   res = len1 == len2 && strncmp (s1, s2, len1) == 0;
 231
 232   initialize_cframe (&cframe);
 233   cframe.ignoring = cframe.dead_tree || ! (res ^ arg);
 234   current_cframe = ((struct conditional_frame *)
 235                     obstack_copy (&cond_obstack, &cframe, sizeof (cframe)));
 236
 237   if (LISTING_SKIP_COND ()
 238       && cframe.ignoring
 239       && (cframe.previous_cframe == NULL
 240           || ! cframe.previous_cframe->ignoring))
 241     listing_list (2);
 242
 243   if (flag_mri)
 244     mri_comment_end (stop, stopc);
 245
 246   demand_empty_rest_of_line ();
 247 }
 248
 249 void
 250 s_elseif (arg)
 251      int arg;
 252 {
 253   expressionS operand;
 254   int t;
 255
 256   if (current_cframe == NULL)
 257     {
 258       as_bad (_("\".elseif\" without matching \".if\" - ignored"));
 259
 260     }
 261   else if (current_cframe->else_seen)
 262     {
 263       as_bad (_("\".elseif\" after \".else\" - ignored"));
 264       as_bad_where (current_cframe->else_file_line.file,
 265                     current_cframe->else_file_line.line,
 266                     _("here is the previous \"else\""));
 267       as_bad_where (current_cframe->if_file_line.file,
 268                     current_cframe->if_file_line.line,
 269                     _("here is the previous \"if\""));
 270     }
 271   else
 272     {
 273       as_where (&current_cframe->else_file_line.file,
 274                 &current_cframe->else_file_line.line);
 275
 276       if (!current_cframe->dead_tree)
 277         {
 278           current_cframe->ignoring = !current_cframe->ignoring;
 279           if (LISTING_SKIP_COND ())
 280             {
 281               if (! current_cframe->ignoring)
 282                 listing_list (1);
 283               else
 284                 listing_list (2);
 285             }
 286         }                       /* if not a dead tree */
 287     }                           /* if error else do it */
 288
 289
 290   SKIP_WHITESPACE ();           /* Leading whitespace is part of operand. */
 291
 292   if (current_cframe != NULL && current_cframe->ignoring)
 293     {
 294       operand.X_add_number = 0;
 295       while (! is_end_of_line[(unsigned char) *input_line_pointer])
 296         ++input_line_pointer;
 297     }
 298   else
 299     {
 300       expression (&operand);
 301       if (operand.X_op != O_constant)
 302         as_bad (_("non-constant expression in \".elseif\" statement"));
 303     }
 304
 305   switch ((operatorT) arg)
 306     {
 307     case O_eq: t = operand.X_add_number == 0; break;
 308     case O_ne: t = operand.X_add_number != 0; break;
 309     case O_lt: t = operand.X_add_number < 0; break;
 310     case O_le: t = operand.X_add_number <= 0; break;
 311     case O_ge: t = operand.X_add_number >= 0; break;
 312     case O_gt: t = operand.X_add_number > 0; break;
 313     default:
 314       abort ();
 315       return;
 316     }
 317
 318   current_cframe->ignoring = current_cframe->dead_tree || ! t;
 319
 320   if (LISTING_SKIP_COND ()
 321       && current_cframe->ignoring
 322       && (current_cframe->previous_cframe == NULL
 323           || ! current_cframe->previous_cframe->ignoring))
 324     listing_list (2);
 325
 326   demand_empty_rest_of_line ();
 327 }
 328
 329 void
 330 s_endif (arg)
 331      int arg ATTRIBUTE_UNUSED;
 332 {
 333   struct conditional_frame *hold;
 334
 335   if (current_cframe == NULL)
 336     {
 337       as_bad (_("\".endif\" without \".if\""));
 338     }
 339   else
 340     {
 341       if (LISTING_SKIP_COND ()
 342           && current_cframe->ignoring
 343           && (current_cframe->previous_cframe == NULL
 344               || ! current_cframe->previous_cframe->ignoring))
 345         listing_list (1);
 346
 347       hold = current_cframe;
 348       current_cframe = current_cframe->previous_cframe;
 349       obstack_free (&cond_obstack, hold);
 350     }                           /* if one pop too many */
 351
 352   if (flag_mri)
 353     {
 354       while (! is_end_of_line[(unsigned char) *input_line_pointer])
 355         ++input_line_pointer;
 356     }
 357
 358   demand_empty_rest_of_line ();
 359 }                               /* s_endif() */
 360
 361 void
 362 s_else (arg)
 363      int arg ATTRIBUTE_UNUSED;
 364 {
 365   if (current_cframe == NULL)
 366     {
 367       as_bad (_(".else without matching .if - ignored"));
 368
 369     }
 370   else if (current_cframe->else_seen)
 371     {
 372       as_bad (_("duplicate \"else\" - ignored"));
 373       as_bad_where (current_cframe->else_file_line.file,
 374                     current_cframe->else_file_line.line,
 375                     _("here is the previous \"else\""));
 376       as_bad_where (current_cframe->if_file_line.file,
 377                     current_cframe->if_file_line.line,
 378                     _("here is the previous \"if\""));
 379     }
 380   else
 381     {
 382       as_where (&current_cframe->else_file_line.file,
 383                 &current_cframe->else_file_line.line);
 384
 385       if (!current_cframe->dead_tree)
 386         {
 387           current_cframe->ignoring = !current_cframe->ignoring;
 388           if (LISTING_SKIP_COND ())
 389             {
 390               if (! current_cframe->ignoring)
 391                 listing_list (1);
 392               else
 393                 listing_list (2);
 394             }
 395         }                       /* if not a dead tree */
 396
 397       current_cframe->else_seen = 1;
 398     }                           /* if error else do it */
 399
 400   if (flag_mri)
 401     {
 402       while (! is_end_of_line[(unsigned char) *input_line_pointer])
 403         ++input_line_pointer;
 404     }
 405
 406   demand_empty_rest_of_line ();
 407 }                               /* s_else() */
 408
 409 void
 410 s_ifeqs (arg)
 411      int arg;
 412 {
 413   char *s1, *s2;
 414   int len1, len2;
 415   int res;
 416   struct conditional_frame cframe;
 417
 418   s1 = demand_copy_C_string (&len1);
 419
 420   SKIP_WHITESPACE ();
 421   if (*input_line_pointer != ',')
 422     {
 423       as_bad (_(".ifeqs syntax error"));
 424       ignore_rest_of_line ();
 425       return;
 426     }
 427
 428   ++input_line_pointer;
 429
 430   s2 = demand_copy_C_string (&len2);
 431
 432   res = len1 == len2 && strncmp (s1, s2, len1) == 0;
 433
 434   initialize_cframe (&cframe);
 435   cframe.ignoring = cframe.dead_tree || ! (res ^ arg);
 436   current_cframe = ((struct conditional_frame *)
 437                     obstack_copy (&cond_obstack, &cframe, sizeof (cframe)));
 438
 439   if (LISTING_SKIP_COND ()
 440       && cframe.ignoring
 441       && (cframe.previous_cframe == NULL
 442           || ! cframe.previous_cframe->ignoring))
 443     listing_list (2);
 444
 445   demand_empty_rest_of_line ();
 446 }                               /* s_ifeqs() */
 447
 448 int
 449 ignore_input ()
 450 {
 451   char *s;
 452
 453   s = input_line_pointer;
 454
 455   if (NO_PSEUDO_DOT || flag_m68k_mri)
 456     {
 457       if (s[-1] != '.')
 458         --s;
 459     }
 460   else
 461     {
 462       if (s[-1] != '.')
 463         return (current_cframe != NULL) && (current_cframe->ignoring);
 464     }
 465
 466   /* We cannot ignore certain pseudo ops.  */
 467   if (((s[0] == 'i'
 468         || s[0] == 'I')
 469        && (!strncasecmp (s, "if", 2)
 470            || !strncasecmp (s, "ifdef", 5)
 471            || !strncasecmp (s, "ifndef", 6)))
 472       || ((s[0] == 'e'
 473            || s[0] == 'E')
 474           && (!strncasecmp (s, "else", 4)
 475               || !strncasecmp (s, "endif", 5)
 476               || !strncasecmp (s, "endc", 4))))
 477     return 0;
 478
 479   return (current_cframe != NULL) && (current_cframe->ignoring);
 480 }                               /* ignore_input() */
 481
 482 static void
 483 initialize_cframe (cframe)
 484      struct conditional_frame *cframe;
 485 {
 486   memset (cframe, 0, sizeof (*cframe));
 487   as_where (&cframe->if_file_line.file,
 488             &cframe->if_file_line.line);
 489   cframe->previous_cframe = current_cframe;
 490   cframe->dead_tree = current_cframe != NULL && current_cframe->ignoring;
 491   cframe->macro_nest = macro_nest;
 492 }
 493
 494 /* Give an error if a conditional is unterminated inside a macro or
 495    the assembly as a whole.  If NEST is non negative, we are being
 496    called because of the end of a macro expansion.  If NEST is
 497    negative, we are being called at the of the input files.  */
 498
 499 void
 500 cond_finish_check (nest)
 501      int nest;
 502 {
 503   if (current_cframe != NULL && current_cframe->macro_nest >= nest)
 504     {
 505       if (nest >= 0)
 506         as_bad (_("end of macro inside conditional"));
 507       else
 508         as_bad (_("end of file inside conditional"));
 509       as_bad_where (current_cframe->if_file_line.file,
 510                     current_cframe->if_file_line.line,
 511                     _("here is the start of the unterminated conditional"));
 512       if (current_cframe->else_seen)
 513         as_bad_where (current_cframe->else_file_line.file,
 514                       current_cframe->else_file_line.line,
 515                       _("here is the \"else\" of the unterminated conditional"));
 516     }
 517 }
 518
 519 /* This function is called when we exit out of a macro.  We assume
 520    that any conditionals which began within the macro are correctly
 521    nested, and just pop them off the stack.  */
 522
 523 void
 524 cond_exit_macro (nest)
 525      int nest;
 526 {
 527   while (current_cframe != NULL && current_cframe->macro_nest >= nest)
 528     {
 529       struct conditional_frame *hold;
 530
 531       hold = current_cframe;
 532       current_cframe = current_cframe->previous_cframe;
 533       obstack_free (&cond_obstack, hold);
 534     }
 535 }
 536
 537 /* end of cond.c */