parser.c

   1 /* parser.c   source line parser for the Netwide Assembler
   2  *
   3  * The Netwide Assembler is copyright (C) 1996 Simon Tatham and
   4  * Julian Hall. All rights reserved. The software is
   5  * redistributable under the licence given in the file "Licence"
   6  * distributed in the NASM archive.
   7  *
   8  * initial version 27/iii/95 by Simon Tatham
   9  */
  10
  11 #include "compiler.h"
  12
  13 #include <stdio.h>
  14 #include <stdlib.h>
  15 #include <stddef.h>
  16 #include <string.h>
  17 #include <ctype.h>
  18 #include <inttypes.h>
  19
  20 #include "nasm.h"
  21 #include "insns.h"
  22 #include "nasmlib.h"
  23 #include "stdscan.h"
  24 #include "parser.h"
  25 #include "float.h"
  26
  27 extern int in_abs_seg;          /* ABSOLUTE segment flag */
  28 extern int32_t abs_seg;            /* ABSOLUTE segment */
  29 extern int32_t abs_offset;         /* ABSOLUTE segment offset */
  30
  31 #include "regflags.c"           /* List of register flags */
  32
  33 static int is_comma_next(void);
  34
  35 static int i;
  36 static struct tokenval tokval;
  37 static efunc error;
  38 static struct ofmt *outfmt;     /* Structure of addresses of output routines */
  39 static struct location *location;         /* Pointer to current line's segment,offset */
  40
  41 void parser_global_info(struct ofmt *output, struct location * locp)
  42 {
  43     outfmt = output;
  44     location = locp;
  45 }
  46
  47 static int prefix_slot(enum prefixes prefix)
  48 {
  49     switch (prefix) {
  50     case R_CS:
  51     case R_DS:
  52     case R_SS:
  53     case R_ES:
  54     case R_FS:
  55     case R_GS:
  56         return PPS_SEG;
  57     case P_LOCK:
  58     case P_REP:
  59     case P_REPE:
  60     case P_REPZ:
  61     case P_REPNE:
  62     case P_REPNZ:
  63         return PPS_LREP;
  64     case P_O16:
  65     case P_O32:
  66     case P_O64:
  67     case P_OSP:
  68         return PPS_OSIZE;
  69     case P_A16:
  70     case P_A32:
  71     case P_A64:
  72     case P_ASP:
  73         return PPS_ASIZE;
  74     default:
  75         error(ERR_PANIC, "Invalid value %d passed to prefix_slot()", prefix);
  76         return -1;
  77     }
  78 }
  79
  80 static void process_size_override(insn * result, int operand)
  81 {
  82     if (tasm_compatible_mode) {
  83         switch ((int)tokval.t_integer) {
  84             /* For TASM compatibility a size override inside the
  85              * brackets changes the size of the operand, not the
  86              * address type of the operand as it does in standard
  87              * NASM syntax. Hence:
  88              *
  89              *  mov     eax,[DWORD val]
  90              *
  91              * is valid syntax in TASM compatibility mode. Note that
  92              * you lose the ability to override the default address
  93              * type for the instruction, but we never use anything
  94              * but 32-bit flat model addressing in our code.
  95              */
  96         case S_BYTE:
  97             result->oprs[operand].type |= BITS8;
  98             break;
  99         case S_WORD:
 100             result->oprs[operand].type |= BITS16;
 101             break;
 102         case S_DWORD:
 103         case S_LONG:
 104             result->oprs[operand].type |= BITS32;
 105             break;
 106         case S_QWORD:
 107             result->oprs[operand].type |= BITS64;
 108             break;
 109         case S_TWORD:
 110             result->oprs[operand].type |= BITS80;
 111             break;
 112         case S_OWORD:
 113             result->oprs[operand].type |= BITS128;
 114             break;
 115         default:
 116             error(ERR_NONFATAL,
 117                   "invalid operand size specification");
 118             break;
 119         }
 120     } else {
 121         /* Standard NASM compatible syntax */
 122         switch ((int)tokval.t_integer) {
 123         case S_NOSPLIT:
 124             result->oprs[operand].eaflags |= EAF_TIMESTWO;
 125             break;
 126         case S_REL:
 127             result->oprs[operand].eaflags |= EAF_REL;
 128             break;
 129         case S_ABS:
 130             result->oprs[operand].eaflags |= EAF_ABS;
 131             break;
 132         case S_BYTE:
 133             result->oprs[operand].disp_size = 8;
 134             result->oprs[operand].eaflags |= EAF_BYTEOFFS;
 135             break;
 136         case P_A16:
 137         case P_A32:
 138         case P_A64:
 139             if (result->prefixes[PPS_ASIZE] &&
 140                 result->prefixes[PPS_ASIZE] != tokval.t_integer)
 141                 error(ERR_NONFATAL,
 142                       "conflicting address size specifications");
 143             else
 144                 result->prefixes[PPS_ASIZE] = tokval.t_integer;
 145             break;
 146         case S_WORD:
 147             result->oprs[operand].disp_size = 16;
 148             result->oprs[operand].eaflags |= EAF_WORDOFFS;
 149             break;
 150         case S_DWORD:
 151         case S_LONG:
 152             result->oprs[operand].disp_size = 32;
 153             result->oprs[operand].eaflags |= EAF_WORDOFFS;
 154             break;
 155         case S_QWORD:
 156             result->oprs[operand].disp_size = 64;
 157             result->oprs[operand].eaflags |= EAF_WORDOFFS;
 158             break;
 159         default:
 160             error(ERR_NONFATAL, "invalid size specification in"
 161                   " effective address");
 162             break;
 163         }
 164     }
 165 }
 166
 167 insn *parse_line(int pass, char *buffer, insn * result,
 168                  efunc errfunc, evalfunc evaluate, ldfunc ldef)
 169 {
 170     int operand;
 171     int critical;
 172     struct eval_hints hints;
 173     int j;
 174
 175     result->forw_ref = false;
 176     error = errfunc;
 177
 178     stdscan_reset();
 179     stdscan_bufptr = buffer;
 180     i = stdscan(NULL, &tokval);
 181
 182     result->label = NULL;       /* Assume no label */
 183     result->eops = NULL;        /* must do this, whatever happens */
 184     result->operands = 0;       /* must initialize this */
 185
 186     if (i == 0) {               /* blank line - ignore */
 187         result->opcode = -1;    /* and no instruction either */
 188         return result;
 189     }
 190     if (i != TOKEN_ID && i != TOKEN_INSN && i != TOKEN_PREFIX &&
 191         (i != TOKEN_REG || (REG_SREG & ~reg_flags[tokval.t_integer]))) {
 192         error(ERR_NONFATAL, "label or instruction expected"
 193               " at start of line");
 194         result->opcode = -1;
 195         return result;
 196     }
 197
 198     if (i == TOKEN_ID) {        /* there's a label here */
 199         result->label = tokval.t_charptr;
 200         i = stdscan(NULL, &tokval);
 201         if (i == ':') {         /* skip over the optional colon */
 202             i = stdscan(NULL, &tokval);
 203         } else if (i == 0) {
 204             error(ERR_WARNING | ERR_WARN_OL | ERR_PASS1,
 205                   "label alone on a line without a colon might be in error");
 206         }
 207         if (i != TOKEN_INSN || tokval.t_integer != I_EQU) {
 208             /*
 209              * FIXME: location->segment could be NO_SEG, in which case
 210              * it is possible we should be passing 'abs_seg'. Look into this.
 211              * Work out whether that is *really* what we should be doing.
 212              * Generally fix things. I think this is right as it is, but
 213              * am still not certain.
 214              */
 215             ldef(result->label, in_abs_seg ? abs_seg : location->segment,
 216                  location->offset, NULL, true, false, outfmt, errfunc);
 217         }
 218     }
 219
 220     if (i == 0) {
 221         result->opcode = -1;    /* this line contains just a label */
 222         return result;
 223     }
 224
 225     for (j = 0; j < MAXPREFIX; j++)
 226         result->prefixes[j] = P_none;
 227     result->times = 1L;
 228
 229     while (i == TOKEN_PREFIX ||
 230            (i == TOKEN_REG && !(REG_SREG & ~reg_flags[tokval.t_integer])))
 231     {
 232         /*
 233          * Handle special case: the TIMES prefix.
 234          */
 235         if (i == TOKEN_PREFIX && tokval.t_integer == P_TIMES) {
 236             expr *value;
 237
 238             i = stdscan(NULL, &tokval);
 239             value =
 240                 evaluate(stdscan, NULL, &tokval, NULL, pass0, error, NULL);
 241             i = tokval.t_type;
 242             if (!value) {       /* but, error in evaluator */
 243                 result->opcode = -1;    /* unrecoverable parse error: */
 244                 return result;  /* ignore this instruction */
 245             }
 246             if (!is_simple(value)) {
 247                 error(ERR_NONFATAL,
 248                       "non-constant argument supplied to TIMES");
 249                 result->times = 1L;
 250             } else {
 251                 result->times = value->value;
 252                 if (value->value < 0) {
 253                     error(ERR_NONFATAL, "TIMES value %d is negative",
 254                           value->value);
 255                     result->times = 0;
 256                 }
 257             }
 258         } else {
 259             int slot = prefix_slot(tokval.t_integer);
 260             if (result->prefixes[slot]) {
 261                if (result->prefixes[slot] == tokval.t_integer)
 262                     error(ERR_WARNING,
 263                       "instruction has redundant prefixes");
 264                else
 265                     error(ERR_NONFATAL,
 266                       "instruction has conflicting prefixes");
 267             }
 268             result->prefixes[slot] = tokval.t_integer;
 269             i = stdscan(NULL, &tokval);
 270         }
 271     }
 272
 273     if (i != TOKEN_INSN) {
 274         int j;
 275         enum prefixes pfx;
 276
 277         for (j = 0; j < MAXPREFIX; j++)
 278             if ((pfx = result->prefixes[j]) != P_none)
 279                 break;
 280
 281         if (i == 0 && pfx != P_none) {
 282             /*
 283              * Instruction prefixes are present, but no actual
 284              * instruction. This is allowed: at this point we
 285              * invent a notional instruction of RESB 0.
 286              */
 287             result->opcode = I_RESB;
 288             result->operands = 1;
 289             result->oprs[0].type = IMMEDIATE;
 290             result->oprs[0].offset = 0L;
 291             result->oprs[0].segment = result->oprs[0].wrt = NO_SEG;
 292             return result;
 293         } else {
 294             error(ERR_NONFATAL, "parser: instruction expected");
 295             result->opcode = -1;
 296             return result;
 297         }
 298     }
 299
 300     result->opcode = tokval.t_integer;
 301     result->condition = tokval.t_inttwo;
 302
 303     /*
 304      * RESB, RESW and RESD cannot be satisfied with incorrectly
 305      * evaluated operands, since the correct values _must_ be known
 306      * on the first pass. Hence, even in pass one, we set the
 307      * `critical' flag on calling evaluate(), so that it will bomb
 308      * out on undefined symbols. Nasty, but there's nothing we can
 309      * do about it.
 310      *
 311      * For the moment, EQU has the same difficulty, so we'll
 312      * include that.
 313      */
 314     if (result->opcode == I_RESB || result->opcode == I_RESW ||
 315         result->opcode == I_RESD || result->opcode == I_RESQ ||
 316         result->opcode == I_REST || result->opcode == I_RESO ||
 317         result->opcode == I_EQU || result->opcode == I_INCBIN) {
 318         critical = pass0;
 319     } else
 320         critical = (pass == 2 ? 2 : 0);
 321
 322     if (result->opcode == I_DB || result->opcode == I_DW ||
 323         result->opcode == I_DD || result->opcode == I_DQ ||
 324         result->opcode == I_DT || result->opcode == I_DO ||
 325         result->opcode == I_INCBIN) {
 326         extop *eop, **tail = &result->eops, **fixptr;
 327         int oper_num = 0;
 328
 329         result->eops_float = false;
 330
 331         /*
 332          * Begin to read the DB/DW/DD/DQ/DT/DO/INCBIN operands.
 333          */
 334         while (1) {
 335             i = stdscan(NULL, &tokval);
 336             if (i == 0)
 337                 break;
 338             fixptr = tail;
 339             eop = *tail = nasm_malloc(sizeof(extop));
 340             tail = &eop->next;
 341             eop->next = NULL;
 342             eop->type = EOT_NOTHING;
 343             oper_num++;
 344
 345             if (i == TOKEN_NUM && tokval.t_charptr && is_comma_next()) {
 346                 eop->type = EOT_DB_STRING;
 347                 eop->stringval = tokval.t_charptr;
 348                 eop->stringlen = tokval.t_inttwo;
 349                 i = stdscan(NULL, &tokval);     /* eat the comma */
 350                 continue;
 351             }
 352
 353             if ((i == TOKEN_FLOAT && is_comma_next())
 354                 || i == '-' || i == '+') {
 355                 int32_t sign = +1;
 356
 357                 if (i == '+' || i == '-') {
 358                     char *save = stdscan_bufptr;
 359                     int token = i;
 360                     sign = (i == '-') ? -1 : 1;
 361                     i = stdscan(NULL, &tokval);
 362                     if (i != TOKEN_FLOAT || !is_comma_next()) {
 363                         stdscan_bufptr = save;
 364                         i = tokval.t_type = token;
 365                     }
 366                 }
 367
 368                 if (i == TOKEN_FLOAT) {
 369                     eop->type = EOT_DB_STRING;
 370                     result->eops_float = true;
 371                     switch (result->opcode) {
 372                     case I_DB:
 373                         eop->stringlen = 1;
 374                         break;
 375                     case I_DW:
 376                         eop->stringlen = 2;
 377                         break;
 378                     case I_DD:
 379                         eop->stringlen = 4;
 380                         break;
 381                     case I_DQ:
 382                         eop->stringlen = 8;
 383                         break;
 384                     case I_DT:
 385                         eop->stringlen = 10;
 386                         break;
 387                     case I_DO:
 388                         eop->stringlen = 16;
 389                         break;
 390                     default:
 391                         error(ERR_NONFATAL, "floating-point constant"
 392                               " encountered in unknown instruction");
 393                         /*
 394                          * fix suggested by Pedro Gimeno... original line
 395                          * was:
 396                          * eop->type = EOT_NOTHING;
 397                          */
 398                         eop->stringlen = 0;
 399                         break;
 400                     }
 401                     eop = nasm_realloc(eop, sizeof(extop) + eop->stringlen);
 402                     tail = &eop->next;
 403                     *fixptr = eop;
 404                     eop->stringval = (char *)eop + sizeof(extop);
 405                     if (!eop->stringlen ||
 406                         !float_const(tokval.t_charptr, sign,
 407                                      (uint8_t *)eop->stringval,
 408                                      eop->stringlen, error))
 409                         eop->type = EOT_NOTHING;
 410                     i = stdscan(NULL, &tokval); /* eat the comma */
 411                     continue;
 412                 }
 413             }
 414
 415             /* anything else */
 416             {
 417                 expr *value;
 418                 value = evaluate(stdscan, NULL, &tokval, NULL,
 419                                  critical, error, NULL);
 420                 i = tokval.t_type;
 421                 if (!value) {   /* error in evaluator */
 422                     result->opcode = -1;        /* unrecoverable parse error: */
 423                     return result;      /* ignore this instruction */
 424                 }
 425                 if (is_unknown(value)) {
 426                     eop->type = EOT_DB_NUMBER;
 427                     eop->offset = 0;    /* doesn't matter what we put */
 428                     eop->segment = eop->wrt = NO_SEG;   /* likewise */
 429                 } else if (is_reloc(value)) {
 430                     eop->type = EOT_DB_NUMBER;
 431                     eop->offset = reloc_value(value);
 432                     eop->segment = reloc_seg(value);
 433                     eop->wrt = reloc_wrt(value);
 434                 } else {
 435                     error(ERR_NONFATAL,
 436                           "operand %d: expression is not simple"
 437                           " or relocatable", oper_num);
 438                 }
 439             }
 440
 441             /*
 442              * We're about to call stdscan(), which will eat the
 443              * comma that we're currently sitting on between
 444              * arguments. However, we'd better check first that it
 445              * _is_ a comma.
 446              */
 447             if (i == 0)         /* also could be EOL */
 448                 break;
 449             if (i != ',') {
 450                 error(ERR_NONFATAL, "comma expected after operand %d",
 451                       oper_num);
 452                 result->opcode = -1;    /* unrecoverable parse error: */
 453                 return result;  /* ignore this instruction */
 454             }
 455         }
 456
 457         if (result->opcode == I_INCBIN) {
 458             /*
 459              * Correct syntax for INCBIN is that there should be
 460              * one string operand, followed by one or two numeric
 461              * operands.
 462              */
 463             if (!result->eops || result->eops->type != EOT_DB_STRING)
 464                 error(ERR_NONFATAL, "`incbin' expects a file name");
 465             else if (result->eops->next &&
 466                      result->eops->next->type != EOT_DB_NUMBER)
 467                 error(ERR_NONFATAL, "`incbin': second parameter is",
 468                       " non-numeric");
 469             else if (result->eops->next && result->eops->next->next &&
 470                      result->eops->next->next->type != EOT_DB_NUMBER)
 471                 error(ERR_NONFATAL, "`incbin': third parameter is",
 472                       " non-numeric");
 473             else if (result->eops->next && result->eops->next->next &&
 474                      result->eops->next->next->next)
 475                 error(ERR_NONFATAL,
 476                       "`incbin': more than three parameters");
 477             else
 478                 return result;
 479             /*
 480              * If we reach here, one of the above errors happened.
 481              * Throw the instruction away.
 482              */
 483             result->opcode = -1;
 484             return result;
 485         } else /* DB ... */ if (oper_num == 0)
 486             error(ERR_WARNING | ERR_PASS1,
 487                   "no operand for data declaration");
 488         else
 489             result->operands = oper_num;
 490
 491         return result;
 492     }
 493
 494     /* right. Now we begin to parse the operands. There may be up to four
 495      * of these, separated by commas, and terminated by a zero token. */
 496
 497     for (operand = 0; operand < MAX_OPERANDS; operand++) {
 498         expr *value;            /* used most of the time */
 499         int mref;               /* is this going to be a memory ref? */
 500         int bracket;            /* is it a [] mref, or a & mref? */
 501         int setsize = 0;
 502
 503         result->oprs[operand].disp_size = 0;    /* have to zero this whatever */
 504         result->oprs[operand].eaflags = 0;      /* and this */
 505         result->oprs[operand].opflags = 0;
 506
 507         i = stdscan(NULL, &tokval);
 508         if (i == 0)
 509             break;              /* end of operands: get out of here */
 510         result->oprs[operand].type = 0; /* so far, no override */
 511         while (i == TOKEN_SPECIAL) {    /* size specifiers */
 512             switch ((int)tokval.t_integer) {
 513             case S_BYTE:
 514                 if (!setsize)   /* we want to use only the first */
 515                     result->oprs[operand].type |= BITS8;
 516                 setsize = 1;
 517                 break;
 518             case S_WORD:
 519                 if (!setsize)
 520                     result->oprs[operand].type |= BITS16;
 521                 setsize = 1;
 522                 break;
 523             case S_DWORD:
 524             case S_LONG:
 525                 if (!setsize)
 526                     result->oprs[operand].type |= BITS32;
 527                 setsize = 1;
 528                 break;
 529             case S_QWORD:
 530                 if (!setsize)
 531                     result->oprs[operand].type |= BITS64;
 532                 setsize = 1;
 533                 break;
 534             case S_TWORD:
 535                 if (!setsize)
 536                     result->oprs[operand].type |= BITS80;
 537                 setsize = 1;
 538                 break;
 539             case S_OWORD:
 540                 if (!setsize)
 541                     result->oprs[operand].type |= BITS128;
 542                 setsize = 1;
 543                 break;
 544             case S_TO:
 545                 result->oprs[operand].type |= TO;
 546                 break;
 547             case S_STRICT:
 548                 result->oprs[operand].type |= STRICT;
 549                 break;
 550             case S_FAR:
 551                 result->oprs[operand].type |= FAR;
 552                 break;
 553             case S_NEAR:
 554                 result->oprs[operand].type |= NEAR;
 555                 break;
 556             case S_SHORT:
 557                 result->oprs[operand].type |= SHORT;
 558                 break;
 559             default:
 560                 error(ERR_NONFATAL, "invalid operand size specification");
 561             }
 562             i = stdscan(NULL, &tokval);
 563         }
 564
 565         if (i == '[' || i == '&') {     /* memory reference */
 566             mref = true;
 567             bracket = (i == '[');
 568             i = stdscan(NULL, &tokval); /* then skip the colon */
 569             while (i == TOKEN_SPECIAL || i == TOKEN_PREFIX) {
 570                 process_size_override(result, operand);
 571                 i = stdscan(NULL, &tokval);
 572             }
 573         } else {                /* immediate operand, or register */
 574             mref = false;
 575             bracket = false;    /* placate optimisers */
 576         }
 577
 578         if ((result->oprs[operand].type & FAR) && !mref &&
 579             result->opcode != I_JMP && result->opcode != I_CALL) {
 580             error(ERR_NONFATAL, "invalid use of FAR operand specifier");
 581         }
 582
 583         value = evaluate(stdscan, NULL, &tokval,
 584                          &result->oprs[operand].opflags,
 585                          critical, error, &hints);
 586         i = tokval.t_type;
 587         if (result->oprs[operand].opflags & OPFLAG_FORWARD) {
 588             result->forw_ref = true;
 589         }
 590         if (!value) {           /* error in evaluator */
 591             result->opcode = -1;        /* unrecoverable parse error: */
 592             return result;      /* ignore this instruction */
 593         }
 594         if (i == ':' && mref) { /* it was seg:offset */
 595             /*
 596              * Process the segment override.
 597              */
 598             if (value[1].type != 0 || value->value != 1 ||
 599                 REG_SREG & ~reg_flags[value->type])
 600                 error(ERR_NONFATAL, "invalid segment override");
 601             else if (result->prefixes[PPS_SEG])
 602                 error(ERR_NONFATAL,
 603                       "instruction has conflicting segment overrides");
 604             else {
 605                 result->prefixes[PPS_SEG] = value->type;
 606                 if (!(REG_FSGS & ~reg_flags[value->type]))
 607                     result->oprs[operand].eaflags |= EAF_FSGS;
 608             }
 609
 610             i = stdscan(NULL, &tokval); /* then skip the colon */
 611             while (i == TOKEN_SPECIAL || i == TOKEN_PREFIX) {
 612                 process_size_override(result, operand);
 613                 i = stdscan(NULL, &tokval);
 614             }
 615             value = evaluate(stdscan, NULL, &tokval,
 616                              &result->oprs[operand].opflags,
 617                              critical, error, &hints);
 618             i = tokval.t_type;
 619             if (result->oprs[operand].opflags & OPFLAG_FORWARD) {
 620                 result->forw_ref = true;
 621             }
 622             /* and get the offset */
 623             if (!value) {       /* but, error in evaluator */
 624                 result->opcode = -1;    /* unrecoverable parse error: */
 625                 return result;  /* ignore this instruction */
 626             }
 627         }
 628         if (mref && bracket) {  /* find ] at the end */
 629             if (i != ']') {
 630                 error(ERR_NONFATAL, "parser: expecting ]");
 631                 do {            /* error recovery again */
 632                     i = stdscan(NULL, &tokval);
 633                 } while (i != 0 && i != ',');
 634             } else              /* we got the required ] */
 635                 i = stdscan(NULL, &tokval);
 636         } else {                /* immediate operand */
 637             if (i != 0 && i != ',' && i != ':') {
 638                 error(ERR_NONFATAL, "comma or end of line expected");
 639                 do {            /* error recovery */
 640                     i = stdscan(NULL, &tokval);
 641                 } while (i != 0 && i != ',');
 642             } else if (i == ':') {
 643                 result->oprs[operand].type |= COLON;
 644             }
 645         }
 646
 647         /* now convert the exprs returned from evaluate() into operand
 648          * descriptions... */
 649
 650         if (mref) {             /* it's a memory reference */
 651             expr *e = value;
 652             int b, i, s;        /* basereg, indexreg, scale */
 653             int64_t o;             /* offset */
 654
 655             b = i = -1, o = s = 0;
 656             result->oprs[operand].hintbase = hints.base;
 657             result->oprs[operand].hinttype = hints.type;
 658
 659             if (e->type && e->type <= EXPR_REG_END) {   /* this bit's a register */
 660                 if (e->value == 1)      /* in fact it can be basereg */
 661                     b = e->type;
 662                 else            /* no, it has to be indexreg */
 663                     i = e->type, s = e->value;
 664                 e++;
 665             }
 666             if (e->type && e->type <= EXPR_REG_END) {   /* it's a 2nd register */
 667                 if (b != -1)    /* If the first was the base, ... */
 668                     i = e->type, s = e->value;  /* second has to be indexreg */
 669
 670                 else if (e->value != 1) {       /* If both want to be index */
 671                     error(ERR_NONFATAL,
 672                           "beroset-p-592-invalid effective address");
 673                     result->opcode = -1;
 674                     return result;
 675                 } else
 676                     b = e->type;
 677                 e++;
 678             }
 679             if (e->type != 0) { /* is there an offset? */
 680                 if (e->type <= EXPR_REG_END) {  /* in fact, is there an error? */
 681                     error(ERR_NONFATAL,
 682                           "beroset-p-603-invalid effective address");
 683                     result->opcode = -1;
 684                     return result;
 685                 } else {
 686                     if (e->type == EXPR_UNKNOWN) {
 687                         o = 0;  /* doesn't matter what */
 688                         result->oprs[operand].wrt = NO_SEG;     /* nor this */
 689                         result->oprs[operand].segment = NO_SEG; /* or this */
 690                         while (e->type)
 691                             e++;        /* go to the end of the line */
 692                     } else {
 693                         if (e->type == EXPR_SIMPLE) {
 694                             o = e->value;
 695                             e++;
 696                         }
 697                         if (e->type == EXPR_WRT) {
 698                             result->oprs[operand].wrt = e->value;
 699                             e++;
 700                         } else
 701                             result->oprs[operand].wrt = NO_SEG;
 702                         /*
 703                          * Look for a segment base type.
 704                          */
 705                         if (e->type && e->type < EXPR_SEGBASE) {
 706                             error(ERR_NONFATAL,
 707                                   "beroset-p-630-invalid effective address");
 708                             result->opcode = -1;
 709                             return result;
 710                         }
 711                         while (e->type && e->value == 0)
 712                             e++;
 713                         if (e->type && e->value != 1) {
 714                             error(ERR_NONFATAL,
 715                                   "beroset-p-637-invalid effective address");
 716                             result->opcode = -1;
 717                             return result;
 718                         }
 719                         if (e->type) {
 720                             result->oprs[operand].segment =
 721                                 e->type - EXPR_SEGBASE;
 722                             e++;
 723                         } else
 724                             result->oprs[operand].segment = NO_SEG;
 725                         while (e->type && e->value == 0)
 726                             e++;
 727                         if (e->type) {
 728                             error(ERR_NONFATAL,
 729                                   "beroset-p-650-invalid effective address");
 730                             result->opcode = -1;
 731                             return result;
 732                         }
 733                     }
 734                 }
 735             } else {
 736                 o = 0;
 737                 result->oprs[operand].wrt = NO_SEG;
 738                 result->oprs[operand].segment = NO_SEG;
 739             }
 740
 741             if (e->type != 0) { /* there'd better be nothing left! */
 742                 error(ERR_NONFATAL,
 743                       "beroset-p-663-invalid effective address");
 744                 result->opcode = -1;
 745                 return result;
 746             }
 747
 748             /* It is memory, but it can match any r/m operand */
 749             result->oprs[operand].type |= MEMORY_ANY;
 750
 751             if (b == -1 && (i == -1 || s == 0)) {
 752                 int is_rel = globalbits == 64 &&
 753                     !(result->oprs[operand].eaflags & EAF_ABS) &&
 754                     ((globalrel &&
 755                       !(result->oprs[operand].eaflags & EAF_FSGS)) ||
 756                      (result->oprs[operand].eaflags & EAF_REL));
 757
 758                 result->oprs[operand].type |= is_rel ? IP_REL : MEM_OFFS;
 759             }
 760             result->oprs[operand].basereg = b;
 761             result->oprs[operand].indexreg = i;
 762             result->oprs[operand].scale = s;
 763             result->oprs[operand].offset = o;
 764         } else {                /* it's not a memory reference */
 765
 766             if (is_just_unknown(value)) {       /* it's immediate but unknown */
 767                 result->oprs[operand].type |= IMMEDIATE;
 768                 result->oprs[operand].offset = 0;       /* don't care */
 769                 result->oprs[operand].segment = NO_SEG; /* don't care again */
 770                 result->oprs[operand].wrt = NO_SEG;     /* still don't care */
 771             } else if (is_reloc(value)) {       /* it's immediate */
 772                 result->oprs[operand].type |= IMMEDIATE;
 773                 result->oprs[operand].offset = reloc_value(value);
 774                 result->oprs[operand].segment = reloc_seg(value);
 775                 result->oprs[operand].wrt = reloc_wrt(value);
 776                 if (is_simple(value)) {
 777                     if (reloc_value(value) == 1)
 778                         result->oprs[operand].type |= UNITY;
 779                     if (optimizing >= 0 &&
 780                         !(result->oprs[operand].type & STRICT)) {
 781                         if (reloc_value(value) >= -128 &&
 782                             reloc_value(value) <= 127)
 783                             result->oprs[operand].type |= SBYTE;
 784                     }
 785                 }
 786             } else {            /* it's a register */
 787
 788                 if (value->type >= EXPR_SIMPLE || value->value != 1) {
 789                     error(ERR_NONFATAL, "invalid operand type");
 790                     result->opcode = -1;
 791                     return result;
 792                 }
 793
 794                 /*
 795                  * check that its only 1 register, not an expression...
 796                  */
 797                 for (i = 1; value[i].type; i++)
 798                     if (value[i].value) {
 799                         error(ERR_NONFATAL, "invalid operand type");
 800                         result->opcode = -1;
 801                         return result;
 802                     }
 803
 804                 /* clear overrides, except TO which applies to FPU regs */
 805                 if (result->oprs[operand].type & ~TO) {
 806                     /*
 807                      * we want to produce a warning iff the specified size
 808                      * is different from the register size
 809                      */
 810                     i = result->oprs[operand].type & SIZE_MASK;
 811                 } else
 812                     i = 0;
 813
 814                 result->oprs[operand].type &= TO;
 815                 result->oprs[operand].type |= REGISTER;
 816                 result->oprs[operand].type |= reg_flags[value->type];
 817                 result->oprs[operand].basereg = value->type;
 818
 819                 if (i && (result->oprs[operand].type & SIZE_MASK) != i)
 820                     error(ERR_WARNING | ERR_PASS1,
 821                           "register size specification ignored");
 822             }
 823         }
 824     }
 825
 826     result->operands = operand; /* set operand count */
 827
 828 /* clear remaining operands */
 829 while (operand < MAX_OPERANDS)
 830     result->oprs[operand++].type = 0;
 831
 832     /*
 833      * Transform RESW, RESD, RESQ, REST, RESO into RESB.
 834      */
 835     switch (result->opcode) {
 836     case I_RESW:
 837         result->opcode = I_RESB;
 838         result->oprs[0].offset *= 2;
 839         break;
 840     case I_RESD:
 841         result->opcode = I_RESB;
 842         result->oprs[0].offset *= 4;
 843         break;
 844     case I_RESQ:
 845         result->opcode = I_RESB;
 846         result->oprs[0].offset *= 8;
 847         break;
 848     case I_REST:
 849         result->opcode = I_RESB;
 850         result->oprs[0].offset *= 10;
 851         break;
 852     case I_RESO:
 853         result->opcode = I_RESB;
 854         result->oprs[0].offset *= 16;
 855         break;
 856     default:
 857         break;
 858     }
 859
 860     return result;
 861 }
 862
 863 static int is_comma_next(void)
 864 {
 865     char *p;
 866     int i;
 867     struct tokenval tv;
 868
 869     p = stdscan_bufptr;
 870     i = stdscan(NULL, &tv);
 871     stdscan_bufptr = p;
 872     return (i == ',' || i == ';' || !i);
 873 }
 874
 875 void cleanup_insn(insn * i)
 876 {
 877     extop *e;
 878
 879     while (i->eops) {
 880         e = i->eops;
 881         i->eops = i->eops->next;
 882         nasm_free(e);
 883     }
 884 }