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 license given in the file "LICENSE"
   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 #include "tables.h"
  27
  28 extern int in_abs_seg;          /* ABSOLUTE segment flag */
  29 extern int32_t abs_seg;            /* ABSOLUTE segment */
  30 extern int32_t abs_offset;         /* ABSOLUTE segment offset */
  31
  32 static int is_comma_next(void);
  33
  34 static int i;
  35 static struct tokenval tokval;
  36 static efunc error;
  37 static struct ofmt *outfmt;     /* Structure of addresses of output routines */
  38 static struct location *location;         /* Pointer to current line's segment,offset */
  39
  40 void parser_global_info(struct ofmt *output, struct location * locp)
  41 {
  42     outfmt = output;
  43     location = locp;
  44 }
  45
  46 static int prefix_slot(enum prefixes prefix)
  47 {
  48     switch (prefix) {
  49     case P_WAIT:
  50         return PPS_WAIT;
  51     case R_CS:
  52     case R_DS:
  53     case R_SS:
  54     case R_ES:
  55     case R_FS:
  56     case R_GS:
  57         return PPS_SEG;
  58     case P_LOCK:
  59     case P_REP:
  60     case P_REPE:
  61     case P_REPZ:
  62     case P_REPNE:
  63     case P_REPNZ:
  64         return PPS_LREP;
  65     case P_O16:
  66     case P_O32:
  67     case P_O64:
  68     case P_OSP:
  69         return PPS_OSIZE;
  70     case P_A16:
  71     case P_A32:
  72     case P_A64:
  73     case P_ASP:
  74         return PPS_ASIZE;
  75     default:
  76         error(ERR_PANIC, "Invalid value %d passed to prefix_slot()", prefix);
  77         return -1;
  78     }
  79 }
  80
  81 static void process_size_override(insn * result, int operand)
  82 {
  83     if (tasm_compatible_mode) {
  84         switch ((int)tokval.t_integer) {
  85             /* For TASM compatibility a size override inside the
  86              * brackets changes the size of the operand, not the
  87              * address type of the operand as it does in standard
  88              * NASM syntax. Hence:
  89              *
  90              *  mov     eax,[DWORD val]
  91              *
  92              * is valid syntax in TASM compatibility mode. Note that
  93              * you lose the ability to override the default address
  94              * type for the instruction, but we never use anything
  95              * but 32-bit flat model addressing in our code.
  96              */
  97         case S_BYTE:
  98             result->oprs[operand].type |= BITS8;
  99             break;
 100         case S_WORD:
 101             result->oprs[operand].type |= BITS16;
 102             break;
 103         case S_DWORD:
 104         case S_LONG:
 105             result->oprs[operand].type |= BITS32;
 106             break;
 107         case S_QWORD:
 108             result->oprs[operand].type |= BITS64;
 109             break;
 110         case S_TWORD:
 111             result->oprs[operand].type |= BITS80;
 112             break;
 113         case S_OWORD:
 114             result->oprs[operand].type |= BITS128;
 115             break;
 116         default:
 117             error(ERR_NONFATAL,
 118                   "invalid operand size specification");
 119             break;
 120         }
 121     } else {
 122         /* Standard NASM compatible syntax */
 123         switch ((int)tokval.t_integer) {
 124         case S_NOSPLIT:
 125             result->oprs[operand].eaflags |= EAF_TIMESTWO;
 126             break;
 127         case S_REL:
 128             result->oprs[operand].eaflags |= EAF_REL;
 129             break;
 130         case S_ABS:
 131             result->oprs[operand].eaflags |= EAF_ABS;
 132             break;
 133         case S_BYTE:
 134             result->oprs[operand].disp_size = 8;
 135             result->oprs[operand].eaflags |= EAF_BYTEOFFS;
 136             break;
 137         case P_A16:
 138         case P_A32:
 139         case P_A64:
 140             if (result->prefixes[PPS_ASIZE] &&
 141                 result->prefixes[PPS_ASIZE] != tokval.t_integer)
 142                 error(ERR_NONFATAL,
 143                       "conflicting address size specifications");
 144             else
 145                 result->prefixes[PPS_ASIZE] = tokval.t_integer;
 146             break;
 147         case S_WORD:
 148             result->oprs[operand].disp_size = 16;
 149             result->oprs[operand].eaflags |= EAF_WORDOFFS;
 150             break;
 151         case S_DWORD:
 152         case S_LONG:
 153             result->oprs[operand].disp_size = 32;
 154             result->oprs[operand].eaflags |= EAF_WORDOFFS;
 155             break;
 156         case S_QWORD:
 157             result->oprs[operand].disp_size = 64;
 158             result->oprs[operand].eaflags |= EAF_WORDOFFS;
 159             break;
 160         default:
 161             error(ERR_NONFATAL, "invalid size specification in"
 162                   " effective address");
 163             break;
 164         }
 165     }
 166 }
 167
 168 insn *parse_line(int pass, char *buffer, insn * result,
 169                  efunc errfunc, evalfunc evaluate, ldfunc ldef)
 170 {
 171     int operand;
 172     int critical;
 173     struct eval_hints hints;
 174     int j;
 175     bool first;
 176     bool insn_is_label = false;
 177
 178 restart_parse:
 179     first = true;
 180     result->forw_ref = false;
 181     error = errfunc;
 182
 183     stdscan_reset();
 184     stdscan_bufptr = buffer;
 185     i = stdscan(NULL, &tokval);
 186
 187     result->label = NULL;       /* Assume no label */
 188     result->eops = NULL;        /* must do this, whatever happens */
 189     result->operands = 0;       /* must initialize this */
 190
 191     if (i == 0) {               /* blank line - ignore */
 192         result->opcode = -1;    /* and no instruction either */
 193         return result;
 194     }
 195     if (i != TOKEN_ID && i != TOKEN_INSN && i != TOKEN_PREFIX &&
 196         (i != TOKEN_REG || (REG_SREG & ~nasm_reg_flags[tokval.t_integer]))) {
 197         error(ERR_NONFATAL, "label or instruction expected"
 198               " at start of line");
 199         result->opcode = -1;
 200         return result;
 201     }
 202
 203     if (i == TOKEN_ID || (insn_is_label && i == TOKEN_INSN)) {
 204         /* there's a label here */
 205         first = false;
 206         result->label = tokval.t_charptr;
 207         i = stdscan(NULL, &tokval);
 208         if (i == ':') {         /* skip over the optional colon */
 209             i = stdscan(NULL, &tokval);
 210         } else if (i == 0) {
 211             error(ERR_WARNING | ERR_WARN_OL | ERR_PASS1,
 212                   "label alone on a line without a colon might be in error");
 213         }
 214         if (i != TOKEN_INSN || tokval.t_integer != I_EQU) {
 215             /*
 216              * FIXME: location->segment could be NO_SEG, in which case
 217              * it is possible we should be passing 'abs_seg'. Look into this.
 218              * Work out whether that is *really* what we should be doing.
 219              * Generally fix things. I think this is right as it is, but
 220              * am still not certain.
 221              */
 222             ldef(result->label, in_abs_seg ? abs_seg : location->segment,
 223                  location->offset, NULL, true, false, outfmt, errfunc);
 224         }
 225     }
 226
 227     if (i == 0) {
 228         result->opcode = -1;    /* this line contains just a label */
 229         return result;
 230     }
 231
 232     for (j = 0; j < MAXPREFIX; j++)
 233         result->prefixes[j] = P_none;
 234     result->times = 1L;
 235
 236     while (i == TOKEN_PREFIX ||
 237            (i == TOKEN_REG && !(REG_SREG & ~nasm_reg_flags[tokval.t_integer])))
 238     {
 239         first = false;
 240
 241         /*
 242          * Handle special case: the TIMES prefix.
 243          */
 244         if (i == TOKEN_PREFIX && tokval.t_integer == P_TIMES) {
 245             expr *value;
 246
 247             i = stdscan(NULL, &tokval);
 248             value =
 249                 evaluate(stdscan, NULL, &tokval, NULL, pass0, error, NULL);
 250             i = tokval.t_type;
 251             if (!value) {       /* but, error in evaluator */
 252                 result->opcode = -1;    /* unrecoverable parse error: */
 253                 return result;  /* ignore this instruction */
 254             }
 255             if (!is_simple(value)) {
 256                 error(ERR_NONFATAL,
 257                       "non-constant argument supplied to TIMES");
 258                 result->times = 1L;
 259             } else {
 260                 result->times = value->value;
 261                 if (value->value < 0 && pass0 == 2) {
 262                     error(ERR_NONFATAL, "TIMES value %d is negative",
 263                           value->value);
 264                     result->times = 0;
 265                 }
 266             }
 267         } else {
 268             int slot = prefix_slot(tokval.t_integer);
 269             if (result->prefixes[slot]) {
 270                if (result->prefixes[slot] == tokval.t_integer)
 271                     error(ERR_WARNING,
 272                       "instruction has redundant prefixes");
 273                else
 274                     error(ERR_NONFATAL,
 275                       "instruction has conflicting prefixes");
 276             }
 277             result->prefixes[slot] = tokval.t_integer;
 278             i = stdscan(NULL, &tokval);
 279         }
 280     }
 281
 282     if (i != TOKEN_INSN) {
 283         int j;
 284         enum prefixes pfx;
 285
 286         for (j = 0; j < MAXPREFIX; j++)
 287             if ((pfx = result->prefixes[j]) != P_none)
 288                 break;
 289
 290         if (i == 0 && pfx != P_none) {
 291             /*
 292              * Instruction prefixes are present, but no actual
 293              * instruction. This is allowed: at this point we
 294              * invent a notional instruction of RESB 0.
 295              */
 296             result->opcode = I_RESB;
 297             result->operands = 1;
 298             result->oprs[0].type = IMMEDIATE;
 299             result->oprs[0].offset = 0L;
 300             result->oprs[0].segment = result->oprs[0].wrt = NO_SEG;
 301             return result;
 302         } else {
 303             error(ERR_NONFATAL, "parser: instruction expected");
 304             result->opcode = -1;
 305             return result;
 306         }
 307     }
 308
 309     result->opcode = tokval.t_integer;
 310     result->condition = tokval.t_inttwo;
 311
 312     /*
 313      * INCBIN cannot be satisfied with incorrectly
 314      * evaluated operands, since the correct values _must_ be known
 315      * on the first pass. Hence, even in pass one, we set the
 316      * `critical' flag on calling evaluate(), so that it will bomb
 317      * out on undefined symbols.
 318      */
 319     if (result->opcode == I_INCBIN) {
 320         critical = (pass0 < 2 ? 1 : 2);
 321
 322     } else
 323         critical = (pass == 2 ? 2 : 0);
 324
 325     if (result->opcode == I_DB || result->opcode == I_DW ||
 326         result->opcode == I_DD || result->opcode == I_DQ ||
 327         result->opcode == I_DT || result->opcode == I_DO ||
 328         result->opcode == I_DY || result->opcode == I_INCBIN) {
 329         extop *eop, **tail = &result->eops, **fixptr;
 330         int oper_num = 0;
 331         int32_t sign;
 332
 333         result->eops_float = false;
 334
 335         /*
 336          * Begin to read the DB/DW/DD/DQ/DT/DO/INCBIN operands.
 337          */
 338         while (1) {
 339             i = stdscan(NULL, &tokval);
 340             if (i == 0)
 341                 break;
 342             else if (first && i == ':') {
 343                 insn_is_label = true;
 344                 goto restart_parse;
 345             }
 346             first = false;
 347             fixptr = tail;
 348             eop = *tail = nasm_malloc(sizeof(extop));
 349             tail = &eop->next;
 350             eop->next = NULL;
 351             eop->type = EOT_NOTHING;
 352             oper_num++;
 353             sign = +1;
 354
 355             /* is_comma_next() here is to distinguish this from
 356                a string used as part of an expression... */
 357             if (i == TOKEN_STR && is_comma_next()) {
 358                 eop->type = EOT_DB_STRING;
 359                 eop->stringval = tokval.t_charptr;
 360                 eop->stringlen = tokval.t_inttwo;
 361                 i = stdscan(NULL, &tokval);     /* eat the comma */
 362             } else if (i == TOKEN_STRFUNC) {
 363                 bool parens = false;
 364                 const char *funcname = tokval.t_charptr;
 365                 enum strfunc func = tokval.t_integer;
 366                 i = stdscan(NULL, &tokval);
 367                 if (i == '(') {
 368                     parens = true;
 369                     i = stdscan(NULL, &tokval);
 370                 }
 371                 if (i != TOKEN_STR) {
 372                     error(ERR_NONFATAL,
 373                           "%s must be followed by a string constant",
 374                           funcname);
 375                         eop->type = EOT_NOTHING;
 376                 } else {
 377                     eop->type = EOT_DB_STRING_FREE;
 378                     eop->stringlen =
 379                         string_transform(tokval.t_charptr, tokval.t_inttwo,
 380                                          &eop->stringval, func);
 381                     if (eop->stringlen == (size_t)-1) {
 382                         error(ERR_NONFATAL, "invalid string for transform");
 383                         eop->type = EOT_NOTHING;
 384                     }
 385                 }
 386                 if (parens && i && i != ')') {
 387                     i = stdscan(NULL, &tokval);
 388                     if (i != ')') {
 389                         error(ERR_NONFATAL, "unterminated %s function",
 390                               funcname);
 391                     }
 392                 }
 393                 if (i && i != ',')
 394                     i = stdscan(NULL, &tokval);
 395             } else if (i == '-' || i == '+') {
 396                 char *save = stdscan_bufptr;
 397                 int token = i;
 398                 sign = (i == '-') ? -1 : 1;
 399                 i = stdscan(NULL, &tokval);
 400                 if (i != TOKEN_FLOAT) {
 401                     stdscan_bufptr = save;
 402                     i = tokval.t_type = token;
 403                     goto is_expression;
 404                 } else {
 405                     goto is_float;
 406                 }
 407             } else if (i == TOKEN_FLOAT) {
 408             is_float:
 409                 eop->type = EOT_DB_STRING;
 410                 result->eops_float = true;
 411                 switch (result->opcode) {
 412                 case I_DB:
 413                     eop->stringlen = 1;
 414                     break;
 415                 case I_DW:
 416                     eop->stringlen = 2;
 417                     break;
 418                 case I_DD:
 419                     eop->stringlen = 4;
 420                     break;
 421                 case I_DQ:
 422                     eop->stringlen = 8;
 423                     break;
 424                 case I_DT:
 425                     eop->stringlen = 10;
 426                     break;
 427                 case I_DO:
 428                     eop->stringlen = 16;
 429                     break;
 430                 case I_DY:
 431                     error(ERR_NONFATAL, "floating-point constant"
 432                           " encountered in DY instruction");
 433                     eop->stringlen = 0;
 434                     break;
 435                 default:
 436                     error(ERR_NONFATAL, "floating-point constant"
 437                           " encountered in unknown instruction");
 438                     /*
 439                      * fix suggested by Pedro Gimeno... original line
 440                      * was:
 441                      * eop->type = EOT_NOTHING;
 442                      */
 443                     eop->stringlen = 0;
 444                     break;
 445                 }
 446                 eop = nasm_realloc(eop, sizeof(extop) + eop->stringlen);
 447                 tail = &eop->next;
 448                 *fixptr = eop;
 449                 eop->stringval = (char *)eop + sizeof(extop);
 450                 if (!eop->stringlen ||
 451                     !float_const(tokval.t_charptr, sign,
 452                                  (uint8_t *)eop->stringval,
 453                                  eop->stringlen, error))
 454                     eop->type = EOT_NOTHING;
 455                 i = stdscan(NULL, &tokval); /* eat the comma */
 456             } else {
 457                 /* anything else, assume it is an expression */
 458                 expr *value;
 459
 460             is_expression:
 461                 value = evaluate(stdscan, NULL, &tokval, NULL,
 462                                  critical, error, NULL);
 463                 i = tokval.t_type;
 464                 if (!value) {   /* error in evaluator */
 465                     result->opcode = -1;        /* unrecoverable parse error: */
 466                     return result;      /* ignore this instruction */
 467                 }
 468                 if (is_unknown(value)) {
 469                     eop->type = EOT_DB_NUMBER;
 470                     eop->offset = 0;    /* doesn't matter what we put */
 471                     eop->segment = eop->wrt = NO_SEG;   /* likewise */
 472                 } else if (is_reloc(value)) {
 473                     eop->type = EOT_DB_NUMBER;
 474                     eop->offset = reloc_value(value);
 475                     eop->segment = reloc_seg(value);
 476                     eop->wrt = reloc_wrt(value);
 477                 } else {
 478                     error(ERR_NONFATAL,
 479                           "operand %d: expression is not simple"
 480                           " or relocatable", oper_num);
 481                 }
 482             }
 483
 484             /*
 485              * We're about to call stdscan(), which will eat the
 486              * comma that we're currently sitting on between
 487              * arguments. However, we'd better check first that it
 488              * _is_ a comma.
 489              */
 490             if (i == 0)         /* also could be EOL */
 491                 break;
 492             if (i != ',') {
 493                 error(ERR_NONFATAL, "comma expected after operand %d",
 494                       oper_num);
 495                 result->opcode = -1;    /* unrecoverable parse error: */
 496                 return result;  /* ignore this instruction */
 497             }
 498         }
 499
 500         if (result->opcode == I_INCBIN) {
 501             /*
 502              * Correct syntax for INCBIN is that there should be
 503              * one string operand, followed by one or two numeric
 504              * operands.
 505              */
 506             if (!result->eops || result->eops->type != EOT_DB_STRING)
 507                 error(ERR_NONFATAL, "`incbin' expects a file name");
 508             else if (result->eops->next &&
 509                      result->eops->next->type != EOT_DB_NUMBER)
 510                 error(ERR_NONFATAL, "`incbin': second parameter is",
 511                       " non-numeric");
 512             else if (result->eops->next && result->eops->next->next &&
 513                      result->eops->next->next->type != EOT_DB_NUMBER)
 514                 error(ERR_NONFATAL, "`incbin': third parameter is",
 515                       " non-numeric");
 516             else if (result->eops->next && result->eops->next->next &&
 517                      result->eops->next->next->next)
 518                 error(ERR_NONFATAL,
 519                       "`incbin': more than three parameters");
 520             else
 521                 return result;
 522             /*
 523              * If we reach here, one of the above errors happened.
 524              * Throw the instruction away.
 525              */
 526             result->opcode = -1;
 527             return result;
 528         } else /* DB ... */ if (oper_num == 0)
 529             error(ERR_WARNING | ERR_PASS1,
 530                   "no operand for data declaration");
 531         else
 532             result->operands = oper_num;
 533
 534         return result;
 535     }
 536
 537     /* right. Now we begin to parse the operands. There may be up to four
 538      * of these, separated by commas, and terminated by a zero token. */
 539
 540     for (operand = 0; operand < MAX_OPERANDS; operand++) {
 541         expr *value;            /* used most of the time */
 542         int mref;               /* is this going to be a memory ref? */
 543         int bracket;            /* is it a [] mref, or a & mref? */
 544         int setsize = 0;
 545
 546         result->oprs[operand].disp_size = 0;    /* have to zero this whatever */
 547         result->oprs[operand].eaflags = 0;      /* and this */
 548         result->oprs[operand].opflags = 0;
 549
 550         i = stdscan(NULL, &tokval);
 551         if (i == 0)
 552             break;              /* end of operands: get out of here */
 553         else if (first && i == ':') {
 554             insn_is_label = true;
 555             goto restart_parse;
 556         }
 557         first = false;
 558         result->oprs[operand].type = 0; /* so far, no override */
 559         while (i == TOKEN_SPECIAL) {    /* size specifiers */
 560             switch ((int)tokval.t_integer) {
 561             case S_BYTE:
 562                 if (!setsize)   /* we want to use only the first */
 563                     result->oprs[operand].type |= BITS8;
 564                 setsize = 1;
 565                 break;
 566             case S_WORD:
 567                 if (!setsize)
 568                     result->oprs[operand].type |= BITS16;
 569                 setsize = 1;
 570                 break;
 571             case S_DWORD:
 572             case S_LONG:
 573                 if (!setsize)
 574                     result->oprs[operand].type |= BITS32;
 575                 setsize = 1;
 576                 break;
 577             case S_QWORD:
 578                 if (!setsize)
 579                     result->oprs[operand].type |= BITS64;
 580                 setsize = 1;
 581                 break;
 582             case S_TWORD:
 583                 if (!setsize)
 584                     result->oprs[operand].type |= BITS80;
 585                 setsize = 1;
 586                 break;
 587             case S_OWORD:
 588                 if (!setsize)
 589                     result->oprs[operand].type |= BITS128;
 590                 setsize = 1;
 591                 break;
 592             case S_YWORD:
 593                 if (!setsize)
 594                     result->oprs[operand].type |= BITS256;
 595                 setsize = 1;
 596                 break;
 597             case S_TO:
 598                 result->oprs[operand].type |= TO;
 599                 break;
 600             case S_STRICT:
 601                 result->oprs[operand].type |= STRICT;
 602                 break;
 603             case S_FAR:
 604                 result->oprs[operand].type |= FAR;
 605                 break;
 606             case S_NEAR:
 607                 result->oprs[operand].type |= NEAR;
 608                 break;
 609             case S_SHORT:
 610                 result->oprs[operand].type |= SHORT;
 611                 break;
 612             default:
 613                 error(ERR_NONFATAL, "invalid operand size specification");
 614             }
 615             i = stdscan(NULL, &tokval);
 616         }
 617
 618         if (i == '[' || i == '&') {     /* memory reference */
 619             mref = true;
 620             bracket = (i == '[');
 621             i = stdscan(NULL, &tokval); /* then skip the colon */
 622             while (i == TOKEN_SPECIAL || i == TOKEN_PREFIX) {
 623                 process_size_override(result, operand);
 624                 i = stdscan(NULL, &tokval);
 625             }
 626         } else {                /* immediate operand, or register */
 627             mref = false;
 628             bracket = false;    /* placate optimisers */
 629         }
 630
 631         if ((result->oprs[operand].type & FAR) && !mref &&
 632             result->opcode != I_JMP && result->opcode != I_CALL) {
 633             error(ERR_NONFATAL, "invalid use of FAR operand specifier");
 634         }
 635
 636         value = evaluate(stdscan, NULL, &tokval,
 637                          &result->oprs[operand].opflags,
 638                          critical, error, &hints);
 639         i = tokval.t_type;
 640         if (result->oprs[operand].opflags & OPFLAG_FORWARD) {
 641             result->forw_ref = true;
 642         }
 643         if (!value) {           /* error in evaluator */
 644             result->opcode = -1;        /* unrecoverable parse error: */
 645             return result;      /* ignore this instruction */
 646         }
 647         if (i == ':' && mref) { /* it was seg:offset */
 648             /*
 649              * Process the segment override.
 650              */
 651             if (value[1].type != 0 || value->value != 1 ||
 652                 REG_SREG & ~nasm_reg_flags[value->type])
 653                 error(ERR_NONFATAL, "invalid segment override");
 654             else if (result->prefixes[PPS_SEG])
 655                 error(ERR_NONFATAL,
 656                       "instruction has conflicting segment overrides");
 657             else {
 658                 result->prefixes[PPS_SEG] = value->type;
 659                 if (!(REG_FSGS & ~nasm_reg_flags[value->type]))
 660                     result->oprs[operand].eaflags |= EAF_FSGS;
 661             }
 662
 663             i = stdscan(NULL, &tokval); /* then skip the colon */
 664             while (i == TOKEN_SPECIAL || i == TOKEN_PREFIX) {
 665                 process_size_override(result, operand);
 666                 i = stdscan(NULL, &tokval);
 667             }
 668             value = evaluate(stdscan, NULL, &tokval,
 669                              &result->oprs[operand].opflags,
 670                              critical, error, &hints);
 671             i = tokval.t_type;
 672             if (result->oprs[operand].opflags & OPFLAG_FORWARD) {
 673                 result->forw_ref = true;
 674             }
 675             /* and get the offset */
 676             if (!value) {       /* but, error in evaluator */
 677                 result->opcode = -1;    /* unrecoverable parse error: */
 678                 return result;  /* ignore this instruction */
 679             }
 680         }
 681         if (mref && bracket) {  /* find ] at the end */
 682             if (i != ']') {
 683                 error(ERR_NONFATAL, "parser: expecting ]");
 684                 do {            /* error recovery again */
 685                     i = stdscan(NULL, &tokval);
 686                 } while (i != 0 && i != ',');
 687             } else              /* we got the required ] */
 688                 i = stdscan(NULL, &tokval);
 689         } else {                /* immediate operand */
 690             if (i != 0 && i != ',' && i != ':') {
 691                 error(ERR_NONFATAL, "comma or end of line expected");
 692                 do {            /* error recovery */
 693                     i = stdscan(NULL, &tokval);
 694                 } while (i != 0 && i != ',');
 695             } else if (i == ':') {
 696                 result->oprs[operand].type |= COLON;
 697             }
 698         }
 699
 700         /* now convert the exprs returned from evaluate() into operand
 701          * descriptions... */
 702
 703         if (mref) {             /* it's a memory reference */
 704             expr *e = value;
 705             int b, i, s;        /* basereg, indexreg, scale */
 706             int64_t o;             /* offset */
 707
 708             b = i = -1, o = s = 0;
 709             result->oprs[operand].hintbase = hints.base;
 710             result->oprs[operand].hinttype = hints.type;
 711
 712             if (e->type && e->type <= EXPR_REG_END) {   /* this bit's a register */
 713                 if (e->value == 1)      /* in fact it can be basereg */
 714                     b = e->type;
 715                 else            /* no, it has to be indexreg */
 716                     i = e->type, s = e->value;
 717                 e++;
 718             }
 719             if (e->type && e->type <= EXPR_REG_END) {   /* it's a 2nd register */
 720                 if (b != -1)    /* If the first was the base, ... */
 721                     i = e->type, s = e->value;  /* second has to be indexreg */
 722
 723                 else if (e->value != 1) {       /* If both want to be index */
 724                     error(ERR_NONFATAL,
 725                           "beroset-p-592-invalid effective address");
 726                     result->opcode = -1;
 727                     return result;
 728                 } else
 729                     b = e->type;
 730                 e++;
 731             }
 732             if (e->type != 0) { /* is there an offset? */
 733                 if (e->type <= EXPR_REG_END) {  /* in fact, is there an error? */
 734                     error(ERR_NONFATAL,
 735                           "beroset-p-603-invalid effective address");
 736                     result->opcode = -1;
 737                     return result;
 738                 } else {
 739                     if (e->type == EXPR_UNKNOWN) {
 740                         o = 0;  /* doesn't matter what */
 741                         result->oprs[operand].wrt = NO_SEG;     /* nor this */
 742                         result->oprs[operand].segment = NO_SEG; /* or this */
 743                         while (e->type)
 744                             e++;        /* go to the end of the line */
 745                     } else {
 746                         if (e->type == EXPR_SIMPLE) {
 747                             o = e->value;
 748                             e++;
 749                         }
 750                         if (e->type == EXPR_WRT) {
 751                             result->oprs[operand].wrt = e->value;
 752                             e++;
 753                         } else
 754                             result->oprs[operand].wrt = NO_SEG;
 755                         /*
 756                          * Look for a segment base type.
 757                          */
 758                         if (e->type && e->type < EXPR_SEGBASE) {
 759                             error(ERR_NONFATAL,
 760                                   "beroset-p-630-invalid effective address");
 761                             result->opcode = -1;
 762                             return result;
 763                         }
 764                         while (e->type && e->value == 0)
 765                             e++;
 766                         if (e->type && e->value != 1) {
 767                             error(ERR_NONFATAL,
 768                                   "beroset-p-637-invalid effective address");
 769                             result->opcode = -1;
 770                             return result;
 771                         }
 772                         if (e->type) {
 773                             result->oprs[operand].segment =
 774                                 e->type - EXPR_SEGBASE;
 775                             e++;
 776                         } else
 777                             result->oprs[operand].segment = NO_SEG;
 778                         while (e->type && e->value == 0)
 779                             e++;
 780                         if (e->type) {
 781                             error(ERR_NONFATAL,
 782                                   "beroset-p-650-invalid effective address");
 783                             result->opcode = -1;
 784                             return result;
 785                         }
 786                     }
 787                 }
 788             } else {
 789                 o = 0;
 790                 result->oprs[operand].wrt = NO_SEG;
 791                 result->oprs[operand].segment = NO_SEG;
 792             }
 793
 794             if (e->type != 0) { /* there'd better be nothing left! */
 795                 error(ERR_NONFATAL,
 796                       "beroset-p-663-invalid effective address");
 797                 result->opcode = -1;
 798                 return result;
 799             }
 800
 801             /* It is memory, but it can match any r/m operand */
 802             result->oprs[operand].type |= MEMORY_ANY;
 803
 804             if (b == -1 && (i == -1 || s == 0)) {
 805                 int is_rel = globalbits == 64 &&
 806                     !(result->oprs[operand].eaflags & EAF_ABS) &&
 807                     ((globalrel &&
 808                       !(result->oprs[operand].eaflags & EAF_FSGS)) ||
 809                      (result->oprs[operand].eaflags & EAF_REL));
 810
 811                 result->oprs[operand].type |= is_rel ? IP_REL : MEM_OFFS;
 812             }
 813             result->oprs[operand].basereg = b;
 814             result->oprs[operand].indexreg = i;
 815             result->oprs[operand].scale = s;
 816             result->oprs[operand].offset = o;
 817         } else {                /* it's not a memory reference */
 818
 819             if (is_just_unknown(value)) {       /* it's immediate but unknown */
 820                 result->oprs[operand].type |= IMMEDIATE;
 821                 result->oprs[operand].offset = 0;       /* don't care */
 822                 result->oprs[operand].segment = NO_SEG; /* don't care again */
 823                 result->oprs[operand].wrt = NO_SEG;     /* still don't care */
 824             } else if (is_reloc(value)) {       /* it's immediate */
 825                 result->oprs[operand].type |= IMMEDIATE;
 826                 result->oprs[operand].offset = reloc_value(value);
 827                 result->oprs[operand].segment = reloc_seg(value);
 828                 result->oprs[operand].wrt = reloc_wrt(value);
 829                 if (is_simple(value)) {
 830                     if (reloc_value(value) == 1)
 831                         result->oprs[operand].type |= UNITY;
 832                     if (optimizing >= 0 &&
 833                         !(result->oprs[operand].type & STRICT)) {
 834                         int64_t v64 = reloc_value(value);
 835                         int32_t v32 = (int32_t)v64;
 836                         int16_t v16 = (int16_t)v32;
 837
 838                         if (v64 >= -128 && v64 <= 127)
 839                             result->oprs[operand].type |= SBYTE64;
 840                         if (v32 >= -128 && v32 <= 127)
 841                             result->oprs[operand].type |= SBYTE32;
 842                         if (v16 >= -128 && v16 <= 127)
 843                             result->oprs[operand].type |= SBYTE16;
 844                     }
 845                 }
 846             } else {            /* it's a register */
 847                 unsigned int rs;
 848
 849                 if (value->type >= EXPR_SIMPLE || value->value != 1) {
 850                     error(ERR_NONFATAL, "invalid operand type");
 851                     result->opcode = -1;
 852                     return result;
 853                 }
 854
 855                 /*
 856                  * check that its only 1 register, not an expression...
 857                  */
 858                 for (i = 1; value[i].type; i++)
 859                     if (value[i].value) {
 860                         error(ERR_NONFATAL, "invalid operand type");
 861                         result->opcode = -1;
 862                         return result;
 863                     }
 864
 865                 /* clear overrides, except TO which applies to FPU regs */
 866                 if (result->oprs[operand].type & ~TO) {
 867                     /*
 868                      * we want to produce a warning iff the specified size
 869                      * is different from the register size
 870                      */
 871                     rs = result->oprs[operand].type & SIZE_MASK;
 872                 } else
 873                     rs = 0;
 874
 875                 result->oprs[operand].type &= TO;
 876                 result->oprs[operand].type |= REGISTER;
 877                 result->oprs[operand].type |= nasm_reg_flags[value->type];
 878                 result->oprs[operand].basereg = value->type;
 879
 880                 if (rs && (result->oprs[operand].type & SIZE_MASK) != rs)
 881                     error(ERR_WARNING | ERR_PASS1,
 882                           "register size specification ignored");
 883             }
 884         }
 885     }
 886
 887     result->operands = operand; /* set operand count */
 888
 889 /* clear remaining operands */
 890 while (operand < MAX_OPERANDS)
 891     result->oprs[operand++].type = 0;
 892
 893     /*
 894      * Transform RESW, RESD, RESQ, REST, RESO, RESY into RESB.
 895      */
 896     switch (result->opcode) {
 897     case I_RESW:
 898         result->opcode = I_RESB;
 899         result->oprs[0].offset *= 2;
 900         break;
 901     case I_RESD:
 902         result->opcode = I_RESB;
 903         result->oprs[0].offset *= 4;
 904         break;
 905     case I_RESQ:
 906         result->opcode = I_RESB;
 907         result->oprs[0].offset *= 8;
 908         break;
 909     case I_REST:
 910         result->opcode = I_RESB;
 911         result->oprs[0].offset *= 10;
 912         break;
 913     case I_RESO:
 914         result->opcode = I_RESB;
 915         result->oprs[0].offset *= 16;
 916         break;
 917     case I_RESY:
 918         result->opcode = I_RESB;
 919         result->oprs[0].offset *= 32;
 920         break;
 921     default:
 922         break;
 923     }
 924
 925     return result;
 926 }
 927
 928 static int is_comma_next(void)
 929 {
 930     char *p;
 931     int i;
 932     struct tokenval tv;
 933
 934     p = stdscan_bufptr;
 935     i = stdscan(NULL, &tv);
 936     stdscan_bufptr = p;
 937     return (i == ',' || i == ';' || !i);
 938 }
 939
 940 void cleanup_insn(insn * i)
 941 {
 942     extop *e;
 943
 944     while ((e = i->eops)) {
 945         i->eops = e->next;
 946         if (e->type == EOT_DB_STRING_FREE)
 947             nasm_free(e->stringval);
 948         nasm_free(e);
 949     }
 950 }