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     bool recover;
 178
 179 restart_parse:
 180     first = true;
 181     result->forw_ref = false;
 182     error = errfunc;
 183
 184     stdscan_reset();
 185     stdscan_bufptr = buffer;
 186     i = stdscan(NULL, &tokval);
 187
 188     result->label = NULL;       /* Assume no label */
 189     result->eops = NULL;        /* must do this, whatever happens */
 190     result->operands = 0;       /* must initialize this */
 191
 192     if (i == 0) {               /* blank line - ignore */
 193         result->opcode = -1;    /* and no instruction either */
 194         return result;
 195     }
 196     if (i != TOKEN_ID && i != TOKEN_INSN && i != TOKEN_PREFIX &&
 197         (i != TOKEN_REG || (REG_SREG & ~nasm_reg_flags[tokval.t_integer]))) {
 198         error(ERR_NONFATAL, "label or instruction expected"
 199               " at start of line");
 200         result->opcode = -1;
 201         return result;
 202     }
 203
 204     if (i == TOKEN_ID || (insn_is_label && i == TOKEN_INSN)) {
 205         /* there's a label here */
 206         first = false;
 207         result->label = tokval.t_charptr;
 208         i = stdscan(NULL, &tokval);
 209         if (i == ':') {         /* skip over the optional colon */
 210             i = stdscan(NULL, &tokval);
 211         } else if (i == 0) {
 212             error(ERR_WARNING | ERR_WARN_OL | ERR_PASS1,
 213                   "label alone on a line without a colon might be in error");
 214         }
 215         if (i != TOKEN_INSN || tokval.t_integer != I_EQU) {
 216             /*
 217              * FIXME: location->segment could be NO_SEG, in which case
 218              * it is possible we should be passing 'abs_seg'. Look into this.
 219              * Work out whether that is *really* what we should be doing.
 220              * Generally fix things. I think this is right as it is, but
 221              * am still not certain.
 222              */
 223             ldef(result->label, in_abs_seg ? abs_seg : location->segment,
 224                  location->offset, NULL, true, false, outfmt, errfunc);
 225         }
 226     }
 227
 228     if (i == 0) {
 229         result->opcode = -1;    /* this line contains just a label */
 230         return result;
 231     }
 232
 233     for (j = 0; j < MAXPREFIX; j++)
 234         result->prefixes[j] = P_none;
 235     result->times = 1L;
 236
 237     while (i == TOKEN_PREFIX ||
 238            (i == TOKEN_REG && !(REG_SREG & ~nasm_reg_flags[tokval.t_integer])))
 239     {
 240         first = false;
 241
 242         /*
 243          * Handle special case: the TIMES prefix.
 244          */
 245         if (i == TOKEN_PREFIX && tokval.t_integer == P_TIMES) {
 246             expr *value;
 247
 248             i = stdscan(NULL, &tokval);
 249             value =
 250                 evaluate(stdscan, NULL, &tokval, NULL, pass0, error, NULL);
 251             i = tokval.t_type;
 252             if (!value) {       /* but, error in evaluator */
 253                 result->opcode = -1;    /* unrecoverable parse error: */
 254                 return result;  /* ignore this instruction */
 255             }
 256             if (!is_simple(value)) {
 257                 error(ERR_NONFATAL,
 258                       "non-constant argument supplied to TIMES");
 259                 result->times = 1L;
 260             } else {
 261                 result->times = value->value;
 262                 if (value->value < 0 && pass0 == 2) {
 263                     error(ERR_NONFATAL, "TIMES value %d is negative",
 264                           value->value);
 265                     result->times = 0;
 266                 }
 267             }
 268         } else {
 269             int slot = prefix_slot(tokval.t_integer);
 270             if (result->prefixes[slot]) {
 271                if (result->prefixes[slot] == tokval.t_integer)
 272                     error(ERR_WARNING,
 273                       "instruction has redundant prefixes");
 274                else
 275                     error(ERR_NONFATAL,
 276                       "instruction has conflicting prefixes");
 277             }
 278             result->prefixes[slot] = tokval.t_integer;
 279             i = stdscan(NULL, &tokval);
 280         }
 281     }
 282
 283     if (i != TOKEN_INSN) {
 284         int j;
 285         enum prefixes pfx;
 286
 287         for (j = 0; j < MAXPREFIX; j++)
 288             if ((pfx = result->prefixes[j]) != P_none)
 289                 break;
 290
 291         if (i == 0 && pfx != P_none) {
 292             /*
 293              * Instruction prefixes are present, but no actual
 294              * instruction. This is allowed: at this point we
 295              * invent a notional instruction of RESB 0.
 296              */
 297             result->opcode = I_RESB;
 298             result->operands = 1;
 299             result->oprs[0].type = IMMEDIATE;
 300             result->oprs[0].offset = 0L;
 301             result->oprs[0].segment = result->oprs[0].wrt = NO_SEG;
 302             return result;
 303         } else {
 304             error(ERR_NONFATAL, "parser: instruction expected");
 305             result->opcode = -1;
 306             return result;
 307         }
 308     }
 309
 310     result->opcode = tokval.t_integer;
 311     result->condition = tokval.t_inttwo;
 312
 313     /*
 314      * INCBIN cannot be satisfied with incorrectly
 315      * evaluated operands, since the correct values _must_ be known
 316      * on the first pass. Hence, even in pass one, we set the
 317      * `critical' flag on calling evaluate(), so that it will bomb
 318      * out on undefined symbols.
 319      */
 320     if (result->opcode == I_INCBIN) {
 321         critical = (pass0 < 2 ? 1 : 2);
 322
 323     } else
 324         critical = (pass == 2 ? 2 : 0);
 325
 326     if (result->opcode == I_DB || result->opcode == I_DW ||
 327         result->opcode == I_DD || result->opcode == I_DQ ||
 328         result->opcode == I_DT || result->opcode == I_DO ||
 329         result->opcode == I_DY || result->opcode == I_INCBIN) {
 330         extop *eop, **tail = &result->eops, **fixptr;
 331         int oper_num = 0;
 332         int32_t sign;
 333
 334         result->eops_float = false;
 335
 336         /*
 337          * Begin to read the DB/DW/DD/DQ/DT/DO/INCBIN operands.
 338          */
 339         while (1) {
 340             i = stdscan(NULL, &tokval);
 341             if (i == 0)
 342                 break;
 343             else if (first && i == ':') {
 344                 insn_is_label = true;
 345                 goto restart_parse;
 346             }
 347             first = false;
 348             fixptr = tail;
 349             eop = *tail = nasm_malloc(sizeof(extop));
 350             tail = &eop->next;
 351             eop->next = NULL;
 352             eop->type = EOT_NOTHING;
 353             oper_num++;
 354             sign = +1;
 355
 356             /* is_comma_next() here is to distinguish this from
 357                a string used as part of an expression... */
 358             if (i == TOKEN_STR && is_comma_next()) {
 359                 eop->type = EOT_DB_STRING;
 360                 eop->stringval = tokval.t_charptr;
 361                 eop->stringlen = tokval.t_inttwo;
 362                 i = stdscan(NULL, &tokval);     /* eat the comma */
 363             } else if (i == TOKEN_STRFUNC) {
 364                 bool parens = false;
 365                 const char *funcname = tokval.t_charptr;
 366                 enum strfunc func = tokval.t_integer;
 367                 i = stdscan(NULL, &tokval);
 368                 if (i == '(') {
 369                     parens = true;
 370                     i = stdscan(NULL, &tokval);
 371                 }
 372                 if (i != TOKEN_STR) {
 373                     error(ERR_NONFATAL,
 374                           "%s must be followed by a string constant",
 375                           funcname);
 376                         eop->type = EOT_NOTHING;
 377                 } else {
 378                     eop->type = EOT_DB_STRING_FREE;
 379                     eop->stringlen =
 380                         string_transform(tokval.t_charptr, tokval.t_inttwo,
 381                                          &eop->stringval, func);
 382                     if (eop->stringlen == (size_t)-1) {
 383                         error(ERR_NONFATAL, "invalid string for transform");
 384                         eop->type = EOT_NOTHING;
 385                     }
 386                 }
 387                 if (parens && i && i != ')') {
 388                     i = stdscan(NULL, &tokval);
 389                     if (i != ')') {
 390                         error(ERR_NONFATAL, "unterminated %s function",
 391                               funcname);
 392                     }
 393                 }
 394                 if (i && i != ',')
 395                     i = stdscan(NULL, &tokval);
 396             } else if (i == '-' || i == '+') {
 397                 char *save = stdscan_bufptr;
 398                 int token = i;
 399                 sign = (i == '-') ? -1 : 1;
 400                 i = stdscan(NULL, &tokval);
 401                 if (i != TOKEN_FLOAT) {
 402                     stdscan_bufptr = save;
 403                     i = tokval.t_type = token;
 404                     goto is_expression;
 405                 } else {
 406                     goto is_float;
 407                 }
 408             } else if (i == TOKEN_FLOAT) {
 409             is_float:
 410                 eop->type = EOT_DB_STRING;
 411                 result->eops_float = true;
 412                 switch (result->opcode) {
 413                 case I_DB:
 414                     eop->stringlen = 1;
 415                     break;
 416                 case I_DW:
 417                     eop->stringlen = 2;
 418                     break;
 419                 case I_DD:
 420                     eop->stringlen = 4;
 421                     break;
 422                 case I_DQ:
 423                     eop->stringlen = 8;
 424                     break;
 425                 case I_DT:
 426                     eop->stringlen = 10;
 427                     break;
 428                 case I_DO:
 429                     eop->stringlen = 16;
 430                     break;
 431                 case I_DY:
 432                     error(ERR_NONFATAL, "floating-point constant"
 433                           " encountered in DY instruction");
 434                     eop->stringlen = 0;
 435                     break;
 436                 default:
 437                     error(ERR_NONFATAL, "floating-point constant"
 438                           " encountered in unknown instruction");
 439                     /*
 440                      * fix suggested by Pedro Gimeno... original line
 441                      * was:
 442                      * eop->type = EOT_NOTHING;
 443                      */
 444                     eop->stringlen = 0;
 445                     break;
 446                 }
 447                 eop = nasm_realloc(eop, sizeof(extop) + eop->stringlen);
 448                 tail = &eop->next;
 449                 *fixptr = eop;
 450                 eop->stringval = (char *)eop + sizeof(extop);
 451                 if (!eop->stringlen ||
 452                     !float_const(tokval.t_charptr, sign,
 453                                  (uint8_t *)eop->stringval,
 454                                  eop->stringlen, error))
 455                     eop->type = EOT_NOTHING;
 456                 i = stdscan(NULL, &tokval); /* eat the comma */
 457             } else {
 458                 /* anything else, assume it is an expression */
 459                 expr *value;
 460
 461             is_expression:
 462                 value = evaluate(stdscan, NULL, &tokval, NULL,
 463                                  critical, error, NULL);
 464                 i = tokval.t_type;
 465                 if (!value) {   /* error in evaluator */
 466                     result->opcode = -1;        /* unrecoverable parse error: */
 467                     return result;      /* ignore this instruction */
 468                 }
 469                 if (is_unknown(value)) {
 470                     eop->type = EOT_DB_NUMBER;
 471                     eop->offset = 0;    /* doesn't matter what we put */
 472                     eop->segment = eop->wrt = NO_SEG;   /* likewise */
 473                 } else if (is_reloc(value)) {
 474                     eop->type = EOT_DB_NUMBER;
 475                     eop->offset = reloc_value(value);
 476                     eop->segment = reloc_seg(value);
 477                     eop->wrt = reloc_wrt(value);
 478                 } else {
 479                     error(ERR_NONFATAL,
 480                           "operand %d: expression is not simple"
 481                           " or relocatable", oper_num);
 482                 }
 483             }
 484
 485             /*
 486              * We're about to call stdscan(), which will eat the
 487              * comma that we're currently sitting on between
 488              * arguments. However, we'd better check first that it
 489              * _is_ a comma.
 490              */
 491             if (i == 0)         /* also could be EOL */
 492                 break;
 493             if (i != ',') {
 494                 error(ERR_NONFATAL, "comma expected after operand %d",
 495                       oper_num);
 496                 result->opcode = -1;    /* unrecoverable parse error: */
 497                 return result;  /* ignore this instruction */
 498             }
 499         }
 500
 501         if (result->opcode == I_INCBIN) {
 502             /*
 503              * Correct syntax for INCBIN is that there should be
 504              * one string operand, followed by one or two numeric
 505              * operands.
 506              */
 507             if (!result->eops || result->eops->type != EOT_DB_STRING)
 508                 error(ERR_NONFATAL, "`incbin' expects a file name");
 509             else if (result->eops->next &&
 510                      result->eops->next->type != EOT_DB_NUMBER)
 511                 error(ERR_NONFATAL, "`incbin': second parameter is",
 512                       " non-numeric");
 513             else if (result->eops->next && result->eops->next->next &&
 514                      result->eops->next->next->type != EOT_DB_NUMBER)
 515                 error(ERR_NONFATAL, "`incbin': third parameter is",
 516                       " non-numeric");
 517             else if (result->eops->next && result->eops->next->next &&
 518                      result->eops->next->next->next)
 519                 error(ERR_NONFATAL,
 520                       "`incbin': more than three parameters");
 521             else
 522                 return result;
 523             /*
 524              * If we reach here, one of the above errors happened.
 525              * Throw the instruction away.
 526              */
 527             result->opcode = -1;
 528             return result;
 529         } else /* DB ... */ if (oper_num == 0)
 530             error(ERR_WARNING | ERR_PASS1,
 531                   "no operand for data declaration");
 532         else
 533             result->operands = oper_num;
 534
 535         return result;
 536     }
 537
 538     /* right. Now we begin to parse the operands. There may be up to four
 539      * of these, separated by commas, and terminated by a zero token. */
 540
 541     for (operand = 0; operand < MAX_OPERANDS; operand++) {
 542         expr *value;            /* used most of the time */
 543         int mref;               /* is this going to be a memory ref? */
 544         int bracket;            /* is it a [] mref, or a & mref? */
 545         int setsize = 0;
 546
 547         result->oprs[operand].disp_size = 0;    /* have to zero this whatever */
 548         result->oprs[operand].eaflags = 0;      /* and this */
 549         result->oprs[operand].opflags = 0;
 550
 551         i = stdscan(NULL, &tokval);
 552         if (i == 0)
 553             break;              /* end of operands: get out of here */
 554         else if (first && i == ':') {
 555             insn_is_label = true;
 556             goto restart_parse;
 557         }
 558         first = false;
 559         result->oprs[operand].type = 0; /* so far, no override */
 560         while (i == TOKEN_SPECIAL) {    /* size specifiers */
 561             switch ((int)tokval.t_integer) {
 562             case S_BYTE:
 563                 if (!setsize)   /* we want to use only the first */
 564                     result->oprs[operand].type |= BITS8;
 565                 setsize = 1;
 566                 break;
 567             case S_WORD:
 568                 if (!setsize)
 569                     result->oprs[operand].type |= BITS16;
 570                 setsize = 1;
 571                 break;
 572             case S_DWORD:
 573             case S_LONG:
 574                 if (!setsize)
 575                     result->oprs[operand].type |= BITS32;
 576                 setsize = 1;
 577                 break;
 578             case S_QWORD:
 579                 if (!setsize)
 580                     result->oprs[operand].type |= BITS64;
 581                 setsize = 1;
 582                 break;
 583             case S_TWORD:
 584                 if (!setsize)
 585                     result->oprs[operand].type |= BITS80;
 586                 setsize = 1;
 587                 break;
 588             case S_OWORD:
 589                 if (!setsize)
 590                     result->oprs[operand].type |= BITS128;
 591                 setsize = 1;
 592                 break;
 593             case S_YWORD:
 594                 if (!setsize)
 595                     result->oprs[operand].type |= BITS256;
 596                 setsize = 1;
 597                 break;
 598             case S_TO:
 599                 result->oprs[operand].type |= TO;
 600                 break;
 601             case S_STRICT:
 602                 result->oprs[operand].type |= STRICT;
 603                 break;
 604             case S_FAR:
 605                 result->oprs[operand].type |= FAR;
 606                 break;
 607             case S_NEAR:
 608                 result->oprs[operand].type |= NEAR;
 609                 break;
 610             case S_SHORT:
 611                 result->oprs[operand].type |= SHORT;
 612                 break;
 613             default:
 614                 error(ERR_NONFATAL, "invalid operand size specification");
 615             }
 616             i = stdscan(NULL, &tokval);
 617         }
 618
 619         if (i == '[' || i == '&') {     /* memory reference */
 620             mref = true;
 621             bracket = (i == '[');
 622             i = stdscan(NULL, &tokval); /* then skip the colon */
 623             while (i == TOKEN_SPECIAL || i == TOKEN_PREFIX) {
 624                 process_size_override(result, operand);
 625                 i = stdscan(NULL, &tokval);
 626             }
 627         } else {                /* immediate operand, or register */
 628             mref = false;
 629             bracket = false;    /* placate optimisers */
 630         }
 631
 632         if ((result->oprs[operand].type & FAR) && !mref &&
 633             result->opcode != I_JMP && result->opcode != I_CALL) {
 634             error(ERR_NONFATAL, "invalid use of FAR operand specifier");
 635         }
 636
 637         value = evaluate(stdscan, NULL, &tokval,
 638                          &result->oprs[operand].opflags,
 639                          critical, error, &hints);
 640         i = tokval.t_type;
 641         if (result->oprs[operand].opflags & OPFLAG_FORWARD) {
 642             result->forw_ref = true;
 643         }
 644         if (!value) {           /* error in evaluator */
 645             result->opcode = -1;        /* unrecoverable parse error: */
 646             return result;      /* ignore this instruction */
 647         }
 648         if (i == ':' && mref) { /* it was seg:offset */
 649             /*
 650              * Process the segment override.
 651              */
 652             if (value[1].type != 0 || value->value != 1 ||
 653                 REG_SREG & ~nasm_reg_flags[value->type])
 654                 error(ERR_NONFATAL, "invalid segment override");
 655             else if (result->prefixes[PPS_SEG])
 656                 error(ERR_NONFATAL,
 657                       "instruction has conflicting segment overrides");
 658             else {
 659                 result->prefixes[PPS_SEG] = value->type;
 660                 if (!(REG_FSGS & ~nasm_reg_flags[value->type]))
 661                     result->oprs[operand].eaflags |= EAF_FSGS;
 662             }
 663
 664             i = stdscan(NULL, &tokval); /* then skip the colon */
 665             while (i == TOKEN_SPECIAL || i == TOKEN_PREFIX) {
 666                 process_size_override(result, operand);
 667                 i = stdscan(NULL, &tokval);
 668             }
 669             value = evaluate(stdscan, NULL, &tokval,
 670                              &result->oprs[operand].opflags,
 671                              critical, error, &hints);
 672             i = tokval.t_type;
 673             if (result->oprs[operand].opflags & OPFLAG_FORWARD) {
 674                 result->forw_ref = true;
 675             }
 676             /* and get the offset */
 677             if (!value) {       /* but, error in evaluator */
 678                 result->opcode = -1;    /* unrecoverable parse error: */
 679                 return result;  /* ignore this instruction */
 680             }
 681         }
 682
 683         recover = false;
 684         if (mref && bracket) {  /* find ] at the end */
 685             if (i != ']') {
 686                 error(ERR_NONFATAL, "parser: expecting ]");
 687                 recover = true;
 688             } else {            /* we got the required ] */
 689                 i = stdscan(NULL, &tokval);
 690                 if (i != 0 && i != ',') {
 691                     error(ERR_NONFATAL, "comma or end of line expected");
 692                     recover = true;
 693                 }
 694             }
 695         } else {                /* immediate operand */
 696             if (i != 0 && i != ',' && i != ':') {
 697                 error(ERR_NONFATAL, "comma, colon or end of line expected");
 698                 recover = true;
 699             } else if (i == ':') {
 700                 result->oprs[operand].type |= COLON;
 701             }
 702         }
 703         if (recover) {
 704             do {                /* error recovery */
 705                 i = stdscan(NULL, &tokval);
 706             } while (i != 0 && i != ',');
 707         }
 708
 709         /* now convert the exprs returned from evaluate() into operand
 710          * descriptions... */
 711
 712         if (mref) {             /* it's a memory reference */
 713             expr *e = value;
 714             int b, i, s;        /* basereg, indexreg, scale */
 715             int64_t o;             /* offset */
 716
 717             b = i = -1, o = s = 0;
 718             result->oprs[operand].hintbase = hints.base;
 719             result->oprs[operand].hinttype = hints.type;
 720
 721             if (e->type && e->type <= EXPR_REG_END) {   /* this bit's a register */
 722                 if (e->value == 1)      /* in fact it can be basereg */
 723                     b = e->type;
 724                 else            /* no, it has to be indexreg */
 725                     i = e->type, s = e->value;
 726                 e++;
 727             }
 728             if (e->type && e->type <= EXPR_REG_END) {   /* it's a 2nd register */
 729                 if (b != -1)    /* If the first was the base, ... */
 730                     i = e->type, s = e->value;  /* second has to be indexreg */
 731
 732                 else if (e->value != 1) {       /* If both want to be index */
 733                     error(ERR_NONFATAL,
 734                           "beroset-p-592-invalid effective address");
 735                     result->opcode = -1;
 736                     return result;
 737                 } else
 738                     b = e->type;
 739                 e++;
 740             }
 741             if (e->type != 0) { /* is there an offset? */
 742                 if (e->type <= EXPR_REG_END) {  /* in fact, is there an error? */
 743                     error(ERR_NONFATAL,
 744                           "beroset-p-603-invalid effective address");
 745                     result->opcode = -1;
 746                     return result;
 747                 } else {
 748                     if (e->type == EXPR_UNKNOWN) {
 749                         result->oprs[operand].opflags |= OPFLAG_UNKNOWN;
 750                         o = 0;  /* doesn't matter what */
 751                         result->oprs[operand].wrt = NO_SEG;     /* nor this */
 752                         result->oprs[operand].segment = NO_SEG; /* or this */
 753                         while (e->type)
 754                             e++;        /* go to the end of the line */
 755                     } else {
 756                         if (e->type == EXPR_SIMPLE) {
 757                             o = e->value;
 758                             e++;
 759                         }
 760                         if (e->type == EXPR_WRT) {
 761                             result->oprs[operand].wrt = e->value;
 762                             e++;
 763                         } else
 764                             result->oprs[operand].wrt = NO_SEG;
 765                         /*
 766                          * Look for a segment base type.
 767                          */
 768                         if (e->type && e->type < EXPR_SEGBASE) {
 769                             error(ERR_NONFATAL,
 770                                   "beroset-p-630-invalid effective address");
 771                             result->opcode = -1;
 772                             return result;
 773                         }
 774                         while (e->type && e->value == 0)
 775                             e++;
 776                         if (e->type && e->value != 1) {
 777                             error(ERR_NONFATAL,
 778                                   "beroset-p-637-invalid effective address");
 779                             result->opcode = -1;
 780                             return result;
 781                         }
 782                         if (e->type) {
 783                             result->oprs[operand].segment =
 784                                 e->type - EXPR_SEGBASE;
 785                             e++;
 786                         } else
 787                             result->oprs[operand].segment = NO_SEG;
 788                         while (e->type && e->value == 0)
 789                             e++;
 790                         if (e->type) {
 791                             error(ERR_NONFATAL,
 792                                   "beroset-p-650-invalid effective address");
 793                             result->opcode = -1;
 794                             return result;
 795                         }
 796                     }
 797                 }
 798             } else {
 799                 o = 0;
 800                 result->oprs[operand].wrt = NO_SEG;
 801                 result->oprs[operand].segment = NO_SEG;
 802             }
 803
 804             if (e->type != 0) { /* there'd better be nothing left! */
 805                 error(ERR_NONFATAL,
 806                       "beroset-p-663-invalid effective address");
 807                 result->opcode = -1;
 808                 return result;
 809             }
 810
 811             /* It is memory, but it can match any r/m operand */
 812             result->oprs[operand].type |= MEMORY_ANY;
 813
 814             if (b == -1 && (i == -1 || s == 0)) {
 815                 int is_rel = globalbits == 64 &&
 816                     !(result->oprs[operand].eaflags & EAF_ABS) &&
 817                     ((globalrel &&
 818                       !(result->oprs[operand].eaflags & EAF_FSGS)) ||
 819                      (result->oprs[operand].eaflags & EAF_REL));
 820
 821                 result->oprs[operand].type |= is_rel ? IP_REL : MEM_OFFS;
 822             }
 823             result->oprs[operand].basereg = b;
 824             result->oprs[operand].indexreg = i;
 825             result->oprs[operand].scale = s;
 826             result->oprs[operand].offset = o;
 827         } else {                /* it's not a memory reference */
 828             if (is_just_unknown(value)) {       /* it's immediate but unknown */
 829                 result->oprs[operand].type |= IMMEDIATE;
 830                 result->oprs[operand].opflags |= OPFLAG_UNKNOWN;
 831                 result->oprs[operand].offset = 0;       /* don't care */
 832                 result->oprs[operand].segment = NO_SEG; /* don't care again */
 833                 result->oprs[operand].wrt = NO_SEG;     /* still don't care */
 834
 835                 if(optimizing >= 0 && !(result->oprs[operand].type & STRICT))
 836                 {
 837                     /* Be optimistic */
 838                     result->oprs[operand].type |= SBYTE16 | SBYTE32 | SBYTE64;
 839                 }
 840             } else if (is_reloc(value)) {       /* it's immediate */
 841                 result->oprs[operand].type |= IMMEDIATE;
 842                 result->oprs[operand].offset = reloc_value(value);
 843                 result->oprs[operand].segment = reloc_seg(value);
 844                 result->oprs[operand].wrt = reloc_wrt(value);
 845                 if (is_simple(value)) {
 846                     if (reloc_value(value) == 1)
 847                         result->oprs[operand].type |= UNITY;
 848                     if (optimizing >= 0 &&
 849                         !(result->oprs[operand].type & STRICT)) {
 850                         int64_t v64 = reloc_value(value);
 851                         int32_t v32 = (int32_t)v64;
 852                         int16_t v16 = (int16_t)v32;
 853
 854                         if (v64 >= -128 && v64 <= 127)
 855                             result->oprs[operand].type |= SBYTE64;
 856                         if (v32 >= -128 && v32 <= 127)
 857                             result->oprs[operand].type |= SBYTE32;
 858                         if (v16 >= -128 && v16 <= 127)
 859                             result->oprs[operand].type |= SBYTE16;
 860                     }
 861                 }
 862             } else {            /* it's a register */
 863                 unsigned int rs;
 864
 865                 if (value->type >= EXPR_SIMPLE || value->value != 1) {
 866                     error(ERR_NONFATAL, "invalid operand type");
 867                     result->opcode = -1;
 868                     return result;
 869                 }
 870
 871                 /*
 872                  * check that its only 1 register, not an expression...
 873                  */
 874                 for (i = 1; value[i].type; i++)
 875                     if (value[i].value) {
 876                         error(ERR_NONFATAL, "invalid operand type");
 877                         result->opcode = -1;
 878                         return result;
 879                     }
 880
 881                 /* clear overrides, except TO which applies to FPU regs */
 882                 if (result->oprs[operand].type & ~TO) {
 883                     /*
 884                      * we want to produce a warning iff the specified size
 885                      * is different from the register size
 886                      */
 887                     rs = result->oprs[operand].type & SIZE_MASK;
 888                 } else
 889                     rs = 0;
 890
 891                 result->oprs[operand].type &= TO;
 892                 result->oprs[operand].type |= REGISTER;
 893                 result->oprs[operand].type |= nasm_reg_flags[value->type];
 894                 result->oprs[operand].basereg = value->type;
 895
 896                 if (rs && (result->oprs[operand].type & SIZE_MASK) != rs)
 897                     error(ERR_WARNING | ERR_PASS1,
 898                           "register size specification ignored");
 899             }
 900         }
 901     }
 902
 903     result->operands = operand; /* set operand count */
 904
 905 /* clear remaining operands */
 906 while (operand < MAX_OPERANDS)
 907     result->oprs[operand++].type = 0;
 908
 909     /*
 910      * Transform RESW, RESD, RESQ, REST, RESO, RESY into RESB.
 911      */
 912     switch (result->opcode) {
 913     case I_RESW:
 914         result->opcode = I_RESB;
 915         result->oprs[0].offset *= 2;
 916         break;
 917     case I_RESD:
 918         result->opcode = I_RESB;
 919         result->oprs[0].offset *= 4;
 920         break;
 921     case I_RESQ:
 922         result->opcode = I_RESB;
 923         result->oprs[0].offset *= 8;
 924         break;
 925     case I_REST:
 926         result->opcode = I_RESB;
 927         result->oprs[0].offset *= 10;
 928         break;
 929     case I_RESO:
 930         result->opcode = I_RESB;
 931         result->oprs[0].offset *= 16;
 932         break;
 933     case I_RESY:
 934         result->opcode = I_RESB;
 935         result->oprs[0].offset *= 32;
 936         break;
 937     default:
 938         break;
 939     }
 940
 941     return result;
 942 }
 943
 944 static int is_comma_next(void)
 945 {
 946     char *p;
 947     int i;
 948     struct tokenval tv;
 949
 950     p = stdscan_bufptr;
 951     i = stdscan(NULL, &tv);
 952     stdscan_bufptr = p;
 953     return (i == ',' || i == ';' || !i);
 954 }
 955
 956 void cleanup_insn(insn * i)
 957 {
 958     extop *e;
 959
 960     while ((e = i->eops)) {
 961         i->eops = e->next;
 962         if (e->type == EOT_DB_STRING_FREE)
 963             nasm_free(e->stringval);
 964         nasm_free(e);
 965     }
 966 }