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