Shamusworld >> Repos - rmac/blob - procln.c

   1 //
   2 // RMAC - Reboot's Macro Assembler for the Atari Jaguar Console System
   3 // PROCLN.C - Line Processing
   4 // Copyright (C) 199x Landon Dyer, 2011 Reboot and Friends
   5 // RMAC derived from MADMAC v1.07 Written by Landon Dyer, 1986
   6 // Source Utilised with the Kind Permission of Landon Dyer
   7 //
   8
   9 #include "procln.h"
  10 #include "listing.h"
  11 #include "amode.h"
  12 #include "error.h"
  13 #include "sect.h"
  14 #include "expr.h"
  15 #include "mach.h"
  16 #include "direct.h"
  17 #include "macro.h"
  18 #include "symbol.h"
  19 #include "riscasm.h"
  20
  21 #define DEF_KW                                  // Declare keyword values
  22 #include "kwtab.h"                              // Incl generated keyword tables & defs
  23
  24 #define DEF_MN                                  // Incl 68k keyword definitions
  25 #define DECL_MN                                 // Incl 68k keyword state machine tables
  26 #include "mntab.h"
  27
  28 #define DEF_MR
  29 #define DECL_MR
  30 #include "risckw.h"
  31
  32
  33 IFENT * ifent;                                  // Current ifent
  34 static IFENT ifent0;                    // Root ifent
  35 static IFENT * f_ifent;                 // Freelist of ifents
  36 static int disabled;                    // Assembly conditionally disabled
  37 int just_bss;                                   // 1, ds.b in microprocessor mode
  38 VALUE pcloc;                                    // Value of "PC" at beginning of line
  39 IFENT * ifent;                                  // Current ifent
  40 SYM * lab_sym;                                  // Label on line (or NULL)
  41
  42 const char extra_stuff[] = "extra (unexpected) text found after addressing mode";
  43 const char comma_error[] = "missing comma";
  44 const char syntax_error[] = "syntax error";
  45 const char locgl_error[] = "cannot GLOBL local symbol";
  46 const char lab_ignored[] = "label ignored";
  47
  48 // Table to convert an addressing-mode number to a bitmask.
  49 LONG amsktab[0112] = {
  50         M_DREG, M_DREG, M_DREG, M_DREG,
  51         M_DREG, M_DREG, M_DREG, M_DREG,
  52
  53         M_AREG, M_AREG, M_AREG, M_AREG,
  54         M_AREG, M_AREG, M_AREG, M_AREG,
  55
  56         M_AIND, M_AIND, M_AIND, M_AIND,
  57         M_AIND, M_AIND, M_AIND, M_AIND,
  58
  59         M_APOSTINC, M_APOSTINC, M_APOSTINC, M_APOSTINC,
  60         M_APOSTINC, M_APOSTINC, M_APOSTINC, M_APOSTINC,
  61
  62         M_APREDEC, M_APREDEC, M_APREDEC, M_APREDEC,
  63         M_APREDEC, M_APREDEC, M_APREDEC, M_APREDEC,
  64
  65         M_ADISP, M_ADISP, M_ADISP, M_ADISP,
  66         M_ADISP, M_ADISP, M_ADISP, M_ADISP,
  67
  68         M_AINDEXED, M_AINDEXED, M_AINDEXED, M_AINDEXED,
  69         M_AINDEXED, M_AINDEXED, M_AINDEXED, M_AINDEXED,
  70
  71         M_ABSW,                                                                                 // 070
  72         M_ABSL,                                                                                 // 071
  73         M_PCDISP,                                                                               // 072
  74         M_PCINDEXED,                                                                    // 073
  75         M_IMMED,                                                                                // 074
  76         0L,                                                                                             // 075
  77         0L,                                                                                             // 076
  78         0L,                                                                                             // 077
  79         M_ABASE,                                                                                // 0100
  80         M_MEMPOST,                                                                              // 0101
  81         M_MEMPRE,                                                                               // 0102
  82         M_PCBASE,                                                                               // 0103
  83         M_PCMPOST,                                                                              // 0104
  84         M_PCMPRE,                                                                               // 0105
  85         M_AM_USP,                                                                               // 0106
  86         M_AM_SR,                                                                                // 0107
  87         M_AM_CCR,                                                                               // 0110
  88         M_AM_NONE                                                                               // 0111
  89 };                                                                                                      // 0112 length
  90
  91
  92 //
  93 // Initialize Line Processor
  94 //
  95 void InitLineProcessor(void)
  96 {
  97         disabled = 0;
  98         ifent = &ifent0;
  99         f_ifent = ifent0.if_prev = NULL;
 100         ifent0.if_state = 0;
 101 }
 102
 103
 104 //
 105 // Line Processor
 106 //
 107 void Assemble(void)
 108 {
 109         int state;                                      // Keyword machine state (output)
 110         int j;                                          // Random int, must be fast
 111         char * p;                                       // Random char ptr, must be fast
 112         TOKEN * tk;                                     // First token in line
 113         char * label;                           // Symbol (or NULL)
 114         char * equate;                          // Symbol (or NULL)
 115         int labtyp = 0;                         // Label type (':', DCOLON)
 116         int equtyp = 0;                         // Equ type ('=', DEQUALS)
 117         VALUE eval;                                     // Expression value
 118         WORD eattr;                                     // Expression attributes
 119         SYM * esym;                                     // External symbol involved in expr.
 120         WORD siz = 0;                           // Size suffix to mnem/diretve/macro
 121         LONG amsk0, amsk1;                      // Address-type masks for ea0, ea1
 122         MNTAB * m;                                      // Code generation table pointer
 123         SYM * sy, * sy2;                        // Symbol (temp usage)
 124         char * opname = NULL;           // Name of dirctve/mnemonic/macro
 125         int listflag;                           // 0: Don't call listeol()
 126         int as68mode = 0;                       // 1: Handle multiple labels
 127         WORD rmask;                                     // Register list, for REG
 128         int registerbank;                       // RISC register bank
 129         int riscreg;                            // RISC register
 130         listflag = 0;                           // Initialise listing flag
 131
 132 loop:                                                   // Line processing loop label
 133
 134         // Get another line of tokens
 135         if (TokenizeLine() == TKEOF)
 136         {
 137 if (verb_flag) printf("Assemble: Found TKEOF flag...\n");
 138                 if (list_flag && listflag)                      // Flush last line of source
 139                         listeol();
 140
 141                 if (ifent->if_prev != NULL)                     // Check conditional token
 142                         error("hit EOF without finding matching .endif");
 143
 144                 return;
 145         }
 146
 147         DEBUG DumpTokenBuffer();
 148
 149         if (list_flag)
 150         {
 151                 if (listflag && listing > 0)
 152                         listeol();                                              // Tell listing generator about EOL
 153
 154                 lstout((char)(disabled ? '-' : lntag)); // Prepare new line for listing
 155                 listflag = 1;                                           // OK to call `listeol' now
 156                 just_bss = 0;                                           // Reset just_bss mode
 157         }
 158
 159         state = -3;                                                             // No keyword (just EOL)
 160         label = NULL;                                                   // No label
 161         lab_sym = NULL;                                                 // No (exported) label
 162         equate = NULL;                                                  // No equate
 163         tk = tok;                                                               // Save first token in line
 164         pcloc = (VALUE)sloc;                                    // Set beginning-of-line PC
 165
 166 loop1:                                                                          // Internal line processing loop
 167
 168         if (*tok == EOL)                                                // Restart loop if end-of-line
 169                 goto loop;
 170
 171         // First token MUST be a symbol
 172         if (*tok != SYMBOL)
 173         {
 174                 error(syntax_error);
 175                 goto loop;
 176         }
 177
 178         j = (int)tok[2];                                                // Skip equates (normal statements)
 179
 180         if (j == '=' || j == DEQUALS || j == SET || j == REG || j == EQUREG || j == CCDEF)
 181         {
 182                 equate = string[tok[1]];
 183                 equtyp = j;
 184                 tok += 3;
 185                 goto normal;
 186         }
 187
 188         // Skip past label (but record it)
 189         if (j == ':' || j == DCOLON)
 190         {
 191 as68label:
 192 //              label = (char *)tok[1];                         // Get label name
 193                 label = string[tok[1]];                         // Get label name
 194                 labtyp = tok[2];                                        // Get label type
 195                 tok += 3;                                                       // Go to next line token
 196
 197                 // Handle multiple labels; if there's another label, go process it,
 198                 // and come back at `as68label' above.
 199                 if (as68_flag)
 200                 {
 201                         as68mode = 0;
 202
 203                         if (*tok == SYMBOL && tok[2] == ':')
 204                         {
 205                                 as68mode = 1;
 206                                 goto do_label;
 207                         }
 208                 }
 209         }
 210
 211         // EOL is legal here...
 212         if (*tok == EOL)
 213                 goto normal;
 214
 215         // Next token MUST be a symbol
 216         if (*tok++ != SYMBOL)
 217         {
 218                 error(syntax_error);
 219                 goto loop;
 220         }
 221
 222 // This is the problem here: On 64-bit platforms, this cuts the native pointer
 223 // in half. We need to figure out how to fix this.
 224 //#warning "!!! Bad pointer !!!"
 225 #if 0
 226         opname = p = (char *)*tok++;                    // Store opcode name here
 227 #else
 228         opname = p = string[*tok++];
 229 #endif
 230
 231         // Check to see if the SYMBOL is a keyword (a mnemonic or directive).
 232         // On output, `state' will have one of the values:
 233         //    -3          there was no symbol (EOL)
 234         //    -2..-1      the symbol didn't match any keyword
 235         //    0..499      vanilla directives (dc, ds, etc.)
 236         //    500..999    electric directives (macro, rept, etc.)
 237         //    1000..+     mnemonics (move, lsr, etc.)
 238         for(state=0; state>=0;)
 239         {
 240                 j = mnbase[state] + (int)tolowertab[*p];
 241
 242                 // Reject, character doesn't match
 243                 if (mncheck[j] != state)
 244                 {
 245                         state = -1;                                             // No match
 246                         break;
 247                 }
 248
 249                 // Must accept or reject at EOS
 250                 if (!*++p)
 251                 {
 252                         state = mnaccept[j];                    // (-1 on no terminal match)
 253                         break;
 254                 }
 255
 256                 state = mntab[j];
 257         }
 258
 259         // Check for ".b" ".w" ".l" after directive, macro or mnemonic.
 260         siz = SIZN;
 261
 262         if (*tok == DOTW)
 263                 siz = SIZW, tok++;
 264         else if (*tok == DOTL)
 265                 siz = SIZL, tok++;
 266         else if (*tok == DOTB)
 267                 siz = SIZB, tok++;
 268
 269         // Do special directives (500..999) (These must be handled in "real time")
 270         if (state >= 500 && state < 1000)
 271         {
 272                 switch (state)
 273                 {
 274                 case MN_IF:
 275                         d_if ();
 276                 goto loop;
 277                 case MN_ELSE:
 278                         d_else();
 279                         goto loop;
 280                 case MN_ENDIF:
 281                         d_endif ();
 282                         goto loop;
 283                 case MN_IIF:                                            // .iif --- immediate if
 284                         if (disabled || expr(exprbuf, &eval, &eattr, &esym) != OK)
 285                                 goto loop;
 286
 287                         if (!(eattr & DEFINED))
 288                         {
 289                                 error(undef_error);
 290                                 goto loop;
 291                         }
 292
 293                         if (*tok++ != ',')
 294                         {
 295                                 error(comma_error);
 296                                 goto loop;
 297                         }
 298
 299                         if (eval == 0)
 300                                 goto loop;
 301
 302                         goto loop1;
 303                 case MN_MACRO:                                          // .macro --- macro definition
 304                         if (!disabled)
 305                         {
 306                                 if (label != NULL)
 307                                         warn(lab_ignored);
 308
 309                                 DefineMacro();
 310                         }
 311
 312                         goto loop;
 313                 case MN_EXITM:                                          // .exitm --- exit macro
 314                 case MN_ENDM:                                           // .endm --- same as .exitm
 315                         if (!disabled)
 316                         {
 317                                 if (label != NULL)
 318                                         warn(lab_ignored);
 319
 320                                 ExitMacro();
 321                         }
 322
 323                         goto loop;
 324                 case MN_REPT:
 325                         if (!disabled)
 326                         {
 327                                 if (label != NULL)
 328                                         warn(lab_ignored);
 329
 330                                 defrept();
 331                         }
 332
 333                         goto loop;
 334                 case MN_ENDR:
 335                         if (!disabled)
 336                                 error("mis-nested .endr");
 337
 338                         goto loop;
 339                 }
 340         }
 341
 342 normal:
 343         if (disabled)                                                   // Conditionally disabled code
 344                 goto loop;
 345
 346         // Do equates
 347         if (equate != NULL)
 348         {
 349                 // Pick global or local symbol enviroment
 350 #if 0
 351                 j = 0;
 352
 353                 if (*equate == '.')
 354                         j = curenv;
 355 #else
 356                 j = (*equate == '.' ? curenv : 0);
 357 #endif
 358                 sy = lookup(equate, LABEL, j);
 359
 360                 if (sy == NULL)
 361                 {
 362                         sy = NewSymbol(equate, LABEL, j);
 363                         sy->sattr = 0;
 364
 365                         if (equtyp == DEQUALS)
 366                         {
 367                                 // Can't GLOBAL a local symbol
 368                                 if (j)
 369                                 {
 370                                         error(locgl_error);
 371                                         goto loop;
 372                                 }
 373
 374                                 sy->sattr = GLOBAL;
 375                         }
 376                 }
 377                 else if ((sy->sattr & DEFINED) && equtyp != SET)
 378                 {
 379                         if ((equtyp == EQUREG) && (sy->sattre & UNDEF_EQUR))
 380                         {
 381 //REALLY?                               sy->sattre |= ~UNDEF_EQUR;
 382                                 sy->sattre &= ~UNDEF_EQUR;
 383                                 sy->svalue  = 0;
 384                         }
 385                         else if ((equtyp == CCDEF) && (sy->sattre & UNDEF_CC))
 386                         {
 387 //REALLY?                               sy->sattre |= ~UNDEF_CC;
 388                                 sy->sattre &= ~UNDEF_CC;
 389                                 sy->svalue = 0;
 390                         }
 391                         else
 392                         {
 393                                 errors("multiple equate to '%s'", sy->sname);
 394                                 goto loop;
 395                         }
 396                 }
 397
 398                 // Put symbol in "order of definition" list
 399                 if (!(sy->sattr & SDECLLIST))
 400                         sym_decl(sy);
 401
 402                 // Parse value to equate symbol to;
 403                 // o  .equr
 404                 // o  .reg
 405                 // o  everything else
 406                 if (equtyp == EQUREG)
 407                 {
 408 //Linko's request to issue a warning on labels that equated to the same register
 409 //would go here. Not sure how to implement it though. :-/
 410 /*
 411 Maybe like this way:
 412 have an array of bools with 64 entries. Whenever a register is equated, set the
 413 corresponding register bool to true. Whenever it's undef'ed, set it to false. When
 414 checking to see if it's already been equated, issue a warning.
 415 */
 416                         // Check that we are in a RISC section
 417                         if (!rgpu && !rdsp)
 418                         {
 419                                 error(".equr/.regequ must be defined in .gpu/.dsp section");
 420                                 goto loop;
 421                         }
 422
 423                         // Check for register to equate to
 424                         if ((*tok >= KW_R0) && (*tok <= KW_R31))
 425                         {
 426                                 sy->sattre  = EQUATEDREG | RISCSYM;     // Mark as equated register
 427                                 riscreg = (*tok - KW_R0);
 428 //is there any reason to do this, since we're putting this in svalue?
 429 //i'm thinking, no. Let's test that out! :-D
 430 //                              sy->sattre |= (riscreg << 8);           // Store register number
 431 //everything seems to build fine without it... We'll leave it here Just In Case(tm)
 432
 433 #define DEBODGE_REGBANK
 434 #ifdef DEBODGE_REGBANK
 435                                 // Default is current state of "regbank"
 436                                 registerbank = regbank;
 437 #else
 438                                 // Default is no register bank specified
 439                                 registerbank = BANK_N;
 440 #endif
 441
 442                                 // Check for ",<bank #>" override notation
 443                                 if ((tok[1] == ',') && (tok[2] == CONST))
 444                                 {
 445                                         // Advance token pointer to the constant
 446                                         tok += 3;
 447
 448                                         // Anything other than a 0 or a 1 will result in "No Bank"
 449                                         if (*tok == 0)
 450                                                 registerbank = BANK_0;
 451                                         else if (*tok == 1)
 452                                                 registerbank = BANK_1;
 453                                 }
 454
 455 #ifdef DEBODGE_REGBANK
 456                                 sy->sattre |= registerbank;     // Store register bank
 457 #else
 458 // What needs to happen here is to prime registerbank with regbank, then use
 459 // registerbank down below for the bank marking.
 460 #warning "!!! regbank <-> registerbank confusion here !!!"
 461 // The question here is why, if we're allowed to override the ".regbankN" rules above,
 462 // then why is it using the one set by the directive in the extended attributes and
 463 // not in what ends up in symbol->svalue?
 464 // ".regbankN" is not an original Madmac directive, so it's suspect
 465                                 sy->sattre |= regbank;          // Store register bank
 466 #endif
 467                                 eattr = ABS | DEFINED | GLOBAL;
 468 // & what does this $80000080 constant mean???
 469 //                              eval = 0x80000080 + (riscreg) + (registerbank << 8);
 470                                 eval = riscreg;
 471                                 tok++;
 472                         }
 473                         // Checking for a register symbol
 474                         else if (tok[0] == SYMBOL)
 475                         {
 476                                 sy2 = lookup(string[tok[1]], LABEL, j);
 477
 478                                 // Make sure symbol is a valid equreg
 479                                 if (!sy2 || !(sy2->sattre & EQUATEDREG))
 480                                 {
 481                                         error("invalid GPU/DSP .equr/.regequ definition");
 482                                         goto loop;
 483                                 }
 484                                 else
 485                                 {
 486                                         eattr = ABS | DEFINED | GLOBAL; // Copy symbols attributes
 487                                         sy->sattre = sy2->sattre;
 488                                         eval = (sy2->svalue & 0xFFFFF0FF);
 489                                         tok += 2;
 490                                 }
 491                         }
 492                         else
 493                         {
 494                                 error("invalid GPU/DSP .equr/.regequ definition");
 495                                 goto loop;
 496                         }
 497                 }
 498                 else if (equtyp == REG)
 499                 {
 500                         if (reglist(&rmask) < 0)
 501                                 goto loop;
 502
 503                         eval = (VALUE)rmask;
 504                         eattr = ABS | DEFINED;
 505                 }
 506                 else if (equtyp == CCDEF)
 507                 {
 508                         sy->sattre |= EQUATEDCC;
 509                         eattr = ABS | DEFINED | GLOBAL;
 510
 511                         if (tok[0] == SYMBOL)
 512                         {
 513                                 sy2 = lookup(string[tok[1]], LABEL, j);
 514
 515                                 if (!sy2 || !(sy2->sattre & EQUATEDCC))
 516                                 {
 517                                         error("invalid gpu/dsp .ccdef definition");
 518                                         goto loop;
 519                                 }
 520                                 else
 521                                 {
 522                                         eattr = ABS | DEFINED | GLOBAL;
 523                                         sy->sattre = sy2->sattre;
 524                                         eval = sy2->svalue;
 525                                         tok += 2;
 526                                 }
 527                         }
 528                         else if (expr(exprbuf, &eval, &eattr, &esym) != OK)
 529                                 goto loop;
 530                 }
 531                 //equ a equr
 532                 else if (*tok == SYMBOL)
 533                 {
 534                         sy2 = lookup(string[tok[1]], LABEL, j);
 535
 536                         if (sy2 && (sy2->sattre & EQUATEDREG))
 537                         {
 538                                 sy->stype = sy2->stype;
 539                                 sy->sattr = sy2->sattr;
 540                                 sy->sattre = sy2->sattre;
 541 //ICK                           sy->svalue = (sy2->svalue & 0xFFFFF0FF);
 542                                 sy->svalue = sy2->svalue;
 543                                 goto loop;
 544                         }
 545                         else if (expr(exprbuf, &eval, &eattr, &esym) != OK)
 546                                 goto loop;
 547                 }
 548                 else if (expr(exprbuf, &eval, &eattr, &esym) != OK)
 549                         goto loop;
 550
 551                 if (!(eattr & DEFINED))
 552                 {
 553                         error(undef_error);
 554                         goto loop;
 555                 }
 556
 557                 sy->sattr |= eattr | EQUATED;           // Symbol inherits value and attributes
 558                 sy->svalue = eval;
 559
 560                 if (list_flag)                                          // Put value in listing
 561                         listvalue(eval);
 562
 563                 at_eol();                                                       // Must be at EOL now
 564                 goto loop;
 565         }
 566
 567         // Do labels
 568         if (label != NULL)
 569         {
 570 do_label:
 571                 // Check for dot in front of label; means this is a local label if present
 572                 j = (*label == '.' ? curenv : 0);
 573                 sy = lookup(label, LABEL, j);
 574
 575                 if (sy == NULL)
 576                 {
 577                         sy = NewSymbol(label, LABEL, j);
 578                         sy->sattr = 0;
 579                         sy->sattre = RISCSYM;
 580                 }
 581                 else if (sy->sattr & DEFINED)
 582                 {
 583                         errors("multiply-defined label '%s'", label);
 584                         goto loop;
 585                 }
 586
 587                 // Put symbol in "order of definition" list
 588                 if (!(sy->sattr & SDECLLIST))
 589                         sym_decl(sy);
 590
 591                 if (orgactive)
 592                 {
 593                         sy->svalue = orgaddr;
 594                         sy->sattr |= ABS | DEFINED | EQUATED;
 595                 }
 596                 else
 597                 {
 598                         sy->svalue = sloc;
 599                         sy->sattr |= DEFINED | cursect;
 600                 }
 601
 602                 lab_sym = sy;
 603
 604                 if (!j)
 605                         curenv++;
 606
 607                 // Make label global
 608                 if (labtyp == DCOLON)
 609                 {
 610                         if (j)
 611                         {
 612                                 error(locgl_error);
 613                                 goto loop;
 614                         }
 615
 616                         sy->sattr |= GLOBAL;
 617                 }
 618
 619                 // If we're in as68 mode, and there's another label, go back and handle it
 620                 if (as68_flag && as68mode)
 621                         goto as68label;
 622         }
 623
 624         // Punt on EOL
 625         if (state == -3)
 626                 goto loop;
 627
 628         // If we are in GPU or DSP mode and still in need of a mnemonic then search
 629         // for one
 630         if ((rgpu || rdsp) && (state < 0 || state >= 1000))
 631         {
 632                 for(state=0, p=opname; state>=0;)
 633                 {
 634                         j = mrbase[state] + (int)tolowertab[*p];
 635
 636                         // Reject, character doesn't match
 637                         if (mrcheck[j] != state)
 638                         {
 639                                 state = -1;                                     // No match
 640                                 break;
 641                         }
 642
 643                         // Must accept or reject at EOS
 644                         if (!*++p)
 645                         {
 646                                 state = mraccept[j];            // (-1 on no terminal match)
 647                                 break;
 648                         }
 649
 650                         state = mrtab[j];
 651                 }
 652
 653                 // Call RISC code generator if we found a mnemonic
 654                 if (state >= 3000)
 655                 {
 656                         GenerateRISCCode(state);
 657                         goto loop;
 658                 }
 659         }
 660
 661         // Invoke macro or complain about bad mnemonic
 662         if (state < 0)
 663         {
 664                 if ((sy = lookup(opname, MACRO, 0)) != NULL)
 665                         InvokeMacro(sy, siz);
 666                 else
 667                         errors("unknown op '%s'", opname);
 668
 669                 goto loop;
 670         }
 671
 672         // Call directive handlers
 673         if (state < 500)
 674         {
 675                 (*dirtab[state])(siz);
 676                 goto loop;
 677         }
 678
 679         // Do mnemonics
 680         // o  can't deposit instrs in BSS or ABS
 681         // o  do automatic .EVEN for instrs
 682         // o  allocate space for largest possible instr
 683         // o  can't do ".b" operations with an address register
 684         if (scattr & SBSS)
 685         {
 686                 error("cannot initialize non-storage (BSS) section");
 687                 goto loop;
 688         }
 689
 690         if (sloc & 1)                                                   // Automatic .even
 691                 auto_even();
 692
 693         if (challoc - ch_size < 18)                             // Make sure have space in current chunk
 694                 chcheck(0);
 695
 696         m = &machtab[state - 1000];
 697
 698         // Call special-mode handler
 699         if (m->mnattr & CGSPECIAL)
 700         {
 701                 (*m->mnfunc)(m->mninst, siz);
 702                 goto loop;
 703         }
 704
 705         if (amode(1) < 0)                                               // Parse 0, 1 or 2 addr modes
 706                 goto loop;
 707
 708         if (*tok != EOL)
 709                 error(extra_stuff);
 710
 711         amsk0 = amsktab[am0];
 712         amsk1 = amsktab[am1];
 713
 714         // Catch attempts to use ".B" with an address register (yes, this check
 715         // does work at this level)
 716         if (siz == SIZB && (am0 == AREG || am1 == AREG))
 717         {
 718                 error("cannot use '.b' with an address register");
 719                 goto loop;
 720         }
 721
 722         for(;;)
 723         {
 724                 if ((m->mnattr & siz) && (amsk0 & m->mn0) != 0 && (amsk1 & m->mn1) != 0)
 725                 {
 726                         (*m->mnfunc)(m->mninst, siz);
 727                         goto loop;
 728                 }
 729
 730                 m = &machtab[m->mncont];
 731         }
 732 }
 733
 734
 735 //
 736 // .if, Start Conditional Assembly
 737 //
 738 int d_if(void)
 739 {
 740         IFENT * rif;
 741         WORD eattr;
 742         VALUE eval;
 743         SYM * esym;
 744
 745         // Alloc an IFENTRY
 746         if ((rif = f_ifent) == NULL)
 747                 rif = (IFENT *)malloc(sizeof(IFENT));
 748         else
 749                 f_ifent = rif->if_prev;
 750
 751         rif->if_prev = ifent;
 752         ifent = rif;
 753
 754         if (!disabled)
 755         {
 756                 if (expr(exprbuf, &eval, &eattr, &esym) != OK)
 757                         return 0;
 758
 759                 if ((eattr & DEFINED) == 0)
 760                         return error(undef_error);
 761
 762                 disabled = !eval;
 763         }
 764
 765         rif->if_state = (WORD)disabled;
 766         return 0;
 767 }
 768
 769
 770 //
 771 // .else, Do Alternate Case For .if
 772 //
 773 int d_else(void)
 774 {
 775         IFENT * rif = ifent;
 776
 777         if (rif->if_prev == NULL)
 778                 return error("mismatched .else");
 779
 780         if (disabled)
 781                 disabled = rif->if_prev->if_state;
 782         else
 783                 disabled = 1;
 784
 785         rif->if_state = (WORD)disabled;
 786         return 0;
 787 }
 788
 789
 790 //
 791 // .endif, End of conditional assembly block
 792 // This is also called by fpop() to pop levels of IFENTs in case a macro or
 793 // include file exits early with `exitm' or `end'.
 794 //
 795 int d_endif (void)
 796 {
 797         IFENT * rif = ifent;
 798
 799         if (rif->if_prev == NULL)
 800                 return error("mismatched .endif");
 801
 802         ifent = rif->if_prev;
 803         disabled = rif->if_prev->if_state;
 804         rif->if_prev = f_ifent;
 805         f_ifent = rif;
 806         return 0;
 807 }