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, 2017 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 "6502.h"
  11 #include "amode.h"
  12 #include "direct.h"
  13 #include "error.h"
  14 #include "expr.h"
  15 #include "listing.h"
  16 #include "mach.h"
  17 #include "macro.h"
  18 #include "riscasm.h"
  19 #include "sect.h"
  20 #include "symbol.h"
  21
  22 #define DEF_KW                                  // Declare keyword values
  23 #include "kwtab.h"                              // Incl generated keyword tables & defs
  24
  25 #define DEF_MN                                  // Incl 68k keyword definitions
  26 #define DECL_MN                                 // Incl 68k keyword state machine tables
  27 #include "mntab.h"
  28
  29 #define DEF_MR
  30 #define DECL_MR
  31 #include "risckw.h"
  32
  33 #define DEF_MP                                  // Include 6502 keyword definitions
  34 #define DECL_MP                                 // Include 6502 keyword state machine tables
  35 #include "6502kw.h"
  36
  37 IFENT * ifent;                                  // Current ifent
  38 static IFENT ifent0;                    // Root ifent
  39 static IFENT * f_ifent;                 // Freelist of ifents
  40 static int disabled;                    // Assembly conditionally disabled
  41 int just_bss;                                   // 1, ds.b in microprocessor mode
  42 VALUE pcloc;                                    // Value of "PC" at beginning of line
  43 SYM * lab_sym;                                  // Label on line (or NULL)
  44
  45 const char extra_stuff[] = "extra (unexpected) text found after addressing mode";
  46 const char comma_error[] = "missing comma";
  47 const char syntax_error[] = "syntax error";
  48 const char locgl_error[] = "cannot GLOBL local symbol";
  49 const char lab_ignored[] = "label ignored";
  50
  51 // Table to convert an addressing-mode number to a bitmask.
  52 LONG amsktab[0112] = {
  53         M_DREG, M_DREG, M_DREG, M_DREG,
  54         M_DREG, M_DREG, M_DREG, M_DREG,
  55
  56         M_AREG, M_AREG, M_AREG, M_AREG,
  57         M_AREG, M_AREG, M_AREG, M_AREG,
  58
  59         M_AIND, M_AIND, M_AIND, M_AIND,
  60         M_AIND, M_AIND, M_AIND, M_AIND,
  61
  62         M_APOSTINC, M_APOSTINC, M_APOSTINC, M_APOSTINC,
  63         M_APOSTINC, M_APOSTINC, M_APOSTINC, M_APOSTINC,
  64
  65         M_APREDEC, M_APREDEC, M_APREDEC, M_APREDEC,
  66         M_APREDEC, M_APREDEC, M_APREDEC, M_APREDEC,
  67
  68         M_ADISP, M_ADISP, M_ADISP, M_ADISP,
  69         M_ADISP, M_ADISP, M_ADISP, M_ADISP,
  70
  71         M_AINDEXED, M_AINDEXED, M_AINDEXED, M_AINDEXED,
  72         M_AINDEXED, M_AINDEXED, M_AINDEXED, M_AINDEXED,
  73
  74         M_ABSW,                                                                                 // 070
  75         M_ABSL,                                                                                 // 071
  76         M_PCDISP,                                                                               // 072
  77         M_PCINDEXED,                                                                    // 073
  78         M_IMMED,                                                                                // 074
  79         0L,                                                                                             // 075
  80         0L,                                                                                             // 076
  81         0L,                                                                                             // 077
  82         M_ABASE,                                                                                // 0100
  83         M_MEMPOST,                                                                              // 0101
  84         M_MEMPRE,                                                                               // 0102
  85         M_PCBASE,                                                                               // 0103
  86         M_PCMPOST,                                                                              // 0104
  87         M_PCMPRE,                                                                               // 0105
  88         M_AM_USP,                                                                               // 0106
  89         M_AM_SR,                                                                                // 0107
  90         M_AM_CCR,                                                                               // 0110
  91         M_AM_NONE                                                                               // 0111
  92 };                                                                                                      // 0112 length
  93
  94
  95 // Function prototypes
  96 int HandleLabel(char *, int);
  97
  98
  99 //
 100 // Initialize line processor
 101 //
 102 void InitLineProcessor(void)
 103 {
 104         disabled = 0;
 105         ifent = &ifent0;
 106         f_ifent = ifent0.if_prev = NULL;
 107         ifent0.if_state = 0;
 108 }
 109
 110
 111 //
 112 // Line processor
 113 //
 114 void Assemble(void)
 115 {
 116         int state;                                      // Keyword machine state (output)
 117         int j;                                          // Random int, must be fast
 118         char * p;                                       // Random char ptr, must be fast
 119         TOKEN * tk;                                     // First token in line
 120         char * label;                           // Symbol (or NULL)
 121         char * equate;                          // Symbol (or NULL)
 122         int labtyp = 0;                         // Label type (':', DCOLON)
 123         int equtyp = 0;                         // Equ type ('=', DEQUALS)
 124         VALUE eval;                                     // Expression value
 125         WORD eattr;                                     // Expression attributes
 126         SYM * esym;                                     // External symbol involved in expr.
 127         WORD siz = 0;                           // Size suffix to mnem/diretve/macro
 128         LONG amsk0, amsk1;                      // Address-type masks for ea0, ea1
 129         MNTAB * m;                                      // Code generation table pointer
 130         SYM * sy, * sy2;                        // Symbol (temp usage)
 131         char * opname = NULL;           // Name of dirctve/mnemonic/macro
 132         int listflag;                           // 0: Don't call listeol()
 133         WORD rmask;                                     // Register list, for REG
 134         int registerbank;                       // RISC register bank
 135         int riscreg;                            // RISC register
 136         listflag = 0;                           // Initialise listing flag
 137
 138 loop:                                                   // Line processing loop label
 139
 140         // Get another line of tokens
 141         if (TokenizeLine() == TKEOF)
 142         {
 143 if (debug) printf("Assemble: Found TKEOF flag...\n");
 144                 if (list_flag && listflag)                      // Flush last line of source
 145                         listeol();
 146
 147                 if (ifent->if_prev != NULL)                     // Check conditional token
 148                         error("hit EOF without finding matching .endif");
 149
 150                 return;
 151         }
 152
 153         DEBUG DumpTokenBuffer();
 154
 155         if (list_flag)
 156         {
 157                 if (listflag && listing > 0)
 158                         listeol();                                              // Tell listing generator about EOL
 159
 160                 lstout((char)(disabled ? '-' : lntag)); // Prepare new line for listing
 161                 listflag = 1;                                           // OK to call `listeol' now
 162                 just_bss = 0;                                           // Reset just_bss mode
 163         }
 164
 165         state = -3;                                                             // No keyword (just EOL)
 166         label = NULL;                                                   // No label
 167         lab_sym = NULL;                                                 // No (exported) label
 168         equate = NULL;                                                  // No equate
 169         tk = tok;                                                               // Save first token in line
 170         pcloc = (VALUE)sloc;                                    // Set beginning-of-line PC
 171
 172 loop1:                                                                          // Internal line processing loop
 173
 174         if (*tok == EOL)                                                // Restart loop if end-of-line
 175                 goto loop;
 176
 177         // First token MUST be a symbol (Shamus: not sure why :-/)
 178         if (*tok != SYMBOL)
 179         {
 180                 error("syntax error; expected symbol");
 181                 goto loop;
 182         }
 183
 184         j = (int)tok[2];                                                // Skip equates (normal statements)
 185
 186         if (j == '=' || j == DEQUALS || j == SET || j == REG || j == EQUREG || j == CCDEF)
 187         {
 188                 equate = string[tok[1]];
 189                 equtyp = j;
 190                 tok += 3;
 191                 goto normal;
 192         }
 193
 194         // Skip past label (but record it)
 195         if (j == ':' || j == DCOLON)
 196         {
 197 as68label:
 198                 label = string[tok[1]];                         // Get label name
 199                 labtyp = tok[2];                                        // Get label type
 200                 tok += 3;                                                       // Go to next line token
 201
 202                 // AS68 MODE:
 203                 // Looks like another label follows the previous one, so handle
 204                 // the previous one until there aren't any more
 205                 if (as68_flag && (*tok == SYMBOL && tok[2] == ':'))
 206                 {
 207                         if (HandleLabel(label, labtyp) != 0)
 208                                 goto loop;
 209
 210                         goto as68label;
 211                 }
 212         }
 213
 214         // EOL is legal here...
 215         if (*tok == EOL)
 216                 goto normal;
 217
 218         // Next token MUST be a symbol
 219         if (*tok++ != SYMBOL)
 220         {
 221                 error("syntax error; expected symbol");
 222                 goto loop;
 223         }
 224
 225         opname = p = string[*tok++];
 226
 227         // Check to see if the SYMBOL is a keyword (a mnemonic or directive).
 228         // On output, `state' will have one of the values:
 229         //    -3          there was no symbol (EOL)
 230         //    -2..-1      the symbol didn't match any keyword
 231         //    0..499      vanilla directives (dc, ds, etc.)
 232         //    500..999    electric directives (macro, rept, etc.)
 233         //    1000..+     mnemonics (move, lsr, etc.)
 234         for(state=0; state>=0;)
 235         {
 236                 j = mnbase[state] + (int)tolowertab[*p];
 237
 238                 // Reject, character doesn't match
 239                 if (mncheck[j] != state)
 240                 {
 241                         state = -1;                                             // No match
 242                         break;
 243                 }
 244
 245                 // Must accept or reject at EOS
 246                 if (!*++p)
 247                 {
 248                         state = mnaccept[j];                    // (-1 on no terminal match)
 249                         break;
 250                 }
 251
 252                 state = mntab[j];
 253         }
 254
 255         // Check for ".b" ".w" ".l" after directive, macro or mnemonic.
 256         siz = SIZN;
 257
 258         if (*tok == DOTW)
 259                 siz = SIZW, tok++;
 260         else if (*tok == DOTL)
 261                 siz = SIZL, tok++;
 262         else if (*tok == DOTB)
 263                 siz = SIZB, tok++;
 264
 265         // Do special directives (500..999) (These must be handled in "real time")
 266         if (state >= 500 && state < 1000)
 267         {
 268                 switch (state)
 269                 {
 270                 case MN_IF:
 271                         d_if();
 272                 goto loop;
 273                 case MN_ELSE:
 274                         d_else();
 275                         goto loop;
 276                 case MN_ENDIF:
 277                         d_endif();
 278                         goto loop;
 279                 case MN_IIF:                                            // .iif --- immediate if
 280                         if (disabled || expr(exprbuf, &eval, &eattr, &esym) != OK)
 281                                 goto loop;
 282
 283                         if (!(eattr & DEFINED))
 284                         {
 285                                 error(undef_error);
 286                                 goto loop;
 287                         }
 288
 289                         if (*tok++ != ',')
 290                         {
 291                                 error(comma_error);
 292                                 goto loop;
 293                         }
 294
 295                         if (eval == 0)
 296                                 goto loop;
 297
 298                         goto loop1;
 299                 case MN_MACRO:                                          // .macro --- macro definition
 300                         if (!disabled)
 301                         {
 302                                 // Label on a macro definition is bad mojo... Warn the user
 303                                 if (label != NULL)
 304                                         warn(lab_ignored);
 305
 306                                 DefineMacro();
 307                         }
 308
 309                         goto loop;
 310                 case MN_EXITM:                                          // .exitm --- exit macro
 311                 case MN_ENDM:                                           // .endm --- same as .exitm
 312                         if (!disabled)
 313                         {
 314                                 if (label != NULL)
 315                                         warn(lab_ignored);
 316
 317                                 ExitMacro();
 318                         }
 319
 320                         goto loop;
 321                 case MN_REPT:
 322                         if (!disabled)
 323                         {
 324                                 // Handle labels on REPT directive lines...
 325                                 if (label)
 326                                 {
 327                                         if (HandleLabel(label, labtyp) != 0)
 328                                                 goto loop;
 329                                 }
 330
 331                                 defrept();
 332                         }
 333
 334                         goto loop;
 335                 case MN_ENDR:
 336                         if (!disabled)
 337                                 error("mis-nested .endr");
 338
 339                         goto loop;
 340                 }
 341         }
 342
 343 normal:
 344         if (disabled)                                                   // Conditionally disabled code
 345                 goto loop;
 346
 347         // Do equates
 348         if (equate != NULL)
 349         {
 350                 // Pick global or local symbol enviroment
 351                 j = (*equate == '.' ? curenv : 0);
 352                 sy = lookup(equate, LABEL, j);
 353
 354                 if (sy == NULL)
 355                 {
 356                         sy = NewSymbol(equate, LABEL, j);
 357                         sy->sattr = 0;
 358
 359                         if (equtyp == DEQUALS)
 360                         {
 361                                 // Can't GLOBAL a local symbol
 362                                 if (j)
 363                                 {
 364                                         error(locgl_error);
 365                                         goto loop;
 366                                 }
 367
 368                                 sy->sattr = GLOBAL;
 369                         }
 370                 }
 371                 else if ((sy->sattr & DEFINED) && equtyp != SET)
 372                 {
 373                         if ((equtyp == EQUREG) && (sy->sattre & UNDEF_EQUR))
 374                         {
 375 //REALLY?                               sy->sattre |= ~UNDEF_EQUR;
 376                                 sy->sattre &= ~UNDEF_EQUR;
 377                                 sy->svalue = 0;
 378                         }
 379                         else if ((equtyp == CCDEF) && (sy->sattre & UNDEF_CC))
 380                         {
 381 //REALLY?                               sy->sattre |= ~UNDEF_CC;
 382                                 sy->sattre &= ~UNDEF_CC;
 383                                 sy->svalue = 0;
 384                         }
 385                         else
 386                         {
 387                                 errors("multiple equate to '%s'", sy->sname);
 388                                 goto loop;
 389                         }
 390                 }
 391
 392                 // Put symbol in "order of definition" list if it's not already there
 393                 AddToSymbolDeclarationList(sy);
 394
 395                 // Parse value to equate symbol to;
 396                 // o  .equr
 397                 // o  .reg
 398                 // o  everything else
 399                 if (equtyp == EQUREG)
 400                 {
 401 //Linko's request to issue a warning on labels that equated to the same
 402 //register would go here. Not sure how to implement it though. :-/
 403 /*
 404 Maybe like this way:
 405 have an array of bools with 64 entries. Whenever a register is equated, set the
 406 corresponding register bool to true. Whenever it's undef'ed, set it to false.
 407 When checking to see if it's already been equated, issue a warning.
 408 */
 409                         // Check that we are in a RISC section
 410                         if (!rgpu && !rdsp)
 411                         {
 412                                 error(".equr/.regequ must be defined in .gpu/.dsp section");
 413                                 goto loop;
 414                         }
 415
 416                         // Check for register to equate to
 417                         if ((*tok >= KW_R0) && (*tok <= KW_R31))
 418                         {
 419 //                              sy->sattre  = EQUATEDREG | RISCSYM;     // Mark as equated register
 420                                 sy->sattre  = EQUATEDREG;       // Mark as equated register
 421                                 riscreg = (*tok - KW_R0);
 422 //is there any reason to do this, since we're putting this in svalue?
 423 //i'm thinking, no. Let's test that out! :-D
 424 //                              sy->sattre |= (riscreg << 8);           // Store register number
 425 //everything seems to build fine without it... We'll leave it here Just In Case(tm)
 426
 427 #define DEBODGE_REGBANK
 428 #ifdef DEBODGE_REGBANK
 429                                 // Default is current state of "regbank"
 430                                 registerbank = regbank;
 431 #else
 432                                 // Default is no register bank specified
 433                                 registerbank = BANK_N;
 434 #endif
 435
 436                                 // Check for ",<bank #>" override notation
 437                                 if ((tok[1] == ',') && (tok[2] == CONST))
 438                                 {
 439                                         // Advance token pointer to the constant
 440                                         tok += 3;
 441
 442                                         // Anything other than a 0 or a 1 will result in "No Bank"
 443                                         if (*tok == 0)
 444                                                 registerbank = BANK_0;
 445                                         else if (*tok == 1)
 446                                                 registerbank = BANK_1;
 447                                 }
 448
 449 #ifdef DEBODGE_REGBANK
 450                                 sy->sattre |= registerbank;     // Store register bank
 451 #else
 452 // What needs to happen here is to prime registerbank with regbank, then use
 453 // registerbank down below for the bank marking.
 454 #warning "!!! regbank <-> registerbank confusion here !!!"
 455 // The question here is why, if we're allowed to override the ".regbankN" rules
 456 // above, then why is it using the one set by the directive in the extended
 457 // attributes and not in what ends up in symbol->svalue?
 458 // ".regbankN" is not an original Madmac directive, so it's suspect
 459                                 sy->sattre |= regbank;          // Store register bank
 460 #endif
 461                                 eattr = ABS | DEFINED | GLOBAL;
 462 // & what does this $80000080 constant mean???
 463 //                              eval = 0x80000080 + (riscreg) + (registerbank << 8);
 464                                 eval = riscreg;
 465                                 tok++;
 466                         }
 467                         // Checking for a register symbol
 468                         else if (tok[0] == SYMBOL)
 469                         {
 470                                 sy2 = lookup(string[tok[1]], LABEL, j);
 471
 472                                 // Make sure symbol is a valid equreg
 473                                 if (!sy2 || !(sy2->sattre & EQUATEDREG))
 474                                 {
 475                                         error("invalid GPU/DSP .equr/.regequ definition");
 476                                         goto loop;
 477                                 }
 478                                 else
 479                                 {
 480                                         eattr = ABS | DEFINED | GLOBAL; // Copy symbols attributes
 481                                         sy->sattre = sy2->sattre;
 482                                         eval = (sy2->svalue & 0xFFFFF0FF);
 483                                         tok += 2;
 484                                 }
 485                         }
 486                         else
 487                         {
 488                                 error("invalid GPU/DSP .equr/.regequ definition");
 489                                 goto loop;
 490                         }
 491                 }
 492                 else if (equtyp == REG)
 493                 {
 494                         if (reglist(&rmask) < 0)
 495                                 goto loop;
 496
 497                         eval = (VALUE)rmask;
 498                         eattr = ABS | DEFINED;
 499                 }
 500                 else if (equtyp == CCDEF)
 501                 {
 502                         sy->sattre |= EQUATEDCC;
 503                         eattr = ABS | DEFINED | GLOBAL;
 504
 505                         if (tok[0] == SYMBOL)
 506                         {
 507                                 sy2 = lookup(string[tok[1]], LABEL, j);
 508
 509                                 if (!sy2 || !(sy2->sattre & EQUATEDCC))
 510                                 {
 511                                         error("invalid gpu/dsp .ccdef definition");
 512                                         goto loop;
 513                                 }
 514                                 else
 515                                 {
 516                                         eattr = ABS | DEFINED | GLOBAL;
 517                                         sy->sattre = sy2->sattre;
 518                                         eval = sy2->svalue;
 519                                         tok += 2;
 520                                 }
 521                         }
 522                         else if (expr(exprbuf, &eval, &eattr, &esym) != OK)
 523                                 goto loop;
 524                 }
 525                 //equ a equr
 526                 else if (*tok == SYMBOL)
 527                 {
 528                         sy2 = lookup(string[tok[1]], LABEL, j);
 529
 530                         if (sy2 && (sy2->sattre & EQUATEDREG))
 531                         {
 532                                 sy->stype = sy2->stype;
 533                                 sy->sattr = sy2->sattr;
 534                                 sy->sattre = sy2->sattre;
 535 //ICK                           sy->svalue = (sy2->svalue & 0xFFFFF0FF);
 536                                 sy->svalue = sy2->svalue;
 537                                 goto loop;
 538                         }
 539                         else if (expr(exprbuf, &eval, &eattr, &esym) != OK)
 540                                 goto loop;
 541                 }
 542                 else if (expr(exprbuf, &eval, &eattr, &esym) != OK)
 543                         goto loop;
 544
 545                 if (!(eattr & DEFINED))
 546                 {
 547                         error(undef_error);
 548                         goto loop;
 549                 }
 550
 551                 sy->sattr |= eattr | EQUATED;   // Symbol inherits value and attributes
 552                 sy->svalue = eval;
 553
 554                 if (list_flag)                                  // Put value in listing
 555                         listvalue(eval);
 556
 557                 at_eol();                                               // Must be at EOL now
 558                 goto loop;
 559         }
 560
 561         // Do labels
 562         if (label != NULL)
 563         {
 564                 // Non-zero == error occurred
 565                 if (HandleLabel(label, labtyp) != 0)
 566                         goto loop;
 567         }
 568
 569         // Punt on EOL
 570         if (state == -3)
 571                 goto loop;
 572
 573         // If we're in 6502 mode and are still in need of a mnemonic, then search
 574         // for valid 6502 mnemonic.
 575         if (m6502 && (state < 0 || state >= 1000))
 576         {
 577 #ifdef ST
 578                 state = kmatch(opname, mpbase, mpcheck, mptab, mpaccept);
 579 #else
 580                 for(state=0, p=opname; state>= 0; )
 581                 {
 582                         j = mpbase[state] + tolowertab[*p];
 583
 584                         if (mpcheck[j] != state)        // Reject, character doesn't match
 585                         {
 586                                 state = -1;             // No match
 587                                 break;
 588                         }
 589
 590                         if (!*++p)
 591                         {                       // Must accept or reject at EOS
 592                                 state = mpaccept[j];    // (-1 on no terminal match)
 593                                 break;
 594                         }
 595
 596                         state = mptab[j];
 597                 }
 598 #endif
 599
 600                 // Call 6502 code generator if we found a mnemonic
 601                 if (state >= 2000)
 602                 {
 603                         m6502cg(state - 2000);
 604                         goto loop;
 605                 }
 606         }
 607
 608         // If we are in GPU or DSP mode and still in need of a mnemonic then search
 609         // for one
 610         if ((rgpu || rdsp) && (state < 0 || state >= 1000))
 611         {
 612                 for(state=0, p=opname; state>=0;)
 613                 {
 614                         j = mrbase[state] + (int)tolowertab[*p];
 615
 616                         // Reject, character doesn't match
 617                         if (mrcheck[j] != state)
 618                         {
 619                                 state = -1;                                     // No match
 620                                 break;
 621                         }
 622
 623                         // Must accept or reject at EOS
 624                         if (!*++p)
 625                         {
 626                                 state = mraccept[j];            // (-1 on no terminal match)
 627                                 break;
 628                         }
 629
 630                         state = mrtab[j];
 631                 }
 632
 633                 // Call RISC code generator if we found a mnemonic
 634                 if (state >= 3000)
 635                 {
 636                         GenerateRISCCode(state);
 637                         goto loop;
 638                 }
 639         }
 640
 641         // Invoke macro or complain about bad mnemonic
 642         if (state < 0)
 643         {
 644                 if ((sy = lookup(opname, MACRO, 0)) != NULL)
 645                         InvokeMacro(sy, siz);
 646                 else
 647                         errors("unknown op '%s'", opname);
 648
 649                 goto loop;
 650         }
 651
 652         // Call directive handlers
 653         if (state < 500)
 654         {
 655                 (*dirtab[state])(siz);
 656                 goto loop;
 657         }
 658
 659         // Do mnemonics
 660         // o  can't deposit instrs in BSS or ABS
 661         // o  do automatic .EVEN for instrs
 662         // o  allocate space for largest possible instr
 663         // o  can't do ".b" operations with an address register
 664         if (scattr & SBSS)
 665         {
 666                 error("cannot initialize non-storage (BSS) section");
 667                 goto loop;
 668         }
 669
 670         if (sloc & 1)                                   // Automatic .even
 671                 auto_even();
 672
 673         if (challoc - ch_size < 18)             // Make sure have space in current chunk
 674                 chcheck(0);
 675
 676         m = &machtab[state - 1000];
 677
 678         // Call special-mode handler
 679         if (m->mnattr & CGSPECIAL)
 680         {
 681                 (*m->mnfunc)(m->mninst, siz);
 682                 goto loop;
 683         }
 684
 685         if (amode(1) < 0)                               // Parse 0, 1 or 2 addr modes
 686                 goto loop;
 687
 688         if (*tok != EOL)
 689                 error(extra_stuff);
 690
 691         amsk0 = amsktab[am0];
 692         amsk1 = amsktab[am1];
 693
 694         // Catch attempts to use ".B" with an address register (yes, this check
 695         // does work at this level)
 696         if (siz == SIZB && (am0 == AREG || am1 == AREG))
 697         {
 698                 error("cannot use '.b' with an address register");
 699                 goto loop;
 700         }
 701
 702         // Keep a backup of chptr (used for optimisations during codegen)
 703         chptr_opcode = chptr;
 704
 705         for(;;)
 706         {
 707                 if ((m->mnattr & siz) && (amsk0 & m->mn0) != 0 && (amsk1 & m->mn1) != 0)
 708                 {
 709                         (*m->mnfunc)(m->mninst, siz);
 710                         goto loop;
 711                 }
 712
 713                 m = &machtab[m->mncont];
 714         }
 715 }
 716
 717
 718 //
 719 // Handle the creation of labels
 720 //
 721 int HandleLabel(char * label, int labelType)
 722 {
 723         // Check for dot in front of label; means this is a local label if present
 724         int environment = (*label == '.' ? curenv : 0);
 725         SYM * symbol = lookup(label, LABEL, environment);
 726
 727         if (symbol == NULL)
 728         {
 729                 symbol = NewSymbol(label, LABEL, environment);
 730                 symbol->sattr = 0;
 731 //              symbol->sattre = RISCSYM;
 732                 symbol->sattre = 0;
 733         }
 734         else if (symbol->sattr & DEFINED)
 735                 return errors("multiply-defined label '%s'", label);
 736
 737         // Put symbol in "order of definition" list if it's not already in it
 738         AddToSymbolDeclarationList(symbol);
 739
 740         if (orgactive)
 741         {
 742                 symbol->svalue = orgaddr;
 743                 symbol->sattr |= ABS | DEFINED | EQUATED;
 744         }
 745         else
 746         {
 747                 symbol->svalue = sloc;
 748                 symbol->sattr |= DEFINED | cursect;
 749         }
 750
 751         lab_sym = symbol;
 752
 753         if (0 == environment)
 754                 curenv++;
 755
 756         // Make label global if it has a double colon
 757         if (labelType == DCOLON)
 758         {
 759                 if (environment != 0)
 760                         return error(locgl_error);
 761
 762                 symbol->sattr |= GLOBAL;
 763         }
 764
 765         return 0;
 766 }
 767
 768
 769 //
 770 // .if, Start conditional assembly
 771 //
 772 int d_if(void)
 773 {
 774         IFENT * rif;
 775         WORD eattr;
 776         VALUE eval;
 777         SYM * esym;
 778
 779         // Alloc an IFENTRY
 780         if ((rif = f_ifent) == NULL)
 781                 rif = (IFENT *)malloc(sizeof(IFENT));
 782         else
 783                 f_ifent = rif->if_prev;
 784
 785         rif->if_prev = ifent;
 786         ifent = rif;
 787
 788         if (!disabled)
 789         {
 790                 if (expr(exprbuf, &eval, &eattr, &esym) != OK)
 791                         return 0;
 792
 793                 if ((eattr & DEFINED) == 0)
 794                         return error(undef_error);
 795
 796                 disabled = !eval;
 797         }
 798
 799         rif->if_state = (WORD)disabled;
 800         return 0;
 801 }
 802
 803
 804 //
 805 // .else, Do alternate case for .if
 806 //
 807 int d_else(void)
 808 {
 809         IFENT * rif = ifent;
 810
 811         if (rif->if_prev == NULL)
 812                 return error("mismatched .else");
 813
 814         if (disabled)
 815                 disabled = rif->if_prev->if_state;
 816         else
 817                 disabled = 1;
 818
 819         rif->if_state = (WORD)disabled;
 820         return 0;
 821 }
 822
 823
 824 //
 825 // .endif, End of conditional assembly block
 826 // This is also called by fpop() to pop levels of IFENTs in case a macro or
 827 // include file exits early with `exitm' or `end'.
 828 //
 829 int d_endif (void)
 830 {
 831         IFENT * rif = ifent;
 832
 833         if (rif->if_prev == NULL)
 834                 return error("mismatched .endif");
 835
 836         ifent = rif->if_prev;
 837         disabled = rif->if_prev->if_state;
 838         rif->if_prev = f_ifent;
 839         f_ifent = rif;
 840         return 0;
 841 }
 842