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