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