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