-
Notifications
You must be signed in to change notification settings - Fork 0
/
386.ORP.Mod.txt
1033 lines (983 loc) · 43 KB
/
386.ORP.Mod.txt
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
MODULE ORP; (*N. Wirth 1.7.97 / 8.3.2020 Oberon compiler for Intel 386 in Oberon-07*)
IMPORT Texts, Oberon, ORS, ORB, ORG;
(*Author: Niklaus Wirth, 2014.
Parser of Oberon-RISC compiler. Uses Scanner ORS to obtain symbols (tokens),
ORB for definition of data structures and for handling import and export, and
ORG to produce binary code. ORP performs type checking and data allocation.
Parser is target-independent, except for part of the handling of allocations.*)
TYPE PtrBase = POINTER TO PtrBaseDesc;
PtrBaseDesc = RECORD (*list of names of pointer base types*)
name: ORS.Ident; type: ORB.Type; next: PtrBase
END ;
VAR sym: INTEGER; (*last symbol read*)
dc: LONGINT; (*data counter*)
level, exno, version: INTEGER;
newSF: BOOLEAN; (*option flag*)
expression: PROCEDURE (VAR x: ORG.Item); (*to avoid forward reference*)
Type: PROCEDURE (VAR type: ORB.Type);
FormalType: PROCEDURE (VAR typ: ORB.Type; dim: INTEGER);
modid: ORS.Ident;
pbsList: PtrBase; (*list of names of pointer base types*)
dummy: ORB.Object;
W: Texts.Writer;
PROCEDURE Check(s: INTEGER; msg: ARRAY OF CHAR);
BEGIN
IF sym = s THEN ORS.Get(sym) ELSE ORS.Mark(msg) END
END Check;
PROCEDURE qualident(VAR obj: ORB.Object);
BEGIN obj := ORB.thisObj(); ORS.Get(sym);
IF obj = NIL THEN ORS.Mark("undef"); obj := dummy END ;
IF (sym = ORS.period) & (obj.class = ORB.Mod) THEN
ORS.Get(sym);
IF sym = ORS.ident THEN obj := ORB.thisimport(obj); ORS.Get(sym);
IF obj = NIL THEN ORS.Mark("undef"); obj := dummy END
ELSE ORS.Mark("identifier expected"); obj := dummy
END
END
END qualident;
PROCEDURE CheckBool(VAR x: ORG.Item);
BEGIN
IF x.type.form # ORB.Bool THEN ORS.Mark("not Boolean"); x.type := ORB.boolType END
END CheckBool;
PROCEDURE CheckInt(VAR x: ORG.Item);
BEGIN
IF x.type.form # ORB.Int THEN ORS.Mark("not Integer"); x.type := ORB.intType END
END CheckInt;
PROCEDURE CheckReal(VAR x: ORG.Item);
BEGIN
IF x.type.form # ORB.Real THEN ORS.Mark("not Real"); x.type := ORB.realType END
END CheckReal;
PROCEDURE CheckSet(VAR x: ORG.Item);
BEGIN
IF x.type.form # ORB.Set THEN ORS.Mark("not Set"); x.type := ORB.setType END
END CheckSet;
PROCEDURE CheckSetVal(VAR x: ORG.Item);
BEGIN
IF x.type.form # ORB.Int THEN ORS.Mark("not Int"); x.type := ORB.setType
ELSIF x.mode = ORB.Const THEN
IF (x.a < 0) OR (x.a >= 32) THEN ORS.Mark("invalid set") END
END
END CheckSetVal;
PROCEDURE CheckConst(VAR x: ORG.Item);
BEGIN
IF x.mode # ORB.Const THEN ORS.Mark("not a constant"); x.mode := ORB.Const END
END CheckConst;
PROCEDURE CheckReadOnly(VAR x: ORG.Item);
BEGIN
IF x.rdo THEN ORS.Mark("read-only") END
END CheckReadOnly;
PROCEDURE CheckExport(VAR expo: BOOLEAN);
BEGIN
IF sym = ORS.times THEN
expo := TRUE; ORS.Get(sym);
IF level # 0 THEN ORS.Mark("remove asterisk") END
ELSE expo := FALSE
END
END CheckExport;
PROCEDURE IsExtension(t0, t1: ORB.Type): BOOLEAN;
BEGIN (*t1 is an extension of t0*)
RETURN (t0 = t1) OR (t1 # NIL) & IsExtension(t0, t1.base)
END IsExtension;
(* expressions *)
PROCEDURE TypeTest(VAR x: ORG.Item; T: ORB.Type; guard: BOOLEAN);
VAR xt: ORB.Type;
BEGIN xt := x.type;
IF (T.form = xt.form ) & ((T.form = ORB.Pointer) OR (T.form = ORB.Record) & (x.mode = ORB.Par)) THEN
WHILE (xt # T) & (xt # NIL) DO xt := xt.base END ;
IF xt # T THEN xt := x.type;
IF xt.form = ORB.Pointer THEN
IF IsExtension(xt.base, T.base) THEN ORG.TypeTest(x, T.base, FALSE, guard); x.type := T
ELSE ORS.Mark("not an extension")
END
ELSIF (xt.form = ORB.Record) & (x.mode = ORB.Par) THEN
IF IsExtension(xt, T) THEN ORG.TypeTest(x, T, TRUE, guard); x.type := T
ELSE ORS.Mark("not an extension")
END
ELSE ORS.Mark("incompatible types")
END
ELSIF ~guard THEN ORG.TypeTest(x, NIL, FALSE, FALSE)
END
ELSE ORS.Mark("type mismatch")
END ;
IF ~guard THEN x.type := ORB.boolType END
END TypeTest;
PROCEDURE selector(VAR x: ORG.Item);
VAR y: ORG.Item; obj: ORB.Object;
BEGIN
WHILE (sym = ORS.lbrak) OR (sym = ORS.period) OR (sym = ORS.arrow)
OR (sym = ORS.lparen) & (x.type.form IN {ORB.Record, ORB.Pointer}) DO
IF sym = ORS.lbrak THEN
REPEAT ORS.Get(sym); expression(y);
IF x.type.form = ORB.Array THEN
CheckInt(y); ORG.Index(x, y); x.type := x.type.base
ELSE ORS.Mark("not an array")
END
UNTIL sym # ORS.comma;
Check(ORS.rbrak, "no ]")
ELSIF sym = ORS.period THEN ORS.Get(sym);
IF sym = ORS.ident THEN
IF x.type.form = ORB.Pointer THEN ORG.DeRef(x); x.type := x.type.base END ;
IF x.type.form = ORB.Record THEN
obj := ORB.thisfield(x.type); ORS.Get(sym);
IF obj # NIL THEN ORG.Field(x, obj); x.type := obj.type
ELSE ORS.Mark("undef")
END
ELSE ORS.Mark("not a record")
END
ELSE ORS.Mark("ident?")
END
ELSIF sym = ORS.arrow THEN
ORS.Get(sym);
IF x.type.form = ORB.Pointer THEN ORG.DeRef(x); x.type := x.type.base
ELSE ORS.Mark("not a pointer")
END
ELSIF (sym = ORS.lparen) & (x.type.form IN {ORB.Record, ORB.Pointer}) THEN (*type guard*)
ORS.Get(sym);
IF sym = ORS.ident THEN
qualident(obj);
IF obj.class = ORB.Typ THEN TypeTest(x, obj.type, TRUE)
ELSE ORS.Mark("guard type expected")
END
ELSE ORS.Mark("not an identifier")
END ;
Check(ORS.rparen, " ) missing")
END
END
END selector;
PROCEDURE EqualSignatures(t0, t1: ORB.Type): BOOLEAN;
VAR p0, p1: ORB.Object; com: BOOLEAN;
BEGIN com := TRUE;
IF (t0.base = t1.base) & (t0.nofpar = t1.nofpar) THEN
p0 := t0.dsc; p1 := t1.dsc;
WHILE p0 # NIL DO
IF (p0.class = p1.class) & (p0.rdo = p1.rdo) &
((p0.type = p1.type) OR
(p0.type.form = ORB.Array) & (p1.type.form = ORB.Array) & (p0.type.len = p1.type.len) & (p0.type.base = p1.type.base) OR
(p0.type.form = ORB.Proc) & (p1.type.form = ORB.Proc) & EqualSignatures(p0.type, p1.type))
THEN p0 := p0.next; p1 := p1.next
ELSE p0 := NIL; com := FALSE
END
END
ELSE com := FALSE
END ;
RETURN com
END EqualSignatures;
PROCEDURE CompTypes(t0, t1: ORB.Type; varpar: BOOLEAN): BOOLEAN;
BEGIN (*check for assignment compatibility*)
RETURN (t0 = t1) (*openarray assignment disallowed in ORG*)
OR (t0.form = ORB.Array) & (t1.form = ORB.Array) & (t0.base = t1.base) & (t0.len = t1.len)
OR (t0.form = ORB.Record) & (t1.form = ORB.Record) & IsExtension(t0, t1)
OR ~varpar &
((t0.form = ORB.Pointer) & (t1.form = ORB.Pointer) & IsExtension(t0.base, t1.base)
OR (t0.form = ORB.Proc) & (t1.form = ORB.Proc) & EqualSignatures(t0, t1)
OR (t0.form IN {ORB.Pointer, ORB.Proc}) & (t1.form = ORB.NilTyp))
END CompTypes;
PROCEDURE Parameter(par: ORB.Object);
VAR x: ORG.Item; varpar: BOOLEAN;
BEGIN expression(x);
IF par # NIL THEN
varpar := par.class = ORB.Par;
IF CompTypes(par.type, x.type, varpar) THEN
IF ~varpar THEN ORG.ValueParam(x)
ELSE (*par.class = Par*)
IF ~par.rdo THEN CheckReadOnly(x) END ;
ORG.VarParam(x, par.type)
END
ELSIF (x.type.form = ORB.Array) & (par.type.form = ORB.Array) &
(x.type.base = par.type.base) & (par.type.len < 0) THEN
IF ~par.rdo THEN CheckReadOnly(x) END ;
ORG.OpenArrayParam(x)
ELSIF (x.type.form = ORB.String) & varpar & par.rdo & (par.type.form = ORB.Array) &
(par.type.base.form = ORB.Char) & (par.type.len < 0) THEN ORG.StringParam(x)
ELSIF ~varpar & (par.type.form = ORB.Int) & (x.type.form = ORB.Int) THEN ORG.ValueParam(x) (*BYTE*)
ELSIF (x.type.form = ORB.String) & (x.b = 2) & (par.class = ORB.Var) & (par.type.form = ORB.Char) THEN
ORG.StrToChar(x); ORG.ValueParam(x)
ELSIF (par.type.form = ORB.Array) & (par.type.base = ORB.byteType) &
(par.type.len >= 0) & (par.type.size = x.type.size) THEN
ORG.VarParam(x, par.type)
ELSE ORS.Mark("incompatible parameters")
END
END
END Parameter;
PROCEDURE ParamList(VAR x: ORG.Item);
VAR n: INTEGER; par: ORB.Object;
BEGIN par := x.type.dsc; n := 0;
IF sym # ORS.rparen THEN
Parameter(par); n := 1;
WHILE sym <= ORS.comma DO
Check(ORS.comma, "comma?");
IF par # NIL THEN par := par.next END ;
INC(n); Parameter(par)
END ;
Check(ORS.rparen, ") missing")
ELSE ORS.Get(sym);
END ;
IF n < x.type.nofpar THEN ORS.Mark("too few params")
ELSIF n > x.type.nofpar THEN ORS.Mark("too many params")
END
END ParamList;
PROCEDURE StandFunc(VAR x: ORG.Item; fct: LONGINT; restyp: ORB.Type);
VAR y: ORG.Item; n, npar: LONGINT;
BEGIN Check(ORS.lparen, "no (");
npar := fct MOD 10; fct := fct DIV 10; expression(x); n := 1;
WHILE sym = ORS.comma DO ORS.Get(sym); expression(y); INC(n) END ;
Check(ORS.rparen, "no )");
IF n = npar THEN
IF fct = 0 THEN (*ABS*)
IF x.type.form IN {ORB.Int, ORB.Real} THEN ORG.Abs(x); restyp := x.type ELSE ORS.Mark("bad type") END
ELSIF fct = 1 THEN (*ODD*) CheckInt(x); ORG.Odd(x)
ELSIF fct = 2 THEN (*FLOOR*) CheckReal(x); ORG.Floor(x)
ELSIF fct = 3 THEN (*FLT*) CheckInt(x); ORG.Float(x)
ELSIF fct = 4 THEN (*ORD*)
IF x.type.form <= ORB.Proc THEN ORG.Ord(x)
ELSIF (x.type.form = ORB.String) & (x.b = 2) THEN ORG.StrToChar(x)
ELSE ORS.Mark("bad type")
END
ELSIF fct = 5 THEN (*CHR*) CheckInt(x); ORG.Ord(x)
ELSIF fct = 6 THEN (*LEN*)
IF x.type.form = ORB.Array THEN ORG.Len(x) ELSE ORS.Mark("not an array") END
ELSIF fct IN {7, 8, 9} THEN (*LSL, ASR, ROR*) CheckInt(y);
IF x.type.form IN {ORB.Int, ORB.Set} THEN ORG.Shift(fct-7, x, y); restyp := x.type ELSE ORS.Mark("bad type") END
ELSIF fct = 11 THEN (*ADC*) ORG.ADC(x, y)
ELSIF fct = 12 THEN (*SBC*) ORG.SBC(x, y)
ELSIF fct = 13 THEN (*UML*) ORG.UML(x, y)
ELSIF fct = 14 THEN (*BIT*) CheckInt(x); CheckInt(y); ORG.Bit(x, y)
ELSIF fct = 15 THEN (*REG*) CheckConst(x); CheckInt(x); ORG.Register(x)
ELSIF fct = 16 THEN (*VAL*)
IF (x.mode= ORB.Typ) & (x.type.size <= y.type.size) THEN restyp := x.type; x := y
ELSE ORS.Mark("casting not allowed")
END
ELSIF fct = 17 THEN (*ADR*) ORG.Adr(x)
ELSIF fct = 18 THEN (*SIZE*)
IF x.mode = ORB.Typ THEN ORG.MakeConstItem(x, ORB.intType, x.type.size)
ELSE ORS.Mark("must be a type")
END
ELSIF fct = 19 THEN (*COND*) CheckConst(x); CheckInt(x); ORG.Condition(x)
ELSIF fct = 20 THEN (*H*) CheckConst(x); CheckInt(x); ORG.H(x)
END ;
x.type := restyp
ELSE ORS.Mark("wrong nof params")
END
END StandFunc;
PROCEDURE element(VAR x: ORG.Item);
VAR y: ORG.Item;
BEGIN expression(x); CheckSetVal(x);
IF sym = ORS.upto THEN ORS.Get(sym); expression(y); CheckSetVal(y); ORG.Set(x, y)
ELSE ORG.Singleton(x)
END ;
x.type := ORB.setType
END element;
PROCEDURE set(VAR x: ORG.Item);
VAR y: ORG.Item;
BEGIN
IF sym >= ORS.if THEN
IF sym # ORS.rbrace THEN ORS.Mark(" } missing") END ;
ORG.MakeConstItem(x, ORB.setType, 0) (*empty set*)
ELSE element(x);
WHILE (sym < ORS.rparen) OR (sym > ORS.rbrace) DO
IF sym = ORS.comma THEN ORS.Get(sym)
ELSIF sym # ORS.rbrace THEN ORS.Mark("missing comma")
END ;
element(y); ORG.SetOp(ORS.plus, x, y)
END
END
END set;
PROCEDURE factor(VAR x: ORG.Item);
VAR obj: ORB.Object; rx: LONGINT;
BEGIN (*sync*)
IF (sym < ORS.char) OR (sym > ORS.ident) THEN ORS.Mark("expression expected");
REPEAT ORS.Get(sym) UNTIL (sym >= ORS.char) & (sym <= ORS.for) OR (sym >= ORS.then)
END ;
IF sym = ORS.ident THEN
qualident(obj);
IF obj.class = ORB.SFunc THEN StandFunc(x, obj.val, obj.type)
ELSE ORG.MakeItem(x, obj, level); selector(x);
IF sym = ORS.lparen THEN
ORS.Get(sym);
IF (x.type.form = ORB.Proc) & (x.type.base.form # ORB.NoTyp) THEN
ORG.PrepCall(x, rx); ParamList(x); ORG.Call(x, rx); x.type := x.type.base
ELSE ORS.Mark("not a function"); ParamList(x)
END
END
END
ELSIF sym = ORS.int THEN ORG.MakeConstItem(x, ORB.intType, ORS.ival); ORS.Get(sym)
ELSIF sym = ORS.real THEN ORG.MakeRealItem(x, ORS.rval); ORS.Get(sym)
ELSIF sym = ORS.char THEN ORG.MakeConstItem(x, ORB.charType, ORS.ival); ORS.Get(sym)
ELSIF sym = ORS.nil THEN ORS.Get(sym); ORG.MakeConstItem(x, ORB.nilType, 0)
ELSIF sym = ORS.string THEN ORG.MakeStringItem(x, ORS.slen); ORS.Get(sym)
ELSIF sym = ORS.lparen THEN ORS.Get(sym); expression(x); Check(ORS.rparen, "no )")
ELSIF sym = ORS.lbrace THEN ORS.Get(sym); set(x); Check(ORS.rbrace, "no }")
ELSIF sym = ORS.not THEN ORS.Get(sym); factor(x); CheckBool(x); ORG.Not(x)
ELSIF sym = ORS.false THEN ORS.Get(sym); ORG.MakeConstItem(x, ORB.boolType, 0)
ELSIF sym = ORS.true THEN ORS.Get(sym); ORG.MakeConstItem(x, ORB.boolType, 1)
ELSE ORS.Mark("not a factor"); ORG.MakeConstItem(x, ORB.intType, 0)
END
END factor;
PROCEDURE term(VAR x: ORG.Item);
VAR y: ORG.Item; op, f: INTEGER;
BEGIN factor(x); f := x.type.form;
WHILE (sym >= ORS.times) & (sym <= ORS.and) DO
op := sym; ORS.Get(sym);
IF op = ORS.times THEN
IF f = ORB.Int THEN factor(y); CheckInt(y); ORG.MulOp(x, y)
ELSIF f = ORB.Real THEN factor(y); CheckReal(y); ORG.RealOp(op, x, y)
ELSIF f = ORB.Set THEN factor(y); CheckSet(y); ORG.SetOp(op, x, y)
ELSE ORS.Mark("bad type")
END
ELSIF (op = ORS.div) OR (op = ORS.mod) THEN
CheckInt(x); factor(y); CheckInt(y); ORG.DivOp(op, x, y)
ELSIF op = ORS.rdiv THEN
IF f = ORB.Real THEN factor(y); CheckReal(y); ORG.RealOp(op, x, y)
ELSIF f = ORB.Set THEN factor(y); CheckSet(y); ORG.SetOp(op, x, y)
ELSE ORS.Mark("bad type")
END
ELSE (*op = and*) CheckBool(x); ORG.And1(x); factor(y); CheckBool(y); ORG.And2(x, y)
END
END
END term;
PROCEDURE SimpleExpression(VAR x: ORG.Item);
VAR y: ORG.Item; op: INTEGER;
BEGIN
IF sym = ORS.minus THEN ORS.Get(sym); term(x);
IF x.type.form IN {ORB.Int, ORB.Real, ORB.Set} THEN ORG.Neg(x) ELSE CheckInt(x) END
ELSIF sym = ORS.plus THEN ORS.Get(sym); term(x);
ELSE term(x)
END ;
WHILE (sym >= ORS.plus) & (sym <= ORS.or) DO
op := sym; ORS.Get(sym);
IF op = ORS.or THEN ORG.Or1(x); CheckBool(x); term(y); CheckBool(y); ORG.Or2(x, y)
ELSIF x.type.form = ORB.Int THEN term(y); CheckInt(y); ORG.AddOp(op, x, y)
ELSIF x.type.form = ORB.Real THEN term(y); CheckReal(y); ORG.RealOp(op, x, y)
ELSE CheckSet(x); term(y); CheckSet(y); ORG.SetOp(op, x, y)
END
END
END SimpleExpression;
PROCEDURE expression0(VAR x: ORG.Item);
VAR y: ORG.Item; obj: ORB.Object; rel, xf, yf: INTEGER;
BEGIN SimpleExpression(x);
IF (sym >= ORS.eql) & (sym <= ORS.geq) THEN
rel := sym; ORS.Get(sym); SimpleExpression(y); xf := x.type.form; yf := y.type.form;
IF x.type = y.type THEN
IF (xf IN {ORB.Char, ORB.Int}) THEN ORG.IntRelation(rel, x, y)
ELSIF xf = ORB.Real THEN ORG.RealRelation(rel, x, y)
ELSIF (xf IN {ORB.Set, ORB.Pointer, ORB.Proc, ORB.NilTyp, ORB.Bool}) THEN
IF rel <= ORS.neq THEN ORG.IntRelation(rel, x, y) ELSE ORS.Mark("only = or #") END
ELSIF (xf = ORB.Array) & (x.type.base.form = ORB.Char) OR (xf = ORB.String) THEN
ORG.StringRelation(rel, x, y)
ELSE ORS.Mark("illegal comparison")
END
ELSIF (xf IN {ORB.Pointer, ORB.Proc}) & (yf = ORB.NilTyp)
OR (yf IN {ORB.Pointer, ORB.Proc}) & (xf = ORB.NilTyp) THEN
IF rel <= ORS.neq THEN ORG.IntRelation(rel, x, y) ELSE ORS.Mark("only = or #") END
ELSIF (xf = ORB.Pointer) & (yf = ORB.Pointer) &
(IsExtension(x.type.base, y.type.base) OR IsExtension(y.type.base, x.type.base))
OR (xf = ORB.Proc) & (yf = ORB.Proc) & EqualSignatures(x.type, y.type) THEN
IF rel <= ORS.neq THEN ORG.IntRelation(rel, x, y) ELSE ORS.Mark("only = or #") END
ELSIF (xf = ORB.Array) & (x.type.base.form = ORB.Char) &
((yf = ORB.String) OR (yf = ORB.Array) & (y.type.base.form = ORB.Char))
OR (yf = ORB.Array) & (y.type.base.form = ORB.Char) & (xf = ORB.String) THEN
ORG.StringRelation(rel, x, y)
ELSIF (xf = ORB.Char) & (yf = ORB.String) & (y.b = 2) THEN
ORG.StrToChar(y); ORG.IntRelation(rel, x, y)
ELSIF (yf = ORB.Char) & (xf = ORB.String) & (x.b = 2) THEN
ORG.StrToChar(x); ORG.IntRelation(rel, x, y)
ELSIF (xf = ORB.Int) & (yf = ORB.Int) THEN ORG.IntRelation(rel, x, y) (*BYTE*)
ELSE ORS.Mark("illegal comparison")
END ;
x.type := ORB.boolType
ELSIF sym = ORS.in THEN
ORS.Get(sym); CheckInt(x); SimpleExpression(y); CheckSet(y); ORG.In(x, y) ;
x.type := ORB.boolType
ELSIF sym = ORS.is THEN
ORS.Get(sym); qualident(obj); TypeTest(x, obj.type, FALSE) ;
x.type := ORB.boolType
END
END expression0;
(* statements *)
PROCEDURE StandProc(pno: LONGINT);
VAR nap, npar: LONGINT; (*nof actual/formal parameters*)
x, y, z: ORG.Item;
BEGIN Check(ORS.lparen, "no (");
npar := pno MOD 10; pno := pno DIV 10; expression(x); nap := 1;
IF sym = ORS.comma THEN
ORS.Get(sym); expression(y); nap := 2; z.type := ORB.noType;
WHILE sym = ORS.comma DO ORS.Get(sym); expression(z); INC(nap) END
ELSE y.type := ORB.noType
END ;
Check(ORS.rparen, "no )");
IF (npar = nap) OR (pno IN {0, 1}) THEN
IF pno IN {0, 1} THEN (*INC, DEC*)
CheckInt(x); CheckReadOnly(x);
IF y.type # ORB.noType THEN CheckInt(y) END ;
ORG.Increment(pno, x, y)
ELSIF pno IN {2, 3} THEN (*INCL, EXCL*)
CheckSet(x); CheckReadOnly(x); CheckInt(y); ORG.Include(pno-2, x, y)
ELSIF pno = 4 THEN CheckBool(x); ORG.Assert(x)
ELSIF pno = 5 THEN(*NEW*) CheckReadOnly(x);
IF (x.type.form = ORB.Pointer) & (x.type.base.form = ORB.Record) THEN ORG.New(x)
ELSE ORS.Mark("not a pointer to record")
END
ELSIF pno = 6 THEN CheckReal(x); CheckInt(y); CheckReadOnly(x); ORG.Pack(x, y)
ELSIF pno = 7 THEN CheckReal(x); CheckInt(y); CheckReadOnly(x); ORG.Unpk(x, y)
ELSIF pno = 8 THEN
IF x.type.form <= ORB.Set THEN ORG.Led(x) ELSE ORS.Mark("bad type") END
ELSIF pno = 10 THEN CheckInt(x); ORG.Get(x, y)
ELSIF pno = 11 THEN CheckInt(x); ORG.Put(x, y)
ELSIF pno = 12 THEN CheckInt(x); CheckInt(y); CheckInt(z); ORG.Copy(x, y, z)
ELSIF pno = 13 THEN CheckConst(x); CheckInt(x); ORG.LDPSR(x)
ELSIF pno = 14 THEN CheckInt(x); ORG.LDREG(x, y)
END
ELSE ORS.Mark("wrong nof parameters")
END
END StandProc;
PROCEDURE StatSequence;
VAR obj: ORB.Object;
orgtype: ORB.Type; (*original type of case var*)
x, y, z, w: ORG.Item;
L0, L1, rx: LONGINT;
PROCEDURE TypeCase(obj: ORB.Object; VAR x: ORG.Item);
VAR typobj: ORB.Object;
BEGIN
IF sym = ORS.ident THEN
qualident(typobj); ORG.MakeItem(x, obj, level);
IF typobj.class # ORB.Typ THEN ORS.Mark("not a type") END ;
TypeTest(x, typobj.type, FALSE); obj.type := typobj.type;
ORG.CFJump(x); Check(ORS.colon, ": expected"); StatSequence
ELSE ORG.CFJump(x); ORS.Mark("type id expected")
END
END TypeCase;
PROCEDURE SkipCase;
BEGIN
WHILE sym # ORS.colon DO ORS.Get(sym) END ;
ORS.Get(sym); StatSequence
END SkipCase;
BEGIN (* StatSequence *)
REPEAT (*sync*) obj := NIL;
IF ~((sym >= ORS.ident) & (sym <= ORS.for) OR (sym >= ORS.semicolon)) THEN
ORS.Mark("statement expected");
REPEAT ORS.Get(sym) UNTIL (sym >= ORS.ident)
END ;
IF sym = ORS.ident THEN
qualident(obj); ORG.MakeItem(x, obj, level);
IF x.mode = ORB.SProc THEN StandProc(obj.val)
ELSE selector(x);
IF sym = ORS.becomes THEN (*assignment*)
ORS.Get(sym); CheckReadOnly(x); expression(y);
IF CompTypes(x.type, y.type, FALSE) THEN
IF (x.type.form <= ORB.Pointer) OR (x.type.form = ORB.Proc) THEN ORG.Store(x, y)
ELSE ORG.StoreStruct(x, y)
END
ELSIF (x.type.form = ORB.Array) & (y.type.form = ORB.Array) & (x.type.base = y.type.base) & (y.type.len < 0) THEN
ORG.StoreStruct(x, y)
ELSIF (x.type.form = ORB.Array) & (x.type.base.form = ORB.Char) & (y.type.form = ORB.String) THEN
ORG.CopyString(x, y)
ELSIF (x.type.form = ORB.Int) & (y.type.form = ORB.Int) THEN ORG.Store(x, y) (*BYTE*)
ELSIF (x.type.form = ORB.Char) & (y.type.form = ORB.String) & (y.b = 2) THEN
ORG.StrToChar(y); ORG.Store(x, y)
ELSE ORS.Mark("illegal assignment")
END
ELSIF sym = ORS.eql THEN ORS.Mark("should be :="); ORS.Get(sym); expression(y)
ELSIF sym = ORS.lparen THEN (*procedure call*)
ORS.Get(sym);
IF (x.type.form = ORB.Proc) & (x.type.base.form = ORB.NoTyp) THEN
ORG.PrepCall(x, rx); ParamList(x); ORG.Call(x, rx)
ELSE ORS.Mark("not a procedure"); ParamList(x)
END
ELSIF x.type.form = ORB.Proc THEN (*procedure call without parameters*)
IF x.type.nofpar > 0 THEN ORS.Mark("missing parameters") END ;
IF x.type.base.form = ORB.NoTyp THEN ORG.PrepCall(x, rx); ORG.Call(x, rx) ELSE ORS.Mark("not a procedure") END
ELSIF x.mode = ORB.Typ THEN ORS.Mark("illegal assignment")
ELSE ORS.Mark("not a procedure")
END
END
ELSIF sym = ORS.if THEN
ORS.Get(sym); expression(x); CheckBool(x); ORG.CFJump(x);
Check(ORS.then, "no THEN");
StatSequence; L0 := 0;
WHILE sym = ORS.elsif DO
ORS.Get(sym); ORG.FJump(L0); ORG.Fixup(x); expression(x); CheckBool(x);
ORG.CFJump(x); Check(ORS.then, "no THEN"); StatSequence
END ;
IF sym = ORS.else THEN ORS.Get(sym); ORG.FJump(L0); ORG.Fixup(x); StatSequence
ELSE ORG.Fixup(x)
END ;
ORG.FixLink(L0); Check(ORS.end, "no END")
ELSIF sym = ORS.while THEN
ORS.Get(sym); L0 := ORG.Here(); expression(x); CheckBool(x); ORG.CFJump(x);
Check(ORS.do, "no DO"); StatSequence; ORG.BJump(L0);
WHILE sym = ORS.elsif DO
ORS.Get(sym); ORG.Fixup(x); expression(x); CheckBool(x); ORG.CFJump(x);
Check(ORS.do, "no DO"); StatSequence; ORG.BJump(L0)
END ;
ORG.Fixup(x); Check(ORS.end, "no END")
ELSIF sym = ORS.repeat THEN
ORS.Get(sym); L0 := ORG.Here(); StatSequence;
IF sym = ORS.until THEN
ORS.Get(sym); expression(x); CheckBool(x); ORG.CBJump(x, L0)
ELSE ORS.Mark("missing UNTIL")
END
ELSIF sym = ORS.for THEN
ORS.Get(sym);
IF sym = ORS.ident THEN
qualident(obj); ORG.MakeItem(x, obj, level); CheckInt(x); CheckReadOnly(x);
IF sym = ORS.becomes THEN
ORS.Get(sym); expression(y); CheckInt(y); ORG.For0(x, y); L0 := ORG.Here();
Check(ORS.to, "no TO"); expression(z); CheckInt(z); obj.rdo := TRUE;
IF sym = ORS.by THEN ORS.Get(sym); expression(w); CheckConst(w); CheckInt(w)
ELSE ORG.MakeConstItem(w, ORB.intType, 1)
END ;
Check(ORS.do, "no DO"); ORG.For1(x, y, z, w, L1);
StatSequence; Check(ORS.end, "no END");
ORG.For2(x, y, w); ORG.BJump(L0); ORG.FixLink(L1); obj.rdo := FALSE
ELSE ORS.Mark(":= expected")
END
ELSE ORS.Mark("identifier expected")
END
ELSIF sym = ORS.case THEN
ORS.Get(sym);
IF sym = ORS.ident THEN
qualident(obj); orgtype := obj.type;
IF (orgtype.form = ORB.Pointer) OR (orgtype.form = ORB.Record) & (obj.class = ORB.Par) THEN
Check(ORS.of, "OF expected"); TypeCase(obj, x); L0 := 0;
WHILE sym = ORS.bar DO
ORS.Get(sym); ORG.FJump(L0); ORG.Fixup(x); obj.type := orgtype; TypeCase(obj, x)
END ;
ORG.Fixup(x); ORG.FixLink(L0); obj.type := orgtype
ELSE ORS.Mark("numeric case not implemented");
Check(ORS.of, "OF expected"); SkipCase;
WHILE sym = ORS.bar DO SkipCase END
END
ELSE ORS.Mark("ident expected")
END ;
Check(ORS.end, "no END")
END ;
ORG.CheckRegs;
IF sym = ORS.semicolon THEN ORS.Get(sym)
ELSIF sym < ORS.semicolon THEN ORS.Mark("missing semicolon?")
END
UNTIL sym > ORS.semicolon
END StatSequence;
(* Types and declarations *)
PROCEDURE IdentList(class: INTEGER; VAR first: ORB.Object);
VAR obj: ORB.Object;
BEGIN
IF sym = ORS.ident THEN
ORB.NewObj(first, ORS.id, class); ORS.Get(sym); CheckExport(first.expo);
WHILE sym = ORS.comma DO
ORS.Get(sym);
IF sym = ORS.ident THEN ORB.NewObj(obj, ORS.id, class); ORS.Get(sym); CheckExport(obj.expo)
ELSE ORS.Mark("ident?")
END
END;
IF sym = ORS.colon THEN ORS.Get(sym) ELSE ORS.Mark(":?") END
ELSE first := NIL
END
END IdentList;
PROCEDURE ArrayType(VAR type: ORB.Type);
VAR x: ORG.Item; typ: ORB.Type; len: LONGINT;
BEGIN NEW(typ); typ.form := ORB.NoTyp;
expression(x);
IF (x.mode = ORB.Const) & (x.type.form = ORB.Int) & (x.a >= 0) THEN len := x.a
ELSE len := 1; ORS.Mark("not a valid length")
END ;
IF sym = ORS.of THEN ORS.Get(sym); Type(typ.base);
IF (typ.base.form = ORB.Array) & (typ.base.len < 0) THEN ORS.Mark("dyn array not allowed") END
ELSIF sym = ORS.comma THEN ORS.Get(sym); ArrayType(typ.base)
ELSE ORS.Mark("missing OF"); typ.base := ORB.intType
END ;
typ.size := (len * typ.base.size + 3) DIV 4 * 4;
typ.form := ORB.Array; typ.len := len; type := typ
END ArrayType;
PROCEDURE RecordType(VAR type: ORB.Type);
VAR obj, obj0, new, bot, base: ORB.Object;
typ, tp: ORB.Type;
offset, off, n: LONGINT;
BEGIN NEW(typ); typ.form := ORB.NoTyp; typ.base := NIL; typ.mno := -level; typ.nofpar := 0; offset := 0; bot := NIL;
IF sym = ORS.lparen THEN
ORS.Get(sym); (*record extension*)
IF level # 0 THEN ORS.Mark("extension of local types not implemented") END ;
IF sym = ORS.ident THEN
qualident(base);
IF base.class = ORB.Typ THEN
IF base.type.form = ORB.Record THEN typ.base := base.type
ELSE typ.base := ORB.intType; ORS.Mark("invalid extension")
END ;
typ.nofpar := typ.base.nofpar + 1; (*"nofpar" here abused for extension level*)
bot := typ.base.dsc; offset := typ.base.size
ELSE ORS.Mark("type expected")
END
ELSE ORS.Mark("ident expected")
END ;
Check(ORS.rparen, "no )")
END ;
WHILE sym = ORS.ident DO (*fields*)
n := 0; obj := bot;
WHILE sym = ORS.ident DO
obj0 := obj;
WHILE (obj0 # NIL) & (obj0.name # ORS.id) DO obj0 := obj0.next END ;
IF obj0 # NIL THEN ORS.Mark("mult def") END ;
NEW(new); ORS.CopyId(new.name); new.class := ORB.Fld; new.next := obj; obj := new; INC(n);
ORS.Get(sym); CheckExport(new.expo);
IF (sym # ORS.comma) & (sym # ORS.colon) THEN ORS.Mark("comma expected")
ELSIF sym = ORS.comma THEN ORS.Get(sym)
END
END ;
Check(ORS.colon, "colon expected"); Type(tp);
IF (tp.form = ORB.Array) & (tp.len < 0) THEN ORS.Mark("dyn array not allowed") END ;
IF tp.size > 1 THEN offset := (offset+3) DIV 4 * 4 END ;
offset := offset + n * tp.size; off := offset; obj0 := obj;
WHILE obj0 # bot DO obj0.type := tp; obj0.lev := 0; off := off - tp.size; obj0.val := off; obj0 := obj0.next END ;
bot := obj;
IF sym = ORS.semicolon THEN ORS.Get(sym) ELSIF sym # ORS.end THEN ORS.Mark(" ; or END") END
END ;
typ.form := ORB.Record; typ.dsc := bot; typ.size := (offset + 3) DIV 4 * 4; type := typ
END RecordType;
PROCEDURE FPSection(VAR nofpar: LONGINT);
VAR obj, first: ORB.Object; tp: ORB.Type;
cl: INTEGER; rdo: BOOLEAN;
BEGIN
IF sym = ORS.var THEN ORS.Get(sym); cl := ORB.Par ELSE cl := ORB.Var END ;
IdentList(cl, first); FormalType(tp, 0); rdo := FALSE;
IF (cl = ORB.Var) & (tp.form >= ORB.Array) THEN cl := ORB.Par; rdo := TRUE END ;
obj := first;
WHILE obj # NIL DO
INC(nofpar); obj.class := cl; obj.type := tp; obj.rdo := rdo; obj.lev := level; obj := obj.next
END ;
END FPSection;
PROCEDURE ProcedureType(ptype: ORB.Type);
VAR obj: ORB.Object; nofpar: INTEGER;
BEGIN ptype.base := ORB.noType; nofpar := 0; ptype.dsc := NIL;
IF sym = ORS.lparen THEN
ORS.Get(sym);
IF sym = ORS.rparen THEN ORS.Get(sym)
ELSE FPSection(nofpar);
WHILE sym = ORS.semicolon DO ORS.Get(sym); FPSection(nofpar) END ;
Check(ORS.rparen, "no )")
END ;
IF sym = ORS.colon THEN (*function*)
ORS.Get(sym);
IF sym = ORS.ident THEN
qualident(obj); ptype.base := obj.type;
IF ~((obj.class = ORB.Typ) & (obj.type.form IN {ORB.Byte .. ORB.Pointer, ORB.Proc})) THEN
ORS.Mark("illegal function type")
END
ELSE ORS.Mark("type identifier expected")
END
END
END ;
ptype.nofpar := nofpar
END ProcedureType;
PROCEDURE FormalType0(VAR typ: ORB.Type; dim: INTEGER);
VAR obj: ORB.Object;
BEGIN
IF sym = ORS.ident THEN
qualident(obj);
IF obj.class = ORB.Typ THEN typ := obj.type ELSE ORS.Mark("not a type"); typ := ORB.intType END
ELSIF sym = ORS.array THEN
ORS.Get(sym); Check(ORS.of, "OF ?");
IF dim >= 1 THEN ORS.Mark("multi-dimensional open arrays not implemented") END ;
NEW(typ); typ.form := ORB.Array; typ.len := -1; typ.size := 2*ORG.WordSize;
FormalType(typ.base, dim+1)
ELSIF sym = ORS.procedure THEN
ORS.Get(sym); ORB.OpenScope;
NEW(typ); typ.form := ORB.Proc; typ.size := ORG.WordSize; ProcedureType(typ);
typ.dsc := ORB.topScope.next; ORB.CloseScope
ELSE ORS.Mark("identifier expected"); typ := ORB.noType
END
END FormalType0;
PROCEDURE CheckRecLevel(lev: INTEGER);
BEGIN
IF lev # 0 THEN ORS.Mark("ptr base must be global") END
END CheckRecLevel;
PROCEDURE Type0(VAR type: ORB.Type);
VAR obj: ORB.Object; ptbase: PtrBase;
BEGIN type := ORB.intType; (*sync*)
IF (sym # ORS.ident) & (sym < ORS.array) THEN ORS.Mark("not a type");
REPEAT ORS.Get(sym) UNTIL (sym = ORS.ident) OR (sym >= ORS.array)
END ;
IF sym = ORS.ident THEN
qualident(obj);
IF obj.class = ORB.Typ THEN
IF (obj.type # NIL) & (obj.type.form # ORB.NoTyp) THEN type := obj.type END
ELSE ORS.Mark("not a type or undefined")
END
ELSIF sym = ORS.array THEN ORS.Get(sym); ArrayType(type)
ELSIF sym = ORS.record THEN
ORS.Get(sym); RecordType(type); Check(ORS.end, "no END")
ELSIF sym = ORS.pointer THEN
ORS.Get(sym); Check(ORS.to, "no TO");
NEW(type); type.form := ORB.Pointer; type.size := ORG.WordSize; type.base := ORB.intType;
IF sym = ORS.ident THEN
obj := ORB.thisObj();
IF obj # NIL THEN
IF (obj.class = ORB.Typ) & (obj.type.form IN {ORB.Record, ORB.NoTyp}) THEN
CheckRecLevel(obj.lev); type.base := obj.type
ELSIF obj.class = ORB.Mod THEN ORS.Mark("external base type not implemented")
ELSE ORS.Mark("no valid base type")
END
ELSE CheckRecLevel(level); (*enter into list of forward references to be fixed in Declarations*)
NEW(ptbase); ORS.CopyId(ptbase.name); ptbase.type := type; ptbase.next := pbsList; pbsList := ptbase
END ;
ORS.Get(sym)
ELSE Type(type.base);
IF (type.base.form # ORB.Record) OR (type.base.typobj = NIL) THEN ORS.Mark("must point to named record") END ;
CheckRecLevel(level)
END
ELSIF sym = ORS.procedure THEN
ORS.Get(sym); ORB.OpenScope;
NEW(type); type.form := ORB.Proc; type.size := ORG.WordSize;
ProcedureType(type); type.dsc := ORB.topScope.next; ORB.CloseScope
ELSE ORS.Mark("illegal type")
END
END Type0;
PROCEDURE Declarations(VAR varsize: LONGINT);
VAR obj, first: ORB.Object;
x: ORG.Item; tp: ORB.Type; ptbase: PtrBase;
expo: BOOLEAN; id: ORS.Ident;
BEGIN (*sync*) pbsList := NIL;
IF (sym < ORS.const) & (sym # ORS.end) & (sym # ORS.return) THEN ORS.Mark("declaration?");
REPEAT ORS.Get(sym) UNTIL (sym >= ORS.const) OR (sym = ORS.end) OR (sym = ORS.return)
END ;
IF sym = ORS.const THEN
ORS.Get(sym);
WHILE sym = ORS.ident DO
ORS.CopyId(id); ORS.Get(sym); CheckExport(expo);
IF sym = ORS.eql THEN ORS.Get(sym) ELSE ORS.Mark("= ?") END;
expression(x);
IF (x.type.form = ORB.String) & (x.b = 2) THEN ORG.StrToChar(x) END ;
ORB.NewObj(obj, id, ORB.Const); obj.expo := expo;
IF x.mode = ORB.Const THEN obj.val := x.a; obj.lev := x.b; obj.type := x.type
ELSE ORS.Mark("expression not constant"); obj.type := ORB.intType
END;
Check(ORS.semicolon, "; missing")
END
END ;
IF sym = ORS.type THEN
ORS.Get(sym);
WHILE sym = ORS.ident DO
ORS.CopyId(id); ORS.Get(sym); CheckExport(expo);
IF sym = ORS.eql THEN ORS.Get(sym) ELSE ORS.Mark("=?") END ;
Type(tp);
ORB.NewObj(obj, id, ORB.Typ); obj.type := tp; obj.expo := expo; obj.lev := level;
IF tp.typobj = NIL THEN tp.typobj := obj END ;
IF expo & (obj.type.form = ORB.Record) THEN obj.exno := exno; INC(exno) ELSE obj.exno := 0 END ;
IF tp.form = ORB.Record THEN
ptbase := pbsList; (*check whether this is base of a pointer type; search and fixup*)
WHILE ptbase # NIL DO
IF obj.name = ptbase.name THEN ptbase.type.base := obj.type END ;
ptbase := ptbase.next
END ;
IF level = 0 THEN ORG.BuildTD(tp, dc) END (*type descriptor; len used as its address*)
END ;
Check(ORS.semicolon, "; missing")
END
END ;
IF sym = ORS.var THEN
ORS.Get(sym);
WHILE sym = ORS.ident DO
IdentList(ORB.Var, first); Type(tp);
obj := first;
WHILE obj # NIL DO
obj.type := tp; obj.lev := level;
IF tp.size > 1 THEN varsize := (varsize + 3) DIV 4 * 4 (*align*) END ;
obj.val := varsize; varsize := varsize + obj.type.size;
IF obj.expo THEN obj.exno := exno; INC(exno) END ;
obj := obj.next
END ;
Check(ORS.semicolon, "; missing")
END
END ;
varsize := (varsize + 3) DIV 4 * 4;
ptbase := pbsList;
WHILE ptbase # NIL DO
IF ptbase.type.base.form = ORB.Int THEN ORS.Mark("undefined pointer base of") END ;
ptbase := ptbase.next
END ;
IF (sym >= ORS.const) & (sym <= ORS.var) THEN ORS.Mark("declaration in bad order") END
END Declarations;
PROCEDURE AllocProc(ptype: ORB.Type; VAR parblksize, locblksize: INTEGER; int: BOOLEAN);
CONST ParOff = 2*ORG.WordSize;
VAR obj: ORB.Object; tp: ORB.Type; par, nofpar, parsize, adr: INTEGER;
BEGIN nofpar := ptype.nofpar;
par := 0; obj := ptype.dsc; adr := ParOff;
WHILE par < nofpar DO
tp := obj.type;
IF (tp.form = ORB.Array) & (tp.len < 0) OR (tp.form = ORB.Record) THEN
parsize := 2*ORG.WordSize (* open array or record, needs second word for length or type tag *)
ELSE parsize := ORG.WordSize
END;
INC(adr, parsize); INC(par);
obj := obj.next
END;
parblksize := adr;
par := 0; obj := ptype.dsc; adr := parblksize;
WHILE par < nofpar DO (* parameters *)
tp := obj.type;
DEC(adr, ORG.WordSize); obj.val := adr;
IF (tp.form = ORB.Array) & (tp.len < 0) OR (tp.form = ORB.Record) THEN
DEC(adr, ORG.WordSize) (* open array or record, needs second word for length or type tag *)
END;
INC(par);
obj := obj.next
END;
parblksize := parblksize - ParOff; adr := 0;
WHILE obj # NIL DO (* local variables *)
IF obj.class = ORB.Var THEN
tp := obj.type;
IF tp.size > 1 THEN adr := (adr - 3) DIV 4 * 4 (*align*) END;
adr := adr - tp.size; obj.val := adr
END;
obj := obj.next
END;
locblksize := -adr
END AllocProc;
PROCEDURE ProcedureDecl;
VAR proc: ORB.Object;
type: ORB.Type;
procid: ORS.Ident;
x: ORG.Item;
locblksize, parblksize, L: LONGINT;
int: BOOLEAN;
BEGIN (* ProcedureDecl *) int := FALSE; ORS.Get(sym);
IF sym = ORS.times THEN ORS.Get(sym); int := TRUE END ;
IF sym = ORS.ident THEN
ORS.CopyId(procid); ORS.Get(sym);
ORB.NewObj(proc, ORS.id, ORB.Const);
IF int THEN parblksize := 12 ELSE parblksize := 4 END ;
NEW(type); type.form := ORB.Proc; type.size := ORG.WordSize;
proc.type := type; proc.val := -1; proc.lev := level;
CheckExport(proc.expo);
IF proc.expo THEN proc.exno := exno; INC(exno) END ;
ORB.OpenScope; INC(level); type.base := ORB.noType;
ProcedureType(type); (*formal parameter list*)
Check(ORS.semicolon, "no ;"); locblksize := 0;
Declarations(locblksize);
proc.val := ORG.Here(); proc.type.dsc := ORB.topScope.next;
AllocProc(type, parblksize, locblksize, int);
IF sym = ORS.procedure THEN
L := 0; ORG.FJump(L);
REPEAT ProcedureDecl; Check(ORS.semicolon, "no ;") UNTIL sym # ORS.procedure;
ORG.FixOne(L); proc.val := ORG.Here(); proc.type.dsc := ORB.topScope.next
END ;
ORG.Enter(parblksize, locblksize, int);
IF sym = ORS.begin THEN ORS.Get(sym); StatSequence END ;
IF sym = ORS.return THEN
ORS.Get(sym); expression(x);
IF type.base = ORB.noType THEN ORS.Mark("this is not a function")
ELSIF ~CompTypes(type.base, x.type, FALSE) THEN ORS.Mark("wrong result type")
END
ELSIF type.base.form # ORB.NoTyp THEN
ORS.Mark("function without result"); type.base := ORB.noType
END ;
ORG.Return(type.base.form, x, locblksize, int);
ORB.CloseScope; DEC(level); Check(ORS.end, "no END");
IF sym = ORS.ident THEN
IF ORS.id # procid THEN ORS.Mark("no match") END ;
ORS.Get(sym)
ELSE ORS.Mark("no proc id")
END
ELSE ORS.Mark("proc id expected")
END
END ProcedureDecl;
PROCEDURE Import;
VAR impid, impid1: ORS.Ident;
BEGIN
IF sym = ORS.ident THEN
ORS.CopyId(impid); ORS.Get(sym);
IF sym = ORS.becomes THEN
ORS.Get(sym);
IF sym = ORS.ident THEN ORS.CopyId(impid1); ORS.Get(sym)
ELSE ORS.Mark("id expected"); impid1 := impid
END
ELSE impid1 := impid
END ;
ORB.Import(impid, impid1)
ELSE ORS.Mark("id expected")
END
END Import;
PROCEDURE Module;
VAR key: LONGINT;
BEGIN Texts.WriteString(W, " compiling "); ORS.Get(sym);
IF sym = ORS.module THEN
ORS.Get(sym);
IF sym = ORS.times THEN version := 0; dc := 8; Texts.Write(W, "*"); ORS.Get(sym) ELSE dc := 0; version := 1 END ;
ORB.Init; ORB.OpenScope;
IF sym = ORS.ident THEN
ORS.CopyId(modid); ORS.Get(sym);
Texts.WriteString(W, modid); Texts.Append(Oberon.Log, W.buf)
ELSE ORS.Mark("identifier expected")
END ;
Check(ORS.semicolon, "no ;"); level := 0; exno := 1; key := 0;
IF sym = ORS.import THEN
ORS.Get(sym); Import;
WHILE sym = ORS.comma DO ORS.Get(sym); Import END ;
Check(ORS.semicolon, "; missing")
END ;
ORG.Open(version); Declarations(dc); ORG.SetDataSize((dc + 3) DIV 4 * 4);
WHILE sym = ORS.procedure DO ProcedureDecl; Check(ORS.semicolon, "no ;") END ;
ORG.Header;
IF sym = ORS.begin THEN ORS.Get(sym); StatSequence END ;
Check(ORS.end, "no END");
IF sym = ORS.ident THEN
IF ORS.id # modid THEN ORS.Mark("no match") END ;
ORS.Get(sym)
ELSE ORS.Mark("identifier missing")
END ;
IF sym # ORS.period THEN ORS.Mark("period missing") END ;
IF (ORS.errcnt = 0) & (version # 0) THEN
ORB.Export(modid, newSF, key);
IF newSF THEN Texts.WriteString(W, " new symbol file") END
END ;
IF ORS.errcnt = 0 THEN
ORG.Close(modid, key, exno);
Texts.WriteInt(W, ORG.pc, 6); Texts.WriteInt(W, dc, 6); Texts.WriteHex(W, key)
ELSE Texts.WriteLn(W); Texts.WriteString(W, "compilation FAILED")
END ;
Texts.WriteLn(W); Texts.Append(Oberon.Log, W.buf);
ORB.CloseScope; pbsList := NIL
ELSE ORS.Mark("must start with MODULE")
END
END Module;
PROCEDURE Option(VAR S: Texts.Scanner);
BEGIN newSF := FALSE;
IF S.nextCh = "/" THEN
Texts.Scan(S); Texts.Scan(S);
IF (S.class = Texts.Name) & (S.s[0] = "s") THEN newSF := TRUE END
END
END Option;
PROCEDURE Compile*;
VAR beg, end, time: LONGINT;
T: Texts.Text;
S: Texts.Scanner;