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
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
|
/* $NetBSD: func.c,v 1.22 2005/09/24 15:30:35 perry Exp $ */
/*
* Copyright (c) 1994, 1995 Jochen Pohl
* All Rights Reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by Jochen Pohl for
* The NetBSD Project.
* 4. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <sys/cdefs.h>
#if defined(__RCSID) && !defined(lint)
__RCSID("$NetBSD: func.c,v 1.16 2002/01/03 04:25:15 thorpej Exp $");
#endif
__FBSDID("$FreeBSD$");
#include <stdlib.h>
#include <string.h>
#include "lint1.h"
#include "cgram.h"
/*
* Contains a pointer to the symbol table entry of the current function
* definition.
*/
sym_t *funcsym;
/* Is set as long as a statement can be reached. Must be set at level 0. */
int reached = 1;
/*
* Is set as long as NOTREACHED is in effect.
* Is reset everywhere where reached can become 0.
*/
int rchflg;
/*
* In conjunction with reached controls printing of "fallthrough on ..."
* warnings.
* Reset by each statement and set by FALLTHROUGH, switch (switch1())
* and case (label()).
*
* Control statements if, for, while and switch do not reset ftflg because
* this must be done by the controlled statement. At least for if this is
* important because ** FALLTHROUGH ** after "if (expr) stmnt" is evaluated
* before the following token, which causes reduction of above, is read.
* This means that ** FALLTHROUGH ** after "if ..." would always be ignored.
*/
int ftflg;
/* Top element of stack for control statements */
cstk_t *cstk;
/*
* Number of arguments which will be checked for usage in following
* function definition. -1 stands for all arguments.
*
* The position of the last ARGSUSED comment is stored in aupos.
*/
int nargusg = -1;
pos_t aupos;
/*
* Number of arguments of the following function definition whose types
* shall be checked by lint2. -1 stands for all arguments.
*
* The position of the last VARARGS comment is stored in vapos.
*/
int nvararg = -1;
pos_t vapos;
/*
* Both prflstr and scflstrg contain the number of the argument which
* shall be used to check the types of remaining arguments (for PRINTFLIKE
* and SCANFLIKE).
*
* prflpos and scflpos are the positions of the last PRINTFLIKE or
* SCANFLIKE comment.
*/
int prflstrg = -1;
int scflstrg = -1;
pos_t prflpos;
pos_t scflpos;
/*
* Are both plibflg and llibflg set, prototypes are written as function
* definitions to the output file.
*/
int plibflg;
/*
* Nonzero means that no warnings about constants in conditional
* context are printed.
*/
int ccflg;
/*
* llibflg is set if a lint library shall be created. The effect of
* llibflg is that all defined symbols are treated as used.
* (The LINTLIBRARY comment also resets vflag.)
*/
int llibflg;
/*
* Nonzero if warnings are suppressed by a LINTED directive
*/
int nowarn;
/*
* Nonzero if bitfield type errors are suppressed by a BITFIELDTYPE
* directive.
*/
int bitfieldtype_ok;
/*
* Nonzero if complaints about use of "long long" are suppressed in
* the next statement or declaration.
*/
int quadflg;
/*
* Puts a new element at the top of the stack used for control statements.
*/
void
pushctrl(int env)
{
cstk_t *ci;
if ((ci = calloc(1, sizeof (cstk_t))) == NULL)
nomem();
ci->c_env = env;
ci->c_nxt = cstk;
cstk = ci;
}
/*
* Removes the top element of the stack used for control statements.
*/
void
popctrl(int env)
{
cstk_t *ci;
clst_t *cl;
if (cstk == NULL || cstk->c_env != env)
LERROR("popctrl()");
cstk = (ci = cstk)->c_nxt;
while ((cl = ci->c_clst) != NULL) {
ci->c_clst = cl->cl_nxt;
free(cl);
}
if (ci->c_swtype != NULL)
free(ci->c_swtype);
free(ci);
}
/*
* Prints a warning if a statement cannot be reached.
*/
void
chkreach(void)
{
if (!reached && !rchflg) {
/* statement not reached */
warning(193);
reached = 1;
}
}
/*
* Called after a function declaration which introduces a function definition
* and before an (optional) old style argument declaration list.
*
* Puts all symbols declared in the Prototype or in an old style argument
* list back to the symbol table.
*
* Does the usual checking of storage class, type (return value),
* redeclaration etc..
*/
void
funcdef(sym_t *fsym)
{
int n, warn;
sym_t *arg, *sym, *rdsym;
funcsym = fsym;
/*
* Put all symbols declared in the argument list back to the
* symbol table.
*/
for (sym = dcs->d_fpsyms; sym != NULL; sym = sym->s_dlnxt) {
if (sym->s_blklev != -1) {
if (sym->s_blklev != 1)
LERROR("funcdef()");
inssym(1, sym);
}
}
/*
* In osfunc() we did not know whether it is an old style function
* definition or only an old style declaration, if there are no
* arguments inside the argument list ("f()").
*/
if (!fsym->s_type->t_proto && fsym->s_args == NULL)
fsym->s_osdef = 1;
chktyp(fsym);
/*
* chktyp() checks for almost all possible errors, but not for
* incomplete return values (these are allowed in declarations)
*/
if (fsym->s_type->t_subt->t_tspec != VOID &&
incompl(fsym->s_type->t_subt)) {
/* cannot return incomplete type */
error(67);
}
fsym->s_def = DEF;
if (fsym->s_scl == TYPEDEF) {
fsym->s_scl = EXTERN;
/* illegal storage class */
error(8);
}
if (dcs->d_inline)
fsym->s_inline = 1;
/*
* Arguments in new style function declarations need a name.
* (void is already removed from the list of arguments)
*/
n = 1;
for (arg = fsym->s_type->t_args; arg != NULL; arg = arg->s_nxt) {
if (arg->s_scl == ABSTRACT) {
if (arg->s_name != unnamed)
LERROR("funcdef()");
/* formal parameter lacks name: param #%d */
error(59, n);
} else {
if (arg->s_name == unnamed)
LERROR("funcdef()");
}
n++;
}
/*
* We must also remember the position. s_dpos is overwritten
* if this is an old style definition and we had already a
* prototype.
*/
STRUCT_ASSIGN(dcs->d_fdpos, fsym->s_dpos);
if ((rdsym = dcs->d_rdcsym) != NULL) {
if (!isredec(fsym, (warn = 0, &warn))) {
/*
* Print nothing if the newly defined function
* is defined in old style. A better warning will
* be printed in cluparg().
*/
if (warn && !fsym->s_osdef) {
/* redeclaration of %s */
(*(sflag ? error : warning))(27, fsym->s_name);
prevdecl(-1, rdsym);
}
/* copy usage information */
cpuinfo(fsym, rdsym);
/*
* If the old symbol was a prototype and the new
* one is none, overtake the position of the
* declaration of the prototype.
*/
if (fsym->s_osdef && rdsym->s_type->t_proto)
STRUCT_ASSIGN(fsym->s_dpos, rdsym->s_dpos);
/* complete the type */
compltyp(fsym, rdsym);
/* once a function is inline it remains inline */
if (rdsym->s_inline)
fsym->s_inline = 1;
}
/* remove the old symbol from the symbol table */
rmsym(rdsym);
}
if (fsym->s_osdef && !fsym->s_type->t_proto) {
if (sflag && hflag && strcmp(fsym->s_name, "main") != 0)
/* function definition is not a prototype */
warning(286);
}
if (dcs->d_notyp)
/* return value is implicitly declared to be int */
fsym->s_rimpl = 1;
reached = 1;
}
/*
* Called at the end of a function definition.
*/
void
funcend(void)
{
sym_t *arg;
int n;
if (reached) {
cstk->c_noretval = 1;
if (funcsym->s_type->t_subt->t_tspec != VOID &&
!funcsym->s_rimpl) {
/* func. %s falls off bottom without returning value */
warning(217, funcsym->s_name);
}
}
/*
* This warning is printed only if the return value was implicitly
* declared to be int. Otherwise the wrong return statement
* has already printed a warning.
*/
if (cstk->c_noretval && cstk->c_retval && funcsym->s_rimpl)
/* function %s has return (e); and return; */
warning(216, funcsym->s_name);
/* Print warnings for unused arguments */
arg = dcs->d_fargs;
n = 0;
while (arg != NULL && (nargusg == -1 || n < nargusg)) {
chkusg1(dcs->d_asm, arg);
arg = arg->s_nxt;
n++;
}
nargusg = -1;
/*
* write the information about the function definition to the
* output file
* inline functions explicitly declared extern are written as
* declarations only.
*/
if (dcs->d_scl == EXTERN && funcsym->s_inline) {
outsym(funcsym, funcsym->s_scl, DECL);
} else {
outfdef(funcsym, &dcs->d_fdpos, cstk->c_retval,
funcsym->s_osdef, dcs->d_fargs);
}
/*
* remove all symbols declared during argument declaration from
* the symbol table
*/
if (dcs->d_nxt != NULL || dcs->d_ctx != EXTERN)
LERROR("funcend()");
rmsyms(dcs->d_fpsyms);
/* must be set on level 0 */
reached = 1;
}
/*
* Process a label.
*
* typ type of the label (T_NAME, T_DEFAULT or T_CASE).
* sym symbol table entry of label if typ == T_NAME
* tn expression if typ == T_CASE
*/
void
label(int typ, sym_t *sym, tnode_t *tn)
{
cstk_t *ci;
clst_t *cl;
val_t *v;
val_t nv;
tspec_t t;
switch (typ) {
case T_NAME:
if (sym->s_set) {
/* label %s redefined */
error(194, sym->s_name);
} else {
setsflg(sym);
}
break;
case T_CASE:
/* find the stack entry for the innermost switch statement */
for (ci = cstk; ci != NULL && !ci->c_switch; ci = ci->c_nxt)
continue;
if (ci == NULL) {
/* case not in switch */
error(195);
tn = NULL;
} else if (tn != NULL && tn->tn_op != CON) {
/* non-constant case expression */
error(197);
tn = NULL;
} else if (tn != NULL && !isityp(tn->tn_type->t_tspec)) {
/* non-integral case expression */
error(198);
tn = NULL;
}
if (tn != NULL) {
if (ci->c_swtype == NULL)
LERROR("label()");
if (reached && !ftflg) {
if (hflag)
/* fallthrough on case statement */
warning(220);
}
t = tn->tn_type->t_tspec;
if (t == LONG || t == ULONG ||
t == QUAD || t == UQUAD) {
if (tflag)
/* case label must be of type ... */
warning(203);
}
/*
* get the value of the expression and convert it
* to the type of the switch expression
*/
v = constant(tn, 1);
(void) memset(&nv, 0, sizeof nv);
cvtcon(CASE, 0, ci->c_swtype, &nv, v);
free(v);
/* look if we had this value already */
for (cl = ci->c_clst; cl != NULL; cl = cl->cl_nxt) {
if (cl->cl_val.v_quad == nv.v_quad)
break;
}
if (cl != NULL && isutyp(nv.v_tspec)) {
/* duplicate case in switch, %lu */
error(200, (u_long)nv.v_quad);
} else if (cl != NULL) {
/* duplicate case in switch, %ld */
error(199, (long)nv.v_quad);
} else {
/*
* append the value to the list of
* case values
*/
cl = xcalloc(1, sizeof (clst_t));
STRUCT_ASSIGN(cl->cl_val, nv);
cl->cl_nxt = ci->c_clst;
ci->c_clst = cl;
}
}
tfreeblk();
break;
case T_DEFAULT:
/* find the stack entry for the innermost switch statement */
for (ci = cstk; ci != NULL && !ci->c_switch; ci = ci->c_nxt)
continue;
if (ci == NULL) {
/* default outside switch */
error(201);
} else if (ci->c_default) {
/* duplicate default in switch */
error(202);
} else {
if (reached && !ftflg) {
if (hflag)
/* fallthrough on default statement */
warning(284);
}
ci->c_default = 1;
}
break;
};
reached = 1;
}
/*
* T_IF T_LPARN expr T_RPARN
*/
void
if1(tnode_t *tn)
{
if (tn != NULL)
tn = cconv(tn);
if (tn != NULL)
tn = promote(NOOP, 0, tn);
expr(tn, 0, 1, 1);
pushctrl(T_IF);
}
/*
* if_without_else
* if_without_else T_ELSE
*/
void
if2(void)
{
cstk->c_rchif = reached ? 1 : 0;
reached = 1;
}
/*
* if_without_else
* if_without_else T_ELSE stmnt
*/
void
if3(int els)
{
if (els) {
reached |= cstk->c_rchif;
} else {
reached = 1;
}
popctrl(T_IF);
}
/*
* T_SWITCH T_LPARN expr T_RPARN
*/
void
switch1(tnode_t *tn)
{
tspec_t t;
type_t *tp;
if (tn != NULL)
tn = cconv(tn);
if (tn != NULL)
tn = promote(NOOP, 0, tn);
if (tn != NULL && !isityp(tn->tn_type->t_tspec)) {
/* switch expression must have integral type */
error(205);
tn = NULL;
}
if (tn != NULL && tflag) {
t = tn->tn_type->t_tspec;
if (t == LONG || t == ULONG || t == QUAD || t == UQUAD) {
/* switch expr. must be of type `int' in trad. C */
warning(271);
}
}
/*
* Remember the type of the expression. Because its possible
* that (*tp) is allocated on tree memory the type must be
* duplicated. This is not too complicated because it is
* only an integer type.
*/
if ((tp = calloc(1, sizeof (type_t))) == NULL)
nomem();
if (tn != NULL) {
tp->t_tspec = tn->tn_type->t_tspec;
if ((tp->t_isenum = tn->tn_type->t_isenum) != 0)
tp->t_enum = tn->tn_type->t_enum;
} else {
tp->t_tspec = INT;
}
expr(tn, 1, 0, 1);
pushctrl(T_SWITCH);
cstk->c_switch = 1;
cstk->c_swtype = tp;
reached = rchflg = 0;
ftflg = 1;
}
/*
* switch_expr stmnt
*/
void
switch2(void)
{
int nenum = 0, nclab = 0;
sym_t *esym;
clst_t *cl;
if (cstk->c_swtype == NULL)
LERROR("switch2()");
/*
* If the switch expression was of type enumeration, count the case
* labels and the number of enumerators. If both counts are not
* equal print a warning.
*/
if (cstk->c_swtype->t_isenum) {
nenum = nclab = 0;
if (cstk->c_swtype->t_enum == NULL)
LERROR("switch2()");
for (esym = cstk->c_swtype->t_enum->elem;
esym != NULL; esym = esym->s_nxt) {
nenum++;
}
for (cl = cstk->c_clst; cl != NULL; cl = cl->cl_nxt)
nclab++;
if (hflag && eflag && nenum != nclab && !cstk->c_default) {
/* enumeration value(s) not handled in switch */
warning(206);
}
}
if (cstk->c_break) {
/*
* end of switch alway reached (c_break is only set if the
* break statement can be reached).
*/
reached = 1;
} else if (!cstk->c_default &&
(!hflag || !cstk->c_swtype->t_isenum || nenum != nclab)) {
/*
* there are possible values which are not handled in
* switch
*/
reached = 1;
} /*
* otherwise the end of the switch expression is reached
* if the end of the last statement inside it is reached.
*/
popctrl(T_SWITCH);
}
/*
* T_WHILE T_LPARN expr T_RPARN
*/
void
while1(tnode_t *tn)
{
if (!reached) {
/* loop not entered at top */
warning(207);
reached = 1;
}
if (tn != NULL)
tn = cconv(tn);
if (tn != NULL)
tn = promote(NOOP, 0, tn);
if (tn != NULL && !issclt(tn->tn_type->t_tspec)) {
/* controlling expressions must have scalar type */
error(204);
tn = NULL;
}
pushctrl(T_WHILE);
cstk->c_loop = 1;
if (tn != NULL && tn->tn_op == CON) {
if (isityp(tn->tn_type->t_tspec)) {
cstk->c_infinite = tn->tn_val->v_quad != 0;
} else {
cstk->c_infinite = tn->tn_val->v_ldbl != 0.0;
}
}
expr(tn, 0, 1, 1);
}
/*
* while_expr stmnt
* while_expr error
*/
void
while2(void)
{
/*
* The end of the loop can be reached if it is no endless loop
* or there was a break statement which was reached.
*/
reached = !cstk->c_infinite || cstk->c_break;
rchflg = 0;
popctrl(T_WHILE);
}
/*
* T_DO
*/
void
do1(void)
{
if (!reached) {
/* loop not entered at top */
warning(207);
reached = 1;
}
pushctrl(T_DO);
cstk->c_loop = 1;
}
/*
* do stmnt do_while_expr
* do error
*/
void
do2(tnode_t *tn)
{
/*
* If there was a continue statement the expression controlling the
* loop is reached.
*/
if (cstk->c_cont)
reached = 1;
if (tn != NULL)
tn = cconv(tn);
if (tn != NULL)
tn = promote(NOOP, 0, tn);
if (tn != NULL && !issclt(tn->tn_type->t_tspec)) {
/* controlling expressions must have scalar type */
error(204);
tn = NULL;
}
if (tn != NULL && tn->tn_op == CON) {
if (isityp(tn->tn_type->t_tspec)) {
cstk->c_infinite = tn->tn_val->v_quad != 0;
} else {
cstk->c_infinite = tn->tn_val->v_ldbl != 0.0;
}
}
expr(tn, 0, 1, 1);
/*
* The end of the loop is only reached if it is no endless loop
* or there was a break statement which could be reached.
*/
reached = !cstk->c_infinite || cstk->c_break;
rchflg = 0;
popctrl(T_DO);
}
/*
* T_FOR T_LPARN opt_expr T_SEMI opt_expr T_SEMI opt_expr T_RPARN
*/
void
for1(tnode_t *tn1, tnode_t *tn2, tnode_t *tn3)
{
/*
* If there is no initialisation expression it is possible that
* it is intended not to enter the loop at top.
*/
if (tn1 != NULL && !reached) {
/* loop not entered at top */
warning(207);
reached = 1;
}
pushctrl(T_FOR);
cstk->c_loop = 1;
/*
* Store the tree memory for the reinitialisation expression.
* Also remember this expression itself. We must check it at
* the end of the loop to get "used but not set" warnings correct.
*/
cstk->c_fexprm = tsave();
cstk->c_f3expr = tn3;
STRUCT_ASSIGN(cstk->c_fpos, curr_pos);
STRUCT_ASSIGN(cstk->c_cfpos, csrc_pos);
if (tn1 != NULL)
expr(tn1, 0, 0, 1);
if (tn2 != NULL)
tn2 = cconv(tn2);
if (tn2 != NULL)
tn2 = promote(NOOP, 0, tn2);
if (tn2 != NULL && !issclt(tn2->tn_type->t_tspec)) {
/* controlling expressions must have scalar type */
error(204);
tn2 = NULL;
}
if (tn2 != NULL)
expr(tn2, 0, 1, 1);
if (tn2 == NULL) {
cstk->c_infinite = 1;
} else if (tn2->tn_op == CON) {
if (isityp(tn2->tn_type->t_tspec)) {
cstk->c_infinite = tn2->tn_val->v_quad != 0;
} else {
cstk->c_infinite = tn2->tn_val->v_ldbl != 0.0;
}
}
/* Checking the reinitialisation expression is done in for2() */
reached = 1;
}
/*
* for_exprs stmnt
* for_exprs error
*/
void
for2(void)
{
pos_t cpos, cspos;
tnode_t *tn3;
if (cstk->c_cont)
reached = 1;
STRUCT_ASSIGN(cpos, curr_pos);
STRUCT_ASSIGN(cspos, csrc_pos);
/* Restore the tree memory for the reinitialisation expression */
trestor(cstk->c_fexprm);
tn3 = cstk->c_f3expr;
STRUCT_ASSIGN(curr_pos, cstk->c_fpos);
STRUCT_ASSIGN(csrc_pos, cstk->c_cfpos);
/* simply "statement not reached" would be confusing */
if (!reached && !rchflg) {
/* end-of-loop code not reached */
warning(223);
reached = 1;
}
if (tn3 != NULL) {
expr(tn3, 0, 0, 1);
} else {
tfreeblk();
}
STRUCT_ASSIGN(curr_pos, cpos);
STRUCT_ASSIGN(csrc_pos, cspos);
/* An endless loop without break will never terminate */
reached = cstk->c_break || !cstk->c_infinite;
rchflg = 0;
popctrl(T_FOR);
}
/*
* T_GOTO identifier T_SEMI
* T_GOTO error T_SEMI
*/
void
dogoto(sym_t *lab)
{
setuflg(lab, 0, 0);
chkreach();
reached = rchflg = 0;
}
/*
* T_BREAK T_SEMI
*/
void
dobreak(void)
{
cstk_t *ci;
ci = cstk;
while (ci != NULL && !ci->c_loop && !ci->c_switch)
ci = ci->c_nxt;
if (ci == NULL) {
/* break outside loop or switch */
error(208);
} else {
if (reached)
ci->c_break = 1;
}
if (bflag)
chkreach();
reached = rchflg = 0;
}
/*
* T_CONTINUE T_SEMI
*/
void
docont(void)
{
cstk_t *ci;
for (ci = cstk; ci != NULL && !ci->c_loop; ci = ci->c_nxt)
continue;
if (ci == NULL) {
/* continue outside loop */
error(209);
} else {
ci->c_cont = 1;
}
chkreach();
reached = rchflg = 0;
}
/*
* T_RETURN T_SEMI
* T_RETURN expr T_SEMI
*/
void
doreturn(tnode_t *tn)
{
tnode_t *ln, *rn;
cstk_t *ci;
op_t op;
for (ci = cstk; ci->c_nxt != NULL; ci = ci->c_nxt)
continue;
if (tn != NULL) {
ci->c_retval = 1;
} else {
ci->c_noretval = 1;
}
if (tn != NULL && funcsym->s_type->t_subt->t_tspec == VOID) {
/* void function %s cannot return value */
error(213, funcsym->s_name);
tfreeblk();
tn = NULL;
} else if (tn == NULL && funcsym->s_type->t_subt->t_tspec != VOID) {
/*
* Assume that the function has a return value only if it
* is explicitly declared.
*/
if (!funcsym->s_rimpl)
/* function %s expects to return value */
warning(214, funcsym->s_name);
}
if (tn != NULL) {
/* Create a temporary node for the left side */
ln = tgetblk(sizeof (tnode_t));
ln->tn_op = NAME;
ln->tn_type = tduptyp(funcsym->s_type->t_subt);
ln->tn_type->t_const = 0;
ln->tn_lvalue = 1;
ln->tn_sym = funcsym; /* better than nothing */
tn = build(RETURN, ln, tn);
if (tn != NULL) {
rn = tn->tn_right;
while ((op = rn->tn_op) == CVT || op == PLUS)
rn = rn->tn_left;
if (rn->tn_op == AMPER && rn->tn_left->tn_op == NAME &&
rn->tn_left->tn_sym->s_scl == AUTO) {
/* %s returns pointer to automatic object */
warning(302, funcsym->s_name);
}
}
expr(tn, 1, 0, 1);
} else {
chkreach();
}
reached = rchflg = 0;
}
/*
* Do some cleanup after a global declaration or definition.
* Especially remove informations about unused lint comments.
*/
void
glclup(int silent)
{
pos_t cpos;
STRUCT_ASSIGN(cpos, curr_pos);
if (nargusg != -1) {
if (!silent) {
STRUCT_ASSIGN(curr_pos, aupos);
/* must precede function definition: %s */
warning(282, "ARGSUSED");
}
nargusg = -1;
}
if (nvararg != -1) {
if (!silent) {
STRUCT_ASSIGN(curr_pos, vapos);
/* must precede function definition: %s */
warning(282, "VARARGS");
}
nvararg = -1;
}
if (prflstrg != -1) {
if (!silent) {
STRUCT_ASSIGN(curr_pos, prflpos);
/* must precede function definition: %s */
warning(282, "PRINTFLIKE");
}
prflstrg = -1;
}
if (scflstrg != -1) {
if (!silent) {
STRUCT_ASSIGN(curr_pos, scflpos);
/* must precede function definition: %s */
warning(282, "SCANFLIKE");
}
scflstrg = -1;
}
STRUCT_ASSIGN(curr_pos, cpos);
dcs->d_asm = 0;
}
/*
* ARGSUSED comment
*
* Only the first n arguments of the following function are checked
* for usage. A missing argument is taken to be 0.
*/
void
argsused(int n)
{
if (n == -1)
n = 0;
if (dcs->d_ctx != EXTERN) {
/* must be outside function: ** %s ** */
warning(280, "ARGSUSED");
return;
}
if (nargusg != -1) {
/* duplicate use of ** %s ** */
warning(281, "ARGSUSED");
}
nargusg = n;
STRUCT_ASSIGN(aupos, curr_pos);
}
/*
* VARARGS comment
*
* Makes that lint2 checks only the first n arguments for compatibility
* to the function definition. A missing argument is taken to be 0.
*/
void
varargs(int n)
{
if (n == -1)
n = 0;
if (dcs->d_ctx != EXTERN) {
/* must be outside function: ** %s ** */
warning(280, "VARARGS");
return;
}
if (nvararg != -1) {
/* duplicate use of ** %s ** */
warning(281, "VARARGS");
}
nvararg = n;
STRUCT_ASSIGN(vapos, curr_pos);
}
/*
* PRINTFLIKE comment
*
* Check all arguments until the (n-1)-th as usual. The n-th argument is
* used the check the types of remaining arguments.
*/
void
printflike(int n)
{
if (n == -1)
n = 0;
if (dcs->d_ctx != EXTERN) {
/* must be outside function: ** %s ** */
warning(280, "PRINTFLIKE");
return;
}
if (prflstrg != -1) {
/* duplicate use of ** %s ** */
warning(281, "PRINTFLIKE");
}
prflstrg = n;
STRUCT_ASSIGN(prflpos, curr_pos);
}
/*
* SCANFLIKE comment
*
* Check all arguments until the (n-1)-th as usual. The n-th argument is
* used the check the types of remaining arguments.
*/
void
scanflike(int n)
{
if (n == -1)
n = 0;
if (dcs->d_ctx != EXTERN) {
/* must be outside function: ** %s ** */
warning(280, "SCANFLIKE");
return;
}
if (scflstrg != -1) {
/* duplicate use of ** %s ** */
warning(281, "SCANFLIKE");
}
scflstrg = n;
STRUCT_ASSIGN(scflpos, curr_pos);
}
/*
* Set the linenumber for a CONSTCOND comment. At this and the following
* line no warnings about constants in conditional contexts are printed.
*/
/* ARGSUSED */
void
constcond(int n)
{
ccflg = 1;
}
/*
* Suppress printing of "fallthrough on ..." warnings until next
* statement.
*/
/* ARGSUSED */
void
fallthru(int n)
{
ftflg = 1;
}
/*
* Stop warnings about statements which cannot be reached. Also tells lint
* that the following statements cannot be reached (e.g. after exit()).
*/
/* ARGSUSED */
void
notreach(int n)
{
reached = 0;
rchflg = 1;
}
/* ARGSUSED */
void
lintlib(int n)
{
if (dcs->d_ctx != EXTERN) {
/* must be outside function: ** %s ** */
warning(280, "LINTLIBRARY");
return;
}
llibflg = 1;
vflag = 0;
}
/*
* Suppress most warnings at the current and the following line.
*/
/* ARGSUSED */
void
linted(int n)
{
#ifdef DEBUG
printf("%s, %d: nowarn = 1\n", curr_pos.p_file, curr_pos.p_line);
#endif
nowarn = 1;
}
/*
* Suppress bitfield type errors on the current line.
*/
/* ARGSUSED */
void
bitfieldtype(int n)
{
#ifdef DEBUG
printf("%s, %d: bitfieldtype_ok = 1\n", curr_pos.p_file,
curr_pos.p_line);
#endif
bitfieldtype_ok = 1;
}
/*
* PROTOTLIB in conjunction with LINTLIBRARY can be used to handle
* prototypes like function definitions. This is done if the argument
* to PROTOLIB is nonzero. Otherwise prototypes are handled normaly.
*/
void
protolib(int n)
{
if (dcs->d_ctx != EXTERN) {
/* must be outside function: ** %s ** */
warning(280, "PROTOLIB");
return;
}
plibflg = n == 0 ? 0 : 1;
}
/*
* Set quadflg to nonzero which means that the next statement/declaration
* may use "long long" without an error or warning.
*/
/* ARGSUSED */
void
longlong(int n)
{
quadflg = 1;
}
|