forked from sqlite/sqlite
-
Notifications
You must be signed in to change notification settings - Fork 0
Expand file tree
/
Copy pathexpr.c
More file actions
7157 lines (6865 loc) · 243 KB
/
expr.c
File metadata and controls
7157 lines (6865 loc) · 243 KB
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
/*
** 2001 September 15
**
** The author disclaims copyright to this source code. In place of
** a legal notice, here is a blessing:
**
** May you do good and not evil.
** May you find forgiveness for yourself and forgive others.
** May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains routines used for analyzing expressions and
** for generating VDBE code that evaluates expressions in SQLite.
*/
#include "sqliteInt.h"
/* Forward declarations */
static void exprCodeBetween(Parse*,Expr*,int,void(*)(Parse*,Expr*,int,int),int);
static int exprCodeVector(Parse *pParse, Expr *p, int *piToFree);
/*
** Return the affinity character for a single column of a table.
*/
char sqlite3TableColumnAffinity(const Table *pTab, int iCol){
if( iCol<0 || NEVER(iCol>=pTab->nCol) ) return SQLITE_AFF_INTEGER;
return pTab->aCol[iCol].affinity;
}
/*
** Return the 'affinity' of the expression pExpr if any.
**
** If pExpr is a column, a reference to a column via an 'AS' alias,
** or a sub-select with a column as the return value, then the
** affinity of that column is returned. Otherwise, 0x00 is returned,
** indicating no affinity for the expression.
**
** i.e. the WHERE clause expressions in the following statements all
** have an affinity:
**
** CREATE TABLE t1(a);
** SELECT * FROM t1 WHERE a;
** SELECT a AS b FROM t1 WHERE b;
** SELECT * FROM t1 WHERE (select a from t1);
*/
char sqlite3ExprAffinity(const Expr *pExpr){
int op;
op = pExpr->op;
while( 1 /* exit-by-break */ ){
if( op==TK_COLUMN || (op==TK_AGG_COLUMN && pExpr->y.pTab!=0) ){
assert( ExprUseYTab(pExpr) );
assert( pExpr->y.pTab!=0 );
return sqlite3TableColumnAffinity(pExpr->y.pTab, pExpr->iColumn);
}
if( op==TK_SELECT ){
assert( ExprUseXSelect(pExpr) );
assert( pExpr->x.pSelect!=0 );
assert( pExpr->x.pSelect->pEList!=0 );
assert( pExpr->x.pSelect->pEList->a[0].pExpr!=0 );
return sqlite3ExprAffinity(pExpr->x.pSelect->pEList->a[0].pExpr);
}
#ifndef SQLITE_OMIT_CAST
if( op==TK_CAST ){
assert( !ExprHasProperty(pExpr, EP_IntValue) );
return sqlite3AffinityType(pExpr->u.zToken, 0);
}
#endif
if( op==TK_SELECT_COLUMN ){
assert( pExpr->pLeft!=0 && ExprUseXSelect(pExpr->pLeft) );
assert( pExpr->iColumn < pExpr->iTable );
assert( pExpr->iColumn >= 0 );
assert( pExpr->iTable==pExpr->pLeft->x.pSelect->pEList->nExpr );
return sqlite3ExprAffinity(
pExpr->pLeft->x.pSelect->pEList->a[pExpr->iColumn].pExpr
);
}
if( op==TK_VECTOR ){
assert( ExprUseXList(pExpr) );
return sqlite3ExprAffinity(pExpr->x.pList->a[0].pExpr);
}
if( ExprHasProperty(pExpr, EP_Skip|EP_IfNullRow) ){
assert( pExpr->op==TK_COLLATE
|| pExpr->op==TK_IF_NULL_ROW
|| (pExpr->op==TK_REGISTER && pExpr->op2==TK_IF_NULL_ROW) );
pExpr = pExpr->pLeft;
op = pExpr->op;
continue;
}
if( op!=TK_REGISTER ) break;
op = pExpr->op2;
if( NEVER( op==TK_REGISTER ) ) break;
}
return pExpr->affExpr;
}
/*
** Make a guess at all the possible datatypes of the result that could
** be returned by an expression. Return a bitmask indicating the answer:
**
** 0x01 Numeric
** 0x02 Text
** 0x04 Blob
**
** If the expression must return NULL, then
4D1C
0x00 is returned.
*/
int sqlite3ExprDataType(const Expr *pExpr){
while( pExpr ){
switch( pExpr->op ){
case TK_COLLATE:
case TK_IF_NULL_ROW:
case TK_UPLUS: {
pExpr = pExpr->pLeft;
break;
}
case TK_NULL: {
pExpr = 0;
break;
}
case TK_STRING: {
return 0x02;
}
case TK_BLOB: {
return 0x04;
}
case TK_CONCAT: {
return 0x06;
}
case TK_VARIABLE:
case TK_AGG_FUNCTION:
case TK_FUNCTION: {
return 0x07;
}
case TK_COLUMN:
case TK_AGG_COLUMN:
case TK_SELECT:
case TK_CAST:
case TK_SELECT_COLUMN:
case TK_VECTOR: {
int aff = sqlite3ExprAffinity(pExpr);
if( aff>=SQLITE_AFF_NUMERIC ) return 0x05;
if( aff==SQLITE_AFF_TEXT ) return 0x06;
return 0x07;
}
case TK_CASE: {
int res = 0;
int ii;
ExprList *pList = pExpr->x.pList;
assert( ExprUseXList(pExpr) && pList!=0 );
assert( pList->nExpr > 0);
for(ii=1; ii<pList->nExpr; ii+=2){
res |= sqlite3ExprDataType(pList->a[ii].pExpr);
}
if( pList->nExpr % 2 ){
res |= sqlite3ExprDataType(pList->a[pList->nExpr-1].pExpr);
}
return res;
}
default: {
return 0x01;
}
} /* End of switch(op) */
} /* End of while(pExpr) */
return 0x00;
}
/*
** Set the collating sequence for expression pExpr to be the collating
** sequence named by pToken. Return a pointer to a new Expr node that
** implements the COLLATE operator.
**
** If a memory allocation error occurs, that fact is recorded in pParse->db
** and the pExpr parameter is returned unchanged.
*/
Expr *sqlite3ExprAddCollateToken(
const Parse *pParse, /* Parsing context */
Expr *pExpr, /* Add the "COLLATE" clause to this expression */
const Token *pCollName, /* Name of collating sequence */
int dequote /* True to dequote pCollName */
){
if( pCollName->n>0 ){
Expr *pNew = sqlite3ExprAlloc(pParse->db, TK_COLLATE, pCollName, dequote);
if( pNew ){
pNew->pLeft = pExpr;
pNew->flags |= EP_Collate|EP_Skip;
pExpr = pNew;
}
}
return pExpr;
}
Expr *sqlite3ExprAddCollateString(
const Parse *pParse, /* Parsing context */
Expr *pExpr, /* Add the "COLLATE" clause to this expression */
const char *zC /* The collating sequence name */
){
Token s;
assert( zC!=0 );
sqlite3TokenInit(&s, (char*)zC);
return sqlite3ExprAddCollateToken(pParse, pExpr, &s, 0);
}
/*
** Skip over any TK_COLLATE operators.
*/
Expr *sqlite3ExprSkipCollate(Expr *pExpr){
while( pExpr && ExprHasProperty(pExpr, EP_Skip) ){
assert( pExpr->op==TK_COLLATE );
pExpr = pExpr->pLeft;
}
return pExpr;
}
/*
** Skip over any TK_COLLATE operators and/or any unlikely()
** or likelihood() or likely() functions at the root of an
** expression.
*/
Expr *sqlite3ExprSkipCollateAndLikely(Expr *pExpr){
while( pExpr && ExprHasProperty(pExpr, EP_Skip|EP_Unlikely) ){
if( ExprHasProperty(pExpr, EP_Unlikely) ){
assert( ExprUseXList(pExpr) );
assert( pExpr->x.pList->nExpr>0 );
assert( pExpr->op==TK_FUNCTION );
pExpr = pExpr->x.pList->a[0].pExpr;
}else if( pExpr->op==TK_COLLATE ){
pExpr = pExpr->pLeft;
}else{
break;
}
}
return pExpr;
}
/*
** Return the collation sequence for the expression pExpr. If
** there is no defined collating sequence, return NULL.
**
** See also: sqlite3ExprNNCollSeq()
**
** The sqlite3ExprNNCollSeq() works the same exact that it returns the
** default collation if pExpr has no defined collation.
**
** The collating sequence might be determined by a COLLATE operator
** or by the presence of a column with a defined collating sequence.
** COLLATE operators take first precedence. Left operands take
** precedence over right operands.
*/
CollSeq *sqlite3ExprCollSeq(Parse *pParse, const Expr *pExpr){
sqlite3 *db = pParse->db;
CollSeq *pColl = 0;
const Expr *p = pExpr;
while( p ){
int op = p->op;
if( op==TK_REGISTER ) op = p->op2;
if( (op==TK_AGG_COLUMN && p->y.pTab!=0)
|| op==TK_COLUMN || op==TK_TRIGGER
){
int j;
assert( ExprUseYTab(p) );
assert( p->y.pTab!=0 );
if( (j = p->iColumn)>=0 ){
const char *zColl = sqlite3ColumnColl(&p->y.pTab->aCol[j]);
pColl = sqlite3FindCollSeq(db, ENC(db), zColl, 0);
}
break;
}
if( op==TK_CAST || op==TK_UPLUS ){
p = p->pLeft;
continue;
}
if( op==TK_VECTOR ){
assert( ExprUseXList(p) );
p = p->x.pList->a[0].pExpr;
continue;
}
if( op==TK_COLLATE ){
assert( !ExprHasProperty(p, EP_IntValue) );
pColl = sqlite3GetCollSeq(pParse, ENC(db), 0, p->u.zToken);
break;
}
if( p->flags & EP_Collate ){
if( p->pLeft && (p->pLeft->flags & EP_Collate)!=0 ){
p = p->pLeft;
}else{
Expr *pNext = p->pRight;
/* The Expr.x union is never used at the same time as Expr.pRight */
assert( !ExprUseXList(p) || p->x.pList==0 || p->pRight==0 );
if( ExprUseXList(p) && p->x.pList!=0 && !db->mallocFailed ){
int i;
for(i=0; i<p->x.pList->nExpr; i++){
if( ExprHasProperty(p->x.pList->a[i].pExpr, EP_Collate) ){
pNext = p->x.pList->a[i].pExpr;
break;
}
}
}
p = pNext;
}
}else{
break;
}
}
if( sqlite3CheckCollSeq(pParse, pColl) ){
pColl = 0;
}
return pColl;
}
/*
** Return the collation sequence for the expression pExpr. If
** there is no defined collating sequence, return a pointer to the
** default collation sequence.
**
** See also: sqlite3ExprCollSeq()
**
** The sqlite3ExprCollSeq() routine works the same except that it
** returns NULL if there is no defined collation.
*/
CollSeq *sqlite3ExprNNCollSeq(Parse *pParse, const Expr *pExpr){
CollSeq *p = sqlite3ExprCollSeq(pParse, pExpr);
if( p==0 ) p = pParse->db->pDfltColl;
assert( p!=0 );
return p;
}
/*
** Return TRUE if the two expressions have equivalent collating sequences.
*/
int sqlite3ExprCollSeqMatch(Parse *pParse, const Expr *pE1, const Expr *pE2){
CollSeq *pColl1 = sqlite3ExprNNCollSeq(pParse, pE1);
CollSeq *pColl2 = sqlite3ExprNNCollSeq(pParse, pE2);
return sqlite3StrICmp(pColl1->zName, pColl2->zName)==0;
}
/*
** pExpr is an operand of a comparison operator. aff2 is the
** type affinity of the other operand. This routine returns the
** type affinity that should be used for the comparison operator.
*/
char sqlite3CompareAffinity(const Expr *pExpr, char aff2){
char aff1 = sqlite3ExprAffinity(pExpr);
if( aff1>SQLITE_AFF_NONE && aff2>SQLITE_AFF_NONE ){
/* Both sides of the comparison are columns. If one has numeric
** affinity, use that. Otherwise use no affinity.
*/
if( sqlite3IsNumericAffinity(aff1) || sqlite3IsNumericAffinity(aff2) ){
return SQLITE_AFF_NUMERIC;
}else{
return SQLITE_AFF_BLOB;
}
}else{
/* One side is a column, the other is not. Use the columns affinity. */
assert( aff1<=SQLITE_AFF_NONE || aff2<=SQLITE_AFF_NONE );
return (aff1<=SQLITE_AFF_NONE ? aff2 : aff1) | SQLITE_AFF_NONE;
}
}
/*
** pExpr is a comparison operator. Return the type affinity that should
** be applied to both operands prior to doing the comparison.
*/
static char comparisonAffinity(const Expr *pExpr){
char aff;
assert( pExpr->op==TK_EQ || pExpr->op==TK_IN || pExpr->op==TK_LT ||
pExpr->op==TK_GT || pExpr->op==TK_GE || pExpr->op==TK_LE ||
pExpr->op==TK_NE || pExpr->op==TK_IS || pExpr->op==TK_ISNOT );
assert( pExpr->pLeft );
aff = sqlite3ExprAffinity(pExpr->pLeft);
if( pExpr->pRight ){
aff = sqlite3CompareAffinity(pExpr->pRight, aff);
}else if( ExprUseXSelect(pExpr) ){
aff = sqlite3CompareAffinity(pExpr->x.pSelect->pEList->a[0].pExpr, aff);
}else if( aff==0 ){
aff = SQLITE_AFF_BLOB;
}
return aff;
}
/*
** pExpr is a comparison expression, eg. '=', '<', IN(...) etc.
** idx_affinity is the affinity of an indexed column. Return true
** if the index with affinity idx_affinity may be used to implement
** the comparison in pExpr.
*/
int sqlite3IndexAffinityOk(const Expr *pExpr, char idx_affinity){
char aff = comparisonAffinity(pExpr);
if( aff<SQLITE_AFF_TEXT ){
return 1;
}
if( aff==SQLITE_AFF_TEXT ){
return idx_affinity==SQLITE_AFF_TEXT;
}
return sqlite3IsNumericAffinity(idx_affinity);
}
/*
** Return the P5 value that should be used for a binary comparison
** opcode (OP_Eq, OP_Ge etc.) used to compare pExpr1 and pExpr2.
*/
static u8 binaryCompareP5(
const Expr *pExpr1, /* Left operand */
const Expr *pExpr2, /* Right operand */
int jumpIfNull /* Extra flags added to P5 */
){
u8 aff = (char)sqlite3ExprAffinity(pExpr2);
aff = (u8)sqlite3CompareAffinity(pExpr1, aff) | (u8)jumpIfNull;
return aff;
}
/*
** Return a pointer to the collation sequence that should be used by
** a binary comparison operator comparing pLeft and pRight.
**
** If the left hand expression has a collating sequence type, then it is
** used. Otherwise the collation sequence for the right hand expression
** is used, or the default (BINARY) if neither expression has a collating
** type.
**
** Argument pRight (but not pLeft) may be a null pointer. In this case,
** it is not considered.
*/
CollSeq *sqlite3BinaryCompareCollSeq(
Parse *pParse,
const Expr *pLeft,
const Expr *pRight
){
CollSeq *pColl;
assert( pLeft );
if( pLeft->flags & EP_Collate ){
pColl = sqlite3ExprCollSeq(pParse, pLeft);
}else if( pRight && (pRight->flags & EP_Collate)!=0 ){
pColl = sqlite3ExprCollSeq(pParse, pRight);
}else{
pColl = sqlite3ExprCollSeq(pParse, pLeft);
if( !pColl ){
pColl = sqlite3ExprCollSeq(pParse, pRight);
}
}
return pColl;
}
/* Expression p is a comparison operator. Return a collation sequence
** appropriate for the comparison operator.
**
** This is normally just a wrapper around sqlite3BinaryCompareCollSeq().
** However, if the OP_Commuted flag is set, then the order of the operands
** is reversed in the sqlite3BinaryCompareCollSeq() call so that the
** correct collating sequence is found.
*/
CollSeq *sqlite3ExprCompareCollSeq(Parse *pParse, const Expr *p){
if( ExprHasProperty(p, EP_Commuted) ){
return sqlite3BinaryCompareCollSeq(pParse, p->pRight, p->pLeft);
}else{
return sqlite3BinaryCompareCollSeq(pParse, p->pLeft, p->pRight);
}
}
/*
** Generate code for a comparison operator.
*/
static int codeCompare(
Parse *pParse, /* The parsing (and code generating) context */
Expr *pLeft, /* The left operand */
Expr *pRight, /* The right operand */
int opcode, /* The comparison opcode */
int in1, int in2, /* Register holding operands */
int dest, /* Jump here if true. */
int jumpIfNull, /* If true, jump if either operand is NULL */
int isCommuted /* The comparison has been commuted */
){
int p5;
int addr;
CollSeq *p4;
if( pParse->nErr ) return 0;
if( isCommuted ){
p4 = sqlite3BinaryCompareCollSeq(pParse, pRight, pLeft);
}else{
p4 = sqlite3BinaryCompareCollSeq(pParse, pLeft, pRight);
}
p5 = binaryCompareP5(pLeft, pRight, jumpIfNull);
addr = sqlite3VdbeAddOp4(pParse->pVdbe, opcode, in2, dest, in1,
(void*)p4, P4_COLLSEQ);
sqlite3VdbeChangeP5(pParse->pVdbe, (u8)p5);
return addr;
}
/*
** Return true if expression pExpr is a vector, or false otherwise.
**
** A vector is defined as any expression that results in two or more
** columns of result. Every TK_VECTOR node is an vector because the
** parser will not generate a TK_VECTOR with fewer than two entries.
** But a TK_SELECT might be either a vector or a scalar. It is only
** considered a vector if it has two or more result columns.
*/
int sqlite3ExprIsVector(const Expr *pExpr){
return sqlite3ExprVectorSize(pExpr)>1;
}
/*
** If the expression passed as the only argument is of type TK_VECTOR
** return the number of expressions in the vector. Or, if the expression
** is a sub-select, return the number of columns in the sub-select. For
** any other type of expression, return 1.
*/
int sqlite3ExprVectorSize(const Expr *pExpr){
u8 op = pExpr->op;
if( op==TK_REGISTER ) op = pExpr->op2;
if( op==TK_VECTOR ){
assert( ExprUseXList(pExpr) );
return pExpr->x.pList->nExpr;
}else if( op==TK_SELECT ){
assert( ExprUseXSelect(pExpr) );
return pExpr->x.pSelect->pEList->nExpr;
}else{
return 1;
}
}
/*
** Return a pointer to a subexpression of pVector that is the i-th
** column of the vector (numbered starting with 0). The caller must
** ensure that i is within range.
**
** If pVector is really a scalar (and "scalar" here includes subqueries
** that return a single column!) then return pVector unmodified.
**
** pVector retains ownership of the returned subexpression.
**
** If the vector is a (SELECT ...) then the expression returned is
** just the expression for the i-th term of the result set, and may
** not be ready for evaluation because the table cursor has not yet
** been positioned.
*/
Expr *sqlite3VectorFieldSubexpr(Expr *pVector, int i){
assert( i<sqlite3ExprVectorSize(pVector) || pVector->op==TK_ERROR );
if( sqlite3ExprIsVector(pVector) ){
assert( pVector->op2==0 || pVector->op==TK_REGISTER );
if( pVector->op==TK_SELECT || pVector->op2==TK_SELECT ){
assert( ExprUseXSelect(pVector) );
return pVector->x.pSelect->pEList->a[i].pExpr;
}else{
assert( ExprUseXList(pVector) );
return pVector->x.pList->a[i].pExpr;
}
}
return pVector;
}
/*
** Compute and return a new Expr object which when passed to
** sqlite3ExprCode() will generate all necessary code to compute
** the iField-th column of the vector expression pVector.
**
** It is ok for pVector to be a scalar (as long as iField==0).
** In that case, this routine works like sqlite3ExprDup().
**
** The caller owns the returned Expr object and is responsible for
** ensuring that the
537C
returned value eventually gets freed.
**
** The caller retains ownership of pVector. If pVector is a TK_SELECT,
** then the returned object will reference pVector and so pVector must remain
** valid for the life of the returned object. If pVector is a TK_VECTOR
** or a scalar expression, then it can be deleted as soon as this routine
** returns.
**
** A trick to cause a TK_SELECT pVector to be deleted together with
** the returned Expr object is to attach the pVector to the pRight field
** of the returned TK_SELECT_COLUMN Expr object.
*/
Expr *sqlite3ExprForVectorField(
Parse *pParse, /* Parsing context */
Expr *pVector, /* The vector. List of expressions or a sub-SELECT */
int iField, /* Which column of the vector to return */
int nField /* Total number of columns in the vector */
){
Expr *pRet;
if( pVector->op==TK_SELECT ){
assert( ExprUseXSelect(pVector) );
/* The TK_SELECT_COLUMN Expr node:
**
** pLeft: pVector containing TK_SELECT. Not deleted.
** pRight: not used. But recursively deleted.
** iColumn: Index of a column in pVector
** iTable: 0 or the number of columns on the LHS of an assignment
** pLeft->iTable: First in an array of register holding result, or 0
** if the result is not yet computed.
**
** sqlite3ExprDelete() specifically skips the recursive delete of
** pLeft on TK_SELECT_COLUMN nodes. But pRight is followed, so pVector
** can be attached to pRight to cause this node to take ownership of
** pVector. Typically there will be multiple TK_SELECT_COLUMN nodes
** with the same pLeft pointer to the pVector, but only one of them
** will own the pVector.
*/
pRet = sqlite3PExpr(pParse, TK_SELECT_COLUMN, 0, 0);
if( pRet ){
ExprSetProperty(pRet, EP_FullSize);
pRet->iTable = nField;
pRet->iColumn = iField;
pRet->pLeft = pVector;
}
}else{
if( pVector->op==TK_VECTOR ){
Expr **ppVector;
assert( ExprUseXList(pVector) );
ppVector = &pVector->x.pList->a[iField].pExpr;
pVector = *ppVector;
if( IN_RENAME_OBJECT ){
/* This must be a vector UPDATE inside a trigger */
*ppVector = 0;
return pVector;
}
}
pRet = sqlite3ExprDup(pParse->db, pVector, 0);
}
return pRet;
}
/*
** If expression pExpr is of type TK_SELECT, generate code to evaluate
** it. Return the register in which the result is stored (or, if the
** sub-select returns more than one column, the first in an array
** of registers in which the result is stored).
**
** If pExpr is not a TK_SELECT expression, return 0.
*/
static int exprCodeSubselect(Parse *pParse, Expr *pExpr){
int reg = 0;
#ifndef SQLITE_OMIT_SUBQUERY
if( pExpr->op==TK_SELECT ){
reg = sqlite3CodeSubselect(pParse, pExpr);
}
#endif
return reg;
}
/*
** Argument pVector points to a vector expression - either a TK_VECTOR
** or TK_SELECT that returns more than one column. This function returns
** the register number of a register that contains the value of
** element iField of the vector.
**
** If pVector is a TK_SELECT expression, then code for it must have
** already been generated using the exprCodeSubselect() routine. In this
** case parameter regSelect should be the first in an array of registers
** containing the results of the sub-select.
**
** If pVector is of type TK_VECTOR, then code for the requested field
** is generated. In this case (*pRegFree) may be set to the number of
** a temporary register to be freed by the caller before returning.
**
** Before returning, output parameter (*ppExpr) is set to point to the
** Expr object corresponding to element iElem of the vector.
*/
static int exprVectorRegister(
Parse *pParse, /* Parse context */
Expr *pVector, /* Vector to extract element from */
int iField, /* Field to extract from pVector */
int regSelect, /* First in array of registers */
Expr **ppExpr, /* OUT: Expression element */
int *pRegFree /* OUT: Temp register to free */
){
u8 op = pVector->op;
assert( op==TK_VECTOR || op==TK_REGISTER || op==TK_SELECT || op==TK_ERROR );
if( op==TK_REGISTER ){
*ppExpr = sqlite3VectorFieldSubexpr(pVector, iField);
return pVector->iTable+iField;
}
if( op==TK_SELECT ){
assert( ExprUseXSelect(pVector) );
*ppExpr = pVector->x.pSelect->pEList->a[iField].pExpr;
return regSelect+iField;
}
if( op==TK_VECTOR ){
assert( ExprUseXList(pVector) );
*ppExpr = pVector->x.pList->a[iField].pExpr;
return sqlite3ExprCodeTemp(pParse, *ppExpr, pRegFree);
}
return 0;
}
/*
** Expression pExpr is a comparison between two vector values. Compute
** the result of the comparison (1, 0, or NULL) and write that
** result into register dest.
**
** The caller must satisfy the following preconditions:
**
** if pExpr->op==TK_IS: op==TK_EQ and p5==SQLITE_NULLEQ
** if pExpr->op==TK_ISNOT: op==TK_NE and p5==SQLITE_NULLEQ
** otherwise: op==pExpr->op and p5==0
*/
static void codeVectorCompare(
Parse *pParse, /* Code generator context */
Expr *pExpr, /* The comparison operation */
int dest, /* Write results into this register */
u8 op, /* Comparison operator */
u8 p5 /* SQLITE_NULLEQ or zero */
){
Vdbe *v = pParse->pVdbe;
Expr *pLeft = pExpr->pLeft;
Expr *pRight = pExpr->pRight;
int nLeft = sqlite3ExprVectorSize(pLeft);
int i;
int regLeft = 0;
int regRight = 0;
u8 opx = op;
int addrCmp = 0;
int addrDone = sqlite3VdbeMakeLabel(pParse);
int isCommuted = ExprHasProperty(pExpr,EP_Commuted);
assert( !ExprHasVVAProperty(pExpr,EP_Immutable) );
if( pParse->nErr ) return;
if( nLeft!=sqlite3ExprVectorSize(pRight) ){
sqlite3ErrorMsg(pParse, "row value misused");
return;
}
assert( pExpr->op==TK_EQ || pExpr->op==TK_NE
|| pExpr->op==TK_IS || pExpr->op==TK_ISNOT
|| pExpr->op==TK_LT || pExpr->op==TK_GT
|| pExpr->op==TK_LE || pExpr->op==TK_GE
);
assert( pExpr->op==op || (pExpr->op==TK_IS && op==TK_EQ)
|| (pExpr->op==TK_ISNOT && op==TK_NE) );
assert( p5==0 || pExpr->op!=op );
assert( p5==SQLITE_NULLEQ || pExpr->op==op );
if( op==TK_LE ) opx = TK_LT;
if( op==TK_GE ) opx = TK_GT;
if( op==TK_NE ) opx = TK_EQ;
regLeft = exprCodeSubselect(pParse, pLeft);
regRight = exprCodeSubselect(pParse, pRight);
sqlite3VdbeAddOp2(v, OP_Integer, 1, dest);
for(i=0; 1 /*Loop exits by "break"*/; i++){
int regFree1 = 0, regFree2 = 0;
Expr *pL = 0, *pR = 0;
int r1, r2;
assert( i>=0 && i<nLeft );
if( addrCmp ) sqlite3VdbeJumpHere(v, addrCmp);
r1 = exprVectorRegister(pParse, pLeft, i, regLeft, &pL, ®Free1);
r2 = exprVectorRegister(pParse, pRight, i, regRight, &pR, ®Free2);
addrCmp = sqlite3VdbeCurrentAddr(v);
codeCompare(pParse, pL, pR, opx, r1, r2, addrDone, p5, isCommuted);
testcase(op==OP_Lt); VdbeCoverageIf(v,op==OP_Lt);
testcase(op==OP_Le); VdbeCoverageIf(v,op==OP_Le);
testcase(op==OP_Gt); VdbeCoverageIf(v,op==OP_Gt);
testcase(op==OP_Ge); VdbeCoverageIf(v,op==OP_Ge);
testcase(op==OP_Eq); VdbeCoverageIf(v,op==OP_Eq);
testcase(op==OP_Ne); VdbeCoverageIf(v,op==OP_Ne);
sqlite3ReleaseTempReg(pParse, regFree1);
sqlite3ReleaseTempReg(pParse, regFree2);
if( (opx==TK_LT || opx==TK_GT) && i<nLeft-1 ){
addrCmp = sqlite3VdbeAddOp0(v, OP_ElseEq);
testcase(opx==TK_LT); VdbeCoverageIf(v,opx==TK_LT);
testcase(opx==TK_GT); VdbeCoverageIf(v,opx==TK_GT);
}
if( p5==SQLITE_NULLEQ ){
sqlite3VdbeAddOp2(v, OP_Integer, 0, dest);
}else{
sqlite3VdbeAddOp3(v, OP_ZeroOrNull, r1, dest, r2);
}
if( i==nLeft-1 ){
break;
}
if( opx==TK_EQ ){
sqlite3VdbeAddOp2(v, OP_NotNull, dest, addrDone); VdbeCoverage(v);
}else{
assert( op==TK_LT || op==TK_GT || op==TK_LE || op==TK_GE );
sqlite3VdbeAddOp2(v, OP_Goto, 0, addrDone);
if( i==nLeft-2 ) opx = op;
}
}
sqlite3VdbeJumpHere(v, addrCmp);
sqlite3VdbeResolveLabel(v, addrDone);
if( op==TK_NE ){
sqlite3VdbeAddOp2(v, OP_Not, dest, dest);
}
}
#if SQLITE_MAX_EXPR_DEPTH>0
/*
** Check that argument nHeight is less than or equal to the maximum
** expression depth allowed. If it is not, leave an error message in
** pParse.
*/
int sqlite3ExprCheckHeight(Parse *pParse, int nHeight){
int rc = SQLITE_OK;
int mxHeight = pParse->db->aLimit[SQLITE_LIMIT_EXPR_DEPTH];
if( nHeight>mxHeight ){
sqlite3ErrorMsg(pParse,
"Expression tree is too large (maximum depth %d)", mxHeight
);
rc = SQLITE_ERROR;
}
return rc;
}
/* The following three functions, heightOfExpr(), heightOfExprList()
** and heightOfSelect(), are used to determine the maximum height
** of any expression tree referenced by the structure passed as the
** first argument.
**
** If this maximum height is greater than the current value pointed
** to by pnHeight, the second parameter, then set *pnHeight to that
** value.
*/
static void heightOfExpr(const Expr *p, int *pnHeight){
if( p ){
if( p->nHeight>*pnHeight ){
*pnHeight = p->nHeight;
}
}
}
static void heightOfExprList(const ExprList *p, int *pnHeight){
if( p ){
int i;
for(i=0; i<p->nExpr; i++){
heightOfExpr(p->a[i].pExpr, pnHeight);
}
}
}
static void heightOfSelect(const Select *pSelect, int *pnHeight){
const Select *p;
for(p=pSelect; p; p=p->pPrior){
heightOfExpr(p->pWhere, pnHeight);
heightOfExpr(p->pHaving, pnHeight);
heightOfExpr(p->pLimit, pnHeight);
heightOfExprList(p->pEList, pnHeight);
heightOfExprList(p->pGroupBy, pnHeight);
heightOfExprList(p->pOrderBy, pnHeight);
}
}
/*
** Set the Expr.nHeight variable in the structure passed as an
** argument. An expression with no children, Expr.pList or
** Expr.pSelect member has a height of 1. Any other expression
** has a height equal to the maximum height of any other
** referenced Expr plus one.
**
** Also propagate EP_Propagate flags up from Expr.x.pList to Expr.flags,
** if appropriate.
*/
static void exprSetHeight(Expr *p){
int nHeight = p->pLeft ? p->pLeft->nHeight : 0;
if( NEVER(p->pRight) && p->pRight->nHeight>nHeight ){
nHeight = p->pRight->nHeight;
}
if( ExprUseXSelect(p) ){
heightOfSelect(p->x.pSelect, &nHeight);
}else if( p->x.pList ){
heightOfExprList(p->x.pList, &nHeight);
p->flags |= EP_Propagate & sqlite3ExprListFlags(p->x.pList);
}
p->nHeight = nHeight + 1;
}
/*
** Set the Expr.nHeight variable using the exprSetHeight() function. If
** the height is greater than the maximum allowed expression depth,
** leave an error in pParse.
**
** Also propagate all EP_Propagate flags from the Expr.x.pList into
** Expr.flags.
*/
void sqlite3ExprSetHeightAndFlags(Parse *pParse, Expr *p){
if( pParse->nErr ) return;
exprSetHeight(p);
sqlite3ExprCheckHeight(pParse, p->nHeight);
}
/*
** Return the maximum height of any expression tree referenced
** by the select statement passed as an argument.
*/
int sqlite3SelectExprHeight(const Select *p){
int nHeight = 0;
heightOfSelect(p, &nHeight);
return nHeight;
}
#else /* ABOVE: Height enforcement enabled. BELOW: Height enforcement off */
/*
** Propagate all EP_Propagate flags from the Expr.x.pList into
** Expr.flags.
*/
void sqlite3ExprSetHeightAndFlags(Parse *pParse, Expr *p){
if( pParse->nErr ) return;
if( p && ExprUseXList(p) && p->x.pList ){
p->flags |= EP_Propagate & sqlite3ExprListFlags(p->x.pList);
}
}
#define exprSetHeight(y)
#endif /* SQLITE_MAX_EXPR_DEPTH>0 */
/*
** Set the error offset for an Expr node, if possible.
*/
void sqlite3ExprSetErrorOffset(Expr *pExpr, int iOfst){
if( pExpr==0 ) return;
if( NEVER(ExprUseWJoin(pExpr)) ) return;
pExpr->w.iOfst = iOfst;
}
/*
** This routine is the core allocator for Expr nodes.
**
** Construct a new expression node and return a pointer to it. Memory
** for this node and for the pToken argument is a single allocation
** obtained from sqlite3DbMalloc(). The calling function
** is responsible for making sure the node eventually gets freed.
**
** If dequote is true, then the token (if it exists) is dequoted.
** If dequote is false, no dequoting is performed. The deQuote
** parameter is ignored if pToken is NULL or if the token does not
** appear to be quoted. If the quotes were of the form "..." (double-quotes)
** then the EP_DblQuoted flag is set on the expression node.
**
** Special case (tag-20240227-a): If op==TK_INTEGER and pToken points to
** a string that can be translated into a 32-bit integer, then the token is
** not stored in u.zToken. Instead, the integer values is written
** into u.iValue and the EP_IntValue flag is set. No extra storage
** is allocated to hold the integer text and the dequote flag is ignored.
** See also tag-20240227-b.
*/
Expr *sqlite3ExprAlloc(
sqlite3 *db, /* Handle for sqlite3DbMallocRawNN() */
int op, /* Expression opcode */
const Token *pToken, /* Token argument. Might be NULL */
int dequote /* True to dequote */
){
Expr *pNew;
int nExtra = 0;
int iValue = 0;
assert( db!=0 );
if( pToken ){
if( op!=TK_INTEGER || pToken->z==0
|| sqlite3GetInt32(pToken->z, &iValue)==0 ){
nExtra = pToken->n+1; /* tag-20240227-a */
assert( iValue>=0 );
}
}
pNew = sqlite3DbMallocRawNN(db, sizeof(Expr)+nExtra);
if( pNew ){
memset(pNew, 0, sizeof(Expr));
pNew->op = (u8)op;
pNew->iAgg = -1;
if( pToken ){
if( nExtra==0 ){
pNew->flags |= EP_IntValue|EP_Leaf|(iValue?EP_IsTrue:EP_IsFalse);
pNew->u.iValue = iValue;
}else{
pNew->u.zToken = (char*)&pNew[1];
assert( pToken->z!=0 || pToken->n==0 );
if( pToken->n ) memcpy(pNew->u.zToken, pToken->z, pToken->n);
pNew->u.zToken[pToken->n] = 0;
if( dequote && sqlite3Isquote(pNew->u.zToken[0]) ){
sqlite3DequoteExpr(pNew);
}
}
}
#if SQLITE_MAX_EXPR_DEPTH>0
pNew->nHeight = 1;
#endif
}
return pNew;
}
/*
** Allocate a new expression node from a zero-terminated token that has
** already been dequoted.
*/
Expr *sqlite3Expr(
sqlite3 *db, /* Handle for sqlite3DbMallocZero() (may be null) */
int op, /* Expression opcode */
const char *zToken /* Token argument. Might be NULL */
){
Token x;
x.z = zToken;
x.n = sqlite3Strlen30(zToken);
return sqlite3ExprAlloc(db, op, &x, 0);
}
/*
** Attach subtrees pLeft and pRight to the Expr node pRoot.
**
** If pRoot==NULL that means that a memory allocation error has occurred.
** In that case, delete the subtrees pLeft and pRight.
*/
void sqlite3ExprAttachSubtrees(
sqlite3 *db,
Expr *pRoot,
Expr *pLeft,
Expr *pRight
){
if( pRoot==0 ){
assert( db->mallocFailed );
sqlite3ExprDelete(db, pLeft);