1/*
2** 2001 September 15
3**
4** The author disclaims copyright to this source code. In place of
5** a legal notice, here is a blessing:
6**
7** May you do good and not evil.
8** May you find forgiveness for yourself and forgive others.
9** May you share freely, never taking more than you give.
10**
11*************************************************************************
12** This file contains routines used for analyzing expressions and
13** for generating VDBE code that evaluates expressions in SQLite.
14*/
15#include "sqliteInt.h"
16
17/* Forward declarations */
18static void exprCodeBetween(Parse*,Expr*,int,void(*)(Parse*,Expr*,int,int),int);
19static int exprCodeVector(Parse *pParse, Expr *p, int *piToFree);
20
21/*
22** Return the affinity character for a single column of a table.
23*/
24char sqlite3TableColumnAffinity(const Table *pTab, int iCol){
25 if( iCol<0 || NEVER(iCol>=pTab->nCol) ) return SQLITE_AFF_INTEGER;
26 return pTab->aCol[iCol].affinity;
27}
28
29/*
30** Return the 'affinity' of the expression pExpr if any.
31**
32** If pExpr is a column, a reference to a column via an 'AS' alias,
33** or a sub-select with a column as the return value, then the
34** affinity of that column is returned. Otherwise, 0x00 is returned,
35** indicating no affinity for the expression.
36**
37** i.e. the WHERE clause expressions in the following statements all
38** have an affinity:
39**
40** CREATE TABLE t1(a);
41** SELECT * FROM t1 WHERE a;
42** SELECT a AS b FROM t1 WHERE b;
43** SELECT * FROM t1 WHERE (select a from t1);
44*/
45char sqlite3ExprAffinity(const Expr *pExpr){
46 int op;
47 while( ExprHasProperty(pExpr, EP_Skip|EP_IfNullRow) ){
48 assert( pExpr->op==TK_COLLATE
49 || pExpr->op==TK_IF_NULL_ROW
50 || (pExpr->op==TK_REGISTER && pExpr->op2==TK_IF_NULL_ROW) );
51 pExpr = pExpr->pLeft;
52 assert( pExpr!=0 );
53 }
54 op = pExpr->op;
55 if( op==TK_REGISTER ) op = pExpr->op2;
56 if( op==TK_COLUMN || op==TK_AGG_COLUMN ){
57 assert( ExprUseYTab(pExpr) );
58 assert( pExpr->y.pTab!=0 );
59 return sqlite3TableColumnAffinity(pExpr->y.pTab, pExpr->iColumn);
60 }
61 if( op==TK_SELECT ){
62 assert( ExprUseXSelect(pExpr) );
63 assert( pExpr->x.pSelect!=0 );
64 assert( pExpr->x.pSelect->pEList!=0 );
65 assert( pExpr->x.pSelect->pEList->a[0].pExpr!=0 );
66 return sqlite3ExprAffinity(pExpr->x.pSelect->pEList->a[0].pExpr);
67 }
68#ifndef SQLITE_OMIT_CAST
69 if( op==TK_CAST ){
70 assert( !ExprHasProperty(pExpr, EP_IntValue) );
71 return sqlite3AffinityType(pExpr->u.zToken, 0);
72 }
73#endif
74 if( op==TK_SELECT_COLUMN ){
75 assert( pExpr->pLeft!=0 && ExprUseXSelect(pExpr->pLeft) );
76 assert( pExpr->iColumn < pExpr->iTable );
77 assert( pExpr->iTable==pExpr->pLeft->x.pSelect->pEList->nExpr );
78 return sqlite3ExprAffinity(
79 pExpr->pLeft->x.pSelect->pEList->a[pExpr->iColumn].pExpr
80 );
81 }
82 if( op==TK_VECTOR ){
83 assert( ExprUseXList(pExpr) );
84 return sqlite3ExprAffinity(pExpr->x.pList->a[0].pExpr);
85 }
86 return pExpr->affExpr;
87}
88
89/*
90** Set the collating sequence for expression pExpr to be the collating
91** sequence named by pToken. Return a pointer to a new Expr node that
92** implements the COLLATE operator.
93**
94** If a memory allocation error occurs, that fact is recorded in pParse->db
95** and the pExpr parameter is returned unchanged.
96*/
97Expr *sqlite3ExprAddCollateToken(
98 const Parse *pParse, /* Parsing context */
99 Expr *pExpr, /* Add the "COLLATE" clause to this expression */
100 const Token *pCollName, /* Name of collating sequence */
101 int dequote /* True to dequote pCollName */
102){
103 if( pCollName->n>0 ){
104 Expr *pNew = sqlite3ExprAlloc(pParse->db, TK_COLLATE, pCollName, dequote);
105 if( pNew ){
106 pNew->pLeft = pExpr;
107 pNew->flags |= EP_Collate|EP_Skip;
108 pExpr = pNew;
109 }
110 }
111 return pExpr;
112}
113Expr *sqlite3ExprAddCollateString(
114 const Parse *pParse, /* Parsing context */
115 Expr *pExpr, /* Add the "COLLATE" clause to this expression */
116 const char *zC /* The collating sequence name */
117){
118 Token s;
119 assert( zC!=0 );
120 sqlite3TokenInit(&s, (char*)zC);
121 return sqlite3ExprAddCollateToken(pParse, pExpr, &s, 0);
122}
123
124/*
125** Skip over any TK_COLLATE operators.
126*/
127Expr *sqlite3ExprSkipCollate(Expr *pExpr){
128 while( pExpr && ExprHasProperty(pExpr, EP_Skip) ){
129 assert( pExpr->op==TK_COLLATE );
130 pExpr = pExpr->pLeft;
131 }
132 return pExpr;
133}
134
135/*
136** Skip over any TK_COLLATE operators and/or any unlikely()
137** or likelihood() or likely() functions at the root of an
138** expression.
139*/
140Expr *sqlite3ExprSkipCollateAndLikely(Expr *pExpr){
141 while( pExpr && ExprHasProperty(pExpr, EP_Skip|EP_Unlikely) ){
142 if( ExprHasProperty(pExpr, EP_Unlikely) ){
143 assert( ExprUseXList(pExpr) );
144 assert( pExpr->x.pList->nExpr>0 );
145 assert( pExpr->op==TK_FUNCTION );
146 pExpr = pExpr->x.pList->a[0].pExpr;
147 }else{
148 assert( pExpr->op==TK_COLLATE );
149 pExpr = pExpr->pLeft;
150 }
151 }
152 return pExpr;
153}
154
155/*
156** Return the collation sequence for the expression pExpr. If
157** there is no defined collating sequence, return NULL.
158**
159** See also: sqlite3ExprNNCollSeq()
160**
161** The sqlite3ExprNNCollSeq() works the same exact that it returns the
162** default collation if pExpr has no defined collation.
163**
164** The collating sequence might be determined by a COLLATE operator
165** or by the presence of a column with a defined collating sequence.
166** COLLATE operators take first precedence. Left operands take
167** precedence over right operands.
168*/
169CollSeq *sqlite3ExprCollSeq(Parse *pParse, const Expr *pExpr){
170 sqlite3 *db = pParse->db;
171 CollSeq *pColl = 0;
172 const Expr *p = pExpr;
173 while( p ){
174 int op = p->op;
175 if( op==TK_REGISTER ) op = p->op2;
176 if( op==TK_AGG_COLUMN || op==TK_COLUMN || op==TK_TRIGGER ){
177 int j;
178 assert( ExprUseYTab(p) );
179 assert( p->y.pTab!=0 );
180 if( (j = p->iColumn)>=0 ){
181 const char *zColl = sqlite3ColumnColl(&p->y.pTab->aCol[j]);
182 pColl = sqlite3FindCollSeq(db, ENC(db), zColl, 0);
183 }
184 break;
185 }
186 if( op==TK_CAST || op==TK_UPLUS ){
187 p = p->pLeft;
188 continue;
189 }
190 if( op==TK_VECTOR ){
191 assert( ExprUseXList(p) );
192 p = p->x.pList->a[0].pExpr;
193 continue;
194 }
195 if( op==TK_COLLATE ){
196 assert( !ExprHasProperty(p, EP_IntValue) );
197 pColl = sqlite3GetCollSeq(pParse, ENC(db), 0, p->u.zToken);
198 break;
199 }
200 if( p->flags & EP_Collate ){
201 if( p->pLeft && (p->pLeft->flags & EP_Collate)!=0 ){
202 p = p->pLeft;
203 }else{
204 Expr *pNext = p->pRight;
205 /* The Expr.x union is never used at the same time as Expr.pRight */
206 assert( ExprUseXList(p) );
207 assert( p->x.pList==0 || p->pRight==0 );
208 if( p->x.pList!=0 && !db->mallocFailed ){
209 int i;
210 for(i=0; ALWAYS(i<p->x.pList->nExpr); i++){
211 if( ExprHasProperty(p->x.pList->a[i].pExpr, EP_Collate) ){
212 pNext = p->x.pList->a[i].pExpr;
213 break;
214 }
215 }
216 }
217 p = pNext;
218 }
219 }else{
220 break;
221 }
222 }
223 if( sqlite3CheckCollSeq(pParse, pColl) ){
224 pColl = 0;
225 }
226 return pColl;
227}
228
229/*
230** Return the collation sequence for the expression pExpr. If
231** there is no defined collating sequence, return a pointer to the
232** defautl collation sequence.
233**
234** See also: sqlite3ExprCollSeq()
235**
236** The sqlite3ExprCollSeq() routine works the same except that it
237** returns NULL if there is no defined collation.
238*/
239CollSeq *sqlite3ExprNNCollSeq(Parse *pParse, const Expr *pExpr){
240 CollSeq *p = sqlite3ExprCollSeq(pParse, pExpr);
241 if( p==0 ) p = pParse->db->pDfltColl;
242 assert( p!=0 );
243 return p;
244}
245
246/*
247** Return TRUE if the two expressions have equivalent collating sequences.
248*/
249int sqlite3ExprCollSeqMatch(Parse *pParse, const Expr *pE1, const Expr *pE2){
250 CollSeq *pColl1 = sqlite3ExprNNCollSeq(pParse, pE1);
251 CollSeq *pColl2 = sqlite3ExprNNCollSeq(pParse, pE2);
252 return sqlite3StrICmp(pColl1->zName, pColl2->zName)==0;
253}
254
255/*
256** pExpr is an operand of a comparison operator. aff2 is the
257** type affinity of the other operand. This routine returns the
258** type affinity that should be used for the comparison operator.
259*/
260char sqlite3CompareAffinity(const Expr *pExpr, char aff2){
261 char aff1 = sqlite3ExprAffinity(pExpr);
262 if( aff1>SQLITE_AFF_NONE && aff2>SQLITE_AFF_NONE ){
263 /* Both sides of the comparison are columns. If one has numeric
264 ** affinity, use that. Otherwise use no affinity.
265 */
266 if( sqlite3IsNumericAffinity(aff1) || sqlite3IsNumericAffinity(aff2) ){
267 return SQLITE_AFF_NUMERIC;
268 }else{
269 return SQLITE_AFF_BLOB;
270 }
271 }else{
272 /* One side is a column, the other is not. Use the columns affinity. */
273 assert( aff1<=SQLITE_AFF_NONE || aff2<=SQLITE_AFF_NONE );
274 return (aff1<=SQLITE_AFF_NONE ? aff2 : aff1) | SQLITE_AFF_NONE;
275 }
276}
277
278/*
279** pExpr is a comparison operator. Return the type affinity that should
280** be applied to both operands prior to doing the comparison.
281*/
282static char comparisonAffinity(const Expr *pExpr){
283 char aff;
284 assert( pExpr->op==TK_EQ || pExpr->op==TK_IN || pExpr->op==TK_LT ||
285 pExpr->op==TK_GT || pExpr->op==TK_GE || pExpr->op==TK_LE ||
286 pExpr->op==TK_NE || pExpr->op==TK_IS || pExpr->op==TK_ISNOT );
287 assert( pExpr->pLeft );
288 aff = sqlite3ExprAffinity(pExpr->pLeft);
289 if( pExpr->pRight ){
290 aff = sqlite3CompareAffinity(pExpr->pRight, aff);
291 }else if( ExprUseXSelect(pExpr) ){
292 aff = sqlite3CompareAffinity(pExpr->x.pSelect->pEList->a[0].pExpr, aff);
293 }else if( aff==0 ){
294 aff = SQLITE_AFF_BLOB;
295 }
296 return aff;
297}
298
299/*
300** pExpr is a comparison expression, eg. '=', '<', IN(...) etc.
301** idx_affinity is the affinity of an indexed column. Return true
302** if the index with affinity idx_affinity may be used to implement
303** the comparison in pExpr.
304*/
305int sqlite3IndexAffinityOk(const Expr *pExpr, char idx_affinity){
306 char aff = comparisonAffinity(pExpr);
307 if( aff<SQLITE_AFF_TEXT ){
308 return 1;
309 }
310 if( aff==SQLITE_AFF_TEXT ){
311 return idx_affinity==SQLITE_AFF_TEXT;
312 }
313 return sqlite3IsNumericAffinity(idx_affinity);
314}
315
316/*
317** Return the P5 value that should be used for a binary comparison
318** opcode (OP_Eq, OP_Ge etc.) used to compare pExpr1 and pExpr2.
319*/
320static u8 binaryCompareP5(
321 const Expr *pExpr1, /* Left operand */
322 const Expr *pExpr2, /* Right operand */
323 int jumpIfNull /* Extra flags added to P5 */
324){
325 u8 aff = (char)sqlite3ExprAffinity(pExpr2);
326 aff = (u8)sqlite3CompareAffinity(pExpr1, aff) | (u8)jumpIfNull;
327 return aff;
328}
329
330/*
331** Return a pointer to the collation sequence that should be used by
332** a binary comparison operator comparing pLeft and pRight.
333**
334** If the left hand expression has a collating sequence type, then it is
335** used. Otherwise the collation sequence for the right hand expression
336** is used, or the default (BINARY) if neither expression has a collating
337** type.
338**
339** Argument pRight (but not pLeft) may be a null pointer. In this case,
340** it is not considered.
341*/
342CollSeq *sqlite3BinaryCompareCollSeq(
343 Parse *pParse,
344 const Expr *pLeft,
345 const Expr *pRight
346){
347 CollSeq *pColl;
348 assert( pLeft );
349 if( pLeft->flags & EP_Collate ){
350 pColl = sqlite3ExprCollSeq(pParse, pLeft);
351 }else if( pRight && (pRight->flags & EP_Collate)!=0 ){
352 pColl = sqlite3ExprCollSeq(pParse, pRight);
353 }else{
354 pColl = sqlite3ExprCollSeq(pParse, pLeft);
355 if( !pColl ){
356 pColl = sqlite3ExprCollSeq(pParse, pRight);
357 }
358 }
359 return pColl;
360}
361
362/* Expresssion p is a comparison operator. Return a collation sequence
363** appropriate for the comparison operator.
364**
365** This is normally just a wrapper around sqlite3BinaryCompareCollSeq().
366** However, if the OP_Commuted flag is set, then the order of the operands
367** is reversed in the sqlite3BinaryCompareCollSeq() call so that the
368** correct collating sequence is found.
369*/
370CollSeq *sqlite3ExprCompareCollSeq(Parse *pParse, const Expr *p){
371 if( ExprHasProperty(p, EP_Commuted) ){
372 return sqlite3BinaryCompareCollSeq(pParse, p->pRight, p->pLeft);
373 }else{
374 return sqlite3BinaryCompareCollSeq(pParse, p->pLeft, p->pRight);
375 }
376}
377
378/*
379** Generate code for a comparison operator.
380*/
381static int codeCompare(
382 Parse *pParse, /* The parsing (and code generating) context */
383 Expr *pLeft, /* The left operand */
384 Expr *pRight, /* The right operand */
385 int opcode, /* The comparison opcode */
386 int in1, int in2, /* Register holding operands */
387 int dest, /* Jump here if true. */
388 int jumpIfNull, /* If true, jump if either operand is NULL */
389 int isCommuted /* The comparison has been commuted */
390){
391 int p5;
392 int addr;
393 CollSeq *p4;
394
395 if( pParse->nErr ) return 0;
396 if( isCommuted ){
397 p4 = sqlite3BinaryCompareCollSeq(pParse, pRight, pLeft);
398 }else{
399 p4 = sqlite3BinaryCompareCollSeq(pParse, pLeft, pRight);
400 }
401 p5 = binaryCompareP5(pLeft, pRight, jumpIfNull);
402 addr = sqlite3VdbeAddOp4(pParse->pVdbe, opcode, in2, dest, in1,
403 (void*)p4, P4_COLLSEQ);
404 sqlite3VdbeChangeP5(pParse->pVdbe, (u8)p5);
405 return addr;
406}
407
408/*
409** Return true if expression pExpr is a vector, or false otherwise.
410**
411** A vector is defined as any expression that results in two or more
412** columns of result. Every TK_VECTOR node is an vector because the
413** parser will not generate a TK_VECTOR with fewer than two entries.
414** But a TK_SELECT might be either a vector or a scalar. It is only
415** considered a vector if it has two or more result columns.
416*/
417int sqlite3ExprIsVector(const Expr *pExpr){
418 return sqlite3ExprVectorSize(pExpr)>1;
419}
420
421/*
422** If the expression passed as the only argument is of type TK_VECTOR
423** return the number of expressions in the vector. Or, if the expression
424** is a sub-select, return the number of columns in the sub-select. For
425** any other type of expression, return 1.
426*/
427int sqlite3ExprVectorSize(const Expr *pExpr){
428 u8 op = pExpr->op;
429 if( op==TK_REGISTER ) op = pExpr->op2;
430 if( op==TK_VECTOR ){
431 assert( ExprUseXList(pExpr) );
432 return pExpr->x.pList->nExpr;
433 }else if( op==TK_SELECT ){
434 assert( ExprUseXSelect(pExpr) );
435 return pExpr->x.pSelect->pEList->nExpr;
436 }else{
437 return 1;
438 }
439}
440
441/*
442** Return a pointer to a subexpression of pVector that is the i-th
443** column of the vector (numbered starting with 0). The caller must
444** ensure that i is within range.
445**
446** If pVector is really a scalar (and "scalar" here includes subqueries
447** that return a single column!) then return pVector unmodified.
448**
449** pVector retains ownership of the returned subexpression.
450**
451** If the vector is a (SELECT ...) then the expression returned is
452** just the expression for the i-th term of the result set, and may
453** not be ready for evaluation because the table cursor has not yet
454** been positioned.
455*/
456Expr *sqlite3VectorFieldSubexpr(Expr *pVector, int i){
457 assert( i<sqlite3ExprVectorSize(pVector) || pVector->op==TK_ERROR );
458 if( sqlite3ExprIsVector(pVector) ){
459 assert( pVector->op2==0 || pVector->op==TK_REGISTER );
460 if( pVector->op==TK_SELECT || pVector->op2==TK_SELECT ){
461 assert( ExprUseXSelect(pVector) );
462 return pVector->x.pSelect->pEList->a[i].pExpr;
463 }else{
464 assert( ExprUseXList(pVector) );
465 return pVector->x.pList->a[i].pExpr;
466 }
467 }
468 return pVector;
469}
470
471/*
472** Compute and return a new Expr object which when passed to
473** sqlite3ExprCode() will generate all necessary code to compute
474** the iField-th column of the vector expression pVector.
475**
476** It is ok for pVector to be a scalar (as long as iField==0).
477** In that case, this routine works like sqlite3ExprDup().
478**
479** The caller owns the returned Expr object and is responsible for
480** ensuring that the returned value eventually gets freed.
481**
482** The caller retains ownership of pVector. If pVector is a TK_SELECT,
483** then the returned object will reference pVector and so pVector must remain
484** valid for the life of the returned object. If pVector is a TK_VECTOR
485** or a scalar expression, then it can be deleted as soon as this routine
486** returns.
487**
488** A trick to cause a TK_SELECT pVector to be deleted together with
489** the returned Expr object is to attach the pVector to the pRight field
490** of the returned TK_SELECT_COLUMN Expr object.
491*/
492Expr *sqlite3ExprForVectorField(
493 Parse *pParse, /* Parsing context */
494 Expr *pVector, /* The vector. List of expressions or a sub-SELECT */
495 int iField, /* Which column of the vector to return */
496 int nField /* Total number of columns in the vector */
497){
498 Expr *pRet;
499 if( pVector->op==TK_SELECT ){
500 assert( ExprUseXSelect(pVector) );
501 /* The TK_SELECT_COLUMN Expr node:
502 **
503 ** pLeft: pVector containing TK_SELECT. Not deleted.
504 ** pRight: not used. But recursively deleted.
505 ** iColumn: Index of a column in pVector
506 ** iTable: 0 or the number of columns on the LHS of an assignment
507 ** pLeft->iTable: First in an array of register holding result, or 0
508 ** if the result is not yet computed.
509 **
510 ** sqlite3ExprDelete() specifically skips the recursive delete of
511 ** pLeft on TK_SELECT_COLUMN nodes. But pRight is followed, so pVector
512 ** can be attached to pRight to cause this node to take ownership of
513 ** pVector. Typically there will be multiple TK_SELECT_COLUMN nodes
514 ** with the same pLeft pointer to the pVector, but only one of them
515 ** will own the pVector.
516 */
517 pRet = sqlite3PExpr(pParse, TK_SELECT_COLUMN, 0, 0);
518 if( pRet ){
519 pRet->iTable = nField;
520 pRet->iColumn = iField;
521 pRet->pLeft = pVector;
522 }
523 }else{
524 if( pVector->op==TK_VECTOR ){
525 Expr **ppVector;
526 assert( ExprUseXList(pVector) );
527 ppVector = &pVector->x.pList->a[iField].pExpr;
528 pVector = *ppVector;
529 if( IN_RENAME_OBJECT ){
530 /* This must be a vector UPDATE inside a trigger */
531 *ppVector = 0;
532 return pVector;
533 }
534 }
535 pRet = sqlite3ExprDup(pParse->db, pVector, 0);
536 }
537 return pRet;
538}
539
540/*
541** If expression pExpr is of type TK_SELECT, generate code to evaluate
542** it. Return the register in which the result is stored (or, if the
543** sub-select returns more than one column, the first in an array
544** of registers in which the result is stored).
545**
546** If pExpr is not a TK_SELECT expression, return 0.
547*/
548static int exprCodeSubselect(Parse *pParse, Expr *pExpr){
549 int reg = 0;
550#ifndef SQLITE_OMIT_SUBQUERY
551 if( pExpr->op==TK_SELECT ){
552 reg = sqlite3CodeSubselect(pParse, pExpr);
553 }
554#endif
555 return reg;
556}
557
558/*
559** Argument pVector points to a vector expression - either a TK_VECTOR
560** or TK_SELECT that returns more than one column. This function returns
561** the register number of a register that contains the value of
562** element iField of the vector.
563**
564** If pVector is a TK_SELECT expression, then code for it must have
565** already been generated using the exprCodeSubselect() routine. In this
566** case parameter regSelect should be the first in an array of registers
567** containing the results of the sub-select.
568**
569** If pVector is of type TK_VECTOR, then code for the requested field
570** is generated. In this case (*pRegFree) may be set to the number of
571** a temporary register to be freed by the caller before returning.
572**
573** Before returning, output parameter (*ppExpr) is set to point to the
574** Expr object corresponding to element iElem of the vector.
575*/
576static int exprVectorRegister(
577 Parse *pParse, /* Parse context */
578 Expr *pVector, /* Vector to extract element from */
579 int iField, /* Field to extract from pVector */
580 int regSelect, /* First in array of registers */
581 Expr **ppExpr, /* OUT: Expression element */
582 int *pRegFree /* OUT: Temp register to free */
583){
584 u8 op = pVector->op;
585 assert( op==TK_VECTOR || op==TK_REGISTER || op==TK_SELECT || op==TK_ERROR );
586 if( op==TK_REGISTER ){
587 *ppExpr = sqlite3VectorFieldSubexpr(pVector, iField);
588 return pVector->iTable+iField;
589 }
590 if( op==TK_SELECT ){
591 assert( ExprUseXSelect(pVector) );
592 *ppExpr = pVector->x.pSelect->pEList->a[iField].pExpr;
593 return regSelect+iField;
594 }
595 if( op==TK_VECTOR ){
596 assert( ExprUseXList(pVector) );
597 *ppExpr = pVector->x.pList->a[iField].pExpr;
598 return sqlite3ExprCodeTemp(pParse, *ppExpr, pRegFree);
599 }
600 return 0;
601}
602
603/*
604** Expression pExpr is a comparison between two vector values. Compute
605** the result of the comparison (1, 0, or NULL) and write that
606** result into register dest.
607**
608** The caller must satisfy the following preconditions:
609**
610** if pExpr->op==TK_IS: op==TK_EQ and p5==SQLITE_NULLEQ
611** if pExpr->op==TK_ISNOT: op==TK_NE and p5==SQLITE_NULLEQ
612** otherwise: op==pExpr->op and p5==0
613*/
614static void codeVectorCompare(
615 Parse *pParse, /* Code generator context */
616 Expr *pExpr, /* The comparison operation */
617 int dest, /* Write results into this register */
618 u8 op, /* Comparison operator */
619 u8 p5 /* SQLITE_NULLEQ or zero */
620){
621 Vdbe *v = pParse->pVdbe;
622 Expr *pLeft = pExpr->pLeft;
623 Expr *pRight = pExpr->pRight;
624 int nLeft = sqlite3ExprVectorSize(pLeft);
625 int i;
626 int regLeft = 0;
627 int regRight = 0;
628 u8 opx = op;
629 int addrCmp = 0;
630 int addrDone = sqlite3VdbeMakeLabel(pParse);
631 int isCommuted = ExprHasProperty(pExpr,EP_Commuted);
632
633 assert( !ExprHasVVAProperty(pExpr,EP_Immutable) );
634 if( pParse->nErr ) return;
635 if( nLeft!=sqlite3ExprVectorSize(pRight) ){
636 sqlite3ErrorMsg(pParse, "row value misused");
637 return;
638 }
639 assert( pExpr->op==TK_EQ || pExpr->op==TK_NE
640 || pExpr->op==TK_IS || pExpr->op==TK_ISNOT
641 || pExpr->op==TK_LT || pExpr->op==TK_GT
642 || pExpr->op==TK_LE || pExpr->op==TK_GE
643 );
644 assert( pExpr->op==op || (pExpr->op==TK_IS && op==TK_EQ)
645 || (pExpr->op==TK_ISNOT && op==TK_NE) );
646 assert( p5==0 || pExpr->op!=op );
647 assert( p5==SQLITE_NULLEQ || pExpr->op==op );
648
649 if( op==TK_LE ) opx = TK_LT;
650 if( op==TK_GE ) opx = TK_GT;
651 if( op==TK_NE ) opx = TK_EQ;
652
653 regLeft = exprCodeSubselect(pParse, pLeft);
654 regRight = exprCodeSubselect(pParse, pRight);
655
656 sqlite3VdbeAddOp2(v, OP_Integer, 1, dest);
657 for(i=0; 1 /*Loop exits by "break"*/; i++){
658 int regFree1 = 0, regFree2 = 0;
659 Expr *pL = 0, *pR = 0;
660 int r1, r2;
661 assert( i>=0 && i<nLeft );
662 if( addrCmp ) sqlite3VdbeJumpHere(v, addrCmp);
663 r1 = exprVectorRegister(pParse, pLeft, i, regLeft, &pL, &regFree1);
664 r2 = exprVectorRegister(pParse, pRight, i, regRight, &pR, &regFree2);
665 addrCmp = sqlite3VdbeCurrentAddr(v);
666 codeCompare(pParse, pL, pR, opx, r1, r2, addrDone, p5, isCommuted);
667 testcase(op==OP_Lt); VdbeCoverageIf(v,op==OP_Lt);
668 testcase(op==OP_Le); VdbeCoverageIf(v,op==OP_Le);
669 testcase(op==OP_Gt); VdbeCoverageIf(v,op==OP_Gt);
670 testcase(op==OP_Ge); VdbeCoverageIf(v,op==OP_Ge);
671 testcase(op==OP_Eq); VdbeCoverageIf(v,op==OP_Eq);
672 testcase(op==OP_Ne); VdbeCoverageIf(v,op==OP_Ne);
673 sqlite3ReleaseTempReg(pParse, regFree1);
674 sqlite3ReleaseTempReg(pParse, regFree2);
675 if( (opx==TK_LT || opx==TK_GT) && i<nLeft-1 ){
676 addrCmp = sqlite3VdbeAddOp0(v, OP_ElseEq);
677 testcase(opx==TK_LT); VdbeCoverageIf(v,opx==TK_LT);
678 testcase(opx==TK_GT); VdbeCoverageIf(v,opx==TK_GT);
679 }
680 if( p5==SQLITE_NULLEQ ){
681 sqlite3VdbeAddOp2(v, OP_Integer, 0, dest);
682 }else{
683 sqlite3VdbeAddOp3(v, OP_ZeroOrNull, r1, dest, r2);
684 }
685 if( i==nLeft-1 ){
686 break;
687 }
688 if( opx==TK_EQ ){
689 sqlite3VdbeAddOp2(v, OP_NotNull, dest, addrDone); VdbeCoverage(v);
690 }else{
691 assert( op==TK_LT || op==TK_GT || op==TK_LE || op==TK_GE );
692 sqlite3VdbeAddOp2(v, OP_Goto, 0, addrDone);
693 if( i==nLeft-2 ) opx = op;
694 }
695 }
696 sqlite3VdbeJumpHere(v, addrCmp);
697 sqlite3VdbeResolveLabel(v, addrDone);
698 if( op==TK_NE ){
699 sqlite3VdbeAddOp2(v, OP_Not, dest, dest);
700 }
701}
702
703#if SQLITE_MAX_EXPR_DEPTH>0
704/*
705** Check that argument nHeight is less than or equal to the maximum
706** expression depth allowed. If it is not, leave an error message in
707** pParse.
708*/
709int sqlite3ExprCheckHeight(Parse *pParse, int nHeight){
710 int rc = SQLITE_OK;
711 int mxHeight = pParse->db->aLimit[SQLITE_LIMIT_EXPR_DEPTH];
712 if( nHeight>mxHeight ){
713 sqlite3ErrorMsg(pParse,
714 "Expression tree is too large (maximum depth %d)", mxHeight
715 );
716 rc = SQLITE_ERROR;
717 }
718 return rc;
719}
720
721/* The following three functions, heightOfExpr(), heightOfExprList()
722** and heightOfSelect(), are used to determine the maximum height
723** of any expression tree referenced by the structure passed as the
724** first argument.
725**
726** If this maximum height is greater than the current value pointed
727** to by pnHeight, the second parameter, then set *pnHeight to that
728** value.
729*/
730static void heightOfExpr(const Expr *p, int *pnHeight){
731 if( p ){
732 if( p->nHeight>*pnHeight ){
733 *pnHeight = p->nHeight;
734 }
735 }
736}
737static void heightOfExprList(const ExprList *p, int *pnHeight){
738 if( p ){
739 int i;
740 for(i=0; i<p->nExpr; i++){
741 heightOfExpr(p->a[i].pExpr, pnHeight);
742 }
743 }
744}
745static void heightOfSelect(const Select *pSelect, int *pnHeight){
746 const Select *p;
747 for(p=pSelect; p; p=p->pPrior){
748 heightOfExpr(p->pWhere, pnHeight);
749 heightOfExpr(p->pHaving, pnHeight);
750 heightOfExpr(p->pLimit, pnHeight);
751 heightOfExprList(p->pEList, pnHeight);
752 heightOfExprList(p->pGroupBy, pnHeight);
753 heightOfExprList(p->pOrderBy, pnHeight);
754 }
755}
756
757/*
758** Set the Expr.nHeight variable in the structure passed as an
759** argument. An expression with no children, Expr.pList or
760** Expr.pSelect member has a height of 1. Any other expression
761** has a height equal to the maximum height of any other
762** referenced Expr plus one.
763**
764** Also propagate EP_Propagate flags up from Expr.x.pList to Expr.flags,
765** if appropriate.
766*/
767static void exprSetHeight(Expr *p){
768 int nHeight = p->pLeft ? p->pLeft->nHeight : 0;
769 if( NEVER(p->pRight) && p->pRight->nHeight>nHeight ){
770 nHeight = p->pRight->nHeight;
771 }
772 if( ExprUseXSelect(p) ){
773 heightOfSelect(p->x.pSelect, &nHeight);
774 }else if( p->x.pList ){
775 heightOfExprList(p->x.pList, &nHeight);
776 p->flags |= EP_Propagate & sqlite3ExprListFlags(p->x.pList);
777 }
778 p->nHeight = nHeight + 1;
779}
780
781/*
782** Set the Expr.nHeight variable using the exprSetHeight() function. If
783** the height is greater than the maximum allowed expression depth,
784** leave an error in pParse.
785**
786** Also propagate all EP_Propagate flags from the Expr.x.pList into
787** Expr.flags.
788*/
789void sqlite3ExprSetHeightAndFlags(Parse *pParse, Expr *p){
790 if( pParse->nErr ) return;
791 exprSetHeight(p);
792 sqlite3ExprCheckHeight(pParse, p->nHeight);
793}
794
795/*
796** Return the maximum height of any expression tree referenced
797** by the select statement passed as an argument.
798*/
799int sqlite3SelectExprHeight(const Select *p){
800 int nHeight = 0;
801 heightOfSelect(p, &nHeight);
802 return nHeight;
803}
804#else /* ABOVE: Height enforcement enabled. BELOW: Height enforcement off */
805/*
806** Propagate all EP_Propagate flags from the Expr.x.pList into
807** Expr.flags.
808*/
809void sqlite3ExprSetHeightAndFlags(Parse *pParse, Expr *p){
810 if( pParse->nErr ) return;
811 if( p && ExprUseXList(p) && p->x.pList ){
812 p->flags |= EP_Propagate & sqlite3ExprListFlags(p->x.pList);
813 }
814}
815#define exprSetHeight(y)
816#endif /* SQLITE_MAX_EXPR_DEPTH>0 */
817
818/*
819** This routine is the core allocator for Expr nodes.
820**
821** Construct a new expression node and return a pointer to it. Memory
822** for this node and for the pToken argument is a single allocation
823** obtained from sqlite3DbMalloc(). The calling function
824** is responsible for making sure the node eventually gets freed.
825**
826** If dequote is true, then the token (if it exists) is dequoted.
827** If dequote is false, no dequoting is performed. The deQuote
828** parameter is ignored if pToken is NULL or if the token does not
829** appear to be quoted. If the quotes were of the form "..." (double-quotes)
830** then the EP_DblQuoted flag is set on the expression node.
831**
832** Special case: If op==TK_INTEGER and pToken points to a string that
833** can be translated into a 32-bit integer, then the token is not
834** stored in u.zToken. Instead, the integer values is written
835** into u.iValue and the EP_IntValue flag is set. No extra storage
836** is allocated to hold the integer text and the dequote flag is ignored.
837*/
838Expr *sqlite3ExprAlloc(
839 sqlite3 *db, /* Handle for sqlite3DbMallocRawNN() */
840 int op, /* Expression opcode */
841 const Token *pToken, /* Token argument. Might be NULL */
842 int dequote /* True to dequote */
843){
844 Expr *pNew;
845 int nExtra = 0;
846 int iValue = 0;
847
848 assert( db!=0 );
849 if( pToken ){
850 if( op!=TK_INTEGER || pToken->z==0
851 || sqlite3GetInt32(pToken->z, &iValue)==0 ){
852 nExtra = pToken->n+1;
853 assert( iValue>=0 );
854 }
855 }
856 pNew = sqlite3DbMallocRawNN(db, sizeof(Expr)+nExtra);
857 if( pNew ){
858 memset(pNew, 0, sizeof(Expr));
859 pNew->op = (u8)op;
860 pNew->iAgg = -1;
861 if( pToken ){
862 if( nExtra==0 ){
863 pNew->flags |= EP_IntValue|EP_Leaf|(iValue?EP_IsTrue:EP_IsFalse);
864 pNew->u.iValue = iValue;
865 }else{
866 pNew->u.zToken = (char*)&pNew[1];
867 assert( pToken->z!=0 || pToken->n==0 );
868 if( pToken->n ) memcpy(pNew->u.zToken, pToken->z, pToken->n);
869 pNew->u.zToken[pToken->n] = 0;
870 if( dequote && sqlite3Isquote(pNew->u.zToken[0]) ){
871 sqlite3DequoteExpr(pNew);
872 }
873 }
874 }
875#if SQLITE_MAX_EXPR_DEPTH>0
876 pNew->nHeight = 1;
877#endif
878 }
879 return pNew;
880}
881
882/*
883** Allocate a new expression node from a zero-terminated token that has
884** already been dequoted.
885*/
886Expr *sqlite3Expr(
887 sqlite3 *db, /* Handle for sqlite3DbMallocZero() (may be null) */
888 int op, /* Expression opcode */
889 const char *zToken /* Token argument. Might be NULL */
890){
891 Token x;
892 x.z = zToken;
893 x.n = sqlite3Strlen30(zToken);
894 return sqlite3ExprAlloc(db, op, &x, 0);
895}
896
897/*
898** Attach subtrees pLeft and pRight to the Expr node pRoot.
899**
900** If pRoot==NULL that means that a memory allocation error has occurred.
901** In that case, delete the subtrees pLeft and pRight.
902*/
903void sqlite3ExprAttachSubtrees(
904 sqlite3 *db,
905 Expr *pRoot,
906 Expr *pLeft,
907 Expr *pRight
908){
909 if( pRoot==0 ){
910 assert( db->mallocFailed );
911 sqlite3ExprDelete(db, pLeft);
912 sqlite3ExprDelete(db, pRight);
913 }else{
914 assert( ExprUseXList(pRoot) );
915 assert( pRoot->x.pSelect==0 );
916 if( pRight ){
917 pRoot->pRight = pRight;
918 pRoot->flags |= EP_Propagate & pRight->flags;
919#if SQLITE_MAX_EXPR_DEPTH>0
920 pRoot->nHeight = pRight->nHeight+1;
921 }else{
922 pRoot->nHeight = 1;
923#endif
924 }
925 if( pLeft ){
926 pRoot->pLeft = pLeft;
927 pRoot->flags |= EP_Propagate & pLeft->flags;
928#if SQLITE_MAX_EXPR_DEPTH>0
929 if( pLeft->nHeight>=pRoot->nHeight ){
930 pRoot->nHeight = pLeft->nHeight+1;
931 }
932#endif
933 }
934 }
935}
936
937/*
938** Allocate an Expr node which joins as many as two subtrees.
939**
940** One or both of the subtrees can be NULL. Return a pointer to the new
941** Expr node. Or, if an OOM error occurs, set pParse->db->mallocFailed,
942** free the subtrees and return NULL.
943*/
944Expr *sqlite3PExpr(
945 Parse *pParse, /* Parsing context */
946 int op, /* Expression opcode */
947 Expr *pLeft, /* Left operand */
948 Expr *pRight /* Right operand */
949){
950 Expr *p;
951 p = sqlite3DbMallocRawNN(pParse->db, sizeof(Expr));
952 if( p ){
953 memset(p, 0, sizeof(Expr));
954 p->op = op & 0xff;
955 p->iAgg = -1;
956 sqlite3ExprAttachSubtrees(pParse->db, p, pLeft, pRight);
957 sqlite3ExprCheckHeight(pParse, p->nHeight);
958 }else{
959 sqlite3ExprDelete(pParse->db, pLeft);
960 sqlite3ExprDelete(pParse->db, pRight);
961 }
962 return p;
963}
964
965/*
966** Add pSelect to the Expr.x.pSelect field. Or, if pExpr is NULL (due
967** do a memory allocation failure) then delete the pSelect object.
968*/
969void sqlite3PExprAddSelect(Parse *pParse, Expr *pExpr, Select *pSelect){
970 if( pExpr ){
971 pExpr->x.pSelect = pSelect;
972 ExprSetProperty(pExpr, EP_xIsSelect|EP_Subquery);
973 sqlite3ExprSetHeightAndFlags(pParse, pExpr);
974 }else{
975 assert( pParse->db->mallocFailed );
976 sqlite3SelectDelete(pParse->db, pSelect);
977 }
978}
979
980/*
981** Expression list pEList is a list of vector values. This function
982** converts the contents of pEList to a VALUES(...) Select statement
983** returning 1 row for each element of the list. For example, the
984** expression list:
985**
986** ( (1,2), (3,4) (5,6) )
987**
988** is translated to the equivalent of:
989**
990** VALUES(1,2), (3,4), (5,6)
991**
992** Each of the vector values in pEList must contain exactly nElem terms.
993** If a list element that is not a vector or does not contain nElem terms,
994** an error message is left in pParse.
995**
996** This is used as part of processing IN(...) expressions with a list
997** of vectors on the RHS. e.g. "... IN ((1,2), (3,4), (5,6))".
998*/
999Select *sqlite3ExprListToValues(Parse *pParse, int nElem, ExprList *pEList){
1000 int ii;
1001 Select *pRet = 0;
1002 assert( nElem>1 );
1003 for(ii=0; ii<pEList->nExpr; ii++){
1004 Select *pSel;
1005 Expr *pExpr = pEList->a[ii].pExpr;
1006 int nExprElem;
1007 if( pExpr->op==TK_VECTOR ){
1008 assert( ExprUseXList(pExpr) );
1009 nExprElem = pExpr->x.pList->nExpr;
1010 }else{
1011 nExprElem = 1;
1012 }
1013 if( nExprElem!=nElem ){
1014 sqlite3ErrorMsg(pParse, "IN(...) element has %d term%s - expected %d",
1015 nExprElem, nExprElem>1?"s":"", nElem
1016 );
1017 break;
1018 }
1019 assert( ExprUseXList(pExpr) );
1020 pSel = sqlite3SelectNew(pParse, pExpr->x.pList, 0, 0, 0, 0, 0, SF_Values,0);
1021 pExpr->x.pList = 0;
1022 if( pSel ){
1023 if( pRet ){
1024 pSel->op = TK_ALL;
1025 pSel->pPrior = pRet;
1026 }
1027 pRet = pSel;
1028 }
1029 }
1030
1031 if( pRet && pRet->pPrior ){
1032 pRet->selFlags |= SF_MultiValue;
1033 }
1034 sqlite3ExprListDelete(pParse->db, pEList);
1035 return pRet;
1036}
1037
1038/*
1039** Join two expressions using an AND operator. If either expression is
1040** NULL, then just return the other expression.
1041**
1042** If one side or the other of the AND is known to be false, then instead
1043** of returning an AND expression, just return a constant expression with
1044** a value of false.
1045*/
1046Expr *sqlite3ExprAnd(Parse *pParse, Expr *pLeft, Expr *pRight){
1047 sqlite3 *db = pParse->db;
1048 if( pLeft==0 ){
1049 return pRight;
1050 }else if( pRight==0 ){
1051 return pLeft;
1052 }else if( (ExprAlwaysFalse(pLeft) || ExprAlwaysFalse(pRight))
1053 && !IN_RENAME_OBJECT
1054 ){
1055 sqlite3ExprDeferredDelete(pParse, pLeft);
1056 sqlite3ExprDeferredDelete(pParse, pRight);
1057 return sqlite3Expr(db, TK_INTEGER, "0");
1058 }else{
1059 return sqlite3PExpr(pParse, TK_AND, pLeft, pRight);
1060 }
1061}
1062
1063/*
1064** Construct a new expression node for a function with multiple
1065** arguments.
1066*/
1067Expr *sqlite3ExprFunction(
1068 Parse *pParse, /* Parsing context */
1069 ExprList *pList, /* Argument list */
1070 const Token *pToken, /* Name of the function */
1071 int eDistinct /* SF_Distinct or SF_ALL or 0 */
1072){
1073 Expr *pNew;
1074 sqlite3 *db = pParse->db;
1075 assert( pToken );
1076 pNew = sqlite3ExprAlloc(db, TK_FUNCTION, pToken, 1);
1077 if( pNew==0 ){
1078 sqlite3ExprListDelete(db, pList); /* Avoid memory leak when malloc fails */
1079 return 0;
1080 }
1081 assert( !ExprHasProperty(pNew, EP_InnerON|EP_OuterON) );
1082 pNew->w.iOfst = (int)(pToken->z - pParse->zTail);
1083 if( pList
1084 && pList->nExpr > pParse->db->aLimit[SQLITE_LIMIT_FUNCTION_ARG]
1085 && !pParse->nested
1086 ){
1087 sqlite3ErrorMsg(pParse, "too many arguments on function %T", pToken);
1088 }
1089 pNew->x.pList = pList;
1090 ExprSetProperty(pNew, EP_HasFunc);
1091 assert( ExprUseXList(pNew) );
1092 sqlite3ExprSetHeightAndFlags(pParse, pNew);
1093 if( eDistinct==SF_Distinct ) ExprSetProperty(pNew, EP_Distinct);
1094 return pNew;
1095}
1096
1097/*
1098** Check to see if a function is usable according to current access
1099** rules:
1100**
1101** SQLITE_FUNC_DIRECT - Only usable from top-level SQL
1102**
1103** SQLITE_FUNC_UNSAFE - Usable if TRUSTED_SCHEMA or from
1104** top-level SQL
1105**
1106** If the function is not usable, create an error.
1107*/
1108void sqlite3ExprFunctionUsable(
1109 Parse *pParse, /* Parsing and code generating context */
1110 const Expr *pExpr, /* The function invocation */
1111 const FuncDef *pDef /* The function being invoked */
1112){
1113 assert( !IN_RENAME_OBJECT );
1114 assert( (pDef->funcFlags & (SQLITE_FUNC_DIRECT|SQLITE_FUNC_UNSAFE))!=0 );
1115 if( ExprHasProperty(pExpr, EP_FromDDL) ){
1116 if( (pDef->funcFlags & SQLITE_FUNC_DIRECT)!=0
1117 || (pParse->db->flags & SQLITE_TrustedSchema)==0
1118 ){
1119 /* Functions prohibited in triggers and views if:
1120 ** (1) tagged with SQLITE_DIRECTONLY
1121 ** (2) not tagged with SQLITE_INNOCUOUS (which means it
1122 ** is tagged with SQLITE_FUNC_UNSAFE) and
1123 ** SQLITE_DBCONFIG_TRUSTED_SCHEMA is off (meaning
1124 ** that the schema is possibly tainted).
1125 */
1126 sqlite3ErrorMsg(pParse, "unsafe use of %#T()", pExpr);
1127 }
1128 }
1129}
1130
1131/*
1132** Assign a variable number to an expression that encodes a wildcard
1133** in the original SQL statement.
1134**
1135** Wildcards consisting of a single "?" are assigned the next sequential
1136** variable number.
1137**
1138** Wildcards of the form "?nnn" are assigned the number "nnn". We make
1139** sure "nnn" is not too big to avoid a denial of service attack when
1140** the SQL statement comes from an external source.
1141**
1142** Wildcards of the form ":aaa", "@aaa", or "$aaa" are assigned the same number
1143** as the previous instance of the same wildcard. Or if this is the first
1144** instance of the wildcard, the next sequential variable number is
1145** assigned.
1146*/
1147void sqlite3ExprAssignVarNumber(Parse *pParse, Expr *pExpr, u32 n){
1148 sqlite3 *db = pParse->db;
1149 const char *z;
1150 ynVar x;
1151
1152 if( pExpr==0 ) return;
1153 assert( !ExprHasProperty(pExpr, EP_IntValue|EP_Reduced|EP_TokenOnly) );
1154 z = pExpr->u.zToken;
1155 assert( z!=0 );
1156 assert( z[0]!=0 );
1157 assert( n==(u32)sqlite3Strlen30(z) );
1158 if( z[1]==0 ){
1159 /* Wildcard of the form "?". Assign the next variable number */
1160 assert( z[0]=='?' );
1161 x = (ynVar)(++pParse->nVar);
1162 }else{
1163 int doAdd = 0;
1164 if( z[0]=='?' ){
1165 /* Wildcard of the form "?nnn". Convert "nnn" to an integer and
1166 ** use it as the variable number */
1167 i64 i;
1168 int bOk;
1169 if( n==2 ){ /*OPTIMIZATION-IF-TRUE*/
1170 i = z[1]-'0'; /* The common case of ?N for a single digit N */
1171 bOk = 1;
1172 }else{
1173 bOk = 0==sqlite3Atoi64(&z[1], &i, n-1, SQLITE_UTF8);
1174 }
1175 testcase( i==0 );
1176 testcase( i==1 );
1177 testcase( i==db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER]-1 );
1178 testcase( i==db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER] );
1179 if( bOk==0 || i<1 || i>db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER] ){
1180 sqlite3ErrorMsg(pParse, "variable number must be between ?1 and ?%d",
1181 db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER]);
1182 sqlite3RecordErrorOffsetOfExpr(pParse->db, pExpr);
1183 return;
1184 }
1185 x = (ynVar)i;
1186 if( x>pParse->nVar ){
1187 pParse->nVar = (int)x;
1188 doAdd = 1;
1189 }else if( sqlite3VListNumToName(pParse->pVList, x)==0 ){
1190 doAdd = 1;
1191 }
1192 }else{
1193 /* Wildcards like ":aaa", "$aaa" or "@aaa". Reuse the same variable
1194 ** number as the prior appearance of the same name, or if the name
1195 ** has never appeared before, reuse the same variable number
1196 */
1197 x = (ynVar)sqlite3VListNameToNum(pParse->pVList, z, n);
1198 if( x==0 ){
1199 x = (ynVar)(++pParse->nVar);
1200 doAdd = 1;
1201 }
1202 }
1203 if( doAdd ){
1204 pParse->pVList = sqlite3VListAdd(db, pParse->pVList, z, n, x);
1205 }
1206 }
1207 pExpr->iColumn = x;
1208 if( x>db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER] ){
1209 sqlite3ErrorMsg(pParse, "too many SQL variables");
1210 sqlite3RecordErrorOffsetOfExpr(pParse->db, pExpr);
1211 }
1212}
1213
1214/*
1215** Recursively delete an expression tree.
1216*/
1217static SQLITE_NOINLINE void sqlite3ExprDeleteNN(sqlite3 *db, Expr *p){
1218 assert( p!=0 );
1219 assert( db!=0 );
1220 assert( !ExprUseUValue(p) || p->u.iValue>=0 );
1221 assert( !ExprUseYWin(p) || !ExprUseYSub(p) );
1222 assert( !ExprUseYWin(p) || p->y.pWin!=0 || db->mallocFailed );
1223 assert( p->op!=TK_FUNCTION || !ExprUseYSub(p) );
1224#ifdef SQLITE_DEBUG
1225 if( ExprHasProperty(p, EP_Leaf) && !ExprHasProperty(p, EP_TokenOnly) ){
1226 assert( p->pLeft==0 );
1227 assert( p->pRight==0 );
1228 assert( !ExprUseXSelect(p) || p->x.pSelect==0 );
1229 assert( !ExprUseXList(p) || p->x.pList==0 );
1230 }
1231#endif
1232 if( !ExprHasProperty(p, (EP_TokenOnly|EP_Leaf)) ){
1233 /* The Expr.x union is never used at the same time as Expr.pRight */
1234 assert( (ExprUseXList(p) && p->x.pList==0) || p->pRight==0 );
1235 if( p->pLeft && p->op!=TK_SELECT_COLUMN ) sqlite3ExprDeleteNN(db, p->pLeft);
1236 if( p->pRight ){
1237 assert( !ExprHasProperty(p, EP_WinFunc) );
1238 sqlite3ExprDeleteNN(db, p->pRight);
1239 }else if( ExprUseXSelect(p) ){
1240 assert( !ExprHasProperty(p, EP_WinFunc) );
1241 sqlite3SelectDelete(db, p->x.pSelect);
1242 }else{
1243 sqlite3ExprListDelete(db, p->x.pList);
1244#ifndef SQLITE_OMIT_WINDOWFUNC
1245 if( ExprHasProperty(p, EP_WinFunc) ){
1246 sqlite3WindowDelete(db, p->y.pWin);
1247 }
1248#endif
1249 }
1250 }
1251 if( !ExprHasProperty(p, EP_Static) ){
1252 sqlite3DbNNFreeNN(db, p);
1253 }
1254}
1255void sqlite3ExprDelete(sqlite3 *db, Expr *p){
1256 if( p ) sqlite3ExprDeleteNN(db, p);
1257}
1258
1259/*
1260** Clear both elements of an OnOrUsing object
1261*/
1262void sqlite3ClearOnOrUsing(sqlite3 *db, OnOrUsing *p){
1263 if( p==0 ){
1264 /* Nothing to clear */
1265 }else if( p->pOn ){
1266 sqlite3ExprDeleteNN(db, p->pOn);
1267 }else if( p->pUsing ){
1268 sqlite3IdListDelete(db, p->pUsing);
1269 }
1270}
1271
1272/*
1273** Arrange to cause pExpr to be deleted when the pParse is deleted.
1274** This is similar to sqlite3ExprDelete() except that the delete is
1275** deferred untilthe pParse is deleted.
1276**
1277** The pExpr might be deleted immediately on an OOM error.
1278**
1279** The deferred delete is (currently) implemented by adding the
1280** pExpr to the pParse->pConstExpr list with a register number of 0.
1281*/
1282void sqlite3ExprDeferredDelete(Parse *pParse, Expr *pExpr){
1283 sqlite3ParserAddCleanup(pParse,
1284 (void(*)(sqlite3*,void*))sqlite3ExprDelete,
1285 pExpr);
1286}
1287
1288/* Invoke sqlite3RenameExprUnmap() and sqlite3ExprDelete() on the
1289** expression.
1290*/
1291void sqlite3ExprUnmapAndDelete(Parse *pParse, Expr *p){
1292 if( p ){
1293 if( IN_RENAME_OBJECT ){
1294 sqlite3RenameExprUnmap(pParse, p);
1295 }
1296 sqlite3ExprDeleteNN(pParse->db, p);
1297 }
1298}
1299
1300/*
1301** Return the number of bytes allocated for the expression structure
1302** passed as the first argument. This is always one of EXPR_FULLSIZE,
1303** EXPR_REDUCEDSIZE or EXPR_TOKENONLYSIZE.
1304*/
1305static int exprStructSize(const Expr *p){
1306 if( ExprHasProperty(p, EP_TokenOnly) ) return EXPR_TOKENONLYSIZE;
1307 if( ExprHasProperty(p, EP_Reduced) ) return EXPR_REDUCEDSIZE;
1308 return EXPR_FULLSIZE;
1309}
1310
1311/*
1312** The dupedExpr*Size() routines each return the number of bytes required
1313** to store a copy of an expression or expression tree. They differ in
1314** how much of the tree is measured.
1315**
1316** dupedExprStructSize() Size of only the Expr structure
1317** dupedExprNodeSize() Size of Expr + space for token
1318** dupedExprSize() Expr + token + subtree components
1319**
1320***************************************************************************
1321**
1322** The dupedExprStructSize() function returns two values OR-ed together:
1323** (1) the space required for a copy of the Expr structure only and
1324** (2) the EP_xxx flags that indicate what the structure size should be.
1325** The return values is always one of:
1326**
1327** EXPR_FULLSIZE
1328** EXPR_REDUCEDSIZE | EP_Reduced
1329** EXPR_TOKENONLYSIZE | EP_TokenOnly
1330**
1331** The size of the structure can be found by masking the return value
1332** of this routine with 0xfff. The flags can be found by masking the
1333** return value with EP_Reduced|EP_TokenOnly.
1334**
1335** Note that with flags==EXPRDUP_REDUCE, this routines works on full-size
1336** (unreduced) Expr objects as they or originally constructed by the parser.
1337** During expression analysis, extra information is computed and moved into
1338** later parts of the Expr object and that extra information might get chopped
1339** off if the expression is reduced. Note also that it does not work to
1340** make an EXPRDUP_REDUCE copy of a reduced expression. It is only legal
1341** to reduce a pristine expression tree from the parser. The implementation
1342** of dupedExprStructSize() contain multiple assert() statements that attempt
1343** to enforce this constraint.
1344*/
1345static int dupedExprStructSize(const Expr *p, int flags){
1346 int nSize;
1347 assert( flags==EXPRDUP_REDUCE || flags==0 ); /* Only one flag value allowed */
1348 assert( EXPR_FULLSIZE<=0xfff );
1349 assert( (0xfff & (EP_Reduced|EP_TokenOnly))==0 );
1350 if( 0==flags || p->op==TK_SELECT_COLUMN
1351#ifndef SQLITE_OMIT_WINDOWFUNC
1352 || ExprHasProperty(p, EP_WinFunc)
1353#endif
1354 ){
1355 nSize = EXPR_FULLSIZE;
1356 }else{
1357 assert( !ExprHasProperty(p, EP_TokenOnly|EP_Reduced) );
1358 assert( !ExprHasProperty(p, EP_OuterON) );
1359 assert( !ExprHasVVAProperty(p, EP_NoReduce) );
1360 if( p->pLeft || p->x.pList ){
1361 nSize = EXPR_REDUCEDSIZE | EP_Reduced;
1362 }else{
1363 assert( p->pRight==0 );
1364 nSize = EXPR_TOKENONLYSIZE | EP_TokenOnly;
1365 }
1366 }
1367 return nSize;
1368}
1369
1370/*
1371** This function returns the space in bytes required to store the copy
1372** of the Expr structure and a copy of the Expr.u.zToken string (if that
1373** string is defined.)
1374*/
1375static int dupedExprNodeSize(const Expr *p, int flags){
1376 int nByte = dupedExprStructSize(p, flags) & 0xfff;
1377 if( !ExprHasProperty(p, EP_IntValue) && p->u.zToken ){
1378 nByte += sqlite3Strlen30NN(p->u.zToken)+1;
1379 }
1380 return ROUND8(nByte);
1381}
1382
1383/*
1384** Return the number of bytes required to create a duplicate of the
1385** expression passed as the first argument. The second argument is a
1386** mask containing EXPRDUP_XXX flags.
1387**
1388** The value returned includes space to create a copy of the Expr struct
1389** itself and the buffer referred to by Expr.u.zToken, if any.
1390**
1391** If the EXPRDUP_REDUCE flag is set, then the return value includes
1392** space to duplicate all Expr nodes in the tree formed by Expr.pLeft
1393** and Expr.pRight variables (but not for any structures pointed to or
1394** descended from the Expr.x.pList or Expr.x.pSelect variables).
1395*/
1396static int dupedExprSize(const Expr *p, int flags){
1397 int nByte = 0;
1398 if( p ){
1399 nByte = dupedExprNodeSize(p, flags);
1400 if( flags&EXPRDUP_REDUCE ){
1401 nByte += dupedExprSize(p->pLeft, flags) + dupedExprSize(p->pRight, flags);
1402 }
1403 }
1404 return nByte;
1405}
1406
1407/*
1408** This function is similar to sqlite3ExprDup(), except that if pzBuffer
1409** is not NULL then *pzBuffer is assumed to point to a buffer large enough
1410** to store the copy of expression p, the copies of p->u.zToken
1411** (if applicable), and the copies of the p->pLeft and p->pRight expressions,
1412** if any. Before returning, *pzBuffer is set to the first byte past the
1413** portion of the buffer copied into by this function.
1414*/
1415static Expr *exprDup(sqlite3 *db, const Expr *p, int dupFlags, u8 **pzBuffer){
1416 Expr *pNew; /* Value to return */
1417 u8 *zAlloc; /* Memory space from which to build Expr object */
1418 u32 staticFlag; /* EP_Static if space not obtained from malloc */
1419
1420 assert( db!=0 );
1421 assert( p );
1422 assert( dupFlags==0 || dupFlags==EXPRDUP_REDUCE );
1423 assert( pzBuffer==0 || dupFlags==EXPRDUP_REDUCE );
1424
1425 /* Figure out where to write the new Expr structure. */
1426 if( pzBuffer ){
1427 zAlloc = *pzBuffer;
1428 staticFlag = EP_Static;
1429 assert( zAlloc!=0 );
1430 }else{
1431 zAlloc = sqlite3DbMallocRawNN(db, dupedExprSize(p, dupFlags));
1432 staticFlag = 0;
1433 }
1434 pNew = (Expr *)zAlloc;
1435
1436 if( pNew ){
1437 /* Set nNewSize to the size allocated for the structure pointed to
1438 ** by pNew. This is either EXPR_FULLSIZE, EXPR_REDUCEDSIZE or
1439 ** EXPR_TOKENONLYSIZE. nToken is set to the number of bytes consumed
1440 ** by the copy of the p->u.zToken string (if any).
1441 */
1442 const unsigned nStructSize = dupedExprStructSize(p, dupFlags);
1443 const int nNewSize = nStructSize & 0xfff;
1444 int nToken;
1445 if( !ExprHasProperty(p, EP_IntValue) && p->u.zToken ){
1446 nToken = sqlite3Strlen30(p->u.zToken) + 1;
1447 }else{
1448 nToken = 0;
1449 }
1450 if( dupFlags ){
1451 assert( ExprHasProperty(p, EP_Reduced)==0 );
1452 memcpy(zAlloc, p, nNewSize);
1453 }else{
1454 u32 nSize = (u32)exprStructSize(p);
1455 memcpy(zAlloc, p, nSize);
1456 if( nSize<EXPR_FULLSIZE ){
1457 memset(&zAlloc[nSize], 0, EXPR_FULLSIZE-nSize);
1458 }
1459 }
1460
1461 /* Set the EP_Reduced, EP_TokenOnly, and EP_Static flags appropriately. */
1462 pNew->flags &= ~(EP_Reduced|EP_TokenOnly|EP_Static);
1463 pNew->flags |= nStructSize & (EP_Reduced|EP_TokenOnly);
1464 pNew->flags |= staticFlag;
1465 ExprClearVVAProperties(pNew);
1466 if( dupFlags ){
1467 ExprSetVVAProperty(pNew, EP_Immutable);
1468 }
1469
1470 /* Copy the p->u.zToken string, if any. */
1471 if( nToken ){
1472 char *zToken = pNew->u.zToken = (char*)&zAlloc[nNewSize];
1473 memcpy(zToken, p->u.zToken, nToken);
1474 }
1475
1476 if( 0==((p->flags|pNew->flags) & (EP_TokenOnly|EP_Leaf)) ){
1477 /* Fill in the pNew->x.pSelect or pNew->x.pList member. */
1478 if( ExprUseXSelect(p) ){
1479 pNew->x.pSelect = sqlite3SelectDup(db, p->x.pSelect, dupFlags);
1480 }else{
1481 pNew->x.pList = sqlite3ExprListDup(db, p->x.pList, dupFlags);
1482 }
1483 }
1484
1485 /* Fill in pNew->pLeft and pNew->pRight. */
1486 if( ExprHasProperty(pNew, EP_Reduced|EP_TokenOnly|EP_WinFunc) ){
1487 zAlloc += dupedExprNodeSize(p, dupFlags);
1488 if( !ExprHasProperty(pNew, EP_TokenOnly|EP_Leaf) ){
1489 pNew->pLeft = p->pLeft ?
1490 exprDup(db, p->pLeft, EXPRDUP_REDUCE, &zAlloc) : 0;
1491 pNew->pRight = p->pRight ?
1492 exprDup(db, p->pRight, EXPRDUP_REDUCE, &zAlloc) : 0;
1493 }
1494#ifndef SQLITE_OMIT_WINDOWFUNC
1495 if( ExprHasProperty(p, EP_WinFunc) ){
1496 pNew->y.pWin = sqlite3WindowDup(db, pNew, p->y.pWin);
1497 assert( ExprHasProperty(pNew, EP_WinFunc) );
1498 }
1499#endif /* SQLITE_OMIT_WINDOWFUNC */
1500 if( pzBuffer ){
1501 *pzBuffer = zAlloc;
1502 }
1503 }else{
1504 if( !ExprHasProperty(p, EP_TokenOnly|EP_Leaf) ){
1505 if( pNew->op==TK_SELECT_COLUMN ){
1506 pNew->pLeft = p->pLeft;
1507 assert( p->pRight==0 || p->pRight==p->pLeft
1508 || ExprHasProperty(p->pLeft, EP_Subquery) );
1509 }else{
1510 pNew->pLeft = sqlite3ExprDup(db, p->pLeft, 0);
1511 }
1512 pNew->pRight = sqlite3ExprDup(db, p->pRight, 0);
1513 }
1514 }
1515 }
1516 return pNew;
1517}
1518
1519/*
1520** Create and return a deep copy of the object passed as the second
1521** argument. If an OOM condition is encountered, NULL is returned
1522** and the db->mallocFailed flag set.
1523*/
1524#ifndef SQLITE_OMIT_CTE
1525With *sqlite3WithDup(sqlite3 *db, With *p){
1526 With *pRet = 0;
1527 if( p ){
1528 sqlite3_int64 nByte = sizeof(*p) + sizeof(p->a[0]) * (p->nCte-1);
1529 pRet = sqlite3DbMallocZero(db, nByte);
1530 if( pRet ){
1531 int i;
1532 pRet->nCte = p->nCte;
1533 for(i=0; i<p->nCte; i++){
1534 pRet->a[i].pSelect = sqlite3SelectDup(db, p->a[i].pSelect, 0);
1535 pRet->a[i].pCols = sqlite3ExprListDup(db, p->a[i].pCols, 0);
1536 pRet->a[i].zName = sqlite3DbStrDup(db, p->a[i].zName);
1537 pRet->a[i].eM10d = p->a[i].eM10d;
1538 }
1539 }
1540 }
1541 return pRet;
1542}
1543#else
1544# define sqlite3WithDup(x,y) 0
1545#endif
1546
1547#ifndef SQLITE_OMIT_WINDOWFUNC
1548/*
1549** The gatherSelectWindows() procedure and its helper routine
1550** gatherSelectWindowsCallback() are used to scan all the expressions
1551** an a newly duplicated SELECT statement and gather all of the Window
1552** objects found there, assembling them onto the linked list at Select->pWin.
1553*/
1554static int gatherSelectWindowsCallback(Walker *pWalker, Expr *pExpr){
1555 if( pExpr->op==TK_FUNCTION && ExprHasProperty(pExpr, EP_WinFunc) ){
1556 Select *pSelect = pWalker->u.pSelect;
1557 Window *pWin = pExpr->y.pWin;
1558 assert( pWin );
1559 assert( IsWindowFunc(pExpr) );
1560 assert( pWin->ppThis==0 );
1561 sqlite3WindowLink(pSelect, pWin);
1562 }
1563 return WRC_Continue;
1564}
1565static int gatherSelectWindowsSelectCallback(Walker *pWalker, Select *p){
1566 return p==pWalker->u.pSelect ? WRC_Continue : WRC_Prune;
1567}
1568static void gatherSelectWindows(Select *p){
1569 Walker w;
1570 w.xExprCallback = gatherSelectWindowsCallback;
1571 w.xSelectCallback = gatherSelectWindowsSelectCallback;
1572 w.xSelectCallback2 = 0;
1573 w.pParse = 0;
1574 w.u.pSelect = p;
1575 sqlite3WalkSelect(&w, p);
1576}
1577#endif
1578
1579
1580/*
1581** The following group of routines make deep copies of expressions,
1582** expression lists, ID lists, and select statements. The copies can
1583** be deleted (by being passed to their respective ...Delete() routines)
1584** without effecting the originals.
1585**
1586** The expression list, ID, and source lists return by sqlite3ExprListDup(),
1587** sqlite3IdListDup(), and sqlite3SrcListDup() can not be further expanded
1588** by subsequent calls to sqlite*ListAppend() routines.
1589**
1590** Any tables that the SrcList might point to are not duplicated.
1591**
1592** The flags parameter contains a combination of the EXPRDUP_XXX flags.
1593** If the EXPRDUP_REDUCE flag is set, then the structure returned is a
1594** truncated version of the usual Expr structure that will be stored as
1595** part of the in-memory representation of the database schema.
1596*/
1597Expr *sqlite3ExprDup(sqlite3 *db, const Expr *p, int flags){
1598 assert( flags==0 || flags==EXPRDUP_REDUCE );
1599 return p ? exprDup(db, p, flags, 0) : 0;
1600}
1601ExprList *sqlite3ExprListDup(sqlite3 *db, const ExprList *p, int flags){
1602 ExprList *pNew;
1603 struct ExprList_item *pItem;
1604 const struct ExprList_item *pOldItem;
1605 int i;
1606 Expr *pPriorSelectColOld = 0;
1607 Expr *pPriorSelectColNew = 0;
1608 assert( db!=0 );
1609 if( p==0 ) return 0;
1610 pNew = sqlite3DbMallocRawNN(db, sqlite3DbMallocSize(db, p));
1611 if( pNew==0 ) return 0;
1612 pNew->nExpr = p->nExpr;
1613 pNew->nAlloc = p->nAlloc;
1614 pItem = pNew->a;
1615 pOldItem = p->a;
1616 for(i=0; i<p->nExpr; i++, pItem++, pOldItem++){
1617 Expr *pOldExpr = pOldItem->pExpr;
1618 Expr *pNewExpr;
1619 pItem->pExpr = sqlite3ExprDup(db, pOldExpr, flags);
1620 if( pOldExpr
1621 && pOldExpr->op==TK_SELECT_COLUMN
1622 && (pNewExpr = pItem->pExpr)!=0
1623 ){
1624 if( pNewExpr->pRight ){
1625 pPriorSelectColOld = pOldExpr->pRight;
1626 pPriorSelectColNew = pNewExpr->pRight;
1627 pNewExpr->pLeft = pNewExpr->pRight;
1628 }else{
1629 if( pOldExpr->pLeft!=pPriorSelectColOld ){
1630 pPriorSelectColOld = pOldExpr->pLeft;
1631 pPriorSelectColNew = sqlite3ExprDup(db, pPriorSelectColOld, flags);
1632 pNewExpr->pRight = pPriorSelectColNew;
1633 }
1634 pNewExpr->pLeft = pPriorSelectColNew;
1635 }
1636 }
1637 pItem->zEName = sqlite3DbStrDup(db, pOldItem->zEName);
1638 pItem->fg = pOldItem->fg;
1639 pItem->fg.done = 0;
1640 pItem->u = pOldItem->u;
1641 }
1642 return pNew;
1643}
1644
1645/*
1646** If cursors, triggers, views and subqueries are all omitted from
1647** the build, then none of the following routines, except for
1648** sqlite3SelectDup(), can be called. sqlite3SelectDup() is sometimes
1649** called with a NULL argument.
1650*/
1651#if !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_TRIGGER) \
1652 || !defined(SQLITE_OMIT_SUBQUERY)
1653SrcList *sqlite3SrcListDup(sqlite3 *db, const SrcList *p, int flags){
1654 SrcList *pNew;
1655 int i;
1656 int nByte;
1657 assert( db!=0 );
1658 if( p==0 ) return 0;
1659 nByte = sizeof(*p) + (p->nSrc>0 ? sizeof(p->a[0]) * (p->nSrc-1) : 0);
1660 pNew = sqlite3DbMallocRawNN(db, nByte );
1661 if( pNew==0 ) return 0;
1662 pNew->nSrc = pNew->nAlloc = p->nSrc;
1663 for(i=0; i<p->nSrc; i++){
1664 SrcItem *pNewItem = &pNew->a[i];
1665 const SrcItem *pOldItem = &p->a[i];
1666 Table *pTab;
1667 pNewItem->pSchema = pOldItem->pSchema;
1668 pNewItem->zDatabase = sqlite3DbStrDup(db, pOldItem->zDatabase);
1669 pNewItem->zName = sqlite3DbStrDup(db, pOldItem->zName);
1670 pNewItem->zAlias = sqlite3DbStrDup(db, pOldItem->zAlias);
1671 pNewItem->fg = pOldItem->fg;
1672 pNewItem->iCursor = pOldItem->iCursor;
1673 pNewItem->addrFillSub = pOldItem->addrFillSub;
1674 pNewItem->regReturn = pOldItem->regReturn;
1675 if( pNewItem->fg.isIndexedBy ){
1676 pNewItem->u1.zIndexedBy = sqlite3DbStrDup(db, pOldItem->u1.zIndexedBy);
1677 }
1678 pNewItem->u2 = pOldItem->u2;
1679 if( pNewItem->fg.isCte ){
1680 pNewItem->u2.pCteUse->nUse++;
1681 }
1682 if( pNewItem->fg.isTabFunc ){
1683 pNewItem->u1.pFuncArg =
1684 sqlite3ExprListDup(db, pOldItem->u1.pFuncArg, flags);
1685 }
1686 pTab = pNewItem->pTab = pOldItem->pTab;
1687 if( pTab ){
1688 pTab->nTabRef++;
1689 }
1690 pNewItem->pSelect = sqlite3SelectDup(db, pOldItem->pSelect, flags);
1691 if( pOldItem->fg.isUsing ){
1692 assert( pNewItem->fg.isUsing );
1693 pNewItem->u3.pUsing = sqlite3IdListDup(db, pOldItem->u3.pUsing);
1694 }else{
1695 pNewItem->u3.pOn = sqlite3ExprDup(db, pOldItem->u3.pOn, flags);
1696 }
1697 pNewItem->colUsed = pOldItem->colUsed;
1698 }
1699 return pNew;
1700}
1701IdList *sqlite3IdListDup(sqlite3 *db, const IdList *p){
1702 IdList *pNew;
1703 int i;
1704 assert( db!=0 );
1705 if( p==0 ) return 0;
1706 assert( p->eU4!=EU4_EXPR );
1707 pNew = sqlite3DbMallocRawNN(db, sizeof(*pNew)+(p->nId-1)*sizeof(p->a[0]) );
1708 if( pNew==0 ) return 0;
1709 pNew->nId = p->nId;
1710 pNew->eU4 = p->eU4;
1711 for(i=0; i<p->nId; i++){
1712 struct IdList_item *pNewItem = &pNew->a[i];
1713 const struct IdList_item *pOldItem = &p->a[i];
1714 pNewItem->zName = sqlite3DbStrDup(db, pOldItem->zName);
1715 pNewItem->u4 = pOldItem->u4;
1716 }
1717 return pNew;
1718}
1719Select *sqlite3SelectDup(sqlite3 *db, const Select *pDup, int flags){
1720 Select *pRet = 0;
1721 Select *pNext = 0;
1722 Select **pp = &pRet;
1723 const Select *p;
1724
1725 assert( db!=0 );
1726 for(p=pDup; p; p=p->pPrior){
1727 Select *pNew = sqlite3DbMallocRawNN(db, sizeof(*p) );
1728 if( pNew==0 ) break;
1729 pNew->pEList = sqlite3ExprListDup(db, p->pEList, flags);
1730 pNew->pSrc = sqlite3SrcListDup(db, p->pSrc, flags);
1731 pNew->pWhere = sqlite3ExprDup(db, p->pWhere, flags);
1732 pNew->pGroupBy = sqlite3ExprListDup(db, p->pGroupBy, flags);
1733 pNew->pHaving = sqlite3ExprDup(db, p->pHaving, flags);
1734 pNew->pOrderBy = sqlite3ExprListDup(db, p->pOrderBy, flags);
1735 pNew->op = p->op;
1736 pNew->pNext = pNext;
1737 pNew->pPrior = 0;
1738 pNew->pLimit = sqlite3ExprDup(db, p->pLimit, flags);
1739 pNew->iLimit = 0;
1740 pNew->iOffset = 0;
1741 pNew->selFlags = p->selFlags & ~SF_UsesEphemeral;
1742 pNew->addrOpenEphm[0] = -1;
1743 pNew->addrOpenEphm[1] = -1;
1744 pNew->nSelectRow = p->nSelectRow;
1745 pNew->pWith = sqlite3WithDup(db, p->pWith);
1746#ifndef SQLITE_OMIT_WINDOWFUNC
1747 pNew->pWin = 0;
1748 pNew->pWinDefn = sqlite3WindowListDup(db, p->pWinDefn);
1749 if( p->pWin && db->mallocFailed==0 ) gatherSelectWindows(pNew);
1750#endif
1751 pNew->selId = p->selId;
1752 if( db->mallocFailed ){
1753 /* Any prior OOM might have left the Select object incomplete.
1754 ** Delete the whole thing rather than allow an incomplete Select
1755 ** to be used by the code generator. */
1756 pNew->pNext = 0;
1757 sqlite3SelectDelete(db, pNew);
1758 break;
1759 }
1760 *pp = pNew;
1761 pp = &pNew->pPrior;
1762 pNext = pNew;
1763 }
1764
1765 return pRet;
1766}
1767#else
1768Select *sqlite3SelectDup(sqlite3 *db, const Select *p, int flags){
1769 assert( p==0 );
1770 return 0;
1771}
1772#endif
1773
1774
1775/*
1776** Add a new element to the end of an expression list. If pList is
1777** initially NULL, then create a new expression list.
1778**
1779** The pList argument must be either NULL or a pointer to an ExprList
1780** obtained from a prior call to sqlite3ExprListAppend(). This routine
1781** may not be used with an ExprList obtained from sqlite3ExprListDup().
1782** Reason: This routine assumes that the number of slots in pList->a[]
1783** is a power of two. That is true for sqlite3ExprListAppend() returns
1784** but is not necessarily true from the return value of sqlite3ExprListDup().
1785**
1786** If a memory allocation error occurs, the entire list is freed and
1787** NULL is returned. If non-NULL is returned, then it is guaranteed
1788** that the new entry was successfully appended.
1789*/
1790static const struct ExprList_item zeroItem = {0};
1791SQLITE_NOINLINE ExprList *sqlite3ExprListAppendNew(
1792 sqlite3 *db, /* Database handle. Used for memory allocation */
1793 Expr *pExpr /* Expression to be appended. Might be NULL */
1794){
1795 struct ExprList_item *pItem;
1796 ExprList *pList;
1797
1798 pList = sqlite3DbMallocRawNN(db, sizeof(ExprList)+sizeof(pList->a[0])*4 );
1799 if( pList==0 ){
1800 sqlite3ExprDelete(db, pExpr);
1801 return 0;
1802 }
1803 pList->nAlloc = 4;
1804 pList->nExpr = 1;
1805 pItem = &pList->a[0];
1806 *pItem = zeroItem;
1807 pItem->pExpr = pExpr;
1808 return pList;
1809}
1810SQLITE_NOINLINE ExprList *sqlite3ExprListAppendGrow(
1811 sqlite3 *db, /* Database handle. Used for memory allocation */
1812 ExprList *pList, /* List to which to append. Might be NULL */
1813 Expr *pExpr /* Expression to be appended. Might be NULL */
1814){
1815 struct ExprList_item *pItem;
1816 ExprList *pNew;
1817 pList->nAlloc *= 2;
1818 pNew = sqlite3DbRealloc(db, pList,
1819 sizeof(*pList)+(pList->nAlloc-1)*sizeof(pList->a[0]));
1820 if( pNew==0 ){
1821 sqlite3ExprListDelete(db, pList);
1822 sqlite3ExprDelete(db, pExpr);
1823 return 0;
1824 }else{
1825 pList = pNew;
1826 }
1827 pItem = &pList->a[pList->nExpr++];
1828 *pItem = zeroItem;
1829 pItem->pExpr = pExpr;
1830 return pList;
1831}
1832ExprList *sqlite3ExprListAppend(
1833 Parse *pParse, /* Parsing context */
1834 ExprList *pList, /* List to which to append. Might be NULL */
1835 Expr *pExpr /* Expression to be appended. Might be NULL */
1836){
1837 struct ExprList_item *pItem;
1838 if( pList==0 ){
1839 return sqlite3ExprListAppendNew(pParse->db,pExpr);
1840 }
1841 if( pList->nAlloc<pList->nExpr+1 ){
1842 return sqlite3ExprListAppendGrow(pParse->db,pList,pExpr);
1843 }
1844 pItem = &pList->a[pList->nExpr++];
1845 *pItem = zeroItem;
1846 pItem->pExpr = pExpr;
1847 return pList;
1848}
1849
1850/*
1851** pColumns and pExpr form a vector assignment which is part of the SET
1852** clause of an UPDATE statement. Like this:
1853**
1854** (a,b,c) = (expr1,expr2,expr3)
1855** Or: (a,b,c) = (SELECT x,y,z FROM ....)
1856**
1857** For each term of the vector assignment, append new entries to the
1858** expression list pList. In the case of a subquery on the RHS, append
1859** TK_SELECT_COLUMN expressions.
1860*/
1861ExprList *sqlite3ExprListAppendVector(
1862 Parse *pParse, /* Parsing context */
1863 ExprList *pList, /* List to which to append. Might be NULL */
1864 IdList *pColumns, /* List of names of LHS of the assignment */
1865 Expr *pExpr /* Vector expression to be appended. Might be NULL */
1866){
1867 sqlite3 *db = pParse->db;
1868 int n;
1869 int i;
1870 int iFirst = pList ? pList->nExpr : 0;
1871 /* pColumns can only be NULL due to an OOM but an OOM will cause an
1872 ** exit prior to this routine being invoked */
1873 if( NEVER(pColumns==0) ) goto vector_append_error;
1874 if( pExpr==0 ) goto vector_append_error;
1875
1876 /* If the RHS is a vector, then we can immediately check to see that
1877 ** the size of the RHS and LHS match. But if the RHS is a SELECT,
1878 ** wildcards ("*") in the result set of the SELECT must be expanded before
1879 ** we can do the size check, so defer the size check until code generation.
1880 */
1881 if( pExpr->op!=TK_SELECT && pColumns->nId!=(n=sqlite3ExprVectorSize(pExpr)) ){
1882 sqlite3ErrorMsg(pParse, "%d columns assigned %d values",
1883 pColumns->nId, n);
1884 goto vector_append_error;
1885 }
1886
1887 for(i=0; i<pColumns->nId; i++){
1888 Expr *pSubExpr = sqlite3ExprForVectorField(pParse, pExpr, i, pColumns->nId);
1889 assert( pSubExpr!=0 || db->mallocFailed );
1890 if( pSubExpr==0 ) continue;
1891 pList = sqlite3ExprListAppend(pParse, pList, pSubExpr);
1892 if( pList ){
1893 assert( pList->nExpr==iFirst+i+1 );
1894 pList->a[pList->nExpr-1].zEName = pColumns->a[i].zName;
1895 pColumns->a[i].zName = 0;
1896 }
1897 }
1898
1899 if( !db->mallocFailed && pExpr->op==TK_SELECT && ALWAYS(pList!=0) ){
1900 Expr *pFirst = pList->a[iFirst].pExpr;
1901 assert( pFirst!=0 );
1902 assert( pFirst->op==TK_SELECT_COLUMN );
1903
1904 /* Store the SELECT statement in pRight so it will be deleted when
1905 ** sqlite3ExprListDelete() is called */
1906 pFirst->pRight = pExpr;
1907 pExpr = 0;
1908
1909 /* Remember the size of the LHS in iTable so that we can check that
1910 ** the RHS and LHS sizes match during code generation. */
1911 pFirst->iTable = pColumns->nId;
1912 }
1913
1914vector_append_error:
1915 sqlite3ExprUnmapAndDelete(pParse, pExpr);
1916 sqlite3IdListDelete(db, pColumns);
1917 return pList;
1918}
1919
1920/*
1921** Set the sort order for the last element on the given ExprList.
1922*/
1923void sqlite3ExprListSetSortOrder(ExprList *p, int iSortOrder, int eNulls){
1924 struct ExprList_item *pItem;
1925 if( p==0 ) return;
1926 assert( p->nExpr>0 );
1927
1928 assert( SQLITE_SO_UNDEFINED<0 && SQLITE_SO_ASC==0 && SQLITE_SO_DESC>0 );
1929 assert( iSortOrder==SQLITE_SO_UNDEFINED
1930 || iSortOrder==SQLITE_SO_ASC
1931 || iSortOrder==SQLITE_SO_DESC
1932 );
1933 assert( eNulls==SQLITE_SO_UNDEFINED
1934 || eNulls==SQLITE_SO_ASC
1935 || eNulls==SQLITE_SO_DESC
1936 );
1937
1938 pItem = &p->a[p->nExpr-1];
1939 assert( pItem->fg.bNulls==0 );
1940 if( iSortOrder==SQLITE_SO_UNDEFINED ){
1941 iSortOrder = SQLITE_SO_ASC;
1942 }
1943 pItem->fg.sortFlags = (u8)iSortOrder;
1944
1945 if( eNulls!=SQLITE_SO_UNDEFINED ){
1946 pItem->fg.bNulls = 1;
1947 if( iSortOrder!=eNulls ){
1948 pItem->fg.sortFlags |= KEYINFO_ORDER_BIGNULL;
1949 }
1950 }
1951}
1952
1953/*
1954** Set the ExprList.a[].zEName element of the most recently added item
1955** on the expression list.
1956**
1957** pList might be NULL following an OOM error. But pName should never be
1958** NULL. If a memory allocation fails, the pParse->db->mallocFailed flag
1959** is set.
1960*/
1961void sqlite3ExprListSetName(
1962 Parse *pParse, /* Parsing context */
1963 ExprList *pList, /* List to which to add the span. */
1964 const Token *pName, /* Name to be added */
1965 int dequote /* True to cause the name to be dequoted */
1966){
1967 assert( pList!=0 || pParse->db->mallocFailed!=0 );
1968 assert( pParse->eParseMode!=PARSE_MODE_UNMAP || dequote==0 );
1969 if( pList ){
1970 struct ExprList_item *pItem;
1971 assert( pList->nExpr>0 );
1972 pItem = &pList->a[pList->nExpr-1];
1973 assert( pItem->zEName==0 );
1974 assert( pItem->fg.eEName==ENAME_NAME );
1975 pItem->zEName = sqlite3DbStrNDup(pParse->db, pName->z, pName->n);
1976 if( dequote ){
1977 /* If dequote==0, then pName->z does not point to part of a DDL
1978 ** statement handled by the parser. And so no token need be added
1979 ** to the token-map. */
1980 sqlite3Dequote(pItem->zEName);
1981 if( IN_RENAME_OBJECT ){
1982 sqlite3RenameTokenMap(pParse, (const void*)pItem->zEName, pName);
1983 }
1984 }
1985 }
1986}
1987
1988/*
1989** Set the ExprList.a[].zSpan element of the most recently added item
1990** on the expression list.
1991**
1992** pList might be NULL following an OOM error. But pSpan should never be
1993** NULL. If a memory allocation fails, the pParse->db->mallocFailed flag
1994** is set.
1995*/
1996void sqlite3ExprListSetSpan(
1997 Parse *pParse, /* Parsing context */
1998 ExprList *pList, /* List to which to add the span. */
1999 const char *zStart, /* Start of the span */
2000 const char *zEnd /* End of the span */
2001){
2002 sqlite3 *db = pParse->db;
2003 assert( pList!=0 || db->mallocFailed!=0 );
2004 if( pList ){
2005 struct ExprList_item *pItem = &pList->a[pList->nExpr-1];
2006 assert( pList->nExpr>0 );
2007 if( pItem->zEName==0 ){
2008 pItem->zEName = sqlite3DbSpanDup(db, zStart, zEnd);
2009 pItem->fg.eEName = ENAME_SPAN;
2010 }
2011 }
2012}
2013
2014/*
2015** If the expression list pEList contains more than iLimit elements,
2016** leave an error message in pParse.
2017*/
2018void sqlite3ExprListCheckLength(
2019 Parse *pParse,
2020 ExprList *pEList,
2021 const char *zObject
2022){
2023 int mx = pParse->db->aLimit[SQLITE_LIMIT_COLUMN];
2024 testcase( pEList && pEList->nExpr==mx );
2025 testcase( pEList && pEList->nExpr==mx+1 );
2026 if( pEList && pEList->nExpr>mx ){
2027 sqlite3ErrorMsg(pParse, "too many columns in %s", zObject);
2028 }
2029}
2030
2031/*
2032** Delete an entire expression list.
2033*/
2034static SQLITE_NOINLINE void exprListDeleteNN(sqlite3 *db, ExprList *pList){
2035 int i = pList->nExpr;
2036 struct ExprList_item *pItem = pList->a;
2037 assert( pList->nExpr>0 );
2038 assert( db!=0 );
2039 do{
2040 sqlite3ExprDelete(db, pItem->pExpr);
2041 if( pItem->zEName ) sqlite3DbNNFreeNN(db, pItem->zEName);
2042 pItem++;
2043 }while( --i>0 );
2044 sqlite3DbNNFreeNN(db, pList);
2045}
2046void sqlite3ExprListDelete(sqlite3 *db, ExprList *pList){
2047 if( pList ) exprListDeleteNN(db, pList);
2048}
2049
2050/*
2051** Return the bitwise-OR of all Expr.flags fields in the given
2052** ExprList.
2053*/
2054u32 sqlite3ExprListFlags(const ExprList *pList){
2055 int i;
2056 u32 m = 0;
2057 assert( pList!=0 );
2058 for(i=0; i<pList->nExpr; i++){
2059 Expr *pExpr = pList->a[i].pExpr;
2060 assert( pExpr!=0 );
2061 m |= pExpr->flags;
2062 }
2063 return m;
2064}
2065
2066/*
2067** This is a SELECT-node callback for the expression walker that
2068** always "fails". By "fail" in this case, we mean set
2069** pWalker->eCode to zero and abort.
2070**
2071** This callback is used by multiple expression walkers.
2072*/
2073int sqlite3SelectWalkFail(Walker *pWalker, Select *NotUsed){
2074 UNUSED_PARAMETER(NotUsed);
2075 pWalker->eCode = 0;
2076 return WRC_Abort;
2077}
2078
2079/*
2080** Check the input string to see if it is "true" or "false" (in any case).
2081**
2082** If the string is.... Return
2083** "true" EP_IsTrue
2084** "false" EP_IsFalse
2085** anything else 0
2086*/
2087u32 sqlite3IsTrueOrFalse(const char *zIn){
2088 if( sqlite3StrICmp(zIn, "true")==0 ) return EP_IsTrue;
2089 if( sqlite3StrICmp(zIn, "false")==0 ) return EP_IsFalse;
2090 return 0;
2091}
2092
2093
2094/*
2095** If the input expression is an ID with the name "true" or "false"
2096** then convert it into an TK_TRUEFALSE term. Return non-zero if
2097** the conversion happened, and zero if the expression is unaltered.
2098*/
2099int sqlite3ExprIdToTrueFalse(Expr *pExpr){
2100 u32 v;
2101 assert( pExpr->op==TK_ID || pExpr->op==TK_STRING );
2102 if( !ExprHasProperty(pExpr, EP_Quoted|EP_IntValue)
2103 && (v = sqlite3IsTrueOrFalse(pExpr->u.zToken))!=0
2104 ){
2105 pExpr->op = TK_TRUEFALSE;
2106 ExprSetProperty(pExpr, v);
2107 return 1;
2108 }
2109 return 0;
2110}
2111
2112/*
2113** The argument must be a TK_TRUEFALSE Expr node. Return 1 if it is TRUE
2114** and 0 if it is FALSE.
2115*/
2116int sqlite3ExprTruthValue(const Expr *pExpr){
2117 pExpr = sqlite3ExprSkipCollate((Expr*)pExpr);
2118 assert( pExpr->op==TK_TRUEFALSE );
2119 assert( !ExprHasProperty(pExpr, EP_IntValue) );
2120 assert( sqlite3StrICmp(pExpr->u.zToken,"true")==0
2121 || sqlite3StrICmp(pExpr->u.zToken,"false")==0 );
2122 return pExpr->u.zToken[4]==0;
2123}
2124
2125/*
2126** If pExpr is an AND or OR expression, try to simplify it by eliminating
2127** terms that are always true or false. Return the simplified expression.
2128** Or return the original expression if no simplification is possible.
2129**
2130** Examples:
2131**
2132** (x<10) AND true => (x<10)
2133** (x<10) AND false => false
2134** (x<10) AND (y=22 OR false) => (x<10) AND (y=22)
2135** (x<10) AND (y=22 OR true) => (x<10)
2136** (y=22) OR true => true
2137*/
2138Expr *sqlite3ExprSimplifiedAndOr(Expr *pExpr){
2139 assert( pExpr!=0 );
2140 if( pExpr->op==TK_AND || pExpr->op==TK_OR ){
2141 Expr *pRight = sqlite3ExprSimplifiedAndOr(pExpr->pRight);
2142 Expr *pLeft = sqlite3ExprSimplifiedAndOr(pExpr->pLeft);
2143 if( ExprAlwaysTrue(pLeft) || ExprAlwaysFalse(pRight) ){
2144 pExpr = pExpr->op==TK_AND ? pRight : pLeft;
2145 }else if( ExprAlwaysTrue(pRight) || ExprAlwaysFalse(pLeft) ){
2146 pExpr = pExpr->op==TK_AND ? pLeft : pRight;
2147 }
2148 }
2149 return pExpr;
2150}
2151
2152
2153/*
2154** These routines are Walker callbacks used to check expressions to
2155** see if they are "constant" for some definition of constant. The
2156** Walker.eCode value determines the type of "constant" we are looking
2157** for.
2158**
2159** These callback routines are used to implement the following:
2160**
2161** sqlite3ExprIsConstant() pWalker->eCode==1
2162** sqlite3ExprIsConstantNotJoin() pWalker->eCode==2
2163** sqlite3ExprIsTableConstant() pWalker->eCode==3
2164** sqlite3ExprIsConstantOrFunction() pWalker->eCode==4 or 5
2165**
2166** In all cases, the callbacks set Walker.eCode=0 and abort if the expression
2167** is found to not be a constant.
2168**
2169** The sqlite3ExprIsConstantOrFunction() is used for evaluating DEFAULT
2170** expressions in a CREATE TABLE statement. The Walker.eCode value is 5
2171** when parsing an existing schema out of the sqlite_schema table and 4
2172** when processing a new CREATE TABLE statement. A bound parameter raises
2173** an error for new statements, but is silently converted
2174** to NULL for existing schemas. This allows sqlite_schema tables that
2175** contain a bound parameter because they were generated by older versions
2176** of SQLite to be parsed by newer versions of SQLite without raising a
2177** malformed schema error.
2178*/
2179static int exprNodeIsConstant(Walker *pWalker, Expr *pExpr){
2180
2181 /* If pWalker->eCode is 2 then any term of the expression that comes from
2182 ** the ON or USING clauses of an outer join disqualifies the expression
2183 ** from being considered constant. */
2184 if( pWalker->eCode==2 && ExprHasProperty(pExpr, EP_OuterON) ){
2185 pWalker->eCode = 0;
2186 return WRC_Abort;
2187 }
2188
2189 switch( pExpr->op ){
2190 /* Consider functions to be constant if all their arguments are constant
2191 ** and either pWalker->eCode==4 or 5 or the function has the
2192 ** SQLITE_FUNC_CONST flag. */
2193 case TK_FUNCTION:
2194 if( (pWalker->eCode>=4 || ExprHasProperty(pExpr,EP_ConstFunc))
2195 && !ExprHasProperty(pExpr, EP_WinFunc)
2196 ){
2197 if( pWalker->eCode==5 ) ExprSetProperty(pExpr, EP_FromDDL);
2198 return WRC_Continue;
2199 }else{
2200 pWalker->eCode = 0;
2201 return WRC_Abort;
2202 }
2203 case TK_ID:
2204 /* Convert "true" or "false" in a DEFAULT clause into the
2205 ** appropriate TK_TRUEFALSE operator */
2206 if( sqlite3ExprIdToTrueFalse(pExpr) ){
2207 return WRC_Prune;
2208 }
2209 /* no break */ deliberate_fall_through
2210 case TK_COLUMN:
2211 case TK_AGG_FUNCTION:
2212 case TK_AGG_COLUMN:
2213 testcase( pExpr->op==TK_ID );
2214 testcase( pExpr->op==TK_COLUMN );
2215 testcase( pExpr->op==TK_AGG_FUNCTION );
2216 testcase( pExpr->op==TK_AGG_COLUMN );
2217 if( ExprHasProperty(pExpr, EP_FixedCol) && pWalker->eCode!=2 ){
2218 return WRC_Continue;
2219 }
2220 if( pWalker->eCode==3 && pExpr->iTable==pWalker->u.iCur ){
2221 return WRC_Continue;
2222 }
2223 /* no break */ deliberate_fall_through
2224 case TK_IF_NULL_ROW:
2225 case TK_REGISTER:
2226 case TK_DOT:
2227 testcase( pExpr->op==TK_REGISTER );
2228 testcase( pExpr->op==TK_IF_NULL_ROW );
2229 testcase( pExpr->op==TK_DOT );
2230 pWalker->eCode = 0;
2231 return WRC_Abort;
2232 case TK_VARIABLE:
2233 if( pWalker->eCode==5 ){
2234 /* Silently convert bound parameters that appear inside of CREATE
2235 ** statements into a NULL when parsing the CREATE statement text out
2236 ** of the sqlite_schema table */
2237 pExpr->op = TK_NULL;
2238 }else if( pWalker->eCode==4 ){
2239 /* A bound parameter in a CREATE statement that originates from
2240 ** sqlite3_prepare() causes an error */
2241 pWalker->eCode = 0;
2242 return WRC_Abort;
2243 }
2244 /* no break */ deliberate_fall_through
2245 default:
2246 testcase( pExpr->op==TK_SELECT ); /* sqlite3SelectWalkFail() disallows */
2247 testcase( pExpr->op==TK_EXISTS ); /* sqlite3SelectWalkFail() disallows */
2248 return WRC_Continue;
2249 }
2250}
2251static int exprIsConst(Expr *p, int initFlag, int iCur){
2252 Walker w;
2253 w.eCode = initFlag;
2254 w.xExprCallback = exprNodeIsConstant;
2255 w.xSelectCallback = sqlite3SelectWalkFail;
2256#ifdef SQLITE_DEBUG
2257 w.xSelectCallback2 = sqlite3SelectWalkAssert2;
2258#endif
2259 w.u.iCur = iCur;
2260 sqlite3WalkExpr(&w, p);
2261 return w.eCode;
2262}
2263
2264/*
2265** Walk an expression tree. Return non-zero if the expression is constant
2266** and 0 if it involves variables or function calls.
2267**
2268** For the purposes of this function, a double-quoted string (ex: "abc")
2269** is considered a variable but a single-quoted string (ex: 'abc') is
2270** a constant.
2271*/
2272int sqlite3ExprIsConstant(Expr *p){
2273 return exprIsConst(p, 1, 0);
2274}
2275
2276/*
2277** Walk an expression tree. Return non-zero if
2278**
2279** (1) the expression is constant, and
2280** (2) the expression does originate in the ON or USING clause
2281** of a LEFT JOIN, and
2282** (3) the expression does not contain any EP_FixedCol TK_COLUMN
2283** operands created by the constant propagation optimization.
2284**
2285** When this routine returns true, it indicates that the expression
2286** can be added to the pParse->pConstExpr list and evaluated once when
2287** the prepared statement starts up. See sqlite3ExprCodeRunJustOnce().
2288*/
2289int sqlite3ExprIsConstantNotJoin(Expr *p){
2290 return exprIsConst(p, 2, 0);
2291}
2292
2293/*
2294** Walk an expression tree. Return non-zero if the expression is constant
2295** for any single row of the table with cursor iCur. In other words, the
2296** expression must not refer to any non-deterministic function nor any
2297** table other than iCur.
2298*/
2299int sqlite3ExprIsTableConstant(Expr *p, int iCur){
2300 return exprIsConst(p, 3, iCur);
2301}
2302
2303/*
2304** Check pExpr to see if it is an invariant constraint on data source pSrc.
2305** This is an optimization. False negatives will perhaps cause slower
2306** queries, but false positives will yield incorrect answers. So when in
2307** doubt, return 0.
2308**
2309** To be an invariant constraint, the following must be true:
2310**
2311** (1) pExpr cannot refer to any table other than pSrc->iCursor.
2312**
2313** (2) pExpr cannot use subqueries or non-deterministic functions.
2314**
2315** (3) pSrc cannot be part of the left operand for a RIGHT JOIN.
2316** (Is there some way to relax this constraint?)
2317**
2318** (4) If pSrc is the right operand of a LEFT JOIN, then...
2319** (4a) pExpr must come from an ON clause..
2320 (4b) and specifically the ON clause associated with the LEFT JOIN.
2321**
2322** (5) If pSrc is not the right operand of a LEFT JOIN or the left
2323** operand of a RIGHT JOIN, then pExpr must be from the WHERE
2324** clause, not an ON clause.
2325*/
2326int sqlite3ExprIsTableConstraint(Expr *pExpr, const SrcItem *pSrc){
2327 if( pSrc->fg.jointype & JT_LTORJ ){
2328 return 0; /* rule (3) */
2329 }
2330 if( pSrc->fg.jointype & JT_LEFT ){
2331 if( !ExprHasProperty(pExpr, EP_OuterON) ) return 0; /* rule (4a) */
2332 if( pExpr->w.iJoin!=pSrc->iCursor ) return 0; /* rule (4b) */
2333 }else{
2334 if( ExprHasProperty(pExpr, EP_OuterON) ) return 0; /* rule (5) */
2335 }
2336 return sqlite3ExprIsTableConstant(pExpr, pSrc->iCursor); /* rules (1), (2) */
2337}
2338
2339
2340/*
2341** sqlite3WalkExpr() callback used by sqlite3ExprIsConstantOrGroupBy().
2342*/
2343static int exprNodeIsConstantOrGroupBy(Walker *pWalker, Expr *pExpr){
2344 ExprList *pGroupBy = pWalker->u.pGroupBy;
2345 int i;
2346
2347 /* Check if pExpr is identical to any GROUP BY term. If so, consider
2348 ** it constant. */
2349 for(i=0; i<pGroupBy->nExpr; i++){
2350 Expr *p = pGroupBy->a[i].pExpr;
2351 if( sqlite3ExprCompare(0, pExpr, p, -1)<2 ){
2352 CollSeq *pColl = sqlite3ExprNNCollSeq(pWalker->pParse, p);
2353 if( sqlite3IsBinary(pColl) ){
2354 return WRC_Prune;
2355 }
2356 }
2357 }
2358
2359 /* Check if pExpr is a sub-select. If so, consider it variable. */
2360 if( ExprUseXSelect(pExpr) ){
2361 pWalker->eCode = 0;
2362 return WRC_Abort;
2363 }
2364
2365 return exprNodeIsConstant(pWalker, pExpr);
2366}
2367
2368/*
2369** Walk the expression tree passed as the first argument. Return non-zero
2370** if the expression consists entirely of constants or copies of terms
2371** in pGroupBy that sort with the BINARY collation sequence.
2372**
2373** This routine is used to determine if a term of the HAVING clause can
2374** be promoted into the WHERE clause. In order for such a promotion to work,
2375** the value of the HAVING clause term must be the same for all members of
2376** a "group". The requirement that the GROUP BY term must be BINARY
2377** assumes that no other collating sequence will have a finer-grained
2378** grouping than binary. In other words (A=B COLLATE binary) implies
2379** A=B in every other collating sequence. The requirement that the
2380** GROUP BY be BINARY is stricter than necessary. It would also work
2381** to promote HAVING clauses that use the same alternative collating
2382** sequence as the GROUP BY term, but that is much harder to check,
2383** alternative collating sequences are uncommon, and this is only an
2384** optimization, so we take the easy way out and simply require the
2385** GROUP BY to use the BINARY collating sequence.
2386*/
2387int sqlite3ExprIsConstantOrGroupBy(Parse *pParse, Expr *p, ExprList *pGroupBy){
2388 Walker w;
2389 w.eCode = 1;
2390 w.xExprCallback = exprNodeIsConstantOrGroupBy;
2391 w.xSelectCallback = 0;
2392 w.u.pGroupBy = pGroupBy;
2393 w.pParse = pParse;
2394 sqlite3WalkExpr(&w, p);
2395 return w.eCode;
2396}
2397
2398/*
2399** Walk an expression tree for the DEFAULT field of a column definition
2400** in a CREATE TABLE statement. Return non-zero if the expression is
2401** acceptable for use as a DEFAULT. That is to say, return non-zero if
2402** the expression is constant or a function call with constant arguments.
2403** Return and 0 if there are any variables.
2404**
2405** isInit is true when parsing from sqlite_schema. isInit is false when
2406** processing a new CREATE TABLE statement. When isInit is true, parameters
2407** (such as ? or $abc) in the expression are converted into NULL. When
2408** isInit is false, parameters raise an error. Parameters should not be
2409** allowed in a CREATE TABLE statement, but some legacy versions of SQLite
2410** allowed it, so we need to support it when reading sqlite_schema for
2411** backwards compatibility.
2412**
2413** If isInit is true, set EP_FromDDL on every TK_FUNCTION node.
2414**
2415** For the purposes of this function, a double-quoted string (ex: "abc")
2416** is considered a variable but a single-quoted string (ex: 'abc') is
2417** a constant.
2418*/
2419int sqlite3ExprIsConstantOrFunction(Expr *p, u8 isInit){
2420 assert( isInit==0 || isInit==1 );
2421 return exprIsConst(p, 4+isInit, 0);
2422}
2423
2424#ifdef SQLITE_ENABLE_CURSOR_HINTS
2425/*
2426** Walk an expression tree. Return 1 if the expression contains a
2427** subquery of some kind. Return 0 if there are no subqueries.
2428*/
2429int sqlite3ExprContainsSubquery(Expr *p){
2430 Walker w;
2431 w.eCode = 1;
2432 w.xExprCallback = sqlite3ExprWalkNoop;
2433 w.xSelectCallback = sqlite3SelectWalkFail;
2434#ifdef SQLITE_DEBUG
2435 w.xSelectCallback2 = sqlite3SelectWalkAssert2;
2436#endif
2437 sqlite3WalkExpr(&w, p);
2438 return w.eCode==0;
2439}
2440#endif
2441
2442/*
2443** If the expression p codes a constant integer that is small enough
2444** to fit in a 32-bit integer, return 1 and put the value of the integer
2445** in *pValue. If the expression is not an integer or if it is too big
2446** to fit in a signed 32-bit integer, return 0 and leave *pValue unchanged.
2447*/
2448int sqlite3ExprIsInteger(const Expr *p, int *pValue){
2449 int rc = 0;
2450 if( NEVER(p==0) ) return 0; /* Used to only happen following on OOM */
2451
2452 /* If an expression is an integer literal that fits in a signed 32-bit
2453 ** integer, then the EP_IntValue flag will have already been set */
2454 assert( p->op!=TK_INTEGER || (p->flags & EP_IntValue)!=0
2455 || sqlite3GetInt32(p->u.zToken, &rc)==0 );
2456
2457 if( p->flags & EP_IntValue ){
2458 *pValue = p->u.iValue;
2459 return 1;
2460 }
2461 switch( p->op ){
2462 case TK_UPLUS: {
2463 rc = sqlite3ExprIsInteger(p->pLeft, pValue);
2464 break;
2465 }
2466 case TK_UMINUS: {
2467 int v = 0;
2468 if( sqlite3ExprIsInteger(p->pLeft, &v) ){
2469 assert( ((unsigned int)v)!=0x80000000 );
2470 *pValue = -v;
2471 rc = 1;
2472 }
2473 break;
2474 }
2475 default: break;
2476 }
2477 return rc;
2478}
2479
2480/*
2481** Return FALSE if there is no chance that the expression can be NULL.
2482**
2483** If the expression might be NULL or if the expression is too complex
2484** to tell return TRUE.
2485**
2486** This routine is used as an optimization, to skip OP_IsNull opcodes
2487** when we know that a value cannot be NULL. Hence, a false positive
2488** (returning TRUE when in fact the expression can never be NULL) might
2489** be a small performance hit but is otherwise harmless. On the other
2490** hand, a false negative (returning FALSE when the result could be NULL)
2491** will likely result in an incorrect answer. So when in doubt, return
2492** TRUE.
2493*/
2494int sqlite3ExprCanBeNull(const Expr *p){
2495 u8 op;
2496 assert( p!=0 );
2497 while( p->op==TK_UPLUS || p->op==TK_UMINUS ){
2498 p = p->pLeft;
2499 assert( p!=0 );
2500 }
2501 op = p->op;
2502 if( op==TK_REGISTER ) op = p->op2;
2503 switch( op ){
2504 case TK_INTEGER:
2505 case TK_STRING:
2506 case TK_FLOAT:
2507 case TK_BLOB:
2508 return 0;
2509 case TK_COLUMN:
2510 assert( ExprUseYTab(p) );
2511 return ExprHasProperty(p, EP_CanBeNull) ||
2512 p->y.pTab==0 || /* Reference to column of index on expression */
2513 (p->iColumn>=0
2514 && p->y.pTab->aCol!=0 /* Possible due to prior error */
2515 && p->y.pTab->aCol[p->iColumn].notNull==0);
2516 default:
2517 return 1;
2518 }
2519}
2520
2521/*
2522** Return TRUE if the given expression is a constant which would be
2523** unchanged by OP_Affinity with the affinity given in the second
2524** argument.
2525**
2526** This routine is used to determine if the OP_Affinity operation
2527** can be omitted. When in doubt return FALSE. A false negative
2528** is harmless. A false positive, however, can result in the wrong
2529** answer.
2530*/
2531int sqlite3ExprNeedsNoAffinityChange(const Expr *p, char aff){
2532 u8 op;
2533 int unaryMinus = 0;
2534 if( aff==SQLITE_AFF_BLOB ) return 1;
2535 while( p->op==TK_UPLUS || p->op==TK_UMINUS ){
2536 if( p->op==TK_UMINUS ) unaryMinus = 1;
2537 p = p->pLeft;
2538 }
2539 op = p->op;
2540 if( op==TK_REGISTER ) op = p->op2;
2541 switch( op ){
2542 case TK_INTEGER: {
2543 return aff>=SQLITE_AFF_NUMERIC;
2544 }
2545 case TK_FLOAT: {
2546 return aff>=SQLITE_AFF_NUMERIC;
2547 }
2548 case TK_STRING: {
2549 return !unaryMinus && aff==SQLITE_AFF_TEXT;
2550 }
2551 case TK_BLOB: {
2552 return !unaryMinus;
2553 }
2554 case TK_COLUMN: {
2555 assert( p->iTable>=0 ); /* p cannot be part of a CHECK constraint */
2556 return aff>=SQLITE_AFF_NUMERIC && p->iColumn<0;
2557 }
2558 default: {
2559 return 0;
2560 }
2561 }
2562}
2563
2564/*
2565** Return TRUE if the given string is a row-id column name.
2566*/
2567int sqlite3IsRowid(const char *z){
2568 if( sqlite3StrICmp(z, "_ROWID_")==0 ) return 1;
2569 if( sqlite3StrICmp(z, "ROWID")==0 ) return 1;
2570 if( sqlite3StrICmp(z, "OID")==0 ) return 1;
2571 return 0;
2572}
2573
2574/*
2575** pX is the RHS of an IN operator. If pX is a SELECT statement
2576** that can be simplified to a direct table access, then return
2577** a pointer to the SELECT statement. If pX is not a SELECT statement,
2578** or if the SELECT statement needs to be manifested into a transient
2579** table, then return NULL.
2580*/
2581#ifndef SQLITE_OMIT_SUBQUERY
2582static Select *isCandidateForInOpt(const Expr *pX){
2583 Select *p;
2584 SrcList *pSrc;
2585 ExprList *pEList;
2586 Table *pTab;
2587 int i;
2588 if( !ExprUseXSelect(pX) ) return 0; /* Not a subquery */
2589 if( ExprHasProperty(pX, EP_VarSelect) ) return 0; /* Correlated subq */
2590 p = pX->x.pSelect;
2591 if( p->pPrior ) return 0; /* Not a compound SELECT */
2592 if( p->selFlags & (SF_Distinct|SF_Aggregate) ){
2593 testcase( (p->selFlags & (SF_Distinct|SF_Aggregate))==SF_Distinct );
2594 testcase( (p->selFlags & (SF_Distinct|SF_Aggregate))==SF_Aggregate );
2595 return 0; /* No DISTINCT keyword and no aggregate functions */
2596 }
2597 assert( p->pGroupBy==0 ); /* Has no GROUP BY clause */
2598 if( p->pLimit ) return 0; /* Has no LIMIT clause */
2599 if( p->pWhere ) return 0; /* Has no WHERE clause */
2600 pSrc = p->pSrc;
2601 assert( pSrc!=0 );
2602 if( pSrc->nSrc!=1 ) return 0; /* Single term in FROM clause */
2603 if( pSrc->a[0].pSelect ) return 0; /* FROM is not a subquery or view */
2604 pTab = pSrc->a[0].pTab;
2605 assert( pTab!=0 );
2606 assert( !IsView(pTab) ); /* FROM clause is not a view */
2607 if( IsVirtual(pTab) ) return 0; /* FROM clause not a virtual table */
2608 pEList = p->pEList;
2609 assert( pEList!=0 );
2610 /* All SELECT results must be columns. */
2611 for(i=0; i<pEList->nExpr; i++){
2612 Expr *pRes = pEList->a[i].pExpr;
2613 if( pRes->op!=TK_COLUMN ) return 0;
2614 assert( pRes->iTable==pSrc->a[0].iCursor ); /* Not a correlated subquery */
2615 }
2616 return p;
2617}
2618#endif /* SQLITE_OMIT_SUBQUERY */
2619
2620#ifndef SQLITE_OMIT_SUBQUERY
2621/*
2622** Generate code that checks the left-most column of index table iCur to see if
2623** it contains any NULL entries. Cause the register at regHasNull to be set
2624** to a non-NULL value if iCur contains no NULLs. Cause register regHasNull
2625** to be set to NULL if iCur contains one or more NULL values.
2626*/
2627static void sqlite3SetHasNullFlag(Vdbe *v, int iCur, int regHasNull){
2628 int addr1;
2629 sqlite3VdbeAddOp2(v, OP_Integer, 0, regHasNull);
2630 addr1 = sqlite3VdbeAddOp1(v, OP_Rewind, iCur); VdbeCoverage(v);
2631 sqlite3VdbeAddOp3(v, OP_Column, iCur, 0, regHasNull);
2632 sqlite3VdbeChangeP5(v, OPFLAG_TYPEOFARG);
2633 VdbeComment((v, "first_entry_in(%d)", iCur));
2634 sqlite3VdbeJumpHere(v, addr1);
2635}
2636#endif
2637
2638
2639#ifndef SQLITE_OMIT_SUBQUERY
2640/*
2641** The argument is an IN operator with a list (not a subquery) on the
2642** right-hand side. Return TRUE if that list is constant.
2643*/
2644static int sqlite3InRhsIsConstant(Expr *pIn){
2645 Expr *pLHS;
2646 int res;
2647 assert( !ExprHasProperty(pIn, EP_xIsSelect) );
2648 pLHS = pIn->pLeft;
2649 pIn->pLeft = 0;
2650 res = sqlite3ExprIsConstant(pIn);
2651 pIn->pLeft = pLHS;
2652 return res;
2653}
2654#endif
2655
2656/*
2657** This function is used by the implementation of the IN (...) operator.
2658** The pX parameter is the expression on the RHS of the IN operator, which
2659** might be either a list of expressions or a subquery.
2660**
2661** The job of this routine is to find or create a b-tree object that can
2662** be used either to test for membership in the RHS set or to iterate through
2663** all members of the RHS set, skipping duplicates.
2664**
2665** A cursor is opened on the b-tree object that is the RHS of the IN operator
2666** and the *piTab parameter is set to the index of that cursor.
2667**
2668** The returned value of this function indicates the b-tree type, as follows:
2669**
2670** IN_INDEX_ROWID - The cursor was opened on a database table.
2671** IN_INDEX_INDEX_ASC - The cursor was opened on an ascending index.
2672** IN_INDEX_INDEX_DESC - The cursor was opened on a descending index.
2673** IN_INDEX_EPH - The cursor was opened on a specially created and
2674** populated epheremal table.
2675** IN_INDEX_NOOP - No cursor was allocated. The IN operator must be
2676** implemented as a sequence of comparisons.
2677**
2678** An existing b-tree might be used if the RHS expression pX is a simple
2679** subquery such as:
2680**
2681** SELECT <column1>, <column2>... FROM <table>
2682**
2683** If the RHS of the IN operator is a list or a more complex subquery, then
2684** an ephemeral table might need to be generated from the RHS and then
2685** pX->iTable made to point to the ephemeral table instead of an
2686** existing table. In this case, the creation and initialization of the
2687** ephmeral table might be put inside of a subroutine, the EP_Subrtn flag
2688** will be set on pX and the pX->y.sub fields will be set to show where
2689** the subroutine is coded.
2690**
2691** The inFlags parameter must contain, at a minimum, one of the bits
2692** IN_INDEX_MEMBERSHIP or IN_INDEX_LOOP but not both. If inFlags contains
2693** IN_INDEX_MEMBERSHIP, then the generated table will be used for a fast
2694** membership test. When the IN_INDEX_LOOP bit is set, the IN index will
2695** be used to loop over all values of the RHS of the IN operator.
2696**
2697** When IN_INDEX_LOOP is used (and the b-tree will be used to iterate
2698** through the set members) then the b-tree must not contain duplicates.
2699** An epheremal table will be created unless the selected columns are guaranteed
2700** to be unique - either because it is an INTEGER PRIMARY KEY or due to
2701** a UNIQUE constraint or index.
2702**
2703** When IN_INDEX_MEMBERSHIP is used (and the b-tree will be used
2704** for fast set membership tests) then an epheremal table must
2705** be used unless <columns> is a single INTEGER PRIMARY KEY column or an
2706** index can be found with the specified <columns> as its left-most.
2707**
2708** If the IN_INDEX_NOOP_OK and IN_INDEX_MEMBERSHIP are both set and
2709** if the RHS of the IN operator is a list (not a subquery) then this
2710** routine might decide that creating an ephemeral b-tree for membership
2711** testing is too expensive and return IN_INDEX_NOOP. In that case, the
2712** calling routine should implement the IN operator using a sequence
2713** of Eq or Ne comparison operations.
2714**
2715** When the b-tree is being used for membership tests, the calling function
2716** might need to know whether or not the RHS side of the IN operator
2717** contains a NULL. If prRhsHasNull is not a NULL pointer and
2718** if there is any chance that the (...) might contain a NULL value at
2719** runtime, then a register is allocated and the register number written
2720** to *prRhsHasNull. If there is no chance that the (...) contains a
2721** NULL value, then *prRhsHasNull is left unchanged.
2722**
2723** If a register is allocated and its location stored in *prRhsHasNull, then
2724** the value in that register will be NULL if the b-tree contains one or more
2725** NULL values, and it will be some non-NULL value if the b-tree contains no
2726** NULL values.
2727**
2728** If the aiMap parameter is not NULL, it must point to an array containing
2729** one element for each column returned by the SELECT statement on the RHS
2730** of the IN(...) operator. The i'th entry of the array is populated with the
2731** offset of the index column that matches the i'th column returned by the
2732** SELECT. For example, if the expression and selected index are:
2733**
2734** (?,?,?) IN (SELECT a, b, c FROM t1)
2735** CREATE INDEX i1 ON t1(b, c, a);
2736**
2737** then aiMap[] is populated with {2, 0, 1}.
2738*/
2739#ifndef SQLITE_OMIT_SUBQUERY
2740int sqlite3FindInIndex(
2741 Parse *pParse, /* Parsing context */
2742 Expr *pX, /* The IN expression */
2743 u32 inFlags, /* IN_INDEX_LOOP, _MEMBERSHIP, and/or _NOOP_OK */
2744 int *prRhsHasNull, /* Register holding NULL status. See notes */
2745 int *aiMap, /* Mapping from Index fields to RHS fields */
2746 int *piTab /* OUT: index to use */
2747){
2748 Select *p; /* SELECT to the right of IN operator */
2749 int eType = 0; /* Type of RHS table. IN_INDEX_* */
2750 int iTab; /* Cursor of the RHS table */
2751 int mustBeUnique; /* True if RHS must be unique */
2752 Vdbe *v = sqlite3GetVdbe(pParse); /* Virtual machine being coded */
2753
2754 assert( pX->op==TK_IN );
2755 mustBeUnique = (inFlags & IN_INDEX_LOOP)!=0;
2756 iTab = pParse->nTab++;
2757
2758 /* If the RHS of this IN(...) operator is a SELECT, and if it matters
2759 ** whether or not the SELECT result contains NULL values, check whether
2760 ** or not NULL is actually possible (it may not be, for example, due
2761 ** to NOT NULL constraints in the schema). If no NULL values are possible,
2762 ** set prRhsHasNull to 0 before continuing. */
2763 if( prRhsHasNull && ExprUseXSelect(pX) ){
2764 int i;
2765 ExprList *pEList = pX->x.pSelect->pEList;
2766 for(i=0; i<pEList->nExpr; i++){
2767 if( sqlite3ExprCanBeNull(pEList->a[i].pExpr) ) break;
2768 }
2769 if( i==pEList->nExpr ){
2770 prRhsHasNull = 0;
2771 }
2772 }
2773
2774 /* Check to see if an existing table or index can be used to
2775 ** satisfy the query. This is preferable to generating a new
2776 ** ephemeral table. */
2777 if( pParse->nErr==0 && (p = isCandidateForInOpt(pX))!=0 ){
2778 sqlite3 *db = pParse->db; /* Database connection */
2779 Table *pTab; /* Table <table>. */
2780 int iDb; /* Database idx for pTab */
2781 ExprList *pEList = p->pEList;
2782 int nExpr = pEList->nExpr;
2783
2784 assert( p->pEList!=0 ); /* Because of isCandidateForInOpt(p) */
2785 assert( p->pEList->a[0].pExpr!=0 ); /* Because of isCandidateForInOpt(p) */
2786 assert( p->pSrc!=0 ); /* Because of isCandidateForInOpt(p) */
2787 pTab = p->pSrc->a[0].pTab;
2788
2789 /* Code an OP_Transaction and OP_TableLock for <table>. */
2790 iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
2791 assert( iDb>=0 && iDb<SQLITE_MAX_DB );
2792 sqlite3CodeVerifySchema(pParse, iDb);
2793 sqlite3TableLock(pParse, iDb, pTab->tnum, 0, pTab->zName);
2794
2795 assert(v); /* sqlite3GetVdbe() has always been previously called */
2796 if( nExpr==1 && pEList->a[0].pExpr->iColumn<0 ){
2797 /* The "x IN (SELECT rowid FROM table)" case */
2798 int iAddr = sqlite3VdbeAddOp0(v, OP_Once);
2799 VdbeCoverage(v);
2800
2801 sqlite3OpenTable(pParse, iTab, iDb, pTab, OP_OpenRead);
2802 eType = IN_INDEX_ROWID;
2803 ExplainQueryPlan((pParse, 0,
2804 "USING ROWID SEARCH ON TABLE %s FOR IN-OPERATOR",pTab->zName));
2805 sqlite3VdbeJumpHere(v, iAddr);
2806 }else{
2807 Index *pIdx; /* Iterator variable */
2808 int affinity_ok = 1;
2809 int i;
2810
2811 /* Check that the affinity that will be used to perform each
2812 ** comparison is the same as the affinity of each column in table
2813 ** on the RHS of the IN operator. If it not, it is not possible to
2814 ** use any index of the RHS table. */
2815 for(i=0; i<nExpr && affinity_ok; i++){
2816 Expr *pLhs = sqlite3VectorFieldSubexpr(pX->pLeft, i);
2817 int iCol = pEList->a[i].pExpr->iColumn;
2818 char idxaff = sqlite3TableColumnAffinity(pTab,iCol); /* RHS table */
2819 char cmpaff = sqlite3CompareAffinity(pLhs, idxaff);
2820 testcase( cmpaff==SQLITE_AFF_BLOB );
2821 testcase( cmpaff==SQLITE_AFF_TEXT );
2822 switch( cmpaff ){
2823 case SQLITE_AFF_BLOB:
2824 break;
2825 case SQLITE_AFF_TEXT:
2826 /* sqlite3CompareAffinity() only returns TEXT if one side or the
2827 ** other has no affinity and the other side is TEXT. Hence,
2828 ** the only way for cmpaff to be TEXT is for idxaff to be TEXT
2829 ** and for the term on the LHS of the IN to have no affinity. */
2830 assert( idxaff==SQLITE_AFF_TEXT );
2831 break;
2832 default:
2833 affinity_ok = sqlite3IsNumericAffinity(idxaff);
2834 }
2835 }
2836
2837 if( affinity_ok ){
2838 /* Search for an existing index that will work for this IN operator */
2839 for(pIdx=pTab->pIndex; pIdx && eType==0; pIdx=pIdx->pNext){
2840 Bitmask colUsed; /* Columns of the index used */
2841 Bitmask mCol; /* Mask for the current column */
2842 if( pIdx->nColumn<nExpr ) continue;
2843 if( pIdx->pPartIdxWhere!=0 ) continue;
2844 /* Maximum nColumn is BMS-2, not BMS-1, so that we can compute
2845 ** BITMASK(nExpr) without overflowing */
2846 testcase( pIdx->nColumn==BMS-2 );
2847 testcase( pIdx->nColumn==BMS-1 );
2848 if( pIdx->nColumn>=BMS-1 ) continue;
2849 if( mustBeUnique ){
2850 if( pIdx->nKeyCol>nExpr
2851 ||(pIdx->nColumn>nExpr && !IsUniqueIndex(pIdx))
2852 ){
2853 continue; /* This index is not unique over the IN RHS columns */
2854 }
2855 }
2856
2857 colUsed = 0; /* Columns of index used so far */
2858 for(i=0; i<nExpr; i++){
2859 Expr *pLhs = sqlite3VectorFieldSubexpr(pX->pLeft, i);
2860 Expr *pRhs = pEList->a[i].pExpr;
2861 CollSeq *pReq = sqlite3BinaryCompareCollSeq(pParse, pLhs, pRhs);
2862 int j;
2863
2864 assert( pReq!=0 || pRhs->iColumn==XN_ROWID || pParse->nErr );
2865 for(j=0; j<nExpr; j++){
2866 if( pIdx->aiColumn[j]!=pRhs->iColumn ) continue;
2867 assert( pIdx->azColl[j] );
2868 if( pReq!=0 && sqlite3StrICmp(pReq->zName, pIdx->azColl[j])!=0 ){
2869 continue;
2870 }
2871 break;
2872 }
2873 if( j==nExpr ) break;
2874 mCol = MASKBIT(j);
2875 if( mCol & colUsed ) break; /* Each column used only once */
2876 colUsed |= mCol;
2877 if( aiMap ) aiMap[i] = j;
2878 }
2879
2880 assert( i==nExpr || colUsed!=(MASKBIT(nExpr)-1) );
2881 if( colUsed==(MASKBIT(nExpr)-1) ){
2882 /* If we reach this point, that means the index pIdx is usable */
2883 int iAddr = sqlite3VdbeAddOp0(v, OP_Once); VdbeCoverage(v);
2884 ExplainQueryPlan((pParse, 0,
2885 "USING INDEX %s FOR IN-OPERATOR",pIdx->zName));
2886 sqlite3VdbeAddOp3(v, OP_OpenRead, iTab, pIdx->tnum, iDb);
2887 sqlite3VdbeSetP4KeyInfo(pParse, pIdx);
2888 VdbeComment((v, "%s", pIdx->zName));
2889 assert( IN_INDEX_INDEX_DESC == IN_INDEX_INDEX_ASC+1 );
2890 eType = IN_INDEX_INDEX_ASC + pIdx->aSortOrder[0];
2891
2892 if( prRhsHasNull ){
2893#ifdef SQLITE_ENABLE_COLUMN_USED_MASK
2894 i64 mask = (1<<nExpr)-1;
2895 sqlite3VdbeAddOp4Dup8(v, OP_ColumnsUsed,
2896 iTab, 0, 0, (u8*)&mask, P4_INT64);
2897#endif
2898 *prRhsHasNull = ++pParse->nMem;
2899 if( nExpr==1 ){
2900 sqlite3SetHasNullFlag(v, iTab, *prRhsHasNull);
2901 }
2902 }
2903 sqlite3VdbeJumpHere(v, iAddr);
2904 }
2905 } /* End loop over indexes */
2906 } /* End if( affinity_ok ) */
2907 } /* End if not an rowid index */
2908 } /* End attempt to optimize using an index */
2909
2910 /* If no preexisting index is available for the IN clause
2911 ** and IN_INDEX_NOOP is an allowed reply
2912 ** and the RHS of the IN operator is a list, not a subquery
2913 ** and the RHS is not constant or has two or fewer terms,
2914 ** then it is not worth creating an ephemeral table to evaluate
2915 ** the IN operator so return IN_INDEX_NOOP.
2916 */
2917 if( eType==0
2918 && (inFlags & IN_INDEX_NOOP_OK)
2919 && ExprUseXList(pX)
2920 && (!sqlite3InRhsIsConstant(pX) || pX->x.pList->nExpr<=2)
2921 ){
2922 pParse->nTab--; /* Back out the allocation of the unused cursor */
2923 iTab = -1; /* Cursor is not allocated */
2924 eType = IN_INDEX_NOOP;
2925 }
2926
2927 if( eType==0 ){
2928 /* Could not find an existing table or index to use as the RHS b-tree.
2929 ** We will have to generate an ephemeral table to do the job.
2930 */
2931 u32 savedNQueryLoop = pParse->nQueryLoop;
2932 int rMayHaveNull = 0;
2933 eType = IN_INDEX_EPH;
2934 if( inFlags & IN_INDEX_LOOP ){
2935 pParse->nQueryLoop = 0;
2936 }else if( prRhsHasNull ){
2937 *prRhsHasNull = rMayHaveNull = ++pParse->nMem;
2938 }
2939 assert( pX->op==TK_IN );
2940 sqlite3CodeRhsOfIN(pParse, pX, iTab);
2941 if( rMayHaveNull ){
2942 sqlite3SetHasNullFlag(v, iTab, rMayHaveNull);
2943 }
2944 pParse->nQueryLoop = savedNQueryLoop;
2945 }
2946
2947 if( aiMap && eType!=IN_INDEX_INDEX_ASC && eType!=IN_INDEX_INDEX_DESC ){
2948 int i, n;
2949 n = sqlite3ExprVectorSize(pX->pLeft);
2950 for(i=0; i<n; i++) aiMap[i] = i;
2951 }
2952 *piTab = iTab;
2953 return eType;
2954}
2955#endif
2956
2957#ifndef SQLITE_OMIT_SUBQUERY
2958/*
2959** Argument pExpr is an (?, ?...) IN(...) expression. This
2960** function allocates and returns a nul-terminated string containing
2961** the affinities to be used for each column of the comparison.
2962**
2963** It is the responsibility of the caller to ensure that the returned
2964** string is eventually freed using sqlite3DbFree().
2965*/
2966static char *exprINAffinity(Parse *pParse, const Expr *pExpr){
2967 Expr *pLeft = pExpr->pLeft;
2968 int nVal = sqlite3ExprVectorSize(pLeft);
2969 Select *pSelect = ExprUseXSelect(pExpr) ? pExpr->x.pSelect : 0;
2970 char *zRet;
2971
2972 assert( pExpr->op==TK_IN );
2973 zRet = sqlite3DbMallocRaw(pParse->db, nVal+1);
2974 if( zRet ){
2975 int i;
2976 for(i=0; i<nVal; i++){
2977 Expr *pA = sqlite3VectorFieldSubexpr(pLeft, i);
2978 char a = sqlite3ExprAffinity(pA);
2979 if( pSelect ){
2980 zRet[i] = sqlite3CompareAffinity(pSelect->pEList->a[i].pExpr, a);
2981 }else{
2982 zRet[i] = a;
2983 }
2984 }
2985 zRet[nVal] = '\0';
2986 }
2987 return zRet;
2988}
2989#endif
2990
2991#ifndef SQLITE_OMIT_SUBQUERY
2992/*
2993** Load the Parse object passed as the first argument with an error
2994** message of the form:
2995**
2996** "sub-select returns N columns - expected M"
2997*/
2998void sqlite3SubselectError(Parse *pParse, int nActual, int nExpect){
2999 if( pParse->nErr==0 ){
3000 const char *zFmt = "sub-select returns %d columns - expected %d";
3001 sqlite3ErrorMsg(pParse, zFmt, nActual, nExpect);
3002 }
3003}
3004#endif
3005
3006/*
3007** Expression pExpr is a vector that has been used in a context where
3008** it is not permitted. If pExpr is a sub-select vector, this routine
3009** loads the Parse object with a message of the form:
3010**
3011** "sub-select returns N columns - expected 1"
3012**
3013** Or, if it is a regular scalar vector:
3014**
3015** "row value misused"
3016*/
3017void sqlite3VectorErrorMsg(Parse *pParse, Expr *pExpr){
3018#ifndef SQLITE_OMIT_SUBQUERY
3019 if( ExprUseXSelect(pExpr) ){
3020 sqlite3SubselectError(pParse, pExpr->x.pSelect->pEList->nExpr, 1);
3021 }else
3022#endif
3023 {
3024 sqlite3ErrorMsg(pParse, "row value misused");
3025 }
3026}
3027
3028#ifndef SQLITE_OMIT_SUBQUERY
3029/*
3030** Generate code that will construct an ephemeral table containing all terms
3031** in the RHS of an IN operator. The IN operator can be in either of two
3032** forms:
3033**
3034** x IN (4,5,11) -- IN operator with list on right-hand side
3035** x IN (SELECT a FROM b) -- IN operator with subquery on the right
3036**
3037** The pExpr parameter is the IN operator. The cursor number for the
3038** constructed ephermeral table is returned. The first time the ephemeral
3039** table is computed, the cursor number is also stored in pExpr->iTable,
3040** however the cursor number returned might not be the same, as it might
3041** have been duplicated using OP_OpenDup.
3042**
3043** If the LHS expression ("x" in the examples) is a column value, or
3044** the SELECT statement returns a column value, then the affinity of that
3045** column is used to build the index keys. If both 'x' and the
3046** SELECT... statement are columns, then numeric affinity is used
3047** if either column has NUMERIC or INTEGER affinity. If neither
3048** 'x' nor the SELECT... statement are columns, then numeric affinity
3049** is used.
3050*/
3051void sqlite3CodeRhsOfIN(
3052 Parse *pParse, /* Parsing context */
3053 Expr *pExpr, /* The IN operator */
3054 int iTab /* Use this cursor number */
3055){
3056 int addrOnce = 0; /* Address of the OP_Once instruction at top */
3057 int addr; /* Address of OP_OpenEphemeral instruction */
3058 Expr *pLeft; /* the LHS of the IN operator */
3059 KeyInfo *pKeyInfo = 0; /* Key information */
3060 int nVal; /* Size of vector pLeft */
3061 Vdbe *v; /* The prepared statement under construction */
3062
3063 v = pParse->pVdbe;
3064 assert( v!=0 );
3065
3066 /* The evaluation of the IN must be repeated every time it
3067 ** is encountered if any of the following is true:
3068 **
3069 ** * The right-hand side is a correlated subquery
3070 ** * The right-hand side is an expression list containing variables
3071 ** * We are inside a trigger
3072 **
3073 ** If all of the above are false, then we can compute the RHS just once
3074 ** and reuse it many names.
3075 */
3076 if( !ExprHasProperty(pExpr, EP_VarSelect) && pParse->iSelfTab==0 ){
3077 /* Reuse of the RHS is allowed */
3078 /* If this routine has already been coded, but the previous code
3079 ** might not have been invoked yet, so invoke it now as a subroutine.
3080 */
3081 if( ExprHasProperty(pExpr, EP_Subrtn) ){
3082 addrOnce = sqlite3VdbeAddOp0(v, OP_Once); VdbeCoverage(v);
3083 if( ExprUseXSelect(pExpr) ){
3084 ExplainQueryPlan((pParse, 0, "REUSE LIST SUBQUERY %d",
3085 pExpr->x.pSelect->selId));
3086 }
3087 assert( ExprUseYSub(pExpr) );
3088 sqlite3VdbeAddOp2(v, OP_Gosub, pExpr->y.sub.regReturn,
3089 pExpr->y.sub.iAddr);
3090 assert( iTab!=pExpr->iTable );
3091 sqlite3VdbeAddOp2(v, OP_OpenDup, iTab, pExpr->iTable);
3092 sqlite3VdbeJumpHere(v, addrOnce);
3093 return;
3094 }
3095
3096 /* Begin coding the subroutine */
3097 assert( !ExprUseYWin(pExpr) );
3098 ExprSetProperty(pExpr, EP_Subrtn);
3099 assert( !ExprHasProperty(pExpr, EP_TokenOnly|EP_Reduced) );
3100 pExpr->y.sub.regReturn = ++pParse->nMem;
3101 pExpr->y.sub.iAddr =
3102 sqlite3VdbeAddOp2(v, OP_BeginSubrtn, 0, pExpr->y.sub.regReturn) + 1;
3103
3104 addrOnce = sqlite3VdbeAddOp0(v, OP_Once); VdbeCoverage(v);
3105 }
3106
3107 /* Check to see if this is a vector IN operator */
3108 pLeft = pExpr->pLeft;
3109 nVal = sqlite3ExprVectorSize(pLeft);
3110
3111 /* Construct the ephemeral table that will contain the content of
3112 ** RHS of the IN operator.
3113 */
3114 pExpr->iTable = iTab;
3115 addr = sqlite3VdbeAddOp2(v, OP_OpenEphemeral, pExpr->iTable, nVal);
3116#ifdef SQLITE_ENABLE_EXPLAIN_COMMENTS
3117 if( ExprUseXSelect(pExpr) ){
3118 VdbeComment((v, "Result of SELECT %u", pExpr->x.pSelect->selId));
3119 }else{
3120 VdbeComment((v, "RHS of IN operator"));
3121 }
3122#endif
3123 pKeyInfo = sqlite3KeyInfoAlloc(pParse->db, nVal, 1);
3124
3125 if( ExprUseXSelect(pExpr) ){
3126 /* Case 1: expr IN (SELECT ...)
3127 **
3128 ** Generate code to write the results of the select into the temporary
3129 ** table allocated and opened above.
3130 */
3131 Select *pSelect = pExpr->x.pSelect;
3132 ExprList *pEList = pSelect->pEList;
3133
3134 ExplainQueryPlan((pParse, 1, "%sLIST SUBQUERY %d",
3135 addrOnce?"":"CORRELATED ", pSelect->selId
3136 ));
3137 /* If the LHS and RHS of the IN operator do not match, that
3138 ** error will have been caught long before we reach this point. */
3139 if( ALWAYS(pEList->nExpr==nVal) ){
3140 Select *pCopy;
3141 SelectDest dest;
3142 int i;
3143 int rc;
3144 sqlite3SelectDestInit(&dest, SRT_Set, iTab);
3145 dest.zAffSdst = exprINAffinity(pParse, pExpr);
3146 pSelect->iLimit = 0;
3147 testcase( pSelect->selFlags & SF_Distinct );
3148 testcase( pKeyInfo==0 ); /* Caused by OOM in sqlite3KeyInfoAlloc() */
3149 pCopy = sqlite3SelectDup(pParse->db, pSelect, 0);
3150 rc = pParse->db->mallocFailed ? 1 :sqlite3Select(pParse, pCopy, &dest);
3151 sqlite3SelectDelete(pParse->db, pCopy);
3152 sqlite3DbFree(pParse->db, dest.zAffSdst);
3153 if( rc ){
3154 sqlite3KeyInfoUnref(pKeyInfo);
3155 return;
3156 }
3157 assert( pKeyInfo!=0 ); /* OOM will cause exit after sqlite3Select() */
3158 assert( pEList!=0 );
3159 assert( pEList->nExpr>0 );
3160 assert( sqlite3KeyInfoIsWriteable(pKeyInfo) );
3161 for(i=0; i<nVal; i++){
3162 Expr *p = sqlite3VectorFieldSubexpr(pLeft, i);
3163 pKeyInfo->aColl[i] = sqlite3BinaryCompareCollSeq(
3164 pParse, p, pEList->a[i].pExpr
3165 );
3166 }
3167 }
3168 }else if( ALWAYS(pExpr->x.pList!=0) ){
3169 /* Case 2: expr IN (exprlist)
3170 **
3171 ** For each expression, build an index key from the evaluation and
3172 ** store it in the temporary table. If <expr> is a column, then use
3173 ** that columns affinity when building index keys. If <expr> is not
3174 ** a column, use numeric affinity.
3175 */
3176 char affinity; /* Affinity of the LHS of the IN */
3177 int i;
3178 ExprList *pList = pExpr->x.pList;
3179 struct ExprList_item *pItem;
3180 int r1, r2;
3181 affinity = sqlite3ExprAffinity(pLeft);
3182 if( affinity<=SQLITE_AFF_NONE ){
3183 affinity = SQLITE_AFF_BLOB;
3184 }else if( affinity==SQLITE_AFF_REAL ){
3185 affinity = SQLITE_AFF_NUMERIC;
3186 }
3187 if( pKeyInfo ){
3188 assert( sqlite3KeyInfoIsWriteable(pKeyInfo) );
3189 pKeyInfo->aColl[0] = sqlite3ExprCollSeq(pParse, pExpr->pLeft);
3190 }
3191
3192 /* Loop through each expression in <exprlist>. */
3193 r1 = sqlite3GetTempReg(pParse);
3194 r2 = sqlite3GetTempReg(pParse);
3195 for(i=pList->nExpr, pItem=pList->a; i>0; i--, pItem++){
3196 Expr *pE2 = pItem->pExpr;
3197
3198 /* If the expression is not constant then we will need to
3199 ** disable the test that was generated above that makes sure
3200 ** this code only executes once. Because for a non-constant
3201 ** expression we need to rerun this code each time.
3202 */
3203 if( addrOnce && !sqlite3ExprIsConstant(pE2) ){
3204 sqlite3VdbeChangeToNoop(v, addrOnce-1);
3205 sqlite3VdbeChangeToNoop(v, addrOnce);
3206 ExprClearProperty(pExpr, EP_Subrtn);
3207 addrOnce = 0;
3208 }
3209
3210 /* Evaluate the expression and insert it into the temp table */
3211 sqlite3ExprCode(pParse, pE2, r1);
3212 sqlite3VdbeAddOp4(v, OP_MakeRecord, r1, 1, r2, &affinity, 1);
3213 sqlite3VdbeAddOp4Int(v, OP_IdxInsert, iTab, r2, r1, 1);
3214 }
3215 sqlite3ReleaseTempReg(pParse, r1);
3216 sqlite3ReleaseTempReg(pParse, r2);
3217 }
3218 if( pKeyInfo ){
3219 sqlite3VdbeChangeP4(v, addr, (void *)pKeyInfo, P4_KEYINFO);
3220 }
3221 if( addrOnce ){
3222 sqlite3VdbeAddOp1(v, OP_NullRow, iTab);
3223 sqlite3VdbeJumpHere(v, addrOnce);
3224 /* Subroutine return */
3225 assert( ExprUseYSub(pExpr) );
3226 assert( sqlite3VdbeGetOp(v,pExpr->y.sub.iAddr-1)->opcode==OP_BeginSubrtn
3227 || pParse->nErr );
3228 sqlite3VdbeAddOp3(v, OP_Return, pExpr->y.sub.regReturn,
3229 pExpr->y.sub.iAddr, 1);
3230 VdbeCoverage(v);
3231 sqlite3ClearTempRegCache(pParse);
3232 }
3233}
3234#endif /* SQLITE_OMIT_SUBQUERY */
3235
3236/*
3237** Generate code for scalar subqueries used as a subquery expression
3238** or EXISTS operator:
3239**
3240** (SELECT a FROM b) -- subquery
3241** EXISTS (SELECT a FROM b) -- EXISTS subquery
3242**
3243** The pExpr parameter is the SELECT or EXISTS operator to be coded.
3244**
3245** Return the register that holds the result. For a multi-column SELECT,
3246** the result is stored in a contiguous array of registers and the
3247** return value is the register of the left-most result column.
3248** Return 0 if an error occurs.
3249*/
3250#ifndef SQLITE_OMIT_SUBQUERY
3251int sqlite3CodeSubselect(Parse *pParse, Expr *pExpr){
3252 int addrOnce = 0; /* Address of OP_Once at top of subroutine */
3253 int rReg = 0; /* Register storing resulting */
3254 Select *pSel; /* SELECT statement to encode */
3255 SelectDest dest; /* How to deal with SELECT result */
3256 int nReg; /* Registers to allocate */
3257 Expr *pLimit; /* New limit expression */
3258
3259 Vdbe *v = pParse->pVdbe;
3260 assert( v!=0 );
3261 if( pParse->nErr ) return 0;
3262 testcase( pExpr->op==TK_EXISTS );
3263 testcase( pExpr->op==TK_SELECT );
3264 assert( pExpr->op==TK_EXISTS || pExpr->op==TK_SELECT );
3265 assert( ExprUseXSelect(pExpr) );
3266 pSel = pExpr->x.pSelect;
3267
3268 /* If this routine has already been coded, then invoke it as a
3269 ** subroutine. */
3270 if( ExprHasProperty(pExpr, EP_Subrtn) ){
3271 ExplainQueryPlan((pParse, 0, "REUSE SUBQUERY %d", pSel->selId));
3272 assert( ExprUseYSub(pExpr) );
3273 sqlite3VdbeAddOp2(v, OP_Gosub, pExpr->y.sub.regReturn,
3274 pExpr->y.sub.iAddr);
3275 return pExpr->iTable;
3276 }
3277
3278 /* Begin coding the subroutine */
3279 assert( !ExprUseYWin(pExpr) );
3280 assert( !ExprHasProperty(pExpr, EP_Reduced|EP_TokenOnly) );
3281 ExprSetProperty(pExpr, EP_Subrtn);
3282 pExpr->y.sub.regReturn = ++pParse->nMem;
3283 pExpr->y.sub.iAddr =
3284 sqlite3VdbeAddOp2(v, OP_BeginSubrtn, 0, pExpr->y.sub.regReturn) + 1;
3285
3286 /* The evaluation of the EXISTS/SELECT must be repeated every time it
3287 ** is encountered if any of the following is true:
3288 **
3289 ** * The right-hand side is a correlated subquery
3290 ** * The right-hand side is an expression list containing variables
3291 ** * We are inside a trigger
3292 **
3293 ** If all of the above are false, then we can run this code just once
3294 ** save the results, and reuse the same result on subsequent invocations.
3295 */
3296 if( !ExprHasProperty(pExpr, EP_VarSelect) ){
3297 addrOnce = sqlite3VdbeAddOp0(v, OP_Once); VdbeCoverage(v);
3298 }
3299
3300 /* For a SELECT, generate code to put the values for all columns of
3301 ** the first row into an array of registers and return the index of
3302 ** the first register.
3303 **
3304 ** If this is an EXISTS, write an integer 0 (not exists) or 1 (exists)
3305 ** into a register and return that register number.
3306 **
3307 ** In both cases, the query is augmented with "LIMIT 1". Any
3308 ** preexisting limit is discarded in place of the new LIMIT 1.
3309 */
3310 ExplainQueryPlan((pParse, 1, "%sSCALAR SUBQUERY %d",
3311 addrOnce?"":"CORRELATED ", pSel->selId));
3312 nReg = pExpr->op==TK_SELECT ? pSel->pEList->nExpr : 1;
3313 sqlite3SelectDestInit(&dest, 0, pParse->nMem+1);
3314 pParse->nMem += nReg;
3315 if( pExpr->op==TK_SELECT ){
3316 dest.eDest = SRT_Mem;
3317 dest.iSdst = dest.iSDParm;
3318 dest.nSdst = nReg;
3319 sqlite3VdbeAddOp3(v, OP_Null, 0, dest.iSDParm, dest.iSDParm+nReg-1);
3320 VdbeComment((v, "Init subquery result"));
3321 }else{
3322 dest.eDest = SRT_Exists;
3323 sqlite3VdbeAddOp2(v, OP_Integer, 0, dest.iSDParm);
3324 VdbeComment((v, "Init EXISTS result"));
3325 }
3326 if( pSel->pLimit ){
3327 /* The subquery already has a limit. If the pre-existing limit is X
3328 ** then make the new limit X<>0 so that the new limit is either 1 or 0 */
3329 sqlite3 *db = pParse->db;
3330 pLimit = sqlite3Expr(db, TK_INTEGER, "0");
3331 if( pLimit ){
3332 pLimit->affExpr = SQLITE_AFF_NUMERIC;
3333 pLimit = sqlite3PExpr(pParse, TK_NE,
3334 sqlite3ExprDup(db, pSel->pLimit->pLeft, 0), pLimit);
3335 }
3336 sqlite3ExprDeferredDelete(pParse, pSel->pLimit->pLeft);
3337 pSel->pLimit->pLeft = pLimit;
3338 }else{
3339 /* If there is no pre-existing limit add a limit of 1 */
3340 pLimit = sqlite3Expr(pParse->db, TK_INTEGER, "1");
3341 pSel->pLimit = sqlite3PExpr(pParse, TK_LIMIT, pLimit, 0);
3342 }
3343 pSel->iLimit = 0;
3344 if( sqlite3Select(pParse, pSel, &dest) ){
3345 pExpr->op2 = pExpr->op;
3346 pExpr->op = TK_ERROR;
3347 return 0;
3348 }
3349 pExpr->iTable = rReg = dest.iSDParm;
3350 ExprSetVVAProperty(pExpr, EP_NoReduce);
3351 if( addrOnce ){
3352 sqlite3VdbeJumpHere(v, addrOnce);
3353 }
3354
3355 /* Subroutine return */
3356 assert( ExprUseYSub(pExpr) );
3357 assert( sqlite3VdbeGetOp(v,pExpr->y.sub.iAddr-1)->opcode==OP_BeginSubrtn
3358 || pParse->nErr );
3359 sqlite3VdbeAddOp3(v, OP_Return, pExpr->y.sub.regReturn,
3360 pExpr->y.sub.iAddr, 1);
3361 VdbeCoverage(v);
3362 sqlite3ClearTempRegCache(pParse);
3363 return rReg;
3364}
3365#endif /* SQLITE_OMIT_SUBQUERY */
3366
3367#ifndef SQLITE_OMIT_SUBQUERY
3368/*
3369** Expr pIn is an IN(...) expression. This function checks that the
3370** sub-select on the RHS of the IN() operator has the same number of
3371** columns as the vector on the LHS. Or, if the RHS of the IN() is not
3372** a sub-query, that the LHS is a vector of size 1.
3373*/
3374int sqlite3ExprCheckIN(Parse *pParse, Expr *pIn){
3375 int nVector = sqlite3ExprVectorSize(pIn->pLeft);
3376 if( ExprUseXSelect(pIn) && !pParse->db->mallocFailed ){
3377 if( nVector!=pIn->x.pSelect->pEList->nExpr ){
3378 sqlite3SubselectError(pParse, pIn->x.pSelect->pEList->nExpr, nVector);
3379 return 1;
3380 }
3381 }else if( nVector!=1 ){
3382 sqlite3VectorErrorMsg(pParse, pIn->pLeft);
3383 return 1;
3384 }
3385 return 0;
3386}
3387#endif
3388
3389#ifndef SQLITE_OMIT_SUBQUERY
3390/*
3391** Generate code for an IN expression.
3392**
3393** x IN (SELECT ...)
3394** x IN (value, value, ...)
3395**
3396** The left-hand side (LHS) is a scalar or vector expression. The
3397** right-hand side (RHS) is an array of zero or more scalar values, or a
3398** subquery. If the RHS is a subquery, the number of result columns must
3399** match the number of columns in the vector on the LHS. If the RHS is
3400** a list of values, the LHS must be a scalar.
3401**
3402** The IN operator is true if the LHS value is contained within the RHS.
3403** The result is false if the LHS is definitely not in the RHS. The
3404** result is NULL if the presence of the LHS in the RHS cannot be
3405** determined due to NULLs.
3406**
3407** This routine generates code that jumps to destIfFalse if the LHS is not
3408** contained within the RHS. If due to NULLs we cannot determine if the LHS
3409** is contained in the RHS then jump to destIfNull. If the LHS is contained
3410** within the RHS then fall through.
3411**
3412** See the separate in-operator.md documentation file in the canonical
3413** SQLite source tree for additional information.
3414*/
3415static void sqlite3ExprCodeIN(
3416 Parse *pParse, /* Parsing and code generating context */
3417 Expr *pExpr, /* The IN expression */
3418 int destIfFalse, /* Jump here if LHS is not contained in the RHS */
3419 int destIfNull /* Jump here if the results are unknown due to NULLs */
3420){
3421 int rRhsHasNull = 0; /* Register that is true if RHS contains NULL values */
3422 int eType; /* Type of the RHS */
3423 int rLhs; /* Register(s) holding the LHS values */
3424 int rLhsOrig; /* LHS values prior to reordering by aiMap[] */
3425 Vdbe *v; /* Statement under construction */
3426 int *aiMap = 0; /* Map from vector field to index column */
3427 char *zAff = 0; /* Affinity string for comparisons */
3428 int nVector; /* Size of vectors for this IN operator */
3429 int iDummy; /* Dummy parameter to exprCodeVector() */
3430 Expr *pLeft; /* The LHS of the IN operator */
3431 int i; /* loop counter */
3432 int destStep2; /* Where to jump when NULLs seen in step 2 */
3433 int destStep6 = 0; /* Start of code for Step 6 */
3434 int addrTruthOp; /* Address of opcode that determines the IN is true */
3435 int destNotNull; /* Jump here if a comparison is not true in step 6 */
3436 int addrTop; /* Top of the step-6 loop */
3437 int iTab = 0; /* Index to use */
3438 u8 okConstFactor = pParse->okConstFactor;
3439
3440 assert( !ExprHasVVAProperty(pExpr,EP_Immutable) );
3441 pLeft = pExpr->pLeft;
3442 if( sqlite3ExprCheckIN(pParse, pExpr) ) return;
3443 zAff = exprINAffinity(pParse, pExpr);
3444 nVector = sqlite3ExprVectorSize(pExpr->pLeft);
3445 aiMap = (int*)sqlite3DbMallocZero(
3446 pParse->db, nVector*(sizeof(int) + sizeof(char)) + 1
3447 );
3448 if( pParse->db->mallocFailed ) goto sqlite3ExprCodeIN_oom_error;
3449
3450 /* Attempt to compute the RHS. After this step, if anything other than
3451 ** IN_INDEX_NOOP is returned, the table opened with cursor iTab
3452 ** contains the values that make up the RHS. If IN_INDEX_NOOP is returned,
3453 ** the RHS has not yet been coded. */
3454 v = pParse->pVdbe;
3455 assert( v!=0 ); /* OOM detected prior to this routine */
3456 VdbeNoopComment((v, "begin IN expr"));
3457 eType = sqlite3FindInIndex(pParse, pExpr,
3458 IN_INDEX_MEMBERSHIP | IN_INDEX_NOOP_OK,
3459 destIfFalse==destIfNull ? 0 : &rRhsHasNull,
3460 aiMap, &iTab);
3461
3462 assert( pParse->nErr || nVector==1 || eType==IN_INDEX_EPH
3463 || eType==IN_INDEX_INDEX_ASC || eType==IN_INDEX_INDEX_DESC
3464 );
3465#ifdef SQLITE_DEBUG
3466 /* Confirm that aiMap[] contains nVector integer values between 0 and
3467 ** nVector-1. */
3468 for(i=0; i<nVector; i++){
3469 int j, cnt;
3470 for(cnt=j=0; j<nVector; j++) if( aiMap[j]==i ) cnt++;
3471 assert( cnt==1 );
3472 }
3473#endif
3474
3475 /* Code the LHS, the <expr> from "<expr> IN (...)". If the LHS is a
3476 ** vector, then it is stored in an array of nVector registers starting
3477 ** at r1.
3478 **
3479 ** sqlite3FindInIndex() might have reordered the fields of the LHS vector
3480 ** so that the fields are in the same order as an existing index. The
3481 ** aiMap[] array contains a mapping from the original LHS field order to
3482 ** the field order that matches the RHS index.
3483 **
3484 ** Avoid factoring the LHS of the IN(...) expression out of the loop,
3485 ** even if it is constant, as OP_Affinity may be used on the register
3486 ** by code generated below. */
3487 assert( pParse->okConstFactor==okConstFactor );
3488 pParse->okConstFactor = 0;
3489 rLhsOrig = exprCodeVector(pParse, pLeft, &iDummy);
3490 pParse->okConstFactor = okConstFactor;
3491 for(i=0; i<nVector && aiMap[i]==i; i++){} /* Are LHS fields reordered? */
3492 if( i==nVector ){
3493 /* LHS fields are not reordered */
3494 rLhs = rLhsOrig;
3495 }else{
3496 /* Need to reorder the LHS fields according to aiMap */
3497 rLhs = sqlite3GetTempRange(pParse, nVector);
3498 for(i=0; i<nVector; i++){
3499 sqlite3VdbeAddOp3(v, OP_Copy, rLhsOrig+i, rLhs+aiMap[i], 0);
3500 }
3501 }
3502
3503 /* If sqlite3FindInIndex() did not find or create an index that is
3504 ** suitable for evaluating the IN operator, then evaluate using a
3505 ** sequence of comparisons.
3506 **
3507 ** This is step (1) in the in-operator.md optimized algorithm.
3508 */
3509 if( eType==IN_INDEX_NOOP ){
3510 ExprList *pList;
3511 CollSeq *pColl;
3512 int labelOk = sqlite3VdbeMakeLabel(pParse);
3513 int r2, regToFree;
3514 int regCkNull = 0;
3515 int ii;
3516 assert( ExprUseXList(pExpr) );
3517 pList = pExpr->x.pList;
3518 pColl = sqlite3ExprCollSeq(pParse, pExpr->pLeft);
3519 if( destIfNull!=destIfFalse ){
3520 regCkNull = sqlite3GetTempReg(pParse);
3521 sqlite3VdbeAddOp3(v, OP_BitAnd, rLhs, rLhs, regCkNull);
3522 }
3523 for(ii=0; ii<pList->nExpr; ii++){
3524 r2 = sqlite3ExprCodeTemp(pParse, pList->a[ii].pExpr, &regToFree);
3525 if( regCkNull && sqlite3ExprCanBeNull(pList->a[ii].pExpr) ){
3526 sqlite3VdbeAddOp3(v, OP_BitAnd, regCkNull, r2, regCkNull);
3527 }
3528 sqlite3ReleaseTempReg(pParse, regToFree);
3529 if( ii<pList->nExpr-1 || destIfNull!=destIfFalse ){
3530 int op = rLhs!=r2 ? OP_Eq : OP_NotNull;
3531 sqlite3VdbeAddOp4(v, op, rLhs, labelOk, r2,
3532 (void*)pColl, P4_COLLSEQ);
3533 VdbeCoverageIf(v, ii<pList->nExpr-1 && op==OP_Eq);
3534 VdbeCoverageIf(v, ii==pList->nExpr-1 && op==OP_Eq);
3535 VdbeCoverageIf(v, ii<pList->nExpr-1 && op==OP_NotNull);
3536 VdbeCoverageIf(v, ii==pList->nExpr-1 && op==OP_NotNull);
3537 sqlite3VdbeChangeP5(v, zAff[0]);
3538 }else{
3539 int op = rLhs!=r2 ? OP_Ne : OP_IsNull;
3540 assert( destIfNull==destIfFalse );
3541 sqlite3VdbeAddOp4(v, op, rLhs, destIfFalse, r2,
3542 (void*)pColl, P4_COLLSEQ);
3543 VdbeCoverageIf(v, op==OP_Ne);
3544 VdbeCoverageIf(v, op==OP_IsNull);
3545 sqlite3VdbeChangeP5(v, zAff[0] | SQLITE_JUMPIFNULL);
3546 }
3547 }
3548 if( regCkNull ){
3549 sqlite3VdbeAddOp2(v, OP_IsNull, regCkNull, destIfNull); VdbeCoverage(v);
3550 sqlite3VdbeGoto(v, destIfFalse);
3551 }
3552 sqlite3VdbeResolveLabel(v, labelOk);
3553 sqlite3ReleaseTempReg(pParse, regCkNull);
3554 goto sqlite3ExprCodeIN_finished;
3555 }
3556
3557 /* Step 2: Check to see if the LHS contains any NULL columns. If the
3558 ** LHS does contain NULLs then the result must be either FALSE or NULL.
3559 ** We will then skip the binary search of the RHS.
3560 */
3561 if( destIfNull==destIfFalse ){
3562 destStep2 = destIfFalse;
3563 }else{
3564 destStep2 = destStep6 = sqlite3VdbeMakeLabel(pParse);
3565 }
3566 for(i=0; i<nVector; i++){
3567 Expr *p = sqlite3VectorFieldSubexpr(pExpr->pLeft, i);
3568 if( pParse->nErr ) goto sqlite3ExprCodeIN_oom_error;
3569 if( sqlite3ExprCanBeNull(p) ){
3570 sqlite3VdbeAddOp2(v, OP_IsNull, rLhs+i, destStep2);
3571 VdbeCoverage(v);
3572 }
3573 }
3574
3575 /* Step 3. The LHS is now known to be non-NULL. Do the binary search
3576 ** of the RHS using the LHS as a probe. If found, the result is
3577 ** true.
3578 */
3579 if( eType==IN_INDEX_ROWID ){
3580 /* In this case, the RHS is the ROWID of table b-tree and so we also
3581 ** know that the RHS is non-NULL. Hence, we combine steps 3 and 4
3582 ** into a single opcode. */
3583 sqlite3VdbeAddOp3(v, OP_SeekRowid, iTab, destIfFalse, rLhs);
3584 VdbeCoverage(v);
3585 addrTruthOp = sqlite3VdbeAddOp0(v, OP_Goto); /* Return True */
3586 }else{
3587 sqlite3VdbeAddOp4(v, OP_Affinity, rLhs, nVector, 0, zAff, nVector);
3588 if( destIfFalse==destIfNull ){
3589 /* Combine Step 3 and Step 5 into a single opcode */
3590 sqlite3VdbeAddOp4Int(v, OP_NotFound, iTab, destIfFalse,
3591 rLhs, nVector); VdbeCoverage(v);
3592 goto sqlite3ExprCodeIN_finished;
3593 }
3594 /* Ordinary Step 3, for the case where FALSE and NULL are distinct */
3595 addrTruthOp = sqlite3VdbeAddOp4Int(v, OP_Found, iTab, 0,
3596 rLhs, nVector); VdbeCoverage(v);
3597 }
3598
3599 /* Step 4. If the RHS is known to be non-NULL and we did not find
3600 ** an match on the search above, then the result must be FALSE.
3601 */
3602 if( rRhsHasNull && nVector==1 ){
3603 sqlite3VdbeAddOp2(v, OP_NotNull, rRhsHasNull, destIfFalse);
3604 VdbeCoverage(v);
3605 }
3606
3607 /* Step 5. If we do not care about the difference between NULL and
3608 ** FALSE, then just return false.
3609 */
3610 if( destIfFalse==destIfNull ) sqlite3VdbeGoto(v, destIfFalse);
3611
3612 /* Step 6: Loop through rows of the RHS. Compare each row to the LHS.
3613 ** If any comparison is NULL, then the result is NULL. If all
3614 ** comparisons are FALSE then the final result is FALSE.
3615 **
3616 ** For a scalar LHS, it is sufficient to check just the first row
3617 ** of the RHS.
3618 */
3619 if( destStep6 ) sqlite3VdbeResolveLabel(v, destStep6);
3620 addrTop = sqlite3VdbeAddOp2(v, OP_Rewind, iTab, destIfFalse);
3621 VdbeCoverage(v);
3622 if( nVector>1 ){
3623 destNotNull = sqlite3VdbeMakeLabel(pParse);
3624 }else{
3625 /* For nVector==1, combine steps 6 and 7 by immediately returning
3626 ** FALSE if the first comparison is not NULL */
3627 destNotNull = destIfFalse;
3628 }
3629 for(i=0; i<nVector; i++){
3630 Expr *p;
3631 CollSeq *pColl;
3632 int r3 = sqlite3GetTempReg(pParse);
3633 p = sqlite3VectorFieldSubexpr(pLeft, i);
3634 pColl = sqlite3ExprCollSeq(pParse, p);
3635 sqlite3VdbeAddOp3(v, OP_Column, iTab, i, r3);
3636 sqlite3VdbeAddOp4(v, OP_Ne, rLhs+i, destNotNull, r3,
3637 (void*)pColl, P4_COLLSEQ);
3638 VdbeCoverage(v);
3639 sqlite3ReleaseTempReg(pParse, r3);
3640 }
3641 sqlite3VdbeAddOp2(v, OP_Goto, 0, destIfNull);
3642 if( nVector>1 ){
3643 sqlite3VdbeResolveLabel(v, destNotNull);
3644 sqlite3VdbeAddOp2(v, OP_Next, iTab, addrTop+1);
3645 VdbeCoverage(v);
3646
3647 /* Step 7: If we reach this point, we know that the result must
3648 ** be false. */
3649 sqlite3VdbeAddOp2(v, OP_Goto, 0, destIfFalse);
3650 }
3651
3652 /* Jumps here in order to return true. */
3653 sqlite3VdbeJumpHere(v, addrTruthOp);
3654
3655sqlite3ExprCodeIN_finished:
3656 if( rLhs!=rLhsOrig ) sqlite3ReleaseTempReg(pParse, rLhs);
3657 VdbeComment((v, "end IN expr"));
3658sqlite3ExprCodeIN_oom_error:
3659 sqlite3DbFree(pParse->db, aiMap);
3660 sqlite3DbFree(pParse->db, zAff);
3661}
3662#endif /* SQLITE_OMIT_SUBQUERY */
3663
3664#ifndef SQLITE_OMIT_FLOATING_POINT
3665/*
3666** Generate an instruction that will put the floating point
3667** value described by z[0..n-1] into register iMem.
3668**
3669** The z[] string will probably not be zero-terminated. But the
3670** z[n] character is guaranteed to be something that does not look
3671** like the continuation of the number.
3672*/
3673static void codeReal(Vdbe *v, const char *z, int negateFlag, int iMem){
3674 if( ALWAYS(z!=0) ){
3675 double value;
3676 sqlite3AtoF(z, &value, sqlite3Strlen30(z), SQLITE_UTF8);
3677 assert( !sqlite3IsNaN(value) ); /* The new AtoF never returns NaN */
3678 if( negateFlag ) value = -value;
3679 sqlite3VdbeAddOp4Dup8(v, OP_Real, 0, iMem, 0, (u8*)&value, P4_REAL);
3680 }
3681}
3682#endif
3683
3684
3685/*
3686** Generate an instruction that will put the integer describe by
3687** text z[0..n-1] into register iMem.
3688**
3689** Expr.u.zToken is always UTF8 and zero-terminated.
3690*/
3691static void codeInteger(Parse *pParse, Expr *pExpr, int negFlag, int iMem){
3692 Vdbe *v = pParse->pVdbe;
3693 if( pExpr->flags & EP_IntValue ){
3694 int i = pExpr->u.iValue;
3695 assert( i>=0 );
3696 if( negFlag ) i = -i;
3697 sqlite3VdbeAddOp2(v, OP_Integer, i, iMem);
3698 }else{
3699 int c;
3700 i64 value;
3701 const char *z = pExpr->u.zToken;
3702 assert( z!=0 );
3703 c = sqlite3DecOrHexToI64(z, &value);
3704 if( (c==3 && !negFlag) || (c==2) || (negFlag && value==SMALLEST_INT64)){
3705#ifdef SQLITE_OMIT_FLOATING_POINT
3706 sqlite3ErrorMsg(pParse, "oversized integer: %s%#T", negFlag?"-":"",pExpr);
3707#else
3708#ifndef SQLITE_OMIT_HEX_INTEGER
3709 if( sqlite3_strnicmp(z,"0x",2)==0 ){
3710 sqlite3ErrorMsg(pParse, "hex literal too big: %s%#T",
3711 negFlag?"-":"",pExpr);
3712 }else
3713#endif
3714 {
3715 codeReal(v, z, negFlag, iMem);
3716 }
3717#endif
3718 }else{
3719 if( negFlag ){ value = c==3 ? SMALLEST_INT64 : -value; }
3720 sqlite3VdbeAddOp4Dup8(v, OP_Int64, 0, iMem, 0, (u8*)&value, P4_INT64);
3721 }
3722 }
3723}
3724
3725
3726/* Generate code that will load into register regOut a value that is
3727** appropriate for the iIdxCol-th column of index pIdx.
3728*/
3729void sqlite3ExprCodeLoadIndexColumn(
3730 Parse *pParse, /* The parsing context */
3731 Index *pIdx, /* The index whose column is to be loaded */
3732 int iTabCur, /* Cursor pointing to a table row */
3733 int iIdxCol, /* The column of the index to be loaded */
3734 int regOut /* Store the index column value in this register */
3735){
3736 i16 iTabCol = pIdx->aiColumn[iIdxCol];
3737 if( iTabCol==XN_EXPR ){
3738 assert( pIdx->aColExpr );
3739 assert( pIdx->aColExpr->nExpr>iIdxCol );
3740 pParse->iSelfTab = iTabCur + 1;
3741 sqlite3ExprCodeCopy(pParse, pIdx->aColExpr->a[iIdxCol].pExpr, regOut);
3742 pParse->iSelfTab = 0;
3743 }else{
3744 sqlite3ExprCodeGetColumnOfTable(pParse->pVdbe, pIdx->pTable, iTabCur,
3745 iTabCol, regOut);
3746 }
3747}
3748
3749#ifndef SQLITE_OMIT_GENERATED_COLUMNS
3750/*
3751** Generate code that will compute the value of generated column pCol
3752** and store the result in register regOut
3753*/
3754void sqlite3ExprCodeGeneratedColumn(
3755 Parse *pParse, /* Parsing context */
3756 Table *pTab, /* Table containing the generated column */
3757 Column *pCol, /* The generated column */
3758 int regOut /* Put the result in this register */
3759){
3760 int iAddr;
3761 Vdbe *v = pParse->pVdbe;
3762 assert( v!=0 );
3763 assert( pParse->iSelfTab!=0 );
3764 if( pParse->iSelfTab>0 ){
3765 iAddr = sqlite3VdbeAddOp3(v, OP_IfNullRow, pParse->iSelfTab-1, 0, regOut);
3766 }else{
3767 iAddr = 0;
3768 }
3769 sqlite3ExprCodeCopy(pParse, sqlite3ColumnExpr(pTab,pCol), regOut);
3770 if( pCol->affinity>=SQLITE_AFF_TEXT ){
3771 sqlite3VdbeAddOp4(v, OP_Affinity, regOut, 1, 0, &pCol->affinity, 1);
3772 }
3773 if( iAddr ) sqlite3VdbeJumpHere(v, iAddr);
3774}
3775#endif /* SQLITE_OMIT_GENERATED_COLUMNS */
3776
3777/*
3778** Generate code to extract the value of the iCol-th column of a table.
3779*/
3780void sqlite3ExprCodeGetColumnOfTable(
3781 Vdbe *v, /* Parsing context */
3782 Table *pTab, /* The table containing the value */
3783 int iTabCur, /* The table cursor. Or the PK cursor for WITHOUT ROWID */
3784 int iCol, /* Index of the column to extract */
3785 int regOut /* Extract the value into this register */
3786){
3787 Column *pCol;
3788 assert( v!=0 );
3789 assert( pTab!=0 );
3790 if( iCol<0 || iCol==pTab->iPKey ){
3791 sqlite3VdbeAddOp2(v, OP_Rowid, iTabCur, regOut);
3792 VdbeComment((v, "%s.rowid", pTab->zName));
3793 }else{
3794 int op;
3795 int x;
3796 if( IsVirtual(pTab) ){
3797 op = OP_VColumn;
3798 x = iCol;
3799#ifndef SQLITE_OMIT_GENERATED_COLUMNS
3800 }else if( (pCol = &pTab->aCol[iCol])->colFlags & COLFLAG_VIRTUAL ){
3801 Parse *pParse = sqlite3VdbeParser(v);
3802 if( pCol->colFlags & COLFLAG_BUSY ){
3803 sqlite3ErrorMsg(pParse, "generated column loop on \"%s\"",
3804 pCol->zCnName);
3805 }else{
3806 int savedSelfTab = pParse->iSelfTab;
3807 pCol->colFlags |= COLFLAG_BUSY;
3808 pParse->iSelfTab = iTabCur+1;
3809 sqlite3ExprCodeGeneratedColumn(pParse, pTab, pCol, regOut);
3810 pParse->iSelfTab = savedSelfTab;
3811 pCol->colFlags &= ~COLFLAG_BUSY;
3812 }
3813 return;
3814#endif
3815 }else if( !HasRowid(pTab) ){
3816 testcase( iCol!=sqlite3TableColumnToStorage(pTab, iCol) );
3817 x = sqlite3TableColumnToIndex(sqlite3PrimaryKeyIndex(pTab), iCol);
3818 op = OP_Column;
3819 }else{
3820 x = sqlite3TableColumnToStorage(pTab,iCol);
3821 testcase( x!=iCol );
3822 op = OP_Column;
3823 }
3824 sqlite3VdbeAddOp3(v, op, iTabCur, x, regOut);
3825 sqlite3ColumnDefault(v, pTab, iCol, regOut);
3826 }
3827}
3828
3829/*
3830** Generate code that will extract the iColumn-th column from
3831** table pTab and store the column value in register iReg.
3832**
3833** There must be an open cursor to pTab in iTable when this routine
3834** is called. If iColumn<0 then code is generated that extracts the rowid.
3835*/
3836int sqlite3ExprCodeGetColumn(
3837 Parse *pParse, /* Parsing and code generating context */
3838 Table *pTab, /* Description of the table we are reading from */
3839 int iColumn, /* Index of the table column */
3840 int iTable, /* The cursor pointing to the table */
3841 int iReg, /* Store results here */
3842 u8 p5 /* P5 value for OP_Column + FLAGS */
3843){
3844 assert( pParse->pVdbe!=0 );
3845 sqlite3ExprCodeGetColumnOfTable(pParse->pVdbe, pTab, iTable, iColumn, iReg);
3846 if( p5 ){
3847 VdbeOp *pOp = sqlite3VdbeGetLastOp(pParse->pVdbe);
3848 if( pOp->opcode==OP_Column ) pOp->p5 = p5;
3849 }
3850 return iReg;
3851}
3852
3853/*
3854** Generate code to move content from registers iFrom...iFrom+nReg-1
3855** over to iTo..iTo+nReg-1.
3856*/
3857void sqlite3ExprCodeMove(Parse *pParse, int iFrom, int iTo, int nReg){
3858 sqlite3VdbeAddOp3(pParse->pVdbe, OP_Move, iFrom, iTo, nReg);
3859}
3860
3861/*
3862** Convert a scalar expression node to a TK_REGISTER referencing
3863** register iReg. The caller must ensure that iReg already contains
3864** the correct value for the expression.
3865*/
3866static void exprToRegister(Expr *pExpr, int iReg){
3867 Expr *p = sqlite3ExprSkipCollateAndLikely(pExpr);
3868 if( NEVER(p==0) ) return;
3869 p->op2 = p->op;
3870 p->op = TK_REGISTER;
3871 p->iTable = iReg;
3872 ExprClearProperty(p, EP_Skip);
3873}
3874
3875/*
3876** Evaluate an expression (either a vector or a scalar expression) and store
3877** the result in continguous temporary registers. Return the index of
3878** the first register used to store the result.
3879**
3880** If the returned result register is a temporary scalar, then also write
3881** that register number into *piFreeable. If the returned result register
3882** is not a temporary or if the expression is a vector set *piFreeable
3883** to 0.
3884*/
3885static int exprCodeVector(Parse *pParse, Expr *p, int *piFreeable){
3886 int iResult;
3887 int nResult = sqlite3ExprVectorSize(p);
3888 if( nResult==1 ){
3889 iResult = sqlite3ExprCodeTemp(pParse, p, piFreeable);
3890 }else{
3891 *piFreeable = 0;
3892 if( p->op==TK_SELECT ){
3893#if SQLITE_OMIT_SUBQUERY
3894 iResult = 0;
3895#else
3896 iResult = sqlite3CodeSubselect(pParse, p);
3897#endif
3898 }else{
3899 int i;
3900 iResult = pParse->nMem+1;
3901 pParse->nMem += nResult;
3902 assert( ExprUseXList(p) );
3903 for(i=0; i<nResult; i++){
3904 sqlite3ExprCodeFactorable(pParse, p->x.pList->a[i].pExpr, i+iResult);
3905 }
3906 }
3907 }
3908 return iResult;
3909}
3910
3911/*
3912** If the last opcode is a OP_Copy, then set the do-not-merge flag (p5)
3913** so that a subsequent copy will not be merged into this one.
3914*/
3915static void setDoNotMergeFlagOnCopy(Vdbe *v){
3916 if( sqlite3VdbeGetLastOp(v)->opcode==OP_Copy ){
3917 sqlite3VdbeChangeP5(v, 1); /* Tag trailing OP_Copy as not mergable */
3918 }
3919}
3920
3921/*
3922** Generate code to implement special SQL functions that are implemented
3923** in-line rather than by using the usual callbacks.
3924*/
3925static int exprCodeInlineFunction(
3926 Parse *pParse, /* Parsing context */
3927 ExprList *pFarg, /* List of function arguments */
3928 int iFuncId, /* Function ID. One of the INTFUNC_... values */
3929 int target /* Store function result in this register */
3930){
3931 int nFarg;
3932 Vdbe *v = pParse->pVdbe;
3933 assert( v!=0 );
3934 assert( pFarg!=0 );
3935 nFarg = pFarg->nExpr;
3936 assert( nFarg>0 ); /* All in-line functions have at least one argument */
3937 switch( iFuncId ){
3938 case INLINEFUNC_coalesce: {
3939 /* Attempt a direct implementation of the built-in COALESCE() and
3940 ** IFNULL() functions. This avoids unnecessary evaluation of
3941 ** arguments past the first non-NULL argument.
3942 */
3943 int endCoalesce = sqlite3VdbeMakeLabel(pParse);
3944 int i;
3945 assert( nFarg>=2 );
3946 sqlite3ExprCode(pParse, pFarg->a[0].pExpr, target);
3947 for(i=1; i<nFarg; i++){
3948 sqlite3VdbeAddOp2(v, OP_NotNull, target, endCoalesce);
3949 VdbeCoverage(v);
3950 sqlite3ExprCode(pParse, pFarg->a[i].pExpr, target);
3951 }
3952 setDoNotMergeFlagOnCopy(v);
3953 sqlite3VdbeResolveLabel(v, endCoalesce);
3954 break;
3955 }
3956 case INLINEFUNC_iif: {
3957 Expr caseExpr;
3958 memset(&caseExpr, 0, sizeof(caseExpr));
3959 caseExpr.op = TK_CASE;
3960 caseExpr.x.pList = pFarg;
3961 return sqlite3ExprCodeTarget(pParse, &caseExpr, target);
3962 }
3963#ifdef SQLITE_ENABLE_OFFSET_SQL_FUNC
3964 case INLINEFUNC_sqlite_offset: {
3965 Expr *pArg = pFarg->a[0].pExpr;
3966 if( pArg->op==TK_COLUMN && pArg->iTable>=0 ){
3967 sqlite3VdbeAddOp3(v, OP_Offset, pArg->iTable, pArg->iColumn, target);
3968 }else{
3969 sqlite3VdbeAddOp2(v, OP_Null, 0, target);
3970 }
3971 break;
3972 }
3973#endif
3974 default: {
3975 /* The UNLIKELY() function is a no-op. The result is the value
3976 ** of the first argument.
3977 */
3978 assert( nFarg==1 || nFarg==2 );
3979 target = sqlite3ExprCodeTarget(pParse, pFarg->a[0].pExpr, target);
3980 break;
3981 }
3982
3983 /***********************************************************************
3984 ** Test-only SQL functions that are only usable if enabled
3985 ** via SQLITE_TESTCTRL_INTERNAL_FUNCTIONS
3986 */
3987#if !defined(SQLITE_UNTESTABLE)
3988 case INLINEFUNC_expr_compare: {
3989 /* Compare two expressions using sqlite3ExprCompare() */
3990 assert( nFarg==2 );
3991 sqlite3VdbeAddOp2(v, OP_Integer,
3992 sqlite3ExprCompare(0,pFarg->a[0].pExpr, pFarg->a[1].pExpr,-1),
3993 target);
3994 break;
3995 }
3996
3997 case INLINEFUNC_expr_implies_expr: {
3998 /* Compare two expressions using sqlite3ExprImpliesExpr() */
3999 assert( nFarg==2 );
4000 sqlite3VdbeAddOp2(v, OP_Integer,
4001 sqlite3ExprImpliesExpr(pParse,pFarg->a[0].pExpr, pFarg->a[1].pExpr,-1),
4002 target);
4003 break;
4004 }
4005
4006 case INLINEFUNC_implies_nonnull_row: {
4007 /* REsult of sqlite3ExprImpliesNonNullRow() */
4008 Expr *pA1;
4009 assert( nFarg==2 );
4010 pA1 = pFarg->a[1].pExpr;
4011 if( pA1->op==TK_COLUMN ){
4012 sqlite3VdbeAddOp2(v, OP_Integer,
4013 sqlite3ExprImpliesNonNullRow(pFarg->a[0].pExpr,pA1->iTable),
4014 target);
4015 }else{
4016 sqlite3VdbeAddOp2(v, OP_Null, 0, target);
4017 }
4018 break;
4019 }
4020
4021 case INLINEFUNC_affinity: {
4022 /* The AFFINITY() function evaluates to a string that describes
4023 ** the type affinity of the argument. This is used for testing of
4024 ** the SQLite type logic.
4025 */
4026 const char *azAff[] = { "blob", "text", "numeric", "integer", "real" };
4027 char aff;
4028 assert( nFarg==1 );
4029 aff = sqlite3ExprAffinity(pFarg->a[0].pExpr);
4030 sqlite3VdbeLoadString(v, target,
4031 (aff<=SQLITE_AFF_NONE) ? "none" : azAff[aff-SQLITE_AFF_BLOB]);
4032 break;
4033 }
4034#endif /* !defined(SQLITE_UNTESTABLE) */
4035 }
4036 return target;
4037}
4038
4039/*
4040** Check to see if pExpr is one of the indexed expressions on pParse->pIdxExpr.
4041** If it is, then resolve the expression by reading from the index and
4042** return the register into which the value has been read. If pExpr is
4043** not an indexed expression, then return negative.
4044*/
4045static SQLITE_NOINLINE int sqlite3IndexedExprLookup(
4046 Parse *pParse, /* The parsing context */
4047 Expr *pExpr, /* The expression to potentially bypass */
4048 int target /* Where to store the result of the expression */
4049){
4050 IndexedExpr *p;
4051 Vdbe *v;
4052 for(p=pParse->pIdxExpr; p; p=p->pIENext){
4053 int iDataCur = p->iDataCur;
4054 if( iDataCur<0 ) continue;
4055 if( pParse->iSelfTab ){
4056 if( p->iDataCur!=pParse->iSelfTab-1 ) continue;
4057 iDataCur = -1;
4058 }
4059 if( sqlite3ExprCompare(0, pExpr, p->pExpr, iDataCur)!=0 ) continue;
4060 v = pParse->pVdbe;
4061 assert( v!=0 );
4062 if( p->bMaybeNullRow ){
4063 /* If the index is on a NULL row due to an outer join, then we
4064 ** cannot extract the value from the index. The value must be
4065 ** computed using the original expression. */
4066 int addr = sqlite3VdbeCurrentAddr(v);
4067 sqlite3VdbeAddOp3(v, OP_IfNullRow, p->iIdxCur, addr+3, target);
4068 VdbeCoverage(v);
4069 sqlite3VdbeAddOp3(v, OP_Column, p->iIdxCur, p->iIdxCol, target);
4070 VdbeComment((v, "%s expr-column %d", p->zIdxName, p->iIdxCol));
4071 sqlite3VdbeGoto(v, 0);
4072 p = pParse->pIdxExpr;
4073 pParse->pIdxExpr = 0;
4074 sqlite3ExprCode(pParse, pExpr, target);
4075 pParse->pIdxExpr = p;
4076 sqlite3VdbeJumpHere(v, addr+2);
4077 }else{
4078 sqlite3VdbeAddOp3(v, OP_Column, p->iIdxCur, p->iIdxCol, target);
4079 VdbeComment((v, "%s expr-column %d", p->zIdxName, p->iIdxCol));
4080 }
4081 return target;
4082 }
4083 return -1; /* Not found */
4084}
4085
4086
4087/*
4088** Generate code into the current Vdbe to evaluate the given
4089** expression. Attempt to store the results in register "target".
4090** Return the register where results are stored.
4091**
4092** With this routine, there is no guarantee that results will
4093** be stored in target. The result might be stored in some other
4094** register if it is convenient to do so. The calling function
4095** must check the return code and move the results to the desired
4096** register.
4097*/
4098int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target){
4099 Vdbe *v = pParse->pVdbe; /* The VM under construction */
4100 int op; /* The opcode being coded */
4101 int inReg = target; /* Results stored in register inReg */
4102 int regFree1 = 0; /* If non-zero free this temporary register */
4103 int regFree2 = 0; /* If non-zero free this temporary register */
4104 int r1, r2; /* Various register numbers */
4105 Expr tempX; /* Temporary expression node */
4106 int p5 = 0;
4107
4108 assert( target>0 && target<=pParse->nMem );
4109 assert( v!=0 );
4110
4111expr_code_doover:
4112 if( pExpr==0 ){
4113 op = TK_NULL;
4114 }else if( pParse->pIdxExpr!=0
4115 && !ExprHasProperty(pExpr, EP_Leaf)
4116 && (r1 = sqlite3IndexedExprLookup(pParse, pExpr, target))>=0
4117 ){
4118 return r1;
4119 }else{
4120 assert( !ExprHasVVAProperty(pExpr,EP_Immutable) );
4121 op = pExpr->op;
4122 }
4123 switch( op ){
4124 case TK_AGG_COLUMN: {
4125 AggInfo *pAggInfo = pExpr->pAggInfo;
4126 struct AggInfo_col *pCol;
4127 assert( pAggInfo!=0 );
4128 assert( pExpr->iAgg>=0 && pExpr->iAgg<pAggInfo->nColumn );
4129 pCol = &pAggInfo->aCol[pExpr->iAgg];
4130 if( !pAggInfo->directMode ){
4131 assert( pCol->iMem>0 );
4132 return pCol->iMem;
4133 }else if( pAggInfo->useSortingIdx ){
4134 Table *pTab = pCol->pTab;
4135 sqlite3VdbeAddOp3(v, OP_Column, pAggInfo->sortingIdxPTab,
4136 pCol->iSorterColumn, target);
4137 if( pCol->iColumn<0 ){
4138 VdbeComment((v,"%s.rowid",pTab->zName));
4139 }else if( ALWAYS(pTab!=0) ){
4140 VdbeComment((v,"%s.%s",
4141 pTab->zName, pTab->aCol[pCol->iColumn].zCnName));
4142 if( pTab->aCol[pCol->iColumn].affinity==SQLITE_AFF_REAL ){
4143 sqlite3VdbeAddOp1(v, OP_RealAffinity, target);
4144 }
4145 }
4146 return target;
4147 }
4148 /* Otherwise, fall thru into the TK_COLUMN case */
4149 /* no break */ deliberate_fall_through
4150 }
4151 case TK_COLUMN: {
4152 int iTab = pExpr->iTable;
4153 int iReg;
4154 if( ExprHasProperty(pExpr, EP_FixedCol) ){
4155 /* This COLUMN expression is really a constant due to WHERE clause
4156 ** constraints, and that constant is coded by the pExpr->pLeft
4157 ** expresssion. However, make sure the constant has the correct
4158 ** datatype by applying the Affinity of the table column to the
4159 ** constant.
4160 */
4161 int aff;
4162 iReg = sqlite3ExprCodeTarget(pParse, pExpr->pLeft,target);
4163 assert( ExprUseYTab(pExpr) );
4164 assert( pExpr->y.pTab!=0 );
4165 aff = sqlite3TableColumnAffinity(pExpr->y.pTab, pExpr->iColumn);
4166 if( aff>SQLITE_AFF_BLOB ){
4167 static const char zAff[] = "B\000C\000D\000E";
4168 assert( SQLITE_AFF_BLOB=='A' );
4169 assert( SQLITE_AFF_TEXT=='B' );
4170 sqlite3VdbeAddOp4(v, OP_Affinity, iReg, 1, 0,
4171 &zAff[(aff-'B')*2], P4_STATIC);
4172 }
4173 return iReg;
4174 }
4175 if( iTab<0 ){
4176 if( pParse->iSelfTab<0 ){
4177 /* Other columns in the same row for CHECK constraints or
4178 ** generated columns or for inserting into partial index.
4179 ** The row is unpacked into registers beginning at
4180 ** 0-(pParse->iSelfTab). The rowid (if any) is in a register
4181 ** immediately prior to the first column.
4182 */
4183 Column *pCol;
4184 Table *pTab;
4185 int iSrc;
4186 int iCol = pExpr->iColumn;
4187 assert( ExprUseYTab(pExpr) );
4188 pTab = pExpr->y.pTab;
4189 assert( pTab!=0 );
4190 assert( iCol>=XN_ROWID );
4191 assert( iCol<pTab->nCol );
4192 if( iCol<0 ){
4193 return -1-pParse->iSelfTab;
4194 }
4195 pCol = pTab->aCol + iCol;
4196 testcase( iCol!=sqlite3TableColumnToStorage(pTab,iCol) );
4197 iSrc = sqlite3TableColumnToStorage(pTab, iCol) - pParse->iSelfTab;
4198#ifndef SQLITE_OMIT_GENERATED_COLUMNS
4199 if( pCol->colFlags & COLFLAG_GENERATED ){
4200 if( pCol->colFlags & COLFLAG_BUSY ){
4201 sqlite3ErrorMsg(pParse, "generated column loop on \"%s\"",
4202 pCol->zCnName);
4203 return 0;
4204 }
4205 pCol->colFlags |= COLFLAG_BUSY;
4206 if( pCol->colFlags & COLFLAG_NOTAVAIL ){
4207 sqlite3ExprCodeGeneratedColumn(pParse, pTab, pCol, iSrc);
4208 }
4209 pCol->colFlags &= ~(COLFLAG_BUSY|COLFLAG_NOTAVAIL);
4210 return iSrc;
4211 }else
4212#endif /* SQLITE_OMIT_GENERATED_COLUMNS */
4213 if( pCol->affinity==SQLITE_AFF_REAL ){
4214 sqlite3VdbeAddOp2(v, OP_SCopy, iSrc, target);
4215 sqlite3VdbeAddOp1(v, OP_RealAffinity, target);
4216 return target;
4217 }else{
4218 return iSrc;
4219 }
4220 }else{
4221 /* Coding an expression that is part of an index where column names
4222 ** in the index refer to the table to which the index belongs */
4223 iTab = pParse->iSelfTab - 1;
4224 }
4225 }
4226 assert( ExprUseYTab(pExpr) );
4227 assert( pExpr->y.pTab!=0 );
4228 iReg = sqlite3ExprCodeGetColumn(pParse, pExpr->y.pTab,
4229 pExpr->iColumn, iTab, target,
4230 pExpr->op2);
4231 return iReg;
4232 }
4233 case TK_INTEGER: {
4234 codeInteger(pParse, pExpr, 0, target);
4235 return target;
4236 }
4237 case TK_TRUEFALSE: {
4238 sqlite3VdbeAddOp2(v, OP_Integer, sqlite3ExprTruthValue(pExpr), target);
4239 return target;
4240 }
4241#ifndef SQLITE_OMIT_FLOATING_POINT
4242 case TK_FLOAT: {
4243 assert( !ExprHasProperty(pExpr, EP_IntValue) );
4244 codeReal(v, pExpr->u.zToken, 0, target);
4245 return target;
4246 }
4247#endif
4248 case TK_STRING: {
4249 assert( !ExprHasProperty(pExpr, EP_IntValue) );
4250 sqlite3VdbeLoadString(v, target, pExpr->u.zToken);
4251 return target;
4252 }
4253 default: {
4254 /* Make NULL the default case so that if a bug causes an illegal
4255 ** Expr node to be passed into this function, it will be handled
4256 ** sanely and not crash. But keep the assert() to bring the problem
4257 ** to the attention of the developers. */
4258 assert( op==TK_NULL || op==TK_ERROR || pParse->db->mallocFailed );
4259 sqlite3VdbeAddOp2(v, OP_Null, 0, target);
4260 return target;
4261 }
4262#ifndef SQLITE_OMIT_BLOB_LITERAL
4263 case TK_BLOB: {
4264 int n;
4265 const char *z;
4266 char *zBlob;
4267 assert( !ExprHasProperty(pExpr, EP_IntValue) );
4268 assert( pExpr->u.zToken[0]=='x' || pExpr->u.zToken[0]=='X' );
4269 assert( pExpr->u.zToken[1]=='\'' );
4270 z = &pExpr->u.zToken[2];
4271 n = sqlite3Strlen30(z) - 1;
4272 assert( z[n]=='\'' );
4273 zBlob = sqlite3HexToBlob(sqlite3VdbeDb(v), z, n);
4274 sqlite3VdbeAddOp4(v, OP_Blob, n/2, target, 0, zBlob, P4_DYNAMIC);
4275 return target;
4276 }
4277#endif
4278 case TK_VARIABLE: {
4279 assert( !ExprHasProperty(pExpr, EP_IntValue) );
4280 assert( pExpr->u.zToken!=0 );
4281 assert( pExpr->u.zToken[0]!=0 );
4282 sqlite3VdbeAddOp2(v, OP_Variable, pExpr->iColumn, target);
4283 if( pExpr->u.zToken[1]!=0 ){
4284 const char *z = sqlite3VListNumToName(pParse->pVList, pExpr->iColumn);
4285 assert( pExpr->u.zToken[0]=='?' || (z && !strcmp(pExpr->u.zToken, z)) );
4286 pParse->pVList[0] = 0; /* Indicate VList may no longer be enlarged */
4287 sqlite3VdbeAppendP4(v, (char*)z, P4_STATIC);
4288 }
4289 return target;
4290 }
4291 case TK_REGISTER: {
4292 return pExpr->iTable;
4293 }
4294#ifndef SQLITE_OMIT_CAST
4295 case TK_CAST: {
4296 /* Expressions of the form: CAST(pLeft AS token) */
4297 inReg = sqlite3ExprCodeTarget(pParse, pExpr->pLeft, target);
4298 if( inReg!=target ){
4299 sqlite3VdbeAddOp2(v, OP_SCopy, inReg, target);
4300 inReg = target;
4301 }
4302 assert( !ExprHasProperty(pExpr, EP_IntValue) );
4303 sqlite3VdbeAddOp2(v, OP_Cast, target,
4304 sqlite3AffinityType(pExpr->u.zToken, 0));
4305 return inReg;
4306 }
4307#endif /* SQLITE_OMIT_CAST */
4308 case TK_IS:
4309 case TK_ISNOT:
4310 op = (op==TK_IS) ? TK_EQ : TK_NE;
4311 p5 = SQLITE_NULLEQ;
4312 /* fall-through */
4313 case TK_LT:
4314 case TK_LE:
4315 case TK_GT:
4316 case TK_GE:
4317 case TK_NE:
4318 case TK_EQ: {
4319 Expr *pLeft = pExpr->pLeft;
4320 if( sqlite3ExprIsVector(pLeft) ){
4321 codeVectorCompare(pParse, pExpr, target, op, p5);
4322 }else{
4323 r1 = sqlite3ExprCodeTemp(pParse, pLeft, &regFree1);
4324 r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, &regFree2);
4325 sqlite3VdbeAddOp2(v, OP_Integer, 1, inReg);
4326 codeCompare(pParse, pLeft, pExpr->pRight, op, r1, r2,
4327 sqlite3VdbeCurrentAddr(v)+2, p5,
4328 ExprHasProperty(pExpr,EP_Commuted));
4329 assert(TK_LT==OP_Lt); testcase(op==OP_Lt); VdbeCoverageIf(v,op==OP_Lt);
4330 assert(TK_LE==OP_Le); testcase(op==OP_Le); VdbeCoverageIf(v,op==OP_Le);
4331 assert(TK_GT==OP_Gt); testcase(op==OP_Gt); VdbeCoverageIf(v,op==OP_Gt);
4332 assert(TK_GE==OP_Ge); testcase(op==OP_Ge); VdbeCoverageIf(v,op==OP_Ge);
4333 assert(TK_EQ==OP_Eq); testcase(op==OP_Eq); VdbeCoverageIf(v,op==OP_Eq);
4334 assert(TK_NE==OP_Ne); testcase(op==OP_Ne); VdbeCoverageIf(v,op==OP_Ne);
4335 if( p5==SQLITE_NULLEQ ){
4336 sqlite3VdbeAddOp2(v, OP_Integer, 0, inReg);
4337 }else{
4338 sqlite3VdbeAddOp3(v, OP_ZeroOrNull, r1, inReg, r2);
4339 }
4340 testcase( regFree1==0 );
4341 testcase( regFree2==0 );
4342 }
4343 break;
4344 }
4345 case TK_AND:
4346 case TK_OR:
4347 case TK_PLUS:
4348 case TK_STAR:
4349 case TK_MINUS:
4350 case TK_REM:
4351 case TK_BITAND:
4352 case TK_BITOR:
4353 case TK_SLASH:
4354 case TK_LSHIFT:
4355 case TK_RSHIFT:
4356 case TK_CONCAT: {
4357 assert( TK_AND==OP_And ); testcase( op==TK_AND );
4358 assert( TK_OR==OP_Or ); testcase( op==TK_OR );
4359 assert( TK_PLUS==OP_Add ); testcase( op==TK_PLUS );
4360 assert( TK_MINUS==OP_Subtract ); testcase( op==TK_MINUS );
4361 assert( TK_REM==OP_Remainder ); testcase( op==TK_REM );
4362 assert( TK_BITAND==OP_BitAnd ); testcase( op==TK_BITAND );
4363 assert( TK_BITOR==OP_BitOr ); testcase( op==TK_BITOR );
4364 assert( TK_SLASH==OP_Divide ); testcase( op==TK_SLASH );
4365 assert( TK_LSHIFT==OP_ShiftLeft ); testcase( op==TK_LSHIFT );
4366 assert( TK_RSHIFT==OP_ShiftRight ); testcase( op==TK_RSHIFT );
4367 assert( TK_CONCAT==OP_Concat ); testcase( op==TK_CONCAT );
4368 r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, &regFree1);
4369 r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, &regFree2);
4370 sqlite3VdbeAddOp3(v, op, r2, r1, target);
4371 testcase( regFree1==0 );
4372 testcase( regFree2==0 );
4373 break;
4374 }
4375 case TK_UMINUS: {
4376 Expr *pLeft = pExpr->pLeft;
4377 assert( pLeft );
4378 if( pLeft->op==TK_INTEGER ){
4379 codeInteger(pParse, pLeft, 1, target);
4380 return target;
4381#ifndef SQLITE_OMIT_FLOATING_POINT
4382 }else if( pLeft->op==TK_FLOAT ){
4383 assert( !ExprHasProperty(pExpr, EP_IntValue) );
4384 codeReal(v, pLeft->u.zToken, 1, target);
4385 return target;
4386#endif
4387 }else{
4388 tempX.op = TK_INTEGER;
4389 tempX.flags = EP_IntValue|EP_TokenOnly;
4390 tempX.u.iValue = 0;
4391 ExprClearVVAProperties(&tempX);
4392 r1 = sqlite3ExprCodeTemp(pParse, &tempX, &regFree1);
4393 r2 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, &regFree2);
4394 sqlite3VdbeAddOp3(v, OP_Subtract, r2, r1, target);
4395 testcase( regFree2==0 );
4396 }
4397 break;
4398 }
4399 case TK_BITNOT:
4400 case TK_NOT: {
4401 assert( TK_BITNOT==OP_BitNot ); testcase( op==TK_BITNOT );
4402 assert( TK_NOT==OP_Not ); testcase( op==TK_NOT );
4403 r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, &regFree1);
4404 testcase( regFree1==0 );
4405 sqlite3VdbeAddOp2(v, op, r1, inReg);
4406 break;
4407 }
4408 case TK_TRUTH: {
4409 int isTrue; /* IS TRUE or IS NOT TRUE */
4410 int bNormal; /* IS TRUE or IS FALSE */
4411 r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, &regFree1);
4412 testcase( regFree1==0 );
4413 isTrue = sqlite3ExprTruthValue(pExpr->pRight);
4414 bNormal = pExpr->op2==TK_IS;
4415 testcase( isTrue && bNormal);
4416 testcase( !isTrue && bNormal);
4417 sqlite3VdbeAddOp4Int(v, OP_IsTrue, r1, inReg, !isTrue, isTrue ^ bNormal);
4418 break;
4419 }
4420 case TK_ISNULL:
4421 case TK_NOTNULL: {
4422 int addr;
4423 assert( TK_ISNULL==OP_IsNull ); testcase( op==TK_ISNULL );
4424 assert( TK_NOTNULL==OP_NotNull ); testcase( op==TK_NOTNULL );
4425 sqlite3VdbeAddOp2(v, OP_Integer, 1, target);
4426 r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, &regFree1);
4427 testcase( regFree1==0 );
4428 addr = sqlite3VdbeAddOp1(v, op, r1);
4429 VdbeCoverageIf(v, op==TK_ISNULL);
4430 VdbeCoverageIf(v, op==TK_NOTNULL);
4431 sqlite3VdbeAddOp2(v, OP_Integer, 0, target);
4432 sqlite3VdbeJumpHere(v, addr);
4433 break;
4434 }
4435 case TK_AGG_FUNCTION: {
4436 AggInfo *pInfo = pExpr->pAggInfo;
4437 if( pInfo==0
4438 || NEVER(pExpr->iAgg<0)
4439 || NEVER(pExpr->iAgg>=pInfo->nFunc)
4440 ){
4441 assert( !ExprHasProperty(pExpr, EP_IntValue) );
4442 sqlite3ErrorMsg(pParse, "misuse of aggregate: %#T()", pExpr);
4443 }else{
4444 return pInfo->aFunc[pExpr->iAgg].iMem;
4445 }
4446 break;
4447 }
4448 case TK_FUNCTION: {
4449 ExprList *pFarg; /* List of function arguments */
4450 int nFarg; /* Number of function arguments */
4451 FuncDef *pDef; /* The function definition object */
4452 const char *zId; /* The function name */
4453 u32 constMask = 0; /* Mask of function arguments that are constant */
4454 int i; /* Loop counter */
4455 sqlite3 *db = pParse->db; /* The database connection */
4456 u8 enc = ENC(db); /* The text encoding used by this database */
4457 CollSeq *pColl = 0; /* A collating sequence */
4458
4459#ifndef SQLITE_OMIT_WINDOWFUNC
4460 if( ExprHasProperty(pExpr, EP_WinFunc) ){
4461 return pExpr->y.pWin->regResult;
4462 }
4463#endif
4464
4465 if( ConstFactorOk(pParse) && sqlite3ExprIsConstantNotJoin(pExpr) ){
4466 /* SQL functions can be expensive. So try to avoid running them
4467 ** multiple times if we know they always give the same result */
4468 return sqlite3ExprCodeRunJustOnce(pParse, pExpr, -1);
4469 }
4470 assert( !ExprHasProperty(pExpr, EP_TokenOnly) );
4471 assert( ExprUseXList(pExpr) );
4472 pFarg = pExpr->x.pList;
4473 nFarg = pFarg ? pFarg->nExpr : 0;
4474 assert( !ExprHasProperty(pExpr, EP_IntValue) );
4475 zId = pExpr->u.zToken;
4476 pDef = sqlite3FindFunction(db, zId, nFarg, enc, 0);
4477#ifdef SQLITE_ENABLE_UNKNOWN_SQL_FUNCTION
4478 if( pDef==0 && pParse->explain ){
4479 pDef = sqlite3FindFunction(db, "unknown", nFarg, enc, 0);
4480 }
4481#endif
4482 if( pDef==0 || pDef->xFinalize!=0 ){
4483 sqlite3ErrorMsg(pParse, "unknown function: %#T()", pExpr);
4484 break;
4485 }
4486 if( pDef->funcFlags & SQLITE_FUNC_INLINE ){
4487 assert( (pDef->funcFlags & SQLITE_FUNC_UNSAFE)==0 );
4488 assert( (pDef->funcFlags & SQLITE_FUNC_DIRECT)==0 );
4489 return exprCodeInlineFunction(pParse, pFarg,
4490 SQLITE_PTR_TO_INT(pDef->pUserData), target);
4491 }else if( pDef->funcFlags & (SQLITE_FUNC_DIRECT|SQLITE_FUNC_UNSAFE) ){
4492 sqlite3ExprFunctionUsable(pParse, pExpr, pDef);
4493 }
4494
4495 for(i=0; i<nFarg; i++){
4496 if( i<32 && sqlite3ExprIsConstant(pFarg->a[i].pExpr) ){
4497 testcase( i==31 );
4498 constMask |= MASKBIT32(i);
4499 }
4500 if( (pDef->funcFlags & SQLITE_FUNC_NEEDCOLL)!=0 && !pColl ){
4501 pColl = sqlite3ExprCollSeq(pParse, pFarg->a[i].pExpr);
4502 }
4503 }
4504 if( pFarg ){
4505 if( constMask ){
4506 r1 = pParse->nMem+1;
4507 pParse->nMem += nFarg;
4508 }else{
4509 r1 = sqlite3GetTempRange(pParse, nFarg);
4510 }
4511
4512 /* For length() and typeof() functions with a column argument,
4513 ** set the P5 parameter to the OP_Column opcode to OPFLAG_LENGTHARG
4514 ** or OPFLAG_TYPEOFARG respectively, to avoid unnecessary data
4515 ** loading.
4516 */
4517 if( (pDef->funcFlags & (SQLITE_FUNC_LENGTH|SQLITE_FUNC_TYPEOF))!=0 ){
4518 u8 exprOp;
4519 assert( nFarg==1 );
4520 assert( pFarg->a[0].pExpr!=0 );
4521 exprOp = pFarg->a[0].pExpr->op;
4522 if( exprOp==TK_COLUMN || exprOp==TK_AGG_COLUMN ){
4523 assert( SQLITE_FUNC_LENGTH==OPFLAG_LENGTHARG );
4524 assert( SQLITE_FUNC_TYPEOF==OPFLAG_TYPEOFARG );
4525 testcase( pDef->funcFlags & OPFLAG_LENGTHARG );
4526 pFarg->a[0].pExpr->op2 =
4527 pDef->funcFlags & (OPFLAG_LENGTHARG|OPFLAG_TYPEOFARG);
4528 }
4529 }
4530
4531 sqlite3ExprCodeExprList(pParse, pFarg, r1, 0,
4532 SQLITE_ECEL_DUP|SQLITE_ECEL_FACTOR);
4533 }else{
4534 r1 = 0;
4535 }
4536#ifndef SQLITE_OMIT_VIRTUALTABLE
4537 /* Possibly overload the function if the first argument is
4538 ** a virtual table column.
4539 **
4540 ** For infix functions (LIKE, GLOB, REGEXP, and MATCH) use the
4541 ** second argument, not the first, as the argument to test to
4542 ** see if it is a column in a virtual table. This is done because
4543 ** the left operand of infix functions (the operand we want to
4544 ** control overloading) ends up as the second argument to the
4545 ** function. The expression "A glob B" is equivalent to
4546 ** "glob(B,A). We want to use the A in "A glob B" to test
4547 ** for function overloading. But we use the B term in "glob(B,A)".
4548 */
4549 if( nFarg>=2 && ExprHasProperty(pExpr, EP_InfixFunc) ){
4550 pDef = sqlite3VtabOverloadFunction(db, pDef, nFarg, pFarg->a[1].pExpr);
4551 }else if( nFarg>0 ){
4552 pDef = sqlite3VtabOverloadFunction(db, pDef, nFarg, pFarg->a[0].pExpr);
4553 }
4554#endif
4555 if( pDef->funcFlags & SQLITE_FUNC_NEEDCOLL ){
4556 if( !pColl ) pColl = db->pDfltColl;
4557 sqlite3VdbeAddOp4(v, OP_CollSeq, 0, 0, 0, (char *)pColl, P4_COLLSEQ);
4558 }
4559 sqlite3VdbeAddFunctionCall(pParse, constMask, r1, target, nFarg,
4560 pDef, pExpr->op2);
4561 if( nFarg ){
4562 if( constMask==0 ){
4563 sqlite3ReleaseTempRange(pParse, r1, nFarg);
4564 }else{
4565 sqlite3VdbeReleaseRegisters(pParse, r1, nFarg, constMask, 1);
4566 }
4567 }
4568 return target;
4569 }
4570#ifndef SQLITE_OMIT_SUBQUERY
4571 case TK_EXISTS:
4572 case TK_SELECT: {
4573 int nCol;
4574 testcase( op==TK_EXISTS );
4575 testcase( op==TK_SELECT );
4576 if( pParse->db->mallocFailed ){
4577 return 0;
4578 }else if( op==TK_SELECT
4579 && ALWAYS( ExprUseXSelect(pExpr) )
4580 && (nCol = pExpr->x.pSelect->pEList->nExpr)!=1
4581 ){
4582 sqlite3SubselectError(pParse, nCol, 1);
4583 }else{
4584 return sqlite3CodeSubselect(pParse, pExpr);
4585 }
4586 break;
4587 }
4588 case TK_SELECT_COLUMN: {
4589 int n;
4590 Expr *pLeft = pExpr->pLeft;
4591 if( pLeft->iTable==0 || pParse->withinRJSubrtn > pLeft->op2 ){
4592 pLeft->iTable = sqlite3CodeSubselect(pParse, pLeft);
4593 pLeft->op2 = pParse->withinRJSubrtn;
4594 }
4595 assert( pLeft->op==TK_SELECT || pLeft->op==TK_ERROR );
4596 n = sqlite3ExprVectorSize(pLeft);
4597 if( pExpr->iTable!=n ){
4598 sqlite3ErrorMsg(pParse, "%d columns assigned %d values",
4599 pExpr->iTable, n);
4600 }
4601 return pLeft->iTable + pExpr->iColumn;
4602 }
4603 case TK_IN: {
4604 int destIfFalse = sqlite3VdbeMakeLabel(pParse);
4605 int destIfNull = sqlite3VdbeMakeLabel(pParse);
4606 sqlite3VdbeAddOp2(v, OP_Null, 0, target);
4607 sqlite3ExprCodeIN(pParse, pExpr, destIfFalse, destIfNull);
4608 sqlite3VdbeAddOp2(v, OP_Integer, 1, target);
4609 sqlite3VdbeResolveLabel(v, destIfFalse);
4610 sqlite3VdbeAddOp2(v, OP_AddImm, target, 0);
4611 sqlite3VdbeResolveLabel(v, destIfNull);
4612 return target;
4613 }
4614#endif /* SQLITE_OMIT_SUBQUERY */
4615
4616
4617 /*
4618 ** x BETWEEN y AND z
4619 **
4620 ** This is equivalent to
4621 **
4622 ** x>=y AND x<=z
4623 **
4624 ** X is stored in pExpr->pLeft.
4625 ** Y is stored in pExpr->pList->a[0].pExpr.
4626 ** Z is stored in pExpr->pList->a[1].pExpr.
4627 */
4628 case TK_BETWEEN: {
4629 exprCodeBetween(pParse, pExpr, target, 0, 0);
4630 return target;
4631 }
4632 case TK_COLLATE: {
4633 if( !ExprHasProperty(pExpr, EP_Collate)
4634 && ALWAYS(pExpr->pLeft)
4635 && pExpr->pLeft->op==TK_FUNCTION
4636 ){
4637 inReg = sqlite3ExprCodeTarget(pParse, pExpr->pLeft, target);
4638 if( inReg!=target ){
4639 sqlite3VdbeAddOp2(v, OP_SCopy, inReg, target);
4640 inReg = target;
4641 }
4642 sqlite3VdbeAddOp1(v, OP_ClrSubtype, inReg);
4643 return inReg;
4644 }else{
4645 pExpr = pExpr->pLeft;
4646 goto expr_code_doover; /* 2018-04-28: Prevent deep recursion. */
4647 }
4648 }
4649 case TK_SPAN:
4650 case TK_UPLUS: {
4651 pExpr = pExpr->pLeft;
4652 goto expr_code_doover; /* 2018-04-28: Prevent deep recursion. OSSFuzz. */
4653 }
4654
4655 case TK_TRIGGER: {
4656 /* If the opcode is TK_TRIGGER, then the expression is a reference
4657 ** to a column in the new.* or old.* pseudo-tables available to
4658 ** trigger programs. In this case Expr.iTable is set to 1 for the
4659 ** new.* pseudo-table, or 0 for the old.* pseudo-table. Expr.iColumn
4660 ** is set to the column of the pseudo-table to read, or to -1 to
4661 ** read the rowid field.
4662 **
4663 ** The expression is implemented using an OP_Param opcode. The p1
4664 ** parameter is set to 0 for an old.rowid reference, or to (i+1)
4665 ** to reference another column of the old.* pseudo-table, where
4666 ** i is the index of the column. For a new.rowid reference, p1 is
4667 ** set to (n+1), where n is the number of columns in each pseudo-table.
4668 ** For a reference to any other column in the new.* pseudo-table, p1
4669 ** is set to (n+2+i), where n and i are as defined previously. For
4670 ** example, if the table on which triggers are being fired is
4671 ** declared as:
4672 **
4673 ** CREATE TABLE t1(a, b);
4674 **
4675 ** Then p1 is interpreted as follows:
4676 **
4677 ** p1==0 -> old.rowid p1==3 -> new.rowid
4678 ** p1==1 -> old.a p1==4 -> new.a
4679 ** p1==2 -> old.b p1==5 -> new.b
4680 */
4681 Table *pTab;
4682 int iCol;
4683 int p1;
4684
4685 assert( ExprUseYTab(pExpr) );
4686 pTab = pExpr->y.pTab;
4687 iCol = pExpr->iColumn;
4688 p1 = pExpr->iTable * (pTab->nCol+1) + 1
4689 + sqlite3TableColumnToStorage(pTab, iCol);
4690
4691 assert( pExpr->iTable==0 || pExpr->iTable==1 );
4692 assert( iCol>=-1 && iCol<pTab->nCol );
4693 assert( pTab->iPKey<0 || iCol!=pTab->iPKey );
4694 assert( p1>=0 && p1<(pTab->nCol*2+2) );
4695
4696 sqlite3VdbeAddOp2(v, OP_Param, p1, target);
4697 VdbeComment((v, "r[%d]=%s.%s", target,
4698 (pExpr->iTable ? "new" : "old"),
4699 (pExpr->iColumn<0 ? "rowid" : pExpr->y.pTab->aCol[iCol].zCnName)
4700 ));
4701
4702#ifndef SQLITE_OMIT_FLOATING_POINT
4703 /* If the column has REAL affinity, it may currently be stored as an
4704 ** integer. Use OP_RealAffinity to make sure it is really real.
4705 **
4706 ** EVIDENCE-OF: R-60985-57662 SQLite will convert the value back to
4707 ** floating point when extracting it from the record. */
4708 if( iCol>=0 && pTab->aCol[iCol].affinity==SQLITE_AFF_REAL ){
4709 sqlite3VdbeAddOp1(v, OP_RealAffinity, target);
4710 }
4711#endif
4712 break;
4713 }
4714
4715 case TK_VECTOR: {
4716 sqlite3ErrorMsg(pParse, "row value misused");
4717 break;
4718 }
4719
4720 /* TK_IF_NULL_ROW Expr nodes are inserted ahead of expressions
4721 ** that derive from the right-hand table of a LEFT JOIN. The
4722 ** Expr.iTable value is the table number for the right-hand table.
4723 ** The expression is only evaluated if that table is not currently
4724 ** on a LEFT JOIN NULL row.
4725 */
4726 case TK_IF_NULL_ROW: {
4727 int addrINR;
4728 u8 okConstFactor = pParse->okConstFactor;
4729 AggInfo *pAggInfo = pExpr->pAggInfo;
4730 if( pAggInfo ){
4731 assert( pExpr->iAgg>=0 && pExpr->iAgg<pAggInfo->nColumn );
4732 if( !pAggInfo->directMode ){
4733 inReg = pAggInfo->aCol[pExpr->iAgg].iMem;
4734 break;
4735 }
4736 if( pExpr->pAggInfo->useSortingIdx ){
4737 sqlite3VdbeAddOp3(v, OP_Column, pAggInfo->sortingIdxPTab,
4738 pAggInfo->aCol[pExpr->iAgg].iSorterColumn,
4739 target);
4740 inReg = target;
4741 break;
4742 }
4743 }
4744 addrINR = sqlite3VdbeAddOp1(v, OP_IfNullRow, pExpr->iTable);
4745 /* Temporarily disable factoring of constant expressions, since
4746 ** even though expressions may appear to be constant, they are not
4747 ** really constant because they originate from the right-hand side
4748 ** of a LEFT JOIN. */
4749 pParse->okConstFactor = 0;
4750 inReg = sqlite3ExprCodeTarget(pParse, pExpr->pLeft, target);
4751 pParse->okConstFactor = okConstFactor;
4752 sqlite3VdbeJumpHere(v, addrINR);
4753 sqlite3VdbeChangeP3(v, addrINR, inReg);
4754 break;
4755 }
4756
4757 /*
4758 ** Form A:
4759 ** CASE x WHEN e1 THEN r1 WHEN e2 THEN r2 ... WHEN eN THEN rN ELSE y END
4760 **
4761 ** Form B:
4762 ** CASE WHEN e1 THEN r1 WHEN e2 THEN r2 ... WHEN eN THEN rN ELSE y END
4763 **
4764 ** Form A is can be transformed into the equivalent form B as follows:
4765 ** CASE WHEN x=e1 THEN r1 WHEN x=e2 THEN r2 ...
4766 ** WHEN x=eN THEN rN ELSE y END
4767 **
4768 ** X (if it exists) is in pExpr->pLeft.
4769 ** Y is in the last element of pExpr->x.pList if pExpr->x.pList->nExpr is
4770 ** odd. The Y is also optional. If the number of elements in x.pList
4771 ** is even, then Y is omitted and the "otherwise" result is NULL.
4772 ** Ei is in pExpr->pList->a[i*2] and Ri is pExpr->pList->a[i*2+1].
4773 **
4774 ** The result of the expression is the Ri for the first matching Ei,
4775 ** or if there is no matching Ei, the ELSE term Y, or if there is
4776 ** no ELSE term, NULL.
4777 */
4778 case TK_CASE: {
4779 int endLabel; /* GOTO label for end of CASE stmt */
4780 int nextCase; /* GOTO label for next WHEN clause */
4781 int nExpr; /* 2x number of WHEN terms */
4782 int i; /* Loop counter */
4783 ExprList *pEList; /* List of WHEN terms */
4784 struct ExprList_item *aListelem; /* Array of WHEN terms */
4785 Expr opCompare; /* The X==Ei expression */
4786 Expr *pX; /* The X expression */
4787 Expr *pTest = 0; /* X==Ei (form A) or just Ei (form B) */
4788 Expr *pDel = 0;
4789 sqlite3 *db = pParse->db;
4790
4791 assert( ExprUseXList(pExpr) && pExpr->x.pList!=0 );
4792 assert(pExpr->x.pList->nExpr > 0);
4793 pEList = pExpr->x.pList;
4794 aListelem = pEList->a;
4795 nExpr = pEList->nExpr;
4796 endLabel = sqlite3VdbeMakeLabel(pParse);
4797 if( (pX = pExpr->pLeft)!=0 ){
4798 pDel = sqlite3ExprDup(db, pX, 0);
4799 if( db->mallocFailed ){
4800 sqlite3ExprDelete(db, pDel);
4801 break;
4802 }
4803 testcase( pX->op==TK_COLUMN );
4804 exprToRegister(pDel, exprCodeVector(pParse, pDel, &regFree1));
4805 testcase( regFree1==0 );
4806 memset(&opCompare, 0, sizeof(opCompare));
4807 opCompare.op = TK_EQ;
4808 opCompare.pLeft = pDel;
4809 pTest = &opCompare;
4810 /* Ticket b351d95f9cd5ef17e9d9dbae18f5ca8611190001:
4811 ** The value in regFree1 might get SCopy-ed into the file result.
4812 ** So make sure that the regFree1 register is not reused for other
4813 ** purposes and possibly overwritten. */
4814 regFree1 = 0;
4815 }
4816 for(i=0; i<nExpr-1; i=i+2){
4817 if( pX ){
4818 assert( pTest!=0 );
4819 opCompare.pRight = aListelem[i].pExpr;
4820 }else{
4821 pTest = aListelem[i].pExpr;
4822 }
4823 nextCase = sqlite3VdbeMakeLabel(pParse);
4824 testcase( pTest->op==TK_COLUMN );
4825 sqlite3ExprIfFalse(pParse, pTest, nextCase, SQLITE_JUMPIFNULL);
4826 testcase( aListelem[i+1].pExpr->op==TK_COLUMN );
4827 sqlite3ExprCode(pParse, aListelem[i+1].pExpr, target);
4828 sqlite3VdbeGoto(v, endLabel);
4829 sqlite3VdbeResolveLabel(v, nextCase);
4830 }
4831 if( (nExpr&1)!=0 ){
4832 sqlite3ExprCode(pParse, pEList->a[nExpr-1].pExpr, target);
4833 }else{
4834 sqlite3VdbeAddOp2(v, OP_Null, 0, target);
4835 }
4836 sqlite3ExprDelete(db, pDel);
4837 setDoNotMergeFlagOnCopy(v);
4838 sqlite3VdbeResolveLabel(v, endLabel);
4839 break;
4840 }
4841#ifndef SQLITE_OMIT_TRIGGER
4842 case TK_RAISE: {
4843 assert( pExpr->affExpr==OE_Rollback
4844 || pExpr->affExpr==OE_Abort
4845 || pExpr->affExpr==OE_Fail
4846 || pExpr->affExpr==OE_Ignore
4847 );
4848 if( !pParse->pTriggerTab && !pParse->nested ){
4849 sqlite3ErrorMsg(pParse,
4850 "RAISE() may only be used within a trigger-program");
4851 return 0;
4852 }
4853 if( pExpr->affExpr==OE_Abort ){
4854 sqlite3MayAbort(pParse);
4855 }
4856 assert( !ExprHasProperty(pExpr, EP_IntValue) );
4857 if( pExpr->affExpr==OE_Ignore ){
4858 sqlite3VdbeAddOp4(
4859 v, OP_Halt, SQLITE_OK, OE_Ignore, 0, pExpr->u.zToken,0);
4860 VdbeCoverage(v);
4861 }else{
4862 sqlite3HaltConstraint(pParse,
4863 pParse->pTriggerTab ? SQLITE_CONSTRAINT_TRIGGER : SQLITE_ERROR,
4864 pExpr->affExpr, pExpr->u.zToken, 0, 0);
4865 }
4866
4867 break;
4868 }
4869#endif
4870 }
4871 sqlite3ReleaseTempReg(pParse, regFree1);
4872 sqlite3ReleaseTempReg(pParse, regFree2);
4873 return inReg;
4874}
4875
4876/*
4877** Generate code that will evaluate expression pExpr just one time
4878** per prepared statement execution.
4879**
4880** If the expression uses functions (that might throw an exception) then
4881** guard them with an OP_Once opcode to ensure that the code is only executed
4882** once. If no functions are involved, then factor the code out and put it at
4883** the end of the prepared statement in the initialization section.
4884**
4885** If regDest>=0 then the result is always stored in that register and the
4886** result is not reusable. If regDest<0 then this routine is free to
4887** store the value whereever it wants. The register where the expression
4888** is stored is returned. When regDest<0, two identical expressions might
4889** code to the same register, if they do not contain function calls and hence
4890** are factored out into the initialization section at the end of the
4891** prepared statement.
4892*/
4893int sqlite3ExprCodeRunJustOnce(
4894 Parse *pParse, /* Parsing context */
4895 Expr *pExpr, /* The expression to code when the VDBE initializes */
4896 int regDest /* Store the value in this register */
4897){
4898 ExprList *p;
4899 assert( ConstFactorOk(pParse) );
4900 p = pParse->pConstExpr;
4901 if( regDest<0 && p ){
4902 struct ExprList_item *pItem;
4903 int i;
4904 for(pItem=p->a, i=p->nExpr; i>0; pItem++, i--){
4905 if( pItem->fg.reusable
4906 && sqlite3ExprCompare(0,pItem->pExpr,pExpr,-1)==0
4907 ){
4908 return pItem->u.iConstExprReg;
4909 }
4910 }
4911 }
4912 pExpr = sqlite3ExprDup(pParse->db, pExpr, 0);
4913 if( pExpr!=0 && ExprHasProperty(pExpr, EP_HasFunc) ){
4914 Vdbe *v = pParse->pVdbe;
4915 int addr;
4916 assert( v );
4917 addr = sqlite3VdbeAddOp0(v, OP_Once); VdbeCoverage(v);
4918 pParse->okConstFactor = 0;
4919 if( !pParse->db->mallocFailed ){
4920 if( regDest<0 ) regDest = ++pParse->nMem;
4921 sqlite3ExprCode(pParse, pExpr, regDest);
4922 }
4923 pParse->okConstFactor = 1;
4924 sqlite3ExprDelete(pParse->db, pExpr);
4925 sqlite3VdbeJumpHere(v, addr);
4926 }else{
4927 p = sqlite3ExprListAppend(pParse, p, pExpr);
4928 if( p ){
4929 struct ExprList_item *pItem = &p->a[p->nExpr-1];
4930 pItem->fg.reusable = regDest<0;
4931 if( regDest<0 ) regDest = ++pParse->nMem;
4932 pItem->u.iConstExprReg = regDest;
4933 }
4934 pParse->pConstExpr = p;
4935 }
4936 return regDest;
4937}
4938
4939/*
4940** Generate code to evaluate an expression and store the results
4941** into a register. Return the register number where the results
4942** are stored.
4943**
4944** If the register is a temporary register that can be deallocated,
4945** then write its number into *pReg. If the result register is not
4946** a temporary, then set *pReg to zero.
4947**
4948** If pExpr is a constant, then this routine might generate this
4949** code to fill the register in the initialization section of the
4950** VDBE program, in order to factor it out of the evaluation loop.
4951*/
4952int sqlite3ExprCodeTemp(Parse *pParse, Expr *pExpr, int *pReg){
4953 int r2;
4954 pExpr = sqlite3ExprSkipCollateAndLikely(pExpr);
4955 if( ConstFactorOk(pParse)
4956 && ALWAYS(pExpr!=0)
4957 && pExpr->op!=TK_REGISTER
4958 && sqlite3ExprIsConstantNotJoin(pExpr)
4959 ){
4960 *pReg = 0;
4961 r2 = sqlite3ExprCodeRunJustOnce(pParse, pExpr, -1);
4962 }else{
4963 int r1 = sqlite3GetTempReg(pParse);
4964 r2 = sqlite3ExprCodeTarget(pParse, pExpr, r1);
4965 if( r2==r1 ){
4966 *pReg = r1;
4967 }else{
4968 sqlite3ReleaseTempReg(pParse, r1);
4969 *pReg = 0;
4970 }
4971 }
4972 return r2;
4973}
4974
4975/*
4976** Generate code that will evaluate expression pExpr and store the
4977** results in register target. The results are guaranteed to appear
4978** in register target.
4979*/
4980void sqlite3ExprCode(Parse *pParse, Expr *pExpr, int target){
4981 int inReg;
4982
4983 assert( pExpr==0 || !ExprHasVVAProperty(pExpr,EP_Immutable) );
4984 assert( target>0 && target<=pParse->nMem );
4985 assert( pParse->pVdbe!=0 || pParse->db->mallocFailed );
4986 if( pParse->pVdbe==0 ) return;
4987 inReg = sqlite3ExprCodeTarget(pParse, pExpr, target);
4988 if( inReg!=target ){
4989 u8 op;
4990 if( ALWAYS(pExpr) && ExprHasProperty(pExpr,EP_Subquery) ){
4991 op = OP_Copy;
4992 }else{
4993 op = OP_SCopy;
4994 }
4995 sqlite3VdbeAddOp2(pParse->pVdbe, op, inReg, target);
4996 }
4997}
4998
4999/*
5000** Make a transient copy of expression pExpr and then code it using
5001** sqlite3ExprCode(). This routine works just like sqlite3ExprCode()
5002** except that the input expression is guaranteed to be unchanged.
5003*/
5004void sqlite3ExprCodeCopy(Parse *pParse, Expr *pExpr, int target){
5005 sqlite3 *db = pParse->db;
5006 pExpr = sqlite3ExprDup(db, pExpr, 0);
5007 if( !db->mallocFailed ) sqlite3ExprCode(pParse, pExpr, target);
5008 sqlite3ExprDelete(db, pExpr);
5009}
5010
5011/*
5012** Generate code that will evaluate expression pExpr and store the
5013** results in register target. The results are guaranteed to appear
5014** in register target. If the expression is constant, then this routine
5015** might choose to code the expression at initialization time.
5016*/
5017void sqlite3ExprCodeFactorable(Parse *pParse, Expr *pExpr, int target){
5018 if( pParse->okConstFactor && sqlite3ExprIsConstantNotJoin(pExpr) ){
5019 sqlite3ExprCodeRunJustOnce(pParse, pExpr, target);
5020 }else{
5021 sqlite3ExprCodeCopy(pParse, pExpr, target);
5022 }
5023}
5024
5025/*
5026** Generate code that pushes the value of every element of the given
5027** expression list into a sequence of registers beginning at target.
5028**
5029** Return the number of elements evaluated. The number returned will
5030** usually be pList->nExpr but might be reduced if SQLITE_ECEL_OMITREF
5031** is defined.
5032**
5033** The SQLITE_ECEL_DUP flag prevents the arguments from being
5034** filled using OP_SCopy. OP_Copy must be used instead.
5035**
5036** The SQLITE_ECEL_FACTOR argument allows constant arguments to be
5037** factored out into initialization code.
5038**
5039** The SQLITE_ECEL_REF flag means that expressions in the list with
5040** ExprList.a[].u.x.iOrderByCol>0 have already been evaluated and stored
5041** in registers at srcReg, and so the value can be copied from there.
5042** If SQLITE_ECEL_OMITREF is also set, then the values with u.x.iOrderByCol>0
5043** are simply omitted rather than being copied from srcReg.
5044*/
5045int sqlite3ExprCodeExprList(
5046 Parse *pParse, /* Parsing context */
5047 ExprList *pList, /* The expression list to be coded */
5048 int target, /* Where to write results */
5049 int srcReg, /* Source registers if SQLITE_ECEL_REF */
5050 u8 flags /* SQLITE_ECEL_* flags */
5051){
5052 struct ExprList_item *pItem;
5053 int i, j, n;
5054 u8 copyOp = (flags & SQLITE_ECEL_DUP) ? OP_Copy : OP_SCopy;
5055 Vdbe *v = pParse->pVdbe;
5056 assert( pList!=0 );
5057 assert( target>0 );
5058 assert( pParse->pVdbe!=0 ); /* Never gets this far otherwise */
5059 n = pList->nExpr;
5060 if( !ConstFactorOk(pParse) ) flags &= ~SQLITE_ECEL_FACTOR;
5061 for(pItem=pList->a, i=0; i<n; i++, pItem++){
5062 Expr *pExpr = pItem->pExpr;
5063#ifdef SQLITE_ENABLE_SORTER_REFERENCES
5064 if( pItem->fg.bSorterRef ){
5065 i--;
5066 n--;
5067 }else
5068#endif
5069 if( (flags & SQLITE_ECEL_REF)!=0 && (j = pItem->u.x.iOrderByCol)>0 ){
5070 if( flags & SQLITE_ECEL_OMITREF ){
5071 i--;
5072 n--;
5073 }else{
5074 sqlite3VdbeAddOp2(v, copyOp, j+srcReg-1, target+i);
5075 }
5076 }else if( (flags & SQLITE_ECEL_FACTOR)!=0
5077 && sqlite3ExprIsConstantNotJoin(pExpr)
5078 ){
5079 sqlite3ExprCodeRunJustOnce(pParse, pExpr, target+i);
5080 }else{
5081 int inReg = sqlite3ExprCodeTarget(pParse, pExpr, target+i);
5082 if( inReg!=target+i ){
5083 VdbeOp *pOp;
5084 if( copyOp==OP_Copy
5085 && (pOp=sqlite3VdbeGetLastOp(v))->opcode==OP_Copy
5086 && pOp->p1+pOp->p3+1==inReg
5087 && pOp->p2+pOp->p3+1==target+i
5088 && pOp->p5==0 /* The do-not-merge flag must be clear */
5089 ){
5090 pOp->p3++;
5091 }else{
5092 sqlite3VdbeAddOp2(v, copyOp, inReg, target+i);
5093 }
5094 }
5095 }
5096 }
5097 return n;
5098}
5099
5100/*
5101** Generate code for a BETWEEN operator.
5102**
5103** x BETWEEN y AND z
5104**
5105** The above is equivalent to
5106**
5107** x>=y AND x<=z
5108**
5109** Code it as such, taking care to do the common subexpression
5110** elimination of x.
5111**
5112** The xJumpIf parameter determines details:
5113**
5114** NULL: Store the boolean result in reg[dest]
5115** sqlite3ExprIfTrue: Jump to dest if true
5116** sqlite3ExprIfFalse: Jump to dest if false
5117**
5118** The jumpIfNull parameter is ignored if xJumpIf is NULL.
5119*/
5120static void exprCodeBetween(
5121 Parse *pParse, /* Parsing and code generating context */
5122 Expr *pExpr, /* The BETWEEN expression */
5123 int dest, /* Jump destination or storage location */
5124 void (*xJump)(Parse*,Expr*,int,int), /* Action to take */
5125 int jumpIfNull /* Take the jump if the BETWEEN is NULL */
5126){
5127 Expr exprAnd; /* The AND operator in x>=y AND x<=z */
5128 Expr compLeft; /* The x>=y term */
5129 Expr compRight; /* The x<=z term */
5130 int regFree1 = 0; /* Temporary use register */
5131 Expr *pDel = 0;
5132 sqlite3 *db = pParse->db;
5133
5134 memset(&compLeft, 0, sizeof(Expr));
5135 memset(&compRight, 0, sizeof(Expr));
5136 memset(&exprAnd, 0, sizeof(Expr));
5137
5138 assert( ExprUseXList(pExpr) );
5139 pDel = sqlite3ExprDup(db, pExpr->pLeft, 0);
5140 if( db->mallocFailed==0 ){
5141 exprAnd.op = TK_AND;
5142 exprAnd.pLeft = &compLeft;
5143 exprAnd.pRight = &compRight;
5144 compLeft.op = TK_GE;
5145 compLeft.pLeft = pDel;
5146 compLeft.pRight = pExpr->x.pList->a[0].pExpr;
5147 compRight.op = TK_LE;
5148 compRight.pLeft = pDel;
5149 compRight.pRight = pExpr->x.pList->a[1].pExpr;
5150 exprToRegister(pDel, exprCodeVector(pParse, pDel, &regFree1));
5151 if( xJump ){
5152 xJump(pParse, &exprAnd, dest, jumpIfNull);
5153 }else{
5154 /* Mark the expression is being from the ON or USING clause of a join
5155 ** so that the sqlite3ExprCodeTarget() routine will not attempt to move
5156 ** it into the Parse.pConstExpr list. We should use a new bit for this,
5157 ** for clarity, but we are out of bits in the Expr.flags field so we
5158 ** have to reuse the EP_OuterON bit. Bummer. */
5159 pDel->flags |= EP_OuterON;
5160 sqlite3ExprCodeTarget(pParse, &exprAnd, dest);
5161 }
5162 sqlite3ReleaseTempReg(pParse, regFree1);
5163 }
5164 sqlite3ExprDelete(db, pDel);
5165
5166 /* Ensure adequate test coverage */
5167 testcase( xJump==sqlite3ExprIfTrue && jumpIfNull==0 && regFree1==0 );
5168 testcase( xJump==sqlite3ExprIfTrue && jumpIfNull==0 && regFree1!=0 );
5169 testcase( xJump==sqlite3ExprIfTrue && jumpIfNull!=0 && regFree1==0 );
5170 testcase( xJump==sqlite3ExprIfTrue && jumpIfNull!=0 && regFree1!=0 );
5171 testcase( xJump==sqlite3ExprIfFalse && jumpIfNull==0 && regFree1==0 );
5172 testcase( xJump==sqlite3ExprIfFalse && jumpIfNull==0 && regFree1!=0 );
5173 testcase( xJump==sqlite3ExprIfFalse && jumpIfNull!=0 && regFree1==0 );
5174 testcase( xJump==sqlite3ExprIfFalse && jumpIfNull!=0 && regFree1!=0 );
5175 testcase( xJump==0 );
5176}
5177
5178/*
5179** Generate code for a boolean expression such that a jump is made
5180** to the label "dest" if the expression is true but execution
5181** continues straight thru if the expression is false.
5182**
5183** If the expression evaluates to NULL (neither true nor false), then
5184** take the jump if the jumpIfNull flag is SQLITE_JUMPIFNULL.
5185**
5186** This code depends on the fact that certain token values (ex: TK_EQ)
5187** are the same as opcode values (ex: OP_Eq) that implement the corresponding
5188** operation. Special comments in vdbe.c and the mkopcodeh.awk script in
5189** the make process cause these values to align. Assert()s in the code
5190** below verify that the numbers are aligned correctly.
5191*/
5192void sqlite3ExprIfTrue(Parse *pParse, Expr *pExpr, int dest, int jumpIfNull){
5193 Vdbe *v = pParse->pVdbe;
5194 int op = 0;
5195 int regFree1 = 0;
5196 int regFree2 = 0;
5197 int r1, r2;
5198
5199 assert( jumpIfNull==SQLITE_JUMPIFNULL || jumpIfNull==0 );
5200 if( NEVER(v==0) ) return; /* Existence of VDBE checked by caller */
5201 if( NEVER(pExpr==0) ) return; /* No way this can happen */
5202 assert( !ExprHasVVAProperty(pExpr, EP_Immutable) );
5203 op = pExpr->op;
5204 switch( op ){
5205 case TK_AND:
5206 case TK_OR: {
5207 Expr *pAlt = sqlite3ExprSimplifiedAndOr(pExpr);
5208 if( pAlt!=pExpr ){
5209 sqlite3ExprIfTrue(pParse, pAlt, dest, jumpIfNull);
5210 }else if( op==TK_AND ){
5211 int d2 = sqlite3VdbeMakeLabel(pParse);
5212 testcase( jumpIfNull==0 );
5213 sqlite3ExprIfFalse(pParse, pExpr->pLeft, d2,
5214 jumpIfNull^SQLITE_JUMPIFNULL);
5215 sqlite3ExprIfTrue(pParse, pExpr->pRight, dest, jumpIfNull);
5216 sqlite3VdbeResolveLabel(v, d2);
5217 }else{
5218 testcase( jumpIfNull==0 );
5219 sqlite3ExprIfTrue(pParse, pExpr->pLeft, dest, jumpIfNull);
5220 sqlite3ExprIfTrue(pParse, pExpr->pRight, dest, jumpIfNull);
5221 }
5222 break;
5223 }
5224 case TK_NOT: {
5225 testcase( jumpIfNull==0 );
5226 sqlite3ExprIfFalse(pParse, pExpr->pLeft, dest, jumpIfNull);
5227 break;
5228 }
5229 case TK_TRUTH: {
5230 int isNot; /* IS NOT TRUE or IS NOT FALSE */
5231 int isTrue; /* IS TRUE or IS NOT TRUE */
5232 testcase( jumpIfNull==0 );
5233 isNot = pExpr->op2==TK_ISNOT;
5234 isTrue = sqlite3ExprTruthValue(pExpr->pRight);
5235 testcase( isTrue && isNot );
5236 testcase( !isTrue && isNot );
5237 if( isTrue ^ isNot ){
5238 sqlite3ExprIfTrue(pParse, pExpr->pLeft, dest,
5239 isNot ? SQLITE_JUMPIFNULL : 0);
5240 }else{
5241 sqlite3ExprIfFalse(pParse, pExpr->pLeft, dest,
5242 isNot ? SQLITE_JUMPIFNULL : 0);
5243 }
5244 break;
5245 }
5246 case TK_IS:
5247 case TK_ISNOT:
5248 testcase( op==TK_IS );
5249 testcase( op==TK_ISNOT );
5250 op = (op==TK_IS) ? TK_EQ : TK_NE;
5251 jumpIfNull = SQLITE_NULLEQ;
5252 /* no break */ deliberate_fall_through
5253 case TK_LT:
5254 case TK_LE:
5255 case TK_GT:
5256 case TK_GE:
5257 case TK_NE:
5258 case TK_EQ: {
5259 if( sqlite3ExprIsVector(pExpr->pLeft) ) goto default_expr;
5260 testcase( jumpIfNull==0 );
5261 r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, &regFree1);
5262 r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, &regFree2);
5263 codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op,
5264 r1, r2, dest, jumpIfNull, ExprHasProperty(pExpr,EP_Commuted));
5265 assert(TK_LT==OP_Lt); testcase(op==OP_Lt); VdbeCoverageIf(v,op==OP_Lt);
5266 assert(TK_LE==OP_Le); testcase(op==OP_Le); VdbeCoverageIf(v,op==OP_Le);
5267 assert(TK_GT==OP_Gt); testcase(op==OP_Gt); VdbeCoverageIf(v,op==OP_Gt);
5268 assert(TK_GE==OP_Ge); testcase(op==OP_Ge); VdbeCoverageIf(v,op==OP_Ge);
5269 assert(TK_EQ==OP_Eq); testcase(op==OP_Eq);
5270 VdbeCoverageIf(v, op==OP_Eq && jumpIfNull==SQLITE_NULLEQ);
5271 VdbeCoverageIf(v, op==OP_Eq && jumpIfNull!=SQLITE_NULLEQ);
5272 assert(TK_NE==OP_Ne); testcase(op==OP_Ne);
5273 VdbeCoverageIf(v, op==OP_Ne && jumpIfNull==SQLITE_NULLEQ);
5274 VdbeCoverageIf(v, op==OP_Ne && jumpIfNull!=SQLITE_NULLEQ);
5275 testcase( regFree1==0 );
5276 testcase( regFree2==0 );
5277 break;
5278 }
5279 case TK_ISNULL:
5280 case TK_NOTNULL: {
5281 assert( TK_ISNULL==OP_IsNull ); testcase( op==TK_ISNULL );
5282 assert( TK_NOTNULL==OP_NotNull ); testcase( op==TK_NOTNULL );
5283 r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, &regFree1);
5284 sqlite3VdbeTypeofColumn(v, r1);
5285 sqlite3VdbeAddOp2(v, op, r1, dest);
5286 VdbeCoverageIf(v, op==TK_ISNULL);
5287 VdbeCoverageIf(v, op==TK_NOTNULL);
5288 testcase( regFree1==0 );
5289 break;
5290 }
5291 case TK_BETWEEN: {
5292 testcase( jumpIfNull==0 );
5293 exprCodeBetween(pParse, pExpr, dest, sqlite3ExprIfTrue, jumpIfNull);
5294 break;
5295 }
5296#ifndef SQLITE_OMIT_SUBQUERY
5297 case TK_IN: {
5298 int destIfFalse = sqlite3VdbeMakeLabel(pParse);
5299 int destIfNull = jumpIfNull ? dest : destIfFalse;
5300 sqlite3ExprCodeIN(pParse, pExpr, destIfFalse, destIfNull);
5301 sqlite3VdbeGoto(v, dest);
5302 sqlite3VdbeResolveLabel(v, destIfFalse);
5303 break;
5304 }
5305#endif
5306 default: {
5307 default_expr:
5308 if( ExprAlwaysTrue(pExpr) ){
5309 sqlite3VdbeGoto(v, dest);
5310 }else if( ExprAlwaysFalse(pExpr) ){
5311 /* No-op */
5312 }else{
5313 r1 = sqlite3ExprCodeTemp(pParse, pExpr, &regFree1);
5314 sqlite3VdbeAddOp3(v, OP_If, r1, dest, jumpIfNull!=0);
5315 VdbeCoverage(v);
5316 testcase( regFree1==0 );
5317 testcase( jumpIfNull==0 );
5318 }
5319 break;
5320 }
5321 }
5322 sqlite3ReleaseTempReg(pParse, regFree1);
5323 sqlite3ReleaseTempReg(pParse, regFree2);
5324}
5325
5326/*
5327** Generate code for a boolean expression such that a jump is made
5328** to the label "dest" if the expression is false but execution
5329** continues straight thru if the expression is true.
5330**
5331** If the expression evaluates to NULL (neither true nor false) then
5332** jump if jumpIfNull is SQLITE_JUMPIFNULL or fall through if jumpIfNull
5333** is 0.
5334*/
5335void sqlite3ExprIfFalse(Parse *pParse, Expr *pExpr, int dest, int jumpIfNull){
5336 Vdbe *v = pParse->pVdbe;
5337 int op = 0;
5338 int regFree1 = 0;
5339 int regFree2 = 0;
5340 int r1, r2;
5341
5342 assert( jumpIfNull==SQLITE_JUMPIFNULL || jumpIfNull==0 );
5343 if( NEVER(v==0) ) return; /* Existence of VDBE checked by caller */
5344 if( pExpr==0 ) return;
5345 assert( !ExprHasVVAProperty(pExpr,EP_Immutable) );
5346
5347 /* The value of pExpr->op and op are related as follows:
5348 **
5349 ** pExpr->op op
5350 ** --------- ----------
5351 ** TK_ISNULL OP_NotNull
5352 ** TK_NOTNULL OP_IsNull
5353 ** TK_NE OP_Eq
5354 ** TK_EQ OP_Ne
5355 ** TK_GT OP_Le
5356 ** TK_LE OP_Gt
5357 ** TK_GE OP_Lt
5358 ** TK_LT OP_Ge
5359 **
5360 ** For other values of pExpr->op, op is undefined and unused.
5361 ** The value of TK_ and OP_ constants are arranged such that we
5362 ** can compute the mapping above using the following expression.
5363 ** Assert()s verify that the computation is correct.
5364 */
5365 op = ((pExpr->op+(TK_ISNULL&1))^1)-(TK_ISNULL&1);
5366
5367 /* Verify correct alignment of TK_ and OP_ constants
5368 */
5369 assert( pExpr->op!=TK_ISNULL || op==OP_NotNull );
5370 assert( pExpr->op!=TK_NOTNULL || op==OP_IsNull );
5371 assert( pExpr->op!=TK_NE || op==OP_Eq );
5372 assert( pExpr->op!=TK_EQ || op==OP_Ne );
5373 assert( pExpr->op!=TK_LT || op==OP_Ge );
5374 assert( pExpr->op!=TK_LE || op==OP_Gt );
5375 assert( pExpr->op!=TK_GT || op==OP_Le );
5376 assert( pExpr->op!=TK_GE || op==OP_Lt );
5377
5378 switch( pExpr->op ){
5379 case TK_AND:
5380 case TK_OR: {
5381 Expr *pAlt = sqlite3ExprSimplifiedAndOr(pExpr);
5382 if( pAlt!=pExpr ){
5383 sqlite3ExprIfFalse(pParse, pAlt, dest, jumpIfNull);
5384 }else if( pExpr->op==TK_AND ){
5385 testcase( jumpIfNull==0 );
5386 sqlite3ExprIfFalse(pParse, pExpr->pLeft, dest, jumpIfNull);
5387 sqlite3ExprIfFalse(pParse, pExpr->pRight, dest, jumpIfNull);
5388 }else{
5389 int d2 = sqlite3VdbeMakeLabel(pParse);
5390 testcase( jumpIfNull==0 );
5391 sqlite3ExprIfTrue(pParse, pExpr->pLeft, d2,
5392 jumpIfNull^SQLITE_JUMPIFNULL);
5393 sqlite3ExprIfFalse(pParse, pExpr->pRight, dest, jumpIfNull);
5394 sqlite3VdbeResolveLabel(v, d2);
5395 }
5396 break;
5397 }
5398 case TK_NOT: {
5399 testcase( jumpIfNull==0 );
5400 sqlite3ExprIfTrue(pParse, pExpr->pLeft, dest, jumpIfNull);
5401 break;
5402 }
5403 case TK_TRUTH: {
5404 int isNot; /* IS NOT TRUE or IS NOT FALSE */
5405 int isTrue; /* IS TRUE or IS NOT TRUE */
5406 testcase( jumpIfNull==0 );
5407 isNot = pExpr->op2==TK_ISNOT;
5408 isTrue = sqlite3ExprTruthValue(pExpr->pRight);
5409 testcase( isTrue && isNot );
5410 testcase( !isTrue && isNot );
5411 if( isTrue ^ isNot ){
5412 /* IS TRUE and IS NOT FALSE */
5413 sqlite3ExprIfFalse(pParse, pExpr->pLeft, dest,
5414 isNot ? 0 : SQLITE_JUMPIFNULL);
5415
5416 }else{
5417 /* IS FALSE and IS NOT TRUE */
5418 sqlite3ExprIfTrue(pParse, pExpr->pLeft, dest,
5419 isNot ? 0 : SQLITE_JUMPIFNULL);
5420 }
5421 break;
5422 }
5423 case TK_IS:
5424 case TK_ISNOT:
5425 testcase( pExpr->op==TK_IS );
5426 testcase( pExpr->op==TK_ISNOT );
5427 op = (pExpr->op==TK_IS) ? TK_NE : TK_EQ;
5428 jumpIfNull = SQLITE_NULLEQ;
5429 /* no break */ deliberate_fall_through
5430 case TK_LT:
5431 case TK_LE:
5432 case TK_GT:
5433 case TK_GE:
5434 case TK_NE:
5435 case TK_EQ: {
5436 if( sqlite3ExprIsVector(pExpr->pLeft) ) goto default_expr;
5437 testcase( jumpIfNull==0 );
5438 r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, &regFree1);
5439 r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, &regFree2);
5440 codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op,
5441 r1, r2, dest, jumpIfNull,ExprHasProperty(pExpr,EP_Commuted));
5442 assert(TK_LT==OP_Lt); testcase(op==OP_Lt); VdbeCoverageIf(v,op==OP_Lt);
5443 assert(TK_LE==OP_Le); testcase(op==OP_Le); VdbeCoverageIf(v,op==OP_Le);
5444 assert(TK_GT==OP_Gt); testcase(op==OP_Gt); VdbeCoverageIf(v,op==OP_Gt);
5445 assert(TK_GE==OP_Ge); testcase(op==OP_Ge); VdbeCoverageIf(v,op==OP_Ge);
5446 assert(TK_EQ==OP_Eq); testcase(op==OP_Eq);
5447 VdbeCoverageIf(v, op==OP_Eq && jumpIfNull!=SQLITE_NULLEQ);
5448 VdbeCoverageIf(v, op==OP_Eq && jumpIfNull==SQLITE_NULLEQ);
5449 assert(TK_NE==OP_Ne); testcase(op==OP_Ne);
5450 VdbeCoverageIf(v, op==OP_Ne && jumpIfNull!=SQLITE_NULLEQ);
5451 VdbeCoverageIf(v, op==OP_Ne && jumpIfNull==SQLITE_NULLEQ);
5452 testcase( regFree1==0 );
5453 testcase( regFree2==0 );
5454 break;
5455 }
5456 case TK_ISNULL:
5457 case TK_NOTNULL: {
5458 r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, &regFree1);
5459 sqlite3VdbeTypeofColumn(v, r1);
5460 sqlite3VdbeAddOp2(v, op, r1, dest);
5461 testcase( op==TK_ISNULL ); VdbeCoverageIf(v, op==TK_ISNULL);
5462 testcase( op==TK_NOTNULL ); VdbeCoverageIf(v, op==TK_NOTNULL);
5463 testcase( regFree1==0 );
5464 break;
5465 }
5466 case TK_BETWEEN: {
5467 testcase( jumpIfNull==0 );
5468 exprCodeBetween(pParse, pExpr, dest, sqlite3ExprIfFalse, jumpIfNull);
5469 break;
5470 }
5471#ifndef SQLITE_OMIT_SUBQUERY
5472 case TK_IN: {
5473 if( jumpIfNull ){
5474 sqlite3ExprCodeIN(pParse, pExpr, dest, dest);
5475 }else{
5476 int destIfNull = sqlite3VdbeMakeLabel(pParse);
5477 sqlite3ExprCodeIN(pParse, pExpr, dest, destIfNull);
5478 sqlite3VdbeResolveLabel(v, destIfNull);
5479 }
5480 break;
5481 }
5482#endif
5483 default: {
5484 default_expr:
5485 if( ExprAlwaysFalse(pExpr) ){
5486 sqlite3VdbeGoto(v, dest);
5487 }else if( ExprAlwaysTrue(pExpr) ){
5488 /* no-op */
5489 }else{
5490 r1 = sqlite3ExprCodeTemp(pParse, pExpr, &regFree1);
5491 sqlite3VdbeAddOp3(v, OP_IfNot, r1, dest, jumpIfNull!=0);
5492 VdbeCoverage(v);
5493 testcase( regFree1==0 );
5494 testcase( jumpIfNull==0 );
5495 }
5496 break;
5497 }
5498 }
5499 sqlite3ReleaseTempReg(pParse, regFree1);
5500 sqlite3ReleaseTempReg(pParse, regFree2);
5501}
5502
5503/*
5504** Like sqlite3ExprIfFalse() except that a copy is made of pExpr before
5505** code generation, and that copy is deleted after code generation. This
5506** ensures that the original pExpr is unchanged.
5507*/
5508void sqlite3ExprIfFalseDup(Parse *pParse, Expr *pExpr, int dest,int jumpIfNull){
5509 sqlite3 *db = pParse->db;
5510 Expr *pCopy = sqlite3ExprDup(db, pExpr, 0);
5511 if( db->mallocFailed==0 ){
5512 sqlite3ExprIfFalse(pParse, pCopy, dest, jumpIfNull);
5513 }
5514 sqlite3ExprDelete(db, pCopy);
5515}
5516
5517/*
5518** Expression pVar is guaranteed to be an SQL variable. pExpr may be any
5519** type of expression.
5520**
5521** If pExpr is a simple SQL value - an integer, real, string, blob
5522** or NULL value - then the VDBE currently being prepared is configured
5523** to re-prepare each time a new value is bound to variable pVar.
5524**
5525** Additionally, if pExpr is a simple SQL value and the value is the
5526** same as that currently bound to variable pVar, non-zero is returned.
5527** Otherwise, if the values are not the same or if pExpr is not a simple
5528** SQL value, zero is returned.
5529*/
5530static int exprCompareVariable(
5531 const Parse *pParse,
5532 const Expr *pVar,
5533 const Expr *pExpr
5534){
5535 int res = 0;
5536 int iVar;
5537 sqlite3_value *pL, *pR = 0;
5538
5539 sqlite3ValueFromExpr(pParse->db, pExpr, SQLITE_UTF8, SQLITE_AFF_BLOB, &pR);
5540 if( pR ){
5541 iVar = pVar->iColumn;
5542 sqlite3VdbeSetVarmask(pParse->pVdbe, iVar);
5543 pL = sqlite3VdbeGetBoundValue(pParse->pReprepare, iVar, SQLITE_AFF_BLOB);
5544 if( pL ){
5545 if( sqlite3_value_type(pL)==SQLITE_TEXT ){
5546 sqlite3_value_text(pL); /* Make sure the encoding is UTF-8 */
5547 }
5548 res = 0==sqlite3MemCompare(pL, pR, 0);
5549 }
5550 sqlite3ValueFree(pR);
5551 sqlite3ValueFree(pL);
5552 }
5553
5554 return res;
5555}
5556
5557/*
5558** Do a deep comparison of two expression trees. Return 0 if the two
5559** expressions are completely identical. Return 1 if they differ only
5560** by a COLLATE operator at the top level. Return 2 if there are differences
5561** other than the top-level COLLATE operator.
5562**
5563** If any subelement of pB has Expr.iTable==(-1) then it is allowed
5564** to compare equal to an equivalent element in pA with Expr.iTable==iTab.
5565**
5566** The pA side might be using TK_REGISTER. If that is the case and pB is
5567** not using TK_REGISTER but is otherwise equivalent, then still return 0.
5568**
5569** Sometimes this routine will return 2 even if the two expressions
5570** really are equivalent. If we cannot prove that the expressions are
5571** identical, we return 2 just to be safe. So if this routine
5572** returns 2, then you do not really know for certain if the two
5573** expressions are the same. But if you get a 0 or 1 return, then you
5574** can be sure the expressions are the same. In the places where
5575** this routine is used, it does not hurt to get an extra 2 - that
5576** just might result in some slightly slower code. But returning
5577** an incorrect 0 or 1 could lead to a malfunction.
5578**
5579** If pParse is not NULL then TK_VARIABLE terms in pA with bindings in
5580** pParse->pReprepare can be matched against literals in pB. The
5581** pParse->pVdbe->expmask bitmask is updated for each variable referenced.
5582** If pParse is NULL (the normal case) then any TK_VARIABLE term in
5583** Argument pParse should normally be NULL. If it is not NULL and pA or
5584** pB causes a return value of 2.
5585*/
5586int sqlite3ExprCompare(
5587 const Parse *pParse,
5588 const Expr *pA,
5589 const Expr *pB,
5590 int iTab
5591){
5592 u32 combinedFlags;
5593 if( pA==0 || pB==0 ){
5594 return pB==pA ? 0 : 2;
5595 }
5596 if( pParse && pA->op==TK_VARIABLE && exprCompareVariable(pParse, pA, pB) ){
5597 return 0;
5598 }
5599 combinedFlags = pA->flags | pB->flags;
5600 if( combinedFlags & EP_IntValue ){
5601 if( (pA->flags&pB->flags&EP_IntValue)!=0 && pA->u.iValue==pB->u.iValue ){
5602 return 0;
5603 }
5604 return 2;
5605 }
5606 if( pA->op!=pB->op || pA->op==TK_RAISE ){
5607 if( pA->op==TK_COLLATE && sqlite3ExprCompare(pParse, pA->pLeft,pB,iTab)<2 ){
5608 return 1;
5609 }
5610 if( pB->op==TK_COLLATE && sqlite3ExprCompare(pParse, pA,pB->pLeft,iTab)<2 ){
5611 return 1;
5612 }
5613 if( pA->op==TK_AGG_COLUMN && pB->op==TK_COLUMN
5614 && pB->iTable<0 && pA->iTable==iTab
5615 ){
5616 /* fall through */
5617 }else{
5618 return 2;
5619 }
5620 }
5621 assert( !ExprHasProperty(pA, EP_IntValue) );
5622 assert( !ExprHasProperty(pB, EP_IntValue) );
5623 if( pA->u.zToken ){
5624 if( pA->op==TK_FUNCTION || pA->op==TK_AGG_FUNCTION ){
5625 if( sqlite3StrICmp(pA->u.zToken,pB->u.zToken)!=0 ) return 2;
5626#ifndef SQLITE_OMIT_WINDOWFUNC
5627 assert( pA->op==pB->op );
5628 if( ExprHasProperty(pA,EP_WinFunc)!=ExprHasProperty(pB,EP_WinFunc) ){
5629 return 2;
5630 }
5631 if( ExprHasProperty(pA,EP_WinFunc) ){
5632 if( sqlite3WindowCompare(pParse, pA->y.pWin, pB->y.pWin, 1)!=0 ){
5633 return 2;
5634 }
5635 }
5636#endif
5637 }else if( pA->op==TK_NULL ){
5638 return 0;
5639 }else if( pA->op==TK_COLLATE ){
5640 if( sqlite3_stricmp(pA->u.zToken,pB->u.zToken)!=0 ) return 2;
5641 }else
5642 if( pB->u.zToken!=0
5643 && pA->op!=TK_COLUMN
5644 && pA->op!=TK_AGG_COLUMN
5645 && strcmp(pA->u.zToken,pB->u.zToken)!=0
5646 ){
5647 return 2;
5648 }
5649 }
5650 if( (pA->flags & (EP_Distinct|EP_Commuted))
5651 != (pB->flags & (EP_Distinct|EP_Commuted)) ) return 2;
5652 if( ALWAYS((combinedFlags & EP_TokenOnly)==0) ){
5653 if( combinedFlags & EP_xIsSelect ) return 2;
5654 if( (combinedFlags & EP_FixedCol)==0
5655 && sqlite3ExprCompare(pParse, pA->pLeft, pB->pLeft, iTab) ) return 2;
5656 if( sqlite3ExprCompare(pParse, pA->pRight, pB->pRight, iTab) ) return 2;
5657 if( sqlite3ExprListCompare(pA->x.pList, pB->x.pList, iTab) ) return 2;
5658 if( pA->op!=TK_STRING
5659 && pA->op!=TK_TRUEFALSE
5660 && ALWAYS((combinedFlags & EP_Reduced)==0)
5661 ){
5662 if( pA->iColumn!=pB->iColumn ) return 2;
5663 if( pA->op2!=pB->op2 && pA->op==TK_TRUTH ) return 2;
5664 if( pA->op!=TK_IN && pA->iTable!=pB->iTable && pA->iTable!=iTab ){
5665 return 2;
5666 }
5667 }
5668 }
5669 return 0;
5670}
5671
5672/*
5673** Compare two ExprList objects. Return 0 if they are identical, 1
5674** if they are certainly different, or 2 if it is not possible to
5675** determine if they are identical or not.
5676**
5677** If any subelement of pB has Expr.iTable==(-1) then it is allowed
5678** to compare equal to an equivalent element in pA with Expr.iTable==iTab.
5679**
5680** This routine might return non-zero for equivalent ExprLists. The
5681** only consequence will be disabled optimizations. But this routine
5682** must never return 0 if the two ExprList objects are different, or
5683** a malfunction will result.
5684**
5685** Two NULL pointers are considered to be the same. But a NULL pointer
5686** always differs from a non-NULL pointer.
5687*/
5688int sqlite3ExprListCompare(const ExprList *pA, const ExprList *pB, int iTab){
5689 int i;
5690 if( pA==0 && pB==0 ) return 0;
5691 if( pA==0 || pB==0 ) return 1;
5692 if( pA->nExpr!=pB->nExpr ) return 1;
5693 for(i=0; i<pA->nExpr; i++){
5694 int res;
5695 Expr *pExprA = pA->a[i].pExpr;
5696 Expr *pExprB = pB->a[i].pExpr;
5697 if( pA->a[i].fg.sortFlags!=pB->a[i].fg.sortFlags ) return 1;
5698 if( (res = sqlite3ExprCompare(0, pExprA, pExprB, iTab)) ) return res;
5699 }
5700 return 0;
5701}
5702
5703/*
5704** Like sqlite3ExprCompare() except COLLATE operators at the top-level
5705** are ignored.
5706*/
5707int sqlite3ExprCompareSkip(Expr *pA,Expr *pB, int iTab){
5708 return sqlite3ExprCompare(0,
5709 sqlite3ExprSkipCollateAndLikely(pA),
5710 sqlite3ExprSkipCollateAndLikely(pB),
5711 iTab);
5712}
5713
5714/*
5715** Return non-zero if Expr p can only be true if pNN is not NULL.
5716**
5717** Or if seenNot is true, return non-zero if Expr p can only be
5718** non-NULL if pNN is not NULL
5719*/
5720static int exprImpliesNotNull(
5721 const Parse *pParse,/* Parsing context */
5722 const Expr *p, /* The expression to be checked */
5723 const Expr *pNN, /* The expression that is NOT NULL */
5724 int iTab, /* Table being evaluated */
5725 int seenNot /* Return true only if p can be any non-NULL value */
5726){
5727 assert( p );
5728 assert( pNN );
5729 if( sqlite3ExprCompare(pParse, p, pNN, iTab)==0 ){
5730 return pNN->op!=TK_NULL;
5731 }
5732 switch( p->op ){
5733 case TK_IN: {
5734 if( seenNot && ExprHasProperty(p, EP_xIsSelect) ) return 0;
5735 assert( ExprUseXSelect(p) || (p->x.pList!=0 && p->x.pList->nExpr>0) );
5736 return exprImpliesNotNull(pParse, p->pLeft, pNN, iTab, 1);
5737 }
5738 case TK_BETWEEN: {
5739 ExprList *pList;
5740 assert( ExprUseXList(p) );
5741 pList = p->x.pList;
5742 assert( pList!=0 );
5743 assert( pList->nExpr==2 );
5744 if( seenNot ) return 0;
5745 if( exprImpliesNotNull(pParse, pList->a[0].pExpr, pNN, iTab, 1)
5746 || exprImpliesNotNull(pParse, pList->a[1].pExpr, pNN, iTab, 1)
5747 ){
5748 return 1;
5749 }
5750 return exprImpliesNotNull(pParse, p->pLeft, pNN, iTab, 1);
5751 }
5752 case TK_EQ:
5753 case TK_NE:
5754 case TK_LT:
5755 case TK_LE:
5756 case TK_GT:
5757 case TK_GE:
5758 case TK_PLUS:
5759 case TK_MINUS:
5760 case TK_BITOR:
5761 case TK_LSHIFT:
5762 case TK_RSHIFT:
5763 case TK_CONCAT:
5764 seenNot = 1;
5765 /* no break */ deliberate_fall_through
5766 case TK_STAR:
5767 case TK_REM:
5768 case TK_BITAND:
5769 case TK_SLASH: {
5770 if( exprImpliesNotNull(pParse, p->pRight, pNN, iTab, seenNot) ) return 1;
5771 /* no break */ deliberate_fall_through
5772 }
5773 case TK_SPAN:
5774 case TK_COLLATE:
5775 case TK_UPLUS:
5776 case TK_UMINUS: {
5777 return exprImpliesNotNull(pParse, p->pLeft, pNN, iTab, seenNot);
5778 }
5779 case TK_TRUTH: {
5780 if( seenNot ) return 0;
5781 if( p->op2!=TK_IS ) return 0;
5782 return exprImpliesNotNull(pParse, p->pLeft, pNN, iTab, 1);
5783 }
5784 case TK_BITNOT:
5785 case TK_NOT: {
5786 return exprImpliesNotNull(pParse, p->pLeft, pNN, iTab, 1);
5787 }
5788 }
5789 return 0;
5790}
5791
5792/*
5793** Return true if we can prove the pE2 will always be true if pE1 is
5794** true. Return false if we cannot complete the proof or if pE2 might
5795** be false. Examples:
5796**
5797** pE1: x==5 pE2: x==5 Result: true
5798** pE1: x>0 pE2: x==5 Result: false
5799** pE1: x=21 pE2: x=21 OR y=43 Result: true
5800** pE1: x!=123 pE2: x IS NOT NULL Result: true
5801** pE1: x!=?1 pE2: x IS NOT NULL Result: true
5802** pE1: x IS NULL pE2: x IS NOT NULL Result: false
5803** pE1: x IS ?2 pE2: x IS NOT NULL Reuslt: false
5804**
5805** When comparing TK_COLUMN nodes between pE1 and pE2, if pE2 has
5806** Expr.iTable<0 then assume a table number given by iTab.
5807**
5808** If pParse is not NULL, then the values of bound variables in pE1 are
5809** compared against literal values in pE2 and pParse->pVdbe->expmask is
5810** modified to record which bound variables are referenced. If pParse
5811** is NULL, then false will be returned if pE1 contains any bound variables.
5812**
5813** When in doubt, return false. Returning true might give a performance
5814** improvement. Returning false might cause a performance reduction, but
5815** it will always give the correct answer and is hence always safe.
5816*/
5817int sqlite3ExprImpliesExpr(
5818 const Parse *pParse,
5819 const Expr *pE1,
5820 const Expr *pE2,
5821 int iTab
5822){
5823 if( sqlite3ExprCompare(pParse, pE1, pE2, iTab)==0 ){
5824 return 1;
5825 }
5826 if( pE2->op==TK_OR
5827 && (sqlite3ExprImpliesExpr(pParse, pE1, pE2->pLeft, iTab)
5828 || sqlite3ExprImpliesExpr(pParse, pE1, pE2->pRight, iTab) )
5829 ){
5830 return 1;
5831 }
5832 if( pE2->op==TK_NOTNULL
5833 && exprImpliesNotNull(pParse, pE1, pE2->pLeft, iTab, 0)
5834 ){
5835 return 1;
5836 }
5837 return 0;
5838}
5839
5840/*
5841** This is the Expr node callback for sqlite3ExprImpliesNonNullRow().
5842** If the expression node requires that the table at pWalker->iCur
5843** have one or more non-NULL column, then set pWalker->eCode to 1 and abort.
5844**
5845** This routine controls an optimization. False positives (setting
5846** pWalker->eCode to 1 when it should not be) are deadly, but false-negatives
5847** (never setting pWalker->eCode) is a harmless missed optimization.
5848*/
5849static int impliesNotNullRow(Walker *pWalker, Expr *pExpr){
5850 testcase( pExpr->op==TK_AGG_COLUMN );
5851 testcase( pExpr->op==TK_AGG_FUNCTION );
5852 if( ExprHasProperty(pExpr, EP_OuterON) ) return WRC_Prune;
5853 switch( pExpr->op ){
5854 case TK_ISNOT:
5855 case TK_ISNULL:
5856 case TK_NOTNULL:
5857 case TK_IS:
5858 case TK_OR:
5859 case TK_VECTOR:
5860 case TK_CASE:
5861 case TK_IN:
5862 case TK_FUNCTION:
5863 case TK_TRUTH:
5864 testcase( pExpr->op==TK_ISNOT );
5865 testcase( pExpr->op==TK_ISNULL );
5866 testcase( pExpr->op==TK_NOTNULL );
5867 testcase( pExpr->op==TK_IS );
5868 testcase( pExpr->op==TK_OR );
5869 testcase( pExpr->op==TK_VECTOR );
5870 testcase( pExpr->op==TK_CASE );
5871 testcase( pExpr->op==TK_IN );
5872 testcase( pExpr->op==TK_FUNCTION );
5873 testcase( pExpr->op==TK_TRUTH );
5874 return WRC_Prune;
5875 case TK_COLUMN:
5876 if( pWalker->u.iCur==pExpr->iTable ){
5877 pWalker->eCode = 1;
5878 return WRC_Abort;
5879 }
5880 return WRC_Prune;
5881
5882 case TK_AND:
5883 if( pWalker->eCode==0 ){
5884 sqlite3WalkExpr(pWalker, pExpr->pLeft);
5885 if( pWalker->eCode ){
5886 pWalker->eCode = 0;
5887 sqlite3WalkExpr(pWalker, pExpr->pRight);
5888 }
5889 }
5890 return WRC_Prune;
5891
5892 case TK_BETWEEN:
5893 if( sqlite3WalkExpr(pWalker, pExpr->pLeft)==WRC_Abort ){
5894 assert( pWalker->eCode );
5895 return WRC_Abort;
5896 }
5897 return WRC_Prune;
5898
5899 /* Virtual tables are allowed to use constraints like x=NULL. So
5900 ** a term of the form x=y does not prove that y is not null if x
5901 ** is the column of a virtual table */
5902 case TK_EQ:
5903 case TK_NE:
5904 case TK_LT:
5905 case TK_LE:
5906 case TK_GT:
5907 case TK_GE: {
5908 Expr *pLeft = pExpr->pLeft;
5909 Expr *pRight = pExpr->pRight;
5910 testcase( pExpr->op==TK_EQ );
5911 testcase( pExpr->op==TK_NE );
5912 testcase( pExpr->op==TK_LT );
5913 testcase( pExpr->op==TK_LE );
5914 testcase( pExpr->op==TK_GT );
5915 testcase( pExpr->op==TK_GE );
5916 /* The y.pTab=0 assignment in wherecode.c always happens after the
5917 ** impliesNotNullRow() test */
5918 assert( pLeft->op!=TK_COLUMN || ExprUseYTab(pLeft) );
5919 assert( pRight->op!=TK_COLUMN || ExprUseYTab(pRight) );
5920 if( (pLeft->op==TK_COLUMN
5921 && ALWAYS(pLeft->y.pTab!=0)
5922 && IsVirtual(pLeft->y.pTab))
5923 || (pRight->op==TK_COLUMN
5924 && ALWAYS(pRight->y.pTab!=0)
5925 && IsVirtual(pRight->y.pTab))
5926 ){
5927 return WRC_Prune;
5928 }
5929 /* no break */ deliberate_fall_through
5930 }
5931 default:
5932 return WRC_Continue;
5933 }
5934}
5935
5936/*
5937** Return true (non-zero) if expression p can only be true if at least
5938** one column of table iTab is non-null. In other words, return true
5939** if expression p will always be NULL or false if every column of iTab
5940** is NULL.
5941**
5942** False negatives are acceptable. In other words, it is ok to return
5943** zero even if expression p will never be true of every column of iTab
5944** is NULL. A false negative is merely a missed optimization opportunity.
5945**
5946** False positives are not allowed, however. A false positive may result
5947** in an incorrect answer.
5948**
5949** Terms of p that are marked with EP_OuterON (and hence that come from
5950** the ON or USING clauses of OUTER JOINS) are excluded from the analysis.
5951**
5952** This routine is used to check if a LEFT JOIN can be converted into
5953** an ordinary JOIN. The p argument is the WHERE clause. If the WHERE
5954** clause requires that some column of the right table of the LEFT JOIN
5955** be non-NULL, then the LEFT JOIN can be safely converted into an
5956** ordinary join.
5957*/
5958int sqlite3ExprImpliesNonNullRow(Expr *p, int iTab){
5959 Walker w;
5960 p = sqlite3ExprSkipCollateAndLikely(p);
5961 if( p==0 ) return 0;
5962 if( p->op==TK_NOTNULL ){
5963 p = p->pLeft;
5964 }else{
5965 while( p->op==TK_AND ){
5966 if( sqlite3ExprImpliesNonNullRow(p->pLeft, iTab) ) return 1;
5967 p = p->pRight;
5968 }
5969 }
5970 w.xExprCallback = impliesNotNullRow;
5971 w.xSelectCallback = 0;
5972 w.xSelectCallback2 = 0;
5973 w.eCode = 0;
5974 w.u.iCur = iTab;
5975 sqlite3WalkExpr(&w, p);
5976 return w.eCode;
5977}
5978
5979/*
5980** An instance of the following structure is used by the tree walker
5981** to determine if an expression can be evaluated by reference to the
5982** index only, without having to do a search for the corresponding
5983** table entry. The IdxCover.pIdx field is the index. IdxCover.iCur
5984** is the cursor for the table.
5985*/
5986struct IdxCover {
5987 Index *pIdx; /* The index to be tested for coverage */
5988 int iCur; /* Cursor number for the table corresponding to the index */
5989};
5990
5991/*
5992** Check to see if there are references to columns in table
5993** pWalker->u.pIdxCover->iCur can be satisfied using the index
5994** pWalker->u.pIdxCover->pIdx.
5995*/
5996static int exprIdxCover(Walker *pWalker, Expr *pExpr){
5997 if( pExpr->op==TK_COLUMN
5998 && pExpr->iTable==pWalker->u.pIdxCover->iCur
5999 && sqlite3TableColumnToIndex(pWalker->u.pIdxCover->pIdx, pExpr->iColumn)<0
6000 ){
6001 pWalker->eCode = 1;
6002 return WRC_Abort;
6003 }
6004 return WRC_Continue;
6005}
6006
6007/*
6008** Determine if an index pIdx on table with cursor iCur contains will
6009** the expression pExpr. Return true if the index does cover the
6010** expression and false if the pExpr expression references table columns
6011** that are not found in the index pIdx.
6012**
6013** An index covering an expression means that the expression can be
6014** evaluated using only the index and without having to lookup the
6015** corresponding table entry.
6016*/
6017int sqlite3ExprCoveredByIndex(
6018 Expr *pExpr, /* The index to be tested */
6019 int iCur, /* The cursor number for the corresponding table */
6020 Index *pIdx /* The index that might be used for coverage */
6021){
6022 Walker w;
6023 struct IdxCover xcov;
6024 memset(&w, 0, sizeof(w));
6025 xcov.iCur = iCur;
6026 xcov.pIdx = pIdx;
6027 w.xExprCallback = exprIdxCover;
6028 w.u.pIdxCover = &xcov;
6029 sqlite3WalkExpr(&w, pExpr);
6030 return !w.eCode;
6031}
6032
6033
6034/* Structure used to pass information throught the Walker in order to
6035** implement sqlite3ReferencesSrcList().
6036*/
6037struct RefSrcList {
6038 sqlite3 *db; /* Database connection used for sqlite3DbRealloc() */
6039 SrcList *pRef; /* Looking for references to these tables */
6040 i64 nExclude; /* Number of tables to exclude from the search */
6041 int *aiExclude; /* Cursor IDs for tables to exclude from the search */
6042};
6043
6044/*
6045** Walker SELECT callbacks for sqlite3ReferencesSrcList().
6046**
6047** When entering a new subquery on the pExpr argument, add all FROM clause
6048** entries for that subquery to the exclude list.
6049**
6050** When leaving the subquery, remove those entries from the exclude list.
6051*/
6052static int selectRefEnter(Walker *pWalker, Select *pSelect){
6053 struct RefSrcList *p = pWalker->u.pRefSrcList;
6054 SrcList *pSrc = pSelect->pSrc;
6055 i64 i, j;
6056 int *piNew;
6057 if( pSrc->nSrc==0 ) return WRC_Continue;
6058 j = p->nExclude;
6059 p->nExclude += pSrc->nSrc;
6060 piNew = sqlite3DbRealloc(p->db, p->aiExclude, p->nExclude*sizeof(int));
6061 if( piNew==0 ){
6062 p->nExclude = 0;
6063 return WRC_Abort;
6064 }else{
6065 p->aiExclude = piNew;
6066 }
6067 for(i=0; i<pSrc->nSrc; i++, j++){
6068 p->aiExclude[j] = pSrc->a[i].iCursor;
6069 }
6070 return WRC_Continue;
6071}
6072static void selectRefLeave(Walker *pWalker, Select *pSelect){
6073 struct RefSrcList *p = pWalker->u.pRefSrcList;
6074 SrcList *pSrc = pSelect->pSrc;
6075 if( p->nExclude ){
6076 assert( p->nExclude>=pSrc->nSrc );
6077 p->nExclude -= pSrc->nSrc;
6078 }
6079}
6080
6081/* This is the Walker EXPR callback for sqlite3ReferencesSrcList().
6082**
6083** Set the 0x01 bit of pWalker->eCode if there is a reference to any
6084** of the tables shown in RefSrcList.pRef.
6085**
6086** Set the 0x02 bit of pWalker->eCode if there is a reference to a
6087** table is in neither RefSrcList.pRef nor RefSrcList.aiExclude.
6088*/
6089static int exprRefToSrcList(Walker *pWalker, Expr *pExpr){
6090 if( pExpr->op==TK_COLUMN
6091 || pExpr->op==TK_AGG_COLUMN
6092 ){
6093 int i;
6094 struct RefSrcList *p = pWalker->u.pRefSrcList;
6095 SrcList *pSrc = p->pRef;
6096 int nSrc = pSrc ? pSrc->nSrc : 0;
6097 for(i=0; i<nSrc; i++){
6098 if( pExpr->iTable==pSrc->a[i].iCursor ){
6099 pWalker->eCode |= 1;
6100 return WRC_Continue;
6101 }
6102 }
6103 for(i=0; i<p->nExclude && p->aiExclude[i]!=pExpr->iTable; i++){}
6104 if( i>=p->nExclude ){
6105 pWalker->eCode |= 2;
6106 }
6107 }
6108 return WRC_Continue;
6109}
6110
6111/*
6112** Check to see if pExpr references any tables in pSrcList.
6113** Possible return values:
6114**
6115** 1 pExpr does references a table in pSrcList.
6116**
6117** 0 pExpr references some table that is not defined in either
6118** pSrcList or in subqueries of pExpr itself.
6119**
6120** -1 pExpr only references no tables at all, or it only
6121** references tables defined in subqueries of pExpr itself.
6122**
6123** As currently used, pExpr is always an aggregate function call. That
6124** fact is exploited for efficiency.
6125*/
6126int sqlite3ReferencesSrcList(Parse *pParse, Expr *pExpr, SrcList *pSrcList){
6127 Walker w;
6128 struct RefSrcList x;
6129 assert( pParse->db!=0 );
6130 memset(&w, 0, sizeof(w));
6131 memset(&x, 0, sizeof(x));
6132 w.xExprCallback = exprRefToSrcList;
6133 w.xSelectCallback = selectRefEnter;
6134 w.xSelectCallback2 = selectRefLeave;
6135 w.u.pRefSrcList = &x;
6136 x.db = pParse->db;
6137 x.pRef = pSrcList;
6138 assert( pExpr->op==TK_AGG_FUNCTION );
6139 assert( ExprUseXList(pExpr) );
6140 sqlite3WalkExprList(&w, pExpr->x.pList);
6141#ifndef SQLITE_OMIT_WINDOWFUNC
6142 if( ExprHasProperty(pExpr, EP_WinFunc) ){
6143 sqlite3WalkExpr(&w, pExpr->y.pWin->pFilter);
6144 }
6145#endif
6146 if( x.aiExclude ) sqlite3DbNNFreeNN(pParse->db, x.aiExclude);
6147 if( w.eCode & 0x01 ){
6148 return 1;
6149 }else if( w.eCode ){
6150 return 0;
6151 }else{
6152 return -1;
6153 }
6154}
6155
6156/*
6157** This is a Walker expression node callback.
6158**
6159** For Expr nodes that contain pAggInfo pointers, make sure the AggInfo
6160** object that is referenced does not refer directly to the Expr. If
6161** it does, make a copy. This is done because the pExpr argument is
6162** subject to change.
6163**
6164** The copy is stored on pParse->pConstExpr with a register number of 0.
6165** This will cause the expression to be deleted automatically when the
6166** Parse object is destroyed, but the zero register number means that it
6167** will not generate any code in the preamble.
6168*/
6169static int agginfoPersistExprCb(Walker *pWalker, Expr *pExpr){
6170 if( ALWAYS(!ExprHasProperty(pExpr, EP_TokenOnly|EP_Reduced))
6171 && pExpr->pAggInfo!=0
6172 ){
6173 AggInfo *pAggInfo = pExpr->pAggInfo;
6174 int iAgg = pExpr->iAgg;
6175 Parse *pParse = pWalker->pParse;
6176 sqlite3 *db = pParse->db;
6177 if( pExpr->op!=TK_AGG_FUNCTION ){
6178 assert( pExpr->op==TK_AGG_COLUMN || pExpr->op==TK_IF_NULL_ROW );
6179 assert( iAgg>=0 && iAgg<pAggInfo->nColumn );
6180 if( pAggInfo->aCol[iAgg].pCExpr==pExpr ){
6181 pExpr = sqlite3ExprDup(db, pExpr, 0);
6182 if( pExpr ){
6183 pAggInfo->aCol[iAgg].pCExpr = pExpr;
6184 sqlite3ExprDeferredDelete(pParse, pExpr);
6185 }
6186 }
6187 }else{
6188 assert( pExpr->op==TK_AGG_FUNCTION );
6189 assert( iAgg>=0 && iAgg<pAggInfo->nFunc );
6190 if( pAggInfo->aFunc[iAgg].pFExpr==pExpr ){
6191 pExpr = sqlite3ExprDup(db, pExpr, 0);
6192 if( pExpr ){
6193 pAggInfo->aFunc[iAgg].pFExpr = pExpr;
6194 sqlite3ExprDeferredDelete(pParse, pExpr);
6195 }
6196 }
6197 }
6198 }
6199 return WRC_Continue;
6200}
6201
6202/*
6203** Initialize a Walker object so that will persist AggInfo entries referenced
6204** by the tree that is walked.
6205*/
6206void sqlite3AggInfoPersistWalkerInit(Walker *pWalker, Parse *pParse){
6207 memset(pWalker, 0, sizeof(*pWalker));
6208 pWalker->pParse = pParse;
6209 pWalker->xExprCallback = agginfoPersistExprCb;
6210 pWalker->xSelectCallback = sqlite3SelectWalkNoop;
6211}
6212
6213/*
6214** Add a new element to the pAggInfo->aCol[] array. Return the index of
6215** the new element. Return a negative number if malloc fails.
6216*/
6217static int addAggInfoColumn(sqlite3 *db, AggInfo *pInfo){
6218 int i;
6219 pInfo->aCol = sqlite3ArrayAllocate(
6220 db,
6221 pInfo->aCol,
6222 sizeof(pInfo->aCol[0]),
6223 &pInfo->nColumn,
6224 &i
6225 );
6226 return i;
6227}
6228
6229/*
6230** Add a new element to the pAggInfo->aFunc[] array. Return the index of
6231** the new element. Return a negative number if malloc fails.
6232*/
6233static int addAggInfoFunc(sqlite3 *db, AggInfo *pInfo){
6234 int i;
6235 pInfo->aFunc = sqlite3ArrayAllocate(
6236 db,
6237 pInfo->aFunc,
6238 sizeof(pInfo->aFunc[0]),
6239 &pInfo->nFunc,
6240 &i
6241 );
6242 return i;
6243}
6244
6245/*
6246** This is the xExprCallback for a tree walker. It is used to
6247** implement sqlite3ExprAnalyzeAggregates(). See sqlite3ExprAnalyzeAggregates
6248** for additional information.
6249*/
6250static int analyzeAggregate(Walker *pWalker, Expr *pExpr){
6251 int i;
6252 NameContext *pNC = pWalker->u.pNC;
6253 Parse *pParse = pNC->pParse;
6254 SrcList *pSrcList = pNC->pSrcList;
6255 AggInfo *pAggInfo = pNC->uNC.pAggInfo;
6256
6257 assert( pNC->ncFlags & NC_UAggInfo );
6258 switch( pExpr->op ){
6259 case TK_IF_NULL_ROW:
6260 case TK_AGG_COLUMN:
6261 case TK_COLUMN: {
6262 testcase( pExpr->op==TK_AGG_COLUMN );
6263 testcase( pExpr->op==TK_COLUMN );
6264 testcase( pExpr->op==TK_IF_NULL_ROW );
6265 /* Check to see if the column is in one of the tables in the FROM
6266 ** clause of the aggregate query */
6267 if( ALWAYS(pSrcList!=0) ){
6268 SrcItem *pItem = pSrcList->a;
6269 for(i=0; i<pSrcList->nSrc; i++, pItem++){
6270 struct AggInfo_col *pCol;
6271 assert( !ExprHasProperty(pExpr, EP_TokenOnly|EP_Reduced) );
6272 if( pExpr->iTable==pItem->iCursor ){
6273 /* If we reach this point, it means that pExpr refers to a table
6274 ** that is in the FROM clause of the aggregate query.
6275 **
6276 ** Make an entry for the column in pAggInfo->aCol[] if there
6277 ** is not an entry there already.
6278 */
6279 int k;
6280 pCol = pAggInfo->aCol;
6281 for(k=0; k<pAggInfo->nColumn; k++, pCol++){
6282 if( pCol->iTable==pExpr->iTable
6283 && pCol->iColumn==pExpr->iColumn
6284 && pExpr->op!=TK_IF_NULL_ROW
6285 ){
6286 break;
6287 }
6288 }
6289 if( (k>=pAggInfo->nColumn)
6290 && (k = addAggInfoColumn(pParse->db, pAggInfo))>=0
6291 ){
6292 pCol = &pAggInfo->aCol[k];
6293 assert( ExprUseYTab(pExpr) );
6294 pCol->pTab = pExpr->y.pTab;
6295 pCol->iTable = pExpr->iTable;
6296 pCol->iColumn = pExpr->iColumn;
6297 pCol->iMem = ++pParse->nMem;
6298 pCol->iSorterColumn = -1;
6299 pCol->pCExpr = pExpr;
6300 if( pAggInfo->pGroupBy && pExpr->op!=TK_IF_NULL_ROW ){
6301 int j, n;
6302 ExprList *pGB = pAggInfo->pGroupBy;
6303 struct ExprList_item *pTerm = pGB->a;
6304 n = pGB->nExpr;
6305 for(j=0; j<n; j++, pTerm++){
6306 Expr *pE = pTerm->pExpr;
6307 if( pE->op==TK_COLUMN
6308 && pE->iTable==pExpr->iTable
6309 && pE->iColumn==pExpr->iColumn
6310 ){
6311 pCol->iSorterColumn = j;
6312 break;
6313 }
6314 }
6315 }
6316 if( pCol->iSorterColumn<0 ){
6317 pCol->iSorterColumn = pAggInfo->nSortingColumn++;
6318 }
6319 }
6320 /* There is now an entry for pExpr in pAggInfo->aCol[] (either
6321 ** because it was there before or because we just created it).
6322 ** Convert the pExpr to be a TK_AGG_COLUMN referring to that
6323 ** pAggInfo->aCol[] entry.
6324 */
6325 ExprSetVVAProperty(pExpr, EP_NoReduce);
6326 pExpr->pAggInfo = pAggInfo;
6327 if( pExpr->op==TK_COLUMN ){
6328 pExpr->op = TK_AGG_COLUMN;
6329 }
6330 pExpr->iAgg = (i16)k;
6331 break;
6332 } /* endif pExpr->iTable==pItem->iCursor */
6333 } /* end loop over pSrcList */
6334 }
6335 return WRC_Prune;
6336 }
6337 case TK_AGG_FUNCTION: {
6338 if( (pNC->ncFlags & NC_InAggFunc)==0
6339 && pWalker->walkerDepth==pExpr->op2
6340 ){
6341 /* Check to see if pExpr is a duplicate of another aggregate
6342 ** function that is already in the pAggInfo structure
6343 */
6344 struct AggInfo_func *pItem = pAggInfo->aFunc;
6345 for(i=0; i<pAggInfo->nFunc; i++, pItem++){
6346 if( pItem->pFExpr==pExpr ) break;
6347 if( sqlite3ExprCompare(0, pItem->pFExpr, pExpr, -1)==0 ){
6348 break;
6349 }
6350 }
6351 if( i>=pAggInfo->nFunc ){
6352 /* pExpr is original. Make a new entry in pAggInfo->aFunc[]
6353 */
6354 u8 enc = ENC(pParse->db);
6355 i = addAggInfoFunc(pParse->db, pAggInfo);
6356 if( i>=0 ){
6357 assert( !ExprHasProperty(pExpr, EP_xIsSelect) );
6358 pItem = &pAggInfo->aFunc[i];
6359 pItem->pFExpr = pExpr;
6360 pItem->iMem = ++pParse->nMem;
6361 assert( ExprUseUToken(pExpr) );
6362 pItem->pFunc = sqlite3FindFunction(pParse->db,
6363 pExpr->u.zToken,
6364 pExpr->x.pList ? pExpr->x.pList->nExpr : 0, enc, 0);
6365 if( pExpr->flags & EP_Distinct ){
6366 pItem->iDistinct = pParse->nTab++;
6367 }else{
6368 pItem->iDistinct = -1;
6369 }
6370 }
6371 }
6372 /* Make pExpr point to the appropriate pAggInfo->aFunc[] entry
6373 */
6374 assert( !ExprHasProperty(pExpr, EP_TokenOnly|EP_Reduced) );
6375 ExprSetVVAProperty(pExpr, EP_NoReduce);
6376 pExpr->iAgg = (i16)i;
6377 pExpr->pAggInfo = pAggInfo;
6378 return WRC_Prune;
6379 }else{
6380 return WRC_Continue;
6381 }
6382 }
6383 }
6384 return WRC_Continue;
6385}
6386
6387/*
6388** Analyze the pExpr expression looking for aggregate functions and
6389** for variables that need to be added to AggInfo object that pNC->pAggInfo
6390** points to. Additional entries are made on the AggInfo object as
6391** necessary.
6392**
6393** This routine should only be called after the expression has been
6394** analyzed by sqlite3ResolveExprNames().
6395*/
6396void sqlite3ExprAnalyzeAggregates(NameContext *pNC, Expr *pExpr){
6397 Walker w;
6398 w.xExprCallback = analyzeAggregate;
6399 w.xSelectCallback = sqlite3WalkerDepthIncrease;
6400 w.xSelectCallback2 = sqlite3WalkerDepthDecrease;
6401 w.walkerDepth = 0;
6402 w.u.pNC = pNC;
6403 w.pParse = 0;
6404 assert( pNC->pSrcList!=0 );
6405 sqlite3WalkExpr(&w, pExpr);
6406}
6407
6408/*
6409** Call sqlite3ExprAnalyzeAggregates() for every expression in an
6410** expression list. Return the number of errors.
6411**
6412** If an error is found, the analysis is cut short.
6413*/
6414void sqlite3ExprAnalyzeAggList(NameContext *pNC, ExprList *pList){
6415 struct ExprList_item *pItem;
6416 int i;
6417 if( pList ){
6418 for(pItem=pList->a, i=0; i<pList->nExpr; i++, pItem++){
6419 sqlite3ExprAnalyzeAggregates(pNC, pItem->pExpr);
6420 }
6421 }
6422}
6423
6424/*
6425** Allocate a single new register for use to hold some intermediate result.
6426*/
6427int sqlite3GetTempReg(Parse *pParse){
6428 if( pParse->nTempReg==0 ){
6429 return ++pParse->nMem;
6430 }
6431 return pParse->aTempReg[--pParse->nTempReg];
6432}
6433
6434/*
6435** Deallocate a register, making available for reuse for some other
6436** purpose.
6437*/
6438void sqlite3ReleaseTempReg(Parse *pParse, int iReg){
6439 if( iReg ){
6440 sqlite3VdbeReleaseRegisters(pParse, iReg, 1, 0, 0);
6441 if( pParse->nTempReg<ArraySize(pParse->aTempReg) ){
6442 pParse->aTempReg[pParse->nTempReg++] = iReg;
6443 }
6444 }
6445}
6446
6447/*
6448** Allocate or deallocate a block of nReg consecutive registers.
6449*/
6450int sqlite3GetTempRange(Parse *pParse, int nReg){
6451 int i, n;
6452 if( nReg==1 ) return sqlite3GetTempReg(pParse);
6453 i = pParse->iRangeReg;
6454 n = pParse->nRangeReg;
6455 if( nReg<=n ){
6456 pParse->iRangeReg += nReg;
6457 pParse->nRangeReg -= nReg;
6458 }else{
6459 i = pParse->nMem+1;
6460 pParse->nMem += nReg;
6461 }
6462 return i;
6463}
6464void sqlite3ReleaseTempRange(Parse *pParse, int iReg, int nReg){
6465 if( nReg==1 ){
6466 sqlite3ReleaseTempReg(pParse, iReg);
6467 return;
6468 }
6469 sqlite3VdbeReleaseRegisters(pParse, iReg, nReg, 0, 0);
6470 if( nReg>pParse->nRangeReg ){
6471 pParse->nRangeReg = nReg;
6472 pParse->iRangeReg = iReg;
6473 }
6474}
6475
6476/*
6477** Mark all temporary registers as being unavailable for reuse.
6478**
6479** Always invoke this procedure after coding a subroutine or co-routine
6480** that might be invoked from other parts of the code, to ensure that
6481** the sub/co-routine does not use registers in common with the code that
6482** invokes the sub/co-routine.
6483*/
6484void sqlite3ClearTempRegCache(Parse *pParse){
6485 pParse->nTempReg = 0;
6486 pParse->nRangeReg = 0;
6487}
6488
6489/*
6490** Validate that no temporary register falls within the range of
6491** iFirst..iLast, inclusive. This routine is only call from within assert()
6492** statements.
6493*/
6494#ifdef SQLITE_DEBUG
6495int sqlite3NoTempsInRange(Parse *pParse, int iFirst, int iLast){
6496 int i;
6497 if( pParse->nRangeReg>0
6498 && pParse->iRangeReg+pParse->nRangeReg > iFirst
6499 && pParse->iRangeReg <= iLast
6500 ){
6501 return 0;
6502 }
6503 for(i=0; i<pParse->nTempReg; i++){
6504 if( pParse->aTempReg[i]>=iFirst && pParse->aTempReg[i]<=iLast ){
6505 return 0;
6506 }
6507 }
6508 return 1;
6509}
6510#endif /* SQLITE_DEBUG */
6511