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 */
18 static void exprCodeBetween(Parse*,Expr*,int,void(*)(Parse*,Expr*,int,int),int);
19 static int exprCodeVector(Parse *pParse, Expr *p, int *piToFree);
20
21 /*
22 ** Return the affinity character for a single column of a table.
23 */
sqlite3TableColumnAffinity(Table * pTab,int iCol)24 char sqlite3TableColumnAffinity(Table *pTab, int iCol){
25 assert( iCol<pTab->nCol );
26 return iCol>=0 ? pTab->aCol[iCol].affinity : SQLITE_AFF_INTEGER;
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 */
sqlite3ExprAffinity(Expr * pExpr)45 char sqlite3ExprAffinity(Expr *pExpr){
46 int op;
47 while( ExprHasProperty(pExpr, EP_Skip) ){
48 assert( pExpr->op==TK_COLLATE );
49 pExpr = pExpr->pLeft;
50 assert( pExpr!=0 );
51 }
52 op = pExpr->op;
53 if( op==TK_SELECT ){
54 assert( pExpr->flags&EP_xIsSelect );
55 return sqlite3ExprAffinity(pExpr->x.pSelect->pEList->a[0].pExpr);
56 }
57 if( op==TK_REGISTER ) op = pExpr->op2;
58 #ifndef SQLITE_OMIT_CAST
59 if( op==TK_CAST ){
60 assert( !ExprHasProperty(pExpr, EP_IntValue) );
61 return sqlite3AffinityType(pExpr->u.zToken, 0);
62 }
63 #endif
64 if( (op==TK_AGG_COLUMN || op==TK_COLUMN) && pExpr->y.pTab ){
65 return sqlite3TableColumnAffinity(pExpr->y.pTab, pExpr->iColumn);
66 }
67 if( op==TK_SELECT_COLUMN ){
68 assert( pExpr->pLeft->flags&EP_xIsSelect );
69 return sqlite3ExprAffinity(
70 pExpr->pLeft->x.pSelect->pEList->a[pExpr->iColumn].pExpr
71 );
72 }
73 if( op==TK_VECTOR ){
74 return sqlite3ExprAffinity(pExpr->x.pList->a[0].pExpr);
75 }
76 return pExpr->affExpr;
77 }
78
79 /*
80 ** Set the collating sequence for expression pExpr to be the collating
81 ** sequence named by pToken. Return a pointer to a new Expr node that
82 ** implements the COLLATE operator.
83 **
84 ** If a memory allocation error occurs, that fact is recorded in pParse->db
85 ** and the pExpr parameter is returned unchanged.
86 */
sqlite3ExprAddCollateToken(Parse * pParse,Expr * pExpr,const Token * pCollName,int dequote)87 Expr *sqlite3ExprAddCollateToken(
88 Parse *pParse, /* Parsing context */
89 Expr *pExpr, /* Add the "COLLATE" clause to this expression */
90 const Token *pCollName, /* Name of collating sequence */
91 int dequote /* True to dequote pCollName */
92 ){
93 if( pCollName->n>0 ){
94 Expr *pNew = sqlite3ExprAlloc(pParse->db, TK_COLLATE, pCollName, dequote);
95 if( pNew ){
96 pNew->pLeft = pExpr;
97 pNew->flags |= EP_Collate|EP_Skip;
98 pExpr = pNew;
99 }
100 }
101 return pExpr;
102 }
sqlite3ExprAddCollateString(Parse * pParse,Expr * pExpr,const char * zC)103 Expr *sqlite3ExprAddCollateString(Parse *pParse, Expr *pExpr, const char *zC){
104 Token s;
105 assert( zC!=0 );
106 sqlite3TokenInit(&s, (char*)zC);
107 return sqlite3ExprAddCollateToken(pParse, pExpr, &s, 0);
108 }
109
110 /*
111 ** Skip over any TK_COLLATE operators.
112 */
sqlite3ExprSkipCollate(Expr * pExpr)113 Expr *sqlite3ExprSkipCollate(Expr *pExpr){
114 while( pExpr && ExprHasProperty(pExpr, EP_Skip) ){
115 assert( pExpr->op==TK_COLLATE );
116 pExpr = pExpr->pLeft;
117 }
118 return pExpr;
119 }
120
121 /*
122 ** Skip over any TK_COLLATE operators and/or any unlikely()
123 ** or likelihood() or likely() functions at the root of an
124 ** expression.
125 */
sqlite3ExprSkipCollateAndLikely(Expr * pExpr)126 Expr *sqlite3ExprSkipCollateAndLikely(Expr *pExpr){
127 while( pExpr && ExprHasProperty(pExpr, EP_Skip|EP_Unlikely) ){
128 if( ExprHasProperty(pExpr, EP_Unlikely) ){
129 assert( !ExprHasProperty(pExpr, EP_xIsSelect) );
130 assert( pExpr->x.pList->nExpr>0 );
131 assert( pExpr->op==TK_FUNCTION );
132 pExpr = pExpr->x.pList->a[0].pExpr;
133 }else{
134 assert( pExpr->op==TK_COLLATE );
135 pExpr = pExpr->pLeft;
136 }
137 }
138 return pExpr;
139 }
140
141 /*
142 ** Return the collation sequence for the expression pExpr. If
143 ** there is no defined collating sequence, return NULL.
144 **
145 ** See also: sqlite3ExprNNCollSeq()
146 **
147 ** The sqlite3ExprNNCollSeq() works the same exact that it returns the
148 ** default collation if pExpr has no defined collation.
149 **
150 ** The collating sequence might be determined by a COLLATE operator
151 ** or by the presence of a column with a defined collating sequence.
152 ** COLLATE operators take first precedence. Left operands take
153 ** precedence over right operands.
154 */
sqlite3ExprCollSeq(Parse * pParse,Expr * pExpr)155 CollSeq *sqlite3ExprCollSeq(Parse *pParse, Expr *pExpr){
156 sqlite3 *db = pParse->db;
157 CollSeq *pColl = 0;
158 Expr *p = pExpr;
159 while( p ){
160 int op = p->op;
161 if( op==TK_REGISTER ) op = p->op2;
162 if( (op==TK_AGG_COLUMN || op==TK_COLUMN || op==TK_TRIGGER)
163 && p->y.pTab!=0
164 ){
165 /* op==TK_REGISTER && p->y.pTab!=0 happens when pExpr was originally
166 ** a TK_COLUMN but was previously evaluated and cached in a register */
167 int j = p->iColumn;
168 if( j>=0 ){
169 const char *zColl = p->y.pTab->aCol[j].zColl;
170 pColl = sqlite3FindCollSeq(db, ENC(db), zColl, 0);
171 }
172 break;
173 }
174 if( op==TK_CAST || op==TK_UPLUS ){
175 p = p->pLeft;
176 continue;
177 }
178 if( op==TK_VECTOR ){
179 p = p->x.pList->a[0].pExpr;
180 continue;
181 }
182 if( op==TK_COLLATE ){
183 pColl = sqlite3GetCollSeq(pParse, ENC(db), 0, p->u.zToken);
184 break;
185 }
186 if( p->flags & EP_Collate ){
187 if( p->pLeft && (p->pLeft->flags & EP_Collate)!=0 ){
188 p = p->pLeft;
189 }else{
190 Expr *pNext = p->pRight;
191 /* The Expr.x union is never used at the same time as Expr.pRight */
192 assert( p->x.pList==0 || p->pRight==0 );
193 if( p->x.pList!=0
194 && !db->mallocFailed
195 && ALWAYS(!ExprHasProperty(p, EP_xIsSelect))
196 ){
197 int i;
198 for(i=0; i<p->x.pList->nExpr; i++){
199 if( ExprHasProperty(p->x.pList->a[i].pExpr, EP_Collate) ){
200 pNext = p->x.pList->a[i].pExpr;
201 break;
202 }
203 }
204 }
205 p = pNext;
206 }
207 }else{
208 break;
209 }
210 }
211 if( sqlite3CheckCollSeq(pParse, pColl) ){
212 pColl = 0;
213 }
214 return pColl;
215 }
216
217 /*
218 ** Return the collation sequence for the expression pExpr. If
219 ** there is no defined collating sequence, return a pointer to the
220 ** defautl collation sequence.
221 **
222 ** See also: sqlite3ExprCollSeq()
223 **
224 ** The sqlite3ExprCollSeq() routine works the same except that it
225 ** returns NULL if there is no defined collation.
226 */
sqlite3ExprNNCollSeq(Parse * pParse,Expr * pExpr)227 CollSeq *sqlite3ExprNNCollSeq(Parse *pParse, Expr *pExpr){
228 CollSeq *p = sqlite3ExprCollSeq(pParse, pExpr);
229 if( p==0 ) p = pParse->db->pDfltColl;
230 assert( p!=0 );
231 return p;
232 }
233
234 /*
235 ** Return TRUE if the two expressions have equivalent collating sequences.
236 */
sqlite3ExprCollSeqMatch(Parse * pParse,Expr * pE1,Expr * pE2)237 int sqlite3ExprCollSeqMatch(Parse *pParse, Expr *pE1, Expr *pE2){
238 CollSeq *pColl1 = sqlite3ExprNNCollSeq(pParse, pE1);
239 CollSeq *pColl2 = sqlite3ExprNNCollSeq(pParse, pE2);
240 return sqlite3StrICmp(pColl1->zName, pColl2->zName)==0;
241 }
242
243 /*
244 ** pExpr is an operand of a comparison operator. aff2 is the
245 ** type affinity of the other operand. This routine returns the
246 ** type affinity that should be used for the comparison operator.
247 */
sqlite3CompareAffinity(Expr * pExpr,char aff2)248 char sqlite3CompareAffinity(Expr *pExpr, char aff2){
249 char aff1 = sqlite3ExprAffinity(pExpr);
250 if( aff1>SQLITE_AFF_NONE && aff2>SQLITE_AFF_NONE ){
251 /* Both sides of the comparison are columns. If one has numeric
252 ** affinity, use that. Otherwise use no affinity.
253 */
254 if( sqlite3IsNumericAffinity(aff1) || sqlite3IsNumericAffinity(aff2) ){
255 return SQLITE_AFF_NUMERIC;
256 }else{
257 return SQLITE_AFF_BLOB;
258 }
259 }else{
260 /* One side is a column, the other is not. Use the columns affinity. */
261 assert( aff1<=SQLITE_AFF_NONE || aff2<=SQLITE_AFF_NONE );
262 return (aff1<=SQLITE_AFF_NONE ? aff2 : aff1) | SQLITE_AFF_NONE;
263 }
264 }
265
266 /*
267 ** pExpr is a comparison operator. Return the type affinity that should
268 ** be applied to both operands prior to doing the comparison.
269 */
comparisonAffinity(Expr * pExpr)270 static char comparisonAffinity(Expr *pExpr){
271 char aff;
272 assert( pExpr->op==TK_EQ || pExpr->op==TK_IN || pExpr->op==TK_LT ||
273 pExpr->op==TK_GT || pExpr->op==TK_GE || pExpr->op==TK_LE ||
274 pExpr->op==TK_NE || pExpr->op==TK_IS || pExpr->op==TK_ISNOT );
275 assert( pExpr->pLeft );
276 aff = sqlite3ExprAffinity(pExpr->pLeft);
277 if( pExpr->pRight ){
278 aff = sqlite3CompareAffinity(pExpr->pRight, aff);
279 }else if( ExprHasProperty(pExpr, EP_xIsSelect) ){
280 aff = sqlite3CompareAffinity(pExpr->x.pSelect->pEList->a[0].pExpr, aff);
281 }else if( aff==0 ){
282 aff = SQLITE_AFF_BLOB;
283 }
284 return aff;
285 }
286
287 /*
288 ** pExpr is a comparison expression, eg. '=', '<', IN(...) etc.
289 ** idx_affinity is the affinity of an indexed column. Return true
290 ** if the index with affinity idx_affinity may be used to implement
291 ** the comparison in pExpr.
292 */
sqlite3IndexAffinityOk(Expr * pExpr,char idx_affinity)293 int sqlite3IndexAffinityOk(Expr *pExpr, char idx_affinity){
294 char aff = comparisonAffinity(pExpr);
295 if( aff<SQLITE_AFF_TEXT ){
296 return 1;
297 }
298 if( aff==SQLITE_AFF_TEXT ){
299 return idx_affinity==SQLITE_AFF_TEXT;
300 }
301 return sqlite3IsNumericAffinity(idx_affinity);
302 }
303
304 /*
305 ** Return the P5 value that should be used for a binary comparison
306 ** opcode (OP_Eq, OP_Ge etc.) used to compare pExpr1 and pExpr2.
307 */
binaryCompareP5(Expr * pExpr1,Expr * pExpr2,int jumpIfNull)308 static u8 binaryCompareP5(Expr *pExpr1, Expr *pExpr2, int jumpIfNull){
309 u8 aff = (char)sqlite3ExprAffinity(pExpr2);
310 aff = (u8)sqlite3CompareAffinity(pExpr1, aff) | (u8)jumpIfNull;
311 return aff;
312 }
313
314 /*
315 ** Return a pointer to the collation sequence that should be used by
316 ** a binary comparison operator comparing pLeft and pRight.
317 **
318 ** If the left hand expression has a collating sequence type, then it is
319 ** used. Otherwise the collation sequence for the right hand expression
320 ** is used, or the default (BINARY) if neither expression has a collating
321 ** type.
322 **
323 ** Argument pRight (but not pLeft) may be a null pointer. In this case,
324 ** it is not considered.
325 */
sqlite3BinaryCompareCollSeq(Parse * pParse,Expr * pLeft,Expr * pRight)326 CollSeq *sqlite3BinaryCompareCollSeq(
327 Parse *pParse,
328 Expr *pLeft,
329 Expr *pRight
330 ){
331 CollSeq *pColl;
332 assert( pLeft );
333 if( pLeft->flags & EP_Collate ){
334 pColl = sqlite3ExprCollSeq(pParse, pLeft);
335 }else if( pRight && (pRight->flags & EP_Collate)!=0 ){
336 pColl = sqlite3ExprCollSeq(pParse, pRight);
337 }else{
338 pColl = sqlite3ExprCollSeq(pParse, pLeft);
339 if( !pColl ){
340 pColl = sqlite3ExprCollSeq(pParse, pRight);
341 }
342 }
343 return pColl;
344 }
345
346 /* Expresssion p is a comparison operator. Return a collation sequence
347 ** appropriate for the comparison operator.
348 **
349 ** This is normally just a wrapper around sqlite3BinaryCompareCollSeq().
350 ** However, if the OP_Commuted flag is set, then the order of the operands
351 ** is reversed in the sqlite3BinaryCompareCollSeq() call so that the
352 ** correct collating sequence is found.
353 */
sqlite3ExprCompareCollSeq(Parse * pParse,Expr * p)354 CollSeq *sqlite3ExprCompareCollSeq(Parse *pParse, Expr *p){
355 if( ExprHasProperty(p, EP_Commuted) ){
356 return sqlite3BinaryCompareCollSeq(pParse, p->pRight, p->pLeft);
357 }else{
358 return sqlite3BinaryCompareCollSeq(pParse, p->pLeft, p->pRight);
359 }
360 }
361
362 /*
363 ** Generate code for a comparison operator.
364 */
codeCompare(Parse * pParse,Expr * pLeft,Expr * pRight,int opcode,int in1,int in2,int dest,int jumpIfNull,int isCommuted)365 static int codeCompare(
366 Parse *pParse, /* The parsing (and code generating) context */
367 Expr *pLeft, /* The left operand */
368 Expr *pRight, /* The right operand */
369 int opcode, /* The comparison opcode */
370 int in1, int in2, /* Register holding operands */
371 int dest, /* Jump here if true. */
372 int jumpIfNull, /* If true, jump if either operand is NULL */
373 int isCommuted /* The comparison has been commuted */
374 ){
375 int p5;
376 int addr;
377 CollSeq *p4;
378
379 if( pParse->nErr ) return 0;
380 if( isCommuted ){
381 p4 = sqlite3BinaryCompareCollSeq(pParse, pRight, pLeft);
382 }else{
383 p4 = sqlite3BinaryCompareCollSeq(pParse, pLeft, pRight);
384 }
385 p5 = binaryCompareP5(pLeft, pRight, jumpIfNull);
386 addr = sqlite3VdbeAddOp4(pParse->pVdbe, opcode, in2, dest, in1,
387 (void*)p4, P4_COLLSEQ);
388 sqlite3VdbeChangeP5(pParse->pVdbe, (u8)p5);
389 return addr;
390 }
391
392 /*
393 ** Return true if expression pExpr is a vector, or false otherwise.
394 **
395 ** A vector is defined as any expression that results in two or more
396 ** columns of result. Every TK_VECTOR node is an vector because the
397 ** parser will not generate a TK_VECTOR with fewer than two entries.
398 ** But a TK_SELECT might be either a vector or a scalar. It is only
399 ** considered a vector if it has two or more result columns.
400 */
sqlite3ExprIsVector(Expr * pExpr)401 int sqlite3ExprIsVector(Expr *pExpr){
402 return sqlite3ExprVectorSize(pExpr)>1;
403 }
404
405 /*
406 ** If the expression passed as the only argument is of type TK_VECTOR
407 ** return the number of expressions in the vector. Or, if the expression
408 ** is a sub-select, return the number of columns in the sub-select. For
409 ** any other type of expression, return 1.
410 */
sqlite3ExprVectorSize(Expr * pExpr)411 int sqlite3ExprVectorSize(Expr *pExpr){
412 u8 op = pExpr->op;
413 if( op==TK_REGISTER ) op = pExpr->op2;
414 if( op==TK_VECTOR ){
415 return pExpr->x.pList->nExpr;
416 }else if( op==TK_SELECT ){
417 return pExpr->x.pSelect->pEList->nExpr;
418 }else{
419 return 1;
420 }
421 }
422
423 /*
424 ** Return a pointer to a subexpression of pVector that is the i-th
425 ** column of the vector (numbered starting with 0). The caller must
426 ** ensure that i is within range.
427 **
428 ** If pVector is really a scalar (and "scalar" here includes subqueries
429 ** that return a single column!) then return pVector unmodified.
430 **
431 ** pVector retains ownership of the returned subexpression.
432 **
433 ** If the vector is a (SELECT ...) then the expression returned is
434 ** just the expression for the i-th term of the result set, and may
435 ** not be ready for evaluation because the table cursor has not yet
436 ** been positioned.
437 */
sqlite3VectorFieldSubexpr(Expr * pVector,int i)438 Expr *sqlite3VectorFieldSubexpr(Expr *pVector, int i){
439 assert( i<sqlite3ExprVectorSize(pVector) );
440 if( sqlite3ExprIsVector(pVector) ){
441 assert( pVector->op2==0 || pVector->op==TK_REGISTER );
442 if( pVector->op==TK_SELECT || pVector->op2==TK_SELECT ){
443 return pVector->x.pSelect->pEList->a[i].pExpr;
444 }else{
445 return pVector->x.pList->a[i].pExpr;
446 }
447 }
448 return pVector;
449 }
450
451 /*
452 ** Compute and return a new Expr object which when passed to
453 ** sqlite3ExprCode() will generate all necessary code to compute
454 ** the iField-th column of the vector expression pVector.
455 **
456 ** It is ok for pVector to be a scalar (as long as iField==0).
457 ** In that case, this routine works like sqlite3ExprDup().
458 **
459 ** The caller owns the returned Expr object and is responsible for
460 ** ensuring that the returned value eventually gets freed.
461 **
462 ** The caller retains ownership of pVector. If pVector is a TK_SELECT,
463 ** then the returned object will reference pVector and so pVector must remain
464 ** valid for the life of the returned object. If pVector is a TK_VECTOR
465 ** or a scalar expression, then it can be deleted as soon as this routine
466 ** returns.
467 **
468 ** A trick to cause a TK_SELECT pVector to be deleted together with
469 ** the returned Expr object is to attach the pVector to the pRight field
470 ** of the returned TK_SELECT_COLUMN Expr object.
471 */
sqlite3ExprForVectorField(Parse * pParse,Expr * pVector,int iField)472 Expr *sqlite3ExprForVectorField(
473 Parse *pParse, /* Parsing context */
474 Expr *pVector, /* The vector. List of expressions or a sub-SELECT */
475 int iField /* Which column of the vector to return */
476 ){
477 Expr *pRet;
478 if( pVector->op==TK_SELECT ){
479 assert( pVector->flags & EP_xIsSelect );
480 /* The TK_SELECT_COLUMN Expr node:
481 **
482 ** pLeft: pVector containing TK_SELECT. Not deleted.
483 ** pRight: not used. But recursively deleted.
484 ** iColumn: Index of a column in pVector
485 ** iTable: 0 or the number of columns on the LHS of an assignment
486 ** pLeft->iTable: First in an array of register holding result, or 0
487 ** if the result is not yet computed.
488 **
489 ** sqlite3ExprDelete() specifically skips the recursive delete of
490 ** pLeft on TK_SELECT_COLUMN nodes. But pRight is followed, so pVector
491 ** can be attached to pRight to cause this node to take ownership of
492 ** pVector. Typically there will be multiple TK_SELECT_COLUMN nodes
493 ** with the same pLeft pointer to the pVector, but only one of them
494 ** will own the pVector.
495 */
496 pRet = sqlite3PExpr(pParse, TK_SELECT_COLUMN, 0, 0);
497 if( pRet ){
498 pRet->iColumn = iField;
499 pRet->pLeft = pVector;
500 }
501 assert( pRet==0 || pRet->iTable==0 );
502 }else{
503 if( pVector->op==TK_VECTOR ) pVector = pVector->x.pList->a[iField].pExpr;
504 pRet = sqlite3ExprDup(pParse->db, pVector, 0);
505 sqlite3RenameTokenRemap(pParse, pRet, pVector);
506 }
507 return pRet;
508 }
509
510 /*
511 ** If expression pExpr is of type TK_SELECT, generate code to evaluate
512 ** it. Return the register in which the result is stored (or, if the
513 ** sub-select returns more than one column, the first in an array
514 ** of registers in which the result is stored).
515 **
516 ** If pExpr is not a TK_SELECT expression, return 0.
517 */
exprCodeSubselect(Parse * pParse,Expr * pExpr)518 static int exprCodeSubselect(Parse *pParse, Expr *pExpr){
519 int reg = 0;
520 #ifndef SQLITE_OMIT_SUBQUERY
521 if( pExpr->op==TK_SELECT ){
522 reg = sqlite3CodeSubselect(pParse, pExpr);
523 }
524 #endif
525 return reg;
526 }
527
528 /*
529 ** Argument pVector points to a vector expression - either a TK_VECTOR
530 ** or TK_SELECT that returns more than one column. This function returns
531 ** the register number of a register that contains the value of
532 ** element iField of the vector.
533 **
534 ** If pVector is a TK_SELECT expression, then code for it must have
535 ** already been generated using the exprCodeSubselect() routine. In this
536 ** case parameter regSelect should be the first in an array of registers
537 ** containing the results of the sub-select.
538 **
539 ** If pVector is of type TK_VECTOR, then code for the requested field
540 ** is generated. In this case (*pRegFree) may be set to the number of
541 ** a temporary register to be freed by the caller before returning.
542 **
543 ** Before returning, output parameter (*ppExpr) is set to point to the
544 ** Expr object corresponding to element iElem of the vector.
545 */
exprVectorRegister(Parse * pParse,Expr * pVector,int iField,int regSelect,Expr ** ppExpr,int * pRegFree)546 static int exprVectorRegister(
547 Parse *pParse, /* Parse context */
548 Expr *pVector, /* Vector to extract element from */
549 int iField, /* Field to extract from pVector */
550 int regSelect, /* First in array of registers */
551 Expr **ppExpr, /* OUT: Expression element */
552 int *pRegFree /* OUT: Temp register to free */
553 ){
554 u8 op = pVector->op;
555 assert( op==TK_VECTOR || op==TK_REGISTER || op==TK_SELECT );
556 if( op==TK_REGISTER ){
557 *ppExpr = sqlite3VectorFieldSubexpr(pVector, iField);
558 return pVector->iTable+iField;
559 }
560 if( op==TK_SELECT ){
561 *ppExpr = pVector->x.pSelect->pEList->a[iField].pExpr;
562 return regSelect+iField;
563 }
564 *ppExpr = pVector->x.pList->a[iField].pExpr;
565 return sqlite3ExprCodeTemp(pParse, *ppExpr, pRegFree);
566 }
567
568 /*
569 ** Expression pExpr is a comparison between two vector values. Compute
570 ** the result of the comparison (1, 0, or NULL) and write that
571 ** result into register dest.
572 **
573 ** The caller must satisfy the following preconditions:
574 **
575 ** if pExpr->op==TK_IS: op==TK_EQ and p5==SQLITE_NULLEQ
576 ** if pExpr->op==TK_ISNOT: op==TK_NE and p5==SQLITE_NULLEQ
577 ** otherwise: op==pExpr->op and p5==0
578 */
codeVectorCompare(Parse * pParse,Expr * pExpr,int dest,u8 op,u8 p5)579 static void codeVectorCompare(
580 Parse *pParse, /* Code generator context */
581 Expr *pExpr, /* The comparison operation */
582 int dest, /* Write results into this register */
583 u8 op, /* Comparison operator */
584 u8 p5 /* SQLITE_NULLEQ or zero */
585 ){
586 Vdbe *v = pParse->pVdbe;
587 Expr *pLeft = pExpr->pLeft;
588 Expr *pRight = pExpr->pRight;
589 int nLeft = sqlite3ExprVectorSize(pLeft);
590 int i;
591 int regLeft = 0;
592 int regRight = 0;
593 u8 opx = op;
594 int addrDone = sqlite3VdbeMakeLabel(pParse);
595 int isCommuted = ExprHasProperty(pExpr,EP_Commuted);
596
597 if( pParse->nErr ) return;
598 if( nLeft!=sqlite3ExprVectorSize(pRight) ){
599 sqlite3ErrorMsg(pParse, "row value misused");
600 return;
601 }
602 assert( pExpr->op==TK_EQ || pExpr->op==TK_NE
603 || pExpr->op==TK_IS || pExpr->op==TK_ISNOT
604 || pExpr->op==TK_LT || pExpr->op==TK_GT
605 || pExpr->op==TK_LE || pExpr->op==TK_GE
606 );
607 assert( pExpr->op==op || (pExpr->op==TK_IS && op==TK_EQ)
608 || (pExpr->op==TK_ISNOT && op==TK_NE) );
609 assert( p5==0 || pExpr->op!=op );
610 assert( p5==SQLITE_NULLEQ || pExpr->op==op );
611
612 p5 |= SQLITE_STOREP2;
613 if( opx==TK_LE ) opx = TK_LT;
614 if( opx==TK_GE ) opx = TK_GT;
615
616 regLeft = exprCodeSubselect(pParse, pLeft);
617 regRight = exprCodeSubselect(pParse, pRight);
618
619 for(i=0; 1 /*Loop exits by "break"*/; i++){
620 int regFree1 = 0, regFree2 = 0;
621 Expr *pL, *pR;
622 int r1, r2;
623 assert( i>=0 && i<nLeft );
624 r1 = exprVectorRegister(pParse, pLeft, i, regLeft, &pL, ®Free1);
625 r2 = exprVectorRegister(pParse, pRight, i, regRight, &pR, ®Free2);
626 codeCompare(pParse, pL, pR, opx, r1, r2, dest, p5, isCommuted);
627 testcase(op==OP_Lt); VdbeCoverageIf(v,op==OP_Lt);
628 testcase(op==OP_Le); VdbeCoverageIf(v,op==OP_Le);
629 testcase(op==OP_Gt); VdbeCoverageIf(v,op==OP_Gt);
630 testcase(op==OP_Ge); VdbeCoverageIf(v,op==OP_Ge);
631 testcase(op==OP_Eq); VdbeCoverageIf(v,op==OP_Eq);
632 testcase(op==OP_Ne); VdbeCoverageIf(v,op==OP_Ne);
633 sqlite3ReleaseTempReg(pParse, regFree1);
634 sqlite3ReleaseTempReg(pParse, regFree2);
635 if( i==nLeft-1 ){
636 break;
637 }
638 if( opx==TK_EQ ){
639 sqlite3VdbeAddOp2(v, OP_IfNot, dest, addrDone); VdbeCoverage(v);
640 p5 |= SQLITE_KEEPNULL;
641 }else if( opx==TK_NE ){
642 sqlite3VdbeAddOp2(v, OP_If, dest, addrDone); VdbeCoverage(v);
643 p5 |= SQLITE_KEEPNULL;
644 }else{
645 assert( op==TK_LT || op==TK_GT || op==TK_LE || op==TK_GE );
646 sqlite3VdbeAddOp2(v, OP_ElseNotEq, 0, addrDone);
647 VdbeCoverageIf(v, op==TK_LT);
648 VdbeCoverageIf(v, op==TK_GT);
649 VdbeCoverageIf(v, op==TK_LE);
650 VdbeCoverageIf(v, op==TK_GE);
651 if( i==nLeft-2 ) opx = op;
652 }
653 }
654 sqlite3VdbeResolveLabel(v, addrDone);
655 }
656
657 #if SQLITE_MAX_EXPR_DEPTH>0
658 /*
659 ** Check that argument nHeight is less than or equal to the maximum
660 ** expression depth allowed. If it is not, leave an error message in
661 ** pParse.
662 */
sqlite3ExprCheckHeight(Parse * pParse,int nHeight)663 int sqlite3ExprCheckHeight(Parse *pParse, int nHeight){
664 int rc = SQLITE_OK;
665 int mxHeight = pParse->db->aLimit[SQLITE_LIMIT_EXPR_DEPTH];
666 if( nHeight>mxHeight ){
667 sqlite3ErrorMsg(pParse,
668 "Expression tree is too large (maximum depth %d)", mxHeight
669 );
670 rc = SQLITE_ERROR;
671 }
672 return rc;
673 }
674
675 /* The following three functions, heightOfExpr(), heightOfExprList()
676 ** and heightOfSelect(), are used to determine the maximum height
677 ** of any expression tree referenced by the structure passed as the
678 ** first argument.
679 **
680 ** If this maximum height is greater than the current value pointed
681 ** to by pnHeight, the second parameter, then set *pnHeight to that
682 ** value.
683 */
heightOfExpr(Expr * p,int * pnHeight)684 static void heightOfExpr(Expr *p, int *pnHeight){
685 if( p ){
686 if( p->nHeight>*pnHeight ){
687 *pnHeight = p->nHeight;
688 }
689 }
690 }
heightOfExprList(ExprList * p,int * pnHeight)691 static void heightOfExprList(ExprList *p, int *pnHeight){
692 if( p ){
693 int i;
694 for(i=0; i<p->nExpr; i++){
695 heightOfExpr(p->a[i].pExpr, pnHeight);
696 }
697 }
698 }
heightOfSelect(Select * pSelect,int * pnHeight)699 static void heightOfSelect(Select *pSelect, int *pnHeight){
700 Select *p;
701 for(p=pSelect; p; p=p->pPrior){
702 heightOfExpr(p->pWhere, pnHeight);
703 heightOfExpr(p->pHaving, pnHeight);
704 heightOfExpr(p->pLimit, pnHeight);
705 heightOfExprList(p->pEList, pnHeight);
706 heightOfExprList(p->pGroupBy, pnHeight);
707 heightOfExprList(p->pOrderBy, pnHeight);
708 }
709 }
710
711 /*
712 ** Set the Expr.nHeight variable in the structure passed as an
713 ** argument. An expression with no children, Expr.pList or
714 ** Expr.pSelect member has a height of 1. Any other expression
715 ** has a height equal to the maximum height of any other
716 ** referenced Expr plus one.
717 **
718 ** Also propagate EP_Propagate flags up from Expr.x.pList to Expr.flags,
719 ** if appropriate.
720 */
exprSetHeight(Expr * p)721 static void exprSetHeight(Expr *p){
722 int nHeight = 0;
723 heightOfExpr(p->pLeft, &nHeight);
724 heightOfExpr(p->pRight, &nHeight);
725 if( ExprHasProperty(p, EP_xIsSelect) ){
726 heightOfSelect(p->x.pSelect, &nHeight);
727 }else if( p->x.pList ){
728 heightOfExprList(p->x.pList, &nHeight);
729 p->flags |= EP_Propagate & sqlite3ExprListFlags(p->x.pList);
730 }
731 p->nHeight = nHeight + 1;
732 }
733
734 /*
735 ** Set the Expr.nHeight variable using the exprSetHeight() function. If
736 ** the height is greater than the maximum allowed expression depth,
737 ** leave an error in pParse.
738 **
739 ** Also propagate all EP_Propagate flags from the Expr.x.pList into
740 ** Expr.flags.
741 */
sqlite3ExprSetHeightAndFlags(Parse * pParse,Expr * p)742 void sqlite3ExprSetHeightAndFlags(Parse *pParse, Expr *p){
743 if( pParse->nErr ) return;
744 exprSetHeight(p);
745 sqlite3ExprCheckHeight(pParse, p->nHeight);
746 }
747
748 /*
749 ** Return the maximum height of any expression tree referenced
750 ** by the select statement passed as an argument.
751 */
sqlite3SelectExprHeight(Select * p)752 int sqlite3SelectExprHeight(Select *p){
753 int nHeight = 0;
754 heightOfSelect(p, &nHeight);
755 return nHeight;
756 }
757 #else /* ABOVE: Height enforcement enabled. BELOW: Height enforcement off */
758 /*
759 ** Propagate all EP_Propagate flags from the Expr.x.pList into
760 ** Expr.flags.
761 */
sqlite3ExprSetHeightAndFlags(Parse * pParse,Expr * p)762 void sqlite3ExprSetHeightAndFlags(Parse *pParse, Expr *p){
763 if( p && p->x.pList && !ExprHasProperty(p, EP_xIsSelect) ){
764 p->flags |= EP_Propagate & sqlite3ExprListFlags(p->x.pList);
765 }
766 }
767 #define exprSetHeight(y)
768 #endif /* SQLITE_MAX_EXPR_DEPTH>0 */
769
770 /*
771 ** This routine is the core allocator for Expr nodes.
772 **
773 ** Construct a new expression node and return a pointer to it. Memory
774 ** for this node and for the pToken argument is a single allocation
775 ** obtained from sqlite3DbMalloc(). The calling function
776 ** is responsible for making sure the node eventually gets freed.
777 **
778 ** If dequote is true, then the token (if it exists) is dequoted.
779 ** If dequote is false, no dequoting is performed. The deQuote
780 ** parameter is ignored if pToken is NULL or if the token does not
781 ** appear to be quoted. If the quotes were of the form "..." (double-quotes)
782 ** then the EP_DblQuoted flag is set on the expression node.
783 **
784 ** Special case: If op==TK_INTEGER and pToken points to a string that
785 ** can be translated into a 32-bit integer, then the token is not
786 ** stored in u.zToken. Instead, the integer values is written
787 ** into u.iValue and the EP_IntValue flag is set. No extra storage
788 ** is allocated to hold the integer text and the dequote flag is ignored.
789 */
sqlite3ExprAlloc(sqlite3 * db,int op,const Token * pToken,int dequote)790 Expr *sqlite3ExprAlloc(
791 sqlite3 *db, /* Handle for sqlite3DbMallocRawNN() */
792 int op, /* Expression opcode */
793 const Token *pToken, /* Token argument. Might be NULL */
794 int dequote /* True to dequote */
795 ){
796 Expr *pNew;
797 int nExtra = 0;
798 int iValue = 0;
799
800 assert( db!=0 );
801 if( pToken ){
802 if( op!=TK_INTEGER || pToken->z==0
803 || sqlite3GetInt32(pToken->z, &iValue)==0 ){
804 nExtra = pToken->n+1;
805 assert( iValue>=0 );
806 }
807 }
808 pNew = sqlite3DbMallocRawNN(db, sizeof(Expr)+nExtra);
809 if( pNew ){
810 memset(pNew, 0, sizeof(Expr));
811 pNew->op = (u8)op;
812 pNew->iAgg = -1;
813 if( pToken ){
814 if( nExtra==0 ){
815 pNew->flags |= EP_IntValue|EP_Leaf|(iValue?EP_IsTrue:EP_IsFalse);
816 pNew->u.iValue = iValue;
817 }else{
818 pNew->u.zToken = (char*)&pNew[1];
819 assert( pToken->z!=0 || pToken->n==0 );
820 if( pToken->n ) memcpy(pNew->u.zToken, pToken->z, pToken->n);
821 pNew->u.zToken[pToken->n] = 0;
822 if( dequote && sqlite3Isquote(pNew->u.zToken[0]) ){
823 sqlite3DequoteExpr(pNew);
824 }
825 }
826 }
827 #if SQLITE_MAX_EXPR_DEPTH>0
828 pNew->nHeight = 1;
829 #endif
830 }
831 return pNew;
832 }
833
834 /*
835 ** Allocate a new expression node from a zero-terminated token that has
836 ** already been dequoted.
837 */
sqlite3Expr(sqlite3 * db,int op,const char * zToken)838 Expr *sqlite3Expr(
839 sqlite3 *db, /* Handle for sqlite3DbMallocZero() (may be null) */
840 int op, /* Expression opcode */
841 const char *zToken /* Token argument. Might be NULL */
842 ){
843 Token x;
844 x.z = zToken;
845 x.n = sqlite3Strlen30(zToken);
846 return sqlite3ExprAlloc(db, op, &x, 0);
847 }
848
849 /*
850 ** Attach subtrees pLeft and pRight to the Expr node pRoot.
851 **
852 ** If pRoot==NULL that means that a memory allocation error has occurred.
853 ** In that case, delete the subtrees pLeft and pRight.
854 */
sqlite3ExprAttachSubtrees(sqlite3 * db,Expr * pRoot,Expr * pLeft,Expr * pRight)855 void sqlite3ExprAttachSubtrees(
856 sqlite3 *db,
857 Expr *pRoot,
858 Expr *pLeft,
859 Expr *pRight
860 ){
861 if( pRoot==0 ){
862 assert( db->mallocFailed );
863 sqlite3ExprDelete(db, pLeft);
864 sqlite3ExprDelete(db, pRight);
865 }else{
866 if( pRight ){
867 pRoot->pRight = pRight;
868 pRoot->flags |= EP_Propagate & pRight->flags;
869 }
870 if( pLeft ){
871 pRoot->pLeft = pLeft;
872 pRoot->flags |= EP_Propagate & pLeft->flags;
873 }
874 exprSetHeight(pRoot);
875 }
876 }
877
878 /*
879 ** Allocate an Expr node which joins as many as two subtrees.
880 **
881 ** One or both of the subtrees can be NULL. Return a pointer to the new
882 ** Expr node. Or, if an OOM error occurs, set pParse->db->mallocFailed,
883 ** free the subtrees and return NULL.
884 */
sqlite3PExpr(Parse * pParse,int op,Expr * pLeft,Expr * pRight)885 Expr *sqlite3PExpr(
886 Parse *pParse, /* Parsing context */
887 int op, /* Expression opcode */
888 Expr *pLeft, /* Left operand */
889 Expr *pRight /* Right operand */
890 ){
891 Expr *p;
892 p = sqlite3DbMallocRawNN(pParse->db, sizeof(Expr));
893 if( p ){
894 memset(p, 0, sizeof(Expr));
895 p->op = op & 0xff;
896 p->iAgg = -1;
897 sqlite3ExprAttachSubtrees(pParse->db, p, pLeft, pRight);
898 sqlite3ExprCheckHeight(pParse, p->nHeight);
899 }else{
900 sqlite3ExprDelete(pParse->db, pLeft);
901 sqlite3ExprDelete(pParse->db, pRight);
902 }
903 return p;
904 }
905
906 /*
907 ** Add pSelect to the Expr.x.pSelect field. Or, if pExpr is NULL (due
908 ** do a memory allocation failure) then delete the pSelect object.
909 */
sqlite3PExprAddSelect(Parse * pParse,Expr * pExpr,Select * pSelect)910 void sqlite3PExprAddSelect(Parse *pParse, Expr *pExpr, Select *pSelect){
911 if( pExpr ){
912 pExpr->x.pSelect = pSelect;
913 ExprSetProperty(pExpr, EP_xIsSelect|EP_Subquery);
914 sqlite3ExprSetHeightAndFlags(pParse, pExpr);
915 }else{
916 assert( pParse->db->mallocFailed );
917 sqlite3SelectDelete(pParse->db, pSelect);
918 }
919 }
920
921
922 /*
923 ** Join two expressions using an AND operator. If either expression is
924 ** NULL, then just return the other expression.
925 **
926 ** If one side or the other of the AND is known to be false, then instead
927 ** of returning an AND expression, just return a constant expression with
928 ** a value of false.
929 */
sqlite3ExprAnd(Parse * pParse,Expr * pLeft,Expr * pRight)930 Expr *sqlite3ExprAnd(Parse *pParse, Expr *pLeft, Expr *pRight){
931 sqlite3 *db = pParse->db;
932 if( pLeft==0 ){
933 return pRight;
934 }else if( pRight==0 ){
935 return pLeft;
936 }else if( (ExprAlwaysFalse(pLeft) || ExprAlwaysFalse(pRight))
937 && !IN_RENAME_OBJECT
938 ){
939 sqlite3ExprDelete(db, pLeft);
940 sqlite3ExprDelete(db, pRight);
941 return sqlite3Expr(db, TK_INTEGER, "0");
942 }else{
943 return sqlite3PExpr(pParse, TK_AND, pLeft, pRight);
944 }
945 }
946
947 /*
948 ** Construct a new expression node for a function with multiple
949 ** arguments.
950 */
sqlite3ExprFunction(Parse * pParse,ExprList * pList,Token * pToken,int eDistinct)951 Expr *sqlite3ExprFunction(
952 Parse *pParse, /* Parsing context */
953 ExprList *pList, /* Argument list */
954 Token *pToken, /* Name of the function */
955 int eDistinct /* SF_Distinct or SF_ALL or 0 */
956 ){
957 Expr *pNew;
958 sqlite3 *db = pParse->db;
959 assert( pToken );
960 pNew = sqlite3ExprAlloc(db, TK_FUNCTION, pToken, 1);
961 if( pNew==0 ){
962 sqlite3ExprListDelete(db, pList); /* Avoid memory leak when malloc fails */
963 return 0;
964 }
965 if( pList && pList->nExpr > pParse->db->aLimit[SQLITE_LIMIT_FUNCTION_ARG] ){
966 sqlite3ErrorMsg(pParse, "too many arguments on function %T", pToken);
967 }
968 pNew->x.pList = pList;
969 ExprSetProperty(pNew, EP_HasFunc);
970 assert( !ExprHasProperty(pNew, EP_xIsSelect) );
971 sqlite3ExprSetHeightAndFlags(pParse, pNew);
972 if( eDistinct==SF_Distinct ) ExprSetProperty(pNew, EP_Distinct);
973 return pNew;
974 }
975
976 /*
977 ** Check to see if a function is usable according to current access
978 ** rules:
979 **
980 ** SQLITE_FUNC_DIRECT - Only usable from top-level SQL
981 **
982 ** SQLITE_FUNC_UNSAFE - Usable if TRUSTED_SCHEMA or from
983 ** top-level SQL
984 **
985 ** If the function is not usable, create an error.
986 */
sqlite3ExprFunctionUsable(Parse * pParse,Expr * pExpr,FuncDef * pDef)987 void sqlite3ExprFunctionUsable(
988 Parse *pParse, /* Parsing and code generating context */
989 Expr *pExpr, /* The function invocation */
990 FuncDef *pDef /* The function being invoked */
991 ){
992 assert( !IN_RENAME_OBJECT );
993 assert( (pDef->funcFlags & (SQLITE_FUNC_DIRECT|SQLITE_FUNC_UNSAFE))!=0 );
994 if( ExprHasProperty(pExpr, EP_FromDDL) ){
995 if( (pDef->funcFlags & SQLITE_FUNC_DIRECT)!=0
996 || (pParse->db->flags & SQLITE_TrustedSchema)==0
997 ){
998 /* Functions prohibited in triggers and views if:
999 ** (1) tagged with SQLITE_DIRECTONLY
1000 ** (2) not tagged with SQLITE_INNOCUOUS (which means it
1001 ** is tagged with SQLITE_FUNC_UNSAFE) and
1002 ** SQLITE_DBCONFIG_TRUSTED_SCHEMA is off (meaning
1003 ** that the schema is possibly tainted).
1004 */
1005 sqlite3ErrorMsg(pParse, "unsafe use of %s()", pDef->zName);
1006 }
1007 }
1008 }
1009
1010 /*
1011 ** Assign a variable number to an expression that encodes a wildcard
1012 ** in the original SQL statement.
1013 **
1014 ** Wildcards consisting of a single "?" are assigned the next sequential
1015 ** variable number.
1016 **
1017 ** Wildcards of the form "?nnn" are assigned the number "nnn". We make
1018 ** sure "nnn" is not too big to avoid a denial of service attack when
1019 ** the SQL statement comes from an external source.
1020 **
1021 ** Wildcards of the form ":aaa", "@aaa", or "$aaa" are assigned the same number
1022 ** as the previous instance of the same wildcard. Or if this is the first
1023 ** instance of the wildcard, the next sequential variable number is
1024 ** assigned.
1025 */
sqlite3ExprAssignVarNumber(Parse * pParse,Expr * pExpr,u32 n)1026 void sqlite3ExprAssignVarNumber(Parse *pParse, Expr *pExpr, u32 n){
1027 sqlite3 *db = pParse->db;
1028 const char *z;
1029 ynVar x;
1030
1031 if( pExpr==0 ) return;
1032 assert( !ExprHasProperty(pExpr, EP_IntValue|EP_Reduced|EP_TokenOnly) );
1033 z = pExpr->u.zToken;
1034 assert( z!=0 );
1035 assert( z[0]!=0 );
1036 assert( n==(u32)sqlite3Strlen30(z) );
1037 if( z[1]==0 ){
1038 /* Wildcard of the form "?". Assign the next variable number */
1039 assert( z[0]=='?' );
1040 x = (ynVar)(++pParse->nVar);
1041 }else{
1042 int doAdd = 0;
1043 if( z[0]=='?' ){
1044 /* Wildcard of the form "?nnn". Convert "nnn" to an integer and
1045 ** use it as the variable number */
1046 i64 i;
1047 int bOk;
1048 if( n==2 ){ /*OPTIMIZATION-IF-TRUE*/
1049 i = z[1]-'0'; /* The common case of ?N for a single digit N */
1050 bOk = 1;
1051 }else{
1052 bOk = 0==sqlite3Atoi64(&z[1], &i, n-1, SQLITE_UTF8);
1053 }
1054 testcase( i==0 );
1055 testcase( i==1 );
1056 testcase( i==db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER]-1 );
1057 testcase( i==db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER] );
1058 if( bOk==0 || i<1 || i>db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER] ){
1059 sqlite3ErrorMsg(pParse, "variable number must be between ?1 and ?%d",
1060 db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER]);
1061 return;
1062 }
1063 x = (ynVar)i;
1064 if( x>pParse->nVar ){
1065 pParse->nVar = (int)x;
1066 doAdd = 1;
1067 }else if( sqlite3VListNumToName(pParse->pVList, x)==0 ){
1068 doAdd = 1;
1069 }
1070 }else{
1071 /* Wildcards like ":aaa", "$aaa" or "@aaa". Reuse the same variable
1072 ** number as the prior appearance of the same name, or if the name
1073 ** has never appeared before, reuse the same variable number
1074 */
1075 x = (ynVar)sqlite3VListNameToNum(pParse->pVList, z, n);
1076 if( x==0 ){
1077 x = (ynVar)(++pParse->nVar);
1078 doAdd = 1;
1079 }
1080 }
1081 if( doAdd ){
1082 pParse->pVList = sqlite3VListAdd(db, pParse->pVList, z, n, x);
1083 }
1084 }
1085 pExpr->iColumn = x;
1086 if( x>db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER] ){
1087 sqlite3ErrorMsg(pParse, "too many SQL variables");
1088 }
1089 }
1090
1091 /*
1092 ** Recursively delete an expression tree.
1093 */
sqlite3ExprDeleteNN(sqlite3 * db,Expr * p)1094 static SQLITE_NOINLINE void sqlite3ExprDeleteNN(sqlite3 *db, Expr *p){
1095 assert( p!=0 );
1096 /* Sanity check: Assert that the IntValue is non-negative if it exists */
1097 assert( !ExprHasProperty(p, EP_IntValue) || p->u.iValue>=0 );
1098
1099 assert( !ExprHasProperty(p, EP_WinFunc) || p->y.pWin!=0 || db->mallocFailed );
1100 assert( p->op!=TK_FUNCTION || ExprHasProperty(p, EP_TokenOnly|EP_Reduced)
1101 || p->y.pWin==0 || ExprHasProperty(p, EP_WinFunc) );
1102 #ifdef SQLITE_DEBUG
1103 if( ExprHasProperty(p, EP_Leaf) && !ExprHasProperty(p, EP_TokenOnly) ){
1104 assert( p->pLeft==0 );
1105 assert( p->pRight==0 );
1106 assert( p->x.pSelect==0 );
1107 }
1108 #endif
1109 if( !ExprHasProperty(p, (EP_TokenOnly|EP_Leaf)) ){
1110 /* The Expr.x union is never used at the same time as Expr.pRight */
1111 assert( p->x.pList==0 || p->pRight==0 );
1112 if( p->pLeft && p->op!=TK_SELECT_COLUMN ) sqlite3ExprDeleteNN(db, p->pLeft);
1113 if( p->pRight ){
1114 assert( !ExprHasProperty(p, EP_WinFunc) );
1115 sqlite3ExprDeleteNN(db, p->pRight);
1116 }else if( ExprHasProperty(p, EP_xIsSelect) ){
1117 assert( !ExprHasProperty(p, EP_WinFunc) );
1118 sqlite3SelectDelete(db, p->x.pSelect);
1119 }else{
1120 sqlite3ExprListDelete(db, p->x.pList);
1121 #ifndef SQLITE_OMIT_WINDOWFUNC
1122 if( ExprHasProperty(p, EP_WinFunc) ){
1123 sqlite3WindowDelete(db, p->y.pWin);
1124 }
1125 #endif
1126 }
1127 }
1128 if( ExprHasProperty(p, EP_MemToken) ) sqlite3DbFree(db, p->u.zToken);
1129 if( !ExprHasProperty(p, EP_Static) ){
1130 sqlite3DbFreeNN(db, p);
1131 }
1132 }
sqlite3ExprDelete(sqlite3 * db,Expr * p)1133 void sqlite3ExprDelete(sqlite3 *db, Expr *p){
1134 if( p ) sqlite3ExprDeleteNN(db, p);
1135 }
1136
1137 /* Invoke sqlite3RenameExprUnmap() and sqlite3ExprDelete() on the
1138 ** expression.
1139 */
sqlite3ExprUnmapAndDelete(Parse * pParse,Expr * p)1140 void sqlite3ExprUnmapAndDelete(Parse *pParse, Expr *p){
1141 if( p ){
1142 if( IN_RENAME_OBJECT ){
1143 sqlite3RenameExprUnmap(pParse, p);
1144 }
1145 sqlite3ExprDeleteNN(pParse->db, p);
1146 }
1147 }
1148
1149 /*
1150 ** Return the number of bytes allocated for the expression structure
1151 ** passed as the first argument. This is always one of EXPR_FULLSIZE,
1152 ** EXPR_REDUCEDSIZE or EXPR_TOKENONLYSIZE.
1153 */
exprStructSize(Expr * p)1154 static int exprStructSize(Expr *p){
1155 if( ExprHasProperty(p, EP_TokenOnly) ) return EXPR_TOKENONLYSIZE;
1156 if( ExprHasProperty(p, EP_Reduced) ) return EXPR_REDUCEDSIZE;
1157 return EXPR_FULLSIZE;
1158 }
1159
1160 /*
1161 ** The dupedExpr*Size() routines each return the number of bytes required
1162 ** to store a copy of an expression or expression tree. They differ in
1163 ** how much of the tree is measured.
1164 **
1165 ** dupedExprStructSize() Size of only the Expr structure
1166 ** dupedExprNodeSize() Size of Expr + space for token
1167 ** dupedExprSize() Expr + token + subtree components
1168 **
1169 ***************************************************************************
1170 **
1171 ** The dupedExprStructSize() function returns two values OR-ed together:
1172 ** (1) the space required for a copy of the Expr structure only and
1173 ** (2) the EP_xxx flags that indicate what the structure size should be.
1174 ** The return values is always one of:
1175 **
1176 ** EXPR_FULLSIZE
1177 ** EXPR_REDUCEDSIZE | EP_Reduced
1178 ** EXPR_TOKENONLYSIZE | EP_TokenOnly
1179 **
1180 ** The size of the structure can be found by masking the return value
1181 ** of this routine with 0xfff. The flags can be found by masking the
1182 ** return value with EP_Reduced|EP_TokenOnly.
1183 **
1184 ** Note that with flags==EXPRDUP_REDUCE, this routines works on full-size
1185 ** (unreduced) Expr objects as they or originally constructed by the parser.
1186 ** During expression analysis, extra information is computed and moved into
1187 ** later parts of the Expr object and that extra information might get chopped
1188 ** off if the expression is reduced. Note also that it does not work to
1189 ** make an EXPRDUP_REDUCE copy of a reduced expression. It is only legal
1190 ** to reduce a pristine expression tree from the parser. The implementation
1191 ** of dupedExprStructSize() contain multiple assert() statements that attempt
1192 ** to enforce this constraint.
1193 */
dupedExprStructSize(Expr * p,int flags)1194 static int dupedExprStructSize(Expr *p, int flags){
1195 int nSize;
1196 assert( flags==EXPRDUP_REDUCE || flags==0 ); /* Only one flag value allowed */
1197 assert( EXPR_FULLSIZE<=0xfff );
1198 assert( (0xfff & (EP_Reduced|EP_TokenOnly))==0 );
1199 if( 0==flags || p->op==TK_SELECT_COLUMN
1200 #ifndef SQLITE_OMIT_WINDOWFUNC
1201 || ExprHasProperty(p, EP_WinFunc)
1202 #endif
1203 ){
1204 nSize = EXPR_FULLSIZE;
1205 }else{
1206 assert( !ExprHasProperty(p, EP_TokenOnly|EP_Reduced) );
1207 assert( !ExprHasProperty(p, EP_FromJoin) );
1208 assert( !ExprHasProperty(p, EP_MemToken) );
1209 assert( !ExprHasProperty(p, EP_NoReduce) );
1210 if( p->pLeft || p->x.pList ){
1211 nSize = EXPR_REDUCEDSIZE | EP_Reduced;
1212 }else{
1213 assert( p->pRight==0 );
1214 nSize = EXPR_TOKENONLYSIZE | EP_TokenOnly;
1215 }
1216 }
1217 return nSize;
1218 }
1219
1220 /*
1221 ** This function returns the space in bytes required to store the copy
1222 ** of the Expr structure and a copy of the Expr.u.zToken string (if that
1223 ** string is defined.)
1224 */
dupedExprNodeSize(Expr * p,int flags)1225 static int dupedExprNodeSize(Expr *p, int flags){
1226 int nByte = dupedExprStructSize(p, flags) & 0xfff;
1227 if( !ExprHasProperty(p, EP_IntValue) && p->u.zToken ){
1228 nByte += sqlite3Strlen30NN(p->u.zToken)+1;
1229 }
1230 return ROUND8(nByte);
1231 }
1232
1233 /*
1234 ** Return the number of bytes required to create a duplicate of the
1235 ** expression passed as the first argument. The second argument is a
1236 ** mask containing EXPRDUP_XXX flags.
1237 **
1238 ** The value returned includes space to create a copy of the Expr struct
1239 ** itself and the buffer referred to by Expr.u.zToken, if any.
1240 **
1241 ** If the EXPRDUP_REDUCE flag is set, then the return value includes
1242 ** space to duplicate all Expr nodes in the tree formed by Expr.pLeft
1243 ** and Expr.pRight variables (but not for any structures pointed to or
1244 ** descended from the Expr.x.pList or Expr.x.pSelect variables).
1245 */
dupedExprSize(Expr * p,int flags)1246 static int dupedExprSize(Expr *p, int flags){
1247 int nByte = 0;
1248 if( p ){
1249 nByte = dupedExprNodeSize(p, flags);
1250 if( flags&EXPRDUP_REDUCE ){
1251 nByte += dupedExprSize(p->pLeft, flags) + dupedExprSize(p->pRight, flags);
1252 }
1253 }
1254 return nByte;
1255 }
1256
1257 /*
1258 ** This function is similar to sqlite3ExprDup(), except that if pzBuffer
1259 ** is not NULL then *pzBuffer is assumed to point to a buffer large enough
1260 ** to store the copy of expression p, the copies of p->u.zToken
1261 ** (if applicable), and the copies of the p->pLeft and p->pRight expressions,
1262 ** if any. Before returning, *pzBuffer is set to the first byte past the
1263 ** portion of the buffer copied into by this function.
1264 */
exprDup(sqlite3 * db,Expr * p,int dupFlags,u8 ** pzBuffer)1265 static Expr *exprDup(sqlite3 *db, Expr *p, int dupFlags, u8 **pzBuffer){
1266 Expr *pNew; /* Value to return */
1267 u8 *zAlloc; /* Memory space from which to build Expr object */
1268 u32 staticFlag; /* EP_Static if space not obtained from malloc */
1269
1270 assert( db!=0 );
1271 assert( p );
1272 assert( dupFlags==0 || dupFlags==EXPRDUP_REDUCE );
1273 assert( pzBuffer==0 || dupFlags==EXPRDUP_REDUCE );
1274
1275 /* Figure out where to write the new Expr structure. */
1276 if( pzBuffer ){
1277 zAlloc = *pzBuffer;
1278 staticFlag = EP_Static;
1279 }else{
1280 zAlloc = sqlite3DbMallocRawNN(db, dupedExprSize(p, dupFlags));
1281 staticFlag = 0;
1282 }
1283 pNew = (Expr *)zAlloc;
1284
1285 if( pNew ){
1286 /* Set nNewSize to the size allocated for the structure pointed to
1287 ** by pNew. This is either EXPR_FULLSIZE, EXPR_REDUCEDSIZE or
1288 ** EXPR_TOKENONLYSIZE. nToken is set to the number of bytes consumed
1289 ** by the copy of the p->u.zToken string (if any).
1290 */
1291 const unsigned nStructSize = dupedExprStructSize(p, dupFlags);
1292 const int nNewSize = nStructSize & 0xfff;
1293 int nToken;
1294 if( !ExprHasProperty(p, EP_IntValue) && p->u.zToken ){
1295 nToken = sqlite3Strlen30(p->u.zToken) + 1;
1296 }else{
1297 nToken = 0;
1298 }
1299 if( dupFlags ){
1300 assert( ExprHasProperty(p, EP_Reduced)==0 );
1301 memcpy(zAlloc, p, nNewSize);
1302 }else{
1303 u32 nSize = (u32)exprStructSize(p);
1304 memcpy(zAlloc, p, nSize);
1305 if( nSize<EXPR_FULLSIZE ){
1306 memset(&zAlloc[nSize], 0, EXPR_FULLSIZE-nSize);
1307 }
1308 }
1309
1310 /* Set the EP_Reduced, EP_TokenOnly, and EP_Static flags appropriately. */
1311 pNew->flags &= ~(EP_Reduced|EP_TokenOnly|EP_Static|EP_MemToken);
1312 pNew->flags |= nStructSize & (EP_Reduced|EP_TokenOnly);
1313 pNew->flags |= staticFlag;
1314
1315 /* Copy the p->u.zToken string, if any. */
1316 if( nToken ){
1317 char *zToken = pNew->u.zToken = (char*)&zAlloc[nNewSize];
1318 memcpy(zToken, p->u.zToken, nToken);
1319 }
1320
1321 if( 0==((p->flags|pNew->flags) & (EP_TokenOnly|EP_Leaf)) ){
1322 /* Fill in the pNew->x.pSelect or pNew->x.pList member. */
1323 if( ExprHasProperty(p, EP_xIsSelect) ){
1324 pNew->x.pSelect = sqlite3SelectDup(db, p->x.pSelect, dupFlags);
1325 }else{
1326 pNew->x.pList = sqlite3ExprListDup(db, p->x.pList, dupFlags);
1327 }
1328 }
1329
1330 /* Fill in pNew->pLeft and pNew->pRight. */
1331 if( ExprHasProperty(pNew, EP_Reduced|EP_TokenOnly|EP_WinFunc) ){
1332 zAlloc += dupedExprNodeSize(p, dupFlags);
1333 if( !ExprHasProperty(pNew, EP_TokenOnly|EP_Leaf) ){
1334 pNew->pLeft = p->pLeft ?
1335 exprDup(db, p->pLeft, EXPRDUP_REDUCE, &zAlloc) : 0;
1336 pNew->pRight = p->pRight ?
1337 exprDup(db, p->pRight, EXPRDUP_REDUCE, &zAlloc) : 0;
1338 }
1339 #ifndef SQLITE_OMIT_WINDOWFUNC
1340 if( ExprHasProperty(p, EP_WinFunc) ){
1341 pNew->y.pWin = sqlite3WindowDup(db, pNew, p->y.pWin);
1342 assert( ExprHasProperty(pNew, EP_WinFunc) );
1343 }
1344 #endif /* SQLITE_OMIT_WINDOWFUNC */
1345 if( pzBuffer ){
1346 *pzBuffer = zAlloc;
1347 }
1348 }else{
1349 if( !ExprHasProperty(p, EP_TokenOnly|EP_Leaf) ){
1350 if( pNew->op==TK_SELECT_COLUMN ){
1351 pNew->pLeft = p->pLeft;
1352 assert( p->iColumn==0 || p->pRight==0 );
1353 assert( p->pRight==0 || p->pRight==p->pLeft );
1354 }else{
1355 pNew->pLeft = sqlite3ExprDup(db, p->pLeft, 0);
1356 }
1357 pNew->pRight = sqlite3ExprDup(db, p->pRight, 0);
1358 }
1359 }
1360 }
1361 return pNew;
1362 }
1363
1364 /*
1365 ** Create and return a deep copy of the object passed as the second
1366 ** argument. If an OOM condition is encountered, NULL is returned
1367 ** and the db->mallocFailed flag set.
1368 */
1369 #ifndef SQLITE_OMIT_CTE
withDup(sqlite3 * db,With * p)1370 static With *withDup(sqlite3 *db, With *p){
1371 With *pRet = 0;
1372 if( p ){
1373 sqlite3_int64 nByte = sizeof(*p) + sizeof(p->a[0]) * (p->nCte-1);
1374 pRet = sqlite3DbMallocZero(db, nByte);
1375 if( pRet ){
1376 int i;
1377 pRet->nCte = p->nCte;
1378 for(i=0; i<p->nCte; i++){
1379 pRet->a[i].pSelect = sqlite3SelectDup(db, p->a[i].pSelect, 0);
1380 pRet->a[i].pCols = sqlite3ExprListDup(db, p->a[i].pCols, 0);
1381 pRet->a[i].zName = sqlite3DbStrDup(db, p->a[i].zName);
1382 }
1383 }
1384 }
1385 return pRet;
1386 }
1387 #else
1388 # define withDup(x,y) 0
1389 #endif
1390
1391 #ifndef SQLITE_OMIT_WINDOWFUNC
1392 /*
1393 ** The gatherSelectWindows() procedure and its helper routine
1394 ** gatherSelectWindowsCallback() are used to scan all the expressions
1395 ** an a newly duplicated SELECT statement and gather all of the Window
1396 ** objects found there, assembling them onto the linked list at Select->pWin.
1397 */
gatherSelectWindowsCallback(Walker * pWalker,Expr * pExpr)1398 static int gatherSelectWindowsCallback(Walker *pWalker, Expr *pExpr){
1399 if( pExpr->op==TK_FUNCTION && ExprHasProperty(pExpr, EP_WinFunc) ){
1400 Select *pSelect = pWalker->u.pSelect;
1401 Window *pWin = pExpr->y.pWin;
1402 assert( pWin );
1403 assert( IsWindowFunc(pExpr) );
1404 assert( pWin->ppThis==0 );
1405 sqlite3WindowLink(pSelect, pWin);
1406 }
1407 return WRC_Continue;
1408 }
gatherSelectWindowsSelectCallback(Walker * pWalker,Select * p)1409 static int gatherSelectWindowsSelectCallback(Walker *pWalker, Select *p){
1410 return p==pWalker->u.pSelect ? WRC_Continue : WRC_Prune;
1411 }
gatherSelectWindows(Select * p)1412 static void gatherSelectWindows(Select *p){
1413 Walker w;
1414 w.xExprCallback = gatherSelectWindowsCallback;
1415 w.xSelectCallback = gatherSelectWindowsSelectCallback;
1416 w.xSelectCallback2 = 0;
1417 w.pParse = 0;
1418 w.u.pSelect = p;
1419 sqlite3WalkSelect(&w, p);
1420 }
1421 #endif
1422
1423
1424 /*
1425 ** The following group of routines make deep copies of expressions,
1426 ** expression lists, ID lists, and select statements. The copies can
1427 ** be deleted (by being passed to their respective ...Delete() routines)
1428 ** without effecting the originals.
1429 **
1430 ** The expression list, ID, and source lists return by sqlite3ExprListDup(),
1431 ** sqlite3IdListDup(), and sqlite3SrcListDup() can not be further expanded
1432 ** by subsequent calls to sqlite*ListAppend() routines.
1433 **
1434 ** Any tables that the SrcList might point to are not duplicated.
1435 **
1436 ** The flags parameter contains a combination of the EXPRDUP_XXX flags.
1437 ** If the EXPRDUP_REDUCE flag is set, then the structure returned is a
1438 ** truncated version of the usual Expr structure that will be stored as
1439 ** part of the in-memory representation of the database schema.
1440 */
sqlite3ExprDup(sqlite3 * db,Expr * p,int flags)1441 Expr *sqlite3ExprDup(sqlite3 *db, Expr *p, int flags){
1442 assert( flags==0 || flags==EXPRDUP_REDUCE );
1443 return p ? exprDup(db, p, flags, 0) : 0;
1444 }
sqlite3ExprListDup(sqlite3 * db,ExprList * p,int flags)1445 ExprList *sqlite3ExprListDup(sqlite3 *db, ExprList *p, int flags){
1446 ExprList *pNew;
1447 struct ExprList_item *pItem, *pOldItem;
1448 int i;
1449 Expr *pPriorSelectCol = 0;
1450 assert( db!=0 );
1451 if( p==0 ) return 0;
1452 pNew = sqlite3DbMallocRawNN(db, sqlite3DbMallocSize(db, p));
1453 if( pNew==0 ) return 0;
1454 pNew->nExpr = p->nExpr;
1455 pItem = pNew->a;
1456 pOldItem = p->a;
1457 for(i=0; i<p->nExpr; i++, pItem++, pOldItem++){
1458 Expr *pOldExpr = pOldItem->pExpr;
1459 Expr *pNewExpr;
1460 pItem->pExpr = sqlite3ExprDup(db, pOldExpr, flags);
1461 if( pOldExpr
1462 && pOldExpr->op==TK_SELECT_COLUMN
1463 && (pNewExpr = pItem->pExpr)!=0
1464 ){
1465 assert( pNewExpr->iColumn==0 || i>0 );
1466 if( pNewExpr->iColumn==0 ){
1467 assert( pOldExpr->pLeft==pOldExpr->pRight );
1468 pPriorSelectCol = pNewExpr->pLeft = pNewExpr->pRight;
1469 }else{
1470 assert( i>0 );
1471 assert( pItem[-1].pExpr!=0 );
1472 assert( pNewExpr->iColumn==pItem[-1].pExpr->iColumn+1 );
1473 assert( pPriorSelectCol==pItem[-1].pExpr->pLeft );
1474 pNewExpr->pLeft = pPriorSelectCol;
1475 }
1476 }
1477 pItem->zEName = sqlite3DbStrDup(db, pOldItem->zEName);
1478 pItem->sortFlags = pOldItem->sortFlags;
1479 pItem->eEName = pOldItem->eEName;
1480 pItem->done = 0;
1481 pItem->bNulls = pOldItem->bNulls;
1482 pItem->bSorterRef = pOldItem->bSorterRef;
1483 pItem->u = pOldItem->u;
1484 }
1485 return pNew;
1486 }
1487
1488 /*
1489 ** If cursors, triggers, views and subqueries are all omitted from
1490 ** the build, then none of the following routines, except for
1491 ** sqlite3SelectDup(), can be called. sqlite3SelectDup() is sometimes
1492 ** called with a NULL argument.
1493 */
1494 #if !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_TRIGGER) \
1495 || !defined(SQLITE_OMIT_SUBQUERY)
sqlite3SrcListDup(sqlite3 * db,SrcList * p,int flags)1496 SrcList *sqlite3SrcListDup(sqlite3 *db, SrcList *p, int flags){
1497 SrcList *pNew;
1498 int i;
1499 int nByte;
1500 assert( db!=0 );
1501 if( p==0 ) return 0;
1502 nByte = sizeof(*p) + (p->nSrc>0 ? sizeof(p->a[0]) * (p->nSrc-1) : 0);
1503 pNew = sqlite3DbMallocRawNN(db, nByte );
1504 if( pNew==0 ) return 0;
1505 pNew->nSrc = pNew->nAlloc = p->nSrc;
1506 for(i=0; i<p->nSrc; i++){
1507 struct SrcList_item *pNewItem = &pNew->a[i];
1508 struct SrcList_item *pOldItem = &p->a[i];
1509 Table *pTab;
1510 pNewItem->pSchema = pOldItem->pSchema;
1511 pNewItem->zDatabase = sqlite3DbStrDup(db, pOldItem->zDatabase);
1512 pNewItem->zName = sqlite3DbStrDup(db, pOldItem->zName);
1513 pNewItem->zAlias = sqlite3DbStrDup(db, pOldItem->zAlias);
1514 pNewItem->fg = pOldItem->fg;
1515 pNewItem->iCursor = pOldItem->iCursor;
1516 pNewItem->addrFillSub = pOldItem->addrFillSub;
1517 pNewItem->regReturn = pOldItem->regReturn;
1518 if( pNewItem->fg.isIndexedBy ){
1519 pNewItem->u1.zIndexedBy = sqlite3DbStrDup(db, pOldItem->u1.zIndexedBy);
1520 }
1521 pNewItem->pIBIndex = pOldItem->pIBIndex;
1522 if( pNewItem->fg.isTabFunc ){
1523 pNewItem->u1.pFuncArg =
1524 sqlite3ExprListDup(db, pOldItem->u1.pFuncArg, flags);
1525 }
1526 pTab = pNewItem->pTab = pOldItem->pTab;
1527 if( pTab ){
1528 pTab->nTabRef++;
1529 }
1530 pNewItem->pSelect = sqlite3SelectDup(db, pOldItem->pSelect, flags);
1531 pNewItem->pOn = sqlite3ExprDup(db, pOldItem->pOn, flags);
1532 pNewItem->pUsing = sqlite3IdListDup(db, pOldItem->pUsing);
1533 pNewItem->colUsed = pOldItem->colUsed;
1534 }
1535 return pNew;
1536 }
sqlite3IdListDup(sqlite3 * db,IdList * p)1537 IdList *sqlite3IdListDup(sqlite3 *db, IdList *p){
1538 IdList *pNew;
1539 int i;
1540 assert( db!=0 );
1541 if( p==0 ) return 0;
1542 pNew = sqlite3DbMallocRawNN(db, sizeof(*pNew) );
1543 if( pNew==0 ) return 0;
1544 pNew->nId = p->nId;
1545 pNew->a = sqlite3DbMallocRawNN(db, p->nId*sizeof(p->a[0]) );
1546 if( pNew->a==0 ){
1547 sqlite3DbFreeNN(db, pNew);
1548 return 0;
1549 }
1550 /* Note that because the size of the allocation for p->a[] is not
1551 ** necessarily a power of two, sqlite3IdListAppend() may not be called
1552 ** on the duplicate created by this function. */
1553 for(i=0; i<p->nId; i++){
1554 struct IdList_item *pNewItem = &pNew->a[i];
1555 struct IdList_item *pOldItem = &p->a[i];
1556 pNewItem->zName = sqlite3DbStrDup(db, pOldItem->zName);
1557 pNewItem->idx = pOldItem->idx;
1558 }
1559 return pNew;
1560 }
sqlite3SelectDup(sqlite3 * db,Select * pDup,int flags)1561 Select *sqlite3SelectDup(sqlite3 *db, Select *pDup, int flags){
1562 Select *pRet = 0;
1563 Select *pNext = 0;
1564 Select **pp = &pRet;
1565 Select *p;
1566
1567 assert( db!=0 );
1568 for(p=pDup; p; p=p->pPrior){
1569 Select *pNew = sqlite3DbMallocRawNN(db, sizeof(*p) );
1570 if( pNew==0 ) break;
1571 pNew->pEList = sqlite3ExprListDup(db, p->pEList, flags);
1572 pNew->pSrc = sqlite3SrcListDup(db, p->pSrc, flags);
1573 pNew->pWhere = sqlite3ExprDup(db, p->pWhere, flags);
1574 pNew->pGroupBy = sqlite3ExprListDup(db, p->pGroupBy, flags);
1575 pNew->pHaving = sqlite3ExprDup(db, p->pHaving, flags);
1576 pNew->pOrderBy = sqlite3ExprListDup(db, p->pOrderBy, flags);
1577 pNew->op = p->op;
1578 pNew->pNext = pNext;
1579 pNew->pPrior = 0;
1580 pNew->pLimit = sqlite3ExprDup(db, p->pLimit, flags);
1581 pNew->iLimit = 0;
1582 pNew->iOffset = 0;
1583 pNew->selFlags = p->selFlags & ~SF_UsesEphemeral;
1584 pNew->addrOpenEphm[0] = -1;
1585 pNew->addrOpenEphm[1] = -1;
1586 pNew->nSelectRow = p->nSelectRow;
1587 pNew->pWith = withDup(db, p->pWith);
1588 #ifndef SQLITE_OMIT_WINDOWFUNC
1589 pNew->pWin = 0;
1590 pNew->pWinDefn = sqlite3WindowListDup(db, p->pWinDefn);
1591 if( p->pWin && db->mallocFailed==0 ) gatherSelectWindows(pNew);
1592 #endif
1593 pNew->selId = p->selId;
1594 *pp = pNew;
1595 pp = &pNew->pPrior;
1596 pNext = pNew;
1597 }
1598
1599 return pRet;
1600 }
1601 #else
sqlite3SelectDup(sqlite3 * db,Select * p,int flags)1602 Select *sqlite3SelectDup(sqlite3 *db, Select *p, int flags){
1603 assert( p==0 );
1604 return 0;
1605 }
1606 #endif
1607
1608
1609 /*
1610 ** Add a new element to the end of an expression list. If pList is
1611 ** initially NULL, then create a new expression list.
1612 **
1613 ** The pList argument must be either NULL or a pointer to an ExprList
1614 ** obtained from a prior call to sqlite3ExprListAppend(). This routine
1615 ** may not be used with an ExprList obtained from sqlite3ExprListDup().
1616 ** Reason: This routine assumes that the number of slots in pList->a[]
1617 ** is a power of two. That is true for sqlite3ExprListAppend() returns
1618 ** but is not necessarily true from the return value of sqlite3ExprListDup().
1619 **
1620 ** If a memory allocation error occurs, the entire list is freed and
1621 ** NULL is returned. If non-NULL is returned, then it is guaranteed
1622 ** that the new entry was successfully appended.
1623 */
sqlite3ExprListAppend(Parse * pParse,ExprList * pList,Expr * pExpr)1624 ExprList *sqlite3ExprListAppend(
1625 Parse *pParse, /* Parsing context */
1626 ExprList *pList, /* List to which to append. Might be NULL */
1627 Expr *pExpr /* Expression to be appended. Might be NULL */
1628 ){
1629 struct ExprList_item *pItem;
1630 sqlite3 *db = pParse->db;
1631 assert( db!=0 );
1632 if( pList==0 ){
1633 pList = sqlite3DbMallocRawNN(db, sizeof(ExprList) );
1634 if( pList==0 ){
1635 goto no_mem;
1636 }
1637 pList->nExpr = 0;
1638 }else if( (pList->nExpr & (pList->nExpr-1))==0 ){
1639 ExprList *pNew;
1640 pNew = sqlite3DbRealloc(db, pList,
1641 sizeof(*pList)+(2*(sqlite3_int64)pList->nExpr-1)*sizeof(pList->a[0]));
1642 if( pNew==0 ){
1643 goto no_mem;
1644 }
1645 pList = pNew;
1646 }
1647 pItem = &pList->a[pList->nExpr++];
1648 assert( offsetof(struct ExprList_item,zEName)==sizeof(pItem->pExpr) );
1649 assert( offsetof(struct ExprList_item,pExpr)==0 );
1650 memset(&pItem->zEName,0,sizeof(*pItem)-offsetof(struct ExprList_item,zEName));
1651 pItem->pExpr = pExpr;
1652 return pList;
1653
1654 no_mem:
1655 /* Avoid leaking memory if malloc has failed. */
1656 sqlite3ExprDelete(db, pExpr);
1657 sqlite3ExprListDelete(db, pList);
1658 return 0;
1659 }
1660
1661 /*
1662 ** pColumns and pExpr form a vector assignment which is part of the SET
1663 ** clause of an UPDATE statement. Like this:
1664 **
1665 ** (a,b,c) = (expr1,expr2,expr3)
1666 ** Or: (a,b,c) = (SELECT x,y,z FROM ....)
1667 **
1668 ** For each term of the vector assignment, append new entries to the
1669 ** expression list pList. In the case of a subquery on the RHS, append
1670 ** TK_SELECT_COLUMN expressions.
1671 */
sqlite3ExprListAppendVector(Parse * pParse,ExprList * pList,IdList * pColumns,Expr * pExpr)1672 ExprList *sqlite3ExprListAppendVector(
1673 Parse *pParse, /* Parsing context */
1674 ExprList *pList, /* List to which to append. Might be NULL */
1675 IdList *pColumns, /* List of names of LHS of the assignment */
1676 Expr *pExpr /* Vector expression to be appended. Might be NULL */
1677 ){
1678 sqlite3 *db = pParse->db;
1679 int n;
1680 int i;
1681 int iFirst = pList ? pList->nExpr : 0;
1682 /* pColumns can only be NULL due to an OOM but an OOM will cause an
1683 ** exit prior to this routine being invoked */
1684 if( NEVER(pColumns==0) ) goto vector_append_error;
1685 if( pExpr==0 ) goto vector_append_error;
1686
1687 /* If the RHS is a vector, then we can immediately check to see that
1688 ** the size of the RHS and LHS match. But if the RHS is a SELECT,
1689 ** wildcards ("*") in the result set of the SELECT must be expanded before
1690 ** we can do the size check, so defer the size check until code generation.
1691 */
1692 if( pExpr->op!=TK_SELECT && pColumns->nId!=(n=sqlite3ExprVectorSize(pExpr)) ){
1693 sqlite3ErrorMsg(pParse, "%d columns assigned %d values",
1694 pColumns->nId, n);
1695 goto vector_append_error;
1696 }
1697
1698 for(i=0; i<pColumns->nId; i++){
1699 Expr *pSubExpr = sqlite3ExprForVectorField(pParse, pExpr, i);
1700 assert( pSubExpr!=0 || db->mallocFailed );
1701 assert( pSubExpr==0 || pSubExpr->iTable==0 );
1702 if( pSubExpr==0 ) continue;
1703 pSubExpr->iTable = pColumns->nId;
1704 pList = sqlite3ExprListAppend(pParse, pList, pSubExpr);
1705 if( pList ){
1706 assert( pList->nExpr==iFirst+i+1 );
1707 pList->a[pList->nExpr-1].zEName = pColumns->a[i].zName;
1708 pColumns->a[i].zName = 0;
1709 }
1710 }
1711
1712 if( !db->mallocFailed && pExpr->op==TK_SELECT && ALWAYS(pList!=0) ){
1713 Expr *pFirst = pList->a[iFirst].pExpr;
1714 assert( pFirst!=0 );
1715 assert( pFirst->op==TK_SELECT_COLUMN );
1716
1717 /* Store the SELECT statement in pRight so it will be deleted when
1718 ** sqlite3ExprListDelete() is called */
1719 pFirst->pRight = pExpr;
1720 pExpr = 0;
1721
1722 /* Remember the size of the LHS in iTable so that we can check that
1723 ** the RHS and LHS sizes match during code generation. */
1724 pFirst->iTable = pColumns->nId;
1725 }
1726
1727 vector_append_error:
1728 sqlite3ExprUnmapAndDelete(pParse, pExpr);
1729 sqlite3IdListDelete(db, pColumns);
1730 return pList;
1731 }
1732
1733 /*
1734 ** Set the sort order for the last element on the given ExprList.
1735 */
sqlite3ExprListSetSortOrder(ExprList * p,int iSortOrder,int eNulls)1736 void sqlite3ExprListSetSortOrder(ExprList *p, int iSortOrder, int eNulls){
1737 struct ExprList_item *pItem;
1738 if( p==0 ) return;
1739 assert( p->nExpr>0 );
1740
1741 assert( SQLITE_SO_UNDEFINED<0 && SQLITE_SO_ASC==0 && SQLITE_SO_DESC>0 );
1742 assert( iSortOrder==SQLITE_SO_UNDEFINED
1743 || iSortOrder==SQLITE_SO_ASC
1744 || iSortOrder==SQLITE_SO_DESC
1745 );
1746 assert( eNulls==SQLITE_SO_UNDEFINED
1747 || eNulls==SQLITE_SO_ASC
1748 || eNulls==SQLITE_SO_DESC
1749 );
1750
1751 pItem = &p->a[p->nExpr-1];
1752 assert( pItem->bNulls==0 );
1753 if( iSortOrder==SQLITE_SO_UNDEFINED ){
1754 iSortOrder = SQLITE_SO_ASC;
1755 }
1756 pItem->sortFlags = (u8)iSortOrder;
1757
1758 if( eNulls!=SQLITE_SO_UNDEFINED ){
1759 pItem->bNulls = 1;
1760 if( iSortOrder!=eNulls ){
1761 pItem->sortFlags |= KEYINFO_ORDER_BIGNULL;
1762 }
1763 }
1764 }
1765
1766 /*
1767 ** Set the ExprList.a[].zEName element of the most recently added item
1768 ** on the expression list.
1769 **
1770 ** pList might be NULL following an OOM error. But pName should never be
1771 ** NULL. If a memory allocation fails, the pParse->db->mallocFailed flag
1772 ** is set.
1773 */
sqlite3ExprListSetName(Parse * pParse,ExprList * pList,Token * pName,int dequote)1774 void sqlite3ExprListSetName(
1775 Parse *pParse, /* Parsing context */
1776 ExprList *pList, /* List to which to add the span. */
1777 Token *pName, /* Name to be added */
1778 int dequote /* True to cause the name to be dequoted */
1779 ){
1780 assert( pList!=0 || pParse->db->mallocFailed!=0 );
1781 if( pList ){
1782 struct ExprList_item *pItem;
1783 assert( pList->nExpr>0 );
1784 pItem = &pList->a[pList->nExpr-1];
1785 assert( pItem->zEName==0 );
1786 assert( pItem->eEName==ENAME_NAME );
1787 pItem->zEName = sqlite3DbStrNDup(pParse->db, pName->z, pName->n);
1788 if( dequote ) sqlite3Dequote(pItem->zEName);
1789 if( IN_RENAME_OBJECT ){
1790 sqlite3RenameTokenMap(pParse, (void*)pItem->zEName, pName);
1791 }
1792 }
1793 }
1794
1795 /*
1796 ** Set the ExprList.a[].zSpan element of the most recently added item
1797 ** on the expression list.
1798 **
1799 ** pList might be NULL following an OOM error. But pSpan should never be
1800 ** NULL. If a memory allocation fails, the pParse->db->mallocFailed flag
1801 ** is set.
1802 */
sqlite3ExprListSetSpan(Parse * pParse,ExprList * pList,const char * zStart,const char * zEnd)1803 void sqlite3ExprListSetSpan(
1804 Parse *pParse, /* Parsing context */
1805 ExprList *pList, /* List to which to add the span. */
1806 const char *zStart, /* Start of the span */
1807 const char *zEnd /* End of the span */
1808 ){
1809 sqlite3 *db = pParse->db;
1810 assert( pList!=0 || db->mallocFailed!=0 );
1811 if( pList ){
1812 struct ExprList_item *pItem = &pList->a[pList->nExpr-1];
1813 assert( pList->nExpr>0 );
1814 if( pItem->zEName==0 ){
1815 pItem->zEName = sqlite3DbSpanDup(db, zStart, zEnd);
1816 pItem->eEName = ENAME_SPAN;
1817 }
1818 }
1819 }
1820
1821 /*
1822 ** If the expression list pEList contains more than iLimit elements,
1823 ** leave an error message in pParse.
1824 */
sqlite3ExprListCheckLength(Parse * pParse,ExprList * pEList,const char * zObject)1825 void sqlite3ExprListCheckLength(
1826 Parse *pParse,
1827 ExprList *pEList,
1828 const char *zObject
1829 ){
1830 int mx = pParse->db->aLimit[SQLITE_LIMIT_COLUMN];
1831 testcase( pEList && pEList->nExpr==mx );
1832 testcase( pEList && pEList->nExpr==mx+1 );
1833 if( pEList && pEList->nExpr>mx ){
1834 sqlite3ErrorMsg(pParse, "too many columns in %s", zObject);
1835 }
1836 }
1837
1838 /*
1839 ** Delete an entire expression list.
1840 */
exprListDeleteNN(sqlite3 * db,ExprList * pList)1841 static SQLITE_NOINLINE void exprListDeleteNN(sqlite3 *db, ExprList *pList){
1842 int i = pList->nExpr;
1843 struct ExprList_item *pItem = pList->a;
1844 assert( pList->nExpr>0 );
1845 do{
1846 sqlite3ExprDelete(db, pItem->pExpr);
1847 sqlite3DbFree(db, pItem->zEName);
1848 pItem++;
1849 }while( --i>0 );
1850 sqlite3DbFreeNN(db, pList);
1851 }
sqlite3ExprListDelete(sqlite3 * db,ExprList * pList)1852 void sqlite3ExprListDelete(sqlite3 *db, ExprList *pList){
1853 if( pList ) exprListDeleteNN(db, pList);
1854 }
1855
1856 /*
1857 ** Return the bitwise-OR of all Expr.flags fields in the given
1858 ** ExprList.
1859 */
sqlite3ExprListFlags(const ExprList * pList)1860 u32 sqlite3ExprListFlags(const ExprList *pList){
1861 int i;
1862 u32 m = 0;
1863 assert( pList!=0 );
1864 for(i=0; i<pList->nExpr; i++){
1865 Expr *pExpr = pList->a[i].pExpr;
1866 assert( pExpr!=0 );
1867 m |= pExpr->flags;
1868 }
1869 return m;
1870 }
1871
1872 /*
1873 ** This is a SELECT-node callback for the expression walker that
1874 ** always "fails". By "fail" in this case, we mean set
1875 ** pWalker->eCode to zero and abort.
1876 **
1877 ** This callback is used by multiple expression walkers.
1878 */
sqlite3SelectWalkFail(Walker * pWalker,Select * NotUsed)1879 int sqlite3SelectWalkFail(Walker *pWalker, Select *NotUsed){
1880 UNUSED_PARAMETER(NotUsed);
1881 pWalker->eCode = 0;
1882 return WRC_Abort;
1883 }
1884
1885 /*
1886 ** Check the input string to see if it is "true" or "false" (in any case).
1887 **
1888 ** If the string is.... Return
1889 ** "true" EP_IsTrue
1890 ** "false" EP_IsFalse
1891 ** anything else 0
1892 */
sqlite3IsTrueOrFalse(const char * zIn)1893 u32 sqlite3IsTrueOrFalse(const char *zIn){
1894 if( sqlite3StrICmp(zIn, "true")==0 ) return EP_IsTrue;
1895 if( sqlite3StrICmp(zIn, "false")==0 ) return EP_IsFalse;
1896 return 0;
1897 }
1898
1899
1900 /*
1901 ** If the input expression is an ID with the name "true" or "false"
1902 ** then convert it into an TK_TRUEFALSE term. Return non-zero if
1903 ** the conversion happened, and zero if the expression is unaltered.
1904 */
sqlite3ExprIdToTrueFalse(Expr * pExpr)1905 int sqlite3ExprIdToTrueFalse(Expr *pExpr){
1906 u32 v;
1907 assert( pExpr->op==TK_ID || pExpr->op==TK_STRING );
1908 if( !ExprHasProperty(pExpr, EP_Quoted)
1909 && (v = sqlite3IsTrueOrFalse(pExpr->u.zToken))!=0
1910 ){
1911 pExpr->op = TK_TRUEFALSE;
1912 ExprSetProperty(pExpr, v);
1913 return 1;
1914 }
1915 return 0;
1916 }
1917
1918 /*
1919 ** The argument must be a TK_TRUEFALSE Expr node. Return 1 if it is TRUE
1920 ** and 0 if it is FALSE.
1921 */
sqlite3ExprTruthValue(const Expr * pExpr)1922 int sqlite3ExprTruthValue(const Expr *pExpr){
1923 pExpr = sqlite3ExprSkipCollate((Expr*)pExpr);
1924 assert( pExpr->op==TK_TRUEFALSE );
1925 assert( sqlite3StrICmp(pExpr->u.zToken,"true")==0
1926 || sqlite3StrICmp(pExpr->u.zToken,"false")==0 );
1927 return pExpr->u.zToken[4]==0;
1928 }
1929
1930 /*
1931 ** If pExpr is an AND or OR expression, try to simplify it by eliminating
1932 ** terms that are always true or false. Return the simplified expression.
1933 ** Or return the original expression if no simplification is possible.
1934 **
1935 ** Examples:
1936 **
1937 ** (x<10) AND true => (x<10)
1938 ** (x<10) AND false => false
1939 ** (x<10) AND (y=22 OR false) => (x<10) AND (y=22)
1940 ** (x<10) AND (y=22 OR true) => (x<10)
1941 ** (y=22) OR true => true
1942 */
sqlite3ExprSimplifiedAndOr(Expr * pExpr)1943 Expr *sqlite3ExprSimplifiedAndOr(Expr *pExpr){
1944 assert( pExpr!=0 );
1945 if( pExpr->op==TK_AND || pExpr->op==TK_OR ){
1946 Expr *pRight = sqlite3ExprSimplifiedAndOr(pExpr->pRight);
1947 Expr *pLeft = sqlite3ExprSimplifiedAndOr(pExpr->pLeft);
1948 if( ExprAlwaysTrue(pLeft) || ExprAlwaysFalse(pRight) ){
1949 pExpr = pExpr->op==TK_AND ? pRight : pLeft;
1950 }else if( ExprAlwaysTrue(pRight) || ExprAlwaysFalse(pLeft) ){
1951 pExpr = pExpr->op==TK_AND ? pLeft : pRight;
1952 }
1953 }
1954 return pExpr;
1955 }
1956
1957
1958 /*
1959 ** These routines are Walker callbacks used to check expressions to
1960 ** see if they are "constant" for some definition of constant. The
1961 ** Walker.eCode value determines the type of "constant" we are looking
1962 ** for.
1963 **
1964 ** These callback routines are used to implement the following:
1965 **
1966 ** sqlite3ExprIsConstant() pWalker->eCode==1
1967 ** sqlite3ExprIsConstantNotJoin() pWalker->eCode==2
1968 ** sqlite3ExprIsTableConstant() pWalker->eCode==3
1969 ** sqlite3ExprIsConstantOrFunction() pWalker->eCode==4 or 5
1970 **
1971 ** In all cases, the callbacks set Walker.eCode=0 and abort if the expression
1972 ** is found to not be a constant.
1973 **
1974 ** The sqlite3ExprIsConstantOrFunction() is used for evaluating DEFAULT
1975 ** expressions in a CREATE TABLE statement. The Walker.eCode value is 5
1976 ** when parsing an existing schema out of the sqlite_master table and 4
1977 ** when processing a new CREATE TABLE statement. A bound parameter raises
1978 ** an error for new statements, but is silently converted
1979 ** to NULL for existing schemas. This allows sqlite_master tables that
1980 ** contain a bound parameter because they were generated by older versions
1981 ** of SQLite to be parsed by newer versions of SQLite without raising a
1982 ** malformed schema error.
1983 */
exprNodeIsConstant(Walker * pWalker,Expr * pExpr)1984 static int exprNodeIsConstant(Walker *pWalker, Expr *pExpr){
1985
1986 /* If pWalker->eCode is 2 then any term of the expression that comes from
1987 ** the ON or USING clauses of a left join disqualifies the expression
1988 ** from being considered constant. */
1989 if( pWalker->eCode==2 && ExprHasProperty(pExpr, EP_FromJoin) ){
1990 pWalker->eCode = 0;
1991 return WRC_Abort;
1992 }
1993
1994 switch( pExpr->op ){
1995 /* Consider functions to be constant if all their arguments are constant
1996 ** and either pWalker->eCode==4 or 5 or the function has the
1997 ** SQLITE_FUNC_CONST flag. */
1998 case TK_FUNCTION:
1999 if( (pWalker->eCode>=4 || ExprHasProperty(pExpr,EP_ConstFunc))
2000 && !ExprHasProperty(pExpr, EP_WinFunc)
2001 ){
2002 if( pWalker->eCode==5 ) ExprSetProperty(pExpr, EP_FromDDL);
2003 return WRC_Continue;
2004 }else{
2005 pWalker->eCode = 0;
2006 return WRC_Abort;
2007 }
2008 case TK_ID:
2009 /* Convert "true" or "false" in a DEFAULT clause into the
2010 ** appropriate TK_TRUEFALSE operator */
2011 if( sqlite3ExprIdToTrueFalse(pExpr) ){
2012 return WRC_Prune;
2013 }
2014 /* Fall thru */
2015 case TK_COLUMN:
2016 case TK_AGG_FUNCTION:
2017 case TK_AGG_COLUMN:
2018 testcase( pExpr->op==TK_ID );
2019 testcase( pExpr->op==TK_COLUMN );
2020 testcase( pExpr->op==TK_AGG_FUNCTION );
2021 testcase( pExpr->op==TK_AGG_COLUMN );
2022 if( ExprHasProperty(pExpr, EP_FixedCol) && pWalker->eCode!=2 ){
2023 return WRC_Continue;
2024 }
2025 if( pWalker->eCode==3 && pExpr->iTable==pWalker->u.iCur ){
2026 return WRC_Continue;
2027 }
2028 /* Fall through */
2029 case TK_IF_NULL_ROW:
2030 case TK_REGISTER:
2031 testcase( pExpr->op==TK_REGISTER );
2032 testcase( pExpr->op==TK_IF_NULL_ROW );
2033 pWalker->eCode = 0;
2034 return WRC_Abort;
2035 case TK_VARIABLE:
2036 if( pWalker->eCode==5 ){
2037 /* Silently convert bound parameters that appear inside of CREATE
2038 ** statements into a NULL when parsing the CREATE statement text out
2039 ** of the sqlite_master table */
2040 pExpr->op = TK_NULL;
2041 }else if( pWalker->eCode==4 ){
2042 /* A bound parameter in a CREATE statement that originates from
2043 ** sqlite3_prepare() causes an error */
2044 pWalker->eCode = 0;
2045 return WRC_Abort;
2046 }
2047 /* Fall through */
2048 default:
2049 testcase( pExpr->op==TK_SELECT ); /* sqlite3SelectWalkFail() disallows */
2050 testcase( pExpr->op==TK_EXISTS ); /* sqlite3SelectWalkFail() disallows */
2051 return WRC_Continue;
2052 }
2053 }
exprIsConst(Expr * p,int initFlag,int iCur)2054 static int exprIsConst(Expr *p, int initFlag, int iCur){
2055 Walker w;
2056 w.eCode = initFlag;
2057 w.xExprCallback = exprNodeIsConstant;
2058 w.xSelectCallback = sqlite3SelectWalkFail;
2059 #ifdef SQLITE_DEBUG
2060 w.xSelectCallback2 = sqlite3SelectWalkAssert2;
2061 #endif
2062 w.u.iCur = iCur;
2063 sqlite3WalkExpr(&w, p);
2064 return w.eCode;
2065 }
2066
2067 /*
2068 ** Walk an expression tree. Return non-zero if the expression is constant
2069 ** and 0 if it involves variables or function calls.
2070 **
2071 ** For the purposes of this function, a double-quoted string (ex: "abc")
2072 ** is considered a variable but a single-quoted string (ex: 'abc') is
2073 ** a constant.
2074 */
sqlite3ExprIsConstant(Expr * p)2075 int sqlite3ExprIsConstant(Expr *p){
2076 return exprIsConst(p, 1, 0);
2077 }
2078
2079 /*
2080 ** Walk an expression tree. Return non-zero if
2081 **
2082 ** (1) the expression is constant, and
2083 ** (2) the expression does originate in the ON or USING clause
2084 ** of a LEFT JOIN, and
2085 ** (3) the expression does not contain any EP_FixedCol TK_COLUMN
2086 ** operands created by the constant propagation optimization.
2087 **
2088 ** When this routine returns true, it indicates that the expression
2089 ** can be added to the pParse->pConstExpr list and evaluated once when
2090 ** the prepared statement starts up. See sqlite3ExprCodeAtInit().
2091 */
sqlite3ExprIsConstantNotJoin(Expr * p)2092 int sqlite3ExprIsConstantNotJoin(Expr *p){
2093 return exprIsConst(p, 2, 0);
2094 }
2095
2096 /*
2097 ** Walk an expression tree. Return non-zero if the expression is constant
2098 ** for any single row of the table with cursor iCur. In other words, the
2099 ** expression must not refer to any non-deterministic function nor any
2100 ** table other than iCur.
2101 */
sqlite3ExprIsTableConstant(Expr * p,int iCur)2102 int sqlite3ExprIsTableConstant(Expr *p, int iCur){
2103 return exprIsConst(p, 3, iCur);
2104 }
2105
2106
2107 /*
2108 ** sqlite3WalkExpr() callback used by sqlite3ExprIsConstantOrGroupBy().
2109 */
exprNodeIsConstantOrGroupBy(Walker * pWalker,Expr * pExpr)2110 static int exprNodeIsConstantOrGroupBy(Walker *pWalker, Expr *pExpr){
2111 ExprList *pGroupBy = pWalker->u.pGroupBy;
2112 int i;
2113
2114 /* Check if pExpr is identical to any GROUP BY term. If so, consider
2115 ** it constant. */
2116 for(i=0; i<pGroupBy->nExpr; i++){
2117 Expr *p = pGroupBy->a[i].pExpr;
2118 if( sqlite3ExprCompare(0, pExpr, p, -1)<2 ){
2119 CollSeq *pColl = sqlite3ExprNNCollSeq(pWalker->pParse, p);
2120 if( sqlite3IsBinary(pColl) ){
2121 return WRC_Prune;
2122 }
2123 }
2124 }
2125
2126 /* Check if pExpr is a sub-select. If so, consider it variable. */
2127 if( ExprHasProperty(pExpr, EP_xIsSelect) ){
2128 pWalker->eCode = 0;
2129 return WRC_Abort;
2130 }
2131
2132 return exprNodeIsConstant(pWalker, pExpr);
2133 }
2134
2135 /*
2136 ** Walk the expression tree passed as the first argument. Return non-zero
2137 ** if the expression consists entirely of constants or copies of terms
2138 ** in pGroupBy that sort with the BINARY collation sequence.
2139 **
2140 ** This routine is used to determine if a term of the HAVING clause can
2141 ** be promoted into the WHERE clause. In order for such a promotion to work,
2142 ** the value of the HAVING clause term must be the same for all members of
2143 ** a "group". The requirement that the GROUP BY term must be BINARY
2144 ** assumes that no other collating sequence will have a finer-grained
2145 ** grouping than binary. In other words (A=B COLLATE binary) implies
2146 ** A=B in every other collating sequence. The requirement that the
2147 ** GROUP BY be BINARY is stricter than necessary. It would also work
2148 ** to promote HAVING clauses that use the same alternative collating
2149 ** sequence as the GROUP BY term, but that is much harder to check,
2150 ** alternative collating sequences are uncommon, and this is only an
2151 ** optimization, so we take the easy way out and simply require the
2152 ** GROUP BY to use the BINARY collating sequence.
2153 */
sqlite3ExprIsConstantOrGroupBy(Parse * pParse,Expr * p,ExprList * pGroupBy)2154 int sqlite3ExprIsConstantOrGroupBy(Parse *pParse, Expr *p, ExprList *pGroupBy){
2155 Walker w;
2156 w.eCode = 1;
2157 w.xExprCallback = exprNodeIsConstantOrGroupBy;
2158 w.xSelectCallback = 0;
2159 w.u.pGroupBy = pGroupBy;
2160 w.pParse = pParse;
2161 sqlite3WalkExpr(&w, p);
2162 return w.eCode;
2163 }
2164
2165 /*
2166 ** Walk an expression tree for the DEFAULT field of a column definition
2167 ** in a CREATE TABLE statement. Return non-zero if the expression is
2168 ** acceptable for use as a DEFAULT. That is to say, return non-zero if
2169 ** the expression is constant or a function call with constant arguments.
2170 ** Return and 0 if there are any variables.
2171 **
2172 ** isInit is true when parsing from sqlite_master. isInit is false when
2173 ** processing a new CREATE TABLE statement. When isInit is true, parameters
2174 ** (such as ? or $abc) in the expression are converted into NULL. When
2175 ** isInit is false, parameters raise an error. Parameters should not be
2176 ** allowed in a CREATE TABLE statement, but some legacy versions of SQLite
2177 ** allowed it, so we need to support it when reading sqlite_master for
2178 ** backwards compatibility.
2179 **
2180 ** If isInit is true, set EP_FromDDL on every TK_FUNCTION node.
2181 **
2182 ** For the purposes of this function, a double-quoted string (ex: "abc")
2183 ** is considered a variable but a single-quoted string (ex: 'abc') is
2184 ** a constant.
2185 */
sqlite3ExprIsConstantOrFunction(Expr * p,u8 isInit)2186 int sqlite3ExprIsConstantOrFunction(Expr *p, u8 isInit){
2187 assert( isInit==0 || isInit==1 );
2188 return exprIsConst(p, 4+isInit, 0);
2189 }
2190
2191 #ifdef SQLITE_ENABLE_CURSOR_HINTS
2192 /*
2193 ** Walk an expression tree. Return 1 if the expression contains a
2194 ** subquery of some kind. Return 0 if there are no subqueries.
2195 */
sqlite3ExprContainsSubquery(Expr * p)2196 int sqlite3ExprContainsSubquery(Expr *p){
2197 Walker w;
2198 w.eCode = 1;
2199 w.xExprCallback = sqlite3ExprWalkNoop;
2200 w.xSelectCallback = sqlite3SelectWalkFail;
2201 #ifdef SQLITE_DEBUG
2202 w.xSelectCallback2 = sqlite3SelectWalkAssert2;
2203 #endif
2204 sqlite3WalkExpr(&w, p);
2205 return w.eCode==0;
2206 }
2207 #endif
2208
2209 /*
2210 ** If the expression p codes a constant integer that is small enough
2211 ** to fit in a 32-bit integer, return 1 and put the value of the integer
2212 ** in *pValue. If the expression is not an integer or if it is too big
2213 ** to fit in a signed 32-bit integer, return 0 and leave *pValue unchanged.
2214 */
sqlite3ExprIsInteger(Expr * p,int * pValue)2215 int sqlite3ExprIsInteger(Expr *p, int *pValue){
2216 int rc = 0;
2217 if( NEVER(p==0) ) return 0; /* Used to only happen following on OOM */
2218
2219 /* If an expression is an integer literal that fits in a signed 32-bit
2220 ** integer, then the EP_IntValue flag will have already been set */
2221 assert( p->op!=TK_INTEGER || (p->flags & EP_IntValue)!=0
2222 || sqlite3GetInt32(p->u.zToken, &rc)==0 );
2223
2224 if( p->flags & EP_IntValue ){
2225 *pValue = p->u.iValue;
2226 return 1;
2227 }
2228 switch( p->op ){
2229 case TK_UPLUS: {
2230 rc = sqlite3ExprIsInteger(p->pLeft, pValue);
2231 break;
2232 }
2233 case TK_UMINUS: {
2234 int v;
2235 if( sqlite3ExprIsInteger(p->pLeft, &v) ){
2236 assert( v!=(-2147483647-1) );
2237 *pValue = -v;
2238 rc = 1;
2239 }
2240 break;
2241 }
2242 default: break;
2243 }
2244 return rc;
2245 }
2246
2247 /*
2248 ** Return FALSE if there is no chance that the expression can be NULL.
2249 **
2250 ** If the expression might be NULL or if the expression is too complex
2251 ** to tell return TRUE.
2252 **
2253 ** This routine is used as an optimization, to skip OP_IsNull opcodes
2254 ** when we know that a value cannot be NULL. Hence, a false positive
2255 ** (returning TRUE when in fact the expression can never be NULL) might
2256 ** be a small performance hit but is otherwise harmless. On the other
2257 ** hand, a false negative (returning FALSE when the result could be NULL)
2258 ** will likely result in an incorrect answer. So when in doubt, return
2259 ** TRUE.
2260 */
sqlite3ExprCanBeNull(const Expr * p)2261 int sqlite3ExprCanBeNull(const Expr *p){
2262 u8 op;
2263 while( p->op==TK_UPLUS || p->op==TK_UMINUS ){
2264 p = p->pLeft;
2265 }
2266 op = p->op;
2267 if( op==TK_REGISTER ) op = p->op2;
2268 switch( op ){
2269 case TK_INTEGER:
2270 case TK_STRING:
2271 case TK_FLOAT:
2272 case TK_BLOB:
2273 return 0;
2274 case TK_COLUMN:
2275 return ExprHasProperty(p, EP_CanBeNull) ||
2276 p->y.pTab==0 || /* Reference to column of index on expression */
2277 (p->iColumn>=0
2278 && ALWAYS(p->y.pTab->aCol!=0) /* Defense against OOM problems */
2279 && p->y.pTab->aCol[p->iColumn].notNull==0);
2280 default:
2281 return 1;
2282 }
2283 }
2284
2285 /*
2286 ** Return TRUE if the given expression is a constant which would be
2287 ** unchanged by OP_Affinity with the affinity given in the second
2288 ** argument.
2289 **
2290 ** This routine is used to determine if the OP_Affinity operation
2291 ** can be omitted. When in doubt return FALSE. A false negative
2292 ** is harmless. A false positive, however, can result in the wrong
2293 ** answer.
2294 */
sqlite3ExprNeedsNoAffinityChange(const Expr * p,char aff)2295 int sqlite3ExprNeedsNoAffinityChange(const Expr *p, char aff){
2296 u8 op;
2297 int unaryMinus = 0;
2298 if( aff==SQLITE_AFF_BLOB ) return 1;
2299 while( p->op==TK_UPLUS || p->op==TK_UMINUS ){
2300 if( p->op==TK_UMINUS ) unaryMinus = 1;
2301 p = p->pLeft;
2302 }
2303 op = p->op;
2304 if( op==TK_REGISTER ) op = p->op2;
2305 switch( op ){
2306 case TK_INTEGER: {
2307 return aff>=SQLITE_AFF_NUMERIC;
2308 }
2309 case TK_FLOAT: {
2310 return aff>=SQLITE_AFF_NUMERIC;
2311 }
2312 case TK_STRING: {
2313 return !unaryMinus && aff==SQLITE_AFF_TEXT;
2314 }
2315 case TK_BLOB: {
2316 return !unaryMinus;
2317 }
2318 case TK_COLUMN: {
2319 assert( p->iTable>=0 ); /* p cannot be part of a CHECK constraint */
2320 return aff>=SQLITE_AFF_NUMERIC && p->iColumn<0;
2321 }
2322 default: {
2323 return 0;
2324 }
2325 }
2326 }
2327
2328 /*
2329 ** Return TRUE if the given string is a row-id column name.
2330 */
sqlite3IsRowid(const char * z)2331 int sqlite3IsRowid(const char *z){
2332 if( sqlite3StrICmp(z, "_ROWID_")==0 ) return 1;
2333 if( sqlite3StrICmp(z, "ROWID")==0 ) return 1;
2334 if( sqlite3StrICmp(z, "OID")==0 ) return 1;
2335 return 0;
2336 }
2337
2338 /*
2339 ** pX is the RHS of an IN operator. If pX is a SELECT statement
2340 ** that can be simplified to a direct table access, then return
2341 ** a pointer to the SELECT statement. If pX is not a SELECT statement,
2342 ** or if the SELECT statement needs to be manifested into a transient
2343 ** table, then return NULL.
2344 */
2345 #ifndef SQLITE_OMIT_SUBQUERY
isCandidateForInOpt(Expr * pX)2346 static Select *isCandidateForInOpt(Expr *pX){
2347 Select *p;
2348 SrcList *pSrc;
2349 ExprList *pEList;
2350 Table *pTab;
2351 int i;
2352 if( !ExprHasProperty(pX, EP_xIsSelect) ) return 0; /* Not a subquery */
2353 if( ExprHasProperty(pX, EP_VarSelect) ) return 0; /* Correlated subq */
2354 p = pX->x.pSelect;
2355 if( p->pPrior ) return 0; /* Not a compound SELECT */
2356 if( p->selFlags & (SF_Distinct|SF_Aggregate) ){
2357 testcase( (p->selFlags & (SF_Distinct|SF_Aggregate))==SF_Distinct );
2358 testcase( (p->selFlags & (SF_Distinct|SF_Aggregate))==SF_Aggregate );
2359 return 0; /* No DISTINCT keyword and no aggregate functions */
2360 }
2361 assert( p->pGroupBy==0 ); /* Has no GROUP BY clause */
2362 if( p->pLimit ) return 0; /* Has no LIMIT clause */
2363 if( p->pWhere ) return 0; /* Has no WHERE clause */
2364 pSrc = p->pSrc;
2365 assert( pSrc!=0 );
2366 if( pSrc->nSrc!=1 ) return 0; /* Single term in FROM clause */
2367 if( pSrc->a[0].pSelect ) return 0; /* FROM is not a subquery or view */
2368 pTab = pSrc->a[0].pTab;
2369 assert( pTab!=0 );
2370 assert( pTab->pSelect==0 ); /* FROM clause is not a view */
2371 if( IsVirtual(pTab) ) return 0; /* FROM clause not a virtual table */
2372 pEList = p->pEList;
2373 assert( pEList!=0 );
2374 /* All SELECT results must be columns. */
2375 for(i=0; i<pEList->nExpr; i++){
2376 Expr *pRes = pEList->a[i].pExpr;
2377 if( pRes->op!=TK_COLUMN ) return 0;
2378 assert( pRes->iTable==pSrc->a[0].iCursor ); /* Not a correlated subquery */
2379 }
2380 return p;
2381 }
2382 #endif /* SQLITE_OMIT_SUBQUERY */
2383
2384 #ifndef SQLITE_OMIT_SUBQUERY
2385 /*
2386 ** Generate code that checks the left-most column of index table iCur to see if
2387 ** it contains any NULL entries. Cause the register at regHasNull to be set
2388 ** to a non-NULL value if iCur contains no NULLs. Cause register regHasNull
2389 ** to be set to NULL if iCur contains one or more NULL values.
2390 */
sqlite3SetHasNullFlag(Vdbe * v,int iCur,int regHasNull)2391 static void sqlite3SetHasNullFlag(Vdbe *v, int iCur, int regHasNull){
2392 int addr1;
2393 sqlite3VdbeAddOp2(v, OP_Integer, 0, regHasNull);
2394 addr1 = sqlite3VdbeAddOp1(v, OP_Rewind, iCur); VdbeCoverage(v);
2395 sqlite3VdbeAddOp3(v, OP_Column, iCur, 0, regHasNull);
2396 sqlite3VdbeChangeP5(v, OPFLAG_TYPEOFARG);
2397 VdbeComment((v, "first_entry_in(%d)", iCur));
2398 sqlite3VdbeJumpHere(v, addr1);
2399 }
2400 #endif
2401
2402
2403 #ifndef SQLITE_OMIT_SUBQUERY
2404 /*
2405 ** The argument is an IN operator with a list (not a subquery) on the
2406 ** right-hand side. Return TRUE if that list is constant.
2407 */
sqlite3InRhsIsConstant(Expr * pIn)2408 static int sqlite3InRhsIsConstant(Expr *pIn){
2409 Expr *pLHS;
2410 int res;
2411 assert( !ExprHasProperty(pIn, EP_xIsSelect) );
2412 pLHS = pIn->pLeft;
2413 pIn->pLeft = 0;
2414 res = sqlite3ExprIsConstant(pIn);
2415 pIn->pLeft = pLHS;
2416 return res;
2417 }
2418 #endif
2419
2420 /*
2421 ** This function is used by the implementation of the IN (...) operator.
2422 ** The pX parameter is the expression on the RHS of the IN operator, which
2423 ** might be either a list of expressions or a subquery.
2424 **
2425 ** The job of this routine is to find or create a b-tree object that can
2426 ** be used either to test for membership in the RHS set or to iterate through
2427 ** all members of the RHS set, skipping duplicates.
2428 **
2429 ** A cursor is opened on the b-tree object that is the RHS of the IN operator
2430 ** and pX->iTable is set to the index of that cursor.
2431 **
2432 ** The returned value of this function indicates the b-tree type, as follows:
2433 **
2434 ** IN_INDEX_ROWID - The cursor was opened on a database table.
2435 ** IN_INDEX_INDEX_ASC - The cursor was opened on an ascending index.
2436 ** IN_INDEX_INDEX_DESC - The cursor was opened on a descending index.
2437 ** IN_INDEX_EPH - The cursor was opened on a specially created and
2438 ** populated epheremal table.
2439 ** IN_INDEX_NOOP - No cursor was allocated. The IN operator must be
2440 ** implemented as a sequence of comparisons.
2441 **
2442 ** An existing b-tree might be used if the RHS expression pX is a simple
2443 ** subquery such as:
2444 **
2445 ** SELECT <column1>, <column2>... FROM <table>
2446 **
2447 ** If the RHS of the IN operator is a list or a more complex subquery, then
2448 ** an ephemeral table might need to be generated from the RHS and then
2449 ** pX->iTable made to point to the ephemeral table instead of an
2450 ** existing table.
2451 **
2452 ** The inFlags parameter must contain, at a minimum, one of the bits
2453 ** IN_INDEX_MEMBERSHIP or IN_INDEX_LOOP but not both. If inFlags contains
2454 ** IN_INDEX_MEMBERSHIP, then the generated table will be used for a fast
2455 ** membership test. When the IN_INDEX_LOOP bit is set, the IN index will
2456 ** be used to loop over all values of the RHS of the IN operator.
2457 **
2458 ** When IN_INDEX_LOOP is used (and the b-tree will be used to iterate
2459 ** through the set members) then the b-tree must not contain duplicates.
2460 ** An epheremal table will be created unless the selected columns are guaranteed
2461 ** to be unique - either because it is an INTEGER PRIMARY KEY or due to
2462 ** a UNIQUE constraint or index.
2463 **
2464 ** When IN_INDEX_MEMBERSHIP is used (and the b-tree will be used
2465 ** for fast set membership tests) then an epheremal table must
2466 ** be used unless <columns> is a single INTEGER PRIMARY KEY column or an
2467 ** index can be found with the specified <columns> as its left-most.
2468 **
2469 ** If the IN_INDEX_NOOP_OK and IN_INDEX_MEMBERSHIP are both set and
2470 ** if the RHS of the IN operator is a list (not a subquery) then this
2471 ** routine might decide that creating an ephemeral b-tree for membership
2472 ** testing is too expensive and return IN_INDEX_NOOP. In that case, the
2473 ** calling routine should implement the IN operator using a sequence
2474 ** of Eq or Ne comparison operations.
2475 **
2476 ** When the b-tree is being used for membership tests, the calling function
2477 ** might need to know whether or not the RHS side of the IN operator
2478 ** contains a NULL. If prRhsHasNull is not a NULL pointer and
2479 ** if there is any chance that the (...) might contain a NULL value at
2480 ** runtime, then a register is allocated and the register number written
2481 ** to *prRhsHasNull. If there is no chance that the (...) contains a
2482 ** NULL value, then *prRhsHasNull is left unchanged.
2483 **
2484 ** If a register is allocated and its location stored in *prRhsHasNull, then
2485 ** the value in that register will be NULL if the b-tree contains one or more
2486 ** NULL values, and it will be some non-NULL value if the b-tree contains no
2487 ** NULL values.
2488 **
2489 ** If the aiMap parameter is not NULL, it must point to an array containing
2490 ** one element for each column returned by the SELECT statement on the RHS
2491 ** of the IN(...) operator. The i'th entry of the array is populated with the
2492 ** offset of the index column that matches the i'th column returned by the
2493 ** SELECT. For example, if the expression and selected index are:
2494 **
2495 ** (?,?,?) IN (SELECT a, b, c FROM t1)
2496 ** CREATE INDEX i1 ON t1(b, c, a);
2497 **
2498 ** then aiMap[] is populated with {2, 0, 1}.
2499 */
2500 #ifndef SQLITE_OMIT_SUBQUERY
sqlite3FindInIndex(Parse * pParse,Expr * pX,u32 inFlags,int * prRhsHasNull,int * aiMap,int * piTab)2501 int sqlite3FindInIndex(
2502 Parse *pParse, /* Parsing context */
2503 Expr *pX, /* The IN expression */
2504 u32 inFlags, /* IN_INDEX_LOOP, _MEMBERSHIP, and/or _NOOP_OK */
2505 int *prRhsHasNull, /* Register holding NULL status. See notes */
2506 int *aiMap, /* Mapping from Index fields to RHS fields */
2507 int *piTab /* OUT: index to use */
2508 ){
2509 Select *p; /* SELECT to the right of IN operator */
2510 int eType = 0; /* Type of RHS table. IN_INDEX_* */
2511 int iTab = pParse->nTab++; /* Cursor of the RHS table */
2512 int mustBeUnique; /* True if RHS must be unique */
2513 Vdbe *v = sqlite3GetVdbe(pParse); /* Virtual machine being coded */
2514
2515 assert( pX->op==TK_IN );
2516 mustBeUnique = (inFlags & IN_INDEX_LOOP)!=0;
2517
2518 /* If the RHS of this IN(...) operator is a SELECT, and if it matters
2519 ** whether or not the SELECT result contains NULL values, check whether
2520 ** or not NULL is actually possible (it may not be, for example, due
2521 ** to NOT NULL constraints in the schema). If no NULL values are possible,
2522 ** set prRhsHasNull to 0 before continuing. */
2523 if( prRhsHasNull && (pX->flags & EP_xIsSelect) ){
2524 int i;
2525 ExprList *pEList = pX->x.pSelect->pEList;
2526 for(i=0; i<pEList->nExpr; i++){
2527 if( sqlite3ExprCanBeNull(pEList->a[i].pExpr) ) break;
2528 }
2529 if( i==pEList->nExpr ){
2530 prRhsHasNull = 0;
2531 }
2532 }
2533
2534 /* Check to see if an existing table or index can be used to
2535 ** satisfy the query. This is preferable to generating a new
2536 ** ephemeral table. */
2537 if( pParse->nErr==0 && (p = isCandidateForInOpt(pX))!=0 ){
2538 sqlite3 *db = pParse->db; /* Database connection */
2539 Table *pTab; /* Table <table>. */
2540 i16 iDb; /* Database idx for pTab */
2541 ExprList *pEList = p->pEList;
2542 int nExpr = pEList->nExpr;
2543
2544 assert( p->pEList!=0 ); /* Because of isCandidateForInOpt(p) */
2545 assert( p->pEList->a[0].pExpr!=0 ); /* Because of isCandidateForInOpt(p) */
2546 assert( p->pSrc!=0 ); /* Because of isCandidateForInOpt(p) */
2547 pTab = p->pSrc->a[0].pTab;
2548
2549 /* Code an OP_Transaction and OP_TableLock for <table>. */
2550 iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
2551 sqlite3CodeVerifySchema(pParse, iDb);
2552 sqlite3TableLock(pParse, iDb, pTab->tnum, 0, pTab->zName);
2553
2554 assert(v); /* sqlite3GetVdbe() has always been previously called */
2555 if( nExpr==1 && pEList->a[0].pExpr->iColumn<0 ){
2556 /* The "x IN (SELECT rowid FROM table)" case */
2557 int iAddr = sqlite3VdbeAddOp0(v, OP_Once);
2558 VdbeCoverage(v);
2559
2560 sqlite3OpenTable(pParse, iTab, iDb, pTab, OP_OpenRead);
2561 eType = IN_INDEX_ROWID;
2562 ExplainQueryPlan((pParse, 0,
2563 "USING ROWID SEARCH ON TABLE %s FOR IN-OPERATOR",pTab->zName));
2564 sqlite3VdbeJumpHere(v, iAddr);
2565 }else{
2566 Index *pIdx; /* Iterator variable */
2567 int affinity_ok = 1;
2568 int i;
2569
2570 /* Check that the affinity that will be used to perform each
2571 ** comparison is the same as the affinity of each column in table
2572 ** on the RHS of the IN operator. If it not, it is not possible to
2573 ** use any index of the RHS table. */
2574 for(i=0; i<nExpr && affinity_ok; i++){
2575 Expr *pLhs = sqlite3VectorFieldSubexpr(pX->pLeft, i);
2576 int iCol = pEList->a[i].pExpr->iColumn;
2577 char idxaff = sqlite3TableColumnAffinity(pTab,iCol); /* RHS table */
2578 char cmpaff = sqlite3CompareAffinity(pLhs, idxaff);
2579 testcase( cmpaff==SQLITE_AFF_BLOB );
2580 testcase( cmpaff==SQLITE_AFF_TEXT );
2581 switch( cmpaff ){
2582 case SQLITE_AFF_BLOB:
2583 break;
2584 case SQLITE_AFF_TEXT:
2585 /* sqlite3CompareAffinity() only returns TEXT if one side or the
2586 ** other has no affinity and the other side is TEXT. Hence,
2587 ** the only way for cmpaff to be TEXT is for idxaff to be TEXT
2588 ** and for the term on the LHS of the IN to have no affinity. */
2589 assert( idxaff==SQLITE_AFF_TEXT );
2590 break;
2591 default:
2592 affinity_ok = sqlite3IsNumericAffinity(idxaff);
2593 }
2594 }
2595
2596 if( affinity_ok ){
2597 /* Search for an existing index that will work for this IN operator */
2598 for(pIdx=pTab->pIndex; pIdx && eType==0; pIdx=pIdx->pNext){
2599 Bitmask colUsed; /* Columns of the index used */
2600 Bitmask mCol; /* Mask for the current column */
2601 if( pIdx->nColumn<nExpr ) continue;
2602 if( pIdx->pPartIdxWhere!=0 ) continue;
2603 /* Maximum nColumn is BMS-2, not BMS-1, so that we can compute
2604 ** BITMASK(nExpr) without overflowing */
2605 testcase( pIdx->nColumn==BMS-2 );
2606 testcase( pIdx->nColumn==BMS-1 );
2607 if( pIdx->nColumn>=BMS-1 ) continue;
2608 if( mustBeUnique ){
2609 if( pIdx->nKeyCol>nExpr
2610 ||(pIdx->nColumn>nExpr && !IsUniqueIndex(pIdx))
2611 ){
2612 continue; /* This index is not unique over the IN RHS columns */
2613 }
2614 }
2615
2616 colUsed = 0; /* Columns of index used so far */
2617 for(i=0; i<nExpr; i++){
2618 Expr *pLhs = sqlite3VectorFieldSubexpr(pX->pLeft, i);
2619 Expr *pRhs = pEList->a[i].pExpr;
2620 CollSeq *pReq = sqlite3BinaryCompareCollSeq(pParse, pLhs, pRhs);
2621 int j;
2622
2623 assert( pReq!=0 || pRhs->iColumn==XN_ROWID || pParse->nErr );
2624 for(j=0; j<nExpr; j++){
2625 if( pIdx->aiColumn[j]!=pRhs->iColumn ) continue;
2626 assert( pIdx->azColl[j] );
2627 if( pReq!=0 && sqlite3StrICmp(pReq->zName, pIdx->azColl[j])!=0 ){
2628 continue;
2629 }
2630 break;
2631 }
2632 if( j==nExpr ) break;
2633 mCol = MASKBIT(j);
2634 if( mCol & colUsed ) break; /* Each column used only once */
2635 colUsed |= mCol;
2636 if( aiMap ) aiMap[i] = j;
2637 }
2638
2639 assert( i==nExpr || colUsed!=(MASKBIT(nExpr)-1) );
2640 if( colUsed==(MASKBIT(nExpr)-1) ){
2641 /* If we reach this point, that means the index pIdx is usable */
2642 int iAddr = sqlite3VdbeAddOp0(v, OP_Once); VdbeCoverage(v);
2643 ExplainQueryPlan((pParse, 0,
2644 "USING INDEX %s FOR IN-OPERATOR",pIdx->zName));
2645 sqlite3VdbeAddOp3(v, OP_OpenRead, iTab, pIdx->tnum, iDb);
2646 sqlite3VdbeSetP4KeyInfo(pParse, pIdx);
2647 VdbeComment((v, "%s", pIdx->zName));
2648 assert( IN_INDEX_INDEX_DESC == IN_INDEX_INDEX_ASC+1 );
2649 eType = IN_INDEX_INDEX_ASC + pIdx->aSortOrder[0];
2650
2651 if( prRhsHasNull ){
2652 #ifdef SQLITE_ENABLE_COLUMN_USED_MASK
2653 i64 mask = (1<<nExpr)-1;
2654 sqlite3VdbeAddOp4Dup8(v, OP_ColumnsUsed,
2655 iTab, 0, 0, (u8*)&mask, P4_INT64);
2656 #endif
2657 *prRhsHasNull = ++pParse->nMem;
2658 if( nExpr==1 ){
2659 sqlite3SetHasNullFlag(v, iTab, *prRhsHasNull);
2660 }
2661 }
2662 sqlite3VdbeJumpHere(v, iAddr);
2663 }
2664 } /* End loop over indexes */
2665 } /* End if( affinity_ok ) */
2666 } /* End if not an rowid index */
2667 } /* End attempt to optimize using an index */
2668
2669 /* If no preexisting index is available for the IN clause
2670 ** and IN_INDEX_NOOP is an allowed reply
2671 ** and the RHS of the IN operator is a list, not a subquery
2672 ** and the RHS is not constant or has two or fewer terms,
2673 ** then it is not worth creating an ephemeral table to evaluate
2674 ** the IN operator so return IN_INDEX_NOOP.
2675 */
2676 if( eType==0
2677 && (inFlags & IN_INDEX_NOOP_OK)
2678 && !ExprHasProperty(pX, EP_xIsSelect)
2679 && (!sqlite3InRhsIsConstant(pX) || pX->x.pList->nExpr<=2)
2680 ){
2681 eType = IN_INDEX_NOOP;
2682 }
2683
2684 if( eType==0 ){
2685 /* Could not find an existing table or index to use as the RHS b-tree.
2686 ** We will have to generate an ephemeral table to do the job.
2687 */
2688 u32 savedNQueryLoop = pParse->nQueryLoop;
2689 int rMayHaveNull = 0;
2690 eType = IN_INDEX_EPH;
2691 if( inFlags & IN_INDEX_LOOP ){
2692 pParse->nQueryLoop = 0;
2693 }else if( prRhsHasNull ){
2694 *prRhsHasNull = rMayHaveNull = ++pParse->nMem;
2695 }
2696 assert( pX->op==TK_IN );
2697 sqlite3CodeRhsOfIN(pParse, pX, iTab);
2698 if( rMayHaveNull ){
2699 sqlite3SetHasNullFlag(v, iTab, rMayHaveNull);
2700 }
2701 pParse->nQueryLoop = savedNQueryLoop;
2702 }
2703
2704 if( aiMap && eType!=IN_INDEX_INDEX_ASC && eType!=IN_INDEX_INDEX_DESC ){
2705 int i, n;
2706 n = sqlite3ExprVectorSize(pX->pLeft);
2707 for(i=0; i<n; i++) aiMap[i] = i;
2708 }
2709 *piTab = iTab;
2710 return eType;
2711 }
2712 #endif
2713
2714 #ifndef SQLITE_OMIT_SUBQUERY
2715 /*
2716 ** Argument pExpr is an (?, ?...) IN(...) expression. This
2717 ** function allocates and returns a nul-terminated string containing
2718 ** the affinities to be used for each column of the comparison.
2719 **
2720 ** It is the responsibility of the caller to ensure that the returned
2721 ** string is eventually freed using sqlite3DbFree().
2722 */
exprINAffinity(Parse * pParse,Expr * pExpr)2723 static char *exprINAffinity(Parse *pParse, Expr *pExpr){
2724 Expr *pLeft = pExpr->pLeft;
2725 int nVal = sqlite3ExprVectorSize(pLeft);
2726 Select *pSelect = (pExpr->flags & EP_xIsSelect) ? pExpr->x.pSelect : 0;
2727 char *zRet;
2728
2729 assert( pExpr->op==TK_IN );
2730 zRet = sqlite3DbMallocRaw(pParse->db, nVal+1);
2731 if( zRet ){
2732 int i;
2733 for(i=0; i<nVal; i++){
2734 Expr *pA = sqlite3VectorFieldSubexpr(pLeft, i);
2735 char a = sqlite3ExprAffinity(pA);
2736 if( pSelect ){
2737 zRet[i] = sqlite3CompareAffinity(pSelect->pEList->a[i].pExpr, a);
2738 }else{
2739 zRet[i] = a;
2740 }
2741 }
2742 zRet[nVal] = '\0';
2743 }
2744 return zRet;
2745 }
2746 #endif
2747
2748 #ifndef SQLITE_OMIT_SUBQUERY
2749 /*
2750 ** Load the Parse object passed as the first argument with an error
2751 ** message of the form:
2752 **
2753 ** "sub-select returns N columns - expected M"
2754 */
sqlite3SubselectError(Parse * pParse,int nActual,int nExpect)2755 void sqlite3SubselectError(Parse *pParse, int nActual, int nExpect){
2756 if( pParse->nErr==0 ){
2757 const char *zFmt = "sub-select returns %d columns - expected %d";
2758 sqlite3ErrorMsg(pParse, zFmt, nActual, nExpect);
2759 }
2760 }
2761 #endif
2762
2763 /*
2764 ** Expression pExpr is a vector that has been used in a context where
2765 ** it is not permitted. If pExpr is a sub-select vector, this routine
2766 ** loads the Parse object with a message of the form:
2767 **
2768 ** "sub-select returns N columns - expected 1"
2769 **
2770 ** Or, if it is a regular scalar vector:
2771 **
2772 ** "row value misused"
2773 */
sqlite3VectorErrorMsg(Parse * pParse,Expr * pExpr)2774 void sqlite3VectorErrorMsg(Parse *pParse, Expr *pExpr){
2775 #ifndef SQLITE_OMIT_SUBQUERY
2776 if( pExpr->flags & EP_xIsSelect ){
2777 sqlite3SubselectError(pParse, pExpr->x.pSelect->pEList->nExpr, 1);
2778 }else
2779 #endif
2780 {
2781 sqlite3ErrorMsg(pParse, "row value misused");
2782 }
2783 }
2784
2785 #ifndef SQLITE_OMIT_SUBQUERY
2786 /*
2787 ** Generate code that will construct an ephemeral table containing all terms
2788 ** in the RHS of an IN operator. The IN operator can be in either of two
2789 ** forms:
2790 **
2791 ** x IN (4,5,11) -- IN operator with list on right-hand side
2792 ** x IN (SELECT a FROM b) -- IN operator with subquery on the right
2793 **
2794 ** The pExpr parameter is the IN operator. The cursor number for the
2795 ** constructed ephermeral table is returned. The first time the ephemeral
2796 ** table is computed, the cursor number is also stored in pExpr->iTable,
2797 ** however the cursor number returned might not be the same, as it might
2798 ** have been duplicated using OP_OpenDup.
2799 **
2800 ** If the LHS expression ("x" in the examples) is a column value, or
2801 ** the SELECT statement returns a column value, then the affinity of that
2802 ** column is used to build the index keys. If both 'x' and the
2803 ** SELECT... statement are columns, then numeric affinity is used
2804 ** if either column has NUMERIC or INTEGER affinity. If neither
2805 ** 'x' nor the SELECT... statement are columns, then numeric affinity
2806 ** is used.
2807 */
sqlite3CodeRhsOfIN(Parse * pParse,Expr * pExpr,int iTab)2808 void sqlite3CodeRhsOfIN(
2809 Parse *pParse, /* Parsing context */
2810 Expr *pExpr, /* The IN operator */
2811 int iTab /* Use this cursor number */
2812 ){
2813 int addrOnce = 0; /* Address of the OP_Once instruction at top */
2814 int addr; /* Address of OP_OpenEphemeral instruction */
2815 Expr *pLeft; /* the LHS of the IN operator */
2816 KeyInfo *pKeyInfo = 0; /* Key information */
2817 int nVal; /* Size of vector pLeft */
2818 Vdbe *v; /* The prepared statement under construction */
2819
2820 v = pParse->pVdbe;
2821 assert( v!=0 );
2822
2823 /* The evaluation of the IN must be repeated every time it
2824 ** is encountered if any of the following is true:
2825 **
2826 ** * The right-hand side is a correlated subquery
2827 ** * The right-hand side is an expression list containing variables
2828 ** * We are inside a trigger
2829 **
2830 ** If all of the above are false, then we can compute the RHS just once
2831 ** and reuse it many names.
2832 */
2833 if( !ExprHasProperty(pExpr, EP_VarSelect) && pParse->iSelfTab==0 ){
2834 /* Reuse of the RHS is allowed */
2835 /* If this routine has already been coded, but the previous code
2836 ** might not have been invoked yet, so invoke it now as a subroutine.
2837 */
2838 if( ExprHasProperty(pExpr, EP_Subrtn) ){
2839 addrOnce = sqlite3VdbeAddOp0(v, OP_Once); VdbeCoverage(v);
2840 if( ExprHasProperty(pExpr, EP_xIsSelect) ){
2841 ExplainQueryPlan((pParse, 0, "REUSE LIST SUBQUERY %d",
2842 pExpr->x.pSelect->selId));
2843 }
2844 sqlite3VdbeAddOp2(v, OP_Gosub, pExpr->y.sub.regReturn,
2845 pExpr->y.sub.iAddr);
2846 sqlite3VdbeAddOp2(v, OP_OpenDup, iTab, pExpr->iTable);
2847 sqlite3VdbeJumpHere(v, addrOnce);
2848 return;
2849 }
2850
2851 /* Begin coding the subroutine */
2852 ExprSetProperty(pExpr, EP_Subrtn);
2853 assert( !ExprHasProperty(pExpr, EP_TokenOnly|EP_Reduced) );
2854 pExpr->y.sub.regReturn = ++pParse->nMem;
2855 pExpr->y.sub.iAddr =
2856 sqlite3VdbeAddOp2(v, OP_Integer, 0, pExpr->y.sub.regReturn) + 1;
2857 VdbeComment((v, "return address"));
2858
2859 addrOnce = sqlite3VdbeAddOp0(v, OP_Once); VdbeCoverage(v);
2860 }
2861
2862 /* Check to see if this is a vector IN operator */
2863 pLeft = pExpr->pLeft;
2864 nVal = sqlite3ExprVectorSize(pLeft);
2865
2866 /* Construct the ephemeral table that will contain the content of
2867 ** RHS of the IN operator.
2868 */
2869 pExpr->iTable = iTab;
2870 addr = sqlite3VdbeAddOp2(v, OP_OpenEphemeral, pExpr->iTable, nVal);
2871 #ifdef SQLITE_ENABLE_EXPLAIN_COMMENTS
2872 if( ExprHasProperty(pExpr, EP_xIsSelect) ){
2873 VdbeComment((v, "Result of SELECT %u", pExpr->x.pSelect->selId));
2874 }else{
2875 VdbeComment((v, "RHS of IN operator"));
2876 }
2877 #endif
2878 pKeyInfo = sqlite3KeyInfoAlloc(pParse->db, nVal, 1);
2879
2880 if( ExprHasProperty(pExpr, EP_xIsSelect) ){
2881 /* Case 1: expr IN (SELECT ...)
2882 **
2883 ** Generate code to write the results of the select into the temporary
2884 ** table allocated and opened above.
2885 */
2886 Select *pSelect = pExpr->x.pSelect;
2887 ExprList *pEList = pSelect->pEList;
2888
2889 ExplainQueryPlan((pParse, 1, "%sLIST SUBQUERY %d",
2890 addrOnce?"":"CORRELATED ", pSelect->selId
2891 ));
2892 /* If the LHS and RHS of the IN operator do not match, that
2893 ** error will have been caught long before we reach this point. */
2894 if( ALWAYS(pEList->nExpr==nVal) ){
2895 SelectDest dest;
2896 int i;
2897 sqlite3SelectDestInit(&dest, SRT_Set, iTab);
2898 dest.zAffSdst = exprINAffinity(pParse, pExpr);
2899 pSelect->iLimit = 0;
2900 testcase( pSelect->selFlags & SF_Distinct );
2901 testcase( pKeyInfo==0 ); /* Caused by OOM in sqlite3KeyInfoAlloc() */
2902 if( sqlite3Select(pParse, pSelect, &dest) ){
2903 sqlite3DbFree(pParse->db, dest.zAffSdst);
2904 sqlite3KeyInfoUnref(pKeyInfo);
2905 return;
2906 }
2907 sqlite3DbFree(pParse->db, dest.zAffSdst);
2908 assert( pKeyInfo!=0 ); /* OOM will cause exit after sqlite3Select() */
2909 assert( pEList!=0 );
2910 assert( pEList->nExpr>0 );
2911 assert( sqlite3KeyInfoIsWriteable(pKeyInfo) );
2912 for(i=0; i<nVal; i++){
2913 Expr *p = sqlite3VectorFieldSubexpr(pLeft, i);
2914 pKeyInfo->aColl[i] = sqlite3BinaryCompareCollSeq(
2915 pParse, p, pEList->a[i].pExpr
2916 );
2917 }
2918 }
2919 }else if( ALWAYS(pExpr->x.pList!=0) ){
2920 /* Case 2: expr IN (exprlist)
2921 **
2922 ** For each expression, build an index key from the evaluation and
2923 ** store it in the temporary table. If <expr> is a column, then use
2924 ** that columns affinity when building index keys. If <expr> is not
2925 ** a column, use numeric affinity.
2926 */
2927 char affinity; /* Affinity of the LHS of the IN */
2928 int i;
2929 ExprList *pList = pExpr->x.pList;
2930 struct ExprList_item *pItem;
2931 int r1, r2;
2932 affinity = sqlite3ExprAffinity(pLeft);
2933 if( affinity<=SQLITE_AFF_NONE ){
2934 affinity = SQLITE_AFF_BLOB;
2935 }
2936 if( pKeyInfo ){
2937 assert( sqlite3KeyInfoIsWriteable(pKeyInfo) );
2938 pKeyInfo->aColl[0] = sqlite3ExprCollSeq(pParse, pExpr->pLeft);
2939 }
2940
2941 /* Loop through each expression in <exprlist>. */
2942 r1 = sqlite3GetTempReg(pParse);
2943 r2 = sqlite3GetTempReg(pParse);
2944 for(i=pList->nExpr, pItem=pList->a; i>0; i--, pItem++){
2945 Expr *pE2 = pItem->pExpr;
2946
2947 /* If the expression is not constant then we will need to
2948 ** disable the test that was generated above that makes sure
2949 ** this code only executes once. Because for a non-constant
2950 ** expression we need to rerun this code each time.
2951 */
2952 if( addrOnce && !sqlite3ExprIsConstant(pE2) ){
2953 sqlite3VdbeChangeToNoop(v, addrOnce);
2954 ExprClearProperty(pExpr, EP_Subrtn);
2955 addrOnce = 0;
2956 }
2957
2958 /* Evaluate the expression and insert it into the temp table */
2959 sqlite3ExprCode(pParse, pE2, r1);
2960 sqlite3VdbeAddOp4(v, OP_MakeRecord, r1, 1, r2, &affinity, 1);
2961 sqlite3VdbeAddOp4Int(v, OP_IdxInsert, iTab, r2, r1, 1);
2962 }
2963 sqlite3ReleaseTempReg(pParse, r1);
2964 sqlite3ReleaseTempReg(pParse, r2);
2965 }
2966 if( pKeyInfo ){
2967 sqlite3VdbeChangeP4(v, addr, (void *)pKeyInfo, P4_KEYINFO);
2968 }
2969 if( addrOnce ){
2970 sqlite3VdbeJumpHere(v, addrOnce);
2971 /* Subroutine return */
2972 sqlite3VdbeAddOp1(v, OP_Return, pExpr->y.sub.regReturn);
2973 sqlite3VdbeChangeP1(v, pExpr->y.sub.iAddr-1, sqlite3VdbeCurrentAddr(v)-1);
2974 sqlite3ClearTempRegCache(pParse);
2975 }
2976 }
2977 #endif /* SQLITE_OMIT_SUBQUERY */
2978
2979 /*
2980 ** Generate code for scalar subqueries used as a subquery expression
2981 ** or EXISTS operator:
2982 **
2983 ** (SELECT a FROM b) -- subquery
2984 ** EXISTS (SELECT a FROM b) -- EXISTS subquery
2985 **
2986 ** The pExpr parameter is the SELECT or EXISTS operator to be coded.
2987 **
2988 ** Return the register that holds the result. For a multi-column SELECT,
2989 ** the result is stored in a contiguous array of registers and the
2990 ** return value is the register of the left-most result column.
2991 ** Return 0 if an error occurs.
2992 */
2993 #ifndef SQLITE_OMIT_SUBQUERY
sqlite3CodeSubselect(Parse * pParse,Expr * pExpr)2994 int sqlite3CodeSubselect(Parse *pParse, Expr *pExpr){
2995 int addrOnce = 0; /* Address of OP_Once at top of subroutine */
2996 int rReg = 0; /* Register storing resulting */
2997 Select *pSel; /* SELECT statement to encode */
2998 SelectDest dest; /* How to deal with SELECT result */
2999 int nReg; /* Registers to allocate */
3000 Expr *pLimit; /* New limit expression */
3001
3002 Vdbe *v = pParse->pVdbe;
3003 assert( v!=0 );
3004 testcase( pExpr->op==TK_EXISTS );
3005 testcase( pExpr->op==TK_SELECT );
3006 assert( pExpr->op==TK_EXISTS || pExpr->op==TK_SELECT );
3007 assert( ExprHasProperty(pExpr, EP_xIsSelect) );
3008 pSel = pExpr->x.pSelect;
3009
3010 /* The evaluation of the EXISTS/SELECT must be repeated every time it
3011 ** is encountered if any of the following is true:
3012 **
3013 ** * The right-hand side is a correlated subquery
3014 ** * The right-hand side is an expression list containing variables
3015 ** * We are inside a trigger
3016 **
3017 ** If all of the above are false, then we can run this code just once
3018 ** save the results, and reuse the same result on subsequent invocations.
3019 */
3020 if( !ExprHasProperty(pExpr, EP_VarSelect) ){
3021 /* If this routine has already been coded, then invoke it as a
3022 ** subroutine. */
3023 if( ExprHasProperty(pExpr, EP_Subrtn) ){
3024 ExplainQueryPlan((pParse, 0, "REUSE SUBQUERY %d", pSel->selId));
3025 sqlite3VdbeAddOp2(v, OP_Gosub, pExpr->y.sub.regReturn,
3026 pExpr->y.sub.iAddr);
3027 return pExpr->iTable;
3028 }
3029
3030 /* Begin coding the subroutine */
3031 ExprSetProperty(pExpr, EP_Subrtn);
3032 pExpr->y.sub.regReturn = ++pParse->nMem;
3033 pExpr->y.sub.iAddr =
3034 sqlite3VdbeAddOp2(v, OP_Integer, 0, pExpr->y.sub.regReturn) + 1;
3035 VdbeComment((v, "return address"));
3036
3037 addrOnce = sqlite3VdbeAddOp0(v, OP_Once); VdbeCoverage(v);
3038 }
3039
3040 /* For a SELECT, generate code to put the values for all columns of
3041 ** the first row into an array of registers and return the index of
3042 ** the first register.
3043 **
3044 ** If this is an EXISTS, write an integer 0 (not exists) or 1 (exists)
3045 ** into a register and return that register number.
3046 **
3047 ** In both cases, the query is augmented with "LIMIT 1". Any
3048 ** preexisting limit is discarded in place of the new LIMIT 1.
3049 */
3050 ExplainQueryPlan((pParse, 1, "%sSCALAR SUBQUERY %d",
3051 addrOnce?"":"CORRELATED ", pSel->selId));
3052 nReg = pExpr->op==TK_SELECT ? pSel->pEList->nExpr : 1;
3053 sqlite3SelectDestInit(&dest, 0, pParse->nMem+1);
3054 pParse->nMem += nReg;
3055 if( pExpr->op==TK_SELECT ){
3056 dest.eDest = SRT_Mem;
3057 dest.iSdst = dest.iSDParm;
3058 dest.nSdst = nReg;
3059 sqlite3VdbeAddOp3(v, OP_Null, 0, dest.iSDParm, dest.iSDParm+nReg-1);
3060 VdbeComment((v, "Init subquery result"));
3061 }else{
3062 dest.eDest = SRT_Exists;
3063 sqlite3VdbeAddOp2(v, OP_Integer, 0, dest.iSDParm);
3064 VdbeComment((v, "Init EXISTS result"));
3065 }
3066 if( pSel->pLimit ){
3067 /* The subquery already has a limit. If the pre-existing limit is X
3068 ** then make the new limit X<>0 so that the new limit is either 1 or 0 */
3069 sqlite3 *db = pParse->db;
3070 pLimit = sqlite3Expr(db, TK_INTEGER, "0");
3071 if( pLimit ){
3072 pLimit->affExpr = SQLITE_AFF_NUMERIC;
3073 pLimit = sqlite3PExpr(pParse, TK_NE,
3074 sqlite3ExprDup(db, pSel->pLimit->pLeft, 0), pLimit);
3075 }
3076 sqlite3ExprDelete(db, pSel->pLimit->pLeft);
3077 pSel->pLimit->pLeft = pLimit;
3078 }else{
3079 /* If there is no pre-existing limit add a limit of 1 */
3080 pLimit = sqlite3Expr(pParse->db, TK_INTEGER, "1");
3081 pSel->pLimit = sqlite3PExpr(pParse, TK_LIMIT, pLimit, 0);
3082 }
3083 pSel->iLimit = 0;
3084 if( sqlite3Select(pParse, pSel, &dest) ){
3085 return 0;
3086 }
3087 pExpr->iTable = rReg = dest.iSDParm;
3088 ExprSetVVAProperty(pExpr, EP_NoReduce);
3089 if( addrOnce ){
3090 sqlite3VdbeJumpHere(v, addrOnce);
3091
3092 /* Subroutine return */
3093 sqlite3VdbeAddOp1(v, OP_Return, pExpr->y.sub.regReturn);
3094 sqlite3VdbeChangeP1(v, pExpr->y.sub.iAddr-1, sqlite3VdbeCurrentAddr(v)-1);
3095 sqlite3ClearTempRegCache(pParse);
3096 }
3097
3098 return rReg;
3099 }
3100 #endif /* SQLITE_OMIT_SUBQUERY */
3101
3102 #ifndef SQLITE_OMIT_SUBQUERY
3103 /*
3104 ** Expr pIn is an IN(...) expression. This function checks that the
3105 ** sub-select on the RHS of the IN() operator has the same number of
3106 ** columns as the vector on the LHS. Or, if the RHS of the IN() is not
3107 ** a sub-query, that the LHS is a vector of size 1.
3108 */
sqlite3ExprCheckIN(Parse * pParse,Expr * pIn)3109 int sqlite3ExprCheckIN(Parse *pParse, Expr *pIn){
3110 int nVector = sqlite3ExprVectorSize(pIn->pLeft);
3111 if( (pIn->flags & EP_xIsSelect) ){
3112 if( nVector!=pIn->x.pSelect->pEList->nExpr ){
3113 sqlite3SubselectError(pParse, pIn->x.pSelect->pEList->nExpr, nVector);
3114 return 1;
3115 }
3116 }else if( nVector!=1 ){
3117 sqlite3VectorErrorMsg(pParse, pIn->pLeft);
3118 return 1;
3119 }
3120 return 0;
3121 }
3122 #endif
3123
3124 #ifndef SQLITE_OMIT_SUBQUERY
3125 /*
3126 ** Generate code for an IN expression.
3127 **
3128 ** x IN (SELECT ...)
3129 ** x IN (value, value, ...)
3130 **
3131 ** The left-hand side (LHS) is a scalar or vector expression. The
3132 ** right-hand side (RHS) is an array of zero or more scalar values, or a
3133 ** subquery. If the RHS is a subquery, the number of result columns must
3134 ** match the number of columns in the vector on the LHS. If the RHS is
3135 ** a list of values, the LHS must be a scalar.
3136 **
3137 ** The IN operator is true if the LHS value is contained within the RHS.
3138 ** The result is false if the LHS is definitely not in the RHS. The
3139 ** result is NULL if the presence of the LHS in the RHS cannot be
3140 ** determined due to NULLs.
3141 **
3142 ** This routine generates code that jumps to destIfFalse if the LHS is not
3143 ** contained within the RHS. If due to NULLs we cannot determine if the LHS
3144 ** is contained in the RHS then jump to destIfNull. If the LHS is contained
3145 ** within the RHS then fall through.
3146 **
3147 ** See the separate in-operator.md documentation file in the canonical
3148 ** SQLite source tree for additional information.
3149 */
sqlite3ExprCodeIN(Parse * pParse,Expr * pExpr,int destIfFalse,int destIfNull)3150 static void sqlite3ExprCodeIN(
3151 Parse *pParse, /* Parsing and code generating context */
3152 Expr *pExpr, /* The IN expression */
3153 int destIfFalse, /* Jump here if LHS is not contained in the RHS */
3154 int destIfNull /* Jump here if the results are unknown due to NULLs */
3155 ){
3156 int rRhsHasNull = 0; /* Register that is true if RHS contains NULL values */
3157 int eType; /* Type of the RHS */
3158 int rLhs; /* Register(s) holding the LHS values */
3159 int rLhsOrig; /* LHS values prior to reordering by aiMap[] */
3160 Vdbe *v; /* Statement under construction */
3161 int *aiMap = 0; /* Map from vector field to index column */
3162 char *zAff = 0; /* Affinity string for comparisons */
3163 int nVector; /* Size of vectors for this IN operator */
3164 int iDummy; /* Dummy parameter to exprCodeVector() */
3165 Expr *pLeft; /* The LHS of the IN operator */
3166 int i; /* loop counter */
3167 int destStep2; /* Where to jump when NULLs seen in step 2 */
3168 int destStep6 = 0; /* Start of code for Step 6 */
3169 int addrTruthOp; /* Address of opcode that determines the IN is true */
3170 int destNotNull; /* Jump here if a comparison is not true in step 6 */
3171 int addrTop; /* Top of the step-6 loop */
3172 int iTab = 0; /* Index to use */
3173
3174 pLeft = pExpr->pLeft;
3175 if( sqlite3ExprCheckIN(pParse, pExpr) ) return;
3176 zAff = exprINAffinity(pParse, pExpr);
3177 nVector = sqlite3ExprVectorSize(pExpr->pLeft);
3178 aiMap = (int*)sqlite3DbMallocZero(
3179 pParse->db, nVector*(sizeof(int) + sizeof(char)) + 1
3180 );
3181 if( pParse->db->mallocFailed ) goto sqlite3ExprCodeIN_oom_error;
3182
3183 /* Attempt to compute the RHS. After this step, if anything other than
3184 ** IN_INDEX_NOOP is returned, the table opened with cursor iTab
3185 ** contains the values that make up the RHS. If IN_INDEX_NOOP is returned,
3186 ** the RHS has not yet been coded. */
3187 v = pParse->pVdbe;
3188 assert( v!=0 ); /* OOM detected prior to this routine */
3189 VdbeNoopComment((v, "begin IN expr"));
3190 eType = sqlite3FindInIndex(pParse, pExpr,
3191 IN_INDEX_MEMBERSHIP | IN_INDEX_NOOP_OK,
3192 destIfFalse==destIfNull ? 0 : &rRhsHasNull,
3193 aiMap, &iTab);
3194
3195 assert( pParse->nErr || nVector==1 || eType==IN_INDEX_EPH
3196 || eType==IN_INDEX_INDEX_ASC || eType==IN_INDEX_INDEX_DESC
3197 );
3198 #ifdef SQLITE_DEBUG
3199 /* Confirm that aiMap[] contains nVector integer values between 0 and
3200 ** nVector-1. */
3201 for(i=0; i<nVector; i++){
3202 int j, cnt;
3203 for(cnt=j=0; j<nVector; j++) if( aiMap[j]==i ) cnt++;
3204 assert( cnt==1 );
3205 }
3206 #endif
3207
3208 /* Code the LHS, the <expr> from "<expr> IN (...)". If the LHS is a
3209 ** vector, then it is stored in an array of nVector registers starting
3210 ** at r1.
3211 **
3212 ** sqlite3FindInIndex() might have reordered the fields of the LHS vector
3213 ** so that the fields are in the same order as an existing index. The
3214 ** aiMap[] array contains a mapping from the original LHS field order to
3215 ** the field order that matches the RHS index.
3216 */
3217 rLhsOrig = exprCodeVector(pParse, pLeft, &iDummy);
3218 for(i=0; i<nVector && aiMap[i]==i; i++){} /* Are LHS fields reordered? */
3219 if( i==nVector ){
3220 /* LHS fields are not reordered */
3221 rLhs = rLhsOrig;
3222 }else{
3223 /* Need to reorder the LHS fields according to aiMap */
3224 rLhs = sqlite3GetTempRange(pParse, nVector);
3225 for(i=0; i<nVector; i++){
3226 sqlite3VdbeAddOp3(v, OP_Copy, rLhsOrig+i, rLhs+aiMap[i], 0);
3227 }
3228 }
3229
3230 /* If sqlite3FindInIndex() did not find or create an index that is
3231 ** suitable for evaluating the IN operator, then evaluate using a
3232 ** sequence of comparisons.
3233 **
3234 ** This is step (1) in the in-operator.md optimized algorithm.
3235 */
3236 if( eType==IN_INDEX_NOOP ){
3237 ExprList *pList = pExpr->x.pList;
3238 CollSeq *pColl = sqlite3ExprCollSeq(pParse, pExpr->pLeft);
3239 int labelOk = sqlite3VdbeMakeLabel(pParse);
3240 int r2, regToFree;
3241 int regCkNull = 0;
3242 int ii;
3243 int bLhsReal; /* True if the LHS of the IN has REAL affinity */
3244 assert( !ExprHasProperty(pExpr, EP_xIsSelect) );
3245 if( destIfNull!=destIfFalse ){
3246 regCkNull = sqlite3GetTempReg(pParse);
3247 sqlite3VdbeAddOp3(v, OP_BitAnd, rLhs, rLhs, regCkNull);
3248 }
3249 bLhsReal = sqlite3ExprAffinity(pExpr->pLeft)==SQLITE_AFF_REAL;
3250 for(ii=0; ii<pList->nExpr; ii++){
3251 if( bLhsReal ){
3252 r2 = regToFree = sqlite3GetTempReg(pParse);
3253 sqlite3ExprCode(pParse, pList->a[ii].pExpr, r2);
3254 sqlite3VdbeAddOp4(v, OP_Affinity, r2, 1, 0, "E", P4_STATIC);
3255 }else{
3256 r2 = sqlite3ExprCodeTemp(pParse, pList->a[ii].pExpr, ®ToFree);
3257 }
3258 if( regCkNull && sqlite3ExprCanBeNull(pList->a[ii].pExpr) ){
3259 sqlite3VdbeAddOp3(v, OP_BitAnd, regCkNull, r2, regCkNull);
3260 }
3261 sqlite3ReleaseTempReg(pParse, regToFree);
3262 if( ii<pList->nExpr-1 || destIfNull!=destIfFalse ){
3263 int op = rLhs!=r2 ? OP_Eq : OP_NotNull;
3264 sqlite3VdbeAddOp4(v, op, rLhs, labelOk, r2,
3265 (void*)pColl, P4_COLLSEQ);
3266 VdbeCoverageIf(v, ii<pList->nExpr-1 && op==OP_Eq);
3267 VdbeCoverageIf(v, ii==pList->nExpr-1 && op==OP_Eq);
3268 VdbeCoverageIf(v, ii<pList->nExpr-1 && op==OP_NotNull);
3269 VdbeCoverageIf(v, ii==pList->nExpr-1 && op==OP_NotNull);
3270 sqlite3VdbeChangeP5(v, zAff[0]);
3271 }else{
3272 int op = rLhs!=r2 ? OP_Ne : OP_IsNull;
3273 assert( destIfNull==destIfFalse );
3274 sqlite3VdbeAddOp4(v, op, rLhs, destIfFalse, r2,
3275 (void*)pColl, P4_COLLSEQ);
3276 VdbeCoverageIf(v, op==OP_Ne);
3277 VdbeCoverageIf(v, op==OP_IsNull);
3278 sqlite3VdbeChangeP5(v, zAff[0] | SQLITE_JUMPIFNULL);
3279 }
3280 }
3281 if( regCkNull ){
3282 sqlite3VdbeAddOp2(v, OP_IsNull, regCkNull, destIfNull); VdbeCoverage(v);
3283 sqlite3VdbeGoto(v, destIfFalse);
3284 }
3285 sqlite3VdbeResolveLabel(v, labelOk);
3286 sqlite3ReleaseTempReg(pParse, regCkNull);
3287 goto sqlite3ExprCodeIN_finished;
3288 }
3289
3290 /* Step 2: Check to see if the LHS contains any NULL columns. If the
3291 ** LHS does contain NULLs then the result must be either FALSE or NULL.
3292 ** We will then skip the binary search of the RHS.
3293 */
3294 if( destIfNull==destIfFalse ){
3295 destStep2 = destIfFalse;
3296 }else{
3297 destStep2 = destStep6 = sqlite3VdbeMakeLabel(pParse);
3298 }
3299 if( pParse->nErr ) goto sqlite3ExprCodeIN_finished;
3300 for(i=0; i<nVector; i++){
3301 Expr *p = sqlite3VectorFieldSubexpr(pExpr->pLeft, i);
3302 if( sqlite3ExprCanBeNull(p) ){
3303 sqlite3VdbeAddOp2(v, OP_IsNull, rLhs+i, destStep2);
3304 VdbeCoverage(v);
3305 }
3306 }
3307
3308 /* Step 3. The LHS is now known to be non-NULL. Do the binary search
3309 ** of the RHS using the LHS as a probe. If found, the result is
3310 ** true.
3311 */
3312 if( eType==IN_INDEX_ROWID ){
3313 /* In this case, the RHS is the ROWID of table b-tree and so we also
3314 ** know that the RHS is non-NULL. Hence, we combine steps 3 and 4
3315 ** into a single opcode. */
3316 sqlite3VdbeAddOp3(v, OP_SeekRowid, iTab, destIfFalse, rLhs);
3317 VdbeCoverage(v);
3318 addrTruthOp = sqlite3VdbeAddOp0(v, OP_Goto); /* Return True */
3319 }else{
3320 sqlite3VdbeAddOp4(v, OP_Affinity, rLhs, nVector, 0, zAff, nVector);
3321 if( destIfFalse==destIfNull ){
3322 /* Combine Step 3 and Step 5 into a single opcode */
3323 sqlite3VdbeAddOp4Int(v, OP_NotFound, iTab, destIfFalse,
3324 rLhs, nVector); VdbeCoverage(v);
3325 goto sqlite3ExprCodeIN_finished;
3326 }
3327 /* Ordinary Step 3, for the case where FALSE and NULL are distinct */
3328 addrTruthOp = sqlite3VdbeAddOp4Int(v, OP_Found, iTab, 0,
3329 rLhs, nVector); VdbeCoverage(v);
3330 }
3331
3332 /* Step 4. If the RHS is known to be non-NULL and we did not find
3333 ** an match on the search above, then the result must be FALSE.
3334 */
3335 if( rRhsHasNull && nVector==1 ){
3336 sqlite3VdbeAddOp2(v, OP_NotNull, rRhsHasNull, destIfFalse);
3337 VdbeCoverage(v);
3338 }
3339
3340 /* Step 5. If we do not care about the difference between NULL and
3341 ** FALSE, then just return false.
3342 */
3343 if( destIfFalse==destIfNull ) sqlite3VdbeGoto(v, destIfFalse);
3344
3345 /* Step 6: Loop through rows of the RHS. Compare each row to the LHS.
3346 ** If any comparison is NULL, then the result is NULL. If all
3347 ** comparisons are FALSE then the final result is FALSE.
3348 **
3349 ** For a scalar LHS, it is sufficient to check just the first row
3350 ** of the RHS.
3351 */
3352 if( destStep6 ) sqlite3VdbeResolveLabel(v, destStep6);
3353 addrTop = sqlite3VdbeAddOp2(v, OP_Rewind, iTab, destIfFalse);
3354 VdbeCoverage(v);
3355 if( nVector>1 ){
3356 destNotNull = sqlite3VdbeMakeLabel(pParse);
3357 }else{
3358 /* For nVector==1, combine steps 6 and 7 by immediately returning
3359 ** FALSE if the first comparison is not NULL */
3360 destNotNull = destIfFalse;
3361 }
3362 for(i=0; i<nVector; i++){
3363 Expr *p;
3364 CollSeq *pColl;
3365 int r3 = sqlite3GetTempReg(pParse);
3366 p = sqlite3VectorFieldSubexpr(pLeft, i);
3367 pColl = sqlite3ExprCollSeq(pParse, p);
3368 sqlite3VdbeAddOp3(v, OP_Column, iTab, i, r3);
3369 sqlite3VdbeAddOp4(v, OP_Ne, rLhs+i, destNotNull, r3,
3370 (void*)pColl, P4_COLLSEQ);
3371 VdbeCoverage(v);
3372 sqlite3ReleaseTempReg(pParse, r3);
3373 }
3374 sqlite3VdbeAddOp2(v, OP_Goto, 0, destIfNull);
3375 if( nVector>1 ){
3376 sqlite3VdbeResolveLabel(v, destNotNull);
3377 sqlite3VdbeAddOp2(v, OP_Next, iTab, addrTop+1);
3378 VdbeCoverage(v);
3379
3380 /* Step 7: If we reach this point, we know that the result must
3381 ** be false. */
3382 sqlite3VdbeAddOp2(v, OP_Goto, 0, destIfFalse);
3383 }
3384
3385 /* Jumps here in order to return true. */
3386 sqlite3VdbeJumpHere(v, addrTruthOp);
3387
3388 sqlite3ExprCodeIN_finished:
3389 if( rLhs!=rLhsOrig ) sqlite3ReleaseTempReg(pParse, rLhs);
3390 VdbeComment((v, "end IN expr"));
3391 sqlite3ExprCodeIN_oom_error:
3392 sqlite3DbFree(pParse->db, aiMap);
3393 sqlite3DbFree(pParse->db, zAff);
3394 }
3395 #endif /* SQLITE_OMIT_SUBQUERY */
3396
3397 #ifndef SQLITE_OMIT_FLOATING_POINT
3398 /*
3399 ** Generate an instruction that will put the floating point
3400 ** value described by z[0..n-1] into register iMem.
3401 **
3402 ** The z[] string will probably not be zero-terminated. But the
3403 ** z[n] character is guaranteed to be something that does not look
3404 ** like the continuation of the number.
3405 */
codeReal(Vdbe * v,const char * z,int negateFlag,int iMem)3406 static void codeReal(Vdbe *v, const char *z, int negateFlag, int iMem){
3407 if( ALWAYS(z!=0) ){
3408 double value;
3409 sqlite3AtoF(z, &value, sqlite3Strlen30(z), SQLITE_UTF8);
3410 assert( !sqlite3IsNaN(value) ); /* The new AtoF never returns NaN */
3411 if( negateFlag ) value = -value;
3412 sqlite3VdbeAddOp4Dup8(v, OP_Real, 0, iMem, 0, (u8*)&value, P4_REAL);
3413 }
3414 }
3415 #endif
3416
3417
3418 /*
3419 ** Generate an instruction that will put the integer describe by
3420 ** text z[0..n-1] into register iMem.
3421 **
3422 ** Expr.u.zToken is always UTF8 and zero-terminated.
3423 */
codeInteger(Parse * pParse,Expr * pExpr,int negFlag,int iMem)3424 static void codeInteger(Parse *pParse, Expr *pExpr, int negFlag, int iMem){
3425 Vdbe *v = pParse->pVdbe;
3426 if( pExpr->flags & EP_IntValue ){
3427 int i = pExpr->u.iValue;
3428 assert( i>=0 );
3429 if( negFlag ) i = -i;
3430 sqlite3VdbeAddOp2(v, OP_Integer, i, iMem);
3431 }else{
3432 int c;
3433 i64 value;
3434 const char *z = pExpr->u.zToken;
3435 assert( z!=0 );
3436 c = sqlite3DecOrHexToI64(z, &value);
3437 if( (c==3 && !negFlag) || (c==2) || (negFlag && value==SMALLEST_INT64)){
3438 #ifdef SQLITE_OMIT_FLOATING_POINT
3439 sqlite3ErrorMsg(pParse, "oversized integer: %s%s", negFlag ? "-" : "", z);
3440 #else
3441 #ifndef SQLITE_OMIT_HEX_INTEGER
3442 if( sqlite3_strnicmp(z,"0x",2)==0 ){
3443 sqlite3ErrorMsg(pParse, "hex literal too big: %s%s", negFlag?"-":"",z);
3444 }else
3445 #endif
3446 {
3447 codeReal(v, z, negFlag, iMem);
3448 }
3449 #endif
3450 }else{
3451 if( negFlag ){ value = c==3 ? SMALLEST_INT64 : -value; }
3452 sqlite3VdbeAddOp4Dup8(v, OP_Int64, 0, iMem, 0, (u8*)&value, P4_INT64);
3453 }
3454 }
3455 }
3456
3457
3458 /* Generate code that will load into register regOut a value that is
3459 ** appropriate for the iIdxCol-th column of index pIdx.
3460 */
sqlite3ExprCodeLoadIndexColumn(Parse * pParse,Index * pIdx,int iTabCur,int iIdxCol,int regOut)3461 void sqlite3ExprCodeLoadIndexColumn(
3462 Parse *pParse, /* The parsing context */
3463 Index *pIdx, /* The index whose column is to be loaded */
3464 int iTabCur, /* Cursor pointing to a table row */
3465 int iIdxCol, /* The column of the index to be loaded */
3466 int regOut /* Store the index column value in this register */
3467 ){
3468 i16 iTabCol = pIdx->aiColumn[iIdxCol];
3469 if( iTabCol==XN_EXPR ){
3470 assert( pIdx->aColExpr );
3471 assert( pIdx->aColExpr->nExpr>iIdxCol );
3472 pParse->iSelfTab = iTabCur + 1;
3473 sqlite3ExprCodeCopy(pParse, pIdx->aColExpr->a[iIdxCol].pExpr, regOut);
3474 pParse->iSelfTab = 0;
3475 }else{
3476 sqlite3ExprCodeGetColumnOfTable(pParse->pVdbe, pIdx->pTable, iTabCur,
3477 iTabCol, regOut);
3478 }
3479 }
3480
3481 #ifndef SQLITE_OMIT_GENERATED_COLUMNS
3482 /*
3483 ** Generate code that will compute the value of generated column pCol
3484 ** and store the result in register regOut
3485 */
sqlite3ExprCodeGeneratedColumn(Parse * pParse,Column * pCol,int regOut)3486 void sqlite3ExprCodeGeneratedColumn(
3487 Parse *pParse,
3488 Column *pCol,
3489 int regOut
3490 ){
3491 int iAddr;
3492 Vdbe *v = pParse->pVdbe;
3493 assert( v!=0 );
3494 assert( pParse->iSelfTab!=0 );
3495 if( pParse->iSelfTab>0 ){
3496 iAddr = sqlite3VdbeAddOp3(v, OP_IfNullRow, pParse->iSelfTab-1, 0, regOut);
3497 }else{
3498 iAddr = 0;
3499 }
3500 sqlite3ExprCodeCopy(pParse, pCol->pDflt, regOut);
3501 if( pCol->affinity>=SQLITE_AFF_TEXT ){
3502 sqlite3VdbeAddOp4(v, OP_Affinity, regOut, 1, 0, &pCol->affinity, 1);
3503 }
3504 if( iAddr ) sqlite3VdbeJumpHere(v, iAddr);
3505 }
3506 #endif /* SQLITE_OMIT_GENERATED_COLUMNS */
3507
3508 /*
3509 ** Generate code to extract the value of the iCol-th column of a table.
3510 */
sqlite3ExprCodeGetColumnOfTable(Vdbe * v,Table * pTab,int iTabCur,int iCol,int regOut)3511 void sqlite3ExprCodeGetColumnOfTable(
3512 Vdbe *v, /* Parsing context */
3513 Table *pTab, /* The table containing the value */
3514 int iTabCur, /* The table cursor. Or the PK cursor for WITHOUT ROWID */
3515 int iCol, /* Index of the column to extract */
3516 int regOut /* Extract the value into this register */
3517 ){
3518 Column *pCol;
3519 assert( v!=0 );
3520 if( pTab==0 ){
3521 sqlite3VdbeAddOp3(v, OP_Column, iTabCur, iCol, regOut);
3522 return;
3523 }
3524 if( iCol<0 || iCol==pTab->iPKey ){
3525 sqlite3VdbeAddOp2(v, OP_Rowid, iTabCur, regOut);
3526 }else{
3527 int op;
3528 int x;
3529 if( IsVirtual(pTab) ){
3530 op = OP_VColumn;
3531 x = iCol;
3532 #ifndef SQLITE_OMIT_GENERATED_COLUMNS
3533 }else if( (pCol = &pTab->aCol[iCol])->colFlags & COLFLAG_VIRTUAL ){
3534 Parse *pParse = sqlite3VdbeParser(v);
3535 if( pCol->colFlags & COLFLAG_BUSY ){
3536 sqlite3ErrorMsg(pParse, "generated column loop on \"%s\"", pCol->zName);
3537 }else{
3538 int savedSelfTab = pParse->iSelfTab;
3539 pCol->colFlags |= COLFLAG_BUSY;
3540 pParse->iSelfTab = iTabCur+1;
3541 sqlite3ExprCodeGeneratedColumn(pParse, pCol, regOut);
3542 pParse->iSelfTab = savedSelfTab;
3543 pCol->colFlags &= ~COLFLAG_BUSY;
3544 }
3545 return;
3546 #endif
3547 }else if( !HasRowid(pTab) ){
3548 testcase( iCol!=sqlite3TableColumnToStorage(pTab, iCol) );
3549 x = sqlite3TableColumnToIndex(sqlite3PrimaryKeyIndex(pTab), iCol);
3550 op = OP_Column;
3551 }else{
3552 x = sqlite3TableColumnToStorage(pTab,iCol);
3553 testcase( x!=iCol );
3554 op = OP_Column;
3555 }
3556 sqlite3VdbeAddOp3(v, op, iTabCur, x, regOut);
3557 sqlite3ColumnDefault(v, pTab, iCol, regOut);
3558 }
3559 }
3560
3561 /*
3562 ** Generate code that will extract the iColumn-th column from
3563 ** table pTab and store the column value in register iReg.
3564 **
3565 ** There must be an open cursor to pTab in iTable when this routine
3566 ** is called. If iColumn<0 then code is generated that extracts the rowid.
3567 */
sqlite3ExprCodeGetColumn(Parse * pParse,Table * pTab,int iColumn,int iTable,int iReg,u8 p5)3568 int sqlite3ExprCodeGetColumn(
3569 Parse *pParse, /* Parsing and code generating context */
3570 Table *pTab, /* Description of the table we are reading from */
3571 int iColumn, /* Index of the table column */
3572 int iTable, /* The cursor pointing to the table */
3573 int iReg, /* Store results here */
3574 u8 p5 /* P5 value for OP_Column + FLAGS */
3575 ){
3576 assert( pParse->pVdbe!=0 );
3577 sqlite3ExprCodeGetColumnOfTable(pParse->pVdbe, pTab, iTable, iColumn, iReg);
3578 if( p5 ){
3579 VdbeOp *pOp = sqlite3VdbeGetOp(pParse->pVdbe,-1);
3580 if( pOp->opcode==OP_Column ) pOp->p5 = p5;
3581 }
3582 return iReg;
3583 }
3584
3585 /*
3586 ** Generate code to move content from registers iFrom...iFrom+nReg-1
3587 ** over to iTo..iTo+nReg-1.
3588 */
sqlite3ExprCodeMove(Parse * pParse,int iFrom,int iTo,int nReg)3589 void sqlite3ExprCodeMove(Parse *pParse, int iFrom, int iTo, int nReg){
3590 sqlite3VdbeAddOp3(pParse->pVdbe, OP_Move, iFrom, iTo, nReg);
3591 }
3592
3593 /*
3594 ** Convert a scalar expression node to a TK_REGISTER referencing
3595 ** register iReg. The caller must ensure that iReg already contains
3596 ** the correct value for the expression.
3597 */
exprToRegister(Expr * pExpr,int iReg)3598 static void exprToRegister(Expr *pExpr, int iReg){
3599 Expr *p = sqlite3ExprSkipCollateAndLikely(pExpr);
3600 p->op2 = p->op;
3601 p->op = TK_REGISTER;
3602 p->iTable = iReg;
3603 ExprClearProperty(p, EP_Skip);
3604 }
3605
3606 /*
3607 ** Evaluate an expression (either a vector or a scalar expression) and store
3608 ** the result in continguous temporary registers. Return the index of
3609 ** the first register used to store the result.
3610 **
3611 ** If the returned result register is a temporary scalar, then also write
3612 ** that register number into *piFreeable. If the returned result register
3613 ** is not a temporary or if the expression is a vector set *piFreeable
3614 ** to 0.
3615 */
exprCodeVector(Parse * pParse,Expr * p,int * piFreeable)3616 static int exprCodeVector(Parse *pParse, Expr *p, int *piFreeable){
3617 int iResult;
3618 int nResult = sqlite3ExprVectorSize(p);
3619 if( nResult==1 ){
3620 iResult = sqlite3ExprCodeTemp(pParse, p, piFreeable);
3621 }else{
3622 *piFreeable = 0;
3623 if( p->op==TK_SELECT ){
3624 #if SQLITE_OMIT_SUBQUERY
3625 iResult = 0;
3626 #else
3627 iResult = sqlite3CodeSubselect(pParse, p);
3628 #endif
3629 }else{
3630 int i;
3631 iResult = pParse->nMem+1;
3632 pParse->nMem += nResult;
3633 for(i=0; i<nResult; i++){
3634 sqlite3ExprCodeFactorable(pParse, p->x.pList->a[i].pExpr, i+iResult);
3635 }
3636 }
3637 }
3638 return iResult;
3639 }
3640
3641 /*
3642 ** Generate code to implement special SQL functions that are implemented
3643 ** in-line rather than by using the usual callbacks.
3644 */
exprCodeInlineFunction(Parse * pParse,ExprList * pFarg,int iFuncId,int target)3645 static int exprCodeInlineFunction(
3646 Parse *pParse, /* Parsing context */
3647 ExprList *pFarg, /* List of function arguments */
3648 int iFuncId, /* Function ID. One of the INTFUNC_... values */
3649 int target /* Store function result in this register */
3650 ){
3651 int nFarg;
3652 Vdbe *v = pParse->pVdbe;
3653 assert( v!=0 );
3654 assert( pFarg!=0 );
3655 nFarg = pFarg->nExpr;
3656 assert( nFarg>0 ); /* All in-line functions have at least one argument */
3657 switch( iFuncId ){
3658 case INLINEFUNC_coalesce: {
3659 /* Attempt a direct implementation of the built-in COALESCE() and
3660 ** IFNULL() functions. This avoids unnecessary evaluation of
3661 ** arguments past the first non-NULL argument.
3662 */
3663 int endCoalesce = sqlite3VdbeMakeLabel(pParse);
3664 int i;
3665 assert( nFarg>=2 );
3666 sqlite3ExprCode(pParse, pFarg->a[0].pExpr, target);
3667 for(i=1; i<nFarg; i++){
3668 sqlite3VdbeAddOp2(v, OP_NotNull, target, endCoalesce);
3669 VdbeCoverage(v);
3670 sqlite3ExprCode(pParse, pFarg->a[i].pExpr, target);
3671 }
3672 if( sqlite3VdbeGetOp(v, -1)->opcode==OP_Copy ){
3673 sqlite3VdbeChangeP5(v, 1); /* Tag trailing OP_Copy as not mergable */
3674 }
3675 sqlite3VdbeResolveLabel(v, endCoalesce);
3676 break;
3677 }
3678
3679 default: {
3680 /* The UNLIKELY() function is a no-op. The result is the value
3681 ** of the first argument.
3682 */
3683 assert( nFarg==1 || nFarg==2 );
3684 target = sqlite3ExprCodeTarget(pParse, pFarg->a[0].pExpr, target);
3685 break;
3686 }
3687
3688 /***********************************************************************
3689 ** Test-only SQL functions that are only usable if enabled
3690 ** via SQLITE_TESTCTRL_INTERNAL_FUNCTIONS
3691 */
3692 case INLINEFUNC_expr_compare: {
3693 /* Compare two expressions using sqlite3ExprCompare() */
3694 assert( nFarg==2 );
3695 sqlite3VdbeAddOp2(v, OP_Integer,
3696 sqlite3ExprCompare(0,pFarg->a[0].pExpr, pFarg->a[1].pExpr,-1),
3697 target);
3698 break;
3699 }
3700
3701 case INLINEFUNC_expr_implies_expr: {
3702 /* Compare two expressions using sqlite3ExprImpliesExpr() */
3703 assert( nFarg==2 );
3704 sqlite3VdbeAddOp2(v, OP_Integer,
3705 sqlite3ExprImpliesExpr(pParse,pFarg->a[0].pExpr, pFarg->a[1].pExpr,-1),
3706 target);
3707 break;
3708 }
3709
3710 case INLINEFUNC_implies_nonnull_row: {
3711 /* REsult of sqlite3ExprImpliesNonNullRow() */
3712 Expr *pA1;
3713 assert( nFarg==2 );
3714 pA1 = pFarg->a[1].pExpr;
3715 if( pA1->op==TK_COLUMN ){
3716 sqlite3VdbeAddOp2(v, OP_Integer,
3717 sqlite3ExprImpliesNonNullRow(pFarg->a[0].pExpr,pA1->iTable),
3718 target);
3719 }else{
3720 sqlite3VdbeAddOp2(v, OP_Null, 0, target);
3721 }
3722 break;
3723 }
3724
3725 #ifdef SQLITE_DEBUG
3726 case INLINEFUNC_affinity: {
3727 /* The AFFINITY() function evaluates to a string that describes
3728 ** the type affinity of the argument. This is used for testing of
3729 ** the SQLite type logic.
3730 */
3731 const char *azAff[] = { "blob", "text", "numeric", "integer", "real" };
3732 char aff;
3733 assert( nFarg==1 );
3734 aff = sqlite3ExprAffinity(pFarg->a[0].pExpr);
3735 sqlite3VdbeLoadString(v, target,
3736 (aff<=SQLITE_AFF_NONE) ? "none" : azAff[aff-SQLITE_AFF_BLOB]);
3737 break;
3738 }
3739 #endif
3740 }
3741 return target;
3742 }
3743
3744
3745 /*
3746 ** Generate code into the current Vdbe to evaluate the given
3747 ** expression. Attempt to store the results in register "target".
3748 ** Return the register where results are stored.
3749 **
3750 ** With this routine, there is no guarantee that results will
3751 ** be stored in target. The result might be stored in some other
3752 ** register if it is convenient to do so. The calling function
3753 ** must check the return code and move the results to the desired
3754 ** register.
3755 */
sqlite3ExprCodeTarget(Parse * pParse,Expr * pExpr,int target)3756 int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target){
3757 Vdbe *v = pParse->pVdbe; /* The VM under construction */
3758 int op; /* The opcode being coded */
3759 int inReg = target; /* Results stored in register inReg */
3760 int regFree1 = 0; /* If non-zero free this temporary register */
3761 int regFree2 = 0; /* If non-zero free this temporary register */
3762 int r1, r2; /* Various register numbers */
3763 Expr tempX; /* Temporary expression node */
3764 int p5 = 0;
3765
3766 assert( target>0 && target<=pParse->nMem );
3767 if( v==0 ){
3768 assert( pParse->db->mallocFailed );
3769 return 0;
3770 }
3771
3772 expr_code_doover:
3773 if( pExpr==0 ){
3774 op = TK_NULL;
3775 }else{
3776 op = pExpr->op;
3777 }
3778 switch( op ){
3779 case TK_AGG_COLUMN: {
3780 AggInfo *pAggInfo = pExpr->pAggInfo;
3781 struct AggInfo_col *pCol = &pAggInfo->aCol[pExpr->iAgg];
3782 if( !pAggInfo->directMode ){
3783 assert( pCol->iMem>0 );
3784 return pCol->iMem;
3785 }else if( pAggInfo->useSortingIdx ){
3786 sqlite3VdbeAddOp3(v, OP_Column, pAggInfo->sortingIdxPTab,
3787 pCol->iSorterColumn, target);
3788 return target;
3789 }
3790 /* Otherwise, fall thru into the TK_COLUMN case */
3791 }
3792 case TK_COLUMN: {
3793 int iTab = pExpr->iTable;
3794 int iReg;
3795 if( ExprHasProperty(pExpr, EP_FixedCol) ){
3796 /* This COLUMN expression is really a constant due to WHERE clause
3797 ** constraints, and that constant is coded by the pExpr->pLeft
3798 ** expresssion. However, make sure the constant has the correct
3799 ** datatype by applying the Affinity of the table column to the
3800 ** constant.
3801 */
3802 int aff;
3803 iReg = sqlite3ExprCodeTarget(pParse, pExpr->pLeft,target);
3804 if( pExpr->y.pTab ){
3805 aff = sqlite3TableColumnAffinity(pExpr->y.pTab, pExpr->iColumn);
3806 }else{
3807 aff = pExpr->affExpr;
3808 }
3809 if( aff>SQLITE_AFF_BLOB ){
3810 static const char zAff[] = "B\000C\000D\000E";
3811 assert( SQLITE_AFF_BLOB=='A' );
3812 assert( SQLITE_AFF_TEXT=='B' );
3813 if( iReg!=target ){
3814 sqlite3VdbeAddOp2(v, OP_SCopy, iReg, target);
3815 iReg = target;
3816 }
3817 sqlite3VdbeAddOp4(v, OP_Affinity, iReg, 1, 0,
3818 &zAff[(aff-'B')*2], P4_STATIC);
3819 }
3820 return iReg;
3821 }
3822 if( iTab<0 ){
3823 if( pParse->iSelfTab<0 ){
3824 /* Other columns in the same row for CHECK constraints or
3825 ** generated columns or for inserting into partial index.
3826 ** The row is unpacked into registers beginning at
3827 ** 0-(pParse->iSelfTab). The rowid (if any) is in a register
3828 ** immediately prior to the first column.
3829 */
3830 Column *pCol;
3831 Table *pTab = pExpr->y.pTab;
3832 int iSrc;
3833 int iCol = pExpr->iColumn;
3834 assert( pTab!=0 );
3835 assert( iCol>=XN_ROWID );
3836 assert( iCol<pTab->nCol );
3837 if( iCol<0 ){
3838 return -1-pParse->iSelfTab;
3839 }
3840 pCol = pTab->aCol + iCol;
3841 testcase( iCol!=sqlite3TableColumnToStorage(pTab,iCol) );
3842 iSrc = sqlite3TableColumnToStorage(pTab, iCol) - pParse->iSelfTab;
3843 #ifndef SQLITE_OMIT_GENERATED_COLUMNS
3844 if( pCol->colFlags & COLFLAG_GENERATED ){
3845 if( pCol->colFlags & COLFLAG_BUSY ){
3846 sqlite3ErrorMsg(pParse, "generated column loop on \"%s\"",
3847 pCol->zName);
3848 return 0;
3849 }
3850 pCol->colFlags |= COLFLAG_BUSY;
3851 if( pCol->colFlags & COLFLAG_NOTAVAIL ){
3852 sqlite3ExprCodeGeneratedColumn(pParse, pCol, iSrc);
3853 }
3854 pCol->colFlags &= ~(COLFLAG_BUSY|COLFLAG_NOTAVAIL);
3855 return iSrc;
3856 }else
3857 #endif /* SQLITE_OMIT_GENERATED_COLUMNS */
3858 if( pCol->affinity==SQLITE_AFF_REAL ){
3859 sqlite3VdbeAddOp2(v, OP_SCopy, iSrc, target);
3860 sqlite3VdbeAddOp1(v, OP_RealAffinity, target);
3861 return target;
3862 }else{
3863 return iSrc;
3864 }
3865 }else{
3866 /* Coding an expression that is part of an index where column names
3867 ** in the index refer to the table to which the index belongs */
3868 iTab = pParse->iSelfTab - 1;
3869 }
3870 }
3871 iReg = sqlite3ExprCodeGetColumn(pParse, pExpr->y.pTab,
3872 pExpr->iColumn, iTab, target,
3873 pExpr->op2);
3874 if( pExpr->y.pTab==0 && pExpr->affExpr==SQLITE_AFF_REAL ){
3875 sqlite3VdbeAddOp1(v, OP_RealAffinity, iReg);
3876 }
3877 return iReg;
3878 }
3879 case TK_INTEGER: {
3880 codeInteger(pParse, pExpr, 0, target);
3881 return target;
3882 }
3883 case TK_TRUEFALSE: {
3884 sqlite3VdbeAddOp2(v, OP_Integer, sqlite3ExprTruthValue(pExpr), target);
3885 return target;
3886 }
3887 #ifndef SQLITE_OMIT_FLOATING_POINT
3888 case TK_FLOAT: {
3889 assert( !ExprHasProperty(pExpr, EP_IntValue) );
3890 codeReal(v, pExpr->u.zToken, 0, target);
3891 return target;
3892 }
3893 #endif
3894 case TK_STRING: {
3895 assert( !ExprHasProperty(pExpr, EP_IntValue) );
3896 sqlite3VdbeLoadString(v, target, pExpr->u.zToken);
3897 return target;
3898 }
3899 default: {
3900 /* Make NULL the default case so that if a bug causes an illegal
3901 ** Expr node to be passed into this function, it will be handled
3902 ** sanely and not crash. But keep the assert() to bring the problem
3903 ** to the attention of the developers. */
3904 assert( op==TK_NULL );
3905 sqlite3VdbeAddOp2(v, OP_Null, 0, target);
3906 return target;
3907 }
3908 #ifndef SQLITE_OMIT_BLOB_LITERAL
3909 case TK_BLOB: {
3910 int n;
3911 const char *z;
3912 char *zBlob;
3913 assert( !ExprHasProperty(pExpr, EP_IntValue) );
3914 assert( pExpr->u.zToken[0]=='x' || pExpr->u.zToken[0]=='X' );
3915 assert( pExpr->u.zToken[1]=='\'' );
3916 z = &pExpr->u.zToken[2];
3917 n = sqlite3Strlen30(z) - 1;
3918 assert( z[n]=='\'' );
3919 zBlob = sqlite3HexToBlob(sqlite3VdbeDb(v), z, n);
3920 sqlite3VdbeAddOp4(v, OP_Blob, n/2, target, 0, zBlob, P4_DYNAMIC);
3921 return target;
3922 }
3923 #endif
3924 case TK_VARIABLE: {
3925 assert( !ExprHasProperty(pExpr, EP_IntValue) );
3926 assert( pExpr->u.zToken!=0 );
3927 assert( pExpr->u.zToken[0]!=0 );
3928 sqlite3VdbeAddOp2(v, OP_Variable, pExpr->iColumn, target);
3929 if( pExpr->u.zToken[1]!=0 ){
3930 const char *z = sqlite3VListNumToName(pParse->pVList, pExpr->iColumn);
3931 assert( pExpr->u.zToken[0]=='?' || (z && !strcmp(pExpr->u.zToken, z)) );
3932 pParse->pVList[0] = 0; /* Indicate VList may no longer be enlarged */
3933 sqlite3VdbeAppendP4(v, (char*)z, P4_STATIC);
3934 }
3935 return target;
3936 }
3937 case TK_REGISTER: {
3938 return pExpr->iTable;
3939 }
3940 #ifndef SQLITE_OMIT_CAST
3941 case TK_CAST: {
3942 /* Expressions of the form: CAST(pLeft AS token) */
3943 inReg = sqlite3ExprCodeTarget(pParse, pExpr->pLeft, target);
3944 if( inReg!=target ){
3945 sqlite3VdbeAddOp2(v, OP_SCopy, inReg, target);
3946 inReg = target;
3947 }
3948 sqlite3VdbeAddOp2(v, OP_Cast, target,
3949 sqlite3AffinityType(pExpr->u.zToken, 0));
3950 return inReg;
3951 }
3952 #endif /* SQLITE_OMIT_CAST */
3953 case TK_IS:
3954 case TK_ISNOT:
3955 op = (op==TK_IS) ? TK_EQ : TK_NE;
3956 p5 = SQLITE_NULLEQ;
3957 /* fall-through */
3958 case TK_LT:
3959 case TK_LE:
3960 case TK_GT:
3961 case TK_GE:
3962 case TK_NE:
3963 case TK_EQ: {
3964 Expr *pLeft = pExpr->pLeft;
3965 if( sqlite3ExprIsVector(pLeft) ){
3966 codeVectorCompare(pParse, pExpr, target, op, p5);
3967 }else{
3968 r1 = sqlite3ExprCodeTemp(pParse, pLeft, ®Free1);
3969 r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, ®Free2);
3970 codeCompare(pParse, pLeft, pExpr->pRight, op,
3971 r1, r2, inReg, SQLITE_STOREP2 | p5,
3972 ExprHasProperty(pExpr,EP_Commuted));
3973 assert(TK_LT==OP_Lt); testcase(op==OP_Lt); VdbeCoverageIf(v,op==OP_Lt);
3974 assert(TK_LE==OP_Le); testcase(op==OP_Le); VdbeCoverageIf(v,op==OP_Le);
3975 assert(TK_GT==OP_Gt); testcase(op==OP_Gt); VdbeCoverageIf(v,op==OP_Gt);
3976 assert(TK_GE==OP_Ge); testcase(op==OP_Ge); VdbeCoverageIf(v,op==OP_Ge);
3977 assert(TK_EQ==OP_Eq); testcase(op==OP_Eq); VdbeCoverageIf(v,op==OP_Eq);
3978 assert(TK_NE==OP_Ne); testcase(op==OP_Ne); VdbeCoverageIf(v,op==OP_Ne);
3979 testcase( regFree1==0 );
3980 testcase( regFree2==0 );
3981 }
3982 break;
3983 }
3984 case TK_AND:
3985 case TK_OR:
3986 case TK_PLUS:
3987 case TK_STAR:
3988 case TK_MINUS:
3989 case TK_REM:
3990 case TK_BITAND:
3991 case TK_BITOR:
3992 case TK_SLASH:
3993 case TK_LSHIFT:
3994 case TK_RSHIFT:
3995 case TK_CONCAT: {
3996 assert( TK_AND==OP_And ); testcase( op==TK_AND );
3997 assert( TK_OR==OP_Or ); testcase( op==TK_OR );
3998 assert( TK_PLUS==OP_Add ); testcase( op==TK_PLUS );
3999 assert( TK_MINUS==OP_Subtract ); testcase( op==TK_MINUS );
4000 assert( TK_REM==OP_Remainder ); testcase( op==TK_REM );
4001 assert( TK_BITAND==OP_BitAnd ); testcase( op==TK_BITAND );
4002 assert( TK_BITOR==OP_BitOr ); testcase( op==TK_BITOR );
4003 assert( TK_SLASH==OP_Divide ); testcase( op==TK_SLASH );
4004 assert( TK_LSHIFT==OP_ShiftLeft ); testcase( op==TK_LSHIFT );
4005 assert( TK_RSHIFT==OP_ShiftRight ); testcase( op==TK_RSHIFT );
4006 assert( TK_CONCAT==OP_Concat ); testcase( op==TK_CONCAT );
4007 r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free1);
4008 r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, ®Free2);
4009 sqlite3VdbeAddOp3(v, op, r2, r1, target);
4010 testcase( regFree1==0 );
4011 testcase( regFree2==0 );
4012 break;
4013 }
4014 case TK_UMINUS: {
4015 Expr *pLeft = pExpr->pLeft;
4016 assert( pLeft );
4017 if( pLeft->op==TK_INTEGER ){
4018 codeInteger(pParse, pLeft, 1, target);
4019 return target;
4020 #ifndef SQLITE_OMIT_FLOATING_POINT
4021 }else if( pLeft->op==TK_FLOAT ){
4022 assert( !ExprHasProperty(pExpr, EP_IntValue) );
4023 codeReal(v, pLeft->u.zToken, 1, target);
4024 return target;
4025 #endif
4026 }else{
4027 tempX.op = TK_INTEGER;
4028 tempX.flags = EP_IntValue|EP_TokenOnly;
4029 tempX.u.iValue = 0;
4030 r1 = sqlite3ExprCodeTemp(pParse, &tempX, ®Free1);
4031 r2 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free2);
4032 sqlite3VdbeAddOp3(v, OP_Subtract, r2, r1, target);
4033 testcase( regFree2==0 );
4034 }
4035 break;
4036 }
4037 case TK_BITNOT:
4038 case TK_NOT: {
4039 assert( TK_BITNOT==OP_BitNot ); testcase( op==TK_BITNOT );
4040 assert( TK_NOT==OP_Not ); testcase( op==TK_NOT );
4041 r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free1);
4042 testcase( regFree1==0 );
4043 sqlite3VdbeAddOp2(v, op, r1, inReg);
4044 break;
4045 }
4046 case TK_TRUTH: {
4047 int isTrue; /* IS TRUE or IS NOT TRUE */
4048 int bNormal; /* IS TRUE or IS FALSE */
4049 r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free1);
4050 testcase( regFree1==0 );
4051 isTrue = sqlite3ExprTruthValue(pExpr->pRight);
4052 bNormal = pExpr->op2==TK_IS;
4053 testcase( isTrue && bNormal);
4054 testcase( !isTrue && bNormal);
4055 sqlite3VdbeAddOp4Int(v, OP_IsTrue, r1, inReg, !isTrue, isTrue ^ bNormal);
4056 break;
4057 }
4058 case TK_ISNULL:
4059 case TK_NOTNULL: {
4060 int addr;
4061 assert( TK_ISNULL==OP_IsNull ); testcase( op==TK_ISNULL );
4062 assert( TK_NOTNULL==OP_NotNull ); testcase( op==TK_NOTNULL );
4063 sqlite3VdbeAddOp2(v, OP_Integer, 1, target);
4064 r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free1);
4065 testcase( regFree1==0 );
4066 addr = sqlite3VdbeAddOp1(v, op, r1);
4067 VdbeCoverageIf(v, op==TK_ISNULL);
4068 VdbeCoverageIf(v, op==TK_NOTNULL);
4069 sqlite3VdbeAddOp2(v, OP_Integer, 0, target);
4070 sqlite3VdbeJumpHere(v, addr);
4071 break;
4072 }
4073 case TK_AGG_FUNCTION: {
4074 AggInfo *pInfo = pExpr->pAggInfo;
4075 if( pInfo==0 ){
4076 assert( !ExprHasProperty(pExpr, EP_IntValue) );
4077 sqlite3ErrorMsg(pParse, "misuse of aggregate: %s()", pExpr->u.zToken);
4078 }else{
4079 return pInfo->aFunc[pExpr->iAgg].iMem;
4080 }
4081 break;
4082 }
4083 case TK_FUNCTION: {
4084 ExprList *pFarg; /* List of function arguments */
4085 int nFarg; /* Number of function arguments */
4086 FuncDef *pDef; /* The function definition object */
4087 const char *zId; /* The function name */
4088 u32 constMask = 0; /* Mask of function arguments that are constant */
4089 int i; /* Loop counter */
4090 sqlite3 *db = pParse->db; /* The database connection */
4091 u8 enc = ENC(db); /* The text encoding used by this database */
4092 CollSeq *pColl = 0; /* A collating sequence */
4093
4094 #ifndef SQLITE_OMIT_WINDOWFUNC
4095 if( ExprHasProperty(pExpr, EP_WinFunc) ){
4096 return pExpr->y.pWin->regResult;
4097 }
4098 #endif
4099
4100 if( ConstFactorOk(pParse) && sqlite3ExprIsConstantNotJoin(pExpr) ){
4101 /* SQL functions can be expensive. So try to move constant functions
4102 ** out of the inner loop, even if that means an extra OP_Copy. */
4103 return sqlite3ExprCodeAtInit(pParse, pExpr, -1);
4104 }
4105 assert( !ExprHasProperty(pExpr, EP_xIsSelect) );
4106 if( ExprHasProperty(pExpr, EP_TokenOnly) ){
4107 pFarg = 0;
4108 }else{
4109 pFarg = pExpr->x.pList;
4110 }
4111 nFarg = pFarg ? pFarg->nExpr : 0;
4112 assert( !ExprHasProperty(pExpr, EP_IntValue) );
4113 zId = pExpr->u.zToken;
4114 pDef = sqlite3FindFunction(db, zId, nFarg, enc, 0);
4115 #ifdef SQLITE_ENABLE_UNKNOWN_SQL_FUNCTION
4116 if( pDef==0 && pParse->explain ){
4117 pDef = sqlite3FindFunction(db, "unknown", nFarg, enc, 0);
4118 }
4119 #endif
4120 if( pDef==0 || pDef->xFinalize!=0 ){
4121 sqlite3ErrorMsg(pParse, "unknown function: %s()", zId);
4122 break;
4123 }
4124 if( pDef->funcFlags & SQLITE_FUNC_INLINE ){
4125 assert( (pDef->funcFlags & SQLITE_FUNC_UNSAFE)==0 );
4126 assert( (pDef->funcFlags & SQLITE_FUNC_DIRECT)==0 );
4127 return exprCodeInlineFunction(pParse, pFarg,
4128 SQLITE_PTR_TO_INT(pDef->pUserData), target);
4129 }else if( pDef->funcFlags & (SQLITE_FUNC_DIRECT|SQLITE_FUNC_UNSAFE) ){
4130 sqlite3ExprFunctionUsable(pParse, pExpr, pDef);
4131 }
4132
4133 for(i=0; i<nFarg; i++){
4134 if( i<32 && sqlite3ExprIsConstant(pFarg->a[i].pExpr) ){
4135 testcase( i==31 );
4136 constMask |= MASKBIT32(i);
4137 }
4138 if( (pDef->funcFlags & SQLITE_FUNC_NEEDCOLL)!=0 && !pColl ){
4139 pColl = sqlite3ExprCollSeq(pParse, pFarg->a[i].pExpr);
4140 }
4141 }
4142 if( pFarg ){
4143 if( constMask ){
4144 r1 = pParse->nMem+1;
4145 pParse->nMem += nFarg;
4146 }else{
4147 r1 = sqlite3GetTempRange(pParse, nFarg);
4148 }
4149
4150 /* For length() and typeof() functions with a column argument,
4151 ** set the P5 parameter to the OP_Column opcode to OPFLAG_LENGTHARG
4152 ** or OPFLAG_TYPEOFARG respectively, to avoid unnecessary data
4153 ** loading.
4154 */
4155 if( (pDef->funcFlags & (SQLITE_FUNC_LENGTH|SQLITE_FUNC_TYPEOF))!=0 ){
4156 u8 exprOp;
4157 assert( nFarg==1 );
4158 assert( pFarg->a[0].pExpr!=0 );
4159 exprOp = pFarg->a[0].pExpr->op;
4160 if( exprOp==TK_COLUMN || exprOp==TK_AGG_COLUMN ){
4161 assert( SQLITE_FUNC_LENGTH==OPFLAG_LENGTHARG );
4162 assert( SQLITE_FUNC_TYPEOF==OPFLAG_TYPEOFARG );
4163 testcase( pDef->funcFlags & OPFLAG_LENGTHARG );
4164 pFarg->a[0].pExpr->op2 =
4165 pDef->funcFlags & (OPFLAG_LENGTHARG|OPFLAG_TYPEOFARG);
4166 }
4167 }
4168
4169 sqlite3ExprCodeExprList(pParse, pFarg, r1, 0,
4170 SQLITE_ECEL_DUP|SQLITE_ECEL_FACTOR);
4171 }else{
4172 r1 = 0;
4173 }
4174 #ifndef SQLITE_OMIT_VIRTUALTABLE
4175 /* Possibly overload the function if the first argument is
4176 ** a virtual table column.
4177 **
4178 ** For infix functions (LIKE, GLOB, REGEXP, and MATCH) use the
4179 ** second argument, not the first, as the argument to test to
4180 ** see if it is a column in a virtual table. This is done because
4181 ** the left operand of infix functions (the operand we want to
4182 ** control overloading) ends up as the second argument to the
4183 ** function. The expression "A glob B" is equivalent to
4184 ** "glob(B,A). We want to use the A in "A glob B" to test
4185 ** for function overloading. But we use the B term in "glob(B,A)".
4186 */
4187 if( nFarg>=2 && ExprHasProperty(pExpr, EP_InfixFunc) ){
4188 pDef = sqlite3VtabOverloadFunction(db, pDef, nFarg, pFarg->a[1].pExpr);
4189 }else if( nFarg>0 ){
4190 pDef = sqlite3VtabOverloadFunction(db, pDef, nFarg, pFarg->a[0].pExpr);
4191 }
4192 #endif
4193 if( pDef->funcFlags & SQLITE_FUNC_NEEDCOLL ){
4194 if( !pColl ) pColl = db->pDfltColl;
4195 sqlite3VdbeAddOp4(v, OP_CollSeq, 0, 0, 0, (char *)pColl, P4_COLLSEQ);
4196 }
4197 #ifdef SQLITE_ENABLE_OFFSET_SQL_FUNC
4198 if( pDef->funcFlags & SQLITE_FUNC_OFFSET ){
4199 Expr *pArg = pFarg->a[0].pExpr;
4200 if( pArg->op==TK_COLUMN ){
4201 sqlite3VdbeAddOp3(v, OP_Offset, pArg->iTable, pArg->iColumn, target);
4202 }else{
4203 sqlite3VdbeAddOp2(v, OP_Null, 0, target);
4204 }
4205 }else
4206 #endif
4207 {
4208 sqlite3VdbeAddFunctionCall(pParse, constMask, r1, target, nFarg,
4209 pDef, pExpr->op2);
4210 }
4211 if( nFarg ){
4212 if( constMask==0 ){
4213 sqlite3ReleaseTempRange(pParse, r1, nFarg);
4214 }else{
4215 sqlite3VdbeReleaseRegisters(pParse, r1, nFarg, constMask, 1);
4216 }
4217 }
4218 return target;
4219 }
4220 #ifndef SQLITE_OMIT_SUBQUERY
4221 case TK_EXISTS:
4222 case TK_SELECT: {
4223 int nCol;
4224 testcase( op==TK_EXISTS );
4225 testcase( op==TK_SELECT );
4226 if( op==TK_SELECT && (nCol = pExpr->x.pSelect->pEList->nExpr)!=1 ){
4227 sqlite3SubselectError(pParse, nCol, 1);
4228 }else{
4229 return sqlite3CodeSubselect(pParse, pExpr);
4230 }
4231 break;
4232 }
4233 case TK_SELECT_COLUMN: {
4234 int n;
4235 if( pExpr->pLeft->iTable==0 ){
4236 pExpr->pLeft->iTable = sqlite3CodeSubselect(pParse, pExpr->pLeft);
4237 }
4238 assert( pExpr->iTable==0 || pExpr->pLeft->op==TK_SELECT );
4239 if( pExpr->iTable!=0
4240 && pExpr->iTable!=(n = sqlite3ExprVectorSize(pExpr->pLeft))
4241 ){
4242 sqlite3ErrorMsg(pParse, "%d columns assigned %d values",
4243 pExpr->iTable, n);
4244 }
4245 return pExpr->pLeft->iTable + pExpr->iColumn;
4246 }
4247 case TK_IN: {
4248 int destIfFalse = sqlite3VdbeMakeLabel(pParse);
4249 int destIfNull = sqlite3VdbeMakeLabel(pParse);
4250 sqlite3VdbeAddOp2(v, OP_Null, 0, target);
4251 sqlite3ExprCodeIN(pParse, pExpr, destIfFalse, destIfNull);
4252 sqlite3VdbeAddOp2(v, OP_Integer, 1, target);
4253 sqlite3VdbeResolveLabel(v, destIfFalse);
4254 sqlite3VdbeAddOp2(v, OP_AddImm, target, 0);
4255 sqlite3VdbeResolveLabel(v, destIfNull);
4256 return target;
4257 }
4258 #endif /* SQLITE_OMIT_SUBQUERY */
4259
4260
4261 /*
4262 ** x BETWEEN y AND z
4263 **
4264 ** This is equivalent to
4265 **
4266 ** x>=y AND x<=z
4267 **
4268 ** X is stored in pExpr->pLeft.
4269 ** Y is stored in pExpr->pList->a[0].pExpr.
4270 ** Z is stored in pExpr->pList->a[1].pExpr.
4271 */
4272 case TK_BETWEEN: {
4273 exprCodeBetween(pParse, pExpr, target, 0, 0);
4274 return target;
4275 }
4276 case TK_SPAN:
4277 case TK_COLLATE:
4278 case TK_UPLUS: {
4279 pExpr = pExpr->pLeft;
4280 goto expr_code_doover; /* 2018-04-28: Prevent deep recursion. OSSFuzz. */
4281 }
4282
4283 case TK_TRIGGER: {
4284 /* If the opcode is TK_TRIGGER, then the expression is a reference
4285 ** to a column in the new.* or old.* pseudo-tables available to
4286 ** trigger programs. In this case Expr.iTable is set to 1 for the
4287 ** new.* pseudo-table, or 0 for the old.* pseudo-table. Expr.iColumn
4288 ** is set to the column of the pseudo-table to read, or to -1 to
4289 ** read the rowid field.
4290 **
4291 ** The expression is implemented using an OP_Param opcode. The p1
4292 ** parameter is set to 0 for an old.rowid reference, or to (i+1)
4293 ** to reference another column of the old.* pseudo-table, where
4294 ** i is the index of the column. For a new.rowid reference, p1 is
4295 ** set to (n+1), where n is the number of columns in each pseudo-table.
4296 ** For a reference to any other column in the new.* pseudo-table, p1
4297 ** is set to (n+2+i), where n and i are as defined previously. For
4298 ** example, if the table on which triggers are being fired is
4299 ** declared as:
4300 **
4301 ** CREATE TABLE t1(a, b);
4302 **
4303 ** Then p1 is interpreted as follows:
4304 **
4305 ** p1==0 -> old.rowid p1==3 -> new.rowid
4306 ** p1==1 -> old.a p1==4 -> new.a
4307 ** p1==2 -> old.b p1==5 -> new.b
4308 */
4309 Table *pTab = pExpr->y.pTab;
4310 int iCol = pExpr->iColumn;
4311 int p1 = pExpr->iTable * (pTab->nCol+1) + 1
4312 + sqlite3TableColumnToStorage(pTab, iCol);
4313
4314 assert( pExpr->iTable==0 || pExpr->iTable==1 );
4315 assert( iCol>=-1 && iCol<pTab->nCol );
4316 assert( pTab->iPKey<0 || iCol!=pTab->iPKey );
4317 assert( p1>=0 && p1<(pTab->nCol*2+2) );
4318
4319 sqlite3VdbeAddOp2(v, OP_Param, p1, target);
4320 VdbeComment((v, "r[%d]=%s.%s", target,
4321 (pExpr->iTable ? "new" : "old"),
4322 (pExpr->iColumn<0 ? "rowid" : pExpr->y.pTab->aCol[iCol].zName)
4323 ));
4324
4325 #ifndef SQLITE_OMIT_FLOATING_POINT
4326 /* If the column has REAL affinity, it may currently be stored as an
4327 ** integer. Use OP_RealAffinity to make sure it is really real.
4328 **
4329 ** EVIDENCE-OF: R-60985-57662 SQLite will convert the value back to
4330 ** floating point when extracting it from the record. */
4331 if( iCol>=0 && pTab->aCol[iCol].affinity==SQLITE_AFF_REAL ){
4332 sqlite3VdbeAddOp1(v, OP_RealAffinity, target);
4333 }
4334 #endif
4335 break;
4336 }
4337
4338 case TK_VECTOR: {
4339 sqlite3ErrorMsg(pParse, "row value misused");
4340 break;
4341 }
4342
4343 /* TK_IF_NULL_ROW Expr nodes are inserted ahead of expressions
4344 ** that derive from the right-hand table of a LEFT JOIN. The
4345 ** Expr.iTable value is the table number for the right-hand table.
4346 ** The expression is only evaluated if that table is not currently
4347 ** on a LEFT JOIN NULL row.
4348 */
4349 case TK_IF_NULL_ROW: {
4350 int addrINR;
4351 u8 okConstFactor = pParse->okConstFactor;
4352 addrINR = sqlite3VdbeAddOp1(v, OP_IfNullRow, pExpr->iTable);
4353 /* Temporarily disable factoring of constant expressions, since
4354 ** even though expressions may appear to be constant, they are not
4355 ** really constant because they originate from the right-hand side
4356 ** of a LEFT JOIN. */
4357 pParse->okConstFactor = 0;
4358 inReg = sqlite3ExprCodeTarget(pParse, pExpr->pLeft, target);
4359 pParse->okConstFactor = okConstFactor;
4360 sqlite3VdbeJumpHere(v, addrINR);
4361 sqlite3VdbeChangeP3(v, addrINR, inReg);
4362 break;
4363 }
4364
4365 /*
4366 ** Form A:
4367 ** CASE x WHEN e1 THEN r1 WHEN e2 THEN r2 ... WHEN eN THEN rN ELSE y END
4368 **
4369 ** Form B:
4370 ** CASE WHEN e1 THEN r1 WHEN e2 THEN r2 ... WHEN eN THEN rN ELSE y END
4371 **
4372 ** Form A is can be transformed into the equivalent form B as follows:
4373 ** CASE WHEN x=e1 THEN r1 WHEN x=e2 THEN r2 ...
4374 ** WHEN x=eN THEN rN ELSE y END
4375 **
4376 ** X (if it exists) is in pExpr->pLeft.
4377 ** Y is in the last element of pExpr->x.pList if pExpr->x.pList->nExpr is
4378 ** odd. The Y is also optional. If the number of elements in x.pList
4379 ** is even, then Y is omitted and the "otherwise" result is NULL.
4380 ** Ei is in pExpr->pList->a[i*2] and Ri is pExpr->pList->a[i*2+1].
4381 **
4382 ** The result of the expression is the Ri for the first matching Ei,
4383 ** or if there is no matching Ei, the ELSE term Y, or if there is
4384 ** no ELSE term, NULL.
4385 */
4386 case TK_CASE: {
4387 int endLabel; /* GOTO label for end of CASE stmt */
4388 int nextCase; /* GOTO label for next WHEN clause */
4389 int nExpr; /* 2x number of WHEN terms */
4390 int i; /* Loop counter */
4391 ExprList *pEList; /* List of WHEN terms */
4392 struct ExprList_item *aListelem; /* Array of WHEN terms */
4393 Expr opCompare; /* The X==Ei expression */
4394 Expr *pX; /* The X expression */
4395 Expr *pTest = 0; /* X==Ei (form A) or just Ei (form B) */
4396 Expr *pDel = 0;
4397 sqlite3 *db = pParse->db;
4398
4399 assert( !ExprHasProperty(pExpr, EP_xIsSelect) && pExpr->x.pList );
4400 assert(pExpr->x.pList->nExpr > 0);
4401 pEList = pExpr->x.pList;
4402 aListelem = pEList->a;
4403 nExpr = pEList->nExpr;
4404 endLabel = sqlite3VdbeMakeLabel(pParse);
4405 if( (pX = pExpr->pLeft)!=0 ){
4406 pDel = sqlite3ExprDup(db, pX, 0);
4407 if( db->mallocFailed ){
4408 sqlite3ExprDelete(db, pDel);
4409 break;
4410 }
4411 testcase( pX->op==TK_COLUMN );
4412 exprToRegister(pDel, exprCodeVector(pParse, pDel, ®Free1));
4413 testcase( regFree1==0 );
4414 memset(&opCompare, 0, sizeof(opCompare));
4415 opCompare.op = TK_EQ;
4416 opCompare.pLeft = pDel;
4417 pTest = &opCompare;
4418 /* Ticket b351d95f9cd5ef17e9d9dbae18f5ca8611190001:
4419 ** The value in regFree1 might get SCopy-ed into the file result.
4420 ** So make sure that the regFree1 register is not reused for other
4421 ** purposes and possibly overwritten. */
4422 regFree1 = 0;
4423 }
4424 for(i=0; i<nExpr-1; i=i+2){
4425 if( pX ){
4426 assert( pTest!=0 );
4427 opCompare.pRight = aListelem[i].pExpr;
4428 }else{
4429 pTest = aListelem[i].pExpr;
4430 }
4431 nextCase = sqlite3VdbeMakeLabel(pParse);
4432 testcase( pTest->op==TK_COLUMN );
4433 sqlite3ExprIfFalse(pParse, pTest, nextCase, SQLITE_JUMPIFNULL);
4434 testcase( aListelem[i+1].pExpr->op==TK_COLUMN );
4435 sqlite3ExprCode(pParse, aListelem[i+1].pExpr, target);
4436 sqlite3VdbeGoto(v, endLabel);
4437 sqlite3VdbeResolveLabel(v, nextCase);
4438 }
4439 if( (nExpr&1)!=0 ){
4440 sqlite3ExprCode(pParse, pEList->a[nExpr-1].pExpr, target);
4441 }else{
4442 sqlite3VdbeAddOp2(v, OP_Null, 0, target);
4443 }
4444 sqlite3ExprDelete(db, pDel);
4445 sqlite3VdbeResolveLabel(v, endLabel);
4446 break;
4447 }
4448 #ifndef SQLITE_OMIT_TRIGGER
4449 case TK_RAISE: {
4450 assert( pExpr->affExpr==OE_Rollback
4451 || pExpr->affExpr==OE_Abort
4452 || pExpr->affExpr==OE_Fail
4453 || pExpr->affExpr==OE_Ignore
4454 );
4455 if( !pParse->pTriggerTab ){
4456 sqlite3ErrorMsg(pParse,
4457 "RAISE() may only be used within a trigger-program");
4458 return 0;
4459 }
4460 if( pExpr->affExpr==OE_Abort ){
4461 sqlite3MayAbort(pParse);
4462 }
4463 assert( !ExprHasProperty(pExpr, EP_IntValue) );
4464 if( pExpr->affExpr==OE_Ignore ){
4465 sqlite3VdbeAddOp4(
4466 v, OP_Halt, SQLITE_OK, OE_Ignore, 0, pExpr->u.zToken,0);
4467 VdbeCoverage(v);
4468 }else{
4469 sqlite3HaltConstraint(pParse, SQLITE_CONSTRAINT_TRIGGER,
4470 pExpr->affExpr, pExpr->u.zToken, 0, 0);
4471 }
4472
4473 break;
4474 }
4475 #endif
4476 }
4477 sqlite3ReleaseTempReg(pParse, regFree1);
4478 sqlite3ReleaseTempReg(pParse, regFree2);
4479 return inReg;
4480 }
4481
4482 /*
4483 ** Factor out the code of the given expression to initialization time.
4484 **
4485 ** If regDest>=0 then the result is always stored in that register and the
4486 ** result is not reusable. If regDest<0 then this routine is free to
4487 ** store the value whereever it wants. The register where the expression
4488 ** is stored is returned. When regDest<0, two identical expressions will
4489 ** code to the same register.
4490 */
sqlite3ExprCodeAtInit(Parse * pParse,Expr * pExpr,int regDest)4491 int sqlite3ExprCodeAtInit(
4492 Parse *pParse, /* Parsing context */
4493 Expr *pExpr, /* The expression to code when the VDBE initializes */
4494 int regDest /* Store the value in this register */
4495 ){
4496 ExprList *p;
4497 assert( ConstFactorOk(pParse) );
4498 p = pParse->pConstExpr;
4499 if( regDest<0 && p ){
4500 struct ExprList_item *pItem;
4501 int i;
4502 for(pItem=p->a, i=p->nExpr; i>0; pItem++, i--){
4503 if( pItem->reusable && sqlite3ExprCompare(0,pItem->pExpr,pExpr,-1)==0 ){
4504 return pItem->u.iConstExprReg;
4505 }
4506 }
4507 }
4508 pExpr = sqlite3ExprDup(pParse->db, pExpr, 0);
4509 p = sqlite3ExprListAppend(pParse, p, pExpr);
4510 if( p ){
4511 struct ExprList_item *pItem = &p->a[p->nExpr-1];
4512 pItem->reusable = regDest<0;
4513 if( regDest<0 ) regDest = ++pParse->nMem;
4514 pItem->u.iConstExprReg = regDest;
4515 }
4516 pParse->pConstExpr = p;
4517 return regDest;
4518 }
4519
4520 /*
4521 ** Generate code to evaluate an expression and store the results
4522 ** into a register. Return the register number where the results
4523 ** are stored.
4524 **
4525 ** If the register is a temporary register that can be deallocated,
4526 ** then write its number into *pReg. If the result register is not
4527 ** a temporary, then set *pReg to zero.
4528 **
4529 ** If pExpr is a constant, then this routine might generate this
4530 ** code to fill the register in the initialization section of the
4531 ** VDBE program, in order to factor it out of the evaluation loop.
4532 */
sqlite3ExprCodeTemp(Parse * pParse,Expr * pExpr,int * pReg)4533 int sqlite3ExprCodeTemp(Parse *pParse, Expr *pExpr, int *pReg){
4534 int r2;
4535 pExpr = sqlite3ExprSkipCollateAndLikely(pExpr);
4536 if( ConstFactorOk(pParse)
4537 && pExpr->op!=TK_REGISTER
4538 && sqlite3ExprIsConstantNotJoin(pExpr)
4539 ){
4540 *pReg = 0;
4541 r2 = sqlite3ExprCodeAtInit(pParse, pExpr, -1);
4542 }else{
4543 int r1 = sqlite3GetTempReg(pParse);
4544 r2 = sqlite3ExprCodeTarget(pParse, pExpr, r1);
4545 if( r2==r1 ){
4546 *pReg = r1;
4547 }else{
4548 sqlite3ReleaseTempReg(pParse, r1);
4549 *pReg = 0;
4550 }
4551 }
4552 return r2;
4553 }
4554
4555 /*
4556 ** Generate code that will evaluate expression pExpr and store the
4557 ** results in register target. The results are guaranteed to appear
4558 ** in register target.
4559 */
sqlite3ExprCode(Parse * pParse,Expr * pExpr,int target)4560 void sqlite3ExprCode(Parse *pParse, Expr *pExpr, int target){
4561 int inReg;
4562
4563 assert( target>0 && target<=pParse->nMem );
4564 inReg = sqlite3ExprCodeTarget(pParse, pExpr, target);
4565 assert( pParse->pVdbe!=0 || pParse->db->mallocFailed );
4566 if( inReg!=target && pParse->pVdbe ){
4567 u8 op;
4568 if( ExprHasProperty(pExpr,EP_Subquery) ){
4569 op = OP_Copy;
4570 }else{
4571 op = OP_SCopy;
4572 }
4573 sqlite3VdbeAddOp2(pParse->pVdbe, op, inReg, target);
4574 }
4575 }
4576
4577 /*
4578 ** Make a transient copy of expression pExpr and then code it using
4579 ** sqlite3ExprCode(). This routine works just like sqlite3ExprCode()
4580 ** except that the input expression is guaranteed to be unchanged.
4581 */
sqlite3ExprCodeCopy(Parse * pParse,Expr * pExpr,int target)4582 void sqlite3ExprCodeCopy(Parse *pParse, Expr *pExpr, int target){
4583 sqlite3 *db = pParse->db;
4584 pExpr = sqlite3ExprDup(db, pExpr, 0);
4585 if( !db->mallocFailed ) sqlite3ExprCode(pParse, pExpr, target);
4586 sqlite3ExprDelete(db, pExpr);
4587 }
4588
4589 /*
4590 ** Generate code that will evaluate expression pExpr and store the
4591 ** results in register target. The results are guaranteed to appear
4592 ** in register target. If the expression is constant, then this routine
4593 ** might choose to code the expression at initialization time.
4594 */
sqlite3ExprCodeFactorable(Parse * pParse,Expr * pExpr,int target)4595 void sqlite3ExprCodeFactorable(Parse *pParse, Expr *pExpr, int target){
4596 if( pParse->okConstFactor && sqlite3ExprIsConstantNotJoin(pExpr) ){
4597 sqlite3ExprCodeAtInit(pParse, pExpr, target);
4598 }else{
4599 sqlite3ExprCodeCopy(pParse, pExpr, target);
4600 }
4601 }
4602
4603 /*
4604 ** Generate code that pushes the value of every element of the given
4605 ** expression list into a sequence of registers beginning at target.
4606 **
4607 ** Return the number of elements evaluated. The number returned will
4608 ** usually be pList->nExpr but might be reduced if SQLITE_ECEL_OMITREF
4609 ** is defined.
4610 **
4611 ** The SQLITE_ECEL_DUP flag prevents the arguments from being
4612 ** filled using OP_SCopy. OP_Copy must be used instead.
4613 **
4614 ** The SQLITE_ECEL_FACTOR argument allows constant arguments to be
4615 ** factored out into initialization code.
4616 **
4617 ** The SQLITE_ECEL_REF flag means that expressions in the list with
4618 ** ExprList.a[].u.x.iOrderByCol>0 have already been evaluated and stored
4619 ** in registers at srcReg, and so the value can be copied from there.
4620 ** If SQLITE_ECEL_OMITREF is also set, then the values with u.x.iOrderByCol>0
4621 ** are simply omitted rather than being copied from srcReg.
4622 */
sqlite3ExprCodeExprList(Parse * pParse,ExprList * pList,int target,int srcReg,u8 flags)4623 int sqlite3ExprCodeExprList(
4624 Parse *pParse, /* Parsing context */
4625 ExprList *pList, /* The expression list to be coded */
4626 int target, /* Where to write results */
4627 int srcReg, /* Source registers if SQLITE_ECEL_REF */
4628 u8 flags /* SQLITE_ECEL_* flags */
4629 ){
4630 struct ExprList_item *pItem;
4631 int i, j, n;
4632 u8 copyOp = (flags & SQLITE_ECEL_DUP) ? OP_Copy : OP_SCopy;
4633 Vdbe *v = pParse->pVdbe;
4634 assert( pList!=0 );
4635 assert( target>0 );
4636 assert( pParse->pVdbe!=0 ); /* Never gets this far otherwise */
4637 n = pList->nExpr;
4638 if( !ConstFactorOk(pParse) ) flags &= ~SQLITE_ECEL_FACTOR;
4639 for(pItem=pList->a, i=0; i<n; i++, pItem++){
4640 Expr *pExpr = pItem->pExpr;
4641 #ifdef SQLITE_ENABLE_SORTER_REFERENCES
4642 if( pItem->bSorterRef ){
4643 i--;
4644 n--;
4645 }else
4646 #endif
4647 if( (flags & SQLITE_ECEL_REF)!=0 && (j = pItem->u.x.iOrderByCol)>0 ){
4648 if( flags & SQLITE_ECEL_OMITREF ){
4649 i--;
4650 n--;
4651 }else{
4652 sqlite3VdbeAddOp2(v, copyOp, j+srcReg-1, target+i);
4653 }
4654 }else if( (flags & SQLITE_ECEL_FACTOR)!=0
4655 && sqlite3ExprIsConstantNotJoin(pExpr)
4656 ){
4657 sqlite3ExprCodeAtInit(pParse, pExpr, target+i);
4658 }else{
4659 int inReg = sqlite3ExprCodeTarget(pParse, pExpr, target+i);
4660 if( inReg!=target+i ){
4661 VdbeOp *pOp;
4662 if( copyOp==OP_Copy
4663 && (pOp=sqlite3VdbeGetOp(v, -1))->opcode==OP_Copy
4664 && pOp->p1+pOp->p3+1==inReg
4665 && pOp->p2+pOp->p3+1==target+i
4666 && pOp->p5==0 /* The do-not-merge flag must be clear */
4667 ){
4668 pOp->p3++;
4669 }else{
4670 sqlite3VdbeAddOp2(v, copyOp, inReg, target+i);
4671 }
4672 }
4673 }
4674 }
4675 return n;
4676 }
4677
4678 /*
4679 ** Generate code for a BETWEEN operator.
4680 **
4681 ** x BETWEEN y AND z
4682 **
4683 ** The above is equivalent to
4684 **
4685 ** x>=y AND x<=z
4686 **
4687 ** Code it as such, taking care to do the common subexpression
4688 ** elimination of x.
4689 **
4690 ** The xJumpIf parameter determines details:
4691 **
4692 ** NULL: Store the boolean result in reg[dest]
4693 ** sqlite3ExprIfTrue: Jump to dest if true
4694 ** sqlite3ExprIfFalse: Jump to dest if false
4695 **
4696 ** The jumpIfNull parameter is ignored if xJumpIf is NULL.
4697 */
exprCodeBetween(Parse * pParse,Expr * pExpr,int dest,void (* xJump)(Parse *,Expr *,int,int),int jumpIfNull)4698 static void exprCodeBetween(
4699 Parse *pParse, /* Parsing and code generating context */
4700 Expr *pExpr, /* The BETWEEN expression */
4701 int dest, /* Jump destination or storage location */
4702 void (*xJump)(Parse*,Expr*,int,int), /* Action to take */
4703 int jumpIfNull /* Take the jump if the BETWEEN is NULL */
4704 ){
4705 Expr exprAnd; /* The AND operator in x>=y AND x<=z */
4706 Expr compLeft; /* The x>=y term */
4707 Expr compRight; /* The x<=z term */
4708 int regFree1 = 0; /* Temporary use register */
4709 Expr *pDel = 0;
4710 sqlite3 *db = pParse->db;
4711
4712 memset(&compLeft, 0, sizeof(Expr));
4713 memset(&compRight, 0, sizeof(Expr));
4714 memset(&exprAnd, 0, sizeof(Expr));
4715
4716 assert( !ExprHasProperty(pExpr, EP_xIsSelect) );
4717 pDel = sqlite3ExprDup(db, pExpr->pLeft, 0);
4718 if( db->mallocFailed==0 ){
4719 exprAnd.op = TK_AND;
4720 exprAnd.pLeft = &compLeft;
4721 exprAnd.pRight = &compRight;
4722 compLeft.op = TK_GE;
4723 compLeft.pLeft = pDel;
4724 compLeft.pRight = pExpr->x.pList->a[0].pExpr;
4725 compRight.op = TK_LE;
4726 compRight.pLeft = pDel;
4727 compRight.pRight = pExpr->x.pList->a[1].pExpr;
4728 exprToRegister(pDel, exprCodeVector(pParse, pDel, ®Free1));
4729 if( xJump ){
4730 xJump(pParse, &exprAnd, dest, jumpIfNull);
4731 }else{
4732 /* Mark the expression is being from the ON or USING clause of a join
4733 ** so that the sqlite3ExprCodeTarget() routine will not attempt to move
4734 ** it into the Parse.pConstExpr list. We should use a new bit for this,
4735 ** for clarity, but we are out of bits in the Expr.flags field so we
4736 ** have to reuse the EP_FromJoin bit. Bummer. */
4737 pDel->flags |= EP_FromJoin;
4738 sqlite3ExprCodeTarget(pParse, &exprAnd, dest);
4739 }
4740 sqlite3ReleaseTempReg(pParse, regFree1);
4741 }
4742 sqlite3ExprDelete(db, pDel);
4743
4744 /* Ensure adequate test coverage */
4745 testcase( xJump==sqlite3ExprIfTrue && jumpIfNull==0 && regFree1==0 );
4746 testcase( xJump==sqlite3ExprIfTrue && jumpIfNull==0 && regFree1!=0 );
4747 testcase( xJump==sqlite3ExprIfTrue && jumpIfNull!=0 && regFree1==0 );
4748 testcase( xJump==sqlite3ExprIfTrue && jumpIfNull!=0 && regFree1!=0 );
4749 testcase( xJump==sqlite3ExprIfFalse && jumpIfNull==0 && regFree1==0 );
4750 testcase( xJump==sqlite3ExprIfFalse && jumpIfNull==0 && regFree1!=0 );
4751 testcase( xJump==sqlite3ExprIfFalse && jumpIfNull!=0 && regFree1==0 );
4752 testcase( xJump==sqlite3ExprIfFalse && jumpIfNull!=0 && regFree1!=0 );
4753 testcase( xJump==0 );
4754 }
4755
4756 /*
4757 ** Generate code for a boolean expression such that a jump is made
4758 ** to the label "dest" if the expression is true but execution
4759 ** continues straight thru if the expression is false.
4760 **
4761 ** If the expression evaluates to NULL (neither true nor false), then
4762 ** take the jump if the jumpIfNull flag is SQLITE_JUMPIFNULL.
4763 **
4764 ** This code depends on the fact that certain token values (ex: TK_EQ)
4765 ** are the same as opcode values (ex: OP_Eq) that implement the corresponding
4766 ** operation. Special comments in vdbe.c and the mkopcodeh.awk script in
4767 ** the make process cause these values to align. Assert()s in the code
4768 ** below verify that the numbers are aligned correctly.
4769 */
sqlite3ExprIfTrue(Parse * pParse,Expr * pExpr,int dest,int jumpIfNull)4770 void sqlite3ExprIfTrue(Parse *pParse, Expr *pExpr, int dest, int jumpIfNull){
4771 Vdbe *v = pParse->pVdbe;
4772 int op = 0;
4773 int regFree1 = 0;
4774 int regFree2 = 0;
4775 int r1, r2;
4776
4777 assert( jumpIfNull==SQLITE_JUMPIFNULL || jumpIfNull==0 );
4778 if( NEVER(v==0) ) return; /* Existence of VDBE checked by caller */
4779 if( NEVER(pExpr==0) ) return; /* No way this can happen */
4780 op = pExpr->op;
4781 switch( op ){
4782 case TK_AND:
4783 case TK_OR: {
4784 Expr *pAlt = sqlite3ExprSimplifiedAndOr(pExpr);
4785 if( pAlt!=pExpr ){
4786 sqlite3ExprIfTrue(pParse, pAlt, dest, jumpIfNull);
4787 }else if( op==TK_AND ){
4788 int d2 = sqlite3VdbeMakeLabel(pParse);
4789 testcase( jumpIfNull==0 );
4790 sqlite3ExprIfFalse(pParse, pExpr->pLeft, d2,
4791 jumpIfNull^SQLITE_JUMPIFNULL);
4792 sqlite3ExprIfTrue(pParse, pExpr->pRight, dest, jumpIfNull);
4793 sqlite3VdbeResolveLabel(v, d2);
4794 }else{
4795 testcase( jumpIfNull==0 );
4796 sqlite3ExprIfTrue(pParse, pExpr->pLeft, dest, jumpIfNull);
4797 sqlite3ExprIfTrue(pParse, pExpr->pRight, dest, jumpIfNull);
4798 }
4799 break;
4800 }
4801 case TK_NOT: {
4802 testcase( jumpIfNull==0 );
4803 sqlite3ExprIfFalse(pParse, pExpr->pLeft, dest, jumpIfNull);
4804 break;
4805 }
4806 case TK_TRUTH: {
4807 int isNot; /* IS NOT TRUE or IS NOT FALSE */
4808 int isTrue; /* IS TRUE or IS NOT TRUE */
4809 testcase( jumpIfNull==0 );
4810 isNot = pExpr->op2==TK_ISNOT;
4811 isTrue = sqlite3ExprTruthValue(pExpr->pRight);
4812 testcase( isTrue && isNot );
4813 testcase( !isTrue && isNot );
4814 if( isTrue ^ isNot ){
4815 sqlite3ExprIfTrue(pParse, pExpr->pLeft, dest,
4816 isNot ? SQLITE_JUMPIFNULL : 0);
4817 }else{
4818 sqlite3ExprIfFalse(pParse, pExpr->pLeft, dest,
4819 isNot ? SQLITE_JUMPIFNULL : 0);
4820 }
4821 break;
4822 }
4823 case TK_IS:
4824 case TK_ISNOT:
4825 testcase( op==TK_IS );
4826 testcase( op==TK_ISNOT );
4827 op = (op==TK_IS) ? TK_EQ : TK_NE;
4828 jumpIfNull = SQLITE_NULLEQ;
4829 /* Fall thru */
4830 case TK_LT:
4831 case TK_LE:
4832 case TK_GT:
4833 case TK_GE:
4834 case TK_NE:
4835 case TK_EQ: {
4836 if( sqlite3ExprIsVector(pExpr->pLeft) ) goto default_expr;
4837 testcase( jumpIfNull==0 );
4838 r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free1);
4839 r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, ®Free2);
4840 codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op,
4841 r1, r2, dest, jumpIfNull, ExprHasProperty(pExpr,EP_Commuted));
4842 assert(TK_LT==OP_Lt); testcase(op==OP_Lt); VdbeCoverageIf(v,op==OP_Lt);
4843 assert(TK_LE==OP_Le); testcase(op==OP_Le); VdbeCoverageIf(v,op==OP_Le);
4844 assert(TK_GT==OP_Gt); testcase(op==OP_Gt); VdbeCoverageIf(v,op==OP_Gt);
4845 assert(TK_GE==OP_Ge); testcase(op==OP_Ge); VdbeCoverageIf(v,op==OP_Ge);
4846 assert(TK_EQ==OP_Eq); testcase(op==OP_Eq);
4847 VdbeCoverageIf(v, op==OP_Eq && jumpIfNull==SQLITE_NULLEQ);
4848 VdbeCoverageIf(v, op==OP_Eq && jumpIfNull!=SQLITE_NULLEQ);
4849 assert(TK_NE==OP_Ne); testcase(op==OP_Ne);
4850 VdbeCoverageIf(v, op==OP_Ne && jumpIfNull==SQLITE_NULLEQ);
4851 VdbeCoverageIf(v, op==OP_Ne && jumpIfNull!=SQLITE_NULLEQ);
4852 testcase( regFree1==0 );
4853 testcase( regFree2==0 );
4854 break;
4855 }
4856 case TK_ISNULL:
4857 case TK_NOTNULL: {
4858 assert( TK_ISNULL==OP_IsNull ); testcase( op==TK_ISNULL );
4859 assert( TK_NOTNULL==OP_NotNull ); testcase( op==TK_NOTNULL );
4860 r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free1);
4861 sqlite3VdbeAddOp2(v, op, r1, dest);
4862 VdbeCoverageIf(v, op==TK_ISNULL);
4863 VdbeCoverageIf(v, op==TK_NOTNULL);
4864 testcase( regFree1==0 );
4865 break;
4866 }
4867 case TK_BETWEEN: {
4868 testcase( jumpIfNull==0 );
4869 exprCodeBetween(pParse, pExpr, dest, sqlite3ExprIfTrue, jumpIfNull);
4870 break;
4871 }
4872 #ifndef SQLITE_OMIT_SUBQUERY
4873 case TK_IN: {
4874 int destIfFalse = sqlite3VdbeMakeLabel(pParse);
4875 int destIfNull = jumpIfNull ? dest : destIfFalse;
4876 sqlite3ExprCodeIN(pParse, pExpr, destIfFalse, destIfNull);
4877 sqlite3VdbeGoto(v, dest);
4878 sqlite3VdbeResolveLabel(v, destIfFalse);
4879 break;
4880 }
4881 #endif
4882 default: {
4883 default_expr:
4884 if( ExprAlwaysTrue(pExpr) ){
4885 sqlite3VdbeGoto(v, dest);
4886 }else if( ExprAlwaysFalse(pExpr) ){
4887 /* No-op */
4888 }else{
4889 r1 = sqlite3ExprCodeTemp(pParse, pExpr, ®Free1);
4890 sqlite3VdbeAddOp3(v, OP_If, r1, dest, jumpIfNull!=0);
4891 VdbeCoverage(v);
4892 testcase( regFree1==0 );
4893 testcase( jumpIfNull==0 );
4894 }
4895 break;
4896 }
4897 }
4898 sqlite3ReleaseTempReg(pParse, regFree1);
4899 sqlite3ReleaseTempReg(pParse, regFree2);
4900 }
4901
4902 /*
4903 ** Generate code for a boolean expression such that a jump is made
4904 ** to the label "dest" if the expression is false but execution
4905 ** continues straight thru if the expression is true.
4906 **
4907 ** If the expression evaluates to NULL (neither true nor false) then
4908 ** jump if jumpIfNull is SQLITE_JUMPIFNULL or fall through if jumpIfNull
4909 ** is 0.
4910 */
sqlite3ExprIfFalse(Parse * pParse,Expr * pExpr,int dest,int jumpIfNull)4911 void sqlite3ExprIfFalse(Parse *pParse, Expr *pExpr, int dest, int jumpIfNull){
4912 Vdbe *v = pParse->pVdbe;
4913 int op = 0;
4914 int regFree1 = 0;
4915 int regFree2 = 0;
4916 int r1, r2;
4917
4918 assert( jumpIfNull==SQLITE_JUMPIFNULL || jumpIfNull==0 );
4919 if( NEVER(v==0) ) return; /* Existence of VDBE checked by caller */
4920 if( pExpr==0 ) return;
4921
4922 /* The value of pExpr->op and op are related as follows:
4923 **
4924 ** pExpr->op op
4925 ** --------- ----------
4926 ** TK_ISNULL OP_NotNull
4927 ** TK_NOTNULL OP_IsNull
4928 ** TK_NE OP_Eq
4929 ** TK_EQ OP_Ne
4930 ** TK_GT OP_Le
4931 ** TK_LE OP_Gt
4932 ** TK_GE OP_Lt
4933 ** TK_LT OP_Ge
4934 **
4935 ** For other values of pExpr->op, op is undefined and unused.
4936 ** The value of TK_ and OP_ constants are arranged such that we
4937 ** can compute the mapping above using the following expression.
4938 ** Assert()s verify that the computation is correct.
4939 */
4940 op = ((pExpr->op+(TK_ISNULL&1))^1)-(TK_ISNULL&1);
4941
4942 /* Verify correct alignment of TK_ and OP_ constants
4943 */
4944 assert( pExpr->op!=TK_ISNULL || op==OP_NotNull );
4945 assert( pExpr->op!=TK_NOTNULL || op==OP_IsNull );
4946 assert( pExpr->op!=TK_NE || op==OP_Eq );
4947 assert( pExpr->op!=TK_EQ || op==OP_Ne );
4948 assert( pExpr->op!=TK_LT || op==OP_Ge );
4949 assert( pExpr->op!=TK_LE || op==OP_Gt );
4950 assert( pExpr->op!=TK_GT || op==OP_Le );
4951 assert( pExpr->op!=TK_GE || op==OP_Lt );
4952
4953 switch( pExpr->op ){
4954 case TK_AND:
4955 case TK_OR: {
4956 Expr *pAlt = sqlite3ExprSimplifiedAndOr(pExpr);
4957 if( pAlt!=pExpr ){
4958 sqlite3ExprIfFalse(pParse, pAlt, dest, jumpIfNull);
4959 }else if( pExpr->op==TK_AND ){
4960 testcase( jumpIfNull==0 );
4961 sqlite3ExprIfFalse(pParse, pExpr->pLeft, dest, jumpIfNull);
4962 sqlite3ExprIfFalse(pParse, pExpr->pRight, dest, jumpIfNull);
4963 }else{
4964 int d2 = sqlite3VdbeMakeLabel(pParse);
4965 testcase( jumpIfNull==0 );
4966 sqlite3ExprIfTrue(pParse, pExpr->pLeft, d2,
4967 jumpIfNull^SQLITE_JUMPIFNULL);
4968 sqlite3ExprIfFalse(pParse, pExpr->pRight, dest, jumpIfNull);
4969 sqlite3VdbeResolveLabel(v, d2);
4970 }
4971 break;
4972 }
4973 case TK_NOT: {
4974 testcase( jumpIfNull==0 );
4975 sqlite3ExprIfTrue(pParse, pExpr->pLeft, dest, jumpIfNull);
4976 break;
4977 }
4978 case TK_TRUTH: {
4979 int isNot; /* IS NOT TRUE or IS NOT FALSE */
4980 int isTrue; /* IS TRUE or IS NOT TRUE */
4981 testcase( jumpIfNull==0 );
4982 isNot = pExpr->op2==TK_ISNOT;
4983 isTrue = sqlite3ExprTruthValue(pExpr->pRight);
4984 testcase( isTrue && isNot );
4985 testcase( !isTrue && isNot );
4986 if( isTrue ^ isNot ){
4987 /* IS TRUE and IS NOT FALSE */
4988 sqlite3ExprIfFalse(pParse, pExpr->pLeft, dest,
4989 isNot ? 0 : SQLITE_JUMPIFNULL);
4990
4991 }else{
4992 /* IS FALSE and IS NOT TRUE */
4993 sqlite3ExprIfTrue(pParse, pExpr->pLeft, dest,
4994 isNot ? 0 : SQLITE_JUMPIFNULL);
4995 }
4996 break;
4997 }
4998 case TK_IS:
4999 case TK_ISNOT:
5000 testcase( pExpr->op==TK_IS );
5001 testcase( pExpr->op==TK_ISNOT );
5002 op = (pExpr->op==TK_IS) ? TK_NE : TK_EQ;
5003 jumpIfNull = SQLITE_NULLEQ;
5004 /* Fall thru */
5005 case TK_LT:
5006 case TK_LE:
5007 case TK_GT:
5008 case TK_GE:
5009 case TK_NE:
5010 case TK_EQ: {
5011 if( sqlite3ExprIsVector(pExpr->pLeft) ) goto default_expr;
5012 testcase( jumpIfNull==0 );
5013 r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free1);
5014 r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, ®Free2);
5015 codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op,
5016 r1, r2, dest, jumpIfNull,ExprHasProperty(pExpr,EP_Commuted));
5017 assert(TK_LT==OP_Lt); testcase(op==OP_Lt); VdbeCoverageIf(v,op==OP_Lt);
5018 assert(TK_LE==OP_Le); testcase(op==OP_Le); VdbeCoverageIf(v,op==OP_Le);
5019 assert(TK_GT==OP_Gt); testcase(op==OP_Gt); VdbeCoverageIf(v,op==OP_Gt);
5020 assert(TK_GE==OP_Ge); testcase(op==OP_Ge); VdbeCoverageIf(v,op==OP_Ge);
5021 assert(TK_EQ==OP_Eq); testcase(op==OP_Eq);
5022 VdbeCoverageIf(v, op==OP_Eq && jumpIfNull!=SQLITE_NULLEQ);
5023 VdbeCoverageIf(v, op==OP_Eq && jumpIfNull==SQLITE_NULLEQ);
5024 assert(TK_NE==OP_Ne); testcase(op==OP_Ne);
5025 VdbeCoverageIf(v, op==OP_Ne && jumpIfNull!=SQLITE_NULLEQ);
5026 VdbeCoverageIf(v, op==OP_Ne && jumpIfNull==SQLITE_NULLEQ);
5027 testcase( regFree1==0 );
5028 testcase( regFree2==0 );
5029 break;
5030 }
5031 case TK_ISNULL:
5032 case TK_NOTNULL: {
5033 r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free1);
5034 sqlite3VdbeAddOp2(v, op, r1, dest);
5035 testcase( op==TK_ISNULL ); VdbeCoverageIf(v, op==TK_ISNULL);
5036 testcase( op==TK_NOTNULL ); VdbeCoverageIf(v, op==TK_NOTNULL);
5037 testcase( regFree1==0 );
5038 break;
5039 }
5040 case TK_BETWEEN: {
5041 testcase( jumpIfNull==0 );
5042 exprCodeBetween(pParse, pExpr, dest, sqlite3ExprIfFalse, jumpIfNull);
5043 break;
5044 }
5045 #ifndef SQLITE_OMIT_SUBQUERY
5046 case TK_IN: {
5047 if( jumpIfNull ){
5048 sqlite3ExprCodeIN(pParse, pExpr, dest, dest);
5049 }else{
5050 int destIfNull = sqlite3VdbeMakeLabel(pParse);
5051 sqlite3ExprCodeIN(pParse, pExpr, dest, destIfNull);
5052 sqlite3VdbeResolveLabel(v, destIfNull);
5053 }
5054 break;
5055 }
5056 #endif
5057 default: {
5058 default_expr:
5059 if( ExprAlwaysFalse(pExpr) ){
5060 sqlite3VdbeGoto(v, dest);
5061 }else if( ExprAlwaysTrue(pExpr) ){
5062 /* no-op */
5063 }else{
5064 r1 = sqlite3ExprCodeTemp(pParse, pExpr, ®Free1);
5065 sqlite3VdbeAddOp3(v, OP_IfNot, r1, dest, jumpIfNull!=0);
5066 VdbeCoverage(v);
5067 testcase( regFree1==0 );
5068 testcase( jumpIfNull==0 );
5069 }
5070 break;
5071 }
5072 }
5073 sqlite3ReleaseTempReg(pParse, regFree1);
5074 sqlite3ReleaseTempReg(pParse, regFree2);
5075 }
5076
5077 /*
5078 ** Like sqlite3ExprIfFalse() except that a copy is made of pExpr before
5079 ** code generation, and that copy is deleted after code generation. This
5080 ** ensures that the original pExpr is unchanged.
5081 */
sqlite3ExprIfFalseDup(Parse * pParse,Expr * pExpr,int dest,int jumpIfNull)5082 void sqlite3ExprIfFalseDup(Parse *pParse, Expr *pExpr, int dest,int jumpIfNull){
5083 sqlite3 *db = pParse->db;
5084 Expr *pCopy = sqlite3ExprDup(db, pExpr, 0);
5085 if( db->mallocFailed==0 ){
5086 sqlite3ExprIfFalse(pParse, pCopy, dest, jumpIfNull);
5087 }
5088 sqlite3ExprDelete(db, pCopy);
5089 }
5090
5091 /*
5092 ** Expression pVar is guaranteed to be an SQL variable. pExpr may be any
5093 ** type of expression.
5094 **
5095 ** If pExpr is a simple SQL value - an integer, real, string, blob
5096 ** or NULL value - then the VDBE currently being prepared is configured
5097 ** to re-prepare each time a new value is bound to variable pVar.
5098 **
5099 ** Additionally, if pExpr is a simple SQL value and the value is the
5100 ** same as that currently bound to variable pVar, non-zero is returned.
5101 ** Otherwise, if the values are not the same or if pExpr is not a simple
5102 ** SQL value, zero is returned.
5103 */
exprCompareVariable(Parse * pParse,Expr * pVar,Expr * pExpr)5104 static int exprCompareVariable(Parse *pParse, Expr *pVar, Expr *pExpr){
5105 int res = 0;
5106 int iVar;
5107 sqlite3_value *pL, *pR = 0;
5108
5109 sqlite3ValueFromExpr(pParse->db, pExpr, SQLITE_UTF8, SQLITE_AFF_BLOB, &pR);
5110 if( pR ){
5111 iVar = pVar->iColumn;
5112 sqlite3VdbeSetVarmask(pParse->pVdbe, iVar);
5113 pL = sqlite3VdbeGetBoundValue(pParse->pReprepare, iVar, SQLITE_AFF_BLOB);
5114 if( pL ){
5115 if( sqlite3_value_type(pL)==SQLITE_TEXT ){
5116 sqlite3_value_text(pL); /* Make sure the encoding is UTF-8 */
5117 }
5118 res = 0==sqlite3MemCompare(pL, pR, 0);
5119 }
5120 sqlite3ValueFree(pR);
5121 sqlite3ValueFree(pL);
5122 }
5123
5124 return res;
5125 }
5126
5127 /*
5128 ** Do a deep comparison of two expression trees. Return 0 if the two
5129 ** expressions are completely identical. Return 1 if they differ only
5130 ** by a COLLATE operator at the top level. Return 2 if there are differences
5131 ** other than the top-level COLLATE operator.
5132 **
5133 ** If any subelement of pB has Expr.iTable==(-1) then it is allowed
5134 ** to compare equal to an equivalent element in pA with Expr.iTable==iTab.
5135 **
5136 ** The pA side might be using TK_REGISTER. If that is the case and pB is
5137 ** not using TK_REGISTER but is otherwise equivalent, then still return 0.
5138 **
5139 ** Sometimes this routine will return 2 even if the two expressions
5140 ** really are equivalent. If we cannot prove that the expressions are
5141 ** identical, we return 2 just to be safe. So if this routine
5142 ** returns 2, then you do not really know for certain if the two
5143 ** expressions are the same. But if you get a 0 or 1 return, then you
5144 ** can be sure the expressions are the same. In the places where
5145 ** this routine is used, it does not hurt to get an extra 2 - that
5146 ** just might result in some slightly slower code. But returning
5147 ** an incorrect 0 or 1 could lead to a malfunction.
5148 **
5149 ** If pParse is not NULL then TK_VARIABLE terms in pA with bindings in
5150 ** pParse->pReprepare can be matched against literals in pB. The
5151 ** pParse->pVdbe->expmask bitmask is updated for each variable referenced.
5152 ** If pParse is NULL (the normal case) then any TK_VARIABLE term in
5153 ** Argument pParse should normally be NULL. If it is not NULL and pA or
5154 ** pB causes a return value of 2.
5155 */
sqlite3ExprCompare(Parse * pParse,Expr * pA,Expr * pB,int iTab)5156 int sqlite3ExprCompare(Parse *pParse, Expr *pA, Expr *pB, int iTab){
5157 u32 combinedFlags;
5158 if( pA==0 || pB==0 ){
5159 return pB==pA ? 0 : 2;
5160 }
5161 if( pParse && pA->op==TK_VARIABLE && exprCompareVariable(pParse, pA, pB) ){
5162 return 0;
5163 }
5164 combinedFlags = pA->flags | pB->flags;
5165 if( combinedFlags & EP_IntValue ){
5166 if( (pA->flags&pB->flags&EP_IntValue)!=0 && pA->u.iValue==pB->u.iValue ){
5167 return 0;
5168 }
5169 return 2;
5170 }
5171 if( pA->op!=pB->op || pA->op==TK_RAISE ){
5172 if( pA->op==TK_COLLATE && sqlite3ExprCompare(pParse, pA->pLeft,pB,iTab)<2 ){
5173 return 1;
5174 }
5175 if( pB->op==TK_COLLATE && sqlite3ExprCompare(pParse, pA,pB->pLeft,iTab)<2 ){
5176 return 1;
5177 }
5178 return 2;
5179 }
5180 if( pA->op!=TK_COLUMN && pA->op!=TK_AGG_COLUMN && pA->u.zToken ){
5181 if( pA->op==TK_FUNCTION || pA->op==TK_AGG_FUNCTION ){
5182 if( sqlite3StrICmp(pA->u.zToken,pB->u.zToken)!=0 ) return 2;
5183 #ifndef SQLITE_OMIT_WINDOWFUNC
5184 assert( pA->op==pB->op );
5185 if( ExprHasProperty(pA,EP_WinFunc)!=ExprHasProperty(pB,EP_WinFunc) ){
5186 return 2;
5187 }
5188 if( ExprHasProperty(pA,EP_WinFunc) ){
5189 if( sqlite3WindowCompare(pParse, pA->y.pWin, pB->y.pWin, 1)!=0 ){
5190 return 2;
5191 }
5192 }
5193 #endif
5194 }else if( pA->op==TK_NULL ){
5195 return 0;
5196 }else if( pA->op==TK_COLLATE ){
5197 if( sqlite3_stricmp(pA->u.zToken,pB->u.zToken)!=0 ) return 2;
5198 }else if( ALWAYS(pB->u.zToken!=0) && strcmp(pA->u.zToken,pB->u.zToken)!=0 ){
5199 return 2;
5200 }
5201 }
5202 if( (pA->flags & (EP_Distinct|EP_Commuted))
5203 != (pB->flags & (EP_Distinct|EP_Commuted)) ) return 2;
5204 if( (combinedFlags & EP_TokenOnly)==0 ){
5205 if( combinedFlags & EP_xIsSelect ) return 2;
5206 if( (combinedFlags & EP_FixedCol)==0
5207 && sqlite3ExprCompare(pParse, pA->pLeft, pB->pLeft, iTab) ) return 2;
5208 if( sqlite3ExprCompare(pParse, pA->pRight, pB->pRight, iTab) ) return 2;
5209 if( sqlite3ExprListCompare(pA->x.pList, pB->x.pList, iTab) ) return 2;
5210 if( pA->op!=TK_STRING
5211 && pA->op!=TK_TRUEFALSE
5212 && (combinedFlags & EP_Reduced)==0
5213 ){
5214 if( pA->iColumn!=pB->iColumn ) return 2;
5215 if( pA->op2!=pB->op2 ){
5216 if( pA->op==TK_TRUTH ) return 2;
5217 if( pA->op==TK_FUNCTION && iTab<0 ){
5218 /* Ex: CREATE TABLE t1(a CHECK( a<julianday('now') ));
5219 ** INSERT INTO t1(a) VALUES(julianday('now')+10);
5220 ** Without this test, sqlite3ExprCodeAtInit() will run on the
5221 ** the julianday() of INSERT first, and remember that expression.
5222 ** Then sqlite3ExprCodeInit() will see the julianday() in the CHECK
5223 ** constraint as redundant, reusing the one from the INSERT, even
5224 ** though the julianday() in INSERT lacks the critical NC_IsCheck
5225 ** flag. See ticket [830277d9db6c3ba1] (2019-10-30)
5226 */
5227 return 2;
5228 }
5229 }
5230 if( pA->op!=TK_IN && pA->iTable!=pB->iTable && pA->iTable!=iTab ){
5231 return 2;
5232 }
5233 }
5234 }
5235 return 0;
5236 }
5237
5238 /*
5239 ** Compare two ExprList objects. Return 0 if they are identical, 1
5240 ** if they are certainly different, or 2 if it is not possible to
5241 ** determine if they are identical or not.
5242 **
5243 ** If any subelement of pB has Expr.iTable==(-1) then it is allowed
5244 ** to compare equal to an equivalent element in pA with Expr.iTable==iTab.
5245 **
5246 ** This routine might return non-zero for equivalent ExprLists. The
5247 ** only consequence will be disabled optimizations. But this routine
5248 ** must never return 0 if the two ExprList objects are different, or
5249 ** a malfunction will result.
5250 **
5251 ** Two NULL pointers are considered to be the same. But a NULL pointer
5252 ** always differs from a non-NULL pointer.
5253 */
sqlite3ExprListCompare(ExprList * pA,ExprList * pB,int iTab)5254 int sqlite3ExprListCompare(ExprList *pA, ExprList *pB, int iTab){
5255 int i;
5256 if( pA==0 && pB==0 ) return 0;
5257 if( pA==0 || pB==0 ) return 1;
5258 if( pA->nExpr!=pB->nExpr ) return 1;
5259 for(i=0; i<pA->nExpr; i++){
5260 int res;
5261 Expr *pExprA = pA->a[i].pExpr;
5262 Expr *pExprB = pB->a[i].pExpr;
5263 if( pA->a[i].sortFlags!=pB->a[i].sortFlags ) return 1;
5264 if( (res = sqlite3ExprCompare(0, pExprA, pExprB, iTab)) ) return res;
5265 }
5266 return 0;
5267 }
5268
5269 /*
5270 ** Like sqlite3ExprCompare() except COLLATE operators at the top-level
5271 ** are ignored.
5272 */
sqlite3ExprCompareSkip(Expr * pA,Expr * pB,int iTab)5273 int sqlite3ExprCompareSkip(Expr *pA, Expr *pB, int iTab){
5274 return sqlite3ExprCompare(0,
5275 sqlite3ExprSkipCollateAndLikely(pA),
5276 sqlite3ExprSkipCollateAndLikely(pB),
5277 iTab);
5278 }
5279
5280 /*
5281 ** Return non-zero if Expr p can only be true if pNN is not NULL.
5282 **
5283 ** Or if seenNot is true, return non-zero if Expr p can only be
5284 ** non-NULL if pNN is not NULL
5285 */
exprImpliesNotNull(Parse * pParse,Expr * p,Expr * pNN,int iTab,int seenNot)5286 static int exprImpliesNotNull(
5287 Parse *pParse, /* Parsing context */
5288 Expr *p, /* The expression to be checked */
5289 Expr *pNN, /* The expression that is NOT NULL */
5290 int iTab, /* Table being evaluated */
5291 int seenNot /* Return true only if p can be any non-NULL value */
5292 ){
5293 assert( p );
5294 assert( pNN );
5295 if( sqlite3ExprCompare(pParse, p, pNN, iTab)==0 ){
5296 return pNN->op!=TK_NULL;
5297 }
5298 switch( p->op ){
5299 case TK_IN: {
5300 if( seenNot && ExprHasProperty(p, EP_xIsSelect) ) return 0;
5301 assert( ExprHasProperty(p,EP_xIsSelect)
5302 || (p->x.pList!=0 && p->x.pList->nExpr>0) );
5303 return exprImpliesNotNull(pParse, p->pLeft, pNN, iTab, 1);
5304 }
5305 case TK_BETWEEN: {
5306 ExprList *pList = p->x.pList;
5307 assert( pList!=0 );
5308 assert( pList->nExpr==2 );
5309 if( seenNot ) return 0;
5310 if( exprImpliesNotNull(pParse, pList->a[0].pExpr, pNN, iTab, 1)
5311 || exprImpliesNotNull(pParse, pList->a[1].pExpr, pNN, iTab, 1)
5312 ){
5313 return 1;
5314 }
5315 return exprImpliesNotNull(pParse, p->pLeft, pNN, iTab, 1);
5316 }
5317 case TK_EQ:
5318 case TK_NE:
5319 case TK_LT:
5320 case TK_LE:
5321 case TK_GT:
5322 case TK_GE:
5323 case TK_PLUS:
5324 case TK_MINUS:
5325 case TK_BITOR:
5326 case TK_LSHIFT:
5327 case TK_RSHIFT:
5328 case TK_CONCAT:
5329 seenNot = 1;
5330 /* Fall thru */
5331 case TK_STAR:
5332 case TK_REM:
5333 case TK_BITAND:
5334 case TK_SLASH: {
5335 if( exprImpliesNotNull(pParse, p->pRight, pNN, iTab, seenNot) ) return 1;
5336 /* Fall thru into the next case */
5337 }
5338 case TK_SPAN:
5339 case TK_COLLATE:
5340 case TK_UPLUS:
5341 case TK_UMINUS: {
5342 return exprImpliesNotNull(pParse, p->pLeft, pNN, iTab, seenNot);
5343 }
5344 case TK_TRUTH: {
5345 if( seenNot ) return 0;
5346 if( p->op2!=TK_IS ) return 0;
5347 return exprImpliesNotNull(pParse, p->pLeft, pNN, iTab, 1);
5348 }
5349 case TK_BITNOT:
5350 case TK_NOT: {
5351 return exprImpliesNotNull(pParse, p->pLeft, pNN, iTab, 1);
5352 }
5353 }
5354 return 0;
5355 }
5356
5357 /*
5358 ** Return true if we can prove the pE2 will always be true if pE1 is
5359 ** true. Return false if we cannot complete the proof or if pE2 might
5360 ** be false. Examples:
5361 **
5362 ** pE1: x==5 pE2: x==5 Result: true
5363 ** pE1: x>0 pE2: x==5 Result: false
5364 ** pE1: x=21 pE2: x=21 OR y=43 Result: true
5365 ** pE1: x!=123 pE2: x IS NOT NULL Result: true
5366 ** pE1: x!=?1 pE2: x IS NOT NULL Result: true
5367 ** pE1: x IS NULL pE2: x IS NOT NULL Result: false
5368 ** pE1: x IS ?2 pE2: x IS NOT NULL Reuslt: false
5369 **
5370 ** When comparing TK_COLUMN nodes between pE1 and pE2, if pE2 has
5371 ** Expr.iTable<0 then assume a table number given by iTab.
5372 **
5373 ** If pParse is not NULL, then the values of bound variables in pE1 are
5374 ** compared against literal values in pE2 and pParse->pVdbe->expmask is
5375 ** modified to record which bound variables are referenced. If pParse
5376 ** is NULL, then false will be returned if pE1 contains any bound variables.
5377 **
5378 ** When in doubt, return false. Returning true might give a performance
5379 ** improvement. Returning false might cause a performance reduction, but
5380 ** it will always give the correct answer and is hence always safe.
5381 */
sqlite3ExprImpliesExpr(Parse * pParse,Expr * pE1,Expr * pE2,int iTab)5382 int sqlite3ExprImpliesExpr(Parse *pParse, Expr *pE1, Expr *pE2, int iTab){
5383 if( sqlite3ExprCompare(pParse, pE1, pE2, iTab)==0 ){
5384 return 1;
5385 }
5386 if( pE2->op==TK_OR
5387 && (sqlite3ExprImpliesExpr(pParse, pE1, pE2->pLeft, iTab)
5388 || sqlite3ExprImpliesExpr(pParse, pE1, pE2->pRight, iTab) )
5389 ){
5390 return 1;
5391 }
5392 if( pE2->op==TK_NOTNULL
5393 && exprImpliesNotNull(pParse, pE1, pE2->pLeft, iTab, 0)
5394 ){
5395 return 1;
5396 }
5397 return 0;
5398 }
5399
5400 /*
5401 ** This is the Expr node callback for sqlite3ExprImpliesNonNullRow().
5402 ** If the expression node requires that the table at pWalker->iCur
5403 ** have one or more non-NULL column, then set pWalker->eCode to 1 and abort.
5404 **
5405 ** This routine controls an optimization. False positives (setting
5406 ** pWalker->eCode to 1 when it should not be) are deadly, but false-negatives
5407 ** (never setting pWalker->eCode) is a harmless missed optimization.
5408 */
impliesNotNullRow(Walker * pWalker,Expr * pExpr)5409 static int impliesNotNullRow(Walker *pWalker, Expr *pExpr){
5410 testcase( pExpr->op==TK_AGG_COLUMN );
5411 testcase( pExpr->op==TK_AGG_FUNCTION );
5412 if( ExprHasProperty(pExpr, EP_FromJoin) ) return WRC_Prune;
5413 switch( pExpr->op ){
5414 case TK_ISNOT:
5415 case TK_ISNULL:
5416 case TK_NOTNULL:
5417 case TK_IS:
5418 case TK_OR:
5419 case TK_VECTOR:
5420 case TK_CASE:
5421 case TK_IN:
5422 case TK_FUNCTION:
5423 case TK_TRUTH:
5424 testcase( pExpr->op==TK_ISNOT );
5425 testcase( pExpr->op==TK_ISNULL );
5426 testcase( pExpr->op==TK_NOTNULL );
5427 testcase( pExpr->op==TK_IS );
5428 testcase( pExpr->op==TK_OR );
5429 testcase( pExpr->op==TK_VECTOR );
5430 testcase( pExpr->op==TK_CASE );
5431 testcase( pExpr->op==TK_IN );
5432 testcase( pExpr->op==TK_FUNCTION );
5433 testcase( pExpr->op==TK_TRUTH );
5434 return WRC_Prune;
5435 case TK_COLUMN:
5436 if( pWalker->u.iCur==pExpr->iTable ){
5437 pWalker->eCode = 1;
5438 return WRC_Abort;
5439 }
5440 return WRC_Prune;
5441
5442 case TK_AND:
5443 if( pWalker->eCode==0 ){
5444 sqlite3WalkExpr(pWalker, pExpr->pLeft);
5445 if( pWalker->eCode ){
5446 pWalker->eCode = 0;
5447 sqlite3WalkExpr(pWalker, pExpr->pRight);
5448 }
5449 }
5450 return WRC_Prune;
5451
5452 case TK_BETWEEN:
5453 if( sqlite3WalkExpr(pWalker, pExpr->pLeft)==WRC_Abort ){
5454 assert( pWalker->eCode );
5455 return WRC_Abort;
5456 }
5457 return WRC_Prune;
5458
5459 /* Virtual tables are allowed to use constraints like x=NULL. So
5460 ** a term of the form x=y does not prove that y is not null if x
5461 ** is the column of a virtual table */
5462 case TK_EQ:
5463 case TK_NE:
5464 case TK_LT:
5465 case TK_LE:
5466 case TK_GT:
5467 case TK_GE: {
5468 Expr *pLeft = pExpr->pLeft;
5469 Expr *pRight = pExpr->pRight;
5470 testcase( pExpr->op==TK_EQ );
5471 testcase( pExpr->op==TK_NE );
5472 testcase( pExpr->op==TK_LT );
5473 testcase( pExpr->op==TK_LE );
5474 testcase( pExpr->op==TK_GT );
5475 testcase( pExpr->op==TK_GE );
5476 /* The y.pTab=0 assignment in wherecode.c always happens after the
5477 ** impliesNotNullRow() test */
5478 if( (pLeft->op==TK_COLUMN && ALWAYS(pLeft->y.pTab!=0)
5479 && IsVirtual(pLeft->y.pTab))
5480 || (pRight->op==TK_COLUMN && ALWAYS(pRight->y.pTab!=0)
5481 && IsVirtual(pRight->y.pTab))
5482 ){
5483 return WRC_Prune;
5484 }
5485 }
5486 default:
5487 return WRC_Continue;
5488 }
5489 }
5490
5491 /*
5492 ** Return true (non-zero) if expression p can only be true if at least
5493 ** one column of table iTab is non-null. In other words, return true
5494 ** if expression p will always be NULL or false if every column of iTab
5495 ** is NULL.
5496 **
5497 ** False negatives are acceptable. In other words, it is ok to return
5498 ** zero even if expression p will never be true of every column of iTab
5499 ** is NULL. A false negative is merely a missed optimization opportunity.
5500 **
5501 ** False positives are not allowed, however. A false positive may result
5502 ** in an incorrect answer.
5503 **
5504 ** Terms of p that are marked with EP_FromJoin (and hence that come from
5505 ** the ON or USING clauses of LEFT JOINS) are excluded from the analysis.
5506 **
5507 ** This routine is used to check if a LEFT JOIN can be converted into
5508 ** an ordinary JOIN. The p argument is the WHERE clause. If the WHERE
5509 ** clause requires that some column of the right table of the LEFT JOIN
5510 ** be non-NULL, then the LEFT JOIN can be safely converted into an
5511 ** ordinary join.
5512 */
sqlite3ExprImpliesNonNullRow(Expr * p,int iTab)5513 int sqlite3ExprImpliesNonNullRow(Expr *p, int iTab){
5514 Walker w;
5515 p = sqlite3ExprSkipCollateAndLikely(p);
5516 if( p==0 ) return 0;
5517 if( p->op==TK_NOTNULL ){
5518 p = p->pLeft;
5519 }else{
5520 while( p->op==TK_AND ){
5521 if( sqlite3ExprImpliesNonNullRow(p->pLeft, iTab) ) return 1;
5522 p = p->pRight;
5523 }
5524 }
5525 w.xExprCallback = impliesNotNullRow;
5526 w.xSelectCallback = 0;
5527 w.xSelectCallback2 = 0;
5528 w.eCode = 0;
5529 w.u.iCur = iTab;
5530 sqlite3WalkExpr(&w, p);
5531 return w.eCode;
5532 }
5533
5534 /*
5535 ** An instance of the following structure is used by the tree walker
5536 ** to determine if an expression can be evaluated by reference to the
5537 ** index only, without having to do a search for the corresponding
5538 ** table entry. The IdxCover.pIdx field is the index. IdxCover.iCur
5539 ** is the cursor for the table.
5540 */
5541 struct IdxCover {
5542 Index *pIdx; /* The index to be tested for coverage */
5543 int iCur; /* Cursor number for the table corresponding to the index */
5544 };
5545
5546 /*
5547 ** Check to see if there are references to columns in table
5548 ** pWalker->u.pIdxCover->iCur can be satisfied using the index
5549 ** pWalker->u.pIdxCover->pIdx.
5550 */
exprIdxCover(Walker * pWalker,Expr * pExpr)5551 static int exprIdxCover(Walker *pWalker, Expr *pExpr){
5552 if( pExpr->op==TK_COLUMN
5553 && pExpr->iTable==pWalker->u.pIdxCover->iCur
5554 && sqlite3TableColumnToIndex(pWalker->u.pIdxCover->pIdx, pExpr->iColumn)<0
5555 ){
5556 pWalker->eCode = 1;
5557 return WRC_Abort;
5558 }
5559 return WRC_Continue;
5560 }
5561
5562 /*
5563 ** Determine if an index pIdx on table with cursor iCur contains will
5564 ** the expression pExpr. Return true if the index does cover the
5565 ** expression and false if the pExpr expression references table columns
5566 ** that are not found in the index pIdx.
5567 **
5568 ** An index covering an expression means that the expression can be
5569 ** evaluated using only the index and without having to lookup the
5570 ** corresponding table entry.
5571 */
sqlite3ExprCoveredByIndex(Expr * pExpr,int iCur,Index * pIdx)5572 int sqlite3ExprCoveredByIndex(
5573 Expr *pExpr, /* The index to be tested */
5574 int iCur, /* The cursor number for the corresponding table */
5575 Index *pIdx /* The index that might be used for coverage */
5576 ){
5577 Walker w;
5578 struct IdxCover xcov;
5579 memset(&w, 0, sizeof(w));
5580 xcov.iCur = iCur;
5581 xcov.pIdx = pIdx;
5582 w.xExprCallback = exprIdxCover;
5583 w.u.pIdxCover = &xcov;
5584 sqlite3WalkExpr(&w, pExpr);
5585 return !w.eCode;
5586 }
5587
5588
5589 /*
5590 ** An instance of the following structure is used by the tree walker
5591 ** to count references to table columns in the arguments of an
5592 ** aggregate function, in order to implement the
5593 ** sqlite3FunctionThisSrc() routine.
5594 */
5595 struct SrcCount {
5596 SrcList *pSrc; /* One particular FROM clause in a nested query */
5597 int nThis; /* Number of references to columns in pSrcList */
5598 int nOther; /* Number of references to columns in other FROM clauses */
5599 };
5600
5601 /*
5602 ** Count the number of references to columns.
5603 */
exprSrcCount(Walker * pWalker,Expr * pExpr)5604 static int exprSrcCount(Walker *pWalker, Expr *pExpr){
5605 /* There was once a NEVER() on the second term on the grounds that
5606 ** sqlite3FunctionUsesThisSrc() was always called before
5607 ** sqlite3ExprAnalyzeAggregates() and so the TK_COLUMNs have not yet
5608 ** been converted into TK_AGG_COLUMN. But this is no longer true due
5609 ** to window functions - sqlite3WindowRewrite() may now indirectly call
5610 ** FunctionUsesThisSrc() when creating a new sub-select. */
5611 if( pExpr->op==TK_COLUMN || pExpr->op==TK_AGG_COLUMN ){
5612 int i;
5613 struct SrcCount *p = pWalker->u.pSrcCount;
5614 SrcList *pSrc = p->pSrc;
5615 int nSrc = pSrc ? pSrc->nSrc : 0;
5616 for(i=0; i<nSrc; i++){
5617 if( pExpr->iTable==pSrc->a[i].iCursor ) break;
5618 }
5619 if( i<nSrc ){
5620 p->nThis++;
5621 }else if( nSrc==0 || pExpr->iTable<pSrc->a[0].iCursor ){
5622 /* In a well-formed parse tree (no name resolution errors),
5623 ** TK_COLUMN nodes with smaller Expr.iTable values are in an
5624 ** outer context. Those are the only ones to count as "other" */
5625 p->nOther++;
5626 }
5627 }
5628 return WRC_Continue;
5629 }
5630
5631 /*
5632 ** Determine if any of the arguments to the pExpr Function reference
5633 ** pSrcList. Return true if they do. Also return true if the function
5634 ** has no arguments or has only constant arguments. Return false if pExpr
5635 ** references columns but not columns of tables found in pSrcList.
5636 */
sqlite3FunctionUsesThisSrc(Expr * pExpr,SrcList * pSrcList)5637 int sqlite3FunctionUsesThisSrc(Expr *pExpr, SrcList *pSrcList){
5638 Walker w;
5639 struct SrcCount cnt;
5640 assert( pExpr->op==TK_AGG_FUNCTION );
5641 memset(&w, 0, sizeof(w));
5642 w.xExprCallback = exprSrcCount;
5643 w.xSelectCallback = sqlite3SelectWalkNoop;
5644 w.u.pSrcCount = &cnt;
5645 cnt.pSrc = pSrcList;
5646 cnt.nThis = 0;
5647 cnt.nOther = 0;
5648 sqlite3WalkExprList(&w, pExpr->x.pList);
5649 #ifndef SQLITE_OMIT_WINDOWFUNC
5650 if( ExprHasProperty(pExpr, EP_WinFunc) ){
5651 sqlite3WalkExpr(&w, pExpr->y.pWin->pFilter);
5652 }
5653 #endif
5654 return cnt.nThis>0 || cnt.nOther==0;
5655 }
5656
5657 /*
5658 ** Add a new element to the pAggInfo->aCol[] array. Return the index of
5659 ** the new element. Return a negative number if malloc fails.
5660 */
addAggInfoColumn(sqlite3 * db,AggInfo * pInfo)5661 static int addAggInfoColumn(sqlite3 *db, AggInfo *pInfo){
5662 int i;
5663 pInfo->aCol = sqlite3ArrayAllocate(
5664 db,
5665 pInfo->aCol,
5666 sizeof(pInfo->aCol[0]),
5667 &pInfo->nColumn,
5668 &i
5669 );
5670 return i;
5671 }
5672
5673 /*
5674 ** Add a new element to the pAggInfo->aFunc[] array. Return the index of
5675 ** the new element. Return a negative number if malloc fails.
5676 */
addAggInfoFunc(sqlite3 * db,AggInfo * pInfo)5677 static int addAggInfoFunc(sqlite3 *db, AggInfo *pInfo){
5678 int i;
5679 pInfo->aFunc = sqlite3ArrayAllocate(
5680 db,
5681 pInfo->aFunc,
5682 sizeof(pInfo->aFunc[0]),
5683 &pInfo->nFunc,
5684 &i
5685 );
5686 return i;
5687 }
5688
5689 /*
5690 ** This is the xExprCallback for a tree walker. It is used to
5691 ** implement sqlite3ExprAnalyzeAggregates(). See sqlite3ExprAnalyzeAggregates
5692 ** for additional information.
5693 */
analyzeAggregate(Walker * pWalker,Expr * pExpr)5694 static int analyzeAggregate(Walker *pWalker, Expr *pExpr){
5695 int i;
5696 NameContext *pNC = pWalker->u.pNC;
5697 Parse *pParse = pNC->pParse;
5698 SrcList *pSrcList = pNC->pSrcList;
5699 AggInfo *pAggInfo = pNC->uNC.pAggInfo;
5700
5701 assert( pNC->ncFlags & NC_UAggInfo );
5702 switch( pExpr->op ){
5703 case TK_AGG_COLUMN:
5704 case TK_COLUMN: {
5705 testcase( pExpr->op==TK_AGG_COLUMN );
5706 testcase( pExpr->op==TK_COLUMN );
5707 /* Check to see if the column is in one of the tables in the FROM
5708 ** clause of the aggregate query */
5709 if( ALWAYS(pSrcList!=0) ){
5710 struct SrcList_item *pItem = pSrcList->a;
5711 for(i=0; i<pSrcList->nSrc; i++, pItem++){
5712 struct AggInfo_col *pCol;
5713 assert( !ExprHasProperty(pExpr, EP_TokenOnly|EP_Reduced) );
5714 if( pExpr->iTable==pItem->iCursor ){
5715 /* If we reach this point, it means that pExpr refers to a table
5716 ** that is in the FROM clause of the aggregate query.
5717 **
5718 ** Make an entry for the column in pAggInfo->aCol[] if there
5719 ** is not an entry there already.
5720 */
5721 int k;
5722 pCol = pAggInfo->aCol;
5723 for(k=0; k<pAggInfo->nColumn; k++, pCol++){
5724 if( pCol->iTable==pExpr->iTable &&
5725 pCol->iColumn==pExpr->iColumn ){
5726 break;
5727 }
5728 }
5729 if( (k>=pAggInfo->nColumn)
5730 && (k = addAggInfoColumn(pParse->db, pAggInfo))>=0
5731 ){
5732 pCol = &pAggInfo->aCol[k];
5733 pCol->pTab = pExpr->y.pTab;
5734 pCol->iTable = pExpr->iTable;
5735 pCol->iColumn = pExpr->iColumn;
5736 pCol->iMem = ++pParse->nMem;
5737 pCol->iSorterColumn = -1;
5738 pCol->pExpr = pExpr;
5739 if( pAggInfo->pGroupBy ){
5740 int j, n;
5741 ExprList *pGB = pAggInfo->pGroupBy;
5742 struct ExprList_item *pTerm = pGB->a;
5743 n = pGB->nExpr;
5744 for(j=0; j<n; j++, pTerm++){
5745 Expr *pE = pTerm->pExpr;
5746 if( pE->op==TK_COLUMN && pE->iTable==pExpr->iTable &&
5747 pE->iColumn==pExpr->iColumn ){
5748 pCol->iSorterColumn = j;
5749 break;
5750 }
5751 }
5752 }
5753 if( pCol->iSorterColumn<0 ){
5754 pCol->iSorterColumn = pAggInfo->nSortingColumn++;
5755 }
5756 }
5757 /* There is now an entry for pExpr in pAggInfo->aCol[] (either
5758 ** because it was there before or because we just created it).
5759 ** Convert the pExpr to be a TK_AGG_COLUMN referring to that
5760 ** pAggInfo->aCol[] entry.
5761 */
5762 ExprSetVVAProperty(pExpr, EP_NoReduce);
5763 pExpr->pAggInfo = pAggInfo;
5764 pExpr->op = TK_AGG_COLUMN;
5765 pExpr->iAgg = (i16)k;
5766 break;
5767 } /* endif pExpr->iTable==pItem->iCursor */
5768 } /* end loop over pSrcList */
5769 }
5770 return WRC_Prune;
5771 }
5772 case TK_AGG_FUNCTION: {
5773 if( (pNC->ncFlags & NC_InAggFunc)==0
5774 && pWalker->walkerDepth==pExpr->op2
5775 ){
5776 /* Check to see if pExpr is a duplicate of another aggregate
5777 ** function that is already in the pAggInfo structure
5778 */
5779 struct AggInfo_func *pItem = pAggInfo->aFunc;
5780 for(i=0; i<pAggInfo->nFunc; i++, pItem++){
5781 if( sqlite3ExprCompare(0, pItem->pExpr, pExpr, -1)==0 ){
5782 break;
5783 }
5784 }
5785 if( i>=pAggInfo->nFunc ){
5786 /* pExpr is original. Make a new entry in pAggInfo->aFunc[]
5787 */
5788 u8 enc = ENC(pParse->db);
5789 i = addAggInfoFunc(pParse->db, pAggInfo);
5790 if( i>=0 ){
5791 assert( !ExprHasProperty(pExpr, EP_xIsSelect) );
5792 pItem = &pAggInfo->aFunc[i];
5793 pItem->pExpr = pExpr;
5794 pItem->iMem = ++pParse->nMem;
5795 assert( !ExprHasProperty(pExpr, EP_IntValue) );
5796 pItem->pFunc = sqlite3FindFunction(pParse->db,
5797 pExpr->u.zToken,
5798 pExpr->x.pList ? pExpr->x.pList->nExpr : 0, enc, 0);
5799 if( pExpr->flags & EP_Distinct ){
5800 pItem->iDistinct = pParse->nTab++;
5801 }else{
5802 pItem->iDistinct = -1;
5803 }
5804 }
5805 }
5806 /* Make pExpr point to the appropriate pAggInfo->aFunc[] entry
5807 */
5808 assert( !ExprHasProperty(pExpr, EP_TokenOnly|EP_Reduced) );
5809 ExprSetVVAProperty(pExpr, EP_NoReduce);
5810 pExpr->iAgg = (i16)i;
5811 pExpr->pAggInfo = pAggInfo;
5812 return WRC_Prune;
5813 }else{
5814 return WRC_Continue;
5815 }
5816 }
5817 }
5818 return WRC_Continue;
5819 }
analyzeAggregatesInSelect(Walker * pWalker,Select * pSelect)5820 static int analyzeAggregatesInSelect(Walker *pWalker, Select *pSelect){
5821 UNUSED_PARAMETER(pSelect);
5822 pWalker->walkerDepth++;
5823 return WRC_Continue;
5824 }
analyzeAggregatesInSelectEnd(Walker * pWalker,Select * pSelect)5825 static void analyzeAggregatesInSelectEnd(Walker *pWalker, Select *pSelect){
5826 UNUSED_PARAMETER(pSelect);
5827 pWalker->walkerDepth--;
5828 }
5829
5830 /*
5831 ** Analyze the pExpr expression looking for aggregate functions and
5832 ** for variables that need to be added to AggInfo object that pNC->pAggInfo
5833 ** points to. Additional entries are made on the AggInfo object as
5834 ** necessary.
5835 **
5836 ** This routine should only be called after the expression has been
5837 ** analyzed by sqlite3ResolveExprNames().
5838 */
sqlite3ExprAnalyzeAggregates(NameContext * pNC,Expr * pExpr)5839 void sqlite3ExprAnalyzeAggregates(NameContext *pNC, Expr *pExpr){
5840 Walker w;
5841 w.xExprCallback = analyzeAggregate;
5842 w.xSelectCallback = analyzeAggregatesInSelect;
5843 w.xSelectCallback2 = analyzeAggregatesInSelectEnd;
5844 w.walkerDepth = 0;
5845 w.u.pNC = pNC;
5846 w.pParse = 0;
5847 assert( pNC->pSrcList!=0 );
5848 sqlite3WalkExpr(&w, pExpr);
5849 }
5850
5851 /*
5852 ** Call sqlite3ExprAnalyzeAggregates() for every expression in an
5853 ** expression list. Return the number of errors.
5854 **
5855 ** If an error is found, the analysis is cut short.
5856 */
sqlite3ExprAnalyzeAggList(NameContext * pNC,ExprList * pList)5857 void sqlite3ExprAnalyzeAggList(NameContext *pNC, ExprList *pList){
5858 struct ExprList_item *pItem;
5859 int i;
5860 if( pList ){
5861 for(pItem=pList->a, i=0; i<pList->nExpr; i++, pItem++){
5862 sqlite3ExprAnalyzeAggregates(pNC, pItem->pExpr);
5863 }
5864 }
5865 }
5866
5867 /*
5868 ** Allocate a single new register for use to hold some intermediate result.
5869 */
sqlite3GetTempReg(Parse * pParse)5870 int sqlite3GetTempReg(Parse *pParse){
5871 if( pParse->nTempReg==0 ){
5872 return ++pParse->nMem;
5873 }
5874 return pParse->aTempReg[--pParse->nTempReg];
5875 }
5876
5877 /*
5878 ** Deallocate a register, making available for reuse for some other
5879 ** purpose.
5880 */
sqlite3ReleaseTempReg(Parse * pParse,int iReg)5881 void sqlite3ReleaseTempReg(Parse *pParse, int iReg){
5882 if( iReg ){
5883 sqlite3VdbeReleaseRegisters(pParse, iReg, 1, 0, 0);
5884 if( pParse->nTempReg<ArraySize(pParse->aTempReg) ){
5885 pParse->aTempReg[pParse->nTempReg++] = iReg;
5886 }
5887 }
5888 }
5889
5890 /*
5891 ** Allocate or deallocate a block of nReg consecutive registers.
5892 */
sqlite3GetTempRange(Parse * pParse,int nReg)5893 int sqlite3GetTempRange(Parse *pParse, int nReg){
5894 int i, n;
5895 if( nReg==1 ) return sqlite3GetTempReg(pParse);
5896 i = pParse->iRangeReg;
5897 n = pParse->nRangeReg;
5898 if( nReg<=n ){
5899 pParse->iRangeReg += nReg;
5900 pParse->nRangeReg -= nReg;
5901 }else{
5902 i = pParse->nMem+1;
5903 pParse->nMem += nReg;
5904 }
5905 return i;
5906 }
sqlite3ReleaseTempRange(Parse * pParse,int iReg,int nReg)5907 void sqlite3ReleaseTempRange(Parse *pParse, int iReg, int nReg){
5908 if( nReg==1 ){
5909 sqlite3ReleaseTempReg(pParse, iReg);
5910 return;
5911 }
5912 sqlite3VdbeReleaseRegisters(pParse, iReg, nReg, 0, 0);
5913 if( nReg>pParse->nRangeReg ){
5914 pParse->nRangeReg = nReg;
5915 pParse->iRangeReg = iReg;
5916 }
5917 }
5918
5919 /*
5920 ** Mark all temporary registers as being unavailable for reuse.
5921 **
5922 ** Always invoke this procedure after coding a subroutine or co-routine
5923 ** that might be invoked from other parts of the code, to ensure that
5924 ** the sub/co-routine does not use registers in common with the code that
5925 ** invokes the sub/co-routine.
5926 */
sqlite3ClearTempRegCache(Parse * pParse)5927 void sqlite3ClearTempRegCache(Parse *pParse){
5928 pParse->nTempReg = 0;
5929 pParse->nRangeReg = 0;
5930 }
5931
5932 /*
5933 ** Validate that no temporary register falls within the range of
5934 ** iFirst..iLast, inclusive. This routine is only call from within assert()
5935 ** statements.
5936 */
5937 #ifdef SQLITE_DEBUG
sqlite3NoTempsInRange(Parse * pParse,int iFirst,int iLast)5938 int sqlite3NoTempsInRange(Parse *pParse, int iFirst, int iLast){
5939 int i;
5940 if( pParse->nRangeReg>0
5941 && pParse->iRangeReg+pParse->nRangeReg > iFirst
5942 && pParse->iRangeReg <= iLast
5943 ){
5944 return 0;
5945 }
5946 for(i=0; i<pParse->nTempReg; i++){
5947 if( pParse->aTempReg[i]>=iFirst && pParse->aTempReg[i]<=iLast ){
5948 return 0;
5949 }
5950 }
5951 return 1;
5952 }
5953 #endif /* SQLITE_DEBUG */
5954