000001 /*
000002 ** 2001 September 15
000003 **
000004 ** The author disclaims copyright to this source code. In place of
000005 ** a legal notice, here is a blessing:
000006 **
000007 ** May you do good and not evil.
000008 ** May you find forgiveness for yourself and forgive others.
000009 ** May you share freely, never taking more than you give.
000010 **
000011 *************************************************************************
000012 ** This file contains routines used for analyzing expressions and
000013 ** for generating VDBE code that evaluates expressions in SQLite.
000014 */
000015 #include "sqliteInt.h"
000016
000017 /* Forward declarations */
000018 static void exprCodeBetween(Parse*,Expr*,int,void(*)(Parse*,Expr*,int,int),int);
000019 static int exprCodeVector(Parse *pParse, Expr *p, int *piToFree);
000020
000021 /*
000022 ** Return the affinity character for a single column of a table.
000023 */
000024 char sqlite3TableColumnAffinity(const Table *pTab, int iCol){
000025 if( iCol<0 || NEVER(iCol>=pTab->nCol) ) return SQLITE_AFF_INTEGER;
000026 return pTab->aCol[iCol].affinity;
000027 }
000028
000029 /*
000030 ** Return the 'affinity' of the expression pExpr if any.
000031 **
000032 ** If pExpr is a column, a reference to a column via an 'AS' alias,
000033 ** or a sub-select with a column as the return value, then the
000034 ** affinity of that column is returned. Otherwise, 0x00 is returned,
000035 ** indicating no affinity for the expression.
000036 **
000037 ** i.e. the WHERE clause expressions in the following statements all
000038 ** have an affinity:
000039 **
000040 ** CREATE TABLE t1(a);
000041 ** SELECT * FROM t1 WHERE a;
000042 ** SELECT a AS b FROM t1 WHERE b;
000043 ** SELECT * FROM t1 WHERE (select a from t1);
000044 */
000045 char sqlite3ExprAffinity(const Expr *pExpr){
000046 int op;
000047 op = pExpr->op;
000048 while( 1 /* exit-by-break */ ){
000049 if( op==TK_COLUMN || (op==TK_AGG_COLUMN && pExpr->y.pTab!=0) ){
000050 assert( ExprUseYTab(pExpr) );
000051 assert( pExpr->y.pTab!=0 );
000052 return sqlite3TableColumnAffinity(pExpr->y.pTab, pExpr->iColumn);
000053 }
000054 if( op==TK_SELECT ){
000055 assert( ExprUseXSelect(pExpr) );
000056 assert( pExpr->x.pSelect!=0 );
000057 assert( pExpr->x.pSelect->pEList!=0 );
000058 assert( pExpr->x.pSelect->pEList->a[0].pExpr!=0 );
000059 return sqlite3ExprAffinity(pExpr->x.pSelect->pEList->a[0].pExpr);
000060 }
000061 #ifndef SQLITE_OMIT_CAST
000062 if( op==TK_CAST ){
000063 assert( !ExprHasProperty(pExpr, EP_IntValue) );
000064 return sqlite3AffinityType(pExpr->u.zToken, 0);
000065 }
000066 #endif
000067 if( op==TK_SELECT_COLUMN ){
000068 assert( pExpr->pLeft!=0 && ExprUseXSelect(pExpr->pLeft) );
000069 assert( pExpr->iColumn < pExpr->iTable );
000070 assert( pExpr->iColumn >= 0 );
000071 assert( pExpr->iTable==pExpr->pLeft->x.pSelect->pEList->nExpr );
000072 return sqlite3ExprAffinity(
000073 pExpr->pLeft->x.pSelect->pEList->a[pExpr->iColumn].pExpr
000074 );
000075 }
000076 if( op==TK_VECTOR ){
000077 assert( ExprUseXList(pExpr) );
000078 return sqlite3ExprAffinity(pExpr->x.pList->a[0].pExpr);
000079 }
000080 if( ExprHasProperty(pExpr, EP_Skip|EP_IfNullRow) ){
000081 assert( pExpr->op==TK_COLLATE
000082 || pExpr->op==TK_IF_NULL_ROW
000083 || (pExpr->op==TK_REGISTER && pExpr->op2==TK_IF_NULL_ROW) );
000084 pExpr = pExpr->pLeft;
000085 op = pExpr->op;
000086 continue;
000087 }
000088 if( op!=TK_REGISTER || (op = pExpr->op2)==TK_REGISTER ) break;
000089 }
000090 return pExpr->affExpr;
000091 }
000092
000093 /*
000094 ** Make a guess at all the possible datatypes of the result that could
000095 ** be returned by an expression. Return a bitmask indicating the answer:
000096 **
000097 ** 0x01 Numeric
000098 ** 0x02 Text
000099 ** 0x04 Blob
000100 **
000101 ** If the expression must return NULL, then 0x00 is returned.
000102 */
000103 int sqlite3ExprDataType(const Expr *pExpr){
000104 while( pExpr ){
000105 switch( pExpr->op ){
000106 case TK_COLLATE:
000107 case TK_IF_NULL_ROW:
000108 case TK_UPLUS: {
000109 pExpr = pExpr->pLeft;
000110 break;
000111 }
000112 case TK_NULL: {
000113 pExpr = 0;
000114 break;
000115 }
000116 case TK_STRING: {
000117 return 0x02;
000118 }
000119 case TK_BLOB: {
000120 return 0x04;
000121 }
000122 case TK_CONCAT: {
000123 return 0x06;
000124 }
000125 case TK_VARIABLE:
000126 case TK_AGG_FUNCTION:
000127 case TK_FUNCTION: {
000128 return 0x07;
000129 }
000130 case TK_COLUMN:
000131 case TK_AGG_COLUMN:
000132 case TK_SELECT:
000133 case TK_CAST:
000134 case TK_SELECT_COLUMN:
000135 case TK_VECTOR: {
000136 int aff = sqlite3ExprAffinity(pExpr);
000137 if( aff>=SQLITE_AFF_NUMERIC ) return 0x05;
000138 if( aff==SQLITE_AFF_TEXT ) return 0x06;
000139 return 0x07;
000140 }
000141 case TK_CASE: {
000142 int res = 0;
000143 int ii;
000144 ExprList *pList = pExpr->x.pList;
000145 assert( ExprUseXList(pExpr) && pList!=0 );
000146 assert( pList->nExpr > 0);
000147 for(ii=1; ii<pList->nExpr; ii+=2){
000148 res |= sqlite3ExprDataType(pList->a[ii].pExpr);
000149 }
000150 if( pList->nExpr % 2 ){
000151 res |= sqlite3ExprDataType(pList->a[pList->nExpr-1].pExpr);
000152 }
000153 return res;
000154 }
000155 default: {
000156 return 0x01;
000157 }
000158 } /* End of switch(op) */
000159 } /* End of while(pExpr) */
000160 return 0x00;
000161 }
000162
000163 /*
000164 ** Set the collating sequence for expression pExpr to be the collating
000165 ** sequence named by pToken. Return a pointer to a new Expr node that
000166 ** implements the COLLATE operator.
000167 **
000168 ** If a memory allocation error occurs, that fact is recorded in pParse->db
000169 ** and the pExpr parameter is returned unchanged.
000170 */
000171 Expr *sqlite3ExprAddCollateToken(
000172 const Parse *pParse, /* Parsing context */
000173 Expr *pExpr, /* Add the "COLLATE" clause to this expression */
000174 const Token *pCollName, /* Name of collating sequence */
000175 int dequote /* True to dequote pCollName */
000176 ){
000177 if( pCollName->n>0 ){
000178 Expr *pNew = sqlite3ExprAlloc(pParse->db, TK_COLLATE, pCollName, dequote);
000179 if( pNew ){
000180 pNew->pLeft = pExpr;
000181 pNew->flags |= EP_Collate|EP_Skip;
000182 pExpr = pNew;
000183 }
000184 }
000185 return pExpr;
000186 }
000187 Expr *sqlite3ExprAddCollateString(
000188 const Parse *pParse, /* Parsing context */
000189 Expr *pExpr, /* Add the "COLLATE" clause to this expression */
000190 const char *zC /* The collating sequence name */
000191 ){
000192 Token s;
000193 assert( zC!=0 );
000194 sqlite3TokenInit(&s, (char*)zC);
000195 return sqlite3ExprAddCollateToken(pParse, pExpr, &s, 0);
000196 }
000197
000198 /*
000199 ** Skip over any TK_COLLATE operators.
000200 */
000201 Expr *sqlite3ExprSkipCollate(Expr *pExpr){
000202 while( pExpr && ExprHasProperty(pExpr, EP_Skip) ){
000203 assert( pExpr->op==TK_COLLATE );
000204 pExpr = pExpr->pLeft;
000205 }
000206 return pExpr;
000207 }
000208
000209 /*
000210 ** Skip over any TK_COLLATE operators and/or any unlikely()
000211 ** or likelihood() or likely() functions at the root of an
000212 ** expression.
000213 */
000214 Expr *sqlite3ExprSkipCollateAndLikely(Expr *pExpr){
000215 while( pExpr && ExprHasProperty(pExpr, EP_Skip|EP_Unlikely) ){
000216 if( ExprHasProperty(pExpr, EP_Unlikely) ){
000217 assert( ExprUseXList(pExpr) );
000218 assert( pExpr->x.pList->nExpr>0 );
000219 assert( pExpr->op==TK_FUNCTION );
000220 pExpr = pExpr->x.pList->a[0].pExpr;
000221 }else{
000222 assert( pExpr->op==TK_COLLATE );
000223 pExpr = pExpr->pLeft;
000224 }
000225 }
000226 return pExpr;
000227 }
000228
000229 /*
000230 ** Return the collation sequence for the expression pExpr. If
000231 ** there is no defined collating sequence, return NULL.
000232 **
000233 ** See also: sqlite3ExprNNCollSeq()
000234 **
000235 ** The sqlite3ExprNNCollSeq() works the same exact that it returns the
000236 ** default collation if pExpr has no defined collation.
000237 **
000238 ** The collating sequence might be determined by a COLLATE operator
000239 ** or by the presence of a column with a defined collating sequence.
000240 ** COLLATE operators take first precedence. Left operands take
000241 ** precedence over right operands.
000242 */
000243 CollSeq *sqlite3ExprCollSeq(Parse *pParse, const Expr *pExpr){
000244 sqlite3 *db = pParse->db;
000245 CollSeq *pColl = 0;
000246 const Expr *p = pExpr;
000247 while( p ){
000248 int op = p->op;
000249 if( op==TK_REGISTER ) op = p->op2;
000250 if( (op==TK_AGG_COLUMN && p->y.pTab!=0)
000251 || op==TK_COLUMN || op==TK_TRIGGER
000252 ){
000253 int j;
000254 assert( ExprUseYTab(p) );
000255 assert( p->y.pTab!=0 );
000256 if( (j = p->iColumn)>=0 ){
000257 const char *zColl = sqlite3ColumnColl(&p->y.pTab->aCol[j]);
000258 pColl = sqlite3FindCollSeq(db, ENC(db), zColl, 0);
000259 }
000260 break;
000261 }
000262 if( op==TK_CAST || op==TK_UPLUS ){
000263 p = p->pLeft;
000264 continue;
000265 }
000266 if( op==TK_VECTOR ){
000267 assert( ExprUseXList(p) );
000268 p = p->x.pList->a[0].pExpr;
000269 continue;
000270 }
000271 if( op==TK_COLLATE ){
000272 assert( !ExprHasProperty(p, EP_IntValue) );
000273 pColl = sqlite3GetCollSeq(pParse, ENC(db), 0, p->u.zToken);
000274 break;
000275 }
000276 if( p->flags & EP_Collate ){
000277 if( p->pLeft && (p->pLeft->flags & EP_Collate)!=0 ){
000278 p = p->pLeft;
000279 }else{
000280 Expr *pNext = p->pRight;
000281 /* The Expr.x union is never used at the same time as Expr.pRight */
000282 assert( !ExprUseXList(p) || p->x.pList==0 || p->pRight==0 );
000283 if( ExprUseXList(p) && p->x.pList!=0 && !db->mallocFailed ){
000284 int i;
000285 for(i=0; i<p->x.pList->nExpr; i++){
000286 if( ExprHasProperty(p->x.pList->a[i].pExpr, EP_Collate) ){
000287 pNext = p->x.pList->a[i].pExpr;
000288 break;
000289 }
000290 }
000291 }
000292 p = pNext;
000293 }
000294 }else{
000295 break;
000296 }
000297 }
000298 if( sqlite3CheckCollSeq(pParse, pColl) ){
000299 pColl = 0;
000300 }
000301 return pColl;
000302 }
000303
000304 /*
000305 ** Return the collation sequence for the expression pExpr. If
000306 ** there is no defined collating sequence, return a pointer to the
000307 ** default collation sequence.
000308 **
000309 ** See also: sqlite3ExprCollSeq()
000310 **
000311 ** The sqlite3ExprCollSeq() routine works the same except that it
000312 ** returns NULL if there is no defined collation.
000313 */
000314 CollSeq *sqlite3ExprNNCollSeq(Parse *pParse, const Expr *pExpr){
000315 CollSeq *p = sqlite3ExprCollSeq(pParse, pExpr);
000316 if( p==0 ) p = pParse->db->pDfltColl;
000317 assert( p!=0 );
000318 return p;
000319 }
000320
000321 /*
000322 ** Return TRUE if the two expressions have equivalent collating sequences.
000323 */
000324 int sqlite3ExprCollSeqMatch(Parse *pParse, const Expr *pE1, const Expr *pE2){
000325 CollSeq *pColl1 = sqlite3ExprNNCollSeq(pParse, pE1);
000326 CollSeq *pColl2 = sqlite3ExprNNCollSeq(pParse, pE2);
000327 return sqlite3StrICmp(pColl1->zName, pColl2->zName)==0;
000328 }
000329
000330 /*
000331 ** pExpr is an operand of a comparison operator. aff2 is the
000332 ** type affinity of the other operand. This routine returns the
000333 ** type affinity that should be used for the comparison operator.
000334 */
000335 char sqlite3CompareAffinity(const Expr *pExpr, char aff2){
000336 char aff1 = sqlite3ExprAffinity(pExpr);
000337 if( aff1>SQLITE_AFF_NONE && aff2>SQLITE_AFF_NONE ){
000338 /* Both sides of the comparison are columns. If one has numeric
000339 ** affinity, use that. Otherwise use no affinity.
000340 */
000341 if( sqlite3IsNumericAffinity(aff1) || sqlite3IsNumericAffinity(aff2) ){
000342 return SQLITE_AFF_NUMERIC;
000343 }else{
000344 return SQLITE_AFF_BLOB;
000345 }
000346 }else{
000347 /* One side is a column, the other is not. Use the columns affinity. */
000348 assert( aff1<=SQLITE_AFF_NONE || aff2<=SQLITE_AFF_NONE );
000349 return (aff1<=SQLITE_AFF_NONE ? aff2 : aff1) | SQLITE_AFF_NONE;
000350 }
000351 }
000352
000353 /*
000354 ** pExpr is a comparison operator. Return the type affinity that should
000355 ** be applied to both operands prior to doing the comparison.
000356 */
000357 static char comparisonAffinity(const Expr *pExpr){
000358 char aff;
000359 assert( pExpr->op==TK_EQ || pExpr->op==TK_IN || pExpr->op==TK_LT ||
000360 pExpr->op==TK_GT || pExpr->op==TK_GE || pExpr->op==TK_LE ||
000361 pExpr->op==TK_NE || pExpr->op==TK_IS || pExpr->op==TK_ISNOT );
000362 assert( pExpr->pLeft );
000363 aff = sqlite3ExprAffinity(pExpr->pLeft);
000364 if( pExpr->pRight ){
000365 aff = sqlite3CompareAffinity(pExpr->pRight, aff);
000366 }else if( ExprUseXSelect(pExpr) ){
000367 aff = sqlite3CompareAffinity(pExpr->x.pSelect->pEList->a[0].pExpr, aff);
000368 }else if( aff==0 ){
000369 aff = SQLITE_AFF_BLOB;
000370 }
000371 return aff;
000372 }
000373
000374 /*
000375 ** pExpr is a comparison expression, eg. '=', '<', IN(...) etc.
000376 ** idx_affinity is the affinity of an indexed column. Return true
000377 ** if the index with affinity idx_affinity may be used to implement
000378 ** the comparison in pExpr.
000379 */
000380 int sqlite3IndexAffinityOk(const Expr *pExpr, char idx_affinity){
000381 char aff = comparisonAffinity(pExpr);
000382 if( aff<SQLITE_AFF_TEXT ){
000383 return 1;
000384 }
000385 if( aff==SQLITE_AFF_TEXT ){
000386 return idx_affinity==SQLITE_AFF_TEXT;
000387 }
000388 return sqlite3IsNumericAffinity(idx_affinity);
000389 }
000390
000391 /*
000392 ** Return the P5 value that should be used for a binary comparison
000393 ** opcode (OP_Eq, OP_Ge etc.) used to compare pExpr1 and pExpr2.
000394 */
000395 static u8 binaryCompareP5(
000396 const Expr *pExpr1, /* Left operand */
000397 const Expr *pExpr2, /* Right operand */
000398 int jumpIfNull /* Extra flags added to P5 */
000399 ){
000400 u8 aff = (char)sqlite3ExprAffinity(pExpr2);
000401 aff = (u8)sqlite3CompareAffinity(pExpr1, aff) | (u8)jumpIfNull;
000402 return aff;
000403 }
000404
000405 /*
000406 ** Return a pointer to the collation sequence that should be used by
000407 ** a binary comparison operator comparing pLeft and pRight.
000408 **
000409 ** If the left hand expression has a collating sequence type, then it is
000410 ** used. Otherwise the collation sequence for the right hand expression
000411 ** is used, or the default (BINARY) if neither expression has a collating
000412 ** type.
000413 **
000414 ** Argument pRight (but not pLeft) may be a null pointer. In this case,
000415 ** it is not considered.
000416 */
000417 CollSeq *sqlite3BinaryCompareCollSeq(
000418 Parse *pParse,
000419 const Expr *pLeft,
000420 const Expr *pRight
000421 ){
000422 CollSeq *pColl;
000423 assert( pLeft );
000424 if( pLeft->flags & EP_Collate ){
000425 pColl = sqlite3ExprCollSeq(pParse, pLeft);
000426 }else if( pRight && (pRight->flags & EP_Collate)!=0 ){
000427 pColl = sqlite3ExprCollSeq(pParse, pRight);
000428 }else{
000429 pColl = sqlite3ExprCollSeq(pParse, pLeft);
000430 if( !pColl ){
000431 pColl = sqlite3ExprCollSeq(pParse, pRight);
000432 }
000433 }
000434 return pColl;
000435 }
000436
000437 /* Expression p is a comparison operator. Return a collation sequence
000438 ** appropriate for the comparison operator.
000439 **
000440 ** This is normally just a wrapper around sqlite3BinaryCompareCollSeq().
000441 ** However, if the OP_Commuted flag is set, then the order of the operands
000442 ** is reversed in the sqlite3BinaryCompareCollSeq() call so that the
000443 ** correct collating sequence is found.
000444 */
000445 CollSeq *sqlite3ExprCompareCollSeq(Parse *pParse, const Expr *p){
000446 if( ExprHasProperty(p, EP_Commuted) ){
000447 return sqlite3BinaryCompareCollSeq(pParse, p->pRight, p->pLeft);
000448 }else{
000449 return sqlite3BinaryCompareCollSeq(pParse, p->pLeft, p->pRight);
000450 }
000451 }
000452
000453 /*
000454 ** Generate code for a comparison operator.
000455 */
000456 static int codeCompare(
000457 Parse *pParse, /* The parsing (and code generating) context */
000458 Expr *pLeft, /* The left operand */
000459 Expr *pRight, /* The right operand */
000460 int opcode, /* The comparison opcode */
000461 int in1, int in2, /* Register holding operands */
000462 int dest, /* Jump here if true. */
000463 int jumpIfNull, /* If true, jump if either operand is NULL */
000464 int isCommuted /* The comparison has been commuted */
000465 ){
000466 int p5;
000467 int addr;
000468 CollSeq *p4;
000469
000470 if( pParse->nErr ) return 0;
000471 if( isCommuted ){
000472 p4 = sqlite3BinaryCompareCollSeq(pParse, pRight, pLeft);
000473 }else{
000474 p4 = sqlite3BinaryCompareCollSeq(pParse, pLeft, pRight);
000475 }
000476 p5 = binaryCompareP5(pLeft, pRight, jumpIfNull);
000477 addr = sqlite3VdbeAddOp4(pParse->pVdbe, opcode, in2, dest, in1,
000478 (void*)p4, P4_COLLSEQ);
000479 sqlite3VdbeChangeP5(pParse->pVdbe, (u8)p5);
000480 return addr;
000481 }
000482
000483 /*
000484 ** Return true if expression pExpr is a vector, or false otherwise.
000485 **
000486 ** A vector is defined as any expression that results in two or more
000487 ** columns of result. Every TK_VECTOR node is an vector because the
000488 ** parser will not generate a TK_VECTOR with fewer than two entries.
000489 ** But a TK_SELECT might be either a vector or a scalar. It is only
000490 ** considered a vector if it has two or more result columns.
000491 */
000492 int sqlite3ExprIsVector(const Expr *pExpr){
000493 return sqlite3ExprVectorSize(pExpr)>1;
000494 }
000495
000496 /*
000497 ** If the expression passed as the only argument is of type TK_VECTOR
000498 ** return the number of expressions in the vector. Or, if the expression
000499 ** is a sub-select, return the number of columns in the sub-select. For
000500 ** any other type of expression, return 1.
000501 */
000502 int sqlite3ExprVectorSize(const Expr *pExpr){
000503 u8 op = pExpr->op;
000504 if( op==TK_REGISTER ) op = pExpr->op2;
000505 if( op==TK_VECTOR ){
000506 assert( ExprUseXList(pExpr) );
000507 return pExpr->x.pList->nExpr;
000508 }else if( op==TK_SELECT ){
000509 assert( ExprUseXSelect(pExpr) );
000510 return pExpr->x.pSelect->pEList->nExpr;
000511 }else{
000512 return 1;
000513 }
000514 }
000515
000516 /*
000517 ** Return a pointer to a subexpression of pVector that is the i-th
000518 ** column of the vector (numbered starting with 0). The caller must
000519 ** ensure that i is within range.
000520 **
000521 ** If pVector is really a scalar (and "scalar" here includes subqueries
000522 ** that return a single column!) then return pVector unmodified.
000523 **
000524 ** pVector retains ownership of the returned subexpression.
000525 **
000526 ** If the vector is a (SELECT ...) then the expression returned is
000527 ** just the expression for the i-th term of the result set, and may
000528 ** not be ready for evaluation because the table cursor has not yet
000529 ** been positioned.
000530 */
000531 Expr *sqlite3VectorFieldSubexpr(Expr *pVector, int i){
000532 assert( i<sqlite3ExprVectorSize(pVector) || pVector->op==TK_ERROR );
000533 if( sqlite3ExprIsVector(pVector) ){
000534 assert( pVector->op2==0 || pVector->op==TK_REGISTER );
000535 if( pVector->op==TK_SELECT || pVector->op2==TK_SELECT ){
000536 assert( ExprUseXSelect(pVector) );
000537 return pVector->x.pSelect->pEList->a[i].pExpr;
000538 }else{
000539 assert( ExprUseXList(pVector) );
000540 return pVector->x.pList->a[i].pExpr;
000541 }
000542 }
000543 return pVector;
000544 }
000545
000546 /*
000547 ** Compute and return a new Expr object which when passed to
000548 ** sqlite3ExprCode() will generate all necessary code to compute
000549 ** the iField-th column of the vector expression pVector.
000550 **
000551 ** It is ok for pVector to be a scalar (as long as iField==0).
000552 ** In that case, this routine works like sqlite3ExprDup().
000553 **
000554 ** The caller owns the returned Expr object and is responsible for
000555 ** ensuring that the returned value eventually gets freed.
000556 **
000557 ** The caller retains ownership of pVector. If pVector is a TK_SELECT,
000558 ** then the returned object will reference pVector and so pVector must remain
000559 ** valid for the life of the returned object. If pVector is a TK_VECTOR
000560 ** or a scalar expression, then it can be deleted as soon as this routine
000561 ** returns.
000562 **
000563 ** A trick to cause a TK_SELECT pVector to be deleted together with
000564 ** the returned Expr object is to attach the pVector to the pRight field
000565 ** of the returned TK_SELECT_COLUMN Expr object.
000566 */
000567 Expr *sqlite3ExprForVectorField(
000568 Parse *pParse, /* Parsing context */
000569 Expr *pVector, /* The vector. List of expressions or a sub-SELECT */
000570 int iField, /* Which column of the vector to return */
000571 int nField /* Total number of columns in the vector */
000572 ){
000573 Expr *pRet;
000574 if( pVector->op==TK_SELECT ){
000575 assert( ExprUseXSelect(pVector) );
000576 /* The TK_SELECT_COLUMN Expr node:
000577 **
000578 ** pLeft: pVector containing TK_SELECT. Not deleted.
000579 ** pRight: not used. But recursively deleted.
000580 ** iColumn: Index of a column in pVector
000581 ** iTable: 0 or the number of columns on the LHS of an assignment
000582 ** pLeft->iTable: First in an array of register holding result, or 0
000583 ** if the result is not yet computed.
000584 **
000585 ** sqlite3ExprDelete() specifically skips the recursive delete of
000586 ** pLeft on TK_SELECT_COLUMN nodes. But pRight is followed, so pVector
000587 ** can be attached to pRight to cause this node to take ownership of
000588 ** pVector. Typically there will be multiple TK_SELECT_COLUMN nodes
000589 ** with the same pLeft pointer to the pVector, but only one of them
000590 ** will own the pVector.
000591 */
000592 pRet = sqlite3PExpr(pParse, TK_SELECT_COLUMN, 0, 0);
000593 if( pRet ){
000594 pRet->iTable = nField;
000595 pRet->iColumn = iField;
000596 pRet->pLeft = pVector;
000597 }
000598 }else{
000599 if( pVector->op==TK_VECTOR ){
000600 Expr **ppVector;
000601 assert( ExprUseXList(pVector) );
000602 ppVector = &pVector->x.pList->a[iField].pExpr;
000603 pVector = *ppVector;
000604 if( IN_RENAME_OBJECT ){
000605 /* This must be a vector UPDATE inside a trigger */
000606 *ppVector = 0;
000607 return pVector;
000608 }
000609 }
000610 pRet = sqlite3ExprDup(pParse->db, pVector, 0);
000611 }
000612 return pRet;
000613 }
000614
000615 /*
000616 ** If expression pExpr is of type TK_SELECT, generate code to evaluate
000617 ** it. Return the register in which the result is stored (or, if the
000618 ** sub-select returns more than one column, the first in an array
000619 ** of registers in which the result is stored).
000620 **
000621 ** If pExpr is not a TK_SELECT expression, return 0.
000622 */
000623 static int exprCodeSubselect(Parse *pParse, Expr *pExpr){
000624 int reg = 0;
000625 #ifndef SQLITE_OMIT_SUBQUERY
000626 if( pExpr->op==TK_SELECT ){
000627 reg = sqlite3CodeSubselect(pParse, pExpr);
000628 }
000629 #endif
000630 return reg;
000631 }
000632
000633 /*
000634 ** Argument pVector points to a vector expression - either a TK_VECTOR
000635 ** or TK_SELECT that returns more than one column. This function returns
000636 ** the register number of a register that contains the value of
000637 ** element iField of the vector.
000638 **
000639 ** If pVector is a TK_SELECT expression, then code for it must have
000640 ** already been generated using the exprCodeSubselect() routine. In this
000641 ** case parameter regSelect should be the first in an array of registers
000642 ** containing the results of the sub-select.
000643 **
000644 ** If pVector is of type TK_VECTOR, then code for the requested field
000645 ** is generated. In this case (*pRegFree) may be set to the number of
000646 ** a temporary register to be freed by the caller before returning.
000647 **
000648 ** Before returning, output parameter (*ppExpr) is set to point to the
000649 ** Expr object corresponding to element iElem of the vector.
000650 */
000651 static int exprVectorRegister(
000652 Parse *pParse, /* Parse context */
000653 Expr *pVector, /* Vector to extract element from */
000654 int iField, /* Field to extract from pVector */
000655 int regSelect, /* First in array of registers */
000656 Expr **ppExpr, /* OUT: Expression element */
000657 int *pRegFree /* OUT: Temp register to free */
000658 ){
000659 u8 op = pVector->op;
000660 assert( op==TK_VECTOR || op==TK_REGISTER || op==TK_SELECT || op==TK_ERROR );
000661 if( op==TK_REGISTER ){
000662 *ppExpr = sqlite3VectorFieldSubexpr(pVector, iField);
000663 return pVector->iTable+iField;
000664 }
000665 if( op==TK_SELECT ){
000666 assert( ExprUseXSelect(pVector) );
000667 *ppExpr = pVector->x.pSelect->pEList->a[iField].pExpr;
000668 return regSelect+iField;
000669 }
000670 if( op==TK_VECTOR ){
000671 assert( ExprUseXList(pVector) );
000672 *ppExpr = pVector->x.pList->a[iField].pExpr;
000673 return sqlite3ExprCodeTemp(pParse, *ppExpr, pRegFree);
000674 }
000675 return 0;
000676 }
000677
000678 /*
000679 ** Expression pExpr is a comparison between two vector values. Compute
000680 ** the result of the comparison (1, 0, or NULL) and write that
000681 ** result into register dest.
000682 **
000683 ** The caller must satisfy the following preconditions:
000684 **
000685 ** if pExpr->op==TK_IS: op==TK_EQ and p5==SQLITE_NULLEQ
000686 ** if pExpr->op==TK_ISNOT: op==TK_NE and p5==SQLITE_NULLEQ
000687 ** otherwise: op==pExpr->op and p5==0
000688 */
000689 static void codeVectorCompare(
000690 Parse *pParse, /* Code generator context */
000691 Expr *pExpr, /* The comparison operation */
000692 int dest, /* Write results into this register */
000693 u8 op, /* Comparison operator */
000694 u8 p5 /* SQLITE_NULLEQ or zero */
000695 ){
000696 Vdbe *v = pParse->pVdbe;
000697 Expr *pLeft = pExpr->pLeft;
000698 Expr *pRight = pExpr->pRight;
000699 int nLeft = sqlite3ExprVectorSize(pLeft);
000700 int i;
000701 int regLeft = 0;
000702 int regRight = 0;
000703 u8 opx = op;
000704 int addrCmp = 0;
000705 int addrDone = sqlite3VdbeMakeLabel(pParse);
000706 int isCommuted = ExprHasProperty(pExpr,EP_Commuted);
000707
000708 assert( !ExprHasVVAProperty(pExpr,EP_Immutable) );
000709 if( pParse->nErr ) return;
000710 if( nLeft!=sqlite3ExprVectorSize(pRight) ){
000711 sqlite3ErrorMsg(pParse, "row value misused");
000712 return;
000713 }
000714 assert( pExpr->op==TK_EQ || pExpr->op==TK_NE
000715 || pExpr->op==TK_IS || pExpr->op==TK_ISNOT
000716 || pExpr->op==TK_LT || pExpr->op==TK_GT
000717 || pExpr->op==TK_LE || pExpr->op==TK_GE
000718 );
000719 assert( pExpr->op==op || (pExpr->op==TK_IS && op==TK_EQ)
000720 || (pExpr->op==TK_ISNOT && op==TK_NE) );
000721 assert( p5==0 || pExpr->op!=op );
000722 assert( p5==SQLITE_NULLEQ || pExpr->op==op );
000723
000724 if( op==TK_LE ) opx = TK_LT;
000725 if( op==TK_GE ) opx = TK_GT;
000726 if( op==TK_NE ) opx = TK_EQ;
000727
000728 regLeft = exprCodeSubselect(pParse, pLeft);
000729 regRight = exprCodeSubselect(pParse, pRight);
000730
000731 sqlite3VdbeAddOp2(v, OP_Integer, 1, dest);
000732 for(i=0; 1 /*Loop exits by "break"*/; i++){
000733 int regFree1 = 0, regFree2 = 0;
000734 Expr *pL = 0, *pR = 0;
000735 int r1, r2;
000736 assert( i>=0 && i<nLeft );
000737 if( addrCmp ) sqlite3VdbeJumpHere(v, addrCmp);
000738 r1 = exprVectorRegister(pParse, pLeft, i, regLeft, &pL, ®Free1);
000739 r2 = exprVectorRegister(pParse, pRight, i, regRight, &pR, ®Free2);
000740 addrCmp = sqlite3VdbeCurrentAddr(v);
000741 codeCompare(pParse, pL, pR, opx, r1, r2, addrDone, p5, isCommuted);
000742 testcase(op==OP_Lt); VdbeCoverageIf(v,op==OP_Lt);
000743 testcase(op==OP_Le); VdbeCoverageIf(v,op==OP_Le);
000744 testcase(op==OP_Gt); VdbeCoverageIf(v,op==OP_Gt);
000745 testcase(op==OP_Ge); VdbeCoverageIf(v,op==OP_Ge);
000746 testcase(op==OP_Eq); VdbeCoverageIf(v,op==OP_Eq);
000747 testcase(op==OP_Ne); VdbeCoverageIf(v,op==OP_Ne);
000748 sqlite3ReleaseTempReg(pParse, regFree1);
000749 sqlite3ReleaseTempReg(pParse, regFree2);
000750 if( (opx==TK_LT || opx==TK_GT) && i<nLeft-1 ){
000751 addrCmp = sqlite3VdbeAddOp0(v, OP_ElseEq);
000752 testcase(opx==TK_LT); VdbeCoverageIf(v,opx==TK_LT);
000753 testcase(opx==TK_GT); VdbeCoverageIf(v,opx==TK_GT);
000754 }
000755 if( p5==SQLITE_NULLEQ ){
000756 sqlite3VdbeAddOp2(v, OP_Integer, 0, dest);
000757 }else{
000758 sqlite3VdbeAddOp3(v, OP_ZeroOrNull, r1, dest, r2);
000759 }
000760 if( i==nLeft-1 ){
000761 break;
000762 }
000763 if( opx==TK_EQ ){
000764 sqlite3VdbeAddOp2(v, OP_NotNull, dest, addrDone); VdbeCoverage(v);
000765 }else{
000766 assert( op==TK_LT || op==TK_GT || op==TK_LE || op==TK_GE );
000767 sqlite3VdbeAddOp2(v, OP_Goto, 0, addrDone);
000768 if( i==nLeft-2 ) opx = op;
000769 }
000770 }
000771 sqlite3VdbeJumpHere(v, addrCmp);
000772 sqlite3VdbeResolveLabel(v, addrDone);
000773 if( op==TK_NE ){
000774 sqlite3VdbeAddOp2(v, OP_Not, dest, dest);
000775 }
000776 }
000777
000778 #if SQLITE_MAX_EXPR_DEPTH>0
000779 /*
000780 ** Check that argument nHeight is less than or equal to the maximum
000781 ** expression depth allowed. If it is not, leave an error message in
000782 ** pParse.
000783 */
000784 int sqlite3ExprCheckHeight(Parse *pParse, int nHeight){
000785 int rc = SQLITE_OK;
000786 int mxHeight = pParse->db->aLimit[SQLITE_LIMIT_EXPR_DEPTH];
000787 if( nHeight>mxHeight ){
000788 sqlite3ErrorMsg(pParse,
000789 "Expression tree is too large (maximum depth %d)", mxHeight
000790 );
000791 rc = SQLITE_ERROR;
000792 }
000793 return rc;
000794 }
000795
000796 /* The following three functions, heightOfExpr(), heightOfExprList()
000797 ** and heightOfSelect(), are used to determine the maximum height
000798 ** of any expression tree referenced by the structure passed as the
000799 ** first argument.
000800 **
000801 ** If this maximum height is greater than the current value pointed
000802 ** to by pnHeight, the second parameter, then set *pnHeight to that
000803 ** value.
000804 */
000805 static void heightOfExpr(const Expr *p, int *pnHeight){
000806 if( p ){
000807 if( p->nHeight>*pnHeight ){
000808 *pnHeight = p->nHeight;
000809 }
000810 }
000811 }
000812 static void heightOfExprList(const ExprList *p, int *pnHeight){
000813 if( p ){
000814 int i;
000815 for(i=0; i<p->nExpr; i++){
000816 heightOfExpr(p->a[i].pExpr, pnHeight);
000817 }
000818 }
000819 }
000820 static void heightOfSelect(const Select *pSelect, int *pnHeight){
000821 const Select *p;
000822 for(p=pSelect; p; p=p->pPrior){
000823 heightOfExpr(p->pWhere, pnHeight);
000824 heightOfExpr(p->pHaving, pnHeight);
000825 heightOfExpr(p->pLimit, pnHeight);
000826 heightOfExprList(p->pEList, pnHeight);
000827 heightOfExprList(p->pGroupBy, pnHeight);
000828 heightOfExprList(p->pOrderBy, pnHeight);
000829 }
000830 }
000831
000832 /*
000833 ** Set the Expr.nHeight variable in the structure passed as an
000834 ** argument. An expression with no children, Expr.pList or
000835 ** Expr.pSelect member has a height of 1. Any other expression
000836 ** has a height equal to the maximum height of any other
000837 ** referenced Expr plus one.
000838 **
000839 ** Also propagate EP_Propagate flags up from Expr.x.pList to Expr.flags,
000840 ** if appropriate.
000841 */
000842 static void exprSetHeight(Expr *p){
000843 int nHeight = p->pLeft ? p->pLeft->nHeight : 0;
000844 if( NEVER(p->pRight) && p->pRight->nHeight>nHeight ){
000845 nHeight = p->pRight->nHeight;
000846 }
000847 if( ExprUseXSelect(p) ){
000848 heightOfSelect(p->x.pSelect, &nHeight);
000849 }else if( p->x.pList ){
000850 heightOfExprList(p->x.pList, &nHeight);
000851 p->flags |= EP_Propagate & sqlite3ExprListFlags(p->x.pList);
000852 }
000853 p->nHeight = nHeight + 1;
000854 }
000855
000856 /*
000857 ** Set the Expr.nHeight variable using the exprSetHeight() function. If
000858 ** the height is greater than the maximum allowed expression depth,
000859 ** leave an error in pParse.
000860 **
000861 ** Also propagate all EP_Propagate flags from the Expr.x.pList into
000862 ** Expr.flags.
000863 */
000864 void sqlite3ExprSetHeightAndFlags(Parse *pParse, Expr *p){
000865 if( pParse->nErr ) return;
000866 exprSetHeight(p);
000867 sqlite3ExprCheckHeight(pParse, p->nHeight);
000868 }
000869
000870 /*
000871 ** Return the maximum height of any expression tree referenced
000872 ** by the select statement passed as an argument.
000873 */
000874 int sqlite3SelectExprHeight(const Select *p){
000875 int nHeight = 0;
000876 heightOfSelect(p, &nHeight);
000877 return nHeight;
000878 }
000879 #else /* ABOVE: Height enforcement enabled. BELOW: Height enforcement off */
000880 /*
000881 ** Propagate all EP_Propagate flags from the Expr.x.pList into
000882 ** Expr.flags.
000883 */
000884 void sqlite3ExprSetHeightAndFlags(Parse *pParse, Expr *p){
000885 if( pParse->nErr ) return;
000886 if( p && ExprUseXList(p) && p->x.pList ){
000887 p->flags |= EP_Propagate & sqlite3ExprListFlags(p->x.pList);
000888 }
000889 }
000890 #define exprSetHeight(y)
000891 #endif /* SQLITE_MAX_EXPR_DEPTH>0 */
000892
000893 /*
000894 ** Set the error offset for an Expr node, if possible.
000895 */
000896 void sqlite3ExprSetErrorOffset(Expr *pExpr, int iOfst){
000897 if( pExpr==0 ) return;
000898 if( NEVER(ExprUseWJoin(pExpr)) ) return;
000899 pExpr->w.iOfst = iOfst;
000900 }
000901
000902 /*
000903 ** This routine is the core allocator for Expr nodes.
000904 **
000905 ** Construct a new expression node and return a pointer to it. Memory
000906 ** for this node and for the pToken argument is a single allocation
000907 ** obtained from sqlite3DbMalloc(). The calling function
000908 ** is responsible for making sure the node eventually gets freed.
000909 **
000910 ** If dequote is true, then the token (if it exists) is dequoted.
000911 ** If dequote is false, no dequoting is performed. The deQuote
000912 ** parameter is ignored if pToken is NULL or if the token does not
000913 ** appear to be quoted. If the quotes were of the form "..." (double-quotes)
000914 ** then the EP_DblQuoted flag is set on the expression node.
000915 **
000916 ** Special case: If op==TK_INTEGER and pToken points to a string that
000917 ** can be translated into a 32-bit integer, then the token is not
000918 ** stored in u.zToken. Instead, the integer values is written
000919 ** into u.iValue and the EP_IntValue flag is set. No extra storage
000920 ** is allocated to hold the integer text and the dequote flag is ignored.
000921 */
000922 Expr *sqlite3ExprAlloc(
000923 sqlite3 *db, /* Handle for sqlite3DbMallocRawNN() */
000924 int op, /* Expression opcode */
000925 const Token *pToken, /* Token argument. Might be NULL */
000926 int dequote /* True to dequote */
000927 ){
000928 Expr *pNew;
000929 int nExtra = 0;
000930 int iValue = 0;
000931
000932 assert( db!=0 );
000933 if( pToken ){
000934 if( op!=TK_INTEGER || pToken->z==0
000935 || sqlite3GetInt32(pToken->z, &iValue)==0 ){
000936 nExtra = pToken->n+1;
000937 assert( iValue>=0 );
000938 }
000939 }
000940 pNew = sqlite3DbMallocRawNN(db, sizeof(Expr)+nExtra);
000941 if( pNew ){
000942 memset(pNew, 0, sizeof(Expr));
000943 pNew->op = (u8)op;
000944 pNew->iAgg = -1;
000945 if( pToken ){
000946 if( nExtra==0 ){
000947 pNew->flags |= EP_IntValue|EP_Leaf|(iValue?EP_IsTrue:EP_IsFalse);
000948 pNew->u.iValue = iValue;
000949 }else{
000950 pNew->u.zToken = (char*)&pNew[1];
000951 assert( pToken->z!=0 || pToken->n==0 );
000952 if( pToken->n ) memcpy(pNew->u.zToken, pToken->z, pToken->n);
000953 pNew->u.zToken[pToken->n] = 0;
000954 if( dequote && sqlite3Isquote(pNew->u.zToken[0]) ){
000955 sqlite3DequoteExpr(pNew);
000956 }
000957 }
000958 }
000959 #if SQLITE_MAX_EXPR_DEPTH>0
000960 pNew->nHeight = 1;
000961 #endif
000962 }
000963 return pNew;
000964 }
000965
000966 /*
000967 ** Allocate a new expression node from a zero-terminated token that has
000968 ** already been dequoted.
000969 */
000970 Expr *sqlite3Expr(
000971 sqlite3 *db, /* Handle for sqlite3DbMallocZero() (may be null) */
000972 int op, /* Expression opcode */
000973 const char *zToken /* Token argument. Might be NULL */
000974 ){
000975 Token x;
000976 x.z = zToken;
000977 x.n = sqlite3Strlen30(zToken);
000978 return sqlite3ExprAlloc(db, op, &x, 0);
000979 }
000980
000981 /*
000982 ** Attach subtrees pLeft and pRight to the Expr node pRoot.
000983 **
000984 ** If pRoot==NULL that means that a memory allocation error has occurred.
000985 ** In that case, delete the subtrees pLeft and pRight.
000986 */
000987 void sqlite3ExprAttachSubtrees(
000988 sqlite3 *db,
000989 Expr *pRoot,
000990 Expr *pLeft,
000991 Expr *pRight
000992 ){
000993 if( pRoot==0 ){
000994 assert( db->mallocFailed );
000995 sqlite3ExprDelete(db, pLeft);
000996 sqlite3ExprDelete(db, pRight);
000997 }else{
000998 assert( ExprUseXList(pRoot) );
000999 assert( pRoot->x.pSelect==0 );
001000 if( pRight ){
001001 pRoot->pRight = pRight;
001002 pRoot->flags |= EP_Propagate & pRight->flags;
001003 #if SQLITE_MAX_EXPR_DEPTH>0
001004 pRoot->nHeight = pRight->nHeight+1;
001005 }else{
001006 pRoot->nHeight = 1;
001007 #endif
001008 }
001009 if( pLeft ){
001010 pRoot->pLeft = pLeft;
001011 pRoot->flags |= EP_Propagate & pLeft->flags;
001012 #if SQLITE_MAX_EXPR_DEPTH>0
001013 if( pLeft->nHeight>=pRoot->nHeight ){
001014 pRoot->nHeight = pLeft->nHeight+1;
001015 }
001016 #endif
001017 }
001018 }
001019 }
001020
001021 /*
001022 ** Allocate an Expr node which joins as many as two subtrees.
001023 **
001024 ** One or both of the subtrees can be NULL. Return a pointer to the new
001025 ** Expr node. Or, if an OOM error occurs, set pParse->db->mallocFailed,
001026 ** free the subtrees and return NULL.
001027 */
001028 Expr *sqlite3PExpr(
001029 Parse *pParse, /* Parsing context */
001030 int op, /* Expression opcode */
001031 Expr *pLeft, /* Left operand */
001032 Expr *pRight /* Right operand */
001033 ){
001034 Expr *p;
001035 p = sqlite3DbMallocRawNN(pParse->db, sizeof(Expr));
001036 if( p ){
001037 memset(p, 0, sizeof(Expr));
001038 p->op = op & 0xff;
001039 p->iAgg = -1;
001040 sqlite3ExprAttachSubtrees(pParse->db, p, pLeft, pRight);
001041 sqlite3ExprCheckHeight(pParse, p->nHeight);
001042 }else{
001043 sqlite3ExprDelete(pParse->db, pLeft);
001044 sqlite3ExprDelete(pParse->db, pRight);
001045 }
001046 return p;
001047 }
001048
001049 /*
001050 ** Add pSelect to the Expr.x.pSelect field. Or, if pExpr is NULL (due
001051 ** do a memory allocation failure) then delete the pSelect object.
001052 */
001053 void sqlite3PExprAddSelect(Parse *pParse, Expr *pExpr, Select *pSelect){
001054 if( pExpr ){
001055 pExpr->x.pSelect = pSelect;
001056 ExprSetProperty(pExpr, EP_xIsSelect|EP_Subquery);
001057 sqlite3ExprSetHeightAndFlags(pParse, pExpr);
001058 }else{
001059 assert( pParse->db->mallocFailed );
001060 sqlite3SelectDelete(pParse->db, pSelect);
001061 }
001062 }
001063
001064 /*
001065 ** Expression list pEList is a list of vector values. This function
001066 ** converts the contents of pEList to a VALUES(...) Select statement
001067 ** returning 1 row for each element of the list. For example, the
001068 ** expression list:
001069 **
001070 ** ( (1,2), (3,4) (5,6) )
001071 **
001072 ** is translated to the equivalent of:
001073 **
001074 ** VALUES(1,2), (3,4), (5,6)
001075 **
001076 ** Each of the vector values in pEList must contain exactly nElem terms.
001077 ** If a list element that is not a vector or does not contain nElem terms,
001078 ** an error message is left in pParse.
001079 **
001080 ** This is used as part of processing IN(...) expressions with a list
001081 ** of vectors on the RHS. e.g. "... IN ((1,2), (3,4), (5,6))".
001082 */
001083 Select *sqlite3ExprListToValues(Parse *pParse, int nElem, ExprList *pEList){
001084 int ii;
001085 Select *pRet = 0;
001086 assert( nElem>1 );
001087 for(ii=0; ii<pEList->nExpr; ii++){
001088 Select *pSel;
001089 Expr *pExpr = pEList->a[ii].pExpr;
001090 int nExprElem;
001091 if( pExpr->op==TK_VECTOR ){
001092 assert( ExprUseXList(pExpr) );
001093 nExprElem = pExpr->x.pList->nExpr;
001094 }else{
001095 nExprElem = 1;
001096 }
001097 if( nExprElem!=nElem ){
001098 sqlite3ErrorMsg(pParse, "IN(...) element has %d term%s - expected %d",
001099 nExprElem, nExprElem>1?"s":"", nElem
001100 );
001101 break;
001102 }
001103 assert( ExprUseXList(pExpr) );
001104 pSel = sqlite3SelectNew(pParse, pExpr->x.pList, 0, 0, 0, 0, 0, SF_Values,0);
001105 pExpr->x.pList = 0;
001106 if( pSel ){
001107 if( pRet ){
001108 pSel->op = TK_ALL;
001109 pSel->pPrior = pRet;
001110 }
001111 pRet = pSel;
001112 }
001113 }
001114
001115 if( pRet && pRet->pPrior ){
001116 pRet->selFlags |= SF_MultiValue;
001117 }
001118 sqlite3ExprListDelete(pParse->db, pEList);
001119 return pRet;
001120 }
001121
001122 /*
001123 ** Join two expressions using an AND operator. If either expression is
001124 ** NULL, then just return the other expression.
001125 **
001126 ** If one side or the other of the AND is known to be false, and neither side
001127 ** is part of an ON clause, then instead of returning an AND expression,
001128 ** just return a constant expression with a value of false.
001129 */
001130 Expr *sqlite3ExprAnd(Parse *pParse, Expr *pLeft, Expr *pRight){
001131 sqlite3 *db = pParse->db;
001132 if( pLeft==0 ){
001133 return pRight;
001134 }else if( pRight==0 ){
001135 return pLeft;
001136 }else{
001137 u32 f = pLeft->flags | pRight->flags;
001138 if( (f&(EP_OuterON|EP_InnerON|EP_IsFalse))==EP_IsFalse
001139 && !IN_RENAME_OBJECT
001140 ){
001141 sqlite3ExprDeferredDelete(pParse, pLeft);
001142 sqlite3ExprDeferredDelete(pParse, pRight);
001143 return sqlite3Expr(db, TK_INTEGER, "0");
001144 }else{
001145 return sqlite3PExpr(pParse, TK_AND, pLeft, pRight);
001146 }
001147 }
001148 }
001149
001150 /*
001151 ** Construct a new expression node for a function with multiple
001152 ** arguments.
001153 */
001154 Expr *sqlite3ExprFunction(
001155 Parse *pParse, /* Parsing context */
001156 ExprList *pList, /* Argument list */
001157 const Token *pToken, /* Name of the function */
001158 int eDistinct /* SF_Distinct or SF_ALL or 0 */
001159 ){
001160 Expr *pNew;
001161 sqlite3 *db = pParse->db;
001162 assert( pToken );
001163 pNew = sqlite3ExprAlloc(db, TK_FUNCTION, pToken, 1);
001164 if( pNew==0 ){
001165 sqlite3ExprListDelete(db, pList); /* Avoid memory leak when malloc fails */
001166 return 0;
001167 }
001168 assert( !ExprHasProperty(pNew, EP_InnerON|EP_OuterON) );
001169 pNew->w.iOfst = (int)(pToken->z - pParse->zTail);
001170 if( pList
001171 && pList->nExpr > pParse->db->aLimit[SQLITE_LIMIT_FUNCTION_ARG]
001172 && !pParse->nested
001173 ){
001174 sqlite3ErrorMsg(pParse, "too many arguments on function %T", pToken);
001175 }
001176 pNew->x.pList = pList;
001177 ExprSetProperty(pNew, EP_HasFunc);
001178 assert( ExprUseXList(pNew) );
001179 sqlite3ExprSetHeightAndFlags(pParse, pNew);
001180 if( eDistinct==SF_Distinct ) ExprSetProperty(pNew, EP_Distinct);
001181 return pNew;
001182 }
001183
001184 /*
001185 ** Check to see if a function is usable according to current access
001186 ** rules:
001187 **
001188 ** SQLITE_FUNC_DIRECT - Only usable from top-level SQL
001189 **
001190 ** SQLITE_FUNC_UNSAFE - Usable if TRUSTED_SCHEMA or from
001191 ** top-level SQL
001192 **
001193 ** If the function is not usable, create an error.
001194 */
001195 void sqlite3ExprFunctionUsable(
001196 Parse *pParse, /* Parsing and code generating context */
001197 const Expr *pExpr, /* The function invocation */
001198 const FuncDef *pDef /* The function being invoked */
001199 ){
001200 assert( !IN_RENAME_OBJECT );
001201 assert( (pDef->funcFlags & (SQLITE_FUNC_DIRECT|SQLITE_FUNC_UNSAFE))!=0 );
001202 if( ExprHasProperty(pExpr, EP_FromDDL) ){
001203 if( (pDef->funcFlags & SQLITE_FUNC_DIRECT)!=0
001204 || (pParse->db->flags & SQLITE_TrustedSchema)==0
001205 ){
001206 /* Functions prohibited in triggers and views if:
001207 ** (1) tagged with SQLITE_DIRECTONLY
001208 ** (2) not tagged with SQLITE_INNOCUOUS (which means it
001209 ** is tagged with SQLITE_FUNC_UNSAFE) and
001210 ** SQLITE_DBCONFIG_TRUSTED_SCHEMA is off (meaning
001211 ** that the schema is possibly tainted).
001212 */
001213 sqlite3ErrorMsg(pParse, "unsafe use of %#T()", pExpr);
001214 }
001215 }
001216 }
001217
001218 /*
001219 ** Assign a variable number to an expression that encodes a wildcard
001220 ** in the original SQL statement.
001221 **
001222 ** Wildcards consisting of a single "?" are assigned the next sequential
001223 ** variable number.
001224 **
001225 ** Wildcards of the form "?nnn" are assigned the number "nnn". We make
001226 ** sure "nnn" is not too big to avoid a denial of service attack when
001227 ** the SQL statement comes from an external source.
001228 **
001229 ** Wildcards of the form ":aaa", "@aaa", or "$aaa" are assigned the same number
001230 ** as the previous instance of the same wildcard. Or if this is the first
001231 ** instance of the wildcard, the next sequential variable number is
001232 ** assigned.
001233 */
001234 void sqlite3ExprAssignVarNumber(Parse *pParse, Expr *pExpr, u32 n){
001235 sqlite3 *db = pParse->db;
001236 const char *z;
001237 ynVar x;
001238
001239 if( pExpr==0 ) return;
001240 assert( !ExprHasProperty(pExpr, EP_IntValue|EP_Reduced|EP_TokenOnly) );
001241 z = pExpr->u.zToken;
001242 assert( z!=0 );
001243 assert( z[0]!=0 );
001244 assert( n==(u32)sqlite3Strlen30(z) );
001245 if( z[1]==0 ){
001246 /* Wildcard of the form "?". Assign the next variable number */
001247 assert( z[0]=='?' );
001248 x = (ynVar)(++pParse->nVar);
001249 }else{
001250 int doAdd = 0;
001251 if( z[0]=='?' ){
001252 /* Wildcard of the form "?nnn". Convert "nnn" to an integer and
001253 ** use it as the variable number */
001254 i64 i;
001255 int bOk;
001256 if( n==2 ){ /*OPTIMIZATION-IF-TRUE*/
001257 i = z[1]-'0'; /* The common case of ?N for a single digit N */
001258 bOk = 1;
001259 }else{
001260 bOk = 0==sqlite3Atoi64(&z[1], &i, n-1, SQLITE_UTF8);
001261 }
001262 testcase( i==0 );
001263 testcase( i==1 );
001264 testcase( i==db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER]-1 );
001265 testcase( i==db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER] );
001266 if( bOk==0 || i<1 || i>db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER] ){
001267 sqlite3ErrorMsg(pParse, "variable number must be between ?1 and ?%d",
001268 db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER]);
001269 sqlite3RecordErrorOffsetOfExpr(pParse->db, pExpr);
001270 return;
001271 }
001272 x = (ynVar)i;
001273 if( x>pParse->nVar ){
001274 pParse->nVar = (int)x;
001275 doAdd = 1;
001276 }else if( sqlite3VListNumToName(pParse->pVList, x)==0 ){
001277 doAdd = 1;
001278 }
001279 }else{
001280 /* Wildcards like ":aaa", "$aaa" or "@aaa". Reuse the same variable
001281 ** number as the prior appearance of the same name, or if the name
001282 ** has never appeared before, reuse the same variable number
001283 */
001284 x = (ynVar)sqlite3VListNameToNum(pParse->pVList, z, n);
001285 if( x==0 ){
001286 x = (ynVar)(++pParse->nVar);
001287 doAdd = 1;
001288 }
001289 }
001290 if( doAdd ){
001291 pParse->pVList = sqlite3VListAdd(db, pParse->pVList, z, n, x);
001292 }
001293 }
001294 pExpr->iColumn = x;
001295 if( x>db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER] ){
001296 sqlite3ErrorMsg(pParse, "too many SQL variables");
001297 sqlite3RecordErrorOffsetOfExpr(pParse->db, pExpr);
001298 }
001299 }
001300
001301 /*
001302 ** Recursively delete an expression tree.
001303 */
001304 static SQLITE_NOINLINE void sqlite3ExprDeleteNN(sqlite3 *db, Expr *p){
001305 assert( p!=0 );
001306 assert( db!=0 );
001307 assert( !ExprUseUValue(p) || p->u.iValue>=0 );
001308 assert( !ExprUseYWin(p) || !ExprUseYSub(p) );
001309 assert( !ExprUseYWin(p) || p->y.pWin!=0 || db->mallocFailed );
001310 assert( p->op!=TK_FUNCTION || !ExprUseYSub(p) );
001311 #ifdef SQLITE_DEBUG
001312 if( ExprHasProperty(p, EP_Leaf) && !ExprHasProperty(p, EP_TokenOnly) ){
001313 assert( p->pLeft==0 );
001314 assert( p->pRight==0 );
001315 assert( !ExprUseXSelect(p) || p->x.pSelect==0 );
001316 assert( !ExprUseXList(p) || p->x.pList==0 );
001317 }
001318 #endif
001319 if( !ExprHasProperty(p, (EP_TokenOnly|EP_Leaf)) ){
001320 /* The Expr.x union is never used at the same time as Expr.pRight */
001321 assert( (ExprUseXList(p) && p->x.pList==0) || p->pRight==0 );
001322 if( p->pLeft && p->op!=TK_SELECT_COLUMN ) sqlite3ExprDeleteNN(db, p->pLeft);
001323 if( p->pRight ){
001324 assert( !ExprHasProperty(p, EP_WinFunc) );
001325 sqlite3ExprDeleteNN(db, p->pRight);
001326 }else if( ExprUseXSelect(p) ){
001327 assert( !ExprHasProperty(p, EP_WinFunc) );
001328 sqlite3SelectDelete(db, p->x.pSelect);
001329 }else{
001330 sqlite3ExprListDelete(db, p->x.pList);
001331 #ifndef SQLITE_OMIT_WINDOWFUNC
001332 if( ExprHasProperty(p, EP_WinFunc) ){
001333 sqlite3WindowDelete(db, p->y.pWin);
001334 }
001335 #endif
001336 }
001337 }
001338 if( !ExprHasProperty(p, EP_Static) ){
001339 sqlite3DbNNFreeNN(db, p);
001340 }
001341 }
001342 void sqlite3ExprDelete(sqlite3 *db, Expr *p){
001343 if( p ) sqlite3ExprDeleteNN(db, p);
001344 }
001345
001346 /*
001347 ** Clear both elements of an OnOrUsing object
001348 */
001349 void sqlite3ClearOnOrUsing(sqlite3 *db, OnOrUsing *p){
001350 if( p==0 ){
001351 /* Nothing to clear */
001352 }else if( p->pOn ){
001353 sqlite3ExprDeleteNN(db, p->pOn);
001354 }else if( p->pUsing ){
001355 sqlite3IdListDelete(db, p->pUsing);
001356 }
001357 }
001358
001359 /*
001360 ** Arrange to cause pExpr to be deleted when the pParse is deleted.
001361 ** This is similar to sqlite3ExprDelete() except that the delete is
001362 ** deferred until the pParse is deleted.
001363 **
001364 ** The pExpr might be deleted immediately on an OOM error.
001365 **
001366 ** The deferred delete is (currently) implemented by adding the
001367 ** pExpr to the pParse->pConstExpr list with a register number of 0.
001368 */
001369 void sqlite3ExprDeferredDelete(Parse *pParse, Expr *pExpr){
001370 sqlite3ParserAddCleanup(pParse,
001371 (void(*)(sqlite3*,void*))sqlite3ExprDelete,
001372 pExpr);
001373 }
001374
001375 /* Invoke sqlite3RenameExprUnmap() and sqlite3ExprDelete() on the
001376 ** expression.
001377 */
001378 void sqlite3ExprUnmapAndDelete(Parse *pParse, Expr *p){
001379 if( p ){
001380 if( IN_RENAME_OBJECT ){
001381 sqlite3RenameExprUnmap(pParse, p);
001382 }
001383 sqlite3ExprDeleteNN(pParse->db, p);
001384 }
001385 }
001386
001387 /*
001388 ** Return the number of bytes allocated for the expression structure
001389 ** passed as the first argument. This is always one of EXPR_FULLSIZE,
001390 ** EXPR_REDUCEDSIZE or EXPR_TOKENONLYSIZE.
001391 */
001392 static int exprStructSize(const Expr *p){
001393 if( ExprHasProperty(p, EP_TokenOnly) ) return EXPR_TOKENONLYSIZE;
001394 if( ExprHasProperty(p, EP_Reduced) ) return EXPR_REDUCEDSIZE;
001395 return EXPR_FULLSIZE;
001396 }
001397
001398 /*
001399 ** The dupedExpr*Size() routines each return the number of bytes required
001400 ** to store a copy of an expression or expression tree. They differ in
001401 ** how much of the tree is measured.
001402 **
001403 ** dupedExprStructSize() Size of only the Expr structure
001404 ** dupedExprNodeSize() Size of Expr + space for token
001405 ** dupedExprSize() Expr + token + subtree components
001406 **
001407 ***************************************************************************
001408 **
001409 ** The dupedExprStructSize() function returns two values OR-ed together:
001410 ** (1) the space required for a copy of the Expr structure only and
001411 ** (2) the EP_xxx flags that indicate what the structure size should be.
001412 ** The return values is always one of:
001413 **
001414 ** EXPR_FULLSIZE
001415 ** EXPR_REDUCEDSIZE | EP_Reduced
001416 ** EXPR_TOKENONLYSIZE | EP_TokenOnly
001417 **
001418 ** The size of the structure can be found by masking the return value
001419 ** of this routine with 0xfff. The flags can be found by masking the
001420 ** return value with EP_Reduced|EP_TokenOnly.
001421 **
001422 ** Note that with flags==EXPRDUP_REDUCE, this routines works on full-size
001423 ** (unreduced) Expr objects as they or originally constructed by the parser.
001424 ** During expression analysis, extra information is computed and moved into
001425 ** later parts of the Expr object and that extra information might get chopped
001426 ** off if the expression is reduced. Note also that it does not work to
001427 ** make an EXPRDUP_REDUCE copy of a reduced expression. It is only legal
001428 ** to reduce a pristine expression tree from the parser. The implementation
001429 ** of dupedExprStructSize() contain multiple assert() statements that attempt
001430 ** to enforce this constraint.
001431 */
001432 static int dupedExprStructSize(const Expr *p, int flags){
001433 int nSize;
001434 assert( flags==EXPRDUP_REDUCE || flags==0 ); /* Only one flag value allowed */
001435 assert( EXPR_FULLSIZE<=0xfff );
001436 assert( (0xfff & (EP_Reduced|EP_TokenOnly))==0 );
001437 if( 0==flags || p->op==TK_SELECT_COLUMN
001438 #ifndef SQLITE_OMIT_WINDOWFUNC
001439 || ExprHasProperty(p, EP_WinFunc)
001440 #endif
001441 ){
001442 nSize = EXPR_FULLSIZE;
001443 }else{
001444 assert( !ExprHasProperty(p, EP_TokenOnly|EP_Reduced) );
001445 assert( !ExprHasProperty(p, EP_OuterON) );
001446 assert( !ExprHasVVAProperty(p, EP_NoReduce) );
001447 if( p->pLeft || p->x.pList ){
001448 nSize = EXPR_REDUCEDSIZE | EP_Reduced;
001449 }else{
001450 assert( p->pRight==0 );
001451 nSize = EXPR_TOKENONLYSIZE | EP_TokenOnly;
001452 }
001453 }
001454 return nSize;
001455 }
001456
001457 /*
001458 ** This function returns the space in bytes required to store the copy
001459 ** of the Expr structure and a copy of the Expr.u.zToken string (if that
001460 ** string is defined.)
001461 */
001462 static int dupedExprNodeSize(const Expr *p, int flags){
001463 int nByte = dupedExprStructSize(p, flags) & 0xfff;
001464 if( !ExprHasProperty(p, EP_IntValue) && p->u.zToken ){
001465 nByte += sqlite3Strlen30NN(p->u.zToken)+1;
001466 }
001467 return ROUND8(nByte);
001468 }
001469
001470 /*
001471 ** Return the number of bytes required to create a duplicate of the
001472 ** expression passed as the first argument. The second argument is a
001473 ** mask containing EXPRDUP_XXX flags.
001474 **
001475 ** The value returned includes space to create a copy of the Expr struct
001476 ** itself and the buffer referred to by Expr.u.zToken, if any.
001477 **
001478 ** If the EXPRDUP_REDUCE flag is set, then the return value includes
001479 ** space to duplicate all Expr nodes in the tree formed by Expr.pLeft
001480 ** and Expr.pRight variables (but not for any structures pointed to or
001481 ** descended from the Expr.x.pList or Expr.x.pSelect variables).
001482 */
001483 static int dupedExprSize(const Expr *p, int flags){
001484 int nByte = 0;
001485 if( p ){
001486 nByte = dupedExprNodeSize(p, flags);
001487 if( flags&EXPRDUP_REDUCE ){
001488 nByte += dupedExprSize(p->pLeft, flags) + dupedExprSize(p->pRight, flags);
001489 }
001490 }
001491 return nByte;
001492 }
001493
001494 /*
001495 ** This function is similar to sqlite3ExprDup(), except that if pzBuffer
001496 ** is not NULL then *pzBuffer is assumed to point to a buffer large enough
001497 ** to store the copy of expression p, the copies of p->u.zToken
001498 ** (if applicable), and the copies of the p->pLeft and p->pRight expressions,
001499 ** if any. Before returning, *pzBuffer is set to the first byte past the
001500 ** portion of the buffer copied into by this function.
001501 */
001502 static Expr *exprDup(sqlite3 *db, const Expr *p, int dupFlags, u8 **pzBuffer){
001503 Expr *pNew; /* Value to return */
001504 u8 *zAlloc; /* Memory space from which to build Expr object */
001505 u32 staticFlag; /* EP_Static if space not obtained from malloc */
001506
001507 assert( db!=0 );
001508 assert( p );
001509 assert( dupFlags==0 || dupFlags==EXPRDUP_REDUCE );
001510 assert( pzBuffer==0 || dupFlags==EXPRDUP_REDUCE );
001511
001512 /* Figure out where to write the new Expr structure. */
001513 if( pzBuffer ){
001514 zAlloc = *pzBuffer;
001515 staticFlag = EP_Static;
001516 assert( zAlloc!=0 );
001517 }else{
001518 zAlloc = sqlite3DbMallocRawNN(db, dupedExprSize(p, dupFlags));
001519 staticFlag = 0;
001520 }
001521 pNew = (Expr *)zAlloc;
001522
001523 if( pNew ){
001524 /* Set nNewSize to the size allocated for the structure pointed to
001525 ** by pNew. This is either EXPR_FULLSIZE, EXPR_REDUCEDSIZE or
001526 ** EXPR_TOKENONLYSIZE. nToken is set to the number of bytes consumed
001527 ** by the copy of the p->u.zToken string (if any).
001528 */
001529 const unsigned nStructSize = dupedExprStructSize(p, dupFlags);
001530 const int nNewSize = nStructSize & 0xfff;
001531 int nToken;
001532 if( !ExprHasProperty(p, EP_IntValue) && p->u.zToken ){
001533 nToken = sqlite3Strlen30(p->u.zToken) + 1;
001534 }else{
001535 nToken = 0;
001536 }
001537 if( dupFlags ){
001538 assert( ExprHasProperty(p, EP_Reduced)==0 );
001539 memcpy(zAlloc, p, nNewSize);
001540 }else{
001541 u32 nSize = (u32)exprStructSize(p);
001542 memcpy(zAlloc, p, nSize);
001543 if( nSize<EXPR_FULLSIZE ){
001544 memset(&zAlloc[nSize], 0, EXPR_FULLSIZE-nSize);
001545 }
001546 }
001547
001548 /* Set the EP_Reduced, EP_TokenOnly, and EP_Static flags appropriately. */
001549 pNew->flags &= ~(EP_Reduced|EP_TokenOnly|EP_Static);
001550 pNew->flags |= nStructSize & (EP_Reduced|EP_TokenOnly);
001551 pNew->flags |= staticFlag;
001552 ExprClearVVAProperties(pNew);
001553 if( dupFlags ){
001554 ExprSetVVAProperty(pNew, EP_Immutable);
001555 }
001556
001557 /* Copy the p->u.zToken string, if any. */
001558 if( nToken ){
001559 char *zToken = pNew->u.zToken = (char*)&zAlloc[nNewSize];
001560 memcpy(zToken, p->u.zToken, nToken);
001561 }
001562
001563 if( 0==((p->flags|pNew->flags) & (EP_TokenOnly|EP_Leaf)) ){
001564 /* Fill in the pNew->x.pSelect or pNew->x.pList member. */
001565 if( ExprUseXSelect(p) ){
001566 pNew->x.pSelect = sqlite3SelectDup(db, p->x.pSelect, dupFlags);
001567 }else{
001568 pNew->x.pList = sqlite3ExprListDup(db, p->x.pList, dupFlags);
001569 }
001570 }
001571
001572 /* Fill in pNew->pLeft and pNew->pRight. */
001573 if( ExprHasProperty(pNew, EP_Reduced|EP_TokenOnly|EP_WinFunc) ){
001574 zAlloc += dupedExprNodeSize(p, dupFlags);
001575 if( !ExprHasProperty(pNew, EP_TokenOnly|EP_Leaf) ){
001576 pNew->pLeft = p->pLeft ?
001577 exprDup(db, p->pLeft, EXPRDUP_REDUCE, &zAlloc) : 0;
001578 pNew->pRight = p->pRight ?
001579 exprDup(db, p->pRight, EXPRDUP_REDUCE, &zAlloc) : 0;
001580 }
001581 #ifndef SQLITE_OMIT_WINDOWFUNC
001582 if( ExprHasProperty(p, EP_WinFunc) ){
001583 pNew->y.pWin = sqlite3WindowDup(db, pNew, p->y.pWin);
001584 assert( ExprHasProperty(pNew, EP_WinFunc) );
001585 }
001586 #endif /* SQLITE_OMIT_WINDOWFUNC */
001587 if( pzBuffer ){
001588 *pzBuffer = zAlloc;
001589 }
001590 }else{
001591 if( !ExprHasProperty(p, EP_TokenOnly|EP_Leaf) ){
001592 if( pNew->op==TK_SELECT_COLUMN ){
001593 pNew->pLeft = p->pLeft;
001594 assert( p->pRight==0 || p->pRight==p->pLeft
001595 || ExprHasProperty(p->pLeft, EP_Subquery) );
001596 }else{
001597 pNew->pLeft = sqlite3ExprDup(db, p->pLeft, 0);
001598 }
001599 pNew->pRight = sqlite3ExprDup(db, p->pRight, 0);
001600 }
001601 }
001602 }
001603 return pNew;
001604 }
001605
001606 /*
001607 ** Create and return a deep copy of the object passed as the second
001608 ** argument. If an OOM condition is encountered, NULL is returned
001609 ** and the db->mallocFailed flag set.
001610 */
001611 #ifndef SQLITE_OMIT_CTE
001612 With *sqlite3WithDup(sqlite3 *db, With *p){
001613 With *pRet = 0;
001614 if( p ){
001615 sqlite3_int64 nByte = sizeof(*p) + sizeof(p->a[0]) * (p->nCte-1);
001616 pRet = sqlite3DbMallocZero(db, nByte);
001617 if( pRet ){
001618 int i;
001619 pRet->nCte = p->nCte;
001620 for(i=0; i<p->nCte; i++){
001621 pRet->a[i].pSelect = sqlite3SelectDup(db, p->a[i].pSelect, 0);
001622 pRet->a[i].pCols = sqlite3ExprListDup(db, p->a[i].pCols, 0);
001623 pRet->a[i].zName = sqlite3DbStrDup(db, p->a[i].zName);
001624 pRet->a[i].eM10d = p->a[i].eM10d;
001625 }
001626 }
001627 }
001628 return pRet;
001629 }
001630 #else
001631 # define sqlite3WithDup(x,y) 0
001632 #endif
001633
001634 #ifndef SQLITE_OMIT_WINDOWFUNC
001635 /*
001636 ** The gatherSelectWindows() procedure and its helper routine
001637 ** gatherSelectWindowsCallback() are used to scan all the expressions
001638 ** an a newly duplicated SELECT statement and gather all of the Window
001639 ** objects found there, assembling them onto the linked list at Select->pWin.
001640 */
001641 static int gatherSelectWindowsCallback(Walker *pWalker, Expr *pExpr){
001642 if( pExpr->op==TK_FUNCTION && ExprHasProperty(pExpr, EP_WinFunc) ){
001643 Select *pSelect = pWalker->u.pSelect;
001644 Window *pWin = pExpr->y.pWin;
001645 assert( pWin );
001646 assert( IsWindowFunc(pExpr) );
001647 assert( pWin->ppThis==0 );
001648 sqlite3WindowLink(pSelect, pWin);
001649 }
001650 return WRC_Continue;
001651 }
001652 static int gatherSelectWindowsSelectCallback(Walker *pWalker, Select *p){
001653 return p==pWalker->u.pSelect ? WRC_Continue : WRC_Prune;
001654 }
001655 static void gatherSelectWindows(Select *p){
001656 Walker w;
001657 w.xExprCallback = gatherSelectWindowsCallback;
001658 w.xSelectCallback = gatherSelectWindowsSelectCallback;
001659 w.xSelectCallback2 = 0;
001660 w.pParse = 0;
001661 w.u.pSelect = p;
001662 sqlite3WalkSelect(&w, p);
001663 }
001664 #endif
001665
001666
001667 /*
001668 ** The following group of routines make deep copies of expressions,
001669 ** expression lists, ID lists, and select statements. The copies can
001670 ** be deleted (by being passed to their respective ...Delete() routines)
001671 ** without effecting the originals.
001672 **
001673 ** The expression list, ID, and source lists return by sqlite3ExprListDup(),
001674 ** sqlite3IdListDup(), and sqlite3SrcListDup() can not be further expanded
001675 ** by subsequent calls to sqlite*ListAppend() routines.
001676 **
001677 ** Any tables that the SrcList might point to are not duplicated.
001678 **
001679 ** The flags parameter contains a combination of the EXPRDUP_XXX flags.
001680 ** If the EXPRDUP_REDUCE flag is set, then the structure returned is a
001681 ** truncated version of the usual Expr structure that will be stored as
001682 ** part of the in-memory representation of the database schema.
001683 */
001684 Expr *sqlite3ExprDup(sqlite3 *db, const Expr *p, int flags){
001685 assert( flags==0 || flags==EXPRDUP_REDUCE );
001686 return p ? exprDup(db, p, flags, 0) : 0;
001687 }
001688 ExprList *sqlite3ExprListDup(sqlite3 *db, const ExprList *p, int flags){
001689 ExprList *pNew;
001690 struct ExprList_item *pItem;
001691 const struct ExprList_item *pOldItem;
001692 int i;
001693 Expr *pPriorSelectColOld = 0;
001694 Expr *pPriorSelectColNew = 0;
001695 assert( db!=0 );
001696 if( p==0 ) return 0;
001697 pNew = sqlite3DbMallocRawNN(db, sqlite3DbMallocSize(db, p));
001698 if( pNew==0 ) return 0;
001699 pNew->nExpr = p->nExpr;
001700 pNew->nAlloc = p->nAlloc;
001701 pItem = pNew->a;
001702 pOldItem = p->a;
001703 for(i=0; i<p->nExpr; i++, pItem++, pOldItem++){
001704 Expr *pOldExpr = pOldItem->pExpr;
001705 Expr *pNewExpr;
001706 pItem->pExpr = sqlite3ExprDup(db, pOldExpr, flags);
001707 if( pOldExpr
001708 && pOldExpr->op==TK_SELECT_COLUMN
001709 && (pNewExpr = pItem->pExpr)!=0
001710 ){
001711 if( pNewExpr->pRight ){
001712 pPriorSelectColOld = pOldExpr->pRight;
001713 pPriorSelectColNew = pNewExpr->pRight;
001714 pNewExpr->pLeft = pNewExpr->pRight;
001715 }else{
001716 if( pOldExpr->pLeft!=pPriorSelectColOld ){
001717 pPriorSelectColOld = pOldExpr->pLeft;
001718 pPriorSelectColNew = sqlite3ExprDup(db, pPriorSelectColOld, flags);
001719 pNewExpr->pRight = pPriorSelectColNew;
001720 }
001721 pNewExpr->pLeft = pPriorSelectColNew;
001722 }
001723 }
001724 pItem->zEName = sqlite3DbStrDup(db, pOldItem->zEName);
001725 pItem->fg = pOldItem->fg;
001726 pItem->fg.done = 0;
001727 pItem->u = pOldItem->u;
001728 }
001729 return pNew;
001730 }
001731
001732 /*
001733 ** If cursors, triggers, views and subqueries are all omitted from
001734 ** the build, then none of the following routines, except for
001735 ** sqlite3SelectDup(), can be called. sqlite3SelectDup() is sometimes
001736 ** called with a NULL argument.
001737 */
001738 #if !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_TRIGGER) \
001739 || !defined(SQLITE_OMIT_SUBQUERY)
001740 SrcList *sqlite3SrcListDup(sqlite3 *db, const SrcList *p, int flags){
001741 SrcList *pNew;
001742 int i;
001743 int nByte;
001744 assert( db!=0 );
001745 if( p==0 ) return 0;
001746 nByte = sizeof(*p) + (p->nSrc>0 ? sizeof(p->a[0]) * (p->nSrc-1) : 0);
001747 pNew = sqlite3DbMallocRawNN(db, nByte );
001748 if( pNew==0 ) return 0;
001749 pNew->nSrc = pNew->nAlloc = p->nSrc;
001750 for(i=0; i<p->nSrc; i++){
001751 SrcItem *pNewItem = &pNew->a[i];
001752 const SrcItem *pOldItem = &p->a[i];
001753 Table *pTab;
001754 pNewItem->pSchema = pOldItem->pSchema;
001755 pNewItem->zDatabase = sqlite3DbStrDup(db, pOldItem->zDatabase);
001756 pNewItem->zName = sqlite3DbStrDup(db, pOldItem->zName);
001757 pNewItem->zAlias = sqlite3DbStrDup(db, pOldItem->zAlias);
001758 pNewItem->fg = pOldItem->fg;
001759 pNewItem->iCursor = pOldItem->iCursor;
001760 pNewItem->addrFillSub = pOldItem->addrFillSub;
001761 pNewItem->regReturn = pOldItem->regReturn;
001762 if( pNewItem->fg.isIndexedBy ){
001763 pNewItem->u1.zIndexedBy = sqlite3DbStrDup(db, pOldItem->u1.zIndexedBy);
001764 }
001765 pNewItem->u2 = pOldItem->u2;
001766 if( pNewItem->fg.isCte ){
001767 pNewItem->u2.pCteUse->nUse++;
001768 }
001769 if( pNewItem->fg.isTabFunc ){
001770 pNewItem->u1.pFuncArg =
001771 sqlite3ExprListDup(db, pOldItem->u1.pFuncArg, flags);
001772 }
001773 pTab = pNewItem->pTab = pOldItem->pTab;
001774 if( pTab ){
001775 pTab->nTabRef++;
001776 }
001777 pNewItem->pSelect = sqlite3SelectDup(db, pOldItem->pSelect, flags);
001778 if( pOldItem->fg.isUsing ){
001779 assert( pNewItem->fg.isUsing );
001780 pNewItem->u3.pUsing = sqlite3IdListDup(db, pOldItem->u3.pUsing);
001781 }else{
001782 pNewItem->u3.pOn = sqlite3ExprDup(db, pOldItem->u3.pOn, flags);
001783 }
001784 pNewItem->colUsed = pOldItem->colUsed;
001785 }
001786 return pNew;
001787 }
001788 IdList *sqlite3IdListDup(sqlite3 *db, const IdList *p){
001789 IdList *pNew;
001790 int i;
001791 assert( db!=0 );
001792 if( p==0 ) return 0;
001793 assert( p->eU4!=EU4_EXPR );
001794 pNew = sqlite3DbMallocRawNN(db, sizeof(*pNew)+(p->nId-1)*sizeof(p->a[0]) );
001795 if( pNew==0 ) return 0;
001796 pNew->nId = p->nId;
001797 pNew->eU4 = p->eU4;
001798 for(i=0; i<p->nId; i++){
001799 struct IdList_item *pNewItem = &pNew->a[i];
001800 const struct IdList_item *pOldItem = &p->a[i];
001801 pNewItem->zName = sqlite3DbStrDup(db, pOldItem->zName);
001802 pNewItem->u4 = pOldItem->u4;
001803 }
001804 return pNew;
001805 }
001806 Select *sqlite3SelectDup(sqlite3 *db, const Select *pDup, int flags){
001807 Select *pRet = 0;
001808 Select *pNext = 0;
001809 Select **pp = &pRet;
001810 const Select *p;
001811
001812 assert( db!=0 );
001813 for(p=pDup; p; p=p->pPrior){
001814 Select *pNew = sqlite3DbMallocRawNN(db, sizeof(*p) );
001815 if( pNew==0 ) break;
001816 pNew->pEList = sqlite3ExprListDup(db, p->pEList, flags);
001817 pNew->pSrc = sqlite3SrcListDup(db, p->pSrc, flags);
001818 pNew->pWhere = sqlite3ExprDup(db, p->pWhere, flags);
001819 pNew->pGroupBy = sqlite3ExprListDup(db, p->pGroupBy, flags);
001820 pNew->pHaving = sqlite3ExprDup(db, p->pHaving, flags);
001821 pNew->pOrderBy = sqlite3ExprListDup(db, p->pOrderBy, flags);
001822 pNew->op = p->op;
001823 pNew->pNext = pNext;
001824 pNew->pPrior = 0;
001825 pNew->pLimit = sqlite3ExprDup(db, p->pLimit, flags);
001826 pNew->iLimit = 0;
001827 pNew->iOffset = 0;
001828 pNew->selFlags = p->selFlags & ~SF_UsesEphemeral;
001829 pNew->addrOpenEphm[0] = -1;
001830 pNew->addrOpenEphm[1] = -1;
001831 pNew->nSelectRow = p->nSelectRow;
001832 pNew->pWith = sqlite3WithDup(db, p->pWith);
001833 #ifndef SQLITE_OMIT_WINDOWFUNC
001834 pNew->pWin = 0;
001835 pNew->pWinDefn = sqlite3WindowListDup(db, p->pWinDefn);
001836 if( p->pWin && db->mallocFailed==0 ) gatherSelectWindows(pNew);
001837 #endif
001838 pNew->selId = p->selId;
001839 if( db->mallocFailed ){
001840 /* Any prior OOM might have left the Select object incomplete.
001841 ** Delete the whole thing rather than allow an incomplete Select
001842 ** to be used by the code generator. */
001843 pNew->pNext = 0;
001844 sqlite3SelectDelete(db, pNew);
001845 break;
001846 }
001847 *pp = pNew;
001848 pp = &pNew->pPrior;
001849 pNext = pNew;
001850 }
001851
001852 return pRet;
001853 }
001854 #else
001855 Select *sqlite3SelectDup(sqlite3 *db, const Select *p, int flags){
001856 assert( p==0 );
001857 return 0;
001858 }
001859 #endif
001860
001861
001862 /*
001863 ** Add a new element to the end of an expression list. If pList is
001864 ** initially NULL, then create a new expression list.
001865 **
001866 ** The pList argument must be either NULL or a pointer to an ExprList
001867 ** obtained from a prior call to sqlite3ExprListAppend(). This routine
001868 ** may not be used with an ExprList obtained from sqlite3ExprListDup().
001869 ** Reason: This routine assumes that the number of slots in pList->a[]
001870 ** is a power of two. That is true for sqlite3ExprListAppend() returns
001871 ** but is not necessarily true from the return value of sqlite3ExprListDup().
001872 **
001873 ** If a memory allocation error occurs, the entire list is freed and
001874 ** NULL is returned. If non-NULL is returned, then it is guaranteed
001875 ** that the new entry was successfully appended.
001876 */
001877 static const struct ExprList_item zeroItem = {0};
001878 SQLITE_NOINLINE ExprList *sqlite3ExprListAppendNew(
001879 sqlite3 *db, /* Database handle. Used for memory allocation */
001880 Expr *pExpr /* Expression to be appended. Might be NULL */
001881 ){
001882 struct ExprList_item *pItem;
001883 ExprList *pList;
001884
001885 pList = sqlite3DbMallocRawNN(db, sizeof(ExprList)+sizeof(pList->a[0])*4 );
001886 if( pList==0 ){
001887 sqlite3ExprDelete(db, pExpr);
001888 return 0;
001889 }
001890 pList->nAlloc = 4;
001891 pList->nExpr = 1;
001892 pItem = &pList->a[0];
001893 *pItem = zeroItem;
001894 pItem->pExpr = pExpr;
001895 return pList;
001896 }
001897 SQLITE_NOINLINE ExprList *sqlite3ExprListAppendGrow(
001898 sqlite3 *db, /* Database handle. Used for memory allocation */
001899 ExprList *pList, /* List to which to append. Might be NULL */
001900 Expr *pExpr /* Expression to be appended. Might be NULL */
001901 ){
001902 struct ExprList_item *pItem;
001903 ExprList *pNew;
001904 pList->nAlloc *= 2;
001905 pNew = sqlite3DbRealloc(db, pList,
001906 sizeof(*pList)+(pList->nAlloc-1)*sizeof(pList->a[0]));
001907 if( pNew==0 ){
001908 sqlite3ExprListDelete(db, pList);
001909 sqlite3ExprDelete(db, pExpr);
001910 return 0;
001911 }else{
001912 pList = pNew;
001913 }
001914 pItem = &pList->a[pList->nExpr++];
001915 *pItem = zeroItem;
001916 pItem->pExpr = pExpr;
001917 return pList;
001918 }
001919 ExprList *sqlite3ExprListAppend(
001920 Parse *pParse, /* Parsing context */
001921 ExprList *pList, /* List to which to append. Might be NULL */
001922 Expr *pExpr /* Expression to be appended. Might be NULL */
001923 ){
001924 struct ExprList_item *pItem;
001925 if( pList==0 ){
001926 return sqlite3ExprListAppendNew(pParse->db,pExpr);
001927 }
001928 if( pList->nAlloc<pList->nExpr+1 ){
001929 return sqlite3ExprListAppendGrow(pParse->db,pList,pExpr);
001930 }
001931 pItem = &pList->a[pList->nExpr++];
001932 *pItem = zeroItem;
001933 pItem->pExpr = pExpr;
001934 return pList;
001935 }
001936
001937 /*
001938 ** pColumns and pExpr form a vector assignment which is part of the SET
001939 ** clause of an UPDATE statement. Like this:
001940 **
001941 ** (a,b,c) = (expr1,expr2,expr3)
001942 ** Or: (a,b,c) = (SELECT x,y,z FROM ....)
001943 **
001944 ** For each term of the vector assignment, append new entries to the
001945 ** expression list pList. In the case of a subquery on the RHS, append
001946 ** TK_SELECT_COLUMN expressions.
001947 */
001948 ExprList *sqlite3ExprListAppendVector(
001949 Parse *pParse, /* Parsing context */
001950 ExprList *pList, /* List to which to append. Might be NULL */
001951 IdList *pColumns, /* List of names of LHS of the assignment */
001952 Expr *pExpr /* Vector expression to be appended. Might be NULL */
001953 ){
001954 sqlite3 *db = pParse->db;
001955 int n;
001956 int i;
001957 int iFirst = pList ? pList->nExpr : 0;
001958 /* pColumns can only be NULL due to an OOM but an OOM will cause an
001959 ** exit prior to this routine being invoked */
001960 if( NEVER(pColumns==0) ) goto vector_append_error;
001961 if( pExpr==0 ) goto vector_append_error;
001962
001963 /* If the RHS is a vector, then we can immediately check to see that
001964 ** the size of the RHS and LHS match. But if the RHS is a SELECT,
001965 ** wildcards ("*") in the result set of the SELECT must be expanded before
001966 ** we can do the size check, so defer the size check until code generation.
001967 */
001968 if( pExpr->op!=TK_SELECT && pColumns->nId!=(n=sqlite3ExprVectorSize(pExpr)) ){
001969 sqlite3ErrorMsg(pParse, "%d columns assigned %d values",
001970 pColumns->nId, n);
001971 goto vector_append_error;
001972 }
001973
001974 for(i=0; i<pColumns->nId; i++){
001975 Expr *pSubExpr = sqlite3ExprForVectorField(pParse, pExpr, i, pColumns->nId);
001976 assert( pSubExpr!=0 || db->mallocFailed );
001977 if( pSubExpr==0 ) continue;
001978 pList = sqlite3ExprListAppend(pParse, pList, pSubExpr);
001979 if( pList ){
001980 assert( pList->nExpr==iFirst+i+1 );
001981 pList->a[pList->nExpr-1].zEName = pColumns->a[i].zName;
001982 pColumns->a[i].zName = 0;
001983 }
001984 }
001985
001986 if( !db->mallocFailed && pExpr->op==TK_SELECT && ALWAYS(pList!=0) ){
001987 Expr *pFirst = pList->a[iFirst].pExpr;
001988 assert( pFirst!=0 );
001989 assert( pFirst->op==TK_SELECT_COLUMN );
001990
001991 /* Store the SELECT statement in pRight so it will be deleted when
001992 ** sqlite3ExprListDelete() is called */
001993 pFirst->pRight = pExpr;
001994 pExpr = 0;
001995
001996 /* Remember the size of the LHS in iTable so that we can check that
001997 ** the RHS and LHS sizes match during code generation. */
001998 pFirst->iTable = pColumns->nId;
001999 }
002000
002001 vector_append_error:
002002 sqlite3ExprUnmapAndDelete(pParse, pExpr);
002003 sqlite3IdListDelete(db, pColumns);
002004 return pList;
002005 }
002006
002007 /*
002008 ** Set the sort order for the last element on the given ExprList.
002009 */
002010 void sqlite3ExprListSetSortOrder(ExprList *p, int iSortOrder, int eNulls){
002011 struct ExprList_item *pItem;
002012 if( p==0 ) return;
002013 assert( p->nExpr>0 );
002014
002015 assert( SQLITE_SO_UNDEFINED<0 && SQLITE_SO_ASC==0 && SQLITE_SO_DESC>0 );
002016 assert( iSortOrder==SQLITE_SO_UNDEFINED
002017 || iSortOrder==SQLITE_SO_ASC
002018 || iSortOrder==SQLITE_SO_DESC
002019 );
002020 assert( eNulls==SQLITE_SO_UNDEFINED
002021 || eNulls==SQLITE_SO_ASC
002022 || eNulls==SQLITE_SO_DESC
002023 );
002024
002025 pItem = &p->a[p->nExpr-1];
002026 assert( pItem->fg.bNulls==0 );
002027 if( iSortOrder==SQLITE_SO_UNDEFINED ){
002028 iSortOrder = SQLITE_SO_ASC;
002029 }
002030 pItem->fg.sortFlags = (u8)iSortOrder;
002031
002032 if( eNulls!=SQLITE_SO_UNDEFINED ){
002033 pItem->fg.bNulls = 1;
002034 if( iSortOrder!=eNulls ){
002035 pItem->fg.sortFlags |= KEYINFO_ORDER_BIGNULL;
002036 }
002037 }
002038 }
002039
002040 /*
002041 ** Set the ExprList.a[].zEName element of the most recently added item
002042 ** on the expression list.
002043 **
002044 ** pList might be NULL following an OOM error. But pName should never be
002045 ** NULL. If a memory allocation fails, the pParse->db->mallocFailed flag
002046 ** is set.
002047 */
002048 void sqlite3ExprListSetName(
002049 Parse *pParse, /* Parsing context */
002050 ExprList *pList, /* List to which to add the span. */
002051 const Token *pName, /* Name to be added */
002052 int dequote /* True to cause the name to be dequoted */
002053 ){
002054 assert( pList!=0 || pParse->db->mallocFailed!=0 );
002055 assert( pParse->eParseMode!=PARSE_MODE_UNMAP || dequote==0 );
002056 if( pList ){
002057 struct ExprList_item *pItem;
002058 assert( pList->nExpr>0 );
002059 pItem = &pList->a[pList->nExpr-1];
002060 assert( pItem->zEName==0 );
002061 assert( pItem->fg.eEName==ENAME_NAME );
002062 pItem->zEName = sqlite3DbStrNDup(pParse->db, pName->z, pName->n);
002063 if( dequote ){
002064 /* If dequote==0, then pName->z does not point to part of a DDL
002065 ** statement handled by the parser. And so no token need be added
002066 ** to the token-map. */
002067 sqlite3Dequote(pItem->zEName);
002068 if( IN_RENAME_OBJECT ){
002069 sqlite3RenameTokenMap(pParse, (const void*)pItem->zEName, pName);
002070 }
002071 }
002072 }
002073 }
002074
002075 /*
002076 ** Set the ExprList.a[].zSpan element of the most recently added item
002077 ** on the expression list.
002078 **
002079 ** pList might be NULL following an OOM error. But pSpan should never be
002080 ** NULL. If a memory allocation fails, the pParse->db->mallocFailed flag
002081 ** is set.
002082 */
002083 void sqlite3ExprListSetSpan(
002084 Parse *pParse, /* Parsing context */
002085 ExprList *pList, /* List to which to add the span. */
002086 const char *zStart, /* Start of the span */
002087 const char *zEnd /* End of the span */
002088 ){
002089 sqlite3 *db = pParse->db;
002090 assert( pList!=0 || db->mallocFailed!=0 );
002091 if( pList ){
002092 struct ExprList_item *pItem = &pList->a[pList->nExpr-1];
002093 assert( pList->nExpr>0 );
002094 if( pItem->zEName==0 ){
002095 pItem->zEName = sqlite3DbSpanDup(db, zStart, zEnd);
002096 pItem->fg.eEName = ENAME_SPAN;
002097 }
002098 }
002099 }
002100
002101 /*
002102 ** If the expression list pEList contains more than iLimit elements,
002103 ** leave an error message in pParse.
002104 */
002105 void sqlite3ExprListCheckLength(
002106 Parse *pParse,
002107 ExprList *pEList,
002108 const char *zObject
002109 ){
002110 int mx = pParse->db->aLimit[SQLITE_LIMIT_COLUMN];
002111 testcase( pEList && pEList->nExpr==mx );
002112 testcase( pEList && pEList->nExpr==mx+1 );
002113 if( pEList && pEList->nExpr>mx ){
002114 sqlite3ErrorMsg(pParse, "too many columns in %s", zObject);
002115 }
002116 }
002117
002118 /*
002119 ** Delete an entire expression list.
002120 */
002121 static SQLITE_NOINLINE void exprListDeleteNN(sqlite3 *db, ExprList *pList){
002122 int i = pList->nExpr;
002123 struct ExprList_item *pItem = pList->a;
002124 assert( pList->nExpr>0 );
002125 assert( db!=0 );
002126 do{
002127 sqlite3ExprDelete(db, pItem->pExpr);
002128 if( pItem->zEName ) sqlite3DbNNFreeNN(db, pItem->zEName);
002129 pItem++;
002130 }while( --i>0 );
002131 sqlite3DbNNFreeNN(db, pList);
002132 }
002133 void sqlite3ExprListDelete(sqlite3 *db, ExprList *pList){
002134 if( pList ) exprListDeleteNN(db, pList);
002135 }
002136
002137 /*
002138 ** Return the bitwise-OR of all Expr.flags fields in the given
002139 ** ExprList.
002140 */
002141 u32 sqlite3ExprListFlags(const ExprList *pList){
002142 int i;
002143 u32 m = 0;
002144 assert( pList!=0 );
002145 for(i=0; i<pList->nExpr; i++){
002146 Expr *pExpr = pList->a[i].pExpr;
002147 assert( pExpr!=0 );
002148 m |= pExpr->flags;
002149 }
002150 return m;
002151 }
002152
002153 /*
002154 ** This is a SELECT-node callback for the expression walker that
002155 ** always "fails". By "fail" in this case, we mean set
002156 ** pWalker->eCode to zero and abort.
002157 **
002158 ** This callback is used by multiple expression walkers.
002159 */
002160 int sqlite3SelectWalkFail(Walker *pWalker, Select *NotUsed){
002161 UNUSED_PARAMETER(NotUsed);
002162 pWalker->eCode = 0;
002163 return WRC_Abort;
002164 }
002165
002166 /*
002167 ** Check the input string to see if it is "true" or "false" (in any case).
002168 **
002169 ** If the string is.... Return
002170 ** "true" EP_IsTrue
002171 ** "false" EP_IsFalse
002172 ** anything else 0
002173 */
002174 u32 sqlite3IsTrueOrFalse(const char *zIn){
002175 if( sqlite3StrICmp(zIn, "true")==0 ) return EP_IsTrue;
002176 if( sqlite3StrICmp(zIn, "false")==0 ) return EP_IsFalse;
002177 return 0;
002178 }
002179
002180
002181 /*
002182 ** If the input expression is an ID with the name "true" or "false"
002183 ** then convert it into an TK_TRUEFALSE term. Return non-zero if
002184 ** the conversion happened, and zero if the expression is unaltered.
002185 */
002186 int sqlite3ExprIdToTrueFalse(Expr *pExpr){
002187 u32 v;
002188 assert( pExpr->op==TK_ID || pExpr->op==TK_STRING );
002189 if( !ExprHasProperty(pExpr, EP_Quoted|EP_IntValue)
002190 && (v = sqlite3IsTrueOrFalse(pExpr->u.zToken))!=0
002191 ){
002192 pExpr->op = TK_TRUEFALSE;
002193 ExprSetProperty(pExpr, v);
002194 return 1;
002195 }
002196 return 0;
002197 }
002198
002199 /*
002200 ** The argument must be a TK_TRUEFALSE Expr node. Return 1 if it is TRUE
002201 ** and 0 if it is FALSE.
002202 */
002203 int sqlite3ExprTruthValue(const Expr *pExpr){
002204 pExpr = sqlite3ExprSkipCollateAndLikely((Expr*)pExpr);
002205 assert( pExpr->op==TK_TRUEFALSE );
002206 assert( !ExprHasProperty(pExpr, EP_IntValue) );
002207 assert( sqlite3StrICmp(pExpr->u.zToken,"true")==0
002208 || sqlite3StrICmp(pExpr->u.zToken,"false")==0 );
002209 return pExpr->u.zToken[4]==0;
002210 }
002211
002212 /*
002213 ** If pExpr is an AND or OR expression, try to simplify it by eliminating
002214 ** terms that are always true or false. Return the simplified expression.
002215 ** Or return the original expression if no simplification is possible.
002216 **
002217 ** Examples:
002218 **
002219 ** (x<10) AND true => (x<10)
002220 ** (x<10) AND false => false
002221 ** (x<10) AND (y=22 OR false) => (x<10) AND (y=22)
002222 ** (x<10) AND (y=22 OR true) => (x<10)
002223 ** (y=22) OR true => true
002224 */
002225 Expr *sqlite3ExprSimplifiedAndOr(Expr *pExpr){
002226 assert( pExpr!=0 );
002227 if( pExpr->op==TK_AND || pExpr->op==TK_OR ){
002228 Expr *pRight = sqlite3ExprSimplifiedAndOr(pExpr->pRight);
002229 Expr *pLeft = sqlite3ExprSimplifiedAndOr(pExpr->pLeft);
002230 if( ExprAlwaysTrue(pLeft) || ExprAlwaysFalse(pRight) ){
002231 pExpr = pExpr->op==TK_AND ? pRight : pLeft;
002232 }else if( ExprAlwaysTrue(pRight) || ExprAlwaysFalse(pLeft) ){
002233 pExpr = pExpr->op==TK_AND ? pLeft : pRight;
002234 }
002235 }
002236 return pExpr;
002237 }
002238
002239
002240 /*
002241 ** These routines are Walker callbacks used to check expressions to
002242 ** see if they are "constant" for some definition of constant. The
002243 ** Walker.eCode value determines the type of "constant" we are looking
002244 ** for.
002245 **
002246 ** These callback routines are used to implement the following:
002247 **
002248 ** sqlite3ExprIsConstant() pWalker->eCode==1
002249 ** sqlite3ExprIsConstantNotJoin() pWalker->eCode==2
002250 ** sqlite3ExprIsTableConstant() pWalker->eCode==3
002251 ** sqlite3ExprIsConstantOrFunction() pWalker->eCode==4 or 5
002252 **
002253 ** In all cases, the callbacks set Walker.eCode=0 and abort if the expression
002254 ** is found to not be a constant.
002255 **
002256 ** The sqlite3ExprIsConstantOrFunction() is used for evaluating DEFAULT
002257 ** expressions in a CREATE TABLE statement. The Walker.eCode value is 5
002258 ** when parsing an existing schema out of the sqlite_schema table and 4
002259 ** when processing a new CREATE TABLE statement. A bound parameter raises
002260 ** an error for new statements, but is silently converted
002261 ** to NULL for existing schemas. This allows sqlite_schema tables that
002262 ** contain a bound parameter because they were generated by older versions
002263 ** of SQLite to be parsed by newer versions of SQLite without raising a
002264 ** malformed schema error.
002265 */
002266 static int exprNodeIsConstant(Walker *pWalker, Expr *pExpr){
002267
002268 /* If pWalker->eCode is 2 then any term of the expression that comes from
002269 ** the ON or USING clauses of an outer join disqualifies the expression
002270 ** from being considered constant. */
002271 if( pWalker->eCode==2 && ExprHasProperty(pExpr, EP_OuterON) ){
002272 pWalker->eCode = 0;
002273 return WRC_Abort;
002274 }
002275
002276 switch( pExpr->op ){
002277 /* Consider functions to be constant if all their arguments are constant
002278 ** and either pWalker->eCode==4 or 5 or the function has the
002279 ** SQLITE_FUNC_CONST flag. */
002280 case TK_FUNCTION:
002281 if( (pWalker->eCode>=4 || ExprHasProperty(pExpr,EP_ConstFunc))
002282 && !ExprHasProperty(pExpr, EP_WinFunc)
002283 ){
002284 if( pWalker->eCode==5 ) ExprSetProperty(pExpr, EP_FromDDL);
002285 return WRC_Continue;
002286 }else{
002287 pWalker->eCode = 0;
002288 return WRC_Abort;
002289 }
002290 case TK_ID:
002291 /* Convert "true" or "false" in a DEFAULT clause into the
002292 ** appropriate TK_TRUEFALSE operator */
002293 if( sqlite3ExprIdToTrueFalse(pExpr) ){
002294 return WRC_Prune;
002295 }
002296 /* no break */ deliberate_fall_through
002297 case TK_COLUMN:
002298 case TK_AGG_FUNCTION:
002299 case TK_AGG_COLUMN:
002300 testcase( pExpr->op==TK_ID );
002301 testcase( pExpr->op==TK_COLUMN );
002302 testcase( pExpr->op==TK_AGG_FUNCTION );
002303 testcase( pExpr->op==TK_AGG_COLUMN );
002304 if( ExprHasProperty(pExpr, EP_FixedCol) && pWalker->eCode!=2 ){
002305 return WRC_Continue;
002306 }
002307 if( pWalker->eCode==3 && pExpr->iTable==pWalker->u.iCur ){
002308 return WRC_Continue;
002309 }
002310 /* no break */ deliberate_fall_through
002311 case TK_IF_NULL_ROW:
002312 case TK_REGISTER:
002313 case TK_DOT:
002314 testcase( pExpr->op==TK_REGISTER );
002315 testcase( pExpr->op==TK_IF_NULL_ROW );
002316 testcase( pExpr->op==TK_DOT );
002317 pWalker->eCode = 0;
002318 return WRC_Abort;
002319 case TK_VARIABLE:
002320 if( pWalker->eCode==5 ){
002321 /* Silently convert bound parameters that appear inside of CREATE
002322 ** statements into a NULL when parsing the CREATE statement text out
002323 ** of the sqlite_schema table */
002324 pExpr->op = TK_NULL;
002325 }else if( pWalker->eCode==4 ){
002326 /* A bound parameter in a CREATE statement that originates from
002327 ** sqlite3_prepare() causes an error */
002328 pWalker->eCode = 0;
002329 return WRC_Abort;
002330 }
002331 /* no break */ deliberate_fall_through
002332 default:
002333 testcase( pExpr->op==TK_SELECT ); /* sqlite3SelectWalkFail() disallows */
002334 testcase( pExpr->op==TK_EXISTS ); /* sqlite3SelectWalkFail() disallows */
002335 return WRC_Continue;
002336 }
002337 }
002338 static int exprIsConst(Expr *p, int initFlag, int iCur){
002339 Walker w;
002340 w.eCode = initFlag;
002341 w.xExprCallback = exprNodeIsConstant;
002342 w.xSelectCallback = sqlite3SelectWalkFail;
002343 #ifdef SQLITE_DEBUG
002344 w.xSelectCallback2 = sqlite3SelectWalkAssert2;
002345 #endif
002346 w.u.iCur = iCur;
002347 sqlite3WalkExpr(&w, p);
002348 return w.eCode;
002349 }
002350
002351 /*
002352 ** Walk an expression tree. Return non-zero if the expression is constant
002353 ** and 0 if it involves variables or function calls.
002354 **
002355 ** For the purposes of this function, a double-quoted string (ex: "abc")
002356 ** is considered a variable but a single-quoted string (ex: 'abc') is
002357 ** a constant.
002358 */
002359 int sqlite3ExprIsConstant(Expr *p){
002360 return exprIsConst(p, 1, 0);
002361 }
002362
002363 /*
002364 ** Walk an expression tree. Return non-zero if
002365 **
002366 ** (1) the expression is constant, and
002367 ** (2) the expression does originate in the ON or USING clause
002368 ** of a LEFT JOIN, and
002369 ** (3) the expression does not contain any EP_FixedCol TK_COLUMN
002370 ** operands created by the constant propagation optimization.
002371 **
002372 ** When this routine returns true, it indicates that the expression
002373 ** can be added to the pParse->pConstExpr list and evaluated once when
002374 ** the prepared statement starts up. See sqlite3ExprCodeRunJustOnce().
002375 */
002376 int sqlite3ExprIsConstantNotJoin(Expr *p){
002377 return exprIsConst(p, 2, 0);
002378 }
002379
002380 /*
002381 ** Walk an expression tree. Return non-zero if the expression is constant
002382 ** for any single row of the table with cursor iCur. In other words, the
002383 ** expression must not refer to any non-deterministic function nor any
002384 ** table other than iCur.
002385 */
002386 int sqlite3ExprIsTableConstant(Expr *p, int iCur){
002387 return exprIsConst(p, 3, iCur);
002388 }
002389
002390 /*
002391 ** Check pExpr to see if it is an constraint on the single data source
002392 ** pSrc = &pSrcList->a[iSrc]. In other words, check to see if pExpr
002393 ** constrains pSrc but does not depend on any other tables or data
002394 ** sources anywhere else in the query. Return true (non-zero) if pExpr
002395 ** is a constraint on pSrc only.
002396 **
002397 ** This is an optimization. False negatives will perhaps cause slower
002398 ** queries, but false positives will yield incorrect answers. So when in
002399 ** doubt, return 0.
002400 **
002401 ** To be an single-source constraint, the following must be true:
002402 **
002403 ** (1) pExpr cannot refer to any table other than pSrc->iCursor.
002404 **
002405 ** (2) pExpr cannot use subqueries or non-deterministic functions.
002406 **
002407 ** (3) pSrc cannot be part of the left operand for a RIGHT JOIN.
002408 ** (Is there some way to relax this constraint?)
002409 **
002410 ** (4) If pSrc is the right operand of a LEFT JOIN, then...
002411 ** (4a) pExpr must come from an ON clause..
002412 ** (4b) and specifically the ON clause associated with the LEFT JOIN.
002413 **
002414 ** (5) If pSrc is not the right operand of a LEFT JOIN or the left
002415 ** operand of a RIGHT JOIN, then pExpr must be from the WHERE
002416 ** clause, not an ON clause.
002417 **
002418 ** (6) Either:
002419 **
002420 ** (6a) pExpr does not originate in an ON or USING clause, or
002421 **
002422 ** (6b) The ON or USING clause from which pExpr is derived is
002423 ** not to the left of a RIGHT JOIN (or FULL JOIN).
002424 **
002425 ** Without this restriction, accepting pExpr as a single-table
002426 ** constraint might move the the ON/USING filter expression
002427 ** from the left side of a RIGHT JOIN over to the right side,
002428 ** which leads to incorrect answers. See also restriction (9)
002429 ** on push-down.
002430 */
002431 int sqlite3ExprIsSingleTableConstraint(
002432 Expr *pExpr, /* The constraint */
002433 const SrcList *pSrcList, /* Complete FROM clause */
002434 int iSrc /* Which element of pSrcList to use */
002435 ){
002436 const SrcItem *pSrc = &pSrcList->a[iSrc];
002437 if( pSrc->fg.jointype & JT_LTORJ ){
002438 return 0; /* rule (3) */
002439 }
002440 if( pSrc->fg.jointype & JT_LEFT ){
002441 if( !ExprHasProperty(pExpr, EP_OuterON) ) return 0; /* rule (4a) */
002442 if( pExpr->w.iJoin!=pSrc->iCursor ) return 0; /* rule (4b) */
002443 }else{
002444 if( ExprHasProperty(pExpr, EP_OuterON) ) return 0; /* rule (5) */
002445 }
002446 if( ExprHasProperty(pExpr, EP_OuterON|EP_InnerON) /* (6a) */
002447 && (pSrcList->a[0].fg.jointype & JT_LTORJ)!=0 /* Fast pre-test of (6b) */
002448 ){
002449 int jj;
002450 for(jj=0; jj<iSrc; jj++){
002451 if( pExpr->w.iJoin==pSrcList->a[jj].iCursor ){
002452 if( (pSrcList->a[jj].fg.jointype & JT_LTORJ)!=0 ){
002453 return 0; /* restriction (6) */
002454 }
002455 break;
002456 }
002457 }
002458 }
002459 return sqlite3ExprIsTableConstant(pExpr, pSrc->iCursor); /* rules (1), (2) */
002460 }
002461
002462
002463 /*
002464 ** sqlite3WalkExpr() callback used by sqlite3ExprIsConstantOrGroupBy().
002465 */
002466 static int exprNodeIsConstantOrGroupBy(Walker *pWalker, Expr *pExpr){
002467 ExprList *pGroupBy = pWalker->u.pGroupBy;
002468 int i;
002469
002470 /* Check if pExpr is identical to any GROUP BY term. If so, consider
002471 ** it constant. */
002472 for(i=0; i<pGroupBy->nExpr; i++){
002473 Expr *p = pGroupBy->a[i].pExpr;
002474 if( sqlite3ExprCompare(0, pExpr, p, -1)<2 ){
002475 CollSeq *pColl = sqlite3ExprNNCollSeq(pWalker->pParse, p);
002476 if( sqlite3IsBinary(pColl) ){
002477 return WRC_Prune;
002478 }
002479 }
002480 }
002481
002482 /* Check if pExpr is a sub-select. If so, consider it variable. */
002483 if( ExprUseXSelect(pExpr) ){
002484 pWalker->eCode = 0;
002485 return WRC_Abort;
002486 }
002487
002488 return exprNodeIsConstant(pWalker, pExpr);
002489 }
002490
002491 /*
002492 ** Walk the expression tree passed as the first argument. Return non-zero
002493 ** if the expression consists entirely of constants or copies of terms
002494 ** in pGroupBy that sort with the BINARY collation sequence.
002495 **
002496 ** This routine is used to determine if a term of the HAVING clause can
002497 ** be promoted into the WHERE clause. In order for such a promotion to work,
002498 ** the value of the HAVING clause term must be the same for all members of
002499 ** a "group". The requirement that the GROUP BY term must be BINARY
002500 ** assumes that no other collating sequence will have a finer-grained
002501 ** grouping than binary. In other words (A=B COLLATE binary) implies
002502 ** A=B in every other collating sequence. The requirement that the
002503 ** GROUP BY be BINARY is stricter than necessary. It would also work
002504 ** to promote HAVING clauses that use the same alternative collating
002505 ** sequence as the GROUP BY term, but that is much harder to check,
002506 ** alternative collating sequences are uncommon, and this is only an
002507 ** optimization, so we take the easy way out and simply require the
002508 ** GROUP BY to use the BINARY collating sequence.
002509 */
002510 int sqlite3ExprIsConstantOrGroupBy(Parse *pParse, Expr *p, ExprList *pGroupBy){
002511 Walker w;
002512 w.eCode = 1;
002513 w.xExprCallback = exprNodeIsConstantOrGroupBy;
002514 w.xSelectCallback = 0;
002515 w.u.pGroupBy = pGroupBy;
002516 w.pParse = pParse;
002517 sqlite3WalkExpr(&w, p);
002518 return w.eCode;
002519 }
002520
002521 /*
002522 ** Walk an expression tree for the DEFAULT field of a column definition
002523 ** in a CREATE TABLE statement. Return non-zero if the expression is
002524 ** acceptable for use as a DEFAULT. That is to say, return non-zero if
002525 ** the expression is constant or a function call with constant arguments.
002526 ** Return and 0 if there are any variables.
002527 **
002528 ** isInit is true when parsing from sqlite_schema. isInit is false when
002529 ** processing a new CREATE TABLE statement. When isInit is true, parameters
002530 ** (such as ? or $abc) in the expression are converted into NULL. When
002531 ** isInit is false, parameters raise an error. Parameters should not be
002532 ** allowed in a CREATE TABLE statement, but some legacy versions of SQLite
002533 ** allowed it, so we need to support it when reading sqlite_schema for
002534 ** backwards compatibility.
002535 **
002536 ** If isInit is true, set EP_FromDDL on every TK_FUNCTION node.
002537 **
002538 ** For the purposes of this function, a double-quoted string (ex: "abc")
002539 ** is considered a variable but a single-quoted string (ex: 'abc') is
002540 ** a constant.
002541 */
002542 int sqlite3ExprIsConstantOrFunction(Expr *p, u8 isInit){
002543 assert( isInit==0 || isInit==1 );
002544 return exprIsConst(p, 4+isInit, 0);
002545 }
002546
002547 #ifdef SQLITE_ENABLE_CURSOR_HINTS
002548 /*
002549 ** Walk an expression tree. Return 1 if the expression contains a
002550 ** subquery of some kind. Return 0 if there are no subqueries.
002551 */
002552 int sqlite3ExprContainsSubquery(Expr *p){
002553 Walker w;
002554 w.eCode = 1;
002555 w.xExprCallback = sqlite3ExprWalkNoop;
002556 w.xSelectCallback = sqlite3SelectWalkFail;
002557 #ifdef SQLITE_DEBUG
002558 w.xSelectCallback2 = sqlite3SelectWalkAssert2;
002559 #endif
002560 sqlite3WalkExpr(&w, p);
002561 return w.eCode==0;
002562 }
002563 #endif
002564
002565 /*
002566 ** If the expression p codes a constant integer that is small enough
002567 ** to fit in a 32-bit integer, return 1 and put the value of the integer
002568 ** in *pValue. If the expression is not an integer or if it is too big
002569 ** to fit in a signed 32-bit integer, return 0 and leave *pValue unchanged.
002570 */
002571 int sqlite3ExprIsInteger(const Expr *p, int *pValue){
002572 int rc = 0;
002573 if( NEVER(p==0) ) return 0; /* Used to only happen following on OOM */
002574
002575 /* If an expression is an integer literal that fits in a signed 32-bit
002576 ** integer, then the EP_IntValue flag will have already been set */
002577 assert( p->op!=TK_INTEGER || (p->flags & EP_IntValue)!=0
002578 || sqlite3GetInt32(p->u.zToken, &rc)==0 );
002579
002580 if( p->flags & EP_IntValue ){
002581 *pValue = p->u.iValue;
002582 return 1;
002583 }
002584 switch( p->op ){
002585 case TK_UPLUS: {
002586 rc = sqlite3ExprIsInteger(p->pLeft, pValue);
002587 break;
002588 }
002589 case TK_UMINUS: {
002590 int v = 0;
002591 if( sqlite3ExprIsInteger(p->pLeft, &v) ){
002592 assert( ((unsigned int)v)!=0x80000000 );
002593 *pValue = -v;
002594 rc = 1;
002595 }
002596 break;
002597 }
002598 default: break;
002599 }
002600 return rc;
002601 }
002602
002603 /*
002604 ** Return FALSE if there is no chance that the expression can be NULL.
002605 **
002606 ** If the expression might be NULL or if the expression is too complex
002607 ** to tell return TRUE.
002608 **
002609 ** This routine is used as an optimization, to skip OP_IsNull opcodes
002610 ** when we know that a value cannot be NULL. Hence, a false positive
002611 ** (returning TRUE when in fact the expression can never be NULL) might
002612 ** be a small performance hit but is otherwise harmless. On the other
002613 ** hand, a false negative (returning FALSE when the result could be NULL)
002614 ** will likely result in an incorrect answer. So when in doubt, return
002615 ** TRUE.
002616 */
002617 int sqlite3ExprCanBeNull(const Expr *p){
002618 u8 op;
002619 assert( p!=0 );
002620 while( p->op==TK_UPLUS || p->op==TK_UMINUS ){
002621 p = p->pLeft;
002622 assert( p!=0 );
002623 }
002624 op = p->op;
002625 if( op==TK_REGISTER ) op = p->op2;
002626 switch( op ){
002627 case TK_INTEGER:
002628 case TK_STRING:
002629 case TK_FLOAT:
002630 case TK_BLOB:
002631 return 0;
002632 case TK_COLUMN:
002633 assert( ExprUseYTab(p) );
002634 return ExprHasProperty(p, EP_CanBeNull) ||
002635 p->y.pTab==0 || /* Reference to column of index on expression */
002636 (p->iColumn>=0
002637 && p->y.pTab->aCol!=0 /* Possible due to prior error */
002638 && p->y.pTab->aCol[p->iColumn].notNull==0);
002639 default:
002640 return 1;
002641 }
002642 }
002643
002644 /*
002645 ** Return TRUE if the given expression is a constant which would be
002646 ** unchanged by OP_Affinity with the affinity given in the second
002647 ** argument.
002648 **
002649 ** This routine is used to determine if the OP_Affinity operation
002650 ** can be omitted. When in doubt return FALSE. A false negative
002651 ** is harmless. A false positive, however, can result in the wrong
002652 ** answer.
002653 */
002654 int sqlite3ExprNeedsNoAffinityChange(const Expr *p, char aff){
002655 u8 op;
002656 int unaryMinus = 0;
002657 if( aff==SQLITE_AFF_BLOB ) return 1;
002658 while( p->op==TK_UPLUS || p->op==TK_UMINUS ){
002659 if( p->op==TK_UMINUS ) unaryMinus = 1;
002660 p = p->pLeft;
002661 }
002662 op = p->op;
002663 if( op==TK_REGISTER ) op = p->op2;
002664 switch( op ){
002665 case TK_INTEGER: {
002666 return aff>=SQLITE_AFF_NUMERIC;
002667 }
002668 case TK_FLOAT: {
002669 return aff>=SQLITE_AFF_NUMERIC;
002670 }
002671 case TK_STRING: {
002672 return !unaryMinus && aff==SQLITE_AFF_TEXT;
002673 }
002674 case TK_BLOB: {
002675 return !unaryMinus;
002676 }
002677 case TK_COLUMN: {
002678 assert( p->iTable>=0 ); /* p cannot be part of a CHECK constraint */
002679 return aff>=SQLITE_AFF_NUMERIC && p->iColumn<0;
002680 }
002681 default: {
002682 return 0;
002683 }
002684 }
002685 }
002686
002687 /*
002688 ** Return TRUE if the given string is a row-id column name.
002689 */
002690 int sqlite3IsRowid(const char *z){
002691 if( sqlite3StrICmp(z, "_ROWID_")==0 ) return 1;
002692 if( sqlite3StrICmp(z, "ROWID")==0 ) return 1;
002693 if( sqlite3StrICmp(z, "OID")==0 ) return 1;
002694 return 0;
002695 }
002696
002697 /*
002698 ** pX is the RHS of an IN operator. If pX is a SELECT statement
002699 ** that can be simplified to a direct table access, then return
002700 ** a pointer to the SELECT statement. If pX is not a SELECT statement,
002701 ** or if the SELECT statement needs to be materialized into a transient
002702 ** table, then return NULL.
002703 */
002704 #ifndef SQLITE_OMIT_SUBQUERY
002705 static Select *isCandidateForInOpt(const Expr *pX){
002706 Select *p;
002707 SrcList *pSrc;
002708 ExprList *pEList;
002709 Table *pTab;
002710 int i;
002711 if( !ExprUseXSelect(pX) ) return 0; /* Not a subquery */
002712 if( ExprHasProperty(pX, EP_VarSelect) ) return 0; /* Correlated subq */
002713 p = pX->x.pSelect;
002714 if( p->pPrior ) return 0; /* Not a compound SELECT */
002715 if( p->selFlags & (SF_Distinct|SF_Aggregate) ){
002716 testcase( (p->selFlags & (SF_Distinct|SF_Aggregate))==SF_Distinct );
002717 testcase( (p->selFlags & (SF_Distinct|SF_Aggregate))==SF_Aggregate );
002718 return 0; /* No DISTINCT keyword and no aggregate functions */
002719 }
002720 assert( p->pGroupBy==0 ); /* Has no GROUP BY clause */
002721 if( p->pLimit ) return 0; /* Has no LIMIT clause */
002722 if( p->pWhere ) return 0; /* Has no WHERE clause */
002723 pSrc = p->pSrc;
002724 assert( pSrc!=0 );
002725 if( pSrc->nSrc!=1 ) return 0; /* Single term in FROM clause */
002726 if( pSrc->a[0].pSelect ) return 0; /* FROM is not a subquery or view */
002727 pTab = pSrc->a[0].pTab;
002728 assert( pTab!=0 );
002729 assert( !IsView(pTab) ); /* FROM clause is not a view */
002730 if( IsVirtual(pTab) ) return 0; /* FROM clause not a virtual table */
002731 pEList = p->pEList;
002732 assert( pEList!=0 );
002733 /* All SELECT results must be columns. */
002734 for(i=0; i<pEList->nExpr; i++){
002735 Expr *pRes = pEList->a[i].pExpr;
002736 if( pRes->op!=TK_COLUMN ) return 0;
002737 assert( pRes->iTable==pSrc->a[0].iCursor ); /* Not a correlated subquery */
002738 }
002739 return p;
002740 }
002741 #endif /* SQLITE_OMIT_SUBQUERY */
002742
002743 #ifndef SQLITE_OMIT_SUBQUERY
002744 /*
002745 ** Generate code that checks the left-most column of index table iCur to see if
002746 ** it contains any NULL entries. Cause the register at regHasNull to be set
002747 ** to a non-NULL value if iCur contains no NULLs. Cause register regHasNull
002748 ** to be set to NULL if iCur contains one or more NULL values.
002749 */
002750 static void sqlite3SetHasNullFlag(Vdbe *v, int iCur, int regHasNull){
002751 int addr1;
002752 sqlite3VdbeAddOp2(v, OP_Integer, 0, regHasNull);
002753 addr1 = sqlite3VdbeAddOp1(v, OP_Rewind, iCur); VdbeCoverage(v);
002754 sqlite3VdbeAddOp3(v, OP_Column, iCur, 0, regHasNull);
002755 sqlite3VdbeChangeP5(v, OPFLAG_TYPEOFARG);
002756 VdbeComment((v, "first_entry_in(%d)", iCur));
002757 sqlite3VdbeJumpHere(v, addr1);
002758 }
002759 #endif
002760
002761
002762 #ifndef SQLITE_OMIT_SUBQUERY
002763 /*
002764 ** The argument is an IN operator with a list (not a subquery) on the
002765 ** right-hand side. Return TRUE if that list is constant.
002766 */
002767 static int sqlite3InRhsIsConstant(Expr *pIn){
002768 Expr *pLHS;
002769 int res;
002770 assert( !ExprHasProperty(pIn, EP_xIsSelect) );
002771 pLHS = pIn->pLeft;
002772 pIn->pLeft = 0;
002773 res = sqlite3ExprIsConstant(pIn);
002774 pIn->pLeft = pLHS;
002775 return res;
002776 }
002777 #endif
002778
002779 /*
002780 ** This function is used by the implementation of the IN (...) operator.
002781 ** The pX parameter is the expression on the RHS of the IN operator, which
002782 ** might be either a list of expressions or a subquery.
002783 **
002784 ** The job of this routine is to find or create a b-tree object that can
002785 ** be used either to test for membership in the RHS set or to iterate through
002786 ** all members of the RHS set, skipping duplicates.
002787 **
002788 ** A cursor is opened on the b-tree object that is the RHS of the IN operator
002789 ** and the *piTab parameter is set to the index of that cursor.
002790 **
002791 ** The returned value of this function indicates the b-tree type, as follows:
002792 **
002793 ** IN_INDEX_ROWID - The cursor was opened on a database table.
002794 ** IN_INDEX_INDEX_ASC - The cursor was opened on an ascending index.
002795 ** IN_INDEX_INDEX_DESC - The cursor was opened on a descending index.
002796 ** IN_INDEX_EPH - The cursor was opened on a specially created and
002797 ** populated ephemeral table.
002798 ** IN_INDEX_NOOP - No cursor was allocated. The IN operator must be
002799 ** implemented as a sequence of comparisons.
002800 **
002801 ** An existing b-tree might be used if the RHS expression pX is a simple
002802 ** subquery such as:
002803 **
002804 ** SELECT <column1>, <column2>... FROM <table>
002805 **
002806 ** If the RHS of the IN operator is a list or a more complex subquery, then
002807 ** an ephemeral table might need to be generated from the RHS and then
002808 ** pX->iTable made to point to the ephemeral table instead of an
002809 ** existing table. In this case, the creation and initialization of the
002810 ** ephemeral table might be put inside of a subroutine, the EP_Subrtn flag
002811 ** will be set on pX and the pX->y.sub fields will be set to show where
002812 ** the subroutine is coded.
002813 **
002814 ** The inFlags parameter must contain, at a minimum, one of the bits
002815 ** IN_INDEX_MEMBERSHIP or IN_INDEX_LOOP but not both. If inFlags contains
002816 ** IN_INDEX_MEMBERSHIP, then the generated table will be used for a fast
002817 ** membership test. When the IN_INDEX_LOOP bit is set, the IN index will
002818 ** be used to loop over all values of the RHS of the IN operator.
002819 **
002820 ** When IN_INDEX_LOOP is used (and the b-tree will be used to iterate
002821 ** through the set members) then the b-tree must not contain duplicates.
002822 ** An ephemeral table will be created unless the selected columns are guaranteed
002823 ** to be unique - either because it is an INTEGER PRIMARY KEY or due to
002824 ** a UNIQUE constraint or index.
002825 **
002826 ** When IN_INDEX_MEMBERSHIP is used (and the b-tree will be used
002827 ** for fast set membership tests) then an ephemeral table must
002828 ** be used unless <columns> is a single INTEGER PRIMARY KEY column or an
002829 ** index can be found with the specified <columns> as its left-most.
002830 **
002831 ** If the IN_INDEX_NOOP_OK and IN_INDEX_MEMBERSHIP are both set and
002832 ** if the RHS of the IN operator is a list (not a subquery) then this
002833 ** routine might decide that creating an ephemeral b-tree for membership
002834 ** testing is too expensive and return IN_INDEX_NOOP. In that case, the
002835 ** calling routine should implement the IN operator using a sequence
002836 ** of Eq or Ne comparison operations.
002837 **
002838 ** When the b-tree is being used for membership tests, the calling function
002839 ** might need to know whether or not the RHS side of the IN operator
002840 ** contains a NULL. If prRhsHasNull is not a NULL pointer and
002841 ** if there is any chance that the (...) might contain a NULL value at
002842 ** runtime, then a register is allocated and the register number written
002843 ** to *prRhsHasNull. If there is no chance that the (...) contains a
002844 ** NULL value, then *prRhsHasNull is left unchanged.
002845 **
002846 ** If a register is allocated and its location stored in *prRhsHasNull, then
002847 ** the value in that register will be NULL if the b-tree contains one or more
002848 ** NULL values, and it will be some non-NULL value if the b-tree contains no
002849 ** NULL values.
002850 **
002851 ** If the aiMap parameter is not NULL, it must point to an array containing
002852 ** one element for each column returned by the SELECT statement on the RHS
002853 ** of the IN(...) operator. The i'th entry of the array is populated with the
002854 ** offset of the index column that matches the i'th column returned by the
002855 ** SELECT. For example, if the expression and selected index are:
002856 **
002857 ** (?,?,?) IN (SELECT a, b, c FROM t1)
002858 ** CREATE INDEX i1 ON t1(b, c, a);
002859 **
002860 ** then aiMap[] is populated with {2, 0, 1}.
002861 */
002862 #ifndef SQLITE_OMIT_SUBQUERY
002863 int sqlite3FindInIndex(
002864 Parse *pParse, /* Parsing context */
002865 Expr *pX, /* The IN expression */
002866 u32 inFlags, /* IN_INDEX_LOOP, _MEMBERSHIP, and/or _NOOP_OK */
002867 int *prRhsHasNull, /* Register holding NULL status. See notes */
002868 int *aiMap, /* Mapping from Index fields to RHS fields */
002869 int *piTab /* OUT: index to use */
002870 ){
002871 Select *p; /* SELECT to the right of IN operator */
002872 int eType = 0; /* Type of RHS table. IN_INDEX_* */
002873 int iTab; /* Cursor of the RHS table */
002874 int mustBeUnique; /* True if RHS must be unique */
002875 Vdbe *v = sqlite3GetVdbe(pParse); /* Virtual machine being coded */
002876
002877 assert( pX->op==TK_IN );
002878 mustBeUnique = (inFlags & IN_INDEX_LOOP)!=0;
002879 iTab = pParse->nTab++;
002880
002881 /* If the RHS of this IN(...) operator is a SELECT, and if it matters
002882 ** whether or not the SELECT result contains NULL values, check whether
002883 ** or not NULL is actually possible (it may not be, for example, due
002884 ** to NOT NULL constraints in the schema). If no NULL values are possible,
002885 ** set prRhsHasNull to 0 before continuing. */
002886 if( prRhsHasNull && ExprUseXSelect(pX) ){
002887 int i;
002888 ExprList *pEList = pX->x.pSelect->pEList;
002889 for(i=0; i<pEList->nExpr; i++){
002890 if( sqlite3ExprCanBeNull(pEList->a[i].pExpr) ) break;
002891 }
002892 if( i==pEList->nExpr ){
002893 prRhsHasNull = 0;
002894 }
002895 }
002896
002897 /* Check to see if an existing table or index can be used to
002898 ** satisfy the query. This is preferable to generating a new
002899 ** ephemeral table. */
002900 if( pParse->nErr==0 && (p = isCandidateForInOpt(pX))!=0 ){
002901 sqlite3 *db = pParse->db; /* Database connection */
002902 Table *pTab; /* Table <table>. */
002903 int iDb; /* Database idx for pTab */
002904 ExprList *pEList = p->pEList;
002905 int nExpr = pEList->nExpr;
002906
002907 assert( p->pEList!=0 ); /* Because of isCandidateForInOpt(p) */
002908 assert( p->pEList->a[0].pExpr!=0 ); /* Because of isCandidateForInOpt(p) */
002909 assert( p->pSrc!=0 ); /* Because of isCandidateForInOpt(p) */
002910 pTab = p->pSrc->a[0].pTab;
002911
002912 /* Code an OP_Transaction and OP_TableLock for <table>. */
002913 iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
002914 assert( iDb>=0 && iDb<SQLITE_MAX_DB );
002915 sqlite3CodeVerifySchema(pParse, iDb);
002916 sqlite3TableLock(pParse, iDb, pTab->tnum, 0, pTab->zName);
002917
002918 assert(v); /* sqlite3GetVdbe() has always been previously called */
002919 if( nExpr==1 && pEList->a[0].pExpr->iColumn<0 ){
002920 /* The "x IN (SELECT rowid FROM table)" case */
002921 int iAddr = sqlite3VdbeAddOp0(v, OP_Once);
002922 VdbeCoverage(v);
002923
002924 sqlite3OpenTable(pParse, iTab, iDb, pTab, OP_OpenRead);
002925 eType = IN_INDEX_ROWID;
002926 ExplainQueryPlan((pParse, 0,
002927 "USING ROWID SEARCH ON TABLE %s FOR IN-OPERATOR",pTab->zName));
002928 sqlite3VdbeJumpHere(v, iAddr);
002929 }else{
002930 Index *pIdx; /* Iterator variable */
002931 int affinity_ok = 1;
002932 int i;
002933
002934 /* Check that the affinity that will be used to perform each
002935 ** comparison is the same as the affinity of each column in table
002936 ** on the RHS of the IN operator. If it not, it is not possible to
002937 ** use any index of the RHS table. */
002938 for(i=0; i<nExpr && affinity_ok; i++){
002939 Expr *pLhs = sqlite3VectorFieldSubexpr(pX->pLeft, i);
002940 int iCol = pEList->a[i].pExpr->iColumn;
002941 char idxaff = sqlite3TableColumnAffinity(pTab,iCol); /* RHS table */
002942 char cmpaff = sqlite3CompareAffinity(pLhs, idxaff);
002943 testcase( cmpaff==SQLITE_AFF_BLOB );
002944 testcase( cmpaff==SQLITE_AFF_TEXT );
002945 switch( cmpaff ){
002946 case SQLITE_AFF_BLOB:
002947 break;
002948 case SQLITE_AFF_TEXT:
002949 /* sqlite3CompareAffinity() only returns TEXT if one side or the
002950 ** other has no affinity and the other side is TEXT. Hence,
002951 ** the only way for cmpaff to be TEXT is for idxaff to be TEXT
002952 ** and for the term on the LHS of the IN to have no affinity. */
002953 assert( idxaff==SQLITE_AFF_TEXT );
002954 break;
002955 default:
002956 affinity_ok = sqlite3IsNumericAffinity(idxaff);
002957 }
002958 }
002959
002960 if( affinity_ok ){
002961 /* Search for an existing index that will work for this IN operator */
002962 for(pIdx=pTab->pIndex; pIdx && eType==0; pIdx=pIdx->pNext){
002963 Bitmask colUsed; /* Columns of the index used */
002964 Bitmask mCol; /* Mask for the current column */
002965 if( pIdx->nColumn<nExpr ) continue;
002966 if( pIdx->pPartIdxWhere!=0 ) continue;
002967 /* Maximum nColumn is BMS-2, not BMS-1, so that we can compute
002968 ** BITMASK(nExpr) without overflowing */
002969 testcase( pIdx->nColumn==BMS-2 );
002970 testcase( pIdx->nColumn==BMS-1 );
002971 if( pIdx->nColumn>=BMS-1 ) continue;
002972 if( mustBeUnique ){
002973 if( pIdx->nKeyCol>nExpr
002974 ||(pIdx->nColumn>nExpr && !IsUniqueIndex(pIdx))
002975 ){
002976 continue; /* This index is not unique over the IN RHS columns */
002977 }
002978 }
002979
002980 colUsed = 0; /* Columns of index used so far */
002981 for(i=0; i<nExpr; i++){
002982 Expr *pLhs = sqlite3VectorFieldSubexpr(pX->pLeft, i);
002983 Expr *pRhs = pEList->a[i].pExpr;
002984 CollSeq *pReq = sqlite3BinaryCompareCollSeq(pParse, pLhs, pRhs);
002985 int j;
002986
002987 for(j=0; j<nExpr; j++){
002988 if( pIdx->aiColumn[j]!=pRhs->iColumn ) continue;
002989 assert( pIdx->azColl[j] );
002990 if( pReq!=0 && sqlite3StrICmp(pReq->zName, pIdx->azColl[j])!=0 ){
002991 continue;
002992 }
002993 break;
002994 }
002995 if( j==nExpr ) break;
002996 mCol = MASKBIT(j);
002997 if( mCol & colUsed ) break; /* Each column used only once */
002998 colUsed |= mCol;
002999 if( aiMap ) aiMap[i] = j;
003000 }
003001
003002 assert( i==nExpr || colUsed!=(MASKBIT(nExpr)-1) );
003003 if( colUsed==(MASKBIT(nExpr)-1) ){
003004 /* If we reach this point, that means the index pIdx is usable */
003005 int iAddr = sqlite3VdbeAddOp0(v, OP_Once); VdbeCoverage(v);
003006 ExplainQueryPlan((pParse, 0,
003007 "USING INDEX %s FOR IN-OPERATOR",pIdx->zName));
003008 sqlite3VdbeAddOp3(v, OP_OpenRead, iTab, pIdx->tnum, iDb);
003009 sqlite3VdbeSetP4KeyInfo(pParse, pIdx);
003010 VdbeComment((v, "%s", pIdx->zName));
003011 assert( IN_INDEX_INDEX_DESC == IN_INDEX_INDEX_ASC+1 );
003012 eType = IN_INDEX_INDEX_ASC + pIdx->aSortOrder[0];
003013
003014 if( prRhsHasNull ){
003015 #ifdef SQLITE_ENABLE_COLUMN_USED_MASK
003016 i64 mask = (1<<nExpr)-1;
003017 sqlite3VdbeAddOp4Dup8(v, OP_ColumnsUsed,
003018 iTab, 0, 0, (u8*)&mask, P4_INT64);
003019 #endif
003020 *prRhsHasNull = ++pParse->nMem;
003021 if( nExpr==1 ){
003022 sqlite3SetHasNullFlag(v, iTab, *prRhsHasNull);
003023 }
003024 }
003025 sqlite3VdbeJumpHere(v, iAddr);
003026 }
003027 } /* End loop over indexes */
003028 } /* End if( affinity_ok ) */
003029 } /* End if not an rowid index */
003030 } /* End attempt to optimize using an index */
003031
003032 /* If no preexisting index is available for the IN clause
003033 ** and IN_INDEX_NOOP is an allowed reply
003034 ** and the RHS of the IN operator is a list, not a subquery
003035 ** and the RHS is not constant or has two or fewer terms,
003036 ** then it is not worth creating an ephemeral table to evaluate
003037 ** the IN operator so return IN_INDEX_NOOP.
003038 */
003039 if( eType==0
003040 && (inFlags & IN_INDEX_NOOP_OK)
003041 && ExprUseXList(pX)
003042 && (!sqlite3InRhsIsConstant(pX) || pX->x.pList->nExpr<=2)
003043 ){
003044 pParse->nTab--; /* Back out the allocation of the unused cursor */
003045 iTab = -1; /* Cursor is not allocated */
003046 eType = IN_INDEX_NOOP;
003047 }
003048
003049 if( eType==0 ){
003050 /* Could not find an existing table or index to use as the RHS b-tree.
003051 ** We will have to generate an ephemeral table to do the job.
003052 */
003053 u32 savedNQueryLoop = pParse->nQueryLoop;
003054 int rMayHaveNull = 0;
003055 eType = IN_INDEX_EPH;
003056 if( inFlags & IN_INDEX_LOOP ){
003057 pParse->nQueryLoop = 0;
003058 }else if( prRhsHasNull ){
003059 *prRhsHasNull = rMayHaveNull = ++pParse->nMem;
003060 }
003061 assert( pX->op==TK_IN );
003062 sqlite3CodeRhsOfIN(pParse, pX, iTab);
003063 if( rMayHaveNull ){
003064 sqlite3SetHasNullFlag(v, iTab, rMayHaveNull);
003065 }
003066 pParse->nQueryLoop = savedNQueryLoop;
003067 }
003068
003069 if( aiMap && eType!=IN_INDEX_INDEX_ASC && eType!=IN_INDEX_INDEX_DESC ){
003070 int i, n;
003071 n = sqlite3ExprVectorSize(pX->pLeft);
003072 for(i=0; i<n; i++) aiMap[i] = i;
003073 }
003074 *piTab = iTab;
003075 return eType;
003076 }
003077 #endif
003078
003079 #ifndef SQLITE_OMIT_SUBQUERY
003080 /*
003081 ** Argument pExpr is an (?, ?...) IN(...) expression. This
003082 ** function allocates and returns a nul-terminated string containing
003083 ** the affinities to be used for each column of the comparison.
003084 **
003085 ** It is the responsibility of the caller to ensure that the returned
003086 ** string is eventually freed using sqlite3DbFree().
003087 */
003088 static char *exprINAffinity(Parse *pParse, const Expr *pExpr){
003089 Expr *pLeft = pExpr->pLeft;
003090 int nVal = sqlite3ExprVectorSize(pLeft);
003091 Select *pSelect = ExprUseXSelect(pExpr) ? pExpr->x.pSelect : 0;
003092 char *zRet;
003093
003094 assert( pExpr->op==TK_IN );
003095 zRet = sqlite3DbMallocRaw(pParse->db, nVal+1);
003096 if( zRet ){
003097 int i;
003098 for(i=0; i<nVal; i++){
003099 Expr *pA = sqlite3VectorFieldSubexpr(pLeft, i);
003100 char a = sqlite3ExprAffinity(pA);
003101 if( pSelect ){
003102 zRet[i] = sqlite3CompareAffinity(pSelect->pEList->a[i].pExpr, a);
003103 }else{
003104 zRet[i] = a;
003105 }
003106 }
003107 zRet[nVal] = '\0';
003108 }
003109 return zRet;
003110 }
003111 #endif
003112
003113 #ifndef SQLITE_OMIT_SUBQUERY
003114 /*
003115 ** Load the Parse object passed as the first argument with an error
003116 ** message of the form:
003117 **
003118 ** "sub-select returns N columns - expected M"
003119 */
003120 void sqlite3SubselectError(Parse *pParse, int nActual, int nExpect){
003121 if( pParse->nErr==0 ){
003122 const char *zFmt = "sub-select returns %d columns - expected %d";
003123 sqlite3ErrorMsg(pParse, zFmt, nActual, nExpect);
003124 }
003125 }
003126 #endif
003127
003128 /*
003129 ** Expression pExpr is a vector that has been used in a context where
003130 ** it is not permitted. If pExpr is a sub-select vector, this routine
003131 ** loads the Parse object with a message of the form:
003132 **
003133 ** "sub-select returns N columns - expected 1"
003134 **
003135 ** Or, if it is a regular scalar vector:
003136 **
003137 ** "row value misused"
003138 */
003139 void sqlite3VectorErrorMsg(Parse *pParse, Expr *pExpr){
003140 #ifndef SQLITE_OMIT_SUBQUERY
003141 if( ExprUseXSelect(pExpr) ){
003142 sqlite3SubselectError(pParse, pExpr->x.pSelect->pEList->nExpr, 1);
003143 }else
003144 #endif
003145 {
003146 sqlite3ErrorMsg(pParse, "row value misused");
003147 }
003148 }
003149
003150 #ifndef SQLITE_OMIT_SUBQUERY
003151 /*
003152 ** Generate code that will construct an ephemeral table containing all terms
003153 ** in the RHS of an IN operator. The IN operator can be in either of two
003154 ** forms:
003155 **
003156 ** x IN (4,5,11) -- IN operator with list on right-hand side
003157 ** x IN (SELECT a FROM b) -- IN operator with subquery on the right
003158 **
003159 ** The pExpr parameter is the IN operator. The cursor number for the
003160 ** constructed ephemeral table is returned. The first time the ephemeral
003161 ** table is computed, the cursor number is also stored in pExpr->iTable,
003162 ** however the cursor number returned might not be the same, as it might
003163 ** have been duplicated using OP_OpenDup.
003164 **
003165 ** If the LHS expression ("x" in the examples) is a column value, or
003166 ** the SELECT statement returns a column value, then the affinity of that
003167 ** column is used to build the index keys. If both 'x' and the
003168 ** SELECT... statement are columns, then numeric affinity is used
003169 ** if either column has NUMERIC or INTEGER affinity. If neither
003170 ** 'x' nor the SELECT... statement are columns, then numeric affinity
003171 ** is used.
003172 */
003173 void sqlite3CodeRhsOfIN(
003174 Parse *pParse, /* Parsing context */
003175 Expr *pExpr, /* The IN operator */
003176 int iTab /* Use this cursor number */
003177 ){
003178 int addrOnce = 0; /* Address of the OP_Once instruction at top */
003179 int addr; /* Address of OP_OpenEphemeral instruction */
003180 Expr *pLeft; /* the LHS of the IN operator */
003181 KeyInfo *pKeyInfo = 0; /* Key information */
003182 int nVal; /* Size of vector pLeft */
003183 Vdbe *v; /* The prepared statement under construction */
003184
003185 v = pParse->pVdbe;
003186 assert( v!=0 );
003187
003188 /* The evaluation of the IN must be repeated every time it
003189 ** is encountered if any of the following is true:
003190 **
003191 ** * The right-hand side is a correlated subquery
003192 ** * The right-hand side is an expression list containing variables
003193 ** * We are inside a trigger
003194 **
003195 ** If all of the above are false, then we can compute the RHS just once
003196 ** and reuse it many names.
003197 */
003198 if( !ExprHasProperty(pExpr, EP_VarSelect) && pParse->iSelfTab==0 ){
003199 /* Reuse of the RHS is allowed */
003200 /* If this routine has already been coded, but the previous code
003201 ** might not have been invoked yet, so invoke it now as a subroutine.
003202 */
003203 if( ExprHasProperty(pExpr, EP_Subrtn) ){
003204 addrOnce = sqlite3VdbeAddOp0(v, OP_Once); VdbeCoverage(v);
003205 if( ExprUseXSelect(pExpr) ){
003206 ExplainQueryPlan((pParse, 0, "REUSE LIST SUBQUERY %d",
003207 pExpr->x.pSelect->selId));
003208 }
003209 assert( ExprUseYSub(pExpr) );
003210 sqlite3VdbeAddOp2(v, OP_Gosub, pExpr->y.sub.regReturn,
003211 pExpr->y.sub.iAddr);
003212 assert( iTab!=pExpr->iTable );
003213 sqlite3VdbeAddOp2(v, OP_OpenDup, iTab, pExpr->iTable);
003214 sqlite3VdbeJumpHere(v, addrOnce);
003215 return;
003216 }
003217
003218 /* Begin coding the subroutine */
003219 assert( !ExprUseYWin(pExpr) );
003220 ExprSetProperty(pExpr, EP_Subrtn);
003221 assert( !ExprHasProperty(pExpr, EP_TokenOnly|EP_Reduced) );
003222 pExpr->y.sub.regReturn = ++pParse->nMem;
003223 pExpr->y.sub.iAddr =
003224 sqlite3VdbeAddOp2(v, OP_BeginSubrtn, 0, pExpr->y.sub.regReturn) + 1;
003225
003226 addrOnce = sqlite3VdbeAddOp0(v, OP_Once); VdbeCoverage(v);
003227 }
003228
003229 /* Check to see if this is a vector IN operator */
003230 pLeft = pExpr->pLeft;
003231 nVal = sqlite3ExprVectorSize(pLeft);
003232
003233 /* Construct the ephemeral table that will contain the content of
003234 ** RHS of the IN operator.
003235 */
003236 pExpr->iTable = iTab;
003237 addr = sqlite3VdbeAddOp2(v, OP_OpenEphemeral, pExpr->iTable, nVal);
003238 #ifdef SQLITE_ENABLE_EXPLAIN_COMMENTS
003239 if( ExprUseXSelect(pExpr) ){
003240 VdbeComment((v, "Result of SELECT %u", pExpr->x.pSelect->selId));
003241 }else{
003242 VdbeComment((v, "RHS of IN operator"));
003243 }
003244 #endif
003245 pKeyInfo = sqlite3KeyInfoAlloc(pParse->db, nVal, 1);
003246
003247 if( ExprUseXSelect(pExpr) ){
003248 /* Case 1: expr IN (SELECT ...)
003249 **
003250 ** Generate code to write the results of the select into the temporary
003251 ** table allocated and opened above.
003252 */
003253 Select *pSelect = pExpr->x.pSelect;
003254 ExprList *pEList = pSelect->pEList;
003255
003256 ExplainQueryPlan((pParse, 1, "%sLIST SUBQUERY %d",
003257 addrOnce?"":"CORRELATED ", pSelect->selId
003258 ));
003259 /* If the LHS and RHS of the IN operator do not match, that
003260 ** error will have been caught long before we reach this point. */
003261 if( ALWAYS(pEList->nExpr==nVal) ){
003262 Select *pCopy;
003263 SelectDest dest;
003264 int i;
003265 int rc;
003266 sqlite3SelectDestInit(&dest, SRT_Set, iTab);
003267 dest.zAffSdst = exprINAffinity(pParse, pExpr);
003268 pSelect->iLimit = 0;
003269 testcase( pSelect->selFlags & SF_Distinct );
003270 testcase( pKeyInfo==0 ); /* Caused by OOM in sqlite3KeyInfoAlloc() */
003271 pCopy = sqlite3SelectDup(pParse->db, pSelect, 0);
003272 rc = pParse->db->mallocFailed ? 1 :sqlite3Select(pParse, pCopy, &dest);
003273 sqlite3SelectDelete(pParse->db, pCopy);
003274 sqlite3DbFree(pParse->db, dest.zAffSdst);
003275 if( rc ){
003276 sqlite3KeyInfoUnref(pKeyInfo);
003277 return;
003278 }
003279 assert( pKeyInfo!=0 ); /* OOM will cause exit after sqlite3Select() */
003280 assert( pEList!=0 );
003281 assert( pEList->nExpr>0 );
003282 assert( sqlite3KeyInfoIsWriteable(pKeyInfo) );
003283 for(i=0; i<nVal; i++){
003284 Expr *p = sqlite3VectorFieldSubexpr(pLeft, i);
003285 pKeyInfo->aColl[i] = sqlite3BinaryCompareCollSeq(
003286 pParse, p, pEList->a[i].pExpr
003287 );
003288 }
003289 }
003290 }else if( ALWAYS(pExpr->x.pList!=0) ){
003291 /* Case 2: expr IN (exprlist)
003292 **
003293 ** For each expression, build an index key from the evaluation and
003294 ** store it in the temporary table. If <expr> is a column, then use
003295 ** that columns affinity when building index keys. If <expr> is not
003296 ** a column, use numeric affinity.
003297 */
003298 char affinity; /* Affinity of the LHS of the IN */
003299 int i;
003300 ExprList *pList = pExpr->x.pList;
003301 struct ExprList_item *pItem;
003302 int r1, r2;
003303 affinity = sqlite3ExprAffinity(pLeft);
003304 if( affinity<=SQLITE_AFF_NONE ){
003305 affinity = SQLITE_AFF_BLOB;
003306 }else if( affinity==SQLITE_AFF_REAL ){
003307 affinity = SQLITE_AFF_NUMERIC;
003308 }
003309 if( pKeyInfo ){
003310 assert( sqlite3KeyInfoIsWriteable(pKeyInfo) );
003311 pKeyInfo->aColl[0] = sqlite3ExprCollSeq(pParse, pExpr->pLeft);
003312 }
003313
003314 /* Loop through each expression in <exprlist>. */
003315 r1 = sqlite3GetTempReg(pParse);
003316 r2 = sqlite3GetTempReg(pParse);
003317 for(i=pList->nExpr, pItem=pList->a; i>0; i--, pItem++){
003318 Expr *pE2 = pItem->pExpr;
003319
003320 /* If the expression is not constant then we will need to
003321 ** disable the test that was generated above that makes sure
003322 ** this code only executes once. Because for a non-constant
003323 ** expression we need to rerun this code each time.
003324 */
003325 if( addrOnce && !sqlite3ExprIsConstant(pE2) ){
003326 sqlite3VdbeChangeToNoop(v, addrOnce-1);
003327 sqlite3VdbeChangeToNoop(v, addrOnce);
003328 ExprClearProperty(pExpr, EP_Subrtn);
003329 addrOnce = 0;
003330 }
003331
003332 /* Evaluate the expression and insert it into the temp table */
003333 sqlite3ExprCode(pParse, pE2, r1);
003334 sqlite3VdbeAddOp4(v, OP_MakeRecord, r1, 1, r2, &affinity, 1);
003335 sqlite3VdbeAddOp4Int(v, OP_IdxInsert, iTab, r2, r1, 1);
003336 }
003337 sqlite3ReleaseTempReg(pParse, r1);
003338 sqlite3ReleaseTempReg(pParse, r2);
003339 }
003340 if( pKeyInfo ){
003341 sqlite3VdbeChangeP4(v, addr, (void *)pKeyInfo, P4_KEYINFO);
003342 }
003343 if( addrOnce ){
003344 sqlite3VdbeAddOp1(v, OP_NullRow, iTab);
003345 sqlite3VdbeJumpHere(v, addrOnce);
003346 /* Subroutine return */
003347 assert( ExprUseYSub(pExpr) );
003348 assert( sqlite3VdbeGetOp(v,pExpr->y.sub.iAddr-1)->opcode==OP_BeginSubrtn
003349 || pParse->nErr );
003350 sqlite3VdbeAddOp3(v, OP_Return, pExpr->y.sub.regReturn,
003351 pExpr->y.sub.iAddr, 1);
003352 VdbeCoverage(v);
003353 sqlite3ClearTempRegCache(pParse);
003354 }
003355 }
003356 #endif /* SQLITE_OMIT_SUBQUERY */
003357
003358 /*
003359 ** Generate code for scalar subqueries used as a subquery expression
003360 ** or EXISTS operator:
003361 **
003362 ** (SELECT a FROM b) -- subquery
003363 ** EXISTS (SELECT a FROM b) -- EXISTS subquery
003364 **
003365 ** The pExpr parameter is the SELECT or EXISTS operator to be coded.
003366 **
003367 ** Return the register that holds the result. For a multi-column SELECT,
003368 ** the result is stored in a contiguous array of registers and the
003369 ** return value is the register of the left-most result column.
003370 ** Return 0 if an error occurs.
003371 */
003372 #ifndef SQLITE_OMIT_SUBQUERY
003373 int sqlite3CodeSubselect(Parse *pParse, Expr *pExpr){
003374 int addrOnce = 0; /* Address of OP_Once at top of subroutine */
003375 int rReg = 0; /* Register storing resulting */
003376 Select *pSel; /* SELECT statement to encode */
003377 SelectDest dest; /* How to deal with SELECT result */
003378 int nReg; /* Registers to allocate */
003379 Expr *pLimit; /* New limit expression */
003380 #ifdef SQLITE_ENABLE_STMT_SCANSTATUS
003381 int addrExplain; /* Address of OP_Explain instruction */
003382 #endif
003383
003384 Vdbe *v = pParse->pVdbe;
003385 assert( v!=0 );
003386 if( pParse->nErr ) return 0;
003387 testcase( pExpr->op==TK_EXISTS );
003388 testcase( pExpr->op==TK_SELECT );
003389 assert( pExpr->op==TK_EXISTS || pExpr->op==TK_SELECT );
003390 assert( ExprUseXSelect(pExpr) );
003391 pSel = pExpr->x.pSelect;
003392
003393 /* If this routine has already been coded, then invoke it as a
003394 ** subroutine. */
003395 if( ExprHasProperty(pExpr, EP_Subrtn) ){
003396 ExplainQueryPlan((pParse, 0, "REUSE SUBQUERY %d", pSel->selId));
003397 assert( ExprUseYSub(pExpr) );
003398 sqlite3VdbeAddOp2(v, OP_Gosub, pExpr->y.sub.regReturn,
003399 pExpr->y.sub.iAddr);
003400 return pExpr->iTable;
003401 }
003402
003403 /* Begin coding the subroutine */
003404 assert( !ExprUseYWin(pExpr) );
003405 assert( !ExprHasProperty(pExpr, EP_Reduced|EP_TokenOnly) );
003406 ExprSetProperty(pExpr, EP_Subrtn);
003407 pExpr->y.sub.regReturn = ++pParse->nMem;
003408 pExpr->y.sub.iAddr =
003409 sqlite3VdbeAddOp2(v, OP_BeginSubrtn, 0, pExpr->y.sub.regReturn) + 1;
003410
003411 /* The evaluation of the EXISTS/SELECT must be repeated every time it
003412 ** is encountered if any of the following is true:
003413 **
003414 ** * The right-hand side is a correlated subquery
003415 ** * The right-hand side is an expression list containing variables
003416 ** * We are inside a trigger
003417 **
003418 ** If all of the above are false, then we can run this code just once
003419 ** save the results, and reuse the same result on subsequent invocations.
003420 */
003421 if( !ExprHasProperty(pExpr, EP_VarSelect) ){
003422 addrOnce = sqlite3VdbeAddOp0(v, OP_Once); VdbeCoverage(v);
003423 }
003424
003425 /* For a SELECT, generate code to put the values for all columns of
003426 ** the first row into an array of registers and return the index of
003427 ** the first register.
003428 **
003429 ** If this is an EXISTS, write an integer 0 (not exists) or 1 (exists)
003430 ** into a register and return that register number.
003431 **
003432 ** In both cases, the query is augmented with "LIMIT 1". Any
003433 ** preexisting limit is discarded in place of the new LIMIT 1.
003434 */
003435 ExplainQueryPlan2(addrExplain, (pParse, 1, "%sSCALAR SUBQUERY %d",
003436 addrOnce?"":"CORRELATED ", pSel->selId));
003437 sqlite3VdbeScanStatusCounters(v, addrExplain, addrExplain, -1);
003438 nReg = pExpr->op==TK_SELECT ? pSel->pEList->nExpr : 1;
003439 sqlite3SelectDestInit(&dest, 0, pParse->nMem+1);
003440 pParse->nMem += nReg;
003441 if( pExpr->op==TK_SELECT ){
003442 dest.eDest = SRT_Mem;
003443 dest.iSdst = dest.iSDParm;
003444 dest.nSdst = nReg;
003445 sqlite3VdbeAddOp3(v, OP_Null, 0, dest.iSDParm, dest.iSDParm+nReg-1);
003446 VdbeComment((v, "Init subquery result"));
003447 }else{
003448 dest.eDest = SRT_Exists;
003449 sqlite3VdbeAddOp2(v, OP_Integer, 0, dest.iSDParm);
003450 VdbeComment((v, "Init EXISTS result"));
003451 }
003452 if( pSel->pLimit ){
003453 /* The subquery already has a limit. If the pre-existing limit is X
003454 ** then make the new limit X<>0 so that the new limit is either 1 or 0 */
003455 sqlite3 *db = pParse->db;
003456 pLimit = sqlite3Expr(db, TK_INTEGER, "0");
003457 if( pLimit ){
003458 pLimit->affExpr = SQLITE_AFF_NUMERIC;
003459 pLimit = sqlite3PExpr(pParse, TK_NE,
003460 sqlite3ExprDup(db, pSel->pLimit->pLeft, 0), pLimit);
003461 }
003462 sqlite3ExprDeferredDelete(pParse, pSel->pLimit->pLeft);
003463 pSel->pLimit->pLeft = pLimit;
003464 }else{
003465 /* If there is no pre-existing limit add a limit of 1 */
003466 pLimit = sqlite3Expr(pParse->db, TK_INTEGER, "1");
003467 pSel->pLimit = sqlite3PExpr(pParse, TK_LIMIT, pLimit, 0);
003468 }
003469 pSel->iLimit = 0;
003470 if( sqlite3Select(pParse, pSel, &dest) ){
003471 pExpr->op2 = pExpr->op;
003472 pExpr->op = TK_ERROR;
003473 return 0;
003474 }
003475 pExpr->iTable = rReg = dest.iSDParm;
003476 ExprSetVVAProperty(pExpr, EP_NoReduce);
003477 if( addrOnce ){
003478 sqlite3VdbeJumpHere(v, addrOnce);
003479 }
003480 sqlite3VdbeScanStatusRange(v, addrExplain, addrExplain, -1);
003481
003482 /* Subroutine return */
003483 assert( ExprUseYSub(pExpr) );
003484 assert( sqlite3VdbeGetOp(v,pExpr->y.sub.iAddr-1)->opcode==OP_BeginSubrtn
003485 || pParse->nErr );
003486 sqlite3VdbeAddOp3(v, OP_Return, pExpr->y.sub.regReturn,
003487 pExpr->y.sub.iAddr, 1);
003488 VdbeCoverage(v);
003489 sqlite3ClearTempRegCache(pParse);
003490 return rReg;
003491 }
003492 #endif /* SQLITE_OMIT_SUBQUERY */
003493
003494 #ifndef SQLITE_OMIT_SUBQUERY
003495 /*
003496 ** Expr pIn is an IN(...) expression. This function checks that the
003497 ** sub-select on the RHS of the IN() operator has the same number of
003498 ** columns as the vector on the LHS. Or, if the RHS of the IN() is not
003499 ** a sub-query, that the LHS is a vector of size 1.
003500 */
003501 int sqlite3ExprCheckIN(Parse *pParse, Expr *pIn){
003502 int nVector = sqlite3ExprVectorSize(pIn->pLeft);
003503 if( ExprUseXSelect(pIn) && !pParse->db->mallocFailed ){
003504 if( nVector!=pIn->x.pSelect->pEList->nExpr ){
003505 sqlite3SubselectError(pParse, pIn->x.pSelect->pEList->nExpr, nVector);
003506 return 1;
003507 }
003508 }else if( nVector!=1 ){
003509 sqlite3VectorErrorMsg(pParse, pIn->pLeft);
003510 return 1;
003511 }
003512 return 0;
003513 }
003514 #endif
003515
003516 #ifndef SQLITE_OMIT_SUBQUERY
003517 /*
003518 ** Generate code for an IN expression.
003519 **
003520 ** x IN (SELECT ...)
003521 ** x IN (value, value, ...)
003522 **
003523 ** The left-hand side (LHS) is a scalar or vector expression. The
003524 ** right-hand side (RHS) is an array of zero or more scalar values, or a
003525 ** subquery. If the RHS is a subquery, the number of result columns must
003526 ** match the number of columns in the vector on the LHS. If the RHS is
003527 ** a list of values, the LHS must be a scalar.
003528 **
003529 ** The IN operator is true if the LHS value is contained within the RHS.
003530 ** The result is false if the LHS is definitely not in the RHS. The
003531 ** result is NULL if the presence of the LHS in the RHS cannot be
003532 ** determined due to NULLs.
003533 **
003534 ** This routine generates code that jumps to destIfFalse if the LHS is not
003535 ** contained within the RHS. If due to NULLs we cannot determine if the LHS
003536 ** is contained in the RHS then jump to destIfNull. If the LHS is contained
003537 ** within the RHS then fall through.
003538 **
003539 ** See the separate in-operator.md documentation file in the canonical
003540 ** SQLite source tree for additional information.
003541 */
003542 static void sqlite3ExprCodeIN(
003543 Parse *pParse, /* Parsing and code generating context */
003544 Expr *pExpr, /* The IN expression */
003545 int destIfFalse, /* Jump here if LHS is not contained in the RHS */
003546 int destIfNull /* Jump here if the results are unknown due to NULLs */
003547 ){
003548 int rRhsHasNull = 0; /* Register that is true if RHS contains NULL values */
003549 int eType; /* Type of the RHS */
003550 int rLhs; /* Register(s) holding the LHS values */
003551 int rLhsOrig; /* LHS values prior to reordering by aiMap[] */
003552 Vdbe *v; /* Statement under construction */
003553 int *aiMap = 0; /* Map from vector field to index column */
003554 char *zAff = 0; /* Affinity string for comparisons */
003555 int nVector; /* Size of vectors for this IN operator */
003556 int iDummy; /* Dummy parameter to exprCodeVector() */
003557 Expr *pLeft; /* The LHS of the IN operator */
003558 int i; /* loop counter */
003559 int destStep2; /* Where to jump when NULLs seen in step 2 */
003560 int destStep6 = 0; /* Start of code for Step 6 */
003561 int addrTruthOp; /* Address of opcode that determines the IN is true */
003562 int destNotNull; /* Jump here if a comparison is not true in step 6 */
003563 int addrTop; /* Top of the step-6 loop */
003564 int iTab = 0; /* Index to use */
003565 u8 okConstFactor = pParse->okConstFactor;
003566
003567 assert( !ExprHasVVAProperty(pExpr,EP_Immutable) );
003568 pLeft = pExpr->pLeft;
003569 if( sqlite3ExprCheckIN(pParse, pExpr) ) return;
003570 zAff = exprINAffinity(pParse, pExpr);
003571 nVector = sqlite3ExprVectorSize(pExpr->pLeft);
003572 aiMap = (int*)sqlite3DbMallocZero(
003573 pParse->db, nVector*(sizeof(int) + sizeof(char)) + 1
003574 );
003575 if( pParse->db->mallocFailed ) goto sqlite3ExprCodeIN_oom_error;
003576
003577 /* Attempt to compute the RHS. After this step, if anything other than
003578 ** IN_INDEX_NOOP is returned, the table opened with cursor iTab
003579 ** contains the values that make up the RHS. If IN_INDEX_NOOP is returned,
003580 ** the RHS has not yet been coded. */
003581 v = pParse->pVdbe;
003582 assert( v!=0 ); /* OOM detected prior to this routine */
003583 VdbeNoopComment((v, "begin IN expr"));
003584 eType = sqlite3FindInIndex(pParse, pExpr,
003585 IN_INDEX_MEMBERSHIP | IN_INDEX_NOOP_OK,
003586 destIfFalse==destIfNull ? 0 : &rRhsHasNull,
003587 aiMap, &iTab);
003588
003589 assert( pParse->nErr || nVector==1 || eType==IN_INDEX_EPH
003590 || eType==IN_INDEX_INDEX_ASC || eType==IN_INDEX_INDEX_DESC
003591 );
003592 #ifdef SQLITE_DEBUG
003593 /* Confirm that aiMap[] contains nVector integer values between 0 and
003594 ** nVector-1. */
003595 for(i=0; i<nVector; i++){
003596 int j, cnt;
003597 for(cnt=j=0; j<nVector; j++) if( aiMap[j]==i ) cnt++;
003598 assert( cnt==1 );
003599 }
003600 #endif
003601
003602 /* Code the LHS, the <expr> from "<expr> IN (...)". If the LHS is a
003603 ** vector, then it is stored in an array of nVector registers starting
003604 ** at r1.
003605 **
003606 ** sqlite3FindInIndex() might have reordered the fields of the LHS vector
003607 ** so that the fields are in the same order as an existing index. The
003608 ** aiMap[] array contains a mapping from the original LHS field order to
003609 ** the field order that matches the RHS index.
003610 **
003611 ** Avoid factoring the LHS of the IN(...) expression out of the loop,
003612 ** even if it is constant, as OP_Affinity may be used on the register
003613 ** by code generated below. */
003614 assert( pParse->okConstFactor==okConstFactor );
003615 pParse->okConstFactor = 0;
003616 rLhsOrig = exprCodeVector(pParse, pLeft, &iDummy);
003617 pParse->okConstFactor = okConstFactor;
003618 for(i=0; i<nVector && aiMap[i]==i; i++){} /* Are LHS fields reordered? */
003619 if( i==nVector ){
003620 /* LHS fields are not reordered */
003621 rLhs = rLhsOrig;
003622 }else{
003623 /* Need to reorder the LHS fields according to aiMap */
003624 rLhs = sqlite3GetTempRange(pParse, nVector);
003625 for(i=0; i<nVector; i++){
003626 sqlite3VdbeAddOp3(v, OP_Copy, rLhsOrig+i, rLhs+aiMap[i], 0);
003627 }
003628 }
003629
003630 /* If sqlite3FindInIndex() did not find or create an index that is
003631 ** suitable for evaluating the IN operator, then evaluate using a
003632 ** sequence of comparisons.
003633 **
003634 ** This is step (1) in the in-operator.md optimized algorithm.
003635 */
003636 if( eType==IN_INDEX_NOOP ){
003637 ExprList *pList;
003638 CollSeq *pColl;
003639 int labelOk = sqlite3VdbeMakeLabel(pParse);
003640 int r2, regToFree;
003641 int regCkNull = 0;
003642 int ii;
003643 assert( ExprUseXList(pExpr) );
003644 pList = pExpr->x.pList;
003645 pColl = sqlite3ExprCollSeq(pParse, pExpr->pLeft);
003646 if( destIfNull!=destIfFalse ){
003647 regCkNull = sqlite3GetTempReg(pParse);
003648 sqlite3VdbeAddOp3(v, OP_BitAnd, rLhs, rLhs, regCkNull);
003649 }
003650 for(ii=0; ii<pList->nExpr; ii++){
003651 r2 = sqlite3ExprCodeTemp(pParse, pList->a[ii].pExpr, ®ToFree);
003652 if( regCkNull && sqlite3ExprCanBeNull(pList->a[ii].pExpr) ){
003653 sqlite3VdbeAddOp3(v, OP_BitAnd, regCkNull, r2, regCkNull);
003654 }
003655 sqlite3ReleaseTempReg(pParse, regToFree);
003656 if( ii<pList->nExpr-1 || destIfNull!=destIfFalse ){
003657 int op = rLhs!=r2 ? OP_Eq : OP_NotNull;
003658 sqlite3VdbeAddOp4(v, op, rLhs, labelOk, r2,
003659 (void*)pColl, P4_COLLSEQ);
003660 VdbeCoverageIf(v, ii<pList->nExpr-1 && op==OP_Eq);
003661 VdbeCoverageIf(v, ii==pList->nExpr-1 && op==OP_Eq);
003662 VdbeCoverageIf(v, ii<pList->nExpr-1 && op==OP_NotNull);
003663 VdbeCoverageIf(v, ii==pList->nExpr-1 && op==OP_NotNull);
003664 sqlite3VdbeChangeP5(v, zAff[0]);
003665 }else{
003666 int op = rLhs!=r2 ? OP_Ne : OP_IsNull;
003667 assert( destIfNull==destIfFalse );
003668 sqlite3VdbeAddOp4(v, op, rLhs, destIfFalse, r2,
003669 (void*)pColl, P4_COLLSEQ);
003670 VdbeCoverageIf(v, op==OP_Ne);
003671 VdbeCoverageIf(v, op==OP_IsNull);
003672 sqlite3VdbeChangeP5(v, zAff[0] | SQLITE_JUMPIFNULL);
003673 }
003674 }
003675 if( regCkNull ){
003676 sqlite3VdbeAddOp2(v, OP_IsNull, regCkNull, destIfNull); VdbeCoverage(v);
003677 sqlite3VdbeGoto(v, destIfFalse);
003678 }
003679 sqlite3VdbeResolveLabel(v, labelOk);
003680 sqlite3ReleaseTempReg(pParse, regCkNull);
003681 goto sqlite3ExprCodeIN_finished;
003682 }
003683
003684 /* Step 2: Check to see if the LHS contains any NULL columns. If the
003685 ** LHS does contain NULLs then the result must be either FALSE or NULL.
003686 ** We will then skip the binary search of the RHS.
003687 */
003688 if( destIfNull==destIfFalse ){
003689 destStep2 = destIfFalse;
003690 }else{
003691 destStep2 = destStep6 = sqlite3VdbeMakeLabel(pParse);
003692 }
003693 for(i=0; i<nVector; i++){
003694 Expr *p = sqlite3VectorFieldSubexpr(pExpr->pLeft, i);
003695 if( pParse->nErr ) goto sqlite3ExprCodeIN_oom_error;
003696 if( sqlite3ExprCanBeNull(p) ){
003697 sqlite3VdbeAddOp2(v, OP_IsNull, rLhs+i, destStep2);
003698 VdbeCoverage(v);
003699 }
003700 }
003701
003702 /* Step 3. The LHS is now known to be non-NULL. Do the binary search
003703 ** of the RHS using the LHS as a probe. If found, the result is
003704 ** true.
003705 */
003706 if( eType==IN_INDEX_ROWID ){
003707 /* In this case, the RHS is the ROWID of table b-tree and so we also
003708 ** know that the RHS is non-NULL. Hence, we combine steps 3 and 4
003709 ** into a single opcode. */
003710 sqlite3VdbeAddOp3(v, OP_SeekRowid, iTab, destIfFalse, rLhs);
003711 VdbeCoverage(v);
003712 addrTruthOp = sqlite3VdbeAddOp0(v, OP_Goto); /* Return True */
003713 }else{
003714 sqlite3VdbeAddOp4(v, OP_Affinity, rLhs, nVector, 0, zAff, nVector);
003715 if( destIfFalse==destIfNull ){
003716 /* Combine Step 3 and Step 5 into a single opcode */
003717 sqlite3VdbeAddOp4Int(v, OP_NotFound, iTab, destIfFalse,
003718 rLhs, nVector); VdbeCoverage(v);
003719 goto sqlite3ExprCodeIN_finished;
003720 }
003721 /* Ordinary Step 3, for the case where FALSE and NULL are distinct */
003722 addrTruthOp = sqlite3VdbeAddOp4Int(v, OP_Found, iTab, 0,
003723 rLhs, nVector); VdbeCoverage(v);
003724 }
003725
003726 /* Step 4. If the RHS is known to be non-NULL and we did not find
003727 ** an match on the search above, then the result must be FALSE.
003728 */
003729 if( rRhsHasNull && nVector==1 ){
003730 sqlite3VdbeAddOp2(v, OP_NotNull, rRhsHasNull, destIfFalse);
003731 VdbeCoverage(v);
003732 }
003733
003734 /* Step 5. If we do not care about the difference between NULL and
003735 ** FALSE, then just return false.
003736 */
003737 if( destIfFalse==destIfNull ) sqlite3VdbeGoto(v, destIfFalse);
003738
003739 /* Step 6: Loop through rows of the RHS. Compare each row to the LHS.
003740 ** If any comparison is NULL, then the result is NULL. If all
003741 ** comparisons are FALSE then the final result is FALSE.
003742 **
003743 ** For a scalar LHS, it is sufficient to check just the first row
003744 ** of the RHS.
003745 */
003746 if( destStep6 ) sqlite3VdbeResolveLabel(v, destStep6);
003747 addrTop = sqlite3VdbeAddOp2(v, OP_Rewind, iTab, destIfFalse);
003748 VdbeCoverage(v);
003749 if( nVector>1 ){
003750 destNotNull = sqlite3VdbeMakeLabel(pParse);
003751 }else{
003752 /* For nVector==1, combine steps 6 and 7 by immediately returning
003753 ** FALSE if the first comparison is not NULL */
003754 destNotNull = destIfFalse;
003755 }
003756 for(i=0; i<nVector; i++){
003757 Expr *p;
003758 CollSeq *pColl;
003759 int r3 = sqlite3GetTempReg(pParse);
003760 p = sqlite3VectorFieldSubexpr(pLeft, i);
003761 pColl = sqlite3ExprCollSeq(pParse, p);
003762 sqlite3VdbeAddOp3(v, OP_Column, iTab, i, r3);
003763 sqlite3VdbeAddOp4(v, OP_Ne, rLhs+i, destNotNull, r3,
003764 (void*)pColl, P4_COLLSEQ);
003765 VdbeCoverage(v);
003766 sqlite3ReleaseTempReg(pParse, r3);
003767 }
003768 sqlite3VdbeAddOp2(v, OP_Goto, 0, destIfNull);
003769 if( nVector>1 ){
003770 sqlite3VdbeResolveLabel(v, destNotNull);
003771 sqlite3VdbeAddOp2(v, OP_Next, iTab, addrTop+1);
003772 VdbeCoverage(v);
003773
003774 /* Step 7: If we reach this point, we know that the result must
003775 ** be false. */
003776 sqlite3VdbeAddOp2(v, OP_Goto, 0, destIfFalse);
003777 }
003778
003779 /* Jumps here in order to return true. */
003780 sqlite3VdbeJumpHere(v, addrTruthOp);
003781
003782 sqlite3ExprCodeIN_finished:
003783 if( rLhs!=rLhsOrig ) sqlite3ReleaseTempReg(pParse, rLhs);
003784 VdbeComment((v, "end IN expr"));
003785 sqlite3ExprCodeIN_oom_error:
003786 sqlite3DbFree(pParse->db, aiMap);
003787 sqlite3DbFree(pParse->db, zAff);
003788 }
003789 #endif /* SQLITE_OMIT_SUBQUERY */
003790
003791 #ifndef SQLITE_OMIT_FLOATING_POINT
003792 /*
003793 ** Generate an instruction that will put the floating point
003794 ** value described by z[0..n-1] into register iMem.
003795 **
003796 ** The z[] string will probably not be zero-terminated. But the
003797 ** z[n] character is guaranteed to be something that does not look
003798 ** like the continuation of the number.
003799 */
003800 static void codeReal(Vdbe *v, const char *z, int negateFlag, int iMem){
003801 if( ALWAYS(z!=0) ){
003802 double value;
003803 sqlite3AtoF(z, &value, sqlite3Strlen30(z), SQLITE_UTF8);
003804 assert( !sqlite3IsNaN(value) ); /* The new AtoF never returns NaN */
003805 if( negateFlag ) value = -value;
003806 sqlite3VdbeAddOp4Dup8(v, OP_Real, 0, iMem, 0, (u8*)&value, P4_REAL);
003807 }
003808 }
003809 #endif
003810
003811
003812 /*
003813 ** Generate an instruction that will put the integer describe by
003814 ** text z[0..n-1] into register iMem.
003815 **
003816 ** Expr.u.zToken is always UTF8 and zero-terminated.
003817 */
003818 static void codeInteger(Parse *pParse, Expr *pExpr, int negFlag, int iMem){
003819 Vdbe *v = pParse->pVdbe;
003820 if( pExpr->flags & EP_IntValue ){
003821 int i = pExpr->u.iValue;
003822 assert( i>=0 );
003823 if( negFlag ) i = -i;
003824 sqlite3VdbeAddOp2(v, OP_Integer, i, iMem);
003825 }else{
003826 int c;
003827 i64 value;
003828 const char *z = pExpr->u.zToken;
003829 assert( z!=0 );
003830 c = sqlite3DecOrHexToI64(z, &value);
003831 if( (c==3 && !negFlag) || (c==2) || (negFlag && value==SMALLEST_INT64)){
003832 #ifdef SQLITE_OMIT_FLOATING_POINT
003833 sqlite3ErrorMsg(pParse, "oversized integer: %s%#T", negFlag?"-":"",pExpr);
003834 #else
003835 #ifndef SQLITE_OMIT_HEX_INTEGER
003836 if( sqlite3_strnicmp(z,"0x",2)==0 ){
003837 sqlite3ErrorMsg(pParse, "hex literal too big: %s%#T",
003838 negFlag?"-":"",pExpr);
003839 }else
003840 #endif
003841 {
003842 codeReal(v, z, negFlag, iMem);
003843 }
003844 #endif
003845 }else{
003846 if( negFlag ){ value = c==3 ? SMALLEST_INT64 : -value; }
003847 sqlite3VdbeAddOp4Dup8(v, OP_Int64, 0, iMem, 0, (u8*)&value, P4_INT64);
003848 }
003849 }
003850 }
003851
003852
003853 /* Generate code that will load into register regOut a value that is
003854 ** appropriate for the iIdxCol-th column of index pIdx.
003855 */
003856 void sqlite3ExprCodeLoadIndexColumn(
003857 Parse *pParse, /* The parsing context */
003858 Index *pIdx, /* The index whose column is to be loaded */
003859 int iTabCur, /* Cursor pointing to a table row */
003860 int iIdxCol, /* The column of the index to be loaded */
003861 int regOut /* Store the index column value in this register */
003862 ){
003863 i16 iTabCol = pIdx->aiColumn[iIdxCol];
003864 if( iTabCol==XN_EXPR ){
003865 assert( pIdx->aColExpr );
003866 assert( pIdx->aColExpr->nExpr>iIdxCol );
003867 pParse->iSelfTab = iTabCur + 1;
003868 sqlite3ExprCodeCopy(pParse, pIdx->aColExpr->a[iIdxCol].pExpr, regOut);
003869 pParse->iSelfTab = 0;
003870 }else{
003871 sqlite3ExprCodeGetColumnOfTable(pParse->pVdbe, pIdx->pTable, iTabCur,
003872 iTabCol, regOut);
003873 }
003874 }
003875
003876 #ifndef SQLITE_OMIT_GENERATED_COLUMNS
003877 /*
003878 ** Generate code that will compute the value of generated column pCol
003879 ** and store the result in register regOut
003880 */
003881 void sqlite3ExprCodeGeneratedColumn(
003882 Parse *pParse, /* Parsing context */
003883 Table *pTab, /* Table containing the generated column */
003884 Column *pCol, /* The generated column */
003885 int regOut /* Put the result in this register */
003886 ){
003887 int iAddr;
003888 Vdbe *v = pParse->pVdbe;
003889 int nErr = pParse->nErr;
003890 assert( v!=0 );
003891 assert( pParse->iSelfTab!=0 );
003892 if( pParse->iSelfTab>0 ){
003893 iAddr = sqlite3VdbeAddOp3(v, OP_IfNullRow, pParse->iSelfTab-1, 0, regOut);
003894 }else{
003895 iAddr = 0;
003896 }
003897 sqlite3ExprCodeCopy(pParse, sqlite3ColumnExpr(pTab,pCol), regOut);
003898 if( pCol->affinity>=SQLITE_AFF_TEXT ){
003899 sqlite3VdbeAddOp4(v, OP_Affinity, regOut, 1, 0, &pCol->affinity, 1);
003900 }
003901 if( iAddr ) sqlite3VdbeJumpHere(v, iAddr);
003902 if( pParse->nErr>nErr ) pParse->db->errByteOffset = -1;
003903 }
003904 #endif /* SQLITE_OMIT_GENERATED_COLUMNS */
003905
003906 /*
003907 ** Generate code to extract the value of the iCol-th column of a table.
003908 */
003909 void sqlite3ExprCodeGetColumnOfTable(
003910 Vdbe *v, /* Parsing context */
003911 Table *pTab, /* The table containing the value */
003912 int iTabCur, /* The table cursor. Or the PK cursor for WITHOUT ROWID */
003913 int iCol, /* Index of the column to extract */
003914 int regOut /* Extract the value into this register */
003915 ){
003916 Column *pCol;
003917 assert( v!=0 );
003918 assert( pTab!=0 );
003919 assert( iCol!=XN_EXPR );
003920 if( iCol<0 || iCol==pTab->iPKey ){
003921 sqlite3VdbeAddOp2(v, OP_Rowid, iTabCur, regOut);
003922 VdbeComment((v, "%s.rowid", pTab->zName));
003923 }else{
003924 int op;
003925 int x;
003926 if( IsVirtual(pTab) ){
003927 op = OP_VColumn;
003928 x = iCol;
003929 #ifndef SQLITE_OMIT_GENERATED_COLUMNS
003930 }else if( (pCol = &pTab->aCol[iCol])->colFlags & COLFLAG_VIRTUAL ){
003931 Parse *pParse = sqlite3VdbeParser(v);
003932 if( pCol->colFlags & COLFLAG_BUSY ){
003933 sqlite3ErrorMsg(pParse, "generated column loop on \"%s\"",
003934 pCol->zCnName);
003935 }else{
003936 int savedSelfTab = pParse->iSelfTab;
003937 pCol->colFlags |= COLFLAG_BUSY;
003938 pParse->iSelfTab = iTabCur+1;
003939 sqlite3ExprCodeGeneratedColumn(pParse, pTab, pCol, regOut);
003940 pParse->iSelfTab = savedSelfTab;
003941 pCol->colFlags &= ~COLFLAG_BUSY;
003942 }
003943 return;
003944 #endif
003945 }else if( !HasRowid(pTab) ){
003946 testcase( iCol!=sqlite3TableColumnToStorage(pTab, iCol) );
003947 x = sqlite3TableColumnToIndex(sqlite3PrimaryKeyIndex(pTab), iCol);
003948 op = OP_Column;
003949 }else{
003950 x = sqlite3TableColumnToStorage(pTab,iCol);
003951 testcase( x!=iCol );
003952 op = OP_Column;
003953 }
003954 sqlite3VdbeAddOp3(v, op, iTabCur, x, regOut);
003955 sqlite3ColumnDefault(v, pTab, iCol, regOut);
003956 }
003957 }
003958
003959 /*
003960 ** Generate code that will extract the iColumn-th column from
003961 ** table pTab and store the column value in register iReg.
003962 **
003963 ** There must be an open cursor to pTab in iTable when this routine
003964 ** is called. If iColumn<0 then code is generated that extracts the rowid.
003965 */
003966 int sqlite3ExprCodeGetColumn(
003967 Parse *pParse, /* Parsing and code generating context */
003968 Table *pTab, /* Description of the table we are reading from */
003969 int iColumn, /* Index of the table column */
003970 int iTable, /* The cursor pointing to the table */
003971 int iReg, /* Store results here */
003972 u8 p5 /* P5 value for OP_Column + FLAGS */
003973 ){
003974 assert( pParse->pVdbe!=0 );
003975 assert( (p5 & (OPFLAG_NOCHNG|OPFLAG_TYPEOFARG|OPFLAG_LENGTHARG))==p5 );
003976 assert( IsVirtual(pTab) || (p5 & OPFLAG_NOCHNG)==0 );
003977 sqlite3ExprCodeGetColumnOfTable(pParse->pVdbe, pTab, iTable, iColumn, iReg);
003978 if( p5 ){
003979 VdbeOp *pOp = sqlite3VdbeGetLastOp(pParse->pVdbe);
003980 if( pOp->opcode==OP_Column ) pOp->p5 = p5;
003981 if( pOp->opcode==OP_VColumn ) pOp->p5 = (p5 & OPFLAG_NOCHNG);
003982 }
003983 return iReg;
003984 }
003985
003986 /*
003987 ** Generate code to move content from registers iFrom...iFrom+nReg-1
003988 ** over to iTo..iTo+nReg-1.
003989 */
003990 void sqlite3ExprCodeMove(Parse *pParse, int iFrom, int iTo, int nReg){
003991 sqlite3VdbeAddOp3(pParse->pVdbe, OP_Move, iFrom, iTo, nReg);
003992 }
003993
003994 /*
003995 ** Convert a scalar expression node to a TK_REGISTER referencing
003996 ** register iReg. The caller must ensure that iReg already contains
003997 ** the correct value for the expression.
003998 */
003999 static void exprToRegister(Expr *pExpr, int iReg){
004000 Expr *p = sqlite3ExprSkipCollateAndLikely(pExpr);
004001 if( NEVER(p==0) ) return;
004002 p->op2 = p->op;
004003 p->op = TK_REGISTER;
004004 p->iTable = iReg;
004005 ExprClearProperty(p, EP_Skip);
004006 }
004007
004008 /*
004009 ** Evaluate an expression (either a vector or a scalar expression) and store
004010 ** the result in contiguous temporary registers. Return the index of
004011 ** the first register used to store the result.
004012 **
004013 ** If the returned result register is a temporary scalar, then also write
004014 ** that register number into *piFreeable. If the returned result register
004015 ** is not a temporary or if the expression is a vector set *piFreeable
004016 ** to 0.
004017 */
004018 static int exprCodeVector(Parse *pParse, Expr *p, int *piFreeable){
004019 int iResult;
004020 int nResult = sqlite3ExprVectorSize(p);
004021 if( nResult==1 ){
004022 iResult = sqlite3ExprCodeTemp(pParse, p, piFreeable);
004023 }else{
004024 *piFreeable = 0;
004025 if( p->op==TK_SELECT ){
004026 #if SQLITE_OMIT_SUBQUERY
004027 iResult = 0;
004028 #else
004029 iResult = sqlite3CodeSubselect(pParse, p);
004030 #endif
004031 }else{
004032 int i;
004033 iResult = pParse->nMem+1;
004034 pParse->nMem += nResult;
004035 assert( ExprUseXList(p) );
004036 for(i=0; i<nResult; i++){
004037 sqlite3ExprCodeFactorable(pParse, p->x.pList->a[i].pExpr, i+iResult);
004038 }
004039 }
004040 }
004041 return iResult;
004042 }
004043
004044 /*
004045 ** If the last opcode is a OP_Copy, then set the do-not-merge flag (p5)
004046 ** so that a subsequent copy will not be merged into this one.
004047 */
004048 static void setDoNotMergeFlagOnCopy(Vdbe *v){
004049 if( sqlite3VdbeGetLastOp(v)->opcode==OP_Copy ){
004050 sqlite3VdbeChangeP5(v, 1); /* Tag trailing OP_Copy as not mergeable */
004051 }
004052 }
004053
004054 /*
004055 ** Generate code to implement special SQL functions that are implemented
004056 ** in-line rather than by using the usual callbacks.
004057 */
004058 static int exprCodeInlineFunction(
004059 Parse *pParse, /* Parsing context */
004060 ExprList *pFarg, /* List of function arguments */
004061 int iFuncId, /* Function ID. One of the INTFUNC_... values */
004062 int target /* Store function result in this register */
004063 ){
004064 int nFarg;
004065 Vdbe *v = pParse->pVdbe;
004066 assert( v!=0 );
004067 assert( pFarg!=0 );
004068 nFarg = pFarg->nExpr;
004069 assert( nFarg>0 ); /* All in-line functions have at least one argument */
004070 switch( iFuncId ){
004071 case INLINEFUNC_coalesce: {
004072 /* Attempt a direct implementation of the built-in COALESCE() and
004073 ** IFNULL() functions. This avoids unnecessary evaluation of
004074 ** arguments past the first non-NULL argument.
004075 */
004076 int endCoalesce = sqlite3VdbeMakeLabel(pParse);
004077 int i;
004078 assert( nFarg>=2 );
004079 sqlite3ExprCode(pParse, pFarg->a[0].pExpr, target);
004080 for(i=1; i<nFarg; i++){
004081 sqlite3VdbeAddOp2(v, OP_NotNull, target, endCoalesce);
004082 VdbeCoverage(v);
004083 sqlite3ExprCode(pParse, pFarg->a[i].pExpr, target);
004084 }
004085 setDoNotMergeFlagOnCopy(v);
004086 sqlite3VdbeResolveLabel(v, endCoalesce);
004087 break;
004088 }
004089 case INLINEFUNC_iif: {
004090 Expr caseExpr;
004091 memset(&caseExpr, 0, sizeof(caseExpr));
004092 caseExpr.op = TK_CASE;
004093 caseExpr.x.pList = pFarg;
004094 return sqlite3ExprCodeTarget(pParse, &caseExpr, target);
004095 }
004096 #ifdef SQLITE_ENABLE_OFFSET_SQL_FUNC
004097 case INLINEFUNC_sqlite_offset: {
004098 Expr *pArg = pFarg->a[0].pExpr;
004099 if( pArg->op==TK_COLUMN && pArg->iTable>=0 ){
004100 sqlite3VdbeAddOp3(v, OP_Offset, pArg->iTable, pArg->iColumn, target);
004101 }else{
004102 sqlite3VdbeAddOp2(v, OP_Null, 0, target);
004103 }
004104 break;
004105 }
004106 #endif
004107 default: {
004108 /* The UNLIKELY() function is a no-op. The result is the value
004109 ** of the first argument.
004110 */
004111 assert( nFarg==1 || nFarg==2 );
004112 target = sqlite3ExprCodeTarget(pParse, pFarg->a[0].pExpr, target);
004113 break;
004114 }
004115
004116 /***********************************************************************
004117 ** Test-only SQL functions that are only usable if enabled
004118 ** via SQLITE_TESTCTRL_INTERNAL_FUNCTIONS
004119 */
004120 #if !defined(SQLITE_UNTESTABLE)
004121 case INLINEFUNC_expr_compare: {
004122 /* Compare two expressions using sqlite3ExprCompare() */
004123 assert( nFarg==2 );
004124 sqlite3VdbeAddOp2(v, OP_Integer,
004125 sqlite3ExprCompare(0,pFarg->a[0].pExpr, pFarg->a[1].pExpr,-1),
004126 target);
004127 break;
004128 }
004129
004130 case INLINEFUNC_expr_implies_expr: {
004131 /* Compare two expressions using sqlite3ExprImpliesExpr() */
004132 assert( nFarg==2 );
004133 sqlite3VdbeAddOp2(v, OP_Integer,
004134 sqlite3ExprImpliesExpr(pParse,pFarg->a[0].pExpr, pFarg->a[1].pExpr,-1),
004135 target);
004136 break;
004137 }
004138
004139 case INLINEFUNC_implies_nonnull_row: {
004140 /* Result of sqlite3ExprImpliesNonNullRow() */
004141 Expr *pA1;
004142 assert( nFarg==2 );
004143 pA1 = pFarg->a[1].pExpr;
004144 if( pA1->op==TK_COLUMN ){
004145 sqlite3VdbeAddOp2(v, OP_Integer,
004146 sqlite3ExprImpliesNonNullRow(pFarg->a[0].pExpr,pA1->iTable,1),
004147 target);
004148 }else{
004149 sqlite3VdbeAddOp2(v, OP_Null, 0, target);
004150 }
004151 break;
004152 }
004153
004154 case INLINEFUNC_affinity: {
004155 /* The AFFINITY() function evaluates to a string that describes
004156 ** the type affinity of the argument. This is used for testing of
004157 ** the SQLite type logic.
004158 */
004159 const char *azAff[] = { "blob", "text", "numeric", "integer",
004160 "real", "flexnum" };
004161 char aff;
004162 assert( nFarg==1 );
004163 aff = sqlite3ExprAffinity(pFarg->a[0].pExpr);
004164 assert( aff<=SQLITE_AFF_NONE
004165 || (aff>=SQLITE_AFF_BLOB && aff<=SQLITE_AFF_FLEXNUM) );
004166 sqlite3VdbeLoadString(v, target,
004167 (aff<=SQLITE_AFF_NONE) ? "none" : azAff[aff-SQLITE_AFF_BLOB]);
004168 break;
004169 }
004170 #endif /* !defined(SQLITE_UNTESTABLE) */
004171 }
004172 return target;
004173 }
004174
004175 /*
004176 ** Check to see if pExpr is one of the indexed expressions on pParse->pIdxEpr.
004177 ** If it is, then resolve the expression by reading from the index and
004178 ** return the register into which the value has been read. If pExpr is
004179 ** not an indexed expression, then return negative.
004180 */
004181 static SQLITE_NOINLINE int sqlite3IndexedExprLookup(
004182 Parse *pParse, /* The parsing context */
004183 Expr *pExpr, /* The expression to potentially bypass */
004184 int target /* Where to store the result of the expression */
004185 ){
004186 IndexedExpr *p;
004187 Vdbe *v;
004188 for(p=pParse->pIdxEpr; p; p=p->pIENext){
004189 u8 exprAff;
004190 int iDataCur = p->iDataCur;
004191 if( iDataCur<0 ) continue;
004192 if( pParse->iSelfTab ){
004193 if( p->iDataCur!=pParse->iSelfTab-1 ) continue;
004194 iDataCur = -1;
004195 }
004196 if( sqlite3ExprCompare(0, pExpr, p->pExpr, iDataCur)!=0 ) continue;
004197 assert( p->aff>=SQLITE_AFF_BLOB && p->aff<=SQLITE_AFF_NUMERIC );
004198 exprAff = sqlite3ExprAffinity(pExpr);
004199 if( (exprAff<=SQLITE_AFF_BLOB && p->aff!=SQLITE_AFF_BLOB)
004200 || (exprAff==SQLITE_AFF_TEXT && p->aff!=SQLITE_AFF_TEXT)
004201 || (exprAff>=SQLITE_AFF_NUMERIC && p->aff!=SQLITE_AFF_NUMERIC)
004202 ){
004203 /* Affinity mismatch on a generated column */
004204 continue;
004205 }
004206
004207 v = pParse->pVdbe;
004208 assert( v!=0 );
004209 if( p->bMaybeNullRow ){
004210 /* If the index is on a NULL row due to an outer join, then we
004211 ** cannot extract the value from the index. The value must be
004212 ** computed using the original expression. */
004213 int addr = sqlite3VdbeCurrentAddr(v);
004214 sqlite3VdbeAddOp3(v, OP_IfNullRow, p->iIdxCur, addr+3, target);
004215 VdbeCoverage(v);
004216 sqlite3VdbeAddOp3(v, OP_Column, p->iIdxCur, p->iIdxCol, target);
004217 VdbeComment((v, "%s expr-column %d", p->zIdxName, p->iIdxCol));
004218 sqlite3VdbeGoto(v, 0);
004219 p = pParse->pIdxEpr;
004220 pParse->pIdxEpr = 0;
004221 sqlite3ExprCode(pParse, pExpr, target);
004222 pParse->pIdxEpr = p;
004223 sqlite3VdbeJumpHere(v, addr+2);
004224 }else{
004225 sqlite3VdbeAddOp3(v, OP_Column, p->iIdxCur, p->iIdxCol, target);
004226 VdbeComment((v, "%s expr-column %d", p->zIdxName, p->iIdxCol));
004227 }
004228 return target;
004229 }
004230 return -1; /* Not found */
004231 }
004232
004233
004234 /*
004235 ** Generate code into the current Vdbe to evaluate the given
004236 ** expression. Attempt to store the results in register "target".
004237 ** Return the register where results are stored.
004238 **
004239 ** With this routine, there is no guarantee that results will
004240 ** be stored in target. The result might be stored in some other
004241 ** register if it is convenient to do so. The calling function
004242 ** must check the return code and move the results to the desired
004243 ** register.
004244 */
004245 int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target){
004246 Vdbe *v = pParse->pVdbe; /* The VM under construction */
004247 int op; /* The opcode being coded */
004248 int inReg = target; /* Results stored in register inReg */
004249 int regFree1 = 0; /* If non-zero free this temporary register */
004250 int regFree2 = 0; /* If non-zero free this temporary register */
004251 int r1, r2; /* Various register numbers */
004252 Expr tempX; /* Temporary expression node */
004253 int p5 = 0;
004254
004255 assert( target>0 && target<=pParse->nMem );
004256 assert( v!=0 );
004257
004258 expr_code_doover:
004259 if( pExpr==0 ){
004260 op = TK_NULL;
004261 }else if( pParse->pIdxEpr!=0
004262 && !ExprHasProperty(pExpr, EP_Leaf)
004263 && (r1 = sqlite3IndexedExprLookup(pParse, pExpr, target))>=0
004264 ){
004265 return r1;
004266 }else{
004267 assert( !ExprHasVVAProperty(pExpr,EP_Immutable) );
004268 op = pExpr->op;
004269 }
004270 switch( op ){
004271 case TK_AGG_COLUMN: {
004272 AggInfo *pAggInfo = pExpr->pAggInfo;
004273 struct AggInfo_col *pCol;
004274 assert( pAggInfo!=0 );
004275 assert( pExpr->iAgg>=0 );
004276 if( pExpr->iAgg>=pAggInfo->nColumn ){
004277 /* Happens when the left table of a RIGHT JOIN is null and
004278 ** is using an expression index */
004279 sqlite3VdbeAddOp2(v, OP_Null, 0, target);
004280 #ifdef SQLITE_VDBE_COVERAGE
004281 /* Verify that the OP_Null above is exercised by tests
004282 ** tag-20230325-2 */
004283 sqlite3VdbeAddOp2(v, OP_NotNull, target, 1);
004284 VdbeCoverageNeverTaken(v);
004285 #endif
004286 break;
004287 }
004288 pCol = &pAggInfo->aCol[pExpr->iAgg];
004289 if( !pAggInfo->directMode ){
004290 return AggInfoColumnReg(pAggInfo, pExpr->iAgg);
004291 }else if( pAggInfo->useSortingIdx ){
004292 Table *pTab = pCol->pTab;
004293 sqlite3VdbeAddOp3(v, OP_Column, pAggInfo->sortingIdxPTab,
004294 pCol->iSorterColumn, target);
004295 if( pTab==0 ){
004296 /* No comment added */
004297 }else if( pCol->iColumn<0 ){
004298 VdbeComment((v,"%s.rowid",pTab->zName));
004299 }else{
004300 VdbeComment((v,"%s.%s",
004301 pTab->zName, pTab->aCol[pCol->iColumn].zCnName));
004302 if( pTab->aCol[pCol->iColumn].affinity==SQLITE_AFF_REAL ){
004303 sqlite3VdbeAddOp1(v, OP_RealAffinity, target);
004304 }
004305 }
004306 return target;
004307 }else if( pExpr->y.pTab==0 ){
004308 /* This case happens when the argument to an aggregate function
004309 ** is rewritten by aggregateConvertIndexedExprRefToColumn() */
004310 sqlite3VdbeAddOp3(v, OP_Column, pExpr->iTable, pExpr->iColumn, target);
004311 return target;
004312 }
004313 /* Otherwise, fall thru into the TK_COLUMN case */
004314 /* no break */ deliberate_fall_through
004315 }
004316 case TK_COLUMN: {
004317 int iTab = pExpr->iTable;
004318 int iReg;
004319 if( ExprHasProperty(pExpr, EP_FixedCol) ){
004320 /* This COLUMN expression is really a constant due to WHERE clause
004321 ** constraints, and that constant is coded by the pExpr->pLeft
004322 ** expression. However, make sure the constant has the correct
004323 ** datatype by applying the Affinity of the table column to the
004324 ** constant.
004325 */
004326 int aff;
004327 iReg = sqlite3ExprCodeTarget(pParse, pExpr->pLeft,target);
004328 assert( ExprUseYTab(pExpr) );
004329 assert( pExpr->y.pTab!=0 );
004330 aff = sqlite3TableColumnAffinity(pExpr->y.pTab, pExpr->iColumn);
004331 if( aff>SQLITE_AFF_BLOB ){
004332 static const char zAff[] = "B\000C\000D\000E\000F";
004333 assert( SQLITE_AFF_BLOB=='A' );
004334 assert( SQLITE_AFF_TEXT=='B' );
004335 sqlite3VdbeAddOp4(v, OP_Affinity, iReg, 1, 0,
004336 &zAff[(aff-'B')*2], P4_STATIC);
004337 }
004338 return iReg;
004339 }
004340 if( iTab<0 ){
004341 if( pParse->iSelfTab<0 ){
004342 /* Other columns in the same row for CHECK constraints or
004343 ** generated columns or for inserting into partial index.
004344 ** The row is unpacked into registers beginning at
004345 ** 0-(pParse->iSelfTab). The rowid (if any) is in a register
004346 ** immediately prior to the first column.
004347 */
004348 Column *pCol;
004349 Table *pTab;
004350 int iSrc;
004351 int iCol = pExpr->iColumn;
004352 assert( ExprUseYTab(pExpr) );
004353 pTab = pExpr->y.pTab;
004354 assert( pTab!=0 );
004355 assert( iCol>=XN_ROWID );
004356 assert( iCol<pTab->nCol );
004357 if( iCol<0 ){
004358 return -1-pParse->iSelfTab;
004359 }
004360 pCol = pTab->aCol + iCol;
004361 testcase( iCol!=sqlite3TableColumnToStorage(pTab,iCol) );
004362 iSrc = sqlite3TableColumnToStorage(pTab, iCol) - pParse->iSelfTab;
004363 #ifndef SQLITE_OMIT_GENERATED_COLUMNS
004364 if( pCol->colFlags & COLFLAG_GENERATED ){
004365 if( pCol->colFlags & COLFLAG_BUSY ){
004366 sqlite3ErrorMsg(pParse, "generated column loop on \"%s\"",
004367 pCol->zCnName);
004368 return 0;
004369 }
004370 pCol->colFlags |= COLFLAG_BUSY;
004371 if( pCol->colFlags & COLFLAG_NOTAVAIL ){
004372 sqlite3ExprCodeGeneratedColumn(pParse, pTab, pCol, iSrc);
004373 }
004374 pCol->colFlags &= ~(COLFLAG_BUSY|COLFLAG_NOTAVAIL);
004375 return iSrc;
004376 }else
004377 #endif /* SQLITE_OMIT_GENERATED_COLUMNS */
004378 if( pCol->affinity==SQLITE_AFF_REAL ){
004379 sqlite3VdbeAddOp2(v, OP_SCopy, iSrc, target);
004380 sqlite3VdbeAddOp1(v, OP_RealAffinity, target);
004381 return target;
004382 }else{
004383 return iSrc;
004384 }
004385 }else{
004386 /* Coding an expression that is part of an index where column names
004387 ** in the index refer to the table to which the index belongs */
004388 iTab = pParse->iSelfTab - 1;
004389 }
004390 }
004391 assert( ExprUseYTab(pExpr) );
004392 assert( pExpr->y.pTab!=0 );
004393 iReg = sqlite3ExprCodeGetColumn(pParse, pExpr->y.pTab,
004394 pExpr->iColumn, iTab, target,
004395 pExpr->op2);
004396 return iReg;
004397 }
004398 case TK_INTEGER: {
004399 codeInteger(pParse, pExpr, 0, target);
004400 return target;
004401 }
004402 case TK_TRUEFALSE: {
004403 sqlite3VdbeAddOp2(v, OP_Integer, sqlite3ExprTruthValue(pExpr), target);
004404 return target;
004405 }
004406 #ifndef SQLITE_OMIT_FLOATING_POINT
004407 case TK_FLOAT: {
004408 assert( !ExprHasProperty(pExpr, EP_IntValue) );
004409 codeReal(v, pExpr->u.zToken, 0, target);
004410 return target;
004411 }
004412 #endif
004413 case TK_STRING: {
004414 assert( !ExprHasProperty(pExpr, EP_IntValue) );
004415 sqlite3VdbeLoadString(v, target, pExpr->u.zToken);
004416 return target;
004417 }
004418 default: {
004419 /* Make NULL the default case so that if a bug causes an illegal
004420 ** Expr node to be passed into this function, it will be handled
004421 ** sanely and not crash. But keep the assert() to bring the problem
004422 ** to the attention of the developers. */
004423 assert( op==TK_NULL || op==TK_ERROR || pParse->db->mallocFailed );
004424 sqlite3VdbeAddOp2(v, OP_Null, 0, target);
004425 return target;
004426 }
004427 #ifndef SQLITE_OMIT_BLOB_LITERAL
004428 case TK_BLOB: {
004429 int n;
004430 const char *z;
004431 char *zBlob;
004432 assert( !ExprHasProperty(pExpr, EP_IntValue) );
004433 assert( pExpr->u.zToken[0]=='x' || pExpr->u.zToken[0]=='X' );
004434 assert( pExpr->u.zToken[1]=='\'' );
004435 z = &pExpr->u.zToken[2];
004436 n = sqlite3Strlen30(z) - 1;
004437 assert( z[n]=='\'' );
004438 zBlob = sqlite3HexToBlob(sqlite3VdbeDb(v), z, n);
004439 sqlite3VdbeAddOp4(v, OP_Blob, n/2, target, 0, zBlob, P4_DYNAMIC);
004440 return target;
004441 }
004442 #endif
004443 case TK_VARIABLE: {
004444 assert( !ExprHasProperty(pExpr, EP_IntValue) );
004445 assert( pExpr->u.zToken!=0 );
004446 assert( pExpr->u.zToken[0]!=0 );
004447 sqlite3VdbeAddOp2(v, OP_Variable, pExpr->iColumn, target);
004448 if( pExpr->u.zToken[1]!=0 ){
004449 const char *z = sqlite3VListNumToName(pParse->pVList, pExpr->iColumn);
004450 assert( pExpr->u.zToken[0]=='?' || (z && !strcmp(pExpr->u.zToken, z)) );
004451 pParse->pVList[0] = 0; /* Indicate VList may no longer be enlarged */
004452 sqlite3VdbeAppendP4(v, (char*)z, P4_STATIC);
004453 }
004454 return target;
004455 }
004456 case TK_REGISTER: {
004457 return pExpr->iTable;
004458 }
004459 #ifndef SQLITE_OMIT_CAST
004460 case TK_CAST: {
004461 /* Expressions of the form: CAST(pLeft AS token) */
004462 sqlite3ExprCode(pParse, pExpr->pLeft, target);
004463 assert( inReg==target );
004464 assert( !ExprHasProperty(pExpr, EP_IntValue) );
004465 sqlite3VdbeAddOp2(v, OP_Cast, target,
004466 sqlite3AffinityType(pExpr->u.zToken, 0));
004467 return inReg;
004468 }
004469 #endif /* SQLITE_OMIT_CAST */
004470 case TK_IS:
004471 case TK_ISNOT:
004472 op = (op==TK_IS) ? TK_EQ : TK_NE;
004473 p5 = SQLITE_NULLEQ;
004474 /* fall-through */
004475 case TK_LT:
004476 case TK_LE:
004477 case TK_GT:
004478 case TK_GE:
004479 case TK_NE:
004480 case TK_EQ: {
004481 Expr *pLeft = pExpr->pLeft;
004482 if( sqlite3ExprIsVector(pLeft) ){
004483 codeVectorCompare(pParse, pExpr, target, op, p5);
004484 }else{
004485 r1 = sqlite3ExprCodeTemp(pParse, pLeft, ®Free1);
004486 r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, ®Free2);
004487 sqlite3VdbeAddOp2(v, OP_Integer, 1, inReg);
004488 codeCompare(pParse, pLeft, pExpr->pRight, op, r1, r2,
004489 sqlite3VdbeCurrentAddr(v)+2, p5,
004490 ExprHasProperty(pExpr,EP_Commuted));
004491 assert(TK_LT==OP_Lt); testcase(op==OP_Lt); VdbeCoverageIf(v,op==OP_Lt);
004492 assert(TK_LE==OP_Le); testcase(op==OP_Le); VdbeCoverageIf(v,op==OP_Le);
004493 assert(TK_GT==OP_Gt); testcase(op==OP_Gt); VdbeCoverageIf(v,op==OP_Gt);
004494 assert(TK_GE==OP_Ge); testcase(op==OP_Ge); VdbeCoverageIf(v,op==OP_Ge);
004495 assert(TK_EQ==OP_Eq); testcase(op==OP_Eq); VdbeCoverageIf(v,op==OP_Eq);
004496 assert(TK_NE==OP_Ne); testcase(op==OP_Ne); VdbeCoverageIf(v,op==OP_Ne);
004497 if( p5==SQLITE_NULLEQ ){
004498 sqlite3VdbeAddOp2(v, OP_Integer, 0, inReg);
004499 }else{
004500 sqlite3VdbeAddOp3(v, OP_ZeroOrNull, r1, inReg, r2);
004501 }
004502 testcase( regFree1==0 );
004503 testcase( regFree2==0 );
004504 }
004505 break;
004506 }
004507 case TK_AND:
004508 case TK_OR:
004509 case TK_PLUS:
004510 case TK_STAR:
004511 case TK_MINUS:
004512 case TK_REM:
004513 case TK_BITAND:
004514 case TK_BITOR:
004515 case TK_SLASH:
004516 case TK_LSHIFT:
004517 case TK_RSHIFT:
004518 case TK_CONCAT: {
004519 assert( TK_AND==OP_And ); testcase( op==TK_AND );
004520 assert( TK_OR==OP_Or ); testcase( op==TK_OR );
004521 assert( TK_PLUS==OP_Add ); testcase( op==TK_PLUS );
004522 assert( TK_MINUS==OP_Subtract ); testcase( op==TK_MINUS );
004523 assert( TK_REM==OP_Remainder ); testcase( op==TK_REM );
004524 assert( TK_BITAND==OP_BitAnd ); testcase( op==TK_BITAND );
004525 assert( TK_BITOR==OP_BitOr ); testcase( op==TK_BITOR );
004526 assert( TK_SLASH==OP_Divide ); testcase( op==TK_SLASH );
004527 assert( TK_LSHIFT==OP_ShiftLeft ); testcase( op==TK_LSHIFT );
004528 assert( TK_RSHIFT==OP_ShiftRight ); testcase( op==TK_RSHIFT );
004529 assert( TK_CONCAT==OP_Concat ); testcase( op==TK_CONCAT );
004530 r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free1);
004531 r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, ®Free2);
004532 sqlite3VdbeAddOp3(v, op, r2, r1, target);
004533 testcase( regFree1==0 );
004534 testcase( regFree2==0 );
004535 break;
004536 }
004537 case TK_UMINUS: {
004538 Expr *pLeft = pExpr->pLeft;
004539 assert( pLeft );
004540 if( pLeft->op==TK_INTEGER ){
004541 codeInteger(pParse, pLeft, 1, target);
004542 return target;
004543 #ifndef SQLITE_OMIT_FLOATING_POINT
004544 }else if( pLeft->op==TK_FLOAT ){
004545 assert( !ExprHasProperty(pExpr, EP_IntValue) );
004546 codeReal(v, pLeft->u.zToken, 1, target);
004547 return target;
004548 #endif
004549 }else{
004550 tempX.op = TK_INTEGER;
004551 tempX.flags = EP_IntValue|EP_TokenOnly;
004552 tempX.u.iValue = 0;
004553 ExprClearVVAProperties(&tempX);
004554 r1 = sqlite3ExprCodeTemp(pParse, &tempX, ®Free1);
004555 r2 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free2);
004556 sqlite3VdbeAddOp3(v, OP_Subtract, r2, r1, target);
004557 testcase( regFree2==0 );
004558 }
004559 break;
004560 }
004561 case TK_BITNOT:
004562 case TK_NOT: {
004563 assert( TK_BITNOT==OP_BitNot ); testcase( op==TK_BITNOT );
004564 assert( TK_NOT==OP_Not ); testcase( op==TK_NOT );
004565 r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free1);
004566 testcase( regFree1==0 );
004567 sqlite3VdbeAddOp2(v, op, r1, inReg);
004568 break;
004569 }
004570 case TK_TRUTH: {
004571 int isTrue; /* IS TRUE or IS NOT TRUE */
004572 int bNormal; /* IS TRUE or IS FALSE */
004573 r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free1);
004574 testcase( regFree1==0 );
004575 isTrue = sqlite3ExprTruthValue(pExpr->pRight);
004576 bNormal = pExpr->op2==TK_IS;
004577 testcase( isTrue && bNormal);
004578 testcase( !isTrue && bNormal);
004579 sqlite3VdbeAddOp4Int(v, OP_IsTrue, r1, inReg, !isTrue, isTrue ^ bNormal);
004580 break;
004581 }
004582 case TK_ISNULL:
004583 case TK_NOTNULL: {
004584 int addr;
004585 assert( TK_ISNULL==OP_IsNull ); testcase( op==TK_ISNULL );
004586 assert( TK_NOTNULL==OP_NotNull ); testcase( op==TK_NOTNULL );
004587 sqlite3VdbeAddOp2(v, OP_Integer, 1, target);
004588 r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free1);
004589 testcase( regFree1==0 );
004590 addr = sqlite3VdbeAddOp1(v, op, r1);
004591 VdbeCoverageIf(v, op==TK_ISNULL);
004592 VdbeCoverageIf(v, op==TK_NOTNULL);
004593 sqlite3VdbeAddOp2(v, OP_Integer, 0, target);
004594 sqlite3VdbeJumpHere(v, addr);
004595 break;
004596 }
004597 case TK_AGG_FUNCTION: {
004598 AggInfo *pInfo = pExpr->pAggInfo;
004599 if( pInfo==0
004600 || NEVER(pExpr->iAgg<0)
004601 || NEVER(pExpr->iAgg>=pInfo->nFunc)
004602 ){
004603 assert( !ExprHasProperty(pExpr, EP_IntValue) );
004604 sqlite3ErrorMsg(pParse, "misuse of aggregate: %#T()", pExpr);
004605 }else{
004606 return AggInfoFuncReg(pInfo, pExpr->iAgg);
004607 }
004608 break;
004609 }
004610 case TK_FUNCTION: {
004611 ExprList *pFarg; /* List of function arguments */
004612 int nFarg; /* Number of function arguments */
004613 FuncDef *pDef; /* The function definition object */
004614 const char *zId; /* The function name */
004615 u32 constMask = 0; /* Mask of function arguments that are constant */
004616 int i; /* Loop counter */
004617 sqlite3 *db = pParse->db; /* The database connection */
004618 u8 enc = ENC(db); /* The text encoding used by this database */
004619 CollSeq *pColl = 0; /* A collating sequence */
004620
004621 #ifndef SQLITE_OMIT_WINDOWFUNC
004622 if( ExprHasProperty(pExpr, EP_WinFunc) ){
004623 return pExpr->y.pWin->regResult;
004624 }
004625 #endif
004626
004627 if( ConstFactorOk(pParse) && sqlite3ExprIsConstantNotJoin(pExpr) ){
004628 /* SQL functions can be expensive. So try to avoid running them
004629 ** multiple times if we know they always give the same result */
004630 return sqlite3ExprCodeRunJustOnce(pParse, pExpr, -1);
004631 }
004632 assert( !ExprHasProperty(pExpr, EP_TokenOnly) );
004633 assert( ExprUseXList(pExpr) );
004634 pFarg = pExpr->x.pList;
004635 nFarg = pFarg ? pFarg->nExpr : 0;
004636 assert( !ExprHasProperty(pExpr, EP_IntValue) );
004637 zId = pExpr->u.zToken;
004638 pDef = sqlite3FindFunction(db, zId, nFarg, enc, 0);
004639 #ifdef SQLITE_ENABLE_UNKNOWN_SQL_FUNCTION
004640 if( pDef==0 && pParse->explain ){
004641 pDef = sqlite3FindFunction(db, "unknown", nFarg, enc, 0);
004642 }
004643 #endif
004644 if( pDef==0 || pDef->xFinalize!=0 ){
004645 sqlite3ErrorMsg(pParse, "unknown function: %#T()", pExpr);
004646 break;
004647 }
004648 if( (pDef->funcFlags & SQLITE_FUNC_INLINE)!=0 && ALWAYS(pFarg!=0) ){
004649 assert( (pDef->funcFlags & SQLITE_FUNC_UNSAFE)==0 );
004650 assert( (pDef->funcFlags & SQLITE_FUNC_DIRECT)==0 );
004651 return exprCodeInlineFunction(pParse, pFarg,
004652 SQLITE_PTR_TO_INT(pDef->pUserData), target);
004653 }else if( pDef->funcFlags & (SQLITE_FUNC_DIRECT|SQLITE_FUNC_UNSAFE) ){
004654 sqlite3ExprFunctionUsable(pParse, pExpr, pDef);
004655 }
004656
004657 for(i=0; i<nFarg; i++){
004658 if( i<32 && sqlite3ExprIsConstant(pFarg->a[i].pExpr) ){
004659 testcase( i==31 );
004660 constMask |= MASKBIT32(i);
004661 }
004662 if( (pDef->funcFlags & SQLITE_FUNC_NEEDCOLL)!=0 && !pColl ){
004663 pColl = sqlite3ExprCollSeq(pParse, pFarg->a[i].pExpr);
004664 }
004665 }
004666 if( pFarg ){
004667 if( constMask ){
004668 r1 = pParse->nMem+1;
004669 pParse->nMem += nFarg;
004670 }else{
004671 r1 = sqlite3GetTempRange(pParse, nFarg);
004672 }
004673
004674 /* For length() and typeof() and octet_length() functions,
004675 ** set the P5 parameter to the OP_Column opcode to OPFLAG_LENGTHARG
004676 ** or OPFLAG_TYPEOFARG or OPFLAG_BYTELENARG respectively, to avoid
004677 ** unnecessary data loading.
004678 */
004679 if( (pDef->funcFlags & (SQLITE_FUNC_LENGTH|SQLITE_FUNC_TYPEOF))!=0 ){
004680 u8 exprOp;
004681 assert( nFarg==1 );
004682 assert( pFarg->a[0].pExpr!=0 );
004683 exprOp = pFarg->a[0].pExpr->op;
004684 if( exprOp==TK_COLUMN || exprOp==TK_AGG_COLUMN ){
004685 assert( SQLITE_FUNC_LENGTH==OPFLAG_LENGTHARG );
004686 assert( SQLITE_FUNC_TYPEOF==OPFLAG_TYPEOFARG );
004687 assert( SQLITE_FUNC_BYTELEN==OPFLAG_BYTELENARG );
004688 assert( (OPFLAG_LENGTHARG|OPFLAG_TYPEOFARG)==OPFLAG_BYTELENARG );
004689 testcase( (pDef->funcFlags & OPFLAG_BYTELENARG)==OPFLAG_LENGTHARG );
004690 testcase( (pDef->funcFlags & OPFLAG_BYTELENARG)==OPFLAG_TYPEOFARG );
004691 testcase( (pDef->funcFlags & OPFLAG_BYTELENARG)==OPFLAG_BYTELENARG);
004692 pFarg->a[0].pExpr->op2 = pDef->funcFlags & OPFLAG_BYTELENARG;
004693 }
004694 }
004695
004696 sqlite3ExprCodeExprList(pParse, pFarg, r1, 0, SQLITE_ECEL_FACTOR);
004697 }else{
004698 r1 = 0;
004699 }
004700 #ifndef SQLITE_OMIT_VIRTUALTABLE
004701 /* Possibly overload the function if the first argument is
004702 ** a virtual table column.
004703 **
004704 ** For infix functions (LIKE, GLOB, REGEXP, and MATCH) use the
004705 ** second argument, not the first, as the argument to test to
004706 ** see if it is a column in a virtual table. This is done because
004707 ** the left operand of infix functions (the operand we want to
004708 ** control overloading) ends up as the second argument to the
004709 ** function. The expression "A glob B" is equivalent to
004710 ** "glob(B,A). We want to use the A in "A glob B" to test
004711 ** for function overloading. But we use the B term in "glob(B,A)".
004712 */
004713 if( nFarg>=2 && ExprHasProperty(pExpr, EP_InfixFunc) ){
004714 pDef = sqlite3VtabOverloadFunction(db, pDef, nFarg, pFarg->a[1].pExpr);
004715 }else if( nFarg>0 ){
004716 pDef = sqlite3VtabOverloadFunction(db, pDef, nFarg, pFarg->a[0].pExpr);
004717 }
004718 #endif
004719 if( pDef->funcFlags & SQLITE_FUNC_NEEDCOLL ){
004720 if( !pColl ) pColl = db->pDfltColl;
004721 sqlite3VdbeAddOp4(v, OP_CollSeq, 0, 0, 0, (char *)pColl, P4_COLLSEQ);
004722 }
004723 sqlite3VdbeAddFunctionCall(pParse, constMask, r1, target, nFarg,
004724 pDef, pExpr->op2);
004725 if( nFarg ){
004726 if( constMask==0 ){
004727 sqlite3ReleaseTempRange(pParse, r1, nFarg);
004728 }else{
004729 sqlite3VdbeReleaseRegisters(pParse, r1, nFarg, constMask, 1);
004730 }
004731 }
004732 return target;
004733 }
004734 #ifndef SQLITE_OMIT_SUBQUERY
004735 case TK_EXISTS:
004736 case TK_SELECT: {
004737 int nCol;
004738 testcase( op==TK_EXISTS );
004739 testcase( op==TK_SELECT );
004740 if( pParse->db->mallocFailed ){
004741 return 0;
004742 }else if( op==TK_SELECT
004743 && ALWAYS( ExprUseXSelect(pExpr) )
004744 && (nCol = pExpr->x.pSelect->pEList->nExpr)!=1
004745 ){
004746 sqlite3SubselectError(pParse, nCol, 1);
004747 }else{
004748 return sqlite3CodeSubselect(pParse, pExpr);
004749 }
004750 break;
004751 }
004752 case TK_SELECT_COLUMN: {
004753 int n;
004754 Expr *pLeft = pExpr->pLeft;
004755 if( pLeft->iTable==0 || pParse->withinRJSubrtn > pLeft->op2 ){
004756 pLeft->iTable = sqlite3CodeSubselect(pParse, pLeft);
004757 pLeft->op2 = pParse->withinRJSubrtn;
004758 }
004759 assert( pLeft->op==TK_SELECT || pLeft->op==TK_ERROR );
004760 n = sqlite3ExprVectorSize(pLeft);
004761 if( pExpr->iTable!=n ){
004762 sqlite3ErrorMsg(pParse, "%d columns assigned %d values",
004763 pExpr->iTable, n);
004764 }
004765 return pLeft->iTable + pExpr->iColumn;
004766 }
004767 case TK_IN: {
004768 int destIfFalse = sqlite3VdbeMakeLabel(pParse);
004769 int destIfNull = sqlite3VdbeMakeLabel(pParse);
004770 sqlite3VdbeAddOp2(v, OP_Null, 0, target);
004771 sqlite3ExprCodeIN(pParse, pExpr, destIfFalse, destIfNull);
004772 sqlite3VdbeAddOp2(v, OP_Integer, 1, target);
004773 sqlite3VdbeResolveLabel(v, destIfFalse);
004774 sqlite3VdbeAddOp2(v, OP_AddImm, target, 0);
004775 sqlite3VdbeResolveLabel(v, destIfNull);
004776 return target;
004777 }
004778 #endif /* SQLITE_OMIT_SUBQUERY */
004779
004780
004781 /*
004782 ** x BETWEEN y AND z
004783 **
004784 ** This is equivalent to
004785 **
004786 ** x>=y AND x<=z
004787 **
004788 ** X is stored in pExpr->pLeft.
004789 ** Y is stored in pExpr->pList->a[0].pExpr.
004790 ** Z is stored in pExpr->pList->a[1].pExpr.
004791 */
004792 case TK_BETWEEN: {
004793 exprCodeBetween(pParse, pExpr, target, 0, 0);
004794 return target;
004795 }
004796 case TK_COLLATE: {
004797 if( !ExprHasProperty(pExpr, EP_Collate) ){
004798 /* A TK_COLLATE Expr node without the EP_Collate tag is a so-called
004799 ** "SOFT-COLLATE" that is added to constraints that are pushed down
004800 ** from outer queries into sub-queries by the push-down optimization.
004801 ** Clear subtypes as subtypes may not cross a subquery boundary.
004802 */
004803 assert( pExpr->pLeft );
004804 sqlite3ExprCode(pParse, pExpr->pLeft, target);
004805 sqlite3VdbeAddOp1(v, OP_ClrSubtype, target);
004806 return target;
004807 }else{
004808 pExpr = pExpr->pLeft;
004809 goto expr_code_doover; /* 2018-04-28: Prevent deep recursion. */
004810 }
004811 }
004812 case TK_SPAN:
004813 case TK_UPLUS: {
004814 pExpr = pExpr->pLeft;
004815 goto expr_code_doover; /* 2018-04-28: Prevent deep recursion. OSSFuzz. */
004816 }
004817
004818 case TK_TRIGGER: {
004819 /* If the opcode is TK_TRIGGER, then the expression is a reference
004820 ** to a column in the new.* or old.* pseudo-tables available to
004821 ** trigger programs. In this case Expr.iTable is set to 1 for the
004822 ** new.* pseudo-table, or 0 for the old.* pseudo-table. Expr.iColumn
004823 ** is set to the column of the pseudo-table to read, or to -1 to
004824 ** read the rowid field.
004825 **
004826 ** The expression is implemented using an OP_Param opcode. The p1
004827 ** parameter is set to 0 for an old.rowid reference, or to (i+1)
004828 ** to reference another column of the old.* pseudo-table, where
004829 ** i is the index of the column. For a new.rowid reference, p1 is
004830 ** set to (n+1), where n is the number of columns in each pseudo-table.
004831 ** For a reference to any other column in the new.* pseudo-table, p1
004832 ** is set to (n+2+i), where n and i are as defined previously. For
004833 ** example, if the table on which triggers are being fired is
004834 ** declared as:
004835 **
004836 ** CREATE TABLE t1(a, b);
004837 **
004838 ** Then p1 is interpreted as follows:
004839 **
004840 ** p1==0 -> old.rowid p1==3 -> new.rowid
004841 ** p1==1 -> old.a p1==4 -> new.a
004842 ** p1==2 -> old.b p1==5 -> new.b
004843 */
004844 Table *pTab;
004845 int iCol;
004846 int p1;
004847
004848 assert( ExprUseYTab(pExpr) );
004849 pTab = pExpr->y.pTab;
004850 iCol = pExpr->iColumn;
004851 p1 = pExpr->iTable * (pTab->nCol+1) + 1
004852 + sqlite3TableColumnToStorage(pTab, iCol);
004853
004854 assert( pExpr->iTable==0 || pExpr->iTable==1 );
004855 assert( iCol>=-1 && iCol<pTab->nCol );
004856 assert( pTab->iPKey<0 || iCol!=pTab->iPKey );
004857 assert( p1>=0 && p1<(pTab->nCol*2+2) );
004858
004859 sqlite3VdbeAddOp2(v, OP_Param, p1, target);
004860 VdbeComment((v, "r[%d]=%s.%s", target,
004861 (pExpr->iTable ? "new" : "old"),
004862 (pExpr->iColumn<0 ? "rowid" : pExpr->y.pTab->aCol[iCol].zCnName)
004863 ));
004864
004865 #ifndef SQLITE_OMIT_FLOATING_POINT
004866 /* If the column has REAL affinity, it may currently be stored as an
004867 ** integer. Use OP_RealAffinity to make sure it is really real.
004868 **
004869 ** EVIDENCE-OF: R-60985-57662 SQLite will convert the value back to
004870 ** floating point when extracting it from the record. */
004871 if( iCol>=0 && pTab->aCol[iCol].affinity==SQLITE_AFF_REAL ){
004872 sqlite3VdbeAddOp1(v, OP_RealAffinity, target);
004873 }
004874 #endif
004875 break;
004876 }
004877
004878 case TK_VECTOR: {
004879 sqlite3ErrorMsg(pParse, "row value misused");
004880 break;
004881 }
004882
004883 /* TK_IF_NULL_ROW Expr nodes are inserted ahead of expressions
004884 ** that derive from the right-hand table of a LEFT JOIN. The
004885 ** Expr.iTable value is the table number for the right-hand table.
004886 ** The expression is only evaluated if that table is not currently
004887 ** on a LEFT JOIN NULL row.
004888 */
004889 case TK_IF_NULL_ROW: {
004890 int addrINR;
004891 u8 okConstFactor = pParse->okConstFactor;
004892 AggInfo *pAggInfo = pExpr->pAggInfo;
004893 if( pAggInfo ){
004894 assert( pExpr->iAgg>=0 && pExpr->iAgg<pAggInfo->nColumn );
004895 if( !pAggInfo->directMode ){
004896 inReg = AggInfoColumnReg(pAggInfo, pExpr->iAgg);
004897 break;
004898 }
004899 if( pExpr->pAggInfo->useSortingIdx ){
004900 sqlite3VdbeAddOp3(v, OP_Column, pAggInfo->sortingIdxPTab,
004901 pAggInfo->aCol[pExpr->iAgg].iSorterColumn,
004902 target);
004903 inReg = target;
004904 break;
004905 }
004906 }
004907 addrINR = sqlite3VdbeAddOp3(v, OP_IfNullRow, pExpr->iTable, 0, target);
004908 /* The OP_IfNullRow opcode above can overwrite the result register with
004909 ** NULL. So we have to ensure that the result register is not a value
004910 ** that is suppose to be a constant. Two defenses are needed:
004911 ** (1) Temporarily disable factoring of constant expressions
004912 ** (2) Make sure the computed value really is stored in register
004913 ** "target" and not someplace else.
004914 */
004915 pParse->okConstFactor = 0; /* note (1) above */
004916 sqlite3ExprCode(pParse, pExpr->pLeft, target);
004917 assert( target==inReg );
004918 pParse->okConstFactor = okConstFactor;
004919 sqlite3VdbeJumpHere(v, addrINR);
004920 break;
004921 }
004922
004923 /*
004924 ** Form A:
004925 ** CASE x WHEN e1 THEN r1 WHEN e2 THEN r2 ... WHEN eN THEN rN ELSE y END
004926 **
004927 ** Form B:
004928 ** CASE WHEN e1 THEN r1 WHEN e2 THEN r2 ... WHEN eN THEN rN ELSE y END
004929 **
004930 ** Form A is can be transformed into the equivalent form B as follows:
004931 ** CASE WHEN x=e1 THEN r1 WHEN x=e2 THEN r2 ...
004932 ** WHEN x=eN THEN rN ELSE y END
004933 **
004934 ** X (if it exists) is in pExpr->pLeft.
004935 ** Y is in the last element of pExpr->x.pList if pExpr->x.pList->nExpr is
004936 ** odd. The Y is also optional. If the number of elements in x.pList
004937 ** is even, then Y is omitted and the "otherwise" result is NULL.
004938 ** Ei is in pExpr->pList->a[i*2] and Ri is pExpr->pList->a[i*2+1].
004939 **
004940 ** The result of the expression is the Ri for the first matching Ei,
004941 ** or if there is no matching Ei, the ELSE term Y, or if there is
004942 ** no ELSE term, NULL.
004943 */
004944 case TK_CASE: {
004945 int endLabel; /* GOTO label for end of CASE stmt */
004946 int nextCase; /* GOTO label for next WHEN clause */
004947 int nExpr; /* 2x number of WHEN terms */
004948 int i; /* Loop counter */
004949 ExprList *pEList; /* List of WHEN terms */
004950 struct ExprList_item *aListelem; /* Array of WHEN terms */
004951 Expr opCompare; /* The X==Ei expression */
004952 Expr *pX; /* The X expression */
004953 Expr *pTest = 0; /* X==Ei (form A) or just Ei (form B) */
004954 Expr *pDel = 0;
004955 sqlite3 *db = pParse->db;
004956
004957 assert( ExprUseXList(pExpr) && pExpr->x.pList!=0 );
004958 assert(pExpr->x.pList->nExpr > 0);
004959 pEList = pExpr->x.pList;
004960 aListelem = pEList->a;
004961 nExpr = pEList->nExpr;
004962 endLabel = sqlite3VdbeMakeLabel(pParse);
004963 if( (pX = pExpr->pLeft)!=0 ){
004964 pDel = sqlite3ExprDup(db, pX, 0);
004965 if( db->mallocFailed ){
004966 sqlite3ExprDelete(db, pDel);
004967 break;
004968 }
004969 testcase( pX->op==TK_COLUMN );
004970 exprToRegister(pDel, exprCodeVector(pParse, pDel, ®Free1));
004971 testcase( regFree1==0 );
004972 memset(&opCompare, 0, sizeof(opCompare));
004973 opCompare.op = TK_EQ;
004974 opCompare.pLeft = pDel;
004975 pTest = &opCompare;
004976 /* Ticket b351d95f9cd5ef17e9d9dbae18f5ca8611190001:
004977 ** The value in regFree1 might get SCopy-ed into the file result.
004978 ** So make sure that the regFree1 register is not reused for other
004979 ** purposes and possibly overwritten. */
004980 regFree1 = 0;
004981 }
004982 for(i=0; i<nExpr-1; i=i+2){
004983 if( pX ){
004984 assert( pTest!=0 );
004985 opCompare.pRight = aListelem[i].pExpr;
004986 }else{
004987 pTest = aListelem[i].pExpr;
004988 }
004989 nextCase = sqlite3VdbeMakeLabel(pParse);
004990 testcase( pTest->op==TK_COLUMN );
004991 sqlite3ExprIfFalse(pParse, pTest, nextCase, SQLITE_JUMPIFNULL);
004992 testcase( aListelem[i+1].pExpr->op==TK_COLUMN );
004993 sqlite3ExprCode(pParse, aListelem[i+1].pExpr, target);
004994 sqlite3VdbeGoto(v, endLabel);
004995 sqlite3VdbeResolveLabel(v, nextCase);
004996 }
004997 if( (nExpr&1)!=0 ){
004998 sqlite3ExprCode(pParse, pEList->a[nExpr-1].pExpr, target);
004999 }else{
005000 sqlite3VdbeAddOp2(v, OP_Null, 0, target);
005001 }
005002 sqlite3ExprDelete(db, pDel);
005003 setDoNotMergeFlagOnCopy(v);
005004 sqlite3VdbeResolveLabel(v, endLabel);
005005 break;
005006 }
005007 #ifndef SQLITE_OMIT_TRIGGER
005008 case TK_RAISE: {
005009 assert( pExpr->affExpr==OE_Rollback
005010 || pExpr->affExpr==OE_Abort
005011 || pExpr->affExpr==OE_Fail
005012 || pExpr->affExpr==OE_Ignore
005013 );
005014 if( !pParse->pTriggerTab && !pParse->nested ){
005015 sqlite3ErrorMsg(pParse,
005016 "RAISE() may only be used within a trigger-program");
005017 return 0;
005018 }
005019 if( pExpr->affExpr==OE_Abort ){
005020 sqlite3MayAbort(pParse);
005021 }
005022 assert( !ExprHasProperty(pExpr, EP_IntValue) );
005023 if( pExpr->affExpr==OE_Ignore ){
005024 sqlite3VdbeAddOp4(
005025 v, OP_Halt, SQLITE_OK, OE_Ignore, 0, pExpr->u.zToken,0);
005026 VdbeCoverage(v);
005027 }else{
005028 sqlite3HaltConstraint(pParse,
005029 pParse->pTriggerTab ? SQLITE_CONSTRAINT_TRIGGER : SQLITE_ERROR,
005030 pExpr->affExpr, pExpr->u.zToken, 0, 0);
005031 }
005032
005033 break;
005034 }
005035 #endif
005036 }
005037 sqlite3ReleaseTempReg(pParse, regFree1);
005038 sqlite3ReleaseTempReg(pParse, regFree2);
005039 return inReg;
005040 }
005041
005042 /*
005043 ** Generate code that will evaluate expression pExpr just one time
005044 ** per prepared statement execution.
005045 **
005046 ** If the expression uses functions (that might throw an exception) then
005047 ** guard them with an OP_Once opcode to ensure that the code is only executed
005048 ** once. If no functions are involved, then factor the code out and put it at
005049 ** the end of the prepared statement in the initialization section.
005050 **
005051 ** If regDest>=0 then the result is always stored in that register and the
005052 ** result is not reusable. If regDest<0 then this routine is free to
005053 ** store the value wherever it wants. The register where the expression
005054 ** is stored is returned. When regDest<0, two identical expressions might
005055 ** code to the same register, if they do not contain function calls and hence
005056 ** are factored out into the initialization section at the end of the
005057 ** prepared statement.
005058 */
005059 int sqlite3ExprCodeRunJustOnce(
005060 Parse *pParse, /* Parsing context */
005061 Expr *pExpr, /* The expression to code when the VDBE initializes */
005062 int regDest /* Store the value in this register */
005063 ){
005064 ExprList *p;
005065 assert( ConstFactorOk(pParse) );
005066 p = pParse->pConstExpr;
005067 if( regDest<0 && p ){
005068 struct ExprList_item *pItem;
005069 int i;
005070 for(pItem=p->a, i=p->nExpr; i>0; pItem++, i--){
005071 if( pItem->fg.reusable
005072 && sqlite3ExprCompare(0,pItem->pExpr,pExpr,-1)==0
005073 ){
005074 return pItem->u.iConstExprReg;
005075 }
005076 }
005077 }
005078 pExpr = sqlite3ExprDup(pParse->db, pExpr, 0);
005079 if( pExpr!=0 && ExprHasProperty(pExpr, EP_HasFunc) ){
005080 Vdbe *v = pParse->pVdbe;
005081 int addr;
005082 assert( v );
005083 addr = sqlite3VdbeAddOp0(v, OP_Once); VdbeCoverage(v);
005084 pParse->okConstFactor = 0;
005085 if( !pParse->db->mallocFailed ){
005086 if( regDest<0 ) regDest = ++pParse->nMem;
005087 sqlite3ExprCode(pParse, pExpr, regDest);
005088 }
005089 pParse->okConstFactor = 1;
005090 sqlite3ExprDelete(pParse->db, pExpr);
005091 sqlite3VdbeJumpHere(v, addr);
005092 }else{
005093 p = sqlite3ExprListAppend(pParse, p, pExpr);
005094 if( p ){
005095 struct ExprList_item *pItem = &p->a[p->nExpr-1];
005096 pItem->fg.reusable = regDest<0;
005097 if( regDest<0 ) regDest = ++pParse->nMem;
005098 pItem->u.iConstExprReg = regDest;
005099 }
005100 pParse->pConstExpr = p;
005101 }
005102 return regDest;
005103 }
005104
005105 /*
005106 ** Generate code to evaluate an expression and store the results
005107 ** into a register. Return the register number where the results
005108 ** are stored.
005109 **
005110 ** If the register is a temporary register that can be deallocated,
005111 ** then write its number into *pReg. If the result register is not
005112 ** a temporary, then set *pReg to zero.
005113 **
005114 ** If pExpr is a constant, then this routine might generate this
005115 ** code to fill the register in the initialization section of the
005116 ** VDBE program, in order to factor it out of the evaluation loop.
005117 */
005118 int sqlite3ExprCodeTemp(Parse *pParse, Expr *pExpr, int *pReg){
005119 int r2;
005120 pExpr = sqlite3ExprSkipCollateAndLikely(pExpr);
005121 if( ConstFactorOk(pParse)
005122 && ALWAYS(pExpr!=0)
005123 && pExpr->op!=TK_REGISTER
005124 && sqlite3ExprIsConstantNotJoin(pExpr)
005125 ){
005126 *pReg = 0;
005127 r2 = sqlite3ExprCodeRunJustOnce(pParse, pExpr, -1);
005128 }else{
005129 int r1 = sqlite3GetTempReg(pParse);
005130 r2 = sqlite3ExprCodeTarget(pParse, pExpr, r1);
005131 if( r2==r1 ){
005132 *pReg = r1;
005133 }else{
005134 sqlite3ReleaseTempReg(pParse, r1);
005135 *pReg = 0;
005136 }
005137 }
005138 return r2;
005139 }
005140
005141 /*
005142 ** Generate code that will evaluate expression pExpr and store the
005143 ** results in register target. The results are guaranteed to appear
005144 ** in register target.
005145 */
005146 void sqlite3ExprCode(Parse *pParse, Expr *pExpr, int target){
005147 int inReg;
005148
005149 assert( pExpr==0 || !ExprHasVVAProperty(pExpr,EP_Immutable) );
005150 assert( target>0 && target<=pParse->nMem );
005151 assert( pParse->pVdbe!=0 || pParse->db->mallocFailed );
005152 if( pParse->pVdbe==0 ) return;
005153 inReg = sqlite3ExprCodeTarget(pParse, pExpr, target);
005154 if( inReg!=target ){
005155 u8 op;
005156 if( ALWAYS(pExpr)
005157 && (ExprHasProperty(pExpr,EP_Subquery) || pExpr->op==TK_REGISTER)
005158 ){
005159 op = OP_Copy;
005160 }else{
005161 op = OP_SCopy;
005162 }
005163 sqlite3VdbeAddOp2(pParse->pVdbe, op, inReg, target);
005164 }
005165 }
005166
005167 /*
005168 ** Make a transient copy of expression pExpr and then code it using
005169 ** sqlite3ExprCode(). This routine works just like sqlite3ExprCode()
005170 ** except that the input expression is guaranteed to be unchanged.
005171 */
005172 void sqlite3ExprCodeCopy(Parse *pParse, Expr *pExpr, int target){
005173 sqlite3 *db = pParse->db;
005174 pExpr = sqlite3ExprDup(db, pExpr, 0);
005175 if( !db->mallocFailed ) sqlite3ExprCode(pParse, pExpr, target);
005176 sqlite3ExprDelete(db, pExpr);
005177 }
005178
005179 /*
005180 ** Generate code that will evaluate expression pExpr and store the
005181 ** results in register target. The results are guaranteed to appear
005182 ** in register target. If the expression is constant, then this routine
005183 ** might choose to code the expression at initialization time.
005184 */
005185 void sqlite3ExprCodeFactorable(Parse *pParse, Expr *pExpr, int target){
005186 if( pParse->okConstFactor && sqlite3ExprIsConstantNotJoin(pExpr) ){
005187 sqlite3ExprCodeRunJustOnce(pParse, pExpr, target);
005188 }else{
005189 sqlite3ExprCodeCopy(pParse, pExpr, target);
005190 }
005191 }
005192
005193 /*
005194 ** Generate code that pushes the value of every element of the given
005195 ** expression list into a sequence of registers beginning at target.
005196 **
005197 ** Return the number of elements evaluated. The number returned will
005198 ** usually be pList->nExpr but might be reduced if SQLITE_ECEL_OMITREF
005199 ** is defined.
005200 **
005201 ** The SQLITE_ECEL_DUP flag prevents the arguments from being
005202 ** filled using OP_SCopy. OP_Copy must be used instead.
005203 **
005204 ** The SQLITE_ECEL_FACTOR argument allows constant arguments to be
005205 ** factored out into initialization code.
005206 **
005207 ** The SQLITE_ECEL_REF flag means that expressions in the list with
005208 ** ExprList.a[].u.x.iOrderByCol>0 have already been evaluated and stored
005209 ** in registers at srcReg, and so the value can be copied from there.
005210 ** If SQLITE_ECEL_OMITREF is also set, then the values with u.x.iOrderByCol>0
005211 ** are simply omitted rather than being copied from srcReg.
005212 */
005213 int sqlite3ExprCodeExprList(
005214 Parse *pParse, /* Parsing context */
005215 ExprList *pList, /* The expression list to be coded */
005216 int target, /* Where to write results */
005217 int srcReg, /* Source registers if SQLITE_ECEL_REF */
005218 u8 flags /* SQLITE_ECEL_* flags */
005219 ){
005220 struct ExprList_item *pItem;
005221 int i, j, n;
005222 u8 copyOp = (flags & SQLITE_ECEL_DUP) ? OP_Copy : OP_SCopy;
005223 Vdbe *v = pParse->pVdbe;
005224 assert( pList!=0 );
005225 assert( target>0 );
005226 assert( pParse->pVdbe!=0 ); /* Never gets this far otherwise */
005227 n = pList->nExpr;
005228 if( !ConstFactorOk(pParse) ) flags &= ~SQLITE_ECEL_FACTOR;
005229 for(pItem=pList->a, i=0; i<n; i++, pItem++){
005230 Expr *pExpr = pItem->pExpr;
005231 #ifdef SQLITE_ENABLE_SORTER_REFERENCES
005232 if( pItem->fg.bSorterRef ){
005233 i--;
005234 n--;
005235 }else
005236 #endif
005237 if( (flags & SQLITE_ECEL_REF)!=0 && (j = pItem->u.x.iOrderByCol)>0 ){
005238 if( flags & SQLITE_ECEL_OMITREF ){
005239 i--;
005240 n--;
005241 }else{
005242 sqlite3VdbeAddOp2(v, copyOp, j+srcReg-1, target+i);
005243 }
005244 }else if( (flags & SQLITE_ECEL_FACTOR)!=0
005245 && sqlite3ExprIsConstantNotJoin(pExpr)
005246 ){
005247 sqlite3ExprCodeRunJustOnce(pParse, pExpr, target+i);
005248 }else{
005249 int inReg = sqlite3ExprCodeTarget(pParse, pExpr, target+i);
005250 if( inReg!=target+i ){
005251 VdbeOp *pOp;
005252 if( copyOp==OP_Copy
005253 && (pOp=sqlite3VdbeGetLastOp(v))->opcode==OP_Copy
005254 && pOp->p1+pOp->p3+1==inReg
005255 && pOp->p2+pOp->p3+1==target+i
005256 && pOp->p5==0 /* The do-not-merge flag must be clear */
005257 ){
005258 pOp->p3++;
005259 }else{
005260 sqlite3VdbeAddOp2(v, copyOp, inReg, target+i);
005261 }
005262 }
005263 }
005264 }
005265 return n;
005266 }
005267
005268 /*
005269 ** Generate code for a BETWEEN operator.
005270 **
005271 ** x BETWEEN y AND z
005272 **
005273 ** The above is equivalent to
005274 **
005275 ** x>=y AND x<=z
005276 **
005277 ** Code it as such, taking care to do the common subexpression
005278 ** elimination of x.
005279 **
005280 ** The xJumpIf parameter determines details:
005281 **
005282 ** NULL: Store the boolean result in reg[dest]
005283 ** sqlite3ExprIfTrue: Jump to dest if true
005284 ** sqlite3ExprIfFalse: Jump to dest if false
005285 **
005286 ** The jumpIfNull parameter is ignored if xJumpIf is NULL.
005287 */
005288 static void exprCodeBetween(
005289 Parse *pParse, /* Parsing and code generating context */
005290 Expr *pExpr, /* The BETWEEN expression */
005291 int dest, /* Jump destination or storage location */
005292 void (*xJump)(Parse*,Expr*,int,int), /* Action to take */
005293 int jumpIfNull /* Take the jump if the BETWEEN is NULL */
005294 ){
005295 Expr exprAnd; /* The AND operator in x>=y AND x<=z */
005296 Expr compLeft; /* The x>=y term */
005297 Expr compRight; /* The x<=z term */
005298 int regFree1 = 0; /* Temporary use register */
005299 Expr *pDel = 0;
005300 sqlite3 *db = pParse->db;
005301
005302 memset(&compLeft, 0, sizeof(Expr));
005303 memset(&compRight, 0, sizeof(Expr));
005304 memset(&exprAnd, 0, sizeof(Expr));
005305
005306 assert( ExprUseXList(pExpr) );
005307 pDel = sqlite3ExprDup(db, pExpr->pLeft, 0);
005308 if( db->mallocFailed==0 ){
005309 exprAnd.op = TK_AND;
005310 exprAnd.pLeft = &compLeft;
005311 exprAnd.pRight = &compRight;
005312 compLeft.op = TK_GE;
005313 compLeft.pLeft = pDel;
005314 compLeft.pRight = pExpr->x.pList->a[0].pExpr;
005315 compRight.op = TK_LE;
005316 compRight.pLeft = pDel;
005317 compRight.pRight = pExpr->x.pList->a[1].pExpr;
005318 exprToRegister(pDel, exprCodeVector(pParse, pDel, ®Free1));
005319 if( xJump ){
005320 xJump(pParse, &exprAnd, dest, jumpIfNull);
005321 }else{
005322 /* Mark the expression is being from the ON or USING clause of a join
005323 ** so that the sqlite3ExprCodeTarget() routine will not attempt to move
005324 ** it into the Parse.pConstExpr list. We should use a new bit for this,
005325 ** for clarity, but we are out of bits in the Expr.flags field so we
005326 ** have to reuse the EP_OuterON bit. Bummer. */
005327 pDel->flags |= EP_OuterON;
005328 sqlite3ExprCodeTarget(pParse, &exprAnd, dest);
005329 }
005330 sqlite3ReleaseTempReg(pParse, regFree1);
005331 }
005332 sqlite3ExprDelete(db, pDel);
005333
005334 /* Ensure adequate test coverage */
005335 testcase( xJump==sqlite3ExprIfTrue && jumpIfNull==0 && regFree1==0 );
005336 testcase( xJump==sqlite3ExprIfTrue && jumpIfNull==0 && regFree1!=0 );
005337 testcase( xJump==sqlite3ExprIfTrue && jumpIfNull!=0 && regFree1==0 );
005338 testcase( xJump==sqlite3ExprIfTrue && jumpIfNull!=0 && regFree1!=0 );
005339 testcase( xJump==sqlite3ExprIfFalse && jumpIfNull==0 && regFree1==0 );
005340 testcase( xJump==sqlite3ExprIfFalse && jumpIfNull==0 && regFree1!=0 );
005341 testcase( xJump==sqlite3ExprIfFalse && jumpIfNull!=0 && regFree1==0 );
005342 testcase( xJump==sqlite3ExprIfFalse && jumpIfNull!=0 && regFree1!=0 );
005343 testcase( xJump==0 );
005344 }
005345
005346 /*
005347 ** Generate code for a boolean expression such that a jump is made
005348 ** to the label "dest" if the expression is true but execution
005349 ** continues straight thru if the expression is false.
005350 **
005351 ** If the expression evaluates to NULL (neither true nor false), then
005352 ** take the jump if the jumpIfNull flag is SQLITE_JUMPIFNULL.
005353 **
005354 ** This code depends on the fact that certain token values (ex: TK_EQ)
005355 ** are the same as opcode values (ex: OP_Eq) that implement the corresponding
005356 ** operation. Special comments in vdbe.c and the mkopcodeh.awk script in
005357 ** the make process cause these values to align. Assert()s in the code
005358 ** below verify that the numbers are aligned correctly.
005359 */
005360 void sqlite3ExprIfTrue(Parse *pParse, Expr *pExpr, int dest, int jumpIfNull){
005361 Vdbe *v = pParse->pVdbe;
005362 int op = 0;
005363 int regFree1 = 0;
005364 int regFree2 = 0;
005365 int r1, r2;
005366
005367 assert( jumpIfNull==SQLITE_JUMPIFNULL || jumpIfNull==0 );
005368 if( NEVER(v==0) ) return; /* Existence of VDBE checked by caller */
005369 if( NEVER(pExpr==0) ) return; /* No way this can happen */
005370 assert( !ExprHasVVAProperty(pExpr, EP_Immutable) );
005371 op = pExpr->op;
005372 switch( op ){
005373 case TK_AND:
005374 case TK_OR: {
005375 Expr *pAlt = sqlite3ExprSimplifiedAndOr(pExpr);
005376 if( pAlt!=pExpr ){
005377 sqlite3ExprIfTrue(pParse, pAlt, dest, jumpIfNull);
005378 }else if( op==TK_AND ){
005379 int d2 = sqlite3VdbeMakeLabel(pParse);
005380 testcase( jumpIfNull==0 );
005381 sqlite3ExprIfFalse(pParse, pExpr->pLeft, d2,
005382 jumpIfNull^SQLITE_JUMPIFNULL);
005383 sqlite3ExprIfTrue(pParse, pExpr->pRight, dest, jumpIfNull);
005384 sqlite3VdbeResolveLabel(v, d2);
005385 }else{
005386 testcase( jumpIfNull==0 );
005387 sqlite3ExprIfTrue(pParse, pExpr->pLeft, dest, jumpIfNull);
005388 sqlite3ExprIfTrue(pParse, pExpr->pRight, dest, jumpIfNull);
005389 }
005390 break;
005391 }
005392 case TK_NOT: {
005393 testcase( jumpIfNull==0 );
005394 sqlite3ExprIfFalse(pParse, pExpr->pLeft, dest, jumpIfNull);
005395 break;
005396 }
005397 case TK_TRUTH: {
005398 int isNot; /* IS NOT TRUE or IS NOT FALSE */
005399 int isTrue; /* IS TRUE or IS NOT TRUE */
005400 testcase( jumpIfNull==0 );
005401 isNot = pExpr->op2==TK_ISNOT;
005402 isTrue = sqlite3ExprTruthValue(pExpr->pRight);
005403 testcase( isTrue && isNot );
005404 testcase( !isTrue && isNot );
005405 if( isTrue ^ isNot ){
005406 sqlite3ExprIfTrue(pParse, pExpr->pLeft, dest,
005407 isNot ? SQLITE_JUMPIFNULL : 0);
005408 }else{
005409 sqlite3ExprIfFalse(pParse, pExpr->pLeft, dest,
005410 isNot ? SQLITE_JUMPIFNULL : 0);
005411 }
005412 break;
005413 }
005414 case TK_IS:
005415 case TK_ISNOT:
005416 testcase( op==TK_IS );
005417 testcase( op==TK_ISNOT );
005418 op = (op==TK_IS) ? TK_EQ : TK_NE;
005419 jumpIfNull = SQLITE_NULLEQ;
005420 /* no break */ deliberate_fall_through
005421 case TK_LT:
005422 case TK_LE:
005423 case TK_GT:
005424 case TK_GE:
005425 case TK_NE:
005426 case TK_EQ: {
005427 if( sqlite3ExprIsVector(pExpr->pLeft) ) goto default_expr;
005428 testcase( jumpIfNull==0 );
005429 r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free1);
005430 r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, ®Free2);
005431 codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op,
005432 r1, r2, dest, jumpIfNull, ExprHasProperty(pExpr,EP_Commuted));
005433 assert(TK_LT==OP_Lt); testcase(op==OP_Lt); VdbeCoverageIf(v,op==OP_Lt);
005434 assert(TK_LE==OP_Le); testcase(op==OP_Le); VdbeCoverageIf(v,op==OP_Le);
005435 assert(TK_GT==OP_Gt); testcase(op==OP_Gt); VdbeCoverageIf(v,op==OP_Gt);
005436 assert(TK_GE==OP_Ge); testcase(op==OP_Ge); VdbeCoverageIf(v,op==OP_Ge);
005437 assert(TK_EQ==OP_Eq); testcase(op==OP_Eq);
005438 VdbeCoverageIf(v, op==OP_Eq && jumpIfNull==SQLITE_NULLEQ);
005439 VdbeCoverageIf(v, op==OP_Eq && jumpIfNull!=SQLITE_NULLEQ);
005440 assert(TK_NE==OP_Ne); testcase(op==OP_Ne);
005441 VdbeCoverageIf(v, op==OP_Ne && jumpIfNull==SQLITE_NULLEQ);
005442 VdbeCoverageIf(v, op==OP_Ne && jumpIfNull!=SQLITE_NULLEQ);
005443 testcase( regFree1==0 );
005444 testcase( regFree2==0 );
005445 break;
005446 }
005447 case TK_ISNULL:
005448 case TK_NOTNULL: {
005449 assert( TK_ISNULL==OP_IsNull ); testcase( op==TK_ISNULL );
005450 assert( TK_NOTNULL==OP_NotNull ); testcase( op==TK_NOTNULL );
005451 r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free1);
005452 sqlite3VdbeTypeofColumn(v, r1);
005453 sqlite3VdbeAddOp2(v, op, r1, dest);
005454 VdbeCoverageIf(v, op==TK_ISNULL);
005455 VdbeCoverageIf(v, op==TK_NOTNULL);
005456 testcase( regFree1==0 );
005457 break;
005458 }
005459 case TK_BETWEEN: {
005460 testcase( jumpIfNull==0 );
005461 exprCodeBetween(pParse, pExpr, dest, sqlite3ExprIfTrue, jumpIfNull);
005462 break;
005463 }
005464 #ifndef SQLITE_OMIT_SUBQUERY
005465 case TK_IN: {
005466 int destIfFalse = sqlite3VdbeMakeLabel(pParse);
005467 int destIfNull = jumpIfNull ? dest : destIfFalse;
005468 sqlite3ExprCodeIN(pParse, pExpr, destIfFalse, destIfNull);
005469 sqlite3VdbeGoto(v, dest);
005470 sqlite3VdbeResolveLabel(v, destIfFalse);
005471 break;
005472 }
005473 #endif
005474 default: {
005475 default_expr:
005476 if( ExprAlwaysTrue(pExpr) ){
005477 sqlite3VdbeGoto(v, dest);
005478 }else if( ExprAlwaysFalse(pExpr) ){
005479 /* No-op */
005480 }else{
005481 r1 = sqlite3ExprCodeTemp(pParse, pExpr, ®Free1);
005482 sqlite3VdbeAddOp3(v, OP_If, r1, dest, jumpIfNull!=0);
005483 VdbeCoverage(v);
005484 testcase( regFree1==0 );
005485 testcase( jumpIfNull==0 );
005486 }
005487 break;
005488 }
005489 }
005490 sqlite3ReleaseTempReg(pParse, regFree1);
005491 sqlite3ReleaseTempReg(pParse, regFree2);
005492 }
005493
005494 /*
005495 ** Generate code for a boolean expression such that a jump is made
005496 ** to the label "dest" if the expression is false but execution
005497 ** continues straight thru if the expression is true.
005498 **
005499 ** If the expression evaluates to NULL (neither true nor false) then
005500 ** jump if jumpIfNull is SQLITE_JUMPIFNULL or fall through if jumpIfNull
005501 ** is 0.
005502 */
005503 void sqlite3ExprIfFalse(Parse *pParse, Expr *pExpr, int dest, int jumpIfNull){
005504 Vdbe *v = pParse->pVdbe;
005505 int op = 0;
005506 int regFree1 = 0;
005507 int regFree2 = 0;
005508 int r1, r2;
005509
005510 assert( jumpIfNull==SQLITE_JUMPIFNULL || jumpIfNull==0 );
005511 if( NEVER(v==0) ) return; /* Existence of VDBE checked by caller */
005512 if( pExpr==0 ) return;
005513 assert( !ExprHasVVAProperty(pExpr,EP_Immutable) );
005514
005515 /* The value of pExpr->op and op are related as follows:
005516 **
005517 ** pExpr->op op
005518 ** --------- ----------
005519 ** TK_ISNULL OP_NotNull
005520 ** TK_NOTNULL OP_IsNull
005521 ** TK_NE OP_Eq
005522 ** TK_EQ OP_Ne
005523 ** TK_GT OP_Le
005524 ** TK_LE OP_Gt
005525 ** TK_GE OP_Lt
005526 ** TK_LT OP_Ge
005527 **
005528 ** For other values of pExpr->op, op is undefined and unused.
005529 ** The value of TK_ and OP_ constants are arranged such that we
005530 ** can compute the mapping above using the following expression.
005531 ** Assert()s verify that the computation is correct.
005532 */
005533 op = ((pExpr->op+(TK_ISNULL&1))^1)-(TK_ISNULL&1);
005534
005535 /* Verify correct alignment of TK_ and OP_ constants
005536 */
005537 assert( pExpr->op!=TK_ISNULL || op==OP_NotNull );
005538 assert( pExpr->op!=TK_NOTNULL || op==OP_IsNull );
005539 assert( pExpr->op!=TK_NE || op==OP_Eq );
005540 assert( pExpr->op!=TK_EQ || op==OP_Ne );
005541 assert( pExpr->op!=TK_LT || op==OP_Ge );
005542 assert( pExpr->op!=TK_LE || op==OP_Gt );
005543 assert( pExpr->op!=TK_GT || op==OP_Le );
005544 assert( pExpr->op!=TK_GE || op==OP_Lt );
005545
005546 switch( pExpr->op ){
005547 case TK_AND:
005548 case TK_OR: {
005549 Expr *pAlt = sqlite3ExprSimplifiedAndOr(pExpr);
005550 if( pAlt!=pExpr ){
005551 sqlite3ExprIfFalse(pParse, pAlt, dest, jumpIfNull);
005552 }else if( pExpr->op==TK_AND ){
005553 testcase( jumpIfNull==0 );
005554 sqlite3ExprIfFalse(pParse, pExpr->pLeft, dest, jumpIfNull);
005555 sqlite3ExprIfFalse(pParse, pExpr->pRight, dest, jumpIfNull);
005556 }else{
005557 int d2 = sqlite3VdbeMakeLabel(pParse);
005558 testcase( jumpIfNull==0 );
005559 sqlite3ExprIfTrue(pParse, pExpr->pLeft, d2,
005560 jumpIfNull^SQLITE_JUMPIFNULL);
005561 sqlite3ExprIfFalse(pParse, pExpr->pRight, dest, jumpIfNull);
005562 sqlite3VdbeResolveLabel(v, d2);
005563 }
005564 break;
005565 }
005566 case TK_NOT: {
005567 testcase( jumpIfNull==0 );
005568 sqlite3ExprIfTrue(pParse, pExpr->pLeft, dest, jumpIfNull);
005569 break;
005570 }
005571 case TK_TRUTH: {
005572 int isNot; /* IS NOT TRUE or IS NOT FALSE */
005573 int isTrue; /* IS TRUE or IS NOT TRUE */
005574 testcase( jumpIfNull==0 );
005575 isNot = pExpr->op2==TK_ISNOT;
005576 isTrue = sqlite3ExprTruthValue(pExpr->pRight);
005577 testcase( isTrue && isNot );
005578 testcase( !isTrue && isNot );
005579 if( isTrue ^ isNot ){
005580 /* IS TRUE and IS NOT FALSE */
005581 sqlite3ExprIfFalse(pParse, pExpr->pLeft, dest,
005582 isNot ? 0 : SQLITE_JUMPIFNULL);
005583
005584 }else{
005585 /* IS FALSE and IS NOT TRUE */
005586 sqlite3ExprIfTrue(pParse, pExpr->pLeft, dest,
005587 isNot ? 0 : SQLITE_JUMPIFNULL);
005588 }
005589 break;
005590 }
005591 case TK_IS:
005592 case TK_ISNOT:
005593 testcase( pExpr->op==TK_IS );
005594 testcase( pExpr->op==TK_ISNOT );
005595 op = (pExpr->op==TK_IS) ? TK_NE : TK_EQ;
005596 jumpIfNull = SQLITE_NULLEQ;
005597 /* no break */ deliberate_fall_through
005598 case TK_LT:
005599 case TK_LE:
005600 case TK_GT:
005601 case TK_GE:
005602 case TK_NE:
005603 case TK_EQ: {
005604 if( sqlite3ExprIsVector(pExpr->pLeft) ) goto default_expr;
005605 testcase( jumpIfNull==0 );
005606 r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free1);
005607 r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, ®Free2);
005608 codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op,
005609 r1, r2, dest, jumpIfNull,ExprHasProperty(pExpr,EP_Commuted));
005610 assert(TK_LT==OP_Lt); testcase(op==OP_Lt); VdbeCoverageIf(v,op==OP_Lt);
005611 assert(TK_LE==OP_Le); testcase(op==OP_Le); VdbeCoverageIf(v,op==OP_Le);
005612 assert(TK_GT==OP_Gt); testcase(op==OP_Gt); VdbeCoverageIf(v,op==OP_Gt);
005613 assert(TK_GE==OP_Ge); testcase(op==OP_Ge); VdbeCoverageIf(v,op==OP_Ge);
005614 assert(TK_EQ==OP_Eq); testcase(op==OP_Eq);
005615 VdbeCoverageIf(v, op==OP_Eq && jumpIfNull!=SQLITE_NULLEQ);
005616 VdbeCoverageIf(v, op==OP_Eq && jumpIfNull==SQLITE_NULLEQ);
005617 assert(TK_NE==OP_Ne); testcase(op==OP_Ne);
005618 VdbeCoverageIf(v, op==OP_Ne && jumpIfNull!=SQLITE_NULLEQ);
005619 VdbeCoverageIf(v, op==OP_Ne && jumpIfNull==SQLITE_NULLEQ);
005620 testcase( regFree1==0 );
005621 testcase( regFree2==0 );
005622 break;
005623 }
005624 case TK_ISNULL:
005625 case TK_NOTNULL: {
005626 r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free1);
005627 sqlite3VdbeTypeofColumn(v, r1);
005628 sqlite3VdbeAddOp2(v, op, r1, dest);
005629 testcase( op==TK_ISNULL ); VdbeCoverageIf(v, op==TK_ISNULL);
005630 testcase( op==TK_NOTNULL ); VdbeCoverageIf(v, op==TK_NOTNULL);
005631 testcase( regFree1==0 );
005632 break;
005633 }
005634 case TK_BETWEEN: {
005635 testcase( jumpIfNull==0 );
005636 exprCodeBetween(pParse, pExpr, dest, sqlite3ExprIfFalse, jumpIfNull);
005637 break;
005638 }
005639 #ifndef SQLITE_OMIT_SUBQUERY
005640 case TK_IN: {
005641 if( jumpIfNull ){
005642 sqlite3ExprCodeIN(pParse, pExpr, dest, dest);
005643 }else{
005644 int destIfNull = sqlite3VdbeMakeLabel(pParse);
005645 sqlite3ExprCodeIN(pParse, pExpr, dest, destIfNull);
005646 sqlite3VdbeResolveLabel(v, destIfNull);
005647 }
005648 break;
005649 }
005650 #endif
005651 default: {
005652 default_expr:
005653 if( ExprAlwaysFalse(pExpr) ){
005654 sqlite3VdbeGoto(v, dest);
005655 }else if( ExprAlwaysTrue(pExpr) ){
005656 /* no-op */
005657 }else{
005658 r1 = sqlite3ExprCodeTemp(pParse, pExpr, ®Free1);
005659 sqlite3VdbeAddOp3(v, OP_IfNot, r1, dest, jumpIfNull!=0);
005660 VdbeCoverage(v);
005661 testcase( regFree1==0 );
005662 testcase( jumpIfNull==0 );
005663 }
005664 break;
005665 }
005666 }
005667 sqlite3ReleaseTempReg(pParse, regFree1);
005668 sqlite3ReleaseTempReg(pParse, regFree2);
005669 }
005670
005671 /*
005672 ** Like sqlite3ExprIfFalse() except that a copy is made of pExpr before
005673 ** code generation, and that copy is deleted after code generation. This
005674 ** ensures that the original pExpr is unchanged.
005675 */
005676 void sqlite3ExprIfFalseDup(Parse *pParse, Expr *pExpr, int dest,int jumpIfNull){
005677 sqlite3 *db = pParse->db;
005678 Expr *pCopy = sqlite3ExprDup(db, pExpr, 0);
005679 if( db->mallocFailed==0 ){
005680 sqlite3ExprIfFalse(pParse, pCopy, dest, jumpIfNull);
005681 }
005682 sqlite3ExprDelete(db, pCopy);
005683 }
005684
005685 /*
005686 ** Expression pVar is guaranteed to be an SQL variable. pExpr may be any
005687 ** type of expression.
005688 **
005689 ** If pExpr is a simple SQL value - an integer, real, string, blob
005690 ** or NULL value - then the VDBE currently being prepared is configured
005691 ** to re-prepare each time a new value is bound to variable pVar.
005692 **
005693 ** Additionally, if pExpr is a simple SQL value and the value is the
005694 ** same as that currently bound to variable pVar, non-zero is returned.
005695 ** Otherwise, if the values are not the same or if pExpr is not a simple
005696 ** SQL value, zero is returned.
005697 */
005698 static int exprCompareVariable(
005699 const Parse *pParse,
005700 const Expr *pVar,
005701 const Expr *pExpr
005702 ){
005703 int res = 0;
005704 int iVar;
005705 sqlite3_value *pL, *pR = 0;
005706
005707 sqlite3ValueFromExpr(pParse->db, pExpr, SQLITE_UTF8, SQLITE_AFF_BLOB, &pR);
005708 if( pR ){
005709 iVar = pVar->iColumn;
005710 sqlite3VdbeSetVarmask(pParse->pVdbe, iVar);
005711 pL = sqlite3VdbeGetBoundValue(pParse->pReprepare, iVar, SQLITE_AFF_BLOB);
005712 if( pL ){
005713 if( sqlite3_value_type(pL)==SQLITE_TEXT ){
005714 sqlite3_value_text(pL); /* Make sure the encoding is UTF-8 */
005715 }
005716 res = 0==sqlite3MemCompare(pL, pR, 0);
005717 }
005718 sqlite3ValueFree(pR);
005719 sqlite3ValueFree(pL);
005720 }
005721
005722 return res;
005723 }
005724
005725 /*
005726 ** Do a deep comparison of two expression trees. Return 0 if the two
005727 ** expressions are completely identical. Return 1 if they differ only
005728 ** by a COLLATE operator at the top level. Return 2 if there are differences
005729 ** other than the top-level COLLATE operator.
005730 **
005731 ** If any subelement of pB has Expr.iTable==(-1) then it is allowed
005732 ** to compare equal to an equivalent element in pA with Expr.iTable==iTab.
005733 **
005734 ** The pA side might be using TK_REGISTER. If that is the case and pB is
005735 ** not using TK_REGISTER but is otherwise equivalent, then still return 0.
005736 **
005737 ** Sometimes this routine will return 2 even if the two expressions
005738 ** really are equivalent. If we cannot prove that the expressions are
005739 ** identical, we return 2 just to be safe. So if this routine
005740 ** returns 2, then you do not really know for certain if the two
005741 ** expressions are the same. But if you get a 0 or 1 return, then you
005742 ** can be sure the expressions are the same. In the places where
005743 ** this routine is used, it does not hurt to get an extra 2 - that
005744 ** just might result in some slightly slower code. But returning
005745 ** an incorrect 0 or 1 could lead to a malfunction.
005746 **
005747 ** If pParse is not NULL then TK_VARIABLE terms in pA with bindings in
005748 ** pParse->pReprepare can be matched against literals in pB. The
005749 ** pParse->pVdbe->expmask bitmask is updated for each variable referenced.
005750 ** If pParse is NULL (the normal case) then any TK_VARIABLE term in
005751 ** Argument pParse should normally be NULL. If it is not NULL and pA or
005752 ** pB causes a return value of 2.
005753 */
005754 int sqlite3ExprCompare(
005755 const Parse *pParse,
005756 const Expr *pA,
005757 const Expr *pB,
005758 int iTab
005759 ){
005760 u32 combinedFlags;
005761 if( pA==0 || pB==0 ){
005762 return pB==pA ? 0 : 2;
005763 }
005764 if( pParse && pA->op==TK_VARIABLE && exprCompareVariable(pParse, pA, pB) ){
005765 return 0;
005766 }
005767 combinedFlags = pA->flags | pB->flags;
005768 if( combinedFlags & EP_IntValue ){
005769 if( (pA->flags&pB->flags&EP_IntValue)!=0 && pA->u.iValue==pB->u.iValue ){
005770 return 0;
005771 }
005772 return 2;
005773 }
005774 if( pA->op!=pB->op || pA->op==TK_RAISE ){
005775 if( pA->op==TK_COLLATE && sqlite3ExprCompare(pParse, pA->pLeft,pB,iTab)<2 ){
005776 return 1;
005777 }
005778 if( pB->op==TK_COLLATE && sqlite3ExprCompare(pParse, pA,pB->pLeft,iTab)<2 ){
005779 return 1;
005780 }
005781 if( pA->op==TK_AGG_COLUMN && pB->op==TK_COLUMN
005782 && pB->iTable<0 && pA->iTable==iTab
005783 ){
005784 /* fall through */
005785 }else{
005786 return 2;
005787 }
005788 }
005789 assert( !ExprHasProperty(pA, EP_IntValue) );
005790 assert( !ExprHasProperty(pB, EP_IntValue) );
005791 if( pA->u.zToken ){
005792 if( pA->op==TK_FUNCTION || pA->op==TK_AGG_FUNCTION ){
005793 if( sqlite3StrICmp(pA->u.zToken,pB->u.zToken)!=0 ) return 2;
005794 #ifndef SQLITE_OMIT_WINDOWFUNC
005795 assert( pA->op==pB->op );
005796 if( ExprHasProperty(pA,EP_WinFunc)!=ExprHasProperty(pB,EP_WinFunc) ){
005797 return 2;
005798 }
005799 if( ExprHasProperty(pA,EP_WinFunc) ){
005800 if( sqlite3WindowCompare(pParse, pA->y.pWin, pB->y.pWin, 1)!=0 ){
005801 return 2;
005802 }
005803 }
005804 #endif
005805 }else if( pA->op==TK_NULL ){
005806 return 0;
005807 }else if( pA->op==TK_COLLATE ){
005808 if( sqlite3_stricmp(pA->u.zToken,pB->u.zToken)!=0 ) return 2;
005809 }else
005810 if( pB->u.zToken!=0
005811 && pA->op!=TK_COLUMN
005812 && pA->op!=TK_AGG_COLUMN
005813 && strcmp(pA->u.zToken,pB->u.zToken)!=0
005814 ){
005815 return 2;
005816 }
005817 }
005818 if( (pA->flags & (EP_Distinct|EP_Commuted))
005819 != (pB->flags & (EP_Distinct|EP_Commuted)) ) return 2;
005820 if( ALWAYS((combinedFlags & EP_TokenOnly)==0) ){
005821 if( combinedFlags & EP_xIsSelect ) return 2;
005822 if( (combinedFlags & EP_FixedCol)==0
005823 && sqlite3ExprCompare(pParse, pA->pLeft, pB->pLeft, iTab) ) return 2;
005824 if( sqlite3ExprCompare(pParse, pA->pRight, pB->pRight, iTab) ) return 2;
005825 if( sqlite3ExprListCompare(pA->x.pList, pB->x.pList, iTab) ) return 2;
005826 if( pA->op!=TK_STRING
005827 && pA->op!=TK_TRUEFALSE
005828 && ALWAYS((combinedFlags & EP_Reduced)==0)
005829 ){
005830 if( pA->iColumn!=pB->iColumn ) return 2;
005831 if( pA->op2!=pB->op2 && pA->op==TK_TRUTH ) return 2;
005832 if( pA->op!=TK_IN && pA->iTable!=pB->iTable && pA->iTable!=iTab ){
005833 return 2;
005834 }
005835 }
005836 }
005837 return 0;
005838 }
005839
005840 /*
005841 ** Compare two ExprList objects. Return 0 if they are identical, 1
005842 ** if they are certainly different, or 2 if it is not possible to
005843 ** determine if they are identical or not.
005844 **
005845 ** If any subelement of pB has Expr.iTable==(-1) then it is allowed
005846 ** to compare equal to an equivalent element in pA with Expr.iTable==iTab.
005847 **
005848 ** This routine might return non-zero for equivalent ExprLists. The
005849 ** only consequence will be disabled optimizations. But this routine
005850 ** must never return 0 if the two ExprList objects are different, or
005851 ** a malfunction will result.
005852 **
005853 ** Two NULL pointers are considered to be the same. But a NULL pointer
005854 ** always differs from a non-NULL pointer.
005855 */
005856 int sqlite3ExprListCompare(const ExprList *pA, const ExprList *pB, int iTab){
005857 int i;
005858 if( pA==0 && pB==0 ) return 0;
005859 if( pA==0 || pB==0 ) return 1;
005860 if( pA->nExpr!=pB->nExpr ) return 1;
005861 for(i=0; i<pA->nExpr; i++){
005862 int res;
005863 Expr *pExprA = pA->a[i].pExpr;
005864 Expr *pExprB = pB->a[i].pExpr;
005865 if( pA->a[i].fg.sortFlags!=pB->a[i].fg.sortFlags ) return 1;
005866 if( (res = sqlite3ExprCompare(0, pExprA, pExprB, iTab)) ) return res;
005867 }
005868 return 0;
005869 }
005870
005871 /*
005872 ** Like sqlite3ExprCompare() except COLLATE operators at the top-level
005873 ** are ignored.
005874 */
005875 int sqlite3ExprCompareSkip(Expr *pA,Expr *pB, int iTab){
005876 return sqlite3ExprCompare(0,
005877 sqlite3ExprSkipCollateAndLikely(pA),
005878 sqlite3ExprSkipCollateAndLikely(pB),
005879 iTab);
005880 }
005881
005882 /*
005883 ** Return non-zero if Expr p can only be true if pNN is not NULL.
005884 **
005885 ** Or if seenNot is true, return non-zero if Expr p can only be
005886 ** non-NULL if pNN is not NULL
005887 */
005888 static int exprImpliesNotNull(
005889 const Parse *pParse,/* Parsing context */
005890 const Expr *p, /* The expression to be checked */
005891 const Expr *pNN, /* The expression that is NOT NULL */
005892 int iTab, /* Table being evaluated */
005893 int seenNot /* Return true only if p can be any non-NULL value */
005894 ){
005895 assert( p );
005896 assert( pNN );
005897 if( sqlite3ExprCompare(pParse, p, pNN, iTab)==0 ){
005898 return pNN->op!=TK_NULL;
005899 }
005900 switch( p->op ){
005901 case TK_IN: {
005902 if( seenNot && ExprHasProperty(p, EP_xIsSelect) ) return 0;
005903 assert( ExprUseXSelect(p) || (p->x.pList!=0 && p->x.pList->nExpr>0) );
005904 return exprImpliesNotNull(pParse, p->pLeft, pNN, iTab, 1);
005905 }
005906 case TK_BETWEEN: {
005907 ExprList *pList;
005908 assert( ExprUseXList(p) );
005909 pList = p->x.pList;
005910 assert( pList!=0 );
005911 assert( pList->nExpr==2 );
005912 if( seenNot ) return 0;
005913 if( exprImpliesNotNull(pParse, pList->a[0].pExpr, pNN, iTab, 1)
005914 || exprImpliesNotNull(pParse, pList->a[1].pExpr, pNN, iTab, 1)
005915 ){
005916 return 1;
005917 }
005918 return exprImpliesNotNull(pParse, p->pLeft, pNN, iTab, 1);
005919 }
005920 case TK_EQ:
005921 case TK_NE:
005922 case TK_LT:
005923 case TK_LE:
005924 case TK_GT:
005925 case TK_GE:
005926 case TK_PLUS:
005927 case TK_MINUS:
005928 case TK_BITOR:
005929 case TK_LSHIFT:
005930 case TK_RSHIFT:
005931 case TK_CONCAT:
005932 seenNot = 1;
005933 /* no break */ deliberate_fall_through
005934 case TK_STAR:
005935 case TK_REM:
005936 case TK_BITAND:
005937 case TK_SLASH: {
005938 if( exprImpliesNotNull(pParse, p->pRight, pNN, iTab, seenNot) ) return 1;
005939 /* no break */ deliberate_fall_through
005940 }
005941 case TK_SPAN:
005942 case TK_COLLATE:
005943 case TK_UPLUS:
005944 case TK_UMINUS: {
005945 return exprImpliesNotNull(pParse, p->pLeft, pNN, iTab, seenNot);
005946 }
005947 case TK_TRUTH: {
005948 if( seenNot ) return 0;
005949 if( p->op2!=TK_IS ) return 0;
005950 return exprImpliesNotNull(pParse, p->pLeft, pNN, iTab, 1);
005951 }
005952 case TK_BITNOT:
005953 case TK_NOT: {
005954 return exprImpliesNotNull(pParse, p->pLeft, pNN, iTab, 1);
005955 }
005956 }
005957 return 0;
005958 }
005959
005960 /*
005961 ** Return true if we can prove the pE2 will always be true if pE1 is
005962 ** true. Return false if we cannot complete the proof or if pE2 might
005963 ** be false. Examples:
005964 **
005965 ** pE1: x==5 pE2: x==5 Result: true
005966 ** pE1: x>0 pE2: x==5 Result: false
005967 ** pE1: x=21 pE2: x=21 OR y=43 Result: true
005968 ** pE1: x!=123 pE2: x IS NOT NULL Result: true
005969 ** pE1: x!=?1 pE2: x IS NOT NULL Result: true
005970 ** pE1: x IS NULL pE2: x IS NOT NULL Result: false
005971 ** pE1: x IS ?2 pE2: x IS NOT NULL Result: false
005972 **
005973 ** When comparing TK_COLUMN nodes between pE1 and pE2, if pE2 has
005974 ** Expr.iTable<0 then assume a table number given by iTab.
005975 **
005976 ** If pParse is not NULL, then the values of bound variables in pE1 are
005977 ** compared against literal values in pE2 and pParse->pVdbe->expmask is
005978 ** modified to record which bound variables are referenced. If pParse
005979 ** is NULL, then false will be returned if pE1 contains any bound variables.
005980 **
005981 ** When in doubt, return false. Returning true might give a performance
005982 ** improvement. Returning false might cause a performance reduction, but
005983 ** it will always give the correct answer and is hence always safe.
005984 */
005985 int sqlite3ExprImpliesExpr(
005986 const Parse *pParse,
005987 const Expr *pE1,
005988 const Expr *pE2,
005989 int iTab
005990 ){
005991 if( sqlite3ExprCompare(pParse, pE1, pE2, iTab)==0 ){
005992 return 1;
005993 }
005994 if( pE2->op==TK_OR
005995 && (sqlite3ExprImpliesExpr(pParse, pE1, pE2->pLeft, iTab)
005996 || sqlite3ExprImpliesExpr(pParse, pE1, pE2->pRight, iTab) )
005997 ){
005998 return 1;
005999 }
006000 if( pE2->op==TK_NOTNULL
006001 && exprImpliesNotNull(pParse, pE1, pE2->pLeft, iTab, 0)
006002 ){
006003 return 1;
006004 }
006005 return 0;
006006 }
006007
006008 /* This is a helper function to impliesNotNullRow(). In this routine,
006009 ** set pWalker->eCode to one only if *both* of the input expressions
006010 ** separately have the implies-not-null-row property.
006011 */
006012 static void bothImplyNotNullRow(Walker *pWalker, Expr *pE1, Expr *pE2){
006013 if( pWalker->eCode==0 ){
006014 sqlite3WalkExpr(pWalker, pE1);
006015 if( pWalker->eCode ){
006016 pWalker->eCode = 0;
006017 sqlite3WalkExpr(pWalker, pE2);
006018 }
006019 }
006020 }
006021
006022 /*
006023 ** This is the Expr node callback for sqlite3ExprImpliesNonNullRow().
006024 ** If the expression node requires that the table at pWalker->iCur
006025 ** have one or more non-NULL column, then set pWalker->eCode to 1 and abort.
006026 **
006027 ** pWalker->mWFlags is non-zero if this inquiry is being undertaking on
006028 ** behalf of a RIGHT JOIN (or FULL JOIN). That makes a difference when
006029 ** evaluating terms in the ON clause of an inner join.
006030 **
006031 ** This routine controls an optimization. False positives (setting
006032 ** pWalker->eCode to 1 when it should not be) are deadly, but false-negatives
006033 ** (never setting pWalker->eCode) is a harmless missed optimization.
006034 */
006035 static int impliesNotNullRow(Walker *pWalker, Expr *pExpr){
006036 testcase( pExpr->op==TK_AGG_COLUMN );
006037 testcase( pExpr->op==TK_AGG_FUNCTION );
006038 if( ExprHasProperty(pExpr, EP_OuterON) ) return WRC_Prune;
006039 if( ExprHasProperty(pExpr, EP_InnerON) && pWalker->mWFlags ){
006040 /* If iCur is used in an inner-join ON clause to the left of a
006041 ** RIGHT JOIN, that does *not* mean that the table must be non-null.
006042 ** But it is difficult to check for that condition precisely.
006043 ** To keep things simple, any use of iCur from any inner-join is
006044 ** ignored while attempting to simplify a RIGHT JOIN. */
006045 return WRC_Prune;
006046 }
006047 switch( pExpr->op ){
006048 case TK_ISNOT:
006049 case TK_ISNULL:
006050 case TK_NOTNULL:
006051 case TK_IS:
006052 case TK_VECTOR:
006053 case TK_FUNCTION:
006054 case TK_TRUTH:
006055 case TK_CASE:
006056 testcase( pExpr->op==TK_ISNOT );
006057 testcase( pExpr->op==TK_ISNULL );
006058 testcase( pExpr->op==TK_NOTNULL );
006059 testcase( pExpr->op==TK_IS );
006060 testcase( pExpr->op==TK_VECTOR );
006061 testcase( pExpr->op==TK_FUNCTION );
006062 testcase( pExpr->op==TK_TRUTH );
006063 testcase( pExpr->op==TK_CASE );
006064 return WRC_Prune;
006065
006066 case TK_COLUMN:
006067 if( pWalker->u.iCur==pExpr->iTable ){
006068 pWalker->eCode = 1;
006069 return WRC_Abort;
006070 }
006071 return WRC_Prune;
006072
006073 case TK_OR:
006074 case TK_AND:
006075 /* Both sides of an AND or OR must separately imply non-null-row.
006076 ** Consider these cases:
006077 ** 1. NOT (x AND y)
006078 ** 2. x OR y
006079 ** If only one of x or y is non-null-row, then the overall expression
006080 ** can be true if the other arm is false (case 1) or true (case 2).
006081 */
006082 testcase( pExpr->op==TK_OR );
006083 testcase( pExpr->op==TK_AND );
006084 bothImplyNotNullRow(pWalker, pExpr->pLeft, pExpr->pRight);
006085 return WRC_Prune;
006086
006087 case TK_IN:
006088 /* Beware of "x NOT IN ()" and "x NOT IN (SELECT 1 WHERE false)",
006089 ** both of which can be true. But apart from these cases, if
006090 ** the left-hand side of the IN is NULL then the IN itself will be
006091 ** NULL. */
006092 if( ExprUseXList(pExpr) && ALWAYS(pExpr->x.pList->nExpr>0) ){
006093 sqlite3WalkExpr(pWalker, pExpr->pLeft);
006094 }
006095 return WRC_Prune;
006096
006097 case TK_BETWEEN:
006098 /* In "x NOT BETWEEN y AND z" either x must be non-null-row or else
006099 ** both y and z must be non-null row */
006100 assert( ExprUseXList(pExpr) );
006101 assert( pExpr->x.pList->nExpr==2 );
006102 sqlite3WalkExpr(pWalker, pExpr->pLeft);
006103 bothImplyNotNullRow(pWalker, pExpr->x.pList->a[0].pExpr,
006104 pExpr->x.pList->a[1].pExpr);
006105 return WRC_Prune;
006106
006107 /* Virtual tables are allowed to use constraints like x=NULL. So
006108 ** a term of the form x=y does not prove that y is not null if x
006109 ** is the column of a virtual table */
006110 case TK_EQ:
006111 case TK_NE:
006112 case TK_LT:
006113 case TK_LE:
006114 case TK_GT:
006115 case TK_GE: {
006116 Expr *pLeft = pExpr->pLeft;
006117 Expr *pRight = pExpr->pRight;
006118 testcase( pExpr->op==TK_EQ );
006119 testcase( pExpr->op==TK_NE );
006120 testcase( pExpr->op==TK_LT );
006121 testcase( pExpr->op==TK_LE );
006122 testcase( pExpr->op==TK_GT );
006123 testcase( pExpr->op==TK_GE );
006124 /* The y.pTab=0 assignment in wherecode.c always happens after the
006125 ** impliesNotNullRow() test */
006126 assert( pLeft->op!=TK_COLUMN || ExprUseYTab(pLeft) );
006127 assert( pRight->op!=TK_COLUMN || ExprUseYTab(pRight) );
006128 if( (pLeft->op==TK_COLUMN
006129 && ALWAYS(pLeft->y.pTab!=0)
006130 && IsVirtual(pLeft->y.pTab))
006131 || (pRight->op==TK_COLUMN
006132 && ALWAYS(pRight->y.pTab!=0)
006133 && IsVirtual(pRight->y.pTab))
006134 ){
006135 return WRC_Prune;
006136 }
006137 /* no break */ deliberate_fall_through
006138 }
006139 default:
006140 return WRC_Continue;
006141 }
006142 }
006143
006144 /*
006145 ** Return true (non-zero) if expression p can only be true if at least
006146 ** one column of table iTab is non-null. In other words, return true
006147 ** if expression p will always be NULL or false if every column of iTab
006148 ** is NULL.
006149 **
006150 ** False negatives are acceptable. In other words, it is ok to return
006151 ** zero even if expression p will never be true of every column of iTab
006152 ** is NULL. A false negative is merely a missed optimization opportunity.
006153 **
006154 ** False positives are not allowed, however. A false positive may result
006155 ** in an incorrect answer.
006156 **
006157 ** Terms of p that are marked with EP_OuterON (and hence that come from
006158 ** the ON or USING clauses of OUTER JOINS) are excluded from the analysis.
006159 **
006160 ** This routine is used to check if a LEFT JOIN can be converted into
006161 ** an ordinary JOIN. The p argument is the WHERE clause. If the WHERE
006162 ** clause requires that some column of the right table of the LEFT JOIN
006163 ** be non-NULL, then the LEFT JOIN can be safely converted into an
006164 ** ordinary join.
006165 */
006166 int sqlite3ExprImpliesNonNullRow(Expr *p, int iTab, int isRJ){
006167 Walker w;
006168 p = sqlite3ExprSkipCollateAndLikely(p);
006169 if( p==0 ) return 0;
006170 if( p->op==TK_NOTNULL ){
006171 p = p->pLeft;
006172 }else{
006173 while( p->op==TK_AND ){
006174 if( sqlite3ExprImpliesNonNullRow(p->pLeft, iTab, isRJ) ) return 1;
006175 p = p->pRight;
006176 }
006177 }
006178 w.xExprCallback = impliesNotNullRow;
006179 w.xSelectCallback = 0;
006180 w.xSelectCallback2 = 0;
006181 w.eCode = 0;
006182 w.mWFlags = isRJ!=0;
006183 w.u.iCur = iTab;
006184 sqlite3WalkExpr(&w, p);
006185 return w.eCode;
006186 }
006187
006188 /*
006189 ** An instance of the following structure is used by the tree walker
006190 ** to determine if an expression can be evaluated by reference to the
006191 ** index only, without having to do a search for the corresponding
006192 ** table entry. The IdxCover.pIdx field is the index. IdxCover.iCur
006193 ** is the cursor for the table.
006194 */
006195 struct IdxCover {
006196 Index *pIdx; /* The index to be tested for coverage */
006197 int iCur; /* Cursor number for the table corresponding to the index */
006198 };
006199
006200 /*
006201 ** Check to see if there are references to columns in table
006202 ** pWalker->u.pIdxCover->iCur can be satisfied using the index
006203 ** pWalker->u.pIdxCover->pIdx.
006204 */
006205 static int exprIdxCover(Walker *pWalker, Expr *pExpr){
006206 if( pExpr->op==TK_COLUMN
006207 && pExpr->iTable==pWalker->u.pIdxCover->iCur
006208 && sqlite3TableColumnToIndex(pWalker->u.pIdxCover->pIdx, pExpr->iColumn)<0
006209 ){
006210 pWalker->eCode = 1;
006211 return WRC_Abort;
006212 }
006213 return WRC_Continue;
006214 }
006215
006216 /*
006217 ** Determine if an index pIdx on table with cursor iCur contains will
006218 ** the expression pExpr. Return true if the index does cover the
006219 ** expression and false if the pExpr expression references table columns
006220 ** that are not found in the index pIdx.
006221 **
006222 ** An index covering an expression means that the expression can be
006223 ** evaluated using only the index and without having to lookup the
006224 ** corresponding table entry.
006225 */
006226 int sqlite3ExprCoveredByIndex(
006227 Expr *pExpr, /* The index to be tested */
006228 int iCur, /* The cursor number for the corresponding table */
006229 Index *pIdx /* The index that might be used for coverage */
006230 ){
006231 Walker w;
006232 struct IdxCover xcov;
006233 memset(&w, 0, sizeof(w));
006234 xcov.iCur = iCur;
006235 xcov.pIdx = pIdx;
006236 w.xExprCallback = exprIdxCover;
006237 w.u.pIdxCover = &xcov;
006238 sqlite3WalkExpr(&w, pExpr);
006239 return !w.eCode;
006240 }
006241
006242
006243 /* Structure used to pass information throughout the Walker in order to
006244 ** implement sqlite3ReferencesSrcList().
006245 */
006246 struct RefSrcList {
006247 sqlite3 *db; /* Database connection used for sqlite3DbRealloc() */
006248 SrcList *pRef; /* Looking for references to these tables */
006249 i64 nExclude; /* Number of tables to exclude from the search */
006250 int *aiExclude; /* Cursor IDs for tables to exclude from the search */
006251 };
006252
006253 /*
006254 ** Walker SELECT callbacks for sqlite3ReferencesSrcList().
006255 **
006256 ** When entering a new subquery on the pExpr argument, add all FROM clause
006257 ** entries for that subquery to the exclude list.
006258 **
006259 ** When leaving the subquery, remove those entries from the exclude list.
006260 */
006261 static int selectRefEnter(Walker *pWalker, Select *pSelect){
006262 struct RefSrcList *p = pWalker->u.pRefSrcList;
006263 SrcList *pSrc = pSelect->pSrc;
006264 i64 i, j;
006265 int *piNew;
006266 if( pSrc->nSrc==0 ) return WRC_Continue;
006267 j = p->nExclude;
006268 p->nExclude += pSrc->nSrc;
006269 piNew = sqlite3DbRealloc(p->db, p->aiExclude, p->nExclude*sizeof(int));
006270 if( piNew==0 ){
006271 p->nExclude = 0;
006272 return WRC_Abort;
006273 }else{
006274 p->aiExclude = piNew;
006275 }
006276 for(i=0; i<pSrc->nSrc; i++, j++){
006277 p->aiExclude[j] = pSrc->a[i].iCursor;
006278 }
006279 return WRC_Continue;
006280 }
006281 static void selectRefLeave(Walker *pWalker, Select *pSelect){
006282 struct RefSrcList *p = pWalker->u.pRefSrcList;
006283 SrcList *pSrc = pSelect->pSrc;
006284 if( p->nExclude ){
006285 assert( p->nExclude>=pSrc->nSrc );
006286 p->nExclude -= pSrc->nSrc;
006287 }
006288 }
006289
006290 /* This is the Walker EXPR callback for sqlite3ReferencesSrcList().
006291 **
006292 ** Set the 0x01 bit of pWalker->eCode if there is a reference to any
006293 ** of the tables shown in RefSrcList.pRef.
006294 **
006295 ** Set the 0x02 bit of pWalker->eCode if there is a reference to a
006296 ** table is in neither RefSrcList.pRef nor RefSrcList.aiExclude.
006297 */
006298 static int exprRefToSrcList(Walker *pWalker, Expr *pExpr){
006299 if( pExpr->op==TK_COLUMN
006300 || pExpr->op==TK_AGG_COLUMN
006301 ){
006302 int i;
006303 struct RefSrcList *p = pWalker->u.pRefSrcList;
006304 SrcList *pSrc = p->pRef;
006305 int nSrc = pSrc ? pSrc->nSrc : 0;
006306 for(i=0; i<nSrc; i++){
006307 if( pExpr->iTable==pSrc->a[i].iCursor ){
006308 pWalker->eCode |= 1;
006309 return WRC_Continue;
006310 }
006311 }
006312 for(i=0; i<p->nExclude && p->aiExclude[i]!=pExpr->iTable; i++){}
006313 if( i>=p->nExclude ){
006314 pWalker->eCode |= 2;
006315 }
006316 }
006317 return WRC_Continue;
006318 }
006319
006320 /*
006321 ** Check to see if pExpr references any tables in pSrcList.
006322 ** Possible return values:
006323 **
006324 ** 1 pExpr does references a table in pSrcList.
006325 **
006326 ** 0 pExpr references some table that is not defined in either
006327 ** pSrcList or in subqueries of pExpr itself.
006328 **
006329 ** -1 pExpr only references no tables at all, or it only
006330 ** references tables defined in subqueries of pExpr itself.
006331 **
006332 ** As currently used, pExpr is always an aggregate function call. That
006333 ** fact is exploited for efficiency.
006334 */
006335 int sqlite3ReferencesSrcList(Parse *pParse, Expr *pExpr, SrcList *pSrcList){
006336 Walker w;
006337 struct RefSrcList x;
006338 assert( pParse->db!=0 );
006339 memset(&w, 0, sizeof(w));
006340 memset(&x, 0, sizeof(x));
006341 w.xExprCallback = exprRefToSrcList;
006342 w.xSelectCallback = selectRefEnter;
006343 w.xSelectCallback2 = selectRefLeave;
006344 w.u.pRefSrcList = &x;
006345 x.db = pParse->db;
006346 x.pRef = pSrcList;
006347 assert( pExpr->op==TK_AGG_FUNCTION );
006348 assert( ExprUseXList(pExpr) );
006349 sqlite3WalkExprList(&w, pExpr->x.pList);
006350 #ifndef SQLITE_OMIT_WINDOWFUNC
006351 if( ExprHasProperty(pExpr, EP_WinFunc) ){
006352 sqlite3WalkExpr(&w, pExpr->y.pWin->pFilter);
006353 }
006354 #endif
006355 if( x.aiExclude ) sqlite3DbNNFreeNN(pParse->db, x.aiExclude);
006356 if( w.eCode & 0x01 ){
006357 return 1;
006358 }else if( w.eCode ){
006359 return 0;
006360 }else{
006361 return -1;
006362 }
006363 }
006364
006365 /*
006366 ** This is a Walker expression node callback.
006367 **
006368 ** For Expr nodes that contain pAggInfo pointers, make sure the AggInfo
006369 ** object that is referenced does not refer directly to the Expr. If
006370 ** it does, make a copy. This is done because the pExpr argument is
006371 ** subject to change.
006372 **
006373 ** The copy is scheduled for deletion using the sqlite3ExprDeferredDelete()
006374 ** which builds on the sqlite3ParserAddCleanup() mechanism.
006375 */
006376 static int agginfoPersistExprCb(Walker *pWalker, Expr *pExpr){
006377 if( ALWAYS(!ExprHasProperty(pExpr, EP_TokenOnly|EP_Reduced))
006378 && pExpr->pAggInfo!=0
006379 ){
006380 AggInfo *pAggInfo = pExpr->pAggInfo;
006381 int iAgg = pExpr->iAgg;
006382 Parse *pParse = pWalker->pParse;
006383 sqlite3 *db = pParse->db;
006384 assert( iAgg>=0 );
006385 if( pExpr->op!=TK_AGG_FUNCTION ){
006386 if( iAgg<pAggInfo->nColumn
006387 && pAggInfo->aCol[iAgg].pCExpr==pExpr
006388 ){
006389 pExpr = sqlite3ExprDup(db, pExpr, 0);
006390 if( pExpr ){
006391 pAggInfo->aCol[iAgg].pCExpr = pExpr;
006392 sqlite3ExprDeferredDelete(pParse, pExpr);
006393 }
006394 }
006395 }else{
006396 assert( pExpr->op==TK_AGG_FUNCTION );
006397 if( ALWAYS(iAgg<pAggInfo->nFunc)
006398 && pAggInfo->aFunc[iAgg].pFExpr==pExpr
006399 ){
006400 pExpr = sqlite3ExprDup(db, pExpr, 0);
006401 if( pExpr ){
006402 pAggInfo->aFunc[iAgg].pFExpr = pExpr;
006403 sqlite3ExprDeferredDelete(pParse, pExpr);
006404 }
006405 }
006406 }
006407 }
006408 return WRC_Continue;
006409 }
006410
006411 /*
006412 ** Initialize a Walker object so that will persist AggInfo entries referenced
006413 ** by the tree that is walked.
006414 */
006415 void sqlite3AggInfoPersistWalkerInit(Walker *pWalker, Parse *pParse){
006416 memset(pWalker, 0, sizeof(*pWalker));
006417 pWalker->pParse = pParse;
006418 pWalker->xExprCallback = agginfoPersistExprCb;
006419 pWalker->xSelectCallback = sqlite3SelectWalkNoop;
006420 }
006421
006422 /*
006423 ** Add a new element to the pAggInfo->aCol[] array. Return the index of
006424 ** the new element. Return a negative number if malloc fails.
006425 */
006426 static int addAggInfoColumn(sqlite3 *db, AggInfo *pInfo){
006427 int i;
006428 pInfo->aCol = sqlite3ArrayAllocate(
006429 db,
006430 pInfo->aCol,
006431 sizeof(pInfo->aCol[0]),
006432 &pInfo->nColumn,
006433 &i
006434 );
006435 return i;
006436 }
006437
006438 /*
006439 ** Add a new element to the pAggInfo->aFunc[] array. Return the index of
006440 ** the new element. Return a negative number if malloc fails.
006441 */
006442 static int addAggInfoFunc(sqlite3 *db, AggInfo *pInfo){
006443 int i;
006444 pInfo->aFunc = sqlite3ArrayAllocate(
006445 db,
006446 pInfo->aFunc,
006447 sizeof(pInfo->aFunc[0]),
006448 &pInfo->nFunc,
006449 &i
006450 );
006451 return i;
006452 }
006453
006454 /*
006455 ** Search the AggInfo object for an aCol[] entry that has iTable and iColumn.
006456 ** Return the index in aCol[] of the entry that describes that column.
006457 **
006458 ** If no prior entry is found, create a new one and return -1. The
006459 ** new column will have an index of pAggInfo->nColumn-1.
006460 */
006461 static void findOrCreateAggInfoColumn(
006462 Parse *pParse, /* Parsing context */
006463 AggInfo *pAggInfo, /* The AggInfo object to search and/or modify */
006464 Expr *pExpr /* Expr describing the column to find or insert */
006465 ){
006466 struct AggInfo_col *pCol;
006467 int k;
006468
006469 assert( pAggInfo->iFirstReg==0 );
006470 pCol = pAggInfo->aCol;
006471 for(k=0; k<pAggInfo->nColumn; k++, pCol++){
006472 if( pCol->pCExpr==pExpr ) return;
006473 if( pCol->iTable==pExpr->iTable
006474 && pCol->iColumn==pExpr->iColumn
006475 && pExpr->op!=TK_IF_NULL_ROW
006476 ){
006477 goto fix_up_expr;
006478 }
006479 }
006480 k = addAggInfoColumn(pParse->db, pAggInfo);
006481 if( k<0 ){
006482 /* OOM on resize */
006483 assert( pParse->db->mallocFailed );
006484 return;
006485 }
006486 pCol = &pAggInfo->aCol[k];
006487 assert( ExprUseYTab(pExpr) );
006488 pCol->pTab = pExpr->y.pTab;
006489 pCol->iTable = pExpr->iTable;
006490 pCol->iColumn = pExpr->iColumn;
006491 pCol->iSorterColumn = -1;
006492 pCol->pCExpr = pExpr;
006493 if( pAggInfo->pGroupBy && pExpr->op!=TK_IF_NULL_ROW ){
006494 int j, n;
006495 ExprList *pGB = pAggInfo->pGroupBy;
006496 struct ExprList_item *pTerm = pGB->a;
006497 n = pGB->nExpr;
006498 for(j=0; j<n; j++, pTerm++){
006499 Expr *pE = pTerm->pExpr;
006500 if( pE->op==TK_COLUMN
006501 && pE->iTable==pExpr->iTable
006502 && pE->iColumn==pExpr->iColumn
006503 ){
006504 pCol->iSorterColumn = j;
006505 break;
006506 }
006507 }
006508 }
006509 if( pCol->iSorterColumn<0 ){
006510 pCol->iSorterColumn = pAggInfo->nSortingColumn++;
006511 }
006512 fix_up_expr:
006513 ExprSetVVAProperty(pExpr, EP_NoReduce);
006514 assert( pExpr->pAggInfo==0 || pExpr->pAggInfo==pAggInfo );
006515 pExpr->pAggInfo = pAggInfo;
006516 if( pExpr->op==TK_COLUMN ){
006517 pExpr->op = TK_AGG_COLUMN;
006518 }
006519 pExpr->iAgg = (i16)k;
006520 }
006521
006522 /*
006523 ** This is the xExprCallback for a tree walker. It is used to
006524 ** implement sqlite3ExprAnalyzeAggregates(). See sqlite3ExprAnalyzeAggregates
006525 ** for additional information.
006526 */
006527 static int analyzeAggregate(Walker *pWalker, Expr *pExpr){
006528 int i;
006529 NameContext *pNC = pWalker->u.pNC;
006530 Parse *pParse = pNC->pParse;
006531 SrcList *pSrcList = pNC->pSrcList;
006532 AggInfo *pAggInfo = pNC->uNC.pAggInfo;
006533
006534 assert( pNC->ncFlags & NC_UAggInfo );
006535 assert( pAggInfo->iFirstReg==0 );
006536 switch( pExpr->op ){
006537 default: {
006538 IndexedExpr *pIEpr;
006539 Expr tmp;
006540 assert( pParse->iSelfTab==0 );
006541 if( (pNC->ncFlags & NC_InAggFunc)==0 ) break;
006542 if( pParse->pIdxEpr==0 ) break;
006543 for(pIEpr=pParse->pIdxEpr; pIEpr; pIEpr=pIEpr->pIENext){
006544 int iDataCur = pIEpr->iDataCur;
006545 if( iDataCur<0 ) continue;
006546 if( sqlite3ExprCompare(0, pExpr, pIEpr->pExpr, iDataCur)==0 ) break;
006547 }
006548 if( pIEpr==0 ) break;
006549 if( NEVER(!ExprUseYTab(pExpr)) ) break;
006550 for(i=0; i<pSrcList->nSrc; i++){
006551 if( pSrcList->a[0].iCursor==pIEpr->iDataCur ) break;
006552 }
006553 if( i>=pSrcList->nSrc ) break;
006554 if( NEVER(pExpr->pAggInfo!=0) ) break; /* Resolved by outer context */
006555 if( pParse->nErr ){ return WRC_Abort; }
006556
006557 /* If we reach this point, it means that expression pExpr can be
006558 ** translated into a reference to an index column as described by
006559 ** pIEpr.
006560 */
006561 memset(&tmp, 0, sizeof(tmp));
006562 tmp.op = TK_AGG_COLUMN;
006563 tmp.iTable = pIEpr->iIdxCur;
006564 tmp.iColumn = pIEpr->iIdxCol;
006565 findOrCreateAggInfoColumn(pParse, pAggInfo, &tmp);
006566 if( pParse->nErr ){ return WRC_Abort; }
006567 assert( pAggInfo->aCol!=0 );
006568 assert( tmp.iAgg<pAggInfo->nColumn );
006569 pAggInfo->aCol[tmp.iAgg].pCExpr = pExpr;
006570 pExpr->pAggInfo = pAggInfo;
006571 pExpr->iAgg = tmp.iAgg;
006572 return WRC_Prune;
006573 }
006574 case TK_IF_NULL_ROW:
006575 case TK_AGG_COLUMN:
006576 case TK_COLUMN: {
006577 testcase( pExpr->op==TK_AGG_COLUMN );
006578 testcase( pExpr->op==TK_COLUMN );
006579 testcase( pExpr->op==TK_IF_NULL_ROW );
006580 /* Check to see if the column is in one of the tables in the FROM
006581 ** clause of the aggregate query */
006582 if( ALWAYS(pSrcList!=0) ){
006583 SrcItem *pItem = pSrcList->a;
006584 for(i=0; i<pSrcList->nSrc; i++, pItem++){
006585 assert( !ExprHasProperty(pExpr, EP_TokenOnly|EP_Reduced) );
006586 if( pExpr->iTable==pItem->iCursor ){
006587 findOrCreateAggInfoColumn(pParse, pAggInfo, pExpr);
006588 break;
006589 } /* endif pExpr->iTable==pItem->iCursor */
006590 } /* end loop over pSrcList */
006591 }
006592 return WRC_Continue;
006593 }
006594 case TK_AGG_FUNCTION: {
006595 if( (pNC->ncFlags & NC_InAggFunc)==0
006596 && pWalker->walkerDepth==pExpr->op2
006597 ){
006598 /* Check to see if pExpr is a duplicate of another aggregate
006599 ** function that is already in the pAggInfo structure
006600 */
006601 struct AggInfo_func *pItem = pAggInfo->aFunc;
006602 for(i=0; i<pAggInfo->nFunc; i++, pItem++){
006603 if( pItem->pFExpr==pExpr ) break;
006604 if( sqlite3ExprCompare(0, pItem->pFExpr, pExpr, -1)==0 ){
006605 break;
006606 }
006607 }
006608 if( i>=pAggInfo->nFunc ){
006609 /* pExpr is original. Make a new entry in pAggInfo->aFunc[]
006610 */
006611 u8 enc = ENC(pParse->db);
006612 i = addAggInfoFunc(pParse->db, pAggInfo);
006613 if( i>=0 ){
006614 assert( !ExprHasProperty(pExpr, EP_xIsSelect) );
006615 pItem = &pAggInfo->aFunc[i];
006616 pItem->pFExpr = pExpr;
006617 assert( ExprUseUToken(pExpr) );
006618 pItem->pFunc = sqlite3FindFunction(pParse->db,
006619 pExpr->u.zToken,
006620 pExpr->x.pList ? pExpr->x.pList->nExpr : 0, enc, 0);
006621 if( pExpr->flags & EP_Distinct ){
006622 pItem->iDistinct = pParse->nTab++;
006623 }else{
006624 pItem->iDistinct = -1;
006625 }
006626 }
006627 }
006628 /* Make pExpr point to the appropriate pAggInfo->aFunc[] entry
006629 */
006630 assert( !ExprHasProperty(pExpr, EP_TokenOnly|EP_Reduced) );
006631 ExprSetVVAProperty(pExpr, EP_NoReduce);
006632 pExpr->iAgg = (i16)i;
006633 pExpr->pAggInfo = pAggInfo;
006634 return WRC_Prune;
006635 }else{
006636 return WRC_Continue;
006637 }
006638 }
006639 }
006640 return WRC_Continue;
006641 }
006642
006643 /*
006644 ** Analyze the pExpr expression looking for aggregate functions and
006645 ** for variables that need to be added to AggInfo object that pNC->pAggInfo
006646 ** points to. Additional entries are made on the AggInfo object as
006647 ** necessary.
006648 **
006649 ** This routine should only be called after the expression has been
006650 ** analyzed by sqlite3ResolveExprNames().
006651 */
006652 void sqlite3ExprAnalyzeAggregates(NameContext *pNC, Expr *pExpr){
006653 Walker w;
006654 w.xExprCallback = analyzeAggregate;
006655 w.xSelectCallback = sqlite3WalkerDepthIncrease;
006656 w.xSelectCallback2 = sqlite3WalkerDepthDecrease;
006657 w.walkerDepth = 0;
006658 w.u.pNC = pNC;
006659 w.pParse = 0;
006660 assert( pNC->pSrcList!=0 );
006661 sqlite3WalkExpr(&w, pExpr);
006662 }
006663
006664 /*
006665 ** Call sqlite3ExprAnalyzeAggregates() for every expression in an
006666 ** expression list. Return the number of errors.
006667 **
006668 ** If an error is found, the analysis is cut short.
006669 */
006670 void sqlite3ExprAnalyzeAggList(NameContext *pNC, ExprList *pList){
006671 struct ExprList_item *pItem;
006672 int i;
006673 if( pList ){
006674 for(pItem=pList->a, i=0; i<pList->nExpr; i++, pItem++){
006675 sqlite3ExprAnalyzeAggregates(pNC, pItem->pExpr);
006676 }
006677 }
006678 }
006679
006680 /*
006681 ** Allocate a single new register for use to hold some intermediate result.
006682 */
006683 int sqlite3GetTempReg(Parse *pParse){
006684 if( pParse->nTempReg==0 ){
006685 return ++pParse->nMem;
006686 }
006687 return pParse->aTempReg[--pParse->nTempReg];
006688 }
006689
006690 /*
006691 ** Deallocate a register, making available for reuse for some other
006692 ** purpose.
006693 */
006694 void sqlite3ReleaseTempReg(Parse *pParse, int iReg){
006695 if( iReg ){
006696 sqlite3VdbeReleaseRegisters(pParse, iReg, 1, 0, 0);
006697 if( pParse->nTempReg<ArraySize(pParse->aTempReg) ){
006698 pParse->aTempReg[pParse->nTempReg++] = iReg;
006699 }
006700 }
006701 }
006702
006703 /*
006704 ** Allocate or deallocate a block of nReg consecutive registers.
006705 */
006706 int sqlite3GetTempRange(Parse *pParse, int nReg){
006707 int i, n;
006708 if( nReg==1 ) return sqlite3GetTempReg(pParse);
006709 i = pParse->iRangeReg;
006710 n = pParse->nRangeReg;
006711 if( nReg<=n ){
006712 pParse->iRangeReg += nReg;
006713 pParse->nRangeReg -= nReg;
006714 }else{
006715 i = pParse->nMem+1;
006716 pParse->nMem += nReg;
006717 }
006718 return i;
006719 }
006720 void sqlite3ReleaseTempRange(Parse *pParse, int iReg, int nReg){
006721 if( nReg==1 ){
006722 sqlite3ReleaseTempReg(pParse, iReg);
006723 return;
006724 }
006725 sqlite3VdbeReleaseRegisters(pParse, iReg, nReg, 0, 0);
006726 if( nReg>pParse->nRangeReg ){
006727 pParse->nRangeReg = nReg;
006728 pParse->iRangeReg = iReg;
006729 }
006730 }
006731
006732 /*
006733 ** Mark all temporary registers as being unavailable for reuse.
006734 **
006735 ** Always invoke this procedure after coding a subroutine or co-routine
006736 ** that might be invoked from other parts of the code, to ensure that
006737 ** the sub/co-routine does not use registers in common with the code that
006738 ** invokes the sub/co-routine.
006739 */
006740 void sqlite3ClearTempRegCache(Parse *pParse){
006741 pParse->nTempReg = 0;
006742 pParse->nRangeReg = 0;
006743 }
006744
006745 /*
006746 ** Make sure sufficient registers have been allocated so that
006747 ** iReg is a valid register number.
006748 */
006749 void sqlite3TouchRegister(Parse *pParse, int iReg){
006750 if( pParse->nMem<iReg ) pParse->nMem = iReg;
006751 }
006752
006753 #if defined(SQLITE_ENABLE_STAT4) || defined(SQLITE_DEBUG)
006754 /*
006755 ** Return the latest reusable register in the set of all registers.
006756 ** The value returned is no less than iMin. If any register iMin or
006757 ** greater is in permanent use, then return one more than that last
006758 ** permanent register.
006759 */
006760 int sqlite3FirstAvailableRegister(Parse *pParse, int iMin){
006761 const ExprList *pList = pParse->pConstExpr;
006762 if( pList ){
006763 int i;
006764 for(i=0; i<pList->nExpr; i++){
006765 if( pList->a[i].u.iConstExprReg>=iMin ){
006766 iMin = pList->a[i].u.iConstExprReg + 1;
006767 }
006768 }
006769 }
006770 pParse->nTempReg = 0;
006771 pParse->nRangeReg = 0;
006772 return iMin;
006773 }
006774 #endif /* SQLITE_ENABLE_STAT4 || SQLITE_DEBUG */
006775
006776 /*
006777 ** Validate that no temporary register falls within the range of
006778 ** iFirst..iLast, inclusive. This routine is only call from within assert()
006779 ** statements.
006780 */
006781 #ifdef SQLITE_DEBUG
006782 int sqlite3NoTempsInRange(Parse *pParse, int iFirst, int iLast){
006783 int i;
006784 if( pParse->nRangeReg>0
006785 && pParse->iRangeReg+pParse->nRangeReg > iFirst
006786 && pParse->iRangeReg <= iLast
006787 ){
006788 return 0;
006789 }
006790 for(i=0; i<pParse->nTempReg; i++){
006791 if( pParse->aTempReg[i]>=iFirst && pParse->aTempReg[i]<=iLast ){
006792 return 0;
006793 }
006794 }
006795 if( pParse->pConstExpr ){
006796 ExprList *pList = pParse->pConstExpr;
006797 for(i=0; i<pList->nExpr; i++){
006798 int iReg = pList->a[i].u.iConstExprReg;
006799 if( iReg==0 ) continue;
006800 if( iReg>=iFirst && iReg<=iLast ) return 0;
006801 }
006802 }
006803 return 1;
006804 }
006805 #endif /* SQLITE_DEBUG */