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 ExprSetProperty(pRet, EP_FullSize);
000595 pRet->iTable = nField;
000596 pRet->iColumn = iField;
000597 pRet->pLeft = pVector;
000598 }
000599 }else{
000600 if( pVector->op==TK_VECTOR ){
000601 Expr **ppVector;
000602 assert( ExprUseXList(pVector) );
000603 ppVector = &pVector->x.pList->a[iField].pExpr;
000604 pVector = *ppVector;
000605 if( IN_RENAME_OBJECT ){
000606 /* This must be a vector UPDATE inside a trigger */
000607 *ppVector = 0;
000608 return pVector;
000609 }
000610 }
000611 pRet = sqlite3ExprDup(pParse->db, pVector, 0);
000612 }
000613 return pRet;
000614 }
000615
000616 /*
000617 ** If expression pExpr is of type TK_SELECT, generate code to evaluate
000618 ** it. Return the register in which the result is stored (or, if the
000619 ** sub-select returns more than one column, the first in an array
000620 ** of registers in which the result is stored).
000621 **
000622 ** If pExpr is not a TK_SELECT expression, return 0.
000623 */
000624 static int exprCodeSubselect(Parse *pParse, Expr *pExpr){
000625 int reg = 0;
000626 #ifndef SQLITE_OMIT_SUBQUERY
000627 if( pExpr->op==TK_SELECT ){
000628 reg = sqlite3CodeSubselect(pParse, pExpr);
000629 }
000630 #endif
000631 return reg;
000632 }
000633
000634 /*
000635 ** Argument pVector points to a vector expression - either a TK_VECTOR
000636 ** or TK_SELECT that returns more than one column. This function returns
000637 ** the register number of a register that contains the value of
000638 ** element iField of the vector.
000639 **
000640 ** If pVector is a TK_SELECT expression, then code for it must have
000641 ** already been generated using the exprCodeSubselect() routine. In this
000642 ** case parameter regSelect should be the first in an array of registers
000643 ** containing the results of the sub-select.
000644 **
000645 ** If pVector is of type TK_VECTOR, then code for the requested field
000646 ** is generated. In this case (*pRegFree) may be set to the number of
000647 ** a temporary register to be freed by the caller before returning.
000648 **
000649 ** Before returning, output parameter (*ppExpr) is set to point to the
000650 ** Expr object corresponding to element iElem of the vector.
000651 */
000652 static int exprVectorRegister(
000653 Parse *pParse, /* Parse context */
000654 Expr *pVector, /* Vector to extract element from */
000655 int iField, /* Field to extract from pVector */
000656 int regSelect, /* First in array of registers */
000657 Expr **ppExpr, /* OUT: Expression element */
000658 int *pRegFree /* OUT: Temp register to free */
000659 ){
000660 u8 op = pVector->op;
000661 assert( op==TK_VECTOR || op==TK_REGISTER || op==TK_SELECT || op==TK_ERROR );
000662 if( op==TK_REGISTER ){
000663 *ppExpr = sqlite3VectorFieldSubexpr(pVector, iField);
000664 return pVector->iTable+iField;
000665 }
000666 if( op==TK_SELECT ){
000667 assert( ExprUseXSelect(pVector) );
000668 *ppExpr = pVector->x.pSelect->pEList->a[iField].pExpr;
000669 return regSelect+iField;
000670 }
000671 if( op==TK_VECTOR ){
000672 assert( ExprUseXList(pVector) );
000673 *ppExpr = pVector->x.pList->a[iField].pExpr;
000674 return sqlite3ExprCodeTemp(pParse, *ppExpr, pRegFree);
000675 }
000676 return 0;
000677 }
000678
000679 /*
000680 ** Expression pExpr is a comparison between two vector values. Compute
000681 ** the result of the comparison (1, 0, or NULL) and write that
000682 ** result into register dest.
000683 **
000684 ** The caller must satisfy the following preconditions:
000685 **
000686 ** if pExpr->op==TK_IS: op==TK_EQ and p5==SQLITE_NULLEQ
000687 ** if pExpr->op==TK_ISNOT: op==TK_NE and p5==SQLITE_NULLEQ
000688 ** otherwise: op==pExpr->op and p5==0
000689 */
000690 static void codeVectorCompare(
000691 Parse *pParse, /* Code generator context */
000692 Expr *pExpr, /* The comparison operation */
000693 int dest, /* Write results into this register */
000694 u8 op, /* Comparison operator */
000695 u8 p5 /* SQLITE_NULLEQ or zero */
000696 ){
000697 Vdbe *v = pParse->pVdbe;
000698 Expr *pLeft = pExpr->pLeft;
000699 Expr *pRight = pExpr->pRight;
000700 int nLeft = sqlite3ExprVectorSize(pLeft);
000701 int i;
000702 int regLeft = 0;
000703 int regRight = 0;
000704 u8 opx = op;
000705 int addrCmp = 0;
000706 int addrDone = sqlite3VdbeMakeLabel(pParse);
000707 int isCommuted = ExprHasProperty(pExpr,EP_Commuted);
000708
000709 assert( !ExprHasVVAProperty(pExpr,EP_Immutable) );
000710 if( pParse->nErr ) return;
000711 if( nLeft!=sqlite3ExprVectorSize(pRight) ){
000712 sqlite3ErrorMsg(pParse, "row value misused");
000713 return;
000714 }
000715 assert( pExpr->op==TK_EQ || pExpr->op==TK_NE
000716 || pExpr->op==TK_IS || pExpr->op==TK_ISNOT
000717 || pExpr->op==TK_LT || pExpr->op==TK_GT
000718 || pExpr->op==TK_LE || pExpr->op==TK_GE
000719 );
000720 assert( pExpr->op==op || (pExpr->op==TK_IS && op==TK_EQ)
000721 || (pExpr->op==TK_ISNOT && op==TK_NE) );
000722 assert( p5==0 || pExpr->op!=op );
000723 assert( p5==SQLITE_NULLEQ || pExpr->op==op );
000724
000725 if( op==TK_LE ) opx = TK_LT;
000726 if( op==TK_GE ) opx = TK_GT;
000727 if( op==TK_NE ) opx = TK_EQ;
000728
000729 regLeft = exprCodeSubselect(pParse, pLeft);
000730 regRight = exprCodeSubselect(pParse, pRight);
000731
000732 sqlite3VdbeAddOp2(v, OP_Integer, 1, dest);
000733 for(i=0; 1 /*Loop exits by "break"*/; i++){
000734 int regFree1 = 0, regFree2 = 0;
000735 Expr *pL = 0, *pR = 0;
000736 int r1, r2;
000737 assert( i>=0 && i<nLeft );
000738 if( addrCmp ) sqlite3VdbeJumpHere(v, addrCmp);
000739 r1 = exprVectorRegister(pParse, pLeft, i, regLeft, &pL, ®Free1);
000740 r2 = exprVectorRegister(pParse, pRight, i, regRight, &pR, ®Free2);
000741 addrCmp = sqlite3VdbeCurrentAddr(v);
000742 codeCompare(pParse, pL, pR, opx, r1, r2, addrDone, p5, isCommuted);
000743 testcase(op==OP_Lt); VdbeCoverageIf(v,op==OP_Lt);
000744 testcase(op==OP_Le); VdbeCoverageIf(v,op==OP_Le);
000745 testcase(op==OP_Gt); VdbeCoverageIf(v,op==OP_Gt);
000746 testcase(op==OP_Ge); VdbeCoverageIf(v,op==OP_Ge);
000747 testcase(op==OP_Eq); VdbeCoverageIf(v,op==OP_Eq);
000748 testcase(op==OP_Ne); VdbeCoverageIf(v,op==OP_Ne);
000749 sqlite3ReleaseTempReg(pParse, regFree1);
000750 sqlite3ReleaseTempReg(pParse, regFree2);
000751 if( (opx==TK_LT || opx==TK_GT) && i<nLeft-1 ){
000752 addrCmp = sqlite3VdbeAddOp0(v, OP_ElseEq);
000753 testcase(opx==TK_LT); VdbeCoverageIf(v,opx==TK_LT);
000754 testcase(opx==TK_GT); VdbeCoverageIf(v,opx==TK_GT);
000755 }
000756 if( p5==SQLITE_NULLEQ ){
000757 sqlite3VdbeAddOp2(v, OP_Integer, 0, dest);
000758 }else{
000759 sqlite3VdbeAddOp3(v, OP_ZeroOrNull, r1, dest, r2);
000760 }
000761 if( i==nLeft-1 ){
000762 break;
000763 }
000764 if( opx==TK_EQ ){
000765 sqlite3VdbeAddOp2(v, OP_NotNull, dest, addrDone); VdbeCoverage(v);
000766 }else{
000767 assert( op==TK_LT || op==TK_GT || op==TK_LE || op==TK_GE );
000768 sqlite3VdbeAddOp2(v, OP_Goto, 0, addrDone);
000769 if( i==nLeft-2 ) opx = op;
000770 }
000771 }
000772 sqlite3VdbeJumpHere(v, addrCmp);
000773 sqlite3VdbeResolveLabel(v, addrDone);
000774 if( op==TK_NE ){
000775 sqlite3VdbeAddOp2(v, OP_Not, dest, dest);
000776 }
000777 }
000778
000779 #if SQLITE_MAX_EXPR_DEPTH>0
000780 /*
000781 ** Check that argument nHeight is less than or equal to the maximum
000782 ** expression depth allowed. If it is not, leave an error message in
000783 ** pParse.
000784 */
000785 int sqlite3ExprCheckHeight(Parse *pParse, int nHeight){
000786 int rc = SQLITE_OK;
000787 int mxHeight = pParse->db->aLimit[SQLITE_LIMIT_EXPR_DEPTH];
000788 if( nHeight>mxHeight ){
000789 sqlite3ErrorMsg(pParse,
000790 "Expression tree is too large (maximum depth %d)", mxHeight
000791 );
000792 rc = SQLITE_ERROR;
000793 }
000794 return rc;
000795 }
000796
000797 /* The following three functions, heightOfExpr(), heightOfExprList()
000798 ** and heightOfSelect(), are used to determine the maximum height
000799 ** of any expression tree referenced by the structure passed as the
000800 ** first argument.
000801 **
000802 ** If this maximum height is greater than the current value pointed
000803 ** to by pnHeight, the second parameter, then set *pnHeight to that
000804 ** value.
000805 */
000806 static void heightOfExpr(const Expr *p, int *pnHeight){
000807 if( p ){
000808 if( p->nHeight>*pnHeight ){
000809 *pnHeight = p->nHeight;
000810 }
000811 }
000812 }
000813 static void heightOfExprList(const ExprList *p, int *pnHeight){
000814 if( p ){
000815 int i;
000816 for(i=0; i<p->nExpr; i++){
000817 heightOfExpr(p->a[i].pExpr, pnHeight);
000818 }
000819 }
000820 }
000821 static void heightOfSelect(const Select *pSelect, int *pnHeight){
000822 const Select *p;
000823 for(p=pSelect; p; p=p->pPrior){
000824 heightOfExpr(p->pWhere, pnHeight);
000825 heightOfExpr(p->pHaving, pnHeight);
000826 heightOfExpr(p->pLimit, pnHeight);
000827 heightOfExprList(p->pEList, pnHeight);
000828 heightOfExprList(p->pGroupBy, pnHeight);
000829 heightOfExprList(p->pOrderBy, pnHeight);
000830 }
000831 }
000832
000833 /*
000834 ** Set the Expr.nHeight variable in the structure passed as an
000835 ** argument. An expression with no children, Expr.pList or
000836 ** Expr.pSelect member has a height of 1. Any other expression
000837 ** has a height equal to the maximum height of any other
000838 ** referenced Expr plus one.
000839 **
000840 ** Also propagate EP_Propagate flags up from Expr.x.pList to Expr.flags,
000841 ** if appropriate.
000842 */
000843 static void exprSetHeight(Expr *p){
000844 int nHeight = p->pLeft ? p->pLeft->nHeight : 0;
000845 if( NEVER(p->pRight) && p->pRight->nHeight>nHeight ){
000846 nHeight = p->pRight->nHeight;
000847 }
000848 if( ExprUseXSelect(p) ){
000849 heightOfSelect(p->x.pSelect, &nHeight);
000850 }else if( p->x.pList ){
000851 heightOfExprList(p->x.pList, &nHeight);
000852 p->flags |= EP_Propagate & sqlite3ExprListFlags(p->x.pList);
000853 }
000854 p->nHeight = nHeight + 1;
000855 }
000856
000857 /*
000858 ** Set the Expr.nHeight variable using the exprSetHeight() function. If
000859 ** the height is greater than the maximum allowed expression depth,
000860 ** leave an error in pParse.
000861 **
000862 ** Also propagate all EP_Propagate flags from the Expr.x.pList into
000863 ** Expr.flags.
000864 */
000865 void sqlite3ExprSetHeightAndFlags(Parse *pParse, Expr *p){
000866 if( pParse->nErr ) return;
000867 exprSetHeight(p);
000868 sqlite3ExprCheckHeight(pParse, p->nHeight);
000869 }
000870
000871 /*
000872 ** Return the maximum height of any expression tree referenced
000873 ** by the select statement passed as an argument.
000874 */
000875 int sqlite3SelectExprHeight(const Select *p){
000876 int nHeight = 0;
000877 heightOfSelect(p, &nHeight);
000878 return nHeight;
000879 }
000880 #else /* ABOVE: Height enforcement enabled. BELOW: Height enforcement off */
000881 /*
000882 ** Propagate all EP_Propagate flags from the Expr.x.pList into
000883 ** Expr.flags.
000884 */
000885 void sqlite3ExprSetHeightAndFlags(Parse *pParse, Expr *p){
000886 if( pParse->nErr ) return;
000887 if( p && ExprUseXList(p) && p->x.pList ){
000888 p->flags |= EP_Propagate & sqlite3ExprListFlags(p->x.pList);
000889 }
000890 }
000891 #define exprSetHeight(y)
000892 #endif /* SQLITE_MAX_EXPR_DEPTH>0 */
000893
000894 /*
000895 ** Set the error offset for an Expr node, if possible.
000896 */
000897 void sqlite3ExprSetErrorOffset(Expr *pExpr, int iOfst){
000898 if( pExpr==0 ) return;
000899 if( NEVER(ExprUseWJoin(pExpr)) ) return;
000900 pExpr->w.iOfst = iOfst;
000901 }
000902
000903 /*
000904 ** This routine is the core allocator for Expr nodes.
000905 **
000906 ** Construct a new expression node and return a pointer to it. Memory
000907 ** for this node and for the pToken argument is a single allocation
000908 ** obtained from sqlite3DbMalloc(). The calling function
000909 ** is responsible for making sure the node eventually gets freed.
000910 **
000911 ** If dequote is true, then the token (if it exists) is dequoted.
000912 ** If dequote is false, no dequoting is performed. The deQuote
000913 ** parameter is ignored if pToken is NULL or if the token does not
000914 ** appear to be quoted. If the quotes were of the form "..." (double-quotes)
000915 ** then the EP_DblQuoted flag is set on the expression node.
000916 **
000917 ** Special case: If op==TK_INTEGER and pToken points to a string that
000918 ** can be translated into a 32-bit integer, then the token is not
000919 ** stored in u.zToken. Instead, the integer values is written
000920 ** into u.iValue and the EP_IntValue flag is set. No extra storage
000921 ** is allocated to hold the integer text and the dequote flag is ignored.
000922 */
000923 Expr *sqlite3ExprAlloc(
000924 sqlite3 *db, /* Handle for sqlite3DbMallocRawNN() */
000925 int op, /* Expression opcode */
000926 const Token *pToken, /* Token argument. Might be NULL */
000927 int dequote /* True to dequote */
000928 ){
000929 Expr *pNew;
000930 int nExtra = 0;
000931 int iValue = 0;
000932
000933 assert( db!=0 );
000934 if( pToken ){
000935 if( op!=TK_INTEGER || pToken->z==0
000936 || sqlite3GetInt32(pToken->z, &iValue)==0 ){
000937 nExtra = pToken->n+1;
000938 assert( iValue>=0 );
000939 }
000940 }
000941 pNew = sqlite3DbMallocRawNN(db, sizeof(Expr)+nExtra);
000942 if( pNew ){
000943 memset(pNew, 0, sizeof(Expr));
000944 pNew->op = (u8)op;
000945 pNew->iAgg = -1;
000946 if( pToken ){
000947 if( nExtra==0 ){
000948 pNew->flags |= EP_IntValue|EP_Leaf|(iValue?EP_IsTrue:EP_IsFalse);
000949 pNew->u.iValue = iValue;
000950 }else{
000951 pNew->u.zToken = (char*)&pNew[1];
000952 assert( pToken->z!=0 || pToken->n==0 );
000953 if( pToken->n ) memcpy(pNew->u.zToken, pToken->z, pToken->n);
000954 pNew->u.zToken[pToken->n] = 0;
000955 if( dequote && sqlite3Isquote(pNew->u.zToken[0]) ){
000956 sqlite3DequoteExpr(pNew);
000957 }
000958 }
000959 }
000960 #if SQLITE_MAX_EXPR_DEPTH>0
000961 pNew->nHeight = 1;
000962 #endif
000963 }
000964 return pNew;
000965 }
000966
000967 /*
000968 ** Allocate a new expression node from a zero-terminated token that has
000969 ** already been dequoted.
000970 */
000971 Expr *sqlite3Expr(
000972 sqlite3 *db, /* Handle for sqlite3DbMallocZero() (may be null) */
000973 int op, /* Expression opcode */
000974 const char *zToken /* Token argument. Might be NULL */
000975 ){
000976 Token x;
000977 x.z = zToken;
000978 x.n = sqlite3Strlen30(zToken);
000979 return sqlite3ExprAlloc(db, op, &x, 0);
000980 }
000981
000982 /*
000983 ** Attach subtrees pLeft and pRight to the Expr node pRoot.
000984 **
000985 ** If pRoot==NULL that means that a memory allocation error has occurred.
000986 ** In that case, delete the subtrees pLeft and pRight.
000987 */
000988 void sqlite3ExprAttachSubtrees(
000989 sqlite3 *db,
000990 Expr *pRoot,
000991 Expr *pLeft,
000992 Expr *pRight
000993 ){
000994 if( pRoot==0 ){
000995 assert( db->mallocFailed );
000996 sqlite3ExprDelete(db, pLeft);
000997 sqlite3ExprDelete(db, pRight);
000998 }else{
000999 assert( ExprUseXList(pRoot) );
001000 assert( pRoot->x.pSelect==0 );
001001 if( pRight ){
001002 pRoot->pRight = pRight;
001003 pRoot->flags |= EP_Propagate & pRight->flags;
001004 #if SQLITE_MAX_EXPR_DEPTH>0
001005 pRoot->nHeight = pRight->nHeight+1;
001006 }else{
001007 pRoot->nHeight = 1;
001008 #endif
001009 }
001010 if( pLeft ){
001011 pRoot->pLeft = pLeft;
001012 pRoot->flags |= EP_Propagate & pLeft->flags;
001013 #if SQLITE_MAX_EXPR_DEPTH>0
001014 if( pLeft->nHeight>=pRoot->nHeight ){
001015 pRoot->nHeight = pLeft->nHeight+1;
001016 }
001017 #endif
001018 }
001019 }
001020 }
001021
001022 /*
001023 ** Allocate an Expr node which joins as many as two subtrees.
001024 **
001025 ** One or both of the subtrees can be NULL. Return a pointer to the new
001026 ** Expr node. Or, if an OOM error occurs, set pParse->db->mallocFailed,
001027 ** free the subtrees and return NULL.
001028 */
001029 Expr *sqlite3PExpr(
001030 Parse *pParse, /* Parsing context */
001031 int op, /* Expression opcode */
001032 Expr *pLeft, /* Left operand */
001033 Expr *pRight /* Right operand */
001034 ){
001035 Expr *p;
001036 p = sqlite3DbMallocRawNN(pParse->db, sizeof(Expr));
001037 if( p ){
001038 memset(p, 0, sizeof(Expr));
001039 p->op = op & 0xff;
001040 p->iAgg = -1;
001041 sqlite3ExprAttachSubtrees(pParse->db, p, pLeft, pRight);
001042 sqlite3ExprCheckHeight(pParse, p->nHeight);
001043 }else{
001044 sqlite3ExprDelete(pParse->db, pLeft);
001045 sqlite3ExprDelete(pParse->db, pRight);
001046 }
001047 return p;
001048 }
001049
001050 /*
001051 ** Add pSelect to the Expr.x.pSelect field. Or, if pExpr is NULL (due
001052 ** do a memory allocation failure) then delete the pSelect object.
001053 */
001054 void sqlite3PExprAddSelect(Parse *pParse, Expr *pExpr, Select *pSelect){
001055 if( pExpr ){
001056 pExpr->x.pSelect = pSelect;
001057 ExprSetProperty(pExpr, EP_xIsSelect|EP_Subquery);
001058 sqlite3ExprSetHeightAndFlags(pParse, pExpr);
001059 }else{
001060 assert( pParse->db->mallocFailed );
001061 sqlite3SelectDelete(pParse->db, pSelect);
001062 }
001063 }
001064
001065 /*
001066 ** Expression list pEList is a list of vector values. This function
001067 ** converts the contents of pEList to a VALUES(...) Select statement
001068 ** returning 1 row for each element of the list. For example, the
001069 ** expression list:
001070 **
001071 ** ( (1,2), (3,4) (5,6) )
001072 **
001073 ** is translated to the equivalent of:
001074 **
001075 ** VALUES(1,2), (3,4), (5,6)
001076 **
001077 ** Each of the vector values in pEList must contain exactly nElem terms.
001078 ** If a list element that is not a vector or does not contain nElem terms,
001079 ** an error message is left in pParse.
001080 **
001081 ** This is used as part of processing IN(...) expressions with a list
001082 ** of vectors on the RHS. e.g. "... IN ((1,2), (3,4), (5,6))".
001083 */
001084 Select *sqlite3ExprListToValues(Parse *pParse, int nElem, ExprList *pEList){
001085 int ii;
001086 Select *pRet = 0;
001087 assert( nElem>1 );
001088 for(ii=0; ii<pEList->nExpr; ii++){
001089 Select *pSel;
001090 Expr *pExpr = pEList->a[ii].pExpr;
001091 int nExprElem;
001092 if( pExpr->op==TK_VECTOR ){
001093 assert( ExprUseXList(pExpr) );
001094 nExprElem = pExpr->x.pList->nExpr;
001095 }else{
001096 nExprElem = 1;
001097 }
001098 if( nExprElem!=nElem ){
001099 sqlite3ErrorMsg(pParse, "IN(...) element has %d term%s - expected %d",
001100 nExprElem, nExprElem>1?"s":"", nElem
001101 );
001102 break;
001103 }
001104 assert( ExprUseXList(pExpr) );
001105 pSel = sqlite3SelectNew(pParse, pExpr->x.pList, 0, 0, 0, 0, 0, SF_Values,0);
001106 pExpr->x.pList = 0;
001107 if( pSel ){
001108 if( pRet ){
001109 pSel->op = TK_ALL;
001110 pSel->pPrior = pRet;
001111 }
001112 pRet = pSel;
001113 }
001114 }
001115
001116 if( pRet && pRet->pPrior ){
001117 pRet->selFlags |= SF_MultiValue;
001118 }
001119 sqlite3ExprListDelete(pParse->db, pEList);
001120 return pRet;
001121 }
001122
001123 /*
001124 ** Join two expressions using an AND operator. If either expression is
001125 ** NULL, then just return the other expression.
001126 **
001127 ** If one side or the other of the AND is known to be false, and neither side
001128 ** is part of an ON clause, then instead of returning an AND expression,
001129 ** just return a constant expression with a value of false.
001130 */
001131 Expr *sqlite3ExprAnd(Parse *pParse, Expr *pLeft, Expr *pRight){
001132 sqlite3 *db = pParse->db;
001133 if( pLeft==0 ){
001134 return pRight;
001135 }else if( pRight==0 ){
001136 return pLeft;
001137 }else{
001138 u32 f = pLeft->flags | pRight->flags;
001139 if( (f&(EP_OuterON|EP_InnerON|EP_IsFalse))==EP_IsFalse
001140 && !IN_RENAME_OBJECT
001141 ){
001142 sqlite3ExprDeferredDelete(pParse, pLeft);
001143 sqlite3ExprDeferredDelete(pParse, pRight);
001144 return sqlite3Expr(db, TK_INTEGER, "0");
001145 }else{
001146 return sqlite3PExpr(pParse, TK_AND, pLeft, pRight);
001147 }
001148 }
001149 }
001150
001151 /*
001152 ** Construct a new expression node for a function with multiple
001153 ** arguments.
001154 */
001155 Expr *sqlite3ExprFunction(
001156 Parse *pParse, /* Parsing context */
001157 ExprList *pList, /* Argument list */
001158 const Token *pToken, /* Name of the function */
001159 int eDistinct /* SF_Distinct or SF_ALL or 0 */
001160 ){
001161 Expr *pNew;
001162 sqlite3 *db = pParse->db;
001163 assert( pToken );
001164 pNew = sqlite3ExprAlloc(db, TK_FUNCTION, pToken, 1);
001165 if( pNew==0 ){
001166 sqlite3ExprListDelete(db, pList); /* Avoid memory leak when malloc fails */
001167 return 0;
001168 }
001169 assert( !ExprHasProperty(pNew, EP_InnerON|EP_OuterON) );
001170 pNew->w.iOfst = (int)(pToken->z - pParse->zTail);
001171 if( pList
001172 && pList->nExpr > pParse->db->aLimit[SQLITE_LIMIT_FUNCTION_ARG]
001173 && !pParse->nested
001174 ){
001175 sqlite3ErrorMsg(pParse, "too many arguments on function %T", pToken);
001176 }
001177 pNew->x.pList = pList;
001178 ExprSetProperty(pNew, EP_HasFunc);
001179 assert( ExprUseXList(pNew) );
001180 sqlite3ExprSetHeightAndFlags(pParse, pNew);
001181 if( eDistinct==SF_Distinct ) ExprSetProperty(pNew, EP_Distinct);
001182 return pNew;
001183 }
001184
001185 /*
001186 ** Report an error when attempting to use an ORDER BY clause within
001187 ** the arguments of a non-aggregate function.
001188 */
001189 void sqlite3ExprOrderByAggregateError(Parse *pParse, Expr *p){
001190 sqlite3ErrorMsg(pParse,
001191 "ORDER BY may not be used with non-aggregate %#T()", p
001192 );
001193 }
001194
001195 /*
001196 ** Attach an ORDER BY clause to a function call.
001197 **
001198 ** functionname( arguments ORDER BY sortlist )
001199 ** \_____________________/ \______/
001200 ** pExpr pOrderBy
001201 **
001202 ** The ORDER BY clause is inserted into a new Expr node of type TK_ORDER
001203 ** and added to the Expr.pLeft field of the parent TK_FUNCTION node.
001204 */
001205 void sqlite3ExprAddFunctionOrderBy(
001206 Parse *pParse, /* Parsing context */
001207 Expr *pExpr, /* The function call to which ORDER BY is to be added */
001208 ExprList *pOrderBy /* The ORDER BY clause to add */
001209 ){
001210 Expr *pOB;
001211 sqlite3 *db = pParse->db;
001212 if( NEVER(pOrderBy==0) ){
001213 assert( db->mallocFailed );
001214 return;
001215 }
001216 if( pExpr==0 ){
001217 assert( db->mallocFailed );
001218 sqlite3ExprListDelete(db, pOrderBy);
001219 return;
001220 }
001221 assert( pExpr->op==TK_FUNCTION );
001222 assert( pExpr->pLeft==0 );
001223 assert( ExprUseXList(pExpr) );
001224 if( pExpr->x.pList==0 || NEVER(pExpr->x.pList->nExpr==0) ){
001225 /* Ignore ORDER BY on zero-argument aggregates */
001226 sqlite3ParserAddCleanup(pParse, sqlite3ExprListDeleteGeneric, pOrderBy);
001227 return;
001228 }
001229 if( IsWindowFunc(pExpr) ){
001230 sqlite3ExprOrderByAggregateError(pParse, pExpr);
001231 sqlite3ExprListDelete(db, pOrderBy);
001232 return;
001233 }
001234
001235 pOB = sqlite3ExprAlloc(db, TK_ORDER, 0, 0);
001236 if( pOB==0 ){
001237 sqlite3ExprListDelete(db, pOrderBy);
001238 return;
001239 }
001240 pOB->x.pList = pOrderBy;
001241 assert( ExprUseXList(pOB) );
001242 pExpr->pLeft = pOB;
001243 ExprSetProperty(pOB, EP_FullSize);
001244 }
001245
001246 /*
001247 ** Check to see if a function is usable according to current access
001248 ** rules:
001249 **
001250 ** SQLITE_FUNC_DIRECT - Only usable from top-level SQL
001251 **
001252 ** SQLITE_FUNC_UNSAFE - Usable if TRUSTED_SCHEMA or from
001253 ** top-level SQL
001254 **
001255 ** If the function is not usable, create an error.
001256 */
001257 void sqlite3ExprFunctionUsable(
001258 Parse *pParse, /* Parsing and code generating context */
001259 const Expr *pExpr, /* The function invocation */
001260 const FuncDef *pDef /* The function being invoked */
001261 ){
001262 assert( !IN_RENAME_OBJECT );
001263 assert( (pDef->funcFlags & (SQLITE_FUNC_DIRECT|SQLITE_FUNC_UNSAFE))!=0 );
001264 if( ExprHasProperty(pExpr, EP_FromDDL) ){
001265 if( (pDef->funcFlags & SQLITE_FUNC_DIRECT)!=0
001266 || (pParse->db->flags & SQLITE_TrustedSchema)==0
001267 ){
001268 /* Functions prohibited in triggers and views if:
001269 ** (1) tagged with SQLITE_DIRECTONLY
001270 ** (2) not tagged with SQLITE_INNOCUOUS (which means it
001271 ** is tagged with SQLITE_FUNC_UNSAFE) and
001272 ** SQLITE_DBCONFIG_TRUSTED_SCHEMA is off (meaning
001273 ** that the schema is possibly tainted).
001274 */
001275 sqlite3ErrorMsg(pParse, "unsafe use of %#T()", pExpr);
001276 }
001277 }
001278 }
001279
001280 /*
001281 ** Assign a variable number to an expression that encodes a wildcard
001282 ** in the original SQL statement.
001283 **
001284 ** Wildcards consisting of a single "?" are assigned the next sequential
001285 ** variable number.
001286 **
001287 ** Wildcards of the form "?nnn" are assigned the number "nnn". We make
001288 ** sure "nnn" is not too big to avoid a denial of service attack when
001289 ** the SQL statement comes from an external source.
001290 **
001291 ** Wildcards of the form ":aaa", "@aaa", or "$aaa" are assigned the same number
001292 ** as the previous instance of the same wildcard. Or if this is the first
001293 ** instance of the wildcard, the next sequential variable number is
001294 ** assigned.
001295 */
001296 void sqlite3ExprAssignVarNumber(Parse *pParse, Expr *pExpr, u32 n){
001297 sqlite3 *db = pParse->db;
001298 const char *z;
001299 ynVar x;
001300
001301 if( pExpr==0 ) return;
001302 assert( !ExprHasProperty(pExpr, EP_IntValue|EP_Reduced|EP_TokenOnly) );
001303 z = pExpr->u.zToken;
001304 assert( z!=0 );
001305 assert( z[0]!=0 );
001306 assert( n==(u32)sqlite3Strlen30(z) );
001307 if( z[1]==0 ){
001308 /* Wildcard of the form "?". Assign the next variable number */
001309 assert( z[0]=='?' );
001310 x = (ynVar)(++pParse->nVar);
001311 }else{
001312 int doAdd = 0;
001313 if( z[0]=='?' ){
001314 /* Wildcard of the form "?nnn". Convert "nnn" to an integer and
001315 ** use it as the variable number */
001316 i64 i;
001317 int bOk;
001318 if( n==2 ){ /*OPTIMIZATION-IF-TRUE*/
001319 i = z[1]-'0'; /* The common case of ?N for a single digit N */
001320 bOk = 1;
001321 }else{
001322 bOk = 0==sqlite3Atoi64(&z[1], &i, n-1, SQLITE_UTF8);
001323 }
001324 testcase( i==0 );
001325 testcase( i==1 );
001326 testcase( i==db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER]-1 );
001327 testcase( i==db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER] );
001328 if( bOk==0 || i<1 || i>db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER] ){
001329 sqlite3ErrorMsg(pParse, "variable number must be between ?1 and ?%d",
001330 db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER]);
001331 sqlite3RecordErrorOffsetOfExpr(pParse->db, pExpr);
001332 return;
001333 }
001334 x = (ynVar)i;
001335 if( x>pParse->nVar ){
001336 pParse->nVar = (int)x;
001337 doAdd = 1;
001338 }else if( sqlite3VListNumToName(pParse->pVList, x)==0 ){
001339 doAdd = 1;
001340 }
001341 }else{
001342 /* Wildcards like ":aaa", "$aaa" or "@aaa". Reuse the same variable
001343 ** number as the prior appearance of the same name, or if the name
001344 ** has never appeared before, reuse the same variable number
001345 */
001346 x = (ynVar)sqlite3VListNameToNum(pParse->pVList, z, n);
001347 if( x==0 ){
001348 x = (ynVar)(++pParse->nVar);
001349 doAdd = 1;
001350 }
001351 }
001352 if( doAdd ){
001353 pParse->pVList = sqlite3VListAdd(db, pParse->pVList, z, n, x);
001354 }
001355 }
001356 pExpr->iColumn = x;
001357 if( x>db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER] ){
001358 sqlite3ErrorMsg(pParse, "too many SQL variables");
001359 sqlite3RecordErrorOffsetOfExpr(pParse->db, pExpr);
001360 }
001361 }
001362
001363 /*
001364 ** Recursively delete an expression tree.
001365 */
001366 static SQLITE_NOINLINE void sqlite3ExprDeleteNN(sqlite3 *db, Expr *p){
001367 assert( p!=0 );
001368 assert( db!=0 );
001369 assert( !ExprUseUValue(p) || p->u.iValue>=0 );
001370 assert( !ExprUseYWin(p) || !ExprUseYSub(p) );
001371 assert( !ExprUseYWin(p) || p->y.pWin!=0 || db->mallocFailed );
001372 assert( p->op!=TK_FUNCTION || !ExprUseYSub(p) );
001373 #ifdef SQLITE_DEBUG
001374 if( ExprHasProperty(p, EP_Leaf) && !ExprHasProperty(p, EP_TokenOnly) ){
001375 assert( p->pLeft==0 );
001376 assert( p->pRight==0 );
001377 assert( !ExprUseXSelect(p) || p->x.pSelect==0 );
001378 assert( !ExprUseXList(p) || p->x.pList==0 );
001379 }
001380 #endif
001381 if( !ExprHasProperty(p, (EP_TokenOnly|EP_Leaf)) ){
001382 /* The Expr.x union is never used at the same time as Expr.pRight */
001383 assert( (ExprUseXList(p) && p->x.pList==0) || p->pRight==0 );
001384 if( p->pLeft && p->op!=TK_SELECT_COLUMN ) sqlite3ExprDeleteNN(db, p->pLeft);
001385 if( p->pRight ){
001386 assert( !ExprHasProperty(p, EP_WinFunc) );
001387 sqlite3ExprDeleteNN(db, p->pRight);
001388 }else if( ExprUseXSelect(p) ){
001389 assert( !ExprHasProperty(p, EP_WinFunc) );
001390 sqlite3SelectDelete(db, p->x.pSelect);
001391 }else{
001392 sqlite3ExprListDelete(db, p->x.pList);
001393 #ifndef SQLITE_OMIT_WINDOWFUNC
001394 if( ExprHasProperty(p, EP_WinFunc) ){
001395 sqlite3WindowDelete(db, p->y.pWin);
001396 }
001397 #endif
001398 }
001399 }
001400 if( !ExprHasProperty(p, EP_Static) ){
001401 sqlite3DbNNFreeNN(db, p);
001402 }
001403 }
001404 void sqlite3ExprDelete(sqlite3 *db, Expr *p){
001405 if( p ) sqlite3ExprDeleteNN(db, p);
001406 }
001407 void sqlite3ExprDeleteGeneric(sqlite3 *db, void *p){
001408 if( ALWAYS(p) ) sqlite3ExprDeleteNN(db, (Expr*)p);
001409 }
001410
001411 /*
001412 ** Clear both elements of an OnOrUsing object
001413 */
001414 void sqlite3ClearOnOrUsing(sqlite3 *db, OnOrUsing *p){
001415 if( p==0 ){
001416 /* Nothing to clear */
001417 }else if( p->pOn ){
001418 sqlite3ExprDeleteNN(db, p->pOn);
001419 }else if( p->pUsing ){
001420 sqlite3IdListDelete(db, p->pUsing);
001421 }
001422 }
001423
001424 /*
001425 ** Arrange to cause pExpr to be deleted when the pParse is deleted.
001426 ** This is similar to sqlite3ExprDelete() except that the delete is
001427 ** deferred until the pParse is deleted.
001428 **
001429 ** The pExpr might be deleted immediately on an OOM error.
001430 **
001431 ** The deferred delete is (currently) implemented by adding the
001432 ** pExpr to the pParse->pConstExpr list with a register number of 0.
001433 */
001434 void sqlite3ExprDeferredDelete(Parse *pParse, Expr *pExpr){
001435 sqlite3ParserAddCleanup(pParse, sqlite3ExprDeleteGeneric, pExpr);
001436 }
001437
001438 /* Invoke sqlite3RenameExprUnmap() and sqlite3ExprDelete() on the
001439 ** expression.
001440 */
001441 void sqlite3ExprUnmapAndDelete(Parse *pParse, Expr *p){
001442 if( p ){
001443 if( IN_RENAME_OBJECT ){
001444 sqlite3RenameExprUnmap(pParse, p);
001445 }
001446 sqlite3ExprDeleteNN(pParse->db, p);
001447 }
001448 }
001449
001450 /*
001451 ** Return the number of bytes allocated for the expression structure
001452 ** passed as the first argument. This is always one of EXPR_FULLSIZE,
001453 ** EXPR_REDUCEDSIZE or EXPR_TOKENONLYSIZE.
001454 */
001455 static int exprStructSize(const Expr *p){
001456 if( ExprHasProperty(p, EP_TokenOnly) ) return EXPR_TOKENONLYSIZE;
001457 if( ExprHasProperty(p, EP_Reduced) ) return EXPR_REDUCEDSIZE;
001458 return EXPR_FULLSIZE;
001459 }
001460
001461 /*
001462 ** The dupedExpr*Size() routines each return the number of bytes required
001463 ** to store a copy of an expression or expression tree. They differ in
001464 ** how much of the tree is measured.
001465 **
001466 ** dupedExprStructSize() Size of only the Expr structure
001467 ** dupedExprNodeSize() Size of Expr + space for token
001468 ** dupedExprSize() Expr + token + subtree components
001469 **
001470 ***************************************************************************
001471 **
001472 ** The dupedExprStructSize() function returns two values OR-ed together:
001473 ** (1) the space required for a copy of the Expr structure only and
001474 ** (2) the EP_xxx flags that indicate what the structure size should be.
001475 ** The return values is always one of:
001476 **
001477 ** EXPR_FULLSIZE
001478 ** EXPR_REDUCEDSIZE | EP_Reduced
001479 ** EXPR_TOKENONLYSIZE | EP_TokenOnly
001480 **
001481 ** The size of the structure can be found by masking the return value
001482 ** of this routine with 0xfff. The flags can be found by masking the
001483 ** return value with EP_Reduced|EP_TokenOnly.
001484 **
001485 ** Note that with flags==EXPRDUP_REDUCE, this routines works on full-size
001486 ** (unreduced) Expr objects as they or originally constructed by the parser.
001487 ** During expression analysis, extra information is computed and moved into
001488 ** later parts of the Expr object and that extra information might get chopped
001489 ** off if the expression is reduced. Note also that it does not work to
001490 ** make an EXPRDUP_REDUCE copy of a reduced expression. It is only legal
001491 ** to reduce a pristine expression tree from the parser. The implementation
001492 ** of dupedExprStructSize() contain multiple assert() statements that attempt
001493 ** to enforce this constraint.
001494 */
001495 static int dupedExprStructSize(const Expr *p, int flags){
001496 int nSize;
001497 assert( flags==EXPRDUP_REDUCE || flags==0 ); /* Only one flag value allowed */
001498 assert( EXPR_FULLSIZE<=0xfff );
001499 assert( (0xfff & (EP_Reduced|EP_TokenOnly))==0 );
001500 if( 0==flags || ExprHasProperty(p, EP_FullSize) ){
001501 nSize = EXPR_FULLSIZE;
001502 }else{
001503 assert( !ExprHasProperty(p, EP_TokenOnly|EP_Reduced) );
001504 assert( !ExprHasProperty(p, EP_OuterON) );
001505 assert( !ExprHasVVAProperty(p, EP_NoReduce) );
001506 if( p->pLeft || p->x.pList ){
001507 nSize = EXPR_REDUCEDSIZE | EP_Reduced;
001508 }else{
001509 assert( p->pRight==0 );
001510 nSize = EXPR_TOKENONLYSIZE | EP_TokenOnly;
001511 }
001512 }
001513 return nSize;
001514 }
001515
001516 /*
001517 ** This function returns the space in bytes required to store the copy
001518 ** of the Expr structure and a copy of the Expr.u.zToken string (if that
001519 ** string is defined.)
001520 */
001521 static int dupedExprNodeSize(const Expr *p, int flags){
001522 int nByte = dupedExprStructSize(p, flags) & 0xfff;
001523 if( !ExprHasProperty(p, EP_IntValue) && p->u.zToken ){
001524 nByte += sqlite3Strlen30NN(p->u.zToken)+1;
001525 }
001526 return ROUND8(nByte);
001527 }
001528
001529 /*
001530 ** Return the number of bytes required to create a duplicate of the
001531 ** expression passed as the first argument.
001532 **
001533 ** The value returned includes space to create a copy of the Expr struct
001534 ** itself and the buffer referred to by Expr.u.zToken, if any.
001535 **
001536 ** The return value includes space to duplicate all Expr nodes in the
001537 ** tree formed by Expr.pLeft and Expr.pRight, but not any other
001538 ** substructure such as Expr.x.pList, Expr.x.pSelect, and Expr.y.pWin.
001539 */
001540 static int dupedExprSize(const Expr *p){
001541 int nByte;
001542 assert( p!=0 );
001543 nByte = dupedExprNodeSize(p, EXPRDUP_REDUCE);
001544 if( p->pLeft ) nByte += dupedExprSize(p->pLeft);
001545 if( p->pRight ) nByte += dupedExprSize(p->pRight);
001546 assert( nByte==ROUND8(nByte) );
001547 return nByte;
001548 }
001549
001550 /*
001551 ** An EdupBuf is a memory allocation used to stored multiple Expr objects
001552 ** together with their Expr.zToken content. This is used to help implement
001553 ** compression while doing sqlite3ExprDup(). The top-level Expr does the
001554 ** allocation for itself and many of its decendents, then passes an instance
001555 ** of the structure down into exprDup() so that they decendents can have
001556 ** access to that memory.
001557 */
001558 typedef struct EdupBuf EdupBuf;
001559 struct EdupBuf {
001560 u8 *zAlloc; /* Memory space available for storage */
001561 #ifdef SQLITE_DEBUG
001562 u8 *zEnd; /* First byte past the end of memory */
001563 #endif
001564 };
001565
001566 /*
001567 ** This function is similar to sqlite3ExprDup(), except that if pEdupBuf
001568 ** is not NULL then it points to memory that can be used to store a copy
001569 ** of the input Expr p together with its p->u.zToken (if any). pEdupBuf
001570 ** is updated with the new buffer tail prior to returning.
001571 */
001572 static Expr *exprDup(
001573 sqlite3 *db, /* Database connection (for memory allocation) */
001574 const Expr *p, /* Expr tree to be duplicated */
001575 int dupFlags, /* EXPRDUP_REDUCE for compression. 0 if not */
001576 EdupBuf *pEdupBuf /* Preallocated storage space, or NULL */
001577 ){
001578 Expr *pNew; /* Value to return */
001579 EdupBuf sEdupBuf; /* Memory space from which to build Expr object */
001580 u32 staticFlag; /* EP_Static if space not obtained from malloc */
001581 int nToken = -1; /* Space needed for p->u.zToken. -1 means unknown */
001582
001583 assert( db!=0 );
001584 assert( p );
001585 assert( dupFlags==0 || dupFlags==EXPRDUP_REDUCE );
001586 assert( pEdupBuf==0 || dupFlags==EXPRDUP_REDUCE );
001587
001588 /* Figure out where to write the new Expr structure. */
001589 if( pEdupBuf ){
001590 sEdupBuf.zAlloc = pEdupBuf->zAlloc;
001591 #ifdef SQLITE_DEBUG
001592 sEdupBuf.zEnd = pEdupBuf->zEnd;
001593 #endif
001594 staticFlag = EP_Static;
001595 assert( sEdupBuf.zAlloc!=0 );
001596 assert( dupFlags==EXPRDUP_REDUCE );
001597 }else{
001598 int nAlloc;
001599 if( dupFlags ){
001600 nAlloc = dupedExprSize(p);
001601 }else if( !ExprHasProperty(p, EP_IntValue) && p->u.zToken ){
001602 nToken = sqlite3Strlen30NN(p->u.zToken)+1;
001603 nAlloc = ROUND8(EXPR_FULLSIZE + nToken);
001604 }else{
001605 nToken = 0;
001606 nAlloc = ROUND8(EXPR_FULLSIZE);
001607 }
001608 assert( nAlloc==ROUND8(nAlloc) );
001609 sEdupBuf.zAlloc = sqlite3DbMallocRawNN(db, nAlloc);
001610 #ifdef SQLITE_DEBUG
001611 sEdupBuf.zEnd = sEdupBuf.zAlloc ? sEdupBuf.zAlloc+nAlloc : 0;
001612 #endif
001613
001614 staticFlag = 0;
001615 }
001616 pNew = (Expr *)sEdupBuf.zAlloc;
001617 assert( EIGHT_BYTE_ALIGNMENT(pNew) );
001618
001619 if( pNew ){
001620 /* Set nNewSize to the size allocated for the structure pointed to
001621 ** by pNew. This is either EXPR_FULLSIZE, EXPR_REDUCEDSIZE or
001622 ** EXPR_TOKENONLYSIZE. nToken is set to the number of bytes consumed
001623 ** by the copy of the p->u.zToken string (if any).
001624 */
001625 const unsigned nStructSize = dupedExprStructSize(p, dupFlags);
001626 int nNewSize = nStructSize & 0xfff;
001627 if( nToken<0 ){
001628 if( !ExprHasProperty(p, EP_IntValue) && p->u.zToken ){
001629 nToken = sqlite3Strlen30(p->u.zToken) + 1;
001630 }else{
001631 nToken = 0;
001632 }
001633 }
001634 if( dupFlags ){
001635 assert( (int)(sEdupBuf.zEnd - sEdupBuf.zAlloc) >= nNewSize+nToken );
001636 assert( ExprHasProperty(p, EP_Reduced)==0 );
001637 memcpy(sEdupBuf.zAlloc, p, nNewSize);
001638 }else{
001639 u32 nSize = (u32)exprStructSize(p);
001640 assert( (int)(sEdupBuf.zEnd - sEdupBuf.zAlloc) >=
001641 (int)EXPR_FULLSIZE+nToken );
001642 memcpy(sEdupBuf.zAlloc, p, nSize);
001643 if( nSize<EXPR_FULLSIZE ){
001644 memset(&sEdupBuf.zAlloc[nSize], 0, EXPR_FULLSIZE-nSize);
001645 }
001646 nNewSize = EXPR_FULLSIZE;
001647 }
001648
001649 /* Set the EP_Reduced, EP_TokenOnly, and EP_Static flags appropriately. */
001650 pNew->flags &= ~(EP_Reduced|EP_TokenOnly|EP_Static);
001651 pNew->flags |= nStructSize & (EP_Reduced|EP_TokenOnly);
001652 pNew->flags |= staticFlag;
001653 ExprClearVVAProperties(pNew);
001654 if( dupFlags ){
001655 ExprSetVVAProperty(pNew, EP_Immutable);
001656 }
001657
001658 /* Copy the p->u.zToken string, if any. */
001659 assert( nToken>=0 );
001660 if( nToken>0 ){
001661 char *zToken = pNew->u.zToken = (char*)&sEdupBuf.zAlloc[nNewSize];
001662 memcpy(zToken, p->u.zToken, nToken);
001663 nNewSize += nToken;
001664 }
001665 sEdupBuf.zAlloc += ROUND8(nNewSize);
001666
001667 if( ((p->flags|pNew->flags)&(EP_TokenOnly|EP_Leaf))==0 ){
001668
001669 /* Fill in the pNew->x.pSelect or pNew->x.pList member. */
001670 if( ExprUseXSelect(p) ){
001671 pNew->x.pSelect = sqlite3SelectDup(db, p->x.pSelect, dupFlags);
001672 }else{
001673 pNew->x.pList = sqlite3ExprListDup(db, p->x.pList,
001674 p->op!=TK_ORDER ? dupFlags : 0);
001675 }
001676
001677 #ifndef SQLITE_OMIT_WINDOWFUNC
001678 if( ExprHasProperty(p, EP_WinFunc) ){
001679 pNew->y.pWin = sqlite3WindowDup(db, pNew, p->y.pWin);
001680 assert( ExprHasProperty(pNew, EP_WinFunc) );
001681 }
001682 #endif /* SQLITE_OMIT_WINDOWFUNC */
001683
001684 /* Fill in pNew->pLeft and pNew->pRight. */
001685 if( dupFlags ){
001686 if( p->op==TK_SELECT_COLUMN ){
001687 pNew->pLeft = p->pLeft;
001688 assert( p->pRight==0
001689 || p->pRight==p->pLeft
001690 || ExprHasProperty(p->pLeft, EP_Subquery) );
001691 }else{
001692 pNew->pLeft = p->pLeft ?
001693 exprDup(db, p->pLeft, EXPRDUP_REDUCE, &sEdupBuf) : 0;
001694 }
001695 pNew->pRight = p->pRight ?
001696 exprDup(db, p->pRight, EXPRDUP_REDUCE, &sEdupBuf) : 0;
001697 }else{
001698 if( p->op==TK_SELECT_COLUMN ){
001699 pNew->pLeft = p->pLeft;
001700 assert( p->pRight==0
001701 || p->pRight==p->pLeft
001702 || ExprHasProperty(p->pLeft, EP_Subquery) );
001703 }else{
001704 pNew->pLeft = sqlite3ExprDup(db, p->pLeft, 0);
001705 }
001706 pNew->pRight = sqlite3ExprDup(db, p->pRight, 0);
001707 }
001708 }
001709 }
001710 if( pEdupBuf ) memcpy(pEdupBuf, &sEdupBuf, sizeof(sEdupBuf));
001711 assert( sEdupBuf.zAlloc <= sEdupBuf.zEnd );
001712 return pNew;
001713 }
001714
001715 /*
001716 ** Create and return a deep copy of the object passed as the second
001717 ** argument. If an OOM condition is encountered, NULL is returned
001718 ** and the db->mallocFailed flag set.
001719 */
001720 #ifndef SQLITE_OMIT_CTE
001721 With *sqlite3WithDup(sqlite3 *db, With *p){
001722 With *pRet = 0;
001723 if( p ){
001724 sqlite3_int64 nByte = sizeof(*p) + sizeof(p->a[0]) * (p->nCte-1);
001725 pRet = sqlite3DbMallocZero(db, nByte);
001726 if( pRet ){
001727 int i;
001728 pRet->nCte = p->nCte;
001729 for(i=0; i<p->nCte; i++){
001730 pRet->a[i].pSelect = sqlite3SelectDup(db, p->a[i].pSelect, 0);
001731 pRet->a[i].pCols = sqlite3ExprListDup(db, p->a[i].pCols, 0);
001732 pRet->a[i].zName = sqlite3DbStrDup(db, p->a[i].zName);
001733 pRet->a[i].eM10d = p->a[i].eM10d;
001734 }
001735 }
001736 }
001737 return pRet;
001738 }
001739 #else
001740 # define sqlite3WithDup(x,y) 0
001741 #endif
001742
001743 #ifndef SQLITE_OMIT_WINDOWFUNC
001744 /*
001745 ** The gatherSelectWindows() procedure and its helper routine
001746 ** gatherSelectWindowsCallback() are used to scan all the expressions
001747 ** an a newly duplicated SELECT statement and gather all of the Window
001748 ** objects found there, assembling them onto the linked list at Select->pWin.
001749 */
001750 static int gatherSelectWindowsCallback(Walker *pWalker, Expr *pExpr){
001751 if( pExpr->op==TK_FUNCTION && ExprHasProperty(pExpr, EP_WinFunc) ){
001752 Select *pSelect = pWalker->u.pSelect;
001753 Window *pWin = pExpr->y.pWin;
001754 assert( pWin );
001755 assert( IsWindowFunc(pExpr) );
001756 assert( pWin->ppThis==0 );
001757 sqlite3WindowLink(pSelect, pWin);
001758 }
001759 return WRC_Continue;
001760 }
001761 static int gatherSelectWindowsSelectCallback(Walker *pWalker, Select *p){
001762 return p==pWalker->u.pSelect ? WRC_Continue : WRC_Prune;
001763 }
001764 static void gatherSelectWindows(Select *p){
001765 Walker w;
001766 w.xExprCallback = gatherSelectWindowsCallback;
001767 w.xSelectCallback = gatherSelectWindowsSelectCallback;
001768 w.xSelectCallback2 = 0;
001769 w.pParse = 0;
001770 w.u.pSelect = p;
001771 sqlite3WalkSelect(&w, p);
001772 }
001773 #endif
001774
001775
001776 /*
001777 ** The following group of routines make deep copies of expressions,
001778 ** expression lists, ID lists, and select statements. The copies can
001779 ** be deleted (by being passed to their respective ...Delete() routines)
001780 ** without effecting the originals.
001781 **
001782 ** The expression list, ID, and source lists return by sqlite3ExprListDup(),
001783 ** sqlite3IdListDup(), and sqlite3SrcListDup() can not be further expanded
001784 ** by subsequent calls to sqlite*ListAppend() routines.
001785 **
001786 ** Any tables that the SrcList might point to are not duplicated.
001787 **
001788 ** The flags parameter contains a combination of the EXPRDUP_XXX flags.
001789 ** If the EXPRDUP_REDUCE flag is set, then the structure returned is a
001790 ** truncated version of the usual Expr structure that will be stored as
001791 ** part of the in-memory representation of the database schema.
001792 */
001793 Expr *sqlite3ExprDup(sqlite3 *db, const Expr *p, int flags){
001794 assert( flags==0 || flags==EXPRDUP_REDUCE );
001795 return p ? exprDup(db, p, flags, 0) : 0;
001796 }
001797 ExprList *sqlite3ExprListDup(sqlite3 *db, const ExprList *p, int flags){
001798 ExprList *pNew;
001799 struct ExprList_item *pItem;
001800 const struct ExprList_item *pOldItem;
001801 int i;
001802 Expr *pPriorSelectColOld = 0;
001803 Expr *pPriorSelectColNew = 0;
001804 assert( db!=0 );
001805 if( p==0 ) return 0;
001806 pNew = sqlite3DbMallocRawNN(db, sqlite3DbMallocSize(db, p));
001807 if( pNew==0 ) return 0;
001808 pNew->nExpr = p->nExpr;
001809 pNew->nAlloc = p->nAlloc;
001810 pItem = pNew->a;
001811 pOldItem = p->a;
001812 for(i=0; i<p->nExpr; i++, pItem++, pOldItem++){
001813 Expr *pOldExpr = pOldItem->pExpr;
001814 Expr *pNewExpr;
001815 pItem->pExpr = sqlite3ExprDup(db, pOldExpr, flags);
001816 if( pOldExpr
001817 && pOldExpr->op==TK_SELECT_COLUMN
001818 && (pNewExpr = pItem->pExpr)!=0
001819 ){
001820 if( pNewExpr->pRight ){
001821 pPriorSelectColOld = pOldExpr->pRight;
001822 pPriorSelectColNew = pNewExpr->pRight;
001823 pNewExpr->pLeft = pNewExpr->pRight;
001824 }else{
001825 if( pOldExpr->pLeft!=pPriorSelectColOld ){
001826 pPriorSelectColOld = pOldExpr->pLeft;
001827 pPriorSelectColNew = sqlite3ExprDup(db, pPriorSelectColOld, flags);
001828 pNewExpr->pRight = pPriorSelectColNew;
001829 }
001830 pNewExpr->pLeft = pPriorSelectColNew;
001831 }
001832 }
001833 pItem->zEName = sqlite3DbStrDup(db, pOldItem->zEName);
001834 pItem->fg = pOldItem->fg;
001835 pItem->fg.done = 0;
001836 pItem->u = pOldItem->u;
001837 }
001838 return pNew;
001839 }
001840
001841 /*
001842 ** If cursors, triggers, views and subqueries are all omitted from
001843 ** the build, then none of the following routines, except for
001844 ** sqlite3SelectDup(), can be called. sqlite3SelectDup() is sometimes
001845 ** called with a NULL argument.
001846 */
001847 #if !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_TRIGGER) \
001848 || !defined(SQLITE_OMIT_SUBQUERY)
001849 SrcList *sqlite3SrcListDup(sqlite3 *db, const SrcList *p, int flags){
001850 SrcList *pNew;
001851 int i;
001852 int nByte;
001853 assert( db!=0 );
001854 if( p==0 ) return 0;
001855 nByte = sizeof(*p) + (p->nSrc>0 ? sizeof(p->a[0]) * (p->nSrc-1) : 0);
001856 pNew = sqlite3DbMallocRawNN(db, nByte );
001857 if( pNew==0 ) return 0;
001858 pNew->nSrc = pNew->nAlloc = p->nSrc;
001859 for(i=0; i<p->nSrc; i++){
001860 SrcItem *pNewItem = &pNew->a[i];
001861 const SrcItem *pOldItem = &p->a[i];
001862 Table *pTab;
001863 pNewItem->pSchema = pOldItem->pSchema;
001864 pNewItem->zDatabase = sqlite3DbStrDup(db, pOldItem->zDatabase);
001865 pNewItem->zName = sqlite3DbStrDup(db, pOldItem->zName);
001866 pNewItem->zAlias = sqlite3DbStrDup(db, pOldItem->zAlias);
001867 pNewItem->fg = pOldItem->fg;
001868 pNewItem->iCursor = pOldItem->iCursor;
001869 pNewItem->addrFillSub = pOldItem->addrFillSub;
001870 pNewItem->regReturn = pOldItem->regReturn;
001871 if( pNewItem->fg.isIndexedBy ){
001872 pNewItem->u1.zIndexedBy = sqlite3DbStrDup(db, pOldItem->u1.zIndexedBy);
001873 }
001874 pNewItem->u2 = pOldItem->u2;
001875 if( pNewItem->fg.isCte ){
001876 pNewItem->u2.pCteUse->nUse++;
001877 }
001878 if( pNewItem->fg.isTabFunc ){
001879 pNewItem->u1.pFuncArg =
001880 sqlite3ExprListDup(db, pOldItem->u1.pFuncArg, flags);
001881 }
001882 pTab = pNewItem->pTab = pOldItem->pTab;
001883 if( pTab ){
001884 pTab->nTabRef++;
001885 }
001886 pNewItem->pSelect = sqlite3SelectDup(db, pOldItem->pSelect, flags);
001887 if( pOldItem->fg.isUsing ){
001888 assert( pNewItem->fg.isUsing );
001889 pNewItem->u3.pUsing = sqlite3IdListDup(db, pOldItem->u3.pUsing);
001890 }else{
001891 pNewItem->u3.pOn = sqlite3ExprDup(db, pOldItem->u3.pOn, flags);
001892 }
001893 pNewItem->colUsed = pOldItem->colUsed;
001894 }
001895 return pNew;
001896 }
001897 IdList *sqlite3IdListDup(sqlite3 *db, const IdList *p){
001898 IdList *pNew;
001899 int i;
001900 assert( db!=0 );
001901 if( p==0 ) return 0;
001902 assert( p->eU4!=EU4_EXPR );
001903 pNew = sqlite3DbMallocRawNN(db, sizeof(*pNew)+(p->nId-1)*sizeof(p->a[0]) );
001904 if( pNew==0 ) return 0;
001905 pNew->nId = p->nId;
001906 pNew->eU4 = p->eU4;
001907 for(i=0; i<p->nId; i++){
001908 struct IdList_item *pNewItem = &pNew->a[i];
001909 const struct IdList_item *pOldItem = &p->a[i];
001910 pNewItem->zName = sqlite3DbStrDup(db, pOldItem->zName);
001911 pNewItem->u4 = pOldItem->u4;
001912 }
001913 return pNew;
001914 }
001915 Select *sqlite3SelectDup(sqlite3 *db, const Select *pDup, int flags){
001916 Select *pRet = 0;
001917 Select *pNext = 0;
001918 Select **pp = &pRet;
001919 const Select *p;
001920
001921 assert( db!=0 );
001922 for(p=pDup; p; p=p->pPrior){
001923 Select *pNew = sqlite3DbMallocRawNN(db, sizeof(*p) );
001924 if( pNew==0 ) break;
001925 pNew->pEList = sqlite3ExprListDup(db, p->pEList, flags);
001926 pNew->pSrc = sqlite3SrcListDup(db, p->pSrc, flags);
001927 pNew->pWhere = sqlite3ExprDup(db, p->pWhere, flags);
001928 pNew->pGroupBy = sqlite3ExprListDup(db, p->pGroupBy, flags);
001929 pNew->pHaving = sqlite3ExprDup(db, p->pHaving, flags);
001930 pNew->pOrderBy = sqlite3ExprListDup(db, p->pOrderBy, flags);
001931 pNew->op = p->op;
001932 pNew->pNext = pNext;
001933 pNew->pPrior = 0;
001934 pNew->pLimit = sqlite3ExprDup(db, p->pLimit, flags);
001935 pNew->iLimit = 0;
001936 pNew->iOffset = 0;
001937 pNew->selFlags = p->selFlags & ~SF_UsesEphemeral;
001938 pNew->addrOpenEphm[0] = -1;
001939 pNew->addrOpenEphm[1] = -1;
001940 pNew->nSelectRow = p->nSelectRow;
001941 pNew->pWith = sqlite3WithDup(db, p->pWith);
001942 #ifndef SQLITE_OMIT_WINDOWFUNC
001943 pNew->pWin = 0;
001944 pNew->pWinDefn = sqlite3WindowListDup(db, p->pWinDefn);
001945 if( p->pWin && db->mallocFailed==0 ) gatherSelectWindows(pNew);
001946 #endif
001947 pNew->selId = p->selId;
001948 if( db->mallocFailed ){
001949 /* Any prior OOM might have left the Select object incomplete.
001950 ** Delete the whole thing rather than allow an incomplete Select
001951 ** to be used by the code generator. */
001952 pNew->pNext = 0;
001953 sqlite3SelectDelete(db, pNew);
001954 break;
001955 }
001956 *pp = pNew;
001957 pp = &pNew->pPrior;
001958 pNext = pNew;
001959 }
001960
001961 return pRet;
001962 }
001963 #else
001964 Select *sqlite3SelectDup(sqlite3 *db, const Select *p, int flags){
001965 assert( p==0 );
001966 return 0;
001967 }
001968 #endif
001969
001970
001971 /*
001972 ** Add a new element to the end of an expression list. If pList is
001973 ** initially NULL, then create a new expression list.
001974 **
001975 ** The pList argument must be either NULL or a pointer to an ExprList
001976 ** obtained from a prior call to sqlite3ExprListAppend().
001977 **
001978 ** If a memory allocation error occurs, the entire list is freed and
001979 ** NULL is returned. If non-NULL is returned, then it is guaranteed
001980 ** that the new entry was successfully appended.
001981 */
001982 static const struct ExprList_item zeroItem = {0};
001983 SQLITE_NOINLINE ExprList *sqlite3ExprListAppendNew(
001984 sqlite3 *db, /* Database handle. Used for memory allocation */
001985 Expr *pExpr /* Expression to be appended. Might be NULL */
001986 ){
001987 struct ExprList_item *pItem;
001988 ExprList *pList;
001989
001990 pList = sqlite3DbMallocRawNN(db, sizeof(ExprList)+sizeof(pList->a[0])*4 );
001991 if( pList==0 ){
001992 sqlite3ExprDelete(db, pExpr);
001993 return 0;
001994 }
001995 pList->nAlloc = 4;
001996 pList->nExpr = 1;
001997 pItem = &pList->a[0];
001998 *pItem = zeroItem;
001999 pItem->pExpr = pExpr;
002000 return pList;
002001 }
002002 SQLITE_NOINLINE ExprList *sqlite3ExprListAppendGrow(
002003 sqlite3 *db, /* Database handle. Used for memory allocation */
002004 ExprList *pList, /* List to which to append. Might be NULL */
002005 Expr *pExpr /* Expression to be appended. Might be NULL */
002006 ){
002007 struct ExprList_item *pItem;
002008 ExprList *pNew;
002009 pList->nAlloc *= 2;
002010 pNew = sqlite3DbRealloc(db, pList,
002011 sizeof(*pList)+(pList->nAlloc-1)*sizeof(pList->a[0]));
002012 if( pNew==0 ){
002013 sqlite3ExprListDelete(db, pList);
002014 sqlite3ExprDelete(db, pExpr);
002015 return 0;
002016 }else{
002017 pList = pNew;
002018 }
002019 pItem = &pList->a[pList->nExpr++];
002020 *pItem = zeroItem;
002021 pItem->pExpr = pExpr;
002022 return pList;
002023 }
002024 ExprList *sqlite3ExprListAppend(
002025 Parse *pParse, /* Parsing context */
002026 ExprList *pList, /* List to which to append. Might be NULL */
002027 Expr *pExpr /* Expression to be appended. Might be NULL */
002028 ){
002029 struct ExprList_item *pItem;
002030 if( pList==0 ){
002031 return sqlite3ExprListAppendNew(pParse->db,pExpr);
002032 }
002033 if( pList->nAlloc<pList->nExpr+1 ){
002034 return sqlite3ExprListAppendGrow(pParse->db,pList,pExpr);
002035 }
002036 pItem = &pList->a[pList->nExpr++];
002037 *pItem = zeroItem;
002038 pItem->pExpr = pExpr;
002039 return pList;
002040 }
002041
002042 /*
002043 ** pColumns and pExpr form a vector assignment which is part of the SET
002044 ** clause of an UPDATE statement. Like this:
002045 **
002046 ** (a,b,c) = (expr1,expr2,expr3)
002047 ** Or: (a,b,c) = (SELECT x,y,z FROM ....)
002048 **
002049 ** For each term of the vector assignment, append new entries to the
002050 ** expression list pList. In the case of a subquery on the RHS, append
002051 ** TK_SELECT_COLUMN expressions.
002052 */
002053 ExprList *sqlite3ExprListAppendVector(
002054 Parse *pParse, /* Parsing context */
002055 ExprList *pList, /* List to which to append. Might be NULL */
002056 IdList *pColumns, /* List of names of LHS of the assignment */
002057 Expr *pExpr /* Vector expression to be appended. Might be NULL */
002058 ){
002059 sqlite3 *db = pParse->db;
002060 int n;
002061 int i;
002062 int iFirst = pList ? pList->nExpr : 0;
002063 /* pColumns can only be NULL due to an OOM but an OOM will cause an
002064 ** exit prior to this routine being invoked */
002065 if( NEVER(pColumns==0) ) goto vector_append_error;
002066 if( pExpr==0 ) goto vector_append_error;
002067
002068 /* If the RHS is a vector, then we can immediately check to see that
002069 ** the size of the RHS and LHS match. But if the RHS is a SELECT,
002070 ** wildcards ("*") in the result set of the SELECT must be expanded before
002071 ** we can do the size check, so defer the size check until code generation.
002072 */
002073 if( pExpr->op!=TK_SELECT && pColumns->nId!=(n=sqlite3ExprVectorSize(pExpr)) ){
002074 sqlite3ErrorMsg(pParse, "%d columns assigned %d values",
002075 pColumns->nId, n);
002076 goto vector_append_error;
002077 }
002078
002079 for(i=0; i<pColumns->nId; i++){
002080 Expr *pSubExpr = sqlite3ExprForVectorField(pParse, pExpr, i, pColumns->nId);
002081 assert( pSubExpr!=0 || db->mallocFailed );
002082 if( pSubExpr==0 ) continue;
002083 pList = sqlite3ExprListAppend(pParse, pList, pSubExpr);
002084 if( pList ){
002085 assert( pList->nExpr==iFirst+i+1 );
002086 pList->a[pList->nExpr-1].zEName = pColumns->a[i].zName;
002087 pColumns->a[i].zName = 0;
002088 }
002089 }
002090
002091 if( !db->mallocFailed && pExpr->op==TK_SELECT && ALWAYS(pList!=0) ){
002092 Expr *pFirst = pList->a[iFirst].pExpr;
002093 assert( pFirst!=0 );
002094 assert( pFirst->op==TK_SELECT_COLUMN );
002095
002096 /* Store the SELECT statement in pRight so it will be deleted when
002097 ** sqlite3ExprListDelete() is called */
002098 pFirst->pRight = pExpr;
002099 pExpr = 0;
002100
002101 /* Remember the size of the LHS in iTable so that we can check that
002102 ** the RHS and LHS sizes match during code generation. */
002103 pFirst->iTable = pColumns->nId;
002104 }
002105
002106 vector_append_error:
002107 sqlite3ExprUnmapAndDelete(pParse, pExpr);
002108 sqlite3IdListDelete(db, pColumns);
002109 return pList;
002110 }
002111
002112 /*
002113 ** Set the sort order for the last element on the given ExprList.
002114 */
002115 void sqlite3ExprListSetSortOrder(ExprList *p, int iSortOrder, int eNulls){
002116 struct ExprList_item *pItem;
002117 if( p==0 ) return;
002118 assert( p->nExpr>0 );
002119
002120 assert( SQLITE_SO_UNDEFINED<0 && SQLITE_SO_ASC==0 && SQLITE_SO_DESC>0 );
002121 assert( iSortOrder==SQLITE_SO_UNDEFINED
002122 || iSortOrder==SQLITE_SO_ASC
002123 || iSortOrder==SQLITE_SO_DESC
002124 );
002125 assert( eNulls==SQLITE_SO_UNDEFINED
002126 || eNulls==SQLITE_SO_ASC
002127 || eNulls==SQLITE_SO_DESC
002128 );
002129
002130 pItem = &p->a[p->nExpr-1];
002131 assert( pItem->fg.bNulls==0 );
002132 if( iSortOrder==SQLITE_SO_UNDEFINED ){
002133 iSortOrder = SQLITE_SO_ASC;
002134 }
002135 pItem->fg.sortFlags = (u8)iSortOrder;
002136
002137 if( eNulls!=SQLITE_SO_UNDEFINED ){
002138 pItem->fg.bNulls = 1;
002139 if( iSortOrder!=eNulls ){
002140 pItem->fg.sortFlags |= KEYINFO_ORDER_BIGNULL;
002141 }
002142 }
002143 }
002144
002145 /*
002146 ** Set the ExprList.a[].zEName element of the most recently added item
002147 ** on the expression list.
002148 **
002149 ** pList might be NULL following an OOM error. But pName should never be
002150 ** NULL. If a memory allocation fails, the pParse->db->mallocFailed flag
002151 ** is set.
002152 */
002153 void sqlite3ExprListSetName(
002154 Parse *pParse, /* Parsing context */
002155 ExprList *pList, /* List to which to add the span. */
002156 const Token *pName, /* Name to be added */
002157 int dequote /* True to cause the name to be dequoted */
002158 ){
002159 assert( pList!=0 || pParse->db->mallocFailed!=0 );
002160 assert( pParse->eParseMode!=PARSE_MODE_UNMAP || dequote==0 );
002161 if( pList ){
002162 struct ExprList_item *pItem;
002163 assert( pList->nExpr>0 );
002164 pItem = &pList->a[pList->nExpr-1];
002165 assert( pItem->zEName==0 );
002166 assert( pItem->fg.eEName==ENAME_NAME );
002167 pItem->zEName = sqlite3DbStrNDup(pParse->db, pName->z, pName->n);
002168 if( dequote ){
002169 /* If dequote==0, then pName->z does not point to part of a DDL
002170 ** statement handled by the parser. And so no token need be added
002171 ** to the token-map. */
002172 sqlite3Dequote(pItem->zEName);
002173 if( IN_RENAME_OBJECT ){
002174 sqlite3RenameTokenMap(pParse, (const void*)pItem->zEName, pName);
002175 }
002176 }
002177 }
002178 }
002179
002180 /*
002181 ** Set the ExprList.a[].zSpan element of the most recently added item
002182 ** on the expression list.
002183 **
002184 ** pList might be NULL following an OOM error. But pSpan should never be
002185 ** NULL. If a memory allocation fails, the pParse->db->mallocFailed flag
002186 ** is set.
002187 */
002188 void sqlite3ExprListSetSpan(
002189 Parse *pParse, /* Parsing context */
002190 ExprList *pList, /* List to which to add the span. */
002191 const char *zStart, /* Start of the span */
002192 const char *zEnd /* End of the span */
002193 ){
002194 sqlite3 *db = pParse->db;
002195 assert( pList!=0 || db->mallocFailed!=0 );
002196 if( pList ){
002197 struct ExprList_item *pItem = &pList->a[pList->nExpr-1];
002198 assert( pList->nExpr>0 );
002199 if( pItem->zEName==0 ){
002200 pItem->zEName = sqlite3DbSpanDup(db, zStart, zEnd);
002201 pItem->fg.eEName = ENAME_SPAN;
002202 }
002203 }
002204 }
002205
002206 /*
002207 ** If the expression list pEList contains more than iLimit elements,
002208 ** leave an error message in pParse.
002209 */
002210 void sqlite3ExprListCheckLength(
002211 Parse *pParse,
002212 ExprList *pEList,
002213 const char *zObject
002214 ){
002215 int mx = pParse->db->aLimit[SQLITE_LIMIT_COLUMN];
002216 testcase( pEList && pEList->nExpr==mx );
002217 testcase( pEList && pEList->nExpr==mx+1 );
002218 if( pEList && pEList->nExpr>mx ){
002219 sqlite3ErrorMsg(pParse, "too many columns in %s", zObject);
002220 }
002221 }
002222
002223 /*
002224 ** Delete an entire expression list.
002225 */
002226 static SQLITE_NOINLINE void exprListDeleteNN(sqlite3 *db, ExprList *pList){
002227 int i = pList->nExpr;
002228 struct ExprList_item *pItem = pList->a;
002229 assert( pList->nExpr>0 );
002230 assert( db!=0 );
002231 do{
002232 sqlite3ExprDelete(db, pItem->pExpr);
002233 if( pItem->zEName ) sqlite3DbNNFreeNN(db, pItem->zEName);
002234 pItem++;
002235 }while( --i>0 );
002236 sqlite3DbNNFreeNN(db, pList);
002237 }
002238 void sqlite3ExprListDelete(sqlite3 *db, ExprList *pList){
002239 if( pList ) exprListDeleteNN(db, pList);
002240 }
002241 void sqlite3ExprListDeleteGeneric(sqlite3 *db, void *pList){
002242 if( ALWAYS(pList) ) exprListDeleteNN(db, (ExprList*)pList);
002243 }
002244
002245 /*
002246 ** Return the bitwise-OR of all Expr.flags fields in the given
002247 ** ExprList.
002248 */
002249 u32 sqlite3ExprListFlags(const ExprList *pList){
002250 int i;
002251 u32 m = 0;
002252 assert( pList!=0 );
002253 for(i=0; i<pList->nExpr; i++){
002254 Expr *pExpr = pList->a[i].pExpr;
002255 assert( pExpr!=0 );
002256 m |= pExpr->flags;
002257 }
002258 return m;
002259 }
002260
002261 /*
002262 ** This is a SELECT-node callback for the expression walker that
002263 ** always "fails". By "fail" in this case, we mean set
002264 ** pWalker->eCode to zero and abort.
002265 **
002266 ** This callback is used by multiple expression walkers.
002267 */
002268 int sqlite3SelectWalkFail(Walker *pWalker, Select *NotUsed){
002269 UNUSED_PARAMETER(NotUsed);
002270 pWalker->eCode = 0;
002271 return WRC_Abort;
002272 }
002273
002274 /*
002275 ** Check the input string to see if it is "true" or "false" (in any case).
002276 **
002277 ** If the string is.... Return
002278 ** "true" EP_IsTrue
002279 ** "false" EP_IsFalse
002280 ** anything else 0
002281 */
002282 u32 sqlite3IsTrueOrFalse(const char *zIn){
002283 if( sqlite3StrICmp(zIn, "true")==0 ) return EP_IsTrue;
002284 if( sqlite3StrICmp(zIn, "false")==0 ) return EP_IsFalse;
002285 return 0;
002286 }
002287
002288
002289 /*
002290 ** If the input expression is an ID with the name "true" or "false"
002291 ** then convert it into an TK_TRUEFALSE term. Return non-zero if
002292 ** the conversion happened, and zero if the expression is unaltered.
002293 */
002294 int sqlite3ExprIdToTrueFalse(Expr *pExpr){
002295 u32 v;
002296 assert( pExpr->op==TK_ID || pExpr->op==TK_STRING );
002297 if( !ExprHasProperty(pExpr, EP_Quoted|EP_IntValue)
002298 && (v = sqlite3IsTrueOrFalse(pExpr->u.zToken))!=0
002299 ){
002300 pExpr->op = TK_TRUEFALSE;
002301 ExprSetProperty(pExpr, v);
002302 return 1;
002303 }
002304 return 0;
002305 }
002306
002307 /*
002308 ** The argument must be a TK_TRUEFALSE Expr node. Return 1 if it is TRUE
002309 ** and 0 if it is FALSE.
002310 */
002311 int sqlite3ExprTruthValue(const Expr *pExpr){
002312 pExpr = sqlite3ExprSkipCollateAndLikely((Expr*)pExpr);
002313 assert( pExpr->op==TK_TRUEFALSE );
002314 assert( !ExprHasProperty(pExpr, EP_IntValue) );
002315 assert( sqlite3StrICmp(pExpr->u.zToken,"true")==0
002316 || sqlite3StrICmp(pExpr->u.zToken,"false")==0 );
002317 return pExpr->u.zToken[4]==0;
002318 }
002319
002320 /*
002321 ** If pExpr is an AND or OR expression, try to simplify it by eliminating
002322 ** terms that are always true or false. Return the simplified expression.
002323 ** Or return the original expression if no simplification is possible.
002324 **
002325 ** Examples:
002326 **
002327 ** (x<10) AND true => (x<10)
002328 ** (x<10) AND false => false
002329 ** (x<10) AND (y=22 OR false) => (x<10) AND (y=22)
002330 ** (x<10) AND (y=22 OR true) => (x<10)
002331 ** (y=22) OR true => true
002332 */
002333 Expr *sqlite3ExprSimplifiedAndOr(Expr *pExpr){
002334 assert( pExpr!=0 );
002335 if( pExpr->op==TK_AND || pExpr->op==TK_OR ){
002336 Expr *pRight = sqlite3ExprSimplifiedAndOr(pExpr->pRight);
002337 Expr *pLeft = sqlite3ExprSimplifiedAndOr(pExpr->pLeft);
002338 if( ExprAlwaysTrue(pLeft) || ExprAlwaysFalse(pRight) ){
002339 pExpr = pExpr->op==TK_AND ? pRight : pLeft;
002340 }else if( ExprAlwaysTrue(pRight) || ExprAlwaysFalse(pLeft) ){
002341 pExpr = pExpr->op==TK_AND ? pLeft : pRight;
002342 }
002343 }
002344 return pExpr;
002345 }
002346
002347
002348 /*
002349 ** These routines are Walker callbacks used to check expressions to
002350 ** see if they are "constant" for some definition of constant. The
002351 ** Walker.eCode value determines the type of "constant" we are looking
002352 ** for.
002353 **
002354 ** These callback routines are used to implement the following:
002355 **
002356 ** sqlite3ExprIsConstant() pWalker->eCode==1
002357 ** sqlite3ExprIsConstantNotJoin() pWalker->eCode==2
002358 ** sqlite3ExprIsTableConstant() pWalker->eCode==3
002359 ** sqlite3ExprIsConstantOrFunction() pWalker->eCode==4 or 5
002360 **
002361 ** In all cases, the callbacks set Walker.eCode=0 and abort if the expression
002362 ** is found to not be a constant.
002363 **
002364 ** The sqlite3ExprIsConstantOrFunction() is used for evaluating DEFAULT
002365 ** expressions in a CREATE TABLE statement. The Walker.eCode value is 5
002366 ** when parsing an existing schema out of the sqlite_schema table and 4
002367 ** when processing a new CREATE TABLE statement. A bound parameter raises
002368 ** an error for new statements, but is silently converted
002369 ** to NULL for existing schemas. This allows sqlite_schema tables that
002370 ** contain a bound parameter because they were generated by older versions
002371 ** of SQLite to be parsed by newer versions of SQLite without raising a
002372 ** malformed schema error.
002373 */
002374 static int exprNodeIsConstant(Walker *pWalker, Expr *pExpr){
002375
002376 /* If pWalker->eCode is 2 then any term of the expression that comes from
002377 ** the ON or USING clauses of an outer join disqualifies the expression
002378 ** from being considered constant. */
002379 if( pWalker->eCode==2 && ExprHasProperty(pExpr, EP_OuterON) ){
002380 pWalker->eCode = 0;
002381 return WRC_Abort;
002382 }
002383
002384 switch( pExpr->op ){
002385 /* Consider functions to be constant if all their arguments are constant
002386 ** and either pWalker->eCode==4 or 5 or the function has the
002387 ** SQLITE_FUNC_CONST flag. */
002388 case TK_FUNCTION:
002389 if( (pWalker->eCode>=4 || ExprHasProperty(pExpr,EP_ConstFunc))
002390 && !ExprHasProperty(pExpr, EP_WinFunc)
002391 ){
002392 if( pWalker->eCode==5 ) ExprSetProperty(pExpr, EP_FromDDL);
002393 return WRC_Continue;
002394 }else{
002395 pWalker->eCode = 0;
002396 return WRC_Abort;
002397 }
002398 case TK_ID:
002399 /* Convert "true" or "false" in a DEFAULT clause into the
002400 ** appropriate TK_TRUEFALSE operator */
002401 if( sqlite3ExprIdToTrueFalse(pExpr) ){
002402 return WRC_Prune;
002403 }
002404 /* no break */ deliberate_fall_through
002405 case TK_COLUMN:
002406 case TK_AGG_FUNCTION:
002407 case TK_AGG_COLUMN:
002408 testcase( pExpr->op==TK_ID );
002409 testcase( pExpr->op==TK_COLUMN );
002410 testcase( pExpr->op==TK_AGG_FUNCTION );
002411 testcase( pExpr->op==TK_AGG_COLUMN );
002412 if( ExprHasProperty(pExpr, EP_FixedCol) && pWalker->eCode!=2 ){
002413 return WRC_Continue;
002414 }
002415 if( pWalker->eCode==3 && pExpr->iTable==pWalker->u.iCur ){
002416 return WRC_Continue;
002417 }
002418 /* no break */ deliberate_fall_through
002419 case TK_IF_NULL_ROW:
002420 case TK_REGISTER:
002421 case TK_DOT:
002422 testcase( pExpr->op==TK_REGISTER );
002423 testcase( pExpr->op==TK_IF_NULL_ROW );
002424 testcase( pExpr->op==TK_DOT );
002425 pWalker->eCode = 0;
002426 return WRC_Abort;
002427 case TK_VARIABLE:
002428 if( pWalker->eCode==5 ){
002429 /* Silently convert bound parameters that appear inside of CREATE
002430 ** statements into a NULL when parsing the CREATE statement text out
002431 ** of the sqlite_schema table */
002432 pExpr->op = TK_NULL;
002433 }else if( pWalker->eCode==4 ){
002434 /* A bound parameter in a CREATE statement that originates from
002435 ** sqlite3_prepare() causes an error */
002436 pWalker->eCode = 0;
002437 return WRC_Abort;
002438 }
002439 /* no break */ deliberate_fall_through
002440 default:
002441 testcase( pExpr->op==TK_SELECT ); /* sqlite3SelectWalkFail() disallows */
002442 testcase( pExpr->op==TK_EXISTS ); /* sqlite3SelectWalkFail() disallows */
002443 return WRC_Continue;
002444 }
002445 }
002446 static int exprIsConst(Expr *p, int initFlag, int iCur){
002447 Walker w;
002448 w.eCode = initFlag;
002449 w.xExprCallback = exprNodeIsConstant;
002450 w.xSelectCallback = sqlite3SelectWalkFail;
002451 #ifdef SQLITE_DEBUG
002452 w.xSelectCallback2 = sqlite3SelectWalkAssert2;
002453 #endif
002454 w.u.iCur = iCur;
002455 sqlite3WalkExpr(&w, p);
002456 return w.eCode;
002457 }
002458
002459 /*
002460 ** Walk an expression tree. Return non-zero if the expression is constant
002461 ** and 0 if it involves variables or function calls.
002462 **
002463 ** For the purposes of this function, a double-quoted string (ex: "abc")
002464 ** is considered a variable but a single-quoted string (ex: 'abc') is
002465 ** a constant.
002466 */
002467 int sqlite3ExprIsConstant(Expr *p){
002468 return exprIsConst(p, 1, 0);
002469 }
002470
002471 /*
002472 ** Walk an expression tree. Return non-zero if
002473 **
002474 ** (1) the expression is constant, and
002475 ** (2) the expression does originate in the ON or USING clause
002476 ** of a LEFT JOIN, and
002477 ** (3) the expression does not contain any EP_FixedCol TK_COLUMN
002478 ** operands created by the constant propagation optimization.
002479 **
002480 ** When this routine returns true, it indicates that the expression
002481 ** can be added to the pParse->pConstExpr list and evaluated once when
002482 ** the prepared statement starts up. See sqlite3ExprCodeRunJustOnce().
002483 */
002484 int sqlite3ExprIsConstantNotJoin(Expr *p){
002485 return exprIsConst(p, 2, 0);
002486 }
002487
002488 /*
002489 ** Walk an expression tree. Return non-zero if the expression is constant
002490 ** for any single row of the table with cursor iCur. In other words, the
002491 ** expression must not refer to any non-deterministic function nor any
002492 ** table other than iCur.
002493 */
002494 int sqlite3ExprIsTableConstant(Expr *p, int iCur){
002495 return exprIsConst(p, 3, iCur);
002496 }
002497
002498 /*
002499 ** Check pExpr to see if it is an constraint on the single data source
002500 ** pSrc = &pSrcList->a[iSrc]. In other words, check to see if pExpr
002501 ** constrains pSrc but does not depend on any other tables or data
002502 ** sources anywhere else in the query. Return true (non-zero) if pExpr
002503 ** is a constraint on pSrc only.
002504 **
002505 ** This is an optimization. False negatives will perhaps cause slower
002506 ** queries, but false positives will yield incorrect answers. So when in
002507 ** doubt, return 0.
002508 **
002509 ** To be an single-source constraint, the following must be true:
002510 **
002511 ** (1) pExpr cannot refer to any table other than pSrc->iCursor.
002512 **
002513 ** (2) pExpr cannot use subqueries or non-deterministic functions.
002514 **
002515 ** (3) pSrc cannot be part of the left operand for a RIGHT JOIN.
002516 ** (Is there some way to relax this constraint?)
002517 **
002518 ** (4) If pSrc is the right operand of a LEFT JOIN, then...
002519 ** (4a) pExpr must come from an ON clause..
002520 ** (4b) and specifically the ON clause associated with the LEFT JOIN.
002521 **
002522 ** (5) If pSrc is not the right operand of a LEFT JOIN or the left
002523 ** operand of a RIGHT JOIN, then pExpr must be from the WHERE
002524 ** clause, not an ON clause.
002525 **
002526 ** (6) Either:
002527 **
002528 ** (6a) pExpr does not originate in an ON or USING clause, or
002529 **
002530 ** (6b) The ON or USING clause from which pExpr is derived is
002531 ** not to the left of a RIGHT JOIN (or FULL JOIN).
002532 **
002533 ** Without this restriction, accepting pExpr as a single-table
002534 ** constraint might move the the ON/USING filter expression
002535 ** from the left side of a RIGHT JOIN over to the right side,
002536 ** which leads to incorrect answers. See also restriction (9)
002537 ** on push-down.
002538 */
002539 int sqlite3ExprIsSingleTableConstraint(
002540 Expr *pExpr, /* The constraint */
002541 const SrcList *pSrcList, /* Complete FROM clause */
002542 int iSrc /* Which element of pSrcList to use */
002543 ){
002544 const SrcItem *pSrc = &pSrcList->a[iSrc];
002545 if( pSrc->fg.jointype & JT_LTORJ ){
002546 return 0; /* rule (3) */
002547 }
002548 if( pSrc->fg.jointype & JT_LEFT ){
002549 if( !ExprHasProperty(pExpr, EP_OuterON) ) return 0; /* rule (4a) */
002550 if( pExpr->w.iJoin!=pSrc->iCursor ) return 0; /* rule (4b) */
002551 }else{
002552 if( ExprHasProperty(pExpr, EP_OuterON) ) return 0; /* rule (5) */
002553 }
002554 if( ExprHasProperty(pExpr, EP_OuterON|EP_InnerON) /* (6a) */
002555 && (pSrcList->a[0].fg.jointype & JT_LTORJ)!=0 /* Fast pre-test of (6b) */
002556 ){
002557 int jj;
002558 for(jj=0; jj<iSrc; jj++){
002559 if( pExpr->w.iJoin==pSrcList->a[jj].iCursor ){
002560 if( (pSrcList->a[jj].fg.jointype & JT_LTORJ)!=0 ){
002561 return 0; /* restriction (6) */
002562 }
002563 break;
002564 }
002565 }
002566 }
002567 return sqlite3ExprIsTableConstant(pExpr, pSrc->iCursor); /* rules (1), (2) */
002568 }
002569
002570
002571 /*
002572 ** sqlite3WalkExpr() callback used by sqlite3ExprIsConstantOrGroupBy().
002573 */
002574 static int exprNodeIsConstantOrGroupBy(Walker *pWalker, Expr *pExpr){
002575 ExprList *pGroupBy = pWalker->u.pGroupBy;
002576 int i;
002577
002578 /* Check if pExpr is identical to any GROUP BY term. If so, consider
002579 ** it constant. */
002580 for(i=0; i<pGroupBy->nExpr; i++){
002581 Expr *p = pGroupBy->a[i].pExpr;
002582 if( sqlite3ExprCompare(0, pExpr, p, -1)<2 ){
002583 CollSeq *pColl = sqlite3ExprNNCollSeq(pWalker->pParse, p);
002584 if( sqlite3IsBinary(pColl) ){
002585 return WRC_Prune;
002586 }
002587 }
002588 }
002589
002590 /* Check if pExpr is a sub-select. If so, consider it variable. */
002591 if( ExprUseXSelect(pExpr) ){
002592 pWalker->eCode = 0;
002593 return WRC_Abort;
002594 }
002595
002596 return exprNodeIsConstant(pWalker, pExpr);
002597 }
002598
002599 /*
002600 ** Walk the expression tree passed as the first argument. Return non-zero
002601 ** if the expression consists entirely of constants or copies of terms
002602 ** in pGroupBy that sort with the BINARY collation sequence.
002603 **
002604 ** This routine is used to determine if a term of the HAVING clause can
002605 ** be promoted into the WHERE clause. In order for such a promotion to work,
002606 ** the value of the HAVING clause term must be the same for all members of
002607 ** a "group". The requirement that the GROUP BY term must be BINARY
002608 ** assumes that no other collating sequence will have a finer-grained
002609 ** grouping than binary. In other words (A=B COLLATE binary) implies
002610 ** A=B in every other collating sequence. The requirement that the
002611 ** GROUP BY be BINARY is stricter than necessary. It would also work
002612 ** to promote HAVING clauses that use the same alternative collating
002613 ** sequence as the GROUP BY term, but that is much harder to check,
002614 ** alternative collating sequences are uncommon, and this is only an
002615 ** optimization, so we take the easy way out and simply require the
002616 ** GROUP BY to use the BINARY collating sequence.
002617 */
002618 int sqlite3ExprIsConstantOrGroupBy(Parse *pParse, Expr *p, ExprList *pGroupBy){
002619 Walker w;
002620 w.eCode = 1;
002621 w.xExprCallback = exprNodeIsConstantOrGroupBy;
002622 w.xSelectCallback = 0;
002623 w.u.pGroupBy = pGroupBy;
002624 w.pParse = pParse;
002625 sqlite3WalkExpr(&w, p);
002626 return w.eCode;
002627 }
002628
002629 /*
002630 ** Walk an expression tree for the DEFAULT field of a column definition
002631 ** in a CREATE TABLE statement. Return non-zero if the expression is
002632 ** acceptable for use as a DEFAULT. That is to say, return non-zero if
002633 ** the expression is constant or a function call with constant arguments.
002634 ** Return and 0 if there are any variables.
002635 **
002636 ** isInit is true when parsing from sqlite_schema. isInit is false when
002637 ** processing a new CREATE TABLE statement. When isInit is true, parameters
002638 ** (such as ? or $abc) in the expression are converted into NULL. When
002639 ** isInit is false, parameters raise an error. Parameters should not be
002640 ** allowed in a CREATE TABLE statement, but some legacy versions of SQLite
002641 ** allowed it, so we need to support it when reading sqlite_schema for
002642 ** backwards compatibility.
002643 **
002644 ** If isInit is true, set EP_FromDDL on every TK_FUNCTION node.
002645 **
002646 ** For the purposes of this function, a double-quoted string (ex: "abc")
002647 ** is considered a variable but a single-quoted string (ex: 'abc') is
002648 ** a constant.
002649 */
002650 int sqlite3ExprIsConstantOrFunction(Expr *p, u8 isInit){
002651 assert( isInit==0 || isInit==1 );
002652 return exprIsConst(p, 4+isInit, 0);
002653 }
002654
002655 #ifdef SQLITE_ENABLE_CURSOR_HINTS
002656 /*
002657 ** Walk an expression tree. Return 1 if the expression contains a
002658 ** subquery of some kind. Return 0 if there are no subqueries.
002659 */
002660 int sqlite3ExprContainsSubquery(Expr *p){
002661 Walker w;
002662 w.eCode = 1;
002663 w.xExprCallback = sqlite3ExprWalkNoop;
002664 w.xSelectCallback = sqlite3SelectWalkFail;
002665 #ifdef SQLITE_DEBUG
002666 w.xSelectCallback2 = sqlite3SelectWalkAssert2;
002667 #endif
002668 sqlite3WalkExpr(&w, p);
002669 return w.eCode==0;
002670 }
002671 #endif
002672
002673 /*
002674 ** If the expression p codes a constant integer that is small enough
002675 ** to fit in a 32-bit integer, return 1 and put the value of the integer
002676 ** in *pValue. If the expression is not an integer or if it is too big
002677 ** to fit in a signed 32-bit integer, return 0 and leave *pValue unchanged.
002678 */
002679 int sqlite3ExprIsInteger(const Expr *p, int *pValue){
002680 int rc = 0;
002681 if( NEVER(p==0) ) return 0; /* Used to only happen following on OOM */
002682
002683 /* If an expression is an integer literal that fits in a signed 32-bit
002684 ** integer, then the EP_IntValue flag will have already been set */
002685 assert( p->op!=TK_INTEGER || (p->flags & EP_IntValue)!=0
002686 || sqlite3GetInt32(p->u.zToken, &rc)==0 );
002687
002688 if( p->flags & EP_IntValue ){
002689 *pValue = p->u.iValue;
002690 return 1;
002691 }
002692 switch( p->op ){
002693 case TK_UPLUS: {
002694 rc = sqlite3ExprIsInteger(p->pLeft, pValue);
002695 break;
002696 }
002697 case TK_UMINUS: {
002698 int v = 0;
002699 if( sqlite3ExprIsInteger(p->pLeft, &v) ){
002700 assert( ((unsigned int)v)!=0x80000000 );
002701 *pValue = -v;
002702 rc = 1;
002703 }
002704 break;
002705 }
002706 default: break;
002707 }
002708 return rc;
002709 }
002710
002711 /*
002712 ** Return FALSE if there is no chance that the expression can be NULL.
002713 **
002714 ** If the expression might be NULL or if the expression is too complex
002715 ** to tell return TRUE.
002716 **
002717 ** This routine is used as an optimization, to skip OP_IsNull opcodes
002718 ** when we know that a value cannot be NULL. Hence, a false positive
002719 ** (returning TRUE when in fact the expression can never be NULL) might
002720 ** be a small performance hit but is otherwise harmless. On the other
002721 ** hand, a false negative (returning FALSE when the result could be NULL)
002722 ** will likely result in an incorrect answer. So when in doubt, return
002723 ** TRUE.
002724 */
002725 int sqlite3ExprCanBeNull(const Expr *p){
002726 u8 op;
002727 assert( p!=0 );
002728 while( p->op==TK_UPLUS || p->op==TK_UMINUS ){
002729 p = p->pLeft;
002730 assert( p!=0 );
002731 }
002732 op = p->op;
002733 if( op==TK_REGISTER ) op = p->op2;
002734 switch( op ){
002735 case TK_INTEGER:
002736 case TK_STRING:
002737 case TK_FLOAT:
002738 case TK_BLOB:
002739 return 0;
002740 case TK_COLUMN:
002741 assert( ExprUseYTab(p) );
002742 return ExprHasProperty(p, EP_CanBeNull) ||
002743 NEVER(p->y.pTab==0) || /* Reference to column of index on expr */
002744 (p->iColumn>=0
002745 && p->y.pTab->aCol!=0 /* Possible due to prior error */
002746 && ALWAYS(p->iColumn<p->y.pTab->nCol)
002747 && p->y.pTab->aCol[p->iColumn].notNull==0);
002748 default:
002749 return 1;
002750 }
002751 }
002752
002753 /*
002754 ** Return TRUE if the given expression is a constant which would be
002755 ** unchanged by OP_Affinity with the affinity given in the second
002756 ** argument.
002757 **
002758 ** This routine is used to determine if the OP_Affinity operation
002759 ** can be omitted. When in doubt return FALSE. A false negative
002760 ** is harmless. A false positive, however, can result in the wrong
002761 ** answer.
002762 */
002763 int sqlite3ExprNeedsNoAffinityChange(const Expr *p, char aff){
002764 u8 op;
002765 int unaryMinus = 0;
002766 if( aff==SQLITE_AFF_BLOB ) return 1;
002767 while( p->op==TK_UPLUS || p->op==TK_UMINUS ){
002768 if( p->op==TK_UMINUS ) unaryMinus = 1;
002769 p = p->pLeft;
002770 }
002771 op = p->op;
002772 if( op==TK_REGISTER ) op = p->op2;
002773 switch( op ){
002774 case TK_INTEGER: {
002775 return aff>=SQLITE_AFF_NUMERIC;
002776 }
002777 case TK_FLOAT: {
002778 return aff>=SQLITE_AFF_NUMERIC;
002779 }
002780 case TK_STRING: {
002781 return !unaryMinus && aff==SQLITE_AFF_TEXT;
002782 }
002783 case TK_BLOB: {
002784 return !unaryMinus;
002785 }
002786 case TK_COLUMN: {
002787 assert( p->iTable>=0 ); /* p cannot be part of a CHECK constraint */
002788 return aff>=SQLITE_AFF_NUMERIC && p->iColumn<0;
002789 }
002790 default: {
002791 return 0;
002792 }
002793 }
002794 }
002795
002796 /*
002797 ** Return TRUE if the given string is a row-id column name.
002798 */
002799 int sqlite3IsRowid(const char *z){
002800 if( sqlite3StrICmp(z, "_ROWID_")==0 ) return 1;
002801 if( sqlite3StrICmp(z, "ROWID")==0 ) return 1;
002802 if( sqlite3StrICmp(z, "OID")==0 ) return 1;
002803 return 0;
002804 }
002805
002806 /*
002807 ** Return a pointer to a buffer containing a usable rowid alias for table
002808 ** pTab. An alias is usable if there is not an explicit user-defined column
002809 ** of the same name.
002810 */
002811 const char *sqlite3RowidAlias(Table *pTab){
002812 const char *azOpt[] = {"_ROWID_", "ROWID", "OID"};
002813 int ii;
002814 assert( VisibleRowid(pTab) );
002815 for(ii=0; ii<ArraySize(azOpt); ii++){
002816 int iCol;
002817 for(iCol=0; iCol<pTab->nCol; iCol++){
002818 if( sqlite3_stricmp(azOpt[ii], pTab->aCol[iCol].zCnName)==0 ) break;
002819 }
002820 if( iCol==pTab->nCol ){
002821 return azOpt[ii];
002822 }
002823 }
002824 return 0;
002825 }
002826
002827 /*
002828 ** pX is the RHS of an IN operator. If pX is a SELECT statement
002829 ** that can be simplified to a direct table access, then return
002830 ** a pointer to the SELECT statement. If pX is not a SELECT statement,
002831 ** or if the SELECT statement needs to be materialized into a transient
002832 ** table, then return NULL.
002833 */
002834 #ifndef SQLITE_OMIT_SUBQUERY
002835 static Select *isCandidateForInOpt(const Expr *pX){
002836 Select *p;
002837 SrcList *pSrc;
002838 ExprList *pEList;
002839 Table *pTab;
002840 int i;
002841 if( !ExprUseXSelect(pX) ) return 0; /* Not a subquery */
002842 if( ExprHasProperty(pX, EP_VarSelect) ) return 0; /* Correlated subq */
002843 p = pX->x.pSelect;
002844 if( p->pPrior ) return 0; /* Not a compound SELECT */
002845 if( p->selFlags & (SF_Distinct|SF_Aggregate) ){
002846 testcase( (p->selFlags & (SF_Distinct|SF_Aggregate))==SF_Distinct );
002847 testcase( (p->selFlags & (SF_Distinct|SF_Aggregate))==SF_Aggregate );
002848 return 0; /* No DISTINCT keyword and no aggregate functions */
002849 }
002850 assert( p->pGroupBy==0 ); /* Has no GROUP BY clause */
002851 if( p->pLimit ) return 0; /* Has no LIMIT clause */
002852 if( p->pWhere ) return 0; /* Has no WHERE clause */
002853 pSrc = p->pSrc;
002854 assert( pSrc!=0 );
002855 if( pSrc->nSrc!=1 ) return 0; /* Single term in FROM clause */
002856 if( pSrc->a[0].pSelect ) return 0; /* FROM is not a subquery or view */
002857 pTab = pSrc->a[0].pTab;
002858 assert( pTab!=0 );
002859 assert( !IsView(pTab) ); /* FROM clause is not a view */
002860 if( IsVirtual(pTab) ) return 0; /* FROM clause not a virtual table */
002861 pEList = p->pEList;
002862 assert( pEList!=0 );
002863 /* All SELECT results must be columns. */
002864 for(i=0; i<pEList->nExpr; i++){
002865 Expr *pRes = pEList->a[i].pExpr;
002866 if( pRes->op!=TK_COLUMN ) return 0;
002867 assert( pRes->iTable==pSrc->a[0].iCursor ); /* Not a correlated subquery */
002868 }
002869 return p;
002870 }
002871 #endif /* SQLITE_OMIT_SUBQUERY */
002872
002873 #ifndef SQLITE_OMIT_SUBQUERY
002874 /*
002875 ** Generate code that checks the left-most column of index table iCur to see if
002876 ** it contains any NULL entries. Cause the register at regHasNull to be set
002877 ** to a non-NULL value if iCur contains no NULLs. Cause register regHasNull
002878 ** to be set to NULL if iCur contains one or more NULL values.
002879 */
002880 static void sqlite3SetHasNullFlag(Vdbe *v, int iCur, int regHasNull){
002881 int addr1;
002882 sqlite3VdbeAddOp2(v, OP_Integer, 0, regHasNull);
002883 addr1 = sqlite3VdbeAddOp1(v, OP_Rewind, iCur); VdbeCoverage(v);
002884 sqlite3VdbeAddOp3(v, OP_Column, iCur, 0, regHasNull);
002885 sqlite3VdbeChangeP5(v, OPFLAG_TYPEOFARG);
002886 VdbeComment((v, "first_entry_in(%d)", iCur));
002887 sqlite3VdbeJumpHere(v, addr1);
002888 }
002889 #endif
002890
002891
002892 #ifndef SQLITE_OMIT_SUBQUERY
002893 /*
002894 ** The argument is an IN operator with a list (not a subquery) on the
002895 ** right-hand side. Return TRUE if that list is constant.
002896 */
002897 static int sqlite3InRhsIsConstant(Expr *pIn){
002898 Expr *pLHS;
002899 int res;
002900 assert( !ExprHasProperty(pIn, EP_xIsSelect) );
002901 pLHS = pIn->pLeft;
002902 pIn->pLeft = 0;
002903 res = sqlite3ExprIsConstant(pIn);
002904 pIn->pLeft = pLHS;
002905 return res;
002906 }
002907 #endif
002908
002909 /*
002910 ** This function is used by the implementation of the IN (...) operator.
002911 ** The pX parameter is the expression on the RHS of the IN operator, which
002912 ** might be either a list of expressions or a subquery.
002913 **
002914 ** The job of this routine is to find or create a b-tree object that can
002915 ** be used either to test for membership in the RHS set or to iterate through
002916 ** all members of the RHS set, skipping duplicates.
002917 **
002918 ** A cursor is opened on the b-tree object that is the RHS of the IN operator
002919 ** and the *piTab parameter is set to the index of that cursor.
002920 **
002921 ** The returned value of this function indicates the b-tree type, as follows:
002922 **
002923 ** IN_INDEX_ROWID - The cursor was opened on a database table.
002924 ** IN_INDEX_INDEX_ASC - The cursor was opened on an ascending index.
002925 ** IN_INDEX_INDEX_DESC - The cursor was opened on a descending index.
002926 ** IN_INDEX_EPH - The cursor was opened on a specially created and
002927 ** populated ephemeral table.
002928 ** IN_INDEX_NOOP - No cursor was allocated. The IN operator must be
002929 ** implemented as a sequence of comparisons.
002930 **
002931 ** An existing b-tree might be used if the RHS expression pX is a simple
002932 ** subquery such as:
002933 **
002934 ** SELECT <column1>, <column2>... FROM <table>
002935 **
002936 ** If the RHS of the IN operator is a list or a more complex subquery, then
002937 ** an ephemeral table might need to be generated from the RHS and then
002938 ** pX->iTable made to point to the ephemeral table instead of an
002939 ** existing table. In this case, the creation and initialization of the
002940 ** ephemeral table might be put inside of a subroutine, the EP_Subrtn flag
002941 ** will be set on pX and the pX->y.sub fields will be set to show where
002942 ** the subroutine is coded.
002943 **
002944 ** The inFlags parameter must contain, at a minimum, one of the bits
002945 ** IN_INDEX_MEMBERSHIP or IN_INDEX_LOOP but not both. If inFlags contains
002946 ** IN_INDEX_MEMBERSHIP, then the generated table will be used for a fast
002947 ** membership test. When the IN_INDEX_LOOP bit is set, the IN index will
002948 ** be used to loop over all values of the RHS of the IN operator.
002949 **
002950 ** When IN_INDEX_LOOP is used (and the b-tree will be used to iterate
002951 ** through the set members) then the b-tree must not contain duplicates.
002952 ** An ephemeral table will be created unless the selected columns are guaranteed
002953 ** to be unique - either because it is an INTEGER PRIMARY KEY or due to
002954 ** a UNIQUE constraint or index.
002955 **
002956 ** When IN_INDEX_MEMBERSHIP is used (and the b-tree will be used
002957 ** for fast set membership tests) then an ephemeral table must
002958 ** be used unless <columns> is a single INTEGER PRIMARY KEY column or an
002959 ** index can be found with the specified <columns> as its left-most.
002960 **
002961 ** If the IN_INDEX_NOOP_OK and IN_INDEX_MEMBERSHIP are both set and
002962 ** if the RHS of the IN operator is a list (not a subquery) then this
002963 ** routine might decide that creating an ephemeral b-tree for membership
002964 ** testing is too expensive and return IN_INDEX_NOOP. In that case, the
002965 ** calling routine should implement the IN operator using a sequence
002966 ** of Eq or Ne comparison operations.
002967 **
002968 ** When the b-tree is being used for membership tests, the calling function
002969 ** might need to know whether or not the RHS side of the IN operator
002970 ** contains a NULL. If prRhsHasNull is not a NULL pointer and
002971 ** if there is any chance that the (...) might contain a NULL value at
002972 ** runtime, then a register is allocated and the register number written
002973 ** to *prRhsHasNull. If there is no chance that the (...) contains a
002974 ** NULL value, then *prRhsHasNull is left unchanged.
002975 **
002976 ** If a register is allocated and its location stored in *prRhsHasNull, then
002977 ** the value in that register will be NULL if the b-tree contains one or more
002978 ** NULL values, and it will be some non-NULL value if the b-tree contains no
002979 ** NULL values.
002980 **
002981 ** If the aiMap parameter is not NULL, it must point to an array containing
002982 ** one element for each column returned by the SELECT statement on the RHS
002983 ** of the IN(...) operator. The i'th entry of the array is populated with the
002984 ** offset of the index column that matches the i'th column returned by the
002985 ** SELECT. For example, if the expression and selected index are:
002986 **
002987 ** (?,?,?) IN (SELECT a, b, c FROM t1)
002988 ** CREATE INDEX i1 ON t1(b, c, a);
002989 **
002990 ** then aiMap[] is populated with {2, 0, 1}.
002991 */
002992 #ifndef SQLITE_OMIT_SUBQUERY
002993 int sqlite3FindInIndex(
002994 Parse *pParse, /* Parsing context */
002995 Expr *pX, /* The IN expression */
002996 u32 inFlags, /* IN_INDEX_LOOP, _MEMBERSHIP, and/or _NOOP_OK */
002997 int *prRhsHasNull, /* Register holding NULL status. See notes */
002998 int *aiMap, /* Mapping from Index fields to RHS fields */
002999 int *piTab /* OUT: index to use */
003000 ){
003001 Select *p; /* SELECT to the right of IN operator */
003002 int eType = 0; /* Type of RHS table. IN_INDEX_* */
003003 int iTab; /* Cursor of the RHS table */
003004 int mustBeUnique; /* True if RHS must be unique */
003005 Vdbe *v = sqlite3GetVdbe(pParse); /* Virtual machine being coded */
003006
003007 assert( pX->op==TK_IN );
003008 mustBeUnique = (inFlags & IN_INDEX_LOOP)!=0;
003009 iTab = pParse->nTab++;
003010
003011 /* If the RHS of this IN(...) operator is a SELECT, and if it matters
003012 ** whether or not the SELECT result contains NULL values, check whether
003013 ** or not NULL is actually possible (it may not be, for example, due
003014 ** to NOT NULL constraints in the schema). If no NULL values are possible,
003015 ** set prRhsHasNull to 0 before continuing. */
003016 if( prRhsHasNull && ExprUseXSelect(pX) ){
003017 int i;
003018 ExprList *pEList = pX->x.pSelect->pEList;
003019 for(i=0; i<pEList->nExpr; i++){
003020 if( sqlite3ExprCanBeNull(pEList->a[i].pExpr) ) break;
003021 }
003022 if( i==pEList->nExpr ){
003023 prRhsHasNull = 0;
003024 }
003025 }
003026
003027 /* Check to see if an existing table or index can be used to
003028 ** satisfy the query. This is preferable to generating a new
003029 ** ephemeral table. */
003030 if( pParse->nErr==0 && (p = isCandidateForInOpt(pX))!=0 ){
003031 sqlite3 *db = pParse->db; /* Database connection */
003032 Table *pTab; /* Table <table>. */
003033 int iDb; /* Database idx for pTab */
003034 ExprList *pEList = p->pEList;
003035 int nExpr = pEList->nExpr;
003036
003037 assert( p->pEList!=0 ); /* Because of isCandidateForInOpt(p) */
003038 assert( p->pEList->a[0].pExpr!=0 ); /* Because of isCandidateForInOpt(p) */
003039 assert( p->pSrc!=0 ); /* Because of isCandidateForInOpt(p) */
003040 pTab = p->pSrc->a[0].pTab;
003041
003042 /* Code an OP_Transaction and OP_TableLock for <table>. */
003043 iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
003044 assert( iDb>=0 && iDb<SQLITE_MAX_DB );
003045 sqlite3CodeVerifySchema(pParse, iDb);
003046 sqlite3TableLock(pParse, iDb, pTab->tnum, 0, pTab->zName);
003047
003048 assert(v); /* sqlite3GetVdbe() has always been previously called */
003049 if( nExpr==1 && pEList->a[0].pExpr->iColumn<0 ){
003050 /* The "x IN (SELECT rowid FROM table)" case */
003051 int iAddr = sqlite3VdbeAddOp0(v, OP_Once);
003052 VdbeCoverage(v);
003053
003054 sqlite3OpenTable(pParse, iTab, iDb, pTab, OP_OpenRead);
003055 eType = IN_INDEX_ROWID;
003056 ExplainQueryPlan((pParse, 0,
003057 "USING ROWID SEARCH ON TABLE %s FOR IN-OPERATOR",pTab->zName));
003058 sqlite3VdbeJumpHere(v, iAddr);
003059 }else{
003060 Index *pIdx; /* Iterator variable */
003061 int affinity_ok = 1;
003062 int i;
003063
003064 /* Check that the affinity that will be used to perform each
003065 ** comparison is the same as the affinity of each column in table
003066 ** on the RHS of the IN operator. If it not, it is not possible to
003067 ** use any index of the RHS table. */
003068 for(i=0; i<nExpr && affinity_ok; i++){
003069 Expr *pLhs = sqlite3VectorFieldSubexpr(pX->pLeft, i);
003070 int iCol = pEList->a[i].pExpr->iColumn;
003071 char idxaff = sqlite3TableColumnAffinity(pTab,iCol); /* RHS table */
003072 char cmpaff = sqlite3CompareAffinity(pLhs, idxaff);
003073 testcase( cmpaff==SQLITE_AFF_BLOB );
003074 testcase( cmpaff==SQLITE_AFF_TEXT );
003075 switch( cmpaff ){
003076 case SQLITE_AFF_BLOB:
003077 break;
003078 case SQLITE_AFF_TEXT:
003079 /* sqlite3CompareAffinity() only returns TEXT if one side or the
003080 ** other has no affinity and the other side is TEXT. Hence,
003081 ** the only way for cmpaff to be TEXT is for idxaff to be TEXT
003082 ** and for the term on the LHS of the IN to have no affinity. */
003083 assert( idxaff==SQLITE_AFF_TEXT );
003084 break;
003085 default:
003086 affinity_ok = sqlite3IsNumericAffinity(idxaff);
003087 }
003088 }
003089
003090 if( affinity_ok ){
003091 /* Search for an existing index that will work for this IN operator */
003092 for(pIdx=pTab->pIndex; pIdx && eType==0; pIdx=pIdx->pNext){
003093 Bitmask colUsed; /* Columns of the index used */
003094 Bitmask mCol; /* Mask for the current column */
003095 if( pIdx->nColumn<nExpr ) continue;
003096 if( pIdx->pPartIdxWhere!=0 ) continue;
003097 /* Maximum nColumn is BMS-2, not BMS-1, so that we can compute
003098 ** BITMASK(nExpr) without overflowing */
003099 testcase( pIdx->nColumn==BMS-2 );
003100 testcase( pIdx->nColumn==BMS-1 );
003101 if( pIdx->nColumn>=BMS-1 ) continue;
003102 if( mustBeUnique ){
003103 if( pIdx->nKeyCol>nExpr
003104 ||(pIdx->nColumn>nExpr && !IsUniqueIndex(pIdx))
003105 ){
003106 continue; /* This index is not unique over the IN RHS columns */
003107 }
003108 }
003109
003110 colUsed = 0; /* Columns of index used so far */
003111 for(i=0; i<nExpr; i++){
003112 Expr *pLhs = sqlite3VectorFieldSubexpr(pX->pLeft, i);
003113 Expr *pRhs = pEList->a[i].pExpr;
003114 CollSeq *pReq = sqlite3BinaryCompareCollSeq(pParse, pLhs, pRhs);
003115 int j;
003116
003117 for(j=0; j<nExpr; j++){
003118 if( pIdx->aiColumn[j]!=pRhs->iColumn ) continue;
003119 assert( pIdx->azColl[j] );
003120 if( pReq!=0 && sqlite3StrICmp(pReq->zName, pIdx->azColl[j])!=0 ){
003121 continue;
003122 }
003123 break;
003124 }
003125 if( j==nExpr ) break;
003126 mCol = MASKBIT(j);
003127 if( mCol & colUsed ) break; /* Each column used only once */
003128 colUsed |= mCol;
003129 if( aiMap ) aiMap[i] = j;
003130 }
003131
003132 assert( i==nExpr || colUsed!=(MASKBIT(nExpr)-1) );
003133 if( colUsed==(MASKBIT(nExpr)-1) ){
003134 /* If we reach this point, that means the index pIdx is usable */
003135 int iAddr = sqlite3VdbeAddOp0(v, OP_Once); VdbeCoverage(v);
003136 ExplainQueryPlan((pParse, 0,
003137 "USING INDEX %s FOR IN-OPERATOR",pIdx->zName));
003138 sqlite3VdbeAddOp3(v, OP_OpenRead, iTab, pIdx->tnum, iDb);
003139 sqlite3VdbeSetP4KeyInfo(pParse, pIdx);
003140 VdbeComment((v, "%s", pIdx->zName));
003141 assert( IN_INDEX_INDEX_DESC == IN_INDEX_INDEX_ASC+1 );
003142 eType = IN_INDEX_INDEX_ASC + pIdx->aSortOrder[0];
003143
003144 if( prRhsHasNull ){
003145 #ifdef SQLITE_ENABLE_COLUMN_USED_MASK
003146 i64 mask = (1<<nExpr)-1;
003147 sqlite3VdbeAddOp4Dup8(v, OP_ColumnsUsed,
003148 iTab, 0, 0, (u8*)&mask, P4_INT64);
003149 #endif
003150 *prRhsHasNull = ++pParse->nMem;
003151 if( nExpr==1 ){
003152 sqlite3SetHasNullFlag(v, iTab, *prRhsHasNull);
003153 }
003154 }
003155 sqlite3VdbeJumpHere(v, iAddr);
003156 }
003157 } /* End loop over indexes */
003158 } /* End if( affinity_ok ) */
003159 } /* End if not an rowid index */
003160 } /* End attempt to optimize using an index */
003161
003162 /* If no preexisting index is available for the IN clause
003163 ** and IN_INDEX_NOOP is an allowed reply
003164 ** and the RHS of the IN operator is a list, not a subquery
003165 ** and the RHS is not constant or has two or fewer terms,
003166 ** then it is not worth creating an ephemeral table to evaluate
003167 ** the IN operator so return IN_INDEX_NOOP.
003168 */
003169 if( eType==0
003170 && (inFlags & IN_INDEX_NOOP_OK)
003171 && ExprUseXList(pX)
003172 && (!sqlite3InRhsIsConstant(pX) || pX->x.pList->nExpr<=2)
003173 ){
003174 pParse->nTab--; /* Back out the allocation of the unused cursor */
003175 iTab = -1; /* Cursor is not allocated */
003176 eType = IN_INDEX_NOOP;
003177 }
003178
003179 if( eType==0 ){
003180 /* Could not find an existing table or index to use as the RHS b-tree.
003181 ** We will have to generate an ephemeral table to do the job.
003182 */
003183 u32 savedNQueryLoop = pParse->nQueryLoop;
003184 int rMayHaveNull = 0;
003185 eType = IN_INDEX_EPH;
003186 if( inFlags & IN_INDEX_LOOP ){
003187 pParse->nQueryLoop = 0;
003188 }else if( prRhsHasNull ){
003189 *prRhsHasNull = rMayHaveNull = ++pParse->nMem;
003190 }
003191 assert( pX->op==TK_IN );
003192 sqlite3CodeRhsOfIN(pParse, pX, iTab);
003193 if( rMayHaveNull ){
003194 sqlite3SetHasNullFlag(v, iTab, rMayHaveNull);
003195 }
003196 pParse->nQueryLoop = savedNQueryLoop;
003197 }
003198
003199 if( aiMap && eType!=IN_INDEX_INDEX_ASC && eType!=IN_INDEX_INDEX_DESC ){
003200 int i, n;
003201 n = sqlite3ExprVectorSize(pX->pLeft);
003202 for(i=0; i<n; i++) aiMap[i] = i;
003203 }
003204 *piTab = iTab;
003205 return eType;
003206 }
003207 #endif
003208
003209 #ifndef SQLITE_OMIT_SUBQUERY
003210 /*
003211 ** Argument pExpr is an (?, ?...) IN(...) expression. This
003212 ** function allocates and returns a nul-terminated string containing
003213 ** the affinities to be used for each column of the comparison.
003214 **
003215 ** It is the responsibility of the caller to ensure that the returned
003216 ** string is eventually freed using sqlite3DbFree().
003217 */
003218 static char *exprINAffinity(Parse *pParse, const Expr *pExpr){
003219 Expr *pLeft = pExpr->pLeft;
003220 int nVal = sqlite3ExprVectorSize(pLeft);
003221 Select *pSelect = ExprUseXSelect(pExpr) ? pExpr->x.pSelect : 0;
003222 char *zRet;
003223
003224 assert( pExpr->op==TK_IN );
003225 zRet = sqlite3DbMallocRaw(pParse->db, nVal+1);
003226 if( zRet ){
003227 int i;
003228 for(i=0; i<nVal; i++){
003229 Expr *pA = sqlite3VectorFieldSubexpr(pLeft, i);
003230 char a = sqlite3ExprAffinity(pA);
003231 if( pSelect ){
003232 zRet[i] = sqlite3CompareAffinity(pSelect->pEList->a[i].pExpr, a);
003233 }else{
003234 zRet[i] = a;
003235 }
003236 }
003237 zRet[nVal] = '\0';
003238 }
003239 return zRet;
003240 }
003241 #endif
003242
003243 #ifndef SQLITE_OMIT_SUBQUERY
003244 /*
003245 ** Load the Parse object passed as the first argument with an error
003246 ** message of the form:
003247 **
003248 ** "sub-select returns N columns - expected M"
003249 */
003250 void sqlite3SubselectError(Parse *pParse, int nActual, int nExpect){
003251 if( pParse->nErr==0 ){
003252 const char *zFmt = "sub-select returns %d columns - expected %d";
003253 sqlite3ErrorMsg(pParse, zFmt, nActual, nExpect);
003254 }
003255 }
003256 #endif
003257
003258 /*
003259 ** Expression pExpr is a vector that has been used in a context where
003260 ** it is not permitted. If pExpr is a sub-select vector, this routine
003261 ** loads the Parse object with a message of the form:
003262 **
003263 ** "sub-select returns N columns - expected 1"
003264 **
003265 ** Or, if it is a regular scalar vector:
003266 **
003267 ** "row value misused"
003268 */
003269 void sqlite3VectorErrorMsg(Parse *pParse, Expr *pExpr){
003270 #ifndef SQLITE_OMIT_SUBQUERY
003271 if( ExprUseXSelect(pExpr) ){
003272 sqlite3SubselectError(pParse, pExpr->x.pSelect->pEList->nExpr, 1);
003273 }else
003274 #endif
003275 {
003276 sqlite3ErrorMsg(pParse, "row value misused");
003277 }
003278 }
003279
003280 #ifndef SQLITE_OMIT_SUBQUERY
003281 /*
003282 ** Generate code that will construct an ephemeral table containing all terms
003283 ** in the RHS of an IN operator. The IN operator can be in either of two
003284 ** forms:
003285 **
003286 ** x IN (4,5,11) -- IN operator with list on right-hand side
003287 ** x IN (SELECT a FROM b) -- IN operator with subquery on the right
003288 **
003289 ** The pExpr parameter is the IN operator. The cursor number for the
003290 ** constructed ephemeral table is returned. The first time the ephemeral
003291 ** table is computed, the cursor number is also stored in pExpr->iTable,
003292 ** however the cursor number returned might not be the same, as it might
003293 ** have been duplicated using OP_OpenDup.
003294 **
003295 ** If the LHS expression ("x" in the examples) is a column value, or
003296 ** the SELECT statement returns a column value, then the affinity of that
003297 ** column is used to build the index keys. If both 'x' and the
003298 ** SELECT... statement are columns, then numeric affinity is used
003299 ** if either column has NUMERIC or INTEGER affinity. If neither
003300 ** 'x' nor the SELECT... statement are columns, then numeric affinity
003301 ** is used.
003302 */
003303 void sqlite3CodeRhsOfIN(
003304 Parse *pParse, /* Parsing context */
003305 Expr *pExpr, /* The IN operator */
003306 int iTab /* Use this cursor number */
003307 ){
003308 int addrOnce = 0; /* Address of the OP_Once instruction at top */
003309 int addr; /* Address of OP_OpenEphemeral instruction */
003310 Expr *pLeft; /* the LHS of the IN operator */
003311 KeyInfo *pKeyInfo = 0; /* Key information */
003312 int nVal; /* Size of vector pLeft */
003313 Vdbe *v; /* The prepared statement under construction */
003314
003315 v = pParse->pVdbe;
003316 assert( v!=0 );
003317
003318 /* The evaluation of the IN must be repeated every time it
003319 ** is encountered if any of the following is true:
003320 **
003321 ** * The right-hand side is a correlated subquery
003322 ** * The right-hand side is an expression list containing variables
003323 ** * We are inside a trigger
003324 **
003325 ** If all of the above are false, then we can compute the RHS just once
003326 ** and reuse it many names.
003327 */
003328 if( !ExprHasProperty(pExpr, EP_VarSelect) && pParse->iSelfTab==0 ){
003329 /* Reuse of the RHS is allowed */
003330 /* If this routine has already been coded, but the previous code
003331 ** might not have been invoked yet, so invoke it now as a subroutine.
003332 */
003333 if( ExprHasProperty(pExpr, EP_Subrtn) ){
003334 addrOnce = sqlite3VdbeAddOp0(v, OP_Once); VdbeCoverage(v);
003335 if( ExprUseXSelect(pExpr) ){
003336 ExplainQueryPlan((pParse, 0, "REUSE LIST SUBQUERY %d",
003337 pExpr->x.pSelect->selId));
003338 }
003339 assert( ExprUseYSub(pExpr) );
003340 sqlite3VdbeAddOp2(v, OP_Gosub, pExpr->y.sub.regReturn,
003341 pExpr->y.sub.iAddr);
003342 assert( iTab!=pExpr->iTable );
003343 sqlite3VdbeAddOp2(v, OP_OpenDup, iTab, pExpr->iTable);
003344 sqlite3VdbeJumpHere(v, addrOnce);
003345 return;
003346 }
003347
003348 /* Begin coding the subroutine */
003349 assert( !ExprUseYWin(pExpr) );
003350 ExprSetProperty(pExpr, EP_Subrtn);
003351 assert( !ExprHasProperty(pExpr, EP_TokenOnly|EP_Reduced) );
003352 pExpr->y.sub.regReturn = ++pParse->nMem;
003353 pExpr->y.sub.iAddr =
003354 sqlite3VdbeAddOp2(v, OP_BeginSubrtn, 0, pExpr->y.sub.regReturn) + 1;
003355
003356 addrOnce = sqlite3VdbeAddOp0(v, OP_Once); VdbeCoverage(v);
003357 }
003358
003359 /* Check to see if this is a vector IN operator */
003360 pLeft = pExpr->pLeft;
003361 nVal = sqlite3ExprVectorSize(pLeft);
003362
003363 /* Construct the ephemeral table that will contain the content of
003364 ** RHS of the IN operator.
003365 */
003366 pExpr->iTable = iTab;
003367 addr = sqlite3VdbeAddOp2(v, OP_OpenEphemeral, pExpr->iTable, nVal);
003368 #ifdef SQLITE_ENABLE_EXPLAIN_COMMENTS
003369 if( ExprUseXSelect(pExpr) ){
003370 VdbeComment((v, "Result of SELECT %u", pExpr->x.pSelect->selId));
003371 }else{
003372 VdbeComment((v, "RHS of IN operator"));
003373 }
003374 #endif
003375 pKeyInfo = sqlite3KeyInfoAlloc(pParse->db, nVal, 1);
003376
003377 if( ExprUseXSelect(pExpr) ){
003378 /* Case 1: expr IN (SELECT ...)
003379 **
003380 ** Generate code to write the results of the select into the temporary
003381 ** table allocated and opened above.
003382 */
003383 Select *pSelect = pExpr->x.pSelect;
003384 ExprList *pEList = pSelect->pEList;
003385
003386 ExplainQueryPlan((pParse, 1, "%sLIST SUBQUERY %d",
003387 addrOnce?"":"CORRELATED ", pSelect->selId
003388 ));
003389 /* If the LHS and RHS of the IN operator do not match, that
003390 ** error will have been caught long before we reach this point. */
003391 if( ALWAYS(pEList->nExpr==nVal) ){
003392 Select *pCopy;
003393 SelectDest dest;
003394 int i;
003395 int rc;
003396 sqlite3SelectDestInit(&dest, SRT_Set, iTab);
003397 dest.zAffSdst = exprINAffinity(pParse, pExpr);
003398 pSelect->iLimit = 0;
003399 testcase( pSelect->selFlags & SF_Distinct );
003400 testcase( pKeyInfo==0 ); /* Caused by OOM in sqlite3KeyInfoAlloc() */
003401 pCopy = sqlite3SelectDup(pParse->db, pSelect, 0);
003402 rc = pParse->db->mallocFailed ? 1 :sqlite3Select(pParse, pCopy, &dest);
003403 sqlite3SelectDelete(pParse->db, pCopy);
003404 sqlite3DbFree(pParse->db, dest.zAffSdst);
003405 if( rc ){
003406 sqlite3KeyInfoUnref(pKeyInfo);
003407 return;
003408 }
003409 assert( pKeyInfo!=0 ); /* OOM will cause exit after sqlite3Select() */
003410 assert( pEList!=0 );
003411 assert( pEList->nExpr>0 );
003412 assert( sqlite3KeyInfoIsWriteable(pKeyInfo) );
003413 for(i=0; i<nVal; i++){
003414 Expr *p = sqlite3VectorFieldSubexpr(pLeft, i);
003415 pKeyInfo->aColl[i] = sqlite3BinaryCompareCollSeq(
003416 pParse, p, pEList->a[i].pExpr
003417 );
003418 }
003419 }
003420 }else if( ALWAYS(pExpr->x.pList!=0) ){
003421 /* Case 2: expr IN (exprlist)
003422 **
003423 ** For each expression, build an index key from the evaluation and
003424 ** store it in the temporary table. If <expr> is a column, then use
003425 ** that columns affinity when building index keys. If <expr> is not
003426 ** a column, use numeric affinity.
003427 */
003428 char affinity; /* Affinity of the LHS of the IN */
003429 int i;
003430 ExprList *pList = pExpr->x.pList;
003431 struct ExprList_item *pItem;
003432 int r1, r2;
003433 affinity = sqlite3ExprAffinity(pLeft);
003434 if( affinity<=SQLITE_AFF_NONE ){
003435 affinity = SQLITE_AFF_BLOB;
003436 }else if( affinity==SQLITE_AFF_REAL ){
003437 affinity = SQLITE_AFF_NUMERIC;
003438 }
003439 if( pKeyInfo ){
003440 assert( sqlite3KeyInfoIsWriteable(pKeyInfo) );
003441 pKeyInfo->aColl[0] = sqlite3ExprCollSeq(pParse, pExpr->pLeft);
003442 }
003443
003444 /* Loop through each expression in <exprlist>. */
003445 r1 = sqlite3GetTempReg(pParse);
003446 r2 = sqlite3GetTempReg(pParse);
003447 for(i=pList->nExpr, pItem=pList->a; i>0; i--, pItem++){
003448 Expr *pE2 = pItem->pExpr;
003449
003450 /* If the expression is not constant then we will need to
003451 ** disable the test that was generated above that makes sure
003452 ** this code only executes once. Because for a non-constant
003453 ** expression we need to rerun this code each time.
003454 */
003455 if( addrOnce && !sqlite3ExprIsConstant(pE2) ){
003456 sqlite3VdbeChangeToNoop(v, addrOnce-1);
003457 sqlite3VdbeChangeToNoop(v, addrOnce);
003458 ExprClearProperty(pExpr, EP_Subrtn);
003459 addrOnce = 0;
003460 }
003461
003462 /* Evaluate the expression and insert it into the temp table */
003463 sqlite3ExprCode(pParse, pE2, r1);
003464 sqlite3VdbeAddOp4(v, OP_MakeRecord, r1, 1, r2, &affinity, 1);
003465 sqlite3VdbeAddOp4Int(v, OP_IdxInsert, iTab, r2, r1, 1);
003466 }
003467 sqlite3ReleaseTempReg(pParse, r1);
003468 sqlite3ReleaseTempReg(pParse, r2);
003469 }
003470 if( pKeyInfo ){
003471 sqlite3VdbeChangeP4(v, addr, (void *)pKeyInfo, P4_KEYINFO);
003472 }
003473 if( addrOnce ){
003474 sqlite3VdbeAddOp1(v, OP_NullRow, iTab);
003475 sqlite3VdbeJumpHere(v, addrOnce);
003476 /* Subroutine return */
003477 assert( ExprUseYSub(pExpr) );
003478 assert( sqlite3VdbeGetOp(v,pExpr->y.sub.iAddr-1)->opcode==OP_BeginSubrtn
003479 || pParse->nErr );
003480 sqlite3VdbeAddOp3(v, OP_Return, pExpr->y.sub.regReturn,
003481 pExpr->y.sub.iAddr, 1);
003482 VdbeCoverage(v);
003483 sqlite3ClearTempRegCache(pParse);
003484 }
003485 }
003486 #endif /* SQLITE_OMIT_SUBQUERY */
003487
003488 /*
003489 ** Generate code for scalar subqueries used as a subquery expression
003490 ** or EXISTS operator:
003491 **
003492 ** (SELECT a FROM b) -- subquery
003493 ** EXISTS (SELECT a FROM b) -- EXISTS subquery
003494 **
003495 ** The pExpr parameter is the SELECT or EXISTS operator to be coded.
003496 **
003497 ** Return the register that holds the result. For a multi-column SELECT,
003498 ** the result is stored in a contiguous array of registers and the
003499 ** return value is the register of the left-most result column.
003500 ** Return 0 if an error occurs.
003501 */
003502 #ifndef SQLITE_OMIT_SUBQUERY
003503 int sqlite3CodeSubselect(Parse *pParse, Expr *pExpr){
003504 int addrOnce = 0; /* Address of OP_Once at top of subroutine */
003505 int rReg = 0; /* Register storing resulting */
003506 Select *pSel; /* SELECT statement to encode */
003507 SelectDest dest; /* How to deal with SELECT result */
003508 int nReg; /* Registers to allocate */
003509 Expr *pLimit; /* New limit expression */
003510 #ifdef SQLITE_ENABLE_STMT_SCANSTATUS
003511 int addrExplain; /* Address of OP_Explain instruction */
003512 #endif
003513
003514 Vdbe *v = pParse->pVdbe;
003515 assert( v!=0 );
003516 if( pParse->nErr ) return 0;
003517 testcase( pExpr->op==TK_EXISTS );
003518 testcase( pExpr->op==TK_SELECT );
003519 assert( pExpr->op==TK_EXISTS || pExpr->op==TK_SELECT );
003520 assert( ExprUseXSelect(pExpr) );
003521 pSel = pExpr->x.pSelect;
003522
003523 /* If this routine has already been coded, then invoke it as a
003524 ** subroutine. */
003525 if( ExprHasProperty(pExpr, EP_Subrtn) ){
003526 ExplainQueryPlan((pParse, 0, "REUSE SUBQUERY %d", pSel->selId));
003527 assert( ExprUseYSub(pExpr) );
003528 sqlite3VdbeAddOp2(v, OP_Gosub, pExpr->y.sub.regReturn,
003529 pExpr->y.sub.iAddr);
003530 return pExpr->iTable;
003531 }
003532
003533 /* Begin coding the subroutine */
003534 assert( !ExprUseYWin(pExpr) );
003535 assert( !ExprHasProperty(pExpr, EP_Reduced|EP_TokenOnly) );
003536 ExprSetProperty(pExpr, EP_Subrtn);
003537 pExpr->y.sub.regReturn = ++pParse->nMem;
003538 pExpr->y.sub.iAddr =
003539 sqlite3VdbeAddOp2(v, OP_BeginSubrtn, 0, pExpr->y.sub.regReturn) + 1;
003540
003541 /* The evaluation of the EXISTS/SELECT must be repeated every time it
003542 ** is encountered if any of the following is true:
003543 **
003544 ** * The right-hand side is a correlated subquery
003545 ** * The right-hand side is an expression list containing variables
003546 ** * We are inside a trigger
003547 **
003548 ** If all of the above are false, then we can run this code just once
003549 ** save the results, and reuse the same result on subsequent invocations.
003550 */
003551 if( !ExprHasProperty(pExpr, EP_VarSelect) ){
003552 addrOnce = sqlite3VdbeAddOp0(v, OP_Once); VdbeCoverage(v);
003553 }
003554
003555 /* For a SELECT, generate code to put the values for all columns of
003556 ** the first row into an array of registers and return the index of
003557 ** the first register.
003558 **
003559 ** If this is an EXISTS, write an integer 0 (not exists) or 1 (exists)
003560 ** into a register and return that register number.
003561 **
003562 ** In both cases, the query is augmented with "LIMIT 1". Any
003563 ** preexisting limit is discarded in place of the new LIMIT 1.
003564 */
003565 ExplainQueryPlan2(addrExplain, (pParse, 1, "%sSCALAR SUBQUERY %d",
003566 addrOnce?"":"CORRELATED ", pSel->selId));
003567 sqlite3VdbeScanStatusCounters(v, addrExplain, addrExplain, -1);
003568 nReg = pExpr->op==TK_SELECT ? pSel->pEList->nExpr : 1;
003569 sqlite3SelectDestInit(&dest, 0, pParse->nMem+1);
003570 pParse->nMem += nReg;
003571 if( pExpr->op==TK_SELECT ){
003572 dest.eDest = SRT_Mem;
003573 dest.iSdst = dest.iSDParm;
003574 dest.nSdst = nReg;
003575 sqlite3VdbeAddOp3(v, OP_Null, 0, dest.iSDParm, dest.iSDParm+nReg-1);
003576 VdbeComment((v, "Init subquery result"));
003577 }else{
003578 dest.eDest = SRT_Exists;
003579 sqlite3VdbeAddOp2(v, OP_Integer, 0, dest.iSDParm);
003580 VdbeComment((v, "Init EXISTS result"));
003581 }
003582 if( pSel->pLimit ){
003583 /* The subquery already has a limit. If the pre-existing limit is X
003584 ** then make the new limit X<>0 so that the new limit is either 1 or 0 */
003585 sqlite3 *db = pParse->db;
003586 pLimit = sqlite3Expr(db, TK_INTEGER, "0");
003587 if( pLimit ){
003588 pLimit->affExpr = SQLITE_AFF_NUMERIC;
003589 pLimit = sqlite3PExpr(pParse, TK_NE,
003590 sqlite3ExprDup(db, pSel->pLimit->pLeft, 0), pLimit);
003591 }
003592 sqlite3ExprDeferredDelete(pParse, pSel->pLimit->pLeft);
003593 pSel->pLimit->pLeft = pLimit;
003594 }else{
003595 /* If there is no pre-existing limit add a limit of 1 */
003596 pLimit = sqlite3Expr(pParse->db, TK_INTEGER, "1");
003597 pSel->pLimit = sqlite3PExpr(pParse, TK_LIMIT, pLimit, 0);
003598 }
003599 pSel->iLimit = 0;
003600 if( sqlite3Select(pParse, pSel, &dest) ){
003601 pExpr->op2 = pExpr->op;
003602 pExpr->op = TK_ERROR;
003603 return 0;
003604 }
003605 pExpr->iTable = rReg = dest.iSDParm;
003606 ExprSetVVAProperty(pExpr, EP_NoReduce);
003607 if( addrOnce ){
003608 sqlite3VdbeJumpHere(v, addrOnce);
003609 }
003610 sqlite3VdbeScanStatusRange(v, addrExplain, addrExplain, -1);
003611
003612 /* Subroutine return */
003613 assert( ExprUseYSub(pExpr) );
003614 assert( sqlite3VdbeGetOp(v,pExpr->y.sub.iAddr-1)->opcode==OP_BeginSubrtn
003615 || pParse->nErr );
003616 sqlite3VdbeAddOp3(v, OP_Return, pExpr->y.sub.regReturn,
003617 pExpr->y.sub.iAddr, 1);
003618 VdbeCoverage(v);
003619 sqlite3ClearTempRegCache(pParse);
003620 return rReg;
003621 }
003622 #endif /* SQLITE_OMIT_SUBQUERY */
003623
003624 #ifndef SQLITE_OMIT_SUBQUERY
003625 /*
003626 ** Expr pIn is an IN(...) expression. This function checks that the
003627 ** sub-select on the RHS of the IN() operator has the same number of
003628 ** columns as the vector on the LHS. Or, if the RHS of the IN() is not
003629 ** a sub-query, that the LHS is a vector of size 1.
003630 */
003631 int sqlite3ExprCheckIN(Parse *pParse, Expr *pIn){
003632 int nVector = sqlite3ExprVectorSize(pIn->pLeft);
003633 if( ExprUseXSelect(pIn) && !pParse->db->mallocFailed ){
003634 if( nVector!=pIn->x.pSelect->pEList->nExpr ){
003635 sqlite3SubselectError(pParse, pIn->x.pSelect->pEList->nExpr, nVector);
003636 return 1;
003637 }
003638 }else if( nVector!=1 ){
003639 sqlite3VectorErrorMsg(pParse, pIn->pLeft);
003640 return 1;
003641 }
003642 return 0;
003643 }
003644 #endif
003645
003646 #ifndef SQLITE_OMIT_SUBQUERY
003647 /*
003648 ** Generate code for an IN expression.
003649 **
003650 ** x IN (SELECT ...)
003651 ** x IN (value, value, ...)
003652 **
003653 ** The left-hand side (LHS) is a scalar or vector expression. The
003654 ** right-hand side (RHS) is an array of zero or more scalar values, or a
003655 ** subquery. If the RHS is a subquery, the number of result columns must
003656 ** match the number of columns in the vector on the LHS. If the RHS is
003657 ** a list of values, the LHS must be a scalar.
003658 **
003659 ** The IN operator is true if the LHS value is contained within the RHS.
003660 ** The result is false if the LHS is definitely not in the RHS. The
003661 ** result is NULL if the presence of the LHS in the RHS cannot be
003662 ** determined due to NULLs.
003663 **
003664 ** This routine generates code that jumps to destIfFalse if the LHS is not
003665 ** contained within the RHS. If due to NULLs we cannot determine if the LHS
003666 ** is contained in the RHS then jump to destIfNull. If the LHS is contained
003667 ** within the RHS then fall through.
003668 **
003669 ** See the separate in-operator.md documentation file in the canonical
003670 ** SQLite source tree for additional information.
003671 */
003672 static void sqlite3ExprCodeIN(
003673 Parse *pParse, /* Parsing and code generating context */
003674 Expr *pExpr, /* The IN expression */
003675 int destIfFalse, /* Jump here if LHS is not contained in the RHS */
003676 int destIfNull /* Jump here if the results are unknown due to NULLs */
003677 ){
003678 int rRhsHasNull = 0; /* Register that is true if RHS contains NULL values */
003679 int eType; /* Type of the RHS */
003680 int rLhs; /* Register(s) holding the LHS values */
003681 int rLhsOrig; /* LHS values prior to reordering by aiMap[] */
003682 Vdbe *v; /* Statement under construction */
003683 int *aiMap = 0; /* Map from vector field to index column */
003684 char *zAff = 0; /* Affinity string for comparisons */
003685 int nVector; /* Size of vectors for this IN operator */
003686 int iDummy; /* Dummy parameter to exprCodeVector() */
003687 Expr *pLeft; /* The LHS of the IN operator */
003688 int i; /* loop counter */
003689 int destStep2; /* Where to jump when NULLs seen in step 2 */
003690 int destStep6 = 0; /* Start of code for Step 6 */
003691 int addrTruthOp; /* Address of opcode that determines the IN is true */
003692 int destNotNull; /* Jump here if a comparison is not true in step 6 */
003693 int addrTop; /* Top of the step-6 loop */
003694 int iTab = 0; /* Index to use */
003695 u8 okConstFactor = pParse->okConstFactor;
003696
003697 assert( !ExprHasVVAProperty(pExpr,EP_Immutable) );
003698 pLeft = pExpr->pLeft;
003699 if( sqlite3ExprCheckIN(pParse, pExpr) ) return;
003700 zAff = exprINAffinity(pParse, pExpr);
003701 nVector = sqlite3ExprVectorSize(pExpr->pLeft);
003702 aiMap = (int*)sqlite3DbMallocZero(
003703 pParse->db, nVector*(sizeof(int) + sizeof(char)) + 1
003704 );
003705 if( pParse->db->mallocFailed ) goto sqlite3ExprCodeIN_oom_error;
003706
003707 /* Attempt to compute the RHS. After this step, if anything other than
003708 ** IN_INDEX_NOOP is returned, the table opened with cursor iTab
003709 ** contains the values that make up the RHS. If IN_INDEX_NOOP is returned,
003710 ** the RHS has not yet been coded. */
003711 v = pParse->pVdbe;
003712 assert( v!=0 ); /* OOM detected prior to this routine */
003713 VdbeNoopComment((v, "begin IN expr"));
003714 eType = sqlite3FindInIndex(pParse, pExpr,
003715 IN_INDEX_MEMBERSHIP | IN_INDEX_NOOP_OK,
003716 destIfFalse==destIfNull ? 0 : &rRhsHasNull,
003717 aiMap, &iTab);
003718
003719 assert( pParse->nErr || nVector==1 || eType==IN_INDEX_EPH
003720 || eType==IN_INDEX_INDEX_ASC || eType==IN_INDEX_INDEX_DESC
003721 );
003722 #ifdef SQLITE_DEBUG
003723 /* Confirm that aiMap[] contains nVector integer values between 0 and
003724 ** nVector-1. */
003725 for(i=0; i<nVector; i++){
003726 int j, cnt;
003727 for(cnt=j=0; j<nVector; j++) if( aiMap[j]==i ) cnt++;
003728 assert( cnt==1 );
003729 }
003730 #endif
003731
003732 /* Code the LHS, the <expr> from "<expr> IN (...)". If the LHS is a
003733 ** vector, then it is stored in an array of nVector registers starting
003734 ** at r1.
003735 **
003736 ** sqlite3FindInIndex() might have reordered the fields of the LHS vector
003737 ** so that the fields are in the same order as an existing index. The
003738 ** aiMap[] array contains a mapping from the original LHS field order to
003739 ** the field order that matches the RHS index.
003740 **
003741 ** Avoid factoring the LHS of the IN(...) expression out of the loop,
003742 ** even if it is constant, as OP_Affinity may be used on the register
003743 ** by code generated below. */
003744 assert( pParse->okConstFactor==okConstFactor );
003745 pParse->okConstFactor = 0;
003746 rLhsOrig = exprCodeVector(pParse, pLeft, &iDummy);
003747 pParse->okConstFactor = okConstFactor;
003748 for(i=0; i<nVector && aiMap[i]==i; i++){} /* Are LHS fields reordered? */
003749 if( i==nVector ){
003750 /* LHS fields are not reordered */
003751 rLhs = rLhsOrig;
003752 }else{
003753 /* Need to reorder the LHS fields according to aiMap */
003754 rLhs = sqlite3GetTempRange(pParse, nVector);
003755 for(i=0; i<nVector; i++){
003756 sqlite3VdbeAddOp3(v, OP_Copy, rLhsOrig+i, rLhs+aiMap[i], 0);
003757 }
003758 }
003759
003760 /* If sqlite3FindInIndex() did not find or create an index that is
003761 ** suitable for evaluating the IN operator, then evaluate using a
003762 ** sequence of comparisons.
003763 **
003764 ** This is step (1) in the in-operator.md optimized algorithm.
003765 */
003766 if( eType==IN_INDEX_NOOP ){
003767 ExprList *pList;
003768 CollSeq *pColl;
003769 int labelOk = sqlite3VdbeMakeLabel(pParse);
003770 int r2, regToFree;
003771 int regCkNull = 0;
003772 int ii;
003773 assert( ExprUseXList(pExpr) );
003774 pList = pExpr->x.pList;
003775 pColl = sqlite3ExprCollSeq(pParse, pExpr->pLeft);
003776 if( destIfNull!=destIfFalse ){
003777 regCkNull = sqlite3GetTempReg(pParse);
003778 sqlite3VdbeAddOp3(v, OP_BitAnd, rLhs, rLhs, regCkNull);
003779 }
003780 for(ii=0; ii<pList->nExpr; ii++){
003781 r2 = sqlite3ExprCodeTemp(pParse, pList->a[ii].pExpr, ®ToFree);
003782 if( regCkNull && sqlite3ExprCanBeNull(pList->a[ii].pExpr) ){
003783 sqlite3VdbeAddOp3(v, OP_BitAnd, regCkNull, r2, regCkNull);
003784 }
003785 sqlite3ReleaseTempReg(pParse, regToFree);
003786 if( ii<pList->nExpr-1 || destIfNull!=destIfFalse ){
003787 int op = rLhs!=r2 ? OP_Eq : OP_NotNull;
003788 sqlite3VdbeAddOp4(v, op, rLhs, labelOk, r2,
003789 (void*)pColl, P4_COLLSEQ);
003790 VdbeCoverageIf(v, ii<pList->nExpr-1 && op==OP_Eq);
003791 VdbeCoverageIf(v, ii==pList->nExpr-1 && op==OP_Eq);
003792 VdbeCoverageIf(v, ii<pList->nExpr-1 && op==OP_NotNull);
003793 VdbeCoverageIf(v, ii==pList->nExpr-1 && op==OP_NotNull);
003794 sqlite3VdbeChangeP5(v, zAff[0]);
003795 }else{
003796 int op = rLhs!=r2 ? OP_Ne : OP_IsNull;
003797 assert( destIfNull==destIfFalse );
003798 sqlite3VdbeAddOp4(v, op, rLhs, destIfFalse, r2,
003799 (void*)pColl, P4_COLLSEQ);
003800 VdbeCoverageIf(v, op==OP_Ne);
003801 VdbeCoverageIf(v, op==OP_IsNull);
003802 sqlite3VdbeChangeP5(v, zAff[0] | SQLITE_JUMPIFNULL);
003803 }
003804 }
003805 if( regCkNull ){
003806 sqlite3VdbeAddOp2(v, OP_IsNull, regCkNull, destIfNull); VdbeCoverage(v);
003807 sqlite3VdbeGoto(v, destIfFalse);
003808 }
003809 sqlite3VdbeResolveLabel(v, labelOk);
003810 sqlite3ReleaseTempReg(pParse, regCkNull);
003811 goto sqlite3ExprCodeIN_finished;
003812 }
003813
003814 /* Step 2: Check to see if the LHS contains any NULL columns. If the
003815 ** LHS does contain NULLs then the result must be either FALSE or NULL.
003816 ** We will then skip the binary search of the RHS.
003817 */
003818 if( destIfNull==destIfFalse ){
003819 destStep2 = destIfFalse;
003820 }else{
003821 destStep2 = destStep6 = sqlite3VdbeMakeLabel(pParse);
003822 }
003823 for(i=0; i<nVector; i++){
003824 Expr *p = sqlite3VectorFieldSubexpr(pExpr->pLeft, i);
003825 if( pParse->nErr ) goto sqlite3ExprCodeIN_oom_error;
003826 if( sqlite3ExprCanBeNull(p) ){
003827 sqlite3VdbeAddOp2(v, OP_IsNull, rLhs+i, destStep2);
003828 VdbeCoverage(v);
003829 }
003830 }
003831
003832 /* Step 3. The LHS is now known to be non-NULL. Do the binary search
003833 ** of the RHS using the LHS as a probe. If found, the result is
003834 ** true.
003835 */
003836 if( eType==IN_INDEX_ROWID ){
003837 /* In this case, the RHS is the ROWID of table b-tree and so we also
003838 ** know that the RHS is non-NULL. Hence, we combine steps 3 and 4
003839 ** into a single opcode. */
003840 sqlite3VdbeAddOp3(v, OP_SeekRowid, iTab, destIfFalse, rLhs);
003841 VdbeCoverage(v);
003842 addrTruthOp = sqlite3VdbeAddOp0(v, OP_Goto); /* Return True */
003843 }else{
003844 sqlite3VdbeAddOp4(v, OP_Affinity, rLhs, nVector, 0, zAff, nVector);
003845 if( destIfFalse==destIfNull ){
003846 /* Combine Step 3 and Step 5 into a single opcode */
003847 sqlite3VdbeAddOp4Int(v, OP_NotFound, iTab, destIfFalse,
003848 rLhs, nVector); VdbeCoverage(v);
003849 goto sqlite3ExprCodeIN_finished;
003850 }
003851 /* Ordinary Step 3, for the case where FALSE and NULL are distinct */
003852 addrTruthOp = sqlite3VdbeAddOp4Int(v, OP_Found, iTab, 0,
003853 rLhs, nVector); VdbeCoverage(v);
003854 }
003855
003856 /* Step 4. If the RHS is known to be non-NULL and we did not find
003857 ** an match on the search above, then the result must be FALSE.
003858 */
003859 if( rRhsHasNull && nVector==1 ){
003860 sqlite3VdbeAddOp2(v, OP_NotNull, rRhsHasNull, destIfFalse);
003861 VdbeCoverage(v);
003862 }
003863
003864 /* Step 5. If we do not care about the difference between NULL and
003865 ** FALSE, then just return false.
003866 */
003867 if( destIfFalse==destIfNull ) sqlite3VdbeGoto(v, destIfFalse);
003868
003869 /* Step 6: Loop through rows of the RHS. Compare each row to the LHS.
003870 ** If any comparison is NULL, then the result is NULL. If all
003871 ** comparisons are FALSE then the final result is FALSE.
003872 **
003873 ** For a scalar LHS, it is sufficient to check just the first row
003874 ** of the RHS.
003875 */
003876 if( destStep6 ) sqlite3VdbeResolveLabel(v, destStep6);
003877 addrTop = sqlite3VdbeAddOp2(v, OP_Rewind, iTab, destIfFalse);
003878 VdbeCoverage(v);
003879 if( nVector>1 ){
003880 destNotNull = sqlite3VdbeMakeLabel(pParse);
003881 }else{
003882 /* For nVector==1, combine steps 6 and 7 by immediately returning
003883 ** FALSE if the first comparison is not NULL */
003884 destNotNull = destIfFalse;
003885 }
003886 for(i=0; i<nVector; i++){
003887 Expr *p;
003888 CollSeq *pColl;
003889 int r3 = sqlite3GetTempReg(pParse);
003890 p = sqlite3VectorFieldSubexpr(pLeft, i);
003891 pColl = sqlite3ExprCollSeq(pParse, p);
003892 sqlite3VdbeAddOp3(v, OP_Column, iTab, i, r3);
003893 sqlite3VdbeAddOp4(v, OP_Ne, rLhs+i, destNotNull, r3,
003894 (void*)pColl, P4_COLLSEQ);
003895 VdbeCoverage(v);
003896 sqlite3ReleaseTempReg(pParse, r3);
003897 }
003898 sqlite3VdbeAddOp2(v, OP_Goto, 0, destIfNull);
003899 if( nVector>1 ){
003900 sqlite3VdbeResolveLabel(v, destNotNull);
003901 sqlite3VdbeAddOp2(v, OP_Next, iTab, addrTop+1);
003902 VdbeCoverage(v);
003903
003904 /* Step 7: If we reach this point, we know that the result must
003905 ** be false. */
003906 sqlite3VdbeAddOp2(v, OP_Goto, 0, destIfFalse);
003907 }
003908
003909 /* Jumps here in order to return true. */
003910 sqlite3VdbeJumpHere(v, addrTruthOp);
003911
003912 sqlite3ExprCodeIN_finished:
003913 if( rLhs!=rLhsOrig ) sqlite3ReleaseTempReg(pParse, rLhs);
003914 VdbeComment((v, "end IN expr"));
003915 sqlite3ExprCodeIN_oom_error:
003916 sqlite3DbFree(pParse->db, aiMap);
003917 sqlite3DbFree(pParse->db, zAff);
003918 }
003919 #endif /* SQLITE_OMIT_SUBQUERY */
003920
003921 #ifndef SQLITE_OMIT_FLOATING_POINT
003922 /*
003923 ** Generate an instruction that will put the floating point
003924 ** value described by z[0..n-1] into register iMem.
003925 **
003926 ** The z[] string will probably not be zero-terminated. But the
003927 ** z[n] character is guaranteed to be something that does not look
003928 ** like the continuation of the number.
003929 */
003930 static void codeReal(Vdbe *v, const char *z, int negateFlag, int iMem){
003931 if( ALWAYS(z!=0) ){
003932 double value;
003933 sqlite3AtoF(z, &value, sqlite3Strlen30(z), SQLITE_UTF8);
003934 assert( !sqlite3IsNaN(value) ); /* The new AtoF never returns NaN */
003935 if( negateFlag ) value = -value;
003936 sqlite3VdbeAddOp4Dup8(v, OP_Real, 0, iMem, 0, (u8*)&value, P4_REAL);
003937 }
003938 }
003939 #endif
003940
003941
003942 /*
003943 ** Generate an instruction that will put the integer describe by
003944 ** text z[0..n-1] into register iMem.
003945 **
003946 ** Expr.u.zToken is always UTF8 and zero-terminated.
003947 */
003948 static void codeInteger(Parse *pParse, Expr *pExpr, int negFlag, int iMem){
003949 Vdbe *v = pParse->pVdbe;
003950 if( pExpr->flags & EP_IntValue ){
003951 int i = pExpr->u.iValue;
003952 assert( i>=0 );
003953 if( negFlag ) i = -i;
003954 sqlite3VdbeAddOp2(v, OP_Integer, i, iMem);
003955 }else{
003956 int c;
003957 i64 value;
003958 const char *z = pExpr->u.zToken;
003959 assert( z!=0 );
003960 c = sqlite3DecOrHexToI64(z, &value);
003961 if( (c==3 && !negFlag) || (c==2) || (negFlag && value==SMALLEST_INT64)){
003962 #ifdef SQLITE_OMIT_FLOATING_POINT
003963 sqlite3ErrorMsg(pParse, "oversized integer: %s%#T", negFlag?"-":"",pExpr);
003964 #else
003965 #ifndef SQLITE_OMIT_HEX_INTEGER
003966 if( sqlite3_strnicmp(z,"0x",2)==0 ){
003967 sqlite3ErrorMsg(pParse, "hex literal too big: %s%#T",
003968 negFlag?"-":"",pExpr);
003969 }else
003970 #endif
003971 {
003972 codeReal(v, z, negFlag, iMem);
003973 }
003974 #endif
003975 }else{
003976 if( negFlag ){ value = c==3 ? SMALLEST_INT64 : -value; }
003977 sqlite3VdbeAddOp4Dup8(v, OP_Int64, 0, iMem, 0, (u8*)&value, P4_INT64);
003978 }
003979 }
003980 }
003981
003982
003983 /* Generate code that will load into register regOut a value that is
003984 ** appropriate for the iIdxCol-th column of index pIdx.
003985 */
003986 void sqlite3ExprCodeLoadIndexColumn(
003987 Parse *pParse, /* The parsing context */
003988 Index *pIdx, /* The index whose column is to be loaded */
003989 int iTabCur, /* Cursor pointing to a table row */
003990 int iIdxCol, /* The column of the index to be loaded */
003991 int regOut /* Store the index column value in this register */
003992 ){
003993 i16 iTabCol = pIdx->aiColumn[iIdxCol];
003994 if( iTabCol==XN_EXPR ){
003995 assert( pIdx->aColExpr );
003996 assert( pIdx->aColExpr->nExpr>iIdxCol );
003997 pParse->iSelfTab = iTabCur + 1;
003998 sqlite3ExprCodeCopy(pParse, pIdx->aColExpr->a[iIdxCol].pExpr, regOut);
003999 pParse->iSelfTab = 0;
004000 }else{
004001 sqlite3ExprCodeGetColumnOfTable(pParse->pVdbe, pIdx->pTable, iTabCur,
004002 iTabCol, regOut);
004003 }
004004 }
004005
004006 #ifndef SQLITE_OMIT_GENERATED_COLUMNS
004007 /*
004008 ** Generate code that will compute the value of generated column pCol
004009 ** and store the result in register regOut
004010 */
004011 void sqlite3ExprCodeGeneratedColumn(
004012 Parse *pParse, /* Parsing context */
004013 Table *pTab, /* Table containing the generated column */
004014 Column *pCol, /* The generated column */
004015 int regOut /* Put the result in this register */
004016 ){
004017 int iAddr;
004018 Vdbe *v = pParse->pVdbe;
004019 int nErr = pParse->nErr;
004020 assert( v!=0 );
004021 assert( pParse->iSelfTab!=0 );
004022 if( pParse->iSelfTab>0 ){
004023 iAddr = sqlite3VdbeAddOp3(v, OP_IfNullRow, pParse->iSelfTab-1, 0, regOut);
004024 }else{
004025 iAddr = 0;
004026 }
004027 sqlite3ExprCodeCopy(pParse, sqlite3ColumnExpr(pTab,pCol), regOut);
004028 if( pCol->affinity>=SQLITE_AFF_TEXT ){
004029 sqlite3VdbeAddOp4(v, OP_Affinity, regOut, 1, 0, &pCol->affinity, 1);
004030 }
004031 if( iAddr ) sqlite3VdbeJumpHere(v, iAddr);
004032 if( pParse->nErr>nErr ) pParse->db->errByteOffset = -1;
004033 }
004034 #endif /* SQLITE_OMIT_GENERATED_COLUMNS */
004035
004036 /*
004037 ** Generate code to extract the value of the iCol-th column of a table.
004038 */
004039 void sqlite3ExprCodeGetColumnOfTable(
004040 Vdbe *v, /* Parsing context */
004041 Table *pTab, /* The table containing the value */
004042 int iTabCur, /* The table cursor. Or the PK cursor for WITHOUT ROWID */
004043 int iCol, /* Index of the column to extract */
004044 int regOut /* Extract the value into this register */
004045 ){
004046 Column *pCol;
004047 assert( v!=0 );
004048 assert( pTab!=0 );
004049 assert( iCol!=XN_EXPR );
004050 if( iCol<0 || iCol==pTab->iPKey ){
004051 sqlite3VdbeAddOp2(v, OP_Rowid, iTabCur, regOut);
004052 VdbeComment((v, "%s.rowid", pTab->zName));
004053 }else{
004054 int op;
004055 int x;
004056 if( IsVirtual(pTab) ){
004057 op = OP_VColumn;
004058 x = iCol;
004059 #ifndef SQLITE_OMIT_GENERATED_COLUMNS
004060 }else if( (pCol = &pTab->aCol[iCol])->colFlags & COLFLAG_VIRTUAL ){
004061 Parse *pParse = sqlite3VdbeParser(v);
004062 if( pCol->colFlags & COLFLAG_BUSY ){
004063 sqlite3ErrorMsg(pParse, "generated column loop on \"%s\"",
004064 pCol->zCnName);
004065 }else{
004066 int savedSelfTab = pParse->iSelfTab;
004067 pCol->colFlags |= COLFLAG_BUSY;
004068 pParse->iSelfTab = iTabCur+1;
004069 sqlite3ExprCodeGeneratedColumn(pParse, pTab, pCol, regOut);
004070 pParse->iSelfTab = savedSelfTab;
004071 pCol->colFlags &= ~COLFLAG_BUSY;
004072 }
004073 return;
004074 #endif
004075 }else if( !HasRowid(pTab) ){
004076 testcase( iCol!=sqlite3TableColumnToStorage(pTab, iCol) );
004077 x = sqlite3TableColumnToIndex(sqlite3PrimaryKeyIndex(pTab), iCol);
004078 op = OP_Column;
004079 }else{
004080 x = sqlite3TableColumnToStorage(pTab,iCol);
004081 testcase( x!=iCol );
004082 op = OP_Column;
004083 }
004084 sqlite3VdbeAddOp3(v, op, iTabCur, x, regOut);
004085 sqlite3ColumnDefault(v, pTab, iCol, regOut);
004086 }
004087 }
004088
004089 /*
004090 ** Generate code that will extract the iColumn-th column from
004091 ** table pTab and store the column value in register iReg.
004092 **
004093 ** There must be an open cursor to pTab in iTable when this routine
004094 ** is called. If iColumn<0 then code is generated that extracts the rowid.
004095 */
004096 int sqlite3ExprCodeGetColumn(
004097 Parse *pParse, /* Parsing and code generating context */
004098 Table *pTab, /* Description of the table we are reading from */
004099 int iColumn, /* Index of the table column */
004100 int iTable, /* The cursor pointing to the table */
004101 int iReg, /* Store results here */
004102 u8 p5 /* P5 value for OP_Column + FLAGS */
004103 ){
004104 assert( pParse->pVdbe!=0 );
004105 assert( (p5 & (OPFLAG_NOCHNG|OPFLAG_TYPEOFARG|OPFLAG_LENGTHARG))==p5 );
004106 assert( IsVirtual(pTab) || (p5 & OPFLAG_NOCHNG)==0 );
004107 sqlite3ExprCodeGetColumnOfTable(pParse->pVdbe, pTab, iTable, iColumn, iReg);
004108 if( p5 ){
004109 VdbeOp *pOp = sqlite3VdbeGetLastOp(pParse->pVdbe);
004110 if( pOp->opcode==OP_Column ) pOp->p5 = p5;
004111 if( pOp->opcode==OP_VColumn ) pOp->p5 = (p5 & OPFLAG_NOCHNG);
004112 }
004113 return iReg;
004114 }
004115
004116 /*
004117 ** Generate code to move content from registers iFrom...iFrom+nReg-1
004118 ** over to iTo..iTo+nReg-1.
004119 */
004120 void sqlite3ExprCodeMove(Parse *pParse, int iFrom, int iTo, int nReg){
004121 sqlite3VdbeAddOp3(pParse->pVdbe, OP_Move, iFrom, iTo, nReg);
004122 }
004123
004124 /*
004125 ** Convert a scalar expression node to a TK_REGISTER referencing
004126 ** register iReg. The caller must ensure that iReg already contains
004127 ** the correct value for the expression.
004128 */
004129 static void exprToRegister(Expr *pExpr, int iReg){
004130 Expr *p = sqlite3ExprSkipCollateAndLikely(pExpr);
004131 if( NEVER(p==0) ) return;
004132 p->op2 = p->op;
004133 p->op = TK_REGISTER;
004134 p->iTable = iReg;
004135 ExprClearProperty(p, EP_Skip);
004136 }
004137
004138 /*
004139 ** Evaluate an expression (either a vector or a scalar expression) and store
004140 ** the result in contiguous temporary registers. Return the index of
004141 ** the first register used to store the result.
004142 **
004143 ** If the returned result register is a temporary scalar, then also write
004144 ** that register number into *piFreeable. If the returned result register
004145 ** is not a temporary or if the expression is a vector set *piFreeable
004146 ** to 0.
004147 */
004148 static int exprCodeVector(Parse *pParse, Expr *p, int *piFreeable){
004149 int iResult;
004150 int nResult = sqlite3ExprVectorSize(p);
004151 if( nResult==1 ){
004152 iResult = sqlite3ExprCodeTemp(pParse, p, piFreeable);
004153 }else{
004154 *piFreeable = 0;
004155 if( p->op==TK_SELECT ){
004156 #if SQLITE_OMIT_SUBQUERY
004157 iResult = 0;
004158 #else
004159 iResult = sqlite3CodeSubselect(pParse, p);
004160 #endif
004161 }else{
004162 int i;
004163 iResult = pParse->nMem+1;
004164 pParse->nMem += nResult;
004165 assert( ExprUseXList(p) );
004166 for(i=0; i<nResult; i++){
004167 sqlite3ExprCodeFactorable(pParse, p->x.pList->a[i].pExpr, i+iResult);
004168 }
004169 }
004170 }
004171 return iResult;
004172 }
004173
004174 /*
004175 ** If the last opcode is a OP_Copy, then set the do-not-merge flag (p5)
004176 ** so that a subsequent copy will not be merged into this one.
004177 */
004178 static void setDoNotMergeFlagOnCopy(Vdbe *v){
004179 if( sqlite3VdbeGetLastOp(v)->opcode==OP_Copy ){
004180 sqlite3VdbeChangeP5(v, 1); /* Tag trailing OP_Copy as not mergeable */
004181 }
004182 }
004183
004184 /*
004185 ** Generate code to implement special SQL functions that are implemented
004186 ** in-line rather than by using the usual callbacks.
004187 */
004188 static int exprCodeInlineFunction(
004189 Parse *pParse, /* Parsing context */
004190 ExprList *pFarg, /* List of function arguments */
004191 int iFuncId, /* Function ID. One of the INTFUNC_... values */
004192 int target /* Store function result in this register */
004193 ){
004194 int nFarg;
004195 Vdbe *v = pParse->pVdbe;
004196 assert( v!=0 );
004197 assert( pFarg!=0 );
004198 nFarg = pFarg->nExpr;
004199 assert( nFarg>0 ); /* All in-line functions have at least one argument */
004200 switch( iFuncId ){
004201 case INLINEFUNC_coalesce: {
004202 /* Attempt a direct implementation of the built-in COALESCE() and
004203 ** IFNULL() functions. This avoids unnecessary evaluation of
004204 ** arguments past the first non-NULL argument.
004205 */
004206 int endCoalesce = sqlite3VdbeMakeLabel(pParse);
004207 int i;
004208 assert( nFarg>=2 );
004209 sqlite3ExprCode(pParse, pFarg->a[0].pExpr, target);
004210 for(i=1; i<nFarg; i++){
004211 sqlite3VdbeAddOp2(v, OP_NotNull, target, endCoalesce);
004212 VdbeCoverage(v);
004213 sqlite3ExprCode(pParse, pFarg->a[i].pExpr, target);
004214 }
004215 setDoNotMergeFlagOnCopy(v);
004216 sqlite3VdbeResolveLabel(v, endCoalesce);
004217 break;
004218 }
004219 case INLINEFUNC_iif: {
004220 Expr caseExpr;
004221 memset(&caseExpr, 0, sizeof(caseExpr));
004222 caseExpr.op = TK_CASE;
004223 caseExpr.x.pList = pFarg;
004224 return sqlite3ExprCodeTarget(pParse, &caseExpr, target);
004225 }
004226 #ifdef SQLITE_ENABLE_OFFSET_SQL_FUNC
004227 case INLINEFUNC_sqlite_offset: {
004228 Expr *pArg = pFarg->a[0].pExpr;
004229 if( pArg->op==TK_COLUMN && pArg->iTable>=0 ){
004230 sqlite3VdbeAddOp3(v, OP_Offset, pArg->iTable, pArg->iColumn, target);
004231 }else{
004232 sqlite3VdbeAddOp2(v, OP_Null, 0, target);
004233 }
004234 break;
004235 }
004236 #endif
004237 default: {
004238 /* The UNLIKELY() function is a no-op. The result is the value
004239 ** of the first argument.
004240 */
004241 assert( nFarg==1 || nFarg==2 );
004242 target = sqlite3ExprCodeTarget(pParse, pFarg->a[0].pExpr, target);
004243 break;
004244 }
004245
004246 /***********************************************************************
004247 ** Test-only SQL functions that are only usable if enabled
004248 ** via SQLITE_TESTCTRL_INTERNAL_FUNCTIONS
004249 */
004250 #if !defined(SQLITE_UNTESTABLE)
004251 case INLINEFUNC_expr_compare: {
004252 /* Compare two expressions using sqlite3ExprCompare() */
004253 assert( nFarg==2 );
004254 sqlite3VdbeAddOp2(v, OP_Integer,
004255 sqlite3ExprCompare(0,pFarg->a[0].pExpr, pFarg->a[1].pExpr,-1),
004256 target);
004257 break;
004258 }
004259
004260 case INLINEFUNC_expr_implies_expr: {
004261 /* Compare two expressions using sqlite3ExprImpliesExpr() */
004262 assert( nFarg==2 );
004263 sqlite3VdbeAddOp2(v, OP_Integer,
004264 sqlite3ExprImpliesExpr(pParse,pFarg->a[0].pExpr, pFarg->a[1].pExpr,-1),
004265 target);
004266 break;
004267 }
004268
004269 case INLINEFUNC_implies_nonnull_row: {
004270 /* Result of sqlite3ExprImpliesNonNullRow() */
004271 Expr *pA1;
004272 assert( nFarg==2 );
004273 pA1 = pFarg->a[1].pExpr;
004274 if( pA1->op==TK_COLUMN ){
004275 sqlite3VdbeAddOp2(v, OP_Integer,
004276 sqlite3ExprImpliesNonNullRow(pFarg->a[0].pExpr,pA1->iTable,1),
004277 target);
004278 }else{
004279 sqlite3VdbeAddOp2(v, OP_Null, 0, target);
004280 }
004281 break;
004282 }
004283
004284 case INLINEFUNC_affinity: {
004285 /* The AFFINITY() function evaluates to a string that describes
004286 ** the type affinity of the argument. This is used for testing of
004287 ** the SQLite type logic.
004288 */
004289 const char *azAff[] = { "blob", "text", "numeric", "integer",
004290 "real", "flexnum" };
004291 char aff;
004292 assert( nFarg==1 );
004293 aff = sqlite3ExprAffinity(pFarg->a[0].pExpr);
004294 assert( aff<=SQLITE_AFF_NONE
004295 || (aff>=SQLITE_AFF_BLOB && aff<=SQLITE_AFF_FLEXNUM) );
004296 sqlite3VdbeLoadString(v, target,
004297 (aff<=SQLITE_AFF_NONE) ? "none" : azAff[aff-SQLITE_AFF_BLOB]);
004298 break;
004299 }
004300 #endif /* !defined(SQLITE_UNTESTABLE) */
004301 }
004302 return target;
004303 }
004304
004305 /*
004306 ** Check to see if pExpr is one of the indexed expressions on pParse->pIdxEpr.
004307 ** If it is, then resolve the expression by reading from the index and
004308 ** return the register into which the value has been read. If pExpr is
004309 ** not an indexed expression, then return negative.
004310 */
004311 static SQLITE_NOINLINE int sqlite3IndexedExprLookup(
004312 Parse *pParse, /* The parsing context */
004313 Expr *pExpr, /* The expression to potentially bypass */
004314 int target /* Where to store the result of the expression */
004315 ){
004316 IndexedExpr *p;
004317 Vdbe *v;
004318 for(p=pParse->pIdxEpr; p; p=p->pIENext){
004319 u8 exprAff;
004320 int iDataCur = p->iDataCur;
004321 if( iDataCur<0 ) continue;
004322 if( pParse->iSelfTab ){
004323 if( p->iDataCur!=pParse->iSelfTab-1 ) continue;
004324 iDataCur = -1;
004325 }
004326 if( sqlite3ExprCompare(0, pExpr, p->pExpr, iDataCur)!=0 ) continue;
004327 assert( p->aff>=SQLITE_AFF_BLOB && p->aff<=SQLITE_AFF_NUMERIC );
004328 exprAff = sqlite3ExprAffinity(pExpr);
004329 if( (exprAff<=SQLITE_AFF_BLOB && p->aff!=SQLITE_AFF_BLOB)
004330 || (exprAff==SQLITE_AFF_TEXT && p->aff!=SQLITE_AFF_TEXT)
004331 || (exprAff>=SQLITE_AFF_NUMERIC && p->aff!=SQLITE_AFF_NUMERIC)
004332 ){
004333 /* Affinity mismatch on a generated column */
004334 continue;
004335 }
004336
004337 v = pParse->pVdbe;
004338 assert( v!=0 );
004339 if( p->bMaybeNullRow ){
004340 /* If the index is on a NULL row due to an outer join, then we
004341 ** cannot extract the value from the index. The value must be
004342 ** computed using the original expression. */
004343 int addr = sqlite3VdbeCurrentAddr(v);
004344 sqlite3VdbeAddOp3(v, OP_IfNullRow, p->iIdxCur, addr+3, target);
004345 VdbeCoverage(v);
004346 sqlite3VdbeAddOp3(v, OP_Column, p->iIdxCur, p->iIdxCol, target);
004347 VdbeComment((v, "%s expr-column %d", p->zIdxName, p->iIdxCol));
004348 sqlite3VdbeGoto(v, 0);
004349 p = pParse->pIdxEpr;
004350 pParse->pIdxEpr = 0;
004351 sqlite3ExprCode(pParse, pExpr, target);
004352 pParse->pIdxEpr = p;
004353 sqlite3VdbeJumpHere(v, addr+2);
004354 }else{
004355 sqlite3VdbeAddOp3(v, OP_Column, p->iIdxCur, p->iIdxCol, target);
004356 VdbeComment((v, "%s expr-column %d", p->zIdxName, p->iIdxCol));
004357 }
004358 return target;
004359 }
004360 return -1; /* Not found */
004361 }
004362
004363
004364 /*
004365 ** Expresion pExpr is guaranteed to be a TK_COLUMN or equivalent. This
004366 ** function checks the Parse.pIdxPartExpr list to see if this column
004367 ** can be replaced with a constant value. If so, it generates code to
004368 ** put the constant value in a register (ideally, but not necessarily,
004369 ** register iTarget) and returns the register number.
004370 **
004371 ** Or, if the TK_COLUMN cannot be replaced by a constant, zero is
004372 ** returned.
004373 */
004374 static int exprPartidxExprLookup(Parse *pParse, Expr *pExpr, int iTarget){
004375 IndexedExpr *p;
004376 for(p=pParse->pIdxPartExpr; p; p=p->pIENext){
004377 if( pExpr->iColumn==p->iIdxCol && pExpr->iTable==p->iDataCur ){
004378 Vdbe *v = pParse->pVdbe;
004379 int addr = 0;
004380 int ret;
004381
004382 if( p->bMaybeNullRow ){
004383 addr = sqlite3VdbeAddOp1(v, OP_IfNullRow, p->iIdxCur);
004384 }
004385 ret = sqlite3ExprCodeTarget(pParse, p->pExpr, iTarget);
004386 sqlite3VdbeAddOp4(pParse->pVdbe, OP_Affinity, ret, 1, 0,
004387 (const char*)&p->aff, 1);
004388 if( addr ){
004389 sqlite3VdbeJumpHere(v, addr);
004390 sqlite3VdbeChangeP3(v, addr, ret);
004391 }
004392 return ret;
004393 }
004394 }
004395 return 0;
004396 }
004397
004398
004399 /*
004400 ** Generate code into the current Vdbe to evaluate the given
004401 ** expression. Attempt to store the results in register "target".
004402 ** Return the register where results are stored.
004403 **
004404 ** With this routine, there is no guarantee that results will
004405 ** be stored in target. The result might be stored in some other
004406 ** register if it is convenient to do so. The calling function
004407 ** must check the return code and move the results to the desired
004408 ** register.
004409 */
004410 int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target){
004411 Vdbe *v = pParse->pVdbe; /* The VM under construction */
004412 int op; /* The opcode being coded */
004413 int inReg = target; /* Results stored in register inReg */
004414 int regFree1 = 0; /* If non-zero free this temporary register */
004415 int regFree2 = 0; /* If non-zero free this temporary register */
004416 int r1, r2; /* Various register numbers */
004417 Expr tempX; /* Temporary expression node */
004418 int p5 = 0;
004419
004420 assert( target>0 && target<=pParse->nMem );
004421 assert( v!=0 );
004422
004423 expr_code_doover:
004424 if( pExpr==0 ){
004425 op = TK_NULL;
004426 }else if( pParse->pIdxEpr!=0
004427 && !ExprHasProperty(pExpr, EP_Leaf)
004428 && (r1 = sqlite3IndexedExprLookup(pParse, pExpr, target))>=0
004429 ){
004430 return r1;
004431 }else{
004432 assert( !ExprHasVVAProperty(pExpr,EP_Immutable) );
004433 op = pExpr->op;
004434 }
004435 assert( op!=TK_ORDER );
004436 switch( op ){
004437 case TK_AGG_COLUMN: {
004438 AggInfo *pAggInfo = pExpr->pAggInfo;
004439 struct AggInfo_col *pCol;
004440 assert( pAggInfo!=0 );
004441 assert( pExpr->iAgg>=0 );
004442 if( pExpr->iAgg>=pAggInfo->nColumn ){
004443 /* Happens when the left table of a RIGHT JOIN is null and
004444 ** is using an expression index */
004445 sqlite3VdbeAddOp2(v, OP_Null, 0, target);
004446 #ifdef SQLITE_VDBE_COVERAGE
004447 /* Verify that the OP_Null above is exercised by tests
004448 ** tag-20230325-2 */
004449 sqlite3VdbeAddOp3(v, OP_NotNull, target, 1, 20230325);
004450 VdbeCoverageNeverTaken(v);
004451 #endif
004452 break;
004453 }
004454 pCol = &pAggInfo->aCol[pExpr->iAgg];
004455 if( !pAggInfo->directMode ){
004456 return AggInfoColumnReg(pAggInfo, pExpr->iAgg);
004457 }else if( pAggInfo->useSortingIdx ){
004458 Table *pTab = pCol->pTab;
004459 sqlite3VdbeAddOp3(v, OP_Column, pAggInfo->sortingIdxPTab,
004460 pCol->iSorterColumn, target);
004461 if( pTab==0 ){
004462 /* No comment added */
004463 }else if( pCol->iColumn<0 ){
004464 VdbeComment((v,"%s.rowid",pTab->zName));
004465 }else{
004466 VdbeComment((v,"%s.%s",
004467 pTab->zName, pTab->aCol[pCol->iColumn].zCnName));
004468 if( pTab->aCol[pCol->iColumn].affinity==SQLITE_AFF_REAL ){
004469 sqlite3VdbeAddOp1(v, OP_RealAffinity, target);
004470 }
004471 }
004472 return target;
004473 }else if( pExpr->y.pTab==0 ){
004474 /* This case happens when the argument to an aggregate function
004475 ** is rewritten by aggregateConvertIndexedExprRefToColumn() */
004476 sqlite3VdbeAddOp3(v, OP_Column, pExpr->iTable, pExpr->iColumn, target);
004477 return target;
004478 }
004479 /* Otherwise, fall thru into the TK_COLUMN case */
004480 /* no break */ deliberate_fall_through
004481 }
004482 case TK_COLUMN: {
004483 int iTab = pExpr->iTable;
004484 int iReg;
004485 if( ExprHasProperty(pExpr, EP_FixedCol) ){
004486 /* This COLUMN expression is really a constant due to WHERE clause
004487 ** constraints, and that constant is coded by the pExpr->pLeft
004488 ** expression. However, make sure the constant has the correct
004489 ** datatype by applying the Affinity of the table column to the
004490 ** constant.
004491 */
004492 int aff;
004493 iReg = sqlite3ExprCodeTarget(pParse, pExpr->pLeft,target);
004494 assert( ExprUseYTab(pExpr) );
004495 assert( pExpr->y.pTab!=0 );
004496 aff = sqlite3TableColumnAffinity(pExpr->y.pTab, pExpr->iColumn);
004497 if( aff>SQLITE_AFF_BLOB ){
004498 static const char zAff[] = "B\000C\000D\000E\000F";
004499 assert( SQLITE_AFF_BLOB=='A' );
004500 assert( SQLITE_AFF_TEXT=='B' );
004501 sqlite3VdbeAddOp4(v, OP_Affinity, iReg, 1, 0,
004502 &zAff[(aff-'B')*2], P4_STATIC);
004503 }
004504 return iReg;
004505 }
004506 if( iTab<0 ){
004507 if( pParse->iSelfTab<0 ){
004508 /* Other columns in the same row for CHECK constraints or
004509 ** generated columns or for inserting into partial index.
004510 ** The row is unpacked into registers beginning at
004511 ** 0-(pParse->iSelfTab). The rowid (if any) is in a register
004512 ** immediately prior to the first column.
004513 */
004514 Column *pCol;
004515 Table *pTab;
004516 int iSrc;
004517 int iCol = pExpr->iColumn;
004518 assert( ExprUseYTab(pExpr) );
004519 pTab = pExpr->y.pTab;
004520 assert( pTab!=0 );
004521 assert( iCol>=XN_ROWID );
004522 assert( iCol<pTab->nCol );
004523 if( iCol<0 ){
004524 return -1-pParse->iSelfTab;
004525 }
004526 pCol = pTab->aCol + iCol;
004527 testcase( iCol!=sqlite3TableColumnToStorage(pTab,iCol) );
004528 iSrc = sqlite3TableColumnToStorage(pTab, iCol) - pParse->iSelfTab;
004529 #ifndef SQLITE_OMIT_GENERATED_COLUMNS
004530 if( pCol->colFlags & COLFLAG_GENERATED ){
004531 if( pCol->colFlags & COLFLAG_BUSY ){
004532 sqlite3ErrorMsg(pParse, "generated column loop on \"%s\"",
004533 pCol->zCnName);
004534 return 0;
004535 }
004536 pCol->colFlags |= COLFLAG_BUSY;
004537 if( pCol->colFlags & COLFLAG_NOTAVAIL ){
004538 sqlite3ExprCodeGeneratedColumn(pParse, pTab, pCol, iSrc);
004539 }
004540 pCol->colFlags &= ~(COLFLAG_BUSY|COLFLAG_NOTAVAIL);
004541 return iSrc;
004542 }else
004543 #endif /* SQLITE_OMIT_GENERATED_COLUMNS */
004544 if( pCol->affinity==SQLITE_AFF_REAL ){
004545 sqlite3VdbeAddOp2(v, OP_SCopy, iSrc, target);
004546 sqlite3VdbeAddOp1(v, OP_RealAffinity, target);
004547 return target;
004548 }else{
004549 return iSrc;
004550 }
004551 }else{
004552 /* Coding an expression that is part of an index where column names
004553 ** in the index refer to the table to which the index belongs */
004554 iTab = pParse->iSelfTab - 1;
004555 }
004556 }
004557 else if( pParse->pIdxPartExpr
004558 && 0!=(r1 = exprPartidxExprLookup(pParse, pExpr, target))
004559 ){
004560 return r1;
004561 }
004562 assert( ExprUseYTab(pExpr) );
004563 assert( pExpr->y.pTab!=0 );
004564 iReg = sqlite3ExprCodeGetColumn(pParse, pExpr->y.pTab,
004565 pExpr->iColumn, iTab, target,
004566 pExpr->op2);
004567 return iReg;
004568 }
004569 case TK_INTEGER: {
004570 codeInteger(pParse, pExpr, 0, target);
004571 return target;
004572 }
004573 case TK_TRUEFALSE: {
004574 sqlite3VdbeAddOp2(v, OP_Integer, sqlite3ExprTruthValue(pExpr), target);
004575 return target;
004576 }
004577 #ifndef SQLITE_OMIT_FLOATING_POINT
004578 case TK_FLOAT: {
004579 assert( !ExprHasProperty(pExpr, EP_IntValue) );
004580 codeReal(v, pExpr->u.zToken, 0, target);
004581 return target;
004582 }
004583 #endif
004584 case TK_STRING: {
004585 assert( !ExprHasProperty(pExpr, EP_IntValue) );
004586 sqlite3VdbeLoadString(v, target, pExpr->u.zToken);
004587 return target;
004588 }
004589 default: {
004590 /* Make NULL the default case so that if a bug causes an illegal
004591 ** Expr node to be passed into this function, it will be handled
004592 ** sanely and not crash. But keep the assert() to bring the problem
004593 ** to the attention of the developers. */
004594 assert( op==TK_NULL || op==TK_ERROR || pParse->db->mallocFailed );
004595 sqlite3VdbeAddOp2(v, OP_Null, 0, target);
004596 return target;
004597 }
004598 #ifndef SQLITE_OMIT_BLOB_LITERAL
004599 case TK_BLOB: {
004600 int n;
004601 const char *z;
004602 char *zBlob;
004603 assert( !ExprHasProperty(pExpr, EP_IntValue) );
004604 assert( pExpr->u.zToken[0]=='x' || pExpr->u.zToken[0]=='X' );
004605 assert( pExpr->u.zToken[1]=='\'' );
004606 z = &pExpr->u.zToken[2];
004607 n = sqlite3Strlen30(z) - 1;
004608 assert( z[n]=='\'' );
004609 zBlob = sqlite3HexToBlob(sqlite3VdbeDb(v), z, n);
004610 sqlite3VdbeAddOp4(v, OP_Blob, n/2, target, 0, zBlob, P4_DYNAMIC);
004611 return target;
004612 }
004613 #endif
004614 case TK_VARIABLE: {
004615 assert( !ExprHasProperty(pExpr, EP_IntValue) );
004616 assert( pExpr->u.zToken!=0 );
004617 assert( pExpr->u.zToken[0]!=0 );
004618 sqlite3VdbeAddOp2(v, OP_Variable, pExpr->iColumn, target);
004619 if( pExpr->u.zToken[1]!=0 ){
004620 const char *z = sqlite3VListNumToName(pParse->pVList, pExpr->iColumn);
004621 assert( pExpr->u.zToken[0]=='?' || (z && !strcmp(pExpr->u.zToken, z)) );
004622 pParse->pVList[0] = 0; /* Indicate VList may no longer be enlarged */
004623 sqlite3VdbeAppendP4(v, (char*)z, P4_STATIC);
004624 }
004625 return target;
004626 }
004627 case TK_REGISTER: {
004628 return pExpr->iTable;
004629 }
004630 #ifndef SQLITE_OMIT_CAST
004631 case TK_CAST: {
004632 /* Expressions of the form: CAST(pLeft AS token) */
004633 sqlite3ExprCode(pParse, pExpr->pLeft, target);
004634 assert( inReg==target );
004635 assert( !ExprHasProperty(pExpr, EP_IntValue) );
004636 sqlite3VdbeAddOp2(v, OP_Cast, target,
004637 sqlite3AffinityType(pExpr->u.zToken, 0));
004638 return inReg;
004639 }
004640 #endif /* SQLITE_OMIT_CAST */
004641 case TK_IS:
004642 case TK_ISNOT:
004643 op = (op==TK_IS) ? TK_EQ : TK_NE;
004644 p5 = SQLITE_NULLEQ;
004645 /* fall-through */
004646 case TK_LT:
004647 case TK_LE:
004648 case TK_GT:
004649 case TK_GE:
004650 case TK_NE:
004651 case TK_EQ: {
004652 Expr *pLeft = pExpr->pLeft;
004653 if( sqlite3ExprIsVector(pLeft) ){
004654 codeVectorCompare(pParse, pExpr, target, op, p5);
004655 }else{
004656 r1 = sqlite3ExprCodeTemp(pParse, pLeft, ®Free1);
004657 r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, ®Free2);
004658 sqlite3VdbeAddOp2(v, OP_Integer, 1, inReg);
004659 codeCompare(pParse, pLeft, pExpr->pRight, op, r1, r2,
004660 sqlite3VdbeCurrentAddr(v)+2, p5,
004661 ExprHasProperty(pExpr,EP_Commuted));
004662 assert(TK_LT==OP_Lt); testcase(op==OP_Lt); VdbeCoverageIf(v,op==OP_Lt);
004663 assert(TK_LE==OP_Le); testcase(op==OP_Le); VdbeCoverageIf(v,op==OP_Le);
004664 assert(TK_GT==OP_Gt); testcase(op==OP_Gt); VdbeCoverageIf(v,op==OP_Gt);
004665 assert(TK_GE==OP_Ge); testcase(op==OP_Ge); VdbeCoverageIf(v,op==OP_Ge);
004666 assert(TK_EQ==OP_Eq); testcase(op==OP_Eq); VdbeCoverageIf(v,op==OP_Eq);
004667 assert(TK_NE==OP_Ne); testcase(op==OP_Ne); VdbeCoverageIf(v,op==OP_Ne);
004668 if( p5==SQLITE_NULLEQ ){
004669 sqlite3VdbeAddOp2(v, OP_Integer, 0, inReg);
004670 }else{
004671 sqlite3VdbeAddOp3(v, OP_ZeroOrNull, r1, inReg, r2);
004672 }
004673 testcase( regFree1==0 );
004674 testcase( regFree2==0 );
004675 }
004676 break;
004677 }
004678 case TK_AND:
004679 case TK_OR:
004680 case TK_PLUS:
004681 case TK_STAR:
004682 case TK_MINUS:
004683 case TK_REM:
004684 case TK_BITAND:
004685 case TK_BITOR:
004686 case TK_SLASH:
004687 case TK_LSHIFT:
004688 case TK_RSHIFT:
004689 case TK_CONCAT: {
004690 assert( TK_AND==OP_And ); testcase( op==TK_AND );
004691 assert( TK_OR==OP_Or ); testcase( op==TK_OR );
004692 assert( TK_PLUS==OP_Add ); testcase( op==TK_PLUS );
004693 assert( TK_MINUS==OP_Subtract ); testcase( op==TK_MINUS );
004694 assert( TK_REM==OP_Remainder ); testcase( op==TK_REM );
004695 assert( TK_BITAND==OP_BitAnd ); testcase( op==TK_BITAND );
004696 assert( TK_BITOR==OP_BitOr ); testcase( op==TK_BITOR );
004697 assert( TK_SLASH==OP_Divide ); testcase( op==TK_SLASH );
004698 assert( TK_LSHIFT==OP_ShiftLeft ); testcase( op==TK_LSHIFT );
004699 assert( TK_RSHIFT==OP_ShiftRight ); testcase( op==TK_RSHIFT );
004700 assert( TK_CONCAT==OP_Concat ); testcase( op==TK_CONCAT );
004701 r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free1);
004702 r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, ®Free2);
004703 sqlite3VdbeAddOp3(v, op, r2, r1, target);
004704 testcase( regFree1==0 );
004705 testcase( regFree2==0 );
004706 break;
004707 }
004708 case TK_UMINUS: {
004709 Expr *pLeft = pExpr->pLeft;
004710 assert( pLeft );
004711 if( pLeft->op==TK_INTEGER ){
004712 codeInteger(pParse, pLeft, 1, target);
004713 return target;
004714 #ifndef SQLITE_OMIT_FLOATING_POINT
004715 }else if( pLeft->op==TK_FLOAT ){
004716 assert( !ExprHasProperty(pExpr, EP_IntValue) );
004717 codeReal(v, pLeft->u.zToken, 1, target);
004718 return target;
004719 #endif
004720 }else{
004721 tempX.op = TK_INTEGER;
004722 tempX.flags = EP_IntValue|EP_TokenOnly;
004723 tempX.u.iValue = 0;
004724 ExprClearVVAProperties(&tempX);
004725 r1 = sqlite3ExprCodeTemp(pParse, &tempX, ®Free1);
004726 r2 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free2);
004727 sqlite3VdbeAddOp3(v, OP_Subtract, r2, r1, target);
004728 testcase( regFree2==0 );
004729 }
004730 break;
004731 }
004732 case TK_BITNOT:
004733 case TK_NOT: {
004734 assert( TK_BITNOT==OP_BitNot ); testcase( op==TK_BITNOT );
004735 assert( TK_NOT==OP_Not ); testcase( op==TK_NOT );
004736 r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free1);
004737 testcase( regFree1==0 );
004738 sqlite3VdbeAddOp2(v, op, r1, inReg);
004739 break;
004740 }
004741 case TK_TRUTH: {
004742 int isTrue; /* IS TRUE or IS NOT TRUE */
004743 int bNormal; /* IS TRUE or IS FALSE */
004744 r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free1);
004745 testcase( regFree1==0 );
004746 isTrue = sqlite3ExprTruthValue(pExpr->pRight);
004747 bNormal = pExpr->op2==TK_IS;
004748 testcase( isTrue && bNormal);
004749 testcase( !isTrue && bNormal);
004750 sqlite3VdbeAddOp4Int(v, OP_IsTrue, r1, inReg, !isTrue, isTrue ^ bNormal);
004751 break;
004752 }
004753 case TK_ISNULL:
004754 case TK_NOTNULL: {
004755 int addr;
004756 assert( TK_ISNULL==OP_IsNull ); testcase( op==TK_ISNULL );
004757 assert( TK_NOTNULL==OP_NotNull ); testcase( op==TK_NOTNULL );
004758 sqlite3VdbeAddOp2(v, OP_Integer, 1, target);
004759 r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free1);
004760 testcase( regFree1==0 );
004761 addr = sqlite3VdbeAddOp1(v, op, r1);
004762 VdbeCoverageIf(v, op==TK_ISNULL);
004763 VdbeCoverageIf(v, op==TK_NOTNULL);
004764 sqlite3VdbeAddOp2(v, OP_Integer, 0, target);
004765 sqlite3VdbeJumpHere(v, addr);
004766 break;
004767 }
004768 case TK_AGG_FUNCTION: {
004769 AggInfo *pInfo = pExpr->pAggInfo;
004770 if( pInfo==0
004771 || NEVER(pExpr->iAgg<0)
004772 || NEVER(pExpr->iAgg>=pInfo->nFunc)
004773 ){
004774 assert( !ExprHasProperty(pExpr, EP_IntValue) );
004775 sqlite3ErrorMsg(pParse, "misuse of aggregate: %#T()", pExpr);
004776 }else{
004777 return AggInfoFuncReg(pInfo, pExpr->iAgg);
004778 }
004779 break;
004780 }
004781 case TK_FUNCTION: {
004782 ExprList *pFarg; /* List of function arguments */
004783 int nFarg; /* Number of function arguments */
004784 FuncDef *pDef; /* The function definition object */
004785 const char *zId; /* The function name */
004786 u32 constMask = 0; /* Mask of function arguments that are constant */
004787 int i; /* Loop counter */
004788 sqlite3 *db = pParse->db; /* The database connection */
004789 u8 enc = ENC(db); /* The text encoding used by this database */
004790 CollSeq *pColl = 0; /* A collating sequence */
004791
004792 #ifndef SQLITE_OMIT_WINDOWFUNC
004793 if( ExprHasProperty(pExpr, EP_WinFunc) ){
004794 return pExpr->y.pWin->regResult;
004795 }
004796 #endif
004797
004798 if( ConstFactorOk(pParse) && sqlite3ExprIsConstantNotJoin(pExpr) ){
004799 /* SQL functions can be expensive. So try to avoid running them
004800 ** multiple times if we know they always give the same result */
004801 return sqlite3ExprCodeRunJustOnce(pParse, pExpr, -1);
004802 }
004803 assert( !ExprHasProperty(pExpr, EP_TokenOnly) );
004804 assert( ExprUseXList(pExpr) );
004805 pFarg = pExpr->x.pList;
004806 nFarg = pFarg ? pFarg->nExpr : 0;
004807 assert( !ExprHasProperty(pExpr, EP_IntValue) );
004808 zId = pExpr->u.zToken;
004809 pDef = sqlite3FindFunction(db, zId, nFarg, enc, 0);
004810 #ifdef SQLITE_ENABLE_UNKNOWN_SQL_FUNCTION
004811 if( pDef==0 && pParse->explain ){
004812 pDef = sqlite3FindFunction(db, "unknown", nFarg, enc, 0);
004813 }
004814 #endif
004815 if( pDef==0 || pDef->xFinalize!=0 ){
004816 sqlite3ErrorMsg(pParse, "unknown function: %#T()", pExpr);
004817 break;
004818 }
004819 if( (pDef->funcFlags & SQLITE_FUNC_INLINE)!=0 && ALWAYS(pFarg!=0) ){
004820 assert( (pDef->funcFlags & SQLITE_FUNC_UNSAFE)==0 );
004821 assert( (pDef->funcFlags & SQLITE_FUNC_DIRECT)==0 );
004822 return exprCodeInlineFunction(pParse, pFarg,
004823 SQLITE_PTR_TO_INT(pDef->pUserData), target);
004824 }else if( pDef->funcFlags & (SQLITE_FUNC_DIRECT|SQLITE_FUNC_UNSAFE) ){
004825 sqlite3ExprFunctionUsable(pParse, pExpr, pDef);
004826 }
004827
004828 for(i=0; i<nFarg; i++){
004829 if( i<32 && sqlite3ExprIsConstant(pFarg->a[i].pExpr) ){
004830 testcase( i==31 );
004831 constMask |= MASKBIT32(i);
004832 }
004833 if( (pDef->funcFlags & SQLITE_FUNC_NEEDCOLL)!=0 && !pColl ){
004834 pColl = sqlite3ExprCollSeq(pParse, pFarg->a[i].pExpr);
004835 }
004836 }
004837 if( pFarg ){
004838 if( constMask ){
004839 r1 = pParse->nMem+1;
004840 pParse->nMem += nFarg;
004841 }else{
004842 r1 = sqlite3GetTempRange(pParse, nFarg);
004843 }
004844
004845 /* For length() and typeof() and octet_length() functions,
004846 ** set the P5 parameter to the OP_Column opcode to OPFLAG_LENGTHARG
004847 ** or OPFLAG_TYPEOFARG or OPFLAG_BYTELENARG respectively, to avoid
004848 ** unnecessary data loading.
004849 */
004850 if( (pDef->funcFlags & (SQLITE_FUNC_LENGTH|SQLITE_FUNC_TYPEOF))!=0 ){
004851 u8 exprOp;
004852 assert( nFarg==1 );
004853 assert( pFarg->a[0].pExpr!=0 );
004854 exprOp = pFarg->a[0].pExpr->op;
004855 if( exprOp==TK_COLUMN || exprOp==TK_AGG_COLUMN ){
004856 assert( SQLITE_FUNC_LENGTH==OPFLAG_LENGTHARG );
004857 assert( SQLITE_FUNC_TYPEOF==OPFLAG_TYPEOFARG );
004858 assert( SQLITE_FUNC_BYTELEN==OPFLAG_BYTELENARG );
004859 assert( (OPFLAG_LENGTHARG|OPFLAG_TYPEOFARG)==OPFLAG_BYTELENARG );
004860 testcase( (pDef->funcFlags & OPFLAG_BYTELENARG)==OPFLAG_LENGTHARG );
004861 testcase( (pDef->funcFlags & OPFLAG_BYTELENARG)==OPFLAG_TYPEOFARG );
004862 testcase( (pDef->funcFlags & OPFLAG_BYTELENARG)==OPFLAG_BYTELENARG);
004863 pFarg->a[0].pExpr->op2 = pDef->funcFlags & OPFLAG_BYTELENARG;
004864 }
004865 }
004866
004867 sqlite3ExprCodeExprList(pParse, pFarg, r1, 0, SQLITE_ECEL_FACTOR);
004868 }else{
004869 r1 = 0;
004870 }
004871 #ifndef SQLITE_OMIT_VIRTUALTABLE
004872 /* Possibly overload the function if the first argument is
004873 ** a virtual table column.
004874 **
004875 ** For infix functions (LIKE, GLOB, REGEXP, and MATCH) use the
004876 ** second argument, not the first, as the argument to test to
004877 ** see if it is a column in a virtual table. This is done because
004878 ** the left operand of infix functions (the operand we want to
004879 ** control overloading) ends up as the second argument to the
004880 ** function. The expression "A glob B" is equivalent to
004881 ** "glob(B,A). We want to use the A in "A glob B" to test
004882 ** for function overloading. But we use the B term in "glob(B,A)".
004883 */
004884 if( nFarg>=2 && ExprHasProperty(pExpr, EP_InfixFunc) ){
004885 pDef = sqlite3VtabOverloadFunction(db, pDef, nFarg, pFarg->a[1].pExpr);
004886 }else if( nFarg>0 ){
004887 pDef = sqlite3VtabOverloadFunction(db, pDef, nFarg, pFarg->a[0].pExpr);
004888 }
004889 #endif
004890 if( pDef->funcFlags & SQLITE_FUNC_NEEDCOLL ){
004891 if( !pColl ) pColl = db->pDfltColl;
004892 sqlite3VdbeAddOp4(v, OP_CollSeq, 0, 0, 0, (char *)pColl, P4_COLLSEQ);
004893 }
004894 sqlite3VdbeAddFunctionCall(pParse, constMask, r1, target, nFarg,
004895 pDef, pExpr->op2);
004896 if( nFarg ){
004897 if( constMask==0 ){
004898 sqlite3ReleaseTempRange(pParse, r1, nFarg);
004899 }else{
004900 sqlite3VdbeReleaseRegisters(pParse, r1, nFarg, constMask, 1);
004901 }
004902 }
004903 return target;
004904 }
004905 #ifndef SQLITE_OMIT_SUBQUERY
004906 case TK_EXISTS:
004907 case TK_SELECT: {
004908 int nCol;
004909 testcase( op==TK_EXISTS );
004910 testcase( op==TK_SELECT );
004911 if( pParse->db->mallocFailed ){
004912 return 0;
004913 }else if( op==TK_SELECT
004914 && ALWAYS( ExprUseXSelect(pExpr) )
004915 && (nCol = pExpr->x.pSelect->pEList->nExpr)!=1
004916 ){
004917 sqlite3SubselectError(pParse, nCol, 1);
004918 }else{
004919 return sqlite3CodeSubselect(pParse, pExpr);
004920 }
004921 break;
004922 }
004923 case TK_SELECT_COLUMN: {
004924 int n;
004925 Expr *pLeft = pExpr->pLeft;
004926 if( pLeft->iTable==0 || pParse->withinRJSubrtn > pLeft->op2 ){
004927 pLeft->iTable = sqlite3CodeSubselect(pParse, pLeft);
004928 pLeft->op2 = pParse->withinRJSubrtn;
004929 }
004930 assert( pLeft->op==TK_SELECT || pLeft->op==TK_ERROR );
004931 n = sqlite3ExprVectorSize(pLeft);
004932 if( pExpr->iTable!=n ){
004933 sqlite3ErrorMsg(pParse, "%d columns assigned %d values",
004934 pExpr->iTable, n);
004935 }
004936 return pLeft->iTable + pExpr->iColumn;
004937 }
004938 case TK_IN: {
004939 int destIfFalse = sqlite3VdbeMakeLabel(pParse);
004940 int destIfNull = sqlite3VdbeMakeLabel(pParse);
004941 sqlite3VdbeAddOp2(v, OP_Null, 0, target);
004942 sqlite3ExprCodeIN(pParse, pExpr, destIfFalse, destIfNull);
004943 sqlite3VdbeAddOp2(v, OP_Integer, 1, target);
004944 sqlite3VdbeResolveLabel(v, destIfFalse);
004945 sqlite3VdbeAddOp2(v, OP_AddImm, target, 0);
004946 sqlite3VdbeResolveLabel(v, destIfNull);
004947 return target;
004948 }
004949 #endif /* SQLITE_OMIT_SUBQUERY */
004950
004951
004952 /*
004953 ** x BETWEEN y AND z
004954 **
004955 ** This is equivalent to
004956 **
004957 ** x>=y AND x<=z
004958 **
004959 ** X is stored in pExpr->pLeft.
004960 ** Y is stored in pExpr->pList->a[0].pExpr.
004961 ** Z is stored in pExpr->pList->a[1].pExpr.
004962 */
004963 case TK_BETWEEN: {
004964 exprCodeBetween(pParse, pExpr, target, 0, 0);
004965 return target;
004966 }
004967 case TK_COLLATE: {
004968 if( !ExprHasProperty(pExpr, EP_Collate) ){
004969 /* A TK_COLLATE Expr node without the EP_Collate tag is a so-called
004970 ** "SOFT-COLLATE" that is added to constraints that are pushed down
004971 ** from outer queries into sub-queries by the push-down optimization.
004972 ** Clear subtypes as subtypes may not cross a subquery boundary.
004973 */
004974 assert( pExpr->pLeft );
004975 sqlite3ExprCode(pParse, pExpr->pLeft, target);
004976 sqlite3VdbeAddOp1(v, OP_ClrSubtype, target);
004977 return target;
004978 }else{
004979 pExpr = pExpr->pLeft;
004980 goto expr_code_doover; /* 2018-04-28: Prevent deep recursion. */
004981 }
004982 }
004983 case TK_SPAN:
004984 case TK_UPLUS: {
004985 pExpr = pExpr->pLeft;
004986 goto expr_code_doover; /* 2018-04-28: Prevent deep recursion. OSSFuzz. */
004987 }
004988
004989 case TK_TRIGGER: {
004990 /* If the opcode is TK_TRIGGER, then the expression is a reference
004991 ** to a column in the new.* or old.* pseudo-tables available to
004992 ** trigger programs. In this case Expr.iTable is set to 1 for the
004993 ** new.* pseudo-table, or 0 for the old.* pseudo-table. Expr.iColumn
004994 ** is set to the column of the pseudo-table to read, or to -1 to
004995 ** read the rowid field.
004996 **
004997 ** The expression is implemented using an OP_Param opcode. The p1
004998 ** parameter is set to 0 for an old.rowid reference, or to (i+1)
004999 ** to reference another column of the old.* pseudo-table, where
005000 ** i is the index of the column. For a new.rowid reference, p1 is
005001 ** set to (n+1), where n is the number of columns in each pseudo-table.
005002 ** For a reference to any other column in the new.* pseudo-table, p1
005003 ** is set to (n+2+i), where n and i are as defined previously. For
005004 ** example, if the table on which triggers are being fired is
005005 ** declared as:
005006 **
005007 ** CREATE TABLE t1(a, b);
005008 **
005009 ** Then p1 is interpreted as follows:
005010 **
005011 ** p1==0 -> old.rowid p1==3 -> new.rowid
005012 ** p1==1 -> old.a p1==4 -> new.a
005013 ** p1==2 -> old.b p1==5 -> new.b
005014 */
005015 Table *pTab;
005016 int iCol;
005017 int p1;
005018
005019 assert( ExprUseYTab(pExpr) );
005020 pTab = pExpr->y.pTab;
005021 iCol = pExpr->iColumn;
005022 p1 = pExpr->iTable * (pTab->nCol+1) + 1
005023 + sqlite3TableColumnToStorage(pTab, iCol);
005024
005025 assert( pExpr->iTable==0 || pExpr->iTable==1 );
005026 assert( iCol>=-1 && iCol<pTab->nCol );
005027 assert( pTab->iPKey<0 || iCol!=pTab->iPKey );
005028 assert( p1>=0 && p1<(pTab->nCol*2+2) );
005029
005030 sqlite3VdbeAddOp2(v, OP_Param, p1, target);
005031 VdbeComment((v, "r[%d]=%s.%s", target,
005032 (pExpr->iTable ? "new" : "old"),
005033 (pExpr->iColumn<0 ? "rowid" : pExpr->y.pTab->aCol[iCol].zCnName)
005034 ));
005035
005036 #ifndef SQLITE_OMIT_FLOATING_POINT
005037 /* If the column has REAL affinity, it may currently be stored as an
005038 ** integer. Use OP_RealAffinity to make sure it is really real.
005039 **
005040 ** EVIDENCE-OF: R-60985-57662 SQLite will convert the value back to
005041 ** floating point when extracting it from the record. */
005042 if( iCol>=0 && pTab->aCol[iCol].affinity==SQLITE_AFF_REAL ){
005043 sqlite3VdbeAddOp1(v, OP_RealAffinity, target);
005044 }
005045 #endif
005046 break;
005047 }
005048
005049 case TK_VECTOR: {
005050 sqlite3ErrorMsg(pParse, "row value misused");
005051 break;
005052 }
005053
005054 /* TK_IF_NULL_ROW Expr nodes are inserted ahead of expressions
005055 ** that derive from the right-hand table of a LEFT JOIN. The
005056 ** Expr.iTable value is the table number for the right-hand table.
005057 ** The expression is only evaluated if that table is not currently
005058 ** on a LEFT JOIN NULL row.
005059 */
005060 case TK_IF_NULL_ROW: {
005061 int addrINR;
005062 u8 okConstFactor = pParse->okConstFactor;
005063 AggInfo *pAggInfo = pExpr->pAggInfo;
005064 if( pAggInfo ){
005065 assert( pExpr->iAgg>=0 && pExpr->iAgg<pAggInfo->nColumn );
005066 if( !pAggInfo->directMode ){
005067 inReg = AggInfoColumnReg(pAggInfo, pExpr->iAgg);
005068 break;
005069 }
005070 if( pExpr->pAggInfo->useSortingIdx ){
005071 sqlite3VdbeAddOp3(v, OP_Column, pAggInfo->sortingIdxPTab,
005072 pAggInfo->aCol[pExpr->iAgg].iSorterColumn,
005073 target);
005074 inReg = target;
005075 break;
005076 }
005077 }
005078 addrINR = sqlite3VdbeAddOp3(v, OP_IfNullRow, pExpr->iTable, 0, target);
005079 /* The OP_IfNullRow opcode above can overwrite the result register with
005080 ** NULL. So we have to ensure that the result register is not a value
005081 ** that is suppose to be a constant. Two defenses are needed:
005082 ** (1) Temporarily disable factoring of constant expressions
005083 ** (2) Make sure the computed value really is stored in register
005084 ** "target" and not someplace else.
005085 */
005086 pParse->okConstFactor = 0; /* note (1) above */
005087 sqlite3ExprCode(pParse, pExpr->pLeft, target);
005088 assert( target==inReg );
005089 pParse->okConstFactor = okConstFactor;
005090 sqlite3VdbeJumpHere(v, addrINR);
005091 break;
005092 }
005093
005094 /*
005095 ** Form A:
005096 ** CASE x WHEN e1 THEN r1 WHEN e2 THEN r2 ... WHEN eN THEN rN ELSE y END
005097 **
005098 ** Form B:
005099 ** CASE WHEN e1 THEN r1 WHEN e2 THEN r2 ... WHEN eN THEN rN ELSE y END
005100 **
005101 ** Form A is can be transformed into the equivalent form B as follows:
005102 ** CASE WHEN x=e1 THEN r1 WHEN x=e2 THEN r2 ...
005103 ** WHEN x=eN THEN rN ELSE y END
005104 **
005105 ** X (if it exists) is in pExpr->pLeft.
005106 ** Y is in the last element of pExpr->x.pList if pExpr->x.pList->nExpr is
005107 ** odd. The Y is also optional. If the number of elements in x.pList
005108 ** is even, then Y is omitted and the "otherwise" result is NULL.
005109 ** Ei is in pExpr->pList->a[i*2] and Ri is pExpr->pList->a[i*2+1].
005110 **
005111 ** The result of the expression is the Ri for the first matching Ei,
005112 ** or if there is no matching Ei, the ELSE term Y, or if there is
005113 ** no ELSE term, NULL.
005114 */
005115 case TK_CASE: {
005116 int endLabel; /* GOTO label for end of CASE stmt */
005117 int nextCase; /* GOTO label for next WHEN clause */
005118 int nExpr; /* 2x number of WHEN terms */
005119 int i; /* Loop counter */
005120 ExprList *pEList; /* List of WHEN terms */
005121 struct ExprList_item *aListelem; /* Array of WHEN terms */
005122 Expr opCompare; /* The X==Ei expression */
005123 Expr *pX; /* The X expression */
005124 Expr *pTest = 0; /* X==Ei (form A) or just Ei (form B) */
005125 Expr *pDel = 0;
005126 sqlite3 *db = pParse->db;
005127
005128 assert( ExprUseXList(pExpr) && pExpr->x.pList!=0 );
005129 assert(pExpr->x.pList->nExpr > 0);
005130 pEList = pExpr->x.pList;
005131 aListelem = pEList->a;
005132 nExpr = pEList->nExpr;
005133 endLabel = sqlite3VdbeMakeLabel(pParse);
005134 if( (pX = pExpr->pLeft)!=0 ){
005135 pDel = sqlite3ExprDup(db, pX, 0);
005136 if( db->mallocFailed ){
005137 sqlite3ExprDelete(db, pDel);
005138 break;
005139 }
005140 testcase( pX->op==TK_COLUMN );
005141 exprToRegister(pDel, exprCodeVector(pParse, pDel, ®Free1));
005142 testcase( regFree1==0 );
005143 memset(&opCompare, 0, sizeof(opCompare));
005144 opCompare.op = TK_EQ;
005145 opCompare.pLeft = pDel;
005146 pTest = &opCompare;
005147 /* Ticket b351d95f9cd5ef17e9d9dbae18f5ca8611190001:
005148 ** The value in regFree1 might get SCopy-ed into the file result.
005149 ** So make sure that the regFree1 register is not reused for other
005150 ** purposes and possibly overwritten. */
005151 regFree1 = 0;
005152 }
005153 for(i=0; i<nExpr-1; i=i+2){
005154 if( pX ){
005155 assert( pTest!=0 );
005156 opCompare.pRight = aListelem[i].pExpr;
005157 }else{
005158 pTest = aListelem[i].pExpr;
005159 }
005160 nextCase = sqlite3VdbeMakeLabel(pParse);
005161 testcase( pTest->op==TK_COLUMN );
005162 sqlite3ExprIfFalse(pParse, pTest, nextCase, SQLITE_JUMPIFNULL);
005163 testcase( aListelem[i+1].pExpr->op==TK_COLUMN );
005164 sqlite3ExprCode(pParse, aListelem[i+1].pExpr, target);
005165 sqlite3VdbeGoto(v, endLabel);
005166 sqlite3VdbeResolveLabel(v, nextCase);
005167 }
005168 if( (nExpr&1)!=0 ){
005169 sqlite3ExprCode(pParse, pEList->a[nExpr-1].pExpr, target);
005170 }else{
005171 sqlite3VdbeAddOp2(v, OP_Null, 0, target);
005172 }
005173 sqlite3ExprDelete(db, pDel);
005174 setDoNotMergeFlagOnCopy(v);
005175 sqlite3VdbeResolveLabel(v, endLabel);
005176 break;
005177 }
005178 #ifndef SQLITE_OMIT_TRIGGER
005179 case TK_RAISE: {
005180 assert( pExpr->affExpr==OE_Rollback
005181 || pExpr->affExpr==OE_Abort
005182 || pExpr->affExpr==OE_Fail
005183 || pExpr->affExpr==OE_Ignore
005184 );
005185 if( !pParse->pTriggerTab && !pParse->nested ){
005186 sqlite3ErrorMsg(pParse,
005187 "RAISE() may only be used within a trigger-program");
005188 return 0;
005189 }
005190 if( pExpr->affExpr==OE_Abort ){
005191 sqlite3MayAbort(pParse);
005192 }
005193 assert( !ExprHasProperty(pExpr, EP_IntValue) );
005194 if( pExpr->affExpr==OE_Ignore ){
005195 sqlite3VdbeAddOp4(
005196 v, OP_Halt, SQLITE_OK, OE_Ignore, 0, pExpr->u.zToken,0);
005197 VdbeCoverage(v);
005198 }else{
005199 sqlite3HaltConstraint(pParse,
005200 pParse->pTriggerTab ? SQLITE_CONSTRAINT_TRIGGER : SQLITE_ERROR,
005201 pExpr->affExpr, pExpr->u.zToken, 0, 0);
005202 }
005203
005204 break;
005205 }
005206 #endif
005207 }
005208 sqlite3ReleaseTempReg(pParse, regFree1);
005209 sqlite3ReleaseTempReg(pParse, regFree2);
005210 return inReg;
005211 }
005212
005213 /*
005214 ** Generate code that will evaluate expression pExpr just one time
005215 ** per prepared statement execution.
005216 **
005217 ** If the expression uses functions (that might throw an exception) then
005218 ** guard them with an OP_Once opcode to ensure that the code is only executed
005219 ** once. If no functions are involved, then factor the code out and put it at
005220 ** the end of the prepared statement in the initialization section.
005221 **
005222 ** If regDest>0 then the result is always stored in that register and the
005223 ** result is not reusable. If regDest<0 then this routine is free to
005224 ** store the value wherever it wants. The register where the expression
005225 ** is stored is returned. When regDest<0, two identical expressions might
005226 ** code to the same register, if they do not contain function calls and hence
005227 ** are factored out into the initialization section at the end of the
005228 ** prepared statement.
005229 */
005230 int sqlite3ExprCodeRunJustOnce(
005231 Parse *pParse, /* Parsing context */
005232 Expr *pExpr, /* The expression to code when the VDBE initializes */
005233 int regDest /* Store the value in this register */
005234 ){
005235 ExprList *p;
005236 assert( ConstFactorOk(pParse) );
005237 assert( regDest!=0 );
005238 p = pParse->pConstExpr;
005239 if( regDest<0 && p ){
005240 struct ExprList_item *pItem;
005241 int i;
005242 for(pItem=p->a, i=p->nExpr; i>0; pItem++, i--){
005243 if( pItem->fg.reusable
005244 && sqlite3ExprCompare(0,pItem->pExpr,pExpr,-1)==0
005245 ){
005246 return pItem->u.iConstExprReg;
005247 }
005248 }
005249 }
005250 pExpr = sqlite3ExprDup(pParse->db, pExpr, 0);
005251 if( pExpr!=0 && ExprHasProperty(pExpr, EP_HasFunc) ){
005252 Vdbe *v = pParse->pVdbe;
005253 int addr;
005254 assert( v );
005255 addr = sqlite3VdbeAddOp0(v, OP_Once); VdbeCoverage(v);
005256 pParse->okConstFactor = 0;
005257 if( !pParse->db->mallocFailed ){
005258 if( regDest<0 ) regDest = ++pParse->nMem;
005259 sqlite3ExprCode(pParse, pExpr, regDest);
005260 }
005261 pParse->okConstFactor = 1;
005262 sqlite3ExprDelete(pParse->db, pExpr);
005263 sqlite3VdbeJumpHere(v, addr);
005264 }else{
005265 p = sqlite3ExprListAppend(pParse, p, pExpr);
005266 if( p ){
005267 struct ExprList_item *pItem = &p->a[p->nExpr-1];
005268 pItem->fg.reusable = regDest<0;
005269 if( regDest<0 ) regDest = ++pParse->nMem;
005270 pItem->u.iConstExprReg = regDest;
005271 }
005272 pParse->pConstExpr = p;
005273 }
005274 return regDest;
005275 }
005276
005277 /*
005278 ** Generate code to evaluate an expression and store the results
005279 ** into a register. Return the register number where the results
005280 ** are stored.
005281 **
005282 ** If the register is a temporary register that can be deallocated,
005283 ** then write its number into *pReg. If the result register is not
005284 ** a temporary, then set *pReg to zero.
005285 **
005286 ** If pExpr is a constant, then this routine might generate this
005287 ** code to fill the register in the initialization section of the
005288 ** VDBE program, in order to factor it out of the evaluation loop.
005289 */
005290 int sqlite3ExprCodeTemp(Parse *pParse, Expr *pExpr, int *pReg){
005291 int r2;
005292 pExpr = sqlite3ExprSkipCollateAndLikely(pExpr);
005293 if( ConstFactorOk(pParse)
005294 && ALWAYS(pExpr!=0)
005295 && pExpr->op!=TK_REGISTER
005296 && sqlite3ExprIsConstantNotJoin(pExpr)
005297 ){
005298 *pReg = 0;
005299 r2 = sqlite3ExprCodeRunJustOnce(pParse, pExpr, -1);
005300 }else{
005301 int r1 = sqlite3GetTempReg(pParse);
005302 r2 = sqlite3ExprCodeTarget(pParse, pExpr, r1);
005303 if( r2==r1 ){
005304 *pReg = r1;
005305 }else{
005306 sqlite3ReleaseTempReg(pParse, r1);
005307 *pReg = 0;
005308 }
005309 }
005310 return r2;
005311 }
005312
005313 /*
005314 ** Generate code that will evaluate expression pExpr and store the
005315 ** results in register target. The results are guaranteed to appear
005316 ** in register target.
005317 */
005318 void sqlite3ExprCode(Parse *pParse, Expr *pExpr, int target){
005319 int inReg;
005320
005321 assert( pExpr==0 || !ExprHasVVAProperty(pExpr,EP_Immutable) );
005322 assert( target>0 && target<=pParse->nMem );
005323 assert( pParse->pVdbe!=0 || pParse->db->mallocFailed );
005324 if( pParse->pVdbe==0 ) return;
005325 inReg = sqlite3ExprCodeTarget(pParse, pExpr, target);
005326 if( inReg!=target ){
005327 u8 op;
005328 Expr *pX = sqlite3ExprSkipCollateAndLikely(pExpr);
005329 testcase( pX!=pExpr );
005330 if( ALWAYS(pX)
005331 && (ExprHasProperty(pX,EP_Subquery) || pX->op==TK_REGISTER)
005332 ){
005333 op = OP_Copy;
005334 }else{
005335 op = OP_SCopy;
005336 }
005337 sqlite3VdbeAddOp2(pParse->pVdbe, op, inReg, target);
005338 }
005339 }
005340
005341 /*
005342 ** Make a transient copy of expression pExpr and then code it using
005343 ** sqlite3ExprCode(). This routine works just like sqlite3ExprCode()
005344 ** except that the input expression is guaranteed to be unchanged.
005345 */
005346 void sqlite3ExprCodeCopy(Parse *pParse, Expr *pExpr, int target){
005347 sqlite3 *db = pParse->db;
005348 pExpr = sqlite3ExprDup(db, pExpr, 0);
005349 if( !db->mallocFailed ) sqlite3ExprCode(pParse, pExpr, target);
005350 sqlite3ExprDelete(db, pExpr);
005351 }
005352
005353 /*
005354 ** Generate code that will evaluate expression pExpr and store the
005355 ** results in register target. The results are guaranteed to appear
005356 ** in register target. If the expression is constant, then this routine
005357 ** might choose to code the expression at initialization time.
005358 */
005359 void sqlite3ExprCodeFactorable(Parse *pParse, Expr *pExpr, int target){
005360 if( pParse->okConstFactor && sqlite3ExprIsConstantNotJoin(pExpr) ){
005361 sqlite3ExprCodeRunJustOnce(pParse, pExpr, target);
005362 }else{
005363 sqlite3ExprCodeCopy(pParse, pExpr, target);
005364 }
005365 }
005366
005367 /*
005368 ** Generate code that pushes the value of every element of the given
005369 ** expression list into a sequence of registers beginning at target.
005370 **
005371 ** Return the number of elements evaluated. The number returned will
005372 ** usually be pList->nExpr but might be reduced if SQLITE_ECEL_OMITREF
005373 ** is defined.
005374 **
005375 ** The SQLITE_ECEL_DUP flag prevents the arguments from being
005376 ** filled using OP_SCopy. OP_Copy must be used instead.
005377 **
005378 ** The SQLITE_ECEL_FACTOR argument allows constant arguments to be
005379 ** factored out into initialization code.
005380 **
005381 ** The SQLITE_ECEL_REF flag means that expressions in the list with
005382 ** ExprList.a[].u.x.iOrderByCol>0 have already been evaluated and stored
005383 ** in registers at srcReg, and so the value can be copied from there.
005384 ** If SQLITE_ECEL_OMITREF is also set, then the values with u.x.iOrderByCol>0
005385 ** are simply omitted rather than being copied from srcReg.
005386 */
005387 int sqlite3ExprCodeExprList(
005388 Parse *pParse, /* Parsing context */
005389 ExprList *pList, /* The expression list to be coded */
005390 int target, /* Where to write results */
005391 int srcReg, /* Source registers if SQLITE_ECEL_REF */
005392 u8 flags /* SQLITE_ECEL_* flags */
005393 ){
005394 struct ExprList_item *pItem;
005395 int i, j, n;
005396 u8 copyOp = (flags & SQLITE_ECEL_DUP) ? OP_Copy : OP_SCopy;
005397 Vdbe *v = pParse->pVdbe;
005398 assert( pList!=0 );
005399 assert( target>0 );
005400 assert( pParse->pVdbe!=0 ); /* Never gets this far otherwise */
005401 n = pList->nExpr;
005402 if( !ConstFactorOk(pParse) ) flags &= ~SQLITE_ECEL_FACTOR;
005403 for(pItem=pList->a, i=0; i<n; i++, pItem++){
005404 Expr *pExpr = pItem->pExpr;
005405 #ifdef SQLITE_ENABLE_SORTER_REFERENCES
005406 if( pItem->fg.bSorterRef ){
005407 i--;
005408 n--;
005409 }else
005410 #endif
005411 if( (flags & SQLITE_ECEL_REF)!=0 && (j = pItem->u.x.iOrderByCol)>0 ){
005412 if( flags & SQLITE_ECEL_OMITREF ){
005413 i--;
005414 n--;
005415 }else{
005416 sqlite3VdbeAddOp2(v, copyOp, j+srcReg-1, target+i);
005417 }
005418 }else if( (flags & SQLITE_ECEL_FACTOR)!=0
005419 && sqlite3ExprIsConstantNotJoin(pExpr)
005420 ){
005421 sqlite3ExprCodeRunJustOnce(pParse, pExpr, target+i);
005422 }else{
005423 int inReg = sqlite3ExprCodeTarget(pParse, pExpr, target+i);
005424 if( inReg!=target+i ){
005425 VdbeOp *pOp;
005426 if( copyOp==OP_Copy
005427 && (pOp=sqlite3VdbeGetLastOp(v))->opcode==OP_Copy
005428 && pOp->p1+pOp->p3+1==inReg
005429 && pOp->p2+pOp->p3+1==target+i
005430 && pOp->p5==0 /* The do-not-merge flag must be clear */
005431 ){
005432 pOp->p3++;
005433 }else{
005434 sqlite3VdbeAddOp2(v, copyOp, inReg, target+i);
005435 }
005436 }
005437 }
005438 }
005439 return n;
005440 }
005441
005442 /*
005443 ** Generate code for a BETWEEN operator.
005444 **
005445 ** x BETWEEN y AND z
005446 **
005447 ** The above is equivalent to
005448 **
005449 ** x>=y AND x<=z
005450 **
005451 ** Code it as such, taking care to do the common subexpression
005452 ** elimination of x.
005453 **
005454 ** The xJumpIf parameter determines details:
005455 **
005456 ** NULL: Store the boolean result in reg[dest]
005457 ** sqlite3ExprIfTrue: Jump to dest if true
005458 ** sqlite3ExprIfFalse: Jump to dest if false
005459 **
005460 ** The jumpIfNull parameter is ignored if xJumpIf is NULL.
005461 */
005462 static void exprCodeBetween(
005463 Parse *pParse, /* Parsing and code generating context */
005464 Expr *pExpr, /* The BETWEEN expression */
005465 int dest, /* Jump destination or storage location */
005466 void (*xJump)(Parse*,Expr*,int,int), /* Action to take */
005467 int jumpIfNull /* Take the jump if the BETWEEN is NULL */
005468 ){
005469 Expr exprAnd; /* The AND operator in x>=y AND x<=z */
005470 Expr compLeft; /* The x>=y term */
005471 Expr compRight; /* The x<=z term */
005472 int regFree1 = 0; /* Temporary use register */
005473 Expr *pDel = 0;
005474 sqlite3 *db = pParse->db;
005475
005476 memset(&compLeft, 0, sizeof(Expr));
005477 memset(&compRight, 0, sizeof(Expr));
005478 memset(&exprAnd, 0, sizeof(Expr));
005479
005480 assert( ExprUseXList(pExpr) );
005481 pDel = sqlite3ExprDup(db, pExpr->pLeft, 0);
005482 if( db->mallocFailed==0 ){
005483 exprAnd.op = TK_AND;
005484 exprAnd.pLeft = &compLeft;
005485 exprAnd.pRight = &compRight;
005486 compLeft.op = TK_GE;
005487 compLeft.pLeft = pDel;
005488 compLeft.pRight = pExpr->x.pList->a[0].pExpr;
005489 compRight.op = TK_LE;
005490 compRight.pLeft = pDel;
005491 compRight.pRight = pExpr->x.pList->a[1].pExpr;
005492 exprToRegister(pDel, exprCodeVector(pParse, pDel, ®Free1));
005493 if( xJump ){
005494 xJump(pParse, &exprAnd, dest, jumpIfNull);
005495 }else{
005496 /* Mark the expression is being from the ON or USING clause of a join
005497 ** so that the sqlite3ExprCodeTarget() routine will not attempt to move
005498 ** it into the Parse.pConstExpr list. We should use a new bit for this,
005499 ** for clarity, but we are out of bits in the Expr.flags field so we
005500 ** have to reuse the EP_OuterON bit. Bummer. */
005501 pDel->flags |= EP_OuterON;
005502 sqlite3ExprCodeTarget(pParse, &exprAnd, dest);
005503 }
005504 sqlite3ReleaseTempReg(pParse, regFree1);
005505 }
005506 sqlite3ExprDelete(db, pDel);
005507
005508 /* Ensure adequate test coverage */
005509 testcase( xJump==sqlite3ExprIfTrue && jumpIfNull==0 && regFree1==0 );
005510 testcase( xJump==sqlite3ExprIfTrue && jumpIfNull==0 && regFree1!=0 );
005511 testcase( xJump==sqlite3ExprIfTrue && jumpIfNull!=0 && regFree1==0 );
005512 testcase( xJump==sqlite3ExprIfTrue && jumpIfNull!=0 && regFree1!=0 );
005513 testcase( xJump==sqlite3ExprIfFalse && jumpIfNull==0 && regFree1==0 );
005514 testcase( xJump==sqlite3ExprIfFalse && jumpIfNull==0 && regFree1!=0 );
005515 testcase( xJump==sqlite3ExprIfFalse && jumpIfNull!=0 && regFree1==0 );
005516 testcase( xJump==sqlite3ExprIfFalse && jumpIfNull!=0 && regFree1!=0 );
005517 testcase( xJump==0 );
005518 }
005519
005520 /*
005521 ** Generate code for a boolean expression such that a jump is made
005522 ** to the label "dest" if the expression is true but execution
005523 ** continues straight thru if the expression is false.
005524 **
005525 ** If the expression evaluates to NULL (neither true nor false), then
005526 ** take the jump if the jumpIfNull flag is SQLITE_JUMPIFNULL.
005527 **
005528 ** This code depends on the fact that certain token values (ex: TK_EQ)
005529 ** are the same as opcode values (ex: OP_Eq) that implement the corresponding
005530 ** operation. Special comments in vdbe.c and the mkopcodeh.awk script in
005531 ** the make process cause these values to align. Assert()s in the code
005532 ** below verify that the numbers are aligned correctly.
005533 */
005534 void sqlite3ExprIfTrue(Parse *pParse, Expr *pExpr, int dest, int jumpIfNull){
005535 Vdbe *v = pParse->pVdbe;
005536 int op = 0;
005537 int regFree1 = 0;
005538 int regFree2 = 0;
005539 int r1, r2;
005540
005541 assert( jumpIfNull==SQLITE_JUMPIFNULL || jumpIfNull==0 );
005542 if( NEVER(v==0) ) return; /* Existence of VDBE checked by caller */
005543 if( NEVER(pExpr==0) ) return; /* No way this can happen */
005544 assert( !ExprHasVVAProperty(pExpr, EP_Immutable) );
005545 op = pExpr->op;
005546 switch( op ){
005547 case TK_AND:
005548 case TK_OR: {
005549 Expr *pAlt = sqlite3ExprSimplifiedAndOr(pExpr);
005550 if( pAlt!=pExpr ){
005551 sqlite3ExprIfTrue(pParse, pAlt, dest, jumpIfNull);
005552 }else if( op==TK_AND ){
005553 int d2 = sqlite3VdbeMakeLabel(pParse);
005554 testcase( jumpIfNull==0 );
005555 sqlite3ExprIfFalse(pParse, pExpr->pLeft, d2,
005556 jumpIfNull^SQLITE_JUMPIFNULL);
005557 sqlite3ExprIfTrue(pParse, pExpr->pRight, dest, jumpIfNull);
005558 sqlite3VdbeResolveLabel(v, d2);
005559 }else{
005560 testcase( jumpIfNull==0 );
005561 sqlite3ExprIfTrue(pParse, pExpr->pLeft, dest, jumpIfNull);
005562 sqlite3ExprIfTrue(pParse, pExpr->pRight, dest, jumpIfNull);
005563 }
005564 break;
005565 }
005566 case TK_NOT: {
005567 testcase( jumpIfNull==0 );
005568 sqlite3ExprIfFalse(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 sqlite3ExprIfTrue(pParse, pExpr->pLeft, dest,
005581 isNot ? SQLITE_JUMPIFNULL : 0);
005582 }else{
005583 sqlite3ExprIfFalse(pParse, pExpr->pLeft, dest,
005584 isNot ? SQLITE_JUMPIFNULL : 0);
005585 }
005586 break;
005587 }
005588 case TK_IS:
005589 case TK_ISNOT:
005590 testcase( op==TK_IS );
005591 testcase( op==TK_ISNOT );
005592 op = (op==TK_IS) ? TK_EQ : TK_NE;
005593 jumpIfNull = SQLITE_NULLEQ;
005594 /* no break */ deliberate_fall_through
005595 case TK_LT:
005596 case TK_LE:
005597 case TK_GT:
005598 case TK_GE:
005599 case TK_NE:
005600 case TK_EQ: {
005601 if( sqlite3ExprIsVector(pExpr->pLeft) ) goto default_expr;
005602 testcase( jumpIfNull==0 );
005603 r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free1);
005604 r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, ®Free2);
005605 codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op,
005606 r1, r2, dest, jumpIfNull, ExprHasProperty(pExpr,EP_Commuted));
005607 assert(TK_LT==OP_Lt); testcase(op==OP_Lt); VdbeCoverageIf(v,op==OP_Lt);
005608 assert(TK_LE==OP_Le); testcase(op==OP_Le); VdbeCoverageIf(v,op==OP_Le);
005609 assert(TK_GT==OP_Gt); testcase(op==OP_Gt); VdbeCoverageIf(v,op==OP_Gt);
005610 assert(TK_GE==OP_Ge); testcase(op==OP_Ge); VdbeCoverageIf(v,op==OP_Ge);
005611 assert(TK_EQ==OP_Eq); testcase(op==OP_Eq);
005612 VdbeCoverageIf(v, op==OP_Eq && jumpIfNull==SQLITE_NULLEQ);
005613 VdbeCoverageIf(v, op==OP_Eq && jumpIfNull!=SQLITE_NULLEQ);
005614 assert(TK_NE==OP_Ne); testcase(op==OP_Ne);
005615 VdbeCoverageIf(v, op==OP_Ne && jumpIfNull==SQLITE_NULLEQ);
005616 VdbeCoverageIf(v, op==OP_Ne && jumpIfNull!=SQLITE_NULLEQ);
005617 testcase( regFree1==0 );
005618 testcase( regFree2==0 );
005619 break;
005620 }
005621 case TK_ISNULL:
005622 case TK_NOTNULL: {
005623 assert( TK_ISNULL==OP_IsNull ); testcase( op==TK_ISNULL );
005624 assert( TK_NOTNULL==OP_NotNull ); testcase( op==TK_NOTNULL );
005625 r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free1);
005626 sqlite3VdbeTypeofColumn(v, r1);
005627 sqlite3VdbeAddOp2(v, op, r1, dest);
005628 VdbeCoverageIf(v, op==TK_ISNULL);
005629 VdbeCoverageIf(v, op==TK_NOTNULL);
005630 testcase( regFree1==0 );
005631 break;
005632 }
005633 case TK_BETWEEN: {
005634 testcase( jumpIfNull==0 );
005635 exprCodeBetween(pParse, pExpr, dest, sqlite3ExprIfTrue, jumpIfNull);
005636 break;
005637 }
005638 #ifndef SQLITE_OMIT_SUBQUERY
005639 case TK_IN: {
005640 int destIfFalse = sqlite3VdbeMakeLabel(pParse);
005641 int destIfNull = jumpIfNull ? dest : destIfFalse;
005642 sqlite3ExprCodeIN(pParse, pExpr, destIfFalse, destIfNull);
005643 sqlite3VdbeGoto(v, dest);
005644 sqlite3VdbeResolveLabel(v, destIfFalse);
005645 break;
005646 }
005647 #endif
005648 default: {
005649 default_expr:
005650 if( ExprAlwaysTrue(pExpr) ){
005651 sqlite3VdbeGoto(v, dest);
005652 }else if( ExprAlwaysFalse(pExpr) ){
005653 /* No-op */
005654 }else{
005655 r1 = sqlite3ExprCodeTemp(pParse, pExpr, ®Free1);
005656 sqlite3VdbeAddOp3(v, OP_If, r1, dest, jumpIfNull!=0);
005657 VdbeCoverage(v);
005658 testcase( regFree1==0 );
005659 testcase( jumpIfNull==0 );
005660 }
005661 break;
005662 }
005663 }
005664 sqlite3ReleaseTempReg(pParse, regFree1);
005665 sqlite3ReleaseTempReg(pParse, regFree2);
005666 }
005667
005668 /*
005669 ** Generate code for a boolean expression such that a jump is made
005670 ** to the label "dest" if the expression is false but execution
005671 ** continues straight thru if the expression is true.
005672 **
005673 ** If the expression evaluates to NULL (neither true nor false) then
005674 ** jump if jumpIfNull is SQLITE_JUMPIFNULL or fall through if jumpIfNull
005675 ** is 0.
005676 */
005677 void sqlite3ExprIfFalse(Parse *pParse, Expr *pExpr, int dest, int jumpIfNull){
005678 Vdbe *v = pParse->pVdbe;
005679 int op = 0;
005680 int regFree1 = 0;
005681 int regFree2 = 0;
005682 int r1, r2;
005683
005684 assert( jumpIfNull==SQLITE_JUMPIFNULL || jumpIfNull==0 );
005685 if( NEVER(v==0) ) return; /* Existence of VDBE checked by caller */
005686 if( pExpr==0 ) return;
005687 assert( !ExprHasVVAProperty(pExpr,EP_Immutable) );
005688
005689 /* The value of pExpr->op and op are related as follows:
005690 **
005691 ** pExpr->op op
005692 ** --------- ----------
005693 ** TK_ISNULL OP_NotNull
005694 ** TK_NOTNULL OP_IsNull
005695 ** TK_NE OP_Eq
005696 ** TK_EQ OP_Ne
005697 ** TK_GT OP_Le
005698 ** TK_LE OP_Gt
005699 ** TK_GE OP_Lt
005700 ** TK_LT OP_Ge
005701 **
005702 ** For other values of pExpr->op, op is undefined and unused.
005703 ** The value of TK_ and OP_ constants are arranged such that we
005704 ** can compute the mapping above using the following expression.
005705 ** Assert()s verify that the computation is correct.
005706 */
005707 op = ((pExpr->op+(TK_ISNULL&1))^1)-(TK_ISNULL&1);
005708
005709 /* Verify correct alignment of TK_ and OP_ constants
005710 */
005711 assert( pExpr->op!=TK_ISNULL || op==OP_NotNull );
005712 assert( pExpr->op!=TK_NOTNULL || op==OP_IsNull );
005713 assert( pExpr->op!=TK_NE || op==OP_Eq );
005714 assert( pExpr->op!=TK_EQ || op==OP_Ne );
005715 assert( pExpr->op!=TK_LT || op==OP_Ge );
005716 assert( pExpr->op!=TK_LE || op==OP_Gt );
005717 assert( pExpr->op!=TK_GT || op==OP_Le );
005718 assert( pExpr->op!=TK_GE || op==OP_Lt );
005719
005720 switch( pExpr->op ){
005721 case TK_AND:
005722 case TK_OR: {
005723 Expr *pAlt = sqlite3ExprSimplifiedAndOr(pExpr);
005724 if( pAlt!=pExpr ){
005725 sqlite3ExprIfFalse(pParse, pAlt, dest, jumpIfNull);
005726 }else if( pExpr->op==TK_AND ){
005727 testcase( jumpIfNull==0 );
005728 sqlite3ExprIfFalse(pParse, pExpr->pLeft, dest, jumpIfNull);
005729 sqlite3ExprIfFalse(pParse, pExpr->pRight, dest, jumpIfNull);
005730 }else{
005731 int d2 = sqlite3VdbeMakeLabel(pParse);
005732 testcase( jumpIfNull==0 );
005733 sqlite3ExprIfTrue(pParse, pExpr->pLeft, d2,
005734 jumpIfNull^SQLITE_JUMPIFNULL);
005735 sqlite3ExprIfFalse(pParse, pExpr->pRight, dest, jumpIfNull);
005736 sqlite3VdbeResolveLabel(v, d2);
005737 }
005738 break;
005739 }
005740 case TK_NOT: {
005741 testcase( jumpIfNull==0 );
005742 sqlite3ExprIfTrue(pParse, pExpr->pLeft, dest, jumpIfNull);
005743 break;
005744 }
005745 case TK_TRUTH: {
005746 int isNot; /* IS NOT TRUE or IS NOT FALSE */
005747 int isTrue; /* IS TRUE or IS NOT TRUE */
005748 testcase( jumpIfNull==0 );
005749 isNot = pExpr->op2==TK_ISNOT;
005750 isTrue = sqlite3ExprTruthValue(pExpr->pRight);
005751 testcase( isTrue && isNot );
005752 testcase( !isTrue && isNot );
005753 if( isTrue ^ isNot ){
005754 /* IS TRUE and IS NOT FALSE */
005755 sqlite3ExprIfFalse(pParse, pExpr->pLeft, dest,
005756 isNot ? 0 : SQLITE_JUMPIFNULL);
005757
005758 }else{
005759 /* IS FALSE and IS NOT TRUE */
005760 sqlite3ExprIfTrue(pParse, pExpr->pLeft, dest,
005761 isNot ? 0 : SQLITE_JUMPIFNULL);
005762 }
005763 break;
005764 }
005765 case TK_IS:
005766 case TK_ISNOT:
005767 testcase( pExpr->op==TK_IS );
005768 testcase( pExpr->op==TK_ISNOT );
005769 op = (pExpr->op==TK_IS) ? TK_NE : TK_EQ;
005770 jumpIfNull = SQLITE_NULLEQ;
005771 /* no break */ deliberate_fall_through
005772 case TK_LT:
005773 case TK_LE:
005774 case TK_GT:
005775 case TK_GE:
005776 case TK_NE:
005777 case TK_EQ: {
005778 if( sqlite3ExprIsVector(pExpr->pLeft) ) goto default_expr;
005779 testcase( jumpIfNull==0 );
005780 r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free1);
005781 r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, ®Free2);
005782 codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op,
005783 r1, r2, dest, jumpIfNull,ExprHasProperty(pExpr,EP_Commuted));
005784 assert(TK_LT==OP_Lt); testcase(op==OP_Lt); VdbeCoverageIf(v,op==OP_Lt);
005785 assert(TK_LE==OP_Le); testcase(op==OP_Le); VdbeCoverageIf(v,op==OP_Le);
005786 assert(TK_GT==OP_Gt); testcase(op==OP_Gt); VdbeCoverageIf(v,op==OP_Gt);
005787 assert(TK_GE==OP_Ge); testcase(op==OP_Ge); VdbeCoverageIf(v,op==OP_Ge);
005788 assert(TK_EQ==OP_Eq); testcase(op==OP_Eq);
005789 VdbeCoverageIf(v, op==OP_Eq && jumpIfNull!=SQLITE_NULLEQ);
005790 VdbeCoverageIf(v, op==OP_Eq && jumpIfNull==SQLITE_NULLEQ);
005791 assert(TK_NE==OP_Ne); testcase(op==OP_Ne);
005792 VdbeCoverageIf(v, op==OP_Ne && jumpIfNull!=SQLITE_NULLEQ);
005793 VdbeCoverageIf(v, op==OP_Ne && jumpIfNull==SQLITE_NULLEQ);
005794 testcase( regFree1==0 );
005795 testcase( regFree2==0 );
005796 break;
005797 }
005798 case TK_ISNULL:
005799 case TK_NOTNULL: {
005800 r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free1);
005801 sqlite3VdbeTypeofColumn(v, r1);
005802 sqlite3VdbeAddOp2(v, op, r1, dest);
005803 testcase( op==TK_ISNULL ); VdbeCoverageIf(v, op==TK_ISNULL);
005804 testcase( op==TK_NOTNULL ); VdbeCoverageIf(v, op==TK_NOTNULL);
005805 testcase( regFree1==0 );
005806 break;
005807 }
005808 case TK_BETWEEN: {
005809 testcase( jumpIfNull==0 );
005810 exprCodeBetween(pParse, pExpr, dest, sqlite3ExprIfFalse, jumpIfNull);
005811 break;
005812 }
005813 #ifndef SQLITE_OMIT_SUBQUERY
005814 case TK_IN: {
005815 if( jumpIfNull ){
005816 sqlite3ExprCodeIN(pParse, pExpr, dest, dest);
005817 }else{
005818 int destIfNull = sqlite3VdbeMakeLabel(pParse);
005819 sqlite3ExprCodeIN(pParse, pExpr, dest, destIfNull);
005820 sqlite3VdbeResolveLabel(v, destIfNull);
005821 }
005822 break;
005823 }
005824 #endif
005825 default: {
005826 default_expr:
005827 if( ExprAlwaysFalse(pExpr) ){
005828 sqlite3VdbeGoto(v, dest);
005829 }else if( ExprAlwaysTrue(pExpr) ){
005830 /* no-op */
005831 }else{
005832 r1 = sqlite3ExprCodeTemp(pParse, pExpr, ®Free1);
005833 sqlite3VdbeAddOp3(v, OP_IfNot, r1, dest, jumpIfNull!=0);
005834 VdbeCoverage(v);
005835 testcase( regFree1==0 );
005836 testcase( jumpIfNull==0 );
005837 }
005838 break;
005839 }
005840 }
005841 sqlite3ReleaseTempReg(pParse, regFree1);
005842 sqlite3ReleaseTempReg(pParse, regFree2);
005843 }
005844
005845 /*
005846 ** Like sqlite3ExprIfFalse() except that a copy is made of pExpr before
005847 ** code generation, and that copy is deleted after code generation. This
005848 ** ensures that the original pExpr is unchanged.
005849 */
005850 void sqlite3ExprIfFalseDup(Parse *pParse, Expr *pExpr, int dest,int jumpIfNull){
005851 sqlite3 *db = pParse->db;
005852 Expr *pCopy = sqlite3ExprDup(db, pExpr, 0);
005853 if( db->mallocFailed==0 ){
005854 sqlite3ExprIfFalse(pParse, pCopy, dest, jumpIfNull);
005855 }
005856 sqlite3ExprDelete(db, pCopy);
005857 }
005858
005859 /*
005860 ** Expression pVar is guaranteed to be an SQL variable. pExpr may be any
005861 ** type of expression.
005862 **
005863 ** If pExpr is a simple SQL value - an integer, real, string, blob
005864 ** or NULL value - then the VDBE currently being prepared is configured
005865 ** to re-prepare each time a new value is bound to variable pVar.
005866 **
005867 ** Additionally, if pExpr is a simple SQL value and the value is the
005868 ** same as that currently bound to variable pVar, non-zero is returned.
005869 ** Otherwise, if the values are not the same or if pExpr is not a simple
005870 ** SQL value, zero is returned.
005871 */
005872 static int exprCompareVariable(
005873 const Parse *pParse,
005874 const Expr *pVar,
005875 const Expr *pExpr
005876 ){
005877 int res = 0;
005878 int iVar;
005879 sqlite3_value *pL, *pR = 0;
005880
005881 sqlite3ValueFromExpr(pParse->db, pExpr, SQLITE_UTF8, SQLITE_AFF_BLOB, &pR);
005882 if( pR ){
005883 iVar = pVar->iColumn;
005884 sqlite3VdbeSetVarmask(pParse->pVdbe, iVar);
005885 pL = sqlite3VdbeGetBoundValue(pParse->pReprepare, iVar, SQLITE_AFF_BLOB);
005886 if( pL ){
005887 if( sqlite3_value_type(pL)==SQLITE_TEXT ){
005888 sqlite3_value_text(pL); /* Make sure the encoding is UTF-8 */
005889 }
005890 res = 0==sqlite3MemCompare(pL, pR, 0);
005891 }
005892 sqlite3ValueFree(pR);
005893 sqlite3ValueFree(pL);
005894 }
005895
005896 return res;
005897 }
005898
005899 /*
005900 ** Do a deep comparison of two expression trees. Return 0 if the two
005901 ** expressions are completely identical. Return 1 if they differ only
005902 ** by a COLLATE operator at the top level. Return 2 if there are differences
005903 ** other than the top-level COLLATE operator.
005904 **
005905 ** If any subelement of pB has Expr.iTable==(-1) then it is allowed
005906 ** to compare equal to an equivalent element in pA with Expr.iTable==iTab.
005907 **
005908 ** The pA side might be using TK_REGISTER. If that is the case and pB is
005909 ** not using TK_REGISTER but is otherwise equivalent, then still return 0.
005910 **
005911 ** Sometimes this routine will return 2 even if the two expressions
005912 ** really are equivalent. If we cannot prove that the expressions are
005913 ** identical, we return 2 just to be safe. So if this routine
005914 ** returns 2, then you do not really know for certain if the two
005915 ** expressions are the same. But if you get a 0 or 1 return, then you
005916 ** can be sure the expressions are the same. In the places where
005917 ** this routine is used, it does not hurt to get an extra 2 - that
005918 ** just might result in some slightly slower code. But returning
005919 ** an incorrect 0 or 1 could lead to a malfunction.
005920 **
005921 ** If pParse is not NULL then TK_VARIABLE terms in pA with bindings in
005922 ** pParse->pReprepare can be matched against literals in pB. The
005923 ** pParse->pVdbe->expmask bitmask is updated for each variable referenced.
005924 ** If pParse is NULL (the normal case) then any TK_VARIABLE term in
005925 ** Argument pParse should normally be NULL. If it is not NULL and pA or
005926 ** pB causes a return value of 2.
005927 */
005928 int sqlite3ExprCompare(
005929 const Parse *pParse,
005930 const Expr *pA,
005931 const Expr *pB,
005932 int iTab
005933 ){
005934 u32 combinedFlags;
005935 if( pA==0 || pB==0 ){
005936 return pB==pA ? 0 : 2;
005937 }
005938 if( pParse && pA->op==TK_VARIABLE && exprCompareVariable(pParse, pA, pB) ){
005939 return 0;
005940 }
005941 combinedFlags = pA->flags | pB->flags;
005942 if( combinedFlags & EP_IntValue ){
005943 if( (pA->flags&pB->flags&EP_IntValue)!=0 && pA->u.iValue==pB->u.iValue ){
005944 return 0;
005945 }
005946 return 2;
005947 }
005948 if( pA->op!=pB->op || pA->op==TK_RAISE ){
005949 if( pA->op==TK_COLLATE && sqlite3ExprCompare(pParse, pA->pLeft,pB,iTab)<2 ){
005950 return 1;
005951 }
005952 if( pB->op==TK_COLLATE && sqlite3ExprCompare(pParse, pA,pB->pLeft,iTab)<2 ){
005953 return 1;
005954 }
005955 if( pA->op==TK_AGG_COLUMN && pB->op==TK_COLUMN
005956 && pB->iTable<0 && pA->iTable==iTab
005957 ){
005958 /* fall through */
005959 }else{
005960 return 2;
005961 }
005962 }
005963 assert( !ExprHasProperty(pA, EP_IntValue) );
005964 assert( !ExprHasProperty(pB, EP_IntValue) );
005965 if( pA->u.zToken ){
005966 if( pA->op==TK_FUNCTION || pA->op==TK_AGG_FUNCTION ){
005967 if( sqlite3StrICmp(pA->u.zToken,pB->u.zToken)!=0 ) return 2;
005968 #ifndef SQLITE_OMIT_WINDOWFUNC
005969 assert( pA->op==pB->op );
005970 if( ExprHasProperty(pA,EP_WinFunc)!=ExprHasProperty(pB,EP_WinFunc) ){
005971 return 2;
005972 }
005973 if( ExprHasProperty(pA,EP_WinFunc) ){
005974 if( sqlite3WindowCompare(pParse, pA->y.pWin, pB->y.pWin, 1)!=0 ){
005975 return 2;
005976 }
005977 }
005978 #endif
005979 }else if( pA->op==TK_NULL ){
005980 return 0;
005981 }else if( pA->op==TK_COLLATE ){
005982 if( sqlite3_stricmp(pA->u.zToken,pB->u.zToken)!=0 ) return 2;
005983 }else
005984 if( pB->u.zToken!=0
005985 && pA->op!=TK_COLUMN
005986 && pA->op!=TK_AGG_COLUMN
005987 && strcmp(pA->u.zToken,pB->u.zToken)!=0
005988 ){
005989 return 2;
005990 }
005991 }
005992 if( (pA->flags & (EP_Distinct|EP_Commuted))
005993 != (pB->flags & (EP_Distinct|EP_Commuted)) ) return 2;
005994 if( ALWAYS((combinedFlags & EP_TokenOnly)==0) ){
005995 if( combinedFlags & EP_xIsSelect ) return 2;
005996 if( (combinedFlags & EP_FixedCol)==0
005997 && sqlite3ExprCompare(pParse, pA->pLeft, pB->pLeft, iTab) ) return 2;
005998 if( sqlite3ExprCompare(pParse, pA->pRight, pB->pRight, iTab) ) return 2;
005999 if( sqlite3ExprListCompare(pA->x.pList, pB->x.pList, iTab) ) return 2;
006000 if( pA->op!=TK_STRING
006001 && pA->op!=TK_TRUEFALSE
006002 && ALWAYS((combinedFlags & EP_Reduced)==0)
006003 ){
006004 if( pA->iColumn!=pB->iColumn ) return 2;
006005 if( pA->op2!=pB->op2 && pA->op==TK_TRUTH ) return 2;
006006 if( pA->op!=TK_IN && pA->iTable!=pB->iTable && pA->iTable!=iTab ){
006007 return 2;
006008 }
006009 }
006010 }
006011 return 0;
006012 }
006013
006014 /*
006015 ** Compare two ExprList objects. Return 0 if they are identical, 1
006016 ** if they are certainly different, or 2 if it is not possible to
006017 ** determine if they are identical or not.
006018 **
006019 ** If any subelement of pB has Expr.iTable==(-1) then it is allowed
006020 ** to compare equal to an equivalent element in pA with Expr.iTable==iTab.
006021 **
006022 ** This routine might return non-zero for equivalent ExprLists. The
006023 ** only consequence will be disabled optimizations. But this routine
006024 ** must never return 0 if the two ExprList objects are different, or
006025 ** a malfunction will result.
006026 **
006027 ** Two NULL pointers are considered to be the same. But a NULL pointer
006028 ** always differs from a non-NULL pointer.
006029 */
006030 int sqlite3ExprListCompare(const ExprList *pA, const ExprList *pB, int iTab){
006031 int i;
006032 if( pA==0 && pB==0 ) return 0;
006033 if( pA==0 || pB==0 ) return 1;
006034 if( pA->nExpr!=pB->nExpr ) return 1;
006035 for(i=0; i<pA->nExpr; i++){
006036 int res;
006037 Expr *pExprA = pA->a[i].pExpr;
006038 Expr *pExprB = pB->a[i].pExpr;
006039 if( pA->a[i].fg.sortFlags!=pB->a[i].fg.sortFlags ) return 1;
006040 if( (res = sqlite3ExprCompare(0, pExprA, pExprB, iTab)) ) return res;
006041 }
006042 return 0;
006043 }
006044
006045 /*
006046 ** Like sqlite3ExprCompare() except COLLATE operators at the top-level
006047 ** are ignored.
006048 */
006049 int sqlite3ExprCompareSkip(Expr *pA,Expr *pB, int iTab){
006050 return sqlite3ExprCompare(0,
006051 sqlite3ExprSkipCollate(pA),
006052 sqlite3ExprSkipCollate(pB),
006053 iTab);
006054 }
006055
006056 /*
006057 ** Return non-zero if Expr p can only be true if pNN is not NULL.
006058 **
006059 ** Or if seenNot is true, return non-zero if Expr p can only be
006060 ** non-NULL if pNN is not NULL
006061 */
006062 static int exprImpliesNotNull(
006063 const Parse *pParse,/* Parsing context */
006064 const Expr *p, /* The expression to be checked */
006065 const Expr *pNN, /* The expression that is NOT NULL */
006066 int iTab, /* Table being evaluated */
006067 int seenNot /* Return true only if p can be any non-NULL value */
006068 ){
006069 assert( p );
006070 assert( pNN );
006071 if( sqlite3ExprCompare(pParse, p, pNN, iTab)==0 ){
006072 return pNN->op!=TK_NULL;
006073 }
006074 switch( p->op ){
006075 case TK_IN: {
006076 if( seenNot && ExprHasProperty(p, EP_xIsSelect) ) return 0;
006077 assert( ExprUseXSelect(p) || (p->x.pList!=0 && p->x.pList->nExpr>0) );
006078 return exprImpliesNotNull(pParse, p->pLeft, pNN, iTab, 1);
006079 }
006080 case TK_BETWEEN: {
006081 ExprList *pList;
006082 assert( ExprUseXList(p) );
006083 pList = p->x.pList;
006084 assert( pList!=0 );
006085 assert( pList->nExpr==2 );
006086 if( seenNot ) return 0;
006087 if( exprImpliesNotNull(pParse, pList->a[0].pExpr, pNN, iTab, 1)
006088 || exprImpliesNotNull(pParse, pList->a[1].pExpr, pNN, iTab, 1)
006089 ){
006090 return 1;
006091 }
006092 return exprImpliesNotNull(pParse, p->pLeft, pNN, iTab, 1);
006093 }
006094 case TK_EQ:
006095 case TK_NE:
006096 case TK_LT:
006097 case TK_LE:
006098 case TK_GT:
006099 case TK_GE:
006100 case TK_PLUS:
006101 case TK_MINUS:
006102 case TK_BITOR:
006103 case TK_LSHIFT:
006104 case TK_RSHIFT:
006105 case TK_CONCAT:
006106 seenNot = 1;
006107 /* no break */ deliberate_fall_through
006108 case TK_STAR:
006109 case TK_REM:
006110 case TK_BITAND:
006111 case TK_SLASH: {
006112 if( exprImpliesNotNull(pParse, p->pRight, pNN, iTab, seenNot) ) return 1;
006113 /* no break */ deliberate_fall_through
006114 }
006115 case TK_SPAN:
006116 case TK_COLLATE:
006117 case TK_UPLUS:
006118 case TK_UMINUS: {
006119 return exprImpliesNotNull(pParse, p->pLeft, pNN, iTab, seenNot);
006120 }
006121 case TK_TRUTH: {
006122 if( seenNot ) return 0;
006123 if( p->op2!=TK_IS ) return 0;
006124 return exprImpliesNotNull(pParse, p->pLeft, pNN, iTab, 1);
006125 }
006126 case TK_BITNOT:
006127 case TK_NOT: {
006128 return exprImpliesNotNull(pParse, p->pLeft, pNN, iTab, 1);
006129 }
006130 }
006131 return 0;
006132 }
006133
006134 /*
006135 ** Return true if we can prove the pE2 will always be true if pE1 is
006136 ** true. Return false if we cannot complete the proof or if pE2 might
006137 ** be false. Examples:
006138 **
006139 ** pE1: x==5 pE2: x==5 Result: true
006140 ** pE1: x>0 pE2: x==5 Result: false
006141 ** pE1: x=21 pE2: x=21 OR y=43 Result: true
006142 ** pE1: x!=123 pE2: x IS NOT NULL Result: true
006143 ** pE1: x!=?1 pE2: x IS NOT NULL Result: true
006144 ** pE1: x IS NULL pE2: x IS NOT NULL Result: false
006145 ** pE1: x IS ?2 pE2: x IS NOT NULL Result: false
006146 **
006147 ** When comparing TK_COLUMN nodes between pE1 and pE2, if pE2 has
006148 ** Expr.iTable<0 then assume a table number given by iTab.
006149 **
006150 ** If pParse is not NULL, then the values of bound variables in pE1 are
006151 ** compared against literal values in pE2 and pParse->pVdbe->expmask is
006152 ** modified to record which bound variables are referenced. If pParse
006153 ** is NULL, then false will be returned if pE1 contains any bound variables.
006154 **
006155 ** When in doubt, return false. Returning true might give a performance
006156 ** improvement. Returning false might cause a performance reduction, but
006157 ** it will always give the correct answer and is hence always safe.
006158 */
006159 int sqlite3ExprImpliesExpr(
006160 const Parse *pParse,
006161 const Expr *pE1,
006162 const Expr *pE2,
006163 int iTab
006164 ){
006165 if( sqlite3ExprCompare(pParse, pE1, pE2, iTab)==0 ){
006166 return 1;
006167 }
006168 if( pE2->op==TK_OR
006169 && (sqlite3ExprImpliesExpr(pParse, pE1, pE2->pLeft, iTab)
006170 || sqlite3ExprImpliesExpr(pParse, pE1, pE2->pRight, iTab) )
006171 ){
006172 return 1;
006173 }
006174 if( pE2->op==TK_NOTNULL
006175 && exprImpliesNotNull(pParse, pE1, pE2->pLeft, iTab, 0)
006176 ){
006177 return 1;
006178 }
006179 return 0;
006180 }
006181
006182 /* This is a helper function to impliesNotNullRow(). In this routine,
006183 ** set pWalker->eCode to one only if *both* of the input expressions
006184 ** separately have the implies-not-null-row property.
006185 */
006186 static void bothImplyNotNullRow(Walker *pWalker, Expr *pE1, Expr *pE2){
006187 if( pWalker->eCode==0 ){
006188 sqlite3WalkExpr(pWalker, pE1);
006189 if( pWalker->eCode ){
006190 pWalker->eCode = 0;
006191 sqlite3WalkExpr(pWalker, pE2);
006192 }
006193 }
006194 }
006195
006196 /*
006197 ** This is the Expr node callback for sqlite3ExprImpliesNonNullRow().
006198 ** If the expression node requires that the table at pWalker->iCur
006199 ** have one or more non-NULL column, then set pWalker->eCode to 1 and abort.
006200 **
006201 ** pWalker->mWFlags is non-zero if this inquiry is being undertaking on
006202 ** behalf of a RIGHT JOIN (or FULL JOIN). That makes a difference when
006203 ** evaluating terms in the ON clause of an inner join.
006204 **
006205 ** This routine controls an optimization. False positives (setting
006206 ** pWalker->eCode to 1 when it should not be) are deadly, but false-negatives
006207 ** (never setting pWalker->eCode) is a harmless missed optimization.
006208 */
006209 static int impliesNotNullRow(Walker *pWalker, Expr *pExpr){
006210 testcase( pExpr->op==TK_AGG_COLUMN );
006211 testcase( pExpr->op==TK_AGG_FUNCTION );
006212 if( ExprHasProperty(pExpr, EP_OuterON) ) return WRC_Prune;
006213 if( ExprHasProperty(pExpr, EP_InnerON) && pWalker->mWFlags ){
006214 /* If iCur is used in an inner-join ON clause to the left of a
006215 ** RIGHT JOIN, that does *not* mean that the table must be non-null.
006216 ** But it is difficult to check for that condition precisely.
006217 ** To keep things simple, any use of iCur from any inner-join is
006218 ** ignored while attempting to simplify a RIGHT JOIN. */
006219 return WRC_Prune;
006220 }
006221 switch( pExpr->op ){
006222 case TK_ISNOT:
006223 case TK_ISNULL:
006224 case TK_NOTNULL:
006225 case TK_IS:
006226 case TK_VECTOR:
006227 case TK_FUNCTION:
006228 case TK_TRUTH:
006229 case TK_CASE:
006230 testcase( pExpr->op==TK_ISNOT );
006231 testcase( pExpr->op==TK_ISNULL );
006232 testcase( pExpr->op==TK_NOTNULL );
006233 testcase( pExpr->op==TK_IS );
006234 testcase( pExpr->op==TK_VECTOR );
006235 testcase( pExpr->op==TK_FUNCTION );
006236 testcase( pExpr->op==TK_TRUTH );
006237 testcase( pExpr->op==TK_CASE );
006238 return WRC_Prune;
006239
006240 case TK_COLUMN:
006241 if( pWalker->u.iCur==pExpr->iTable ){
006242 pWalker->eCode = 1;
006243 return WRC_Abort;
006244 }
006245 return WRC_Prune;
006246
006247 case TK_OR:
006248 case TK_AND:
006249 /* Both sides of an AND or OR must separately imply non-null-row.
006250 ** Consider these cases:
006251 ** 1. NOT (x AND y)
006252 ** 2. x OR y
006253 ** If only one of x or y is non-null-row, then the overall expression
006254 ** can be true if the other arm is false (case 1) or true (case 2).
006255 */
006256 testcase( pExpr->op==TK_OR );
006257 testcase( pExpr->op==TK_AND );
006258 bothImplyNotNullRow(pWalker, pExpr->pLeft, pExpr->pRight);
006259 return WRC_Prune;
006260
006261 case TK_IN:
006262 /* Beware of "x NOT IN ()" and "x NOT IN (SELECT 1 WHERE false)",
006263 ** both of which can be true. But apart from these cases, if
006264 ** the left-hand side of the IN is NULL then the IN itself will be
006265 ** NULL. */
006266 if( ExprUseXList(pExpr) && ALWAYS(pExpr->x.pList->nExpr>0) ){
006267 sqlite3WalkExpr(pWalker, pExpr->pLeft);
006268 }
006269 return WRC_Prune;
006270
006271 case TK_BETWEEN:
006272 /* In "x NOT BETWEEN y AND z" either x must be non-null-row or else
006273 ** both y and z must be non-null row */
006274 assert( ExprUseXList(pExpr) );
006275 assert( pExpr->x.pList->nExpr==2 );
006276 sqlite3WalkExpr(pWalker, pExpr->pLeft);
006277 bothImplyNotNullRow(pWalker, pExpr->x.pList->a[0].pExpr,
006278 pExpr->x.pList->a[1].pExpr);
006279 return WRC_Prune;
006280
006281 /* Virtual tables are allowed to use constraints like x=NULL. So
006282 ** a term of the form x=y does not prove that y is not null if x
006283 ** is the column of a virtual table */
006284 case TK_EQ:
006285 case TK_NE:
006286 case TK_LT:
006287 case TK_LE:
006288 case TK_GT:
006289 case TK_GE: {
006290 Expr *pLeft = pExpr->pLeft;
006291 Expr *pRight = pExpr->pRight;
006292 testcase( pExpr->op==TK_EQ );
006293 testcase( pExpr->op==TK_NE );
006294 testcase( pExpr->op==TK_LT );
006295 testcase( pExpr->op==TK_LE );
006296 testcase( pExpr->op==TK_GT );
006297 testcase( pExpr->op==TK_GE );
006298 /* The y.pTab=0 assignment in wherecode.c always happens after the
006299 ** impliesNotNullRow() test */
006300 assert( pLeft->op!=TK_COLUMN || ExprUseYTab(pLeft) );
006301 assert( pRight->op!=TK_COLUMN || ExprUseYTab(pRight) );
006302 if( (pLeft->op==TK_COLUMN
006303 && ALWAYS(pLeft->y.pTab!=0)
006304 && IsVirtual(pLeft->y.pTab))
006305 || (pRight->op==TK_COLUMN
006306 && ALWAYS(pRight->y.pTab!=0)
006307 && IsVirtual(pRight->y.pTab))
006308 ){
006309 return WRC_Prune;
006310 }
006311 /* no break */ deliberate_fall_through
006312 }
006313 default:
006314 return WRC_Continue;
006315 }
006316 }
006317
006318 /*
006319 ** Return true (non-zero) if expression p can only be true if at least
006320 ** one column of table iTab is non-null. In other words, return true
006321 ** if expression p will always be NULL or false if every column of iTab
006322 ** is NULL.
006323 **
006324 ** False negatives are acceptable. In other words, it is ok to return
006325 ** zero even if expression p will never be true of every column of iTab
006326 ** is NULL. A false negative is merely a missed optimization opportunity.
006327 **
006328 ** False positives are not allowed, however. A false positive may result
006329 ** in an incorrect answer.
006330 **
006331 ** Terms of p that are marked with EP_OuterON (and hence that come from
006332 ** the ON or USING clauses of OUTER JOINS) are excluded from the analysis.
006333 **
006334 ** This routine is used to check if a LEFT JOIN can be converted into
006335 ** an ordinary JOIN. The p argument is the WHERE clause. If the WHERE
006336 ** clause requires that some column of the right table of the LEFT JOIN
006337 ** be non-NULL, then the LEFT JOIN can be safely converted into an
006338 ** ordinary join.
006339 */
006340 int sqlite3ExprImpliesNonNullRow(Expr *p, int iTab, int isRJ){
006341 Walker w;
006342 p = sqlite3ExprSkipCollateAndLikely(p);
006343 if( p==0 ) return 0;
006344 if( p->op==TK_NOTNULL ){
006345 p = p->pLeft;
006346 }else{
006347 while( p->op==TK_AND ){
006348 if( sqlite3ExprImpliesNonNullRow(p->pLeft, iTab, isRJ) ) return 1;
006349 p = p->pRight;
006350 }
006351 }
006352 w.xExprCallback = impliesNotNullRow;
006353 w.xSelectCallback = 0;
006354 w.xSelectCallback2 = 0;
006355 w.eCode = 0;
006356 w.mWFlags = isRJ!=0;
006357 w.u.iCur = iTab;
006358 sqlite3WalkExpr(&w, p);
006359 return w.eCode;
006360 }
006361
006362 /*
006363 ** An instance of the following structure is used by the tree walker
006364 ** to determine if an expression can be evaluated by reference to the
006365 ** index only, without having to do a search for the corresponding
006366 ** table entry. The IdxCover.pIdx field is the index. IdxCover.iCur
006367 ** is the cursor for the table.
006368 */
006369 struct IdxCover {
006370 Index *pIdx; /* The index to be tested for coverage */
006371 int iCur; /* Cursor number for the table corresponding to the index */
006372 };
006373
006374 /*
006375 ** Check to see if there are references to columns in table
006376 ** pWalker->u.pIdxCover->iCur can be satisfied using the index
006377 ** pWalker->u.pIdxCover->pIdx.
006378 */
006379 static int exprIdxCover(Walker *pWalker, Expr *pExpr){
006380 if( pExpr->op==TK_COLUMN
006381 && pExpr->iTable==pWalker->u.pIdxCover->iCur
006382 && sqlite3TableColumnToIndex(pWalker->u.pIdxCover->pIdx, pExpr->iColumn)<0
006383 ){
006384 pWalker->eCode = 1;
006385 return WRC_Abort;
006386 }
006387 return WRC_Continue;
006388 }
006389
006390 /*
006391 ** Determine if an index pIdx on table with cursor iCur contains will
006392 ** the expression pExpr. Return true if the index does cover the
006393 ** expression and false if the pExpr expression references table columns
006394 ** that are not found in the index pIdx.
006395 **
006396 ** An index covering an expression means that the expression can be
006397 ** evaluated using only the index and without having to lookup the
006398 ** corresponding table entry.
006399 */
006400 int sqlite3ExprCoveredByIndex(
006401 Expr *pExpr, /* The index to be tested */
006402 int iCur, /* The cursor number for the corresponding table */
006403 Index *pIdx /* The index that might be used for coverage */
006404 ){
006405 Walker w;
006406 struct IdxCover xcov;
006407 memset(&w, 0, sizeof(w));
006408 xcov.iCur = iCur;
006409 xcov.pIdx = pIdx;
006410 w.xExprCallback = exprIdxCover;
006411 w.u.pIdxCover = &xcov;
006412 sqlite3WalkExpr(&w, pExpr);
006413 return !w.eCode;
006414 }
006415
006416
006417 /* Structure used to pass information throughout the Walker in order to
006418 ** implement sqlite3ReferencesSrcList().
006419 */
006420 struct RefSrcList {
006421 sqlite3 *db; /* Database connection used for sqlite3DbRealloc() */
006422 SrcList *pRef; /* Looking for references to these tables */
006423 i64 nExclude; /* Number of tables to exclude from the search */
006424 int *aiExclude; /* Cursor IDs for tables to exclude from the search */
006425 };
006426
006427 /*
006428 ** Walker SELECT callbacks for sqlite3ReferencesSrcList().
006429 **
006430 ** When entering a new subquery on the pExpr argument, add all FROM clause
006431 ** entries for that subquery to the exclude list.
006432 **
006433 ** When leaving the subquery, remove those entries from the exclude list.
006434 */
006435 static int selectRefEnter(Walker *pWalker, Select *pSelect){
006436 struct RefSrcList *p = pWalker->u.pRefSrcList;
006437 SrcList *pSrc = pSelect->pSrc;
006438 i64 i, j;
006439 int *piNew;
006440 if( pSrc->nSrc==0 ) return WRC_Continue;
006441 j = p->nExclude;
006442 p->nExclude += pSrc->nSrc;
006443 piNew = sqlite3DbRealloc(p->db, p->aiExclude, p->nExclude*sizeof(int));
006444 if( piNew==0 ){
006445 p->nExclude = 0;
006446 return WRC_Abort;
006447 }else{
006448 p->aiExclude = piNew;
006449 }
006450 for(i=0; i<pSrc->nSrc; i++, j++){
006451 p->aiExclude[j] = pSrc->a[i].iCursor;
006452 }
006453 return WRC_Continue;
006454 }
006455 static void selectRefLeave(Walker *pWalker, Select *pSelect){
006456 struct RefSrcList *p = pWalker->u.pRefSrcList;
006457 SrcList *pSrc = pSelect->pSrc;
006458 if( p->nExclude ){
006459 assert( p->nExclude>=pSrc->nSrc );
006460 p->nExclude -= pSrc->nSrc;
006461 }
006462 }
006463
006464 /* This is the Walker EXPR callback for sqlite3ReferencesSrcList().
006465 **
006466 ** Set the 0x01 bit of pWalker->eCode if there is a reference to any
006467 ** of the tables shown in RefSrcList.pRef.
006468 **
006469 ** Set the 0x02 bit of pWalker->eCode if there is a reference to a
006470 ** table is in neither RefSrcList.pRef nor RefSrcList.aiExclude.
006471 */
006472 static int exprRefToSrcList(Walker *pWalker, Expr *pExpr){
006473 if( pExpr->op==TK_COLUMN
006474 || pExpr->op==TK_AGG_COLUMN
006475 ){
006476 int i;
006477 struct RefSrcList *p = pWalker->u.pRefSrcList;
006478 SrcList *pSrc = p->pRef;
006479 int nSrc = pSrc ? pSrc->nSrc : 0;
006480 for(i=0; i<nSrc; i++){
006481 if( pExpr->iTable==pSrc->a[i].iCursor ){
006482 pWalker->eCode |= 1;
006483 return WRC_Continue;
006484 }
006485 }
006486 for(i=0; i<p->nExclude && p->aiExclude[i]!=pExpr->iTable; i++){}
006487 if( i>=p->nExclude ){
006488 pWalker->eCode |= 2;
006489 }
006490 }
006491 return WRC_Continue;
006492 }
006493
006494 /*
006495 ** Check to see if pExpr references any tables in pSrcList.
006496 ** Possible return values:
006497 **
006498 ** 1 pExpr does references a table in pSrcList.
006499 **
006500 ** 0 pExpr references some table that is not defined in either
006501 ** pSrcList or in subqueries of pExpr itself.
006502 **
006503 ** -1 pExpr only references no tables at all, or it only
006504 ** references tables defined in subqueries of pExpr itself.
006505 **
006506 ** As currently used, pExpr is always an aggregate function call. That
006507 ** fact is exploited for efficiency.
006508 */
006509 int sqlite3ReferencesSrcList(Parse *pParse, Expr *pExpr, SrcList *pSrcList){
006510 Walker w;
006511 struct RefSrcList x;
006512 assert( pParse->db!=0 );
006513 memset(&w, 0, sizeof(w));
006514 memset(&x, 0, sizeof(x));
006515 w.xExprCallback = exprRefToSrcList;
006516 w.xSelectCallback = selectRefEnter;
006517 w.xSelectCallback2 = selectRefLeave;
006518 w.u.pRefSrcList = &x;
006519 x.db = pParse->db;
006520 x.pRef = pSrcList;
006521 assert( pExpr->op==TK_AGG_FUNCTION );
006522 assert( ExprUseXList(pExpr) );
006523 sqlite3WalkExprList(&w, pExpr->x.pList);
006524 if( pExpr->pLeft ){
006525 assert( pExpr->pLeft->op==TK_ORDER );
006526 assert( ExprUseXList(pExpr->pLeft) );
006527 assert( pExpr->pLeft->x.pList!=0 );
006528 sqlite3WalkExprList(&w, pExpr->pLeft->x.pList);
006529 }
006530 #ifndef SQLITE_OMIT_WINDOWFUNC
006531 if( ExprHasProperty(pExpr, EP_WinFunc) ){
006532 sqlite3WalkExpr(&w, pExpr->y.pWin->pFilter);
006533 }
006534 #endif
006535 if( x.aiExclude ) sqlite3DbNNFreeNN(pParse->db, x.aiExclude);
006536 if( w.eCode & 0x01 ){
006537 return 1;
006538 }else if( w.eCode ){
006539 return 0;
006540 }else{
006541 return -1;
006542 }
006543 }
006544
006545 /*
006546 ** This is a Walker expression node callback.
006547 **
006548 ** For Expr nodes that contain pAggInfo pointers, make sure the AggInfo
006549 ** object that is referenced does not refer directly to the Expr. If
006550 ** it does, make a copy. This is done because the pExpr argument is
006551 ** subject to change.
006552 **
006553 ** The copy is scheduled for deletion using the sqlite3ExprDeferredDelete()
006554 ** which builds on the sqlite3ParserAddCleanup() mechanism.
006555 */
006556 static int agginfoPersistExprCb(Walker *pWalker, Expr *pExpr){
006557 if( ALWAYS(!ExprHasProperty(pExpr, EP_TokenOnly|EP_Reduced))
006558 && pExpr->pAggInfo!=0
006559 ){
006560 AggInfo *pAggInfo = pExpr->pAggInfo;
006561 int iAgg = pExpr->iAgg;
006562 Parse *pParse = pWalker->pParse;
006563 sqlite3 *db = pParse->db;
006564 assert( iAgg>=0 );
006565 if( pExpr->op!=TK_AGG_FUNCTION ){
006566 if( iAgg<pAggInfo->nColumn
006567 && pAggInfo->aCol[iAgg].pCExpr==pExpr
006568 ){
006569 pExpr = sqlite3ExprDup(db, pExpr, 0);
006570 if( pExpr ){
006571 pAggInfo->aCol[iAgg].pCExpr = pExpr;
006572 sqlite3ExprDeferredDelete(pParse, pExpr);
006573 }
006574 }
006575 }else{
006576 assert( pExpr->op==TK_AGG_FUNCTION );
006577 if( ALWAYS(iAgg<pAggInfo->nFunc)
006578 && pAggInfo->aFunc[iAgg].pFExpr==pExpr
006579 ){
006580 pExpr = sqlite3ExprDup(db, pExpr, 0);
006581 if( pExpr ){
006582 pAggInfo->aFunc[iAgg].pFExpr = pExpr;
006583 sqlite3ExprDeferredDelete(pParse, pExpr);
006584 }
006585 }
006586 }
006587 }
006588 return WRC_Continue;
006589 }
006590
006591 /*
006592 ** Initialize a Walker object so that will persist AggInfo entries referenced
006593 ** by the tree that is walked.
006594 */
006595 void sqlite3AggInfoPersistWalkerInit(Walker *pWalker, Parse *pParse){
006596 memset(pWalker, 0, sizeof(*pWalker));
006597 pWalker->pParse = pParse;
006598 pWalker->xExprCallback = agginfoPersistExprCb;
006599 pWalker->xSelectCallback = sqlite3SelectWalkNoop;
006600 }
006601
006602 /*
006603 ** Add a new element to the pAggInfo->aCol[] array. Return the index of
006604 ** the new element. Return a negative number if malloc fails.
006605 */
006606 static int addAggInfoColumn(sqlite3 *db, AggInfo *pInfo){
006607 int i;
006608 pInfo->aCol = sqlite3ArrayAllocate(
006609 db,
006610 pInfo->aCol,
006611 sizeof(pInfo->aCol[0]),
006612 &pInfo->nColumn,
006613 &i
006614 );
006615 return i;
006616 }
006617
006618 /*
006619 ** Add a new element to the pAggInfo->aFunc[] array. Return the index of
006620 ** the new element. Return a negative number if malloc fails.
006621 */
006622 static int addAggInfoFunc(sqlite3 *db, AggInfo *pInfo){
006623 int i;
006624 pInfo->aFunc = sqlite3ArrayAllocate(
006625 db,
006626 pInfo->aFunc,
006627 sizeof(pInfo->aFunc[0]),
006628 &pInfo->nFunc,
006629 &i
006630 );
006631 return i;
006632 }
006633
006634 /*
006635 ** Search the AggInfo object for an aCol[] entry that has iTable and iColumn.
006636 ** Return the index in aCol[] of the entry that describes that column.
006637 **
006638 ** If no prior entry is found, create a new one and return -1. The
006639 ** new column will have an index of pAggInfo->nColumn-1.
006640 */
006641 static void findOrCreateAggInfoColumn(
006642 Parse *pParse, /* Parsing context */
006643 AggInfo *pAggInfo, /* The AggInfo object to search and/or modify */
006644 Expr *pExpr /* Expr describing the column to find or insert */
006645 ){
006646 struct AggInfo_col *pCol;
006647 int k;
006648
006649 assert( pAggInfo->iFirstReg==0 );
006650 pCol = pAggInfo->aCol;
006651 for(k=0; k<pAggInfo->nColumn; k++, pCol++){
006652 if( pCol->pCExpr==pExpr ) return;
006653 if( pCol->iTable==pExpr->iTable
006654 && pCol->iColumn==pExpr->iColumn
006655 && pExpr->op!=TK_IF_NULL_ROW
006656 ){
006657 goto fix_up_expr;
006658 }
006659 }
006660 k = addAggInfoColumn(pParse->db, pAggInfo);
006661 if( k<0 ){
006662 /* OOM on resize */
006663 assert( pParse->db->mallocFailed );
006664 return;
006665 }
006666 pCol = &pAggInfo->aCol[k];
006667 assert( ExprUseYTab(pExpr) );
006668 pCol->pTab = pExpr->y.pTab;
006669 pCol->iTable = pExpr->iTable;
006670 pCol->iColumn = pExpr->iColumn;
006671 pCol->iSorterColumn = -1;
006672 pCol->pCExpr = pExpr;
006673 if( pAggInfo->pGroupBy && pExpr->op!=TK_IF_NULL_ROW ){
006674 int j, n;
006675 ExprList *pGB = pAggInfo->pGroupBy;
006676 struct ExprList_item *pTerm = pGB->a;
006677 n = pGB->nExpr;
006678 for(j=0; j<n; j++, pTerm++){
006679 Expr *pE = pTerm->pExpr;
006680 if( pE->op==TK_COLUMN
006681 && pE->iTable==pExpr->iTable
006682 && pE->iColumn==pExpr->iColumn
006683 ){
006684 pCol->iSorterColumn = j;
006685 break;
006686 }
006687 }
006688 }
006689 if( pCol->iSorterColumn<0 ){
006690 pCol->iSorterColumn = pAggInfo->nSortingColumn++;
006691 }
006692 fix_up_expr:
006693 ExprSetVVAProperty(pExpr, EP_NoReduce);
006694 assert( pExpr->pAggInfo==0 || pExpr->pAggInfo==pAggInfo );
006695 pExpr->pAggInfo = pAggInfo;
006696 if( pExpr->op==TK_COLUMN ){
006697 pExpr->op = TK_AGG_COLUMN;
006698 }
006699 pExpr->iAgg = (i16)k;
006700 }
006701
006702 /*
006703 ** This is the xExprCallback for a tree walker. It is used to
006704 ** implement sqlite3ExprAnalyzeAggregates(). See sqlite3ExprAnalyzeAggregates
006705 ** for additional information.
006706 */
006707 static int analyzeAggregate(Walker *pWalker, Expr *pExpr){
006708 int i;
006709 NameContext *pNC = pWalker->u.pNC;
006710 Parse *pParse = pNC->pParse;
006711 SrcList *pSrcList = pNC->pSrcList;
006712 AggInfo *pAggInfo = pNC->uNC.pAggInfo;
006713
006714 assert( pNC->ncFlags & NC_UAggInfo );
006715 assert( pAggInfo->iFirstReg==0 );
006716 switch( pExpr->op ){
006717 default: {
006718 IndexedExpr *pIEpr;
006719 Expr tmp;
006720 assert( pParse->iSelfTab==0 );
006721 if( (pNC->ncFlags & NC_InAggFunc)==0 ) break;
006722 if( pParse->pIdxEpr==0 ) break;
006723 for(pIEpr=pParse->pIdxEpr; pIEpr; pIEpr=pIEpr->pIENext){
006724 int iDataCur = pIEpr->iDataCur;
006725 if( iDataCur<0 ) continue;
006726 if( sqlite3ExprCompare(0, pExpr, pIEpr->pExpr, iDataCur)==0 ) break;
006727 }
006728 if( pIEpr==0 ) break;
006729 if( NEVER(!ExprUseYTab(pExpr)) ) break;
006730 for(i=0; i<pSrcList->nSrc; i++){
006731 if( pSrcList->a[0].iCursor==pIEpr->iDataCur ) break;
006732 }
006733 if( i>=pSrcList->nSrc ) break;
006734 if( NEVER(pExpr->pAggInfo!=0) ) break; /* Resolved by outer context */
006735 if( pParse->nErr ){ return WRC_Abort; }
006736
006737 /* If we reach this point, it means that expression pExpr can be
006738 ** translated into a reference to an index column as described by
006739 ** pIEpr.
006740 */
006741 memset(&tmp, 0, sizeof(tmp));
006742 tmp.op = TK_AGG_COLUMN;
006743 tmp.iTable = pIEpr->iIdxCur;
006744 tmp.iColumn = pIEpr->iIdxCol;
006745 findOrCreateAggInfoColumn(pParse, pAggInfo, &tmp);
006746 if( pParse->nErr ){ return WRC_Abort; }
006747 assert( pAggInfo->aCol!=0 );
006748 assert( tmp.iAgg<pAggInfo->nColumn );
006749 pAggInfo->aCol[tmp.iAgg].pCExpr = pExpr;
006750 pExpr->pAggInfo = pAggInfo;
006751 pExpr->iAgg = tmp.iAgg;
006752 return WRC_Prune;
006753 }
006754 case TK_IF_NULL_ROW:
006755 case TK_AGG_COLUMN:
006756 case TK_COLUMN: {
006757 testcase( pExpr->op==TK_AGG_COLUMN );
006758 testcase( pExpr->op==TK_COLUMN );
006759 testcase( pExpr->op==TK_IF_NULL_ROW );
006760 /* Check to see if the column is in one of the tables in the FROM
006761 ** clause of the aggregate query */
006762 if( ALWAYS(pSrcList!=0) ){
006763 SrcItem *pItem = pSrcList->a;
006764 for(i=0; i<pSrcList->nSrc; i++, pItem++){
006765 assert( !ExprHasProperty(pExpr, EP_TokenOnly|EP_Reduced) );
006766 if( pExpr->iTable==pItem->iCursor ){
006767 findOrCreateAggInfoColumn(pParse, pAggInfo, pExpr);
006768 break;
006769 } /* endif pExpr->iTable==pItem->iCursor */
006770 } /* end loop over pSrcList */
006771 }
006772 return WRC_Continue;
006773 }
006774 case TK_AGG_FUNCTION: {
006775 if( (pNC->ncFlags & NC_InAggFunc)==0
006776 && pWalker->walkerDepth==pExpr->op2
006777 && pExpr->pAggInfo==0
006778 ){
006779 /* Check to see if pExpr is a duplicate of another aggregate
006780 ** function that is already in the pAggInfo structure
006781 */
006782 struct AggInfo_func *pItem = pAggInfo->aFunc;
006783 for(i=0; i<pAggInfo->nFunc; i++, pItem++){
006784 if( NEVER(pItem->pFExpr==pExpr) ) break;
006785 if( sqlite3ExprCompare(0, pItem->pFExpr, pExpr, -1)==0 ){
006786 break;
006787 }
006788 }
006789 if( i>=pAggInfo->nFunc ){
006790 /* pExpr is original. Make a new entry in pAggInfo->aFunc[]
006791 */
006792 u8 enc = ENC(pParse->db);
006793 i = addAggInfoFunc(pParse->db, pAggInfo);
006794 if( i>=0 ){
006795 int nArg;
006796 assert( !ExprHasProperty(pExpr, EP_xIsSelect) );
006797 pItem = &pAggInfo->aFunc[i];
006798 pItem->pFExpr = pExpr;
006799 assert( ExprUseUToken(pExpr) );
006800 nArg = pExpr->x.pList ? pExpr->x.pList->nExpr : 0;
006801 pItem->pFunc = sqlite3FindFunction(pParse->db,
006802 pExpr->u.zToken, nArg, enc, 0);
006803 assert( pItem->bOBUnique==0 );
006804 if( pExpr->pLeft
006805 && (pItem->pFunc->funcFlags & SQLITE_FUNC_NEEDCOLL)==0
006806 ){
006807 /* The NEEDCOLL test above causes any ORDER BY clause on
006808 ** aggregate min() or max() to be ignored. */
006809 ExprList *pOBList;
006810 assert( nArg>0 );
006811 assert( pExpr->pLeft->op==TK_ORDER );
006812 assert( ExprUseXList(pExpr->pLeft) );
006813 pItem->iOBTab = pParse->nTab++;
006814 pOBList = pExpr->pLeft->x.pList;
006815 assert( pOBList->nExpr>0 );
006816 assert( pItem->bOBUnique==0 );
006817 if( pOBList->nExpr==1
006818 && nArg==1
006819 && sqlite3ExprCompare(0,pOBList->a[0].pExpr,
006820 pExpr->x.pList->a[0].pExpr,0)==0
006821 ){
006822 pItem->bOBPayload = 0;
006823 pItem->bOBUnique = ExprHasProperty(pExpr, EP_Distinct);
006824 }else{
006825 pItem->bOBPayload = 1;
006826 }
006827 pItem->bUseSubtype =
006828 (pItem->pFunc->funcFlags & SQLITE_SUBTYPE)!=0;
006829 }else{
006830 pItem->iOBTab = -1;
006831 }
006832 if( ExprHasProperty(pExpr, EP_Distinct) && !pItem->bOBUnique ){
006833 pItem->iDistinct = pParse->nTab++;
006834 }else{
006835 pItem->iDistinct = -1;
006836 }
006837 }
006838 }
006839 /* Make pExpr point to the appropriate pAggInfo->aFunc[] entry
006840 */
006841 assert( !ExprHasProperty(pExpr, EP_TokenOnly|EP_Reduced) );
006842 ExprSetVVAProperty(pExpr, EP_NoReduce);
006843 pExpr->iAgg = (i16)i;
006844 pExpr->pAggInfo = pAggInfo;
006845 return WRC_Prune;
006846 }else{
006847 return WRC_Continue;
006848 }
006849 }
006850 }
006851 return WRC_Continue;
006852 }
006853
006854 /*
006855 ** Analyze the pExpr expression looking for aggregate functions and
006856 ** for variables that need to be added to AggInfo object that pNC->pAggInfo
006857 ** points to. Additional entries are made on the AggInfo object as
006858 ** necessary.
006859 **
006860 ** This routine should only be called after the expression has been
006861 ** analyzed by sqlite3ResolveExprNames().
006862 */
006863 void sqlite3ExprAnalyzeAggregates(NameContext *pNC, Expr *pExpr){
006864 Walker w;
006865 w.xExprCallback = analyzeAggregate;
006866 w.xSelectCallback = sqlite3WalkerDepthIncrease;
006867 w.xSelectCallback2 = sqlite3WalkerDepthDecrease;
006868 w.walkerDepth = 0;
006869 w.u.pNC = pNC;
006870 w.pParse = 0;
006871 assert( pNC->pSrcList!=0 );
006872 sqlite3WalkExpr(&w, pExpr);
006873 }
006874
006875 /*
006876 ** Call sqlite3ExprAnalyzeAggregates() for every expression in an
006877 ** expression list. Return the number of errors.
006878 **
006879 ** If an error is found, the analysis is cut short.
006880 */
006881 void sqlite3ExprAnalyzeAggList(NameContext *pNC, ExprList *pList){
006882 struct ExprList_item *pItem;
006883 int i;
006884 if( pList ){
006885 for(pItem=pList->a, i=0; i<pList->nExpr; i++, pItem++){
006886 sqlite3ExprAnalyzeAggregates(pNC, pItem->pExpr);
006887 }
006888 }
006889 }
006890
006891 /*
006892 ** Allocate a single new register for use to hold some intermediate result.
006893 */
006894 int sqlite3GetTempReg(Parse *pParse){
006895 if( pParse->nTempReg==0 ){
006896 return ++pParse->nMem;
006897 }
006898 return pParse->aTempReg[--pParse->nTempReg];
006899 }
006900
006901 /*
006902 ** Deallocate a register, making available for reuse for some other
006903 ** purpose.
006904 */
006905 void sqlite3ReleaseTempReg(Parse *pParse, int iReg){
006906 if( iReg ){
006907 sqlite3VdbeReleaseRegisters(pParse, iReg, 1, 0, 0);
006908 if( pParse->nTempReg<ArraySize(pParse->aTempReg) ){
006909 pParse->aTempReg[pParse->nTempReg++] = iReg;
006910 }
006911 }
006912 }
006913
006914 /*
006915 ** Allocate or deallocate a block of nReg consecutive registers.
006916 */
006917 int sqlite3GetTempRange(Parse *pParse, int nReg){
006918 int i, n;
006919 if( nReg==1 ) return sqlite3GetTempReg(pParse);
006920 i = pParse->iRangeReg;
006921 n = pParse->nRangeReg;
006922 if( nReg<=n ){
006923 pParse->iRangeReg += nReg;
006924 pParse->nRangeReg -= nReg;
006925 }else{
006926 i = pParse->nMem+1;
006927 pParse->nMem += nReg;
006928 }
006929 return i;
006930 }
006931 void sqlite3ReleaseTempRange(Parse *pParse, int iReg, int nReg){
006932 if( nReg==1 ){
006933 sqlite3ReleaseTempReg(pParse, iReg);
006934 return;
006935 }
006936 sqlite3VdbeReleaseRegisters(pParse, iReg, nReg, 0, 0);
006937 if( nReg>pParse->nRangeReg ){
006938 pParse->nRangeReg = nReg;
006939 pParse->iRangeReg = iReg;
006940 }
006941 }
006942
006943 /*
006944 ** Mark all temporary registers as being unavailable for reuse.
006945 **
006946 ** Always invoke this procedure after coding a subroutine or co-routine
006947 ** that might be invoked from other parts of the code, to ensure that
006948 ** the sub/co-routine does not use registers in common with the code that
006949 ** invokes the sub/co-routine.
006950 */
006951 void sqlite3ClearTempRegCache(Parse *pParse){
006952 pParse->nTempReg = 0;
006953 pParse->nRangeReg = 0;
006954 }
006955
006956 /*
006957 ** Make sure sufficient registers have been allocated so that
006958 ** iReg is a valid register number.
006959 */
006960 void sqlite3TouchRegister(Parse *pParse, int iReg){
006961 if( pParse->nMem<iReg ) pParse->nMem = iReg;
006962 }
006963
006964 #if defined(SQLITE_ENABLE_STAT4) || defined(SQLITE_DEBUG)
006965 /*
006966 ** Return the latest reusable register in the set of all registers.
006967 ** The value returned is no less than iMin. If any register iMin or
006968 ** greater is in permanent use, then return one more than that last
006969 ** permanent register.
006970 */
006971 int sqlite3FirstAvailableRegister(Parse *pParse, int iMin){
006972 const ExprList *pList = pParse->pConstExpr;
006973 if( pList ){
006974 int i;
006975 for(i=0; i<pList->nExpr; i++){
006976 if( pList->a[i].u.iConstExprReg>=iMin ){
006977 iMin = pList->a[i].u.iConstExprReg + 1;
006978 }
006979 }
006980 }
006981 pParse->nTempReg = 0;
006982 pParse->nRangeReg = 0;
006983 return iMin;
006984 }
006985 #endif /* SQLITE_ENABLE_STAT4 || SQLITE_DEBUG */
006986
006987 /*
006988 ** Validate that no temporary register falls within the range of
006989 ** iFirst..iLast, inclusive. This routine is only call from within assert()
006990 ** statements.
006991 */
006992 #ifdef SQLITE_DEBUG
006993 int sqlite3NoTempsInRange(Parse *pParse, int iFirst, int iLast){
006994 int i;
006995 if( pParse->nRangeReg>0
006996 && pParse->iRangeReg+pParse->nRangeReg > iFirst
006997 && pParse->iRangeReg <= iLast
006998 ){
006999 return 0;
007000 }
007001 for(i=0; i<pParse->nTempReg; i++){
007002 if( pParse->aTempReg[i]>=iFirst && pParse->aTempReg[i]<=iLast ){
007003 return 0;
007004 }
007005 }
007006 if( pParse->pConstExpr ){
007007 ExprList *pList = pParse->pConstExpr;
007008 for(i=0; i<pList->nExpr; i++){
007009 int iReg = pList->a[i].u.iConstExprReg;
007010 if( iReg==0 ) continue;
007011 if( iReg>=iFirst && iReg<=iLast ) return 0;
007012 }
007013 }
007014 return 1;
007015 }
007016 #endif /* SQLITE_DEBUG */