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(Table *pTab, int iCol){
000025 assert( iCol<pTab->nCol );
000026 return iCol>=0 ? pTab->aCol[iCol].affinity : SQLITE_AFF_INTEGER;
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(Expr *pExpr){
000046 int op;
000047 while( ExprHasProperty(pExpr, EP_Skip) ){
000048 assert( pExpr->op==TK_COLLATE );
000049 pExpr = pExpr->pLeft;
000050 assert( pExpr!=0 );
000051 }
000052 op = pExpr->op;
000053 if( op==TK_SELECT ){
000054 assert( pExpr->flags&EP_xIsSelect );
000055 return sqlite3ExprAffinity(pExpr->x.pSelect->pEList->a[0].pExpr);
000056 }
000057 if( op==TK_REGISTER ) op = pExpr->op2;
000058 #ifndef SQLITE_OMIT_CAST
000059 if( op==TK_CAST ){
000060 assert( !ExprHasProperty(pExpr, EP_IntValue) );
000061 return sqlite3AffinityType(pExpr->u.zToken, 0);
000062 }
000063 #endif
000064 if( (op==TK_AGG_COLUMN || op==TK_COLUMN) && pExpr->y.pTab ){
000065 return sqlite3TableColumnAffinity(pExpr->y.pTab, pExpr->iColumn);
000066 }
000067 if( op==TK_SELECT_COLUMN ){
000068 assert( pExpr->pLeft->flags&EP_xIsSelect );
000069 return sqlite3ExprAffinity(
000070 pExpr->pLeft->x.pSelect->pEList->a[pExpr->iColumn].pExpr
000071 );
000072 }
000073 if( op==TK_VECTOR ){
000074 return sqlite3ExprAffinity(pExpr->x.pList->a[0].pExpr);
000075 }
000076 return pExpr->affExpr;
000077 }
000078
000079 /*
000080 ** Set the collating sequence for expression pExpr to be the collating
000081 ** sequence named by pToken. Return a pointer to a new Expr node that
000082 ** implements the COLLATE operator.
000083 **
000084 ** If a memory allocation error occurs, that fact is recorded in pParse->db
000085 ** and the pExpr parameter is returned unchanged.
000086 */
000087 Expr *sqlite3ExprAddCollateToken(
000088 Parse *pParse, /* Parsing context */
000089 Expr *pExpr, /* Add the "COLLATE" clause to this expression */
000090 const Token *pCollName, /* Name of collating sequence */
000091 int dequote /* True to dequote pCollName */
000092 ){
000093 if( pCollName->n>0 ){
000094 Expr *pNew = sqlite3ExprAlloc(pParse->db, TK_COLLATE, pCollName, dequote);
000095 if( pNew ){
000096 pNew->pLeft = pExpr;
000097 pNew->flags |= EP_Collate|EP_Skip;
000098 pExpr = pNew;
000099 }
000100 }
000101 return pExpr;
000102 }
000103 Expr *sqlite3ExprAddCollateString(Parse *pParse, Expr *pExpr, const char *zC){
000104 Token s;
000105 assert( zC!=0 );
000106 sqlite3TokenInit(&s, (char*)zC);
000107 return sqlite3ExprAddCollateToken(pParse, pExpr, &s, 0);
000108 }
000109
000110 /*
000111 ** Skip over any TK_COLLATE operators.
000112 */
000113 Expr *sqlite3ExprSkipCollate(Expr *pExpr){
000114 while( pExpr && ExprHasProperty(pExpr, EP_Skip) ){
000115 assert( pExpr->op==TK_COLLATE );
000116 pExpr = pExpr->pLeft;
000117 }
000118 return pExpr;
000119 }
000120
000121 /*
000122 ** Skip over any TK_COLLATE operators and/or any unlikely()
000123 ** or likelihood() or likely() functions at the root of an
000124 ** expression.
000125 */
000126 Expr *sqlite3ExprSkipCollateAndLikely(Expr *pExpr){
000127 while( pExpr && ExprHasProperty(pExpr, EP_Skip|EP_Unlikely) ){
000128 if( ExprHasProperty(pExpr, EP_Unlikely) ){
000129 assert( !ExprHasProperty(pExpr, EP_xIsSelect) );
000130 assert( pExpr->x.pList->nExpr>0 );
000131 assert( pExpr->op==TK_FUNCTION );
000132 pExpr = pExpr->x.pList->a[0].pExpr;
000133 }else{
000134 assert( pExpr->op==TK_COLLATE );
000135 pExpr = pExpr->pLeft;
000136 }
000137 }
000138 return pExpr;
000139 }
000140
000141 /*
000142 ** Return the collation sequence for the expression pExpr. If
000143 ** there is no defined collating sequence, return NULL.
000144 **
000145 ** See also: sqlite3ExprNNCollSeq()
000146 **
000147 ** The sqlite3ExprNNCollSeq() works the same exact that it returns the
000148 ** default collation if pExpr has no defined collation.
000149 **
000150 ** The collating sequence might be determined by a COLLATE operator
000151 ** or by the presence of a column with a defined collating sequence.
000152 ** COLLATE operators take first precedence. Left operands take
000153 ** precedence over right operands.
000154 */
000155 CollSeq *sqlite3ExprCollSeq(Parse *pParse, Expr *pExpr){
000156 sqlite3 *db = pParse->db;
000157 CollSeq *pColl = 0;
000158 Expr *p = pExpr;
000159 while( p ){
000160 int op = p->op;
000161 if( op==TK_REGISTER ) op = p->op2;
000162 if( (op==TK_AGG_COLUMN || op==TK_COLUMN || op==TK_TRIGGER)
000163 && p->y.pTab!=0
000164 ){
000165 /* op==TK_REGISTER && p->y.pTab!=0 happens when pExpr was originally
000166 ** a TK_COLUMN but was previously evaluated and cached in a register */
000167 int j = p->iColumn;
000168 if( j>=0 ){
000169 const char *zColl = p->y.pTab->aCol[j].zColl;
000170 pColl = sqlite3FindCollSeq(db, ENC(db), zColl, 0);
000171 }
000172 break;
000173 }
000174 if( op==TK_CAST || op==TK_UPLUS ){
000175 p = p->pLeft;
000176 continue;
000177 }
000178 if( op==TK_VECTOR ){
000179 p = p->x.pList->a[0].pExpr;
000180 continue;
000181 }
000182 if( op==TK_COLLATE ){
000183 pColl = sqlite3GetCollSeq(pParse, ENC(db), 0, p->u.zToken);
000184 break;
000185 }
000186 if( p->flags & EP_Collate ){
000187 if( p->pLeft && (p->pLeft->flags & EP_Collate)!=0 ){
000188 p = p->pLeft;
000189 }else{
000190 Expr *pNext = p->pRight;
000191 /* The Expr.x union is never used at the same time as Expr.pRight */
000192 assert( p->x.pList==0 || p->pRight==0 );
000193 if( p->x.pList!=0
000194 && !db->mallocFailed
000195 && ALWAYS(!ExprHasProperty(p, EP_xIsSelect))
000196 ){
000197 int i;
000198 for(i=0; i<p->x.pList->nExpr; i++){
000199 if( ExprHasProperty(p->x.pList->a[i].pExpr, EP_Collate) ){
000200 pNext = p->x.pList->a[i].pExpr;
000201 break;
000202 }
000203 }
000204 }
000205 p = pNext;
000206 }
000207 }else{
000208 break;
000209 }
000210 }
000211 if( sqlite3CheckCollSeq(pParse, pColl) ){
000212 pColl = 0;
000213 }
000214 return pColl;
000215 }
000216
000217 /*
000218 ** Return the collation sequence for the expression pExpr. If
000219 ** there is no defined collating sequence, return a pointer to the
000220 ** defautl collation sequence.
000221 **
000222 ** See also: sqlite3ExprCollSeq()
000223 **
000224 ** The sqlite3ExprCollSeq() routine works the same except that it
000225 ** returns NULL if there is no defined collation.
000226 */
000227 CollSeq *sqlite3ExprNNCollSeq(Parse *pParse, Expr *pExpr){
000228 CollSeq *p = sqlite3ExprCollSeq(pParse, pExpr);
000229 if( p==0 ) p = pParse->db->pDfltColl;
000230 assert( p!=0 );
000231 return p;
000232 }
000233
000234 /*
000235 ** Return TRUE if the two expressions have equivalent collating sequences.
000236 */
000237 int sqlite3ExprCollSeqMatch(Parse *pParse, Expr *pE1, Expr *pE2){
000238 CollSeq *pColl1 = sqlite3ExprNNCollSeq(pParse, pE1);
000239 CollSeq *pColl2 = sqlite3ExprNNCollSeq(pParse, pE2);
000240 return sqlite3StrICmp(pColl1->zName, pColl2->zName)==0;
000241 }
000242
000243 /*
000244 ** pExpr is an operand of a comparison operator. aff2 is the
000245 ** type affinity of the other operand. This routine returns the
000246 ** type affinity that should be used for the comparison operator.
000247 */
000248 char sqlite3CompareAffinity(Expr *pExpr, char aff2){
000249 char aff1 = sqlite3ExprAffinity(pExpr);
000250 if( aff1>SQLITE_AFF_NONE && aff2>SQLITE_AFF_NONE ){
000251 /* Both sides of the comparison are columns. If one has numeric
000252 ** affinity, use that. Otherwise use no affinity.
000253 */
000254 if( sqlite3IsNumericAffinity(aff1) || sqlite3IsNumericAffinity(aff2) ){
000255 return SQLITE_AFF_NUMERIC;
000256 }else{
000257 return SQLITE_AFF_BLOB;
000258 }
000259 }else{
000260 /* One side is a column, the other is not. Use the columns affinity. */
000261 assert( aff1<=SQLITE_AFF_NONE || aff2<=SQLITE_AFF_NONE );
000262 return (aff1<=SQLITE_AFF_NONE ? aff2 : aff1) | SQLITE_AFF_NONE;
000263 }
000264 }
000265
000266 /*
000267 ** pExpr is a comparison operator. Return the type affinity that should
000268 ** be applied to both operands prior to doing the comparison.
000269 */
000270 static char comparisonAffinity(Expr *pExpr){
000271 char aff;
000272 assert( pExpr->op==TK_EQ || pExpr->op==TK_IN || pExpr->op==TK_LT ||
000273 pExpr->op==TK_GT || pExpr->op==TK_GE || pExpr->op==TK_LE ||
000274 pExpr->op==TK_NE || pExpr->op==TK_IS || pExpr->op==TK_ISNOT );
000275 assert( pExpr->pLeft );
000276 aff = sqlite3ExprAffinity(pExpr->pLeft);
000277 if( pExpr->pRight ){
000278 aff = sqlite3CompareAffinity(pExpr->pRight, aff);
000279 }else if( ExprHasProperty(pExpr, EP_xIsSelect) ){
000280 aff = sqlite3CompareAffinity(pExpr->x.pSelect->pEList->a[0].pExpr, aff);
000281 }else if( aff==0 ){
000282 aff = SQLITE_AFF_BLOB;
000283 }
000284 return aff;
000285 }
000286
000287 /*
000288 ** pExpr is a comparison expression, eg. '=', '<', IN(...) etc.
000289 ** idx_affinity is the affinity of an indexed column. Return true
000290 ** if the index with affinity idx_affinity may be used to implement
000291 ** the comparison in pExpr.
000292 */
000293 int sqlite3IndexAffinityOk(Expr *pExpr, char idx_affinity){
000294 char aff = comparisonAffinity(pExpr);
000295 if( aff<SQLITE_AFF_TEXT ){
000296 return 1;
000297 }
000298 if( aff==SQLITE_AFF_TEXT ){
000299 return idx_affinity==SQLITE_AFF_TEXT;
000300 }
000301 return sqlite3IsNumericAffinity(idx_affinity);
000302 }
000303
000304 /*
000305 ** Return the P5 value that should be used for a binary comparison
000306 ** opcode (OP_Eq, OP_Ge etc.) used to compare pExpr1 and pExpr2.
000307 */
000308 static u8 binaryCompareP5(Expr *pExpr1, Expr *pExpr2, int jumpIfNull){
000309 u8 aff = (char)sqlite3ExprAffinity(pExpr2);
000310 aff = (u8)sqlite3CompareAffinity(pExpr1, aff) | (u8)jumpIfNull;
000311 return aff;
000312 }
000313
000314 /*
000315 ** Return a pointer to the collation sequence that should be used by
000316 ** a binary comparison operator comparing pLeft and pRight.
000317 **
000318 ** If the left hand expression has a collating sequence type, then it is
000319 ** used. Otherwise the collation sequence for the right hand expression
000320 ** is used, or the default (BINARY) if neither expression has a collating
000321 ** type.
000322 **
000323 ** Argument pRight (but not pLeft) may be a null pointer. In this case,
000324 ** it is not considered.
000325 */
000326 CollSeq *sqlite3BinaryCompareCollSeq(
000327 Parse *pParse,
000328 Expr *pLeft,
000329 Expr *pRight
000330 ){
000331 CollSeq *pColl;
000332 assert( pLeft );
000333 if( pLeft->flags & EP_Collate ){
000334 pColl = sqlite3ExprCollSeq(pParse, pLeft);
000335 }else if( pRight && (pRight->flags & EP_Collate)!=0 ){
000336 pColl = sqlite3ExprCollSeq(pParse, pRight);
000337 }else{
000338 pColl = sqlite3ExprCollSeq(pParse, pLeft);
000339 if( !pColl ){
000340 pColl = sqlite3ExprCollSeq(pParse, pRight);
000341 }
000342 }
000343 return pColl;
000344 }
000345
000346 /* Expresssion p is a comparison operator. Return a collation sequence
000347 ** appropriate for the comparison operator.
000348 **
000349 ** This is normally just a wrapper around sqlite3BinaryCompareCollSeq().
000350 ** However, if the OP_Commuted flag is set, then the order of the operands
000351 ** is reversed in the sqlite3BinaryCompareCollSeq() call so that the
000352 ** correct collating sequence is found.
000353 */
000354 CollSeq *sqlite3ExprCompareCollSeq(Parse *pParse, Expr *p){
000355 if( ExprHasProperty(p, EP_Commuted) ){
000356 return sqlite3BinaryCompareCollSeq(pParse, p->pRight, p->pLeft);
000357 }else{
000358 return sqlite3BinaryCompareCollSeq(pParse, p->pLeft, p->pRight);
000359 }
000360 }
000361
000362 /*
000363 ** Generate code for a comparison operator.
000364 */
000365 static int codeCompare(
000366 Parse *pParse, /* The parsing (and code generating) context */
000367 Expr *pLeft, /* The left operand */
000368 Expr *pRight, /* The right operand */
000369 int opcode, /* The comparison opcode */
000370 int in1, int in2, /* Register holding operands */
000371 int dest, /* Jump here if true. */
000372 int jumpIfNull, /* If true, jump if either operand is NULL */
000373 int isCommuted /* The comparison has been commuted */
000374 ){
000375 int p5;
000376 int addr;
000377 CollSeq *p4;
000378
000379 if( pParse->nErr ) return 0;
000380 if( isCommuted ){
000381 p4 = sqlite3BinaryCompareCollSeq(pParse, pRight, pLeft);
000382 }else{
000383 p4 = sqlite3BinaryCompareCollSeq(pParse, pLeft, pRight);
000384 }
000385 p5 = binaryCompareP5(pLeft, pRight, jumpIfNull);
000386 addr = sqlite3VdbeAddOp4(pParse->pVdbe, opcode, in2, dest, in1,
000387 (void*)p4, P4_COLLSEQ);
000388 sqlite3VdbeChangeP5(pParse->pVdbe, (u8)p5);
000389 return addr;
000390 }
000391
000392 /*
000393 ** Return true if expression pExpr is a vector, or false otherwise.
000394 **
000395 ** A vector is defined as any expression that results in two or more
000396 ** columns of result. Every TK_VECTOR node is an vector because the
000397 ** parser will not generate a TK_VECTOR with fewer than two entries.
000398 ** But a TK_SELECT might be either a vector or a scalar. It is only
000399 ** considered a vector if it has two or more result columns.
000400 */
000401 int sqlite3ExprIsVector(Expr *pExpr){
000402 return sqlite3ExprVectorSize(pExpr)>1;
000403 }
000404
000405 /*
000406 ** If the expression passed as the only argument is of type TK_VECTOR
000407 ** return the number of expressions in the vector. Or, if the expression
000408 ** is a sub-select, return the number of columns in the sub-select. For
000409 ** any other type of expression, return 1.
000410 */
000411 int sqlite3ExprVectorSize(Expr *pExpr){
000412 u8 op = pExpr->op;
000413 if( op==TK_REGISTER ) op = pExpr->op2;
000414 if( op==TK_VECTOR ){
000415 return pExpr->x.pList->nExpr;
000416 }else if( op==TK_SELECT ){
000417 return pExpr->x.pSelect->pEList->nExpr;
000418 }else{
000419 return 1;
000420 }
000421 }
000422
000423 /*
000424 ** Return a pointer to a subexpression of pVector that is the i-th
000425 ** column of the vector (numbered starting with 0). The caller must
000426 ** ensure that i is within range.
000427 **
000428 ** If pVector is really a scalar (and "scalar" here includes subqueries
000429 ** that return a single column!) then return pVector unmodified.
000430 **
000431 ** pVector retains ownership of the returned subexpression.
000432 **
000433 ** If the vector is a (SELECT ...) then the expression returned is
000434 ** just the expression for the i-th term of the result set, and may
000435 ** not be ready for evaluation because the table cursor has not yet
000436 ** been positioned.
000437 */
000438 Expr *sqlite3VectorFieldSubexpr(Expr *pVector, int i){
000439 assert( i<sqlite3ExprVectorSize(pVector) );
000440 if( sqlite3ExprIsVector(pVector) ){
000441 assert( pVector->op2==0 || pVector->op==TK_REGISTER );
000442 if( pVector->op==TK_SELECT || pVector->op2==TK_SELECT ){
000443 return pVector->x.pSelect->pEList->a[i].pExpr;
000444 }else{
000445 return pVector->x.pList->a[i].pExpr;
000446 }
000447 }
000448 return pVector;
000449 }
000450
000451 /*
000452 ** Compute and return a new Expr object which when passed to
000453 ** sqlite3ExprCode() will generate all necessary code to compute
000454 ** the iField-th column of the vector expression pVector.
000455 **
000456 ** It is ok for pVector to be a scalar (as long as iField==0).
000457 ** In that case, this routine works like sqlite3ExprDup().
000458 **
000459 ** The caller owns the returned Expr object and is responsible for
000460 ** ensuring that the returned value eventually gets freed.
000461 **
000462 ** The caller retains ownership of pVector. If pVector is a TK_SELECT,
000463 ** then the returned object will reference pVector and so pVector must remain
000464 ** valid for the life of the returned object. If pVector is a TK_VECTOR
000465 ** or a scalar expression, then it can be deleted as soon as this routine
000466 ** returns.
000467 **
000468 ** A trick to cause a TK_SELECT pVector to be deleted together with
000469 ** the returned Expr object is to attach the pVector to the pRight field
000470 ** of the returned TK_SELECT_COLUMN Expr object.
000471 */
000472 Expr *sqlite3ExprForVectorField(
000473 Parse *pParse, /* Parsing context */
000474 Expr *pVector, /* The vector. List of expressions or a sub-SELECT */
000475 int iField /* Which column of the vector to return */
000476 ){
000477 Expr *pRet;
000478 if( pVector->op==TK_SELECT ){
000479 assert( pVector->flags & EP_xIsSelect );
000480 /* The TK_SELECT_COLUMN Expr node:
000481 **
000482 ** pLeft: pVector containing TK_SELECT. Not deleted.
000483 ** pRight: not used. But recursively deleted.
000484 ** iColumn: Index of a column in pVector
000485 ** iTable: 0 or the number of columns on the LHS of an assignment
000486 ** pLeft->iTable: First in an array of register holding result, or 0
000487 ** if the result is not yet computed.
000488 **
000489 ** sqlite3ExprDelete() specifically skips the recursive delete of
000490 ** pLeft on TK_SELECT_COLUMN nodes. But pRight is followed, so pVector
000491 ** can be attached to pRight to cause this node to take ownership of
000492 ** pVector. Typically there will be multiple TK_SELECT_COLUMN nodes
000493 ** with the same pLeft pointer to the pVector, but only one of them
000494 ** will own the pVector.
000495 */
000496 pRet = sqlite3PExpr(pParse, TK_SELECT_COLUMN, 0, 0);
000497 if( pRet ){
000498 pRet->iColumn = iField;
000499 pRet->pLeft = pVector;
000500 }
000501 assert( pRet==0 || pRet->iTable==0 );
000502 }else{
000503 if( pVector->op==TK_VECTOR ) pVector = pVector->x.pList->a[iField].pExpr;
000504 pRet = sqlite3ExprDup(pParse->db, pVector, 0);
000505 sqlite3RenameTokenRemap(pParse, pRet, pVector);
000506 }
000507 return pRet;
000508 }
000509
000510 /*
000511 ** If expression pExpr is of type TK_SELECT, generate code to evaluate
000512 ** it. Return the register in which the result is stored (or, if the
000513 ** sub-select returns more than one column, the first in an array
000514 ** of registers in which the result is stored).
000515 **
000516 ** If pExpr is not a TK_SELECT expression, return 0.
000517 */
000518 static int exprCodeSubselect(Parse *pParse, Expr *pExpr){
000519 int reg = 0;
000520 #ifndef SQLITE_OMIT_SUBQUERY
000521 if( pExpr->op==TK_SELECT ){
000522 reg = sqlite3CodeSubselect(pParse, pExpr);
000523 }
000524 #endif
000525 return reg;
000526 }
000527
000528 /*
000529 ** Argument pVector points to a vector expression - either a TK_VECTOR
000530 ** or TK_SELECT that returns more than one column. This function returns
000531 ** the register number of a register that contains the value of
000532 ** element iField of the vector.
000533 **
000534 ** If pVector is a TK_SELECT expression, then code for it must have
000535 ** already been generated using the exprCodeSubselect() routine. In this
000536 ** case parameter regSelect should be the first in an array of registers
000537 ** containing the results of the sub-select.
000538 **
000539 ** If pVector is of type TK_VECTOR, then code for the requested field
000540 ** is generated. In this case (*pRegFree) may be set to the number of
000541 ** a temporary register to be freed by the caller before returning.
000542 **
000543 ** Before returning, output parameter (*ppExpr) is set to point to the
000544 ** Expr object corresponding to element iElem of the vector.
000545 */
000546 static int exprVectorRegister(
000547 Parse *pParse, /* Parse context */
000548 Expr *pVector, /* Vector to extract element from */
000549 int iField, /* Field to extract from pVector */
000550 int regSelect, /* First in array of registers */
000551 Expr **ppExpr, /* OUT: Expression element */
000552 int *pRegFree /* OUT: Temp register to free */
000553 ){
000554 u8 op = pVector->op;
000555 assert( op==TK_VECTOR || op==TK_REGISTER || op==TK_SELECT );
000556 if( op==TK_REGISTER ){
000557 *ppExpr = sqlite3VectorFieldSubexpr(pVector, iField);
000558 return pVector->iTable+iField;
000559 }
000560 if( op==TK_SELECT ){
000561 *ppExpr = pVector->x.pSelect->pEList->a[iField].pExpr;
000562 return regSelect+iField;
000563 }
000564 *ppExpr = pVector->x.pList->a[iField].pExpr;
000565 return sqlite3ExprCodeTemp(pParse, *ppExpr, pRegFree);
000566 }
000567
000568 /*
000569 ** Expression pExpr is a comparison between two vector values. Compute
000570 ** the result of the comparison (1, 0, or NULL) and write that
000571 ** result into register dest.
000572 **
000573 ** The caller must satisfy the following preconditions:
000574 **
000575 ** if pExpr->op==TK_IS: op==TK_EQ and p5==SQLITE_NULLEQ
000576 ** if pExpr->op==TK_ISNOT: op==TK_NE and p5==SQLITE_NULLEQ
000577 ** otherwise: op==pExpr->op and p5==0
000578 */
000579 static void codeVectorCompare(
000580 Parse *pParse, /* Code generator context */
000581 Expr *pExpr, /* The comparison operation */
000582 int dest, /* Write results into this register */
000583 u8 op, /* Comparison operator */
000584 u8 p5 /* SQLITE_NULLEQ or zero */
000585 ){
000586 Vdbe *v = pParse->pVdbe;
000587 Expr *pLeft = pExpr->pLeft;
000588 Expr *pRight = pExpr->pRight;
000589 int nLeft = sqlite3ExprVectorSize(pLeft);
000590 int i;
000591 int regLeft = 0;
000592 int regRight = 0;
000593 u8 opx = op;
000594 int addrDone = sqlite3VdbeMakeLabel(pParse);
000595 int isCommuted = ExprHasProperty(pExpr,EP_Commuted);
000596
000597 if( pParse->nErr ) return;
000598 if( nLeft!=sqlite3ExprVectorSize(pRight) ){
000599 sqlite3ErrorMsg(pParse, "row value misused");
000600 return;
000601 }
000602 assert( pExpr->op==TK_EQ || pExpr->op==TK_NE
000603 || pExpr->op==TK_IS || pExpr->op==TK_ISNOT
000604 || pExpr->op==TK_LT || pExpr->op==TK_GT
000605 || pExpr->op==TK_LE || pExpr->op==TK_GE
000606 );
000607 assert( pExpr->op==op || (pExpr->op==TK_IS && op==TK_EQ)
000608 || (pExpr->op==TK_ISNOT && op==TK_NE) );
000609 assert( p5==0 || pExpr->op!=op );
000610 assert( p5==SQLITE_NULLEQ || pExpr->op==op );
000611
000612 p5 |= SQLITE_STOREP2;
000613 if( opx==TK_LE ) opx = TK_LT;
000614 if( opx==TK_GE ) opx = TK_GT;
000615
000616 regLeft = exprCodeSubselect(pParse, pLeft);
000617 regRight = exprCodeSubselect(pParse, pRight);
000618
000619 for(i=0; 1 /*Loop exits by "break"*/; i++){
000620 int regFree1 = 0, regFree2 = 0;
000621 Expr *pL, *pR;
000622 int r1, r2;
000623 assert( i>=0 && i<nLeft );
000624 r1 = exprVectorRegister(pParse, pLeft, i, regLeft, &pL, ®Free1);
000625 r2 = exprVectorRegister(pParse, pRight, i, regRight, &pR, ®Free2);
000626 codeCompare(pParse, pL, pR, opx, r1, r2, dest, p5, isCommuted);
000627 testcase(op==OP_Lt); VdbeCoverageIf(v,op==OP_Lt);
000628 testcase(op==OP_Le); VdbeCoverageIf(v,op==OP_Le);
000629 testcase(op==OP_Gt); VdbeCoverageIf(v,op==OP_Gt);
000630 testcase(op==OP_Ge); VdbeCoverageIf(v,op==OP_Ge);
000631 testcase(op==OP_Eq); VdbeCoverageIf(v,op==OP_Eq);
000632 testcase(op==OP_Ne); VdbeCoverageIf(v,op==OP_Ne);
000633 sqlite3ReleaseTempReg(pParse, regFree1);
000634 sqlite3ReleaseTempReg(pParse, regFree2);
000635 if( i==nLeft-1 ){
000636 break;
000637 }
000638 if( opx==TK_EQ ){
000639 sqlite3VdbeAddOp2(v, OP_IfNot, dest, addrDone); VdbeCoverage(v);
000640 p5 |= SQLITE_KEEPNULL;
000641 }else if( opx==TK_NE ){
000642 sqlite3VdbeAddOp2(v, OP_If, dest, addrDone); VdbeCoverage(v);
000643 p5 |= SQLITE_KEEPNULL;
000644 }else{
000645 assert( op==TK_LT || op==TK_GT || op==TK_LE || op==TK_GE );
000646 sqlite3VdbeAddOp2(v, OP_ElseNotEq, 0, addrDone);
000647 VdbeCoverageIf(v, op==TK_LT);
000648 VdbeCoverageIf(v, op==TK_GT);
000649 VdbeCoverageIf(v, op==TK_LE);
000650 VdbeCoverageIf(v, op==TK_GE);
000651 if( i==nLeft-2 ) opx = op;
000652 }
000653 }
000654 sqlite3VdbeResolveLabel(v, addrDone);
000655 }
000656
000657 #if SQLITE_MAX_EXPR_DEPTH>0
000658 /*
000659 ** Check that argument nHeight is less than or equal to the maximum
000660 ** expression depth allowed. If it is not, leave an error message in
000661 ** pParse.
000662 */
000663 int sqlite3ExprCheckHeight(Parse *pParse, int nHeight){
000664 int rc = SQLITE_OK;
000665 int mxHeight = pParse->db->aLimit[SQLITE_LIMIT_EXPR_DEPTH];
000666 if( nHeight>mxHeight ){
000667 sqlite3ErrorMsg(pParse,
000668 "Expression tree is too large (maximum depth %d)", mxHeight
000669 );
000670 rc = SQLITE_ERROR;
000671 }
000672 return rc;
000673 }
000674
000675 /* The following three functions, heightOfExpr(), heightOfExprList()
000676 ** and heightOfSelect(), are used to determine the maximum height
000677 ** of any expression tree referenced by the structure passed as the
000678 ** first argument.
000679 **
000680 ** If this maximum height is greater than the current value pointed
000681 ** to by pnHeight, the second parameter, then set *pnHeight to that
000682 ** value.
000683 */
000684 static void heightOfExpr(Expr *p, int *pnHeight){
000685 if( p ){
000686 if( p->nHeight>*pnHeight ){
000687 *pnHeight = p->nHeight;
000688 }
000689 }
000690 }
000691 static void heightOfExprList(ExprList *p, int *pnHeight){
000692 if( p ){
000693 int i;
000694 for(i=0; i<p->nExpr; i++){
000695 heightOfExpr(p->a[i].pExpr, pnHeight);
000696 }
000697 }
000698 }
000699 static void heightOfSelect(Select *pSelect, int *pnHeight){
000700 Select *p;
000701 for(p=pSelect; p; p=p->pPrior){
000702 heightOfExpr(p->pWhere, pnHeight);
000703 heightOfExpr(p->pHaving, pnHeight);
000704 heightOfExpr(p->pLimit, pnHeight);
000705 heightOfExprList(p->pEList, pnHeight);
000706 heightOfExprList(p->pGroupBy, pnHeight);
000707 heightOfExprList(p->pOrderBy, pnHeight);
000708 }
000709 }
000710
000711 /*
000712 ** Set the Expr.nHeight variable in the structure passed as an
000713 ** argument. An expression with no children, Expr.pList or
000714 ** Expr.pSelect member has a height of 1. Any other expression
000715 ** has a height equal to the maximum height of any other
000716 ** referenced Expr plus one.
000717 **
000718 ** Also propagate EP_Propagate flags up from Expr.x.pList to Expr.flags,
000719 ** if appropriate.
000720 */
000721 static void exprSetHeight(Expr *p){
000722 int nHeight = 0;
000723 heightOfExpr(p->pLeft, &nHeight);
000724 heightOfExpr(p->pRight, &nHeight);
000725 if( ExprHasProperty(p, EP_xIsSelect) ){
000726 heightOfSelect(p->x.pSelect, &nHeight);
000727 }else if( p->x.pList ){
000728 heightOfExprList(p->x.pList, &nHeight);
000729 p->flags |= EP_Propagate & sqlite3ExprListFlags(p->x.pList);
000730 }
000731 p->nHeight = nHeight + 1;
000732 }
000733
000734 /*
000735 ** Set the Expr.nHeight variable using the exprSetHeight() function. If
000736 ** the height is greater than the maximum allowed expression depth,
000737 ** leave an error in pParse.
000738 **
000739 ** Also propagate all EP_Propagate flags from the Expr.x.pList into
000740 ** Expr.flags.
000741 */
000742 void sqlite3ExprSetHeightAndFlags(Parse *pParse, Expr *p){
000743 if( pParse->nErr ) return;
000744 exprSetHeight(p);
000745 sqlite3ExprCheckHeight(pParse, p->nHeight);
000746 }
000747
000748 /*
000749 ** Return the maximum height of any expression tree referenced
000750 ** by the select statement passed as an argument.
000751 */
000752 int sqlite3SelectExprHeight(Select *p){
000753 int nHeight = 0;
000754 heightOfSelect(p, &nHeight);
000755 return nHeight;
000756 }
000757 #else /* ABOVE: Height enforcement enabled. BELOW: Height enforcement off */
000758 /*
000759 ** Propagate all EP_Propagate flags from the Expr.x.pList into
000760 ** Expr.flags.
000761 */
000762 void sqlite3ExprSetHeightAndFlags(Parse *pParse, Expr *p){
000763 if( p && p->x.pList && !ExprHasProperty(p, EP_xIsSelect) ){
000764 p->flags |= EP_Propagate & sqlite3ExprListFlags(p->x.pList);
000765 }
000766 }
000767 #define exprSetHeight(y)
000768 #endif /* SQLITE_MAX_EXPR_DEPTH>0 */
000769
000770 /*
000771 ** This routine is the core allocator for Expr nodes.
000772 **
000773 ** Construct a new expression node and return a pointer to it. Memory
000774 ** for this node and for the pToken argument is a single allocation
000775 ** obtained from sqlite3DbMalloc(). The calling function
000776 ** is responsible for making sure the node eventually gets freed.
000777 **
000778 ** If dequote is true, then the token (if it exists) is dequoted.
000779 ** If dequote is false, no dequoting is performed. The deQuote
000780 ** parameter is ignored if pToken is NULL or if the token does not
000781 ** appear to be quoted. If the quotes were of the form "..." (double-quotes)
000782 ** then the EP_DblQuoted flag is set on the expression node.
000783 **
000784 ** Special case: If op==TK_INTEGER and pToken points to a string that
000785 ** can be translated into a 32-bit integer, then the token is not
000786 ** stored in u.zToken. Instead, the integer values is written
000787 ** into u.iValue and the EP_IntValue flag is set. No extra storage
000788 ** is allocated to hold the integer text and the dequote flag is ignored.
000789 */
000790 Expr *sqlite3ExprAlloc(
000791 sqlite3 *db, /* Handle for sqlite3DbMallocRawNN() */
000792 int op, /* Expression opcode */
000793 const Token *pToken, /* Token argument. Might be NULL */
000794 int dequote /* True to dequote */
000795 ){
000796 Expr *pNew;
000797 int nExtra = 0;
000798 int iValue = 0;
000799
000800 assert( db!=0 );
000801 if( pToken ){
000802 if( op!=TK_INTEGER || pToken->z==0
000803 || sqlite3GetInt32(pToken->z, &iValue)==0 ){
000804 nExtra = pToken->n+1;
000805 assert( iValue>=0 );
000806 }
000807 }
000808 pNew = sqlite3DbMallocRawNN(db, sizeof(Expr)+nExtra);
000809 if( pNew ){
000810 memset(pNew, 0, sizeof(Expr));
000811 pNew->op = (u8)op;
000812 pNew->iAgg = -1;
000813 if( pToken ){
000814 if( nExtra==0 ){
000815 pNew->flags |= EP_IntValue|EP_Leaf|(iValue?EP_IsTrue:EP_IsFalse);
000816 pNew->u.iValue = iValue;
000817 }else{
000818 pNew->u.zToken = (char*)&pNew[1];
000819 assert( pToken->z!=0 || pToken->n==0 );
000820 if( pToken->n ) memcpy(pNew->u.zToken, pToken->z, pToken->n);
000821 pNew->u.zToken[pToken->n] = 0;
000822 if( dequote && sqlite3Isquote(pNew->u.zToken[0]) ){
000823 sqlite3DequoteExpr(pNew);
000824 }
000825 }
000826 }
000827 #if SQLITE_MAX_EXPR_DEPTH>0
000828 pNew->nHeight = 1;
000829 #endif
000830 }
000831 return pNew;
000832 }
000833
000834 /*
000835 ** Allocate a new expression node from a zero-terminated token that has
000836 ** already been dequoted.
000837 */
000838 Expr *sqlite3Expr(
000839 sqlite3 *db, /* Handle for sqlite3DbMallocZero() (may be null) */
000840 int op, /* Expression opcode */
000841 const char *zToken /* Token argument. Might be NULL */
000842 ){
000843 Token x;
000844 x.z = zToken;
000845 x.n = sqlite3Strlen30(zToken);
000846 return sqlite3ExprAlloc(db, op, &x, 0);
000847 }
000848
000849 /*
000850 ** Attach subtrees pLeft and pRight to the Expr node pRoot.
000851 **
000852 ** If pRoot==NULL that means that a memory allocation error has occurred.
000853 ** In that case, delete the subtrees pLeft and pRight.
000854 */
000855 void sqlite3ExprAttachSubtrees(
000856 sqlite3 *db,
000857 Expr *pRoot,
000858 Expr *pLeft,
000859 Expr *pRight
000860 ){
000861 if( pRoot==0 ){
000862 assert( db->mallocFailed );
000863 sqlite3ExprDelete(db, pLeft);
000864 sqlite3ExprDelete(db, pRight);
000865 }else{
000866 if( pRight ){
000867 pRoot->pRight = pRight;
000868 pRoot->flags |= EP_Propagate & pRight->flags;
000869 }
000870 if( pLeft ){
000871 pRoot->pLeft = pLeft;
000872 pRoot->flags |= EP_Propagate & pLeft->flags;
000873 }
000874 exprSetHeight(pRoot);
000875 }
000876 }
000877
000878 /*
000879 ** Allocate an Expr node which joins as many as two subtrees.
000880 **
000881 ** One or both of the subtrees can be NULL. Return a pointer to the new
000882 ** Expr node. Or, if an OOM error occurs, set pParse->db->mallocFailed,
000883 ** free the subtrees and return NULL.
000884 */
000885 Expr *sqlite3PExpr(
000886 Parse *pParse, /* Parsing context */
000887 int op, /* Expression opcode */
000888 Expr *pLeft, /* Left operand */
000889 Expr *pRight /* Right operand */
000890 ){
000891 Expr *p;
000892 p = sqlite3DbMallocRawNN(pParse->db, sizeof(Expr));
000893 if( p ){
000894 memset(p, 0, sizeof(Expr));
000895 p->op = op & 0xff;
000896 p->iAgg = -1;
000897 sqlite3ExprAttachSubtrees(pParse->db, p, pLeft, pRight);
000898 sqlite3ExprCheckHeight(pParse, p->nHeight);
000899 }else{
000900 sqlite3ExprDelete(pParse->db, pLeft);
000901 sqlite3ExprDelete(pParse->db, pRight);
000902 }
000903 return p;
000904 }
000905
000906 /*
000907 ** Add pSelect to the Expr.x.pSelect field. Or, if pExpr is NULL (due
000908 ** do a memory allocation failure) then delete the pSelect object.
000909 */
000910 void sqlite3PExprAddSelect(Parse *pParse, Expr *pExpr, Select *pSelect){
000911 if( pExpr ){
000912 pExpr->x.pSelect = pSelect;
000913 ExprSetProperty(pExpr, EP_xIsSelect|EP_Subquery);
000914 sqlite3ExprSetHeightAndFlags(pParse, pExpr);
000915 }else{
000916 assert( pParse->db->mallocFailed );
000917 sqlite3SelectDelete(pParse->db, pSelect);
000918 }
000919 }
000920
000921
000922 /*
000923 ** Join two expressions using an AND operator. If either expression is
000924 ** NULL, then just return the other expression.
000925 **
000926 ** If one side or the other of the AND is known to be false, then instead
000927 ** of returning an AND expression, just return a constant expression with
000928 ** a value of false.
000929 */
000930 Expr *sqlite3ExprAnd(Parse *pParse, Expr *pLeft, Expr *pRight){
000931 sqlite3 *db = pParse->db;
000932 if( pLeft==0 ){
000933 return pRight;
000934 }else if( pRight==0 ){
000935 return pLeft;
000936 }else if( ExprAlwaysFalse(pLeft) || ExprAlwaysFalse(pRight) ){
000937 sqlite3ExprUnmapAndDelete(pParse, pLeft);
000938 sqlite3ExprUnmapAndDelete(pParse, pRight);
000939 return sqlite3Expr(db, TK_INTEGER, "0");
000940 }else{
000941 return sqlite3PExpr(pParse, TK_AND, pLeft, pRight);
000942 }
000943 }
000944
000945 /*
000946 ** Construct a new expression node for a function with multiple
000947 ** arguments.
000948 */
000949 Expr *sqlite3ExprFunction(
000950 Parse *pParse, /* Parsing context */
000951 ExprList *pList, /* Argument list */
000952 Token *pToken, /* Name of the function */
000953 int eDistinct /* SF_Distinct or SF_ALL or 0 */
000954 ){
000955 Expr *pNew;
000956 sqlite3 *db = pParse->db;
000957 assert( pToken );
000958 pNew = sqlite3ExprAlloc(db, TK_FUNCTION, pToken, 1);
000959 if( pNew==0 ){
000960 sqlite3ExprListDelete(db, pList); /* Avoid memory leak when malloc fails */
000961 return 0;
000962 }
000963 if( pList && pList->nExpr > pParse->db->aLimit[SQLITE_LIMIT_FUNCTION_ARG] ){
000964 sqlite3ErrorMsg(pParse, "too many arguments on function %T", pToken);
000965 }
000966 pNew->x.pList = pList;
000967 ExprSetProperty(pNew, EP_HasFunc);
000968 assert( !ExprHasProperty(pNew, EP_xIsSelect) );
000969 sqlite3ExprSetHeightAndFlags(pParse, pNew);
000970 if( eDistinct==SF_Distinct ) ExprSetProperty(pNew, EP_Distinct);
000971 return pNew;
000972 }
000973
000974 /*
000975 ** Assign a variable number to an expression that encodes a wildcard
000976 ** in the original SQL statement.
000977 **
000978 ** Wildcards consisting of a single "?" are assigned the next sequential
000979 ** variable number.
000980 **
000981 ** Wildcards of the form "?nnn" are assigned the number "nnn". We make
000982 ** sure "nnn" is not too big to avoid a denial of service attack when
000983 ** the SQL statement comes from an external source.
000984 **
000985 ** Wildcards of the form ":aaa", "@aaa", or "$aaa" are assigned the same number
000986 ** as the previous instance of the same wildcard. Or if this is the first
000987 ** instance of the wildcard, the next sequential variable number is
000988 ** assigned.
000989 */
000990 void sqlite3ExprAssignVarNumber(Parse *pParse, Expr *pExpr, u32 n){
000991 sqlite3 *db = pParse->db;
000992 const char *z;
000993 ynVar x;
000994
000995 if( pExpr==0 ) return;
000996 assert( !ExprHasProperty(pExpr, EP_IntValue|EP_Reduced|EP_TokenOnly) );
000997 z = pExpr->u.zToken;
000998 assert( z!=0 );
000999 assert( z[0]!=0 );
001000 assert( n==(u32)sqlite3Strlen30(z) );
001001 if( z[1]==0 ){
001002 /* Wildcard of the form "?". Assign the next variable number */
001003 assert( z[0]=='?' );
001004 x = (ynVar)(++pParse->nVar);
001005 }else{
001006 int doAdd = 0;
001007 if( z[0]=='?' ){
001008 /* Wildcard of the form "?nnn". Convert "nnn" to an integer and
001009 ** use it as the variable number */
001010 i64 i;
001011 int bOk;
001012 if( n==2 ){ /*OPTIMIZATION-IF-TRUE*/
001013 i = z[1]-'0'; /* The common case of ?N for a single digit N */
001014 bOk = 1;
001015 }else{
001016 bOk = 0==sqlite3Atoi64(&z[1], &i, n-1, SQLITE_UTF8);
001017 }
001018 testcase( i==0 );
001019 testcase( i==1 );
001020 testcase( i==db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER]-1 );
001021 testcase( i==db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER] );
001022 if( bOk==0 || i<1 || i>db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER] ){
001023 sqlite3ErrorMsg(pParse, "variable number must be between ?1 and ?%d",
001024 db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER]);
001025 return;
001026 }
001027 x = (ynVar)i;
001028 if( x>pParse->nVar ){
001029 pParse->nVar = (int)x;
001030 doAdd = 1;
001031 }else if( sqlite3VListNumToName(pParse->pVList, x)==0 ){
001032 doAdd = 1;
001033 }
001034 }else{
001035 /* Wildcards like ":aaa", "$aaa" or "@aaa". Reuse the same variable
001036 ** number as the prior appearance of the same name, or if the name
001037 ** has never appeared before, reuse the same variable number
001038 */
001039 x = (ynVar)sqlite3VListNameToNum(pParse->pVList, z, n);
001040 if( x==0 ){
001041 x = (ynVar)(++pParse->nVar);
001042 doAdd = 1;
001043 }
001044 }
001045 if( doAdd ){
001046 pParse->pVList = sqlite3VListAdd(db, pParse->pVList, z, n, x);
001047 }
001048 }
001049 pExpr->iColumn = x;
001050 if( x>db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER] ){
001051 sqlite3ErrorMsg(pParse, "too many SQL variables");
001052 }
001053 }
001054
001055 /*
001056 ** Recursively delete an expression tree.
001057 */
001058 static SQLITE_NOINLINE void sqlite3ExprDeleteNN(sqlite3 *db, Expr *p){
001059 assert( p!=0 );
001060 /* Sanity check: Assert that the IntValue is non-negative if it exists */
001061 assert( !ExprHasProperty(p, EP_IntValue) || p->u.iValue>=0 );
001062
001063 assert( !ExprHasProperty(p, EP_WinFunc) || p->y.pWin!=0 || db->mallocFailed );
001064 assert( p->op!=TK_FUNCTION || ExprHasProperty(p, EP_TokenOnly|EP_Reduced)
001065 || p->y.pWin==0 || ExprHasProperty(p, EP_WinFunc) );
001066 #ifdef SQLITE_DEBUG
001067 if( ExprHasProperty(p, EP_Leaf) && !ExprHasProperty(p, EP_TokenOnly) ){
001068 assert( p->pLeft==0 );
001069 assert( p->pRight==0 );
001070 assert( p->x.pSelect==0 );
001071 }
001072 #endif
001073 if( !ExprHasProperty(p, (EP_TokenOnly|EP_Leaf)) ){
001074 /* The Expr.x union is never used at the same time as Expr.pRight */
001075 assert( p->x.pList==0 || p->pRight==0 );
001076 if( p->pLeft && p->op!=TK_SELECT_COLUMN ) sqlite3ExprDeleteNN(db, p->pLeft);
001077 if( p->pRight ){
001078 assert( !ExprHasProperty(p, EP_WinFunc) );
001079 sqlite3ExprDeleteNN(db, p->pRight);
001080 }else if( ExprHasProperty(p, EP_xIsSelect) ){
001081 assert( !ExprHasProperty(p, EP_WinFunc) );
001082 sqlite3SelectDelete(db, p->x.pSelect);
001083 }else{
001084 sqlite3ExprListDelete(db, p->x.pList);
001085 #ifndef SQLITE_OMIT_WINDOWFUNC
001086 if( ExprHasProperty(p, EP_WinFunc) ){
001087 sqlite3WindowDelete(db, p->y.pWin);
001088 }
001089 #endif
001090 }
001091 }
001092 if( ExprHasProperty(p, EP_MemToken) ) sqlite3DbFree(db, p->u.zToken);
001093 if( !ExprHasProperty(p, EP_Static) ){
001094 sqlite3DbFreeNN(db, p);
001095 }
001096 }
001097 void sqlite3ExprDelete(sqlite3 *db, Expr *p){
001098 if( p ) sqlite3ExprDeleteNN(db, p);
001099 }
001100
001101 /* Invoke sqlite3RenameExprUnmap() and sqlite3ExprDelete() on the
001102 ** expression.
001103 */
001104 void sqlite3ExprUnmapAndDelete(Parse *pParse, Expr *p){
001105 if( p ){
001106 if( IN_RENAME_OBJECT ){
001107 sqlite3RenameExprUnmap(pParse, p);
001108 }
001109 sqlite3ExprDeleteNN(pParse->db, p);
001110 }
001111 }
001112
001113 /*
001114 ** Return the number of bytes allocated for the expression structure
001115 ** passed as the first argument. This is always one of EXPR_FULLSIZE,
001116 ** EXPR_REDUCEDSIZE or EXPR_TOKENONLYSIZE.
001117 */
001118 static int exprStructSize(Expr *p){
001119 if( ExprHasProperty(p, EP_TokenOnly) ) return EXPR_TOKENONLYSIZE;
001120 if( ExprHasProperty(p, EP_Reduced) ) return EXPR_REDUCEDSIZE;
001121 return EXPR_FULLSIZE;
001122 }
001123
001124 /*
001125 ** The dupedExpr*Size() routines each return the number of bytes required
001126 ** to store a copy of an expression or expression tree. They differ in
001127 ** how much of the tree is measured.
001128 **
001129 ** dupedExprStructSize() Size of only the Expr structure
001130 ** dupedExprNodeSize() Size of Expr + space for token
001131 ** dupedExprSize() Expr + token + subtree components
001132 **
001133 ***************************************************************************
001134 **
001135 ** The dupedExprStructSize() function returns two values OR-ed together:
001136 ** (1) the space required for a copy of the Expr structure only and
001137 ** (2) the EP_xxx flags that indicate what the structure size should be.
001138 ** The return values is always one of:
001139 **
001140 ** EXPR_FULLSIZE
001141 ** EXPR_REDUCEDSIZE | EP_Reduced
001142 ** EXPR_TOKENONLYSIZE | EP_TokenOnly
001143 **
001144 ** The size of the structure can be found by masking the return value
001145 ** of this routine with 0xfff. The flags can be found by masking the
001146 ** return value with EP_Reduced|EP_TokenOnly.
001147 **
001148 ** Note that with flags==EXPRDUP_REDUCE, this routines works on full-size
001149 ** (unreduced) Expr objects as they or originally constructed by the parser.
001150 ** During expression analysis, extra information is computed and moved into
001151 ** later parts of the Expr object and that extra information might get chopped
001152 ** off if the expression is reduced. Note also that it does not work to
001153 ** make an EXPRDUP_REDUCE copy of a reduced expression. It is only legal
001154 ** to reduce a pristine expression tree from the parser. The implementation
001155 ** of dupedExprStructSize() contain multiple assert() statements that attempt
001156 ** to enforce this constraint.
001157 */
001158 static int dupedExprStructSize(Expr *p, int flags){
001159 int nSize;
001160 assert( flags==EXPRDUP_REDUCE || flags==0 ); /* Only one flag value allowed */
001161 assert( EXPR_FULLSIZE<=0xfff );
001162 assert( (0xfff & (EP_Reduced|EP_TokenOnly))==0 );
001163 if( 0==flags || p->op==TK_SELECT_COLUMN
001164 #ifndef SQLITE_OMIT_WINDOWFUNC
001165 || ExprHasProperty(p, EP_WinFunc)
001166 #endif
001167 ){
001168 nSize = EXPR_FULLSIZE;
001169 }else{
001170 assert( !ExprHasProperty(p, EP_TokenOnly|EP_Reduced) );
001171 assert( !ExprHasProperty(p, EP_FromJoin) );
001172 assert( !ExprHasProperty(p, EP_MemToken) );
001173 assert( !ExprHasProperty(p, EP_NoReduce) );
001174 if( p->pLeft || p->x.pList ){
001175 nSize = EXPR_REDUCEDSIZE | EP_Reduced;
001176 }else{
001177 assert( p->pRight==0 );
001178 nSize = EXPR_TOKENONLYSIZE | EP_TokenOnly;
001179 }
001180 }
001181 return nSize;
001182 }
001183
001184 /*
001185 ** This function returns the space in bytes required to store the copy
001186 ** of the Expr structure and a copy of the Expr.u.zToken string (if that
001187 ** string is defined.)
001188 */
001189 static int dupedExprNodeSize(Expr *p, int flags){
001190 int nByte = dupedExprStructSize(p, flags) & 0xfff;
001191 if( !ExprHasProperty(p, EP_IntValue) && p->u.zToken ){
001192 nByte += sqlite3Strlen30NN(p->u.zToken)+1;
001193 }
001194 return ROUND8(nByte);
001195 }
001196
001197 /*
001198 ** Return the number of bytes required to create a duplicate of the
001199 ** expression passed as the first argument. The second argument is a
001200 ** mask containing EXPRDUP_XXX flags.
001201 **
001202 ** The value returned includes space to create a copy of the Expr struct
001203 ** itself and the buffer referred to by Expr.u.zToken, if any.
001204 **
001205 ** If the EXPRDUP_REDUCE flag is set, then the return value includes
001206 ** space to duplicate all Expr nodes in the tree formed by Expr.pLeft
001207 ** and Expr.pRight variables (but not for any structures pointed to or
001208 ** descended from the Expr.x.pList or Expr.x.pSelect variables).
001209 */
001210 static int dupedExprSize(Expr *p, int flags){
001211 int nByte = 0;
001212 if( p ){
001213 nByte = dupedExprNodeSize(p, flags);
001214 if( flags&EXPRDUP_REDUCE ){
001215 nByte += dupedExprSize(p->pLeft, flags) + dupedExprSize(p->pRight, flags);
001216 }
001217 }
001218 return nByte;
001219 }
001220
001221 /*
001222 ** This function is similar to sqlite3ExprDup(), except that if pzBuffer
001223 ** is not NULL then *pzBuffer is assumed to point to a buffer large enough
001224 ** to store the copy of expression p, the copies of p->u.zToken
001225 ** (if applicable), and the copies of the p->pLeft and p->pRight expressions,
001226 ** if any. Before returning, *pzBuffer is set to the first byte past the
001227 ** portion of the buffer copied into by this function.
001228 */
001229 static Expr *exprDup(sqlite3 *db, Expr *p, int dupFlags, u8 **pzBuffer){
001230 Expr *pNew; /* Value to return */
001231 u8 *zAlloc; /* Memory space from which to build Expr object */
001232 u32 staticFlag; /* EP_Static if space not obtained from malloc */
001233
001234 assert( db!=0 );
001235 assert( p );
001236 assert( dupFlags==0 || dupFlags==EXPRDUP_REDUCE );
001237 assert( pzBuffer==0 || dupFlags==EXPRDUP_REDUCE );
001238
001239 /* Figure out where to write the new Expr structure. */
001240 if( pzBuffer ){
001241 zAlloc = *pzBuffer;
001242 staticFlag = EP_Static;
001243 }else{
001244 zAlloc = sqlite3DbMallocRawNN(db, dupedExprSize(p, dupFlags));
001245 staticFlag = 0;
001246 }
001247 pNew = (Expr *)zAlloc;
001248
001249 if( pNew ){
001250 /* Set nNewSize to the size allocated for the structure pointed to
001251 ** by pNew. This is either EXPR_FULLSIZE, EXPR_REDUCEDSIZE or
001252 ** EXPR_TOKENONLYSIZE. nToken is set to the number of bytes consumed
001253 ** by the copy of the p->u.zToken string (if any).
001254 */
001255 const unsigned nStructSize = dupedExprStructSize(p, dupFlags);
001256 const int nNewSize = nStructSize & 0xfff;
001257 int nToken;
001258 if( !ExprHasProperty(p, EP_IntValue) && p->u.zToken ){
001259 nToken = sqlite3Strlen30(p->u.zToken) + 1;
001260 }else{
001261 nToken = 0;
001262 }
001263 if( dupFlags ){
001264 assert( ExprHasProperty(p, EP_Reduced)==0 );
001265 memcpy(zAlloc, p, nNewSize);
001266 }else{
001267 u32 nSize = (u32)exprStructSize(p);
001268 memcpy(zAlloc, p, nSize);
001269 if( nSize<EXPR_FULLSIZE ){
001270 memset(&zAlloc[nSize], 0, EXPR_FULLSIZE-nSize);
001271 }
001272 }
001273
001274 /* Set the EP_Reduced, EP_TokenOnly, and EP_Static flags appropriately. */
001275 pNew->flags &= ~(EP_Reduced|EP_TokenOnly|EP_Static|EP_MemToken);
001276 pNew->flags |= nStructSize & (EP_Reduced|EP_TokenOnly);
001277 pNew->flags |= staticFlag;
001278
001279 /* Copy the p->u.zToken string, if any. */
001280 if( nToken ){
001281 char *zToken = pNew->u.zToken = (char*)&zAlloc[nNewSize];
001282 memcpy(zToken, p->u.zToken, nToken);
001283 }
001284
001285 if( 0==((p->flags|pNew->flags) & (EP_TokenOnly|EP_Leaf)) ){
001286 /* Fill in the pNew->x.pSelect or pNew->x.pList member. */
001287 if( ExprHasProperty(p, EP_xIsSelect) ){
001288 pNew->x.pSelect = sqlite3SelectDup(db, p->x.pSelect, dupFlags);
001289 }else{
001290 pNew->x.pList = sqlite3ExprListDup(db, p->x.pList, dupFlags);
001291 }
001292 }
001293
001294 /* Fill in pNew->pLeft and pNew->pRight. */
001295 if( ExprHasProperty(pNew, EP_Reduced|EP_TokenOnly|EP_WinFunc) ){
001296 zAlloc += dupedExprNodeSize(p, dupFlags);
001297 if( !ExprHasProperty(pNew, EP_TokenOnly|EP_Leaf) ){
001298 pNew->pLeft = p->pLeft ?
001299 exprDup(db, p->pLeft, EXPRDUP_REDUCE, &zAlloc) : 0;
001300 pNew->pRight = p->pRight ?
001301 exprDup(db, p->pRight, EXPRDUP_REDUCE, &zAlloc) : 0;
001302 }
001303 #ifndef SQLITE_OMIT_WINDOWFUNC
001304 if( ExprHasProperty(p, EP_WinFunc) ){
001305 pNew->y.pWin = sqlite3WindowDup(db, pNew, p->y.pWin);
001306 assert( ExprHasProperty(pNew, EP_WinFunc) );
001307 }
001308 #endif /* SQLITE_OMIT_WINDOWFUNC */
001309 if( pzBuffer ){
001310 *pzBuffer = zAlloc;
001311 }
001312 }else{
001313 if( !ExprHasProperty(p, EP_TokenOnly|EP_Leaf) ){
001314 if( pNew->op==TK_SELECT_COLUMN ){
001315 pNew->pLeft = p->pLeft;
001316 assert( p->iColumn==0 || p->pRight==0 );
001317 assert( p->pRight==0 || p->pRight==p->pLeft );
001318 }else{
001319 pNew->pLeft = sqlite3ExprDup(db, p->pLeft, 0);
001320 }
001321 pNew->pRight = sqlite3ExprDup(db, p->pRight, 0);
001322 }
001323 }
001324 }
001325 return pNew;
001326 }
001327
001328 /*
001329 ** Create and return a deep copy of the object passed as the second
001330 ** argument. If an OOM condition is encountered, NULL is returned
001331 ** and the db->mallocFailed flag set.
001332 */
001333 #ifndef SQLITE_OMIT_CTE
001334 static With *withDup(sqlite3 *db, With *p){
001335 With *pRet = 0;
001336 if( p ){
001337 sqlite3_int64 nByte = sizeof(*p) + sizeof(p->a[0]) * (p->nCte-1);
001338 pRet = sqlite3DbMallocZero(db, nByte);
001339 if( pRet ){
001340 int i;
001341 pRet->nCte = p->nCte;
001342 for(i=0; i<p->nCte; i++){
001343 pRet->a[i].pSelect = sqlite3SelectDup(db, p->a[i].pSelect, 0);
001344 pRet->a[i].pCols = sqlite3ExprListDup(db, p->a[i].pCols, 0);
001345 pRet->a[i].zName = sqlite3DbStrDup(db, p->a[i].zName);
001346 }
001347 }
001348 }
001349 return pRet;
001350 }
001351 #else
001352 # define withDup(x,y) 0
001353 #endif
001354
001355 #ifndef SQLITE_OMIT_WINDOWFUNC
001356 /*
001357 ** The gatherSelectWindows() procedure and its helper routine
001358 ** gatherSelectWindowsCallback() are used to scan all the expressions
001359 ** an a newly duplicated SELECT statement and gather all of the Window
001360 ** objects found there, assembling them onto the linked list at Select->pWin.
001361 */
001362 static int gatherSelectWindowsCallback(Walker *pWalker, Expr *pExpr){
001363 if( pExpr->op==TK_FUNCTION && ExprHasProperty(pExpr, EP_WinFunc) ){
001364 Select *pSelect = pWalker->u.pSelect;
001365 Window *pWin = pExpr->y.pWin;
001366 assert( pWin );
001367 assert( IsWindowFunc(pExpr) );
001368 assert( pWin->ppThis==0 );
001369 sqlite3WindowLink(pSelect, pWin);
001370 }
001371 return WRC_Continue;
001372 }
001373 static int gatherSelectWindowsSelectCallback(Walker *pWalker, Select *p){
001374 return p==pWalker->u.pSelect ? WRC_Continue : WRC_Prune;
001375 }
001376 static void gatherSelectWindows(Select *p){
001377 Walker w;
001378 w.xExprCallback = gatherSelectWindowsCallback;
001379 w.xSelectCallback = gatherSelectWindowsSelectCallback;
001380 w.xSelectCallback2 = 0;
001381 w.pParse = 0;
001382 w.u.pSelect = p;
001383 sqlite3WalkSelect(&w, p);
001384 }
001385 #endif
001386
001387
001388 /*
001389 ** The following group of routines make deep copies of expressions,
001390 ** expression lists, ID lists, and select statements. The copies can
001391 ** be deleted (by being passed to their respective ...Delete() routines)
001392 ** without effecting the originals.
001393 **
001394 ** The expression list, ID, and source lists return by sqlite3ExprListDup(),
001395 ** sqlite3IdListDup(), and sqlite3SrcListDup() can not be further expanded
001396 ** by subsequent calls to sqlite*ListAppend() routines.
001397 **
001398 ** Any tables that the SrcList might point to are not duplicated.
001399 **
001400 ** The flags parameter contains a combination of the EXPRDUP_XXX flags.
001401 ** If the EXPRDUP_REDUCE flag is set, then the structure returned is a
001402 ** truncated version of the usual Expr structure that will be stored as
001403 ** part of the in-memory representation of the database schema.
001404 */
001405 Expr *sqlite3ExprDup(sqlite3 *db, Expr *p, int flags){
001406 assert( flags==0 || flags==EXPRDUP_REDUCE );
001407 return p ? exprDup(db, p, flags, 0) : 0;
001408 }
001409 ExprList *sqlite3ExprListDup(sqlite3 *db, ExprList *p, int flags){
001410 ExprList *pNew;
001411 struct ExprList_item *pItem, *pOldItem;
001412 int i;
001413 Expr *pPriorSelectCol = 0;
001414 assert( db!=0 );
001415 if( p==0 ) return 0;
001416 pNew = sqlite3DbMallocRawNN(db, sqlite3DbMallocSize(db, p));
001417 if( pNew==0 ) return 0;
001418 pNew->nExpr = p->nExpr;
001419 pItem = pNew->a;
001420 pOldItem = p->a;
001421 for(i=0; i<p->nExpr; i++, pItem++, pOldItem++){
001422 Expr *pOldExpr = pOldItem->pExpr;
001423 Expr *pNewExpr;
001424 pItem->pExpr = sqlite3ExprDup(db, pOldExpr, flags);
001425 if( pOldExpr
001426 && pOldExpr->op==TK_SELECT_COLUMN
001427 && (pNewExpr = pItem->pExpr)!=0
001428 ){
001429 assert( pNewExpr->iColumn==0 || i>0 );
001430 if( pNewExpr->iColumn==0 ){
001431 assert( pOldExpr->pLeft==pOldExpr->pRight );
001432 pPriorSelectCol = pNewExpr->pLeft = pNewExpr->pRight;
001433 }else{
001434 assert( i>0 );
001435 assert( pItem[-1].pExpr!=0 );
001436 assert( pNewExpr->iColumn==pItem[-1].pExpr->iColumn+1 );
001437 assert( pPriorSelectCol==pItem[-1].pExpr->pLeft );
001438 pNewExpr->pLeft = pPriorSelectCol;
001439 }
001440 }
001441 pItem->zName = sqlite3DbStrDup(db, pOldItem->zName);
001442 pItem->zSpan = sqlite3DbStrDup(db, pOldItem->zSpan);
001443 pItem->sortFlags = pOldItem->sortFlags;
001444 pItem->done = 0;
001445 pItem->bNulls = pOldItem->bNulls;
001446 pItem->bSpanIsTab = pOldItem->bSpanIsTab;
001447 pItem->bSorterRef = pOldItem->bSorterRef;
001448 pItem->u = pOldItem->u;
001449 }
001450 return pNew;
001451 }
001452
001453 /*
001454 ** If cursors, triggers, views and subqueries are all omitted from
001455 ** the build, then none of the following routines, except for
001456 ** sqlite3SelectDup(), can be called. sqlite3SelectDup() is sometimes
001457 ** called with a NULL argument.
001458 */
001459 #if !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_TRIGGER) \
001460 || !defined(SQLITE_OMIT_SUBQUERY)
001461 SrcList *sqlite3SrcListDup(sqlite3 *db, SrcList *p, int flags){
001462 SrcList *pNew;
001463 int i;
001464 int nByte;
001465 assert( db!=0 );
001466 if( p==0 ) return 0;
001467 nByte = sizeof(*p) + (p->nSrc>0 ? sizeof(p->a[0]) * (p->nSrc-1) : 0);
001468 pNew = sqlite3DbMallocRawNN(db, nByte );
001469 if( pNew==0 ) return 0;
001470 pNew->nSrc = pNew->nAlloc = p->nSrc;
001471 for(i=0; i<p->nSrc; i++){
001472 struct SrcList_item *pNewItem = &pNew->a[i];
001473 struct SrcList_item *pOldItem = &p->a[i];
001474 Table *pTab;
001475 pNewItem->pSchema = pOldItem->pSchema;
001476 pNewItem->zDatabase = sqlite3DbStrDup(db, pOldItem->zDatabase);
001477 pNewItem->zName = sqlite3DbStrDup(db, pOldItem->zName);
001478 pNewItem->zAlias = sqlite3DbStrDup(db, pOldItem->zAlias);
001479 pNewItem->fg = pOldItem->fg;
001480 pNewItem->iCursor = pOldItem->iCursor;
001481 pNewItem->addrFillSub = pOldItem->addrFillSub;
001482 pNewItem->regReturn = pOldItem->regReturn;
001483 if( pNewItem->fg.isIndexedBy ){
001484 pNewItem->u1.zIndexedBy = sqlite3DbStrDup(db, pOldItem->u1.zIndexedBy);
001485 }
001486 pNewItem->pIBIndex = pOldItem->pIBIndex;
001487 if( pNewItem->fg.isTabFunc ){
001488 pNewItem->u1.pFuncArg =
001489 sqlite3ExprListDup(db, pOldItem->u1.pFuncArg, flags);
001490 }
001491 pTab = pNewItem->pTab = pOldItem->pTab;
001492 if( pTab ){
001493 pTab->nTabRef++;
001494 }
001495 pNewItem->pSelect = sqlite3SelectDup(db, pOldItem->pSelect, flags);
001496 pNewItem->pOn = sqlite3ExprDup(db, pOldItem->pOn, flags);
001497 pNewItem->pUsing = sqlite3IdListDup(db, pOldItem->pUsing);
001498 pNewItem->colUsed = pOldItem->colUsed;
001499 }
001500 return pNew;
001501 }
001502 IdList *sqlite3IdListDup(sqlite3 *db, IdList *p){
001503 IdList *pNew;
001504 int i;
001505 assert( db!=0 );
001506 if( p==0 ) return 0;
001507 pNew = sqlite3DbMallocRawNN(db, sizeof(*pNew) );
001508 if( pNew==0 ) return 0;
001509 pNew->nId = p->nId;
001510 pNew->a = sqlite3DbMallocRawNN(db, p->nId*sizeof(p->a[0]) );
001511 if( pNew->a==0 ){
001512 sqlite3DbFreeNN(db, pNew);
001513 return 0;
001514 }
001515 /* Note that because the size of the allocation for p->a[] is not
001516 ** necessarily a power of two, sqlite3IdListAppend() may not be called
001517 ** on the duplicate created by this function. */
001518 for(i=0; i<p->nId; i++){
001519 struct IdList_item *pNewItem = &pNew->a[i];
001520 struct IdList_item *pOldItem = &p->a[i];
001521 pNewItem->zName = sqlite3DbStrDup(db, pOldItem->zName);
001522 pNewItem->idx = pOldItem->idx;
001523 }
001524 return pNew;
001525 }
001526 Select *sqlite3SelectDup(sqlite3 *db, Select *pDup, int flags){
001527 Select *pRet = 0;
001528 Select *pNext = 0;
001529 Select **pp = &pRet;
001530 Select *p;
001531
001532 assert( db!=0 );
001533 for(p=pDup; p; p=p->pPrior){
001534 Select *pNew = sqlite3DbMallocRawNN(db, sizeof(*p) );
001535 if( pNew==0 ) break;
001536 pNew->pEList = sqlite3ExprListDup(db, p->pEList, flags);
001537 pNew->pSrc = sqlite3SrcListDup(db, p->pSrc, flags);
001538 pNew->pWhere = sqlite3ExprDup(db, p->pWhere, flags);
001539 pNew->pGroupBy = sqlite3ExprListDup(db, p->pGroupBy, flags);
001540 pNew->pHaving = sqlite3ExprDup(db, p->pHaving, flags);
001541 pNew->pOrderBy = sqlite3ExprListDup(db, p->pOrderBy, flags);
001542 pNew->op = p->op;
001543 pNew->pNext = pNext;
001544 pNew->pPrior = 0;
001545 pNew->pLimit = sqlite3ExprDup(db, p->pLimit, flags);
001546 pNew->iLimit = 0;
001547 pNew->iOffset = 0;
001548 pNew->selFlags = p->selFlags & ~SF_UsesEphemeral;
001549 pNew->addrOpenEphm[0] = -1;
001550 pNew->addrOpenEphm[1] = -1;
001551 pNew->nSelectRow = p->nSelectRow;
001552 pNew->pWith = withDup(db, p->pWith);
001553 #ifndef SQLITE_OMIT_WINDOWFUNC
001554 pNew->pWin = 0;
001555 pNew->pWinDefn = sqlite3WindowListDup(db, p->pWinDefn);
001556 if( p->pWin && db->mallocFailed==0 ) gatherSelectWindows(pNew);
001557 #endif
001558 pNew->selId = p->selId;
001559 *pp = pNew;
001560 pp = &pNew->pPrior;
001561 pNext = pNew;
001562 }
001563
001564 return pRet;
001565 }
001566 #else
001567 Select *sqlite3SelectDup(sqlite3 *db, Select *p, int flags){
001568 assert( p==0 );
001569 return 0;
001570 }
001571 #endif
001572
001573
001574 /*
001575 ** Add a new element to the end of an expression list. If pList is
001576 ** initially NULL, then create a new expression list.
001577 **
001578 ** The pList argument must be either NULL or a pointer to an ExprList
001579 ** obtained from a prior call to sqlite3ExprListAppend(). This routine
001580 ** may not be used with an ExprList obtained from sqlite3ExprListDup().
001581 ** Reason: This routine assumes that the number of slots in pList->a[]
001582 ** is a power of two. That is true for sqlite3ExprListAppend() returns
001583 ** but is not necessarily true from the return value of sqlite3ExprListDup().
001584 **
001585 ** If a memory allocation error occurs, the entire list is freed and
001586 ** NULL is returned. If non-NULL is returned, then it is guaranteed
001587 ** that the new entry was successfully appended.
001588 */
001589 ExprList *sqlite3ExprListAppend(
001590 Parse *pParse, /* Parsing context */
001591 ExprList *pList, /* List to which to append. Might be NULL */
001592 Expr *pExpr /* Expression to be appended. Might be NULL */
001593 ){
001594 struct ExprList_item *pItem;
001595 sqlite3 *db = pParse->db;
001596 assert( db!=0 );
001597 if( pList==0 ){
001598 pList = sqlite3DbMallocRawNN(db, sizeof(ExprList) );
001599 if( pList==0 ){
001600 goto no_mem;
001601 }
001602 pList->nExpr = 0;
001603 }else if( (pList->nExpr & (pList->nExpr-1))==0 ){
001604 ExprList *pNew;
001605 pNew = sqlite3DbRealloc(db, pList,
001606 sizeof(*pList)+(2*(sqlite3_int64)pList->nExpr-1)*sizeof(pList->a[0]));
001607 if( pNew==0 ){
001608 goto no_mem;
001609 }
001610 pList = pNew;
001611 }
001612 pItem = &pList->a[pList->nExpr++];
001613 assert( offsetof(struct ExprList_item,zName)==sizeof(pItem->pExpr) );
001614 assert( offsetof(struct ExprList_item,pExpr)==0 );
001615 memset(&pItem->zName,0,sizeof(*pItem)-offsetof(struct ExprList_item,zName));
001616 pItem->pExpr = pExpr;
001617 return pList;
001618
001619 no_mem:
001620 /* Avoid leaking memory if malloc has failed. */
001621 sqlite3ExprDelete(db, pExpr);
001622 sqlite3ExprListDelete(db, pList);
001623 return 0;
001624 }
001625
001626 /*
001627 ** pColumns and pExpr form a vector assignment which is part of the SET
001628 ** clause of an UPDATE statement. Like this:
001629 **
001630 ** (a,b,c) = (expr1,expr2,expr3)
001631 ** Or: (a,b,c) = (SELECT x,y,z FROM ....)
001632 **
001633 ** For each term of the vector assignment, append new entries to the
001634 ** expression list pList. In the case of a subquery on the RHS, append
001635 ** TK_SELECT_COLUMN expressions.
001636 */
001637 ExprList *sqlite3ExprListAppendVector(
001638 Parse *pParse, /* Parsing context */
001639 ExprList *pList, /* List to which to append. Might be NULL */
001640 IdList *pColumns, /* List of names of LHS of the assignment */
001641 Expr *pExpr /* Vector expression to be appended. Might be NULL */
001642 ){
001643 sqlite3 *db = pParse->db;
001644 int n;
001645 int i;
001646 int iFirst = pList ? pList->nExpr : 0;
001647 /* pColumns can only be NULL due to an OOM but an OOM will cause an
001648 ** exit prior to this routine being invoked */
001649 if( NEVER(pColumns==0) ) goto vector_append_error;
001650 if( pExpr==0 ) goto vector_append_error;
001651
001652 /* If the RHS is a vector, then we can immediately check to see that
001653 ** the size of the RHS and LHS match. But if the RHS is a SELECT,
001654 ** wildcards ("*") in the result set of the SELECT must be expanded before
001655 ** we can do the size check, so defer the size check until code generation.
001656 */
001657 if( pExpr->op!=TK_SELECT && pColumns->nId!=(n=sqlite3ExprVectorSize(pExpr)) ){
001658 sqlite3ErrorMsg(pParse, "%d columns assigned %d values",
001659 pColumns->nId, n);
001660 goto vector_append_error;
001661 }
001662
001663 for(i=0; i<pColumns->nId; i++){
001664 Expr *pSubExpr = sqlite3ExprForVectorField(pParse, pExpr, i);
001665 assert( pSubExpr!=0 || db->mallocFailed );
001666 assert( pSubExpr==0 || pSubExpr->iTable==0 );
001667 if( pSubExpr==0 ) continue;
001668 pSubExpr->iTable = pColumns->nId;
001669 pList = sqlite3ExprListAppend(pParse, pList, pSubExpr);
001670 if( pList ){
001671 assert( pList->nExpr==iFirst+i+1 );
001672 pList->a[pList->nExpr-1].zName = pColumns->a[i].zName;
001673 pColumns->a[i].zName = 0;
001674 }
001675 }
001676
001677 if( !db->mallocFailed && pExpr->op==TK_SELECT && ALWAYS(pList!=0) ){
001678 Expr *pFirst = pList->a[iFirst].pExpr;
001679 assert( pFirst!=0 );
001680 assert( pFirst->op==TK_SELECT_COLUMN );
001681
001682 /* Store the SELECT statement in pRight so it will be deleted when
001683 ** sqlite3ExprListDelete() is called */
001684 pFirst->pRight = pExpr;
001685 pExpr = 0;
001686
001687 /* Remember the size of the LHS in iTable so that we can check that
001688 ** the RHS and LHS sizes match during code generation. */
001689 pFirst->iTable = pColumns->nId;
001690 }
001691
001692 vector_append_error:
001693 sqlite3ExprUnmapAndDelete(pParse, pExpr);
001694 sqlite3IdListDelete(db, pColumns);
001695 return pList;
001696 }
001697
001698 /*
001699 ** Set the sort order for the last element on the given ExprList.
001700 */
001701 void sqlite3ExprListSetSortOrder(ExprList *p, int iSortOrder, int eNulls){
001702 struct ExprList_item *pItem;
001703 if( p==0 ) return;
001704 assert( p->nExpr>0 );
001705
001706 assert( SQLITE_SO_UNDEFINED<0 && SQLITE_SO_ASC==0 && SQLITE_SO_DESC>0 );
001707 assert( iSortOrder==SQLITE_SO_UNDEFINED
001708 || iSortOrder==SQLITE_SO_ASC
001709 || iSortOrder==SQLITE_SO_DESC
001710 );
001711 assert( eNulls==SQLITE_SO_UNDEFINED
001712 || eNulls==SQLITE_SO_ASC
001713 || eNulls==SQLITE_SO_DESC
001714 );
001715
001716 pItem = &p->a[p->nExpr-1];
001717 assert( pItem->bNulls==0 );
001718 if( iSortOrder==SQLITE_SO_UNDEFINED ){
001719 iSortOrder = SQLITE_SO_ASC;
001720 }
001721 pItem->sortFlags = (u8)iSortOrder;
001722
001723 if( eNulls!=SQLITE_SO_UNDEFINED ){
001724 pItem->bNulls = 1;
001725 if( iSortOrder!=eNulls ){
001726 pItem->sortFlags |= KEYINFO_ORDER_BIGNULL;
001727 }
001728 }
001729 }
001730
001731 /*
001732 ** Set the ExprList.a[].zName element of the most recently added item
001733 ** on the expression list.
001734 **
001735 ** pList might be NULL following an OOM error. But pName should never be
001736 ** NULL. If a memory allocation fails, the pParse->db->mallocFailed flag
001737 ** is set.
001738 */
001739 void sqlite3ExprListSetName(
001740 Parse *pParse, /* Parsing context */
001741 ExprList *pList, /* List to which to add the span. */
001742 Token *pName, /* Name to be added */
001743 int dequote /* True to cause the name to be dequoted */
001744 ){
001745 assert( pList!=0 || pParse->db->mallocFailed!=0 );
001746 if( pList ){
001747 struct ExprList_item *pItem;
001748 assert( pList->nExpr>0 );
001749 pItem = &pList->a[pList->nExpr-1];
001750 assert( pItem->zName==0 );
001751 pItem->zName = sqlite3DbStrNDup(pParse->db, pName->z, pName->n);
001752 if( dequote ) sqlite3Dequote(pItem->zName);
001753 if( IN_RENAME_OBJECT ){
001754 sqlite3RenameTokenMap(pParse, (void*)pItem->zName, pName);
001755 }
001756 }
001757 }
001758
001759 /*
001760 ** Set the ExprList.a[].zSpan element of the most recently added item
001761 ** on the expression list.
001762 **
001763 ** pList might be NULL following an OOM error. But pSpan should never be
001764 ** NULL. If a memory allocation fails, the pParse->db->mallocFailed flag
001765 ** is set.
001766 */
001767 void sqlite3ExprListSetSpan(
001768 Parse *pParse, /* Parsing context */
001769 ExprList *pList, /* List to which to add the span. */
001770 const char *zStart, /* Start of the span */
001771 const char *zEnd /* End of the span */
001772 ){
001773 sqlite3 *db = pParse->db;
001774 assert( pList!=0 || db->mallocFailed!=0 );
001775 if( pList ){
001776 struct ExprList_item *pItem = &pList->a[pList->nExpr-1];
001777 assert( pList->nExpr>0 );
001778 sqlite3DbFree(db, pItem->zSpan);
001779 pItem->zSpan = sqlite3DbSpanDup(db, zStart, zEnd);
001780 }
001781 }
001782
001783 /*
001784 ** If the expression list pEList contains more than iLimit elements,
001785 ** leave an error message in pParse.
001786 */
001787 void sqlite3ExprListCheckLength(
001788 Parse *pParse,
001789 ExprList *pEList,
001790 const char *zObject
001791 ){
001792 int mx = pParse->db->aLimit[SQLITE_LIMIT_COLUMN];
001793 testcase( pEList && pEList->nExpr==mx );
001794 testcase( pEList && pEList->nExpr==mx+1 );
001795 if( pEList && pEList->nExpr>mx ){
001796 sqlite3ErrorMsg(pParse, "too many columns in %s", zObject);
001797 }
001798 }
001799
001800 /*
001801 ** Delete an entire expression list.
001802 */
001803 static SQLITE_NOINLINE void exprListDeleteNN(sqlite3 *db, ExprList *pList){
001804 int i = pList->nExpr;
001805 struct ExprList_item *pItem = pList->a;
001806 assert( pList->nExpr>0 );
001807 do{
001808 sqlite3ExprDelete(db, pItem->pExpr);
001809 sqlite3DbFree(db, pItem->zName);
001810 sqlite3DbFree(db, pItem->zSpan);
001811 pItem++;
001812 }while( --i>0 );
001813 sqlite3DbFreeNN(db, pList);
001814 }
001815 void sqlite3ExprListDelete(sqlite3 *db, ExprList *pList){
001816 if( pList ) exprListDeleteNN(db, pList);
001817 }
001818
001819 /*
001820 ** Return the bitwise-OR of all Expr.flags fields in the given
001821 ** ExprList.
001822 */
001823 u32 sqlite3ExprListFlags(const ExprList *pList){
001824 int i;
001825 u32 m = 0;
001826 assert( pList!=0 );
001827 for(i=0; i<pList->nExpr; i++){
001828 Expr *pExpr = pList->a[i].pExpr;
001829 assert( pExpr!=0 );
001830 m |= pExpr->flags;
001831 }
001832 return m;
001833 }
001834
001835 /*
001836 ** This is a SELECT-node callback for the expression walker that
001837 ** always "fails". By "fail" in this case, we mean set
001838 ** pWalker->eCode to zero and abort.
001839 **
001840 ** This callback is used by multiple expression walkers.
001841 */
001842 int sqlite3SelectWalkFail(Walker *pWalker, Select *NotUsed){
001843 UNUSED_PARAMETER(NotUsed);
001844 pWalker->eCode = 0;
001845 return WRC_Abort;
001846 }
001847
001848 /*
001849 ** If the input expression is an ID with the name "true" or "false"
001850 ** then convert it into an TK_TRUEFALSE term. Return non-zero if
001851 ** the conversion happened, and zero if the expression is unaltered.
001852 */
001853 int sqlite3ExprIdToTrueFalse(Expr *pExpr){
001854 assert( pExpr->op==TK_ID || pExpr->op==TK_STRING );
001855 if( !ExprHasProperty(pExpr, EP_Quoted)
001856 && (sqlite3StrICmp(pExpr->u.zToken, "true")==0
001857 || sqlite3StrICmp(pExpr->u.zToken, "false")==0)
001858 ){
001859 pExpr->op = TK_TRUEFALSE;
001860 ExprSetProperty(pExpr, pExpr->u.zToken[4]==0 ? EP_IsTrue : EP_IsFalse);
001861 return 1;
001862 }
001863 return 0;
001864 }
001865
001866 /*
001867 ** The argument must be a TK_TRUEFALSE Expr node. Return 1 if it is TRUE
001868 ** and 0 if it is FALSE.
001869 */
001870 int sqlite3ExprTruthValue(const Expr *pExpr){
001871 pExpr = sqlite3ExprSkipCollate((Expr*)pExpr);
001872 assert( pExpr->op==TK_TRUEFALSE );
001873 assert( sqlite3StrICmp(pExpr->u.zToken,"true")==0
001874 || sqlite3StrICmp(pExpr->u.zToken,"false")==0 );
001875 return pExpr->u.zToken[4]==0;
001876 }
001877
001878 /*
001879 ** If pExpr is an AND or OR expression, try to simplify it by eliminating
001880 ** terms that are always true or false. Return the simplified expression.
001881 ** Or return the original expression if no simplification is possible.
001882 **
001883 ** Examples:
001884 **
001885 ** (x<10) AND true => (x<10)
001886 ** (x<10) AND false => false
001887 ** (x<10) AND (y=22 OR false) => (x<10) AND (y=22)
001888 ** (x<10) AND (y=22 OR true) => (x<10)
001889 ** (y=22) OR true => true
001890 */
001891 Expr *sqlite3ExprSimplifiedAndOr(Expr *pExpr){
001892 assert( pExpr!=0 );
001893 if( pExpr->op==TK_AND || pExpr->op==TK_OR ){
001894 Expr *pRight = sqlite3ExprSimplifiedAndOr(pExpr->pRight);
001895 Expr *pLeft = sqlite3ExprSimplifiedAndOr(pExpr->pLeft);
001896 if( ExprAlwaysTrue(pLeft) || ExprAlwaysFalse(pRight) ){
001897 pExpr = pExpr->op==TK_AND ? pRight : pLeft;
001898 }else if( ExprAlwaysTrue(pRight) || ExprAlwaysFalse(pLeft) ){
001899 pExpr = pExpr->op==TK_AND ? pLeft : pRight;
001900 }
001901 }
001902 return pExpr;
001903 }
001904
001905
001906 /*
001907 ** These routines are Walker callbacks used to check expressions to
001908 ** see if they are "constant" for some definition of constant. The
001909 ** Walker.eCode value determines the type of "constant" we are looking
001910 ** for.
001911 **
001912 ** These callback routines are used to implement the following:
001913 **
001914 ** sqlite3ExprIsConstant() pWalker->eCode==1
001915 ** sqlite3ExprIsConstantNotJoin() pWalker->eCode==2
001916 ** sqlite3ExprIsTableConstant() pWalker->eCode==3
001917 ** sqlite3ExprIsConstantOrFunction() pWalker->eCode==4 or 5
001918 **
001919 ** In all cases, the callbacks set Walker.eCode=0 and abort if the expression
001920 ** is found to not be a constant.
001921 **
001922 ** The sqlite3ExprIsConstantOrFunction() is used for evaluating expressions
001923 ** in a CREATE TABLE statement. The Walker.eCode value is 5 when parsing
001924 ** an existing schema and 4 when processing a new statement. A bound
001925 ** parameter raises an error for new statements, but is silently converted
001926 ** to NULL for existing schemas. This allows sqlite_master tables that
001927 ** contain a bound parameter because they were generated by older versions
001928 ** of SQLite to be parsed by newer versions of SQLite without raising a
001929 ** malformed schema error.
001930 */
001931 static int exprNodeIsConstant(Walker *pWalker, Expr *pExpr){
001932
001933 /* If pWalker->eCode is 2 then any term of the expression that comes from
001934 ** the ON or USING clauses of a left join disqualifies the expression
001935 ** from being considered constant. */
001936 if( pWalker->eCode==2 && ExprHasProperty(pExpr, EP_FromJoin) ){
001937 pWalker->eCode = 0;
001938 return WRC_Abort;
001939 }
001940
001941 switch( pExpr->op ){
001942 /* Consider functions to be constant if all their arguments are constant
001943 ** and either pWalker->eCode==4 or 5 or the function has the
001944 ** SQLITE_FUNC_CONST flag. */
001945 case TK_FUNCTION:
001946 if( (pWalker->eCode>=4 || ExprHasProperty(pExpr,EP_ConstFunc))
001947 && !ExprHasProperty(pExpr, EP_WinFunc)
001948 ){
001949 return WRC_Continue;
001950 }else{
001951 pWalker->eCode = 0;
001952 return WRC_Abort;
001953 }
001954 case TK_ID:
001955 /* Convert "true" or "false" in a DEFAULT clause into the
001956 ** appropriate TK_TRUEFALSE operator */
001957 if( sqlite3ExprIdToTrueFalse(pExpr) ){
001958 return WRC_Prune;
001959 }
001960 /* Fall thru */
001961 case TK_COLUMN:
001962 case TK_AGG_FUNCTION:
001963 case TK_AGG_COLUMN:
001964 testcase( pExpr->op==TK_ID );
001965 testcase( pExpr->op==TK_COLUMN );
001966 testcase( pExpr->op==TK_AGG_FUNCTION );
001967 testcase( pExpr->op==TK_AGG_COLUMN );
001968 if( ExprHasProperty(pExpr, EP_FixedCol) && pWalker->eCode!=2 ){
001969 return WRC_Continue;
001970 }
001971 if( pWalker->eCode==3 && pExpr->iTable==pWalker->u.iCur ){
001972 return WRC_Continue;
001973 }
001974 /* Fall through */
001975 case TK_IF_NULL_ROW:
001976 case TK_REGISTER:
001977 testcase( pExpr->op==TK_REGISTER );
001978 testcase( pExpr->op==TK_IF_NULL_ROW );
001979 pWalker->eCode = 0;
001980 return WRC_Abort;
001981 case TK_VARIABLE:
001982 if( pWalker->eCode==5 ){
001983 /* Silently convert bound parameters that appear inside of CREATE
001984 ** statements into a NULL when parsing the CREATE statement text out
001985 ** of the sqlite_master table */
001986 pExpr->op = TK_NULL;
001987 }else if( pWalker->eCode==4 ){
001988 /* A bound parameter in a CREATE statement that originates from
001989 ** sqlite3_prepare() causes an error */
001990 pWalker->eCode = 0;
001991 return WRC_Abort;
001992 }
001993 /* Fall through */
001994 default:
001995 testcase( pExpr->op==TK_SELECT ); /* sqlite3SelectWalkFail() disallows */
001996 testcase( pExpr->op==TK_EXISTS ); /* sqlite3SelectWalkFail() disallows */
001997 return WRC_Continue;
001998 }
001999 }
002000 static int exprIsConst(Expr *p, int initFlag, int iCur){
002001 Walker w;
002002 w.eCode = initFlag;
002003 w.xExprCallback = exprNodeIsConstant;
002004 w.xSelectCallback = sqlite3SelectWalkFail;
002005 #ifdef SQLITE_DEBUG
002006 w.xSelectCallback2 = sqlite3SelectWalkAssert2;
002007 #endif
002008 w.u.iCur = iCur;
002009 sqlite3WalkExpr(&w, p);
002010 return w.eCode;
002011 }
002012
002013 /*
002014 ** Walk an expression tree. Return non-zero if the expression is constant
002015 ** and 0 if it involves variables or function calls.
002016 **
002017 ** For the purposes of this function, a double-quoted string (ex: "abc")
002018 ** is considered a variable but a single-quoted string (ex: 'abc') is
002019 ** a constant.
002020 */
002021 int sqlite3ExprIsConstant(Expr *p){
002022 return exprIsConst(p, 1, 0);
002023 }
002024
002025 /*
002026 ** Walk an expression tree. Return non-zero if
002027 **
002028 ** (1) the expression is constant, and
002029 ** (2) the expression does originate in the ON or USING clause
002030 ** of a LEFT JOIN, and
002031 ** (3) the expression does not contain any EP_FixedCol TK_COLUMN
002032 ** operands created by the constant propagation optimization.
002033 **
002034 ** When this routine returns true, it indicates that the expression
002035 ** can be added to the pParse->pConstExpr list and evaluated once when
002036 ** the prepared statement starts up. See sqlite3ExprCodeAtInit().
002037 */
002038 int sqlite3ExprIsConstantNotJoin(Expr *p){
002039 return exprIsConst(p, 2, 0);
002040 }
002041
002042 /*
002043 ** Walk an expression tree. Return non-zero if the expression is constant
002044 ** for any single row of the table with cursor iCur. In other words, the
002045 ** expression must not refer to any non-deterministic function nor any
002046 ** table other than iCur.
002047 */
002048 int sqlite3ExprIsTableConstant(Expr *p, int iCur){
002049 return exprIsConst(p, 3, iCur);
002050 }
002051
002052
002053 /*
002054 ** sqlite3WalkExpr() callback used by sqlite3ExprIsConstantOrGroupBy().
002055 */
002056 static int exprNodeIsConstantOrGroupBy(Walker *pWalker, Expr *pExpr){
002057 ExprList *pGroupBy = pWalker->u.pGroupBy;
002058 int i;
002059
002060 /* Check if pExpr is identical to any GROUP BY term. If so, consider
002061 ** it constant. */
002062 for(i=0; i<pGroupBy->nExpr; i++){
002063 Expr *p = pGroupBy->a[i].pExpr;
002064 if( sqlite3ExprCompare(0, pExpr, p, -1)<2 ){
002065 CollSeq *pColl = sqlite3ExprNNCollSeq(pWalker->pParse, p);
002066 if( sqlite3IsBinary(pColl) ){
002067 return WRC_Prune;
002068 }
002069 }
002070 }
002071
002072 /* Check if pExpr is a sub-select. If so, consider it variable. */
002073 if( ExprHasProperty(pExpr, EP_xIsSelect) ){
002074 pWalker->eCode = 0;
002075 return WRC_Abort;
002076 }
002077
002078 return exprNodeIsConstant(pWalker, pExpr);
002079 }
002080
002081 /*
002082 ** Walk the expression tree passed as the first argument. Return non-zero
002083 ** if the expression consists entirely of constants or copies of terms
002084 ** in pGroupBy that sort with the BINARY collation sequence.
002085 **
002086 ** This routine is used to determine if a term of the HAVING clause can
002087 ** be promoted into the WHERE clause. In order for such a promotion to work,
002088 ** the value of the HAVING clause term must be the same for all members of
002089 ** a "group". The requirement that the GROUP BY term must be BINARY
002090 ** assumes that no other collating sequence will have a finer-grained
002091 ** grouping than binary. In other words (A=B COLLATE binary) implies
002092 ** A=B in every other collating sequence. The requirement that the
002093 ** GROUP BY be BINARY is stricter than necessary. It would also work
002094 ** to promote HAVING clauses that use the same alternative collating
002095 ** sequence as the GROUP BY term, but that is much harder to check,
002096 ** alternative collating sequences are uncommon, and this is only an
002097 ** optimization, so we take the easy way out and simply require the
002098 ** GROUP BY to use the BINARY collating sequence.
002099 */
002100 int sqlite3ExprIsConstantOrGroupBy(Parse *pParse, Expr *p, ExprList *pGroupBy){
002101 Walker w;
002102 w.eCode = 1;
002103 w.xExprCallback = exprNodeIsConstantOrGroupBy;
002104 w.xSelectCallback = 0;
002105 w.u.pGroupBy = pGroupBy;
002106 w.pParse = pParse;
002107 sqlite3WalkExpr(&w, p);
002108 return w.eCode;
002109 }
002110
002111 /*
002112 ** Walk an expression tree. Return non-zero if the expression is constant
002113 ** or a function call with constant arguments. Return and 0 if there
002114 ** are any variables.
002115 **
002116 ** For the purposes of this function, a double-quoted string (ex: "abc")
002117 ** is considered a variable but a single-quoted string (ex: 'abc') is
002118 ** a constant.
002119 */
002120 int sqlite3ExprIsConstantOrFunction(Expr *p, u8 isInit){
002121 assert( isInit==0 || isInit==1 );
002122 return exprIsConst(p, 4+isInit, 0);
002123 }
002124
002125 #ifdef SQLITE_ENABLE_CURSOR_HINTS
002126 /*
002127 ** Walk an expression tree. Return 1 if the expression contains a
002128 ** subquery of some kind. Return 0 if there are no subqueries.
002129 */
002130 int sqlite3ExprContainsSubquery(Expr *p){
002131 Walker w;
002132 w.eCode = 1;
002133 w.xExprCallback = sqlite3ExprWalkNoop;
002134 w.xSelectCallback = sqlite3SelectWalkFail;
002135 #ifdef SQLITE_DEBUG
002136 w.xSelectCallback2 = sqlite3SelectWalkAssert2;
002137 #endif
002138 sqlite3WalkExpr(&w, p);
002139 return w.eCode==0;
002140 }
002141 #endif
002142
002143 /*
002144 ** If the expression p codes a constant integer that is small enough
002145 ** to fit in a 32-bit integer, return 1 and put the value of the integer
002146 ** in *pValue. If the expression is not an integer or if it is too big
002147 ** to fit in a signed 32-bit integer, return 0 and leave *pValue unchanged.
002148 */
002149 int sqlite3ExprIsInteger(Expr *p, int *pValue){
002150 int rc = 0;
002151 if( NEVER(p==0) ) return 0; /* Used to only happen following on OOM */
002152
002153 /* If an expression is an integer literal that fits in a signed 32-bit
002154 ** integer, then the EP_IntValue flag will have already been set */
002155 assert( p->op!=TK_INTEGER || (p->flags & EP_IntValue)!=0
002156 || sqlite3GetInt32(p->u.zToken, &rc)==0 );
002157
002158 if( p->flags & EP_IntValue ){
002159 *pValue = p->u.iValue;
002160 return 1;
002161 }
002162 switch( p->op ){
002163 case TK_UPLUS: {
002164 rc = sqlite3ExprIsInteger(p->pLeft, pValue);
002165 break;
002166 }
002167 case TK_UMINUS: {
002168 int v;
002169 if( sqlite3ExprIsInteger(p->pLeft, &v) ){
002170 assert( v!=(-2147483647-1) );
002171 *pValue = -v;
002172 rc = 1;
002173 }
002174 break;
002175 }
002176 default: break;
002177 }
002178 return rc;
002179 }
002180
002181 /*
002182 ** Return FALSE if there is no chance that the expression can be NULL.
002183 **
002184 ** If the expression might be NULL or if the expression is too complex
002185 ** to tell return TRUE.
002186 **
002187 ** This routine is used as an optimization, to skip OP_IsNull opcodes
002188 ** when we know that a value cannot be NULL. Hence, a false positive
002189 ** (returning TRUE when in fact the expression can never be NULL) might
002190 ** be a small performance hit but is otherwise harmless. On the other
002191 ** hand, a false negative (returning FALSE when the result could be NULL)
002192 ** will likely result in an incorrect answer. So when in doubt, return
002193 ** TRUE.
002194 */
002195 int sqlite3ExprCanBeNull(const Expr *p){
002196 u8 op;
002197 while( p->op==TK_UPLUS || p->op==TK_UMINUS ){
002198 p = p->pLeft;
002199 }
002200 op = p->op;
002201 if( op==TK_REGISTER ) op = p->op2;
002202 switch( op ){
002203 case TK_INTEGER:
002204 case TK_STRING:
002205 case TK_FLOAT:
002206 case TK_BLOB:
002207 return 0;
002208 case TK_COLUMN:
002209 return ExprHasProperty(p, EP_CanBeNull) ||
002210 p->y.pTab==0 || /* Reference to column of index on expression */
002211 (p->iColumn>=0
002212 && ALWAYS(p->y.pTab->aCol!=0) /* Defense against OOM problems */
002213 && p->y.pTab->aCol[p->iColumn].notNull==0);
002214 default:
002215 return 1;
002216 }
002217 }
002218
002219 /*
002220 ** Return TRUE if the given expression is a constant which would be
002221 ** unchanged by OP_Affinity with the affinity given in the second
002222 ** argument.
002223 **
002224 ** This routine is used to determine if the OP_Affinity operation
002225 ** can be omitted. When in doubt return FALSE. A false negative
002226 ** is harmless. A false positive, however, can result in the wrong
002227 ** answer.
002228 */
002229 int sqlite3ExprNeedsNoAffinityChange(const Expr *p, char aff){
002230 u8 op;
002231 int unaryMinus = 0;
002232 if( aff==SQLITE_AFF_BLOB ) return 1;
002233 while( p->op==TK_UPLUS || p->op==TK_UMINUS ){
002234 if( p->op==TK_UMINUS ) unaryMinus = 1;
002235 p = p->pLeft;
002236 }
002237 op = p->op;
002238 if( op==TK_REGISTER ) op = p->op2;
002239 switch( op ){
002240 case TK_INTEGER: {
002241 return aff>=SQLITE_AFF_NUMERIC;
002242 }
002243 case TK_FLOAT: {
002244 return aff>=SQLITE_AFF_NUMERIC;
002245 }
002246 case TK_STRING: {
002247 return !unaryMinus && aff==SQLITE_AFF_TEXT;
002248 }
002249 case TK_BLOB: {
002250 return !unaryMinus;
002251 }
002252 case TK_COLUMN: {
002253 assert( p->iTable>=0 ); /* p cannot be part of a CHECK constraint */
002254 return aff>=SQLITE_AFF_NUMERIC && p->iColumn<0;
002255 }
002256 default: {
002257 return 0;
002258 }
002259 }
002260 }
002261
002262 /*
002263 ** Return TRUE if the given string is a row-id column name.
002264 */
002265 int sqlite3IsRowid(const char *z){
002266 if( sqlite3StrICmp(z, "_ROWID_")==0 ) return 1;
002267 if( sqlite3StrICmp(z, "ROWID")==0 ) return 1;
002268 if( sqlite3StrICmp(z, "OID")==0 ) return 1;
002269 return 0;
002270 }
002271
002272 /*
002273 ** pX is the RHS of an IN operator. If pX is a SELECT statement
002274 ** that can be simplified to a direct table access, then return
002275 ** a pointer to the SELECT statement. If pX is not a SELECT statement,
002276 ** or if the SELECT statement needs to be manifested into a transient
002277 ** table, then return NULL.
002278 */
002279 #ifndef SQLITE_OMIT_SUBQUERY
002280 static Select *isCandidateForInOpt(Expr *pX){
002281 Select *p;
002282 SrcList *pSrc;
002283 ExprList *pEList;
002284 Table *pTab;
002285 int i;
002286 if( !ExprHasProperty(pX, EP_xIsSelect) ) return 0; /* Not a subquery */
002287 if( ExprHasProperty(pX, EP_VarSelect) ) return 0; /* Correlated subq */
002288 p = pX->x.pSelect;
002289 if( p->pPrior ) return 0; /* Not a compound SELECT */
002290 if( p->selFlags & (SF_Distinct|SF_Aggregate) ){
002291 testcase( (p->selFlags & (SF_Distinct|SF_Aggregate))==SF_Distinct );
002292 testcase( (p->selFlags & (SF_Distinct|SF_Aggregate))==SF_Aggregate );
002293 return 0; /* No DISTINCT keyword and no aggregate functions */
002294 }
002295 if( p->pGroupBy ) return 0; /* Has no GROUP BY clause */
002296 if( p->pLimit ) return 0; /* Has no LIMIT clause */
002297 if( p->pWhere ) return 0; /* Has no WHERE clause */
002298 pSrc = p->pSrc;
002299 assert( pSrc!=0 );
002300 if( pSrc->nSrc!=1 ) return 0; /* Single term in FROM clause */
002301 if( pSrc->a[0].pSelect ) return 0; /* FROM is not a subquery or view */
002302 pTab = pSrc->a[0].pTab;
002303 assert( pTab!=0 );
002304 assert( pTab->pSelect==0 ); /* FROM clause is not a view */
002305 if( IsVirtual(pTab) ) return 0; /* FROM clause not a virtual table */
002306 pEList = p->pEList;
002307 assert( pEList!=0 );
002308 /* All SELECT results must be columns. */
002309 for(i=0; i<pEList->nExpr; i++){
002310 Expr *pRes = pEList->a[i].pExpr;
002311 if( pRes->op!=TK_COLUMN ) return 0;
002312 assert( pRes->iTable==pSrc->a[0].iCursor ); /* Not a correlated subquery */
002313 }
002314 return p;
002315 }
002316 #endif /* SQLITE_OMIT_SUBQUERY */
002317
002318 #ifndef SQLITE_OMIT_SUBQUERY
002319 /*
002320 ** Generate code that checks the left-most column of index table iCur to see if
002321 ** it contains any NULL entries. Cause the register at regHasNull to be set
002322 ** to a non-NULL value if iCur contains no NULLs. Cause register regHasNull
002323 ** to be set to NULL if iCur contains one or more NULL values.
002324 */
002325 static void sqlite3SetHasNullFlag(Vdbe *v, int iCur, int regHasNull){
002326 int addr1;
002327 sqlite3VdbeAddOp2(v, OP_Integer, 0, regHasNull);
002328 addr1 = sqlite3VdbeAddOp1(v, OP_Rewind, iCur); VdbeCoverage(v);
002329 sqlite3VdbeAddOp3(v, OP_Column, iCur, 0, regHasNull);
002330 sqlite3VdbeChangeP5(v, OPFLAG_TYPEOFARG);
002331 VdbeComment((v, "first_entry_in(%d)", iCur));
002332 sqlite3VdbeJumpHere(v, addr1);
002333 }
002334 #endif
002335
002336
002337 #ifndef SQLITE_OMIT_SUBQUERY
002338 /*
002339 ** The argument is an IN operator with a list (not a subquery) on the
002340 ** right-hand side. Return TRUE if that list is constant.
002341 */
002342 static int sqlite3InRhsIsConstant(Expr *pIn){
002343 Expr *pLHS;
002344 int res;
002345 assert( !ExprHasProperty(pIn, EP_xIsSelect) );
002346 pLHS = pIn->pLeft;
002347 pIn->pLeft = 0;
002348 res = sqlite3ExprIsConstant(pIn);
002349 pIn->pLeft = pLHS;
002350 return res;
002351 }
002352 #endif
002353
002354 /*
002355 ** This function is used by the implementation of the IN (...) operator.
002356 ** The pX parameter is the expression on the RHS of the IN operator, which
002357 ** might be either a list of expressions or a subquery.
002358 **
002359 ** The job of this routine is to find or create a b-tree object that can
002360 ** be used either to test for membership in the RHS set or to iterate through
002361 ** all members of the RHS set, skipping duplicates.
002362 **
002363 ** A cursor is opened on the b-tree object that is the RHS of the IN operator
002364 ** and pX->iTable is set to the index of that cursor.
002365 **
002366 ** The returned value of this function indicates the b-tree type, as follows:
002367 **
002368 ** IN_INDEX_ROWID - The cursor was opened on a database table.
002369 ** IN_INDEX_INDEX_ASC - The cursor was opened on an ascending index.
002370 ** IN_INDEX_INDEX_DESC - The cursor was opened on a descending index.
002371 ** IN_INDEX_EPH - The cursor was opened on a specially created and
002372 ** populated epheremal table.
002373 ** IN_INDEX_NOOP - No cursor was allocated. The IN operator must be
002374 ** implemented as a sequence of comparisons.
002375 **
002376 ** An existing b-tree might be used if the RHS expression pX is a simple
002377 ** subquery such as:
002378 **
002379 ** SELECT <column1>, <column2>... FROM <table>
002380 **
002381 ** If the RHS of the IN operator is a list or a more complex subquery, then
002382 ** an ephemeral table might need to be generated from the RHS and then
002383 ** pX->iTable made to point to the ephemeral table instead of an
002384 ** existing table.
002385 **
002386 ** The inFlags parameter must contain, at a minimum, one of the bits
002387 ** IN_INDEX_MEMBERSHIP or IN_INDEX_LOOP but not both. If inFlags contains
002388 ** IN_INDEX_MEMBERSHIP, then the generated table will be used for a fast
002389 ** membership test. When the IN_INDEX_LOOP bit is set, the IN index will
002390 ** be used to loop over all values of the RHS of the IN operator.
002391 **
002392 ** When IN_INDEX_LOOP is used (and the b-tree will be used to iterate
002393 ** through the set members) then the b-tree must not contain duplicates.
002394 ** An epheremal table will be created unless the selected columns are guaranteed
002395 ** to be unique - either because it is an INTEGER PRIMARY KEY or due to
002396 ** a UNIQUE constraint or index.
002397 **
002398 ** When IN_INDEX_MEMBERSHIP is used (and the b-tree will be used
002399 ** for fast set membership tests) then an epheremal table must
002400 ** be used unless <columns> is a single INTEGER PRIMARY KEY column or an
002401 ** index can be found with the specified <columns> as its left-most.
002402 **
002403 ** If the IN_INDEX_NOOP_OK and IN_INDEX_MEMBERSHIP are both set and
002404 ** if the RHS of the IN operator is a list (not a subquery) then this
002405 ** routine might decide that creating an ephemeral b-tree for membership
002406 ** testing is too expensive and return IN_INDEX_NOOP. In that case, the
002407 ** calling routine should implement the IN operator using a sequence
002408 ** of Eq or Ne comparison operations.
002409 **
002410 ** When the b-tree is being used for membership tests, the calling function
002411 ** might need to know whether or not the RHS side of the IN operator
002412 ** contains a NULL. If prRhsHasNull is not a NULL pointer and
002413 ** if there is any chance that the (...) might contain a NULL value at
002414 ** runtime, then a register is allocated and the register number written
002415 ** to *prRhsHasNull. If there is no chance that the (...) contains a
002416 ** NULL value, then *prRhsHasNull is left unchanged.
002417 **
002418 ** If a register is allocated and its location stored in *prRhsHasNull, then
002419 ** the value in that register will be NULL if the b-tree contains one or more
002420 ** NULL values, and it will be some non-NULL value if the b-tree contains no
002421 ** NULL values.
002422 **
002423 ** If the aiMap parameter is not NULL, it must point to an array containing
002424 ** one element for each column returned by the SELECT statement on the RHS
002425 ** of the IN(...) operator. The i'th entry of the array is populated with the
002426 ** offset of the index column that matches the i'th column returned by the
002427 ** SELECT. For example, if the expression and selected index are:
002428 **
002429 ** (?,?,?) IN (SELECT a, b, c FROM t1)
002430 ** CREATE INDEX i1 ON t1(b, c, a);
002431 **
002432 ** then aiMap[] is populated with {2, 0, 1}.
002433 */
002434 #ifndef SQLITE_OMIT_SUBQUERY
002435 int sqlite3FindInIndex(
002436 Parse *pParse, /* Parsing context */
002437 Expr *pX, /* The IN expression */
002438 u32 inFlags, /* IN_INDEX_LOOP, _MEMBERSHIP, and/or _NOOP_OK */
002439 int *prRhsHasNull, /* Register holding NULL status. See notes */
002440 int *aiMap, /* Mapping from Index fields to RHS fields */
002441 int *piTab /* OUT: index to use */
002442 ){
002443 Select *p; /* SELECT to the right of IN operator */
002444 int eType = 0; /* Type of RHS table. IN_INDEX_* */
002445 int iTab = pParse->nTab++; /* Cursor of the RHS table */
002446 int mustBeUnique; /* True if RHS must be unique */
002447 Vdbe *v = sqlite3GetVdbe(pParse); /* Virtual machine being coded */
002448
002449 assert( pX->op==TK_IN );
002450 mustBeUnique = (inFlags & IN_INDEX_LOOP)!=0;
002451
002452 /* If the RHS of this IN(...) operator is a SELECT, and if it matters
002453 ** whether or not the SELECT result contains NULL values, check whether
002454 ** or not NULL is actually possible (it may not be, for example, due
002455 ** to NOT NULL constraints in the schema). If no NULL values are possible,
002456 ** set prRhsHasNull to 0 before continuing. */
002457 if( prRhsHasNull && (pX->flags & EP_xIsSelect) ){
002458 int i;
002459 ExprList *pEList = pX->x.pSelect->pEList;
002460 for(i=0; i<pEList->nExpr; i++){
002461 if( sqlite3ExprCanBeNull(pEList->a[i].pExpr) ) break;
002462 }
002463 if( i==pEList->nExpr ){
002464 prRhsHasNull = 0;
002465 }
002466 }
002467
002468 /* Check to see if an existing table or index can be used to
002469 ** satisfy the query. This is preferable to generating a new
002470 ** ephemeral table. */
002471 if( pParse->nErr==0 && (p = isCandidateForInOpt(pX))!=0 ){
002472 sqlite3 *db = pParse->db; /* Database connection */
002473 Table *pTab; /* Table <table>. */
002474 i16 iDb; /* Database idx for pTab */
002475 ExprList *pEList = p->pEList;
002476 int nExpr = pEList->nExpr;
002477
002478 assert( p->pEList!=0 ); /* Because of isCandidateForInOpt(p) */
002479 assert( p->pEList->a[0].pExpr!=0 ); /* Because of isCandidateForInOpt(p) */
002480 assert( p->pSrc!=0 ); /* Because of isCandidateForInOpt(p) */
002481 pTab = p->pSrc->a[0].pTab;
002482
002483 /* Code an OP_Transaction and OP_TableLock for <table>. */
002484 iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
002485 sqlite3CodeVerifySchema(pParse, iDb);
002486 sqlite3TableLock(pParse, iDb, pTab->tnum, 0, pTab->zName);
002487
002488 assert(v); /* sqlite3GetVdbe() has always been previously called */
002489 if( nExpr==1 && pEList->a[0].pExpr->iColumn<0 ){
002490 /* The "x IN (SELECT rowid FROM table)" case */
002491 int iAddr = sqlite3VdbeAddOp0(v, OP_Once);
002492 VdbeCoverage(v);
002493
002494 sqlite3OpenTable(pParse, iTab, iDb, pTab, OP_OpenRead);
002495 eType = IN_INDEX_ROWID;
002496 ExplainQueryPlan((pParse, 0,
002497 "USING ROWID SEARCH ON TABLE %s FOR IN-OPERATOR",pTab->zName));
002498 sqlite3VdbeJumpHere(v, iAddr);
002499 }else{
002500 Index *pIdx; /* Iterator variable */
002501 int affinity_ok = 1;
002502 int i;
002503
002504 /* Check that the affinity that will be used to perform each
002505 ** comparison is the same as the affinity of each column in table
002506 ** on the RHS of the IN operator. If it not, it is not possible to
002507 ** use any index of the RHS table. */
002508 for(i=0; i<nExpr && affinity_ok; i++){
002509 Expr *pLhs = sqlite3VectorFieldSubexpr(pX->pLeft, i);
002510 int iCol = pEList->a[i].pExpr->iColumn;
002511 char idxaff = sqlite3TableColumnAffinity(pTab,iCol); /* RHS table */
002512 char cmpaff = sqlite3CompareAffinity(pLhs, idxaff);
002513 testcase( cmpaff==SQLITE_AFF_BLOB );
002514 testcase( cmpaff==SQLITE_AFF_TEXT );
002515 switch( cmpaff ){
002516 case SQLITE_AFF_BLOB:
002517 break;
002518 case SQLITE_AFF_TEXT:
002519 /* sqlite3CompareAffinity() only returns TEXT if one side or the
002520 ** other has no affinity and the other side is TEXT. Hence,
002521 ** the only way for cmpaff to be TEXT is for idxaff to be TEXT
002522 ** and for the term on the LHS of the IN to have no affinity. */
002523 assert( idxaff==SQLITE_AFF_TEXT );
002524 break;
002525 default:
002526 affinity_ok = sqlite3IsNumericAffinity(idxaff);
002527 }
002528 }
002529
002530 if( affinity_ok ){
002531 /* Search for an existing index that will work for this IN operator */
002532 for(pIdx=pTab->pIndex; pIdx && eType==0; pIdx=pIdx->pNext){
002533 Bitmask colUsed; /* Columns of the index used */
002534 Bitmask mCol; /* Mask for the current column */
002535 if( pIdx->nColumn<nExpr ) continue;
002536 if( pIdx->pPartIdxWhere!=0 ) continue;
002537 /* Maximum nColumn is BMS-2, not BMS-1, so that we can compute
002538 ** BITMASK(nExpr) without overflowing */
002539 testcase( pIdx->nColumn==BMS-2 );
002540 testcase( pIdx->nColumn==BMS-1 );
002541 if( pIdx->nColumn>=BMS-1 ) continue;
002542 if( mustBeUnique ){
002543 if( pIdx->nKeyCol>nExpr
002544 ||(pIdx->nColumn>nExpr && !IsUniqueIndex(pIdx))
002545 ){
002546 continue; /* This index is not unique over the IN RHS columns */
002547 }
002548 }
002549
002550 colUsed = 0; /* Columns of index used so far */
002551 for(i=0; i<nExpr; i++){
002552 Expr *pLhs = sqlite3VectorFieldSubexpr(pX->pLeft, i);
002553 Expr *pRhs = pEList->a[i].pExpr;
002554 CollSeq *pReq = sqlite3BinaryCompareCollSeq(pParse, pLhs, pRhs);
002555 int j;
002556
002557 assert( pReq!=0 || pRhs->iColumn==XN_ROWID || pParse->nErr );
002558 for(j=0; j<nExpr; j++){
002559 if( pIdx->aiColumn[j]!=pRhs->iColumn ) continue;
002560 assert( pIdx->azColl[j] );
002561 if( pReq!=0 && sqlite3StrICmp(pReq->zName, pIdx->azColl[j])!=0 ){
002562 continue;
002563 }
002564 break;
002565 }
002566 if( j==nExpr ) break;
002567 mCol = MASKBIT(j);
002568 if( mCol & colUsed ) break; /* Each column used only once */
002569 colUsed |= mCol;
002570 if( aiMap ) aiMap[i] = j;
002571 }
002572
002573 assert( i==nExpr || colUsed!=(MASKBIT(nExpr)-1) );
002574 if( colUsed==(MASKBIT(nExpr)-1) ){
002575 /* If we reach this point, that means the index pIdx is usable */
002576 int iAddr = sqlite3VdbeAddOp0(v, OP_Once); VdbeCoverage(v);
002577 ExplainQueryPlan((pParse, 0,
002578 "USING INDEX %s FOR IN-OPERATOR",pIdx->zName));
002579 sqlite3VdbeAddOp3(v, OP_OpenRead, iTab, pIdx->tnum, iDb);
002580 sqlite3VdbeSetP4KeyInfo(pParse, pIdx);
002581 VdbeComment((v, "%s", pIdx->zName));
002582 assert( IN_INDEX_INDEX_DESC == IN_INDEX_INDEX_ASC+1 );
002583 eType = IN_INDEX_INDEX_ASC + pIdx->aSortOrder[0];
002584
002585 if( prRhsHasNull ){
002586 #ifdef SQLITE_ENABLE_COLUMN_USED_MASK
002587 i64 mask = (1<<nExpr)-1;
002588 sqlite3VdbeAddOp4Dup8(v, OP_ColumnsUsed,
002589 iTab, 0, 0, (u8*)&mask, P4_INT64);
002590 #endif
002591 *prRhsHasNull = ++pParse->nMem;
002592 if( nExpr==1 ){
002593 sqlite3SetHasNullFlag(v, iTab, *prRhsHasNull);
002594 }
002595 }
002596 sqlite3VdbeJumpHere(v, iAddr);
002597 }
002598 } /* End loop over indexes */
002599 } /* End if( affinity_ok ) */
002600 } /* End if not an rowid index */
002601 } /* End attempt to optimize using an index */
002602
002603 /* If no preexisting index is available for the IN clause
002604 ** and IN_INDEX_NOOP is an allowed reply
002605 ** and the RHS of the IN operator is a list, not a subquery
002606 ** and the RHS is not constant or has two or fewer terms,
002607 ** then it is not worth creating an ephemeral table to evaluate
002608 ** the IN operator so return IN_INDEX_NOOP.
002609 */
002610 if( eType==0
002611 && (inFlags & IN_INDEX_NOOP_OK)
002612 && !ExprHasProperty(pX, EP_xIsSelect)
002613 && (!sqlite3InRhsIsConstant(pX) || pX->x.pList->nExpr<=2)
002614 ){
002615 eType = IN_INDEX_NOOP;
002616 }
002617
002618 if( eType==0 ){
002619 /* Could not find an existing table or index to use as the RHS b-tree.
002620 ** We will have to generate an ephemeral table to do the job.
002621 */
002622 u32 savedNQueryLoop = pParse->nQueryLoop;
002623 int rMayHaveNull = 0;
002624 eType = IN_INDEX_EPH;
002625 if( inFlags & IN_INDEX_LOOP ){
002626 pParse->nQueryLoop = 0;
002627 }else if( prRhsHasNull ){
002628 *prRhsHasNull = rMayHaveNull = ++pParse->nMem;
002629 }
002630 assert( pX->op==TK_IN );
002631 sqlite3CodeRhsOfIN(pParse, pX, iTab);
002632 if( rMayHaveNull ){
002633 sqlite3SetHasNullFlag(v, iTab, rMayHaveNull);
002634 }
002635 pParse->nQueryLoop = savedNQueryLoop;
002636 }
002637
002638 if( aiMap && eType!=IN_INDEX_INDEX_ASC && eType!=IN_INDEX_INDEX_DESC ){
002639 int i, n;
002640 n = sqlite3ExprVectorSize(pX->pLeft);
002641 for(i=0; i<n; i++) aiMap[i] = i;
002642 }
002643 *piTab = iTab;
002644 return eType;
002645 }
002646 #endif
002647
002648 #ifndef SQLITE_OMIT_SUBQUERY
002649 /*
002650 ** Argument pExpr is an (?, ?...) IN(...) expression. This
002651 ** function allocates and returns a nul-terminated string containing
002652 ** the affinities to be used for each column of the comparison.
002653 **
002654 ** It is the responsibility of the caller to ensure that the returned
002655 ** string is eventually freed using sqlite3DbFree().
002656 */
002657 static char *exprINAffinity(Parse *pParse, Expr *pExpr){
002658 Expr *pLeft = pExpr->pLeft;
002659 int nVal = sqlite3ExprVectorSize(pLeft);
002660 Select *pSelect = (pExpr->flags & EP_xIsSelect) ? pExpr->x.pSelect : 0;
002661 char *zRet;
002662
002663 assert( pExpr->op==TK_IN );
002664 zRet = sqlite3DbMallocRaw(pParse->db, nVal+1);
002665 if( zRet ){
002666 int i;
002667 for(i=0; i<nVal; i++){
002668 Expr *pA = sqlite3VectorFieldSubexpr(pLeft, i);
002669 char a = sqlite3ExprAffinity(pA);
002670 if( pSelect ){
002671 zRet[i] = sqlite3CompareAffinity(pSelect->pEList->a[i].pExpr, a);
002672 }else{
002673 zRet[i] = a;
002674 }
002675 }
002676 zRet[nVal] = '\0';
002677 }
002678 return zRet;
002679 }
002680 #endif
002681
002682 #ifndef SQLITE_OMIT_SUBQUERY
002683 /*
002684 ** Load the Parse object passed as the first argument with an error
002685 ** message of the form:
002686 **
002687 ** "sub-select returns N columns - expected M"
002688 */
002689 void sqlite3SubselectError(Parse *pParse, int nActual, int nExpect){
002690 if( pParse->nErr==0 ){
002691 const char *zFmt = "sub-select returns %d columns - expected %d";
002692 sqlite3ErrorMsg(pParse, zFmt, nActual, nExpect);
002693 }
002694 }
002695 #endif
002696
002697 /*
002698 ** Expression pExpr is a vector that has been used in a context where
002699 ** it is not permitted. If pExpr is a sub-select vector, this routine
002700 ** loads the Parse object with a message of the form:
002701 **
002702 ** "sub-select returns N columns - expected 1"
002703 **
002704 ** Or, if it is a regular scalar vector:
002705 **
002706 ** "row value misused"
002707 */
002708 void sqlite3VectorErrorMsg(Parse *pParse, Expr *pExpr){
002709 #ifndef SQLITE_OMIT_SUBQUERY
002710 if( pExpr->flags & EP_xIsSelect ){
002711 sqlite3SubselectError(pParse, pExpr->x.pSelect->pEList->nExpr, 1);
002712 }else
002713 #endif
002714 {
002715 sqlite3ErrorMsg(pParse, "row value misused");
002716 }
002717 }
002718
002719 #ifndef SQLITE_OMIT_SUBQUERY
002720 /*
002721 ** Generate code that will construct an ephemeral table containing all terms
002722 ** in the RHS of an IN operator. The IN operator can be in either of two
002723 ** forms:
002724 **
002725 ** x IN (4,5,11) -- IN operator with list on right-hand side
002726 ** x IN (SELECT a FROM b) -- IN operator with subquery on the right
002727 **
002728 ** The pExpr parameter is the IN operator. The cursor number for the
002729 ** constructed ephermeral table is returned. The first time the ephemeral
002730 ** table is computed, the cursor number is also stored in pExpr->iTable,
002731 ** however the cursor number returned might not be the same, as it might
002732 ** have been duplicated using OP_OpenDup.
002733 **
002734 ** If the LHS expression ("x" in the examples) is a column value, or
002735 ** the SELECT statement returns a column value, then the affinity of that
002736 ** column is used to build the index keys. If both 'x' and the
002737 ** SELECT... statement are columns, then numeric affinity is used
002738 ** if either column has NUMERIC or INTEGER affinity. If neither
002739 ** 'x' nor the SELECT... statement are columns, then numeric affinity
002740 ** is used.
002741 */
002742 void sqlite3CodeRhsOfIN(
002743 Parse *pParse, /* Parsing context */
002744 Expr *pExpr, /* The IN operator */
002745 int iTab /* Use this cursor number */
002746 ){
002747 int addrOnce = 0; /* Address of the OP_Once instruction at top */
002748 int addr; /* Address of OP_OpenEphemeral instruction */
002749 Expr *pLeft; /* the LHS of the IN operator */
002750 KeyInfo *pKeyInfo = 0; /* Key information */
002751 int nVal; /* Size of vector pLeft */
002752 Vdbe *v; /* The prepared statement under construction */
002753
002754 v = pParse->pVdbe;
002755 assert( v!=0 );
002756
002757 /* The evaluation of the IN must be repeated every time it
002758 ** is encountered if any of the following is true:
002759 **
002760 ** * The right-hand side is a correlated subquery
002761 ** * The right-hand side is an expression list containing variables
002762 ** * We are inside a trigger
002763 **
002764 ** If all of the above are false, then we can compute the RHS just once
002765 ** and reuse it many names.
002766 */
002767 if( !ExprHasProperty(pExpr, EP_VarSelect) && pParse->iSelfTab==0 ){
002768 /* Reuse of the RHS is allowed */
002769 /* If this routine has already been coded, but the previous code
002770 ** might not have been invoked yet, so invoke it now as a subroutine.
002771 */
002772 if( ExprHasProperty(pExpr, EP_Subrtn) ){
002773 addrOnce = sqlite3VdbeAddOp0(v, OP_Once); VdbeCoverage(v);
002774 if( ExprHasProperty(pExpr, EP_xIsSelect) ){
002775 ExplainQueryPlan((pParse, 0, "REUSE LIST SUBQUERY %d",
002776 pExpr->x.pSelect->selId));
002777 }
002778 sqlite3VdbeAddOp2(v, OP_Gosub, pExpr->y.sub.regReturn,
002779 pExpr->y.sub.iAddr);
002780 sqlite3VdbeAddOp2(v, OP_OpenDup, iTab, pExpr->iTable);
002781 sqlite3VdbeJumpHere(v, addrOnce);
002782 return;
002783 }
002784
002785 /* Begin coding the subroutine */
002786 ExprSetProperty(pExpr, EP_Subrtn);
002787 pExpr->y.sub.regReturn = ++pParse->nMem;
002788 pExpr->y.sub.iAddr =
002789 sqlite3VdbeAddOp2(v, OP_Integer, 0, pExpr->y.sub.regReturn) + 1;
002790 VdbeComment((v, "return address"));
002791
002792 addrOnce = sqlite3VdbeAddOp0(v, OP_Once); VdbeCoverage(v);
002793 }
002794
002795 /* Check to see if this is a vector IN operator */
002796 pLeft = pExpr->pLeft;
002797 nVal = sqlite3ExprVectorSize(pLeft);
002798
002799 /* Construct the ephemeral table that will contain the content of
002800 ** RHS of the IN operator.
002801 */
002802 pExpr->iTable = iTab;
002803 addr = sqlite3VdbeAddOp2(v, OP_OpenEphemeral, pExpr->iTable, nVal);
002804 #ifdef SQLITE_ENABLE_EXPLAIN_COMMENTS
002805 if( ExprHasProperty(pExpr, EP_xIsSelect) ){
002806 VdbeComment((v, "Result of SELECT %u", pExpr->x.pSelect->selId));
002807 }else{
002808 VdbeComment((v, "RHS of IN operator"));
002809 }
002810 #endif
002811 pKeyInfo = sqlite3KeyInfoAlloc(pParse->db, nVal, 1);
002812
002813 if( ExprHasProperty(pExpr, EP_xIsSelect) ){
002814 /* Case 1: expr IN (SELECT ...)
002815 **
002816 ** Generate code to write the results of the select into the temporary
002817 ** table allocated and opened above.
002818 */
002819 Select *pSelect = pExpr->x.pSelect;
002820 ExprList *pEList = pSelect->pEList;
002821
002822 ExplainQueryPlan((pParse, 1, "%sLIST SUBQUERY %d",
002823 addrOnce?"":"CORRELATED ", pSelect->selId
002824 ));
002825 /* If the LHS and RHS of the IN operator do not match, that
002826 ** error will have been caught long before we reach this point. */
002827 if( ALWAYS(pEList->nExpr==nVal) ){
002828 SelectDest dest;
002829 int i;
002830 sqlite3SelectDestInit(&dest, SRT_Set, iTab);
002831 dest.zAffSdst = exprINAffinity(pParse, pExpr);
002832 pSelect->iLimit = 0;
002833 testcase( pSelect->selFlags & SF_Distinct );
002834 testcase( pKeyInfo==0 ); /* Caused by OOM in sqlite3KeyInfoAlloc() */
002835 if( sqlite3Select(pParse, pSelect, &dest) ){
002836 sqlite3DbFree(pParse->db, dest.zAffSdst);
002837 sqlite3KeyInfoUnref(pKeyInfo);
002838 return;
002839 }
002840 sqlite3DbFree(pParse->db, dest.zAffSdst);
002841 assert( pKeyInfo!=0 ); /* OOM will cause exit after sqlite3Select() */
002842 assert( pEList!=0 );
002843 assert( pEList->nExpr>0 );
002844 assert( sqlite3KeyInfoIsWriteable(pKeyInfo) );
002845 for(i=0; i<nVal; i++){
002846 Expr *p = sqlite3VectorFieldSubexpr(pLeft, i);
002847 pKeyInfo->aColl[i] = sqlite3BinaryCompareCollSeq(
002848 pParse, p, pEList->a[i].pExpr
002849 );
002850 }
002851 }
002852 }else if( ALWAYS(pExpr->x.pList!=0) ){
002853 /* Case 2: expr IN (exprlist)
002854 **
002855 ** For each expression, build an index key from the evaluation and
002856 ** store it in the temporary table. If <expr> is a column, then use
002857 ** that columns affinity when building index keys. If <expr> is not
002858 ** a column, use numeric affinity.
002859 */
002860 char affinity; /* Affinity of the LHS of the IN */
002861 int i;
002862 ExprList *pList = pExpr->x.pList;
002863 struct ExprList_item *pItem;
002864 int r1, r2;
002865 affinity = sqlite3ExprAffinity(pLeft);
002866 if( affinity<=SQLITE_AFF_NONE ){
002867 affinity = SQLITE_AFF_BLOB;
002868 }
002869 if( pKeyInfo ){
002870 assert( sqlite3KeyInfoIsWriteable(pKeyInfo) );
002871 pKeyInfo->aColl[0] = sqlite3ExprCollSeq(pParse, pExpr->pLeft);
002872 }
002873
002874 /* Loop through each expression in <exprlist>. */
002875 r1 = sqlite3GetTempReg(pParse);
002876 r2 = sqlite3GetTempReg(pParse);
002877 for(i=pList->nExpr, pItem=pList->a; i>0; i--, pItem++){
002878 Expr *pE2 = pItem->pExpr;
002879
002880 /* If the expression is not constant then we will need to
002881 ** disable the test that was generated above that makes sure
002882 ** this code only executes once. Because for a non-constant
002883 ** expression we need to rerun this code each time.
002884 */
002885 if( addrOnce && !sqlite3ExprIsConstant(pE2) ){
002886 sqlite3VdbeChangeToNoop(v, addrOnce);
002887 ExprClearProperty(pExpr, EP_Subrtn);
002888 addrOnce = 0;
002889 }
002890
002891 /* Evaluate the expression and insert it into the temp table */
002892 sqlite3ExprCode(pParse, pE2, r1);
002893 sqlite3VdbeAddOp4(v, OP_MakeRecord, r1, 1, r2, &affinity, 1);
002894 sqlite3VdbeAddOp4Int(v, OP_IdxInsert, iTab, r2, r1, 1);
002895 }
002896 sqlite3ReleaseTempReg(pParse, r1);
002897 sqlite3ReleaseTempReg(pParse, r2);
002898 }
002899 if( pKeyInfo ){
002900 sqlite3VdbeChangeP4(v, addr, (void *)pKeyInfo, P4_KEYINFO);
002901 }
002902 if( addrOnce ){
002903 sqlite3VdbeJumpHere(v, addrOnce);
002904 /* Subroutine return */
002905 sqlite3VdbeAddOp1(v, OP_Return, pExpr->y.sub.regReturn);
002906 sqlite3VdbeChangeP1(v, pExpr->y.sub.iAddr-1, sqlite3VdbeCurrentAddr(v)-1);
002907 sqlite3ClearTempRegCache(pParse);
002908 }
002909 }
002910 #endif /* SQLITE_OMIT_SUBQUERY */
002911
002912 /*
002913 ** Generate code for scalar subqueries used as a subquery expression
002914 ** or EXISTS operator:
002915 **
002916 ** (SELECT a FROM b) -- subquery
002917 ** EXISTS (SELECT a FROM b) -- EXISTS subquery
002918 **
002919 ** The pExpr parameter is the SELECT or EXISTS operator to be coded.
002920 **
002921 ** Return the register that holds the result. For a multi-column SELECT,
002922 ** the result is stored in a contiguous array of registers and the
002923 ** return value is the register of the left-most result column.
002924 ** Return 0 if an error occurs.
002925 */
002926 #ifndef SQLITE_OMIT_SUBQUERY
002927 int sqlite3CodeSubselect(Parse *pParse, Expr *pExpr){
002928 int addrOnce = 0; /* Address of OP_Once at top of subroutine */
002929 int rReg = 0; /* Register storing resulting */
002930 Select *pSel; /* SELECT statement to encode */
002931 SelectDest dest; /* How to deal with SELECT result */
002932 int nReg; /* Registers to allocate */
002933 Expr *pLimit; /* New limit expression */
002934
002935 Vdbe *v = pParse->pVdbe;
002936 assert( v!=0 );
002937 testcase( pExpr->op==TK_EXISTS );
002938 testcase( pExpr->op==TK_SELECT );
002939 assert( pExpr->op==TK_EXISTS || pExpr->op==TK_SELECT );
002940 assert( ExprHasProperty(pExpr, EP_xIsSelect) );
002941 pSel = pExpr->x.pSelect;
002942
002943 /* The evaluation of the EXISTS/SELECT must be repeated every time it
002944 ** is encountered if any of the following is true:
002945 **
002946 ** * The right-hand side is a correlated subquery
002947 ** * The right-hand side is an expression list containing variables
002948 ** * We are inside a trigger
002949 **
002950 ** If all of the above are false, then we can run this code just once
002951 ** save the results, and reuse the same result on subsequent invocations.
002952 */
002953 if( !ExprHasProperty(pExpr, EP_VarSelect) ){
002954 /* If this routine has already been coded, then invoke it as a
002955 ** subroutine. */
002956 if( ExprHasProperty(pExpr, EP_Subrtn) ){
002957 ExplainQueryPlan((pParse, 0, "REUSE SUBQUERY %d", pSel->selId));
002958 sqlite3VdbeAddOp2(v, OP_Gosub, pExpr->y.sub.regReturn,
002959 pExpr->y.sub.iAddr);
002960 return pExpr->iTable;
002961 }
002962
002963 /* Begin coding the subroutine */
002964 ExprSetProperty(pExpr, EP_Subrtn);
002965 pExpr->y.sub.regReturn = ++pParse->nMem;
002966 pExpr->y.sub.iAddr =
002967 sqlite3VdbeAddOp2(v, OP_Integer, 0, pExpr->y.sub.regReturn) + 1;
002968 VdbeComment((v, "return address"));
002969
002970 addrOnce = sqlite3VdbeAddOp0(v, OP_Once); VdbeCoverage(v);
002971 }
002972
002973 /* For a SELECT, generate code to put the values for all columns of
002974 ** the first row into an array of registers and return the index of
002975 ** the first register.
002976 **
002977 ** If this is an EXISTS, write an integer 0 (not exists) or 1 (exists)
002978 ** into a register and return that register number.
002979 **
002980 ** In both cases, the query is augmented with "LIMIT 1". Any
002981 ** preexisting limit is discarded in place of the new LIMIT 1.
002982 */
002983 ExplainQueryPlan((pParse, 1, "%sSCALAR SUBQUERY %d",
002984 addrOnce?"":"CORRELATED ", pSel->selId));
002985 nReg = pExpr->op==TK_SELECT ? pSel->pEList->nExpr : 1;
002986 sqlite3SelectDestInit(&dest, 0, pParse->nMem+1);
002987 pParse->nMem += nReg;
002988 if( pExpr->op==TK_SELECT ){
002989 dest.eDest = SRT_Mem;
002990 dest.iSdst = dest.iSDParm;
002991 dest.nSdst = nReg;
002992 sqlite3VdbeAddOp3(v, OP_Null, 0, dest.iSDParm, dest.iSDParm+nReg-1);
002993 VdbeComment((v, "Init subquery result"));
002994 }else{
002995 dest.eDest = SRT_Exists;
002996 sqlite3VdbeAddOp2(v, OP_Integer, 0, dest.iSDParm);
002997 VdbeComment((v, "Init EXISTS result"));
002998 }
002999 if( pSel->pLimit ){
003000 /* The subquery already has a limit. If the pre-existing limit is X
003001 ** then make the new limit X<>0 so that the new limit is either 1 or 0 */
003002 sqlite3 *db = pParse->db;
003003 pLimit = sqlite3Expr(db, TK_INTEGER, "0");
003004 if( pLimit ){
003005 pLimit->affExpr = SQLITE_AFF_NUMERIC;
003006 pLimit = sqlite3PExpr(pParse, TK_NE,
003007 sqlite3ExprDup(db, pSel->pLimit->pLeft, 0), pLimit);
003008 }
003009 sqlite3ExprDelete(db, pSel->pLimit->pLeft);
003010 pSel->pLimit->pLeft = pLimit;
003011 }else{
003012 /* If there is no pre-existing limit add a limit of 1 */
003013 pLimit = sqlite3Expr(pParse->db, TK_INTEGER, "1");
003014 pSel->pLimit = sqlite3PExpr(pParse, TK_LIMIT, pLimit, 0);
003015 }
003016 pSel->iLimit = 0;
003017 if( sqlite3Select(pParse, pSel, &dest) ){
003018 return 0;
003019 }
003020 pExpr->iTable = rReg = dest.iSDParm;
003021 ExprSetVVAProperty(pExpr, EP_NoReduce);
003022 if( addrOnce ){
003023 sqlite3VdbeJumpHere(v, addrOnce);
003024
003025 /* Subroutine return */
003026 sqlite3VdbeAddOp1(v, OP_Return, pExpr->y.sub.regReturn);
003027 sqlite3VdbeChangeP1(v, pExpr->y.sub.iAddr-1, sqlite3VdbeCurrentAddr(v)-1);
003028 sqlite3ClearTempRegCache(pParse);
003029 }
003030
003031 return rReg;
003032 }
003033 #endif /* SQLITE_OMIT_SUBQUERY */
003034
003035 #ifndef SQLITE_OMIT_SUBQUERY
003036 /*
003037 ** Expr pIn is an IN(...) expression. This function checks that the
003038 ** sub-select on the RHS of the IN() operator has the same number of
003039 ** columns as the vector on the LHS. Or, if the RHS of the IN() is not
003040 ** a sub-query, that the LHS is a vector of size 1.
003041 */
003042 int sqlite3ExprCheckIN(Parse *pParse, Expr *pIn){
003043 int nVector = sqlite3ExprVectorSize(pIn->pLeft);
003044 if( (pIn->flags & EP_xIsSelect) ){
003045 if( nVector!=pIn->x.pSelect->pEList->nExpr ){
003046 sqlite3SubselectError(pParse, pIn->x.pSelect->pEList->nExpr, nVector);
003047 return 1;
003048 }
003049 }else if( nVector!=1 ){
003050 sqlite3VectorErrorMsg(pParse, pIn->pLeft);
003051 return 1;
003052 }
003053 return 0;
003054 }
003055 #endif
003056
003057 #ifndef SQLITE_OMIT_SUBQUERY
003058 /*
003059 ** Generate code for an IN expression.
003060 **
003061 ** x IN (SELECT ...)
003062 ** x IN (value, value, ...)
003063 **
003064 ** The left-hand side (LHS) is a scalar or vector expression. The
003065 ** right-hand side (RHS) is an array of zero or more scalar values, or a
003066 ** subquery. If the RHS is a subquery, the number of result columns must
003067 ** match the number of columns in the vector on the LHS. If the RHS is
003068 ** a list of values, the LHS must be a scalar.
003069 **
003070 ** The IN operator is true if the LHS value is contained within the RHS.
003071 ** The result is false if the LHS is definitely not in the RHS. The
003072 ** result is NULL if the presence of the LHS in the RHS cannot be
003073 ** determined due to NULLs.
003074 **
003075 ** This routine generates code that jumps to destIfFalse if the LHS is not
003076 ** contained within the RHS. If due to NULLs we cannot determine if the LHS
003077 ** is contained in the RHS then jump to destIfNull. If the LHS is contained
003078 ** within the RHS then fall through.
003079 **
003080 ** See the separate in-operator.md documentation file in the canonical
003081 ** SQLite source tree for additional information.
003082 */
003083 static void sqlite3ExprCodeIN(
003084 Parse *pParse, /* Parsing and code generating context */
003085 Expr *pExpr, /* The IN expression */
003086 int destIfFalse, /* Jump here if LHS is not contained in the RHS */
003087 int destIfNull /* Jump here if the results are unknown due to NULLs */
003088 ){
003089 int rRhsHasNull = 0; /* Register that is true if RHS contains NULL values */
003090 int eType; /* Type of the RHS */
003091 int rLhs; /* Register(s) holding the LHS values */
003092 int rLhsOrig; /* LHS values prior to reordering by aiMap[] */
003093 Vdbe *v; /* Statement under construction */
003094 int *aiMap = 0; /* Map from vector field to index column */
003095 char *zAff = 0; /* Affinity string for comparisons */
003096 int nVector; /* Size of vectors for this IN operator */
003097 int iDummy; /* Dummy parameter to exprCodeVector() */
003098 Expr *pLeft; /* The LHS of the IN operator */
003099 int i; /* loop counter */
003100 int destStep2; /* Where to jump when NULLs seen in step 2 */
003101 int destStep6 = 0; /* Start of code for Step 6 */
003102 int addrTruthOp; /* Address of opcode that determines the IN is true */
003103 int destNotNull; /* Jump here if a comparison is not true in step 6 */
003104 int addrTop; /* Top of the step-6 loop */
003105 int iTab = 0; /* Index to use */
003106
003107 pLeft = pExpr->pLeft;
003108 if( sqlite3ExprCheckIN(pParse, pExpr) ) return;
003109 zAff = exprINAffinity(pParse, pExpr);
003110 nVector = sqlite3ExprVectorSize(pExpr->pLeft);
003111 aiMap = (int*)sqlite3DbMallocZero(
003112 pParse->db, nVector*(sizeof(int) + sizeof(char)) + 1
003113 );
003114 if( pParse->db->mallocFailed ) goto sqlite3ExprCodeIN_oom_error;
003115
003116 /* Attempt to compute the RHS. After this step, if anything other than
003117 ** IN_INDEX_NOOP is returned, the table opened with cursor iTab
003118 ** contains the values that make up the RHS. If IN_INDEX_NOOP is returned,
003119 ** the RHS has not yet been coded. */
003120 v = pParse->pVdbe;
003121 assert( v!=0 ); /* OOM detected prior to this routine */
003122 VdbeNoopComment((v, "begin IN expr"));
003123 eType = sqlite3FindInIndex(pParse, pExpr,
003124 IN_INDEX_MEMBERSHIP | IN_INDEX_NOOP_OK,
003125 destIfFalse==destIfNull ? 0 : &rRhsHasNull,
003126 aiMap, &iTab);
003127
003128 assert( pParse->nErr || nVector==1 || eType==IN_INDEX_EPH
003129 || eType==IN_INDEX_INDEX_ASC || eType==IN_INDEX_INDEX_DESC
003130 );
003131 #ifdef SQLITE_DEBUG
003132 /* Confirm that aiMap[] contains nVector integer values between 0 and
003133 ** nVector-1. */
003134 for(i=0; i<nVector; i++){
003135 int j, cnt;
003136 for(cnt=j=0; j<nVector; j++) if( aiMap[j]==i ) cnt++;
003137 assert( cnt==1 );
003138 }
003139 #endif
003140
003141 /* Code the LHS, the <expr> from "<expr> IN (...)". If the LHS is a
003142 ** vector, then it is stored in an array of nVector registers starting
003143 ** at r1.
003144 **
003145 ** sqlite3FindInIndex() might have reordered the fields of the LHS vector
003146 ** so that the fields are in the same order as an existing index. The
003147 ** aiMap[] array contains a mapping from the original LHS field order to
003148 ** the field order that matches the RHS index.
003149 */
003150 rLhsOrig = exprCodeVector(pParse, pLeft, &iDummy);
003151 for(i=0; i<nVector && aiMap[i]==i; i++){} /* Are LHS fields reordered? */
003152 if( i==nVector ){
003153 /* LHS fields are not reordered */
003154 rLhs = rLhsOrig;
003155 }else{
003156 /* Need to reorder the LHS fields according to aiMap */
003157 rLhs = sqlite3GetTempRange(pParse, nVector);
003158 for(i=0; i<nVector; i++){
003159 sqlite3VdbeAddOp3(v, OP_Copy, rLhsOrig+i, rLhs+aiMap[i], 0);
003160 }
003161 }
003162
003163 /* If sqlite3FindInIndex() did not find or create an index that is
003164 ** suitable for evaluating the IN operator, then evaluate using a
003165 ** sequence of comparisons.
003166 **
003167 ** This is step (1) in the in-operator.md optimized algorithm.
003168 */
003169 if( eType==IN_INDEX_NOOP ){
003170 ExprList *pList = pExpr->x.pList;
003171 CollSeq *pColl = sqlite3ExprCollSeq(pParse, pExpr->pLeft);
003172 int labelOk = sqlite3VdbeMakeLabel(pParse);
003173 int r2, regToFree;
003174 int regCkNull = 0;
003175 int ii;
003176 int bLhsReal; /* True if the LHS of the IN has REAL affinity */
003177 assert( !ExprHasProperty(pExpr, EP_xIsSelect) );
003178 if( destIfNull!=destIfFalse ){
003179 regCkNull = sqlite3GetTempReg(pParse);
003180 sqlite3VdbeAddOp3(v, OP_BitAnd, rLhs, rLhs, regCkNull);
003181 }
003182 bLhsReal = sqlite3ExprAffinity(pExpr->pLeft)==SQLITE_AFF_REAL;
003183 for(ii=0; ii<pList->nExpr; ii++){
003184 if( bLhsReal ){
003185 r2 = regToFree = sqlite3GetTempReg(pParse);
003186 sqlite3ExprCode(pParse, pList->a[ii].pExpr, r2);
003187 sqlite3VdbeAddOp4(v, OP_Affinity, r2, 1, 0, "E", P4_STATIC);
003188 }else{
003189 r2 = sqlite3ExprCodeTemp(pParse, pList->a[ii].pExpr, ®ToFree);
003190 }
003191 if( regCkNull && sqlite3ExprCanBeNull(pList->a[ii].pExpr) ){
003192 sqlite3VdbeAddOp3(v, OP_BitAnd, regCkNull, r2, regCkNull);
003193 }
003194 if( ii<pList->nExpr-1 || destIfNull!=destIfFalse ){
003195 int op = rLhs!=r2 ? OP_Eq : OP_NotNull;
003196 sqlite3VdbeAddOp4(v, op, rLhs, labelOk, r2,
003197 (void*)pColl, P4_COLLSEQ);
003198 VdbeCoverageIf(v, ii<pList->nExpr-1 && op==OP_Eq);
003199 VdbeCoverageIf(v, ii==pList->nExpr-1 && op==OP_Eq);
003200 VdbeCoverageIf(v, ii<pList->nExpr-1 && op==OP_NotNull);
003201 VdbeCoverageIf(v, ii==pList->nExpr-1 && op==OP_NotNull);
003202 sqlite3VdbeChangeP5(v, zAff[0]);
003203 }else{
003204 int op = rLhs!=r2 ? OP_Ne : OP_IsNull;
003205 assert( destIfNull==destIfFalse );
003206 sqlite3VdbeAddOp4(v, op, rLhs, destIfFalse, r2,
003207 (void*)pColl, P4_COLLSEQ);
003208 VdbeCoverageIf(v, op==OP_Ne);
003209 VdbeCoverageIf(v, op==OP_IsNull);
003210 sqlite3VdbeChangeP5(v, zAff[0] | SQLITE_JUMPIFNULL);
003211 }
003212 sqlite3ReleaseTempReg(pParse, regToFree);
003213 }
003214 if( regCkNull ){
003215 sqlite3VdbeAddOp2(v, OP_IsNull, regCkNull, destIfNull); VdbeCoverage(v);
003216 sqlite3VdbeGoto(v, destIfFalse);
003217 }
003218 sqlite3VdbeResolveLabel(v, labelOk);
003219 sqlite3ReleaseTempReg(pParse, regCkNull);
003220 goto sqlite3ExprCodeIN_finished;
003221 }
003222
003223 /* Step 2: Check to see if the LHS contains any NULL columns. If the
003224 ** LHS does contain NULLs then the result must be either FALSE or NULL.
003225 ** We will then skip the binary search of the RHS.
003226 */
003227 if( destIfNull==destIfFalse ){
003228 destStep2 = destIfFalse;
003229 }else{
003230 destStep2 = destStep6 = sqlite3VdbeMakeLabel(pParse);
003231 }
003232 if( pParse->nErr ) goto sqlite3ExprCodeIN_finished;
003233 for(i=0; i<nVector; i++){
003234 Expr *p = sqlite3VectorFieldSubexpr(pExpr->pLeft, i);
003235 if( sqlite3ExprCanBeNull(p) ){
003236 sqlite3VdbeAddOp2(v, OP_IsNull, rLhs+i, destStep2);
003237 VdbeCoverage(v);
003238 }
003239 }
003240
003241 /* Step 3. The LHS is now known to be non-NULL. Do the binary search
003242 ** of the RHS using the LHS as a probe. If found, the result is
003243 ** true.
003244 */
003245 if( eType==IN_INDEX_ROWID ){
003246 /* In this case, the RHS is the ROWID of table b-tree and so we also
003247 ** know that the RHS is non-NULL. Hence, we combine steps 3 and 4
003248 ** into a single opcode. */
003249 sqlite3VdbeAddOp3(v, OP_SeekRowid, iTab, destIfFalse, rLhs);
003250 VdbeCoverage(v);
003251 addrTruthOp = sqlite3VdbeAddOp0(v, OP_Goto); /* Return True */
003252 }else{
003253 sqlite3VdbeAddOp4(v, OP_Affinity, rLhs, nVector, 0, zAff, nVector);
003254 if( destIfFalse==destIfNull ){
003255 /* Combine Step 3 and Step 5 into a single opcode */
003256 sqlite3VdbeAddOp4Int(v, OP_NotFound, iTab, destIfFalse,
003257 rLhs, nVector); VdbeCoverage(v);
003258 goto sqlite3ExprCodeIN_finished;
003259 }
003260 /* Ordinary Step 3, for the case where FALSE and NULL are distinct */
003261 addrTruthOp = sqlite3VdbeAddOp4Int(v, OP_Found, iTab, 0,
003262 rLhs, nVector); VdbeCoverage(v);
003263 }
003264
003265 /* Step 4. If the RHS is known to be non-NULL and we did not find
003266 ** an match on the search above, then the result must be FALSE.
003267 */
003268 if( rRhsHasNull && nVector==1 ){
003269 sqlite3VdbeAddOp2(v, OP_NotNull, rRhsHasNull, destIfFalse);
003270 VdbeCoverage(v);
003271 }
003272
003273 /* Step 5. If we do not care about the difference between NULL and
003274 ** FALSE, then just return false.
003275 */
003276 if( destIfFalse==destIfNull ) sqlite3VdbeGoto(v, destIfFalse);
003277
003278 /* Step 6: Loop through rows of the RHS. Compare each row to the LHS.
003279 ** If any comparison is NULL, then the result is NULL. If all
003280 ** comparisons are FALSE then the final result is FALSE.
003281 **
003282 ** For a scalar LHS, it is sufficient to check just the first row
003283 ** of the RHS.
003284 */
003285 if( destStep6 ) sqlite3VdbeResolveLabel(v, destStep6);
003286 addrTop = sqlite3VdbeAddOp2(v, OP_Rewind, iTab, destIfFalse);
003287 VdbeCoverage(v);
003288 if( nVector>1 ){
003289 destNotNull = sqlite3VdbeMakeLabel(pParse);
003290 }else{
003291 /* For nVector==1, combine steps 6 and 7 by immediately returning
003292 ** FALSE if the first comparison is not NULL */
003293 destNotNull = destIfFalse;
003294 }
003295 for(i=0; i<nVector; i++){
003296 Expr *p;
003297 CollSeq *pColl;
003298 int r3 = sqlite3GetTempReg(pParse);
003299 p = sqlite3VectorFieldSubexpr(pLeft, i);
003300 pColl = sqlite3ExprCollSeq(pParse, p);
003301 sqlite3VdbeAddOp3(v, OP_Column, iTab, i, r3);
003302 sqlite3VdbeAddOp4(v, OP_Ne, rLhs+i, destNotNull, r3,
003303 (void*)pColl, P4_COLLSEQ);
003304 VdbeCoverage(v);
003305 sqlite3ReleaseTempReg(pParse, r3);
003306 }
003307 sqlite3VdbeAddOp2(v, OP_Goto, 0, destIfNull);
003308 if( nVector>1 ){
003309 sqlite3VdbeResolveLabel(v, destNotNull);
003310 sqlite3VdbeAddOp2(v, OP_Next, iTab, addrTop+1);
003311 VdbeCoverage(v);
003312
003313 /* Step 7: If we reach this point, we know that the result must
003314 ** be false. */
003315 sqlite3VdbeAddOp2(v, OP_Goto, 0, destIfFalse);
003316 }
003317
003318 /* Jumps here in order to return true. */
003319 sqlite3VdbeJumpHere(v, addrTruthOp);
003320
003321 sqlite3ExprCodeIN_finished:
003322 if( rLhs!=rLhsOrig ) sqlite3ReleaseTempReg(pParse, rLhs);
003323 VdbeComment((v, "end IN expr"));
003324 sqlite3ExprCodeIN_oom_error:
003325 sqlite3DbFree(pParse->db, aiMap);
003326 sqlite3DbFree(pParse->db, zAff);
003327 }
003328 #endif /* SQLITE_OMIT_SUBQUERY */
003329
003330 #ifndef SQLITE_OMIT_FLOATING_POINT
003331 /*
003332 ** Generate an instruction that will put the floating point
003333 ** value described by z[0..n-1] into register iMem.
003334 **
003335 ** The z[] string will probably not be zero-terminated. But the
003336 ** z[n] character is guaranteed to be something that does not look
003337 ** like the continuation of the number.
003338 */
003339 static void codeReal(Vdbe *v, const char *z, int negateFlag, int iMem){
003340 if( ALWAYS(z!=0) ){
003341 double value;
003342 sqlite3AtoF(z, &value, sqlite3Strlen30(z), SQLITE_UTF8);
003343 assert( !sqlite3IsNaN(value) ); /* The new AtoF never returns NaN */
003344 if( negateFlag ) value = -value;
003345 sqlite3VdbeAddOp4Dup8(v, OP_Real, 0, iMem, 0, (u8*)&value, P4_REAL);
003346 }
003347 }
003348 #endif
003349
003350
003351 /*
003352 ** Generate an instruction that will put the integer describe by
003353 ** text z[0..n-1] into register iMem.
003354 **
003355 ** Expr.u.zToken is always UTF8 and zero-terminated.
003356 */
003357 static void codeInteger(Parse *pParse, Expr *pExpr, int negFlag, int iMem){
003358 Vdbe *v = pParse->pVdbe;
003359 if( pExpr->flags & EP_IntValue ){
003360 int i = pExpr->u.iValue;
003361 assert( i>=0 );
003362 if( negFlag ) i = -i;
003363 sqlite3VdbeAddOp2(v, OP_Integer, i, iMem);
003364 }else{
003365 int c;
003366 i64 value;
003367 const char *z = pExpr->u.zToken;
003368 assert( z!=0 );
003369 c = sqlite3DecOrHexToI64(z, &value);
003370 if( (c==3 && !negFlag) || (c==2) || (negFlag && value==SMALLEST_INT64)){
003371 #ifdef SQLITE_OMIT_FLOATING_POINT
003372 sqlite3ErrorMsg(pParse, "oversized integer: %s%s", negFlag ? "-" : "", z);
003373 #else
003374 #ifndef SQLITE_OMIT_HEX_INTEGER
003375 if( sqlite3_strnicmp(z,"0x",2)==0 ){
003376 sqlite3ErrorMsg(pParse, "hex literal too big: %s%s", negFlag?"-":"",z);
003377 }else
003378 #endif
003379 {
003380 codeReal(v, z, negFlag, iMem);
003381 }
003382 #endif
003383 }else{
003384 if( negFlag ){ value = c==3 ? SMALLEST_INT64 : -value; }
003385 sqlite3VdbeAddOp4Dup8(v, OP_Int64, 0, iMem, 0, (u8*)&value, P4_INT64);
003386 }
003387 }
003388 }
003389
003390
003391 /* Generate code that will load into register regOut a value that is
003392 ** appropriate for the iIdxCol-th column of index pIdx.
003393 */
003394 void sqlite3ExprCodeLoadIndexColumn(
003395 Parse *pParse, /* The parsing context */
003396 Index *pIdx, /* The index whose column is to be loaded */
003397 int iTabCur, /* Cursor pointing to a table row */
003398 int iIdxCol, /* The column of the index to be loaded */
003399 int regOut /* Store the index column value in this register */
003400 ){
003401 i16 iTabCol = pIdx->aiColumn[iIdxCol];
003402 if( iTabCol==XN_EXPR ){
003403 assert( pIdx->aColExpr );
003404 assert( pIdx->aColExpr->nExpr>iIdxCol );
003405 pParse->iSelfTab = iTabCur + 1;
003406 sqlite3ExprCodeCopy(pParse, pIdx->aColExpr->a[iIdxCol].pExpr, regOut);
003407 pParse->iSelfTab = 0;
003408 }else{
003409 sqlite3ExprCodeGetColumnOfTable(pParse->pVdbe, pIdx->pTable, iTabCur,
003410 iTabCol, regOut);
003411 }
003412 }
003413
003414 #ifndef SQLITE_OMIT_GENERATED_COLUMNS
003415 /*
003416 ** Generate code that will compute the value of generated column pCol
003417 ** and store the result in register regOut
003418 */
003419 void sqlite3ExprCodeGeneratedColumn(
003420 Parse *pParse,
003421 Column *pCol,
003422 int regOut
003423 ){
003424 int iAddr;
003425 Vdbe *v = pParse->pVdbe;
003426 assert( v!=0 );
003427 assert( pParse->iSelfTab!=0 );
003428 if( pParse->iSelfTab>0 ){
003429 iAddr = sqlite3VdbeAddOp3(v, OP_IfNullRow, pParse->iSelfTab-1, 0, regOut);
003430 }else{
003431 iAddr = 0;
003432 }
003433 sqlite3ExprCode(pParse, pCol->pDflt, regOut);
003434 if( pCol->affinity>=SQLITE_AFF_TEXT ){
003435 sqlite3VdbeAddOp4(v, OP_Affinity, regOut, 1, 0, &pCol->affinity, 1);
003436 }
003437 if( iAddr ) sqlite3VdbeJumpHere(v, iAddr);
003438 }
003439 #endif /* SQLITE_OMIT_GENERATED_COLUMNS */
003440
003441 /*
003442 ** Generate code to extract the value of the iCol-th column of a table.
003443 */
003444 void sqlite3ExprCodeGetColumnOfTable(
003445 Vdbe *v, /* Parsing context */
003446 Table *pTab, /* The table containing the value */
003447 int iTabCur, /* The table cursor. Or the PK cursor for WITHOUT ROWID */
003448 int iCol, /* Index of the column to extract */
003449 int regOut /* Extract the value into this register */
003450 ){
003451 Column *pCol;
003452 assert( v!=0 );
003453 if( pTab==0 ){
003454 sqlite3VdbeAddOp3(v, OP_Column, iTabCur, iCol, regOut);
003455 return;
003456 }
003457 if( iCol<0 || iCol==pTab->iPKey ){
003458 sqlite3VdbeAddOp2(v, OP_Rowid, iTabCur, regOut);
003459 }else{
003460 int op;
003461 int x;
003462 if( IsVirtual(pTab) ){
003463 op = OP_VColumn;
003464 x = iCol;
003465 #ifndef SQLITE_OMIT_GENERATED_COLUMNS
003466 }else if( (pCol = &pTab->aCol[iCol])->colFlags & COLFLAG_VIRTUAL ){
003467 Parse *pParse = sqlite3VdbeParser(v);
003468 if( pCol->colFlags & COLFLAG_BUSY ){
003469 sqlite3ErrorMsg(pParse, "generated column loop on \"%s\"", pCol->zName);
003470 }else{
003471 int savedSelfTab = pParse->iSelfTab;
003472 pCol->colFlags |= COLFLAG_BUSY;
003473 pParse->iSelfTab = iTabCur+1;
003474 sqlite3ExprCodeGeneratedColumn(pParse, pCol, regOut);
003475 pParse->iSelfTab = savedSelfTab;
003476 pCol->colFlags &= ~COLFLAG_BUSY;
003477 }
003478 return;
003479 #endif
003480 }else if( !HasRowid(pTab) ){
003481 testcase( iCol!=sqlite3TableColumnToStorage(pTab, iCol) );
003482 x = sqlite3TableColumnToIndex(sqlite3PrimaryKeyIndex(pTab), iCol);
003483 op = OP_Column;
003484 }else{
003485 x = sqlite3TableColumnToStorage(pTab,iCol);
003486 testcase( x!=iCol );
003487 op = OP_Column;
003488 }
003489 sqlite3VdbeAddOp3(v, op, iTabCur, x, regOut);
003490 sqlite3ColumnDefault(v, pTab, iCol, regOut);
003491 }
003492 }
003493
003494 /*
003495 ** Generate code that will extract the iColumn-th column from
003496 ** table pTab and store the column value in register iReg.
003497 **
003498 ** There must be an open cursor to pTab in iTable when this routine
003499 ** is called. If iColumn<0 then code is generated that extracts the rowid.
003500 */
003501 int sqlite3ExprCodeGetColumn(
003502 Parse *pParse, /* Parsing and code generating context */
003503 Table *pTab, /* Description of the table we are reading from */
003504 int iColumn, /* Index of the table column */
003505 int iTable, /* The cursor pointing to the table */
003506 int iReg, /* Store results here */
003507 u8 p5 /* P5 value for OP_Column + FLAGS */
003508 ){
003509 assert( pParse->pVdbe!=0 );
003510 sqlite3ExprCodeGetColumnOfTable(pParse->pVdbe, pTab, iTable, iColumn, iReg);
003511 if( p5 ){
003512 VdbeOp *pOp = sqlite3VdbeGetOp(pParse->pVdbe,-1);
003513 if( pOp->opcode==OP_Column ) pOp->p5 = p5;
003514 }
003515 return iReg;
003516 }
003517
003518 /*
003519 ** Generate code to move content from registers iFrom...iFrom+nReg-1
003520 ** over to iTo..iTo+nReg-1.
003521 */
003522 void sqlite3ExprCodeMove(Parse *pParse, int iFrom, int iTo, int nReg){
003523 sqlite3VdbeAddOp3(pParse->pVdbe, OP_Move, iFrom, iTo, nReg);
003524 }
003525
003526 /*
003527 ** Convert a scalar expression node to a TK_REGISTER referencing
003528 ** register iReg. The caller must ensure that iReg already contains
003529 ** the correct value for the expression.
003530 */
003531 static void exprToRegister(Expr *pExpr, int iReg){
003532 Expr *p = sqlite3ExprSkipCollateAndLikely(pExpr);
003533 p->op2 = p->op;
003534 p->op = TK_REGISTER;
003535 p->iTable = iReg;
003536 ExprClearProperty(p, EP_Skip);
003537 }
003538
003539 /*
003540 ** Evaluate an expression (either a vector or a scalar expression) and store
003541 ** the result in continguous temporary registers. Return the index of
003542 ** the first register used to store the result.
003543 **
003544 ** If the returned result register is a temporary scalar, then also write
003545 ** that register number into *piFreeable. If the returned result register
003546 ** is not a temporary or if the expression is a vector set *piFreeable
003547 ** to 0.
003548 */
003549 static int exprCodeVector(Parse *pParse, Expr *p, int *piFreeable){
003550 int iResult;
003551 int nResult = sqlite3ExprVectorSize(p);
003552 if( nResult==1 ){
003553 iResult = sqlite3ExprCodeTemp(pParse, p, piFreeable);
003554 }else{
003555 *piFreeable = 0;
003556 if( p->op==TK_SELECT ){
003557 #if SQLITE_OMIT_SUBQUERY
003558 iResult = 0;
003559 #else
003560 iResult = sqlite3CodeSubselect(pParse, p);
003561 #endif
003562 }else{
003563 int i;
003564 iResult = pParse->nMem+1;
003565 pParse->nMem += nResult;
003566 for(i=0; i<nResult; i++){
003567 sqlite3ExprCodeFactorable(pParse, p->x.pList->a[i].pExpr, i+iResult);
003568 }
003569 }
003570 }
003571 return iResult;
003572 }
003573
003574
003575 /*
003576 ** Generate code into the current Vdbe to evaluate the given
003577 ** expression. Attempt to store the results in register "target".
003578 ** Return the register where results are stored.
003579 **
003580 ** With this routine, there is no guarantee that results will
003581 ** be stored in target. The result might be stored in some other
003582 ** register if it is convenient to do so. The calling function
003583 ** must check the return code and move the results to the desired
003584 ** register.
003585 */
003586 int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target){
003587 Vdbe *v = pParse->pVdbe; /* The VM under construction */
003588 int op; /* The opcode being coded */
003589 int inReg = target; /* Results stored in register inReg */
003590 int regFree1 = 0; /* If non-zero free this temporary register */
003591 int regFree2 = 0; /* If non-zero free this temporary register */
003592 int r1, r2; /* Various register numbers */
003593 Expr tempX; /* Temporary expression node */
003594 int p5 = 0;
003595
003596 assert( target>0 && target<=pParse->nMem );
003597 if( v==0 ){
003598 assert( pParse->db->mallocFailed );
003599 return 0;
003600 }
003601
003602 expr_code_doover:
003603 if( pExpr==0 ){
003604 op = TK_NULL;
003605 }else{
003606 op = pExpr->op;
003607 }
003608 switch( op ){
003609 case TK_AGG_COLUMN: {
003610 AggInfo *pAggInfo = pExpr->pAggInfo;
003611 struct AggInfo_col *pCol = &pAggInfo->aCol[pExpr->iAgg];
003612 if( !pAggInfo->directMode ){
003613 assert( pCol->iMem>0 );
003614 return pCol->iMem;
003615 }else if( pAggInfo->useSortingIdx ){
003616 sqlite3VdbeAddOp3(v, OP_Column, pAggInfo->sortingIdxPTab,
003617 pCol->iSorterColumn, target);
003618 return target;
003619 }
003620 /* Otherwise, fall thru into the TK_COLUMN case */
003621 }
003622 case TK_COLUMN: {
003623 int iTab = pExpr->iTable;
003624 int iReg;
003625 if( ExprHasProperty(pExpr, EP_FixedCol) ){
003626 /* This COLUMN expression is really a constant due to WHERE clause
003627 ** constraints, and that constant is coded by the pExpr->pLeft
003628 ** expresssion. However, make sure the constant has the correct
003629 ** datatype by applying the Affinity of the table column to the
003630 ** constant.
003631 */
003632 int aff;
003633 iReg = sqlite3ExprCodeTarget(pParse, pExpr->pLeft,target);
003634 if( pExpr->y.pTab ){
003635 aff = sqlite3TableColumnAffinity(pExpr->y.pTab, pExpr->iColumn);
003636 }else{
003637 aff = pExpr->affExpr;
003638 }
003639 if( aff>SQLITE_AFF_BLOB ){
003640 static const char zAff[] = "B\000C\000D\000E";
003641 assert( SQLITE_AFF_BLOB=='A' );
003642 assert( SQLITE_AFF_TEXT=='B' );
003643 if( iReg!=target ){
003644 sqlite3VdbeAddOp2(v, OP_SCopy, iReg, target);
003645 iReg = target;
003646 }
003647 sqlite3VdbeAddOp4(v, OP_Affinity, iReg, 1, 0,
003648 &zAff[(aff-'B')*2], P4_STATIC);
003649 }
003650 return iReg;
003651 }
003652 if( iTab<0 ){
003653 if( pParse->iSelfTab<0 ){
003654 /* Other columns in the same row for CHECK constraints or
003655 ** generated columns or for inserting into partial index.
003656 ** The row is unpacked into registers beginning at
003657 ** 0-(pParse->iSelfTab). The rowid (if any) is in a register
003658 ** immediately prior to the first column.
003659 */
003660 Column *pCol;
003661 Table *pTab = pExpr->y.pTab;
003662 int iSrc;
003663 int iCol = pExpr->iColumn;
003664 assert( pTab!=0 );
003665 assert( iCol>=XN_ROWID );
003666 assert( iCol<pTab->nCol );
003667 if( iCol<0 ){
003668 return -1-pParse->iSelfTab;
003669 }
003670 pCol = pTab->aCol + iCol;
003671 testcase( iCol!=sqlite3TableColumnToStorage(pTab,iCol) );
003672 iSrc = sqlite3TableColumnToStorage(pTab, iCol) - pParse->iSelfTab;
003673 #ifndef SQLITE_OMIT_GENERATED_COLUMNS
003674 if( pCol->colFlags & COLFLAG_GENERATED ){
003675 if( pCol->colFlags & COLFLAG_BUSY ){
003676 sqlite3ErrorMsg(pParse, "generated column loop on \"%s\"",
003677 pCol->zName);
003678 return 0;
003679 }
003680 pCol->colFlags |= COLFLAG_BUSY;
003681 if( pCol->colFlags & COLFLAG_NOTAVAIL ){
003682 sqlite3ExprCodeGeneratedColumn(pParse, pCol, iSrc);
003683 }
003684 pCol->colFlags &= ~(COLFLAG_BUSY|COLFLAG_NOTAVAIL);
003685 return iSrc;
003686 }else
003687 #endif /* SQLITE_OMIT_GENERATED_COLUMNS */
003688 if( pCol->affinity==SQLITE_AFF_REAL ){
003689 sqlite3VdbeAddOp2(v, OP_SCopy, iSrc, target);
003690 sqlite3VdbeAddOp1(v, OP_RealAffinity, target);
003691 return target;
003692 }else{
003693 return iSrc;
003694 }
003695 }else{
003696 /* Coding an expression that is part of an index where column names
003697 ** in the index refer to the table to which the index belongs */
003698 iTab = pParse->iSelfTab - 1;
003699 }
003700 }
003701 iReg = sqlite3ExprCodeGetColumn(pParse, pExpr->y.pTab,
003702 pExpr->iColumn, iTab, target,
003703 pExpr->op2);
003704 if( pExpr->y.pTab==0 && pExpr->affExpr==SQLITE_AFF_REAL ){
003705 sqlite3VdbeAddOp1(v, OP_RealAffinity, iReg);
003706 }
003707 return iReg;
003708 }
003709 case TK_INTEGER: {
003710 codeInteger(pParse, pExpr, 0, target);
003711 return target;
003712 }
003713 case TK_TRUEFALSE: {
003714 sqlite3VdbeAddOp2(v, OP_Integer, sqlite3ExprTruthValue(pExpr), target);
003715 return target;
003716 }
003717 #ifndef SQLITE_OMIT_FLOATING_POINT
003718 case TK_FLOAT: {
003719 assert( !ExprHasProperty(pExpr, EP_IntValue) );
003720 codeReal(v, pExpr->u.zToken, 0, target);
003721 return target;
003722 }
003723 #endif
003724 case TK_STRING: {
003725 assert( !ExprHasProperty(pExpr, EP_IntValue) );
003726 sqlite3VdbeLoadString(v, target, pExpr->u.zToken);
003727 return target;
003728 }
003729 default: {
003730 /* Make NULL the default case so that if a bug causes an illegal
003731 ** Expr node to be passed into this function, it will be handled
003732 ** sanely and not crash. But keep the assert() to bring the problem
003733 ** to the attention of the developers. */
003734 assert( op==TK_NULL );
003735 sqlite3VdbeAddOp2(v, OP_Null, 0, target);
003736 return target;
003737 }
003738 #ifndef SQLITE_OMIT_BLOB_LITERAL
003739 case TK_BLOB: {
003740 int n;
003741 const char *z;
003742 char *zBlob;
003743 assert( !ExprHasProperty(pExpr, EP_IntValue) );
003744 assert( pExpr->u.zToken[0]=='x' || pExpr->u.zToken[0]=='X' );
003745 assert( pExpr->u.zToken[1]=='\'' );
003746 z = &pExpr->u.zToken[2];
003747 n = sqlite3Strlen30(z) - 1;
003748 assert( z[n]=='\'' );
003749 zBlob = sqlite3HexToBlob(sqlite3VdbeDb(v), z, n);
003750 sqlite3VdbeAddOp4(v, OP_Blob, n/2, target, 0, zBlob, P4_DYNAMIC);
003751 return target;
003752 }
003753 #endif
003754 case TK_VARIABLE: {
003755 assert( !ExprHasProperty(pExpr, EP_IntValue) );
003756 assert( pExpr->u.zToken!=0 );
003757 assert( pExpr->u.zToken[0]!=0 );
003758 sqlite3VdbeAddOp2(v, OP_Variable, pExpr->iColumn, target);
003759 if( pExpr->u.zToken[1]!=0 ){
003760 const char *z = sqlite3VListNumToName(pParse->pVList, pExpr->iColumn);
003761 assert( pExpr->u.zToken[0]=='?' || (z && !strcmp(pExpr->u.zToken, z)) );
003762 pParse->pVList[0] = 0; /* Indicate VList may no longer be enlarged */
003763 sqlite3VdbeAppendP4(v, (char*)z, P4_STATIC);
003764 }
003765 return target;
003766 }
003767 case TK_REGISTER: {
003768 return pExpr->iTable;
003769 }
003770 #ifndef SQLITE_OMIT_CAST
003771 case TK_CAST: {
003772 /* Expressions of the form: CAST(pLeft AS token) */
003773 inReg = sqlite3ExprCodeTarget(pParse, pExpr->pLeft, target);
003774 if( inReg!=target ){
003775 sqlite3VdbeAddOp2(v, OP_SCopy, inReg, target);
003776 inReg = target;
003777 }
003778 sqlite3VdbeAddOp2(v, OP_Cast, target,
003779 sqlite3AffinityType(pExpr->u.zToken, 0));
003780 return inReg;
003781 }
003782 #endif /* SQLITE_OMIT_CAST */
003783 case TK_IS:
003784 case TK_ISNOT:
003785 op = (op==TK_IS) ? TK_EQ : TK_NE;
003786 p5 = SQLITE_NULLEQ;
003787 /* fall-through */
003788 case TK_LT:
003789 case TK_LE:
003790 case TK_GT:
003791 case TK_GE:
003792 case TK_NE:
003793 case TK_EQ: {
003794 Expr *pLeft = pExpr->pLeft;
003795 if( sqlite3ExprIsVector(pLeft) ){
003796 codeVectorCompare(pParse, pExpr, target, op, p5);
003797 }else{
003798 r1 = sqlite3ExprCodeTemp(pParse, pLeft, ®Free1);
003799 r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, ®Free2);
003800 codeCompare(pParse, pLeft, pExpr->pRight, op,
003801 r1, r2, inReg, SQLITE_STOREP2 | p5,
003802 ExprHasProperty(pExpr,EP_Commuted));
003803 assert(TK_LT==OP_Lt); testcase(op==OP_Lt); VdbeCoverageIf(v,op==OP_Lt);
003804 assert(TK_LE==OP_Le); testcase(op==OP_Le); VdbeCoverageIf(v,op==OP_Le);
003805 assert(TK_GT==OP_Gt); testcase(op==OP_Gt); VdbeCoverageIf(v,op==OP_Gt);
003806 assert(TK_GE==OP_Ge); testcase(op==OP_Ge); VdbeCoverageIf(v,op==OP_Ge);
003807 assert(TK_EQ==OP_Eq); testcase(op==OP_Eq); VdbeCoverageIf(v,op==OP_Eq);
003808 assert(TK_NE==OP_Ne); testcase(op==OP_Ne); VdbeCoverageIf(v,op==OP_Ne);
003809 testcase( regFree1==0 );
003810 testcase( regFree2==0 );
003811 }
003812 break;
003813 }
003814 case TK_AND:
003815 case TK_OR:
003816 case TK_PLUS:
003817 case TK_STAR:
003818 case TK_MINUS:
003819 case TK_REM:
003820 case TK_BITAND:
003821 case TK_BITOR:
003822 case TK_SLASH:
003823 case TK_LSHIFT:
003824 case TK_RSHIFT:
003825 case TK_CONCAT: {
003826 assert( TK_AND==OP_And ); testcase( op==TK_AND );
003827 assert( TK_OR==OP_Or ); testcase( op==TK_OR );
003828 assert( TK_PLUS==OP_Add ); testcase( op==TK_PLUS );
003829 assert( TK_MINUS==OP_Subtract ); testcase( op==TK_MINUS );
003830 assert( TK_REM==OP_Remainder ); testcase( op==TK_REM );
003831 assert( TK_BITAND==OP_BitAnd ); testcase( op==TK_BITAND );
003832 assert( TK_BITOR==OP_BitOr ); testcase( op==TK_BITOR );
003833 assert( TK_SLASH==OP_Divide ); testcase( op==TK_SLASH );
003834 assert( TK_LSHIFT==OP_ShiftLeft ); testcase( op==TK_LSHIFT );
003835 assert( TK_RSHIFT==OP_ShiftRight ); testcase( op==TK_RSHIFT );
003836 assert( TK_CONCAT==OP_Concat ); testcase( op==TK_CONCAT );
003837 r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free1);
003838 r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, ®Free2);
003839 sqlite3VdbeAddOp3(v, op, r2, r1, target);
003840 testcase( regFree1==0 );
003841 testcase( regFree2==0 );
003842 break;
003843 }
003844 case TK_UMINUS: {
003845 Expr *pLeft = pExpr->pLeft;
003846 assert( pLeft );
003847 if( pLeft->op==TK_INTEGER ){
003848 codeInteger(pParse, pLeft, 1, target);
003849 return target;
003850 #ifndef SQLITE_OMIT_FLOATING_POINT
003851 }else if( pLeft->op==TK_FLOAT ){
003852 assert( !ExprHasProperty(pExpr, EP_IntValue) );
003853 codeReal(v, pLeft->u.zToken, 1, target);
003854 return target;
003855 #endif
003856 }else{
003857 tempX.op = TK_INTEGER;
003858 tempX.flags = EP_IntValue|EP_TokenOnly;
003859 tempX.u.iValue = 0;
003860 r1 = sqlite3ExprCodeTemp(pParse, &tempX, ®Free1);
003861 r2 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free2);
003862 sqlite3VdbeAddOp3(v, OP_Subtract, r2, r1, target);
003863 testcase( regFree2==0 );
003864 }
003865 break;
003866 }
003867 case TK_BITNOT:
003868 case TK_NOT: {
003869 assert( TK_BITNOT==OP_BitNot ); testcase( op==TK_BITNOT );
003870 assert( TK_NOT==OP_Not ); testcase( op==TK_NOT );
003871 r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free1);
003872 testcase( regFree1==0 );
003873 sqlite3VdbeAddOp2(v, op, r1, inReg);
003874 break;
003875 }
003876 case TK_TRUTH: {
003877 int isTrue; /* IS TRUE or IS NOT TRUE */
003878 int bNormal; /* IS TRUE or IS FALSE */
003879 r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free1);
003880 testcase( regFree1==0 );
003881 isTrue = sqlite3ExprTruthValue(pExpr->pRight);
003882 bNormal = pExpr->op2==TK_IS;
003883 testcase( isTrue && bNormal);
003884 testcase( !isTrue && bNormal);
003885 sqlite3VdbeAddOp4Int(v, OP_IsTrue, r1, inReg, !isTrue, isTrue ^ bNormal);
003886 break;
003887 }
003888 case TK_ISNULL:
003889 case TK_NOTNULL: {
003890 int addr;
003891 assert( TK_ISNULL==OP_IsNull ); testcase( op==TK_ISNULL );
003892 assert( TK_NOTNULL==OP_NotNull ); testcase( op==TK_NOTNULL );
003893 sqlite3VdbeAddOp2(v, OP_Integer, 1, target);
003894 r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free1);
003895 testcase( regFree1==0 );
003896 addr = sqlite3VdbeAddOp1(v, op, r1);
003897 VdbeCoverageIf(v, op==TK_ISNULL);
003898 VdbeCoverageIf(v, op==TK_NOTNULL);
003899 sqlite3VdbeAddOp2(v, OP_Integer, 0, target);
003900 sqlite3VdbeJumpHere(v, addr);
003901 break;
003902 }
003903 case TK_AGG_FUNCTION: {
003904 AggInfo *pInfo = pExpr->pAggInfo;
003905 if( pInfo==0 ){
003906 assert( !ExprHasProperty(pExpr, EP_IntValue) );
003907 sqlite3ErrorMsg(pParse, "misuse of aggregate: %s()", pExpr->u.zToken);
003908 }else{
003909 return pInfo->aFunc[pExpr->iAgg].iMem;
003910 }
003911 break;
003912 }
003913 case TK_FUNCTION: {
003914 ExprList *pFarg; /* List of function arguments */
003915 int nFarg; /* Number of function arguments */
003916 FuncDef *pDef; /* The function definition object */
003917 const char *zId; /* The function name */
003918 u32 constMask = 0; /* Mask of function arguments that are constant */
003919 int i; /* Loop counter */
003920 sqlite3 *db = pParse->db; /* The database connection */
003921 u8 enc = ENC(db); /* The text encoding used by this database */
003922 CollSeq *pColl = 0; /* A collating sequence */
003923
003924 #ifndef SQLITE_OMIT_WINDOWFUNC
003925 if( ExprHasProperty(pExpr, EP_WinFunc) ){
003926 return pExpr->y.pWin->regResult;
003927 }
003928 #endif
003929
003930 if( ConstFactorOk(pParse) && sqlite3ExprIsConstantNotJoin(pExpr) ){
003931 /* SQL functions can be expensive. So try to move constant functions
003932 ** out of the inner loop, even if that means an extra OP_Copy. */
003933 return sqlite3ExprCodeAtInit(pParse, pExpr, -1);
003934 }
003935 assert( !ExprHasProperty(pExpr, EP_xIsSelect) );
003936 if( ExprHasProperty(pExpr, EP_TokenOnly) ){
003937 pFarg = 0;
003938 }else{
003939 pFarg = pExpr->x.pList;
003940 }
003941 nFarg = pFarg ? pFarg->nExpr : 0;
003942 assert( !ExprHasProperty(pExpr, EP_IntValue) );
003943 zId = pExpr->u.zToken;
003944 pDef = sqlite3FindFunction(db, zId, nFarg, enc, 0);
003945 #ifdef SQLITE_ENABLE_UNKNOWN_SQL_FUNCTION
003946 if( pDef==0 && pParse->explain ){
003947 pDef = sqlite3FindFunction(db, "unknown", nFarg, enc, 0);
003948 }
003949 #endif
003950 if( pDef==0 || pDef->xFinalize!=0 ){
003951 sqlite3ErrorMsg(pParse, "unknown function: %s()", zId);
003952 break;
003953 }
003954
003955 /* Attempt a direct implementation of the built-in COALESCE() and
003956 ** IFNULL() functions. This avoids unnecessary evaluation of
003957 ** arguments past the first non-NULL argument.
003958 */
003959 if( pDef->funcFlags & SQLITE_FUNC_COALESCE ){
003960 int endCoalesce = sqlite3VdbeMakeLabel(pParse);
003961 assert( nFarg>=2 );
003962 sqlite3ExprCode(pParse, pFarg->a[0].pExpr, target);
003963 for(i=1; i<nFarg; i++){
003964 sqlite3VdbeAddOp2(v, OP_NotNull, target, endCoalesce);
003965 VdbeCoverage(v);
003966 sqlite3ExprCode(pParse, pFarg->a[i].pExpr, target);
003967 }
003968 sqlite3VdbeResolveLabel(v, endCoalesce);
003969 break;
003970 }
003971
003972 /* The UNLIKELY() function is a no-op. The result is the value
003973 ** of the first argument.
003974 */
003975 if( pDef->funcFlags & SQLITE_FUNC_UNLIKELY ){
003976 assert( nFarg>=1 );
003977 return sqlite3ExprCodeTarget(pParse, pFarg->a[0].pExpr, target);
003978 }
003979
003980 #ifdef SQLITE_DEBUG
003981 /* The AFFINITY() function evaluates to a string that describes
003982 ** the type affinity of the argument. This is used for testing of
003983 ** the SQLite type logic.
003984 */
003985 if( pDef->funcFlags & SQLITE_FUNC_AFFINITY ){
003986 const char *azAff[] = { "blob", "text", "numeric", "integer", "real" };
003987 char aff;
003988 assert( nFarg==1 );
003989 aff = sqlite3ExprAffinity(pFarg->a[0].pExpr);
003990 sqlite3VdbeLoadString(v, target,
003991 (aff<=SQLITE_AFF_NONE) ? "none" : azAff[aff-SQLITE_AFF_BLOB]);
003992 return target;
003993 }
003994 #endif
003995
003996 for(i=0; i<nFarg; i++){
003997 if( i<32 && sqlite3ExprIsConstant(pFarg->a[i].pExpr) ){
003998 testcase( i==31 );
003999 constMask |= MASKBIT32(i);
004000 }
004001 if( (pDef->funcFlags & SQLITE_FUNC_NEEDCOLL)!=0 && !pColl ){
004002 pColl = sqlite3ExprCollSeq(pParse, pFarg->a[i].pExpr);
004003 }
004004 }
004005 if( pFarg ){
004006 if( constMask ){
004007 r1 = pParse->nMem+1;
004008 pParse->nMem += nFarg;
004009 }else{
004010 r1 = sqlite3GetTempRange(pParse, nFarg);
004011 }
004012
004013 /* For length() and typeof() functions with a column argument,
004014 ** set the P5 parameter to the OP_Column opcode to OPFLAG_LENGTHARG
004015 ** or OPFLAG_TYPEOFARG respectively, to avoid unnecessary data
004016 ** loading.
004017 */
004018 if( (pDef->funcFlags & (SQLITE_FUNC_LENGTH|SQLITE_FUNC_TYPEOF))!=0 ){
004019 u8 exprOp;
004020 assert( nFarg==1 );
004021 assert( pFarg->a[0].pExpr!=0 );
004022 exprOp = pFarg->a[0].pExpr->op;
004023 if( exprOp==TK_COLUMN || exprOp==TK_AGG_COLUMN ){
004024 assert( SQLITE_FUNC_LENGTH==OPFLAG_LENGTHARG );
004025 assert( SQLITE_FUNC_TYPEOF==OPFLAG_TYPEOFARG );
004026 testcase( pDef->funcFlags & OPFLAG_LENGTHARG );
004027 pFarg->a[0].pExpr->op2 =
004028 pDef->funcFlags & (OPFLAG_LENGTHARG|OPFLAG_TYPEOFARG);
004029 }
004030 }
004031
004032 sqlite3ExprCodeExprList(pParse, pFarg, r1, 0,
004033 SQLITE_ECEL_DUP|SQLITE_ECEL_FACTOR);
004034 }else{
004035 r1 = 0;
004036 }
004037 #ifndef SQLITE_OMIT_VIRTUALTABLE
004038 /* Possibly overload the function if the first argument is
004039 ** a virtual table column.
004040 **
004041 ** For infix functions (LIKE, GLOB, REGEXP, and MATCH) use the
004042 ** second argument, not the first, as the argument to test to
004043 ** see if it is a column in a virtual table. This is done because
004044 ** the left operand of infix functions (the operand we want to
004045 ** control overloading) ends up as the second argument to the
004046 ** function. The expression "A glob B" is equivalent to
004047 ** "glob(B,A). We want to use the A in "A glob B" to test
004048 ** for function overloading. But we use the B term in "glob(B,A)".
004049 */
004050 if( nFarg>=2 && ExprHasProperty(pExpr, EP_InfixFunc) ){
004051 pDef = sqlite3VtabOverloadFunction(db, pDef, nFarg, pFarg->a[1].pExpr);
004052 }else if( nFarg>0 ){
004053 pDef = sqlite3VtabOverloadFunction(db, pDef, nFarg, pFarg->a[0].pExpr);
004054 }
004055 #endif
004056 if( pDef->funcFlags & SQLITE_FUNC_NEEDCOLL ){
004057 if( !pColl ) pColl = db->pDfltColl;
004058 sqlite3VdbeAddOp4(v, OP_CollSeq, 0, 0, 0, (char *)pColl, P4_COLLSEQ);
004059 }
004060 #ifdef SQLITE_ENABLE_OFFSET_SQL_FUNC
004061 if( pDef->funcFlags & SQLITE_FUNC_OFFSET ){
004062 Expr *pArg = pFarg->a[0].pExpr;
004063 if( pArg->op==TK_COLUMN ){
004064 sqlite3VdbeAddOp3(v, OP_Offset, pArg->iTable, pArg->iColumn, target);
004065 }else{
004066 sqlite3VdbeAddOp2(v, OP_Null, 0, target);
004067 }
004068 }else
004069 #endif
004070 {
004071 sqlite3VdbeAddFunctionCall(pParse, constMask, r1, target, nFarg,
004072 pDef, pExpr->op2);
004073 }
004074 if( nFarg ){
004075 if( constMask==0 ){
004076 sqlite3ReleaseTempRange(pParse, r1, nFarg);
004077 }else{
004078 sqlite3VdbeReleaseRegisters(pParse, r1, nFarg, constMask);
004079 }
004080 }
004081 return target;
004082 }
004083 #ifndef SQLITE_OMIT_SUBQUERY
004084 case TK_EXISTS:
004085 case TK_SELECT: {
004086 int nCol;
004087 testcase( op==TK_EXISTS );
004088 testcase( op==TK_SELECT );
004089 if( op==TK_SELECT && (nCol = pExpr->x.pSelect->pEList->nExpr)!=1 ){
004090 sqlite3SubselectError(pParse, nCol, 1);
004091 }else{
004092 return sqlite3CodeSubselect(pParse, pExpr);
004093 }
004094 break;
004095 }
004096 case TK_SELECT_COLUMN: {
004097 int n;
004098 if( pExpr->pLeft->iTable==0 ){
004099 pExpr->pLeft->iTable = sqlite3CodeSubselect(pParse, pExpr->pLeft);
004100 }
004101 assert( pExpr->iTable==0 || pExpr->pLeft->op==TK_SELECT );
004102 if( pExpr->iTable!=0
004103 && pExpr->iTable!=(n = sqlite3ExprVectorSize(pExpr->pLeft))
004104 ){
004105 sqlite3ErrorMsg(pParse, "%d columns assigned %d values",
004106 pExpr->iTable, n);
004107 }
004108 return pExpr->pLeft->iTable + pExpr->iColumn;
004109 }
004110 case TK_IN: {
004111 int destIfFalse = sqlite3VdbeMakeLabel(pParse);
004112 int destIfNull = sqlite3VdbeMakeLabel(pParse);
004113 sqlite3VdbeAddOp2(v, OP_Null, 0, target);
004114 sqlite3ExprCodeIN(pParse, pExpr, destIfFalse, destIfNull);
004115 sqlite3VdbeAddOp2(v, OP_Integer, 1, target);
004116 sqlite3VdbeResolveLabel(v, destIfFalse);
004117 sqlite3VdbeAddOp2(v, OP_AddImm, target, 0);
004118 sqlite3VdbeResolveLabel(v, destIfNull);
004119 return target;
004120 }
004121 #endif /* SQLITE_OMIT_SUBQUERY */
004122
004123
004124 /*
004125 ** x BETWEEN y AND z
004126 **
004127 ** This is equivalent to
004128 **
004129 ** x>=y AND x<=z
004130 **
004131 ** X is stored in pExpr->pLeft.
004132 ** Y is stored in pExpr->pList->a[0].pExpr.
004133 ** Z is stored in pExpr->pList->a[1].pExpr.
004134 */
004135 case TK_BETWEEN: {
004136 exprCodeBetween(pParse, pExpr, target, 0, 0);
004137 return target;
004138 }
004139 case TK_SPAN:
004140 case TK_COLLATE:
004141 case TK_UPLUS: {
004142 pExpr = pExpr->pLeft;
004143 goto expr_code_doover; /* 2018-04-28: Prevent deep recursion. OSSFuzz. */
004144 }
004145
004146 case TK_TRIGGER: {
004147 /* If the opcode is TK_TRIGGER, then the expression is a reference
004148 ** to a column in the new.* or old.* pseudo-tables available to
004149 ** trigger programs. In this case Expr.iTable is set to 1 for the
004150 ** new.* pseudo-table, or 0 for the old.* pseudo-table. Expr.iColumn
004151 ** is set to the column of the pseudo-table to read, or to -1 to
004152 ** read the rowid field.
004153 **
004154 ** The expression is implemented using an OP_Param opcode. The p1
004155 ** parameter is set to 0 for an old.rowid reference, or to (i+1)
004156 ** to reference another column of the old.* pseudo-table, where
004157 ** i is the index of the column. For a new.rowid reference, p1 is
004158 ** set to (n+1), where n is the number of columns in each pseudo-table.
004159 ** For a reference to any other column in the new.* pseudo-table, p1
004160 ** is set to (n+2+i), where n and i are as defined previously. For
004161 ** example, if the table on which triggers are being fired is
004162 ** declared as:
004163 **
004164 ** CREATE TABLE t1(a, b);
004165 **
004166 ** Then p1 is interpreted as follows:
004167 **
004168 ** p1==0 -> old.rowid p1==3 -> new.rowid
004169 ** p1==1 -> old.a p1==4 -> new.a
004170 ** p1==2 -> old.b p1==5 -> new.b
004171 */
004172 Table *pTab = pExpr->y.pTab;
004173 int iCol = pExpr->iColumn;
004174 int p1 = pExpr->iTable * (pTab->nCol+1) + 1
004175 + sqlite3TableColumnToStorage(pTab, iCol);
004176
004177 assert( pExpr->iTable==0 || pExpr->iTable==1 );
004178 assert( iCol>=-1 && iCol<pTab->nCol );
004179 assert( pTab->iPKey<0 || iCol!=pTab->iPKey );
004180 assert( p1>=0 && p1<(pTab->nCol*2+2) );
004181
004182 sqlite3VdbeAddOp2(v, OP_Param, p1, target);
004183 VdbeComment((v, "r[%d]=%s.%s", target,
004184 (pExpr->iTable ? "new" : "old"),
004185 (pExpr->iColumn<0 ? "rowid" : pExpr->y.pTab->aCol[iCol].zName)
004186 ));
004187
004188 #ifndef SQLITE_OMIT_FLOATING_POINT
004189 /* If the column has REAL affinity, it may currently be stored as an
004190 ** integer. Use OP_RealAffinity to make sure it is really real.
004191 **
004192 ** EVIDENCE-OF: R-60985-57662 SQLite will convert the value back to
004193 ** floating point when extracting it from the record. */
004194 if( iCol>=0 && pTab->aCol[iCol].affinity==SQLITE_AFF_REAL ){
004195 sqlite3VdbeAddOp1(v, OP_RealAffinity, target);
004196 }
004197 #endif
004198 break;
004199 }
004200
004201 case TK_VECTOR: {
004202 sqlite3ErrorMsg(pParse, "row value misused");
004203 break;
004204 }
004205
004206 /* TK_IF_NULL_ROW Expr nodes are inserted ahead of expressions
004207 ** that derive from the right-hand table of a LEFT JOIN. The
004208 ** Expr.iTable value is the table number for the right-hand table.
004209 ** The expression is only evaluated if that table is not currently
004210 ** on a LEFT JOIN NULL row.
004211 */
004212 case TK_IF_NULL_ROW: {
004213 int addrINR;
004214 u8 okConstFactor = pParse->okConstFactor;
004215 addrINR = sqlite3VdbeAddOp1(v, OP_IfNullRow, pExpr->iTable);
004216 /* Temporarily disable factoring of constant expressions, since
004217 ** even though expressions may appear to be constant, they are not
004218 ** really constant because they originate from the right-hand side
004219 ** of a LEFT JOIN. */
004220 pParse->okConstFactor = 0;
004221 inReg = sqlite3ExprCodeTarget(pParse, pExpr->pLeft, target);
004222 pParse->okConstFactor = okConstFactor;
004223 sqlite3VdbeJumpHere(v, addrINR);
004224 sqlite3VdbeChangeP3(v, addrINR, inReg);
004225 break;
004226 }
004227
004228 /*
004229 ** Form A:
004230 ** CASE x WHEN e1 THEN r1 WHEN e2 THEN r2 ... WHEN eN THEN rN ELSE y END
004231 **
004232 ** Form B:
004233 ** CASE WHEN e1 THEN r1 WHEN e2 THEN r2 ... WHEN eN THEN rN ELSE y END
004234 **
004235 ** Form A is can be transformed into the equivalent form B as follows:
004236 ** CASE WHEN x=e1 THEN r1 WHEN x=e2 THEN r2 ...
004237 ** WHEN x=eN THEN rN ELSE y END
004238 **
004239 ** X (if it exists) is in pExpr->pLeft.
004240 ** Y is in the last element of pExpr->x.pList if pExpr->x.pList->nExpr is
004241 ** odd. The Y is also optional. If the number of elements in x.pList
004242 ** is even, then Y is omitted and the "otherwise" result is NULL.
004243 ** Ei is in pExpr->pList->a[i*2] and Ri is pExpr->pList->a[i*2+1].
004244 **
004245 ** The result of the expression is the Ri for the first matching Ei,
004246 ** or if there is no matching Ei, the ELSE term Y, or if there is
004247 ** no ELSE term, NULL.
004248 */
004249 case TK_CASE: {
004250 int endLabel; /* GOTO label for end of CASE stmt */
004251 int nextCase; /* GOTO label for next WHEN clause */
004252 int nExpr; /* 2x number of WHEN terms */
004253 int i; /* Loop counter */
004254 ExprList *pEList; /* List of WHEN terms */
004255 struct ExprList_item *aListelem; /* Array of WHEN terms */
004256 Expr opCompare; /* The X==Ei expression */
004257 Expr *pX; /* The X expression */
004258 Expr *pTest = 0; /* X==Ei (form A) or just Ei (form B) */
004259 Expr *pDel = 0;
004260 sqlite3 *db = pParse->db;
004261
004262 assert( !ExprHasProperty(pExpr, EP_xIsSelect) && pExpr->x.pList );
004263 assert(pExpr->x.pList->nExpr > 0);
004264 pEList = pExpr->x.pList;
004265 aListelem = pEList->a;
004266 nExpr = pEList->nExpr;
004267 endLabel = sqlite3VdbeMakeLabel(pParse);
004268 if( (pX = pExpr->pLeft)!=0 ){
004269 pDel = sqlite3ExprDup(db, pX, 0);
004270 if( db->mallocFailed ){
004271 sqlite3ExprDelete(db, pDel);
004272 break;
004273 }
004274 testcase( pX->op==TK_COLUMN );
004275 exprToRegister(pDel, exprCodeVector(pParse, pDel, ®Free1));
004276 testcase( regFree1==0 );
004277 memset(&opCompare, 0, sizeof(opCompare));
004278 opCompare.op = TK_EQ;
004279 opCompare.pLeft = pDel;
004280 pTest = &opCompare;
004281 /* Ticket b351d95f9cd5ef17e9d9dbae18f5ca8611190001:
004282 ** The value in regFree1 might get SCopy-ed into the file result.
004283 ** So make sure that the regFree1 register is not reused for other
004284 ** purposes and possibly overwritten. */
004285 regFree1 = 0;
004286 }
004287 for(i=0; i<nExpr-1; i=i+2){
004288 if( pX ){
004289 assert( pTest!=0 );
004290 opCompare.pRight = aListelem[i].pExpr;
004291 }else{
004292 pTest = aListelem[i].pExpr;
004293 }
004294 nextCase = sqlite3VdbeMakeLabel(pParse);
004295 testcase( pTest->op==TK_COLUMN );
004296 sqlite3ExprIfFalse(pParse, pTest, nextCase, SQLITE_JUMPIFNULL);
004297 testcase( aListelem[i+1].pExpr->op==TK_COLUMN );
004298 sqlite3ExprCode(pParse, aListelem[i+1].pExpr, target);
004299 sqlite3VdbeGoto(v, endLabel);
004300 sqlite3VdbeResolveLabel(v, nextCase);
004301 }
004302 if( (nExpr&1)!=0 ){
004303 sqlite3ExprCode(pParse, pEList->a[nExpr-1].pExpr, target);
004304 }else{
004305 sqlite3VdbeAddOp2(v, OP_Null, 0, target);
004306 }
004307 sqlite3ExprDelete(db, pDel);
004308 sqlite3VdbeResolveLabel(v, endLabel);
004309 break;
004310 }
004311 #ifndef SQLITE_OMIT_TRIGGER
004312 case TK_RAISE: {
004313 assert( pExpr->affExpr==OE_Rollback
004314 || pExpr->affExpr==OE_Abort
004315 || pExpr->affExpr==OE_Fail
004316 || pExpr->affExpr==OE_Ignore
004317 );
004318 if( !pParse->pTriggerTab ){
004319 sqlite3ErrorMsg(pParse,
004320 "RAISE() may only be used within a trigger-program");
004321 return 0;
004322 }
004323 if( pExpr->affExpr==OE_Abort ){
004324 sqlite3MayAbort(pParse);
004325 }
004326 assert( !ExprHasProperty(pExpr, EP_IntValue) );
004327 if( pExpr->affExpr==OE_Ignore ){
004328 sqlite3VdbeAddOp4(
004329 v, OP_Halt, SQLITE_OK, OE_Ignore, 0, pExpr->u.zToken,0);
004330 VdbeCoverage(v);
004331 }else{
004332 sqlite3HaltConstraint(pParse, SQLITE_CONSTRAINT_TRIGGER,
004333 pExpr->affExpr, pExpr->u.zToken, 0, 0);
004334 }
004335
004336 break;
004337 }
004338 #endif
004339 }
004340 sqlite3ReleaseTempReg(pParse, regFree1);
004341 sqlite3ReleaseTempReg(pParse, regFree2);
004342 return inReg;
004343 }
004344
004345 /*
004346 ** Factor out the code of the given expression to initialization time.
004347 **
004348 ** If regDest>=0 then the result is always stored in that register and the
004349 ** result is not reusable. If regDest<0 then this routine is free to
004350 ** store the value whereever it wants. The register where the expression
004351 ** is stored is returned. When regDest<0, two identical expressions will
004352 ** code to the same register.
004353 */
004354 int sqlite3ExprCodeAtInit(
004355 Parse *pParse, /* Parsing context */
004356 Expr *pExpr, /* The expression to code when the VDBE initializes */
004357 int regDest /* Store the value in this register */
004358 ){
004359 ExprList *p;
004360 assert( ConstFactorOk(pParse) );
004361 p = pParse->pConstExpr;
004362 if( regDest<0 && p ){
004363 struct ExprList_item *pItem;
004364 int i;
004365 for(pItem=p->a, i=p->nExpr; i>0; pItem++, i--){
004366 if( pItem->reusable && sqlite3ExprCompare(0,pItem->pExpr,pExpr,-1)==0 ){
004367 return pItem->u.iConstExprReg;
004368 }
004369 }
004370 }
004371 pExpr = sqlite3ExprDup(pParse->db, pExpr, 0);
004372 p = sqlite3ExprListAppend(pParse, p, pExpr);
004373 if( p ){
004374 struct ExprList_item *pItem = &p->a[p->nExpr-1];
004375 pItem->reusable = regDest<0;
004376 if( regDest<0 ) regDest = ++pParse->nMem;
004377 pItem->u.iConstExprReg = regDest;
004378 }
004379 pParse->pConstExpr = p;
004380 return regDest;
004381 }
004382
004383 /*
004384 ** Generate code to evaluate an expression and store the results
004385 ** into a register. Return the register number where the results
004386 ** are stored.
004387 **
004388 ** If the register is a temporary register that can be deallocated,
004389 ** then write its number into *pReg. If the result register is not
004390 ** a temporary, then set *pReg to zero.
004391 **
004392 ** If pExpr is a constant, then this routine might generate this
004393 ** code to fill the register in the initialization section of the
004394 ** VDBE program, in order to factor it out of the evaluation loop.
004395 */
004396 int sqlite3ExprCodeTemp(Parse *pParse, Expr *pExpr, int *pReg){
004397 int r2;
004398 pExpr = sqlite3ExprSkipCollateAndLikely(pExpr);
004399 if( ConstFactorOk(pParse)
004400 && pExpr->op!=TK_REGISTER
004401 && sqlite3ExprIsConstantNotJoin(pExpr)
004402 ){
004403 *pReg = 0;
004404 r2 = sqlite3ExprCodeAtInit(pParse, pExpr, -1);
004405 }else{
004406 int r1 = sqlite3GetTempReg(pParse);
004407 r2 = sqlite3ExprCodeTarget(pParse, pExpr, r1);
004408 if( r2==r1 ){
004409 *pReg = r1;
004410 }else{
004411 sqlite3ReleaseTempReg(pParse, r1);
004412 *pReg = 0;
004413 }
004414 }
004415 return r2;
004416 }
004417
004418 /*
004419 ** Generate code that will evaluate expression pExpr and store the
004420 ** results in register target. The results are guaranteed to appear
004421 ** in register target.
004422 */
004423 void sqlite3ExprCode(Parse *pParse, Expr *pExpr, int target){
004424 int inReg;
004425
004426 assert( target>0 && target<=pParse->nMem );
004427 inReg = sqlite3ExprCodeTarget(pParse, pExpr, target);
004428 assert( pParse->pVdbe!=0 || pParse->db->mallocFailed );
004429 if( inReg!=target && pParse->pVdbe ){
004430 sqlite3VdbeAddOp2(pParse->pVdbe, OP_SCopy, inReg, target);
004431 }
004432 }
004433
004434 /*
004435 ** Make a transient copy of expression pExpr and then code it using
004436 ** sqlite3ExprCode(). This routine works just like sqlite3ExprCode()
004437 ** except that the input expression is guaranteed to be unchanged.
004438 */
004439 void sqlite3ExprCodeCopy(Parse *pParse, Expr *pExpr, int target){
004440 sqlite3 *db = pParse->db;
004441 pExpr = sqlite3ExprDup(db, pExpr, 0);
004442 if( !db->mallocFailed ) sqlite3ExprCode(pParse, pExpr, target);
004443 sqlite3ExprDelete(db, pExpr);
004444 }
004445
004446 /*
004447 ** Generate code that will evaluate expression pExpr and store the
004448 ** results in register target. The results are guaranteed to appear
004449 ** in register target. If the expression is constant, then this routine
004450 ** might choose to code the expression at initialization time.
004451 */
004452 void sqlite3ExprCodeFactorable(Parse *pParse, Expr *pExpr, int target){
004453 if( pParse->okConstFactor && sqlite3ExprIsConstantNotJoin(pExpr) ){
004454 sqlite3ExprCodeAtInit(pParse, pExpr, target);
004455 }else{
004456 sqlite3ExprCode(pParse, pExpr, target);
004457 }
004458 }
004459
004460 /*
004461 ** Generate code that pushes the value of every element of the given
004462 ** expression list into a sequence of registers beginning at target.
004463 **
004464 ** Return the number of elements evaluated. The number returned will
004465 ** usually be pList->nExpr but might be reduced if SQLITE_ECEL_OMITREF
004466 ** is defined.
004467 **
004468 ** The SQLITE_ECEL_DUP flag prevents the arguments from being
004469 ** filled using OP_SCopy. OP_Copy must be used instead.
004470 **
004471 ** The SQLITE_ECEL_FACTOR argument allows constant arguments to be
004472 ** factored out into initialization code.
004473 **
004474 ** The SQLITE_ECEL_REF flag means that expressions in the list with
004475 ** ExprList.a[].u.x.iOrderByCol>0 have already been evaluated and stored
004476 ** in registers at srcReg, and so the value can be copied from there.
004477 ** If SQLITE_ECEL_OMITREF is also set, then the values with u.x.iOrderByCol>0
004478 ** are simply omitted rather than being copied from srcReg.
004479 */
004480 int sqlite3ExprCodeExprList(
004481 Parse *pParse, /* Parsing context */
004482 ExprList *pList, /* The expression list to be coded */
004483 int target, /* Where to write results */
004484 int srcReg, /* Source registers if SQLITE_ECEL_REF */
004485 u8 flags /* SQLITE_ECEL_* flags */
004486 ){
004487 struct ExprList_item *pItem;
004488 int i, j, n;
004489 u8 copyOp = (flags & SQLITE_ECEL_DUP) ? OP_Copy : OP_SCopy;
004490 Vdbe *v = pParse->pVdbe;
004491 assert( pList!=0 );
004492 assert( target>0 );
004493 assert( pParse->pVdbe!=0 ); /* Never gets this far otherwise */
004494 n = pList->nExpr;
004495 if( !ConstFactorOk(pParse) ) flags &= ~SQLITE_ECEL_FACTOR;
004496 for(pItem=pList->a, i=0; i<n; i++, pItem++){
004497 Expr *pExpr = pItem->pExpr;
004498 #ifdef SQLITE_ENABLE_SORTER_REFERENCES
004499 if( pItem->bSorterRef ){
004500 i--;
004501 n--;
004502 }else
004503 #endif
004504 if( (flags & SQLITE_ECEL_REF)!=0 && (j = pItem->u.x.iOrderByCol)>0 ){
004505 if( flags & SQLITE_ECEL_OMITREF ){
004506 i--;
004507 n--;
004508 }else{
004509 sqlite3VdbeAddOp2(v, copyOp, j+srcReg-1, target+i);
004510 }
004511 }else if( (flags & SQLITE_ECEL_FACTOR)!=0
004512 && sqlite3ExprIsConstantNotJoin(pExpr)
004513 ){
004514 sqlite3ExprCodeAtInit(pParse, pExpr, target+i);
004515 }else{
004516 int inReg = sqlite3ExprCodeTarget(pParse, pExpr, target+i);
004517 if( inReg!=target+i ){
004518 VdbeOp *pOp;
004519 if( copyOp==OP_Copy
004520 && (pOp=sqlite3VdbeGetOp(v, -1))->opcode==OP_Copy
004521 && pOp->p1+pOp->p3+1==inReg
004522 && pOp->p2+pOp->p3+1==target+i
004523 ){
004524 pOp->p3++;
004525 }else{
004526 sqlite3VdbeAddOp2(v, copyOp, inReg, target+i);
004527 }
004528 }
004529 }
004530 }
004531 return n;
004532 }
004533
004534 /*
004535 ** Generate code for a BETWEEN operator.
004536 **
004537 ** x BETWEEN y AND z
004538 **
004539 ** The above is equivalent to
004540 **
004541 ** x>=y AND x<=z
004542 **
004543 ** Code it as such, taking care to do the common subexpression
004544 ** elimination of x.
004545 **
004546 ** The xJumpIf parameter determines details:
004547 **
004548 ** NULL: Store the boolean result in reg[dest]
004549 ** sqlite3ExprIfTrue: Jump to dest if true
004550 ** sqlite3ExprIfFalse: Jump to dest if false
004551 **
004552 ** The jumpIfNull parameter is ignored if xJumpIf is NULL.
004553 */
004554 static void exprCodeBetween(
004555 Parse *pParse, /* Parsing and code generating context */
004556 Expr *pExpr, /* The BETWEEN expression */
004557 int dest, /* Jump destination or storage location */
004558 void (*xJump)(Parse*,Expr*,int,int), /* Action to take */
004559 int jumpIfNull /* Take the jump if the BETWEEN is NULL */
004560 ){
004561 Expr exprAnd; /* The AND operator in x>=y AND x<=z */
004562 Expr compLeft; /* The x>=y term */
004563 Expr compRight; /* The x<=z term */
004564 int regFree1 = 0; /* Temporary use register */
004565 Expr *pDel = 0;
004566 sqlite3 *db = pParse->db;
004567
004568 memset(&compLeft, 0, sizeof(Expr));
004569 memset(&compRight, 0, sizeof(Expr));
004570 memset(&exprAnd, 0, sizeof(Expr));
004571
004572 assert( !ExprHasProperty(pExpr, EP_xIsSelect) );
004573 pDel = sqlite3ExprDup(db, pExpr->pLeft, 0);
004574 if( db->mallocFailed==0 ){
004575 exprAnd.op = TK_AND;
004576 exprAnd.pLeft = &compLeft;
004577 exprAnd.pRight = &compRight;
004578 compLeft.op = TK_GE;
004579 compLeft.pLeft = pDel;
004580 compLeft.pRight = pExpr->x.pList->a[0].pExpr;
004581 compRight.op = TK_LE;
004582 compRight.pLeft = pDel;
004583 compRight.pRight = pExpr->x.pList->a[1].pExpr;
004584 exprToRegister(pDel, exprCodeVector(pParse, pDel, ®Free1));
004585 if( xJump ){
004586 xJump(pParse, &exprAnd, dest, jumpIfNull);
004587 }else{
004588 /* Mark the expression is being from the ON or USING clause of a join
004589 ** so that the sqlite3ExprCodeTarget() routine will not attempt to move
004590 ** it into the Parse.pConstExpr list. We should use a new bit for this,
004591 ** for clarity, but we are out of bits in the Expr.flags field so we
004592 ** have to reuse the EP_FromJoin bit. Bummer. */
004593 pDel->flags |= EP_FromJoin;
004594 sqlite3ExprCodeTarget(pParse, &exprAnd, dest);
004595 }
004596 sqlite3ReleaseTempReg(pParse, regFree1);
004597 }
004598 sqlite3ExprDelete(db, pDel);
004599
004600 /* Ensure adequate test coverage */
004601 testcase( xJump==sqlite3ExprIfTrue && jumpIfNull==0 && regFree1==0 );
004602 testcase( xJump==sqlite3ExprIfTrue && jumpIfNull==0 && regFree1!=0 );
004603 testcase( xJump==sqlite3ExprIfTrue && jumpIfNull!=0 && regFree1==0 );
004604 testcase( xJump==sqlite3ExprIfTrue && jumpIfNull!=0 && regFree1!=0 );
004605 testcase( xJump==sqlite3ExprIfFalse && jumpIfNull==0 && regFree1==0 );
004606 testcase( xJump==sqlite3ExprIfFalse && jumpIfNull==0 && regFree1!=0 );
004607 testcase( xJump==sqlite3ExprIfFalse && jumpIfNull!=0 && regFree1==0 );
004608 testcase( xJump==sqlite3ExprIfFalse && jumpIfNull!=0 && regFree1!=0 );
004609 testcase( xJump==0 );
004610 }
004611
004612 /*
004613 ** Generate code for a boolean expression such that a jump is made
004614 ** to the label "dest" if the expression is true but execution
004615 ** continues straight thru if the expression is false.
004616 **
004617 ** If the expression evaluates to NULL (neither true nor false), then
004618 ** take the jump if the jumpIfNull flag is SQLITE_JUMPIFNULL.
004619 **
004620 ** This code depends on the fact that certain token values (ex: TK_EQ)
004621 ** are the same as opcode values (ex: OP_Eq) that implement the corresponding
004622 ** operation. Special comments in vdbe.c and the mkopcodeh.awk script in
004623 ** the make process cause these values to align. Assert()s in the code
004624 ** below verify that the numbers are aligned correctly.
004625 */
004626 void sqlite3ExprIfTrue(Parse *pParse, Expr *pExpr, int dest, int jumpIfNull){
004627 Vdbe *v = pParse->pVdbe;
004628 int op = 0;
004629 int regFree1 = 0;
004630 int regFree2 = 0;
004631 int r1, r2;
004632
004633 assert( jumpIfNull==SQLITE_JUMPIFNULL || jumpIfNull==0 );
004634 if( NEVER(v==0) ) return; /* Existence of VDBE checked by caller */
004635 if( NEVER(pExpr==0) ) return; /* No way this can happen */
004636 op = pExpr->op;
004637 switch( op ){
004638 case TK_AND:
004639 case TK_OR: {
004640 Expr *pAlt = sqlite3ExprSimplifiedAndOr(pExpr);
004641 if( pAlt!=pExpr ){
004642 sqlite3ExprIfTrue(pParse, pAlt, dest, jumpIfNull);
004643 }else if( op==TK_AND ){
004644 int d2 = sqlite3VdbeMakeLabel(pParse);
004645 testcase( jumpIfNull==0 );
004646 sqlite3ExprIfFalse(pParse, pExpr->pLeft, d2,
004647 jumpIfNull^SQLITE_JUMPIFNULL);
004648 sqlite3ExprIfTrue(pParse, pExpr->pRight, dest, jumpIfNull);
004649 sqlite3VdbeResolveLabel(v, d2);
004650 }else{
004651 testcase( jumpIfNull==0 );
004652 sqlite3ExprIfTrue(pParse, pExpr->pLeft, dest, jumpIfNull);
004653 sqlite3ExprIfTrue(pParse, pExpr->pRight, dest, jumpIfNull);
004654 }
004655 break;
004656 }
004657 case TK_NOT: {
004658 testcase( jumpIfNull==0 );
004659 sqlite3ExprIfFalse(pParse, pExpr->pLeft, dest, jumpIfNull);
004660 break;
004661 }
004662 case TK_TRUTH: {
004663 int isNot; /* IS NOT TRUE or IS NOT FALSE */
004664 int isTrue; /* IS TRUE or IS NOT TRUE */
004665 testcase( jumpIfNull==0 );
004666 isNot = pExpr->op2==TK_ISNOT;
004667 isTrue = sqlite3ExprTruthValue(pExpr->pRight);
004668 testcase( isTrue && isNot );
004669 testcase( !isTrue && isNot );
004670 if( isTrue ^ isNot ){
004671 sqlite3ExprIfTrue(pParse, pExpr->pLeft, dest,
004672 isNot ? SQLITE_JUMPIFNULL : 0);
004673 }else{
004674 sqlite3ExprIfFalse(pParse, pExpr->pLeft, dest,
004675 isNot ? SQLITE_JUMPIFNULL : 0);
004676 }
004677 break;
004678 }
004679 case TK_IS:
004680 case TK_ISNOT:
004681 testcase( op==TK_IS );
004682 testcase( op==TK_ISNOT );
004683 op = (op==TK_IS) ? TK_EQ : TK_NE;
004684 jumpIfNull = SQLITE_NULLEQ;
004685 /* Fall thru */
004686 case TK_LT:
004687 case TK_LE:
004688 case TK_GT:
004689 case TK_GE:
004690 case TK_NE:
004691 case TK_EQ: {
004692 if( sqlite3ExprIsVector(pExpr->pLeft) ) goto default_expr;
004693 testcase( jumpIfNull==0 );
004694 r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free1);
004695 r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, ®Free2);
004696 codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op,
004697 r1, r2, dest, jumpIfNull, ExprHasProperty(pExpr,EP_Commuted));
004698 assert(TK_LT==OP_Lt); testcase(op==OP_Lt); VdbeCoverageIf(v,op==OP_Lt);
004699 assert(TK_LE==OP_Le); testcase(op==OP_Le); VdbeCoverageIf(v,op==OP_Le);
004700 assert(TK_GT==OP_Gt); testcase(op==OP_Gt); VdbeCoverageIf(v,op==OP_Gt);
004701 assert(TK_GE==OP_Ge); testcase(op==OP_Ge); VdbeCoverageIf(v,op==OP_Ge);
004702 assert(TK_EQ==OP_Eq); testcase(op==OP_Eq);
004703 VdbeCoverageIf(v, op==OP_Eq && jumpIfNull==SQLITE_NULLEQ);
004704 VdbeCoverageIf(v, op==OP_Eq && jumpIfNull!=SQLITE_NULLEQ);
004705 assert(TK_NE==OP_Ne); testcase(op==OP_Ne);
004706 VdbeCoverageIf(v, op==OP_Ne && jumpIfNull==SQLITE_NULLEQ);
004707 VdbeCoverageIf(v, op==OP_Ne && jumpIfNull!=SQLITE_NULLEQ);
004708 testcase( regFree1==0 );
004709 testcase( regFree2==0 );
004710 break;
004711 }
004712 case TK_ISNULL:
004713 case TK_NOTNULL: {
004714 assert( TK_ISNULL==OP_IsNull ); testcase( op==TK_ISNULL );
004715 assert( TK_NOTNULL==OP_NotNull ); testcase( op==TK_NOTNULL );
004716 r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free1);
004717 sqlite3VdbeAddOp2(v, op, r1, dest);
004718 VdbeCoverageIf(v, op==TK_ISNULL);
004719 VdbeCoverageIf(v, op==TK_NOTNULL);
004720 testcase( regFree1==0 );
004721 break;
004722 }
004723 case TK_BETWEEN: {
004724 testcase( jumpIfNull==0 );
004725 exprCodeBetween(pParse, pExpr, dest, sqlite3ExprIfTrue, jumpIfNull);
004726 break;
004727 }
004728 #ifndef SQLITE_OMIT_SUBQUERY
004729 case TK_IN: {
004730 int destIfFalse = sqlite3VdbeMakeLabel(pParse);
004731 int destIfNull = jumpIfNull ? dest : destIfFalse;
004732 sqlite3ExprCodeIN(pParse, pExpr, destIfFalse, destIfNull);
004733 sqlite3VdbeGoto(v, dest);
004734 sqlite3VdbeResolveLabel(v, destIfFalse);
004735 break;
004736 }
004737 #endif
004738 default: {
004739 default_expr:
004740 if( ExprAlwaysTrue(pExpr) ){
004741 sqlite3VdbeGoto(v, dest);
004742 }else if( ExprAlwaysFalse(pExpr) ){
004743 /* No-op */
004744 }else{
004745 r1 = sqlite3ExprCodeTemp(pParse, pExpr, ®Free1);
004746 sqlite3VdbeAddOp3(v, OP_If, r1, dest, jumpIfNull!=0);
004747 VdbeCoverage(v);
004748 testcase( regFree1==0 );
004749 testcase( jumpIfNull==0 );
004750 }
004751 break;
004752 }
004753 }
004754 sqlite3ReleaseTempReg(pParse, regFree1);
004755 sqlite3ReleaseTempReg(pParse, regFree2);
004756 }
004757
004758 /*
004759 ** Generate code for a boolean expression such that a jump is made
004760 ** to the label "dest" if the expression is false but execution
004761 ** continues straight thru if the expression is true.
004762 **
004763 ** If the expression evaluates to NULL (neither true nor false) then
004764 ** jump if jumpIfNull is SQLITE_JUMPIFNULL or fall through if jumpIfNull
004765 ** is 0.
004766 */
004767 void sqlite3ExprIfFalse(Parse *pParse, Expr *pExpr, int dest, int jumpIfNull){
004768 Vdbe *v = pParse->pVdbe;
004769 int op = 0;
004770 int regFree1 = 0;
004771 int regFree2 = 0;
004772 int r1, r2;
004773
004774 assert( jumpIfNull==SQLITE_JUMPIFNULL || jumpIfNull==0 );
004775 if( NEVER(v==0) ) return; /* Existence of VDBE checked by caller */
004776 if( pExpr==0 ) return;
004777
004778 /* The value of pExpr->op and op are related as follows:
004779 **
004780 ** pExpr->op op
004781 ** --------- ----------
004782 ** TK_ISNULL OP_NotNull
004783 ** TK_NOTNULL OP_IsNull
004784 ** TK_NE OP_Eq
004785 ** TK_EQ OP_Ne
004786 ** TK_GT OP_Le
004787 ** TK_LE OP_Gt
004788 ** TK_GE OP_Lt
004789 ** TK_LT OP_Ge
004790 **
004791 ** For other values of pExpr->op, op is undefined and unused.
004792 ** The value of TK_ and OP_ constants are arranged such that we
004793 ** can compute the mapping above using the following expression.
004794 ** Assert()s verify that the computation is correct.
004795 */
004796 op = ((pExpr->op+(TK_ISNULL&1))^1)-(TK_ISNULL&1);
004797
004798 /* Verify correct alignment of TK_ and OP_ constants
004799 */
004800 assert( pExpr->op!=TK_ISNULL || op==OP_NotNull );
004801 assert( pExpr->op!=TK_NOTNULL || op==OP_IsNull );
004802 assert( pExpr->op!=TK_NE || op==OP_Eq );
004803 assert( pExpr->op!=TK_EQ || op==OP_Ne );
004804 assert( pExpr->op!=TK_LT || op==OP_Ge );
004805 assert( pExpr->op!=TK_LE || op==OP_Gt );
004806 assert( pExpr->op!=TK_GT || op==OP_Le );
004807 assert( pExpr->op!=TK_GE || op==OP_Lt );
004808
004809 switch( pExpr->op ){
004810 case TK_AND:
004811 case TK_OR: {
004812 Expr *pAlt = sqlite3ExprSimplifiedAndOr(pExpr);
004813 if( pAlt!=pExpr ){
004814 sqlite3ExprIfFalse(pParse, pAlt, dest, jumpIfNull);
004815 }else if( pExpr->op==TK_AND ){
004816 testcase( jumpIfNull==0 );
004817 sqlite3ExprIfFalse(pParse, pExpr->pLeft, dest, jumpIfNull);
004818 sqlite3ExprIfFalse(pParse, pExpr->pRight, dest, jumpIfNull);
004819 }else{
004820 int d2 = sqlite3VdbeMakeLabel(pParse);
004821 testcase( jumpIfNull==0 );
004822 sqlite3ExprIfTrue(pParse, pExpr->pLeft, d2,
004823 jumpIfNull^SQLITE_JUMPIFNULL);
004824 sqlite3ExprIfFalse(pParse, pExpr->pRight, dest, jumpIfNull);
004825 sqlite3VdbeResolveLabel(v, d2);
004826 }
004827 break;
004828 }
004829 case TK_NOT: {
004830 testcase( jumpIfNull==0 );
004831 sqlite3ExprIfTrue(pParse, pExpr->pLeft, dest, jumpIfNull);
004832 break;
004833 }
004834 case TK_TRUTH: {
004835 int isNot; /* IS NOT TRUE or IS NOT FALSE */
004836 int isTrue; /* IS TRUE or IS NOT TRUE */
004837 testcase( jumpIfNull==0 );
004838 isNot = pExpr->op2==TK_ISNOT;
004839 isTrue = sqlite3ExprTruthValue(pExpr->pRight);
004840 testcase( isTrue && isNot );
004841 testcase( !isTrue && isNot );
004842 if( isTrue ^ isNot ){
004843 /* IS TRUE and IS NOT FALSE */
004844 sqlite3ExprIfFalse(pParse, pExpr->pLeft, dest,
004845 isNot ? 0 : SQLITE_JUMPIFNULL);
004846
004847 }else{
004848 /* IS FALSE and IS NOT TRUE */
004849 sqlite3ExprIfTrue(pParse, pExpr->pLeft, dest,
004850 isNot ? 0 : SQLITE_JUMPIFNULL);
004851 }
004852 break;
004853 }
004854 case TK_IS:
004855 case TK_ISNOT:
004856 testcase( pExpr->op==TK_IS );
004857 testcase( pExpr->op==TK_ISNOT );
004858 op = (pExpr->op==TK_IS) ? TK_NE : TK_EQ;
004859 jumpIfNull = SQLITE_NULLEQ;
004860 /* Fall thru */
004861 case TK_LT:
004862 case TK_LE:
004863 case TK_GT:
004864 case TK_GE:
004865 case TK_NE:
004866 case TK_EQ: {
004867 if( sqlite3ExprIsVector(pExpr->pLeft) ) goto default_expr;
004868 testcase( jumpIfNull==0 );
004869 r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free1);
004870 r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, ®Free2);
004871 codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op,
004872 r1, r2, dest, jumpIfNull,ExprHasProperty(pExpr,EP_Commuted));
004873 assert(TK_LT==OP_Lt); testcase(op==OP_Lt); VdbeCoverageIf(v,op==OP_Lt);
004874 assert(TK_LE==OP_Le); testcase(op==OP_Le); VdbeCoverageIf(v,op==OP_Le);
004875 assert(TK_GT==OP_Gt); testcase(op==OP_Gt); VdbeCoverageIf(v,op==OP_Gt);
004876 assert(TK_GE==OP_Ge); testcase(op==OP_Ge); VdbeCoverageIf(v,op==OP_Ge);
004877 assert(TK_EQ==OP_Eq); testcase(op==OP_Eq);
004878 VdbeCoverageIf(v, op==OP_Eq && jumpIfNull!=SQLITE_NULLEQ);
004879 VdbeCoverageIf(v, op==OP_Eq && jumpIfNull==SQLITE_NULLEQ);
004880 assert(TK_NE==OP_Ne); testcase(op==OP_Ne);
004881 VdbeCoverageIf(v, op==OP_Ne && jumpIfNull!=SQLITE_NULLEQ);
004882 VdbeCoverageIf(v, op==OP_Ne && jumpIfNull==SQLITE_NULLEQ);
004883 testcase( regFree1==0 );
004884 testcase( regFree2==0 );
004885 break;
004886 }
004887 case TK_ISNULL:
004888 case TK_NOTNULL: {
004889 r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free1);
004890 sqlite3VdbeAddOp2(v, op, r1, dest);
004891 testcase( op==TK_ISNULL ); VdbeCoverageIf(v, op==TK_ISNULL);
004892 testcase( op==TK_NOTNULL ); VdbeCoverageIf(v, op==TK_NOTNULL);
004893 testcase( regFree1==0 );
004894 break;
004895 }
004896 case TK_BETWEEN: {
004897 testcase( jumpIfNull==0 );
004898 exprCodeBetween(pParse, pExpr, dest, sqlite3ExprIfFalse, jumpIfNull);
004899 break;
004900 }
004901 #ifndef SQLITE_OMIT_SUBQUERY
004902 case TK_IN: {
004903 if( jumpIfNull ){
004904 sqlite3ExprCodeIN(pParse, pExpr, dest, dest);
004905 }else{
004906 int destIfNull = sqlite3VdbeMakeLabel(pParse);
004907 sqlite3ExprCodeIN(pParse, pExpr, dest, destIfNull);
004908 sqlite3VdbeResolveLabel(v, destIfNull);
004909 }
004910 break;
004911 }
004912 #endif
004913 default: {
004914 default_expr:
004915 if( ExprAlwaysFalse(pExpr) ){
004916 sqlite3VdbeGoto(v, dest);
004917 }else if( ExprAlwaysTrue(pExpr) ){
004918 /* no-op */
004919 }else{
004920 r1 = sqlite3ExprCodeTemp(pParse, pExpr, ®Free1);
004921 sqlite3VdbeAddOp3(v, OP_IfNot, r1, dest, jumpIfNull!=0);
004922 VdbeCoverage(v);
004923 testcase( regFree1==0 );
004924 testcase( jumpIfNull==0 );
004925 }
004926 break;
004927 }
004928 }
004929 sqlite3ReleaseTempReg(pParse, regFree1);
004930 sqlite3ReleaseTempReg(pParse, regFree2);
004931 }
004932
004933 /*
004934 ** Like sqlite3ExprIfFalse() except that a copy is made of pExpr before
004935 ** code generation, and that copy is deleted after code generation. This
004936 ** ensures that the original pExpr is unchanged.
004937 */
004938 void sqlite3ExprIfFalseDup(Parse *pParse, Expr *pExpr, int dest,int jumpIfNull){
004939 sqlite3 *db = pParse->db;
004940 Expr *pCopy = sqlite3ExprDup(db, pExpr, 0);
004941 if( db->mallocFailed==0 ){
004942 sqlite3ExprIfFalse(pParse, pCopy, dest, jumpIfNull);
004943 }
004944 sqlite3ExprDelete(db, pCopy);
004945 }
004946
004947 /*
004948 ** Expression pVar is guaranteed to be an SQL variable. pExpr may be any
004949 ** type of expression.
004950 **
004951 ** If pExpr is a simple SQL value - an integer, real, string, blob
004952 ** or NULL value - then the VDBE currently being prepared is configured
004953 ** to re-prepare each time a new value is bound to variable pVar.
004954 **
004955 ** Additionally, if pExpr is a simple SQL value and the value is the
004956 ** same as that currently bound to variable pVar, non-zero is returned.
004957 ** Otherwise, if the values are not the same or if pExpr is not a simple
004958 ** SQL value, zero is returned.
004959 */
004960 static int exprCompareVariable(Parse *pParse, Expr *pVar, Expr *pExpr){
004961 int res = 0;
004962 int iVar;
004963 sqlite3_value *pL, *pR = 0;
004964
004965 sqlite3ValueFromExpr(pParse->db, pExpr, SQLITE_UTF8, SQLITE_AFF_BLOB, &pR);
004966 if( pR ){
004967 iVar = pVar->iColumn;
004968 sqlite3VdbeSetVarmask(pParse->pVdbe, iVar);
004969 pL = sqlite3VdbeGetBoundValue(pParse->pReprepare, iVar, SQLITE_AFF_BLOB);
004970 if( pL ){
004971 if( sqlite3_value_type(pL)==SQLITE_TEXT ){
004972 sqlite3_value_text(pL); /* Make sure the encoding is UTF-8 */
004973 }
004974 res = 0==sqlite3MemCompare(pL, pR, 0);
004975 }
004976 sqlite3ValueFree(pR);
004977 sqlite3ValueFree(pL);
004978 }
004979
004980 return res;
004981 }
004982
004983 /*
004984 ** Do a deep comparison of two expression trees. Return 0 if the two
004985 ** expressions are completely identical. Return 1 if they differ only
004986 ** by a COLLATE operator at the top level. Return 2 if there are differences
004987 ** other than the top-level COLLATE operator.
004988 **
004989 ** If any subelement of pB has Expr.iTable==(-1) then it is allowed
004990 ** to compare equal to an equivalent element in pA with Expr.iTable==iTab.
004991 **
004992 ** The pA side might be using TK_REGISTER. If that is the case and pB is
004993 ** not using TK_REGISTER but is otherwise equivalent, then still return 0.
004994 **
004995 ** Sometimes this routine will return 2 even if the two expressions
004996 ** really are equivalent. If we cannot prove that the expressions are
004997 ** identical, we return 2 just to be safe. So if this routine
004998 ** returns 2, then you do not really know for certain if the two
004999 ** expressions are the same. But if you get a 0 or 1 return, then you
005000 ** can be sure the expressions are the same. In the places where
005001 ** this routine is used, it does not hurt to get an extra 2 - that
005002 ** just might result in some slightly slower code. But returning
005003 ** an incorrect 0 or 1 could lead to a malfunction.
005004 **
005005 ** If pParse is not NULL then TK_VARIABLE terms in pA with bindings in
005006 ** pParse->pReprepare can be matched against literals in pB. The
005007 ** pParse->pVdbe->expmask bitmask is updated for each variable referenced.
005008 ** If pParse is NULL (the normal case) then any TK_VARIABLE term in
005009 ** Argument pParse should normally be NULL. If it is not NULL and pA or
005010 ** pB causes a return value of 2.
005011 */
005012 int sqlite3ExprCompare(Parse *pParse, Expr *pA, Expr *pB, int iTab){
005013 u32 combinedFlags;
005014 if( pA==0 || pB==0 ){
005015 return pB==pA ? 0 : 2;
005016 }
005017 if( pParse && pA->op==TK_VARIABLE && exprCompareVariable(pParse, pA, pB) ){
005018 return 0;
005019 }
005020 combinedFlags = pA->flags | pB->flags;
005021 if( combinedFlags & EP_IntValue ){
005022 if( (pA->flags&pB->flags&EP_IntValue)!=0 && pA->u.iValue==pB->u.iValue ){
005023 return 0;
005024 }
005025 return 2;
005026 }
005027 if( pA->op!=pB->op || pA->op==TK_RAISE ){
005028 if( pA->op==TK_COLLATE && sqlite3ExprCompare(pParse, pA->pLeft,pB,iTab)<2 ){
005029 return 1;
005030 }
005031 if( pB->op==TK_COLLATE && sqlite3ExprCompare(pParse, pA,pB->pLeft,iTab)<2 ){
005032 return 1;
005033 }
005034 return 2;
005035 }
005036 if( pA->op!=TK_COLUMN && pA->op!=TK_AGG_COLUMN && pA->u.zToken ){
005037 if( pA->op==TK_FUNCTION || pA->op==TK_AGG_FUNCTION ){
005038 if( sqlite3StrICmp(pA->u.zToken,pB->u.zToken)!=0 ) return 2;
005039 #ifndef SQLITE_OMIT_WINDOWFUNC
005040 assert( pA->op==pB->op );
005041 if( ExprHasProperty(pA,EP_WinFunc)!=ExprHasProperty(pB,EP_WinFunc) ){
005042 return 2;
005043 }
005044 if( ExprHasProperty(pA,EP_WinFunc) ){
005045 if( sqlite3WindowCompare(pParse, pA->y.pWin, pB->y.pWin, 1)!=0 ){
005046 return 2;
005047 }
005048 }
005049 #endif
005050 }else if( pA->op==TK_NULL ){
005051 return 0;
005052 }else if( pA->op==TK_COLLATE ){
005053 if( sqlite3_stricmp(pA->u.zToken,pB->u.zToken)!=0 ) return 2;
005054 }else if( ALWAYS(pB->u.zToken!=0) && strcmp(pA->u.zToken,pB->u.zToken)!=0 ){
005055 return 2;
005056 }
005057 }
005058 if( (pA->flags & (EP_Distinct|EP_Commuted))
005059 != (pB->flags & (EP_Distinct|EP_Commuted)) ) return 2;
005060 if( (combinedFlags & EP_TokenOnly)==0 ){
005061 if( combinedFlags & EP_xIsSelect ) return 2;
005062 if( (combinedFlags & EP_FixedCol)==0
005063 && sqlite3ExprCompare(pParse, pA->pLeft, pB->pLeft, iTab) ) return 2;
005064 if( sqlite3ExprCompare(pParse, pA->pRight, pB->pRight, iTab) ) return 2;
005065 if( sqlite3ExprListCompare(pA->x.pList, pB->x.pList, iTab) ) return 2;
005066 if( pA->op!=TK_STRING
005067 && pA->op!=TK_TRUEFALSE
005068 && (combinedFlags & EP_Reduced)==0
005069 ){
005070 if( pA->iColumn!=pB->iColumn ) return 2;
005071 if( pA->op2!=pB->op2 ){
005072 if( pA->op==TK_TRUTH ) return 2;
005073 if( pA->op==TK_FUNCTION && iTab<0 ){
005074 /* Ex: CREATE TABLE t1(a CHECK( a<julianday('now') ));
005075 ** INSERT INTO t1(a) VALUES(julianday('now')+10);
005076 ** Without this test, sqlite3ExprCodeAtInit() will run on the
005077 ** the julianday() of INSERT first, and remember that expression.
005078 ** Then sqlite3ExprCodeInit() will see the julianday() in the CHECK
005079 ** constraint as redundant, reusing the one from the INSERT, even
005080 ** though the julianday() in INSERT lacks the critical NC_IsCheck
005081 ** flag. See ticket [830277d9db6c3ba1] (2019-10-30)
005082 */
005083 return 2;
005084 }
005085 }
005086 if( pA->op!=TK_IN && pA->iTable!=pB->iTable && pA->iTable!=iTab ){
005087 return 2;
005088 }
005089 }
005090 }
005091 return 0;
005092 }
005093
005094 /*
005095 ** Compare two ExprList objects. Return 0 if they are identical and
005096 ** non-zero if they differ in any way.
005097 **
005098 ** If any subelement of pB has Expr.iTable==(-1) then it is allowed
005099 ** to compare equal to an equivalent element in pA with Expr.iTable==iTab.
005100 **
005101 ** This routine might return non-zero for equivalent ExprLists. The
005102 ** only consequence will be disabled optimizations. But this routine
005103 ** must never return 0 if the two ExprList objects are different, or
005104 ** a malfunction will result.
005105 **
005106 ** Two NULL pointers are considered to be the same. But a NULL pointer
005107 ** always differs from a non-NULL pointer.
005108 */
005109 int sqlite3ExprListCompare(ExprList *pA, ExprList *pB, int iTab){
005110 int i;
005111 if( pA==0 && pB==0 ) return 0;
005112 if( pA==0 || pB==0 ) return 1;
005113 if( pA->nExpr!=pB->nExpr ) return 1;
005114 for(i=0; i<pA->nExpr; i++){
005115 Expr *pExprA = pA->a[i].pExpr;
005116 Expr *pExprB = pB->a[i].pExpr;
005117 if( pA->a[i].sortFlags!=pB->a[i].sortFlags ) return 1;
005118 if( sqlite3ExprCompare(0, pExprA, pExprB, iTab) ) return 1;
005119 }
005120 return 0;
005121 }
005122
005123 /*
005124 ** Like sqlite3ExprCompare() except COLLATE operators at the top-level
005125 ** are ignored.
005126 */
005127 int sqlite3ExprCompareSkip(Expr *pA, Expr *pB, int iTab){
005128 return sqlite3ExprCompare(0,
005129 sqlite3ExprSkipCollateAndLikely(pA),
005130 sqlite3ExprSkipCollateAndLikely(pB),
005131 iTab);
005132 }
005133
005134 /*
005135 ** Return non-zero if Expr p can only be true if pNN is not NULL.
005136 **
005137 ** Or if seenNot is true, return non-zero if Expr p can only be
005138 ** non-NULL if pNN is not NULL
005139 */
005140 static int exprImpliesNotNull(
005141 Parse *pParse, /* Parsing context */
005142 Expr *p, /* The expression to be checked */
005143 Expr *pNN, /* The expression that is NOT NULL */
005144 int iTab, /* Table being evaluated */
005145 int seenNot /* Return true only if p can be any non-NULL value */
005146 ){
005147 assert( p );
005148 assert( pNN );
005149 if( sqlite3ExprCompare(pParse, p, pNN, iTab)==0 ){
005150 return pNN->op!=TK_NULL;
005151 }
005152 switch( p->op ){
005153 case TK_IN: {
005154 if( seenNot && ExprHasProperty(p, EP_xIsSelect) ) return 0;
005155 assert( ExprHasProperty(p,EP_xIsSelect)
005156 || (p->x.pList!=0 && p->x.pList->nExpr>0) );
005157 return exprImpliesNotNull(pParse, p->pLeft, pNN, iTab, 1);
005158 }
005159 case TK_BETWEEN: {
005160 ExprList *pList = p->x.pList;
005161 assert( pList!=0 );
005162 assert( pList->nExpr==2 );
005163 if( seenNot ) return 0;
005164 if( exprImpliesNotNull(pParse, pList->a[0].pExpr, pNN, iTab, 1)
005165 || exprImpliesNotNull(pParse, pList->a[1].pExpr, pNN, iTab, 1)
005166 ){
005167 return 1;
005168 }
005169 return exprImpliesNotNull(pParse, p->pLeft, pNN, iTab, 1);
005170 }
005171 case TK_EQ:
005172 case TK_NE:
005173 case TK_LT:
005174 case TK_LE:
005175 case TK_GT:
005176 case TK_GE:
005177 case TK_PLUS:
005178 case TK_MINUS:
005179 case TK_BITOR:
005180 case TK_LSHIFT:
005181 case TK_RSHIFT:
005182 case TK_CONCAT:
005183 seenNot = 1;
005184 /* Fall thru */
005185 case TK_STAR:
005186 case TK_REM:
005187 case TK_BITAND:
005188 case TK_SLASH: {
005189 if( exprImpliesNotNull(pParse, p->pRight, pNN, iTab, seenNot) ) return 1;
005190 /* Fall thru into the next case */
005191 }
005192 case TK_SPAN:
005193 case TK_COLLATE:
005194 case TK_UPLUS:
005195 case TK_UMINUS: {
005196 return exprImpliesNotNull(pParse, p->pLeft, pNN, iTab, seenNot);
005197 }
005198 case TK_TRUTH: {
005199 if( seenNot ) return 0;
005200 if( p->op2!=TK_IS ) return 0;
005201 return exprImpliesNotNull(pParse, p->pLeft, pNN, iTab, 1);
005202 }
005203 case TK_BITNOT:
005204 case TK_NOT: {
005205 return exprImpliesNotNull(pParse, p->pLeft, pNN, iTab, 1);
005206 }
005207 }
005208 return 0;
005209 }
005210
005211 /*
005212 ** Return true if we can prove the pE2 will always be true if pE1 is
005213 ** true. Return false if we cannot complete the proof or if pE2 might
005214 ** be false. Examples:
005215 **
005216 ** pE1: x==5 pE2: x==5 Result: true
005217 ** pE1: x>0 pE2: x==5 Result: false
005218 ** pE1: x=21 pE2: x=21 OR y=43 Result: true
005219 ** pE1: x!=123 pE2: x IS NOT NULL Result: true
005220 ** pE1: x!=?1 pE2: x IS NOT NULL Result: true
005221 ** pE1: x IS NULL pE2: x IS NOT NULL Result: false
005222 ** pE1: x IS ?2 pE2: x IS NOT NULL Reuslt: false
005223 **
005224 ** When comparing TK_COLUMN nodes between pE1 and pE2, if pE2 has
005225 ** Expr.iTable<0 then assume a table number given by iTab.
005226 **
005227 ** If pParse is not NULL, then the values of bound variables in pE1 are
005228 ** compared against literal values in pE2 and pParse->pVdbe->expmask is
005229 ** modified to record which bound variables are referenced. If pParse
005230 ** is NULL, then false will be returned if pE1 contains any bound variables.
005231 **
005232 ** When in doubt, return false. Returning true might give a performance
005233 ** improvement. Returning false might cause a performance reduction, but
005234 ** it will always give the correct answer and is hence always safe.
005235 */
005236 int sqlite3ExprImpliesExpr(Parse *pParse, Expr *pE1, Expr *pE2, int iTab){
005237 if( sqlite3ExprCompare(pParse, pE1, pE2, iTab)==0 ){
005238 return 1;
005239 }
005240 if( pE2->op==TK_OR
005241 && (sqlite3ExprImpliesExpr(pParse, pE1, pE2->pLeft, iTab)
005242 || sqlite3ExprImpliesExpr(pParse, pE1, pE2->pRight, iTab) )
005243 ){
005244 return 1;
005245 }
005246 if( pE2->op==TK_NOTNULL
005247 && exprImpliesNotNull(pParse, pE1, pE2->pLeft, iTab, 0)
005248 ){
005249 return 1;
005250 }
005251 return 0;
005252 }
005253
005254 /*
005255 ** This is the Expr node callback for sqlite3ExprImpliesNonNullRow().
005256 ** If the expression node requires that the table at pWalker->iCur
005257 ** have one or more non-NULL column, then set pWalker->eCode to 1 and abort.
005258 **
005259 ** This routine controls an optimization. False positives (setting
005260 ** pWalker->eCode to 1 when it should not be) are deadly, but false-negatives
005261 ** (never setting pWalker->eCode) is a harmless missed optimization.
005262 */
005263 static int impliesNotNullRow(Walker *pWalker, Expr *pExpr){
005264 testcase( pExpr->op==TK_AGG_COLUMN );
005265 testcase( pExpr->op==TK_AGG_FUNCTION );
005266 if( ExprHasProperty(pExpr, EP_FromJoin) ) return WRC_Prune;
005267 switch( pExpr->op ){
005268 case TK_ISNOT:
005269 case TK_ISNULL:
005270 case TK_NOTNULL:
005271 case TK_IS:
005272 case TK_OR:
005273 case TK_VECTOR:
005274 case TK_CASE:
005275 case TK_IN:
005276 case TK_FUNCTION:
005277 case TK_TRUTH:
005278 testcase( pExpr->op==TK_ISNOT );
005279 testcase( pExpr->op==TK_ISNULL );
005280 testcase( pExpr->op==TK_NOTNULL );
005281 testcase( pExpr->op==TK_IS );
005282 testcase( pExpr->op==TK_OR );
005283 testcase( pExpr->op==TK_VECTOR );
005284 testcase( pExpr->op==TK_CASE );
005285 testcase( pExpr->op==TK_IN );
005286 testcase( pExpr->op==TK_FUNCTION );
005287 testcase( pExpr->op==TK_TRUTH );
005288 return WRC_Prune;
005289 case TK_COLUMN:
005290 if( pWalker->u.iCur==pExpr->iTable ){
005291 pWalker->eCode = 1;
005292 return WRC_Abort;
005293 }
005294 return WRC_Prune;
005295
005296 case TK_AND:
005297 assert( pWalker->eCode==0 );
005298 sqlite3WalkExpr(pWalker, pExpr->pLeft);
005299 if( pWalker->eCode ){
005300 pWalker->eCode = 0;
005301 sqlite3WalkExpr(pWalker, pExpr->pRight);
005302 }
005303 return WRC_Prune;
005304
005305 case TK_BETWEEN:
005306 if( sqlite3WalkExpr(pWalker, pExpr->pLeft)==WRC_Abort ){
005307 assert( pWalker->eCode );
005308 return WRC_Abort;
005309 }
005310 return WRC_Prune;
005311
005312 /* Virtual tables are allowed to use constraints like x=NULL. So
005313 ** a term of the form x=y does not prove that y is not null if x
005314 ** is the column of a virtual table */
005315 case TK_EQ:
005316 case TK_NE:
005317 case TK_LT:
005318 case TK_LE:
005319 case TK_GT:
005320 case TK_GE:
005321 testcase( pExpr->op==TK_EQ );
005322 testcase( pExpr->op==TK_NE );
005323 testcase( pExpr->op==TK_LT );
005324 testcase( pExpr->op==TK_LE );
005325 testcase( pExpr->op==TK_GT );
005326 testcase( pExpr->op==TK_GE );
005327 if( (pExpr->pLeft->op==TK_COLUMN && IsVirtual(pExpr->pLeft->y.pTab))
005328 || (pExpr->pRight->op==TK_COLUMN && IsVirtual(pExpr->pRight->y.pTab))
005329 ){
005330 return WRC_Prune;
005331 }
005332
005333 default:
005334 return WRC_Continue;
005335 }
005336 }
005337
005338 /*
005339 ** Return true (non-zero) if expression p can only be true if at least
005340 ** one column of table iTab is non-null. In other words, return true
005341 ** if expression p will always be NULL or false if every column of iTab
005342 ** is NULL.
005343 **
005344 ** False negatives are acceptable. In other words, it is ok to return
005345 ** zero even if expression p will never be true of every column of iTab
005346 ** is NULL. A false negative is merely a missed optimization opportunity.
005347 **
005348 ** False positives are not allowed, however. A false positive may result
005349 ** in an incorrect answer.
005350 **
005351 ** Terms of p that are marked with EP_FromJoin (and hence that come from
005352 ** the ON or USING clauses of LEFT JOINS) are excluded from the analysis.
005353 **
005354 ** This routine is used to check if a LEFT JOIN can be converted into
005355 ** an ordinary JOIN. The p argument is the WHERE clause. If the WHERE
005356 ** clause requires that some column of the right table of the LEFT JOIN
005357 ** be non-NULL, then the LEFT JOIN can be safely converted into an
005358 ** ordinary join.
005359 */
005360 int sqlite3ExprImpliesNonNullRow(Expr *p, int iTab){
005361 Walker w;
005362 p = sqlite3ExprSkipCollateAndLikely(p);
005363 if( p==0 ) return 0;
005364 if( p->op==TK_NOTNULL ){
005365 p = p->pLeft;
005366 }else{
005367 while( p->op==TK_AND ){
005368 if( sqlite3ExprImpliesNonNullRow(p->pLeft, iTab) ) return 1;
005369 p = p->pRight;
005370 }
005371 }
005372 w.xExprCallback = impliesNotNullRow;
005373 w.xSelectCallback = 0;
005374 w.xSelectCallback2 = 0;
005375 w.eCode = 0;
005376 w.u.iCur = iTab;
005377 sqlite3WalkExpr(&w, p);
005378 return w.eCode;
005379 }
005380
005381 /*
005382 ** An instance of the following structure is used by the tree walker
005383 ** to determine if an expression can be evaluated by reference to the
005384 ** index only, without having to do a search for the corresponding
005385 ** table entry. The IdxCover.pIdx field is the index. IdxCover.iCur
005386 ** is the cursor for the table.
005387 */
005388 struct IdxCover {
005389 Index *pIdx; /* The index to be tested for coverage */
005390 int iCur; /* Cursor number for the table corresponding to the index */
005391 };
005392
005393 /*
005394 ** Check to see if there are references to columns in table
005395 ** pWalker->u.pIdxCover->iCur can be satisfied using the index
005396 ** pWalker->u.pIdxCover->pIdx.
005397 */
005398 static int exprIdxCover(Walker *pWalker, Expr *pExpr){
005399 if( pExpr->op==TK_COLUMN
005400 && pExpr->iTable==pWalker->u.pIdxCover->iCur
005401 && sqlite3TableColumnToIndex(pWalker->u.pIdxCover->pIdx, pExpr->iColumn)<0
005402 ){
005403 pWalker->eCode = 1;
005404 return WRC_Abort;
005405 }
005406 return WRC_Continue;
005407 }
005408
005409 /*
005410 ** Determine if an index pIdx on table with cursor iCur contains will
005411 ** the expression pExpr. Return true if the index does cover the
005412 ** expression and false if the pExpr expression references table columns
005413 ** that are not found in the index pIdx.
005414 **
005415 ** An index covering an expression means that the expression can be
005416 ** evaluated using only the index and without having to lookup the
005417 ** corresponding table entry.
005418 */
005419 int sqlite3ExprCoveredByIndex(
005420 Expr *pExpr, /* The index to be tested */
005421 int iCur, /* The cursor number for the corresponding table */
005422 Index *pIdx /* The index that might be used for coverage */
005423 ){
005424 Walker w;
005425 struct IdxCover xcov;
005426 memset(&w, 0, sizeof(w));
005427 xcov.iCur = iCur;
005428 xcov.pIdx = pIdx;
005429 w.xExprCallback = exprIdxCover;
005430 w.u.pIdxCover = &xcov;
005431 sqlite3WalkExpr(&w, pExpr);
005432 return !w.eCode;
005433 }
005434
005435
005436 /*
005437 ** An instance of the following structure is used by the tree walker
005438 ** to count references to table columns in the arguments of an
005439 ** aggregate function, in order to implement the
005440 ** sqlite3FunctionThisSrc() routine.
005441 */
005442 struct SrcCount {
005443 SrcList *pSrc; /* One particular FROM clause in a nested query */
005444 int nThis; /* Number of references to columns in pSrcList */
005445 int nOther; /* Number of references to columns in other FROM clauses */
005446 };
005447
005448 /*
005449 ** Count the number of references to columns.
005450 */
005451 static int exprSrcCount(Walker *pWalker, Expr *pExpr){
005452 /* There was once a NEVER() on the second term on the grounds that
005453 ** sqlite3FunctionUsesThisSrc() was always called before
005454 ** sqlite3ExprAnalyzeAggregates() and so the TK_COLUMNs have not yet
005455 ** been converted into TK_AGG_COLUMN. But this is no longer true due
005456 ** to window functions - sqlite3WindowRewrite() may now indirectly call
005457 ** FunctionUsesThisSrc() when creating a new sub-select. */
005458 if( pExpr->op==TK_COLUMN || pExpr->op==TK_AGG_COLUMN ){
005459 int i;
005460 struct SrcCount *p = pWalker->u.pSrcCount;
005461 SrcList *pSrc = p->pSrc;
005462 int nSrc = pSrc ? pSrc->nSrc : 0;
005463 for(i=0; i<nSrc; i++){
005464 if( pExpr->iTable==pSrc->a[i].iCursor ) break;
005465 }
005466 if( i<nSrc ){
005467 p->nThis++;
005468 }else if( nSrc==0 || pExpr->iTable<pSrc->a[0].iCursor ){
005469 /* In a well-formed parse tree (no name resolution errors),
005470 ** TK_COLUMN nodes with smaller Expr.iTable values are in an
005471 ** outer context. Those are the only ones to count as "other" */
005472 p->nOther++;
005473 }
005474 }
005475 return WRC_Continue;
005476 }
005477
005478 /*
005479 ** Determine if any of the arguments to the pExpr Function reference
005480 ** pSrcList. Return true if they do. Also return true if the function
005481 ** has no arguments or has only constant arguments. Return false if pExpr
005482 ** references columns but not columns of tables found in pSrcList.
005483 */
005484 int sqlite3FunctionUsesThisSrc(Expr *pExpr, SrcList *pSrcList){
005485 Walker w;
005486 struct SrcCount cnt;
005487 assert( pExpr->op==TK_AGG_FUNCTION );
005488 memset(&w, 0, sizeof(w));
005489 w.xExprCallback = exprSrcCount;
005490 w.xSelectCallback = sqlite3SelectWalkNoop;
005491 w.u.pSrcCount = &cnt;
005492 cnt.pSrc = pSrcList;
005493 cnt.nThis = 0;
005494 cnt.nOther = 0;
005495 sqlite3WalkExprList(&w, pExpr->x.pList);
005496 #ifndef SQLITE_OMIT_WINDOWFUNC
005497 if( ExprHasProperty(pExpr, EP_WinFunc) ){
005498 sqlite3WalkExpr(&w, pExpr->y.pWin->pFilter);
005499 }
005500 #endif
005501 return cnt.nThis>0 || cnt.nOther==0;
005502 }
005503
005504 /*
005505 ** Add a new element to the pAggInfo->aCol[] array. Return the index of
005506 ** the new element. Return a negative number if malloc fails.
005507 */
005508 static int addAggInfoColumn(sqlite3 *db, AggInfo *pInfo){
005509 int i;
005510 pInfo->aCol = sqlite3ArrayAllocate(
005511 db,
005512 pInfo->aCol,
005513 sizeof(pInfo->aCol[0]),
005514 &pInfo->nColumn,
005515 &i
005516 );
005517 return i;
005518 }
005519
005520 /*
005521 ** Add a new element to the pAggInfo->aFunc[] array. Return the index of
005522 ** the new element. Return a negative number if malloc fails.
005523 */
005524 static int addAggInfoFunc(sqlite3 *db, AggInfo *pInfo){
005525 int i;
005526 pInfo->aFunc = sqlite3ArrayAllocate(
005527 db,
005528 pInfo->aFunc,
005529 sizeof(pInfo->aFunc[0]),
005530 &pInfo->nFunc,
005531 &i
005532 );
005533 return i;
005534 }
005535
005536 /*
005537 ** This is the xExprCallback for a tree walker. It is used to
005538 ** implement sqlite3ExprAnalyzeAggregates(). See sqlite3ExprAnalyzeAggregates
005539 ** for additional information.
005540 */
005541 static int analyzeAggregate(Walker *pWalker, Expr *pExpr){
005542 int i;
005543 NameContext *pNC = pWalker->u.pNC;
005544 Parse *pParse = pNC->pParse;
005545 SrcList *pSrcList = pNC->pSrcList;
005546 AggInfo *pAggInfo = pNC->uNC.pAggInfo;
005547
005548 assert( pNC->ncFlags & NC_UAggInfo );
005549 switch( pExpr->op ){
005550 case TK_AGG_COLUMN:
005551 case TK_COLUMN: {
005552 testcase( pExpr->op==TK_AGG_COLUMN );
005553 testcase( pExpr->op==TK_COLUMN );
005554 /* Check to see if the column is in one of the tables in the FROM
005555 ** clause of the aggregate query */
005556 if( ALWAYS(pSrcList!=0) ){
005557 struct SrcList_item *pItem = pSrcList->a;
005558 for(i=0; i<pSrcList->nSrc; i++, pItem++){
005559 struct AggInfo_col *pCol;
005560 assert( !ExprHasProperty(pExpr, EP_TokenOnly|EP_Reduced) );
005561 if( pExpr->iTable==pItem->iCursor ){
005562 /* If we reach this point, it means that pExpr refers to a table
005563 ** that is in the FROM clause of the aggregate query.
005564 **
005565 ** Make an entry for the column in pAggInfo->aCol[] if there
005566 ** is not an entry there already.
005567 */
005568 int k;
005569 pCol = pAggInfo->aCol;
005570 for(k=0; k<pAggInfo->nColumn; k++, pCol++){
005571 if( pCol->iTable==pExpr->iTable &&
005572 pCol->iColumn==pExpr->iColumn ){
005573 break;
005574 }
005575 }
005576 if( (k>=pAggInfo->nColumn)
005577 && (k = addAggInfoColumn(pParse->db, pAggInfo))>=0
005578 ){
005579 pCol = &pAggInfo->aCol[k];
005580 pCol->pTab = pExpr->y.pTab;
005581 pCol->iTable = pExpr->iTable;
005582 pCol->iColumn = pExpr->iColumn;
005583 pCol->iMem = ++pParse->nMem;
005584 pCol->iSorterColumn = -1;
005585 pCol->pExpr = pExpr;
005586 if( pAggInfo->pGroupBy ){
005587 int j, n;
005588 ExprList *pGB = pAggInfo->pGroupBy;
005589 struct ExprList_item *pTerm = pGB->a;
005590 n = pGB->nExpr;
005591 for(j=0; j<n; j++, pTerm++){
005592 Expr *pE = pTerm->pExpr;
005593 if( pE->op==TK_COLUMN && pE->iTable==pExpr->iTable &&
005594 pE->iColumn==pExpr->iColumn ){
005595 pCol->iSorterColumn = j;
005596 break;
005597 }
005598 }
005599 }
005600 if( pCol->iSorterColumn<0 ){
005601 pCol->iSorterColumn = pAggInfo->nSortingColumn++;
005602 }
005603 }
005604 /* There is now an entry for pExpr in pAggInfo->aCol[] (either
005605 ** because it was there before or because we just created it).
005606 ** Convert the pExpr to be a TK_AGG_COLUMN referring to that
005607 ** pAggInfo->aCol[] entry.
005608 */
005609 ExprSetVVAProperty(pExpr, EP_NoReduce);
005610 pExpr->pAggInfo = pAggInfo;
005611 pExpr->op = TK_AGG_COLUMN;
005612 pExpr->iAgg = (i16)k;
005613 break;
005614 } /* endif pExpr->iTable==pItem->iCursor */
005615 } /* end loop over pSrcList */
005616 }
005617 return WRC_Prune;
005618 }
005619 case TK_AGG_FUNCTION: {
005620 if( (pNC->ncFlags & NC_InAggFunc)==0
005621 && pWalker->walkerDepth==pExpr->op2
005622 ){
005623 /* Check to see if pExpr is a duplicate of another aggregate
005624 ** function that is already in the pAggInfo structure
005625 */
005626 struct AggInfo_func *pItem = pAggInfo->aFunc;
005627 for(i=0; i<pAggInfo->nFunc; i++, pItem++){
005628 if( sqlite3ExprCompare(0, pItem->pExpr, pExpr, -1)==0 ){
005629 break;
005630 }
005631 }
005632 if( i>=pAggInfo->nFunc ){
005633 /* pExpr is original. Make a new entry in pAggInfo->aFunc[]
005634 */
005635 u8 enc = ENC(pParse->db);
005636 i = addAggInfoFunc(pParse->db, pAggInfo);
005637 if( i>=0 ){
005638 assert( !ExprHasProperty(pExpr, EP_xIsSelect) );
005639 pItem = &pAggInfo->aFunc[i];
005640 pItem->pExpr = pExpr;
005641 pItem->iMem = ++pParse->nMem;
005642 assert( !ExprHasProperty(pExpr, EP_IntValue) );
005643 pItem->pFunc = sqlite3FindFunction(pParse->db,
005644 pExpr->u.zToken,
005645 pExpr->x.pList ? pExpr->x.pList->nExpr : 0, enc, 0);
005646 if( pExpr->flags & EP_Distinct ){
005647 pItem->iDistinct = pParse->nTab++;
005648 }else{
005649 pItem->iDistinct = -1;
005650 }
005651 }
005652 }
005653 /* Make pExpr point to the appropriate pAggInfo->aFunc[] entry
005654 */
005655 assert( !ExprHasProperty(pExpr, EP_TokenOnly|EP_Reduced) );
005656 ExprSetVVAProperty(pExpr, EP_NoReduce);
005657 pExpr->iAgg = (i16)i;
005658 pExpr->pAggInfo = pAggInfo;
005659 return WRC_Prune;
005660 }else{
005661 return WRC_Continue;
005662 }
005663 }
005664 }
005665 return WRC_Continue;
005666 }
005667 static int analyzeAggregatesInSelect(Walker *pWalker, Select *pSelect){
005668 UNUSED_PARAMETER(pSelect);
005669 pWalker->walkerDepth++;
005670 return WRC_Continue;
005671 }
005672 static void analyzeAggregatesInSelectEnd(Walker *pWalker, Select *pSelect){
005673 UNUSED_PARAMETER(pSelect);
005674 pWalker->walkerDepth--;
005675 }
005676
005677 /*
005678 ** Analyze the pExpr expression looking for aggregate functions and
005679 ** for variables that need to be added to AggInfo object that pNC->pAggInfo
005680 ** points to. Additional entries are made on the AggInfo object as
005681 ** necessary.
005682 **
005683 ** This routine should only be called after the expression has been
005684 ** analyzed by sqlite3ResolveExprNames().
005685 */
005686 void sqlite3ExprAnalyzeAggregates(NameContext *pNC, Expr *pExpr){
005687 Walker w;
005688 w.xExprCallback = analyzeAggregate;
005689 w.xSelectCallback = analyzeAggregatesInSelect;
005690 w.xSelectCallback2 = analyzeAggregatesInSelectEnd;
005691 w.walkerDepth = 0;
005692 w.u.pNC = pNC;
005693 w.pParse = 0;
005694 assert( pNC->pSrcList!=0 );
005695 sqlite3WalkExpr(&w, pExpr);
005696 }
005697
005698 /*
005699 ** Call sqlite3ExprAnalyzeAggregates() for every expression in an
005700 ** expression list. Return the number of errors.
005701 **
005702 ** If an error is found, the analysis is cut short.
005703 */
005704 void sqlite3ExprAnalyzeAggList(NameContext *pNC, ExprList *pList){
005705 struct ExprList_item *pItem;
005706 int i;
005707 if( pList ){
005708 for(pItem=pList->a, i=0; i<pList->nExpr; i++, pItem++){
005709 sqlite3ExprAnalyzeAggregates(pNC, pItem->pExpr);
005710 }
005711 }
005712 }
005713
005714 /*
005715 ** Allocate a single new register for use to hold some intermediate result.
005716 */
005717 int sqlite3GetTempReg(Parse *pParse){
005718 if( pParse->nTempReg==0 ){
005719 return ++pParse->nMem;
005720 }
005721 return pParse->aTempReg[--pParse->nTempReg];
005722 }
005723
005724 /*
005725 ** Deallocate a register, making available for reuse for some other
005726 ** purpose.
005727 */
005728 void sqlite3ReleaseTempReg(Parse *pParse, int iReg){
005729 if( iReg ){
005730 sqlite3VdbeReleaseRegisters(pParse, iReg, 1, 0);
005731 if( pParse->nTempReg<ArraySize(pParse->aTempReg) ){
005732 pParse->aTempReg[pParse->nTempReg++] = iReg;
005733 }
005734 }
005735 }
005736
005737 /*
005738 ** Allocate or deallocate a block of nReg consecutive registers.
005739 */
005740 int sqlite3GetTempRange(Parse *pParse, int nReg){
005741 int i, n;
005742 if( nReg==1 ) return sqlite3GetTempReg(pParse);
005743 i = pParse->iRangeReg;
005744 n = pParse->nRangeReg;
005745 if( nReg<=n ){
005746 pParse->iRangeReg += nReg;
005747 pParse->nRangeReg -= nReg;
005748 }else{
005749 i = pParse->nMem+1;
005750 pParse->nMem += nReg;
005751 }
005752 return i;
005753 }
005754 void sqlite3ReleaseTempRange(Parse *pParse, int iReg, int nReg){
005755 if( nReg==1 ){
005756 sqlite3ReleaseTempReg(pParse, iReg);
005757 return;
005758 }
005759 sqlite3VdbeReleaseRegisters(pParse, iReg, nReg, 0);
005760 if( nReg>pParse->nRangeReg ){
005761 pParse->nRangeReg = nReg;
005762 pParse->iRangeReg = iReg;
005763 }
005764 }
005765
005766 /*
005767 ** Mark all temporary registers as being unavailable for reuse.
005768 **
005769 ** Always invoke this procedure after coding a subroutine or co-routine
005770 ** that might be invoked from other parts of the code, to ensure that
005771 ** the sub/co-routine does not use registers in common with the code that
005772 ** invokes the sub/co-routine.
005773 */
005774 void sqlite3ClearTempRegCache(Parse *pParse){
005775 pParse->nTempReg = 0;
005776 pParse->nRangeReg = 0;
005777 }
005778
005779 /*
005780 ** Validate that no temporary register falls within the range of
005781 ** iFirst..iLast, inclusive. This routine is only call from within assert()
005782 ** statements.
005783 */
005784 #ifdef SQLITE_DEBUG
005785 int sqlite3NoTempsInRange(Parse *pParse, int iFirst, int iLast){
005786 int i;
005787 if( pParse->nRangeReg>0
005788 && pParse->iRangeReg+pParse->nRangeReg > iFirst
005789 && pParse->iRangeReg <= iLast
005790 ){
005791 return 0;
005792 }
005793 for(i=0; i<pParse->nTempReg; i++){
005794 if( pParse->aTempReg[i]>=iFirst && pParse->aTempReg[i]<=iLast ){
005795 return 0;
005796 }
005797 }
005798 return 1;
005799 }
005800 #endif /* SQLITE_DEBUG */