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/*
** 2001 September 15
**
** The author disclaims copyright to this source code. In place of
** a legal notice, here is a blessing:
**
** May you do good and not evil.
** May you find forgiveness for yourself and forgive others.
** May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains routines used for analyzing expressions and
** for generating VDBE code that evaluates expressions in SQLite.
*/
#include "sqliteInt.h"
/* Forward declarations */
static void exprCodeBetween(Parse*,Expr*,int,void(*)(Parse*,Expr*,int,int),int);
static int exprCodeVector(Parse *pParse, Expr *p, int *piToFree);
/*
** Return the affinity character for a single column of a table.
*/
char sqlite3TableColumnAffinity(Table *pTab, int iCol){
assert( iCol<pTab->nCol );
return iCol>=0 ? pTab->aCol[iCol].affinity : SQLITE_AFF_INTEGER;
}
/*
** Return the 'affinity' of the expression pExpr if any.
**
** If pExpr is a column, a reference to a column via an 'AS' alias,
** or a sub-select with a column as the return value, then the
** affinity of that column is returned. Otherwise, 0x00 is returned,
** indicating no affinity for the expression.
**
** i.e. the WHERE clause expressions in the following statements all
** have an affinity:
**
** CREATE TABLE t1(a);
** SELECT * FROM t1 WHERE a;
** SELECT a AS b FROM t1 WHERE b;
** SELECT * FROM t1 WHERE (select a from t1);
*/
char sqlite3ExprAffinity(Expr *pExpr){
int op;
while( ExprHasProperty(pExpr, EP_Skip) ){
assert( pExpr->op==TK_COLLATE );
pExpr = pExpr->pLeft;
assert( pExpr!=0 );
}
op = pExpr->op;
if( op==TK_SELECT ){
assert( pExpr->flags&EP_xIsSelect );
return sqlite3ExprAffinity(pExpr->x.pSelect->pEList->a[0].pExpr);
}
if( op==TK_REGISTER ) op = pExpr->op2;
#ifndef SQLITE_OMIT_CAST
if( op==TK_CAST ){
assert( !ExprHasProperty(pExpr, EP_IntValue) );
return sqlite3AffinityType(pExpr->u.zToken, 0);
}
#endif
if( (op==TK_AGG_COLUMN || op==TK_COLUMN) && pExpr->y.pTab ){
return sqlite3TableColumnAffinity(pExpr->y.pTab, pExpr->iColumn);
}
if( op==TK_SELECT_COLUMN ){
assert( pExpr->pLeft->flags&EP_xIsSelect );
return sqlite3ExprAffinity(
pExpr->pLeft->x.pSelect->pEList->a[pExpr->iColumn].pExpr
);
}
return pExpr->affExpr;
}
/*
** Set the collating sequence for expression pExpr to be the collating
** sequence named by pToken. Return a pointer to a new Expr node that
** implements the COLLATE operator.
**
** If a memory allocation error occurs, that fact is recorded in pParse->db
** and the pExpr parameter is returned unchanged.
*/
Expr *sqlite3ExprAddCollateToken(
Parse *pParse, /* Parsing context */
Expr *pExpr, /* Add the "COLLATE" clause to this expression */
const Token *pCollName, /* Name of collating sequence */
int dequote /* True to dequote pCollName */
){
if( pCollName->n>0 ){
Expr *pNew = sqlite3ExprAlloc(pParse->db, TK_COLLATE, pCollName, dequote);
if( pNew ){
pNew->pLeft = pExpr;
pNew->flags |= EP_Collate|EP_Skip;
pExpr = pNew;
}
}
return pExpr;
}
Expr *sqlite3ExprAddCollateString(Parse *pParse, Expr *pExpr, const char *zC){
Token s;
assert( zC!=0 );
sqlite3TokenInit(&s, (char*)zC);
return sqlite3ExprAddCollateToken(pParse, pExpr, &s, 0);
}
/*
** Skip over any TK_COLLATE operators.
*/
Expr *sqlite3ExprSkipCollate(Expr *pExpr){
while( pExpr && ExprHasProperty(pExpr, EP_Skip) ){
assert( pExpr->op==TK_COLLATE );
pExpr = pExpr->pLeft;
}
return pExpr;
}
/*
** Skip over any TK_COLLATE operators and/or any unlikely()
** or likelihood() or likely() functions at the root of an
** expression.
*/
Expr *sqlite3ExprSkipCollateAndLikely(Expr *pExpr){
while( pExpr && ExprHasProperty(pExpr, EP_Skip|EP_Unlikely) ){
if( ExprHasProperty(pExpr, EP_Unlikely) ){
assert( !ExprHasProperty(pExpr, EP_xIsSelect) );
assert( pExpr->x.pList->nExpr>0 );
assert( pExpr->op==TK_FUNCTION );
pExpr = pExpr->x.pList->a[0].pExpr;
}else{
assert( pExpr->op==TK_COLLATE );
pExpr = pExpr->pLeft;
}
}
return pExpr;
}
/*
** Return the collation sequence for the expression pExpr. If
** there is no defined collating sequence, return NULL.
**
** See also: sqlite3ExprNNCollSeq()
**
** The sqlite3ExprNNCollSeq() works the same exact that it returns the
** default collation if pExpr has no defined collation.
**
** The collating sequence might be determined by a COLLATE operator
** or by the presence of a column with a defined collating sequence.
** COLLATE operators take first precedence. Left operands take
** precedence over right operands.
*/
CollSeq *sqlite3ExprCollSeq(Parse *pParse, Expr *pExpr){
sqlite3 *db = pParse->db;
CollSeq *pColl = 0;
Expr *p = pExpr;
while( p ){
int op = p->op;
if( op==TK_REGISTER ) op = p->op2;
if( (op==TK_AGG_COLUMN || op==TK_COLUMN || op==TK_TRIGGER)
&& p->y.pTab!=0
){
/* op==TK_REGISTER && p->y.pTab!=0 happens when pExpr was originally
** a TK_COLUMN but was previously evaluated and cached in a register */
int j = p->iColumn;
if( j>=0 ){
const char *zColl = p->y.pTab->aCol[j].zColl;
pColl = sqlite3FindCollSeq(db, ENC(db), zColl, 0);
}
break;
}
if( op==TK_CAST || op==TK_UPLUS ){
p = p->pLeft;
continue;
}
if( op==TK_COLLATE ){
pColl = sqlite3GetCollSeq(pParse, ENC(db), 0, p->u.zToken);
break;
}
if( p->flags & EP_Collate ){
if( p->pLeft && (p->pLeft->flags & EP_Collate)!=0 ){
p = p->pLeft;
}else{
Expr *pNext = p->pRight;
/* The Expr.x union is never used at the same time as Expr.pRight */
assert( p->x.pList==0 || p->pRight==0 );
/* p->flags holds EP_Collate and p->pLeft->flags does not. And
** p->x.pSelect cannot. So if p->x.pLeft exists, it must hold at
** least one EP_Collate. Thus the following two ALWAYS. */
if( p->x.pList!=0 && ALWAYS(!ExprHasProperty(p, EP_xIsSelect)) ){
int i;
for(i=0; ALWAYS(i<p->x.pList->nExpr); i++){
if( ExprHasProperty(p->x.pList->a[i].pExpr, EP_Collate) ){
pNext = p->x.pList->a[i].pExpr;
break;
}
}
}
p = pNext;
}
}else{
break;
}
}
if( sqlite3CheckCollSeq(pParse, pColl) ){
pColl = 0;
}
return pColl;
}
/*
** Return the collation sequence for the expression pExpr. If
** there is no defined collating sequence, return a pointer to the
** defautl collation sequence.
**
** See also: sqlite3ExprCollSeq()
**
** The sqlite3ExprCollSeq() routine works the same except that it
** returns NULL if there is no defined collation.
*/
CollSeq *sqlite3ExprNNCollSeq(Parse *pParse, Expr *pExpr){
CollSeq *p = sqlite3ExprCollSeq(pParse, pExpr);
if( p==0 ) p = pParse->db->pDfltColl;
assert( p!=0 );
return p;
}
/*
** Return TRUE if the two expressions have equivalent collating sequences.
*/
int sqlite3ExprCollSeqMatch(Parse *pParse, Expr *pE1, Expr *pE2){
CollSeq *pColl1 = sqlite3ExprNNCollSeq(pParse, pE1);
CollSeq *pColl2 = sqlite3ExprNNCollSeq(pParse, pE2);
return sqlite3StrICmp(pColl1->zName, pColl2->zName)==0;
}
/*
** pExpr is an operand of a comparison operator. aff2 is the
** type affinity of the other operand. This routine returns the
** type affinity that should be used for the comparison operator.
*/
char sqlite3CompareAffinity(Expr *pExpr, char aff2){
char aff1 = sqlite3ExprAffinity(pExpr);
if( aff1>SQLITE_AFF_NONE && aff2>SQLITE_AFF_NONE ){
/* Both sides of the comparison are columns. If one has numeric
** affinity, use that. Otherwise use no affinity.
*/
if( sqlite3IsNumericAffinity(aff1) || sqlite3IsNumericAffinity(aff2) ){
return SQLITE_AFF_NUMERIC;
}else{
return SQLITE_AFF_BLOB;
}
}else{
/* One side is a column, the other is not. Use the columns affinity. */
assert( aff1<=SQLITE_AFF_NONE || aff2<=SQLITE_AFF_NONE );
return (aff1<=SQLITE_AFF_NONE ? aff2 : aff1) | SQLITE_AFF_NONE;
}
}
/*
** pExpr is a comparison operator. Return the type affinity that should
** be applied to both operands prior to doing the comparison.
*/
static char comparisonAffinity(Expr *pExpr){
char aff;
assert( pExpr->op==TK_EQ || pExpr->op==TK_IN || pExpr->op==TK_LT ||
pExpr->op==TK_GT || pExpr->op==TK_GE || pExpr->op==TK_LE ||
pExpr->op==TK_NE || pExpr->op==TK_IS || pExpr->op==TK_ISNOT );
assert( pExpr->pLeft );
aff = sqlite3ExprAffinity(pExpr->pLeft);
if( pExpr->pRight ){
aff = sqlite3CompareAffinity(pExpr->pRight, aff);
}else if( ExprHasProperty(pExpr, EP_xIsSelect) ){
aff = sqlite3CompareAffinity(pExpr->x.pSelect->pEList->a[0].pExpr, aff);
}else if( aff==0 ){
aff = SQLITE_AFF_BLOB;
}
return aff;
}
/*
** pExpr is a comparison expression, eg. '=', '<', IN(...) etc.
** idx_affinity is the affinity of an indexed column. Return true
** if the index with affinity idx_affinity may be used to implement
** the comparison in pExpr.
*/
int sqlite3IndexAffinityOk(Expr *pExpr, char idx_affinity){
char aff = comparisonAffinity(pExpr);
if( aff<SQLITE_AFF_TEXT ){
return 1;
}
if( aff==SQLITE_AFF_TEXT ){
return idx_affinity==SQLITE_AFF_TEXT;
}
return sqlite3IsNumericAffinity(idx_affinity);
}
/*
** Return the P5 value that should be used for a binary comparison
** opcode (OP_Eq, OP_Ge etc.) used to compare pExpr1 and pExpr2.
*/
static u8 binaryCompareP5(Expr *pExpr1, Expr *pExpr2, int jumpIfNull){
u8 aff = (char)sqlite3ExprAffinity(pExpr2);
aff = (u8)sqlite3CompareAffinity(pExpr1, aff) | (u8)jumpIfNull;
return aff;
}
/*
** Return a pointer to the collation sequence that should be used by
** a binary comparison operator comparing pLeft and pRight.
**
** If the left hand expression has a collating sequence type, then it is
** used. Otherwise the collation sequence for the right hand expression
** is used, or the default (BINARY) if neither expression has a collating
** type.
**
** Argument pRight (but not pLeft) may be a null pointer. In this case,
** it is not considered.
*/
CollSeq *sqlite3BinaryCompareCollSeq(
Parse *pParse,
Expr *pLeft,
Expr *pRight
){
CollSeq *pColl;
assert( pLeft );
if( pLeft->flags & EP_Collate ){
pColl = sqlite3ExprCollSeq(pParse, pLeft);
}else if( pRight && (pRight->flags & EP_Collate)!=0 ){
pColl = sqlite3ExprCollSeq(pParse, pRight);
}else{
pColl = sqlite3ExprCollSeq(pParse, pLeft);
if( !pColl ){
pColl = sqlite3ExprCollSeq(pParse, pRight);
}
}
return pColl;
}
/*
** Generate code for a comparison operator.
*/
static int codeCompare(
Parse *pParse, /* The parsing (and code generating) context */
Expr *pLeft, /* The left operand */
Expr *pRight, /* The right operand */
int opcode, /* The comparison opcode */
int in1, int in2, /* Register holding operands */
int dest, /* Jump here if true. */
int jumpIfNull /* If true, jump if either operand is NULL */
){
int p5;
int addr;
CollSeq *p4;
p4 = sqlite3BinaryCompareCollSeq(pParse, pLeft, pRight);
p5 = binaryCompareP5(pLeft, pRight, jumpIfNull);
addr = sqlite3VdbeAddOp4(pParse->pVdbe, opcode, in2, dest, in1,
(void*)p4, P4_COLLSEQ);
sqlite3VdbeChangeP5(pParse->pVdbe, (u8)p5);
return addr;
}
/*
** Return true if expression pExpr is a vector, or false otherwise.
**
** A vector is defined as any expression that results in two or more
** columns of result. Every TK_VECTOR node is an vector because the
** parser will not generate a TK_VECTOR with fewer than two entries.
** But a TK_SELECT might be either a vector or a scalar. It is only
** considered a vector if it has two or more result columns.
*/
int sqlite3ExprIsVector(Expr *pExpr){
return sqlite3ExprVectorSize(pExpr)>1;
}
/*
** If the expression passed as the only argument is of type TK_VECTOR
** return the number of expressions in the vector. Or, if the expression
** is a sub-select, return the number of columns in the sub-select. For
** any other type of expression, return 1.
*/
int sqlite3ExprVectorSize(Expr *pExpr){
u8 op = pExpr->op;
if( op==TK_REGISTER ) op = pExpr->op2;
if( op==TK_VECTOR ){
return pExpr->x.pList->nExpr;
}else if( op==TK_SELECT ){
return pExpr->x.pSelect->pEList->nExpr;
}else{
return 1;
}
}
/*
** Return a pointer to a subexpression of pVector that is the i-th
** column of the vector (numbered starting with 0). The caller must
** ensure that i is within range.
**
** If pVector is really a scalar (and "scalar" here includes subqueries
** that return a single column!) then return pVector unmodified.
**
** pVector retains ownership of the returned subexpression.
**
** If the vector is a (SELECT ...) then the expression returned is
** just the expression for the i-th term of the result set, and may
** not be ready for evaluation because the table cursor has not yet
** been positioned.
*/
Expr *sqlite3VectorFieldSubexpr(Expr *pVector, int i){
assert( i<sqlite3ExprVectorSize(pVector) );
if( sqlite3ExprIsVector(pVector) ){
assert( pVector->op2==0 || pVector->op==TK_REGISTER );
if( pVector->op==TK_SELECT || pVector->op2==TK_SELECT ){
return pVector->x.pSelect->pEList->a[i].pExpr;
}else{
return pVector->x.pList->a[i].pExpr;
}
}
return pVector;
}
/*
** Compute and return a new Expr object which when passed to
** sqlite3ExprCode() will generate all necessary code to compute
** the iField-th column of the vector expression pVector.
**
** It is ok for pVector to be a scalar (as long as iField==0).
** In that case, this routine works like sqlite3ExprDup().
**
** The caller owns the returned Expr object and is responsible for
** ensuring that the returned value eventually gets freed.
**
** The caller retains ownership of pVector. If pVector is a TK_SELECT,
** then the returned object will reference pVector and so pVector must remain
** valid for the life of the returned object. If pVector is a TK_VECTOR
** or a scalar expression, then it can be deleted as soon as this routine
** returns.
**
** A trick to cause a TK_SELECT pVector to be deleted together with
** the returned Expr object is to attach the pVector to the pRight field
** of the returned TK_SELECT_COLUMN Expr object.
*/
Expr *sqlite3ExprForVectorField(
Parse *pParse, /* Parsing context */
Expr *pVector, /* The vector. List of expressions or a sub-SELECT */
int iField /* Which column of the vector to return */
){
Expr *pRet;
if( pVector->op==TK_SELECT ){
assert( pVector->flags & EP_xIsSelect );
/* The TK_SELECT_COLUMN Expr node:
**
** pLeft: pVector containing TK_SELECT. Not deleted.
** pRight: not used. But recursively deleted.
** iColumn: Index of a column in pVector
** iTable: 0 or the number of columns on the LHS of an assignment
** pLeft->iTable: First in an array of register holding result, or 0
** if the result is not yet computed.
**
** sqlite3ExprDelete() specifically skips the recursive delete of
** pLeft on TK_SELECT_COLUMN nodes. But pRight is followed, so pVector
** can be attached to pRight to cause this node to take ownership of
** pVector. Typically there will be multiple TK_SELECT_COLUMN nodes
** with the same pLeft pointer to the pVector, but only one of them
** will own the pVector.
*/
pRet = sqlite3PExpr(pParse, TK_SELECT_COLUMN, 0, 0);
if( pRet ){
pRet->iColumn = iField;
pRet->pLeft = pVector;
}
assert( pRet==0 || pRet->iTable==0 );
}else{
if( pVector->op==TK_VECTOR ) pVector = pVector->x.pList->a[iField].pExpr;
pRet = sqlite3ExprDup(pParse->db, pVector, 0);
sqlite3RenameTokenRemap(pParse, pRet, pVector);
}
return pRet;
}
/*
** If expression pExpr is of type TK_SELECT, generate code to evaluate
** it. Return the register in which the result is stored (or, if the
** sub-select returns more than one column, the first in an array
** of registers in which the result is stored).
**
** If pExpr is not a TK_SELECT expression, return 0.
*/
static int exprCodeSubselect(Parse *pParse, Expr *pExpr){
int reg = 0;
#ifndef SQLITE_OMIT_SUBQUERY
if( pExpr->op==TK_SELECT ){
reg = sqlite3CodeSubselect(pParse, pExpr);
}
#endif
return reg;
}
/*
** Argument pVector points to a vector expression - either a TK_VECTOR
** or TK_SELECT that returns more than one column. This function returns
** the register number of a register that contains the value of
** element iField of the vector.
**
** If pVector is a TK_SELECT expression, then code for it must have
** already been generated using the exprCodeSubselect() routine. In this
** case parameter regSelect should be the first in an array of registers
** containing the results of the sub-select.
**
** If pVector is of type TK_VECTOR, then code for the requested field
** is generated. In this case (*pRegFree) may be set to the number of
** a temporary register to be freed by the caller before returning.
**
** Before returning, output parameter (*ppExpr) is set to point to the
** Expr object corresponding to element iElem of the vector.
*/
static int exprVectorRegister(
Parse *pParse, /* Parse context */
Expr *pVector, /* Vector to extract element from */
int iField, /* Field to extract from pVector */
int regSelect, /* First in array of registers */
Expr **ppExpr, /* OUT: Expression element */
int *pRegFree /* OUT: Temp register to free */
){
u8 op = pVector->op;
assert( op==TK_VECTOR || op==TK_REGISTER || op==TK_SELECT );
if( op==TK_REGISTER ){
*ppExpr = sqlite3VectorFieldSubexpr(pVector, iField);
return pVector->iTable+iField;
}
if( op==TK_SELECT ){
*ppExpr = pVector->x.pSelect->pEList->a[iField].pExpr;
return regSelect+iField;
}
*ppExpr = pVector->x.pList->a[iField].pExpr;
return sqlite3ExprCodeTemp(pParse, *ppExpr, pRegFree);
}
/*
** Expression pExpr is a comparison between two vector values. Compute
** the result of the comparison (1, 0, or NULL) and write that
** result into register dest.
**
** The caller must satisfy the following preconditions:
**
** if pExpr->op==TK_IS: op==TK_EQ and p5==SQLITE_NULLEQ
** if pExpr->op==TK_ISNOT: op==TK_NE and p5==SQLITE_NULLEQ
** otherwise: op==pExpr->op and p5==0
*/
static void codeVectorCompare(
Parse *pParse, /* Code generator context */
Expr *pExpr, /* The comparison operation */
int dest, /* Write results into this register */
u8 op, /* Comparison operator */
u8 p5 /* SQLITE_NULLEQ or zero */
){
Vdbe *v = pParse->pVdbe;
Expr *pLeft = pExpr->pLeft;
Expr *pRight = pExpr->pRight;
int nLeft = sqlite3ExprVectorSize(pLeft);
int i;
int regLeft = 0;
int regRight = 0;
u8 opx = op;
int addrDone = sqlite3VdbeMakeLabel(pParse);
if( nLeft!=sqlite3ExprVectorSize(pRight) ){
sqlite3ErrorMsg(pParse, "row value misused");
return;
}
assert( pExpr->op==TK_EQ || pExpr->op==TK_NE
|| pExpr->op==TK_IS || pExpr->op==TK_ISNOT
|| pExpr->op==TK_LT || pExpr->op==TK_GT
|| pExpr->op==TK_LE || pExpr->op==TK_GE
);
assert( pExpr->op==op || (pExpr->op==TK_IS && op==TK_EQ)
|| (pExpr->op==TK_ISNOT && op==TK_NE) );
assert( p5==0 || pExpr->op!=op );
assert( p5==SQLITE_NULLEQ || pExpr->op==op );
p5 |= SQLITE_STOREP2;
if( opx==TK_LE ) opx = TK_LT;
if( opx==TK_GE ) opx = TK_GT;
regLeft = exprCodeSubselect(pParse, pLeft);
regRight = exprCodeSubselect(pParse, pRight);
for(i=0; 1 /*Loop exits by "break"*/; i++){
int regFree1 = 0, regFree2 = 0;
Expr *pL, *pR;
int r1, r2;
assert( i>=0 && i<nLeft );
r1 = exprVectorRegister(pParse, pLeft, i, regLeft, &pL, &regFree1);
r2 = exprVectorRegister(pParse, pRight, i, regRight, &pR, &regFree2);
codeCompare(pParse, pL, pR, opx, r1, r2, dest, p5);
testcase(op==OP_Lt); VdbeCoverageIf(v,op==OP_Lt);
testcase(op==OP_Le); VdbeCoverageIf(v,op==OP_Le);
testcase(op==OP_Gt); VdbeCoverageIf(v,op==OP_Gt);
testcase(op==OP_Ge); VdbeCoverageIf(v,op==OP_Ge);
testcase(op==OP_Eq); VdbeCoverageIf(v,op==OP_Eq);
testcase(op==OP_Ne); VdbeCoverageIf(v,op==OP_Ne);
sqlite3ReleaseTempReg(pParse, regFree1);
sqlite3ReleaseTempReg(pParse, regFree2);
if( i==nLeft-1 ){
break;
}
if( opx==TK_EQ ){
sqlite3VdbeAddOp2(v, OP_IfNot, dest, addrDone); VdbeCoverage(v);
p5 |= SQLITE_KEEPNULL;
}else if( opx==TK_NE ){
sqlite3VdbeAddOp2(v, OP_If, dest, addrDone); VdbeCoverage(v);
p5 |= SQLITE_KEEPNULL;
}else{
assert( op==TK_LT || op==TK_GT || op==TK_LE || op==TK_GE );
sqlite3VdbeAddOp2(v, OP_ElseNotEq, 0, addrDone);
VdbeCoverageIf(v, op==TK_LT);
VdbeCoverageIf(v, op==TK_GT);
VdbeCoverageIf(v, op==TK_LE);
VdbeCoverageIf(v, op==TK_GE);
if( i==nLeft-2 ) opx = op;
}
}
sqlite3VdbeResolveLabel(v, addrDone);
}
#if SQLITE_MAX_EXPR_DEPTH>0
/*
** Check that argument nHeight is less than or equal to the maximum
** expression depth allowed. If it is not, leave an error message in
** pParse.
*/
int sqlite3ExprCheckHeight(Parse *pParse, int nHeight){
int rc = SQLITE_OK;
int mxHeight = pParse->db->aLimit[SQLITE_LIMIT_EXPR_DEPTH];
if( nHeight>mxHeight ){
sqlite3ErrorMsg(pParse,
"Expression tree is too large (maximum depth %d)", mxHeight
);
rc = SQLITE_ERROR;
}
return rc;
}
/* The following three functions, heightOfExpr(), heightOfExprList()
** and heightOfSelect(), are used to determine the maximum height
** of any expression tree referenced by the structure passed as the
** first argument.
**
** If this maximum height is greater than the current value pointed
** to by pnHeight, the second parameter, then set *pnHeight to that
** value.
*/
static void heightOfExpr(Expr *p, int *pnHeight){
if( p ){
if( p->nHeight>*pnHeight ){
*pnHeight = p->nHeight;
}
}
}
static void heightOfExprList(ExprList *p, int *pnHeight){
if( p ){
int i;
for(i=0; i<p->nExpr; i++){
heightOfExpr(p->a[i].pExpr, pnHeight);
}
}
}
static void heightOfSelect(Select *pSelect, int *pnHeight){
Select *p;
for(p=pSelect; p; p=p->pPrior){
heightOfExpr(p->pWhere, pnHeight);
heightOfExpr(p->pHaving, pnHeight);
heightOfExpr(p->pLimit, pnHeight);
heightOfExprList(p->pEList, pnHeight);
heightOfExprList(p->pGroupBy, pnHeight);
heightOfExprList(p->pOrderBy, pnHeight);
}
}
/*
** Set the Expr.nHeight variable in the structure passed as an
** argument. An expression with no children, Expr.pList or
** Expr.pSelect member has a height of 1. Any other expression
** has a height equal to the maximum height of any other
** referenced Expr plus one.
**
** Also propagate EP_Propagate flags up from Expr.x.pList to Expr.flags,
** if appropriate.
*/
static void exprSetHeight(Expr *p){
int nHeight = 0;
heightOfExpr(p->pLeft, &nHeight);
heightOfExpr(p->pRight, &nHeight);
if( ExprHasProperty(p, EP_xIsSelect) ){
heightOfSelect(p->x.pSelect, &nHeight);
}else if( p->x.pList ){
heightOfExprList(p->x.pList, &nHeight);
p->flags |= EP_Propagate & sqlite3ExprListFlags(p->x.pList);
}
p->nHeight = nHeight + 1;
}
/*
** Set the Expr.nHeight variable using the exprSetHeight() function. If
** the height is greater than the maximum allowed expression depth,
** leave an error in pParse.
**
** Also propagate all EP_Propagate flags from the Expr.x.pList into
** Expr.flags.
*/
void sqlite3ExprSetHeightAndFlags(Parse *pParse, Expr *p){
if( pParse->nErr ) return;
exprSetHeight(p);
sqlite3ExprCheckHeight(pParse, p->nHeight);
}
/*
** Return the maximum height of any expression tree referenced
** by the select statement passed as an argument.
*/
int sqlite3SelectExprHeight(Select *p){
int nHeight = 0;
heightOfSelect(p, &nHeight);
return nHeight;
}
#else /* ABOVE: Height enforcement enabled. BELOW: Height enforcement off */
/*
** Propagate all EP_Propagate flags from the Expr.x.pList into
** Expr.flags.
*/
void sqlite3ExprSetHeightAndFlags(Parse *pParse, Expr *p){
if( p && p->x.pList && !ExprHasProperty(p, EP_xIsSelect) ){
p->flags |= EP_Propagate & sqlite3ExprListFlags(p->x.pList);
}
}
#define exprSetHeight(y)
#endif /* SQLITE_MAX_EXPR_DEPTH>0 */
/*
** This routine is the core allocator for Expr nodes.
**
** Construct a new expression node and return a pointer to it. Memory
** for this node and for the pToken argument is a single allocation
** obtained from sqlite3DbMalloc(). The calling function
** is responsible for making sure the node eventually gets freed.
**
** If dequote is true, then the token (if it exists) is dequoted.
** If dequote is false, no dequoting is performed. The deQuote
** parameter is ignored if pToken is NULL or if the token does not
** appear to be quoted. If the quotes were of the form "..." (double-quotes)
** then the EP_DblQuoted flag is set on the expression node.
**
** Special case: If op==TK_INTEGER and pToken points to a string that
** can be translated into a 32-bit integer, then the token is not
** stored in u.zToken. Instead, the integer values is written
** into u.iValue and the EP_IntValue flag is set. No extra storage
** is allocated to hold the integer text and the dequote flag is ignored.
*/
Expr *sqlite3ExprAlloc(
sqlite3 *db, /* Handle for sqlite3DbMallocRawNN() */
int op, /* Expression opcode */
const Token *pToken, /* Token argument. Might be NULL */
int dequote /* True to dequote */
){
Expr *pNew;
int nExtra = 0;
int iValue = 0;
assert( db!=0 );
if( pToken ){
if( op!=TK_INTEGER || pToken->z==0
|| sqlite3GetInt32(pToken->z, &iValue)==0 ){
nExtra = pToken->n+1;
assert( iValue>=0 );
}
}
pNew = sqlite3DbMallocRawNN(db, sizeof(Expr)+nExtra);
if( pNew ){
memset(pNew, 0, sizeof(Expr));
pNew->op = (u8)op;
pNew->iAgg = -1;
if( pToken ){
if( nExtra==0 ){
pNew->flags |= EP_IntValue|EP_Leaf|(iValue?EP_IsTrue:EP_IsFalse);
pNew->u.iValue = iValue;
}else{
pNew->u.zToken = (char*)&pNew[1];
assert( pToken->z!=0 || pToken->n==0 );
if( pToken->n ) memcpy(pNew->u.zToken, pToken->z, pToken->n);
pNew->u.zToken[pToken->n] = 0;
if( dequote && sqlite3Isquote(pNew->u.zToken[0]) ){
sqlite3DequoteExpr(pNew);
}
}
}
#if SQLITE_MAX_EXPR_DEPTH>0
pNew->nHeight = 1;
#endif
}
return pNew;
}
/*
** Allocate a new expression node from a zero-terminated token that has
** already been dequoted.
*/
Expr *sqlite3Expr(
sqlite3 *db, /* Handle for sqlite3DbMallocZero() (may be null) */
int op, /* Expression opcode */
const char *zToken /* Token argument. Might be NULL */
){
Token x;
x.z = zToken;
x.n = sqlite3Strlen30(zToken);
return sqlite3ExprAlloc(db, op, &x, 0);
}
/*
** Attach subtrees pLeft and pRight to the Expr node pRoot.
**
** If pRoot==NULL that means that a memory allocation error has occurred.
** In that case, delete the subtrees pLeft and pRight.
*/
void sqlite3ExprAttachSubtrees(
sqlite3 *db,
Expr *pRoot,
Expr *pLeft,
Expr *pRight
){
if( pRoot==0 ){
assert( db->mallocFailed );
sqlite3ExprDelete(db, pLeft);
sqlite3ExprDelete(db, pRight);
}else{
if( pRight ){
pRoot->pRight = pRight;
pRoot->flags |= EP_Propagate & pRight->flags;
}
if( pLeft ){
pRoot->pLeft = pLeft;
pRoot->flags |= EP_Propagate & pLeft->flags;
}
exprSetHeight(pRoot);
}
}
/*
** Allocate an Expr node which joins as many as two subtrees.
**
** One or both of the subtrees can be NULL. Return a pointer to the new
** Expr node. Or, if an OOM error occurs, set pParse->db->mallocFailed,
** free the subtrees and return NULL.
*/
Expr *sqlite3PExpr(
Parse *pParse, /* Parsing context */
int op, /* Expression opcode */
Expr *pLeft, /* Left operand */
Expr *pRight /* Right operand */
){
Expr *p;
p = sqlite3DbMallocRawNN(pParse->db, sizeof(Expr));
if( p ){
memset(p, 0, sizeof(Expr));
p->op = op & 0xff;
p->iAgg = -1;
sqlite3ExprAttachSubtrees(pParse->db, p, pLeft, pRight);
sqlite3ExprCheckHeight(pParse, p->nHeight);
}else{
sqlite3ExprDelete(pParse->db, pLeft);
sqlite3ExprDelete(pParse->db, pRight);
}
return p;
}
/*
** Add pSelect to the Expr.x.pSelect field. Or, if pExpr is NULL (due
** do a memory allocation failure) then delete the pSelect object.
*/
void sqlite3PExprAddSelect(Parse *pParse, Expr *pExpr, Select *pSelect){
if( pExpr ){
pExpr->x.pSelect = pSelect;
ExprSetProperty(pExpr, EP_xIsSelect|EP_Subquery);
sqlite3ExprSetHeightAndFlags(pParse, pExpr);
}else{
assert( pParse->db->mallocFailed );
sqlite3SelectDelete(pParse->db, pSelect);
}
}
/*
** Join two expressions using an AND operator. If either expression is
** NULL, then just return the other expression.
**
** If one side or the other of the AND is known to be false, then instead
** of returning an AND expression, just return a constant expression with
** a value of false.
*/
Expr *sqlite3ExprAnd(Parse *pParse, Expr *pLeft, Expr *pRight){
sqlite3 *db = pParse->db;
if( pLeft==0 ){
return pRight;
}else if( pRight==0 ){
return pLeft;
}else if( ExprAlwaysFalse(pLeft) || ExprAlwaysFalse(pRight) ){
sqlite3ExprUnmapAndDelete(pParse, pLeft);
sqlite3ExprUnmapAndDelete(pParse, pRight);
return sqlite3Expr(db, TK_INTEGER, "0");
}else{
return sqlite3PExpr(pParse, TK_AND, pLeft, pRight);
}
}
/*
** Construct a new expression node for a function with multiple
** arguments.
*/
Expr *sqlite3ExprFunction(
Parse *pParse, /* Parsing context */
ExprList *pList, /* Argument list */
Token *pToken, /* Name of the function */
int eDistinct /* SF_Distinct or SF_ALL or 0 */
){
Expr *pNew;
sqlite3 *db = pParse->db;
assert( pToken );
pNew = sqlite3ExprAlloc(db, TK_FUNCTION, pToken, 1);
if( pNew==0 ){
sqlite3ExprListDelete(db, pList); /* Avoid memory leak when malloc fails */
return 0;
}
if( pList && pList->nExpr > pParse->db->aLimit[SQLITE_LIMIT_FUNCTION_ARG] ){
sqlite3ErrorMsg(pParse, "too many arguments on function %T", pToken);
}
pNew->x.pList = pList;
ExprSetProperty(pNew, EP_HasFunc);
assert( !ExprHasProperty(pNew, EP_xIsSelect) );
sqlite3ExprSetHeightAndFlags(pParse, pNew);
if( eDistinct==SF_Distinct ) ExprSetProperty(pNew, EP_Distinct);
return pNew;
}
/*
** Assign a variable number to an expression that encodes a wildcard
** in the original SQL statement.
**
** Wildcards consisting of a single "?" are assigned the next sequential
** variable number.
**
** Wildcards of the form "?nnn" are assigned the number "nnn". We make
** sure "nnn" is not too big to avoid a denial of service attack when
** the SQL statement comes from an external source.
**
** Wildcards of the form ":aaa", "@aaa", or "$aaa" are assigned the same number
** as the previous instance of the same wildcard. Or if this is the first
** instance of the wildcard, the next sequential variable number is
** assigned.
*/
void sqlite3ExprAssignVarNumber(Parse *pParse, Expr *pExpr, u32 n){
sqlite3 *db = pParse->db;
const char *z;
ynVar x;
if( pExpr==0 ) return;
assert( !ExprHasProperty(pExpr, EP_IntValue|EP_Reduced|EP_TokenOnly) );
z = pExpr->u.zToken;
assert( z!=0 );
assert( z[0]!=0 );
assert( n==(u32)sqlite3Strlen30(z) );
if( z[1]==0 ){
/* Wildcard of the form "?". Assign the next variable number */
assert( z[0]=='?' );
x = (ynVar)(++pParse->nVar);
}else{
int doAdd = 0;
if( z[0]=='?' ){
/* Wildcard of the form "?nnn". Convert "nnn" to an integer and
** use it as the variable number */
i64 i;
int bOk;
if( n==2 ){ /*OPTIMIZATION-IF-TRUE*/
i = z[1]-'0'; /* The common case of ?N for a single digit N */
bOk = 1;
}else{
bOk = 0==sqlite3Atoi64(&z[1], &i, n-1, SQLITE_UTF8);
}
testcase( i==0 );
testcase( i==1 );
testcase( i==db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER]-1 );
testcase( i==db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER] );
if( bOk==0 || i<1 || i>db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER] ){
sqlite3ErrorMsg(pParse, "variable number must be between ?1 and ?%d",
db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER]);
return;
}
x = (ynVar)i;
if( x>pParse->nVar ){
pParse->nVar = (int)x;
doAdd = 1;
}else if( sqlite3VListNumToName(pParse->pVList, x)==0 ){
doAdd = 1;
}
}else{
/* Wildcards like ":aaa", "$aaa" or "@aaa". Reuse the same variable
** number as the prior appearance of the same name, or if the name
** has never appeared before, reuse the same variable number
*/
x = (ynVar)sqlite3VListNameToNum(pParse->pVList, z, n);
if( x==0 ){
x = (ynVar)(++pParse->nVar);
doAdd = 1;
}
}
if( doAdd ){
pParse->pVList = sqlite3VListAdd(db, pParse->pVList, z, n, x);
}
}
pExpr->iColumn = x;
if( x>db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER] ){
sqlite3ErrorMsg(pParse, "too many SQL variables");
}
}
/*
** Recursively delete an expression tree.
*/
static SQLITE_NOINLINE void sqlite3ExprDeleteNN(sqlite3 *db, Expr *p){
assert( p!=0 );
/* Sanity check: Assert that the IntValue is non-negative if it exists */
assert( !ExprHasProperty(p, EP_IntValue) || p->u.iValue>=0 );
assert( !ExprHasProperty(p, EP_WinFunc) || p->y.pWin!=0 || db->mallocFailed );
assert( p->op!=TK_FUNCTION || ExprHasProperty(p, EP_TokenOnly|EP_Reduced)
|| p->y.pWin==0 || ExprHasProperty(p, EP_WinFunc) );
#ifdef SQLITE_DEBUG
if( ExprHasProperty(p, EP_Leaf) && !ExprHasProperty(p, EP_TokenOnly) ){
assert( p->pLeft==0 );
assert( p->pRight==0 );
assert( p->x.pSelect==0 );
}
#endif
if( !ExprHasProperty(p, (EP_TokenOnly|EP_Leaf)) ){
/* The Expr.x union is never used at the same time as Expr.pRight */
assert( p->x.pList==0 || p->pRight==0 );
if( p->pLeft && p->op!=TK_SELECT_COLUMN ) sqlite3ExprDeleteNN(db, p->pLeft);
if( p->pRight ){
assert( !ExprHasProperty(p, EP_WinFunc) );
sqlite3ExprDeleteNN(db, p->pRight);
}else if( ExprHasProperty(p, EP_xIsSelect) ){
assert( !ExprHasProperty(p, EP_WinFunc) );
sqlite3SelectDelete(db, p->x.pSelect);
}else{
sqlite3ExprListDelete(db, p->x.pList);
#ifndef SQLITE_OMIT_WINDOWFUNC
if( ExprHasProperty(p, EP_WinFunc) ){
sqlite3WindowDelete(db, p->y.pWin);
}
#endif
}
}
if( ExprHasProperty(p, EP_MemToken) ) sqlite3DbFree(db, p->u.zToken);
if( !ExprHasProperty(p, EP_Static) ){
sqlite3DbFreeNN(db, p);
}
}
void sqlite3ExprDelete(sqlite3 *db, Expr *p){
if( p ) sqlite3ExprDeleteNN(db, p);
}
/* Invoke sqlite3RenameExprUnmap() and sqlite3ExprDelete() on the
** expression.
*/
void sqlite3ExprUnmapAndDelete(Parse *pParse, Expr *p){
if( p ){
if( IN_RENAME_OBJECT ){
sqlite3RenameExprUnmap(pParse, p);
}
sqlite3ExprDeleteNN(pParse->db, p);
}
}
/*
** Return the number of bytes allocated for the expression structure
** passed as the first argument. This is always one of EXPR_FULLSIZE,
** EXPR_REDUCEDSIZE or EXPR_TOKENONLYSIZE.
*/
static int exprStructSize(Expr *p){
if( ExprHasProperty(p, EP_TokenOnly) ) return EXPR_TOKENONLYSIZE;
if( ExprHasProperty(p, EP_Reduced) ) return EXPR_REDUCEDSIZE;
return EXPR_FULLSIZE;
}
/*
** The dupedExpr*Size() routines each return the number of bytes required
** to store a copy of an expression or expression tree. They differ in
** how much of the tree is measured.
**
** dupedExprStructSize() Size of only the Expr structure
** dupedExprNodeSize() Size of Expr + space for token
** dupedExprSize() Expr + token + subtree components
**
***************************************************************************
**
** The dupedExprStructSize() function returns two values OR-ed together:
** (1) the space required for a copy of the Expr structure only and
** (2) the EP_xxx flags that indicate what the structure size should be.
** The return values is always one of:
**
** EXPR_FULLSIZE
** EXPR_REDUCEDSIZE | EP_Reduced
** EXPR_TOKENONLYSIZE | EP_TokenOnly
**
** The size of the structure can be found by masking the return value
** of this routine with 0xfff. The flags can be found by masking the
** return value with EP_Reduced|EP_TokenOnly.
**
** Note that with flags==EXPRDUP_REDUCE, this routines works on full-size
** (unreduced) Expr objects as they or originally constructed by the parser.
** During expression analysis, extra information is computed and moved into
** later parts of the Expr object and that extra information might get chopped
** off if the expression is reduced. Note also that it does not work to
** make an EXPRDUP_REDUCE copy of a reduced expression. It is only legal
** to reduce a pristine expression tree from the parser. The implementation
** of dupedExprStructSize() contain multiple assert() statements that attempt
** to enforce this constraint.
*/
static int dupedExprStructSize(Expr *p, int flags){
int nSize;
assert( flags==EXPRDUP_REDUCE || flags==0 ); /* Only one flag value allowed */
assert( EXPR_FULLSIZE<=0xfff );
assert( (0xfff & (EP_Reduced|EP_TokenOnly))==0 );
if( 0==flags || p->op==TK_SELECT_COLUMN
#ifndef SQLITE_OMIT_WINDOWFUNC
|| ExprHasProperty(p, EP_WinFunc)
#endif
){
nSize = EXPR_FULLSIZE;
}else{
assert( !ExprHasProperty(p, EP_TokenOnly|EP_Reduced) );
assert( !ExprHasProperty(p, EP_FromJoin) );
assert( !ExprHasProperty(p, EP_MemToken) );
assert( !ExprHasProperty(p, EP_NoReduce) );
if( p->pLeft || p->x.pList ){
nSize = EXPR_REDUCEDSIZE | EP_Reduced;
}else{
assert( p->pRight==0 );
nSize = EXPR_TOKENONLYSIZE | EP_TokenOnly;
}
}
return nSize;
}
/*
** This function returns the space in bytes required to store the copy
** of the Expr structure and a copy of the Expr.u.zToken string (if that
** string is defined.)
*/
static int dupedExprNodeSize(Expr *p, int flags){
int nByte = dupedExprStructSize(p, flags) & 0xfff;
if( !ExprHasProperty(p, EP_IntValue) && p->u.zToken ){
nByte += sqlite3Strlen30NN(p->u.zToken)+1;
}
return ROUND8(nByte);
}
/*
** Return the number of bytes required to create a duplicate of the
** expression passed as the first argument. The second argument is a
** mask containing EXPRDUP_XXX flags.
**
** The value returned includes space to create a copy of the Expr struct
** itself and the buffer referred to by Expr.u.zToken, if any.
**
** If the EXPRDUP_REDUCE flag is set, then the return value includes
** space to duplicate all Expr nodes in the tree formed by Expr.pLeft
** and Expr.pRight variables (but not for any structures pointed to or
** descended from the Expr.x.pList or Expr.x.pSelect variables).
*/
static int dupedExprSize(Expr *p, int flags){
int nByte = 0;
if( p ){
nByte = dupedExprNodeSize(p, flags);
if( flags&EXPRDUP_REDUCE ){
nByte += dupedExprSize(p->pLeft, flags) + dupedExprSize(p->pRight, flags);
}
}
return nByte;
}
/*
** This function is similar to sqlite3ExprDup(), except that if pzBuffer
** is not NULL then *pzBuffer is assumed to point to a buffer large enough
** to store the copy of expression p, the copies of p->u.zToken
** (if applicable), and the copies of the p->pLeft and p->pRight expressions,
** if any. Before returning, *pzBuffer is set to the first byte past the
** portion of the buffer copied into by this function.
*/
static Expr *exprDup(sqlite3 *db, Expr *p, int dupFlags, u8 **pzBuffer){
Expr *pNew; /* Value to return */
u8 *zAlloc; /* Memory space from which to build Expr object */
u32 staticFlag; /* EP_Static if space not obtained from malloc */
assert( db!=0 );
assert( p );
assert( dupFlags==0 || dupFlags==EXPRDUP_REDUCE );
assert( pzBuffer==0 || dupFlags==EXPRDUP_REDUCE );
/* Figure out where to write the new Expr structure. */
if( pzBuffer ){
zAlloc = *pzBuffer;
staticFlag = EP_Static;
}else{
zAlloc = sqlite3DbMallocRawNN(db, dupedExprSize(p, dupFlags));
staticFlag = 0;
}
pNew = (Expr *)zAlloc;
if( pNew ){
/* Set nNewSize to the size allocated for the structure pointed to
** by pNew. This is either EXPR_FULLSIZE, EXPR_REDUCEDSIZE or
** EXPR_TOKENONLYSIZE. nToken is set to the number of bytes consumed
** by the copy of the p->u.zToken string (if any).
*/
const unsigned nStructSize = dupedExprStructSize(p, dupFlags);
const int nNewSize = nStructSize & 0xfff;
int nToken;
if( !ExprHasProperty(p, EP_IntValue) && p->u.zToken ){
nToken = sqlite3Strlen30(p->u.zToken) + 1;
}else{
nToken = 0;
}
if( dupFlags ){
assert( ExprHasProperty(p, EP_Reduced)==0 );
memcpy(zAlloc, p, nNewSize);
}else{
u32 nSize = (u32)exprStructSize(p);
memcpy(zAlloc, p, nSize);
if( nSize<EXPR_FULLSIZE ){
memset(&zAlloc[nSize], 0, EXPR_FULLSIZE-nSize);
}
}
/* Set the EP_Reduced, EP_TokenOnly, and EP_Static flags appropriately. */
pNew->flags &= ~(EP_Reduced|EP_TokenOnly|EP_Static|EP_MemToken);
pNew->flags |= nStructSize & (EP_Reduced|EP_TokenOnly);
pNew->flags |= staticFlag;
/* Copy the p->u.zToken string, if any. */
if( nToken ){
char *zToken = pNew->u.zToken = (char*)&zAlloc[nNewSize];
memcpy(zToken, p->u.zToken, nToken);
}
if( 0==((p->flags|pNew->flags) & (EP_TokenOnly|EP_Leaf)) ){
/* Fill in the pNew->x.pSelect or pNew->x.pList member. */
if( ExprHasProperty(p, EP_xIsSelect) ){
pNew->x.pSelect = sqlite3SelectDup(db, p->x.pSelect, dupFlags);
}else{
pNew->x.pList = sqlite3ExprListDup(db, p->x.pList, dupFlags);
}
}
/* Fill in pNew->pLeft and pNew->pRight. */
if( ExprHasProperty(pNew, EP_Reduced|EP_TokenOnly|EP_WinFunc) ){
zAlloc += dupedExprNodeSize(p, dupFlags);
if( !ExprHasProperty(pNew, EP_TokenOnly|EP_Leaf) ){
pNew->pLeft = p->pLeft ?
exprDup(db, p->pLeft, EXPRDUP_REDUCE, &zAlloc) : 0;
pNew->pRight = p->pRight ?
exprDup(db, p->pRight, EXPRDUP_REDUCE, &zAlloc) : 0;
}
#ifndef SQLITE_OMIT_WINDOWFUNC
if( ExprHasProperty(p, EP_WinFunc) ){
pNew->y.pWin = sqlite3WindowDup(db, pNew, p->y.pWin);
assert( ExprHasProperty(pNew, EP_WinFunc) );
}
#endif /* SQLITE_OMIT_WINDOWFUNC */
if( pzBuffer ){
*pzBuffer = zAlloc;
}
}else{
if( !ExprHasProperty(p, EP_TokenOnly|EP_Leaf) ){
if( pNew->op==TK_SELECT_COLUMN ){
pNew->pLeft = p->pLeft;
assert( p->iColumn==0 || p->pRight==0 );
assert( p->pRight==0 || p->pRight==p->pLeft );
}else{
pNew->pLeft = sqlite3ExprDup(db, p->pLeft, 0);
}
pNew->pRight = sqlite3ExprDup(db, p->pRight, 0);
}
}
}
return pNew;
}
/*
** Create and return a deep copy of the object passed as the second
** argument. If an OOM condition is encountered, NULL is returned
** and the db->mallocFailed flag set.
*/
#ifndef SQLITE_OMIT_CTE
static With *withDup(sqlite3 *db, With *p){
With *pRet = 0;
if( p ){
sqlite3_int64 nByte = sizeof(*p) + sizeof(p->a[0]) * (p->nCte-1);
pRet = sqlite3DbMallocZero(db, nByte);
if( pRet ){
int i;
pRet->nCte = p->nCte;
for(i=0; i<p->nCte; i++){
pRet->a[i].pSelect = sqlite3SelectDup(db, p->a[i].pSelect, 0);
pRet->a[i].pCols = sqlite3ExprListDup(db, p->a[i].pCols, 0);
pRet->a[i].zName = sqlite3DbStrDup(db, p->a[i].zName);
}
}
}
return pRet;
}
#else
# define withDup(x,y) 0
#endif
#ifndef SQLITE_OMIT_WINDOWFUNC
/*
** The gatherSelectWindows() procedure and its helper routine
** gatherSelectWindowsCallback() are used to scan all the expressions
** an a newly duplicated SELECT statement and gather all of the Window
** objects found there, assembling them onto the linked list at Select->pWin.
*/
static int gatherSelectWindowsCallback(Walker *pWalker, Expr *pExpr){
if( pExpr->op==TK_FUNCTION && ExprHasProperty(pExpr, EP_WinFunc) ){
Select *pSelect = pWalker->u.pSelect;
Window *pWin = pExpr->y.pWin;
assert( pWin );
assert( IsWindowFunc(pExpr) );
assert( pWin->ppThis==0 );
sqlite3WindowLink(pSelect, pWin);
}
return WRC_Continue;
}
static int gatherSelectWindowsSelectCallback(Walker *pWalker, Select *p){
return p==pWalker->u.pSelect ? WRC_Continue : WRC_Prune;
}
static void gatherSelectWindows(Select *p){
Walker w;
w.xExprCallback = gatherSelectWindowsCallback;
w.xSelectCallback = gatherSelectWindowsSelectCallback;
w.xSelectCallback2 = 0;
w.pParse = 0;
w.u.pSelect = p;
sqlite3WalkSelect(&w, p);
}
#endif
/*
** The following group of routines make deep copies of expressions,
** expression lists, ID lists, and select statements. The copies can
** be deleted (by being passed to their respective ...Delete() routines)
** without effecting the originals.
**
** The expression list, ID, and source lists return by sqlite3ExprListDup(),
** sqlite3IdListDup(), and sqlite3SrcListDup() can not be further expanded
** by subsequent calls to sqlite*ListAppend() routines.
**
** Any tables that the SrcList might point to are not duplicated.
**
** The flags parameter contains a combination of the EXPRDUP_XXX flags.
** If the EXPRDUP_REDUCE flag is set, then the structure returned is a
** truncated version of the usual Expr structure that will be stored as
** part of the in-memory representation of the database schema.
*/
Expr *sqlite3ExprDup(sqlite3 *db, Expr *p, int flags){
assert( flags==0 || flags==EXPRDUP_REDUCE );
return p ? exprDup(db, p, flags, 0) : 0;
}
ExprList *sqlite3ExprListDup(sqlite3 *db, ExprList *p, int flags){
ExprList *pNew;
struct ExprList_item *pItem, *pOldItem;
int i;
Expr *pPriorSelectCol = 0;
assert( db!=0 );
if( p==0 ) return 0;
pNew = sqlite3DbMallocRawNN(db, sqlite3DbMallocSize(db, p));
if( pNew==0 ) return 0;
pNew->nExpr = p->nExpr;
pItem = pNew->a;
pOldItem = p->a;
for(i=0; i<p->nExpr; i++, pItem++, pOldItem++){
Expr *pOldExpr = pOldItem->pExpr;
Expr *pNewExpr;
pItem->pExpr = sqlite3ExprDup(db, pOldExpr, flags);
if( pOldExpr
&& pOldExpr->op==TK_SELECT_COLUMN
&& (pNewExpr = pItem->pExpr)!=0
){
assert( pNewExpr->iColumn==0 || i>0 );
if( pNewExpr->iColumn==0 ){
assert( pOldExpr->pLeft==pOldExpr->pRight );
pPriorSelectCol = pNewExpr->pLeft = pNewExpr->pRight;
}else{
assert( i>0 );
assert( pItem[-1].pExpr!=0 );
assert( pNewExpr->iColumn==pItem[-1].pExpr->iColumn+1 );
assert( pPriorSelectCol==pItem[-1].pExpr->pLeft );
pNewExpr->pLeft = pPriorSelectCol;
}
}
pItem->zName = sqlite3DbStrDup(db, pOldItem->zName);
pItem->zSpan = sqlite3DbStrDup(db, pOldItem->zSpan);
pItem->sortFlags = pOldItem->sortFlags;
pItem->done = 0;
pItem->bNulls = pOldItem->bNulls;
pItem->bSpanIsTab = pOldItem->bSpanIsTab;
pItem->bSorterRef = pOldItem->bSorterRef;
pItem->u = pOldItem->u;
}
return pNew;
}
/*
** If cursors, triggers, views and subqueries are all omitted from
** the build, then none of the following routines, except for
** sqlite3SelectDup(), can be called. sqlite3SelectDup() is sometimes
** called with a NULL argument.
*/
#if !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_TRIGGER) \
|| !defined(SQLITE_OMIT_SUBQUERY)
SrcList *sqlite3SrcListDup(sqlite3 *db, SrcList *p, int flags){
SrcList *pNew;
int i;
int nByte;
assert( db!=0 );
if( p==0 ) return 0;
nByte = sizeof(*p) + (p->nSrc>0 ? sizeof(p->a[0]) * (p->nSrc-1) : 0);
pNew = sqlite3DbMallocRawNN(db, nByte );
if( pNew==0 ) return 0;
pNew->nSrc = pNew->nAlloc = p->nSrc;
for(i=0; i<p->nSrc; i++){
struct SrcList_item *pNewItem = &pNew->a[i];
struct SrcList_item *pOldItem = &p->a[i];
Table *pTab;
pNewItem->pSchema = pOldItem->pSchema;
pNewItem->zDatabase = sqlite3DbStrDup(db, pOldItem->zDatabase);
pNewItem->zName = sqlite3DbStrDup(db, pOldItem->zName);
pNewItem->zAlias = sqlite3DbStrDup(db, pOldItem->zAlias);
pNewItem->fg = pOldItem->fg;
pNewItem->iCursor = pOldItem->iCursor;
pNewItem->addrFillSub = pOldItem->addrFillSub;
pNewItem->regReturn = pOldItem->regReturn;
if( pNewItem->fg.isIndexedBy ){
pNewItem->u1.zIndexedBy = sqlite3DbStrDup(db, pOldItem->u1.zIndexedBy);
}
pNewItem->pIBIndex = pOldItem->pIBIndex;
if( pNewItem->fg.isTabFunc ){
pNewItem->u1.pFuncArg =
sqlite3ExprListDup(db, pOldItem->u1.pFuncArg, flags);
}
pTab = pNewItem->pTab = pOldItem->pTab;
if( pTab ){
pTab->nTabRef++;
}
pNewItem->pSelect = sqlite3SelectDup(db, pOldItem->pSelect, flags);
pNewItem->pOn = sqlite3ExprDup(db, pOldItem->pOn, flags);
pNewItem->pUsing = sqlite3IdListDup(db, pOldItem->pUsing);
pNewItem->colUsed = pOldItem->colUsed;
}
return pNew;
}
IdList *sqlite3IdListDup(sqlite3 *db, IdList *p){
IdList *pNew;
int i;
assert( db!=0 );
if( p==0 ) return 0;
pNew = sqlite3DbMallocRawNN(db, sizeof(*pNew) );
if( pNew==0 ) return 0;
pNew->nId = p->nId;
pNew->a = sqlite3DbMallocRawNN(db, p->nId*sizeof(p->a[0]) );
if( pNew->a==0 ){
sqlite3DbFreeNN(db, pNew);
return 0;
}
/* Note that because the size of the allocation for p->a[] is not
** necessarily a power of two, sqlite3IdListAppend() may not be called
** on the duplicate created by this function. */
for(i=0; i<p->nId; i++){
struct IdList_item *pNewItem = &pNew->a[i];
struct IdList_item *pOldItem = &p->a[i];
pNewItem->zName = sqlite3DbStrDup(db, pOldItem->zName);
pNewItem->idx = pOldItem->idx;
}
return pNew;
}
Select *sqlite3SelectDup(sqlite3 *db, Select *pDup, int flags){
Select *pRet = 0;
Select *pNext = 0;
Select **pp = &pRet;
Select *p;
assert( db!=0 );
for(p=pDup; p; p=p->pPrior){
Select *pNew = sqlite3DbMallocRawNN(db, sizeof(*p) );
if( pNew==0 ) break;
pNew->pEList = sqlite3ExprListDup(db, p->pEList, flags);
pNew->pSrc = sqlite3SrcListDup(db, p->pSrc, flags);
pNew->pWhere = sqlite3ExprDup(db, p->pWhere, flags);
pNew->pGroupBy = sqlite3ExprListDup(db, p->pGroupBy, flags);
pNew->pHaving = sqlite3ExprDup(db, p->pHaving, flags);
pNew->pOrderBy = sqlite3ExprListDup(db, p->pOrderBy, flags);
pNew->op = p->op;
pNew->pNext = pNext;
pNew->pPrior = 0;
pNew->pLimit = sqlite3ExprDup(db, p->pLimit, flags);
pNew->iLimit = 0;
pNew->iOffset = 0;
pNew->selFlags = p->selFlags & ~SF_UsesEphemeral;
pNew->addrOpenEphm[0] = -1;
pNew->addrOpenEphm[1] = -1;
pNew->nSelectRow = p->nSelectRow;
pNew->pWith = withDup(db, p->pWith);
#ifndef SQLITE_OMIT_WINDOWFUNC
pNew->pWin = 0;
pNew->pWinDefn = sqlite3WindowListDup(db, p->pWinDefn);
if( p->pWin && db->mallocFailed==0 ) gatherSelectWindows(pNew);
#endif
pNew->selId = p->selId;
*pp = pNew;
pp = &pNew->pPrior;
pNext = pNew;
}
return pRet;
}
#else
Select *sqlite3SelectDup(sqlite3 *db, Select *p, int flags){
assert( p==0 );
return 0;
}
#endif
/*
** Add a new element to the end of an expression list. If pList is
** initially NULL, then create a new expression list.
**
** The pList argument must be either NULL or a pointer to an ExprList
** obtained from a prior call to sqlite3ExprListAppend(). This routine
** may not be used with an ExprList obtained from sqlite3ExprListDup().
** Reason: This routine assumes that the number of slots in pList->a[]
** is a power of two. That is true for sqlite3ExprListAppend() returns
** but is not necessarily true from the return value of sqlite3ExprListDup().
**
** If a memory allocation error occurs, the entire list is freed and
** NULL is returned. If non-NULL is returned, then it is guaranteed
** that the new entry was successfully appended.
*/
ExprList *sqlite3ExprListAppend(
Parse *pParse, /* Parsing context */
ExprList *pList, /* List to which to append. Might be NULL */
Expr *pExpr /* Expression to be appended. Might be NULL */
){
struct ExprList_item *pItem;
sqlite3 *db = pParse->db;
assert( db!=0 );
if( pList==0 ){
pList = sqlite3DbMallocRawNN(db, sizeof(ExprList) );
if( pList==0 ){
goto no_mem;
}
pList->nExpr = 0;
}else if( (pList->nExpr & (pList->nExpr-1))==0 ){
ExprList *pNew;
pNew = sqlite3DbRealloc(db, pList,
sizeof(*pList)+(2*(sqlite3_int64)pList->nExpr-1)*sizeof(pList->a[0]));
if( pNew==0 ){
goto no_mem;
}
pList = pNew;
}
pItem = &pList->a[pList->nExpr++];
assert( offsetof(struct ExprList_item,zName)==sizeof(pItem->pExpr) );
assert( offsetof(struct ExprList_item,pExpr)==0 );
memset(&pItem->zName,0,sizeof(*pItem)-offsetof(struct ExprList_item,zName));
pItem->pExpr = pExpr;
return pList;
no_mem:
/* Avoid leaking memory if malloc has failed. */
sqlite3ExprDelete(db, pExpr);
sqlite3ExprListDelete(db, pList);
return 0;
}
/*
** pColumns and pExpr form a vector assignment which is part of the SET
** clause of an UPDATE statement. Like this:
**
** (a,b,c) = (expr1,expr2,expr3)
** Or: (a,b,c) = (SELECT x,y,z FROM ....)
**
** For each term of the vector assignment, append new entries to the
** expression list pList. In the case of a subquery on the RHS, append
** TK_SELECT_COLUMN expressions.
*/
ExprList *sqlite3ExprListAppendVector(
Parse *pParse, /* Parsing context */
ExprList *pList, /* List to which to append. Might be NULL */
IdList *pColumns, /* List of names of LHS of the assignment */
Expr *pExpr /* Vector expression to be appended. Might be NULL */
){
sqlite3 *db = pParse->db;
int n;
int i;
int iFirst = pList ? pList->nExpr : 0;
/* pColumns can only be NULL due to an OOM but an OOM will cause an
** exit prior to this routine being invoked */
if( NEVER(pColumns==0) ) goto vector_append_error;
if( pExpr==0 ) goto vector_append_error;
/* If the RHS is a vector, then we can immediately check to see that
** the size of the RHS and LHS match. But if the RHS is a SELECT,
** wildcards ("*") in the result set of the SELECT must be expanded before
** we can do the size check, so defer the size check until code generation.
*/
if( pExpr->op!=TK_SELECT && pColumns->nId!=(n=sqlite3ExprVectorSize(pExpr)) ){
sqlite3ErrorMsg(pParse, "%d columns assigned %d values",
pColumns->nId, n);
goto vector_append_error;
}
for(i=0; i<pColumns->nId; i++){
Expr *pSubExpr = sqlite3ExprForVectorField(pParse, pExpr, i);
assert( pSubExpr!=0 || db->mallocFailed );
assert( pSubExpr==0 || pSubExpr->iTable==0 );
if( pSubExpr==0 ) continue;
pSubExpr->iTable = pColumns->nId;
pList = sqlite3ExprListAppend(pParse, pList, pSubExpr);
if( pList ){
assert( pList->nExpr==iFirst+i+1 );
pList->a[pList->nExpr-1].zName = pColumns->a[i].zName;
pColumns->a[i].zName = 0;
}
}
if( !db->mallocFailed && pExpr->op==TK_SELECT && ALWAYS(pList!=0) ){
Expr *pFirst = pList->a[iFirst].pExpr;
assert( pFirst!=0 );
assert( pFirst->op==TK_SELECT_COLUMN );
/* Store the SELECT statement in pRight so it will be deleted when
** sqlite3ExprListDelete() is called */
pFirst->pRight = pExpr;
pExpr = 0;
/* Remember the size of the LHS in iTable so that we can check that
** the RHS and LHS sizes match during code generation. */
pFirst->iTable = pColumns->nId;
}
vector_append_error:
sqlite3ExprUnmapAndDelete(pParse, pExpr);
sqlite3IdListDelete(db, pColumns);
return pList;
}
/*
** Set the sort order for the last element on the given ExprList.
*/
void sqlite3ExprListSetSortOrder(ExprList *p, int iSortOrder, int eNulls){
struct ExprList_item *pItem;
if( p==0 ) return;
assert( p->nExpr>0 );
assert( SQLITE_SO_UNDEFINED<0 && SQLITE_SO_ASC==0 && SQLITE_SO_DESC>0 );
assert( iSortOrder==SQLITE_SO_UNDEFINED
|| iSortOrder==SQLITE_SO_ASC
|| iSortOrder==SQLITE_SO_DESC
);
assert( eNulls==SQLITE_SO_UNDEFINED
|| eNulls==SQLITE_SO_ASC
|| eNulls==SQLITE_SO_DESC
);
pItem = &p->a[p->nExpr-1];
assert( pItem->bNulls==0 );
if( iSortOrder==SQLITE_SO_UNDEFINED ){
iSortOrder = SQLITE_SO_ASC;
}
pItem->sortFlags = (u8)iSortOrder;
if( eNulls!=SQLITE_SO_UNDEFINED ){
pItem->bNulls = 1;
if( iSortOrder!=eNulls ){
pItem->sortFlags |= KEYINFO_ORDER_BIGNULL;
}
}
}
/*
** Set the ExprList.a[].zName element of the most recently added item
** on the expression list.
**
** pList might be NULL following an OOM error. But pName should never be
** NULL. If a memory allocation fails, the pParse->db->mallocFailed flag
** is set.
*/
void sqlite3ExprListSetName(
Parse *pParse, /* Parsing context */
ExprList *pList, /* List to which to add the span. */
Token *pName, /* Name to be added */
int dequote /* True to cause the name to be dequoted */
){
assert( pList!=0 || pParse->db->mallocFailed!=0 );
if( pList ){
struct ExprList_item *pItem;
assert( pList->nExpr>0 );
pItem = &pList->a[pList->nExpr-1];
assert( pItem->zName==0 );
pItem->zName = sqlite3DbStrNDup(pParse->db, pName->z, pName->n);
if( dequote ) sqlite3Dequote(pItem->zName);
if( IN_RENAME_OBJECT ){
sqlite3RenameTokenMap(pParse, (void*)pItem->zName, pName);
}
}
}
/*
** Set the ExprList.a[].zSpan element of the most recently added item
** on the expression list.
**
** pList might be NULL following an OOM error. But pSpan should never be
** NULL. If a memory allocation fails, the pParse->db->mallocFailed flag
** is set.
*/
void sqlite3ExprListSetSpan(
Parse *pParse, /* Parsing context */
ExprList *pList, /* List to which to add the span. */
const char *zStart, /* Start of the span */
const char *zEnd /* End of the span */
){
sqlite3 *db = pParse->db;
assert( pList!=0 || db->mallocFailed!=0 );
if( pList ){
struct ExprList_item *pItem = &pList->a[pList->nExpr-1];
assert( pList->nExpr>0 );
sqlite3DbFree(db, pItem->zSpan);
pItem->zSpan = sqlite3DbSpanDup(db, zStart, zEnd);
}
}
/*
** If the expression list pEList contains more than iLimit elements,
** leave an error message in pParse.
*/
void sqlite3ExprListCheckLength(
Parse *pParse,
ExprList *pEList,
const char *zObject
){
int mx = pParse->db->aLimit[SQLITE_LIMIT_COLUMN];
testcase( pEList && pEList->nExpr==mx );
testcase( pEList && pEList->nExpr==mx+1 );
if( pEList && pEList->nExpr>mx ){
sqlite3ErrorMsg(pParse, "too many columns in %s", zObject);
}
}
/*
** Delete an entire expression list.
*/
static SQLITE_NOINLINE void exprListDeleteNN(sqlite3 *db, ExprList *pList){
int i = pList->nExpr;
struct ExprList_item *pItem = pList->a;
assert( pList->nExpr>0 );
do{
sqlite3ExprDelete(db, pItem->pExpr);
sqlite3DbFree(db, pItem->zName);
sqlite3DbFree(db, pItem->zSpan);
pItem++;
}while( --i>0 );
sqlite3DbFreeNN(db, pList);
}
void sqlite3ExprListDelete(sqlite3 *db, ExprList *pList){
if( pList ) exprListDeleteNN(db, pList);
}
/*
** Return the bitwise-OR of all Expr.flags fields in the given
** ExprList.
*/
u32 sqlite3ExprListFlags(const ExprList *pList){
int i;
u32 m = 0;
assert( pList!=0 );
for(i=0; i<pList->nExpr; i++){
Expr *pExpr = pList->a[i].pExpr;
assert( pExpr!=0 );
m |= pExpr->flags;
}
return m;
}
/*
** This is a SELECT-node callback for the expression walker that
** always "fails". By "fail" in this case, we mean set
** pWalker->eCode to zero and abort.
**
** This callback is used by multiple expression walkers.
*/
int sqlite3SelectWalkFail(Walker *pWalker, Select *NotUsed){
UNUSED_PARAMETER(NotUsed);
pWalker->eCode = 0;
return WRC_Abort;
}
/*
** If the input expression is an ID with the name "true" or "false"
** then convert it into an TK_TRUEFALSE term. Return non-zero if
** the conversion happened, and zero if the expression is unaltered.
*/
int sqlite3ExprIdToTrueFalse(Expr *pExpr){
assert( pExpr->op==TK_ID || pExpr->op==TK_STRING );
if( !ExprHasProperty(pExpr, EP_Quoted)
&& (sqlite3StrICmp(pExpr->u.zToken, "true")==0
|| sqlite3StrICmp(pExpr->u.zToken, "false")==0)
){
pExpr->op = TK_TRUEFALSE;
ExprSetProperty(pExpr, pExpr->u.zToken[4]==0 ? EP_IsTrue : EP_IsFalse);
return 1;
}
return 0;
}
/*
** The argument must be a TK_TRUEFALSE Expr node. Return 1 if it is TRUE
** and 0 if it is FALSE.
*/
int sqlite3ExprTruthValue(const Expr *pExpr){
pExpr = sqlite3ExprSkipCollate((Expr*)pExpr);
assert( pExpr->op==TK_TRUEFALSE );
assert( sqlite3StrICmp(pExpr->u.zToken,"true")==0
|| sqlite3StrICmp(pExpr->u.zToken,"false")==0 );
return pExpr->u.zToken[4]==0;
}
/*
** If pExpr is an AND or OR expression, try to simplify it by eliminating
** terms that are always true or false. Return the simplified expression.
** Or return the original expression if no simplification is possible.
**
** Examples:
**
** (x<10) AND true => (x<10)
** (x<10) AND false => false
** (x<10) AND (y=22 OR false) => (x<10) AND (y=22)
** (x<10) AND (y=22 OR true) => (x<10)
** (y=22) OR true => true
*/
Expr *sqlite3ExprSimplifiedAndOr(Expr *pExpr){
assert( pExpr!=0 );
if( pExpr->op==TK_AND || pExpr->op==TK_OR ){
Expr *pRight = sqlite3ExprSimplifiedAndOr(pExpr->pRight);
Expr *pLeft = sqlite3ExprSimplifiedAndOr(pExpr->pLeft);
if( ExprAlwaysTrue(pLeft) || ExprAlwaysFalse(pRight) ){
pExpr = pExpr->op==TK_AND ? pRight : pLeft;
}else if( ExprAlwaysTrue(pRight) || ExprAlwaysFalse(pLeft) ){
pExpr = pExpr->op==TK_AND ? pLeft : pRight;
}
}
return pExpr;
}
/*
** These routines are Walker callbacks used to check expressions to
** see if they are "constant" for some definition of constant. The
** Walker.eCode value determines the type of "constant" we are looking
** for.
**
** These callback routines are used to implement the following:
**
** sqlite3ExprIsConstant() pWalker->eCode==1
** sqlite3ExprIsConstantNotJoin() pWalker->eCode==2
** sqlite3ExprIsTableConstant() pWalker->eCode==3
** sqlite3ExprIsConstantOrFunction() pWalker->eCode==4 or 5
**
** In all cases, the callbacks set Walker.eCode=0 and abort if the expression
** is found to not be a constant.
**
** The sqlite3ExprIsConstantOrFunction() is used for evaluating expressions
** in a CREATE TABLE statement. The Walker.eCode value is 5 when parsing
** an existing schema and 4 when processing a new statement. A bound
** parameter raises an error for new statements, but is silently converted
** to NULL for existing schemas. This allows sqlite_master tables that
** contain a bound parameter because they were generated by older versions
** of SQLite to be parsed by newer versions of SQLite without raising a
** malformed schema error.
*/
static int exprNodeIsConstant(Walker *pWalker, Expr *pExpr){
/* If pWalker->eCode is 2 then any term of the expression that comes from
** the ON or USING clauses of a left join disqualifies the expression
** from being considered constant. */
if( pWalker->eCode==2 && ExprHasProperty(pExpr, EP_FromJoin) ){
pWalker->eCode = 0;
return WRC_Abort;
}
switch( pExpr->op ){
/* Consider functions to be constant if all their arguments are constant
** and either pWalker->eCode==4 or 5 or the function has the
** SQLITE_FUNC_CONST flag. */
case TK_FUNCTION:
if( pWalker->eCode>=4 || ExprHasProperty(pExpr,EP_ConstFunc) ){
return WRC_Continue;
}else{
pWalker->eCode = 0;
return WRC_Abort;
}
case TK_ID:
/* Convert "true" or "false" in a DEFAULT clause into the
** appropriate TK_TRUEFALSE operator */
if( sqlite3ExprIdToTrueFalse(pExpr) ){
return WRC_Prune;
}
/* Fall thru */
case TK_COLUMN:
case TK_AGG_FUNCTION:
case TK_AGG_COLUMN:
testcase( pExpr->op==TK_ID );
testcase( pExpr->op==TK_COLUMN );
testcase( pExpr->op==TK_AGG_FUNCTION );
testcase( pExpr->op==TK_AGG_COLUMN );
if( ExprHasProperty(pExpr, EP_FixedCol) && pWalker->eCode!=2 ){
return WRC_Continue;
}
if( pWalker->eCode==3 && pExpr->iTable==pWalker->u.iCur ){
return WRC_Continue;
}
/* Fall through */
case TK_IF_NULL_ROW:
case TK_REGISTER:
testcase( pExpr->op==TK_REGISTER );
testcase( pExpr->op==TK_IF_NULL_ROW );
pWalker->eCode = 0;
return WRC_Abort;
case TK_VARIABLE:
if( pWalker->eCode==5 ){
/* Silently convert bound parameters that appear inside of CREATE
** statements into a NULL when parsing the CREATE statement text out
** of the sqlite_master table */
pExpr->op = TK_NULL;
}else if( pWalker->eCode==4 ){
/* A bound parameter in a CREATE statement that originates from
** sqlite3_prepare() causes an error */
pWalker->eCode = 0;
return WRC_Abort;
}
/* Fall through */
default:
testcase( pExpr->op==TK_SELECT ); /* sqlite3SelectWalkFail() disallows */
testcase( pExpr->op==TK_EXISTS ); /* sqlite3SelectWalkFail() disallows */
return WRC_Continue;
}
}
static int exprIsConst(Expr *p, int initFlag, int iCur){
Walker w;
w.eCode = initFlag;
w.xExprCallback = exprNodeIsConstant;
w.xSelectCallback = sqlite3SelectWalkFail;
#ifdef SQLITE_DEBUG
w.xSelectCallback2 = sqlite3SelectWalkAssert2;
#endif
w.u.iCur = iCur;
sqlite3WalkExpr(&w, p);
return w.eCode;
}
/*
** Walk an expression tree. Return non-zero if the expression is constant
** and 0 if it involves variables or function calls.
**
** For the purposes of this function, a double-quoted string (ex: "abc")
** is considered a variable but a single-quoted string (ex: 'abc') is
** a constant.
*/
int sqlite3ExprIsConstant(Expr *p){
return exprIsConst(p, 1, 0);
}
/*
** Walk an expression tree. Return non-zero if
**
** (1) the expression is constant, and
** (2) the expression does originate in the ON or USING clause
** of a LEFT JOIN, and
** (3) the expression does not contain any EP_FixedCol TK_COLUMN
** operands created by the constant propagation optimization.
**
** When this routine returns true, it indicates that the expression
** can be added to the pParse->pConstExpr list and evaluated once when
** the prepared statement starts up. See sqlite3ExprCodeAtInit().
*/
int sqlite3ExprIsConstantNotJoin(Expr *p){
return exprIsConst(p, 2, 0);
}
/*
** Walk an expression tree. Return non-zero if the expression is constant
** for any single row of the table with cursor iCur. In other words, the
** expression must not refer to any non-deterministic function nor any
** table other than iCur.
*/
int sqlite3ExprIsTableConstant(Expr *p, int iCur){
return exprIsConst(p, 3, iCur);
}
/*
** sqlite3WalkExpr() callback used by sqlite3ExprIsConstantOrGroupBy().
*/
static int exprNodeIsConstantOrGroupBy(Walker *pWalker, Expr *pExpr){
ExprList *pGroupBy = pWalker->u.pGroupBy;
int i;
/* Check if pExpr is identical to any GROUP BY term. If so, consider
** it constant. */
for(i=0; i<pGroupBy->nExpr; i++){
Expr *p = pGroupBy->a[i].pExpr;
if( sqlite3ExprCompare(0, pExpr, p, -1)<2 ){
CollSeq *pColl = sqlite3ExprNNCollSeq(pWalker->pParse, p);
if( sqlite3IsBinary(pColl) ){
return WRC_Prune;
}
}
}
/* Check if pExpr is a sub-select. If so, consider it variable. */
if( ExprHasProperty(pExpr, EP_xIsSelect) ){
pWalker->eCode = 0;
return WRC_Abort;
}
return exprNodeIsConstant(pWalker, pExpr);
}
/*
** Walk the expression tree passed as the first argument. Return non-zero
** if the expression consists entirely of constants or copies of terms
** in pGroupBy that sort with the BINARY collation sequence.
**
** This routine is used to determine if a term of the HAVING clause can
** be promoted into the WHERE clause. In order for such a promotion to work,
** the value of the HAVING clause term must be the same for all members of
** a "group". The requirement that the GROUP BY term must be BINARY
** assumes that no other collating sequence will have a finer-grained
** grouping than binary. In other words (A=B COLLATE binary) implies
** A=B in every other collating sequence. The requirement that the
** GROUP BY be BINARY is stricter than necessary. It would also work
** to promote HAVING clauses that use the same alternative collating
** sequence as the GROUP BY term, but that is much harder to check,
** alternative collating sequences are uncommon, and this is only an
** optimization, so we take the easy way out and simply require the
** GROUP BY to use the BINARY collating sequence.
*/
int sqlite3ExprIsConstantOrGroupBy(Parse *pParse, Expr *p, ExprList *pGroupBy){
Walker w;
w.eCode = 1;
w.xExprCallback = exprNodeIsConstantOrGroupBy;
w.xSelectCallback = 0;
w.u.pGroupBy = pGroupBy;
w.pParse = pParse;
sqlite3WalkExpr(&w, p);
return w.eCode;
}
/*
** Walk an expression tree. Return non-zero if the expression is constant
** or a function call with constant arguments. Return and 0 if there
** are any variables.
**
** For the purposes of this function, a double-quoted string (ex: "abc")
** is considered a variable but a single-quoted string (ex: 'abc') is
** a constant.
*/
int sqlite3ExprIsConstantOrFunction(Expr *p, u8 isInit){
assert( isInit==0 || isInit==1 );
return exprIsConst(p, 4+isInit, 0);
}
#ifdef SQLITE_ENABLE_CURSOR_HINTS
/*
** Walk an expression tree. Return 1 if the expression contains a
** subquery of some kind. Return 0 if there are no subqueries.
*/
int sqlite3ExprContainsSubquery(Expr *p){
Walker w;
w.eCode = 1;
w.xExprCallback = sqlite3ExprWalkNoop;
w.xSelectCallback = sqlite3SelectWalkFail;
#ifdef SQLITE_DEBUG
w.xSelectCallback2 = sqlite3SelectWalkAssert2;
#endif
sqlite3WalkExpr(&w, p);
return w.eCode==0;
}
#endif
/*
** If the expression p codes a constant integer that is small enough
** to fit in a 32-bit integer, return 1 and put the value of the integer
** in *pValue. If the expression is not an integer or if it is too big
** to fit in a signed 32-bit integer, return 0 and leave *pValue unchanged.
*/
int sqlite3ExprIsInteger(Expr *p, int *pValue){
int rc = 0;
if( NEVER(p==0) ) return 0; /* Used to only happen following on OOM */
/* If an expression is an integer literal that fits in a signed 32-bit
** integer, then the EP_IntValue flag will have already been set */
assert( p->op!=TK_INTEGER || (p->flags & EP_IntValue)!=0
|| sqlite3GetInt32(p->u.zToken, &rc)==0 );
if( p->flags & EP_IntValue ){
*pValue = p->u.iValue;
return 1;
}
switch( p->op ){
case TK_UPLUS: {
rc = sqlite3ExprIsInteger(p->pLeft, pValue);
break;
}
case TK_UMINUS: {
int v;
if( sqlite3ExprIsInteger(p->pLeft, &v) ){
assert( v!=(-2147483647-1) );
*pValue = -v;
rc = 1;
}
break;
}
default: break;
}
return rc;
}
/*
** Return FALSE if there is no chance that the expression can be NULL.
**
** If the expression might be NULL or if the expression is too complex
** to tell return TRUE.
**
** This routine is used as an optimization, to skip OP_IsNull opcodes
** when we know that a value cannot be NULL. Hence, a false positive
** (returning TRUE when in fact the expression can never be NULL) might
** be a small performance hit but is otherwise harmless. On the other
** hand, a false negative (returning FALSE when the result could be NULL)
** will likely result in an incorrect answer. So when in doubt, return
** TRUE.
*/
int sqlite3ExprCanBeNull(const Expr *p){
u8 op;
while( p->op==TK_UPLUS || p->op==TK_UMINUS ){
p = p->pLeft;
}
op = p->op;
if( op==TK_REGISTER ) op = p->op2;
switch( op ){
case TK_INTEGER:
case TK_STRING:
case TK_FLOAT:
case TK_BLOB:
return 0;
case TK_COLUMN:
return ExprHasProperty(p, EP_CanBeNull) ||
p->y.pTab==0 || /* Reference to column of index on expression */
(p->iColumn>=0 && p->y.pTab->aCol[p->iColumn].notNull==0);
default:
return 1;
}
}
/*
** Return TRUE if the given expression is a constant which would be
** unchanged by OP_Affinity with the affinity given in the second
** argument.
**
** This routine is used to determine if the OP_Affinity operation
** can be omitted. When in doubt return FALSE. A false negative
** is harmless. A false positive, however, can result in the wrong
** answer.
*/
int sqlite3ExprNeedsNoAffinityChange(const Expr *p, char aff){
u8 op;
int unaryMinus = 0;
if( aff==SQLITE_AFF_BLOB ) return 1;
while( p->op==TK_UPLUS || p->op==TK_UMINUS ){
if( p->op==TK_UMINUS ) unaryMinus = 1;
p = p->pLeft;
}
op = p->op;
if( op==TK_REGISTER ) op = p->op2;
switch( op ){
case TK_INTEGER: {
return aff>=SQLITE_AFF_NUMERIC;
}
case TK_FLOAT: {
return aff>=SQLITE_AFF_NUMERIC;
}
case TK_STRING: {
return !unaryMinus && aff==SQLITE_AFF_TEXT;
}
case TK_BLOB: {
return !unaryMinus;
}
case TK_COLUMN: {
assert( p->iTable>=0 ); /* p cannot be part of a CHECK constraint */
return aff>=SQLITE_AFF_NUMERIC && p->iColumn<0;
}
default: {
return 0;
}
}
}
/*
** Return TRUE if the given string is a row-id column name.
*/
int sqlite3IsRowid(const char *z){
if( sqlite3StrICmp(z, "_ROWID_")==0 ) return 1;
if( sqlite3StrICmp(z, "ROWID")==0 ) return 1;
if( sqlite3StrICmp(z, "OID")==0 ) return 1;
return 0;
}
/*
** pX is the RHS of an IN operator. If pX is a SELECT statement
** that can be simplified to a direct table access, then return
** a pointer to the SELECT statement. If pX is not a SELECT statement,
** or if the SELECT statement needs to be manifested into a transient
** table, then return NULL.
*/
#ifndef SQLITE_OMIT_SUBQUERY
static Select *isCandidateForInOpt(Expr *pX){
Select *p;
SrcList *pSrc;
ExprList *pEList;
Table *pTab;
int i;
if( !ExprHasProperty(pX, EP_xIsSelect) ) return 0; /* Not a subquery */
if( ExprHasProperty(pX, EP_VarSelect) ) return 0; /* Correlated subq */
p = pX->x.pSelect;
if( p->pPrior ) return 0; /* Not a compound SELECT */
if( p->selFlags & (SF_Distinct|SF_Aggregate) ){
testcase( (p->selFlags & (SF_Distinct|SF_Aggregate))==SF_Distinct );
testcase( (p->selFlags & (SF_Distinct|SF_Aggregate))==SF_Aggregate );
return 0; /* No DISTINCT keyword and no aggregate functions */
}
assert( p->pGroupBy==0 ); /* Has no GROUP BY clause */
if( p->pLimit ) return 0; /* Has no LIMIT clause */
if( p->pWhere ) return 0; /* Has no WHERE clause */
pSrc = p->pSrc;
assert( pSrc!=0 );
if( pSrc->nSrc!=1 ) return 0; /* Single term in FROM clause */
if( pSrc->a[0].pSelect ) return 0; /* FROM is not a subquery or view */
pTab = pSrc->a[0].pTab;
assert( pTab!=0 );
assert( pTab->pSelect==0 ); /* FROM clause is not a view */
if( IsVirtual(pTab) ) return 0; /* FROM clause not a virtual table */
pEList = p->pEList;
assert( pEList!=0 );
/* All SELECT results must be columns. */
for(i=0; i<pEList->nExpr; i++){
Expr *pRes = pEList->a[i].pExpr;
if( pRes->op!=TK_COLUMN ) return 0;
assert( pRes->iTable==pSrc->a[0].iCursor ); /* Not a correlated subquery */
}
return p;
}
#endif /* SQLITE_OMIT_SUBQUERY */
#ifndef SQLITE_OMIT_SUBQUERY
/*
** Generate code that checks the left-most column of index table iCur to see if
** it contains any NULL entries. Cause the register at regHasNull to be set
** to a non-NULL value if iCur contains no NULLs. Cause register regHasNull
** to be set to NULL if iCur contains one or more NULL values.
*/
static void sqlite3SetHasNullFlag(Vdbe *v, int iCur, int regHasNull){
int addr1;
sqlite3VdbeAddOp2(v, OP_Integer, 0, regHasNull);
addr1 = sqlite3VdbeAddOp1(v, OP_Rewind, iCur); VdbeCoverage(v);
sqlite3VdbeAddOp3(v, OP_Column, iCur, 0, regHasNull);
sqlite3VdbeChangeP5(v, OPFLAG_TYPEOFARG);
VdbeComment((v, "first_entry_in(%d)", iCur));
sqlite3VdbeJumpHere(v, addr1);
}
#endif
#ifndef SQLITE_OMIT_SUBQUERY
/*
** The argument is an IN operator with a list (not a subquery) on the
** right-hand side. Return TRUE if that list is constant.
*/
static int sqlite3InRhsIsConstant(Expr *pIn){
Expr *pLHS;
int res;
assert( !ExprHasProperty(pIn, EP_xIsSelect) );
pLHS = pIn->pLeft;
pIn->pLeft = 0;
res = sqlite3ExprIsConstant(pIn);
pIn->pLeft = pLHS;
return res;
}
#endif
/*
** This function is used by the implementation of the IN (...) operator.
** The pX parameter is the expression on the RHS of the IN operator, which
** might be either a list of expressions or a subquery.
**
** The job of this routine is to find or create a b-tree object that can
** be used either to test for membership in the RHS set or to iterate through
** all members of the RHS set, skipping duplicates.
**
** A cursor is opened on the b-tree object that is the RHS of the IN operator
** and pX->iTable is set to the index of that cursor.
**
** The returned value of this function indicates the b-tree type, as follows:
**
** IN_INDEX_ROWID - The cursor was opened on a database table.
** IN_INDEX_INDEX_ASC - The cursor was opened on an ascending index.
** IN_INDEX_INDEX_DESC - The cursor was opened on a descending index.
** IN_INDEX_EPH - The cursor was opened on a specially created and
** populated epheremal table.
** IN_INDEX_NOOP - No cursor was allocated. The IN operator must be
** implemented as a sequence of comparisons.
**
** An existing b-tree might be used if the RHS expression pX is a simple
** subquery such as:
**
** SELECT <column1>, <column2>... FROM <table>
**
** If the RHS of the IN operator is a list or a more complex subquery, then
** an ephemeral table might need to be generated from the RHS and then
** pX->iTable made to point to the ephemeral table instead of an
** existing table.
**
** The inFlags parameter must contain, at a minimum, one of the bits
** IN_INDEX_MEMBERSHIP or IN_INDEX_LOOP but not both. If inFlags contains
** IN_INDEX_MEMBERSHIP, then the generated table will be used for a fast
** membership test. When the IN_INDEX_LOOP bit is set, the IN index will
** be used to loop over all values of the RHS of the IN operator.
**
** When IN_INDEX_LOOP is used (and the b-tree will be used to iterate
** through the set members) then the b-tree must not contain duplicates.
** An epheremal table will be created unless the selected columns are guaranteed
** to be unique - either because it is an INTEGER PRIMARY KEY or due to
** a UNIQUE constraint or index.
**
** When IN_INDEX_MEMBERSHIP is used (and the b-tree will be used
** for fast set membership tests) then an epheremal table must
** be used unless <columns> is a single INTEGER PRIMARY KEY column or an
** index can be found with the specified <columns> as its left-most.
**
** If the IN_INDEX_NOOP_OK and IN_INDEX_MEMBERSHIP are both set and
** if the RHS of the IN operator is a list (not a subquery) then this
** routine might decide that creating an ephemeral b-tree for membership
** testing is too expensive and return IN_INDEX_NOOP. In that case, the
** calling routine should implement the IN operator using a sequence
** of Eq or Ne comparison operations.
**
** When the b-tree is being used for membership tests, the calling function
** might need to know whether or not the RHS side of the IN operator
** contains a NULL. If prRhsHasNull is not a NULL pointer and
** if there is any chance that the (...) might contain a NULL value at
** runtime, then a register is allocated and the register number written
** to *prRhsHasNull. If there is no chance that the (...) contains a
** NULL value, then *prRhsHasNull is left unchanged.
**
** If a register is allocated and its location stored in *prRhsHasNull, then
** the value in that register will be NULL if the b-tree contains one or more
** NULL values, and it will be some non-NULL value if the b-tree contains no
** NULL values.
**
** If the aiMap parameter is not NULL, it must point to an array containing
** one element for each column returned by the SELECT statement on the RHS
** of the IN(...) operator. The i'th entry of the array is populated with the
** offset of the index column that matches the i'th column returned by the
** SELECT. For example, if the expression and selected index are:
**
** (?,?,?) IN (SELECT a, b, c FROM t1)
** CREATE INDEX i1 ON t1(b, c, a);
**
** then aiMap[] is populated with {2, 0, 1}.
*/
#ifndef SQLITE_OMIT_SUBQUERY
int sqlite3FindInIndex(
Parse *pParse, /* Parsing context */
Expr *pX, /* The IN expression */
u32 inFlags, /* IN_INDEX_LOOP, _MEMBERSHIP, and/or _NOOP_OK */
int *prRhsHasNull, /* Register holding NULL status. See notes */
int *aiMap, /* Mapping from Index fields to RHS fields */
int *piTab /* OUT: index to use */
){
Select *p; /* SELECT to the right of IN operator */
int eType = 0; /* Type of RHS table. IN_INDEX_* */
int iTab = pParse->nTab++; /* Cursor of the RHS table */
int mustBeUnique; /* True if RHS must be unique */
Vdbe *v = sqlite3GetVdbe(pParse); /* Virtual machine being coded */
assert( pX->op==TK_IN );
mustBeUnique = (inFlags & IN_INDEX_LOOP)!=0;
/* If the RHS of this IN(...) operator is a SELECT, and if it matters
** whether or not the SELECT result contains NULL values, check whether
** or not NULL is actually possible (it may not be, for example, due
** to NOT NULL constraints in the schema). If no NULL values are possible,
** set prRhsHasNull to 0 before continuing. */
if( prRhsHasNull && (pX->flags & EP_xIsSelect) ){
int i;
ExprList *pEList = pX->x.pSelect->pEList;
for(i=0; i<pEList->nExpr; i++){
if( sqlite3ExprCanBeNull(pEList->a[i].pExpr) ) break;
}
if( i==pEList->nExpr ){
prRhsHasNull = 0;
}
}
/* Check to see if an existing table or index can be used to
** satisfy the query. This is preferable to generating a new
** ephemeral table. */
if( pParse->nErr==0 && (p = isCandidateForInOpt(pX))!=0 ){
sqlite3 *db = pParse->db; /* Database connection */
Table *pTab; /* Table <table>. */
i16 iDb; /* Database idx for pTab */
ExprList *pEList = p->pEList;
int nExpr = pEList->nExpr;
assert( p->pEList!=0 ); /* Because of isCandidateForInOpt(p) */
assert( p->pEList->a[0].pExpr!=0 ); /* Because of isCandidateForInOpt(p) */
assert( p->pSrc!=0 ); /* Because of isCandidateForInOpt(p) */
pTab = p->pSrc->a[0].pTab;
/* Code an OP_Transaction and OP_TableLock for <table>. */
iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
sqlite3CodeVerifySchema(pParse, iDb);
sqlite3TableLock(pParse, iDb, pTab->tnum, 0, pTab->zName);
assert(v); /* sqlite3GetVdbe() has always been previously called */
if( nExpr==1 && pEList->a[0].pExpr->iColumn<0 ){
/* The "x IN (SELECT rowid FROM table)" case */
int iAddr = sqlite3VdbeAddOp0(v, OP_Once);
VdbeCoverage(v);
sqlite3OpenTable(pParse, iTab, iDb, pTab, OP_OpenRead);
eType = IN_INDEX_ROWID;
ExplainQueryPlan((pParse, 0,
"USING ROWID SEARCH ON TABLE %s FOR IN-OPERATOR",pTab->zName));
sqlite3VdbeJumpHere(v, iAddr);
}else{
Index *pIdx; /* Iterator variable */
int affinity_ok = 1;
int i;
/* Check that the affinity that will be used to perform each
** comparison is the same as the affinity of each column in table
** on the RHS of the IN operator. If it not, it is not possible to
** use any index of the RHS table. */
for(i=0; i<nExpr && affinity_ok; i++){
Expr *pLhs = sqlite3VectorFieldSubexpr(pX->pLeft, i);
int iCol = pEList->a[i].pExpr->iColumn;
char idxaff = sqlite3TableColumnAffinity(pTab,iCol); /* RHS table */
char cmpaff = sqlite3CompareAffinity(pLhs, idxaff);
testcase( cmpaff==SQLITE_AFF_BLOB );
testcase( cmpaff==SQLITE_AFF_TEXT );
switch( cmpaff ){
case SQLITE_AFF_BLOB:
break;
case SQLITE_AFF_TEXT:
/* sqlite3CompareAffinity() only returns TEXT if one side or the
** other has no affinity and the other side is TEXT. Hence,
** the only way for cmpaff to be TEXT is for idxaff to be TEXT
** and for the term on the LHS of the IN to have no affinity. */
assert( idxaff==SQLITE_AFF_TEXT );
break;
default:
affinity_ok = sqlite3IsNumericAffinity(idxaff);
}
}
if( affinity_ok ){
/* Search for an existing index that will work for this IN operator */
for(pIdx=pTab->pIndex; pIdx && eType==0; pIdx=pIdx->pNext){
Bitmask colUsed; /* Columns of the index used */
Bitmask mCol; /* Mask for the current column */
if( pIdx->nColumn<nExpr ) continue;
if( pIdx->pPartIdxWhere!=0 ) continue;
/* Maximum nColumn is BMS-2, not BMS-1, so that we can compute
** BITMASK(nExpr) without overflowing */
testcase( pIdx->nColumn==BMS-2 );
testcase( pIdx->nColumn==BMS-1 );
if( pIdx->nColumn>=BMS-1 ) continue;
if( mustBeUnique ){
if( pIdx->nKeyCol>nExpr
||(pIdx->nColumn>nExpr && !IsUniqueIndex(pIdx))
){
continue; /* This index is not unique over the IN RHS columns */
}
}
colUsed = 0; /* Columns of index used so far */
for(i=0; i<nExpr; i++){
Expr *pLhs = sqlite3VectorFieldSubexpr(pX->pLeft, i);
Expr *pRhs = pEList->a[i].pExpr;
CollSeq *pReq = sqlite3BinaryCompareCollSeq(pParse, pLhs, pRhs);
int j;
assert( pReq!=0 || pRhs->iColumn==XN_ROWID || pParse->nErr );
for(j=0; j<nExpr; j++){
if( pIdx->aiColumn[j]!=pRhs->iColumn ) continue;
assert( pIdx->azColl[j] );
if( pReq!=0 && sqlite3StrICmp(pReq->zName, pIdx->azColl[j])!=0 ){
continue;
}
break;
}
if( j==nExpr ) break;
mCol = MASKBIT(j);
if( mCol & colUsed ) break; /* Each column used only once */
colUsed |= mCol;
if( aiMap ) aiMap[i] = j;
}
assert( i==nExpr || colUsed!=(MASKBIT(nExpr)-1) );
if( colUsed==(MASKBIT(nExpr)-1) ){
/* If we reach this point, that means the index pIdx is usable */
int iAddr = sqlite3VdbeAddOp0(v, OP_Once); VdbeCoverage(v);
ExplainQueryPlan((pParse, 0,
"USING INDEX %s FOR IN-OPERATOR",pIdx->zName));
sqlite3VdbeAddOp3(v, OP_OpenRead, iTab, pIdx->tnum, iDb);
sqlite3VdbeSetP4KeyInfo(pParse, pIdx);
VdbeComment((v, "%s", pIdx->zName));
assert( IN_INDEX_INDEX_DESC == IN_INDEX_INDEX_ASC+1 );
eType = IN_INDEX_INDEX_ASC + pIdx->aSortOrder[0];
if( prRhsHasNull ){
#ifdef SQLITE_ENABLE_COLUMN_USED_MASK
i64 mask = (1<<nExpr)-1;
sqlite3VdbeAddOp4Dup8(v, OP_ColumnsUsed,
iTab, 0, 0, (u8*)&mask, P4_INT64);
#endif
*prRhsHasNull = ++pParse->nMem;
if( nExpr==1 ){
sqlite3SetHasNullFlag(v, iTab, *prRhsHasNull);
}
}
sqlite3VdbeJumpHere(v, iAddr);
}
} /* End loop over indexes */
} /* End if( affinity_ok ) */
} /* End if not an rowid index */
} /* End attempt to optimize using an index */
/* If no preexisting index is available for the IN clause
** and IN_INDEX_NOOP is an allowed reply
** and the RHS of the IN operator is a list, not a subquery
** and the RHS is not constant or has two or fewer terms,
** then it is not worth creating an ephemeral table to evaluate
** the IN operator so return IN_INDEX_NOOP.
*/
if( eType==0
&& (inFlags & IN_INDEX_NOOP_OK)
&& !ExprHasProperty(pX, EP_xIsSelect)
&& (!sqlite3InRhsIsConstant(pX) || pX->x.pList->nExpr<=2)
){
eType = IN_INDEX_NOOP;
}
if( eType==0 ){
/* Could not find an existing table or index to use as the RHS b-tree.
** We will have to generate an ephemeral table to do the job.
*/
u32 savedNQueryLoop = pParse->nQueryLoop;
int rMayHaveNull = 0;
eType = IN_INDEX_EPH;
if( inFlags & IN_INDEX_LOOP ){
pParse->nQueryLoop = 0;
}else if( prRhsHasNull ){
*prRhsHasNull = rMayHaveNull = ++pParse->nMem;
}
assert( pX->op==TK_IN );
sqlite3CodeRhsOfIN(pParse, pX, iTab);
if( rMayHaveNull ){
sqlite3SetHasNullFlag(v, iTab, rMayHaveNull);
}
pParse->nQueryLoop = savedNQueryLoop;
}
if( aiMap && eType!=IN_INDEX_INDEX_ASC && eType!=IN_INDEX_INDEX_DESC ){
int i, n;
n = sqlite3ExprVectorSize(pX->pLeft);
for(i=0; i<n; i++) aiMap[i] = i;
}
*piTab = iTab;
return eType;
}
#endif
#ifndef SQLITE_OMIT_SUBQUERY
/*
** Argument pExpr is an (?, ?...) IN(...) expression. This
** function allocates and returns a nul-terminated string containing
** the affinities to be used for each column of the comparison.
**
** It is the responsibility of the caller to ensure that the returned
** string is eventually freed using sqlite3DbFree().
*/
static char *exprINAffinity(Parse *pParse, Expr *pExpr){
Expr *pLeft = pExpr->pLeft;
int nVal = sqlite3ExprVectorSize(pLeft);
Select *pSelect = (pExpr->flags & EP_xIsSelect) ? pExpr->x.pSelect : 0;
char *zRet;
assert( pExpr->op==TK_IN );
zRet = sqlite3DbMallocRaw(pParse->db, nVal+1);
if( zRet ){
int i;
for(i=0; i<nVal; i++){
Expr *pA = sqlite3VectorFieldSubexpr(pLeft, i);
char a = sqlite3ExprAffinity(pA);
if( pSelect ){
zRet[i] = sqlite3CompareAffinity(pSelect->pEList->a[i].pExpr, a);
}else{
zRet[i] = a;
}
}
zRet[nVal] = '\0';
}
return zRet;
}
#endif
#ifndef SQLITE_OMIT_SUBQUERY