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sqlite/src/expr.c
drh 7998b889e8 Add an ALWAYS() on a branch in the new indexed-subtype logic. 
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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(const Table *pTab, int iCol){
if( iCol<0 || NEVER(iCol>=pTab->nCol) ) return SQLITE_AFF_INTEGER;
return pTab->aCol[iCol].affinity;
}
/*
** 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(const Expr *pExpr){
int op;
op = pExpr->op;
while( 1 /* exit-by-break */ ){
if( op==TK_COLUMN || (op==TK_AGG_COLUMN && pExpr->y.pTab!=0) ){
assert( ExprUseYTab(pExpr) );
assert( pExpr->y.pTab!=0 );
return sqlite3TableColumnAffinity(pExpr->y.pTab, pExpr->iColumn);
}
if( op==TK_SELECT ){
assert( ExprUseXSelect(pExpr) );
assert( pExpr->x.pSelect!=0 );
assert( pExpr->x.pSelect->pEList!=0 );
assert( pExpr->x.pSelect->pEList->a[0].pExpr!=0 );
return sqlite3ExprAffinity(pExpr->x.pSelect->pEList->a[0].pExpr);
}
#ifndef SQLITE_OMIT_CAST
if( op==TK_CAST ){
assert( !ExprHasProperty(pExpr, EP_IntValue) );
return sqlite3AffinityType(pExpr->u.zToken, 0);
}
#endif
if( op==TK_SELECT_COLUMN ){
assert( pExpr->pLeft!=0 && ExprUseXSelect(pExpr->pLeft) );
assert( pExpr->iColumn < pExpr->iTable );
assert( pExpr->iColumn >= 0 );
assert( pExpr->iTable==pExpr->pLeft->x.pSelect->pEList->nExpr );
return sqlite3ExprAffinity(
pExpr->pLeft->x.pSelect->pEList->a[pExpr->iColumn].pExpr
);
}
if( op==TK_VECTOR ){
assert( ExprUseXList(pExpr) );
return sqlite3ExprAffinity(pExpr->x.pList->a[0].pExpr);
}
if( ExprHasProperty(pExpr, EP_Skip|EP_IfNullRow) ){
assert( pExpr->op==TK_COLLATE
|| pExpr->op==TK_IF_NULL_ROW
|| (pExpr->op==TK_REGISTER && pExpr->op2==TK_IF_NULL_ROW) );
pExpr = pExpr->pLeft;
op = pExpr->op;
continue;
}
if( op!=TK_REGISTER ) break;
op = pExpr->op2;
if( NEVER( op==TK_REGISTER ) ) break;
}
return pExpr->affExpr;
}
/*
** Make a guess at all the possible datatypes of the result that could
** be returned by an expression. Return a bitmask indicating the answer:
**
** 0x01 Numeric
** 0x02 Text
** 0x04 Blob
**
** If the expression must return NULL, then 0x00 is returned.
*/
int sqlite3ExprDataType(const Expr *pExpr){
while( pExpr ){
switch( pExpr->op ){
case TK_COLLATE:
case TK_IF_NULL_ROW:
case TK_UPLUS: {
pExpr = pExpr->pLeft;
break;
}
case TK_NULL: {
pExpr = 0;
break;
}
case TK_STRING: {
return 0x02;
}
case TK_BLOB: {
return 0x04;
}
case TK_CONCAT: {
return 0x06;
}
case TK_VARIABLE:
case TK_AGG_FUNCTION:
case TK_FUNCTION: {
return 0x07;
}
case TK_COLUMN:
case TK_AGG_COLUMN:
case TK_SELECT:
case TK_CAST:
case TK_SELECT_COLUMN:
case TK_VECTOR: {
int aff = sqlite3ExprAffinity(pExpr);
if( aff>=SQLITE_AFF_NUMERIC ) return 0x05;
if( aff==SQLITE_AFF_TEXT ) return 0x06;
return 0x07;
}
case TK_CASE: {
int res = 0;
int ii;
ExprList *pList = pExpr->x.pList;
assert( ExprUseXList(pExpr) && pList!=0 );
assert( pList->nExpr > 0);
for(ii=1; ii<pList->nExpr; ii+=2){
res |= sqlite3ExprDataType(pList->a[ii].pExpr);
}
if( pList->nExpr % 2 ){
res |= sqlite3ExprDataType(pList->a[pList->nExpr-1].pExpr);
}
return res;
}
default: {
return 0x01;
}
} /* End of switch(op) */
} /* End of while(pExpr) */
return 0x00;
}
/*
** 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(
const 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(
const Parse *pParse, /* Parsing context */
Expr *pExpr, /* Add the "COLLATE" clause to this expression */
const char *zC /* The collating sequence name */
){
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( ExprUseXList(pExpr) );
assert( pExpr->x.pList->nExpr>0 );
assert( pExpr->op==TK_FUNCTION );
pExpr = pExpr->x.pList->a[0].pExpr;
}else if( pExpr->op==TK_COLLATE ){
pExpr = pExpr->pLeft;
}else{
break;
}
}
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, const Expr *pExpr){
sqlite3 *db = pParse->db;
CollSeq *pColl = 0;
const Expr *p = pExpr;
while( p ){
int op = p->op;
if( op==TK_REGISTER ) op = p->op2;
if( (op==TK_AGG_COLUMN && p->y.pTab!=0)
|| op==TK_COLUMN || op==TK_TRIGGER
){
int j;
assert( ExprUseYTab(p) );
assert( p->y.pTab!=0 );
if( (j = p->iColumn)>=0 ){
const char *zColl = sqlite3ColumnColl(&p->y.pTab->aCol[j]);
pColl = sqlite3FindCollSeq(db, ENC(db), zColl, 0);
}
break;
}
if( op==TK_CAST || op==TK_UPLUS ){
p = p->pLeft;
continue;
}
if( op==TK_VECTOR ){
assert( ExprUseXList(p) );
p = p->x.pList->a[0].pExpr;
continue;
}
if( op==TK_COLLATE ){
assert( !ExprHasProperty(p, EP_IntValue) );
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( !ExprUseXList(p) || p->x.pList==0 || p->pRight==0 );
if( ExprUseXList(p) && p->x.pList!=0 && !db->mallocFailed ){
int i;
for(i=0; 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
** default 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, const 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, const Expr *pE1, const 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(const 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(const 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( ExprUseXSelect(pExpr) ){
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(const 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(
const Expr *pExpr1, /* Left operand */
const Expr *pExpr2, /* Right operand */
int jumpIfNull /* Extra flags added to P5 */
){
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,
const Expr *pLeft,
const 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;
}
/* Expression p is a comparison operator. Return a collation sequence
** appropriate for the comparison operator.
**
** This is normally just a wrapper around sqlite3BinaryCompareCollSeq().
** However, if the OP_Commuted flag is set, then the order of the operands
** is reversed in the sqlite3BinaryCompareCollSeq() call so that the
** correct collating sequence is found.
*/
CollSeq *sqlite3ExprCompareCollSeq(Parse *pParse, const Expr *p){
if( ExprHasProperty(p, EP_Commuted) ){
return sqlite3BinaryCompareCollSeq(pParse, p->pRight, p->pLeft);
}else{
return sqlite3BinaryCompareCollSeq(pParse, p->pLeft, p->pRight);
}
}
/*
** 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 isCommuted /* The comparison has been commuted */
){
int p5;
int addr;
CollSeq *p4;
if( pParse->nErr ) return 0;
if( isCommuted ){
p4 = sqlite3BinaryCompareCollSeq(pParse, pRight, pLeft);
}else{
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(const 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(const Expr *pExpr){
u8 op = pExpr->op;
if( op==TK_REGISTER ) op = pExpr->op2;
if( op==TK_VECTOR ){
assert( ExprUseXList(pExpr) );
return pExpr->x.pList->nExpr;
}else if( op==TK_SELECT ){
assert( ExprUseXSelect(pExpr) );
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) || pVector->op==TK_ERROR );
if( sqlite3ExprIsVector(pVector) ){
assert( pVector->op2==0 || pVector->op==TK_REGISTER );
if( pVector->op==TK_SELECT || pVector->op2==TK_SELECT ){
assert( ExprUseXSelect(pVector) );
return pVector->x.pSelect->pEList->a[i].pExpr;
}else{
assert( ExprUseXList(pVector) );
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 */
int nField /* Total number of columns in the vector */
){
Expr *pRet;
if( pVector->op==TK_SELECT ){
assert( ExprUseXSelect(pVector) );
/* 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 ){
ExprSetProperty(pRet, EP_FullSize);
pRet->iTable = nField;
pRet->iColumn = iField;
pRet->pLeft = pVector;
}
}else{
if( pVector->op==TK_VECTOR ){
Expr **ppVector;
assert( ExprUseXList(pVector) );
ppVector = &pVector->x.pList->a[iField].pExpr;
pVector = *ppVector;
if( IN_RENAME_OBJECT ){
/* This must be a vector UPDATE inside a trigger */
*ppVector = 0;
return pVector;
}
}
pRet = sqlite3ExprDup(pParse->db, pVector, 0);
}
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 || op==TK_ERROR );
if( op==TK_REGISTER ){
*ppExpr = sqlite3VectorFieldSubexpr(pVector, iField);
return pVector->iTable+iField;
}
if( op==TK_SELECT ){
assert( ExprUseXSelect(pVector) );
*ppExpr = pVector->x.pSelect->pEList->a[iField].pExpr;
return regSelect+iField;
}
if( op==TK_VECTOR ){
assert( ExprUseXList(pVector) );
*ppExpr = pVector->x.pList->a[iField].pExpr;
return sqlite3ExprCodeTemp(pParse, *ppExpr, pRegFree);
}
return 0;
}
/*
** 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 addrCmp = 0;
int addrDone = sqlite3VdbeMakeLabel(pParse);
int isCommuted = ExprHasProperty(pExpr,EP_Commuted);
assert( !ExprHasVVAProperty(pExpr,EP_Immutable) );
if( pParse->nErr ) return;
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 );
if( op==TK_LE ) opx = TK_LT;
if( op==TK_GE ) opx = TK_GT;
if( op==TK_NE ) opx = TK_EQ;
regLeft = exprCodeSubselect(pParse, pLeft);
regRight = exprCodeSubselect(pParse, pRight);
sqlite3VdbeAddOp2(v, OP_Integer, 1, dest);
for(i=0; 1 /*Loop exits by "break"*/; i++){
int regFree1 = 0, regFree2 = 0;
Expr *pL = 0, *pR = 0;
int r1, r2;
assert( i>=0 && i<nLeft );
if( addrCmp ) sqlite3VdbeJumpHere(v, addrCmp);
r1 = exprVectorRegister(pParse, pLeft, i, regLeft, &pL, &regFree1);
r2 = exprVectorRegister(pParse, pRight, i, regRight, &pR, &regFree2);
addrCmp = sqlite3VdbeCurrentAddr(v);
codeCompare(pParse, pL, pR, opx, r1, r2, addrDone, p5, isCommuted);
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( (opx==TK_LT || opx==TK_GT) && i<nLeft-1 ){
addrCmp = sqlite3VdbeAddOp0(v, OP_ElseEq);
testcase(opx==TK_LT); VdbeCoverageIf(v,opx==TK_LT);
testcase(opx==TK_GT); VdbeCoverageIf(v,opx==TK_GT);
}
if( p5==SQLITE_NULLEQ ){
sqlite3VdbeAddOp2(v, OP_Integer, 0, dest);
}else{
sqlite3VdbeAddOp3(v, OP_ZeroOrNull, r1, dest, r2);
}
if( i==nLeft-1 ){
break;
}
if( opx==TK_EQ ){
sqlite3VdbeAddOp2(v, OP_NotNull, dest, addrDone); VdbeCoverage(v);
}else{
assert( op==TK_LT || op==TK_GT || op==TK_LE || op==TK_GE );
sqlite3VdbeAddOp2(v, OP_Goto, 0, addrDone);
if( i==nLeft-2 ) opx = op;
}
}
sqlite3VdbeJumpHere(v, addrCmp);
sqlite3VdbeResolveLabel(v, addrDone);
if( op==TK_NE ){
sqlite3VdbeAddOp2(v, OP_Not, dest, dest);
}
}
#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(const Expr *p, int *pnHeight){
if( p ){
if( p->nHeight>*pnHeight ){
*pnHeight = p->nHeight;
}
}
}
static void heightOfExprList(const ExprList *p, int *pnHeight){
if( p ){
int i;
for(i=0; i<p->nExpr; i++){
heightOfExpr(p->a[i].pExpr, pnHeight);
}
}
}
static void heightOfSelect(const Select *pSelect, int *pnHeight){
const 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 = p->pLeft ? p->pLeft->nHeight : 0;
if( NEVER(p->pRight) && p->pRight->nHeight>nHeight ){
nHeight = p->pRight->nHeight;
}
if( ExprUseXSelect(p) ){
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(const 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( pParse->nErr ) return;
if( p && ExprUseXList(p) && p->x.pList ){
p->flags |= EP_Propagate & sqlite3ExprListFlags(p->x.pList);
}
}
#define exprSetHeight(y)
#endif /* SQLITE_MAX_EXPR_DEPTH>0 */
/*
** Set the error offset for an Expr node, if possible.
*/
void sqlite3ExprSetErrorOffset(Expr *pExpr, int iOfst){
if( pExpr==0 ) return;
if( NEVER(ExprUseWJoin(pExpr)) ) return;
pExpr->w.iOfst = iOfst;
}
/*
** 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 (tag-20240227-a): 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.
** See also tag-20240227-b.
*/
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; /* tag-20240227-a */
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{
assert( ExprUseXList(pRoot) );
assert( pRoot->x.pSelect==0 );
if( pRight ){
pRoot->pRight = pRight;
pRoot->flags |= EP_Propagate & pRight->flags;
#if SQLITE_MAX_EXPR_DEPTH>0
pRoot->nHeight = pRight->nHeight+1;
}else{
pRoot->nHeight = 1;
#endif
}
if( pLeft ){
pRoot->pLeft = pLeft;
pRoot->flags |= EP_Propagate & pLeft->flags;
#if SQLITE_MAX_EXPR_DEPTH>0
if( pLeft->nHeight>=pRoot->nHeight ){
pRoot->nHeight = pLeft->nHeight+1;
}
#endif
}
}
}
/*
** 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);
}
}
/*
** Expression list pEList is a list of vector values. This function
** converts the contents of pEList to a VALUES(...) Select statement
** returning 1 row for each element of the list. For example, the
** expression list:
**
** ( (1,2), (3,4) (5,6) )
**
** is translated to the equivalent of:
**
** VALUES(1,2), (3,4), (5,6)
**
** Each of the vector values in pEList must contain exactly nElem terms.
** If a list element that is not a vector or does not contain nElem terms,
** an error message is left in pParse.
**
** This is used as part of processing IN(...) expressions with a list
** of vectors on the RHS. e.g. "... IN ((1,2), (3,4), (5,6))".
*/
Select *sqlite3ExprListToValues(Parse *pParse, int nElem, ExprList *pEList){
int ii;
Select *pRet = 0;
assert( nElem>1 );
for(ii=0; ii<pEList->nExpr; ii++){
Select *pSel;
Expr *pExpr = pEList->a[ii].pExpr;
int nExprElem;
if( pExpr->op==TK_VECTOR ){
assert( ExprUseXList(pExpr) );
nExprElem = pExpr->x.pList->nExpr;
}else{
nExprElem = 1;
}
if( nExprElem!=nElem ){
sqlite3ErrorMsg(pParse, "IN(...) element has %d term%s - expected %d",
nExprElem, nExprElem>1?"s":"", nElem
);
break;
}
assert( ExprUseXList(pExpr) );
pSel = sqlite3SelectNew(pParse, pExpr->x.pList, 0, 0, 0, 0, 0, SF_Values,0);
pExpr->x.pList = 0;
if( pSel ){
if( pRet ){
pSel->op = TK_ALL;
pSel->pPrior = pRet;
}
pRet = pSel;
}
}
if( pRet && pRet->pPrior ){
pRet->selFlags |= SF_MultiValue;
}
sqlite3ExprListDelete(pParse->db, pEList);
return pRet;
}
/*
** 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, and neither side
** is part of an ON clause, 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{
u32 f = pLeft->flags | pRight->flags;
if( (f&(EP_OuterON|EP_InnerON|EP_IsFalse))==EP_IsFalse
&& !IN_RENAME_OBJECT
){
sqlite3ExprDeferredDelete(pParse, pLeft);
sqlite3ExprDeferredDelete(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 */
const 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;
}
assert( !ExprHasProperty(pNew, EP_InnerON|EP_OuterON) );
pNew->w.iOfst = (int)(pToken->z - pParse->zTail);
if( pList
&& pList->nExpr > pParse->db->aLimit[SQLITE_LIMIT_FUNCTION_ARG]
&& !pParse->nested
){
sqlite3ErrorMsg(pParse, "too many arguments on function %T", pToken);
}
pNew->x.pList = pList;
ExprSetProperty(pNew, EP_HasFunc);
assert( ExprUseXList(pNew) );
sqlite3ExprSetHeightAndFlags(pParse, pNew);
if( eDistinct==SF_Distinct ) ExprSetProperty(pNew, EP_Distinct);
return pNew;
}
/*
** Report an error when attempting to use an ORDER BY clause within
** the arguments of a non-aggregate function.
*/
void sqlite3ExprOrderByAggregateError(Parse *pParse, Expr *p){
sqlite3ErrorMsg(pParse,
"ORDER BY may not be used with non-aggregate %#T()", p
);
}
/*
** Attach an ORDER BY clause to a function call.
**
** functionname( arguments ORDER BY sortlist )
** \_____________________/ \______/
** pExpr pOrderBy
**
** The ORDER BY clause is inserted into a new Expr node of type TK_ORDER
** and added to the Expr.pLeft field of the parent TK_FUNCTION node.
*/
void sqlite3ExprAddFunctionOrderBy(
Parse *pParse, /* Parsing context */
Expr *pExpr, /* The function call to which ORDER BY is to be added */
ExprList *pOrderBy /* The ORDER BY clause to add */
){
Expr *pOB;
sqlite3 *db = pParse->db;
if( NEVER(pOrderBy==0) ){
assert( db->mallocFailed );
return;
}
if( pExpr==0 ){
assert( db->mallocFailed );
sqlite3ExprListDelete(db, pOrderBy);
return;
}
assert( pExpr->op==TK_FUNCTION );
assert( pExpr->pLeft==0 );
assert( ExprUseXList(pExpr) );
if( pExpr->x.pList==0 || NEVER(pExpr->x.pList->nExpr==0) ){
/* Ignore ORDER BY on zero-argument aggregates */
sqlite3ParserAddCleanup(pParse, sqlite3ExprListDeleteGeneric, pOrderBy);
return;
}
if( IsWindowFunc(pExpr) ){
sqlite3ExprOrderByAggregateError(pParse, pExpr);
sqlite3ExprListDelete(db, pOrderBy);
return;
}
pOB = sqlite3ExprAlloc(db, TK_ORDER, 0, 0);
if( pOB==0 ){
sqlite3ExprListDelete(db, pOrderBy);
return;
}
pOB->x.pList = pOrderBy;
assert( ExprUseXList(pOB) );
pExpr->pLeft = pOB;
ExprSetProperty(pOB, EP_FullSize);
}
/*
** Check to see if a function is usable according to current access
** rules:
**
** SQLITE_FUNC_DIRECT - Only usable from top-level SQL
**
** SQLITE_FUNC_UNSAFE - Usable if TRUSTED_SCHEMA or from
** top-level SQL
**
** If the function is not usable, create an error.
*/
void sqlite3ExprFunctionUsable(
Parse *pParse, /* Parsing and code generating context */
const Expr *pExpr, /* The function invocation */
const FuncDef *pDef /* The function being invoked */
){
assert( !IN_RENAME_OBJECT );
assert( (pDef->funcFlags & (SQLITE_FUNC_DIRECT|SQLITE_FUNC_UNSAFE))!=0 );
if( ExprHasProperty(pExpr, EP_FromDDL) ){
if( (pDef->funcFlags & SQLITE_FUNC_DIRECT)!=0
|| (pParse->db->flags & SQLITE_TrustedSchema)==0
){
/* Functions prohibited in triggers and views if:
** (1) tagged with SQLITE_DIRECTONLY
** (2) not tagged with SQLITE_INNOCUOUS (which means it
** is tagged with SQLITE_FUNC_UNSAFE) and
** SQLITE_DBCONFIG_TRUSTED_SCHEMA is off (meaning
** that the schema is possibly tainted).
*/
sqlite3ErrorMsg(pParse, "unsafe use of %#T()", pExpr);
}
}
}
/*
** 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 "$aaa" are assigned the same number
** as the previous instance of the same wildcard. Or if this is the first
** instance of the wildcard, the next sequential variable number is
** assigned.
*/
void sqlite3ExprAssignVarNumber(Parse *pParse, Expr *pExpr, u32 n){
sqlite3 *db = pParse->db;
const char *z;
ynVar x;
if( pExpr==0 ) return;
assert( !ExprHasProperty(pExpr, EP_IntValue|EP_Reduced|EP_TokenOnly) );
z = pExpr->u.zToken;
assert( z!=0 );
assert( z[0]!=0 );
assert( n==(u32)sqlite3Strlen30(z) );
if( z[1]==0 ){
/* Wildcard of the form "?". Assign the next variable number */
assert( z[0]=='?' );
x = (ynVar)(++pParse->nVar);
}else{
int doAdd = 0;
if( z[0]=='?' ){
/* Wildcard of the form "?nnn". Convert "nnn" to an integer and
** use it as the variable number */
i64 i;
int bOk;
if( n==2 ){ /*OPTIMIZATION-IF-TRUE*/
i = z[1]-'0'; /* The common case of ?N for a single digit N */
bOk = 1;
}else{
bOk = 0==sqlite3Atoi64(&z[1], &i, n-1, SQLITE_UTF8);
}
testcase( i==0 );
testcase( i==1 );
testcase( i==db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER]-1 );
testcase( i==db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER] );
if( bOk==0 || i<1 || i>db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER] ){
sqlite3ErrorMsg(pParse, "variable number must be between ?1 and ?%d",
db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER]);
sqlite3RecordErrorOffsetOfExpr(pParse->db, pExpr);
return;
}
x = (ynVar)i;
if( x>pParse->nVar ){
pParse->nVar = (int)x;
doAdd = 1;
}else if( sqlite3VListNumToName(pParse->pVList, x)==0 ){
doAdd = 1;
}
}else{
/* Wildcards like ":aaa", "$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");
sqlite3RecordErrorOffsetOfExpr(pParse->db, pExpr);
}
}
/*
** Recursively delete an expression tree.
*/
static SQLITE_NOINLINE void sqlite3ExprDeleteNN(sqlite3 *db, Expr *p){
assert( p!=0 );
assert( db!=0 );
exprDeleteRestart:
assert( !ExprUseUValue(p) || p->u.iValue>=0 );
assert( !ExprUseYWin(p) || !ExprUseYSub(p) );
assert( !ExprUseYWin(p) || p->y.pWin!=0 || db->mallocFailed );
assert( p->op!=TK_FUNCTION || !ExprUseYSub(p) );
#ifdef SQLITE_DEBUG
if( ExprHasProperty(p, EP_Leaf) && !ExprHasProperty(p, EP_TokenOnly) ){
assert( p->pLeft==0 );
assert( p->pRight==0 );
assert( !ExprUseXSelect(p) || p->x.pSelect==0 );
assert( !ExprUseXList(p) || p->x.pList==0 );
}
#endif
if( !ExprHasProperty(p, (EP_TokenOnly|EP_Leaf)) ){
/* The Expr.x union is never used at the same time as Expr.pRight */
assert( (ExprUseXList(p) && p->x.pList==0) || p->pRight==0 );
if( p->pRight ){
assert( !ExprHasProperty(p, EP_WinFunc) );
sqlite3ExprDeleteNN(db, p->pRight);
}else if( ExprUseXSelect(p) ){
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( p->pLeft && p->op!=TK_SELECT_COLUMN ){
Expr *pLeft = p->pLeft;
if( !ExprHasProperty(p, EP_Static)
&& !ExprHasProperty(pLeft, EP_Static)
){
/* Avoid unnecessary recursion on unary operators */
sqlite3DbNNFreeNN(db, p);
p = pLeft;
goto exprDeleteRestart;
}else{
sqlite3ExprDeleteNN(db, pLeft);
}
}
}
if( !ExprHasProperty(p, EP_Static) ){
sqlite3DbNNFreeNN(db, p);
}
}
void sqlite3ExprDelete(sqlite3 *db, Expr *p){
if( p ) sqlite3ExprDeleteNN(db, p);
}
void sqlite3ExprDeleteGeneric(sqlite3 *db, void *p){
if( ALWAYS(p) ) sqlite3ExprDeleteNN(db, (Expr*)p);
}
/*
** Clear both elements of an OnOrUsing object
*/
void sqlite3ClearOnOrUsing(sqlite3 *db, OnOrUsing *p){
if( p==0 ){
/* Nothing to clear */
}else if( p->pOn ){
sqlite3ExprDeleteNN(db, p->pOn);
}else if( p->pUsing ){
sqlite3IdListDelete(db, p->pUsing);
}
}
/*
** Arrange to cause pExpr to be deleted when the pParse is deleted.
** This is similar to sqlite3ExprDelete() except that the delete is
** deferred until the pParse is deleted.
**
** The pExpr might be deleted immediately on an OOM error.
**
** Return 0 if the delete was successfully deferred. Return non-zero
** if the delete happened immediately because of an OOM.
*/
int sqlite3ExprDeferredDelete(Parse *pParse, Expr *pExpr){
return 0==sqlite3ParserAddCleanup(pParse, sqlite3ExprDeleteGeneric, pExpr);
}
/* 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(const 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(const 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 || ExprHasProperty(p, EP_FullSize) ){
nSize = EXPR_FULLSIZE;
}else{
assert( !ExprHasProperty(p, EP_TokenOnly|EP_Reduced) );
assert( !ExprHasProperty(p, EP_OuterON) );
assert( !ExprHasVVAProperty(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(const 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 value returned includes space to create a copy of the Expr struct
** itself and the buffer referred to by Expr.u.zToken, if any.
**
** The return value includes space to duplicate all Expr nodes in the
** tree formed by Expr.pLeft and Expr.pRight, but not any other
** substructure such as Expr.x.pList, Expr.x.pSelect, and Expr.y.pWin.
*/
static int dupedExprSize(const Expr *p){
int nByte;
assert( p!=0 );
nByte = dupedExprNodeSize(p, EXPRDUP_REDUCE);
if( p->pLeft ) nByte += dupedExprSize(p->pLeft);
if( p->pRight ) nByte += dupedExprSize(p->pRight);
assert( nByte==ROUND8(nByte) );
return nByte;
}
/*
** An EdupBuf is a memory allocation used to stored multiple Expr objects
** together with their Expr.zToken content. This is used to help implement
** compression while doing sqlite3ExprDup(). The top-level Expr does the
** allocation for itself and many of its decendents, then passes an instance
** of the structure down into exprDup() so that they decendents can have
** access to that memory.
*/
typedef struct EdupBuf EdupBuf;
struct EdupBuf {
u8 *zAlloc; /* Memory space available for storage */
#ifdef SQLITE_DEBUG
u8 *zEnd; /* First byte past the end of memory */
#endif
};
/*
** This function is similar to sqlite3ExprDup(), except that if pEdupBuf
** is not NULL then it points to memory that can be used to store a copy
** of the input Expr p together with its p->u.zToken (if any). pEdupBuf
** is updated with the new buffer tail prior to returning.
*/
static Expr *exprDup(
sqlite3 *db, /* Database connection (for memory allocation) */
const Expr *p, /* Expr tree to be duplicated */
int dupFlags, /* EXPRDUP_REDUCE for compression. 0 if not */
EdupBuf *pEdupBuf /* Preallocated storage space, or NULL */
){
Expr *pNew; /* Value to return */
EdupBuf sEdupBuf; /* Memory space from which to build Expr object */
u32 staticFlag; /* EP_Static if space not obtained from malloc */
int nToken = -1; /* Space needed for p->u.zToken. -1 means unknown */
assert( db!=0 );
assert( p );
assert( dupFlags==0 || dupFlags==EXPRDUP_REDUCE );
assert( pEdupBuf==0 || dupFlags==EXPRDUP_REDUCE );
/* Figure out where to write the new Expr structure. */
if( pEdupBuf ){
sEdupBuf.zAlloc = pEdupBuf->zAlloc;
#ifdef SQLITE_DEBUG
sEdupBuf.zEnd = pEdupBuf->zEnd;
#endif
staticFlag = EP_Static;
assert( sEdupBuf.zAlloc!=0 );
assert( dupFlags==EXPRDUP_REDUCE );
}else{
int nAlloc;
if( dupFlags ){
nAlloc = dupedExprSize(p);
}else if( !ExprHasProperty(p, EP_IntValue) && p->u.zToken ){
nToken = sqlite3Strlen30NN(p->u.zToken)+1;
nAlloc = ROUND8(EXPR_FULLSIZE + nToken);
}else{
nToken = 0;
nAlloc = ROUND8(EXPR_FULLSIZE);
}
assert( nAlloc==ROUND8(nAlloc) );
sEdupBuf.zAlloc = sqlite3DbMallocRawNN(db, nAlloc);
#ifdef SQLITE_DEBUG
sEdupBuf.zEnd = sEdupBuf.zAlloc ? sEdupBuf.zAlloc+nAlloc : 0;
#endif
staticFlag = 0;
}
pNew = (Expr *)sEdupBuf.zAlloc;
assert( EIGHT_BYTE_ALIGNMENT(pNew) );
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);
int nNewSize = nStructSize & 0xfff;
if( nToken<0 ){
if( !ExprHasProperty(p, EP_IntValue) && p->u.zToken ){
nToken = sqlite3Strlen30(p->u.zToken) + 1;
}else{
nToken = 0;
}
}
if( dupFlags ){
assert( (int)(sEdupBuf.zEnd - sEdupBuf.zAlloc) >= nNewSize+nToken );
assert( ExprHasProperty(p, EP_Reduced)==0 );
memcpy(sEdupBuf.zAlloc, p, nNewSize);
}else{
u32 nSize = (u32)exprStructSize(p);
assert( (int)(sEdupBuf.zEnd - sEdupBuf.zAlloc) >=
(int)EXPR_FULLSIZE+nToken );
memcpy(sEdupBuf.zAlloc, p, nSize);
if( nSize<EXPR_FULLSIZE ){
memset(&sEdupBuf.zAlloc[nSize], 0, EXPR_FULLSIZE-nSize);
}
nNewSize = EXPR_FULLSIZE;
}
/* Set the EP_Reduced, EP_TokenOnly, and EP_Static flags appropriately. */
pNew->flags &= ~(EP_Reduced|EP_TokenOnly|EP_Static);
pNew->flags |= nStructSize & (EP_Reduced|EP_TokenOnly);
pNew->flags |= staticFlag;
ExprClearVVAProperties(pNew);
if( dupFlags ){
ExprSetVVAProperty(pNew, EP_Immutable);
}
/* Copy the p->u.zToken string, if any. */
assert( nToken>=0 );
if( nToken>0 ){
char *zToken = pNew->u.zToken = (char*)&sEdupBuf.zAlloc[nNewSize];
memcpy(zToken, p->u.zToken, nToken);
nNewSize += nToken;
}
sEdupBuf.zAlloc += ROUND8(nNewSize);
if( ((p->flags|pNew->flags)&(EP_TokenOnly|EP_Leaf))==0 ){
/* Fill in the pNew->x.pSelect or pNew->x.pList member. */
if( ExprUseXSelect(p) ){
pNew->x.pSelect = sqlite3SelectDup(db, p->x.pSelect, dupFlags);
}else{
pNew->x.pList = sqlite3ExprListDup(db, p->x.pList,
p->op!=TK_ORDER ? dupFlags : 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 */
/* Fill in pNew->pLeft and pNew->pRight. */
if( dupFlags ){
if( p->op==TK_SELECT_COLUMN ){
pNew->pLeft = p->pLeft;
assert( p->pRight==0
|| p->pRight==p->pLeft
|| ExprHasProperty(p->pLeft, EP_Subquery) );
}else{
pNew->pLeft = p->pLeft ?
exprDup(db, p->pLeft, EXPRDUP_REDUCE, &sEdupBuf) : 0;
}
pNew->pRight = p->pRight ?
exprDup(db, p->pRight, EXPRDUP_REDUCE, &sEdupBuf) : 0;
}else{
if( p->op==TK_SELECT_COLUMN ){
pNew->pLeft = p->pLeft;
assert( p->pRight==0
|| p->pRight==p->pLeft
|| ExprHasProperty(p->pLeft, EP_Subquery) );
}else{
pNew->pLeft = sqlite3ExprDup(db, p->pLeft, 0);
}
pNew->pRight = sqlite3ExprDup(db, p->pRight, 0);
}
}
}
if( pEdupBuf ) memcpy(pEdupBuf, &sEdupBuf, sizeof(sEdupBuf));
assert( sEdupBuf.zAlloc <= sEdupBuf.zEnd );
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
With *sqlite3WithDup(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);
pRet->a[i].eM10d = p->a[i].eM10d;
}
}
}
return pRet;
}
#else
# define sqlite3WithDup(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, const Expr *p, int flags){
assert( flags==0 || flags==EXPRDUP_REDUCE );
return p ? exprDup(db, p, flags, 0) : 0;
}
ExprList *sqlite3ExprListDup(sqlite3 *db, const ExprList *p, int flags){
ExprList *pNew;
struct ExprList_item *pItem;
const struct ExprList_item *pOldItem;
int i;
Expr *pPriorSelectColOld = 0;
Expr *pPriorSelectColNew = 0;
assert( db!=0 );
if( p==0 ) return 0;
pNew = sqlite3DbMallocRawNN(db, sqlite3DbMallocSize(db, p));
if( pNew==0 ) return 0;
pNew->nExpr = p->nExpr;
pNew->nAlloc = p->nAlloc;
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
){
if( pNewExpr->pRight ){
pPriorSelectColOld = pOldExpr->pRight;
pPriorSelectColNew = pNewExpr->pRight;
pNewExpr->pLeft = pNewExpr->pRight;
}else{
if( pOldExpr->pLeft!=pPriorSelectColOld ){
pPriorSelectColOld = pOldExpr->pLeft;
pPriorSelectColNew = sqlite3ExprDup(db, pPriorSelectColOld, flags);
pNewExpr->pRight = pPriorSelectColNew;
}
pNewExpr->pLeft = pPriorSelectColNew;
}
}
pItem->zEName = sqlite3DbStrDup(db, pOldItem->zEName);
pItem->fg = pOldItem->fg;
pItem->fg.done = 0;
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, const 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++){
SrcItem *pNewItem = &pNew->a[i];
const SrcItem *pOldItem = &p->a[i];
Table *pTab;
pNewItem->fg = pOldItem->fg;
if( pOldItem->fg.isSubquery ){
Subquery *pNewSubq = sqlite3DbMallocRaw(db, sizeof(Subquery));
if( pNewSubq==0 ){
assert( db->mallocFailed );
pNewItem->fg.isSubquery = 0;
}else{
memcpy(pNewSubq, pOldItem->u4.pSubq, sizeof(*pNewSubq));
pNewSubq->pSelect = sqlite3SelectDup(db, pNewSubq->pSelect, flags);
if( pNewSubq->pSelect==0 ){
sqlite3DbFree(db, pNewSubq);
pNewSubq = 0;
pNewItem->fg.isSubquery = 0;
}
}
pNewItem->u4.pSubq = pNewSubq;
}else if( pOldItem->fg.fixedSchema ){
pNewItem->u4.pSchema = pOldItem->u4.pSchema;
}else{
pNewItem->u4.zDatabase = sqlite3DbStrDup(db, pOldItem->u4.zDatabase);
}
pNewItem->zName = sqlite3DbStrDup(db, pOldItem->zName);
pNewItem->zAlias = sqlite3DbStrDup(db, pOldItem->zAlias);
pNewItem->iCursor = pOldItem->iCursor;
if( pNewItem->fg.isIndexedBy ){
pNewItem->u1.zIndexedBy = sqlite3DbStrDup(db, pOldItem->u1.zIndexedBy);
}else if( pNewItem->fg.isTabFunc ){
pNewItem->u1.pFuncArg =
sqlite3ExprListDup(db, pOldItem->u1.pFuncArg, flags);
}else{
pNewItem->u1.nRow = pOldItem->u1.nRow;
}
pNewItem->u2 = pOldItem->u2;
if( pNewItem->fg.isCte ){
pNewItem->u2.pCteUse->nUse++;
}
pTab = pNewItem->pSTab = pOldItem->pSTab;
if( pTab ){
pTab->nTabRef++;
}
if( pOldItem->fg.isUsing ){
assert( pNewItem->fg.isUsing );
pNewItem->u3.pUsing = sqlite3IdListDup(db, pOldItem->u3.pUsing);
}else{
pNewItem->u3.pOn = sqlite3ExprDup(db, pOldItem->u3.pOn, flags);
}
pNewItem->colUsed = pOldItem->colUsed;
}
return pNew;
}
IdList *sqlite3IdListDup(sqlite3 *db, const IdList *p){
IdList *pNew;
int i;
assert( db!=0 );
if( p==0 ) return 0;
assert( p->eU4!=EU4_EXPR );
pNew = sqlite3DbMallocRawNN(db, sizeof(*pNew)+(p->nId-1)*sizeof(p->a[0]) );
if( pNew==0 ) return 0;
pNew->nId = p->nId;
pNew->eU4 = p->eU4;
for(i=0; i<p->nId; i++){
struct IdList_item *pNewItem = &pNew->a[i];
const struct IdList_item *pOldItem = &p->a[i];
pNewItem->zName = sqlite3DbStrDup(db, pOldItem->zName);
pNewItem->u4 = pOldItem->u4;
}
return pNew;
}
Select *sqlite3SelectDup(sqlite3 *db, const Select *pDup, int flags){
Select *pRet = 0;
Select *pNext = 0;
Select **pp = &pRet;
const 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 = sqlite3WithDup(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;
if( db->mallocFailed ){
/* Any prior OOM might have left the Select object incomplete.
** Delete the whole thing rather than allow an incomplete Select
** to be used by the code generator. */
pNew->pNext = 0;
sqlite3SelectDelete(db, pNew);
break;
}
*pp = pNew;
pp = &pNew->pPrior;
pNext = pNew;
}
return pRet;
}
#else
Select *sqlite3SelectDup(sqlite3 *db, const 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().
**
** 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.
*/
static const struct ExprList_item zeroItem = {0};
SQLITE_NOINLINE ExprList *sqlite3ExprListAppendNew(
sqlite3 *db, /* Database handle. Used for memory allocation */
Expr *pExpr /* Expression to be appended. Might be NULL */
){
struct ExprList_item *pItem;
ExprList *pList;
pList = sqlite3DbMallocRawNN(db, sizeof(ExprList)+sizeof(pList->a[0])*4 );
if( pList==0 ){
sqlite3ExprDelete(db, pExpr);
return 0;
}
pList->nAlloc = 4;
pList->nExpr = 1;
pItem = &pList->a[0];
*pItem = zeroItem;
pItem->pExpr = pExpr;
return pList;
}
SQLITE_NOINLINE ExprList *sqlite3ExprListAppendGrow(
sqlite3 *db, /* Database handle. Used for memory allocation */
ExprList *pList, /* List to which to append. Might be NULL */
Expr *pExpr /* Expression to be appended. Might be NULL */
){
struct ExprList_item *pItem;
ExprList *pNew;
pList->nAlloc *= 2;
pNew = sqlite3DbRealloc(db, pList,
sizeof(*pList)+(pList->nAlloc-1)*sizeof(pList->a[0]));
if( pNew==0 ){
sqlite3ExprListDelete(db, pList);
sqlite3ExprDelete(db, pExpr);
return 0;
}else{
pList = pNew;
}
pItem = &pList->a[pList->nExpr++];
*pItem = zeroItem;
pItem->pExpr = pExpr;
return pList;
}
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;
if( pList==0 ){
return sqlite3ExprListAppendNew(pParse->db,pExpr);
}
if( pList->nAlloc<pList->nExpr+1 ){
return sqlite3ExprListAppendGrow(pParse->db,pList,pExpr);
}
pItem = &pList->a[pList->nExpr++];
*pItem = zeroItem;
pItem->pExpr = pExpr;
return pList;
}
/*
** 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, pColumns->nId);
assert( pSubExpr!=0 || db->mallocFailed );
if( pSubExpr==0 ) continue;
pList = sqlite3ExprListAppend(pParse, pList, pSubExpr);
if( pList ){
assert( pList->nExpr==iFirst+i+1 );
pList->a[pList->nExpr-1].zEName = 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->fg.bNulls==0 );
if( iSortOrder==SQLITE_SO_UNDEFINED ){
iSortOrder = SQLITE_SO_ASC;
}
pItem->fg.sortFlags = (u8)iSortOrder;
if( eNulls!=SQLITE_SO_UNDEFINED ){
pItem->fg.bNulls = 1;
if( iSortOrder!=eNulls ){
pItem->fg.sortFlags |= KEYINFO_ORDER_BIGNULL;
}
}
}
/*
** Set the ExprList.a[].zEName 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. */
const Token *pName, /* Name to be added */
int dequote /* True to cause the name to be dequoted */
){
assert( pList!=0 || pParse->db->mallocFailed!=0 );
assert( pParse->eParseMode!=PARSE_MODE_UNMAP || dequote==0 );
if( pList ){
struct ExprList_item *pItem;
assert( pList->nExpr>0 );
pItem = &pList->a[pList->nExpr-1];
assert( pItem->zEName==0 );
assert( pItem->fg.eEName==ENAME_NAME );
pItem->zEName = sqlite3DbStrNDup(pParse->db, pName->z, pName->n);
if( dequote ){
/* If dequote==0, then pName->z does not point to part of a DDL
** statement handled by the parser. And so no token need be added
** to the token-map. */
sqlite3Dequote(pItem->zEName);
if( IN_RENAME_OBJECT ){
sqlite3RenameTokenMap(pParse, (const void*)pItem->zEName, 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 );
if( pItem->zEName==0 ){
pItem->zEName = sqlite3DbSpanDup(db, zStart, zEnd);
pItem->fg.eEName = ENAME_SPAN;
}
}
}
/*
** 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 );
assert( db!=0 );
do{
sqlite3ExprDelete(db, pItem->pExpr);
if( pItem->zEName ) sqlite3DbNNFreeNN(db, pItem->zEName);
pItem++;
}while( --i>0 );
sqlite3DbNNFreeNN(db, pList);
}
void sqlite3ExprListDelete(sqlite3 *db, ExprList *pList){
if( pList ) exprListDeleteNN(db, pList);
}
void sqlite3ExprListDeleteGeneric(sqlite3 *db, void *pList){
if( ALWAYS(pList) ) exprListDeleteNN(db, (ExprList*)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;
}
/*
** Check the input string to see if it is "true" or "false" (in any case).
**
** If the string is.... Return
** "true" EP_IsTrue
** "false" EP_IsFalse
** anything else 0
*/
u32 sqlite3IsTrueOrFalse(const char *zIn){
if( sqlite3StrICmp(zIn, "true")==0 ) return EP_IsTrue;
if( sqlite3StrICmp(zIn, "false")==0 ) return EP_IsFalse;
return 0;
}
/*
** 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){
u32 v;
assert( pExpr->op==TK_ID || pExpr->op==TK_STRING );
if( !ExprHasProperty(pExpr, EP_Quoted|EP_IntValue)
&& (v = sqlite3IsTrueOrFalse(pExpr->u.zToken))!=0
){
pExpr->op = TK_TRUEFALSE;
ExprSetProperty(pExpr, v);
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 = sqlite3ExprSkipCollateAndLikely((Expr*)pExpr);
assert( pExpr->op==TK_TRUEFALSE );
assert( !ExprHasProperty(pExpr, EP_IntValue) );
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;
}
/*
** pExpr is a TK_FUNCTION node. Try to determine whether or not the
** function is a constant function. A function is constant if all of
** the following are true:
**
** (1) It is a scalar function (not an aggregate or window function)
** (2) It has either the SQLITE_FUNC_CONSTANT or SQLITE_FUNC_SLOCHNG
** property.
** (3) All of its arguments are constants
**
** This routine sets pWalker->eCode to 0 if pExpr is not a constant.
** It makes no changes to pWalker->eCode if pExpr is constant. In
** every case, it returns WRC_Abort.
**
** Called as a service subroutine from exprNodeIsConstant().
*/
static SQLITE_NOINLINE int exprNodeIsConstantFunction(
Walker *pWalker,
Expr *pExpr
){
int n; /* Number of arguments */
ExprList *pList; /* List of arguments */
FuncDef *pDef; /* The function */
sqlite3 *db; /* The database */
assert( pExpr->op==TK_FUNCTION );
if( ExprHasProperty(pExpr, EP_TokenOnly)
|| (pList = pExpr->x.pList)==0
){;
n = 0;
}else{
n = pList->nExpr;
sqlite3WalkExprList(pWalker, pList);
if( pWalker->eCode==0 ) return WRC_Abort;
}
db = pWalker->pParse->db;
pDef = sqlite3FindFunction(db, pExpr->u.zToken, n, ENC(db), 0);
if( pDef==0
|| pDef->xFinalize!=0
|| (pDef->funcFlags & (SQLITE_FUNC_CONSTANT|SQLITE_FUNC_SLOCHNG))==0
|| ExprHasProperty(pExpr, EP_WinFunc)
){
pWalker->eCode = 0;
return WRC_Abort;
}
return WRC_Prune;
}
/*
** 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 DEFAULT
** expressions in a CREATE TABLE statement. The Walker.eCode value is 5
** when parsing an existing schema out of the sqlite_schema table and 4
** when processing a new CREATE TABLE statement. A bound parameter raises
** an error for new statements, but is silently converted
** to NULL for existing schemas. This allows sqlite_schema 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){
assert( pWalker->eCode>0 );
/* If pWalker->eCode is 2 then any term of the expression that comes from
** the ON or USING clauses of an outer join disqualifies the expression
** from being considered constant. */
if( pWalker->eCode==2 && ExprHasProperty(pExpr, EP_OuterON) ){
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))
&& !ExprHasProperty(pExpr, EP_WinFunc)
){
if( pWalker->eCode==5 ) ExprSetProperty(pExpr, EP_FromDDL);
return WRC_Continue;
}else if( pWalker->pParse ){
return exprNodeIsConstantFunction(pWalker, pExpr);
}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;
}
/* no break */ deliberate_fall_through
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;
}
/* no break */ deliberate_fall_through
case TK_IF_NULL_ROW:
case TK_REGISTER:
case TK_DOT:
case TK_RAISE:
testcase( pExpr->op==TK_REGISTER );
testcase( pExpr->op==TK_IF_NULL_ROW );
testcase( pExpr->op==TK_DOT );
testcase( pExpr->op==TK_RAISE );
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_schema 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;
}
/* no break */ deliberate_fall_through
default:
testcase( pExpr->op==TK_SELECT ); /* sqlite3SelectWalkFail() disallows */
testcase( pExpr->op==TK_EXISTS ); /* sqlite3SelectWalkFail() disallows */
return WRC_Continue;
}
}
static int exprIsConst(Parse *pParse, Expr *p, int initFlag){
Walker w;
w.eCode = initFlag;
w.pParse = pParse;
w.xExprCallback = exprNodeIsConstant;
w.xSelectCallback = sqlite3SelectWalkFail;
#ifdef SQLITE_DEBUG
w.xSelectCallback2 = sqlite3SelectWalkAssert2;
#endif
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.
**
** The pParse parameter may be NULL. But if it is NULL, there is no way
** to determine if function calls are constant or not, and hence all
** function calls will be considered to be non-constant. If pParse is
** not NULL, then a function call might be constant, depending on the
** function and on its parameters.
*/
int sqlite3ExprIsConstant(Parse *pParse, Expr *p){
return exprIsConst(pParse, p, 1);
}
/*
** 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 sqlite3ExprCodeRunJustOnce().
*/
static int sqlite3ExprIsConstantNotJoin(Parse *pParse, Expr *p){
return exprIsConst(pParse, p, 2);
}
/*
** This routine examines sub-SELECT statements as an expression is being
** walked as part of sqlite3ExprIsTableConstant(). Sub-SELECTs are considered
** constant as long as they are uncorrelated - meaning that they do not
** contain any terms from outer contexts.
*/
static int exprSelectWalkTableConstant(Walker *pWalker, Select *pSelect){
assert( pSelect!=0 );
assert( pWalker->eCode==3 || pWalker->eCode==0 );
if( (pSelect->selFlags & SF_Correlated)!=0 ){
pWalker->eCode = 0;
return WRC_Abort;
}
return WRC_Prune;
}
/*
** 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.
**
** Consider uncorrelated subqueries to be constants if the bAllowSubq
** parameter is true.
*/
static int sqlite3ExprIsTableConstant(Expr *p, int iCur, int bAllowSubq){
Walker w;
w.eCode = 3;
w.pParse = 0;
w.xExprCallback = exprNodeIsConstant;
if( bAllowSubq ){
w.xSelectCallback = exprSelectWalkTableConstant;
}else{
w.xSelectCallback = sqlite3SelectWalkFail;
#ifdef SQLITE_DEBUG
w.xSelectCallback2 = sqlite3SelectWalkAssert2;
#endif
}
w.u.iCur = iCur;
sqlite3WalkExpr(&w, p);
return w.eCode;
}
/*
** Check pExpr to see if it is an constraint on the single data source
** pSrc = &pSrcList->a[iSrc]. In other words, check to see if pExpr
** constrains pSrc but does not depend on any other tables or data
** sources anywhere else in the query. Return true (non-zero) if pExpr
** is a constraint on pSrc only.
**
** This is an optimization. False negatives will perhaps cause slower
** queries, but false positives will yield incorrect answers. So when in
** doubt, return 0.
**
** To be an single-source constraint, the following must be true:
**
** (1) pExpr cannot refer to any table other than pSrc->iCursor.
**
** (2a) pExpr cannot use subqueries unless the bAllowSubq parameter is
** true and the subquery is non-correlated
**
** (2b) pExpr cannot use non-deterministic functions.
**
** (3) pSrc cannot be part of the left operand for a RIGHT JOIN.
** (Is there some way to relax this constraint?)
**
** (4) If pSrc is the right operand of a LEFT JOIN, then...
** (4a) pExpr must come from an ON clause..
** (4b) and specifically the ON clause associated with the LEFT JOIN.
**
** (5) If pSrc is not the right operand of a LEFT JOIN or the left
** operand of a RIGHT JOIN, then pExpr must be from the WHERE
** clause, not an ON clause.
**
** (6) Either:
**
** (6a) pExpr does not originate in an ON or USING clause, or
**
** (6b) The ON or USING clause from which pExpr is derived is
** not to the left of a RIGHT JOIN (or FULL JOIN).
**
** Without this restriction, accepting pExpr as a single-table
** constraint might move the the ON/USING filter expression
** from the left side of a RIGHT JOIN over to the right side,
** which leads to incorrect answers. See also restriction (9)
** on push-down.
*/
int sqlite3ExprIsSingleTableConstraint(
Expr *pExpr, /* The constraint */
const SrcList *pSrcList, /* Complete FROM clause */
int iSrc, /* Which element of pSrcList to use */
int bAllowSubq /* Allow non-correlated subqueries */
){
const SrcItem *pSrc = &pSrcList->a[iSrc];
if( pSrc->fg.jointype & JT_LTORJ ){
return 0; /* rule (3) */
}
if( pSrc->fg.jointype & JT_LEFT ){
if( !ExprHasProperty(pExpr, EP_OuterON) ) return 0; /* rule (4a) */
if( pExpr->w.iJoin!=pSrc->iCursor ) return 0; /* rule (4b) */
}else{
if( ExprHasProperty(pExpr, EP_OuterON) ) return 0; /* rule (5) */
}
if( ExprHasProperty(pExpr, EP_OuterON|EP_InnerON) /* (6a) */
&& (pSrcList->a[0].fg.jointype & JT_LTORJ)!=0 /* Fast pre-test of (6b) */
){
int jj;
for(jj=0; jj<iSrc; jj++){
if( pExpr->w.iJoin==pSrcList->a[jj].iCursor ){
if( (pSrcList->a[jj].fg.jointype & JT_LTORJ)!=0 ){
return 0; /* restriction (6) */
}
break;
}
}
}
/* Rules (1), (2a), and (2b) handled by the following: */
return sqlite3ExprIsTableConstant(pExpr, pSrc->iCursor, bAllowSubq);
}
/*
** 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( ExprUseXSelect(pExpr) ){
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 for the DEFAULT field of a column definition
** in a CREATE TABLE statement. Return non-zero if the expression is
** acceptable for use as a DEFAULT. That is to say, return non-zero if
** the expression is constant or a function call with constant arguments.
** Return and 0 if there are any variables.
**
** isInit is true when parsing from sqlite_schema. isInit is false when
** processing a new CREATE TABLE statement. When isInit is true, parameters
** (such as ? or $abc) in the expression are converted into NULL. When
** isInit is false, parameters raise an error. Parameters should not be
** allowed in a CREATE TABLE statement, but some legacy versions of SQLite
** allowed it, so we need to support it when reading sqlite_schema for
** backwards compatibility.
**
** If isInit is true, set EP_FromDDL on every TK_FUNCTION node.
**
** 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(0, p, 4+isInit);
}
#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.
**
** If the pParse pointer is provided, then allow the expression p to be
** a parameter (TK_VARIABLE) that is bound to an integer.
** But if pParse is NULL, then p must be a pure integer literal.
*/
int sqlite3ExprIsInteger(const Expr *p, int *pValue, Parse *pParse){
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, 0);
break;
}
case TK_UMINUS: {
int v = 0;
if( sqlite3ExprIsInteger(p->pLeft, &v, 0) ){
assert( ((unsigned int)v)!=0x80000000 );
*pValue = -v;
rc = 1;
}
break;
}
case TK_VARIABLE: {
sqlite3_value *pVal;
if( pParse==0 ) break;
if( NEVER(pParse->pVdbe==0) ) break;
if( (pParse->db->flags & SQLITE_EnableQPSG)!=0 ) break;
sqlite3VdbeSetVarmask(pParse->pVdbe, p->iColumn);
pVal = sqlite3VdbeGetBoundValue(pParse->pReprepare, p->iColumn,
SQLITE_AFF_BLOB);
if( pVal ){
if( sqlite3_value_type(pVal)==SQLITE_INTEGER ){
sqlite3_int64 vv = sqlite3_value_int64(pVal);
if( vv == (vv & 0x7fffffff) ){ /* non-negative numbers only */
*pValue = (int)vv;
rc = 1;
}
}
sqlite3ValueFree(pVal);
}
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;
assert( p!=0 );
while( p->op==TK_UPLUS || p->op==TK_UMINUS ){
p = p->pLeft;
assert( p!=0 );
}
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:
assert( ExprUseYTab(p) );
return ExprHasProperty(p, EP_CanBeNull)
|| NEVER(p->y.pTab==0) /* Reference to column of index on expr */
#ifdef SQLITE_ALLOW_ROWID_IN_VIEW
|| (p->iColumn==XN_ROWID && IsView(p->y.pTab))
#endif
|| (p->iColumn>=0
&& p->y.pTab->aCol!=0 /* Possible due to prior error */
&& ALWAYS(p->iColumn<p->y.pTab->nCol)
&& 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;
}
/*
** Return a pointer to a buffer containing a usable rowid alias for table
** pTab. An alias is usable if there is not an explicit user-defined column
** of the same name.
*/
const char *sqlite3RowidAlias(Table *pTab){
const char *azOpt[] = {"_ROWID_", "ROWID", "OID"};
int ii;
assert( VisibleRowid(pTab) );
for(ii=0; ii<ArraySize(azOpt); ii++){
int iCol;
for(iCol=0; iCol<pTab->nCol; iCol++){
if( sqlite3_stricmp(azOpt[ii], pTab->aCol[iCol].zCnName)==0 ) break;
}
if( iCol==pTab->nCol ){
return azOpt[ii];
}
}
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 materialized into a transient
** table, then return NULL.
*/
#ifndef SQLITE_OMIT_SUBQUERY
static Select *isCandidateForInOpt(const Expr *pX){
Select *p;
SrcList *pSrc;
ExprList *pEList;
Table *pTab;
int i;
if( !ExprUseXSelect(pX) ) 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].fg.isSubquery) return 0;/* FROM is not a subquery or view */
pTab = pSrc->a[0].pSTab;
assert( pTab!=0 );
assert( !IsView(pTab) ); /* 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(Parse *pParse, Expr *pIn){
Expr *pLHS;
int res;
assert( !ExprHasProperty(pIn, EP_xIsSelect) );
pLHS = pIn->pLeft;
pIn->pLeft = 0;
res = sqlite3ExprIsConstant(pParse, 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 the *piTab parameter 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 ephemeral 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. In this case, the creation and initialization of the
** ephemeral table might be put inside of a subroutine, the EP_Subrtn flag
** will be set on pX and the pX->y.sub fields will be set to show where
** the subroutine is coded.
**
** 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 ephemeral 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 ephemeral 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; /* 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;
iTab = pParse->nTab++;
/* 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 && ExprUseXSelect(pX) ){
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>. */
int 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].pSTab;
/* Code an OP_Transaction and OP_TableLock for <table>. */
iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
assert( iDb>=0 && iDb<SQLITE_MAX_DB );
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;
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)
&& ExprUseXList(pX)
&& (!sqlite3InRhsIsConstant(pParse,pX) || pX->x.pList->nExpr<=2)
){
pParse->nTab--; /* Back out the allocation of the unused cursor */
iTab = -1; /* Cursor is not allocated */
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, const Expr *pExpr){
Expr *pLeft = pExpr->pLeft;
int nVal = sqlite3ExprVectorSize(pLeft);
Select *pSelect = ExprUseXSelect(pExpr) ? 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
/*
** Load the Parse object passed as the first argument with an error
** message of the form:
**
** "sub-select returns N columns - expected M"
*/
void sqlite3SubselectError(Parse *pParse, int nActual, int nExpect){
if( pParse->nErr==0 ){
const char *zFmt = "sub-select returns %d columns - expected %d";
sqlite3ErrorMsg(pParse, zFmt, nActual, nExpect);
}
}
#endif
/*
** Expression pExpr is a vector that has been used in a context where
** it is not permitted. If pExpr is a sub-select vector, this routine
** loads the Parse object with a message of the form:
**
** "sub-select returns N columns - expected 1"
**
** Or, if it is a regular scalar vector:
**
** "row value misused"
*/
void sqlite3VectorErrorMsg(Parse *pParse, Expr *pExpr){
#ifndef SQLITE_OMIT_SUBQUERY
if( ExprUseXSelect(pExpr) ){
sqlite3SubselectError(pParse, pExpr->x.pSelect->pEList->nExpr, 1);
}else
#endif
{
sqlite3ErrorMsg(pParse, "row value misused");
}
}
#ifndef SQLITE_OMIT_SUBQUERY
/*
** Scan all previously generated bytecode looking for an OP_BeginSubrtn
** that is compatible with pExpr. If found, add the y.sub values
** to pExpr and return true. If not found, return false.
*/
static int findCompatibleInRhsSubrtn(
Parse *pParse, /* Parsing context */
Expr *pExpr, /* IN operator with RHS that we want to reuse */
SubrtnSig *pNewSig /* Signature for the IN operator */
){
VdbeOp *pOp, *pEnd;
SubrtnSig *pSig;
Vdbe *v;
if( pNewSig==0 ) return 0;
if( (pParse->mSubrtnSig & (1<<(pNewSig->selId&7)))==0 ) return 0;
assert( pExpr->op==TK_IN );
assert( !ExprUseYSub(pExpr) );
assert( ExprUseXSelect(pExpr) );
assert( pExpr->x.pSelect!=0 );
assert( (pExpr->x.pSelect->selFlags & SF_All)==0 );
v = pParse->pVdbe;
assert( v!=0 );
pOp = sqlite3VdbeGetOp(v, 1);
pEnd = sqlite3VdbeGetLastOp(v);
for(; pOp<pEnd; pOp++){
if( pOp->p4type!=P4_SUBRTNSIG ) continue;
assert( pOp->opcode==OP_BeginSubrtn );
pSig = pOp->p4.pSubrtnSig;
assert( pSig!=0 );
if( pNewSig->selId!=pSig->selId ) continue;
if( strcmp(pNewSig->zAff,pSig->zAff)!=0 ) continue;
pExpr->y.sub.iAddr = pSig->iAddr;
pExpr->y.sub.regReturn = pSig->regReturn;
pExpr->iTable = pSig->iTable;
ExprSetProperty(pExpr, EP_Subrtn);
return 1;
}
return 0;
}
#endif /* SQLITE_OMIT_SUBQUERY */
#ifndef SQLITE_OMIT_SUBQUERY
/*
** Generate code that will construct an ephemeral table containing all terms
** in the RHS of an IN operator. The IN operator can be in either of two
** forms:
**
** x IN (4,5,11) -- IN operator with list on right-hand side
** x IN (SELECT a FROM b) -- IN operator with subquery on the right
**
** The pExpr parameter is the IN operator. The cursor number for the
** constructed ephemeral table is returned. The first time the ephemeral
** table is computed, the cursor number is also stored in pExpr->iTable,
** however the cursor number returned might not be the same, as it might
** have been duplicated using OP_OpenDup.
**
** If the LHS expression ("x" in the examples) is a column value, or
** the SELECT statement returns a column value, then the affinity of that
** column is used to build the index keys. If both 'x' and the
** SELECT... statement are columns, then numeric affinity is used
** if either column has NUMERIC or INTEGER affinity. If neither
** 'x' nor the SELECT... statement are columns, then numeric affinity
** is used.
*/
void sqlite3CodeRhsOfIN(
Parse *pParse, /* Parsing context */
Expr *pExpr, /* The IN operator */
int iTab /* Use this cursor number */
){
int addrOnce = 0; /* Address of the OP_Once instruction at top */
int addr; /* Address of OP_OpenEphemeral instruction */
Expr *pLeft; /* the LHS of the IN operator */
KeyInfo *pKeyInfo = 0; /* Key information */
int nVal; /* Size of vector pLeft */
Vdbe *v; /* The prepared statement under construction */
v = pParse->pVdbe;
assert( v!=0 );
/* The evaluation of the IN must be repeated every time it
** is encountered if any of the following is true:
**
** * The right-hand side is a correlated subquery
** * The right-hand side is an expression list containing variables
** * We are inside a trigger
**
** If all of the above are false, then we can compute the RHS just once
** and reuse it many names.
*/
if( !ExprHasProperty(pExpr, EP_VarSelect) && pParse->iSelfTab==0 ){
/* Reuse of the RHS is allowed
**
** Compute a signature for the RHS of the IN operator to facility
** finding and reusing prior instances of the same IN operator.
*/
SubrtnSig *pSig = 0;
assert( !ExprUseXSelect(pExpr) || pExpr->x.pSelect!=0 );
if( ExprUseXSelect(pExpr) && (pExpr->x.pSelect->selFlags & SF_All)==0 ){
pSig = sqlite3DbMallocRawNN(pParse->db, sizeof(pSig[0]));
if( pSig ){
pSig->selId = pExpr->x.pSelect->selId;
pSig->zAff = exprINAffinity(pParse, pExpr);
}
}
/* Check to see if there is a prior materialization of the RHS of
** this IN operator. If there is, then make use of that prior
** materialization rather than recomputing it.
*/
if( ExprHasProperty(pExpr, EP_Subrtn)
|| findCompatibleInRhsSubrtn(pParse, pExpr, pSig)
){
addrOnce = sqlite3VdbeAddOp0(v, OP_Once); VdbeCoverage(v);
if( ExprUseXSelect(pExpr) ){
ExplainQueryPlan((pParse, 0, "REUSE LIST SUBQUERY %d",
pExpr->x.pSelect->selId));
}
assert( ExprUseYSub(pExpr) );
sqlite3VdbeAddOp2(v, OP_Gosub, pExpr->y.sub.regReturn,
pExpr->y.sub.iAddr);
assert( iTab!=pExpr->iTable );
sqlite3VdbeAddOp2(v, OP_OpenDup, iTab, pExpr->iTable);
sqlite3VdbeJumpHere(v, addrOnce);
if( pSig ){
sqlite3DbFree(pParse->db, pSig->zAff);
sqlite3DbFree(pParse->db, pSig);
}
return;
}
/* Begin coding the subroutine */
assert( !ExprUseYWin(pExpr) );
ExprSetProperty(pExpr, EP_Subrtn);
assert( !ExprHasProperty(pExpr, EP_TokenOnly|EP_Reduced) );
pExpr->y.sub.regReturn = ++pParse->nMem;
pExpr->y.sub.iAddr =
sqlite3VdbeAddOp2(v, OP_BeginSubrtn, 0, pExpr->y.sub.regReturn) + 1;
if( pSig ){
pSig->iAddr = pExpr->y.sub.iAddr;
pSig->regReturn = pExpr->y.sub.regReturn;
pSig->iTable = iTab;
pParse->mSubrtnSig = 1 << (pSig->selId&7);
sqlite3VdbeChangeP4(v, -1, (const char*)pSig, P4_SUBRTNSIG);
}
addrOnce = sqlite3VdbeAddOp0(v, OP_Once); VdbeCoverage(v);
}
/* Check to see if this is a vector IN operator */
pLeft = pExpr->pLeft;
nVal = sqlite3ExprVectorSize(pLeft);
/* Construct the ephemeral table that will contain the content of
** RHS of the IN operator.
*/
pExpr->iTable = iTab;
addr = sqlite3VdbeAddOp2(v, OP_OpenEphemeral, pExpr->iTable, nVal);
#ifdef SQLITE_ENABLE_EXPLAIN_COMMENTS
if( ExprUseXSelect(pExpr) ){
VdbeComment((v, "Result of SELECT %u", pExpr->x.pSelect->selId));
}else{
VdbeComment((v, "RHS of IN operator"));
}
#endif
pKeyInfo = sqlite3KeyInfoAlloc(pParse->db, nVal, 1);
if( ExprUseXSelect(pExpr) ){
/* Case 1: expr IN (SELECT ...)
**
** Generate code to write the results of the select into the temporary
** table allocated and opened above.
*/
Select *pSelect = pExpr->x.pSelect;
ExprList *pEList = pSelect->pEList;
ExplainQueryPlan((pParse, 1, "%sLIST SUBQUERY %d",
addrOnce?"":"CORRELATED ", pSelect->selId
));
/* If the LHS and RHS of the IN operator do not match, that
** error will have been caught long before we reach this point. */
if( ALWAYS(pEList->nExpr==nVal) ){
Select *pCopy;
SelectDest dest;
int i;
int rc;
int addrBloom = 0;
sqlite3SelectDestInit(&dest, SRT_Set, iTab);
dest.zAffSdst = exprINAffinity(pParse, pExpr);
pSelect->iLimit = 0;
if( addrOnce && OptimizationEnabled(pParse->db, SQLITE_BloomFilter) ){
int regBloom = ++pParse->nMem;
addrBloom = sqlite3VdbeAddOp2(v, OP_Blob, 10000, regBloom);
VdbeComment((v, "Bloom filter"));
dest.iSDParm2 = regBloom;
}
testcase( pSelect->selFlags & SF_Distinct );
testcase( pKeyInfo==0 ); /* Caused by OOM in sqlite3KeyInfoAlloc() */
pCopy = sqlite3SelectDup(pParse->db, pSelect, 0);
rc = pParse->db->mallocFailed ? 1 :sqlite3Select(pParse, pCopy, &dest);
sqlite3SelectDelete(pParse->db, pCopy);
sqlite3DbFree(pParse->db, dest.zAffSdst);
if( addrBloom ){
sqlite3VdbeGetOp(v, addrOnce)->p3 = dest.iSDParm2;
if( dest.iSDParm2==0 ){
sqlite3VdbeChangeToNoop(v, addrBloom);
}else{
sqlite3VdbeGetOp(v, addrOnce)->p3 = dest.iSDParm2;
}
}
if( rc ){
sqlite3KeyInfoUnref(pKeyInfo);
return;
}
assert( pKeyInfo!=0 ); /* OOM will cause exit after sqlite3Select() */
assert( pEList!=0 );
assert( pEList->nExpr>0 );
assert( sqlite3KeyInfoIsWriteable(pKeyInfo) );
for(i=0; i<nVal; i++){
Expr *p = sqlite3VectorFieldSubexpr(pLeft, i);
pKeyInfo->aColl[i] = sqlite3BinaryCompareCollSeq(
pParse, p, pEList->a[i].pExpr
);
}
}
}else if( ALWAYS(pExpr->x.pList!=0) ){
/* Case 2: expr IN (exprlist)
**
** For each expression, build an index key from the evaluation and
** store it in the temporary table. If <expr> is a column, then use
** that columns affinity when building index keys. If <expr> is not
** a column, use numeric affinity.
*/
char affinity; /* Affinity of the LHS of the IN */
int i;
ExprList *pList = pExpr->x.pList;
struct ExprList_item *pItem;
int r1, r2;
affinity = sqlite3ExprAffinity(pLeft);
if( affinity<=SQLITE_AFF_NONE ){
affinity = SQLITE_AFF_BLOB;
}else if( affinity==SQLITE_AFF_REAL ){
affinity = SQLITE_AFF_NUMERIC;
}
if( pKeyInfo ){
assert( sqlite3KeyInfoIsWriteable(pKeyInfo) );
pKeyInfo->aColl[0] = sqlite3ExprCollSeq(pParse, pExpr->pLeft);
}
/* Loop through each expression in <exprlist>. */
r1 = sqlite3GetTempReg(pParse);
r2 = sqlite3GetTempReg(pParse);
for(i=pList->nExpr, pItem=pList->a; i>0; i--, pItem++){
Expr *pE2 = pItem->pExpr;
/* If the expression is not constant then we will need to
** disable the test that was generated above that makes sure
** this code only executes once. Because for a non-constant
** expression we need to rerun this code each time.
*/
if( addrOnce && !sqlite3ExprIsConstant(pParse, pE2) ){
sqlite3VdbeChangeToNoop(v, addrOnce-1);
sqlite3VdbeChangeToNoop(v, addrOnce);
ExprClearProperty(pExpr, EP_Subrtn);
addrOnce = 0;
}
/* Evaluate the expression and insert it into the temp table */
sqlite3ExprCode(pParse, pE2, r1);
sqlite3VdbeAddOp4(v, OP_MakeRecord, r1, 1, r2, &affinity, 1);
sqlite3VdbeAddOp4Int(v, OP_IdxInsert, iTab, r2, r1, 1);
}
sqlite3ReleaseTempReg(pParse, r1);
sqlite3ReleaseTempReg(pParse, r2);
}
if( pKeyInfo ){
sqlite3VdbeChangeP4(v, addr, (void *)pKeyInfo, P4_KEYINFO);
}
if( addrOnce ){
sqlite3VdbeAddOp1(v, OP_NullRow, iTab);
sqlite3VdbeJumpHere(v, addrOnce);
/* Subroutine return */
assert( ExprUseYSub(pExpr) );
assert( sqlite3VdbeGetOp(v,pExpr->y.sub.iAddr-1)->opcode==OP_BeginSubrtn
|| pParse->nErr );
sqlite3VdbeAddOp3(v, OP_Return, pExpr->y.sub.regReturn,
pExpr->y.sub.iAddr, 1);
VdbeCoverage(v);
sqlite3ClearTempRegCache(pParse);
}
}
#endif /* SQLITE_OMIT_SUBQUERY */
/*
** Generate code for scalar subqueries used as a subquery expression
** or EXISTS operator:
**
** (SELECT a FROM b) -- subquery
** EXISTS (SELECT a FROM b) -- EXISTS subquery
**
** The pExpr parameter is the SELECT or EXISTS operator to be coded.
**
** Return the register that holds the result. For a multi-column SELECT,
** the result is stored in a contiguous array of registers and the
** return value is the register of the left-most result column.
** Return 0 if an error occurs.
*/
#ifndef SQLITE_OMIT_SUBQUERY
int sqlite3CodeSubselect(Parse *pParse, Expr *pExpr){
int addrOnce = 0; /* Address of OP_Once at top of subroutine */
int rReg = 0; /* Register storing resulting */
Select *pSel; /* SELECT statement to encode */
SelectDest dest; /* How to deal with SELECT result */
int nReg; /* Registers to allocate */
Expr *pLimit; /* New limit expression */
#ifdef SQLITE_ENABLE_STMT_SCANSTATUS
int addrExplain; /* Address of OP_Explain instruction */
#endif
Vdbe *v = pParse->pVdbe;
assert( v!=0 );
if( pParse->nErr ) return 0;
testcase( pExpr->op==TK_EXISTS );
testcase( pExpr->op==TK_SELECT );
assert( pExpr->op==TK_EXISTS || pExpr->op==TK_SELECT );
assert( ExprUseXSelect(pExpr) );
pSel = pExpr->x.pSelect;
/* If this routine has already been coded, then invoke it as a
** subroutine. */
if( ExprHasProperty(pExpr, EP_Subrtn) ){
ExplainQueryPlan((pParse, 0, "REUSE SUBQUERY %d", pSel->selId));
assert( ExprUseYSub(pExpr) );
sqlite3VdbeAddOp2(v, OP_Gosub, pExpr->y.sub.regReturn,
pExpr->y.sub.iAddr);
return pExpr->iTable;
}
/* Begin coding the subroutine */
assert( !ExprUseYWin(pExpr) );
assert( !ExprHasProperty(pExpr, EP_Reduced|EP_TokenOnly) );
ExprSetProperty(pExpr, EP_Subrtn);
pExpr->y.sub.regReturn = ++pParse->nMem;
pExpr->y.sub.iAddr =
sqlite3VdbeAddOp2(v, OP_BeginSubrtn, 0, pExpr->y.sub.regReturn) + 1;
/* The evaluation of the EXISTS/SELECT must be repeated every time it
** is encountered if any of the following is true:
**
** * The right-hand side is a correlated subquery
** * The right-hand side is an expression list containing variables
** * We are inside a trigger
**
** If all of the above are false, then we can run this code just once
** save the results, and reuse the same result on subsequent invocations.
*/
if( !ExprHasProperty(pExpr, EP_VarSelect) ){
addrOnce = sqlite3VdbeAddOp0(v, OP_Once); VdbeCoverage(v);
}
/* For a SELECT, generate code to put the values for all columns of
** the first row into an array of registers and return the index of
** the first register.
**
** If this is an EXISTS, write an integer 0 (not exists) or 1 (exists)
** into a register and return that register number.
**
** In both cases, the query is augmented with "LIMIT 1". Any
** preexisting limit is discarded in place of the new LIMIT 1.
*/
ExplainQueryPlan2(addrExplain, (pParse, 1, "%sSCALAR SUBQUERY %d",
addrOnce?"":"CORRELATED ", pSel->selId));
sqlite3VdbeScanStatusCounters(v, addrExplain, addrExplain, -1);
nReg = pExpr->op==TK_SELECT ? pSel->pEList->nExpr : 1;
sqlite3SelectDestInit(&dest, 0, pParse->nMem+1);
pParse->nMem += nReg;
if( pExpr->op==TK_SELECT ){
dest.eDest = SRT_Mem;
dest.iSdst = dest.iSDParm;
dest.nSdst = nReg;
sqlite3VdbeAddOp3(v, OP_Null, 0, dest.iSDParm, dest.iSDParm+nReg-1);
VdbeComment((v, "Init subquery result"));
}else{
dest.eDest = SRT_Exists;
sqlite3VdbeAddOp2(v, OP_Integer, 0, dest.iSDParm);
VdbeComment((v, "Init EXISTS result"));
}
if( pSel->pLimit ){
/* The subquery already has a limit. If the pre-existing limit is X
** then make the new limit X<>0 so that the new limit is either 1 or 0 */
sqlite3 *db = pParse->db;
pLimit = sqlite3Expr(db, TK_INTEGER, "0");
if( pLimit ){
pLimit->affExpr = SQLITE_AFF_NUMERIC;
pLimit = sqlite3PExpr(pParse, TK_NE,
sqlite3ExprDup(db, pSel->pLimit->pLeft, 0), pLimit);
}
sqlite3ExprDeferredDelete(pParse, pSel->pLimit->pLeft);
pSel->pLimit->pLeft = pLimit;
}else{
/* If there is no pre-existing limit add a limit of 1 */
pLimit = sqlite3Expr(pParse->db, TK_INTEGER, "1");
pSel->pLimit = sqlite3PExpr(pParse, TK_LIMIT, pLimit, 0);
}
pSel->iLimit = 0;
if( sqlite3Select(pParse, pSel, &dest) ){
pExpr->op2 = pExpr->op;
pExpr->op = TK_ERROR;
return 0;
}
pExpr->iTable = rReg = dest.iSDParm;
ExprSetVVAProperty(pExpr, EP_NoReduce);
if( addrOnce ){
sqlite3VdbeJumpHere(v, addrOnce);
}
sqlite3VdbeScanStatusRange(v, addrExplain, addrExplain, -1);
/* Subroutine return */
assert( ExprUseYSub(pExpr) );
assert( sqlite3VdbeGetOp(v,pExpr->y.sub.iAddr-1)->opcode==OP_BeginSubrtn
|| pParse->nErr );
sqlite3VdbeAddOp3(v, OP_Return, pExpr->y.sub.regReturn,
pExpr->y.sub.iAddr, 1);
VdbeCoverage(v);
sqlite3ClearTempRegCache(pParse);
return rReg;
}
#endif /* SQLITE_OMIT_SUBQUERY */
#ifndef SQLITE_OMIT_SUBQUERY
/*
** Expr pIn is an IN(...) expression. This function checks that the
** sub-select on the RHS of the IN() operator has the same number of
** columns as the vector on the LHS. Or, if the RHS of the IN() is not
** a sub-query, that the LHS is a vector of size 1.
*/
int sqlite3ExprCheckIN(Parse *pParse, Expr *pIn){
int nVector = sqlite3ExprVectorSize(pIn->pLeft);
if( ExprUseXSelect(pIn) && !pParse->db->mallocFailed ){
if( nVector!=pIn->x.pSelect->pEList->nExpr ){
sqlite3SubselectError(pParse, pIn->x.pSelect->pEList->nExpr, nVector);
return 1;
}
}else if( nVector!=1 ){
sqlite3VectorErrorMsg(pParse, pIn->pLeft);
return 1;
}
return 0;
}
#endif
#ifndef SQLITE_OMIT_SUBQUERY
/*
** Generate code for an IN expression.
**
** x IN (SELECT ...)
** x IN (value, value, ...)
**
** The left-hand side (LHS) is a scalar or vector expression. The
** right-hand side (RHS) is an array of zero or more scalar values, or a
** subquery. If the RHS is a subquery, the number of result columns must
** match the number of columns in the vector on the LHS. If the RHS is
** a list of values, the LHS must be a scalar.
**
** The IN operator is true if the LHS value is contained within the RHS.
** The result is false if the LHS is definitely not in the RHS. The
** result is NULL if the presence of the LHS in the RHS cannot be
** determined due to NULLs.
**
** This routine generates code that jumps to destIfFalse if the LHS is not
** contained within the RHS. If due to NULLs we cannot determine if the LHS
** is contained in the RHS then jump to destIfNull. If the LHS is contained
** within the RHS then fall through.
**
** See the separate in-operator.md documentation file in the canonical
** SQLite source tree for additional information.
*/
static void sqlite3ExprCodeIN(
Parse *pParse, /* Parsing and code generating context */
Expr *pExpr, /* The IN expression */
int destIfFalse, /* Jump here if LHS is not contained in the RHS */
int destIfNull /* Jump here if the results are unknown due to NULLs */
){
int rRhsHasNull = 0; /* Register that is true if RHS contains NULL values */
int eType; /* Type of the RHS */
int rLhs; /* Register(s) holding the LHS values */
int rLhsOrig; /* LHS values prior to reordering by aiMap[] */
Vdbe *v; /* Statement under construction */
int *aiMap = 0; /* Map from vector field to index column */
char *zAff = 0; /* Affinity string for comparisons */
int nVector; /* Size of vectors for this IN operator */
int iDummy; /* Dummy parameter to exprCodeVector() */
Expr *pLeft; /* The LHS of the IN operator */
int i; /* loop counter */
int destStep2; /* Where to jump when NULLs seen in step 2 */
int destStep6 = 0; /* Start of code for Step 6 */
int addrTruthOp; /* Address of opcode that determines the IN is true */
int destNotNull; /* Jump here if a comparison is not true in step 6 */
int addrTop; /* Top of the step-6 loop */
int iTab = 0; /* Index to use */
u8 okConstFactor = pParse->okConstFactor;
assert( !ExprHasVVAProperty(pExpr,EP_Immutable) );
pLeft = pExpr->pLeft;
if( sqlite3ExprCheckIN(pParse, pExpr) ) return;
zAff = exprINAffinity(pParse, pExpr);
nVector = sqlite3ExprVectorSize(pExpr->pLeft);
aiMap = (int*)sqlite3DbMallocZero(pParse->db, nVector*sizeof(int));
if( pParse->db->mallocFailed ) goto sqlite3ExprCodeIN_oom_error;
/* Attempt to compute the RHS. After this step, if anything other than
** IN_INDEX_NOOP is returned, the table opened with cursor iTab
** contains the values that make up the RHS. If IN_INDEX_NOOP is returned,
** the RHS has not yet been coded. */
v = pParse->pVdbe;
assert( v!=0 ); /* OOM detected prior to this routine */
VdbeNoopComment((v, "begin IN expr"));
eType = sqlite3FindInIndex(pParse, pExpr,
IN_INDEX_MEMBERSHIP | IN_INDEX_NOOP_OK,
destIfFalse==destIfNull ? 0 : &rRhsHasNull,
aiMap, &iTab);
assert( pParse->nErr || nVector==1 || eType==IN_INDEX_EPH
|| eType==IN_INDEX_INDEX_ASC || eType==IN_INDEX_INDEX_DESC
);
#ifdef SQLITE_DEBUG
/* Confirm that aiMap[] contains nVector integer values between 0 and
** nVector-1. */
for(i=0; i<nVector; i++){
int j, cnt;
for(cnt=j=0; j<nVector; j++) if( aiMap[j]==i ) cnt++;
assert( cnt==1 );
}
#endif
/* Code the LHS, the <expr> from "<expr> IN (...)". If the LHS is a
** vector, then it is stored in an array of nVector registers starting
** at r1.
**
** sqlite3FindInIndex() might have reordered the fields of the LHS vector
** so that the fields are in the same order as an existing index. The
** aiMap[] array contains a mapping from the original LHS field order to
** the field order that matches the RHS index.
**
** Avoid factoring the LHS of the IN(...) expression out of the loop,
** even if it is constant, as OP_Affinity may be used on the register
** by code generated below. */
assert( pParse->okConstFactor==okConstFactor );
pParse->okConstFactor = 0;
rLhsOrig = exprCodeVector(pParse, pLeft, &iDummy);
pParse->okConstFactor = okConstFactor;
for(i=0; i<nVector && aiMap[i]==i; i++){} /* Are LHS fields reordered? */
if( i==nVector ){
/* LHS fields are not reordered */
rLhs = rLhsOrig;
}else{
/* Need to reorder the LHS fields according to aiMap */
rLhs = sqlite3GetTempRange(pParse, nVector);
for(i=0; i<nVector; i++){
sqlite3VdbeAddOp3(v, OP_Copy, rLhsOrig+i, rLhs+aiMap[i], 0);
}
}
/* If sqlite3FindInIndex() did not find or create an index that is
** suitable for evaluating the IN operator, then evaluate using a
** sequence of comparisons.
**
** This is step (1) in the in-operator.md optimized algorithm.
*/
if( eType==IN_INDEX_NOOP ){
ExprList *pList;
CollSeq *pColl;
int labelOk = sqlite3VdbeMakeLabel(pParse);
int r2, regToFree;
int regCkNull = 0;
int ii;
assert( ExprUseXList(pExpr) );
pList = pExpr->x.pList;
pColl = sqlite3ExprCollSeq(pParse, pExpr->pLeft);
if( destIfNull!=destIfFalse ){
regCkNull = sqlite3GetTempReg(pParse);
sqlite3VdbeAddOp3(v, OP_BitAnd, rLhs, rLhs, regCkNull);
}
for(ii=0; ii<pList->nExpr; ii++){
r2 = sqlite3ExprCodeTemp(pParse, pList->a[ii].pExpr, &regToFree);
if( regCkNull && sqlite3ExprCanBeNull(pList->a[ii].pExpr) ){
sqlite3VdbeAddOp3(v, OP_BitAnd, regCkNull, r2, regCkNull);
}
sqlite3ReleaseTempReg(pParse, regToFree);
if( ii<pList->nExpr-1 || destIfNull!=destIfFalse ){
int op = rLhs!=r2 ? OP_Eq : OP_NotNull;
sqlite3VdbeAddOp4(v, op, rLhs, labelOk, r2,
(void*)pColl, P4_COLLSEQ);
VdbeCoverageIf(v, ii<pList->nExpr-1 && op==OP_Eq);
VdbeCoverageIf(v, ii==pList->nExpr-1 && op==OP_Eq);
VdbeCoverageIf(v, ii<pList->nExpr-1 && op==OP_NotNull);
VdbeCoverageIf(v, ii==pList->nExpr-1 && op==OP_NotNull);
sqlite3VdbeChangeP5(v, zAff[0]);
}else{
int op = rLhs!=r2 ? OP_Ne : OP_IsNull;
assert( destIfNull==destIfFalse );
sqlite3VdbeAddOp4(v, op, rLhs, destIfFalse, r2,
(void*)pColl, P4_COLLSEQ);
VdbeCoverageIf(v, op==OP_Ne);
VdbeCoverageIf(v, op==OP_IsNull);
sqlite3VdbeChangeP5(v, zAff[0] | SQLITE_JUMPIFNULL);
}
}
if( regCkNull ){
sqlite3VdbeAddOp2(v, OP_IsNull, regCkNull, destIfNull); VdbeCoverage(v);
sqlite3VdbeGoto(v, destIfFalse);
}
sqlite3VdbeResolveLabel(v, labelOk);
sqlite3ReleaseTempReg(pParse, regCkNull);
goto sqlite3ExprCodeIN_finished;
}
/* Step 2: Check to see if the LHS contains any NULL columns. If the
** LHS does contain NULLs then the result must be either FALSE or NULL.
** We will then skip the binary search of the RHS.
*/
if( destIfNull==destIfFalse ){
destStep2 = destIfFalse;
}else{
destStep2 = destStep6 = sqlite3VdbeMakeLabel(pParse);
}
for(i=0; i<nVector; i++){
Expr *p = sqlite3VectorFieldSubexpr(pExpr->pLeft, i);
if( pParse->nErr ) goto sqlite3ExprCodeIN_oom_error;
if( sqlite3ExprCanBeNull(p) ){
sqlite3VdbeAddOp2(v, OP_IsNull, rLhs+i, destStep2);
VdbeCoverage(v);
}
}
/* Step 3. The LHS is now known to be non-NULL. Do the binary search
** of the RHS using the LHS as a probe. If found, the result is
** true.
*/
if( eType==IN_INDEX_ROWID ){
/* In this case, the RHS is the ROWID of table b-tree and so we also
** know that the RHS is non-NULL. Hence, we combine steps 3 and 4
** into a single opcode. */
sqlite3VdbeAddOp3(v, OP_SeekRowid, iTab, destIfFalse, rLhs);
VdbeCoverage(v);
addrTruthOp = sqlite3VdbeAddOp0(v, OP_Goto); /* Return True */
}else{
sqlite3VdbeAddOp4(v, OP_Affinity, rLhs, nVector, 0, zAff, nVector);
if( destIfFalse==destIfNull ){
/* Combine Step 3 and Step 5 into a single opcode */
if( ExprHasProperty(pExpr, EP_Subrtn) ){
const VdbeOp *pOp = sqlite3VdbeGetOp(v, pExpr->y.sub.iAddr);
assert( pOp->opcode==OP_Once || pParse->nErr );
if( pOp->opcode==OP_Once && pOp->p3>0 ){
assert( OptimizationEnabled(pParse->db, SQLITE_BloomFilter) );
sqlite3VdbeAddOp4Int(v, OP_Filter, pOp->p3, destIfFalse,
rLhs, nVector); VdbeCoverage(v);
}
}
sqlite3VdbeAddOp4Int(v, OP_NotFound, iTab, destIfFalse,
rLhs, nVector); VdbeCoverage(v);
goto sqlite3ExprCodeIN_finished;
}
/* Ordinary Step 3, for the case where FALSE and NULL are distinct */
addrTruthOp = sqlite3VdbeAddOp4Int(v, OP_Found, iTab, 0,
rLhs, nVector); VdbeCoverage(v);
}
/* Step 4. If the RHS is known to be non-NULL and we did not find
** an match on the search above, then the result must be FALSE.
*/
if( rRhsHasNull && nVector==1 ){
sqlite3VdbeAddOp2(v, OP_NotNull, rRhsHasNull, destIfFalse);
VdbeCoverage(v);
}
/* Step 5. If we do not care about the difference between NULL and
** FALSE, then just return false.
*/
if( destIfFalse==destIfNull ) sqlite3VdbeGoto(v, destIfFalse);
/* Step 6: Loop through rows of the RHS. Compare each row to the LHS.
** If any comparison is NULL, then the result is NULL. If all
** comparisons are FALSE then the final result is FALSE.
**
** For a scalar LHS, it is sufficient to check just the first row
** of the RHS.
*/
if( destStep6 ) sqlite3VdbeResolveLabel(v, destStep6);
addrTop = sqlite3VdbeAddOp2(v, OP_Rewind, iTab, destIfFalse);
VdbeCoverage(v);
if( nVector>1 ){
destNotNull = sqlite3VdbeMakeLabel(pParse);
}else{
/* For nVector==1, combine steps 6 and 7 by immediately returning
** FALSE if the first comparison is not NULL */
destNotNull = destIfFalse;
}
for(i=0; i<nVector; i++){
Expr *p;
CollSeq *pColl;
int r3 = sqlite3GetTempReg(pParse);
p = sqlite3VectorFieldSubexpr(pLeft, i);
pColl = sqlite3ExprCollSeq(pParse, p);
sqlite3VdbeAddOp3(v, OP_Column, iTab, i, r3);
sqlite3VdbeAddOp4(v, OP_Ne, rLhs+i, destNotNull, r3,
(void*)pColl, P4_COLLSEQ);
VdbeCoverage(v);
sqlite3ReleaseTempReg(pParse, r3);
}
sqlite3VdbeAddOp2(v, OP_Goto, 0, destIfNull);
if( nVector>1 ){
sqlite3VdbeResolveLabel(v, destNotNull);
sqlite3VdbeAddOp2(v, OP_Next, iTab, addrTop+1);
VdbeCoverage(v);
/* Step 7: If we reach this point, we know that the result must
** be false. */
sqlite3VdbeAddOp2(v, OP_Goto, 0, destIfFalse);
}
/* Jumps here in order to return true. */
sqlite3VdbeJumpHere(v, addrTruthOp);
sqlite3ExprCodeIN_finished:
if( rLhs!=rLhsOrig ) sqlite3ReleaseTempReg(pParse, rLhs);
VdbeComment((v, "end IN expr"));
sqlite3ExprCodeIN_oom_error:
sqlite3DbFree(pParse->db, aiMap);
sqlite3DbFree(pParse->db, zAff);
}
#endif /* SQLITE_OMIT_SUBQUERY */
#ifndef SQLITE_OMIT_FLOATING_POINT
/*
** Generate an instruction that will put the floating point
** value described by z[0..n-1] into register iMem.
**
** The z[] string will probably not be zero-terminated. But the
** z[n] character is guaranteed to be something that does not look
** like the continuation of the number.
*/
static void codeReal(Vdbe *v, const char *z, int negateFlag, int iMem){
if( ALWAYS(z!=0) ){
double value;
sqlite3AtoF(z, &value, sqlite3Strlen30(z), SQLITE_UTF8);
assert( !sqlite3IsNaN(value) ); /* The new AtoF never returns NaN */
if( negateFlag ) value = -value;
sqlite3VdbeAddOp4Dup8(v, OP_Real, 0, iMem, 0, (u8*)&value, P4_REAL);
}
}
#endif
/*
** Generate an instruction that will put the integer describe by
** text z[0..n-1] into register iMem.
**
** Expr.u.zToken is always UTF8 and zero-terminated.
*/
static void codeInteger(Parse *pParse, Expr *pExpr, int negFlag, int iMem){
Vdbe *v = pParse->pVdbe;
if( pExpr->flags & EP_IntValue ){
int i = pExpr->u.iValue;
assert( i>=0 );
if( negFlag ) i = -i;
sqlite3VdbeAddOp2(v, OP_Integer, i, iMem);
}else{
int c;
i64 value;
const char *z = pExpr->u.zToken;
assert( z!=0 );
c = sqlite3DecOrHexToI64(z, &value);
if( (c==3 && !negFlag) || (c==2) || (negFlag && value==SMALLEST_INT64)){
#ifdef SQLITE_OMIT_FLOATING_POINT
sqlite3ErrorMsg(pParse, "oversized integer: %s%#T", negFlag?"-":"",pExpr);
#else
#ifndef SQLITE_OMIT_HEX_INTEGER
if( sqlite3_strnicmp(z,"0x",2)==0 ){
sqlite3ErrorMsg(pParse, "hex literal too big: %s%#T",
negFlag?"-":"",pExpr);
}else
#endif
{
codeReal(v, z, negFlag, iMem);
}
#endif
}else{
if( negFlag ){ value = c==3 ? SMALLEST_INT64 : -value; }
sqlite3VdbeAddOp4Dup8(v, OP_Int64, 0, iMem, 0, (u8*)&value, P4_INT64);
}
}
}
/* Generate code that will load into register regOut a value that is
** appropriate for the iIdxCol-th column of index pIdx.
*/
void sqlite3ExprCodeLoadIndexColumn(
Parse *pParse, /* The parsing context */
Index *pIdx, /* The index whose column is to be loaded */
int iTabCur, /* Cursor pointing to a table row */
int iIdxCol, /* The column of the index to be loaded */
int regOut /* Store the index column value in this register */
){
i16 iTabCol = pIdx->aiColumn[iIdxCol];
if( iTabCol==XN_EXPR ){
assert( pIdx->aColExpr );
assert( pIdx->aColExpr->nExpr>iIdxCol );
pParse->iSelfTab = iTabCur + 1;
sqlite3ExprCodeCopy(pParse, pIdx->aColExpr->a[iIdxCol].pExpr, regOut);
pParse->iSelfTab = 0;
}else{
sqlite3ExprCodeGetColumnOfTable(pParse->pVdbe, pIdx->pTable, iTabCur,
iTabCol, regOut);
}
}
#ifndef SQLITE_OMIT_GENERATED_COLUMNS
/*
** Generate code that will compute the value of generated column pCol
** and store the result in register regOut
*/
void sqlite3ExprCodeGeneratedColumn(
Parse *pParse, /* Parsing context */
Table *pTab, /* Table containing the generated column */
Column *pCol, /* The generated column */
int regOut /* Put the result in this register */
){
int iAddr;
Vdbe *v = pParse->pVdbe;
int nErr = pParse->nErr;
assert( v!=0 );
assert( pParse->iSelfTab!=0 );
if( pParse->iSelfTab>0 ){
iAddr = sqlite3VdbeAddOp3(v, OP_IfNullRow, pParse->iSelfTab-1, 0, regOut);
}else{
iAddr = 0;
}
sqlite3ExprCodeCopy(pParse, sqlite3ColumnExpr(pTab,pCol), regOut);
if( pCol->affinity>=SQLITE_AFF_TEXT ){
sqlite3VdbeAddOp4(v, OP_Affinity, regOut, 1, 0, &pCol->affinity, 1);
}
if( iAddr ) sqlite3VdbeJumpHere(v, iAddr);
if( pParse->nErr>nErr ) pParse->db->errByteOffset = -1;
}
#endif /* SQLITE_OMIT_GENERATED_COLUMNS */
/*
** Generate code to extract the value of the iCol-th column of a table.
*/
void sqlite3ExprCodeGetColumnOfTable(
Vdbe *v, /* Parsing context */
Table *pTab, /* The table containing the value */
int iTabCur, /* The table cursor. Or the PK cursor for WITHOUT ROWID */
int iCol, /* Index of the column to extract */
int regOut /* Extract the value into this register */
){
Column *pCol;
assert( v!=0 );
assert( pTab!=0 );
assert( iCol!=XN_EXPR );
if( iCol<0 || iCol==pTab->iPKey ){
sqlite3VdbeAddOp2(v, OP_Rowid, iTabCur, regOut);
VdbeComment((v, "%s.rowid", pTab->zName));
}else{
int op;
int x;
if( IsVirtual(pTab) ){
op = OP_VColumn;
x = iCol;
#ifndef SQLITE_OMIT_GENERATED_COLUMNS
}else if( (pCol = &pTab->aCol[iCol])->colFlags & COLFLAG_VIRTUAL ){
Parse *pParse = sqlite3VdbeParser(v);
if( pCol->colFlags & COLFLAG_BUSY ){
sqlite3ErrorMsg(pParse, "generated column loop on \"%s\"",
pCol->zCnName);
}else{
int savedSelfTab = pParse->iSelfTab;
pCol->colFlags |= COLFLAG_BUSY;
pParse->iSelfTab = iTabCur+1;
sqlite3ExprCodeGeneratedColumn(pParse, pTab, pCol, regOut);
pParse->iSelfTab = savedSelfTab;
pCol->colFlags &= ~COLFLAG_BUSY;
}
return;
#endif
}else if( !HasRowid(pTab) ){
testcase( iCol!=sqlite3TableColumnToStorage(pTab, iCol) );
x = sqlite3TableColumnToIndex(sqlite3PrimaryKeyIndex(pTab), iCol);
op = OP_Column;
}else{
x = sqlite3TableColumnToStorage(pTab,iCol);
testcase( x!=iCol );
op = OP_Column;
}
sqlite3VdbeAddOp3(v, op, iTabCur, x, regOut);
sqlite3ColumnDefault(v, pTab, iCol, regOut);
}
}
/*
** Generate code that will extract the iColumn-th column from
** table pTab and store the column value in register iReg.
**
** There must be an open cursor to pTab in iTable when this routine
** is called. If iColumn<0 then code is generated that extracts the rowid.
*/
int sqlite3ExprCodeGetColumn(
Parse *pParse, /* Parsing and code generating context */
Table *pTab, /* Description of the table we are reading from */
int iColumn, /* Index of the table column */
int iTable, /* The cursor pointing to the table */
int iReg, /* Store results here */
u8 p5 /* P5 value for OP_Column + FLAGS */
){
assert( pParse->pVdbe!=0 );
assert( (p5 & (OPFLAG_NOCHNG|OPFLAG_TYPEOFARG|OPFLAG_LENGTHARG))==p5 );
assert( IsVirtual(pTab) || (p5 & OPFLAG_NOCHNG)==0 );
sqlite3ExprCodeGetColumnOfTable(pParse->pVdbe, pTab, iTable, iColumn, iReg);
if( p5 ){
VdbeOp *pOp = sqlite3VdbeGetLastOp(pParse->pVdbe);
if( pOp->opcode==OP_Column ) pOp->p5 = p5;
if( pOp->opcode==OP_VColumn ) pOp->p5 = (p5 & OPFLAG_NOCHNG);
}
return iReg;
}
/*
** Generate code to move content from registers iFrom...iFrom+nReg-1
** over to iTo..iTo+nReg-1.
*/
void sqlite3ExprCodeMove(Parse *pParse, int iFrom, int iTo, int nReg){
sqlite3VdbeAddOp3(pParse->pVdbe, OP_Move, iFrom, iTo, nReg);
}
/*
** Convert a scalar expression node to a TK_REGISTER referencing
** register iReg. The caller must ensure that iReg already contains
** the correct value for the expression.
*/
void sqlite3ExprToRegister(Expr *pExpr, int iReg){
Expr *p = sqlite3ExprSkipCollateAndLikely(pExpr);
if( NEVER(p==0) ) return;
if( p->op==TK_REGISTER ){
assert( p->iTable==iReg );
}else{
p->op2 = p->op;
p->op = TK_REGISTER;
p->iTable = iReg;
ExprClearProperty(p, EP_Skip);
}
}
/*
** Evaluate an expression (either a vector or a scalar expression) and store
** the result in contiguous temporary registers. Return the index of
** the first register used to store the result.
**
** If the returned result register is a temporary scalar, then also write
** that register number into *piFreeable. If the returned result register
** is not a temporary or if the expression is a vector set *piFreeable
** to 0.
*/
static int exprCodeVector(Parse *pParse, Expr *p, int *piFreeable){
int iResult;
int nResult = sqlite3ExprVectorSize(p);
if( nResult==1 ){
iResult = sqlite3ExprCodeTemp(pParse, p, piFreeable);
}else{
*piFreeable = 0;
if( p->op==TK_SELECT ){
#if SQLITE_OMIT_SUBQUERY
iResult = 0;
#else
iResult = sqlite3CodeSubselect(pParse, p);
#endif
}else{
int i;
iResult = pParse->nMem+1;
pParse->nMem += nResult;
assert( ExprUseXList(p) );
for(i=0; i<nResult; i++){
sqlite3ExprCodeFactorable(pParse, p->x.pList->a[i].pExpr, i+iResult);
}
}
}
return iResult;
}
/*
** If the last opcode is a OP_Copy, then set the do-not-merge flag (p5)
** so that a subsequent copy will not be merged into this one.
*/
static void setDoNotMergeFlagOnCopy(Vdbe *v){
if( sqlite3VdbeGetLastOp(v)->opcode==OP_Copy ){
sqlite3VdbeChangeP5(v, 1); /* Tag trailing OP_Copy as not mergeable */
}
}
/*
** Generate code to implement special SQL functions that are implemented
** in-line rather than by using the usual callbacks.
*/
static int exprCodeInlineFunction(
Parse *pParse, /* Parsing context */
ExprList *pFarg, /* List of function arguments */
int iFuncId, /* Function ID. One of the INTFUNC_... values */
int target /* Store function result in this register */
){
int nFarg;
Vdbe *v = pParse->pVdbe;
assert( v!=0 );
assert( pFarg!=0 );
nFarg = pFarg->nExpr;
assert( nFarg>0 ); /* All in-line functions have at least one argument */
switch( iFuncId ){
case INLINEFUNC_coalesce: {
/* Attempt a direct implementation of the built-in COALESCE() and
** IFNULL() functions. This avoids unnecessary evaluation of
** arguments past the first non-NULL argument.
*/
int endCoalesce = sqlite3VdbeMakeLabel(pParse);
int i;
assert( nFarg>=2 );
sqlite3ExprCode(pParse, pFarg->a[0].pExpr, target);
for(i=1; i<nFarg; i++){
sqlite3VdbeAddOp2(v, OP_NotNull, target, endCoalesce);
VdbeCoverage(v);
sqlite3ExprCode(pParse, pFarg->a[i].pExpr, target);
}
setDoNotMergeFlagOnCopy(v);
sqlite3VdbeResolveLabel(v, endCoalesce);
break;
}
case INLINEFUNC_iif: {
Expr caseExpr;
memset(&caseExpr, 0, sizeof(caseExpr));
caseExpr.op = TK_CASE;
caseExpr.x.pList = pFarg;
return sqlite3ExprCodeTarget(pParse, &caseExpr, target);
}
#ifdef SQLITE_ENABLE_OFFSET_SQL_FUNC
case INLINEFUNC_sqlite_offset: {
Expr *pArg = pFarg->a[0].pExpr;
if( pArg->op==TK_COLUMN && pArg->iTable>=0 ){
sqlite3VdbeAddOp3(v, OP_Offset, pArg->iTable, pArg->iColumn, target);
}else{
sqlite3VdbeAddOp2(v, OP_Null, 0, target);
}
break;
}
#endif
default: {
/* The UNLIKELY() function is a no-op. The result is the value
** of the first argument.
*/
assert( nFarg==1 || nFarg==2 );
target = sqlite3ExprCodeTarget(pParse, pFarg->a[0].pExpr, target);
break;
}
/***********************************************************************
** Test-only SQL functions that are only usable if enabled
** via SQLITE_TESTCTRL_INTERNAL_FUNCTIONS
*/
#if !defined(SQLITE_UNTESTABLE)
case INLINEFUNC_expr_compare: {
/* Compare two expressions using sqlite3ExprCompare() */
assert( nFarg==2 );
sqlite3VdbeAddOp2(v, OP_Integer,
sqlite3ExprCompare(0,pFarg->a[0].pExpr, pFarg->a[1].pExpr,-1),
target);
break;
}
case INLINEFUNC_expr_implies_expr: {
/* Compare two expressions using sqlite3ExprImpliesExpr() */
assert( nFarg==2 );
sqlite3VdbeAddOp2(v, OP_Integer,
sqlite3ExprImpliesExpr(pParse,pFarg->a[0].pExpr, pFarg->a[1].pExpr,-1),
target);
break;
}
case INLINEFUNC_implies_nonnull_row: {
/* Result of sqlite3ExprImpliesNonNullRow() */
Expr *pA1;
assert( nFarg==2 );
pA1 = pFarg->a[1].pExpr;
if( pA1->op==TK_COLUMN ){
sqlite3VdbeAddOp2(v, OP_Integer,
sqlite3ExprImpliesNonNullRow(pFarg->a[0].pExpr,pA1->iTable,1),
target);
}else{
sqlite3VdbeAddOp2(v, OP_Null, 0, target);
}
break;
}
case INLINEFUNC_affinity: {
/* The AFFINITY() function evaluates to a string that describes
** the type affinity of the argument. This is used for testing of
** the SQLite type logic.
*/
const char *azAff[] = { "blob", "text", "numeric", "integer",
"real", "flexnum" };
char aff;
assert( nFarg==1 );
aff = sqlite3ExprAffinity(pFarg->a[0].pExpr);
assert( aff<=SQLITE_AFF_NONE
|| (aff>=SQLITE_AFF_BLOB && aff<=SQLITE_AFF_FLEXNUM) );
sqlite3VdbeLoadString(v, target,
(aff<=SQLITE_AFF_NONE) ? "none" : azAff[aff-SQLITE_AFF_BLOB]);
break;
}
#endif /* !defined(SQLITE_UNTESTABLE) */
}
return target;
}
/*
** Expression Node callback for sqlite3ExprCanReturnSubtype().
**
** Only a function call is able to return a subtype. So if the node
** is not a function call, return WRC_Prune immediately.
**
** A function call is able to return a subtype if it has the
** SQLITE_RESULT_SUBTYPE property.
**
** Assume that every function is able to pass-through a subtype from
** one of its argument (using sqlite3_result_value()). Most functions
** are not this way, but we don't have a mechanism to distinguish those
** that are from those that are not, so assume they all work this way.
** That means that if one of its arguments is another function and that
** other function is able to return a subtype, then this function is
** able to return a subtype.
*/
static int exprNodeCanReturnSubtype(Walker *pWalker, Expr *pExpr){
int n;
FuncDef *pDef;
sqlite3 *db;
if( pExpr->op!=TK_FUNCTION ){
return WRC_Prune;
}
assert( ExprUseXList(pExpr) );
db = pWalker->pParse->db;
n = ALWAYS(pExpr->x.pList) ? pExpr->x.pList->nExpr : 0;
pDef = sqlite3FindFunction(db, pExpr->u.zToken, n, ENC(db), 0);
if( NEVER(pDef==0) || (pDef->funcFlags & SQLITE_RESULT_SUBTYPE)!=0 ){
pWalker->eCode = 1;
return WRC_Prune;
}
return WRC_Continue;
}
/*
** Return TRUE if expression pExpr is able to return a subtype.
**
** A TRUE return does not guarantee that a subtype will be returned.
** It only indicates that a subtype return is possible. False positives
** are acceptable as they only disable an optimization. False negatives,
** on the other hand, can lead to incorrect answers.
*/
static int sqlite3ExprCanReturnSubtype(Parse *pParse, Expr *pExpr){
Walker w;
memset(&w, 0, sizeof(w));
w.pParse = pParse;
w.xExprCallback = exprNodeCanReturnSubtype;
sqlite3WalkExpr(&w, pExpr);
return w.eCode;
}
/*
** Check to see if pExpr is one of the indexed expressions on pParse->pIdxEpr.
** If it is, then resolve the expression by reading from the index and
** return the register into which the value has been read. If pExpr is
** not an indexed expression, then return negative.
*/
static SQLITE_NOINLINE int sqlite3IndexedExprLookup(
Parse *pParse, /* The parsing context */
Expr *pExpr, /* The expression to potentially bypass */
int target /* Where to store the result of the expression */
){
IndexedExpr *p;
Vdbe *v;
for(p=pParse->pIdxEpr; p; p=p->pIENext){
u8 exprAff;
int iDataCur = p->iDataCur;
if( iDataCur<0 ) continue;
if( pParse->iSelfTab ){
if( p->iDataCur!=pParse->iSelfTab-1 ) continue;
iDataCur = -1;
}
if( sqlite3ExprCompare(0, pExpr, p->pExpr, iDataCur)!=0 ) continue;
assert( p->aff>=SQLITE_AFF_BLOB && p->aff<=SQLITE_AFF_NUMERIC );
exprAff = sqlite3ExprAffinity(pExpr);
if( (exprAff<=SQLITE_AFF_BLOB && p->aff!=SQLITE_AFF_BLOB)
|| (exprAff==SQLITE_AFF_TEXT && p->aff!=SQLITE_AFF_TEXT)
|| (exprAff>=SQLITE_AFF_NUMERIC && p->aff!=SQLITE_AFF_NUMERIC)
){
/* Affinity mismatch on a generated column */
continue;
}
/* Functions that might set a subtype should not be replaced by the
** value taken from an expression index if they are themselves an
** argument to another scalar function or aggregate.
** https://sqlite.org/forum/forumpost/68d284c86b082c3e */
if( ExprHasProperty(pExpr, EP_SubtArg)
&& sqlite3ExprCanReturnSubtype(pParse, pExpr)
){
continue;
}
v = pParse->pVdbe;
assert( v!=0 );
if( p->bMaybeNullRow ){
/* If the index is on a NULL row due to an outer join, then we
** cannot extract the value from the index. The value must be
** computed using the original expression. */
int addr = sqlite3VdbeCurrentAddr(v);
sqlite3VdbeAddOp3(v, OP_IfNullRow, p->iIdxCur, addr+3, target);
VdbeCoverage(v);
sqlite3VdbeAddOp3(v, OP_Column, p->iIdxCur, p->iIdxCol, target);
VdbeComment((v, "%s expr-column %d", p->zIdxName, p->iIdxCol));
sqlite3VdbeGoto(v, 0);
p = pParse->pIdxEpr;
pParse->pIdxEpr = 0;
sqlite3ExprCode(pParse, pExpr, target);
pParse->pIdxEpr = p;
sqlite3VdbeJumpHere(v, addr+2);
}else{
sqlite3VdbeAddOp3(v, OP_Column, p->iIdxCur, p->iIdxCol, target);
VdbeComment((v, "%s expr-column %d", p->zIdxName, p->iIdxCol));
}
return target;
}
return -1; /* Not found */
}
/*
** Expresion pExpr is guaranteed to be a TK_COLUMN or equivalent. This
** function checks the Parse.pIdxPartExpr list to see if this column
** can be replaced with a constant value. If so, it generates code to
** put the constant value in a register (ideally, but not necessarily,
** register iTarget) and returns the register number.
**
** Or, if the TK_COLUMN cannot be replaced by a constant, zero is
** returned.
*/
static int exprPartidxExprLookup(Parse *pParse, Expr *pExpr, int iTarget){
IndexedExpr *p;
for(p=pParse->pIdxPartExpr; p; p=p->pIENext){
if( pExpr->iColumn==p->iIdxCol && pExpr->iTable==p->iDataCur ){
Vdbe *v = pParse->pVdbe;
int addr = 0;
int ret;
if( p->bMaybeNullRow ){
addr = sqlite3VdbeAddOp1(v, OP_IfNullRow, p->iIdxCur);
}
ret = sqlite3ExprCodeTarget(pParse, p->pExpr, iTarget);
sqlite3VdbeAddOp4(pParse->pVdbe, OP_Affinity, ret, 1, 0,
(const char*)&p->aff, 1);
if( addr ){
sqlite3VdbeJumpHere(v, addr);
sqlite3VdbeChangeP3(v, addr, ret);
}
return ret;
}
}
return 0;
}
/*
** Generate code into the current Vdbe to evaluate the given
** expression. Attempt to store the results in register "target".
** Return the register where results are stored.
**
** With this routine, there is no guarantee that results will
** be stored in target. The result might be stored in some other
** register if it is convenient to do so. The calling function
** must check the return code and move the results to the desired
** register.
*/
int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target){
Vdbe *v = pParse->pVdbe; /* The VM under construction */
int op; /* The opcode being coded */
int inReg = target; /* Results stored in register inReg */
int regFree1 = 0; /* If non-zero free this temporary register */
int regFree2 = 0; /* If non-zero free this temporary register */
int r1, r2; /* Various register numbers */
Expr tempX; /* Temporary expression node */
int p5 = 0;
assert( target>0 && target<=pParse->nMem );
assert( v!=0 );
expr_code_doover:
if( pExpr==0 ){
op = TK_NULL;
}else if( pParse->pIdxEpr!=0
&& !ExprHasProperty(pExpr, EP_Leaf)
&& (r1 = sqlite3IndexedExprLookup(pParse, pExpr, target))>=0
){
return r1;
}else{
assert( !ExprHasVVAProperty(pExpr,EP_Immutable) );
op = pExpr->op;
}
assert( op!=TK_ORDER );
switch( op ){
case TK_AGG_COLUMN: {
AggInfo *pAggInfo = pExpr->pAggInfo;
struct AggInfo_col *pCol;
assert( pAggInfo!=0 );
assert( pExpr->iAgg>=0 );
if( pExpr->iAgg>=pAggInfo->nColumn ){
/* Happens when the left table of a RIGHT JOIN is null and
** is using an expression index */
sqlite3VdbeAddOp2(v, OP_Null, 0, target);
#ifdef SQLITE_VDBE_COVERAGE
/* Verify that the OP_Null above is exercised by tests
** tag-20230325-2 */
sqlite3VdbeAddOp3(v, OP_NotNull, target, 1, 20230325);
VdbeCoverageNeverTaken(v);
#endif
break;
}
pCol = &pAggInfo->aCol[pExpr->iAgg];
if( !pAggInfo->directMode ){
return AggInfoColumnReg(pAggInfo, pExpr->iAgg);
}else if( pAggInfo->useSortingIdx ){
Table *pTab = pCol->pTab;
sqlite3VdbeAddOp3(v, OP_Column, pAggInfo->sortingIdxPTab,
pCol->iSorterColumn, target);
if( pTab==0 ){
/* No comment added */
}else if( pCol->iColumn<0 ){
VdbeComment((v,"%s.rowid",pTab->zName));
}else{
VdbeComment((v,"%s.%s",
pTab->zName, pTab->aCol[pCol->iColumn].zCnName));
if( pTab->aCol[pCol->iColumn].affinity==SQLITE_AFF_REAL ){
sqlite3VdbeAddOp1(v, OP_RealAffinity, target);
}
}
return target;
}else if( pExpr->y.pTab==0 ){
/* This case happens when the argument to an aggregate function
** is rewritten by aggregateConvertIndexedExprRefToColumn() */
sqlite3VdbeAddOp3(v, OP_Column, pExpr->iTable, pExpr->iColumn, target);
return target;
}
/* Otherwise, fall thru into the TK_COLUMN case */
/* no break */ deliberate_fall_through
}
case TK_COLUMN: {
int iTab = pExpr->iTable;
int iReg;
if( ExprHasProperty(pExpr, EP_FixedCol) ){
/* This COLUMN expression is really a constant due to WHERE clause
** constraints, and that constant is coded by the pExpr->pLeft
** expression. However, make sure the constant has the correct
** datatype by applying the Affinity of the table column to the
** constant.
*/
int aff;
iReg = sqlite3ExprCodeTarget(pParse, pExpr->pLeft,target);
assert( ExprUseYTab(pExpr) );
assert( pExpr->y.pTab!=0 );
aff = sqlite3TableColumnAffinity(pExpr->y.pTab, pExpr->iColumn);
if( aff>SQLITE_AFF_BLOB ){
static const char zAff[] = "B\000C\000D\000E\000F";
assert( SQLITE_AFF_BLOB=='A' );
assert( SQLITE_AFF_TEXT=='B' );
sqlite3VdbeAddOp4(v, OP_Affinity, iReg, 1, 0,
&zAff[(aff-'B')*2], P4_STATIC);
}
return iReg;
}
if( iTab<0 ){
if( pParse->iSelfTab<0 ){
/* Other columns in the same row for CHECK constraints or
** generated columns or for inserting into partial index.
** The row is unpacked into registers beginning at
** 0-(pParse->iSelfTab). The rowid (if any) is in a register
** immediately prior to the first column.
*/
Column *pCol;
Table *pTab;
int iSrc;
int iCol = pExpr->iColumn;
assert( ExprUseYTab(pExpr) );
pTab = pExpr->y.pTab;
assert( pTab!=0 );
assert( iCol>=XN_ROWID );
assert( iCol<pTab->nCol );
if( iCol<0 ){
return -1-pParse->iSelfTab;
}
pCol = pTab->aCol + iCol;
testcase( iCol!=sqlite3TableColumnToStorage(pTab,iCol) );
iSrc = sqlite3TableColumnToStorage(pTab, iCol) - pParse->iSelfTab;
#ifndef SQLITE_OMIT_GENERATED_COLUMNS
if( pCol->colFlags & COLFLAG_GENERATED ){
if( pCol->colFlags & COLFLAG_BUSY ){
sqlite3ErrorMsg(pParse, "generated column loop on \"%s\"",
pCol->zCnName);
return 0;
}
pCol->colFlags |= COLFLAG_BUSY;
if( pCol->colFlags & COLFLAG_NOTAVAIL ){
sqlite3ExprCodeGeneratedColumn(pParse, pTab, pCol, iSrc);
}
pCol->colFlags &= ~(COLFLAG_BUSY|COLFLAG_NOTAVAIL);
return iSrc;
}else
#endif /* SQLITE_OMIT_GENERATED_COLUMNS */
if( pCol->affinity==SQLITE_AFF_REAL ){
sqlite3VdbeAddOp2(v, OP_SCopy, iSrc, target);
sqlite3VdbeAddOp1(v, OP_RealAffinity, target);
return target;
}else{
return iSrc;
}
}else{
/* Coding an expression that is part of an index where column names
** in the index refer to the table to which the index belongs */
iTab = pParse->iSelfTab - 1;
}
}
else if( pParse->pIdxPartExpr
&& 0!=(r1 = exprPartidxExprLookup(pParse, pExpr, target))
){
return r1;
}
assert( ExprUseYTab(pExpr) );
assert( pExpr->y.pTab!=0 );
iReg = sqlite3ExprCodeGetColumn(pParse, pExpr->y.pTab,
pExpr->iColumn, iTab, target,
pExpr->op2);
return iReg;
}
case TK_INTEGER: {
codeInteger(pParse, pExpr, 0, target);
return target;
}
case TK_TRUEFALSE: {
sqlite3VdbeAddOp2(v, OP_Integer, sqlite3ExprTruthValue(pExpr), target);
return target;
}
#ifndef SQLITE_OMIT_FLOATING_POINT
case TK_FLOAT: {
assert( !ExprHasProperty(pExpr, EP_IntValue) );
codeReal(v, pExpr->u.zToken, 0, target);
return target;
}
#endif
case TK_STRING: {
assert( !ExprHasProperty(pExpr, EP_IntValue) );
sqlite3VdbeLoadString(v, target, pExpr->u.zToken);
return target;
}
default: {
/* Make NULL the default case so that if a bug causes an illegal
** Expr node to be passed into this function, it will be handled
** sanely and not crash. But keep the assert() to bring the problem
** to the attention of the developers. */
assert( op==TK_NULL || op==TK_ERROR || pParse->db->mallocFailed );
sqlite3VdbeAddOp2(v, OP_Null, 0, target);
return target;
}
#ifndef SQLITE_OMIT_BLOB_LITERAL
case TK_BLOB: {
int n;
const char *z;
char *zBlob;
assert( !ExprHasProperty(pExpr, EP_IntValue) );
assert( pExpr->u.zToken[0]=='x' || pExpr->u.zToken[0]=='X' );
assert( pExpr->u.zToken[1]=='\'' );
z = &pExpr->u.zToken[2];
n = sqlite3Strlen30(z) - 1;
assert( z[n]=='\'' );
zBlob = sqlite3HexToBlob(sqlite3VdbeDb(v), z, n);
sqlite3VdbeAddOp4(v, OP_Blob, n/2, target, 0, zBlob, P4_DYNAMIC);
return target;
}
#endif
case TK_VARIABLE: {
assert( !ExprHasProperty(pExpr, EP_IntValue) );
assert( pExpr->u.zToken!=0 );
assert( pExpr->u.zToken[0]!=0 );
sqlite3VdbeAddOp2(v, OP_Variable, pExpr->iColumn, target);
return target;
}
case TK_REGISTER: {
return pExpr->iTable;
}
#ifndef SQLITE_OMIT_CAST
case TK_CAST: {
/* Expressions of the form: CAST(pLeft AS token) */
sqlite3ExprCode(pParse, pExpr->pLeft, target);
assert( inReg==target );
assert( !ExprHasProperty(pExpr, EP_IntValue) );
sqlite3VdbeAddOp2(v, OP_Cast, target,
sqlite3AffinityType(pExpr->u.zToken, 0));
return inReg;
}
#endif /* SQLITE_OMIT_CAST */
case TK_IS:
case TK_ISNOT:
op = (op==TK_IS) ? TK_EQ : TK_NE;
p5 = SQLITE_NULLEQ;
/* fall-through */
case TK_LT:
case TK_LE:
case TK_GT:
case TK_GE:
case TK_NE:
case TK_EQ: {
Expr *pLeft = pExpr->pLeft;
if( sqlite3ExprIsVector(pLeft) ){
codeVectorCompare(pParse, pExpr, target, op, p5);
}else{
r1 = sqlite3ExprCodeTemp(pParse, pLeft, &regFree1);
r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, &regFree2);
sqlite3VdbeAddOp2(v, OP_Integer, 1, inReg);
codeCompare(pParse, pLeft, pExpr->pRight, op, r1, r2,
sqlite3VdbeCurrentAddr(v)+2, p5,
ExprHasProperty(pExpr,EP_Commuted));
assert(TK_LT==OP_Lt); testcase(op==OP_Lt); VdbeCoverageIf(v,op==OP_Lt);
assert(TK_LE==OP_Le); testcase(op==OP_Le); VdbeCoverageIf(v,op==OP_Le);
assert(TK_GT==OP_Gt); testcase(op==OP_Gt); VdbeCoverageIf(v,op==OP_Gt);
assert(TK_GE==OP_Ge); testcase(op==OP_Ge); VdbeCoverageIf(v,op==OP_Ge);
assert(TK_EQ==OP_Eq); testcase(op==OP_Eq); VdbeCoverageIf(v,op==OP_Eq);
assert(TK_NE==OP_Ne); testcase(op==OP_Ne); VdbeCoverageIf(v,op==OP_Ne);
if( p5==SQLITE_NULLEQ ){
sqlite3VdbeAddOp2(v, OP_Integer, 0, inReg);
}else{
sqlite3VdbeAddOp3(v, OP_ZeroOrNull, r1, inReg, r2);
}
testcase( regFree1==0 );
testcase( regFree2==0 );
}
break;
}
case TK_AND:
case TK_OR:
case TK_PLUS:
case TK_STAR:
case TK_MINUS:
case TK_REM:
case TK_BITAND:
case TK_BITOR:
case TK_SLASH:
case TK_LSHIFT:
case TK_RSHIFT:
case TK_CONCAT: {
assert( TK_AND==OP_And ); testcase( op==TK_AND );
assert( TK_OR==OP_Or ); testcase( op==TK_OR );
assert( TK_PLUS==OP_Add ); testcase( op==TK_PLUS );
assert( TK_MINUS==OP_Subtract ); testcase( op==TK_MINUS );
assert( TK_REM==OP_Remainder ); testcase( op==TK_REM );
assert( TK_BITAND==OP_BitAnd ); testcase( op==TK_BITAND );
assert( TK_BITOR==OP_BitOr ); testcase( op==TK_BITOR );
assert( TK_SLASH==OP_Divide ); testcase( op==TK_SLASH );
assert( TK_LSHIFT==OP_ShiftLeft ); testcase( op==TK_LSHIFT );
assert( TK_RSHIFT==OP_ShiftRight ); testcase( op==TK_RSHIFT );
assert( TK_CONCAT==OP_Concat ); testcase( op==TK_CONCAT );
r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, &regFree1);
r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, &regFree2);
sqlite3VdbeAddOp3(v, op, r2, r1, target);
testcase( regFree1==0 );
testcase( regFree2==0 );
break;
}
case TK_UMINUS: {
Expr *pLeft = pExpr->pLeft;
assert( pLeft );
if( pLeft->op==TK_INTEGER ){
codeInteger(pParse, pLeft, 1, target);
return target;
#ifndef SQLITE_OMIT_FLOATING_POINT
}else if( pLeft->op==TK_FLOAT ){
assert( !ExprHasProperty(pExpr, EP_IntValue) );
codeReal(v, pLeft->u.zToken, 1, target);
return target;
#endif
}else{
tempX.op = TK_INTEGER;
tempX.flags = EP_IntValue|EP_TokenOnly;
tempX.u.iValue = 0;
ExprClearVVAProperties(&tempX);
r1 = sqlite3ExprCodeTemp(pParse, &tempX, &regFree1);
r2 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, &regFree2);
sqlite3VdbeAddOp3(v, OP_Subtract, r2, r1, target);
testcase( regFree2==0 );
}
break;
}
case TK_BITNOT:
case TK_NOT: {
assert( TK_BITNOT==OP_BitNot ); testcase( op==TK_BITNOT );
assert( TK_NOT==OP_Not ); testcase( op==TK_NOT );
r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, &regFree1);
testcase( regFree1==0 );
sqlite3VdbeAddOp2(v, op, r1, inReg);
break;
}
case TK_TRUTH: {
int isTrue; /* IS TRUE or IS NOT TRUE */
int bNormal; /* IS TRUE or IS FALSE */
r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, &regFree1);
testcase( regFree1==0 );
isTrue = sqlite3ExprTruthValue(pExpr->pRight);
bNormal = pExpr->op2==TK_IS;
testcase( isTrue && bNormal);
testcase( !isTrue && bNormal);
sqlite3VdbeAddOp4Int(v, OP_IsTrue, r1, inReg, !isTrue, isTrue ^ bNormal);
break;
}
case TK_ISNULL:
case TK_NOTNULL: {
int addr;
assert( TK_ISNULL==OP_IsNull ); testcase( op==TK_ISNULL );
assert( TK_NOTNULL==OP_NotNull ); testcase( op==TK_NOTNULL );
sqlite3VdbeAddOp2(v, OP_Integer, 1, target);
r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, &regFree1);
testcase( regFree1==0 );
addr = sqlite3VdbeAddOp1(v, op, r1);
VdbeCoverageIf(v, op==TK_ISNULL);
VdbeCoverageIf(v, op==TK_NOTNULL);
sqlite3VdbeAddOp2(v, OP_Integer, 0, target);
sqlite3VdbeJumpHere(v, addr);
break;
}
case TK_AGG_FUNCTION: {
AggInfo *pInfo = pExpr->pAggInfo;
if( pInfo==0
|| NEVER(pExpr->iAgg<0)
|| NEVER(pExpr->iAgg>=pInfo->nFunc)
){
assert( !ExprHasProperty(pExpr, EP_IntValue) );
sqlite3ErrorMsg(pParse, "misuse of aggregate: %#T()", pExpr);
}else{
return AggInfoFuncReg(pInfo, pExpr->iAgg);
}
break;
}
case TK_FUNCTION: {
ExprList *pFarg; /* List of function arguments */
int nFarg; /* Number of function arguments */
FuncDef *pDef; /* The function definition object */
const char *zId; /* The function name */
u32 constMask = 0; /* Mask of function arguments that are constant */
int i; /* Loop counter */
sqlite3 *db = pParse->db; /* The database connection */
u8 enc = ENC(db); /* The text encoding used by this database */
CollSeq *pColl = 0; /* A collating sequence */
#ifndef SQLITE_OMIT_WINDOWFUNC
if( ExprHasProperty(pExpr, EP_WinFunc) ){
return pExpr->y.pWin->regResult;
}
#endif
if( ConstFactorOk(pParse)
&& sqlite3ExprIsConstantNotJoin(pParse,pExpr)
){
/* SQL functions can be expensive. So try to avoid running them
** multiple times if we know they always give the same result */
return sqlite3ExprCodeRunJustOnce(pParse, pExpr, -1);
}
assert( !ExprHasProperty(pExpr, EP_TokenOnly) );
assert( ExprUseXList(pExpr) );
pFarg = pExpr->x.pList;
nFarg = pFarg ? pFarg->nExpr : 0;
assert( !ExprHasProperty(pExpr, EP_IntValue) );
zId = pExpr->u.zToken;
pDef = sqlite3FindFunction(db, zId, nFarg, enc, 0);
#ifdef SQLITE_ENABLE_UNKNOWN_SQL_FUNCTION
if( pDef==0 && pParse->explain ){
pDef = sqlite3FindFunction(db, "unknown", nFarg, enc, 0);
}
#endif
if( pDef==0 || pDef->xFinalize!=0 ){
sqlite3ErrorMsg(pParse, "unknown function: %#T()", pExpr);
break;
}
if( (pDef->funcFlags & SQLITE_FUNC_INLINE)!=0 && ALWAYS(pFarg!=0) ){
assert( (pDef->funcFlags & SQLITE_FUNC_UNSAFE)==0 );
assert( (pDef->funcFlags & SQLITE_FUNC_DIRECT)==0 );
return exprCodeInlineFunction(pParse, pFarg,
SQLITE_PTR_TO_INT(pDef->pUserData), target);
}else if( pDef->funcFlags & (SQLITE_FUNC_DIRECT|SQLITE_FUNC_UNSAFE) ){
sqlite3ExprFunctionUsable(pParse, pExpr, pDef);
}
for(i=0; i<nFarg; i++){
if( i<32 && sqlite3ExprIsConstant(pParse, pFarg->a[i].pExpr) ){
testcase( i==31 );
constMask |= MASKBIT32(i);
}
if( (pDef->funcFlags & SQLITE_FUNC_NEEDCOLL)!=0 && !pColl ){
pColl = sqlite3ExprCollSeq(pParse, pFarg->a[i].pExpr);
}
}
if( pFarg ){
if( constMask ){
r1 = pParse->nMem+1;
pParse->nMem += nFarg;
}else{
r1 = sqlite3GetTempRange(pParse, nFarg);
}
/* For length() and typeof() and octet_length() functions,
** set the P5 parameter to the OP_Column opcode to OPFLAG_LENGTHARG
** or OPFLAG_TYPEOFARG or OPFLAG_BYTELENARG respectively, to avoid
** unnecessary data loading.
*/
if( (pDef->funcFlags & (SQLITE_FUNC_LENGTH|SQLITE_FUNC_TYPEOF))!=0 ){
u8 exprOp;
assert( nFarg==1 );
assert( pFarg->a[0].pExpr!=0 );
exprOp = pFarg->a[0].pExpr->op;
if( exprOp==TK_COLUMN || exprOp==TK_AGG_COLUMN ){
assert( SQLITE_FUNC_LENGTH==OPFLAG_LENGTHARG );
assert( SQLITE_FUNC_TYPEOF==OPFLAG_TYPEOFARG );
assert( SQLITE_FUNC_BYTELEN==OPFLAG_BYTELENARG );
assert( (OPFLAG_LENGTHARG|OPFLAG_TYPEOFARG)==OPFLAG_BYTELENARG );
testcase( (pDef->funcFlags & OPFLAG_BYTELENARG)==OPFLAG_LENGTHARG );
testcase( (pDef->funcFlags & OPFLAG_BYTELENARG)==OPFLAG_TYPEOFARG );
testcase( (pDef->funcFlags & OPFLAG_BYTELENARG)==OPFLAG_BYTELENARG);
pFarg->a[0].pExpr->op2 = pDef->funcFlags & OPFLAG_BYTELENARG;
}
}
sqlite3ExprCodeExprList(pParse, pFarg, r1, 0, SQLITE_ECEL_FACTOR);
}else{
r1 = 0;
}
#ifndef SQLITE_OMIT_VIRTUALTABLE
/* Possibly overload the function if the first argument is
** a virtual table column.
**
** For infix functions (LIKE, GLOB, REGEXP, and MATCH) use the
** second argument, not the first, as the argument to test to
** see if it is a column in a virtual table. This is done because
** the left operand of infix functions (the operand we want to
** control overloading) ends up as the second argument to the
** function. The expression "A glob B" is equivalent to
** "glob(B,A). We want to use the A in "A glob B" to test
** for function overloading. But we use the B term in "glob(B,A)".
*/
if( nFarg>=2 && ExprHasProperty(pExpr, EP_InfixFunc) ){
pDef = sqlite3VtabOverloadFunction(db, pDef, nFarg, pFarg->a[1].pExpr);
}else if( nFarg>0 ){
pDef = sqlite3VtabOverloadFunction(db, pDef, nFarg, pFarg->a[0].pExpr);
}
#endif
if( pDef->funcFlags & SQLITE_FUNC_NEEDCOLL ){
if( !pColl ) pColl = db->pDfltColl;
sqlite3VdbeAddOp4(v, OP_CollSeq, 0, 0, 0, (char *)pColl, P4_COLLSEQ);
}
sqlite3VdbeAddFunctionCall(pParse, constMask, r1, target, nFarg,
pDef, pExpr->op2);
if( nFarg ){
if( constMask==0 ){
sqlite3ReleaseTempRange(pParse, r1, nFarg);
}else{
sqlite3VdbeReleaseRegisters(pParse, r1, nFarg, constMask, 1);
}
}
return target;
}
#ifndef SQLITE_OMIT_SUBQUERY
case TK_EXISTS:
case TK_SELECT: {
int nCol;
testcase( op==TK_EXISTS );
testcase( op==TK_SELECT );
if( pParse->db->mallocFailed ){
return 0;
}else if( op==TK_SELECT
&& ALWAYS( ExprUseXSelect(pExpr) )
&& (nCol = pExpr->x.pSelect->pEList->nExpr)!=1
){
sqlite3SubselectError(pParse, nCol, 1);
}else{
return sqlite3CodeSubselect(pParse, pExpr);
}
break;
}
case TK_SELECT_COLUMN: {
int n;
Expr *pLeft = pExpr->pLeft;
if( pLeft->iTable==0 || pParse->withinRJSubrtn > pLeft->op2 ){
pLeft->iTable = sqlite3CodeSubselect(pParse, pLeft);
pLeft->op2 = pParse->withinRJSubrtn;
}
assert( pLeft->op==TK_SELECT || pLeft->op==TK_ERROR );
n = sqlite3ExprVectorSize(pLeft);
if( pExpr->iTable!=n ){
sqlite3ErrorMsg(pParse, "%d columns assigned %d values",
pExpr->iTable, n);
}
return pLeft->iTable + pExpr->iColumn;
}
case TK_IN: {
int destIfFalse = sqlite3VdbeMakeLabel(pParse);
int destIfNull = sqlite3VdbeMakeLabel(pParse);
sqlite3VdbeAddOp2(v, OP_Null, 0, target);
sqlite3ExprCodeIN(pParse, pExpr, destIfFalse, destIfNull);
sqlite3VdbeAddOp2(v, OP_Integer, 1, target);
sqlite3VdbeResolveLabel(v, destIfFalse);
sqlite3VdbeAddOp2(v, OP_AddImm, target, 0);
sqlite3VdbeResolveLabel(v, destIfNull);
return target;
}
#endif /* SQLITE_OMIT_SUBQUERY */
/*
** x BETWEEN y AND z
**
** This is equivalent to
**
** x>=y AND x<=z
**
** X is stored in pExpr->pLeft.
** Y is stored in pExpr->pList->a[0].pExpr.
** Z is stored in pExpr->pList->a[1].pExpr.
*/
case TK_BETWEEN: {
exprCodeBetween(pParse, pExpr, target, 0, 0);
return target;
}
case TK_COLLATE: {
if( !ExprHasProperty(pExpr, EP_Collate) ){
/* A TK_COLLATE Expr node without the EP_Collate tag is a so-called
** "SOFT-COLLATE" that is added to constraints that are pushed down
** from outer queries into sub-queries by the WHERE-clause push-down
** optimization. Clear subtypes as subtypes may not cross a subquery
** boundary.
*/
assert( pExpr->pLeft );
sqlite3ExprCode(pParse, pExpr->pLeft, target);
sqlite3VdbeAddOp1(v, OP_ClrSubtype, target);
return target;
}else{
pExpr = pExpr->pLeft;
goto expr_code_doover; /* 2018-04-28: Prevent deep recursion. */
}
}
case TK_SPAN:
case TK_UPLUS: {
pExpr = pExpr->pLeft;
goto expr_code_doover; /* 2018-04-28: Prevent deep recursion. OSSFuzz. */
}
case TK_TRIGGER: {
/* If the opcode is TK_TRIGGER, then the expression is a reference
** to a column in the new.* or old.* pseudo-tables available to
** trigger programs. In this case Expr.iTable is set to 1 for the
** new.* pseudo-table, or 0 for the old.* pseudo-table. Expr.iColumn
** is set to the column of the pseudo-table to read, or to -1 to
** read the rowid field.
**
** The expression is implemented using an OP_Param opcode. The p1
** parameter is set to 0 for an old.rowid reference, or to (i+1)
** to reference another column of the old.* pseudo-table, where
** i is the index of the column. For a new.rowid reference, p1 is
** set to (n+1), where n is the number of columns in each pseudo-table.
** For a reference to any other column in the new.* pseudo-table, p1
** is set to (n+2+i), where n and i are as defined previously. For
** example, if the table on which triggers are being fired is
** declared as:
**
** CREATE TABLE t1(a, b);
**
** Then p1 is interpreted as follows:
**
** p1==0 -> old.rowid p1==3 -> new.rowid
** p1==1 -> old.a p1==4 -> new.a
** p1==2 -> old.b p1==5 -> new.b
*/
Table *pTab;
int iCol;
int p1;
assert( ExprUseYTab(pExpr) );
pTab = pExpr->y.pTab;
iCol = pExpr->iColumn;
p1 = pExpr->iTable * (pTab->nCol+1) + 1
+ sqlite3TableColumnToStorage(pTab, iCol);
assert( pExpr->iTable==0 || pExpr->iTable==1 );
assert( iCol>=-1 && iCol<pTab->nCol );
assert( pTab->iPKey<0 || iCol!=pTab->iPKey );
assert( p1>=0 && p1<(pTab->nCol*2+2) );
sqlite3VdbeAddOp2(v, OP_Param, p1, target);
VdbeComment((v, "r[%d]=%s.%s", target,
(pExpr->iTable ? "new" : "old"),
(pExpr->iColumn<0 ? "rowid" : pExpr->y.pTab->aCol[iCol].zCnName)
));
#ifndef SQLITE_OMIT_FLOATING_POINT
/* If the column has REAL affinity, it may currently be stored as an
** integer. Use OP_RealAffinity to make sure it is really real.
**
** EVIDENCE-OF: R-60985-57662 SQLite will convert the value back to
** floating point when extracting it from the record. */
if( iCol>=0 && pTab->aCol[iCol].affinity==SQLITE_AFF_REAL ){
sqlite3VdbeAddOp1(v, OP_RealAffinity, target);
}
#endif
break;
}
case TK_VECTOR: {
sqlite3ErrorMsg(pParse, "row value misused");
break;
}
/* TK_IF_NULL_ROW Expr nodes are inserted ahead of expressions
** that derive from the right-hand table of a LEFT JOIN. The
** Expr.iTable value is the table number for the right-hand table.
** The expression is only evaluated if that table is not currently
** on a LEFT JOIN NULL row.
*/
case TK_IF_NULL_ROW: {
int addrINR;
u8 okConstFactor = pParse->okConstFactor;
AggInfo *pAggInfo = pExpr->pAggInfo;
if( pAggInfo ){
assert( pExpr->iAgg>=0 && pExpr->iAgg<pAggInfo->nColumn );
if( !pAggInfo->directMode ){
inReg = AggInfoColumnReg(pAggInfo, pExpr->iAgg);
break;
}
if( pExpr->pAggInfo->useSortingIdx ){
sqlite3VdbeAddOp3(v, OP_Column, pAggInfo->sortingIdxPTab,
pAggInfo->aCol[pExpr->iAgg].iSorterColumn,
target);
inReg = target;
break;
}
}
addrINR = sqlite3VdbeAddOp3(v, OP_IfNullRow, pExpr->iTable, 0, target);
/* The OP_IfNullRow opcode above can overwrite the result register with
** NULL. So we have to ensure that the result register is not a value
** that is suppose to be a constant. Two defenses are needed:
** (1) Temporarily disable factoring of constant expressions
** (2) Make sure the computed value really is stored in register
** "target" and not someplace else.
*/
pParse->okConstFactor = 0; /* note (1) above */
sqlite3ExprCode(pParse, pExpr->pLeft, target);
assert( target==inReg );
pParse->okConstFactor = okConstFactor;
sqlite3VdbeJumpHere(v, addrINR);
break;
}
/*
** Form A:
** CASE x WHEN e1 THEN r1 WHEN e2 THEN r2 ... WHEN eN THEN rN ELSE y END
**
** Form B:
** CASE WHEN e1 THEN r1 WHEN e2 THEN r2 ... WHEN eN THEN rN ELSE y END
**
** Form A is can be transformed into the equivalent form B as follows:
** CASE WHEN x=e1 THEN r1 WHEN x=e2 THEN r2 ...
** WHEN x=eN THEN rN ELSE y END
**
** X (if it exists) is in pExpr->pLeft.
** Y is in the last element of pExpr->x.pList if pExpr->x.pList->nExpr is
** odd. The Y is also optional. If the number of elements in x.pList
** is even, then Y is omitted and the "otherwise" result is NULL.
** Ei is in pExpr->pList->a[i*2] and Ri is pExpr->pList->a[i*2+1].
**
** The result of the expression is the Ri for the first matching Ei,
** or if there is no matching Ei, the ELSE term Y, or if there is
** no ELSE term, NULL.
*/
case TK_CASE: {
int endLabel; /* GOTO label for end of CASE stmt */
int nextCase; /* GOTO label for next WHEN clause */
int nExpr; /* 2x number of WHEN terms */
int i; /* Loop counter */
ExprList *pEList; /* List of WHEN terms */
struct ExprList_item *aListelem; /* Array of WHEN terms */
Expr opCompare; /* The X==Ei expression */
Expr *pX; /* The X expression */
Expr *pTest = 0; /* X==Ei (form A) or just Ei (form B) */
Expr *pDel = 0;
sqlite3 *db = pParse->db;
assert( ExprUseXList(pExpr) && pExpr->x.pList!=0 );
assert(pExpr->x.pList->nExpr > 0);
pEList = pExpr->x.pList;
aListelem = pEList->a;
nExpr = pEList->nExpr;
endLabel = sqlite3VdbeMakeLabel(pParse);
if( (pX = pExpr->pLeft)!=0 ){
pDel = sqlite3ExprDup(db, pX, 0);
if( db->mallocFailed ){
sqlite3ExprDelete(db, pDel);
break;
}
testcase( pX->op==TK_COLUMN );
sqlite3ExprToRegister(pDel, exprCodeVector(pParse, pDel, &regFree1));
testcase( regFree1==0 );
memset(&opCompare, 0, sizeof(opCompare));
opCompare.op = TK_EQ;
opCompare.pLeft = pDel;
pTest = &opCompare;
/* Ticket b351d95f9cd5ef17e9d9dbae18f5ca8611190001:
** The value in regFree1 might get SCopy-ed into the file result.
** So make sure that the regFree1 register is not reused for other
** purposes and possibly overwritten. */
regFree1 = 0;
}
for(i=0; i<nExpr-1; i=i+2){
if( pX ){
assert( pTest!=0 );
opCompare.pRight = aListelem[i].pExpr;
}else{
pTest = aListelem[i].pExpr;
}
nextCase = sqlite3VdbeMakeLabel(pParse);
testcase( pTest->op==TK_COLUMN );
sqlite3ExprIfFalse(pParse, pTest, nextCase, SQLITE_JUMPIFNULL);
testcase( aListelem[i+1].pExpr->op==TK_COLUMN );
sqlite3ExprCode(pParse, aListelem[i+1].pExpr, target);
sqlite3VdbeGoto(v, endLabel);
sqlite3VdbeResolveLabel(v, nextCase);
}
if( (nExpr&1)!=0 ){
sqlite3ExprCode(pParse, pEList->a[nExpr-1].pExpr, target);
}else{
sqlite3VdbeAddOp2(v, OP_Null, 0, target);
}
sqlite3ExprDelete(db, pDel);
setDoNotMergeFlagOnCopy(v);
sqlite3VdbeResolveLabel(v, endLabel);
break;
}
#ifndef SQLITE_OMIT_TRIGGER
case TK_RAISE: {
assert( pExpr->affExpr==OE_Rollback
|| pExpr->affExpr==OE_Abort
|| pExpr->affExpr==OE_Fail
|| pExpr->affExpr==OE_Ignore
);
if( !pParse->pTriggerTab && !pParse->nested ){
sqlite3ErrorMsg(pParse,
"RAISE() may only be used within a trigger-program");
return 0;
}
if( pExpr->affExpr==OE_Abort ){
sqlite3MayAbort(pParse);
}
assert( !ExprHasProperty(pExpr, EP_IntValue) );
if( pExpr->affExpr==OE_Ignore ){
sqlite3VdbeAddOp2(v, OP_Halt, SQLITE_OK, OE_Ignore);
VdbeCoverage(v);
}else{
r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, &regFree1);
sqlite3VdbeAddOp3(v, OP_Halt,
pParse->pTriggerTab ? SQLITE_CONSTRAINT_TRIGGER : SQLITE_ERROR,
pExpr->affExpr, r1);
}
break;
}
#endif
}
sqlite3ReleaseTempReg(pParse, regFree1);
sqlite3ReleaseTempReg(pParse, regFree2);
return inReg;
}
/*
** Generate code that will evaluate expression pExpr just one time
** per prepared statement execution.
**
** If the expression uses functions (that might throw an exception) then
** guard them with an OP_Once opcode to ensure that the code is only executed
** once. If no functions are involved, then factor the code out and put it at
** the end of the prepared statement in the initialization section.
**
** If regDest>0 then the result is always stored in that register and the
** result is not reusable. If regDest<0 then this routine is free to
** store the value wherever it wants. The register where the expression
** is stored is returned. When regDest<0, two identical expressions might
** code to the same register, if they do not contain function calls and hence
** are factored out into the initialization section at the end of the
** prepared statement.
*/
int sqlite3ExprCodeRunJustOnce(
Parse *pParse, /* Parsing context */
Expr *pExpr, /* The expression to code when the VDBE initializes */
int regDest /* Store the value in this register */
){
ExprList *p;
assert( ConstFactorOk(pParse) );
assert( regDest!=0 );
p = pParse->pConstExpr;
if( regDest<0 && p ){
struct ExprList_item *pItem;
int i;
for(pItem=p->a, i=p->nExpr; i>0; pItem++, i--){
if( pItem->fg.reusable
&& sqlite3ExprCompare(0,pItem->pExpr,pExpr,-1)==0
){
return pItem->u.iConstExprReg;
}
}
}
pExpr = sqlite3ExprDup(pParse->db, pExpr, 0);
if( pExpr!=0 && ExprHasProperty(pExpr, EP_HasFunc) ){
Vdbe *v = pParse->pVdbe;
int addr;
assert( v );
addr = sqlite3VdbeAddOp0(v, OP_Once); VdbeCoverage(v);
pParse->okConstFactor = 0;
if( !pParse->db->mallocFailed ){
if( regDest<0 ) regDest = ++pParse->nMem;
sqlite3ExprCode(pParse, pExpr, regDest);
}
pParse->okConstFactor = 1;
sqlite3ExprDelete(pParse->db, pExpr);
sqlite3VdbeJumpHere(v, addr);
}else{
p = sqlite3ExprListAppend(pParse, p, pExpr);
if( p ){
struct ExprList_item *pItem = &p->a[p->nExpr-1];
pItem->fg.reusable = regDest<0;
if( regDest<0 ) regDest = ++pParse->nMem;
pItem->u.iConstExprReg = regDest;
}
pParse->pConstExpr = p;
}
return regDest;
}
/*
** Generate code to evaluate an expression and store the results
** into a register. Return the register number where the results
** are stored.
**
** If the register is a temporary register that can be deallocated,
** then write its number into *pReg. If the result register is not
** a temporary, then set *pReg to zero.
**
** If pExpr is a constant, then this routine might generate this
** code to fill the register in the initialization section of the
** VDBE program, in order to factor it out of the evaluation loop.
*/
int sqlite3ExprCodeTemp(Parse *pParse, Expr *pExpr, int *pReg){
int r2;
pExpr = sqlite3ExprSkipCollateAndLikely(pExpr);
if( ConstFactorOk(pParse)
&& ALWAYS(pExpr!=0)
&& pExpr->op!=TK_REGISTER
&& sqlite3ExprIsConstantNotJoin(pParse, pExpr)
){
*pReg = 0;
r2 = sqlite3ExprCodeRunJustOnce(pParse, pExpr, -1);
}else{
int r1 = sqlite3GetTempReg(pParse);
r2 = sqlite3ExprCodeTarget(pParse, pExpr, r1);
if( r2==r1 ){
*pReg = r1;
}else{
sqlite3ReleaseTempReg(pParse, r1);
*pReg = 0;
}
}
return r2;
}
/*
** Generate code that will evaluate expression pExpr and store the
** results in register target. The results are guaranteed to appear
** in register target.
*/
void sqlite3ExprCode(Parse *pParse, Expr *pExpr, int target){
int inReg;
assert( pExpr==0 || !ExprHasVVAProperty(pExpr,EP_Immutable) );
assert( target>0 && target<=pParse->nMem );
assert( pParse->pVdbe!=0 || pParse->db->mallocFailed );
if( pParse->pVdbe==0 ) return;
inReg = sqlite3ExprCodeTarget(pParse, pExpr, target);
if( inReg!=target ){
u8 op;
Expr *pX = sqlite3ExprSkipCollateAndLikely(pExpr);
testcase( pX!=pExpr );
if( ALWAYS(pX)
&& (ExprHasProperty(pX,EP_Subquery) || pX->op==TK_REGISTER)
){
op = OP_Copy;
}else{
op = OP_SCopy;
}
sqlite3VdbeAddOp2(pParse->pVdbe, op, inReg, target);
}
}
/*
** Make a transient copy of expression pExpr and then code it using
** sqlite3ExprCode(). This routine works just like sqlite3ExprCode()
** except that the input expression is guaranteed to be unchanged.
*/
void sqlite3ExprCodeCopy(Parse *pParse, Expr *pExpr, int target){
sqlite3 *db = pParse->db;
pExpr = sqlite3ExprDup(db, pExpr, 0);
if( !db->mallocFailed ) sqlite3ExprCode(pParse, pExpr, target);
sqlite3ExprDelete(db, pExpr);
}
/*
** Generate code that will evaluate expression pExpr and store the
** results in register target. The results are guaranteed to appear
** in register target. If the expression is constant, then this routine
** might choose to code the expression at initialization time.
*/
void sqlite3ExprCodeFactorable(Parse *pParse, Expr *pExpr, int target){
if( pParse->okConstFactor && sqlite3ExprIsConstantNotJoin(pParse,pExpr) ){
sqlite3ExprCodeRunJustOnce(pParse, pExpr, target);
}else{
sqlite3ExprCodeCopy(pParse, pExpr, target);
}
}
/*
** Generate code that pushes the value of every element of the given
** expression list into a sequence of registers beginning at target.
**
** Return the number of elements evaluated. The number returned will
** usually be pList->nExpr but might be reduced if SQLITE_ECEL_OMITREF
** is defined.
**
** The SQLITE_ECEL_DUP flag prevents the arguments from being
** filled using OP_SCopy. OP_Copy must be used instead.
**
** The SQLITE_ECEL_FACTOR argument allows constant arguments to be
** factored out into initialization code.
**
** The SQLITE_ECEL_REF flag means that expressions in the list with
** ExprList.a[].u.x.iOrderByCol>0 have already been evaluated and stored
** in registers at srcReg, and so the value can be copied from there.
** If SQLITE_ECEL_OMITREF is also set, then the values with u.x.iOrderByCol>0
** are simply omitted rather than being copied from srcReg.
*/
int sqlite3ExprCodeExprList(
Parse *pParse, /* Parsing context */
ExprList *pList, /* The expression list to be coded */
int target, /* Where to write results */
int srcReg, /* Source registers if SQLITE_ECEL_REF */
u8 flags /* SQLITE_ECEL_* flags */
){
struct ExprList_item *pItem;
int i, j, n;
u8 copyOp = (flags & SQLITE_ECEL_DUP) ? OP_Copy : OP_SCopy;
Vdbe *v = pParse->pVdbe;
assert( pList!=0 );
assert( target>0 );
assert( pParse->pVdbe!=0 ); /* Never gets this far otherwise */
n = pList->nExpr;
if( !ConstFactorOk(pParse) ) flags &= ~SQLITE_ECEL_FACTOR;
for(pItem=pList->a, i=0; i<n; i++, pItem++){
Expr *pExpr = pItem->pExpr;
#ifdef SQLITE_ENABLE_SORTER_REFERENCES
if( pItem->fg.bSorterRef ){
i--;
n--;
}else
#endif
if( (flags & SQLITE_ECEL_REF)!=0 && (j = pItem->u.x.iOrderByCol)>0 ){
if( flags & SQLITE_ECEL_OMITREF ){
i--;
n--;
}else{
sqlite3VdbeAddOp2(v, copyOp, j+srcReg-1, target+i);
}
}else if( (flags & SQLITE_ECEL_FACTOR)!=0
&& sqlite3ExprIsConstantNotJoin(pParse,pExpr)
){
sqlite3ExprCodeRunJustOnce(pParse, pExpr, target+i);
}else{
int inReg = sqlite3ExprCodeTarget(pParse, pExpr, target+i);
if( inReg!=target+i ){
VdbeOp *pOp;
if( copyOp==OP_Copy
&& (pOp=sqlite3VdbeGetLastOp(v))->opcode==OP_Copy
&& pOp->p1+pOp->p3+1==inReg
&& pOp->p2+pOp->p3+1==target+i
&& pOp->p5==0 /* The do-not-merge flag must be clear */
){
pOp->p3++;
}else{
sqlite3VdbeAddOp2(v, copyOp, inReg, target+i);
}
}
}
}
return n;
}
/*
** Generate code for a BETWEEN operator.
**
** x BETWEEN y AND z
**
** The above is equivalent to
**
** x>=y AND x<=z
**
** Code it as such, taking care to do the common subexpression
** elimination of x.
**
** The xJumpIf parameter determines details:
**
** NULL: Store the boolean result in reg[dest]
** sqlite3ExprIfTrue: Jump to dest if true
** sqlite3ExprIfFalse: Jump to dest if false
**
** The jumpIfNull parameter is ignored if xJumpIf is NULL.
*/
static void exprCodeBetween(
Parse *pParse, /* Parsing and code generating context */
Expr *pExpr, /* The BETWEEN expression */
int dest, /* Jump destination or storage location */
void (*xJump)(Parse*,Expr*,int,int), /* Action to take */
int jumpIfNull /* Take the jump if the BETWEEN is NULL */
){
Expr exprAnd; /* The AND operator in x>=y AND x<=z */
Expr compLeft; /* The x>=y term */
Expr compRight; /* The x<=z term */
int regFree1 = 0; /* Temporary use register */
Expr *pDel = 0;
sqlite3 *db = pParse->db;
memset(&compLeft, 0, sizeof(Expr));
memset(&compRight, 0, sizeof(Expr));
memset(&exprAnd, 0, sizeof(Expr));
assert( ExprUseXList(pExpr) );
pDel = sqlite3ExprDup(db, pExpr->pLeft, 0);
if( db->mallocFailed==0 ){
exprAnd.op = TK_AND;
exprAnd.pLeft = &compLeft;
exprAnd.pRight = &compRight;
compLeft.op = TK_GE;
compLeft.pLeft = pDel;
compLeft.pRight = pExpr->x.pList->a[0].pExpr;
compRight.op = TK_LE;
compRight.pLeft = pDel;
compRight.pRight = pExpr->x.pList->a[1].pExpr;
sqlite3ExprToRegister(pDel, exprCodeVector(pParse, pDel, &regFree1));
if( xJump ){
xJump(pParse, &exprAnd, dest, jumpIfNull);
}else{
/* Mark the expression is being from the ON or USING clause of a join
** so that the sqlite3ExprCodeTarget() routine will not attempt to move
** it into the Parse.pConstExpr list. We should use a new bit for this,
** for clarity, but we are out of bits in the Expr.flags field so we
** have to reuse the EP_OuterON bit. Bummer. */
pDel->flags |= EP_OuterON;
sqlite3ExprCodeTarget(pParse, &exprAnd, dest);
}
sqlite3ReleaseTempReg(pParse, regFree1);
}
sqlite3ExprDelete(db, pDel);
/* Ensure adequate test coverage */
testcase( xJump==sqlite3ExprIfTrue && jumpIfNull==0 && regFree1==0 );
testcase( xJump==sqlite3ExprIfTrue && jumpIfNull==0 && regFree1!=0 );
testcase( xJump==sqlite3ExprIfTrue && jumpIfNull!=0 && regFree1==0 );
testcase( xJump==sqlite3ExprIfTrue && jumpIfNull!=0 && regFree1!=0 );
testcase( xJump==sqlite3ExprIfFalse && jumpIfNull==0 && regFree1==0 );
testcase( xJump==sqlite3ExprIfFalse && jumpIfNull==0 && regFree1!=0 );
testcase( xJump==sqlite3ExprIfFalse && jumpIfNull!=0 && regFree1==0 );
testcase( xJump==sqlite3ExprIfFalse && jumpIfNull!=0 && regFree1!=0 );
testcase( xJump==0 );
}
/*
** Generate code for a boolean expression such that a jump is made
** to the label "dest" if the expression is true but execution
** continues straight thru if the expression is false.
**
** If the expression evaluates to NULL (neither true nor false), then
** take the jump if the jumpIfNull flag is SQLITE_JUMPIFNULL.
**
** This code depends on the fact that certain token values (ex: TK_EQ)
** are the same as opcode values (ex: OP_Eq) that implement the corresponding
** operation. Special comments in vdbe.c and the mkopcodeh.awk script in
** the make process cause these values to align. Assert()s in the code
** below verify that the numbers are aligned correctly.
*/
void sqlite3ExprIfTrue(Parse *pParse, Expr *pExpr, int dest, int jumpIfNull){
Vdbe *v = pParse->pVdbe;
int op = 0;
int regFree1 = 0;
int regFree2 = 0;
int r1, r2;
assert( jumpIfNull==SQLITE_JUMPIFNULL || jumpIfNull==0 );
if( NEVER(v==0) ) return; /* Existence of VDBE checked by caller */
if( NEVER(pExpr==0) ) return; /* No way this can happen */
assert( !ExprHasVVAProperty(pExpr, EP_Immutable) );
op = pExpr->op;
switch( op ){
case TK_AND:
case TK_OR: {
Expr *pAlt = sqlite3ExprSimplifiedAndOr(pExpr);
if( pAlt!=pExpr ){
sqlite3ExprIfTrue(pParse, pAlt, dest, jumpIfNull);
}else if( op==TK_AND ){
int d2 = sqlite3VdbeMakeLabel(pParse);
testcase( jumpIfNull==0 );
sqlite3ExprIfFalse(pParse, pExpr->pLeft, d2,
jumpIfNull^SQLITE_JUMPIFNULL);
sqlite3ExprIfTrue(pParse, pExpr->pRight, dest, jumpIfNull);
sqlite3VdbeResolveLabel(v, d2);
}else{
testcase( jumpIfNull==0 );
sqlite3ExprIfTrue(pParse, pExpr->pLeft, dest, jumpIfNull);
sqlite3ExprIfTrue(pParse, pExpr->pRight, dest, jumpIfNull);
}
break;
}
case TK_NOT: {
testcase( jumpIfNull==0 );
sqlite3ExprIfFalse(pParse, pExpr->pLeft, dest, jumpIfNull);
break;
}
case TK_TRUTH: {
int isNot; /* IS NOT TRUE or IS NOT FALSE */
int isTrue; /* IS TRUE or IS NOT TRUE */
testcase( jumpIfNull==0 );
isNot = pExpr->op2==TK_ISNOT;
isTrue = sqlite3ExprTruthValue(pExpr->pRight);
testcase( isTrue && isNot );
testcase( !isTrue && isNot );
if( isTrue ^ isNot ){
sqlite3ExprIfTrue(pParse, pExpr->pLeft, dest,
isNot ? SQLITE_JUMPIFNULL : 0);
}else{
sqlite3ExprIfFalse(pParse, pExpr->pLeft, dest,
isNot ? SQLITE_JUMPIFNULL : 0);
}
break;
}
case TK_IS:
case TK_ISNOT:
testcase( op==TK_IS );
testcase( op==TK_ISNOT );
op = (op==TK_IS) ? TK_EQ : TK_NE;
jumpIfNull = SQLITE_NULLEQ;
/* no break */ deliberate_fall_through
case TK_LT:
case TK_LE:
case TK_GT:
case TK_GE:
case TK_NE:
case TK_EQ: {
if( sqlite3ExprIsVector(pExpr->pLeft) ) goto default_expr;
testcase( jumpIfNull==0 );
r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, &regFree1);
r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, &regFree2);
codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op,
r1, r2, dest, jumpIfNull, ExprHasProperty(pExpr,EP_Commuted));
assert(TK_LT==OP_Lt); testcase(op==OP_Lt); VdbeCoverageIf(v,op==OP_Lt);
assert(TK_LE==OP_Le); testcase(op==OP_Le); VdbeCoverageIf(v,op==OP_Le);
assert(TK_GT==OP_Gt); testcase(op==OP_Gt); VdbeCoverageIf(v,op==OP_Gt);
assert(TK_GE==OP_Ge); testcase(op==OP_Ge); VdbeCoverageIf(v,op==OP_Ge);
assert(TK_EQ==OP_Eq); testcase(op==OP_Eq);
VdbeCoverageIf(v, op==OP_Eq && jumpIfNull==SQLITE_NULLEQ);
VdbeCoverageIf(v, op==OP_Eq && jumpIfNull!=SQLITE_NULLEQ);
assert(TK_NE==OP_Ne); testcase(op==OP_Ne);
VdbeCoverageIf(v, op==OP_Ne && jumpIfNull==SQLITE_NULLEQ);
VdbeCoverageIf(v, op==OP_Ne && jumpIfNull!=SQLITE_NULLEQ);
testcase( regFree1==0 );
testcase( regFree2==0 );
break;
}
case TK_ISNULL:
case TK_NOTNULL: {
assert( TK_ISNULL==OP_IsNull ); testcase( op==TK_ISNULL );
assert( TK_NOTNULL==OP_NotNull ); testcase( op==TK_NOTNULL );
r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, &regFree1);
sqlite3VdbeTypeofColumn(v, r1);
sqlite3VdbeAddOp2(v, op, r1, dest);
VdbeCoverageIf(v, op==TK_ISNULL);
VdbeCoverageIf(v, op==TK_NOTNULL);
testcase( regFree1==0 );
break;
}
case TK_BETWEEN: {
testcase( jumpIfNull==0 );
exprCodeBetween(pParse, pExpr, dest, sqlite3ExprIfTrue, jumpIfNull);
break;
}
#ifndef SQLITE_OMIT_SUBQUERY
case TK_IN: {
int destIfFalse = sqlite3VdbeMakeLabel(pParse);
int destIfNull = jumpIfNull ? dest : destIfFalse;
sqlite3ExprCodeIN(pParse, pExpr, destIfFalse, destIfNull);
sqlite3VdbeGoto(v, dest);
sqlite3VdbeResolveLabel(v, destIfFalse);
break;
}
#endif
default: {
default_expr:
if( ExprAlwaysTrue(pExpr) ){
sqlite3VdbeGoto(v, dest);
}else if( ExprAlwaysFalse(pExpr) ){
/* No-op */
}else{
r1 = sqlite3ExprCodeTemp(pParse, pExpr, &regFree1);
sqlite3VdbeAddOp3(v, OP_If, r1, dest, jumpIfNull!=0);
VdbeCoverage(v);
testcase( regFree1==0 );
testcase( jumpIfNull==0 );
}
break;
}
}
sqlite3ReleaseTempReg(pParse, regFree1);
sqlite3ReleaseTempReg(pParse, regFree2);
}
/*
** Generate code for a boolean expression such that a jump is made
** to the label "dest" if the expression is false but execution
** continues straight thru if the expression is true.
**
** If the expression evaluates to NULL (neither true nor false) then
** jump if jumpIfNull is SQLITE_JUMPIFNULL or fall through if jumpIfNull
** is 0.
*/
void sqlite3ExprIfFalse(Parse *pParse, Expr *pExpr, int dest, int jumpIfNull){
Vdbe *v = pParse->pVdbe;
int op = 0;
int regFree1 = 0;
int regFree2 = 0;
int r1, r2;
assert( jumpIfNull==SQLITE_JUMPIFNULL || jumpIfNull==0 );
if( NEVER(v==0) ) return; /* Existence of VDBE checked by caller */
if( pExpr==0 ) return;
assert( !ExprHasVVAProperty(pExpr,EP_Immutable) );
/* The value of pExpr->op and op are related as follows:
**
** pExpr->op op
** --------- ----------
** TK_ISNULL OP_NotNull
** TK_NOTNULL OP_IsNull
** TK_NE OP_Eq
** TK_EQ OP_Ne
** TK_GT OP_Le
** TK_LE OP_Gt
** TK_GE OP_Lt
** TK_LT OP_Ge
**
** For other values of pExpr->op, op is undefined and unused.
** The value of TK_ and OP_ constants are arranged such that we
** can compute the mapping above using the following expression.
** Assert()s verify that the computation is correct.
*/
op = ((pExpr->op+(TK_ISNULL&1))^1)-(TK_ISNULL&1);
/* Verify correct alignment of TK_ and OP_ constants
*/
assert( pExpr->op!=TK_ISNULL || op==OP_NotNull );
assert( pExpr->op!=TK_NOTNULL || op==OP_IsNull );
assert( pExpr->op!=TK_NE || op==OP_Eq );
assert( pExpr->op!=TK_EQ || op==OP_Ne );
assert( pExpr->op!=TK_LT || op==OP_Ge );
assert( pExpr->op!=TK_LE || op==OP_Gt );
assert( pExpr->op!=TK_GT || op==OP_Le );
assert( pExpr->op!=TK_GE || op==OP_Lt );
switch( pExpr->op ){
case TK_AND:
case TK_OR: {
Expr *pAlt = sqlite3ExprSimplifiedAndOr(pExpr);
if( pAlt!=pExpr ){
sqlite3ExprIfFalse(pParse, pAlt, dest, jumpIfNull);
}else if( pExpr->op==TK_AND ){
testcase( jumpIfNull==0 );
sqlite3ExprIfFalse(pParse, pExpr->pLeft, dest, jumpIfNull);
sqlite3ExprIfFalse(pParse, pExpr->pRight, dest, jumpIfNull);
}else{
int d2 = sqlite3VdbeMakeLabel(pParse);
testcase( jumpIfNull==0 );
sqlite3ExprIfTrue(pParse, pExpr->pLeft, d2,
jumpIfNull^SQLITE_JUMPIFNULL);
sqlite3ExprIfFalse(pParse, pExpr->pRight, dest, jumpIfNull);
sqlite3VdbeResolveLabel(v, d2);
}
break;
}
case TK_NOT: {
testcase( jumpIfNull==0 );
sqlite3ExprIfTrue(pParse, pExpr->pLeft, dest, jumpIfNull);
break;
}
case TK_TRUTH: {
int isNot; /* IS NOT TRUE or IS NOT FALSE */
int isTrue; /* IS TRUE or IS NOT TRUE */
testcase( jumpIfNull==0 );
isNot = pExpr->op2==TK_ISNOT;
isTrue = sqlite3ExprTruthValue(pExpr->pRight);
testcase( isTrue && isNot );
testcase( !isTrue && isNot );
if( isTrue ^ isNot ){
/* IS TRUE and IS NOT FALSE */
sqlite3ExprIfFalse(pParse, pExpr->pLeft, dest,
isNot ? 0 : SQLITE_JUMPIFNULL);
}else{
/* IS FALSE and IS NOT TRUE */
sqlite3ExprIfTrue(pParse, pExpr->pLeft, dest,
isNot ? 0 : SQLITE_JUMPIFNULL);
}
break;
}
case TK_IS:
case TK_ISNOT:
testcase( pExpr->op==TK_IS );
testcase( pExpr->op==TK_ISNOT );
op = (pExpr->op==TK_IS) ? TK_NE : TK_EQ;
jumpIfNull = SQLITE_NULLEQ;
/* no break */ deliberate_fall_through
case TK_LT:
case TK_LE:
case TK_GT:
case TK_GE:
case TK_NE:
case TK_EQ: {
if( sqlite3ExprIsVector(pExpr->pLeft) ) goto default_expr;
testcase( jumpIfNull==0 );
r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, &regFree1);
r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, &regFree2);
codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op,
r1, r2, dest, jumpIfNull,ExprHasProperty(pExpr,EP_Commuted));
assert(TK_LT==OP_Lt); testcase(op==OP_Lt); VdbeCoverageIf(v,op==OP_Lt);
assert(TK_LE==OP_Le); testcase(op==OP_Le); VdbeCoverageIf(v,op==OP_Le);
assert(TK_GT==OP_Gt); testcase(op==OP_Gt); VdbeCoverageIf(v,op==OP_Gt);
assert(TK_GE==OP_Ge); testcase(op==OP_Ge); VdbeCoverageIf(v,op==OP_Ge);
assert(TK_EQ==OP_Eq); testcase(op==OP_Eq);
VdbeCoverageIf(v, op==OP_Eq && jumpIfNull!=SQLITE_NULLEQ);
VdbeCoverageIf(v, op==OP_Eq && jumpIfNull==SQLITE_NULLEQ);
assert(TK_NE==OP_Ne); testcase(op==OP_Ne);
VdbeCoverageIf(v, op==OP_Ne && jumpIfNull!=SQLITE_NULLEQ);
VdbeCoverageIf(v, op==OP_Ne && jumpIfNull==SQLITE_NULLEQ);
testcase( regFree1==0 );
testcase( regFree2==0 );
break;
}
case TK_ISNULL:
case TK_NOTNULL: {
r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, &regFree1);
sqlite3VdbeTypeofColumn(v, r1);
sqlite3VdbeAddOp2(v, op, r1, dest);
testcase( op==TK_ISNULL ); VdbeCoverageIf(v, op==TK_ISNULL);
testcase( op==TK_NOTNULL ); VdbeCoverageIf(v, op==TK_NOTNULL);
testcase( regFree1==0 );
break;
}
case TK_BETWEEN: {
testcase( jumpIfNull==0 );
exprCodeBetween(pParse, pExpr, dest, sqlite3ExprIfFalse, jumpIfNull);
break;
}
#ifndef SQLITE_OMIT_SUBQUERY
case TK_IN: {
if( jumpIfNull ){
sqlite3ExprCodeIN(pParse, pExpr, dest, dest);
}else{
int destIfNull = sqlite3VdbeMakeLabel(pParse);
sqlite3ExprCodeIN(pParse, pExpr, dest, destIfNull);
sqlite3VdbeResolveLabel(v, destIfNull);
}
break;
}
#endif
default: {
default_expr:
if( ExprAlwaysFalse(pExpr) ){
sqlite3VdbeGoto(v, dest);
}else if( ExprAlwaysTrue(pExpr) ){
/* no-op */
}else{
r1 = sqlite3ExprCodeTemp(pParse, pExpr, &regFree1);
sqlite3VdbeAddOp3(v, OP_IfNot, r1, dest, jumpIfNull!=0);
VdbeCoverage(v);
testcase( regFree1==0 );
testcase( jumpIfNull==0 );
}
break;
}
}
sqlite3ReleaseTempReg(pParse, regFree1);
sqlite3ReleaseTempReg(pParse, regFree2);
}
/*
** Like sqlite3ExprIfFalse() except that a copy is made of pExpr before
** code generation, and that copy is deleted after code generation. This
** ensures that the original pExpr is unchanged.
*/
void sqlite3ExprIfFalseDup(Parse *pParse, Expr *pExpr, int dest,int jumpIfNull){
sqlite3 *db = pParse->db;
Expr *pCopy = sqlite3ExprDup(db, pExpr, 0);
if( db->mallocFailed==0 ){
sqlite3ExprIfFalse(pParse, pCopy, dest, jumpIfNull);
}
sqlite3ExprDelete(db, pCopy);
}
/*
** Expression pVar is guaranteed to be an SQL variable. pExpr may be any
** type of expression.
**
** If pExpr is a simple SQL value - an integer, real, string, blob
** or NULL value - then the VDBE currently being prepared is configured
** to re-prepare each time a new value is bound to variable pVar.
**
** Additionally, if pExpr is a simple SQL value and the value is the
** same as that currently bound to variable pVar, non-zero is returned.
** Otherwise, if the values are not the same or if pExpr is not a simple
** SQL value, zero is returned.
*/
static int exprCompareVariable(
const Parse *pParse,
const Expr *pVar,
const Expr *pExpr
){
int res = 0;
int iVar;
sqlite3_value *pL, *pR = 0;
sqlite3ValueFromExpr(pParse->db, pExpr, SQLITE_UTF8, SQLITE_AFF_BLOB, &pR);
if( pR ){
iVar = pVar->iColumn;
sqlite3VdbeSetVarmask(pParse->pVdbe, iVar);
pL = sqlite3VdbeGetBoundValue(pParse->pReprepare, iVar, SQLITE_AFF_BLOB);
if( pL ){
if( sqlite3_value_type(pL)==SQLITE_TEXT ){
sqlite3_value_text(pL); /* Make sure the encoding is UTF-8 */
}
res = 0==sqlite3MemCompare(pL, pR, 0);
}
sqlite3ValueFree(pR);
sqlite3ValueFree(pL);
}
return res;
}
/*
** Do a deep comparison of two expression trees. Return 0 if the two
** expressions are completely identical. Return 1 if they differ only
** by a COLLATE operator at the top level. Return 2 if there are differences
** other than the top-level COLLATE operator.
**
** If any subelement of pB has Expr.iTable==(-1) then it is allowed
** to compare equal to an equivalent element in pA with Expr.iTable==iTab.
**
** The pA side might be using TK_REGISTER. If that is the case and pB is
** not using TK_REGISTER but is otherwise equivalent, then still return 0.
**
** Sometimes this routine will return 2 even if the two expressions
** really are equivalent. If we cannot prove that the expressions are
** identical, we return 2 just to be safe. So if this routine
** returns 2, then you do not really know for certain if the two
** expressions are the same. But if you get a 0 or 1 return, then you
** can be sure the expressions are the same. In the places where
** this routine is used, it does not hurt to get an extra 2 - that
** just might result in some slightly slower code. But returning
** an incorrect 0 or 1 could lead to a malfunction.
**
** If pParse is not NULL then TK_VARIABLE terms in pA with bindings in
** pParse->pReprepare can be matched against literals in pB. The
** pParse->pVdbe->expmask bitmask is updated for each variable referenced.
** If pParse is NULL (the normal case) then any TK_VARIABLE term in
** Argument pParse should normally be NULL. If it is not NULL and pA or
** pB causes a return value of 2.
*/
int sqlite3ExprCompare(
const Parse *pParse,
const Expr *pA,
const Expr *pB,
int iTab
){
u32 combinedFlags;
if( pA==0 || pB==0 ){
return pB==pA ? 0 : 2;
}
if( pParse && pA->op==TK_VARIABLE && exprCompareVariable(pParse, pA, pB) ){
return 0;
}
combinedFlags = pA->flags | pB->flags;
if( combinedFlags & EP_IntValue ){
if( (pA->flags&pB->flags&EP_IntValue)!=0 && pA->u.iValue==pB->u.iValue ){
return 0;
}
return 2;
}
if( pA->op!=pB->op || pA->op==TK_RAISE ){
if( pA->op==TK_COLLATE && sqlite3ExprCompare(pParse, pA->pLeft,pB,iTab)<2 ){
return 1;
}
if( pB->op==TK_COLLATE && sqlite3ExprCompare(pParse, pA,pB->pLeft,iTab)<2 ){
return 1;
}
if( pA->op==TK_AGG_COLUMN && pB->op==TK_COLUMN
&& pB->iTable<0 && pA->iTable==iTab
){
/* fall through */
}else{
return 2;
}
}
assert( !ExprHasProperty(pA, EP_IntValue) );
assert( !ExprHasProperty(pB, EP_IntValue) );
if( pA->u.zToken ){
if( pA->op==TK_FUNCTION || pA->op==TK_AGG_FUNCTION ){
if( sqlite3StrICmp(pA->u.zToken,pB->u.zToken)!=0 ) return 2;
#ifndef SQLITE_OMIT_WINDOWFUNC
assert( pA->op==pB->op );
if( ExprHasProperty(pA,EP_WinFunc)!=ExprHasProperty(pB,EP_WinFunc) ){
return 2;
}
if( ExprHasProperty(pA,EP_WinFunc) ){
if( sqlite3WindowCompare(pParse, pA->y.pWin, pB->y.pWin, 1)!=0 ){
return 2;
}
}
#endif
}else if( pA->op==TK_NULL ){
return 0;
}else if( pA->op==TK_COLLATE ){
if( sqlite3_stricmp(pA->u.zToken,pB->u.zToken)!=0 ) return 2;
}else
if( pB->u.zToken!=0
&& pA->op!=TK_COLUMN
&& pA->op!=TK_AGG_COLUMN
&& strcmp(pA->u.zToken,pB->u.zToken)!=0
){
return 2;
}
}
if( (pA->flags & (EP_Distinct|EP_Commuted))
!= (pB->flags & (EP_Distinct|EP_Commuted)) ) return 2;
if( ALWAYS((combinedFlags & EP_TokenOnly)==0) ){
if( combinedFlags & EP_xIsSelect ) return 2;
if( (combinedFlags & EP_FixedCol)==0
&& sqlite3ExprCompare(pParse, pA->pLeft, pB->pLeft, iTab) ) return 2;
if( sqlite3ExprCompare(pParse, pA->pRight, pB->pRight, iTab) ) return 2;
if( sqlite3ExprListCompare(pA->x.pList, pB->x.pList, iTab) ) return 2;
if( pA->op!=TK_STRING
&& pA->op!=TK_TRUEFALSE
&& ALWAYS((combinedFlags & EP_Reduced)==0)
){
if( pA->iColumn!=pB->iColumn ) return 2;
if( pA->op2!=pB->op2 && pA->op==TK_TRUTH ) return 2;
if( pA->op!=TK_IN && pA->iTable!=pB->iTable && pA->iTable!=iTab ){
return 2;
}
}
}
return 0;
}
/*
** Compare two ExprList objects. Return 0 if they are identical, 1
** if they are certainly different, or 2 if it is not possible to
** determine if they are identical or not.
**
** If any subelement of pB has Expr.iTable==(-1) then it is allowed
** to compare equal to an equivalent element in pA with Expr.iTable==iTab.
**
** This routine might return non-zero for equivalent ExprLists. The
** only consequence will be disabled optimizations. But this routine
** must never return 0 if the two ExprList objects are different, or
** a malfunction will result.
**
** Two NULL pointers are considered to be the same. But a NULL pointer
** always differs from a non-NULL pointer.
*/
int sqlite3ExprListCompare(const ExprList *pA, const ExprList *pB, int iTab){
int i;
if( pA==0 && pB==0 ) return 0;
if( pA==0 || pB==0 ) return 1;
if( pA->nExpr!=pB->nExpr ) return 1;
for(i=0; i<pA->nExpr; i++){
int res;
Expr *pExprA = pA->a[i].pExpr;
Expr *pExprB = pB->a[i].pExpr;
if( pA->a[i].fg.sortFlags!=pB->a[i].fg.sortFlags ) return 1;
if( (res = sqlite3ExprCompare(0, pExprA, pExprB, iTab)) ) return res;
}
return 0;
}
/*
** Like sqlite3ExprCompare() except COLLATE operators at the top-level
** are ignored.
*/
int sqlite3ExprCompareSkip(Expr *pA,Expr *pB, int iTab){
return sqlite3ExprCompare(0,
sqlite3ExprSkipCollate(pA),
sqlite3ExprSkipCollate(pB),
iTab);
}
/*
** Return non-zero if Expr p can only be true if pNN is not NULL.
**
** Or if seenNot is true, return non-zero if Expr p can only be
** non-NULL if pNN is not NULL
*/
static int exprImpliesNotNull(
const Parse *pParse,/* Parsing context */
const Expr *p, /* The expression to be checked */
const Expr *pNN, /* The expression that is NOT NULL */
int iTab, /* Table being evaluated */
int seenNot /* Return true only if p can be any non-NULL value */
){
assert( p );
assert( pNN );
if( sqlite3ExprCompare(pParse, p, pNN, iTab)==0 ){
return pNN->op!=TK_NULL;
}
switch( p->op ){
case TK_IN: {
if( seenNot && ExprHasProperty(p, EP_xIsSelect) ) return 0;
assert( ExprUseXSelect(p) || (p->x.pList!=0 && p->x.pList->nExpr>0) );
return exprImpliesNotNull(pParse, p->pLeft, pNN, iTab, 1);
}
case TK_BETWEEN: {
ExprList *pList;
assert( ExprUseXList(p) );
pList = p->x.pList;
assert( pList!=0 );
assert( pList->nExpr==2 );
if( seenNot ) return 0;
if( exprImpliesNotNull(pParse, pList->a[0].pExpr, pNN, iTab, 1)
|| exprImpliesNotNull(pParse, pList->a[1].pExpr, pNN, iTab, 1)
){
return 1;
}
return exprImpliesNotNull(pParse, p->pLeft, pNN, iTab, 1);
}
case TK_EQ:
case TK_NE:
case TK_LT:
case TK_LE:
case TK_GT:
case TK_GE:
case TK_PLUS:
case TK_MINUS:
case TK_BITOR:
case TK_LSHIFT:
case TK_RSHIFT:
case TK_CONCAT:
seenNot = 1;
/* no break */ deliberate_fall_through
case TK_STAR:
case TK_REM:
case TK_BITAND:
case TK_SLASH: {
if( exprImpliesNotNull(pParse, p->pRight, pNN, iTab, seenNot) ) return 1;
/* no break */ deliberate_fall_through
}
case TK_SPAN:
case TK_COLLATE:
case TK_UPLUS:
case TK_UMINUS: {
return exprImpliesNotNull(pParse, p->pLeft, pNN, iTab, seenNot);
}
case TK_TRUTH: {
if( seenNot ) return 0;
if( p->op2!=TK_IS ) return 0;
return exprImpliesNotNull(pParse, p->pLeft, pNN, iTab, 1);
}
case TK_BITNOT:
case TK_NOT: {
return exprImpliesNotNull(pParse, p->pLeft, pNN, iTab, 1);
}
}
return 0;
}
/*
** Return true if we can prove the pE2 will always be true if pE1 is
** true. Return false if we cannot complete the proof or if pE2 might
** be false. Examples:
**
** pE1: x==5 pE2: x==5 Result: true
** pE1: x>0 pE2: x==5 Result: false
** pE1: x=21 pE2: x=21 OR y=43 Result: true
** pE1: x!=123 pE2: x IS NOT NULL Result: true
** pE1: x!=?1 pE2: x IS NOT NULL Result: true
** pE1: x IS NULL pE2: x IS NOT NULL Result: false
** pE1: x IS ?2 pE2: x IS NOT NULL Result: false
**
** When comparing TK_COLUMN nodes between pE1 and pE2, if pE2 has
** Expr.iTable<0 then assume a table number given by iTab.
**
** If pParse is not NULL, then the values of bound variables in pE1 are
** compared against literal values in pE2 and pParse->pVdbe->expmask is
** modified to record which bound variables are referenced. If pParse
** is NULL, then false will be returned if pE1 contains any bound variables.
**
** When in doubt, return false. Returning true might give a performance
** improvement. Returning false might cause a performance reduction, but
** it will always give the correct answer and is hence always safe.
*/
int sqlite3ExprImpliesExpr(
const Parse *pParse,
const Expr *pE1,
const Expr *pE2,
int iTab
){
if( sqlite3ExprCompare(pParse, pE1, pE2, iTab)==0 ){
return 1;
}
if( pE2->op==TK_OR
&& (sqlite3ExprImpliesExpr(pParse, pE1, pE2->pLeft, iTab)
|| sqlite3ExprImpliesExpr(pParse, pE1, pE2->pRight, iTab) )
){
return 1;
}
if( pE2->op==TK_NOTNULL
&& exprImpliesNotNull(pParse, pE1, pE2->pLeft, iTab, 0)
){
return 1;
}
return 0;
}
/* This is a helper function to impliesNotNullRow(). In this routine,
** set pWalker->eCode to one only if *both* of the input expressions
** separately have the implies-not-null-row property.
*/
static void bothImplyNotNullRow(Walker *pWalker, Expr *pE1, Expr *pE2){
if( pWalker->eCode==0 ){
sqlite3WalkExpr(pWalker, pE1);
if( pWalker->eCode ){
pWalker->eCode = 0;
sqlite3WalkExpr(pWalker, pE2);
}
}
}
/*
** This is the Expr node callback for sqlite3ExprImpliesNonNullRow().
** If the expression node requires that the table at pWalker->iCur
** have one or more non-NULL column, then set pWalker->eCode to 1 and abort.
**
** pWalker->mWFlags is non-zero if this inquiry is being undertaking on
** behalf of a RIGHT JOIN (or FULL JOIN). That makes a difference when
** evaluating terms in the ON clause of an inner join.
**
** This routine controls an optimization. False positives (setting
** pWalker->eCode to 1 when it should not be) are deadly, but false-negatives
** (never setting pWalker->eCode) is a harmless missed optimization.
*/
static int impliesNotNullRow(Walker *pWalker, Expr *pExpr){
testcase( pExpr->op==TK_AGG_COLUMN );
testcase( pExpr->op==TK_AGG_FUNCTION );
if( ExprHasProperty(pExpr, EP_OuterON) ) return WRC_Prune;
if( ExprHasProperty(pExpr, EP_InnerON) && pWalker->mWFlags ){
/* If iCur is used in an inner-join ON clause to the left of a
** RIGHT JOIN, that does *not* mean that the table must be non-null.
** But it is difficult to check for that condition precisely.
** To keep things simple, any use of iCur from any inner-join is
** ignored while attempting to simplify a RIGHT JOIN. */
return WRC_Prune;
}
switch( pExpr->op ){
case TK_ISNOT:
case TK_ISNULL:
case TK_NOTNULL:
case TK_IS:
case TK_VECTOR:
case TK_FUNCTION:
case TK_TRUTH:
case TK_CASE:
testcase( pExpr->op==TK_ISNOT );
testcase( pExpr->op==TK_ISNULL );
testcase( pExpr->op==TK_NOTNULL );
testcase( pExpr->op==TK_IS );
testcase( pExpr->op==TK_VECTOR );
testcase( pExpr->op==TK_FUNCTION );
testcase( pExpr->op==TK_TRUTH );
testcase( pExpr->op==TK_CASE );
return WRC_Prune;
case TK_COLUMN:
if( pWalker->u.iCur==pExpr->iTable ){
pWalker->eCode = 1;
return WRC_Abort;
}
return WRC_Prune;
case TK_OR:
case TK_AND:
/* Both sides of an AND or OR must separately imply non-null-row.
** Consider these cases:
** 1. NOT (x AND y)
** 2. x OR y
** If only one of x or y is non-null-row, then the overall expression
** can be true if the other arm is false (case 1) or true (case 2).
*/
testcase( pExpr->op==TK_OR );
testcase( pExpr->op==TK_AND );
bothImplyNotNullRow(pWalker, pExpr->pLeft, pExpr->pRight);
return WRC_Prune;
case TK_IN:
/* Beware of "x NOT IN ()" and "x NOT IN (SELECT 1 WHERE false)",
** both of which can be true. But apart from these cases, if
** the left-hand side of the IN is NULL then the IN itself will be
** NULL. */
if( ExprUseXList(pExpr) && ALWAYS(pExpr->x.pList->nExpr>0) ){
sqlite3WalkExpr(pWalker, pExpr->pLeft);
}
return WRC_Prune;
case TK_BETWEEN:
/* In "x NOT BETWEEN y AND z" either x must be non-null-row or else
** both y and z must be non-null row */
assert( ExprUseXList(pExpr) );
assert( pExpr->x.pList->nExpr==2 );
sqlite3WalkExpr(pWalker, pExpr->pLeft);
bothImplyNotNullRow(pWalker, pExpr->x.pList->a[0].pExpr,
pExpr->x.pList->a[1].pExpr);
return WRC_Prune;
/* Virtual tables are allowed to use constraints like x=NULL. So
** a term of the form x=y does not prove that y is not null if x
** is the column of a virtual table */
case TK_EQ:
case TK_NE:
case TK_LT:
case TK_LE:
case TK_GT:
case TK_GE: {
Expr *pLeft = pExpr->pLeft;
Expr *pRight = pExpr->pRight;
testcase( pExpr->op==TK_EQ );
testcase( pExpr->op==TK_NE );
testcase( pExpr->op==TK_LT );
testcase( pExpr->op==TK_LE );
testcase( pExpr->op==TK_GT );
testcase( pExpr->op==TK_GE );
/* The y.pTab=0 assignment in wherecode.c always happens after the
** impliesNotNullRow() test */
assert( pLeft->op!=TK_COLUMN || ExprUseYTab(pLeft) );
assert( pRight->op!=TK_COLUMN || ExprUseYTab(pRight) );
if( (pLeft->op==TK_COLUMN
&& ALWAYS(pLeft->y.pTab!=0)
&& IsVirtual(pLeft->y.pTab))
|| (pRight->op==TK_COLUMN
&& ALWAYS(pRight->y.pTab!=0)
&& IsVirtual(pRight->y.pTab))
){
return WRC_Prune;
}
/* no break */ deliberate_fall_through
}
default:
return WRC_Continue;
}
}
/*
** Return true (non-zero) if expression p can only be true if at least
** one column of table iTab is non-null. In other words, return true
** if expression p will always be NULL or false if every column of iTab
** is NULL.
**
** False negatives are acceptable. In other words, it is ok to return
** zero even if expression p will never be true of every column of iTab
** is NULL. A false negative is merely a missed optimization opportunity.
**
** False positives are not allowed, however. A false positive may result
** in an incorrect answer.
**
** Terms of p that are marked with EP_OuterON (and hence that come from
** the ON or USING clauses of OUTER JOINS) are excluded from the analysis.
**
** This routine is used to check if a LEFT JOIN can be converted into
** an ordinary JOIN. The p argument is the WHERE clause. If the WHERE
** clause requires that some column of the right table of the LEFT JOIN
** be non-NULL, then the LEFT JOIN can be safely converted into an
** ordinary join.
*/
int sqlite3ExprImpliesNonNullRow(Expr *p, int iTab, int isRJ){
Walker w;
p = sqlite3ExprSkipCollateAndLikely(p);
if( p==0 ) return 0;
if( p->op==TK_NOTNULL ){
p = p->pLeft;
}else{
while( p->op==TK_AND ){
if( sqlite3ExprImpliesNonNullRow(p->pLeft, iTab, isRJ) ) return 1;
p = p->pRight;
}
}
w.xExprCallback = impliesNotNullRow;
w.xSelectCallback = 0;
w.xSelectCallback2 = 0;
w.eCode = 0;
w.mWFlags = isRJ!=0;
w.u.iCur = iTab;
sqlite3WalkExpr(&w, p);
return w.eCode;
}
/*
** An instance of the following structure is used by the tree walker
** to determine if an expression can be evaluated by reference to the
** index only, without having to do a search for the corresponding
** table entry. The IdxCover.pIdx field is the index. IdxCover.iCur
** is the cursor for the table.
*/
struct IdxCover {
Index *pIdx; /* The index to be tested for coverage */
int iCur; /* Cursor number for the table corresponding to the index */
};
/*
** Check to see if there are references to columns in table
** pWalker->u.pIdxCover->iCur can be satisfied using the index
** pWalker->u.pIdxCover->pIdx.
*/
static int exprIdxCover(Walker *pWalker, Expr *pExpr){
if( pExpr->op==TK_COLUMN
&& pExpr->iTable==pWalker->u.pIdxCover->iCur
&& sqlite3TableColumnToIndex(pWalker->u.pIdxCover->pIdx, pExpr->iColumn)<0
){
pWalker->eCode = 1;
return WRC_Abort;
}
return WRC_Continue;
}
/*
** Determine if an index pIdx on table with cursor iCur contains will
** the expression pExpr. Return true if the index does cover the
** expression and false if the pExpr expression references table columns
** that are not found in the index pIdx.
**
** An index covering an expression means that the expression can be
** evaluated using only the index and without having to lookup the
** corresponding table entry.
*/
int sqlite3ExprCoveredByIndex(
Expr *pExpr, /* The index to be tested */
int iCur, /* The cursor number for the corresponding table */
Index *pIdx /* The index that might be used for coverage */
){
Walker w;
struct IdxCover xcov;
memset(&w, 0, sizeof(w));
xcov.iCur = iCur;
xcov.pIdx = pIdx;
w.xExprCallback = exprIdxCover;
w.u.pIdxCover = &xcov;
sqlite3WalkExpr(&w, pExpr);
return !w.eCode;
}
/* Structure used to pass information throughout the Walker in order to
** implement sqlite3ReferencesSrcList().
*/
struct RefSrcList {
sqlite3 *db; /* Database connection used for sqlite3DbRealloc() */
SrcList *pRef; /* Looking for references to these tables */
i64 nExclude; /* Number of tables to exclude from the search */
int *aiExclude; /* Cursor IDs for tables to exclude from the search */
};
/*
** Walker SELECT callbacks for sqlite3ReferencesSrcList().
**
** When entering a new subquery on the pExpr argument, add all FROM clause
** entries for that subquery to the exclude list.
**
** When leaving the subquery, remove those entries from the exclude list.
*/
static int selectRefEnter(Walker *pWalker, Select *pSelect){
struct RefSrcList *p = pWalker->u.pRefSrcList;
SrcList *pSrc = pSelect->pSrc;
i64 i, j;
int *piNew;
if( pSrc->nSrc==0 ) return WRC_Continue;
j = p->nExclude;
p->nExclude += pSrc->nSrc;
piNew = sqlite3DbRealloc(p->db, p->aiExclude, p->nExclude*sizeof(int));
if( piNew==0 ){
p->nExclude = 0;
return WRC_Abort;
}else{
p->aiExclude = piNew;
}
for(i=0; i<pSrc->nSrc; i++, j++){
p->aiExclude[j] = pSrc->a[i].iCursor;
}
return WRC_Continue;
}
static void selectRefLeave(Walker *pWalker, Select *pSelect){
struct RefSrcList *p = pWalker->u.pRefSrcList;
SrcList *pSrc = pSelect->pSrc;
if( p->nExclude ){
assert( p->nExclude>=pSrc->nSrc );
p->nExclude -= pSrc->nSrc;
}
}
/* This is the Walker EXPR callback for sqlite3ReferencesSrcList().
**
** Set the 0x01 bit of pWalker->eCode if there is a reference to any
** of the tables shown in RefSrcList.pRef.
**
** Set the 0x02 bit of pWalker->eCode if there is a reference to a
** table is in neither RefSrcList.pRef nor RefSrcList.aiExclude.
*/
static int exprRefToSrcList(Walker *pWalker, Expr *pExpr){
if( pExpr->op==TK_COLUMN
|| pExpr->op==TK_AGG_COLUMN
){
int i;
struct RefSrcList *p = pWalker->u.pRefSrcList;
SrcList *pSrc = p->pRef;
int nSrc = pSrc ? pSrc->nSrc : 0;
for(i=0; i<nSrc; i++){
if( pExpr->iTable==pSrc->a[i].iCursor ){
pWalker->eCode |= 1;
return WRC_Continue;
}
}
for(i=0; i<p->nExclude && p->aiExclude[i]!=pExpr->iTable; i++){}
if( i>=p->nExclude ){
pWalker->eCode |= 2;
}
}
return WRC_Continue;
}
/*
** Check to see if pExpr references any tables in pSrcList.
** Possible return values:
**
** 1 pExpr does references a table in pSrcList.
**
** 0 pExpr references some table that is not defined in either
** pSrcList or in subqueries of pExpr itself.
**
** -1 pExpr only references no tables at all, or it only
** references tables defined in subqueries of pExpr itself.
**
** As currently used, pExpr is always an aggregate function call. That
** fact is exploited for efficiency.
*/
int sqlite3ReferencesSrcList(Parse *pParse, Expr *pExpr, SrcList *pSrcList){
Walker w;
struct RefSrcList x;
assert( pParse->db!=0 );
memset(&w, 0, sizeof(w));
memset(&x, 0, sizeof(x));
w.xExprCallback = exprRefToSrcList;
w.xSelectCallback = selectRefEnter;
w.xSelectCallback2 = selectRefLeave;
w.u.pRefSrcList = &x;
x.db = pParse->db;
x.pRef = pSrcList;
assert( pExpr->op==TK_AGG_FUNCTION );
assert( ExprUseXList(pExpr) );
sqlite3WalkExprList(&w, pExpr->x.pList);
if( pExpr->pLeft ){
assert( pExpr->pLeft->op==TK_ORDER );
assert( ExprUseXList(pExpr->pLeft) );
assert( pExpr->pLeft->x.pList!=0 );
sqlite3WalkExprList(&w, pExpr->pLeft->x.pList);
}
#ifndef SQLITE_OMIT_WINDOWFUNC
if( ExprHasProperty(pExpr, EP_WinFunc) ){
sqlite3WalkExpr(&w, pExpr->y.pWin->pFilter);
}
#endif
if( x.aiExclude ) sqlite3DbNNFreeNN(pParse->db, x.aiExclude);
if( w.eCode & 0x01 ){
return 1;
}else if( w.eCode ){
return 0;
}else{
return -1;
}
}
/*
** This is a Walker expression node callback.
**
** For Expr nodes that contain pAggInfo pointers, make sure the AggInfo
** object that is referenced does not refer directly to the Expr. If
** it does, make a copy. This is done because the pExpr argument is
** subject to change.
**
** The copy is scheduled for deletion using the sqlite3ExprDeferredDelete()
** which builds on the sqlite3ParserAddCleanup() mechanism.
*/
static int agginfoPersistExprCb(Walker *pWalker, Expr *pExpr){
if( ALWAYS(!ExprHasProperty(pExpr, EP_TokenOnly|EP_Reduced))
&& pExpr->pAggInfo!=0
){
AggInfo *pAggInfo = pExpr->pAggInfo;
int iAgg = pExpr->iAgg;
Parse *pParse = pWalker->pParse;
sqlite3 *db = pParse->db;
assert( iAgg>=0 );
if( pExpr->op!=TK_AGG_FUNCTION ){
if( iAgg<pAggInfo->nColumn
&& pAggInfo->aCol[iAgg].pCExpr==pExpr
){
pExpr = sqlite3ExprDup(db, pExpr, 0);
if( pExpr && !sqlite3ExprDeferredDelete(pParse, pExpr) ){
pAggInfo->aCol[iAgg].pCExpr = pExpr;
}
}
}else{
assert( pExpr->op==TK_AGG_FUNCTION );
if( ALWAYS(iAgg<pAggInfo->nFunc)
&& pAggInfo->aFunc[iAgg].pFExpr==pExpr
){
pExpr = sqlite3ExprDup(db, pExpr, 0);
if( pExpr && !sqlite3ExprDeferredDelete(pParse, pExpr) ){
pAggInfo->aFunc[iAgg].pFExpr = pExpr;
}
}
}
}
return WRC_Continue;
}
/*
** Initialize a Walker object so that will persist AggInfo entries referenced
** by the tree that is walked.
*/
void sqlite3AggInfoPersistWalkerInit(Walker *pWalker, Parse *pParse){
memset(pWalker, 0, sizeof(*pWalker));
pWalker->pParse = pParse;
pWalker->xExprCallback = agginfoPersistExprCb;
pWalker->xSelectCallback = sqlite3SelectWalkNoop;
}
/*
** Add a new element to the pAggInfo->aCol[] array. Return the index of
** the new element. Return a negative number if malloc fails.
*/
static int addAggInfoColumn(sqlite3 *db, AggInfo *pInfo){
int i;
pInfo->aCol = sqlite3ArrayAllocate(
db,
pInfo->aCol,
sizeof(pInfo->aCol[0]),
&pInfo->nColumn,
&i
);
return i;
}
/*
** Add a new element to the pAggInfo->aFunc[] array. Return the index of
** the new element. Return a negative number if malloc fails.
*/
static int addAggInfoFunc(sqlite3 *db, AggInfo *pInfo){
int i;
pInfo->aFunc = sqlite3ArrayAllocate(
db,
pInfo->aFunc,
sizeof(pInfo->aFunc[0]),
&pInfo->nFunc,
&i
);
return i;
}
/*
** Search the AggInfo object for an aCol[] entry that has iTable and iColumn.
** Return the index in aCol[] of the entry that describes that column.
**
** If no prior entry is found, create a new one and return -1. The
** new column will have an index of pAggInfo->nColumn-1.
*/
static void findOrCreateAggInfoColumn(
Parse *pParse, /* Parsing context */
AggInfo *pAggInfo, /* The AggInfo object to search and/or modify */
Expr *pExpr /* Expr describing the column to find or insert */
){
struct AggInfo_col *pCol;
int k;
assert( pAggInfo->iFirstReg==0 );
pCol = pAggInfo->aCol;
for(k=0; k<pAggInfo->nColumn; k++, pCol++){
if( pCol->pCExpr==pExpr ) return;
if( pCol->iTable==pExpr->iTable
&& pCol->iColumn==pExpr->iColumn
&& pExpr->op!=TK_IF_NULL_ROW
){
goto fix_up_expr;
}
}
k = addAggInfoColumn(pParse->db, pAggInfo);
if( k<0 ){
/* OOM on resize */
assert( pParse->db->mallocFailed );
return;
}
pCol = &pAggInfo->aCol[k];
assert( ExprUseYTab(pExpr) );
pCol->pTab = pExpr->y.pTab;
pCol->iTable = pExpr->iTable;
pCol->iColumn = pExpr->iColumn;
pCol->iSorterColumn = -1;
pCol->pCExpr = pExpr;
if( pAggInfo->pGroupBy && pExpr->op!=TK_IF_NULL_ROW ){
int j, n;
ExprList *pGB = pAggInfo->pGroupBy;
struct ExprList_item *pTerm = pGB->a;
n = pGB->nExpr;
for(j=0; j<n; j++, pTerm++){
Expr *pE = pTerm->pExpr;
if( pE->op==TK_COLUMN
&& pE->iTable==pExpr->iTable
&& pE->iColumn==pExpr->iColumn
){
pCol->iSorterColumn = j;
break;
}
}
}
if( pCol->iSorterColumn<0 ){
pCol->iSorterColumn = pAggInfo->nSortingColumn++;
}
fix_up_expr:
ExprSetVVAProperty(pExpr, EP_NoReduce);
assert( pExpr->pAggInfo==0 || pExpr->pAggInfo==pAggInfo );
pExpr->pAggInfo = pAggInfo;
if( pExpr->op==TK_COLUMN ){
pExpr->op = TK_AGG_COLUMN;
}
pExpr->iAgg = (i16)k;
}
/*
** This is the xExprCallback for a tree walker. It is used to
** implement sqlite3ExprAnalyzeAggregates(). See sqlite3ExprAnalyzeAggregates
** for additional information.
*/
static int analyzeAggregate(Walker *pWalker, Expr *pExpr){
int i;
NameContext *pNC = pWalker->u.pNC;
Parse *pParse = pNC->pParse;
SrcList *pSrcList = pNC->pSrcList;
AggInfo *pAggInfo = pNC->uNC.pAggInfo;
assert( pNC->ncFlags & NC_UAggInfo );
assert( pAggInfo->iFirstReg==0 );
switch( pExpr->op ){
default: {
IndexedExpr *pIEpr;
Expr tmp;
assert( pParse->iSelfTab==0 );
if( (pNC->ncFlags & NC_InAggFunc)==0 ) break;
if( pParse->pIdxEpr==0 ) break;
for(pIEpr=pParse->pIdxEpr; pIEpr; pIEpr=pIEpr->pIENext){
int iDataCur = pIEpr->iDataCur;
if( iDataCur<0 ) continue;
if( sqlite3ExprCompare(0, pExpr, pIEpr->pExpr, iDataCur)==0 ) break;
}
if( pIEpr==0 ) break;
if( NEVER(!ExprUseYTab(pExpr)) ) break;
for(i=0; i<pSrcList->nSrc; i++){
if( pSrcList->a[0].iCursor==pIEpr->iDataCur ) break;
}
if( i>=pSrcList->nSrc ) break;
if( NEVER(pExpr->pAggInfo!=0) ) break; /* Resolved by outer context */
if( pParse->nErr ){ return WRC_Abort; }
/* If we reach this point, it means that expression pExpr can be
** translated into a reference to an index column as described by
** pIEpr.
*/
memset(&tmp, 0, sizeof(tmp));
tmp.op = TK_AGG_COLUMN;
tmp.iTable = pIEpr->iIdxCur;
tmp.iColumn = pIEpr->iIdxCol;
findOrCreateAggInfoColumn(pParse, pAggInfo, &tmp);
if( pParse->nErr ){ return WRC_Abort; }
assert( pAggInfo->aCol!=0 );
assert( tmp.iAgg<pAggInfo->nColumn );
pAggInfo->aCol[tmp.iAgg].pCExpr = pExpr;
pExpr->pAggInfo = pAggInfo;
pExpr->iAgg = tmp.iAgg;
return WRC_Prune;
}
case TK_IF_NULL_ROW:
case TK_AGG_COLUMN:
case TK_COLUMN: {
testcase( pExpr->op==TK_AGG_COLUMN );
testcase( pExpr->op==TK_COLUMN );
testcase( pExpr->op==TK_IF_NULL_ROW );
/* Check to see if the column is in one of the tables in the FROM
** clause of the aggregate query */
if( ALWAYS(pSrcList!=0) ){
SrcItem *pItem = pSrcList->a;
for(i=0; i<pSrcList->nSrc; i++, pItem++){
assert( !ExprHasProperty(pExpr, EP_TokenOnly|EP_Reduced) );
if( pExpr->iTable==pItem->iCursor ){
findOrCreateAggInfoColumn(pParse, pAggInfo, pExpr);
break;
} /* endif pExpr->iTable==pItem->iCursor */
} /* end loop over pSrcList */
}
return WRC_Continue;
}
case TK_AGG_FUNCTION: {
if( (pNC->ncFlags & NC_InAggFunc)==0
&& pWalker->walkerDepth==pExpr->op2
&& pExpr->pAggInfo==0
){
/* Check to see if pExpr is a duplicate of another aggregate
** function that is already in the pAggInfo structure
*/
struct AggInfo_func *pItem = pAggInfo->aFunc;
for(i=0; i<pAggInfo->nFunc; i++, pItem++){
if( NEVER(pItem->pFExpr==pExpr) ) break;
if( sqlite3ExprCompare(0, pItem->pFExpr, pExpr, -1)==0 ){
break;
}
}
if( i>=pAggInfo->nFunc ){
/* pExpr is original. Make a new entry in pAggInfo->aFunc[]
*/
u8 enc = ENC(pParse->db);
i = addAggInfoFunc(pParse->db, pAggInfo);
if( i>=0 ){
int nArg;
assert( !ExprHasProperty(pExpr, EP_xIsSelect) );
pItem = &pAggInfo->aFunc[i];
pItem->pFExpr = pExpr;
assert( ExprUseUToken(pExpr) );
nArg = pExpr->x.pList ? pExpr->x.pList->nExpr : 0;
pItem->pFunc = sqlite3FindFunction(pParse->db,
pExpr->u.zToken, nArg, enc, 0);
assert( pItem->bOBUnique==0 );
if( pExpr->pLeft
&& (pItem->pFunc->funcFlags & SQLITE_FUNC_NEEDCOLL)==0
){
/* The NEEDCOLL test above causes any ORDER BY clause on
** aggregate min() or max() to be ignored. */
ExprList *pOBList;
assert( nArg>0 );
assert( pExpr->pLeft->op==TK_ORDER );
assert( ExprUseXList(pExpr->pLeft) );
pItem->iOBTab = pParse->nTab++;
pOBList = pExpr->pLeft->x.pList;
assert( pOBList->nExpr>0 );
assert( pItem->bOBUnique==0 );
if( pOBList->nExpr==1
&& nArg==1
&& sqlite3ExprCompare(0,pOBList->a[0].pExpr,
pExpr->x.pList->a[0].pExpr,0)==0
){
pItem->bOBPayload = 0;
pItem->bOBUnique = ExprHasProperty(pExpr, EP_Distinct);
}else{
pItem->bOBPayload = 1;
}
pItem->bUseSubtype =
(pItem->pFunc->funcFlags & SQLITE_SUBTYPE)!=0;
}else{
pItem->iOBTab = -1;
}
if( ExprHasProperty(pExpr, EP_Distinct) && !pItem->bOBUnique ){
pItem->iDistinct = pParse->nTab++;
}else{
pItem->iDistinct = -1;
}
}
}
/* Make pExpr point to the appropriate pAggInfo->aFunc[] entry
*/
assert( !ExprHasProperty(pExpr, EP_TokenOnly|EP_Reduced) );
ExprSetVVAProperty(pExpr, EP_NoReduce);
pExpr->iAgg = (i16)i;
pExpr->pAggInfo = pAggInfo;
return WRC_Prune;
}else{
return WRC_Continue;
}
}
}
return WRC_Continue;
}
/*
** Analyze the pExpr expression looking for aggregate functions and
** for variables that need to be added to AggInfo object that pNC->pAggInfo
** points to. Additional entries are made on the AggInfo object as
** necessary.
**
** This routine should only be called after the expression has been
** analyzed by sqlite3ResolveExprNames().
*/
void sqlite3ExprAnalyzeAggregates(NameContext *pNC, Expr *pExpr){
Walker w;
w.xExprCallback = analyzeAggregate;
w.xSelectCallback = sqlite3WalkerDepthIncrease;
w.xSelectCallback2 = sqlite3WalkerDepthDecrease;
w.walkerDepth = 0;
w.u.pNC = pNC;
w.pParse = 0;
assert( pNC->pSrcList!=0 );
sqlite3WalkExpr(&w, pExpr);
}
/*
** Call sqlite3ExprAnalyzeAggregates() for every expression in an
** expression list. Return the number of errors.
**
** If an error is found, the analysis is cut short.
*/
void sqlite3ExprAnalyzeAggList(NameContext *pNC, ExprList *pList){
struct ExprList_item *pItem;
int i;
if( pList ){
for(pItem=pList->a, i=0; i<pList->nExpr; i++, pItem++){
sqlite3ExprAnalyzeAggregates(pNC, pItem->pExpr);
}
}
}
/*
** Allocate a single new register for use to hold some intermediate result.
*/
int sqlite3GetTempReg(Parse *pParse){
if( pParse->nTempReg==0 ){
return ++pParse->nMem;
}
return pParse->aTempReg[--pParse->nTempReg];
}
/*
** Deallocate a register, making available for reuse for some other
** purpose.
*/
void sqlite3ReleaseTempReg(Parse *pParse, int iReg){
if( iReg ){
sqlite3VdbeReleaseRegisters(pParse, iReg, 1, 0, 0);
if( pParse->nTempReg<ArraySize(pParse->aTempReg) ){
pParse->aTempReg[pParse->nTempReg++] = iReg;
}
}
}
/*
** Allocate or deallocate a block of nReg consecutive registers.
*/
int sqlite3GetTempRange(Parse *pParse, int nReg){
int i, n;
if( nReg==1 ) return sqlite3GetTempReg(pParse);
i = pParse->iRangeReg;
n = pParse->nRangeReg;
if( nReg<=n ){
pParse->iRangeReg += nReg;
pParse->nRangeReg -= nReg;
}else{
i = pParse->nMem+1;
pParse->nMem += nReg;
}
return i;
}
void sqlite3ReleaseTempRange(Parse *pParse, int iReg, int nReg){
if( nReg==1 ){
sqlite3ReleaseTempReg(pParse, iReg);
return;
}
sqlite3VdbeReleaseRegisters(pParse, iReg, nReg, 0, 0);
if( nReg>pParse->nRangeReg ){
pParse->nRangeReg = nReg;
pParse->iRangeReg = iReg;
}
}
/*
** Mark all temporary registers as being unavailable for reuse.
**
** Always invoke this procedure after coding a subroutine or co-routine
** that might be invoked from other parts of the code, to ensure that
** the sub/co-routine does not use registers in common with the code that
** invokes the sub/co-routine.
*/
void sqlite3ClearTempRegCache(Parse *pParse){
pParse->nTempReg = 0;
pParse->nRangeReg = 0;
}
/*
** Make sure sufficient registers have been allocated so that
** iReg is a valid register number.
*/
void sqlite3TouchRegister(Parse *pParse, int iReg){
if( pParse->nMem<iReg ) pParse->nMem = iReg;
}
#if defined(SQLITE_ENABLE_STAT4) || defined(SQLITE_DEBUG)
/*
** Return the latest reusable register in the set of all registers.
** The value returned is no less than iMin. If any register iMin or
** greater is in permanent use, then return one more than that last
** permanent register.
*/
int sqlite3FirstAvailableRegister(Parse *pParse, int iMin){
const ExprList *pList = pParse->pConstExpr;
if( pList ){
int i;
for(i=0; i<pList->nExpr; i++){
if( pList->a[i].u.iConstExprReg>=iMin ){
iMin = pList->a[i].u.iConstExprReg + 1;
}
}
}
pParse->nTempReg = 0;
pParse->nRangeReg = 0;
return iMin;
}
#endif /* SQLITE_ENABLE_STAT4 || SQLITE_DEBUG */
/*
** Validate that no temporary register falls within the range of
** iFirst..iLast, inclusive. This routine is only call from within assert()
** statements.
*/
#ifdef SQLITE_DEBUG
int sqlite3NoTempsInRange(Parse *pParse, int iFirst, int iLast){
int i;
if( pParse->nRangeReg>0
&& pParse->iRangeReg+pParse->nRangeReg > iFirst
&& pParse->iRangeReg <= iLast
){
return 0;
}
for(i=0; i<pParse->nTempReg; i++){
if( pParse->aTempReg[i]>=iFirst && pParse->aTempReg[i]<=iLast ){
return 0;
}
}
if( pParse->pConstExpr ){
ExprList *pList = pParse->pConstExpr;
for(i=0; i<pList->nExpr; i++){
int iReg = pList->a[i].u.iConstExprReg;
if( iReg==0 ) continue;
if( iReg>=iFirst && iReg<=iLast ) return 0;
}
}
return 1;
}
#endif /* SQLITE_DEBUG */
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