/*
** 2001 September 15
**
** The author disclaims copyright to this source code. In place of
** a legal notice, here is a blessing:
**
** May you do good and not evil.
** May you find forgiveness for yourself and forgive others.
** May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains routines used for analyzing expressions and
** for generating VDBE code that evaluates expressions in SQLite.
*/
#include "sqliteInt.h"
/* Forward declarations */
static void exprCodeBetween(Parse*,Expr*,int,void(*)(Parse*,Expr*,int,int),int);
static int exprCodeVector(Parse *pParse, Expr *p, int *piToFree);
/*
** Return the affinity character for a single column of a table.
*/
char sqlite3TableColumnAffinity(Table *pTab, int iCol){
assert( iColnCol );
return iCol>=0 ? pTab->aCol[iCol].affinity : SQLITE_AFF_INTEGER;
}
/*
** Return the 'affinity' of the expression pExpr if any.
**
** If pExpr is a column, a reference to a column via an 'AS' alias,
** or a sub-select with a column as the return value, then the
** affinity of that column is returned. Otherwise, 0x00 is returned,
** indicating no affinity for the expression.
**
** i.e. the WHERE clause expressions in the following statements all
** have an affinity:
**
** CREATE TABLE t1(a);
** SELECT * FROM t1 WHERE a;
** SELECT a AS b FROM t1 WHERE b;
** SELECT * FROM t1 WHERE (select a from t1);
*/
char sqlite3ExprAffinity(Expr *pExpr){
int op;
pExpr = sqlite3ExprSkipCollate(pExpr);
if( pExpr->flags & EP_Generic ) return 0;
op = pExpr->op;
if( op==TK_SELECT ){
assert( pExpr->flags&EP_xIsSelect );
return sqlite3ExprAffinity(pExpr->x.pSelect->pEList->a[0].pExpr);
}
if( op==TK_REGISTER ) op = pExpr->op2;
#ifndef SQLITE_OMIT_CAST
if( op==TK_CAST ){
assert( !ExprHasProperty(pExpr, EP_IntValue) );
return sqlite3AffinityType(pExpr->u.zToken, 0);
}
#endif
if( (op==TK_AGG_COLUMN || op==TK_COLUMN) && pExpr->pTab ){
return sqlite3TableColumnAffinity(pExpr->pTab, pExpr->iColumn);
}
if( op==TK_SELECT_COLUMN ){
assert( pExpr->pLeft->flags&EP_xIsSelect );
return sqlite3ExprAffinity(
pExpr->pLeft->x.pSelect->pEList->a[pExpr->iColumn].pExpr
);
}
return pExpr->affinity;
}
/*
** Set the collating sequence for expression pExpr to be the collating
** sequence named by pToken. Return a pointer to a new Expr node that
** implements the COLLATE operator.
**
** If a memory allocation error occurs, that fact is recorded in pParse->db
** and the pExpr parameter is returned unchanged.
*/
Expr *sqlite3ExprAddCollateToken(
Parse *pParse, /* Parsing context */
Expr *pExpr, /* Add the "COLLATE" clause to this expression */
const Token *pCollName, /* Name of collating sequence */
int dequote /* True to dequote pCollName */
){
if( pCollName->n>0 ){
Expr *pNew = sqlite3ExprAlloc(pParse->db, TK_COLLATE, pCollName, dequote);
if( pNew ){
pNew->pLeft = pExpr;
pNew->flags |= EP_Collate|EP_Skip;
pExpr = pNew;
}
}
return pExpr;
}
Expr *sqlite3ExprAddCollateString(Parse *pParse, Expr *pExpr, const char *zC){
Token s;
assert( zC!=0 );
sqlite3TokenInit(&s, (char*)zC);
return sqlite3ExprAddCollateToken(pParse, pExpr, &s, 0);
}
/*
** Skip over any TK_COLLATE operators and any unlikely()
** or likelihood() function at the root of an expression.
*/
Expr *sqlite3ExprSkipCollate(Expr *pExpr){
while( pExpr && ExprHasProperty(pExpr, EP_Skip) ){
if( ExprHasProperty(pExpr, EP_Unlikely) ){
assert( !ExprHasProperty(pExpr, EP_xIsSelect) );
assert( pExpr->x.pList->nExpr>0 );
assert( pExpr->op==TK_FUNCTION );
pExpr = pExpr->x.pList->a[0].pExpr;
}else{
assert( pExpr->op==TK_COLLATE );
pExpr = pExpr->pLeft;
}
}
return pExpr;
}
/*
** Return the collation sequence for the expression pExpr. If
** there is no defined collating sequence, return NULL.
**
** The collating sequence might be determined by a COLLATE operator
** or by the presence of a column with a defined collating sequence.
** COLLATE operators take first precedence. Left operands take
** precedence over right operands.
*/
CollSeq *sqlite3ExprCollSeq(Parse *pParse, Expr *pExpr){
sqlite3 *db = pParse->db;
CollSeq *pColl = 0;
Expr *p = pExpr;
while( p ){
int op = p->op;
if( p->flags & EP_Generic ) break;
if( op==TK_CAST || op==TK_UPLUS ){
p = p->pLeft;
continue;
}
if( op==TK_COLLATE || (op==TK_REGISTER && p->op2==TK_COLLATE) ){
pColl = sqlite3GetCollSeq(pParse, ENC(db), 0, p->u.zToken);
break;
}
if( (op==TK_AGG_COLUMN || op==TK_COLUMN
|| op==TK_REGISTER || op==TK_TRIGGER)
&& p->pTab!=0
){
/* op==TK_REGISTER && p->pTab!=0 happens when pExpr was originally
** a TK_COLUMN but was previously evaluated and cached in a register */
int j = p->iColumn;
if( j>=0 ){
const char *zColl = p->pTab->aCol[j].zColl;
pColl = sqlite3FindCollSeq(db, ENC(db), zColl, 0);
}
break;
}
if( p->flags & EP_Collate ){
if( p->pLeft && (p->pLeft->flags & EP_Collate)!=0 ){
p = p->pLeft;
}else{
Expr *pNext = p->pRight;
/* The Expr.x union is never used at the same time as Expr.pRight */
assert( p->x.pList==0 || p->pRight==0 );
/* p->flags holds EP_Collate and p->pLeft->flags does not. And
** p->x.pSelect cannot. So if p->x.pLeft exists, it must hold at
** least one EP_Collate. Thus the following two ALWAYS. */
if( p->x.pList!=0 && ALWAYS(!ExprHasProperty(p, EP_xIsSelect)) ){
int i;
for(i=0; ALWAYS(ix.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;
}
/*
** pExpr is an operand of a comparison operator. aff2 is the
** type affinity of the other operand. This routine returns the
** type affinity that should be used for the comparison operator.
*/
char sqlite3CompareAffinity(Expr *pExpr, char aff2){
char aff1 = sqlite3ExprAffinity(pExpr);
if( aff1 && aff2 ){
/* 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 if( !aff1 && !aff2 ){
/* Neither side of the comparison is a column. Compare the
** results directly.
*/
return SQLITE_AFF_BLOB;
}else{
/* One side is a column, the other is not. Use the columns affinity. */
assert( aff1==0 || aff2==0 );
return (aff1 + aff2);
}
}
/*
** pExpr is a comparison operator. Return the type affinity that should
** be applied to both operands prior to doing the comparison.
*/
static char comparisonAffinity(Expr *pExpr){
char aff;
assert( pExpr->op==TK_EQ || pExpr->op==TK_IN || pExpr->op==TK_LT ||
pExpr->op==TK_GT || pExpr->op==TK_GE || pExpr->op==TK_LE ||
pExpr->op==TK_NE || pExpr->op==TK_IS || pExpr->op==TK_ISNOT );
assert( pExpr->pLeft );
aff = sqlite3ExprAffinity(pExpr->pLeft);
if( pExpr->pRight ){
aff = sqlite3CompareAffinity(pExpr->pRight, aff);
}else if( ExprHasProperty(pExpr, EP_xIsSelect) ){
aff = sqlite3CompareAffinity(pExpr->x.pSelect->pEList->a[0].pExpr, aff);
}else if( aff==0 ){
aff = SQLITE_AFF_BLOB;
}
return aff;
}
/*
** pExpr is a comparison expression, eg. '=', '=2 && (pExpr->flags & 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);
}
sqlite3VdbeAddOp4(v, pParse->iSelfTab ? OP_PureFunc0 : OP_Function0,
constMask, r1, target, (char*)pDef, P4_FUNCDEF);
sqlite3VdbeChangeP5(v, (u8)nFarg);
if( nFarg && constMask==0 ){
sqlite3ReleaseTempRange(pParse, r1, nFarg);
}
return target;
}
#ifndef SQLITE_OMIT_SUBQUERY
case TK_EXISTS:
case TK_SELECT: {
int nCol;
testcase( op==TK_EXISTS );
testcase( op==TK_SELECT );
if( op==TK_SELECT && (nCol = pExpr->x.pSelect->pEList->nExpr)!=1 ){
sqlite3SubselectError(pParse, nCol, 1);
}else{
return sqlite3CodeSubselect(pParse, pExpr, 0, 0);
}
break;
}
case TK_SELECT_COLUMN: {
int n;
if( pExpr->pLeft->iTable==0 ){
pExpr->pLeft->iTable = sqlite3CodeSubselect(pParse, pExpr->pLeft, 0, 0);
}
assert( pExpr->iTable==0 || pExpr->pLeft->op==TK_SELECT );
if( pExpr->iTable
&& pExpr->iTable!=(n = sqlite3ExprVectorSize(pExpr->pLeft))
){
sqlite3ErrorMsg(pParse, "%d columns assigned %d values",
pExpr->iTable, n);
}
return pExpr->pLeft->iTable + pExpr->iColumn;
}
case TK_IN: {
int destIfFalse = sqlite3VdbeMakeLabel(v);
int destIfNull = sqlite3VdbeMakeLabel(v);
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 xpLeft.
** 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_SPAN:
case TK_COLLATE:
case TK_UPLUS: {
return sqlite3ExprCodeTarget(pParse, pExpr->pLeft, target);
}
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 = pExpr->pTab;
int p1 = pExpr->iTable * (pTab->nCol+1) + 1 + pExpr->iColumn;
assert( pExpr->iTable==0 || pExpr->iTable==1 );
assert( pExpr->iColumn>=-1 && pExpr->iColumnnCol );
assert( pTab->iPKeyiColumn!=pTab->iPKey );
assert( p1>=0 && p1nCol*2+2) );
sqlite3VdbeAddOp2(v, OP_Param, p1, target);
VdbeComment((v, "%s.%s -> $%d",
(pExpr->iTable ? "new" : "old"),
(pExpr->iColumnpTab->aCol[pExpr->iColumn].zName),
target
));
#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( pExpr->iColumn>=0
&& pTab->aCol[pExpr->iColumn].affinity==SQLITE_AFF_REAL
){
sqlite3VdbeAddOp1(v, OP_RealAffinity, target);
}
#endif
break;
}
case TK_VECTOR: {
sqlite3ErrorMsg(pParse, "row value misused");
break;
}
case TK_IF_NULL_ROW: {
int addrINR;
addrINR = sqlite3VdbeAddOp1(v, OP_IfNullRow, pExpr->iTable);
sqlite3ExprCachePush(pParse);
inReg = sqlite3ExprCodeTarget(pParse, pExpr->pLeft, target);
sqlite3ExprCachePop(pParse);
sqlite3VdbeJumpHere(v, addrINR);
sqlite3VdbeChangeP3(v, addrINR, inReg);
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.
*/
default: assert( op==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) */
VVA_ONLY( int iCacheLevel = pParse->iCacheLevel; )
assert( !ExprHasProperty(pExpr, EP_xIsSelect) && pExpr->x.pList );
assert(pExpr->x.pList->nExpr > 0);
pEList = pExpr->x.pList;
aListelem = pEList->a;
nExpr = pEList->nExpr;
endLabel = sqlite3VdbeMakeLabel(v);
if( (pX = pExpr->pLeft)!=0 ){
tempX = *pX;
testcase( pX->op==TK_COLUMN );
exprToRegister(&tempX, exprCodeVector(pParse, &tempX, ®Free1));
testcase( regFree1==0 );
memset(&opCompare, 0, sizeof(opCompare));
opCompare.op = TK_EQ;
opCompare.pLeft = &tempX;
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; iop==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);
sqlite3ExprCachePop(pParse);
sqlite3VdbeResolveLabel(v, nextCase);
}
if( (nExpr&1)!=0 ){
sqlite3ExprCachePush(pParse);
sqlite3ExprCode(pParse, pEList->a[nExpr-1].pExpr, target);
sqlite3ExprCachePop(pParse);
}else{
sqlite3VdbeAddOp2(v, OP_Null, 0, target);
}
assert( pParse->db->mallocFailed || pParse->nErr>0
|| pParse->iCacheLevel==iCacheLevel );
sqlite3VdbeResolveLabel(v, endLabel);
break;
}
#ifndef SQLITE_OMIT_TRIGGER
case TK_RAISE: {
assert( pExpr->affinity==OE_Rollback
|| pExpr->affinity==OE_Abort
|| pExpr->affinity==OE_Fail
|| pExpr->affinity==OE_Ignore
);
if( !pParse->pTriggerTab ){
sqlite3ErrorMsg(pParse,
"RAISE() may only be used within a trigger-program");
return 0;
}
if( pExpr->affinity==OE_Abort ){
sqlite3MayAbort(pParse);
}
assert( !ExprHasProperty(pExpr, EP_IntValue) );
if( pExpr->affinity==OE_Ignore ){
sqlite3VdbeAddOp4(
v, OP_Halt, SQLITE_OK, OE_Ignore, 0, pExpr->u.zToken,0);
VdbeCoverage(v);
}else{
sqlite3HaltConstraint(pParse, SQLITE_CONSTRAINT_TRIGGER,
pExpr->affinity, pExpr->u.zToken, 0, 0);
}
break;
}
#endif
}
sqlite3ReleaseTempReg(pParse, regFree1);
sqlite3ReleaseTempReg(pParse, regFree2);
return inReg;
}
/*
** Factor out the code of the given expression to initialization time.
**
** If regDest>=0 then the result is always stored in that register and the
** result is not reusable. If regDestnExpr; i>0; pItem++, i--){
if( pItem->reusable && sqlite3ExprCompare(0,pItem->pExpr,pExpr,-1)==0 ){
return pItem->u.iConstExprReg;
}
}
}
pExpr = sqlite3ExprDup(pParse->db, pExpr, 0);
p = sqlite3ExprListAppend(pParse, p, pExpr);
if( p ){
struct ExprList_item *pItem = &p->a[p->nExpr-1];
pItem->reusable = regDestu.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 = sqlite3ExprSkipCollate(pExpr);
if( ConstFactorOk(pParse)
&& pExpr->op!=TK_REGISTER
&& sqlite3ExprIsConstantNotJoin(pExpr)
){
*pReg = 0;
r2 = sqlite3ExprCodeAtInit(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( target>0 && targetnMem );
if( pExpr && pExpr->op==TK_REGISTER ){
sqlite3VdbeAddOp2(pParse->pVdbe, OP_Copy, pExpr->iTable, target);
}else{
inReg = sqlite3ExprCodeTarget(pParse, pExpr, target);
assert( pParse->pVdbe!=0 || pParse->db->mallocFailed );
if( inReg!=target && pParse->pVdbe ){
sqlite3VdbeAddOp2(pParse->pVdbe, OP_SCopy, 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 && sqlite3ExprIsConstant(pExpr) ){
sqlite3ExprCodeAtInit(pParse, pExpr, target);
}else{
sqlite3ExprCode(pParse, pExpr, target);
}
}
/*
** Generate code that evaluates the given expression and puts the result
** in register target.
**
** Also make a copy of the expression results into another "cache" register
** and modify the expression so that the next time it is evaluated,
** the result is a copy of the cache register.
**
** This routine is used for expressions that are used multiple
** times. They are evaluated once and the results of the expression
** are reused.
*/
void sqlite3ExprCodeAndCache(Parse *pParse, Expr *pExpr, int target){
Vdbe *v = pParse->pVdbe;
int iMem;
assert( target>0 );
assert( pExpr->op!=TK_REGISTER );
sqlite3ExprCode(pParse, pExpr, target);
iMem = ++pParse->nMem;
sqlite3VdbeAddOp2(v, OP_Copy, target, iMem);
exprToRegister(pExpr, iMem);
}
/*
** 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 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.
*/
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; ipExpr;
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 && sqlite3ExprIsConstant(pExpr) ){
sqlite3ExprCodeAtInit(pParse, pExpr, target+i);
}else{
int inReg = sqlite3ExprCodeTarget(pParse, pExpr, target+i);
if( inReg!=target+i ){
VdbeOp *pOp;
if( copyOp==OP_Copy
&& (pOp=sqlite3VdbeGetOp(v, -1))->opcode==OP_Copy
&& pOp->p1+pOp->p3+1==inReg
&& pOp->p2+pOp->p3+1==target+i
){
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=y AND x=y term */
Expr compRight; /* The xpLeft;
exprAnd.op = TK_AND;
exprAnd.pLeft = &compLeft;
exprAnd.pRight = &compRight;
compLeft.op = TK_GE;
compLeft.pLeft = &exprX;
compLeft.pRight = pExpr->x.pList->a[0].pExpr;
compRight.op = TK_LE;
compRight.pLeft = &exprX;
compRight.pRight = pExpr->x.pList->a[1].pExpr;
exprToRegister(&exprX, exprCodeVector(pParse, &exprX, ®Free1));
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_FromJoin bit. Bummer. */
exprX.flags |= EP_FromJoin;
sqlite3ExprCodeTarget(pParse, &exprAnd, dest);
}
sqlite3ReleaseTempReg(pParse, regFree1);
/* 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 */
op = pExpr->op;
switch( op ){
case TK_AND: {
int d2 = sqlite3VdbeMakeLabel(v);
testcase( jumpIfNull==0 );
sqlite3ExprIfFalse(pParse, pExpr->pLeft, d2,jumpIfNull^SQLITE_JUMPIFNULL);
sqlite3ExprCachePush(pParse);
sqlite3ExprIfTrue(pParse, pExpr->pRight, dest, jumpIfNull);
sqlite3VdbeResolveLabel(v, d2);
sqlite3ExprCachePop(pParse);
break;
}
case TK_OR: {
testcase( jumpIfNull==0 );
sqlite3ExprIfTrue(pParse, pExpr->pLeft, dest, jumpIfNull);
sqlite3ExprCachePush(pParse);
sqlite3ExprIfTrue(pParse, pExpr->pRight, dest, jumpIfNull);
sqlite3ExprCachePop(pParse);
break;
}
case TK_NOT: {
testcase( jumpIfNull==0 );
sqlite3ExprIfFalse(pParse, pExpr->pLeft, dest, jumpIfNull);
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;
/* Fall thru */
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, ®Free1);
r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, ®Free2);
codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op,
r1, r2, dest, jumpIfNull);
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, ®Free1);
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(v);
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, ®Free1);
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;
/* 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: {
testcase( jumpIfNull==0 );
sqlite3ExprIfFalse(pParse, pExpr->pLeft, dest, jumpIfNull);
sqlite3ExprCachePush(pParse);
sqlite3ExprIfFalse(pParse, pExpr->pRight, dest, jumpIfNull);
sqlite3ExprCachePop(pParse);
break;
}
case TK_OR: {
int d2 = sqlite3VdbeMakeLabel(v);
testcase( jumpIfNull==0 );
sqlite3ExprIfTrue(pParse, pExpr->pLeft, d2, jumpIfNull^SQLITE_JUMPIFNULL);
sqlite3ExprCachePush(pParse);
sqlite3ExprIfFalse(pParse, pExpr->pRight, dest, jumpIfNull);
sqlite3VdbeResolveLabel(v, d2);
sqlite3ExprCachePop(pParse);
break;
}
case TK_NOT: {
testcase( jumpIfNull==0 );
sqlite3ExprIfTrue(pParse, pExpr->pLeft, dest, 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;
/* Fall thru */
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, ®Free1);
r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, ®Free2);
codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op,
r1, r2, dest, jumpIfNull);
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, ®Free1);
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(v);
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, ®Free1);
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(Parse *pParse, Expr *pVar, 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(Parse *pParse, Expr *pA, 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 ){
if( pA->op==TK_COLLATE && sqlite3ExprCompare(pParse, pA->pLeft,pB,iTab)op==TK_COLLATE && sqlite3ExprCompare(pParse, pA,pB->pLeft,iTab)op!=TK_COLUMN && pA->op!=TK_AGG_COLUMN && pA->u.zToken ){
if( pA->op==TK_FUNCTION ){
if( sqlite3StrICmp(pA->u.zToken,pB->u.zToken)!=0 ) return 2;
}else if( strcmp(pA->u.zToken,pB->u.zToken)!=0 ){
return pA->op==TK_COLLATE ? 1 : 2;
}
}
if( (pA->flags & EP_Distinct)!=(pB->flags & EP_Distinct) ) return 2;
if( ALWAYS((combinedFlags & EP_TokenOnly)==0) ){
if( combinedFlags & EP_xIsSelect ) return 2;
if( 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( ALWAYS((combinedFlags & EP_Reduced)==0) && pA->op!=TK_STRING ){
if( pA->iColumn!=pB->iColumn ) return 2;
if( pA->iTable!=pB->iTable
&& (pA->iTable!=iTab || NEVER(pB->iTable>=0)) ) return 2;
}
}
return 0;
}
/*
** Compare two ExprList objects. Return 0 if they are identical and
** non-zero if they differ in any way.
**
** 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(ExprList *pA, 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; inExpr; i++){
Expr *pExprA = pA->a[i].pExpr;
Expr *pExprB = pB->a[i].pExpr;
if( pA->a[i].sortOrder!=pB->a[i].sortOrder ) return 1;
if( sqlite3ExprCompare(0, pExprA, pExprB, iTab) ) return 1;
}
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 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 Reuslt: false
**
** When comparing TK_COLUMN nodes between pE1 and pE2, if pE2 has
** Expr.iTablepVdbe->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(Parse *pParse, Expr *pE1, 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 && pE1->op!=TK_ISNULL && pE1->op!=TK_IS ){
Expr *pX = sqlite3ExprSkipCollate(pE1->pLeft);
testcase( pX!=pE1->pLeft );
if( sqlite3ExprCompare(pParse, pX, pE2->pLeft, iTab)==0 ) return 1;
}
return 0;
}
/*
** 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
&& sqlite3ColumnOfIndex(pWalker->u.pIdxCover->pIdx, pExpr->iColumn)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;
}
/*
** An instance of the following structure is used by the tree walker
** to count references to table columns in the arguments of an
** aggregate function, in order to implement the
** sqlite3FunctionThisSrc() routine.
*/
struct SrcCount {
SrcList *pSrc; /* One particular FROM clause in a nested query */
int nThis; /* Number of references to columns in pSrcList */
int nOther; /* Number of references to columns in other FROM clauses */
};
/*
** Count the number of references to columns.
*/
static int exprSrcCount(Walker *pWalker, Expr *pExpr){
/* The NEVER() on the second term is because sqlite3FunctionUsesThisSrc()
** is always called before sqlite3ExprAnalyzeAggregates() and so the
** TK_COLUMNs have not yet been converted into TK_AGG_COLUMN. If
** sqlite3FunctionUsesThisSrc() is used differently in the future, the
** NEVER() will need to be removed. */
if( pExpr->op==TK_COLUMN || NEVER(pExpr->op==TK_AGG_COLUMN) ){
int i;
struct SrcCount *p = pWalker->u.pSrcCount;
SrcList *pSrc = p->pSrc;
int nSrc = pSrc ? pSrc->nSrc : 0;
for(i=0; iiTable==pSrc->a[i].iCursor ) break;
}
if( inThis++;
}else{
p->nOther++;
}
}
return WRC_Continue;
}
/*
** Determine if any of the arguments to the pExpr Function reference
** pSrcList. Return true if they do. Also return true if the function
** has no arguments or has only constant arguments. Return false if pExpr
** references columns but not columns of tables found in pSrcList.
*/
int sqlite3FunctionUsesThisSrc(Expr *pExpr, SrcList *pSrcList){
Walker w;
struct SrcCount cnt;
assert( pExpr->op==TK_AGG_FUNCTION );
w.xExprCallback = exprSrcCount;
w.xSelectCallback = 0;
w.u.pSrcCount = &cnt;
cnt.pSrc = pSrcList;
cnt.nThis = 0;
cnt.nOther = 0;
sqlite3WalkExprList(&w, pExpr->x.pList);
return cnt.nThis>0 || cnt.nOther==0;
}
/*
** 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;
}
/*
** 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->pAggInfo;
switch( pExpr->op ){
case TK_AGG_COLUMN:
case TK_COLUMN: {
testcase( pExpr->op==TK_AGG_COLUMN );
testcase( pExpr->op==TK_COLUMN );
/* Check to see if the column is in one of the tables in the FROM
** clause of the aggregate query */
if( ALWAYS(pSrcList!=0) ){
struct SrcList_item *pItem = pSrcList->a;
for(i=0; inSrc; i++, pItem++){
struct AggInfo_col *pCol;
assert( !ExprHasProperty(pExpr, EP_TokenOnly|EP_Reduced) );
if( pExpr->iTable==pItem->iCursor ){
/* If we reach this point, it means that pExpr refers to a table
** that is in the FROM clause of the aggregate query.
**
** Make an entry for the column in pAggInfo->aCol[] if there
** is not an entry there already.
*/
int k;
pCol = pAggInfo->aCol;
for(k=0; knColumn; k++, pCol++){
if( pCol->iTable==pExpr->iTable &&
pCol->iColumn==pExpr->iColumn ){
break;
}
}
if( (k>=pAggInfo->nColumn)
&& (k = addAggInfoColumn(pParse->db, pAggInfo))>=0
){
pCol = &pAggInfo->aCol[k];
pCol->pTab = pExpr->pTab;
pCol->iTable = pExpr->iTable;
pCol->iColumn = pExpr->iColumn;
pCol->iMem = ++pParse->nMem;
pCol->iSorterColumn = -1;
pCol->pExpr = pExpr;
if( pAggInfo->pGroupBy ){
int j, n;
ExprList *pGB = pAggInfo->pGroupBy;
struct ExprList_item *pTerm = pGB->a;
n = pGB->nExpr;
for(j=0; jpExpr;
if( pE->op==TK_COLUMN && pE->iTable==pExpr->iTable &&
pE->iColumn==pExpr->iColumn ){
pCol->iSorterColumn = j;
break;
}
}
}
if( pCol->iSorterColumniSorterColumn = pAggInfo->nSortingColumn++;
}
}
/* There is now an entry for pExpr in pAggInfo->aCol[] (either
** because it was there before or because we just created it).
** Convert the pExpr to be a TK_AGG_COLUMN referring to that
** pAggInfo->aCol[] entry.
*/
ExprSetVVAProperty(pExpr, EP_NoReduce);
pExpr->pAggInfo = pAggInfo;
pExpr->op = TK_AGG_COLUMN;
pExpr->iAgg = (i16)k;
break;
} /* endif pExpr->iTable==pItem->iCursor */
} /* end loop over pSrcList */
}
return WRC_Prune;
}
case TK_AGG_FUNCTION: {
if( (pNC->ncFlags & NC_InAggFunc)==0
&& pWalker->walkerDepth==pExpr->op2
){
/* 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; inFunc; i++, pItem++){
if( sqlite3ExprCompare(0, pItem->pExpr, 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 ){
assert( !ExprHasProperty(pExpr, EP_xIsSelect) );
pItem = &pAggInfo->aFunc[i];
pItem->pExpr = pExpr;
pItem->iMem = ++pParse->nMem;
assert( !ExprHasProperty(pExpr, EP_IntValue) );
pItem->pFunc = sqlite3FindFunction(pParse->db,
pExpr->u.zToken,
pExpr->x.pList ? pExpr->x.pList->nExpr : 0, enc, 0);
if( pExpr->flags & EP_Distinct ){
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;
}
static int analyzeAggregatesInSelect(Walker *pWalker, Select *pSelect){
UNUSED_PARAMETER(pSelect);
pWalker->walkerDepth++;
return WRC_Continue;
}
static void analyzeAggregatesInSelectEnd(Walker *pWalker, Select *pSelect){
UNUSED_PARAMETER(pSelect);
pWalker->walkerDepth--;
}
/*
** 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 = analyzeAggregatesInSelect;
w.xSelectCallback2 = analyzeAggregatesInSelectEnd;
w.walkerDepth = 0;
w.u.pNC = pNC;
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; inExpr; 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.
**
** If a register is currently being used by the column cache, then
** the deallocation is deferred until the column cache line that uses
** the register becomes stale.
*/
void sqlite3ReleaseTempReg(Parse *pParse, int iReg){
if( iReg && pParse->nTempRegaTempReg) ){
int i;
struct yColCache *p;
for(i=0, p=pParse->aColCache; inColCache; i++, p++){
if( p->iReg==iReg ){
p->tempReg = 1;
return;
}
}
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( nRegiRangeReg += 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;
}
sqlite3ExprCacheRemove(pParse, iReg, nReg);
if( nReg>pParse->nRangeReg ){
pParse->nRangeReg = nReg;
pParse->iRangeReg = iReg;
}
}
/*
** Mark all temporary registers as being unavailable for reuse.
*/
void sqlite3ClearTempRegCache(Parse *pParse){
pParse->nTempReg = 0;
pParse->nRangeReg = 0;
}
/*
** 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 aTempReg[i]>=iFirst && pParse->aTempReg[i]