/*

** 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

|| (op==TK_FUNCTION && pExpr->affExpr==SQLITE_AFF_DEFER)

){

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

|| (op==TK_FUNCTION && p->affExpr==SQLITE_AFF_DEFER)

){

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, (u16)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 = pToken ? pToken->n+1 : 0;

assert( db!=0 );

pNew = sqlite3DbMallocRawNN(db, sizeof(Expr)+nExtra);

if( pNew ){

memset(pNew, 0, sizeof(Expr));

pNew->op = (u8)op;

pNew->iAgg = -1;

if( nExtra ){

assert( pToken!=0 );

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);

}

/*

** Allocate an expression for a 32-bit signed integer literal.

*/

Expr *sqlite3ExprInt32(sqlite3 *db, int iVal){

Expr *pNew = sqlite3DbMallocRawNN(db, sizeof(Expr));

if( pNew ){

memset(pNew, 0, sizeof(Expr));

pNew->op = TK_INTEGER;

pNew->iAgg = -1;

pNew->flags = EP_IntValue|EP_Leaf|(iVal?EP_IsTrue:EP_IsFalse);

pNew->u.iValue = iVal;

#if SQLITE_MAX_EXPR_DEPTH>0

pNew->nHeight = 1;

#endif

}

return pNew;

}

/*

** 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.