Skip to content

HTTPS clone URL

Subversion checkout URL

You can clone with
or
.
Download ZIP
Fetching contributors…

Cannot retrieve contributors at this time

4117 lines (3923 sloc) 139.899 kB
/*
** 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"
/*
** 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 expresssions 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->op;
if( op==TK_SELECT ){
assert( pExpr->flags&EP_xIsSelect );
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);
}
#endif
if( (op==TK_AGG_COLUMN || op==TK_COLUMN || op==TK_REGISTER)
&& pExpr->pTab!=0
){
/* op==TK_REGISTER && pExpr->pTab!=0 happens when pExpr was originally
** a TK_COLUMN but was previously evaluated and cached in a register */
int j = pExpr->iColumn;
if( j<0 ) return SQLITE_AFF_INTEGER;
assert( pExpr->pTab && j<pExpr->pTab->nCol );
return pExpr->pTab->aCol[j].affinity;
}
return pExpr->affinity;
}
/*
** Set the explicit collating sequence for an expression to the
** collating sequence supplied in the second argument.
*/
Expr *sqlite3ExprSetColl(Expr *pExpr, CollSeq *pColl){
if( pExpr && pColl ){
pExpr->pColl = pColl;
pExpr->flags |= EP_ExpCollate;
}
return pExpr;
}
/*
** Set the collating sequence for expression pExpr to be the collating
** sequence named by pToken. Return a pointer to the revised expression.
** The collating sequence is marked as "explicit" using the EP_ExpCollate
** flag. An explicit collating sequence will override implicit
** collating sequences.
*/
Expr *sqlite3ExprSetCollByToken(Parse *pParse, Expr *pExpr, Token *pCollName){
char *zColl = 0; /* Dequoted name of collation sequence */
CollSeq *pColl;
sqlite3 *db = pParse->db;
zColl = sqlite3NameFromToken(db, pCollName);
pColl = sqlite3LocateCollSeq(pParse, zColl);
sqlite3ExprSetColl(pExpr, pColl);
sqlite3DbFree(db, zColl);
return pExpr;
}
/*
** Return the default collation sequence for the expression pExpr. If
** there is no default collation type, return 0.
*/
CollSeq *sqlite3ExprCollSeq(Parse *pParse, Expr *pExpr){
CollSeq *pColl = 0;
Expr *p = pExpr;
while( p ){
int op;
pColl = p->pColl;
if( pColl ) break;
op = p->op;
if( p->pTab!=0 && (
op==TK_AGG_COLUMN || op==TK_COLUMN || op==TK_REGISTER || op==TK_TRIGGER
)){
/* op==TK_REGISTER && p->pTab!=0 happens when pExpr was originally
** a TK_COLUMN but was previously evaluated and cached in a register */
const char *zColl;
int j = p->iColumn;
if( j>=0 ){
sqlite3 *db = pParse->db;
zColl = p->pTab->aCol[j].zColl;
pColl = sqlite3FindCollSeq(db, ENC(db), zColl, 0);
pExpr->pColl = pColl;
}
break;
}
if( op!=TK_CAST && op!=TK_UPLUS ){
break;
}
p = p->pLeft;
}
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_NONE;
}
}else if( !aff1 && !aff2 ){
/* Neither side of the comparison is a column. Compare the
** results directly.
*/
return SQLITE_AFF_NONE;
}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 ){
aff = SQLITE_AFF_NONE;
}
return aff;
}
/*
** pExpr is a comparison expression, eg. '=', '<', IN(...) etc.
** idx_affinity is the affinity of an indexed column. Return true
** if the index with affinity idx_affinity may be used to implement
** the comparison in pExpr.
*/
int sqlite3IndexAffinityOk(Expr *pExpr, char idx_affinity){
char aff = comparisonAffinity(pExpr);
switch( aff ){
case SQLITE_AFF_NONE:
return 1;
case SQLITE_AFF_TEXT:
return idx_affinity==SQLITE_AFF_TEXT;
default:
return sqlite3IsNumericAffinity(idx_affinity);
}
}
/*
** Return the P5 value that should be used for a binary comparison
** opcode (OP_Eq, OP_Ge etc.) used to compare pExpr1 and pExpr2.
*/
static u8 binaryCompareP5(Expr *pExpr1, Expr *pExpr2, int jumpIfNull){
u8 aff = (char)sqlite3ExprAffinity(pExpr2);
aff = (u8)sqlite3CompareAffinity(pExpr1, aff) | (u8)jumpIfNull;
return aff;
}
/*
** Return a pointer to the collation sequence that should be used by
** a binary comparison operator comparing pLeft and pRight.
**
** If the left hand expression has a collating sequence type, then it is
** used. Otherwise the collation sequence for the right hand expression
** is used, or the default (BINARY) if neither expression has a collating
** type.
**
** Argument pRight (but not pLeft) may be a null pointer. In this case,
** it is not considered.
*/
CollSeq *sqlite3BinaryCompareCollSeq(
Parse *pParse,
Expr *pLeft,
Expr *pRight
){
CollSeq *pColl;
assert( pLeft );
if( pLeft->flags & EP_ExpCollate ){
assert( pLeft->pColl );
pColl = pLeft->pColl;
}else if( pRight && pRight->flags & EP_ExpCollate ){
assert( pRight->pColl );
pColl = pRight->pColl;
}else{
pColl = sqlite3ExprCollSeq(pParse, pLeft);
if( !pColl ){
pColl = sqlite3ExprCollSeq(pParse, pRight);
}
}
return pColl;
}
/*
** Generate code for a comparison operator.
*/
static int codeCompare(
Parse *pParse, /* The parsing (and code generating) context */
Expr *pLeft, /* The left operand */
Expr *pRight, /* The right operand */
int opcode, /* The comparison opcode */
int in1, int in2, /* Register holding operands */
int dest, /* Jump here if true. */
int jumpIfNull /* If true, jump if either operand is NULL */
){
int p5;
int addr;
CollSeq *p4;
p4 = sqlite3BinaryCompareCollSeq(pParse, pLeft, pRight);
p5 = binaryCompareP5(pLeft, pRight, jumpIfNull);
addr = sqlite3VdbeAddOp4(pParse->pVdbe, opcode, in2, dest, in1,
(void*)p4, P4_COLLSEQ);
sqlite3VdbeChangeP5(pParse->pVdbe, (u8)p5);
return addr;
}
#if SQLITE_MAX_EXPR_DEPTH>0
/*
** Check that argument nHeight is less than or equal to the maximum
** expression depth allowed. If it is not, leave an error message in
** pParse.
*/
int sqlite3ExprCheckHeight(Parse *pParse, int nHeight){
int rc = SQLITE_OK;
int mxHeight = pParse->db->aLimit[SQLITE_LIMIT_EXPR_DEPTH];
if( nHeight>mxHeight ){
sqlite3ErrorMsg(pParse,
"Expression tree is too large (maximum depth %d)", mxHeight
);
rc = SQLITE_ERROR;
}
return rc;
}
/* The following three functions, heightOfExpr(), heightOfExprList()
** and heightOfSelect(), are used to determine the maximum height
** of any expression tree referenced by the structure passed as the
** first argument.
**
** If this maximum height is greater than the current value pointed
** to by pnHeight, the second parameter, then set *pnHeight to that
** value.
*/
static void heightOfExpr(Expr *p, int *pnHeight){
if( p ){
if( p->nHeight>*pnHeight ){
*pnHeight = p->nHeight;
}
}
}
static void heightOfExprList(ExprList *p, int *pnHeight){
if( p ){
int i;
for(i=0; i<p->nExpr; i++){
heightOfExpr(p->a[i].pExpr, pnHeight);
}
}
}
static void heightOfSelect(Select *p, int *pnHeight){
if( p ){
heightOfExpr(p->pWhere, pnHeight);
heightOfExpr(p->pHaving, pnHeight);
heightOfExpr(p->pLimit, pnHeight);
heightOfExpr(p->pOffset, pnHeight);
heightOfExprList(p->pEList, pnHeight);
heightOfExprList(p->pGroupBy, pnHeight);
heightOfExprList(p->pOrderBy, pnHeight);
heightOfSelect(p->pPrior, 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.
*/
static void exprSetHeight(Expr *p){
int nHeight = 0;
heightOfExpr(p->pLeft, &nHeight);
heightOfExpr(p->pRight, &nHeight);
if( ExprHasProperty(p, EP_xIsSelect) ){
heightOfSelect(p->x.pSelect, &nHeight);
}else{
heightOfExprList(p->x.pList, &nHeight);
}
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.
*/
void sqlite3ExprSetHeight(Parse *pParse, Expr *p){
exprSetHeight(p);
sqlite3ExprCheckHeight(pParse, p->nHeight);
}
/*
** Return the maximum height of any expression tree referenced
** by the select statement passed as an argument.
*/
int sqlite3SelectExprHeight(Select *p){
int nHeight = 0;
heightOfSelect(p, &nHeight);
return nHeight;
}
#else
#define exprSetHeight(y)
#endif /* SQLITE_MAX_EXPR_DEPTH>0 */
/*
** This routine is the core allocator for Expr nodes.
**
** Construct a new expression node and return a pointer to it. Memory
** for this node and for the pToken argument is a single allocation
** obtained from sqlite3DbMalloc(). The calling function
** is responsible for making sure the node eventually gets freed.
**
** If dequote is true, then the token (if it exists) is dequoted.
** If dequote is false, no dequoting is performance. The deQuote
** parameter is ignored if pToken is NULL or if the token does not
** appear to be quoted. If the quotes were of the form "..." (double-quotes)
** then the EP_DblQuoted flag is set on the expression node.
**
** Special case: If op==TK_INTEGER and pToken points to a string that
** can be translated into a 32-bit integer, then the token is not
** stored in u.zToken. Instead, the integer values is written
** into u.iValue and the EP_IntValue flag is set. No extra storage
** is allocated to hold the integer text and the dequote flag is ignored.
*/
Expr *sqlite3ExprAlloc(
sqlite3 *db, /* Handle for sqlite3DbMallocZero() (may be null) */
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;
if( pToken ){
if( op!=TK_INTEGER || pToken->z==0
|| sqlite3GetInt32(pToken->z, &iValue)==0 ){
nExtra = pToken->n+1;
assert( iValue>=0 );
}
}
pNew = sqlite3DbMallocZero(db, sizeof(Expr)+nExtra);
if( pNew ){
pNew->op = (u8)op;
pNew->iAgg = -1;
if( pToken ){
if( nExtra==0 ){
pNew->flags |= EP_IntValue;
pNew->u.iValue = iValue;
}else{
int c;
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 && nExtra>=3
&& ((c = pToken->z[0])=='\'' || c=='"' || c=='[' || c=='`') ){
sqlite3Dequote(pNew->u.zToken);
if( c=='"' ) pNew->flags |= EP_DblQuoted;
}
}
}
#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 = zToken ? sqlite3Strlen30(zToken) : 0;
return sqlite3ExprAlloc(db, op, &x, 0);
}
/*
** Attach subtrees pLeft and pRight to the Expr node pRoot.
**
** If pRoot==NULL that means that a memory allocation error has occurred.
** In that case, delete the subtrees pLeft and pRight.
*/
void sqlite3ExprAttachSubtrees(
sqlite3 *db,
Expr *pRoot,
Expr *pLeft,
Expr *pRight
){
if( pRoot==0 ){
assert( db->mallocFailed );
sqlite3ExprDelete(db, pLeft);
sqlite3ExprDelete(db, pRight);
}else{
if( pRight ){
pRoot->pRight = pRight;
if( pRight->flags & EP_ExpCollate ){
pRoot->flags |= EP_ExpCollate;
pRoot->pColl = pRight->pColl;
}
}
if( pLeft ){
pRoot->pLeft = pLeft;
if( pLeft->flags & EP_ExpCollate ){
pRoot->flags |= EP_ExpCollate;
pRoot->pColl = pLeft->pColl;
}
}
exprSetHeight(pRoot);
}
}
/*
** Allocate a 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 */
const Token *pToken /* Argument token */
){
Expr *p;
if( op==TK_AND && pLeft && pRight ){
/* Take advantage of short-circuit false optimization for AND */
p = sqlite3ExprAnd(pParse->db, pLeft, pRight);
}else{
p = sqlite3ExprAlloc(pParse->db, op, pToken, 1);
sqlite3ExprAttachSubtrees(pParse->db, p, pLeft, pRight);
}
if( p ) {
sqlite3ExprCheckHeight(pParse, p->nHeight);
}
return p;
}
/*
** Return 1 if an expression must be FALSE in all cases and 0 if the
** expression might be true. This is an optimization. If is OK to
** return 0 here even if the expression really is always false (a
** false negative). But it is a bug to return 1 if the expression
** might be true in some rare circumstances (a false positive.)
**
** Note that if the expression is part of conditional for a
** LEFT JOIN, then we cannot determine at compile-time whether or not
** is it true or false, so always return 0.
*/
static int exprAlwaysFalse(Expr *p){
int v = 0;
if( ExprHasProperty(p, EP_FromJoin) ) return 0;
if( !sqlite3ExprIsInteger(p, &v) ) return 0;
return v==0;
}
/*
** Join two expressions using an AND operator. If either expression is
** NULL, then just return the other expression.
**
** If one side or the other of the AND is known to be false, then instead
** of returning an AND expression, just return a constant expression with
** a value of false.
*/
Expr *sqlite3ExprAnd(sqlite3 *db, Expr *pLeft, Expr *pRight){
if( pLeft==0 ){
return pRight;
}else if( pRight==0 ){
return pLeft;
}else if( exprAlwaysFalse(pLeft) || exprAlwaysFalse(pRight) ){
sqlite3ExprDelete(db, pLeft);
sqlite3ExprDelete(db, pRight);
return sqlite3ExprAlloc(db, TK_INTEGER, &sqlite3IntTokens[0], 0);
}else{
Expr *pNew = sqlite3ExprAlloc(db, TK_AND, 0, 0);
sqlite3ExprAttachSubtrees(db, pNew, pLeft, pRight);
return pNew;
}
}
/*
** Construct a new expression node for a function with multiple
** arguments.
*/
Expr *sqlite3ExprFunction(Parse *pParse, ExprList *pList, Token *pToken){
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;
}
pNew->x.pList = pList;
assert( !ExprHasProperty(pNew, EP_xIsSelect) );
sqlite3ExprSetHeight(pParse, pNew);
return pNew;
}
/*
** Assign a variable number to an expression that encodes a wildcard
** in the original SQL statement.
**
** Wildcards consisting of a single "?" are assigned the next sequential
** variable number.
**
** Wildcards of the form "?nnn" are assigned the number "nnn". We make
** sure "nnn" is not too be to avoid a denial of service attack when
** the SQL statement comes from an external source.
**
** Wildcards of the form ":aaa", "@aaa", or "$aaa" are assigned the same number
** as the previous instance of the same wildcard. Or if this is the first
** instance of the wildcard, the next sequenial variable number is
** assigned.
*/
void sqlite3ExprAssignVarNumber(Parse *pParse, Expr *pExpr){
sqlite3 *db = pParse->db;
const char *z;
if( pExpr==0 ) return;
assert( !ExprHasAnyProperty(pExpr, EP_IntValue|EP_Reduced|EP_TokenOnly) );
z = pExpr->u.zToken;
assert( z!=0 );
assert( z[0]!=0 );
if( z[1]==0 ){
/* Wildcard of the form "?". Assign the next variable number */
assert( z[0]=='?' );
pExpr->iColumn = (ynVar)(++pParse->nVar);
}else{
ynVar x = 0;
u32 n = sqlite3Strlen30(z);
if( z[0]=='?' ){
/* Wildcard of the form "?nnn". Convert "nnn" to an integer and
** use it as the variable number */
i64 i;
int bOk = 0==sqlite3Atoi64(&z[1], &i, n-1, SQLITE_UTF8);
pExpr->iColumn = x = (ynVar)i;
testcase( i==0 );
testcase( i==1 );
testcase( i==db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER]-1 );
testcase( i==db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER] );
if( bOk==0 || i<1 || i>db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER] ){
sqlite3ErrorMsg(pParse, "variable number must be between ?1 and ?%d",
db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER]);
x = 0;
}
if( i>pParse->nVar ){
pParse->nVar = (int)i;
}
}else{
/* Wildcards like ":aaa", "$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
*/
ynVar i;
for(i=0; i<pParse->nzVar; i++){
if( pParse->azVar[i] && memcmp(pParse->azVar[i],z,n+1)==0 ){
pExpr->iColumn = x = (ynVar)i+1;
break;
}
}
if( x==0 ) x = pExpr->iColumn = (ynVar)(++pParse->nVar);
}
if( x>0 ){
if( x>pParse->nzVar ){
char **a;
a = sqlite3DbRealloc(db, pParse->azVar, x*sizeof(a[0]));
if( a==0 ) return; /* Error reported through db->mallocFailed */
pParse->azVar = a;
memset(&a[pParse->nzVar], 0, (x-pParse->nzVar)*sizeof(a[0]));
pParse->nzVar = x;
}
if( z[0]!='?' || pParse->azVar[x-1]==0 ){
sqlite3DbFree(db, pParse->azVar[x-1]);
pParse->azVar[x-1] = sqlite3DbStrNDup(db, z, n);
}
}
}
if( !pParse->nErr && pParse->nVar>db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER] ){
sqlite3ErrorMsg(pParse, "too many SQL variables");
}
}
/*
** Recursively delete an expression tree.
*/
void sqlite3ExprDelete(sqlite3 *db, Expr *p){
if( p==0 ) return;
/* Sanity check: Assert that the IntValue is non-negative if it exists */
assert( !ExprHasProperty(p, EP_IntValue) || p->u.iValue>=0 );
if( !ExprHasAnyProperty(p, EP_TokenOnly) ){
sqlite3ExprDelete(db, p->pLeft);
sqlite3ExprDelete(db, p->pRight);
if( !ExprHasProperty(p, EP_Reduced) && (p->flags2 & EP2_MallocedToken)!=0 ){
sqlite3DbFree(db, p->u.zToken);
}
if( ExprHasProperty(p, EP_xIsSelect) ){
sqlite3SelectDelete(db, p->x.pSelect);
}else{
sqlite3ExprListDelete(db, p->x.pList);
}
}
if( !ExprHasProperty(p, EP_Static) ){
sqlite3DbFree(db, p);
}
}
/*
** Return the number of bytes allocated for the expression structure
** passed as the first argument. This is always one of EXPR_FULLSIZE,
** EXPR_REDUCEDSIZE or EXPR_TOKENONLYSIZE.
*/
static int exprStructSize(Expr *p){
if( ExprHasProperty(p, EP_TokenOnly) ) return EXPR_TOKENONLYSIZE;
if( ExprHasProperty(p, EP_Reduced) ) return EXPR_REDUCEDSIZE;
return EXPR_FULLSIZE;
}
/*
** The dupedExpr*Size() routines each return the number of bytes required
** to store a copy of an expression or expression tree. They differ in
** how much of the tree is measured.
**
** dupedExprStructSize() Size of only the Expr structure
** dupedExprNodeSize() Size of Expr + space for token
** dupedExprSize() Expr + token + subtree components
**
***************************************************************************
**
** The dupedExprStructSize() function returns two values OR-ed together:
** (1) the space required for a copy of the Expr structure only and
** (2) the EP_xxx flags that indicate what the structure size should be.
** The return values is always one of:
**
** EXPR_FULLSIZE
** EXPR_REDUCEDSIZE | EP_Reduced
** EXPR_TOKENONLYSIZE | EP_TokenOnly
**
** The size of the structure can be found by masking the return value
** of this routine with 0xfff. The flags can be found by masking the
** return value with EP_Reduced|EP_TokenOnly.
**
** Note that with flags==EXPRDUP_REDUCE, this routines works on full-size
** (unreduced) Expr objects as they or originally constructed by the parser.
** During expression analysis, extra information is computed and moved into
** later parts of teh Expr object and that extra information might get chopped
** off if the expression is reduced. Note also that it does not work to
** make a EXPRDUP_REDUCE copy of a reduced expression. It is only legal
** to reduce a pristine expression tree from the parser. The implementation
** of dupedExprStructSize() contain multiple assert() statements that attempt
** to enforce this constraint.
*/
static int dupedExprStructSize(Expr *p, int flags){
int nSize;
assert( flags==EXPRDUP_REDUCE || flags==0 ); /* Only one flag value allowed */
if( 0==(flags&EXPRDUP_REDUCE) ){
nSize = EXPR_FULLSIZE;
}else{
assert( !ExprHasAnyProperty(p, EP_TokenOnly|EP_Reduced) );
assert( !ExprHasProperty(p, EP_FromJoin) );
assert( (p->flags2 & EP2_MallocedToken)==0 );
assert( (p->flags2 & EP2_Irreducible)==0 );
if( p->pLeft || p->pRight || p->pColl || p->x.pList ){
nSize = EXPR_REDUCEDSIZE | EP_Reduced;
}else{
nSize = EXPR_TOKENONLYSIZE | EP_TokenOnly;
}
}
return nSize;
}
/*
** This function returns the space in bytes required to store the copy
** of the Expr structure and a copy of the Expr.u.zToken string (if that
** string is defined.)
*/
static int dupedExprNodeSize(Expr *p, int flags){
int nByte = dupedExprStructSize(p, flags) & 0xfff;
if( !ExprHasProperty(p, EP_IntValue) && p->u.zToken ){
nByte += sqlite3Strlen30(p->u.zToken)+1;
}
return ROUND8(nByte);
}
/*
** Return the number of bytes required to create a duplicate of the
** expression passed as the first argument. The second argument is a
** mask containing EXPRDUP_XXX flags.
**
** The value returned includes space to create a copy of the Expr struct
** itself and the buffer referred to by Expr.u.zToken, if any.
**
** If the EXPRDUP_REDUCE flag is set, then the return value includes
** space to duplicate all Expr nodes in the tree formed by Expr.pLeft
** and Expr.pRight variables (but not for any structures pointed to or
** descended from the Expr.x.pList or Expr.x.pSelect variables).
*/
static int dupedExprSize(Expr *p, int flags){
int nByte = 0;
if( p ){
nByte = dupedExprNodeSize(p, flags);
if( flags&EXPRDUP_REDUCE ){
nByte += dupedExprSize(p->pLeft, flags) + dupedExprSize(p->pRight, flags);
}
}
return nByte;
}
/*
** This function is similar to sqlite3ExprDup(), except that if pzBuffer
** is not NULL then *pzBuffer is assumed to point to a buffer large enough
** to store the copy of expression p, the copies of p->u.zToken
** (if applicable), and the copies of the p->pLeft and p->pRight expressions,
** if any. Before returning, *pzBuffer is set to the first byte passed the
** portion of the buffer copied into by this function.
*/
static Expr *exprDup(sqlite3 *db, Expr *p, int flags, u8 **pzBuffer){
Expr *pNew = 0; /* Value to return */
if( p ){
const int isReduced = (flags&EXPRDUP_REDUCE);
u8 *zAlloc;
u32 staticFlag = 0;
assert( pzBuffer==0 || isReduced );
/* Figure out where to write the new Expr structure. */
if( pzBuffer ){
zAlloc = *pzBuffer;
staticFlag = EP_Static;
}else{
zAlloc = sqlite3DbMallocRaw(db, dupedExprSize(p, flags));
}
pNew = (Expr *)zAlloc;
if( pNew ){
/* Set nNewSize to the size allocated for the structure pointed to
** by pNew. This is either EXPR_FULLSIZE, EXPR_REDUCEDSIZE or
** EXPR_TOKENONLYSIZE. nToken is set to the number of bytes consumed
** by the copy of the p->u.zToken string (if any).
*/
const unsigned nStructSize = dupedExprStructSize(p, flags);
const int nNewSize = nStructSize & 0xfff;
int nToken;
if( !ExprHasProperty(p, EP_IntValue) && p->u.zToken ){
nToken = sqlite3Strlen30(p->u.zToken) + 1;
}else{
nToken = 0;
}
if( isReduced ){
assert( ExprHasProperty(p, EP_Reduced)==0 );
memcpy(zAlloc, p, nNewSize);
}else{
int nSize = exprStructSize(p);
memcpy(zAlloc, p, nSize);
memset(&zAlloc[nSize], 0, EXPR_FULLSIZE-nSize);
}
/* Set the EP_Reduced, EP_TokenOnly, and EP_Static flags appropriately. */
pNew->flags &= ~(EP_Reduced|EP_TokenOnly|EP_Static);
pNew->flags |= nStructSize & (EP_Reduced|EP_TokenOnly);
pNew->flags |= staticFlag;
/* Copy the p->u.zToken string, if any. */
if( nToken ){
char *zToken = pNew->u.zToken = (char*)&zAlloc[nNewSize];
memcpy(zToken, p->u.zToken, nToken);
}
if( 0==((p->flags|pNew->flags) & EP_TokenOnly) ){
/* Fill in the pNew->x.pSelect or pNew->x.pList member. */
if( ExprHasProperty(p, EP_xIsSelect) ){
pNew->x.pSelect = sqlite3SelectDup(db, p->x.pSelect, isReduced);
}else{
pNew->x.pList = sqlite3ExprListDup(db, p->x.pList, isReduced);
}
}
/* Fill in pNew->pLeft and pNew->pRight. */
if( ExprHasAnyProperty(pNew, EP_Reduced|EP_TokenOnly) ){
zAlloc += dupedExprNodeSize(p, flags);
if( ExprHasProperty(pNew, EP_Reduced) ){
pNew->pLeft = exprDup(db, p->pLeft, EXPRDUP_REDUCE, &zAlloc);
pNew->pRight = exprDup(db, p->pRight, EXPRDUP_REDUCE, &zAlloc);
}
if( pzBuffer ){
*pzBuffer = zAlloc;
}
}else{
pNew->flags2 = 0;
if( !ExprHasAnyProperty(p, EP_TokenOnly) ){
pNew->pLeft = sqlite3ExprDup(db, p->pLeft, 0);
pNew->pRight = sqlite3ExprDup(db, p->pRight, 0);
}
}
}
}
return pNew;
}
/*
** The following group of routines make deep copies of expressions,
** expression lists, ID lists, and select statements. The copies can
** be deleted (by being passed to their respective ...Delete() routines)
** without effecting the originals.
**
** The expression list, ID, and source lists return by sqlite3ExprListDup(),
** sqlite3IdListDup(), and sqlite3SrcListDup() can not be further expanded
** by subsequent calls to sqlite*ListAppend() routines.
**
** Any tables that the SrcList might point to are not duplicated.
**
** The flags parameter contains a combination of the EXPRDUP_XXX flags.
** If the EXPRDUP_REDUCE flag is set, then the structure returned is a
** truncated version of the usual Expr structure that will be stored as
** part of the in-memory representation of the database schema.
*/
Expr *sqlite3ExprDup(sqlite3 *db, Expr *p, int flags){
return exprDup(db, p, flags, 0);
}
ExprList *sqlite3ExprListDup(sqlite3 *db, ExprList *p, int flags){
ExprList *pNew;
struct ExprList_item *pItem, *pOldItem;
int i;
if( p==0 ) return 0;
pNew = sqlite3DbMallocRaw(db, sizeof(*pNew) );
if( pNew==0 ) return 0;
pNew->iECursor = 0;
pNew->nExpr = i = p->nExpr;
if( (flags & EXPRDUP_REDUCE)==0 ) for(i=1; i<p->nExpr; i+=i){}
pNew->a = pItem = sqlite3DbMallocRaw(db, i*sizeof(p->a[0]) );
if( pItem==0 ){
sqlite3DbFree(db, pNew);
return 0;
}
pOldItem = p->a;
for(i=0; i<p->nExpr; i++, pItem++, pOldItem++){
Expr *pOldExpr = pOldItem->pExpr;
pItem->pExpr = sqlite3ExprDup(db, pOldExpr, flags);
pItem->zName = sqlite3DbStrDup(db, pOldItem->zName);
pItem->zSpan = sqlite3DbStrDup(db, pOldItem->zSpan);
pItem->sortOrder = pOldItem->sortOrder;
pItem->done = 0;
pItem->iOrderByCol = pOldItem->iOrderByCol;
pItem->iAlias = pOldItem->iAlias;
}
return pNew;
}
/*
** If cursors, triggers, views and subqueries are all omitted from
** the build, then none of the following routines, except for
** sqlite3SelectDup(), can be called. sqlite3SelectDup() is sometimes
** called with a NULL argument.
*/
#if !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_TRIGGER) \
|| !defined(SQLITE_OMIT_SUBQUERY)
SrcList *sqlite3SrcListDup(sqlite3 *db, SrcList *p, int flags){
SrcList *pNew;
int i;
int nByte;
if( p==0 ) return 0;
nByte = sizeof(*p) + (p->nSrc>0 ? sizeof(p->a[0]) * (p->nSrc-1) : 0);
pNew = sqlite3DbMallocRaw(db, nByte );
if( pNew==0 ) return 0;
pNew->nSrc = pNew->nAlloc = p->nSrc;
for(i=0; i<p->nSrc; i++){
struct SrcList_item *pNewItem = &pNew->a[i];
struct SrcList_item *pOldItem = &p->a[i];
Table *pTab;
pNewItem->zDatabase = sqlite3DbStrDup(db, pOldItem->zDatabase);
pNewItem->zName = sqlite3DbStrDup(db, pOldItem->zName);
pNewItem->zAlias = sqlite3DbStrDup(db, pOldItem->zAlias);
pNewItem->jointype = pOldItem->jointype;
pNewItem->iCursor = pOldItem->iCursor;
pNewItem->addrFillSub = pOldItem->addrFillSub;
pNewItem->regReturn = pOldItem->regReturn;
pNewItem->isCorrelated = pOldItem->isCorrelated;
pNewItem->zIndex = sqlite3DbStrDup(db, pOldItem->zIndex);
pNewItem->notIndexed = pOldItem->notIndexed;
pNewItem->pIndex = pOldItem->pIndex;
pTab = pNewItem->pTab = pOldItem->pTab;
if( pTab ){
pTab->nRef++;
}
pNewItem->pSelect = sqlite3SelectDup(db, pOldItem->pSelect, flags);
pNewItem->pOn = sqlite3ExprDup(db, pOldItem->pOn, flags);
pNewItem->pUsing = sqlite3IdListDup(db, pOldItem->pUsing);
pNewItem->colUsed = pOldItem->colUsed;
}
return pNew;
}
IdList *sqlite3IdListDup(sqlite3 *db, IdList *p){
IdList *pNew;
int i;
if( p==0 ) return 0;
pNew = sqlite3DbMallocRaw(db, sizeof(*pNew) );
if( pNew==0 ) return 0;
pNew->nId = p->nId;
pNew->a = sqlite3DbMallocRaw(db, p->nId*sizeof(p->a[0]) );
if( pNew->a==0 ){
sqlite3DbFree(db, pNew);
return 0;
}
/* Note that because the size of the allocation for p->a[] is not
** necessarily a power of two, sqlite3IdListAppend() may not be called
** on the duplicate created by this function. */
for(i=0; i<p->nId; i++){
struct IdList_item *pNewItem = &pNew->a[i];
struct IdList_item *pOldItem = &p->a[i];
pNewItem->zName = sqlite3DbStrDup(db, pOldItem->zName);
pNewItem->idx = pOldItem->idx;
}
return pNew;
}
Select *sqlite3SelectDup(sqlite3 *db, Select *p, int flags){
Select *pNew, *pPrior;
if( p==0 ) return 0;
pNew = sqlite3DbMallocRaw(db, sizeof(*p) );
if( pNew==0 ) return 0;
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->pPrior = pPrior = sqlite3SelectDup(db, p->pPrior, flags);
if( pPrior ) pPrior->pNext = pNew;
pNew->pNext = 0;
pNew->pLimit = sqlite3ExprDup(db, p->pLimit, flags);
pNew->pOffset = sqlite3ExprDup(db, p->pOffset, flags);
pNew->iLimit = 0;
pNew->iOffset = 0;
pNew->selFlags = p->selFlags & ~SF_UsesEphemeral;
pNew->pRightmost = 0;
pNew->addrOpenEphm[0] = -1;
pNew->addrOpenEphm[1] = -1;
pNew->addrOpenEphm[2] = -1;
return pNew;
}
#else
Select *sqlite3SelectDup(sqlite3 *db, Select *p, int flags){
assert( p==0 );
return 0;
}
#endif
/*
** Add a new element to the end of an expression list. If pList is
** initially NULL, then create a new expression list.
**
** If a memory allocation error occurs, the entire list is freed and
** NULL is returned. If non-NULL is returned, then it is guaranteed
** that the new entry was successfully appended.
*/
ExprList *sqlite3ExprListAppend(
Parse *pParse, /* Parsing context */
ExprList *pList, /* List to which to append. Might be NULL */
Expr *pExpr /* Expression to be appended. Might be NULL */
){
sqlite3 *db = pParse->db;
if( pList==0 ){
pList = sqlite3DbMallocZero(db, sizeof(ExprList) );
if( pList==0 ){
goto no_mem;
}
pList->a = sqlite3DbMallocRaw(db, sizeof(pList->a[0]));
if( pList->a==0 ) goto no_mem;
}else if( (pList->nExpr & (pList->nExpr-1))==0 ){
struct ExprList_item *a;
assert( pList->nExpr>0 );
a = sqlite3DbRealloc(db, pList->a, pList->nExpr*2*sizeof(pList->a[0]));
if( a==0 ){
goto no_mem;
}
pList->a = a;
}
assert( pList->a!=0 );
if( 1 ){
struct ExprList_item *pItem = &pList->a[pList->nExpr++];
memset(pItem, 0, sizeof(*pItem));
pItem->pExpr = pExpr;
}
return pList;
no_mem:
/* Avoid leaking memory if malloc has failed. */
sqlite3ExprDelete(db, pExpr);
sqlite3ExprListDelete(db, pList);
return 0;
}
/*
** Set the ExprList.a[].zName element of the most recently added item
** on the expression list.
**
** pList might be NULL following an OOM error. But pName should never be
** NULL. If a memory allocation fails, the pParse->db->mallocFailed flag
** is set.
*/
void sqlite3ExprListSetName(
Parse *pParse, /* Parsing context */
ExprList *pList, /* List to which to add the span. */
Token *pName, /* Name to be added */
int dequote /* True to cause the name to be dequoted */
){
assert( pList!=0 || pParse->db->mallocFailed!=0 );
if( pList ){
struct ExprList_item *pItem;
assert( pList->nExpr>0 );
pItem = &pList->a[pList->nExpr-1];
assert( pItem->zName==0 );
pItem->zName = sqlite3DbStrNDup(pParse->db, pName->z, pName->n);
if( dequote && pItem->zName ) sqlite3Dequote(pItem->zName);
}
}
/*
** 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. */
ExprSpan *pSpan /* The span to be added */
){
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 );
assert( db->mallocFailed || pItem->pExpr==pSpan->pExpr );
sqlite3DbFree(db, pItem->zSpan);
pItem->zSpan = sqlite3DbStrNDup(db, (char*)pSpan->zStart,
(int)(pSpan->zEnd - pSpan->zStart));
}
}
/*
** 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.
*/
void sqlite3ExprListDelete(sqlite3 *db, ExprList *pList){
int i;
struct ExprList_item *pItem;
if( pList==0 ) return;
assert( pList->a!=0 || pList->nExpr==0 );
for(pItem=pList->a, i=0; i<pList->nExpr; i++, pItem++){
sqlite3ExprDelete(db, pItem->pExpr);
sqlite3DbFree(db, pItem->zName);
sqlite3DbFree(db, pItem->zSpan);
}
sqlite3DbFree(db, pList->a);
sqlite3DbFree(db, pList);
}
/*
** These routines are Walker callbacks. Walker.u.pi is a pointer
** to an integer. These routines are checking an expression to see
** if it is a constant. Set *Walker.u.pi to 0 if the expression is
** not constant.
**
** These callback routines are used to implement the following:
**
** sqlite3ExprIsConstant()
** sqlite3ExprIsConstantNotJoin()
** sqlite3ExprIsConstantOrFunction()
**
*/
static int exprNodeIsConstant(Walker *pWalker, Expr *pExpr){
/* If pWalker->u.i is 3 then any term of the expression that comes from
** the ON or USING clauses of a join disqualifies the expression
** from being considered constant. */
if( pWalker->u.i==3 && ExprHasAnyProperty(pExpr, EP_FromJoin) ){
pWalker->u.i = 0;
return WRC_Abort;
}
switch( pExpr->op ){
/* Consider functions to be constant if all their arguments are constant
** and pWalker->u.i==2 */
case TK_FUNCTION:
if( pWalker->u.i==2 ) return 0;
/* Fall through */
case TK_ID:
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 );
pWalker->u.i = 0;
return WRC_Abort;
default:
testcase( pExpr->op==TK_SELECT ); /* selectNodeIsConstant will disallow */
testcase( pExpr->op==TK_EXISTS ); /* selectNodeIsConstant will disallow */
return WRC_Continue;
}
}
static int selectNodeIsConstant(Walker *pWalker, Select *NotUsed){
UNUSED_PARAMETER(NotUsed);
pWalker->u.i = 0;
return WRC_Abort;
}
static int exprIsConst(Expr *p, int initFlag){
Walker w;
w.u.i = initFlag;
w.xExprCallback = exprNodeIsConstant;
w.xSelectCallback = selectNodeIsConstant;
sqlite3WalkExpr(&w, p);
return w.u.i;
}
/*
** Walk an expression tree. Return 1 if the expression is constant
** and 0 if it involves variables or function calls.
**
** For the purposes of this function, a double-quoted string (ex: "abc")
** is considered a variable but a single-quoted string (ex: 'abc') is
** a constant.
*/
int sqlite3ExprIsConstant(Expr *p){
return exprIsConst(p, 1);
}
/*
** Walk an expression tree. Return 1 if the expression is constant
** that does no originate from the ON or USING clauses of a join.
** Return 0 if it involves variables or function calls or terms from
** an ON or USING clause.
*/
int sqlite3ExprIsConstantNotJoin(Expr *p){
return exprIsConst(p, 3);
}
/*
** Walk an expression tree. Return 1 if the expression is constant
** or a function call with constant arguments. Return and 0 if there
** are any variables.
**
** For the purposes of this function, a double-quoted string (ex: "abc")
** is considered a variable but a single-quoted string (ex: 'abc') is
** a constant.
*/
int sqlite3ExprIsConstantOrFunction(Expr *p){
return exprIsConst(p, 2);
}
/*
** If the expression p codes a constant integer that is small enough
** to fit in a 32-bit integer, return 1 and put the value of the integer
** in *pValue. If the expression is not an integer or if it is too big
** to fit in a signed 32-bit integer, return 0 and leave *pValue unchanged.
*/
int sqlite3ExprIsInteger(Expr *p, int *pValue){
int rc = 0;
/* If an expression is an integer literal that fits in a signed 32-bit
** integer, then the EP_IntValue flag will have already been set */
assert( p->op!=TK_INTEGER || (p->flags & EP_IntValue)!=0
|| sqlite3GetInt32(p->u.zToken, &rc)==0 );
if( p->flags & EP_IntValue ){
*pValue = p->u.iValue;
return 1;
}
switch( p->op ){
case TK_UPLUS: {
rc = sqlite3ExprIsInteger(p->pLeft, pValue);
break;
}
case TK_UMINUS: {
int v;
if( sqlite3ExprIsInteger(p->pLeft, &v) ){
*pValue = -v;
rc = 1;
}
break;
}
default: break;
}
return rc;
}
/*
** Return FALSE if there is no chance that the expression can be NULL.
**
** If the expression might be NULL or if the expression is too complex
** to tell return TRUE.
**
** This routine is used as an optimization, to skip OP_IsNull opcodes
** when we know that a value cannot be NULL. Hence, a false positive
** (returning TRUE when in fact the expression can never be NULL) might
** be a small performance hit but is otherwise harmless. On the other
** hand, a false negative (returning FALSE when the result could be NULL)
** will likely result in an incorrect answer. So when in doubt, return
** TRUE.
*/
int sqlite3ExprCanBeNull(const Expr *p){
u8 op;
while( p->op==TK_UPLUS || p->op==TK_UMINUS ){ p = p->pLeft; }
op = p->op;
if( op==TK_REGISTER ) op = p->op2;
switch( op ){
case TK_INTEGER:
case TK_STRING:
case TK_FLOAT:
case TK_BLOB:
return 0;
default:
return 1;
}
}
/*
** Generate an OP_IsNull instruction that tests register iReg and jumps
** to location iDest if the value in iReg is NULL. The value in iReg
** was computed by pExpr. If we can look at pExpr at compile-time and
** determine that it can never generate a NULL, then the OP_IsNull operation
** can be omitted.
*/
void sqlite3ExprCodeIsNullJump(
Vdbe *v, /* The VDBE under construction */
const Expr *pExpr, /* Only generate OP_IsNull if this expr can be NULL */
int iReg, /* Test the value in this register for NULL */
int iDest /* Jump here if the value is null */
){
if( sqlite3ExprCanBeNull(pExpr) ){
sqlite3VdbeAddOp2(v, OP_IsNull, iReg, iDest);
}
}
/*
** 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;
if( aff==SQLITE_AFF_NONE ) return 1;
while( p->op==TK_UPLUS || p->op==TK_UMINUS ){ p = p->pLeft; }
op = p->op;
if( op==TK_REGISTER ) op = p->op2;
switch( op ){
case TK_INTEGER: {
return aff==SQLITE_AFF_INTEGER || aff==SQLITE_AFF_NUMERIC;
}
case TK_FLOAT: {
return aff==SQLITE_AFF_REAL || aff==SQLITE_AFF_NUMERIC;
}
case TK_STRING: {
return aff==SQLITE_AFF_TEXT;
}
case TK_BLOB: {
return 1;
}
case TK_COLUMN: {
assert( p->iTable>=0 ); /* p cannot be part of a CHECK constraint */
return p->iColumn<0
&& (aff==SQLITE_AFF_INTEGER || aff==SQLITE_AFF_NUMERIC);
}
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 true if we are able to the IN operator optimization on a
** query of the form
**
** x IN (SELECT ...)
**
** Where the SELECT... clause is as specified by the parameter to this
** routine.
**
** The Select object passed in has already been preprocessed and no
** errors have been found.
*/
#ifndef SQLITE_OMIT_SUBQUERY
static int isCandidateForInOpt(Select *p){
SrcList *pSrc;
ExprList *pEList;
Table *pTab;
if( p==0 ) return 0; /* right-hand side of IN is SELECT */
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 */
assert( p->pOffset==0 ); /* No LIMIT means no OFFSET */
if( p->pWhere ) return 0; /* Has no WHERE clause */
pSrc = p->pSrc;
assert( pSrc!=0 );
if( pSrc->nSrc!=1 ) return 0; /* Single term in FROM clause */
if( pSrc->a[0].pSelect ) return 0; /* FROM is not a subquery or view */
pTab = pSrc->a[0].pTab;
if( NEVER(pTab==0) ) return 0;
assert( pTab->pSelect==0 ); /* FROM clause is not a view */
if( IsVirtual(pTab) ) return 0; /* FROM clause not a virtual table */
pEList = p->pEList;
if( pEList->nExpr!=1 ) return 0; /* One column in the result set */
if( pEList->a[0].pExpr->op!=TK_COLUMN ) return 0; /* Result is a column */
return 1;
}
#endif /* SQLITE_OMIT_SUBQUERY */
/*
** Code an OP_Once instruction and allocate space for its flag. Return the
** address of the new instruction.
*/
int sqlite3CodeOnce(Parse *pParse){
Vdbe *v = sqlite3GetVdbe(pParse); /* Virtual machine being coded */
return sqlite3VdbeAddOp1(v, OP_Once, pParse->nOnce++);
}
/*
** This function is used by the implementation of the IN (...) operator.
** It's job is to find or create a b-tree structure that may be used
** either to test for membership of the (...) set or to iterate through
** its members, skipping duplicates.
**
** The index of the cursor opened on the b-tree (database table, database index
** or ephermal table) is stored in pX->iTable before this function returns.
** 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 - The cursor was opened on a database index.
** IN_INDEX_EPH - The cursor was opened on a specially created and
** populated epheremal table.
**
** An existing b-tree may only be used if the SELECT is of the simple
** form:
**
** SELECT <column> FROM <table>
**
** If the prNotFound parameter is 0, then the b-tree will be used to iterate
** through the set members, skipping any duplicates. In this case an
** epheremal table must be used unless the selected <column> is guaranteed
** to be unique - either because it is an INTEGER PRIMARY KEY or it
** has a UNIQUE constraint or UNIQUE index.
**
** If the prNotFound parameter is not 0, then the b-tree will be used
** for fast set membership tests. In this case an epheremal table must
** be used unless <column> is an INTEGER PRIMARY KEY or an index can
** be found with <column> as its left-most column.
**
** When the b-tree is being used for membership tests, the calling function
** needs to know whether or not the structure contains an SQL NULL
** value in order to correctly evaluate expressions like "X IN (Y, Z)".
** 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 *prNotFound. If there is no chance that the (...) contains a
** NULL value, then *prNotFound is left unchanged.
**
** If a register is allocated and its location stored in *prNotFound, then
** its initial value is NULL. If the (...) does not remain constant
** for the duration of the query (i.e. the SELECT within the (...)
** is a correlated subquery) then the value of the allocated register is
** reset to NULL each time the subquery is rerun. This allows the
** caller to use vdbe code equivalent to the following:
**
** if( register==NULL ){
** has_null = <test if data structure contains null>
** register = 1
** }
**
** in order to avoid running the <test if data structure contains null>
** test more often than is necessary.
*/
#ifndef SQLITE_OMIT_SUBQUERY
int sqlite3FindInIndex(Parse *pParse, Expr *pX, int *prNotFound){
Select *p; /* SELECT to the right of IN operator */
int eType = 0; /* Type of RHS table. IN_INDEX_* */
int iTab = pParse->nTab++; /* Cursor of the RHS table */
int mustBeUnique = (prNotFound==0); /* True if RHS must be unique */
Vdbe *v = sqlite3GetVdbe(pParse); /* Virtual machine being coded */
assert( pX->op==TK_IN );
/* 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.
*/
p = (ExprHasProperty(pX, EP_xIsSelect) ? pX->x.pSelect : 0);
if( ALWAYS(pParse->nErr==0) && isCandidateForInOpt(p) ){
sqlite3 *db = pParse->db; /* Database connection */
Table *pTab; /* Table <table>. */
Expr *pExpr; /* Expression <column> */
int iCol; /* Index of column <column> */
int iDb; /* Database idx for pTab */
assert( p ); /* Because of isCandidateForInOpt(p) */
assert( p->pEList!=0 ); /* Because of isCandidateForInOpt(p) */
assert( p->pEList->a[0].pExpr!=0 ); /* Because of isCandidateForInOpt(p) */
assert( p->pSrc!=0 ); /* Because of isCandidateForInOpt(p) */
pTab = p->pSrc->a[0].pTab;
pExpr = p->pEList->a[0].pExpr;
iCol = pExpr->iColumn;
/* Code an OP_VerifyCookie and OP_TableLock for <table>. */
iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
sqlite3CodeVerifySchema(pParse, iDb);
sqlite3TableLock(pParse, iDb, pTab->tnum, 0, pTab->zName);
/* This function is only called from two places. In both cases the vdbe
** has already been allocated. So assume sqlite3GetVdbe() is always
** successful here.
*/
assert(v);
if( iCol<0 ){
int iAddr;
iAddr = sqlite3CodeOnce(pParse);
sqlite3OpenTable(pParse, iTab, iDb, pTab, OP_OpenRead);
eType = IN_INDEX_ROWID;
sqlite3VdbeJumpHere(v, iAddr);
}else{
Index *pIdx; /* Iterator variable */
/* The collation sequence used by the comparison. If an index is to
** be used in place of a temp-table, it must be ordered according
** to this collation sequence. */
CollSeq *pReq = sqlite3BinaryCompareCollSeq(pParse, pX->pLeft, pExpr);
/* Check that the affinity that will be used to perform the
** comparison is the same as the affinity of the column. If
** it is not, it is not possible to use any index.
*/
char aff = comparisonAffinity(pX);
int affinity_ok = (pTab->aCol[iCol].affinity==aff||aff==SQLITE_AFF_NONE);
for(pIdx=pTab->pIndex; pIdx && eType==0 && affinity_ok; pIdx=pIdx->pNext){
if( (pIdx->aiColumn[0]==iCol)
&& sqlite3FindCollSeq(db, ENC(db), pIdx->azColl[0], 0)==pReq
&& (!mustBeUnique || (pIdx->nColumn==1 && pIdx->onError!=OE_None))
){
int iAddr;
char *pKey;
pKey = (char *)sqlite3IndexKeyinfo(pParse, pIdx);
iAddr = sqlite3CodeOnce(pParse);
sqlite3VdbeAddOp4(v, OP_OpenRead, iTab, pIdx->tnum, iDb,
pKey,P4_KEYINFO_HANDOFF);
VdbeComment((v, "%s", pIdx->zName));
eType = IN_INDEX_INDEX;
sqlite3VdbeJumpHere(v, iAddr);
if( prNotFound && !pTab->aCol[iCol].notNull ){
*prNotFound = ++pParse->nMem;
sqlite3VdbeAddOp2(v, OP_Null, 0, *prNotFound);
}
}
}
}
}
if( eType==0 ){
/* Could not found an existing table or index to use as the RHS b-tree.
** We will have to generate an ephemeral table to do the job.
*/
double savedNQueryLoop = pParse->nQueryLoop;
int rMayHaveNull = 0;
eType = IN_INDEX_EPH;
if( prNotFound ){
*prNotFound = rMayHaveNull = ++pParse->nMem;
sqlite3VdbeAddOp2(v, OP_Null, 0, *prNotFound);
}else{
testcase( pParse->nQueryLoop>(double)1 );
pParse->nQueryLoop = (double)1;
if( pX->pLeft->iColumn<0 && !ExprHasAnyProperty(pX, EP_xIsSelect) ){
eType = IN_INDEX_ROWID;
}
}
sqlite3CodeSubselect(pParse, pX, rMayHaveNull, eType==IN_INDEX_ROWID);
pParse->nQueryLoop = savedNQueryLoop;
}else{
pX->iTable = iTab;
}
return eType;
}
#endif
/*
** Generate code for scalar subqueries used as a subquery expression, EXISTS,
** or IN operators. Examples:
**
** (SELECT a FROM b) -- subquery
** EXISTS (SELECT a FROM b) -- EXISTS subquery
** 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 describes the expression that contains the IN
** operator or subquery.
**
** If parameter isRowid is non-zero, then expression pExpr is guaranteed
** to be of the form "<rowid> IN (?, ?, ?)", where <rowid> is a reference
** to some integer key column of a table B-Tree. In this case, use an
** intkey B-Tree to store the set of IN(...) values instead of the usual
** (slower) variable length keys B-Tree.
**
** If rMayHaveNull is non-zero, that means that the operation is an IN
** (not a SELECT or EXISTS) and that the RHS might contains NULLs.
** Furthermore, the IN is in a WHERE clause and that we really want
** to iterate over the RHS of the IN operator in order to quickly locate
** all corresponding LHS elements. All this routine does is initialize
** the register given by rMayHaveNull to NULL. Calling routines will take
** care of changing this register value to non-NULL if the RHS is NULL-free.
**
** If rMayHaveNull is zero, that means that the subquery is being used
** for membership testing only. There is no need to initialize any
** registers to indicate the presense or absence of NULLs on the RHS.
**
** For a SELECT or EXISTS operator, return the register that holds the
** result. For IN operators or if an error occurs, the return value is 0.
*/
#ifndef SQLITE_OMIT_SUBQUERY
int sqlite3CodeSubselect(
Parse *pParse, /* Parsing context */
Expr *pExpr, /* The IN, SELECT, or EXISTS operator */
int rMayHaveNull, /* Register that records whether NULLs exist in RHS */
int isRowid /* If true, LHS of IN operator is a rowid */
){
int testAddr = -1; /* One-time test address */
int rReg = 0; /* Register storing resulting */
Vdbe *v = sqlite3GetVdbe(pParse);
if( NEVER(v==0) ) return 0;
sqlite3ExprCachePush(pParse);
/* This code must be run in its entirety 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( !ExprHasAnyProperty(pExpr, EP_VarSelect) ){
testAddr = sqlite3CodeOnce(pParse);
}
#ifndef SQLITE_OMIT_EXPLAIN
if( pParse->explain==2 ){
char *zMsg = sqlite3MPrintf(
pParse->db, "EXECUTE %s%s SUBQUERY %d", testAddr>=0?"":"CORRELATED ",
pExpr->op==TK_IN?"LIST":"SCALAR", pParse->iNextSelectId
);
sqlite3VdbeAddOp4(v, OP_Explain, pParse->iSelectId, 0, 0, zMsg, P4_DYNAMIC);
}
#endif
switch( pExpr->op ){
case TK_IN: {
char affinity; /* Affinity of the LHS of the IN */
KeyInfo keyInfo; /* Keyinfo for the generated table */
int addr; /* Address of OP_OpenEphemeral instruction */
Expr *pLeft = pExpr->pLeft; /* the LHS of the IN operator */
if( rMayHaveNull ){
sqlite3VdbeAddOp2(v, OP_Null, 0, rMayHaveNull);
}
affinity = sqlite3ExprAffinity(pLeft);
/* Whether this is an 'x IN(SELECT...)' or an 'x IN(<exprlist>)'
** expression it is handled the same way. An ephemeral table is
** filled with single-field index keys representing the results
** from the SELECT or the <exprlist>.
**
** If the 'x' expression 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.
*/
pExpr->iTable = pParse->nTab++;
addr = sqlite3VdbeAddOp2(v, OP_OpenEphemeral, pExpr->iTable, !isRowid);
if( rMayHaveNull==0 ) sqlite3VdbeChangeP5(v, BTREE_UNORDERED);
memset(&keyInfo, 0, sizeof(keyInfo));
keyInfo.nField = 1;
if( ExprHasProperty(pExpr, EP_xIsSelect) ){
/* Case 1: expr IN (SELECT ...)
**
** Generate code to write the results of the select into the temporary
** table allocated and opened above.
*/
SelectDest dest;
ExprList *pEList;
assert( !isRowid );
sqlite3SelectDestInit(&dest, SRT_Set, pExpr->iTable);
dest.affinity = (u8)affinity;
assert( (pExpr->iTable&0x0000FFFF)==pExpr->iTable );
pExpr->x.pSelect->iLimit = 0;
if( sqlite3Select(pParse, pExpr->x.pSelect, &dest) ){
return 0;
}
pEList = pExpr->x.pSelect->pEList;
if( ALWAYS(pEList!=0 && pEList->nExpr>0) ){
keyInfo.aColl[0] = sqlite3BinaryCompareCollSeq(pParse, pExpr->pLeft,
pEList->a[0].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.
*/
int i;
ExprList *pList = pExpr->x.pList;
struct ExprList_item *pItem;
int r1, r2, r3;
if( !affinity ){
affinity = SQLITE_AFF_NONE;
}
keyInfo.aColl[0] = sqlite3ExprCollSeq(pParse, pExpr->pLeft);
/* Loop through each expression in <exprlist>. */
r1 = sqlite3GetTempReg(pParse);
r2 = sqlite3GetTempReg(pParse);
sqlite3VdbeAddOp2(v, OP_Null, 0, r2);
for(i=pList->nExpr, pItem=pList->a; i>0; i--, pItem++){
Expr *pE2 = pItem->pExpr;
int iValToIns;
/* 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( testAddr>=0 && !sqlite3ExprIsConstant(pE2) ){
sqlite3VdbeChangeToNoop(v, testAddr);
testAddr = -1;
}
/* Evaluate the expression and insert it into the temp table */
if( isRowid && sqlite3ExprIsInteger(pE2, &iValToIns) ){
sqlite3VdbeAddOp3(v, OP_InsertInt, pExpr->iTable, r2, iValToIns);
}else{
r3 = sqlite3ExprCodeTarget(pParse, pE2, r1);
if( isRowid ){
sqlite3VdbeAddOp2(v, OP_MustBeInt, r3,
sqlite3VdbeCurrentAddr(v)+2);
sqlite3VdbeAddOp3(v, OP_Insert, pExpr->iTable, r2, r3);
}else{
sqlite3VdbeAddOp4(v, OP_MakeRecord, r3, 1, r2, &affinity, 1);
sqlite3ExprCacheAffinityChange(pParse, r3, 1);
sqlite3VdbeAddOp2(v, OP_IdxInsert, pExpr->iTable, r2);
}
}
}
sqlite3ReleaseTempReg(pParse, r1);
sqlite3ReleaseTempReg(pParse, r2);
}
if( !isRowid ){
sqlite3VdbeChangeP4(v, addr, (void *)&keyInfo, P4_KEYINFO);
}
break;
}
case TK_EXISTS:
case TK_SELECT:
default: {
/* If this has to be a scalar SELECT. Generate code to put the
** value of this select in a memory cell and record the number
** of the memory cell in iColumn. If this is an EXISTS, write
** an integer 0 (not exists) or 1 (exists) into a memory cell
** and record that memory cell in iColumn.
*/
Select *pSel; /* SELECT statement to encode */
SelectDest dest; /* How to deal with SELECt result */
testcase( pExpr->op==TK_EXISTS );
testcase( pExpr->op==TK_SELECT );
assert( pExpr->op==TK_EXISTS || pExpr->op==TK_SELECT );
assert( ExprHasProperty(pExpr, EP_xIsSelect) );
pSel = pExpr->x.pSelect;
sqlite3SelectDestInit(&dest, 0, ++pParse->nMem);
if( pExpr->op==TK_SELECT ){
dest.eDest = SRT_Mem;
sqlite3VdbeAddOp2(v, OP_Null, 0, dest.iParm);
VdbeComment((v, "Init subquery result"));
}else{
dest.eDest = SRT_Exists;
sqlite3VdbeAddOp2(v, OP_Integer, 0, dest.iParm);
VdbeComment((v, "Init EXISTS result"));
}
sqlite3ExprDelete(pParse->db, pSel->pLimit);
pSel->pLimit = sqlite3PExpr(pParse, TK_INTEGER, 0, 0,
&sqlite3IntTokens[1]);
pSel->iLimit = 0;
if( sqlite3Select(pParse, pSel, &dest) ){
return 0;
}
rReg = dest.iParm;
ExprSetIrreducible(pExpr);
break;
}
}
if( testAddr>=0 ){
sqlite3VdbeJumpHere(v, testAddr);
}
sqlite3ExprCachePop(pParse, 1);
return rReg;
}
#endif /* SQLITE_OMIT_SUBQUERY */
#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 expression. The right-hand side (RHS)
** is an array of zero or more values. The expression is true if the LHS is
** contained within the RHS. The value of the expression is unknown (NULL)
** if the LHS is NULL or if the LHS is not contained within the RHS and the
** RHS contains one or more NULL values.
**
** This routine generates code will jump 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.
*/
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 */
char affinity; /* Comparison affinity to use */
int eType; /* Type of the RHS */
int r1; /* Temporary use register */
Vdbe *v; /* Statement under construction */
/* Compute the RHS. After this step, the table with cursor
** pExpr->iTable will contains the values that make up the RHS.
*/
v = pParse->pVdbe;
assert( v!=0 ); /* OOM detected prior to this routine */
VdbeNoopComment((v, "begin IN expr"));
eType = sqlite3FindInIndex(pParse, pExpr, &rRhsHasNull);
/* Figure out the affinity to use to create a key from the results
** of the expression. affinityStr stores a static string suitable for
** P4 of OP_MakeRecord.
*/
affinity = comparisonAffinity(pExpr);
/* Code the LHS, the <expr> from "<expr> IN (...)".
*/
sqlite3ExprCachePush(pParse);
r1 = sqlite3GetTempReg(pParse);
sqlite3ExprCode(pParse, pExpr->pLeft, r1);
/* If the LHS is NULL, then the result is either false or NULL depending
** on whether the RHS is empty or not, respectively.
*/
if( destIfNull==destIfFalse ){
/* Shortcut for the common case where the false and NULL outcomes are
** the same. */
sqlite3VdbeAddOp2(v, OP_IsNull, r1, destIfNull);
}else{
int addr1 = sqlite3VdbeAddOp1(v, OP_NotNull, r1);
sqlite3VdbeAddOp2(v, OP_Rewind, pExpr->iTable, destIfFalse);
sqlite3VdbeAddOp2(v, OP_Goto, 0, destIfNull);
sqlite3VdbeJumpHere(v, addr1);
}
if( eType==IN_INDEX_ROWID ){
/* In this case, the RHS is the ROWID of table b-tree
*/
sqlite3VdbeAddOp2(v, OP_MustBeInt, r1, destIfFalse);
sqlite3VdbeAddOp3(v, OP_NotExists, pExpr->iTable, destIfFalse, r1);
}else{
/* In this case, the RHS is an index b-tree.
*/
sqlite3VdbeAddOp4(v, OP_Affinity, r1, 1, 0, &affinity, 1);
/* If the set membership test fails, then the result of the
** "x IN (...)" expression must be either 0 or NULL. If the set
** contains no NULL values, then the result is 0. If the set
** contains one or more NULL values, then the result of the
** expression is also NULL.
*/
if( rRhsHasNull==0 || destIfFalse==destIfNull ){
/* This branch runs if it is known at compile time that the RHS
** cannot contain NULL values. This happens as the result
** of a "NOT NULL" constraint in the database schema.
**
** Also run this branch if NULL is equivalent to FALSE
** for this particular IN operator.
*/
sqlite3VdbeAddOp4Int(v, OP_NotFound, pExpr->iTable, destIfFalse, r1, 1);
}else{
/* In this branch, the RHS of the IN might contain a NULL and
** the presence of a NULL on the RHS makes a difference in the
** outcome.
*/
int j1, j2, j3;
/* First check to see if the LHS is contained in the RHS. If so,
** then the presence of NULLs in the RHS does not matter, so jump
** over all of the code that follows.
*/
j1 = sqlite3VdbeAddOp4Int(v, OP_Found, pExpr->iTable, 0, r1, 1);
/* Here we begin generating code that runs if the LHS is not
** contained within the RHS. Generate additional code that
** tests the RHS for NULLs. If the RHS contains a NULL then
** jump to destIfNull. If there are no NULLs in the RHS then
** jump to destIfFalse.
*/
j2 = sqlite3VdbeAddOp1(v, OP_NotNull, rRhsHasNull);
j3 = sqlite3VdbeAddOp4Int(v, OP_Found, pExpr->iTable, 0, rRhsHasNull, 1);
sqlite3VdbeAddOp2(v, OP_Integer, -1, rRhsHasNull);
sqlite3VdbeJumpHere(v, j3);
sqlite3VdbeAddOp2(v, OP_AddImm, rRhsHasNull, 1);
sqlite3VdbeJumpHere(v, j2);
/* Jump to the appropriate target depending on whether or not
** the RHS contains a NULL
*/
sqlite3VdbeAddOp2(v, OP_If, rRhsHasNull, destIfNull);
sqlite3VdbeAddOp2(v, OP_Goto, 0, destIfFalse);
/* The OP_Found at the top of this branch jumps here when true,
** causing the overall IN expression evaluation to fall through.
*/
sqlite3VdbeJumpHere(v, j1);
}
}
sqlite3ReleaseTempReg(pParse, r1);
sqlite3ExprCachePop(pParse, 1);
VdbeComment((v, "end IN expr"));
}
#endif /* SQLITE_OMIT_SUBQUERY */
/*
** Duplicate an 8-byte value
*/
static char *dup8bytes(Vdbe *v, const char *in){
char *out = sqlite3DbMallocRaw(sqlite3VdbeDb(v), 8);
if( out ){
memcpy(out, in, 8);
}
return out;
}
#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;
char *zV;
sqlite3AtoF(z, &value, sqlite3Strlen30(z), SQLITE_UTF8);
assert( !sqlite3IsNaN(value) ); /* The new AtoF never returns NaN */
if( negateFlag ) value = -value;
zV = dup8bytes(v, (char*)&value);
sqlite3VdbeAddOp4(v, OP_Real, 0, iMem, 0, zV, 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 = sqlite3Atoi64(z, &value, sqlite3Strlen30(z), SQLITE_UTF8);
if( c==0 || (c==2 && negFlag) ){
char *zV;
if( negFlag ){ value = c==2 ? SMALLEST_INT64 : -value; }
zV = dup8bytes(v, (char*)&value);
sqlite3VdbeAddOp4(v, OP_Int64, 0, iMem, 0, zV, P4_INT64);
}else{
#ifdef SQLITE_OMIT_FLOATING_POINT
sqlite3ErrorMsg(pParse, "oversized integer: %s%s", negFlag ? "-" : "", z);
#else
codeReal(v, z, negFlag, iMem);
#endif
}
}
}
/*
** Clear a cache entry.
*/
static void cacheEntryClear(Parse *pParse, struct yColCache *p){
if( p->tempReg ){
if( pParse->nTempReg<ArraySize(pParse->aTempReg) ){
pParse->aTempReg[pParse->nTempReg++] = p->iReg;
}
p->tempReg = 0;
}
}
/*
** Record in the column cache that a particular column from a
** particular table is stored in a particular register.
*/
void sqlite3ExprCacheStore(Parse *pParse, int iTab, int iCol, int iReg){
int i;
int minLru;
int idxLru;
struct yColCache *p;
assert( iReg>0 ); /* Register numbers are always positive */
assert( iCol>=-1 && iCol<32768 ); /* Finite column numbers */
/* The SQLITE_ColumnCache flag disables the column cache. This is used
** for testing only - to verify that SQLite always gets the same answer
** with and without the column cache.
*/
if( pParse->db->flags & SQLITE_ColumnCache ) return;
/* First replace any existing entry.
**
** Actually, the way the column cache is currently used, we are guaranteed
** that the object will never already be in cache. Verify this guarantee.
*/
#ifndef NDEBUG
for(i=0, p=pParse->aColCache; i<SQLITE_N_COLCACHE; i++, p++){
assert( p->iReg==0 || p->iTable!=iTab || p->iColumn!=iCol );
}
#endif
/* Find an empty slot and replace it */
for(i=0, p=pParse->aColCache; i<SQLITE_N_COLCACHE; i++, p++){
if( p->iReg==0 ){
p->iLevel = pParse->iCacheLevel;
p->iTable = iTab;
p->iColumn = iCol;
p->iReg = iReg;
p->tempReg = 0;
p->lru = pParse->iCacheCnt++;
return;
}
}
/* Replace the last recently used */
minLru = 0x7fffffff;
idxLru = -1;
for(i=0, p=pParse->aColCache; i<SQLITE_N_COLCACHE; i++, p++){
if( p->lru<minLru ){
idxLru = i;
minLru = p->lru;
}
}
if( ALWAYS(idxLru>=0) ){
p = &pParse->aColCache[idxLru];
p->iLevel = pParse->iCacheLevel;
p->iTable = iTab;
p->iColumn = iCol;
p->iReg = iReg;
p->tempReg = 0;
p->lru = pParse->iCacheCnt++;
return;
}
}
/*
** Indicate that registers between iReg..iReg+nReg-1 are being overwritten.
** Purge the range of registers from the column cache.
*/
void sqlite3ExprCacheRemove(Parse *pParse, int iReg, int nReg){
int i;
int iLast = iReg + nReg - 1;
struct yColCache *p;
for(i=0, p=pParse->aColCache; i<SQLITE_N_COLCACHE; i++, p++){
int r = p->iReg;
if( r>=iReg && r<=iLast ){
cacheEntryClear(pParse, p);
p->iReg = 0;
}
}
}
/*
** Remember the current column cache context. Any new entries added
** added to the column cache after this call are removed when the
** corresponding pop occurs.
*/
void sqlite3ExprCachePush(Parse *pParse){
pParse->iCacheLevel++;
}
/*
** Remove from the column cache any entries that were added since the
** the previous N Push operations. In other words, restore the cache
** to the state it was in N Pushes ago.
*/
void sqlite3ExprCachePop(Parse *pParse, int N){
int i;
struct yColCache *p;
assert( N>0 );
assert( pParse->iCacheLevel>=N );
pParse->iCacheLevel -= N;
for(i=0, p=pParse->aColCache; i<SQLITE_N_COLCACHE; i++, p++){
if( p->iReg && p->iLevel>pParse->iCacheLevel ){
cacheEntryClear(pParse, p);
p->iReg = 0;
}
}
}
/*
** When a cached column is reused, make sure that its register is
** no longer available as a temp register. ticket #3879: that same
** register might be in the cache in multiple places, so be sure to
** get them all.
*/
static void sqlite3ExprCachePinRegister(Parse *pParse, int iReg){
int i;
struct yColCache *p;
for(i=0, p=pParse->aColCache; i<SQLITE_N_COLCACHE; i++, p++){
if( p->iReg==iReg ){
p->tempReg = 0;
}
}
}
/*
** Generate code to extract the value of the iCol-th column of a table.
*/
void sqlite3ExprCodeGetColumnOfTable(
Vdbe *v, /* The VDBE under construction */
Table *pTab, /* The table containing the value */
int iTabCur, /* The cursor for this table */
int iCol, /* Index of the column to extract */
int regOut /* Extract the valud into this register */
){
if( iCol<0 || iCol==pTab->iPKey ){
sqlite3VdbeAddOp2(v, OP_Rowid, iTabCur, regOut);
}else{
int op = IsVirtual(pTab) ? OP_VColumn : OP_Column;
sqlite3VdbeAddOp3(v, op, iTabCur, iCol, regOut);
}
if( iCol>=0 ){
sqlite3ColumnDefault(v, pTab, iCol, regOut);
}
}
/*
** Generate code that will extract the iColumn-th column from
** table pTab and store the column value in a register. An effort
** is made to store the column value in register iReg, but this is
** not guaranteed. The location of the column value is returned.
**
** 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 */
){
Vdbe *v = pParse->pVdbe;
int i;
struct yColCache *p;
for(i=0, p=pParse->aColCache; i<SQLITE_N_COLCACHE; i++, p++){
if( p->iReg>0 && p->iTable==iTable && p->iColumn==iColumn ){
p->lru = pParse->iCacheCnt++;
sqlite3ExprCachePinRegister(pParse, p->iReg);
return p->iReg;
}
}
assert( v!=0 );
sqlite3ExprCodeGetColumnOfTable(v, pTab, iTable, iColumn, iReg);
if( p5 ){
sqlite3VdbeChangeP5(v, p5);
}else{
sqlite3ExprCacheStore(pParse, iTable, iColumn, iReg);
}
return iReg;
}
/*
** Clear all column cache entries.
*/
void sqlite3ExprCacheClear(Parse *pParse){
int i;
struct yColCache *p;
for(i=0, p=pParse->aColCache; i<SQLITE_N_COLCACHE; i++, p++){
if( p->iReg ){
cacheEntryClear(pParse, p);
p->iReg = 0;
}
}
}
/*
** Record the fact that an affinity change has occurred on iCount
** registers starting with iStart.
*/
void sqlite3ExprCacheAffinityChange(Parse *pParse, int iStart, int iCount){
sqlite3ExprCacheRemove(pParse, iStart, iCount);
}
/*
** Generate code to move content from registers iFrom...iFrom+nReg-1
** over to iTo..iTo+nReg-1. Keep the column cache up-to-date.
*/
void sqlite3ExprCodeMove(Parse *pParse, int iFrom, int iTo, int nReg){
int i;
struct yColCache *p;
if( NEVER(iFrom==iTo) ) return;
sqlite3VdbeAddOp3(pParse->pVdbe, OP_Move, iFrom, iTo, nReg);
for(i=0, p=pParse->aColCache; i<SQLITE_N_COLCACHE; i++, p++){
int x = p->iReg;
if( x>=iFrom && x<iFrom+nReg ){
p->iReg += iTo-iFrom;
}
}
}
/*
** Generate code to copy content from registers iFrom...iFrom+nReg-1
** over to iTo..iTo+nReg-1.
*/
void sqlite3ExprCodeCopy(Parse *pParse, int iFrom, int iTo, int nReg){
int i;
if( NEVER(iFrom==iTo) ) return;
for(i=0; i<nReg; i++){
sqlite3VdbeAddOp2(pParse->pVdbe, OP_Copy, iFrom+i, iTo+i);
}
}
#if defined(SQLITE_DEBUG) || defined(SQLITE_COVERAGE_TEST)
/*
** Return true if any register in the range iFrom..iTo (inclusive)
** is used as part of the column cache.
**
** This routine is used within assert() and testcase() macros only
** and does not appear in a normal build.
*/
static int usedAsColumnCache(Parse *pParse, int iFrom, int iTo){
int i;
struct yColCache *p;
for(i=0, p=pParse->aColCache; i<SQLITE_N_COLCACHE; i++, p++){
int r = p->iReg;
if( r>=iFrom && r<=iTo ) return 1; /*NO_TEST*/
}
return 0;
}
#endif /* SQLITE_DEBUG || SQLITE_COVERAGE_TEST */
/*
** 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, r3, r4; /* Various register numbers */
sqlite3 *db = pParse->db; /* The database connection */
assert( target>0 && target<=pParse->nMem );
if( v==0 ){
assert( pParse->db->mallocFailed );
return 0;
}
if( pExpr==0 ){
op = TK_NULL;
}else{
op = pExpr->op;
}
switch( op ){
case TK_AGG_COLUMN: {
AggInfo *pAggInfo = pExpr->pAggInfo;
struct AggInfo_col *pCol = &pAggInfo->aCol[pExpr->iAgg];
if( !pAggInfo->directMode ){
assert( pCol->iMem>0 );
inReg = pCol->iMem;
break;
}else if( pAggInfo->useSortingIdx ){
sqlite3VdbeAddOp3(v, OP_Column, pAggInfo->sortingIdxPTab,
pCol->iSorterColumn, target);
break;
}
/* Otherwise, fall thru into the TK_COLUMN case */
}
case TK_COLUMN: {
if( pExpr->iTable<0 ){
/* This only happens when coding check constraints */
assert( pParse->ckBase>0 );
inReg = pExpr->iColumn + pParse->ckBase;
}else{
inReg = sqlite3ExprCodeGetColumn(pParse, pExpr->pTab,
pExpr->iColumn, pExpr->iTable, target,
pExpr->op2);
}
break;
}
case TK_INTEGER: {
codeInteger(pParse, pExpr, 0, target);
break;
}
#ifndef SQLITE_OMIT_FLOATING_POINT
case TK_FLOAT: {
assert( !ExprHasProperty(pExpr, EP_IntValue) );
codeReal(v, pExpr->u.zToken, 0, target);
break;
}
#endif
case TK_STRING: {
assert( !ExprHasProperty(pExpr, EP_IntValue) );
sqlite3VdbeAddOp4(v, OP_String8, 0, target, 0, pExpr->u.zToken, 0);
break;
}
case TK_NULL: {
sqlite3VdbeAddOp2(v, OP_Null, 0, target);
break;
}
#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);
break;
}
#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);
if( pExpr->u.zToken[1]!=0 ){
assert( pExpr->u.zToken[0]=='?'
|| strcmp(pExpr->u.zToken, pParse->azVar[pExpr->iColumn-1])==0 );
sqlite3VdbeChangeP4(v, -1, pParse->azVar[pExpr->iColumn-1], P4_STATIC);
}
break;
}
case TK_REGISTER: {
inReg = pExpr->iTable;
break;
}
case TK_AS: {
inReg = sqlite3ExprCodeTarget(pParse, pExpr->pLeft, target);
break;
}
#ifndef SQLITE_OMIT_CAST
case TK_CAST: {
/* Expressions of the form: CAST(pLeft AS token) */
int aff, to_op;
inReg = sqlite3ExprCodeTarget(pParse, pExpr->pLeft, target);
assert( !ExprHasProperty(pExpr, EP_IntValue) );
aff = sqlite3AffinityType(pExpr->u.zToken);
to_op = aff - SQLITE_AFF_TEXT + OP_ToText;
assert( to_op==OP_ToText || aff!=SQLITE_AFF_TEXT );
assert( to_op==OP_ToBlob || aff!=SQLITE_AFF_NONE );
assert( to_op==OP_ToNumeric || aff!=SQLITE_AFF_NUMERIC );
assert( to_op==OP_ToInt || aff!=SQLITE_AFF_INTEGER );
assert( to_op==OP_ToReal || aff!=SQLITE_AFF_REAL );
testcase( to_op==OP_ToText );
testcase( to_op==OP_ToBlob );
testcase( to_op==OP_ToNumeric );
testcase( to_op==OP_ToInt );
testcase( to_op==OP_ToReal );
if( inReg!=target ){
sqlite3VdbeAddOp2(v, OP_SCopy, inReg, target);
inReg = target;
}
sqlite3VdbeAddOp1(v, to_op, inReg);
testcase( usedAsColumnCache(pParse, inReg, inReg) );
sqlite3ExprCacheAffinityChange(pParse, inReg, 1);
break;
}
#endif /* SQLITE_OMIT_CAST */
case TK_LT:
case TK_LE:
case TK_GT:
case TK_GE:
case TK_NE:
case TK_EQ: {
assert( TK_LT==OP_Lt );
assert( TK_LE==OP_Le );
assert( TK_GT==OP_Gt );
assert( TK_GE==OP_Ge );
assert( TK_EQ==OP_Eq );
assert( TK_NE==OP_Ne );
testcase( op==TK_LT );
testcase( op==TK_LE );
testcase( op==TK_GT );
testcase( op==TK_GE );
testcase( op==TK_EQ );
testcase( op==TK_NE );
r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, &regFree1);
r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, &regFree2);
codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op,
r1, r2, inReg, SQLITE_STOREP2);
testcase( regFree1==0 );
testcase( regFree2==0 );
break;
}
case TK_IS:
case TK_ISNOT: {
testcase( op==TK_IS );
testcase( op==TK_ISNOT );
r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, &regFree1);
r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, &regFree2);
op = (op==TK_IS) ? TK_EQ : TK_NE;
codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op,
r1, r2, inReg, SQLITE_STOREP2 | SQLITE_NULLEQ);
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 );
assert( TK_OR==OP_Or );
assert( TK_PLUS==OP_Add );
assert( TK_MINUS==OP_Subtract );
assert( TK_REM==OP_Remainder );
assert( TK_BITAND==OP_BitAnd );
assert( TK_BITOR==OP_BitOr );
assert( TK_SLASH==OP_Divide );
assert( TK_LSHIFT==OP_ShiftLeft );
assert( TK_RSHIFT==OP_ShiftRight );
assert( TK_CONCAT==OP_Concat );
testcase( op==TK_AND );
testcase( op==TK_OR );
testcase( op==TK_PLUS );
testcase( op==TK_MINUS );
testcase( op==TK_REM );
testcase( op==TK_BITAND );
testcase( op==TK_BITOR );
testcase( op==TK_SLASH );
testcase( op==TK_LSHIFT );
testcase( op==TK_RSHIFT );
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);
#ifndef SQLITE_OMIT_FLOATING_POINT
}else if( pLeft->op==TK_FLOAT ){
assert( !ExprHasProperty(pExpr, EP_IntValue) );
codeReal(v, pLeft->u.zToken, 1, target);
#endif
}else{
regFree1 = r1 = sqlite3GetTempReg(pParse);
sqlite3VdbeAddOp2(v, OP_Integer, 0, r1);
r2 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, &regFree2);
sqlite3VdbeAddOp3(v, OP_Subtract, r2, r1, target);
testcase( regFree2==0 );
}
inReg = target;
break;
}
case TK_BITNOT:
case TK_NOT: {
assert( TK_BITNOT==OP_BitNot );
assert( TK_NOT==OP_Not );
testcase( op==TK_BITNOT );
testcase( op==TK_NOT );
r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, &regFree1);
testcase( regFree1==0 );
inReg = target;
sqlite3VdbeAddOp2(v, op, r1, inReg);
break;
}
case TK_ISNULL:
case TK_NOTNULL: {
int addr;
assert( TK_ISNULL==OP_IsNull );
assert( TK_NOTNULL==OP_NotNull );
testcase( op==TK_ISNULL );
testcase( op==TK_NOTNULL );
sqlite3VdbeAddOp2(v, OP_Integer, 1, target);
r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, &regFree1);
testcase( regFree1==0 );
addr = sqlite3VdbeAddOp1(v, op, r1);
sqlite3VdbeAddOp2(v, OP_AddImm, target, -1);
sqlite3VdbeJumpHere(v, addr);
break;
}
case TK_AGG_FUNCTION: {
AggInfo *pInfo = pExpr->pAggInfo;
if( pInfo==0 ){
assert( !ExprHasProperty(pExpr, EP_IntValue) );
sqlite3ErrorMsg(pParse, "misuse of aggregate: %s()", pExpr->u.zToken);
}else{
inReg = pInfo->aFunc[pExpr->iAgg].iMem;
}
break;
}
case TK_CONST_FUNC:
case TK_FUNCTION: {
ExprList *pFarg; /* List of function arguments */
int nFarg; /* Number of function arguments */
FuncDef *pDef; /* The function definition object */
int nId; /* Length of the function name in bytes */
const char *zId; /* The function name */
int constMask = 0; /* Mask of function arguments that are constant */
int i; /* Loop counter */
u8 enc = ENC(db); /* The text encoding used by this database */
CollSeq *pColl = 0; /* A collating sequence */
assert( !ExprHasProperty(pExpr, EP_xIsSelect) );
testcase( op==TK_CONST_FUNC );
testcase( op==TK_FUNCTION );
if( ExprHasAnyProperty(pExpr, EP_TokenOnly) ){
pFarg = 0;
}else{
pFarg = pExpr->x.pList;
}
nFarg = pFarg ? pFarg->nExpr : 0;
assert( !ExprHasProperty(pExpr, EP_IntValue) );
zId = pExpr->u.zToken;
nId = sqlite3Strlen30(zId);
pDef = sqlite3FindFunction(db, zId, nId, nFarg, enc, 0);
if( pDef==0 ){
sqlite3ErrorMsg(pParse, "unknown function: %.*s()", nId, zId);
break;
}
/* Attempt a direct implementation of the built-in COALESCE() and
** IFNULL() functions. This avoids unnecessary evalation of
** arguments past the first non-NULL argument.
*/
if( pDef->flags & SQLITE_FUNC_COALESCE ){
int endCoalesce = sqlite3VdbeMakeLabel(v);
assert( nFarg>=2 );
sqlite3ExprCode(pParse, pFarg->a[0].pExpr, target);
for(i=1; i<nFarg; i++){
sqlite3VdbeAddOp2(v, OP_NotNull, target, endCoalesce);
sqlite3ExprCacheRemove(pParse, target, 1);
sqlite3ExprCachePush(pParse);
sqlite3ExprCode(pParse, pFarg->a[i].pExpr, target);
sqlite3ExprCachePop(pParse, 1);
}
sqlite3VdbeResolveLabel(v, endCoalesce);
break;
}
if( pFarg ){
r1 = sqlite3GetTempRange(pParse, nFarg);
/* For length() and typeof() functions with a column argument,
** set the P5 parameter to the OP_Column opcode to OPFLAG_LENGTHARG
** or OPFLAG_TYPEOFARG respectively, to avoid unnecessary data
** loading.
*/
if( (pDef->flags & (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 );
testcase( pDef->flags==SQLITE_FUNC_LENGTH );
pFarg->a[0].pExpr->op2 = pDef->flags;
}
}
sqlite3ExprCachePush(pParse); /* Ticket 2ea2425d34be */
sqlite3ExprCodeExprList(pParse, pFarg, r1, 1);
sqlite3ExprCachePop(pParse, 1); /* Ticket 2ea2425d34be */
}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 && (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
for(i=0; i<nFarg; i++){
if( i<32 && sqlite3ExprIsConstant(pFarg->a[i].pExpr) ){
constMask |= (1<<i);
}
if( (pDef->flags & SQLITE_FUNC_NEEDCOLL)!=0 && !pColl ){
pColl = sqlite3ExprCollSeq(pParse, pFarg->a[i].pExpr);
}
}
if( pDef->flags & SQLITE_FUNC_NEEDCOLL ){
if( !pColl ) pColl = db->pDfltColl;
sqlite3VdbeAddOp4(v, OP_CollSeq, 0, 0, 0, (char *)pColl, P4_COLLSEQ);
}
sqlite3VdbeAddOp4(v, OP_Function, constMask, r1, target,
(char*)pDef, P4_FUNCDEF);
sqlite3VdbeChangeP5(v, (u8)nFarg);
if( nFarg ){
sqlite3ReleaseTempRange(pParse, r1, nFarg);
}
break;
}
#ifndef SQLITE_OMIT_SUBQUERY
case TK_EXISTS:
case TK_SELECT: {
testcase( op==TK_EXISTS );
testcase( op==TK_SELECT );
inReg = sqlite3CodeSubselect(pParse, pExpr, 0, 0);
break;
}
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);
break;
}
#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: {
Expr *pLeft = pExpr->pLeft;
struct ExprList_item *pLItem = pExpr->x.pList->a;
Expr *pRight = pLItem->pExpr;
r1 = sqlite3ExprCodeTemp(pParse, pLeft, &regFree1);
r2 = sqlite3ExprCodeTemp(pParse, pRight, &regFree2);
testcase( regFree1==0 );
testcase( regFree2==0 );
r3 = sqlite3GetTempReg(pParse);
r4 = sqlite3GetTempReg(pParse);
codeCompare(pParse, pLeft, pRight, OP_Ge,
r1, r2, r3, SQLITE_STOREP2);
pLItem++;
pRight = pLItem->pExpr;
sqlite3ReleaseTempReg(pParse, regFree2);
r2 = sqlite3ExprCodeTemp(pParse, pRight, &regFree2);
testcase( regFree2==0 );
codeCompare(pParse, pLeft, pRight, OP_Le, r1, r2, r4, SQLITE_STOREP2);
sqlite3VdbeAddOp3(v, OP_And, r3, r4, target);
sqlite3ReleaseTempReg(pParse, r3);
sqlite3ReleaseTempReg(pParse, r4);
break;
}
case TK_UPLUS: {
inReg = sqlite3ExprCodeTarget(pParse, pExpr->pLeft, target);
break;
}
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->iColumn<pTab->nCol );
assert( pTab->iPKey<0 || pExpr->iColumn!=pTab->iPKey );
assert( p1>=0 && p1<(pTab->nCol*2+2) );
sqlite3VdbeAddOp2(v, OP_Param, p1, target);
VdbeComment((v, "%s.%s -> $%d",
(pExpr->iTable ? "new" : "old"),
(pExpr->iColumn<0 ? "rowid" : pExpr->pTab->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. */
if( pExpr->iColumn>=0
&& pTab->aCol[pExpr->iColumn].affinity==SQLITE_AFF_REAL
){
sqlite3VdbeAddOp1(v, OP_RealAffinity, target);
}
#endif
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 pExpr->pRight. The Y is also optional. If there is no
** ELSE clause and no other term matches, then the result of the
** exprssion 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 cacheX; /* Cached expression X */
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 % 2) == 0);
assert(pExpr->x.pList->nExpr > 0);
pEList = pExpr->x.pList;
aListelem = pEList->a;
nExpr = pEList->nExpr;
endLabel = sqlite3VdbeMakeLabel(v);
if( (pX = pExpr->pLeft)!=0 ){
cacheX = *pX;
testcase( pX->op==TK_COLUMN );
testcase( pX->op==TK_REGISTER );
cacheX.iTable = sqlite3ExprCodeTemp(pParse, pX, &regFree1);
testcase( regFree1==0 );
cacheX.op = TK_REGISTER;
opCompare.op = TK_EQ;
opCompare.pLeft = &cacheX;
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; i=i+2){
sqlite3ExprCachePush(pParse);
if( pX ){
assert( pTest!=0 );
opCompare.pRight = aListelem[i].pExpr;
}else{
pTest = aListelem[i].pExpr;
}
nextCase = sqlite3VdbeMakeLabel(v);
testcase( pTest->op==TK_COLUMN );
sqlite3ExprIfFalse(pParse, pTest, nextCase, SQLITE_JUMPIFNULL);
testcase( aListelem[i+1].pExpr->op==TK_COLUMN );
testcase( aListelem[i+1].pExpr->op==TK_REGISTER );
sqlite3ExprCode(pParse, aListelem[i+1].pExpr, target);
sqlite3VdbeAddOp2(v, OP_Goto, 0, endLabel);
sqlite3ExprCachePop(pParse, 1);
sqlite3VdbeResolveLabel(v, nextCase);
}
if( pExpr->pRight ){
sqlite3ExprCachePush(pParse);
sqlite3ExprCode(pParse, pExpr->pRight, target);
sqlite3ExprCachePop(pParse, 1);
}else{
sqlite3VdbeAddOp2(v, OP_Null, 0, target);
}
assert( 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);
}else{
sqlite3HaltConstraint(pParse, pExpr->affinity, pExpr->u.zToken, 0);
}
break;
}
#endif
}
sqlite3ReleaseTempReg(pParse, regFree1);
sqlite3ReleaseTempReg(pParse, regFree2);
return inReg;
}
/*
** 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.
*/
int sqlite3ExprCodeTemp(Parse *pParse, Expr *pExpr, int *pReg){
int r1 = sqlite3GetTempReg(pParse);
int 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.
*/
int sqlite3ExprCode(Parse *pParse, Expr *pExpr, int target){
int inReg;
assert( target>0 && target<=pParse->nMem );
if( pExpr && pExpr->op==TK_REGISTER ){
sqlite3VdbeAddOp2(pParse->pVdbe, OP_Copy, pExpr->iTable, target);
}else{
inReg = sqlite3ExprCodeTarget(pParse, pExpr, target);
assert( pParse->pVdbe || pParse->db->mallocFailed );
if( inReg!=target && pParse->pVdbe ){
sqlite3VdbeAddOp2(pParse->pVdbe, OP_SCopy, inReg, target);
}
}
return target;
}
/*
** Generate code that evalutes 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.
*/
int sqlite3ExprCodeAndCache(Parse *pParse, Expr *pExpr, int target){
Vdbe *v = pParse->pVdbe;
int inReg;
inReg = sqlite3ExprCode(pParse, pExpr, target);
assert( target>0 );
/* This routine is called for terms to INSERT or UPDATE. And the only
** other place where expressions can be converted into TK_REGISTER is
** in WHERE clause processing. So as currently implemented, there is
** no way for a TK_REGISTER to exist here. But it seems prudent to
** keep the ALWAYS() in case the conditions above change with future
** modifications or enhancements. */
if( ALWAYS(pExpr->op!=TK_REGISTER) ){
int iMem;
iMem = ++pParse->nMem;
sqlite3VdbeAddOp2(v, OP_Copy, inReg, iMem);
pExpr->iTable = iMem;
pExpr->op2 = pExpr->op;
pExpr->op = TK_REGISTER;
}
return inReg;
}
#if defined(SQLITE_ENABLE_TREE_EXPLAIN)
/*
** Generate a human-readable explanation of an expression tree.
*/
void sqlite3ExplainExpr(Vdbe *pOut, Expr *pExpr){
int op; /* The opcode being coded */
const char *zBinOp = 0; /* Binary operator */
const char *zUniOp = 0; /* Unary operator */
if( pExpr==0 ){
op = TK_NULL;
}else{
op = pExpr->op;
}
switch( op ){
case TK_AGG_COLUMN: {
sqlite3ExplainPrintf(pOut, "AGG{%d:%d}",
pExpr->iTable, pExpr->iColumn);
break;
}
case TK_COLUMN: {
if( pExpr->iTable<0 ){
/* This only happens when coding check constraints */
sqlite3ExplainPrintf(pOut, "COLUMN(%d)", pExpr->iColumn);
}else{
sqlite3ExplainPrintf(pOut, "{%d:%d}",
pExpr->iTable, pExpr->iColumn);
}
break;
}
case TK_INTEGER: {
if( pExpr->flags & EP_IntValue ){
sqlite3ExplainPrintf(pOut, "%d", pExpr->u.iValue);
}else{
sqlite3ExplainPrintf(pOut, "%s", pExpr->u.zToken);
}
break;
}
#ifndef SQLITE_OMIT_FLOATING_POINT
case TK_FLOAT: {
sqlite3ExplainPrintf(pOut,"%s", pExpr->u.zToken);
break;
}
#endif
case TK_STRING: {
sqlite3ExplainPrintf(pOut,"%Q", pExpr->u.zToken);
break;
}
case TK_NULL: {
sqlite3ExplainPrintf(pOut,"NULL");
break;
}
#ifndef SQLITE_OMIT_BLOB_LITERAL
case TK_BLOB: {
sqlite3ExplainPrintf(pOut,"%s", pExpr->u.zToken);
break;
}
#endif
case TK_VARIABLE: {
sqlite3ExplainPrintf(pOut,"VARIABLE(%s,%d)",
pExpr->u.zToken, pExpr->iColumn);
break;
}
case TK_REGISTER: {
sqlite3ExplainPrintf(pOut,"REGISTER(%d)", pExpr->iTable);
break;
}
case TK_AS: {
sqlite3ExplainExpr(pOut, pExpr->pLeft);
break;
}
#ifndef SQLITE_OMIT_CAST
case TK_CAST: {
/* Expressions of the form: CAST(pLeft AS token) */
const char *zAff = "unk";
switch( sqlite3AffinityType(pExpr->u.zToken) ){
case SQLITE_AFF_TEXT: zAff = "TEXT"; break;
case SQLITE_AFF_NONE: zAff = "NONE"; break;
case SQLITE_AFF_NUMERIC: zAff = "NUMERIC"; break;
case SQLITE_AFF_INTEGER: zAff = "INTEGER"; break;
case SQLITE_AFF_REAL: zAff = "REAL"; break;
}
sqlite3ExplainPrintf(pOut, "CAST-%s(", zAff);
sqlite3ExplainExpr(pOut, pExpr->pLeft);
sqlite3ExplainPrintf(pOut, ")");
break;
}
#endif /* SQLITE_OMIT_CAST */
case TK_LT: zBinOp = "LT"; break;
case TK_LE: zBinOp = "LE"; break;
case TK_GT: zBinOp = "GT"; break;
case TK_GE: zBinOp = "GE"; break;
case TK_NE: zBinOp = "NE"; break;
case TK_EQ: zBinOp = "EQ"; break;
case TK_IS: zBinOp = "IS"; break;
case TK_ISNOT: zBinOp = "ISNOT"; break;
case TK_AND: zBinOp = "AND"; break;
case TK_OR: zBinOp = "OR"; break;
case TK_PLUS: zBinOp = "ADD"; break;
case TK_STAR: zBinOp = "MUL"; break;
case TK_MINUS: zBinOp = "SUB"; break;
case TK_REM: zBinOp = "REM"; break;
case TK_BITAND: zBinOp = "BITAND"; break;
case TK_BITOR: zBinOp = "BITOR"; break;
case TK_SLASH: zBinOp = "DIV"; break;
case TK_LSHIFT: zBinOp = "LSHIFT"; break;
case TK_RSHIFT: zBinOp = "RSHIFT"; break;
case TK_CONCAT: zBinOp = "CONCAT"; break;
case TK_UMINUS: zUniOp = "UMINUS"; break;
case TK_UPLUS: zUniOp = "UPLUS"; break;
case TK_BITNOT: zUniOp = "BITNOT"; break;
case TK_NOT: zUniOp = "NOT"; break;
case TK_ISNULL: zUniOp = "ISNULL"; break;
case TK_NOTNULL: zUniOp = "NOTNULL"; break;
case TK_AGG_FUNCTION:
case TK_CONST_FUNC:
case TK_FUNCTION: {
ExprList *pFarg; /* List of function arguments */
if( ExprHasAnyProperty(pExpr, EP_TokenOnly) ){
pFarg = 0;
}else{
pFarg = pExpr->x.pList;
}
sqlite3ExplainPrintf(pOut, "%sFUNCTION:%s(",
op==TK_AGG_FUNCTION ? "AGG_" : "",
pExpr->u.zToken);
if( pFarg ){
sqlite3ExplainExprList(pOut, pFarg);
}
sqlite3ExplainPrintf(pOut, ")");
break;
}
#ifndef SQLITE_OMIT_SUBQUERY
case TK_EXISTS: {
sqlite3ExplainPrintf(pOut, "EXISTS(");
sqlite3ExplainSelect(pOut, pExpr->x.pSelect);
sqlite3ExplainPrintf(pOut,")");
break;
}
case TK_SELECT: {
sqlite3ExplainPrintf(pOut, "(");
sqlite3ExplainSelect(pOut, pExpr->x.pSelect);
sqlite3ExplainPrintf(pOut, ")");
break;
}
case TK_IN: {
sqlite3ExplainPrintf(pOut, "IN(");
sqlite3ExplainExpr(pOut, pExpr->pLeft);
sqlite3ExplainPrintf(pOut, ",");
if( ExprHasProperty(pExpr, EP_xIsSelect) ){
sqlite3ExplainSelect(pOut, pExpr->x.pSelect);
}else{
sqlite3ExplainExprList(pOut, pExpr->x.pList);
}
sqlite3ExplainPrintf(pOut, ")");
break;
}
#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: {
Expr *pX = pExpr->pLeft;
Expr *pY = pExpr->x.pList->a[0].pExpr;
Expr *pZ = pExpr->x.pList->a[1].pExpr;
sqlite3ExplainPrintf(pOut, "BETWEEN(");
sqlite3ExplainExpr(pOut, pX);
sqlite3ExplainPrintf(pOut, ",");
sqlite3ExplainExpr(pOut, pY);
sqlite3ExplainPrintf(pOut, ",");
sqlite3ExplainExpr(pOut, pZ);
sqlite3ExplainPrintf(pOut, ")");
break;
}
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.
*/
sqlite3ExplainPrintf(pOut, "%s(%d)",
pExpr->iTable ? "NEW" : "OLD", pExpr->iColumn);
break;
}
case TK_CASE: {
sqlite3ExplainPrintf(pOut, "CASE(");
sqlite3ExplainExpr(pOut, pExpr->pLeft);
sqlite3ExplainPrintf(pOut, ",");
sqlite3ExplainExprList(pOut, pExpr->x.pList);
break;
}
#ifndef SQLITE_OMIT_TRIGGER
case TK_RAISE: {
const char *zType = "unk";
switch( pExpr->affinity ){
case OE_Rollback: zType = "rollback"; break;
case OE_Abort: zType = "abort"; break;
case OE_Fail: zType = "fail"; break;
case OE_Ignore: zType = "ignore"; break;
}
sqlite3ExplainPrintf(pOut, "RAISE-%s(%s)", zType, pExpr->u.zToken);
break;
}
#endif
}
if( zBinOp ){
sqlite3ExplainPrintf(pOut,"%s(", zBinOp);
sqlite3ExplainExpr(pOut, pExpr->pLeft);
sqlite3ExplainPrintf(pOut,",");
sqlite3ExplainExpr(pOut, pExpr->pRight);
sqlite3ExplainPrintf(pOut,")");
}else if( zUniOp ){
sqlite3ExplainPrintf(pOut,"%s(", zUniOp);
sqlite3ExplainExpr(pOut, pExpr->pLeft);
sqlite3ExplainPrintf(pOut,")");
}
}
#endif /* defined(SQLITE_ENABLE_TREE_EXPLAIN) */
#if defined(SQLITE_ENABLE_TREE_EXPLAIN)
/*
** Generate a human-readable explanation of an expression list.
*/
void sqlite3ExplainExprList(Vdbe *pOut, ExprList *pList){
int i;
if( pList==0 || pList->nExpr==0 ){
sqlite3ExplainPrintf(pOut, "(empty-list)");
return;
}else if( pList->nExpr==1 ){
sqlite3ExplainExpr(pOut, pList->a[0].pExpr);
}else{
sqlite3ExplainPush(pOut);
for(i=0; i<pList->nExpr; i++){
sqlite3ExplainPrintf(pOut, "item[%d] = ", i);
sqlite3ExplainPush(pOut);
sqlite3ExplainExpr(pOut, pList->a[i].pExpr);
sqlite3ExplainPop(pOut);
if( i<pList->nExpr-1 ){
sqlite3ExplainNL(pOut);
}
}
sqlite3ExplainPop(pOut);
}
}
#endif /* SQLITE_DEBUG */
/*
** Return TRUE if pExpr is an constant expression that is appropriate
** for factoring out of a loop. Appropriate expressions are:
**
** * Any expression that evaluates to two or more opcodes.
**
** * Any OP_Integer, OP_Real, OP_String, OP_Blob, OP_Null,
** or OP_Variable that does not need to be placed in a
** specific register.
**
** There is no point in factoring out single-instruction constant
** expressions that need to be placed in a particular register.
** We could factor them out, but then we would end up adding an
** OP_SCopy instruction to move the value into the correct register
** later. We might as well just use the original instruction and
** avoid the OP_SCopy.
*/
static int isAppropriateForFactoring(Expr *p){
if( !sqlite3ExprIsConstantNotJoin(p) ){
return 0; /* Only constant expressions are appropriate for factoring */
}
if( (p->flags & EP_FixedDest)==0 ){
return 1; /* Any constant without a fixed destination is appropriate */
}
while( p->op==TK_UPLUS ) p = p->pLeft;
switch( p->op ){
#ifndef SQLITE_OMIT_BLOB_LITERAL
case TK_BLOB:
#endif
case TK_VARIABLE:
case TK_INTEGER:
case TK_FLOAT:
case TK_NULL:
case TK_STRING: {
testcase( p->op==TK_BLOB );
testcase( p->op==TK_VARIABLE );
testcase( p->op==TK_INTEGER );
testcase( p->op==TK_FLOAT );
testcase( p->op==TK_NULL );
testcase( p->op==TK_STRING );
/* Single-instruction constants with a fixed destination are
** better done in-line. If we factor them, they will just end
** up generating an OP_SCopy to move the value to the destination
** register. */
return 0;
}
case TK_UMINUS: {
if( p->pLeft->op==TK_FLOAT || p->pLeft->op==TK_INTEGER ){
return 0;
}
break;
}
default: {
break;
}
}
return 1;
}
/*
** If pExpr is a constant expression that is appropriate for
** factoring out of a loop, then evaluate the expression
** into a register and convert the expression into a TK_REGISTER
** expression.
*/
static int evalConstExpr(Walker *pWalker, Expr *pExpr){
Parse *pParse = pWalker->pParse;
switch( pExpr->op ){
case TK_IN:
case TK_REGISTER: {
return WRC_Prune;
}
case TK_FUNCTION:
case TK_AGG_FUNCTION:
case TK_CONST_FUNC: {
/* The arguments to a function have a fixed destination.
** Mark them this way to avoid generated unneeded OP_SCopy
** instructions.
*/
ExprList *pList = pExpr->x.pList;
assert( !ExprHasProperty(pExpr, EP_xIsSelect) );
if( pList ){
int i = pList->nExpr;
struct ExprList_item *pItem = pList->a;
for(; i>0; i--, pItem++){
if( ALWAYS(pItem->pExpr) ) pItem->pExpr->flags |= EP_FixedDest;
}
}
break;
}
}
if( isAppropriateForFactoring(pExpr) ){
int r1 = ++pParse->nMem;
int r2;
r2 = sqlite3ExprCodeTarget(pParse, pExpr, r1);
if( NEVER(r1!=r2) ) sqlite3ReleaseTempReg(pParse, r1);
pExpr->op2 = pExpr->op;
pExpr->op = TK_REGISTER;
pExpr->iTable = r2;
return WRC_Prune;
}
return WRC_Continue;
}
/*
** Preevaluate constant subexpressions within pExpr and store the
** results in registers. Modify pExpr so that the constant subexpresions
** are TK_REGISTER opcodes that refer to the precomputed values.
**
** This routine is a no-op if the jump to the cookie-check code has
** already occur. Since the cookie-check jump is generated prior to
** any other serious processing, this check ensures that there is no
** way to accidently bypass the constant initializations.
**
** This routine is also a no-op if the SQLITE_FactorOutConst optimization
** is disabled via the sqlite3_test_control(SQLITE_TESTCTRL_OPTIMIZATIONS)
** interface. This allows test logic to verify that the same answer is
** obtained for queries regardless of whether or not constants are
** precomputed into registers or if they are inserted in-line.
*/
void sqlite3ExprCodeConstants(Parse *pParse, Expr *pExpr){
Walker w;
if( pParse->cookieGoto ) return;
if( (pParse->db->flags & SQLITE_FactorOutConst)!=0 ) return;
w.xExprCallback = evalConstExpr;
w.xSelectCallback = 0;
w.pParse = pParse;
sqlite3WalkExpr(&w, pExpr);
}
/*
** 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.
*/
int sqlite3ExprCodeExprList(
Parse *pParse, /* Parsing context */
ExprList *pList, /* The expression list to be coded */
int target, /* Where to write results */
int doHardCopy /* Make a hard copy of every element */
){
struct ExprList_item *pItem;
int i, n;
assert( pList!=0 );
assert( target>0 );
assert( pParse->pVdbe!=0 ); /* Never gets this far otherwise */
n = pList->nExpr;
for(pItem=pList->a, i=0; i<n; i++, pItem++){
Expr *pExpr = pItem->pExpr;
int inReg = sqlite3ExprCodeTarget(pParse, pExpr, target+i);
if( inReg!=target+i ){
sqlite3VdbeAddOp2(pParse->pVdbe, doHardCopy ? OP_Copy : OP_SCopy,
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
** elementation of x.
*/
static void exprCodeBetween(
Parse *pParse, /* Parsing and code generating context */
Expr *pExpr, /* The BETWEEN expression */
int dest, /* Jump here if the jump is taken */
int jumpIfTrue, /* Take the jump if the BETWEEN is true */
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 */
Expr exprX; /* The x subexpression */
int regFree1 = 0; /* Temporary use register */
assert( !ExprHasProperty(pExpr, EP_xIsSelect) );
exprX = *pExpr->pLeft;
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;
exprX.iTable = sqlite3ExprCodeTemp(pParse, &exprX, &regFree1);
exprX.op = TK_REGISTER;
if( jumpIfTrue ){
sqlite3ExprIfTrue(pParse, &exprAnd, dest, jumpIfNull);
}else{
sqlite3ExprIfFalse(pParse, &exprAnd, dest, jumpIfNull);
}
sqlite3ReleaseTempReg(pParse, regFree1);
/* Ensure adequate test coverage */
testcase( jumpIfTrue==0 && jumpIfNull==0 && regFree1==0 );
testcase( jumpIfTrue==0 && jumpIfNull==0 && regFree1!=0 );
testcase( jumpIfTrue==0 && jumpIfNull!=0 && regFree1==0 );
testcase( jumpIfTrue==0 && jumpIfNull!=0 && regFree1!=0 );
testcase( jumpIfTrue!=0 && jumpIfNull==0 && regFree1==0 );
testcase( jumpIfTrue!=0 && jumpIfNull==0 && regFree1!=0 );
testcase( jumpIfTrue!=0 && jumpIfNull!=0 && regFree1==0 );
testcase( jumpIfTrue!=0 && jumpIfNull!=0 && regFree1!=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; /* Existance 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 );
sqlite3ExprCachePush(pParse);
sqlite3ExprIfFalse(pParse, pExpr->pLeft, d2,jumpIfNull^SQLITE_JUMPIFNULL);
sqlite3ExprIfTrue(pParse, pExpr->pRight, dest, jumpIfNull);
sqlite3VdbeResolveLabel(v, d2);
sqlite3ExprCachePop(pParse, 1);
break;
}
case TK_OR: {
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_LT:
case TK_LE:
case TK_GT:
case TK_GE:
case TK_NE:
case TK_EQ: {
assert( TK_LT==OP_Lt );
assert( TK_LE==OP_Le );
assert( TK_GT==OP_Gt );
assert( TK_GE==OP_Ge );
assert( TK_EQ==OP_Eq );
assert( TK_NE==OP_Ne );
testcase( op==TK_LT );
testcase( op==TK_LE );
testcase( op==TK_GT );
testcase( op==TK_GE );
testcase( op==TK_EQ );
testcase( op==TK_NE );
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);
testcase( regFree1==0 );
testcase( regFree2==0 );
break;
}
case TK_IS:
case TK_ISNOT: {
testcase( op==TK_IS );
testcase( op==TK_ISNOT );
r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, &regFree1);
r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, &regFree2);
op = (op==TK_IS) ? TK_EQ : TK_NE;
codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op,
r1, r2, dest, SQLITE_NULLEQ);
testcase( regFree1==0 );
testcase( regFree2==0 );
break;
}
case TK_ISNULL:
case TK_NOTNULL: {
assert( TK_ISNULL==OP_IsNull );
assert( TK_NOTNULL==OP_NotNull );
testcase( op==TK_ISNULL );
testcase( op==TK_NOTNULL );
r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, &regFree1);
sqlite3VdbeAddOp2(v, op, r1, dest);
testcase( regFree1==0 );
break;
}
case TK_BETWEEN: {
testcase( jumpIfNull==0 );
exprCodeBetween(pParse, pExpr, dest, 1, jumpIfNull);
break;
}
#ifndef SQLITE_OMIT_SUBQUERY
case TK_IN: {
int destIfFalse = sqlite3VdbeMakeLabel(v);
int destIfNull = jumpIfNull ? dest : destIfFalse;
sqlite3ExprCodeIN(pParse, pExpr, destIfFalse, destIfNull);
sqlite3VdbeAddOp2(v, OP_Goto, 0, dest);
sqlite3VdbeResolveLabel(v, destIfFalse);
break;
}
#endif
default: {
r1 = sqlite3ExprCodeTemp(pParse, pExpr, &regFree1);
sqlite3VdbeAddOp3(v, OP_If, r1, dest, jumpIfNull!=0);
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; /* Existance 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);
sqlite3ExprIfFalse(pParse, pExpr->pRight, dest, jumpIfNull);
break;
}
case TK_OR: {
int d2 = sqlite3VdbeMakeLabel(v);
testcase( jumpIfNull==0 );
sqlite3ExprCachePush(pParse);
sqlite3ExprIfTrue(pParse, pExpr->pLeft, d2, jumpIfNull^SQLITE_JUMPIFNULL);
sqlite3ExprIfFalse(pParse, pExpr->pRight, dest, jumpIfNull);
sqlite3VdbeResolveLabel(v, d2);
sqlite3ExprCachePop(pParse, 1);
break;
}
case TK_NOT: {
testcase( jumpIfNull==0 );
sqlite3ExprIfTrue(pParse, pExpr->pLeft, dest, jumpIfNull);
break;
}
case TK_LT:
case TK_LE:
case TK_GT:
case TK_GE:
case TK_NE:
case TK_EQ: {
testcase( op==TK_LT );
testcase( op==TK_LE );
testcase( op==TK_GT );
testcase( op==TK_GE );
testcase( op==TK_EQ );
testcase( op==TK_NE );
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);
testcase( regFree1==0 );
testcase( regFree2==0 );
break;
}
case TK_IS:
case TK_ISNOT: {
testcase( pExpr->op==TK_IS );
testcase( pExpr->op==TK_ISNOT );
r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, &regFree1);
r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, &regFree2);
op = (pExpr->op==TK_IS) ? TK_NE : TK_EQ;
codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op,
r1, r2, dest, SQLITE_NULLEQ);
testcase( regFree1==0 );
testcase( regFree2==0 );
break;
}
case TK_ISNULL:
case TK_NOTNULL: {
testcase( op==TK_ISNULL );
testcase( op==TK_NOTNULL );
r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, &regFree1);
sqlite3VdbeAddOp2(v, op, r1, dest);
testcase( regFree1==0 );
break;
}
case TK_BETWEEN: {
testcase( jumpIfNull==0 );
exprCodeBetween(pParse, pExpr, dest, 0, 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: {
r1 = sqlite3ExprCodeTemp(pParse, pExpr, &regFree1);
sqlite3VdbeAddOp3(v, OP_IfNot, r1, dest, jumpIfNull!=0);
testcase( regFree1==0 );
testcase( jumpIfNull==0 );
break;
}
}
sqlite3ReleaseTempReg(pParse, regFree1);
sqlite3ReleaseTempReg(pParse, regFree2);
}
/*
** 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.
**
** 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.
*/
int sqlite3ExprCompare(Expr *pA, Expr *pB){
if( pA==0||pB==0 ){
return pB==pA ? 0 : 2;
}
assert( !ExprHasAnyProperty(pA, EP_TokenOnly|EP_Reduced) );
assert( !ExprHasAnyProperty(pB, EP_TokenOnly|EP_Reduced) );
if( ExprHasProperty(pA, EP_xIsSelect) || ExprHasProperty(pB, EP_xIsSelect) ){
return 2;
}
if( (pA->flags & EP_Distinct)!=(pB->flags & EP_Distinct) ) return 2;
if( pA->op!=pB->op ) return 2;
if( sqlite3ExprCompare(pA->pLeft, pB->pLeft) ) return 2;
if( sqlite3ExprCompare(pA->pRight, pB->pRight) ) return 2;
if( sqlite3ExprListCompare(pA->x.pList, pB->x.pList) ) return 2;
if( pA->iTable!=pB->iTable || pA->iColumn!=pB->iColumn ) return 2;
if( ExprHasProperty(pA, EP_IntValue) ){
if( !ExprHasProperty(pB, EP_IntValue) || pA->u.iValue!=pB->u.iValue ){
return 2;
}
}else if( pA->op!=TK_COLUMN && ALWAYS(pA->op!=TK_AGG_COLUMN) && pA->u.zToken){
if( ExprHasProperty(pB, EP_IntValue) || NEVER(pB->u.zToken==0) ) return 2;
if( strcmp(pA->u.zToken,pB->u.zToken)!=0 ){
return 2;
}
}
if( (pA->flags & EP_ExpCollate)!=(pB->flags & EP_ExpCollate) ) return 1;
if( (pA->flags & EP_ExpCollate)!=0 && pA->pColl!=pB->pColl ) return 2;
return 0;
}
/*
** Compare two ExprList objects. Return 0 if they are identical and
** non-zero if they differ in any way.
**
** 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 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++){
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(pExprA, pExprB) ) return 1;
}
return 0;
}
/*
** This is the expression callback for sqlite3FunctionUsesOtherSrc().
**
** Determine if an expression references any table other than one of the
** tables in pWalker->u.pSrcList and abort if it does.
*/
static int exprUsesOtherSrc(Walker *pWalker, Expr *pExpr){
if( pExpr->op==TK_COLUMN || pExpr->op==TK_AGG_COLUMN ){
int i;
SrcList *pSrc = pWalker->u.pSrcList;
for(i=0; i<pSrc->nSrc; i++){
if( pExpr->iTable==pSrc->a[i].iCursor ) return WRC_Continue;
}
return WRC_Abort;
}else{
return WRC_Continue;
}
}
/*
** Determine if any of the arguments to the pExpr Function references
** any SrcList other than pSrcList. Return true if they do. Return
** false if pExpr has no argument or has only constant arguments or
** only references tables named in pSrcList.
*/
static int sqlite3FunctionUsesOtherSrc(Expr *pExpr, SrcList *pSrcList){
Walker w;
assert( pExpr->op==TK_AGG_FUNCTION );
memset(&w, 0, sizeof(w));
w.xExprCallback = exprUsesOtherSrc;
w.u.pSrcList = pSrcList;
if( sqlite3WalkExprList(&w, pExpr->x.pList)!=WRC_Continue ) return 1;
return 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; i<pSrcList->nSrc; i++, pItem++){
struct AggInfo_col *pCol;
assert( !ExprHasAnyProperty(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; k<pAggInfo->nColumn; 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; 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++;
}
}
/* 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.
*/
ExprSetIrreducible(pExpr);
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
&& !sqlite3FunctionUsesOtherSrc(pExpr, pSrcList)
){
/* 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( sqlite3ExprCompare(pItem->pExpr, pExpr)==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, sqlite3Strlen30(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