/*
** 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.
**
** $Id: expr.c,v 1.303 2007/08/07 17:13:04 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.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 ){
return sqlite3ExprAffinity(pExpr->pSelect->pEList->a[0].pExpr);
}
#ifndef SQLITE_OMIT_CAST
if( op==TK_CAST ){
return sqlite3AffinityType(&pExpr->token);
}
#endif
return pExpr->affinity;
}
/*
** 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 *sqlite3ExprSetColl(Parse *pParse, Expr *pExpr, Token *pName){
CollSeq *pColl;
if( pExpr==0 ) return 0;
pColl = sqlite3LocateCollSeq(pParse, (char*)pName->z, pName->n);
if( pColl ){
pExpr->pColl = pColl;
pExpr->flags |= EP_ExpCollate;
}
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;
if( pExpr ){
int op;
pColl = pExpr->pColl;
op = pExpr->op;
if( (op==TK_CAST || op==TK_UPLUS) && !pColl ){
return sqlite3ExprCollSeq(pParse, pExpr->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 );
assert( pExpr->pLeft );
aff = sqlite3ExprAffinity(pExpr->pLeft);
if( pExpr->pRight ){
aff = sqlite3CompareAffinity(pExpr->pRight, aff);
}
else if( pExpr->pSelect ){
aff = sqlite3CompareAffinity(pExpr->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 P1 value that should be used for a binary comparison
** opcode (OP_Eq, OP_Ge etc.) used to compare pExpr1 and pExpr2.
** If jumpIfNull is true, then set the low byte of the returned
** P1 value to tell the opcode to jump if either expression
** evaluates to NULL.
*/
static int binaryCompareP1(Expr *pExpr1, Expr *pExpr2, int jumpIfNull){
char aff = sqlite3ExprAffinity(pExpr2);
return ((int)sqlite3CompareAffinity(pExpr1, aff))+(jumpIfNull?0x100:0);
}
/*
** 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 dest, /* Jump here if true. */
int jumpIfNull /* If true, jump if either operand is NULL */
){
int p1 = binaryCompareP1(pLeft, pRight, jumpIfNull);
CollSeq *p3 = sqlite3BinaryCompareCollSeq(pParse, pLeft, pRight);
return sqlite3VdbeOp3(pParse->pVdbe, opcode, p1, dest, (void*)p3, P3_COLLSEQ);
}
/*
** Construct a new expression node and return a pointer to it. Memory
** for this node is obtained from sqliteMalloc(). The calling function
** is responsible for making sure the node eventually gets freed.
*/
Expr *sqlite3Expr(int op, Expr *pLeft, Expr *pRight, const Token *pToken){
Expr *pNew;
pNew = sqliteMalloc( sizeof(Expr) );
if( pNew==0 ){
/* When malloc fails, delete pLeft and pRight. Expressions passed to
** this function must always be allocated with sqlite3Expr() for this
** reason.
*/
sqlite3ExprDelete(pLeft);
sqlite3ExprDelete(pRight);
return 0;
}
pNew->op = op;
pNew->pLeft = pLeft;
pNew->pRight = pRight;
pNew->iAgg = -1;
if( pToken ){
assert( pToken->dyn==0 );
pNew->span = pNew->token = *pToken;
}else if( pLeft ){
if( pRight ){
sqlite3ExprSpan(pNew, &pLeft->span, &pRight->span);
if( pRight->flags & EP_ExpCollate ){
pNew->flags |= EP_ExpCollate;
pNew->pColl = pRight->pColl;
}
}
if( pLeft->flags & EP_ExpCollate ){
pNew->flags |= EP_ExpCollate;
pNew->pColl = pLeft->pColl;
}
}
sqlite3ExprSetHeight(pNew);
return pNew;
}
/*
** Works like sqlite3Expr() but frees its pLeft and pRight arguments
** if it fails due to a malloc problem.
*/
Expr *sqlite3ExprOrFree(int op, Expr *pLeft, Expr *pRight, const Token *pToken){
Expr *pNew = sqlite3Expr(op, pLeft, pRight, pToken);
if( pNew==0 ){
sqlite3ExprDelete(pLeft);
sqlite3ExprDelete(pRight);
}
return pNew;
}
/*
** When doing a nested parse, you can include terms in an expression
** that look like this: #0 #1 #2 ... These terms refer to elements
** on the stack. "#0" means the top of the stack.
** "#1" means the next down on the stack. And so forth.
**
** This routine is called by the parser to deal with on of those terms.
** It immediately generates code to store the value in a memory location.
** The returns an expression that will code to extract the value from
** that memory location as needed.
*/
Expr *sqlite3RegisterExpr(Parse *pParse, Token *pToken){
Vdbe *v = pParse->pVdbe;
Expr *p;
int depth;
if( pParse->nested==0 ){
sqlite3ErrorMsg(pParse, "near \"%T\": syntax error", pToken);
return sqlite3Expr(TK_NULL, 0, 0, 0);
}
if( v==0 ) return 0;
p = sqlite3Expr(TK_REGISTER, 0, 0, pToken);
if( p==0 ){
return 0; /* Malloc failed */
}
depth = atoi((char*)&pToken->z[1]);
p->iTable = pParse->nMem++;
sqlite3VdbeAddOp(v, OP_Dup, depth, 0);
sqlite3VdbeAddOp(v, OP_MemStore, p->iTable, 1);
return p;
}
/*
** Join two expressions using an AND operator. If either expression is
** NULL, then just return the other expression.
*/
Expr *sqlite3ExprAnd(Expr *pLeft, Expr *pRight){
if( pLeft==0 ){
return pRight;
}else if( pRight==0 ){
return pLeft;
}else{
return sqlite3Expr(TK_AND, pLeft, pRight, 0);
}
}
/*
** Set the Expr.span field of the given expression to span all
** text between the two given tokens.
*/
void sqlite3ExprSpan(Expr *pExpr, Token *pLeft, Token *pRight){
assert( pRight!=0 );
assert( pLeft!=0 );
if( !sqlite3MallocFailed() && pRight->z && pLeft->z ){
assert( pLeft->dyn==0 || pLeft->z[pLeft->n]==0 );
if( pLeft->dyn==0 && pRight->dyn==0 ){
pExpr->span.z = pLeft->z;
pExpr->span.n = pRight->n + (pRight->z - pLeft->z);
}else{
pExpr->span.z = 0;
}
}
}
/*
** Construct a new expression node for a function with multiple
** arguments.
*/
Expr *sqlite3ExprFunction(ExprList *pList, Token *pToken){
Expr *pNew;
assert( pToken );
pNew = sqliteMalloc( sizeof(Expr) );
if( pNew==0 ){
sqlite3ExprListDelete(pList); /* Avoid leaking memory when malloc fails */
return 0;
}
pNew->op = TK_FUNCTION;
pNew->pList = pList;
assert( pToken->dyn==0 );
pNew->token = *pToken;
pNew->span = pNew->token;
sqlite3ExprSetHeight(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" or "$aaa" are assigned the same number
** as the previous instance of the same wildcard. Or if this is the first
** instance of the wildcard, the next sequenial variable number is
** assigned.
*/
void sqlite3ExprAssignVarNumber(Parse *pParse, Expr *pExpr){
Token *pToken;
if( pExpr==0 ) return;
pToken = &pExpr->token;
assert( pToken->n>=1 );
assert( pToken->z!=0 );
assert( pToken->z[0]!=0 );
if( pToken->n==1 ){
/* Wildcard of the form "?". Assign the next variable number */
pExpr->iTable = ++pParse->nVar;
}else if( pToken->z[0]=='?' ){
/* Wildcard of the form "?nnn". Convert "nnn" to an integer and
** use it as the variable number */
int i;
pExpr->iTable = i = atoi((char*)&pToken->z[1]);
if( i<1 || i>SQLITE_MAX_VARIABLE_NUMBER ){
sqlite3ErrorMsg(pParse, "variable number must be between ?1 and ?%d",
SQLITE_MAX_VARIABLE_NUMBER);
}
if( i>pParse->nVar ){
pParse->nVar = i;
}
}else{
/* Wildcards of the form ":aaa" or "$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
*/
int i, n;
n = pToken->n;
for(i=0; i<pParse->nVarExpr; i++){
Expr *pE;
if( (pE = pParse->apVarExpr[i])!=0
&& pE->token.n==n
&& memcmp(pE->token.z, pToken->z, n)==0 ){
pExpr->iTable = pE->iTable;
break;
}
}
if( i>=pParse->nVarExpr ){
pExpr->iTable = ++pParse->nVar;
if( pParse->nVarExpr>=pParse->nVarExprAlloc-1 ){
pParse->nVarExprAlloc += pParse->nVarExprAlloc + 10;
pParse->apVarExpr = sqliteReallocOrFree(pParse->apVarExpr,
pParse->nVarExprAlloc*sizeof(pParse->apVarExpr[0]) );
}
if( !sqlite3MallocFailed() ){
assert( pParse->apVarExpr!=0 );
pParse->apVarExpr[pParse->nVarExpr++] = pExpr;
}
}
}
if( !pParse->nErr && pParse->nVar>SQLITE_MAX_VARIABLE_NUMBER ){
sqlite3ErrorMsg(pParse, "too many SQL variables");
}
}
/*
** Recursively delete an expression tree.
*/
void sqlite3ExprDelete(Expr *p){
if( p==0 ) return;
if( p->span.dyn ) sqliteFree((char*)p->span.z);
if( p->token.dyn ) sqliteFree((char*)p->token.z);
sqlite3ExprDelete(p->pLeft);
sqlite3ExprDelete(p->pRight);
sqlite3ExprListDelete(p->pList);
sqlite3SelectDelete(p->pSelect);
sqliteFree(p);
}
/*
** The Expr.token field might be a string literal that is quoted.
** If so, remove the quotation marks.
*/
void sqlite3DequoteExpr(Expr *p){
if( ExprHasAnyProperty(p, EP_Dequoted) ){
return;
}
ExprSetProperty(p, EP_Dequoted);
if( p->token.dyn==0 ){
sqlite3TokenCopy(&p->token, &p->token);
}
sqlite3Dequote((char*)p->token.z);
}
/*
** 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.
*/
Expr *sqlite3ExprDup(Expr *p){
Expr *pNew;
if( p==0 ) return 0;
pNew = sqliteMallocRaw( sizeof(*p) );
if( pNew==0 ) return 0;
memcpy(pNew, p, sizeof(*pNew));
if( p->token.z!=0 ){
pNew->token.z = (u8*)sqliteStrNDup((char*)p->token.z, p->token.n);
pNew->token.dyn = 1;
}else{
assert( pNew->token.z==0 );
}
pNew->span.z = 0;
pNew->pLeft = sqlite3ExprDup(p->pLeft);
pNew->pRight = sqlite3ExprDup(p->pRight);
pNew->pList = sqlite3ExprListDup(p->pList);
pNew->pSelect = sqlite3SelectDup(p->pSelect);
return pNew;
}
void sqlite3TokenCopy(Token *pTo, Token *pFrom){
if( pTo->dyn ) sqliteFree((char*)pTo->z);
if( pFrom->z ){
pTo->n = pFrom->n;
pTo->z = (u8*)sqliteStrNDup((char*)pFrom->z, pFrom->n);
pTo->dyn = 1;
}else{
pTo->z = 0;
}
}
ExprList *sqlite3ExprListDup(ExprList *p){
ExprList *pNew;
struct ExprList_item *pItem, *pOldItem;
int i;
if( p==0 ) return 0;
pNew = sqliteMalloc( sizeof(*pNew) );
if( pNew==0 ) return 0;
pNew->nExpr = pNew->nAlloc = p->nExpr;
pNew->a = pItem = sqliteMalloc( p->nExpr*sizeof(p->a[0]) );
if( pItem==0 ){
sqliteFree(pNew);
return 0;
}
pOldItem = p->a;
for(i=0; i<p->nExpr; i++, pItem++, pOldItem++){
Expr *pNewExpr, *pOldExpr;
pItem->pExpr = pNewExpr = sqlite3ExprDup(pOldExpr = pOldItem->pExpr);
if( pOldExpr->span.z!=0 && pNewExpr ){
/* Always make a copy of the span for top-level expressions in the
** expression list. The logic in SELECT processing that determines
** the names of columns in the result set needs this information */
sqlite3TokenCopy(&pNewExpr->span, &pOldExpr->span);
}
assert( pNewExpr==0 || pNewExpr->span.z!=0
|| pOldExpr->span.z==0
|| sqlite3MallocFailed() );
pItem->zName = sqliteStrDup(pOldItem->zName);
pItem->sortOrder = pOldItem->sortOrder;
pItem->isAgg = pOldItem->isAgg;
pItem->done = 0;
}
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(SrcList *p){
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 = sqliteMallocRaw( 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 = sqliteStrDup(pOldItem->zDatabase);
pNewItem->zName = sqliteStrDup(pOldItem->zName);
pNewItem->zAlias = sqliteStrDup(pOldItem->zAlias);
pNewItem->jointype = pOldItem->jointype;
pNewItem->iCursor = pOldItem->iCursor;
pNewItem->isPopulated = pOldItem->isPopulated;
pTab = pNewItem->pTab = pOldItem->pTab;
if( pTab ){
pTab->nRef++;
}
pNewItem->pSelect = sqlite3SelectDup(pOldItem->pSelect);
pNewItem->pOn = sqlite3ExprDup(pOldItem->pOn);
pNewItem->pUsing = sqlite3IdListDup(pOldItem->pUsing);
pNewItem->colUsed = pOldItem->colUsed;
}
return pNew;
}
IdList *sqlite3IdListDup(IdList *p){
IdList *pNew;
int i;
if( p==0 ) return 0;
pNew = sqliteMallocRaw( sizeof(*pNew) );
if( pNew==0 ) return 0;
pNew->nId = pNew->nAlloc = p->nId;
pNew->a = sqliteMallocRaw( p->nId*sizeof(p->a[0]) );
if( pNew->a==0 ){
sqliteFree(pNew);
return 0;
}
for(i=0; i<p->nId; i++){
struct IdList_item *pNewItem = &pNew->a[i];
struct IdList_item *pOldItem = &p->a[i];
pNewItem->zName = sqliteStrDup(pOldItem->zName);
pNewItem->idx = pOldItem->idx;
}
return pNew;
}
Select *sqlite3SelectDup(Select *p){
Select *pNew;
if( p==0 ) return 0;
pNew = sqliteMallocRaw( sizeof(*p) );
if( pNew==0 ) return 0;
pNew->isDistinct = p->isDistinct;
pNew->pEList = sqlite3ExprListDup(p->pEList);
pNew->pSrc = sqlite3SrcListDup(p->pSrc);
pNew->pWhere = sqlite3ExprDup(p->pWhere);
pNew->pGroupBy = sqlite3ExprListDup(p->pGroupBy);
pNew->pHaving = sqlite3ExprDup(p->pHaving);
pNew->pOrderBy = sqlite3ExprListDup(p->pOrderBy);
pNew->op = p->op;
pNew->pPrior = sqlite3SelectDup(p->pPrior);
pNew->pLimit = sqlite3ExprDup(p->pLimit);
pNew->pOffset = sqlite3ExprDup(p->pOffset);
pNew->iLimit = -1;
pNew->iOffset = -1;
pNew->isResolved = p->isResolved;
pNew->isAgg = p->isAgg;
pNew->usesEphm = 0;
pNew->disallowOrderBy = 0;
pNew->pRightmost = 0;
pNew->addrOpenEphm[0] = -1;
pNew->addrOpenEphm[1] = -1;
pNew->addrOpenEphm[2] = -1;
return pNew;
}
#else
Select *sqlite3SelectDup(Select *p){
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.
*/
ExprList *sqlite3ExprListAppend(ExprList *pList, Expr *pExpr, Token *pName){
if( pList==0 ){
pList = sqliteMalloc( sizeof(ExprList) );
if( pList==0 ){
goto no_mem;
}
assert( pList->nAlloc==0 );
}
if( pList->nAlloc<=pList->nExpr ){
struct ExprList_item *a;
int n = pList->nAlloc*2 + 4;
a = sqliteRealloc(pList->a, n*sizeof(pList->a[0]));
if( a==0 ){
goto no_mem;
}
pList->a = a;
pList->nAlloc = n;
}
assert( pList->a!=0 );
if( pExpr || pName ){
struct ExprList_item *pItem = &pList->a[pList->nExpr++];
memset(pItem, 0, sizeof(*pItem));
pItem->zName = sqlite3NameFromToken(pName);
pItem->pExpr = pExpr;
}
return pList;
no_mem:
/* Avoid leaking memory if malloc has failed. */
sqlite3ExprDelete(pExpr);
sqlite3ExprListDelete(pList);
return 0;
}
/*
** If the expression list pEList contains more than iLimit elements,
** leave an error message in pParse.
*/
void sqlite3ExprListCheckLength(
Parse *pParse,
ExprList *pEList,
int iLimit,
const char *zObject
){
if( pEList && pEList->nExpr>iLimit ){
sqlite3ErrorMsg(pParse, "too many columns in %s", zObject);
}
}
#if SQLITE_MAX_EXPR_DEPTH>0
/* 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.
*/
void sqlite3ExprSetHeight(Expr *p){
int nHeight = 0;
heightOfExpr(p->pLeft, &nHeight);
heightOfExpr(p->pRight, &nHeight);
heightOfExprList(p->pList, &nHeight);
heightOfSelect(p->pSelect, &nHeight);
p->nHeight = nHeight + 1;
}
/*
** 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;
}
#endif
/*
** Delete an entire expression list.
*/
void sqlite3ExprListDelete(ExprList *pList){
int i;
struct ExprList_item *pItem;
if( pList==0 ) return;
assert( pList->a!=0 || (pList->nExpr==0 && pList->nAlloc==0) );
assert( pList->nExpr<=pList->nAlloc );
for(pItem=pList->a, i=0; i<pList->nExpr; i++, pItem++){
sqlite3ExprDelete(pItem->pExpr);
sqliteFree(pItem->zName);
}
sqliteFree(pList->a);
sqliteFree(pList);
}
/*
** Walk an expression tree. Call xFunc for each node visited.
**
** The return value from xFunc determines whether the tree walk continues.
** 0 means continue walking the tree. 1 means do not walk children
** of the current node but continue with siblings. 2 means abandon
** the tree walk completely.
**
** The return value from this routine is 1 to abandon the tree walk
** and 0 to continue.
**
** NOTICE: This routine does *not* descend into subqueries.
*/
static int walkExprList(ExprList *, int (*)(void *, Expr*), void *);
static int walkExprTree(Expr *pExpr, int (*xFunc)(void*,Expr*), void *pArg){
int rc;
if( pExpr==0 ) return 0;
rc = (*xFunc)(pArg, pExpr);
if( rc==0 ){
if( walkExprTree(pExpr->pLeft, xFunc, pArg) ) return 1;
if( walkExprTree(pExpr->pRight, xFunc, pArg) ) return 1;
if( walkExprList(pExpr->pList, xFunc, pArg) ) return 1;
}
return rc>1;
}
/*
** Call walkExprTree() for every expression in list p.
*/
static int walkExprList(ExprList *p, int (*xFunc)(void *, Expr*), void *pArg){
int i;
struct ExprList_item *pItem;
if( !p ) return 0;
for(i=p->nExpr, pItem=p->a; i>0; i--, pItem++){
if( walkExprTree(pItem->pExpr, xFunc, pArg) ) return 1;
}
return 0;
}
/*
** Call walkExprTree() for every expression in Select p, not including
** expressions that are part of sub-selects in any FROM clause or the LIMIT
** or OFFSET expressions..
*/
static int walkSelectExpr(Select *p, int (*xFunc)(void *, Expr*), void *pArg){
walkExprList(p->pEList, xFunc, pArg);
walkExprTree(p->pWhere, xFunc, pArg);
walkExprList(p->pGroupBy, xFunc, pArg);
walkExprTree(p->pHaving, xFunc, pArg);
walkExprList(p->pOrderBy, xFunc, pArg);
if( p->pPrior ){
walkSelectExpr(p->pPrior, xFunc, pArg);
}
return 0;
}
/*
** This routine is designed as an xFunc for walkExprTree().
**
** pArg is really a pointer to an integer. If we can tell by looking
** at pExpr that the expression that contains pExpr is not a constant
** expression, then set *pArg to 0 and return 2 to abandon the tree walk.
** If pExpr does does not disqualify the expression from being a constant
** then do nothing.
**
** After walking the whole tree, if no nodes are found that disqualify
** the expression as constant, then we assume the whole expression
** is constant. See sqlite3ExprIsConstant() for additional information.
*/
static int exprNodeIsConstant(void *pArg, Expr *pExpr){
int *pN = (int*)pArg;
/* If *pArg 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( (*pN)==3 && ExprHasAnyProperty(pExpr, EP_FromJoin) ){
*pN = 0;
return 2;
}
switch( pExpr->op ){
/* Consider functions to be constant if all their arguments are constant
** and *pArg==2 */
case TK_FUNCTION:
if( (*pN)==2 ) return 0;
/* Fall through */
case TK_ID:
case TK_COLUMN:
case TK_DOT:
case TK_AGG_FUNCTION:
case TK_AGG_COLUMN:
#ifndef SQLITE_OMIT_SUBQUERY
case TK_SELECT:
case TK_EXISTS:
#endif
*pN = 0;
return 2;
case TK_IN:
if( pExpr->pSelect ){
*pN = 0;
return 2;
}
default:
return 0;
}
}
/*
** 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){
int isConst = 1;
walkExprTree(p, exprNodeIsConstant, &isConst);
return isConst;
}
/*
** 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){
int isConst = 3;
walkExprTree(p, exprNodeIsConstant, &isConst);
return isConst!=0;
}
/*
** 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){
int isConst = 2;
walkExprTree(p, exprNodeIsConstant, &isConst);
return isConst!=0;
}
/*
** 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){
switch( p->op ){
case TK_INTEGER: {
if( sqlite3GetInt32((char*)p->token.z, pValue) ){
return 1;
}
break;
}
case TK_UPLUS: {
return sqlite3ExprIsInteger(p->pLeft, pValue);
}
case TK_UMINUS: {
int v;
if( sqlite3ExprIsInteger(p->pLeft, &v) ){
*pValue = -v;
return 1;
}
break;
}
default: break;
}
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;
}
/*
** Given the name of a column of the form X.Y.Z or Y.Z or just Z, look up
** that name in the set of source tables in pSrcList and make the pExpr
** expression node refer back to that source column. The following changes
** are made to pExpr:
**
** pExpr->iDb Set the index in db->aDb[] of the database holding
** the table.
** pExpr->iTable Set to the cursor number for the table obtained
** from pSrcList.
** pExpr->iColumn Set to the column number within the table.
** pExpr->op Set to TK_COLUMN.
** pExpr->pLeft Any expression this points to is deleted
** pExpr->pRight Any expression this points to is deleted.
**
** The pDbToken is the name of the database (the "X"). This value may be
** NULL meaning that name is of the form Y.Z or Z. Any available database
** can be used. The pTableToken is the name of the table (the "Y"). This
** value can be NULL if pDbToken is also NULL. If pTableToken is NULL it
** means that the form of the name is Z and that columns from any table
** can be used.
**
** If the name cannot be resolved unambiguously, leave an error message
** in pParse and return non-zero. Return zero on success.
*/
static int lookupName(
Parse *pParse, /* The parsing context */
Token *pDbToken, /* Name of the database containing table, or NULL */
Token *pTableToken, /* Name of table containing column, or NULL */
Token *pColumnToken, /* Name of the column. */
NameContext *pNC, /* The name context used to resolve the name */
Expr *pExpr /* Make this EXPR node point to the selected column */
){
char *zDb = 0; /* Name of the database. The "X" in X.Y.Z */
char *zTab = 0; /* Name of the table. The "Y" in X.Y.Z or Y.Z */
char *zCol = 0; /* Name of the column. The "Z" */
int i, j; /* Loop counters */
int cnt = 0; /* Number of matching column names */
int cntTab = 0; /* Number of matching table names */
sqlite3 *db = pParse->db; /* The database */
struct SrcList_item *pItem; /* Use for looping over pSrcList items */
struct SrcList_item *pMatch = 0; /* The matching pSrcList item */
NameContext *pTopNC = pNC; /* First namecontext in the list */
assert( pColumnToken && pColumnToken->z ); /* The Z in X.Y.Z cannot be NULL */
zDb = sqlite3NameFromToken(pDbToken);
zTab = sqlite3NameFromToken(pTableToken);
zCol = sqlite3NameFromToken(pColumnToken);
if( sqlite3MallocFailed() ){
goto lookupname_end;
}
pExpr->iTable = -1;
while( pNC && cnt==0 ){
ExprList *pEList;
SrcList *pSrcList = pNC->pSrcList;
if( pSrcList ){
for(i=0, pItem=pSrcList->a; i<pSrcList->nSrc; i++, pItem++){
Table *pTab;
int iDb;
Column *pCol;
pTab = pItem->pTab;
assert( pTab!=0 );
iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
assert( pTab->nCol>0 );
if( zTab ){
if( pItem->zAlias ){
char *zTabName = pItem->zAlias;
if( sqlite3StrICmp(zTabName, zTab)!=0 ) continue;
}else{
char *zTabName = pTab->zName;
if( zTabName==0 || sqlite3StrICmp(zTabName, zTab)!=0 ) continue;
if( zDb!=0 && sqlite3StrICmp(db->aDb[iDb].zName, zDb)!=0 ){
continue;
}
}
}
if( 0==(cntTab++) ){
pExpr->iTable = pItem->iCursor;
pExpr->pSchema = pTab->pSchema;
pMatch = pItem;
}
for(j=0, pCol=pTab->aCol; j<pTab->nCol; j++, pCol++){
if( sqlite3StrICmp(pCol->zName, zCol)==0 ){
const char *zColl = pTab->aCol[j].zColl;
IdList *pUsing;
cnt++;
pExpr->iTable = pItem->iCursor;
pMatch = pItem;
pExpr->pSchema = pTab->pSchema;
/* Substitute the rowid (column -1) for the INTEGER PRIMARY KEY */
pExpr->iColumn = j==pTab->iPKey ? -1 : j;
pExpr->affinity = pTab->aCol[j].affinity;
if( (pExpr->flags & EP_ExpCollate)==0 ){
pExpr->pColl = sqlite3FindCollSeq(db, ENC(db), zColl,-1, 0);
}
if( i<pSrcList->nSrc-1 ){
if( pItem[1].jointype & JT_NATURAL ){
/* If this match occurred in the left table of a natural join,
** then skip the right table to avoid a duplicate match */
pItem++;
i++;
}else if( (pUsing = pItem[1].pUsing)!=0 ){
/* If this match occurs on a column that is in the USING clause
** of a join, skip the search of the right table of the join
** to avoid a duplicate match there. */
int k;
for(k=0; k<pUsing->nId; k++){
if( sqlite3StrICmp(pUsing->a[k].zName, zCol)==0 ){
pItem++;
i++;
break;
}
}
}
}
break;
}
}
}
}
#ifndef SQLITE_OMIT_TRIGGER
/* If we have not already resolved the name, then maybe
** it is a new.* or old.* trigger argument reference
*/
if( zDb==0 && zTab!=0 && cnt==0 && pParse->trigStack!=0 ){
TriggerStack *pTriggerStack = pParse->trigStack;
Table *pTab = 0;
if( pTriggerStack->newIdx != -1 && sqlite3StrICmp("new", zTab) == 0 ){
pExpr->iTable = pTriggerStack->newIdx;
assert( pTriggerStack->pTab );
pTab = pTriggerStack->pTab;
}else if( pTriggerStack->oldIdx != -1 && sqlite3StrICmp("old", zTab)==0 ){
pExpr->iTable = pTriggerStack->oldIdx;
assert( pTriggerStack->pTab );
pTab = pTriggerStack->pTab;
}
if( pTab ){
int iCol;
Column *pCol = pTab->aCol;
pExpr->pSchema = pTab->pSchema;
cntTab++;
for(iCol=0; iCol < pTab->nCol; iCol++, pCol++) {
if( sqlite3StrICmp(pCol->zName, zCol)==0 ){
const char *zColl = pTab->aCol[iCol].zColl;
cnt++;
pExpr->iColumn = iCol==pTab->iPKey ? -1 : iCol;
pExpr->affinity = pTab->aCol[iCol].affinity;
if( (pExpr->flags & EP_ExpCollate)==0 ){
pExpr->pColl = sqlite3FindCollSeq(db, ENC(db), zColl,-1, 0);
}
pExpr->pTab = pTab;
break;
}
}
}
}
#endif /* !defined(SQLITE_OMIT_TRIGGER) */
/*
** Perhaps the name is a reference to the ROWID
*/
if( cnt==0 && cntTab==1 && sqlite3IsRowid(zCol) ){
cnt = 1;
pExpr->iColumn = -1;
pExpr->affinity = SQLITE_AFF_INTEGER;
}
/*
** If the input is of the form Z (not Y.Z or X.Y.Z) then the name Z
** might refer to an result-set alias. This happens, for example, when
** we are resolving names in the WHERE clause of the following command:
**
** SELECT a+b AS x FROM table WHERE x<10;
**
** In cases like this, replace pExpr with a copy of the expression that
** forms the result set entry ("a+b" in the example) and return immediately.
** Note that the expression in the result set should have already been
** resolved by the time the WHERE clause is resolved.
*/
if( cnt==0 && (pEList = pNC->pEList)!=0 && zTab==0 ){
for(j=0; j<pEList->nExpr; j++){
char *zAs = pEList->a[j].zName;
if( zAs!=0 && sqlite3StrICmp(zAs, zCol)==0 ){
Expr *pDup, *pOrig;
assert( pExpr->pLeft==0 && pExpr->pRight==0 );
assert( pExpr->pList==0 );
assert( pExpr->pSelect==0 );
pOrig = pEList->a[j].pExpr;
if( !pNC->allowAgg && ExprHasProperty(pOrig, EP_Agg) ){
sqlite3ErrorMsg(pParse, "misuse of aliased aggregate %s", zAs);
sqliteFree(zCol);
return 2;
}
pDup = sqlite3ExprDup(pOrig);
if( pExpr->flags & EP_ExpCollate ){
pDup->pColl = pExpr->pColl;
pDup->flags |= EP_ExpCollate;
}
if( pExpr->span.dyn ) sqliteFree((char*)pExpr->span.z);
if( pExpr->token.dyn ) sqliteFree((char*)pExpr->token.z);
memcpy(pExpr, pDup, sizeof(*pExpr));
sqliteFree(pDup);
cnt = 1;
pMatch = 0;
assert( zTab==0 && zDb==0 );
goto lookupname_end_2;
}
}
}
/* Advance to the next name context. The loop will exit when either
** we have a match (cnt>0) or when we run out of name contexts.
*/
if( cnt==0 ){
pNC = pNC->pNext;
}
}
/*
** If X and Y are NULL (in other words if only the column name Z is
** supplied) and the value of Z is enclosed in double-quotes, then
** Z is a string literal if it doesn't match any column names. In that
** case, we need to return right away and not make any changes to
** pExpr.
**
** Because no reference was made to outer contexts, the pNC->nRef
** fields are not changed in any context.
*/
if( cnt==0 && zTab==0 && pColumnToken->z[0]=='"' ){
sqliteFree(zCol);
return 0;
}
/*
** cnt==0 means there was not match. cnt>1 means there were two or
** more matches. Either way, we have an error.
*/
if( cnt!=1 ){
char *z = 0;
char *zErr;
zErr = cnt==0 ? "no such column: %s" : "ambiguous column name: %s";
if( zDb ){
sqlite3SetString(&z, zDb, ".", zTab, ".", zCol, (char*)0);
}else if( zTab ){
sqlite3SetString(&z, zTab, ".", zCol, (char*)0);
}else{
z = sqliteStrDup(zCol);
}
sqlite3ErrorMsg(pParse, zErr, z);
sqliteFree(z);
pTopNC->nErr++;
}
/* If a column from a table in pSrcList is referenced, then record
** this fact in the pSrcList.a[].colUsed bitmask. Column 0 causes
** bit 0 to be set. Column 1 sets bit 1. And so forth. If the
** column number is greater than the number of bits in the bitmask
** then set the high-order bit of the bitmask.
*/
if( pExpr->iColumn>=0 && pMatch!=0 ){
int n = pExpr->iColumn;
if( n>=sizeof(Bitmask)*8 ){
n = sizeof(Bitmask)*8-1;
}
assert( pMatch->iCursor==pExpr->iTable );
pMatch->colUsed |= ((Bitmask)1)<<n;
}
lookupname_end:
/* Clean up and return
*/
sqliteFree(zDb);
sqliteFree(zTab);
sqlite3ExprDelete(pExpr->pLeft);
pExpr->pLeft = 0;
sqlite3ExprDelete(pExpr->pRight);
pExpr->pRight = 0;
pExpr->op = TK_COLUMN;
lookupname_end_2:
sqliteFree(zCol);
if( cnt==1 ){
assert( pNC!=0 );
sqlite3AuthRead(pParse, pExpr, pNC->pSrcList);
if( pMatch && !pMatch->pSelect ){
pExpr->pTab = pMatch->pTab;
}
/* Increment the nRef value on all name contexts from TopNC up to
** the point where the name matched. */
for(;;){
assert( pTopNC!=0 );
pTopNC->nRef++;
if( pTopNC==pNC ) break;
pTopNC = pTopNC->pNext;
}
return 0;
} else {
return 1;
}
}
/*
** This routine is designed as an xFunc for walkExprTree().
**
** Resolve symbolic names into TK_COLUMN operators for the current
** node in the expression tree. Return 0 to continue the search down
** the tree or 2 to abort the tree walk.
**
** This routine also does error checking and name resolution for
** function names. The operator for aggregate functions is changed
** to TK_AGG_FUNCTION.
*/
static int nameResolverStep(void *pArg, Expr *pExpr){
NameContext *pNC = (NameContext*)pArg;
Parse *pParse;
if( pExpr==0 ) return 1;
assert( pNC!=0 );
pParse = pNC->pParse;
if( ExprHasAnyProperty(pExpr, EP_Resolved) ) return 1;
ExprSetProperty(pExpr, EP_Resolved);
#ifndef NDEBUG
if( pNC->pSrcList && pNC->pSrcList->nAlloc>0 ){
SrcList *pSrcList = pNC->pSrcList;
int i;
for(i=0; i<pNC->pSrcList->nSrc; i++){
assert( pSrcList->a[i].iCursor>=0 && pSrcList->a[i].iCursor<pParse->nTab);
}
}
#endif
switch( pExpr->op ){
/* Double-quoted strings (ex: "abc") are used as identifiers if
** possible. Otherwise they remain as strings. Single-quoted
** strings (ex: 'abc') are always string literals.
*/
case TK_STRING: {
if( pExpr->token.z[0]=='\'' ) break;
/* Fall thru into the TK_ID case if this is a double-quoted string */
}
/* A lone identifier is the name of a column.
*/
case TK_ID: {
lookupName(pParse, 0, 0, &pExpr->token, pNC, pExpr);
return 1;
}
/* A table name and column name: ID.ID
** Or a database, table and column: ID.ID.ID
*/
case TK_DOT: {
Token *pColumn;
Token *pTable;
Token *pDb;
Expr *pRight;
/* if( pSrcList==0 ) break; */
pRight = pExpr->pRight;
if( pRight->op==TK_ID ){
pDb = 0;
pTable = &pExpr->pLeft->token;
pColumn = &pRight->token;
}else{
assert( pRight->op==TK_DOT );
pDb = &pExpr->pLeft->token;
pTable = &pRight->pLeft->token;
pColumn = &pRight->pRight->token;
}
lookupName(pParse, pDb, pTable, pColumn, pNC, pExpr);
return 1;
}
/* Resolve function names
*/
case TK_CONST_FUNC:
case TK_FUNCTION: {
ExprList *pList = pExpr->pList; /* The argument list */
int n = pList ? pList->nExpr : 0; /* Number of arguments */
int no_such_func = 0; /* True if no such function exists */
int wrong_num_args = 0; /* True if wrong number of arguments */
int is_agg = 0; /* True if is an aggregate function */
int i;
int auth; /* Authorization to use the function */
int nId; /* Number of characters in function name */
const char *zId; /* The function name. */
FuncDef *pDef; /* Information about the function */
int enc = ENC(pParse->db); /* The database encoding */
zId = (char*)pExpr->token.z;
nId = pExpr->token.n;
pDef = sqlite3FindFunction(pParse->db, zId, nId, n, enc, 0);
if( pDef==0 ){
pDef = sqlite3FindFunction(pParse->db, zId, nId, -1, enc, 0);
if( pDef==0 ){
no_such_func = 1;
}else{
wrong_num_args = 1;
}
}else{
is_agg = pDef->xFunc==0;
}
#ifndef SQLITE_OMIT_AUTHORIZATION
if( pDef ){
auth = sqlite3AuthCheck(pParse, SQLITE_FUNCTION, 0, pDef->zName, 0);
if( auth!=SQLITE_OK ){
if( auth==SQLITE_DENY ){
sqlite3ErrorMsg(pParse, "not authorized to use function: %s",
pDef->zName);
pNC->nErr++;
}
pExpr->op = TK_NULL;
return 1;
}
}
#endif
if( is_agg && !pNC->allowAgg ){
sqlite3ErrorMsg(pParse, "misuse of aggregate function %.*s()", nId,zId);
pNC->nErr++;
is_agg = 0;
}else if( no_such_func ){
sqlite3ErrorMsg(pParse, "no such function: %.*s", nId, zId);
pNC->nErr++;
}else if( wrong_num_args ){
sqlite3ErrorMsg(pParse,"wrong number of arguments to function %.*s()",
nId, zId);
pNC->nErr++;
}
if( is_agg ){
pExpr->op = TK_AGG_FUNCTION;
pNC->hasAgg = 1;
}
if( is_agg ) pNC->allowAgg = 0;
for(i=0; pNC->nErr==0 && i<n; i++){
walkExprTree(pList->a[i].pExpr, nameResolverStep, pNC);
}
if( is_agg ) pNC->allowAgg = 1;
/* FIX ME: Compute pExpr->affinity based on the expected return
** type of the function
*/
return is_agg;
}
#ifndef SQLITE_OMIT_SUBQUERY
case TK_SELECT:
case TK_EXISTS:
#endif
case TK_IN: {
if( pExpr->pSelect ){
int nRef = pNC->nRef;
#ifndef SQLITE_OMIT_CHECK
if( pNC->isCheck ){
sqlite3ErrorMsg(pParse,"subqueries prohibited in CHECK constraints");
}
#endif
sqlite3SelectResolve(pParse, pExpr->pSelect, pNC);
assert( pNC->nRef>=nRef );
if( nRef!=pNC->nRef ){
ExprSetProperty(pExpr, EP_VarSelect);
}
}
break;
}
#ifndef SQLITE_OMIT_CHECK
case TK_VARIABLE: {
if( pNC->isCheck ){
sqlite3ErrorMsg(pParse,"parameters prohibited in CHECK constraints");
}
break;
}
#endif
}
return 0;
}
/*
** This routine walks an expression tree and resolves references to
** table columns. Nodes of the form ID.ID or ID resolve into an
** index to the table in the table list and a column offset. The
** Expr.opcode for such nodes is changed to TK_COLUMN. The Expr.iTable
** value is changed to the index of the referenced table in pTabList
** plus the "base" value. The base value will ultimately become the
** VDBE cursor number for a cursor that is pointing into the referenced
** table. The Expr.iColumn value is changed to the index of the column
** of the referenced table. The Expr.iColumn value for the special
** ROWID column is -1. Any INTEGER PRIMARY KEY column is tried as an
** alias for ROWID.
**
** Also resolve function names and check the functions for proper
** usage. Make sure all function names are recognized and all functions
** have the correct number of arguments. Leave an error message
** in pParse->zErrMsg if anything is amiss. Return the number of errors.
**
** If the expression contains aggregate functions then set the EP_Agg
** property on the expression.
*/
int sqlite3ExprResolveNames(
NameContext *pNC, /* Namespace to resolve expressions in. */
Expr *pExpr /* The expression to be analyzed. */
){
int savedHasAgg;
if( pExpr==0 ) return 0;
#if SQLITE_MAX_EXPR_DEPTH>0
if( (pExpr->nHeight+pNC->pParse->nHeight)>SQLITE_MAX_EXPR_DEPTH ){
sqlite3ErrorMsg(pNC->pParse,
"Expression tree is too large (maximum depth %d)",
SQLITE_MAX_EXPR_DEPTH
);
return 1;
}
pNC->pParse->nHeight += pExpr->nHeight;
#endif
savedHasAgg = pNC->hasAgg;
pNC->hasAgg = 0;
walkExprTree(pExpr, nameResolverStep, pNC);
#if SQLITE_MAX_EXPR_DEPTH>0
pNC->pParse->nHeight -= pExpr->nHeight;
#endif
if( pNC->nErr>0 ){
ExprSetProperty(pExpr, EP_Error);
}
if( pNC->hasAgg ){
ExprSetProperty(pExpr, EP_Agg);
}else if( savedHasAgg ){
pNC->hasAgg = 1;
}
return ExprHasProperty(pExpr, EP_Error);
}
/*
** A pointer instance of this structure is used to pass information
** through walkExprTree into codeSubqueryStep().
*/
typedef struct QueryCoder QueryCoder;
struct QueryCoder {
Parse *pParse; /* The parsing context */
NameContext *pNC; /* Namespace of first enclosing query */
};
/*
** Generate code for scalar subqueries used as an expression
** and 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.
*/
#ifndef SQLITE_OMIT_SUBQUERY
void sqlite3CodeSubselect(Parse *pParse, Expr *pExpr){
int testAddr = 0; /* One-time test address */
Vdbe *v = sqlite3GetVdbe(pParse);
if( v==0 ) return;
/* 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) && !pParse->trigStack ){
int mem = pParse->nMem++;
sqlite3VdbeAddOp(v, OP_MemLoad, mem, 0);
testAddr = sqlite3VdbeAddOp(v, OP_If, 0, 0);
assert( testAddr>0 || sqlite3MallocFailed() );
sqlite3VdbeAddOp(v, OP_MemInt, 1, mem);
}
switch( pExpr->op ){
case TK_IN: {
char affinity;
KeyInfo keyInfo;
int addr; /* Address of OP_OpenEphemeral instruction */
affinity = sqlite3ExprAffinity(pExpr->pLeft);
/* Whether this is an 'x IN(SELECT...)' or an 'x IN(<exprlist>)'
** expression it is handled the same way. A virtual 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 = sqlite3VdbeAddOp(v, OP_OpenEphemeral, pExpr->iTable, 0);
memset(&keyInfo, 0, sizeof(keyInfo));
keyInfo.nField = 1;
sqlite3VdbeAddOp(v, OP_SetNumColumns, pExpr->iTable, 1);
if( pExpr->pSelect ){
/* Case 1: expr IN (SELECT ...)
**
** Generate code to write the results of the select into the temporary
** table allocated and opened above.
*/
int iParm = pExpr->iTable + (((int)affinity)<<16);
ExprList *pEList;
assert( (pExpr->iTable&0x0000FFFF)==pExpr->iTable );
if( sqlite3Select(pParse, pExpr->pSelect, SRT_Set, iParm, 0, 0, 0, 0) ){
return;
}
pEList = pExpr->pSelect->pEList;
if( pEList && pEList->nExpr>0 ){
keyInfo.aColl[0] = sqlite3BinaryCompareCollSeq(pParse, pExpr->pLeft,
pEList->a[0].pExpr);
}
}else if( pExpr->pList ){
/* 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->pList;
struct ExprList_item *pItem;
if( !affinity ){
affinity = SQLITE_AFF_NONE;
}
keyInfo.aColl[0] = pExpr->pLeft->pColl;
/* Loop through each expression in <exprlist>. */
for(i=pList->nExpr, pItem=pList->a; i>0; i--, pItem++){
Expr *pE2 = pItem->pExpr;
/* If the expression is not constant then we will need to
** disable the test that was generated above that makes sure
** this code only executes once. Because for a non-constant
** expression we need to rerun this code each time.
*/
if( testAddr>0 && !sqlite3ExprIsConstant(pE2) ){
sqlite3VdbeChangeToNoop(v, testAddr-1, 3);
testAddr = 0;
}
/* Evaluate the expression and insert it into the temp table */
sqlite3ExprCode(pParse, pE2);
sqlite3VdbeOp3(v, OP_MakeRecord, 1, 0, &affinity, 1);
sqlite3VdbeAddOp(v, OP_IdxInsert, pExpr->iTable, 0);
}
}
sqlite3VdbeChangeP3(v, addr, (void *)&keyInfo, P3_KEYINFO);
break;
}
case TK_EXISTS:
case TK_SELECT: {
/* 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.
*/
static const Token one = { (u8*)"1", 0, 1 };
Select *pSel;
int iMem;
int sop;
pExpr->iColumn = iMem = pParse->nMem++;
pSel = pExpr->pSelect;
if( pExpr->op==TK_SELECT ){
sop = SRT_Mem;
sqlite3VdbeAddOp(v, OP_MemNull, iMem, 0);
VdbeComment((v, "# Init subquery result"));
}else{
sop = SRT_Exists;
sqlite3VdbeAddOp(v, OP_MemInt, 0, iMem);
VdbeComment((v, "# Init EXISTS result"));
}
sqlite3ExprDelete(pSel->pLimit);
pSel->pLimit = sqlite3Expr(TK_INTEGER, 0, 0, &one);
if( sqlite3Select(pParse, pSel, sop, iMem, 0, 0, 0, 0) ){
return;
}
break;
}
}
if( testAddr ){
sqlite3VdbeJumpHere(v, testAddr);
}
return;
}
#endif /* SQLITE_OMIT_SUBQUERY */
/*
** Generate an instruction that will put the integer describe by
** text z[0..n-1] on the stack.
*/
static void codeInteger(Vdbe *v, const char *z, int n){
assert( z || sqlite3MallocFailed() );
if( z ){
int i;
if( sqlite3GetInt32(z, &i) ){
sqlite3VdbeAddOp(v, OP_Integer, i, 0);
}else if( sqlite3FitsIn64Bits(z) ){
sqlite3VdbeOp3(v, OP_Int64, 0, 0, z, n);
}else{
sqlite3VdbeOp3(v, OP_Real, 0, 0, z, n);
}
}
}
/*
** Generate code that will extract the iColumn-th column from
** table pTab and push that column value on the stack. There
** is an open cursor to pTab in iTable. If iColumn<0 then
** code is generated that extracts the rowid.
*/
void sqlite3ExprCodeGetColumn(Vdbe *v, Table *pTab, int iColumn, int iTable){
if( iColumn<0 ){
int op = (pTab && IsVirtual(pTab)) ? OP_VRowid : OP_Rowid;
sqlite3VdbeAddOp(v, op, iTable, 0);
}else if( pTab==0 ){
sqlite3VdbeAddOp(v, OP_Column, iTable, iColumn);
}else{
int op = IsVirtual(pTab) ? OP_VColumn : OP_Column;
sqlite3VdbeAddOp(v, op, iTable, iColumn);
sqlite3ColumnDefault(v, pTab, iColumn);
#ifndef SQLITE_OMIT_FLOATING_POINT
if( pTab->aCol[iColumn].affinity==SQLITE_AFF_REAL ){
sqlite3VdbeAddOp(v, OP_RealAffinity, 0, 0);
}
#endif
}
}
/*
** Generate code into the current Vdbe to evaluate the given
** expression and leave the result on the top of stack.
**
** 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 sqlite3ExprCode(Parse *pParse, Expr *pExpr){
Vdbe *v = pParse->pVdbe;
int op;
int stackChng = 1; /* Amount of change to stack depth */
if( v==0 ) return;
if( pExpr==0 ){
sqlite3VdbeAddOp(v, OP_Null, 0, 0);
return;
}
op = pExpr->op;
switch( op ){
case TK_AGG_COLUMN: {
AggInfo *pAggInfo = pExpr->pAggInfo;
struct AggInfo_col *pCol = &pAggInfo->aCol[pExpr->iAgg];
if( !pAggInfo->directMode ){
sqlite3VdbeAddOp(v, OP_MemLoad, pCol->iMem, 0);
break;
}else if( pAggInfo->useSortingIdx ){
sqlite3VdbeAddOp(v, OP_Column, pAggInfo->sortingIdx,
pCol->iSorterColumn);
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->ckOffset>0 );
sqlite3VdbeAddOp(v, OP_Dup, pParse->ckOffset-pExpr->iColumn-1, 1);
}else{
sqlite3ExprCodeGetColumn(v, pExpr->pTab, pExpr->iColumn, pExpr->iTable);
}
break;
}
case TK_INTEGER: {
codeInteger(v, (char*)pExpr->token.z, pExpr->token.n);
break;
}
case TK_FLOAT:
case TK_STRING: {
assert( TK_FLOAT==OP_Real );
assert( TK_STRING==OP_String8 );
sqlite3DequoteExpr(pExpr);
sqlite3VdbeOp3(v, op, 0, 0, (char*)pExpr->token.z, pExpr->token.n);
break;
}
case TK_NULL: {
sqlite3VdbeAddOp(v, OP_Null, 0, 0);
break;
}
#ifndef SQLITE_OMIT_BLOB_LITERAL
case TK_BLOB: {
int n;
const char *z;
assert( TK_BLOB==OP_HexBlob );
n = pExpr->token.n - 3;
z = (char*)pExpr->token.z + 2;
assert( n>=0 );
if( n==0 ){
z = "";
}
sqlite3VdbeOp3(v, op, 0, 0, z, n);
break;
}
#endif
case TK_VARIABLE: {
sqlite3VdbeAddOp(v, OP_Variable, pExpr->iTable, 0);
if( pExpr->token.n>1 ){
sqlite3VdbeChangeP3(v, -1, (char*)pExpr->token.z, pExpr->token.n);
}
break;
}
case TK_REGISTER: {
sqlite3VdbeAddOp(v, OP_MemLoad, pExpr->iTable, 0);
break;
}
#ifndef SQLITE_OMIT_CAST
case TK_CAST: {
/* Expressions of the form: CAST(pLeft AS token) */
int aff, to_op;
sqlite3ExprCode(pParse, pExpr->pLeft);
aff = sqlite3AffinityType(&pExpr->token);
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 );
sqlite3VdbeAddOp(v, to_op, 0, 0);
stackChng = 0;
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 );
sqlite3ExprCode(pParse, pExpr->pLeft);
sqlite3ExprCode(pParse, pExpr->pRight);
codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op, 0, 0);
stackChng = -1;
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 );
sqlite3ExprCode(pParse, pExpr->pLeft);
sqlite3ExprCode(pParse, pExpr->pRight);
sqlite3VdbeAddOp(v, op, 0, 0);
stackChng = -1;
break;
}
case TK_UMINUS: {
Expr *pLeft = pExpr->pLeft;
assert( pLeft );
if( pLeft->op==TK_FLOAT || pLeft->op==TK_INTEGER ){
Token *p = &pLeft->token;
char *z = sqlite3MPrintf("-%.*s", p->n, p->z);
if( pLeft->op==TK_FLOAT ){
sqlite3VdbeOp3(v, OP_Real, 0, 0, z, p->n+1);
}else{
codeInteger(v, z, p->n+1);
}
sqliteFree(z);
break;
}
/* Fall through into TK_NOT */
}
case TK_BITNOT:
case TK_NOT: {
assert( TK_BITNOT==OP_BitNot );
assert( TK_NOT==OP_Not );
sqlite3ExprCode(pParse, pExpr->pLeft);
sqlite3VdbeAddOp(v, op, 0, 0);
stackChng = 0;
break;
}
case TK_ISNULL:
case TK_NOTNULL: {
int dest;
assert( TK_ISNULL==OP_IsNull );
assert( TK_NOTNULL==OP_NotNull );
sqlite3VdbeAddOp(v, OP_Integer, 1, 0);
sqlite3ExprCode(pParse, pExpr->pLeft);
dest = sqlite3VdbeCurrentAddr(v) + 2;
sqlite3VdbeAddOp(v, op, 1, dest);
sqlite3VdbeAddOp(v, OP_AddImm, -1, 0);
stackChng = 0;
break;
}
case TK_AGG_FUNCTION: {
AggInfo *pInfo = pExpr->pAggInfo;
if( pInfo==0 ){
sqlite3ErrorMsg(pParse, "misuse of aggregate: %T",
&pExpr->span);
}else{
sqlite3VdbeAddOp(v, OP_MemLoad, pInfo->aFunc[pExpr->iAgg].iMem, 0);
}
break;
}
case TK_CONST_FUNC:
case TK_FUNCTION: {
ExprList *pList = pExpr->pList;
int nExpr = pList ? pList->nExpr : 0;
FuncDef *pDef;
int nId;
const char *zId;
int constMask = 0;
int i;
u8 enc = ENC(pParse->db);
CollSeq *pColl = 0;
zId = (char*)pExpr->token.z;
nId = pExpr->token.n;
pDef = sqlite3FindFunction(pParse->db, zId, nId, nExpr, enc, 0);
assert( pDef!=0 );
nExpr = sqlite3ExprCodeExprList(pParse, pList);
#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( nExpr>=2 && (pExpr->flags & EP_InfixFunc) ){
pDef = sqlite3VtabOverloadFunction(pDef, nExpr, pList->a[1].pExpr);
}else if( nExpr>0 ){
pDef = sqlite3VtabOverloadFunction(pDef, nExpr, pList->a[0].pExpr);
}
#endif
for(i=0; i<nExpr && i<32; i++){
if( sqlite3ExprIsConstant(pList->a[i].pExpr) ){
constMask |= (1<<i);
}
if( pDef->needCollSeq && !pColl ){
pColl = sqlite3ExprCollSeq(pParse, pList->a[i].pExpr);
}
}
if( pDef->needCollSeq ){
if( !pColl ) pColl = pParse->db->pDfltColl;
sqlite3VdbeOp3(v, OP_CollSeq, 0, 0, (char *)pColl, P3_COLLSEQ);
}
sqlite3VdbeOp3(v, OP_Function, constMask, nExpr, (char*)pDef, P3_FUNCDEF);
stackChng = 1-nExpr;
break;
}
#ifndef SQLITE_OMIT_SUBQUERY
case TK_EXISTS:
case TK_SELECT: {
if( pExpr->iColumn==0 ){
sqlite3CodeSubselect(pParse, pExpr);
}
sqlite3VdbeAddOp(v, OP_MemLoad, pExpr->iColumn, 0);
VdbeComment((v, "# load subquery result"));
break;
}
case TK_IN: {
int addr;
char affinity;
int ckOffset = pParse->ckOffset;
sqlite3CodeSubselect(pParse, pExpr);
/* Figure out the affinity to use to create a key from the results
** of the expression. affinityStr stores a static string suitable for
** P3 of OP_MakeRecord.
*/
affinity = comparisonAffinity(pExpr);
sqlite3VdbeAddOp(v, OP_Integer, 1, 0);
pParse->ckOffset = (ckOffset ? (ckOffset+1) : 0);
/* Code the <expr> from "<expr> IN (...)". The temporary table
** pExpr->iTable contains the values that make up the (...) set.
*/
sqlite3ExprCode(pParse, pExpr->pLeft);
addr = sqlite3VdbeCurrentAddr(v);
sqlite3VdbeAddOp(v, OP_NotNull, -1, addr+4); /* addr + 0 */
sqlite3VdbeAddOp(v, OP_Pop, 2, 0);
sqlite3VdbeAddOp(v, OP_Null, 0, 0);
sqlite3VdbeAddOp(v, OP_Goto, 0, addr+7);
sqlite3VdbeOp3(v, OP_MakeRecord, 1, 0, &affinity, 1); /* addr + 4 */
sqlite3VdbeAddOp(v, OP_Found, pExpr->iTable, addr+7);
sqlite3VdbeAddOp(v, OP_AddImm, -1, 0); /* addr + 6 */
break;
}
#endif
case TK_BETWEEN: {
Expr *pLeft = pExpr->pLeft;
struct ExprList_item *pLItem = pExpr->pList->a;
Expr *pRight = pLItem->pExpr;
sqlite3ExprCode(pParse, pLeft);
sqlite3VdbeAddOp(v, OP_Dup, 0, 0);
sqlite3ExprCode(pParse, pRight);
codeCompare(pParse, pLeft, pRight, OP_Ge, 0, 0);
sqlite3VdbeAddOp(v, OP_Pull, 1, 0);
pLItem++;
pRight = pLItem->pExpr;
sqlite3ExprCode(pParse, pRight);
codeCompare(pParse, pLeft, pRight, OP_Le, 0, 0);
sqlite3VdbeAddOp(v, OP_And, 0, 0);
break;
}
case TK_UPLUS: {
sqlite3ExprCode(pParse, pExpr->pLeft);
stackChng = 0;
break;
}
case TK_CASE: {
int expr_end_label;
int jumpInst;
int nExpr;
int i;
ExprList *pEList;
struct ExprList_item *aListelem;
assert(pExpr->pList);
assert((pExpr->pList->nExpr % 2) == 0);
assert(pExpr->pList->nExpr > 0);
pEList = pExpr->pList;
aListelem = pEList->a;
nExpr = pEList->nExpr;
expr_end_label = sqlite3VdbeMakeLabel(v);
if( pExpr->pLeft ){
sqlite3ExprCode(pParse, pExpr->pLeft);
}
for(i=0; i<nExpr; i=i+2){
sqlite3ExprCode(pParse, aListelem[i].pExpr);
if( pExpr->pLeft ){
sqlite3VdbeAddOp(v, OP_Dup, 1, 1);
jumpInst = codeCompare(pParse, pExpr->pLeft, aListelem[i].pExpr,
OP_Ne, 0, 1);
sqlite3VdbeAddOp(v, OP_Pop, 1, 0);
}else{
jumpInst = sqlite3VdbeAddOp(v, OP_IfNot, 1, 0);
}
sqlite3ExprCode(pParse, aListelem[i+1].pExpr);
sqlite3VdbeAddOp(v, OP_Goto, 0, expr_end_label);
sqlite3VdbeJumpHere(v, jumpInst);
}
if( pExpr->pLeft ){
sqlite3VdbeAddOp(v, OP_Pop, 1, 0);
}
if( pExpr->pRight ){
sqlite3ExprCode(pParse, pExpr->pRight);
}else{
sqlite3VdbeAddOp(v, OP_Null, 0, 0);
}
sqlite3VdbeResolveLabel(v, expr_end_label);
break;
}
#ifndef SQLITE_OMIT_TRIGGER
case TK_RAISE: {
if( !pParse->trigStack ){
sqlite3ErrorMsg(pParse,
"RAISE() may only be used within a trigger-program");
return;
}
if( pExpr->iColumn!=OE_Ignore ){
assert( pExpr->iColumn==OE_Rollback ||
pExpr->iColumn == OE_Abort ||
pExpr->iColumn == OE_Fail );
sqlite3DequoteExpr(pExpr);
sqlite3VdbeOp3(v, OP_Halt, SQLITE_CONSTRAINT, pExpr->iColumn,
(char*)pExpr->token.z, pExpr->token.n);
} else {
assert( pExpr->iColumn == OE_Ignore );
sqlite3VdbeAddOp(v, OP_ContextPop, 0, 0);
sqlite3VdbeAddOp(v, OP_Goto, 0, pParse->trigStack->ignoreJump);
VdbeComment((v, "# raise(IGNORE)"));
}
stackChng = 0;
break;
}
#endif
}
if( pParse->ckOffset ){
pParse->ckOffset += stackChng;
assert( pParse->ckOffset );
}
}
#ifndef SQLITE_OMIT_TRIGGER
/*
** Generate code that evalutes the given expression and leaves the result
** on the stack. See also sqlite3ExprCode().
**
** This routine might also cache the result and modify the pExpr tree
** so that it will make use of the cached result on subsequent evaluations
** rather than evaluate the whole expression again. Trivial expressions are
** not cached. If the expression is cached, its result is stored in a
** memory location.
*/
void sqlite3ExprCodeAndCache(Parse *pParse, Expr *pExpr){
Vdbe *v = pParse->pVdbe;
int iMem;
int addr1, addr2;
if( v==0 ) return;
addr1 = sqlite3VdbeCurrentAddr(v);
sqlite3ExprCode(pParse, pExpr);
addr2 = sqlite3VdbeCurrentAddr(v);
if( addr2>addr1+1 || sqlite3VdbeGetOp(v, addr1)->opcode==OP_Function ){
iMem = pExpr->iTable = pParse->nMem++;
sqlite3VdbeAddOp(v, OP_MemStore, iMem, 0);
pExpr->op = TK_REGISTER;
}
}
#endif
/*
** Generate code that pushes the value of every element of the given
** expression list onto the stack.
**
** Return the number of elements pushed onto the stack.
*/
int sqlite3ExprCodeExprList(
Parse *pParse, /* Parsing context */
ExprList *pList /* The expression list to be coded */
){
struct ExprList_item *pItem;
int i, n;
if( pList==0 ) return 0;
n = pList->nExpr;
for(pItem=pList->a, i=n; i>0; i--, pItem++){
sqlite3ExprCode(pParse, pItem->pExpr);
}
return n;
}
/*
** 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 true.
**
** 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 ckOffset = pParse->ckOffset;
if( v==0 || pExpr==0 ) return;
op = pExpr->op;
switch( op ){
case TK_AND: {
int d2 = sqlite3VdbeMakeLabel(v);
sqlite3ExprIfFalse(pParse, pExpr->pLeft, d2, !jumpIfNull);
sqlite3ExprIfTrue(pParse, pExpr->pRight, dest, jumpIfNull);
sqlite3VdbeResolveLabel(v, d2);
break;
}
case TK_OR: {
sqlite3ExprIfTrue(pParse, pExpr->pLeft, dest, jumpIfNull);
sqlite3ExprIfTrue(pParse, pExpr->pRight, dest, jumpIfNull);
break;
}
case TK_NOT: {
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 );
sqlite3ExprCode(pParse, pExpr->pLeft);
sqlite3ExprCode(pParse, pExpr->pRight);
codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op, dest, jumpIfNull);
break;
}
case TK_ISNULL:
case TK_NOTNULL: {
assert( TK_ISNULL==OP_IsNull );
assert( TK_NOTNULL==OP_NotNull );
sqlite3ExprCode(pParse, pExpr->pLeft);
sqlite3VdbeAddOp(v, op, 1, dest);
break;
}
case TK_BETWEEN: {
/* The expression "x BETWEEN y AND z" is implemented as:
**
** 1 IF (x < y) GOTO 3
** 2 IF (x <= z) GOTO <dest>
** 3 ...
*/
int addr;
Expr *pLeft = pExpr->pLeft;
Expr *pRight = pExpr->pList->a[0].pExpr;
sqlite3ExprCode(pParse, pLeft);
sqlite3VdbeAddOp(v, OP_Dup, 0, 0);
sqlite3ExprCode(pParse, pRight);
addr = codeCompare(pParse, pLeft, pRight, OP_Lt, 0, !jumpIfNull);
pRight = pExpr->pList->a[1].pExpr;
sqlite3ExprCode(pParse, pRight);
codeCompare(pParse, pLeft, pRight, OP_Le, dest, jumpIfNull);
sqlite3VdbeAddOp(v, OP_Integer, 0, 0);
sqlite3VdbeJumpHere(v, addr);
sqlite3VdbeAddOp(v, OP_Pop, 1, 0);
break;
}
default: {
sqlite3ExprCode(pParse, pExpr);
sqlite3VdbeAddOp(v, OP_If, jumpIfNull, dest);
break;
}
}
pParse->ckOffset = ckOffset;
}
/*
** 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 true or fall through if jumpIfNull is false.
*/
void sqlite3ExprIfFalse(Parse *pParse, Expr *pExpr, int dest, int jumpIfNull){
Vdbe *v = pParse->pVdbe;
int op = 0;
int ckOffset = pParse->ckOffset;
if( v==0 || 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: {
sqlite3ExprIfFalse(pParse, pExpr->pLeft, dest, jumpIfNull);
sqlite3ExprIfFalse(pParse, pExpr->pRight, dest, jumpIfNull);
break;
}
case TK_OR: {
int d2 = sqlite3VdbeMakeLabel(v);
sqlite3ExprIfTrue(pParse, pExpr->pLeft, d2, !jumpIfNull);
sqlite3ExprIfFalse(pParse, pExpr->pRight, dest, jumpIfNull);
sqlite3VdbeResolveLabel(v, d2);
break;
}
case TK_NOT: {
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: {
sqlite3ExprCode(pParse, pExpr->pLeft);
sqlite3ExprCode(pParse, pExpr->pRight);
codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op, dest, jumpIfNull);
break;
}
case TK_ISNULL:
case TK_NOTNULL: {
sqlite3ExprCode(pParse, pExpr->pLeft);
sqlite3VdbeAddOp(v, op, 1, dest);
break;
}
case TK_BETWEEN: {
/* The expression is "x BETWEEN y AND z". It is implemented as:
**
** 1 IF (x >= y) GOTO 3
** 2 GOTO <dest>
** 3 IF (x > z) GOTO <dest>
*/
int addr;
Expr *pLeft = pExpr->pLeft;
Expr *pRight = pExpr->pList->a[0].pExpr;
sqlite3ExprCode(pParse, pLeft);
sqlite3VdbeAddOp(v, OP_Dup, 0, 0);
sqlite3ExprCode(pParse, pRight);
addr = sqlite3VdbeCurrentAddr(v);
codeCompare(pParse, pLeft, pRight, OP_Ge, addr+3, !jumpIfNull);
sqlite3VdbeAddOp(v, OP_Pop, 1, 0);
sqlite3VdbeAddOp(v, OP_Goto, 0, dest);
pRight = pExpr->pList->a[1].pExpr;
sqlite3ExprCode(pParse, pRight);
codeCompare(pParse, pLeft, pRight, OP_Gt, dest, jumpIfNull);
break;
}
default: {
sqlite3ExprCode(pParse, pExpr);
sqlite3VdbeAddOp(v, OP_IfNot, jumpIfNull, dest);
break;
}
}
pParse->ckOffset = ckOffset;
}
/*
** Do a deep comparison of two expression trees. Return TRUE (non-zero)
** if they are identical and return FALSE if they differ in any way.
**
** Sometimes this routine will return FALSE even if the two expressions
** really are equivalent. If we cannot prove that the expressions are
** identical, we return FALSE just to be safe. So if this routine
** returns false, then you do not really know for certain if the two
** expressions are the same. But if you get a TRUE 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 FALSE - that
** just might result in some slightly slower code. But returning
** an incorrect TRUE could lead to a malfunction.
*/
int sqlite3ExprCompare(Expr *pA, Expr *pB){
int i;
if( pA==0||pB==0 ){
return pB==pA;
}
if( pA->op!=pB->op ) return 0;
if( (pA->flags & EP_Distinct)!=(pB->flags & EP_Distinct) ) return 0;
if( !sqlite3ExprCompare(pA->pLeft, pB->pLeft) ) return 0;
if( !sqlite3ExprCompare(pA->pRight, pB->pRight) ) return 0;
if( pA->pList ){
if( pB->pList==0 ) return 0;
if( pA->pList->nExpr!=pB->pList->nExpr ) return 0;
for(i=0; i<pA->pList->nExpr; i++){
if( !sqlite3ExprCompare(pA->pList->a[i].pExpr, pB->pList->a[i].pExpr) ){
return 0;
}
}
}else if( pB->pList ){
return 0;
}
if( pA->pSelect || pB->pSelect ) return 0;
if( pA->iTable!=pB->iTable || pA->iColumn!=pB->iColumn ) return 0;
if( pA->op!=TK_COLUMN && pA->token.z ){
if( pB->token.z==0 ) return 0;
if( pB->token.n!=pA->token.n ) return 0;
if( sqlite3StrNICmp((char*)pA->token.z,(char*)pB->token.z,pB->token.n)!=0 ){
return 0;
}
}
return 1;
}
/*
** 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(AggInfo *pInfo){
int i;
pInfo->aCol = sqlite3ArrayAllocate(
pInfo->aCol,
sizeof(pInfo->aCol[0]),
3,
&pInfo->nColumn,
&pInfo->nColumnAlloc,
&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(AggInfo *pInfo){
int i;
pInfo->aFunc = sqlite3ArrayAllocate(
pInfo->aFunc,
sizeof(pInfo->aFunc[0]),
3,
&pInfo->nFunc,
&pInfo->nFuncAlloc,
&i
);
return i;
}
/*
** This is an xFunc for walkExprTree() used to implement
** sqlite3ExprAnalyzeAggregates(). See sqlite3ExprAnalyzeAggregates
** for additional information.
**
** This routine analyzes the aggregate function at pExpr.
*/
static int analyzeAggregate(void *pArg, Expr *pExpr){
int i;
NameContext *pNC = (NameContext *)pArg;
Parse *pParse = pNC->pParse;
SrcList *pSrcList = pNC->pSrcList;
AggInfo *pAggInfo = pNC->pAggInfo;
switch( pExpr->op ){
case TK_AGG_COLUMN:
case TK_COLUMN: {
/* Check to see if the column is in one of the tables in the FROM
** clause of the aggregate query */
if( pSrcList ){
struct SrcList_item *pItem = pSrcList->a;
for(i=0; i<pSrcList->nSrc; i++, pItem++){
struct AggInfo_col *pCol;
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(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.
*/
pExpr->pAggInfo = pAggInfo;
pExpr->op = TK_AGG_COLUMN;
pExpr->iAgg = k;
break;
} /* endif pExpr->iTable==pItem->iCursor */
} /* end loop over pSrcList */
}
return 1;
}
case TK_AGG_FUNCTION: {
/* The pNC->nDepth==0 test causes aggregate functions in subqueries
** to be ignored */
if( pNC->nDepth==0 ){
/* Check to see if pExpr is a duplicate of another aggregate
** function that is already in the pAggInfo structure
*/
struct AggInfo_func *pItem = pAggInfo->aFunc;
for(i=0; i<pAggInfo->nFunc; i++, pItem++){
if( sqlite3ExprCompare(pItem->pExpr, pExpr) ){
break;
}
}
if( i>=pAggInfo->nFunc ){
/* pExpr is original. Make a new entry in pAggInfo->aFunc[]
*/
u8 enc = ENC(pParse->db);
i = addAggInfoFunc(pAggInfo);
if( i>=0 ){
pItem = &pAggInfo->aFunc[i];
pItem->pExpr = pExpr;
pItem->iMem = pParse->nMem++;
pItem->pFunc = sqlite3FindFunction(pParse->db,
(char*)pExpr->token.z, pExpr->token.n,
pExpr->pList ? pExpr->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
*/
pExpr->iAgg = i;
pExpr->pAggInfo = pAggInfo;
return 1;
}
}
}
/* Recursively walk subqueries looking for TK_COLUMN nodes that need
** to be changed to TK_AGG_COLUMN. But increment nDepth so that
** TK_AGG_FUNCTION nodes in subqueries will be unchanged.
*/
if( pExpr->pSelect ){
pNC->nDepth++;
walkSelectExpr(pExpr->pSelect, analyzeAggregate, pNC);
pNC->nDepth--;
}
return 0;
}
/*
** Analyze the given expression looking for aggregate functions and
** for variables that need to be added to the pParse->aAgg[] array.
** Make additional entries to the pParse->aAgg[] array as necessary.
**
** This routine should only be called after the expression has been
** analyzed by sqlite3ExprResolveNames().
**
** If errors are seen, leave an error message in zErrMsg and return
** the number of errors.
*/
int sqlite3ExprAnalyzeAggregates(NameContext *pNC, Expr *pExpr){
int nErr = pNC->pParse->nErr;
walkExprTree(pExpr, analyzeAggregate, pNC);
return pNC->pParse->nErr - nErr;
}
/*
** Call sqlite3ExprAnalyzeAggregates() for every expression in an
** expression list. Return the number of errors.
**
** If an error is found, the analysis is cut short.
*/
int sqlite3ExprAnalyzeAggList(NameContext *pNC, ExprList *pList){
struct ExprList_item *pItem;
int i;
int nErr = 0;
if( pList ){
for(pItem=pList->a, i=0; nErr==0 && i<pList->nExpr; i++, pItem++){
nErr += sqlite3ExprAnalyzeAggregates(pNC, pItem->pExpr);
}
}
return nErr;
}