expr.c.svn-base
上传用户:sunhongbo
上传日期:2022-01-25
资源大小:3010k
文件大小:109k
- /*
- ** 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 1.367 2008/04/15 12:14:22 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){
- char *zColl = 0; /* Dequoted name of collation sequence */
- CollSeq *pColl;
- zColl = sqlite3NameFromToken(pParse->db, pName);
- if( pExpr && zColl ){
- pColl = sqlite3LocateCollSeq(pParse, zColl, -1);
- if( pColl ){
- pExpr->pColl = pColl;
- pExpr->flags |= EP_ExpCollate;
- }
- }
- sqlite3_free(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;
- 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 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 = sqlite3CompareAffinity(pExpr1, aff) | 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 the operands for a comparison operation. Before
- ** generating the code for each operand, set the EP_AnyAff
- ** flag on the expression so that it will be able to used a
- ** cached column value that has previously undergone an
- ** affinity change.
- */
- static void codeCompareOperands(
- Parse *pParse, /* Parsing and code generating context */
- Expr *pLeft, /* The left operand */
- int *pRegLeft, /* Register where left operand is stored */
- int *pFreeLeft, /* Free this register when done */
- Expr *pRight, /* The right operand */
- int *pRegRight, /* Register where right operand is stored */
- int *pFreeRight /* Write temp register for right operand there */
- ){
- while( pLeft->op==TK_UPLUS ) pLeft = pLeft->pLeft;
- pLeft->flags |= EP_AnyAff;
- *pRegLeft = sqlite3ExprCodeTemp(pParse, pLeft, pFreeLeft);
- while( pRight->op==TK_UPLUS ) pRight = pRight->pLeft;
- pRight->flags |= EP_AnyAff;
- *pRegRight = sqlite3ExprCodeTemp(pParse, pRight, pFreeRight);
- }
- /*
- ** 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, p5);
- if( p5 & SQLITE_AFF_MASK ){
- sqlite3ExprCacheAffinityChange(pParse, in1, 1);
- sqlite3ExprCacheAffinityChange(pParse, in2, 1);
- }
- return addr;
- }
- /*
- ** Construct a new expression node and return a pointer to it. Memory
- ** for this node is obtained from sqlite3_malloc(). The calling function
- ** is responsible for making sure the node eventually gets freed.
- */
- Expr *sqlite3Expr(
- sqlite3 *db, /* Handle for sqlite3DbMallocZero() (may be null) */
- int op, /* Expression opcode */
- Expr *pLeft, /* Left operand */
- Expr *pRight, /* Right operand */
- const Token *pToken /* Argument token */
- ){
- Expr *pNew;
- static const Expr zeroExpr;
- pNew = sqlite3DbMallocRaw(db, 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 = zeroExpr;
- 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() except that it takes an extra Parse*
- ** argument and notifies the associated connection object if malloc fails.
- */
- Expr *sqlite3PExpr(
- Parse *pParse, /* Parsing context */
- int op, /* Expression opcode */
- Expr *pLeft, /* Left operand */
- Expr *pRight, /* Right operand */
- const Token *pToken /* Argument token */
- ){
- return sqlite3Expr(pParse->db, op, pLeft, pRight, pToken);
- }
- /*
- ** When doing a nested parse, you can include terms in an expression
- ** that look like this: #1 #2 ... These terms refer to registers
- ** in the virtual machine. #N is the N-th register.
- **
- ** 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;
- if( pParse->nested==0 ){
- sqlite3ErrorMsg(pParse, "near "%T": syntax error", pToken);
- return sqlite3PExpr(pParse, TK_NULL, 0, 0, 0);
- }
- if( v==0 ) return 0;
- p = sqlite3PExpr(pParse, TK_REGISTER, 0, 0, pToken);
- if( p==0 ){
- return 0; /* Malloc failed */
- }
- p->iTable = atoi((char*)&pToken->z[1]);
- return p;
- }
- /*
- ** Join two expressions using an AND operator. If either expression is
- ** NULL, then just return the other expression.
- */
- Expr *sqlite3ExprAnd(sqlite3 *db, Expr *pLeft, Expr *pRight){
- if( pLeft==0 ){
- return pRight;
- }else if( pRight==0 ){
- return pLeft;
- }else{
- return sqlite3Expr(db, 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( pExpr && 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(Parse *pParse, ExprList *pList, Token *pToken){
- Expr *pNew;
- assert( pToken );
- pNew = sqlite3DbMallocZero(pParse->db, 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 "$aaa" are assigned the same number
- ** as the previous instance of the same wildcard. Or if this is the first
- ** instance of the wildcard, the next sequenial variable number is
- ** assigned.
- */
- void sqlite3ExprAssignVarNumber(Parse *pParse, Expr *pExpr){
- Token *pToken;
- sqlite3 *db = pParse->db;
- if( pExpr==0 ) return;
- pToken = &pExpr->token;
- assert( pToken->n>=1 );
- assert( pToken->z!=0 );
- assert( pToken->z[0]!=0 );
- if( pToken->n==1 ){
- /* Wildcard of the form "?". Assign the next variable number */
- pExpr->iTable = ++pParse->nVar;
- }else if( pToken->z[0]=='?' ){
- /* Wildcard of the form "?nnn". Convert "nnn" to an integer and
- ** use it as the variable number */
- int i;
- pExpr->iTable = i = atoi((char*)&pToken->z[1]);
- testcase( i==0 );
- testcase( i==1 );
- testcase( i==db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER]-1 );
- testcase( i==db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER] );
- if( i<1 || i>db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER] ){
- sqlite3ErrorMsg(pParse, "variable number must be between ?1 and ?%d",
- db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER]);
- }
- if( i>pParse->nVar ){
- pParse->nVar = i;
- }
- }else{
- /* Wildcards of the form ":aaa" or "$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 =
- sqlite3DbReallocOrFree(
- db,
- pParse->apVarExpr,
- pParse->nVarExprAlloc*sizeof(pParse->apVarExpr[0])
- );
- }
- if( !db->mallocFailed ){
- assert( pParse->apVarExpr!=0 );
- pParse->apVarExpr[pParse->nVarExpr++] = pExpr;
- }
- }
- }
- if( !pParse->nErr && pParse->nVar>db->aLimit[SQLITE_LIMIT_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 ) sqlite3_free((char*)p->span.z);
- if( p->token.dyn ) sqlite3_free((char*)p->token.z);
- sqlite3ExprDelete(p->pLeft);
- sqlite3ExprDelete(p->pRight);
- sqlite3ExprListDelete(p->pList);
- sqlite3SelectDelete(p->pSelect);
- sqlite3_free(p);
- }
- /*
- ** The Expr.token field might be a string literal that is quoted.
- ** If so, remove the quotation marks.
- */
- void sqlite3DequoteExpr(sqlite3 *db, Expr *p){
- if( ExprHasAnyProperty(p, EP_Dequoted) ){
- return;
- }
- ExprSetProperty(p, EP_Dequoted);
- if( p->token.dyn==0 ){
- sqlite3TokenCopy(db, &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(sqlite3 *db, Expr *p){
- Expr *pNew;
- if( p==0 ) return 0;
- pNew = sqlite3DbMallocRaw(db, sizeof(*p) );
- if( pNew==0 ) return 0;
- memcpy(pNew, p, sizeof(*pNew));
- if( p->token.z!=0 ){
- pNew->token.z = (u8*)sqlite3DbStrNDup(db, (char*)p->token.z, p->token.n);
- pNew->token.dyn = 1;
- }else{
- assert( pNew->token.z==0 );
- }
- pNew->span.z = 0;
- pNew->pLeft = sqlite3ExprDup(db, p->pLeft);
- pNew->pRight = sqlite3ExprDup(db, p->pRight);
- pNew->pList = sqlite3ExprListDup(db, p->pList);
- pNew->pSelect = sqlite3SelectDup(db, p->pSelect);
- return pNew;
- }
- void sqlite3TokenCopy(sqlite3 *db, Token *pTo, Token *pFrom){
- if( pTo->dyn ) sqlite3_free((char*)pTo->z);
- if( pFrom->z ){
- pTo->n = pFrom->n;
- pTo->z = (u8*)sqlite3DbStrNDup(db, (char*)pFrom->z, pFrom->n);
- pTo->dyn = 1;
- }else{
- pTo->z = 0;
- }
- }
- ExprList *sqlite3ExprListDup(sqlite3 *db, ExprList *p){
- 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 = pNew->nAlloc = p->nExpr;
- pNew->a = pItem = sqlite3DbMallocRaw(db, p->nExpr*sizeof(p->a[0]) );
- if( pItem==0 ){
- sqlite3_free(pNew);
- return 0;
- }
- pOldItem = p->a;
- for(i=0; i<p->nExpr; i++, pItem++, pOldItem++){
- Expr *pNewExpr, *pOldExpr;
- pItem->pExpr = pNewExpr = sqlite3ExprDup(db, 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(db, &pNewExpr->span, &pOldExpr->span);
- }
- assert( pNewExpr==0 || pNewExpr->span.z!=0
- || pOldExpr->span.z==0
- || db->mallocFailed );
- pItem->zName = sqlite3DbStrDup(db, 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(sqlite3 *db, 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 = 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->isPopulated = pOldItem->isPopulated;
- pTab = pNewItem->pTab = pOldItem->pTab;
- if( pTab ){
- pTab->nRef++;
- }
- pNewItem->pSelect = sqlite3SelectDup(db, pOldItem->pSelect);
- pNewItem->pOn = sqlite3ExprDup(db, pOldItem->pOn);
- 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 = pNew->nAlloc = p->nId;
- pNew->a = sqlite3DbMallocRaw(db, p->nId*sizeof(p->a[0]) );
- if( pNew->a==0 ){
- sqlite3_free(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 = sqlite3DbStrDup(db, pOldItem->zName);
- pNewItem->idx = pOldItem->idx;
- }
- return pNew;
- }
- Select *sqlite3SelectDup(sqlite3 *db, Select *p){
- Select *pNew;
- if( p==0 ) return 0;
- pNew = sqlite3DbMallocRaw(db, sizeof(*p) );
- if( pNew==0 ) return 0;
- pNew->isDistinct = p->isDistinct;
- pNew->pEList = sqlite3ExprListDup(db, p->pEList);
- pNew->pSrc = sqlite3SrcListDup(db, p->pSrc);
- pNew->pWhere = sqlite3ExprDup(db, p->pWhere);
- pNew->pGroupBy = sqlite3ExprListDup(db, p->pGroupBy);
- pNew->pHaving = sqlite3ExprDup(db, p->pHaving);
- pNew->pOrderBy = sqlite3ExprListDup(db, p->pOrderBy);
- pNew->op = p->op;
- pNew->pPrior = sqlite3SelectDup(db, p->pPrior);
- pNew->pLimit = sqlite3ExprDup(db, p->pLimit);
- pNew->pOffset = sqlite3ExprDup(db, 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(sqlite3 *db, 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(
- Parse *pParse, /* Parsing context */
- ExprList *pList, /* List to which to append. Might be NULL */
- Expr *pExpr, /* Expression to be appended */
- Token *pName /* AS keyword for the expression */
- ){
- sqlite3 *db = pParse->db;
- if( pList==0 ){
- pList = sqlite3DbMallocZero(db, 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 = sqlite3DbRealloc(db, 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(db, 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,
- 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);
- }
- }
- /* 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;
- }
- /*
- ** 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);
- sqlite3_free(pItem->zName);
- }
- sqlite3_free(pList->a);
- sqlite3_free(pList);
- }
- /*
- ** Walk an expression tree. Call xFunc for each node visited. xFunc
- ** is called on the node before xFunc is called on the nodes children.
- **
- ** 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:
- testcase( pExpr->op==TK_SELECT );
- testcase( pExpr->op==TK_EXISTS );
- #endif
- testcase( pExpr->op==TK_ID );
- testcase( pExpr->op==TK_COLUMN );
- testcase( pExpr->op==TK_DOT );
- testcase( pExpr->op==TK_AGG_FUNCTION );
- testcase( pExpr->op==TK_AGG_COLUMN );
- *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 */
- Schema *pSchema = 0; /* Schema of the expression */
- assert( pColumnToken && pColumnToken->z ); /* The Z in X.Y.Z cannot be NULL */
- zDb = sqlite3NameFromToken(db, pDbToken);
- zTab = sqlite3NameFromToken(db, pTableToken);
- zCol = sqlite3NameFromToken(db, pColumnToken);
- if( db->mallocFailed ){
- 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;
- 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;
- 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;
- u32 *piColMask;
- if( pTriggerStack->newIdx != -1 && sqlite3StrICmp("new", zTab) == 0 ){
- pExpr->iTable = pTriggerStack->newIdx;
- assert( pTriggerStack->pTab );
- pTab = pTriggerStack->pTab;
- piColMask = &(pTriggerStack->newColMask);
- }else if( pTriggerStack->oldIdx != -1 && sqlite3StrICmp("old", zTab)==0 ){
- pExpr->iTable = pTriggerStack->oldIdx;
- assert( pTriggerStack->pTab );
- pTab = pTriggerStack->pTab;
- piColMask = &(pTriggerStack->oldColMask);
- }
- if( pTab ){
- int iCol;
- Column *pCol = pTab->aCol;
- 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;
- if( iCol>=0 ){
- testcase( iCol==31 );
- testcase( iCol==32 );
- *piColMask |= ((u32)1<<iCol) | (iCol>=32?0xffffffff:0);
- }
- 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);
- sqlite3_free(zCol);
- return 2;
- }
- pDup = sqlite3ExprDup(db, pOrig);
- if( pExpr->flags & EP_ExpCollate ){
- pDup->pColl = pExpr->pColl;
- pDup->flags |= EP_ExpCollate;
- }
- if( pExpr->span.dyn ) sqlite3_free((char*)pExpr->span.z);
- if( pExpr->token.dyn ) sqlite3_free((char*)pExpr->token.z);
- memcpy(pExpr, pDup, sizeof(*pExpr));
- sqlite3_free(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]=='"' ){
- sqlite3_free(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 ){
- const char *zErr;
- zErr = cnt==0 ? "no such column" : "ambiguous column name";
- if( zDb ){
- sqlite3ErrorMsg(pParse, "%s: %s.%s.%s", zErr, zDb, zTab, zCol);
- }else if( zTab ){
- sqlite3ErrorMsg(pParse, "%s: %s.%s", zErr, zTab, zCol);
- }else{
- sqlite3ErrorMsg(pParse, "%s: %s", zErr, zCol);
- }
- 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;
- testcase( n==sizeof(Bitmask)*8-1 );
- 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
- */
- sqlite3_free(zDb);
- sqlite3_free(zTab);
- sqlite3ExprDelete(pExpr->pLeft);
- pExpr->pLeft = 0;
- sqlite3ExprDelete(pExpr->pRight);
- pExpr->pRight = 0;
- pExpr->op = TK_COLUMN;
- lookupname_end_2:
- sqlite3_free(zCol);
- if( cnt==1 ){
- assert( pNC!=0 );
- sqlite3AuthRead(pParse, pExpr, pSchema, 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
- {
- int mxDepth = pNC->pParse->db->aLimit[SQLITE_LIMIT_EXPR_DEPTH];
- if( (pExpr->nHeight+pNC->pParse->nHeight)>mxDepth ){
- sqlite3ErrorMsg(pNC->pParse,
- "Expression tree is too large (maximum depth %d)", mxDepth
- );
- 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 */
- };
- #ifdef SQLITE_TEST
- int sqlite3_enable_in_opt = 1;
- #else
- #define sqlite3_enable_in_opt 1
- #endif
- /*
- ** 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 cursor opened on the structure (database table, database index
- ** or ephermal table) is stored in pX->iTable before this function returns.
- ** The returned value indicates the structure 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 structure may only be used if the SELECT is of the simple
- ** form:
- **
- ** SELECT <column> FROM <table>
- **
- ** If the mustBeUnique parameter is false, the structure 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.
- **
- ** If mustBeUnique is true, then the structure 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
- ** is unique by virtue of a constraint or implicit index.
- */
- #ifndef SQLITE_OMIT_SUBQUERY
- int sqlite3FindInIndex(Parse *pParse, Expr *pX, int mustBeUnique){
- Select *p;
- int eType = 0;
- int iTab = pParse->nTab++;
- /* The follwing if(...) expression is true if the SELECT is of the
- ** simple form:
- **
- ** SELECT <column> FROM <table>
- **
- ** If this is the case, it may be possible to use an existing table
- ** or index instead of generating an epheremal table.
- */
- if( sqlite3_enable_in_opt
- && (p=pX->pSelect)!=0 && !p->pPrior
- && !p->isDistinct && !p->isAgg && !p->pGroupBy
- && p->pSrc && p->pSrc->nSrc==1 && !p->pSrc->a[0].pSelect
- && p->pSrc->a[0].pTab && !p->pSrc->a[0].pTab->pSelect
- && p->pEList->nExpr==1 && p->pEList->a[0].pExpr->op==TK_COLUMN
- && !p->pLimit && !p->pOffset && !p->pWhere
- ){
- sqlite3 *db = pParse->db;
- Index *pIdx;
- Expr *pExpr = p->pEList->a[0].pExpr;
- int iCol = pExpr->iColumn;
- Vdbe *v = sqlite3GetVdbe(pParse);
- /* 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 iMem = ++pParse->nMem;
- int iAddr;
- Table *pTab = p->pSrc->a[0].pTab;
- int iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
- sqlite3VdbeUsesBtree(v, iDb);
- iAddr = sqlite3VdbeAddOp1(v, OP_If, iMem);
- sqlite3VdbeAddOp2(v, OP_Integer, 1, iMem);
- sqlite3OpenTable(pParse, iTab, iDb, pTab, OP_OpenRead);
- eType = IN_INDEX_ROWID;
- sqlite3VdbeJumpHere(v, iAddr);
- }else{
- /* 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.
- */
- Table *pTab = p->pSrc->a[0].pTab;
- 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)
- && (pReq==sqlite3FindCollSeq(db, ENC(db), pIdx->azColl[0], -1, 0))
- && (!mustBeUnique || (pIdx->nColumn==1 && pIdx->onError!=OE_None))
- ){
- int iDb;
- int iMem = ++pParse->nMem;
- int iAddr;
- char *pKey;
-
- pKey = (char *)sqlite3IndexKeyinfo(pParse, pIdx);
- iDb = sqlite3SchemaToIndex(db, pIdx->pSchema);
- sqlite3VdbeUsesBtree(v, iDb);
- iAddr = sqlite3VdbeAddOp1(v, OP_If, iMem);
- sqlite3VdbeAddOp2(v, OP_Integer, 1, iMem);
-
- sqlite3VdbeAddOp2(v, OP_SetNumColumns, 0, pIdx->nColumn);
- 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( eType==0 ){
- sqlite3CodeSubselect(pParse, pX);
- eType = IN_INDEX_EPH;
- }else{
- pX->iTable = iTab;
- }
- return eType;
- }
- #endif
- /*
- ** 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;
- sqlite3VdbeAddOp1(v, OP_If, mem);
- testAddr = sqlite3VdbeAddOp2(v, OP_Integer, 1, mem);
- assert( testAddr>0 || pParse->db->mallocFailed );
- }
- 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 = sqlite3VdbeAddOp2(v, OP_OpenEphemeral, pExpr->iTable, 1);
- memset(&keyInfo, 0, sizeof(keyInfo));
- keyInfo.nField = 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.
- */
- SelectDest dest;
- ExprList *pEList;
- sqlite3SelectDestInit(&dest, SRT_Set, pExpr->iTable);
- dest.affinity = (int)affinity;
- assert( (pExpr->iTable&0x0000FFFF)==pExpr->iTable );
- if( sqlite3Select(pParse, pExpr->pSelect, &dest, 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;
- int r1, r2;
- if( !affinity ){
- affinity = SQLITE_AFF_NONE;
- }
- keyInfo.aColl[0] = pExpr->pLeft->pColl;
- /* Loop through each expression in <exprlist>. */
- r1 = sqlite3GetTempReg(pParse);
- r2 = sqlite3GetTempReg(pParse);
- for(i=pList->nExpr, pItem=pList->a; i>0; i--, pItem++){
- Expr *pE2 = pItem->pExpr;
- /* If the expression is not constant then we will need to
- ** disable the test that was generated above that makes sure
- ** this code only executes once. Because for a non-constant
- ** expression we need to rerun this code each time.
- */
- if( testAddr && !sqlite3ExprIsConstant(pE2) ){
- sqlite3VdbeChangeToNoop(v, testAddr-1, 2);
- testAddr = 0;
- }
- /* Evaluate the expression and insert it into the temp table */
- pParse->disableColCache++;
- sqlite3ExprCode(pParse, pE2, r1);
- assert( pParse->disableColCache>0 );
- pParse->disableColCache--;
- sqlite3VdbeAddOp4(v, OP_MakeRecord, r1, 1, r2, &affinity, 1);
- sqlite3ExprCacheAffinityChange(pParse, r1, 1);
- sqlite3VdbeAddOp2(v, OP_IdxInsert, pExpr->iTable, r2);
- }
- sqlite3ReleaseTempReg(pParse, r1);
- sqlite3ReleaseTempReg(pParse, r2);
- }
- sqlite3VdbeChangeP4(v, addr, (void *)&keyInfo, P4_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;
- SelectDest dest;
- pSel = pExpr->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(pSel->pLimit);
- pSel->pLimit = sqlite3PExpr(pParse, TK_INTEGER, 0, 0, &one);
- if( sqlite3Select(pParse, pSel, &dest, 0, 0, 0, 0) ){
- return;
- }
- pExpr->iColumn = dest.iParm;
- break;
- }
- }
- if( testAddr ){
- sqlite3VdbeJumpHere(v, testAddr-1);
- }
- return;
- }
- #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;
- }
- /*
- ** 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 n, int negateFlag, int iMem){
- assert( z || v==0 || sqlite3VdbeDb(v)->mallocFailed );
- if( z ){
- double value;
- char *zV;
- assert( !isdigit(z[n]) );
- sqlite3AtoF(z, &value);
- if( negateFlag ) value = -value;
- zV = dup8bytes(v, (char*)&value);
- sqlite3VdbeAddOp4(v, OP_Real, 0, iMem, 0, zV, P4_REAL);
- }
- }
- /*
- ** Generate an instruction that will put the integer describe by
- ** text 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 codeInteger(Vdbe *v, const char *z, int n, int negFlag, int iMem){
- assert( z || v==0 || sqlite3VdbeDb(v)->mallocFailed );
- if( z ){
- int i;
- assert( !isdigit(z[n]) );
- if( sqlite3GetInt32(z, &i) ){
- if( negFlag ) i = -i;
- sqlite3VdbeAddOp2(v, OP_Integer, i, iMem);
- }else if( sqlite3FitsIn64Bits(z, negFlag) ){
- i64 value;
- char *zV;
- sqlite3Atoi64(z, &value);
- if( negFlag ) value = -value;
- zV = dup8bytes(v, (char*)&value);
- sqlite3VdbeAddOp4(v, OP_Int64, 0, iMem, 0, zV, P4_INT64);
- }else{
- codeReal(v, z, n, negFlag, iMem);
- }
- }
- }
- /*
- ** 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.
- **
- ** This routine might attempt to reuse the value of the column that
- ** has already been loaded into a register. The value will always
- ** be used if it has not undergone any affinity changes. But if
- ** an affinity change has occurred, then the cached value will only be
- ** used if allowAffChng is true.
- */
- 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 */
- int allowAffChng /* True if prior affinity changes are OK */
- ){
- Vdbe *v = pParse->pVdbe;
- int i;
- struct yColCache *p;
- for(i=0, p=pParse->aColCache; i<pParse->nColCache; i++, p++){
- if( p->iTable==iTable && p->iColumn==iColumn
- && (!p->affChange || allowAffChng) ){
- #if 0
- sqlite3VdbeAddOp0(v, OP_Noop);
- VdbeComment((v, "OPT: tab%d.col%d -> r%d", iTable, iColumn, p->iReg));
- #endif
- return p->iReg;
- }
- }
- assert( v!=0 );
- if( iColumn<0 ){
- int op = (pTab && IsVirtual(pTab)) ? OP_VRowid : OP_Rowid;
- sqlite3VdbeAddOp2(v, op, iTable, iReg);
- }else if( pTab==0 ){
- sqlite3VdbeAddOp3(v, OP_Column, iTable, iColumn, iReg);
- }else{
- int op = IsVirtual(pTab) ? OP_VColumn : OP_Column;
- sqlite3VdbeAddOp3(v, op, iTable, iColumn, iReg);
- sqlite3ColumnDefault(v, pTab, iColumn);
- #ifndef SQLITE_OMIT_FLOATING_POINT
- if( pTab->aCol[iColumn].affinity==SQLITE_AFF_REAL ){
- sqlite3VdbeAddOp1(v, OP_RealAffinity, iReg);
- }
- #endif
- }
- if( pParse->disableColCache==0 ){
- i = pParse->iColCache;
- p = &pParse->aColCache[i];
- p->iTable = iTable;
- p->iColumn = iColumn;
- p->iReg = iReg;
- p->affChange = 0;
- i++;
- if( i>=ArraySize(pParse->aColCache) ) i = 0;
- if( i>pParse->nColCache ) pParse->nColCache = i;
- pParse->iColCache = i;
- }
- return iReg;
- }
- /*
- ** Clear all column cache entries associated with the vdbe
- ** cursor with cursor number iTable.
- */
- void sqlite3ExprClearColumnCache(Parse *pParse, int iTable){
- if( iTable<0 ){
- pParse->nColCache = 0;
- pParse->iColCache = 0;
- }else{
- int i;
- for(i=0; i<pParse->nColCache; i++){
- if( pParse->aColCache[i].iTable==iTable ){
- testcase( i==pParse->nColCache-1 );
- pParse->aColCache[i] = pParse->aColCache[--pParse->nColCache];
- pParse->iColCache = pParse->nColCache;
- }
- }
- }
- }
- /*
- ** Record the fact that an affinity change has occurred on iCount
- ** registers starting with iStart.
- */
- void sqlite3ExprCacheAffinityChange(Parse *pParse, int iStart, int iCount){
- int iEnd = iStart + iCount - 1;
- int i;
- for(i=0; i<pParse->nColCache; i++){
- int r = pParse->aColCache[i].iReg;
- if( r>=iStart && r<=iEnd ){
- pParse->aColCache[i].affChange = 1;
- }
- }
- }
- /*
- ** Generate code to moves content from one register to another.
- ** Keep the column cache up-to-date.
- */
- void sqlite3ExprCodeMove(Parse *pParse, int iFrom, int iTo){
- int i;
- if( iFrom==iTo ) return;
- sqlite3VdbeAddOp2(pParse->pVdbe, OP_Move, iFrom, iTo);
- for(i=0; i<pParse->nColCache; i++){
- if( pParse->aColCache[i].iReg==iFrom ){
- pParse->aColCache[i].iReg = iTo;
- }
- }
- }
- /*
- ** Return true if any register in the range iFrom..iTo (inclusive)
- ** is used as part of the column cache.
- */
- static int usedAsColumnCache(Parse *pParse, int iFrom, int iTo){
- int i;
- for(i=0; i<pParse->nColCache; i++){
- int r = pParse->aColCache[i].iReg;
- if( r>=iFrom && r<=iTo ) return 1;
- }
- return 0;
- }
- /*
- ** Theres is a value in register iCurrent. We ultimately want
- ** the value to be in register iTarget. It might be that
- ** iCurrent and iTarget are the same register.
- **
- ** We are going to modify the value, so we need to make sure it
- ** is not a cached register. If iCurrent is a cached register,
- ** then try to move the value over to iTarget. If iTarget is a
- ** cached register, then clear the corresponding cache line.
- **
- ** Return the register that the value ends up in.
- */
- int sqlite3ExprWritableRegister(Parse *pParse, int iCurrent, int iTarget){
- int i;
- assert( pParse->pVdbe!=0 );
- if( !usedAsColumnCache(pParse, iCurrent, iCurrent) ){
- return iCurrent;
- }
- if( iCurrent!=iTarget ){
- sqlite3VdbeAddOp2(pParse->pVdbe, OP_SCopy, iCurrent, iTarget);
- }
- for(i=0; i<pParse->nColCache; i++){
- if( pParse->aColCache[i].iReg==iTarget ){
- pParse->aColCache[i] = pParse->aColCache[--pParse->nColCache];
- pParse->iColCache = pParse->nColCache;
- }
- }
- return iTarget;
- }
- /*
- ** If the last instruction coded is an ephemeral copy of any of
- ** the registers in the nReg registers beginning with iReg, then
- ** convert the last instruction from OP_SCopy to OP_Copy.
- */
- void sqlite3ExprHardCopy(Parse *pParse, int iReg, int nReg){
- int addr;
- VdbeOp *pOp;
- Vdbe *v;
- v = pParse->pVdbe;
- addr = sqlite3VdbeCurrentAddr(v);
- pOp = sqlite3VdbeGetOp(v, addr-1);
- if( pOp->opcode==OP_SCopy && pOp->p1>=iReg && pOp->p1<iReg+nReg ){
- pOp->opcode = OP_Copy;
- }
- }
- /*
- ** 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 guaranteed 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 */
- assert( v!=0 || pParse->db->mallocFailed );
- assert( target>0 && target<=pParse->nMem );
- if( v==0 ) 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->sortingIdx,
- 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{
- testcase( (pExpr->flags & EP_AnyAff)!=0 );
- inReg = sqlite3ExprCodeGetColumn(pParse, pExpr->pTab,
- pExpr->iColumn, pExpr->iTable, target,
- pExpr->flags & EP_AnyAff);
- }
- break;
- }
- case TK_INTEGER: {
- codeInteger(v, (char*)pExpr->token.z, pExpr->token.n, 0, target);
- break;
- }
- case TK_FLOAT: {
- codeReal(v, (char*)pExpr->token.z, pExpr->token.n, 0, target);
- break;
- }
- case TK_STRING: {
- sqlite3DequoteExpr(pParse->db, pExpr);
- sqlite3VdbeAddOp4(v,OP_String8, 0, target, 0,
- (char*)pExpr->token.z, pExpr->token.n);
- 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( pExpr->token.n>=3 );
- assert( pExpr->token.z[0]=='x' || pExpr->token.z[0]=='X' );
- assert( pExpr->token.z[1]==''' );
- assert( pExpr->token.z[pExpr->token.n-1]==''' );
- n = pExpr->token.n - 3;
- z = (char*)pExpr->token.z + 2;
- zBlob = sqlite3HexToBlob(sqlite3VdbeDb(v), z, n);
- sqlite3VdbeAddOp4(v, OP_Blob, n/2, target, 0, zBlob, P4_DYNAMIC);
- break;
- }
- #endif
- case TK_VARIABLE: {
- sqlite3VdbeAddOp2(v, OP_Variable, pExpr->iTable, target);
- if( pExpr->token.n>1 ){
- sqlite3VdbeChangeP4(v, -1, (char*)pExpr->token.z, pExpr->token.n);
- }
- break;
- }
- case TK_REGISTER: {
- inReg = pExpr->iTable;
- 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);
- 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 );
- 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 );
- 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 );
- codeCompareOperands(pParse, pExpr->pLeft, &r1, ®Free1,
- pExpr->pRight, &r2, ®Free2);
- codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op,
- r1, r2, inReg, SQLITE_STOREP2);
- 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, ®Free1);
- r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, ®Free2);
- 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_FLOAT || pLeft->op==TK_INTEGER ){
- Token *p = &pLeft->token;
- if( pLeft->op==TK_FLOAT ){
- codeReal(v, (char*)p->z, p->n, 1, target);
- }else{
- codeInteger(v, (char*)p->z, p->n, 1, target);
- }
- }else{
- regFree1 = r1 = sqlite3GetTempReg(pParse);
- sqlite3VdbeAddOp2(v, OP_Integer, 0, r1);
- r2 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free2);
- 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 );
- inReg = sqlite3ExprCodeTarget(pParse, pExpr->pLeft, target);
- testcase( inReg==target );
- testcase( usedAsColumnCache(pParse, inReg, inReg) );
- inReg = sqlite3ExprWritableRegister(pParse, inReg, target);
- sqlite3VdbeAddOp1(v, op, 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, ®Free1);
- 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 ){
- sqlite3ErrorMsg(pParse, "misuse of aggregate: %T",
- &pExpr->span);
- }else{
- inReg = pInfo->aFunc[pExpr->iAgg].iMem;
- }
- 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;
- sqlite3 *db = pParse->db;
- u8 enc = ENC(db);
- CollSeq *pColl = 0;
- testcase( op==TK_CONST_FUNC );
- testcase( op==TK_FUNCTION );
- zId = (char*)pExpr->token.z;
- nId = pExpr->token.n;
- pDef = sqlite3FindFunction(pParse->db, zId, nId, nExpr, enc, 0);
- assert( pDef!=0 );
- if( pList ){
- nExpr = pList->nExpr;
- r1 = sqlite3GetTempRange(pParse, nExpr);
- sqlite3ExprCodeExprList(pParse, pList, r1, 1);
- }else{
- nExpr = 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( nExpr>=2 && (pExpr->flags & EP_InfixFunc) ){
- pDef = sqlite3VtabOverloadFunction(db, pDef, nExpr, pList->a[1].pExpr);
- }else if( nExpr>0 ){
- pDef = sqlite3VtabOverloadFunction(db, 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;
- sqlite3VdbeAddOp4(v, OP_CollSeq, 0, 0, 0, (char *)pColl, P4_COLLSEQ);
- }
- sqlite3VdbeAddOp4(v, OP_Function, constMask, r1, target,
- (char*)pDef, P4_FUNCDEF);
- sqlite3VdbeChangeP5(v, nExpr);
- if( nExpr ){
- sqlite3ReleaseTempRange(pParse, r1, nExpr);
- }
- sqlite3ExprCacheAffinityChange(pParse, r1, nExpr);
- break;
- }
- #ifndef SQLITE_OMIT_SUBQUERY
- case TK_EXISTS:
- case TK_SELECT: {
- testcase( op==TK_EXISTS );
- testcase( op==TK_SELECT );
- if( pExpr->iColumn==0 ){
- sqlite3CodeSubselect(pParse, pExpr);
- }
- inReg = pExpr->iColumn;
- break;
- }
- case TK_IN: {
- int j1, j2, j3, j4, j5;
- char affinity;
- int eType;
- eType = sqlite3FindInIndex(pParse, pExpr, 0);
- /* 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);
- sqlite3VdbeAddOp2(v, OP_Integer, 1, target);
- /* Code the <expr> from "<expr> IN (...)". The temporary table
- ** pExpr->iTable contains the values that make up the (...) set.
- */
- r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free1);
- testcase( regFree1==0 );
- j1 = sqlite3VdbeAddOp1(v, OP_NotNull, r1);
- sqlite3VdbeAddOp2(v, OP_Null, 0, target);
- j2 = sqlite3VdbeAddOp0(v, OP_Goto);
- sqlite3VdbeJumpHere(v, j1);
- if( eType==IN_INDEX_ROWID ){
- j3 = sqlite3VdbeAddOp1(v, OP_MustBeInt, r1);
- j4 = sqlite3VdbeAddOp3(v, OP_NotExists, pExpr->iTable, 0, r1);
- j5 = sqlite3VdbeAddOp0(v, OP_Goto);
- sqlite3VdbeJumpHere(v, j3);
- sqlite3VdbeJumpHere(v, j4);
- }else{
- r2 = regFree2 = sqlite3GetTempReg(pParse);
- sqlite3VdbeAddOp4(v, OP_MakeRecord, r1, 1, r2, &affinity, 1);
- sqlite3ExprCacheAffinityChange(pParse, r1, 1);
- j5 = sqlite3VdbeAddOp3(v, OP_Found, pExpr->iTable, 0, r2);
- }
- sqlite3VdbeAddOp2(v, OP_AddImm, target, -1);
- sqlite3VdbeJumpHere(v, j2);
- sqlite3VdbeJumpHere(v, j5);
- break;
- }
- #endif
- /*
- ** 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->pList->a;
- Expr *pRight = pLItem->pExpr;
- codeCompareOperands(pParse, pLeft, &r1, ®Free1,
- pRight, &r2, ®Free2);
- 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, ®Free2);
- 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;
- }
- /*
- ** 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.
- */
- case TK_CASE: {
- int endLabel; /* GOTO label for end of CASE stmt */
- int nextCase; /* GOTO label for next WHEN clause */
- int nExpr; /* 2x number of WHEN terms */
- int i; /* Loop counter */
- ExprList *pEList; /* List of WHEN terms */
- struct ExprList_item *aListelem; /* Array of WHEN terms */
- Expr opCompare; /* The X==Ei expression */
- Expr cacheX; /* Cached expression X */
- Expr *pX; /* The X expression */
- Expr *pTest; /* X==Ei (form A) or just Ei (form B) */
- assert(pExpr->pList);
- assert((pExpr->pList->nExpr % 2) == 0);
- assert(pExpr->pList->nExpr > 0);
- pEList = pExpr->pList;
- aListelem = pEList->a;
- nExpr = pEList->nExpr;
- endLabel = sqlite3VdbeMakeLabel(v);
- if( (pX = pExpr->pLeft)!=0 ){
- cacheX = *pX;
- testcase( pX->op==TK_COLUMN || pX->op==TK_REGISTER );
- cacheX.iTable = sqlite3ExprCodeTemp(pParse, pX, ®Free1);
- testcase( regFree1==0 );
- cacheX.op = TK_REGISTER;
- cacheX.iColumn = 0;
- opCompare.op = TK_EQ;
- opCompare.pLeft = &cacheX;
- pTest = &opCompare;
- }
- pParse->disableColCache++;
- for(i=0; i<nExpr; i=i+2){
- if( pX ){
- opCompare.pRight = aListelem[i].pExpr;
- }else{
- pTest = aListelem[i].pExpr;
- }
- nextCase = sqlite3VdbeMakeLabel(v);
- testcase( pTest->op==TK_COLUMN || pTest->op==TK_REGISTER );
- 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);
- sqlite3VdbeResolveLabel(v, nextCase);
- }
- if( pExpr->pRight ){
- sqlite3ExprCode(pParse, pExpr->pRight, target);
- }else{
- sqlite3VdbeAddOp2(v, OP_Null, 0, target);
- }
- sqlite3VdbeResolveLabel(v, endLabel);
- assert( pParse->disableColCache>0 );
- pParse->disableColCache--;
- break;
- }
- #ifndef SQLITE_OMIT_TRIGGER
- case TK_RAISE: {
- if( !pParse->trigStack ){
- sqlite3ErrorMsg(pParse,
- "RAISE() may only be used within a trigger-program");
- return 0;
- }
- if( pExpr->iColumn!=OE_Ignore ){
- assert( pExpr->iColumn==OE_Rollback ||
- pExpr->iColumn == OE_Abort ||
- pExpr->iColumn == OE_Fail );
- sqlite3DequoteExpr(pParse->db, pExpr);
- sqlite3VdbeAddOp4(v, OP_Halt, SQLITE_CONSTRAINT, pExpr->iColumn, 0,
- (char*)pExpr->token.z, pExpr->token.n);
- } else {
- assert( pExpr->iColumn == OE_Ignore );
- sqlite3VdbeAddOp2(v, OP_ContextPop, 0, 0);
- sqlite3VdbeAddOp2(v, OP_Goto, 0, pParse->trigStack->ignoreJump);
- VdbeComment((v, "raise(IGNORE)"));
- }
- 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 );
- 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 );
- if( pExpr->op!=TK_REGISTER ){
- int iMem;
- iMem = ++pParse->nMem;
- sqlite3VdbeAddOp2(v, OP_Copy, inReg, iMem);
- pExpr->iTable = iMem;
- pExpr->iColumn = pExpr->op;
- pExpr->op = TK_REGISTER;
- }
- return inReg;
- }
- /*
- ** 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(void *pArg, Expr *pExpr){
- Parse *pParse = (Parse*)pArg;
- switch( pExpr->op ){
- case TK_REGISTER: {
- return 1;
- }
- 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->pList;
- if( pList ){
- int i = pList->nExpr;
- struct ExprList_item *pItem = pList->a;
- for(; i>0; i--, pItem++){
- if( pItem->pExpr ) pItem->pExpr->flags |= EP_FixedDest;
- }
- }
- break;
- }
- }
- if( isAppropriateForFactoring(pExpr) ){
- int r1 = ++pParse->nMem;
- int r2;
- r2 = sqlite3ExprCodeTarget(pParse, pExpr, r1);
- if( r1!=r2 ) sqlite3ReleaseTempReg(pParse, r1);
- pExpr->iColumn = pExpr->op;
- pExpr->op = TK_REGISTER;
- pExpr->iTable = r2;
- return 1;
- }
- return 0;
- }
- /*
- ** 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.
- */
- void sqlite3ExprCodeConstants(Parse *pParse, Expr *pExpr){
- walkExprTree(pExpr, evalConstExpr, pParse);
- }
- /*
- ** 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 /* Call sqlite3ExprHardCopy on each element if true */
- ){
- struct ExprList_item *pItem;
- int i, n;
- assert( pList!=0 || pParse->db->mallocFailed );
- if( pList==0 ){
- return 0;
- }
- assert( target>0 );
- n = pList->nExpr;
- for(pItem=pList->a, i=0; i<n; i++, pItem++){
- sqlite3ExprCode(pParse, pItem->pExpr, target+i);
- if( doHardCopy ) sqlite3ExprHardCopy(pParse, target, n);
- }
- 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 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( v==0 || pExpr==0 ) return;
- op = pExpr->op;
- switch( op ){
- case TK_AND: {
- int d2 = sqlite3VdbeMakeLabel(v);
- testcase( jumpIfNull==0 );
- testcase( pParse->disableColCache==0 );
- sqlite3ExprIfFalse(pParse, pExpr->pLeft, d2,jumpIfNull^SQLITE_JUMPIFNULL);
- pParse->disableColCache++;
- sqlite3ExprIfTrue(pParse, pExpr->pRight, dest, jumpIfNull);
- assert( pParse->disableColCache>0 );
- pParse->disableColCache--;
- sqlite3VdbeResolveLabel(v, d2);
- break;
- }
- case TK_OR: {
- testcase( jumpIfNull==0 );
- testcase( pParse->disableColCache==0 );
- sqlite3ExprIfTrue(pParse, pExpr->pLeft, dest, jumpIfNull);
- pParse->disableColCache++;
- sqlite3ExprIfTrue(pParse, pExpr->pRight, dest, jumpIfNull);
- assert( pParse->disableColCache>0 );
- pParse->disableColCache--;
- 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 );
- codeCompareOperands(pParse, pExpr->pLeft, &r1, ®Free1,
- pExpr->pRight, &r2, ®Free2);
- codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op,
- r1, r2, dest, jumpIfNull);
- 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, ®Free1);
- sqlite3VdbeAddOp2(v, op, r1, dest);
- testcase( regFree1==0 );
- break;
- }
- case TK_BETWEEN: {
- /* x BETWEEN y AND z
- **
- ** Is equivalent to
- **
- ** x>=y AND x<=z
- **
- ** Code it as such, taking care to do the common subexpression
- ** elementation of x.
- */
- Expr exprAnd;
- Expr compLeft;
- Expr compRight;
- Expr exprX;
- exprX = *pExpr->pLeft;
- exprAnd.op = TK_AND;
- exprAnd.pLeft = &compLeft;
- exprAnd.pRight = &compRight;
- compLeft.op = TK_GE;
- compLeft.pLeft = &exprX;
- compLeft.pRight = pExpr->pList->a[0].pExpr;
- compRight.op = TK_LE;
- compRight.pLeft = &exprX;
- compRight.pRight = pExpr->pList->a[1].pExpr;
- exprX.iTable = sqlite3ExprCodeTemp(pParse, &exprX, ®Free1);
- testcase( regFree1==0 );
- exprX.op = TK_REGISTER;
- testcase( jumpIfNull==0 );
- sqlite3ExprIfTrue(pParse, &exprAnd, dest, jumpIfNull);
- break;
- }
- default: {
- r1 = sqlite3ExprCodeTemp(pParse, pExpr, ®Free1);
- 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( 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: {
- testcase( jumpIfNull==0 );
- testcase( pParse->disableColCache==0 );
- sqlite3ExprIfFalse(pParse, pExpr->pLeft, dest, jumpIfNull);
- pParse->disableColCache++;
- sqlite3ExprIfFalse(pParse, pExpr->pRight, dest, jumpIfNull);
- assert( pParse->disableColCache>0 );
- pParse->disableColCache--;
- break;
- }
- case TK_OR: {
- int d2 = sqlite3VdbeMakeLabel(v);
- testcase( jumpIfNull==0 );
- testcase( pParse->disableColCache==0 );
- sqlite3ExprIfTrue(pParse, pExpr->pLeft, d2, jumpIfNull^SQLITE_JUMPIFNULL);
- pParse->disableColCache++;
- sqlite3ExprIfFalse(pParse, pExpr->pRight, dest, jumpIfNull);
- assert( pParse->disableColCache>0 );
- pParse->disableColCache--;
- 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: {
- 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 );
- codeCompareOperands(pParse, pExpr->pLeft, &r1, ®Free1,
- pExpr->pRight, &r2, ®Free2);
- codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op,
- r1, r2, dest, jumpIfNull);
- 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, ®Free1);
- sqlite3VdbeAddOp2(v, op, r1, dest);
- testcase( regFree1==0 );
- break;
- }
- case TK_BETWEEN: {
- /* x BETWEEN y AND z
- **
- ** Is equivalent to
- **
- ** x>=y AND x<=z
- **
- ** Code it as such, taking care to do the common subexpression
- ** elementation of x.
- */
- Expr exprAnd;
- Expr compLeft;
- Expr compRight;
- Expr exprX;
- exprX = *pExpr->pLeft;
- exprAnd.op = TK_AND;
- exprAnd.pLeft = &compLeft;
- exprAnd.pRight = &compRight;
- compLeft.op = TK_GE;
- compLeft.pLeft = &exprX;
- compLeft.pRight = pExpr->pList->a[0].pExpr;
- compRight.op = TK_LE;
- compRight.pLeft = &exprX;
- compRight.pRight = pExpr->pList->a[1].pExpr;
- exprX.iTable = sqlite3ExprCodeTemp(pParse, &exprX, ®Free1);
- testcase( regFree1==0 );
- exprX.op = TK_REGISTER;
- testcase( jumpIfNull==0 );
- sqlite3ExprIfFalse(pParse, &exprAnd, dest, jumpIfNull);
- break;
- }
- default: {
- r1 = sqlite3ExprCodeTemp(pParse, pExpr, ®Free1);
- 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 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(sqlite3 *db, AggInfo *pInfo){
- int i;
- pInfo->aCol = sqlite3ArrayAllocate(
- db,
- 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(sqlite3 *db, AggInfo *pInfo){
- int i;
- pInfo->aFunc = sqlite3ArrayAllocate(
- db,
- 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(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.
- */
- 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(pParse->db, 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().
- */
- void sqlite3ExprAnalyzeAggregates(NameContext *pNC, Expr *pExpr){
- walkExprTree(pExpr, analyzeAggregate, pNC);
- }
- /*
- ** Call sqlite3ExprAnalyzeAggregates() for every expression in an
- ** expression list. Return the number of errors.
- **
- ** If an error is found, the analysis is cut short.
- */
- void sqlite3ExprAnalyzeAggList(NameContext *pNC, ExprList *pList){
- struct ExprList_item *pItem;
- int i;
- if( pList ){
- for(pItem=pList->a, i=0; i<pList->nExpr; i++, pItem++){
- sqlite3ExprAnalyzeAggregates(pNC, pItem->pExpr);
- }
- }
- }
- /*
- ** Allocate or deallocate temporary use registers during code generation.
- */
- int sqlite3GetTempReg(Parse *pParse){
- int i, r;
- if( pParse->nTempReg==0 ){
- return ++pParse->nMem;
- }
- for(i=0; i<pParse->nTempReg; i++){
- r = pParse->aTempReg[i];
- if( usedAsColumnCache(pParse, r, r) ) continue;
- }
- if( i>=pParse->nTempReg ){
- return ++pParse->nMem;
- }
- while( i<pParse->nTempReg-1 ){
- pParse->aTempReg[i] = pParse->aTempReg[i+1];
- }
- pParse->nTempReg--;
- return r;
- }
- void sqlite3ReleaseTempReg(Parse *pParse, int iReg){
- if( iReg && pParse->nTempReg<ArraySize(pParse->aTempReg) ){
- pParse->aTempReg[pParse->nTempReg++] = iReg;
- }
- }
- /*
- ** Allocate or deallocate a block of nReg consecutive registers
- */
- int sqlite3GetTempRange(Parse *pParse, int nReg){
- int i, n;
- i = pParse->iRangeReg;
- n = pParse->nRangeReg;
- if( nReg<=n && !usedAsColumnCache(pParse, i, i+n-1) ){
- pParse->iRangeReg += nReg;
- pParse->nRangeReg -= nReg;
- }else{
- i = pParse->nMem+1;
- pParse->nMem += nReg;
- }
- return i;
- }
- void sqlite3ReleaseTempRange(Parse *pParse, int iReg, int nReg){
- if( nReg>pParse->nRangeReg ){
- pParse->nRangeReg = nReg;
- pParse->iRangeReg = iReg;
- }
- }