--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/persistentstorage/sql/SQLite/expr.c Fri Jan 22 11:06:30 2010 +0200
@@ -0,0 +1,3586 @@
+/*
+** 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 1.387 2008/07/28 19:34:53 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;
+ sqlite3 *db = pParse->db;
+ zColl = sqlite3NameFromToken(db, pName);
+ if( pExpr && zColl ){
+ pColl = sqlite3LocateCollSeq(pParse, zColl, -1);
+ if( pColl ){
+ pExpr->pColl = pColl;
+ pExpr->flags |= EP_ExpCollate;
+ }
+ }
+ sqlite3DbFree(db, zColl);
+ return pExpr;
+}
+
+/*
+** Return the default collation sequence for the expression pExpr. If
+** there is no default collation type, return 0.
+*/
+CollSeq *sqlite3ExprCollSeq(Parse *pParse, Expr *pExpr){
+ CollSeq *pColl = 0;
+ 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)!=SQLITE_AFF_NONE ){
+ sqlite3ExprCacheAffinityChange(pParse, in1, 1);
+ sqlite3ExprCacheAffinityChange(pParse, in2, 1);
+ }
+ return addr;
+}
+
+#if SQLITE_MAX_EXPR_DEPTH>0
+/*
+** Check that argument nHeight is less than or equal to the maximum
+** expression depth allowed. If it is not, leave an error message in
+** pParse.
+*/
+static int checkExprHeight(Parse *pParse, int nHeight){
+ int rc = SQLITE_OK;
+ int mxHeight = pParse->db->aLimit[SQLITE_LIMIT_EXPR_DEPTH];
+ if( nHeight>mxHeight ){
+ sqlite3ErrorMsg(pParse,
+ "Expression tree is too large (maximum depth %d)", mxHeight
+ );
+ rc = SQLITE_ERROR;
+ }
+ return rc;
+}
+
+/* The following three functions, heightOfExpr(), heightOfExprList()
+** and heightOfSelect(), are used to determine the maximum height
+** of any expression tree referenced by the structure passed as the
+** first argument.
+**
+** If this maximum height is greater than the current value pointed
+** to by pnHeight, the second parameter, then set *pnHeight to that
+** value.
+*/
+static void heightOfExpr(Expr *p, int *pnHeight){
+ if( p ){
+ if( p->nHeight>*pnHeight ){
+ *pnHeight = p->nHeight;
+ }
+ }
+}
+static void heightOfExprList(ExprList *p, int *pnHeight){
+ if( p ){
+ int i;
+ for(i=0; i<p->nExpr; i++){
+ heightOfExpr(p->a[i].pExpr, pnHeight);
+ }
+ }
+}
+static void heightOfSelect(Select *p, int *pnHeight){
+ if( p ){
+ heightOfExpr(p->pWhere, pnHeight);
+ heightOfExpr(p->pHaving, pnHeight);
+ heightOfExpr(p->pLimit, pnHeight);
+ heightOfExpr(p->pOffset, pnHeight);
+ heightOfExprList(p->pEList, pnHeight);
+ heightOfExprList(p->pGroupBy, pnHeight);
+ heightOfExprList(p->pOrderBy, pnHeight);
+ heightOfSelect(p->pPrior, pnHeight);
+ }
+}
+
+/*
+** Set the Expr.nHeight variable in the structure passed as an
+** argument. An expression with no children, Expr.pList or
+** Expr.pSelect member has a height of 1. Any other expression
+** has a height equal to the maximum height of any other
+** referenced Expr plus one.
+*/
+static void exprSetHeight(Expr *p){
+ int nHeight = 0;
+ heightOfExpr(p->pLeft, &nHeight);
+ heightOfExpr(p->pRight, &nHeight);
+ heightOfExprList(p->pList, &nHeight);
+ heightOfSelect(p->pSelect, &nHeight);
+ p->nHeight = nHeight + 1;
+}
+
+/*
+** Set the Expr.nHeight variable using the exprSetHeight() function. If
+** the height is greater than the maximum allowed expression depth,
+** leave an error in pParse.
+*/
+void sqlite3ExprSetHeight(Parse *pParse, Expr *p){
+ exprSetHeight(p);
+ checkExprHeight(pParse, p->nHeight);
+}
+
+/*
+** Return the maximum height of any expression tree referenced
+** by the select statement passed as an argument.
+*/
+int sqlite3SelectExprHeight(Select *p){
+ int nHeight = 0;
+ heightOfSelect(p, &nHeight);
+ return nHeight;
+}
+#else
+ #define checkExprHeight(x,y)
+ #define exprSetHeight(y)
+#endif /* SQLITE_MAX_EXPR_DEPTH>0 */
+
+/*
+** 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;
+ pNew = sqlite3DbMallocZero(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(db, pLeft);
+ sqlite3ExprDelete(db, pRight);
+ return 0;
+ }
+ pNew->op = op;
+ pNew->pLeft = pLeft;
+ pNew->pRight = pRight;
+ pNew->iAgg = -1;
+ pNew->span.z = (u8*)"";
+ if( pToken ){
+ assert( pToken->dyn==0 );
+ pNew->span = pNew->token = *pToken;
+ }else if( pLeft ){
+ if( pRight ){
+ if( pRight->span.dyn==0 && pLeft->span.dyn==0 ){
+ 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;
+ }
+ }
+
+ exprSetHeight(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 */
+){
+ Expr *p = sqlite3Expr(pParse->db, op, pLeft, pRight, pToken);
+ if( p ){
+ checkExprHeight(pParse, p->nHeight);
+ }
+ return p;
+}
+
+/*
+** 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. Both tokens must be pointing
+** at the same string.
+*/
+void sqlite3ExprSpan(Expr *pExpr, Token *pLeft, Token *pRight){
+ assert( pRight!=0 );
+ assert( pLeft!=0 );
+ if( pExpr ){
+ pExpr->span.z = pLeft->z;
+ pExpr->span.n = pRight->n + (pRight->z - pLeft->z);
+ }
+}
+
+/*
+** Construct a new expression node for a function with multiple
+** arguments.
+*/
+Expr *sqlite3ExprFunction(Parse *pParse, ExprList *pList, Token *pToken){
+ Expr *pNew;
+ sqlite3 *db = pParse->db;
+ assert( pToken );
+ pNew = sqlite3DbMallocZero(db, sizeof(Expr) );
+ if( pNew==0 ){
+ sqlite3ExprListDelete(db, 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(pParse, pNew);
+ return pNew;
+}
+
+/*
+** Assign a variable number to an expression that encodes a wildcard
+** in the original SQL statement.
+**
+** Wildcards consisting of a single "?" are assigned the next sequential
+** variable number.
+**
+** Wildcards of the form "?nnn" are assigned the number "nnn". We make
+** sure "nnn" is not too be to avoid a denial of service attack when
+** the SQL statement comes from an external source.
+**
+** Wildcards of the form ":aaa" 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(sqlite3 *db, Expr *p){
+ if( p==0 ) return;
+ if( p->span.dyn ) sqlite3DbFree(db, (char*)p->span.z);
+ if( p->token.dyn ) sqlite3DbFree(db, (char*)p->token.z);
+ sqlite3ExprDelete(db, p->pLeft);
+ sqlite3ExprDelete(db, p->pRight);
+ sqlite3ExprListDelete(db, p->pList);
+ sqlite3SelectDelete(db, p->pSelect);
+ sqlite3DbFree(db, 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 ) sqlite3DbFree(db, (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 ){
+ sqlite3DbFree(db, 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 ){
+ sqlite3DbFree(db, 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 = 0;
+ pNew->iOffset = 0;
+ 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(db, pExpr);
+ sqlite3ExprListDelete(db, 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);
+ }
+}
+
+/*
+** Delete an entire expression list.
+*/
+void sqlite3ExprListDelete(sqlite3 *db, ExprList *pList){
+ int i;
+ struct ExprList_item *pItem;
+ if( pList==0 ) return;
+ assert( pList->a!=0 || (pList->nExpr==0 && pList->nAlloc==0) );
+ assert( pList->nExpr<=pList->nAlloc );
+ for(pItem=pList->a, i=0; i<pList->nExpr; i++, pItem++){
+ sqlite3ExprDelete(db, pItem->pExpr);
+ sqlite3DbFree(db, pItem->zName);
+ }
+ sqlite3DbFree(db, pList->a);
+ sqlite3DbFree(db, 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){
+ int rc = 0;
+ if( p->flags & EP_IntValue ){
+ *pValue = p->iTable;
+ return 1;
+ }
+ switch( p->op ){
+ case TK_INTEGER: {
+ rc = sqlite3GetInt32((char*)p->token.z, pValue);
+ break;
+ }
+ case TK_UPLUS: {
+ rc = sqlite3ExprIsInteger(p->pLeft, pValue);
+ break;
+ }
+ case TK_UMINUS: {
+ int v;
+ if( sqlite3ExprIsInteger(p->pLeft, &v) ){
+ *pValue = -v;
+ rc = 1;
+ }
+ break;
+ }
+ default: break;
+ }
+ if( rc ){
+ p->op = TK_INTEGER;
+ p->flags |= EP_IntValue;
+ p->iTable = *pValue;
+ }
+ return rc;
+}
+
+/*
+** 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);
+ sqlite3DbFree(db, zCol);
+ return 2;
+ }
+ pDup = sqlite3ExprDup(db, pOrig);
+ if( pExpr->flags & EP_ExpCollate ){
+ pDup->pColl = pExpr->pColl;
+ pDup->flags |= EP_ExpCollate;
+ }
+ if( pExpr->span.dyn ) sqlite3DbFree(db, (char*)pExpr->span.z);
+ if( pExpr->token.dyn ) sqlite3DbFree(db, (char*)pExpr->token.z);
+ memcpy(pExpr, pDup, sizeof(*pExpr));
+ sqlite3DbFree(db, 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]=='"' ){
+ sqlite3DbFree(db, 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
+ */
+ sqlite3DbFree(db, zDb);
+ sqlite3DbFree(db, zTab);
+ sqlite3ExprDelete(db, pExpr->pLeft);
+ pExpr->pLeft = 0;
+ sqlite3ExprDelete(db, pExpr->pRight);
+ pExpr->pRight = 0;
+ pExpr->op = TK_COLUMN;
+lookupname_end_2:
+ sqlite3DbFree(db, 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
+ {
+ if( checkExprHeight(pNC->pParse, pExpr->nHeight + pNC->pParse->nHeight) ){
+ 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
+
+/*
+** Return true if the IN operator optimization is enabled and
+** the SELECT statement p exists and 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.
+*/
+#ifndef SQLITE_OMIT_SUBQUERY
+static int isCandidateForInOpt(Select *p){
+ SrcList *pSrc;
+ ExprList *pEList;
+ Table *pTab;
+ if( !sqlite3_enable_in_opt ) return 0; /* IN optimization must be enabled */
+ if( p==0 ) return 0; /* right-hand side of IN is SELECT */
+ if( p->pPrior ) return 0; /* Not a compound SELECT */
+ if( p->isDistinct ) return 0; /* No DISTINCT keyword */
+ if( p->isAgg ) return 0; /* Contains no aggregate functions */
+ if( p->pGroupBy ) return 0; /* Has no GROUP BY clause */
+ if( p->pLimit ) return 0; /* Has no LIMIT clause */
+ if( p->pOffset ) return 0;
+ if( p->pWhere ) return 0; /* Has no WHERE clause */
+ pSrc = p->pSrc;
+ if( pSrc==0 ) return 0; /* A single table in the FROM clause */
+ if( pSrc->nSrc!=1 ) return 0;
+ if( pSrc->a[0].pSelect ) return 0; /* FROM clause is not a subquery */
+ pTab = pSrc->a[0].pTab;
+ if( pTab==0 ) return 0;
+ if( pTab->pSelect ) return 0; /* FROM clause is not a view */
+ if( IsVirtual(pTab) ) return 0; /* FROM clause not a virtual table */
+ pEList = p->pEList;
+ if( pEList->nExpr!=1 ) return 0; /* One column in the result set */
+ if( pEList->a[0].pExpr->op!=TK_COLUMN ) return 0; /* Result is a column */
+ return 1;
+}
+#endif /* SQLITE_OMIT_SUBQUERY */
+
+/*
+** 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 prNotFound parameter is 0, 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.
+**
+** If the prNotFound parameter is not 0, then 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.
+**
+** When the structure is being used for set membership tests, the user
+** needs to know whether or not the structure contains an SQL NULL
+** value in order to correctly evaluate expressions like "X IN (Y, Z)".
+** If there is a chance that the structure may contain a NULL value at
+** runtime, then a register is allocated and the register number written
+** to *prNotFound. If there is no chance that the structure contains a
+** NULL value, then *prNotFound is left unchanged.
+**
+** If a register is allocated and its location stored in *prNotFound, then
+** its initial value is NULL. If the structure does not remain constant
+** for the duration of the query (i.e. the set is a correlated sub-select),
+** the value of the allocated register is reset to NULL each time the
+** structure is repopulated. This allows the caller to use vdbe code
+** equivalent to the following:
+**
+** if( register==NULL ){
+** has_null = <test if data structure contains null>
+** register = 1
+** }
+**
+** in order to avoid running the <test if data structure contains null>
+** test more often than is necessary.
+*/
+#ifndef SQLITE_OMIT_SUBQUERY
+int sqlite3FindInIndex(Parse *pParse, Expr *pX, int *prNotFound){
+ Select *p;
+ int eType = 0;
+ int iTab = pParse->nTab++;
+ int mustBeUnique = !prNotFound;
+
+ /* 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.
+ */
+ p = pX->pSelect;
+ if( isCandidateForInOpt(p) ){
+ 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( prNotFound && !pTab->aCol[iCol].notNull ){
+ *prNotFound = ++pParse->nMem;
+ }
+ }
+ }
+ }
+ }
+
+ if( eType==0 ){
+ int rMayHaveNull = 0;
+ if( prNotFound ){
+ *prNotFound = rMayHaveNull = ++pParse->nMem;
+ }
+ sqlite3CodeSubselect(pParse, pX, rMayHaveNull);
+ 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 rMayHaveNull){
+ 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 */
+
+ if( rMayHaveNull ){
+ sqlite3VdbeAddOp2(v, OP_Null, 0, rMayHaveNull);
+ }
+
+ 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) ){
+ 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, r3;
+
+ 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++;
+ r3 = sqlite3ExprCodeTarget(pParse, pE2, r1);
+ assert( pParse->disableColCache>0 );
+ pParse->disableColCache--;
+ sqlite3VdbeAddOp4(v, OP_MakeRecord, r3, 1, r2, &affinity, 1);
+ sqlite3ExprCacheAffinityChange(pParse, r3, 1);
+ sqlite3VdbeAddOp2(v, OP_IdxInsert, pExpr->iTable, r2);
+ }
+ sqlite3ReleaseTempReg(pParse, r1);
+ sqlite3ReleaseTempReg(pParse, r2);
+ }
+ 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(pParse->db, pSel->pLimit);
+ pSel->pLimit = sqlite3PExpr(pParse, TK_INTEGER, 0, 0, &one);
+ if( sqlite3Select(pParse, pSel, &dest, 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( sqlite3IsNaN(value) ){
+ sqlite3VdbeAddOp2(v, OP_Null, 0, iMem);
+ }else{
+ 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, Expr *pExpr, int negFlag, int iMem){
+ const char *z;
+ if( pExpr->flags & EP_IntValue ){
+ int i = pExpr->iTable;
+ if( negFlag ) i = -i;
+ sqlite3VdbeAddOp2(v, OP_Integer, i, iMem);
+ }else if( (z = (char*)pExpr->token.z)!=0 ){
+ int i;
+ int n = pExpr->token.n;
+ 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 move content from registers iFrom...iFrom+nReg-1
+** over to iTo..iTo+nReg-1. Keep the column cache up-to-date.
+*/
+void sqlite3ExprCodeMove(Parse *pParse, int iFrom, int iTo, int nReg){
+ int i;
+ if( iFrom==iTo ) return;
+ sqlite3VdbeAddOp3(pParse->pVdbe, OP_Move, iFrom, iTo, nReg);
+ for(i=0; i<pParse->nColCache; i++){
+ int x = pParse->aColCache[i].iReg;
+ if( x>=iFrom && x<iFrom+nReg ){
+ pParse->aColCache[i].iReg += iTo-iFrom;
+ }
+ }
+}
+
+/*
+** Generate code to copy content from registers iFrom...iFrom+nReg-1
+** over to iTo..iTo+nReg-1.
+*/
+void sqlite3ExprCodeCopy(Parse *pParse, int iFrom, int iTo, int nReg){
+ int i;
+ if( iFrom==iTo ) return;
+ for(i=0; i<nReg; i++){
+ sqlite3VdbeAddOp2(pParse->pVdbe, OP_Copy, iFrom+i, iTo+i);
+ }
+}
+
+/*
+** 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);
+ assert( pOp || pParse->db->mallocFailed );
+ if( pOp && 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, pExpr, 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 ){
+ if( pLeft->op==TK_FLOAT ){
+ codeReal(v, (char*)pLeft->token.z, pLeft->token.n, 1, target);
+ }else{
+ codeInteger(v, pLeft, 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, 0);
+ }
+ inReg = pExpr->iColumn;
+ break;
+ }
+ case TK_IN: {
+ int rNotFound = 0;
+ int rMayHaveNull = 0;
+ int j2, j3, j4, j5;
+ char affinity;
+ int eType;
+
+ VdbeNoopComment((v, "begin IN expr r%d", target));
+ eType = sqlite3FindInIndex(pParse, pExpr, &rMayHaveNull);
+ if( rMayHaveNull ){
+ rNotFound = ++pParse->nMem;
+ }
+
+ /* Figure out the affinity to use to create a key from the results
+ ** of the expression. affinityStr stores a static string suitable for
+ ** P4 of OP_MakeRecord.
+ */
+ affinity = comparisonAffinity(pExpr);
+
+
+ /* Code the <expr> from "<expr> IN (...)". The temporary table
+ ** pExpr->iTable contains the values that make up the (...) set.
+ */
+ pParse->disableColCache++;
+ sqlite3ExprCode(pParse, pExpr->pLeft, target);
+ pParse->disableColCache--;
+ j2 = sqlite3VdbeAddOp1(v, OP_IsNull, target);
+ if( eType==IN_INDEX_ROWID ){
+ j3 = sqlite3VdbeAddOp1(v, OP_MustBeInt, target);
+ j4 = sqlite3VdbeAddOp3(v, OP_NotExists, pExpr->iTable, 0, target);
+ sqlite3VdbeAddOp2(v, OP_Integer, 1, target);
+ j5 = sqlite3VdbeAddOp0(v, OP_Goto);
+ sqlite3VdbeJumpHere(v, j3);
+ sqlite3VdbeJumpHere(v, j4);
+ sqlite3VdbeAddOp2(v, OP_Integer, 0, target);
+ }else{
+ r2 = regFree2 = sqlite3GetTempReg(pParse);
+
+ /* Create a record and test for set membership. If the set contains
+ ** the value, then jump to the end of the test code. The target
+ ** register still contains the true (1) value written to it earlier.
+ */
+ sqlite3VdbeAddOp4(v, OP_MakeRecord, target, 1, r2, &affinity, 1);
+ sqlite3VdbeAddOp2(v, OP_Integer, 1, target);
+ j5 = sqlite3VdbeAddOp3(v, OP_Found, pExpr->iTable, 0, r2);
+
+ /* If the set membership test fails, then the result of the
+ ** "x IN (...)" expression must be either 0 or NULL. If the set
+ ** contains no NULL values, then the result is 0. If the set
+ ** contains one or more NULL values, then the result of the
+ ** expression is also NULL.
+ */
+ if( rNotFound==0 ){
+ /* This branch runs if it is known at compile time (now) that
+ ** the set contains no NULL values. This happens as the result
+ ** of a "NOT NULL" constraint in the database schema. No need
+ ** to test the data structure at runtime in this case.
+ */
+ sqlite3VdbeAddOp2(v, OP_Integer, 0, target);
+ }else{
+ /* This block populates the rNotFound register with either NULL
+ ** or 0 (an integer value). If the data structure contains one
+ ** or more NULLs, then set rNotFound to NULL. Otherwise, set it
+ ** to 0. If register rMayHaveNull is already set to some value
+ ** other than NULL, then the test has already been run and
+ ** rNotFound is already populated.
+ */
+ static const char nullRecord[] = { 0x02, 0x00 };
+ j3 = sqlite3VdbeAddOp1(v, OP_NotNull, rMayHaveNull);
+ sqlite3VdbeAddOp2(v, OP_Null, 0, rNotFound);
+ sqlite3VdbeAddOp4(v, OP_Blob, 2, rMayHaveNull, 0,
+ nullRecord, P4_STATIC);
+ j4 = sqlite3VdbeAddOp3(v, OP_Found, pExpr->iTable, 0, rMayHaveNull);
+ sqlite3VdbeAddOp2(v, OP_Integer, 0, rNotFound);
+ sqlite3VdbeJumpHere(v, j4);
+ sqlite3VdbeJumpHere(v, j3);
+
+ /* Copy the value of register rNotFound (which is either NULL or 0)
+ ** into the target register. This will be the result of the
+ ** expression.
+ */
+ sqlite3VdbeAddOp2(v, OP_Copy, rNotFound, target);
+ }
+ }
+ sqlite3VdbeJumpHere(v, j2);
+ sqlite3VdbeJumpHere(v, j5);
+ VdbeComment((v, "end IN expr r%d", target));
+ 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){
+ if( pParse->nTempReg==0 ){
+ return ++pParse->nMem;
+ }
+ return pParse->aTempReg[--pParse->nTempReg];
+}
+void sqlite3ReleaseTempReg(Parse *pParse, int iReg){
+ if( iReg && pParse->nTempReg<ArraySize(pParse->aTempReg) ){
+ sqlite3ExprWritableRegister(pParse, iReg, iReg);
+ 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;
+ }
+}