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- /*
- ** 2001 September 15
- **
- ** The author disclaims copyright to this source code. In place of
- ** a legal notice, here is a blessing:
- **
- ** May you do good and not evil.
- ** May you find forgiveness for yourself and forgive others.
- ** May you share freely, never taking more than you give.
- **
- *************************************************************************
- ** This file contains routines used for analyzing expressions and
- ** for generating VDBE code that evaluates expressions in SQLite.
- */
- #include "sqliteInt.h"
- /*
- ** Return the 'affinity' of the expression pExpr if any.
- **
- ** If pExpr is a column, a reference to a column via an 'AS' alias,
- ** or a sub-select with a column as the return value, then the
- ** affinity of that column is returned. Otherwise, 0x00 is returned,
- ** indicating no affinity for the expression.
- **
- ** i.e. the WHERE clause expresssions in the following statements all
- ** have an affinity:
- **
- ** CREATE TABLE t1(a);
- ** SELECT * FROM t1 WHERE a;
- ** SELECT a AS b FROM t1 WHERE b;
- ** SELECT * FROM t1 WHERE (select a from t1);
- */
- char sqlite3ExprAffinity(Expr *pExpr){
- int op;
- pExpr = sqlite3ExprSkipCollate(pExpr);
- op = pExpr->op;
- if( op==TK_SELECT ){
- assert( pExpr->flags&EP_xIsSelect );
- return sqlite3ExprAffinity(pExpr->x.pSelect->pEList->a[0].pExpr);
- }
- #ifndef SQLITE_OMIT_CAST
- if( op==TK_CAST ){
- assert( !ExprHasProperty(pExpr, EP_IntValue) );
- return sqlite3AffinityType(pExpr->u.zToken, 0);
- }
- #endif
- if( (op==TK_AGG_COLUMN || op==TK_COLUMN || op==TK_REGISTER)
- && pExpr->pTab!=0
- ){
- /* op==TK_REGISTER && pExpr->pTab!=0 happens when pExpr was originally
- ** a TK_COLUMN but was previously evaluated and cached in a register */
- int j = pExpr->iColumn;
- if( j<0 ) return SQLITE_AFF_INTEGER;
- assert( pExpr->pTab && j<pExpr->pTab->nCol );
- return pExpr->pTab->aCol[j].affinity;
- }
- return pExpr->affinity;
- }
- /*
- ** Set the collating sequence for expression pExpr to be the collating
- ** sequence named by pToken. Return a pointer to a new Expr node that
- ** implements the COLLATE operator.
- **
- ** If a memory allocation error occurs, that fact is recorded in pParse->db
- ** and the pExpr parameter is returned unchanged.
- */
- Expr *sqlite3ExprAddCollateToken(Parse *pParse, Expr *pExpr, Token *pCollName){
- if( pCollName->n>0 ){
- Expr *pNew = sqlite3ExprAlloc(pParse->db, TK_COLLATE, pCollName, 1);
- if( pNew ){
- pNew->pLeft = pExpr;
- pNew->flags |= EP_Collate|EP_Skip;
- pExpr = pNew;
- }
- }
- return pExpr;
- }
- Expr *sqlite3ExprAddCollateString(Parse *pParse, Expr *pExpr, const char *zC){
- Token s;
- assert( zC!=0 );
- s.z = zC;
- s.n = sqlite3Strlen30(s.z);
- return sqlite3ExprAddCollateToken(pParse, pExpr, &s);
- }
- /*
- ** Skip over any TK_COLLATE or TK_AS operators and any unlikely()
- ** or likelihood() function at the root of an expression.
- */
- Expr *sqlite3ExprSkipCollate(Expr *pExpr){
- while( pExpr && ExprHasProperty(pExpr, EP_Skip) ){
- if( ExprHasProperty(pExpr, EP_Unlikely) ){
- assert( !ExprHasProperty(pExpr, EP_xIsSelect) );
- assert( pExpr->x.pList->nExpr>0 );
- assert( pExpr->op==TK_FUNCTION );
- pExpr = pExpr->x.pList->a[0].pExpr;
- }else{
- assert( pExpr->op==TK_COLLATE || pExpr->op==TK_AS );
- pExpr = pExpr->pLeft;
- }
- }
- return pExpr;
- }
- /*
- ** Return the collation sequence for the expression pExpr. If
- ** there is no defined collating sequence, return NULL.
- **
- ** The collating sequence might be determined by a COLLATE operator
- ** or by the presence of a column with a defined collating sequence.
- ** COLLATE operators take first precedence. Left operands take
- ** precedence over right operands.
- */
- CollSeq *sqlite3ExprCollSeq(Parse *pParse, Expr *pExpr){
- sqlite3 *db = pParse->db;
- CollSeq *pColl = 0;
- Expr *p = pExpr;
- while( p ){
- int op = p->op;
- if( op==TK_CAST || op==TK_UPLUS ){
- p = p->pLeft;
- continue;
- }
- if( op==TK_COLLATE || (op==TK_REGISTER && p->op2==TK_COLLATE) ){
- pColl = sqlite3GetCollSeq(pParse, ENC(db), 0, p->u.zToken);
- break;
- }
- if( p->pTab!=0
- && (op==TK_AGG_COLUMN || op==TK_COLUMN
- || op==TK_REGISTER || op==TK_TRIGGER)
- ){
- /* op==TK_REGISTER && p->pTab!=0 happens when pExpr was originally
- ** a TK_COLUMN but was previously evaluated and cached in a register */
- int j = p->iColumn;
- if( j>=0 ){
- const char *zColl = p->pTab->aCol[j].zColl;
- pColl = sqlite3FindCollSeq(db, ENC(db), zColl, 0);
- }
- break;
- }
- if( p->flags & EP_Collate ){
- if( ALWAYS(p->pLeft) && (p->pLeft->flags & EP_Collate)!=0 ){
- p = p->pLeft;
- }else{
- p = p->pRight;
- }
- }else{
- break;
- }
- }
- if( sqlite3CheckCollSeq(pParse, pColl) ){
- pColl = 0;
- }
- return pColl;
- }
- /*
- ** pExpr is an operand of a comparison operator. aff2 is the
- ** type affinity of the other operand. This routine returns the
- ** type affinity that should be used for the comparison operator.
- */
- char sqlite3CompareAffinity(Expr *pExpr, char aff2){
- char aff1 = sqlite3ExprAffinity(pExpr);
- if( aff1 && aff2 ){
- /* Both sides of the comparison are columns. If one has numeric
- ** affinity, use that. Otherwise use no affinity.
- */
- if( sqlite3IsNumericAffinity(aff1) || sqlite3IsNumericAffinity(aff2) ){
- return SQLITE_AFF_NUMERIC;
- }else{
- return SQLITE_AFF_NONE;
- }
- }else if( !aff1 && !aff2 ){
- /* Neither side of the comparison is a column. Compare the
- ** results directly.
- */
- return SQLITE_AFF_NONE;
- }else{
- /* One side is a column, the other is not. Use the columns affinity. */
- assert( aff1==0 || aff2==0 );
- return (aff1 + aff2);
- }
- }
- /*
- ** pExpr is a comparison operator. Return the type affinity that should
- ** be applied to both operands prior to doing the comparison.
- */
- static char comparisonAffinity(Expr *pExpr){
- char aff;
- assert( pExpr->op==TK_EQ || pExpr->op==TK_IN || pExpr->op==TK_LT ||
- pExpr->op==TK_GT || pExpr->op==TK_GE || pExpr->op==TK_LE ||
- pExpr->op==TK_NE || pExpr->op==TK_IS || pExpr->op==TK_ISNOT );
- assert( pExpr->pLeft );
- aff = sqlite3ExprAffinity(pExpr->pLeft);
- if( pExpr->pRight ){
- aff = sqlite3CompareAffinity(pExpr->pRight, aff);
- }else if( ExprHasProperty(pExpr, EP_xIsSelect) ){
- aff = sqlite3CompareAffinity(pExpr->x.pSelect->pEList->a[0].pExpr, aff);
- }else if( !aff ){
- aff = SQLITE_AFF_NONE;
- }
- return aff;
- }
- /*
- ** pExpr is a comparison expression, eg. '=', '<', IN(...) etc.
- ** idx_affinity is the affinity of an indexed column. Return true
- ** if the index with affinity idx_affinity may be used to implement
- ** the comparison in pExpr.
- */
- int sqlite3IndexAffinityOk(Expr *pExpr, char idx_affinity){
- char aff = comparisonAffinity(pExpr);
- switch( aff ){
- case SQLITE_AFF_NONE:
- return 1;
- case SQLITE_AFF_TEXT:
- return idx_affinity==SQLITE_AFF_TEXT;
- default:
- return sqlite3IsNumericAffinity(idx_affinity);
- }
- }
- /*
- ** Return the P5 value that should be used for a binary comparison
- ** opcode (OP_Eq, OP_Ge etc.) used to compare pExpr1 and pExpr2.
- */
- static u8 binaryCompareP5(Expr *pExpr1, Expr *pExpr2, int jumpIfNull){
- u8 aff = (char)sqlite3ExprAffinity(pExpr2);
- aff = (u8)sqlite3CompareAffinity(pExpr1, aff) | (u8)jumpIfNull;
- return aff;
- }
- /*
- ** Return a pointer to the collation sequence that should be used by
- ** a binary comparison operator comparing pLeft and pRight.
- **
- ** If the left hand expression has a collating sequence type, then it is
- ** used. Otherwise the collation sequence for the right hand expression
- ** is used, or the default (BINARY) if neither expression has a collating
- ** type.
- **
- ** Argument pRight (but not pLeft) may be a null pointer. In this case,
- ** it is not considered.
- */
- CollSeq *sqlite3BinaryCompareCollSeq(
- Parse *pParse,
- Expr *pLeft,
- Expr *pRight
- ){
- CollSeq *pColl;
- assert( pLeft );
- if( pLeft->flags & EP_Collate ){
- pColl = sqlite3ExprCollSeq(pParse, pLeft);
- }else if( pRight && (pRight->flags & EP_Collate)!=0 ){
- pColl = sqlite3ExprCollSeq(pParse, pRight);
- }else{
- pColl = sqlite3ExprCollSeq(pParse, pLeft);
- if( !pColl ){
- pColl = sqlite3ExprCollSeq(pParse, pRight);
- }
- }
- return pColl;
- }
- /*
- ** Generate code for a comparison operator.
- */
- static int codeCompare(
- Parse *pParse, /* The parsing (and code generating) context */
- Expr *pLeft, /* The left operand */
- Expr *pRight, /* The right operand */
- int opcode, /* The comparison opcode */
- int in1, int in2, /* Register holding operands */
- int dest, /* Jump here if true. */
- int jumpIfNull /* If true, jump if either operand is NULL */
- ){
- int p5;
- int addr;
- CollSeq *p4;
- p4 = sqlite3BinaryCompareCollSeq(pParse, pLeft, pRight);
- p5 = binaryCompareP5(pLeft, pRight, jumpIfNull);
- addr = sqlite3VdbeAddOp4(pParse->pVdbe, opcode, in2, dest, in1,
- (void*)p4, P4_COLLSEQ);
- sqlite3VdbeChangeP5(pParse->pVdbe, (u8)p5);
- return addr;
- }
- #if SQLITE_MAX_EXPR_DEPTH>0
- /*
- ** Check that argument nHeight is less than or equal to the maximum
- ** expression depth allowed. If it is not, leave an error message in
- ** pParse.
- */
- int sqlite3ExprCheckHeight(Parse *pParse, int nHeight){
- int rc = SQLITE_OK;
- int mxHeight = pParse->db->aLimit[SQLITE_LIMIT_EXPR_DEPTH];
- if( nHeight>mxHeight ){
- sqlite3ErrorMsg(pParse,
- "Expression tree is too large (maximum depth %d)", mxHeight
- );
- rc = SQLITE_ERROR;
- }
- return rc;
- }
- /* The following three functions, heightOfExpr(), heightOfExprList()
- ** and heightOfSelect(), are used to determine the maximum height
- ** of any expression tree referenced by the structure passed as the
- ** first argument.
- **
- ** If this maximum height is greater than the current value pointed
- ** to by pnHeight, the second parameter, then set *pnHeight to that
- ** value.
- */
- static void heightOfExpr(Expr *p, int *pnHeight){
- if( p ){
- if( p->nHeight>*pnHeight ){
- *pnHeight = p->nHeight;
- }
- }
- }
- static void heightOfExprList(ExprList *p, int *pnHeight){
- if( p ){
- int i;
- for(i=0; i<p->nExpr; i++){
- heightOfExpr(p->a[i].pExpr, pnHeight);
- }
- }
- }
- static void heightOfSelect(Select *p, int *pnHeight){
- if( p ){
- heightOfExpr(p->pWhere, pnHeight);
- heightOfExpr(p->pHaving, pnHeight);
- heightOfExpr(p->pLimit, pnHeight);
- heightOfExpr(p->pOffset, pnHeight);
- heightOfExprList(p->pEList, pnHeight);
- heightOfExprList(p->pGroupBy, pnHeight);
- heightOfExprList(p->pOrderBy, pnHeight);
- heightOfSelect(p->pPrior, pnHeight);
- }
- }
- /*
- ** Set the Expr.nHeight variable in the structure passed as an
- ** argument. An expression with no children, Expr.pList or
- ** Expr.pSelect member has a height of 1. Any other expression
- ** has a height equal to the maximum height of any other
- ** referenced Expr plus one.
- */
- static void exprSetHeight(Expr *p){
- int nHeight = 0;
- heightOfExpr(p->pLeft, &nHeight);
- heightOfExpr(p->pRight, &nHeight);
- if( ExprHasProperty(p, EP_xIsSelect) ){
- heightOfSelect(p->x.pSelect, &nHeight);
- }else{
- heightOfExprList(p->x.pList, &nHeight);
- }
- p->nHeight = nHeight + 1;
- }
- /*
- ** Set the Expr.nHeight variable using the exprSetHeight() function. If
- ** the height is greater than the maximum allowed expression depth,
- ** leave an error in pParse.
- */
- void sqlite3ExprSetHeight(Parse *pParse, Expr *p){
- exprSetHeight(p);
- sqlite3ExprCheckHeight(pParse, p->nHeight);
- }
- /*
- ** Return the maximum height of any expression tree referenced
- ** by the select statement passed as an argument.
- */
- int sqlite3SelectExprHeight(Select *p){
- int nHeight = 0;
- heightOfSelect(p, &nHeight);
- return nHeight;
- }
- #else
- #define exprSetHeight(y)
- #endif /* SQLITE_MAX_EXPR_DEPTH>0 */
- /*
- ** This routine is the core allocator for Expr nodes.
- **
- ** Construct a new expression node and return a pointer to it. Memory
- ** for this node and for the pToken argument is a single allocation
- ** obtained from sqlite3DbMalloc(). The calling function
- ** is responsible for making sure the node eventually gets freed.
- **
- ** If dequote is true, then the token (if it exists) is dequoted.
- ** If dequote is false, no dequoting is performance. The deQuote
- ** parameter is ignored if pToken is NULL or if the token does not
- ** appear to be quoted. If the quotes were of the form "..." (double-quotes)
- ** then the EP_DblQuoted flag is set on the expression node.
- **
- ** Special case: If op==TK_INTEGER and pToken points to a string that
- ** can be translated into a 32-bit integer, then the token is not
- ** stored in u.zToken. Instead, the integer values is written
- ** into u.iValue and the EP_IntValue flag is set. No extra storage
- ** is allocated to hold the integer text and the dequote flag is ignored.
- */
- Expr *sqlite3ExprAlloc(
- sqlite3 *db, /* Handle for sqlite3DbMallocZero() (may be null) */
- int op, /* Expression opcode */
- const Token *pToken, /* Token argument. Might be NULL */
- int dequote /* True to dequote */
- ){
- Expr *pNew;
- int nExtra = 0;
- int iValue = 0;
- if( pToken ){
- if( op!=TK_INTEGER || pToken->z==0
- || sqlite3GetInt32(pToken->z, &iValue)==0 ){
- nExtra = pToken->n+1;
- assert( iValue>=0 );
- }
- }
- pNew = sqlite3DbMallocZero(db, sizeof(Expr)+nExtra);
- if( pNew ){
- pNew->op = (u8)op;
- pNew->iAgg = -1;
- if( pToken ){
- if( nExtra==0 ){
- pNew->flags |= EP_IntValue;
- pNew->u.iValue = iValue;
- }else{
- int c;
- pNew->u.zToken = (char*)&pNew[1];
- assert( pToken->z!=0 || pToken->n==0 );
- if( pToken->n ) memcpy(pNew->u.zToken, pToken->z, pToken->n);
- pNew->u.zToken[pToken->n] = 0;
- if( dequote && nExtra>=3
- && ((c = pToken->z[0])=='\'' || c=='"' || c=='[' || c=='`') ){
- sqlite3Dequote(pNew->u.zToken);
- if( c=='"' ) pNew->flags |= EP_DblQuoted;
- }
- }
- }
- #if SQLITE_MAX_EXPR_DEPTH>0
- pNew->nHeight = 1;
- #endif
- }
- return pNew;
- }
- /*
- ** Allocate a new expression node from a zero-terminated token that has
- ** already been dequoted.
- */
- Expr *sqlite3Expr(
- sqlite3 *db, /* Handle for sqlite3DbMallocZero() (may be null) */
- int op, /* Expression opcode */
- const char *zToken /* Token argument. Might be NULL */
- ){
- Token x;
- x.z = zToken;
- x.n = zToken ? sqlite3Strlen30(zToken) : 0;
- return sqlite3ExprAlloc(db, op, &x, 0);
- }
- /*
- ** Attach subtrees pLeft and pRight to the Expr node pRoot.
- **
- ** If pRoot==NULL that means that a memory allocation error has occurred.
- ** In that case, delete the subtrees pLeft and pRight.
- */
- void sqlite3ExprAttachSubtrees(
- sqlite3 *db,
- Expr *pRoot,
- Expr *pLeft,
- Expr *pRight
- ){
- if( pRoot==0 ){
- assert( db->mallocFailed );
- sqlite3ExprDelete(db, pLeft);
- sqlite3ExprDelete(db, pRight);
- }else{
- if( pRight ){
- pRoot->pRight = pRight;
- pRoot->flags |= EP_Collate & pRight->flags;
- }
- if( pLeft ){
- pRoot->pLeft = pLeft;
- pRoot->flags |= EP_Collate & pLeft->flags;
- }
- exprSetHeight(pRoot);
- }
- }
- /*
- ** Allocate a Expr node which joins as many as two subtrees.
- **
- ** One or both of the subtrees can be NULL. Return a pointer to the new
- ** Expr node. Or, if an OOM error occurs, set pParse->db->mallocFailed,
- ** free the subtrees and return NULL.
- */
- Expr *sqlite3PExpr(
- Parse *pParse, /* Parsing context */
- int op, /* Expression opcode */
- Expr *pLeft, /* Left operand */
- Expr *pRight, /* Right operand */
- const Token *pToken /* Argument token */
- ){
- Expr *p;
- if( op==TK_AND && pLeft && pRight ){
- /* Take advantage of short-circuit false optimization for AND */
- p = sqlite3ExprAnd(pParse->db, pLeft, pRight);
- }else{
- p = sqlite3ExprAlloc(pParse->db, op, pToken, 1);
- sqlite3ExprAttachSubtrees(pParse->db, p, pLeft, pRight);
- }
- if( p ) {
- sqlite3ExprCheckHeight(pParse, p->nHeight);
- }
- return p;
- }
- /*
- ** Return 1 if an expression must be FALSE in all cases and 0 if the
- ** expression might be true. This is an optimization. If is OK to
- ** return 0 here even if the expression really is always false (a
- ** false negative). But it is a bug to return 1 if the expression
- ** might be true in some rare circumstances (a false positive.)
- **
- ** Note that if the expression is part of conditional for a
- ** LEFT JOIN, then we cannot determine at compile-time whether or not
- ** is it true or false, so always return 0.
- */
- static int exprAlwaysFalse(Expr *p){
- int v = 0;
- if( ExprHasProperty(p, EP_FromJoin) ) return 0;
- if( !sqlite3ExprIsInteger(p, &v) ) return 0;
- return v==0;
- }
- /*
- ** Join two expressions using an AND operator. If either expression is
- ** NULL, then just return the other expression.
- **
- ** If one side or the other of the AND is known to be false, then instead
- ** of returning an AND expression, just return a constant expression with
- ** a value of false.
- */
- Expr *sqlite3ExprAnd(sqlite3 *db, Expr *pLeft, Expr *pRight){
- if( pLeft==0 ){
- return pRight;
- }else if( pRight==0 ){
- return pLeft;
- }else if( exprAlwaysFalse(pLeft) || exprAlwaysFalse(pRight) ){
- sqlite3ExprDelete(db, pLeft);
- sqlite3ExprDelete(db, pRight);
- return sqlite3ExprAlloc(db, TK_INTEGER, &sqlite3IntTokens[0], 0);
- }else{
- Expr *pNew = sqlite3ExprAlloc(db, TK_AND, 0, 0);
- sqlite3ExprAttachSubtrees(db, pNew, pLeft, pRight);
- return pNew;
- }
- }
- /*
- ** Construct a new expression node for a function with multiple
- ** arguments.
- */
- Expr *sqlite3ExprFunction(Parse *pParse, ExprList *pList, Token *pToken){
- Expr *pNew;
- sqlite3 *db = pParse->db;
- assert( pToken );
- pNew = sqlite3ExprAlloc(db, TK_FUNCTION, pToken, 1);
- if( pNew==0 ){
- sqlite3ExprListDelete(db, pList); /* Avoid memory leak when malloc fails */
- return 0;
- }
- pNew->x.pList = pList;
- assert( !ExprHasProperty(pNew, EP_xIsSelect) );
- sqlite3ExprSetHeight(pParse, pNew);
- return pNew;
- }
- /*
- ** Assign a variable number to an expression that encodes a wildcard
- ** in the original SQL statement.
- **
- ** Wildcards consisting of a single "?" are assigned the next sequential
- ** variable number.
- **
- ** Wildcards of the form "?nnn" are assigned the number "nnn". We make
- ** sure "nnn" is not too be to avoid a denial of service attack when
- ** the SQL statement comes from an external source.
- **
- ** Wildcards of the form ":aaa", "@aaa", or "$aaa" are assigned the same number
- ** as the previous instance of the same wildcard. Or if this is the first
- ** instance of the wildcard, the next sequenial variable number is
- ** assigned.
- */
- void sqlite3ExprAssignVarNumber(Parse *pParse, Expr *pExpr){
- sqlite3 *db = pParse->db;
- const char *z;
- if( pExpr==0 ) return;
- assert( !ExprHasProperty(pExpr, EP_IntValue|EP_Reduced|EP_TokenOnly) );
- z = pExpr->u.zToken;
- assert( z!=0 );
- assert( z[0]!=0 );
- if( z[1]==0 ){
- /* Wildcard of the form "?". Assign the next variable number */
- assert( z[0]=='?' );
- pExpr->iColumn = (ynVar)(++pParse->nVar);
- }else{
- ynVar x = 0;
- u32 n = sqlite3Strlen30(z);
- if( z[0]=='?' ){
- /* Wildcard of the form "?nnn". Convert "nnn" to an integer and
- ** use it as the variable number */
- i64 i;
- int bOk = 0==sqlite3Atoi64(&z[1], &i, n-1, SQLITE_UTF8);
- pExpr->iColumn = x = (ynVar)i;
- testcase( i==0 );
- testcase( i==1 );
- testcase( i==db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER]-1 );
- testcase( i==db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER] );
- if( bOk==0 || i<1 || i>db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER] ){
- sqlite3ErrorMsg(pParse, "variable number must be between ?1 and ?%d",
- db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER]);
- x = 0;
- }
- if( i>pParse->nVar ){
- pParse->nVar = (int)i;
- }
- }else{
- /* Wildcards like ":aaa", "$aaa" or "@aaa". Reuse the same variable
- ** number as the prior appearance of the same name, or if the name
- ** has never appeared before, reuse the same variable number
- */
- ynVar i;
- for(i=0; i<pParse->nzVar; i++){
- if( pParse->azVar[i] && strcmp(pParse->azVar[i],z)==0 ){
- pExpr->iColumn = x = (ynVar)i+1;
- break;
- }
- }
- if( x==0 ) x = pExpr->iColumn = (ynVar)(++pParse->nVar);
- }
- if( x>0 ){
- if( x>pParse->nzVar ){
- char **a;
- a = sqlite3DbRealloc(db, pParse->azVar, x*sizeof(a[0]));
- if( a==0 ) return; /* Error reported through db->mallocFailed */
- pParse->azVar = a;
- memset(&a[pParse->nzVar], 0, (x-pParse->nzVar)*sizeof(a[0]));
- pParse->nzVar = x;
- }
- if( z[0]!='?' || pParse->azVar[x-1]==0 ){
- sqlite3DbFree(db, pParse->azVar[x-1]);
- pParse->azVar[x-1] = sqlite3DbStrNDup(db, z, n);
- }
- }
- }
- if( !pParse->nErr && pParse->nVar>db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER] ){
- sqlite3ErrorMsg(pParse, "too many SQL variables");
- }
- }
- /*
- ** Recursively delete an expression tree.
- */
- void sqlite3ExprDelete(sqlite3 *db, Expr *p){
- if( p==0 ) return;
- /* Sanity check: Assert that the IntValue is non-negative if it exists */
- assert( !ExprHasProperty(p, EP_IntValue) || p->u.iValue>=0 );
- if( !ExprHasProperty(p, EP_TokenOnly) ){
- /* The Expr.x union is never used at the same time as Expr.pRight */
- assert( p->x.pList==0 || p->pRight==0 );
- sqlite3ExprDelete(db, p->pLeft);
- sqlite3ExprDelete(db, p->pRight);
- if( ExprHasProperty(p, EP_MemToken) ) sqlite3DbFree(db, p->u.zToken);
- if( ExprHasProperty(p, EP_xIsSelect) ){
- sqlite3SelectDelete(db, p->x.pSelect);
- }else{
- sqlite3ExprListDelete(db, p->x.pList);
- }
- }
- if( !ExprHasProperty(p, EP_Static) ){
- sqlite3DbFree(db, p);
- }
- }
- /*
- ** Return the number of bytes allocated for the expression structure
- ** passed as the first argument. This is always one of EXPR_FULLSIZE,
- ** EXPR_REDUCEDSIZE or EXPR_TOKENONLYSIZE.
- */
- static int exprStructSize(Expr *p){
- if( ExprHasProperty(p, EP_TokenOnly) ) return EXPR_TOKENONLYSIZE;
- if( ExprHasProperty(p, EP_Reduced) ) return EXPR_REDUCEDSIZE;
- return EXPR_FULLSIZE;
- }
- /*
- ** The dupedExpr*Size() routines each return the number of bytes required
- ** to store a copy of an expression or expression tree. They differ in
- ** how much of the tree is measured.
- **
- ** dupedExprStructSize() Size of only the Expr structure
- ** dupedExprNodeSize() Size of Expr + space for token
- ** dupedExprSize() Expr + token + subtree components
- **
- ***************************************************************************
- **
- ** The dupedExprStructSize() function returns two values OR-ed together:
- ** (1) the space required for a copy of the Expr structure only and
- ** (2) the EP_xxx flags that indicate what the structure size should be.
- ** The return values is always one of:
- **
- ** EXPR_FULLSIZE
- ** EXPR_REDUCEDSIZE | EP_Reduced
- ** EXPR_TOKENONLYSIZE | EP_TokenOnly
- **
- ** The size of the structure can be found by masking the return value
- ** of this routine with 0xfff. The flags can be found by masking the
- ** return value with EP_Reduced|EP_TokenOnly.
- **
- ** Note that with flags==EXPRDUP_REDUCE, this routines works on full-size
- ** (unreduced) Expr objects as they or originally constructed by the parser.
- ** During expression analysis, extra information is computed and moved into
- ** later parts of teh Expr object and that extra information might get chopped
- ** off if the expression is reduced. Note also that it does not work to
- ** make a EXPRDUP_REDUCE copy of a reduced expression. It is only legal
- ** to reduce a pristine expression tree from the parser. The implementation
- ** of dupedExprStructSize() contain multiple assert() statements that attempt
- ** to enforce this constraint.
- */
- static int dupedExprStructSize(Expr *p, int flags){
- int nSize;
- assert( flags==EXPRDUP_REDUCE || flags==0 ); /* Only one flag value allowed */
- assert( EXPR_FULLSIZE<=0xfff );
- assert( (0xfff & (EP_Reduced|EP_TokenOnly))==0 );
- if( 0==(flags&EXPRDUP_REDUCE) ){
- nSize = EXPR_FULLSIZE;
- }else{
- assert( !ExprHasProperty(p, EP_TokenOnly|EP_Reduced) );
- assert( !ExprHasProperty(p, EP_FromJoin) );
- assert( !ExprHasProperty(p, EP_MemToken) );
- assert( !ExprHasProperty(p, EP_NoReduce) );
- if( p->pLeft || p->x.pList ){
- nSize = EXPR_REDUCEDSIZE | EP_Reduced;
- }else{
- assert( p->pRight==0 );
- nSize = EXPR_TOKENONLYSIZE | EP_TokenOnly;
- }
- }
- return nSize;
- }
- /*
- ** This function returns the space in bytes required to store the copy
- ** of the Expr structure and a copy of the Expr.u.zToken string (if that
- ** string is defined.)
- */
- static int dupedExprNodeSize(Expr *p, int flags){
- int nByte = dupedExprStructSize(p, flags) & 0xfff;
- if( !ExprHasProperty(p, EP_IntValue) && p->u.zToken ){
- nByte += sqlite3Strlen30(p->u.zToken)+1;
- }
- return ROUND8(nByte);
- }
- /*
- ** Return the number of bytes required to create a duplicate of the
- ** expression passed as the first argument. The second argument is a
- ** mask containing EXPRDUP_XXX flags.
- **
- ** The value returned includes space to create a copy of the Expr struct
- ** itself and the buffer referred to by Expr.u.zToken, if any.
- **
- ** If the EXPRDUP_REDUCE flag is set, then the return value includes
- ** space to duplicate all Expr nodes in the tree formed by Expr.pLeft
- ** and Expr.pRight variables (but not for any structures pointed to or
- ** descended from the Expr.x.pList or Expr.x.pSelect variables).
- */
- static int dupedExprSize(Expr *p, int flags){
- int nByte = 0;
- if( p ){
- nByte = dupedExprNodeSize(p, flags);
- if( flags&EXPRDUP_REDUCE ){
- nByte += dupedExprSize(p->pLeft, flags) + dupedExprSize(p->pRight, flags);
- }
- }
- return nByte;
- }
- /*
- ** This function is similar to sqlite3ExprDup(), except that if pzBuffer
- ** is not NULL then *pzBuffer is assumed to point to a buffer large enough
- ** to store the copy of expression p, the copies of p->u.zToken
- ** (if applicable), and the copies of the p->pLeft and p->pRight expressions,
- ** if any. Before returning, *pzBuffer is set to the first byte passed the
- ** portion of the buffer copied into by this function.
- */
- static Expr *exprDup(sqlite3 *db, Expr *p, int flags, u8 **pzBuffer){
- Expr *pNew = 0; /* Value to return */
- if( p ){
- const int isReduced = (flags&EXPRDUP_REDUCE);
- u8 *zAlloc;
- u32 staticFlag = 0;
- assert( pzBuffer==0 || isReduced );
- /* Figure out where to write the new Expr structure. */
- if( pzBuffer ){
- zAlloc = *pzBuffer;
- staticFlag = EP_Static;
- }else{
- zAlloc = sqlite3DbMallocRaw(db, dupedExprSize(p, flags));
- }
- pNew = (Expr *)zAlloc;
- if( pNew ){
- /* Set nNewSize to the size allocated for the structure pointed to
- ** by pNew. This is either EXPR_FULLSIZE, EXPR_REDUCEDSIZE or
- ** EXPR_TOKENONLYSIZE. nToken is set to the number of bytes consumed
- ** by the copy of the p->u.zToken string (if any).
- */
- const unsigned nStructSize = dupedExprStructSize(p, flags);
- const int nNewSize = nStructSize & 0xfff;
- int nToken;
- if( !ExprHasProperty(p, EP_IntValue) && p->u.zToken ){
- nToken = sqlite3Strlen30(p->u.zToken) + 1;
- }else{
- nToken = 0;
- }
- if( isReduced ){
- assert( ExprHasProperty(p, EP_Reduced)==0 );
- memcpy(zAlloc, p, nNewSize);
- }else{
- int nSize = exprStructSize(p);
- memcpy(zAlloc, p, nSize);
- memset(&zAlloc[nSize], 0, EXPR_FULLSIZE-nSize);
- }
- /* Set the EP_Reduced, EP_TokenOnly, and EP_Static flags appropriately. */
- pNew->flags &= ~(EP_Reduced|EP_TokenOnly|EP_Static|EP_MemToken);
- pNew->flags |= nStructSize & (EP_Reduced|EP_TokenOnly);
- pNew->flags |= staticFlag;
- /* Copy the p->u.zToken string, if any. */
- if( nToken ){
- char *zToken = pNew->u.zToken = (char*)&zAlloc[nNewSize];
- memcpy(zToken, p->u.zToken, nToken);
- }
- if( 0==((p->flags|pNew->flags) & EP_TokenOnly) ){
- /* Fill in the pNew->x.pSelect or pNew->x.pList member. */
- if( ExprHasProperty(p, EP_xIsSelect) ){
- pNew->x.pSelect = sqlite3SelectDup(db, p->x.pSelect, isReduced);
- }else{
- pNew->x.pList = sqlite3ExprListDup(db, p->x.pList, isReduced);
- }
- }
- /* Fill in pNew->pLeft and pNew->pRight. */
- if( ExprHasProperty(pNew, EP_Reduced|EP_TokenOnly) ){
- zAlloc += dupedExprNodeSize(p, flags);
- if( ExprHasProperty(pNew, EP_Reduced) ){
- pNew->pLeft = exprDup(db, p->pLeft, EXPRDUP_REDUCE, &zAlloc);
- pNew->pRight = exprDup(db, p->pRight, EXPRDUP_REDUCE, &zAlloc);
- }
- if( pzBuffer ){
- *pzBuffer = zAlloc;
- }
- }else{
- if( !ExprHasProperty(p, EP_TokenOnly) ){
- pNew->pLeft = sqlite3ExprDup(db, p->pLeft, 0);
- pNew->pRight = sqlite3ExprDup(db, p->pRight, 0);
- }
- }
- }
- }
- return pNew;
- }
- /*
- ** The following group of routines make deep copies of expressions,
- ** expression lists, ID lists, and select statements. The copies can
- ** be deleted (by being passed to their respective ...Delete() routines)
- ** without effecting the originals.
- **
- ** The expression list, ID, and source lists return by sqlite3ExprListDup(),
- ** sqlite3IdListDup(), and sqlite3SrcListDup() can not be further expanded
- ** by subsequent calls to sqlite*ListAppend() routines.
- **
- ** Any tables that the SrcList might point to are not duplicated.
- **
- ** The flags parameter contains a combination of the EXPRDUP_XXX flags.
- ** If the EXPRDUP_REDUCE flag is set, then the structure returned is a
- ** truncated version of the usual Expr structure that will be stored as
- ** part of the in-memory representation of the database schema.
- */
- Expr *sqlite3ExprDup(sqlite3 *db, Expr *p, int flags){
- return exprDup(db, p, flags, 0);
- }
- ExprList *sqlite3ExprListDup(sqlite3 *db, ExprList *p, int flags){
- ExprList *pNew;
- struct ExprList_item *pItem, *pOldItem;
- int i;
- if( p==0 ) return 0;
- pNew = sqlite3DbMallocRaw(db, sizeof(*pNew) );
- if( pNew==0 ) return 0;
- pNew->iECursor = 0;
- pNew->nExpr = i = p->nExpr;
- if( (flags & EXPRDUP_REDUCE)==0 ) for(i=1; i<p->nExpr; i+=i){}
- pNew->a = pItem = sqlite3DbMallocRaw(db, i*sizeof(p->a[0]) );
- if( pItem==0 ){
- sqlite3DbFree(db, pNew);
- return 0;
- }
- pOldItem = p->a;
- for(i=0; i<p->nExpr; i++, pItem++, pOldItem++){
- Expr *pOldExpr = pOldItem->pExpr;
- pItem->pExpr = sqlite3ExprDup(db, pOldExpr, flags);
- pItem->zName = sqlite3DbStrDup(db, pOldItem->zName);
- pItem->zSpan = sqlite3DbStrDup(db, pOldItem->zSpan);
- pItem->sortOrder = pOldItem->sortOrder;
- pItem->done = 0;
- pItem->bSpanIsTab = pOldItem->bSpanIsTab;
- pItem->iOrderByCol = pOldItem->iOrderByCol;
- pItem->iAlias = pOldItem->iAlias;
- }
- return pNew;
- }
- /*
- ** If cursors, triggers, views and subqueries are all omitted from
- ** the build, then none of the following routines, except for
- ** sqlite3SelectDup(), can be called. sqlite3SelectDup() is sometimes
- ** called with a NULL argument.
- */
- #if !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_TRIGGER) \
- || !defined(SQLITE_OMIT_SUBQUERY)
- SrcList *sqlite3SrcListDup(sqlite3 *db, SrcList *p, int flags){
- SrcList *pNew;
- int i;
- int nByte;
- if( p==0 ) return 0;
- nByte = sizeof(*p) + (p->nSrc>0 ? sizeof(p->a[0]) * (p->nSrc-1) : 0);
- pNew = sqlite3DbMallocRaw(db, nByte );
- if( pNew==0 ) return 0;
- pNew->nSrc = pNew->nAlloc = p->nSrc;
- for(i=0; i<p->nSrc; i++){
- struct SrcList_item *pNewItem = &pNew->a[i];
- struct SrcList_item *pOldItem = &p->a[i];
- Table *pTab;
- pNewItem->pSchema = pOldItem->pSchema;
- pNewItem->zDatabase = sqlite3DbStrDup(db, pOldItem->zDatabase);
- pNewItem->zName = sqlite3DbStrDup(db, pOldItem->zName);
- pNewItem->zAlias = sqlite3DbStrDup(db, pOldItem->zAlias);
- pNewItem->jointype = pOldItem->jointype;
- pNewItem->iCursor = pOldItem->iCursor;
- pNewItem->addrFillSub = pOldItem->addrFillSub;
- pNewItem->regReturn = pOldItem->regReturn;
- pNewItem->isCorrelated = pOldItem->isCorrelated;
- pNewItem->viaCoroutine = pOldItem->viaCoroutine;
- pNewItem->zIndex = sqlite3DbStrDup(db, pOldItem->zIndex);
- pNewItem->notIndexed = pOldItem->notIndexed;
- pNewItem->pIndex = pOldItem->pIndex;
- pTab = pNewItem->pTab = pOldItem->pTab;
- if( pTab ){
- pTab->nRef++;
- }
- pNewItem->pSelect = sqlite3SelectDup(db, pOldItem->pSelect, flags);
- pNewItem->pOn = sqlite3ExprDup(db, pOldItem->pOn, flags);
- pNewItem->pUsing = sqlite3IdListDup(db, pOldItem->pUsing);
- pNewItem->colUsed = pOldItem->colUsed;
- }
- return pNew;
- }
- IdList *sqlite3IdListDup(sqlite3 *db, IdList *p){
- IdList *pNew;
- int i;
- if( p==0 ) return 0;
- pNew = sqlite3DbMallocRaw(db, sizeof(*pNew) );
- if( pNew==0 ) return 0;
- pNew->nId = p->nId;
- pNew->a = sqlite3DbMallocRaw(db, p->nId*sizeof(p->a[0]) );
- if( pNew->a==0 ){
- sqlite3DbFree(db, pNew);
- return 0;
- }
- /* Note that because the size of the allocation for p->a[] is not
- ** necessarily a power of two, sqlite3IdListAppend() may not be called
- ** on the duplicate created by this function. */
- for(i=0; i<p->nId; i++){
- struct IdList_item *pNewItem = &pNew->a[i];
- struct IdList_item *pOldItem = &p->a[i];
- pNewItem->zName = sqlite3DbStrDup(db, pOldItem->zName);
- pNewItem->idx = pOldItem->idx;
- }
- return pNew;
- }
- Select *sqlite3SelectDup(sqlite3 *db, Select *p, int flags){
- Select *pNew, *pPrior;
- if( p==0 ) return 0;
- pNew = sqlite3DbMallocRaw(db, sizeof(*p) );
- if( pNew==0 ) return 0;
- pNew->pEList = sqlite3ExprListDup(db, p->pEList, flags);
- pNew->pSrc = sqlite3SrcListDup(db, p->pSrc, flags);
- pNew->pWhere = sqlite3ExprDup(db, p->pWhere, flags);
- pNew->pGroupBy = sqlite3ExprListDup(db, p->pGroupBy, flags);
- pNew->pHaving = sqlite3ExprDup(db, p->pHaving, flags);
- pNew->pOrderBy = sqlite3ExprListDup(db, p->pOrderBy, flags);
- pNew->op = p->op;
- pNew->pPrior = pPrior = sqlite3SelectDup(db, p->pPrior, flags);
- if( pPrior ) pPrior->pNext = pNew;
- pNew->pNext = 0;
- pNew->pLimit = sqlite3ExprDup(db, p->pLimit, flags);
- pNew->pOffset = sqlite3ExprDup(db, p->pOffset, flags);
- pNew->iLimit = 0;
- pNew->iOffset = 0;
- pNew->selFlags = p->selFlags & ~SF_UsesEphemeral;
- pNew->pRightmost = 0;
- pNew->addrOpenEphm[0] = -1;
- pNew->addrOpenEphm[1] = -1;
- pNew->addrOpenEphm[2] = -1;
- return pNew;
- }
- #else
- Select *sqlite3SelectDup(sqlite3 *db, Select *p, int flags){
- assert( p==0 );
- return 0;
- }
- #endif
- /*
- ** Add a new element to the end of an expression list. If pList is
- ** initially NULL, then create a new expression list.
- **
- ** If a memory allocation error occurs, the entire list is freed and
- ** NULL is returned. If non-NULL is returned, then it is guaranteed
- ** that the new entry was successfully appended.
- */
- ExprList *sqlite3ExprListAppend(
- Parse *pParse, /* Parsing context */
- ExprList *pList, /* List to which to append. Might be NULL */
- Expr *pExpr /* Expression to be appended. Might be NULL */
- ){
- sqlite3 *db = pParse->db;
- if( pList==0 ){
- pList = sqlite3DbMallocZero(db, sizeof(ExprList) );
- if( pList==0 ){
- goto no_mem;
- }
- pList->a = sqlite3DbMallocRaw(db, sizeof(pList->a[0]));
- if( pList->a==0 ) goto no_mem;
- }else if( (pList->nExpr & (pList->nExpr-1))==0 ){
- struct ExprList_item *a;
- assert( pList->nExpr>0 );
- a = sqlite3DbRealloc(db, pList->a, pList->nExpr*2*sizeof(pList->a[0]));
- if( a==0 ){
- goto no_mem;
- }
- pList->a = a;
- }
- assert( pList->a!=0 );
- if( 1 ){
- struct ExprList_item *pItem = &pList->a[pList->nExpr++];
- memset(pItem, 0, sizeof(*pItem));
- pItem->pExpr = pExpr;
- }
- return pList;
- no_mem:
- /* Avoid leaking memory if malloc has failed. */
- sqlite3ExprDelete(db, pExpr);
- sqlite3ExprListDelete(db, pList);
- return 0;
- }
- /*
- ** Set the ExprList.a[].zName element of the most recently added item
- ** on the expression list.
- **
- ** pList might be NULL following an OOM error. But pName should never be
- ** NULL. If a memory allocation fails, the pParse->db->mallocFailed flag
- ** is set.
- */
- void sqlite3ExprListSetName(
- Parse *pParse, /* Parsing context */
- ExprList *pList, /* List to which to add the span. */
- Token *pName, /* Name to be added */
- int dequote /* True to cause the name to be dequoted */
- ){
- assert( pList!=0 || pParse->db->mallocFailed!=0 );
- if( pList ){
- struct ExprList_item *pItem;
- assert( pList->nExpr>0 );
- pItem = &pList->a[pList->nExpr-1];
- assert( pItem->zName==0 );
- pItem->zName = sqlite3DbStrNDup(pParse->db, pName->z, pName->n);
- if( dequote && pItem->zName ) sqlite3Dequote(pItem->zName);
- }
- }
- /*
- ** Set the ExprList.a[].zSpan element of the most recently added item
- ** on the expression list.
- **
- ** pList might be NULL following an OOM error. But pSpan should never be
- ** NULL. If a memory allocation fails, the pParse->db->mallocFailed flag
- ** is set.
- */
- void sqlite3ExprListSetSpan(
- Parse *pParse, /* Parsing context */
- ExprList *pList, /* List to which to add the span. */
- ExprSpan *pSpan /* The span to be added */
- ){
- sqlite3 *db = pParse->db;
- assert( pList!=0 || db->mallocFailed!=0 );
- if( pList ){
- struct ExprList_item *pItem = &pList->a[pList->nExpr-1];
- assert( pList->nExpr>0 );
- assert( db->mallocFailed || pItem->pExpr==pSpan->pExpr );
- sqlite3DbFree(db, pItem->zSpan);
- pItem->zSpan = sqlite3DbStrNDup(db, (char*)pSpan->zStart,
- (int)(pSpan->zEnd - pSpan->zStart));
- }
- }
- /*
- ** If the expression list pEList contains more than iLimit elements,
- ** leave an error message in pParse.
- */
- void sqlite3ExprListCheckLength(
- Parse *pParse,
- ExprList *pEList,
- const char *zObject
- ){
- int mx = pParse->db->aLimit[SQLITE_LIMIT_COLUMN];
- testcase( pEList && pEList->nExpr==mx );
- testcase( pEList && pEList->nExpr==mx+1 );
- if( pEList && pEList->nExpr>mx ){
- sqlite3ErrorMsg(pParse, "too many columns in %s", zObject);
- }
- }
- /*
- ** Delete an entire expression list.
- */
- void sqlite3ExprListDelete(sqlite3 *db, ExprList *pList){
- int i;
- struct ExprList_item *pItem;
- if( pList==0 ) return;
- assert( pList->a!=0 || pList->nExpr==0 );
- for(pItem=pList->a, i=0; i<pList->nExpr; i++, pItem++){
- sqlite3ExprDelete(db, pItem->pExpr);
- sqlite3DbFree(db, pItem->zName);
- sqlite3DbFree(db, pItem->zSpan);
- }
- sqlite3DbFree(db, pList->a);
- sqlite3DbFree(db, pList);
- }
- /*
- ** These routines are Walker callbacks. Walker.u.pi is a pointer
- ** to an integer. These routines are checking an expression to see
- ** if it is a constant. Set *Walker.u.pi to 0 if the expression is
- ** not constant.
- **
- ** These callback routines are used to implement the following:
- **
- ** sqlite3ExprIsConstant()
- ** sqlite3ExprIsConstantNotJoin()
- ** sqlite3ExprIsConstantOrFunction()
- **
- */
- static int exprNodeIsConstant(Walker *pWalker, Expr *pExpr){
- /* If pWalker->u.i is 3 then any term of the expression that comes from
- ** the ON or USING clauses of a join disqualifies the expression
- ** from being considered constant. */
- if( pWalker->u.i==3 && ExprHasProperty(pExpr, EP_FromJoin) ){
- pWalker->u.i = 0;
- return WRC_Abort;
- }
- switch( pExpr->op ){
- /* Consider functions to be constant if all their arguments are constant
- ** and pWalker->u.i==2 */
- case TK_FUNCTION:
- if( pWalker->u.i==2 ) return 0;
- /* Fall through */
- case TK_ID:
- case TK_COLUMN:
- case TK_AGG_FUNCTION:
- case TK_AGG_COLUMN:
- testcase( pExpr->op==TK_ID );
- testcase( pExpr->op==TK_COLUMN );
- testcase( pExpr->op==TK_AGG_FUNCTION );
- testcase( pExpr->op==TK_AGG_COLUMN );
- pWalker->u.i = 0;
- return WRC_Abort;
- default:
- testcase( pExpr->op==TK_SELECT ); /* selectNodeIsConstant will disallow */
- testcase( pExpr->op==TK_EXISTS ); /* selectNodeIsConstant will disallow */
- return WRC_Continue;
- }
- }
- static int selectNodeIsConstant(Walker *pWalker, Select *NotUsed){
- UNUSED_PARAMETER(NotUsed);
- pWalker->u.i = 0;
- return WRC_Abort;
- }
- static int exprIsConst(Expr *p, int initFlag){
- Walker w;
- memset(&w, 0, sizeof(w));
- w.u.i = initFlag;
- w.xExprCallback = exprNodeIsConstant;
- w.xSelectCallback = selectNodeIsConstant;
- sqlite3WalkExpr(&w, p);
- return w.u.i;
- }
- /*
- ** Walk an expression tree. Return 1 if the expression is constant
- ** and 0 if it involves variables or function calls.
- **
- ** For the purposes of this function, a double-quoted string (ex: "abc")
- ** is considered a variable but a single-quoted string (ex: 'abc') is
- ** a constant.
- */
- int sqlite3ExprIsConstant(Expr *p){
- return exprIsConst(p, 1);
- }
- /*
- ** Walk an expression tree. Return 1 if the expression is constant
- ** that does no originate from the ON or USING clauses of a join.
- ** Return 0 if it involves variables or function calls or terms from
- ** an ON or USING clause.
- */
- int sqlite3ExprIsConstantNotJoin(Expr *p){
- return exprIsConst(p, 3);
- }
- /*
- ** Walk an expression tree. Return 1 if the expression is constant
- ** or a function call with constant arguments. Return and 0 if there
- ** are any variables.
- **
- ** For the purposes of this function, a double-quoted string (ex: "abc")
- ** is considered a variable but a single-quoted string (ex: 'abc') is
- ** a constant.
- */
- int sqlite3ExprIsConstantOrFunction(Expr *p){
- return exprIsConst(p, 2);
- }
- /*
- ** If the expression p codes a constant integer that is small enough
- ** to fit in a 32-bit integer, return 1 and put the value of the integer
- ** in *pValue. If the expression is not an integer or if it is too big
- ** to fit in a signed 32-bit integer, return 0 and leave *pValue unchanged.
- */
- int sqlite3ExprIsInteger(Expr *p, int *pValue){
- int rc = 0;
- /* If an expression is an integer literal that fits in a signed 32-bit
- ** integer, then the EP_IntValue flag will have already been set */
- assert( p->op!=TK_INTEGER || (p->flags & EP_IntValue)!=0
- || sqlite3GetInt32(p->u.zToken, &rc)==0 );
- if( p->flags & EP_IntValue ){
- *pValue = p->u.iValue;
- return 1;
- }
- switch( p->op ){
- case TK_UPLUS: {
- rc = sqlite3ExprIsInteger(p->pLeft, pValue);
- break;
- }
- case TK_UMINUS: {
- int v;
- if( sqlite3ExprIsInteger(p->pLeft, &v) ){
- assert( v!=(-2147483647-1) );
- *pValue = -v;
- rc = 1;
- }
- break;
- }
- default: break;
- }
- return rc;
- }
- /*
- ** Return FALSE if there is no chance that the expression can be NULL.
- **
- ** If the expression might be NULL or if the expression is too complex
- ** to tell return TRUE.
- **
- ** This routine is used as an optimization, to skip OP_IsNull opcodes
- ** when we know that a value cannot be NULL. Hence, a false positive
- ** (returning TRUE when in fact the expression can never be NULL) might
- ** be a small performance hit but is otherwise harmless. On the other
- ** hand, a false negative (returning FALSE when the result could be NULL)
- ** will likely result in an incorrect answer. So when in doubt, return
- ** TRUE.
- */
- int sqlite3ExprCanBeNull(const Expr *p){
- u8 op;
- while( p->op==TK_UPLUS || p->op==TK_UMINUS ){ p = p->pLeft; }
- op = p->op;
- if( op==TK_REGISTER ) op = p->op2;
- switch( op ){
- case TK_INTEGER:
- case TK_STRING:
- case TK_FLOAT:
- case TK_BLOB:
- return 0;
- default:
- return 1;
- }
- }
- /*
- ** Generate an OP_IsNull instruction that tests register iReg and jumps
- ** to location iDest if the value in iReg is NULL. The value in iReg
- ** was computed by pExpr. If we can look at pExpr at compile-time and
- ** determine that it can never generate a NULL, then the OP_IsNull operation
- ** can be omitted.
- */
- void sqlite3ExprCodeIsNullJump(
- Vdbe *v, /* The VDBE under construction */
- const Expr *pExpr, /* Only generate OP_IsNull if this expr can be NULL */
- int iReg, /* Test the value in this register for NULL */
- int iDest /* Jump here if the value is null */
- ){
- if( sqlite3ExprCanBeNull(pExpr) ){
- sqlite3VdbeAddOp2(v, OP_IsNull, iReg, iDest);
- }
- }
- /*
- ** Return TRUE if the given expression is a constant which would be
- ** unchanged by OP_Affinity with the affinity given in the second
- ** argument.
- **
- ** This routine is used to determine if the OP_Affinity operation
- ** can be omitted. When in doubt return FALSE. A false negative
- ** is harmless. A false positive, however, can result in the wrong
- ** answer.
- */
- int sqlite3ExprNeedsNoAffinityChange(const Expr *p, char aff){
- u8 op;
- if( aff==SQLITE_AFF_NONE ) return 1;
- while( p->op==TK_UPLUS || p->op==TK_UMINUS ){ p = p->pLeft; }
- op = p->op;
- if( op==TK_REGISTER ) op = p->op2;
- switch( op ){
- case TK_INTEGER: {
- return aff==SQLITE_AFF_INTEGER || aff==SQLITE_AFF_NUMERIC;
- }
- case TK_FLOAT: {
- return aff==SQLITE_AFF_REAL || aff==SQLITE_AFF_NUMERIC;
- }
- case TK_STRING: {
- return aff==SQLITE_AFF_TEXT;
- }
- case TK_BLOB: {
- return 1;
- }
- case TK_COLUMN: {
- assert( p->iTable>=0 ); /* p cannot be part of a CHECK constraint */
- return p->iColumn<0
- && (aff==SQLITE_AFF_INTEGER || aff==SQLITE_AFF_NUMERIC);
- }
- default: {
- return 0;
- }
- }
- }
- /*
- ** Return TRUE if the given string is a row-id column name.
- */
- int sqlite3IsRowid(const char *z){
- if( sqlite3StrICmp(z, "_ROWID_")==0 ) return 1;
- if( sqlite3StrICmp(z, "ROWID")==0 ) return 1;
- if( sqlite3StrICmp(z, "OID")==0 ) return 1;
- return 0;
- }
- /*
- ** Return true if we are able to the IN operator optimization on a
- ** query of the form
- **
- ** x IN (SELECT ...)
- **
- ** Where the SELECT... clause is as specified by the parameter to this
- ** routine.
- **
- ** The Select object passed in has already been preprocessed and no
- ** errors have been found.
- */
- #ifndef SQLITE_OMIT_SUBQUERY
- static int isCandidateForInOpt(Select *p){
- SrcList *pSrc;
- ExprList *pEList;
- Table *pTab;
- if( p==0 ) return 0; /* right-hand side of IN is SELECT */
- if( p->pPrior ) return 0; /* Not a compound SELECT */
- if( p->selFlags & (SF_Distinct|SF_Aggregate) ){
- testcase( (p->selFlags & (SF_Distinct|SF_Aggregate))==SF_Distinct );
- testcase( (p->selFlags & (SF_Distinct|SF_Aggregate))==SF_Aggregate );
- return 0; /* No DISTINCT keyword and no aggregate functions */
- }
- assert( p->pGroupBy==0 ); /* Has no GROUP BY clause */
- if( p->pLimit ) return 0; /* Has no LIMIT clause */
- assert( p->pOffset==0 ); /* No LIMIT means no OFFSET */
- if( p->pWhere ) return 0; /* Has no WHERE clause */
- pSrc = p->pSrc;
- assert( pSrc!=0 );
- if( pSrc->nSrc!=1 ) return 0; /* Single term in FROM clause */
- if( pSrc->a[0].pSelect ) return 0; /* FROM is not a subquery or view */
- pTab = pSrc->a[0].pTab;
- if( NEVER(pTab==0) ) return 0;
- assert( pTab->pSelect==0 ); /* FROM clause is not a view */
- if( IsVirtual(pTab) ) return 0; /* FROM clause not a virtual table */
- pEList = p->pEList;
- if( pEList->nExpr!=1 ) return 0; /* One column in the result set */
- if( pEList->a[0].pExpr->op!=TK_COLUMN ) return 0; /* Result is a column */
- return 1;
- }
- #endif /* SQLITE_OMIT_SUBQUERY */
- /*
- ** Code an OP_Once instruction and allocate space for its flag. Return the
- ** address of the new instruction.
- */
- int sqlite3CodeOnce(Parse *pParse){
- Vdbe *v = sqlite3GetVdbe(pParse); /* Virtual machine being coded */
- return sqlite3VdbeAddOp1(v, OP_Once, pParse->nOnce++);
- }
- /*
- ** This function is used by the implementation of the IN (...) operator.
- ** The pX parameter is the expression on the RHS of the IN operator, which
- ** might be either a list of expressions or a subquery.
- **
- ** The job of this routine is to find or create a b-tree object that can
- ** be used either to test for membership in the RHS set or to iterate through
- ** all members of the RHS set, skipping duplicates.
- **
- ** A cursor is opened on the b-tree object that the RHS of the IN operator
- ** and pX->iTable is set to the index of that cursor.
- **
- ** The returned value of this function indicates the b-tree type, as follows:
- **
- ** IN_INDEX_ROWID - The cursor was opened on a database table.
- ** IN_INDEX_INDEX_ASC - The cursor was opened on an ascending index.
- ** IN_INDEX_INDEX_DESC - The cursor was opened on a descending index.
- ** IN_INDEX_EPH - The cursor was opened on a specially created and
- ** populated epheremal table.
- **
- ** An existing b-tree might be used if the RHS expression pX is a simple
- ** subquery such as:
- **
- ** SELECT <column> FROM <table>
- **
- ** If the RHS of the IN operator is a list or a more complex subquery, then
- ** an ephemeral table might need to be generated from the RHS and then
- ** pX->iTable made to point to the ephermeral table instead of an
- ** existing table.
- **
- ** If the prNotFound parameter is 0, then the b-tree will be used to iterate
- ** through the set members, skipping any duplicates. In this case an
- ** epheremal table must be used unless the selected <column> is guaranteed
- ** to be unique - either because it is an INTEGER PRIMARY KEY or it
- ** has a UNIQUE constraint or UNIQUE index.
- **
- ** If the prNotFound parameter is not 0, then the b-tree will be used
- ** for fast set membership tests. In this case an epheremal table must
- ** be used unless <column> is an INTEGER PRIMARY KEY or an index can
- ** be found with <column> as its left-most column.
- **
- ** When the b-tree is being used for membership tests, the calling function
- ** needs to know whether or not the structure contains an SQL NULL
- ** value in order to correctly evaluate expressions like "X IN (Y, Z)".
- ** If there is any chance that the (...) might contain a NULL value at
- ** runtime, then a register is allocated and the register number written
- ** to *prNotFound. If there is no chance that the (...) contains a
- ** NULL value, then *prNotFound is left unchanged.
- **
- ** If a register is allocated and its location stored in *prNotFound, then
- ** its initial value is NULL. If the (...) does not remain constant
- ** for the duration of the query (i.e. the SELECT within the (...)
- ** is a correlated subquery) then the value of the allocated register is
- ** reset to NULL each time the subquery is rerun. This allows the
- ** caller to use vdbe code equivalent to the following:
- **
- ** if( register==NULL ){
- ** has_null = <test if data structure contains null>
- ** register = 1
- ** }
- **
- ** in order to avoid running the <test if data structure contains null>
- ** test more often than is necessary.
- */
- #ifndef SQLITE_OMIT_SUBQUERY
- int sqlite3FindInIndex(Parse *pParse, Expr *pX, int *prNotFound){
- Select *p; /* SELECT to the right of IN operator */
- int eType = 0; /* Type of RHS table. IN_INDEX_* */
- int iTab = pParse->nTab++; /* Cursor of the RHS table */
- int mustBeUnique = (prNotFound==0); /* True if RHS must be unique */
- Vdbe *v = sqlite3GetVdbe(pParse); /* Virtual machine being coded */
- assert( pX->op==TK_IN );
- /* Check to see if an existing table or index can be used to
- ** satisfy the query. This is preferable to generating a new
- ** ephemeral table.
- */
- p = (ExprHasProperty(pX, EP_xIsSelect) ? pX->x.pSelect : 0);
- if( ALWAYS(pParse->nErr==0) && isCandidateForInOpt(p) ){
- sqlite3 *db = pParse->db; /* Database connection */
- Table *pTab; /* Table <table>. */
- Expr *pExpr; /* Expression <column> */
- int iCol; /* Index of column <column> */
- int iDb; /* Database idx for pTab */
- assert( p ); /* Because of isCandidateForInOpt(p) */
- assert( p->pEList!=0 ); /* Because of isCandidateForInOpt(p) */
- assert( p->pEList->a[0].pExpr!=0 ); /* Because of isCandidateForInOpt(p) */
- assert( p->pSrc!=0 ); /* Because of isCandidateForInOpt(p) */
- pTab = p->pSrc->a[0].pTab;
- pExpr = p->pEList->a[0].pExpr;
- iCol = pExpr->iColumn;
-
- /* Code an OP_VerifyCookie and OP_TableLock for <table>. */
- iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
- sqlite3CodeVerifySchema(pParse, iDb);
- sqlite3TableLock(pParse, iDb, pTab->tnum, 0, pTab->zName);
- /* This function is only called from two places. In both cases the vdbe
- ** has already been allocated. So assume sqlite3GetVdbe() is always
- ** successful here.
- */
- assert(v);
- if( iCol<0 ){
- int iAddr;
- iAddr = sqlite3CodeOnce(pParse);
- sqlite3OpenTable(pParse, iTab, iDb, pTab, OP_OpenRead);
- eType = IN_INDEX_ROWID;
- sqlite3VdbeJumpHere(v, iAddr);
- }else{
- Index *pIdx; /* Iterator variable */
- /* The collation sequence used by the comparison. If an index is to
- ** be used in place of a temp-table, it must be ordered according
- ** to this collation sequence. */
- CollSeq *pReq = sqlite3BinaryCompareCollSeq(pParse, pX->pLeft, pExpr);
- /* Check that the affinity that will be used to perform the
- ** comparison is the same as the affinity of the column. If
- ** it is not, it is not possible to use any index.
- */
- int affinity_ok = sqlite3IndexAffinityOk(pX, pTab->aCol[iCol].affinity);
- for(pIdx=pTab->pIndex; pIdx && eType==0 && affinity_ok; pIdx=pIdx->pNext){
- if( (pIdx->aiColumn[0]==iCol)
- && sqlite3FindCollSeq(db, ENC(db), pIdx->azColl[0], 0)==pReq
- && (!mustBeUnique || (pIdx->nColumn==1 && pIdx->onError!=OE_None))
- ){
- int iAddr;
- char *pKey;
-
- pKey = (char *)sqlite3IndexKeyinfo(pParse, pIdx);
- iAddr = sqlite3CodeOnce(pParse);
-
- sqlite3VdbeAddOp4(v, OP_OpenRead, iTab, pIdx->tnum, iDb,
- pKey,P4_KEYINFO_HANDOFF);
- VdbeComment((v, "%s", pIdx->zName));
- assert( IN_INDEX_INDEX_DESC == IN_INDEX_INDEX_ASC+1 );
- eType = IN_INDEX_INDEX_ASC + pIdx->aSortOrder[0];
- sqlite3VdbeJumpHere(v, iAddr);
- if( prNotFound && !pTab->aCol[iCol].notNull ){
- *prNotFound = ++pParse->nMem;
- sqlite3VdbeAddOp2(v, OP_Null, 0, *prNotFound);
- }
- }
- }
- }
- }
- if( eType==0 ){
- /* Could not found an existing table or index to use as the RHS b-tree.
- ** We will have to generate an ephemeral table to do the job.
- */
- u32 savedNQueryLoop = pParse->nQueryLoop;
- int rMayHaveNull = 0;
- eType = IN_INDEX_EPH;
- if( prNotFound ){
- *prNotFound = rMayHaveNull = ++pParse->nMem;
- sqlite3VdbeAddOp2(v, OP_Null, 0, *prNotFound);
- }else{
- testcase( pParse->nQueryLoop>0 );
- pParse->nQueryLoop = 0;
- if( pX->pLeft->iColumn<0 && !ExprHasProperty(pX, EP_xIsSelect) ){
- eType = IN_INDEX_ROWID;
- }
- }
- sqlite3CodeSubselect(pParse, pX, rMayHaveNull, eType==IN_INDEX_ROWID);
- pParse->nQueryLoop = savedNQueryLoop;
- }else{
- pX->iTable = iTab;
- }
- return eType;
- }
- #endif
- /*
- ** Generate code for scalar subqueries used as a subquery expression, EXISTS,
- ** or IN operators. Examples:
- **
- ** (SELECT a FROM b) -- subquery
- ** EXISTS (SELECT a FROM b) -- EXISTS subquery
- ** x IN (4,5,11) -- IN operator with list on right-hand side
- ** x IN (SELECT a FROM b) -- IN operator with subquery on the right
- **
- ** The pExpr parameter describes the expression that contains the IN
- ** operator or subquery.
- **
- ** If parameter isRowid is non-zero, then expression pExpr is guaranteed
- ** to be of the form "<rowid> IN (?, ?, ?)", where <rowid> is a reference
- ** to some integer key column of a table B-Tree. In this case, use an
- ** intkey B-Tree to store the set of IN(...) values instead of the usual
- ** (slower) variable length keys B-Tree.
- **
- ** If rMayHaveNull is non-zero, that means that the operation is an IN
- ** (not a SELECT or EXISTS) and that the RHS might contains NULLs.
- ** Furthermore, the IN is in a WHERE clause and that we really want
- ** to iterate over the RHS of the IN operator in order to quickly locate
- ** all corresponding LHS elements. All this routine does is initialize
- ** the register given by rMayHaveNull to NULL. Calling routines will take
- ** care of changing this register value to non-NULL if the RHS is NULL-free.
- **
- ** If rMayHaveNull is zero, that means that the subquery is being used
- ** for membership testing only. There is no need to initialize any
- ** registers to indicate the presence or absence of NULLs on the RHS.
- **
- ** For a SELECT or EXISTS operator, return the register that holds the
- ** result. For IN operators or if an error occurs, the return value is 0.
- */
- #ifndef SQLITE_OMIT_SUBQUERY
- int sqlite3CodeSubselect(
- Parse *pParse, /* Parsing context */
- Expr *pExpr, /* The IN, SELECT, or EXISTS operator */
- int rMayHaveNull, /* Register that records whether NULLs exist in RHS */
- int isRowid /* If true, LHS of IN operator is a rowid */
- ){
- int testAddr = -1; /* One-time test address */
- int rReg = 0; /* Register storing resulting */
- Vdbe *v = sqlite3GetVdbe(pParse);
- if( NEVER(v==0) ) return 0;
- sqlite3ExprCachePush(pParse);
- /* This code must be run in its entirety every time it is encountered
- ** if any of the following is true:
- **
- ** * The right-hand side is a correlated subquery
- ** * The right-hand side is an expression list containing variables
- ** * We are inside a trigger
- **
- ** If all of the above are false, then we can run this code just once
- ** save the results, and reuse the same result on subsequent invocations.
- */
- if( !ExprHasProperty(pExpr, EP_VarSelect) ){
- testAddr = sqlite3CodeOnce(pParse);
- }
- #ifndef SQLITE_OMIT_EXPLAIN
- if( pParse->explain==2 ){
- char *zMsg = sqlite3MPrintf(
- pParse->db, "EXECUTE %s%s SUBQUERY %d", testAddr>=0?"":"CORRELATED ",
- pExpr->op==TK_IN?"LIST":"SCALAR", pParse->iNextSelectId
- );
- sqlite3VdbeAddOp4(v, OP_Explain, pParse->iSelectId, 0, 0, zMsg, P4_DYNAMIC);
- }
- #endif
- switch( pExpr->op ){
- case TK_IN: {
- char affinity; /* Affinity of the LHS of the IN */
- int addr; /* Address of OP_OpenEphemeral instruction */
- Expr *pLeft = pExpr->pLeft; /* the LHS of the IN operator */
- KeyInfo *pKeyInfo = 0; /* Key information */
- if( rMayHaveNull ){
- sqlite3VdbeAddOp2(v, OP_Null, 0, rMayHaveNull);
- }
- affinity = sqlite3ExprAffinity(pLeft);
- /* Whether this is an 'x IN(SELECT...)' or an 'x IN(<exprlist>)'
- ** expression it is handled the same way. An ephemeral table is
- ** filled with single-field index keys representing the results
- ** from the SELECT or the <exprlist>.
- **
- ** If the 'x' expression is a column value, or the SELECT...
- ** statement returns a column value, then the affinity of that
- ** column is used to build the index keys. If both 'x' and the
- ** SELECT... statement are columns, then numeric affinity is used
- ** if either column has NUMERIC or INTEGER affinity. If neither
- ** 'x' nor the SELECT... statement are columns, then numeric affinity
- ** is used.
- */
- pExpr->iTable = pParse->nTab++;
- addr = sqlite3VdbeAddOp2(v, OP_OpenEphemeral, pExpr->iTable, !isRowid);
- if( rMayHaveNull==0 ) sqlite3VdbeChangeP5(v, BTREE_UNORDERED);
- pKeyInfo = isRowid ? 0 : sqlite3KeyInfoAlloc(pParse->db, 1);
- if( ExprHasProperty(pExpr, EP_xIsSelect) ){
- /* Case 1: expr IN (SELECT ...)
- **
- ** Generate code to write the results of the select into the temporary
- ** table allocated and opened above.
- */
- SelectDest dest;
- ExprList *pEList;
- assert( !isRowid );
- sqlite3SelectDestInit(&dest, SRT_Set, pExpr->iTable);
- dest.affSdst = (u8)affinity;
- assert( (pExpr->iTable&0x0000FFFF)==pExpr->iTable );
- pExpr->x.pSelect->iLimit = 0;
- testcase( pKeyInfo==0 ); /* Caused by OOM in sqlite3KeyInfoAlloc() */
- if( sqlite3Select(pParse, pExpr->x.pSelect, &dest) ){
- sqlite3DbFree(pParse->db, pKeyInfo);
- return 0;
- }
- pEList = pExpr->x.pSelect->pEList;
- assert( pKeyInfo!=0 ); /* OOM will cause exit after sqlite3Select() */
- assert( pEList!=0 );
- assert( pEList->nExpr>0 );
- pKeyInfo->aColl[0] = sqlite3BinaryCompareCollSeq(pParse, pExpr->pLeft,
- pEList->a[0].pExpr);
- }else if( ALWAYS(pExpr->x.pList!=0) ){
- /* Case 2: expr IN (exprlist)
- **
- ** For each expression, build an index key from the evaluation and
- ** store it in the temporary table. If <expr> is a column, then use
- ** that columns affinity when building index keys. If <expr> is not
- ** a column, use numeric affinity.
- */
- int i;
- ExprList *pList = pExpr->x.pList;
- struct ExprList_item *pItem;
- int r1, r2, r3;
- if( !affinity ){
- affinity = SQLITE_AFF_NONE;
- }
- if( pKeyInfo ){
- pKeyInfo->aColl[0] = sqlite3ExprCollSeq(pParse, pExpr->pLeft);
- }
- /* Loop through each expression in <exprlist>. */
- r1 = sqlite3GetTempReg(pParse);
- r2 = sqlite3GetTempReg(pParse);
- sqlite3VdbeAddOp2(v, OP_Null, 0, r2);
- for(i=pList->nExpr, pItem=pList->a; i>0; i--, pItem++){
- Expr *pE2 = pItem->pExpr;
- int iValToIns;
- /* If the expression is not constant then we will need to
- ** disable the test that was generated above that makes sure
- ** this code only executes once. Because for a non-constant
- ** expression we need to rerun this code each time.
- */
- if( testAddr>=0 && !sqlite3ExprIsConstant(pE2) ){
- sqlite3VdbeChangeToNoop(v, testAddr);
- testAddr = -1;
- }
- /* Evaluate the expression and insert it into the temp table */
- if( isRowid && sqlite3ExprIsInteger(pE2, &iValToIns) ){
- sqlite3VdbeAddOp3(v, OP_InsertInt, pExpr->iTable, r2, iValToIns);
- }else{
- r3 = sqlite3ExprCodeTarget(pParse, pE2, r1);
- if( isRowid ){
- sqlite3VdbeAddOp2(v, OP_MustBeInt, r3,
- sqlite3VdbeCurrentAddr(v)+2);
- sqlite3VdbeAddOp3(v, OP_Insert, pExpr->iTable, r2, r3);
- }else{
- sqlite3VdbeAddOp4(v, OP_MakeRecord, r3, 1, r2, &affinity, 1);
- sqlite3ExprCacheAffinityChange(pParse, r3, 1);
- sqlite3VdbeAddOp2(v, OP_IdxInsert, pExpr->iTable, r2);
- }
- }
- }
- sqlite3ReleaseTempReg(pParse, r1);
- sqlite3ReleaseTempReg(pParse, r2);
- }
- if( pKeyInfo ){
- sqlite3VdbeChangeP4(v, addr, (void *)pKeyInfo, P4_KEYINFO_HANDOFF);
- }
- break;
- }
- case TK_EXISTS:
- case TK_SELECT:
- default: {
- /* If this has to be a scalar SELECT. Generate code to put the
- ** value of this select in a memory cell and record the number
- ** of the memory cell in iColumn. If this is an EXISTS, write
- ** an integer 0 (not exists) or 1 (exists) into a memory cell
- ** and record that memory cell in iColumn.
- */
- Select *pSel; /* SELECT statement to encode */
- SelectDest dest; /* How to deal with SELECt result */
- testcase( pExpr->op==TK_EXISTS );
- testcase( pExpr->op==TK_SELECT );
- assert( pExpr->op==TK_EXISTS || pExpr->op==TK_SELECT );
- assert( ExprHasProperty(pExpr, EP_xIsSelect) );
- pSel = pExpr->x.pSelect;
- sqlite3SelectDestInit(&dest, 0, ++pParse->nMem);
- if( pExpr->op==TK_SELECT ){
- dest.eDest = SRT_Mem;
- sqlite3VdbeAddOp2(v, OP_Null, 0, dest.iSDParm);
- VdbeComment((v, "Init subquery result"));
- }else{
- dest.eDest = SRT_Exists;
- sqlite3VdbeAddOp2(v, OP_Integer, 0, dest.iSDParm);
- VdbeComment((v, "Init EXISTS result"));
- }
- sqlite3ExprDelete(pParse->db, pSel->pLimit);
- pSel->pLimit = sqlite3PExpr(pParse, TK_INTEGER, 0, 0,
- &sqlite3IntTokens[1]);
- pSel->iLimit = 0;
- if( sqlite3Select(pParse, pSel, &dest) ){
- return 0;
- }
- rReg = dest.iSDParm;
- ExprSetVVAProperty(pExpr, EP_NoReduce);
- break;
- }
- }
- if( testAddr>=0 ){
- sqlite3VdbeJumpHere(v, testAddr);
- }
- sqlite3ExprCachePop(pParse, 1);
- return rReg;
- }
- #endif /* SQLITE_OMIT_SUBQUERY */
- #ifndef SQLITE_OMIT_SUBQUERY
- /*
- ** Generate code for an IN expression.
- **
- ** x IN (SELECT ...)
- ** x IN (value, value, ...)
- **
- ** The left-hand side (LHS) is a scalar expression. The right-hand side (RHS)
- ** is an array of zero or more values. The expression is true if the LHS is
- ** contained within the RHS. The value of the expression is unknown (NULL)
- ** if the LHS is NULL or if the LHS is not contained within the RHS and the
- ** RHS contains one or more NULL values.
- **
- ** This routine generates code will jump to destIfFalse if the LHS is not
- ** contained within the RHS. If due to NULLs we cannot determine if the LHS
- ** is contained in the RHS then jump to destIfNull. If the LHS is contained
- ** within the RHS then fall through.
- */
- static void sqlite3ExprCodeIN(
- Parse *pParse, /* Parsing and code generating context */
- Expr *pExpr, /* The IN expression */
- int destIfFalse, /* Jump here if LHS is not contained in the RHS */
- int destIfNull /* Jump here if the results are unknown due to NULLs */
- ){
- int rRhsHasNull = 0; /* Register that is true if RHS contains NULL values */
- char affinity; /* Comparison affinity to use */
- int eType; /* Type of the RHS */
- int r1; /* Temporary use register */
- Vdbe *v; /* Statement under construction */
- /* Compute the RHS. After this step, the table with cursor
- ** pExpr->iTable will contains the values that make up the RHS.
- */
- v = pParse->pVdbe;
- assert( v!=0 ); /* OOM detected prior to this routine */
- VdbeNoopComment((v, "begin IN expr"));
- eType = sqlite3FindInIndex(pParse, pExpr, &rRhsHasNull);
- /* Figure out the affinity to use to create a key from the results
- ** of the expression. affinityStr stores a static string suitable for
- ** P4 of OP_MakeRecord.
- */
- affinity = comparisonAffinity(pExpr);
- /* Code the LHS, the <expr> from "<expr> IN (...)".
- */
- sqlite3ExprCachePush(pParse);
- r1 = sqlite3GetTempReg(pParse);
- sqlite3ExprCode(pParse, pExpr->pLeft, r1);
- /* If the LHS is NULL, then the result is either false or NULL depending
- ** on whether the RHS is empty or not, respectively.
- */
- if( destIfNull==destIfFalse ){
- /* Shortcut for the common case where the false and NULL outcomes are
- ** the same. */
- sqlite3VdbeAddOp2(v, OP_IsNull, r1, destIfNull);
- }else{
- int addr1 = sqlite3VdbeAddOp1(v, OP_NotNull, r1);
- sqlite3VdbeAddOp2(v, OP_Rewind, pExpr->iTable, destIfFalse);
- sqlite3VdbeAddOp2(v, OP_Goto, 0, destIfNull);
- sqlite3VdbeJumpHere(v, addr1);
- }
- if( eType==IN_INDEX_ROWID ){
- /* In this case, the RHS is the ROWID of table b-tree
- */
- sqlite3VdbeAddOp2(v, OP_MustBeInt, r1, destIfFalse);
- sqlite3VdbeAddOp3(v, OP_NotExists, pExpr->iTable, destIfFalse, r1);
- }else{
- /* In this case, the RHS is an index b-tree.
- */
- sqlite3VdbeAddOp4(v, OP_Affinity, r1, 1, 0, &affinity, 1);
- /* If the set membership test fails, then the result of the
- ** "x IN (...)" expression must be either 0 or NULL. If the set
- ** contains no NULL values, then the result is 0. If the set
- ** contains one or more NULL values, then the result of the
- ** expression is also NULL.
- */
- if( rRhsHasNull==0 || destIfFalse==destIfNull ){
- /* This branch runs if it is known at compile time that the RHS
- ** cannot contain NULL values. This happens as the result
- ** of a "NOT NULL" constraint in the database schema.
- **
- ** Also run this branch if NULL is equivalent to FALSE
- ** for this particular IN operator.
- */
- sqlite3VdbeAddOp4Int(v, OP_NotFound, pExpr->iTable, destIfFalse, r1, 1);
- }else{
- /* In this branch, the RHS of the IN might contain a NULL and
- ** the presence of a NULL on the RHS makes a difference in the
- ** outcome.
- */
- int j1, j2, j3;
- /* First check to see if the LHS is contained in the RHS. If so,
- ** then the presence of NULLs in the RHS does not matter, so jump
- ** over all of the code that follows.
- */
- j1 = sqlite3VdbeAddOp4Int(v, OP_Found, pExpr->iTable, 0, r1, 1);
- /* Here we begin generating code that runs if the LHS is not
- ** contained within the RHS. Generate additional code that
- ** tests the RHS for NULLs. If the RHS contains a NULL then
- ** jump to destIfNull. If there are no NULLs in the RHS then
- ** jump to destIfFalse.
- */
- j2 = sqlite3VdbeAddOp1(v, OP_NotNull, rRhsHasNull);
- j3 = sqlite3VdbeAddOp4Int(v, OP_Found, pExpr->iTable, 0, rRhsHasNull, 1);
- sqlite3VdbeAddOp2(v, OP_Integer, -1, rRhsHasNull);
- sqlite3VdbeJumpHere(v, j3);
- sqlite3VdbeAddOp2(v, OP_AddImm, rRhsHasNull, 1);
- sqlite3VdbeJumpHere(v, j2);
- /* Jump to the appropriate target depending on whether or not
- ** the RHS contains a NULL
- */
- sqlite3VdbeAddOp2(v, OP_If, rRhsHasNull, destIfNull);
- sqlite3VdbeAddOp2(v, OP_Goto, 0, destIfFalse);
- /* The OP_Found at the top of this branch jumps here when true,
- ** causing the overall IN expression evaluation to fall through.
- */
- sqlite3VdbeJumpHere(v, j1);
- }
- }
- sqlite3ReleaseTempReg(pParse, r1);
- sqlite3ExprCachePop(pParse, 1);
- VdbeComment((v, "end IN expr"));
- }
- #endif /* SQLITE_OMIT_SUBQUERY */
- /*
- ** Duplicate an 8-byte value
- */
- static char *dup8bytes(Vdbe *v, const char *in){
- char *out = sqlite3DbMallocRaw(sqlite3VdbeDb(v), 8);
- if( out ){
- memcpy(out, in, 8);
- }
- return out;
- }
- #ifndef SQLITE_OMIT_FLOATING_POINT
- /*
- ** Generate an instruction that will put the floating point
- ** value described by z[0..n-1] into register iMem.
- **
- ** The z[] string will probably not be zero-terminated. But the
- ** z[n] character is guaranteed to be something that does not look
- ** like the continuation of the number.
- */
- static void codeReal(Vdbe *v, const char *z, int negateFlag, int iMem){
- if( ALWAYS(z!=0) ){
- double value;
- char *zV;
- sqlite3AtoF(z, &value, sqlite3Strlen30(z), SQLITE_UTF8);
- assert( !sqlite3IsNaN(value) ); /* The new AtoF never returns NaN */
- if( negateFlag ) value = -value;
- zV = dup8bytes(v, (char*)&value);
- sqlite3VdbeAddOp4(v, OP_Real, 0, iMem, 0, zV, P4_REAL);
- }
- }
- #endif
- /*
- ** Generate an instruction that will put the integer describe by
- ** text z[0..n-1] into register iMem.
- **
- ** Expr.u.zToken is always UTF8 and zero-terminated.
- */
- static void codeInteger(Parse *pParse, Expr *pExpr, int negFlag, int iMem){
- Vdbe *v = pParse->pVdbe;
- if( pExpr->flags & EP_IntValue ){
- int i = pExpr->u.iValue;
- assert( i>=0 );
- if( negFlag ) i = -i;
- sqlite3VdbeAddOp2(v, OP_Integer, i, iMem);
- }else{
- int c;
- i64 value;
- const char *z = pExpr->u.zToken;
- assert( z!=0 );
- c = sqlite3Atoi64(z, &value, sqlite3Strlen30(z), SQLITE_UTF8);
- if( c==0 || (c==2 && negFlag) ){
- char *zV;
- if( negFlag ){ value = c==2 ? SMALLEST_INT64 : -value; }
- zV = dup8bytes(v, (char*)&value);
- sqlite3VdbeAddOp4(v, OP_Int64, 0, iMem, 0, zV, P4_INT64);
- }else{
- #ifdef SQLITE_OMIT_FLOATING_POINT
- sqlite3ErrorMsg(pParse, "oversized integer: %s%s", negFlag ? "-" : "", z);
- #else
- codeReal(v, z, negFlag, iMem);
- #endif
- }
- }
- }
- /*
- ** Clear a cache entry.
- */
- static void cacheEntryClear(Parse *pParse, struct yColCache *p){
- if( p->tempReg ){
- if( pParse->nTempReg<ArraySize(pParse->aTempReg) ){
- pParse->aTempReg[pParse->nTempReg++] = p->iReg;
- }
- p->tempReg = 0;
- }
- }
- /*
- ** Record in the column cache that a particular column from a
- ** particular table is stored in a particular register.
- */
- void sqlite3ExprCacheStore(Parse *pParse, int iTab, int iCol, int iReg){
- int i;
- int minLru;
- int idxLru;
- struct yColCache *p;
- assert( iReg>0 ); /* Register numbers are always positive */
- assert( iCol>=-1 && iCol<32768 ); /* Finite column numbers */
- /* The SQLITE_ColumnCache flag disables the column cache. This is used
- ** for testing only - to verify that SQLite always gets the same answer
- ** with and without the column cache.
- */
- if( OptimizationDisabled(pParse->db, SQLITE_ColumnCache) ) return;
- /* First replace any existing entry.
- **
- ** Actually, the way the column cache is currently used, we are guaranteed
- ** that the object will never already be in cache. Verify this guarantee.
- */
- #ifndef NDEBUG
- for(i=0, p=pParse->aColCache; i<SQLITE_N_COLCACHE; i++, p++){
- assert( p->iReg==0 || p->iTable!=iTab || p->iColumn!=iCol );
- }
- #endif
- /* Find an empty slot and replace it */
- for(i=0, p=pParse->aColCache; i<SQLITE_N_COLCACHE; i++, p++){
- if( p->iReg==0 ){
- p->iLevel = pParse->iCacheLevel;
- p->iTable = iTab;
- p->iColumn = iCol;
- p->iReg = iReg;
- p->tempReg = 0;
- p->lru = pParse->iCacheCnt++;
- return;
- }
- }
- /* Replace the last recently used */
- minLru = 0x7fffffff;
- idxLru = -1;
- for(i=0, p=pParse->aColCache; i<SQLITE_N_COLCACHE; i++, p++){
- if( p->lru<minLru ){
- idxLru = i;
- minLru = p->lru;
- }
- }
- if( ALWAYS(idxLru>=0) ){
- p = &pParse->aColCache[idxLru];
- p->iLevel = pParse->iCacheLevel;
- p->iTable = iTab;
- p->iColumn = iCol;
- p->iReg = iReg;
- p->tempReg = 0;
- p->lru = pParse->iCacheCnt++;
- return;
- }
- }
- /*
- ** Indicate that registers between iReg..iReg+nReg-1 are being overwritten.
- ** Purge the range of registers from the column cache.
- */
- void sqlite3ExprCacheRemove(Parse *pParse, int iReg, int nReg){
- int i;
- int iLast = iReg + nReg - 1;
- struct yColCache *p;
- for(i=0, p=pParse->aColCache; i<SQLITE_N_COLCACHE; i++, p++){
- int r = p->iReg;
- if( r>=iReg && r<=iLast ){
- cacheEntryClear(pParse, p);
- p->iReg = 0;
- }
- }
- }
- /*
- ** Remember the current column cache context. Any new entries added
- ** added to the column cache after this call are removed when the
- ** corresponding pop occurs.
- */
- void sqlite3ExprCachePush(Parse *pParse){
- pParse->iCacheLevel++;
- }
- /*
- ** Remove from the column cache any entries that were added since the
- ** the previous N Push operations. In other words, restore the cache
- ** to the state it was in N Pushes ago.
- */
- void sqlite3ExprCachePop(Parse *pParse, int N){
- int i;
- struct yColCache *p;
- assert( N>0 );
- assert( pParse->iCacheLevel>=N );
- pParse->iCacheLevel -= N;
- for(i=0, p=pParse->aColCache; i<SQLITE_N_COLCACHE; i++, p++){
- if( p->iReg && p->iLevel>pParse->iCacheLevel ){
- cacheEntryClear(pParse, p);
- p->iReg = 0;
- }
- }
- }
- /*
- ** When a cached column is reused, make sure that its register is
- ** no longer available as a temp register. ticket #3879: that same
- ** register might be in the cache in multiple places, so be sure to
- ** get them all.
- */
- static void sqlite3ExprCachePinRegister(Parse *pParse, int iReg){
- int i;
- struct yColCache *p;
- for(i=0, p=pParse->aColCache; i<SQLITE_N_COLCACHE; i++, p++){
- if( p->iReg==iReg ){
- p->tempReg = 0;
- }
- }
- }
- /*
- ** Generate code to extract the value of the iCol-th column of a table.
- */
- void sqlite3ExprCodeGetColumnOfTable(
- Vdbe *v, /* The VDBE under construction */
- Table *pTab, /* The table containing the value */
- int iTabCur, /* The cursor for this table */
- int iCol, /* Index of the column to extract */
- int regOut /* Extract the valud into this register */
- ){
- if( iCol<0 || iCol==pTab->iPKey ){
- sqlite3VdbeAddOp2(v, OP_Rowid, iTabCur, regOut);
- }else{
- int op = IsVirtual(pTab) ? OP_VColumn : OP_Column;
- sqlite3VdbeAddOp3(v, op, iTabCur, iCol, regOut);
- }
- if( iCol>=0 ){
- sqlite3ColumnDefault(v, pTab, iCol, regOut);
- }
- }
- /*
- ** Generate code that will extract the iColumn-th column from
- ** table pTab and store the column value in a register. An effort
- ** is made to store the column value in register iReg, but this is
- ** not guaranteed. The location of the column value is returned.
- **
- ** There must be an open cursor to pTab in iTable when this routine
- ** is called. If iColumn<0 then code is generated that extracts the rowid.
- */
- int sqlite3ExprCodeGetColumn(
- Parse *pParse, /* Parsing and code generating context */
- Table *pTab, /* Description of the table we are reading from */
- int iColumn, /* Index of the table column */
- int iTable, /* The cursor pointing to the table */
- int iReg, /* Store results here */
- u8 p5 /* P5 value for OP_Column */
- ){
- Vdbe *v = pParse->pVdbe;
- int i;
- struct yColCache *p;
- for(i=0, p=pParse->aColCache; i<SQLITE_N_COLCACHE; i++, p++){
- if( p->iReg>0 && p->iTable==iTable && p->iColumn==iColumn ){
- p->lru = pParse->iCacheCnt++;
- sqlite3ExprCachePinRegister(pParse, p->iReg);
- return p->iReg;
- }
- }
- assert( v!=0 );
- sqlite3ExprCodeGetColumnOfTable(v, pTab, iTable, iColumn, iReg);
- if( p5 ){
- sqlite3VdbeChangeP5(v, p5);
- }else{
- sqlite3ExprCacheStore(pParse, iTable, iColumn, iReg);
- }
- return iReg;
- }
- /*
- ** Clear all column cache entries.
- */
- void sqlite3ExprCacheClear(Parse *pParse){
- int i;
- struct yColCache *p;
- for(i=0, p=pParse->aColCache; i<SQLITE_N_COLCACHE; i++, p++){
- if( p->iReg ){
- cacheEntryClear(pParse, p);
- p->iReg = 0;
- }
- }
- }
- /*
- ** Record the fact that an affinity change has occurred on iCount
- ** registers starting with iStart.
- */
- void sqlite3ExprCacheAffinityChange(Parse *pParse, int iStart, int iCount){
- sqlite3ExprCacheRemove(pParse, iStart, iCount);
- }
- /*
- ** Generate code to move content from registers iFrom...iFrom+nReg-1
- ** over to iTo..iTo+nReg-1. Keep the column cache up-to-date.
- */
- void sqlite3ExprCodeMove(Parse *pParse, int iFrom, int iTo, int nReg){
- int i;
- struct yColCache *p;
- assert( iFrom>=iTo+nReg || iFrom+nReg<=iTo );
- sqlite3VdbeAddOp3(pParse->pVdbe, OP_Move, iFrom, iTo, nReg-1);
- for(i=0, p=pParse->aColCache; i<SQLITE_N_COLCACHE; i++, p++){
- int x = p->iReg;
- if( x>=iFrom && x<iFrom+nReg ){
- p->iReg += iTo-iFrom;
- }
- }
- }
- #if defined(SQLITE_DEBUG) || defined(SQLITE_COVERAGE_TEST)
- /*
- ** Return true if any register in the range iFrom..iTo (inclusive)
- ** is used as part of the column cache.
- **
- ** This routine is used within assert() and testcase() macros only
- ** and does not appear in a normal build.
- */
- static int usedAsColumnCache(Parse *pParse, int iFrom, int iTo){
- int i;
- struct yColCache *p;
- for(i=0, p=pParse->aColCache; i<SQLITE_N_COLCACHE; i++, p++){
- int r = p->iReg;
- if( r>=iFrom && r<=iTo ) return 1; /*NO_TEST*/
- }
- return 0;
- }
- #endif /* SQLITE_DEBUG || SQLITE_COVERAGE_TEST */
- /*
- ** Convert an expression node to a TK_REGISTER
- */
- static void exprToRegister(Expr *p, int iReg){
- p->op2 = p->op;
- p->op = TK_REGISTER;
- p->iTable = iReg;
- ExprClearProperty(p, EP_Skip);
- }
- /*
- ** Generate code into the current Vdbe to evaluate the given
- ** expression. Attempt to store the results in register "target".
- ** Return the register where results are stored.
- **
- ** With this routine, there is no guarantee that results will
- ** be stored in target. The result might be stored in some other
- ** register if it is convenient to do so. The calling function
- ** must check the return code and move the results to the desired
- ** register.
- */
- int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target){
- Vdbe *v = pParse->pVdbe; /* The VM under construction */
- int op; /* The opcode being coded */
- int inReg = target; /* Results stored in register inReg */
- int regFree1 = 0; /* If non-zero free this temporary register */
- int regFree2 = 0; /* If non-zero free this temporary register */
- int r1, r2, r3, r4; /* Various register numbers */
- sqlite3 *db = pParse->db; /* The database connection */
- assert( target>0 && target<=pParse->nMem );
- if( v==0 ){
- assert( pParse->db->mallocFailed );
- return 0;
- }
- if( pExpr==0 ){
- op = TK_NULL;
- }else{
- op = pExpr->op;
- }
- switch( op ){
- case TK_AGG_COLUMN: {
- AggInfo *pAggInfo = pExpr->pAggInfo;
- struct AggInfo_col *pCol = &pAggInfo->aCol[pExpr->iAgg];
- if( !pAggInfo->directMode ){
- assert( pCol->iMem>0 );
- inReg = pCol->iMem;
- break;
- }else if( pAggInfo->useSortingIdx ){
- sqlite3VdbeAddOp3(v, OP_Column, pAggInfo->sortingIdxPTab,
- pCol->iSorterColumn, target);
- break;
- }
- /* Otherwise, fall thru into the TK_COLUMN case */
- }
- case TK_COLUMN: {
- int iTab = pExpr->iTable;
- if( iTab<0 ){
- if( pParse->ckBase>0 ){
- /* Generating CHECK constraints or inserting into partial index */
- inReg = pExpr->iColumn + pParse->ckBase;
- break;
- }else{
- /* Deleting from a partial index */
- iTab = pParse->iPartIdxTab;
- }
- }
- inReg = sqlite3ExprCodeGetColumn(pParse, pExpr->pTab,
- pExpr->iColumn, iTab, target,
- pExpr->op2);
- break;
- }
- case TK_INTEGER: {
- codeInteger(pParse, pExpr, 0, target);
- break;
- }
- #ifndef SQLITE_OMIT_FLOATING_POINT
- case TK_FLOAT: {
- assert( !ExprHasProperty(pExpr, EP_IntValue) );
- codeReal(v, pExpr->u.zToken, 0, target);
- break;
- }
- #endif
- case TK_STRING: {
- assert( !ExprHasProperty(pExpr, EP_IntValue) );
- sqlite3VdbeAddOp4(v, OP_String8, 0, target, 0, pExpr->u.zToken, 0);
- break;
- }
- case TK_NULL: {
- sqlite3VdbeAddOp2(v, OP_Null, 0, target);
- break;
- }
- #ifndef SQLITE_OMIT_BLOB_LITERAL
- case TK_BLOB: {
- int n;
- const char *z;
- char *zBlob;
- assert( !ExprHasProperty(pExpr, EP_IntValue) );
- assert( pExpr->u.zToken[0]=='x' || pExpr->u.zToken[0]=='X' );
- assert( pExpr->u.zToken[1]=='\'' );
- z = &pExpr->u.zToken[2];
- n = sqlite3Strlen30(z) - 1;
- assert( z[n]=='\'' );
- zBlob = sqlite3HexToBlob(sqlite3VdbeDb(v), z, n);
- sqlite3VdbeAddOp4(v, OP_Blob, n/2, target, 0, zBlob, P4_DYNAMIC);
- break;
- }
- #endif
- case TK_VARIABLE: {
- assert( !ExprHasProperty(pExpr, EP_IntValue) );
- assert( pExpr->u.zToken!=0 );
- assert( pExpr->u.zToken[0]!=0 );
- sqlite3VdbeAddOp2(v, OP_Variable, pExpr->iColumn, target);
- if( pExpr->u.zToken[1]!=0 ){
- assert( pExpr->u.zToken[0]=='?'
- || strcmp(pExpr->u.zToken, pParse->azVar[pExpr->iColumn-1])==0 );
- sqlite3VdbeChangeP4(v, -1, pParse->azVar[pExpr->iColumn-1], P4_STATIC);
- }
- break;
- }
- case TK_REGISTER: {
- inReg = pExpr->iTable;
- break;
- }
- case TK_AS: {
- inReg = sqlite3ExprCodeTarget(pParse, pExpr->pLeft, target);
- break;
- }
- #ifndef SQLITE_OMIT_CAST
- case TK_CAST: {
- /* Expressions of the form: CAST(pLeft AS token) */
- int aff, to_op;
- inReg = sqlite3ExprCodeTarget(pParse, pExpr->pLeft, target);
- assert( !ExprHasProperty(pExpr, EP_IntValue) );
- aff = sqlite3AffinityType(pExpr->u.zToken, 0);
- to_op = aff - SQLITE_AFF_TEXT + OP_ToText;
- assert( to_op==OP_ToText || aff!=SQLITE_AFF_TEXT );
- assert( to_op==OP_ToBlob || aff!=SQLITE_AFF_NONE );
- assert( to_op==OP_ToNumeric || aff!=SQLITE_AFF_NUMERIC );
- assert( to_op==OP_ToInt || aff!=SQLITE_AFF_INTEGER );
- assert( to_op==OP_ToReal || aff!=SQLITE_AFF_REAL );
- testcase( to_op==OP_ToText );
- testcase( to_op==OP_ToBlob );
- testcase( to_op==OP_ToNumeric );
- testcase( to_op==OP_ToInt );
- testcase( to_op==OP_ToReal );
- if( inReg!=target ){
- sqlite3VdbeAddOp2(v, OP_SCopy, inReg, target);
- inReg = target;
- }
- sqlite3VdbeAddOp1(v, to_op, inReg);
- testcase( usedAsColumnCache(pParse, inReg, inReg) );
- sqlite3ExprCacheAffinityChange(pParse, inReg, 1);
- break;
- }
- #endif /* SQLITE_OMIT_CAST */
- case TK_LT:
- case TK_LE:
- case TK_GT:
- case TK_GE:
- case TK_NE:
- case TK_EQ: {
- assert( TK_LT==OP_Lt );
- assert( TK_LE==OP_Le );
- assert( TK_GT==OP_Gt );
- assert( TK_GE==OP_Ge );
- assert( TK_EQ==OP_Eq );
- assert( TK_NE==OP_Ne );
- testcase( op==TK_LT );
- testcase( op==TK_LE );
- testcase( op==TK_GT );
- testcase( op==TK_GE );
- testcase( op==TK_EQ );
- testcase( op==TK_NE );
- r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free1);
- r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, ®Free2);
- codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op,
- r1, r2, inReg, SQLITE_STOREP2);
- testcase( regFree1==0 );
- testcase( regFree2==0 );
- break;
- }
- case TK_IS:
- case TK_ISNOT: {
- testcase( op==TK_IS );
- testcase( op==TK_ISNOT );
- r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free1);
- r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, ®Free2);
- op = (op==TK_IS) ? TK_EQ : TK_NE;
- codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op,
- r1, r2, inReg, SQLITE_STOREP2 | SQLITE_NULLEQ);
- testcase( regFree1==0 );
- testcase( regFree2==0 );
- break;
- }
- case TK_AND:
- case TK_OR:
- case TK_PLUS:
- case TK_STAR:
- case TK_MINUS:
- case TK_REM:
- case TK_BITAND:
- case TK_BITOR:
- case TK_SLASH:
- case TK_LSHIFT:
- case TK_RSHIFT:
- case TK_CONCAT: {
- assert( TK_AND==OP_And );
- assert( TK_OR==OP_Or );
- assert( TK_PLUS==OP_Add );
- assert( TK_MINUS==OP_Subtract );
- assert( TK_REM==OP_Remainder );
- assert( TK_BITAND==OP_BitAnd );
- assert( TK_BITOR==OP_BitOr );
- assert( TK_SLASH==OP_Divide );
- assert( TK_LSHIFT==OP_ShiftLeft );
- assert( TK_RSHIFT==OP_ShiftRight );
- assert( TK_CONCAT==OP_Concat );
- testcase( op==TK_AND );
- testcase( op==TK_OR );
- testcase( op==TK_PLUS );
- testcase( op==TK_MINUS );
- testcase( op==TK_REM );
- testcase( op==TK_BITAND );
- testcase( op==TK_BITOR );
- testcase( op==TK_SLASH );
- testcase( op==TK_LSHIFT );
- testcase( op==TK_RSHIFT );
- testcase( op==TK_CONCAT );
- r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®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_INTEGER ){
- codeInteger(pParse, pLeft, 1, target);
- #ifndef SQLITE_OMIT_FLOATING_POINT
- }else if( pLeft->op==TK_FLOAT ){
- assert( !ExprHasProperty(pExpr, EP_IntValue) );
- codeReal(v, pLeft->u.zToken, 1, target);
- #endif
- }else{
- regFree1 = r1 = sqlite3GetTempReg(pParse);
- sqlite3VdbeAddOp2(v, OP_Integer, 0, r1);
- r2 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®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 );
- r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free1);
- testcase( regFree1==0 );
- inReg = target;
- sqlite3VdbeAddOp2(v, op, r1, inReg);
- break;
- }
- case TK_ISNULL:
- case TK_NOTNULL: {
- int addr;
- assert( TK_ISNULL==OP_IsNull );
- assert( TK_NOTNULL==OP_NotNull );
- testcase( op==TK_ISNULL );
- testcase( op==TK_NOTNULL );
- sqlite3VdbeAddOp2(v, OP_Integer, 1, target);
- r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®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 ){
- assert( !ExprHasProperty(pExpr, EP_IntValue) );
- sqlite3ErrorMsg(pParse, "misuse of aggregate: %s()", pExpr->u.zToken);
- }else{
- inReg = pInfo->aFunc[pExpr->iAgg].iMem;
- }
- break;
- }
- case TK_CONST_FUNC:
- case TK_FUNCTION: {
- ExprList *pFarg; /* List of function arguments */
- int nFarg; /* Number of function arguments */
- FuncDef *pDef; /* The function definition object */
- int nId; /* Length of the function name in bytes */
- const char *zId; /* The function name */
- int constMask = 0; /* Mask of function arguments that are constant */
- int i; /* Loop counter */
- u8 enc = ENC(db); /* The text encoding used by this database */
- CollSeq *pColl = 0; /* A collating sequence */
- assert( !ExprHasProperty(pExpr, EP_xIsSelect) );
- testcase( op==TK_CONST_FUNC );
- testcase( op==TK_FUNCTION );
- if( ExprHasProperty(pExpr, EP_TokenOnly) ){
- pFarg = 0;
- }else{
- pFarg = pExpr->x.pList;
- }
- nFarg = pFarg ? pFarg->nExpr : 0;
- assert( !ExprHasProperty(pExpr, EP_IntValue) );
- zId = pExpr->u.zToken;
- nId = sqlite3Strlen30(zId);
- pDef = sqlite3FindFunction(db, zId, nId, nFarg, enc, 0);
- if( pDef==0 ){
- sqlite3ErrorMsg(pParse, "unknown function: %.*s()", nId, zId);
- break;
- }
- /* Attempt a direct implementation of the built-in COALESCE() and
- ** IFNULL() functions. This avoids unnecessary evalation of
- ** arguments past the first non-NULL argument.
- */
- if( pDef->funcFlags & SQLITE_FUNC_COALESCE ){
- int endCoalesce = sqlite3VdbeMakeLabel(v);
- assert( nFarg>=2 );
- sqlite3ExprCode(pParse, pFarg->a[0].pExpr, target);
- for(i=1; i<nFarg; i++){
- sqlite3VdbeAddOp2(v, OP_NotNull, target, endCoalesce);
- sqlite3ExprCacheRemove(pParse, target, 1);
- sqlite3ExprCachePush(pParse);
- sqlite3ExprCode(pParse, pFarg->a[i].pExpr, target);
- sqlite3ExprCachePop(pParse, 1);
- }
- sqlite3VdbeResolveLabel(v, endCoalesce);
- break;
- }
- /* The UNLIKELY() function is a no-op. The result is the value
- ** of the first argument.
- */
- if( pDef->funcFlags & SQLITE_FUNC_UNLIKELY ){
- assert( nFarg>=1 );
- sqlite3ExprCode(pParse, pFarg->a[0].pExpr, target);
- break;
- }
- if( pFarg ){
- r1 = sqlite3GetTempRange(pParse, nFarg);
- /* For length() and typeof() functions with a column argument,
- ** set the P5 parameter to the OP_Column opcode to OPFLAG_LENGTHARG
- ** or OPFLAG_TYPEOFARG respectively, to avoid unnecessary data
- ** loading.
- */
- if( (pDef->funcFlags & (SQLITE_FUNC_LENGTH|SQLITE_FUNC_TYPEOF))!=0 ){
- u8 exprOp;
- assert( nFarg==1 );
- assert( pFarg->a[0].pExpr!=0 );
- exprOp = pFarg->a[0].pExpr->op;
- if( exprOp==TK_COLUMN || exprOp==TK_AGG_COLUMN ){
- assert( SQLITE_FUNC_LENGTH==OPFLAG_LENGTHARG );
- assert( SQLITE_FUNC_TYPEOF==OPFLAG_TYPEOFARG );
- testcase( (pDef->funcFlags&~SQLITE_FUNC_ENCMASK)
- ==SQLITE_FUNC_LENGTH );
- pFarg->a[0].pExpr->op2 = pDef->funcFlags&~SQLITE_FUNC_ENCMASK;
- }
- }
- sqlite3ExprCachePush(pParse); /* Ticket 2ea2425d34be */
- sqlite3ExprCodeExprList(pParse, pFarg, r1, 1);
- sqlite3ExprCachePop(pParse, 1); /* Ticket 2ea2425d34be */
- }else{
- r1 = 0;
- }
- #ifndef SQLITE_OMIT_VIRTUALTABLE
- /* Possibly overload the function if the first argument is
- ** a virtual table column.
- **
- ** For infix functions (LIKE, GLOB, REGEXP, and MATCH) use the
- ** second argument, not the first, as the argument to test to
- ** see if it is a column in a virtual table. This is done because
- ** the left operand of infix functions (the operand we want to
- ** control overloading) ends up as the second argument to the
- ** function. The expression "A glob B" is equivalent to
- ** "glob(B,A). We want to use the A in "A glob B" to test
- ** for function overloading. But we use the B term in "glob(B,A)".
- */
- if( nFarg>=2 && (pExpr->flags & EP_InfixFunc) ){
- pDef = sqlite3VtabOverloadFunction(db, pDef, nFarg, pFarg->a[1].pExpr);
- }else if( nFarg>0 ){
- pDef = sqlite3VtabOverloadFunction(db, pDef, nFarg, pFarg->a[0].pExpr);
- }
- #endif
- for(i=0; i<nFarg; i++){
- if( i<32 && sqlite3ExprIsConstant(pFarg->a[i].pExpr) ){
- constMask |= (1<<i);
- }
- if( (pDef->funcFlags & SQLITE_FUNC_NEEDCOLL)!=0 && !pColl ){
- pColl = sqlite3ExprCollSeq(pParse, pFarg->a[i].pExpr);
- }
- }
- if( pDef->funcFlags & SQLITE_FUNC_NEEDCOLL ){
- if( !pColl ) pColl = db->pDfltColl;
- sqlite3VdbeAddOp4(v, OP_CollSeq, 0, 0, 0, (char *)pColl, P4_COLLSEQ);
- }
- sqlite3VdbeAddOp4(v, OP_Function, constMask, r1, target,
- (char*)pDef, P4_FUNCDEF);
- sqlite3VdbeChangeP5(v, (u8)nFarg);
- if( nFarg ){
- sqlite3ReleaseTempRange(pParse, r1, nFarg);
- }
- break;
- }
- #ifndef SQLITE_OMIT_SUBQUERY
- case TK_EXISTS:
- case TK_SELECT: {
- testcase( op==TK_EXISTS );
- testcase( op==TK_SELECT );
- inReg = sqlite3CodeSubselect(pParse, pExpr, 0, 0);
- break;
- }
- case TK_IN: {
- int destIfFalse = sqlite3VdbeMakeLabel(v);
- int destIfNull = sqlite3VdbeMakeLabel(v);
- sqlite3VdbeAddOp2(v, OP_Null, 0, target);
- sqlite3ExprCodeIN(pParse, pExpr, destIfFalse, destIfNull);
- sqlite3VdbeAddOp2(v, OP_Integer, 1, target);
- sqlite3VdbeResolveLabel(v, destIfFalse);
- sqlite3VdbeAddOp2(v, OP_AddImm, target, 0);
- sqlite3VdbeResolveLabel(v, destIfNull);
- break;
- }
- #endif /* SQLITE_OMIT_SUBQUERY */
- /*
- ** x BETWEEN y AND z
- **
- ** This is equivalent to
- **
- ** x>=y AND x<=z
- **
- ** X is stored in pExpr->pLeft.
- ** Y is stored in pExpr->pList->a[0].pExpr.
- ** Z is stored in pExpr->pList->a[1].pExpr.
- */
- case TK_BETWEEN: {
- Expr *pLeft = pExpr->pLeft;
- struct ExprList_item *pLItem = pExpr->x.pList->a;
- Expr *pRight = pLItem->pExpr;
- r1 = sqlite3ExprCodeTemp(pParse, pLeft, ®Free1);
- r2 = sqlite3ExprCodeTemp(pParse, pRight, ®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_COLLATE:
- case TK_UPLUS: {
- inReg = sqlite3ExprCodeTarget(pParse, pExpr->pLeft, target);
- break;
- }
- case TK_TRIGGER: {
- /* If the opcode is TK_TRIGGER, then the expression is a reference
- ** to a column in the new.* or old.* pseudo-tables available to
- ** trigger programs. In this case Expr.iTable is set to 1 for the
- ** new.* pseudo-table, or 0 for the old.* pseudo-table. Expr.iColumn
- ** is set to the column of the pseudo-table to read, or to -1 to
- ** read the rowid field.
- **
- ** The expression is implemented using an OP_Param opcode. The p1
- ** parameter is set to 0 for an old.rowid reference, or to (i+1)
- ** to reference another column of the old.* pseudo-table, where
- ** i is the index of the column. For a new.rowid reference, p1 is
- ** set to (n+1), where n is the number of columns in each pseudo-table.
- ** For a reference to any other column in the new.* pseudo-table, p1
- ** is set to (n+2+i), where n and i are as defined previously. For
- ** example, if the table on which triggers are being fired is
- ** declared as:
- **
- ** CREATE TABLE t1(a, b);
- **
- ** Then p1 is interpreted as follows:
- **
- ** p1==0 -> old.rowid p1==3 -> new.rowid
- ** p1==1 -> old.a p1==4 -> new.a
- ** p1==2 -> old.b p1==5 -> new.b
- */
- Table *pTab = pExpr->pTab;
- int p1 = pExpr->iTable * (pTab->nCol+1) + 1 + pExpr->iColumn;
- assert( pExpr->iTable==0 || pExpr->iTable==1 );
- assert( pExpr->iColumn>=-1 && pExpr->iColumn<pTab->nCol );
- assert( pTab->iPKey<0 || pExpr->iColumn!=pTab->iPKey );
- assert( p1>=0 && p1<(pTab->nCol*2+2) );
- sqlite3VdbeAddOp2(v, OP_Param, p1, target);
- VdbeComment((v, "%s.%s -> $%d",
- (pExpr->iTable ? "new" : "old"),
- (pExpr->iColumn<0 ? "rowid" : pExpr->pTab->aCol[pExpr->iColumn].zName),
- target
- ));
- #ifndef SQLITE_OMIT_FLOATING_POINT
- /* If the column has REAL affinity, it may currently be stored as an
- ** integer. Use OP_RealAffinity to make sure it is really real. */
- if( pExpr->iColumn>=0
- && pTab->aCol[pExpr->iColumn].affinity==SQLITE_AFF_REAL
- ){
- sqlite3VdbeAddOp1(v, OP_RealAffinity, target);
- }
- #endif
- break;
- }
- /*
- ** Form A:
- ** CASE x WHEN e1 THEN r1 WHEN e2 THEN r2 ... WHEN eN THEN rN ELSE y END
- **
- ** Form B:
- ** CASE WHEN e1 THEN r1 WHEN e2 THEN r2 ... WHEN eN THEN rN ELSE y END
- **
- ** Form A is can be transformed into the equivalent form B as follows:
- ** CASE WHEN x=e1 THEN r1 WHEN x=e2 THEN r2 ...
- ** WHEN x=eN THEN rN ELSE y END
- **
- ** X (if it exists) is in pExpr->pLeft.
- ** Y is in the last element of pExpr->x.pList if pExpr->x.pList->nExpr is
- ** odd. The Y is also optional. If the number of elements in x.pList
- ** is even, then Y is omitted and the "otherwise" result is NULL.
- ** Ei is in pExpr->pList->a[i*2] and Ri is pExpr->pList->a[i*2+1].
- **
- ** The result of the expression is the Ri for the first matching Ei,
- ** or if there is no matching Ei, the ELSE term Y, or if there is
- ** no ELSE term, NULL.
- */
- default: assert( op==TK_CASE ); {
- int endLabel; /* GOTO label for end of CASE stmt */
- int nextCase; /* GOTO label for next WHEN clause */
- int nExpr; /* 2x number of WHEN terms */
- int i; /* Loop counter */
- ExprList *pEList; /* List of WHEN terms */
- struct ExprList_item *aListelem; /* Array of WHEN terms */
- Expr opCompare; /* The X==Ei expression */
- Expr cacheX; /* Cached expression X */
- Expr *pX; /* The X expression */
- Expr *pTest = 0; /* X==Ei (form A) or just Ei (form B) */
- VVA_ONLY( int iCacheLevel = pParse->iCacheLevel; )
- assert( !ExprHasProperty(pExpr, EP_xIsSelect) && pExpr->x.pList );
- assert(pExpr->x.pList->nExpr > 0);
- pEList = pExpr->x.pList;
- aListelem = pEList->a;
- nExpr = pEList->nExpr;
- endLabel = sqlite3VdbeMakeLabel(v);
- if( (pX = pExpr->pLeft)!=0 ){
- cacheX = *pX;
- testcase( pX->op==TK_COLUMN );
- testcase( pX->op==TK_REGISTER );
- exprToRegister(&cacheX, sqlite3ExprCodeTemp(pParse, pX, ®Free1));
- testcase( regFree1==0 );
- opCompare.op = TK_EQ;
- opCompare.pLeft = &cacheX;
- pTest = &opCompare;
- /* Ticket b351d95f9cd5ef17e9d9dbae18f5ca8611190001:
- ** The value in regFree1 might get SCopy-ed into the file result.
- ** So make sure that the regFree1 register is not reused for other
- ** purposes and possibly overwritten. */
- regFree1 = 0;
- }
- for(i=0; i<nExpr-1; i=i+2){
- sqlite3ExprCachePush(pParse);
- if( pX ){
- assert( pTest!=0 );
- opCompare.pRight = aListelem[i].pExpr;
- }else{
- pTest = aListelem[i].pExpr;
- }
- nextCase = sqlite3VdbeMakeLabel(v);
- testcase( pTest->op==TK_COLUMN );
- sqlite3ExprIfFalse(pParse, pTest, nextCase, SQLITE_JUMPIFNULL);
- testcase( aListelem[i+1].pExpr->op==TK_COLUMN );
- testcase( aListelem[i+1].pExpr->op==TK_REGISTER );
- sqlite3ExprCode(pParse, aListelem[i+1].pExpr, target);
- sqlite3VdbeAddOp2(v, OP_Goto, 0, endLabel);
- sqlite3ExprCachePop(pParse, 1);
- sqlite3VdbeResolveLabel(v, nextCase);
- }
- if( (nExpr&1)!=0 ){
- sqlite3ExprCachePush(pParse);
- sqlite3ExprCode(pParse, pEList->a[nExpr-1].pExpr, target);
- sqlite3ExprCachePop(pParse, 1);
- }else{
- sqlite3VdbeAddOp2(v, OP_Null, 0, target);
- }
- assert( db->mallocFailed || pParse->nErr>0
- || pParse->iCacheLevel==iCacheLevel );
- sqlite3VdbeResolveLabel(v, endLabel);
- break;
- }
- #ifndef SQLITE_OMIT_TRIGGER
- case TK_RAISE: {
- assert( pExpr->affinity==OE_Rollback
- || pExpr->affinity==OE_Abort
- || pExpr->affinity==OE_Fail
- || pExpr->affinity==OE_Ignore
- );
- if( !pParse->pTriggerTab ){
- sqlite3ErrorMsg(pParse,
- "RAISE() may only be used within a trigger-program");
- return 0;
- }
- if( pExpr->affinity==OE_Abort ){
- sqlite3MayAbort(pParse);
- }
- assert( !ExprHasProperty(pExpr, EP_IntValue) );
- if( pExpr->affinity==OE_Ignore ){
- sqlite3VdbeAddOp4(
- v, OP_Halt, SQLITE_OK, OE_Ignore, 0, pExpr->u.zToken,0);
- }else{
- sqlite3HaltConstraint(pParse, SQLITE_CONSTRAINT_TRIGGER,
- pExpr->affinity, pExpr->u.zToken, 0);
- }
- break;
- }
- #endif
- }
- sqlite3ReleaseTempReg(pParse, regFree1);
- sqlite3ReleaseTempReg(pParse, regFree2);
- return inReg;
- }
- /*
- ** Generate code to evaluate an expression and store the results
- ** into a register. Return the register number where the results
- ** are stored.
- **
- ** If the register is a temporary register that can be deallocated,
- ** then write its number into *pReg. If the result register is not
- ** a temporary, then set *pReg to zero.
- */
- int sqlite3ExprCodeTemp(Parse *pParse, Expr *pExpr, int *pReg){
- int r1 = sqlite3GetTempReg(pParse);
- int r2 = sqlite3ExprCodeTarget(pParse, pExpr, r1);
- if( r2==r1 ){
- *pReg = r1;
- }else{
- sqlite3ReleaseTempReg(pParse, r1);
- *pReg = 0;
- }
- return r2;
- }
- /*
- ** Generate code that will evaluate expression pExpr and store the
- ** results in register target. The results are guaranteed to appear
- ** in register target.
- */
- int sqlite3ExprCode(Parse *pParse, Expr *pExpr, int target){
- int inReg;
- assert( target>0 && target<=pParse->nMem );
- if( pExpr && pExpr->op==TK_REGISTER ){
- sqlite3VdbeAddOp2(pParse->pVdbe, OP_Copy, pExpr->iTable, target);
- }else{
- inReg = sqlite3ExprCodeTarget(pParse, pExpr, target);
- assert( pParse->pVdbe || pParse->db->mallocFailed );
- if( inReg!=target && pParse->pVdbe ){
- sqlite3VdbeAddOp2(pParse->pVdbe, OP_SCopy, inReg, target);
- }
- }
- return target;
- }
- /*
- ** Generate code that evalutes the given expression and puts the result
- ** in register target.
- **
- ** Also make a copy of the expression results into another "cache" register
- ** and modify the expression so that the next time it is evaluated,
- ** the result is a copy of the cache register.
- **
- ** This routine is used for expressions that are used multiple
- ** times. They are evaluated once and the results of the expression
- ** are reused.
- */
- int sqlite3ExprCodeAndCache(Parse *pParse, Expr *pExpr, int target){
- Vdbe *v = pParse->pVdbe;
- int inReg;
- inReg = sqlite3ExprCode(pParse, pExpr, target);
- assert( target>0 );
- /* This routine is called for terms to INSERT or UPDATE. And the only
- ** other place where expressions can be converted into TK_REGISTER is
- ** in WHERE clause processing. So as currently implemented, there is
- ** no way for a TK_REGISTER to exist here. But it seems prudent to
- ** keep the ALWAYS() in case the conditions above change with future
- ** modifications or enhancements. */
- if( ALWAYS(pExpr->op!=TK_REGISTER) ){
- int iMem;
- iMem = ++pParse->nMem;
- sqlite3VdbeAddOp2(v, OP_Copy, inReg, iMem);
- exprToRegister(pExpr, iMem);
- }
- return inReg;
- }
- #if defined(SQLITE_ENABLE_TREE_EXPLAIN)
- /*
- ** Generate a human-readable explanation of an expression tree.
- */
- void sqlite3ExplainExpr(Vdbe *pOut, Expr *pExpr){
- int op; /* The opcode being coded */
- const char *zBinOp = 0; /* Binary operator */
- const char *zUniOp = 0; /* Unary operator */
- if( pExpr==0 ){
- op = TK_NULL;
- }else{
- op = pExpr->op;
- }
- switch( op ){
- case TK_AGG_COLUMN: {
- sqlite3ExplainPrintf(pOut, "AGG{%d:%d}",
- pExpr->iTable, pExpr->iColumn);
- break;
- }
- case TK_COLUMN: {
- if( pExpr->iTable<0 ){
- /* This only happens when coding check constraints */
- sqlite3ExplainPrintf(pOut, "COLUMN(%d)", pExpr->iColumn);
- }else{
- sqlite3ExplainPrintf(pOut, "{%d:%d}",
- pExpr->iTable, pExpr->iColumn);
- }
- break;
- }
- case TK_INTEGER: {
- if( pExpr->flags & EP_IntValue ){
- sqlite3ExplainPrintf(pOut, "%d", pExpr->u.iValue);
- }else{
- sqlite3ExplainPrintf(pOut, "%s", pExpr->u.zToken);
- }
- break;
- }
- #ifndef SQLITE_OMIT_FLOATING_POINT
- case TK_FLOAT: {
- sqlite3ExplainPrintf(pOut,"%s", pExpr->u.zToken);
- break;
- }
- #endif
- case TK_STRING: {
- sqlite3ExplainPrintf(pOut,"%Q", pExpr->u.zToken);
- break;
- }
- case TK_NULL: {
- sqlite3ExplainPrintf(pOut,"NULL");
- break;
- }
- #ifndef SQLITE_OMIT_BLOB_LITERAL
- case TK_BLOB: {
- sqlite3ExplainPrintf(pOut,"%s", pExpr->u.zToken);
- break;
- }
- #endif
- case TK_VARIABLE: {
- sqlite3ExplainPrintf(pOut,"VARIABLE(%s,%d)",
- pExpr->u.zToken, pExpr->iColumn);
- break;
- }
- case TK_REGISTER: {
- sqlite3ExplainPrintf(pOut,"REGISTER(%d)", pExpr->iTable);
- break;
- }
- case TK_AS: {
- sqlite3ExplainExpr(pOut, pExpr->pLeft);
- break;
- }
- #ifndef SQLITE_OMIT_CAST
- case TK_CAST: {
- /* Expressions of the form: CAST(pLeft AS token) */
- const char *zAff = "unk";
- switch( sqlite3AffinityType(pExpr->u.zToken, 0) ){
- case SQLITE_AFF_TEXT: zAff = "TEXT"; break;
- case SQLITE_AFF_NONE: zAff = "NONE"; break;
- case SQLITE_AFF_NUMERIC: zAff = "NUMERIC"; break;
- case SQLITE_AFF_INTEGER: zAff = "INTEGER"; break;
- case SQLITE_AFF_REAL: zAff = "REAL"; break;
- }
- sqlite3ExplainPrintf(pOut, "CAST-%s(", zAff);
- sqlite3ExplainExpr(pOut, pExpr->pLeft);
- sqlite3ExplainPrintf(pOut, ")");
- break;
- }
- #endif /* SQLITE_OMIT_CAST */
- case TK_LT: zBinOp = "LT"; break;
- case TK_LE: zBinOp = "LE"; break;
- case TK_GT: zBinOp = "GT"; break;
- case TK_GE: zBinOp = "GE"; break;
- case TK_NE: zBinOp = "NE"; break;
- case TK_EQ: zBinOp = "EQ"; break;
- case TK_IS: zBinOp = "IS"; break;
- case TK_ISNOT: zBinOp = "ISNOT"; break;
- case TK_AND: zBinOp = "AND"; break;
- case TK_OR: zBinOp = "OR"; break;
- case TK_PLUS: zBinOp = "ADD"; break;
- case TK_STAR: zBinOp = "MUL"; break;
- case TK_MINUS: zBinOp = "SUB"; break;
- case TK_REM: zBinOp = "REM"; break;
- case TK_BITAND: zBinOp = "BITAND"; break;
- case TK_BITOR: zBinOp = "BITOR"; break;
- case TK_SLASH: zBinOp = "DIV"; break;
- case TK_LSHIFT: zBinOp = "LSHIFT"; break;
- case TK_RSHIFT: zBinOp = "RSHIFT"; break;
- case TK_CONCAT: zBinOp = "CONCAT"; break;
- case TK_UMINUS: zUniOp = "UMINUS"; break;
- case TK_UPLUS: zUniOp = "UPLUS"; break;
- case TK_BITNOT: zUniOp = "BITNOT"; break;
- case TK_NOT: zUniOp = "NOT"; break;
- case TK_ISNULL: zUniOp = "ISNULL"; break;
- case TK_NOTNULL: zUniOp = "NOTNULL"; break;
- case TK_COLLATE: {
- sqlite3ExplainExpr(pOut, pExpr->pLeft);
- sqlite3ExplainPrintf(pOut,".COLLATE(%s)",pExpr->u.zToken);
- break;
- }
- case TK_AGG_FUNCTION:
- case TK_CONST_FUNC:
- case TK_FUNCTION: {
- ExprList *pFarg; /* List of function arguments */
- if( ExprHasProperty(pExpr, EP_TokenOnly) ){
- pFarg = 0;
- }else{
- pFarg = pExpr->x.pList;
- }
- if( op==TK_AGG_FUNCTION ){
- sqlite3ExplainPrintf(pOut, "AGG_FUNCTION%d:%s(",
- pExpr->op2, pExpr->u.zToken);
- }else{
- sqlite3ExplainPrintf(pOut, "FUNCTION:%s(", pExpr->u.zToken);
- }
- if( pFarg ){
- sqlite3ExplainExprList(pOut, pFarg);
- }
- sqlite3ExplainPrintf(pOut, ")");
- break;
- }
- #ifndef SQLITE_OMIT_SUBQUERY
- case TK_EXISTS: {
- sqlite3ExplainPrintf(pOut, "EXISTS(");
- sqlite3ExplainSelect(pOut, pExpr->x.pSelect);
- sqlite3ExplainPrintf(pOut,")");
- break;
- }
- case TK_SELECT: {
- sqlite3ExplainPrintf(pOut, "(");
- sqlite3ExplainSelect(pOut, pExpr->x.pSelect);
- sqlite3ExplainPrintf(pOut, ")");
- break;
- }
- case TK_IN: {
- sqlite3ExplainPrintf(pOut, "IN(");
- sqlite3ExplainExpr(pOut, pExpr->pLeft);
- sqlite3ExplainPrintf(pOut, ",");
- if( ExprHasProperty(pExpr, EP_xIsSelect) ){
- sqlite3ExplainSelect(pOut, pExpr->x.pSelect);
- }else{
- sqlite3ExplainExprList(pOut, pExpr->x.pList);
- }
- sqlite3ExplainPrintf(pOut, ")");
- break;
- }
- #endif /* SQLITE_OMIT_SUBQUERY */
- /*
- ** x BETWEEN y AND z
- **
- ** This is equivalent to
- **
- ** x>=y AND x<=z
- **
- ** X is stored in pExpr->pLeft.
- ** Y is stored in pExpr->pList->a[0].pExpr.
- ** Z is stored in pExpr->pList->a[1].pExpr.
- */
- case TK_BETWEEN: {
- Expr *pX = pExpr->pLeft;
- Expr *pY = pExpr->x.pList->a[0].pExpr;
- Expr *pZ = pExpr->x.pList->a[1].pExpr;
- sqlite3ExplainPrintf(pOut, "BETWEEN(");
- sqlite3ExplainExpr(pOut, pX);
- sqlite3ExplainPrintf(pOut, ",");
- sqlite3ExplainExpr(pOut, pY);
- sqlite3ExplainPrintf(pOut, ",");
- sqlite3ExplainExpr(pOut, pZ);
- sqlite3ExplainPrintf(pOut, ")");
- break;
- }
- case TK_TRIGGER: {
- /* If the opcode is TK_TRIGGER, then the expression is a reference
- ** to a column in the new.* or old.* pseudo-tables available to
- ** trigger programs. In this case Expr.iTable is set to 1 for the
- ** new.* pseudo-table, or 0 for the old.* pseudo-table. Expr.iColumn
- ** is set to the column of the pseudo-table to read, or to -1 to
- ** read the rowid field.
- */
- sqlite3ExplainPrintf(pOut, "%s(%d)",
- pExpr->iTable ? "NEW" : "OLD", pExpr->iColumn);
- break;
- }
- case TK_CASE: {
- sqlite3ExplainPrintf(pOut, "CASE(");
- sqlite3ExplainExpr(pOut, pExpr->pLeft);
- sqlite3ExplainPrintf(pOut, ",");
- sqlite3ExplainExprList(pOut, pExpr->x.pList);
- break;
- }
- #ifndef SQLITE_OMIT_TRIGGER
- case TK_RAISE: {
- const char *zType = "unk";
- switch( pExpr->affinity ){
- case OE_Rollback: zType = "rollback"; break;
- case OE_Abort: zType = "abort"; break;
- case OE_Fail: zType = "fail"; break;
- case OE_Ignore: zType = "ignore"; break;
- }
- sqlite3ExplainPrintf(pOut, "RAISE-%s(%s)", zType, pExpr->u.zToken);
- break;
- }
- #endif
- }
- if( zBinOp ){
- sqlite3ExplainPrintf(pOut,"%s(", zBinOp);
- sqlite3ExplainExpr(pOut, pExpr->pLeft);
- sqlite3ExplainPrintf(pOut,",");
- sqlite3ExplainExpr(pOut, pExpr->pRight);
- sqlite3ExplainPrintf(pOut,")");
- }else if( zUniOp ){
- sqlite3ExplainPrintf(pOut,"%s(", zUniOp);
- sqlite3ExplainExpr(pOut, pExpr->pLeft);
- sqlite3ExplainPrintf(pOut,")");
- }
- }
- #endif /* defined(SQLITE_ENABLE_TREE_EXPLAIN) */
- #if defined(SQLITE_ENABLE_TREE_EXPLAIN)
- /*
- ** Generate a human-readable explanation of an expression list.
- */
- void sqlite3ExplainExprList(Vdbe *pOut, ExprList *pList){
- int i;
- if( pList==0 || pList->nExpr==0 ){
- sqlite3ExplainPrintf(pOut, "(empty-list)");
- return;
- }else if( pList->nExpr==1 ){
- sqlite3ExplainExpr(pOut, pList->a[0].pExpr);
- }else{
- sqlite3ExplainPush(pOut);
- for(i=0; i<pList->nExpr; i++){
- sqlite3ExplainPrintf(pOut, "item[%d] = ", i);
- sqlite3ExplainPush(pOut);
- sqlite3ExplainExpr(pOut, pList->a[i].pExpr);
- sqlite3ExplainPop(pOut);
- if( pList->a[i].zName ){
- sqlite3ExplainPrintf(pOut, " AS %s", pList->a[i].zName);
- }
- if( pList->a[i].bSpanIsTab ){
- sqlite3ExplainPrintf(pOut, " (%s)", pList->a[i].zSpan);
- }
- if( i<pList->nExpr-1 ){
- sqlite3ExplainNL(pOut);
- }
- }
- sqlite3ExplainPop(pOut);
- }
- }
- #endif /* SQLITE_DEBUG */
- /*
- ** Return TRUE if pExpr is an constant expression that is appropriate
- ** for factoring out of a loop. Appropriate expressions are:
- **
- ** * Any expression that evaluates to two or more opcodes.
- **
- ** * Any OP_Integer, OP_Real, OP_String, OP_Blob, OP_Null,
- ** or OP_Variable that does not need to be placed in a
- ** specific register.
- **
- ** There is no point in factoring out single-instruction constant
- ** expressions that need to be placed in a particular register.
- ** We could factor them out, but then we would end up adding an
- ** OP_SCopy instruction to move the value into the correct register
- ** later. We might as well just use the original instruction and
- ** avoid the OP_SCopy.
- */
- static int isAppropriateForFactoring(Expr *p){
- if( !sqlite3ExprIsConstantNotJoin(p) ){
- return 0; /* Only constant expressions are appropriate for factoring */
- }
- if( (p->flags & EP_FixedDest)==0 ){
- return 1; /* Any constant without a fixed destination is appropriate */
- }
- while( p->op==TK_UPLUS ) p = p->pLeft;
- switch( p->op ){
- #ifndef SQLITE_OMIT_BLOB_LITERAL
- case TK_BLOB:
- #endif
- case TK_VARIABLE:
- case TK_INTEGER:
- case TK_FLOAT:
- case TK_NULL:
- case TK_STRING: {
- testcase( p->op==TK_BLOB );
- testcase( p->op==TK_VARIABLE );
- testcase( p->op==TK_INTEGER );
- testcase( p->op==TK_FLOAT );
- testcase( p->op==TK_NULL );
- testcase( p->op==TK_STRING );
- /* Single-instruction constants with a fixed destination are
- ** better done in-line. If we factor them, they will just end
- ** up generating an OP_SCopy to move the value to the destination
- ** register. */
- return 0;
- }
- case TK_UMINUS: {
- if( p->pLeft->op==TK_FLOAT || p->pLeft->op==TK_INTEGER ){
- return 0;
- }
- break;
- }
- default: {
- break;
- }
- }
- return 1;
- }
- /*
- ** If pExpr is a constant expression that is appropriate for
- ** factoring out of a loop, then evaluate the expression
- ** into a register and convert the expression into a TK_REGISTER
- ** expression.
- */
- static int evalConstExpr(Walker *pWalker, Expr *pExpr){
- Parse *pParse = pWalker->pParse;
- switch( pExpr->op ){
- case TK_IN:
- case TK_REGISTER: {
- return WRC_Prune;
- }
- case TK_COLLATE: {
- return WRC_Continue;
- }
- case TK_FUNCTION:
- case TK_AGG_FUNCTION:
- case TK_CONST_FUNC: {
- /* The arguments to a function have a fixed destination.
- ** Mark them this way to avoid generated unneeded OP_SCopy
- ** instructions.
- */
- ExprList *pList = pExpr->x.pList;
- assert( !ExprHasProperty(pExpr, EP_xIsSelect) );
- if( pList ){
- int i = pList->nExpr;
- struct ExprList_item *pItem = pList->a;
- for(; i>0; i--, pItem++){
- if( ALWAYS(pItem->pExpr) ) pItem->pExpr->flags |= EP_FixedDest;
- }
- }
- break;
- }
- }
- if( isAppropriateForFactoring(pExpr) ){
- int r1 = ++pParse->nMem;
- int r2 = sqlite3ExprCodeTarget(pParse, pExpr, r1);
- /* If r2!=r1, it means that register r1 is never used. That is harmless
- ** but suboptimal, so we want to know about the situation to fix it.
- ** Hence the following assert: */
- assert( r2==r1 );
- exprToRegister(pExpr, r2);
- return WRC_Prune;
- }
- return WRC_Continue;
- }
- /*
- ** Preevaluate constant subexpressions within pExpr and store the
- ** results in registers. Modify pExpr so that the constant subexpresions
- ** are TK_REGISTER opcodes that refer to the precomputed values.
- **
- ** This routine is a no-op if the jump to the cookie-check code has
- ** already occur. Since the cookie-check jump is generated prior to
- ** any other serious processing, this check ensures that there is no
- ** way to accidently bypass the constant initializations.
- **
- ** This routine is also a no-op if the SQLITE_FactorOutConst optimization
- ** is disabled via the sqlite3_test_control(SQLITE_TESTCTRL_OPTIMIZATIONS)
- ** interface. This allows test logic to verify that the same answer is
- ** obtained for queries regardless of whether or not constants are
- ** precomputed into registers or if they are inserted in-line.
- */
- void sqlite3ExprCodeConstants(Parse *pParse, Expr *pExpr){
- Walker w;
- if( pParse->cookieGoto ) return;
- if( OptimizationDisabled(pParse->db, SQLITE_FactorOutConst) ) return;
- memset(&w, 0, sizeof(w));
- w.xExprCallback = evalConstExpr;
- w.pParse = pParse;
- sqlite3WalkExpr(&w, pExpr);
- }
- /*
- ** Generate code that pushes the value of every element of the given
- ** expression list into a sequence of registers beginning at target.
- **
- ** Return the number of elements evaluated.
- */
- int sqlite3ExprCodeExprList(
- Parse *pParse, /* Parsing context */
- ExprList *pList, /* The expression list to be coded */
- int target, /* Where to write results */
- int doHardCopy /* Make a hard copy of every element */
- ){
- struct ExprList_item *pItem;
- int i, n;
- assert( pList!=0 );
- assert( target>0 );
- assert( pParse->pVdbe!=0 ); /* Never gets this far otherwise */
- n = pList->nExpr;
- for(pItem=pList->a, i=0; i<n; i++, pItem++){
- Expr *pExpr = pItem->pExpr;
- int inReg = sqlite3ExprCodeTarget(pParse, pExpr, target+i);
- if( inReg!=target+i ){
- sqlite3VdbeAddOp2(pParse->pVdbe, doHardCopy ? OP_Copy : OP_SCopy,
- inReg, target+i);
- }
- }
- return n;
- }
- /*
- ** Generate code for a BETWEEN operator.
- **
- ** x BETWEEN y AND z
- **
- ** The above is equivalent to
- **
- ** x>=y AND x<=z
- **
- ** Code it as such, taking care to do the common subexpression
- ** elementation of x.
- */
- static void exprCodeBetween(
- Parse *pParse, /* Parsing and code generating context */
- Expr *pExpr, /* The BETWEEN expression */
- int dest, /* Jump here if the jump is taken */
- int jumpIfTrue, /* Take the jump if the BETWEEN is true */
- int jumpIfNull /* Take the jump if the BETWEEN is NULL */
- ){
- Expr exprAnd; /* The AND operator in x>=y AND x<=z */
- Expr compLeft; /* The x>=y term */
- Expr compRight; /* The x<=z term */
- Expr exprX; /* The x subexpression */
- int regFree1 = 0; /* Temporary use register */
- assert( !ExprHasProperty(pExpr, EP_xIsSelect) );
- exprX = *pExpr->pLeft;
- exprAnd.op = TK_AND;
- exprAnd.pLeft = &compLeft;
- exprAnd.pRight = &compRight;
- compLeft.op = TK_GE;
- compLeft.pLeft = &exprX;
- compLeft.pRight = pExpr->x.pList->a[0].pExpr;
- compRight.op = TK_LE;
- compRight.pLeft = &exprX;
- compRight.pRight = pExpr->x.pList->a[1].pExpr;
- exprToRegister(&exprX, sqlite3ExprCodeTemp(pParse, &exprX, ®Free1));
- if( jumpIfTrue ){
- sqlite3ExprIfTrue(pParse, &exprAnd, dest, jumpIfNull);
- }else{
- sqlite3ExprIfFalse(pParse, &exprAnd, dest, jumpIfNull);
- }
- sqlite3ReleaseTempReg(pParse, regFree1);
- /* Ensure adequate test coverage */
- testcase( jumpIfTrue==0 && jumpIfNull==0 && regFree1==0 );
- testcase( jumpIfTrue==0 && jumpIfNull==0 && regFree1!=0 );
- testcase( jumpIfTrue==0 && jumpIfNull!=0 && regFree1==0 );
- testcase( jumpIfTrue==0 && jumpIfNull!=0 && regFree1!=0 );
- testcase( jumpIfTrue!=0 && jumpIfNull==0 && regFree1==0 );
- testcase( jumpIfTrue!=0 && jumpIfNull==0 && regFree1!=0 );
- testcase( jumpIfTrue!=0 && jumpIfNull!=0 && regFree1==0 );
- testcase( jumpIfTrue!=0 && jumpIfNull!=0 && regFree1!=0 );
- }
- /*
- ** Generate code for a boolean expression such that a jump is made
- ** to the label "dest" if the expression is true but execution
- ** continues straight thru if the expression is false.
- **
- ** If the expression evaluates to NULL (neither true nor false), then
- ** take the jump if the jumpIfNull flag is SQLITE_JUMPIFNULL.
- **
- ** This code depends on the fact that certain token values (ex: TK_EQ)
- ** are the same as opcode values (ex: OP_Eq) that implement the corresponding
- ** operation. Special comments in vdbe.c and the mkopcodeh.awk script in
- ** the make process cause these values to align. Assert()s in the code
- ** below verify that the numbers are aligned correctly.
- */
- void sqlite3ExprIfTrue(Parse *pParse, Expr *pExpr, int dest, int jumpIfNull){
- Vdbe *v = pParse->pVdbe;
- int op = 0;
- int regFree1 = 0;
- int regFree2 = 0;
- int r1, r2;
- assert( jumpIfNull==SQLITE_JUMPIFNULL || jumpIfNull==0 );
- if( NEVER(v==0) ) return; /* Existence of VDBE checked by caller */
- if( NEVER(pExpr==0) ) return; /* No way this can happen */
- op = pExpr->op;
- switch( op ){
- case TK_AND: {
- int d2 = sqlite3VdbeMakeLabel(v);
- testcase( jumpIfNull==0 );
- sqlite3ExprCachePush(pParse);
- sqlite3ExprIfFalse(pParse, pExpr->pLeft, d2,jumpIfNull^SQLITE_JUMPIFNULL);
- sqlite3ExprIfTrue(pParse, pExpr->pRight, dest, jumpIfNull);
- sqlite3VdbeResolveLabel(v, d2);
- sqlite3ExprCachePop(pParse, 1);
- break;
- }
- case TK_OR: {
- testcase( jumpIfNull==0 );
- sqlite3ExprIfTrue(pParse, pExpr->pLeft, dest, jumpIfNull);
- sqlite3ExprIfTrue(pParse, pExpr->pRight, dest, jumpIfNull);
- break;
- }
- case TK_NOT: {
- testcase( jumpIfNull==0 );
- sqlite3ExprIfFalse(pParse, pExpr->pLeft, dest, jumpIfNull);
- break;
- }
- case TK_LT:
- case TK_LE:
- case TK_GT:
- case TK_GE:
- case TK_NE:
- case TK_EQ: {
- assert( TK_LT==OP_Lt );
- assert( TK_LE==OP_Le );
- assert( TK_GT==OP_Gt );
- assert( TK_GE==OP_Ge );
- assert( TK_EQ==OP_Eq );
- assert( TK_NE==OP_Ne );
- testcase( op==TK_LT );
- testcase( op==TK_LE );
- testcase( op==TK_GT );
- testcase( op==TK_GE );
- testcase( op==TK_EQ );
- testcase( op==TK_NE );
- testcase( jumpIfNull==0 );
- r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free1);
- r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, ®Free2);
- codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op,
- r1, r2, dest, jumpIfNull);
- testcase( regFree1==0 );
- testcase( regFree2==0 );
- break;
- }
- case TK_IS:
- case TK_ISNOT: {
- testcase( op==TK_IS );
- testcase( op==TK_ISNOT );
- r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free1);
- r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, ®Free2);
- op = (op==TK_IS) ? TK_EQ : TK_NE;
- codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op,
- r1, r2, dest, SQLITE_NULLEQ);
- testcase( regFree1==0 );
- testcase( regFree2==0 );
- break;
- }
- case TK_ISNULL:
- case TK_NOTNULL: {
- assert( TK_ISNULL==OP_IsNull );
- assert( TK_NOTNULL==OP_NotNull );
- testcase( op==TK_ISNULL );
- testcase( op==TK_NOTNULL );
- r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free1);
- sqlite3VdbeAddOp2(v, op, r1, dest);
- testcase( regFree1==0 );
- break;
- }
- case TK_BETWEEN: {
- testcase( jumpIfNull==0 );
- exprCodeBetween(pParse, pExpr, dest, 1, jumpIfNull);
- break;
- }
- #ifndef SQLITE_OMIT_SUBQUERY
- case TK_IN: {
- int destIfFalse = sqlite3VdbeMakeLabel(v);
- int destIfNull = jumpIfNull ? dest : destIfFalse;
- sqlite3ExprCodeIN(pParse, pExpr, destIfFalse, destIfNull);
- sqlite3VdbeAddOp2(v, OP_Goto, 0, dest);
- sqlite3VdbeResolveLabel(v, destIfFalse);
- break;
- }
- #endif
- default: {
- r1 = sqlite3ExprCodeTemp(pParse, pExpr, ®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( NEVER(v==0) ) return; /* Existence of VDBE checked by caller */
- if( pExpr==0 ) return;
- /* The value of pExpr->op and op are related as follows:
- **
- ** pExpr->op op
- ** --------- ----------
- ** TK_ISNULL OP_NotNull
- ** TK_NOTNULL OP_IsNull
- ** TK_NE OP_Eq
- ** TK_EQ OP_Ne
- ** TK_GT OP_Le
- ** TK_LE OP_Gt
- ** TK_GE OP_Lt
- ** TK_LT OP_Ge
- **
- ** For other values of pExpr->op, op is undefined and unused.
- ** The value of TK_ and OP_ constants are arranged such that we
- ** can compute the mapping above using the following expression.
- ** Assert()s verify that the computation is correct.
- */
- op = ((pExpr->op+(TK_ISNULL&1))^1)-(TK_ISNULL&1);
- /* Verify correct alignment of TK_ and OP_ constants
- */
- assert( pExpr->op!=TK_ISNULL || op==OP_NotNull );
- assert( pExpr->op!=TK_NOTNULL || op==OP_IsNull );
- assert( pExpr->op!=TK_NE || op==OP_Eq );
- assert( pExpr->op!=TK_EQ || op==OP_Ne );
- assert( pExpr->op!=TK_LT || op==OP_Ge );
- assert( pExpr->op!=TK_LE || op==OP_Gt );
- assert( pExpr->op!=TK_GT || op==OP_Le );
- assert( pExpr->op!=TK_GE || op==OP_Lt );
- switch( pExpr->op ){
- case TK_AND: {
- testcase( jumpIfNull==0 );
- sqlite3ExprIfFalse(pParse, pExpr->pLeft, dest, jumpIfNull);
- sqlite3ExprIfFalse(pParse, pExpr->pRight, dest, jumpIfNull);
- break;
- }
- case TK_OR: {
- int d2 = sqlite3VdbeMakeLabel(v);
- testcase( jumpIfNull==0 );
- sqlite3ExprCachePush(pParse);
- sqlite3ExprIfTrue(pParse, pExpr->pLeft, d2, jumpIfNull^SQLITE_JUMPIFNULL);
- sqlite3ExprIfFalse(pParse, pExpr->pRight, dest, jumpIfNull);
- sqlite3VdbeResolveLabel(v, d2);
- sqlite3ExprCachePop(pParse, 1);
- break;
- }
- case TK_NOT: {
- testcase( jumpIfNull==0 );
- sqlite3ExprIfTrue(pParse, pExpr->pLeft, dest, jumpIfNull);
- break;
- }
- case TK_LT:
- case TK_LE:
- case TK_GT:
- case TK_GE:
- case TK_NE:
- case TK_EQ: {
- testcase( op==TK_LT );
- testcase( op==TK_LE );
- testcase( op==TK_GT );
- testcase( op==TK_GE );
- testcase( op==TK_EQ );
- testcase( op==TK_NE );
- testcase( jumpIfNull==0 );
- r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free1);
- r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, ®Free2);
- codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op,
- r1, r2, dest, jumpIfNull);
- testcase( regFree1==0 );
- testcase( regFree2==0 );
- break;
- }
- case TK_IS:
- case TK_ISNOT: {
- testcase( pExpr->op==TK_IS );
- testcase( pExpr->op==TK_ISNOT );
- r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free1);
- r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, ®Free2);
- op = (pExpr->op==TK_IS) ? TK_NE : TK_EQ;
- codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op,
- r1, r2, dest, SQLITE_NULLEQ);
- testcase( regFree1==0 );
- testcase( regFree2==0 );
- break;
- }
- case TK_ISNULL:
- case TK_NOTNULL: {
- testcase( op==TK_ISNULL );
- testcase( op==TK_NOTNULL );
- r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free1);
- sqlite3VdbeAddOp2(v, op, r1, dest);
- testcase( regFree1==0 );
- break;
- }
- case TK_BETWEEN: {
- testcase( jumpIfNull==0 );
- exprCodeBetween(pParse, pExpr, dest, 0, jumpIfNull);
- break;
- }
- #ifndef SQLITE_OMIT_SUBQUERY
- case TK_IN: {
- if( jumpIfNull ){
- sqlite3ExprCodeIN(pParse, pExpr, dest, dest);
- }else{
- int destIfNull = sqlite3VdbeMakeLabel(v);
- sqlite3ExprCodeIN(pParse, pExpr, dest, destIfNull);
- sqlite3VdbeResolveLabel(v, destIfNull);
- }
- break;
- }
- #endif
- default: {
- r1 = sqlite3ExprCodeTemp(pParse, pExpr, ®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 0 if the two
- ** expressions are completely identical. Return 1 if they differ only
- ** by a COLLATE operator at the top level. Return 2 if there are differences
- ** other than the top-level COLLATE operator.
- **
- ** If any subelement of pB has Expr.iTable==(-1) then it is allowed
- ** to compare equal to an equivalent element in pA with Expr.iTable==iTab.
- **
- ** The pA side might be using TK_REGISTER. If that is the case and pB is
- ** not using TK_REGISTER but is otherwise equivalent, then still return 0.
- **
- ** Sometimes this routine will return 2 even if the two expressions
- ** really are equivalent. If we cannot prove that the expressions are
- ** identical, we return 2 just to be safe. So if this routine
- ** returns 2, then you do not really know for certain if the two
- ** expressions are the same. But if you get a 0 or 1 return, then you
- ** can be sure the expressions are the same. In the places where
- ** this routine is used, it does not hurt to get an extra 2 - that
- ** just might result in some slightly slower code. But returning
- ** an incorrect 0 or 1 could lead to a malfunction.
- */
- int sqlite3ExprCompare(Expr *pA, Expr *pB, int iTab){
- if( pA==0||pB==0 ){
- return pB==pA ? 0 : 2;
- }
- assert( !ExprHasProperty(pA, EP_TokenOnly|EP_Reduced) );
- assert( !ExprHasProperty(pB, EP_TokenOnly|EP_Reduced) );
- if( ExprHasProperty(pA, EP_xIsSelect) || ExprHasProperty(pB, EP_xIsSelect) ){
- return 2;
- }
- if( (pA->flags & EP_Distinct)!=(pB->flags & EP_Distinct) ) return 2;
- if( pA->op!=pB->op && (pA->op!=TK_REGISTER || pA->op2!=pB->op) ){
- if( pA->op==TK_COLLATE && sqlite3ExprCompare(pA->pLeft, pB, iTab)<2 ){
- return 1;
- }
- if( pB->op==TK_COLLATE && sqlite3ExprCompare(pA, pB->pLeft, iTab)<2 ){
- return 1;
- }
- return 2;
- }
- if( sqlite3ExprCompare(pA->pLeft, pB->pLeft, iTab) ) return 2;
- if( sqlite3ExprCompare(pA->pRight, pB->pRight, iTab) ) return 2;
- if( sqlite3ExprListCompare(pA->x.pList, pB->x.pList, iTab) ) return 2;
- if( pA->iColumn!=pB->iColumn ) return 2;
- if( pA->iTable!=pB->iTable
- && pA->op!=TK_REGISTER
- && (pA->iTable!=iTab || NEVER(pB->iTable>=0)) ) return 2;
- if( ExprHasProperty(pA, EP_IntValue) ){
- if( !ExprHasProperty(pB, EP_IntValue) || pA->u.iValue!=pB->u.iValue ){
- return 2;
- }
- }else if( pA->op!=TK_COLUMN && ALWAYS(pA->op!=TK_AGG_COLUMN) && pA->u.zToken){
- if( ExprHasProperty(pB, EP_IntValue) || NEVER(pB->u.zToken==0) ) return 2;
- if( strcmp(pA->u.zToken,pB->u.zToken)!=0 ){
- return pA->op==TK_COLLATE ? 1 : 2;
- }
- }
- return 0;
- }
- /*
- ** Compare two ExprList objects. Return 0 if they are identical and
- ** non-zero if they differ in any way.
- **
- ** If any subelement of pB has Expr.iTable==(-1) then it is allowed
- ** to compare equal to an equivalent element in pA with Expr.iTable==iTab.
- **
- ** This routine might return non-zero for equivalent ExprLists. The
- ** only consequence will be disabled optimizations. But this routine
- ** must never return 0 if the two ExprList objects are different, or
- ** a malfunction will result.
- **
- ** Two NULL pointers are considered to be the same. But a NULL pointer
- ** always differs from a non-NULL pointer.
- */
- int sqlite3ExprListCompare(ExprList *pA, ExprList *pB, int iTab){
- int i;
- if( pA==0 && pB==0 ) return 0;
- if( pA==0 || pB==0 ) return 1;
- if( pA->nExpr!=pB->nExpr ) return 1;
- for(i=0; i<pA->nExpr; i++){
- Expr *pExprA = pA->a[i].pExpr;
- Expr *pExprB = pB->a[i].pExpr;
- if( pA->a[i].sortOrder!=pB->a[i].sortOrder ) return 1;
- if( sqlite3ExprCompare(pExprA, pExprB, iTab) ) return 1;
- }
- return 0;
- }
- /*
- ** Return true if we can prove the pE2 will always be true if pE1 is
- ** true. Return false if we cannot complete the proof or if pE2 might
- ** be false. Examples:
- **
- ** pE1: x==5 pE2: x==5 Result: true
- ** pE1: x>0 pE2: x==5 Result: false
- ** pE1: x=21 pE2: x=21 OR y=43 Result: true
- ** pE1: x!=123 pE2: x IS NOT NULL Result: true
- ** pE1: x!=?1 pE2: x IS NOT NULL Result: true
- ** pE1: x IS NULL pE2: x IS NOT NULL Result: false
- ** pE1: x IS ?2 pE2: x IS NOT NULL Reuslt: false
- **
- ** When comparing TK_COLUMN nodes between pE1 and pE2, if pE2 has
- ** Expr.iTable<0 then assume a table number given by iTab.
- **
- ** When in doubt, return false. Returning true might give a performance
- ** improvement. Returning false might cause a performance reduction, but
- ** it will always give the correct answer and is hence always safe.
- */
- int sqlite3ExprImpliesExpr(Expr *pE1, Expr *pE2, int iTab){
- if( sqlite3ExprCompare(pE1, pE2, iTab)==0 ){
- return 1;
- }
- if( pE2->op==TK_OR
- && (sqlite3ExprImpliesExpr(pE1, pE2->pLeft, iTab)
- || sqlite3ExprImpliesExpr(pE1, pE2->pRight, iTab) )
- ){
- return 1;
- }
- if( pE2->op==TK_NOTNULL
- && sqlite3ExprCompare(pE1->pLeft, pE2->pLeft, iTab)==0
- && (pE1->op!=TK_ISNULL && pE1->op!=TK_IS)
- ){
- return 1;
- }
- return 0;
- }
- /*
- ** An instance of the following structure is used by the tree walker
- ** to count references to table columns in the arguments of an
- ** aggregate function, in order to implement the
- ** sqlite3FunctionThisSrc() routine.
- */
- struct SrcCount {
- SrcList *pSrc; /* One particular FROM clause in a nested query */
- int nThis; /* Number of references to columns in pSrcList */
- int nOther; /* Number of references to columns in other FROM clauses */
- };
- /*
- ** Count the number of references to columns.
- */
- static int exprSrcCount(Walker *pWalker, Expr *pExpr){
- /* The NEVER() on the second term is because sqlite3FunctionUsesThisSrc()
- ** is always called before sqlite3ExprAnalyzeAggregates() and so the
- ** TK_COLUMNs have not yet been converted into TK_AGG_COLUMN. If
- ** sqlite3FunctionUsesThisSrc() is used differently in the future, the
- ** NEVER() will need to be removed. */
- if( pExpr->op==TK_COLUMN || NEVER(pExpr->op==TK_AGG_COLUMN) ){
- int i;
- struct SrcCount *p = pWalker->u.pSrcCount;
- SrcList *pSrc = p->pSrc;
- for(i=0; i<pSrc->nSrc; i++){
- if( pExpr->iTable==pSrc->a[i].iCursor ) break;
- }
- if( i<pSrc->nSrc ){
- p->nThis++;
- }else{
- p->nOther++;
- }
- }
- return WRC_Continue;
- }
- /*
- ** Determine if any of the arguments to the pExpr Function reference
- ** pSrcList. Return true if they do. Also return true if the function
- ** has no arguments or has only constant arguments. Return false if pExpr
- ** references columns but not columns of tables found in pSrcList.
- */
- int sqlite3FunctionUsesThisSrc(Expr *pExpr, SrcList *pSrcList){
- Walker w;
- struct SrcCount cnt;
- assert( pExpr->op==TK_AGG_FUNCTION );
- memset(&w, 0, sizeof(w));
- w.xExprCallback = exprSrcCount;
- w.u.pSrcCount = &cnt;
- cnt.pSrc = pSrcList;
- cnt.nThis = 0;
- cnt.nOther = 0;
- sqlite3WalkExprList(&w, pExpr->x.pList);
- return cnt.nThis>0 || cnt.nOther==0;
- }
- /*
- ** Add a new element to the pAggInfo->aCol[] array. Return the index of
- ** the new element. Return a negative number if malloc fails.
- */
- static int addAggInfoColumn(sqlite3 *db, AggInfo *pInfo){
- int i;
- pInfo->aCol = sqlite3ArrayAllocate(
- db,
- pInfo->aCol,
- sizeof(pInfo->aCol[0]),
- &pInfo->nColumn,
- &i
- );
- return i;
- }
- /*
- ** Add a new element to the pAggInfo->aFunc[] array. Return the index of
- ** the new element. Return a negative number if malloc fails.
- */
- static int addAggInfoFunc(sqlite3 *db, AggInfo *pInfo){
- int i;
- pInfo->aFunc = sqlite3ArrayAllocate(
- db,
- pInfo->aFunc,
- sizeof(pInfo->aFunc[0]),
- &pInfo->nFunc,
- &i
- );
- return i;
- }
- /*
- ** This is the xExprCallback for a tree walker. It is used to
- ** implement sqlite3ExprAnalyzeAggregates(). See sqlite3ExprAnalyzeAggregates
- ** for additional information.
- */
- static int analyzeAggregate(Walker *pWalker, Expr *pExpr){
- int i;
- NameContext *pNC = pWalker->u.pNC;
- Parse *pParse = pNC->pParse;
- SrcList *pSrcList = pNC->pSrcList;
- AggInfo *pAggInfo = pNC->pAggInfo;
- switch( pExpr->op ){
- case TK_AGG_COLUMN:
- case TK_COLUMN: {
- testcase( pExpr->op==TK_AGG_COLUMN );
- testcase( pExpr->op==TK_COLUMN );
- /* Check to see if the column is in one of the tables in the FROM
- ** clause of the aggregate query */
- if( ALWAYS(pSrcList!=0) ){
- struct SrcList_item *pItem = pSrcList->a;
- for(i=0; i<pSrcList->nSrc; i++, pItem++){
- struct AggInfo_col *pCol;
- assert( !ExprHasProperty(pExpr, EP_TokenOnly|EP_Reduced) );
- if( pExpr->iTable==pItem->iCursor ){
- /* If we reach this point, it means that pExpr refers to a table
- ** that is in the FROM clause of the aggregate query.
- **
- ** Make an entry for the column in pAggInfo->aCol[] if there
- ** is not an entry there already.
- */
- int k;
- pCol = pAggInfo->aCol;
- for(k=0; k<pAggInfo->nColumn; k++, pCol++){
- if( pCol->iTable==pExpr->iTable &&
- pCol->iColumn==pExpr->iColumn ){
- break;
- }
- }
- if( (k>=pAggInfo->nColumn)
- && (k = addAggInfoColumn(pParse->db, pAggInfo))>=0
- ){
- pCol = &pAggInfo->aCol[k];
- pCol->pTab = pExpr->pTab;
- pCol->iTable = pExpr->iTable;
- pCol->iColumn = pExpr->iColumn;
- pCol->iMem = ++pParse->nMem;
- pCol->iSorterColumn = -1;
- pCol->pExpr = pExpr;
- if( pAggInfo->pGroupBy ){
- int j, n;
- ExprList *pGB = pAggInfo->pGroupBy;
- struct ExprList_item *pTerm = pGB->a;
- n = pGB->nExpr;
- for(j=0; j<n; j++, pTerm++){
- Expr *pE = pTerm->pExpr;
- if( pE->op==TK_COLUMN && pE->iTable==pExpr->iTable &&
- pE->iColumn==pExpr->iColumn ){
- pCol->iSorterColumn = j;
- break;
- }
- }
- }
- if( pCol->iSorterColumn<0 ){
- pCol->iSorterColumn = pAggInfo->nSortingColumn++;
- }
- }
- /* There is now an entry for pExpr in pAggInfo->aCol[] (either
- ** because it was there before or because we just created it).
- ** Convert the pExpr to be a TK_AGG_COLUMN referring to that
- ** pAggInfo->aCol[] entry.
- */
- ExprSetVVAProperty(pExpr, EP_NoReduce);
- pExpr->pAggInfo = pAggInfo;
- pExpr->op = TK_AGG_COLUMN;
- pExpr->iAgg = (i16)k;
- break;
- } /* endif pExpr->iTable==pItem->iCursor */
- } /* end loop over pSrcList */
- }
- return WRC_Prune;
- }
- case TK_AGG_FUNCTION: {
- if( (pNC->ncFlags & NC_InAggFunc)==0
- && pWalker->walkerDepth==pExpr->op2
- ){
- /* 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, -1)==0 ){
- break;
- }
- }
- if( i>=pAggInfo->nFunc ){
- /* pExpr is original. Make a new entry in pAggInfo->aFunc[]
- */
- u8 enc = ENC(pParse->db);
- i = addAggInfoFunc(pParse->db, pAggInfo);
- if( i>=0 ){
- assert( !ExprHasProperty(pExpr, EP_xIsSelect) );
- pItem = &pAggInfo->aFunc[i];
- pItem->pExpr = pExpr;
- pItem->iMem = ++pParse->nMem;
- assert( !ExprHasProperty(pExpr, EP_IntValue) );
- pItem->pFunc = sqlite3FindFunction(pParse->db,
- pExpr->u.zToken, sqlite3Strlen30(pExpr->u.zToken),
- pExpr->x.pList ? pExpr->x.pList->nExpr : 0, enc, 0);
- if( pExpr->flags & EP_Distinct ){
- pItem->iDistinct = pParse->nTab++;
- }else{
- pItem->iDistinct = -1;
- }
- }
- }
- /* Make pExpr point to the appropriate pAggInfo->aFunc[] entry
- */
- assert( !ExprHasProperty(pExpr, EP_TokenOnly|EP_Reduced) );
- ExprSetVVAProperty(pExpr, EP_NoReduce);
- pExpr->iAgg = (i16)i;
- pExpr->pAggInfo = pAggInfo;
- return WRC_Prune;
- }else{
- return WRC_Continue;
- }
- }
- }
- return WRC_Continue;
- }
- static int analyzeAggregatesInSelect(Walker *pWalker, Select *pSelect){
- UNUSED_PARAMETER(pWalker);
- UNUSED_PARAMETER(pSelect);
- return WRC_Continue;
- }
- /*
- ** Analyze the pExpr expression looking for aggregate functions and
- ** for variables that need to be added to AggInfo object that pNC->pAggInfo
- ** points to. Additional entries are made on the AggInfo object as
- ** necessary.
- **
- ** This routine should only be called after the expression has been
- ** analyzed by sqlite3ResolveExprNames().
- */
- void sqlite3ExprAnalyzeAggregates(NameContext *pNC, Expr *pExpr){
- Walker w;
- memset(&w, 0, sizeof(w));
- w.xExprCallback = analyzeAggregate;
- w.xSelectCallback = analyzeAggregatesInSelect;
- w.u.pNC = pNC;
- assert( pNC->pSrcList!=0 );
- sqlite3WalkExpr(&w, pExpr);
- }
- /*
- ** 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 a single new register for use to hold some intermediate result.
- */
- int sqlite3GetTempReg(Parse *pParse){
- if( pParse->nTempReg==0 ){
- return ++pParse->nMem;
- }
- return pParse->aTempReg[--pParse->nTempReg];
- }
- /*
- ** Deallocate a register, making available for reuse for some other
- ** purpose.
- **
- ** If a register is currently being used by the column cache, then
- ** the dallocation is deferred until the column cache line that uses
- ** the register becomes stale.
- */
- void sqlite3ReleaseTempReg(Parse *pParse, int iReg){
- if( iReg && pParse->nTempReg<ArraySize(pParse->aTempReg) ){
- int i;
- struct yColCache *p;
- for(i=0, p=pParse->aColCache; i<SQLITE_N_COLCACHE; i++, p++){
- if( p->iReg==iReg ){
- p->tempReg = 1;
- return;
- }
- }
- 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 ){
- assert( !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){
- sqlite3ExprCacheRemove(pParse, iReg, nReg);
- if( nReg>pParse->nRangeReg ){
- pParse->nRangeReg = nReg;
- pParse->iRangeReg = iReg;
- }
- }
- /*
- ** Mark all temporary registers as being unavailable for reuse.
- */
- void sqlite3ClearTempRegCache(Parse *pParse){
- pParse->nTempReg = 0;
- pParse->nRangeReg = 0;
- }
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