/* ** 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" /* Forward declarations */ static void exprCodeBetween(Parse*,Expr*,int,void(*)(Parse*,Expr*,int,int),int); static int exprCodeVector(Parse *pParse, Expr *p, int *piToFree); /* ** Return the affinity character for a single column of a table. */ char sqlite3TableColumnAffinity(Table *pTab, int iCol){ assert( iColnCol ); return iCol>=0 ? pTab->aCol[iCol].affinity : SQLITE_AFF_INTEGER; } /* ** 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 expressions 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; if( pExpr->flags & EP_Generic ) return 0; while( ExprHasProperty(pExpr, EP_Skip) ){ assert( pExpr->op==TK_COLLATE ); pExpr = pExpr->pLeft; assert( pExpr!=0 ); } op = pExpr->op; if( op==TK_SELECT ){ assert( pExpr->flags&EP_xIsSelect ); return sqlite3ExprAffinity(pExpr->x.pSelect->pEList->a[0].pExpr); } if( op==TK_REGISTER ) op = pExpr->op2; #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) && pExpr->y.pTab ){ return sqlite3TableColumnAffinity(pExpr->y.pTab, pExpr->iColumn); } if( op==TK_SELECT_COLUMN ){ assert( pExpr->pLeft->flags&EP_xIsSelect ); return sqlite3ExprAffinity( pExpr->pLeft->x.pSelect->pEList->a[pExpr->iColumn].pExpr ); } 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, /* Parsing context */ Expr *pExpr, /* Add the "COLLATE" clause to this expression */ const Token *pCollName, /* Name of collating sequence */ int dequote /* True to dequote pCollName */ ){ if( pCollName->n>0 ){ Expr *pNew = sqlite3ExprAlloc(pParse->db, TK_COLLATE, pCollName, dequote); 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 ); sqlite3TokenInit(&s, (char*)zC); return sqlite3ExprAddCollateToken(pParse, pExpr, &s, 0); } /* ** Skip over any TK_COLLATE operators and any unlikely() ** or likelihood() function at the root of an expression. */ Expr *sqlite3ExprSkipCollate(Expr *pExpr){ while( pExpr && ExprHasProperty(pExpr, EP_Skip|EP_Unlikely) ){ 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 = pExpr->pLeft; } } return pExpr; } /* ** Return the collation sequence for the expression pExpr. If ** there is no defined collating sequence, return NULL. ** ** See also: sqlite3ExprNNCollSeq() ** ** The sqlite3ExprNNCollSeq() works the same exact that it returns the ** default collation if pExpr has no defined collation. ** ** 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( p->flags & EP_Generic ) break; if( op==TK_REGISTER ) op = p->op2; if( (op==TK_AGG_COLUMN || op==TK_COLUMN || op==TK_TRIGGER) && p->y.pTab!=0 ){ /* op==TK_REGISTER && p->y.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->y.pTab->aCol[j].zColl; pColl = sqlite3FindCollSeq(db, ENC(db), zColl, 0); } break; } if( op==TK_CAST || op==TK_UPLUS ){ p = p->pLeft; continue; } if( op==TK_COLLATE ){ pColl = sqlite3GetCollSeq(pParse, ENC(db), 0, p->u.zToken); break; } if( p->flags & EP_Collate ){ if( p->pLeft && (p->pLeft->flags & EP_Collate)!=0 ){ p = p->pLeft; }else{ Expr *pNext = p->pRight; /* The Expr.x union is never used at the same time as Expr.pRight */ assert( p->x.pList==0 || p->pRight==0 ); /* p->flags holds EP_Collate and p->pLeft->flags does not. And ** p->x.pSelect cannot. So if p->x.pLeft exists, it must hold at ** least one EP_Collate. Thus the following two ALWAYS. */ if( p->x.pList!=0 && ALWAYS(!ExprHasProperty(p, EP_xIsSelect)) ){ int i; for(i=0; ALWAYS(ix.pList->nExpr); i++){ if( ExprHasProperty(p->x.pList->a[i].pExpr, EP_Collate) ){ pNext = p->x.pList->a[i].pExpr; break; } } } p = pNext; } }else{ break; } } if( sqlite3CheckCollSeq(pParse, pColl) ){ pColl = 0; } return pColl; } /* ** Return the collation sequence for the expression pExpr. If ** there is no defined collating sequence, return a pointer to the ** defautl collation sequence. ** ** See also: sqlite3ExprCollSeq() ** ** The sqlite3ExprCollSeq() routine works the same except that it ** returns NULL if there is no defined collation. */ CollSeq *sqlite3ExprNNCollSeq(Parse *pParse, Expr *pExpr){ CollSeq *p = sqlite3ExprCollSeq(pParse, pExpr); if( p==0 ) p = pParse->db->pDfltColl; assert( p!=0 ); return p; } /* ** Return TRUE if the two expressions have equivalent collating sequences. */ int sqlite3ExprCollSeqMatch(Parse *pParse, Expr *pE1, Expr *pE2){ CollSeq *pColl1 = sqlite3ExprNNCollSeq(pParse, pE1); CollSeq *pColl2 = sqlite3ExprNNCollSeq(pParse, pE2); return sqlite3StrICmp(pColl1->zName, pColl2->zName)==0; } /* ** 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_BLOB; } }else if( !aff1 && !aff2 ){ /* Neither side of the comparison is a column. Compare the ** results directly. */ return SQLITE_AFF_BLOB; }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==0 ){ aff = SQLITE_AFF_BLOB; } 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_BLOB: 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; } /* ** Return true if expression pExpr is a vector, or false otherwise. ** ** A vector is defined as any expression that results in two or more ** columns of result. Every TK_VECTOR node is an vector because the ** parser will not generate a TK_VECTOR with fewer than two entries. ** But a TK_SELECT might be either a vector or a scalar. It is only ** considered a vector if it has two or more result columns. */ int sqlite3ExprIsVector(Expr *pExpr){ return sqlite3ExprVectorSize(pExpr)>1; } /* ** If the expression passed as the only argument is of type TK_VECTOR ** return the number of expressions in the vector. Or, if the expression ** is a sub-select, return the number of columns in the sub-select. For ** any other type of expression, return 1. */ int sqlite3ExprVectorSize(Expr *pExpr){ u8 op = pExpr->op; if( op==TK_REGISTER ) op = pExpr->op2; if( op==TK_VECTOR ){ return pExpr->x.pList->nExpr; }else if( op==TK_SELECT ){ return pExpr->x.pSelect->pEList->nExpr; }else{ return 1; } } /* ** Return a pointer to a subexpression of pVector that is the i-th ** column of the vector (numbered starting with 0). The caller must ** ensure that i is within range. ** ** If pVector is really a scalar (and "scalar" here includes subqueries ** that return a single column!) then return pVector unmodified. ** ** pVector retains ownership of the returned subexpression. ** ** If the vector is a (SELECT ...) then the expression returned is ** just the expression for the i-th term of the result set, and may ** not be ready for evaluation because the table cursor has not yet ** been positioned. */ Expr *sqlite3VectorFieldSubexpr(Expr *pVector, int i){ assert( iop2==0 || pVector->op==TK_REGISTER ); if( pVector->op==TK_SELECT || pVector->op2==TK_SELECT ){ return pVector->x.pSelect->pEList->a[i].pExpr; }else{ return pVector->x.pList->a[i].pExpr; } } return pVector; } /* ** Compute and return a new Expr object which when passed to ** sqlite3ExprCode() will generate all necessary code to compute ** the iField-th column of the vector expression pVector. ** ** It is ok for pVector to be a scalar (as long as iField==0). ** In that case, this routine works like sqlite3ExprDup(). ** ** The caller owns the returned Expr object and is responsible for ** ensuring that the returned value eventually gets freed. ** ** The caller retains ownership of pVector. If pVector is a TK_SELECT, ** then the returned object will reference pVector and so pVector must remain ** valid for the life of the returned object. If pVector is a TK_VECTOR ** or a scalar expression, then it can be deleted as soon as this routine ** returns. ** ** A trick to cause a TK_SELECT pVector to be deleted together with ** the returned Expr object is to attach the pVector to the pRight field ** of the returned TK_SELECT_COLUMN Expr object. */ Expr *sqlite3ExprForVectorField( Parse *pParse, /* Parsing context */ Expr *pVector, /* The vector. List of expressions or a sub-SELECT */ int iField /* Which column of the vector to return */ ){ Expr *pRet; if( pVector->op==TK_SELECT ){ assert( pVector->flags & EP_xIsSelect ); /* The TK_SELECT_COLUMN Expr node: ** ** pLeft: pVector containing TK_SELECT. Not deleted. ** pRight: not used. But recursively deleted. ** iColumn: Index of a column in pVector ** iTable: 0 or the number of columns on the LHS of an assignment ** pLeft->iTable: First in an array of register holding result, or 0 ** if the result is not yet computed. ** ** sqlite3ExprDelete() specifically skips the recursive delete of ** pLeft on TK_SELECT_COLUMN nodes. But pRight is followed, so pVector ** can be attached to pRight to cause this node to take ownership of ** pVector. Typically there will be multiple TK_SELECT_COLUMN nodes ** with the same pLeft pointer to the pVector, but only one of them ** will own the pVector. */ pRet = sqlite3PExpr(pParse, TK_SELECT_COLUMN, 0, 0); if( pRet ){ pRet->iColumn = iField; pRet->pLeft = pVector; } assert( pRet==0 || pRet->iTable==0 ); }else{ if( pVector->op==TK_VECTOR ) pVector = pVector->x.pList->a[iField].pExpr; pRet = sqlite3ExprDup(pParse->db, pVector, 0); sqlite3RenameTokenRemap(pParse, pRet, pVector); } return pRet; } /* ** If expression pExpr is of type TK_SELECT, generate code to evaluate ** it. Return the register in which the result is stored (or, if the ** sub-select returns more than one column, the first in an array ** of registers in which the result is stored). ** ** If pExpr is not a TK_SELECT expression, return 0. */ static int exprCodeSubselect(Parse *pParse, Expr *pExpr){ int reg = 0; #ifndef SQLITE_OMIT_SUBQUERY if( pExpr->op==TK_SELECT ){ reg = sqlite3CodeSubselect(pParse, pExpr); } #endif return reg; } /* ** Argument pVector points to a vector expression - either a TK_VECTOR ** or TK_SELECT that returns more than one column. This function returns ** the register number of a register that contains the value of ** element iField of the vector. ** ** If pVector is a TK_SELECT expression, then code for it must have ** already been generated using the exprCodeSubselect() routine. In this ** case parameter regSelect should be the first in an array of registers ** containing the results of the sub-select. ** ** If pVector is of type TK_VECTOR, then code for the requested field ** is generated. In this case (*pRegFree) may be set to the number of ** a temporary register to be freed by the caller before returning. ** ** Before returning, output parameter (*ppExpr) is set to point to the ** Expr object corresponding to element iElem of the vector. */ static int exprVectorRegister( Parse *pParse, /* Parse context */ Expr *pVector, /* Vector to extract element from */ int iField, /* Field to extract from pVector */ int regSelect, /* First in array of registers */ Expr **ppExpr, /* OUT: Expression element */ int *pRegFree /* OUT: Temp register to free */ ){ u8 op = pVector->op; assert( op==TK_VECTOR || op==TK_REGISTER || op==TK_SELECT ); if( op==TK_REGISTER ){ *ppExpr = sqlite3VectorFieldSubexpr(pVector, iField); return pVector->iTable+iField; } if( op==TK_SELECT ){ *ppExpr = pVector->x.pSelect->pEList->a[iField].pExpr; return regSelect+iField; } *ppExpr = pVector->x.pList->a[iField].pExpr; return sqlite3ExprCodeTemp(pParse, *ppExpr, pRegFree); } /* ** Expression pExpr is a comparison between two vector values. Compute ** the result of the comparison (1, 0, or NULL) and write that ** result into register dest. ** ** The caller must satisfy the following preconditions: ** ** if pExpr->op==TK_IS: op==TK_EQ and p5==SQLITE_NULLEQ ** if pExpr->op==TK_ISNOT: op==TK_NE and p5==SQLITE_NULLEQ ** otherwise: op==pExpr->op and p5==0 */ static void codeVectorCompare( Parse *pParse, /* Code generator context */ Expr *pExpr, /* The comparison operation */ int dest, /* Write results into this register */ u8 op, /* Comparison operator */ u8 p5 /* SQLITE_NULLEQ or zero */ ){ Vdbe *v = pParse->pVdbe; Expr *pLeft = pExpr->pLeft; Expr *pRight = pExpr->pRight; int nLeft = sqlite3ExprVectorSize(pLeft); int i; int regLeft = 0; int regRight = 0; u8 opx = op; int addrDone = sqlite3VdbeMakeLabel(pParse); if( nLeft!=sqlite3ExprVectorSize(pRight) ){ sqlite3ErrorMsg(pParse, "row value misused"); return; } assert( pExpr->op==TK_EQ || pExpr->op==TK_NE || pExpr->op==TK_IS || pExpr->op==TK_ISNOT || pExpr->op==TK_LT || pExpr->op==TK_GT || pExpr->op==TK_LE || pExpr->op==TK_GE ); assert( pExpr->op==op || (pExpr->op==TK_IS && op==TK_EQ) || (pExpr->op==TK_ISNOT && op==TK_NE) ); assert( p5==0 || pExpr->op!=op ); assert( p5==SQLITE_NULLEQ || pExpr->op==op ); p5 |= SQLITE_STOREP2; if( opx==TK_LE ) opx = TK_LT; if( opx==TK_GE ) opx = TK_GT; regLeft = exprCodeSubselect(pParse, pLeft); regRight = exprCodeSubselect(pParse, pRight); for(i=0; 1 /*Loop exits by "break"*/; i++){ int regFree1 = 0, regFree2 = 0; Expr *pL, *pR; int r1, r2; assert( i>=0 && i0 /* ** 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; inExpr; i++){ heightOfExpr(p->a[i].pExpr, pnHeight); } } } static void heightOfSelect(Select *pSelect, int *pnHeight){ Select *p; for(p=pSelect; p; p=p->pPrior){ heightOfExpr(p->pWhere, pnHeight); heightOfExpr(p->pHaving, pnHeight); heightOfExpr(p->pLimit, pnHeight); heightOfExprList(p->pEList, pnHeight); heightOfExprList(p->pGroupBy, pnHeight); heightOfExprList(p->pOrderBy, 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. ** ** Also propagate EP_Propagate flags up from Expr.x.pList to Expr.flags, ** if appropriate. */ 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 if( p->x.pList ){ heightOfExprList(p->x.pList, &nHeight); p->flags |= EP_Propagate & sqlite3ExprListFlags(p->x.pList); } 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. ** ** Also propagate all EP_Propagate flags from the Expr.x.pList into ** Expr.flags. */ void sqlite3ExprSetHeightAndFlags(Parse *pParse, Expr *p){ if( pParse->nErr ) return; 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 /* ABOVE: Height enforcement enabled. BELOW: Height enforcement off */ /* ** Propagate all EP_Propagate flags from the Expr.x.pList into ** Expr.flags. */ void sqlite3ExprSetHeightAndFlags(Parse *pParse, Expr *p){ if( p && p->x.pList && !ExprHasProperty(p, EP_xIsSelect) ){ p->flags |= EP_Propagate & sqlite3ExprListFlags(p->x.pList); } } #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 performed. 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 sqlite3DbMallocRawNN() */ 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; assert( db!=0 ); if( pToken ){ if( op!=TK_INTEGER || pToken->z==0 || sqlite3GetInt32(pToken->z, &iValue)==0 ){ nExtra = pToken->n+1; assert( iValue>=0 ); } } pNew = sqlite3DbMallocRawNN(db, sizeof(Expr)+nExtra); if( pNew ){ memset(pNew, 0, sizeof(Expr)); pNew->op = (u8)op; pNew->iAgg = -1; if( pToken ){ if( nExtra==0 ){ pNew->flags |= EP_IntValue|EP_Leaf|(iValue?EP_IsTrue:EP_IsFalse); pNew->u.iValue = iValue; }else{ 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 && sqlite3Isquote(pNew->u.zToken[0]) ){ sqlite3DequoteExpr(pNew); } } } #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 = sqlite3Strlen30(zToken); 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_Propagate & pRight->flags; } if( pLeft ){ pRoot->pLeft = pLeft; pRoot->flags |= EP_Propagate & pLeft->flags; } exprSetHeight(pRoot); } } /* ** Allocate an 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 */ ){ Expr *p; p = sqlite3DbMallocRawNN(pParse->db, sizeof(Expr)); if( p ){ memset(p, 0, sizeof(Expr)); p->op = op & 0xff; p->iAgg = -1; sqlite3ExprAttachSubtrees(pParse->db, p, pLeft, pRight); sqlite3ExprCheckHeight(pParse, p->nHeight); }else{ sqlite3ExprDelete(pParse->db, pLeft); sqlite3ExprDelete(pParse->db, pRight); } return p; } /* ** Add pSelect to the Expr.x.pSelect field. Or, if pExpr is NULL (due ** do a memory allocation failure) then delete the pSelect object. */ void sqlite3PExprAddSelect(Parse *pParse, Expr *pExpr, Select *pSelect){ if( pExpr ){ pExpr->x.pSelect = pSelect; ExprSetProperty(pExpr, EP_xIsSelect|EP_Subquery); sqlite3ExprSetHeightAndFlags(pParse, pExpr); }else{ assert( pParse->db->mallocFailed ); sqlite3SelectDelete(pParse->db, pSelect); } } /* ** 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(Parse *pParse, Expr *pLeft, Expr *pRight){ sqlite3 *db = pParse->db; if( pLeft==0 ){ return pRight; }else if( pRight==0 ){ return pLeft; }else if( ExprAlwaysFalse(pLeft) || ExprAlwaysFalse(pRight) ){ sqlite3ExprUnmapAndDelete(pParse, pLeft); sqlite3ExprUnmapAndDelete(pParse, pRight); return sqlite3ExprAlloc(db, TK_INTEGER, &sqlite3IntTokens[0], 0); }else{ return sqlite3PExpr(pParse, TK_AND, pLeft, pRight); } } /* ** Construct a new expression node for a function with multiple ** arguments. */ Expr *sqlite3ExprFunction( Parse *pParse, /* Parsing context */ ExprList *pList, /* Argument list */ Token *pToken, /* Name of the function */ int eDistinct /* SF_Distinct or SF_ALL or 0 */ ){ 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; } if( pList && pList->nExpr > pParse->db->aLimit[SQLITE_LIMIT_FUNCTION_ARG] ){ sqlite3ErrorMsg(pParse, "too many arguments on function %T", pToken); } pNew->x.pList = pList; ExprSetProperty(pNew, EP_HasFunc); assert( !ExprHasProperty(pNew, EP_xIsSelect) ); sqlite3ExprSetHeightAndFlags(pParse, pNew); if( eDistinct==SF_Distinct ) ExprSetProperty(pNew, EP_Distinct); 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 big to avoid a denial of service attack when ** the SQL statement comes from an external source. ** ** Wildcards of the form ":aaa", "@aaa", or "$aaa" are assigned the same number ** as the previous instance of the same wildcard. Or if this is the first ** instance of the wildcard, the next sequential variable number is ** assigned. */ void sqlite3ExprAssignVarNumber(Parse *pParse, Expr *pExpr, u32 n){ sqlite3 *db = pParse->db; const char *z; ynVar x; if( pExpr==0 ) return; assert( !ExprHasProperty(pExpr, EP_IntValue|EP_Reduced|EP_TokenOnly) ); z = pExpr->u.zToken; assert( z!=0 ); assert( z[0]!=0 ); assert( n==(u32)sqlite3Strlen30(z) ); if( z[1]==0 ){ /* Wildcard of the form "?". Assign the next variable number */ assert( z[0]=='?' ); x = (ynVar)(++pParse->nVar); }else{ int doAdd = 0; if( z[0]=='?' ){ /* Wildcard of the form "?nnn". Convert "nnn" to an integer and ** use it as the variable number */ i64 i; int bOk; if( n==2 ){ /*OPTIMIZATION-IF-TRUE*/ i = z[1]-'0'; /* The common case of ?N for a single digit N */ bOk = 1; }else{ bOk = 0==sqlite3Atoi64(&z[1], &i, n-1, SQLITE_UTF8); } testcase( i==0 ); testcase( i==1 ); testcase( i==db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER]-1 ); testcase( i==db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER] ); if( bOk==0 || i<1 || i>db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER] ){ sqlite3ErrorMsg(pParse, "variable number must be between ?1 and ?%d", db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER]); return; } x = (ynVar)i; if( x>pParse->nVar ){ pParse->nVar = (int)x; doAdd = 1; }else if( sqlite3VListNumToName(pParse->pVList, x)==0 ){ doAdd = 1; } }else{ /* Wildcards like ":aaa", "$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 */ x = (ynVar)sqlite3VListNameToNum(pParse->pVList, z, n); if( x==0 ){ x = (ynVar)(++pParse->nVar); doAdd = 1; } } if( doAdd ){ pParse->pVList = sqlite3VListAdd(db, pParse->pVList, z, n, x); } } pExpr->iColumn = x; if( x>db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER] ){ sqlite3ErrorMsg(pParse, "too many SQL variables"); } } /* ** Recursively delete an expression tree. */ static SQLITE_NOINLINE void sqlite3ExprDeleteNN(sqlite3 *db, Expr *p){ assert( p!=0 ); /* Sanity check: Assert that the IntValue is non-negative if it exists */ assert( !ExprHasProperty(p, EP_IntValue) || p->u.iValue>=0 ); assert( !ExprHasProperty(p, EP_WinFunc) || p->y.pWin!=0 || db->mallocFailed ); assert( p->op!=TK_FUNCTION || ExprHasProperty(p, EP_TokenOnly|EP_Reduced) || p->y.pWin==0 || ExprHasProperty(p, EP_WinFunc|EP_Filter) ); #ifdef SQLITE_DEBUG if( ExprHasProperty(p, EP_Leaf) && !ExprHasProperty(p, EP_TokenOnly) ){ assert( p->pLeft==0 ); assert( p->pRight==0 ); assert( p->x.pSelect==0 ); } #endif if( !ExprHasProperty(p, (EP_TokenOnly|EP_Leaf)) ){ /* The Expr.x union is never used at the same time as Expr.pRight */ assert( p->x.pList==0 || p->pRight==0 ); if( p->pLeft && p->op!=TK_SELECT_COLUMN ) sqlite3ExprDeleteNN(db, p->pLeft); if( p->pRight ){ assert( !ExprHasProperty(p, (EP_WinFunc|EP_Filter)) ); sqlite3ExprDeleteNN(db, p->pRight); }else if( ExprHasProperty(p, EP_xIsSelect) ){ assert( !ExprHasProperty(p, (EP_WinFunc|EP_Filter)) ); sqlite3SelectDelete(db, p->x.pSelect); }else{ sqlite3ExprListDelete(db, p->x.pList); #ifndef SQLITE_OMIT_WINDOWFUNC if( ExprHasProperty(p, (EP_WinFunc|EP_Filter)) ){ if( ExprHasProperty(p, EP_WinFunc) ){ assert( p->op==TK_FUNCTION && !ExprHasProperty(p, EP_Filter) ); sqlite3WindowDelete(db, p->y.pWin); }else{ assert( p->op==TK_FUNCTION || p->op==TK_AGG_FUNCTION ); sqlite3ExprDeleteNN(db, p->y.pFilter); } } #endif } } if( ExprHasProperty(p, EP_MemToken) ) sqlite3DbFree(db, p->u.zToken); if( !ExprHasProperty(p, EP_Static) ){ sqlite3DbFreeNN(db, p); } } void sqlite3ExprDelete(sqlite3 *db, Expr *p){ if( p ) sqlite3ExprDeleteNN(db, p); } /* Invoke sqlite3RenameExprUnmap() and sqlite3ExprDelete() on the ** expression. */ void sqlite3ExprUnmapAndDelete(Parse *pParse, Expr *p){ if( p ){ if( IN_RENAME_OBJECT ){ sqlite3RenameExprUnmap(pParse, p); } sqlite3ExprDeleteNN(pParse->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; } /* ** Copy the complete content of an Expr node, taking care not to read ** past the end of the structure for a reduced-size version of the source ** Expr. */ static void exprNodeCopy(Expr *pDest, Expr *pSrc){ memset(pDest, 0, sizeof(Expr)); memcpy(pDest, pSrc, exprStructSize(pSrc)); } /* ** 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 the Expr object and that extra information might get chopped ** off if the expression is reduced. Note also that it does not work to ** make an 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 || p->op==TK_SELECT_COLUMN #ifndef SQLITE_OMIT_WINDOWFUNC || ExprHasProperty(p, EP_WinFunc) #endif ){ 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 += sqlite3Strlen30NN(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 past the ** portion of the buffer copied into by this function. */ static Expr *exprDup(sqlite3 *db, Expr *p, int dupFlags, u8 **pzBuffer){ Expr *pNew; /* Value to return */ u8 *zAlloc; /* Memory space from which to build Expr object */ u32 staticFlag; /* EP_Static if space not obtained from malloc */ assert( db!=0 ); assert( p ); assert( dupFlags==0 || dupFlags==EXPRDUP_REDUCE ); assert( pzBuffer==0 || dupFlags==EXPRDUP_REDUCE ); /* Figure out where to write the new Expr structure. */ if( pzBuffer ){ zAlloc = *pzBuffer; staticFlag = EP_Static; }else{ zAlloc = sqlite3DbMallocRawNN(db, dupedExprSize(p, dupFlags)); staticFlag = 0; } 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, dupFlags); 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( dupFlags ){ assert( ExprHasProperty(p, EP_Reduced)==0 ); memcpy(zAlloc, p, nNewSize); }else{ u32 nSize = (u32)exprStructSize(p); memcpy(zAlloc, p, nSize); if( nSizeflags &= ~(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|EP_Leaf)) ){ /* Fill in the pNew->x.pSelect or pNew->x.pList member. */ if( ExprHasProperty(p, EP_xIsSelect) ){ pNew->x.pSelect = sqlite3SelectDup(db, p->x.pSelect, dupFlags); }else{ pNew->x.pList = sqlite3ExprListDup(db, p->x.pList, dupFlags); } } /* Fill in pNew->pLeft and pNew->pRight. */ if( ExprHasProperty(pNew, EP_Reduced|EP_TokenOnly|EP_WinFunc|EP_Filter) ){ zAlloc += dupedExprNodeSize(p, dupFlags); if( !ExprHasProperty(pNew, EP_TokenOnly|EP_Leaf) ){ pNew->pLeft = p->pLeft ? exprDup(db, p->pLeft, EXPRDUP_REDUCE, &zAlloc) : 0; pNew->pRight = p->pRight ? exprDup(db, p->pRight, EXPRDUP_REDUCE, &zAlloc) : 0; } #ifndef SQLITE_OMIT_WINDOWFUNC if( ExprHasProperty(p, EP_WinFunc) ){ pNew->y.pWin = sqlite3WindowDup(db, pNew, p->y.pWin); assert( ExprHasProperty(pNew, EP_WinFunc) ); } if( ExprHasProperty(p, EP_Filter) ){ pNew->y.pFilter = sqlite3ExprDup(db, p->y.pFilter, 0); assert( ExprHasProperty(pNew, EP_Filter) ); } #endif /* SQLITE_OMIT_WINDOWFUNC */ if( pzBuffer ){ *pzBuffer = zAlloc; } }else{ if( !ExprHasProperty(p, EP_TokenOnly|EP_Leaf) ){ if( pNew->op==TK_SELECT_COLUMN ){ pNew->pLeft = p->pLeft; assert( p->iColumn==0 || p->pRight==0 ); assert( p->pRight==0 || p->pRight==p->pLeft ); }else{ pNew->pLeft = sqlite3ExprDup(db, p->pLeft, 0); } pNew->pRight = sqlite3ExprDup(db, p->pRight, 0); } } } return pNew; } /* ** Create and return a deep copy of the object passed as the second ** argument. If an OOM condition is encountered, NULL is returned ** and the db->mallocFailed flag set. */ #ifndef SQLITE_OMIT_CTE static With *withDup(sqlite3 *db, With *p){ With *pRet = 0; if( p ){ sqlite3_int64 nByte = sizeof(*p) + sizeof(p->a[0]) * (p->nCte-1); pRet = sqlite3DbMallocZero(db, nByte); if( pRet ){ int i; pRet->nCte = p->nCte; for(i=0; inCte; i++){ pRet->a[i].pSelect = sqlite3SelectDup(db, p->a[i].pSelect, 0); pRet->a[i].pCols = sqlite3ExprListDup(db, p->a[i].pCols, 0); pRet->a[i].zName = sqlite3DbStrDup(db, p->a[i].zName); } } } return pRet; } #else # define withDup(x,y) 0 #endif #ifndef SQLITE_OMIT_WINDOWFUNC /* ** The gatherSelectWindows() procedure and its helper routine ** gatherSelectWindowsCallback() are used to scan all the expressions ** an a newly duplicated SELECT statement and gather all of the Window ** objects found there, assembling them onto the linked list at Select->pWin. */ static int gatherSelectWindowsCallback(Walker *pWalker, Expr *pExpr){ if( pExpr->op==TK_FUNCTION && ExprHasProperty(pExpr, EP_WinFunc) ){ assert( pExpr->y.pWin ); pExpr->y.pWin->pNextWin = pWalker->u.pSelect->pWin; pWalker->u.pSelect->pWin = pExpr->y.pWin; } return WRC_Continue; } static int gatherSelectWindowsSelectCallback(Walker *pWalker, Select *p){ return p==pWalker->u.pSelect ? WRC_Continue : WRC_Prune; } static void gatherSelectWindows(Select *p){ Walker w; w.xExprCallback = gatherSelectWindowsCallback; w.xSelectCallback = gatherSelectWindowsSelectCallback; w.xSelectCallback2 = 0; w.pParse = 0; w.u.pSelect = p; sqlite3WalkSelect(&w, p); } #endif /* ** 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){ assert( flags==0 || flags==EXPRDUP_REDUCE ); return p ? exprDup(db, p, flags, 0) : 0; } ExprList *sqlite3ExprListDup(sqlite3 *db, ExprList *p, int flags){ ExprList *pNew; struct ExprList_item *pItem, *pOldItem; int i; Expr *pPriorSelectCol = 0; assert( db!=0 ); if( p==0 ) return 0; pNew = sqlite3DbMallocRawNN(db, sqlite3DbMallocSize(db, p)); if( pNew==0 ) return 0; pNew->nExpr = p->nExpr; pItem = pNew->a; pOldItem = p->a; for(i=0; inExpr; i++, pItem++, pOldItem++){ Expr *pOldExpr = pOldItem->pExpr; Expr *pNewExpr; pItem->pExpr = sqlite3ExprDup(db, pOldExpr, flags); if( pOldExpr && pOldExpr->op==TK_SELECT_COLUMN && (pNewExpr = pItem->pExpr)!=0 ){ assert( pNewExpr->iColumn==0 || i>0 ); if( pNewExpr->iColumn==0 ){ assert( pOldExpr->pLeft==pOldExpr->pRight ); pPriorSelectCol = pNewExpr->pLeft = pNewExpr->pRight; }else{ assert( i>0 ); assert( pItem[-1].pExpr!=0 ); assert( pNewExpr->iColumn==pItem[-1].pExpr->iColumn+1 ); assert( pPriorSelectCol==pItem[-1].pExpr->pLeft ); pNewExpr->pLeft = pPriorSelectCol; } } pItem->zName = sqlite3DbStrDup(db, pOldItem->zName); pItem->zSpan = sqlite3DbStrDup(db, pOldItem->zSpan); pItem->sortOrder = pOldItem->sortOrder; pItem->done = 0; pItem->bSpanIsTab = pOldItem->bSpanIsTab; pItem->bSorterRef = pOldItem->bSorterRef; pItem->u = pOldItem->u; } 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; assert( db!=0 ); if( p==0 ) return 0; nByte = sizeof(*p) + (p->nSrc>0 ? sizeof(p->a[0]) * (p->nSrc-1) : 0); pNew = sqlite3DbMallocRawNN(db, nByte ); if( pNew==0 ) return 0; pNew->nSrc = pNew->nAlloc = p->nSrc; for(i=0; inSrc; 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->fg = pOldItem->fg; pNewItem->iCursor = pOldItem->iCursor; pNewItem->addrFillSub = pOldItem->addrFillSub; pNewItem->regReturn = pOldItem->regReturn; if( pNewItem->fg.isIndexedBy ){ pNewItem->u1.zIndexedBy = sqlite3DbStrDup(db, pOldItem->u1.zIndexedBy); } pNewItem->pIBIndex = pOldItem->pIBIndex; if( pNewItem->fg.isTabFunc ){ pNewItem->u1.pFuncArg = sqlite3ExprListDup(db, pOldItem->u1.pFuncArg, flags); } pTab = pNewItem->pTab = pOldItem->pTab; if( pTab ){ pTab->nTabRef++; } 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; assert( db!=0 ); if( p==0 ) return 0; pNew = sqlite3DbMallocRawNN(db, sizeof(*pNew) ); if( pNew==0 ) return 0; pNew->nId = p->nId; pNew->a = sqlite3DbMallocRawNN(db, p->nId*sizeof(p->a[0]) ); if( pNew->a==0 ){ sqlite3DbFreeNN(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; inId; 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 *pDup, int flags){ Select *pRet = 0; Select *pNext = 0; Select **pp = &pRet; Select *p; assert( db!=0 ); for(p=pDup; p; p=p->pPrior){ Select *pNew = sqlite3DbMallocRawNN(db, sizeof(*p) ); if( pNew==0 ) break; 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->pNext = pNext; pNew->pPrior = 0; pNew->pLimit = sqlite3ExprDup(db, p->pLimit, flags); pNew->iLimit = 0; pNew->iOffset = 0; pNew->selFlags = p->selFlags & ~SF_UsesEphemeral; pNew->addrOpenEphm[0] = -1; pNew->addrOpenEphm[1] = -1; pNew->nSelectRow = p->nSelectRow; pNew->pWith = withDup(db, p->pWith); #ifndef SQLITE_OMIT_WINDOWFUNC pNew->pWin = 0; pNew->pWinDefn = sqlite3WindowListDup(db, p->pWinDefn); if( p->pWin ) gatherSelectWindows(pNew); #endif pNew->selId = p->selId; *pp = pNew; pp = &pNew->pPrior; pNext = pNew; } return pRet; } #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. ** ** The pList argument must be either NULL or a pointer to an ExprList ** obtained from a prior call to sqlite3ExprListAppend(). This routine ** may not be used with an ExprList obtained from sqlite3ExprListDup(). ** Reason: This routine assumes that the number of slots in pList->a[] ** is a power of two. That is true for sqlite3ExprListAppend() returns ** but is not necessarily true from the return value of sqlite3ExprListDup(). ** ** 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 */ ){ struct ExprList_item *pItem; sqlite3 *db = pParse->db; assert( db!=0 ); if( pList==0 ){ pList = sqlite3DbMallocRawNN(db, sizeof(ExprList) ); if( pList==0 ){ goto no_mem; } pList->nExpr = 0; }else if( (pList->nExpr & (pList->nExpr-1))==0 ){ ExprList *pNew; pNew = sqlite3DbRealloc(db, pList, sizeof(*pList)+(2*(sqlite3_int64)pList->nExpr-1)*sizeof(pList->a[0])); if( pNew==0 ){ goto no_mem; } pList = pNew; } pItem = &pList->a[pList->nExpr++]; assert( offsetof(struct ExprList_item,zName)==sizeof(pItem->pExpr) ); assert( offsetof(struct ExprList_item,pExpr)==0 ); memset(&pItem->zName,0,sizeof(*pItem)-offsetof(struct ExprList_item,zName)); pItem->pExpr = pExpr; return pList; no_mem: /* Avoid leaking memory if malloc has failed. */ sqlite3ExprDelete(db, pExpr); sqlite3ExprListDelete(db, pList); return 0; } /* ** pColumns and pExpr form a vector assignment which is part of the SET ** clause of an UPDATE statement. Like this: ** ** (a,b,c) = (expr1,expr2,expr3) ** Or: (a,b,c) = (SELECT x,y,z FROM ....) ** ** For each term of the vector assignment, append new entries to the ** expression list pList. In the case of a subquery on the RHS, append ** TK_SELECT_COLUMN expressions. */ ExprList *sqlite3ExprListAppendVector( Parse *pParse, /* Parsing context */ ExprList *pList, /* List to which to append. Might be NULL */ IdList *pColumns, /* List of names of LHS of the assignment */ Expr *pExpr /* Vector expression to be appended. Might be NULL */ ){ sqlite3 *db = pParse->db; int n; int i; int iFirst = pList ? pList->nExpr : 0; /* pColumns can only be NULL due to an OOM but an OOM will cause an ** exit prior to this routine being invoked */ if( NEVER(pColumns==0) ) goto vector_append_error; if( pExpr==0 ) goto vector_append_error; /* If the RHS is a vector, then we can immediately check to see that ** the size of the RHS and LHS match. But if the RHS is a SELECT, ** wildcards ("*") in the result set of the SELECT must be expanded before ** we can do the size check, so defer the size check until code generation. */ if( pExpr->op!=TK_SELECT && pColumns->nId!=(n=sqlite3ExprVectorSize(pExpr)) ){ sqlite3ErrorMsg(pParse, "%d columns assigned %d values", pColumns->nId, n); goto vector_append_error; } for(i=0; inId; i++){ Expr *pSubExpr = sqlite3ExprForVectorField(pParse, pExpr, i); pList = sqlite3ExprListAppend(pParse, pList, pSubExpr); if( pList ){ assert( pList->nExpr==iFirst+i+1 ); pList->a[pList->nExpr-1].zName = pColumns->a[i].zName; pColumns->a[i].zName = 0; } } if( !db->mallocFailed && pExpr->op==TK_SELECT && ALWAYS(pList!=0) ){ Expr *pFirst = pList->a[iFirst].pExpr; assert( pFirst!=0 ); assert( pFirst->op==TK_SELECT_COLUMN ); /* Store the SELECT statement in pRight so it will be deleted when ** sqlite3ExprListDelete() is called */ pFirst->pRight = pExpr; pExpr = 0; /* Remember the size of the LHS in iTable so that we can check that ** the RHS and LHS sizes match during code generation. */ pFirst->iTable = pColumns->nId; } vector_append_error: sqlite3ExprUnmapAndDelete(pParse, pExpr); sqlite3IdListDelete(db, pColumns); return pList; } /* ** Set the sort order for the last element on the given ExprList. */ void sqlite3ExprListSetSortOrder(ExprList *p, int iSortOrder){ if( p==0 ) return; assert( SQLITE_SO_UNDEFINED<0 && SQLITE_SO_ASC>=0 && SQLITE_SO_DESC>0 ); assert( p->nExpr>0 ); if( iSortOrder<0 ){ assert( p->a[p->nExpr-1].sortOrder==SQLITE_SO_ASC ); return; } p->a[p->nExpr-1].sortOrder = (u8)iSortOrder; } /* ** 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 ) sqlite3Dequote(pItem->zName); if( IN_RENAME_OBJECT ){ sqlite3RenameTokenMap(pParse, (void*)pItem->zName, pName); } } } /* ** 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. */ const char *zStart, /* Start of the span */ const char *zEnd /* End of the span */ ){ 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 ); sqlite3DbFree(db, pItem->zSpan); pItem->zSpan = sqlite3DbSpanDup(db, zStart, zEnd); } } /* ** 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. */ static SQLITE_NOINLINE void exprListDeleteNN(sqlite3 *db, ExprList *pList){ int i = pList->nExpr; struct ExprList_item *pItem = pList->a; assert( pList->nExpr>0 ); do{ sqlite3ExprDelete(db, pItem->pExpr); sqlite3DbFree(db, pItem->zName); sqlite3DbFree(db, pItem->zSpan); pItem++; }while( --i>0 ); sqlite3DbFreeNN(db, pList); } void sqlite3ExprListDelete(sqlite3 *db, ExprList *pList){ if( pList ) exprListDeleteNN(db, pList); } /* ** Return the bitwise-OR of all Expr.flags fields in the given ** ExprList. */ u32 sqlite3ExprListFlags(const ExprList *pList){ int i; u32 m = 0; assert( pList!=0 ); for(i=0; inExpr; i++){ Expr *pExpr = pList->a[i].pExpr; assert( pExpr!=0 ); m |= pExpr->flags; } return m; } /* ** This is a SELECT-node callback for the expression walker that ** always "fails". By "fail" in this case, we mean set ** pWalker->eCode to zero and abort. ** ** This callback is used by multiple expression walkers. */ int sqlite3SelectWalkFail(Walker *pWalker, Select *NotUsed){ UNUSED_PARAMETER(NotUsed); pWalker->eCode = 0; return WRC_Abort; } /* ** If the input expression is an ID with the name "true" or "false" ** then convert it into an TK_TRUEFALSE term. Return non-zero if ** the conversion happened, and zero if the expression is unaltered. */ int sqlite3ExprIdToTrueFalse(Expr *pExpr){ assert( pExpr->op==TK_ID || pExpr->op==TK_STRING ); if( !ExprHasProperty(pExpr, EP_Quoted) && (sqlite3StrICmp(pExpr->u.zToken, "true")==0 || sqlite3StrICmp(pExpr->u.zToken, "false")==0) ){ pExpr->op = TK_TRUEFALSE; ExprSetProperty(pExpr, pExpr->u.zToken[4]==0 ? EP_IsTrue : EP_IsFalse); return 1; } return 0; } /* ** The argument must be a TK_TRUEFALSE Expr node. Return 1 if it is TRUE ** and 0 if it is FALSE. */ int sqlite3ExprTruthValue(const Expr *pExpr){ pExpr = sqlite3ExprSkipCollate((Expr*)pExpr); assert( pExpr->op==TK_TRUEFALSE ); assert( sqlite3StrICmp(pExpr->u.zToken,"true")==0 || sqlite3StrICmp(pExpr->u.zToken,"false")==0 ); return pExpr->u.zToken[4]==0; } /* ** If pExpr is an AND or OR expression, try to simplify it by eliminating ** terms that are always true or false. Return the simplified expression. ** Or return the original expression if no simplification is possible. ** ** Examples: ** ** (x<10) AND true => (x<10) ** (x<10) AND false => false ** (x<10) AND (y=22 OR false) => (x<10) AND (y=22) ** (x<10) AND (y=22 OR true) => (x<10) ** (y=22) OR true => true */ Expr *sqlite3ExprSimplifiedAndOr(Expr *pExpr){ assert( pExpr!=0 ); if( pExpr->op==TK_AND || pExpr->op==TK_OR ){ Expr *pRight = sqlite3ExprSimplifiedAndOr(pExpr->pRight); Expr *pLeft = sqlite3ExprSimplifiedAndOr(pExpr->pLeft); if( ExprAlwaysTrue(pLeft) || ExprAlwaysFalse(pRight) ){ pExpr = pExpr->op==TK_AND ? pRight : pLeft; }else if( ExprAlwaysTrue(pRight) || ExprAlwaysFalse(pLeft) ){ pExpr = pExpr->op==TK_AND ? pLeft : pRight; } } return pExpr; } /* ** These routines are Walker callbacks used to check expressions to ** see if they are "constant" for some definition of constant. The ** Walker.eCode value determines the type of "constant" we are looking ** for. ** ** These callback routines are used to implement the following: ** ** sqlite3ExprIsConstant() pWalker->eCode==1 ** sqlite3ExprIsConstantNotJoin() pWalker->eCode==2 ** sqlite3ExprIsTableConstant() pWalker->eCode==3 ** sqlite3ExprIsConstantOrFunction() pWalker->eCode==4 or 5 ** ** In all cases, the callbacks set Walker.eCode=0 and abort if the expression ** is found to not be a constant. ** ** The sqlite3ExprIsConstantOrFunction() is used for evaluating expressions ** in a CREATE TABLE statement. The Walker.eCode value is 5 when parsing ** an existing schema and 4 when processing a new statement. A bound ** parameter raises an error for new statements, but is silently converted ** to NULL for existing schemas. This allows sqlite_master tables that ** contain a bound parameter because they were generated by older versions ** of SQLite to be parsed by newer versions of SQLite without raising a ** malformed schema error. */ static int exprNodeIsConstant(Walker *pWalker, Expr *pExpr){ /* If pWalker->eCode is 2 then any term of the expression that comes from ** the ON or USING clauses of a left join disqualifies the expression ** from being considered constant. */ if( pWalker->eCode==2 && ExprHasProperty(pExpr, EP_FromJoin) ){ pWalker->eCode = 0; return WRC_Abort; } switch( pExpr->op ){ /* Consider functions to be constant if all their arguments are constant ** and either pWalker->eCode==4 or 5 or the function has the ** SQLITE_FUNC_CONST flag. */ case TK_FUNCTION: if( pWalker->eCode>=4 || ExprHasProperty(pExpr,EP_ConstFunc) ){ return WRC_Continue; }else{ pWalker->eCode = 0; return WRC_Abort; } case TK_ID: /* Convert "true" or "false" in a DEFAULT clause into the ** appropriate TK_TRUEFALSE operator */ if( sqlite3ExprIdToTrueFalse(pExpr) ){ return WRC_Prune; } /* Fall thru */ 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 ); if( ExprHasProperty(pExpr, EP_FixedCol) && pWalker->eCode!=2 ){ return WRC_Continue; } if( pWalker->eCode==3 && pExpr->iTable==pWalker->u.iCur ){ return WRC_Continue; } /* Fall through */ case TK_IF_NULL_ROW: case TK_REGISTER: testcase( pExpr->op==TK_REGISTER ); testcase( pExpr->op==TK_IF_NULL_ROW ); pWalker->eCode = 0; return WRC_Abort; case TK_VARIABLE: if( pWalker->eCode==5 ){ /* Silently convert bound parameters that appear inside of CREATE ** statements into a NULL when parsing the CREATE statement text out ** of the sqlite_master table */ pExpr->op = TK_NULL; }else if( pWalker->eCode==4 ){ /* A bound parameter in a CREATE statement that originates from ** sqlite3_prepare() causes an error */ pWalker->eCode = 0; return WRC_Abort; } /* Fall through */ default: testcase( pExpr->op==TK_SELECT ); /* sqlite3SelectWalkFail() disallows */ testcase( pExpr->op==TK_EXISTS ); /* sqlite3SelectWalkFail() disallows */ return WRC_Continue; } } static int exprIsConst(Expr *p, int initFlag, int iCur){ Walker w; w.eCode = initFlag; w.xExprCallback = exprNodeIsConstant; w.xSelectCallback = sqlite3SelectWalkFail; #ifdef SQLITE_DEBUG w.xSelectCallback2 = sqlite3SelectWalkAssert2; #endif w.u.iCur = iCur; sqlite3WalkExpr(&w, p); return w.eCode; } /* ** Walk an expression tree. Return non-zero 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, 0); } /* ** Walk an expression tree. Return non-zero if ** ** (1) the expression is constant, and ** (2) the expression does originate in the ON or USING clause ** of a LEFT JOIN, and ** (3) the expression does not contain any EP_FixedCol TK_COLUMN ** operands created by the constant propagation optimization. ** ** When this routine returns true, it indicates that the expression ** can be added to the pParse->pConstExpr list and evaluated once when ** the prepared statement starts up. See sqlite3ExprCodeAtInit(). */ int sqlite3ExprIsConstantNotJoin(Expr *p){ return exprIsConst(p, 2, 0); } /* ** Walk an expression tree. Return non-zero if the expression is constant ** for any single row of the table with cursor iCur. In other words, the ** expression must not refer to any non-deterministic function nor any ** table other than iCur. */ int sqlite3ExprIsTableConstant(Expr *p, int iCur){ return exprIsConst(p, 3, iCur); } /* ** sqlite3WalkExpr() callback used by sqlite3ExprIsConstantOrGroupBy(). */ static int exprNodeIsConstantOrGroupBy(Walker *pWalker, Expr *pExpr){ ExprList *pGroupBy = pWalker->u.pGroupBy; int i; /* Check if pExpr is identical to any GROUP BY term. If so, consider ** it constant. */ for(i=0; inExpr; i++){ Expr *p = pGroupBy->a[i].pExpr; if( sqlite3ExprCompare(0, pExpr, p, -1)<2 ){ CollSeq *pColl = sqlite3ExprNNCollSeq(pWalker->pParse, p); if( sqlite3IsBinary(pColl) ){ return WRC_Prune; } } } /* Check if pExpr is a sub-select. If so, consider it variable. */ if( ExprHasProperty(pExpr, EP_xIsSelect) ){ pWalker->eCode = 0; return WRC_Abort; } return exprNodeIsConstant(pWalker, pExpr); } /* ** Walk the expression tree passed as the first argument. Return non-zero ** if the expression consists entirely of constants or copies of terms ** in pGroupBy that sort with the BINARY collation sequence. ** ** This routine is used to determine if a term of the HAVING clause can ** be promoted into the WHERE clause. In order for such a promotion to work, ** the value of the HAVING clause term must be the same for all members of ** a "group". The requirement that the GROUP BY term must be BINARY ** assumes that no other collating sequence will have a finer-grained ** grouping than binary. In other words (A=B COLLATE binary) implies ** A=B in every other collating sequence. The requirement that the ** GROUP BY be BINARY is stricter than necessary. It would also work ** to promote HAVING clauses that use the same alternative collating ** sequence as the GROUP BY term, but that is much harder to check, ** alternative collating sequences are uncommon, and this is only an ** optimization, so we take the easy way out and simply require the ** GROUP BY to use the BINARY collating sequence. */ int sqlite3ExprIsConstantOrGroupBy(Parse *pParse, Expr *p, ExprList *pGroupBy){ Walker w; w.eCode = 1; w.xExprCallback = exprNodeIsConstantOrGroupBy; w.xSelectCallback = 0; w.u.pGroupBy = pGroupBy; w.pParse = pParse; sqlite3WalkExpr(&w, p); return w.eCode; } /* ** Walk an expression tree. Return non-zero 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, u8 isInit){ assert( isInit==0 || isInit==1 ); return exprIsConst(p, 4+isInit, 0); } #ifdef SQLITE_ENABLE_CURSOR_HINTS /* ** Walk an expression tree. Return 1 if the expression contains a ** subquery of some kind. Return 0 if there are no subqueries. */ int sqlite3ExprContainsSubquery(Expr *p){ Walker w; w.eCode = 1; w.xExprCallback = sqlite3ExprWalkNoop; w.xSelectCallback = sqlite3SelectWalkFail; #ifdef SQLITE_DEBUG w.xSelectCallback2 = sqlite3SelectWalkAssert2; #endif sqlite3WalkExpr(&w, p); return w.eCode==0; } #endif /* ** 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( NEVER(p==0) ) return 0; /* Used to only happen following on OOM */ /* 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; case TK_COLUMN: return ExprHasProperty(p, EP_CanBeNull) || p->y.pTab==0 || /* Reference to column of index on expression */ (p->iColumn>=0 && p->y.pTab->aCol[p->iColumn].notNull==0); default: return 1; } } /* ** 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_BLOB ) 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; } /* ** pX is the RHS of an IN operator. If pX is a SELECT statement ** that can be simplified to a direct table access, then return ** a pointer to the SELECT statement. If pX is not a SELECT statement, ** or if the SELECT statement needs to be manifested into a transient ** table, then return NULL. */ #ifndef SQLITE_OMIT_SUBQUERY static Select *isCandidateForInOpt(Expr *pX){ Select *p; SrcList *pSrc; ExprList *pEList; Table *pTab; int i; if( !ExprHasProperty(pX, EP_xIsSelect) ) return 0; /* Not a subquery */ if( ExprHasProperty(pX, EP_VarSelect) ) return 0; /* Correlated subq */ p = pX->x.pSelect; 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 */ 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; assert( pTab!=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; assert( pEList!=0 ); /* All SELECT results must be columns. */ for(i=0; inExpr; i++){ Expr *pRes = pEList->a[i].pExpr; if( pRes->op!=TK_COLUMN ) return 0; assert( pRes->iTable==pSrc->a[0].iCursor ); /* Not a correlated subquery */ } return p; } #endif /* SQLITE_OMIT_SUBQUERY */ #ifndef SQLITE_OMIT_SUBQUERY /* ** Generate code that checks the left-most column of index table iCur to see if ** it contains any NULL entries. Cause the register at regHasNull to be set ** to a non-NULL value if iCur contains no NULLs. Cause register regHasNull ** to be set to NULL if iCur contains one or more NULL values. */ static void sqlite3SetHasNullFlag(Vdbe *v, int iCur, int regHasNull){ int addr1; sqlite3VdbeAddOp2(v, OP_Integer, 0, regHasNull); addr1 = sqlite3VdbeAddOp1(v, OP_Rewind, iCur); VdbeCoverage(v); sqlite3VdbeAddOp3(v, OP_Column, iCur, 0, regHasNull); sqlite3VdbeChangeP5(v, OPFLAG_TYPEOFARG); VdbeComment((v, "first_entry_in(%d)", iCur)); sqlite3VdbeJumpHere(v, addr1); } #endif #ifndef SQLITE_OMIT_SUBQUERY /* ** The argument is an IN operator with a list (not a subquery) on the ** right-hand side. Return TRUE if that list is constant. */ static int sqlite3InRhsIsConstant(Expr *pIn){ Expr *pLHS; int res; assert( !ExprHasProperty(pIn, EP_xIsSelect) ); pLHS = pIn->pLeft; pIn->pLeft = 0; res = sqlite3ExprIsConstant(pIn); pIn->pLeft = pLHS; return res; } #endif /* ** 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 is 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. ** IN_INDEX_NOOP - No cursor was allocated. The IN operator must be ** implemented as a sequence of comparisons. ** ** An existing b-tree might be used if the RHS expression pX is a simple ** subquery such as: ** ** SELECT , ... FROM ** ** 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 ephemeral table instead of an ** existing table. ** ** The inFlags parameter must contain, at a minimum, one of the bits ** IN_INDEX_MEMBERSHIP or IN_INDEX_LOOP but not both. If inFlags contains ** IN_INDEX_MEMBERSHIP, then the generated table will be used for a fast ** membership test. When the IN_INDEX_LOOP bit is set, the IN index will ** be used to loop over all values of the RHS of the IN operator. ** ** When IN_INDEX_LOOP is used (and the b-tree will be used to iterate ** through the set members) then the b-tree must not contain duplicates. ** An epheremal table will be created unless the selected columns are guaranteed ** to be unique - either because it is an INTEGER PRIMARY KEY or due to ** a UNIQUE constraint or index. ** ** When IN_INDEX_MEMBERSHIP is used (and the b-tree will be used ** for fast set membership tests) then an epheremal table must ** be used unless is a single INTEGER PRIMARY KEY column or an ** index can be found with the specified as its left-most. ** ** If the IN_INDEX_NOOP_OK and IN_INDEX_MEMBERSHIP are both set and ** if the RHS of the IN operator is a list (not a subquery) then this ** routine might decide that creating an ephemeral b-tree for membership ** testing is too expensive and return IN_INDEX_NOOP. In that case, the ** calling routine should implement the IN operator using a sequence ** of Eq or Ne comparison operations. ** ** When the b-tree is being used for membership tests, the calling function ** might need to know whether or not the RHS side of the IN operator ** contains a NULL. If prRhsHasNull is not a NULL pointer and ** 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 *prRhsHasNull. If there is no chance that the (...) contains a ** NULL value, then *prRhsHasNull is left unchanged. ** ** If a register is allocated and its location stored in *prRhsHasNull, then ** the value in that register will be NULL if the b-tree contains one or more ** NULL values, and it will be some non-NULL value if the b-tree contains no ** NULL values. ** ** If the aiMap parameter is not NULL, it must point to an array containing ** one element for each column returned by the SELECT statement on the RHS ** of the IN(...) operator. The i'th entry of the array is populated with the ** offset of the index column that matches the i'th column returned by the ** SELECT. For example, if the expression and selected index are: ** ** (?,?,?) IN (SELECT a, b, c FROM t1) ** CREATE INDEX i1 ON t1(b, c, a); ** ** then aiMap[] is populated with {2, 0, 1}. */ #ifndef SQLITE_OMIT_SUBQUERY int sqlite3FindInIndex( Parse *pParse, /* Parsing context */ Expr *pX, /* The right-hand side (RHS) of the IN operator */ u32 inFlags, /* IN_INDEX_LOOP, _MEMBERSHIP, and/or _NOOP_OK */ int *prRhsHasNull, /* Register holding NULL status. See notes */ int *aiMap, /* Mapping from Index fields to RHS fields */ int *piTab /* OUT: index to use */ ){ 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; /* True if RHS must be unique */ Vdbe *v = sqlite3GetVdbe(pParse); /* Virtual machine being coded */ assert( pX->op==TK_IN ); mustBeUnique = (inFlags & IN_INDEX_LOOP)!=0; /* If the RHS of this IN(...) operator is a SELECT, and if it matters ** whether or not the SELECT result contains NULL values, check whether ** or not NULL is actually possible (it may not be, for example, due ** to NOT NULL constraints in the schema). If no NULL values are possible, ** set prRhsHasNull to 0 before continuing. */ if( prRhsHasNull && (pX->flags & EP_xIsSelect) ){ int i; ExprList *pEList = pX->x.pSelect->pEList; for(i=0; inExpr; i++){ if( sqlite3ExprCanBeNull(pEList->a[i].pExpr) ) break; } if( i==pEList->nExpr ){ prRhsHasNull = 0; } } /* 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. */ if( pParse->nErr==0 && (p = isCandidateForInOpt(pX))!=0 ){ sqlite3 *db = pParse->db; /* Database connection */ Table *pTab; /* Table
. */ i16 iDb; /* Database idx for pTab */ ExprList *pEList = p->pEList; int nExpr = pEList->nExpr; 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; /* Code an OP_Transaction and OP_TableLock for
. */ iDb = sqlite3SchemaToIndex(db, pTab->pSchema); sqlite3CodeVerifySchema(pParse, iDb); sqlite3TableLock(pParse, iDb, pTab->tnum, 0, pTab->zName); assert(v); /* sqlite3GetVdbe() has always been previously called */ if( nExpr==1 && pEList->a[0].pExpr->iColumn<0 ){ /* The "x IN (SELECT rowid FROM table)" case */ int iAddr = sqlite3VdbeAddOp0(v, OP_Once); VdbeCoverage(v); sqlite3OpenTable(pParse, iTab, iDb, pTab, OP_OpenRead); eType = IN_INDEX_ROWID; ExplainQueryPlan((pParse, 0, "USING ROWID SEARCH ON TABLE %s FOR IN-OPERATOR",pTab->zName)); sqlite3VdbeJumpHere(v, iAddr); }else{ Index *pIdx; /* Iterator variable */ int affinity_ok = 1; int i; /* Check that the affinity that will be used to perform each ** comparison is the same as the affinity of each column in table ** on the RHS of the IN operator. If it not, it is not possible to ** use any index of the RHS table. */ for(i=0; ipLeft, i); int iCol = pEList->a[i].pExpr->iColumn; char idxaff = sqlite3TableColumnAffinity(pTab,iCol); /* RHS table */ char cmpaff = sqlite3CompareAffinity(pLhs, idxaff); testcase( cmpaff==SQLITE_AFF_BLOB ); testcase( cmpaff==SQLITE_AFF_TEXT ); switch( cmpaff ){ case SQLITE_AFF_BLOB: break; case SQLITE_AFF_TEXT: /* sqlite3CompareAffinity() only returns TEXT if one side or the ** other has no affinity and the other side is TEXT. Hence, ** the only way for cmpaff to be TEXT is for idxaff to be TEXT ** and for the term on the LHS of the IN to have no affinity. */ assert( idxaff==SQLITE_AFF_TEXT ); break; default: affinity_ok = sqlite3IsNumericAffinity(idxaff); } } if( affinity_ok ){ /* Search for an existing index that will work for this IN operator */ for(pIdx=pTab->pIndex; pIdx && eType==0; pIdx=pIdx->pNext){ Bitmask colUsed; /* Columns of the index used */ Bitmask mCol; /* Mask for the current column */ if( pIdx->nColumnpPartIdxWhere!=0 ) continue; /* Maximum nColumn is BMS-2, not BMS-1, so that we can compute ** BITMASK(nExpr) without overflowing */ testcase( pIdx->nColumn==BMS-2 ); testcase( pIdx->nColumn==BMS-1 ); if( pIdx->nColumn>=BMS-1 ) continue; if( mustBeUnique ){ if( pIdx->nKeyCol>nExpr ||(pIdx->nColumn>nExpr && !IsUniqueIndex(pIdx)) ){ continue; /* This index is not unique over the IN RHS columns */ } } colUsed = 0; /* Columns of index used so far */ for(i=0; ipLeft, i); Expr *pRhs = pEList->a[i].pExpr; CollSeq *pReq = sqlite3BinaryCompareCollSeq(pParse, pLhs, pRhs); int j; assert( pReq!=0 || pRhs->iColumn==XN_ROWID || pParse->nErr ); for(j=0; jaiColumn[j]!=pRhs->iColumn ) continue; assert( pIdx->azColl[j] ); if( pReq!=0 && sqlite3StrICmp(pReq->zName, pIdx->azColl[j])!=0 ){ continue; } break; } if( j==nExpr ) break; mCol = MASKBIT(j); if( mCol & colUsed ) break; /* Each column used only once */ colUsed |= mCol; if( aiMap ) aiMap[i] = j; } assert( i==nExpr || colUsed!=(MASKBIT(nExpr)-1) ); if( colUsed==(MASKBIT(nExpr)-1) ){ /* If we reach this point, that means the index pIdx is usable */ int iAddr = sqlite3VdbeAddOp0(v, OP_Once); VdbeCoverage(v); ExplainQueryPlan((pParse, 0, "USING INDEX %s FOR IN-OPERATOR",pIdx->zName)); sqlite3VdbeAddOp3(v, OP_OpenRead, iTab, pIdx->tnum, iDb); sqlite3VdbeSetP4KeyInfo(pParse, pIdx); VdbeComment((v, "%s", pIdx->zName)); assert( IN_INDEX_INDEX_DESC == IN_INDEX_INDEX_ASC+1 ); eType = IN_INDEX_INDEX_ASC + pIdx->aSortOrder[0]; if( prRhsHasNull ){ #ifdef SQLITE_ENABLE_COLUMN_USED_MASK i64 mask = (1<nMem; if( nExpr==1 ){ sqlite3SetHasNullFlag(v, iTab, *prRhsHasNull); } } sqlite3VdbeJumpHere(v, iAddr); } } /* End loop over indexes */ } /* End if( affinity_ok ) */ } /* End if not an rowid index */ } /* End attempt to optimize using an index */ /* If no preexisting index is available for the IN clause ** and IN_INDEX_NOOP is an allowed reply ** and the RHS of the IN operator is a list, not a subquery ** and the RHS is not constant or has two or fewer terms, ** then it is not worth creating an ephemeral table to evaluate ** the IN operator so return IN_INDEX_NOOP. */ if( eType==0 && (inFlags & IN_INDEX_NOOP_OK) && !ExprHasProperty(pX, EP_xIsSelect) && (!sqlite3InRhsIsConstant(pX) || pX->x.pList->nExpr<=2) ){ eType = IN_INDEX_NOOP; } if( eType==0 ){ /* Could not find 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( inFlags & IN_INDEX_LOOP ){ pParse->nQueryLoop = 0; }else if( prRhsHasNull ){ *prRhsHasNull = rMayHaveNull = ++pParse->nMem; } assert( pX->op==TK_IN ); sqlite3CodeRhsOfIN(pParse, pX, iTab); if( rMayHaveNull ){ sqlite3SetHasNullFlag(v, iTab, rMayHaveNull); } pParse->nQueryLoop = savedNQueryLoop; } if( aiMap && eType!=IN_INDEX_INDEX_ASC && eType!=IN_INDEX_INDEX_DESC ){ int i, n; n = sqlite3ExprVectorSize(pX->pLeft); for(i=0; ipLeft; int nVal = sqlite3ExprVectorSize(pLeft); Select *pSelect = (pExpr->flags & EP_xIsSelect) ? pExpr->x.pSelect : 0; char *zRet; assert( pExpr->op==TK_IN ); zRet = sqlite3DbMallocRaw(pParse->db, nVal+1); if( zRet ){ int i; for(i=0; ipEList->a[i].pExpr, a); }else{ zRet[i] = a; } } zRet[nVal] = '\0'; } return zRet; } #endif #ifndef SQLITE_OMIT_SUBQUERY /* ** Load the Parse object passed as the first argument with an error ** message of the form: ** ** "sub-select returns N columns - expected M" */ void sqlite3SubselectError(Parse *pParse, int nActual, int nExpect){ const char *zFmt = "sub-select returns %d columns - expected %d"; sqlite3ErrorMsg(pParse, zFmt, nActual, nExpect); } #endif /* ** Expression pExpr is a vector that has been used in a context where ** it is not permitted. If pExpr is a sub-select vector, this routine ** loads the Parse object with a message of the form: ** ** "sub-select returns N columns - expected 1" ** ** Or, if it is a regular scalar vector: ** ** "row value misused" */ void sqlite3VectorErrorMsg(Parse *pParse, Expr *pExpr){ #ifndef SQLITE_OMIT_SUBQUERY if( pExpr->flags & EP_xIsSelect ){ sqlite3SubselectError(pParse, pExpr->x.pSelect->pEList->nExpr, 1); }else #endif { sqlite3ErrorMsg(pParse, "row value misused"); } } #ifndef SQLITE_OMIT_SUBQUERY /* ** Generate code that will construct an ephemeral table containing all terms ** in the RHS of an IN operator. The IN operator can be in either of two ** forms: ** ** 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 is the IN operator. The cursor number for the ** constructed ephermeral table is returned. The first time the ephemeral ** table is computed, the cursor number is also stored in pExpr->iTable, ** however the cursor number returned might not be the same, as it might ** have been duplicated using OP_OpenDup. ** ** If the LHS expression ("x" in the examples) 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. */ void sqlite3CodeRhsOfIN( Parse *pParse, /* Parsing context */ Expr *pExpr, /* The IN operator */ int iTab /* Use this cursor number */ ){ int addrOnce = 0; /* Address of the OP_Once instruction at top */ int addr; /* Address of OP_OpenEphemeral instruction */ Expr *pLeft; /* the LHS of the IN operator */ KeyInfo *pKeyInfo = 0; /* Key information */ int nVal; /* Size of vector pLeft */ Vdbe *v; /* The prepared statement under construction */ v = pParse->pVdbe; assert( v!=0 ); /* The evaluation of the IN must be repeated 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 compute the RHS just once ** and reuse it many names. */ if( !ExprHasProperty(pExpr, EP_VarSelect) && pParse->iSelfTab==0 ){ /* Reuse of the RHS is allowed */ /* If this routine has already been coded, but the previous code ** might not have been invoked yet, so invoke it now as a subroutine. */ if( ExprHasProperty(pExpr, EP_Subrtn) ){ addrOnce = sqlite3VdbeAddOp0(v, OP_Once); VdbeCoverage(v); if( ExprHasProperty(pExpr, EP_xIsSelect) ){ ExplainQueryPlan((pParse, 0, "REUSE LIST SUBQUERY %d", pExpr->x.pSelect->selId)); } sqlite3VdbeAddOp2(v, OP_Gosub, pExpr->y.sub.regReturn, pExpr->y.sub.iAddr); sqlite3VdbeAddOp2(v, OP_OpenDup, iTab, pExpr->iTable); sqlite3VdbeJumpHere(v, addrOnce); return; } /* Begin coding the subroutine */ ExprSetProperty(pExpr, EP_Subrtn); pExpr->y.sub.regReturn = ++pParse->nMem; pExpr->y.sub.iAddr = sqlite3VdbeAddOp2(v, OP_Integer, 0, pExpr->y.sub.regReturn) + 1; VdbeComment((v, "return address")); addrOnce = sqlite3VdbeAddOp0(v, OP_Once); VdbeCoverage(v); } /* Check to see if this is a vector IN operator */ pLeft = pExpr->pLeft; nVal = sqlite3ExprVectorSize(pLeft); /* Construct the ephemeral table that will contain the content of ** RHS of the IN operator. */ pExpr->iTable = iTab; addr = sqlite3VdbeAddOp2(v, OP_OpenEphemeral, pExpr->iTable, nVal); #ifdef SQLITE_ENABLE_EXPLAIN_COMMENTS if( ExprHasProperty(pExpr, EP_xIsSelect) ){ VdbeComment((v, "Result of SELECT %u", pExpr->x.pSelect->selId)); }else{ VdbeComment((v, "RHS of IN operator")); } #endif pKeyInfo = sqlite3KeyInfoAlloc(pParse->db, nVal, 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. */ Select *pSelect = pExpr->x.pSelect; ExprList *pEList = pSelect->pEList; ExplainQueryPlan((pParse, 1, "%sLIST SUBQUERY %d", addrOnce?"":"CORRELATED ", pSelect->selId )); /* If the LHS and RHS of the IN operator do not match, that ** error will have been caught long before we reach this point. */ if( ALWAYS(pEList->nExpr==nVal) ){ SelectDest dest; int i; sqlite3SelectDestInit(&dest, SRT_Set, iTab); dest.zAffSdst = exprINAffinity(pParse, pExpr); pSelect->iLimit = 0; testcase( pSelect->selFlags & SF_Distinct ); testcase( pKeyInfo==0 ); /* Caused by OOM in sqlite3KeyInfoAlloc() */ if( sqlite3Select(pParse, pSelect, &dest) ){ sqlite3DbFree(pParse->db, dest.zAffSdst); sqlite3KeyInfoUnref(pKeyInfo); return; } sqlite3DbFree(pParse->db, dest.zAffSdst); assert( pKeyInfo!=0 ); /* OOM will cause exit after sqlite3Select() */ assert( pEList!=0 ); assert( pEList->nExpr>0 ); assert( sqlite3KeyInfoIsWriteable(pKeyInfo) ); for(i=0; iaColl[i] = sqlite3BinaryCompareCollSeq( pParse, p, pEList->a[i].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 is a column, then use ** that columns affinity when building index keys. If is not ** a column, use numeric affinity. */ char affinity; /* Affinity of the LHS of the IN */ int i; ExprList *pList = pExpr->x.pList; struct ExprList_item *pItem; int r1, r2, r3; affinity = sqlite3ExprAffinity(pLeft); if( !affinity ){ affinity = SQLITE_AFF_BLOB; } if( pKeyInfo ){ assert( sqlite3KeyInfoIsWriteable(pKeyInfo) ); pKeyInfo->aColl[0] = sqlite3ExprCollSeq(pParse, pExpr->pLeft); } /* Loop through each expression in . */ r1 = sqlite3GetTempReg(pParse); r2 = sqlite3GetTempReg(pParse); for(i=pList->nExpr, pItem=pList->a; i>0; i--, pItem++){ Expr *pE2 = pItem->pExpr; /* If the expression is not constant then we will need to ** disable the test that was generated above that makes sure ** this code only executes once. Because for a non-constant ** expression we need to rerun this code each time. */ if( addrOnce && !sqlite3ExprIsConstant(pE2) ){ sqlite3VdbeChangeToNoop(v, addrOnce); ExprClearProperty(pExpr, EP_Subrtn); addrOnce = 0; } /* Evaluate the expression and insert it into the temp table */ r3 = sqlite3ExprCodeTarget(pParse, pE2, r1); sqlite3VdbeAddOp4(v, OP_MakeRecord, r3, 1, r2, &affinity, 1); sqlite3VdbeAddOp4Int(v, OP_IdxInsert, iTab, r2, r3, 1); } sqlite3ReleaseTempReg(pParse, r1); sqlite3ReleaseTempReg(pParse, r2); } if( pKeyInfo ){ sqlite3VdbeChangeP4(v, addr, (void *)pKeyInfo, P4_KEYINFO); } if( addrOnce ){ sqlite3VdbeJumpHere(v, addrOnce); /* Subroutine return */ sqlite3VdbeAddOp1(v, OP_Return, pExpr->y.sub.regReturn); sqlite3VdbeChangeP1(v, pExpr->y.sub.iAddr-1, sqlite3VdbeCurrentAddr(v)-1); } } #endif /* SQLITE_OMIT_SUBQUERY */ /* ** Generate code for scalar subqueries used as a subquery expression ** or EXISTS operator: ** ** (SELECT a FROM b) -- subquery ** EXISTS (SELECT a FROM b) -- EXISTS subquery ** ** The pExpr parameter is the SELECT or EXISTS operator to be coded. ** ** The register that holds the result. For a multi-column SELECT, ** the result is stored in a contiguous array of registers and the ** return value is the register of the left-most result column. ** Return 0 if an error occurs. */ #ifndef SQLITE_OMIT_SUBQUERY int sqlite3CodeSubselect(Parse *pParse, Expr *pExpr){ int addrOnce = 0; /* Address of OP_Once at top of subroutine */ int rReg = 0; /* Register storing resulting */ Select *pSel; /* SELECT statement to encode */ SelectDest dest; /* How to deal with SELECT result */ int nReg; /* Registers to allocate */ Expr *pLimit; /* New limit expression */ Vdbe *v = pParse->pVdbe; assert( v!=0 ); 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; /* The evaluation of the EXISTS/SELECT must be repeated 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) ){ /* If this routine has already been coded, then invoke it as a ** subroutine. */ if( ExprHasProperty(pExpr, EP_Subrtn) ){ ExplainQueryPlan((pParse, 0, "REUSE SUBQUERY %d", pSel->selId)); sqlite3VdbeAddOp2(v, OP_Gosub, pExpr->y.sub.regReturn, pExpr->y.sub.iAddr); return pExpr->iTable; } /* Begin coding the subroutine */ ExprSetProperty(pExpr, EP_Subrtn); pExpr->y.sub.regReturn = ++pParse->nMem; pExpr->y.sub.iAddr = sqlite3VdbeAddOp2(v, OP_Integer, 0, pExpr->y.sub.regReturn) + 1; VdbeComment((v, "return address")); addrOnce = sqlite3VdbeAddOp0(v, OP_Once); VdbeCoverage(v); } /* For a SELECT, generate code to put the values for all columns of ** the first row into an array of registers and return the index of ** the first register. ** ** If this is an EXISTS, write an integer 0 (not exists) or 1 (exists) ** into a register and return that register number. ** ** In both cases, the query is augmented with "LIMIT 1". Any ** preexisting limit is discarded in place of the new LIMIT 1. */ ExplainQueryPlan((pParse, 1, "%sSCALAR SUBQUERY %d", addrOnce?"":"CORRELATED ", pSel->selId)); nReg = pExpr->op==TK_SELECT ? pSel->pEList->nExpr : 1; sqlite3SelectDestInit(&dest, 0, pParse->nMem+1); pParse->nMem += nReg; if( pExpr->op==TK_SELECT ){ dest.eDest = SRT_Mem; dest.iSdst = dest.iSDParm; dest.nSdst = nReg; sqlite3VdbeAddOp3(v, OP_Null, 0, dest.iSDParm, dest.iSDParm+nReg-1); VdbeComment((v, "Init subquery result")); }else{ dest.eDest = SRT_Exists; sqlite3VdbeAddOp2(v, OP_Integer, 0, dest.iSDParm); VdbeComment((v, "Init EXISTS result")); } pLimit = sqlite3ExprAlloc(pParse->db, TK_INTEGER,&sqlite3IntTokens[1], 0); if( pSel->pLimit ){ sqlite3ExprDelete(pParse->db, pSel->pLimit->pLeft); pSel->pLimit->pLeft = pLimit; }else{ pSel->pLimit = sqlite3PExpr(pParse, TK_LIMIT, pLimit, 0); } pSel->iLimit = 0; if( sqlite3Select(pParse, pSel, &dest) ){ return 0; } pExpr->iTable = rReg = dest.iSDParm; ExprSetVVAProperty(pExpr, EP_NoReduce); if( addrOnce ){ sqlite3VdbeJumpHere(v, addrOnce); /* Subroutine return */ sqlite3VdbeAddOp1(v, OP_Return, pExpr->y.sub.regReturn); sqlite3VdbeChangeP1(v, pExpr->y.sub.iAddr-1, sqlite3VdbeCurrentAddr(v)-1); } return rReg; } #endif /* SQLITE_OMIT_SUBQUERY */ #ifndef SQLITE_OMIT_SUBQUERY /* ** Expr pIn is an IN(...) expression. This function checks that the ** sub-select on the RHS of the IN() operator has the same number of ** columns as the vector on the LHS. Or, if the RHS of the IN() is not ** a sub-query, that the LHS is a vector of size 1. */ int sqlite3ExprCheckIN(Parse *pParse, Expr *pIn){ int nVector = sqlite3ExprVectorSize(pIn->pLeft); if( (pIn->flags & EP_xIsSelect) ){ if( nVector!=pIn->x.pSelect->pEList->nExpr ){ sqlite3SubselectError(pParse, pIn->x.pSelect->pEList->nExpr, nVector); return 1; } }else if( nVector!=1 ){ sqlite3VectorErrorMsg(pParse, pIn->pLeft); return 1; } return 0; } #endif #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 or vector expression. The ** right-hand side (RHS) is an array of zero or more scalar values, or a ** subquery. If the RHS is a subquery, the number of result columns must ** match the number of columns in the vector on the LHS. If the RHS is ** a list of values, the LHS must be a scalar. ** ** The IN operator is true if the LHS value is contained within the RHS. ** The result is false if the LHS is definitely not in the RHS. The ** result is NULL if the presence of the LHS in the RHS cannot be ** determined due to NULLs. ** ** This routine generates code that jumps 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. ** ** See the separate in-operator.md documentation file in the canonical ** SQLite source tree for additional information. */ 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 */ int eType; /* Type of the RHS */ int rLhs; /* Register(s) holding the LHS values */ int rLhsOrig; /* LHS values prior to reordering by aiMap[] */ Vdbe *v; /* Statement under construction */ int *aiMap = 0; /* Map from vector field to index column */ char *zAff = 0; /* Affinity string for comparisons */ int nVector; /* Size of vectors for this IN operator */ int iDummy; /* Dummy parameter to exprCodeVector() */ Expr *pLeft; /* The LHS of the IN operator */ int i; /* loop counter */ int destStep2; /* Where to jump when NULLs seen in step 2 */ int destStep6 = 0; /* Start of code for Step 6 */ int addrTruthOp; /* Address of opcode that determines the IN is true */ int destNotNull; /* Jump here if a comparison is not true in step 6 */ int addrTop; /* Top of the step-6 loop */ int iTab = 0; /* Index to use */ pLeft = pExpr->pLeft; if( sqlite3ExprCheckIN(pParse, pExpr) ) return; zAff = exprINAffinity(pParse, pExpr); nVector = sqlite3ExprVectorSize(pExpr->pLeft); aiMap = (int*)sqlite3DbMallocZero( pParse->db, nVector*(sizeof(int) + sizeof(char)) + 1 ); if( pParse->db->mallocFailed ) goto sqlite3ExprCodeIN_oom_error; /* Attempt to compute the RHS. After this step, if anything other than ** IN_INDEX_NOOP is returned, the table opened with cursor iTab ** contains the values that make up the RHS. If IN_INDEX_NOOP is returned, ** the RHS has not yet been coded. */ v = pParse->pVdbe; assert( v!=0 ); /* OOM detected prior to this routine */ VdbeNoopComment((v, "begin IN expr")); eType = sqlite3FindInIndex(pParse, pExpr, IN_INDEX_MEMBERSHIP | IN_INDEX_NOOP_OK, destIfFalse==destIfNull ? 0 : &rRhsHasNull, aiMap, &iTab); assert( pParse->nErr || nVector==1 || eType==IN_INDEX_EPH || eType==IN_INDEX_INDEX_ASC || eType==IN_INDEX_INDEX_DESC ); #ifdef SQLITE_DEBUG /* Confirm that aiMap[] contains nVector integer values between 0 and ** nVector-1. */ for(i=0; i from " IN (...)". If the LHS is a ** vector, then it is stored in an array of nVector registers starting ** at r1. ** ** sqlite3FindInIndex() might have reordered the fields of the LHS vector ** so that the fields are in the same order as an existing index. The ** aiMap[] array contains a mapping from the original LHS field order to ** the field order that matches the RHS index. */ rLhsOrig = exprCodeVector(pParse, pLeft, &iDummy); for(i=0; ix.pList; CollSeq *pColl = sqlite3ExprCollSeq(pParse, pExpr->pLeft); int labelOk = sqlite3VdbeMakeLabel(pParse); int r2, regToFree; int regCkNull = 0; int ii; assert( !ExprHasProperty(pExpr, EP_xIsSelect) ); if( destIfNull!=destIfFalse ){ regCkNull = sqlite3GetTempReg(pParse); sqlite3VdbeAddOp3(v, OP_BitAnd, rLhs, rLhs, regCkNull); } for(ii=0; iinExpr; ii++){ r2 = sqlite3ExprCodeTemp(pParse, pList->a[ii].pExpr, ®ToFree); if( regCkNull && sqlite3ExprCanBeNull(pList->a[ii].pExpr) ){ sqlite3VdbeAddOp3(v, OP_BitAnd, regCkNull, r2, regCkNull); } if( iinExpr-1 || destIfNull!=destIfFalse ){ sqlite3VdbeAddOp4(v, OP_Eq, rLhs, labelOk, r2, (void*)pColl, P4_COLLSEQ); VdbeCoverageIf(v, iinExpr-1); VdbeCoverageIf(v, ii==pList->nExpr-1); sqlite3VdbeChangeP5(v, zAff[0]); }else{ assert( destIfNull==destIfFalse ); sqlite3VdbeAddOp4(v, OP_Ne, rLhs, destIfFalse, r2, (void*)pColl, P4_COLLSEQ); VdbeCoverage(v); sqlite3VdbeChangeP5(v, zAff[0] | SQLITE_JUMPIFNULL); } sqlite3ReleaseTempReg(pParse, regToFree); } if( regCkNull ){ sqlite3VdbeAddOp2(v, OP_IsNull, regCkNull, destIfNull); VdbeCoverage(v); sqlite3VdbeGoto(v, destIfFalse); } sqlite3VdbeResolveLabel(v, labelOk); sqlite3ReleaseTempReg(pParse, regCkNull); goto sqlite3ExprCodeIN_finished; } /* Step 2: Check to see if the LHS contains any NULL columns. If the ** LHS does contain NULLs then the result must be either FALSE or NULL. ** We will then skip the binary search of the RHS. */ if( destIfNull==destIfFalse ){ destStep2 = destIfFalse; }else{ destStep2 = destStep6 = sqlite3VdbeMakeLabel(pParse); } for(i=0; ipLeft, i); if( sqlite3ExprCanBeNull(p) ){ sqlite3VdbeAddOp2(v, OP_IsNull, rLhs+i, destStep2); VdbeCoverage(v); } } /* Step 3. The LHS is now known to be non-NULL. Do the binary search ** of the RHS using the LHS as a probe. If found, the result is ** true. */ if( eType==IN_INDEX_ROWID ){ /* In this case, the RHS is the ROWID of table b-tree and so we also ** know that the RHS is non-NULL. Hence, we combine steps 3 and 4 ** into a single opcode. */ sqlite3VdbeAddOp3(v, OP_SeekRowid, iTab, destIfFalse, rLhs); VdbeCoverage(v); addrTruthOp = sqlite3VdbeAddOp0(v, OP_Goto); /* Return True */ }else{ sqlite3VdbeAddOp4(v, OP_Affinity, rLhs, nVector, 0, zAff, nVector); if( destIfFalse==destIfNull ){ /* Combine Step 3 and Step 5 into a single opcode */ sqlite3VdbeAddOp4Int(v, OP_NotFound, iTab, destIfFalse, rLhs, nVector); VdbeCoverage(v); goto sqlite3ExprCodeIN_finished; } /* Ordinary Step 3, for the case where FALSE and NULL are distinct */ addrTruthOp = sqlite3VdbeAddOp4Int(v, OP_Found, iTab, 0, rLhs, nVector); VdbeCoverage(v); } /* Step 4. If the RHS is known to be non-NULL and we did not find ** an match on the search above, then the result must be FALSE. */ if( rRhsHasNull && nVector==1 ){ sqlite3VdbeAddOp2(v, OP_NotNull, rRhsHasNull, destIfFalse); VdbeCoverage(v); } /* Step 5. If we do not care about the difference between NULL and ** FALSE, then just return false. */ if( destIfFalse==destIfNull ) sqlite3VdbeGoto(v, destIfFalse); /* Step 6: Loop through rows of the RHS. Compare each row to the LHS. ** If any comparison is NULL, then the result is NULL. If all ** comparisons are FALSE then the final result is FALSE. ** ** For a scalar LHS, it is sufficient to check just the first row ** of the RHS. */ if( destStep6 ) sqlite3VdbeResolveLabel(v, destStep6); addrTop = sqlite3VdbeAddOp2(v, OP_Rewind, iTab, destIfFalse); VdbeCoverage(v); if( nVector>1 ){ destNotNull = sqlite3VdbeMakeLabel(pParse); }else{ /* For nVector==1, combine steps 6 and 7 by immediately returning ** FALSE if the first comparison is not NULL */ destNotNull = destIfFalse; } for(i=0; i1 ){ sqlite3VdbeResolveLabel(v, destNotNull); sqlite3VdbeAddOp2(v, OP_Next, iTab, addrTop+1); VdbeCoverage(v); /* Step 7: If we reach this point, we know that the result must ** be false. */ sqlite3VdbeAddOp2(v, OP_Goto, 0, destIfFalse); } /* Jumps here in order to return true. */ sqlite3VdbeJumpHere(v, addrTruthOp); sqlite3ExprCodeIN_finished: if( rLhs!=rLhsOrig ) sqlite3ReleaseTempReg(pParse, rLhs); VdbeComment((v, "end IN expr")); sqlite3ExprCodeIN_oom_error: sqlite3DbFree(pParse->db, aiMap); sqlite3DbFree(pParse->db, zAff); } #endif /* SQLITE_OMIT_SUBQUERY */ #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; sqlite3AtoF(z, &value, sqlite3Strlen30(z), SQLITE_UTF8); assert( !sqlite3IsNaN(value) ); /* The new AtoF never returns NaN */ if( negateFlag ) value = -value; sqlite3VdbeAddOp4Dup8(v, OP_Real, 0, iMem, 0, (u8*)&value, 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 = sqlite3DecOrHexToI64(z, &value); if( (c==3 && !negFlag) || (c==2) || (negFlag && value==SMALLEST_INT64)){ #ifdef SQLITE_OMIT_FLOATING_POINT sqlite3ErrorMsg(pParse, "oversized integer: %s%s", negFlag ? "-" : "", z); #else #ifndef SQLITE_OMIT_HEX_INTEGER if( sqlite3_strnicmp(z,"0x",2)==0 ){ sqlite3ErrorMsg(pParse, "hex literal too big: %s%s", negFlag?"-":"",z); }else #endif { codeReal(v, z, negFlag, iMem); } #endif }else{ if( negFlag ){ value = c==3 ? SMALLEST_INT64 : -value; } sqlite3VdbeAddOp4Dup8(v, OP_Int64, 0, iMem, 0, (u8*)&value, P4_INT64); } } } /* Generate code that will load into register regOut a value that is ** appropriate for the iIdxCol-th column of index pIdx. */ void sqlite3ExprCodeLoadIndexColumn( Parse *pParse, /* The parsing context */ Index *pIdx, /* The index whose column is to be loaded */ int iTabCur, /* Cursor pointing to a table row */ int iIdxCol, /* The column of the index to be loaded */ int regOut /* Store the index column value in this register */ ){ i16 iTabCol = pIdx->aiColumn[iIdxCol]; if( iTabCol==XN_EXPR ){ assert( pIdx->aColExpr ); assert( pIdx->aColExpr->nExpr>iIdxCol ); pParse->iSelfTab = iTabCur + 1; sqlite3ExprCodeCopy(pParse, pIdx->aColExpr->a[iIdxCol].pExpr, regOut); pParse->iSelfTab = 0; }else{ sqlite3ExprCodeGetColumnOfTable(pParse->pVdbe, pIdx->pTable, iTabCur, iTabCol, regOut); } } /* ** 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 table cursor. Or the PK cursor for WITHOUT ROWID */ int iCol, /* Index of the column to extract */ int regOut /* Extract the value into this register */ ){ if( pTab==0 ){ sqlite3VdbeAddOp3(v, OP_Column, iTabCur, iCol, regOut); return; } if( iCol<0 || iCol==pTab->iPKey ){ sqlite3VdbeAddOp2(v, OP_Rowid, iTabCur, regOut); }else{ int op = IsVirtual(pTab) ? OP_VColumn : OP_Column; int x = iCol; if( !HasRowid(pTab) && !IsVirtual(pTab) ){ x = sqlite3ColumnOfIndex(sqlite3PrimaryKeyIndex(pTab), iCol); } sqlite3VdbeAddOp3(v, op, iTabCur, x, 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 register iReg. ** ** 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 + FLAGS */ ){ Vdbe *v = pParse->pVdbe; assert( v!=0 ); sqlite3ExprCodeGetColumnOfTable(v, pTab, iTable, iColumn, iReg); if( p5 ){ sqlite3VdbeChangeP5(v, p5); } return iReg; } /* ** Generate code to move content from registers iFrom...iFrom+nReg-1 ** over to iTo..iTo+nReg-1. */ void sqlite3ExprCodeMove(Parse *pParse, int iFrom, int iTo, int nReg){ assert( iFrom>=iTo+nReg || iFrom+nReg<=iTo ); sqlite3VdbeAddOp3(pParse->pVdbe, OP_Move, iFrom, iTo, nReg); } /* ** Convert a scalar expression node to a TK_REGISTER referencing ** register iReg. The caller must ensure that iReg already contains ** the correct value for the expression. */ static void exprToRegister(Expr *pExpr, int iReg){ Expr *p = sqlite3ExprSkipCollate(pExpr); p->op2 = p->op; p->op = TK_REGISTER; p->iTable = iReg; ExprClearProperty(p, EP_Skip); } /* ** Evaluate an expression (either a vector or a scalar expression) and store ** the result in continguous temporary registers. Return the index of ** the first register used to store the result. ** ** If the returned result register is a temporary scalar, then also write ** that register number into *piFreeable. If the returned result register ** is not a temporary or if the expression is a vector set *piFreeable ** to 0. */ static int exprCodeVector(Parse *pParse, Expr *p, int *piFreeable){ int iResult; int nResult = sqlite3ExprVectorSize(p); if( nResult==1 ){ iResult = sqlite3ExprCodeTemp(pParse, p, piFreeable); }else{ *piFreeable = 0; if( p->op==TK_SELECT ){ #if SQLITE_OMIT_SUBQUERY iResult = 0; #else iResult = sqlite3CodeSubselect(pParse, p); #endif }else{ int i; iResult = pParse->nMem+1; pParse->nMem += nResult; for(i=0; ix.pList->a[i].pExpr, i+iResult); } } } return iResult; } /* ** 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; /* Various register numbers */ Expr tempX; /* Temporary expression node */ int p5 = 0; assert( target>0 && target<=pParse->nMem ); if( v==0 ){ assert( pParse->db->mallocFailed ); return 0; } expr_code_doover: 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 ); return pCol->iMem; }else if( pAggInfo->useSortingIdx ){ sqlite3VdbeAddOp3(v, OP_Column, pAggInfo->sortingIdxPTab, pCol->iSorterColumn, target); return target; } /* Otherwise, fall thru into the TK_COLUMN case */ } case TK_COLUMN: { int iTab = pExpr->iTable; if( ExprHasProperty(pExpr, EP_FixedCol) ){ /* This COLUMN expression is really a constant due to WHERE clause ** constraints, and that constant is coded by the pExpr->pLeft ** expresssion. However, make sure the constant has the correct ** datatype by applying the Affinity of the table column to the ** constant. */ int iReg = sqlite3ExprCodeTarget(pParse, pExpr->pLeft,target); int aff = sqlite3TableColumnAffinity(pExpr->y.pTab, pExpr->iColumn); if( aff!=SQLITE_AFF_BLOB ){ static const char zAff[] = "B\000C\000D\000E"; assert( SQLITE_AFF_BLOB=='A' ); assert( SQLITE_AFF_TEXT=='B' ); if( iReg!=target ){ sqlite3VdbeAddOp2(v, OP_SCopy, iReg, target); iReg = target; } sqlite3VdbeAddOp4(v, OP_Affinity, iReg, 1, 0, &zAff[(aff-'B')*2], P4_STATIC); } return iReg; } if( iTab<0 ){ if( pParse->iSelfTab<0 ){ /* Generating CHECK constraints or inserting into partial index */ return pExpr->iColumn - pParse->iSelfTab; }else{ /* Coding an expression that is part of an index where column names ** in the index refer to the table to which the index belongs */ iTab = pParse->iSelfTab - 1; } } return sqlite3ExprCodeGetColumn(pParse, pExpr->y.pTab, pExpr->iColumn, iTab, target, pExpr->op2); } case TK_INTEGER: { codeInteger(pParse, pExpr, 0, target); return target; } case TK_TRUEFALSE: { sqlite3VdbeAddOp2(v, OP_Integer, sqlite3ExprTruthValue(pExpr), target); return target; } #ifndef SQLITE_OMIT_FLOATING_POINT case TK_FLOAT: { assert( !ExprHasProperty(pExpr, EP_IntValue) ); codeReal(v, pExpr->u.zToken, 0, target); return target; } #endif case TK_STRING: { assert( !ExprHasProperty(pExpr, EP_IntValue) ); sqlite3VdbeLoadString(v, target, pExpr->u.zToken); return target; } case TK_NULL: { sqlite3VdbeAddOp2(v, OP_Null, 0, target); return target; } #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); return target; } #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 ){ const char *z = sqlite3VListNumToName(pParse->pVList, pExpr->iColumn); assert( pExpr->u.zToken[0]=='?' || strcmp(pExpr->u.zToken, z)==0 ); pParse->pVList[0] = 0; /* Indicate VList may no longer be enlarged */ sqlite3VdbeAppendP4(v, (char*)z, P4_STATIC); } return target; } case TK_REGISTER: { return pExpr->iTable; } #ifndef SQLITE_OMIT_CAST case TK_CAST: { /* Expressions of the form: CAST(pLeft AS token) */ inReg = sqlite3ExprCodeTarget(pParse, pExpr->pLeft, target); if( inReg!=target ){ sqlite3VdbeAddOp2(v, OP_SCopy, inReg, target); inReg = target; } sqlite3VdbeAddOp2(v, OP_Cast, target, sqlite3AffinityType(pExpr->u.zToken, 0)); return inReg; } #endif /* SQLITE_OMIT_CAST */ case TK_IS: case TK_ISNOT: op = (op==TK_IS) ? TK_EQ : TK_NE; p5 = SQLITE_NULLEQ; /* fall-through */ case TK_LT: case TK_LE: case TK_GT: case TK_GE: case TK_NE: case TK_EQ: { Expr *pLeft = pExpr->pLeft; if( sqlite3ExprIsVector(pLeft) ){ codeVectorCompare(pParse, pExpr, target, op, p5); }else{ r1 = sqlite3ExprCodeTemp(pParse, pLeft, ®Free1); r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, ®Free2); codeCompare(pParse, pLeft, pExpr->pRight, op, r1, r2, inReg, SQLITE_STOREP2 | p5); assert(TK_LT==OP_Lt); testcase(op==OP_Lt); VdbeCoverageIf(v,op==OP_Lt); assert(TK_LE==OP_Le); testcase(op==OP_Le); VdbeCoverageIf(v,op==OP_Le); assert(TK_GT==OP_Gt); testcase(op==OP_Gt); VdbeCoverageIf(v,op==OP_Gt); assert(TK_GE==OP_Ge); testcase(op==OP_Ge); VdbeCoverageIf(v,op==OP_Ge); assert(TK_EQ==OP_Eq); testcase(op==OP_Eq); VdbeCoverageIf(v,op==OP_Eq); assert(TK_NE==OP_Ne); testcase(op==OP_Ne); VdbeCoverageIf(v,op==OP_Ne); 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 ); testcase( op==TK_AND ); assert( TK_OR==OP_Or ); testcase( op==TK_OR ); assert( TK_PLUS==OP_Add ); testcase( op==TK_PLUS ); assert( TK_MINUS==OP_Subtract ); testcase( op==TK_MINUS ); assert( TK_REM==OP_Remainder ); testcase( op==TK_REM ); assert( TK_BITAND==OP_BitAnd ); testcase( op==TK_BITAND ); assert( TK_BITOR==OP_BitOr ); testcase( op==TK_BITOR ); assert( TK_SLASH==OP_Divide ); testcase( op==TK_SLASH ); assert( TK_LSHIFT==OP_ShiftLeft ); testcase( op==TK_LSHIFT ); assert( TK_RSHIFT==OP_ShiftRight ); testcase( op==TK_RSHIFT ); assert( TK_CONCAT==OP_Concat ); 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); return target; #ifndef SQLITE_OMIT_FLOATING_POINT }else if( pLeft->op==TK_FLOAT ){ assert( !ExprHasProperty(pExpr, EP_IntValue) ); codeReal(v, pLeft->u.zToken, 1, target); return target; #endif }else{ tempX.op = TK_INTEGER; tempX.flags = EP_IntValue|EP_TokenOnly; tempX.u.iValue = 0; r1 = sqlite3ExprCodeTemp(pParse, &tempX, ®Free1); r2 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free2); sqlite3VdbeAddOp3(v, OP_Subtract, r2, r1, target); testcase( regFree2==0 ); } break; } case TK_BITNOT: case TK_NOT: { assert( TK_BITNOT==OP_BitNot ); testcase( op==TK_BITNOT ); assert( TK_NOT==OP_Not ); testcase( op==TK_NOT ); r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free1); testcase( regFree1==0 ); sqlite3VdbeAddOp2(v, op, r1, inReg); break; } case TK_TRUTH: { int isTrue; /* IS TRUE or IS NOT TRUE */ int bNormal; /* IS TRUE or IS FALSE */ r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free1); testcase( regFree1==0 ); isTrue = sqlite3ExprTruthValue(pExpr->pRight); bNormal = pExpr->op2==TK_IS; testcase( isTrue && bNormal); testcase( !isTrue && bNormal); sqlite3VdbeAddOp4Int(v, OP_IsTrue, r1, inReg, !isTrue, isTrue ^ bNormal); break; } case TK_ISNULL: case TK_NOTNULL: { int addr; assert( TK_ISNULL==OP_IsNull ); testcase( op==TK_ISNULL ); assert( TK_NOTNULL==OP_NotNull ); testcase( op==TK_NOTNULL ); sqlite3VdbeAddOp2(v, OP_Integer, 1, target); r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free1); testcase( regFree1==0 ); addr = sqlite3VdbeAddOp1(v, op, r1); VdbeCoverageIf(v, op==TK_ISNULL); VdbeCoverageIf(v, op==TK_NOTNULL); sqlite3VdbeAddOp2(v, OP_Integer, 0, target); 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{ return pInfo->aFunc[pExpr->iAgg].iMem; } break; } case TK_FUNCTION: { ExprList *pFarg; /* List of function arguments */ int nFarg; /* Number of function arguments */ FuncDef *pDef; /* The function definition object */ const char *zId; /* The function name */ u32 constMask = 0; /* Mask of function arguments that are constant */ int i; /* Loop counter */ sqlite3 *db = pParse->db; /* The database connection */ u8 enc = ENC(db); /* The text encoding used by this database */ CollSeq *pColl = 0; /* A collating sequence */ #ifndef SQLITE_OMIT_WINDOWFUNC if( ExprHasProperty(pExpr, EP_WinFunc) ){ return pExpr->y.pWin->regResult; } #endif if( ConstFactorOk(pParse) && sqlite3ExprIsConstantNotJoin(pExpr) ){ /* SQL functions can be expensive. So try to move constant functions ** out of the inner loop, even if that means an extra OP_Copy. */ return sqlite3ExprCodeAtInit(pParse, pExpr, -1); } assert( !ExprHasProperty(pExpr, EP_xIsSelect) ); 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; pDef = sqlite3FindFunction(db, zId, nFarg, enc, 0); #ifdef SQLITE_ENABLE_UNKNOWN_SQL_FUNCTION if( pDef==0 && pParse->explain ){ pDef = sqlite3FindFunction(db, "unknown", nFarg, enc, 0); } #endif if( pDef==0 || pDef->xFinalize!=0 ){ sqlite3ErrorMsg(pParse, "unknown function: %s()", zId); break; } /* Attempt a direct implementation of the built-in COALESCE() and ** IFNULL() functions. This avoids unnecessary evaluation of ** arguments past the first non-NULL argument. */ if( pDef->funcFlags & SQLITE_FUNC_COALESCE ){ int endCoalesce = sqlite3VdbeMakeLabel(pParse); assert( nFarg>=2 ); sqlite3ExprCode(pParse, pFarg->a[0].pExpr, target); for(i=1; ia[i].pExpr, target); } 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 ); return sqlite3ExprCodeTarget(pParse, pFarg->a[0].pExpr, target); } #ifdef SQLITE_DEBUG /* The AFFINITY() function evaluates to a string that describes ** the type affinity of the argument. This is used for testing of ** the SQLite type logic. */ if( pDef->funcFlags & SQLITE_FUNC_AFFINITY ){ const char *azAff[] = { "blob", "text", "numeric", "integer", "real" }; char aff; assert( nFarg==1 ); aff = sqlite3ExprAffinity(pFarg->a[0].pExpr); sqlite3VdbeLoadString(v, target, aff ? azAff[aff-SQLITE_AFF_BLOB] : "none"); return target; } #endif for(i=0; ia[i].pExpr) ){ testcase( i==31 ); constMask |= MASKBIT32(i); } if( (pDef->funcFlags & SQLITE_FUNC_NEEDCOLL)!=0 && !pColl ){ pColl = sqlite3ExprCollSeq(pParse, pFarg->a[i].pExpr); } } if( pFarg ){ if( constMask ){ r1 = pParse->nMem+1; pParse->nMem += nFarg; }else{ 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 & OPFLAG_LENGTHARG ); pFarg->a[0].pExpr->op2 = pDef->funcFlags & (OPFLAG_LENGTHARG|OPFLAG_TYPEOFARG); } } sqlite3ExprCodeExprList(pParse, pFarg, r1, 0, SQLITE_ECEL_DUP|SQLITE_ECEL_FACTOR); }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 && ExprHasProperty(pExpr, 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 if( pDef->funcFlags & SQLITE_FUNC_NEEDCOLL ){ if( !pColl ) pColl = db->pDfltColl; sqlite3VdbeAddOp4(v, OP_CollSeq, 0, 0, 0, (char *)pColl, P4_COLLSEQ); } #ifdef SQLITE_ENABLE_OFFSET_SQL_FUNC if( pDef->funcFlags & SQLITE_FUNC_OFFSET ){ Expr *pArg = pFarg->a[0].pExpr; if( pArg->op==TK_COLUMN ){ sqlite3VdbeAddOp3(v, OP_Offset, pArg->iTable, pArg->iColumn, target); }else{ sqlite3VdbeAddOp2(v, OP_Null, 0, target); } }else #endif { sqlite3VdbeAddOp4(v, pParse->iSelfTab ? OP_PureFunc0 : OP_Function0, constMask, r1, target, (char*)pDef, P4_FUNCDEF); sqlite3VdbeChangeP5(v, (u8)nFarg); } if( nFarg && constMask==0 ){ sqlite3ReleaseTempRange(pParse, r1, nFarg); } return target; } #ifndef SQLITE_OMIT_SUBQUERY case TK_EXISTS: case TK_SELECT: { int nCol; testcase( op==TK_EXISTS ); testcase( op==TK_SELECT ); if( op==TK_SELECT && (nCol = pExpr->x.pSelect->pEList->nExpr)!=1 ){ sqlite3SubselectError(pParse, nCol, 1); }else{ return sqlite3CodeSubselect(pParse, pExpr); } break; } case TK_SELECT_COLUMN: { int n; if( pExpr->pLeft->iTable==0 ){ pExpr->pLeft->iTable = sqlite3CodeSubselect(pParse, pExpr->pLeft); } assert( pExpr->iTable==0 || pExpr->pLeft->op==TK_SELECT ); if( pExpr->iTable && pExpr->iTable!=(n = sqlite3ExprVectorSize(pExpr->pLeft)) ){ sqlite3ErrorMsg(pParse, "%d columns assigned %d values", pExpr->iTable, n); } return pExpr->pLeft->iTable + pExpr->iColumn; } case TK_IN: { int destIfFalse = sqlite3VdbeMakeLabel(pParse); int destIfNull = sqlite3VdbeMakeLabel(pParse); 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); return target; } #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: { exprCodeBetween(pParse, pExpr, target, 0, 0); return target; } case TK_SPAN: case TK_COLLATE: case TK_UPLUS: { pExpr = pExpr->pLeft; goto expr_code_doover; /* 2018-04-28: Prevent deep recursion. OSSFuzz. */ } 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->y.pTab; int p1 = pExpr->iTable * (pTab->nCol+1) + 1 + pExpr->iColumn; assert( pExpr->iTable==0 || pExpr->iTable==1 ); assert( pExpr->iColumn>=-1 && pExpr->iColumnnCol ); assert( pTab->iPKey<0 || pExpr->iColumn!=pTab->iPKey ); assert( p1>=0 && p1<(pTab->nCol*2+2) ); sqlite3VdbeAddOp2(v, OP_Param, p1, target); VdbeComment((v, "r[%d]=%s.%s", target, (pExpr->iTable ? "new" : "old"), (pExpr->iColumn<0 ? "rowid" : pExpr->y.pTab->aCol[pExpr->iColumn].zName) )); #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. ** ** EVIDENCE-OF: R-60985-57662 SQLite will convert the value back to ** floating point when extracting it from the record. */ if( pExpr->iColumn>=0 && pTab->aCol[pExpr->iColumn].affinity==SQLITE_AFF_REAL ){ sqlite3VdbeAddOp1(v, OP_RealAffinity, target); } #endif break; } case TK_VECTOR: { sqlite3ErrorMsg(pParse, "row value misused"); break; } case TK_IF_NULL_ROW: { int addrINR; addrINR = sqlite3VdbeAddOp1(v, OP_IfNullRow, pExpr->iTable); inReg = sqlite3ExprCodeTarget(pParse, pExpr->pLeft, target); sqlite3VdbeJumpHere(v, addrINR); sqlite3VdbeChangeP3(v, addrINR, inReg); 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 *pX; /* The X expression */ Expr *pTest = 0; /* X==Ei (form A) or just Ei (form B) */ 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(pParse); if( (pX = pExpr->pLeft)!=0 ){ exprNodeCopy(&tempX, pX); testcase( pX->op==TK_COLUMN ); exprToRegister(&tempX, exprCodeVector(pParse, &tempX, ®Free1)); testcase( regFree1==0 ); memset(&opCompare, 0, sizeof(opCompare)); opCompare.op = TK_EQ; opCompare.pLeft = &tempX; 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; iop==TK_COLUMN ); sqlite3ExprIfFalse(pParse, pTest, nextCase, SQLITE_JUMPIFNULL); testcase( aListelem[i+1].pExpr->op==TK_COLUMN ); sqlite3ExprCode(pParse, aListelem[i+1].pExpr, target); sqlite3VdbeGoto(v, endLabel); sqlite3VdbeResolveLabel(v, nextCase); } if( (nExpr&1)!=0 ){ sqlite3ExprCode(pParse, pEList->a[nExpr-1].pExpr, target); }else{ sqlite3VdbeAddOp2(v, OP_Null, 0, target); } 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); VdbeCoverage(v); }else{ sqlite3HaltConstraint(pParse, SQLITE_CONSTRAINT_TRIGGER, pExpr->affinity, pExpr->u.zToken, 0, 0); } break; } #endif } sqlite3ReleaseTempReg(pParse, regFree1); sqlite3ReleaseTempReg(pParse, regFree2); return inReg; } /* ** Factor out the code of the given expression to initialization time. ** ** If regDest>=0 then the result is always stored in that register and the ** result is not reusable. If regDest<0 then this routine is free to ** store the value whereever it wants. The register where the expression ** is stored is returned. When regDest<0, two identical expressions will ** code to the same register. */ int sqlite3ExprCodeAtInit( Parse *pParse, /* Parsing context */ Expr *pExpr, /* The expression to code when the VDBE initializes */ int regDest /* Store the value in this register */ ){ ExprList *p; assert( ConstFactorOk(pParse) ); p = pParse->pConstExpr; if( regDest<0 && p ){ struct ExprList_item *pItem; int i; for(pItem=p->a, i=p->nExpr; i>0; pItem++, i--){ if( pItem->reusable && sqlite3ExprCompare(0,pItem->pExpr,pExpr,-1)==0 ){ return pItem->u.iConstExprReg; } } } pExpr = sqlite3ExprDup(pParse->db, pExpr, 0); p = sqlite3ExprListAppend(pParse, p, pExpr); if( p ){ struct ExprList_item *pItem = &p->a[p->nExpr-1]; pItem->reusable = regDest<0; if( regDest<0 ) regDest = ++pParse->nMem; pItem->u.iConstExprReg = regDest; } pParse->pConstExpr = p; return regDest; } /* ** 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. ** ** If pExpr is a constant, then this routine might generate this ** code to fill the register in the initialization section of the ** VDBE program, in order to factor it out of the evaluation loop. */ int sqlite3ExprCodeTemp(Parse *pParse, Expr *pExpr, int *pReg){ int r2; pExpr = sqlite3ExprSkipCollate(pExpr); if( ConstFactorOk(pParse) && pExpr->op!=TK_REGISTER && sqlite3ExprIsConstantNotJoin(pExpr) ){ *pReg = 0; r2 = sqlite3ExprCodeAtInit(pParse, pExpr, -1); }else{ int r1 = sqlite3GetTempReg(pParse); 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. */ void 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!=0 || pParse->db->mallocFailed ); if( inReg!=target && pParse->pVdbe ){ sqlite3VdbeAddOp2(pParse->pVdbe, OP_SCopy, inReg, target); } } } /* ** Make a transient copy of expression pExpr and then code it using ** sqlite3ExprCode(). This routine works just like sqlite3ExprCode() ** except that the input expression is guaranteed to be unchanged. */ void sqlite3ExprCodeCopy(Parse *pParse, Expr *pExpr, int target){ sqlite3 *db = pParse->db; pExpr = sqlite3ExprDup(db, pExpr, 0); if( !db->mallocFailed ) sqlite3ExprCode(pParse, pExpr, target); sqlite3ExprDelete(db, pExpr); } /* ** Generate code that will evaluate expression pExpr and store the ** results in register target. The results are guaranteed to appear ** in register target. If the expression is constant, then this routine ** might choose to code the expression at initialization time. */ void sqlite3ExprCodeFactorable(Parse *pParse, Expr *pExpr, int target){ if( pParse->okConstFactor && sqlite3ExprIsConstantNotJoin(pExpr) ){ sqlite3ExprCodeAtInit(pParse, pExpr, target); }else{ sqlite3ExprCode(pParse, pExpr, target); } } /* ** Generate code that evaluates 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. */ void sqlite3ExprCodeAndCache(Parse *pParse, Expr *pExpr, int target){ Vdbe *v = pParse->pVdbe; int iMem; assert( target>0 ); assert( pExpr->op!=TK_REGISTER ); sqlite3ExprCode(pParse, pExpr, target); iMem = ++pParse->nMem; sqlite3VdbeAddOp2(v, OP_Copy, target, iMem); exprToRegister(pExpr, iMem); } /* ** 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. The number returned will ** usually be pList->nExpr but might be reduced if SQLITE_ECEL_OMITREF ** is defined. ** ** The SQLITE_ECEL_DUP flag prevents the arguments from being ** filled using OP_SCopy. OP_Copy must be used instead. ** ** The SQLITE_ECEL_FACTOR argument allows constant arguments to be ** factored out into initialization code. ** ** The SQLITE_ECEL_REF flag means that expressions in the list with ** ExprList.a[].u.x.iOrderByCol>0 have already been evaluated and stored ** in registers at srcReg, and so the value can be copied from there. ** If SQLITE_ECEL_OMITREF is also set, then the values with u.x.iOrderByCol>0 ** are simply omitted rather than being copied from srcReg. */ int sqlite3ExprCodeExprList( Parse *pParse, /* Parsing context */ ExprList *pList, /* The expression list to be coded */ int target, /* Where to write results */ int srcReg, /* Source registers if SQLITE_ECEL_REF */ u8 flags /* SQLITE_ECEL_* flags */ ){ struct ExprList_item *pItem; int i, j, n; u8 copyOp = (flags & SQLITE_ECEL_DUP) ? OP_Copy : OP_SCopy; Vdbe *v = pParse->pVdbe; assert( pList!=0 ); assert( target>0 ); assert( pParse->pVdbe!=0 ); /* Never gets this far otherwise */ n = pList->nExpr; if( !ConstFactorOk(pParse) ) flags &= ~SQLITE_ECEL_FACTOR; for(pItem=pList->a, i=0; ipExpr; #ifdef SQLITE_ENABLE_SORTER_REFERENCES if( pItem->bSorterRef ){ i--; n--; }else #endif if( (flags & SQLITE_ECEL_REF)!=0 && (j = pItem->u.x.iOrderByCol)>0 ){ if( flags & SQLITE_ECEL_OMITREF ){ i--; n--; }else{ sqlite3VdbeAddOp2(v, copyOp, j+srcReg-1, target+i); } }else if( (flags & SQLITE_ECEL_FACTOR)!=0 && sqlite3ExprIsConstantNotJoin(pExpr) ){ sqlite3ExprCodeAtInit(pParse, pExpr, target+i); }else{ int inReg = sqlite3ExprCodeTarget(pParse, pExpr, target+i); if( inReg!=target+i ){ VdbeOp *pOp; if( copyOp==OP_Copy && (pOp=sqlite3VdbeGetOp(v, -1))->opcode==OP_Copy && pOp->p1+pOp->p3+1==inReg && pOp->p2+pOp->p3+1==target+i ){ pOp->p3++; }else{ sqlite3VdbeAddOp2(v, copyOp, 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 ** elimination of x. ** ** The xJumpIf parameter determines details: ** ** NULL: Store the boolean result in reg[dest] ** sqlite3ExprIfTrue: Jump to dest if true ** sqlite3ExprIfFalse: Jump to dest if false ** ** The jumpIfNull parameter is ignored if xJumpIf is NULL. */ static void exprCodeBetween( Parse *pParse, /* Parsing and code generating context */ Expr *pExpr, /* The BETWEEN expression */ int dest, /* Jump destination or storage location */ void (*xJump)(Parse*,Expr*,int,int), /* Action to take */ 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 */ memset(&compLeft, 0, sizeof(Expr)); memset(&compRight, 0, sizeof(Expr)); memset(&exprAnd, 0, sizeof(Expr)); assert( !ExprHasProperty(pExpr, EP_xIsSelect) ); exprNodeCopy(&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, exprCodeVector(pParse, &exprX, ®Free1)); if( xJump ){ xJump(pParse, &exprAnd, dest, jumpIfNull); }else{ /* Mark the expression is being from the ON or USING clause of a join ** so that the sqlite3ExprCodeTarget() routine will not attempt to move ** it into the Parse.pConstExpr list. We should use a new bit for this, ** for clarity, but we are out of bits in the Expr.flags field so we ** have to reuse the EP_FromJoin bit. Bummer. */ exprX.flags |= EP_FromJoin; sqlite3ExprCodeTarget(pParse, &exprAnd, dest); } sqlite3ReleaseTempReg(pParse, regFree1); /* Ensure adequate test coverage */ testcase( xJump==sqlite3ExprIfTrue && jumpIfNull==0 && regFree1==0 ); testcase( xJump==sqlite3ExprIfTrue && jumpIfNull==0 && regFree1!=0 ); testcase( xJump==sqlite3ExprIfTrue && jumpIfNull!=0 && regFree1==0 ); testcase( xJump==sqlite3ExprIfTrue && jumpIfNull!=0 && regFree1!=0 ); testcase( xJump==sqlite3ExprIfFalse && jumpIfNull==0 && regFree1==0 ); testcase( xJump==sqlite3ExprIfFalse && jumpIfNull==0 && regFree1!=0 ); testcase( xJump==sqlite3ExprIfFalse && jumpIfNull!=0 && regFree1==0 ); testcase( xJump==sqlite3ExprIfFalse && jumpIfNull!=0 && regFree1!=0 ); testcase( xJump==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: case TK_OR: { Expr *pAlt = sqlite3ExprSimplifiedAndOr(pExpr); if( pAlt!=pExpr ){ sqlite3ExprIfTrue(pParse, pAlt, dest, jumpIfNull); }else if( op==TK_AND ){ int d2 = sqlite3VdbeMakeLabel(pParse); testcase( jumpIfNull==0 ); sqlite3ExprIfFalse(pParse, pExpr->pLeft, d2, jumpIfNull^SQLITE_JUMPIFNULL); sqlite3ExprIfTrue(pParse, pExpr->pRight, dest, jumpIfNull); sqlite3VdbeResolveLabel(v, d2); }else{ 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_TRUTH: { int isNot; /* IS NOT TRUE or IS NOT FALSE */ int isTrue; /* IS TRUE or IS NOT TRUE */ testcase( jumpIfNull==0 ); isNot = pExpr->op2==TK_ISNOT; isTrue = sqlite3ExprTruthValue(pExpr->pRight); testcase( isTrue && isNot ); testcase( !isTrue && isNot ); if( isTrue ^ isNot ){ sqlite3ExprIfTrue(pParse, pExpr->pLeft, dest, isNot ? SQLITE_JUMPIFNULL : 0); }else{ sqlite3ExprIfFalse(pParse, pExpr->pLeft, dest, isNot ? SQLITE_JUMPIFNULL : 0); } break; } case TK_IS: case TK_ISNOT: testcase( op==TK_IS ); testcase( op==TK_ISNOT ); op = (op==TK_IS) ? TK_EQ : TK_NE; jumpIfNull = SQLITE_NULLEQ; /* Fall thru */ case TK_LT: case TK_LE: case TK_GT: case TK_GE: case TK_NE: case TK_EQ: { if( sqlite3ExprIsVector(pExpr->pLeft) ) goto default_expr; 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); assert(TK_LT==OP_Lt); testcase(op==OP_Lt); VdbeCoverageIf(v,op==OP_Lt); assert(TK_LE==OP_Le); testcase(op==OP_Le); VdbeCoverageIf(v,op==OP_Le); assert(TK_GT==OP_Gt); testcase(op==OP_Gt); VdbeCoverageIf(v,op==OP_Gt); assert(TK_GE==OP_Ge); testcase(op==OP_Ge); VdbeCoverageIf(v,op==OP_Ge); assert(TK_EQ==OP_Eq); testcase(op==OP_Eq); VdbeCoverageIf(v, op==OP_Eq && jumpIfNull==SQLITE_NULLEQ); VdbeCoverageIf(v, op==OP_Eq && jumpIfNull!=SQLITE_NULLEQ); assert(TK_NE==OP_Ne); testcase(op==OP_Ne); VdbeCoverageIf(v, op==OP_Ne && jumpIfNull==SQLITE_NULLEQ); VdbeCoverageIf(v, op==OP_Ne && jumpIfNull!=SQLITE_NULLEQ); testcase( regFree1==0 ); testcase( regFree2==0 ); break; } case TK_ISNULL: case TK_NOTNULL: { assert( TK_ISNULL==OP_IsNull ); testcase( op==TK_ISNULL ); assert( TK_NOTNULL==OP_NotNull ); testcase( op==TK_NOTNULL ); r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free1); sqlite3VdbeAddOp2(v, op, r1, dest); VdbeCoverageIf(v, op==TK_ISNULL); VdbeCoverageIf(v, op==TK_NOTNULL); testcase( regFree1==0 ); break; } case TK_BETWEEN: { testcase( jumpIfNull==0 ); exprCodeBetween(pParse, pExpr, dest, sqlite3ExprIfTrue, jumpIfNull); break; } #ifndef SQLITE_OMIT_SUBQUERY case TK_IN: { int destIfFalse = sqlite3VdbeMakeLabel(pParse); int destIfNull = jumpIfNull ? dest : destIfFalse; sqlite3ExprCodeIN(pParse, pExpr, destIfFalse, destIfNull); sqlite3VdbeGoto(v, dest); sqlite3VdbeResolveLabel(v, destIfFalse); break; } #endif default: { default_expr: if( ExprAlwaysTrue(pExpr) ){ sqlite3VdbeGoto(v, dest); }else if( ExprAlwaysFalse(pExpr) ){ /* No-op */ }else{ r1 = sqlite3ExprCodeTemp(pParse, pExpr, ®Free1); sqlite3VdbeAddOp3(v, OP_If, r1, dest, jumpIfNull!=0); VdbeCoverage(v); 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: case TK_OR: { Expr *pAlt = sqlite3ExprSimplifiedAndOr(pExpr); if( pAlt!=pExpr ){ sqlite3ExprIfFalse(pParse, pAlt, dest, jumpIfNull); }else if( pExpr->op==TK_AND ){ testcase( jumpIfNull==0 ); sqlite3ExprIfFalse(pParse, pExpr->pLeft, dest, jumpIfNull); sqlite3ExprIfFalse(pParse, pExpr->pRight, dest, jumpIfNull); }else{ int d2 = sqlite3VdbeMakeLabel(pParse); testcase( jumpIfNull==0 ); sqlite3ExprIfTrue(pParse, pExpr->pLeft, d2, jumpIfNull^SQLITE_JUMPIFNULL); sqlite3ExprIfFalse(pParse, pExpr->pRight, dest, jumpIfNull); sqlite3VdbeResolveLabel(v, d2); } break; } case TK_NOT: { testcase( jumpIfNull==0 ); sqlite3ExprIfTrue(pParse, pExpr->pLeft, dest, jumpIfNull); break; } case TK_TRUTH: { int isNot; /* IS NOT TRUE or IS NOT FALSE */ int isTrue; /* IS TRUE or IS NOT TRUE */ testcase( jumpIfNull==0 ); isNot = pExpr->op2==TK_ISNOT; isTrue = sqlite3ExprTruthValue(pExpr->pRight); testcase( isTrue && isNot ); testcase( !isTrue && isNot ); if( isTrue ^ isNot ){ /* IS TRUE and IS NOT FALSE */ sqlite3ExprIfFalse(pParse, pExpr->pLeft, dest, isNot ? 0 : SQLITE_JUMPIFNULL); }else{ /* IS FALSE and IS NOT TRUE */ sqlite3ExprIfTrue(pParse, pExpr->pLeft, dest, isNot ? 0 : SQLITE_JUMPIFNULL); } break; } case TK_IS: case TK_ISNOT: testcase( pExpr->op==TK_IS ); testcase( pExpr->op==TK_ISNOT ); op = (pExpr->op==TK_IS) ? TK_NE : TK_EQ; jumpIfNull = SQLITE_NULLEQ; /* Fall thru */ case TK_LT: case TK_LE: case TK_GT: case TK_GE: case TK_NE: case TK_EQ: { if( sqlite3ExprIsVector(pExpr->pLeft) ) goto default_expr; 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); assert(TK_LT==OP_Lt); testcase(op==OP_Lt); VdbeCoverageIf(v,op==OP_Lt); assert(TK_LE==OP_Le); testcase(op==OP_Le); VdbeCoverageIf(v,op==OP_Le); assert(TK_GT==OP_Gt); testcase(op==OP_Gt); VdbeCoverageIf(v,op==OP_Gt); assert(TK_GE==OP_Ge); testcase(op==OP_Ge); VdbeCoverageIf(v,op==OP_Ge); assert(TK_EQ==OP_Eq); testcase(op==OP_Eq); VdbeCoverageIf(v, op==OP_Eq && jumpIfNull!=SQLITE_NULLEQ); VdbeCoverageIf(v, op==OP_Eq && jumpIfNull==SQLITE_NULLEQ); assert(TK_NE==OP_Ne); testcase(op==OP_Ne); VdbeCoverageIf(v, op==OP_Ne && jumpIfNull!=SQLITE_NULLEQ); VdbeCoverageIf(v, op==OP_Ne && jumpIfNull==SQLITE_NULLEQ); testcase( regFree1==0 ); testcase( regFree2==0 ); break; } case TK_ISNULL: case TK_NOTNULL: { r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free1); sqlite3VdbeAddOp2(v, op, r1, dest); testcase( op==TK_ISNULL ); VdbeCoverageIf(v, op==TK_ISNULL); testcase( op==TK_NOTNULL ); VdbeCoverageIf(v, op==TK_NOTNULL); testcase( regFree1==0 ); break; } case TK_BETWEEN: { testcase( jumpIfNull==0 ); exprCodeBetween(pParse, pExpr, dest, sqlite3ExprIfFalse, jumpIfNull); break; } #ifndef SQLITE_OMIT_SUBQUERY case TK_IN: { if( jumpIfNull ){ sqlite3ExprCodeIN(pParse, pExpr, dest, dest); }else{ int destIfNull = sqlite3VdbeMakeLabel(pParse); sqlite3ExprCodeIN(pParse, pExpr, dest, destIfNull); sqlite3VdbeResolveLabel(v, destIfNull); } break; } #endif default: { default_expr: if( ExprAlwaysFalse(pExpr) ){ sqlite3VdbeGoto(v, dest); }else if( ExprAlwaysTrue(pExpr) ){ /* no-op */ }else{ r1 = sqlite3ExprCodeTemp(pParse, pExpr, ®Free1); sqlite3VdbeAddOp3(v, OP_IfNot, r1, dest, jumpIfNull!=0); VdbeCoverage(v); testcase( regFree1==0 ); testcase( jumpIfNull==0 ); } break; } } sqlite3ReleaseTempReg(pParse, regFree1); sqlite3ReleaseTempReg(pParse, regFree2); } /* ** Like sqlite3ExprIfFalse() except that a copy is made of pExpr before ** code generation, and that copy is deleted after code generation. This ** ensures that the original pExpr is unchanged. */ void sqlite3ExprIfFalseDup(Parse *pParse, Expr *pExpr, int dest,int jumpIfNull){ sqlite3 *db = pParse->db; Expr *pCopy = sqlite3ExprDup(db, pExpr, 0); if( db->mallocFailed==0 ){ sqlite3ExprIfFalse(pParse, pCopy, dest, jumpIfNull); } sqlite3ExprDelete(db, pCopy); } /* ** Expression pVar is guaranteed to be an SQL variable. pExpr may be any ** type of expression. ** ** If pExpr is a simple SQL value - an integer, real, string, blob ** or NULL value - then the VDBE currently being prepared is configured ** to re-prepare each time a new value is bound to variable pVar. ** ** Additionally, if pExpr is a simple SQL value and the value is the ** same as that currently bound to variable pVar, non-zero is returned. ** Otherwise, if the values are not the same or if pExpr is not a simple ** SQL value, zero is returned. */ static int exprCompareVariable(Parse *pParse, Expr *pVar, Expr *pExpr){ int res = 0; int iVar; sqlite3_value *pL, *pR = 0; sqlite3ValueFromExpr(pParse->db, pExpr, SQLITE_UTF8, SQLITE_AFF_BLOB, &pR); if( pR ){ iVar = pVar->iColumn; sqlite3VdbeSetVarmask(pParse->pVdbe, iVar); pL = sqlite3VdbeGetBoundValue(pParse->pReprepare, iVar, SQLITE_AFF_BLOB); if( pL ){ if( sqlite3_value_type(pL)==SQLITE_TEXT ){ sqlite3_value_text(pL); /* Make sure the encoding is UTF-8 */ } res = 0==sqlite3MemCompare(pL, pR, 0); } sqlite3ValueFree(pR); sqlite3ValueFree(pL); } return res; } /* ** 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. ** ** If pParse is not NULL then TK_VARIABLE terms in pA with bindings in ** pParse->pReprepare can be matched against literals in pB. The ** pParse->pVdbe->expmask bitmask is updated for each variable referenced. ** If pParse is NULL (the normal case) then any TK_VARIABLE term in ** Argument pParse should normally be NULL. If it is not NULL and pA or ** pB causes a return value of 2. */ int sqlite3ExprCompare(Parse *pParse, Expr *pA, Expr *pB, int iTab){ u32 combinedFlags; if( pA==0 || pB==0 ){ return pB==pA ? 0 : 2; } if( pParse && pA->op==TK_VARIABLE && exprCompareVariable(pParse, pA, pB) ){ return 0; } combinedFlags = pA->flags | pB->flags; if( combinedFlags & EP_IntValue ){ if( (pA->flags&pB->flags&EP_IntValue)!=0 && pA->u.iValue==pB->u.iValue ){ return 0; } return 2; } if( pA->op!=pB->op || pA->op==TK_RAISE ){ if( pA->op==TK_COLLATE && sqlite3ExprCompare(pParse, pA->pLeft,pB,iTab)<2 ){ return 1; } if( pB->op==TK_COLLATE && sqlite3ExprCompare(pParse, pA,pB->pLeft,iTab)<2 ){ return 1; } return 2; } if( pA->op!=TK_COLUMN && pA->op!=TK_AGG_COLUMN && pA->u.zToken ){ if( pA->op==TK_FUNCTION ){ if( sqlite3StrICmp(pA->u.zToken,pB->u.zToken)!=0 ) return 2; #ifndef SQLITE_OMIT_WINDOWFUNC /* Justification for the assert(): ** window functions have p->op==TK_FUNCTION but aggregate functions ** have p->op==TK_AGG_FUNCTION. So any comparison between an aggregate ** function and a window function should have failed before reaching ** this point. And, it is not possible to have a window function and ** a scalar function with the same name and number of arguments. So ** if we reach this point, either A and B both window functions or ** neither are a window functions. */ assert( ExprHasProperty(pA,EP_WinFunc)==ExprHasProperty(pB,EP_WinFunc) ); if( ExprHasProperty(pA,EP_WinFunc) ){ if( sqlite3WindowCompare(pParse,pA->y.pWin,pB->y.pWin)!=0 ) return 2; } #endif }else if( pA->op==TK_NULL ){ return 0; }else if( pA->op==TK_COLLATE ){ if( sqlite3_stricmp(pA->u.zToken,pB->u.zToken)!=0 ) return 2; }else if( ALWAYS(pB->u.zToken!=0) && strcmp(pA->u.zToken,pB->u.zToken)!=0 ){ return 2; } #ifndef SQLITE_OMIT_WINDOWFUNC else if( pA->op==TK_AGG_FUNCTION ){ assert( ExprHasProperty(pA, EP_WinFunc)==0 ); if( sqlite3ExprCompare(pParse, pA->y.pFilter, pB->y.pFilter, iTab) ){ return 2; } } #endif } if( (pA->flags & EP_Distinct)!=(pB->flags & EP_Distinct) ) return 2; if( (combinedFlags & EP_TokenOnly)==0 ){ if( combinedFlags & EP_xIsSelect ) return 2; if( (combinedFlags & EP_FixedCol)==0 && sqlite3ExprCompare(pParse, pA->pLeft, pB->pLeft, iTab) ) return 2; if( sqlite3ExprCompare(pParse, pA->pRight, pB->pRight, iTab) ) return 2; if( sqlite3ExprListCompare(pA->x.pList, pB->x.pList, iTab) ) return 2; if( pA->op!=TK_STRING && pA->op!=TK_TRUEFALSE && (combinedFlags & EP_Reduced)==0 ){ if( pA->iColumn!=pB->iColumn ) return 2; if( pA->op2!=pB->op2 ) return 2; if( pA->iTable!=pB->iTable && (pA->iTable!=iTab || NEVER(pB->iTable>=0)) ) return 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; inExpr; 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(0, pExprA, pExprB, iTab) ) return 1; } return 0; } /* ** Like sqlite3ExprCompare() except COLLATE operators at the top-level ** are ignored. */ int sqlite3ExprCompareSkip(Expr *pA, Expr *pB, int iTab){ return sqlite3ExprCompare(0, sqlite3ExprSkipCollate(pA), sqlite3ExprSkipCollate(pB), iTab); } /* ** Return non-zero if Expr p can only be true if pNN is not NULL. */ static int exprImpliesNotNull( Parse *pParse, /* Parsing context */ Expr *p, /* The expression to be checked */ Expr *pNN, /* The expression that is NOT NULL */ int iTab, /* Table being evaluated */ int seenNot /* True if p is an operand of NOT */ ){ assert( p ); assert( pNN ); if( sqlite3ExprCompare(pParse, p, pNN, iTab)==0 ) return 1; switch( p->op ){ case TK_IN: { if( seenNot && ExprHasProperty(p, EP_xIsSelect) ) return 0; assert( ExprHasProperty(p,EP_xIsSelect) || (p->x.pList!=0 && p->x.pList->nExpr>0) ); return exprImpliesNotNull(pParse, p->pLeft, pNN, iTab, seenNot); } case TK_BETWEEN: { ExprList *pList = p->x.pList; assert( pList!=0 ); assert( pList->nExpr==2 ); if( seenNot ) return 0; if( exprImpliesNotNull(pParse, pList->a[0].pExpr, pNN, iTab, seenNot) || exprImpliesNotNull(pParse, pList->a[1].pExpr, pNN, iTab, seenNot) ){ return 1; } return exprImpliesNotNull(pParse, p->pLeft, pNN, iTab, seenNot); } case TK_EQ: case TK_NE: case TK_LT: case TK_LE: case TK_GT: case TK_GE: case TK_PLUS: case TK_MINUS: case TK_STAR: case TK_REM: case TK_BITAND: case TK_BITOR: case TK_SLASH: case TK_LSHIFT: case TK_RSHIFT: case TK_CONCAT: { if( exprImpliesNotNull(pParse, p->pRight, pNN, iTab, seenNot) ) return 1; /* Fall thru into the next case */ } case TK_SPAN: case TK_COLLATE: case TK_BITNOT: case TK_UPLUS: case TK_UMINUS: { return exprImpliesNotNull(pParse, p->pLeft, pNN, iTab, seenNot); } case TK_TRUTH: { if( seenNot ) return 0; if( p->op2!=TK_IS ) return 0; return exprImpliesNotNull(pParse, p->pLeft, pNN, iTab, seenNot); } case TK_NOT: { return exprImpliesNotNull(pParse, p->pLeft, pNN, iTab, 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. ** ** If pParse is not NULL, then the values of bound variables in pE1 are ** compared against literal values in pE2 and pParse->pVdbe->expmask is ** modified to record which bound variables are referenced. If pParse ** is NULL, then false will be returned if pE1 contains any bound variables. ** ** 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(Parse *pParse, Expr *pE1, Expr *pE2, int iTab){ if( sqlite3ExprCompare(pParse, pE1, pE2, iTab)==0 ){ return 1; } if( pE2->op==TK_OR && (sqlite3ExprImpliesExpr(pParse, pE1, pE2->pLeft, iTab) || sqlite3ExprImpliesExpr(pParse, pE1, pE2->pRight, iTab) ) ){ return 1; } if( pE2->op==TK_NOTNULL && exprImpliesNotNull(pParse, pE1, pE2->pLeft, iTab, 0) ){ return 1; } return 0; } /* ** This is the Expr node callback for sqlite3ExprImpliesNotNullRow(). ** If the expression node requires that the table at pWalker->iCur ** have one or more non-NULL column, then set pWalker->eCode to 1 and abort. ** ** This routine controls an optimization. False positives (setting ** pWalker->eCode to 1 when it should not be) are deadly, but false-negatives ** (never setting pWalker->eCode) is a harmless missed optimization. */ static int impliesNotNullRow(Walker *pWalker, Expr *pExpr){ testcase( pExpr->op==TK_AGG_COLUMN ); testcase( pExpr->op==TK_AGG_FUNCTION ); if( ExprHasProperty(pExpr, EP_FromJoin) ) return WRC_Prune; switch( pExpr->op ){ case TK_ISNOT: case TK_NOT: case TK_ISNULL: case TK_NOTNULL: case TK_IS: case TK_OR: case TK_CASE: case TK_IN: case TK_FUNCTION: testcase( pExpr->op==TK_ISNOT ); testcase( pExpr->op==TK_NOT ); testcase( pExpr->op==TK_ISNULL ); testcase( pExpr->op==TK_NOTNULL ); testcase( pExpr->op==TK_IS ); testcase( pExpr->op==TK_OR ); testcase( pExpr->op==TK_CASE ); testcase( pExpr->op==TK_IN ); testcase( pExpr->op==TK_FUNCTION ); return WRC_Prune; case TK_COLUMN: if( pWalker->u.iCur==pExpr->iTable ){ pWalker->eCode = 1; return WRC_Abort; } return WRC_Prune; /* Virtual tables are allowed to use constraints like x=NULL. So ** a term of the form x=y does not prove that y is not null if x ** is the column of a virtual table */ case TK_EQ: case TK_NE: case TK_LT: case TK_LE: case TK_GT: case TK_GE: testcase( pExpr->op==TK_EQ ); testcase( pExpr->op==TK_NE ); testcase( pExpr->op==TK_LT ); testcase( pExpr->op==TK_LE ); testcase( pExpr->op==TK_GT ); testcase( pExpr->op==TK_GE ); if( (pExpr->pLeft->op==TK_COLUMN && IsVirtual(pExpr->pLeft->y.pTab)) || (pExpr->pRight->op==TK_COLUMN && IsVirtual(pExpr->pRight->y.pTab)) ){ return WRC_Prune; } default: return WRC_Continue; } } /* ** Return true (non-zero) if expression p can only be true if at least ** one column of table iTab is non-null. In other words, return true ** if expression p will always be NULL or false if every column of iTab ** is NULL. ** ** False negatives are acceptable. In other words, it is ok to return ** zero even if expression p will never be true of every column of iTab ** is NULL. A false negative is merely a missed optimization opportunity. ** ** False positives are not allowed, however. A false positive may result ** in an incorrect answer. ** ** Terms of p that are marked with EP_FromJoin (and hence that come from ** the ON or USING clauses of LEFT JOINS) are excluded from the analysis. ** ** This routine is used to check if a LEFT JOIN can be converted into ** an ordinary JOIN. The p argument is the WHERE clause. If the WHERE ** clause requires that some column of the right table of the LEFT JOIN ** be non-NULL, then the LEFT JOIN can be safely converted into an ** ordinary join. */ int sqlite3ExprImpliesNonNullRow(Expr *p, int iTab){ Walker w; p = sqlite3ExprSkipCollate(p); while( p ){ if( p->op==TK_NOTNULL ){ p = p->pLeft; }else if( p->op==TK_AND ){ if( sqlite3ExprImpliesNonNullRow(p->pLeft, iTab) ) return 1; p = p->pRight; }else{ break; } } w.xExprCallback = impliesNotNullRow; w.xSelectCallback = 0; w.xSelectCallback2 = 0; w.eCode = 0; w.u.iCur = iTab; sqlite3WalkExpr(&w, p); return w.eCode; } /* ** An instance of the following structure is used by the tree walker ** to determine if an expression can be evaluated by reference to the ** index only, without having to do a search for the corresponding ** table entry. The IdxCover.pIdx field is the index. IdxCover.iCur ** is the cursor for the table. */ struct IdxCover { Index *pIdx; /* The index to be tested for coverage */ int iCur; /* Cursor number for the table corresponding to the index */ }; /* ** Check to see if there are references to columns in table ** pWalker->u.pIdxCover->iCur can be satisfied using the index ** pWalker->u.pIdxCover->pIdx. */ static int exprIdxCover(Walker *pWalker, Expr *pExpr){ if( pExpr->op==TK_COLUMN && pExpr->iTable==pWalker->u.pIdxCover->iCur && sqlite3ColumnOfIndex(pWalker->u.pIdxCover->pIdx, pExpr->iColumn)<0 ){ pWalker->eCode = 1; return WRC_Abort; } return WRC_Continue; } /* ** Determine if an index pIdx on table with cursor iCur contains will ** the expression pExpr. Return true if the index does cover the ** expression and false if the pExpr expression references table columns ** that are not found in the index pIdx. ** ** An index covering an expression means that the expression can be ** evaluated using only the index and without having to lookup the ** corresponding table entry. */ int sqlite3ExprCoveredByIndex( Expr *pExpr, /* The index to be tested */ int iCur, /* The cursor number for the corresponding table */ Index *pIdx /* The index that might be used for coverage */ ){ Walker w; struct IdxCover xcov; memset(&w, 0, sizeof(w)); xcov.iCur = iCur; xcov.pIdx = pIdx; w.xExprCallback = exprIdxCover; w.u.pIdxCover = &xcov; sqlite3WalkExpr(&w, pExpr); return !w.eCode; } /* ** 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; int nSrc = pSrc ? pSrc->nSrc : 0; for(i=0; iiTable==pSrc->a[i].iCursor ) break; } if( inThis++; }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 ); w.xExprCallback = exprSrcCount; w.xSelectCallback = 0; 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->uNC.pAggInfo; assert( pNC->ncFlags & NC_UAggInfo ); 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; inSrc; 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; knColumn; 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->y.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; jpExpr; 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; inFunc; i++, pItem++){ if( sqlite3ExprCompare(0, 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, 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(pSelect); pWalker->walkerDepth++; return WRC_Continue; } static void analyzeAggregatesInSelectEnd(Walker *pWalker, Select *pSelect){ UNUSED_PARAMETER(pSelect); pWalker->walkerDepth--; } /* ** 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; w.xExprCallback = analyzeAggregate; w.xSelectCallback = analyzeAggregatesInSelect; w.xSelectCallback2 = analyzeAggregatesInSelectEnd; w.walkerDepth = 0; w.u.pNC = pNC; w.pParse = 0; 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; inExpr; 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. */ void sqlite3ReleaseTempReg(Parse *pParse, int iReg){ if( iReg && pParse->nTempRegaTempReg) ){ pParse->aTempReg[pParse->nTempReg++] = iReg; } } /* ** Allocate or deallocate a block of nReg consecutive registers. */ int sqlite3GetTempRange(Parse *pParse, int nReg){ int i, n; if( nReg==1 ) return sqlite3GetTempReg(pParse); i = pParse->iRangeReg; n = pParse->nRangeReg; if( nReg<=n ){ pParse->iRangeReg += nReg; pParse->nRangeReg -= nReg; }else{ i = pParse->nMem+1; pParse->nMem += nReg; } return i; } void sqlite3ReleaseTempRange(Parse *pParse, int iReg, int nReg){ if( nReg==1 ){ sqlite3ReleaseTempReg(pParse, iReg); return; } 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; } /* ** Validate that no temporary register falls within the range of ** iFirst..iLast, inclusive. This routine is only call from within assert() ** statements. */ #ifdef SQLITE_DEBUG int sqlite3NoTempsInRange(Parse *pParse, int iFirst, int iLast){ int i; if( pParse->nRangeReg>0 && pParse->iRangeReg+pParse->nRangeReg > iFirst && pParse->iRangeReg <= iLast ){ return 0; } for(i=0; inTempReg; i++){ if( pParse->aTempReg[i]>=iFirst && pParse->aTempReg[i]<=iLast ){ return 0; } } return 1; } #endif /* SQLITE_DEBUG */