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Diffstat (limited to 'lib/libsqlite3/src/expr.c')
| -rw-r--r-- | lib/libsqlite3/src/expr.c | 4200 |
1 files changed, 0 insertions, 4200 deletions
diff --git a/lib/libsqlite3/src/expr.c b/lib/libsqlite3/src/expr.c deleted file mode 100644 index b39dea2ea14..00000000000 --- a/lib/libsqlite3/src/expr.c +++ /dev/null @@ -1,4200 +0,0 @@ -/* -** 2001 September 15 -** -** The author disclaims copyright to this source code. In place of -** a legal notice, here is a blessing: -** -** May you do good and not evil. -** May you find forgiveness for yourself and forgive others. -** May you share freely, never taking more than you give. -** -************************************************************************* -** This file contains routines used for analyzing expressions and -** for generating VDBE code that evaluates expressions in SQLite. -*/ -#include "sqliteInt.h" - -/* -** Return the 'affinity' of the expression pExpr if any. -** -** If pExpr is a column, a reference to a column via an 'AS' alias, -** or a sub-select with a column as the return value, then the -** affinity of that column is returned. Otherwise, 0x00 is returned, -** indicating no affinity for the expression. -** -** i.e. the WHERE clause 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; - pExpr = sqlite3ExprSkipCollate(pExpr); - if( pExpr->flags & EP_Generic ) return 0; - op = pExpr->op; - if( op==TK_SELECT ){ - assert( pExpr->flags&EP_xIsSelect ); - return sqlite3ExprAffinity(pExpr->x.pSelect->pEList->a[0].pExpr); - } -#ifndef SQLITE_OMIT_CAST - if( op==TK_CAST ){ - assert( !ExprHasProperty(pExpr, EP_IntValue) ); - return sqlite3AffinityType(pExpr->u.zToken, 0); - } -#endif - if( (op==TK_AGG_COLUMN || op==TK_COLUMN || op==TK_REGISTER) - && pExpr->pTab!=0 - ){ - /* op==TK_REGISTER && pExpr->pTab!=0 happens when pExpr was originally - ** a TK_COLUMN but was previously evaluated and cached in a register */ - int j = pExpr->iColumn; - if( j<0 ) return SQLITE_AFF_INTEGER; - assert( pExpr->pTab && j<pExpr->pTab->nCol ); - return pExpr->pTab->aCol[j].affinity; - } - return pExpr->affinity; -} - -/* -** Set the collating sequence for expression pExpr to be the collating -** sequence named by pToken. Return a pointer to a new Expr node that -** implements the COLLATE operator. -** -** If a memory allocation error occurs, that fact is recorded in pParse->db -** and the pExpr parameter is returned unchanged. -*/ -Expr *sqlite3ExprAddCollateToken( - Parse *pParse, /* 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 ); - s.z = zC; - s.n = sqlite3Strlen30(s.z); - 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) ){ - 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. -** -** 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_CAST || op==TK_UPLUS ){ - p = p->pLeft; - continue; - } - if( op==TK_COLLATE || (op==TK_REGISTER && p->op2==TK_COLLATE) ){ - pColl = sqlite3GetCollSeq(pParse, ENC(db), 0, p->u.zToken); - break; - } - if( (op==TK_AGG_COLUMN || op==TK_COLUMN - || op==TK_REGISTER || op==TK_TRIGGER) - && p->pTab!=0 - ){ - /* op==TK_REGISTER && p->pTab!=0 happens when pExpr was originally - ** a TK_COLUMN but was previously evaluated and cached in a register */ - int j = p->iColumn; - if( j>=0 ){ - const char *zColl = p->pTab->aCol[j].zColl; - pColl = sqlite3FindCollSeq(db, ENC(db), zColl, 0); - } - break; - } - if( p->flags & EP_Collate ){ - if( 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(i<p->x.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; -} - -/* -** 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 ){ - 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; -} - -#if SQLITE_MAX_EXPR_DEPTH>0 -/* -** Check that argument nHeight is less than or equal to the maximum -** expression depth allowed. If it is not, leave an error message in -** pParse. -*/ -int sqlite3ExprCheckHeight(Parse *pParse, int nHeight){ - int rc = SQLITE_OK; - int mxHeight = pParse->db->aLimit[SQLITE_LIMIT_EXPR_DEPTH]; - if( nHeight>mxHeight ){ - sqlite3ErrorMsg(pParse, - "Expression tree is too large (maximum depth %d)", mxHeight - ); - rc = SQLITE_ERROR; - } - return rc; -} - -/* The following three functions, heightOfExpr(), heightOfExprList() -** and heightOfSelect(), are used to determine the maximum height -** of any expression tree referenced by the structure passed as the -** first argument. -** -** If this maximum height is greater than the current value pointed -** to by pnHeight, the second parameter, then set *pnHeight to that -** value. -*/ -static void heightOfExpr(Expr *p, int *pnHeight){ - if( p ){ - if( p->nHeight>*pnHeight ){ - *pnHeight = p->nHeight; - } - } -} -static void heightOfExprList(ExprList *p, int *pnHeight){ - if( p ){ - int i; - for(i=0; i<p->nExpr; i++){ - heightOfExpr(p->a[i].pExpr, pnHeight); - } - } -} -static void heightOfSelect(Select *p, int *pnHeight){ - if( p ){ - heightOfExpr(p->pWhere, pnHeight); - heightOfExpr(p->pHaving, pnHeight); - heightOfExpr(p->pLimit, pnHeight); - heightOfExpr(p->pOffset, pnHeight); - heightOfExprList(p->pEList, pnHeight); - heightOfExprList(p->pGroupBy, pnHeight); - heightOfExprList(p->pOrderBy, pnHeight); - heightOfSelect(p->pPrior, pnHeight); - } -} - -/* -** Set the Expr.nHeight variable in the structure passed as an -** argument. An expression with no children, Expr.pList or -** Expr.pSelect member has a height of 1. Any other expression -** has a height equal to the maximum height of any other -** referenced Expr plus one. -** -** 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 sqlite3DbMallocZero() (may be null) */ - int op, /* Expression opcode */ - const Token *pToken, /* Token argument. Might be NULL */ - int dequote /* True to dequote */ -){ - Expr *pNew; - int nExtra = 0; - int iValue = 0; - - if( pToken ){ - if( op!=TK_INTEGER || pToken->z==0 - || sqlite3GetInt32(pToken->z, &iValue)==0 ){ - nExtra = pToken->n+1; - assert( iValue>=0 ); - } - } - pNew = sqlite3DbMallocZero(db, sizeof(Expr)+nExtra); - if( pNew ){ - pNew->op = (u8)op; - pNew->iAgg = -1; - if( pToken ){ - if( nExtra==0 ){ - pNew->flags |= EP_IntValue; - pNew->u.iValue = iValue; - }else{ - int c; - pNew->u.zToken = (char*)&pNew[1]; - assert( pToken->z!=0 || pToken->n==0 ); - if( pToken->n ) memcpy(pNew->u.zToken, pToken->z, pToken->n); - pNew->u.zToken[pToken->n] = 0; - if( dequote && nExtra>=3 - && ((c = pToken->z[0])=='\'' || c=='"' || c=='[' || c=='`') ){ - sqlite3Dequote(pNew->u.zToken); - if( c=='"' ) pNew->flags |= EP_DblQuoted; - } - } - } -#if SQLITE_MAX_EXPR_DEPTH>0 - pNew->nHeight = 1; -#endif - } - return pNew; -} - -/* -** Allocate a new expression node from a zero-terminated token that has -** already been dequoted. -*/ -Expr *sqlite3Expr( - sqlite3 *db, /* Handle for sqlite3DbMallocZero() (may be null) */ - int op, /* Expression opcode */ - const char *zToken /* Token argument. Might be NULL */ -){ - Token x; - x.z = zToken; - x.n = zToken ? sqlite3Strlen30(zToken) : 0; - return sqlite3ExprAlloc(db, op, &x, 0); -} - -/* -** Attach subtrees pLeft and pRight to the Expr node pRoot. -** -** If pRoot==NULL that means that a memory allocation error has occurred. -** In that case, delete the subtrees pLeft and pRight. -*/ -void sqlite3ExprAttachSubtrees( - sqlite3 *db, - Expr *pRoot, - Expr *pLeft, - Expr *pRight -){ - if( pRoot==0 ){ - assert( db->mallocFailed ); - sqlite3ExprDelete(db, pLeft); - sqlite3ExprDelete(db, pRight); - }else{ - if( pRight ){ - pRoot->pRight = pRight; - pRoot->flags |= EP_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 */ - const Token *pToken /* Argument token */ -){ - Expr *p; - if( op==TK_AND && pLeft && pRight && pParse->nErr==0 ){ - /* Take advantage of short-circuit false optimization for AND */ - p = sqlite3ExprAnd(pParse->db, pLeft, pRight); - }else{ - p = sqlite3ExprAlloc(pParse->db, op, pToken, 1); - sqlite3ExprAttachSubtrees(pParse->db, p, pLeft, pRight); - } - if( p ) { - sqlite3ExprCheckHeight(pParse, p->nHeight); - } - return p; -} - -/* -** If the expression is always either TRUE or FALSE (respectively), -** then return 1. If one cannot determine the truth value of the -** expression at compile-time return 0. -** -** This is an optimization. If is OK to return 0 here even if -** the expression really is always false or false (a false negative). -** But it is a bug to return 1 if the expression might have different -** boolean values in different circumstances (a false positive.) -** -** Note that if the expression is part of conditional for a -** LEFT JOIN, then we cannot determine at compile-time whether or not -** is it true or false, so always return 0. -*/ -static int exprAlwaysTrue(Expr *p){ - int v = 0; - if( ExprHasProperty(p, EP_FromJoin) ) return 0; - if( !sqlite3ExprIsInteger(p, &v) ) return 0; - return v!=0; -} -static int exprAlwaysFalse(Expr *p){ - int v = 0; - if( ExprHasProperty(p, EP_FromJoin) ) return 0; - if( !sqlite3ExprIsInteger(p, &v) ) return 0; - return v==0; -} - -/* -** Join two expressions using an AND operator. If either expression is -** NULL, then just return the other expression. -** -** If one side or the other of the AND is known to be false, then instead -** of returning an AND expression, just return a constant expression with -** a value of false. -*/ -Expr *sqlite3ExprAnd(sqlite3 *db, Expr *pLeft, Expr *pRight){ - if( pLeft==0 ){ - return pRight; - }else if( pRight==0 ){ - return pLeft; - }else if( exprAlwaysFalse(pLeft) || exprAlwaysFalse(pRight) ){ - sqlite3ExprDelete(db, pLeft); - sqlite3ExprDelete(db, pRight); - return sqlite3ExprAlloc(db, TK_INTEGER, &sqlite3IntTokens[0], 0); - }else{ - Expr *pNew = sqlite3ExprAlloc(db, TK_AND, 0, 0); - sqlite3ExprAttachSubtrees(db, pNew, pLeft, pRight); - return pNew; - } -} - -/* -** Construct a new expression node for a function with multiple -** arguments. -*/ -Expr *sqlite3ExprFunction(Parse *pParse, ExprList *pList, Token *pToken){ - Expr *pNew; - sqlite3 *db = pParse->db; - assert( pToken ); - pNew = sqlite3ExprAlloc(db, TK_FUNCTION, pToken, 1); - if( pNew==0 ){ - sqlite3ExprListDelete(db, pList); /* Avoid memory leak when malloc fails */ - return 0; - } - pNew->x.pList = pList; - assert( !ExprHasProperty(pNew, EP_xIsSelect) ); - sqlite3ExprSetHeightAndFlags(pParse, pNew); - return pNew; -} - -/* -** Assign a variable number to an expression that encodes a wildcard -** in the original SQL statement. -** -** Wildcards consisting of a single "?" are assigned the next sequential -** variable number. -** -** Wildcards of the form "?nnn" are assigned the number "nnn". We make -** sure "nnn" is not too be to avoid a denial of service attack when -** the SQL statement comes from an external source. -** -** Wildcards of the form ":aaa", "@aaa", or "$aaa" are assigned the same number -** as the previous instance of the same wildcard. Or if this is the first -** instance of the wildcard, the next sequential variable number is -** assigned. -*/ -void sqlite3ExprAssignVarNumber(Parse *pParse, Expr *pExpr){ - sqlite3 *db = pParse->db; - const char *z; - - if( pExpr==0 ) return; - assert( !ExprHasProperty(pExpr, EP_IntValue|EP_Reduced|EP_TokenOnly) ); - z = pExpr->u.zToken; - assert( z!=0 ); - assert( z[0]!=0 ); - if( z[1]==0 ){ - /* Wildcard of the form "?". Assign the next variable number */ - assert( z[0]=='?' ); - pExpr->iColumn = (ynVar)(++pParse->nVar); - }else{ - ynVar x = 0; - u32 n = sqlite3Strlen30(z); - if( z[0]=='?' ){ - /* Wildcard of the form "?nnn". Convert "nnn" to an integer and - ** use it as the variable number */ - i64 i; - int bOk = 0==sqlite3Atoi64(&z[1], &i, n-1, SQLITE_UTF8); - pExpr->iColumn = x = (ynVar)i; - testcase( i==0 ); - testcase( i==1 ); - testcase( i==db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER]-1 ); - testcase( i==db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER] ); - if( bOk==0 || i<1 || i>db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER] ){ - sqlite3ErrorMsg(pParse, "variable number must be between ?1 and ?%d", - db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER]); - x = 0; - } - if( i>pParse->nVar ){ - pParse->nVar = (int)i; - } - }else{ - /* Wildcards like ":aaa", "$aaa" or "@aaa". Reuse the same variable - ** number as the prior appearance of the same name, or if the name - ** has never appeared before, reuse the same variable number - */ - ynVar i; - for(i=0; i<pParse->nzVar; i++){ - if( pParse->azVar[i] && strcmp(pParse->azVar[i],z)==0 ){ - pExpr->iColumn = x = (ynVar)i+1; - break; - } - } - if( x==0 ) x = pExpr->iColumn = (ynVar)(++pParse->nVar); - } - if( x>0 ){ - if( x>pParse->nzVar ){ - char **a; - a = sqlite3DbRealloc(db, pParse->azVar, x*sizeof(a[0])); - if( a==0 ) return; /* Error reported through db->mallocFailed */ - pParse->azVar = a; - memset(&a[pParse->nzVar], 0, (x-pParse->nzVar)*sizeof(a[0])); - pParse->nzVar = x; - } - if( z[0]!='?' || pParse->azVar[x-1]==0 ){ - sqlite3DbFree(db, pParse->azVar[x-1]); - pParse->azVar[x-1] = sqlite3DbStrNDup(db, z, n); - } - } - } - if( !pParse->nErr && pParse->nVar>db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER] ){ - sqlite3ErrorMsg(pParse, "too many SQL variables"); - } -} - -/* -** Recursively delete an expression tree. -*/ -void sqlite3ExprDelete(sqlite3 *db, Expr *p){ - if( p==0 ) return; - /* Sanity check: Assert that the IntValue is non-negative if it exists */ - assert( !ExprHasProperty(p, EP_IntValue) || p->u.iValue>=0 ); - if( !ExprHasProperty(p, EP_TokenOnly) ){ - /* The Expr.x union is never used at the same time as Expr.pRight */ - assert( p->x.pList==0 || p->pRight==0 ); - sqlite3ExprDelete(db, p->pLeft); - sqlite3ExprDelete(db, p->pRight); - if( ExprHasProperty(p, EP_MemToken) ) sqlite3DbFree(db, p->u.zToken); - if( ExprHasProperty(p, EP_xIsSelect) ){ - sqlite3SelectDelete(db, p->x.pSelect); - }else{ - sqlite3ExprListDelete(db, p->x.pList); - } - } - if( !ExprHasProperty(p, EP_Static) ){ - sqlite3DbFree(db, p); - } -} - -/* -** Return the number of bytes allocated for the expression structure -** passed as the first argument. This is always one of EXPR_FULLSIZE, -** EXPR_REDUCEDSIZE or EXPR_TOKENONLYSIZE. -*/ -static int exprStructSize(Expr *p){ - if( ExprHasProperty(p, EP_TokenOnly) ) return EXPR_TOKENONLYSIZE; - if( ExprHasProperty(p, EP_Reduced) ) return EXPR_REDUCEDSIZE; - return EXPR_FULLSIZE; -} - -/* -** The dupedExpr*Size() routines each return the number of bytes required -** to store a copy of an expression or expression tree. They differ in -** how much of the tree is measured. -** -** dupedExprStructSize() Size of only the Expr structure -** dupedExprNodeSize() Size of Expr + space for token -** dupedExprSize() Expr + token + subtree components -** -*************************************************************************** -** -** The dupedExprStructSize() function returns two values OR-ed together: -** (1) the space required for a copy of the Expr structure only and -** (2) the EP_xxx flags that indicate what the structure size should be. -** The return values is always one of: -** -** EXPR_FULLSIZE -** EXPR_REDUCEDSIZE | EP_Reduced -** EXPR_TOKENONLYSIZE | EP_TokenOnly -** -** The size of the structure can be found by masking the return value -** of this routine with 0xfff. The flags can be found by masking the -** return value with EP_Reduced|EP_TokenOnly. -** -** Note that with flags==EXPRDUP_REDUCE, this routines works on full-size -** (unreduced) Expr objects as they or originally constructed by the parser. -** During expression analysis, extra information is computed and moved into -** later parts of teh Expr object and that extra information might get chopped -** off if the expression is reduced. Note also that it does not work to -** make 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&EXPRDUP_REDUCE) ){ - nSize = EXPR_FULLSIZE; - }else{ - assert( !ExprHasProperty(p, EP_TokenOnly|EP_Reduced) ); - assert( !ExprHasProperty(p, EP_FromJoin) ); - assert( !ExprHasProperty(p, EP_MemToken) ); - assert( !ExprHasProperty(p, EP_NoReduce) ); - if( p->pLeft || p->x.pList ){ - nSize = EXPR_REDUCEDSIZE | EP_Reduced; - }else{ - assert( p->pRight==0 ); - nSize = EXPR_TOKENONLYSIZE | EP_TokenOnly; - } - } - return nSize; -} - -/* -** This function returns the space in bytes required to store the copy -** of the Expr structure and a copy of the Expr.u.zToken string (if that -** string is defined.) -*/ -static int dupedExprNodeSize(Expr *p, int flags){ - int nByte = dupedExprStructSize(p, flags) & 0xfff; - if( !ExprHasProperty(p, EP_IntValue) && p->u.zToken ){ - nByte += sqlite3Strlen30(p->u.zToken)+1; - } - return ROUND8(nByte); -} - -/* -** Return the number of bytes required to create a duplicate of the -** expression passed as the first argument. The second argument is a -** mask containing EXPRDUP_XXX flags. -** -** The value returned includes space to create a copy of the Expr struct -** itself and the buffer referred to by Expr.u.zToken, if any. -** -** If the EXPRDUP_REDUCE flag is set, then the return value includes -** space to duplicate all Expr nodes in the tree formed by Expr.pLeft -** and Expr.pRight variables (but not for any structures pointed to or -** descended from the Expr.x.pList or Expr.x.pSelect variables). -*/ -static int dupedExprSize(Expr *p, int flags){ - int nByte = 0; - if( p ){ - nByte = dupedExprNodeSize(p, flags); - if( flags&EXPRDUP_REDUCE ){ - nByte += dupedExprSize(p->pLeft, flags) + dupedExprSize(p->pRight, flags); - } - } - return nByte; -} - -/* -** This function is similar to sqlite3ExprDup(), except that if pzBuffer -** is not NULL then *pzBuffer is assumed to point to a buffer large enough -** to store the copy of expression p, the copies of p->u.zToken -** (if applicable), and the copies of the p->pLeft and p->pRight expressions, -** if any. Before returning, *pzBuffer is set to the first byte past the -** portion of the buffer copied into by this function. -*/ -static Expr *exprDup(sqlite3 *db, Expr *p, int flags, u8 **pzBuffer){ - Expr *pNew = 0; /* Value to return */ - if( p ){ - const int isReduced = (flags&EXPRDUP_REDUCE); - u8 *zAlloc; - u32 staticFlag = 0; - - assert( pzBuffer==0 || isReduced ); - - /* Figure out where to write the new Expr structure. */ - if( pzBuffer ){ - zAlloc = *pzBuffer; - staticFlag = EP_Static; - }else{ - zAlloc = sqlite3DbMallocRaw(db, dupedExprSize(p, flags)); - } - pNew = (Expr *)zAlloc; - - if( pNew ){ - /* Set nNewSize to the size allocated for the structure pointed to - ** by pNew. This is either EXPR_FULLSIZE, EXPR_REDUCEDSIZE or - ** EXPR_TOKENONLYSIZE. nToken is set to the number of bytes consumed - ** by the copy of the p->u.zToken string (if any). - */ - const unsigned nStructSize = dupedExprStructSize(p, flags); - const int nNewSize = nStructSize & 0xfff; - int nToken; - if( !ExprHasProperty(p, EP_IntValue) && p->u.zToken ){ - nToken = sqlite3Strlen30(p->u.zToken) + 1; - }else{ - nToken = 0; - } - if( isReduced ){ - assert( ExprHasProperty(p, EP_Reduced)==0 ); - memcpy(zAlloc, p, nNewSize); - }else{ - int nSize = exprStructSize(p); - memcpy(zAlloc, p, nSize); - memset(&zAlloc[nSize], 0, EXPR_FULLSIZE-nSize); - } - - /* Set the EP_Reduced, EP_TokenOnly, and EP_Static flags appropriately. */ - pNew->flags &= ~(EP_Reduced|EP_TokenOnly|EP_Static|EP_MemToken); - pNew->flags |= nStructSize & (EP_Reduced|EP_TokenOnly); - pNew->flags |= staticFlag; - - /* Copy the p->u.zToken string, if any. */ - if( nToken ){ - char *zToken = pNew->u.zToken = (char*)&zAlloc[nNewSize]; - memcpy(zToken, p->u.zToken, nToken); - } - - if( 0==((p->flags|pNew->flags) & EP_TokenOnly) ){ - /* Fill in the pNew->x.pSelect or pNew->x.pList member. */ - if( ExprHasProperty(p, EP_xIsSelect) ){ - pNew->x.pSelect = sqlite3SelectDup(db, p->x.pSelect, isReduced); - }else{ - pNew->x.pList = sqlite3ExprListDup(db, p->x.pList, isReduced); - } - } - - /* Fill in pNew->pLeft and pNew->pRight. */ - if( ExprHasProperty(pNew, EP_Reduced|EP_TokenOnly) ){ - zAlloc += dupedExprNodeSize(p, flags); - if( ExprHasProperty(pNew, EP_Reduced) ){ - pNew->pLeft = exprDup(db, p->pLeft, EXPRDUP_REDUCE, &zAlloc); - pNew->pRight = exprDup(db, p->pRight, EXPRDUP_REDUCE, &zAlloc); - } - if( pzBuffer ){ - *pzBuffer = zAlloc; - } - }else{ - if( !ExprHasProperty(p, EP_TokenOnly) ){ - pNew->pLeft = sqlite3ExprDup(db, p->pLeft, 0); - pNew->pRight = sqlite3ExprDup(db, p->pRight, 0); - } - } - - } - } - return pNew; -} - -/* -** 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 ){ - int 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; i<p->nCte; 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 - -/* -** The following group of routines make deep copies of expressions, -** expression lists, ID lists, and select statements. The copies can -** be deleted (by being passed to their respective ...Delete() routines) -** without effecting the originals. -** -** The expression list, ID, and source lists return by sqlite3ExprListDup(), -** sqlite3IdListDup(), and sqlite3SrcListDup() can not be further expanded -** by subsequent calls to sqlite*ListAppend() routines. -** -** Any tables that the SrcList might point to are not duplicated. -** -** The flags parameter contains a combination of the EXPRDUP_XXX flags. -** If the EXPRDUP_REDUCE flag is set, then the structure returned is a -** truncated version of the usual Expr structure that will be stored as -** part of the in-memory representation of the database schema. -*/ -Expr *sqlite3ExprDup(sqlite3 *db, Expr *p, int flags){ - return exprDup(db, p, flags, 0); -} -ExprList *sqlite3ExprListDup(sqlite3 *db, ExprList *p, int flags){ - ExprList *pNew; - struct ExprList_item *pItem, *pOldItem; - int i; - if( p==0 ) return 0; - pNew = sqlite3DbMallocRaw(db, sizeof(*pNew) ); - if( pNew==0 ) return 0; - pNew->nExpr = i = p->nExpr; - if( (flags & EXPRDUP_REDUCE)==0 ) for(i=1; i<p->nExpr; i+=i){} - pNew->a = pItem = sqlite3DbMallocRaw(db, i*sizeof(p->a[0]) ); - if( pItem==0 ){ - sqlite3DbFree(db, pNew); - return 0; - } - pOldItem = p->a; - for(i=0; i<p->nExpr; i++, pItem++, pOldItem++){ - Expr *pOldExpr = pOldItem->pExpr; - pItem->pExpr = sqlite3ExprDup(db, pOldExpr, flags); - pItem->zName = sqlite3DbStrDup(db, pOldItem->zName); - pItem->zSpan = sqlite3DbStrDup(db, pOldItem->zSpan); - pItem->sortOrder = pOldItem->sortOrder; - pItem->done = 0; - pItem->bSpanIsTab = pOldItem->bSpanIsTab; - pItem->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; - if( p==0 ) return 0; - nByte = sizeof(*p) + (p->nSrc>0 ? sizeof(p->a[0]) * (p->nSrc-1) : 0); - pNew = sqlite3DbMallocRaw(db, nByte ); - if( pNew==0 ) return 0; - pNew->nSrc = pNew->nAlloc = p->nSrc; - for(i=0; i<p->nSrc; i++){ - struct SrcList_item *pNewItem = &pNew->a[i]; - struct SrcList_item *pOldItem = &p->a[i]; - Table *pTab; - pNewItem->pSchema = pOldItem->pSchema; - pNewItem->zDatabase = sqlite3DbStrDup(db, pOldItem->zDatabase); - pNewItem->zName = sqlite3DbStrDup(db, pOldItem->zName); - pNewItem->zAlias = sqlite3DbStrDup(db, pOldItem->zAlias); - pNewItem->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->nRef++; - } - pNewItem->pSelect = sqlite3SelectDup(db, pOldItem->pSelect, flags); - pNewItem->pOn = sqlite3ExprDup(db, pOldItem->pOn, flags); - pNewItem->pUsing = sqlite3IdListDup(db, pOldItem->pUsing); - pNewItem->colUsed = pOldItem->colUsed; - } - return pNew; -} -IdList *sqlite3IdListDup(sqlite3 *db, IdList *p){ - IdList *pNew; - int i; - if( p==0 ) return 0; - pNew = sqlite3DbMallocRaw(db, sizeof(*pNew) ); - if( pNew==0 ) return 0; - pNew->nId = p->nId; - pNew->a = sqlite3DbMallocRaw(db, p->nId*sizeof(p->a[0]) ); - if( pNew->a==0 ){ - sqlite3DbFree(db, pNew); - return 0; - } - /* Note that because the size of the allocation for p->a[] is not - ** necessarily a power of two, sqlite3IdListAppend() may not be called - ** on the duplicate created by this function. */ - for(i=0; i<p->nId; i++){ - struct IdList_item *pNewItem = &pNew->a[i]; - struct IdList_item *pOldItem = &p->a[i]; - pNewItem->zName = sqlite3DbStrDup(db, pOldItem->zName); - pNewItem->idx = pOldItem->idx; - } - return pNew; -} -Select *sqlite3SelectDup(sqlite3 *db, Select *p, int flags){ - Select *pNew, *pPrior; - if( p==0 ) return 0; - pNew = sqlite3DbMallocRaw(db, sizeof(*p) ); - if( pNew==0 ) return 0; - pNew->pEList = sqlite3ExprListDup(db, p->pEList, flags); - pNew->pSrc = sqlite3SrcListDup(db, p->pSrc, flags); - pNew->pWhere = sqlite3ExprDup(db, p->pWhere, flags); - pNew->pGroupBy = sqlite3ExprListDup(db, p->pGroupBy, flags); - pNew->pHaving = sqlite3ExprDup(db, p->pHaving, flags); - pNew->pOrderBy = sqlite3ExprListDup(db, p->pOrderBy, flags); - pNew->op = p->op; - pNew->pPrior = pPrior = sqlite3SelectDup(db, p->pPrior, flags); - if( pPrior ) pPrior->pNext = pNew; - pNew->pNext = 0; - pNew->pLimit = sqlite3ExprDup(db, p->pLimit, flags); - pNew->pOffset = sqlite3ExprDup(db, p->pOffset, flags); - pNew->iLimit = 0; - pNew->iOffset = 0; - pNew->selFlags = p->selFlags & ~SF_UsesEphemeral; - pNew->addrOpenEphm[0] = -1; - pNew->addrOpenEphm[1] = -1; - pNew->nSelectRow = p->nSelectRow; - pNew->pWith = withDup(db, p->pWith); - sqlite3SelectSetName(pNew, p->zSelName); - return pNew; -} -#else -Select *sqlite3SelectDup(sqlite3 *db, Select *p, int flags){ - assert( p==0 ); - return 0; -} -#endif - - -/* -** Add a new element to the end of an expression list. If pList is -** initially NULL, then create a new expression list. -** -** If a memory allocation error occurs, the entire list is freed and -** NULL is returned. If non-NULL is returned, then it is guaranteed -** that the new entry was successfully appended. -*/ -ExprList *sqlite3ExprListAppend( - Parse *pParse, /* Parsing context */ - ExprList *pList, /* List to which to append. Might be NULL */ - Expr *pExpr /* Expression to be appended. Might be NULL */ -){ - sqlite3 *db = pParse->db; - if( pList==0 ){ - pList = sqlite3DbMallocZero(db, sizeof(ExprList) ); - if( pList==0 ){ - goto no_mem; - } - pList->a = sqlite3DbMallocRaw(db, sizeof(pList->a[0])); - if( pList->a==0 ) goto no_mem; - }else if( (pList->nExpr & (pList->nExpr-1))==0 ){ - struct ExprList_item *a; - assert( pList->nExpr>0 ); - a = sqlite3DbRealloc(db, pList->a, pList->nExpr*2*sizeof(pList->a[0])); - if( a==0 ){ - goto no_mem; - } - pList->a = a; - } - assert( pList->a!=0 ); - if( 1 ){ - struct ExprList_item *pItem = &pList->a[pList->nExpr++]; - memset(pItem, 0, sizeof(*pItem)); - pItem->pExpr = pExpr; - } - return pList; - -no_mem: - /* Avoid leaking memory if malloc has failed. */ - sqlite3ExprDelete(db, pExpr); - sqlite3ExprListDelete(db, pList); - return 0; -} - -/* -** Set the 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 && pItem->zName ) sqlite3Dequote(pItem->zName); - } -} - -/* -** Set the ExprList.a[].zSpan element of the most recently added item -** on the expression list. -** -** pList might be NULL following an OOM error. But pSpan should never be -** NULL. If a memory allocation fails, the pParse->db->mallocFailed flag -** is set. -*/ -void sqlite3ExprListSetSpan( - Parse *pParse, /* Parsing context */ - ExprList *pList, /* List to which to add the span. */ - ExprSpan *pSpan /* The span to be added */ -){ - sqlite3 *db = pParse->db; - assert( pList!=0 || db->mallocFailed!=0 ); - if( pList ){ - struct ExprList_item *pItem = &pList->a[pList->nExpr-1]; - assert( pList->nExpr>0 ); - assert( db->mallocFailed || pItem->pExpr==pSpan->pExpr ); - sqlite3DbFree(db, pItem->zSpan); - pItem->zSpan = sqlite3DbStrNDup(db, (char*)pSpan->zStart, - (int)(pSpan->zEnd - pSpan->zStart)); - } -} - -/* -** If the expression list pEList contains more than iLimit elements, -** leave an error message in pParse. -*/ -void sqlite3ExprListCheckLength( - Parse *pParse, - ExprList *pEList, - const char *zObject -){ - int mx = pParse->db->aLimit[SQLITE_LIMIT_COLUMN]; - testcase( pEList && pEList->nExpr==mx ); - testcase( pEList && pEList->nExpr==mx+1 ); - if( pEList && pEList->nExpr>mx ){ - sqlite3ErrorMsg(pParse, "too many columns in %s", zObject); - } -} - -/* -** Delete an entire expression list. -*/ -void sqlite3ExprListDelete(sqlite3 *db, ExprList *pList){ - int i; - struct ExprList_item *pItem; - if( pList==0 ) return; - assert( pList->a!=0 || pList->nExpr==0 ); - for(pItem=pList->a, i=0; i<pList->nExpr; i++, pItem++){ - sqlite3ExprDelete(db, pItem->pExpr); - sqlite3DbFree(db, pItem->zName); - sqlite3DbFree(db, pItem->zSpan); - } - sqlite3DbFree(db, pList->a); - sqlite3DbFree(db, pList); -} - -/* -** Return the bitwise-OR of all Expr.flags fields in the given -** ExprList. -*/ -u32 sqlite3ExprListFlags(const ExprList *pList){ - int i; - u32 m = 0; - if( pList ){ - for(i=0; i<pList->nExpr; i++){ - Expr *pExpr = pList->a[i].pExpr; - if( ALWAYS(pExpr) ) m |= pExpr->flags; - } - } - return m; -} - -/* -** 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: - 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( pWalker->eCode==3 && pExpr->iTable==pWalker->u.iCur ){ - return WRC_Continue; - }else{ - 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 ); /* selectNodeIsConstant will disallow */ - testcase( pExpr->op==TK_EXISTS ); /* selectNodeIsConstant will disallow */ - return WRC_Continue; - } -} -static int selectNodeIsConstant(Walker *pWalker, Select *NotUsed){ - UNUSED_PARAMETER(NotUsed); - pWalker->eCode = 0; - return WRC_Abort; -} -static int exprIsConst(Expr *p, int initFlag, int iCur){ - Walker w; - memset(&w, 0, sizeof(w)); - w.eCode = initFlag; - w.xExprCallback = exprNodeIsConstant; - w.xSelectCallback = selectNodeIsConstant; - 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 the expression is constant -** that does no originate from the ON or USING clauses of a join. -** Return 0 if it involves variables or function calls or terms from -** an ON or USING clause. -*/ -int sqlite3ExprIsConstantNotJoin(Expr *p){ - return exprIsConst(p, 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); -} - -/* -** 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); -} - -/* -** If the expression p codes a constant integer that is small enough -** to fit in a 32-bit integer, return 1 and put the value of the integer -** in *pValue. If the expression is not an integer or if it is too big -** to fit in a signed 32-bit integer, return 0 and leave *pValue unchanged. -*/ -int sqlite3ExprIsInteger(Expr *p, int *pValue){ - int rc = 0; - - /* If an expression is an integer literal that fits in a signed 32-bit - ** integer, then the EP_IntValue flag will have already been set */ - assert( p->op!=TK_INTEGER || (p->flags & EP_IntValue)!=0 - || sqlite3GetInt32(p->u.zToken, &rc)==0 ); - - if( p->flags & EP_IntValue ){ - *pValue = p->u.iValue; - return 1; - } - switch( p->op ){ - case TK_UPLUS: { - rc = sqlite3ExprIsInteger(p->pLeft, pValue); - break; - } - case TK_UMINUS: { - int v; - if( sqlite3ExprIsInteger(p->pLeft, &v) ){ - assert( v!=(-2147483647-1) ); - *pValue = -v; - rc = 1; - } - break; - } - default: break; - } - return rc; -} - -/* -** Return FALSE if there is no chance that the expression can be NULL. -** -** If the expression might be NULL or if the expression is too complex -** to tell return TRUE. -** -** This routine is used as an optimization, to skip OP_IsNull opcodes -** when we know that a value cannot be NULL. Hence, a false positive -** (returning TRUE when in fact the expression can never be NULL) might -** be a small performance hit but is otherwise harmless. On the other -** hand, a false negative (returning FALSE when the result could be NULL) -** will likely result in an incorrect answer. So when in doubt, return -** TRUE. -*/ -int sqlite3ExprCanBeNull(const Expr *p){ - u8 op; - while( p->op==TK_UPLUS || p->op==TK_UMINUS ){ p = p->pLeft; } - op = p->op; - if( op==TK_REGISTER ) op = p->op2; - switch( op ){ - case TK_INTEGER: - case TK_STRING: - case TK_FLOAT: - case TK_BLOB: - return 0; - case TK_COLUMN: - assert( p->pTab!=0 ); - return ExprHasProperty(p, EP_CanBeNull) || - (p->iColumn>=0 && p->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; -} - -/* -** Return true if we are able to the IN operator optimization on a -** query of the form -** -** x IN (SELECT ...) -** -** Where the SELECT... clause is as specified by the parameter to this -** routine. -** -** The Select object passed in has already been preprocessed and no -** errors have been found. -*/ -#ifndef SQLITE_OMIT_SUBQUERY -static int isCandidateForInOpt(Select *p){ - SrcList *pSrc; - ExprList *pEList; - Table *pTab; - if( p==0 ) return 0; /* right-hand side of IN is SELECT */ - if( p->pPrior ) return 0; /* Not a compound SELECT */ - if( p->selFlags & (SF_Distinct|SF_Aggregate) ){ - testcase( (p->selFlags & (SF_Distinct|SF_Aggregate))==SF_Distinct ); - testcase( (p->selFlags & (SF_Distinct|SF_Aggregate))==SF_Aggregate ); - return 0; /* No DISTINCT keyword and no aggregate functions */ - } - assert( p->pGroupBy==0 ); /* Has no GROUP BY clause */ - if( p->pLimit ) return 0; /* Has no LIMIT clause */ - assert( p->pOffset==0 ); /* No LIMIT means no OFFSET */ - if( p->pWhere ) return 0; /* Has no WHERE clause */ - pSrc = p->pSrc; - assert( pSrc!=0 ); - if( pSrc->nSrc!=1 ) return 0; /* Single term in FROM clause */ - if( pSrc->a[0].pSelect ) return 0; /* FROM is not a subquery or view */ - pTab = pSrc->a[0].pTab; - if( NEVER(pTab==0) ) return 0; - assert( pTab->pSelect==0 ); /* FROM clause is not a view */ - if( IsVirtual(pTab) ) return 0; /* FROM clause not a virtual table */ - pEList = p->pEList; - if( pEList->nExpr!=1 ) return 0; /* One column in the result set */ - if( pEList->a[0].pExpr->op!=TK_COLUMN ) return 0; /* Result is a column */ - return 1; -} -#endif /* SQLITE_OMIT_SUBQUERY */ - -/* -** Code an OP_Once instruction and allocate space for its flag. Return the -** address of the new instruction. -*/ -int sqlite3CodeOnce(Parse *pParse){ - Vdbe *v = sqlite3GetVdbe(pParse); /* Virtual machine being coded */ - return sqlite3VdbeAddOp1(v, OP_Once, pParse->nOnce++); -} - -/* -** 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); -} - - -#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 <column> FROM <table> -** -** If the RHS of the IN operator is a list or a more complex subquery, then -** an ephemeral table might need to be generated from the RHS and then -** pX->iTable made to point to the ephemeral table instead of an -** existing table. -** -** The inFlags parameter must contain exactly one of the bits -** IN_INDEX_MEMBERSHIP or IN_INDEX_LOOP. 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 must be used unless the selected <column> is guaranteed -** to be unique - either because it is an INTEGER PRIMARY KEY or it -** has a UNIQUE constraint or UNIQUE index. -** -** 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 <column> is an INTEGER PRIMARY KEY or an index can -** be found with <column> as its left-most column. -** -** 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. -*/ -#ifndef SQLITE_OMIT_SUBQUERY -int sqlite3FindInIndex(Parse *pParse, Expr *pX, u32 inFlags, int *prRhsHasNull){ - 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; - - /* Check to see if an existing table or index can be used to - ** satisfy the query. This is preferable to generating a new - ** ephemeral table. - */ - p = (ExprHasProperty(pX, EP_xIsSelect) ? pX->x.pSelect : 0); - if( pParse->nErr==0 && isCandidateForInOpt(p) ){ - sqlite3 *db = pParse->db; /* Database connection */ - Table *pTab; /* Table <table>. */ - Expr *pExpr; /* Expression <column> */ - i16 iCol; /* Index of column <column> */ - i16 iDb; /* Database idx for pTab */ - - assert( p ); /* Because of isCandidateForInOpt(p) */ - assert( p->pEList!=0 ); /* Because of isCandidateForInOpt(p) */ - assert( p->pEList->a[0].pExpr!=0 ); /* Because of isCandidateForInOpt(p) */ - assert( p->pSrc!=0 ); /* Because of isCandidateForInOpt(p) */ - pTab = p->pSrc->a[0].pTab; - pExpr = p->pEList->a[0].pExpr; - iCol = (i16)pExpr->iColumn; - - /* Code an OP_Transaction and OP_TableLock for <table>. */ - iDb = sqlite3SchemaToIndex(db, pTab->pSchema); - sqlite3CodeVerifySchema(pParse, iDb); - sqlite3TableLock(pParse, iDb, pTab->tnum, 0, pTab->zName); - - /* This function is only called from two places. In both cases the vdbe - ** has already been allocated. So assume sqlite3GetVdbe() is always - ** successful here. - */ - assert(v); - if( iCol<0 ){ - int iAddr = sqlite3CodeOnce(pParse); - VdbeCoverage(v); - - sqlite3OpenTable(pParse, iTab, iDb, pTab, OP_OpenRead); - eType = IN_INDEX_ROWID; - - sqlite3VdbeJumpHere(v, iAddr); - }else{ - Index *pIdx; /* Iterator variable */ - - /* The collation sequence used by the comparison. If an index is to - ** be used in place of a temp-table, it must be ordered according - ** to this collation sequence. */ - CollSeq *pReq = sqlite3BinaryCompareCollSeq(pParse, pX->pLeft, pExpr); - - /* Check that the affinity that will be used to perform the - ** comparison is the same as the affinity of the column. If - ** it is not, it is not possible to use any index. - */ - int affinity_ok = sqlite3IndexAffinityOk(pX, pTab->aCol[iCol].affinity); - - for(pIdx=pTab->pIndex; pIdx && eType==0 && affinity_ok; pIdx=pIdx->pNext){ - if( (pIdx->aiColumn[0]==iCol) - && sqlite3FindCollSeq(db, ENC(db), pIdx->azColl[0], 0)==pReq - && (!mustBeUnique || (pIdx->nKeyCol==1 && IsUniqueIndex(pIdx))) - ){ - int iAddr = sqlite3CodeOnce(pParse); VdbeCoverage(v); - 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 && !pTab->aCol[iCol].notNull ){ - *prRhsHasNull = ++pParse->nMem; - sqlite3SetHasNullFlag(v, iTab, *prRhsHasNull); - } - sqlite3VdbeJumpHere(v, iAddr); - } - } - } - } - - /* 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 contant 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; - if( pX->pLeft->iColumn<0 && !ExprHasProperty(pX, EP_xIsSelect) ){ - eType = IN_INDEX_ROWID; - } - }else if( prRhsHasNull ){ - *prRhsHasNull = rMayHaveNull = ++pParse->nMem; - } - sqlite3CodeSubselect(pParse, pX, rMayHaveNull, eType==IN_INDEX_ROWID); - pParse->nQueryLoop = savedNQueryLoop; - }else{ - pX->iTable = iTab; - } - return eType; -} -#endif - -/* -** Generate code for scalar subqueries used as a subquery expression, EXISTS, -** or IN operators. Examples: -** -** (SELECT a FROM b) -- subquery -** EXISTS (SELECT a FROM b) -- EXISTS subquery -** x IN (4,5,11) -- IN operator with list on right-hand side -** x IN (SELECT a FROM b) -- IN operator with subquery on the right -** -** The pExpr parameter describes the expression that contains the IN -** operator or subquery. -** -** If parameter isRowid is non-zero, then expression pExpr is guaranteed -** to be of the form "<rowid> IN (?, ?, ?)", where <rowid> is a reference -** to some integer key column of a table B-Tree. In this case, use an -** intkey B-Tree to store the set of IN(...) values instead of the usual -** (slower) variable length keys B-Tree. -** -** If rMayHaveNull is non-zero, that means that the operation is an IN -** (not a SELECT or EXISTS) and that the RHS might contains NULLs. -** All this routine does is initialize the register given by rMayHaveNull -** to NULL. Calling routines will take care of changing this register -** value to non-NULL if the RHS is NULL-free. -** -** For a SELECT or EXISTS operator, return the register that holds the -** result. For IN operators or if an error occurs, the return value is 0. -*/ -#ifndef SQLITE_OMIT_SUBQUERY -int sqlite3CodeSubselect( - Parse *pParse, /* Parsing context */ - Expr *pExpr, /* The IN, SELECT, or EXISTS operator */ - int rHasNullFlag, /* Register that records whether NULLs exist in RHS */ - int isRowid /* If true, LHS of IN operator is a rowid */ -){ - int jmpIfDynamic = -1; /* One-time test address */ - int rReg = 0; /* Register storing resulting */ - Vdbe *v = sqlite3GetVdbe(pParse); - if( NEVER(v==0) ) return 0; - sqlite3ExprCachePush(pParse); - - /* This code must be run in its entirety every time it is encountered - ** if any of the following is true: - ** - ** * The right-hand side is a correlated subquery - ** * The right-hand side is an expression list containing variables - ** * We are inside a trigger - ** - ** If all of the above are false, then we can run this code just once - ** save the results, and reuse the same result on subsequent invocations. - */ - if( !ExprHasProperty(pExpr, EP_VarSelect) ){ - jmpIfDynamic = sqlite3CodeOnce(pParse); VdbeCoverage(v); - } - -#ifndef SQLITE_OMIT_EXPLAIN - if( pParse->explain==2 ){ - char *zMsg = sqlite3MPrintf( - pParse->db, "EXECUTE %s%s SUBQUERY %d", jmpIfDynamic>=0?"":"CORRELATED ", - pExpr->op==TK_IN?"LIST":"SCALAR", pParse->iNextSelectId - ); - sqlite3VdbeAddOp4(v, OP_Explain, pParse->iSelectId, 0, 0, zMsg, P4_DYNAMIC); - } -#endif - - switch( pExpr->op ){ - case TK_IN: { - char affinity; /* Affinity of the LHS of the IN */ - int addr; /* Address of OP_OpenEphemeral instruction */ - Expr *pLeft = pExpr->pLeft; /* the LHS of the IN operator */ - KeyInfo *pKeyInfo = 0; /* Key information */ - - affinity = sqlite3ExprAffinity(pLeft); - - /* Whether this is an 'x IN(SELECT...)' or an 'x IN(<exprlist>)' - ** expression it is handled the same way. An ephemeral table is - ** filled with single-field index keys representing the results - ** from the SELECT or the <exprlist>. - ** - ** If the 'x' expression is a column value, or the SELECT... - ** statement returns a column value, then the affinity of that - ** column is used to build the index keys. If both 'x' and the - ** SELECT... statement are columns, then numeric affinity is used - ** if either column has NUMERIC or INTEGER affinity. If neither - ** 'x' nor the SELECT... statement are columns, then numeric affinity - ** is used. - */ - pExpr->iTable = pParse->nTab++; - addr = sqlite3VdbeAddOp2(v, OP_OpenEphemeral, pExpr->iTable, !isRowid); - pKeyInfo = isRowid ? 0 : sqlite3KeyInfoAlloc(pParse->db, 1, 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; - SelectDest dest; - ExprList *pEList; - - assert( !isRowid ); - sqlite3SelectDestInit(&dest, SRT_Set, pExpr->iTable); - dest.affSdst = (u8)affinity; - assert( (pExpr->iTable&0x0000FFFF)==pExpr->iTable ); - pSelect->iLimit = 0; - testcase( pSelect->selFlags & SF_Distinct ); - testcase( pKeyInfo==0 ); /* Caused by OOM in sqlite3KeyInfoAlloc() */ - if( sqlite3Select(pParse, pSelect, &dest) ){ - sqlite3KeyInfoUnref(pKeyInfo); - return 0; - } - pEList = pSelect->pEList; - assert( pKeyInfo!=0 ); /* OOM will cause exit after sqlite3Select() */ - assert( pEList!=0 ); - assert( pEList->nExpr>0 ); - assert( sqlite3KeyInfoIsWriteable(pKeyInfo) ); - pKeyInfo->aColl[0] = sqlite3BinaryCompareCollSeq(pParse, pExpr->pLeft, - pEList->a[0].pExpr); - }else if( ALWAYS(pExpr->x.pList!=0) ){ - /* Case 2: expr IN (exprlist) - ** - ** For each expression, build an index key from the evaluation and - ** store it in the temporary table. If <expr> is a column, then use - ** that columns affinity when building index keys. If <expr> is not - ** a column, use numeric affinity. - */ - int i; - ExprList *pList = pExpr->x.pList; - struct ExprList_item *pItem; - int r1, r2, r3; - - if( !affinity ){ - affinity = SQLITE_AFF_BLOB; - } - if( pKeyInfo ){ - assert( sqlite3KeyInfoIsWriteable(pKeyInfo) ); - pKeyInfo->aColl[0] = sqlite3ExprCollSeq(pParse, pExpr->pLeft); - } - - /* Loop through each expression in <exprlist>. */ - r1 = sqlite3GetTempReg(pParse); - r2 = sqlite3GetTempReg(pParse); - if( isRowid ) sqlite3VdbeAddOp2(v, OP_Null, 0, r2); - for(i=pList->nExpr, pItem=pList->a; i>0; i--, pItem++){ - Expr *pE2 = pItem->pExpr; - int iValToIns; - - /* If the expression is not constant then we will need to - ** disable the test that was generated above that makes sure - ** this code only executes once. Because for a non-constant - ** expression we need to rerun this code each time. - */ - if( jmpIfDynamic>=0 && !sqlite3ExprIsConstant(pE2) ){ - sqlite3VdbeChangeToNoop(v, jmpIfDynamic); - jmpIfDynamic = -1; - } - - /* Evaluate the expression and insert it into the temp table */ - if( isRowid && sqlite3ExprIsInteger(pE2, &iValToIns) ){ - sqlite3VdbeAddOp3(v, OP_InsertInt, pExpr->iTable, r2, iValToIns); - }else{ - r3 = sqlite3ExprCodeTarget(pParse, pE2, r1); - if( isRowid ){ - sqlite3VdbeAddOp2(v, OP_MustBeInt, r3, - sqlite3VdbeCurrentAddr(v)+2); - VdbeCoverage(v); - sqlite3VdbeAddOp3(v, OP_Insert, pExpr->iTable, r2, r3); - }else{ - sqlite3VdbeAddOp4(v, OP_MakeRecord, r3, 1, r2, &affinity, 1); - sqlite3ExprCacheAffinityChange(pParse, r3, 1); - sqlite3VdbeAddOp2(v, OP_IdxInsert, pExpr->iTable, r2); - } - } - } - sqlite3ReleaseTempReg(pParse, r1); - sqlite3ReleaseTempReg(pParse, r2); - } - if( pKeyInfo ){ - sqlite3VdbeChangeP4(v, addr, (void *)pKeyInfo, P4_KEYINFO); - } - break; - } - - case TK_EXISTS: - case TK_SELECT: - default: { - /* If this has to be a scalar SELECT. Generate code to put the - ** value of this select in a memory cell and record the number - ** of the memory cell in iColumn. If this is an EXISTS, write - ** an integer 0 (not exists) or 1 (exists) into a memory cell - ** and record that memory cell in iColumn. - */ - Select *pSel; /* SELECT statement to encode */ - SelectDest dest; /* How to deal with SELECt result */ - - testcase( pExpr->op==TK_EXISTS ); - testcase( pExpr->op==TK_SELECT ); - assert( pExpr->op==TK_EXISTS || pExpr->op==TK_SELECT ); - - assert( ExprHasProperty(pExpr, EP_xIsSelect) ); - pSel = pExpr->x.pSelect; - sqlite3SelectDestInit(&dest, 0, ++pParse->nMem); - if( pExpr->op==TK_SELECT ){ - dest.eDest = SRT_Mem; - dest.iSdst = dest.iSDParm; - sqlite3VdbeAddOp2(v, OP_Null, 0, dest.iSDParm); - VdbeComment((v, "Init subquery result")); - }else{ - dest.eDest = SRT_Exists; - sqlite3VdbeAddOp2(v, OP_Integer, 0, dest.iSDParm); - VdbeComment((v, "Init EXISTS result")); - } - sqlite3ExprDelete(pParse->db, pSel->pLimit); - pSel->pLimit = sqlite3PExpr(pParse, TK_INTEGER, 0, 0, - &sqlite3IntTokens[1]); - pSel->iLimit = 0; - pSel->selFlags &= ~SF_MultiValue; - if( sqlite3Select(pParse, pSel, &dest) ){ - return 0; - } - rReg = dest.iSDParm; - ExprSetVVAProperty(pExpr, EP_NoReduce); - break; - } - } - - if( rHasNullFlag ){ - sqlite3SetHasNullFlag(v, pExpr->iTable, rHasNullFlag); - } - - if( jmpIfDynamic>=0 ){ - sqlite3VdbeJumpHere(v, jmpIfDynamic); - } - sqlite3ExprCachePop(pParse); - - return rReg; -} -#endif /* SQLITE_OMIT_SUBQUERY */ - -#ifndef SQLITE_OMIT_SUBQUERY -/* -** Generate code for an IN expression. -** -** x IN (SELECT ...) -** x IN (value, value, ...) -** -** The left-hand side (LHS) is a scalar expression. The right-hand side (RHS) -** is an array of zero or more values. The expression is true if the LHS is -** contained within the RHS. The value of the expression is unknown (NULL) -** if the LHS is NULL or if the LHS is not contained within the RHS and the -** RHS contains one or more NULL values. -** -** This routine generates code 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. -*/ -static void sqlite3ExprCodeIN( - Parse *pParse, /* Parsing and code generating context */ - Expr *pExpr, /* The IN expression */ - int destIfFalse, /* Jump here if LHS is not contained in the RHS */ - int destIfNull /* Jump here if the results are unknown due to NULLs */ -){ - int rRhsHasNull = 0; /* Register that is true if RHS contains NULL values */ - char affinity; /* Comparison affinity to use */ - int eType; /* Type of the RHS */ - int r1; /* Temporary use register */ - Vdbe *v; /* Statement under construction */ - - /* Compute the RHS. After this step, the table with cursor - ** pExpr->iTable will contains the values that make up the RHS. - */ - v = pParse->pVdbe; - assert( v!=0 ); /* OOM detected prior to this routine */ - VdbeNoopComment((v, "begin IN expr")); - eType = sqlite3FindInIndex(pParse, pExpr, - IN_INDEX_MEMBERSHIP | IN_INDEX_NOOP_OK, - destIfFalse==destIfNull ? 0 : &rRhsHasNull); - - /* Figure out the affinity to use to create a key from the results - ** of the expression. affinityStr stores a static string suitable for - ** P4 of OP_MakeRecord. - */ - affinity = comparisonAffinity(pExpr); - - /* Code the LHS, the <expr> from "<expr> IN (...)". - */ - sqlite3ExprCachePush(pParse); - r1 = sqlite3GetTempReg(pParse); - sqlite3ExprCode(pParse, pExpr->pLeft, r1); - - /* If sqlite3FindInIndex() did not find or create an index that is - ** suitable for evaluating the IN operator, then evaluate using a - ** sequence of comparisons. - */ - if( eType==IN_INDEX_NOOP ){ - ExprList *pList = pExpr->x.pList; - CollSeq *pColl = sqlite3ExprCollSeq(pParse, pExpr->pLeft); - int labelOk = sqlite3VdbeMakeLabel(v); - int r2, regToFree; - int regCkNull = 0; - int ii; - assert( !ExprHasProperty(pExpr, EP_xIsSelect) ); - if( destIfNull!=destIfFalse ){ - regCkNull = sqlite3GetTempReg(pParse); - sqlite3VdbeAddOp3(v, OP_BitAnd, r1, r1, regCkNull); - } - for(ii=0; ii<pList->nExpr; ii++){ - r2 = sqlite3ExprCodeTemp(pParse, pList->a[ii].pExpr, ®ToFree); - if( regCkNull && sqlite3ExprCanBeNull(pList->a[ii].pExpr) ){ - sqlite3VdbeAddOp3(v, OP_BitAnd, regCkNull, r2, regCkNull); - } - if( ii<pList->nExpr-1 || destIfNull!=destIfFalse ){ - sqlite3VdbeAddOp4(v, OP_Eq, r1, labelOk, r2, - (void*)pColl, P4_COLLSEQ); - VdbeCoverageIf(v, ii<pList->nExpr-1); - VdbeCoverageIf(v, ii==pList->nExpr-1); - sqlite3VdbeChangeP5(v, affinity); - }else{ - assert( destIfNull==destIfFalse ); - sqlite3VdbeAddOp4(v, OP_Ne, r1, destIfFalse, r2, - (void*)pColl, P4_COLLSEQ); VdbeCoverage(v); - sqlite3VdbeChangeP5(v, affinity | SQLITE_JUMPIFNULL); - } - sqlite3ReleaseTempReg(pParse, regToFree); - } - if( regCkNull ){ - sqlite3VdbeAddOp2(v, OP_IsNull, regCkNull, destIfNull); VdbeCoverage(v); - sqlite3VdbeGoto(v, destIfFalse); - } - sqlite3VdbeResolveLabel(v, labelOk); - sqlite3ReleaseTempReg(pParse, regCkNull); - }else{ - - /* If the LHS is NULL, then the result is either false or NULL depending - ** on whether the RHS is empty or not, respectively. - */ - if( sqlite3ExprCanBeNull(pExpr->pLeft) ){ - if( destIfNull==destIfFalse ){ - /* Shortcut for the common case where the false and NULL outcomes are - ** the same. */ - sqlite3VdbeAddOp2(v, OP_IsNull, r1, destIfNull); VdbeCoverage(v); - }else{ - int addr1 = sqlite3VdbeAddOp1(v, OP_NotNull, r1); VdbeCoverage(v); - sqlite3VdbeAddOp2(v, OP_Rewind, pExpr->iTable, destIfFalse); - VdbeCoverage(v); - sqlite3VdbeGoto(v, destIfNull); - sqlite3VdbeJumpHere(v, addr1); - } - } - - if( eType==IN_INDEX_ROWID ){ - /* In this case, the RHS is the ROWID of table b-tree - */ - sqlite3VdbeAddOp2(v, OP_MustBeInt, r1, destIfFalse); VdbeCoverage(v); - sqlite3VdbeAddOp3(v, OP_NotExists, pExpr->iTable, destIfFalse, r1); - VdbeCoverage(v); - }else{ - /* In this case, the RHS is an index b-tree. - */ - sqlite3VdbeAddOp4(v, OP_Affinity, r1, 1, 0, &affinity, 1); - - /* If the set membership test fails, then the result of the - ** "x IN (...)" expression must be either 0 or NULL. If the set - ** contains no NULL values, then the result is 0. If the set - ** contains one or more NULL values, then the result of the - ** expression is also NULL. - */ - assert( destIfFalse!=destIfNull || rRhsHasNull==0 ); - if( rRhsHasNull==0 ){ - /* This branch runs if it is known at compile time that the RHS - ** cannot contain NULL values. This happens as the result - ** of a "NOT NULL" constraint in the database schema. - ** - ** Also run this branch if NULL is equivalent to FALSE - ** for this particular IN operator. - */ - sqlite3VdbeAddOp4Int(v, OP_NotFound, pExpr->iTable, destIfFalse, r1, 1); - VdbeCoverage(v); - }else{ - /* In this branch, the RHS of the IN might contain a NULL and - ** the presence of a NULL on the RHS makes a difference in the - ** outcome. - */ - int addr1; - - /* First check to see if the LHS is contained in the RHS. If so, - ** then the answer is TRUE the presence of NULLs in the RHS does - ** not matter. If the LHS is not contained in the RHS, then the - ** answer is NULL if the RHS contains NULLs and the answer is - ** FALSE if the RHS is NULL-free. - */ - addr1 = sqlite3VdbeAddOp4Int(v, OP_Found, pExpr->iTable, 0, r1, 1); - VdbeCoverage(v); - sqlite3VdbeAddOp2(v, OP_IsNull, rRhsHasNull, destIfNull); - VdbeCoverage(v); - sqlite3VdbeGoto(v, destIfFalse); - sqlite3VdbeJumpHere(v, addr1); - } - } - } - sqlite3ReleaseTempReg(pParse, r1); - sqlite3ExprCachePop(pParse); - VdbeComment((v, "end IN expr")); -} -#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==0 || (c==2 && negFlag) ){ - if( negFlag ){ value = c==2 ? SMALLEST_INT64 : -value; } - sqlite3VdbeAddOp4Dup8(v, OP_Int64, 0, iMem, 0, (u8*)&value, P4_INT64); - }else{ -#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", z); - }else -#endif - { - codeReal(v, z, negFlag, iMem); - } -#endif - } - } -} - -/* -** Clear a cache entry. -*/ -static void cacheEntryClear(Parse *pParse, struct yColCache *p){ - if( p->tempReg ){ - if( pParse->nTempReg<ArraySize(pParse->aTempReg) ){ - pParse->aTempReg[pParse->nTempReg++] = p->iReg; - } - p->tempReg = 0; - } -} - - -/* -** Record in the column cache that a particular column from a -** particular table is stored in a particular register. -*/ -void sqlite3ExprCacheStore(Parse *pParse, int iTab, int iCol, int iReg){ - int i; - int minLru; - int idxLru; - struct yColCache *p; - - /* Unless an error has occurred, register numbers are always positive. */ - assert( iReg>0 || pParse->nErr || pParse->db->mallocFailed ); - assert( iCol>=-1 && iCol<32768 ); /* Finite column numbers */ - - /* The SQLITE_ColumnCache flag disables the column cache. This is used - ** for testing only - to verify that SQLite always gets the same answer - ** with and without the column cache. - */ - if( OptimizationDisabled(pParse->db, SQLITE_ColumnCache) ) return; - - /* First replace any existing entry. - ** - ** Actually, the way the column cache is currently used, we are guaranteed - ** that the object will never already be in cache. Verify this guarantee. - */ -#ifndef NDEBUG - for(i=0, p=pParse->aColCache; i<SQLITE_N_COLCACHE; i++, p++){ - assert( p->iReg==0 || p->iTable!=iTab || p->iColumn!=iCol ); - } -#endif - - /* Find an empty slot and replace it */ - for(i=0, p=pParse->aColCache; i<SQLITE_N_COLCACHE; i++, p++){ - if( p->iReg==0 ){ - p->iLevel = pParse->iCacheLevel; - p->iTable = iTab; - p->iColumn = iCol; - p->iReg = iReg; - p->tempReg = 0; - p->lru = pParse->iCacheCnt++; - return; - } - } - - /* Replace the last recently used */ - minLru = 0x7fffffff; - idxLru = -1; - for(i=0, p=pParse->aColCache; i<SQLITE_N_COLCACHE; i++, p++){ - if( p->lru<minLru ){ - idxLru = i; - minLru = p->lru; - } - } - if( ALWAYS(idxLru>=0) ){ - p = &pParse->aColCache[idxLru]; - p->iLevel = pParse->iCacheLevel; - p->iTable = iTab; - p->iColumn = iCol; - p->iReg = iReg; - p->tempReg = 0; - p->lru = pParse->iCacheCnt++; - return; - } -} - -/* -** Indicate that registers between iReg..iReg+nReg-1 are being overwritten. -** Purge the range of registers from the column cache. -*/ -void sqlite3ExprCacheRemove(Parse *pParse, int iReg, int nReg){ - int i; - int iLast = iReg + nReg - 1; - struct yColCache *p; - for(i=0, p=pParse->aColCache; i<SQLITE_N_COLCACHE; i++, p++){ - int r = p->iReg; - if( r>=iReg && r<=iLast ){ - cacheEntryClear(pParse, p); - p->iReg = 0; - } - } -} - -/* -** Remember the current column cache context. Any new entries added -** added to the column cache after this call are removed when the -** corresponding pop occurs. -*/ -void sqlite3ExprCachePush(Parse *pParse){ - pParse->iCacheLevel++; -#ifdef SQLITE_DEBUG - if( pParse->db->flags & SQLITE_VdbeAddopTrace ){ - printf("PUSH to %d\n", pParse->iCacheLevel); - } -#endif -} - -/* -** Remove from the column cache any entries that were added since the -** the previous sqlite3ExprCachePush operation. In other words, restore -** the cache to the state it was in prior the most recent Push. -*/ -void sqlite3ExprCachePop(Parse *pParse){ - int i; - struct yColCache *p; - assert( pParse->iCacheLevel>=1 ); - pParse->iCacheLevel--; -#ifdef SQLITE_DEBUG - if( pParse->db->flags & SQLITE_VdbeAddopTrace ){ - printf("POP to %d\n", pParse->iCacheLevel); - } -#endif - for(i=0, p=pParse->aColCache; i<SQLITE_N_COLCACHE; i++, p++){ - if( p->iReg && p->iLevel>pParse->iCacheLevel ){ - cacheEntryClear(pParse, p); - p->iReg = 0; - } - } -} - -/* -** When a cached column is reused, make sure that its register is -** no longer available as a temp register. ticket #3879: that same -** register might be in the cache in multiple places, so be sure to -** get them all. -*/ -static void sqlite3ExprCachePinRegister(Parse *pParse, int iReg){ - int i; - struct yColCache *p; - for(i=0, p=pParse->aColCache; i<SQLITE_N_COLCACHE; i++, p++){ - if( p->iReg==iReg ){ - p->tempReg = 0; - } - } -} - -/* Generate code 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; - sqlite3ExprCode(pParse, pIdx->aColExpr->a[iIdxCol].pExpr, regOut); - }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( 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) ){ - 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 a register. An effort -** is made to store the column value in register iReg, but this is -** not guaranteed. The location of the column value is returned. -** -** There must be an open cursor to pTab in iTable when this routine -** is called. If iColumn<0 then code is generated that extracts the rowid. -*/ -int sqlite3ExprCodeGetColumn( - Parse *pParse, /* Parsing and code generating context */ - Table *pTab, /* Description of the table we are reading from */ - int iColumn, /* Index of the table column */ - int iTable, /* The cursor pointing to the table */ - int iReg, /* Store results here */ - u8 p5 /* P5 value for OP_Column */ -){ - Vdbe *v = pParse->pVdbe; - int i; - struct yColCache *p; - - for(i=0, p=pParse->aColCache; i<SQLITE_N_COLCACHE; i++, p++){ - if( p->iReg>0 && p->iTable==iTable && p->iColumn==iColumn ){ - p->lru = pParse->iCacheCnt++; - sqlite3ExprCachePinRegister(pParse, p->iReg); - return p->iReg; - } - } - assert( v!=0 ); - sqlite3ExprCodeGetColumnOfTable(v, pTab, iTable, iColumn, iReg); - if( p5 ){ - sqlite3VdbeChangeP5(v, p5); - }else{ - sqlite3ExprCacheStore(pParse, iTable, iColumn, iReg); - } - return iReg; -} - -/* -** Clear all column cache entries. -*/ -void sqlite3ExprCacheClear(Parse *pParse){ - int i; - struct yColCache *p; - -#if SQLITE_DEBUG - if( pParse->db->flags & SQLITE_VdbeAddopTrace ){ - printf("CLEAR\n"); - } -#endif - for(i=0, p=pParse->aColCache; i<SQLITE_N_COLCACHE; i++, p++){ - if( p->iReg ){ - cacheEntryClear(pParse, p); - p->iReg = 0; - } - } -} - -/* -** Record the fact that an affinity change has occurred on iCount -** registers starting with iStart. -*/ -void sqlite3ExprCacheAffinityChange(Parse *pParse, int iStart, int iCount){ - sqlite3ExprCacheRemove(pParse, iStart, iCount); -} - -/* -** Generate code to move content from registers iFrom...iFrom+nReg-1 -** over to iTo..iTo+nReg-1. Keep the column cache up-to-date. -*/ -void sqlite3ExprCodeMove(Parse *pParse, int iFrom, int iTo, int nReg){ - assert( iFrom>=iTo+nReg || iFrom+nReg<=iTo ); - sqlite3VdbeAddOp3(pParse->pVdbe, OP_Move, iFrom, iTo, nReg); - sqlite3ExprCacheRemove(pParse, iFrom, nReg); -} - -#if defined(SQLITE_DEBUG) || defined(SQLITE_COVERAGE_TEST) -/* -** Return true if any register in the range iFrom..iTo (inclusive) -** is used as part of the column cache. -** -** This routine is used within assert() and testcase() macros only -** and does not appear in a normal build. -*/ -static int usedAsColumnCache(Parse *pParse, int iFrom, int iTo){ - int i; - struct yColCache *p; - for(i=0, p=pParse->aColCache; i<SQLITE_N_COLCACHE; i++, p++){ - int r = p->iReg; - if( r>=iFrom && r<=iTo ) return 1; /*NO_TEST*/ - } - return 0; -} -#endif /* SQLITE_DEBUG || SQLITE_COVERAGE_TEST */ - -/* -** Convert an expression node to a TK_REGISTER -*/ -static void exprToRegister(Expr *p, int iReg){ - p->op2 = p->op; - p->op = TK_REGISTER; - p->iTable = iReg; - ExprClearProperty(p, EP_Skip); -} - -/* -** Generate code into the current Vdbe to evaluate the given -** expression. Attempt to store the results in register "target". -** Return the register where results are stored. -** -** With this routine, there is no guarantee that results will -** be stored in target. The result might be stored in some other -** register if it is convenient to do so. The calling function -** must check the return code and move the results to the desired -** register. -*/ -int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target){ - Vdbe *v = pParse->pVdbe; /* The VM under construction */ - int op; /* The opcode being coded */ - int inReg = target; /* Results stored in register inReg */ - int regFree1 = 0; /* If non-zero free this temporary register */ - int regFree2 = 0; /* If non-zero free this temporary register */ - int r1, r2, r3, r4; /* Various register numbers */ - sqlite3 *db = pParse->db; /* The database connection */ - Expr tempX; /* Temporary expression node */ - - assert( target>0 && target<=pParse->nMem ); - if( v==0 ){ - assert( pParse->db->mallocFailed ); - return 0; - } - - if( pExpr==0 ){ - op = TK_NULL; - }else{ - op = pExpr->op; - } - switch( op ){ - case TK_AGG_COLUMN: { - AggInfo *pAggInfo = pExpr->pAggInfo; - struct AggInfo_col *pCol = &pAggInfo->aCol[pExpr->iAgg]; - if( !pAggInfo->directMode ){ - assert( pCol->iMem>0 ); - inReg = pCol->iMem; - break; - }else if( pAggInfo->useSortingIdx ){ - sqlite3VdbeAddOp3(v, OP_Column, pAggInfo->sortingIdxPTab, - pCol->iSorterColumn, target); - break; - } - /* Otherwise, fall thru into the TK_COLUMN case */ - } - case TK_COLUMN: { - int iTab = pExpr->iTable; - if( iTab<0 ){ - if( pParse->ckBase>0 ){ - /* Generating CHECK constraints or inserting into partial index */ - inReg = pExpr->iColumn + pParse->ckBase; - break; - }else{ - /* 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; - } - } - inReg = sqlite3ExprCodeGetColumn(pParse, pExpr->pTab, - pExpr->iColumn, iTab, target, - pExpr->op2); - break; - } - case TK_INTEGER: { - codeInteger(pParse, pExpr, 0, target); - break; - } -#ifndef SQLITE_OMIT_FLOATING_POINT - case TK_FLOAT: { - assert( !ExprHasProperty(pExpr, EP_IntValue) ); - codeReal(v, pExpr->u.zToken, 0, target); - break; - } -#endif - case TK_STRING: { - assert( !ExprHasProperty(pExpr, EP_IntValue) ); - sqlite3VdbeLoadString(v, target, pExpr->u.zToken); - break; - } - case TK_NULL: { - sqlite3VdbeAddOp2(v, OP_Null, 0, target); - break; - } -#ifndef SQLITE_OMIT_BLOB_LITERAL - case TK_BLOB: { - int n; - const char *z; - char *zBlob; - assert( !ExprHasProperty(pExpr, EP_IntValue) ); - assert( pExpr->u.zToken[0]=='x' || pExpr->u.zToken[0]=='X' ); - assert( pExpr->u.zToken[1]=='\'' ); - z = &pExpr->u.zToken[2]; - n = sqlite3Strlen30(z) - 1; - assert( z[n]=='\'' ); - zBlob = sqlite3HexToBlob(sqlite3VdbeDb(v), z, n); - sqlite3VdbeAddOp4(v, OP_Blob, n/2, target, 0, zBlob, P4_DYNAMIC); - break; - } -#endif - case TK_VARIABLE: { - assert( !ExprHasProperty(pExpr, EP_IntValue) ); - assert( pExpr->u.zToken!=0 ); - assert( pExpr->u.zToken[0]!=0 ); - sqlite3VdbeAddOp2(v, OP_Variable, pExpr->iColumn, target); - if( pExpr->u.zToken[1]!=0 ){ - assert( pExpr->u.zToken[0]=='?' - || strcmp(pExpr->u.zToken, pParse->azVar[pExpr->iColumn-1])==0 ); - sqlite3VdbeChangeP4(v, -1, pParse->azVar[pExpr->iColumn-1], P4_STATIC); - } - break; - } - case TK_REGISTER: { - inReg = pExpr->iTable; - break; - } -#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)); - testcase( usedAsColumnCache(pParse, inReg, inReg) ); - sqlite3ExprCacheAffinityChange(pParse, inReg, 1); - break; - } -#endif /* SQLITE_OMIT_CAST */ - case TK_LT: - case TK_LE: - case TK_GT: - case TK_GE: - case TK_NE: - case TK_EQ: { - r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free1); - r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, ®Free2); - codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op, - r1, r2, inReg, SQLITE_STOREP2); - 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_IS: - case TK_ISNOT: { - testcase( op==TK_IS ); - testcase( op==TK_ISNOT ); - r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free1); - r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, ®Free2); - op = (op==TK_IS) ? TK_EQ : TK_NE; - codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op, - r1, r2, inReg, SQLITE_STOREP2 | SQLITE_NULLEQ); - VdbeCoverageIf(v, op==TK_EQ); - VdbeCoverageIf(v, op==TK_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); -#ifndef SQLITE_OMIT_FLOATING_POINT - }else if( pLeft->op==TK_FLOAT ){ - assert( !ExprHasProperty(pExpr, EP_IntValue) ); - codeReal(v, pLeft->u.zToken, 1, target); -#endif - }else{ - 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 ); - } - inReg = target; - 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 ); - inReg = target; - sqlite3VdbeAddOp2(v, op, r1, inReg); - 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{ - inReg = 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 */ - int nId; /* Length of the function name in bytes */ - const char *zId; /* The function name */ - u32 constMask = 0; /* Mask of function arguments that are constant */ - int i; /* Loop counter */ - u8 enc = ENC(db); /* The text encoding used by this database */ - CollSeq *pColl = 0; /* A collating sequence */ - - assert( !ExprHasProperty(pExpr, EP_xIsSelect) ); - if( ExprHasProperty(pExpr, EP_TokenOnly) ){ - pFarg = 0; - }else{ - pFarg = pExpr->x.pList; - } - nFarg = pFarg ? pFarg->nExpr : 0; - assert( !ExprHasProperty(pExpr, EP_IntValue) ); - zId = pExpr->u.zToken; - nId = sqlite3Strlen30(zId); - pDef = sqlite3FindFunction(db, zId, nId, nFarg, enc, 0); - if( pDef==0 || pDef->xFunc==0 ){ - sqlite3ErrorMsg(pParse, "unknown function: %.*s()", nId, 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(v); - assert( nFarg>=2 ); - sqlite3ExprCode(pParse, pFarg->a[0].pExpr, target); - for(i=1; i<nFarg; i++){ - sqlite3VdbeAddOp2(v, OP_NotNull, target, endCoalesce); - VdbeCoverage(v); - sqlite3ExprCacheRemove(pParse, target, 1); - sqlite3ExprCachePush(pParse); - sqlite3ExprCode(pParse, pFarg->a[i].pExpr, target); - sqlite3ExprCachePop(pParse); - } - 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 ); - inReg = sqlite3ExprCodeTarget(pParse, pFarg->a[0].pExpr, target); - break; - } - - for(i=0; i<nFarg; i++){ - if( i<32 && sqlite3ExprIsConstant(pFarg->a[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); - } - } - - sqlite3ExprCachePush(pParse); /* Ticket 2ea2425d34be */ - sqlite3ExprCodeExprList(pParse, pFarg, r1, 0, - SQLITE_ECEL_DUP|SQLITE_ECEL_FACTOR); - sqlite3ExprCachePop(pParse); /* Ticket 2ea2425d34be */ - }else{ - r1 = 0; - } -#ifndef SQLITE_OMIT_VIRTUALTABLE - /* Possibly overload the function if the first argument is - ** a virtual table column. - ** - ** For infix functions (LIKE, GLOB, REGEXP, and MATCH) use the - ** second argument, not the first, as the argument to test to - ** see if it is a column in a virtual table. This is done because - ** the left operand of infix functions (the operand we want to - ** control overloading) ends up as the second argument to the - ** function. The expression "A glob B" is equivalent to - ** "glob(B,A). We want to use the A in "A glob B" to test - ** for function overloading. But we use the B term in "glob(B,A)". - */ - if( nFarg>=2 && (pExpr->flags & EP_InfixFunc) ){ - pDef = sqlite3VtabOverloadFunction(db, pDef, nFarg, pFarg->a[1].pExpr); - }else if( nFarg>0 ){ - pDef = sqlite3VtabOverloadFunction(db, pDef, nFarg, pFarg->a[0].pExpr); - } -#endif - if( pDef->funcFlags & SQLITE_FUNC_NEEDCOLL ){ - if( !pColl ) pColl = db->pDfltColl; - sqlite3VdbeAddOp4(v, OP_CollSeq, 0, 0, 0, (char *)pColl, P4_COLLSEQ); - } - sqlite3VdbeAddOp4(v, OP_Function0, constMask, r1, target, - (char*)pDef, P4_FUNCDEF); - sqlite3VdbeChangeP5(v, (u8)nFarg); - if( nFarg && constMask==0 ){ - sqlite3ReleaseTempRange(pParse, r1, nFarg); - } - break; - } -#ifndef SQLITE_OMIT_SUBQUERY - case TK_EXISTS: - case TK_SELECT: { - testcase( op==TK_EXISTS ); - testcase( op==TK_SELECT ); - inReg = sqlite3CodeSubselect(pParse, pExpr, 0, 0); - break; - } - case TK_IN: { - int destIfFalse = sqlite3VdbeMakeLabel(v); - int destIfNull = sqlite3VdbeMakeLabel(v); - sqlite3VdbeAddOp2(v, OP_Null, 0, target); - sqlite3ExprCodeIN(pParse, pExpr, destIfFalse, destIfNull); - sqlite3VdbeAddOp2(v, OP_Integer, 1, target); - sqlite3VdbeResolveLabel(v, destIfFalse); - sqlite3VdbeAddOp2(v, OP_AddImm, target, 0); - sqlite3VdbeResolveLabel(v, destIfNull); - break; - } -#endif /* SQLITE_OMIT_SUBQUERY */ - - - /* - ** x BETWEEN y AND z - ** - ** This is equivalent to - ** - ** x>=y AND x<=z - ** - ** X is stored in pExpr->pLeft. - ** Y is stored in pExpr->pList->a[0].pExpr. - ** Z is stored in pExpr->pList->a[1].pExpr. - */ - case TK_BETWEEN: { - Expr *pLeft = pExpr->pLeft; - struct ExprList_item *pLItem = pExpr->x.pList->a; - Expr *pRight = pLItem->pExpr; - - r1 = sqlite3ExprCodeTemp(pParse, pLeft, ®Free1); - r2 = sqlite3ExprCodeTemp(pParse, pRight, ®Free2); - testcase( regFree1==0 ); - testcase( regFree2==0 ); - r3 = sqlite3GetTempReg(pParse); - r4 = sqlite3GetTempReg(pParse); - codeCompare(pParse, pLeft, pRight, OP_Ge, - r1, r2, r3, SQLITE_STOREP2); VdbeCoverage(v); - pLItem++; - pRight = pLItem->pExpr; - sqlite3ReleaseTempReg(pParse, regFree2); - r2 = sqlite3ExprCodeTemp(pParse, pRight, ®Free2); - testcase( regFree2==0 ); - codeCompare(pParse, pLeft, pRight, OP_Le, r1, r2, r4, SQLITE_STOREP2); - VdbeCoverage(v); - sqlite3VdbeAddOp3(v, OP_And, r3, r4, target); - sqlite3ReleaseTempReg(pParse, r3); - sqlite3ReleaseTempReg(pParse, r4); - break; - } - case TK_COLLATE: - case TK_UPLUS: { - inReg = sqlite3ExprCodeTarget(pParse, pExpr->pLeft, target); - break; - } - - case TK_TRIGGER: { - /* If the opcode is TK_TRIGGER, then the expression is a reference - ** to a column in the new.* or old.* pseudo-tables available to - ** trigger programs. In this case Expr.iTable is set to 1 for the - ** new.* pseudo-table, or 0 for the old.* pseudo-table. Expr.iColumn - ** is set to the column of the pseudo-table to read, or to -1 to - ** read the rowid field. - ** - ** The expression is implemented using an OP_Param opcode. The p1 - ** parameter is set to 0 for an old.rowid reference, or to (i+1) - ** to reference another column of the old.* pseudo-table, where - ** i is the index of the column. For a new.rowid reference, p1 is - ** set to (n+1), where n is the number of columns in each pseudo-table. - ** For a reference to any other column in the new.* pseudo-table, p1 - ** is set to (n+2+i), where n and i are as defined previously. For - ** example, if the table on which triggers are being fired is - ** declared as: - ** - ** CREATE TABLE t1(a, b); - ** - ** Then p1 is interpreted as follows: - ** - ** p1==0 -> old.rowid p1==3 -> new.rowid - ** p1==1 -> old.a p1==4 -> new.a - ** p1==2 -> old.b p1==5 -> new.b - */ - Table *pTab = pExpr->pTab; - int p1 = pExpr->iTable * (pTab->nCol+1) + 1 + pExpr->iColumn; - - assert( pExpr->iTable==0 || pExpr->iTable==1 ); - assert( pExpr->iColumn>=-1 && pExpr->iColumn<pTab->nCol ); - assert( pTab->iPKey<0 || pExpr->iColumn!=pTab->iPKey ); - assert( p1>=0 && p1<(pTab->nCol*2+2) ); - - sqlite3VdbeAddOp2(v, OP_Param, p1, target); - VdbeComment((v, "%s.%s -> $%d", - (pExpr->iTable ? "new" : "old"), - (pExpr->iColumn<0 ? "rowid" : pExpr->pTab->aCol[pExpr->iColumn].zName), - target - )); - -#ifndef SQLITE_OMIT_FLOATING_POINT - /* If the column has REAL affinity, it may currently be stored as an - ** integer. Use OP_RealAffinity to make sure it is really real. - ** - ** 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; - } - - - /* - ** 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) */ - VVA_ONLY( int iCacheLevel = pParse->iCacheLevel; ) - - assert( !ExprHasProperty(pExpr, EP_xIsSelect) && pExpr->x.pList ); - assert(pExpr->x.pList->nExpr > 0); - pEList = pExpr->x.pList; - aListelem = pEList->a; - nExpr = pEList->nExpr; - endLabel = sqlite3VdbeMakeLabel(v); - if( (pX = pExpr->pLeft)!=0 ){ - tempX = *pX; - testcase( pX->op==TK_COLUMN ); - exprToRegister(&tempX, sqlite3ExprCodeTemp(pParse, pX, ®Free1)); - testcase( regFree1==0 ); - 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; i<nExpr-1; i=i+2){ - sqlite3ExprCachePush(pParse); - if( pX ){ - assert( pTest!=0 ); - opCompare.pRight = aListelem[i].pExpr; - }else{ - pTest = aListelem[i].pExpr; - } - nextCase = sqlite3VdbeMakeLabel(v); - testcase( pTest->op==TK_COLUMN ); - sqlite3ExprIfFalse(pParse, pTest, nextCase, SQLITE_JUMPIFNULL); - testcase( aListelem[i+1].pExpr->op==TK_COLUMN ); - sqlite3ExprCode(pParse, aListelem[i+1].pExpr, target); - sqlite3VdbeGoto(v, endLabel); - sqlite3ExprCachePop(pParse); - sqlite3VdbeResolveLabel(v, nextCase); - } - if( (nExpr&1)!=0 ){ - sqlite3ExprCachePush(pParse); - sqlite3ExprCode(pParse, pEList->a[nExpr-1].pExpr, target); - sqlite3ExprCachePop(pParse); - }else{ - sqlite3VdbeAddOp2(v, OP_Null, 0, target); - } - assert( db->mallocFailed || pParse->nErr>0 - || pParse->iCacheLevel==iCacheLevel ); - sqlite3VdbeResolveLabel(v, endLabel); - break; - } -#ifndef SQLITE_OMIT_TRIGGER - case TK_RAISE: { - assert( pExpr->affinity==OE_Rollback - || pExpr->affinity==OE_Abort - || pExpr->affinity==OE_Fail - || pExpr->affinity==OE_Ignore - ); - if( !pParse->pTriggerTab ){ - sqlite3ErrorMsg(pParse, - "RAISE() may only be used within a trigger-program"); - return 0; - } - if( pExpr->affinity==OE_Abort ){ - sqlite3MayAbort(pParse); - } - assert( !ExprHasProperty(pExpr, EP_IntValue) ); - if( pExpr->affinity==OE_Ignore ){ - sqlite3VdbeAddOp4( - v, OP_Halt, SQLITE_OK, OE_Ignore, 0, pExpr->u.zToken,0); - 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. -*/ -void sqlite3ExprCodeAtInit( - Parse *pParse, /* Parsing context */ - Expr *pExpr, /* The expression to code when the VDBE initializes */ - int regDest, /* Store the value in this register */ - u8 reusable /* True if this expression is reusable */ -){ - ExprList *p; - assert( ConstFactorOk(pParse) ); - p = pParse->pConstExpr; - pExpr = sqlite3ExprDup(pParse->db, pExpr, 0); - p = sqlite3ExprListAppend(pParse, p, pExpr); - if( p ){ - struct ExprList_item *pItem = &p->a[p->nExpr-1]; - pItem->u.iConstExprReg = regDest; - pItem->reusable = reusable; - } - pParse->pConstExpr = p; -} - -/* -** 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) - ){ - ExprList *p = pParse->pConstExpr; - int i; - *pReg = 0; - if( p ){ - struct ExprList_item *pItem; - for(pItem=p->a, i=p->nExpr; i>0; pItem++, i--){ - if( pItem->reusable && sqlite3ExprCompare(pItem->pExpr,pExpr,-1)==0 ){ - return pItem->u.iConstExprReg; - } - } - } - r2 = ++pParse->nMem; - sqlite3ExprCodeAtInit(pParse, pExpr, r2, 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 || pParse->db->mallocFailed ); - if( inReg!=target && pParse->pVdbe ){ - sqlite3VdbeAddOp2(pParse->pVdbe, OP_SCopy, inReg, target); - } - } -} - -/* -** 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 && sqlite3ExprIsConstant(pExpr) ){ - sqlite3ExprCodeAtInit(pParse, pExpr, target, 0); - }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 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. -*/ -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; i<n; i++, pItem++){ - Expr *pExpr = pItem->pExpr; - if( (flags & SQLITE_ECEL_REF)!=0 && (j = pList->a[i].u.x.iOrderByCol)>0 ){ - sqlite3VdbeAddOp2(v, copyOp, j+srcReg-1, target+i); - }else if( (flags & SQLITE_ECEL_FACTOR)!=0 && sqlite3ExprIsConstant(pExpr) ){ - sqlite3ExprCodeAtInit(pParse, pExpr, target+i, 0); - }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. -*/ -static void exprCodeBetween( - Parse *pParse, /* Parsing and code generating context */ - Expr *pExpr, /* The BETWEEN expression */ - int dest, /* Jump here if the jump is taken */ - int jumpIfTrue, /* Take the jump if the BETWEEN is true */ - int jumpIfNull /* Take the jump if the BETWEEN is NULL */ -){ - Expr exprAnd; /* The AND operator in x>=y AND x<=z */ - Expr compLeft; /* The x>=y term */ - Expr compRight; /* The x<=z term */ - Expr exprX; /* The x subexpression */ - int regFree1 = 0; /* Temporary use register */ - - assert( !ExprHasProperty(pExpr, EP_xIsSelect) ); - exprX = *pExpr->pLeft; - exprAnd.op = TK_AND; - exprAnd.pLeft = &compLeft; - exprAnd.pRight = &compRight; - compLeft.op = TK_GE; - compLeft.pLeft = &exprX; - compLeft.pRight = pExpr->x.pList->a[0].pExpr; - compRight.op = TK_LE; - compRight.pLeft = &exprX; - compRight.pRight = pExpr->x.pList->a[1].pExpr; - exprToRegister(&exprX, sqlite3ExprCodeTemp(pParse, &exprX, ®Free1)); - if( jumpIfTrue ){ - sqlite3ExprIfTrue(pParse, &exprAnd, dest, jumpIfNull); - }else{ - sqlite3ExprIfFalse(pParse, &exprAnd, dest, jumpIfNull); - } - sqlite3ReleaseTempReg(pParse, regFree1); - - /* Ensure adequate test coverage */ - testcase( jumpIfTrue==0 && jumpIfNull==0 && regFree1==0 ); - testcase( jumpIfTrue==0 && jumpIfNull==0 && regFree1!=0 ); - testcase( jumpIfTrue==0 && jumpIfNull!=0 && regFree1==0 ); - testcase( jumpIfTrue==0 && jumpIfNull!=0 && regFree1!=0 ); - testcase( jumpIfTrue!=0 && jumpIfNull==0 && regFree1==0 ); - testcase( jumpIfTrue!=0 && jumpIfNull==0 && regFree1!=0 ); - testcase( jumpIfTrue!=0 && jumpIfNull!=0 && regFree1==0 ); - testcase( jumpIfTrue!=0 && jumpIfNull!=0 && regFree1!=0 ); -} - -/* -** Generate code for a boolean expression such that a jump is made -** to the label "dest" if the expression is true but execution -** continues straight thru if the expression is false. -** -** If the expression evaluates to NULL (neither true nor false), then -** take the jump if the jumpIfNull flag is SQLITE_JUMPIFNULL. -** -** This code depends on the fact that certain token values (ex: TK_EQ) -** are the same as opcode values (ex: OP_Eq) that implement the corresponding -** operation. Special comments in vdbe.c and the mkopcodeh.awk script in -** the make process cause these values to align. Assert()s in the code -** below verify that the numbers are aligned correctly. -*/ -void sqlite3ExprIfTrue(Parse *pParse, Expr *pExpr, int dest, int jumpIfNull){ - Vdbe *v = pParse->pVdbe; - int op = 0; - int regFree1 = 0; - int regFree2 = 0; - int r1, r2; - - assert( jumpIfNull==SQLITE_JUMPIFNULL || jumpIfNull==0 ); - if( NEVER(v==0) ) return; /* Existence of VDBE checked by caller */ - if( NEVER(pExpr==0) ) return; /* No way this can happen */ - op = pExpr->op; - switch( op ){ - case TK_AND: { - int d2 = sqlite3VdbeMakeLabel(v); - testcase( jumpIfNull==0 ); - sqlite3ExprIfFalse(pParse, pExpr->pLeft, d2,jumpIfNull^SQLITE_JUMPIFNULL); - sqlite3ExprCachePush(pParse); - sqlite3ExprIfTrue(pParse, pExpr->pRight, dest, jumpIfNull); - sqlite3VdbeResolveLabel(v, d2); - sqlite3ExprCachePop(pParse); - break; - } - case TK_OR: { - testcase( jumpIfNull==0 ); - sqlite3ExprIfTrue(pParse, pExpr->pLeft, dest, jumpIfNull); - sqlite3ExprCachePush(pParse); - sqlite3ExprIfTrue(pParse, pExpr->pRight, dest, jumpIfNull); - sqlite3ExprCachePop(pParse); - break; - } - case TK_NOT: { - testcase( jumpIfNull==0 ); - sqlite3ExprIfFalse(pParse, pExpr->pLeft, dest, jumpIfNull); - break; - } - case TK_LT: - case TK_LE: - case TK_GT: - case TK_GE: - case TK_NE: - case TK_EQ: { - 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); - assert(TK_NE==OP_Ne); testcase(op==OP_Ne); VdbeCoverageIf(v,op==OP_Ne); - testcase( regFree1==0 ); - testcase( regFree2==0 ); - break; - } - case TK_IS: - case TK_ISNOT: { - testcase( op==TK_IS ); - testcase( op==TK_ISNOT ); - r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free1); - r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, ®Free2); - op = (op==TK_IS) ? TK_EQ : TK_NE; - codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op, - r1, r2, dest, SQLITE_NULLEQ); - VdbeCoverageIf(v, op==TK_EQ); - VdbeCoverageIf(v, op==TK_NE); - 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, 1, jumpIfNull); - break; - } -#ifndef SQLITE_OMIT_SUBQUERY - case TK_IN: { - int destIfFalse = sqlite3VdbeMakeLabel(v); - int destIfNull = jumpIfNull ? dest : destIfFalse; - sqlite3ExprCodeIN(pParse, pExpr, destIfFalse, destIfNull); - sqlite3VdbeGoto(v, dest); - sqlite3VdbeResolveLabel(v, destIfFalse); - break; - } -#endif - default: { - 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: { - testcase( jumpIfNull==0 ); - sqlite3ExprIfFalse(pParse, pExpr->pLeft, dest, jumpIfNull); - sqlite3ExprCachePush(pParse); - sqlite3ExprIfFalse(pParse, pExpr->pRight, dest, jumpIfNull); - sqlite3ExprCachePop(pParse); - break; - } - case TK_OR: { - int d2 = sqlite3VdbeMakeLabel(v); - testcase( jumpIfNull==0 ); - sqlite3ExprIfTrue(pParse, pExpr->pLeft, d2, jumpIfNull^SQLITE_JUMPIFNULL); - sqlite3ExprCachePush(pParse); - sqlite3ExprIfFalse(pParse, pExpr->pRight, dest, jumpIfNull); - sqlite3VdbeResolveLabel(v, d2); - sqlite3ExprCachePop(pParse); - break; - } - case TK_NOT: { - testcase( jumpIfNull==0 ); - sqlite3ExprIfTrue(pParse, pExpr->pLeft, dest, jumpIfNull); - break; - } - case TK_LT: - case TK_LE: - case TK_GT: - case TK_GE: - case TK_NE: - case TK_EQ: { - testcase( 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); - assert(TK_NE==OP_Ne); testcase(op==OP_Ne); VdbeCoverageIf(v,op==OP_Ne); - testcase( regFree1==0 ); - testcase( regFree2==0 ); - break; - } - case TK_IS: - case TK_ISNOT: { - testcase( pExpr->op==TK_IS ); - testcase( pExpr->op==TK_ISNOT ); - r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free1); - r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, ®Free2); - op = (pExpr->op==TK_IS) ? TK_NE : TK_EQ; - codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op, - r1, r2, dest, SQLITE_NULLEQ); - VdbeCoverageIf(v, op==TK_EQ); - VdbeCoverageIf(v, op==TK_NE); - 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, 0, jumpIfNull); - break; - } -#ifndef SQLITE_OMIT_SUBQUERY - case TK_IN: { - if( jumpIfNull ){ - sqlite3ExprCodeIN(pParse, pExpr, dest, dest); - }else{ - int destIfNull = sqlite3VdbeMakeLabel(v); - sqlite3ExprCodeIN(pParse, pExpr, dest, destIfNull); - sqlite3VdbeResolveLabel(v, destIfNull); - } - break; - } -#endif - default: { - 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); -} - - -/* -** Do a deep comparison of two expression trees. Return 0 if the two -** expressions are completely identical. Return 1 if they differ only -** by a COLLATE operator at the top level. Return 2 if there are differences -** other than the top-level COLLATE operator. -** -** If any subelement of pB has Expr.iTable==(-1) then it is allowed -** to compare equal to an equivalent element in pA with Expr.iTable==iTab. -** -** The pA side might be using TK_REGISTER. If that is the case and pB is -** not using TK_REGISTER but is otherwise equivalent, then still return 0. -** -** Sometimes this routine will return 2 even if the two expressions -** really are equivalent. If we cannot prove that the expressions are -** identical, we return 2 just to be safe. So if this routine -** returns 2, then you do not really know for certain if the two -** expressions are the same. But if you get a 0 or 1 return, then you -** can be sure the expressions are the same. In the places where -** this routine is used, it does not hurt to get an extra 2 - that -** just might result in some slightly slower code. But returning -** an incorrect 0 or 1 could lead to a malfunction. -*/ -int sqlite3ExprCompare(Expr *pA, Expr *pB, int iTab){ - u32 combinedFlags; - if( pA==0 || pB==0 ){ - return pB==pA ? 0 : 2; - } - 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 ){ - if( pA->op==TK_COLLATE && sqlite3ExprCompare(pA->pLeft, pB, iTab)<2 ){ - return 1; - } - if( pB->op==TK_COLLATE && sqlite3ExprCompare(pA, pB->pLeft, iTab)<2 ){ - return 1; - } - return 2; - } - if( pA->op!=TK_COLUMN && ALWAYS(pA->op!=TK_AGG_COLUMN) && pA->u.zToken ){ - if( pA->op==TK_FUNCTION ){ - if( sqlite3StrICmp(pA->u.zToken,pB->u.zToken)!=0 ) return 2; - }else if( strcmp(pA->u.zToken,pB->u.zToken)!=0 ){ - return pA->op==TK_COLLATE ? 1 : 2; - } - } - if( (pA->flags & EP_Distinct)!=(pB->flags & EP_Distinct) ) return 2; - if( ALWAYS((combinedFlags & EP_TokenOnly)==0) ){ - if( combinedFlags & EP_xIsSelect ) return 2; - if( sqlite3ExprCompare(pA->pLeft, pB->pLeft, iTab) ) return 2; - if( sqlite3ExprCompare(pA->pRight, pB->pRight, iTab) ) return 2; - if( sqlite3ExprListCompare(pA->x.pList, pB->x.pList, iTab) ) return 2; - if( ALWAYS((combinedFlags & EP_Reduced)==0) && pA->op!=TK_STRING ){ - if( pA->iColumn!=pB->iColumn ) 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; i<pA->nExpr; i++){ - Expr *pExprA = pA->a[i].pExpr; - Expr *pExprB = pB->a[i].pExpr; - if( pA->a[i].sortOrder!=pB->a[i].sortOrder ) return 1; - if( sqlite3ExprCompare(pExprA, pExprB, iTab) ) return 1; - } - return 0; -} - -/* -** Return true if we can prove the pE2 will always be true if pE1 is -** true. Return false if we cannot complete the proof or if pE2 might -** be false. Examples: -** -** pE1: x==5 pE2: x==5 Result: true -** pE1: x>0 pE2: x==5 Result: false -** pE1: x=21 pE2: x=21 OR y=43 Result: true -** pE1: x!=123 pE2: x IS NOT NULL Result: true -** pE1: x!=?1 pE2: x IS NOT NULL Result: true -** pE1: x IS NULL pE2: x IS NOT NULL Result: false -** pE1: x IS ?2 pE2: x IS NOT NULL Reuslt: false -** -** When comparing TK_COLUMN nodes between pE1 and pE2, if pE2 has -** Expr.iTable<0 then assume a table number given by iTab. -** -** When in doubt, return false. Returning true might give a performance -** improvement. Returning false might cause a performance reduction, but -** it will always give the correct answer and is hence always safe. -*/ -int sqlite3ExprImpliesExpr(Expr *pE1, Expr *pE2, int iTab){ - if( sqlite3ExprCompare(pE1, pE2, iTab)==0 ){ - return 1; - } - if( pE2->op==TK_OR - && (sqlite3ExprImpliesExpr(pE1, pE2->pLeft, iTab) - || sqlite3ExprImpliesExpr(pE1, pE2->pRight, iTab) ) - ){ - return 1; - } - if( pE2->op==TK_NOTNULL - && sqlite3ExprCompare(pE1->pLeft, pE2->pLeft, iTab)==0 - && (pE1->op!=TK_ISNULL && pE1->op!=TK_IS) - ){ - return 1; - } - return 0; -} - -/* -** An instance of the following structure is used by the tree walker -** to count references to table columns in the arguments of an -** aggregate function, in order to implement the -** sqlite3FunctionThisSrc() routine. -*/ -struct SrcCount { - SrcList *pSrc; /* One particular FROM clause in a nested query */ - int nThis; /* Number of references to columns in pSrcList */ - int nOther; /* Number of references to columns in other FROM clauses */ -}; - -/* -** Count the number of references to columns. -*/ -static int exprSrcCount(Walker *pWalker, Expr *pExpr){ - /* The NEVER() on the second term is because sqlite3FunctionUsesThisSrc() - ** is always called before sqlite3ExprAnalyzeAggregates() and so the - ** TK_COLUMNs have not yet been converted into TK_AGG_COLUMN. If - ** sqlite3FunctionUsesThisSrc() is used differently in the future, the - ** NEVER() will need to be removed. */ - if( pExpr->op==TK_COLUMN || NEVER(pExpr->op==TK_AGG_COLUMN) ){ - int i; - struct SrcCount *p = pWalker->u.pSrcCount; - SrcList *pSrc = p->pSrc; - int nSrc = pSrc ? pSrc->nSrc : 0; - for(i=0; i<nSrc; i++){ - if( pExpr->iTable==pSrc->a[i].iCursor ) break; - } - if( i<nSrc ){ - p->nThis++; - }else{ - p->nOther++; - } - } - return WRC_Continue; -} - -/* -** Determine if any of the arguments to the pExpr Function reference -** pSrcList. Return true if they do. Also return true if the function -** has no arguments or has only constant arguments. Return false if pExpr -** references columns but not columns of tables found in pSrcList. -*/ -int sqlite3FunctionUsesThisSrc(Expr *pExpr, SrcList *pSrcList){ - Walker w; - struct SrcCount cnt; - assert( pExpr->op==TK_AGG_FUNCTION ); - memset(&w, 0, sizeof(w)); - w.xExprCallback = exprSrcCount; - w.u.pSrcCount = &cnt; - cnt.pSrc = pSrcList; - cnt.nThis = 0; - cnt.nOther = 0; - sqlite3WalkExprList(&w, pExpr->x.pList); - return cnt.nThis>0 || cnt.nOther==0; -} - -/* -** Add a new element to the pAggInfo->aCol[] array. Return the index of -** the new element. Return a negative number if malloc fails. -*/ -static int addAggInfoColumn(sqlite3 *db, AggInfo *pInfo){ - int i; - pInfo->aCol = sqlite3ArrayAllocate( - db, - pInfo->aCol, - sizeof(pInfo->aCol[0]), - &pInfo->nColumn, - &i - ); - return i; -} - -/* -** Add a new element to the pAggInfo->aFunc[] array. Return the index of -** the new element. Return a negative number if malloc fails. -*/ -static int addAggInfoFunc(sqlite3 *db, AggInfo *pInfo){ - int i; - pInfo->aFunc = sqlite3ArrayAllocate( - db, - pInfo->aFunc, - sizeof(pInfo->aFunc[0]), - &pInfo->nFunc, - &i - ); - return i; -} - -/* -** This is the xExprCallback for a tree walker. It is used to -** implement sqlite3ExprAnalyzeAggregates(). See sqlite3ExprAnalyzeAggregates -** for additional information. -*/ -static int analyzeAggregate(Walker *pWalker, Expr *pExpr){ - int i; - NameContext *pNC = pWalker->u.pNC; - Parse *pParse = pNC->pParse; - SrcList *pSrcList = pNC->pSrcList; - AggInfo *pAggInfo = pNC->pAggInfo; - - switch( pExpr->op ){ - case TK_AGG_COLUMN: - case TK_COLUMN: { - testcase( pExpr->op==TK_AGG_COLUMN ); - testcase( pExpr->op==TK_COLUMN ); - /* Check to see if the column is in one of the tables in the FROM - ** clause of the aggregate query */ - if( ALWAYS(pSrcList!=0) ){ - struct SrcList_item *pItem = pSrcList->a; - for(i=0; i<pSrcList->nSrc; i++, pItem++){ - struct AggInfo_col *pCol; - assert( !ExprHasProperty(pExpr, EP_TokenOnly|EP_Reduced) ); - if( pExpr->iTable==pItem->iCursor ){ - /* If we reach this point, it means that pExpr refers to a table - ** that is in the FROM clause of the aggregate query. - ** - ** Make an entry for the column in pAggInfo->aCol[] if there - ** is not an entry there already. - */ - int k; - pCol = pAggInfo->aCol; - for(k=0; k<pAggInfo->nColumn; k++, pCol++){ - if( pCol->iTable==pExpr->iTable && - pCol->iColumn==pExpr->iColumn ){ - break; - } - } - if( (k>=pAggInfo->nColumn) - && (k = addAggInfoColumn(pParse->db, pAggInfo))>=0 - ){ - pCol = &pAggInfo->aCol[k]; - pCol->pTab = pExpr->pTab; - pCol->iTable = pExpr->iTable; - pCol->iColumn = pExpr->iColumn; - pCol->iMem = ++pParse->nMem; - pCol->iSorterColumn = -1; - pCol->pExpr = pExpr; - if( pAggInfo->pGroupBy ){ - int j, n; - ExprList *pGB = pAggInfo->pGroupBy; - struct ExprList_item *pTerm = pGB->a; - n = pGB->nExpr; - for(j=0; j<n; j++, pTerm++){ - Expr *pE = pTerm->pExpr; - if( pE->op==TK_COLUMN && pE->iTable==pExpr->iTable && - pE->iColumn==pExpr->iColumn ){ - pCol->iSorterColumn = j; - break; - } - } - } - if( pCol->iSorterColumn<0 ){ - pCol->iSorterColumn = pAggInfo->nSortingColumn++; - } - } - /* There is now an entry for pExpr in pAggInfo->aCol[] (either - ** because it was there before or because we just created it). - ** Convert the pExpr to be a TK_AGG_COLUMN referring to that - ** pAggInfo->aCol[] entry. - */ - ExprSetVVAProperty(pExpr, EP_NoReduce); - pExpr->pAggInfo = pAggInfo; - pExpr->op = TK_AGG_COLUMN; - pExpr->iAgg = (i16)k; - break; - } /* endif pExpr->iTable==pItem->iCursor */ - } /* end loop over pSrcList */ - } - return WRC_Prune; - } - case TK_AGG_FUNCTION: { - if( (pNC->ncFlags & NC_InAggFunc)==0 - && pWalker->walkerDepth==pExpr->op2 - ){ - /* Check to see if pExpr is a duplicate of another aggregate - ** function that is already in the pAggInfo structure - */ - struct AggInfo_func *pItem = pAggInfo->aFunc; - for(i=0; i<pAggInfo->nFunc; i++, pItem++){ - if( sqlite3ExprCompare(pItem->pExpr, pExpr, -1)==0 ){ - break; - } - } - if( i>=pAggInfo->nFunc ){ - /* pExpr is original. Make a new entry in pAggInfo->aFunc[] - */ - u8 enc = ENC(pParse->db); - i = addAggInfoFunc(pParse->db, pAggInfo); - if( i>=0 ){ - assert( !ExprHasProperty(pExpr, EP_xIsSelect) ); - pItem = &pAggInfo->aFunc[i]; - pItem->pExpr = pExpr; - pItem->iMem = ++pParse->nMem; - assert( !ExprHasProperty(pExpr, EP_IntValue) ); - pItem->pFunc = sqlite3FindFunction(pParse->db, - pExpr->u.zToken, sqlite3Strlen30(pExpr->u.zToken), - pExpr->x.pList ? pExpr->x.pList->nExpr : 0, enc, 0); - if( pExpr->flags & EP_Distinct ){ - pItem->iDistinct = pParse->nTab++; - }else{ - pItem->iDistinct = -1; - } - } - } - /* Make pExpr point to the appropriate pAggInfo->aFunc[] entry - */ - assert( !ExprHasProperty(pExpr, EP_TokenOnly|EP_Reduced) ); - ExprSetVVAProperty(pExpr, EP_NoReduce); - pExpr->iAgg = (i16)i; - pExpr->pAggInfo = pAggInfo; - return WRC_Prune; - }else{ - return WRC_Continue; - } - } - } - return WRC_Continue; -} -static int analyzeAggregatesInSelect(Walker *pWalker, Select *pSelect){ - UNUSED_PARAMETER(pWalker); - UNUSED_PARAMETER(pSelect); - return WRC_Continue; -} - -/* -** Analyze the pExpr expression looking for aggregate functions and -** for variables that need to be added to AggInfo object that pNC->pAggInfo -** points to. Additional entries are made on the AggInfo object as -** necessary. -** -** This routine should only be called after the expression has been -** analyzed by sqlite3ResolveExprNames(). -*/ -void sqlite3ExprAnalyzeAggregates(NameContext *pNC, Expr *pExpr){ - Walker w; - memset(&w, 0, sizeof(w)); - w.xExprCallback = analyzeAggregate; - w.xSelectCallback = analyzeAggregatesInSelect; - w.u.pNC = pNC; - assert( pNC->pSrcList!=0 ); - sqlite3WalkExpr(&w, pExpr); -} - -/* -** Call sqlite3ExprAnalyzeAggregates() for every expression in an -** expression list. Return the number of errors. -** -** If an error is found, the analysis is cut short. -*/ -void sqlite3ExprAnalyzeAggList(NameContext *pNC, ExprList *pList){ - struct ExprList_item *pItem; - int i; - if( pList ){ - for(pItem=pList->a, i=0; i<pList->nExpr; i++, pItem++){ - sqlite3ExprAnalyzeAggregates(pNC, pItem->pExpr); - } - } -} - -/* -** Allocate a single new register for use to hold some intermediate result. -*/ -int sqlite3GetTempReg(Parse *pParse){ - if( pParse->nTempReg==0 ){ - return ++pParse->nMem; - } - return pParse->aTempReg[--pParse->nTempReg]; -} - -/* -** Deallocate a register, making available for reuse for some other -** purpose. -** -** If a register is currently being used by the column cache, then -** the deallocation is deferred until the column cache line that uses -** the register becomes stale. -*/ -void sqlite3ReleaseTempReg(Parse *pParse, int iReg){ - if( iReg && pParse->nTempReg<ArraySize(pParse->aTempReg) ){ - int i; - struct yColCache *p; - for(i=0, p=pParse->aColCache; i<SQLITE_N_COLCACHE; i++, p++){ - if( p->iReg==iReg ){ - p->tempReg = 1; - return; - } - } - pParse->aTempReg[pParse->nTempReg++] = iReg; - } -} - -/* -** Allocate or deallocate a block of nReg consecutive registers -*/ -int sqlite3GetTempRange(Parse *pParse, int nReg){ - int i, n; - i = pParse->iRangeReg; - n = pParse->nRangeReg; - if( nReg<=n ){ - assert( !usedAsColumnCache(pParse, i, i+n-1) ); - pParse->iRangeReg += nReg; - pParse->nRangeReg -= nReg; - }else{ - i = pParse->nMem+1; - pParse->nMem += nReg; - } - return i; -} -void sqlite3ReleaseTempRange(Parse *pParse, int iReg, int nReg){ - sqlite3ExprCacheRemove(pParse, iReg, nReg); - if( nReg>pParse->nRangeReg ){ - pParse->nRangeReg = nReg; - pParse->iRangeReg = iReg; - } -} - -/* -** Mark all temporary registers as being unavailable for reuse. -*/ -void sqlite3ClearTempRegCache(Parse *pParse){ - pParse->nTempReg = 0; - pParse->nRangeReg = 0; -} |