diff options
Diffstat (limited to 'src/expr.c')
| -rw-r--r-- | src/expr.c | 3764 |
1 files changed, 3764 insertions, 0 deletions
diff --git a/src/expr.c b/src/expr.c new file mode 100644 index 0000000..d506173 --- /dev/null +++ b/src/expr.c @@ -0,0 +1,3764 @@ +/* +** 2001 September 15 +** +** The author disclaims copyright to this source code. In place of +** a legal notice, here is a blessing: +** +** May you do good and not evil. +** May you find forgiveness for yourself and forgive others. +** May you share freely, never taking more than you give. +** +************************************************************************* +** This file contains routines used for analyzing expressions and +** for generating VDBE code that evaluates expressions in SQLite. +*/ +#include "sqliteInt.h" + +/* +** Return the 'affinity' of the expression pExpr if any. +** +** If pExpr is a column, a reference to a column via an 'AS' alias, +** or a sub-select with a column as the return value, then the +** affinity of that column is returned. Otherwise, 0x00 is returned, +** indicating no affinity for the expression. +** +** i.e. the WHERE clause expresssions in the following statements all +** have an affinity: +** +** CREATE TABLE t1(a); +** SELECT * FROM t1 WHERE a; +** SELECT a AS b FROM t1 WHERE b; +** SELECT * FROM t1 WHERE (select a from t1); +*/ +char sqlite3ExprAffinity(Expr *pExpr){ + int op = pExpr->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); + } +#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 explicit collating sequence for an expression to the +** collating sequence supplied in the second argument. +*/ +Expr *sqlite3ExprSetColl(Expr *pExpr, CollSeq *pColl){ + if( pExpr && pColl ){ + pExpr->pColl = pColl; + pExpr->flags |= EP_ExpCollate; + } + return pExpr; +} + +/* +** Set the collating sequence for expression pExpr to be the collating +** sequence named by pToken. Return a pointer to the revised expression. +** The collating sequence is marked as "explicit" using the EP_ExpCollate +** flag. An explicit collating sequence will override implicit +** collating sequences. +*/ +Expr *sqlite3ExprSetCollByToken(Parse *pParse, Expr *pExpr, Token *pCollName){ + char *zColl = 0; /* Dequoted name of collation sequence */ + CollSeq *pColl; + sqlite3 *db = pParse->db; + zColl = sqlite3NameFromToken(db, pCollName); + pColl = sqlite3LocateCollSeq(pParse, zColl); + sqlite3ExprSetColl(pExpr, pColl); + sqlite3DbFree(db, zColl); + return pExpr; +} + +/* +** Return the default collation sequence for the expression pExpr. If +** there is no default collation type, return 0. +*/ +CollSeq *sqlite3ExprCollSeq(Parse *pParse, Expr *pExpr){ + CollSeq *pColl = 0; + Expr *p = pExpr; + while( p ){ + int op; + pColl = p->pColl; + if( pColl ) break; + op = p->op; + if( p->pTab!=0 && ( + op==TK_AGG_COLUMN || op==TK_COLUMN || op==TK_REGISTER || op==TK_TRIGGER + )){ + /* op==TK_REGISTER && p->pTab!=0 happens when pExpr was originally + ** a TK_COLUMN but was previously evaluated and cached in a register */ + const char *zColl; + int j = p->iColumn; + if( j>=0 ){ + sqlite3 *db = pParse->db; + zColl = p->pTab->aCol[j].zColl; + pColl = sqlite3FindCollSeq(db, ENC(db), zColl, 0); + pExpr->pColl = pColl; + } + break; + } + if( op!=TK_CAST && op!=TK_UPLUS ){ + break; + } + p = p->pLeft; + } + if( sqlite3CheckCollSeq(pParse, pColl) ){ + pColl = 0; + } + return pColl; +} + +/* +** pExpr is an operand of a comparison operator. aff2 is the +** type affinity of the other operand. This routine returns the +** type affinity that should be used for the comparison operator. +*/ +char sqlite3CompareAffinity(Expr *pExpr, char aff2){ + char aff1 = sqlite3ExprAffinity(pExpr); + if( aff1 && aff2 ){ + /* Both sides of the comparison are columns. If one has numeric + ** affinity, use that. Otherwise use no affinity. + */ + if( sqlite3IsNumericAffinity(aff1) || sqlite3IsNumericAffinity(aff2) ){ + return SQLITE_AFF_NUMERIC; + }else{ + return SQLITE_AFF_NONE; + } + }else if( !aff1 && !aff2 ){ + /* Neither side of the comparison is a column. Compare the + ** results directly. + */ + return SQLITE_AFF_NONE; + }else{ + /* One side is a column, the other is not. Use the columns affinity. */ + assert( aff1==0 || aff2==0 ); + return (aff1 + aff2); + } +} + +/* +** pExpr is a comparison operator. Return the type affinity that should +** be applied to both operands prior to doing the comparison. +*/ +static char comparisonAffinity(Expr *pExpr){ + char aff; + assert( pExpr->op==TK_EQ || pExpr->op==TK_IN || pExpr->op==TK_LT || + pExpr->op==TK_GT || pExpr->op==TK_GE || pExpr->op==TK_LE || + pExpr->op==TK_NE || pExpr->op==TK_IS || pExpr->op==TK_ISNOT ); + assert( pExpr->pLeft ); + aff = sqlite3ExprAffinity(pExpr->pLeft); + if( pExpr->pRight ){ + aff = sqlite3CompareAffinity(pExpr->pRight, aff); + }else if( ExprHasProperty(pExpr, EP_xIsSelect) ){ + aff = sqlite3CompareAffinity(pExpr->x.pSelect->pEList->a[0].pExpr, aff); + }else if( !aff ){ + aff = SQLITE_AFF_NONE; + } + return aff; +} + +/* +** pExpr is a comparison expression, eg. '=', '<', IN(...) etc. +** idx_affinity is the affinity of an indexed column. Return true +** if the index with affinity idx_affinity may be used to implement +** the comparison in pExpr. +*/ +int sqlite3IndexAffinityOk(Expr *pExpr, char idx_affinity){ + char aff = comparisonAffinity(pExpr); + switch( aff ){ + case SQLITE_AFF_NONE: + return 1; + case SQLITE_AFF_TEXT: + return idx_affinity==SQLITE_AFF_TEXT; + default: + return sqlite3IsNumericAffinity(idx_affinity); + } +} + +/* +** Return the P5 value that should be used for a binary comparison +** opcode (OP_Eq, OP_Ge etc.) used to compare pExpr1 and pExpr2. +*/ +static u8 binaryCompareP5(Expr *pExpr1, Expr *pExpr2, int jumpIfNull){ + u8 aff = (char)sqlite3ExprAffinity(pExpr2); + aff = (u8)sqlite3CompareAffinity(pExpr1, aff) | (u8)jumpIfNull; + return aff; +} + +/* +** Return a pointer to the collation sequence that should be used by +** a binary comparison operator comparing pLeft and pRight. +** +** If the left hand expression has a collating sequence type, then it is +** used. Otherwise the collation sequence for the right hand expression +** is used, or the default (BINARY) if neither expression has a collating +** type. +** +** Argument pRight (but not pLeft) may be a null pointer. In this case, +** it is not considered. +*/ +CollSeq *sqlite3BinaryCompareCollSeq( + Parse *pParse, + Expr *pLeft, + Expr *pRight +){ + CollSeq *pColl; + assert( pLeft ); + if( pLeft->flags & EP_ExpCollate ){ + assert( pLeft->pColl ); + pColl = pLeft->pColl; + }else if( pRight && pRight->flags & EP_ExpCollate ){ + assert( pRight->pColl ); + pColl = pRight->pColl; + }else{ + pColl = sqlite3ExprCollSeq(pParse, pLeft); + if( !pColl ){ + pColl = sqlite3ExprCollSeq(pParse, pRight); + } + } + return pColl; +} + +/* +** Generate code for a comparison operator. +*/ +static int codeCompare( + Parse *pParse, /* The parsing (and code generating) context */ + Expr *pLeft, /* The left operand */ + Expr *pRight, /* The right operand */ + int opcode, /* The comparison opcode */ + int in1, int in2, /* Register holding operands */ + int dest, /* Jump here if true. */ + int jumpIfNull /* If true, jump if either operand is NULL */ +){ + int p5; + int addr; + CollSeq *p4; + + p4 = sqlite3BinaryCompareCollSeq(pParse, pLeft, pRight); + p5 = binaryCompareP5(pLeft, pRight, jumpIfNull); + addr = sqlite3VdbeAddOp4(pParse->pVdbe, opcode, in2, dest, in1, + (void*)p4, P4_COLLSEQ); + sqlite3VdbeChangeP5(pParse->pVdbe, (u8)p5); + return addr; +} + +#if SQLITE_MAX_EXPR_DEPTH>0 +/* +** Check that argument nHeight is less than or equal to the maximum +** expression depth allowed. If it is not, leave an error message in +** pParse. +*/ +int sqlite3ExprCheckHeight(Parse *pParse, int nHeight){ + int rc = SQLITE_OK; + int mxHeight = pParse->db->aLimit[SQLITE_LIMIT_EXPR_DEPTH]; + if( nHeight>mxHeight ){ + sqlite3ErrorMsg(pParse, + "Expression tree is too large (maximum depth %d)", mxHeight + ); + rc = SQLITE_ERROR; + } + return rc; +} + +/* The following three functions, heightOfExpr(), heightOfExprList() +** and heightOfSelect(), are used to determine the maximum height +** of any expression tree referenced by the structure passed as the +** first argument. +** +** If this maximum height is greater than the current value pointed +** to by pnHeight, the second parameter, then set *pnHeight to that +** value. +*/ +static void heightOfExpr(Expr *p, int *pnHeight){ + if( p ){ + if( p->nHeight>*pnHeight ){ + *pnHeight = p->nHeight; + } + } +} +static void heightOfExprList(ExprList *p, int *pnHeight){ + if( p ){ + int i; + for(i=0; i<p->nExpr; i++){ + heightOfExpr(p->a[i].pExpr, pnHeight); + } + } +} +static void heightOfSelect(Select *p, int *pnHeight){ + if( p ){ + heightOfExpr(p->pWhere, pnHeight); + heightOfExpr(p->pHaving, pnHeight); + heightOfExpr(p->pLimit, pnHeight); + heightOfExpr(p->pOffset, pnHeight); + heightOfExprList(p->pEList, pnHeight); + heightOfExprList(p->pGroupBy, pnHeight); + heightOfExprList(p->pOrderBy, pnHeight); + heightOfSelect(p->pPrior, pnHeight); + } +} + +/* +** Set the Expr.nHeight variable in the structure passed as an +** argument. An expression with no children, Expr.pList or +** Expr.pSelect member has a height of 1. Any other expression +** has a height equal to the maximum height of any other +** referenced Expr plus one. +*/ +static void exprSetHeight(Expr *p){ + int nHeight = 0; + heightOfExpr(p->pLeft, &nHeight); + heightOfExpr(p->pRight, &nHeight); + if( ExprHasProperty(p, EP_xIsSelect) ){ + heightOfSelect(p->x.pSelect, &nHeight); + }else{ + heightOfExprList(p->x.pList, &nHeight); + } + p->nHeight = nHeight + 1; +} + +/* +** Set the Expr.nHeight variable using the exprSetHeight() function. If +** the height is greater than the maximum allowed expression depth, +** leave an error in pParse. +*/ +void sqlite3ExprSetHeight(Parse *pParse, Expr *p){ + exprSetHeight(p); + sqlite3ExprCheckHeight(pParse, p->nHeight); +} + +/* +** Return the maximum height of any expression tree referenced +** by the select statement passed as an argument. +*/ +int sqlite3SelectExprHeight(Select *p){ + int nHeight = 0; + heightOfSelect(p, &nHeight); + return nHeight; +} +#else + #define exprSetHeight(y) +#endif /* SQLITE_MAX_EXPR_DEPTH>0 */ + +/* +** This routine is the core allocator for Expr nodes. +** +** Construct a new expression node and return a pointer to it. Memory +** for this node and for the pToken argument is a single allocation +** obtained from sqlite3DbMalloc(). The calling function +** is responsible for making sure the node eventually gets freed. +** +** If dequote is true, then the token (if it exists) is dequoted. +** If dequote is false, no dequoting is performance. The deQuote +** parameter is ignored if pToken is NULL or if the token does not +** appear to be quoted. If the quotes were of the form "..." (double-quotes) +** then the EP_DblQuoted flag is set on the expression node. +** +** Special case: If op==TK_INTEGER and pToken points to a string that +** can be translated into a 32-bit integer, then the token is not +** stored in u.zToken. Instead, the integer values is written +** into u.iValue and the EP_IntValue flag is set. No extra storage +** is allocated to hold the integer text and the dequote flag is ignored. +*/ +Expr *sqlite3ExprAlloc( + sqlite3 *db, /* Handle for sqlite3DbMallocZero() (may be null) */ + int op, /* Expression opcode */ + const Token *pToken, /* Token argument. Might be NULL */ + int dequote /* True to dequote */ +){ + Expr *pNew; + int nExtra = 0; + int iValue = 0; + + if( pToken ){ + if( op!=TK_INTEGER || pToken->z==0 + || sqlite3GetInt32(pToken->z, &iValue)==0 ){ + nExtra = pToken->n+1; + assert( iValue>=0 ); + } + } + pNew = sqlite3DbMallocZero(db, sizeof(Expr)+nExtra); + if( pNew ){ + pNew->op = (u8)op; + pNew->iAgg = -1; + if( pToken ){ + if( nExtra==0 ){ + pNew->flags |= EP_IntValue; + pNew->u.iValue = iValue; + }else{ + int c; + pNew->u.zToken = (char*)&pNew[1]; + assert( pToken->z!=0 || pToken->n==0 ); + if( pToken->n ) memcpy(pNew->u.zToken, pToken->z, pToken->n); + pNew->u.zToken[pToken->n] = 0; + if( dequote && nExtra>=3 + && ((c = pToken->z[0])=='\'' || c=='"' || c=='[' || c=='`') ){ + sqlite3Dequote(pNew->u.zToken); + if( c=='"' ) pNew->flags |= EP_DblQuoted; + } + } + } +#if SQLITE_MAX_EXPR_DEPTH>0 + pNew->nHeight = 1; +#endif + } + return pNew; +} + +/* +** Allocate a new expression node from a zero-terminated token that has +** already been dequoted. +*/ +Expr *sqlite3Expr( + sqlite3 *db, /* Handle for sqlite3DbMallocZero() (may be null) */ + int op, /* Expression opcode */ + const char *zToken /* Token argument. Might be NULL */ +){ + Token x; + x.z = zToken; + x.n = zToken ? sqlite3Strlen30(zToken) : 0; + return sqlite3ExprAlloc(db, op, &x, 0); +} + +/* +** Attach subtrees pLeft and pRight to the Expr node pRoot. +** +** If pRoot==NULL that means that a memory allocation error has occurred. +** In that case, delete the subtrees pLeft and pRight. +*/ +void sqlite3ExprAttachSubtrees( + sqlite3 *db, + Expr *pRoot, + Expr *pLeft, + Expr *pRight +){ + if( pRoot==0 ){ + assert( db->mallocFailed ); + sqlite3ExprDelete(db, pLeft); + sqlite3ExprDelete(db, pRight); + }else{ + if( pRight ){ + pRoot->pRight = pRight; + if( pRight->flags & EP_ExpCollate ){ + pRoot->flags |= EP_ExpCollate; + pRoot->pColl = pRight->pColl; + } + } + if( pLeft ){ + pRoot->pLeft = pLeft; + if( pLeft->flags & EP_ExpCollate ){ + pRoot->flags |= EP_ExpCollate; + pRoot->pColl = pLeft->pColl; + } + } + exprSetHeight(pRoot); + } +} + +/* +** Allocate a Expr node which joins as many as two subtrees. +** +** One or both of the subtrees can be NULL. Return a pointer to the new +** Expr node. Or, if an OOM error occurs, set pParse->db->mallocFailed, +** free the subtrees and return NULL. +*/ +Expr *sqlite3PExpr( + Parse *pParse, /* Parsing context */ + int op, /* Expression opcode */ + Expr *pLeft, /* Left operand */ + Expr *pRight, /* Right operand */ + const Token *pToken /* Argument token */ +){ + Expr *p = sqlite3ExprAlloc(pParse->db, op, pToken, 1); + sqlite3ExprAttachSubtrees(pParse->db, p, pLeft, pRight); + if( p ) { + sqlite3ExprCheckHeight(pParse, p->nHeight); + } + return p; +} + +/* +** Join two expressions using an AND operator. If either expression is +** NULL, then just return the other expression. +*/ +Expr *sqlite3ExprAnd(sqlite3 *db, Expr *pLeft, Expr *pRight){ + if( pLeft==0 ){ + return pRight; + }else if( pRight==0 ){ + return pLeft; + }else{ + Expr *pNew = sqlite3ExprAlloc(db, TK_AND, 0, 0); + sqlite3ExprAttachSubtrees(db, pNew, pLeft, pRight); + return pNew; + } +} + +/* +** Construct a new expression node for a function with multiple +** arguments. +*/ +Expr *sqlite3ExprFunction(Parse *pParse, ExprList *pList, Token *pToken){ + Expr *pNew; + sqlite3 *db = pParse->db; + assert( pToken ); + pNew = sqlite3ExprAlloc(db, TK_FUNCTION, pToken, 1); + if( pNew==0 ){ + sqlite3ExprListDelete(db, pList); /* Avoid memory leak when malloc fails */ + return 0; + } + pNew->x.pList = pList; + assert( !ExprHasProperty(pNew, EP_xIsSelect) ); + sqlite3ExprSetHeight(pParse, pNew); + return pNew; +} + +/* +** Assign a variable number to an expression that encodes a wildcard +** in the original SQL statement. +** +** Wildcards consisting of a single "?" are assigned the next sequential +** variable number. +** +** Wildcards of the form "?nnn" are assigned the number "nnn". We make +** sure "nnn" is not too be to avoid a denial of service attack when +** the SQL statement comes from an external source. +** +** Wildcards of the form ":aaa", "@aaa", or "$aaa" are assigned the same number +** as the previous instance of the same wildcard. Or if this is the first +** instance of the wildcard, the next sequenial variable number is +** assigned. +*/ +void sqlite3ExprAssignVarNumber(Parse *pParse, Expr *pExpr){ + sqlite3 *db = pParse->db; + const char *z; + + if( pExpr==0 ) return; + assert( !ExprHasAnyProperty(pExpr, EP_IntValue|EP_Reduced|EP_TokenOnly) ); + z = pExpr->u.zToken; + assert( z!=0 ); + assert( z[0]!=0 ); + if( z[1]==0 ){ + /* Wildcard of the form "?". Assign the next variable number */ + assert( z[0]=='?' ); + pExpr->iColumn = (ynVar)(++pParse->nVar); + }else{ + ynVar x = 0; + u32 n = sqlite3Strlen30(z); + if( z[0]=='?' ){ + /* Wildcard of the form "?nnn". Convert "nnn" to an integer and + ** use it as the variable number */ + i64 i; + int bOk = 0==sqlite3Atoi64(&z[1], &i, n-1, SQLITE_UTF8); + pExpr->iColumn = x = (ynVar)i; + testcase( i==0 ); + testcase( i==1 ); + testcase( i==db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER]-1 ); + testcase( i==db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER] ); + if( bOk==0 || i<1 || i>db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER] ){ + sqlite3ErrorMsg(pParse, "variable number must be between ?1 and ?%d", + db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER]); + x = 0; + } + if( i>pParse->nVar ){ + pParse->nVar = (int)i; + } + }else{ + /* Wildcards like ":aaa", "$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] && memcmp(pParse->azVar[i],z,n+1)==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( !ExprHasAnyProperty(p, EP_TokenOnly) ){ + sqlite3ExprDelete(db, p->pLeft); + sqlite3ExprDelete(db, p->pRight); + if( !ExprHasProperty(p, EP_Reduced) && (p->flags2 & EP2_MallocedToken)!=0 ){ + sqlite3DbFree(db, p->u.zToken); + } + if( ExprHasProperty(p, EP_xIsSelect) ){ + sqlite3SelectDelete(db, p->x.pSelect); + }else{ + sqlite3ExprListDelete(db, p->x.pList); + } + } + if( !ExprHasProperty(p, EP_Static) ){ + sqlite3DbFree(db, p); + } +} + +/* +** Return the number of bytes allocated for the expression structure +** passed as the first argument. This is always one of EXPR_FULLSIZE, +** EXPR_REDUCEDSIZE or EXPR_TOKENONLYSIZE. +*/ +static int exprStructSize(Expr *p){ + if( ExprHasProperty(p, EP_TokenOnly) ) return EXPR_TOKENONLYSIZE; + if( ExprHasProperty(p, EP_Reduced) ) return EXPR_REDUCEDSIZE; + return EXPR_FULLSIZE; +} + +/* +** The dupedExpr*Size() routines each return the number of bytes required +** to store a copy of an expression or expression tree. They differ in +** how much of the tree is measured. +** +** dupedExprStructSize() Size of only the Expr structure +** dupedExprNodeSize() Size of Expr + space for token +** dupedExprSize() Expr + token + subtree components +** +*************************************************************************** +** +** The dupedExprStructSize() function returns two values OR-ed together: +** (1) the space required for a copy of the Expr structure only and +** (2) the EP_xxx flags that indicate what the structure size should be. +** The return values is always one of: +** +** EXPR_FULLSIZE +** EXPR_REDUCEDSIZE | EP_Reduced +** EXPR_TOKENONLYSIZE | EP_TokenOnly +** +** The size of the structure can be found by masking the return value +** of this routine with 0xfff. The flags can be found by masking the +** return value with EP_Reduced|EP_TokenOnly. +** +** Note that with flags==EXPRDUP_REDUCE, this routines works on full-size +** (unreduced) Expr objects as they or originally constructed by the parser. +** During expression analysis, extra information is computed and moved into +** later parts of teh Expr object and that extra information might get chopped +** off if the expression is reduced. Note also that it does not work to +** make a EXPRDUP_REDUCE copy of a reduced expression. It is only legal +** to reduce a pristine expression tree from the parser. The implementation +** of dupedExprStructSize() contain multiple assert() statements that attempt +** to enforce this constraint. +*/ +static int dupedExprStructSize(Expr *p, int flags){ + int nSize; + assert( flags==EXPRDUP_REDUCE || flags==0 ); /* Only one flag value allowed */ + if( 0==(flags&EXPRDUP_REDUCE) ){ + nSize = EXPR_FULLSIZE; + }else{ + assert( !ExprHasAnyProperty(p, EP_TokenOnly|EP_Reduced) ); + assert( !ExprHasProperty(p, EP_FromJoin) ); + assert( (p->flags2 & EP2_MallocedToken)==0 ); + assert( (p->flags2 & EP2_Irreducible)==0 ); + if( p->pLeft || p->pRight || p->pColl || p->x.pList ){ + nSize = EXPR_REDUCEDSIZE | EP_Reduced; + }else{ + nSize = EXPR_TOKENONLYSIZE | EP_TokenOnly; + } + } + return nSize; +} + +/* +** This function returns the space in bytes required to store the copy +** of the Expr structure and a copy of the Expr.u.zToken string (if that +** string is defined.) +*/ +static int dupedExprNodeSize(Expr *p, int flags){ + int nByte = dupedExprStructSize(p, flags) & 0xfff; + if( !ExprHasProperty(p, EP_IntValue) && p->u.zToken ){ + nByte += sqlite3Strlen30(p->u.zToken)+1; + } + return ROUND8(nByte); +} + +/* +** Return the number of bytes required to create a duplicate of the +** expression passed as the first argument. The second argument is a +** mask containing EXPRDUP_XXX flags. +** +** The value returned includes space to create a copy of the Expr struct +** itself and the buffer referred to by Expr.u.zToken, if any. +** +** If the EXPRDUP_REDUCE flag is set, then the return value includes +** space to duplicate all Expr nodes in the tree formed by Expr.pLeft +** and Expr.pRight variables (but not for any structures pointed to or +** descended from the Expr.x.pList or Expr.x.pSelect variables). +*/ +static int dupedExprSize(Expr *p, int flags){ + int nByte = 0; + if( p ){ + nByte = dupedExprNodeSize(p, flags); + if( flags&EXPRDUP_REDUCE ){ + nByte += dupedExprSize(p->pLeft, flags) + dupedExprSize(p->pRight, flags); + } + } + return nByte; +} + +/* +** This function is similar to sqlite3ExprDup(), except that if pzBuffer +** is not NULL then *pzBuffer is assumed to point to a buffer large enough +** to store the copy of expression p, the copies of p->u.zToken +** (if applicable), and the copies of the p->pLeft and p->pRight expressions, +** if any. Before returning, *pzBuffer is set to the first byte passed the +** portion of the buffer copied into by this function. +*/ +static Expr *exprDup(sqlite3 *db, Expr *p, int flags, u8 **pzBuffer){ + Expr *pNew = 0; /* Value to return */ + if( p ){ + const int isReduced = (flags&EXPRDUP_REDUCE); + u8 *zAlloc; + u32 staticFlag = 0; + + assert( pzBuffer==0 || isReduced ); + + /* Figure out where to write the new Expr structure. */ + if( pzBuffer ){ + zAlloc = *pzBuffer; + staticFlag = EP_Static; + }else{ + zAlloc = sqlite3DbMallocRaw(db, dupedExprSize(p, flags)); + } + pNew = (Expr *)zAlloc; + + if( pNew ){ + /* Set nNewSize to the size allocated for the structure pointed to + ** by pNew. This is either EXPR_FULLSIZE, EXPR_REDUCEDSIZE or + ** EXPR_TOKENONLYSIZE. nToken is set to the number of bytes consumed + ** by the copy of the p->u.zToken string (if any). + */ + const unsigned nStructSize = dupedExprStructSize(p, flags); + const int nNewSize = nStructSize & 0xfff; + int nToken; + if( !ExprHasProperty(p, EP_IntValue) && p->u.zToken ){ + nToken = sqlite3Strlen30(p->u.zToken) + 1; + }else{ + nToken = 0; + } + if( isReduced ){ + assert( ExprHasProperty(p, EP_Reduced)==0 ); + memcpy(zAlloc, p, nNewSize); + }else{ + int nSize = exprStructSize(p); + memcpy(zAlloc, p, nSize); + memset(&zAlloc[nSize], 0, EXPR_FULLSIZE-nSize); + } + + /* Set the EP_Reduced, EP_TokenOnly, and EP_Static flags appropriately. */ + pNew->flags &= ~(EP_Reduced|EP_TokenOnly|EP_Static); + 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( ExprHasAnyProperty(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{ + pNew->flags2 = 0; + if( !ExprHasAnyProperty(p, EP_TokenOnly) ){ + pNew->pLeft = sqlite3ExprDup(db, p->pLeft, 0); + pNew->pRight = sqlite3ExprDup(db, p->pRight, 0); + } + } + + } + } + return pNew; +} + +/* +** The following group of routines make deep copies of expressions, +** expression lists, ID lists, and select statements. The copies can +** be deleted (by being passed to their respective ...Delete() routines) +** without effecting the originals. +** +** The expression list, ID, and source lists return by sqlite3ExprListDup(), +** sqlite3IdListDup(), and sqlite3SrcListDup() can not be further expanded +** by subsequent calls to sqlite*ListAppend() routines. +** +** Any tables that the SrcList might point to are not duplicated. +** +** The flags parameter contains a combination of the EXPRDUP_XXX flags. +** If the EXPRDUP_REDUCE flag is set, then the structure returned is a +** truncated version of the usual Expr structure that will be stored as +** part of the in-memory representation of the database schema. +*/ +Expr *sqlite3ExprDup(sqlite3 *db, Expr *p, int flags){ + return exprDup(db, p, flags, 0); +} +ExprList *sqlite3ExprListDup(sqlite3 *db, ExprList *p, int flags){ + ExprList *pNew; + struct ExprList_item *pItem, *pOldItem; + int i; + if( p==0 ) return 0; + pNew = sqlite3DbMallocRaw(db, sizeof(*pNew) ); + if( pNew==0 ) return 0; + pNew->iECursor = 0; + pNew->nExpr = pNew->nAlloc = p->nExpr; + pNew->a = pItem = sqlite3DbMallocRaw(db, p->nExpr*sizeof(p->a[0]) ); + if( pItem==0 ){ + sqlite3DbFree(db, pNew); + return 0; + } + pOldItem = p->a; + for(i=0; i<p->nExpr; i++, pItem++, pOldItem++){ + Expr *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->iCol = pOldItem->iCol; + pItem->iAlias = pOldItem->iAlias; + } + return pNew; +} + +/* +** If cursors, triggers, views and subqueries are all omitted from +** the build, then none of the following routines, except for +** sqlite3SelectDup(), can be called. sqlite3SelectDup() is sometimes +** called with a NULL argument. +*/ +#if !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_TRIGGER) \ + || !defined(SQLITE_OMIT_SUBQUERY) +SrcList *sqlite3SrcListDup(sqlite3 *db, SrcList *p, int flags){ + SrcList *pNew; + int i; + int nByte; + if( p==0 ) return 0; + nByte = sizeof(*p) + (p->nSrc>0 ? sizeof(p->a[0]) * (p->nSrc-1) : 0); + pNew = sqlite3DbMallocRaw(db, nByte ); + if( pNew==0 ) return 0; + pNew->nSrc = pNew->nAlloc = p->nSrc; + for(i=0; i<p->nSrc; i++){ + struct SrcList_item *pNewItem = &pNew->a[i]; + struct SrcList_item *pOldItem = &p->a[i]; + Table *pTab; + pNewItem->zDatabase = sqlite3DbStrDup(db, pOldItem->zDatabase); + pNewItem->zName = sqlite3DbStrDup(db, pOldItem->zName); + pNewItem->zAlias = sqlite3DbStrDup(db, pOldItem->zAlias); + pNewItem->jointype = pOldItem->jointype; + pNewItem->iCursor = pOldItem->iCursor; + pNewItem->addrFillSub = pOldItem->addrFillSub; + pNewItem->regReturn = pOldItem->regReturn; + pNewItem->isCorrelated = pOldItem->isCorrelated; + pNewItem->zIndex = sqlite3DbStrDup(db, pOldItem->zIndex); + pNewItem->notIndexed = pOldItem->notIndexed; + pNewItem->pIndex = pOldItem->pIndex; + pTab = pNewItem->pTab = pOldItem->pTab; + if( pTab ){ + pTab->nRef++; + } + pNewItem->pSelect = sqlite3SelectDup(db, pOldItem->pSelect, flags); + pNewItem->pOn = sqlite3ExprDup(db, pOldItem->pOn, flags); + pNewItem->pUsing = sqlite3IdListDup(db, pOldItem->pUsing); + pNewItem->colUsed = pOldItem->colUsed; + } + return pNew; +} +IdList *sqlite3IdListDup(sqlite3 *db, IdList *p){ + IdList *pNew; + int i; + if( p==0 ) return 0; + pNew = sqlite3DbMallocRaw(db, sizeof(*pNew) ); + if( pNew==0 ) return 0; + pNew->nId = pNew->nAlloc = p->nId; + pNew->a = sqlite3DbMallocRaw(db, p->nId*sizeof(p->a[0]) ); + if( pNew->a==0 ){ + sqlite3DbFree(db, pNew); + return 0; + } + for(i=0; i<p->nId; i++){ + struct IdList_item *pNewItem = &pNew->a[i]; + struct IdList_item *pOldItem = &p->a[i]; + pNewItem->zName = sqlite3DbStrDup(db, pOldItem->zName); + pNewItem->idx = pOldItem->idx; + } + return pNew; +} +Select *sqlite3SelectDup(sqlite3 *db, Select *p, int flags){ + Select *pNew; + 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 = sqlite3SelectDup(db, p->pPrior, flags); + pNew->pLimit = sqlite3ExprDup(db, p->pLimit, flags); + pNew->pOffset = sqlite3ExprDup(db, p->pOffset, flags); + pNew->iLimit = 0; + pNew->iOffset = 0; + pNew->selFlags = p->selFlags & ~SF_UsesEphemeral; + pNew->pRightmost = 0; + pNew->addrOpenEphm[0] = -1; + pNew->addrOpenEphm[1] = -1; + pNew->addrOpenEphm[2] = -1; + return pNew; +} +#else +Select *sqlite3SelectDup(sqlite3 *db, Select *p, int flags){ + assert( p==0 ); + return 0; +} +#endif + + +/* +** Add a new element to the end of an expression list. If pList is +** initially NULL, then create a new expression list. +** +** If a memory allocation error occurs, the entire list is freed and +** NULL is returned. If non-NULL is returned, then it is guaranteed +** that the new entry was successfully appended. +*/ +ExprList *sqlite3ExprListAppend( + Parse *pParse, /* Parsing context */ + ExprList *pList, /* List to which to append. Might be NULL */ + Expr *pExpr /* Expression to be appended. Might be NULL */ +){ + sqlite3 *db = pParse->db; + if( pList==0 ){ + pList = sqlite3DbMallocZero(db, sizeof(ExprList) ); + if( pList==0 ){ + goto no_mem; + } + assert( pList->nAlloc==0 ); + } + if( pList->nAlloc<=pList->nExpr ){ + struct ExprList_item *a; + int n = pList->nAlloc*2 + 4; + a = sqlite3DbRealloc(db, pList->a, n*sizeof(pList->a[0])); + if( a==0 ){ + goto no_mem; + } + pList->a = a; + pList->nAlloc = sqlite3DbMallocSize(db, a)/sizeof(a[0]); + } + assert( pList->a!=0 ); + if( 1 ){ + struct ExprList_item *pItem = &pList->a[pList->nExpr++]; + memset(pItem, 0, sizeof(*pItem)); + pItem->pExpr = pExpr; + } + return pList; + +no_mem: + /* Avoid leaking memory if malloc has failed. */ + sqlite3ExprDelete(db, pExpr); + sqlite3ExprListDelete(db, pList); + return 0; +} + +/* +** Set the ExprList.a[].zName element of the most recently added item +** on the expression list. +** +** pList might be NULL following an OOM error. But pName should never be +** NULL. If a memory allocation fails, the pParse->db->mallocFailed flag +** is set. +*/ +void sqlite3ExprListSetName( + Parse *pParse, /* Parsing context */ + ExprList *pList, /* List to which to add the span. */ + Token *pName, /* Name to be added */ + int dequote /* True to cause the name to be dequoted */ +){ + assert( pList!=0 || pParse->db->mallocFailed!=0 ); + if( pList ){ + struct ExprList_item *pItem; + assert( pList->nExpr>0 ); + pItem = &pList->a[pList->nExpr-1]; + assert( pItem->zName==0 ); + pItem->zName = sqlite3DbStrNDup(pParse->db, pName->z, pName->n); + if( dequote && pItem->zName ) sqlite3Dequote(pItem->zName); + } +} + +/* +** Set the ExprList.a[].zSpan element of the most recently added item +** on the expression list. +** +** pList might be NULL following an OOM error. But pSpan should never be +** NULL. If a memory allocation fails, the pParse->db->mallocFailed flag +** is set. +*/ +void sqlite3ExprListSetSpan( + Parse *pParse, /* Parsing context */ + ExprList *pList, /* List to which to add the span. */ + ExprSpan *pSpan /* The span to be added */ +){ + sqlite3 *db = pParse->db; + assert( pList!=0 || db->mallocFailed!=0 ); + if( pList ){ + struct ExprList_item *pItem = &pList->a[pList->nExpr-1]; + assert( pList->nExpr>0 ); + assert( db->mallocFailed || pItem->pExpr==pSpan->pExpr ); + sqlite3DbFree(db, pItem->zSpan); + pItem->zSpan = sqlite3DbStrNDup(db, (char*)pSpan->zStart, + (int)(pSpan->zEnd - pSpan->zStart)); + } +} + +/* +** If the expression list pEList contains more than iLimit elements, +** leave an error message in pParse. +*/ +void sqlite3ExprListCheckLength( + Parse *pParse, + ExprList *pEList, + const char *zObject +){ + int mx = pParse->db->aLimit[SQLITE_LIMIT_COLUMN]; + testcase( pEList && pEList->nExpr==mx ); + testcase( pEList && pEList->nExpr==mx+1 ); + if( pEList && pEList->nExpr>mx ){ + sqlite3ErrorMsg(pParse, "too many columns in %s", zObject); + } +} + +/* +** Delete an entire expression list. +*/ +void sqlite3ExprListDelete(sqlite3 *db, ExprList *pList){ + int i; + struct ExprList_item *pItem; + if( pList==0 ) return; + assert( pList->a!=0 || (pList->nExpr==0 && pList->nAlloc==0) ); + assert( pList->nExpr<=pList->nAlloc ); + for(pItem=pList->a, i=0; i<pList->nExpr; i++, pItem++){ + sqlite3ExprDelete(db, pItem->pExpr); + sqlite3DbFree(db, pItem->zName); + sqlite3DbFree(db, pItem->zSpan); + } + sqlite3DbFree(db, pList->a); + sqlite3DbFree(db, pList); +} + +/* +** These routines are Walker callbacks. Walker.u.pi is a pointer +** to an integer. These routines are checking an expression to see +** if it is a constant. Set *Walker.u.pi to 0 if the expression is +** not constant. +** +** These callback routines are used to implement the following: +** +** sqlite3ExprIsConstant() +** sqlite3ExprIsConstantNotJoin() +** sqlite3ExprIsConstantOrFunction() +** +*/ +static int exprNodeIsConstant(Walker *pWalker, Expr *pExpr){ + + /* If pWalker->u.i is 3 then any term of the expression that comes from + ** the ON or USING clauses of a join disqualifies the expression + ** from being considered constant. */ + if( pWalker->u.i==3 && ExprHasAnyProperty(pExpr, EP_FromJoin) ){ + pWalker->u.i = 0; + return WRC_Abort; + } + + switch( pExpr->op ){ + /* Consider functions to be constant if all their arguments are constant + ** and pWalker->u.i==2 */ + case TK_FUNCTION: + if( pWalker->u.i==2 ) return 0; + /* Fall through */ + case TK_ID: + case TK_COLUMN: + case TK_AGG_FUNCTION: + case TK_AGG_COLUMN: + testcase( pExpr->op==TK_ID ); + testcase( pExpr->op==TK_COLUMN ); + testcase( pExpr->op==TK_AGG_FUNCTION ); + testcase( pExpr->op==TK_AGG_COLUMN ); + pWalker->u.i = 0; + return WRC_Abort; + default: + testcase( pExpr->op==TK_SELECT ); /* selectNodeIsConstant will disallow */ + testcase( pExpr->op==TK_EXISTS ); /* selectNodeIsConstant will disallow */ + return WRC_Continue; + } +} +static int selectNodeIsConstant(Walker *pWalker, Select *NotUsed){ + UNUSED_PARAMETER(NotUsed); + pWalker->u.i = 0; + return WRC_Abort; +} +static int exprIsConst(Expr *p, int initFlag){ + Walker w; + w.u.i = initFlag; + w.xExprCallback = exprNodeIsConstant; + w.xSelectCallback = selectNodeIsConstant; + sqlite3WalkExpr(&w, p); + return w.u.i; +} + +/* +** Walk an expression tree. Return 1 if the expression is constant +** and 0 if it involves variables or function calls. +** +** For the purposes of this function, a double-quoted string (ex: "abc") +** is considered a variable but a single-quoted string (ex: 'abc') is +** a constant. +*/ +int sqlite3ExprIsConstant(Expr *p){ + return exprIsConst(p, 1); +} + +/* +** Walk an expression tree. Return 1 if the expression is constant +** that does no originate from the ON or USING clauses of a join. +** Return 0 if it involves variables or function calls or terms from +** an ON or USING clause. +*/ +int sqlite3ExprIsConstantNotJoin(Expr *p){ + return exprIsConst(p, 3); +} + +/* +** Walk an expression tree. Return 1 if the expression is constant +** or a function call with constant arguments. Return and 0 if there +** are any variables. +** +** For the purposes of this function, a double-quoted string (ex: "abc") +** is considered a variable but a single-quoted string (ex: 'abc') is +** a constant. +*/ +int sqlite3ExprIsConstantOrFunction(Expr *p){ + return exprIsConst(p, 2); +} + +/* +** If the expression p codes a constant integer that is small enough +** to fit in a 32-bit integer, return 1 and put the value of the integer +** in *pValue. If the expression is not an integer or if it is too big +** to fit in a signed 32-bit integer, return 0 and leave *pValue unchanged. +*/ +int sqlite3ExprIsInteger(Expr *p, int *pValue){ + int rc = 0; + + /* If an expression is an integer literal that fits in a signed 32-bit + ** integer, then the EP_IntValue flag will have already been set */ + assert( p->op!=TK_INTEGER || (p->flags & EP_IntValue)!=0 + || sqlite3GetInt32(p->u.zToken, &rc)==0 ); + + if( p->flags & EP_IntValue ){ + *pValue = p->u.iValue; + return 1; + } + switch( p->op ){ + case TK_UPLUS: { + rc = sqlite3ExprIsInteger(p->pLeft, pValue); + break; + } + case TK_UMINUS: { + int v; + if( sqlite3ExprIsInteger(p->pLeft, &v) ){ + *pValue = -v; + rc = 1; + } + break; + } + default: break; + } + return rc; +} + +/* +** Return FALSE if there is no chance that the expression can be NULL. +** +** If the expression might be NULL or if the expression is too complex +** to tell return TRUE. +** +** This routine is used as an optimization, to skip OP_IsNull opcodes +** when we know that a value cannot be NULL. Hence, a false positive +** (returning TRUE when in fact the expression can never be NULL) might +** be a small performance hit but is otherwise harmless. On the other +** hand, a false negative (returning FALSE when the result could be NULL) +** will likely result in an incorrect answer. So when in doubt, return +** TRUE. +*/ +int sqlite3ExprCanBeNull(const Expr *p){ + u8 op; + while( p->op==TK_UPLUS || p->op==TK_UMINUS ){ p = p->pLeft; } + op = p->op; + if( op==TK_REGISTER ) op = p->op2; + switch( op ){ + case TK_INTEGER: + case TK_STRING: + case TK_FLOAT: + case TK_BLOB: + return 0; + default: + return 1; + } +} + +/* +** Generate an OP_IsNull instruction that tests register iReg and jumps +** to location iDest if the value in iReg is NULL. The value in iReg +** was computed by pExpr. If we can look at pExpr at compile-time and +** determine that it can never generate a NULL, then the OP_IsNull operation +** can be omitted. +*/ +void sqlite3ExprCodeIsNullJump( + Vdbe *v, /* The VDBE under construction */ + const Expr *pExpr, /* Only generate OP_IsNull if this expr can be NULL */ + int iReg, /* Test the value in this register for NULL */ + int iDest /* Jump here if the value is null */ +){ + if( sqlite3ExprCanBeNull(pExpr) ){ + sqlite3VdbeAddOp2(v, OP_IsNull, iReg, iDest); + } +} + +/* +** Return TRUE if the given expression is a constant which would be +** unchanged by OP_Affinity with the affinity given in the second +** argument. +** +** This routine is used to determine if the OP_Affinity operation +** can be omitted. When in doubt return FALSE. A false negative +** is harmless. A false positive, however, can result in the wrong +** answer. +*/ +int sqlite3ExprNeedsNoAffinityChange(const Expr *p, char aff){ + u8 op; + if( aff==SQLITE_AFF_NONE ) return 1; + while( p->op==TK_UPLUS || p->op==TK_UMINUS ){ p = p->pLeft; } + op = p->op; + if( op==TK_REGISTER ) op = p->op2; + switch( op ){ + case TK_INTEGER: { + return aff==SQLITE_AFF_INTEGER || aff==SQLITE_AFF_NUMERIC; + } + case TK_FLOAT: { + return aff==SQLITE_AFF_REAL || aff==SQLITE_AFF_NUMERIC; + } + case TK_STRING: { + return aff==SQLITE_AFF_TEXT; + } + case TK_BLOB: { + return 1; + } + case TK_COLUMN: { + assert( p->iTable>=0 ); /* p cannot be part of a CHECK constraint */ + return p->iColumn<0 + && (aff==SQLITE_AFF_INTEGER || aff==SQLITE_AFF_NUMERIC); + } + default: { + return 0; + } + } +} + +/* +** Return TRUE if the given string is a row-id column name. +*/ +int sqlite3IsRowid(const char *z){ + if( sqlite3StrICmp(z, "_ROWID_")==0 ) return 1; + if( sqlite3StrICmp(z, "ROWID")==0 ) return 1; + if( sqlite3StrICmp(z, "OID")==0 ) return 1; + return 0; +} + +/* +** Return true if we are able to the IN operator optimization on a +** query of the form +** +** x IN (SELECT ...) +** +** Where the SELECT... clause is as specified by the parameter to this +** routine. +** +** The Select object passed in has already been preprocessed and no +** errors have been found. +*/ +#ifndef SQLITE_OMIT_SUBQUERY +static int isCandidateForInOpt(Select *p){ + SrcList *pSrc; + ExprList *pEList; + Table *pTab; + if( p==0 ) return 0; /* right-hand side of IN is SELECT */ + if( p->pPrior ) return 0; /* Not a compound SELECT */ + if( p->selFlags & (SF_Distinct|SF_Aggregate) ){ + testcase( (p->selFlags & (SF_Distinct|SF_Aggregate))==SF_Distinct ); + testcase( (p->selFlags & (SF_Distinct|SF_Aggregate))==SF_Aggregate ); + return 0; /* No DISTINCT keyword and no aggregate functions */ + } + assert( p->pGroupBy==0 ); /* Has no GROUP BY clause */ + if( p->pLimit ) return 0; /* Has no LIMIT clause */ + assert( p->pOffset==0 ); /* No LIMIT means no OFFSET */ + if( p->pWhere ) return 0; /* Has no WHERE clause */ + pSrc = p->pSrc; + assert( pSrc!=0 ); + if( pSrc->nSrc!=1 ) return 0; /* Single term in FROM clause */ + if( pSrc->a[0].pSelect ) return 0; /* FROM is not a subquery or view */ + pTab = pSrc->a[0].pTab; + if( NEVER(pTab==0) ) return 0; + assert( pTab->pSelect==0 ); /* FROM clause is not a view */ + if( IsVirtual(pTab) ) return 0; /* FROM clause not a virtual table */ + pEList = p->pEList; + if( pEList->nExpr!=1 ) return 0; /* One column in the result set */ + if( pEList->a[0].pExpr->op!=TK_COLUMN ) return 0; /* Result is a column */ + return 1; +} +#endif /* SQLITE_OMIT_SUBQUERY */ + +/* +** This function is used by the implementation of the IN (...) operator. +** It's job is to find or create a b-tree structure that may be used +** either to test for membership of the (...) set or to iterate through +** its members, skipping duplicates. +** +** The index of the cursor opened on the b-tree (database table, database index +** or ephermal table) is stored in pX->iTable before this function returns. +** 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 - The cursor was opened on a database index. +** IN_INDEX_EPH - The cursor was opened on a specially created and +** populated epheremal table. +** +** An existing b-tree may only be used if the SELECT is of the simple +** form: +** +** SELECT <column> FROM <table> +** +** If the prNotFound parameter is 0, then the b-tree will be used to iterate +** through the set members, skipping any duplicates. In this case an +** epheremal table must be used unless the selected <column> is guaranteed +** to be unique - either because it is an INTEGER PRIMARY KEY or it +** has a UNIQUE constraint or UNIQUE index. +** +** If the prNotFound parameter is not 0, then the b-tree will be used +** for fast set membership tests. In this case an epheremal table must +** be used unless <column> is an INTEGER PRIMARY KEY or an index can +** be found with <column> as its left-most column. +** +** When the b-tree is being used for membership tests, the calling function +** needs to know whether or not the structure contains an SQL NULL +** value in order to correctly evaluate expressions like "X IN (Y, Z)". +** If there is any chance that the (...) might contain a NULL value at +** runtime, then a register is allocated and the register number written +** to *prNotFound. If there is no chance that the (...) contains a +** NULL value, then *prNotFound is left unchanged. +** +** If a register is allocated and its location stored in *prNotFound, then +** its initial value is NULL. If the (...) does not remain constant +** for the duration of the query (i.e. the SELECT within the (...) +** is a correlated subquery) then the value of the allocated register is +** reset to NULL each time the subquery is rerun. This allows the +** caller to use vdbe code equivalent to the following: +** +** if( register==NULL ){ +** has_null = <test if data structure contains null> +** register = 1 +** } +** +** in order to avoid running the <test if data structure contains null> +** test more often than is necessary. +*/ +#ifndef SQLITE_OMIT_SUBQUERY +int sqlite3FindInIndex(Parse *pParse, Expr *pX, int *prNotFound){ + Select *p; /* SELECT to the right of IN operator */ + int eType = 0; /* Type of RHS table. IN_INDEX_* */ + int iTab = pParse->nTab++; /* Cursor of the RHS table */ + int mustBeUnique = (prNotFound==0); /* True if RHS must be unique */ + + assert( pX->op==TK_IN ); + + /* Check to see if an existing table or index can be used to + ** satisfy the query. This is preferable to generating a new + ** ephemeral table. + */ + p = (ExprHasProperty(pX, EP_xIsSelect) ? pX->x.pSelect : 0); + if( ALWAYS(pParse->nErr==0) && isCandidateForInOpt(p) ){ + sqlite3 *db = pParse->db; /* Database connection */ + Vdbe *v = sqlite3GetVdbe(pParse); /* Virtual machine being coded */ + Table *pTab; /* Table <table>. */ + Expr *pExpr; /* Expression <column> */ + int iCol; /* Index of column <column> */ + int iDb; /* Database idx for pTab */ + + assert( p ); /* Because of isCandidateForInOpt(p) */ + assert( p->pEList!=0 ); /* Because of isCandidateForInOpt(p) */ + assert( p->pEList->a[0].pExpr!=0 ); /* Because of isCandidateForInOpt(p) */ + assert( p->pSrc!=0 ); /* Because of isCandidateForInOpt(p) */ + pTab = p->pSrc->a[0].pTab; + pExpr = p->pEList->a[0].pExpr; + iCol = pExpr->iColumn; + + /* Code an OP_VerifyCookie and OP_TableLock for <table>. */ + iDb = sqlite3SchemaToIndex(db, pTab->pSchema); + sqlite3CodeVerifySchema(pParse, iDb); + sqlite3TableLock(pParse, iDb, pTab->tnum, 0, pTab->zName); + + /* This function is only called from two places. In both cases the vdbe + ** has already been allocated. So assume sqlite3GetVdbe() is always + ** successful here. + */ + assert(v); + if( iCol<0 ){ + int iMem = ++pParse->nMem; + int iAddr; + + iAddr = sqlite3VdbeAddOp1(v, OP_Once, iMem); + + 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. + */ + char aff = comparisonAffinity(pX); + int affinity_ok = (pTab->aCol[iCol].affinity==aff||aff==SQLITE_AFF_NONE); + + for(pIdx=pTab->pIndex; pIdx && eType==0 && affinity_ok; pIdx=pIdx->pNext){ + if( (pIdx->aiColumn[0]==iCol) + && sqlite3FindCollSeq(db, ENC(db), pIdx->azColl[0], 0)==pReq + && (!mustBeUnique || (pIdx->nColumn==1 && pIdx->onError!=OE_None)) + ){ + int iMem = ++pParse->nMem; + int iAddr; + char *pKey; + + pKey = (char *)sqlite3IndexKeyinfo(pParse, pIdx); + iAddr = sqlite3VdbeAddOp1(v, OP_Once, iMem); + + sqlite3VdbeAddOp4(v, OP_OpenRead, iTab, pIdx->tnum, iDb, + pKey,P4_KEYINFO_HANDOFF); + VdbeComment((v, "%s", pIdx->zName)); + eType = IN_INDEX_INDEX; + + sqlite3VdbeJumpHere(v, iAddr); + if( prNotFound && !pTab->aCol[iCol].notNull ){ + *prNotFound = ++pParse->nMem; + } + } + } + } + } + + if( eType==0 ){ + /* Could not found an existing table or index to use as the RHS b-tree. + ** We will have to generate an ephemeral table to do the job. + */ + double savedNQueryLoop = pParse->nQueryLoop; + int rMayHaveNull = 0; + eType = IN_INDEX_EPH; + if( prNotFound ){ + *prNotFound = rMayHaveNull = ++pParse->nMem; + }else{ + testcase( pParse->nQueryLoop>(double)1 ); + pParse->nQueryLoop = (double)1; + if( pX->pLeft->iColumn<0 && !ExprHasAnyProperty(pX, EP_xIsSelect) ){ + eType = IN_INDEX_ROWID; + } + } + sqlite3CodeSubselect(pParse, pX, rMayHaveNull, eType==IN_INDEX_ROWID); + pParse->nQueryLoop = savedNQueryLoop; + }else{ + pX->iTable = iTab; + } + return eType; +} +#endif + +/* +** Generate code for scalar subqueries used as a subquery expression, EXISTS, +** or IN operators. Examples: +** +** (SELECT a FROM b) -- subquery +** EXISTS (SELECT a FROM b) -- EXISTS subquery +** x IN (4,5,11) -- IN operator with list on right-hand side +** x IN (SELECT a FROM b) -- IN operator with subquery on the right +** +** The pExpr parameter describes the expression that contains the IN +** operator or subquery. +** +** If parameter isRowid is non-zero, then expression pExpr is guaranteed +** to be of the form "<rowid> IN (?, ?, ?)", where <rowid> is a reference +** to some integer key column of a table B-Tree. In this case, use an +** intkey B-Tree to store the set of IN(...) values instead of the usual +** (slower) variable length keys B-Tree. +** +** If rMayHaveNull is non-zero, that means that the operation is an IN +** (not a SELECT or EXISTS) and that the RHS might contains NULLs. +** Furthermore, the IN is in a WHERE clause and that we really want +** to iterate over the RHS of the IN operator in order to quickly locate +** all corresponding LHS elements. All this routine does is initialize +** the register given by rMayHaveNull to NULL. Calling routines will take +** care of changing this register value to non-NULL if the RHS is NULL-free. +** +** If rMayHaveNull is zero, that means that the subquery is being used +** for membership testing only. There is no need to initialize any +** registers to indicate the presense or absence of NULLs on the RHS. +** +** For a SELECT or EXISTS operator, return the register that holds the +** result. For IN operators or if an error occurs, the return value is 0. +*/ +#ifndef SQLITE_OMIT_SUBQUERY +int sqlite3CodeSubselect( + Parse *pParse, /* Parsing context */ + Expr *pExpr, /* The IN, SELECT, or EXISTS operator */ + int rMayHaveNull, /* Register that records whether NULLs exist in RHS */ + int isRowid /* If true, LHS of IN operator is a rowid */ +){ + int testAddr = -1; /* One-time test address */ + int rReg = 0; /* Register storing resulting */ + Vdbe *v = sqlite3GetVdbe(pParse); + if( NEVER(v==0) ) return 0; + sqlite3ExprCachePush(pParse); + + /* This code must be run in its entirety every time it is encountered + ** if any of the following is true: + ** + ** * The right-hand side is a correlated subquery + ** * The right-hand side is an expression list containing variables + ** * We are inside a trigger + ** + ** If all of the above are false, then we can run this code just once + ** save the results, and reuse the same result on subsequent invocations. + */ + if( !ExprHasAnyProperty(pExpr, EP_VarSelect) && !pParse->pTriggerTab ){ + int mem = ++pParse->nMem; + testAddr = sqlite3VdbeAddOp1(v, OP_Once, mem); + } + +#ifndef SQLITE_OMIT_EXPLAIN + if( pParse->explain==2 ){ + char *zMsg = sqlite3MPrintf( + pParse->db, "EXECUTE %s%s SUBQUERY %d", testAddr>=0?"":"CORRELATED ", + pExpr->op==TK_IN?"LIST":"SCALAR", pParse->iNextSelectId + ); + sqlite3VdbeAddOp4(v, OP_Explain, pParse->iSelectId, 0, 0, zMsg, P4_DYNAMIC); + } +#endif + + switch( pExpr->op ){ + case TK_IN: { + char affinity; /* Affinity of the LHS of the IN */ + KeyInfo keyInfo; /* Keyinfo for the generated table */ + int addr; /* Address of OP_OpenEphemeral instruction */ + Expr *pLeft = pExpr->pLeft; /* the LHS of the IN operator */ + + if( rMayHaveNull ){ + sqlite3VdbeAddOp2(v, OP_Null, 0, rMayHaveNull); + } + + affinity = sqlite3ExprAffinity(pLeft); + + /* Whether this is an 'x IN(SELECT...)' or an 'x IN(<exprlist>)' + ** expression it is handled the same way. An ephemeral table is + ** filled with single-field index keys representing the results + ** from the SELECT or the <exprlist>. + ** + ** If the 'x' expression is a column value, or the SELECT... + ** statement returns a column value, then the affinity of that + ** column is used to build the index keys. If both 'x' and the + ** SELECT... statement are columns, then numeric affinity is used + ** if either column has NUMERIC or INTEGER affinity. If neither + ** 'x' nor the SELECT... statement are columns, then numeric affinity + ** is used. + */ + pExpr->iTable = pParse->nTab++; + addr = sqlite3VdbeAddOp2(v, OP_OpenEphemeral, pExpr->iTable, !isRowid); + if( rMayHaveNull==0 ) sqlite3VdbeChangeP5(v, BTREE_UNORDERED); + memset(&keyInfo, 0, sizeof(keyInfo)); + keyInfo.nField = 1; + + if( ExprHasProperty(pExpr, EP_xIsSelect) ){ + /* Case 1: expr IN (SELECT ...) + ** + ** Generate code to write the results of the select into the temporary + ** table allocated and opened above. + */ + SelectDest dest; + ExprList *pEList; + + assert( !isRowid ); + sqlite3SelectDestInit(&dest, SRT_Set, pExpr->iTable); + dest.affinity = (u8)affinity; + assert( (pExpr->iTable&0x0000FFFF)==pExpr->iTable ); + pExpr->x.pSelect->iLimit = 0; + if( sqlite3Select(pParse, pExpr->x.pSelect, &dest) ){ + return 0; + } + pEList = pExpr->x.pSelect->pEList; + if( ALWAYS(pEList!=0 && pEList->nExpr>0) ){ + keyInfo.aColl[0] = sqlite3BinaryCompareCollSeq(pParse, pExpr->pLeft, + pEList->a[0].pExpr); + } + }else if( ALWAYS(pExpr->x.pList!=0) ){ + /* Case 2: expr IN (exprlist) + ** + ** For each expression, build an index key from the evaluation and + ** store it in the temporary table. If <expr> is a column, then use + ** that columns affinity when building index keys. If <expr> is not + ** a column, use numeric affinity. + */ + int i; + ExprList *pList = pExpr->x.pList; + struct ExprList_item *pItem; + int r1, r2, r3; + + if( !affinity ){ + affinity = SQLITE_AFF_NONE; + } + keyInfo.aColl[0] = sqlite3ExprCollSeq(pParse, pExpr->pLeft); + + /* Loop through each expression in <exprlist>. */ + r1 = sqlite3GetTempReg(pParse); + r2 = sqlite3GetTempReg(pParse); + sqlite3VdbeAddOp2(v, OP_Null, 0, r2); + for(i=pList->nExpr, pItem=pList->a; i>0; i--, pItem++){ + Expr *pE2 = pItem->pExpr; + int iValToIns; + + /* If the expression is not constant then we will need to + ** disable the test that was generated above that makes sure + ** this code only executes once. Because for a non-constant + ** expression we need to rerun this code each time. + */ + if( testAddr>=0 && !sqlite3ExprIsConstant(pE2) ){ + sqlite3VdbeChangeToNoop(v, testAddr); + testAddr = -1; + } + + /* Evaluate the expression and insert it into the temp table */ + if( isRowid && sqlite3ExprIsInteger(pE2, &iValToIns) ){ + sqlite3VdbeAddOp3(v, OP_InsertInt, pExpr->iTable, r2, iValToIns); + }else{ + r3 = sqlite3ExprCodeTarget(pParse, pE2, r1); + if( isRowid ){ + sqlite3VdbeAddOp2(v, OP_MustBeInt, r3, + sqlite3VdbeCurrentAddr(v)+2); + sqlite3VdbeAddOp3(v, OP_Insert, pExpr->iTable, r2, r3); + }else{ + sqlite3VdbeAddOp4(v, OP_MakeRecord, r3, 1, r2, &affinity, 1); + sqlite3ExprCacheAffinityChange(pParse, r3, 1); + sqlite3VdbeAddOp2(v, OP_IdxInsert, pExpr->iTable, r2); + } + } + } + sqlite3ReleaseTempReg(pParse, r1); + sqlite3ReleaseTempReg(pParse, r2); + } + if( !isRowid ){ + sqlite3VdbeChangeP4(v, addr, (void *)&keyInfo, 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; + sqlite3VdbeAddOp2(v, OP_Null, 0, dest.iParm); + VdbeComment((v, "Init subquery result")); + }else{ + dest.eDest = SRT_Exists; + sqlite3VdbeAddOp2(v, OP_Integer, 0, dest.iParm); + VdbeComment((v, "Init EXISTS result")); + } + sqlite3ExprDelete(pParse->db, pSel->pLimit); + pSel->pLimit = sqlite3PExpr(pParse, TK_INTEGER, 0, 0, + &sqlite3IntTokens[1]); + pSel->iLimit = 0; + if( sqlite3Select(pParse, pSel, &dest) ){ + return 0; + } + rReg = dest.iParm; + ExprSetIrreducible(pExpr); + break; + } + } + + if( testAddr>=0 ){ + sqlite3VdbeJumpHere(v, testAddr); + } + sqlite3ExprCachePop(pParse, 1); + + return rReg; +} +#endif /* SQLITE_OMIT_SUBQUERY */ + +#ifndef SQLITE_OMIT_SUBQUERY +/* +** Generate code for an IN expression. +** +** x IN (SELECT ...) +** x IN (value, value, ...) +** +** The left-hand side (LHS) is a scalar expression. The right-hand side (RHS) +** is an array of zero or more values. The expression is true if the LHS is +** contained within the RHS. The value of the expression is unknown (NULL) +** if the LHS is NULL or if the LHS is not contained within the RHS and the +** RHS contains one or more NULL values. +** +** This routine generates code will jump to destIfFalse if the LHS is not +** contained within the RHS. If due to NULLs we cannot determine if the LHS +** is contained in the RHS then jump to destIfNull. If the LHS is contained +** within the RHS then fall through. +*/ +static void sqlite3ExprCodeIN( + Parse *pParse, /* Parsing and code generating context */ + Expr *pExpr, /* The IN expression */ + int destIfFalse, /* Jump here if LHS is not contained in the RHS */ + int destIfNull /* Jump here if the results are unknown due to NULLs */ +){ + int rRhsHasNull = 0; /* Register that is true if RHS contains NULL values */ + char affinity; /* Comparison affinity to use */ + int eType; /* Type of the RHS */ + int r1; /* Temporary use register */ + Vdbe *v; /* Statement under construction */ + + /* Compute the RHS. After this step, the table with cursor + ** pExpr->iTable will contains the values that make up the RHS. + */ + v = pParse->pVdbe; + assert( v!=0 ); /* OOM detected prior to this routine */ + VdbeNoopComment((v, "begin IN expr")); + eType = sqlite3FindInIndex(pParse, pExpr, &rRhsHasNull); + + /* Figure out the affinity to use to create a key from the results + ** of the expression. affinityStr stores a static string suitable for + ** P4 of OP_MakeRecord. + */ + affinity = comparisonAffinity(pExpr); + + /* Code the LHS, the <expr> from "<expr> IN (...)". + */ + sqlite3ExprCachePush(pParse); + r1 = sqlite3GetTempReg(pParse); + sqlite3ExprCode(pParse, pExpr->pLeft, r1); + + /* If the LHS is NULL, then the result is either false or NULL depending + ** on whether the RHS is empty or not, respectively. + */ + if( destIfNull==destIfFalse ){ + /* Shortcut for the common case where the false and NULL outcomes are + ** the same. */ + sqlite3VdbeAddOp2(v, OP_IsNull, r1, destIfNull); + }else{ + int addr1 = sqlite3VdbeAddOp1(v, OP_NotNull, r1); + sqlite3VdbeAddOp2(v, OP_Rewind, pExpr->iTable, destIfFalse); + sqlite3VdbeAddOp2(v, OP_Goto, 0, destIfNull); + sqlite3VdbeJumpHere(v, addr1); + } + + if( eType==IN_INDEX_ROWID ){ + /* In this case, the RHS is the ROWID of table b-tree + */ + sqlite3VdbeAddOp2(v, OP_MustBeInt, r1, destIfFalse); + sqlite3VdbeAddOp3(v, OP_NotExists, pExpr->iTable, destIfFalse, r1); + }else{ + /* In this case, the RHS is an index b-tree. + */ + sqlite3VdbeAddOp4(v, OP_Affinity, r1, 1, 0, &affinity, 1); + + /* If the set membership test fails, then the result of the + ** "x IN (...)" expression must be either 0 or NULL. If the set + ** contains no NULL values, then the result is 0. If the set + ** contains one or more NULL values, then the result of the + ** expression is also NULL. + */ + if( rRhsHasNull==0 || destIfFalse==destIfNull ){ + /* This branch runs if it is known at compile time that the RHS + ** cannot contain NULL values. This happens as the result + ** of a "NOT NULL" constraint in the database schema. + ** + ** Also run this branch if NULL is equivalent to FALSE + ** for this particular IN operator. + */ + sqlite3VdbeAddOp4Int(v, OP_NotFound, pExpr->iTable, destIfFalse, r1, 1); + + }else{ + /* In this branch, the RHS of the IN might contain a NULL and + ** the presence of a NULL on the RHS makes a difference in the + ** outcome. + */ + int j1, j2, j3; + + /* First check to see if the LHS is contained in the RHS. If so, + ** then the presence of NULLs in the RHS does not matter, so jump + ** over all of the code that follows. + */ + j1 = sqlite3VdbeAddOp4Int(v, OP_Found, pExpr->iTable, 0, r1, 1); + + /* Here we begin generating code that runs if the LHS is not + ** contained within the RHS. Generate additional code that + ** tests the RHS for NULLs. If the RHS contains a NULL then + ** jump to destIfNull. If there are no NULLs in the RHS then + ** jump to destIfFalse. + */ + j2 = sqlite3VdbeAddOp1(v, OP_NotNull, rRhsHasNull); + j3 = sqlite3VdbeAddOp4Int(v, OP_Found, pExpr->iTable, 0, rRhsHasNull, 1); + sqlite3VdbeAddOp2(v, OP_Integer, -1, rRhsHasNull); + sqlite3VdbeJumpHere(v, j3); + sqlite3VdbeAddOp2(v, OP_AddImm, rRhsHasNull, 1); + sqlite3VdbeJumpHere(v, j2); + + /* Jump to the appropriate target depending on whether or not + ** the RHS contains a NULL + */ + sqlite3VdbeAddOp2(v, OP_If, rRhsHasNull, destIfNull); + sqlite3VdbeAddOp2(v, OP_Goto, 0, destIfFalse); + + /* The OP_Found at the top of this branch jumps here when true, + ** causing the overall IN expression evaluation to fall through. + */ + sqlite3VdbeJumpHere(v, j1); + } + } + sqlite3ReleaseTempReg(pParse, r1); + sqlite3ExprCachePop(pParse, 1); + VdbeComment((v, "end IN expr")); +} +#endif /* SQLITE_OMIT_SUBQUERY */ + +/* +** Duplicate an 8-byte value +*/ +static char *dup8bytes(Vdbe *v, const char *in){ + char *out = sqlite3DbMallocRaw(sqlite3VdbeDb(v), 8); + if( out ){ + memcpy(out, in, 8); + } + return out; +} + +#ifndef SQLITE_OMIT_FLOATING_POINT +/* +** Generate an instruction that will put the floating point +** value described by z[0..n-1] into register iMem. +** +** The z[] string will probably not be zero-terminated. But the +** z[n] character is guaranteed to be something that does not look +** like the continuation of the number. +*/ +static void codeReal(Vdbe *v, const char *z, int negateFlag, int iMem){ + if( ALWAYS(z!=0) ){ + double value; + char *zV; + sqlite3AtoF(z, &value, sqlite3Strlen30(z), SQLITE_UTF8); + assert( !sqlite3IsNaN(value) ); /* The new AtoF never returns NaN */ + if( negateFlag ) value = -value; + zV = dup8bytes(v, (char*)&value); + sqlite3VdbeAddOp4(v, OP_Real, 0, iMem, 0, zV, P4_REAL); + } +} +#endif + + +/* +** Generate an instruction that will put the integer describe by +** text z[0..n-1] into register iMem. +** +** Expr.u.zToken is always UTF8 and zero-terminated. +*/ +static void codeInteger(Parse *pParse, Expr *pExpr, int negFlag, int iMem){ + Vdbe *v = pParse->pVdbe; + if( pExpr->flags & EP_IntValue ){ + int i = pExpr->u.iValue; + assert( i>=0 ); + if( negFlag ) i = -i; + sqlite3VdbeAddOp2(v, OP_Integer, i, iMem); + }else{ + int c; + i64 value; + const char *z = pExpr->u.zToken; + assert( z!=0 ); + c = sqlite3Atoi64(z, &value, sqlite3Strlen30(z), SQLITE_UTF8); + if( c==0 || (c==2 && negFlag) ){ + char *zV; + if( negFlag ){ value = c==2 ? SMALLEST_INT64 : -value; } + zV = dup8bytes(v, (char*)&value); + sqlite3VdbeAddOp4(v, OP_Int64, 0, iMem, 0, zV, P4_INT64); + }else{ +#ifdef SQLITE_OMIT_FLOATING_POINT + sqlite3ErrorMsg(pParse, "oversized integer: %s%s", negFlag ? "-" : "", z); +#else + codeReal(v, z, negFlag, iMem); +#endif + } + } +} + +/* +** Clear a cache entry. +*/ +static void cacheEntryClear(Parse *pParse, struct yColCache *p){ + if( p->tempReg ){ + if( pParse->nTempReg<ArraySize(pParse->aTempReg) ){ + pParse->aTempReg[pParse->nTempReg++] = p->iReg; + } + p->tempReg = 0; + } +} + + +/* +** Record in the column cache that a particular column from a +** particular table is stored in a particular register. +*/ +void sqlite3ExprCacheStore(Parse *pParse, int iTab, int iCol, int iReg){ + int i; + int minLru; + int idxLru; + struct yColCache *p; + + assert( iReg>0 ); /* Register numbers are always positive */ + assert( iCol>=-1 && iCol<32768 ); /* Finite column numbers */ + + /* The SQLITE_ColumnCache flag disables the column cache. This is used + ** for testing only - to verify that SQLite always gets the same answer + ** with and without the column cache. + */ + if( pParse->db->flags & 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++){ +#if 0 /* This code wold remove the entry from the cache if it existed */ + if( p->iReg && p->iTable==iTab && p->iColumn==iCol ){ + cacheEntryClear(pParse, p); + p->iLevel = pParse->iCacheLevel; + p->iReg = iReg; + p->lru = pParse->iCacheCnt++; + return; + } +#endif + assert( p->iReg==0 || p->iTable!=iTab || p->iColumn!=iCol ); + } +#endif + + /* Find an empty slot and replace it */ + for(i=0, p=pParse->aColCache; i<SQLITE_N_COLCACHE; i++, p++){ + if( p->iReg==0 ){ + p->iLevel = pParse->iCacheLevel; + p->iTable = iTab; + p->iColumn = iCol; + p->iReg = iReg; + p->tempReg = 0; + p->lru = pParse->iCacheCnt++; + return; + } + } + + /* Replace the last recently used */ + minLru = 0x7fffffff; + idxLru = -1; + for(i=0, p=pParse->aColCache; i<SQLITE_N_COLCACHE; i++, p++){ + if( p->lru<minLru ){ + idxLru = i; + minLru = p->lru; + } + } + if( ALWAYS(idxLru>=0) ){ + p = &pParse->aColCache[idxLru]; + p->iLevel = pParse->iCacheLevel; + p->iTable = iTab; + p->iColumn = iCol; + p->iReg = iReg; + p->tempReg = 0; + p->lru = pParse->iCacheCnt++; + return; + } +} + +/* +** Indicate that registers between iReg..iReg+nReg-1 are being overwritten. +** Purge the range of registers from the column cache. +*/ +void sqlite3ExprCacheRemove(Parse *pParse, int iReg, int nReg){ + int i; + int iLast = iReg + nReg - 1; + struct yColCache *p; + for(i=0, p=pParse->aColCache; i<SQLITE_N_COLCACHE; i++, p++){ + int r = p->iReg; + if( r>=iReg && r<=iLast ){ + cacheEntryClear(pParse, p); + p->iReg = 0; + } + } +} + +/* +** Remember the current column cache context. Any new entries added +** added to the column cache after this call are removed when the +** corresponding pop occurs. +*/ +void sqlite3ExprCachePush(Parse *pParse){ + pParse->iCacheLevel++; +} + +/* +** Remove from the column cache any entries that were added since the +** the previous N Push operations. In other words, restore the cache +** to the state it was in N Pushes ago. +*/ +void sqlite3ExprCachePop(Parse *pParse, int N){ + int i; + struct yColCache *p; + assert( N>0 ); + assert( pParse->iCacheLevel>=N ); + pParse->iCacheLevel -= N; + for(i=0, p=pParse->aColCache; i<SQLITE_N_COLCACHE; i++, p++){ + if( p->iReg && p->iLevel>pParse->iCacheLevel ){ + cacheEntryClear(pParse, p); + p->iReg = 0; + } + } +} + +/* +** When a cached column is reused, make sure that its register is +** no longer available as a temp register. ticket #3879: that same +** register might be in the cache in multiple places, so be sure to +** get them all. +*/ +static void sqlite3ExprCachePinRegister(Parse *pParse, int iReg){ + int i; + struct yColCache *p; + for(i=0, p=pParse->aColCache; i<SQLITE_N_COLCACHE; i++, p++){ + if( p->iReg==iReg ){ + p->tempReg = 0; + } + } +} + +/* +** Generate code to extract the value of the iCol-th column of a table. +*/ +void sqlite3ExprCodeGetColumnOfTable( + Vdbe *v, /* The VDBE under construction */ + Table *pTab, /* The table containing the value */ + int iTabCur, /* The cursor for this table */ + int iCol, /* Index of the column to extract */ + int regOut /* Extract the valud into this register */ +){ + if( iCol<0 || iCol==pTab->iPKey ){ + sqlite3VdbeAddOp2(v, OP_Rowid, iTabCur, regOut); + }else{ + int op = IsVirtual(pTab) ? OP_VColumn : OP_Column; + sqlite3VdbeAddOp3(v, op, iTabCur, iCol, regOut); + } + if( iCol>=0 ){ + sqlite3ColumnDefault(v, pTab, iCol, regOut); + } +} + +/* +** Generate code that will extract the iColumn-th column from +** table pTab and store the column value in a register. An effort +** is made to store the column value in register iReg, but this is +** not guaranteed. The location of the column value is returned. +** +** There must be an open cursor to pTab in iTable when this routine +** is called. If iColumn<0 then code is generated that extracts the rowid. +*/ +int sqlite3ExprCodeGetColumn( + Parse *pParse, /* Parsing and code generating context */ + Table *pTab, /* Description of the table we are reading from */ + int iColumn, /* Index of the table column */ + int iTable, /* The cursor pointing to the table */ + int iReg /* Store results here */ +){ + 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); + sqlite3ExprCacheStore(pParse, iTable, iColumn, iReg); + return iReg; +} + +/* +** Clear all column cache entries. +*/ +void sqlite3ExprCacheClear(Parse *pParse){ + int i; + struct yColCache *p; + + for(i=0, p=pParse->aColCache; i<SQLITE_N_COLCACHE; i++, p++){ + if( p->iReg ){ + cacheEntryClear(pParse, p); + p->iReg = 0; + } + } +} + +/* +** Record the fact that an affinity change has occurred on iCount +** registers starting with iStart. +*/ +void sqlite3ExprCacheAffinityChange(Parse *pParse, int iStart, int iCount){ + sqlite3ExprCacheRemove(pParse, iStart, iCount); +} + +/* +** Generate code to move content from registers iFrom...iFrom+nReg-1 +** over to iTo..iTo+nReg-1. Keep the column cache up-to-date. +*/ +void sqlite3ExprCodeMove(Parse *pParse, int iFrom, int iTo, int nReg){ + int i; + struct yColCache *p; + if( NEVER(iFrom==iTo) ) return; + sqlite3VdbeAddOp3(pParse->pVdbe, OP_Move, iFrom, iTo, nReg); + for(i=0, p=pParse->aColCache; i<SQLITE_N_COLCACHE; i++, p++){ + int x = p->iReg; + if( x>=iFrom && x<iFrom+nReg ){ + p->iReg += iTo-iFrom; + } + } +} + +/* +** Generate code to copy content from registers iFrom...iFrom+nReg-1 +** over to iTo..iTo+nReg-1. +*/ +void sqlite3ExprCodeCopy(Parse *pParse, int iFrom, int iTo, int nReg){ + int i; + if( NEVER(iFrom==iTo) ) return; + for(i=0; i<nReg; i++){ + sqlite3VdbeAddOp2(pParse->pVdbe, OP_Copy, iFrom+i, iTo+i); + } +} + +#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 */ + +/* +** Generate code into the current Vdbe to evaluate the given +** expression. Attempt to store the results in register "target". +** Return the register where results are stored. +** +** With this routine, there is no guarantee that results will +** be stored in target. The result might be stored in some other +** register if it is convenient to do so. The calling function +** must check the return code and move the results to the desired +** register. +*/ +int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target){ + Vdbe *v = pParse->pVdbe; /* The VM under construction */ + int op; /* The opcode being coded */ + int inReg = target; /* Results stored in register inReg */ + int regFree1 = 0; /* If non-zero free this temporary register */ + int regFree2 = 0; /* If non-zero free this temporary register */ + int r1, r2, r3, r4; /* Various register numbers */ + sqlite3 *db = pParse->db; /* The database connection */ + + assert( target>0 && target<=pParse->nMem ); + if( v==0 ){ + assert( pParse->db->mallocFailed ); + return 0; + } + + if( pExpr==0 ){ + op = TK_NULL; + }else{ + op = pExpr->op; + } + switch( op ){ + case TK_AGG_COLUMN: { + AggInfo *pAggInfo = pExpr->pAggInfo; + struct AggInfo_col *pCol = &pAggInfo->aCol[pExpr->iAgg]; + if( !pAggInfo->directMode ){ + assert( pCol->iMem>0 ); + inReg = pCol->iMem; + break; + }else if( pAggInfo->useSortingIdx ){ + sqlite3VdbeAddOp3(v, OP_Column, pAggInfo->sortingIdxPTab, + pCol->iSorterColumn, target); + break; + } + /* Otherwise, fall thru into the TK_COLUMN case */ + } + case TK_COLUMN: { + if( pExpr->iTable<0 ){ + /* This only happens when coding check constraints */ + assert( pParse->ckBase>0 ); + inReg = pExpr->iColumn + pParse->ckBase; + }else{ + inReg = sqlite3ExprCodeGetColumn(pParse, pExpr->pTab, + pExpr->iColumn, pExpr->iTable, target); + } + break; + } + case TK_INTEGER: { + codeInteger(pParse, pExpr, 0, target); + break; + } +#ifndef SQLITE_OMIT_FLOATING_POINT + case TK_FLOAT: { + assert( !ExprHasProperty(pExpr, EP_IntValue) ); + codeReal(v, pExpr->u.zToken, 0, target); + break; + } +#endif + case TK_STRING: { + assert( !ExprHasProperty(pExpr, EP_IntValue) ); + sqlite3VdbeAddOp4(v, OP_String8, 0, target, 0, pExpr->u.zToken, 0); + break; + } + case TK_NULL: { + sqlite3VdbeAddOp2(v, OP_Null, 0, target); + break; + } +#ifndef SQLITE_OMIT_BLOB_LITERAL + case TK_BLOB: { + int n; + const char *z; + char *zBlob; + assert( !ExprHasProperty(pExpr, EP_IntValue) ); + assert( pExpr->u.zToken[0]=='x' || pExpr->u.zToken[0]=='X' ); + assert( pExpr->u.zToken[1]=='\'' ); + z = &pExpr->u.zToken[2]; + n = sqlite3Strlen30(z) - 1; + assert( z[n]=='\'' ); + zBlob = sqlite3HexToBlob(sqlite3VdbeDb(v), z, n); + sqlite3VdbeAddOp4(v, OP_Blob, n/2, target, 0, zBlob, P4_DYNAMIC); + break; + } +#endif + case TK_VARIABLE: { + assert( !ExprHasProperty(pExpr, EP_IntValue) ); + assert( pExpr->u.zToken!=0 ); + assert( pExpr->u.zToken[0]!=0 ); + sqlite3VdbeAddOp2(v, OP_Variable, pExpr->iColumn, target); + if( pExpr->u.zToken[1]!=0 ){ + assert( pExpr->u.zToken[0]=='?' + || strcmp(pExpr->u.zToken, pParse->azVar[pExpr->iColumn-1])==0 ); + sqlite3VdbeChangeP4(v, -1, pParse->azVar[pExpr->iColumn-1], P4_STATIC); + } + break; + } + case TK_REGISTER: { + inReg = pExpr->iTable; + break; + } + case TK_AS: { + inReg = sqlite3ExprCodeTarget(pParse, pExpr->pLeft, target); + break; + } +#ifndef SQLITE_OMIT_CAST + case TK_CAST: { + /* Expressions of the form: CAST(pLeft AS token) */ + int aff, to_op; + inReg = sqlite3ExprCodeTarget(pParse, pExpr->pLeft, target); + assert( !ExprHasProperty(pExpr, EP_IntValue) ); + aff = sqlite3AffinityType(pExpr->u.zToken); + to_op = aff - SQLITE_AFF_TEXT + OP_ToText; + assert( to_op==OP_ToText || aff!=SQLITE_AFF_TEXT ); + assert( to_op==OP_ToBlob || aff!=SQLITE_AFF_NONE ); + assert( to_op==OP_ToNumeric || aff!=SQLITE_AFF_NUMERIC ); + assert( to_op==OP_ToInt || aff!=SQLITE_AFF_INTEGER ); + assert( to_op==OP_ToReal || aff!=SQLITE_AFF_REAL ); + testcase( to_op==OP_ToText ); + testcase( to_op==OP_ToBlob ); + testcase( to_op==OP_ToNumeric ); + testcase( to_op==OP_ToInt ); + testcase( to_op==OP_ToReal ); + if( inReg!=target ){ + sqlite3VdbeAddOp2(v, OP_SCopy, inReg, target); + inReg = target; + } + sqlite3VdbeAddOp1(v, to_op, inReg); + testcase( usedAsColumnCache(pParse, inReg, inReg) ); + sqlite3ExprCacheAffinityChange(pParse, inReg, 1); + break; + } +#endif /* SQLITE_OMIT_CAST */ + case TK_LT: + case TK_LE: + case TK_GT: + case TK_GE: + case TK_NE: + case TK_EQ: { + assert( TK_LT==OP_Lt ); + assert( TK_LE==OP_Le ); + assert( TK_GT==OP_Gt ); + assert( TK_GE==OP_Ge ); + assert( TK_EQ==OP_Eq ); + assert( TK_NE==OP_Ne ); + testcase( op==TK_LT ); + testcase( op==TK_LE ); + testcase( op==TK_GT ); + testcase( op==TK_GE ); + testcase( op==TK_EQ ); + testcase( op==TK_NE ); + r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free1); + r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, ®Free2); + codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op, + r1, r2, inReg, SQLITE_STOREP2); + testcase( regFree1==0 ); + testcase( regFree2==0 ); + break; + } + case TK_IS: + case TK_ISNOT: { + testcase( op==TK_IS ); + testcase( op==TK_ISNOT ); + r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free1); + r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, ®Free2); + op = (op==TK_IS) ? TK_EQ : TK_NE; + codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op, + r1, r2, inReg, SQLITE_STOREP2 | SQLITE_NULLEQ); + testcase( regFree1==0 ); + testcase( regFree2==0 ); + break; + } + case TK_AND: + case TK_OR: + case TK_PLUS: + case TK_STAR: + case TK_MINUS: + case TK_REM: + case TK_BITAND: + case TK_BITOR: + case TK_SLASH: + case TK_LSHIFT: + case TK_RSHIFT: + case TK_CONCAT: { + assert( TK_AND==OP_And ); + assert( TK_OR==OP_Or ); + assert( TK_PLUS==OP_Add ); + assert( TK_MINUS==OP_Subtract ); + assert( TK_REM==OP_Remainder ); + assert( TK_BITAND==OP_BitAnd ); + assert( TK_BITOR==OP_BitOr ); + assert( TK_SLASH==OP_Divide ); + assert( TK_LSHIFT==OP_ShiftLeft ); + assert( TK_RSHIFT==OP_ShiftRight ); + assert( TK_CONCAT==OP_Concat ); + testcase( op==TK_AND ); + testcase( op==TK_OR ); + testcase( op==TK_PLUS ); + testcase( op==TK_MINUS ); + testcase( op==TK_REM ); + testcase( op==TK_BITAND ); + testcase( op==TK_BITOR ); + testcase( op==TK_SLASH ); + testcase( op==TK_LSHIFT ); + testcase( op==TK_RSHIFT ); + testcase( op==TK_CONCAT ); + r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free1); + r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, ®Free2); + sqlite3VdbeAddOp3(v, op, r2, r1, target); + testcase( regFree1==0 ); + testcase( regFree2==0 ); + break; + } + case TK_UMINUS: { + Expr *pLeft = pExpr->pLeft; + assert( pLeft ); + if( pLeft->op==TK_INTEGER ){ + codeInteger(pParse, pLeft, 1, target); +#ifndef SQLITE_OMIT_FLOATING_POINT + }else if( pLeft->op==TK_FLOAT ){ + assert( !ExprHasProperty(pExpr, EP_IntValue) ); + codeReal(v, pLeft->u.zToken, 1, target); +#endif + }else{ + regFree1 = r1 = sqlite3GetTempReg(pParse); + sqlite3VdbeAddOp2(v, OP_Integer, 0, r1); + r2 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free2); + sqlite3VdbeAddOp3(v, OP_Subtract, r2, r1, target); + testcase( regFree2==0 ); + } + inReg = target; + break; + } + case TK_BITNOT: + case TK_NOT: { + assert( TK_BITNOT==OP_BitNot ); + assert( TK_NOT==OP_Not ); + testcase( op==TK_BITNOT ); + testcase( op==TK_NOT ); + r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free1); + testcase( regFree1==0 ); + inReg = target; + sqlite3VdbeAddOp2(v, op, r1, inReg); + break; + } + case TK_ISNULL: + case TK_NOTNULL: { + int addr; + assert( TK_ISNULL==OP_IsNull ); + assert( TK_NOTNULL==OP_NotNull ); + testcase( op==TK_ISNULL ); + testcase( op==TK_NOTNULL ); + sqlite3VdbeAddOp2(v, OP_Integer, 1, target); + r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free1); + testcase( regFree1==0 ); + addr = sqlite3VdbeAddOp1(v, op, r1); + sqlite3VdbeAddOp2(v, OP_AddImm, target, -1); + sqlite3VdbeJumpHere(v, addr); + break; + } + case TK_AGG_FUNCTION: { + AggInfo *pInfo = pExpr->pAggInfo; + if( pInfo==0 ){ + assert( !ExprHasProperty(pExpr, EP_IntValue) ); + sqlite3ErrorMsg(pParse, "misuse of aggregate: %s()", pExpr->u.zToken); + }else{ + inReg = pInfo->aFunc[pExpr->iAgg].iMem; + } + break; + } + case TK_CONST_FUNC: + case TK_FUNCTION: { + ExprList *pFarg; /* List of function arguments */ + int nFarg; /* Number of function arguments */ + FuncDef *pDef; /* The function definition object */ + int nId; /* Length of the function name in bytes */ + const char *zId; /* The function name */ + int constMask = 0; /* Mask of function arguments that are constant */ + int i; /* Loop counter */ + u8 enc = ENC(db); /* The text encoding used by this database */ + CollSeq *pColl = 0; /* A collating sequence */ + + assert( !ExprHasProperty(pExpr, EP_xIsSelect) ); + testcase( op==TK_CONST_FUNC ); + testcase( op==TK_FUNCTION ); + if( ExprHasAnyProperty(pExpr, EP_TokenOnly) ){ + pFarg = 0; + }else{ + pFarg = pExpr->x.pList; + } + nFarg = pFarg ? pFarg->nExpr : 0; + assert( !ExprHasProperty(pExpr, EP_IntValue) ); + zId = pExpr->u.zToken; + nId = sqlite3Strlen30(zId); + pDef = sqlite3FindFunction(db, zId, nId, nFarg, enc, 0); + if( pDef==0 ){ + sqlite3ErrorMsg(pParse, "unknown function: %.*s()", nId, zId); + break; + } + + /* Attempt a direct implementation of the built-in COALESCE() and + ** IFNULL() functions. This avoids unnecessary evalation of + ** arguments past the first non-NULL argument. + */ + if( pDef->flags & SQLITE_FUNC_COALESCE ){ + int endCoalesce = sqlite3VdbeMakeLabel(v); + assert( nFarg>=2 ); + sqlite3ExprCode(pParse, pFarg->a[0].pExpr, target); + for(i=1; i<nFarg; i++){ + sqlite3VdbeAddOp2(v, OP_NotNull, target, endCoalesce); + sqlite3ExprCacheRemove(pParse, target, 1); + sqlite3ExprCachePush(pParse); + sqlite3ExprCode(pParse, pFarg->a[i].pExpr, target); + sqlite3ExprCachePop(pParse, 1); + } + sqlite3VdbeResolveLabel(v, endCoalesce); + break; + } + + + if( pFarg ){ + r1 = sqlite3GetTempRange(pParse, nFarg); + sqlite3ExprCachePush(pParse); /* Ticket 2ea2425d34be */ + sqlite3ExprCodeExprList(pParse, pFarg, r1, 1); + sqlite3ExprCachePop(pParse, 1); /* Ticket 2ea2425d34be */ + }else{ + r1 = 0; + } +#ifndef SQLITE_OMIT_VIRTUALTABLE + /* Possibly overload the function if the first argument is + ** a virtual table column. + ** + ** For infix functions (LIKE, GLOB, REGEXP, and MATCH) use the + ** second argument, not the first, as the argument to test to + ** see if it is a column in a virtual table. This is done because + ** the left operand of infix functions (the operand we want to + ** control overloading) ends up as the second argument to the + ** function. The expression "A glob B" is equivalent to + ** "glob(B,A). We want to use the A in "A glob B" to test + ** for function overloading. But we use the B term in "glob(B,A)". + */ + if( nFarg>=2 && (pExpr->flags & EP_InfixFunc) ){ + pDef = sqlite3VtabOverloadFunction(db, pDef, nFarg, pFarg->a[1].pExpr); + }else if( nFarg>0 ){ + pDef = sqlite3VtabOverloadFunction(db, pDef, nFarg, pFarg->a[0].pExpr); + } +#endif + for(i=0; i<nFarg; i++){ + if( i<32 && sqlite3ExprIsConstant(pFarg->a[i].pExpr) ){ + constMask |= (1<<i); + } + if( (pDef->flags & SQLITE_FUNC_NEEDCOLL)!=0 && !pColl ){ + pColl = sqlite3ExprCollSeq(pParse, pFarg->a[i].pExpr); + } + } + if( pDef->flags & SQLITE_FUNC_NEEDCOLL ){ + if( !pColl ) pColl = db->pDfltColl; + sqlite3VdbeAddOp4(v, OP_CollSeq, 0, 0, 0, (char *)pColl, P4_COLLSEQ); + } + sqlite3VdbeAddOp4(v, OP_Function, constMask, r1, target, + (char*)pDef, P4_FUNCDEF); + sqlite3VdbeChangeP5(v, (u8)nFarg); + if( nFarg ){ + sqlite3ReleaseTempRange(pParse, r1, nFarg); + } + break; + } +#ifndef SQLITE_OMIT_SUBQUERY + case TK_EXISTS: + case TK_SELECT: { + testcase( op==TK_EXISTS ); + testcase( op==TK_SELECT ); + inReg = sqlite3CodeSubselect(pParse, pExpr, 0, 0); + break; + } + case TK_IN: { + int destIfFalse = sqlite3VdbeMakeLabel(v); + int destIfNull = sqlite3VdbeMakeLabel(v); + sqlite3VdbeAddOp2(v, OP_Null, 0, target); + sqlite3ExprCodeIN(pParse, pExpr, destIfFalse, destIfNull); + sqlite3VdbeAddOp2(v, OP_Integer, 1, target); + sqlite3VdbeResolveLabel(v, destIfFalse); + sqlite3VdbeAddOp2(v, OP_AddImm, target, 0); + sqlite3VdbeResolveLabel(v, destIfNull); + break; + } +#endif /* SQLITE_OMIT_SUBQUERY */ + + + /* + ** x BETWEEN y AND z + ** + ** This is equivalent to + ** + ** x>=y AND x<=z + ** + ** X is stored in pExpr->pLeft. + ** Y is stored in pExpr->pList->a[0].pExpr. + ** Z is stored in pExpr->pList->a[1].pExpr. + */ + case TK_BETWEEN: { + Expr *pLeft = pExpr->pLeft; + struct ExprList_item *pLItem = pExpr->x.pList->a; + Expr *pRight = pLItem->pExpr; + + r1 = sqlite3ExprCodeTemp(pParse, pLeft, ®Free1); + r2 = sqlite3ExprCodeTemp(pParse, pRight, ®Free2); + testcase( regFree1==0 ); + testcase( regFree2==0 ); + r3 = sqlite3GetTempReg(pParse); + r4 = sqlite3GetTempReg(pParse); + codeCompare(pParse, pLeft, pRight, OP_Ge, + r1, r2, r3, SQLITE_STOREP2); + pLItem++; + pRight = pLItem->pExpr; + sqlite3ReleaseTempReg(pParse, regFree2); + r2 = sqlite3ExprCodeTemp(pParse, pRight, ®Free2); + testcase( regFree2==0 ); + codeCompare(pParse, pLeft, pRight, OP_Le, r1, r2, r4, SQLITE_STOREP2); + sqlite3VdbeAddOp3(v, OP_And, r3, r4, target); + sqlite3ReleaseTempReg(pParse, r3); + sqlite3ReleaseTempReg(pParse, r4); + break; + } + case TK_UPLUS: { + inReg = sqlite3ExprCodeTarget(pParse, pExpr->pLeft, target); + break; + } + + case TK_TRIGGER: { + /* If the opcode is TK_TRIGGER, then the expression is a reference + ** to a column in the new.* or old.* pseudo-tables available to + ** trigger programs. In this case Expr.iTable is set to 1 for the + ** new.* pseudo-table, or 0 for the old.* pseudo-table. Expr.iColumn + ** is set to the column of the pseudo-table to read, or to -1 to + ** read the rowid field. + ** + ** The expression is implemented using an OP_Param opcode. The p1 + ** parameter is set to 0 for an old.rowid reference, or to (i+1) + ** to reference another column of the old.* pseudo-table, where + ** i is the index of the column. For a new.rowid reference, p1 is + ** set to (n+1), where n is the number of columns in each pseudo-table. + ** For a reference to any other column in the new.* pseudo-table, p1 + ** is set to (n+2+i), where n and i are as defined previously. For + ** example, if the table on which triggers are being fired is + ** declared as: + ** + ** CREATE TABLE t1(a, b); + ** + ** Then p1 is interpreted as follows: + ** + ** p1==0 -> old.rowid p1==3 -> new.rowid + ** p1==1 -> old.a p1==4 -> new.a + ** p1==2 -> old.b p1==5 -> new.b + */ + Table *pTab = pExpr->pTab; + int p1 = pExpr->iTable * (pTab->nCol+1) + 1 + pExpr->iColumn; + + assert( pExpr->iTable==0 || pExpr->iTable==1 ); + assert( pExpr->iColumn>=-1 && pExpr->iColumn<pTab->nCol ); + assert( pTab->iPKey<0 || pExpr->iColumn!=pTab->iPKey ); + assert( p1>=0 && p1<(pTab->nCol*2+2) ); + + sqlite3VdbeAddOp2(v, OP_Param, p1, target); + VdbeComment((v, "%s.%s -> $%d", + (pExpr->iTable ? "new" : "old"), + (pExpr->iColumn<0 ? "rowid" : pExpr->pTab->aCol[pExpr->iColumn].zName), + target + )); + +#ifndef SQLITE_OMIT_FLOATING_POINT + /* If the column has REAL affinity, it may currently be stored as an + ** integer. Use OP_RealAffinity to make sure it is really real. */ + if( pExpr->iColumn>=0 + && pTab->aCol[pExpr->iColumn].affinity==SQLITE_AFF_REAL + ){ + sqlite3VdbeAddOp1(v, OP_RealAffinity, target); + } +#endif + break; + } + + + /* + ** Form A: + ** CASE x WHEN e1 THEN r1 WHEN e2 THEN r2 ... WHEN eN THEN rN ELSE y END + ** + ** Form B: + ** CASE WHEN e1 THEN r1 WHEN e2 THEN r2 ... WHEN eN THEN rN ELSE y END + ** + ** Form A is can be transformed into the equivalent form B as follows: + ** CASE WHEN x=e1 THEN r1 WHEN x=e2 THEN r2 ... + ** WHEN x=eN THEN rN ELSE y END + ** + ** X (if it exists) is in pExpr->pLeft. + ** Y is in pExpr->pRight. The Y is also optional. If there is no + ** ELSE clause and no other term matches, then the result of the + ** exprssion is NULL. + ** Ei is in pExpr->pList->a[i*2] and Ri is pExpr->pList->a[i*2+1]. + ** + ** The result of the expression is the Ri for the first matching Ei, + ** or if there is no matching Ei, the ELSE term Y, or if there is + ** no ELSE term, NULL. + */ + default: assert( op==TK_CASE ); { + int endLabel; /* GOTO label for end of CASE stmt */ + int nextCase; /* GOTO label for next WHEN clause */ + int nExpr; /* 2x number of WHEN terms */ + int i; /* Loop counter */ + ExprList *pEList; /* List of WHEN terms */ + struct ExprList_item *aListelem; /* Array of WHEN terms */ + Expr opCompare; /* The X==Ei expression */ + Expr cacheX; /* Cached expression X */ + Expr *pX; /* The X expression */ + Expr *pTest = 0; /* X==Ei (form A) or just Ei (form B) */ + VVA_ONLY( int iCacheLevel = pParse->iCacheLevel; ) + + assert( !ExprHasProperty(pExpr, EP_xIsSelect) && pExpr->x.pList ); + assert((pExpr->x.pList->nExpr % 2) == 0); + assert(pExpr->x.pList->nExpr > 0); + pEList = pExpr->x.pList; + aListelem = pEList->a; + nExpr = pEList->nExpr; + endLabel = sqlite3VdbeMakeLabel(v); + if( (pX = pExpr->pLeft)!=0 ){ + cacheX = *pX; + testcase( pX->op==TK_COLUMN ); + testcase( pX->op==TK_REGISTER ); + cacheX.iTable = sqlite3ExprCodeTemp(pParse, pX, ®Free1); + testcase( regFree1==0 ); + cacheX.op = TK_REGISTER; + opCompare.op = TK_EQ; + opCompare.pLeft = &cacheX; + pTest = &opCompare; + /* Ticket b351d95f9cd5ef17e9d9dbae18f5ca8611190001: + ** The value in regFree1 might get SCopy-ed into the file result. + ** So make sure that the regFree1 register is not reused for other + ** purposes and possibly overwritten. */ + regFree1 = 0; + } + for(i=0; i<nExpr; i=i+2){ + sqlite3ExprCachePush(pParse); + if( pX ){ + assert( pTest!=0 ); + opCompare.pRight = aListelem[i].pExpr; + }else{ + pTest = aListelem[i].pExpr; + } + nextCase = sqlite3VdbeMakeLabel(v); + testcase( pTest->op==TK_COLUMN ); + sqlite3ExprIfFalse(pParse, pTest, nextCase, SQLITE_JUMPIFNULL); + testcase( aListelem[i+1].pExpr->op==TK_COLUMN ); + testcase( aListelem[i+1].pExpr->op==TK_REGISTER ); + sqlite3ExprCode(pParse, aListelem[i+1].pExpr, target); + sqlite3VdbeAddOp2(v, OP_Goto, 0, endLabel); + sqlite3ExprCachePop(pParse, 1); + sqlite3VdbeResolveLabel(v, nextCase); + } + if( pExpr->pRight ){ + sqlite3ExprCachePush(pParse); + sqlite3ExprCode(pParse, pExpr->pRight, target); + sqlite3ExprCachePop(pParse, 1); + }else{ + sqlite3VdbeAddOp2(v, OP_Null, 0, target); + } + assert( db->mallocFailed || pParse->nErr>0 + || pParse->iCacheLevel==iCacheLevel ); + sqlite3VdbeResolveLabel(v, endLabel); + break; + } +#ifndef SQLITE_OMIT_TRIGGER + case TK_RAISE: { + assert( pExpr->affinity==OE_Rollback + || pExpr->affinity==OE_Abort + || pExpr->affinity==OE_Fail + || pExpr->affinity==OE_Ignore + ); + if( !pParse->pTriggerTab ){ + sqlite3ErrorMsg(pParse, + "RAISE() may only be used within a trigger-program"); + return 0; + } + if( pExpr->affinity==OE_Abort ){ + sqlite3MayAbort(pParse); + } + assert( !ExprHasProperty(pExpr, EP_IntValue) ); + if( pExpr->affinity==OE_Ignore ){ + sqlite3VdbeAddOp4( + v, OP_Halt, SQLITE_OK, OE_Ignore, 0, pExpr->u.zToken,0); + }else{ + sqlite3HaltConstraint(pParse, pExpr->affinity, pExpr->u.zToken, 0); + } + + break; + } +#endif + } + sqlite3ReleaseTempReg(pParse, regFree1); + sqlite3ReleaseTempReg(pParse, regFree2); + return inReg; +} + +/* +** Generate code to evaluate an expression and store the results +** into a register. Return the register number where the results +** are stored. +** +** If the register is a temporary register that can be deallocated, +** then write its number into *pReg. If the result register is not +** a temporary, then set *pReg to zero. +*/ +int sqlite3ExprCodeTemp(Parse *pParse, Expr *pExpr, int *pReg){ + int r1 = sqlite3GetTempReg(pParse); + int r2 = sqlite3ExprCodeTarget(pParse, pExpr, r1); + if( r2==r1 ){ + *pReg = r1; + }else{ + sqlite3ReleaseTempReg(pParse, r1); + *pReg = 0; + } + return r2; +} + +/* +** Generate code that will evaluate expression pExpr and store the +** results in register target. The results are guaranteed to appear +** in register target. +*/ +int sqlite3ExprCode(Parse *pParse, Expr *pExpr, int target){ + int inReg; + + assert( target>0 && target<=pParse->nMem ); + if( pExpr && pExpr->op==TK_REGISTER ){ + sqlite3VdbeAddOp2(pParse->pVdbe, OP_Copy, pExpr->iTable, target); + }else{ + inReg = sqlite3ExprCodeTarget(pParse, pExpr, target); + assert( pParse->pVdbe || pParse->db->mallocFailed ); + if( inReg!=target && pParse->pVdbe ){ + sqlite3VdbeAddOp2(pParse->pVdbe, OP_SCopy, inReg, target); + } + } + return target; +} + +/* +** Generate code that evalutes the given expression and puts the result +** in register target. +** +** Also make a copy of the expression results into another "cache" register +** and modify the expression so that the next time it is evaluated, +** the result is a copy of the cache register. +** +** This routine is used for expressions that are used multiple +** times. They are evaluated once and the results of the expression +** are reused. +*/ +int sqlite3ExprCodeAndCache(Parse *pParse, Expr *pExpr, int target){ + Vdbe *v = pParse->pVdbe; + int inReg; + inReg = sqlite3ExprCode(pParse, pExpr, target); + assert( target>0 ); + /* This routine is called for terms to INSERT or UPDATE. And the only + ** other place where expressions can be converted into TK_REGISTER is + ** in WHERE clause processing. So as currently implemented, there is + ** no way for a TK_REGISTER to exist here. But it seems prudent to + ** keep the ALWAYS() in case the conditions above change with future + ** modifications or enhancements. */ + if( ALWAYS(pExpr->op!=TK_REGISTER) ){ + int iMem; + iMem = ++pParse->nMem; + sqlite3VdbeAddOp2(v, OP_Copy, inReg, iMem); + pExpr->iTable = iMem; + pExpr->op2 = pExpr->op; + pExpr->op = TK_REGISTER; + } + return inReg; +} + +/* +** Return TRUE if pExpr is an constant expression that is appropriate +** for factoring out of a loop. Appropriate expressions are: +** +** * Any expression that evaluates to two or more opcodes. +** +** * Any OP_Integer, OP_Real, OP_String, OP_Blob, OP_Null, +** or OP_Variable that does not need to be placed in a +** specific register. +** +** There is no point in factoring out single-instruction constant +** expressions that need to be placed in a particular register. +** We could factor them out, but then we would end up adding an +** OP_SCopy instruction to move the value into the correct register +** later. We might as well just use the original instruction and +** avoid the OP_SCopy. +*/ +static int isAppropriateForFactoring(Expr *p){ + if( !sqlite3ExprIsConstantNotJoin(p) ){ + return 0; /* Only constant expressions are appropriate for factoring */ + } + if( (p->flags & EP_FixedDest)==0 ){ + return 1; /* Any constant without a fixed destination is appropriate */ + } + while( p->op==TK_UPLUS ) p = p->pLeft; + switch( p->op ){ +#ifndef SQLITE_OMIT_BLOB_LITERAL + case TK_BLOB: +#endif + case TK_VARIABLE: + case TK_INTEGER: + case TK_FLOAT: + case TK_NULL: + case TK_STRING: { + testcase( p->op==TK_BLOB ); + testcase( p->op==TK_VARIABLE ); + testcase( p->op==TK_INTEGER ); + testcase( p->op==TK_FLOAT ); + testcase( p->op==TK_NULL ); + testcase( p->op==TK_STRING ); + /* Single-instruction constants with a fixed destination are + ** better done in-line. If we factor them, they will just end + ** up generating an OP_SCopy to move the value to the destination + ** register. */ + return 0; + } + case TK_UMINUS: { + if( p->pLeft->op==TK_FLOAT || p->pLeft->op==TK_INTEGER ){ + return 0; + } + break; + } + default: { + break; + } + } + return 1; +} + +/* +** If pExpr is a constant expression that is appropriate for +** factoring out of a loop, then evaluate the expression +** into a register and convert the expression into a TK_REGISTER +** expression. +*/ +static int evalConstExpr(Walker *pWalker, Expr *pExpr){ + Parse *pParse = pWalker->pParse; + switch( pExpr->op ){ + case TK_IN: + case TK_REGISTER: { + return WRC_Prune; + } + case TK_FUNCTION: + case TK_AGG_FUNCTION: + case TK_CONST_FUNC: { + /* The arguments to a function have a fixed destination. + ** Mark them this way to avoid generated unneeded OP_SCopy + ** instructions. + */ + ExprList *pList = pExpr->x.pList; + assert( !ExprHasProperty(pExpr, EP_xIsSelect) ); + if( pList ){ + int i = pList->nExpr; + struct ExprList_item *pItem = pList->a; + for(; i>0; i--, pItem++){ + if( ALWAYS(pItem->pExpr) ) pItem->pExpr->flags |= EP_FixedDest; + } + } + break; + } + } + if( isAppropriateForFactoring(pExpr) ){ + int r1 = ++pParse->nMem; + int r2; + r2 = sqlite3ExprCodeTarget(pParse, pExpr, r1); + if( NEVER(r1!=r2) ) sqlite3ReleaseTempReg(pParse, r1); + pExpr->op2 = pExpr->op; + pExpr->op = TK_REGISTER; + pExpr->iTable = r2; + return WRC_Prune; + } + return WRC_Continue; +} + +/* +** Preevaluate constant subexpressions within pExpr and store the +** results in registers. Modify pExpr so that the constant subexpresions +** are TK_REGISTER opcodes that refer to the precomputed values. +** +** This routine is a no-op if the jump to the cookie-check code has +** already occur. Since the cookie-check jump is generated prior to +** any other serious processing, this check ensures that there is no +** way to accidently bypass the constant initializations. +** +** This routine is also a no-op if the SQLITE_FactorOutConst optimization +** is disabled via the sqlite3_test_control(SQLITE_TESTCTRL_OPTIMIZATIONS) +** interface. This allows test logic to verify that the same answer is +** obtained for queries regardless of whether or not constants are +** precomputed into registers or if they are inserted in-line. +*/ +void sqlite3ExprCodeConstants(Parse *pParse, Expr *pExpr){ + Walker w; + if( pParse->cookieGoto ) return; + if( (pParse->db->flags & SQLITE_FactorOutConst)!=0 ) return; + w.xExprCallback = evalConstExpr; + w.xSelectCallback = 0; + w.pParse = pParse; + sqlite3WalkExpr(&w, pExpr); +} + + +/* +** Generate code that pushes the value of every element of the given +** expression list into a sequence of registers beginning at target. +** +** Return the number of elements evaluated. +*/ +int sqlite3ExprCodeExprList( + Parse *pParse, /* Parsing context */ + ExprList *pList, /* The expression list to be coded */ + int target, /* Where to write results */ + int doHardCopy /* Make a hard copy of every element */ +){ + struct ExprList_item *pItem; + int i, n; + assert( pList!=0 ); + assert( target>0 ); + assert( pParse->pVdbe!=0 ); /* Never gets this far otherwise */ + n = pList->nExpr; + for(pItem=pList->a, i=0; i<n; i++, pItem++){ + Expr *pExpr = pItem->pExpr; + int inReg = sqlite3ExprCodeTarget(pParse, pExpr, target+i); + if( inReg!=target+i ){ + sqlite3VdbeAddOp2(pParse->pVdbe, doHardCopy ? OP_Copy : OP_SCopy, + inReg, target+i); + } + } + return n; +} + +/* +** Generate code for a BETWEEN operator. +** +** x BETWEEN y AND z +** +** The above is equivalent to +** +** x>=y AND x<=z +** +** Code it as such, taking care to do the common subexpression +** elementation of x. +*/ +static void exprCodeBetween( + Parse *pParse, /* Parsing and code generating context */ + Expr *pExpr, /* The BETWEEN expression */ + int dest, /* Jump here if the jump is taken */ + int jumpIfTrue, /* Take the jump if the BETWEEN is true */ + int jumpIfNull /* Take the jump if the BETWEEN is NULL */ +){ + Expr exprAnd; /* The AND operator in x>=y AND x<=z */ + Expr compLeft; /* The x>=y term */ + Expr compRight; /* The x<=z term */ + Expr exprX; /* The x subexpression */ + int regFree1 = 0; /* Temporary use register */ + + assert( !ExprHasProperty(pExpr, EP_xIsSelect) ); + exprX = *pExpr->pLeft; + exprAnd.op = TK_AND; + exprAnd.pLeft = &compLeft; + exprAnd.pRight = &compRight; + compLeft.op = TK_GE; + compLeft.pLeft = &exprX; + compLeft.pRight = pExpr->x.pList->a[0].pExpr; + compRight.op = TK_LE; + compRight.pLeft = &exprX; + compRight.pRight = pExpr->x.pList->a[1].pExpr; + exprX.iTable = sqlite3ExprCodeTemp(pParse, &exprX, ®Free1); + exprX.op = TK_REGISTER; + 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; /* Existance of VDBE checked by caller */ + if( NEVER(pExpr==0) ) return; /* No way this can happen */ + op = pExpr->op; + switch( op ){ + case TK_AND: { + int d2 = sqlite3VdbeMakeLabel(v); + testcase( jumpIfNull==0 ); + sqlite3ExprCachePush(pParse); + sqlite3ExprIfFalse(pParse, pExpr->pLeft, d2,jumpIfNull^SQLITE_JUMPIFNULL); + sqlite3ExprIfTrue(pParse, pExpr->pRight, dest, jumpIfNull); + sqlite3VdbeResolveLabel(v, d2); + sqlite3ExprCachePop(pParse, 1); + break; + } + case TK_OR: { + testcase( jumpIfNull==0 ); + sqlite3ExprIfTrue(pParse, pExpr->pLeft, dest, jumpIfNull); + sqlite3ExprIfTrue(pParse, pExpr->pRight, dest, jumpIfNull); + break; + } + case TK_NOT: { + testcase( jumpIfNull==0 ); + sqlite3ExprIfFalse(pParse, pExpr->pLeft, dest, jumpIfNull); + break; + } + case TK_LT: + case TK_LE: + case TK_GT: + case TK_GE: + case TK_NE: + case TK_EQ: { + assert( TK_LT==OP_Lt ); + assert( TK_LE==OP_Le ); + assert( TK_GT==OP_Gt ); + assert( TK_GE==OP_Ge ); + assert( TK_EQ==OP_Eq ); + assert( TK_NE==OP_Ne ); + testcase( op==TK_LT ); + testcase( op==TK_LE ); + testcase( op==TK_GT ); + testcase( op==TK_GE ); + testcase( op==TK_EQ ); + testcase( op==TK_NE ); + testcase( jumpIfNull==0 ); + r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free1); + r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, ®Free2); + codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op, + r1, r2, dest, jumpIfNull); + testcase( regFree1==0 ); + testcase( regFree2==0 ); + break; + } + case TK_IS: + case TK_ISNOT: { + testcase( op==TK_IS ); + testcase( op==TK_ISNOT ); + r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free1); + r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, ®Free2); + op = (op==TK_IS) ? TK_EQ : TK_NE; + codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op, + r1, r2, dest, SQLITE_NULLEQ); + testcase( regFree1==0 ); + testcase( regFree2==0 ); + break; + } + case TK_ISNULL: + case TK_NOTNULL: { + assert( TK_ISNULL==OP_IsNull ); + assert( TK_NOTNULL==OP_NotNull ); + testcase( op==TK_ISNULL ); + testcase( op==TK_NOTNULL ); + r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free1); + sqlite3VdbeAddOp2(v, op, r1, dest); + testcase( regFree1==0 ); + break; + } + case TK_BETWEEN: { + testcase( jumpIfNull==0 ); + exprCodeBetween(pParse, pExpr, dest, 1, jumpIfNull); + break; + } +#ifndef SQLITE_OMIT_SUBQUERY + case TK_IN: { + int destIfFalse = sqlite3VdbeMakeLabel(v); + int destIfNull = jumpIfNull ? dest : destIfFalse; + sqlite3ExprCodeIN(pParse, pExpr, destIfFalse, destIfNull); + sqlite3VdbeAddOp2(v, OP_Goto, 0, dest); + sqlite3VdbeResolveLabel(v, destIfFalse); + break; + } +#endif + default: { + r1 = sqlite3ExprCodeTemp(pParse, pExpr, ®Free1); + sqlite3VdbeAddOp3(v, OP_If, r1, dest, jumpIfNull!=0); + testcase( regFree1==0 ); + testcase( jumpIfNull==0 ); + break; + } + } + sqlite3ReleaseTempReg(pParse, regFree1); + sqlite3ReleaseTempReg(pParse, regFree2); +} + +/* +** Generate code for a boolean expression such that a jump is made +** to the label "dest" if the expression is false but execution +** continues straight thru if the expression is true. +** +** If the expression evaluates to NULL (neither true nor false) then +** jump if jumpIfNull is SQLITE_JUMPIFNULL or fall through if jumpIfNull +** is 0. +*/ +void sqlite3ExprIfFalse(Parse *pParse, Expr *pExpr, int dest, int jumpIfNull){ + Vdbe *v = pParse->pVdbe; + int op = 0; + int regFree1 = 0; + int regFree2 = 0; + int r1, r2; + + assert( jumpIfNull==SQLITE_JUMPIFNULL || jumpIfNull==0 ); + if( NEVER(v==0) ) return; /* Existance of VDBE checked by caller */ + if( pExpr==0 ) return; + + /* The value of pExpr->op and op are related as follows: + ** + ** pExpr->op op + ** --------- ---------- + ** TK_ISNULL OP_NotNull + ** TK_NOTNULL OP_IsNull + ** TK_NE OP_Eq + ** TK_EQ OP_Ne + ** TK_GT OP_Le + ** TK_LE OP_Gt + ** TK_GE OP_Lt + ** TK_LT OP_Ge + ** + ** For other values of pExpr->op, op is undefined and unused. + ** The value of TK_ and OP_ constants are arranged such that we + ** can compute the mapping above using the following expression. + ** Assert()s verify that the computation is correct. + */ + op = ((pExpr->op+(TK_ISNULL&1))^1)-(TK_ISNULL&1); + + /* Verify correct alignment of TK_ and OP_ constants + */ + assert( pExpr->op!=TK_ISNULL || op==OP_NotNull ); + assert( pExpr->op!=TK_NOTNULL || op==OP_IsNull ); + assert( pExpr->op!=TK_NE || op==OP_Eq ); + assert( pExpr->op!=TK_EQ || op==OP_Ne ); + assert( pExpr->op!=TK_LT || op==OP_Ge ); + assert( pExpr->op!=TK_LE || op==OP_Gt ); + assert( pExpr->op!=TK_GT || op==OP_Le ); + assert( pExpr->op!=TK_GE || op==OP_Lt ); + + switch( pExpr->op ){ + case TK_AND: { + testcase( jumpIfNull==0 ); + sqlite3ExprIfFalse(pParse, pExpr->pLeft, dest, jumpIfNull); + sqlite3ExprIfFalse(pParse, pExpr->pRight, dest, jumpIfNull); + break; + } + case TK_OR: { + int d2 = sqlite3VdbeMakeLabel(v); + testcase( jumpIfNull==0 ); + sqlite3ExprCachePush(pParse); + sqlite3ExprIfTrue(pParse, pExpr->pLeft, d2, jumpIfNull^SQLITE_JUMPIFNULL); + sqlite3ExprIfFalse(pParse, pExpr->pRight, dest, jumpIfNull); + sqlite3VdbeResolveLabel(v, d2); + sqlite3ExprCachePop(pParse, 1); + break; + } + case TK_NOT: { + testcase( jumpIfNull==0 ); + sqlite3ExprIfTrue(pParse, pExpr->pLeft, dest, jumpIfNull); + break; + } + case TK_LT: + case TK_LE: + case TK_GT: + case TK_GE: + case TK_NE: + case TK_EQ: { + testcase( op==TK_LT ); + testcase( op==TK_LE ); + testcase( op==TK_GT ); + testcase( op==TK_GE ); + testcase( op==TK_EQ ); + testcase( op==TK_NE ); + testcase( jumpIfNull==0 ); + r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free1); + r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, ®Free2); + codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op, + r1, r2, dest, jumpIfNull); + testcase( regFree1==0 ); + testcase( regFree2==0 ); + break; + } + case TK_IS: + case TK_ISNOT: { + testcase( pExpr->op==TK_IS ); + testcase( pExpr->op==TK_ISNOT ); + r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free1); + r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, ®Free2); + op = (pExpr->op==TK_IS) ? TK_NE : TK_EQ; + codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op, + r1, r2, dest, SQLITE_NULLEQ); + testcase( regFree1==0 ); + testcase( regFree2==0 ); + break; + } + case TK_ISNULL: + case TK_NOTNULL: { + testcase( op==TK_ISNULL ); + testcase( op==TK_NOTNULL ); + r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free1); + sqlite3VdbeAddOp2(v, op, r1, dest); + testcase( regFree1==0 ); + break; + } + case TK_BETWEEN: { + testcase( jumpIfNull==0 ); + exprCodeBetween(pParse, pExpr, dest, 0, jumpIfNull); + break; + } +#ifndef SQLITE_OMIT_SUBQUERY + case TK_IN: { + if( jumpIfNull ){ + sqlite3ExprCodeIN(pParse, pExpr, dest, dest); + }else{ + int destIfNull = sqlite3VdbeMakeLabel(v); + sqlite3ExprCodeIN(pParse, pExpr, dest, destIfNull); + sqlite3VdbeResolveLabel(v, destIfNull); + } + break; + } +#endif + default: { + r1 = sqlite3ExprCodeTemp(pParse, pExpr, ®Free1); + sqlite3VdbeAddOp3(v, OP_IfNot, r1, dest, jumpIfNull!=0); + testcase( regFree1==0 ); + testcase( jumpIfNull==0 ); + break; + } + } + sqlite3ReleaseTempReg(pParse, regFree1); + sqlite3ReleaseTempReg(pParse, regFree2); +} + +/* +** Do a deep comparison of two expression trees. Return 0 if the two +** expressions are completely identical. Return 1 if they differ only +** by a COLLATE operator at the top level. Return 2 if there are differences +** other than the top-level COLLATE operator. +** +** 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){ + if( pA==0||pB==0 ){ + return pB==pA ? 0 : 2; + } + assert( !ExprHasAnyProperty(pA, EP_TokenOnly|EP_Reduced) ); + assert( !ExprHasAnyProperty(pB, EP_TokenOnly|EP_Reduced) ); + if( ExprHasProperty(pA, EP_xIsSelect) || ExprHasProperty(pB, EP_xIsSelect) ){ + return 2; + } + if( (pA->flags & EP_Distinct)!=(pB->flags & EP_Distinct) ) return 2; + if( pA->op!=pB->op ) return 2; + if( sqlite3ExprCompare(pA->pLeft, pB->pLeft) ) return 2; + if( sqlite3ExprCompare(pA->pRight, pB->pRight) ) return 2; + if( sqlite3ExprListCompare(pA->x.pList, pB->x.pList) ) return 2; + if( pA->iTable!=pB->iTable || pA->iColumn!=pB->iColumn ) return 2; + if( ExprHasProperty(pA, EP_IntValue) ){ + if( !ExprHasProperty(pB, EP_IntValue) || pA->u.iValue!=pB->u.iValue ){ + return 2; + } + }else if( pA->op!=TK_COLUMN && pA->u.zToken ){ + if( ExprHasProperty(pB, EP_IntValue) || NEVER(pB->u.zToken==0) ) return 2; + if( strcmp(pA->u.zToken,pB->u.zToken)!=0 ){ + return 2; + } + } + if( (pA->flags & EP_ExpCollate)!=(pB->flags & EP_ExpCollate) ) return 1; + if( (pA->flags & EP_ExpCollate)!=0 && pA->pColl!=pB->pColl ) return 2; + return 0; +} + +/* +** Compare two ExprList objects. Return 0 if they are identical and +** non-zero if they differ in any way. +** +** 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 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) ) return 1; + } + return 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]), + 3, + &pInfo->nColumn, + &pInfo->nColumnAlloc, + &i + ); + return i; +} + +/* +** Add a new element to the pAggInfo->aFunc[] array. Return the index of +** the new element. Return a negative number if malloc fails. +*/ +static int addAggInfoFunc(sqlite3 *db, AggInfo *pInfo){ + int i; + pInfo->aFunc = sqlite3ArrayAllocate( + db, + pInfo->aFunc, + sizeof(pInfo->aFunc[0]), + 3, + &pInfo->nFunc, + &pInfo->nFuncAlloc, + &i + ); + return i; +} + +/* +** This is 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( !ExprHasAnyProperty(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. + */ + ExprSetIrreducible(pExpr); + 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: { + /* The pNC->nDepth==0 test causes aggregate functions in subqueries + ** to be ignored */ + if( pNC->nDepth==0 ){ + /* Check to see if pExpr is a duplicate of another aggregate + ** function that is already in the pAggInfo structure + */ + struct AggInfo_func *pItem = pAggInfo->aFunc; + for(i=0; i<pAggInfo->nFunc; i++, pItem++){ + if( sqlite3ExprCompare(pItem->pExpr, pExpr)==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( !ExprHasAnyProperty(pExpr, EP_TokenOnly|EP_Reduced) ); + ExprSetIrreducible(pExpr); + pExpr->iAgg = (i16)i; + pExpr->pAggInfo = pAggInfo; + return WRC_Prune; + } + } + } + return WRC_Continue; +} +static int analyzeAggregatesInSelect(Walker *pWalker, Select *pSelect){ + NameContext *pNC = pWalker->u.pNC; + if( pNC->nDepth==0 ){ + pNC->nDepth++; + sqlite3WalkSelect(pWalker, pSelect); + pNC->nDepth--; + return WRC_Prune; + }else{ + return WRC_Continue; + } +} + +/* +** Analyze the given expression looking for aggregate functions and +** for variables that need to be added to the pParse->aAgg[] array. +** Make additional entries to the pParse->aAgg[] array as necessary. +** +** This routine should only be called after the expression has been +** analyzed by sqlite3ResolveExprNames(). +*/ +void sqlite3ExprAnalyzeAggregates(NameContext *pNC, Expr *pExpr){ + Walker w; + w.xExprCallback = analyzeAggregate; + w.xSelectCallback = analyzeAggregatesInSelect; + w.u.pNC = pNC; + assert( pNC->pSrcList!=0 ); + sqlite3WalkExpr(&w, pExpr); +} + +/* +** Call sqlite3ExprAnalyzeAggregates() for every expression in an +** expression list. Return the number of errors. +** +** If an error is found, the analysis is cut short. +*/ +void sqlite3ExprAnalyzeAggList(NameContext *pNC, ExprList *pList){ + struct ExprList_item *pItem; + int i; + if( pList ){ + for(pItem=pList->a, i=0; i<pList->nExpr; i++, pItem++){ + sqlite3ExprAnalyzeAggregates(pNC, pItem->pExpr); + } + } +} + +/* +** Allocate a single new register for use to hold some intermediate result. +*/ +int sqlite3GetTempReg(Parse *pParse){ + if( pParse->nTempReg==0 ){ + return ++pParse->nMem; + } + return pParse->aTempReg[--pParse->nTempReg]; +} + +/* +** Deallocate a register, making available for reuse for some other +** purpose. +** +** If a register is currently being used by the column cache, then +** the dallocation is deferred until the column cache line that uses +** the register becomes stale. +*/ +void sqlite3ReleaseTempReg(Parse *pParse, int iReg){ + if( iReg && pParse->nTempReg<ArraySize(pParse->aTempReg) ){ + int i; + struct yColCache *p; + for(i=0, p=pParse->aColCache; i<SQLITE_N_COLCACHE; i++, p++){ + if( p->iReg==iReg ){ + p->tempReg = 1; + return; + } + } + pParse->aTempReg[pParse->nTempReg++] = iReg; + } +} + +/* +** Allocate or deallocate a block of nReg consecutive registers +*/ +int sqlite3GetTempRange(Parse *pParse, int nReg){ + int i, n; + i = pParse->iRangeReg; + n = pParse->nRangeReg; + if( nReg<=n ){ + assert( !usedAsColumnCache(pParse, i, i+n-1) ); + pParse->iRangeReg += nReg; + pParse->nRangeReg -= nReg; + }else{ + i = pParse->nMem+1; + pParse->nMem += nReg; + } + return i; +} +void sqlite3ReleaseTempRange(Parse *pParse, int iReg, int nReg){ + sqlite3ExprCacheRemove(pParse, iReg, nReg); + if( nReg>pParse->nRangeReg ){ + pParse->nRangeReg = nReg; + pParse->iRangeReg = iReg; + } +} |