diff options
| author | mpcomplete@google.com <mpcomplete@google.com@0039d316-1c4b-4281-b951-d872f2087c98> | 2009-01-06 22:39:41 +0000 |
|---|---|---|
| committer | mpcomplete@google.com <mpcomplete@google.com@0039d316-1c4b-4281-b951-d872f2087c98> | 2009-01-06 22:39:41 +0000 |
| commit | 586381f8db3497c24c11f96234f1879b34e74bc7 (patch) | |
| tree | 99f7d18350289b135ef6dd5c161baba8bce668a3 /third_party/sqlite/src/expr.c | |
| parent | 6e3b12ff2cbbe8c481f986c8f0dd230bb50add2a (diff) | |
| download | chromium_src-586381f8db3497c24c11f96234f1879b34e74bc7.zip chromium_src-586381f8db3497c24c11f96234f1879b34e74bc7.tar.gz chromium_src-586381f8db3497c24c11f96234f1879b34e74bc7.tar.bz2 | |
Upgrade our sqlite to 3.6.1, with the local changes made by Gears. I'm
checking in the full sqlite tree to make upstream merges easier. This means
we'll have generated sources split out from the originals.
One important change this makes is that "BEGIN" now defaults to "BEGIN
IMMEDIATE" rather than "BEGIN DEFERRED". This doesn't affect us because we
don't use unqualified BEGIN statements.
The full CL is too big for Rietveld. I'm splitting it into 2. This one is
reviewable. The other CL is just a fresh drop of:
//depot/googleclient/gears/opensource/third_party/sqlite_google
Review URL: http://codereview.chromium.org/15067
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@7623 0039d316-1c4b-4281-b951-d872f2087c98
Diffstat (limited to 'third_party/sqlite/src/expr.c')
| -rwxr-xr-x | third_party/sqlite/src/expr.c | 3586 |
1 files changed, 3586 insertions, 0 deletions
diff --git a/third_party/sqlite/src/expr.c b/third_party/sqlite/src/expr.c new file mode 100755 index 0000000..e8d8a1e --- /dev/null +++ b/third_party/sqlite/src/expr.c @@ -0,0 +1,3586 @@ +/* +** 2001 September 15 +** +** The author disclaims copyright to this source code. In place of +** a legal notice, here is a blessing: +** +** May you do good and not evil. +** May you find forgiveness for yourself and forgive others. +** May you share freely, never taking more than you give. +** +************************************************************************* +** This file contains routines used for analyzing expressions and +** for generating VDBE code that evaluates expressions in SQLite. +** +** $Id: expr.c,v 1.387 2008/07/28 19:34:53 drh Exp $ +*/ +#include "sqliteInt.h" +#include <ctype.h> + +/* +** Return the 'affinity' of the expression pExpr if any. +** +** If pExpr is a column, a reference to a column via an 'AS' alias, +** or a sub-select with a column as the return value, then the +** affinity of that column is returned. Otherwise, 0x00 is returned, +** indicating no affinity for the expression. +** +** i.e. the WHERE clause expresssions in the following statements all +** have an affinity: +** +** CREATE TABLE t1(a); +** SELECT * FROM t1 WHERE a; +** SELECT a AS b FROM t1 WHERE b; +** SELECT * FROM t1 WHERE (select a from t1); +*/ +char sqlite3ExprAffinity(Expr *pExpr){ + int op = pExpr->op; + if( op==TK_SELECT ){ + return sqlite3ExprAffinity(pExpr->pSelect->pEList->a[0].pExpr); + } +#ifndef SQLITE_OMIT_CAST + if( op==TK_CAST ){ + return sqlite3AffinityType(&pExpr->token); + } +#endif + return pExpr->affinity; +} + +/* +** Set the collating sequence for expression pExpr to be the collating +** sequence named by pToken. Return a pointer to the revised expression. +** The collating sequence is marked as "explicit" using the EP_ExpCollate +** flag. An explicit collating sequence will override implicit +** collating sequences. +*/ +Expr *sqlite3ExprSetColl(Parse *pParse, Expr *pExpr, Token *pName){ + char *zColl = 0; /* Dequoted name of collation sequence */ + CollSeq *pColl; + sqlite3 *db = pParse->db; + zColl = sqlite3NameFromToken(db, pName); + if( pExpr && zColl ){ + pColl = sqlite3LocateCollSeq(pParse, zColl, -1); + if( pColl ){ + pExpr->pColl = pColl; + pExpr->flags |= EP_ExpCollate; + } + } + sqlite3DbFree(db, zColl); + return pExpr; +} + +/* +** Return the default collation sequence for the expression pExpr. If +** there is no default collation type, return 0. +*/ +CollSeq *sqlite3ExprCollSeq(Parse *pParse, Expr *pExpr){ + CollSeq *pColl = 0; + if( pExpr ){ + int op; + pColl = pExpr->pColl; + op = pExpr->op; + if( (op==TK_CAST || op==TK_UPLUS) && !pColl ){ + return sqlite3ExprCollSeq(pParse, pExpr->pLeft); + } + } + if( sqlite3CheckCollSeq(pParse, pColl) ){ + pColl = 0; + } + return pColl; +} + +/* +** pExpr is an operand of a comparison operator. aff2 is the +** type affinity of the other operand. This routine returns the +** type affinity that should be used for the comparison operator. +*/ +char sqlite3CompareAffinity(Expr *pExpr, char aff2){ + char aff1 = sqlite3ExprAffinity(pExpr); + if( aff1 && aff2 ){ + /* Both sides of the comparison are columns. If one has numeric + ** affinity, use that. Otherwise use no affinity. + */ + if( sqlite3IsNumericAffinity(aff1) || sqlite3IsNumericAffinity(aff2) ){ + return SQLITE_AFF_NUMERIC; + }else{ + return SQLITE_AFF_NONE; + } + }else if( !aff1 && !aff2 ){ + /* Neither side of the comparison is a column. Compare the + ** results directly. + */ + return SQLITE_AFF_NONE; + }else{ + /* One side is a column, the other is not. Use the columns affinity. */ + assert( aff1==0 || aff2==0 ); + return (aff1 + aff2); + } +} + +/* +** pExpr is a comparison operator. Return the type affinity that should +** be applied to both operands prior to doing the comparison. +*/ +static char comparisonAffinity(Expr *pExpr){ + char aff; + assert( pExpr->op==TK_EQ || pExpr->op==TK_IN || pExpr->op==TK_LT || + pExpr->op==TK_GT || pExpr->op==TK_GE || pExpr->op==TK_LE || + pExpr->op==TK_NE ); + assert( pExpr->pLeft ); + aff = sqlite3ExprAffinity(pExpr->pLeft); + if( pExpr->pRight ){ + aff = sqlite3CompareAffinity(pExpr->pRight, aff); + } + else if( pExpr->pSelect ){ + aff = sqlite3CompareAffinity(pExpr->pSelect->pEList->a[0].pExpr, aff); + } + else if( !aff ){ + aff = SQLITE_AFF_NONE; + } + return aff; +} + +/* +** pExpr is a comparison expression, eg. '=', '<', IN(...) etc. +** idx_affinity is the affinity of an indexed column. Return true +** if the index with affinity idx_affinity may be used to implement +** the comparison in pExpr. +*/ +int sqlite3IndexAffinityOk(Expr *pExpr, char idx_affinity){ + char aff = comparisonAffinity(pExpr); + switch( aff ){ + case SQLITE_AFF_NONE: + return 1; + case SQLITE_AFF_TEXT: + return idx_affinity==SQLITE_AFF_TEXT; + default: + return sqlite3IsNumericAffinity(idx_affinity); + } +} + +/* +** Return the P5 value that should be used for a binary comparison +** opcode (OP_Eq, OP_Ge etc.) used to compare pExpr1 and pExpr2. +*/ +static u8 binaryCompareP5(Expr *pExpr1, Expr *pExpr2, int jumpIfNull){ + u8 aff = (char)sqlite3ExprAffinity(pExpr2); + aff = sqlite3CompareAffinity(pExpr1, aff) | jumpIfNull; + return aff; +} + +/* +** Return a pointer to the collation sequence that should be used by +** a binary comparison operator comparing pLeft and pRight. +** +** If the left hand expression has a collating sequence type, then it is +** used. Otherwise the collation sequence for the right hand expression +** is used, or the default (BINARY) if neither expression has a collating +** type. +** +** Argument pRight (but not pLeft) may be a null pointer. In this case, +** it is not considered. +*/ +CollSeq *sqlite3BinaryCompareCollSeq( + Parse *pParse, + Expr *pLeft, + Expr *pRight +){ + CollSeq *pColl; + assert( pLeft ); + if( pLeft->flags & EP_ExpCollate ){ + assert( pLeft->pColl ); + pColl = pLeft->pColl; + }else if( pRight && pRight->flags & EP_ExpCollate ){ + assert( pRight->pColl ); + pColl = pRight->pColl; + }else{ + pColl = sqlite3ExprCollSeq(pParse, pLeft); + if( !pColl ){ + pColl = sqlite3ExprCollSeq(pParse, pRight); + } + } + return pColl; +} + +/* +** Generate the operands for a comparison operation. Before +** generating the code for each operand, set the EP_AnyAff +** flag on the expression so that it will be able to used a +** cached column value that has previously undergone an +** affinity change. +*/ +static void codeCompareOperands( + Parse *pParse, /* Parsing and code generating context */ + Expr *pLeft, /* The left operand */ + int *pRegLeft, /* Register where left operand is stored */ + int *pFreeLeft, /* Free this register when done */ + Expr *pRight, /* The right operand */ + int *pRegRight, /* Register where right operand is stored */ + int *pFreeRight /* Write temp register for right operand there */ +){ + while( pLeft->op==TK_UPLUS ) pLeft = pLeft->pLeft; + pLeft->flags |= EP_AnyAff; + *pRegLeft = sqlite3ExprCodeTemp(pParse, pLeft, pFreeLeft); + while( pRight->op==TK_UPLUS ) pRight = pRight->pLeft; + pRight->flags |= EP_AnyAff; + *pRegRight = sqlite3ExprCodeTemp(pParse, pRight, pFreeRight); +} + +/* +** Generate code for a comparison operator. +*/ +static int codeCompare( + Parse *pParse, /* The parsing (and code generating) context */ + Expr *pLeft, /* The left operand */ + Expr *pRight, /* The right operand */ + int opcode, /* The comparison opcode */ + int in1, int in2, /* Register holding operands */ + int dest, /* Jump here if true. */ + int jumpIfNull /* If true, jump if either operand is NULL */ +){ + int p5; + int addr; + CollSeq *p4; + + p4 = sqlite3BinaryCompareCollSeq(pParse, pLeft, pRight); + p5 = binaryCompareP5(pLeft, pRight, jumpIfNull); + addr = sqlite3VdbeAddOp4(pParse->pVdbe, opcode, in2, dest, in1, + (void*)p4, P4_COLLSEQ); + sqlite3VdbeChangeP5(pParse->pVdbe, p5); + if( (p5 & SQLITE_AFF_MASK)!=SQLITE_AFF_NONE ){ + sqlite3ExprCacheAffinityChange(pParse, in1, 1); + sqlite3ExprCacheAffinityChange(pParse, in2, 1); + } + return addr; +} + +#if SQLITE_MAX_EXPR_DEPTH>0 +/* +** Check that argument nHeight is less than or equal to the maximum +** expression depth allowed. If it is not, leave an error message in +** pParse. +*/ +static int checkExprHeight(Parse *pParse, int nHeight){ + int rc = SQLITE_OK; + int mxHeight = pParse->db->aLimit[SQLITE_LIMIT_EXPR_DEPTH]; + if( nHeight>mxHeight ){ + sqlite3ErrorMsg(pParse, + "Expression tree is too large (maximum depth %d)", mxHeight + ); + rc = SQLITE_ERROR; + } + return rc; +} + +/* The following three functions, heightOfExpr(), heightOfExprList() +** and heightOfSelect(), are used to determine the maximum height +** of any expression tree referenced by the structure passed as the +** first argument. +** +** If this maximum height is greater than the current value pointed +** to by pnHeight, the second parameter, then set *pnHeight to that +** value. +*/ +static void heightOfExpr(Expr *p, int *pnHeight){ + if( p ){ + if( p->nHeight>*pnHeight ){ + *pnHeight = p->nHeight; + } + } +} +static void heightOfExprList(ExprList *p, int *pnHeight){ + if( p ){ + int i; + for(i=0; i<p->nExpr; i++){ + heightOfExpr(p->a[i].pExpr, pnHeight); + } + } +} +static void heightOfSelect(Select *p, int *pnHeight){ + if( p ){ + heightOfExpr(p->pWhere, pnHeight); + heightOfExpr(p->pHaving, pnHeight); + heightOfExpr(p->pLimit, pnHeight); + heightOfExpr(p->pOffset, pnHeight); + heightOfExprList(p->pEList, pnHeight); + heightOfExprList(p->pGroupBy, pnHeight); + heightOfExprList(p->pOrderBy, pnHeight); + heightOfSelect(p->pPrior, pnHeight); + } +} + +/* +** Set the Expr.nHeight variable in the structure passed as an +** argument. An expression with no children, Expr.pList or +** Expr.pSelect member has a height of 1. Any other expression +** has a height equal to the maximum height of any other +** referenced Expr plus one. +*/ +static void exprSetHeight(Expr *p){ + int nHeight = 0; + heightOfExpr(p->pLeft, &nHeight); + heightOfExpr(p->pRight, &nHeight); + heightOfExprList(p->pList, &nHeight); + heightOfSelect(p->pSelect, &nHeight); + p->nHeight = nHeight + 1; +} + +/* +** Set the Expr.nHeight variable using the exprSetHeight() function. If +** the height is greater than the maximum allowed expression depth, +** leave an error in pParse. +*/ +void sqlite3ExprSetHeight(Parse *pParse, Expr *p){ + exprSetHeight(p); + checkExprHeight(pParse, p->nHeight); +} + +/* +** Return the maximum height of any expression tree referenced +** by the select statement passed as an argument. +*/ +int sqlite3SelectExprHeight(Select *p){ + int nHeight = 0; + heightOfSelect(p, &nHeight); + return nHeight; +} +#else + #define checkExprHeight(x,y) + #define exprSetHeight(y) +#endif /* SQLITE_MAX_EXPR_DEPTH>0 */ + +/* +** Construct a new expression node and return a pointer to it. Memory +** for this node is obtained from sqlite3_malloc(). The calling function +** is responsible for making sure the node eventually gets freed. +*/ +Expr *sqlite3Expr( + sqlite3 *db, /* Handle for sqlite3DbMallocZero() (may be null) */ + int op, /* Expression opcode */ + Expr *pLeft, /* Left operand */ + Expr *pRight, /* Right operand */ + const Token *pToken /* Argument token */ +){ + Expr *pNew; + pNew = sqlite3DbMallocZero(db, sizeof(Expr)); + if( pNew==0 ){ + /* When malloc fails, delete pLeft and pRight. Expressions passed to + ** this function must always be allocated with sqlite3Expr() for this + ** reason. + */ + sqlite3ExprDelete(db, pLeft); + sqlite3ExprDelete(db, pRight); + return 0; + } + pNew->op = op; + pNew->pLeft = pLeft; + pNew->pRight = pRight; + pNew->iAgg = -1; + pNew->span.z = (u8*)""; + if( pToken ){ + assert( pToken->dyn==0 ); + pNew->span = pNew->token = *pToken; + }else if( pLeft ){ + if( pRight ){ + if( pRight->span.dyn==0 && pLeft->span.dyn==0 ){ + sqlite3ExprSpan(pNew, &pLeft->span, &pRight->span); + } + if( pRight->flags & EP_ExpCollate ){ + pNew->flags |= EP_ExpCollate; + pNew->pColl = pRight->pColl; + } + } + if( pLeft->flags & EP_ExpCollate ){ + pNew->flags |= EP_ExpCollate; + pNew->pColl = pLeft->pColl; + } + } + + exprSetHeight(pNew); + return pNew; +} + +/* +** Works like sqlite3Expr() except that it takes an extra Parse* +** argument and notifies the associated connection object if malloc fails. +*/ +Expr *sqlite3PExpr( + Parse *pParse, /* Parsing context */ + int op, /* Expression opcode */ + Expr *pLeft, /* Left operand */ + Expr *pRight, /* Right operand */ + const Token *pToken /* Argument token */ +){ + Expr *p = sqlite3Expr(pParse->db, op, pLeft, pRight, pToken); + if( p ){ + checkExprHeight(pParse, p->nHeight); + } + return p; +} + +/* +** When doing a nested parse, you can include terms in an expression +** that look like this: #1 #2 ... These terms refer to registers +** in the virtual machine. #N is the N-th register. +** +** This routine is called by the parser to deal with on of those terms. +** It immediately generates code to store the value in a memory location. +** The returns an expression that will code to extract the value from +** that memory location as needed. +*/ +Expr *sqlite3RegisterExpr(Parse *pParse, Token *pToken){ + Vdbe *v = pParse->pVdbe; + Expr *p; + if( pParse->nested==0 ){ + sqlite3ErrorMsg(pParse, "near \"%T\": syntax error", pToken); + return sqlite3PExpr(pParse, TK_NULL, 0, 0, 0); + } + if( v==0 ) return 0; + p = sqlite3PExpr(pParse, TK_REGISTER, 0, 0, pToken); + if( p==0 ){ + return 0; /* Malloc failed */ + } + p->iTable = atoi((char*)&pToken->z[1]); + return p; +} + +/* +** Join two expressions using an AND operator. If either expression is +** NULL, then just return the other expression. +*/ +Expr *sqlite3ExprAnd(sqlite3 *db, Expr *pLeft, Expr *pRight){ + if( pLeft==0 ){ + return pRight; + }else if( pRight==0 ){ + return pLeft; + }else{ + return sqlite3Expr(db, TK_AND, pLeft, pRight, 0); + } +} + +/* +** Set the Expr.span field of the given expression to span all +** text between the two given tokens. Both tokens must be pointing +** at the same string. +*/ +void sqlite3ExprSpan(Expr *pExpr, Token *pLeft, Token *pRight){ + assert( pRight!=0 ); + assert( pLeft!=0 ); + if( pExpr ){ + pExpr->span.z = pLeft->z; + pExpr->span.n = pRight->n + (pRight->z - pLeft->z); + } +} + +/* +** Construct a new expression node for a function with multiple +** arguments. +*/ +Expr *sqlite3ExprFunction(Parse *pParse, ExprList *pList, Token *pToken){ + Expr *pNew; + sqlite3 *db = pParse->db; + assert( pToken ); + pNew = sqlite3DbMallocZero(db, sizeof(Expr) ); + if( pNew==0 ){ + sqlite3ExprListDelete(db, pList); /* Avoid leaking memory when malloc fails */ + return 0; + } + pNew->op = TK_FUNCTION; + pNew->pList = pList; + assert( pToken->dyn==0 ); + pNew->token = *pToken; + pNew->span = pNew->token; + + sqlite3ExprSetHeight(pParse, pNew); + return pNew; +} + +/* +** Assign a variable number to an expression that encodes a wildcard +** in the original SQL statement. +** +** Wildcards consisting of a single "?" are assigned the next sequential +** variable number. +** +** Wildcards of the form "?nnn" are assigned the number "nnn". We make +** sure "nnn" is not too be to avoid a denial of service attack when +** the SQL statement comes from an external source. +** +** Wildcards of the form ":aaa" or "$aaa" are assigned the same number +** as the previous instance of the same wildcard. Or if this is the first +** instance of the wildcard, the next sequenial variable number is +** assigned. +*/ +void sqlite3ExprAssignVarNumber(Parse *pParse, Expr *pExpr){ + Token *pToken; + sqlite3 *db = pParse->db; + + if( pExpr==0 ) return; + pToken = &pExpr->token; + assert( pToken->n>=1 ); + assert( pToken->z!=0 ); + assert( pToken->z[0]!=0 ); + if( pToken->n==1 ){ + /* Wildcard of the form "?". Assign the next variable number */ + pExpr->iTable = ++pParse->nVar; + }else if( pToken->z[0]=='?' ){ + /* Wildcard of the form "?nnn". Convert "nnn" to an integer and + ** use it as the variable number */ + int i; + pExpr->iTable = i = atoi((char*)&pToken->z[1]); + testcase( i==0 ); + testcase( i==1 ); + testcase( i==db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER]-1 ); + testcase( i==db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER] ); + if( i<1 || i>db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER] ){ + sqlite3ErrorMsg(pParse, "variable number must be between ?1 and ?%d", + db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER]); + } + if( i>pParse->nVar ){ + pParse->nVar = i; + } + }else{ + /* Wildcards of the form ":aaa" or "$aaa". Reuse the same variable + ** number as the prior appearance of the same name, or if the name + ** has never appeared before, reuse the same variable number + */ + int i, n; + n = pToken->n; + for(i=0; i<pParse->nVarExpr; i++){ + Expr *pE; + if( (pE = pParse->apVarExpr[i])!=0 + && pE->token.n==n + && memcmp(pE->token.z, pToken->z, n)==0 ){ + pExpr->iTable = pE->iTable; + break; + } + } + if( i>=pParse->nVarExpr ){ + pExpr->iTable = ++pParse->nVar; + if( pParse->nVarExpr>=pParse->nVarExprAlloc-1 ){ + pParse->nVarExprAlloc += pParse->nVarExprAlloc + 10; + pParse->apVarExpr = + sqlite3DbReallocOrFree( + db, + pParse->apVarExpr, + pParse->nVarExprAlloc*sizeof(pParse->apVarExpr[0]) + ); + } + if( !db->mallocFailed ){ + assert( pParse->apVarExpr!=0 ); + pParse->apVarExpr[pParse->nVarExpr++] = pExpr; + } + } + } + if( !pParse->nErr && pParse->nVar>db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER] ){ + sqlite3ErrorMsg(pParse, "too many SQL variables"); + } +} + +/* +** Recursively delete an expression tree. +*/ +void sqlite3ExprDelete(sqlite3 *db, Expr *p){ + if( p==0 ) return; + if( p->span.dyn ) sqlite3DbFree(db, (char*)p->span.z); + if( p->token.dyn ) sqlite3DbFree(db, (char*)p->token.z); + sqlite3ExprDelete(db, p->pLeft); + sqlite3ExprDelete(db, p->pRight); + sqlite3ExprListDelete(db, p->pList); + sqlite3SelectDelete(db, p->pSelect); + sqlite3DbFree(db, p); +} + +/* +** The Expr.token field might be a string literal that is quoted. +** If so, remove the quotation marks. +*/ +void sqlite3DequoteExpr(sqlite3 *db, Expr *p){ + if( ExprHasAnyProperty(p, EP_Dequoted) ){ + return; + } + ExprSetProperty(p, EP_Dequoted); + if( p->token.dyn==0 ){ + sqlite3TokenCopy(db, &p->token, &p->token); + } + sqlite3Dequote((char*)p->token.z); +} + + +/* +** The following group of routines make deep copies of expressions, +** expression lists, ID lists, and select statements. The copies can +** be deleted (by being passed to their respective ...Delete() routines) +** without effecting the originals. +** +** The expression list, ID, and source lists return by sqlite3ExprListDup(), +** sqlite3IdListDup(), and sqlite3SrcListDup() can not be further expanded +** by subsequent calls to sqlite*ListAppend() routines. +** +** Any tables that the SrcList might point to are not duplicated. +*/ +Expr *sqlite3ExprDup(sqlite3 *db, Expr *p){ + Expr *pNew; + if( p==0 ) return 0; + pNew = sqlite3DbMallocRaw(db, sizeof(*p) ); + if( pNew==0 ) return 0; + memcpy(pNew, p, sizeof(*pNew)); + if( p->token.z!=0 ){ + pNew->token.z = (u8*)sqlite3DbStrNDup(db, (char*)p->token.z, p->token.n); + pNew->token.dyn = 1; + }else{ + assert( pNew->token.z==0 ); + } + pNew->span.z = 0; + pNew->pLeft = sqlite3ExprDup(db, p->pLeft); + pNew->pRight = sqlite3ExprDup(db, p->pRight); + pNew->pList = sqlite3ExprListDup(db, p->pList); + pNew->pSelect = sqlite3SelectDup(db, p->pSelect); + return pNew; +} +void sqlite3TokenCopy(sqlite3 *db, Token *pTo, Token *pFrom){ + if( pTo->dyn ) sqlite3DbFree(db, (char*)pTo->z); + if( pFrom->z ){ + pTo->n = pFrom->n; + pTo->z = (u8*)sqlite3DbStrNDup(db, (char*)pFrom->z, pFrom->n); + pTo->dyn = 1; + }else{ + pTo->z = 0; + } +} +ExprList *sqlite3ExprListDup(sqlite3 *db, ExprList *p){ + ExprList *pNew; + struct ExprList_item *pItem, *pOldItem; + int i; + if( p==0 ) return 0; + pNew = sqlite3DbMallocRaw(db, sizeof(*pNew) ); + if( pNew==0 ) return 0; + pNew->iECursor = 0; + pNew->nExpr = pNew->nAlloc = p->nExpr; + pNew->a = pItem = sqlite3DbMallocRaw(db, p->nExpr*sizeof(p->a[0]) ); + if( pItem==0 ){ + sqlite3DbFree(db, pNew); + return 0; + } + pOldItem = p->a; + for(i=0; i<p->nExpr; i++, pItem++, pOldItem++){ + Expr *pNewExpr, *pOldExpr; + pItem->pExpr = pNewExpr = sqlite3ExprDup(db, pOldExpr = pOldItem->pExpr); + if( pOldExpr->span.z!=0 && pNewExpr ){ + /* Always make a copy of the span for top-level expressions in the + ** expression list. The logic in SELECT processing that determines + ** the names of columns in the result set needs this information */ + sqlite3TokenCopy(db, &pNewExpr->span, &pOldExpr->span); + } + assert( pNewExpr==0 || pNewExpr->span.z!=0 + || pOldExpr->span.z==0 + || db->mallocFailed ); + pItem->zName = sqlite3DbStrDup(db, pOldItem->zName); + pItem->sortOrder = pOldItem->sortOrder; + pItem->isAgg = pOldItem->isAgg; + pItem->done = 0; + } + return pNew; +} + +/* +** If cursors, triggers, views and subqueries are all omitted from +** the build, then none of the following routines, except for +** sqlite3SelectDup(), can be called. sqlite3SelectDup() is sometimes +** called with a NULL argument. +*/ +#if !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_TRIGGER) \ + || !defined(SQLITE_OMIT_SUBQUERY) +SrcList *sqlite3SrcListDup(sqlite3 *db, SrcList *p){ + SrcList *pNew; + int i; + int nByte; + if( p==0 ) return 0; + nByte = sizeof(*p) + (p->nSrc>0 ? sizeof(p->a[0]) * (p->nSrc-1) : 0); + pNew = sqlite3DbMallocRaw(db, nByte ); + if( pNew==0 ) return 0; + pNew->nSrc = pNew->nAlloc = p->nSrc; + for(i=0; i<p->nSrc; i++){ + struct SrcList_item *pNewItem = &pNew->a[i]; + struct SrcList_item *pOldItem = &p->a[i]; + Table *pTab; + pNewItem->zDatabase = sqlite3DbStrDup(db, pOldItem->zDatabase); + pNewItem->zName = sqlite3DbStrDup(db, pOldItem->zName); + pNewItem->zAlias = sqlite3DbStrDup(db, pOldItem->zAlias); + pNewItem->jointype = pOldItem->jointype; + pNewItem->iCursor = pOldItem->iCursor; + pNewItem->isPopulated = pOldItem->isPopulated; + pTab = pNewItem->pTab = pOldItem->pTab; + if( pTab ){ + pTab->nRef++; + } + pNewItem->pSelect = sqlite3SelectDup(db, pOldItem->pSelect); + pNewItem->pOn = sqlite3ExprDup(db, pOldItem->pOn); + pNewItem->pUsing = sqlite3IdListDup(db, pOldItem->pUsing); + pNewItem->colUsed = pOldItem->colUsed; + } + return pNew; +} +IdList *sqlite3IdListDup(sqlite3 *db, IdList *p){ + IdList *pNew; + int i; + if( p==0 ) return 0; + pNew = sqlite3DbMallocRaw(db, sizeof(*pNew) ); + if( pNew==0 ) return 0; + pNew->nId = pNew->nAlloc = p->nId; + pNew->a = sqlite3DbMallocRaw(db, p->nId*sizeof(p->a[0]) ); + if( pNew->a==0 ){ + sqlite3DbFree(db, pNew); + return 0; + } + for(i=0; i<p->nId; i++){ + struct IdList_item *pNewItem = &pNew->a[i]; + struct IdList_item *pOldItem = &p->a[i]; + pNewItem->zName = sqlite3DbStrDup(db, pOldItem->zName); + pNewItem->idx = pOldItem->idx; + } + return pNew; +} +Select *sqlite3SelectDup(sqlite3 *db, Select *p){ + Select *pNew; + if( p==0 ) return 0; + pNew = sqlite3DbMallocRaw(db, sizeof(*p) ); + if( pNew==0 ) return 0; + pNew->isDistinct = p->isDistinct; + pNew->pEList = sqlite3ExprListDup(db, p->pEList); + pNew->pSrc = sqlite3SrcListDup(db, p->pSrc); + pNew->pWhere = sqlite3ExprDup(db, p->pWhere); + pNew->pGroupBy = sqlite3ExprListDup(db, p->pGroupBy); + pNew->pHaving = sqlite3ExprDup(db, p->pHaving); + pNew->pOrderBy = sqlite3ExprListDup(db, p->pOrderBy); + pNew->op = p->op; + pNew->pPrior = sqlite3SelectDup(db, p->pPrior); + pNew->pLimit = sqlite3ExprDup(db, p->pLimit); + pNew->pOffset = sqlite3ExprDup(db, p->pOffset); + pNew->iLimit = 0; + pNew->iOffset = 0; + pNew->isResolved = p->isResolved; + pNew->isAgg = p->isAgg; + pNew->usesEphm = 0; + pNew->disallowOrderBy = 0; + pNew->pRightmost = 0; + pNew->addrOpenEphm[0] = -1; + pNew->addrOpenEphm[1] = -1; + pNew->addrOpenEphm[2] = -1; + return pNew; +} +#else +Select *sqlite3SelectDup(sqlite3 *db, Select *p){ + assert( p==0 ); + return 0; +} +#endif + + +/* +** Add a new element to the end of an expression list. If pList is +** initially NULL, then create a new expression list. +*/ +ExprList *sqlite3ExprListAppend( + Parse *pParse, /* Parsing context */ + ExprList *pList, /* List to which to append. Might be NULL */ + Expr *pExpr, /* Expression to be appended */ + Token *pName /* AS keyword for the expression */ +){ + sqlite3 *db = pParse->db; + if( pList==0 ){ + pList = sqlite3DbMallocZero(db, sizeof(ExprList) ); + if( pList==0 ){ + goto no_mem; + } + assert( pList->nAlloc==0 ); + } + if( pList->nAlloc<=pList->nExpr ){ + struct ExprList_item *a; + int n = pList->nAlloc*2 + 4; + a = sqlite3DbRealloc(db, pList->a, n*sizeof(pList->a[0])); + if( a==0 ){ + goto no_mem; + } + pList->a = a; + pList->nAlloc = n; + } + assert( pList->a!=0 ); + if( pExpr || pName ){ + struct ExprList_item *pItem = &pList->a[pList->nExpr++]; + memset(pItem, 0, sizeof(*pItem)); + pItem->zName = sqlite3NameFromToken(db, pName); + pItem->pExpr = pExpr; + } + return pList; + +no_mem: + /* Avoid leaking memory if malloc has failed. */ + sqlite3ExprDelete(db, pExpr); + sqlite3ExprListDelete(db, pList); + return 0; +} + +/* +** If the expression list pEList contains more than iLimit elements, +** leave an error message in pParse. +*/ +void sqlite3ExprListCheckLength( + Parse *pParse, + ExprList *pEList, + const char *zObject +){ + int mx = pParse->db->aLimit[SQLITE_LIMIT_COLUMN]; + testcase( pEList && pEList->nExpr==mx ); + testcase( pEList && pEList->nExpr==mx+1 ); + if( pEList && pEList->nExpr>mx ){ + sqlite3ErrorMsg(pParse, "too many columns in %s", zObject); + } +} + +/* +** Delete an entire expression list. +*/ +void sqlite3ExprListDelete(sqlite3 *db, ExprList *pList){ + int i; + struct ExprList_item *pItem; + if( pList==0 ) return; + assert( pList->a!=0 || (pList->nExpr==0 && pList->nAlloc==0) ); + assert( pList->nExpr<=pList->nAlloc ); + for(pItem=pList->a, i=0; i<pList->nExpr; i++, pItem++){ + sqlite3ExprDelete(db, pItem->pExpr); + sqlite3DbFree(db, pItem->zName); + } + sqlite3DbFree(db, pList->a); + sqlite3DbFree(db, pList); +} + +/* +** Walk an expression tree. Call xFunc for each node visited. xFunc +** is called on the node before xFunc is called on the nodes children. +** +** The return value from xFunc determines whether the tree walk continues. +** 0 means continue walking the tree. 1 means do not walk children +** of the current node but continue with siblings. 2 means abandon +** the tree walk completely. +** +** The return value from this routine is 1 to abandon the tree walk +** and 0 to continue. +** +** NOTICE: This routine does *not* descend into subqueries. +*/ +static int walkExprList(ExprList *, int (*)(void *, Expr*), void *); +static int walkExprTree(Expr *pExpr, int (*xFunc)(void*,Expr*), void *pArg){ + int rc; + if( pExpr==0 ) return 0; + rc = (*xFunc)(pArg, pExpr); + if( rc==0 ){ + if( walkExprTree(pExpr->pLeft, xFunc, pArg) ) return 1; + if( walkExprTree(pExpr->pRight, xFunc, pArg) ) return 1; + if( walkExprList(pExpr->pList, xFunc, pArg) ) return 1; + } + return rc>1; +} + +/* +** Call walkExprTree() for every expression in list p. +*/ +static int walkExprList(ExprList *p, int (*xFunc)(void *, Expr*), void *pArg){ + int i; + struct ExprList_item *pItem; + if( !p ) return 0; + for(i=p->nExpr, pItem=p->a; i>0; i--, pItem++){ + if( walkExprTree(pItem->pExpr, xFunc, pArg) ) return 1; + } + return 0; +} + +/* +** Call walkExprTree() for every expression in Select p, not including +** expressions that are part of sub-selects in any FROM clause or the LIMIT +** or OFFSET expressions.. +*/ +static int walkSelectExpr(Select *p, int (*xFunc)(void *, Expr*), void *pArg){ + walkExprList(p->pEList, xFunc, pArg); + walkExprTree(p->pWhere, xFunc, pArg); + walkExprList(p->pGroupBy, xFunc, pArg); + walkExprTree(p->pHaving, xFunc, pArg); + walkExprList(p->pOrderBy, xFunc, pArg); + if( p->pPrior ){ + walkSelectExpr(p->pPrior, xFunc, pArg); + } + return 0; +} + + +/* +** This routine is designed as an xFunc for walkExprTree(). +** +** pArg is really a pointer to an integer. If we can tell by looking +** at pExpr that the expression that contains pExpr is not a constant +** expression, then set *pArg to 0 and return 2 to abandon the tree walk. +** If pExpr does does not disqualify the expression from being a constant +** then do nothing. +** +** After walking the whole tree, if no nodes are found that disqualify +** the expression as constant, then we assume the whole expression +** is constant. See sqlite3ExprIsConstant() for additional information. +*/ +static int exprNodeIsConstant(void *pArg, Expr *pExpr){ + int *pN = (int*)pArg; + + /* If *pArg is 3 then any term of the expression that comes from + ** the ON or USING clauses of a join disqualifies the expression + ** from being considered constant. */ + if( (*pN)==3 && ExprHasAnyProperty(pExpr, EP_FromJoin) ){ + *pN = 0; + return 2; + } + + switch( pExpr->op ){ + /* Consider functions to be constant if all their arguments are constant + ** and *pArg==2 */ + case TK_FUNCTION: + if( (*pN)==2 ) return 0; + /* Fall through */ + case TK_ID: + case TK_COLUMN: + case TK_DOT: + case TK_AGG_FUNCTION: + case TK_AGG_COLUMN: +#ifndef SQLITE_OMIT_SUBQUERY + case TK_SELECT: + case TK_EXISTS: + testcase( pExpr->op==TK_SELECT ); + testcase( pExpr->op==TK_EXISTS ); +#endif + testcase( pExpr->op==TK_ID ); + testcase( pExpr->op==TK_COLUMN ); + testcase( pExpr->op==TK_DOT ); + testcase( pExpr->op==TK_AGG_FUNCTION ); + testcase( pExpr->op==TK_AGG_COLUMN ); + *pN = 0; + return 2; + case TK_IN: + if( pExpr->pSelect ){ + *pN = 0; + return 2; + } + default: + return 0; + } +} + +/* +** Walk an expression tree. Return 1 if the expression is constant +** and 0 if it involves variables or function calls. +** +** For the purposes of this function, a double-quoted string (ex: "abc") +** is considered a variable but a single-quoted string (ex: 'abc') is +** a constant. +*/ +int sqlite3ExprIsConstant(Expr *p){ + int isConst = 1; + walkExprTree(p, exprNodeIsConstant, &isConst); + return isConst; +} + +/* +** Walk an expression tree. Return 1 if the expression is constant +** that does no originate from the ON or USING clauses of a join. +** Return 0 if it involves variables or function calls or terms from +** an ON or USING clause. +*/ +int sqlite3ExprIsConstantNotJoin(Expr *p){ + int isConst = 3; + walkExprTree(p, exprNodeIsConstant, &isConst); + return isConst!=0; +} + +/* +** Walk an expression tree. Return 1 if the expression is constant +** or a function call with constant arguments. Return and 0 if there +** are any variables. +** +** For the purposes of this function, a double-quoted string (ex: "abc") +** is considered a variable but a single-quoted string (ex: 'abc') is +** a constant. +*/ +int sqlite3ExprIsConstantOrFunction(Expr *p){ + int isConst = 2; + walkExprTree(p, exprNodeIsConstant, &isConst); + return isConst!=0; +} + +/* +** If the expression p codes a constant integer that is small enough +** to fit in a 32-bit integer, return 1 and put the value of the integer +** in *pValue. If the expression is not an integer or if it is too big +** to fit in a signed 32-bit integer, return 0 and leave *pValue unchanged. +*/ +int sqlite3ExprIsInteger(Expr *p, int *pValue){ + int rc = 0; + if( p->flags & EP_IntValue ){ + *pValue = p->iTable; + return 1; + } + switch( p->op ){ + case TK_INTEGER: { + rc = sqlite3GetInt32((char*)p->token.z, pValue); + break; + } + case TK_UPLUS: { + rc = sqlite3ExprIsInteger(p->pLeft, pValue); + break; + } + case TK_UMINUS: { + int v; + if( sqlite3ExprIsInteger(p->pLeft, &v) ){ + *pValue = -v; + rc = 1; + } + break; + } + default: break; + } + if( rc ){ + p->op = TK_INTEGER; + p->flags |= EP_IntValue; + p->iTable = *pValue; + } + return rc; +} + +/* +** Return TRUE if the given string is a row-id column name. +*/ +int sqlite3IsRowid(const char *z){ + if( sqlite3StrICmp(z, "_ROWID_")==0 ) return 1; + if( sqlite3StrICmp(z, "ROWID")==0 ) return 1; + if( sqlite3StrICmp(z, "OID")==0 ) return 1; + return 0; +} + +/* +** Given the name of a column of the form X.Y.Z or Y.Z or just Z, look up +** that name in the set of source tables in pSrcList and make the pExpr +** expression node refer back to that source column. The following changes +** are made to pExpr: +** +** pExpr->iDb Set the index in db->aDb[] of the database holding +** the table. +** pExpr->iTable Set to the cursor number for the table obtained +** from pSrcList. +** pExpr->iColumn Set to the column number within the table. +** pExpr->op Set to TK_COLUMN. +** pExpr->pLeft Any expression this points to is deleted +** pExpr->pRight Any expression this points to is deleted. +** +** The pDbToken is the name of the database (the "X"). This value may be +** NULL meaning that name is of the form Y.Z or Z. Any available database +** can be used. The pTableToken is the name of the table (the "Y"). This +** value can be NULL if pDbToken is also NULL. If pTableToken is NULL it +** means that the form of the name is Z and that columns from any table +** can be used. +** +** If the name cannot be resolved unambiguously, leave an error message +** in pParse and return non-zero. Return zero on success. +*/ +static int lookupName( + Parse *pParse, /* The parsing context */ + Token *pDbToken, /* Name of the database containing table, or NULL */ + Token *pTableToken, /* Name of table containing column, or NULL */ + Token *pColumnToken, /* Name of the column. */ + NameContext *pNC, /* The name context used to resolve the name */ + Expr *pExpr /* Make this EXPR node point to the selected column */ +){ + char *zDb = 0; /* Name of the database. The "X" in X.Y.Z */ + char *zTab = 0; /* Name of the table. The "Y" in X.Y.Z or Y.Z */ + char *zCol = 0; /* Name of the column. The "Z" */ + int i, j; /* Loop counters */ + int cnt = 0; /* Number of matching column names */ + int cntTab = 0; /* Number of matching table names */ + sqlite3 *db = pParse->db; /* The database */ + struct SrcList_item *pItem; /* Use for looping over pSrcList items */ + struct SrcList_item *pMatch = 0; /* The matching pSrcList item */ + NameContext *pTopNC = pNC; /* First namecontext in the list */ + Schema *pSchema = 0; /* Schema of the expression */ + + assert( pColumnToken && pColumnToken->z ); /* The Z in X.Y.Z cannot be NULL */ + zDb = sqlite3NameFromToken(db, pDbToken); + zTab = sqlite3NameFromToken(db, pTableToken); + zCol = sqlite3NameFromToken(db, pColumnToken); + if( db->mallocFailed ){ + goto lookupname_end; + } + + pExpr->iTable = -1; + while( pNC && cnt==0 ){ + ExprList *pEList; + SrcList *pSrcList = pNC->pSrcList; + + if( pSrcList ){ + for(i=0, pItem=pSrcList->a; i<pSrcList->nSrc; i++, pItem++){ + Table *pTab; + int iDb; + Column *pCol; + + pTab = pItem->pTab; + assert( pTab!=0 ); + iDb = sqlite3SchemaToIndex(db, pTab->pSchema); + assert( pTab->nCol>0 ); + if( zTab ){ + if( pItem->zAlias ){ + char *zTabName = pItem->zAlias; + if( sqlite3StrICmp(zTabName, zTab)!=0 ) continue; + }else{ + char *zTabName = pTab->zName; + if( zTabName==0 || sqlite3StrICmp(zTabName, zTab)!=0 ) continue; + if( zDb!=0 && sqlite3StrICmp(db->aDb[iDb].zName, zDb)!=0 ){ + continue; + } + } + } + if( 0==(cntTab++) ){ + pExpr->iTable = pItem->iCursor; + pSchema = pTab->pSchema; + pMatch = pItem; + } + for(j=0, pCol=pTab->aCol; j<pTab->nCol; j++, pCol++){ + if( sqlite3StrICmp(pCol->zName, zCol)==0 ){ + const char *zColl = pTab->aCol[j].zColl; + IdList *pUsing; + cnt++; + pExpr->iTable = pItem->iCursor; + pMatch = pItem; + pSchema = pTab->pSchema; + /* Substitute the rowid (column -1) for the INTEGER PRIMARY KEY */ + pExpr->iColumn = j==pTab->iPKey ? -1 : j; + pExpr->affinity = pTab->aCol[j].affinity; + if( (pExpr->flags & EP_ExpCollate)==0 ){ + pExpr->pColl = sqlite3FindCollSeq(db, ENC(db), zColl,-1, 0); + } + if( i<pSrcList->nSrc-1 ){ + if( pItem[1].jointype & JT_NATURAL ){ + /* If this match occurred in the left table of a natural join, + ** then skip the right table to avoid a duplicate match */ + pItem++; + i++; + }else if( (pUsing = pItem[1].pUsing)!=0 ){ + /* If this match occurs on a column that is in the USING clause + ** of a join, skip the search of the right table of the join + ** to avoid a duplicate match there. */ + int k; + for(k=0; k<pUsing->nId; k++){ + if( sqlite3StrICmp(pUsing->a[k].zName, zCol)==0 ){ + pItem++; + i++; + break; + } + } + } + } + break; + } + } + } + } + +#ifndef SQLITE_OMIT_TRIGGER + /* If we have not already resolved the name, then maybe + ** it is a new.* or old.* trigger argument reference + */ + if( zDb==0 && zTab!=0 && cnt==0 && pParse->trigStack!=0 ){ + TriggerStack *pTriggerStack = pParse->trigStack; + Table *pTab = 0; + u32 *piColMask; + if( pTriggerStack->newIdx != -1 && sqlite3StrICmp("new", zTab) == 0 ){ + pExpr->iTable = pTriggerStack->newIdx; + assert( pTriggerStack->pTab ); + pTab = pTriggerStack->pTab; + piColMask = &(pTriggerStack->newColMask); + }else if( pTriggerStack->oldIdx != -1 && sqlite3StrICmp("old", zTab)==0 ){ + pExpr->iTable = pTriggerStack->oldIdx; + assert( pTriggerStack->pTab ); + pTab = pTriggerStack->pTab; + piColMask = &(pTriggerStack->oldColMask); + } + + if( pTab ){ + int iCol; + Column *pCol = pTab->aCol; + + pSchema = pTab->pSchema; + cntTab++; + for(iCol=0; iCol < pTab->nCol; iCol++, pCol++) { + if( sqlite3StrICmp(pCol->zName, zCol)==0 ){ + const char *zColl = pTab->aCol[iCol].zColl; + cnt++; + pExpr->iColumn = iCol==pTab->iPKey ? -1 : iCol; + pExpr->affinity = pTab->aCol[iCol].affinity; + if( (pExpr->flags & EP_ExpCollate)==0 ){ + pExpr->pColl = sqlite3FindCollSeq(db, ENC(db), zColl,-1, 0); + } + pExpr->pTab = pTab; + if( iCol>=0 ){ + testcase( iCol==31 ); + testcase( iCol==32 ); + *piColMask |= ((u32)1<<iCol) | (iCol>=32?0xffffffff:0); + } + break; + } + } + } + } +#endif /* !defined(SQLITE_OMIT_TRIGGER) */ + + /* + ** Perhaps the name is a reference to the ROWID + */ + if( cnt==0 && cntTab==1 && sqlite3IsRowid(zCol) ){ + cnt = 1; + pExpr->iColumn = -1; + pExpr->affinity = SQLITE_AFF_INTEGER; + } + + /* + ** If the input is of the form Z (not Y.Z or X.Y.Z) then the name Z + ** might refer to an result-set alias. This happens, for example, when + ** we are resolving names in the WHERE clause of the following command: + ** + ** SELECT a+b AS x FROM table WHERE x<10; + ** + ** In cases like this, replace pExpr with a copy of the expression that + ** forms the result set entry ("a+b" in the example) and return immediately. + ** Note that the expression in the result set should have already been + ** resolved by the time the WHERE clause is resolved. + */ + if( cnt==0 && (pEList = pNC->pEList)!=0 && zTab==0 ){ + for(j=0; j<pEList->nExpr; j++){ + char *zAs = pEList->a[j].zName; + if( zAs!=0 && sqlite3StrICmp(zAs, zCol)==0 ){ + Expr *pDup, *pOrig; + assert( pExpr->pLeft==0 && pExpr->pRight==0 ); + assert( pExpr->pList==0 ); + assert( pExpr->pSelect==0 ); + pOrig = pEList->a[j].pExpr; + if( !pNC->allowAgg && ExprHasProperty(pOrig, EP_Agg) ){ + sqlite3ErrorMsg(pParse, "misuse of aliased aggregate %s", zAs); + sqlite3DbFree(db, zCol); + return 2; + } + pDup = sqlite3ExprDup(db, pOrig); + if( pExpr->flags & EP_ExpCollate ){ + pDup->pColl = pExpr->pColl; + pDup->flags |= EP_ExpCollate; + } + if( pExpr->span.dyn ) sqlite3DbFree(db, (char*)pExpr->span.z); + if( pExpr->token.dyn ) sqlite3DbFree(db, (char*)pExpr->token.z); + memcpy(pExpr, pDup, sizeof(*pExpr)); + sqlite3DbFree(db, pDup); + cnt = 1; + pMatch = 0; + assert( zTab==0 && zDb==0 ); + goto lookupname_end_2; + } + } + } + + /* Advance to the next name context. The loop will exit when either + ** we have a match (cnt>0) or when we run out of name contexts. + */ + if( cnt==0 ){ + pNC = pNC->pNext; + } + } + + /* + ** If X and Y are NULL (in other words if only the column name Z is + ** supplied) and the value of Z is enclosed in double-quotes, then + ** Z is a string literal if it doesn't match any column names. In that + ** case, we need to return right away and not make any changes to + ** pExpr. + ** + ** Because no reference was made to outer contexts, the pNC->nRef + ** fields are not changed in any context. + */ + if( cnt==0 && zTab==0 && pColumnToken->z[0]=='"' ){ + sqlite3DbFree(db, zCol); + return 0; + } + + /* + ** cnt==0 means there was not match. cnt>1 means there were two or + ** more matches. Either way, we have an error. + */ + if( cnt!=1 ){ + const char *zErr; + zErr = cnt==0 ? "no such column" : "ambiguous column name"; + if( zDb ){ + sqlite3ErrorMsg(pParse, "%s: %s.%s.%s", zErr, zDb, zTab, zCol); + }else if( zTab ){ + sqlite3ErrorMsg(pParse, "%s: %s.%s", zErr, zTab, zCol); + }else{ + sqlite3ErrorMsg(pParse, "%s: %s", zErr, zCol); + } + pTopNC->nErr++; + } + + /* If a column from a table in pSrcList is referenced, then record + ** this fact in the pSrcList.a[].colUsed bitmask. Column 0 causes + ** bit 0 to be set. Column 1 sets bit 1. And so forth. If the + ** column number is greater than the number of bits in the bitmask + ** then set the high-order bit of the bitmask. + */ + if( pExpr->iColumn>=0 && pMatch!=0 ){ + int n = pExpr->iColumn; + testcase( n==sizeof(Bitmask)*8-1 ); + if( n>=sizeof(Bitmask)*8 ){ + n = sizeof(Bitmask)*8-1; + } + assert( pMatch->iCursor==pExpr->iTable ); + pMatch->colUsed |= ((Bitmask)1)<<n; + } + +lookupname_end: + /* Clean up and return + */ + sqlite3DbFree(db, zDb); + sqlite3DbFree(db, zTab); + sqlite3ExprDelete(db, pExpr->pLeft); + pExpr->pLeft = 0; + sqlite3ExprDelete(db, pExpr->pRight); + pExpr->pRight = 0; + pExpr->op = TK_COLUMN; +lookupname_end_2: + sqlite3DbFree(db, zCol); + if( cnt==1 ){ + assert( pNC!=0 ); + sqlite3AuthRead(pParse, pExpr, pSchema, pNC->pSrcList); + if( pMatch && !pMatch->pSelect ){ + pExpr->pTab = pMatch->pTab; + } + /* Increment the nRef value on all name contexts from TopNC up to + ** the point where the name matched. */ + for(;;){ + assert( pTopNC!=0 ); + pTopNC->nRef++; + if( pTopNC==pNC ) break; + pTopNC = pTopNC->pNext; + } + return 0; + } else { + return 1; + } +} + +/* +** This routine is designed as an xFunc for walkExprTree(). +** +** Resolve symbolic names into TK_COLUMN operators for the current +** node in the expression tree. Return 0 to continue the search down +** the tree or 2 to abort the tree walk. +** +** This routine also does error checking and name resolution for +** function names. The operator for aggregate functions is changed +** to TK_AGG_FUNCTION. +*/ +static int nameResolverStep(void *pArg, Expr *pExpr){ + NameContext *pNC = (NameContext*)pArg; + Parse *pParse; + + if( pExpr==0 ) return 1; + assert( pNC!=0 ); + pParse = pNC->pParse; + + if( ExprHasAnyProperty(pExpr, EP_Resolved) ) return 1; + ExprSetProperty(pExpr, EP_Resolved); +#ifndef NDEBUG + if( pNC->pSrcList && pNC->pSrcList->nAlloc>0 ){ + SrcList *pSrcList = pNC->pSrcList; + int i; + for(i=0; i<pNC->pSrcList->nSrc; i++){ + assert( pSrcList->a[i].iCursor>=0 && pSrcList->a[i].iCursor<pParse->nTab); + } + } +#endif + switch( pExpr->op ){ + /* Double-quoted strings (ex: "abc") are used as identifiers if + ** possible. Otherwise they remain as strings. Single-quoted + ** strings (ex: 'abc') are always string literals. + */ + case TK_STRING: { + if( pExpr->token.z[0]=='\'' ) break; + /* Fall thru into the TK_ID case if this is a double-quoted string */ + } + /* A lone identifier is the name of a column. + */ + case TK_ID: { + lookupName(pParse, 0, 0, &pExpr->token, pNC, pExpr); + return 1; + } + + /* A table name and column name: ID.ID + ** Or a database, table and column: ID.ID.ID + */ + case TK_DOT: { + Token *pColumn; + Token *pTable; + Token *pDb; + Expr *pRight; + + /* if( pSrcList==0 ) break; */ + pRight = pExpr->pRight; + if( pRight->op==TK_ID ){ + pDb = 0; + pTable = &pExpr->pLeft->token; + pColumn = &pRight->token; + }else{ + assert( pRight->op==TK_DOT ); + pDb = &pExpr->pLeft->token; + pTable = &pRight->pLeft->token; + pColumn = &pRight->pRight->token; + } + lookupName(pParse, pDb, pTable, pColumn, pNC, pExpr); + return 1; + } + + /* Resolve function names + */ + case TK_CONST_FUNC: + case TK_FUNCTION: { + ExprList *pList = pExpr->pList; /* The argument list */ + int n = pList ? pList->nExpr : 0; /* Number of arguments */ + int no_such_func = 0; /* True if no such function exists */ + int wrong_num_args = 0; /* True if wrong number of arguments */ + int is_agg = 0; /* True if is an aggregate function */ + int i; + int auth; /* Authorization to use the function */ + int nId; /* Number of characters in function name */ + const char *zId; /* The function name. */ + FuncDef *pDef; /* Information about the function */ + int enc = ENC(pParse->db); /* The database encoding */ + + zId = (char*)pExpr->token.z; + nId = pExpr->token.n; + pDef = sqlite3FindFunction(pParse->db, zId, nId, n, enc, 0); + if( pDef==0 ){ + pDef = sqlite3FindFunction(pParse->db, zId, nId, -1, enc, 0); + if( pDef==0 ){ + no_such_func = 1; + }else{ + wrong_num_args = 1; + } + }else{ + is_agg = pDef->xFunc==0; + } +#ifndef SQLITE_OMIT_AUTHORIZATION + if( pDef ){ + auth = sqlite3AuthCheck(pParse, SQLITE_FUNCTION, 0, pDef->zName, 0); + if( auth!=SQLITE_OK ){ + if( auth==SQLITE_DENY ){ + sqlite3ErrorMsg(pParse, "not authorized to use function: %s", + pDef->zName); + pNC->nErr++; + } + pExpr->op = TK_NULL; + return 1; + } + } +#endif + if( is_agg && !pNC->allowAgg ){ + sqlite3ErrorMsg(pParse, "misuse of aggregate function %.*s()", nId,zId); + pNC->nErr++; + is_agg = 0; + }else if( no_such_func ){ + sqlite3ErrorMsg(pParse, "no such function: %.*s", nId, zId); + pNC->nErr++; + }else if( wrong_num_args ){ + sqlite3ErrorMsg(pParse,"wrong number of arguments to function %.*s()", + nId, zId); + pNC->nErr++; + } + if( is_agg ){ + pExpr->op = TK_AGG_FUNCTION; + pNC->hasAgg = 1; + } + if( is_agg ) pNC->allowAgg = 0; + for(i=0; pNC->nErr==0 && i<n; i++){ + walkExprTree(pList->a[i].pExpr, nameResolverStep, pNC); + } + if( is_agg ) pNC->allowAgg = 1; + /* FIX ME: Compute pExpr->affinity based on the expected return + ** type of the function + */ + return is_agg; + } +#ifndef SQLITE_OMIT_SUBQUERY + case TK_SELECT: + case TK_EXISTS: +#endif + case TK_IN: { + if( pExpr->pSelect ){ + int nRef = pNC->nRef; +#ifndef SQLITE_OMIT_CHECK + if( pNC->isCheck ){ + sqlite3ErrorMsg(pParse,"subqueries prohibited in CHECK constraints"); + } +#endif + sqlite3SelectResolve(pParse, pExpr->pSelect, pNC); + assert( pNC->nRef>=nRef ); + if( nRef!=pNC->nRef ){ + ExprSetProperty(pExpr, EP_VarSelect); + } + } + break; + } +#ifndef SQLITE_OMIT_CHECK + case TK_VARIABLE: { + if( pNC->isCheck ){ + sqlite3ErrorMsg(pParse,"parameters prohibited in CHECK constraints"); + } + break; + } +#endif + } + return 0; +} + +/* +** This routine walks an expression tree and resolves references to +** table columns. Nodes of the form ID.ID or ID resolve into an +** index to the table in the table list and a column offset. The +** Expr.opcode for such nodes is changed to TK_COLUMN. The Expr.iTable +** value is changed to the index of the referenced table in pTabList +** plus the "base" value. The base value will ultimately become the +** VDBE cursor number for a cursor that is pointing into the referenced +** table. The Expr.iColumn value is changed to the index of the column +** of the referenced table. The Expr.iColumn value for the special +** ROWID column is -1. Any INTEGER PRIMARY KEY column is tried as an +** alias for ROWID. +** +** Also resolve function names and check the functions for proper +** usage. Make sure all function names are recognized and all functions +** have the correct number of arguments. Leave an error message +** in pParse->zErrMsg if anything is amiss. Return the number of errors. +** +** If the expression contains aggregate functions then set the EP_Agg +** property on the expression. +*/ +int sqlite3ExprResolveNames( + NameContext *pNC, /* Namespace to resolve expressions in. */ + Expr *pExpr /* The expression to be analyzed. */ +){ + int savedHasAgg; + + if( pExpr==0 ) return 0; +#if SQLITE_MAX_EXPR_DEPTH>0 + { + if( checkExprHeight(pNC->pParse, pExpr->nHeight + pNC->pParse->nHeight) ){ + return 1; + } + pNC->pParse->nHeight += pExpr->nHeight; + } +#endif + savedHasAgg = pNC->hasAgg; + pNC->hasAgg = 0; + walkExprTree(pExpr, nameResolverStep, pNC); +#if SQLITE_MAX_EXPR_DEPTH>0 + pNC->pParse->nHeight -= pExpr->nHeight; +#endif + if( pNC->nErr>0 ){ + ExprSetProperty(pExpr, EP_Error); + } + if( pNC->hasAgg ){ + ExprSetProperty(pExpr, EP_Agg); + }else if( savedHasAgg ){ + pNC->hasAgg = 1; + } + return ExprHasProperty(pExpr, EP_Error); +} + +/* +** A pointer instance of this structure is used to pass information +** through walkExprTree into codeSubqueryStep(). +*/ +typedef struct QueryCoder QueryCoder; +struct QueryCoder { + Parse *pParse; /* The parsing context */ + NameContext *pNC; /* Namespace of first enclosing query */ +}; + +#ifdef SQLITE_TEST + int sqlite3_enable_in_opt = 1; +#else + #define sqlite3_enable_in_opt 1 +#endif + +/* +** Return true if the IN operator optimization is enabled and +** the SELECT statement p exists and is of the +** simple form: +** +** SELECT <column> FROM <table> +** +** If this is the case, it may be possible to use an existing table +** or index instead of generating an epheremal table. +*/ +#ifndef SQLITE_OMIT_SUBQUERY +static int isCandidateForInOpt(Select *p){ + SrcList *pSrc; + ExprList *pEList; + Table *pTab; + if( !sqlite3_enable_in_opt ) return 0; /* IN optimization must be enabled */ + if( p==0 ) return 0; /* right-hand side of IN is SELECT */ + if( p->pPrior ) return 0; /* Not a compound SELECT */ + if( p->isDistinct ) return 0; /* No DISTINCT keyword */ + if( p->isAgg ) return 0; /* Contains no aggregate functions */ + if( p->pGroupBy ) return 0; /* Has no GROUP BY clause */ + if( p->pLimit ) return 0; /* Has no LIMIT clause */ + if( p->pOffset ) return 0; + if( p->pWhere ) return 0; /* Has no WHERE clause */ + pSrc = p->pSrc; + if( pSrc==0 ) return 0; /* A single table in the FROM clause */ + if( pSrc->nSrc!=1 ) return 0; + if( pSrc->a[0].pSelect ) return 0; /* FROM clause is not a subquery */ + pTab = pSrc->a[0].pTab; + if( pTab==0 ) return 0; + if( pTab->pSelect ) return 0; /* FROM clause is not a view */ + if( IsVirtual(pTab) ) return 0; /* FROM clause not a virtual table */ + pEList = p->pEList; + if( pEList->nExpr!=1 ) return 0; /* One column in the result set */ + if( pEList->a[0].pExpr->op!=TK_COLUMN ) return 0; /* Result is a column */ + return 1; +} +#endif /* SQLITE_OMIT_SUBQUERY */ + +/* +** This function is used by the implementation of the IN (...) operator. +** It's job is to find or create a b-tree structure that may be used +** either to test for membership of the (...) set or to iterate through +** its members, skipping duplicates. +** +** The cursor opened on the structure (database table, database index +** or ephermal table) is stored in pX->iTable before this function returns. +** The returned value indicates the structure type, as follows: +** +** IN_INDEX_ROWID - The cursor was opened on a database table. +** IN_INDEX_INDEX - The cursor was opened on a database index. +** IN_INDEX_EPH - The cursor was opened on a specially created and +** populated epheremal table. +** +** An existing structure may only be used if the SELECT is of the simple +** form: +** +** SELECT <column> FROM <table> +** +** If prNotFound parameter is 0, then the structure will be used to iterate +** through the set members, skipping any duplicates. In this case an +** epheremal table must be used unless the selected <column> is guaranteed +** to be unique - either because it is an INTEGER PRIMARY KEY or it +** is unique by virtue of a constraint or implicit index. +** +** If the prNotFound parameter is not 0, then the structure will be used +** for fast set membership tests. In this case an epheremal table must +** be used unless <column> is an INTEGER PRIMARY KEY or an index can +** be found with <column> as its left-most column. +** +** When the structure is being used for set membership tests, the user +** needs to know whether or not the structure contains an SQL NULL +** value in order to correctly evaluate expressions like "X IN (Y, Z)". +** If there is a chance that the structure may contain a NULL value at +** runtime, then a register is allocated and the register number written +** to *prNotFound. If there is no chance that the structure contains a +** NULL value, then *prNotFound is left unchanged. +** +** If a register is allocated and its location stored in *prNotFound, then +** its initial value is NULL. If the structure does not remain constant +** for the duration of the query (i.e. the set is a correlated sub-select), +** the value of the allocated register is reset to NULL each time the +** structure is repopulated. This allows the caller to use vdbe code +** equivalent to the following: +** +** if( register==NULL ){ +** has_null = <test if data structure contains null> +** register = 1 +** } +** +** in order to avoid running the <test if data structure contains null> +** test more often than is necessary. +*/ +#ifndef SQLITE_OMIT_SUBQUERY +int sqlite3FindInIndex(Parse *pParse, Expr *pX, int *prNotFound){ + Select *p; + int eType = 0; + int iTab = pParse->nTab++; + int mustBeUnique = !prNotFound; + + /* The follwing if(...) expression is true if the SELECT is of the + ** simple form: + ** + ** SELECT <column> FROM <table> + ** + ** If this is the case, it may be possible to use an existing table + ** or index instead of generating an epheremal table. + */ + p = pX->pSelect; + if( isCandidateForInOpt(p) ){ + sqlite3 *db = pParse->db; + Index *pIdx; + Expr *pExpr = p->pEList->a[0].pExpr; + int iCol = pExpr->iColumn; + Vdbe *v = sqlite3GetVdbe(pParse); + + /* This function is only called from two places. In both cases the vdbe + ** has already been allocated. So assume sqlite3GetVdbe() is always + ** successful here. + */ + assert(v); + if( iCol<0 ){ + int iMem = ++pParse->nMem; + int iAddr; + Table *pTab = p->pSrc->a[0].pTab; + int iDb = sqlite3SchemaToIndex(db, pTab->pSchema); + sqlite3VdbeUsesBtree(v, iDb); + + iAddr = sqlite3VdbeAddOp1(v, OP_If, iMem); + sqlite3VdbeAddOp2(v, OP_Integer, 1, iMem); + + sqlite3OpenTable(pParse, iTab, iDb, pTab, OP_OpenRead); + eType = IN_INDEX_ROWID; + + sqlite3VdbeJumpHere(v, iAddr); + }else{ + /* The collation sequence used by the comparison. If an index is to + ** be used in place of a temp-table, it must be ordered according + ** to this collation sequence. + */ + CollSeq *pReq = sqlite3BinaryCompareCollSeq(pParse, pX->pLeft, pExpr); + + /* Check that the affinity that will be used to perform the + ** comparison is the same as the affinity of the column. If + ** it is not, it is not possible to use any index. + */ + Table *pTab = p->pSrc->a[0].pTab; + char aff = comparisonAffinity(pX); + int affinity_ok = (pTab->aCol[iCol].affinity==aff||aff==SQLITE_AFF_NONE); + + for(pIdx=pTab->pIndex; pIdx && eType==0 && affinity_ok; pIdx=pIdx->pNext){ + if( (pIdx->aiColumn[0]==iCol) + && (pReq==sqlite3FindCollSeq(db, ENC(db), pIdx->azColl[0], -1, 0)) + && (!mustBeUnique || (pIdx->nColumn==1 && pIdx->onError!=OE_None)) + ){ + int iDb; + int iMem = ++pParse->nMem; + int iAddr; + char *pKey; + + pKey = (char *)sqlite3IndexKeyinfo(pParse, pIdx); + iDb = sqlite3SchemaToIndex(db, pIdx->pSchema); + sqlite3VdbeUsesBtree(v, iDb); + + iAddr = sqlite3VdbeAddOp1(v, OP_If, iMem); + sqlite3VdbeAddOp2(v, OP_Integer, 1, iMem); + + sqlite3VdbeAddOp2(v, OP_SetNumColumns, 0, pIdx->nColumn); + sqlite3VdbeAddOp4(v, OP_OpenRead, iTab, pIdx->tnum, iDb, + pKey,P4_KEYINFO_HANDOFF); + VdbeComment((v, "%s", pIdx->zName)); + eType = IN_INDEX_INDEX; + + sqlite3VdbeJumpHere(v, iAddr); + if( prNotFound && !pTab->aCol[iCol].notNull ){ + *prNotFound = ++pParse->nMem; + } + } + } + } + } + + if( eType==0 ){ + int rMayHaveNull = 0; + if( prNotFound ){ + *prNotFound = rMayHaveNull = ++pParse->nMem; + } + sqlite3CodeSubselect(pParse, pX, rMayHaveNull); + eType = IN_INDEX_EPH; + }else{ + pX->iTable = iTab; + } + return eType; +} +#endif + +/* +** Generate code for scalar subqueries used as an expression +** and IN operators. Examples: +** +** (SELECT a FROM b) -- subquery +** EXISTS (SELECT a FROM b) -- EXISTS subquery +** x IN (4,5,11) -- IN operator with list on right-hand side +** x IN (SELECT a FROM b) -- IN operator with subquery on the right +** +** The pExpr parameter describes the expression that contains the IN +** operator or subquery. +*/ +#ifndef SQLITE_OMIT_SUBQUERY +void sqlite3CodeSubselect(Parse *pParse, Expr *pExpr, int rMayHaveNull){ + int testAddr = 0; /* One-time test address */ + Vdbe *v = sqlite3GetVdbe(pParse); + if( v==0 ) return; + + + /* This code must be run in its entirety every time it is encountered + ** if any of the following is true: + ** + ** * The right-hand side is a correlated subquery + ** * The right-hand side is an expression list containing variables + ** * We are inside a trigger + ** + ** If all of the above are false, then we can run this code just once + ** save the results, and reuse the same result on subsequent invocations. + */ + if( !ExprHasAnyProperty(pExpr, EP_VarSelect) && !pParse->trigStack ){ + int mem = ++pParse->nMem; + sqlite3VdbeAddOp1(v, OP_If, mem); + testAddr = sqlite3VdbeAddOp2(v, OP_Integer, 1, mem); + assert( testAddr>0 || pParse->db->mallocFailed ); + } + + switch( pExpr->op ){ + case TK_IN: { + char affinity; + KeyInfo keyInfo; + int addr; /* Address of OP_OpenEphemeral instruction */ + + if( rMayHaveNull ){ + sqlite3VdbeAddOp2(v, OP_Null, 0, rMayHaveNull); + } + + affinity = sqlite3ExprAffinity(pExpr->pLeft); + + /* Whether this is an 'x IN(SELECT...)' or an 'x IN(<exprlist>)' + ** expression it is handled the same way. A virtual table is + ** filled with single-field index keys representing the results + ** from the SELECT or the <exprlist>. + ** + ** If the 'x' expression is a column value, or the SELECT... + ** statement returns a column value, then the affinity of that + ** column is used to build the index keys. If both 'x' and the + ** SELECT... statement are columns, then numeric affinity is used + ** if either column has NUMERIC or INTEGER affinity. If neither + ** 'x' nor the SELECT... statement are columns, then numeric affinity + ** is used. + */ + pExpr->iTable = pParse->nTab++; + addr = sqlite3VdbeAddOp2(v, OP_OpenEphemeral, pExpr->iTable, 1); + memset(&keyInfo, 0, sizeof(keyInfo)); + keyInfo.nField = 1; + + if( pExpr->pSelect ){ + /* Case 1: expr IN (SELECT ...) + ** + ** Generate code to write the results of the select into the temporary + ** table allocated and opened above. + */ + SelectDest dest; + ExprList *pEList; + + sqlite3SelectDestInit(&dest, SRT_Set, pExpr->iTable); + dest.affinity = (int)affinity; + assert( (pExpr->iTable&0x0000FFFF)==pExpr->iTable ); + if( sqlite3Select(pParse, pExpr->pSelect, &dest, 0, 0, 0) ){ + return; + } + pEList = pExpr->pSelect->pEList; + if( pEList && pEList->nExpr>0 ){ + keyInfo.aColl[0] = sqlite3BinaryCompareCollSeq(pParse, pExpr->pLeft, + pEList->a[0].pExpr); + } + }else if( pExpr->pList ){ + /* Case 2: expr IN (exprlist) + ** + ** For each expression, build an index key from the evaluation and + ** store it in the temporary table. If <expr> is a column, then use + ** that columns affinity when building index keys. If <expr> is not + ** a column, use numeric affinity. + */ + int i; + ExprList *pList = pExpr->pList; + struct ExprList_item *pItem; + int r1, r2, r3; + + if( !affinity ){ + affinity = SQLITE_AFF_NONE; + } + keyInfo.aColl[0] = pExpr->pLeft->pColl; + + /* Loop through each expression in <exprlist>. */ + r1 = sqlite3GetTempReg(pParse); + r2 = sqlite3GetTempReg(pParse); + for(i=pList->nExpr, pItem=pList->a; i>0; i--, pItem++){ + Expr *pE2 = pItem->pExpr; + + /* If the expression is not constant then we will need to + ** disable the test that was generated above that makes sure + ** this code only executes once. Because for a non-constant + ** expression we need to rerun this code each time. + */ + if( testAddr && !sqlite3ExprIsConstant(pE2) ){ + sqlite3VdbeChangeToNoop(v, testAddr-1, 2); + testAddr = 0; + } + + /* Evaluate the expression and insert it into the temp table */ + pParse->disableColCache++; + r3 = sqlite3ExprCodeTarget(pParse, pE2, r1); + assert( pParse->disableColCache>0 ); + pParse->disableColCache--; + sqlite3VdbeAddOp4(v, OP_MakeRecord, r3, 1, r2, &affinity, 1); + sqlite3ExprCacheAffinityChange(pParse, r3, 1); + sqlite3VdbeAddOp2(v, OP_IdxInsert, pExpr->iTable, r2); + } + sqlite3ReleaseTempReg(pParse, r1); + sqlite3ReleaseTempReg(pParse, r2); + } + sqlite3VdbeChangeP4(v, addr, (void *)&keyInfo, P4_KEYINFO); + break; + } + + case TK_EXISTS: + case TK_SELECT: { + /* This has to be a scalar SELECT. Generate code to put the + ** value of this select in a memory cell and record the number + ** of the memory cell in iColumn. + */ + static const Token one = { (u8*)"1", 0, 1 }; + Select *pSel; + SelectDest dest; + + pSel = pExpr->pSelect; + sqlite3SelectDestInit(&dest, 0, ++pParse->nMem); + if( pExpr->op==TK_SELECT ){ + dest.eDest = SRT_Mem; + sqlite3VdbeAddOp2(v, OP_Null, 0, dest.iParm); + VdbeComment((v, "Init subquery result")); + }else{ + dest.eDest = SRT_Exists; + sqlite3VdbeAddOp2(v, OP_Integer, 0, dest.iParm); + VdbeComment((v, "Init EXISTS result")); + } + sqlite3ExprDelete(pParse->db, pSel->pLimit); + pSel->pLimit = sqlite3PExpr(pParse, TK_INTEGER, 0, 0, &one); + if( sqlite3Select(pParse, pSel, &dest, 0, 0, 0) ){ + return; + } + pExpr->iColumn = dest.iParm; + break; + } + } + + if( testAddr ){ + sqlite3VdbeJumpHere(v, testAddr-1); + } + + return; +} +#endif /* SQLITE_OMIT_SUBQUERY */ + +/* +** Duplicate an 8-byte value +*/ +static char *dup8bytes(Vdbe *v, const char *in){ + char *out = sqlite3DbMallocRaw(sqlite3VdbeDb(v), 8); + if( out ){ + memcpy(out, in, 8); + } + return out; +} + +/* +** Generate an instruction that will put the floating point +** value described by z[0..n-1] into register iMem. +** +** The z[] string will probably not be zero-terminated. But the +** z[n] character is guaranteed to be something that does not look +** like the continuation of the number. +*/ +static void codeReal(Vdbe *v, const char *z, int n, int negateFlag, int iMem){ + assert( z || v==0 || sqlite3VdbeDb(v)->mallocFailed ); + if( z ){ + double value; + char *zV; + assert( !isdigit(z[n]) ); + sqlite3AtoF(z, &value); + if( sqlite3IsNaN(value) ){ + sqlite3VdbeAddOp2(v, OP_Null, 0, iMem); + }else{ + if( negateFlag ) value = -value; + zV = dup8bytes(v, (char*)&value); + sqlite3VdbeAddOp4(v, OP_Real, 0, iMem, 0, zV, P4_REAL); + } + } +} + + +/* +** Generate an instruction that will put the integer describe by +** text z[0..n-1] into register iMem. +** +** The z[] string will probably not be zero-terminated. But the +** z[n] character is guaranteed to be something that does not look +** like the continuation of the number. +*/ +static void codeInteger(Vdbe *v, Expr *pExpr, int negFlag, int iMem){ + const char *z; + if( pExpr->flags & EP_IntValue ){ + int i = pExpr->iTable; + if( negFlag ) i = -i; + sqlite3VdbeAddOp2(v, OP_Integer, i, iMem); + }else if( (z = (char*)pExpr->token.z)!=0 ){ + int i; + int n = pExpr->token.n; + assert( !isdigit(z[n]) ); + if( sqlite3GetInt32(z, &i) ){ + if( negFlag ) i = -i; + sqlite3VdbeAddOp2(v, OP_Integer, i, iMem); + }else if( sqlite3FitsIn64Bits(z, negFlag) ){ + i64 value; + char *zV; + sqlite3Atoi64(z, &value); + if( negFlag ) value = -value; + zV = dup8bytes(v, (char*)&value); + sqlite3VdbeAddOp4(v, OP_Int64, 0, iMem, 0, zV, P4_INT64); + }else{ + codeReal(v, z, n, negFlag, iMem); + } + } +} + + +/* +** Generate code that will extract the iColumn-th column from +** table pTab and store the column value in a register. An effort +** is made to store the column value in register iReg, but this is +** not guaranteed. The location of the column value is returned. +** +** There must be an open cursor to pTab in iTable when this routine +** is called. If iColumn<0 then code is generated that extracts the rowid. +** +** This routine might attempt to reuse the value of the column that +** has already been loaded into a register. The value will always +** be used if it has not undergone any affinity changes. But if +** an affinity change has occurred, then the cached value will only be +** used if allowAffChng is true. +*/ +int sqlite3ExprCodeGetColumn( + Parse *pParse, /* Parsing and code generating context */ + Table *pTab, /* Description of the table we are reading from */ + int iColumn, /* Index of the table column */ + int iTable, /* The cursor pointing to the table */ + int iReg, /* Store results here */ + int allowAffChng /* True if prior affinity changes are OK */ +){ + Vdbe *v = pParse->pVdbe; + int i; + struct yColCache *p; + + for(i=0, p=pParse->aColCache; i<pParse->nColCache; i++, p++){ + if( p->iTable==iTable && p->iColumn==iColumn + && (!p->affChange || allowAffChng) ){ +#if 0 + sqlite3VdbeAddOp0(v, OP_Noop); + VdbeComment((v, "OPT: tab%d.col%d -> r%d", iTable, iColumn, p->iReg)); +#endif + return p->iReg; + } + } + assert( v!=0 ); + if( iColumn<0 ){ + int op = (pTab && IsVirtual(pTab)) ? OP_VRowid : OP_Rowid; + sqlite3VdbeAddOp2(v, op, iTable, iReg); + }else if( pTab==0 ){ + sqlite3VdbeAddOp3(v, OP_Column, iTable, iColumn, iReg); + }else{ + int op = IsVirtual(pTab) ? OP_VColumn : OP_Column; + sqlite3VdbeAddOp3(v, op, iTable, iColumn, iReg); + sqlite3ColumnDefault(v, pTab, iColumn); +#ifndef SQLITE_OMIT_FLOATING_POINT + if( pTab->aCol[iColumn].affinity==SQLITE_AFF_REAL ){ + sqlite3VdbeAddOp1(v, OP_RealAffinity, iReg); + } +#endif + } + if( pParse->disableColCache==0 ){ + i = pParse->iColCache; + p = &pParse->aColCache[i]; + p->iTable = iTable; + p->iColumn = iColumn; + p->iReg = iReg; + p->affChange = 0; + i++; + if( i>=ArraySize(pParse->aColCache) ) i = 0; + if( i>pParse->nColCache ) pParse->nColCache = i; + pParse->iColCache = i; + } + return iReg; +} + +/* +** Clear all column cache entries associated with the vdbe +** cursor with cursor number iTable. +*/ +void sqlite3ExprClearColumnCache(Parse *pParse, int iTable){ + if( iTable<0 ){ + pParse->nColCache = 0; + pParse->iColCache = 0; + }else{ + int i; + for(i=0; i<pParse->nColCache; i++){ + if( pParse->aColCache[i].iTable==iTable ){ + testcase( i==pParse->nColCache-1 ); + pParse->aColCache[i] = pParse->aColCache[--pParse->nColCache]; + pParse->iColCache = pParse->nColCache; + } + } + } +} + +/* +** Record the fact that an affinity change has occurred on iCount +** registers starting with iStart. +*/ +void sqlite3ExprCacheAffinityChange(Parse *pParse, int iStart, int iCount){ + int iEnd = iStart + iCount - 1; + int i; + for(i=0; i<pParse->nColCache; i++){ + int r = pParse->aColCache[i].iReg; + if( r>=iStart && r<=iEnd ){ + pParse->aColCache[i].affChange = 1; + } + } +} + +/* +** Generate code to move content from registers iFrom...iFrom+nReg-1 +** over to iTo..iTo+nReg-1. Keep the column cache up-to-date. +*/ +void sqlite3ExprCodeMove(Parse *pParse, int iFrom, int iTo, int nReg){ + int i; + if( iFrom==iTo ) return; + sqlite3VdbeAddOp3(pParse->pVdbe, OP_Move, iFrom, iTo, nReg); + for(i=0; i<pParse->nColCache; i++){ + int x = pParse->aColCache[i].iReg; + if( x>=iFrom && x<iFrom+nReg ){ + pParse->aColCache[i].iReg += iTo-iFrom; + } + } +} + +/* +** Generate code to copy content from registers iFrom...iFrom+nReg-1 +** over to iTo..iTo+nReg-1. +*/ +void sqlite3ExprCodeCopy(Parse *pParse, int iFrom, int iTo, int nReg){ + int i; + if( iFrom==iTo ) return; + for(i=0; i<nReg; i++){ + sqlite3VdbeAddOp2(pParse->pVdbe, OP_Copy, iFrom+i, iTo+i); + } +} + +/* +** Return true if any register in the range iFrom..iTo (inclusive) +** is used as part of the column cache. +*/ +static int usedAsColumnCache(Parse *pParse, int iFrom, int iTo){ + int i; + for(i=0; i<pParse->nColCache; i++){ + int r = pParse->aColCache[i].iReg; + if( r>=iFrom && r<=iTo ) return 1; + } + return 0; +} + +/* +** Theres is a value in register iCurrent. We ultimately want +** the value to be in register iTarget. It might be that +** iCurrent and iTarget are the same register. +** +** We are going to modify the value, so we need to make sure it +** is not a cached register. If iCurrent is a cached register, +** then try to move the value over to iTarget. If iTarget is a +** cached register, then clear the corresponding cache line. +** +** Return the register that the value ends up in. +*/ +int sqlite3ExprWritableRegister(Parse *pParse, int iCurrent, int iTarget){ + int i; + assert( pParse->pVdbe!=0 ); + if( !usedAsColumnCache(pParse, iCurrent, iCurrent) ){ + return iCurrent; + } + if( iCurrent!=iTarget ){ + sqlite3VdbeAddOp2(pParse->pVdbe, OP_SCopy, iCurrent, iTarget); + } + for(i=0; i<pParse->nColCache; i++){ + if( pParse->aColCache[i].iReg==iTarget ){ + pParse->aColCache[i] = pParse->aColCache[--pParse->nColCache]; + pParse->iColCache = pParse->nColCache; + } + } + return iTarget; +} + +/* +** If the last instruction coded is an ephemeral copy of any of +** the registers in the nReg registers beginning with iReg, then +** convert the last instruction from OP_SCopy to OP_Copy. +*/ +void sqlite3ExprHardCopy(Parse *pParse, int iReg, int nReg){ + int addr; + VdbeOp *pOp; + Vdbe *v; + + v = pParse->pVdbe; + addr = sqlite3VdbeCurrentAddr(v); + pOp = sqlite3VdbeGetOp(v, addr-1); + assert( pOp || pParse->db->mallocFailed ); + if( pOp && pOp->opcode==OP_SCopy && pOp->p1>=iReg && pOp->p1<iReg+nReg ){ + pOp->opcode = OP_Copy; + } +} + +/* +** Generate code into the current Vdbe to evaluate the given +** expression. Attempt to store the results in register "target". +** Return the register where results are stored. +** +** With this routine, there is no guaranteed that results will +** be stored in target. The result might be stored in some other +** register if it is convenient to do so. The calling function +** must check the return code and move the results to the desired +** register. +*/ +int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target){ + Vdbe *v = pParse->pVdbe; /* The VM under construction */ + int op; /* The opcode being coded */ + int inReg = target; /* Results stored in register inReg */ + int regFree1 = 0; /* If non-zero free this temporary register */ + int regFree2 = 0; /* If non-zero free this temporary register */ + int r1, r2, r3, r4; /* Various register numbers */ + + assert( v!=0 || pParse->db->mallocFailed ); + assert( target>0 && target<=pParse->nMem ); + if( v==0 ) return 0; + + if( pExpr==0 ){ + op = TK_NULL; + }else{ + op = pExpr->op; + } + switch( op ){ + case TK_AGG_COLUMN: { + AggInfo *pAggInfo = pExpr->pAggInfo; + struct AggInfo_col *pCol = &pAggInfo->aCol[pExpr->iAgg]; + if( !pAggInfo->directMode ){ + assert( pCol->iMem>0 ); + inReg = pCol->iMem; + break; + }else if( pAggInfo->useSortingIdx ){ + sqlite3VdbeAddOp3(v, OP_Column, pAggInfo->sortingIdx, + pCol->iSorterColumn, target); + break; + } + /* Otherwise, fall thru into the TK_COLUMN case */ + } + case TK_COLUMN: { + if( pExpr->iTable<0 ){ + /* This only happens when coding check constraints */ + assert( pParse->ckBase>0 ); + inReg = pExpr->iColumn + pParse->ckBase; + }else{ + testcase( (pExpr->flags & EP_AnyAff)!=0 ); + inReg = sqlite3ExprCodeGetColumn(pParse, pExpr->pTab, + pExpr->iColumn, pExpr->iTable, target, + pExpr->flags & EP_AnyAff); + } + break; + } + case TK_INTEGER: { + codeInteger(v, pExpr, 0, target); + break; + } + case TK_FLOAT: { + codeReal(v, (char*)pExpr->token.z, pExpr->token.n, 0, target); + break; + } + case TK_STRING: { + sqlite3DequoteExpr(pParse->db, pExpr); + sqlite3VdbeAddOp4(v,OP_String8, 0, target, 0, + (char*)pExpr->token.z, pExpr->token.n); + break; + } + case TK_NULL: { + sqlite3VdbeAddOp2(v, OP_Null, 0, target); + break; + } +#ifndef SQLITE_OMIT_BLOB_LITERAL + case TK_BLOB: { + int n; + const char *z; + char *zBlob; + assert( pExpr->token.n>=3 ); + assert( pExpr->token.z[0]=='x' || pExpr->token.z[0]=='X' ); + assert( pExpr->token.z[1]=='\'' ); + assert( pExpr->token.z[pExpr->token.n-1]=='\'' ); + n = pExpr->token.n - 3; + z = (char*)pExpr->token.z + 2; + zBlob = sqlite3HexToBlob(sqlite3VdbeDb(v), z, n); + sqlite3VdbeAddOp4(v, OP_Blob, n/2, target, 0, zBlob, P4_DYNAMIC); + break; + } +#endif + case TK_VARIABLE: { + sqlite3VdbeAddOp2(v, OP_Variable, pExpr->iTable, target); + if( pExpr->token.n>1 ){ + sqlite3VdbeChangeP4(v, -1, (char*)pExpr->token.z, pExpr->token.n); + } + break; + } + case TK_REGISTER: { + inReg = pExpr->iTable; + break; + } +#ifndef SQLITE_OMIT_CAST + case TK_CAST: { + /* Expressions of the form: CAST(pLeft AS token) */ + int aff, to_op; + inReg = sqlite3ExprCodeTarget(pParse, pExpr->pLeft, target); + aff = sqlite3AffinityType(&pExpr->token); + to_op = aff - SQLITE_AFF_TEXT + OP_ToText; + assert( to_op==OP_ToText || aff!=SQLITE_AFF_TEXT ); + assert( to_op==OP_ToBlob || aff!=SQLITE_AFF_NONE ); + assert( to_op==OP_ToNumeric || aff!=SQLITE_AFF_NUMERIC ); + assert( to_op==OP_ToInt || aff!=SQLITE_AFF_INTEGER ); + assert( to_op==OP_ToReal || aff!=SQLITE_AFF_REAL ); + testcase( to_op==OP_ToText ); + testcase( to_op==OP_ToBlob ); + testcase( to_op==OP_ToNumeric ); + testcase( to_op==OP_ToInt ); + testcase( to_op==OP_ToReal ); + sqlite3VdbeAddOp1(v, to_op, inReg); + testcase( usedAsColumnCache(pParse, inReg, inReg) ); + sqlite3ExprCacheAffinityChange(pParse, inReg, 1); + break; + } +#endif /* SQLITE_OMIT_CAST */ + case TK_LT: + case TK_LE: + case TK_GT: + case TK_GE: + case TK_NE: + case TK_EQ: { + assert( TK_LT==OP_Lt ); + assert( TK_LE==OP_Le ); + assert( TK_GT==OP_Gt ); + assert( TK_GE==OP_Ge ); + assert( TK_EQ==OP_Eq ); + assert( TK_NE==OP_Ne ); + testcase( op==TK_LT ); + testcase( op==TK_LE ); + testcase( op==TK_GT ); + testcase( op==TK_GE ); + testcase( op==TK_EQ ); + testcase( op==TK_NE ); + codeCompareOperands(pParse, pExpr->pLeft, &r1, ®Free1, + pExpr->pRight, &r2, ®Free2); + codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op, + r1, r2, inReg, SQLITE_STOREP2); + testcase( regFree1==0 ); + testcase( regFree2==0 ); + break; + } + case TK_AND: + case TK_OR: + case TK_PLUS: + case TK_STAR: + case TK_MINUS: + case TK_REM: + case TK_BITAND: + case TK_BITOR: + case TK_SLASH: + case TK_LSHIFT: + case TK_RSHIFT: + case TK_CONCAT: { + assert( TK_AND==OP_And ); + assert( TK_OR==OP_Or ); + assert( TK_PLUS==OP_Add ); + assert( TK_MINUS==OP_Subtract ); + assert( TK_REM==OP_Remainder ); + assert( TK_BITAND==OP_BitAnd ); + assert( TK_BITOR==OP_BitOr ); + assert( TK_SLASH==OP_Divide ); + assert( TK_LSHIFT==OP_ShiftLeft ); + assert( TK_RSHIFT==OP_ShiftRight ); + assert( TK_CONCAT==OP_Concat ); + testcase( op==TK_AND ); + testcase( op==TK_OR ); + testcase( op==TK_PLUS ); + testcase( op==TK_MINUS ); + testcase( op==TK_REM ); + testcase( op==TK_BITAND ); + testcase( op==TK_BITOR ); + testcase( op==TK_SLASH ); + testcase( op==TK_LSHIFT ); + testcase( op==TK_RSHIFT ); + testcase( op==TK_CONCAT ); + r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free1); + r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, ®Free2); + sqlite3VdbeAddOp3(v, op, r2, r1, target); + testcase( regFree1==0 ); + testcase( regFree2==0 ); + break; + } + case TK_UMINUS: { + Expr *pLeft = pExpr->pLeft; + assert( pLeft ); + if( pLeft->op==TK_FLOAT || pLeft->op==TK_INTEGER ){ + if( pLeft->op==TK_FLOAT ){ + codeReal(v, (char*)pLeft->token.z, pLeft->token.n, 1, target); + }else{ + codeInteger(v, pLeft, 1, target); + } + }else{ + regFree1 = r1 = sqlite3GetTempReg(pParse); + sqlite3VdbeAddOp2(v, OP_Integer, 0, r1); + r2 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free2); + sqlite3VdbeAddOp3(v, OP_Subtract, r2, r1, target); + testcase( regFree2==0 ); + } + inReg = target; + break; + } + case TK_BITNOT: + case TK_NOT: { + assert( TK_BITNOT==OP_BitNot ); + assert( TK_NOT==OP_Not ); + testcase( op==TK_BITNOT ); + testcase( op==TK_NOT ); + inReg = sqlite3ExprCodeTarget(pParse, pExpr->pLeft, target); + testcase( inReg==target ); + testcase( usedAsColumnCache(pParse, inReg, inReg) ); + inReg = sqlite3ExprWritableRegister(pParse, inReg, target); + sqlite3VdbeAddOp1(v, op, inReg); + break; + } + case TK_ISNULL: + case TK_NOTNULL: { + int addr; + assert( TK_ISNULL==OP_IsNull ); + assert( TK_NOTNULL==OP_NotNull ); + testcase( op==TK_ISNULL ); + testcase( op==TK_NOTNULL ); + sqlite3VdbeAddOp2(v, OP_Integer, 1, target); + r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free1); + testcase( regFree1==0 ); + addr = sqlite3VdbeAddOp1(v, op, r1); + sqlite3VdbeAddOp2(v, OP_AddImm, target, -1); + sqlite3VdbeJumpHere(v, addr); + break; + } + case TK_AGG_FUNCTION: { + AggInfo *pInfo = pExpr->pAggInfo; + if( pInfo==0 ){ + sqlite3ErrorMsg(pParse, "misuse of aggregate: %T", + &pExpr->span); + }else{ + inReg = pInfo->aFunc[pExpr->iAgg].iMem; + } + break; + } + case TK_CONST_FUNC: + case TK_FUNCTION: { + ExprList *pList = pExpr->pList; + int nExpr = pList ? pList->nExpr : 0; + FuncDef *pDef; + int nId; + const char *zId; + int constMask = 0; + int i; + sqlite3 *db = pParse->db; + u8 enc = ENC(db); + CollSeq *pColl = 0; + + testcase( op==TK_CONST_FUNC ); + testcase( op==TK_FUNCTION ); + zId = (char*)pExpr->token.z; + nId = pExpr->token.n; + pDef = sqlite3FindFunction(pParse->db, zId, nId, nExpr, enc, 0); + assert( pDef!=0 ); + if( pList ){ + nExpr = pList->nExpr; + r1 = sqlite3GetTempRange(pParse, nExpr); + sqlite3ExprCodeExprList(pParse, pList, r1, 1); + }else{ + nExpr = r1 = 0; + } +#ifndef SQLITE_OMIT_VIRTUALTABLE + /* Possibly overload the function if the first argument is + ** a virtual table column. + ** + ** For infix functions (LIKE, GLOB, REGEXP, and MATCH) use the + ** second argument, not the first, as the argument to test to + ** see if it is a column in a virtual table. This is done because + ** the left operand of infix functions (the operand we want to + ** control overloading) ends up as the second argument to the + ** function. The expression "A glob B" is equivalent to + ** "glob(B,A). We want to use the A in "A glob B" to test + ** for function overloading. But we use the B term in "glob(B,A)". + */ + if( nExpr>=2 && (pExpr->flags & EP_InfixFunc) ){ + pDef = sqlite3VtabOverloadFunction(db, pDef, nExpr, pList->a[1].pExpr); + }else if( nExpr>0 ){ + pDef = sqlite3VtabOverloadFunction(db, pDef, nExpr, pList->a[0].pExpr); + } +#endif + for(i=0; i<nExpr && i<32; i++){ + if( sqlite3ExprIsConstant(pList->a[i].pExpr) ){ + constMask |= (1<<i); + } + if( pDef->needCollSeq && !pColl ){ + pColl = sqlite3ExprCollSeq(pParse, pList->a[i].pExpr); + } + } + if( pDef->needCollSeq ){ + if( !pColl ) pColl = pParse->db->pDfltColl; + sqlite3VdbeAddOp4(v, OP_CollSeq, 0, 0, 0, (char *)pColl, P4_COLLSEQ); + } + sqlite3VdbeAddOp4(v, OP_Function, constMask, r1, target, + (char*)pDef, P4_FUNCDEF); + sqlite3VdbeChangeP5(v, nExpr); + if( nExpr ){ + sqlite3ReleaseTempRange(pParse, r1, nExpr); + } + sqlite3ExprCacheAffinityChange(pParse, r1, nExpr); + break; + } +#ifndef SQLITE_OMIT_SUBQUERY + case TK_EXISTS: + case TK_SELECT: { + testcase( op==TK_EXISTS ); + testcase( op==TK_SELECT ); + if( pExpr->iColumn==0 ){ + sqlite3CodeSubselect(pParse, pExpr, 0); + } + inReg = pExpr->iColumn; + break; + } + case TK_IN: { + int rNotFound = 0; + int rMayHaveNull = 0; + int j2, j3, j4, j5; + char affinity; + int eType; + + VdbeNoopComment((v, "begin IN expr r%d", target)); + eType = sqlite3FindInIndex(pParse, pExpr, &rMayHaveNull); + if( rMayHaveNull ){ + rNotFound = ++pParse->nMem; + } + + /* Figure out the affinity to use to create a key from the results + ** of the expression. affinityStr stores a static string suitable for + ** P4 of OP_MakeRecord. + */ + affinity = comparisonAffinity(pExpr); + + + /* Code the <expr> from "<expr> IN (...)". The temporary table + ** pExpr->iTable contains the values that make up the (...) set. + */ + pParse->disableColCache++; + sqlite3ExprCode(pParse, pExpr->pLeft, target); + pParse->disableColCache--; + j2 = sqlite3VdbeAddOp1(v, OP_IsNull, target); + if( eType==IN_INDEX_ROWID ){ + j3 = sqlite3VdbeAddOp1(v, OP_MustBeInt, target); + j4 = sqlite3VdbeAddOp3(v, OP_NotExists, pExpr->iTable, 0, target); + sqlite3VdbeAddOp2(v, OP_Integer, 1, target); + j5 = sqlite3VdbeAddOp0(v, OP_Goto); + sqlite3VdbeJumpHere(v, j3); + sqlite3VdbeJumpHere(v, j4); + sqlite3VdbeAddOp2(v, OP_Integer, 0, target); + }else{ + r2 = regFree2 = sqlite3GetTempReg(pParse); + + /* Create a record and test for set membership. If the set contains + ** the value, then jump to the end of the test code. The target + ** register still contains the true (1) value written to it earlier. + */ + sqlite3VdbeAddOp4(v, OP_MakeRecord, target, 1, r2, &affinity, 1); + sqlite3VdbeAddOp2(v, OP_Integer, 1, target); + j5 = sqlite3VdbeAddOp3(v, OP_Found, pExpr->iTable, 0, r2); + + /* If the set membership test fails, then the result of the + ** "x IN (...)" expression must be either 0 or NULL. If the set + ** contains no NULL values, then the result is 0. If the set + ** contains one or more NULL values, then the result of the + ** expression is also NULL. + */ + if( rNotFound==0 ){ + /* This branch runs if it is known at compile time (now) that + ** the set contains no NULL values. This happens as the result + ** of a "NOT NULL" constraint in the database schema. No need + ** to test the data structure at runtime in this case. + */ + sqlite3VdbeAddOp2(v, OP_Integer, 0, target); + }else{ + /* This block populates the rNotFound register with either NULL + ** or 0 (an integer value). If the data structure contains one + ** or more NULLs, then set rNotFound to NULL. Otherwise, set it + ** to 0. If register rMayHaveNull is already set to some value + ** other than NULL, then the test has already been run and + ** rNotFound is already populated. + */ + static const char nullRecord[] = { 0x02, 0x00 }; + j3 = sqlite3VdbeAddOp1(v, OP_NotNull, rMayHaveNull); + sqlite3VdbeAddOp2(v, OP_Null, 0, rNotFound); + sqlite3VdbeAddOp4(v, OP_Blob, 2, rMayHaveNull, 0, + nullRecord, P4_STATIC); + j4 = sqlite3VdbeAddOp3(v, OP_Found, pExpr->iTable, 0, rMayHaveNull); + sqlite3VdbeAddOp2(v, OP_Integer, 0, rNotFound); + sqlite3VdbeJumpHere(v, j4); + sqlite3VdbeJumpHere(v, j3); + + /* Copy the value of register rNotFound (which is either NULL or 0) + ** into the target register. This will be the result of the + ** expression. + */ + sqlite3VdbeAddOp2(v, OP_Copy, rNotFound, target); + } + } + sqlite3VdbeJumpHere(v, j2); + sqlite3VdbeJumpHere(v, j5); + VdbeComment((v, "end IN expr r%d", target)); + break; + } +#endif + /* + ** x BETWEEN y AND z + ** + ** This is equivalent to + ** + ** x>=y AND x<=z + ** + ** X is stored in pExpr->pLeft. + ** Y is stored in pExpr->pList->a[0].pExpr. + ** Z is stored in pExpr->pList->a[1].pExpr. + */ + case TK_BETWEEN: { + Expr *pLeft = pExpr->pLeft; + struct ExprList_item *pLItem = pExpr->pList->a; + Expr *pRight = pLItem->pExpr; + + codeCompareOperands(pParse, pLeft, &r1, ®Free1, + pRight, &r2, ®Free2); + testcase( regFree1==0 ); + testcase( regFree2==0 ); + r3 = sqlite3GetTempReg(pParse); + r4 = sqlite3GetTempReg(pParse); + codeCompare(pParse, pLeft, pRight, OP_Ge, + r1, r2, r3, SQLITE_STOREP2); + pLItem++; + pRight = pLItem->pExpr; + sqlite3ReleaseTempReg(pParse, regFree2); + r2 = sqlite3ExprCodeTemp(pParse, pRight, ®Free2); + testcase( regFree2==0 ); + codeCompare(pParse, pLeft, pRight, OP_Le, r1, r2, r4, SQLITE_STOREP2); + sqlite3VdbeAddOp3(v, OP_And, r3, r4, target); + sqlite3ReleaseTempReg(pParse, r3); + sqlite3ReleaseTempReg(pParse, r4); + break; + } + case TK_UPLUS: { + inReg = sqlite3ExprCodeTarget(pParse, pExpr->pLeft, target); + break; + } + + /* + ** Form A: + ** CASE x WHEN e1 THEN r1 WHEN e2 THEN r2 ... WHEN eN THEN rN ELSE y END + ** + ** Form B: + ** CASE WHEN e1 THEN r1 WHEN e2 THEN r2 ... WHEN eN THEN rN ELSE y END + ** + ** Form A is can be transformed into the equivalent form B as follows: + ** CASE WHEN x=e1 THEN r1 WHEN x=e2 THEN r2 ... + ** WHEN x=eN THEN rN ELSE y END + ** + ** X (if it exists) is in pExpr->pLeft. + ** Y is in pExpr->pRight. The Y is also optional. If there is no + ** ELSE clause and no other term matches, then the result of the + ** exprssion is NULL. + ** Ei is in pExpr->pList->a[i*2] and Ri is pExpr->pList->a[i*2+1]. + ** + ** The result of the expression is the Ri for the first matching Ei, + ** or if there is no matching Ei, the ELSE term Y, or if there is + ** no ELSE term, NULL. + */ + case TK_CASE: { + int endLabel; /* GOTO label for end of CASE stmt */ + int nextCase; /* GOTO label for next WHEN clause */ + int nExpr; /* 2x number of WHEN terms */ + int i; /* Loop counter */ + ExprList *pEList; /* List of WHEN terms */ + struct ExprList_item *aListelem; /* Array of WHEN terms */ + Expr opCompare; /* The X==Ei expression */ + Expr cacheX; /* Cached expression X */ + Expr *pX; /* The X expression */ + Expr *pTest; /* X==Ei (form A) or just Ei (form B) */ + + assert(pExpr->pList); + assert((pExpr->pList->nExpr % 2) == 0); + assert(pExpr->pList->nExpr > 0); + pEList = pExpr->pList; + aListelem = pEList->a; + nExpr = pEList->nExpr; + endLabel = sqlite3VdbeMakeLabel(v); + if( (pX = pExpr->pLeft)!=0 ){ + cacheX = *pX; + testcase( pX->op==TK_COLUMN || pX->op==TK_REGISTER ); + cacheX.iTable = sqlite3ExprCodeTemp(pParse, pX, ®Free1); + testcase( regFree1==0 ); + cacheX.op = TK_REGISTER; + cacheX.iColumn = 0; + opCompare.op = TK_EQ; + opCompare.pLeft = &cacheX; + pTest = &opCompare; + } + pParse->disableColCache++; + for(i=0; i<nExpr; i=i+2){ + if( pX ){ + opCompare.pRight = aListelem[i].pExpr; + }else{ + pTest = aListelem[i].pExpr; + } + nextCase = sqlite3VdbeMakeLabel(v); + testcase( pTest->op==TK_COLUMN || pTest->op==TK_REGISTER ); + sqlite3ExprIfFalse(pParse, pTest, nextCase, SQLITE_JUMPIFNULL); + testcase( aListelem[i+1].pExpr->op==TK_COLUMN ); + testcase( aListelem[i+1].pExpr->op==TK_REGISTER ); + sqlite3ExprCode(pParse, aListelem[i+1].pExpr, target); + sqlite3VdbeAddOp2(v, OP_Goto, 0, endLabel); + sqlite3VdbeResolveLabel(v, nextCase); + } + if( pExpr->pRight ){ + sqlite3ExprCode(pParse, pExpr->pRight, target); + }else{ + sqlite3VdbeAddOp2(v, OP_Null, 0, target); + } + sqlite3VdbeResolveLabel(v, endLabel); + assert( pParse->disableColCache>0 ); + pParse->disableColCache--; + break; + } +#ifndef SQLITE_OMIT_TRIGGER + case TK_RAISE: { + if( !pParse->trigStack ){ + sqlite3ErrorMsg(pParse, + "RAISE() may only be used within a trigger-program"); + return 0; + } + if( pExpr->iColumn!=OE_Ignore ){ + assert( pExpr->iColumn==OE_Rollback || + pExpr->iColumn == OE_Abort || + pExpr->iColumn == OE_Fail ); + sqlite3DequoteExpr(pParse->db, pExpr); + sqlite3VdbeAddOp4(v, OP_Halt, SQLITE_CONSTRAINT, pExpr->iColumn, 0, + (char*)pExpr->token.z, pExpr->token.n); + } else { + assert( pExpr->iColumn == OE_Ignore ); + sqlite3VdbeAddOp2(v, OP_ContextPop, 0, 0); + sqlite3VdbeAddOp2(v, OP_Goto, 0, pParse->trigStack->ignoreJump); + VdbeComment((v, "raise(IGNORE)")); + } + break; + } +#endif + } + sqlite3ReleaseTempReg(pParse, regFree1); + sqlite3ReleaseTempReg(pParse, regFree2); + return inReg; +} + +/* +** Generate code to evaluate an expression and store the results +** into a register. Return the register number where the results +** are stored. +** +** If the register is a temporary register that can be deallocated, +** then write its number into *pReg. If the result register is not +** a temporary, then set *pReg to zero. +*/ +int sqlite3ExprCodeTemp(Parse *pParse, Expr *pExpr, int *pReg){ + int r1 = sqlite3GetTempReg(pParse); + int r2 = sqlite3ExprCodeTarget(pParse, pExpr, r1); + if( r2==r1 ){ + *pReg = r1; + }else{ + sqlite3ReleaseTempReg(pParse, r1); + *pReg = 0; + } + return r2; +} + +/* +** Generate code that will evaluate expression pExpr and store the +** results in register target. The results are guaranteed to appear +** in register target. +*/ +int sqlite3ExprCode(Parse *pParse, Expr *pExpr, int target){ + int inReg; + + assert( target>0 && target<=pParse->nMem ); + inReg = sqlite3ExprCodeTarget(pParse, pExpr, target); + assert( pParse->pVdbe || pParse->db->mallocFailed ); + if( inReg!=target && pParse->pVdbe ){ + sqlite3VdbeAddOp2(pParse->pVdbe, OP_SCopy, inReg, target); + } + return target; +} + +/* +** Generate code that evalutes the given expression and puts the result +** in register target. +** +** Also make a copy of the expression results into another "cache" register +** and modify the expression so that the next time it is evaluated, +** the result is a copy of the cache register. +** +** This routine is used for expressions that are used multiple +** times. They are evaluated once and the results of the expression +** are reused. +*/ +int sqlite3ExprCodeAndCache(Parse *pParse, Expr *pExpr, int target){ + Vdbe *v = pParse->pVdbe; + int inReg; + inReg = sqlite3ExprCode(pParse, pExpr, target); + assert( target>0 ); + if( pExpr->op!=TK_REGISTER ){ + int iMem; + iMem = ++pParse->nMem; + sqlite3VdbeAddOp2(v, OP_Copy, inReg, iMem); + pExpr->iTable = iMem; + pExpr->iColumn = pExpr->op; + pExpr->op = TK_REGISTER; + } + return inReg; +} + +/* +** Return TRUE if pExpr is an constant expression that is appropriate +** for factoring out of a loop. Appropriate expressions are: +** +** * Any expression that evaluates to two or more opcodes. +** +** * Any OP_Integer, OP_Real, OP_String, OP_Blob, OP_Null, +** or OP_Variable that does not need to be placed in a +** specific register. +** +** There is no point in factoring out single-instruction constant +** expressions that need to be placed in a particular register. +** We could factor them out, but then we would end up adding an +** OP_SCopy instruction to move the value into the correct register +** later. We might as well just use the original instruction and +** avoid the OP_SCopy. +*/ +static int isAppropriateForFactoring(Expr *p){ + if( !sqlite3ExprIsConstantNotJoin(p) ){ + return 0; /* Only constant expressions are appropriate for factoring */ + } + if( (p->flags & EP_FixedDest)==0 ){ + return 1; /* Any constant without a fixed destination is appropriate */ + } + while( p->op==TK_UPLUS ) p = p->pLeft; + switch( p->op ){ +#ifndef SQLITE_OMIT_BLOB_LITERAL + case TK_BLOB: +#endif + case TK_VARIABLE: + case TK_INTEGER: + case TK_FLOAT: + case TK_NULL: + case TK_STRING: { + testcase( p->op==TK_BLOB ); + testcase( p->op==TK_VARIABLE ); + testcase( p->op==TK_INTEGER ); + testcase( p->op==TK_FLOAT ); + testcase( p->op==TK_NULL ); + testcase( p->op==TK_STRING ); + /* Single-instruction constants with a fixed destination are + ** better done in-line. If we factor them, they will just end + ** up generating an OP_SCopy to move the value to the destination + ** register. */ + return 0; + } + case TK_UMINUS: { + if( p->pLeft->op==TK_FLOAT || p->pLeft->op==TK_INTEGER ){ + return 0; + } + break; + } + default: { + break; + } + } + return 1; +} + +/* +** If pExpr is a constant expression that is appropriate for +** factoring out of a loop, then evaluate the expression +** into a register and convert the expression into a TK_REGISTER +** expression. +*/ +static int evalConstExpr(void *pArg, Expr *pExpr){ + Parse *pParse = (Parse*)pArg; + switch( pExpr->op ){ + case TK_REGISTER: { + return 1; + } + case TK_FUNCTION: + case TK_AGG_FUNCTION: + case TK_CONST_FUNC: { + /* The arguments to a function have a fixed destination. + ** Mark them this way to avoid generated unneeded OP_SCopy + ** instructions. + */ + ExprList *pList = pExpr->pList; + if( pList ){ + int i = pList->nExpr; + struct ExprList_item *pItem = pList->a; + for(; i>0; i--, pItem++){ + if( pItem->pExpr ) pItem->pExpr->flags |= EP_FixedDest; + } + } + break; + } + } + if( isAppropriateForFactoring(pExpr) ){ + int r1 = ++pParse->nMem; + int r2; + r2 = sqlite3ExprCodeTarget(pParse, pExpr, r1); + if( r1!=r2 ) sqlite3ReleaseTempReg(pParse, r1); + pExpr->iColumn = pExpr->op; + pExpr->op = TK_REGISTER; + pExpr->iTable = r2; + return 1; + } + return 0; +} + +/* +** Preevaluate constant subexpressions within pExpr and store the +** results in registers. Modify pExpr so that the constant subexpresions +** are TK_REGISTER opcodes that refer to the precomputed values. +*/ +void sqlite3ExprCodeConstants(Parse *pParse, Expr *pExpr){ + walkExprTree(pExpr, evalConstExpr, pParse); +} + + +/* +** Generate code that pushes the value of every element of the given +** expression list into a sequence of registers beginning at target. +** +** Return the number of elements evaluated. +*/ +int sqlite3ExprCodeExprList( + Parse *pParse, /* Parsing context */ + ExprList *pList, /* The expression list to be coded */ + int target, /* Where to write results */ + int doHardCopy /* Call sqlite3ExprHardCopy on each element if true */ +){ + struct ExprList_item *pItem; + int i, n; + assert( pList!=0 || pParse->db->mallocFailed ); + if( pList==0 ){ + return 0; + } + assert( target>0 ); + n = pList->nExpr; + for(pItem=pList->a, i=0; i<n; i++, pItem++){ + sqlite3ExprCode(pParse, pItem->pExpr, target+i); + if( doHardCopy ) sqlite3ExprHardCopy(pParse, target, n); + } + return n; +} + +/* +** Generate code for a boolean expression such that a jump is made +** to the label "dest" if the expression is true but execution +** continues straight thru if the expression is false. +** +** If the expression evaluates to NULL (neither true nor false), then +** take the jump if the jumpIfNull flag is SQLITE_JUMPIFNULL. +** +** This code depends on the fact that certain token values (ex: TK_EQ) +** are the same as opcode values (ex: OP_Eq) that implement the corresponding +** operation. Special comments in vdbe.c and the mkopcodeh.awk script in +** the make process cause these values to align. Assert()s in the code +** below verify that the numbers are aligned correctly. +*/ +void sqlite3ExprIfTrue(Parse *pParse, Expr *pExpr, int dest, int jumpIfNull){ + Vdbe *v = pParse->pVdbe; + int op = 0; + int regFree1 = 0; + int regFree2 = 0; + int r1, r2; + + assert( jumpIfNull==SQLITE_JUMPIFNULL || jumpIfNull==0 ); + if( v==0 || pExpr==0 ) return; + op = pExpr->op; + switch( op ){ + case TK_AND: { + int d2 = sqlite3VdbeMakeLabel(v); + testcase( jumpIfNull==0 ); + testcase( pParse->disableColCache==0 ); + sqlite3ExprIfFalse(pParse, pExpr->pLeft, d2,jumpIfNull^SQLITE_JUMPIFNULL); + pParse->disableColCache++; + sqlite3ExprIfTrue(pParse, pExpr->pRight, dest, jumpIfNull); + assert( pParse->disableColCache>0 ); + pParse->disableColCache--; + sqlite3VdbeResolveLabel(v, d2); + break; + } + case TK_OR: { + testcase( jumpIfNull==0 ); + testcase( pParse->disableColCache==0 ); + sqlite3ExprIfTrue(pParse, pExpr->pLeft, dest, jumpIfNull); + pParse->disableColCache++; + sqlite3ExprIfTrue(pParse, pExpr->pRight, dest, jumpIfNull); + assert( pParse->disableColCache>0 ); + pParse->disableColCache--; + break; + } + case TK_NOT: { + testcase( jumpIfNull==0 ); + sqlite3ExprIfFalse(pParse, pExpr->pLeft, dest, jumpIfNull); + break; + } + case TK_LT: + case TK_LE: + case TK_GT: + case TK_GE: + case TK_NE: + case TK_EQ: { + assert( TK_LT==OP_Lt ); + assert( TK_LE==OP_Le ); + assert( TK_GT==OP_Gt ); + assert( TK_GE==OP_Ge ); + assert( TK_EQ==OP_Eq ); + assert( TK_NE==OP_Ne ); + testcase( op==TK_LT ); + testcase( op==TK_LE ); + testcase( op==TK_GT ); + testcase( op==TK_GE ); + testcase( op==TK_EQ ); + testcase( op==TK_NE ); + testcase( jumpIfNull==0 ); + codeCompareOperands(pParse, pExpr->pLeft, &r1, ®Free1, + pExpr->pRight, &r2, ®Free2); + codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op, + r1, r2, dest, jumpIfNull); + testcase( regFree1==0 ); + testcase( regFree2==0 ); + break; + } + case TK_ISNULL: + case TK_NOTNULL: { + assert( TK_ISNULL==OP_IsNull ); + assert( TK_NOTNULL==OP_NotNull ); + testcase( op==TK_ISNULL ); + testcase( op==TK_NOTNULL ); + r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free1); + sqlite3VdbeAddOp2(v, op, r1, dest); + testcase( regFree1==0 ); + break; + } + case TK_BETWEEN: { + /* x BETWEEN y AND z + ** + ** Is equivalent to + ** + ** x>=y AND x<=z + ** + ** Code it as such, taking care to do the common subexpression + ** elementation of x. + */ + Expr exprAnd; + Expr compLeft; + Expr compRight; + Expr exprX; + + exprX = *pExpr->pLeft; + exprAnd.op = TK_AND; + exprAnd.pLeft = &compLeft; + exprAnd.pRight = &compRight; + compLeft.op = TK_GE; + compLeft.pLeft = &exprX; + compLeft.pRight = pExpr->pList->a[0].pExpr; + compRight.op = TK_LE; + compRight.pLeft = &exprX; + compRight.pRight = pExpr->pList->a[1].pExpr; + exprX.iTable = sqlite3ExprCodeTemp(pParse, &exprX, ®Free1); + testcase( regFree1==0 ); + exprX.op = TK_REGISTER; + testcase( jumpIfNull==0 ); + sqlite3ExprIfTrue(pParse, &exprAnd, dest, jumpIfNull); + break; + } + default: { + r1 = sqlite3ExprCodeTemp(pParse, pExpr, ®Free1); + sqlite3VdbeAddOp3(v, OP_If, r1, dest, jumpIfNull!=0); + testcase( regFree1==0 ); + testcase( jumpIfNull==0 ); + break; + } + } + sqlite3ReleaseTempReg(pParse, regFree1); + sqlite3ReleaseTempReg(pParse, regFree2); +} + +/* +** Generate code for a boolean expression such that a jump is made +** to the label "dest" if the expression is false but execution +** continues straight thru if the expression is true. +** +** If the expression evaluates to NULL (neither true nor false) then +** jump if jumpIfNull is SQLITE_JUMPIFNULL or fall through if jumpIfNull +** is 0. +*/ +void sqlite3ExprIfFalse(Parse *pParse, Expr *pExpr, int dest, int jumpIfNull){ + Vdbe *v = pParse->pVdbe; + int op = 0; + int regFree1 = 0; + int regFree2 = 0; + int r1, r2; + + assert( jumpIfNull==SQLITE_JUMPIFNULL || jumpIfNull==0 ); + if( v==0 || pExpr==0 ) return; + + /* The value of pExpr->op and op are related as follows: + ** + ** pExpr->op op + ** --------- ---------- + ** TK_ISNULL OP_NotNull + ** TK_NOTNULL OP_IsNull + ** TK_NE OP_Eq + ** TK_EQ OP_Ne + ** TK_GT OP_Le + ** TK_LE OP_Gt + ** TK_GE OP_Lt + ** TK_LT OP_Ge + ** + ** For other values of pExpr->op, op is undefined and unused. + ** The value of TK_ and OP_ constants are arranged such that we + ** can compute the mapping above using the following expression. + ** Assert()s verify that the computation is correct. + */ + op = ((pExpr->op+(TK_ISNULL&1))^1)-(TK_ISNULL&1); + + /* Verify correct alignment of TK_ and OP_ constants + */ + assert( pExpr->op!=TK_ISNULL || op==OP_NotNull ); + assert( pExpr->op!=TK_NOTNULL || op==OP_IsNull ); + assert( pExpr->op!=TK_NE || op==OP_Eq ); + assert( pExpr->op!=TK_EQ || op==OP_Ne ); + assert( pExpr->op!=TK_LT || op==OP_Ge ); + assert( pExpr->op!=TK_LE || op==OP_Gt ); + assert( pExpr->op!=TK_GT || op==OP_Le ); + assert( pExpr->op!=TK_GE || op==OP_Lt ); + + switch( pExpr->op ){ + case TK_AND: { + testcase( jumpIfNull==0 ); + testcase( pParse->disableColCache==0 ); + sqlite3ExprIfFalse(pParse, pExpr->pLeft, dest, jumpIfNull); + pParse->disableColCache++; + sqlite3ExprIfFalse(pParse, pExpr->pRight, dest, jumpIfNull); + assert( pParse->disableColCache>0 ); + pParse->disableColCache--; + break; + } + case TK_OR: { + int d2 = sqlite3VdbeMakeLabel(v); + testcase( jumpIfNull==0 ); + testcase( pParse->disableColCache==0 ); + sqlite3ExprIfTrue(pParse, pExpr->pLeft, d2, jumpIfNull^SQLITE_JUMPIFNULL); + pParse->disableColCache++; + sqlite3ExprIfFalse(pParse, pExpr->pRight, dest, jumpIfNull); + assert( pParse->disableColCache>0 ); + pParse->disableColCache--; + sqlite3VdbeResolveLabel(v, d2); + break; + } + case TK_NOT: { + sqlite3ExprIfTrue(pParse, pExpr->pLeft, dest, jumpIfNull); + break; + } + case TK_LT: + case TK_LE: + case TK_GT: + case TK_GE: + case TK_NE: + case TK_EQ: { + testcase( op==TK_LT ); + testcase( op==TK_LE ); + testcase( op==TK_GT ); + testcase( op==TK_GE ); + testcase( op==TK_EQ ); + testcase( op==TK_NE ); + testcase( jumpIfNull==0 ); + codeCompareOperands(pParse, pExpr->pLeft, &r1, ®Free1, + pExpr->pRight, &r2, ®Free2); + codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op, + r1, r2, dest, jumpIfNull); + testcase( regFree1==0 ); + testcase( regFree2==0 ); + break; + } + case TK_ISNULL: + case TK_NOTNULL: { + testcase( op==TK_ISNULL ); + testcase( op==TK_NOTNULL ); + r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free1); + sqlite3VdbeAddOp2(v, op, r1, dest); + testcase( regFree1==0 ); + break; + } + case TK_BETWEEN: { + /* x BETWEEN y AND z + ** + ** Is equivalent to + ** + ** x>=y AND x<=z + ** + ** Code it as such, taking care to do the common subexpression + ** elementation of x. + */ + Expr exprAnd; + Expr compLeft; + Expr compRight; + Expr exprX; + + exprX = *pExpr->pLeft; + exprAnd.op = TK_AND; + exprAnd.pLeft = &compLeft; + exprAnd.pRight = &compRight; + compLeft.op = TK_GE; + compLeft.pLeft = &exprX; + compLeft.pRight = pExpr->pList->a[0].pExpr; + compRight.op = TK_LE; + compRight.pLeft = &exprX; + compRight.pRight = pExpr->pList->a[1].pExpr; + exprX.iTable = sqlite3ExprCodeTemp(pParse, &exprX, ®Free1); + testcase( regFree1==0 ); + exprX.op = TK_REGISTER; + testcase( jumpIfNull==0 ); + sqlite3ExprIfFalse(pParse, &exprAnd, dest, jumpIfNull); + break; + } + default: { + r1 = sqlite3ExprCodeTemp(pParse, pExpr, ®Free1); + sqlite3VdbeAddOp3(v, OP_IfNot, r1, dest, jumpIfNull!=0); + testcase( regFree1==0 ); + testcase( jumpIfNull==0 ); + break; + } + } + sqlite3ReleaseTempReg(pParse, regFree1); + sqlite3ReleaseTempReg(pParse, regFree2); +} + +/* +** Do a deep comparison of two expression trees. Return TRUE (non-zero) +** if they are identical and return FALSE if they differ in any way. +** +** Sometimes this routine will return FALSE even if the two expressions +** really are equivalent. If we cannot prove that the expressions are +** identical, we return FALSE just to be safe. So if this routine +** returns false, then you do not really know for certain if the two +** expressions are the same. But if you get a TRUE return, then you +** can be sure the expressions are the same. In the places where +** this routine is used, it does not hurt to get an extra FALSE - that +** just might result in some slightly slower code. But returning +** an incorrect TRUE could lead to a malfunction. +*/ +int sqlite3ExprCompare(Expr *pA, Expr *pB){ + int i; + if( pA==0||pB==0 ){ + return pB==pA; + } + if( pA->op!=pB->op ) return 0; + if( (pA->flags & EP_Distinct)!=(pB->flags & EP_Distinct) ) return 0; + if( !sqlite3ExprCompare(pA->pLeft, pB->pLeft) ) return 0; + if( !sqlite3ExprCompare(pA->pRight, pB->pRight) ) return 0; + if( pA->pList ){ + if( pB->pList==0 ) return 0; + if( pA->pList->nExpr!=pB->pList->nExpr ) return 0; + for(i=0; i<pA->pList->nExpr; i++){ + if( !sqlite3ExprCompare(pA->pList->a[i].pExpr, pB->pList->a[i].pExpr) ){ + return 0; + } + } + }else if( pB->pList ){ + return 0; + } + if( pA->pSelect || pB->pSelect ) return 0; + if( pA->iTable!=pB->iTable || pA->iColumn!=pB->iColumn ) return 0; + if( pA->op!=TK_COLUMN && pA->token.z ){ + if( pB->token.z==0 ) return 0; + if( pB->token.n!=pA->token.n ) return 0; + if( sqlite3StrNICmp((char*)pA->token.z,(char*)pB->token.z,pB->token.n)!=0 ){ + return 0; + } + } + return 1; +} + + +/* +** Add a new element to the pAggInfo->aCol[] array. Return the index of +** the new element. Return a negative number if malloc fails. +*/ +static int addAggInfoColumn(sqlite3 *db, AggInfo *pInfo){ + int i; + pInfo->aCol = sqlite3ArrayAllocate( + db, + pInfo->aCol, + sizeof(pInfo->aCol[0]), + 3, + &pInfo->nColumn, + &pInfo->nColumnAlloc, + &i + ); + return i; +} + +/* +** Add a new element to the pAggInfo->aFunc[] array. Return the index of +** the new element. Return a negative number if malloc fails. +*/ +static int addAggInfoFunc(sqlite3 *db, AggInfo *pInfo){ + int i; + pInfo->aFunc = sqlite3ArrayAllocate( + db, + pInfo->aFunc, + sizeof(pInfo->aFunc[0]), + 3, + &pInfo->nFunc, + &pInfo->nFuncAlloc, + &i + ); + return i; +} + +/* +** This is an xFunc for walkExprTree() used to implement +** sqlite3ExprAnalyzeAggregates(). See sqlite3ExprAnalyzeAggregates +** for additional information. +** +** This routine analyzes the aggregate function at pExpr. +*/ +static int analyzeAggregate(void *pArg, Expr *pExpr){ + int i; + NameContext *pNC = (NameContext *)pArg; + Parse *pParse = pNC->pParse; + SrcList *pSrcList = pNC->pSrcList; + AggInfo *pAggInfo = pNC->pAggInfo; + + switch( pExpr->op ){ + case TK_AGG_COLUMN: + case TK_COLUMN: { + /* Check to see if the column is in one of the tables in the FROM + ** clause of the aggregate query */ + if( pSrcList ){ + struct SrcList_item *pItem = pSrcList->a; + for(i=0; i<pSrcList->nSrc; i++, pItem++){ + struct AggInfo_col *pCol; + if( pExpr->iTable==pItem->iCursor ){ + /* If we reach this point, it means that pExpr refers to a table + ** that is in the FROM clause of the aggregate query. + ** + ** Make an entry for the column in pAggInfo->aCol[] if there + ** is not an entry there already. + */ + int k; + pCol = pAggInfo->aCol; + for(k=0; k<pAggInfo->nColumn; k++, pCol++){ + if( pCol->iTable==pExpr->iTable && + pCol->iColumn==pExpr->iColumn ){ + break; + } + } + if( (k>=pAggInfo->nColumn) + && (k = addAggInfoColumn(pParse->db, pAggInfo))>=0 + ){ + pCol = &pAggInfo->aCol[k]; + pCol->pTab = pExpr->pTab; + pCol->iTable = pExpr->iTable; + pCol->iColumn = pExpr->iColumn; + pCol->iMem = ++pParse->nMem; + pCol->iSorterColumn = -1; + pCol->pExpr = pExpr; + if( pAggInfo->pGroupBy ){ + int j, n; + ExprList *pGB = pAggInfo->pGroupBy; + struct ExprList_item *pTerm = pGB->a; + n = pGB->nExpr; + for(j=0; j<n; j++, pTerm++){ + Expr *pE = pTerm->pExpr; + if( pE->op==TK_COLUMN && pE->iTable==pExpr->iTable && + pE->iColumn==pExpr->iColumn ){ + pCol->iSorterColumn = j; + break; + } + } + } + if( pCol->iSorterColumn<0 ){ + pCol->iSorterColumn = pAggInfo->nSortingColumn++; + } + } + /* There is now an entry for pExpr in pAggInfo->aCol[] (either + ** because it was there before or because we just created it). + ** Convert the pExpr to be a TK_AGG_COLUMN referring to that + ** pAggInfo->aCol[] entry. + */ + pExpr->pAggInfo = pAggInfo; + pExpr->op = TK_AGG_COLUMN; + pExpr->iAgg = k; + break; + } /* endif pExpr->iTable==pItem->iCursor */ + } /* end loop over pSrcList */ + } + return 1; + } + case TK_AGG_FUNCTION: { + /* The pNC->nDepth==0 test causes aggregate functions in subqueries + ** to be ignored */ + if( pNC->nDepth==0 ){ + /* Check to see if pExpr is a duplicate of another aggregate + ** function that is already in the pAggInfo structure + */ + struct AggInfo_func *pItem = pAggInfo->aFunc; + for(i=0; i<pAggInfo->nFunc; i++, pItem++){ + if( sqlite3ExprCompare(pItem->pExpr, pExpr) ){ + break; + } + } + if( i>=pAggInfo->nFunc ){ + /* pExpr is original. Make a new entry in pAggInfo->aFunc[] + */ + u8 enc = ENC(pParse->db); + i = addAggInfoFunc(pParse->db, pAggInfo); + if( i>=0 ){ + pItem = &pAggInfo->aFunc[i]; + pItem->pExpr = pExpr; + pItem->iMem = ++pParse->nMem; + pItem->pFunc = sqlite3FindFunction(pParse->db, + (char*)pExpr->token.z, pExpr->token.n, + pExpr->pList ? pExpr->pList->nExpr : 0, enc, 0); + if( pExpr->flags & EP_Distinct ){ + pItem->iDistinct = pParse->nTab++; + }else{ + pItem->iDistinct = -1; + } + } + } + /* Make pExpr point to the appropriate pAggInfo->aFunc[] entry + */ + pExpr->iAgg = i; + pExpr->pAggInfo = pAggInfo; + return 1; + } + } + } + + /* Recursively walk subqueries looking for TK_COLUMN nodes that need + ** to be changed to TK_AGG_COLUMN. But increment nDepth so that + ** TK_AGG_FUNCTION nodes in subqueries will be unchanged. + */ + if( pExpr->pSelect ){ + pNC->nDepth++; + walkSelectExpr(pExpr->pSelect, analyzeAggregate, pNC); + pNC->nDepth--; + } + return 0; +} + +/* +** Analyze the given expression looking for aggregate functions and +** for variables that need to be added to the pParse->aAgg[] array. +** Make additional entries to the pParse->aAgg[] array as necessary. +** +** This routine should only be called after the expression has been +** analyzed by sqlite3ExprResolveNames(). +*/ +void sqlite3ExprAnalyzeAggregates(NameContext *pNC, Expr *pExpr){ + walkExprTree(pExpr, analyzeAggregate, pNC); +} + +/* +** Call sqlite3ExprAnalyzeAggregates() for every expression in an +** expression list. Return the number of errors. +** +** If an error is found, the analysis is cut short. +*/ +void sqlite3ExprAnalyzeAggList(NameContext *pNC, ExprList *pList){ + struct ExprList_item *pItem; + int i; + if( pList ){ + for(pItem=pList->a, i=0; i<pList->nExpr; i++, pItem++){ + sqlite3ExprAnalyzeAggregates(pNC, pItem->pExpr); + } + } +} + +/* +** Allocate or deallocate temporary use registers during code generation. +*/ +int sqlite3GetTempReg(Parse *pParse){ + if( pParse->nTempReg==0 ){ + return ++pParse->nMem; + } + return pParse->aTempReg[--pParse->nTempReg]; +} +void sqlite3ReleaseTempReg(Parse *pParse, int iReg){ + if( iReg && pParse->nTempReg<ArraySize(pParse->aTempReg) ){ + sqlite3ExprWritableRegister(pParse, iReg, iReg); + pParse->aTempReg[pParse->nTempReg++] = iReg; + } +} + +/* +** Allocate or deallocate a block of nReg consecutive registers +*/ +int sqlite3GetTempRange(Parse *pParse, int nReg){ + int i, n; + i = pParse->iRangeReg; + n = pParse->nRangeReg; + if( nReg<=n && !usedAsColumnCache(pParse, i, i+n-1) ){ + pParse->iRangeReg += nReg; + pParse->nRangeReg -= nReg; + }else{ + i = pParse->nMem+1; + pParse->nMem += nReg; + } + return i; +} +void sqlite3ReleaseTempRange(Parse *pParse, int iReg, int nReg){ + if( nReg>pParse->nRangeReg ){ + pParse->nRangeReg = nReg; + pParse->iRangeReg = iReg; + } +} |