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Unified Diff: third_party/sqlite/sqlite-src-3080704/src/resolve.c

Issue 949043002: Add //third_party/sqlite to dirs_to_snapshot, remove net_sql.patch (Closed) Base URL: git@github.com:domokit/mojo.git@master
Patch Set: Created 5 years, 10 months ago
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Index: third_party/sqlite/sqlite-src-3080704/src/resolve.c
diff --git a/third_party/sqlite/sqlite-src-3080704/src/resolve.c b/third_party/sqlite/sqlite-src-3080704/src/resolve.c
new file mode 100644
index 0000000000000000000000000000000000000000..068e3355680ca050fc9f8fb2ef58a14d42918e1e
--- /dev/null
+++ b/third_party/sqlite/sqlite-src-3080704/src/resolve.c
@@ -0,0 +1,1465 @@
+/*
+** 2008 August 18
+**
+** 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 walking the parser tree and
+** resolve all identifiers by associating them with a particular
+** table and column.
+*/
+#include "sqliteInt.h"
+#include <stdlib.h>
+#include <string.h>
+
+/*
+** Walk the expression tree pExpr and increase the aggregate function
+** depth (the Expr.op2 field) by N on every TK_AGG_FUNCTION node.
+** This needs to occur when copying a TK_AGG_FUNCTION node from an
+** outer query into an inner subquery.
+**
+** incrAggFunctionDepth(pExpr,n) is the main routine. incrAggDepth(..)
+** is a helper function - a callback for the tree walker.
+*/
+static int incrAggDepth(Walker *pWalker, Expr *pExpr){
+ if( pExpr->op==TK_AGG_FUNCTION ) pExpr->op2 += pWalker->u.i;
+ return WRC_Continue;
+}
+static void incrAggFunctionDepth(Expr *pExpr, int N){
+ if( N>0 ){
+ Walker w;
+ memset(&w, 0, sizeof(w));
+ w.xExprCallback = incrAggDepth;
+ w.u.i = N;
+ sqlite3WalkExpr(&w, pExpr);
+ }
+}
+
+/*
+** Turn the pExpr expression into an alias for the iCol-th column of the
+** result set in pEList.
+**
+** If the result set column is a simple column reference, then this routine
+** makes an exact copy. But for any other kind of expression, this
+** routine make a copy of the result set column as the argument to the
+** TK_AS operator. The TK_AS operator causes the expression to be
+** evaluated just once and then reused for each alias.
+**
+** The reason for suppressing the TK_AS term when the expression is a simple
+** column reference is so that the column reference will be recognized as
+** usable by indices within the WHERE clause processing logic.
+**
+** The TK_AS operator is inhibited if zType[0]=='G'. This means
+** that in a GROUP BY clause, the expression is evaluated twice. Hence:
+**
+** SELECT random()%5 AS x, count(*) FROM tab GROUP BY x
+**
+** Is equivalent to:
+**
+** SELECT random()%5 AS x, count(*) FROM tab GROUP BY random()%5
+**
+** The result of random()%5 in the GROUP BY clause is probably different
+** from the result in the result-set. On the other hand Standard SQL does
+** not allow the GROUP BY clause to contain references to result-set columns.
+** So this should never come up in well-formed queries.
+**
+** If the reference is followed by a COLLATE operator, then make sure
+** the COLLATE operator is preserved. For example:
+**
+** SELECT a+b, c+d FROM t1 ORDER BY 1 COLLATE nocase;
+**
+** Should be transformed into:
+**
+** SELECT a+b, c+d FROM t1 ORDER BY (a+b) COLLATE nocase;
+**
+** The nSubquery parameter specifies how many levels of subquery the
+** alias is removed from the original expression. The usually value is
+** zero but it might be more if the alias is contained within a subquery
+** of the original expression. The Expr.op2 field of TK_AGG_FUNCTION
+** structures must be increased by the nSubquery amount.
+*/
+static void resolveAlias(
+ Parse *pParse, /* Parsing context */
+ ExprList *pEList, /* A result set */
+ int iCol, /* A column in the result set. 0..pEList->nExpr-1 */
+ Expr *pExpr, /* Transform this into an alias to the result set */
+ const char *zType, /* "GROUP" or "ORDER" or "" */
+ int nSubquery /* Number of subqueries that the label is moving */
+){
+ Expr *pOrig; /* The iCol-th column of the result set */
+ Expr *pDup; /* Copy of pOrig */
+ sqlite3 *db; /* The database connection */
+
+ assert( iCol>=0 && iCol<pEList->nExpr );
+ pOrig = pEList->a[iCol].pExpr;
+ assert( pOrig!=0 );
+ assert( pOrig->flags & EP_Resolved );
+ db = pParse->db;
+ pDup = sqlite3ExprDup(db, pOrig, 0);
+ if( pDup==0 ) return;
+ if( pOrig->op!=TK_COLUMN && zType[0]!='G' ){
+ incrAggFunctionDepth(pDup, nSubquery);
+ pDup = sqlite3PExpr(pParse, TK_AS, pDup, 0, 0);
+ if( pDup==0 ) return;
+ ExprSetProperty(pDup, EP_Skip);
+ if( pEList->a[iCol].u.x.iAlias==0 ){
+ pEList->a[iCol].u.x.iAlias = (u16)(++pParse->nAlias);
+ }
+ pDup->iTable = pEList->a[iCol].u.x.iAlias;
+ }
+ if( pExpr->op==TK_COLLATE ){
+ pDup = sqlite3ExprAddCollateString(pParse, pDup, pExpr->u.zToken);
+ }
+
+ /* Before calling sqlite3ExprDelete(), set the EP_Static flag. This
+ ** prevents ExprDelete() from deleting the Expr structure itself,
+ ** allowing it to be repopulated by the memcpy() on the following line.
+ ** The pExpr->u.zToken might point into memory that will be freed by the
+ ** sqlite3DbFree(db, pDup) on the last line of this block, so be sure to
+ ** make a copy of the token before doing the sqlite3DbFree().
+ */
+ ExprSetProperty(pExpr, EP_Static);
+ sqlite3ExprDelete(db, pExpr);
+ memcpy(pExpr, pDup, sizeof(*pExpr));
+ if( !ExprHasProperty(pExpr, EP_IntValue) && pExpr->u.zToken!=0 ){
+ assert( (pExpr->flags & (EP_Reduced|EP_TokenOnly))==0 );
+ pExpr->u.zToken = sqlite3DbStrDup(db, pExpr->u.zToken);
+ pExpr->flags |= EP_MemToken;
+ }
+ sqlite3DbFree(db, pDup);
+}
+
+
+/*
+** Return TRUE if the name zCol occurs anywhere in the USING clause.
+**
+** Return FALSE if the USING clause is NULL or if it does not contain
+** zCol.
+*/
+static int nameInUsingClause(IdList *pUsing, const char *zCol){
+ if( pUsing ){
+ int k;
+ for(k=0; k<pUsing->nId; k++){
+ if( sqlite3StrICmp(pUsing->a[k].zName, zCol)==0 ) return 1;
+ }
+ }
+ return 0;
+}
+
+/*
+** Subqueries stores the original database, table and column names for their
+** result sets in ExprList.a[].zSpan, in the form "DATABASE.TABLE.COLUMN".
+** Check to see if the zSpan given to this routine matches the zDb, zTab,
+** and zCol. If any of zDb, zTab, and zCol are NULL then those fields will
+** match anything.
+*/
+int sqlite3MatchSpanName(
+ const char *zSpan,
+ const char *zCol,
+ const char *zTab,
+ const char *zDb
+){
+ int n;
+ for(n=0; ALWAYS(zSpan[n]) && zSpan[n]!='.'; n++){}
+ if( zDb && (sqlite3StrNICmp(zSpan, zDb, n)!=0 || zDb[n]!=0) ){
+ return 0;
+ }
+ zSpan += n+1;
+ for(n=0; ALWAYS(zSpan[n]) && zSpan[n]!='.'; n++){}
+ if( zTab && (sqlite3StrNICmp(zSpan, zTab, n)!=0 || zTab[n]!=0) ){
+ return 0;
+ }
+ zSpan += n+1;
+ if( zCol && sqlite3StrICmp(zSpan, zCol)!=0 ){
+ return 0;
+ }
+ return 1;
+}
+
+/*
+** 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 X
+** (even if X is implied).
+** pExpr->iTable Set to the cursor number for the table obtained
+** from pSrcList.
+** pExpr->pTab Points to the Table structure of X.Y (even if
+** X and/or Y are implied.)
+** 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 zDb variable 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 zTable variable is the name of the table (the "Y"). This
+** value can be NULL if zDb is also NULL. If zTable 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 WRC_Abort. Return WRC_Prune on success.
+*/
+static int lookupName(
+ Parse *pParse, /* The parsing context */
+ const char *zDb, /* Name of the database containing table, or NULL */
+ const char *zTab, /* Name of table containing column, or NULL */
+ const char *zCol, /* 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 */
+){
+ int i, j; /* Loop counters */
+ int cnt = 0; /* Number of matching column names */
+ int cntTab = 0; /* Number of matching table names */
+ int nSubquery = 0; /* How many levels of subquery */
+ sqlite3 *db = pParse->db; /* The database connection */
+ 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 */
+ int isTrigger = 0; /* True if resolved to a trigger column */
+ Table *pTab = 0; /* Table hold the row */
+ Column *pCol; /* A column of pTab */
+
+ assert( pNC ); /* the name context cannot be NULL. */
+ assert( zCol ); /* The Z in X.Y.Z cannot be NULL */
+ assert( !ExprHasProperty(pExpr, EP_TokenOnly|EP_Reduced) );
+
+ /* Initialize the node to no-match */
+ pExpr->iTable = -1;
+ pExpr->pTab = 0;
+ ExprSetVVAProperty(pExpr, EP_NoReduce);
+
+ /* Translate the schema name in zDb into a pointer to the corresponding
+ ** schema. If not found, pSchema will remain NULL and nothing will match
+ ** resulting in an appropriate error message toward the end of this routine
+ */
+ if( zDb ){
+ testcase( pNC->ncFlags & NC_PartIdx );
+ testcase( pNC->ncFlags & NC_IsCheck );
+ if( (pNC->ncFlags & (NC_PartIdx|NC_IsCheck))!=0 ){
+ /* Silently ignore database qualifiers inside CHECK constraints and partial
+ ** indices. Do not raise errors because that might break legacy and
+ ** because it does not hurt anything to just ignore the database name. */
+ zDb = 0;
+ }else{
+ for(i=0; i<db->nDb; i++){
+ assert( db->aDb[i].zName );
+ if( sqlite3StrICmp(db->aDb[i].zName,zDb)==0 ){
+ pSchema = db->aDb[i].pSchema;
+ break;
+ }
+ }
+ }
+ }
+
+ /* Start at the inner-most context and move outward until a match is found */
+ while( pNC && cnt==0 ){
+ ExprList *pEList;
+ SrcList *pSrcList = pNC->pSrcList;
+
+ if( pSrcList ){
+ for(i=0, pItem=pSrcList->a; i<pSrcList->nSrc; i++, pItem++){
+ pTab = pItem->pTab;
+ assert( pTab!=0 && pTab->zName!=0 );
+ assert( pTab->nCol>0 );
+ if( pItem->pSelect && (pItem->pSelect->selFlags & SF_NestedFrom)!=0 ){
+ int hit = 0;
+ pEList = pItem->pSelect->pEList;
+ for(j=0; j<pEList->nExpr; j++){
+ if( sqlite3MatchSpanName(pEList->a[j].zSpan, zCol, zTab, zDb) ){
+ cnt++;
+ cntTab = 2;
+ pMatch = pItem;
+ pExpr->iColumn = j;
+ hit = 1;
+ }
+ }
+ if( hit || zTab==0 ) continue;
+ }
+ if( zDb && pTab->pSchema!=pSchema ){
+ continue;
+ }
+ if( zTab ){
+ const char *zTabName = pItem->zAlias ? pItem->zAlias : pTab->zName;
+ assert( zTabName!=0 );
+ if( sqlite3StrICmp(zTabName, zTab)!=0 ){
+ continue;
+ }
+ }
+ if( 0==(cntTab++) ){
+ pMatch = pItem;
+ }
+ for(j=0, pCol=pTab->aCol; j<pTab->nCol; j++, pCol++){
+ if( sqlite3StrICmp(pCol->zName, zCol)==0 ){
+ /* If there has been exactly one prior match and this match
+ ** is for the right-hand table of a NATURAL JOIN or is in a
+ ** USING clause, then skip this match.
+ */
+ if( cnt==1 ){
+ if( pItem->jointype & JT_NATURAL ) continue;
+ if( nameInUsingClause(pItem->pUsing, zCol) ) continue;
+ }
+ cnt++;
+ pMatch = pItem;
+ /* Substitute the rowid (column -1) for the INTEGER PRIMARY KEY */
+ pExpr->iColumn = j==pTab->iPKey ? -1 : (i16)j;
+ break;
+ }
+ }
+ }
+ if( pMatch ){
+ pExpr->iTable = pMatch->iCursor;
+ pExpr->pTab = pMatch->pTab;
+ assert( (pMatch->jointype & JT_RIGHT)==0 ); /* RIGHT JOIN not (yet) supported */
+ if( (pMatch->jointype & JT_LEFT)!=0 ){
+ ExprSetProperty(pExpr, EP_CanBeNull);
+ }
+ pSchema = pExpr->pTab->pSchema;
+ }
+ } /* if( pSrcList ) */
+
+#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 && cntTab==0 && pParse->pTriggerTab!=0 ){
+ int op = pParse->eTriggerOp;
+ assert( op==TK_DELETE || op==TK_UPDATE || op==TK_INSERT );
+ if( op!=TK_DELETE && sqlite3StrICmp("new",zTab) == 0 ){
+ pExpr->iTable = 1;
+ pTab = pParse->pTriggerTab;
+ }else if( op!=TK_INSERT && sqlite3StrICmp("old",zTab)==0 ){
+ pExpr->iTable = 0;
+ pTab = pParse->pTriggerTab;
+ }else{
+ pTab = 0;
+ }
+
+ if( pTab ){
+ int iCol;
+ pSchema = pTab->pSchema;
+ cntTab++;
+ for(iCol=0, pCol=pTab->aCol; iCol<pTab->nCol; iCol++, pCol++){
+ if( sqlite3StrICmp(pCol->zName, zCol)==0 ){
+ if( iCol==pTab->iPKey ){
+ iCol = -1;
+ }
+ break;
+ }
+ }
+ if( iCol>=pTab->nCol && sqlite3IsRowid(zCol) && HasRowid(pTab) ){
+ /* IMP: R-51414-32910 */
+ /* IMP: R-44911-55124 */
+ iCol = -1;
+ }
+ if( iCol<pTab->nCol ){
+ cnt++;
+ if( iCol<0 ){
+ pExpr->affinity = SQLITE_AFF_INTEGER;
+ }else if( pExpr->iTable==0 ){
+ testcase( iCol==31 );
+ testcase( iCol==32 );
+ pParse->oldmask |= (iCol>=32 ? 0xffffffff : (((u32)1)<<iCol));
+ }else{
+ testcase( iCol==31 );
+ testcase( iCol==32 );
+ pParse->newmask |= (iCol>=32 ? 0xffffffff : (((u32)1)<<iCol));
+ }
+ pExpr->iColumn = (i16)iCol;
+ pExpr->pTab = pTab;
+ isTrigger = 1;
+ }
+ }
+ }
+#endif /* !defined(SQLITE_OMIT_TRIGGER) */
+
+ /*
+ ** Perhaps the name is a reference to the ROWID
+ */
+ if( cnt==0 && cntTab==1 && pMatch && sqlite3IsRowid(zCol)
+ && HasRowid(pMatch->pTab) ){
+ cnt = 1;
+ pExpr->iColumn = -1; /* IMP: R-44911-55124 */
+ 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.
+ **
+ ** The ability to use an output result-set column in the WHERE, GROUP BY,
+ ** or HAVING clauses, or as part of a larger expression in the ORDRE BY
+ ** clause is not standard SQL. This is a (goofy) SQLite extension, that
+ ** is supported for backwards compatibility only. TO DO: Issue a warning
+ ** on sqlite3_log() whenever the capability is used.
+ */
+ if( (pEList = pNC->pEList)!=0
+ && zTab==0
+ && cnt==0
+ ){
+ for(j=0; j<pEList->nExpr; j++){
+ char *zAs = pEList->a[j].zName;
+ if( zAs!=0 && sqlite3StrICmp(zAs, zCol)==0 ){
+ Expr *pOrig;
+ assert( pExpr->pLeft==0 && pExpr->pRight==0 );
+ assert( pExpr->x.pList==0 );
+ assert( pExpr->x.pSelect==0 );
+ pOrig = pEList->a[j].pExpr;
+ if( (pNC->ncFlags&NC_AllowAgg)==0 && ExprHasProperty(pOrig, EP_Agg) ){
+ sqlite3ErrorMsg(pParse, "misuse of aliased aggregate %s", zAs);
+ return WRC_Abort;
+ }
+ resolveAlias(pParse, pEList, j, pExpr, "", nSubquery);
+ cnt = 1;
+ pMatch = 0;
+ assert( zTab==0 && zDb==0 );
+ goto lookupname_end;
+ }
+ }
+ }
+
+ /* 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;
+ nSubquery++;
+ }
+ }
+
+ /*
+ ** 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 && ExprHasProperty(pExpr,EP_DblQuoted) ){
+ pExpr->op = TK_STRING;
+ pExpr->pTab = 0;
+ return WRC_Prune;
+ }
+
+ /*
+ ** 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);
+ }
+ pParse->checkSchema = 1;
+ 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==BMS-1 );
+ if( n>=BMS ){
+ n = BMS-1;
+ }
+ assert( pMatch->iCursor==pExpr->iTable );
+ pMatch->colUsed |= ((Bitmask)1)<<n;
+ }
+
+ /* Clean up and return
+ */
+ sqlite3ExprDelete(db, pExpr->pLeft);
+ pExpr->pLeft = 0;
+ sqlite3ExprDelete(db, pExpr->pRight);
+ pExpr->pRight = 0;
+ pExpr->op = (isTrigger ? TK_TRIGGER : TK_COLUMN);
+lookupname_end:
+ if( cnt==1 ){
+ assert( pNC!=0 );
+ if( pExpr->op!=TK_AS ){
+ sqlite3AuthRead(pParse, pExpr, pSchema, pNC->pSrcList);
+ }
+ /* 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 WRC_Prune;
+ } else {
+ return WRC_Abort;
+ }
+}
+
+/*
+** Allocate and return a pointer to an expression to load the column iCol
+** from datasource iSrc in SrcList pSrc.
+*/
+Expr *sqlite3CreateColumnExpr(sqlite3 *db, SrcList *pSrc, int iSrc, int iCol){
+ Expr *p = sqlite3ExprAlloc(db, TK_COLUMN, 0, 0);
+ if( p ){
+ struct SrcList_item *pItem = &pSrc->a[iSrc];
+ p->pTab = pItem->pTab;
+ p->iTable = pItem->iCursor;
+ if( p->pTab->iPKey==iCol ){
+ p->iColumn = -1;
+ }else{
+ p->iColumn = (ynVar)iCol;
+ testcase( iCol==BMS );
+ testcase( iCol==BMS-1 );
+ pItem->colUsed |= ((Bitmask)1)<<(iCol>=BMS ? BMS-1 : iCol);
+ }
+ ExprSetProperty(p, EP_Resolved);
+ }
+ return p;
+}
+
+/*
+** Report an error that an expression is not valid for a partial index WHERE
+** clause.
+*/
+static void notValidPartIdxWhere(
+ Parse *pParse, /* Leave error message here */
+ NameContext *pNC, /* The name context */
+ const char *zMsg /* Type of error */
+){
+ if( (pNC->ncFlags & NC_PartIdx)!=0 ){
+ sqlite3ErrorMsg(pParse, "%s prohibited in partial index WHERE clauses",
+ zMsg);
+ }
+}
+
+#ifndef SQLITE_OMIT_CHECK
+/*
+** Report an error that an expression is not valid for a CHECK constraint.
+*/
+static void notValidCheckConstraint(
+ Parse *pParse, /* Leave error message here */
+ NameContext *pNC, /* The name context */
+ const char *zMsg /* Type of error */
+){
+ if( (pNC->ncFlags & NC_IsCheck)!=0 ){
+ sqlite3ErrorMsg(pParse,"%s prohibited in CHECK constraints", zMsg);
+ }
+}
+#else
+# define notValidCheckConstraint(P,N,M)
+#endif
+
+/*
+** Expression p should encode a floating point value between 1.0 and 0.0.
+** Return 1024 times this value. Or return -1 if p is not a floating point
+** value between 1.0 and 0.0.
+*/
+static int exprProbability(Expr *p){
+ double r = -1.0;
+ if( p->op!=TK_FLOAT ) return -1;
+ sqlite3AtoF(p->u.zToken, &r, sqlite3Strlen30(p->u.zToken), SQLITE_UTF8);
+ assert( r>=0.0 );
+ if( r>1.0 ) return -1;
+ return (int)(r*1000.0);
+}
+
+/*
+** This routine is callback for sqlite3WalkExpr().
+**
+** 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 resolveExprStep(Walker *pWalker, Expr *pExpr){
+ NameContext *pNC;
+ Parse *pParse;
+
+ pNC = pWalker->u.pNC;
+ assert( pNC!=0 );
+ pParse = pNC->pParse;
+ assert( pParse==pWalker->pParse );
+
+ if( ExprHasProperty(pExpr, EP_Resolved) ) return WRC_Prune;
+ 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 ){
+
+#if defined(SQLITE_ENABLE_UPDATE_DELETE_LIMIT) && !defined(SQLITE_OMIT_SUBQUERY)
+ /* The special operator TK_ROW means use the rowid for the first
+ ** column in the FROM clause. This is used by the LIMIT and ORDER BY
+ ** clause processing on UPDATE and DELETE statements.
+ */
+ case TK_ROW: {
+ SrcList *pSrcList = pNC->pSrcList;
+ struct SrcList_item *pItem;
+ assert( pSrcList && pSrcList->nSrc==1 );
+ pItem = pSrcList->a;
+ pExpr->op = TK_COLUMN;
+ pExpr->pTab = pItem->pTab;
+ pExpr->iTable = pItem->iCursor;
+ pExpr->iColumn = -1;
+ pExpr->affinity = SQLITE_AFF_INTEGER;
+ break;
+ }
+#endif /* defined(SQLITE_ENABLE_UPDATE_DELETE_LIMIT) && !defined(SQLITE_OMIT_SUBQUERY) */
+
+ /* A lone identifier is the name of a column.
+ */
+ case TK_ID: {
+ return lookupName(pParse, 0, 0, pExpr->u.zToken, pNC, pExpr);
+ }
+
+ /* A table name and column name: ID.ID
+ ** Or a database, table and column: ID.ID.ID
+ */
+ case TK_DOT: {
+ const char *zColumn;
+ const char *zTable;
+ const char *zDb;
+ Expr *pRight;
+
+ /* if( pSrcList==0 ) break; */
+ pRight = pExpr->pRight;
+ if( pRight->op==TK_ID ){
+ zDb = 0;
+ zTable = pExpr->pLeft->u.zToken;
+ zColumn = pRight->u.zToken;
+ }else{
+ assert( pRight->op==TK_DOT );
+ zDb = pExpr->pLeft->u.zToken;
+ zTable = pRight->pLeft->u.zToken;
+ zColumn = pRight->pRight->u.zToken;
+ }
+ return lookupName(pParse, zDb, zTable, zColumn, pNC, pExpr);
+ }
+
+ /* Resolve function names
+ */
+ case TK_FUNCTION: {
+ ExprList *pList = pExpr->x.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 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 */
+ u8 enc = ENC(pParse->db); /* The database encoding */
+
+ assert( !ExprHasProperty(pExpr, EP_xIsSelect) );
+ notValidPartIdxWhere(pParse, pNC, "functions");
+ zId = pExpr->u.zToken;
+ nId = sqlite3Strlen30(zId);
+ pDef = sqlite3FindFunction(pParse->db, zId, nId, n, enc, 0);
+ if( pDef==0 ){
+ pDef = sqlite3FindFunction(pParse->db, zId, nId, -2, enc, 0);
+ if( pDef==0 ){
+ no_such_func = 1;
+ }else{
+ wrong_num_args = 1;
+ }
+ }else{
+ is_agg = pDef->xFunc==0;
+ if( pDef->funcFlags & SQLITE_FUNC_UNLIKELY ){
+ ExprSetProperty(pExpr, EP_Unlikely|EP_Skip);
+ if( n==2 ){
+ pExpr->iTable = exprProbability(pList->a[1].pExpr);
+ if( pExpr->iTable<0 ){
+ sqlite3ErrorMsg(pParse, "second argument to likelihood() must be a "
+ "constant between 0.0 and 1.0");
+ pNC->nErr++;
+ }
+ }else{
+ /* EVIDENCE-OF: R-61304-29449 The unlikely(X) function is equivalent to
+ ** likelihood(X, 0.0625).
+ ** EVIDENCE-OF: R-01283-11636 The unlikely(X) function is short-hand for
+ ** likelihood(X,0.0625).
+ ** EVIDENCE-OF: R-36850-34127 The likely(X) function is short-hand for
+ ** likelihood(X,0.9375).
+ ** EVIDENCE-OF: R-53436-40973 The likely(X) function is equivalent to
+ ** likelihood(X,0.9375). */
+ /* TUNING: unlikely() probability is 0.0625. likely() is 0.9375 */
+ pExpr->iTable = pDef->zName[0]=='u' ? 62 : 938;
+ }
+ }
+#ifndef SQLITE_OMIT_AUTHORIZATION
+ 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 WRC_Prune;
+ }
+#endif
+ if( pDef->funcFlags & SQLITE_FUNC_CONSTANT ) ExprSetProperty(pExpr,EP_Constant);
+ }
+ if( is_agg && (pNC->ncFlags & NC_AllowAgg)==0 ){
+ sqlite3ErrorMsg(pParse, "misuse of aggregate function %.*s()", nId,zId);
+ pNC->nErr++;
+ is_agg = 0;
+ }else if( no_such_func && pParse->db->init.busy==0 ){
+ 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 ) pNC->ncFlags &= ~NC_AllowAgg;
+ sqlite3WalkExprList(pWalker, pList);
+ if( is_agg ){
+ NameContext *pNC2 = pNC;
+ pExpr->op = TK_AGG_FUNCTION;
+ pExpr->op2 = 0;
+ while( pNC2 && !sqlite3FunctionUsesThisSrc(pExpr, pNC2->pSrcList) ){
+ pExpr->op2++;
+ pNC2 = pNC2->pNext;
+ }
+ assert( pDef!=0 );
+ if( pNC2 ){
+ assert( SQLITE_FUNC_MINMAX==NC_MinMaxAgg );
+ testcase( (pDef->funcFlags & SQLITE_FUNC_MINMAX)!=0 );
+ pNC2->ncFlags |= NC_HasAgg | (pDef->funcFlags & SQLITE_FUNC_MINMAX);
+
+ }
+ pNC->ncFlags |= NC_AllowAgg;
+ }
+ /* FIX ME: Compute pExpr->affinity based on the expected return
+ ** type of the function
+ */
+ return WRC_Prune;
+ }
+#ifndef SQLITE_OMIT_SUBQUERY
+ case TK_SELECT:
+ case TK_EXISTS: testcase( pExpr->op==TK_EXISTS );
+#endif
+ case TK_IN: {
+ testcase( pExpr->op==TK_IN );
+ if( ExprHasProperty(pExpr, EP_xIsSelect) ){
+ int nRef = pNC->nRef;
+ notValidCheckConstraint(pParse, pNC, "subqueries");
+ notValidPartIdxWhere(pParse, pNC, "subqueries");
+ sqlite3WalkSelect(pWalker, pExpr->x.pSelect);
+ assert( pNC->nRef>=nRef );
+ if( nRef!=pNC->nRef ){
+ ExprSetProperty(pExpr, EP_VarSelect);
+ }
+ }
+ break;
+ }
+ case TK_VARIABLE: {
+ notValidCheckConstraint(pParse, pNC, "parameters");
+ notValidPartIdxWhere(pParse, pNC, "parameters");
+ break;
+ }
+ }
+ return (pParse->nErr || pParse->db->mallocFailed) ? WRC_Abort : WRC_Continue;
+}
+
+/*
+** pEList is a list of expressions which are really the result set of the
+** a SELECT statement. pE is a term in an ORDER BY or GROUP BY clause.
+** This routine checks to see if pE is a simple identifier which corresponds
+** to the AS-name of one of the terms of the expression list. If it is,
+** this routine return an integer between 1 and N where N is the number of
+** elements in pEList, corresponding to the matching entry. If there is
+** no match, or if pE is not a simple identifier, then this routine
+** return 0.
+**
+** pEList has been resolved. pE has not.
+*/
+static int resolveAsName(
+ Parse *pParse, /* Parsing context for error messages */
+ ExprList *pEList, /* List of expressions to scan */
+ Expr *pE /* Expression we are trying to match */
+){
+ int i; /* Loop counter */
+
+ UNUSED_PARAMETER(pParse);
+
+ if( pE->op==TK_ID ){
+ char *zCol = pE->u.zToken;
+ for(i=0; i<pEList->nExpr; i++){
+ char *zAs = pEList->a[i].zName;
+ if( zAs!=0 && sqlite3StrICmp(zAs, zCol)==0 ){
+ return i+1;
+ }
+ }
+ }
+ return 0;
+}
+
+/*
+** pE is a pointer to an expression which is a single term in the
+** ORDER BY of a compound SELECT. The expression has not been
+** name resolved.
+**
+** At the point this routine is called, we already know that the
+** ORDER BY term is not an integer index into the result set. That
+** case is handled by the calling routine.
+**
+** Attempt to match pE against result set columns in the left-most
+** SELECT statement. Return the index i of the matching column,
+** as an indication to the caller that it should sort by the i-th column.
+** The left-most column is 1. In other words, the value returned is the
+** same integer value that would be used in the SQL statement to indicate
+** the column.
+**
+** If there is no match, return 0. Return -1 if an error occurs.
+*/
+static int resolveOrderByTermToExprList(
+ Parse *pParse, /* Parsing context for error messages */
+ Select *pSelect, /* The SELECT statement with the ORDER BY clause */
+ Expr *pE /* The specific ORDER BY term */
+){
+ int i; /* Loop counter */
+ ExprList *pEList; /* The columns of the result set */
+ NameContext nc; /* Name context for resolving pE */
+ sqlite3 *db; /* Database connection */
+ int rc; /* Return code from subprocedures */
+ u8 savedSuppErr; /* Saved value of db->suppressErr */
+
+ assert( sqlite3ExprIsInteger(pE, &i)==0 );
+ pEList = pSelect->pEList;
+
+ /* Resolve all names in the ORDER BY term expression
+ */
+ memset(&nc, 0, sizeof(nc));
+ nc.pParse = pParse;
+ nc.pSrcList = pSelect->pSrc;
+ nc.pEList = pEList;
+ nc.ncFlags = NC_AllowAgg;
+ nc.nErr = 0;
+ db = pParse->db;
+ savedSuppErr = db->suppressErr;
+ db->suppressErr = 1;
+ rc = sqlite3ResolveExprNames(&nc, pE);
+ db->suppressErr = savedSuppErr;
+ if( rc ) return 0;
+
+ /* Try to match the ORDER BY expression against an expression
+ ** in the result set. Return an 1-based index of the matching
+ ** result-set entry.
+ */
+ for(i=0; i<pEList->nExpr; i++){
+ if( sqlite3ExprCompare(pEList->a[i].pExpr, pE, -1)<2 ){
+ return i+1;
+ }
+ }
+
+ /* If no match, return 0. */
+ return 0;
+}
+
+/*
+** Generate an ORDER BY or GROUP BY term out-of-range error.
+*/
+static void resolveOutOfRangeError(
+ Parse *pParse, /* The error context into which to write the error */
+ const char *zType, /* "ORDER" or "GROUP" */
+ int i, /* The index (1-based) of the term out of range */
+ int mx /* Largest permissible value of i */
+){
+ sqlite3ErrorMsg(pParse,
+ "%r %s BY term out of range - should be "
+ "between 1 and %d", i, zType, mx);
+}
+
+/*
+** Analyze the ORDER BY clause in a compound SELECT statement. Modify
+** each term of the ORDER BY clause is a constant integer between 1
+** and N where N is the number of columns in the compound SELECT.
+**
+** ORDER BY terms that are already an integer between 1 and N are
+** unmodified. ORDER BY terms that are integers outside the range of
+** 1 through N generate an error. ORDER BY terms that are expressions
+** are matched against result set expressions of compound SELECT
+** beginning with the left-most SELECT and working toward the right.
+** At the first match, the ORDER BY expression is transformed into
+** the integer column number.
+**
+** Return the number of errors seen.
+*/
+static int resolveCompoundOrderBy(
+ Parse *pParse, /* Parsing context. Leave error messages here */
+ Select *pSelect /* The SELECT statement containing the ORDER BY */
+){
+ int i;
+ ExprList *pOrderBy;
+ ExprList *pEList;
+ sqlite3 *db;
+ int moreToDo = 1;
+
+ pOrderBy = pSelect->pOrderBy;
+ if( pOrderBy==0 ) return 0;
+ db = pParse->db;
+#if SQLITE_MAX_COLUMN
+ if( pOrderBy->nExpr>db->aLimit[SQLITE_LIMIT_COLUMN] ){
+ sqlite3ErrorMsg(pParse, "too many terms in ORDER BY clause");
+ return 1;
+ }
+#endif
+ for(i=0; i<pOrderBy->nExpr; i++){
+ pOrderBy->a[i].done = 0;
+ }
+ pSelect->pNext = 0;
+ while( pSelect->pPrior ){
+ pSelect->pPrior->pNext = pSelect;
+ pSelect = pSelect->pPrior;
+ }
+ while( pSelect && moreToDo ){
+ struct ExprList_item *pItem;
+ moreToDo = 0;
+ pEList = pSelect->pEList;
+ assert( pEList!=0 );
+ for(i=0, pItem=pOrderBy->a; i<pOrderBy->nExpr; i++, pItem++){
+ int iCol = -1;
+ Expr *pE, *pDup;
+ if( pItem->done ) continue;
+ pE = sqlite3ExprSkipCollate(pItem->pExpr);
+ if( sqlite3ExprIsInteger(pE, &iCol) ){
+ if( iCol<=0 || iCol>pEList->nExpr ){
+ resolveOutOfRangeError(pParse, "ORDER", i+1, pEList->nExpr);
+ return 1;
+ }
+ }else{
+ iCol = resolveAsName(pParse, pEList, pE);
+ if( iCol==0 ){
+ pDup = sqlite3ExprDup(db, pE, 0);
+ if( !db->mallocFailed ){
+ assert(pDup);
+ iCol = resolveOrderByTermToExprList(pParse, pSelect, pDup);
+ }
+ sqlite3ExprDelete(db, pDup);
+ }
+ }
+ if( iCol>0 ){
+ /* Convert the ORDER BY term into an integer column number iCol,
+ ** taking care to preserve the COLLATE clause if it exists */
+ Expr *pNew = sqlite3Expr(db, TK_INTEGER, 0);
+ if( pNew==0 ) return 1;
+ pNew->flags |= EP_IntValue;
+ pNew->u.iValue = iCol;
+ if( pItem->pExpr==pE ){
+ pItem->pExpr = pNew;
+ }else{
+ assert( pItem->pExpr->op==TK_COLLATE );
+ assert( pItem->pExpr->pLeft==pE );
+ pItem->pExpr->pLeft = pNew;
+ }
+ sqlite3ExprDelete(db, pE);
+ pItem->u.x.iOrderByCol = (u16)iCol;
+ pItem->done = 1;
+ }else{
+ moreToDo = 1;
+ }
+ }
+ pSelect = pSelect->pNext;
+ }
+ for(i=0; i<pOrderBy->nExpr; i++){
+ if( pOrderBy->a[i].done==0 ){
+ sqlite3ErrorMsg(pParse, "%r ORDER BY term does not match any "
+ "column in the result set", i+1);
+ return 1;
+ }
+ }
+ return 0;
+}
+
+/*
+** Check every term in the ORDER BY or GROUP BY clause pOrderBy of
+** the SELECT statement pSelect. If any term is reference to a
+** result set expression (as determined by the ExprList.a.u.x.iOrderByCol
+** field) then convert that term into a copy of the corresponding result set
+** column.
+**
+** If any errors are detected, add an error message to pParse and
+** return non-zero. Return zero if no errors are seen.
+*/
+int sqlite3ResolveOrderGroupBy(
+ Parse *pParse, /* Parsing context. Leave error messages here */
+ Select *pSelect, /* The SELECT statement containing the clause */
+ ExprList *pOrderBy, /* The ORDER BY or GROUP BY clause to be processed */
+ const char *zType /* "ORDER" or "GROUP" */
+){
+ int i;
+ sqlite3 *db = pParse->db;
+ ExprList *pEList;
+ struct ExprList_item *pItem;
+
+ if( pOrderBy==0 || pParse->db->mallocFailed ) return 0;
+#if SQLITE_MAX_COLUMN
+ if( pOrderBy->nExpr>db->aLimit[SQLITE_LIMIT_COLUMN] ){
+ sqlite3ErrorMsg(pParse, "too many terms in %s BY clause", zType);
+ return 1;
+ }
+#endif
+ pEList = pSelect->pEList;
+ assert( pEList!=0 ); /* sqlite3SelectNew() guarantees this */
+ for(i=0, pItem=pOrderBy->a; i<pOrderBy->nExpr; i++, pItem++){
+ if( pItem->u.x.iOrderByCol ){
+ if( pItem->u.x.iOrderByCol>pEList->nExpr ){
+ resolveOutOfRangeError(pParse, zType, i+1, pEList->nExpr);
+ return 1;
+ }
+ resolveAlias(pParse, pEList, pItem->u.x.iOrderByCol-1, pItem->pExpr, zType,0);
+ }
+ }
+ return 0;
+}
+
+/*
+** pOrderBy is an ORDER BY or GROUP BY clause in SELECT statement pSelect.
+** The Name context of the SELECT statement is pNC. zType is either
+** "ORDER" or "GROUP" depending on which type of clause pOrderBy is.
+**
+** This routine resolves each term of the clause into an expression.
+** If the order-by term is an integer I between 1 and N (where N is the
+** number of columns in the result set of the SELECT) then the expression
+** in the resolution is a copy of the I-th result-set expression. If
+** the order-by term is an identifier that corresponds to the AS-name of
+** a result-set expression, then the term resolves to a copy of the
+** result-set expression. Otherwise, the expression is resolved in
+** the usual way - using sqlite3ResolveExprNames().
+**
+** This routine returns the number of errors. If errors occur, then
+** an appropriate error message might be left in pParse. (OOM errors
+** excepted.)
+*/
+static int resolveOrderGroupBy(
+ NameContext *pNC, /* The name context of the SELECT statement */
+ Select *pSelect, /* The SELECT statement holding pOrderBy */
+ ExprList *pOrderBy, /* An ORDER BY or GROUP BY clause to resolve */
+ const char *zType /* Either "ORDER" or "GROUP", as appropriate */
+){
+ int i, j; /* Loop counters */
+ int iCol; /* Column number */
+ struct ExprList_item *pItem; /* A term of the ORDER BY clause */
+ Parse *pParse; /* Parsing context */
+ int nResult; /* Number of terms in the result set */
+
+ if( pOrderBy==0 ) return 0;
+ nResult = pSelect->pEList->nExpr;
+ pParse = pNC->pParse;
+ for(i=0, pItem=pOrderBy->a; i<pOrderBy->nExpr; i++, pItem++){
+ Expr *pE = pItem->pExpr;
+ Expr *pE2 = sqlite3ExprSkipCollate(pE);
+ if( zType[0]!='G' ){
+ iCol = resolveAsName(pParse, pSelect->pEList, pE2);
+ if( iCol>0 ){
+ /* If an AS-name match is found, mark this ORDER BY column as being
+ ** a copy of the iCol-th result-set column. The subsequent call to
+ ** sqlite3ResolveOrderGroupBy() will convert the expression to a
+ ** copy of the iCol-th result-set expression. */
+ pItem->u.x.iOrderByCol = (u16)iCol;
+ continue;
+ }
+ }
+ if( sqlite3ExprIsInteger(pE2, &iCol) ){
+ /* The ORDER BY term is an integer constant. Again, set the column
+ ** number so that sqlite3ResolveOrderGroupBy() will convert the
+ ** order-by term to a copy of the result-set expression */
+ if( iCol<1 || iCol>0xffff ){
+ resolveOutOfRangeError(pParse, zType, i+1, nResult);
+ return 1;
+ }
+ pItem->u.x.iOrderByCol = (u16)iCol;
+ continue;
+ }
+
+ /* Otherwise, treat the ORDER BY term as an ordinary expression */
+ pItem->u.x.iOrderByCol = 0;
+ if( sqlite3ResolveExprNames(pNC, pE) ){
+ return 1;
+ }
+ for(j=0; j<pSelect->pEList->nExpr; j++){
+ if( sqlite3ExprCompare(pE, pSelect->pEList->a[j].pExpr, -1)==0 ){
+ pItem->u.x.iOrderByCol = j+1;
+ }
+ }
+ }
+ return sqlite3ResolveOrderGroupBy(pParse, pSelect, pOrderBy, zType);
+}
+
+/*
+** Resolve names in the SELECT statement p and all of its descendants.
+*/
+static int resolveSelectStep(Walker *pWalker, Select *p){
+ NameContext *pOuterNC; /* Context that contains this SELECT */
+ NameContext sNC; /* Name context of this SELECT */
+ int isCompound; /* True if p is a compound select */
+ int nCompound; /* Number of compound terms processed so far */
+ Parse *pParse; /* Parsing context */
+ ExprList *pEList; /* Result set expression list */
+ int i; /* Loop counter */
+ ExprList *pGroupBy; /* The GROUP BY clause */
+ Select *pLeftmost; /* Left-most of SELECT of a compound */
+ sqlite3 *db; /* Database connection */
+
+
+ assert( p!=0 );
+ if( p->selFlags & SF_Resolved ){
+ return WRC_Prune;
+ }
+ pOuterNC = pWalker->u.pNC;
+ pParse = pWalker->pParse;
+ db = pParse->db;
+
+ /* Normally sqlite3SelectExpand() will be called first and will have
+ ** already expanded this SELECT. However, if this is a subquery within
+ ** an expression, sqlite3ResolveExprNames() will be called without a
+ ** prior call to sqlite3SelectExpand(). When that happens, let
+ ** sqlite3SelectPrep() do all of the processing for this SELECT.
+ ** sqlite3SelectPrep() will invoke both sqlite3SelectExpand() and
+ ** this routine in the correct order.
+ */
+ if( (p->selFlags & SF_Expanded)==0 ){
+ sqlite3SelectPrep(pParse, p, pOuterNC);
+ return (pParse->nErr || db->mallocFailed) ? WRC_Abort : WRC_Prune;
+ }
+
+ isCompound = p->pPrior!=0;
+ nCompound = 0;
+ pLeftmost = p;
+ while( p ){
+ assert( (p->selFlags & SF_Expanded)!=0 );
+ assert( (p->selFlags & SF_Resolved)==0 );
+ p->selFlags |= SF_Resolved;
+
+ /* Resolve the expressions in the LIMIT and OFFSET clauses. These
+ ** are not allowed to refer to any names, so pass an empty NameContext.
+ */
+ memset(&sNC, 0, sizeof(sNC));
+ sNC.pParse = pParse;
+ if( sqlite3ResolveExprNames(&sNC, p->pLimit) ||
+ sqlite3ResolveExprNames(&sNC, p->pOffset) ){
+ return WRC_Abort;
+ }
+
+ /* Recursively resolve names in all subqueries
+ */
+ for(i=0; i<p->pSrc->nSrc; i++){
+ struct SrcList_item *pItem = &p->pSrc->a[i];
+ if( pItem->pSelect ){
+ NameContext *pNC; /* Used to iterate name contexts */
+ int nRef = 0; /* Refcount for pOuterNC and outer contexts */
+ const char *zSavedContext = pParse->zAuthContext;
+
+ /* Count the total number of references to pOuterNC and all of its
+ ** parent contexts. After resolving references to expressions in
+ ** pItem->pSelect, check if this value has changed. If so, then
+ ** SELECT statement pItem->pSelect must be correlated. Set the
+ ** pItem->isCorrelated flag if this is the case. */
+ for(pNC=pOuterNC; pNC; pNC=pNC->pNext) nRef += pNC->nRef;
+
+ if( pItem->zName ) pParse->zAuthContext = pItem->zName;
+ sqlite3ResolveSelectNames(pParse, pItem->pSelect, pOuterNC);
+ pParse->zAuthContext = zSavedContext;
+ if( pParse->nErr || db->mallocFailed ) return WRC_Abort;
+
+ for(pNC=pOuterNC; pNC; pNC=pNC->pNext) nRef -= pNC->nRef;
+ assert( pItem->isCorrelated==0 && nRef<=0 );
+ pItem->isCorrelated = (nRef!=0);
+ }
+ }
+
+ /* Set up the local name-context to pass to sqlite3ResolveExprNames() to
+ ** resolve the result-set expression list.
+ */
+ sNC.ncFlags = NC_AllowAgg;
+ sNC.pSrcList = p->pSrc;
+ sNC.pNext = pOuterNC;
+
+ /* Resolve names in the result set. */
+ pEList = p->pEList;
+ assert( pEList!=0 );
+ for(i=0; i<pEList->nExpr; i++){
+ Expr *pX = pEList->a[i].pExpr;
+ if( sqlite3ResolveExprNames(&sNC, pX) ){
+ return WRC_Abort;
+ }
+ }
+
+ /* If there are no aggregate functions in the result-set, and no GROUP BY
+ ** expression, do not allow aggregates in any of the other expressions.
+ */
+ assert( (p->selFlags & SF_Aggregate)==0 );
+ pGroupBy = p->pGroupBy;
+ if( pGroupBy || (sNC.ncFlags & NC_HasAgg)!=0 ){
+ assert( NC_MinMaxAgg==SF_MinMaxAgg );
+ p->selFlags |= SF_Aggregate | (sNC.ncFlags&NC_MinMaxAgg);
+ }else{
+ sNC.ncFlags &= ~NC_AllowAgg;
+ }
+
+ /* If a HAVING clause is present, then there must be a GROUP BY clause.
+ */
+ if( p->pHaving && !pGroupBy ){
+ sqlite3ErrorMsg(pParse, "a GROUP BY clause is required before HAVING");
+ return WRC_Abort;
+ }
+
+ /* Add the output column list to the name-context before parsing the
+ ** other expressions in the SELECT statement. This is so that
+ ** expressions in the WHERE clause (etc.) can refer to expressions by
+ ** aliases in the result set.
+ **
+ ** Minor point: If this is the case, then the expression will be
+ ** re-evaluated for each reference to it.
+ */
+ sNC.pEList = p->pEList;
+ if( sqlite3ResolveExprNames(&sNC, p->pHaving) ) return WRC_Abort;
+ if( sqlite3ResolveExprNames(&sNC, p->pWhere) ) return WRC_Abort;
+
+ /* The ORDER BY and GROUP BY clauses may not refer to terms in
+ ** outer queries
+ */
+ sNC.pNext = 0;
+ sNC.ncFlags |= NC_AllowAgg;
+
+ /* Process the ORDER BY clause for singleton SELECT statements.
+ ** The ORDER BY clause for compounds SELECT statements is handled
+ ** below, after all of the result-sets for all of the elements of
+ ** the compound have been resolved.
+ */
+ if( !isCompound && resolveOrderGroupBy(&sNC, p, p->pOrderBy, "ORDER") ){
+ return WRC_Abort;
+ }
+ if( db->mallocFailed ){
+ return WRC_Abort;
+ }
+
+ /* Resolve the GROUP BY clause. At the same time, make sure
+ ** the GROUP BY clause does not contain aggregate functions.
+ */
+ if( pGroupBy ){
+ struct ExprList_item *pItem;
+
+ if( resolveOrderGroupBy(&sNC, p, pGroupBy, "GROUP") || db->mallocFailed ){
+ return WRC_Abort;
+ }
+ for(i=0, pItem=pGroupBy->a; i<pGroupBy->nExpr; i++, pItem++){
+ if( ExprHasProperty(pItem->pExpr, EP_Agg) ){
+ sqlite3ErrorMsg(pParse, "aggregate functions are not allowed in "
+ "the GROUP BY clause");
+ return WRC_Abort;
+ }
+ }
+ }
+
+ /* Advance to the next term of the compound
+ */
+ p = p->pPrior;
+ nCompound++;
+ }
+
+ /* Resolve the ORDER BY on a compound SELECT after all terms of
+ ** the compound have been resolved.
+ */
+ if( isCompound && resolveCompoundOrderBy(pParse, pLeftmost) ){
+ return WRC_Abort;
+ }
+
+ return WRC_Prune;
+}
+
+/*
+** This routine walks an expression tree and resolves references to
+** table columns and result-set columns. At the same time, do error
+** checking on function usage and set a flag if any aggregate functions
+** are seen.
+**
+** To resolve table columns references we look for nodes (or subtrees) of the
+** form X.Y.Z or Y.Z or just Z where
+**
+** X: The name of a database. Ex: "main" or "temp" or
+** the symbolic name assigned to an ATTACH-ed database.
+**
+** Y: The name of a table in a FROM clause. Or in a trigger
+** one of the special names "old" or "new".
+**
+** Z: The name of a column in table Y.
+**
+** The node at the root of the subtree is modified as follows:
+**
+** Expr.op Changed to TK_COLUMN
+** Expr.pTab Points to the Table object for X.Y
+** Expr.iColumn The column index in X.Y. -1 for the rowid.
+** Expr.iTable The VDBE cursor number for X.Y
+**
+**
+** To resolve result-set references, look for expression nodes of the
+** form Z (with no X and Y prefix) where the Z matches the right-hand
+** size of an AS clause in the result-set of a SELECT. The Z expression
+** is replaced by a copy of the left-hand side of the result-set expression.
+** Table-name and function resolution occurs on the substituted expression
+** tree. For example, in:
+**
+** SELECT a+b AS x, c+d AS y FROM t1 ORDER BY x;
+**
+** The "x" term of the order by is replaced by "a+b" to render:
+**
+** SELECT a+b AS x, c+d AS y FROM t1 ORDER BY a+b;
+**
+** Function calls are checked to make sure that the function is
+** defined and that the correct number of arguments are specified.
+** If the function is an aggregate function, then the NC_HasAgg flag is
+** set and the opcode is changed from TK_FUNCTION to TK_AGG_FUNCTION.
+** If an expression contains aggregate functions then the EP_Agg
+** property on the expression is set.
+**
+** An error message is left in pParse if anything is amiss. The number
+** if errors is returned.
+*/
+int sqlite3ResolveExprNames(
+ NameContext *pNC, /* Namespace to resolve expressions in. */
+ Expr *pExpr /* The expression to be analyzed. */
+){
+ u16 savedHasAgg;
+ Walker w;
+
+ if( pExpr==0 ) return 0;
+#if SQLITE_MAX_EXPR_DEPTH>0
+ {
+ Parse *pParse = pNC->pParse;
+ if( sqlite3ExprCheckHeight(pParse, pExpr->nHeight+pNC->pParse->nHeight) ){
+ return 1;
+ }
+ pParse->nHeight += pExpr->nHeight;
+ }
+#endif
+ savedHasAgg = pNC->ncFlags & (NC_HasAgg|NC_MinMaxAgg);
+ pNC->ncFlags &= ~(NC_HasAgg|NC_MinMaxAgg);
+ memset(&w, 0, sizeof(w));
+ w.xExprCallback = resolveExprStep;
+ w.xSelectCallback = resolveSelectStep;
+ w.pParse = pNC->pParse;
+ w.u.pNC = pNC;
+ sqlite3WalkExpr(&w, pExpr);
+#if SQLITE_MAX_EXPR_DEPTH>0
+ pNC->pParse->nHeight -= pExpr->nHeight;
+#endif
+ if( pNC->nErr>0 || w.pParse->nErr>0 ){
+ ExprSetProperty(pExpr, EP_Error);
+ }
+ if( pNC->ncFlags & NC_HasAgg ){
+ ExprSetProperty(pExpr, EP_Agg);
+ }
+ pNC->ncFlags |= savedHasAgg;
+ return ExprHasProperty(pExpr, EP_Error);
+}
+
+
+/*
+** Resolve all names in all expressions of a SELECT and in all
+** decendents of the SELECT, including compounds off of p->pPrior,
+** subqueries in expressions, and subqueries used as FROM clause
+** terms.
+**
+** See sqlite3ResolveExprNames() for a description of the kinds of
+** transformations that occur.
+**
+** All SELECT statements should have been expanded using
+** sqlite3SelectExpand() prior to invoking this routine.
+*/
+void sqlite3ResolveSelectNames(
+ Parse *pParse, /* The parser context */
+ Select *p, /* The SELECT statement being coded. */
+ NameContext *pOuterNC /* Name context for parent SELECT statement */
+){
+ Walker w;
+
+ assert( p!=0 );
+ memset(&w, 0, sizeof(w));
+ w.xExprCallback = resolveExprStep;
+ w.xSelectCallback = resolveSelectStep;
+ w.pParse = pParse;
+ w.u.pNC = pOuterNC;
+ sqlite3WalkSelect(&w, p);
+}
+
+/*
+** Resolve names in expressions that can only reference a single table:
+**
+** * CHECK constraints
+** * WHERE clauses on partial indices
+**
+** The Expr.iTable value for Expr.op==TK_COLUMN nodes of the expression
+** is set to -1 and the Expr.iColumn value is set to the column number.
+**
+** Any errors cause an error message to be set in pParse.
+*/
+void sqlite3ResolveSelfReference(
+ Parse *pParse, /* Parsing context */
+ Table *pTab, /* The table being referenced */
+ int type, /* NC_IsCheck or NC_PartIdx */
+ Expr *pExpr, /* Expression to resolve. May be NULL. */
+ ExprList *pList /* Expression list to resolve. May be NUL. */
+){
+ SrcList sSrc; /* Fake SrcList for pParse->pNewTable */
+ NameContext sNC; /* Name context for pParse->pNewTable */
+ int i; /* Loop counter */
+
+ assert( type==NC_IsCheck || type==NC_PartIdx );
+ memset(&sNC, 0, sizeof(sNC));
+ memset(&sSrc, 0, sizeof(sSrc));
+ sSrc.nSrc = 1;
+ sSrc.a[0].zName = pTab->zName;
+ sSrc.a[0].pTab = pTab;
+ sSrc.a[0].iCursor = -1;
+ sNC.pParse = pParse;
+ sNC.pSrcList = &sSrc;
+ sNC.ncFlags = type;
+ if( sqlite3ResolveExprNames(&sNC, pExpr) ) return;
+ if( pList ){
+ for(i=0; i<pList->nExpr; i++){
+ if( sqlite3ResolveExprNames(&sNC, pList->a[i].pExpr) ){
+ return;
+ }
+ }
+ }
+}
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