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

Issue 3108030: Move bundled copy of sqlite one level deeper to better separate it... (Closed) Base URL: svn://svn.chromium.org/chrome/trunk/src/
Patch Set: Created 10 years, 4 months ago
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Index: third_party/sqlite/src/resolve.c
===================================================================
--- third_party/sqlite/src/resolve.c (revision 56608)
+++ third_party/sqlite/src/resolve.c (working copy)
@@ -1,1168 +0,0 @@
-/*
-** 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.
-**
-** $Id: resolve.c,v 1.30 2009/06/15 23:15:59 drh Exp $
-*/
-#include "sqliteInt.h"
-#include <stdlib.h>
-#include <string.h>
-
-/*
-** 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.
-**
-** Hack: 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. We might fix this someday. Or
-** then again, we might not...
-*/
-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 "" */
-){
- 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;
- if( pOrig->op!=TK_COLUMN && zType[0]!='G' ){
- pDup = sqlite3ExprDup(db, pOrig, 0);
- pDup = sqlite3PExpr(pParse, TK_AS, pDup, 0, 0);
- if( pDup==0 ) return;
- if( pEList->a[iCol].iAlias==0 ){
- pEList->a[iCol].iAlias = (u16)(++pParse->nAlias);
- }
- pDup->iTable = pEList->a[iCol].iAlias;
- }else if( ExprHasProperty(pOrig, EP_IntValue) || pOrig->u.zToken==0 ){
- pDup = sqlite3ExprDup(db, pOrig, 0);
- if( pDup==0 ) return;
- }else{
- char *zToken = pOrig->u.zToken;
- assert( zToken!=0 );
- pOrig->u.zToken = 0;
- pDup = sqlite3ExprDup(db, pOrig, 0);
- pOrig->u.zToken = zToken;
- if( pDup==0 ) return;
- assert( (pDup->flags & (EP_Reduced|EP_TokenOnly))==0 );
- pDup->flags2 |= EP2_MallocedToken;
- pDup->u.zToken = sqlite3DbStrDup(db, zToken);
- }
- if( pExpr->flags & EP_ExpCollate ){
- pDup->pColl = pExpr->pColl;
- pDup->flags |= EP_ExpCollate;
- }
- sqlite3ExprClear(db, pExpr);
- memcpy(pExpr, pDup, sizeof(*pExpr));
- sqlite3DbFree(db, pDup);
-}
-
-/*
-** 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 */
- 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;
-
- assert( pNC ); /* the name context cannot be NULL. */
- assert( zCol ); /* The Z in X.Y.Z cannot be NULL */
- assert( ~ExprHasAnyProperty(pExpr, EP_TokenOnly|EP_Reduced) );
-
- /* Initialize the node to no-match */
- pExpr->iTable = -1;
- pExpr->pTab = 0;
- ExprSetIrreducible(pExpr);
-
- /* 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++){
- Table *pTab;
- int iDb;
- Column *pCol;
-
- pTab = pItem->pTab;
- assert( pTab!=0 && pTab->zName!=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( NEVER(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;
- pExpr->pTab = pTab;
- pSchema = pTab->pSchema;
- pMatch = pItem;
- }
- for(j=0, pCol=pTab->aCol; j<pTab->nCol; j++, pCol++){
- if( sqlite3StrICmp(pCol->zName, zCol)==0 ){
- IdList *pUsing;
- cnt++;
- pExpr->iTable = pItem->iCursor;
- pExpr->pTab = pTab;
- pMatch = pItem;
- pSchema = pTab->pSchema;
- /* Substitute the rowid (column -1) for the INTEGER PRIMARY KEY */
- pExpr->iColumn = j==pTab->iPKey ? -1 : (i16)j;
- 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->pTriggerTab!=0 ){
- int op = pParse->eTriggerOp;
- Table *pTab = 0;
- 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;
- }
-
- if( pTab ){
- int iCol;
- pSchema = pTab->pSchema;
- cntTab++;
- if( sqlite3IsRowid(zCol) ){
- iCol = -1;
- }else{
- for(iCol=0; iCol<pTab->nCol; iCol++){
- Column *pCol = &pTab->aCol[iCol];
- if( sqlite3StrICmp(pCol->zName, zCol)==0 ){
- if( iCol==pTab->iPKey ){
- iCol = -1;
- }
- break;
- }
- }
- }
- 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));
- }
- 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 && 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 *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->allowAgg && ExprHasProperty(pOrig, EP_Agg) ){
- sqlite3ErrorMsg(pParse, "misuse of aliased aggregate %s", zAs);
- return WRC_Abort;
- }
- resolveAlias(pParse, pEList, j, pExpr, "");
- 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;
- }
- }
-
- /*
- ** 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);
- }
- 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 );
- 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;
- }
-}
-
-/*
-** 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( ExprHasAnyProperty(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_CONST_FUNC:
- 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 */
-
- testcase( pExpr->op==TK_CONST_FUNC );
- assert( !ExprHasProperty(pExpr, EP_xIsSelect) );
- 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, -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 WRC_Prune;
- }
- }
-#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;
- sqlite3WalkExprList(pWalker, pList);
- if( is_agg ) pNC->allowAgg = 1;
- /* 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;
-#ifndef SQLITE_OMIT_CHECK
- if( pNC->isCheck ){
- sqlite3ErrorMsg(pParse,"subqueries prohibited in CHECK constraints");
- }
-#endif
- sqlite3WalkSelect(pWalker, pExpr->x.pSelect);
- 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 (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 */
-
- 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.allowAgg = 1;
- nc.nErr = 0;
- if( sqlite3ResolveExprNames(&nc, pE) ){
- sqlite3ErrorClear(pParse);
- 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) ){
- 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 = 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 ){
- CollSeq *pColl = pE->pColl;
- int flags = pE->flags & EP_ExpCollate;
- sqlite3ExprDelete(db, pE);
- pItem->pExpr = pE = sqlite3Expr(db, TK_INTEGER, 0);
- if( pE==0 ) return 1;
- pE->pColl = pColl;
- pE->flags |= EP_IntValue | flags;
- pE->u.iValue = iCol;
- pItem->iCol = (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.iCol 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->iCol ){
- if( pItem->iCol>pEList->nExpr ){
- resolveOutOfRangeError(pParse, zType, i+1, pEList->nExpr);
- return 1;
- }
- resolveAlias(pParse, pEList, pItem->iCol-1, pItem->pExpr, zType);
- }
- }
- 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 identify 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; /* Loop counter */
- 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;
- iCol = resolveAsName(pParse, pSelect->pEList, pE);
- 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->iCol = (u16)iCol;
- continue;
- }
- if( sqlite3ExprIsInteger(pE, &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 ){
- resolveOutOfRangeError(pParse, zType, i+1, nResult);
- return 1;
- }
- pItem->iCol = (u16)iCol;
- continue;
- }
-
- /* Otherwise, treat the ORDER BY term as an ordinary expression */
- pItem->iCol = 0;
- if( sqlite3ResolveExprNames(pNC, pE) ){
- return 1;
- }
- }
- return sqlite3ResolveOrderGroupBy(pParse, pSelect, pOrderBy, zType);
-}
-
-/*
-** Resolve names in the SELECT statement p and all of its descendents.
-*/
-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;
- }
-
- /* Set up the local name-context to pass to sqlite3ResolveExprNames() to
- ** resolve the result-set expression list.
- */
- sNC.allowAgg = 1;
- 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;
- }
- }
-
- /* 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 ){
- const char *zSavedContext = pParse->zAuthContext;
- if( pItem->zName ) pParse->zAuthContext = pItem->zName;
- sqlite3ResolveSelectNames(pParse, pItem->pSelect, pOuterNC);
- pParse->zAuthContext = zSavedContext;
- if( pParse->nErr || db->mallocFailed ) 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.hasAgg ){
- p->selFlags |= SF_Aggregate;
- }else{
- sNC.allowAgg = 0;
- }
-
- /* 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 expression 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->pWhere) ||
- sqlite3ResolveExprNames(&sNC, p->pHaving)
- ){
- return WRC_Abort;
- }
-
- /* The ORDER BY and GROUP BY clauses may not refer to terms in
- ** outer queries
- */
- sNC.pNext = 0;
- sNC.allowAgg = 1;
-
- /* 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 pNC->hasAgg 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. */
-){
- int 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->hasAgg;
- pNC->hasAgg = 0;
- 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->hasAgg ){
- ExprSetProperty(pExpr, EP_Agg);
- }else if( savedHasAgg ){
- pNC->hasAgg = 1;
- }
- 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 );
- w.xExprCallback = resolveExprStep;
- w.xSelectCallback = resolveSelectStep;
- w.pParse = pParse;
- w.u.pNC = pOuterNC;
- sqlite3WalkSelect(&w, p);
-}
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