Refactor names of column index transformation functions, for clarity.
Get generated columns working with ALTER TABLE RENAME COLUMN.

FossilOrigin-Name: 27ab41c9102e7801ff829488fc123a8040da008bef373d6704efbe2f93e1da90
diff --git a/src/alter.c b/src/alter.c
index f8cada0..b7389bf 100644
--- a/src/alter.c
+++ b/src/alter.c
@@ -1334,6 +1334,11 @@
           sqlite3WalkExprList(&sWalker, pIdx->aColExpr);
         }
       }
+#ifndef SQLITE_OMIT_GENERATED_COLUMNS
+      for(i=0; i<sParse.pNewTable->nCol; i++){
+        sqlite3WalkExpr(&sWalker, sParse.pNewTable->aCol[i].pDflt);
+      }
+#endif
 
       for(pFKey=sParse.pNewTable->pFKey; pFKey; pFKey=pFKey->pNextFrom){
         for(i=0; i<pFKey->nCol; i++){
diff --git a/src/analyze.c b/src/analyze.c
index 8f73853..6df6e7a 100644
--- a/src/analyze.c
+++ b/src/analyze.c
@@ -1182,7 +1182,7 @@
       int j, k, regKey;
       regKey = sqlite3GetTempRange(pParse, pPk->nKeyCol);
       for(j=0; j<pPk->nKeyCol; j++){
-        k = sqlite3ColumnOfIndex(pIdx, pPk->aiColumn[j]);
+        k = sqlite3TableColumnToIndex(pIdx, pPk->aiColumn[j]);
         assert( k>=0 && k<pIdx->nColumn );
         sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, k, regKey+j);
         VdbeComment((v, "%s", pTab->aCol[pPk->aiColumn[j]].zName));
diff --git a/src/build.c b/src/build.c
index f00dc32..48f3a1c 100644
--- a/src/build.c
+++ b/src/build.c
@@ -877,10 +877,12 @@
 }
 
 /*
-** Return the true column number of index pIdx that corresponds to table
-** true column iCol.  Return -1 if not found.
+** Convert an table column number into a index column number.  That is,
+** for the column iCol in the table (as defined by the CREATE TABLE statement)
+** find the (first) offset of that column in index pIdx.  Or return -1
+** if column iCol is not used in index pIdx.
 */
-i16 sqlite3ColumnOfIndex(Index *pIdx, i16 iCol){
+i16 sqlite3TableColumnToIndex(Index *pIdx, i16 iCol){
   int i;
   for(i=0; i<pIdx->nColumn; i++){
     if( iCol==pIdx->aiColumn[i] ) return i;
@@ -889,20 +891,20 @@
 }
 
 #ifndef SQLITE_OMIT_GENERATED_COLUMNS
-/* Convert a storage column number into a true column number.
+/* Convert a storage column number into a table column number.
 **
 ** The storage column number (0,1,2,....) is the index of the value
 ** as it appears in the record on disk.  The true column number
 ** is the index (0,1,2,...) of the column in the CREATE TABLE statement.
 **
-** The storage column number is less than the true column number if
-** and only there are virtual columns to the left.
+** The storage column number is less than the table column number if
+** and only there are VIRTUAL columns to the left.
 **
 ** If SQLITE_OMIT_GENERATED_COLUMNS, this routine is a no-op macro.
 **
-** This function is the inverse of sqlite3ColumnOfTable().
+** This function is the inverse of sqlite3TableColumnToStorage().
 */
-i16 sqlite3ColumnOfStorage(Table *pTab, i16 iCol){
+i16 sqlite3StorageColumnToTable(Table *pTab, i16 iCol){
   if( pTab->tabFlags & TF_HasVirtual ){
     int i;
     for(i=0; i<=iCol; i++){
@@ -914,7 +916,7 @@
 #endif
 
 #ifndef SQLITE_OMIT_GENERATED_COLUMNS
-/* Convert a true column number into a storage column number.
+/* Convert a table column number into a storage column number.
 **
 ** The storage column number (0,1,2,....) is the index of the value
 ** as it appears in the record on disk.  The true column number
@@ -922,9 +924,9 @@
 **
 ** If SQLITE_OMIT_GENERATED_COLUMNS, this routine is a no-op macro.
 **
-** This function is the inverse of sqlite3ColumnOfStorage().
+** This function is the inverse of sqlite3StorageColumnToTable().
 */
-i16 sqlite3ColumnOfTable(Table *pTab, i16 iCol){
+i16 sqlite3TableColumnToStorage(Table *pTab, i16 iCol){
   int i;
   i16 n;
   assert( iCol<pTab->nCol );
@@ -1577,11 +1579,12 @@
   u8 eType = COLFLAG_VIRTUAL;
   Table *pTab = pParse->pNewTable;
   Column *pCol;
-  if( IN_RENAME_OBJECT ){
-    sqlite3RenameExprUnmap(pParse, pExpr);
-  }
   if( pTab==0 ) goto generated_done;
   pCol = &(pTab->aCol[pTab->nCol-1]);
+  if( IN_DECLARE_VTAB ){
+    sqlite3ErrorMsg(pParse, "virtual tables cannot use computed columns");
+    goto generated_done;
+  }
   if( pCol->pDflt ) goto generated_error;
   if( pType ){
     if( pType->n==7 && sqlite3StrNICmp("virtual",pType->z,7)==0 ){
@@ -1597,7 +1600,8 @@
   assert( TF_HasVirtual==COLFLAG_VIRTUAL );
   assert( TF_HasStored==COLFLAG_STORED );
   pTab->tabFlags |= eType;
-  pCol->pDflt = sqlite3ExprDup(pParse->db, pExpr, 0);
+  pCol->pDflt = pExpr;
+  pExpr = 0;
   goto generated_done;
 
 generated_error:
@@ -3651,13 +3655,13 @@
   /* If this index contains every column of its table, then mark
   ** it as a covering index */
   assert( HasRowid(pTab) 
-      || pTab->iPKey<0 || sqlite3ColumnOfIndex(pIndex, pTab->iPKey)>=0 );
+      || pTab->iPKey<0 || sqlite3TableColumnToIndex(pIndex, pTab->iPKey)>=0 );
   recomputeColumnsNotIndexed(pIndex);
   if( pTblName!=0 && pIndex->nColumn>=pTab->nCol ){
     pIndex->isCovering = 1;
     for(j=0; j<pTab->nCol; j++){
       if( j==pTab->iPKey ) continue;
-      if( sqlite3ColumnOfIndex(pIndex,j)>=0 ) continue;
+      if( sqlite3TableColumnToIndex(pIndex,j)>=0 ) continue;
       pIndex->isCovering = 0;
       break;
     }
diff --git a/src/expr.c b/src/expr.c
index 41ffe71..c57a000 100644
--- a/src/expr.c
+++ b/src/expr.c
@@ -3410,10 +3410,10 @@
       return;
 #endif
     }else if( !HasRowid(pTab) ){
-      x = sqlite3ColumnOfIndex(sqlite3PrimaryKeyIndex(pTab), iCol);
+      x = sqlite3TableColumnToIndex(sqlite3PrimaryKeyIndex(pTab), iCol);
       op = OP_Column;
     }else{
-      x = sqlite3ColumnOfTable(pTab,iCol);
+      x = sqlite3TableColumnToStorage(pTab,iCol);
       op = OP_Column;
     }
     sqlite3VdbeAddOp3(v, op, iTabCur, x, regOut);
@@ -3591,7 +3591,8 @@
             return -1-pParse->iSelfTab;
           }
           pCol = pTab->aCol + pExpr->iColumn;
-          iSrc = sqlite3ColumnOfTable(pTab, pExpr->iColumn) - pParse->iSelfTab;
+          iSrc = sqlite3TableColumnToStorage(pTab, pExpr->iColumn)
+                      - pParse->iSelfTab;
 #ifndef SQLITE_OMIT_GENERATED_COLUMNS
           if( pCol->colFlags & COLFLAG_GENERATED ){
             if( pCol->colFlags & COLFLAG_BUSY ){
@@ -5320,7 +5321,7 @@
 static int exprIdxCover(Walker *pWalker, Expr *pExpr){
   if( pExpr->op==TK_COLUMN
    && pExpr->iTable==pWalker->u.pIdxCover->iCur
-   && sqlite3ColumnOfIndex(pWalker->u.pIdxCover->pIdx, pExpr->iColumn)<0
+   && sqlite3TableColumnToIndex(pWalker->u.pIdxCover->pIdx, pExpr->iColumn)<0
   ){
     pWalker->eCode = 1;
     return WRC_Abort;
diff --git a/src/insert.c b/src/insert.c
index fe275d5..88b8e6a 100644
--- a/src/insert.c
+++ b/src/insert.c
@@ -1055,7 +1055,7 @@
       int k;
       u32 colFlags;
       assert( i>=nHidden );
-      assert( iRegStore==sqlite3ColumnOfTable(pTab,i)+regRowid+1 );
+      assert( iRegStore==sqlite3TableColumnToStorage(pTab,i)+regRowid+1 );
       if( i==pTab->iPKey ){
         /* The value of the INTEGER PRIMARY KEY column is always a NULL.
         ** Whenever this column is read, the rowid will be substituted
@@ -1464,7 +1464,7 @@
       pParse->iSelfTab = 0;
       if( onError==OE_Replace ) onError = OE_Abort;
     }else{
-      iReg = sqlite3ColumnOfTable(pTab, i) + regNewData + 1;
+      iReg = sqlite3TableColumnToStorage(pTab, i) + regNewData + 1;
     }
     switch( onError ){
       case OE_Replace: {
@@ -1782,7 +1782,7 @@
         VdbeComment((v, "%s column %d", pIdx->zName, i));
 #endif
       }else{
-        x = sqlite3ColumnOfTable(pTab, iField) + regNewData + 1;
+        x = sqlite3TableColumnToStorage(pTab, iField) + regNewData + 1;
         sqlite3VdbeAddOp2(v, OP_SCopy, x, regIdx+i);
         VdbeComment((v, "%s", pTab->aCol[iField].zName));
       }
@@ -1873,7 +1873,7 @@
         if( pIdx!=pPk ){
           for(i=0; i<pPk->nKeyCol; i++){
             assert( pPk->aiColumn[i]>=0 );
-            x = sqlite3ColumnOfIndex(pIdx, pPk->aiColumn[i]);
+            x = sqlite3TableColumnToIndex(pIdx, pPk->aiColumn[i]);
             sqlite3VdbeAddOp3(v, OP_Column, iThisCur, x, regR+i);
             VdbeComment((v, "%s.%s", pTab->zName,
                          pTab->aCol[pPk->aiColumn[i]].zName));
diff --git a/src/sqliteInt.h b/src/sqliteInt.h
index a1e6e17..10b2eea 100644
--- a/src/sqliteInt.h
+++ b/src/sqliteInt.h
@@ -1818,8 +1818,21 @@
 };
 
 /*
-** information about each column of an SQL table is held in an instance
-** of this structure.
+** Information about each column of an SQL table is held in an instance
+** of the Column structure, in the Table.aCol[] array.
+**
+** Definitions:
+**
+**   "table column index"     This is the index of the column in the
+**                            Table.aCol[] array, and also the index of
+**                            the column in the original CREATE TABLE stmt.
+**
+**   "storage column index"   This is the index of the column in the
+**                            record BLOB generated by the OP_MakeRecord
+**                            opcode.  The storage column index is less than
+**                            or equal to the table column index.  It is
+**                            equal if and only if there are no VIRTUAL
+**                            columns to the left.
 */
 struct Column {
   char *zName;     /* Name of this column, \000, then the type */
@@ -3952,13 +3965,13 @@
 Table *sqlite3ResultSetOfSelect(Parse*,Select*,char);
 void sqlite3OpenMasterTable(Parse *, int);
 Index *sqlite3PrimaryKeyIndex(Table*);
-i16 sqlite3ColumnOfIndex(Index*, i16);
+i16 sqlite3TableColumnToIndex(Index*, i16);
 #ifdef SQLITE_OMIT_GENERATED_COLUMNS
-# define sqlite3ColumnOfTable(T,X)   (X)  /* No-op pass-through */
-# define sqlite3ColumnOfStorage(T,X) (X)  /* No-op pass-through */
+# define sqlite3TableColumnToStorage(T,X) (X)  /* No-op pass-through */
+# define sqlite3StorageColumnToTable(T,X) (X)  /* No-op pass-through */
 #else
-  i16 sqlite3ColumnOfTable(Table*, i16);
-  i16 sqlite3ColumnOfStorage(Table*, i16);
+  i16 sqlite3TableColumnToStorage(Table*, i16);
+  i16 sqlite3StorageColumnToTable(Table*, i16);
 #endif
 void sqlite3StartTable(Parse*,Token*,Token*,int,int,int,int);
 #if SQLITE_ENABLE_HIDDEN_COLUMNS
diff --git a/src/upsert.c b/src/upsert.c
index 7beb9ff..5db4f5f 100644
--- a/src/upsert.c
+++ b/src/upsert.c
@@ -226,7 +226,7 @@
       for(i=0; i<nPk; i++){
         int k;
         assert( pPk->aiColumn[i]>=0 );
-        k = sqlite3ColumnOfIndex(pIdx, pPk->aiColumn[i]);
+        k = sqlite3TableColumnToIndex(pIdx, pPk->aiColumn[i]);
         sqlite3VdbeAddOp3(v, OP_Column, iCur, k, iPk+i);
         VdbeComment((v, "%s.%s", pIdx->zName,
                     pTab->aCol[pPk->aiColumn[i]].zName));
diff --git a/src/vdbeapi.c b/src/vdbeapi.c
index c7968ee..074d458 100644
--- a/src/vdbeapi.c
+++ b/src/vdbeapi.c
@@ -1831,7 +1831,7 @@
     goto preupdate_old_out;
   }
   if( p->pPk ){
-    iIdx = sqlite3ColumnOfIndex(p->pPk, iIdx);
+    iIdx = sqlite3TableColumnToIndex(p->pPk, iIdx);
   }
   if( iIdx>=p->pCsr->nField || iIdx<0 ){
     rc = SQLITE_RANGE;
@@ -1921,7 +1921,7 @@
     goto preupdate_new_out;
   }
   if( p->pPk && p->op!=SQLITE_UPDATE ){
-    iIdx = sqlite3ColumnOfIndex(p->pPk, iIdx);
+    iIdx = sqlite3TableColumnToIndex(p->pPk, iIdx);
   }
   if( iIdx>=p->pCsr->nField || iIdx<0 ){
     rc = SQLITE_RANGE;
diff --git a/src/where.c b/src/where.c
index 252e906..ec2d384 100644
--- a/src/where.c
+++ b/src/where.c
@@ -5379,9 +5379,9 @@
             x = pPk->aiColumn[x];
             assert( x>=0 );
           }else{
-            x = sqlite3ColumnOfStorage(pTab,x);
+            x = sqlite3StorageColumnToTable(pTab,x);
           }
-          x = sqlite3ColumnOfIndex(pIdx, x);
+          x = sqlite3TableColumnToIndex(pIdx, x);
           if( x>=0 ){
             pOp->p2 = x;
             pOp->p1 = pLevel->iIdxCur;
diff --git a/src/wherecode.c b/src/wherecode.c
index af395a3..686a8d6 100644
--- a/src/wherecode.c
+++ b/src/wherecode.c
@@ -823,7 +823,7 @@
   assert( pHint->pIdx!=0 );
   if( pExpr->op==TK_COLUMN
    && pExpr->iTable==pHint->iTabCur
-   && sqlite3ColumnOfIndex(pHint->pIdx, pExpr->iColumn)<0
+   && sqlite3TableColumnToIndex(pHint->pIdx, pExpr->iColumn)<0
   ){
     pWalker->eCode = 1;
   }
@@ -891,7 +891,7 @@
       pExpr->iTable = reg;
     }else if( pHint->pIdx!=0 ){
       pExpr->iTable = pHint->iIdxCur;
-      pExpr->iColumn = sqlite3ColumnOfIndex(pHint->pIdx, pExpr->iColumn);
+      pExpr->iColumn = sqlite3TableColumnToIndex(pHint->pIdx, pExpr->iColumn);
       assert( pExpr->iColumn>=0 );
     }
   }else if( pExpr->op==TK_AGG_FUNCTION ){
@@ -1826,7 +1826,7 @@
       Index *pPk = sqlite3PrimaryKeyIndex(pIdx->pTable);
       iRowidReg = sqlite3GetTempRange(pParse, pPk->nKeyCol);
       for(j=0; j<pPk->nKeyCol; j++){
-        k = sqlite3ColumnOfIndex(pIdx, pPk->aiColumn[j]);
+        k = sqlite3TableColumnToIndex(pIdx, pPk->aiColumn[j]);
         sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, k, iRowidReg+j);
       }
       sqlite3VdbeAddOp4Int(v, OP_NotFound, iCur, addrCont,