Add //third_party/sqlite to dirs_to_snapshot, remove net_sql.patch

third_party/sqlite/sqlite-src-3080704/src/update.c

Index: third_party/sqlite/sqlite-src-3080704/src/update.c
diff --git a/third_party/sqlite/sqlite-src-3080704/src/update.c b/third_party/sqlite/sqlite-src-3080704/src/update.c
new file mode 100644
index 0000000000000000000000000000000000000000..3af4017f1ba9a3143bbe2c9d0dd78b50aab3bd54
--- /dev/null
+++ b/third_party/sqlite/sqlite-src-3080704/src/update.c
@@ -0,0 +1,774 @@
+/*
+** 2001 September 15
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** This file contains C code routines that are called by the parser
+** to handle UPDATE statements.
+*/
+#include "sqliteInt.h"
+
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+/* Forward declaration */
+static void updateVirtualTable(
+  Parse *pParse,       /* The parsing context */
+  SrcList *pSrc,       /* The virtual table to be modified */
+  Table *pTab,         /* The virtual table */
+  ExprList *pChanges,  /* The columns to change in the UPDATE statement */
+  Expr *pRowidExpr,    /* Expression used to recompute the rowid */
+  int *aXRef,          /* Mapping from columns of pTab to entries in pChanges */
+  Expr *pWhere,        /* WHERE clause of the UPDATE statement */
+  int onError          /* ON CONFLICT strategy */
+);
+#endif /* SQLITE_OMIT_VIRTUALTABLE */
+
+/*
+** The most recently coded instruction was an OP_Column to retrieve the
+** i-th column of table pTab. This routine sets the P4 parameter of the 
+** OP_Column to the default value, if any.
+**
+** The default value of a column is specified by a DEFAULT clause in the 
+** column definition. This was either supplied by the user when the table
+** was created, or added later to the table definition by an ALTER TABLE
+** command. If the latter, then the row-records in the table btree on disk
+** may not contain a value for the column and the default value, taken
+** from the P4 parameter of the OP_Column instruction, is returned instead.
+** If the former, then all row-records are guaranteed to include a value
+** for the column and the P4 value is not required.
+**
+** Column definitions created by an ALTER TABLE command may only have 
+** literal default values specified: a number, null or a string. (If a more
+** complicated default expression value was provided, it is evaluated 
+** when the ALTER TABLE is executed and one of the literal values written
+** into the sqlite_master table.)
+**
+** Therefore, the P4 parameter is only required if the default value for
+** the column is a literal number, string or null. The sqlite3ValueFromExpr()
+** function is capable of transforming these types of expressions into
+** sqlite3_value objects.
+**
+** If parameter iReg is not negative, code an OP_RealAffinity instruction
+** on register iReg. This is used when an equivalent integer value is 
+** stored in place of an 8-byte floating point value in order to save 
+** space.
+*/
+void sqlite3ColumnDefault(Vdbe *v, Table *pTab, int i, int iReg){
+  assert( pTab!=0 );
+  if( !pTab->pSelect ){
+    sqlite3_value *pValue = 0;
+    u8 enc = ENC(sqlite3VdbeDb(v));
+    Column *pCol = &pTab->aCol[i];
+    VdbeComment((v, "%s.%s", pTab->zName, pCol->zName));
+    assert( i<pTab->nCol );
+    sqlite3ValueFromExpr(sqlite3VdbeDb(v), pCol->pDflt, enc, 
+                         pCol->affinity, &pValue);
+    if( pValue ){
+      sqlite3VdbeChangeP4(v, -1, (const char *)pValue, P4_MEM);
+    }
+#ifndef SQLITE_OMIT_FLOATING_POINT
+    if( pTab->aCol[i].affinity==SQLITE_AFF_REAL ){
+      sqlite3VdbeAddOp1(v, OP_RealAffinity, iReg);
+    }
+#endif
+  }
+}
+
+/*
+** Process an UPDATE statement.
+**
+**   UPDATE OR IGNORE table_wxyz SET a=b, c=d WHERE e<5 AND f NOT NULL;
+**          \_______/ \________/     \______/       \________________/
+*            onError   pTabList      pChanges             pWhere
+*/
+void sqlite3Update(
+  Parse *pParse,         /* The parser context */
+  SrcList *pTabList,     /* The table in which we should change things */
+  ExprList *pChanges,    /* Things to be changed */
+  Expr *pWhere,          /* The WHERE clause.  May be null */
+  int onError            /* How to handle constraint errors */
+){
+  int i, j;              /* Loop counters */
+  Table *pTab;           /* The table to be updated */
+  int addrTop = 0;       /* VDBE instruction address of the start of the loop */
+  WhereInfo *pWInfo;     /* Information about the WHERE clause */
+  Vdbe *v;               /* The virtual database engine */
+  Index *pIdx;           /* For looping over indices */
+  Index *pPk;            /* The PRIMARY KEY index for WITHOUT ROWID tables */
+  int nIdx;              /* Number of indices that need updating */
+  int iBaseCur;          /* Base cursor number */
+  int iDataCur;          /* Cursor for the canonical data btree */
+  int iIdxCur;           /* Cursor for the first index */
+  sqlite3 *db;           /* The database structure */
+  int *aRegIdx = 0;      /* One register assigned to each index to be updated */
+  int *aXRef = 0;        /* aXRef[i] is the index in pChanges->a[] of the
+                         ** an expression for the i-th column of the table.
+                         ** aXRef[i]==-1 if the i-th column is not changed. */
+  u8 *aToOpen;           /* 1 for tables and indices to be opened */
+  u8 chngPk;             /* PRIMARY KEY changed in a WITHOUT ROWID table */
+  u8 chngRowid;          /* Rowid changed in a normal table */
+  u8 chngKey;            /* Either chngPk or chngRowid */
+  Expr *pRowidExpr = 0;  /* Expression defining the new record number */
+  AuthContext sContext;  /* The authorization context */
+  NameContext sNC;       /* The name-context to resolve expressions in */
+  int iDb;               /* Database containing the table being updated */
+  int okOnePass;         /* True for one-pass algorithm without the FIFO */
+  int hasFK;             /* True if foreign key processing is required */
+  int labelBreak;        /* Jump here to break out of UPDATE loop */
+  int labelContinue;     /* Jump here to continue next step of UPDATE loop */
+
+#ifndef SQLITE_OMIT_TRIGGER
+  int isView;            /* True when updating a view (INSTEAD OF trigger) */
+  Trigger *pTrigger;     /* List of triggers on pTab, if required */
+  int tmask;             /* Mask of TRIGGER_BEFORE|TRIGGER_AFTER */
+#endif
+  int newmask;           /* Mask of NEW.* columns accessed by BEFORE triggers */
+  int iEph = 0;          /* Ephemeral table holding all primary key values */
+  int nKey = 0;          /* Number of elements in regKey for WITHOUT ROWID */
+  int aiCurOnePass[2];   /* The write cursors opened by WHERE_ONEPASS */
+
+  /* Register Allocations */
+  int regRowCount = 0;   /* A count of rows changed */
+  int regOldRowid;       /* The old rowid */
+  int regNewRowid;       /* The new rowid */
+  int regNew;            /* Content of the NEW.* table in triggers */
+  int regOld = 0;        /* Content of OLD.* table in triggers */
+  int regRowSet = 0;     /* Rowset of rows to be updated */
+  int regKey = 0;        /* composite PRIMARY KEY value */
+
+  memset(&sContext, 0, sizeof(sContext));
+  db = pParse->db;
+  if( pParse->nErr || db->mallocFailed ){
+    goto update_cleanup;
+  }
+  assert( pTabList->nSrc==1 );
+
+  /* Locate the table which we want to update. 
+  */
+  pTab = sqlite3SrcListLookup(pParse, pTabList);
+  if( pTab==0 ) goto update_cleanup;
+  iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema);
+
+  /* Figure out if we have any triggers and if the table being
+  ** updated is a view.
+  */
+#ifndef SQLITE_OMIT_TRIGGER
+  pTrigger = sqlite3TriggersExist(pParse, pTab, TK_UPDATE, pChanges, &tmask);
+  isView = pTab->pSelect!=0;
+  assert( pTrigger || tmask==0 );
+#else
+# define pTrigger 0
+# define isView 0
+# define tmask 0
+#endif
+#ifdef SQLITE_OMIT_VIEW
+# undef isView
+# define isView 0
+#endif
+
+  if( sqlite3ViewGetColumnNames(pParse, pTab) ){
+    goto update_cleanup;
+  }
+  if( sqlite3IsReadOnly(pParse, pTab, tmask) ){
+    goto update_cleanup;
+  }
+
+  /* Allocate a cursors for the main database table and for all indices.
+  ** The index cursors might not be used, but if they are used they
+  ** need to occur right after the database cursor.  So go ahead and
+  ** allocate enough space, just in case.
+  */
+  pTabList->a[0].iCursor = iBaseCur = iDataCur = pParse->nTab++;
+  iIdxCur = iDataCur+1;
+  pPk = HasRowid(pTab) ? 0 : sqlite3PrimaryKeyIndex(pTab);
+  for(nIdx=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, nIdx++){
+    if( IsPrimaryKeyIndex(pIdx) && pPk!=0 ){
+      iDataCur = pParse->nTab;
+      pTabList->a[0].iCursor = iDataCur;
+    }
+    pParse->nTab++;
+  }
+
+  /* Allocate space for aXRef[], aRegIdx[], and aToOpen[].  
+  ** Initialize aXRef[] and aToOpen[] to their default values.
+  */
+  aXRef = sqlite3DbMallocRaw(db, sizeof(int) * (pTab->nCol+nIdx) + nIdx+2 );
+  if( aXRef==0 ) goto update_cleanup;
+  aRegIdx = aXRef+pTab->nCol;
+  aToOpen = (u8*)(aRegIdx+nIdx);
+  memset(aToOpen, 1, nIdx+1);
+  aToOpen[nIdx+1] = 0;
+  for(i=0; i<pTab->nCol; i++) aXRef[i] = -1;
+
+  /* Initialize the name-context */
+  memset(&sNC, 0, sizeof(sNC));
+  sNC.pParse = pParse;
+  sNC.pSrcList = pTabList;
+
+  /* Resolve the column names in all the expressions of the
+  ** of the UPDATE statement.  Also find the column index
+  ** for each column to be updated in the pChanges array.  For each
+  ** column to be updated, make sure we have authorization to change
+  ** that column.
+  */
+  chngRowid = chngPk = 0;
+  for(i=0; i<pChanges->nExpr; i++){
+    if( sqlite3ResolveExprNames(&sNC, pChanges->a[i].pExpr) ){
+      goto update_cleanup;
+    }
+    for(j=0; j<pTab->nCol; j++){
+      if( sqlite3StrICmp(pTab->aCol[j].zName, pChanges->a[i].zName)==0 ){
+        if( j==pTab->iPKey ){
+          chngRowid = 1;
+          pRowidExpr = pChanges->a[i].pExpr;
+        }else if( pPk && (pTab->aCol[j].colFlags & COLFLAG_PRIMKEY)!=0 ){
+          chngPk = 1;
+        }
+        aXRef[j] = i;
+        break;
+      }
+    }
+    if( j>=pTab->nCol ){
+      if( pPk==0 && sqlite3IsRowid(pChanges->a[i].zName) ){
+        j = -1;
+        chngRowid = 1;
+        pRowidExpr = pChanges->a[i].pExpr;
+      }else{
+        sqlite3ErrorMsg(pParse, "no such column: %s", pChanges->a[i].zName);
+        pParse->checkSchema = 1;
+        goto update_cleanup;
+      }
+    }
+#ifndef SQLITE_OMIT_AUTHORIZATION
+    {
+      int rc;
+      rc = sqlite3AuthCheck(pParse, SQLITE_UPDATE, pTab->zName,
+                            j<0 ? "ROWID" : pTab->aCol[j].zName,
+                            db->aDb[iDb].zName);
+      if( rc==SQLITE_DENY ){
+        goto update_cleanup;
+      }else if( rc==SQLITE_IGNORE ){
+        aXRef[j] = -1;
+      }
+    }
+#endif
+  }
+  assert( (chngRowid & chngPk)==0 );
+  assert( chngRowid==0 || chngRowid==1 );
+  assert( chngPk==0 || chngPk==1 );
+  chngKey = chngRowid + chngPk;
+
+  /* The SET expressions are not actually used inside the WHERE loop.
+  ** So reset the colUsed mask
+  */
+  pTabList->a[0].colUsed = 0;
+
+  hasFK = sqlite3FkRequired(pParse, pTab, aXRef, chngKey);
+
+  /* There is one entry in the aRegIdx[] array for each index on the table
+  ** being updated.  Fill in aRegIdx[] with a register number that will hold
+  ** the key for accessing each index.  
+  */
+  for(j=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, j++){
+    int reg;
+    if( chngKey || hasFK || pIdx->pPartIdxWhere || pIdx==pPk ){
+      reg = ++pParse->nMem;
+    }else{
+      reg = 0;
+      for(i=0; i<pIdx->nKeyCol; i++){
+        if( aXRef[pIdx->aiColumn[i]]>=0 ){
+          reg = ++pParse->nMem;
+          break;
+        }
+      }
+    }
+    if( reg==0 ) aToOpen[j+1] = 0;
+    aRegIdx[j] = reg;
+  }
+
+  /* Begin generating code. */
+  v = sqlite3GetVdbe(pParse);
+  if( v==0 ) goto update_cleanup;
+  if( pParse->nested==0 ) sqlite3VdbeCountChanges(v);
+  sqlite3BeginWriteOperation(pParse, 1, iDb);
+
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+  /* Virtual tables must be handled separately */
+  if( IsVirtual(pTab) ){
+    updateVirtualTable(pParse, pTabList, pTab, pChanges, pRowidExpr, aXRef,
+                       pWhere, onError);
+    pWhere = 0;
+    pTabList = 0;
+    goto update_cleanup;
+  }
+#endif
+
+  /* Allocate required registers. */
+  regRowSet = ++pParse->nMem;
+  regOldRowid = regNewRowid = ++pParse->nMem;
+  if( chngPk || pTrigger || hasFK ){
+    regOld = pParse->nMem + 1;
+    pParse->nMem += pTab->nCol;
+  }
+  if( chngKey || pTrigger || hasFK ){
+    regNewRowid = ++pParse->nMem;
+  }
+  regNew = pParse->nMem + 1;
+  pParse->nMem += pTab->nCol;
+
+  /* Start the view context. */
+  if( isView ){
+    sqlite3AuthContextPush(pParse, &sContext, pTab->zName);
+  }
+
+  /* If we are trying to update a view, realize that view into
+  ** an ephemeral table.
+  */
+#if !defined(SQLITE_OMIT_VIEW) && !defined(SQLITE_OMIT_TRIGGER)
+  if( isView ){
+    sqlite3MaterializeView(pParse, pTab, pWhere, iDataCur);
+  }
+#endif
+
+  /* Resolve the column names in all the expressions in the
+  ** WHERE clause.
+  */
+  if( sqlite3ResolveExprNames(&sNC, pWhere) ){
+    goto update_cleanup;
+  }
+
+  /* Begin the database scan
+  */
+  if( HasRowid(pTab) ){
+    sqlite3VdbeAddOp3(v, OP_Null, 0, regRowSet, regOldRowid);
+    pWInfo = sqlite3WhereBegin(
+        pParse, pTabList, pWhere, 0, 0, WHERE_ONEPASS_DESIRED, iIdxCur
+    );
+    if( pWInfo==0 ) goto update_cleanup;
+    okOnePass = sqlite3WhereOkOnePass(pWInfo, aiCurOnePass);
+  
+    /* Remember the rowid of every item to be updated.
+    */
+    sqlite3VdbeAddOp2(v, OP_Rowid, iDataCur, regOldRowid);
+    if( !okOnePass ){
+      sqlite3VdbeAddOp2(v, OP_RowSetAdd, regRowSet, regOldRowid);
+    }
+  
+    /* End the database scan loop.
+    */
+    sqlite3WhereEnd(pWInfo);
+  }else{
+    int iPk;         /* First of nPk memory cells holding PRIMARY KEY value */
+    i16 nPk;         /* Number of components of the PRIMARY KEY */
+    int addrOpen;    /* Address of the OpenEphemeral instruction */
+
+    assert( pPk!=0 );
+    nPk = pPk->nKeyCol;
+    iPk = pParse->nMem+1;
+    pParse->nMem += nPk;
+    regKey = ++pParse->nMem;
+    iEph = pParse->nTab++;
+    sqlite3VdbeAddOp2(v, OP_Null, 0, iPk);
+    addrOpen = sqlite3VdbeAddOp2(v, OP_OpenEphemeral, iEph, nPk);
+    sqlite3VdbeSetP4KeyInfo(pParse, pPk);
+    pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, 0, 0, 
+                               WHERE_ONEPASS_DESIRED, iIdxCur);
+    if( pWInfo==0 ) goto update_cleanup;
+    okOnePass = sqlite3WhereOkOnePass(pWInfo, aiCurOnePass);
+    for(i=0; i<nPk; i++){
+      sqlite3ExprCodeGetColumnOfTable(v, pTab, iDataCur, pPk->aiColumn[i],
+                                      iPk+i);
+    }
+    if( okOnePass ){
+      sqlite3VdbeChangeToNoop(v, addrOpen);
+      nKey = nPk;
+      regKey = iPk;
+    }else{
+      sqlite3VdbeAddOp4(v, OP_MakeRecord, iPk, nPk, regKey,
+                        sqlite3IndexAffinityStr(v, pPk), nPk);
+      sqlite3VdbeAddOp2(v, OP_IdxInsert, iEph, regKey);
+    }
+    sqlite3WhereEnd(pWInfo);
+  }
+
+  /* Initialize the count of updated rows
+  */
+  if( (db->flags & SQLITE_CountRows) && !pParse->pTriggerTab ){
+    regRowCount = ++pParse->nMem;
+    sqlite3VdbeAddOp2(v, OP_Integer, 0, regRowCount);
+  }
+
+  labelBreak = sqlite3VdbeMakeLabel(v);
+  if( !isView ){
+    /* 
+    ** Open every index that needs updating.  Note that if any
+    ** index could potentially invoke a REPLACE conflict resolution 
+    ** action, then we need to open all indices because we might need
+    ** to be deleting some records.
+    */
+    if( onError==OE_Replace ){
+      memset(aToOpen, 1, nIdx+1);
+    }else{
+      for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
+        if( pIdx->onError==OE_Replace ){
+          memset(aToOpen, 1, nIdx+1);
+          break;
+        }
+      }
+    }
+    if( okOnePass ){
+      if( aiCurOnePass[0]>=0 ) aToOpen[aiCurOnePass[0]-iBaseCur] = 0;
+      if( aiCurOnePass[1]>=0 ) aToOpen[aiCurOnePass[1]-iBaseCur] = 0;
+    }
+    sqlite3OpenTableAndIndices(pParse, pTab, OP_OpenWrite, iBaseCur, aToOpen,
+                               0, 0);
+  }
+
+  /* Top of the update loop */
+  if( okOnePass ){
+    if( aToOpen[iDataCur-iBaseCur] && !isView ){
+      assert( pPk );
+      sqlite3VdbeAddOp4Int(v, OP_NotFound, iDataCur, labelBreak, regKey, nKey);
+      VdbeCoverageNeverTaken(v);
+    }
+    labelContinue = labelBreak;
+    sqlite3VdbeAddOp2(v, OP_IsNull, pPk ? regKey : regOldRowid, labelBreak);
+    VdbeCoverageIf(v, pPk==0);
+    VdbeCoverageIf(v, pPk!=0);
+  }else if( pPk ){
+    labelContinue = sqlite3VdbeMakeLabel(v);
+    sqlite3VdbeAddOp2(v, OP_Rewind, iEph, labelBreak); VdbeCoverage(v);
+    addrTop = sqlite3VdbeAddOp2(v, OP_RowKey, iEph, regKey);
+    sqlite3VdbeAddOp4Int(v, OP_NotFound, iDataCur, labelContinue, regKey, 0);
+    VdbeCoverage(v);
+  }else{
+    labelContinue = sqlite3VdbeAddOp3(v, OP_RowSetRead, regRowSet, labelBreak,
+                             regOldRowid);
+    VdbeCoverage(v);
+    sqlite3VdbeAddOp3(v, OP_NotExists, iDataCur, labelContinue, regOldRowid);
+    VdbeCoverage(v);
+  }
+
+  /* If the record number will change, set register regNewRowid to
+  ** contain the new value. If the record number is not being modified,
+  ** then regNewRowid is the same register as regOldRowid, which is
+  ** already populated.  */
+  assert( chngKey || pTrigger || hasFK || regOldRowid==regNewRowid );
+  if( chngRowid ){
+    sqlite3ExprCode(pParse, pRowidExpr, regNewRowid);
+    sqlite3VdbeAddOp1(v, OP_MustBeInt, regNewRowid); VdbeCoverage(v);
+  }
+
+  /* Compute the old pre-UPDATE content of the row being changed, if that
+  ** information is needed */
+  if( chngPk || hasFK || pTrigger ){
+    u32 oldmask = (hasFK ? sqlite3FkOldmask(pParse, pTab) : 0);
+    oldmask |= sqlite3TriggerColmask(pParse, 
+        pTrigger, pChanges, 0, TRIGGER_BEFORE|TRIGGER_AFTER, pTab, onError
+    );
+    for(i=0; i<pTab->nCol; i++){
+      if( oldmask==0xffffffff
+       || (i<32 && (oldmask & MASKBIT32(i))!=0)
+       || (pTab->aCol[i].colFlags & COLFLAG_PRIMKEY)!=0
+      ){
+        testcase(  oldmask!=0xffffffff && i==31 );
+        sqlite3ExprCodeGetColumnOfTable(v, pTab, iDataCur, i, regOld+i);
+      }else{
+        sqlite3VdbeAddOp2(v, OP_Null, 0, regOld+i);
+      }
+    }
+    if( chngRowid==0 && pPk==0 ){
+      sqlite3VdbeAddOp2(v, OP_Copy, regOldRowid, regNewRowid);
+    }
+  }
+
+  /* Populate the array of registers beginning at regNew with the new
+  ** row data. This array is used to check constants, create the new
+  ** table and index records, and as the values for any new.* references
+  ** made by triggers.
+  **
+  ** If there are one or more BEFORE triggers, then do not populate the
+  ** registers associated with columns that are (a) not modified by
+  ** this UPDATE statement and (b) not accessed by new.* references. The
+  ** values for registers not modified by the UPDATE must be reloaded from 
+  ** the database after the BEFORE triggers are fired anyway (as the trigger 
+  ** may have modified them). So not loading those that are not going to
+  ** be used eliminates some redundant opcodes.
+  */
+  newmask = sqlite3TriggerColmask(
+      pParse, pTrigger, pChanges, 1, TRIGGER_BEFORE, pTab, onError
+  );
+  /*sqlite3VdbeAddOp3(v, OP_Null, 0, regNew, regNew+pTab->nCol-1);*/
+  for(i=0; i<pTab->nCol; i++){
+    if( i==pTab->iPKey ){
+      sqlite3VdbeAddOp2(v, OP_Null, 0, regNew+i);
+    }else{
+      j = aXRef[i];
+      if( j>=0 ){
+        sqlite3ExprCode(pParse, pChanges->a[j].pExpr, regNew+i);
+      }else if( 0==(tmask&TRIGGER_BEFORE) || i>31 || (newmask & MASKBIT32(i)) ){
+        /* This branch loads the value of a column that will not be changed 
+        ** into a register. This is done if there are no BEFORE triggers, or
+        ** if there are one or more BEFORE triggers that use this value via
+        ** a new.* reference in a trigger program.
+        */
+        testcase( i==31 );
+        testcase( i==32 );
+        sqlite3ExprCodeGetColumnOfTable(v, pTab, iDataCur, i, regNew+i);
+      }else{
+        sqlite3VdbeAddOp2(v, OP_Null, 0, regNew+i);
+      }
+    }
+  }
+
+  /* Fire any BEFORE UPDATE triggers. This happens before constraints are
+  ** verified. One could argue that this is wrong.
+  */
+  if( tmask&TRIGGER_BEFORE ){
+    sqlite3TableAffinity(v, pTab, regNew);
+    sqlite3CodeRowTrigger(pParse, pTrigger, TK_UPDATE, pChanges, 
+        TRIGGER_BEFORE, pTab, regOldRowid, onError, labelContinue);
+
+    /* The row-trigger may have deleted the row being updated. In this
+    ** case, jump to the next row. No updates or AFTER triggers are 
+    ** required. This behavior - what happens when the row being updated
+    ** is deleted or renamed by a BEFORE trigger - is left undefined in the
+    ** documentation.
+    */
+    if( pPk ){
+      sqlite3VdbeAddOp4Int(v, OP_NotFound, iDataCur, labelContinue,regKey,nKey);
+      VdbeCoverage(v);
+    }else{
+      sqlite3VdbeAddOp3(v, OP_NotExists, iDataCur, labelContinue, regOldRowid);
+      VdbeCoverage(v);
+    }
+
+    /* If it did not delete it, the row-trigger may still have modified 
+    ** some of the columns of the row being updated. Load the values for 
+    ** all columns not modified by the update statement into their 
+    ** registers in case this has happened.
+    */
+    for(i=0; i<pTab->nCol; i++){
+      if( aXRef[i]<0 && i!=pTab->iPKey ){
+        sqlite3ExprCodeGetColumnOfTable(v, pTab, iDataCur, i, regNew+i);
+      }
+    }
+  }
+
+  if( !isView ){
+    int j1 = 0;           /* Address of jump instruction */
+    int bReplace = 0;     /* True if REPLACE conflict resolution might happen */
+
+    /* Do constraint checks. */
+    assert( regOldRowid>0 );
+    sqlite3GenerateConstraintChecks(pParse, pTab, aRegIdx, iDataCur, iIdxCur,
+        regNewRowid, regOldRowid, chngKey, onError, labelContinue, &bReplace);
+
+    /* Do FK constraint checks. */
+    if( hasFK ){
+      sqlite3FkCheck(pParse, pTab, regOldRowid, 0, aXRef, chngKey);
+    }
+
+    /* Delete the index entries associated with the current record.  */
+    if( bReplace || chngKey ){
+      if( pPk ){
+        j1 = sqlite3VdbeAddOp4Int(v, OP_NotFound, iDataCur, 0, regKey, nKey);
+      }else{
+        j1 = sqlite3VdbeAddOp3(v, OP_NotExists, iDataCur, 0, regOldRowid);
+      }
+      VdbeCoverageNeverTaken(v);
+    }
+    sqlite3GenerateRowIndexDelete(pParse, pTab, iDataCur, iIdxCur, aRegIdx);
+  
+    /* If changing the record number, delete the old record.  */
+    if( hasFK || chngKey || pPk!=0 ){
+      sqlite3VdbeAddOp2(v, OP_Delete, iDataCur, 0);
+    }
+    if( bReplace || chngKey ){
+      sqlite3VdbeJumpHere(v, j1);
+    }
+
+    if( hasFK ){
+      sqlite3FkCheck(pParse, pTab, 0, regNewRowid, aXRef, chngKey);
+    }
+  
+    /* Insert the new index entries and the new record. */
+    sqlite3CompleteInsertion(pParse, pTab, iDataCur, iIdxCur,
+                             regNewRowid, aRegIdx, 1, 0, 0);
+
+    /* Do any ON CASCADE, SET NULL or SET DEFAULT operations required to
+    ** handle rows (possibly in other tables) that refer via a foreign key
+    ** to the row just updated. */ 
+    if( hasFK ){
+      sqlite3FkActions(pParse, pTab, pChanges, regOldRowid, aXRef, chngKey);
+    }
+  }
+
+  /* Increment the row counter 
+  */
+  if( (db->flags & SQLITE_CountRows) && !pParse->pTriggerTab){
+    sqlite3VdbeAddOp2(v, OP_AddImm, regRowCount, 1);
+  }
+
+  sqlite3CodeRowTrigger(pParse, pTrigger, TK_UPDATE, pChanges, 
+      TRIGGER_AFTER, pTab, regOldRowid, onError, labelContinue);
+
+  /* Repeat the above with the next record to be updated, until
+  ** all record selected by the WHERE clause have been updated.
+  */
+  if( okOnePass ){
+    /* Nothing to do at end-of-loop for a single-pass */
+  }else if( pPk ){
+    sqlite3VdbeResolveLabel(v, labelContinue);
+    sqlite3VdbeAddOp2(v, OP_Next, iEph, addrTop); VdbeCoverage(v);
+  }else{
+    sqlite3VdbeAddOp2(v, OP_Goto, 0, labelContinue);
+  }
+  sqlite3VdbeResolveLabel(v, labelBreak);
+
+  /* Close all tables */
+  for(i=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, i++){
+    assert( aRegIdx );
+    if( aToOpen[i+1] ){
+      sqlite3VdbeAddOp2(v, OP_Close, iIdxCur+i, 0);
+    }
+  }
+  if( iDataCur<iIdxCur ) sqlite3VdbeAddOp2(v, OP_Close, iDataCur, 0);
+
+  /* Update the sqlite_sequence table by storing the content of the
+  ** maximum rowid counter values recorded while inserting into
+  ** autoincrement tables.
+  */
+  if( pParse->nested==0 && pParse->pTriggerTab==0 ){
+    sqlite3AutoincrementEnd(pParse);
+  }
+
+  /*
+  ** Return the number of rows that were changed. If this routine is 
+  ** generating code because of a call to sqlite3NestedParse(), do not
+  ** invoke the callback function.
+  */
+  if( (db->flags&SQLITE_CountRows) && !pParse->pTriggerTab && !pParse->nested ){
+    sqlite3VdbeAddOp2(v, OP_ResultRow, regRowCount, 1);
+    sqlite3VdbeSetNumCols(v, 1);
+    sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "rows updated", SQLITE_STATIC);
+  }
+
+update_cleanup:
+  sqlite3AuthContextPop(&sContext);
+  sqlite3DbFree(db, aXRef); /* Also frees aRegIdx[] and aToOpen[] */
+  sqlite3SrcListDelete(db, pTabList);
+  sqlite3ExprListDelete(db, pChanges);
+  sqlite3ExprDelete(db, pWhere);
+  return;
+}
+/* Make sure "isView" and other macros defined above are undefined. Otherwise
+** they may interfere with compilation of other functions in this file
+** (or in another file, if this file becomes part of the amalgamation).  */
+#ifdef isView
+ #undef isView
+#endif
+#ifdef pTrigger
+ #undef pTrigger
+#endif
+
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+/*
+** Generate code for an UPDATE of a virtual table.
+**
+** The strategy is that we create an ephemeral table that contains
+** for each row to be changed:
+**
+**   (A)  The original rowid of that row.
+**   (B)  The revised rowid for the row. (note1)
+**   (C)  The content of every column in the row.
+**
+** Then we loop over this ephemeral table and for each row in
+** the ephemeral table call VUpdate.
+**
+** When finished, drop the ephemeral table.
+**
+** (note1) Actually, if we know in advance that (A) is always the same
+** as (B) we only store (A), then duplicate (A) when pulling
+** it out of the ephemeral table before calling VUpdate.
+*/
+static void updateVirtualTable(
+  Parse *pParse,       /* The parsing context */
+  SrcList *pSrc,       /* The virtual table to be modified */
+  Table *pTab,         /* The virtual table */
+  ExprList *pChanges,  /* The columns to change in the UPDATE statement */
+  Expr *pRowid,        /* Expression used to recompute the rowid */
+  int *aXRef,          /* Mapping from columns of pTab to entries in pChanges */
+  Expr *pWhere,        /* WHERE clause of the UPDATE statement */
+  int onError          /* ON CONFLICT strategy */
+){
+  Vdbe *v = pParse->pVdbe;  /* Virtual machine under construction */
+  ExprList *pEList = 0;     /* The result set of the SELECT statement */
+  Select *pSelect = 0;      /* The SELECT statement */
+  Expr *pExpr;              /* Temporary expression */
+  int ephemTab;             /* Table holding the result of the SELECT */
+  int i;                    /* Loop counter */
+  int addr;                 /* Address of top of loop */
+  int iReg;                 /* First register in set passed to OP_VUpdate */
+  sqlite3 *db = pParse->db; /* Database connection */
+  const char *pVTab = (const char*)sqlite3GetVTable(db, pTab);
+  SelectDest dest;
+
+  /* Construct the SELECT statement that will find the new values for
+  ** all updated rows. 
+  */
+  pEList = sqlite3ExprListAppend(pParse, 0, sqlite3Expr(db, TK_ID, "_rowid_"));
+  if( pRowid ){
+    pEList = sqlite3ExprListAppend(pParse, pEList,
+                                   sqlite3ExprDup(db, pRowid, 0));
+  }
+  assert( pTab->iPKey<0 );
+  for(i=0; i<pTab->nCol; i++){
+    if( aXRef[i]>=0 ){
+      pExpr = sqlite3ExprDup(db, pChanges->a[aXRef[i]].pExpr, 0);
+    }else{
+      pExpr = sqlite3Expr(db, TK_ID, pTab->aCol[i].zName);
+    }
+    pEList = sqlite3ExprListAppend(pParse, pEList, pExpr);
+  }
+  pSelect = sqlite3SelectNew(pParse, pEList, pSrc, pWhere, 0, 0, 0, 0, 0, 0);
+  
+  /* Create the ephemeral table into which the update results will
+  ** be stored.
+  */
+  assert( v );
+  ephemTab = pParse->nTab++;
+  sqlite3VdbeAddOp2(v, OP_OpenEphemeral, ephemTab, pTab->nCol+1+(pRowid!=0));
+  sqlite3VdbeChangeP5(v, BTREE_UNORDERED);
+
+  /* fill the ephemeral table 
+  */
+  sqlite3SelectDestInit(&dest, SRT_Table, ephemTab);
+  sqlite3Select(pParse, pSelect, &dest);
+
+  /* Generate code to scan the ephemeral table and call VUpdate. */
+  iReg = ++pParse->nMem;
+  pParse->nMem += pTab->nCol+1;
+  addr = sqlite3VdbeAddOp2(v, OP_Rewind, ephemTab, 0); VdbeCoverage(v);
+  sqlite3VdbeAddOp3(v, OP_Column,  ephemTab, 0, iReg);
+  sqlite3VdbeAddOp3(v, OP_Column, ephemTab, (pRowid?1:0), iReg+1);
+  for(i=0; i<pTab->nCol; i++){
+    sqlite3VdbeAddOp3(v, OP_Column, ephemTab, i+1+(pRowid!=0), iReg+2+i);
+  }
+  sqlite3VtabMakeWritable(pParse, pTab);
+  sqlite3VdbeAddOp4(v, OP_VUpdate, 0, pTab->nCol+2, iReg, pVTab, P4_VTAB);
+  sqlite3VdbeChangeP5(v, onError==OE_Default ? OE_Abort : onError);
+  sqlite3MayAbort(pParse);
+  sqlite3VdbeAddOp2(v, OP_Next, ephemTab, addr+1); VdbeCoverage(v);
+  sqlite3VdbeJumpHere(v, addr);
+  sqlite3VdbeAddOp2(v, OP_Close, ephemTab, 0);
+
+  /* Cleanup */
+  sqlite3SelectDelete(db, pSelect);  
+}
+#endif /* SQLITE_OMIT_VIRTUALTABLE */