Adding upstream version 3.45.1.upstream/3.45.1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1079 insertions, 0 deletions

diff --git a/src/prepare.c b/src/prepare.c
new file mode 100644
index 0000000..87569ee
--- /dev/null
+++ b/src/prepare.c
@@ -0,0 +1,1079 @@
+/*
+** 2005 May 25
+**
+** 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 the implementation of the sqlite3_prepare()
+** interface, and routines that contribute to loading the database schema
+** from disk.
+*/
+#include "sqliteInt.h"
+
+/*
+** Fill the InitData structure with an error message that indicates
+** that the database is corrupt.
+*/
+static void corruptSchema(
+  InitData *pData,     /* Initialization context */
+  char **azObj,        /* Type and name of object being parsed */
+  const char *zExtra   /* Error information */
+){
+  sqlite3 *db = pData->db;
+  if( db->mallocFailed ){
+    pData->rc = SQLITE_NOMEM_BKPT;
+  }else if( pData->pzErrMsg[0]!=0 ){
+    /* A error message has already been generated.  Do not overwrite it */
+  }else if( pData->mInitFlags & (INITFLAG_AlterMask) ){
+    static const char *azAlterType[] = {
+       "rename",
+       "drop column",
+       "add column"
+    };
+    *pData->pzErrMsg = sqlite3MPrintf(db, 
+        "error in %s %s after %s: %s", azObj[0], azObj[1], 
+        azAlterType[(pData->mInitFlags&INITFLAG_AlterMask)-1], 
+        zExtra
+    );
+    pData->rc = SQLITE_ERROR;
+  }else if( db->flags & SQLITE_WriteSchema ){
+    pData->rc = SQLITE_CORRUPT_BKPT;
+  }else{
+    char *z;
+    const char *zObj = azObj[1] ? azObj[1] : "?";
+    z = sqlite3MPrintf(db, "malformed database schema (%s)", zObj);
+    if( zExtra && zExtra[0] ) z = sqlite3MPrintf(db, "%z - %s", z, zExtra);
+    *pData->pzErrMsg = z;
+    pData->rc = SQLITE_CORRUPT_BKPT;
+  }
+}
+
+/*
+** Check to see if any sibling index (another index on the same table)
+** of pIndex has the same root page number, and if it does, return true.
+** This would indicate a corrupt schema.
+*/
+int sqlite3IndexHasDuplicateRootPage(Index *pIndex){
+  Index *p;
+  for(p=pIndex->pTable->pIndex; p; p=p->pNext){
+    if( p->tnum==pIndex->tnum && p!=pIndex ) return 1;
+  }
+  return 0;
+}
+
+/* forward declaration */
+static int sqlite3Prepare(
+  sqlite3 *db,              /* Database handle. */
+  const char *zSql,         /* UTF-8 encoded SQL statement. */
+  int nBytes,               /* Length of zSql in bytes. */
+  u32 prepFlags,            /* Zero or more SQLITE_PREPARE_* flags */
+  Vdbe *pReprepare,         /* VM being reprepared */
+  sqlite3_stmt **ppStmt,    /* OUT: A pointer to the prepared statement */
+  const char **pzTail       /* OUT: End of parsed string */
+);
+
+
+/*
+** This is the callback routine for the code that initializes the
+** database.  See sqlite3Init() below for additional information.
+** This routine is also called from the OP_ParseSchema opcode of the VDBE.
+**
+** Each callback contains the following information:
+**
+**     argv[0] = type of object: "table", "index", "trigger", or "view".
+**     argv[1] = name of thing being created
+**     argv[2] = associated table if an index or trigger
+**     argv[3] = root page number for table or index. 0 for trigger or view.
+**     argv[4] = SQL text for the CREATE statement.
+**
+*/
+int sqlite3InitCallback(void *pInit, int argc, char **argv, char **NotUsed){
+  InitData *pData = (InitData*)pInit;
+  sqlite3 *db = pData->db;
+  int iDb = pData->iDb;
+
+  assert( argc==5 );
+  UNUSED_PARAMETER2(NotUsed, argc);
+  assert( sqlite3_mutex_held(db->mutex) );
+  db->mDbFlags |= DBFLAG_EncodingFixed;
+  if( argv==0 ) return 0;   /* Might happen if EMPTY_RESULT_CALLBACKS are on */
+  pData->nInitRow++;
+  if( db->mallocFailed ){
+    corruptSchema(pData, argv, 0);
+    return 1;
+  }
+
+  assert( iDb>=0 && iDb<db->nDb );
+  if( argv[3]==0 ){
+    corruptSchema(pData, argv, 0);
+  }else if( argv[4]
+         && 'c'==sqlite3UpperToLower[(unsigned char)argv[4][0]]
+         && 'r'==sqlite3UpperToLower[(unsigned char)argv[4][1]] ){
+    /* Call the parser to process a CREATE TABLE, INDEX or VIEW.
+    ** But because db->init.busy is set to 1, no VDBE code is generated
+    ** or executed.  All the parser does is build the internal data
+    ** structures that describe the table, index, or view.
+    **
+    ** No other valid SQL statement, other than the variable CREATE statements,
+    ** can begin with the letters "C" and "R".  Thus, it is not possible run
+    ** any other kind of statement while parsing the schema, even a corrupt
+    ** schema.
+    */
+    int rc;
+    u8 saved_iDb = db->init.iDb;
+    sqlite3_stmt *pStmt;
+    TESTONLY(int rcp);            /* Return code from sqlite3_prepare() */
+
+    assert( db->init.busy );
+    db->init.iDb = iDb;
+    if( sqlite3GetUInt32(argv[3], &db->init.newTnum)==0
+     || (db->init.newTnum>pData->mxPage && pData->mxPage>0)
+    ){
+      if( sqlite3Config.bExtraSchemaChecks ){
+        corruptSchema(pData, argv, "invalid rootpage");
+      }
+    }
+    db->init.orphanTrigger = 0;
+    db->init.azInit = (const char**)argv;
+    pStmt = 0;
+    TESTONLY(rcp = ) sqlite3Prepare(db, argv[4], -1, 0, 0, &pStmt, 0);
+    rc = db->errCode;
+    assert( (rc&0xFF)==(rcp&0xFF) );
+    db->init.iDb = saved_iDb;
+    /* assert( saved_iDb==0 || (db->mDbFlags & DBFLAG_Vacuum)!=0 ); */
+    if( SQLITE_OK!=rc ){
+      if( db->init.orphanTrigger ){
+        assert( iDb==1 );
+      }else{
+        if( rc > pData->rc ) pData->rc = rc;
+        if( rc==SQLITE_NOMEM ){
+          sqlite3OomFault(db);
+        }else if( rc!=SQLITE_INTERRUPT && (rc&0xFF)!=SQLITE_LOCKED ){
+          corruptSchema(pData, argv, sqlite3_errmsg(db));
+        }
+      }
+    }
+    db->init.azInit = sqlite3StdType; /* Any array of string ptrs will do */
+    sqlite3_finalize(pStmt);
+  }else if( argv[1]==0 || (argv[4]!=0 && argv[4][0]!=0) ){
+    corruptSchema(pData, argv, 0);
+  }else{
+    /* If the SQL column is blank it means this is an index that
+    ** was created to be the PRIMARY KEY or to fulfill a UNIQUE
+    ** constraint for a CREATE TABLE.  The index should have already
+    ** been created when we processed the CREATE TABLE.  All we have
+    ** to do here is record the root page number for that index.
+    */
+    Index *pIndex;
+    pIndex = sqlite3FindIndex(db, argv[1], db->aDb[iDb].zDbSName);
+    if( pIndex==0 ){
+      corruptSchema(pData, argv, "orphan index");
+    }else
+    if( sqlite3GetUInt32(argv[3],&pIndex->tnum)==0
+     || pIndex->tnum<2
+     || pIndex->tnum>pData->mxPage
+     || sqlite3IndexHasDuplicateRootPage(pIndex)
+    ){
+      if( sqlite3Config.bExtraSchemaChecks ){
+        corruptSchema(pData, argv, "invalid rootpage");
+      }
+    }
+  }
+  return 0;
+}
+
+/*
+** Attempt to read the database schema and initialize internal
+** data structures for a single database file.  The index of the
+** database file is given by iDb.  iDb==0 is used for the main
+** database.  iDb==1 should never be used.  iDb>=2 is used for
+** auxiliary databases.  Return one of the SQLITE_ error codes to
+** indicate success or failure.
+*/
+int sqlite3InitOne(sqlite3 *db, int iDb, char **pzErrMsg, u32 mFlags){
+  int rc;
+  int i;
+#ifndef SQLITE_OMIT_DEPRECATED
+  int size;
+#endif
+  Db *pDb;
+  char const *azArg[6];
+  int meta[5];
+  InitData initData;
+  const char *zSchemaTabName;
+  int openedTransaction = 0;
+  int mask = ((db->mDbFlags & DBFLAG_EncodingFixed) | ~DBFLAG_EncodingFixed);
+
+  assert( (db->mDbFlags & DBFLAG_SchemaKnownOk)==0 );
+  assert( iDb>=0 && iDb<db->nDb );
+  assert( db->aDb[iDb].pSchema );
+  assert( sqlite3_mutex_held(db->mutex) );
+  assert( iDb==1 || sqlite3BtreeHoldsMutex(db->aDb[iDb].pBt) );
+
+  db->init.busy = 1;
+
+  /* Construct the in-memory representation schema tables (sqlite_schema or
+  ** sqlite_temp_schema) by invoking the parser directly.  The appropriate
+  ** table name will be inserted automatically by the parser so we can just
+  ** use the abbreviation "x" here.  The parser will also automatically tag
+  ** the schema table as read-only. */
+  azArg[0] = "table";
+  azArg[1] = zSchemaTabName = SCHEMA_TABLE(iDb);
+  azArg[2] = azArg[1];
+  azArg[3] = "1";
+  azArg[4] = "CREATE TABLE x(type text,name text,tbl_name text,"
+                            "rootpage int,sql text)";
+  azArg[5] = 0;
+  initData.db = db;
+  initData.iDb = iDb;
+  initData.rc = SQLITE_OK;
+  initData.pzErrMsg = pzErrMsg;
+  initData.mInitFlags = mFlags;
+  initData.nInitRow = 0;
+  initData.mxPage = 0;
+  sqlite3InitCallback(&initData, 5, (char **)azArg, 0);
+  db->mDbFlags &= mask;
+  if( initData.rc ){
+    rc = initData.rc;
+    goto error_out;
+  }
+
+  /* Create a cursor to hold the database open
+  */
+  pDb = &db->aDb[iDb];
+  if( pDb->pBt==0 ){
+    assert( iDb==1 );
+    DbSetProperty(db, 1, DB_SchemaLoaded);
+    rc = SQLITE_OK;
+    goto error_out;
+  }
+
+  /* If there is not already a read-only (or read-write) transaction opened
+  ** on the b-tree database, open one now. If a transaction is opened, it 
+  ** will be closed before this function returns.  */
+  sqlite3BtreeEnter(pDb->pBt);
+  if( sqlite3BtreeTxnState(pDb->pBt)==SQLITE_TXN_NONE ){
+    rc = sqlite3BtreeBeginTrans(pDb->pBt, 0, 0);
+    if( rc!=SQLITE_OK ){
+      sqlite3SetString(pzErrMsg, db, sqlite3ErrStr(rc));
+      goto initone_error_out;
+    }
+    openedTransaction = 1;
+  }
+
+  /* Get the database meta information.
+  **
+  ** Meta values are as follows:
+  **    meta[0]   Schema cookie.  Changes with each schema change.
+  **    meta[1]   File format of schema layer.
+  **    meta[2]   Size of the page cache.
+  **    meta[3]   Largest rootpage (auto/incr_vacuum mode)
+  **    meta[4]   Db text encoding. 1:UTF-8 2:UTF-16LE 3:UTF-16BE
+  **    meta[5]   User version
+  **    meta[6]   Incremental vacuum mode
+  **    meta[7]   unused
+  **    meta[8]   unused
+  **    meta[9]   unused
+  **
+  ** Note: The #defined SQLITE_UTF* symbols in sqliteInt.h correspond to
+  ** the possible values of meta[4].
+  */
+  for(i=0; i<ArraySize(meta); i++){
+    sqlite3BtreeGetMeta(pDb->pBt, i+1, (u32 *)&meta[i]);
+  }
+  if( (db->flags & SQLITE_ResetDatabase)!=0 ){
+    memset(meta, 0, sizeof(meta));
+  }
+  pDb->pSchema->schema_cookie = meta[BTREE_SCHEMA_VERSION-1];
+
+  /* If opening a non-empty database, check the text encoding. For the
+  ** main database, set sqlite3.enc to the encoding of the main database.
+  ** For an attached db, it is an error if the encoding is not the same
+  ** as sqlite3.enc.
+  */
+  if( meta[BTREE_TEXT_ENCODING-1] ){  /* text encoding */
+    if( iDb==0 && (db->mDbFlags & DBFLAG_EncodingFixed)==0 ){
+      u8 encoding;
+#ifndef SQLITE_OMIT_UTF16
+      /* If opening the main database, set ENC(db). */
+      encoding = (u8)meta[BTREE_TEXT_ENCODING-1] & 3;
+      if( encoding==0 ) encoding = SQLITE_UTF8;
+#else
+      encoding = SQLITE_UTF8;
+#endif
+      if( db->nVdbeActive>0 && encoding!=ENC(db)
+       && (db->mDbFlags & DBFLAG_Vacuum)==0
+      ){
+        rc = SQLITE_LOCKED;
+        goto initone_error_out;
+      }else{
+        sqlite3SetTextEncoding(db, encoding);
+      }
+    }else{
+      /* If opening an attached database, the encoding much match ENC(db) */
+      if( (meta[BTREE_TEXT_ENCODING-1] & 3)!=ENC(db) ){
+        sqlite3SetString(pzErrMsg, db, "attached databases must use the same"
+            " text encoding as main database");
+        rc = SQLITE_ERROR;
+        goto initone_error_out;
+      }
+    }
+  }
+  pDb->pSchema->enc = ENC(db);
+
+  if( pDb->pSchema->cache_size==0 ){
+#ifndef SQLITE_OMIT_DEPRECATED
+    size = sqlite3AbsInt32(meta[BTREE_DEFAULT_CACHE_SIZE-1]);
+    if( size==0 ){ size = SQLITE_DEFAULT_CACHE_SIZE; }
+    pDb->pSchema->cache_size = size;
+#else
+    pDb->pSchema->cache_size = SQLITE_DEFAULT_CACHE_SIZE;
+#endif
+    sqlite3BtreeSetCacheSize(pDb->pBt, pDb->pSchema->cache_size);
+  }
+
+  /*
+  ** file_format==1    Version 3.0.0.
+  ** file_format==2    Version 3.1.3.  // ALTER TABLE ADD COLUMN
+  ** file_format==3    Version 3.1.4.  // ditto but with non-NULL defaults
+  ** file_format==4    Version 3.3.0.  // DESC indices.  Boolean constants
+  */
+  pDb->pSchema->file_format = (u8)meta[BTREE_FILE_FORMAT-1];
+  if( pDb->pSchema->file_format==0 ){
+    pDb->pSchema->file_format = 1;
+  }
+  if( pDb->pSchema->file_format>SQLITE_MAX_FILE_FORMAT ){
+    sqlite3SetString(pzErrMsg, db, "unsupported file format");
+    rc = SQLITE_ERROR;
+    goto initone_error_out;
+  }
+
+  /* Ticket #2804:  When we open a database in the newer file format,
+  ** clear the legacy_file_format pragma flag so that a VACUUM will
+  ** not downgrade the database and thus invalidate any descending
+  ** indices that the user might have created.
+  */
+  if( iDb==0 && meta[BTREE_FILE_FORMAT-1]>=4 ){
+    db->flags &= ~(u64)SQLITE_LegacyFileFmt;
+  }
+
+  /* Read the schema information out of the schema tables
+  */
+  assert( db->init.busy );
+  initData.mxPage = sqlite3BtreeLastPage(pDb->pBt);
+  {
+    char *zSql;
+    zSql = sqlite3MPrintf(db, 
+        "SELECT*FROM\"%w\".%s ORDER BY rowid",
+        db->aDb[iDb].zDbSName, zSchemaTabName);
+#ifndef SQLITE_OMIT_AUTHORIZATION
+    {
+      sqlite3_xauth xAuth;
+      xAuth = db->xAuth;
+      db->xAuth = 0;
+#endif
+      rc = sqlite3_exec(db, zSql, sqlite3InitCallback, &initData, 0);
+#ifndef SQLITE_OMIT_AUTHORIZATION
+      db->xAuth = xAuth;
+    }
+#endif
+    if( rc==SQLITE_OK ) rc = initData.rc;
+    sqlite3DbFree(db, zSql);
+#ifndef SQLITE_OMIT_ANALYZE
+    if( rc==SQLITE_OK ){
+      sqlite3AnalysisLoad(db, iDb);
+    }
+#endif
+  }
+  assert( pDb == &(db->aDb[iDb]) );
+  if( db->mallocFailed ){
+    rc = SQLITE_NOMEM_BKPT;
+    sqlite3ResetAllSchemasOfConnection(db);
+    pDb = &db->aDb[iDb];
+  }else
+  if( rc==SQLITE_OK || ((db->flags&SQLITE_NoSchemaError) && rc!=SQLITE_NOMEM)){
+    /* Hack: If the SQLITE_NoSchemaError flag is set, then consider
+    ** the schema loaded, even if errors (other than OOM) occurred. In
+    ** this situation the current sqlite3_prepare() operation will fail,
+    ** but the following one will attempt to compile the supplied statement
+    ** against whatever subset of the schema was loaded before the error
+    ** occurred.
+    **
+    ** The primary purpose of this is to allow access to the sqlite_schema
+    ** table even when its contents have been corrupted.
+    */
+    DbSetProperty(db, iDb, DB_SchemaLoaded);
+    rc = SQLITE_OK;
+  }
+
+  /* Jump here for an error that occurs after successfully allocating
+  ** curMain and calling sqlite3BtreeEnter(). For an error that occurs
+  ** before that point, jump to error_out.
+  */
+initone_error_out:
+  if( openedTransaction ){
+    sqlite3BtreeCommit(pDb->pBt);
+  }
+  sqlite3BtreeLeave(pDb->pBt);
+
+error_out:
+  if( rc ){
+    if( rc==SQLITE_NOMEM || rc==SQLITE_IOERR_NOMEM ){
+      sqlite3OomFault(db);
+    }
+    sqlite3ResetOneSchema(db, iDb);
+  }
+  db->init.busy = 0;
+  return rc;
+}
+
+/*
+** Initialize all database files - the main database file, the file
+** used to store temporary tables, and any additional database files
+** created using ATTACH statements.  Return a success code.  If an
+** error occurs, write an error message into *pzErrMsg.
+**
+** After a database is initialized, the DB_SchemaLoaded bit is set
+** bit is set in the flags field of the Db structure. 
+*/
+int sqlite3Init(sqlite3 *db, char **pzErrMsg){
+  int i, rc;
+  int commit_internal = !(db->mDbFlags&DBFLAG_SchemaChange);
+  
+  assert( sqlite3_mutex_held(db->mutex) );
+  assert( sqlite3BtreeHoldsMutex(db->aDb[0].pBt) );
+  assert( db->init.busy==0 );
+  ENC(db) = SCHEMA_ENC(db);
+  assert( db->nDb>0 );
+  /* Do the main schema first */
+  if( !DbHasProperty(db, 0, DB_SchemaLoaded) ){
+    rc = sqlite3InitOne(db, 0, pzErrMsg, 0);
+    if( rc ) return rc;
+  }
+  /* All other schemas after the main schema. The "temp" schema must be last */
+  for(i=db->nDb-1; i>0; i--){
+    assert( i==1 || sqlite3BtreeHoldsMutex(db->aDb[i].pBt) );
+    if( !DbHasProperty(db, i, DB_SchemaLoaded) ){
+      rc = sqlite3InitOne(db, i, pzErrMsg, 0);
+      if( rc ) return rc;
+    }
+  }
+  if( commit_internal ){
+    sqlite3CommitInternalChanges(db);
+  }
+  return SQLITE_OK;
+}
+
+/*
+** This routine is a no-op if the database schema is already initialized.
+** Otherwise, the schema is loaded. An error code is returned.
+*/
+int sqlite3ReadSchema(Parse *pParse){
+  int rc = SQLITE_OK;
+  sqlite3 *db = pParse->db;
+  assert( sqlite3_mutex_held(db->mutex) );
+  if( !db->init.busy ){
+    rc = sqlite3Init(db, &pParse->zErrMsg);
+    if( rc!=SQLITE_OK ){
+      pParse->rc = rc;
+      pParse->nErr++;
+    }else if( db->noSharedCache ){
+      db->mDbFlags |= DBFLAG_SchemaKnownOk;
+    }
+  }
+  return rc;
+}
+
+
+/*
+** Check schema cookies in all databases.  If any cookie is out
+** of date set pParse->rc to SQLITE_SCHEMA.  If all schema cookies
+** make no changes to pParse->rc.
+*/
+static void schemaIsValid(Parse *pParse){
+  sqlite3 *db = pParse->db;
+  int iDb;
+  int rc;
+  int cookie;
+
+  assert( pParse->checkSchema );
+  assert( sqlite3_mutex_held(db->mutex) );
+  for(iDb=0; iDb<db->nDb; iDb++){
+    int openedTransaction = 0;         /* True if a transaction is opened */
+    Btree *pBt = db->aDb[iDb].pBt;     /* Btree database to read cookie from */
+    if( pBt==0 ) continue;
+
+    /* If there is not already a read-only (or read-write) transaction opened
+    ** on the b-tree database, open one now. If a transaction is opened, it 
+    ** will be closed immediately after reading the meta-value. */
+    if( sqlite3BtreeTxnState(pBt)==SQLITE_TXN_NONE ){
+      rc = sqlite3BtreeBeginTrans(pBt, 0, 0);
+      if( rc==SQLITE_NOMEM || rc==SQLITE_IOERR_NOMEM ){
+        sqlite3OomFault(db);
+        pParse->rc = SQLITE_NOMEM;
+      }
+      if( rc!=SQLITE_OK ) return;
+      openedTransaction = 1;
+    }
+
+    /* Read the schema cookie from the database. If it does not match the 
+    ** value stored as part of the in-memory schema representation,
+    ** set Parse.rc to SQLITE_SCHEMA. */
+    sqlite3BtreeGetMeta(pBt, BTREE_SCHEMA_VERSION, (u32 *)&cookie);
+    assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
+    if( cookie!=db->aDb[iDb].pSchema->schema_cookie ){
+      if( DbHasProperty(db, iDb, DB_SchemaLoaded) ) pParse->rc = SQLITE_SCHEMA;
+      sqlite3ResetOneSchema(db, iDb);
+    }
+
+    /* Close the transaction, if one was opened. */
+    if( openedTransaction ){
+      sqlite3BtreeCommit(pBt);
+    }
+  }
+}
+
+/*
+** Convert a schema pointer into the iDb index that indicates
+** which database file in db->aDb[] the schema refers to.
+**
+** If the same database is attached more than once, the first
+** attached database is returned.
+*/
+int sqlite3SchemaToIndex(sqlite3 *db, Schema *pSchema){
+  int i = -32768;
+
+  /* If pSchema is NULL, then return -32768. This happens when code in 
+  ** expr.c is trying to resolve a reference to a transient table (i.e. one
+  ** created by a sub-select). In this case the return value of this 
+  ** function should never be used.
+  **
+  ** We return -32768 instead of the more usual -1 simply because using
+  ** -32768 as the incorrect index into db->aDb[] is much 
+  ** more likely to cause a segfault than -1 (of course there are assert()
+  ** statements too, but it never hurts to play the odds) and
+  ** -32768 will still fit into a 16-bit signed integer.
+  */
+  assert( sqlite3_mutex_held(db->mutex) );
+  if( pSchema ){
+    for(i=0; 1; i++){
+      assert( i<db->nDb );
+      if( db->aDb[i].pSchema==pSchema ){
+        break;
+      }
+    }
+    assert( i>=0 && i<db->nDb );
+  }
+  return i;
+}
+
+/*
+** Free all memory allocations in the pParse object
+*/
+void sqlite3ParseObjectReset(Parse *pParse){
+  sqlite3 *db = pParse->db;
+  assert( db!=0 );
+  assert( db->pParse==pParse );
+  assert( pParse->nested==0 );
+#ifndef SQLITE_OMIT_SHARED_CACHE
+  if( pParse->aTableLock ) sqlite3DbNNFreeNN(db, pParse->aTableLock);
+#endif
+  while( pParse->pCleanup ){
+    ParseCleanup *pCleanup = pParse->pCleanup;
+    pParse->pCleanup = pCleanup->pNext;
+    pCleanup->xCleanup(db, pCleanup->pPtr);
+    sqlite3DbNNFreeNN(db, pCleanup);
+  }
+  if( pParse->aLabel ) sqlite3DbNNFreeNN(db, pParse->aLabel);
+  if( pParse->pConstExpr ){
+    sqlite3ExprListDelete(db, pParse->pConstExpr);
+  }
+  assert( db->lookaside.bDisable >= pParse->disableLookaside );
+  db->lookaside.bDisable -= pParse->disableLookaside;
+  db->lookaside.sz = db->lookaside.bDisable ? 0 : db->lookaside.szTrue;
+  assert( pParse->db->pParse==pParse );
+  db->pParse = pParse->pOuterParse;
+}
+
+/*
+** Add a new cleanup operation to a Parser.  The cleanup should happen when
+** the parser object is destroyed.  But, beware: the cleanup might happen
+** immediately.
+**
+** Use this mechanism for uncommon cleanups.  There is a higher setup
+** cost for this mechanism (an extra malloc), so it should not be used
+** for common cleanups that happen on most calls.  But for less
+** common cleanups, we save a single NULL-pointer comparison in
+** sqlite3ParseObjectReset(), which reduces the total CPU cycle count.
+**
+** If a memory allocation error occurs, then the cleanup happens immediately.
+** When either SQLITE_DEBUG or SQLITE_COVERAGE_TEST are defined, the
+** pParse->earlyCleanup flag is set in that case.  Calling code show verify
+** that test cases exist for which this happens, to guard against possible
+** use-after-free errors following an OOM.  The preferred way to do this is
+** to immediately follow the call to this routine with:
+**
+**       testcase( pParse->earlyCleanup );
+**
+** This routine returns a copy of its pPtr input (the third parameter)
+** except if an early cleanup occurs, in which case it returns NULL.  So
+** another way to check for early cleanup is to check the return value.
+** Or, stop using the pPtr parameter with this call and use only its
+** return value thereafter.  Something like this:
+**
+**       pObj = sqlite3ParserAddCleanup(pParse, destructor, pObj);
+*/
+void *sqlite3ParserAddCleanup(
+  Parse *pParse,                      /* Destroy when this Parser finishes */
+  void (*xCleanup)(sqlite3*,void*),   /* The cleanup routine */
+  void *pPtr                          /* Pointer to object to be cleaned up */
+){
+  ParseCleanup *pCleanup = sqlite3DbMallocRaw(pParse->db, sizeof(*pCleanup));
+  if( pCleanup ){
+    pCleanup->pNext = pParse->pCleanup;
+    pParse->pCleanup = pCleanup;
+    pCleanup->pPtr = pPtr;
+    pCleanup->xCleanup = xCleanup;
+  }else{
+    xCleanup(pParse->db, pPtr);
+    pPtr = 0;
+#if defined(SQLITE_DEBUG) || defined(SQLITE_COVERAGE_TEST)
+    pParse->earlyCleanup = 1;
+#endif
+  }
+  return pPtr;
+}
+
+/*
+** Turn bulk memory into a valid Parse object and link that Parse object
+** into database connection db.
+**
+** Call sqlite3ParseObjectReset() to undo this operation.
+**
+** Caution:  Do not confuse this routine with sqlite3ParseObjectInit() which
+** is generated by Lemon.
+*/
+void sqlite3ParseObjectInit(Parse *pParse, sqlite3 *db){
+  memset(PARSE_HDR(pParse), 0, PARSE_HDR_SZ);
+  memset(PARSE_TAIL(pParse), 0, PARSE_TAIL_SZ);
+  assert( db->pParse!=pParse );
+  pParse->pOuterParse = db->pParse;
+  db->pParse = pParse;
+  pParse->db = db;
+  if( db->mallocFailed ) sqlite3ErrorMsg(pParse, "out of memory");
+}
+
+/*
+** Maximum number of times that we will try again to prepare a statement
+** that returns SQLITE_ERROR_RETRY.
+*/
+#ifndef SQLITE_MAX_PREPARE_RETRY
+# define SQLITE_MAX_PREPARE_RETRY 25
+#endif
+
+/*
+** Compile the UTF-8 encoded SQL statement zSql into a statement handle.
+*/
+static int sqlite3Prepare(
+  sqlite3 *db,              /* Database handle. */
+  const char *zSql,         /* UTF-8 encoded SQL statement. */
+  int nBytes,               /* Length of zSql in bytes. */
+  u32 prepFlags,            /* Zero or more SQLITE_PREPARE_* flags */
+  Vdbe *pReprepare,         /* VM being reprepared */
+  sqlite3_stmt **ppStmt,    /* OUT: A pointer to the prepared statement */
+  const char **pzTail       /* OUT: End of parsed string */
+){
+  int rc = SQLITE_OK;       /* Result code */
+  int i;                    /* Loop counter */
+  Parse sParse;             /* Parsing context */
+
+  /* sqlite3ParseObjectInit(&sParse, db); // inlined for performance */
+  memset(PARSE_HDR(&sParse), 0, PARSE_HDR_SZ);
+  memset(PARSE_TAIL(&sParse), 0, PARSE_TAIL_SZ);
+  sParse.pOuterParse = db->pParse;
+  db->pParse = &sParse;
+  sParse.db = db;
+  if( pReprepare ){
+    sParse.pReprepare = pReprepare;
+    sParse.explain = sqlite3_stmt_isexplain((sqlite3_stmt*)pReprepare);
+  }else{
+    assert( sParse.pReprepare==0 );
+  }
+  assert( ppStmt && *ppStmt==0 );
+  if( db->mallocFailed ){
+    sqlite3ErrorMsg(&sParse, "out of memory");
+    db->errCode = rc = SQLITE_NOMEM;
+    goto end_prepare;
+  }
+  assert( sqlite3_mutex_held(db->mutex) );
+
+  /* For a long-term use prepared statement avoid the use of
+  ** lookaside memory.
+  */
+  if( prepFlags & SQLITE_PREPARE_PERSISTENT ){
+    sParse.disableLookaside++;
+    DisableLookaside;
+  }
+  sParse.prepFlags = prepFlags & 0xff;
+
+  /* Check to verify that it is possible to get a read lock on all
+  ** database schemas.  The inability to get a read lock indicates that
+  ** some other database connection is holding a write-lock, which in
+  ** turn means that the other connection has made uncommitted changes
+  ** to the schema.
+  **
+  ** Were we to proceed and prepare the statement against the uncommitted
+  ** schema changes and if those schema changes are subsequently rolled
+  ** back and different changes are made in their place, then when this
+  ** prepared statement goes to run the schema cookie would fail to detect
+  ** the schema change.  Disaster would follow.
+  **
+  ** This thread is currently holding mutexes on all Btrees (because
+  ** of the sqlite3BtreeEnterAll() in sqlite3LockAndPrepare()) so it
+  ** is not possible for another thread to start a new schema change
+  ** while this routine is running.  Hence, we do not need to hold 
+  ** locks on the schema, we just need to make sure nobody else is 
+  ** holding them.
+  **
+  ** Note that setting READ_UNCOMMITTED overrides most lock detection,
+  ** but it does *not* override schema lock detection, so this all still
+  ** works even if READ_UNCOMMITTED is set.
+  */
+  if( !db->noSharedCache ){
+    for(i=0; i<db->nDb; i++) {
+      Btree *pBt = db->aDb[i].pBt;
+      if( pBt ){
+        assert( sqlite3BtreeHoldsMutex(pBt) );
+        rc = sqlite3BtreeSchemaLocked(pBt);
+        if( rc ){
+          const char *zDb = db->aDb[i].zDbSName;
+          sqlite3ErrorWithMsg(db, rc, "database schema is locked: %s", zDb);
+          testcase( db->flags & SQLITE_ReadUncommit );
+          goto end_prepare;
+        }
+      }
+    }
+  }
+
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+  if( db->pDisconnect ) sqlite3VtabUnlockList(db);
+#endif
+
+  if( nBytes>=0 && (nBytes==0 || zSql[nBytes-1]!=0) ){
+    char *zSqlCopy;
+    int mxLen = db->aLimit[SQLITE_LIMIT_SQL_LENGTH];
+    testcase( nBytes==mxLen );
+    testcase( nBytes==mxLen+1 );
+    if( nBytes>mxLen ){
+      sqlite3ErrorWithMsg(db, SQLITE_TOOBIG, "statement too long");
+      rc = sqlite3ApiExit(db, SQLITE_TOOBIG);
+      goto end_prepare;
+    }
+    zSqlCopy = sqlite3DbStrNDup(db, zSql, nBytes);
+    if( zSqlCopy ){
+      sqlite3RunParser(&sParse, zSqlCopy);
+      sParse.zTail = &zSql[sParse.zTail-zSqlCopy];
+      sqlite3DbFree(db, zSqlCopy);
+    }else{
+      sParse.zTail = &zSql[nBytes];
+    }
+  }else{
+    sqlite3RunParser(&sParse, zSql);
+  }
+  assert( 0==sParse.nQueryLoop );
+
+  if( pzTail ){
+    *pzTail = sParse.zTail;
+  }
+
+  if( db->init.busy==0 ){
+    sqlite3VdbeSetSql(sParse.pVdbe, zSql, (int)(sParse.zTail-zSql), prepFlags);
+  }
+  if( db->mallocFailed ){
+    sParse.rc = SQLITE_NOMEM_BKPT;
+    sParse.checkSchema = 0;
+  }
+  if( sParse.rc!=SQLITE_OK && sParse.rc!=SQLITE_DONE ){
+    if( sParse.checkSchema && db->init.busy==0 ){
+      schemaIsValid(&sParse);
+    }
+    if( sParse.pVdbe ){
+      sqlite3VdbeFinalize(sParse.pVdbe);
+    }
+    assert( 0==(*ppStmt) );
+    rc = sParse.rc;
+    if( sParse.zErrMsg ){
+      sqlite3ErrorWithMsg(db, rc, "%s", sParse.zErrMsg);
+      sqlite3DbFree(db, sParse.zErrMsg);
+    }else{
+      sqlite3Error(db, rc);
+    }
+  }else{
+    assert( sParse.zErrMsg==0 );
+    *ppStmt = (sqlite3_stmt*)sParse.pVdbe;
+    rc = SQLITE_OK;
+    sqlite3ErrorClear(db);
+  }
+
+
+  /* Delete any TriggerPrg structures allocated while parsing this statement. */
+  while( sParse.pTriggerPrg ){
+    TriggerPrg *pT = sParse.pTriggerPrg;
+    sParse.pTriggerPrg = pT->pNext;
+    sqlite3DbFree(db, pT);
+  }
+
+end_prepare:
+
+  sqlite3ParseObjectReset(&sParse);
+  return rc;
+}
+static int sqlite3LockAndPrepare(
+  sqlite3 *db,              /* Database handle. */
+  const char *zSql,         /* UTF-8 encoded SQL statement. */
+  int nBytes,               /* Length of zSql in bytes. */
+  u32 prepFlags,            /* Zero or more SQLITE_PREPARE_* flags */
+  Vdbe *pOld,               /* VM being reprepared */
+  sqlite3_stmt **ppStmt,    /* OUT: A pointer to the prepared statement */
+  const char **pzTail       /* OUT: End of parsed string */
+){
+  int rc;
+  int cnt = 0;
+
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( ppStmt==0 ) return SQLITE_MISUSE_BKPT;
+#endif
+  *ppStmt = 0;
+  if( !sqlite3SafetyCheckOk(db)||zSql==0 ){
+    return SQLITE_MISUSE_BKPT;
+  }
+  sqlite3_mutex_enter(db->mutex);
+  sqlite3BtreeEnterAll(db);
+  do{
+    /* Make multiple attempts to compile the SQL, until it either succeeds
+    ** or encounters a permanent error.  A schema problem after one schema
+    ** reset is considered a permanent error. */
+    rc = sqlite3Prepare(db, zSql, nBytes, prepFlags, pOld, ppStmt, pzTail);
+    assert( rc==SQLITE_OK || *ppStmt==0 );
+    if( rc==SQLITE_OK || db->mallocFailed ) break;
+  }while( (rc==SQLITE_ERROR_RETRY && (cnt++)<SQLITE_MAX_PREPARE_RETRY)
+       || (rc==SQLITE_SCHEMA && (sqlite3ResetOneSchema(db,-1), cnt++)==0) );
+  sqlite3BtreeLeaveAll(db);
+  rc = sqlite3ApiExit(db, rc);
+  assert( (rc&db->errMask)==rc );
+  db->busyHandler.nBusy = 0;
+  sqlite3_mutex_leave(db->mutex);
+  assert( rc==SQLITE_OK || (*ppStmt)==0 );
+  return rc;
+}
+
+
+/*
+** Rerun the compilation of a statement after a schema change.
+**
+** If the statement is successfully recompiled, return SQLITE_OK. Otherwise,
+** if the statement cannot be recompiled because another connection has
+** locked the sqlite3_schema table, return SQLITE_LOCKED. If any other error
+** occurs, return SQLITE_SCHEMA.
+*/
+int sqlite3Reprepare(Vdbe *p){
+  int rc;
+  sqlite3_stmt *pNew;
+  const char *zSql;
+  sqlite3 *db;
+  u8 prepFlags;
+
+  assert( sqlite3_mutex_held(sqlite3VdbeDb(p)->mutex) );
+  zSql = sqlite3_sql((sqlite3_stmt *)p);
+  assert( zSql!=0 );  /* Reprepare only called for prepare_v2() statements */
+  db = sqlite3VdbeDb(p);
+  assert( sqlite3_mutex_held(db->mutex) );
+  prepFlags = sqlite3VdbePrepareFlags(p);
+  rc = sqlite3LockAndPrepare(db, zSql, -1, prepFlags, p, &pNew, 0);
+  if( rc ){
+    if( rc==SQLITE_NOMEM ){
+      sqlite3OomFault(db);
+    }
+    assert( pNew==0 );
+    return rc;
+  }else{
+    assert( pNew!=0 );
+  }
+  sqlite3VdbeSwap((Vdbe*)pNew, p);
+  sqlite3TransferBindings(pNew, (sqlite3_stmt*)p);
+  sqlite3VdbeResetStepResult((Vdbe*)pNew);
+  sqlite3VdbeFinalize((Vdbe*)pNew);
+  return SQLITE_OK;
+}
+
+
+/*
+** Two versions of the official API.  Legacy and new use.  In the legacy
+** version, the original SQL text is not saved in the prepared statement
+** and so if a schema change occurs, SQLITE_SCHEMA is returned by
+** sqlite3_step().  In the new version, the original SQL text is retained
+** and the statement is automatically recompiled if an schema change
+** occurs.
+*/
+int sqlite3_prepare(
+  sqlite3 *db,              /* Database handle. */
+  const char *zSql,         /* UTF-8 encoded SQL statement. */
+  int nBytes,               /* Length of zSql in bytes. */
+  sqlite3_stmt **ppStmt,    /* OUT: A pointer to the prepared statement */
+  const char **pzTail       /* OUT: End of parsed string */
+){
+  int rc;
+  rc = sqlite3LockAndPrepare(db,zSql,nBytes,0,0,ppStmt,pzTail);
+  assert( rc==SQLITE_OK || ppStmt==0 || *ppStmt==0 );  /* VERIFY: F13021 */
+  return rc;
+}
+int sqlite3_prepare_v2(
+  sqlite3 *db,              /* Database handle. */
+  const char *zSql,         /* UTF-8 encoded SQL statement. */
+  int nBytes,               /* Length of zSql in bytes. */
+  sqlite3_stmt **ppStmt,    /* OUT: A pointer to the prepared statement */
+  const char **pzTail       /* OUT: End of parsed string */
+){
+  int rc;
+  /* EVIDENCE-OF: R-37923-12173 The sqlite3_prepare_v2() interface works
+  ** exactly the same as sqlite3_prepare_v3() with a zero prepFlags
+  ** parameter.
+  **
+  ** Proof in that the 5th parameter to sqlite3LockAndPrepare is 0 */
+  rc = sqlite3LockAndPrepare(db,zSql,nBytes,SQLITE_PREPARE_SAVESQL,0,
+                             ppStmt,pzTail);
+  assert( rc==SQLITE_OK || ppStmt==0 || *ppStmt==0 );
+  return rc;
+}
+int sqlite3_prepare_v3(
+  sqlite3 *db,              /* Database handle. */
+  const char *zSql,         /* UTF-8 encoded SQL statement. */
+  int nBytes,               /* Length of zSql in bytes. */
+  unsigned int prepFlags,   /* Zero or more SQLITE_PREPARE_* flags */
+  sqlite3_stmt **ppStmt,    /* OUT: A pointer to the prepared statement */
+  const char **pzTail       /* OUT: End of parsed string */
+){
+  int rc;
+  /* EVIDENCE-OF: R-56861-42673 sqlite3_prepare_v3() differs from
+  ** sqlite3_prepare_v2() only in having the extra prepFlags parameter,
+  ** which is a bit array consisting of zero or more of the
+  ** SQLITE_PREPARE_* flags.
+  **
+  ** Proof by comparison to the implementation of sqlite3_prepare_v2()
+  ** directly above. */
+  rc = sqlite3LockAndPrepare(db,zSql,nBytes,
+                 SQLITE_PREPARE_SAVESQL|(prepFlags&SQLITE_PREPARE_MASK),
+                 0,ppStmt,pzTail);
+  assert( rc==SQLITE_OK || ppStmt==0 || *ppStmt==0 );
+  return rc;
+}
+
+
+#ifndef SQLITE_OMIT_UTF16
+/*
+** Compile the UTF-16 encoded SQL statement zSql into a statement handle.
+*/
+static int sqlite3Prepare16(
+  sqlite3 *db,              /* Database handle. */ 
+  const void *zSql,         /* UTF-16 encoded SQL statement. */
+  int nBytes,               /* Length of zSql in bytes. */
+  u32 prepFlags,            /* Zero or more SQLITE_PREPARE_* flags */
+  sqlite3_stmt **ppStmt,    /* OUT: A pointer to the prepared statement */
+  const void **pzTail       /* OUT: End of parsed string */
+){
+  /* This function currently works by first transforming the UTF-16
+  ** encoded string to UTF-8, then invoking sqlite3_prepare(). The
+  ** tricky bit is figuring out the pointer to return in *pzTail.
+  */
+  char *zSql8;
+  const char *zTail8 = 0;
+  int rc = SQLITE_OK;
+
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( ppStmt==0 ) return SQLITE_MISUSE_BKPT;
+#endif
+  *ppStmt = 0;
+  if( !sqlite3SafetyCheckOk(db)||zSql==0 ){
+    return SQLITE_MISUSE_BKPT;
+  }
+  if( nBytes>=0 ){
+    int sz;
+    const char *z = (const char*)zSql;
+    for(sz=0; sz<nBytes && (z[sz]!=0 || z[sz+1]!=0); sz += 2){}
+    nBytes = sz;
+  }
+  sqlite3_mutex_enter(db->mutex);
+  zSql8 = sqlite3Utf16to8(db, zSql, nBytes, SQLITE_UTF16NATIVE);
+  if( zSql8 ){
+    rc = sqlite3LockAndPrepare(db, zSql8, -1, prepFlags, 0, ppStmt, &zTail8);
+  }
+
+  if( zTail8 && pzTail ){
+    /* If sqlite3_prepare returns a tail pointer, we calculate the
+    ** equivalent pointer into the UTF-16 string by counting the unicode
+    ** characters between zSql8 and zTail8, and then returning a pointer
+    ** the same number of characters into the UTF-16 string.
+    */
+    int chars_parsed = sqlite3Utf8CharLen(zSql8, (int)(zTail8-zSql8));
+    *pzTail = (u8 *)zSql + sqlite3Utf16ByteLen(zSql, chars_parsed);
+  }
+  sqlite3DbFree(db, zSql8); 
+  rc = sqlite3ApiExit(db, rc);
+  sqlite3_mutex_leave(db->mutex);
+  return rc;
+}
+
+/*
+** Two versions of the official API.  Legacy and new use.  In the legacy
+** version, the original SQL text is not saved in the prepared statement
+** and so if a schema change occurs, SQLITE_SCHEMA is returned by
+** sqlite3_step().  In the new version, the original SQL text is retained
+** and the statement is automatically recompiled if an schema change
+** occurs.
+*/
+int sqlite3_prepare16(
+  sqlite3 *db,              /* Database handle. */ 
+  const void *zSql,         /* UTF-16 encoded SQL statement. */
+  int nBytes,               /* Length of zSql in bytes. */
+  sqlite3_stmt **ppStmt,    /* OUT: A pointer to the prepared statement */
+  const void **pzTail       /* OUT: End of parsed string */
+){
+  int rc;
+  rc = sqlite3Prepare16(db,zSql,nBytes,0,ppStmt,pzTail);
+  assert( rc==SQLITE_OK || ppStmt==0 || *ppStmt==0 );  /* VERIFY: F13021 */
+  return rc;
+}
+int sqlite3_prepare16_v2(
+  sqlite3 *db,              /* Database handle. */ 
+  const void *zSql,         /* UTF-16 encoded SQL statement. */
+  int nBytes,               /* Length of zSql in bytes. */
+  sqlite3_stmt **ppStmt,    /* OUT: A pointer to the prepared statement */
+  const void **pzTail       /* OUT: End of parsed string */
+){
+  int rc;
+  rc = sqlite3Prepare16(db,zSql,nBytes,SQLITE_PREPARE_SAVESQL,ppStmt,pzTail);
+  assert( rc==SQLITE_OK || ppStmt==0 || *ppStmt==0 );  /* VERIFY: F13021 */
+  return rc;
+}
+int sqlite3_prepare16_v3(
+  sqlite3 *db,              /* Database handle. */ 
+  const void *zSql,         /* UTF-16 encoded SQL statement. */
+  int nBytes,               /* Length of zSql in bytes. */
+  unsigned int prepFlags,   /* Zero or more SQLITE_PREPARE_* flags */
+  sqlite3_stmt **ppStmt,    /* OUT: A pointer to the prepared statement */
+  const void **pzTail       /* OUT: End of parsed string */
+){
+  int rc;
+  rc = sqlite3Prepare16(db,zSql,nBytes,
+         SQLITE_PREPARE_SAVESQL|(prepFlags&SQLITE_PREPARE_MASK),
+         ppStmt,pzTail);
+  assert( rc==SQLITE_OK || ppStmt==0 || *ppStmt==0 );  /* VERIFY: F13021 */
+  return rc;
+}
+
+#endif /* SQLITE_OMIT_UTF16 */