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Diffstat (limited to 'src/prepare.c')
-rw-r--r-- | src/prepare.c | 858 |
1 files changed, 858 insertions, 0 deletions
diff --git a/src/prepare.c b/src/prepare.c new file mode 100644 index 0000000..fc45b8e --- /dev/null +++ b/src/prepare.c @@ -0,0 +1,858 @@ +/* +** 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 */ + const char *zObj, /* Object being parsed at the point of error */ + const char *zExtra /* Error information */ +){ + sqlite3 *db = pData->db; + if( !db->mallocFailed && (db->flags & SQLITE_RecoveryMode)==0 ){ + if( zObj==0 ) zObj = "?"; + sqlite3SetString(pData->pzErrMsg, db, + "malformed database schema (%s)", zObj); + if( zExtra ){ + *pData->pzErrMsg = sqlite3MAppendf(db, *pData->pzErrMsg, + "%s - %s", *pData->pzErrMsg, zExtra); + } + } + pData->rc = db->mallocFailed ? SQLITE_NOMEM : SQLITE_CORRUPT_BKPT; +} + +/* +** 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] = name of thing being created +** argv[1] = root page number for table or index. 0 for trigger or view. +** argv[2] = 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==3 ); + UNUSED_PARAMETER2(NotUsed, argc); + assert( sqlite3_mutex_held(db->mutex) ); + DbClearProperty(db, iDb, DB_Empty); + if( db->mallocFailed ){ + corruptSchema(pData, argv[0], 0); + return 1; + } + + assert( iDb>=0 && iDb<db->nDb ); + if( argv==0 ) return 0; /* Might happen if EMPTY_RESULT_CALLBACKS are on */ + if( argv[1]==0 ){ + corruptSchema(pData, argv[0], 0); + }else if( argv[2] && argv[2][0] ){ + /* 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. + */ + int rc; + sqlite3_stmt *pStmt; + TESTONLY(int rcp); /* Return code from sqlite3_prepare() */ + + assert( db->init.busy ); + db->init.iDb = iDb; + db->init.newTnum = sqlite3Atoi(argv[1]); + db->init.orphanTrigger = 0; + TESTONLY(rcp = ) sqlite3_prepare(db, argv[2], -1, &pStmt, 0); + rc = db->errCode; + assert( (rc&0xFF)==(rcp&0xFF) ); + db->init.iDb = 0; + if( SQLITE_OK!=rc ){ + if( db->init.orphanTrigger ){ + assert( iDb==1 ); + }else{ + pData->rc = rc; + if( rc==SQLITE_NOMEM ){ + db->mallocFailed = 1; + }else if( rc!=SQLITE_INTERRUPT && (rc&0xFF)!=SQLITE_LOCKED ){ + corruptSchema(pData, argv[0], sqlite3_errmsg(db)); + } + } + } + sqlite3_finalize(pStmt); + }else if( argv[0]==0 ){ + corruptSchema(pData, 0, 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[0], db->aDb[iDb].zName); + if( pIndex==0 ){ + /* This can occur if there exists an index on a TEMP table which + ** has the same name as another index on a permanent index. Since + ** the permanent table is hidden by the TEMP table, we can also + ** safely ignore the index on the permanent table. + */ + /* Do Nothing */; + }else if( sqlite3GetInt32(argv[1], &pIndex->tnum)==0 ){ + corruptSchema(pData, argv[0], "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. +*/ +static int sqlite3InitOne(sqlite3 *db, int iDb, char **pzErrMsg){ + int rc; + int i; + int size; + Table *pTab; + Db *pDb; + char const *azArg[4]; + int meta[5]; + InitData initData; + char const *zMasterSchema; + char const *zMasterName; + int openedTransaction = 0; + + /* + ** The master database table has a structure like this + */ + static const char master_schema[] = + "CREATE TABLE sqlite_master(\n" + " type text,\n" + " name text,\n" + " tbl_name text,\n" + " rootpage integer,\n" + " sql text\n" + ")" + ; +#ifndef SQLITE_OMIT_TEMPDB + static const char temp_master_schema[] = + "CREATE TEMP TABLE sqlite_temp_master(\n" + " type text,\n" + " name text,\n" + " tbl_name text,\n" + " rootpage integer,\n" + " sql text\n" + ")" + ; +#else + #define temp_master_schema 0 +#endif + + 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) ); + + /* zMasterSchema and zInitScript are set to point at the master schema + ** and initialisation script appropriate for the database being + ** initialised. zMasterName is the name of the master table. + */ + if( !OMIT_TEMPDB && iDb==1 ){ + zMasterSchema = temp_master_schema; + }else{ + zMasterSchema = master_schema; + } + zMasterName = SCHEMA_TABLE(iDb); + + /* Construct the schema tables. */ + azArg[0] = zMasterName; + azArg[1] = "1"; + azArg[2] = zMasterSchema; + azArg[3] = 0; + initData.db = db; + initData.iDb = iDb; + initData.rc = SQLITE_OK; + initData.pzErrMsg = pzErrMsg; + sqlite3InitCallback(&initData, 3, (char **)azArg, 0); + if( initData.rc ){ + rc = initData.rc; + goto error_out; + } + pTab = sqlite3FindTable(db, zMasterName, db->aDb[iDb].zName); + if( ALWAYS(pTab) ){ + pTab->tabFlags |= TF_Readonly; + } + + /* Create a cursor to hold the database open + */ + pDb = &db->aDb[iDb]; + if( pDb->pBt==0 ){ + if( !OMIT_TEMPDB && ALWAYS(iDb==1) ){ + DbSetProperty(db, 1, DB_SchemaLoaded); + } + return SQLITE_OK; + } + + /* 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( !sqlite3BtreeIsInReadTrans(pDb->pBt) ){ + rc = sqlite3BtreeBeginTrans(pDb->pBt, 0); + if( rc!=SQLITE_OK ){ + sqlite3SetString(pzErrMsg, db, "%s", 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]); + } + 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 ){ + u8 encoding; + /* If opening the main database, set ENC(db). */ + encoding = (u8)meta[BTREE_TEXT_ENCODING-1] & 3; + if( encoding==0 ) encoding = SQLITE_UTF8; + ENC(db) = encoding; + db->pDfltColl = sqlite3FindCollSeq(db, SQLITE_UTF8, "BINARY", 0); + }else{ + /* If opening an attached database, the encoding much match ENC(db) */ + if( meta[BTREE_TEXT_ENCODING-1]!=ENC(db) ){ + sqlite3SetString(pzErrMsg, db, "attached databases must use the same" + " text encoding as main database"); + rc = SQLITE_ERROR; + goto initone_error_out; + } + } + }else{ + DbSetProperty(db, iDb, DB_Empty); + } + pDb->pSchema->enc = ENC(db); + + if( pDb->pSchema->cache_size==0 ){ + size = sqlite3AbsInt32(meta[BTREE_DEFAULT_CACHE_SIZE-1]); + if( size==0 ){ size = SQLITE_DEFAULT_CACHE_SIZE; } + pDb->pSchema->cache_size = size; + 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 &= ~SQLITE_LegacyFileFmt; + } + + /* Read the schema information out of the schema tables + */ + assert( db->init.busy ); + { + char *zSql; + zSql = sqlite3MPrintf(db, + "SELECT name, rootpage, sql FROM '%q'.%s ORDER BY rowid", + db->aDb[iDb].zName, zMasterName); +#ifndef SQLITE_OMIT_AUTHORIZATION + { + int (*xAuth)(void*,int,const char*,const char*,const char*,const char*); + 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 + } + if( db->mallocFailed ){ + rc = SQLITE_NOMEM; + sqlite3ResetInternalSchema(db, -1); + } + if( rc==SQLITE_OK || (db->flags&SQLITE_RecoveryMode)){ + /* Black magic: If the SQLITE_RecoveryMode flag is set, then consider + ** the schema loaded, even if errors 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_master 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==SQLITE_NOMEM || rc==SQLITE_IOERR_NOMEM ){ + db->mallocFailed = 1; + } + 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. If the database +** file was of zero-length, then the DB_Empty flag is also set. +*/ +int sqlite3Init(sqlite3 *db, char **pzErrMsg){ + int i, rc; + int commit_internal = !(db->flags&SQLITE_InternChanges); + + assert( sqlite3_mutex_held(db->mutex) ); + rc = SQLITE_OK; + db->init.busy = 1; + for(i=0; rc==SQLITE_OK && i<db->nDb; i++){ + if( DbHasProperty(db, i, DB_SchemaLoaded) || i==1 ) continue; + rc = sqlite3InitOne(db, i, pzErrMsg); + if( rc ){ + sqlite3ResetInternalSchema(db, i); + } + } + + /* Once all the other databases have been initialised, load the schema + ** for the TEMP database. This is loaded last, as the TEMP database + ** schema may contain references to objects in other databases. + */ +#ifndef SQLITE_OMIT_TEMPDB + if( rc==SQLITE_OK && ALWAYS(db->nDb>1) + && !DbHasProperty(db, 1, DB_SchemaLoaded) ){ + rc = sqlite3InitOne(db, 1, pzErrMsg); + if( rc ){ + sqlite3ResetInternalSchema(db, 1); + } + } +#endif + + db->init.busy = 0; + if( rc==SQLITE_OK && commit_internal ){ + sqlite3CommitInternalChanges(db); + } + + return rc; +} + +/* +** This routine is a no-op if the database schema is already initialised. +** 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++; + } + 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( !sqlite3BtreeIsInReadTrans(pBt) ){ + rc = sqlite3BtreeBeginTrans(pBt, 0); + if( rc==SQLITE_NOMEM || rc==SQLITE_IOERR_NOMEM ){ + db->mallocFailed = 1; + } + 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 ){ + sqlite3ResetInternalSchema(db, iDb); + pParse->rc = SQLITE_SCHEMA; + } + + /* 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 = -1000000; + + /* If pSchema is NULL, then return -1000000. 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 -1000000 instead of the more usual -1 simply because using + ** -1000000 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). + */ + assert( sqlite3_mutex_held(db->mutex) ); + if( pSchema ){ + for(i=0; ALWAYS(i<db->nDb); i++){ + if( db->aDb[i].pSchema==pSchema ){ + break; + } + } + assert( i>=0 && i<db->nDb ); + } + return i; +} + +/* +** 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. */ + int saveSqlFlag, /* True to copy SQL text into the sqlite3_stmt */ + Vdbe *pReprepare, /* VM being reprepared */ + sqlite3_stmt **ppStmt, /* OUT: A pointer to the prepared statement */ + const char **pzTail /* OUT: End of parsed string */ +){ + Parse *pParse; /* Parsing context */ + char *zErrMsg = 0; /* Error message */ + int rc = SQLITE_OK; /* Result code */ + int i; /* Loop counter */ + + /* Allocate the parsing context */ + pParse = sqlite3StackAllocZero(db, sizeof(*pParse)); + if( pParse==0 ){ + rc = SQLITE_NOMEM; + goto end_prepare; + } + pParse->pReprepare = pReprepare; + assert( ppStmt && *ppStmt==0 ); + assert( !db->mallocFailed ); + assert( sqlite3_mutex_held(db->mutex) ); + + /* 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. + */ + 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].zName; + sqlite3Error(db, rc, "database schema is locked: %s", zDb); + testcase( db->flags & SQLITE_ReadUncommitted ); + goto end_prepare; + } + } + } + + sqlite3VtabUnlockList(db); + + pParse->db = db; + pParse->nQueryLoop = (double)1; + 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 ){ + sqlite3Error(db, SQLITE_TOOBIG, "statement too long"); + rc = sqlite3ApiExit(db, SQLITE_TOOBIG); + goto end_prepare; + } + zSqlCopy = sqlite3DbStrNDup(db, zSql, nBytes); + if( zSqlCopy ){ + sqlite3RunParser(pParse, zSqlCopy, &zErrMsg); + sqlite3DbFree(db, zSqlCopy); + pParse->zTail = &zSql[pParse->zTail-zSqlCopy]; + }else{ + pParse->zTail = &zSql[nBytes]; + } + }else{ + sqlite3RunParser(pParse, zSql, &zErrMsg); + } + assert( 1==(int)pParse->nQueryLoop ); + + if( db->mallocFailed ){ + pParse->rc = SQLITE_NOMEM; + } + if( pParse->rc==SQLITE_DONE ) pParse->rc = SQLITE_OK; + if( pParse->checkSchema ){ + schemaIsValid(pParse); + } + if( db->mallocFailed ){ + pParse->rc = SQLITE_NOMEM; + } + if( pzTail ){ + *pzTail = pParse->zTail; + } + rc = pParse->rc; + +#ifndef SQLITE_OMIT_EXPLAIN + if( rc==SQLITE_OK && pParse->pVdbe && pParse->explain ){ + static const char * const azColName[] = { + "addr", "opcode", "p1", "p2", "p3", "p4", "p5", "comment", + "selectid", "order", "from", "detail" + }; + int iFirst, mx; + if( pParse->explain==2 ){ + sqlite3VdbeSetNumCols(pParse->pVdbe, 4); + iFirst = 8; + mx = 12; + }else{ + sqlite3VdbeSetNumCols(pParse->pVdbe, 8); + iFirst = 0; + mx = 8; + } + for(i=iFirst; i<mx; i++){ + sqlite3VdbeSetColName(pParse->pVdbe, i-iFirst, COLNAME_NAME, + azColName[i], SQLITE_STATIC); + } + } +#endif + + assert( db->init.busy==0 || saveSqlFlag==0 ); + if( db->init.busy==0 ){ + Vdbe *pVdbe = pParse->pVdbe; + sqlite3VdbeSetSql(pVdbe, zSql, (int)(pParse->zTail-zSql), saveSqlFlag); + } + if( pParse->pVdbe && (rc!=SQLITE_OK || db->mallocFailed) ){ + sqlite3VdbeFinalize(pParse->pVdbe); + assert(!(*ppStmt)); + }else{ + *ppStmt = (sqlite3_stmt*)pParse->pVdbe; + } + + if( zErrMsg ){ + sqlite3Error(db, rc, "%s", zErrMsg); + sqlite3DbFree(db, zErrMsg); + }else{ + sqlite3Error(db, rc, 0); + } + + /* Delete any TriggerPrg structures allocated while parsing this statement. */ + while( pParse->pTriggerPrg ){ + TriggerPrg *pT = pParse->pTriggerPrg; + pParse->pTriggerPrg = pT->pNext; + sqlite3DbFree(db, pT); + } + +end_prepare: + + sqlite3StackFree(db, pParse); + rc = sqlite3ApiExit(db, rc); + assert( (rc&db->errMask)==rc ); + return rc; +} +static int sqlite3LockAndPrepare( + sqlite3 *db, /* Database handle. */ + const char *zSql, /* UTF-8 encoded SQL statement. */ + int nBytes, /* Length of zSql in bytes. */ + int saveSqlFlag, /* True to copy SQL text into the sqlite3_stmt */ + 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; + assert( ppStmt!=0 ); + *ppStmt = 0; + if( !sqlite3SafetyCheckOk(db) ){ + return SQLITE_MISUSE_BKPT; + } + sqlite3_mutex_enter(db->mutex); + sqlite3BtreeEnterAll(db); + rc = sqlite3Prepare(db, zSql, nBytes, saveSqlFlag, pOld, ppStmt, pzTail); + if( rc==SQLITE_SCHEMA ){ + sqlite3_finalize(*ppStmt); + rc = sqlite3Prepare(db, zSql, nBytes, saveSqlFlag, pOld, ppStmt, pzTail); + } + sqlite3BtreeLeaveAll(db); + sqlite3_mutex_leave(db->mutex); + 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_master 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; + + 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) ); + rc = sqlite3LockAndPrepare(db, zSql, -1, 0, p, &pNew, 0); + if( rc ){ + if( rc==SQLITE_NOMEM ){ + db->mallocFailed = 1; + } + 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; + rc = sqlite3LockAndPrepare(db,zSql,nBytes,1,0,ppStmt,pzTail); + assert( rc==SQLITE_OK || ppStmt==0 || *ppStmt==0 ); /* VERIFY: F13021 */ + 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. */ + int saveSqlFlag, /* True to save SQL text into the sqlite3_stmt */ + 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; + + assert( ppStmt ); + *ppStmt = 0; + if( !sqlite3SafetyCheckOk(db) ){ + return SQLITE_MISUSE_BKPT; + } + sqlite3_mutex_enter(db->mutex); + zSql8 = sqlite3Utf16to8(db, zSql, nBytes, SQLITE_UTF16NATIVE); + if( zSql8 ){ + rc = sqlite3LockAndPrepare(db, zSql8, -1, saveSqlFlag, 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,1,ppStmt,pzTail); + assert( rc==SQLITE_OK || ppStmt==0 || *ppStmt==0 ); /* VERIFY: F13021 */ + return rc; +} + +#endif /* SQLITE_OMIT_UTF16 */ |