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Diffstat (limited to 'src/prepare.c')
| -rw-r--r-- | src/prepare.c | 1079 |
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 */ |