/* ** Compile the UTF-8 encoded SQL statement zSql into a statement handle. */ 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 */ sqlite3_stmt **ppStmt, /* OUT: A pointer to the prepared statement */ const char **pzTail /* OUT: End of parsed string */ ){ Parse sParse; char *zErrMsg = 0; int rc = SQLITE_OK; int i; /* Assert that malloc() has not failed */ assert( !sqlite3MallocFailed() ); assert( ppStmt ); *ppStmt = 0; if( sqlite3SafetyOn(db) ){ return SQLITE_MISUSE; } /* If any attached database schemas are locked, do not proceed with ** compilation. Instead return SQLITE_LOCKED immediately. */ for(i=0; i<db->nDb; i++) { Btree *pBt = db->aDb[i].pBt; if( pBt && sqlite3BtreeSchemaLocked(pBt) ){ const char *zDb = db->aDb[i].zName; sqlite3Error(db, SQLITE_LOCKED, "database schema is locked: %s", zDb); sqlite3SafetyOff(db); return SQLITE_LOCKED; } } memset(&sParse, 0, sizeof(sParse)); sParse.db = db; if( nBytes>=0 && zSql[nBytes]!=0 ){ char *zSqlCopy = sqlite3StrNDup(zSql, nBytes); sqlite3RunParser(&sParse, zSqlCopy, &zErrMsg); sParse.zTail += zSql - zSqlCopy; sqliteFree(zSqlCopy); }else{ sqlite3RunParser(&sParse, zSql, &zErrMsg); } if( sqlite3MallocFailed() ){ sParse.rc = SQLITE_NOMEM; } if( sParse.rc==SQLITE_DONE ) sParse.rc = SQLITE_OK; if( sParse.checkSchema && !schemaIsValid(db) ){ sParse.rc = SQLITE_SCHEMA; } if( sParse.rc==SQLITE_SCHEMA ){ sqlite3ResetInternalSchema(db, 0); } if( sqlite3MallocFailed() ){ sParse.rc = SQLITE_NOMEM; } if( pzTail ){ *pzTail = sParse.zTail; } rc = sParse.rc; #ifndef SQLITE_OMIT_EXPLAIN if( rc==SQLITE_OK && sParse.pVdbe && sParse.explain ){ if( sParse.explain==2 ){ sqlite3VdbeSetNumCols(sParse.pVdbe, 3); sqlite3VdbeSetColName(sParse.pVdbe, 0, COLNAME_NAME, "order", P3_STATIC); sqlite3VdbeSetColName(sParse.pVdbe, 1, COLNAME_NAME, "from", P3_STATIC); sqlite3VdbeSetColName(sParse.pVdbe, 2, COLNAME_NAME, "detail", P3_STATIC); }else{ sqlite3VdbeSetNumCols(sParse.pVdbe, 5); sqlite3VdbeSetColName(sParse.pVdbe, 0, COLNAME_NAME, "addr", P3_STATIC); sqlite3VdbeSetColName(sParse.pVdbe, 1, COLNAME_NAME, "opcode", P3_STATIC); sqlite3VdbeSetColName(sParse.pVdbe, 2, COLNAME_NAME, "p1", P3_STATIC); sqlite3VdbeSetColName(sParse.pVdbe, 3, COLNAME_NAME, "p2", P3_STATIC); sqlite3VdbeSetColName(sParse.pVdbe, 4, COLNAME_NAME, "p3", P3_STATIC); } } #endif if( sqlite3SafetyOff(db) ){ rc = SQLITE_MISUSE; } if( rc==SQLITE_OK ){ if( saveSqlFlag ){ sqlite3VdbeSetSql(sParse.pVdbe, zSql, sParse.zTail - zSql); } *ppStmt = (sqlite3_stmt*)sParse.pVdbe; }else if( sParse.pVdbe ){ sqlite3_finalize((sqlite3_stmt*)sParse.pVdbe); } if( zErrMsg ){ sqlite3Error(db, rc, "%s", zErrMsg); sqliteFree(zErrMsg); }else{ sqlite3Error(db, rc, 0); } rc = sqlite3ApiExit(db, rc); sqlite3ReleaseThreadData(); assert( (rc&db->errMask)==rc ); return rc; }
/* ** Compile the UTF-8 encoded SQL statement zSql into a statement handle. */ 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 */ ){ Parse sParse; char *zErrMsg = 0; int rc = SQLITE_OK; if( sqlite3_malloc_failed ){ return SQLITE_NOMEM; } assert( ppStmt ); *ppStmt = 0; if( sqlite3SafetyOn(db) ){ return SQLITE_MISUSE; } memset(&sParse, 0, sizeof(sParse)); sParse.db = db; sqlite3RunParser(&sParse, zSql, &zErrMsg); if( sqlite3_malloc_failed ){ rc = SQLITE_NOMEM; sqlite3RollbackAll(db); sqlite3ResetInternalSchema(db, 0); db->flags &= ~SQLITE_InTrans; goto prepare_out; } if( sParse.rc==SQLITE_DONE ) sParse.rc = SQLITE_OK; if( sParse.rc!=SQLITE_OK && sParse.checkSchema && !schemaIsValid(db) ){ sParse.rc = SQLITE_SCHEMA; } if( sParse.rc==SQLITE_SCHEMA ){ sqlite3ResetInternalSchema(db, 0); } if( pzTail ) *pzTail = sParse.zTail; rc = sParse.rc; #ifndef SQLITE_OMIT_EXPLAIN if( rc==SQLITE_OK && sParse.pVdbe && sParse.explain ){ sqlite3VdbeSetNumCols(sParse.pVdbe, 5); sqlite3VdbeSetColName(sParse.pVdbe, 0, "addr", P3_STATIC); sqlite3VdbeSetColName(sParse.pVdbe, 1, "opcode", P3_STATIC); sqlite3VdbeSetColName(sParse.pVdbe, 2, "p1", P3_STATIC); sqlite3VdbeSetColName(sParse.pVdbe, 3, "p2", P3_STATIC); sqlite3VdbeSetColName(sParse.pVdbe, 4, "p3", P3_STATIC); } #endif prepare_out: if( sqlite3SafetyOff(db) ){ rc = SQLITE_MISUSE; } if( rc==SQLITE_OK ){ *ppStmt = (sqlite3_stmt*)sParse.pVdbe; }else if( sParse.pVdbe ){ sqlite3_finalize((sqlite3_stmt*)sParse.pVdbe); } if( zErrMsg ){ sqlite3Error(db, rc, "%s", zErrMsg); sqliteFree(zErrMsg); }else{ sqlite3Error(db, rc, 0); } return rc; }
/* ** 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 */ sqlite3_stmt **ppStmt, /* OUT: A pointer to the prepared statement */ const char **pzTail /* OUT: End of parsed string */ ){ Parse sParse; char *zErrMsg = 0; int rc = SQLITE_OK; int i; assert( ppStmt ); *ppStmt = 0; if( sqlite3SafetyOn(db) ){ return SQLITE_MISUSE; } 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); (void)sqlite3SafetyOff(db); testcase( db->flags & SQLITE_ReadUncommitted ); return sqlite3ApiExit(db, rc); } } } memset(&sParse, 0, sizeof(sParse)); sParse.db = db; if( nBytes>=0 && (nBytes==0 || zSql[nBytes-1]!=0) ){ char *zSqlCopy; int mxLen = db->aLimit[SQLITE_LIMIT_SQL_LENGTH]; if( nBytes>mxLen ){ sqlite3Error(db, SQLITE_TOOBIG, "statement too long"); (void)sqlite3SafetyOff(db); return sqlite3ApiExit(db, SQLITE_TOOBIG); } zSqlCopy = sqlite3DbStrNDup(db, zSql, nBytes); if( zSqlCopy ){ sqlite3RunParser(&sParse, zSqlCopy, &zErrMsg); sqlite3DbFree(db, zSqlCopy); sParse.zTail = &zSql[sParse.zTail-zSqlCopy]; }else{ sParse.zTail = &zSql[nBytes]; } }else{ sqlite3RunParser(&sParse, zSql, &zErrMsg); } if( db->mallocFailed ){ sParse.rc = SQLITE_NOMEM; } if( sParse.rc==SQLITE_DONE ) sParse.rc = SQLITE_OK; if( sParse.checkSchema && !schemaIsValid(db) ){ sParse.rc = SQLITE_SCHEMA; } if( sParse.rc==SQLITE_SCHEMA ){ sqlite3ResetInternalSchema(db, 0); } if( db->mallocFailed ){ sParse.rc = SQLITE_NOMEM; } if( pzTail ){ *pzTail = sParse.zTail; } rc = sParse.rc; #ifndef SQLITE_OMIT_EXPLAIN if( rc==SQLITE_OK && sParse.pVdbe && sParse.explain ){ if( sParse.explain==2 ){ sqlite3VdbeSetNumCols(sParse.pVdbe, 3); sqlite3VdbeSetColName(sParse.pVdbe, 0, COLNAME_NAME, "order", SQLITE_STATIC); sqlite3VdbeSetColName(sParse.pVdbe, 1, COLNAME_NAME, "from", SQLITE_STATIC); sqlite3VdbeSetColName(sParse.pVdbe, 2, COLNAME_NAME, "detail", SQLITE_STATIC); }else{ sqlite3VdbeSetNumCols(sParse.pVdbe, 8); sqlite3VdbeSetColName(sParse.pVdbe, 0, COLNAME_NAME, "addr", SQLITE_STATIC); sqlite3VdbeSetColName(sParse.pVdbe, 1, COLNAME_NAME, "opcode", SQLITE_STATIC); sqlite3VdbeSetColName(sParse.pVdbe, 2, COLNAME_NAME, "p1", SQLITE_STATIC); sqlite3VdbeSetColName(sParse.pVdbe, 3, COLNAME_NAME, "p2", SQLITE_STATIC); sqlite3VdbeSetColName(sParse.pVdbe, 4, COLNAME_NAME, "p3", SQLITE_STATIC); sqlite3VdbeSetColName(sParse.pVdbe, 5, COLNAME_NAME, "p4", SQLITE_STATIC); sqlite3VdbeSetColName(sParse.pVdbe, 6, COLNAME_NAME, "p5", SQLITE_STATIC); sqlite3VdbeSetColName(sParse.pVdbe, 7, COLNAME_NAME, "comment", SQLITE_STATIC); } } #endif if( sqlite3SafetyOff(db) ){ rc = SQLITE_MISUSE; } assert( db->init.busy==0 || saveSqlFlag==0 ); if( db->init.busy==0 ){ Vdbe *pVdbe = sParse.pVdbe; sqlite3VdbeSetSql(pVdbe, zSql, (int)(sParse.zTail-zSql), saveSqlFlag); } if( sParse.pVdbe && (rc!=SQLITE_OK || db->mallocFailed) ){ sqlite3VdbeFinalize(sParse.pVdbe); assert(!(*ppStmt)); }else{ *ppStmt = (sqlite3_stmt*)sParse.pVdbe; } if( zErrMsg ){ sqlite3Error(db, rc, "%s", zErrMsg); sqlite3DbFree(db, zErrMsg); }else{ sqlite3Error(db, rc, 0); } rc = sqlite3ApiExit(db, rc); assert( (rc&db->errMask)==rc ); return rc; }
/* ** 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; if( sqlite3SafetyOn(db) ){ rc = SQLITE_MISUSE; goto end_prepare; } 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); (void)sqlite3SafetyOff(db); testcase( db->flags & SQLITE_ReadUncommitted ); goto end_prepare; } } } sqlite3VtabUnlockList(db); pParse->db = db; 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"); (void)sqlite3SafetyOff(db); 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); } if( db->mallocFailed ){ pParse->rc = SQLITE_NOMEM; } if( pParse->rc==SQLITE_DONE ) pParse->rc = SQLITE_OK; if( pParse->checkSchema ){ schemaIsValid(pParse); } if( pParse->rc==SQLITE_SCHEMA ){ sqlite3ResetInternalSchema(db, 0); } 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", "order", "from", "detail" }; int iFirst, mx; if( pParse->explain==2 ){ sqlite3VdbeSetNumCols(pParse->pVdbe, 3); iFirst = 8; mx = 11; }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 if( sqlite3SafetyOff(db) ){ rc = SQLITE_MISUSE; } 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; sqlite3VdbeProgramDelete(db, pT->pProgram, 0); sqlite3DbFree(db, pT); } end_prepare: sqlite3StackFree(db, pParse); rc = sqlite3ApiExit(db, rc); assert( (rc&db->errMask)==rc ); return rc; }