/* ** Return a pointer corresponding to database zDb (i.e. "main", "temp") ** in connection handle pDb. If such a database cannot be found, return ** a NULL pointer and write an error message to pErrorDb. ** ** If the "temp" database is requested, it may need to be opened by this ** function. If an error occurs while doing so, return 0 and write an ** error message to pErrorDb. */ static Btree *findBtree(sqlite3 *pErrorDb, sqlite3 *pDb, const char *zDb) { int i = sqlite3FindDbName(pDb, zDb); if( i==1 ) { Parse *pParse; int rc = 0; pParse = sqlite3StackAllocZero(pErrorDb, sizeof(*pParse)); if( pParse==0 ) { sqlite3Error(pErrorDb, SQLITE_NOMEM, "out of memory"); rc = SQLITE_NOMEM; } else { pParse->db = pDb; if( sqlite3OpenTempDatabase(pParse) ) { sqlite3Error(pErrorDb, pParse->rc, "%s", pParse->zErrMsg); rc = SQLITE_ERROR; } sqlite3DbFree(pErrorDb, pParse->zErrMsg); sqlite3StackFree(pErrorDb, pParse); } if( rc ) { return 0; } } if( i<0 ) { sqlite3Error(pErrorDb, SQLITE_ERROR, "unknown database %s", zDb); return 0; } return pDb->aDb[i].pBt; }
/* ** This function is used to set the schema of a virtual table. It is only ** valid to call this function from within the xCreate() or xConnect() of a ** virtual table module. */ int sqlite3_declare_vtab(sqlite3 *db, const char *zCreateTable){ Parse *pParse; int rc = SQLITE_OK; Table *pTab; char *zErr = 0; sqlite3_mutex_enter(db->mutex); if( !db->pVtabCtx || !(pTab = db->pVtabCtx->pTab) ){ sqlite3Error(db, SQLITE_MISUSE); sqlite3_mutex_leave(db->mutex); return SQLITE_MISUSE_BKPT; } assert( (pTab->tabFlags & TF_Virtual)!=0 ); pParse = sqlite3StackAllocZero(db, sizeof(*pParse)); if( pParse==0 ){ rc = SQLITE_NOMEM; }else{ pParse->declareVtab = 1; pParse->db = db; pParse->nQueryLoop = 1; if( SQLITE_OK==sqlite3RunParser(pParse, zCreateTable, &zErr) && pParse->pNewTable && !db->mallocFailed && !pParse->pNewTable->pSelect && (pParse->pNewTable->tabFlags & TF_Virtual)==0 ){ if( !pTab->aCol ){ pTab->aCol = pParse->pNewTable->aCol; pTab->nCol = pParse->pNewTable->nCol; pParse->pNewTable->nCol = 0; pParse->pNewTable->aCol = 0; } db->pVtabCtx->pTab = 0; }else{ sqlite3ErrorWithMsg(db, SQLITE_ERROR, (zErr ? "%s" : 0), zErr); sqlite3DbFree(db, zErr); rc = SQLITE_ERROR; } pParse->declareVtab = 0; if( pParse->pVdbe ){ sqlite3VdbeFinalize(pParse->pVdbe); } sqlite3DeleteTable(db, pParse->pNewTable); sqlite3ParserReset(pParse); sqlite3StackFree(db, pParse); } assert( (rc&0xff)==rc ); rc = sqlite3ApiExit(db, rc); sqlite3_mutex_leave(db->mutex); return rc; }
/* ** This function is used to set the schema of a virtual table. It is only ** valid to call this function from within the xCreate() or xConnect() of a ** virtual table module. */ int sqlite3_declare_vtab(sqlite3 *db, const char *zCreateTable){ VtabCtx *pCtx; Parse *pParse; int rc = SQLITE_OK; Table *pTab; char *zErr = 0; #ifdef SQLITE_ENABLE_API_ARMOR if( !sqlite3SafetyCheckOk(db) || zCreateTable==0 ){ return SQLITE_MISUSE_BKPT; } #endif sqlite3_mutex_enter(db->mutex); pCtx = db->pVtabCtx; if( !pCtx || pCtx->bDeclared ){ sqlite3Error(db, SQLITE_MISUSE); sqlite3_mutex_leave(db->mutex); return SQLITE_MISUSE_BKPT; } pTab = pCtx->pTab; assert( (pTab->tabFlags & TF_Virtual)!=0 ); pParse = sqlite3StackAllocZero(db, sizeof(*pParse)); if( pParse==0 ){ rc = SQLITE_NOMEM_BKPT; }else{ pParse->declareVtab = 1; pParse->db = db; pParse->nQueryLoop = 1; if( SQLITE_OK==sqlite3RunParser(pParse, zCreateTable, &zErr) && pParse->pNewTable && !db->mallocFailed && !pParse->pNewTable->pSelect && (pParse->pNewTable->tabFlags & TF_Virtual)==0 ){ if( !pTab->aCol ){ Table *pNew = pParse->pNewTable; Index *pIdx; pTab->aCol = pNew->aCol; pTab->nCol = pNew->nCol; pTab->tabFlags |= pNew->tabFlags & (TF_WithoutRowid|TF_NoVisibleRowid); pNew->nCol = 0; pNew->aCol = 0; assert( pTab->pIndex==0 ); if( !HasRowid(pNew) && pCtx->pVTable->pMod->pModule->xUpdate!=0 ){ rc = SQLITE_ERROR; } pIdx = pNew->pIndex; if( pIdx ){ assert( pIdx->pNext==0 ); pTab->pIndex = pIdx; pNew->pIndex = 0; pIdx->pTable = pTab; } } pCtx->bDeclared = 1; }else{ sqlite3ErrorWithMsg(db, SQLITE_ERROR, (zErr ? "%s" : 0), zErr); sqlite3DbFree(db, zErr); rc = SQLITE_ERROR; } pParse->declareVtab = 0; if( pParse->pVdbe ){ sqlite3VdbeFinalize(pParse->pVdbe); } sqlite3DeleteTable(db, pParse->pNewTable); sqlite3ParserReset(pParse); sqlite3StackFree(db, pParse); } assert( (rc&0xff)==rc ); rc = sqlite3ApiExit(db, rc); sqlite3_mutex_leave(db->mutex); return rc; }
/* ** Attempt to load an SQLite extension library contained in the file ** zFile. The entry point is zProc. zProc may be 0 in which case a ** default entry point name (sqlite3_extension_init) is used. Use ** of the default name is recommended. ** ** Return SQLITE_OK on success and SQLITE_ERROR if something goes wrong. ** ** If an error occurs and pzErrMsg is not 0, then fill *pzErrMsg with ** error message text. The calling function should free this memory ** by calling sqlite3DbFree(db, ). */ static int sqlite3LoadExtension( sqlite3 *db, /* Load the extension into this database connection */ const char *zFile, /* Name of the shared library containing extension */ const char *zProc, /* Entry point. Use "sqlite3_extension_init" if 0 */ char **pzErrMsg /* Put error message here if not 0 */ ){ sqlite3_vfs *pVfs = db->pVfs; void *handle; int (*xInit)(sqlite3*,char**,const sqlite3_api_routines*); char *zErrmsg = 0; void **aHandle; const int nMsg = 300; if( pzErrMsg ) *pzErrMsg = 0; /* Ticket #1863. To avoid a creating security problems for older ** applications that relink against newer versions of SQLite, the ** ability to run load_extension is turned off by default. One ** must call sqlite3_enable_load_extension() to turn on extension ** loading. Otherwise you get the following error. */ if( (db->flags & SQLITE_LoadExtension)==0 ){ if( pzErrMsg ){ *pzErrMsg = sqlite3_mprintf("not authorized"); } return SQLITE_ERROR; } if( zProc==0 ){ zProc = "sqlite3_extension_init"; } handle = sqlite3OsDlOpen(pVfs, zFile); if( handle==0 ){ if( pzErrMsg ){ zErrmsg = sqlite3StackAllocZero(db, nMsg); if( zErrmsg ){ sqlite3_snprintf(nMsg, zErrmsg, "unable to open shared library [%s]", zFile); sqlite3OsDlError(pVfs, nMsg-1, zErrmsg); *pzErrMsg = sqlite3DbStrDup(0, zErrmsg); sqlite3StackFree(db, zErrmsg); } } return SQLITE_ERROR; } xInit = (int(*)(sqlite3*,char**,const sqlite3_api_routines*)) sqlite3OsDlSym(pVfs, handle, zProc); if( xInit==0 ){ if( pzErrMsg ){ zErrmsg = sqlite3StackAllocZero(db, nMsg); if( zErrmsg ){ sqlite3_snprintf(nMsg, zErrmsg, "no entry point [%s] in shared library [%s]", zProc,zFile); sqlite3OsDlError(pVfs, nMsg-1, zErrmsg); *pzErrMsg = sqlite3DbStrDup(0, zErrmsg); sqlite3StackFree(db, zErrmsg); } sqlite3OsDlClose(pVfs, handle); } return SQLITE_ERROR; }else if( xInit(db, &zErrmsg, &sqlite3Apis) ){ if( pzErrMsg ){ *pzErrMsg = sqlite3_mprintf("error during initialization: %s", zErrmsg); } sqlite3_free(zErrmsg); sqlite3OsDlClose(pVfs, handle); return SQLITE_ERROR; } /* Append the new shared library handle to the db->aExtension array. */ aHandle = sqlite3DbMallocZero(db, sizeof(handle)*(db->nExtension+1)); if( aHandle==0 ){ return SQLITE_NOMEM; } if( db->nExtension>0 ){ memcpy(aHandle, db->aExtension, sizeof(handle)*db->nExtension); } sqlite3DbFree(db, db->aExtension); db->aExtension = aHandle; db->aExtension[db->nExtension++] = handle; return SQLITE_OK; }
/* ** Create and populate a new TriggerPrg object with a sub-program ** implementing trigger pTrigger with ON CONFLICT policy orconf. */ static TriggerPrg *codeRowTrigger( Parse *pParse, /* Current parse context */ Trigger *pTrigger, /* Trigger to code */ Table *pTab, /* The table pTrigger is attached to */ int orconf /* ON CONFLICT policy to code trigger program with */ ){ Parse *pTop = sqlite3ParseToplevel(pParse); sqlite3 *db = pParse->db; /* Database handle */ TriggerPrg *pPrg; /* Value to return */ Expr *pWhen = 0; /* Duplicate of trigger WHEN expression */ Vdbe *v; /* Temporary VM */ NameContext sNC; /* Name context for sub-vdbe */ SubProgram *pProgram = 0; /* Sub-vdbe for trigger program */ Parse *pSubParse; /* Parse context for sub-vdbe */ int iEndTrigger = 0; /* Label to jump to if WHEN is false */ assert( pTrigger->zName==0 || pTab==tableOfTrigger(pTrigger) ); assert( pTop->pVdbe ); /* Allocate the TriggerPrg and SubProgram objects. To ensure that they ** are freed if an error occurs, link them into the Parse.pTriggerPrg ** list of the top-level Parse object sooner rather than later. */ pPrg = sqlite3DbMallocZero(db, sizeof(TriggerPrg)); if( !pPrg ) return 0; pPrg->pNext = pTop->pTriggerPrg; pTop->pTriggerPrg = pPrg; pPrg->pProgram = pProgram = sqlite3DbMallocZero(db, sizeof(SubProgram)); if( !pProgram ) return 0; sqlite3VdbeLinkSubProgram(pTop->pVdbe, pProgram); pPrg->pTrigger = pTrigger; pPrg->orconf = orconf; pPrg->aColmask[0] = 0xffffffff; pPrg->aColmask[1] = 0xffffffff; /* Allocate and populate a new Parse context to use for coding the ** trigger sub-program. */ pSubParse = sqlite3StackAllocZero(db, sizeof(Parse)); if( !pSubParse ) return 0; memset(&sNC, 0, sizeof(sNC)); sNC.pParse = pSubParse; pSubParse->db = db; pSubParse->pTriggerTab = pTab; pSubParse->pToplevel = pTop; pSubParse->zAuthContext = pTrigger->zName; pSubParse->eTriggerOp = pTrigger->op; pSubParse->nQueryLoop = pParse->nQueryLoop; v = sqlite3GetVdbe(pSubParse); if( v ){ VdbeComment((v, "Start: %s.%s (%s %s%s%s ON %s)", pTrigger->zName, onErrorText(orconf), (pTrigger->tr_tm==TRIGGER_BEFORE ? "BEFORE" : "AFTER"), (pTrigger->op==TK_UPDATE ? "UPDATE" : ""), (pTrigger->op==TK_INSERT ? "INSERT" : ""), (pTrigger->op==TK_DELETE ? "DELETE" : ""), pTab->zName )); #ifndef SQLITE_OMIT_TRACE sqlite3VdbeChangeP4(v, -1, sqlite3MPrintf(db, "-- TRIGGER %s", pTrigger->zName), P4_DYNAMIC ); #endif /* If one was specified, code the WHEN clause. If it evaluates to false ** (or NULL) the sub-vdbe is immediately halted by jumping to the ** OP_Halt inserted at the end of the program. */ if( pTrigger->pWhen ){ pWhen = sqlite3ExprDup(db, pTrigger->pWhen, 0); if( SQLITE_OK==sqlite3ResolveExprNames(&sNC, pWhen) && db->mallocFailed==0 ){ iEndTrigger = sqlite3VdbeMakeLabel(v); sqlite3ExprIfFalse(pSubParse, pWhen, iEndTrigger, SQLITE_JUMPIFNULL); } sqlite3ExprDelete(db, pWhen); } /* Code the trigger program into the sub-vdbe. */ codeTriggerProgram(pSubParse, pTrigger->step_list, orconf); /* Insert an OP_Halt at the end of the sub-program. */ if( iEndTrigger ){ sqlite3VdbeResolveLabel(v, iEndTrigger); } sqlite3VdbeAddOp0(v, OP_Halt); VdbeComment((v, "End: %s.%s", pTrigger->zName, onErrorText(orconf))); transferParseError(pParse, pSubParse); if( db->mallocFailed==0 ){ pProgram->aOp = sqlite3VdbeTakeOpArray(v, &pProgram->nOp, &pTop->nMaxArg); } pProgram->nMem = pSubParse->nMem; pProgram->nCsr = pSubParse->nTab; pProgram->nOnce = pSubParse->nOnce; pProgram->token = (void *)pTrigger; pPrg->aColmask[0] = pSubParse->oldmask; pPrg->aColmask[1] = pSubParse->newmask; sqlite3VdbeDelete(v); } assert( !pSubParse->pAinc && !pSubParse->pZombieTab ); assert( !pSubParse->pTriggerPrg && !pSubParse->nMaxArg ); sqlite3StackFree(db, pSubParse); return pPrg; }
/* ** 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; }