how to load extensions in sqlite3? - c

Question

I'm trying to load regexp.c extension in order to add REGEXP operator into sqlite. What I have done:
Download sqlite3 amalgamation file
Found regexp.c loadable extension
Created test project in VS2015
#include <stdio.h>
#include "stdafx.h"
#include "sqlite3.h"
const char* SQL = "SELECT load_extension('sqlite3.obj', 'sqlite3_regexp_init');";
int main(int argc, char **argv) {
sqlite3 *db = 0; // the hande of connection object to db
char *err = 0;
char *errMsg = "unable to load extension";
// open connection
if (sqlite3_open("my_cosy_database.dblite", &db))
fprintf(stderr, "Error during opening/creation DB: %s\n", sqlite3_errmsg(db));
/*else if (sqlite3_db_config(db, SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION, 1, 0))
{
fprintf(stderr, "Cannot enable extensions loading: %s\n", sqlite3_errmsg(db));
}*/
else if (sqlite3_enable_load_extension(db, 1))
{
fprintf(stderr, "Cannot enable extensions loading: %s\n", sqlite3_errmsg(db));
}
// execute SQL
else if (sqlite3_load_extension(db, "sqlite3.obj", "sqlite3_regexp_init", &errMsg))
{
fprintf(stderr, "Cannot load sqlite3_regexp_init extension: %s\n", sqlite3_errmsg(db));
}
else if (sqlite3_exec(db, SQL, callback, 0, &err))
{
fprintf(stderr, "Ошибка SQL: %sn", err);
sqlite3_free(err);
}
// close connection
sqlite3_close(db);
return 0;
}
Official documentation says: "For security reasons, extension loading is turned off by default. In order to use either the C-language or SQL extension loading functions, one must first enable extension loading using the sqlite3_db_config(db,SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION,1,NULL) C-language API in your application." So this is what I've done. The problem is that I got every time sqlite3_load_extension or sqlite3_exec is called. The same problem appears with commented sqlite3_enable_load_extension and uncommented sqlite3_db_config. I have no idea what causes this exception and there is no clear example of C api usage (even in 'Using Sqlite' book). One thing i could find out is the statement which causes this exception: "(pCtx->pFunc->xSFunc)(pCtx, pCtx->argc, pCtx->argv);/ IMP: R-24505-23230 */" in the SQLITE_PRIVATE int sqlite3VdbeExec(Vdbe p / The VDBE */).
So please, help.