Use sqlite3.c in all platforms

example/extension/extension.go

@@ -11,7 +11,7 @@ func main() {
 	sql.Register("sqlite3_with_extensions",
 		&sqlite3.SQLiteDriver{
 			Extensions: []string{
-				"sqlite3_mod_regexp.dll",
+				"sqlite3_mod_regexp",
 			},
 		})
 

example/extension/sqlite3_mod_regexp.c

@@ -1,4 +1,4 @@
-#include <regex.h>
+#include <pcre.h>
 #include <string.h>
 #include <stdio.h>
 #include <sqlite3ext.h>
@@ -21,7 +21,11 @@ static void regexp_func(sqlite3_context *context, int argc, sqlite3_value **argv
     sqlite3_result_int(context, 1);
   }
 }
-__declspec(dllexport) int sqlite3_extension_init(sqlite3 *db, char **errmsg, const sqlite3_api_routines *api) {
+
+#ifdef _WIN32
+__declspec(dllexport)
+#endif
+int sqlite3_extension_init(sqlite3 *db, char **errmsg, const sqlite3_api_routines *api) {
   SQLITE_EXTENSION_INIT2(api);
   return sqlite3_create_function(db, "regexp", 2, SQLITE_UTF8, (void*)db, regexp_func, NULL, NULL);
 }