c_glib: an abstract base class is not generated

thrift -r --gen c_glib tutorial.thrift

/**
 * Autogenerated by Thrift Compiler (0.9.1)
 *
 * DO NOT EDIT UNLESS YOU ARE SURE THAT YOU KNOW WHAT YOU ARE DOING
 *  @generated
 */
#ifndef CALCULATOR_H
#define CALCULATOR_H

#include "tutorial_types.h"
#include "shared_service.h"

/* Calculator service interface */
typedef struct _CalculatorIf CalculatorIf;  /* dummy object */

struct _CalculatorIfInterface
{
  GTypeInterface parent;

  gboolean (*ping) (CalculatorIf *iface, GError **error);
  gboolean (*add) (CalculatorIf *iface, gint32* _return, const gint32 num1, const gint32 num2, GError **error);
  gboolean (*calculate) (CalculatorIf *iface, gint32* _return, const gint32 logid, const Work * w, InvalidOperation ** ouch, GError **error);
  gboolean (*zip) (CalculatorIf *iface, GError **error);
};
typedef struct _CalculatorIfInterface CalculatorIfInterface;

GType calculator_if_get_type (void);
#define TYPE_CALCULATOR_IF (calculator_if_get_type())
#define CALCULATOR_IF(obj) (G_TYPE_CHECK_INSTANCE_CAST ((obj), TYPE_CALCULATOR_IF, CalculatorIf))
#define IS_CALCULATOR_IF(obj) (G_TYPE_CHECK_INSTANCE_TYPE ((obj), TYPE_CALCULATOR_IF))
#define CALCULATOR_IF_GET_INTERFACE(inst) (G_TYPE_INSTANCE_GET_INTERFACE ((inst), TYPE_CALCULATOR_IF, CalculatorIfInterface))

gboolean calculator_if_ping (CalculatorIf *iface, GError **error);
gboolean calculator_if_add (CalculatorIf *iface, gint32* _return, const gint32 num1, const gint32 num2, GError **error);
gboolean calculator_if_calculate (CalculatorIf *iface, gint32* _return, const gint32 logid, const Work * w, InvalidOperation ** ouch, GError **error);
gboolean calculator_if_zip (CalculatorIf *iface, GError **error);

/* Calculator service client */
struct _CalculatorClient
{
  GObject parent;

  ThriftProtocol *input_protocol;
  ThriftProtocol *output_protocol;
};
typedef struct _CalculatorClient CalculatorClient;

struct _CalculatorClientClass
{
  GObjectClass parent;
};
typedef struct _CalculatorClientClass CalculatorClientClass;

GType calculator_client_get_type (void);
#define TYPE_CALCULATOR_CLIENT (calculator_client_get_type())
#define CALCULATOR_CLIENT(obj) (G_TYPE_CHECK_INSTANCE_CAST ((obj), TYPE_CALCULATOR_CLIENT, CalculatorClient))
#define CALCULATOR_CLIENT_CLASS(c) (G_TYPE_CHECK_CLASS_CAST ((c), TYPE_CALCULATOR_CLIENT, CalculatorClientClass))
#define CALCULATOR_IS_CLIENT(obj) (G_TYPE_CHECK_INSTANCE_TYPE ((obj), TYPE_CALCULATOR_CLIENT))
#define CALCULATOR_IS_CLIENT_CLASS(c) (G_TYPE_CHECK_CLASS_TYPE ((c), TYPE_CALCULATOR_CLIENT))
#define CALCULATOR_CLIENT_GET_CLASS(obj) (G_TYPE_INSTANCE_GET_CLASS ((obj), TYPE_CALCULATOR_CLIENT, CalculatorClientClass))

gboolean calculator_client_ping (CalculatorIf * iface, GError ** error);
gboolean calculator_client_send_ping (CalculatorIf * iface, GError ** error);
gboolean calculator_client_recv_ping (CalculatorIf * iface, GError ** error);
gboolean calculator_client_add (CalculatorIf * iface, gint32* _return, const gint32 num1, const gint32 num2, GError ** error);
gboolean calculator_client_send_add (CalculatorIf * iface, const gint32 num1, const gint32 num2, GError ** error);
gboolean calculator_client_recv_add (CalculatorIf * iface, gint32* _return, GError ** error);
gboolean calculator_client_calculate (CalculatorIf * iface, gint32* _return, const gint32 logid, const Work * w, InvalidOperation ** ouch, GError ** error);
gboolean calculator_client_send_calculate (CalculatorIf * iface, const gint32 logid, const Work * w, GError ** error);
gboolean calculator_client_recv_calculate (CalculatorIf * iface, gint32* _return, InvalidOperation ** ouch, GError ** error);
gboolean calculator_client_zip (CalculatorIf * iface, GError ** error);
gboolean calculator_client_send_zip (CalculatorIf * iface, GError ** error);
void calculator_client_set_property (GObject *object, guint property_id, const GValue *value, GParamSpec *pspec);
void calculator_client_get_property (GObject *object, guint property_id, GValue *value, GParamSpec *pspec);

#endif /* CALCULATOR_H */

$ grep -iR handler gen-c_glib
$