Refactor: lib/services: ensure *.h declare externally hidden functions

...following the precedent of {upstart,systemd}.h.  Note also that
since hardening-related commit 658fff9 [$LD -z now], it's even more
desirable to limit "symbol smog" as much as possible and symbols only
used within the library like these are trivially expendable (assuming
suitable toolchain).

As we use G_GNU_C_INTERNAL macro from glib2, we should care to require
at least that version that introduced it, i.e., 2.6 per documentation.

lib/services/pcmk-dbus.h

@@ -14,19 +14,32 @@
 #    define DBUS_TIMEOUT_USE_DEFAULT -1
 #  endif
 
+G_GNUC_INTERNAL
 DBusConnection *pcmk_dbus_connect(void);
+
+G_GNUC_INTERNAL
 void pcmk_dbus_connection_setup_with_select(DBusConnection *c);
+
+G_GNUC_INTERNAL
 void pcmk_dbus_disconnect(DBusConnection *connection);
 
+G_GNUC_INTERNAL
 DBusPendingCall *pcmk_dbus_send(DBusMessage *msg, DBusConnection *connection,
                     void(*done)(DBusPendingCall *pending, void *user_data), void *user_data, int timeout);
+
+G_GNUC_INTERNAL
 DBusMessage *pcmk_dbus_send_recv(DBusMessage *msg, DBusConnection *connection, DBusError *error, int timeout);
+
+G_GNUC_INTERNAL
 bool pcmk_dbus_type_check(DBusMessage *msg, DBusMessageIter *field, int expected, const char *function, int line);
+
+G_GNUC_INTERNAL
 char *pcmk_dbus_get_property(
     DBusConnection *connection, const char *target, const char *obj, const gchar * iface, const char *name,
     void (*callback)(const char *name, const char *value, void *userdata), void *userdata,
     DBusPendingCall **pending, int timeout);
 
+G_GNUC_INTERNAL
 bool pcmk_dbus_find_error(DBusPendingCall *pending, DBusMessage *reply,
                           DBusError *error);
 

lib/services/services_private.h

@@ -45,30 +45,44 @@ struct svc_action_private_s {
 #endif
 };
 
+G_GNUC_INTERNAL
 GList *services_os_get_directory_list(const char *root, gboolean files, gboolean executable);
 
+G_GNUC_INTERNAL
 gboolean services_os_action_execute(svc_action_t * op, gboolean synchronous);
 
+G_GNUC_INTERNAL
 GList *resources_os_list_lsb_agents(void);
 
+G_GNUC_INTERNAL
 GList *resources_os_list_ocf_providers(void);
 
+G_GNUC_INTERNAL
 GList *resources_os_list_ocf_agents(const char *provider);
 
+G_GNUC_INTERNAL
 GList *resources_os_list_nagios_agents(void);
 
+G_GNUC_INTERNAL
 gboolean cancel_recurring_action(svc_action_t * op);
 
+G_GNUC_INTERNAL
 gboolean recurring_action_timer(gpointer data);
+
+G_GNUC_INTERNAL
 gboolean operation_finalize(svc_action_t * op);
 
+G_GNUC_INTERNAL
 void services_add_inflight_op(svc_action_t *op);
 
+G_GNUC_INTERNAL
 void handle_blocked_ops(void);
 
+G_GNUC_INTERNAL
 gboolean is_op_blocked(const char *rsc);
 
 #if SUPPORT_DBUS
+G_GNUC_INTERNAL
 void services_set_op_pending(svc_action_t *op, DBusPendingCall *pending);
 #endif
 

pacemaker.spec.in

@@ -190,7 +190,9 @@ BuildRequires: coreutils findutils grep sed
 
 # Required for core functionality
 BuildRequires: automake autoconf libtool pkgconfig libtool-ltdl-devel
-BuildRequires: pkgconfig(glib-2.0) libxml2-devel libxslt-devel libuuid-devel
+## version lower bound for: G_GNUC_INTERNAL
+BuildRequires: pkgconfig(glib-2.0) >= 2.6
+BuildRequires: libxml2-devel libxslt-devel libuuid-devel
 BuildRequires: bzip2-devel pam-devel
 
 # Required for agent_config.h which specifies the correct scratch directory