+/*
+ * User-variables related functions
+ */
+/* for VM variables */
+XBT_PUBLIC(void) TRACE_vm_variable_declare (const char *variable);
+XBT_PUBLIC(void) TRACE_vm_variable_declare_with_color (const char *variable, const char *color);
+XBT_PUBLIC(void) TRACE_vm_variable_set (const char *vm, const char *variable, double value);
+XBT_PUBLIC(void) TRACE_vm_variable_add (const char *vm, const char *variable, double value);
+XBT_PUBLIC(void) TRACE_vm_variable_sub (const char *vm, const char *variable, double value);
+XBT_PUBLIC(void) TRACE_vm_variable_set_with_time (double time, const char *vm, const char *variable, double value);
+XBT_PUBLIC(void) TRACE_vm_variable_add_with_time (double time, const char *vm, const char *variable, double value);
+XBT_PUBLIC(void) TRACE_vm_variable_sub_with_time (double time, const char *vm, const char *variable, double value);
+XBT_PUBLIC(xbt_dynar_t) TRACE_get_vm_variables (void);
+
+
+/* for host variables */
+XBT_PUBLIC(void) TRACE_host_variable_declare (const char *variable);
+XBT_PUBLIC(void) TRACE_host_variable_declare_with_color (const char *variable, const char *color);
+XBT_PUBLIC(void) TRACE_host_variable_set (const char *host, const char *variable, double value);
+XBT_PUBLIC(void) TRACE_host_variable_add (const char *host, const char *variable, double value);
+XBT_PUBLIC(void) TRACE_host_variable_sub (const char *host, const char *variable, double value);
+XBT_PUBLIC(void) TRACE_host_variable_set_with_time (double time, const char *host, const char *variable, double value);
+XBT_PUBLIC(void) TRACE_host_variable_add_with_time (double time, const char *host, const char *variable, double value);
+XBT_PUBLIC(void) TRACE_host_variable_sub_with_time (double time, const char *host, const char *variable, double value);
+XBT_PUBLIC(xbt_dynar_t) TRACE_get_host_variables (void);
+
+/* for link variables */
+XBT_PUBLIC(void) TRACE_link_variable_declare (const char *var);
+XBT_PUBLIC(void) TRACE_link_variable_declare_with_color (const char *var, const char *color);
+XBT_PUBLIC(void) TRACE_link_variable_set (const char *link, const char *variable, double value);
+XBT_PUBLIC(void) TRACE_link_variable_add (const char *link, const char *variable, double value);
+XBT_PUBLIC(void) TRACE_link_variable_sub (const char *link, const char *variable, double value);
+XBT_PUBLIC(void) TRACE_link_variable_set_with_time (double time, const char *link, const char *variable, double value);
+XBT_PUBLIC(void) TRACE_link_variable_add_with_time (double time, const char *link, const char *variable, double value);
+XBT_PUBLIC(void) TRACE_link_variable_sub_with_time (double time, const char *link, const char *variable, double value);
+
+/* for link variables, but with src and dst used for get_route */
+XBT_PUBLIC(void) TRACE_link_srcdst_variable_set (const char *src, const char *dst, const char *variable, double value);
+XBT_PUBLIC(void) TRACE_link_srcdst_variable_add (const char *src, const char *dst, const char *variable, double value);
+XBT_PUBLIC(void) TRACE_link_srcdst_variable_sub (const char *src, const char *dst, const char *variable, double value);
+XBT_PUBLIC(void) TRACE_link_srcdst_variable_set_with_time (double time, const char *src, const char *dst, const char *variable, double value);
+XBT_PUBLIC(void) TRACE_link_srcdst_variable_add_with_time (double time, const char *src, const char *dst, const char *variable, double value);
+XBT_PUBLIC(void) TRACE_link_srcdst_variable_sub_with_time (double time, const char *src, const char *dst, const char *variable, double value);
+XBT_PUBLIC(xbt_dynar_t) TRACE_get_link_variables (void);
+XBT_PUBLIC(void) TRACE_host_state_declare (const char *state);
+XBT_PUBLIC(void) TRACE_host_state_declare_value (const char *state, const char *value, const char *color);
+XBT_PUBLIC(void) TRACE_host_set_state (const char *host, const char *state, const char *value);
+XBT_PUBLIC(void) TRACE_host_push_state (const char *host, const char *state, const char *value);
+XBT_PUBLIC(void) TRACE_host_pop_state (const char *host, const char *state);
+XBT_PUBLIC(void) TRACE_host_reset_state (const char *host, const char *state);
+
+/* for creating graph configuration files for Viva by hand */
+XBT_PUBLIC(xbt_dynar_t) TRACE_get_node_types (void);
+XBT_PUBLIC(xbt_dynar_t) TRACE_get_edge_types (void);
+XBT_PUBLIC(void) TRACE_pause (void);
+XBT_PUBLIC(void) TRACE_resume (void);