На самом деле это хуже, я поменял управление поведением do между случаями входа и выхода. Учитывая этот конечный автомат (переходы от состояния к самому себе являются внутренними): 
and the main
int main()
{
MM mm;
mm.create();
cout
Compilation (without defining VERBOSE_STATE_MACHINE) and execution :
pi@raspberrypi:~/sm/src $ g++ -Wall -g MM.cpp mmain.cpp
pi@raspberrypi:~/sm/src $ ./a.out
a entry
fire taa
a do
taa
fire tab
a do
a exit
tab expr
b entry
fire tbb
b do
tbb
fire tba
b do
b exit
tba expr
a entry
fire tdone
a do
a exit
tdone
pi@raspberrypi:~/sm/src $
So the do behavior is executed for an internal transition, wrongly when exiting a state, and is missing when entering in a state.
Note the state machine generator is the plug-out and its definition is part of BoUML delivery through the project sm_generator, it is implemented in C++ (not in Java). So you can load the project sm_generator, save-as it where you have the write permission, correct it, generate the C++ code, compile it and replace the official generator with your new version or declare your new plug-out and associate it to the state machine to have it in the menus.
I modified my state machine generator, the previous time was in 2011!
The do behavior is not anymore executed when exiting the state including through a self external transition, it is now executed after the possible do entry. I also do it after the possible transition behavior of a self internal transition, rather than before, that avoid two consecutive executions without nothing between in case the transition has a behavior.
Note it was already possible to execute the possible do behavior of the current state through the operation doActivity defined on the class associated to the machine. That allows to do it between transition firings.
With the previous state machine a little modified to add a self external transition :
введите описание изображения здесь
и что main
#include "MM.h"
#include <iostream>
using namespace std;
int main()
{
MM mm;
mm.create();
cout << endl << "fire taa" << endl;
mm.taa();
cout << endl << "fire ta_a" << endl;
mm.ta_a();
cout << endl << "fire tab" << endl;
mm.tab();
cout << endl << "fire tbb" << endl;
mm.tbb();
cout << endl << "fire tba" << endl;
mm.tba();
cout << endl << "fire tdone" << endl;
mm.tdone();
}
Компиляция (без определения VERBOSE_STATE_MACHINE ) и выполнение:
pi@raspberrypi:~/sm/src $ g++ -Wall MM.cpp mmain.cpp
pi@raspberrypi:~/sm/src $ ./a.out
a entry
a do
fire taa
taa expr
a do
fire ta_a
a exit
ta_a expr
a entry
a do
fire tab
a exit
tab expr
b entry
b do
fire tbb
tbb expr
b do
fire tba
b exit
tba expr
a entry
a do
fire tdone
a exit
tdone expr
pi@raspberrypi:~/sm/src $