smccgenerator.java

SMC takes a state machine stored in a .sm file and generates a State pattern in twelve programming l

                    _source.print(stateName);
                    _source.print("_");
                    _source.print(transName);
                    _source.print(" ");
                    _source.print(mapName);
                    _source.print("_DefaultState_");
                    _source.println(transName);
                }

                _source.print("#undef ");
                _source.print(mapName);
                _source.print("_DefaultState_");
                _source.println(transName);

                trans.accept(this);
            }
        }

        // Have each state now generate its code.
        for (SmcState state: map.getStates())
        {
            stateName = state.getInstanceName();

            state.accept(this);

            _source.println();
            _source.print("const struct ");
            _source.print(context);
            _source.print("State ");
            _source.print(mapName);
            _source.print("_");
            _source.print(stateName);
            _source.print(" = { POPULATE_STATE(");
            _source.print(mapName);
            _source.print("_");
            _source.print(stateName);
            _source.print("), \"");
            _source.print(mapName);
            _source.print("_");
            _source.print(stateName);
            _source.print("\", ");
            _source.print(
                Integer.toString(map.getNextStateId()));
            _source.println(" };");
        }

        return;
    } // end of visit(SmcMap)

    public void visit(SmcState state)
    {
        SmcMap map = state.getMap();
        String packageName = map.getFSM().getPackage();
        String context = map.getFSM().getContext();
        String mapName = map.getName();
        String instanceName = state.getInstanceName();
        String indent2;
        List<SmcAction> actions;

        // If a package has been specified,
        if (packageName != null && packageName.length() > 0)
        {
            context = packageName + "_" + context;
            mapName = packageName + "_" + mapName;
        }

        _context = context;

        // Add the Entry() and Exit() methods if this state
        // defines them.
        actions = state.getEntryActions();
        if (actions != null && actions.isEmpty() == false)
        {
            _source.println();
            _source.print("#undef ");
            _source.print(mapName);
            _source.print("_");
            _source.print(instanceName);
            _source.println("_Entry");
            _source.print("void ");
            _source.print(mapName);
            _source.print("_");
            _source.print(instanceName);
            _source.print("_Entry(struct ");
            _source.print(context);
            _source.println("Context *fsm)");
            _source.println("{");

            // Declare the "ctxt" local variable.
            _source.print("    struct ");
            _source.print(context);
            _source.println(" *ctxt = getOwner(fsm);");
            _source.println();

            // Generate the actions associated with this code.
            indent2 = _indent;
            _indent = _indent + "    ";
            for (SmcAction action: actions)
            {
                action.accept(this);
            }
            _indent = indent2;

            // End the Entry() method.
            _source.println("}");
        }

        actions = state.getExitActions();
        if (actions != null && actions.isEmpty() == false)
        {
            _source.println();
            _source.print("#undef ");
            _source.print(mapName);
            _source.print("_");
            _source.print(instanceName);
            _source.println("_Exit");
            _source.print("void ");
            _source.print(mapName);
            _source.print("_");
            _source.print(instanceName);
            _source.print("_Exit(struct ");
            _source.print(context);
            _source.println("Context *fsm)");
            _source.println("{");

            // Declare the "ctxt" local variable.
            _source.print("    struct ");
            _source.print(context);
            _source.println(" *ctxt = getOwner(fsm);");
            _source.println();

            // Generate the actions associated with this code.
            indent2 = _indent;
            _indent = _indent + "    ";
            for (SmcAction action: actions)
            {
                action.accept(this);
            }
            _indent = indent2;

            // End the Entry() method.
            _source.println("}");
        }

        // Have the transitions generate their code.
        for (SmcTransition transition: state.getTransitions())
        {
            transition.accept(this);
        }

        return;
    } // end of visit(SmcState)

    public void visit(SmcTransition transition)
    {
        SmcState state = transition.getState();
        SmcMap map = state.getMap();
        String packageName = map.getFSM().getPackage();
        String context = map.getFSM().getContext();
        String mapName = map.getName();
        String stateName = state.getInstanceName();
        String transName = transition.getName();
        boolean defaultFlag = false;
        boolean nullCondition = false;
        List<SmcGuard> guards = transition.getGuards();
        Iterator<SmcGuard> git;
        SmcGuard guard;

        // If a package has been specified,
        if (packageName != null && packageName.length() > 0)
        {
            context = packageName + "_" + context;
            mapName = packageName + "_" + mapName;
        }

        // Set a flag to denote if this is a Default state
        // transition.
        if (stateName.equals("DefaultState") == true)
        {
            // stateName = state.getClassName();
            defaultFlag = true;
        }

        if (defaultFlag == false)
        {
            _source.println();
            _source.print("#undef ");
            _source.print(mapName);
            _source.print("_");
            _source.print(stateName);
            _source.print("_");
            _source.println(transName);
        }

        _source.print("static void ");
        _source.print(mapName);
        _source.print("_");
        _source.print(stateName);
        _source.print("_");
        _source.print(transName);
        _source.print("(struct ");
        _source.print(context);
        _source.print("Context *fsm");

        // Add user-defined parameters.
        for (SmcParameter parameter: transition.getParameters())
        {
            _source.print(", ");
            parameter.accept(this);
        }

        _source.println(")");
        _source.println("{");

        // All transitions have a "ctxt" local variable.
        // 8/14/2003:
        // Do this only if there are any transition actions or
        // guard conditions which reference it.
        if (transition.hasCtxtReference() == true)
        {
            _source.print("    struct ");
            _source.print(context);
            _source.println("* ctxt = getOwner(fsm);");
        }

        if (defaultFlag == true)
        {
            _source.println("    int loopbackFlag = 0;");
        }

        // ANSI C requires all local variables be declared
        // at the code block's start before any control
        // statements. If this transition appears only once
        // in the state, has at least one action and it is a
        // loopback and debugging is on, then visit(SmcGuard)
        // will generate a local variable declaration after the
        // debug if clause - an ANSI syntax error.
        // So we need to check if this transition meets that
        // condition and generate the local variable declaration
        // here rather than in visit(SmcGuard).
        //
        // Note: when guard count is > 1, then the guard code
        // is placed into an if or else block - and so the
        // end state variable will appear at the start of that
        // block, nullifying the debug if clauses affect.
        _guardCount = guards.size();
        if (_guardCount == 1)
        {
            guard = (SmcGuard) guards.get(0);

            if (guard.getActions().isEmpty() == false &&
                isLoopback(guard.getTransType(),
                           stateName,
                           guard.getEndState()) == true)
            {
                _source.print("    const struct ");
                _source.print(context);
                _source.println(
                    "State* EndStateName = getState(fsm);");
            }
        }

        _source.println();

        // Print the transition to the verbose log.
        if (Smc.isDebug() == true)
        {
            Iterator<SmcParameter> pit;
            SmcParameter param;
            String sep;

            _source.println("    if (getDebugFlag(fsm) != 0) {");
            _source.print("        TRACE(\"TRANSITION   : ");
            _source.print(mapName);
            _source.print("_");
            _source.print(stateName);
            _source.print(".");
            _source.print(transName);
            _source.print("(");

            for (pit = transition.getParameters().iterator(),
                     sep = "";
                 pit.hasNext() == true;
                 sep = ", ")
            {
                param = pit.next();
                _source.print(sep);
                _source.print(param.getName());
            }

            _source.println(")\\n\\r\");");

            _source.println("    }");
        }

        // Loop through the guards and print each one.
        for (git = guards.iterator(), _guardIndex = 0;
             git.hasNext() == true;
             ++_guardIndex)
        {
            guard = git.next();

            // Count up the number of guards with no condition.
            if (guard.getCondition().length() == 0)
            {
                nullCondition = true;
            }

            guard.accept(this);
        }

        // If all guards have a condition, then create a final
        // "else" clause which passes control to the default
        // transition.
        if (_guardIndex > 0 && nullCondition == false)
        {
            // If there is only one transition definition, then
            // close off the guard.
            if (_guardCount == 1)
            {
                _source.println("    }");
            }

            _source.println("    else {");
            _source.print("        ");
            _source.print(mapName);
            _source.print("_DefaultState_");
            _source.print(transName);
            _source.print("(fsm");

            // Output user-defined parameters.
            for (SmcParameter param: transition.getParameters())
            {
                _source.print(", ");
                _source.print(param.getName());
            }
            _source.println(");");
            _source.println("    }");
        }
        else if (_guardCount > 1)
        {
            _source.println();
        }

        _source.println("}");

        return;
    } // end of visit(SmcTransition)

    public void visit(SmcGuard guard)
    {
        SmcTransition transition = guard.getTransition();
        SmcState state = transition.getState();
        SmcMap map = state.getMap();
        String packageName = map.getFSM().getPackage();
        String context = map.getFSM().getContext();
        String mapName = map.getName();
        String stateName = state.getInstanceName();
        int transType = guard.getTransType();
        boolean defaultFlag =
            stateName.equalsIgnoreCase("DefaultState");
        boolean loopbackFlag = false;
        String indent2;
        String indent3;
        String indent4 = "";
        String endStateName = guard.getEndState();
        String fqEndStateName = "";
        String pushStateName = guard.getPushState();
        String condition = guard.getCondition();
        List<SmcAction> actions = guard.getActions();

        // If a package has been specified,
        if (packageName != null && packageName.length() > 0)
        {
            context = packageName + "_" + context;
            mapName = packageName + "_" + mapName;
        }

        _context = context;

        // If this guard's end state is not of the form
        // "map::state", then prepend the map name to the state
        // name.
        // DON'T DO THIS IF THIS IS A POP TRANSITION!
        // The "state" is actually a transition name.
        if (transType != Smc.TRANS_POP &&
            endStateName.length () > 0 &&
            endStateName.equals(NIL_STATE) == false)
        {
            endStateName =
                "&" + scopeStateName(endStateName, mapName);
        }

        // Qualify the state and push state names as well.
        stateName = "&" + scopeStateName(stateName, mapName);
        pushStateName = scopeStateName(pushStateName, mapName);
        if (packageName != null && packageName.length() > 0)
        {
            pushStateName =
                "&" + packageName + "_" + pushStateName;
        }
        else
        {
            pushStateName = "&" + pushStateName;
        }

        loopbackFlag =
            isLoopback(transType, stateName, endStateName);

        // The guard code generation is a bit tricky. The first
        // question is how many guards are there? If there are
        // more than one, then we will need to generate the
        // proper "if-then-else" code.
        if (_guardCount > 1)
        {
            indent2 = _indent + "        ";

            // More than one guard. Is this the first guard?
            if (_guardIndex == 0 && condition.length() > 0)
            {
                // Yes, this is the first. This means an
                // "if" should be used for this condition.
                _source.print(_indent);
                _source.print("    if (");
                _source.print(condition);
                _source.println(") {");
            }
            else if (condition.length() > 0)
            {
                // No, this is not the first transition but it
                // does have a condition. Use an "else if" for
                // the condition.
                _source.println();
                _source.print(_indent);
                _source.print("    else if (");
                _source.print(condition);
                _source.println(") {");
            }
            else
            {
                // This is not the first transition and it has
                // no condition.
                _source.println();
                _source.print(_indent);
                _source.println("    else {");
            }
        }
        else
        {