smccgenerator.java

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

            // There is only one guard. Does this guard have a
            // condition.
            if (condition.length() == 0)
            {
                // Actually, this is a plain, old, vaniila
                // transition.
                indent2 = _indent + "    ";
            }
            else
            {
                // Yes, there is a condition.
                _source.print(_indent);
                _source.print("    if (");
                _source.print(condition);
                _source.println(") {");
                indent2 = _indent + "        ";
            }
        }

        // Now that the necessary conditions are in place, it's
        // time to dump out the transitions actions. First, do
        // the proper handling of the state change. If this
        // transition has no actions, then set the end state
        // immediately. Otherwise, unset the current state so
        // that if an action tries to issue a transition, it will
        // fail.
        if (actions.size() == 0 && endStateName.length() > 0)
        {
            fqEndStateName = endStateName;
        }
        else if (actions.size() > 0)
        {
            // Save away the current state if this is a loopback
            // transition. Storing current state allows the
            // current to be cleared before any actions are
            // executed. Remember: actions are not allowed to
            // issue transitions and clearing the current state
            // prevents them from doing so.
            if (loopbackFlag == true)
            {
                fqEndStateName = "EndStateName";

                // Generate this declaration only if this
                // transition has multiple guards. If this
                // is the only guard, then this local variable
                // declaration will appear after the first
                // control statement - which is an ANSI C
                // syntax error.
                // If there is only one guard, then this code
                // is generated by visit(SmcTransition) before
                // the debug code is generated.
                // If there are multiple guards, then this code
                // appears at the start of an if, else if or else
                // code block which is acceptable ANSI C.
                if (_guardCount > 1)
                {
                    _source.print(indent2);
                    _source.print("const struct ");
                    _source.print(context);
                    _source.print("State* ");
                    _source.print(fqEndStateName);
                    _source.println(" = getState(fsm);");
                    _source.println();
                }
            }
            else
            {
                fqEndStateName = endStateName;
            }
        }

        // Decide if runtime loopback checking must be done.
        if (defaultFlag == true &&
            transType == Smc.TRANS_SET &&
            loopbackFlag == false)
        {
            _source.print(_indent);
            _source.print(
                "    if (strcmp(getName(getState(fsm)), ");
            _source.print("getName(");
            _source.print(endStateName);
            _source.println(")) == 0) {");
            _source.print(_indent);
            _source.println("        loopbackFlag = 1;");
            _source.print(_indent);
            _source.println("    }");
        }

        // Before doing anything else, perform the current
        // state's exit actions.
        // v. 1.0, beta 3: Not any more. The exit actions are
        // executed only if 1) this is a standard, non-loopback
        // transition or a pop transition.
        if (transType == Smc.TRANS_POP ||
            loopbackFlag == false)
        {
            indent4 = indent2;

            // If this is a non-loopback, generic transition,
            // do runtime loopback checking.
            if (transType == Smc.TRANS_SET &&
                defaultFlag == true)
            {
                indent4 = indent2 + "    ";
                _source.print(indent2);
                _source.println(
                    "if (loopbackFlag == 0) {");
            }

            _source.print(indent4);
            _source.println(
                "EXIT_STATE(getState(fsm));");

            if (transType == Smc.TRANS_SET &&
                defaultFlag == true)
            {
                _source.print(indent2);
                _source.println("}");
            }
        }

        if (actions.isEmpty() == false)
        {
            // Now that we are in the transition, clear the
            // current state.
            _source.print(indent2);
            _source.println("clearState(fsm);");
        }

        // Dump out this transition's actions.
        if (actions.isEmpty() == true)
        {
            if (condition.length() > 0)
            {
                _source.print(indent2);
                _source.println("/* No actions. */");
            }
        }
        else
        {
            indent4 = _indent;
            _indent = indent2;
            for (SmcAction action: actions)
            {
                action.accept(this);
            }
            _indent = indent4;
        }
        indent3 = indent2;

        // Print the setState() call, if necessary. Do NOT
        // generate the set state if:
        // 1. The transition has no actions AND is a loopback OR
        // 2. This is a push or pop transition.
        if (transType == Smc.TRANS_SET &&
            (actions.isEmpty() == false ||
             loopbackFlag == false))
        {
            _source.print(indent3);
            _source.print("setState(fsm, ");
            _source.print(fqEndStateName);
            _source.println(");");
        }
        else if (transType == Smc.TRANS_PUSH)
        {
            // Set the end state so that it can be pushed
            // onto the state stack. But only do so if a clear
            // state was done.
            if (loopbackFlag == false ||
                actions.isEmpty() == false)
            {
                _source.print(indent3);
                _source.print("setState(fsm, ");
                _source.print(fqEndStateName);
                _source.println(");");
            }

            // Before doing the push, execute the end state's
            // entry actions (if any) if this is not a loopback.
            if (loopbackFlag == false)
            {
                if (defaultFlag == true)
                {
                    indent4 = indent3 + "    ";

                    _source.println();
                    _source.print(indent3);
                    _source.println("if (loopbackFlag == 0) {");
                }
                else
                {
                    indent4 = indent3;
                }

                _source.print(indent4);
                _source.println(
                    "ENTRY_STATE(getState(fsm));");

                if (defaultFlag == true)
                {
                    _source.print(indent3);
                    _source.println("}");
                }
            }

            _source.print(indent3);
            _source.print("pushState(fsm, ");
            _source.print(pushStateName);
            _source.println(");");
        }
        else if (transType == Smc.TRANS_POP)
        {
            _source.print(indent3);
            _source.println("popState(fsm);");
        }

        // Perform the new state's entry actions.
        // v. 1.0, beta 3: Not any more. The entry actions are
        // executed only if 1) this is a standard, non-loopback
        // transition or a push transition.
        if ((transType == Smc.TRANS_SET &&
             loopbackFlag == false) ||
             transType == Smc.TRANS_PUSH)
        {
            // If this is a non-loopback, generic transition,
            // do runtime loopback checking.
            if (transType == Smc.TRANS_SET &&
                defaultFlag == true)
            {
                indent4 = indent2 + "    ";

                _source.print(indent2);
                _source.println("if (loopbackFlag == 0) {");
            }
            else
            {
                indent4 = indent2;
            }

            _source.print(indent4);
            _source.println(
                "ENTRY_STATE(getState(fsm));");

            if (transType == Smc.TRANS_SET &&
                defaultFlag == true)
            {
                _source.print(indent2);
                _source.println("}");
            }
        }

        // If there is a transition associated with the pop, then
        // issue that transition here.
        if (transType == Smc.TRANS_POP &&
            endStateName.equals(NIL_STATE) == false &&
            endStateName.length() > 0)
        {
            String popArgs = guard.getPopArgs();

            _source.print(indent2);
            _source.print(context);
            _source.print("Context_");
            _source.print(endStateName);
            _source.print("(fsm");

            // Output any and all pop arguments.
            if (popArgs.length() > 0)
            {
                _source.print(", ");
                _source.print(popArgs);
            }
            _source.println(");");
        }

        // If this is a guarded transition, it will be necessary
        // to close off the "if" body. DON'T PRINT A NEW LINE!
        // Why? Because an "else" or "else if" may follow and we
        // won't know until we go back to the transition source
        // generator whether all clauses have been done.
        if (_guardCount > 1)
        {
            _source.print(_indent);
            _source.print("    }");
        }

        return;
    } // end of visit(SmcGuard)

    public void visit(SmcAction action)
    {
        String name = action.getName();

        // Need to distinguish between FSMContext actions and
        // application class actions. If the action is
        // "emptyStateStack", then pass it to the context.
        // Otherwise, let the application class handle it.
        _source.print(_indent);
        if (name.equals("emptyStateStack") == true)
        {
            _source.print(name);
            _source.print("(fsm");
        }
        else
        {
            _source.print(_context);
            _source.print("_");
            _source.print(name);
            _source.print("(ctxt");
        }

        for (String arg: action.getArguments())
        {
            if (arg.equals("") == false)
            {
                _source.print(", ");
                _source.print(arg);
            }
        }

        _source.println(");");

        return;
    } // end of visit(SmcAction)

    public void visit(SmcParameter parameter)
    {
        _source.print(parameter.getType());
        _source.print(" ");
        _source.print(parameter.getName());

        return;
    } // end of visit(SmcParameter)

    // Scope the state name. If the state is unscoped, then
    // return "<mapName>.<stateName>". If the state named
    // contains the scope string "::", replace that with a "_".
    protected String scopeStateName(String stateName,
                                    String mapName)
    {
        int index;
        StringWriter retval = new StringWriter();

        index = stateName.indexOf("::");
        if (index < 0)
        {
            retval.write(mapName);
            retval.write("_");
            retval.write(stateName);
        }
        else
        {
            retval.write(stateName.substring(0, index));
            retval.write('_');
            retval.write(stateName.substring(index + 2));
        }

        return (retval.toString());
    } // end of scopeStateName(String, String)

//---------------------------------------------------------------
// Member data
//
    String _context;
} // end of class SmcCGenerator

//
// CHANGE LOG
// $Log: SmcCGenerator.java,v $
// Revision 1.15  2008/03/21 14:03:16  fperrad
// refactor : move from the main file Smc.java to each language generator the following data :
//  - the default file name suffix,
//  - the file name format for the generated SMC files
//
// Revision 1.14  2008/02/08 08:46:02  fperrad
// C : optimize footprint when no Entry action or no Exit action
//
// Revision 1.13  2008/02/04 10:26:51  fperrad
// Don't generate cuddled else
//
// Revision 1.12  2007/12/28 12:34:41  cwrapp
// Version 5.0.1 check-in.
//
// Revision 1.11  2007/11/19 18:48:54  fperrad
// fix C generation :
// default state must be always 'DefaultState' (previously 'Default')
//
// Revision 1.10  2007/08/05 14:50:54  cwrapp
// Version 5.0.1 check-in. See net/sf/smc/CODE_README.txt for more information.
//
// Revision 1.9  2007/08/05 14:26:25  cwrapp
// Version 5.0.1 check-in. See net/sf/smc/CODE_README.txt for more informaiton.
//
// Revision 1.8  2007/07/16 06:13:21  fperrad
// + Added the generation of a DO NOT EDIT comment
//
// Revision 1.7  2007/02/21 13:53:57  cwrapp
// Moved Java code to release 1.5.0
//
// Revision 1.6  2007/01/15 00:23:50  cwrapp
// Release 4.4.0 initial commit.
//
// Revision 1.5  2006/09/16 15:04:28  cwrapp
// Initial v. 4.3.3 check-in.
//
// Revision 1.4  2006/07/11 18:11:41  cwrapp
// Added support for new -headerd command line option.
//
// Revision 1.3  2006/04/22 12:45:26  cwrapp
// Version 4.3.1
//
// Revision 1.2  2005/11/07 19:34:54  cwrapp
// Changes in release 4.3.0:
// New features:
//
// + Added -reflect option for Java, C#, VB.Net and Tcl code
//   generation. When used, allows applications to query a state
//   about its supported transitions. Returns a list of transition
//   names. This feature is useful to GUI developers who want to
//   enable/disable features based on the current state. See
//   Programmer's Manual section 11: On Reflection for more
//   information.
//
// + Updated LICENSE.txt with a missing final paragraph which allows
//   MPL 1.1 covered code to work with the GNU GPL.
//
// + Added a Maven plug-in and an ant task to a new tools directory.
//   Added Eiten Suez's SMC tutorial (in PDF) to a new docs
//   directory.
//
// Fixed the following bugs:
//
// + (GraphViz) DOT file generation did not properly escape
//   double quotes appearing in transition guards. This has been
//   corrected.
//
// + A note: the SMC FAQ incorrectly stated that C/C++ generated
//   code is thread safe. This is wrong. C/C++ generated is
//   certainly *not* thread safe. Multi-threaded C/C++ applications
//   are required to synchronize access to the FSM to allow for
//   correct performance.
//
// + (Java) The generated getState() method is now public.
//
// Revision 1.1  2005/06/16 18:11:01  fperrad
// Added C, Perl & Ruby generators.
//
//