[Phase 1 state machines] Add a protected function for getting the state

[bocchino]

In Phase 1 state machines, the state machine instance variables are private in the auto-generated component base class. This is so that the implementation can't access the state machine instance directly; it has to go through the interface provided by the component base class. However, the implementation needs to be able to query the state of the state machine. So we need to add a protected function for getting the state to the component interface.

• Revise code gen
• Update unit tests

[bocchino]

The state getter function should work the same way as it does for Phase 2 state machines. The current documentation is here:

https://github.com/bocchino/fprime/blob/fpp-state-machines/docs/Design/state-machines.md#541-implemented-functions

The current implementation is here:

fpp/compiler/lib/src/main/scala/codegen/CppWriter/ComponentCppWriter/ComponentInternalStateMachines.scala

Lines 513 to 525 in d5af763

	private def getStateGetterFunction(smi: StateMachineInstance): CppDoc.Class.Member = {
	val smiName = smi.getName
	val smName = writeStateMachineImplType(smi.symbol)
	functionClassMember(
	Some(s"Get the state of state machine instance $smiName"),
	s"${smiName}_getState",
	Nil,
	CppDoc.Type(s"$smName::State", Some(s"$componentClassName::$smName::State")),
	lines(s"return this->m_stateMachine_$smiName.getState();"),
	CppDoc.Function.NonSV,
	CppDoc.Function.Const
	)
	}

[bocchino]

We should add the new function here:

fpp/compiler/lib/src/main/scala/codegen/CppWriter/ComponentCppWriter/ComponentStateMachines.scala

Lines 26 to 31 in d70098f

	def getFunctionMembers: List[CppDoc.Class.Member] = {
	List.concat(
	getOverflowHooks,
	getSignalSendMember
	)
	}

[bocchino]

The unit tests to update are here:

https://github.com/nasa/fpp/tree/main/compiler/tools/fpp-to-cpp/test/component/base

./run in that directory will run the tests (you have to run ./install in fpp/compiler/tools first to install the tools). ./update-ref in that directory will update the reference output. A good procedure is

1. Make changes to the code generator.
2. Run ./update-ref
3. Run git diff to make sure that everything looks good.
4. Commit the changes.