Programming Project 3 GritVM Interpreter Solution

Description

Instructions

For Programming Project 3, you will be implementing an interpreter for a programming language called GritVM. Your GritVM will read in a file of code written in this specific GVM language, run the instructions, and be able to return the results held in the GritVM object’s memory. The GritVM has two variables that contain its memory: a NodeList that contains the instructions and a Vector that contains the data. There will also be a single variable called the accumulator. The accumulator stores the results of various operations as an intermediate. The accumulator is an implicit operand for all mathematical calculations.

Below is an example of some of your private members for the GritVM.

std::vector<long> dataMem; std::list<Instruction> instructMem; std::list<Instruction>::iterator currentInstruct; STATUS machineStatus;

long accumulator;

For this project. I am allowing you to use the C++ Standard Template Library version of the Vector and List. You must use these STL data types for your GritVM. The GritVM can only operate on long data types, so that is the only data type you will need to worry about for your machine data.

You will be responsible for programming in the functionality of the following instructions in your implementation of GritVM. Notice that the memory management functions match the Vector ADT nearly identically. DM represents data memory:

Instruction	Type	Call	Notes
CLEAR	Accumulator Functions	CLEAR	Set the accumulator to 0
	DM Management		Sets the accumulator to the value at
AT		AT X	DM[X]
	Functions
			A = DM[X]
	DM Management		Sets the DM[X] to the value in the
SET		SET X	accumulator
	Functions
			DM[X] = A
INSERT	DM Management	INSERT X	Inserts in DM at location X the value in the
	Functions		accumulator

Instruction	Type	Call	Notes
ERASE	DM Management	ERASE X	Erases location X in the DM
	Functions
ADDCONST	Accumulator Maths with	ADDCONST C	Adds C to the accumulator value
	a Constant		A=A+C
SUBCONST	Accumulator Maths with	SUBCONST C	Subtracts C from the accumulator
	a Constant		A=A–C
MULCONST	Accumulator Maths with	MULCONST C	Multiplies C to the accumulator value
	a Constant		A=A*C
DIVCONST	Accumulator Maths with	DIVCONST C	Divides C from the accumulator value
	a Constant		A=A/C
ADDMEM	Accumulator Maths with	ADDMEM X	Adds DM[X] to the accumulator value
	a Memory Location		A=A+DM[X]
SUBMEM	Accumulator Maths with	SUBMEM X	Subtracts DM[X] from the accumulator
	a Memory Location		A=A–DM[X]
MULMEM	Accumulator Maths with	MULMEM X	Multiplies DM[X] to the accumulator value
	a Memory Location		A=A*DM[X]
DIVMEM	Accumulator Maths with	DIVMEM X	Divides DM[X] from the accumulator value
	a Memory Location		A=A/DM[X]
JUMPREL	Instruction Jump	JUMPREL Y	Goes forward/back Y instructions from the
	Functions		current instruction (can be negative)
			Goes forward/back Y instructions from the
JUMPZERO	Instruction Jump	JUMPZERO Y	current instruction (can be negative) if
	Functions		accumulator is 0. Otherwise just move
			forward 1 from the current instruction.
			Goes forward/back Y instructions from the
JUMPNZERO	Instruction Jump	JUMPNZERO	current instruction (can be negative) if
	Functions	Y	accumulator is not 0. Otherwise just move
			forward 1 from the current instruction.
NOOP	Misc Functions	NOOP	Perform no operation. Counts as an
			instruction but does nothing.
HALT	Misc Functions	HALT	Stop the GritVM and switch status to
			HALTED
OUTPUT	Misc Functions	OUTPUT	Output accumulator to std::cout
CHECKMEM	Misc Functions	CHECKMEM Z	Checks to make sure DM is of at least size
			Z. If not, switch status to ERRORED

• • If the instructMem size is 0 set the status to WAITING,

• Otherwise, set it to READY

• Copy the vector passed into the load method to the dataMem vector

• Return the current status

• If a GritVM object is READY receiving a call to the run method, then the instructions can be evaluated

  • Otherwise, return the current status

• Evaluate the current instruction

• After evaluation, move the current instruction forward the proper amount

• • 1 for regular instructions

• • Y for jumps if a jump is triggered (where Y != 0, if Y is 0, set status to ERRORED and return run method)

• • Set status to HALTED if the last instruction was HALT or the last instruction has been reached

• Return the current status

Abstract Class Methods

There will be an abstract class provided for your GritVM class to inherit from. The following methods must be defined:

STATUS load(const std::string filename, const std::vector<long> &initialMemory)

This method loads the GVM program into the GritVM object and copies initialMemory into the data memory. Returns the current machine status. Throws if file cannot be read.

STATUS run()

This method starts the evaluation of the instructions. Returns the current machine status.

std::vector<long> getDataMem()

Returns a copy of the current dataMem

STATUS reset()

Sets the accumulator to 0, clears the dataMem and instructMem, sets the machineStatus to

WAITING.

Other things in GritVMBase hpp/cpp

Also provided in the base class files are the enums that define the various stats and instructions for the GritVM. There is an instruction struct for holding an instruction, and it’s argument. There are also five helper methods for you. All of these methods are in the namespace GVMHelper.

std::string statusToString(STATUS s); Converts a status value to a string version of that status.

STATUS stringToStatus(std::string s);

Converts a string of a status value to an enum of that status.

std::string instructionToString(INSTRUCTION_SET s); Converts an instruction value to a string version of that instruction.

INSTRUCTION_SET stringtoInstruction(std::string s); Converts a string of an instruction value to an enum of that instruction.

Instruction parseInstruction(std::string GVMLine);

Given a line of a GVM file, this function returns an Instruction struct containing the instruction enum and the long argument (if applicable)

Examples

Below are some examples of how your code should run GritVM vm;

• Status: WAITING

• Accumulator: 0

• *** Data Memory ***

• *** Instruction Memory ***

vm.load(“altseq.GVM”, inMem);

• Status: READY

• Accumulator: 0

• *** Data Memory ***

• Location 0: 15

• *** Instruction Memory ***

• Instruction 0: CHECKMEM 1

• Instruction 1: CLEAR 0

• Instruction 2: ADDCONST 1

• Instruction 3: INSERT 1

• Instruction 4: INSERT 2

• Instruction 5: AT 0

• Instruction 6: ADDCONST 1

• Instruction 7: SUBMEM 2

• Instruction 8: JUMPNZERO 2

• Instruction 9: JUMPZERO 9

• Instruction 10: CLEAR 0

• Instruction 11: AT 1

• Instruction 12: MULCONST -2

• Instruction 13: SET 1

• Instruction 14: AT 2

• Instruction 15: ADDCONST 1

• Instruction 16: SET 2

• Instruction 17: JUMPREL -12

• Instruction 18: AT 1

• Instruction 19: MULCONST 3

• Instruction 20: ADDCONST 4

• Instruction 21: SET 1

• Instruction 22: HALT 0

vm.run();

• Status: HALTED

• Accumulator: -98300

• *** Data Memory ***

• Location 0: 15

• Location 1: -98300

• Location 2: 16

• *** Instruction Memory ***

• Instruction 0: CHECKMEM 1

• Instruction 1: CLEAR 0

• Instruction 2: ADDCONST 1

• Instruction 3: INSERT 1

• Instruction 4: INSERT 2

• Instruction 5: AT 0

• Instruction 6: ADDCONST 1

• Instruction 7: SUBMEM 2

• Instruction 8: JUMPNZERO 2

• Instruction 9: JUMPZERO 9

• Instruction 10: CLEAR 0

• Instruction 11: AT 1

• Instruction 12: MULCONST -2

• Instruction 13: SET 1

• Instruction 14: AT 2

• Instruction 15: ADDCONST 1

• Instruction 16: SET 2

• Instruction 17: JUMPREL -12

• Instruction 18: AT 1

• Instruction 19: MULCONST 3

• Instruction 20: ADDCONST 4

• Instruction 21: SET 1

• Instruction 22: HALT 0

std::vector<long> outmem = vm.getDataMem();

vm.reset();

• Status: WAITING

• Accumulator: 0

• *** Data Memory ***

// *** Instruction Memory ***

Deliverables

Please submit complete projects as zipped folders. The zipped folder should contain:

• GritVM.cpp (Your written GritVM class)

• GritVM.hpp (Your written GritVM class)

• GritVMBase.cpp (The provided base class, enums, structs, and helper functions)

• GritVMBase.hpp (The provided base class, enums, structs, and helper functions)

• PP3Test.cpp (Test file)

• catch.hpp (Catch2 Header)

• altseq.gvm (A Alternating Sequence Program for GritVM)

• sumn.gvm (A Summation Program for GritVM)

• surfarea.gvm (A Surface Area Program for GritVM)

• test.gvm (A Test Program for GritVM)

And any additional source and header files needed for your project.

Hints

Remember, the math can only be done to the accumulator. You will never be doing the four functions on data memory locations. For example, the SUBMEM instruction should perform accumulator = accumulator – dataMem[instruct.argument]

I suggest you write two private methods for your GritVM, evaluate and advance. While the machine is RUNNING, the evaluate method contains a switch statement for every instruction in the instruction set and does the proper functionality. The advance method moves the current instruction by the proper amount. This way, you can have something like: while(machineStatus == RUNNING) {

// Evaluate the current instruction

long jumpDistance = evaluate(*currentInstruct);

• Advance the current instruction based on the last evaluation advance(jumpDistance);

}

It would be a good idea to have a public method that can print out all of the GritVM variables (like above in the example). I suggest something like:

void GritVM::printVM(bool printData, bool printInstruction) { cout << “****** Output Dump ******” << endl;

cout << “Status: ” <<

GVMHelper::statusToString(machineStatus) << endl;

cout << “Accumulator: ” << accumulator << endl;

if (printData) {

cout << “*** Data Memory ***” << endl; int index = 0;

vector<long>::iterator it = dataMem.begin(); while(it != dataMem.end()) {

long item = (*it);

cout << “Location ” << index++ << “: ” << item << endl; it++;

}

}

if (printInstruction) {

cout << “*** Instruction Memory ***” << endl; int index = 0;

list<Instruction>::iterator it = instructMem.begin(); while(it != instructMem.end()) {

Instruction item = (*it);

cout << “Instruction ” <<

index++ << “: ” <<

GVMHelper::instructionToString(item.operation) <<

” ” << item.argument << endl;

it++;

}

}

}

Try looking through the code of the GVM files and see if you can reverse engineer the functionality.

I would start by getting your load GritVM to load in a GVM file and make sure that all the instruction memory and data memory are working before moving forward. After that, you can work on the run loop that evaluates instructions and moves the current instruction forward.

Extra Credit

There are two opportunities for extra credit on this project.

The first is to write a program in the GVM language that calculates the minimum number of moves for a Towers of Hanoi (TOH) solution. The memory layout of the program after halting should be [N, Result] where N was the number of disks passed into the program and Result is the minimum number of steps. Try to reverse engineering other GVM programs to get your TOH program working. A working program is worth 10 extra points and is defined in the second test case.

The second opportunity is to write your own custom implementation of the list and vector used for the GritVM. You will have to be able to convert to and from the Standard Template Versions of the list and vector when taking in or outputting instruction/data memory. This will also be worth an extra 10 points.

Since these are extra credit opportunities, I will not be answering questions on the implementation details. I will only clarify questions on the requirements of the extra credit.

Rubric

Any code that does not compile will receive a zero for this project.

Criteria	Points
GritVM should be in WAITING state when no program is loaded	1
GritVM should throw if the file cannot be loaded and be in state READY	2
if the file is loaded
GritVM should run a program if READY and be HALTED when program	2
completes
GritVM produces proper output for test.gvm	6
GritVM produces proper output for sumn.gvm	6
GritVM produces proper output for surfarea.gvm	6
GritVM produces proper output for altseq.gvm	6
Student uses List for instruction memory and vector of longs for data	5
memory
Code uses object oriented design principles	3
(Separate headers and sources, where applicable)
Code is well documented	3
Total Points	40

Extra Credit

Criteria	Points
Successfully implemented a TOH GVM program (Test case 2)	10
Student implemented Vector and List classes within the GritVM	10
Total Points	20