lab04 : Odds and primes: Fun with arrays and makefiles

num ready? description assigned due
lab04 true Odds and primes: Fun with arrays and makefiles Fri 09/27 09:00AM Sat 12/14 11:59PM

Introduction

Step 1: Log on to CSIL and bring up a terminal window.

As a reminder to get to the terminal go to Application Menu, then System Tools, then Terminal Window.

Step 2: Create a new repo, and clone it to your local directory

In lab02, we have done the same thing. So if you don’t know to how to do that, please refer to lab02 for details. The basic steps are as follows:

Step 3: Get the starter code from a local directory

Copy the skeleton to your local lab04 repo using the following command, REMEMBER to change the directory name in the commands below to your own directory’s name, in this lab we simply use lab04_jgaucho as a example for your local git directory:

  cp /cs/faculty/richert/public_html/cs16/lab04/* ~/cs16/lab04_jgaucho/

Typing the list (ls) command should show you the following files in your current directory

[-bash-4.2]$ ls
arrayBoundsDemo        Makefile                 sumOdds.o
arrayBoundsDemo.cpp    maxOfArray.cpp           sumOddsTest
arrayBoundsDemo.o      maxOfArrayErrorTest      sumOddsTest.cpp
arrayFuncs.h           maxOfArrayErrorTest.cpp  sumOddsTest.o
arrayToString.cpp      maxOfArrayErrorTest.o    sumOfArray.cpp
arrayToString.o        maxOfArray.o             sumOfArray.o
arrayToStringTest      maxOfArrayTest           sumOfArrayTest
arrayToStringTest.cpp  maxOfArrayTest.cpp       sumOfArrayTest.cpp
arrayToStringTest.o    maxOfArrayTest.o         sumOfArrayTest.o
countEvens.cpp         minOfArray.cpp           tddFuncs.cpp
countEvens.o           minOfArrayErrorTest      tddFuncs.h
countEvensTest         minOfArrayErrorTest.cpp  tddFuncs.o
countEvensTest.cpp     minOfArrayErrorTest.o    utility.cpp
countEvensTest.o       minOfArray.o             utility.h
countPrimes.cpp        minOfArrayTest           utility.o
countPrimes.o          minOfArrayTest.cpp       utilityTest
countPrimesTest        minOfArrayTest.o         utilityTest.cpp
countPrimesTest.cpp    README.md                utilityTest.o
countPrimesTest.o      sumOdds.cpp
[-bash-4.2]$

Push the initial version of the code on github before making any changes by typing the following commands

git add .
git commit -m "Initial version"
git push origin master

Step 4: Reviewing Separate Compilation

The files in your directory this week use separate compilation, that is each program is not necessarily taking all of its code from a single .cpp source file.

In Lecture, we introduced the idea of separate compilation, where your C++ program may be divided among multiple source files. The following web page explains more about separate compilation, dividing your program up among multiple C++ and .h files, and using a Makefile. I strongly encourage you to read over it briefly before you proceed with the lab: Separate Compilation and Makefiles

Step 5: Writing isOdd(), isEven() and isPrime()

Your first step is very simple to describe, but somewhat challenging. The challenge here is mostly C++ coding — we will not get into the details of the separate compilation until a bit later.

To get started, do the following steps:

Step 5a: make clean

In your working directory, type ls and make note of the different files therein: some are .cpp types, some are .o (short for “object file”), some are .h (short for “header file”), and others do not have extensions (they are binary executables). Now, type make clean. This command cleans out any .o files and executables from your directory

That should look like this:

-bash-4.2$ make clean
/bin/rm -f arrayToStringTest arrayBoundsDemo countEvensTest minOfArrayTest minOfArrayErrorTest
countPrimesTest maxOfArrayTest maxOfArrayErrorTest sumOddsTest sumOfArrayTest utilityTest *.o

-bash-4.2$

Take a look in the Makefile file to understand why this happened.

Step 5b: make utilityTest

This command makes the executable for a main program, defined in utilityTest.cpp, that tests the functions defined in utility.cpp. Recall that for functions defined in a file such as utility.cpp that has no main(), the function prototypes are defined in the file utility.h Look at the source code for both utility.cpp and utility.h to see what they contain. Recall that a “stub” is place-holder code that allows an incomplete function to compile. It is designed to fail all the tests, though for a boolean function, since there are only two possible values (true and false), any stub value you choose is going to pass at least some of the tests.

That should look like this:

-bash-4.2$ make utilityTest
g++ -Wall -Wno-uninitialized   -c -o utilityTest.o utilityTest.cpp
g++ -Wall -Wno-uninitialized   -c -o tddFuncs.o tddFuncs.cpp
g++ -Wall -Wno-uninitialized   -c -o utility.o utility.cpp
g++ -Wall -Wno-uninitialized  utilityTest.o tddFuncs.o utility.o -o utilityTest

-bash-4.2$

Step 5c: Run ./utilityTest

Next, type ./utilityTest

This runs the utilityTest program that tests the three functions isOdd, isEven and isPrime. As we noted above, some of the tests will pass, even though the implementation of the three functions is totally bogus (hard coded to return false always).

Here is what that looks like (some output truncated)

-bash-4.2$ ./utilityTest
	FAILED: isEven(2)
		Expected: 1 Actual: 0
PASSED: isEven(3)
	FAILED: isEven(4)
		Expected: 1 Actual: 0
PASSED: isEven(55)

[...      Some output omitted here... ]

PASSED: isPrime(64507)
	FAILED: isPrime(69997)
		Expected: 1 Actual: 0
PASSED: isPrime(-55)
PASSED: isPrime(-80)
PASSED: isPrime(0)
PASSED: isPrime(1)

-bash-4.2$

Step 5d: Repeat: edit, compile, run, until all tests pass

Now do these steps, repeatedly, until all tests pass:

edit utility.cpp
make utilityTest
run utilityTest (e.g. ./utilityTest)

Submit working versions of your code on github using the commands:

git add *.cpp *.h
git commit -m "implemented utility function - nameof function()"
git push origin master

You must only proceed with the rest of the lab once you have implemented all the utility functions and pass the provided test cases. This is because for other files that you will be editing later, you will NEED functions isOdd, isEven and isPrime. Once you get them working, you will be able to call them in other files and KNOW that they work properly. You will not have to rewrite the function definition.

When all the tests for utlityTest pass, do a final push to github and move on to the next step.

Step 6: Reviewing the rest of the files and what your tasks are<

Now, let us look at the files you actually have in your directory, and what you need to do with them. You have the following .cpp files. This table indicates what you must do with each one to get full credit on this lab.

Filename Your task Details
arrayBoundsDemo.cpp NOTHING TO CHANGE OR SUBMIT. This is here as example code only. You are encouraged to run it, study it, and learn about how array bounds work in C++
arrayToString.cpp NOTHING TO CHANGE OR SUBMIT. This code is part of your solution, but you do not have to submit it - we will use our own version, which matches the one in your sample directory. This file just has utiltiy funcitons for printing arrays as strings.
arrayToStringTest.cpp NOTHING TO CHANGE OR SUBMIT. This code is part of your solution, but you do not have to submit it - we will use our own version, which matches the one in your sample directory. This file is an example of how to test cases to determine whether the output of arrayToString works correctly.
countEvens.cpp REPLACE STUB WITH CORRECT CODE. You must replace the code in this file with correct code that returns the number of even integers in each array passed in.
countEvensTest.cpp NO MODIFICATIONS NEEDED This tests the changes you made in countEvens.cpp.
countPrimes.cpp REPLACE STUB WITH CORRECT CODE. You must replace the code in this file with correct code that returns the number of prime integers in each array passed in. Treat negative numbers, 0 and 1 as “not prime”. You may want to add a definition of isPrime() to the utility.cpp file and a function prototype to utility.h so that you can call function isPrime in your solution.
countPrimesTest.cpp NO MODIFICATIONS NEEDED This tests the changes you made in countEvens.cpp.
maxOfArray.cpp REPLACE STUB WITH CORRECT CODE. You can look at minOfArray.cpp for hints. This one should be easy.
maxOfArrayErrorTest.cpp REPLACE EMPTY MAIN WITH TESTS. Insert code to call maxOfArray with zero length array. Use minOfArrayErrorTest.cpp as a model.
maxOfArrayTest.cpp REPLACE EMPTY MAIN WITH TESTS. Insert code to call assertEqual exactly seven times testing whether maxOfArray returns correct values. Use minOfArrayTest.cpp as a model. It must be exactly “seven” calls to assertEquals to pass the Gradescope tests. You should call your arrays the same things that they are called in minOfArrayTests, and the lengths should be the same. So the messages you get out for passed tests should match the messages from minOfArrayTests except that the name of the function is maxOfArray instead of minOfArray. You MAY change the values in the arrays themselves, though, to make the tests better tests, if you need to. (Note that just hard coding a program that prints “PASSED” seven times with the apprpriate messages is not sufficient to get credit–you need to really have actual tests. Any attempt to “game the system”, i.e. to get Gradescope tests to pass without a bona-fide attempt to actually solve the problem will get zero credit.)
minOfArray.cpp NOTHING TO CHANGE. This is a model of correct code that can serve as a hint for how to write maxOfArray.cpp
minOfArrayErrorTest.cpp NOTHING TO CHANGE. This is an model of correct code for how to test whether a function behaves as expected when given input that should print a message to cerr and exit the progrm.
minOfArrayTest.cpp NOTHING TO CHANGE. This is a model of how to do unit testing on a function that returns an integer.
sumOdds.cpp REPLACE STUB WITH CORRECT CODE. You must replace the code in this file with correct code that returns the number of sum of the odd integers in each array passed in. Negative odd integers count as odd integers.
sumOddsTest.cpp REPLACE EMPTY MAIN WITH TESTS Insert code to call assertEqual exactly seven times testing whether sumOdds returns correct values. Use sumOfArrayTest.cpp as a model. It must be exactly “seven” calls to assertEquals to pass the Gradescope tests. You should call your arrays the same things that they are called in sumOfArrayTests, and the lengths should be the same. So the messages you get out for passed tests should match the messages from sumOfArrayTests except that the name of the function tested is sumOdds instead of sumOfArray. You MAY change the values in the arrays themselves, though, to make the tests better tests, if you need to. (Note that just hard coding a program that prints “PASSED” seven times with the apprpriate messages is not sufficient to get credit–you need to really have actual tests. Any attempt to “game the system”, i.e. to get Gradescope tests to pass without a bona-fide attempt to actually solve the problem will get zero credit.)
sumOfArray.cpp INCORRECT CODE FOR YOU TO FIX. The sum is not initialized properly. So the tests should fail. Your job is to see that the tests fail, then fix the sum initialization so the tests pass. Should be easy.
sumOfArrayTest.cpp NOTHING TO CHANGE. This is a set of tests to verify whether sumOfArray() works correctly.
tddFuncs.cpp NOTHING TO CHANGE. These are two functions that can be used to test functions that return either int or string values.
utility.cpp ADD FUNCTIONS HERE AS NEEDED. If you need to write your own helper functions, e.g. isPrime, isOdd, isEven, to use in other files, here is where you can put those definitions.

Step 7: Actually Getting Started

I suggest you start by typing: make

You should see a lot of activity as programs are compiled. You then will have a lot of executables you can run. Here is a list. Try running each one and see what happens.

Note these are the programs listed under BINARIES in the Makefile.

file Anything to do? explanation
arrayToStringTest no Run this and all tests should pass. Nothing to do here.
arrayBoundsDemo no Run this, and look at the code. This is an opportunity to learn something about how we pass arrays to functions in C++, but there is nothing you have to turn in from this program for the lab. It is just here as an example for you to learn from.
countEvensTest YES Run this, and you will see all the tests fail. YOU NEED TO FIX THE countEvens function and then get all these tests to pass.
minOfArrayTest no Just run this and see the tests pass. You can use the .cpp file minOfArrayTest.cpp as a model for writing maxOfArrayTest.cpp
minOfArrayErrorTest no Just run this and see the output. It should be ERROR: minOfArray called with size < 1 printed on cerr (the standard error output stream). The Gradescope system will check this as one of the acceptance tests for this lab, and it will also check that maxOfArrayErrorTest does the same thing. You can use the .cpp file minOfArrayErrorTest.cpp as a model for writing maxOfArrayErrorTest.cpp
countPrimesTest YES Run this, and you will see all the tests fail. YOU NEED TO FIX THE countPrimes function and then get all these tests to pass.
maxOfArrayTest YES Run this, and you will see that initially there is no output. That is because the main is empty. YOU NEED TO REPLACE THIS MAIN with code that tests maxOfArray. Use minOfArrayTest as a model. Initially, just put in the tests, and keep maxOfArray returning the stub vaue -42. See all the tests fail. Then get maxOfArray to return the right values and see all the tests pass.
maxOfArrayErrorTest YES Run this, and you will see that initially there is no output. That is because the main() is empty. YOU NEED TO REPLACE THIS MAIN with code that tests maxOfArray. Use minOfArrayTest as a model. Initially, just put in the tests, and keep maxOfArray returning the stub vaue -42. See all the tests fail. Then get maxOfArray to return the right values and see all the tests pass.
sumOddsTest YES Run this, and you will see that initially there is no output. That is because the main() is empty. YOU NEED TO REPLACE THIS MAIN with code that tests sumOdds. Use minOfArrayTest as a model. Initially, just put in the tests, and keep sumOdds returning the stub vaue -42. See all the tests fail. Then get sumOdds to return the right values and see all the tests pass.
sumOfArrayTest YES Run sumOfArrayTest and you will see that all the tests fail. Getting them to pass is probably the easiest step in this lab. Just look at the sumOfArray function, which is almost correct - it just needs you to initialize sum correctly. Note that in C/C++ variables are NOT automatically initialized, and failing to initialize them does not always result in an error message or warning unless you specifically ask the compiler to tell you about those. For this lab, the Makefile deliberarly turns that warning OFF so that we have to catch that ourselves.

So, if you go through that list, and do all the things indicated, you are finished with the lab and ready to submit.

Step 8: Checking your work before submitting

When you are finished, you should be able to type make tests and see the following output:

-bash-4.2$ make tests
./arrayToStringTest
PASSED: arrayToString(fiveThrees,5)
PASSED: arrayToString(zeros,3)
PASSED: arrayToString(empty,0)
PASSED: arrayToString(primes,10)
PASSED: arrayToString(meaning,1)
PASSED: arrayToString(mix,10)
./countEvensTest
PASSED: countEvens(fiveThrees,5)
PASSED: countEvens(zeros,3)
PASSED: countEvens(fiveInts,5)
PASSED: countEvens(empty,0)
PASSED: countEvens(primes,10)
PASSED: countEvens(meaning,1)
PASSED: countEvens(mix,10)
./countPrimesTest
PASSED: countPrimes(fiveThrees,5)
PASSED: countPrimes(zeros,3)
PASSED: countPrimes(fiveInts,5)
PASSED: countPrimes(empty,0)
PASSED: countPrimes(primes,10)
PASSED: countPrimes(meaning,1)
PASSED: countPrimes(mix,10)
./maxOfArrayTest
PASSED: maxOfArray(fiveThrees,5)
PASSED: maxOfArray(zeros,3)
PASSED: maxOfArray(fiveInts,5)
PASSED: maxOfArray(fiveInts,2)
PASSED: maxOfArray(fiveInts,3)
PASSED: maxOfArray(meaning,1)
PASSED: maxOfArray(mix,10)
./minOfArrayTest
PASSED: minOfArray(fiveThrees,5)
PASSED: minOfArray(zeros,3)
PASSED: minOfArray(fiveInts,5)
PASSED: minOfArray(fiveInts,2)
PASSED: minOfArray(fiveInts,3)
PASSED: minOfArray(meaning,1)
PASSED: minOfArray(mix,10)
./sumOddsTest
PASSED: sumOdds(fiveThrees,5)
PASSED: sumOdds(zeros,3)
PASSED: sumOdds(fiveInts,5)
PASSED: sumOdds(fiveInts,3)
PASSED: sumOdds(fiveInts,2)
PASSED: sumOdds(meaning,1)
PASSED: sumOdds(mix,10)
./sumOfArrayTest
PASSED: sumOfArray(fiveThrees,5)
PASSED: sumOfArray(zeros,3)
PASSED: sumOfArray(fiveInts,5)
PASSED: sumOfArray(fiveInts,3)
PASSED: sumOfArray(fiveInts,2)
PASSED: sumOfArray(meaning,1)
PASSED: sumOfArray(mix,10)
./utilityTest
PASSED: isEven(2)
PASSED: isEven(3)
PASSED: isEven(4)
PASSED: isEven(55)
PASSED: isEven(-55)
PASSED: isEven(-80)
PASSED: isOdd(2)
PASSED: isOdd(3)
PASSED: isOdd(4)
PASSED: isOdd(55)
PASSED: isOdd(-55)
PASSED: isOdd(-80)
PASSED: isPrime(2)
PASSED: isPrime(3)
PASSED: isPrime(4)
PASSED: isPrime(55)
PASSED: isPrime(859)
PASSED: isPrime(861)
PASSED: isPrime(863)
PASSED: isPrime(1337)
PASSED: isPrime(1373)
PASSED: isPrime(64507)
PASSED: isPrime(69997)
PASSED: isPrime(-55)
PASSED: isPrime(-80)
PASSED: isPrime(0)
PASSED: isPrime(1)

-bash-4.2$

And, you should be able to type make errorTests and see the following output:

-bash-4.2$ make errorTests
./minOfArrayErrorTest
ERROR: minOfArray called with size < 1
make: [errorTests] Error 1 (ignored)
./maxOfArrayErrorTest
ERROR: maxOfArray called with size < 1
make: [errorTests] Error 1 (ignored)

-bash-4.2$

At that point, you are ready to try submitting on the Gradescope system.

Step 9: Turn in your code on Gradescope 

-bash-4.2$ cd ~/cs16/lab04_jgaucho

-bash-4.2$ cd ~/cs16/lab04_jgaucho
-bash-4.2$ ls
arrayBoundsDemo.cpp    maxOfArray.cpp           sumOfArray.cpp
arrayFuncs.h           maxOfArrayErrorTest.cpp  sumOfArrayTest.cpp
arrayToString.cpp      maxOfArrayTest.cpp       tddFuncs.cpp
arrayToStringTest.cpp  minOfArray.cpp           tddFuncs.h
countEvens.cpp         minOfArrayErrorTest.cpp  utility.cpp
countEvensTest.cpp     minOfArrayTest.cpp       utility.h
countPrimes.cpp        README.md                utilityTest
countPrimesTest.cpp    sumOdds.cpp              utilityTest.cpp
Makefile               sumOddsTest.cpp
-bash-4.2$

Submit all the .cpp files to lab04 assignment on Gradescope and check that you have a correct score.

  1. Indentation is neat, consistent and follows good practice (see below)
  2. Variable name choice: variables should have sensible names. More on indentation: Your code should be indented neatly. Code that is inside braces should be indented, and code that is at the same “level” of nesting inside braces should be indented in a consistent way. Follow the examples from lecture, the sample code, and from the textbook.