Homework 3: Make Your Makefile

Now it's time to make your own Makefile! The Makefile will contain all the compilation and linking steps to make an executable called our-movie. You and your partner (together or individually) should complete the written questions in Part 1 before working on this part.

In the asciimation directory, you'll find a file called our-movie.cpp, which contains a main function. There are also three pairs of header/implementation files:

• sprite.cpp and sprite.hpp, which you'll use to create ASCII-art–based “characters”
• asciimation.cpp and asciimation.hpp, which you'll use to coordinate the “characters” on the screen
• ncurses-helper.cpp and ncurses-helper.hpp, which are wrappers around the ncurses library (see below) that we've written for you, but that you shouldn't have to modify.

Reminder: Compiling by Hand

If you compiled this code by hand, you would have to run several complex commands, specifically:

clang++ -g -std=c++17 -c -pedantic -Wall -Wextra boundingbox.cpp
clang++ -g -std=c++17 -c -pedantic -Wall -Wextra boundingbox-test.cpp
clang++ -g -std=c++17 -c -pedantic -Wall -Wextra sprite.cpp
clang++ -g -std=c++17 -c -pedantic -Wall -Wextra sprite-test.cpp
clang++ -g -std=c++17 -c -pedantic -Wall -Wextra display.cpp
clang++ -g -std=c++17 -c -pedantic -Wall -Wextra display-test.cpp
clang++ -g -std=c++17 -c -pedantic -Wall -Wextra asciimation.cpp
clang++ -g -std=c++17 -c -pedantic -Wall -Wextra our-movie.cpp

to build all the object files (boundingbox.o, boundingbox-test.o, sprite.o, sprite-test.o, display.o, display-test.o, asciimation.o, and our-movie.o); and, finally,

clang++ -g -std=c++17 -o boundingbox-test boundingbox-test.o boundingbox.o -ltestinglogger
clang++ -g -std=c++17 -o sprite-test sprite-test.o sprite.o boundingbox.o -ltestinglogger
clang++ -g -std=c++17 -o display-test display-test.o display.o -lncurses
clang++ -g -std=c++17 -o our-movie our-movie.o asciimation.o sprite.o display.o boundingbox.o -lncurses

to build three test executables (boundingbox-test, sprite-test, and display-test) and the final executable (our-movie). Note that the -ltestinglogger flag is needed to link the testing library into the test executables, and the -lncurses flag is needed to link the ncurses library into the our-movie executable.

Remembering all the different arguments for clang++ is a pain, and you will also have to figure which commands you need to rerun if you make changes to one or more files. You could keep detailed notes about which files depend on each other, like this:

• boundingbox.cpp uses boundingbox.hpp
• boundingbox-test.cpp uses boundingbox.hpp
• sprite.cpp uses sprite.hpp and boundingbox.hpp
• sprite-test.cpp uses sprite.hpp and boundingbox.hpp
• display.cpp uses display.hpp
• display-test.cpp uses display.hpp
• asciimation.cpp uses asciimation.hpp, display.hpp, sprite.hpp, and boundingbox.hpp
• our-movie.cpp uses asciimation.hpp, display.hpp, sprite.hpp, and boundingbox.hpp

and

• boundingbox-test needs to be relinked if boundingbox-test.o or boundingbox.o changes
• sprite-test needs to be relinked if sprite-test.o or sprite.o or boundingbox.o changes
• display-test needs to be relinked if display-test.o or display.o changes
• our-movie needs to be relinked if our-movie.o or asciimation.o or sprite.o or display.o or boundingbox.o changes

But keeping track of all this, remembering all the commands, and running them at the proper time is tedious and error-prone, which is why we use build systems like make.

A “makefile” for the project allows you to figure out commands and dependencies once and then let the make program decide what needs to be rebuilt for later builds.

Your Task: Create Your Makefile and Use It

Make Your Makefile

Create a makefile for your project (which, by convention, is called Makefile when there is just one) in the asciimation directory with all of the commands you'll need to compile the our-movie executable. You will be graded on how “well” your Makefile performs; for example, compiling only what's necessary for any given change and doing those compilations correctly.

Include both the all: and clean: targets in your Makefile.

If you're looking for an example you can use as a starting point, the segfault-generator directory contains an example of a very basic Makefile, as did the make exercise that you saw at the start of the written part of this assignment (which also had more advanced examples, with variables).

Note that you do not have to comment your Makefile as we did in our example. We added those comments for your benefit! For basic makefiles like the ones we will use in CS 70, it's probably not necessary to add comments. (Of course you can always include comments if you want.)

Test Your Makefile

Once you've written your Makefile, you should be able to run cs70-make or make in the asciimation directory to generate any of the .o files, and to link the .o files to make the three executables: boundingbox-test, sprite-test, and our-movie.

    clang++ -o generateSegfault -g -std=c++11 -pedantic -Wall -Wextra generateSegfault.o helloSayer.o -lncurses

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