A Makefile is a file that serves as a "map" to build a project from the command line (or using an IDE like in your case). It is good practice to use a Makefile to compile complex projects composed of many files, since the compilation can be done with or without the IDE (Eclipse in your case). To compile your project outside Eclipse, just type "make" from the command line.
In your case, somehow you have selected the option to compile using a makefile (this option in my opinion is the best).
To solve your problem from this point (without having to re-create the project), just add a blank file to your project:
File-> New-> Other
Expand "General" and select "File"
Name it "Makefile" (it is important to put this name) (I assume that your source code is stored in a file named "main.cpp" and that your executable will be called "hello") (I assume also that the g++ is installed on your system, as some Linux distributions have gcc preinstalled only)
Edit the file "Makefile" (in the same Eclipse if you like) with the following: (it is important to respect the tabs!)
all: main.o g++ -o hello main.o main.o: main.cpp g++ -c main.cpp clean: rm *.o
Now, when you compile your project, you should see something like this: (in the "console" tab)
make all g++ -c main.cpp g++ -o hello main.o
This is the simplest Makefile you can create for your project. There is plenty of help available on the web about the syntax of the Makefile for much more complex builds.
g++, it will give an error similar toCannot run program "g++", which means exactly what you'd think (also +1 for being another Arch user).New > C++ Project. I really don't know anything about makefiles (though I know I probably need to learn). since the code is so simple though, I think I should be able to just useg++directly through eclipse instead of having to create one