How to install 'make' and GCC on a Mac

I want to install Eclim on my MacBook Air (2011 version). But there are some problems I faced during the installation. It told me that I did not install make and GCC.

I tried to find the solution for it, but all solutions are talking about using Xcode. In fact, I installed Xcode.

But I still cannot install Eclim because there are no make and GCC installed.

How can I install them so that I can install Eclim?

Solution

Update for newer versions:

The command line versions can now be installed straight from the command line itself;

Open "Terminal" (it is located in Applications/Utilities)
In the terminal window, run the command xcode-select --install
In the windows that pops up, click Install, and agree to the Terms of Service.

Once the installation is complete, the command line utilities should be set up property.

Older versions:

Installing recent Xcode versions confusingly enough does not automatically install the command line tools. To install the command line tools when they're not automatically installed;

Start Xcode.
Go to Xcode/Preferences.
Click the "Downloads" tab.
Click "Components".
Click "Install" on the command line tools line.

That will install the command line tools and make them accessible from a regular command line.