Problem installing Pari on OS 10.7

[callan <callan@cs.wisc.edu>]

The instructions to install Pari on a Mac running OS X seem inadequate.
Following the FAQ on "How can I get/use gp under MacOS X", I downloaded 
and installed XCode 4.6.2, pari-2.7.1, and readline-6.2 on a MacBook Air 
running OS 10.7.5.
I did not actually do anything with XCode.

Then, in Terminal, I got the following error message:


Graces-MacBook-Air:readline-6.2 gracewahba$  ./configure
checking build system type... i386-apple-darwin11.4.2
checking host system type... i386-apple-darwin11.4.2

Beginning configuration for readline-6.2 for i386-apple-darwin11.4.2

checking whether make sets $(MAKE)... no
checking for gcc... no
checking for cc... no
checking for cl.exe... no
configure: error: in `/Users/gracewahba/readline-6.2':
configure: error: no acceptable C compiler found in $PATH
See `config.log' for more details.


What am I doing wrong or failing to do?

Any help much appreciated.

Thanks,

David Callan