Change Default Compiler Within Emacs?

Question

I use M-x compile within Emacs to compile my C code which then initiates make -k and allows me to compile the code. I wish to use Clang (or conceivably GCC 4.8 after I install it) as the default compiler. I have cc aliased to clang -Wall -Werror -std=c99 -ggdb -O0 and while this invokes Clang from the command line outside of Emacs, invoking M-x compile from within Emacs still seems to alias cc to GCC version 4.7 which is what I have installed. I wish to tap into the richer and more understandable error and warning messages provided by Clang (and GCC 4.8) but do not wish to create a separate makefile for every short student-level program I am writing, since I am currently going through K&R including solving the exercises.

How do I convince Emacs that M-x compile and make -k should invoke Clang (or GCC 4.8) instead of the older version of GCC?

Answer 1

This isn't emacs, it's make. It defaults to using the environment variable CC, which in turn defaults to gcc. Just run this before you start emacs (assuming you're using Unix):

$ export CC=clang

Alternatively, use a makefile that specifies CC directly.