Nehalem supports SSE4.2

Signed Off By: Max Howell <max@methylblue.com>

I realised that -msse4.1 and -msse4.2 aren't supported by GCC 4.0, so I made
the brash decision that we require GCC 4.2. It comes with Xcode 3.1 so people
can upgrade if they have to.

Requiring a single compiler is better for us anyway -- less possible errors
and failures.

Formulae can still request gcc-4.0.1, but at least then those formulae still
only use a single compiler and not possibly two.

1 files changed, 3 insertions, 1 deletions

diff --git a/bin/brew b/bin/brew
index de7af280a..c1d8e50e6 100755
--- a/bin/brew
+++ b/bin/brew
@@ -34,7 +34,9 @@ end
 if Hardware.cpu_type == :ppc or Hardware.cpu_type == :dunno
   abort "Sorry, Homebrew does not support your computer's CPU architecture."
 end
-
+unless system "which gcc-4.2 &> /dev/null" and $?.success?
+  abort "Sorry, Homebrew requires gcc 4.2, which is provided by Xcode 3.1"
+end
 
 begin
   case ARGV.shift