libvpx: fix compilation with CLT/Xcode 4.3

Remove the option to --enable-postproc because it's always enabled
Set --disable-runtime-cpu-detect so it's detected during make.
Don't allow --gcov when compiling with Clang. Cleans up warnings.
Remove the O-level from cflags with Clang.  Cleans up warnings.
This was tested on 32bit and 64bit Snow Leopard 10.6.8 using
all three compilers from XCode-4.0.2, and it was tested on Lion
using both compilers from XCode-4.2.1.

Signed-off-by: Jack Nagel <jacknagel@gmail.com>

Formula/libvpx.rb

@@ -11,28 +11,54 @@ class Libvpx < Formula
     [
       ['--gcov', 'Enable code coverage'],
       ['--mem-tracker', 'Enable tracking memory usage'],
-      ['--postproc','Enable post processing'],
       ['--visualizer', 'Enable post processing visualizer']
     ]
   end
 
+  def patches
+    # see http://code.google.com/p/webm/issues/detail?id=396
+    # Remove attempts by configure to specify a -isysroot path on Lion.
+    # It's never needed on Lion because the correct default is set within
+    # the compiler and because a CLT only user will never have an SDK path.
+    # This stops a compile error for CLT-4.3 where configure malforms the
+    # conftest command by using -isysroot without a path argument.  This
+    # is what the command looks like when it's missing the arg:
+    #       -isysroot -mmacosx-version-min=10.7
+    DATA if MacOS.lion?
+  end
+
   def install
     args = ["--prefix=#{prefix}",
             "--enable-pic",
-            "--enable-vp8"]
-    args << "--enable-gcov" if ARGV.include? "--gcov"
+            "--enable-vp8",
+            "--disable-debug",
+            "--disable-examples",
+            "--disable-runtime-cpu-detect"]
+    args << "--enable-gcov" if ARGV.include? "--gcov" and not ENV.compiler == :clang
     args << "--enable-mem-tracker" if ARGV.include? "--mem-tracker"
-    args << "--enable-postproc" if ARGV.include? "--postproc"
     args << "--enable-postproc-visualizer" if ARGV.include? "--visualizer"
 
-    # Unless the arch is specified, configure tries to build universal.
-    # Patches welcome to detect and apply the real arch strings on each platform.
-    args << "--target=generic-gnu"
+    # see http://code.google.com/p/webm/issues/detail?id=401
+    args << '--target=generic-gnu'
 
     mkdir 'macbuild' do
       system "../configure", *args
-      system "make"
       system "make install"
     end
   end
 end
+
+__END__
+--- a/build/make/configure.sh	2012-01-27 10:36:39.000000000 -0800
++++ b/build/make/configure.sh	2012-02-20 20:14:04.000000000 -0800
+@@ -649,10 +649,6 @@
+             add_ldflags "-mmacosx-version-min=10.6"
+             ;;
+         *-darwin11-*)
+-            add_cflags  "-isysroot ${osx_sdk_dir}"
+-            add_cflags  "-mmacosx-version-min=10.7"
+-            add_ldflags "-isysroot ${osx_sdk_dir}"
+-            add_ldflags "-mmacosx-version-min=10.7"
+             ;;
+     esac
+