New formula: fuse4x-kext

This formula provides the kernel extension required to run FUSE-based
filesystems using fuse4x.

Signed-off-by: Charlie Sharpsteen <source@sharpsteen.net>

Formula/fuse4x-kext.rb

@@ -0,0 +1,41 @@
+require 'formula'
+
+def kext_prefix
+  prefix + 'Library' + 'Extensions'
+end
+
+class Fuse4xKext < Formula
+  homepage 'http://fuse4x.org/'
+  url 'https://github.com/fuse4x/kext.git', :tag => "fuse4x_0_8_12"
+  version "0.8.12"
+
+  def install
+    ENV.delete('CC')
+    ENV.delete('CXX')
+
+    args = [
+      "-sdk",
+      "macosx#{MACOS_VERSION}",
+      "-configuration", "Release",
+      "-alltargets",
+      "MACOSX_DEPLOYMENT_TARGET=#{MACOS_VERSION}",
+      "SYMROOT=build"
+    ]
+    # Don't build a multi-arch kext for Leopard---it will fail.
+    args.concat %w[ARCHS=i386 ONLY_ACTIVE_ARCH=NO] if MacOS.leopard?
+
+    system "/usr/bin/xcodebuild", *args
+    system "/bin/mkdir -p build/Release/fuse4x.kext/Support"
+    system "/bin/cp build/Release/load_fuse4x build/Release/fuse4x.kext/Support"
+
+    kext_prefix.install "build/Release/fuse4x.kext"
+  end
+
+  def caveats
+    <<-EOS.undent
+      In order for FUSE-based filesystems to work, the fuse4x kernel extension
+      must be installed by the root user:
+        sudo cp -rfX #{kext_prefix}/fuse4x.kext /System/Library/Extensions
+    EOS
+  end
+end