mnewt · August 17, 2020 16:52 · Aug 17, 2020
diff --git a/gccemacs.rb b/gccemacs.rb
@@ -0,0 +1,76 @@
+class Emacs < Formula
+  desc "GNU Emacs Native Compiled"
+  homepage "https://akrl.sdf.org/gccemacs.html"
+  head "git://git.sv.gnu.org/emacs.git", :branch => "feature/native-comp"
+
+  depends_on "autoconf" => :build
+  depends_on "pkg-config" => :build
+  depends_on "texinfo" => :build
+  depends_on "gcc"
+  depends_on "gnupg"
+  depends_on "gnutls"
+  depends_on "jansson"
+  depends_on "librsvg"
+
+  uses_from_macos "libxml2"
+
+  def install
+    gcc_version = if Formula["gcc"].head?
+        "HEAD"
+      else
+        Formula["gcc"].version.to_s.slice(/\d+/)
+      end
+
+    # cores = `sysctl -n hw.ncpu`.chomp
+
+    # - Transform ctags name to ctags.emacs so it doesn't conflict with other
+    #   ctags installations that may exist.
+    # - Build without ImageMagick because the macOS build uses the native Cocoa
+    #   image library instead.
+    args = %W[
+      --program-transform-name='s/^ctags$/ctags.emacs/'
+      --enable-locallisppath=#{HOMEBREW_PREFIX}/share/emacs/site-lisp
+      --infodir=#{info}/emacs
+      --prefix=#{prefix}
+      --with-nativecomp
+      --without-imagemagick
+      --without-dbus
+      --without-pop
+    ]
+
+    ENV["CFLAGS"] = %w[
+      -Ofast
+      -march=native
+      -pipe
+      -falign-functions=64
+      -fomit-frame-pointer
+      -funit-at-a-time
+      -fforce-addr
+      -mfpmath=sse
+      -fno-finite-math-only
+      -fstack-check
+    ].join(" ")
+    ENV["LDFLAGS"] = "-Wl"
+
+    ENV["BYTE_COMPILE_EXTRA_FLAGS"] = "--eval '(setq comp-speed 2)'"
+    ENV.prepend_path "LIBRARY_PATH", File.join(
+      Formula["gcc"].opt_prefix, "/lib/gcc/", gcc_version, "/lib"
+    )
+
+    if build.head?
+      ENV.prepend_path "PATH", Formula["gnu-sed"].opt_libexec / "gnubin"
+      system "./autogen.sh"
+    end
+
+    system "./configure", *args
+    system "make", "install"
+    # mv "lisp", "nextstep/Emacs.app/Contents"
+    # mv "nextstep/Emacs.app", prefix
+    # print "To install the GUI app, run:"
+    # print "mv #{prefix}/Emacs.app ~/Applications"
+  end
+
+  test do
+    assert_equal "4", shell_output("#{bin}/emacs --batch --eval=\"(print (+ 2 2))\"").strip
+  end
+end