ghc: add support for Apple Silicon with ghc 8.10.3

This PR adds support to ghc.rb for Apple Silicon Macs. This PR removes the external build of gmp in favor of using the in-tree one as the in-tree one is statically linked these days (confirmed no external gmp references). The version in-tree is 6.1.2 which does not build on Apple Silicon so it is replaced by the formula with 6.2.1 which does. In order to get a full install with a working arm64 binary we currently need to build ghc in three steps: 1) Install the ghc binaries for x86_64 into a temporary directory (this is also done for x86_64). 2) Build a cross-compiler for arm64 using the x86_64 binary to bootstrap. 3) Use either the x86_64 binaries (on x86_64) or the cross-compiler to build a native ghc for the system. This PR relies on an extensive patch based on a PR to ghc 8.10.x. These patches add support for arm64-apple-darwin and correct some build system confusion between the ghc target name (aarch64-apple-darwin) and the llvm target name (arm64-apple-darwin). Some caveats: - This build takes awhile (over 2 hours). This is a significant build time for an M1 system given it is roughly twice as fast as a Core i9. - We can probably shorten the build time by using integer-simple and disabling other libraries but this formula is a stop-gap measure until upstream releases official support (ghc 9.x series). - There is no native code generator for arm64 at this time. The resulting binaries will likely be slower than if there was a native code generator. Patch updated by @SeekingMeaning Signed-off-by: Nathan Hjelm <[email protected]>
Homebrew · Feb 1, 2021 · bf1112b · bf1112b
1 parent 775897a
commit bf1112b
Showing 1 changed file with 76 additions and 20 deletions.
diff --git a/Formula/ghc.rb b/Formula/ghc.rb
@@ -4,6 +4,7 @@ class Ghc < Formula
   url "https://downloads.haskell.org/~ghc/8.10.3/ghc-8.10.3-src.tar.xz"
   sha256 "ccdc8319549028a708d7163e2967382677b1a5a379ff94d948195b5cf46eb931"
   license "BSD-3-Clause"
+  revision 1
 
   livecheck do
     url "https://www.haskell.org/ghc/download.html"
@@ -20,10 +21,10 @@ class Ghc < Formula
   depends_on "sphinx-doc" => :build
 
   resource "gmp" do
-    url "https://ftp.gnu.org/gnu/gmp/gmp-6.2.1.tar.xz"
-    mirror "https://gmplib.org/download/gmp/gmp-6.2.1.tar.xz"
-    mirror "https://ftpmirror.gnu.org/gmp/gmp-6.2.1.tar.xz"
-    sha256 "fd4829912cddd12f84181c3451cc752be224643e87fac497b69edddadc49b4f2"
+    url "https://ftp.gnu.org/gnu/gmp/gmp-6.2.1.tar.bz2"
+    mirror "https://gmplib.org/download/gmp/gmp-6.2.1.tar.bz2"
+    mirror "https://ftpmirror.gnu.org/gmp/gmp-6.2.1.tar.bz2"
+    sha256 "eae9326beb4158c386e39a356818031bd28f3124cf915f8c5b1dc4c7a36b4d7c"
   end
 
   # https://www.haskell.org/ghc/download_ghc_8_10_1.html#macosx_x86_64
@@ -41,34 +42,89 @@ class Ghc < Formula
     end
   end
 
+  # Fixes for macOS ARM
+  # https://gitlab.haskell.org/ghc/ghc/-/merge_requests/4795
+  patch do
+    url "https://raw.githubusercontent.com/Homebrew/formula-patches/f6c5879312437dd58087e4885a86ac536a128ea9/ghc/ghc-8.10.3.patch"
+    sha256 "7aee4d6eeb37676450c84da6205e79b5ff8c9f2d4e5763f5bbf5b1c990d002b3"
+  end
+
   def install
     ENV["CC"] = ENV.cc
     ENV["LD"] = "ld"
     ENV["PYTHON"] = Formula["[email protected]"].opt_bin/"python3"
 
-    # Build a static gmp rather than in-tree gmp, otherwise all ghc-compiled
-    # executables link to Homebrew's GMP.
-    gmp = libexec/"integer-gmp"
-
-    # GMP *does not* use PIC by default without shared libs so --with-pic
-    # is mandatory or else you'll get "illegal text relocs" errors.
-    resource("gmp").stage do
-      system "./configure", "--prefix=#{gmp}", "--with-pic", "--disable-shared",
-                            "--build=#{Hardware.oldest_cpu}-apple-darwin#{OS.kernel_version.major}"
-      system "make"
-      system "make", "install"
-    end
-
-    args = ["--with-gmp-includes=#{gmp}/include",
-            "--with-gmp-libraries=#{gmp}/lib"]
+    args = []
 
     resource("binary").stage do
       binary = buildpath/"binary"
 
       system "./configure", "--prefix=#{binary}", *args
       ENV.deparallelize { system "make", "install" }
 
-      ENV.prepend_path "PATH", binary/"bin"
+      ENV["GHC"] = binary/"bin/ghc"
+    end
+
+    cpu = if Hardware::CPU.arm?
+      "arm64"
+    else
+      Hardware.oldest_cpu
+    end
+
+    # Replace in-tree gmp with 6.2.1 which supports arm64.
+    rm "libraries/integer-gmp/gmp/gmp-tarballs/gmp-6.1.2-nodoc.tar.bz2", force: true
+    cp resource("gmp").cached_download, "libraries/integer-gmp/gmp/gmp-tarballs/gmp-6.2.1-nodoc.tar.bz2"
+
+    # There is no native codegen for ARM64 yet.
+    if Hardware::CPU.arm?
+      args << "--enable-unregisterised"
+
+      # The Xcode compiler is a cross compiler (ARM64/x86_64) but ghc's configure script will look for
+      # the standard tool names. Go ahead and create the required names. We can not just use symbolic
+      # links for gcc, nm, or ar as this confuses the command line tools.
+
+      tmp = buildpath/"binary-cross"
+
+      tmpbin = tmp/"bin"
+      mkdir_p tmpbin
+
+      make_contents = lambda { |command|
+        <<~EOF
+          #!/bin/bash
+          /usr/bin/#{command} $@
+        EOF
+      }
+
+      File.write(tmpbin/"#{cpu}-apple-darwin-nm", make_contents.call("nm"), { perm: 0755 })
+      File.write(tmpbin/"#{cpu}-apple-darwin-ar", make_contents.call("ar"), { perm: 0755 })
+      # This gcc forces ARM64 as the target. It may be invoked by an x86_64 binary (which would have
+      # selected x86_64 which is not what we want.
+      File.write(tmpbin/"#{cpu}-apple-darwin-gcc", make_contents.call("gcc -arch arm64"), { perm: 0755 })
+
+      ENV.prepend_path "PATH", tmpbin
+
+      # Basic build setup for the cross compile. This is based on the documentation for building a
+      # cross compiler for targetting iOS.
+      (buildpath/"mk/build.mk").write <<~EOS
+        BuildFlavour = perf-cross
+        HADDOCK_DOCS = NO
+      EOS
+
+      ENV["CC"] = "#{cpu}-apple-darwin-gcc"
+
+      # Run configure as x86_64 to ensure it correctly detects the build host as x86_64. Otherwise it might
+      # not cross-compile correctly.
+      system "arch", "-x86_64", "./configure", "--prefix=#{tmp}", "--target=#{cpu}-apple-darwin", *args
+      system "make"
+
+      ENV.deparallelize { system "make", "install" }
+
+      # clean up before rebuilding
+      system "make", "distclean"
+      rm "#{buildpath}/mk/build.mk", force: true
+
+      ENV["CC"] = ENV.cc
+      ENV["GHC"] = tmp/"bin/ghc"
     end
 
     system "./configure", "--prefix=#{prefix}", *args