ghc: improve Sierra compatibility

On Sierra, use new upstream dynamic-library-dirs field to avoid

  ghc: panic! (the 'impossible' happened)
  malformed mach-o: load commands size (x) > 32768

where x is some number larger than 32768.

Note that this fix requires a corresponding update to cabal-install and
that `cabal new-build` hasn't been updated to use the new field yet, so
will continue to fail in the same scenarios as it already does.

Also, bump the vendored gmp to 6.1.1 for all macOS versions, and stop
using nm-classic since llvm-nm -P is POSIX compliant now.

Closes #6358.

Signed-off-by: ilovezfs <ilovezfs@icloud.com>

Formula/ghc.rb

@@ -1,8 +1,38 @@
+require "language/haskell"
+
 class Ghc < Formula
+  include Language::Haskell::Cabal
+
   desc "Glorious Glasgow Haskell Compilation System"
   homepage "https://haskell.org/ghc/"
-  url "https://downloads.haskell.org/~ghc/8.0.1/ghc-8.0.1-src.tar.xz"
+  revision 1
-  sha256 "90fb20cd8712e3c0fbeb2eac8dab6894404c21569746655b9b12ca9684c7d1d2"
+
+  stable do
+    if MacOS.version >= :sierra
+      url "https://git.haskell.org/ghc.git",
+          :branch => "ghc-8.0",
+          :revision => "9448e62740ca03aeb915bf0ecf8b16e54a52798a"
+      version "8.0.1"
+
+      depends_on "autoconf" => :build
+      depends_on "automake" => :build
+      depends_on "libtool" => :build
+
+      resource "cabal" do
+        url "https://hackage.haskell.org/package/cabal-install-1.24.0.0/cabal-install-1.24.0.0.tar.gz"
+        sha256 "d840ecfd0a95a96e956b57fb2f3e9c81d9fc160e1fd0ea350b0d37d169d9e87e"
+      end
+
+      # disables haddock for hackage-security
+      resource "cabal-patch" do
+        url "https://github.com/haskell/cabal/commit/9441fe.patch"
+        sha256 "5506d46507f38c72270efc4bb301a85799a7710804e033eaef7434668a012c5e"
+      end
+    else
+      url "https://downloads.haskell.org/~ghc/8.0.1/ghc-8.0.1-src.tar.xz"
+      sha256 "90fb20cd8712e3c0fbeb2eac8dab6894404c21569746655b9b12ca9684c7d1d2"
+    end
+  end
 
   bottle do
     cellar :any
@@ -22,10 +52,10 @@ class Ghc < Formula
   depends_on "sphinx-doc" => :build if build.with? "docs"
 
   resource "gmp" do
-    url "https://ftpmirror.gnu.org/gmp/gmp-6.1.0.tar.bz2"
+    url "https://ftpmirror.gnu.org/gmp/gmp-6.1.1.tar.xz"
-    mirror "https://gmplib.org/download/gmp/gmp-6.1.0.tar.bz2"
+    mirror "https://gmplib.org/download/gmp/gmp-6.1.1.tar.xz"
-    mirror "https://ftp.gnu.org/gnu/gmp/gmp-6.1.0.tar.bz2"
+    mirror "https://ftp.gnu.org/gnu/gmp/gmp-6.1.1.tar.xz"
-    sha256 "498449a994efeba527885c10405993427995d3f86b8768d8cdf8d9dd7c6b73e8"
+    sha256 "d36e9c05df488ad630fff17edb50051d6432357f9ce04e34a09b3d818825e831"
   end
 
   if MacOS.version <= :lion
@@ -51,15 +81,6 @@ class Ghc < Formula
     sha256 "bc57163656ece462ef61072559d491b72c5cdd694f3c39b80ac0f6b9a3dc8151"
   end
 
-  # fix clock_gettime support on 10.12
-  # https://ghc.haskell.org/trac/ghc/ticket/12195
-  if MacOS.version >= :sierra
-    patch do
-      url "https://raw.githubusercontent.com/Homebrew/formula-patches/9eef46168ca5daa1629082af5532fc4b521d1a8d/ghc/clock_gettime.patch"
-      sha256 "42444b381840d9d90202ff619f0070c28a753243af5d7e6b60efd227c6cf308c"
-    end
-  end
-
   def install
     # Setting -march=native, which is what --build-from-source does, fails
     # on Skylake (and possibly other architectures as well) with the error
@@ -112,7 +133,9 @@ class Ghc < Formula
     # https://mail.haskell.org/pipermail/ghc-devs/2016-April/011862.html
     # LLVM itself has already fixed the bug: llvm-mirror/llvm@ae7cf585
     # rdar://25311883 and rdar://25299678
-    args << "--with-nm=#{`xcrun --find nm-classic`.chomp}" if DevelopmentTools.clang_build_version >= 703
+    if DevelopmentTools.clang_build_version >= 703 && DevelopmentTools.clang_build_version < 800
+      args << "--with-nm=#{`xcrun --find nm-classic`.chomp}"
+    end
 
     resource("binary").stage do
       binary = buildpath/"binary"
@@ -123,6 +146,25 @@ class Ghc < Formula
       ENV.prepend_path "PATH", binary/"bin"
     end
 
+    if MacOS.version == :sierra
+      resource("cabal").stage do
+        Pathname.pwd.install resource("cabal-patch")
+        system "patch", "-p2", "-i", "9441fe.patch"
+        system "sh", "bootstrap.sh", "--sandbox", "--no-doc"
+        (buildpath/"bootstrap-tools/bin").install ".cabal-sandbox/bin/cabal"
+      end
+
+      ENV.prepend_path "PATH", buildpath/"bootstrap-tools/bin"
+
+      cabal_sandbox do
+        cabal_install "--only-dependencies", "happy", "alex"
+        cabal_install "--prefix=#{buildpath}/bootstrap-tools", "happy", "alex"
+      end
+
+      inreplace "libraries/filepath/filepath.cabal", "cabal-version:  >=1.10",
+                                                     "cabal-version:  >=1.18"
+      system "./boot"
+    end
     system "./configure", "--prefix=#{prefix}", *args
     system "make"