Merge pull request #26799 from obsidiansystems/cross-haskell

haskell infra: Fix cross compilation to work with new system
2018-01-22 15:31:19 -05:00
parent cf3ada04a7 13739e6b9e
commit ec0c4802ae
20 changed files with 776 additions and 312 deletions
--- a/pkgs/development/compilers/ghc/6.10.2-binary.nix
+++ b/pkgs/development/compilers/ghc/6.10.2-binary.nix
@@ -96,7 +96,11 @@ stdenv.mkDerivation rec {
    [ $(./main) == "yes" ]
  '';

-  passthru = { targetPrefix = ""; };
+  passthru = {
+    targetPrefix = "";
+    # Our Cabal compiler name
+    haskellCompilerName = "ghc";
+  };

  meta = {
    homepage = http://haskell.org/ghc;
--- a/pkgs/development/compilers/ghc/6.10.4.nix
+++ b/pkgs/development/compilers/ghc/6.10.4.nix
@@ -25,7 +25,12 @@ stdenv.mkDerivation rec {

  NIX_CFLAGS_COMPILE = "-fomit-frame-pointer";

-  passthru = { targetPrefix = ""; };
+  passthru = {
+    targetPrefix = "";
+
+    # Our Cabal compiler name
+    haskellCompilerName = "ghc";
+  };

  meta = {
    homepage = http://haskell.org/ghc;
--- a/pkgs/development/compilers/ghc/6.12.3.nix
+++ b/pkgs/development/compilers/ghc/6.12.3.nix
@@ -23,7 +23,7 @@ stdenv.mkDerivation rec {
  '';

  preConfigure = ''
-    echo "${buildMK}" > mk/build.mk
+    echo -n "${buildMK}" > mk/build.mk
  '';

  configureFlags = [
@@ -36,7 +36,12 @@ stdenv.mkDerivation rec {
  # that in turn causes GHCi to abort
  stripDebugFlags=["-S" "--keep-file-symbols"];

-  passthru = { targetPrefix = ""; };
+  passthru = {
+    targetPrefix = "";
+
+    # Our Cabal compiler name
+    haskellCompilerName = "ghc";
+  };

  meta = {
    homepage = http://haskell.org/ghc;
--- a/pkgs/development/compilers/ghc/7.0.4-binary.nix
+++ b/pkgs/development/compilers/ghc/7.0.4-binary.nix
@@ -134,7 +134,12 @@ stdenv.mkDerivation rec {
    [ $(./main) == "yes" ]
  '';

-  passthru = { targetPrefix = ""; };
+  passthru = {
+    targetPrefix = "";
+
+    # Our Cabal compiler name
+    haskellCompilerName = "ghc";
+  };

  meta.license = stdenv.lib.licenses.bsd3;
  meta.platforms = ["x86_64-linux" "i686-linux" "x86_64-darwin"];
--- a/pkgs/development/compilers/ghc/7.0.4.nix
+++ b/pkgs/development/compilers/ghc/7.0.4.nix
@@ -28,7 +28,7 @@ stdenv.mkDerivation rec {
  '';

  preConfigure = ''
-    echo "${buildMK}" > mk/build.mk
+    echo -n "${buildMK}" > mk/build.mk
    sed -i -e 's|-isysroot /Developer/SDKs/MacOSX10.5.sdk||' configure
  '' + stdenv.lib.optionalString stdenv.isDarwin ''
    find . -name '*.hs'  | xargs sed -i -e 's|ASSERT (|ASSERT(|' -e 's|ASSERT2 (|ASSERT2(|' -e 's|WARN (|WARN(|'
@@ -45,7 +45,12 @@ stdenv.mkDerivation rec {
  # that in turn causes GHCi to abort
  stripDebugFlags=["-S" "--keep-file-symbols"];

-  passthru = { targetPrefix = ""; };
+  passthru = {
+    targetPrefix = "";
+
+    # Our Cabal compiler name
+    haskellCompilerName = "ghc";
+  };

  meta = {
    homepage = http://haskell.org/ghc;
--- a/pkgs/development/compilers/ghc/7.10.3.nix
+++ b/pkgs/development/compilers/ghc/7.10.3.nix
@@ -2,15 +2,28 @@
 , buildPlatform, hostPlatform, targetPlatform

 # build-tools
-, bootPkgs, hscolour, llvm_35
+, bootPkgs, hscolour
 , coreutils, fetchurl, fetchpatch, perl
 , docbook_xsl, docbook_xml_dtd_45, docbook_xml_dtd_42, libxml2, libxslt

-, libiconv ? null, ncurses
+, libffi, libiconv ? null, ncurses
+
+, useLLVM ? !targetPlatform.isx86
+, # LLVM is conceptually a run-time-only depedendency, but for
+  # non-x86, we need LLVM to bootstrap later stages, so it becomes a
+  # build-time dependency too.
+  buildLlvmPackages, llvmPackages

 , # If enabled, GHC will be built with the GPL-free but slower integer-simple
  # library instead of the faster but GPLed integer-gmp library.
  enableIntegerSimple ? false, gmp ? null
+
+, # If enabled, use -fPIC when compiling static libs.
+  enableRelocatedStaticLibs ? targetPlatform != hostPlatform
+
+, # Whether to build dynamic libs for the standard library (on the target
+  # platform). Static libs are always built.
+  enableShared ? true
 }:

 assert !enableIntegerSimple -> gmp != null;
@@ -28,6 +41,32 @@ let
    sha256 = "1j45z4kcd3w1rzm4hapap2xc16bbh942qnzzdbdjcwqznsccznf0";
  };

+  buildMK = ''
+    DYNAMIC_GHC_PROGRAMS = ${if enableShared then "YES" else "NO"}
+  '' + stdenv.lib.optionalString enableIntegerSimple ''
+    INTEGER_LIBRARY = integer-simple
+  '' + stdenv.lib.optionalString (targetPlatform != hostPlatform) ''
+    BuildFlavour = perf-cross
+    Stage1Only = YES
+    HADDOCK_DOCS = NO
+  '' + stdenv.lib.optionalString enableRelocatedStaticLibs ''
+    GhcLibHcOpts += -fPIC
+    GhcRtsHcOpts += -fPIC
+  '';
+
+  # Splicer will pull out correct variations
+  libDeps = platform: [ ncurses ]
+    ++ stdenv.lib.optional (!enableIntegerSimple) gmp
+    ++ stdenv.lib.optional (platform.libc != "glibc") libiconv;
+
+  toolsForTarget =
+    if hostPlatform == buildPlatform then
+      [ targetPackages.stdenv.cc ] ++ stdenv.lib.optional useLLVM llvmPackages.llvm
+    else assert targetPlatform == hostPlatform; # build != host == target
+      [ stdenv.cc ] ++ stdenv.lib.optional useLLVM buildLlvmPackages.llvm;
+
+  targetCC = builtins.head toolsForTarget;
+
 in

 stdenv.mkDerivation rec {
@@ -39,37 +78,77 @@ stdenv.mkDerivation rec {
    sha256 = "1vsgmic8csczl62ciz51iv8nhrkm72lyhbz7p7id13y2w7fcx46g";
  };

+  enableParallelBuilding = true;
+
+  outputs = [ "out" "doc" ];
+
  patches = [
    docFixes
    ./relocation.patch
  ];

-  buildInputs = [ ghc perl libxml2 libxslt docbook_xsl docbook_xml_dtd_45 docbook_xml_dtd_42 hscolour ] ++ stdenv.lib.optionals targetPlatform.isArm [ llvm_35 ];
-
-  enableParallelBuilding = true;
-
-  outputs = [ "out" "doc" ];
-
+  # GHC is a bit confused on its cross terminology.
  preConfigure = ''
+    for env in $(env | grep '^TARGET_' | sed -E 's|\+?=.*||'); do
+      export "''${env#TARGET_}=''${!env}"
+    done
+    # GHC is a bit confused on its cross terminology, as these would normally be
+    # the *host* tools.
+    export CC="${targetCC}/bin/${targetCC.targetPrefix}cc"
+    export CXX="${targetCC}/bin/${targetCC.targetPrefix}cxx"
+    export LD="${targetCC.bintools}/bin/${targetCC.bintools.targetPrefix}ld"
+    export AS="${targetCC.bintools.bintools}/bin/${targetCC.bintools.targetPrefix}as"
+    export AR="${targetCC.bintools.bintools}/bin/${targetCC.bintools.targetPrefix}ar"
+    export NM="${targetCC.bintools.bintools}/bin/${targetCC.bintools.targetPrefix}nm"
+    export RANLIB="${targetCC.bintools.bintools}/bin/${targetCC.bintools.targetPrefix}ranlib"
+    export READELF="${targetCC.bintools.bintools}/bin/${targetCC.bintools.targetPrefix}readelf"
+    export STRIP="${targetCC.bintools.bintools}/bin/${targetCC.bintools.targetPrefix}strip"
+    echo -n "${buildMK}" > mk/build.mk
    sed -i -e 's|-isysroot /Developer/SDKs/MacOSX10.5.sdk||' configure
  '' + stdenv.lib.optionalString (!stdenv.isDarwin) ''
-    export NIX_LDFLAGS="$NIX_LDFLAGS -rpath $out/lib/ghc-${version}"
+    export NIX_LDFLAGS+=" -rpath $out/lib/ghc-${version}"
  '' + stdenv.lib.optionalString stdenv.isDarwin ''
    export NIX_LDFLAGS+=" -no_dtrace_dof"
-  '' + stdenv.lib.optionalString enableIntegerSimple ''
-    echo "INTEGER_LIBRARY=integer-simple" > mk/build.mk
  '';

+  # TODO(@Ericson2314): Always pass "--target" and always prefix.
+  configurePlatforms = [ "build" "host" ]
+    ++ stdenv.lib.optional (targetPlatform != hostPlatform) "target";
+  # `--with` flags for libraries needed for RTS linker
  configureFlags = [
-    "--with-gcc=${stdenv.cc}/bin/cc"
-    "--with-curses-includes=${ncurses.dev}/include" "--with-curses-libraries=${ncurses.out}/lib"
    "--datadir=$doc/share/doc/ghc"
-  ] ++ stdenv.lib.optional (! enableIntegerSimple) [
+    "--with-curses-includes=${ncurses.dev}/include" "--with-curses-libraries=${ncurses.out}/lib"
+  ] ++ stdenv.lib.optional (targetPlatform == hostPlatform && ! enableIntegerSimple) [
    "--with-gmp-includes=${gmp.dev}/include" "--with-gmp-libraries=${gmp.out}/lib"
-  ] ++ stdenv.lib.optional stdenv.isDarwin [
+  ] ++ stdenv.lib.optional (targetPlatform == hostPlatform && hostPlatform.libc != "glibc") [
    "--with-iconv-includes=${libiconv}/include" "--with-iconv-libraries=${libiconv}/lib"
+  ] ++ stdenv.lib.optionals (targetPlatform != hostPlatform) [
+    "--enable-bootstrap-with-devel-snapshot"
+  ] ++ stdenv.lib.optionals (targetPlatform.isDarwin && targetPlatform.isAarch64) [
+    # fix for iOS: https://www.reddit.com/r/haskell/comments/4ttdz1/building_an_osxi386_to_iosarm64_cross_compiler/d5qvd67/
+    "--disable-large-address-space"
  ];

+  # Hack to make sure we never to the relaxation `$PATH` and hooks support for
+  # compatability. This will be replaced with something clearer in a future
+  # masss-rebuild.
+  crossConfig = true;
+
+  nativeBuildInputs = [
+    ghc perl libxml2 libxslt docbook_xsl docbook_xml_dtd_45 docbook_xml_dtd_42 hscolour
+  ];
+
+  # For building runtime libs
+  depsBuildTarget = toolsForTarget;
+
+  buildInputs = libDeps hostPlatform;
+
+  propagatedBuildInputs = [ targetPackages.stdenv.cc ]
+    ++ stdenv.lib.optional useLLVM llvmPackages.llvm;
+
+  depsTargetTarget = map stdenv.lib.getDev (libDeps targetPlatform);
+  depsTargetTargetPropagated = map (stdenv.lib.getOutput "out") (libDeps targetPlatform);
+
  # required, because otherwise all symbols from HSffi.o are stripped, and
  # that in turn causes GHCi to abort
  stripDebugFlags = [ "-S" ] ++ stdenv.lib.optional (!targetPlatform.isDarwin) "--keep-file-symbols";
@@ -88,6 +167,11 @@ stdenv.mkDerivation rec {

  passthru = {
    inherit bootPkgs targetPrefix;
+
+    inherit llvmPackages;
+
+    # Our Cabal compiler name
+    haskellCompilerName = "ghc";
  };

  meta = {
@@ -96,4 +180,5 @@ stdenv.mkDerivation rec {
    maintainers = with stdenv.lib.maintainers; [ marcweber andres peti ];
    inherit (ghc.meta) license platforms;
  };
+
 }
--- a/pkgs/development/compilers/ghc/7.2.2.nix
+++ b/pkgs/development/compilers/ghc/7.2.2.nix
@@ -31,14 +31,14 @@ stdenv.mkDerivation rec {
      libraries/base_CONFIGURE_OPTS += --configure-option=--with-iconv-libraries="${libiconv}/lib"
    ''}
  '' + (if enableIntegerSimple then ''
-    INTEGER_LIBRARY=integer-simple
+    INTEGER_LIBRARY = integer-simple
  '' else ''
    libraries/integer-gmp_CONFIGURE_OPTS += --configure-option=--with-gmp-libraries="${gmp.out}/lib"
    libraries/integer-gmp_CONFIGURE_OPTS += --configure-option=--with-gmp-includes="${gmp.dev}/include"
  '');

  preConfigure = ''
-    echo "${buildMK}" > mk/build.mk
+    echo -n "${buildMK}" > mk/build.mk
    sed -i -e 's|-isysroot /Developer/SDKs/MacOSX10.5.sdk||' configure
  '' + stdenv.lib.optionalString stdenv.isDarwin ''
    find . -name '*.hs'  | xargs sed -i -e 's|ASSERT (|ASSERT(|' -e 's|ASSERT2 (|ASSERT2(|' -e 's|WARN (|WARN(|'
@@ -55,7 +55,12 @@ stdenv.mkDerivation rec {
  # that in turn causes GHCi to abort
  stripDebugFlags=["-S" "--keep-file-symbols"];

-  passthru = { targetPrefix = ""; };
+  passthru = {
+    targetPprefix = "";
+
+    # Our Cabal compiler name
+    haskellCompilerName = "ghc";
+  };

  meta = {
    homepage = http://haskell.org/ghc;
--- a/pkgs/development/compilers/ghc/7.4.2-binary.nix
+++ b/pkgs/development/compilers/ghc/7.4.2-binary.nix
@@ -136,7 +136,12 @@ stdenv.mkDerivation rec {
    [ $(./main) == "yes" ]
  '';

-  passthru = { targetPrefix = ""; };
+  passthru = {
+    targetPrefix = "";
+
+    # Our Cabal compiler name
+    haskellCompilerName = "ghc";
+  };

  meta.license = stdenv.lib.licenses.bsd3;
  meta.platforms = ["x86_64-linux" "i686-linux" "x86_64-darwin"];
--- a/pkgs/development/compilers/ghc/7.4.2.nix
+++ b/pkgs/development/compilers/ghc/7.4.2.nix
@@ -32,17 +32,17 @@ stdenv.mkDerivation rec {
      libraries/base_CONFIGURE_OPTS += --configure-option=--with-iconv-libraries="${libiconv}/lib"
    ''}
  '' + (if enableIntegerSimple then ''
-    INTEGER_LIBRARY=integer-simple
+    INTEGER_LIBRARY = integer-simple
  '' else ''
    libraries/integer-gmp_CONFIGURE_OPTS += --configure-option=--with-gmp-libraries="${gmp.out}/lib"
    libraries/integer-gmp_CONFIGURE_OPTS += --configure-option=--with-gmp-includes="${gmp.dev}/include"
  '');

  preConfigure = ''
-    echo "${buildMK}" > mk/build.mk
+    echo -n "${buildMK}" > mk/build.mk
    sed -i -e 's|-isysroot /Developer/SDKs/MacOSX10.5.sdk||' configure
  '' + stdenv.lib.optionalString (!stdenv.isDarwin) ''
-    export NIX_LDFLAGS="$NIX_LDFLAGS -rpath $out/lib/ghc-${version}"
+    export NIX_LDFLAGS+=" -rpath $out/lib/ghc-${version}"
  '' + stdenv.lib.optionalString stdenv.isDarwin ''
    find . -name '*.hs'  | xargs sed -i -e 's|ASSERT (|ASSERT(|' -e 's|ASSERT2 (|ASSERT2(|' -e 's|WARN (|WARN(|'
    find . -name '*.lhs' | xargs sed -i -e 's|ASSERT (|ASSERT(|' -e 's|ASSERT2 (|ASSERT2(|' -e 's|WARN (|WARN(|'
@@ -56,7 +56,12 @@ stdenv.mkDerivation rec {
  # that in turn causes GHCi to abort
  stripDebugFlags = [ "-S" ] ++ stdenv.lib.optional (!stdenv.isDarwin) "--keep-file-symbols";

-  passthru = { targetPrefix = ""; };
+  passthru = {
+    targetPrefix = "";
+
+    # Our Cabal compiler name
+    haskellCompilerName = "ghc";
+  };

  meta = {
    homepage = http://haskell.org/ghc;
--- a/pkgs/development/compilers/ghc/7.6.3.nix
+++ b/pkgs/development/compilers/ghc/7.6.3.nix
@@ -43,14 +43,14 @@ in stdenv.mkDerivation rec {
    SRC_HC_OPTS += ${ghcFlags}
    SRC_CC_OPTS += ${cFlags}
  '' + (if enableIntegerSimple then ''
-    INTEGER_LIBRARY=integer-simple
+    INTEGER_LIBRARY = integer-simple
  '' else ''
    libraries/integer-gmp_CONFIGURE_OPTS += --configure-option=--with-gmp-libraries="${gmp.out}/lib"
    libraries/integer-gmp_CONFIGURE_OPTS += --configure-option=--with-gmp-includes="${gmp.dev}/include"
  '');

  preConfigure = ''
-    echo "${buildMK}" > mk/build.mk
+    echo -n "${buildMK}" > mk/build.mk
    sed -i -e 's|-isysroot /Developer/SDKs/MacOSX10.5.sdk||' configure

  '' + stdenv.lib.optionalString stdenv.isLinux ''
@@ -58,7 +58,7 @@ in stdenv.mkDerivation rec {
    sed -i -e 's|"\$topdir"|"\$topdir" ${ghcFlags}|' ghc/ghc.wrapper

  '' + stdenv.lib.optionalString (!stdenv.isDarwin) ''
-    export NIX_LDFLAGS="$NIX_LDFLAGS -rpath $out/lib/ghc-${version}"
+    export NIX_LDFLAGS+=" -rpath $out/lib/ghc-${version}"
  '' + stdenv.lib.optionalString stdenv.isDarwin ''
    find . -name '*.hs'  | xargs sed -i -e 's|ASSERT (|ASSERT(|' -e 's|ASSERT2 (|ASSERT2(|' -e 's|WARN (|WARN(|'
    find . -name '*.lhs' | xargs sed -i -e 's|ASSERT (|ASSERT(|' -e 's|ASSERT2 (|ASSERT2(|' -e 's|WARN (|WARN(|'
@@ -82,7 +82,12 @@ in stdenv.mkDerivation rec {
  # that in turn causes GHCi to abort
  stripDebugFlags = [ "-S" ] ++ stdenv.lib.optional (!stdenv.isDarwin) "--keep-file-symbols";

-  passthru = { targetPrefix = ""; };
+  passthru = {
+    targetPrefix = "";
+
+    # Our Cabal compiler name
+    haskellCompilerName = "ghc";
+  };

  meta = {
    homepage = http://haskell.org/ghc;
--- a/pkgs/development/compilers/ghc/7.8.4.nix
+++ b/pkgs/development/compilers/ghc/7.8.4.nix
@@ -1,4 +1,7 @@
-{ stdenv, fetchurl, ghc, perl, ncurses, libiconv
+{ stdenv, targetPackages
+
+, fetchurl, ghc, perl
+, libffi, libiconv ? null, ncurses

 , # If enabled, GHC will be built with the GPL-free but slower integer-simple
  # library instead of the faster but GPLed integer-gmp library.
@@ -9,51 +12,74 @@
 assert stdenv.targetPlatform == stdenv.hostPlatform;
 assert !enableIntegerSimple -> gmp != null;

-stdenv.mkDerivation (rec {
-  version = "7.8.4";
-  name = "ghc-${version}";
-
-  src = fetchurl {
-    url = "https://downloads.haskell.org/~ghc/${version}/ghc-${version}-src.tar.xz";
-    sha256 = "1i4254akbb4ym437rf469gc0m40bxm31blp6s1z1g15jmnacs6f3";
-  };
-
-  patches = [ ./relocation.patch ];
-
-  buildInputs = [ ghc perl ncurses ]
-                ++ stdenv.lib.optional (!enableIntegerSimple) gmp;
-
-  enableParallelBuilding = true;
-
+let
  buildMK = ''
    libraries/terminfo_CONFIGURE_OPTS += --configure-option=--with-curses-includes="${ncurses.dev}/include"
    libraries/terminfo_CONFIGURE_OPTS += --configure-option=--with-curses-libraries="${ncurses.out}/lib"
    DYNAMIC_BY_DEFAULT = NO
-    ${stdenv.lib.optionalString stdenv.isDarwin ''
+    ${stdenv.lib.optionalString (stdenv.hostPlatform.libc != "glibc") ''
      libraries/base_CONFIGURE_OPTS += --configure-option=--with-iconv-includes="${libiconv}/include"
      libraries/base_CONFIGURE_OPTS += --configure-option=--with-iconv-libraries="${libiconv}/lib"
    ''}
  '' + (if enableIntegerSimple then ''
-    INTEGER_LIBRARY=integer-simple
+    INTEGER_LIBRARY = integer-simple
  '' else ''
    libraries/integer-gmp_CONFIGURE_OPTS += --configure-option=--with-gmp-libraries="${gmp.out}/lib"
    libraries/integer-gmp_CONFIGURE_OPTS += --configure-option=--with-gmp-includes="${gmp.dev}/include"
  '');

+  # Splicer will pull out correct variations
+  libDeps = [ ncurses ]
+    ++ stdenv.lib.optional (!enableIntegerSimple) gmp
+    ++ stdenv.lib.optional (stdenv.hostPlatform.libc != "glibc") libiconv;
+
+in
+
+stdenv.mkDerivation rec {
+  version = "7.8.4";
+  name = "ghc-${version}";
+
+  src = fetchurl {
+    url = "http://www.haskell.org/ghc/dist/${version}/${name}-src.tar.xz";
+    sha256 = "1i4254akbb4ym437rf469gc0m40bxm31blp6s1z1g15jmnacs6f3";
+  };
+
+  enableParallelBuilding = true;
+
+  patches = [ ./relocation.patch ]
+    ++ stdenv.lib.optional stdenv.isDarwin ./hpc-7.8.4.patch;
+
  preConfigure = ''
-    echo "${buildMK}" > mk/build.mk
+    echo -n "${buildMK}" > mk/build.mk
    sed -i -e 's|-isysroot /Developer/SDKs/MacOSX10.5.sdk||' configure
  '' + stdenv.lib.optionalString (!stdenv.isDarwin) ''
-    export NIX_LDFLAGS="$NIX_LDFLAGS -rpath $out/lib/ghc-${version}"
+    export NIX_LDFLAGS+=" -rpath $out/lib/ghc-${version}"
  '' + stdenv.lib.optionalString stdenv.isDarwin ''
    export NIX_LDFLAGS+=" -no_dtrace_dof"
  '';

+  # TODO(@Ericson2314): Always pass "--target" and always prefix.
+  configurePlatforms = [ "build" "host" ];
+
+  nativeBuildInputs = [ ghc perl ];
+  depsBuildTarget = [ targetPackages.stdenv.cc ];
+
+  buildInputs = libDeps;
+  propagatedBuildInputs = [ targetPackages.stdenv.cc ];
+
+  depsTargetTarget = map stdenv.lib.getDev libDeps;
+  depsTargetTargetPropagated = map (stdenv.lib.getOutput "out") libDeps;
+
  # required, because otherwise all symbols from HSffi.o are stripped, and
  # that in turn causes GHCi to abort
  stripDebugFlags = [ "-S" ] ++ stdenv.lib.optional (!stdenv.isDarwin) "--keep-file-symbols";

-  passthru = { targetPrefix = ""; };
+  passthru = {
+    targetPrefix = "";
+
+    # Our Cabal compiler name
+    haskellCompilerName = "ghc";
+  };

  meta = {
    homepage = http://haskell.org/ghc;
@@ -62,7 +88,4 @@ stdenv.mkDerivation (rec {
    inherit (ghc.meta) license platforms;
  };

-} // stdenv.lib.optionalAttrs stdenv.isDarwin {
-  # https://ghc.haskell.org/trac/ghc/ticket/9762
-  patches = [ ./hpc-7.8.4.patch ];
-})
+}
--- a/pkgs/development/compilers/ghc/8.0.2.nix
+++ b/pkgs/development/compilers/ghc/8.0.2.nix
@@ -2,14 +2,27 @@
 , buildPlatform, hostPlatform, targetPlatform

 # build-tools
-, bootPkgs, hscolour, llvm_37
-, coreutils, fetchurl, fetchpatch, patchutils, perl, sphinx
+, bootPkgs, hscolour
+, coreutils, fetchpatch, fetchurl, perl, sphinx

-, libiconv ? null, ncurses
+, libffi, libiconv ? null, ncurses
+
+, useLLVM ? !targetPlatform.isx86
+, # LLVM is conceptually a run-time-only depedendency, but for
+  # non-x86, we need LLVM to bootstrap later stages, so it becomes a
+  # build-time dependency too.
+  buildLlvmPackages, llvmPackages

 , # If enabled, GHC will be built with the GPL-free but slower integer-simple
  # library instead of the faster but GPLed integer-gmp library.
  enableIntegerSimple ? false, gmp ? null
+
+, # If enabled, use -fPIC when compiling static libs.
+  enableRelocatedStaticLibs ? targetPlatform != hostPlatform
+
+, # Whether to build dynamic libs for the standard library (on the target
+  # platform). Static libs are always built.
+  enableShared ? true
 }:

 assert !enableIntegerSimple -> gmp != null;
@@ -21,6 +34,33 @@ let
  targetPrefix = stdenv.lib.optionalString
    (targetPlatform != hostPlatform)
    "${targetPlatform.config}-";
+
+  buildMK = ''
+    DYNAMIC_GHC_PROGRAMS = ${if enableShared then "YES" else "NO"}
+  '' + stdenv.lib.optionalString enableIntegerSimple ''
+    INTEGER_LIBRARY = integer-simple
+  '' + stdenv.lib.optionalString (targetPlatform != hostPlatform) ''
+    BuildFlavour = perf-cross
+    Stage1Only = YES
+    HADDOCK_DOCS = NO
+  '' + stdenv.lib.optionalString enableRelocatedStaticLibs ''
+    GhcLibHcOpts += -fPIC
+    GhcRtsHcOpts += -fPIC
+  '';
+
+  # Splicer will pull out correct variations
+  libDeps = platform: [ ncurses ]
+    ++ stdenv.lib.optional (!enableIntegerSimple) gmp
+    ++ stdenv.lib.optional (platform.libc != "glibc") libiconv;
+
+  toolsForTarget =
+    if hostPlatform == buildPlatform then
+      [ targetPackages.stdenv.cc ] ++ stdenv.lib.optional useLLVM llvmPackages.llvm
+    else assert targetPlatform == hostPlatform; # build != host == target
+      [ stdenv.cc ] ++ stdenv.lib.optional useLLVM buildLlvmPackages.llvm;
+
+  targetCC = builtins.head toolsForTarget;
+
 in
 stdenv.mkDerivation rec {
  version = "8.0.2";
@@ -31,43 +71,87 @@ stdenv.mkDerivation rec {
    sha256 = "1c8qc4fhkycynk4g1f9hvk53dj6a1vvqi6bklqznns6hw59m8qhi";
  };

-  patches = [ ./ghc-gold-linker.patch ]
-    ++ stdenv.lib.optional stdenv.isLinux ./ghc-no-madv-free.patch
-    ++ stdenv.lib.optional stdenv.isDarwin ./ghc-8.0.2-no-cpp-warnings.patch;
-
-  buildInputs = [ ghc perl hscolour sphinx ] ++ stdenv.lib.optionals (stdenv.isArm || stdenv.isAarch64) [ llvm_37 ];
-
  enableParallelBuilding = true;

  outputs = [ "out" "man" "doc" ];

+  patches = [
+    ./ghc-gold-linker.patch
+    (fetchpatch { # Unreleased 1.24.x commit
+      url = "https://github.com/haskell/cabal/commit/6394cb0b6eba91a8692a3d04b2b56935aed7cccd.patch";
+      sha256 = "14xxjg0nb1j1pw0riac3v385ka92qhxxblfmwyvbghz7kry6axy0";
+      stripLen = 1;
+      extraPrefix = "libraries/Cabal/";
+    })
+  ] ++ stdenv.lib.optional stdenv.isLinux ./ghc-no-madv-free.patch
+    ++ stdenv.lib.optional stdenv.isDarwin ./ghc-8.0.2-no-cpp-warnings.patch;
+
+  # GHC is a bit confused on its cross terminology.
  preConfigure = ''
+    for env in $(env | grep '^TARGET_' | sed -E 's|\+?=.*||'); do
+      export "''${env#TARGET_}=''${!env}"
+    done
+    # GHC is a bit confused on its cross terminology, as these would normally be
+    # the *host* tools.
+    export CC="${targetCC}/bin/${targetCC.targetPrefix}cc"
+    export CXX="${targetCC}/bin/${targetCC.targetPrefix}cxx"
+    export LD="${targetCC.bintools}/bin/${targetCC.bintools.targetPrefix}ld"
+    export AS="${targetCC.bintools.bintools}/bin/${targetCC.bintools.targetPrefix}as"
+    export AR="${targetCC.bintools.bintools}/bin/${targetCC.bintools.targetPrefix}ar"
+    export NM="${targetCC.bintools.bintools}/bin/${targetCC.bintools.targetPrefix}nm"
+    export RANLIB="${targetCC.bintools.bintools}/bin/${targetCC.bintools.targetPrefix}ranlib"
+    export READELF="${targetCC.bintools.bintools}/bin/${targetCC.bintools.targetPrefix}readelf"
+    export STRIP="${targetCC.bintools.bintools}/bin/${targetCC.bintools.targetPrefix}strip"
+    echo -n "${buildMK}" > mk/build.mk
    sed -i -e 's|-isysroot /Developer/SDKs/MacOSX10.5.sdk||' configure
  '' + stdenv.lib.optionalString (!stdenv.isDarwin) ''
-    export NIX_LDFLAGS="$NIX_LDFLAGS -rpath $out/lib/ghc-${version}"
+    export NIX_LDFLAGS+=" -rpath $out/lib/ghc-${version}"
  '' + stdenv.lib.optionalString stdenv.isDarwin ''
    export NIX_LDFLAGS+=" -no_dtrace_dof"
-  '' + stdenv.lib.optionalString enableIntegerSimple ''
-    echo "INTEGER_LIBRARY=integer-simple" > mk/build.mk
  '';

+  # TODO(@Ericson2314): Always pass "--target" and always prefix.
+  configurePlatforms = [ "build" "host" ]
+    ++ stdenv.lib.optional (targetPlatform != hostPlatform) "target";
+  # `--with` flags for libraries needed for RTS linker
  configureFlags = [
-    "--with-gcc=${stdenv.cc}/bin/cc"
-    "--with-curses-includes=${ncurses.dev}/include" "--with-curses-libraries=${ncurses.out}/lib"
    "--datadir=$doc/share/doc/ghc"
-  ] ++ stdenv.lib.optional (! enableIntegerSimple) [
+    "--with-curses-includes=${ncurses.dev}/include" "--with-curses-libraries=${ncurses.out}/lib"
+  ] ++ stdenv.lib.optional (targetPlatform == hostPlatform && ! enableIntegerSimple) [
    "--with-gmp-includes=${gmp.dev}/include" "--with-gmp-libraries=${gmp.out}/lib"
-  ] ++ stdenv.lib.optional stdenv.isDarwin [
+  ] ++ stdenv.lib.optional (targetPlatform == hostPlatform && hostPlatform.libc != "glibc") [
    "--with-iconv-includes=${libiconv}/include" "--with-iconv-libraries=${libiconv}/lib"
+  ] ++ stdenv.lib.optionals (targetPlatform != hostPlatform) [
+    "--enable-bootstrap-with-devel-snapshot"
  ] ++ stdenv.lib.optionals (targetPlatform.isDarwin && targetPlatform.isAarch64) [
    # fix for iOS: https://www.reddit.com/r/haskell/comments/4ttdz1/building_an_osxi386_to_iosarm64_cross_compiler/d5qvd67/
    "--disable-large-address-space"
  ];

+  # Hack to make sure we never to the relaxation `$PATH` and hooks support for
+  # compatability. This will be replaced with something clearer in a future
+  # masss-rebuild.
+  crossConfig = true;
+
+  nativeBuildInputs = [ ghc perl hscolour sphinx ];
+
+  # For building runtime libs
+  depsBuildTarget = toolsForTarget;
+
+  buildInputs = libDeps hostPlatform;
+
+  propagatedBuildInputs = [ targetPackages.stdenv.cc ]
+    ++ stdenv.lib.optional useLLVM llvmPackages.llvm;
+
+  depsTargetTarget = map stdenv.lib.getDev (libDeps targetPlatform);
+  depsTargetTargetPropagated = map (stdenv.lib.getOutput "out") (libDeps targetPlatform);
+
  # required, because otherwise all symbols from HSffi.o are stripped, and
  # that in turn causes GHCi to abort
  stripDebugFlags = [ "-S" ] ++ stdenv.lib.optional (!targetPlatform.isDarwin) "--keep-file-symbols";

+  # zsh and other shells are smart about `{ghc}` but bash isn't, and doesn't
+  # treat that as a unary `{x,y,z,..}` repetition.
  postInstall = ''
    paxmark m $out/lib/${name}/bin/${if targetPlatform != hostPlatform then "ghc" else "{ghc,haddock}"}

@@ -84,6 +168,11 @@ stdenv.mkDerivation rec {

  passthru = {
    inherit bootPkgs targetPrefix;
+
+    inherit llvmPackages;
+
+    # Our Cabal compiler name
+    haskellCompilerName = "ghc";
  };

  meta = {
--- a/pkgs/development/compilers/ghc/8.2.2.nix
+++ b/pkgs/development/compilers/ghc/8.2.2.nix
@@ -1,16 +1,31 @@
 { stdenv, targetPackages
 , buildPlatform, hostPlatform, targetPlatform
-, selfPkgs, cross ? null

 # build-tools
-, bootPkgs, alex, happy, hscolour, llvm_39
-, autoconf, automake, coreutils, fetchurl, perl, python3, sphinx
+, bootPkgs, alex, happy, hscolour
+, autoconf, autoreconfHook, automake, coreutils, fetchurl, fetchpatch, perl, python3, sphinx

-, libiconv ? null, ncurses
+, libffi, libiconv ? null, ncurses
+
+, useLLVM ? !targetPlatform.isx86
+, # LLVM is conceptually a run-time-only depedendency, but for
+  # non-x86, we need LLVM to bootstrap later stages, so it becomes a
+  # build-time dependency too.
+  buildLlvmPackages, llvmPackages

 , # If enabled, GHC will be built with the GPL-free but slower integer-simple
  # library instead of the faster but GPLed integer-gmp library.
  enableIntegerSimple ? false, gmp ? null
+
+, # If enabled, use -fPIC when compiling static libs.
+  enableRelocatedStaticLibs ? targetPlatform != hostPlatform
+
+, # Whether to build dynamic libs for the standard library (on the target
+  # platform). Static libs are always built.
+  enableShared ?
+    !(targetPlatform.isDarwin
+      # On iOS, dynamic linking is not supported
+      && (targetPlatform.isAarch64 || targetPlatform.isArm))
 }:

 assert !enableIntegerSimple -> gmp != null;
@@ -22,8 +37,37 @@ let
  targetPrefix = stdenv.lib.optionalString
    (targetPlatform != hostPlatform)
    "${targetPlatform.config}-";
+
+  buildMK = ''
+    DYNAMIC_GHC_PROGRAMS = ${if enableShared then "YES" else "NO"}
+  '' + stdenv.lib.optionalString enableIntegerSimple ''
+    INTEGER_LIBRARY = integer-simple
+  '' + stdenv.lib.optionalString (targetPlatform != hostPlatform) ''
+    BuildFlavour = perf-cross
+    Stage1Only = YES
+    HADDOCK_DOCS = NO
+    BUILD_SPHINX_HTML = NO
+    BUILD_SPHINX_PDF = NO
+  '' + stdenv.lib.optionalString enableRelocatedStaticLibs ''
+    GhcLibHcOpts += -fPIC
+    GhcRtsHcOpts += -fPIC
+  '';
+
+  # Splicer will pull out correct variations
+  libDeps = platform: [ ncurses ]
+    ++ stdenv.lib.optional (!enableIntegerSimple) gmp
+    ++ stdenv.lib.optional (platform.libc != "glibc") libiconv;
+
+  toolsForTarget =
+    if hostPlatform == buildPlatform then
+      [ targetPackages.stdenv.cc ] ++ stdenv.lib.optional useLLVM llvmPackages.llvm
+    else assert targetPlatform == hostPlatform; # build != host == target
+      [ stdenv.cc ] ++ stdenv.lib.optional useLLVM buildLlvmPackages.llvm;
+
+  targetCC = builtins.head toolsForTarget;
+
 in
-stdenv.mkDerivation (rec {
+stdenv.mkDerivation rec {
  version = "8.2.2";
  name = "${targetPrefix}ghc-${version}";

@@ -32,42 +76,93 @@ stdenv.mkDerivation (rec {
    sha256 = "1z05vkpaj54xdypmaml50hgsdpw29dhbs2r7magx0cm199iw73mv";
  };

-  postPatch = "patchShebangs .";
-
-  preConfigure = ''
-    sed -i -e 's|-isysroot /Developer/SDKs/MacOSX10.5.sdk||' configure
-  '' + stdenv.lib.optionalString (!stdenv.isDarwin) ''
-    export NIX_LDFLAGS="$NIX_LDFLAGS -rpath $out/lib/ghc-${version}"
-  '' + stdenv.lib.optionalString stdenv.isDarwin ''
-    export NIX_LDFLAGS+=" -no_dtrace_dof"
-  '' + stdenv.lib.optionalString enableIntegerSimple ''
-    echo "INTEGER_LIBRARY=integer-simple" > mk/build.mk
-  '' + stdenv.lib.optionalString (targetPlatform != hostPlatform) ''
-    sed 's|#BuildFlavour  = quick-cross|BuildFlavour  = perf-cross|' mk/build.mk.sample > mk/build.mk
-  '';
-
-  buildInputs = [ alex autoconf automake ghc happy hscolour perl python3 sphinx ] ++ stdenv.lib.optionals (targetPlatform.isArm || targetPlatform.isAarch64) [ llvm_39 ];
-
  enableParallelBuilding = true;

-  configureFlags = [
-    "CC=${stdenv.cc}/bin/cc"
-    "--with-curses-includes=${ncurses.dev}/include" "--with-curses-libraries=${ncurses.out}/lib"
-    "--datadir=$doc/share/doc/ghc"
-  ] ++ stdenv.lib.optional (! enableIntegerSimple) [
-    "--with-gmp-includes=${gmp.dev}/include" "--with-gmp-libraries=${gmp.out}/lib"
-  ] ++ stdenv.lib.optional stdenv.isDarwin [
-    "--with-iconv-includes=${libiconv}/include" "--with-iconv-libraries=${libiconv}/lib"
-  ] ++ stdenv.lib.optional stdenv.isArm [
-    "LD=${stdenv.cc}/bin/ld.gold"
+  outputs = [ "out" "doc" ];
+
+  patches = [
+    (fetchpatch { # Fix STRIP to be substituted from configure
+      url = "https://git.haskell.org/ghc.git/commitdiff_plain/2fc8ce5f0c8c81771c26266ac0b150ca9b75c5f3";
+      sha256 = "03253ci40np1v6k0wmi4aypj3nmj3rdyvb1k6rwqipb30nfc719f";
+    })
  ];

+  postPatch = "patchShebangs .";
+
+  # GHC is a bit confused on its cross terminology.
+  preConfigure = ''
+    for env in $(env | grep '^TARGET_' | sed -E 's|\+?=.*||'); do
+      export "''${env#TARGET_}=''${!env}"
+    done
+    # GHC is a bit confused on its cross terminology, as these would normally be
+    # the *host* tools.
+    export CC="${targetCC}/bin/${targetCC.targetPrefix}cc"
+    export CXX="${targetCC}/bin/${targetCC.targetPrefix}cxx"
+    # Use gold to work around https://sourceware.org/bugzilla/show_bug.cgi?id=16177
+    export LD="${targetCC.bintools}/bin/${targetCC.bintools.targetPrefix}ld${stdenv.lib.optionalString targetPlatform.isArm ".gold"}"
+    export AS="${targetCC.bintools.bintools}/bin/${targetCC.bintools.targetPrefix}as"
+    export AR="${targetCC.bintools.bintools}/bin/${targetCC.bintools.targetPrefix}ar"
+    export NM="${targetCC.bintools.bintools}/bin/${targetCC.bintools.targetPrefix}nm"
+    export RANLIB="${targetCC.bintools.bintools}/bin/${targetCC.bintools.targetPrefix}ranlib"
+    export READELF="${targetCC.bintools.bintools}/bin/${targetCC.bintools.targetPrefix}readelf"
+    export STRIP="${targetCC.bintools.bintools}/bin/${targetCC.bintools.targetPrefix}strip"
+
+    echo -n "${buildMK}" > mk/build.mk
+    sed -i -e 's|-isysroot /Developer/SDKs/MacOSX10.5.sdk||' configure
+  '' + stdenv.lib.optionalString (!stdenv.isDarwin) ''
+    export NIX_LDFLAGS+=" -rpath $out/lib/ghc-${version}"
+  '' + stdenv.lib.optionalString stdenv.isDarwin ''
+    export NIX_LDFLAGS+=" -no_dtrace_dof"
+  '';
+
+  # TODO(@Ericson2314): Always pass "--target" and always prefix.
+  configurePlatforms = [ "build" "host" ]
+    ++ stdenv.lib.optional (targetPlatform != hostPlatform) "target";
+  # `--with` flags for libraries needed for RTS linker
+  configureFlags = [
+    "--datadir=$doc/share/doc/ghc"
+    "--with-curses-includes=${ncurses.dev}/include" "--with-curses-libraries=${ncurses.out}/lib"
+  ] ++ stdenv.lib.optional (targetPlatform == hostPlatform && ! enableIntegerSimple) [
+    "--with-gmp-includes=${gmp.dev}/include" "--with-gmp-libraries=${gmp.out}/lib"
+  ] ++ stdenv.lib.optional (targetPlatform == hostPlatform && hostPlatform.libc != "glibc") [
+    "--with-iconv-includes=${libiconv}/include" "--with-iconv-libraries=${libiconv}/lib"
+  ] ++ stdenv.lib.optionals (targetPlatform != hostPlatform) [
+    "--enable-bootstrap-with-devel-snapshot"
+  ] ++ stdenv.lib.optionals (targetPlatform.isArm) [
+    "CFLAGS=-fuse-ld=gold"
+    "CONF_GCC_LINKER_OPTS_STAGE1=-fuse-ld=gold"
+    "CONF_GCC_LINKER_OPTS_STAGE2=-fuse-ld=gold"
+  ] ++ stdenv.lib.optionals (targetPlatform.isDarwin && targetPlatform.isAarch64) [
+    # fix for iOS: https://www.reddit.com/r/haskell/comments/4ttdz1/building_an_osxi386_to_iosarm64_cross_compiler/d5qvd67/
+    "--disable-large-address-space"
+  ];
+
+  # Hack to make sure we never to the relaxation `$PATH` and hooks support for
+  # compatability. This will be replaced with something clearer in a future
+  # masss-rebuild.
+  crossConfig = true;
+
+  nativeBuildInputs = [ alex autoconf autoreconfHook automake ghc happy hscolour perl python3 sphinx ];
+
+  # For building runtime libs
+  depsBuildTarget = toolsForTarget;
+
+  buildInputs = libDeps hostPlatform;
+
+  propagatedBuildInputs = [ targetPackages.stdenv.cc ]
+    ++ stdenv.lib.optional useLLVM llvmPackages.llvm;
+
+  depsTargetTarget = map stdenv.lib.getDev (libDeps targetPlatform);
+  depsTargetTargetPropagated = map (stdenv.lib.getOutput "out") (libDeps targetPlatform);
+
  # required, because otherwise all symbols from HSffi.o are stripped, and
  # that in turn causes GHCi to abort
  stripDebugFlags = [ "-S" ] ++ stdenv.lib.optional (!targetPlatform.isDarwin) "--keep-file-symbols";

  checkTarget = "test";

+  # zsh and other shells are smart about `{ghc}` but bash isn't, and doesn't
+  # treat that as a unary `{x,y,z,..}` repetition.
  postInstall = ''
    paxmark m $out/lib/${name}/bin/${if targetPlatform != hostPlatform then "ghc" else "{ghc,haddock}"}

@@ -82,15 +177,13 @@ stdenv.mkDerivation (rec {
    done
  '';

-  outputs = [ "out" "doc" ];
-
  passthru = {
    inherit bootPkgs targetPrefix;
-  } // stdenv.lib.optionalAttrs (targetPlatform != buildPlatform) {
-    crossCompiler = selfPkgs.ghc.override {
-      cross = targetPlatform;
-      bootPkgs = selfPkgs;
-    };
+
+    inherit llvmPackages;
+
+    # Our Cabal compiler name
+    haskellCompilerName = "ghc";
  };

  meta = {
@@ -100,24 +193,4 @@ stdenv.mkDerivation (rec {
    inherit (ghc.meta) license platforms;
  };

-} // stdenv.lib.optionalAttrs (cross != null) {
-  configureFlags = [
-    "CC=${stdenv.cc}/bin/${cross.config}-cc"
-    "LD=${stdenv.cc.bintools}/bin/${cross.config}-ld"
-    "AR=${stdenv.cc.bintools}/bin/${cross.config}-ar"
-    "NM=${stdenv.cc.bintools}/bin/${cross.config}-nm"
-    "RANLIB=${stdenv.cc.bintools}/bin/${cross.config}-ranlib"
-    "--target=${cross.config}"
-    "--enable-bootstrap-with-devel-snapshot"
-  ] ++
-    # fix for iOS: https://www.reddit.com/r/haskell/comments/4ttdz1/building_an_osxi386_to_iosarm64_cross_compiler/d5qvd67/
-    stdenv.lib.optional (cross.config or null == "aarch64-apple-darwin14") "--disable-large-address-space";
-
-  configurePlatforms = [];
-
-  passthru = {
-    inherit bootPkgs cross;
-    cc = "${stdenv.cc}/bin/${cross.config}-cc";
-    ld = "${stdenv.cc}/bin/${cross.config}-ld";
-  };
-})
+}
--- a/pkgs/development/compilers/ghc/8.4.1.nix
+++ b/pkgs/development/compilers/ghc/8.4.1.nix
@@ -1,17 +1,29 @@
 { stdenv, targetPackages
 , buildPlatform, hostPlatform, targetPlatform
-, selfPkgs, cross ? null

 # build-tools
 , bootPkgs, alex, happy
 , autoconf, automake, coreutils, fetchgit, perl, python3

-, libiconv ? null, ncurses
+, libffi, libiconv ? null, ncurses
+
+, useLLVM ? !targetPlatform.isx86
+, # LLVM is conceptually a run-time-only depedendency, but for
+  # non-x86, we need LLVM to bootstrap later stages, so it becomes a
+  # build-time dependency too.
+  buildLlvmPackages, llvmPackages

 , # If enabled, GHC will be built with the GPL-free but slower integer-simple
  # library instead of the faster but GPLed integer-gmp library.
  enableIntegerSimple ? false, gmp ? null

+, # If enabled, use -fPIC when compiling static libs.
+  enableRelocatedStaticLibs ? targetPlatform != hostPlatform
+
+, # Whether to build dynamic libs for the standard library (on the target
+  # platform). Static libs are always built.
+  enableShared ? true
+
 , version ? "8.4.20180115"
 }:

@@ -20,60 +32,134 @@ assert !enableIntegerSimple -> gmp != null;
 let
  inherit (bootPkgs) ghc;

-  rev = "3e3a096885c0fcd0703edbeffb4e47f5cbd8f4cc";
-
  # TODO(@Ericson2314) Make unconditional
  targetPrefix = stdenv.lib.optionalString
    (targetPlatform != hostPlatform)
    "${targetPlatform.config}-";
+
+  buildMK = ''
+    DYNAMIC_GHC_PROGRAMS = ${if enableShared then "YES" else "NO"}
+  '' + stdenv.lib.optionalString enableIntegerSimple ''
+    INTEGER_LIBRARY = integer-simple
+  '' + stdenv.lib.optionalString (targetPlatform != hostPlatform) ''
+    BuildFlavour = perf-cross
+    Stage1Only = YES
+    HADDOCK_DOCS = NO
+    BUILD_SPHINX_HTML = NO
+    BUILD_SPHINX_PDF = NO
+  '' + stdenv.lib.optionalString enableRelocatedStaticLibs ''
+    GhcLibHcOpts += -fPIC
+    GhcRtsHcOpts += -fPIC
+  '';
+
+  # Splicer will pull out correct variations
+  libDeps = platform: [ ncurses ]
+    ++ stdenv.lib.optional (!enableIntegerSimple) gmp
+    ++ stdenv.lib.optional (platform.libc != "glibc") libiconv;
+
+  toolsForTarget =
+    if hostPlatform == buildPlatform then
+      [ targetPackages.stdenv.cc ] ++ stdenv.lib.optional useLLVM llvmPackages.llvm
+    else assert targetPlatform == hostPlatform; # build != host == target
+      [ stdenv.cc ] ++ stdenv.lib.optional useLLVM buildLlvmPackages.llvm;
+
+  targetCC = builtins.head toolsForTarget;
+
 in
-stdenv.mkDerivation (rec {
-  inherit version rev;
+stdenv.mkDerivation rec {
+  inherit version;
+  inherit (src) rev;
  name = "${targetPrefix}ghc-${version}";

  src = fetchgit {
    url = "git://git.haskell.org/ghc.git";
-    inherit rev;
+    rev = "3e3a096885c0fcd0703edbeffb4e47f5cbd8f4cc";
    sha256 = "06slymbsd7vsfp4hh40v7cxf7nmp0kvlni2wfq7ag5wlqh04slgs";
  };

+  enableParallelBuilding = true;
+
+  outputs = [ "out" "doc" ];
+
  postPatch = "patchShebangs .";

+  # GHC is a bit confused on its cross terminology.
  preConfigure = ''
+    for env in $(env | grep '^TARGET_' | sed -E 's|\+?=.*||'); do
+      export "''${env#TARGET_}=''${!env}"
+    done
+    # GHC is a bit confused on its cross terminology, as these would normally be
+    # the *host* tools.
+    export CC="${targetCC}/bin/${targetCC.targetPrefix}cc"
+    export CXX="${targetCC}/bin/${targetCC.targetPrefix}cxx"
+    # Use gold to work around https://sourceware.org/bugzilla/show_bug.cgi?id=16177
+    export LD="${targetCC.bintools}/bin/${targetCC.bintools.targetPrefix}ld${stdenv.lib.optionalString targetPlatform.isArm ".gold"}"
+    export AS="${targetCC.bintools.bintools}/bin/${targetCC.bintools.targetPrefix}as"
+    export AR="${targetCC.bintools.bintools}/bin/${targetCC.bintools.targetPrefix}ar"
+    export NM="${targetCC.bintools.bintools}/bin/${targetCC.bintools.targetPrefix}nm"
+    export RANLIB="${targetCC.bintools.bintools}/bin/${targetCC.bintools.targetPrefix}ranlib"
+    export READELF="${targetCC.bintools.bintools}/bin/${targetCC.bintools.targetPrefix}readelf"
+    export STRIP="${targetCC.bintools.bintools}/bin/${targetCC.bintools.targetPrefix}strip"
+
+    echo -n "${buildMK}" > mk/build.mk
    echo ${version} >VERSION
-    echo ${rev} >GIT_COMMIT_ID
+    echo ${src.rev} >GIT_COMMIT_ID
    ./boot
    sed -i -e 's|-isysroot /Developer/SDKs/MacOSX10.5.sdk||' configure
  '' + stdenv.lib.optionalString (!stdenv.isDarwin) ''
-    export NIX_LDFLAGS="$NIX_LDFLAGS -rpath $out/lib/ghc-${version}"
+    export NIX_LDFLAGS+=" -rpath $out/lib/ghc-${version}"
  '' + stdenv.lib.optionalString stdenv.isDarwin ''
    export NIX_LDFLAGS+=" -no_dtrace_dof"
-  '' + stdenv.lib.optionalString enableIntegerSimple ''
-    echo "INTEGER_LIBRARY=integer-simple" > mk/build.mk
-  '' + stdenv.lib.optionalString (targetPlatform != hostPlatform) ''
-    sed 's|#BuildFlavour  = quick-cross|BuildFlavour  = perf-cross|' mk/build.mk.sample > mk/build.mk
  '';

-  buildInputs = [ ghc perl autoconf automake happy alex python3 ];
-
-  enableParallelBuilding = true;
-
+  # TODO(@Ericson2314): Always pass "--target" and always prefix.
+  configurePlatforms = [ "build" "host" ]
+    ++ stdenv.lib.optional (targetPlatform != hostPlatform) "target";
+  # `--with` flags for libraries needed for RTS linker
  configureFlags = [
-    "CC=${stdenv.cc}/bin/cc"
-    "--with-curses-includes=${ncurses.dev}/include" "--with-curses-libraries=${ncurses.out}/lib"
    "--datadir=$doc/share/doc/ghc"
-  ] ++ stdenv.lib.optional (! enableIntegerSimple) [
+    "--with-curses-includes=${ncurses.dev}/include" "--with-curses-libraries=${ncurses.out}/lib"
+  ] ++ stdenv.lib.optional (targetPlatform == hostPlatform && ! enableIntegerSimple) [
    "--with-gmp-includes=${gmp.dev}/include" "--with-gmp-libraries=${gmp.out}/lib"
-  ] ++ stdenv.lib.optional stdenv.isDarwin [
+  ] ++ stdenv.lib.optional (targetPlatform == hostPlatform && hostPlatform.libc != "glibc") [
    "--with-iconv-includes=${libiconv}/include" "--with-iconv-libraries=${libiconv}/lib"
+  ] ++ stdenv.lib.optionals (targetPlatform != hostPlatform) [
+    "--enable-bootstrap-with-devel-snapshot"
+  ] ++ stdenv.lib.optionals (targetPlatform.isArm) [
+    "CFLAGS=-fuse-ld=gold"
+    "CONF_GCC_LINKER_OPTS_STAGE1=-fuse-ld=gold"
+    "CONF_GCC_LINKER_OPTS_STAGE2=-fuse-ld=gold"
+  ] ++ stdenv.lib.optionals (targetPlatform.isDarwin && targetPlatform.isAarch64) [
+    # fix for iOS: https://www.reddit.com/r/haskell/comments/4ttdz1/building_an_osxi386_to_iosarm64_cross_compiler/d5qvd67/
+    "--disable-large-address-space"
  ];

+  # Hack to make sure we never to the relaxation `$PATH` and hooks support for
+  # compatability. This will be replaced with something clearer in a future
+  # masss-rebuild.
+  crossConfig = true;
+
+  nativeBuildInputs = [ ghc perl autoconf automake happy alex python3 ];
+
+  # For building runtime libs
+  depsBuildTarget = toolsForTarget;
+
+  buildInputs = libDeps hostPlatform;
+
+  propagatedBuildInputs = [ targetPackages.stdenv.cc ]
+    ++ stdenv.lib.optional useLLVM llvmPackages.llvm;
+
+  depsTargetTarget = map stdenv.lib.getDev (libDeps targetPlatform);
+  depsTargetTargetPropagated = map (stdenv.lib.getOutput "out") (libDeps targetPlatform);
+
  # required, because otherwise all symbols from HSffi.o are stripped, and
  # that in turn causes GHCi to abort
  stripDebugFlags = [ "-S" ] ++ stdenv.lib.optional (!targetPlatform.isDarwin) "--keep-file-symbols";

  checkTarget = "test";

+  # zsh and other shells are smart about `{ghc}` but bash isn't, and doesn't
+  # treat that as a unary `{x,y,z,..}` repetition.
  postInstall = ''
    paxmark m $out/lib/${name}/bin/${if targetPlatform != hostPlatform then "ghc" else "{ghc,haddock}"}

@@ -88,15 +174,13 @@ stdenv.mkDerivation (rec {
    done
  '';

-  outputs = [ "out" "doc" ];
-
  passthru = {
    inherit bootPkgs targetPrefix;
-  } // stdenv.lib.optionalAttrs (targetPlatform != buildPlatform) {
-    crossCompiler = selfPkgs.ghc.override {
-      cross = targetPlatform;
-      bootPkgs = selfPkgs;
-    };
+
+    inherit llvmPackages;
+
+    # Our Cabal compiler name
+    haskellCompilerName = "ghc";
  };

  meta = {
@@ -106,24 +190,4 @@ stdenv.mkDerivation (rec {
    inherit (ghc.meta) license platforms;
  };

-} // stdenv.lib.optionalAttrs (cross != null) {
-  configureFlags = [
-    "CC=${stdenv.cc}/bin/${cross.config}-cc"
-    "LD=${stdenv.cc.bintools}/bin/${cross.config}-ld"
-    "AR=${stdenv.cc.bintools}/bin/${cross.config}-ar"
-    "NM=${stdenv.cc.bintools}/bin/${cross.config}-nm"
-    "RANLIB=${stdenv.cc.bintools}/bin/${cross.config}-ranlib"
-    "--target=${cross.config}"
-    "--enable-bootstrap-with-devel-snapshot"
-  ] ++
-    # fix for iOS: https://www.reddit.com/r/haskell/comments/4ttdz1/building_an_osxi386_to_iosarm64_cross_compiler/d5qvd67/
-    stdenv.lib.optional (cross.config or null == "aarch64-apple-darwin14") "--disable-large-address-space";
-
-  configurePlatforms = [];
-
-  passthru = {
-    inherit bootPkgs cross;
-    cc = "${stdenv.cc}/bin/${cross.config}-cc";
-    ld = "${stdenv.cc}/bin/${cross.config}-ld";
-  };
-})
+}
--- a/pkgs/development/compilers/ghc/head.nix
+++ b/pkgs/development/compilers/ghc/head.nix
@@ -1,18 +1,30 @@
 { stdenv, targetPackages
 , buildPlatform, hostPlatform, targetPlatform
-, selfPkgs, cross ? null

 # build-tools
 , bootPkgs, alex, happy
 , autoconf, automake, coreutils, fetchgit, perl, python3

-, libiconv ? null, ncurses
+, libffi, libiconv ? null, ncurses
+
+, useLLVM ? !targetPlatform.isx86
+, # LLVM is conceptually a run-time-only depedendency, but for
+  # non-x86, we need LLVM to bootstrap later stages, so it becomes a
+  # build-time dependency too.
+  buildLlvmPackages, llvmPackages

 , # If enabled, GHC will be built with the GPL-free but slower integer-simple
  # library instead of the faster but GPLed integer-gmp library.
  enableIntegerSimple ? false, gmp ? null

-, version ? "8.5.20171209"
+, # If enabled, use -fPIC when compiling static libs.
+  enableRelocatedStaticLibs ? targetPlatform != hostPlatform
+
+, # Whether to build dynamic libs for the standard library (on the target
+  # platform). Static libs are always built.
+  enableShared ? true
+
+, version ? "8.5.20180118"
 }:

 assert !enableIntegerSimple -> gmp != null;
@@ -20,60 +32,134 @@ assert !enableIntegerSimple -> gmp != null;
 let
  inherit (bootPkgs) ghc;

-  rev = "4335c07ca7e64624819b22644d7591853826bd75";
-
  # TODO(@Ericson2314) Make unconditional
  targetPrefix = stdenv.lib.optionalString
    (targetPlatform != hostPlatform)
    "${targetPlatform.config}-";
+
+  buildMK = ''
+    DYNAMIC_GHC_PROGRAMS = ${if enableShared then "YES" else "NO"}
+  '' + stdenv.lib.optionalString enableIntegerSimple ''
+    INTEGER_LIBRARY = integer-simple
+  '' + stdenv.lib.optionalString (targetPlatform != hostPlatform) ''
+    BuildFlavour = perf-cross
+    Stage1Only = YES
+    HADDOCK_DOCS = NO
+    BUILD_SPHINX_HTML = NO
+    BUILD_SPHINX_PDF = NO
+  '' + stdenv.lib.optionalString enableRelocatedStaticLibs ''
+    GhcLibHcOpts += -fPIC
+    GhcRtsHcOpts += -fPIC
+  '';
+
+  # Splicer will pull out correct variations
+  libDeps = platform: [ ncurses ]
+    ++ stdenv.lib.optional (!enableIntegerSimple) gmp
+    ++ stdenv.lib.optional (platform.libc != "glibc") libiconv;
+
+  toolsForTarget =
+    if hostPlatform == buildPlatform then
+      [ targetPackages.stdenv.cc ] ++ stdenv.lib.optional useLLVM llvmPackages.llvm
+    else assert targetPlatform == hostPlatform; # build != host == target
+      [ stdenv.cc ] ++ stdenv.lib.optional useLLVM buildLlvmPackages.llvm;
+
+  targetCC = builtins.head toolsForTarget;
+
 in
-stdenv.mkDerivation (rec {
-  inherit version rev;
+stdenv.mkDerivation rec {
+  inherit version;
+  inherit (src) rev;
  name = "${targetPrefix}ghc-${version}";

  src = fetchgit {
    url = "git://git.haskell.org/ghc.git";
-    inherit rev;
-    sha256 = "19csad94sk0bw2nj97ppmnwh4c193jg0jmg5w2sx9rqm9ih4yg85";
+    rev = "e1d4140be4d2a1508015093b69e1ef53516e1eb6";
+    sha256 = "1gdcr10dd968d40qgljdwx9vfkva3yrvjm9a4nis7whaaac3ag58";
  };

-  postPatch = "patchShebangs .";
-
-  preConfigure = ''
-    echo ${version} >VERSION
-    echo ${rev} >GIT_COMMIT_ID
-    ./boot
-    sed -i -e 's|-isysroot /Developer/SDKs/MacOSX10.5.sdk||' configure
-  '' + stdenv.lib.optionalString (!stdenv.isDarwin) ''
-    export NIX_LDFLAGS="$NIX_LDFLAGS -rpath $out/lib/ghc-${version}"
-  '' + stdenv.lib.optionalString stdenv.isDarwin ''
-    export NIX_LDFLAGS+=" -no_dtrace_dof"
-  '' + stdenv.lib.optionalString enableIntegerSimple ''
-    echo "INTEGER_LIBRARY=integer-simple" > mk/build.mk
-  '' + stdenv.lib.optionalString (targetPlatform != hostPlatform) ''
-    sed 's|#BuildFlavour  = quick-cross|BuildFlavour  = perf-cross|' mk/build.mk.sample > mk/build.mk
-  '';
-
-  buildInputs = [ ghc perl autoconf automake happy alex python3 ];
-
  enableParallelBuilding = true;

+  outputs = [ "out" "doc" ];
+
+  postPatch = "patchShebangs .";
+
+  # GHC is a bit confused on its cross terminology.
+  preConfigure = ''
+    for env in $(env | grep '^TARGET_' | sed -E 's|\+?=.*||'); do
+      export "''${env#TARGET_}=''${!env}"
+    done
+    # GHC is a bit confused on its cross terminology, as these would normally be
+    # the *host* tools.
+    export CC="${targetCC}/bin/${targetCC.targetPrefix}cc"
+    export CXX="${targetCC}/bin/${targetCC.targetPrefix}cxx"
+    # Use gold to work around https://sourceware.org/bugzilla/show_bug.cgi?id=16177
+    export LD="${targetCC.bintools}/bin/${targetCC.bintools.targetPrefix}ld${stdenv.lib.optionalString targetPlatform.isArm ".gold"}"
+    export AS="${targetCC.bintools.bintools}/bin/${targetCC.bintools.targetPrefix}as"
+    export AR="${targetCC.bintools.bintools}/bin/${targetCC.bintools.targetPrefix}ar"
+    export NM="${targetCC.bintools.bintools}/bin/${targetCC.bintools.targetPrefix}nm"
+    export RANLIB="${targetCC.bintools.bintools}/bin/${targetCC.bintools.targetPrefix}ranlib"
+    export READELF="${targetCC.bintools.bintools}/bin/${targetCC.bintools.targetPrefix}readelf"
+    export STRIP="${targetCC.bintools.bintools}/bin/${targetCC.bintools.targetPrefix}strip"
+
+    echo -n "${buildMK}" > mk/build.mk
+    echo ${version} >VERSION
+    echo ${src.rev} >GIT_COMMIT_ID
+    ./boot
+    sed -i -e 's|-isysroot /Developer/SDKs/MacOSX10.5.sdk||' configure
+  '' + stdenv.lib.optionalString (!stdenv.isDarwin) ''
+    export NIX_LDFLAGS+=" -rpath $out/lib/ghc-${version}"
+  '' + stdenv.lib.optionalString stdenv.isDarwin ''
+    export NIX_LDFLAGS+=" -no_dtrace_dof"
+  '';
+
+  # TODO(@Ericson2314): Always pass "--target" and always prefix.
+  configurePlatforms = [ "build" "host" ]
+    ++ stdenv.lib.optional (targetPlatform != hostPlatform) "target";
+  # `--with` flags for libraries needed for RTS linker
  configureFlags = [
-    "CC=${stdenv.cc}/bin/cc"
-    "--with-curses-includes=${ncurses.dev}/include" "--with-curses-libraries=${ncurses.out}/lib"
    "--datadir=$doc/share/doc/ghc"
-  ] ++ stdenv.lib.optional (! enableIntegerSimple) [
+    "--with-curses-includes=${ncurses.dev}/include" "--with-curses-libraries=${ncurses.out}/lib"
+  ] ++ stdenv.lib.optional (targetPlatform == hostPlatform && ! enableIntegerSimple) [
    "--with-gmp-includes=${gmp.dev}/include" "--with-gmp-libraries=${gmp.out}/lib"
-  ] ++ stdenv.lib.optional stdenv.isDarwin [
+  ] ++ stdenv.lib.optional (targetPlatform == hostPlatform && hostPlatform.libc != "glibc") [
    "--with-iconv-includes=${libiconv}/include" "--with-iconv-libraries=${libiconv}/lib"
+  ] ++ stdenv.lib.optionals (targetPlatform != hostPlatform) [
+    "--enable-bootstrap-with-devel-snapshot"
+  ] ++ stdenv.lib.optionals (targetPlatform.isArm) [
+    "CFLAGS=-fuse-ld=gold"
+    "CONF_GCC_LINKER_OPTS_STAGE1=-fuse-ld=gold"
+    "CONF_GCC_LINKER_OPTS_STAGE2=-fuse-ld=gold"
+  ] ++ stdenv.lib.optionals (targetPlatform.isDarwin && targetPlatform.isAarch64) [
+    # fix for iOS: https://www.reddit.com/r/haskell/comments/4ttdz1/building_an_osxi386_to_iosarm64_cross_compiler/d5qvd67/
+    "--disable-large-address-space"
  ];

+  # Hack to make sure we never to the relaxation `$PATH` and hooks support for
+  # compatability. This will be replaced with something clearer in a future
+  # masss-rebuild.
+  crossConfig = true;
+
+  nativeBuildInputs = [ ghc perl autoconf automake happy alex python3 ];
+
+  # For building runtime libs
+  depsBuildTarget = toolsForTarget;
+
+  buildInputs = libDeps hostPlatform;
+
+  propagatedBuildInputs = [ targetPackages.stdenv.cc ]
+    ++ stdenv.lib.optional useLLVM llvmPackages.llvm;
+
+  depsTargetTarget = map stdenv.lib.getDev (libDeps targetPlatform);
+  depsTargetTargetPropagated = map (stdenv.lib.getOutput "out") (libDeps targetPlatform);
+
  # required, because otherwise all symbols from HSffi.o are stripped, and
  # that in turn causes GHCi to abort
  stripDebugFlags = [ "-S" ] ++ stdenv.lib.optional (!targetPlatform.isDarwin) "--keep-file-symbols";

  checkTarget = "test";

+  # zsh and other shells are smart about `{ghc}` but bash isn't, and doesn't
+  # treat that as a unary `{x,y,z,..}` repetition.
  postInstall = ''
    paxmark m $out/lib/${name}/bin/${if targetPlatform != hostPlatform then "ghc" else "{ghc,haddock}"}

@@ -88,15 +174,13 @@ stdenv.mkDerivation (rec {
    done
  '';

-  outputs = [ "out" "doc" ];
-
  passthru = {
    inherit bootPkgs targetPrefix;
-  } // stdenv.lib.optionalAttrs (targetPlatform != buildPlatform) {
-    crossCompiler = selfPkgs.ghc.override {
-      cross = targetPlatform;
-      bootPkgs = selfPkgs;
-    };
+
+    inherit llvmPackages;
+
+    # Our Cabal compiler name
+    haskellCompilerName = "ghc";
  };

  meta = {
@@ -106,24 +190,4 @@ stdenv.mkDerivation (rec {
    inherit (ghc.meta) license platforms;
  };

-} // stdenv.lib.optionalAttrs (cross != null) {
-  configureFlags = [
-    "CC=${stdenv.cc}/bin/${cross.config}-cc"
-    "LD=${stdenv.cc.bintools}/bin/${cross.config}-ld"
-    "AR=${stdenv.cc.bintools}/bin/${cross.config}-ar"
-    "NM=${stdenv.cc.bintools}/bin/${cross.config}-nm"
-    "RANLIB=${stdenv.cc.bintools}/bin/${cross.config}-ranlib"
-    "--target=${cross.config}"
-    "--enable-bootstrap-with-devel-snapshot"
-  ] ++
-    # fix for iOS: https://www.reddit.com/r/haskell/comments/4ttdz1/building_an_osxi386_to_iosarm64_cross_compiler/d5qvd67/
-    stdenv.lib.optional (cross.config or null == "aarch64-apple-darwin14") "--disable-large-address-space";
-
-  configurePlatforms = [];
-
-  passthru = {
-    inherit bootPkgs cross;
-    cc = "${stdenv.cc}/bin/${cross.config}-cc";
-    ld = "${stdenv.cc}/bin/${cross.config}-ld";
-  };
-})
+}