daml/nix/with-packages-wrapper.nix
Digital Asset GmbH 05e691f558 open-sourcing daml
2019-04-04 09:33:38 +01:00

133 lines
5.5 KiB
Nix

# This is based on the version that is in nixpkgs (commit 5d19e3e78fb89f01e7fb48acc341687e54d6888f)
# but we patch ghcWithPackages so that it provides package config files with extra-libraries
# instead of hs-libraries which is required for GHCi and TH to pick up static Haskell libs.
{ lib, targetPlatform, ghc, llvmPackages, packages, symlinkJoin, makeWrapper
, withLLVM ? false
, postBuild ? ""
, ghcLibdir ? null # only used by ghcjs, when resolving plugins
}:
assert ghcLibdir != null -> (ghc.isGhcjs or false);
# This wrapper works only with GHC 6.12 or later.
assert lib.versionOlder "6.12" ghc.version || ghc.isGhcjs || ghc.isHaLVM;
# It's probably a good idea to include the library "ghc-paths" in the
# compiler environment, because we have a specially patched version of
# that package in Nix that honors these environment variables
#
# NIX_GHC
# NIX_GHCPKG
# NIX_GHC_DOCDIR
# NIX_GHC_LIBDIR
#
# instead of hard-coding the paths. The wrapper sets these variables
# appropriately to configure ghc-paths to point back to the wrapper
# instead of to the pristine GHC package, which doesn't know any of the
# additional libraries.
#
# A good way to import the environment set by the wrapper below into
# your shell is to add the following snippet to your ~/.bashrc:
#
# if [ -e ~/.nix-profile/bin/ghc ]; then
# eval $(grep export ~/.nix-profile/bin/ghc)
# fi
let
isGhcjs = ghc.isGhcjs or false;
isHaLVM = ghc.isHaLVM or false;
ghc761OrLater = isGhcjs || isHaLVM || lib.versionOlder "7.6.1" ghc.version;
packageDBFlag = if ghc761OrLater then "--global-package-db" else "--global-conf";
ghcCommand' = if isGhcjs then "ghcjs" else "ghc";
ghcCommand = "${ghc.targetPrefix}${ghcCommand'}";
ghcCommandCaps= lib.toUpper ghcCommand';
libDir = if isHaLVM then "$out/lib/HaLVM-${ghc.version}" else "$out/lib/${ghcCommand}-${ghc.version}";
docDir = "$out/share/doc/ghc/html";
packageCfgDir = "${libDir}/package.conf.d";
paths = lib.filter (x: x ? isHaskellLibrary) (lib.closePropagation packages);
hasLibraries = lib.any (x: x.isHaskellLibrary) paths;
# CLang is needed on Darwin for -fllvm to work:
# https://downloads.haskell.org/~ghc/latest/docs/html/users_guide/codegens.html#llvm-code-generator-fllvm
llvm = lib.makeBinPath
([ llvmPackages.llvm ]
++ lib.optional targetPlatform.isDarwin llvmPackages.clang);
in
if paths == [] && !withLLVM then ghc else
symlinkJoin {
# this makes computing paths from the name attribute impossible;
# if such a feature is needed, the real compiler name should be saved
# as a dedicated drv attribute, like `compiler-name`
name = ghc.name + "-with-packages";
preferLocalBuild = false;
allowSubstitutes = true;
paths = paths ++ [ghc];
postBuild = ''
. ${makeWrapper}/nix-support/setup-hook
# wrap compiler executables with correct env variables
for prg in ${ghcCommand} ${ghcCommand}i ${ghcCommand}-${ghc.version} ${ghcCommand}i-${ghc.version}; do
if [[ -x "${ghc}/bin/$prg" ]]; then
rm -f $out/bin/$prg
makeWrapper ${ghc}/bin/$prg $out/bin/$prg \
--add-flags '"-B$NIX_${ghcCommandCaps}_LIBDIR"' \
--set "NIX_${ghcCommandCaps}" "$out/bin/${ghcCommand}" \
--set "NIX_${ghcCommandCaps}PKG" "$out/bin/${ghcCommand}-pkg" \
--set "NIX_${ghcCommandCaps}_DOCDIR" "${docDir}" \
--set "NIX_${ghcCommandCaps}_LIBDIR" "${libDir}" \
${lib.optionalString (ghc.isGhcjs or false)
''--set NODE_PATH "${ghc.socket-io}/lib/node_modules"''
} \
${lib.optionalString withLLVM ''--prefix "PATH" ":" "${llvm}"''}
fi
done
for prg in runghc runhaskell; do
if [[ -x "${ghc}/bin/$prg" ]]; then
rm -f $out/bin/$prg
makeWrapper ${ghc}/bin/$prg $out/bin/$prg \
--add-flags "-f $out/bin/${ghcCommand}" \
--set "NIX_${ghcCommandCaps}" "$out/bin/${ghcCommand}" \
--set "NIX_${ghcCommandCaps}PKG" "$out/bin/${ghcCommand}-pkg" \
--set "NIX_${ghcCommandCaps}_DOCDIR" "${docDir}" \
--set "NIX_${ghcCommandCaps}_LIBDIR" "${libDir}"
fi
done
for prg in ${ghcCommand}-pkg ${ghcCommand}-pkg-${ghc.version}; do
if [[ -x "${ghc}/bin/$prg" ]]; then
rm -f $out/bin/$prg
makeWrapper ${ghc}/bin/$prg $out/bin/$prg --add-flags "${packageDBFlag}=${packageCfgDir}"
fi
done
'' + ''
# Patch the package configs shipped with GHC so that it treats Haskell
# libraries like C libraries which allows linking against static Haskell libs from
# TH and GHCi.
local packageConfDir="$out/lib/${ghc.name}/package.conf.d";
for f in $packageConfDir/*.conf; do
filename="$(basename $f)"
if [ "$filename" != "rts.conf" ]; then
cp $f $f-tmp
rm $f
sed "s/hs-libraries/extra-libraries/g" $f-tmp > $f
rm $f-tmp
fi
done
'' + ''
$out/bin/${ghcCommand}-pkg recache
${# ghcjs will read the ghc_libdir file when resolving plugins.
lib.optionalString (isGhcjs && ghcLibdir != null) ''
mkdir -p "${libDir}"
rm -f "${libDir}/ghc_libdir"
printf '%s' '${ghcLibdir}' > "${libDir}/ghc_libdir"
''}
$out/bin/${ghcCommand}-pkg check
'' + postBuild;
passthru = {
preferLocalBuild = true;
inherit (ghc) version meta;
};
}