{ lib, stdenv, callPackage, withLinuxHeaders ? true, profilingLibraries ? false
, withGd ? false, pkgsBuildBuild, libgcc }:

let
  gdCflags = [
    "-Wno-error=stringop-truncation"
    "-Wno-error=missing-attributes"
    "-Wno-error=array-bounds"
  ];

in (callPackage ./common.nix { inherit stdenv; } {
  inherit withLinuxHeaders withGd profilingLibraries;
  pname = "glibc" + lib.optionalString withGd "-gd"
    + lib.optionalString (stdenv.cc.isGNU && libgcc == null) "-nolibgcc";
}).overrideAttrs (previousAttrs: {

  # Note:
  # Things you write here override, and do not add to,
  # the values in `common.nix`.
  # (For example, if you define `patches = [...]` here, it will
  # override the patches in `common.nix` -- so instead you should
  # write `patches = (previousAttrs.patches or []) ++ [ ... ]`.

  NIX_NO_SELF_RPATH = true;

  postConfigure = ''
    # Hack: get rid of the `-static' flag set by the bootstrap stdenv.
    # This has to be done *after* `configure' because it builds some
    # test binaries.
    export NIX_CFLAGS_LINK=
    export NIX_LDFLAGS_BEFORE=

    export NIX_DONT_SET_RPATH=1
    unset CFLAGS

    # Apparently --bindir is not respected.
    makeFlagsArray+=("bindir=$bin/bin" "sbindir=$bin/sbin" "rootsbindir=$bin/sbin")
  '' + lib.optionalString stdenv.buildPlatform.isDarwin ''
    # ld-wrapper will otherwise attempt to inject CoreFoundation into ld-linux's RUNPATH
    export NIX_COREFOUNDATION_RPATH=
  '';

  # The pie, stackprotector and fortify hardening flags are autodetected by
  # glibc and enabled by default if supported. Setting it for every gcc
  # invocation does not work.
  hardeningDisable = [ "fortify" "pie" "stackprotector" ];

  env = (previousAttrs.env or { }) // {
    NIX_CFLAGS_COMPILE = (previousAttrs.env.NIX_CFLAGS_COMPILE or "")
      + lib.concatStringsSep " " (builtins.concatLists [
        (lib.optionals withGd gdCflags)
        # Fix -Werror build failure when building glibc with musl with GCC >= 8, see:
        # https://github.com/NixOS/nixpkgs/pull/68244#issuecomment-544307798
        (lib.optional stdenv.hostPlatform.isMusl "-Wno-error=attribute-alias")
        (lib.optionals ((stdenv.hostPlatform != stdenv.buildPlatform)
          || stdenv.hostPlatform.isMusl) [
            # Ignore "error: '__EI___errno_location' specifies less restrictive attributes than its target '__errno_location'"
            # New warning as of GCC 9
            # Same for musl: https://github.com/NixOS/nixpkgs/issues/78805
            "-Wno-error=missing-attributes"
          ])
        (lib.optionals (stdenv.hostPlatform.isPower64) [
          # Do not complain about the Processor Specific ABI (i.e. the
          # choice to use IEEE-standard `long double`).  We pass this
          # flag in order to mute a `-Werror=psabi` passed by glibc;
          # hopefully future glibc releases will not pass that flag.
          "-Wno-error=psabi"
        ])
      ]);
  };

  # glibc needs to `dlopen()` `libgcc_s.so` but does not link
  # against it.  Furthermore, glibc doesn't use the ordinary
  # `dlopen()` call to do this; instead it uses one which ignores
  # most paths:
  #
  #   https://sourceware.org/legacy-ml/libc-help/2013-11/msg00026.html
  #
  # In order to get it to not ignore `libgcc_s.so`, we have to add its path to
  # `user-defined-trusted-dirs`:
  #
  #   https://sourceware.org/git/?p=glibc.git;a=blob;f=elf/Makefile;h=b509b3eada1fb77bf81e2a0ca5740b94ad185764#l1355
  #
  # Conveniently, this will also inform Nix of the fact that glibc depends on
  # gcc.libgcc, since the path will be embedded in the resulting binary.
  #
  makeFlags = (previousAttrs.makeFlags or [ ]) ++ lib.optionals (libgcc != null)
    [ "user-defined-trusted-dirs=${libgcc}/lib" ];

  postInstall = previousAttrs.postInstall
    + (if stdenv.buildPlatform.canExecute stdenv.hostPlatform then ''
      echo SUPPORTED-LOCALES=C.UTF-8/UTF-8 > ../glibc-2*/localedata/SUPPORTED
      make -j''${NIX_BUILD_CORES:-1} localedata/install-locales
    '' else
      lib.optionalString stdenv.buildPlatform.isLinux
      # This is based on http://www.linuxfromscratch.org/lfs/view/development/chapter06/glibc.html
      # Instead of using their patch to build a build-native localedef,
      # we simply use the one from pkgsBuildBuild.
      #
      # Note that we can't use pkgsBuildHost (aka buildPackages) here, because
      # that will cause an eval-time infinite recursion: "buildPackages.glibc
      # depended on buildPackages.libgcc, which, since it's GCC, depends on the
      # target's bintools, which depend on the target's glibc, which, again,
      # depends on buildPackages.glibc, causing an infinute recursion when
      # evaluating buildPackages.glibc when glibc hasn't come from stdenv
      # (e.g. on musl)." https://github.com/NixOS/nixpkgs/pull/259964
      ''
        pushd ../glibc-2*/localedata
        export I18NPATH=$PWD GCONV_PATH=$PWD/../iconvdata
        mkdir -p $NIX_BUILD_TOP/${pkgsBuildBuild.glibc}/lib/locale
        ${lib.getBin pkgsBuildBuild.glibc}/bin/localedef \
          --alias-file=../intl/locale.alias \
          -i locales/C \
          -f charmaps/UTF-8 \
          --prefix $NIX_BUILD_TOP \
          ${
            if stdenv.hostPlatform.parsed.cpu.significantByte.name
            == "littleEndian" then
              "--little-endian"
            else
              "--big-endian"
          } \
          C.UTF-8
        cp -r $NIX_BUILD_TOP/${pkgsBuildBuild.glibc}/lib/locale $out/lib
        popd
      '') + ''

        test -f $out/etc/ld.so.cache && rm $out/etc/ld.so.cache

        if test -n "$linuxHeaders"; then
            # Include the Linux kernel headers in Glibc, except the `scsi'
            # subdirectory, which Glibc provides itself.
            (cd $dev/include && \
             ln -sv $(ls -d $linuxHeaders/include/* | grep -v scsi\$) .)
        fi

        # Fix for NIXOS-54 (ldd not working on x86_64).  Make a symlink
        # "lib64" to "lib".
        if test -n "$is64bit"; then
            ln -s lib $out/lib64
        fi

        # Get rid of more unnecessary stuff.
        rm -rf $out/var $bin/bin/sln

        # Backwards-compatibility to fix e.g.
        # "configure: error: Pthreads are required to build libgomp" during `gcc`-build
        # because it's not actually needed anymore to link against `pthreads` since
        # it's now part of `libc.so.6` itself, but the gcc build breaks if
        # this doesn't work.
        ln -sf $out/lib/libpthread.so.0 $out/lib/libpthread.so
        ln -sf $out/lib/librt.so.1 $out/lib/librt.so
        ln -sf $out/lib/libdl.so.2 $out/lib/libdl.so
        test -f $out/lib/libutil.so.1 && ln -sf $out/lib/libutil.so.1 $out/lib/libutil.so
        touch $out/lib/libpthread.a

        # Put libraries for static linking in a separate output.  Note
        # that libc_nonshared.a and libpthread_nonshared.a are required
        # for dynamically-linked applications.
        mkdir -p $static/lib
        mv $out/lib/*.a $static/lib
        mv $static/lib/lib*_nonshared.a $out/lib
        # If libutil.so.1 is missing, libutil.a is required.
        test -f $out/lib/libutil.so.1 || mv $static/lib/libutil.a $out/lib
        # Some of *.a files are linker scripts where moving broke the paths.
        sed "/^GROUP/s|$out/lib/lib|$static/lib/lib|g" \
          -i "$static"/lib/*.a

        # Work around a Nix bug: hard links across outputs cause a build failure.
        cp $bin/bin/getconf $bin/bin/getconf_
        mv $bin/bin/getconf_ $bin/bin/getconf
      '';

  separateDebugInfo = true;

  passthru = (previousAttrs.passthru or { })
    // lib.optionalAttrs (libgcc != null) { inherit libgcc; };

  meta = (previousAttrs.meta or { }) // { description = "The GNU C Library"; };
})