libgcc: Init at 7.3.0

This will be very useful for bootstrapping, eventually.

pkgs/development/libraries/gcc/libgcc/default.nix

@@ -0,0 +1,152 @@
+{ stdenvNoLibs, buildPackages, buildPlatform, hostPlatform
+, gcc, glibc
+, libiberty
+}:
+
+stdenvNoLibs.mkDerivation rec {
+  name = "libgcc-${version}";
+  inherit (gcc.cc) src version;
+
+  outputs = [ "out" "dev" ];
+
+  strictDeps = true;
+  depsBuildBuild = [ buildPackages.stdenv.cc ];
+  nativeBuildInputs = [ libiberty ];
+
+  postUnpack = ''
+    mkdir -p ./build
+    buildRoot=$(readlink -e "./build")
+  '';
+
+  postPatch = ''
+    sourceRoot=$(readlink -e "./libgcc")
+  '';
+
+  preConfigure = ''
+    cd "$buildRoot"
+  ''
+
+  # Drop in libiberty, as external builds are not expected
+  + ''
+    (
+      mkdir -p build-${buildPlatform.config}/libiberty/
+      cd build-${buildPlatform.config}/libiberty/
+      ln -s ${buildPackages.libiberty}/lib/libiberty.a ./
+    )
+  ''
+  # A few misc bits of gcc need to be built.
+  #
+  #  - We "shift" the tools over to fake platforms perspective from the previous
+  #    stage.
+  #
+  #  - We define GENERATOR_FILE so nothing bothers looking for GNU GMP.
+  #
+  #  - We remove the `libgcc.mvar` deps so that the bootstrap xgcc isn't built.
+  + ''
+    mkdir -p "$buildRoot/gcc"
+    cd "$buildRoot/gcc"
+    (
+      export AS_FOR_BUILD=${buildPackages.stdenv.cc}/bin/$AS_FOR_BUILD
+      export CC_FOR_BUILD=${buildPackages.stdenv.cc}/bin/$CC_FOR_BUILD
+      export CPP_FOR_BUILD=${buildPackages.stdenv.cc}/bin/$CPP_FOR_BUILD
+      export CXX_FOR_BUILD=${buildPackages.stdenv.cc}/bin/$CXX_FOR_BUILD
+      export LD_FOR_BUILD=${buildPackages.stdenv.cc.bintools}/bin/$LD_FOR_BUILD
+
+      export AS=$AS_FOR_BUILD
+      export CC=$CC_FOR_BUILD
+      export CPP=$CPP_FOR_BUILD
+      export CXX=$CXX_FOR_BUILD
+      export LD=$LD_FOR_BUILD
+
+      export AS_FOR_TARGET=${stdenvNoLibs.cc}/bin/$AS
+      export CC_FOR_TARGET=${stdenvNoLibs.cc}/bin/$CC
+      export CPP_FOR_TARGET=${stdenvNoLibs.cc}/bin/$CPP
+      export LD_FOR_TARGET=${stdenvNoLibs.cc.bintools}/bin/$LD
+
+      export NIX_BUILD_CFLAGS_COMPILE+=' -DGENERATOR_FILE=1'
+
+      "$sourceRoot/../gcc/configure" $gccConfigureFlags
+
+      sed -e 's,libgcc.mvars:.*$,libgcc.mvars:,' -i Makefile
+
+      make \
+        config.h \
+        libgcc.mvars \
+        tconfig.h \
+        tm.h \
+        options.h \
+        insn-constants.h \
+        insn-modes.h \
+        gcov-iov.h
+    )
+    mkdir -p "$buildRoot/gcc/include"
+  ''
+  # Preparing to configure + build libgcc itself
+  + ''
+    mkdir -p "$buildRoot/gcc/${hostPlatform.config}/libgcc"
+    cd "$buildRoot/gcc/${hostPlatform.config}/libgcc"
+    configureScript=$sourceRoot/configure
+    chmod +x "$configureScript"
+
+    export AS_FOR_BUILD=${buildPackages.stdenv.cc}/bin/$AS_FOR_BUILD
+    export CC_FOR_BUILD=${buildPackages.stdenv.cc}/bin/$CC_FOR_BUILD
+    export CPP_FOR_BUILD=${buildPackages.stdenv.cc}/bin/$CPP_FOR_BUILD
+    export CXX_FOR_BUILD=${buildPackages.stdenv.cc}/bin/$CXX_FOR_BUILD
+    export LD_FOR_BUILD=${buildPackages.stdenv.cc.bintools}/bin/$LD_FOR_BUILD
+
+    export AS=${stdenvNoLibs.cc}/bin/$AS
+    export CC=${stdenvNoLibs.cc}/bin/$CC
+    export CPP=${stdenvNoLibs.cc}/bin/$CPP
+    export CXX=${stdenvNoLibs.cc}/bin/$CXX
+    export LD=${stdenvNoLibs.cc.bintools}/bin/$LD
+
+    export AS_FOR_TARGET=${stdenvNoLibs.cc}/bin/$AS_FOR_TARGET
+    export CC_FOR_TARGET=${stdenvNoLibs.cc}/bin/$CC_FOR_TARGET
+    export CPP_FOR_TARGET=${stdenvNoLibs.cc}/bin/$CPP_FOR_TARGET
+    export LD_FOR_TARGET=${stdenvNoLibs.cc.bintools}/bin/$LD_FOR_TARGET
+  '';
+
+  gccConfigureFlags = [
+    "--build=${buildPlatform.config}"
+    "--host=${buildPlatform.config}"
+    "--target=${hostPlatform.config}"
+
+    "--disable-bootstrap"
+    "--disable-multilib" "--with-multilib-list="
+    "--enable-languages=c"
+
+    "--disable-fixincludes"
+    "--disable-intl"
+    "--disable-lto"
+    "--disable-libatomic"
+    "--disable-libbacktrace"
+    "--disable-libcpp"
+    "--disable-libssp"
+    "--disable-libquadmath"
+    "--disable-libgomp"
+    "--disable-libvtv"
+    "--disable-vtable-verify"
+
+    "--with-system-zlib"
+  ] ++ stdenvNoLibs.lib.optional (hostPlatform.libc == "glibc")
+       "--with-glibc-version=${glibc.version}";
+
+  configurePlatforms = [ "build" "host" ];
+  configureFlags = [
+    "--disable-dependency-tracking"
+    # $CC cannot link binaries, let alone run then
+    "cross_compiling=true"
+    # Do not have dynamic linker without libc
+    "--enable-static"
+    "--disable-shared"
+  ];
+
+  makeFlags = [ "MULTIBUILDTOP:=../" ];
+
+  postInstall = ''
+    moveToOutput "lib/gcc/${hostPlatform.config}/${version}/include" "$dev"
+    mkdir -p "$out/lib" "$dev/include"
+    ln -s "$out/lib/gcc/${hostPlatform.config}/${version}"/* "$out/lib"
+    ln -s "$dev/lib/gcc/${hostPlatform.config}/${version}/include"/* "$dev/include/"
+  '';
+}

pkgs/top-level/all-packages.nix

@@ -22,6 +22,21 @@ with pkgs;
 
   stdenvNoCC = stdenv.override { cc = null; };
 
+  stdenvNoLibs = let
+    bintools = stdenv.cc.bintools.override {
+      libc = null;
+      noLibc = true;
+    };
+  in stdenv.override {
+    cc = stdenv.cc.override {
+      libc = null;
+      noLibc = true;
+      extraPackages = [];
+      inherit bintools;
+    };
+    allowedRequisites = stdenv.allowedRequisites ++ [ bintools ];
+  };
+
   # For convenience, allow callers to get the path to Nixpkgs.
   path = ../..;
 
@@ -8005,6 +8020,8 @@ with pkgs;
 
   librarian-puppet-go = callPackage ../development/tools/librarian-puppet-go { };
 
+  libgcc = callPackage ../development/libraries/gcc/libgcc { };
+
   libstdcxx5 = callPackage ../development/libraries/gcc/libstdc++/5.nix { };
 
   libsigrok = callPackage ../development/tools/libsigrok { };