source $stdenv/setup


export NIX_FIXINC_DUMMY=$NIX_BUILD_TOP/dummy
mkdir $NIX_FIXINC_DUMMY


# libstdc++ needs this; otherwise it will use /lib/cpp, which is a Bad
# Thing.
export CPP="gcc -E"
export CXXCPP="gcc -E"


if test "$noSysDirs" = "1"; then

    if test "$noSysDirs" = "1"; then
        # Figure out what extra flags to pass to the gcc compilers
        # being generated to make sure that they use our glibc.
        if test -e $NIX_GCC/nix-support/orig-glibc; then
            glibc=$(cat $NIX_GCC/nix-support/orig-glibc)

            # Ugh.  Copied from gcc-wrapper/builder.sh.  We can't just
            # source in $NIX_GCC/nix-support/add-flags, since that
            # would cause *this* GCC to be linked against the
            # *previous* GCC.  Need some more modularity there.
            extraCFlags="-B$glibc/lib -isystem $glibc/include"
            extraLDFlags="-B$glibc/lib -L$glibc/lib -Wl,-s \
              -Wl,-dynamic-linker,$glibc/lib/ld-linux.so.2"

            # Oh, what a hack.  I should be shot for this.
            # In stage 1, we should link against the previous GCC, but
            # not afterwards.  Otherwise we retain a dependency.
            # However, ld-wrapper, which adds the linker flags for the
            # previous GCC, is also used in stage 2/3.  We can prevent
            # it from adding them by NIX_GLIBC_FLAGS_SET, but then
            # gcc-wrapper will also not add them, thereby causing
            # stage 1 to fail.  So we use a trick to only set the
            # flags in gcc-wrapper.
            hook=$(pwd)/ld-wrapper-hook
            echo "NIX_GLIBC_FLAGS_SET=1" > $hook
            export NIX_LD_WRAPPER_START_HOOK=$hook

            # Use *real* header files, otherwise a limits.h is
            # generated that does not include Glibc's limits.h
            # (notably missing SSIZE_MAX, which breaks the build).
            export NIX_FIXINC_DUMMY=$glibc/include
        fi

        export NIX_EXTRA_CFLAGS=$extraCFlags
        export NIX_EXTRA_LDFLAGS=$extraLDFlags
        export CFLAGS=$extraCFlags
        export CXXFLAGS=$extraCFlags
        export LDFLAGS=$extraLDFlags
    fi

else
    patches=""
fi


preConfigure=preConfigure
preConfigure() {
    
    # Determine the frontends to build.
    langs="c"
    if test -n "$langCC"; then
        langs="$langs,c++"
    fi
    if test -n "$langF77"; then
        langs="$langs,f77"
    fi

    # Perform the build in a different directory.
    mkdir ../build
    cd ../build

    configureScript=../$sourceRoot/configure
    configureFlags="--enable-languages=$langs"
}


postInstall=postInstall
postInstall() {
    # Remove precompiled headers for now.  They are very big and
    # probably not very useful yet.
    find $out/include -name "*.gch" -exec rm -rf {} \; -prune

    # Remove `fixincl' to prevent a retained dependency on the
    # previous gcc.
    rm -rf $out/libexec/gcc/*/*/install-tools
}


if test -z "$profiledCompiler"; then
    makeFlags="bootstrap"
else    
    makeFlags="profiledbootstrap"
fi

genericBuild