# Copyright 2013-2020 Lawrence Livermore National Security, LLC and other
# Spack Project Developers. See the top-level COPYRIGHT file for details.
#
# SPDX-License-Identifier: (Apache-2.0 OR MIT)

from spack import *


class Xpmem(AutotoolsPackage):
    """XPMEM is a Linux kernel module that enables a process to map the memory
    of another process into its virtual address space."""

    # The README file of the repository says that the development was
    # transferred to a new repository on GitLab: http://gitlab.com/hjelmn/xpmem
    # However, it looks like that the repository on GitHub has a more recent
    # version of the codebase.
    homepage = "https://github.com/hjelmn/xpmem"
    url = "https://github.com/hjelmn/xpmem/archive/v2.6.3.tar.gz"
    git = "https://github.com/hjelmn/xpmem.git"

    maintainers = ['skosukhin']

    version('master', branch='master')

    # Versions starting 2.6.4 are neither tagged nor released in the repo
    # (the choice of commits is based on the commit history of
    # 'kernel/xpmem_private.h'):
    version('2.6.5', commit='4efeed9cbaabe971f3766d67cb108e2c3316d4b8')
    version('2.6.4', commit='522054850e4d1479d69f50f7190d1548bf9749fd')

    # Released versions:
    version('2.6.3', sha256='ee239a32269f33234cdbdb94db29c12287862934c0784328d34aff82a9fa8b54')
    version('2.6.2', sha256='2c1a93b4cb20ed73c2093435a7afec513e0e797aa1e49d4d964cc6bdae89d65b')

    variant('kernel-module', default=True,
            description='Enable building the kernel module')

    depends_on('autoconf', type='build')
    depends_on('automake', type='build')
    depends_on('libtool',  type='build')
    depends_on('m4',       type='build')

    # It will become possible to disable the kernel module only starting 2.6.6:
    # https://github.com/hjelmn/xpmem/pull/24
    conflicts('~kernel-module', when='@:2.6.5')

    # Ideally, we should list all non-Linux-based platforms here:
    conflicts('+kernel-module', when='platform=darwin')

    # All compilers except for gcc are in conflict with +kernel-module:
    for __compiler in spack.compilers.supported_compilers():
        if __compiler != 'gcc':
            conflicts('+kernel-module',
                      when='%{0}'.format(__compiler),
                      msg='Linux kernel module must be compiled with gcc')

    def autoreconf(self, spec, prefix):
        Executable('./autogen.sh')()

    @run_before('build')
    def override_kernel_compiler(self):
        # Override the compiler for kernel module source files. We need
        # this additional argument for all installation phases.
        if '+kernel-module' in self.spec:
            make.add_default_arg('CC={0}'.format(spack_cc))

    def configure_args(self):
        args = []

        if '~kernel-module' in self.spec:
            # The kernel module is enabled by default. An attempt of explicit
            # enabling with '--enable-kernel-module' disables the module.
            args.extend('--disable-kernel-module')

        if self.spec.satisfies('@:2.6.5'):
            fmt = self.spec.format
            # The following arguments will not be needed starting 2.6.6:
            # https://github.com/hjelmn/xpmem/pull/18
            args.extend([
                fmt('--with-default-prefix={prefix}'),
                fmt('--with-module={prefix.share}/Modules/{name}/{version}')])

        return args

    @when('@:2.6.5')
    def install(self, spec, prefix):
        with working_dir(self.build_directory):
            # Override the hardcoded prefix for 'cray-xpmem.conf'
            make('ldsoconfdir={0}'.format(
                self.spec.prefix.etc.join('ld.so.conf.d')),
                *self.install_targets)