Python rez package build script

package.py

name = "python"

version = "3.7.4"

authors = ["Guido van Rossum"]

description = \
    """
    The Python programming language.
    """

requires = [
    #'libexpat-2.2.9+',
    #'zlib-1.2.3+',
]
private_build_requires = [
    gcc,  # or `llvm` 
    #'xz-5.2.4+',
]


@early()
def pyver():
    import sys

    return {
        '2.7': '2.7',
        '3.6': '3.6m',
        '3.7': '3.7m',
        '3.8': '3.8',
        '3.9': '3.9'
    }['.'.join(str(this.version).split('.')[0:2])]


@early()
def variants():
    from rez.package_py_utils import expand_requires
    requires = ["platform-**", "arch-**", "os-**"]
    return [expand_requires(*requires)]


@early()
def tools():
    # conditionally enumerate python 2 / 3 tools
    maj, mnr = this.version.split('.')[0:2]
    pyver = '.'.join([maj, mnr])
    all_vers = ['python{0}', 'python{0}-config', 'pydoc{0}', 'pip{0}']
    py2_only = ['smtpd.py']
    py3_only = ['pyenv', 'idle3']
    tools = py2_only if int(maj) < 3 else py3_only + ['idle']
    variants = ['', maj, pyver]
    for tool in all_vers:
        for variant in variants:
            tools.append(tool.format(variant))
    return tools + ['2to3', 'idle']


@early()
def uuid():
    import uuid
    return str(uuid.uuid5(uuid.NAMESPACE_DNS, name))


def pre_build_commands():
    pyver = str(this.version)
    url = "http://www.python.org/ftp/python/{pyver}/Python-{pyver}.tgz" % (pyver, pyver)
    env.CFLAGS = ("-O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions "
                  "-fstack-protector-strong --param=ssp-buffer-size=4 -grecord-gcc-switches "
                  "-m64 -mtune=generic -D_GNU_SOURCE -fPIC -fwrapv $CFLAGS")
    env.LDFLAGS = "-Wl,-z,relro,-rpath=${build.install_path}/lib $LDFLAGS"

    env.REZ_BUILD_CONFIGURE_OPTIONS = " ".join([
        "--prefix={build.install_path}",
        "--enable-ipv6",
        "--enable-shared",
        "--enable-unicode=ucs4",
        "--with-dbmliborder=gdbm:ndbm:bdb",  # build DBM module against GDBM instead of Berkley DB
        "--with-system-expat",  # use system libexpat
        "--with-system-ffi",  # use system libffi
        "--with-ensurepip=yes",  # install pip 
        "--with-computed-gotos=yes",
        "--enable-optimizations",
        "--enable-loadable-sqlite-extensions",
        #"--with-dtrace",
        "--with-valgrind",
        #"--build=x86-64-redhat-linux-gnu "
        #"--host=x86_64-redhat-linux-gnu "
        #"--without-ensurepip "
    ])
    py_maj = int(this.version[0])

    def link_cmd(exe):
        return 'ln -sfv {exe}{this.version.major} {build.install_path}/bin/{exe}' if py_maj > 2 else ''

    env.REZ_BUILD_DOWNLOAD_CMD = 'wget %s' % url
    env.REZ_BUILD_LINK_CMD_0 = link_cmd('python')
    env.REZ_BUILD_LINK_CMD_1 = link_cmd('idle')
    env.REZ_BUILD_LINK_CMD_2 = link_cmd('pydoc')
    env.REZ_BUILD_LINK_CMD_3 = link_cmd('pip')
    env.REZ_BUILD_LINK_CMD_4 = 'ln -sfv python{this.version.major}-config {build.install_path}/bin/python-config'
    env.REZ_BUILD_LINK_CMD_5 = 'ln -sfv {build.install_path}/bin/python{this.version.major} {build.install_path}/bin/rez-python'


build_command = """
$REZ_BUILD_DOWNLOAD_CMD
tar -xvf Python*.tgz --strip 1
./configure $REZ_BUILD_CONFIGURE_OPTIONS
make install -j$REZ_BUILD_THREAD_COUNT VERBOSE=1

$REZ_BUILD_LINK_CMD_0
$REZ_BUILD_LINK_CMD_1
$REZ_BUILD_LINK_CMD_2
$REZ_BUILD_LINK_CMD_3
$REZ_BUILD_LINK_CMD_4
$REZ_BUILD_LINK_CMD_5

$REZ_BUILD_INSTALL_PATH/bin/python -m pip install --upgrade pip
$REZ_BUILD_INSTALL_PATH/bin/python -m pip install --upgrade setuptools
"""


def pre_commands():
    env.PYTHONHOME.unset()


def commands():
    env.PATH.prepend("{root}/bin")
    extension = {'osx': 'dylib', 'linux': 'so.1.0', 'win': 'dll'}[system.platform]

    if building:
        maj_min = this.pyver.strip('m')
        maj = this.version.major
        env.PYTHON_LIBRARY_VERSION = this.pyver
        env.PYTHON_VERSION = maj_min
        env.PYTHON_LDVERSION = this.pyver
        # CMake hints
        env.Python_ROOT = '{root}'
        env.Python_FIND_STRATEGY = 'LOCATION'  # prefer this python over python with higher ver number
        env.Python_FIND_REGISTRY = 'NEVER'  # prefer rez python over windows registry python
        env.Python_FIND_FRAMEWORK = 'NEVER'  # prefer rez python over osx framework python
        env.Python_FIND_VIRTUALENV = 'STANDARD'  # prefer rez python over virtualenv pythobn
        env.Python_FIND_ABI = '"OFF" "ON" "ANY"'  # debug, malloc, unicode

        env.PYTHON_CMAKE_ARTIFACTS = ' '.join([
            '-DPython_INCLUDE_DIR={root}/include/python{this.pyver}',
            '-DPython_EXECUTABLE={root}/bin/python{this.pyver}',
            '-DPython_LIBRARY={root}/lib/libpython{this.pyver}.{extension}',
            '-DPython{maj}_INCLUDE_DIR={root}/include/python{this.pyver}',
            '-DPython{maj}_EXECUTABLE={root}/bin/python{this.pyver}',
            '-DPython{maj}_LIBRARY={root}/lib/libpython{this.pyver}.{extension}',
            '-DPython{maj}_NumPy_INCLUDE_DIR=$REZ_NUMPY_ROOT/python/numpy/core/include' if 'numpy' in resolve else '',
        ])

        env.PKG_CONFIG_PATH.prepend('{root}/include/pkgconfig')
        env.LDFLAGS = '-L{root}/lib -Wl,-z,relro,-rpath={root}/lib $LDFLAGS'
        for c in ['CFLAGS', 'CPPFLAGS', 'CXXFLAGS']:
            setenv(c, '-I{root}/include $%s' % c)