system_info.py

#!/usr/bin/env python3
"""
This file defines a set of system_info classes for getting
information about various resources (libraries, library directories,
include directories, etc.) in the system. Usage:
    info_dict = get_info(<name>)
  where <name> is a string 'atlas','x11','fftw','lapack','blas',
  'lapack_src', 'blas_src', etc. For a complete list of allowed names,
  see the definition of get_info() function below.

  Returned info_dict is a dictionary which is compatible with
  distutils.setup keyword arguments. If info_dict == {}, then the
  asked resource is not available (system_info could not find it).

  Several *_info classes specify an environment variable to specify
  the locations of software. When setting the corresponding environment
  variable to 'None' then the software will be ignored, even when it
  is available in system.

Global parameters:
  system_info.search_static_first - search static libraries (.a)
             in precedence to shared ones (.so, .sl) if enabled.
  system_info.verbosity - output the results to stdout if enabled.

The file 'site.cfg' is looked for in

1) Directory of main setup.py file being run.
2) Home directory of user running the setup.py file as ~/.numpy-site.cfg
3) System wide directory (location of this file...)

The first one found is used to get system configuration options The
format is that used by ConfigParser (i.e., Windows .INI style). The
section ALL is not intended for general use.

Appropriate defaults are used if nothing is specified.

The order of finding the locations of resources is the following:
 1. environment variable
 2. section in site.cfg
 3. DEFAULT section in site.cfg
 4. System default search paths (see ``default_*`` variables below).
Only the first complete match is returned.

Currently, the following classes are available, along with their section names:

    Numeric_info:Numeric
    _numpy_info:Numeric
    _pkg_config_info:None
    accelerate_info:accelerate
    agg2_info:agg2
    amd_info:amd
    atlas_3_10_blas_info:atlas
    atlas_3_10_blas_threads_info:atlas
    atlas_3_10_info:atlas
    atlas_3_10_threads_info:atlas
    atlas_blas_info:atlas
    atlas_blas_threads_info:atlas
    atlas_info:atlas
    atlas_threads_info:atlas
    blas64__opt_info:ALL               # usage recommended (general ILP64 BLAS, 64_ symbol suffix)
    blas_ilp64_opt_info:ALL            # usage recommended (general ILP64 BLAS)
    blas_ilp64_plain_opt_info:ALL      # usage recommended (general ILP64 BLAS, no symbol suffix)
    blas_info:blas
    blas_mkl_info:mkl
    blas_ssl2_info:ssl2
    blas_opt_info:ALL                  # usage recommended
    blas_src_info:blas_src
    blis_info:blis
    boost_python_info:boost_python
    dfftw_info:fftw
    dfftw_threads_info:fftw
    djbfft_info:djbfft
    f2py_info:ALL
    fft_opt_info:ALL
    fftw2_info:fftw
    fftw3_info:fftw3
    fftw_info:fftw
    fftw_threads_info:fftw
    flame_info:flame
    freetype2_info:freetype2
    gdk_2_info:gdk_2
    gdk_info:gdk
    gdk_pixbuf_2_info:gdk_pixbuf_2
    gdk_pixbuf_xlib_2_info:gdk_pixbuf_xlib_2
    gdk_x11_2_info:gdk_x11_2
    gtkp_2_info:gtkp_2
    gtkp_x11_2_info:gtkp_x11_2
    lapack64__opt_info:ALL             # usage recommended (general ILP64 LAPACK, 64_ symbol suffix)
    lapack_atlas_3_10_info:atlas
    lapack_atlas_3_10_threads_info:atlas
    lapack_atlas_info:atlas
    lapack_atlas_threads_info:atlas
    lapack_ilp64_opt_info:ALL          # usage recommended (general ILP64 LAPACK)
    lapack_ilp64_plain_opt_info:ALL    # usage recommended (general ILP64 LAPACK, no symbol suffix)
    lapack_info:lapack
    lapack_mkl_info:mkl
    lapack_ssl2_info:ssl2
    lapack_opt_info:ALL                # usage recommended
    lapack_src_info:lapack_src
    mkl_info:mkl
    ssl2_info:ssl2
    numarray_info:numarray
    numerix_info:numerix
    numpy_info:numpy
    openblas64__info:openblas64_
    openblas64__lapack_info:openblas64_
    openblas_clapack_info:openblas
    openblas_ilp64_info:openblas_ilp64
    openblas_ilp64_lapack_info:openblas_ilp64
    openblas_info:openblas
    openblas_lapack_info:openblas
    sfftw_info:fftw
    sfftw_threads_info:fftw
    system_info:ALL
    umfpack_info:umfpack
    wx_info:wx
    x11_info:x11
    xft_info:xft

Note that blas_opt_info and lapack_opt_info honor the NPY_BLAS_ORDER
and NPY_LAPACK_ORDER environment variables to determine the order in which
specific BLAS and LAPACK libraries are searched for.

This search (or autodetection) can be bypassed by defining the environment
variables NPY_BLAS_LIBS and NPY_LAPACK_LIBS, which should then contain the
exact linker flags to use (language will be set to F77). Building against
Netlib BLAS/LAPACK or stub files, in order to be able to switch BLAS and LAPACK
implementations at runtime. If using this to build NumPy itself, it is
recommended to also define NPY_CBLAS_LIBS (assuming your BLAS library has a
CBLAS interface) to enable CBLAS usage for matrix multiplication (unoptimized
otherwise).

Example:
----------
[DEFAULT]
# default section
library_dirs = /usr/lib:/usr/local/lib:/opt/lib
include_dirs = /usr/include:/usr/local/include:/opt/include
src_dirs = /usr/local/src:/opt/src
# search static libraries (.a) in preference to shared ones (.so)
search_static_first = 0

[fftw]
libraries = rfftw, fftw

[atlas]
library_dirs = /usr/lib/3dnow:/usr/lib/3dnow/atlas
# for overriding the names of the atlas libraries
libraries = lapack, f77blas, cblas, atlas

[x11]
library_dirs = /usr/X11R6/lib
include_dirs = /usr/X11R6/include
----------

Note that the ``libraries`` key is the default setting for libraries.

Authors:
  Pearu Peterson <pearu@cens.ioc.ee>, February 2002
  David M. Cooke <cookedm@physics.mcmaster.ca>, April 2002

Copyright 2002 Pearu Peterson all rights reserved,
Pearu Peterson <pearu@cens.ioc.ee>
Permission to use, modify, and distribute this software is given under the
terms of the NumPy (BSD style) license.  See LICENSE.txt that came with
this distribution for specifics.

NO WARRANTY IS EXPRESSED OR IMPLIED.  USE AT YOUR OWN RISK.

"""
import sys
import os
import re
import copy
import warnings
import subprocess
import textwrap

from glob import glob
from functools import reduce
from configparser import NoOptionError
from configparser import RawConfigParser as ConfigParser
# It seems that some people are importing ConfigParser from here so is
# good to keep its class name. Use of RawConfigParser is needed in
# order to be able to load path names with percent in them, like
# `feature%2Fcool` which is common on git flow branch names.

from distutils.errors import DistutilsError
from distutils.dist import Distribution
import sysconfig
from numpy.distutils import log
from distutils.util import get_platform

from numpy.distutils.exec_command import (
    find_executable, filepath_from_subprocess_output,
    )
from numpy.distutils.misc_util import (is_sequence, is_string,
                                       get_shared_lib_extension)
from numpy.distutils.command.config import config as cmd_config
from numpy.distutils import customized_ccompiler as _customized_ccompiler
from numpy.distutils import _shell_utils
import distutils.ccompiler
import tempfile
import shutil

__all__ = ['system_info']

# Determine number of bits
import platform
_bits = {'32bit': 32, '64bit': 64}
platform_bits = _bits[platform.architecture()[0]]


global_compiler = None

def customized_ccompiler():
    global global_compiler
    if not global_compiler:
        global_compiler = _customized_ccompiler()
    return global_compiler


def _c_string_literal(s):
    """
    Convert a python string into a literal suitable for inclusion into C code
    """
    # only these three characters are forbidden in C strings
    s = s.replace('\\', r'\\')
    s = s.replace('"',  r'\"')
    s = s.replace('\n', r'\n')
    return '"{}"'.format(s)


def libpaths(paths, bits):
    """Return a list of library paths valid on 32 or 64 bit systems.

    Inputs:
      paths : sequence
        A sequence of strings (typically paths)
      bits : int
        An integer, the only valid values are 32 or 64.  A ValueError exception
      is raised otherwise.

    Examples:

    Consider a list of directories
    >>> paths = ['/usr/X11R6/lib','/usr/X11/lib','/usr/lib']

    For a 32-bit platform, this is already valid:
    >>> np.distutils.system_info.libpaths(paths,32)
    ['/usr/X11R6/lib', '/usr/X11/lib', '/usr/lib']

    On 64 bits, we prepend the '64' postfix
    >>> np.distutils.system_info.libpaths(paths,64)
    ['/usr/X11R6/lib64', '/usr/X11R6/lib', '/usr/X11/lib64', '/usr/X11/lib',
    '/usr/lib64', '/usr/lib']
    """
    if bits not in (32, 64):
        raise ValueError("Invalid bit size in libpaths: 32 or 64 only")

    # Handle 32bit case
    if bits == 32:
        return paths

    # Handle 64bit case
    out = []
    for p in paths:
        out.extend([p + '64', p])

    return out


if sys.platform == 'win32':
    default_lib_dirs = ['C:\\',
                        os.path.join(sysconfig.get_config_var('exec_prefix'),
                                     'libs')]
    default_runtime_dirs = []
    default_include_dirs = []
    default_src_dirs = ['.']
    default_x11_lib_dirs = []
    default_x11_include_dirs = []
    _include_dirs = [
        'include',
        'include/suitesparse',
    ]
    _lib_dirs = [
        'lib',
    ]

    _include_dirs = [d.replace('/', os.sep) for d in _include_dirs]
    _lib_dirs = [d.replace('/', os.sep) for d in _lib_dirs]
    def add_system_root(library_root):
        """Add a package manager root to the include directories"""
        global default_lib_dirs
        global default_include_dirs

        library_root = os.path.normpath(library_root)

        default_lib_dirs.extend(
            os.path.join(library_root, d) for d in _lib_dirs)
        default_include_dirs.extend(
            os.path.join(library_root, d) for d in _include_dirs)

    # VCpkg is the de-facto package manager on windows for C/C++
    # libraries. If it is on the PATH, then we append its paths here.
    vcpkg = shutil.which('vcpkg')
    if vcpkg:
        vcpkg_dir = os.path.dirname(vcpkg)
        if platform.architecture()[0] == '32bit':
            specifier = 'x86'
        else:
            specifier = 'x64'

        vcpkg_installed = os.path.join(vcpkg_dir, 'installed')
        for vcpkg_root in [
            os.path.join(vcpkg_installed, specifier + '-windows'),
            os.path.join(vcpkg_installed, specifier + '-windows-static'),
        ]:
            add_system_root(vcpkg_root)

    # Conda is another popular package manager that provides libraries
    conda = shutil.which('conda')
    if conda:
        conda_dir = os.path.dirname(conda)
        add_system_root(os.path.join(conda_dir, '..', 'Library'))
        add_system_root(os.path.join(conda_dir, 'Library'))

else:
    default_lib_dirs = libpaths(['/usr/local/lib', '/opt/lib', '/usr/lib',
                                 '/opt/local/lib', '/sw/lib'], platform_bits)
    default_runtime_dirs = []
    default_include_dirs = ['/usr/local/include',
                            '/opt/include',
                            # path of umfpack under macports
                            '/opt/local/include/ufsparse',
                            '/opt/local/include', '/sw/include',
                            '/usr/include/suitesparse']
    default_src_dirs = ['.', '/usr/local/src', '/opt/src', '/sw/src']

    default_x11_lib_dirs = libpaths(['/usr/X11R6/lib', '/usr/X11/lib',
                                     '/usr/lib'], platform_bits)
    default_x11_include_dirs = ['/usr/X11R6/include', '/usr/X11/include']

    if os.path.exists('/usr/lib/X11'):
        globbed_x11_dir = glob('/usr/lib/*/libX11.so')
        if globbed_x11_dir:
            x11_so_dir = os.path.split(globbed_x11_dir[0])[0]
            default_x11_lib_dirs.extend([x11_so_dir, '/usr/lib/X11'])
            default_x11_include_dirs.extend(['/usr/lib/X11/include',
                                             '/usr/include/X11'])

    with open(os.devnull, 'w') as tmp:
        try:
            p = subprocess.Popen(["gcc", "-print-multiarch"], stdout=subprocess.PIPE,
                         stderr=tmp)
        except (OSError, DistutilsError):
            # OSError if gcc is not installed, or SandboxViolation (DistutilsError
            # subclass) if an old setuptools bug is triggered (see gh-3160).
            pass
        else:
            triplet = str(p.communicate()[0].decode().strip())
            if p.returncode == 0:
                # gcc supports the "-print-multiarch" option
                default_x11_lib_dirs += [os.path.join("/usr/lib/", triplet)]
                default_lib_dirs += [os.path.join("/usr/lib/", triplet)]


if os.path.join(sys.prefix, 'lib') not in default_lib_dirs:
    default_lib_dirs.insert(0, os.path.join(sys.prefix, 'lib'))
    default_include_dirs.append(os.path.join(sys.prefix, 'include'))
    default_src_dirs.append(os.path.join(sys.prefix, 'src'))

default_lib_dirs = [_m for _m in default_lib_dirs if os.path.isdir(_m)]
default_runtime_dirs = [_m for _m in default_runtime_dirs if os.path.isdir(_m)]
default_include_dirs = [_m for _m in default_include_dirs if os.path.isdir(_m)]
default_src_dirs = [_m for _m in default_src_dirs if os.path.isdir(_m)]

so_ext = get_shared_lib_extension()


def get_standard_file(fname):
    """Returns a list of files named 'fname' from
    1) System-wide directory (directory-location of this module)
    2) Users HOME directory (os.environ['HOME'])
    3) Local directory
    """
    # System-wide file
    filenames = []
    try:
        f = __file__
    except NameError:
        f = sys.argv[0]
    sysfile = os.path.join(os.path.split(os.path.abspath(f))[0],
                           fname)
    if os.path.isfile(sysfile):
        filenames.append(sysfile)

    # Home directory
    # And look for the user config file
    try:
        f = os.path.expanduser('~')
    except KeyError:
        pass
    else:
        user_file = os.path.join(f, fname)
        if os.path.isfile(user_file):
            filenames.append(user_file)

    # Local file
    if os.path.isfile(fname):
        filenames.append(os.path.abspath(fname))

    return filenames


def _parse_env_order(base_order, env):
    """ Parse an environment variable `env` by splitting with "," and only returning elements from `base_order`

    This method will sequence the environment variable and check for their
    individual elements in `base_order`.

    The items in the environment variable may be negated via '^item' or '!itema,itemb'.
    It must start with ^/! to negate all options.

    Raises
    ------
    ValueError: for mixed negated and non-negated orders or multiple negated orders

    Parameters
    ----------
    base_order : list of str
       the base list of orders
    env : str
       the environment variable to be parsed, if none is found, `base_order` is returned

    Returns
    -------
    allow_order : list of str
        allowed orders in lower-case
    unknown_order : list of str
        for values not overlapping with `base_order`
    """
    order_str = os.environ.get(env, None)

    # ensure all base-orders are lower-case (for easier comparison)
    base_order = [order.lower() for order in base_order]
    if order_str is None:
        return base_order, []

    neg = order_str.startswith('^') or order_str.startswith('!')
    # Check format
    order_str_l = list(order_str)
    sum_neg = order_str_l.count('^') + order_str_l.count('!')
    if neg:
        if sum_neg > 1:
            raise ValueError(f"Environment variable '{env}' may only contain a single (prefixed) negation: {order_str}")
        # remove prefix
        order_str = order_str[1:]
    elif sum_neg > 0:
        raise ValueError(f"Environment variable '{env}' may not mix negated an non-negated items: {order_str}")

    # Split and lower case
    orders = order_str.lower().split(',')

    # to inform callee about non-overlapping elements
    unknown_order = []

    # if negated, we have to remove from the order
    if neg:
        allow_order = base_order.copy()

        for order in orders:
            if not order:
                continue

            if order not in base_order:
                unknown_order.append(order)
                continue

            if order in allow_order:
                allow_order.remove(order)

    else:
        allow_order = []

        for order in orders:
            if not order:
                continue

            if order not in base_order:
                unknown_order.append(order)
                continue

            if order not in allow_order:
                allow_order.append(order)

    return allow_order, unknown_order


def get_info(name, notfound_action=0):
    """
    notfound_action:
      0 - do nothing
      1 - display warning message
      2 - raise error
    """
    cl = {'armpl': armpl_info,
          'blas_armpl': blas_armpl_info,
          'lapack_armpl': lapack_armpl_info,
          'fftw3_armpl': fftw3_armpl_info,
          'atlas': atlas_info,  # use lapack_opt or blas_opt instead
          'atlas_threads': atlas_threads_info,                # ditto
          'atlas_blas': atlas_blas_info,
          'atlas_blas_threads': atlas_blas_threads_info,
          'lapack_atlas': lapack_atlas_info,  # use lapack_opt instead
          'lapack_atlas_threads': lapack_atlas_threads_info,  # ditto
          'atlas_3_10': atlas_3_10_info,  # use lapack_opt or blas_opt instead
          'atlas_3_10_threads': atlas_3_10_threads_info,                # ditto
          'atlas_3_10_blas': atlas_3_10_blas_info,
          'atlas_3_10_blas_threads': atlas_3_10_blas_threads_info,
          'lapack_atlas_3_10': lapack_atlas_3_10_info,  # use lapack_opt instead
          'lapack_atlas_3_10_threads': lapack_atlas_3_10_threads_info,  # ditto
          'flame': flame_info,          # use lapack_opt instead
          'mkl': mkl_info,
          'ssl2': ssl2_info,
          # openblas which may or may not have embedded lapack
          'openblas': openblas_info,          # use blas_opt instead
          # openblas with embedded lapack
          'openblas_lapack': openblas_lapack_info, # use blas_opt instead
          'openblas_clapack': openblas_clapack_info, # use blas_opt instead
          'blis': blis_info,                  # use blas_opt instead
          'lapack_mkl': lapack_mkl_info,      # use lapack_opt instead
          'blas_mkl': blas_mkl_info,          # use blas_opt instead
          'lapack_ssl2': lapack_ssl2_info,      
          'blas_ssl2': blas_ssl2_info,          
          'accelerate': accelerate_info,      # use blas_opt instead
          'openblas64_': openblas64__info,
          'openblas64__lapack': openblas64__lapack_info,
          'openblas_ilp64': openblas_ilp64_info,
          'openblas_ilp64_lapack': openblas_ilp64_lapack_info,
          'x11': x11_info,
          'fft_opt': fft_opt_info,
          'fftw': fftw_info,
          'fftw2': fftw2_info,
          'fftw3': fftw3_info,
          'dfftw': dfftw_info,
          'sfftw': sfftw_info,
          'fftw_threads': fftw_threads_info,
          'dfftw_threads': dfftw_threads_info,
          'sfftw_threads': sfftw_threads_info,
          'djbfft': djbfft_info,
          'blas': blas_info,                  # use blas_opt instead
          'lapack': lapack_info,              # use lapack_opt instead
          'lapack_src': lapack_src_info,
          'blas_src': blas_src_info,
          'numpy': numpy_info,
          'f2py': f2py_info,
          'Numeric': Numeric_info,
          'numeric': Numeric_info,
          'numarray': numarray_info,
          'numerix': numerix_info,
          'lapack_opt': lapack_opt_info,
          'lapack_ilp64_opt': lapack_ilp64_opt_info,
          'lapack_ilp64_plain_opt': lapack_ilp64_plain_opt_info,
          'lapack64__opt': lapack64__opt_info,
          'blas_opt': blas_opt_info,
          'blas_ilp64_opt': blas_ilp64_opt_info,
          'blas_ilp64_plain_opt': blas_ilp64_plain_opt_info,
          'blas64__opt': blas64__opt_info,
          'boost_python': boost_python_info,
          'agg2': agg2_info,
          'wx': wx_info,
          'gdk_pixbuf_xlib_2': gdk_pixbuf_xlib_2_info,
          'gdk-pixbuf-xlib-2.0': gdk_pixbuf_xlib_2_info,
          'gdk_pixbuf_2': gdk_pixbuf_2_info,
          'gdk-pixbuf-2.0': gdk_pixbuf_2_info,
          'gdk': gdk_info,
          'gdk_2': gdk_2_info,
          'gdk-2.0': gdk_2_info,
          'gdk_x11_2': gdk_x11_2_info,
          'gdk-x11-2.0': gdk_x11_2_info,
          'gtkp_x11_2': gtkp_x11_2_info,
          'gtk+-x11-2.0': gtkp_x11_2_info,
          'gtkp_2': gtkp_2_info,
          'gtk+-2.0': gtkp_2_info,
          'xft': xft_info,
          'freetype2': freetype2_info,
          'umfpack': umfpack_info,
          'amd': amd_info,
          }.get(name.lower(), system_info)
    return cl().get_info(notfound_action)


class NotFoundError(DistutilsError):
    """Some third-party program or library is not found."""


class AliasedOptionError(DistutilsError):
    """
    Aliases entries in config files should not be existing.
    In section '{section}' we found multiple appearances of options {options}."""


class AtlasNotFoundError(NotFoundError):
    """
    Atlas (http://github.com/math-atlas/math-atlas) libraries not found.
    Directories to search for the libraries can be specified in the
    numpy/distutils/site.cfg file (section [atlas]) or by setting
    the ATLAS environment variable."""


class FlameNotFoundError(NotFoundError):
    """
    FLAME (http://www.cs.utexas.edu/~flame/web/) libraries not found.
    Directories to search for the libraries can be specified in the
    numpy/distutils/site.cfg file (section [flame])."""


class LapackNotFoundError(NotFoundError):
    """
    Lapack (http://www.netlib.org/lapack/) libraries not found.
    Directories to search for the libraries can be specified in the
    numpy/distutils/site.cfg file (section [lapack]) or by setting
    the LAPACK environment variable."""


class LapackSrcNotFoundError(LapackNotFoundError):
    """
    Lapack (http://www.netlib.org/lapack/) sources not found.
    Directories to search for the sources can be specified in the
    numpy/distutils/site.cfg file (section [lapack_src]) or by setting
    the LAPACK_SRC environment variable."""


class LapackILP64NotFoundError(NotFoundError):
    """
    64-bit Lapack libraries not found.
    Known libraries in numpy/distutils/site.cfg file are:
    openblas64_, openblas_ilp64
    """

class BlasOptNotFoundError(NotFoundError):
    """
    Optimized (vendor) Blas libraries are not found.
    Falls back to netlib Blas library which has worse performance.
    A better performance should be easily gained by switching
    Blas library."""

class BlasNotFoundError(NotFoundError):
    """
    Blas (http://www.netlib.org/blas/) libraries not found.
    Directories to search for the libraries can be specified in the
    numpy/distutils/site.cfg file (section [blas]) or by setting
    the BLAS environment variable."""

class BlasILP64NotFoundError(NotFoundError):
    """
    64-bit Blas libraries not found.
    Known libraries in numpy/distutils/site.cfg file are:
    openblas64_, openblas_ilp64
    """

class BlasSrcNotFoundError(BlasNotFoundError):
    """
    Blas (http://www.netlib.org/blas/) sources not found.
    Directories to search for the sources can be specified in the
    numpy/distutils/site.cfg file (section [blas_src]) or by setting
    the BLAS_SRC environment variable."""


class FFTWNotFoundError(NotFoundError):
    """
    FFTW (http://www.fftw.org/) libraries not found.
    Directories to search for the libraries can be specified in the
    numpy/distutils/site.cfg file (section [fftw]) or by setting
    the FFTW environment variable."""


class DJBFFTNotFoundError(NotFoundError):
    """
    DJBFFT (https://cr.yp.to/djbfft.html) libraries not found.
    Directories to search for the libraries can be specified in the
    numpy/distutils/site.cfg file (section [djbfft]) or by setting
    the DJBFFT environment variable."""


class NumericNotFoundError(NotFoundError):
    """
    Numeric (https://www.numpy.org/) module not found.
    Get it from above location, install it, and retry setup.py."""


class X11NotFoundError(NotFoundError):
    """X11 libraries not found."""


class UmfpackNotFoundError(NotFoundError):
    """
    UMFPACK sparse solver (https://www.cise.ufl.edu/research/sparse/umfpack/)
    not found. Directories to search for the libraries can be specified in the
    numpy/distutils/site.cfg file (section [umfpack]) or by setting
    the UMFPACK environment variable."""


class system_info:

    """ get_info() is the only public method. Don't use others.
    """
    dir_env_var = None
    # XXX: search_static_first is disabled by default, may disappear in
    # future unless it is proved to be useful.
    search_static_first = 0
    # The base-class section name is a random word "ALL" and is not really
    # intended for general use. It cannot be None nor can it be DEFAULT as
    # these break the ConfigParser. See gh-15338
    section = 'ALL'
    saved_results = {}

    notfounderror = NotFoundError

    def __init__(self,
                  default_lib_dirs=default_lib_dirs,
                  default_include_dirs=default_include_dirs,
                  ):
        self.__class__.info = {}
        self.local_prefixes = []
        defaults = {'library_dirs': os.pathsep.join(default_lib_dirs),
                    'include_dirs': os.pathsep.join(default_include_dirs),
                    'runtime_library_dirs': os.pathsep.join(default_runtime_dirs),
                    'rpath': '',
                    'src_dirs': os.pathsep.join(default_src_dirs),
                    'search_static_first': str(self.search_static_first),
                    'extra_compile_args': '', 'extra_link_args': ''}
        self.cp = ConfigParser(defaults)
        self.files = []
        self.files.extend(get_standard_file('.numpy-site.cfg'))
        self.files.extend(get_standard_file('site.cfg'))
        self.parse_config_files()

        if self.section is not None:
            self.search_static_first = self.cp.getboolean(
                self.section, 'search_static_first')
        assert isinstance(self.search_static_first, int)

    def parse_config_files(self):
        self.cp.read(self.files)
        if not self.cp.has_section(self.section):
            if self.section is not None:
                self.cp.add_section(self.section)

    def calc_libraries_info(self):
        libs = self.get_libraries()
        dirs = self.get_lib_dirs()
        # The extensions use runtime_library_dirs
        r_dirs = self.get_runtime_lib_dirs()
        # Intrinsic distutils use rpath, we simply append both entries
        # as though they were one entry
        r_dirs.extend(self.get_runtime_lib_dirs(key='rpath'))
        info = {}
        for lib in libs:
            i = self.check_libs(dirs, [lib])
            if i is not None:
                dict_append(info, **i)
            else:
                log.info('Library %s was not found. Ignoring' % (lib))

            if r_dirs:
                i = self.check_libs(r_dirs, [lib])
                if i is not None:
                    # Swap library keywords found to runtime_library_dirs
                    # the libraries are insisting on the user having defined
                    # them using the library_dirs, and not necessarily by
                    # runtime_library_dirs
                    del i['libraries']
                    i['runtime_library_dirs'] = i.pop('library_dirs')
                    dict_append(info, **i)
                else:
                    log.info('Runtime library %s was not found. Ignoring' % (lib))

        return info

    def set_info(self, **info):
        if info:
            lib_info = self.calc_libraries_info()
            dict_append(info, **lib_info)
            # Update extra information
            extra_info = self.calc_extra_info()
            dict_append(info, **extra_info)
        self.saved_results[self.__class__.__name__] = info

    def get_option_single(self, *options):
        """ Ensure that only one of `options` are found in the section

        Parameters
        ----------
        *options : list of str
           a list of options to be found in the section (``self.section``)

        Returns
        -------
        str :
            the option that is uniquely found in the section

        Raises
        ------
        AliasedOptionError :
            in case more than one of the options are found
        """
        found = [self.cp.has_option(self.section, opt) for opt in options]
        if sum(found) == 1:
            return options[found.index(True)]
        elif sum(found) == 0:
            # nothing is found anyways
            return options[0]

        # Else we have more than 1 key found
        if AliasedOptionError.__doc__ is None:
            raise AliasedOptionError()
        raise AliasedOptionError(AliasedOptionError.__doc__.format(
            section=self.section, options='[{}]'.format(', '.join(options))))


    def has_info(self):
        return self.__class__.__name__ in self.saved_results

    def calc_extra_info(self):
        """ Updates the information in the current information with
        respect to these flags:
          extra_compile_args
          extra_link_args
        """
        info = {}
        for key in ['extra_compile_args', 'extra_link_args']:
            # Get values
            opt = self.cp.get(self.section, key)
            opt = _shell_utils.NativeParser.split(opt)
            if opt:
                tmp = {key: opt}
                dict_append(info, **tmp)
        return info

    def get_info(self, notfound_action=0):
        """ Return a dictionary with items that are compatible
            with numpy.distutils.setup keyword arguments.
        """
        flag = 0
        if not self.has_info():
            flag = 1
            log.info(self.__class__.__name__ + ':')
            if hasattr(self, 'calc_info'):
                self.calc_info()
            if notfound_action:
                if not self.has_info():
                    if notfound_action == 1:
                        warnings.warn(self.notfounderror.__doc__, stacklevel=2)
                    elif notfound_action == 2:
                        raise self.notfounderror(self.notfounderror.__doc__)
                    else:
                        raise ValueError(repr(notfound_action))

            if not self.has_info():
                log.info('  NOT AVAILABLE')
                self.set_info()
            else:
                log.info('  FOUND:')

        res = self.saved_results.get(self.__class__.__name__)
        if log.get_threshold() <= log.INFO and flag:
            for k, v in res.items():
                v = str(v)
                if k in ['sources', 'libraries'] and len(v) > 270:
                    v = v[:120] + '...\n...\n...' + v[-120:]
                log.info('    %s = %s', k, v)
            log.info('')

        return copy.deepcopy(res)

    def get_paths(self, section, key):
        dirs = self.cp.get(section, key).split(os.pathsep)
        env_var = self.dir_env_var
        if env_var:
            if is_sequence(env_var):
                e0 = env_var[-1]
                for e in env_var:
                    if e in os.environ:
                        e0 = e
                        break
                if not env_var[0] == e0:
                    log.info('Setting %s=%s' % (env_var[0], e0))
                env_var = e0
        if env_var and env_var in os.environ:
            d = os.environ[env_var]
            if d == 'None':
                log.info('Disabled %s: %s',
                         self.__class__.__name__, '(%s is None)'
                         % (env_var,))
                return []
            if os.path.isfile(d):
                dirs = [os.path.dirname(d)] + dirs
                l = getattr(self, '_lib_names', [])
                if len(l) == 1:
                    b = os.path.basename(d)
                    b = os.path.splitext(b)[0]
                    if b[:3] == 'lib':
                        log.info('Replacing _lib_names[0]==%r with %r' \
                              % (self._lib_names[0], b[3:]))
                        self._lib_names[0] = b[3:]
            else:
                ds = d.split(os.pathsep)
                ds2 = []
                for d in ds:
                    if os.path.isdir(d):
                        ds2.append(d)
                        for dd in ['include', 'lib']:
                            d1 = os.path.join(d, dd)
                            if os.path.isdir(d1):
                                ds2.append(d1)
                dirs = ds2 + dirs
        default_dirs = self.cp.get(self.section, key).split(os.pathsep)
        dirs.extend(default_dirs)
        ret = []
        for d in dirs:
            if len(d) > 0 and not os.path.isdir(d):
                warnings.warn('Specified path %s is invalid.' % d, stacklevel=2)
                continue

            if d not in ret:
                ret.append(d)

        log.debug('( %s = %s )', key, ':'.join(ret))
        return ret

    def get_lib_dirs(self, key='library_dirs'):
        return self.get_paths(self.section, key)

    def get_runtime_lib_dirs(self, key='runtime_library_dirs'):
        path = self.get_paths(self.section, key)
        if path == ['']:
            path = []
        return path

    def get_include_dirs(self, key='include_dirs'):
        return self.get_paths(self.section, key)

    def get_src_dirs(self, key='src_dirs'):
        return self.get_paths(self.section, key)

    def get_libs(self, key, default):
        try:
            libs = self.cp.get(self.section, key)
        except NoOptionError:
            if not default:
                return []
            if is_string(default):
                return [default]
            return default
        return [b for b in [a.strip() for a in libs.split(',')] if b]

    def get_libraries(self, key='libraries'):
        if hasattr(self, '_lib_names'):
            return self.get_libs(key, default=self._lib_names)
        else:
            return self.get_libs(key, '')

    def library_extensions(self):
        c = customized_ccompiler()
        static_exts = []
        if c.compiler_type != 'msvc':
            # MSVC doesn't understand binutils
            static_exts.append('.a')
        if sys.platform == 'win32':
            static_exts.append('.lib')  # .lib is used by MSVC and others
        if self.search_static_first:
            exts = static_exts + [so_ext]
        else:
            exts = [so_ext] + static_exts
        if sys.platform == 'cygwin':
            exts.append('.dll.a')
        if sys.platform == 'darwin':
            exts.append('.dylib')
        return exts

    def check_libs(self, lib_dirs, libs, opt_libs=[]):
        """If static or shared libraries are available then return
        their info dictionary.

        Checks for all libraries as shared libraries first, then
        static (or vice versa if self.search_static_first is True).
        """
        exts = self.library_extensions()
        info = None
        for ext in exts:
            info = self._check_libs(lib_dirs, libs, opt_libs, [ext])
            if info is not None:
                break
        if not info:
            log.info('  libraries %s not found in %s', ','.join(libs),
                     lib_dirs)
        return info

    def check_libs2(self, lib_dirs, libs, opt_libs=[]):
        """If static or shared libraries are available then return
        their info dictionary.

        Checks each library for shared or static.
        """
        exts = self.library_extensions()
        info = self._check_libs(lib_dirs, libs, opt_libs, exts)
        if not info:
            log.info('  libraries %s not found in %s', ','.join(libs),
                     lib_dirs)

        return info

    def _find_lib(self, lib_dir, lib, exts):
        assert is_string(lib_dir)
        # under windows first try without 'lib' prefix
        if sys.platform == 'win32':
            lib_prefixes = ['', 'lib']
        else:
            lib_prefixes = ['lib']
        # for each library name, see if we can find a file for it.
        for ext in exts:
            for prefix in lib_prefixes:
                p = self.combine_paths(lib_dir, prefix + lib + ext)
                if p:
                    break
            if p:
                assert len(p) == 1
                # ??? splitext on p[0] would do this for cygwin
                # doesn't seem correct
                if ext == '.dll.a':
                    lib += '.dll'
                if ext == '.lib':
                    lib = prefix + lib
                return lib

        return False

    def _find_libs(self, lib_dirs, libs, exts):
        # make sure we preserve the order of libs, as it can be important
        found_dirs, found_libs = [], []
        for lib in libs:
            for lib_dir in lib_dirs:
                found_lib = self._find_lib(lib_dir, lib, exts)
                if found_lib:
                    found_libs.append(found_lib)
                    if lib_dir not in found_dirs:
                        found_dirs.append(lib_dir)
                    break
        return found_dirs, found_libs

    def _check_libs(self, lib_dirs, libs, opt_libs, exts):
        """Find mandatory and optional libs in expected paths.

        Missing optional libraries are silently forgotten.
        """
        if not is_sequence(lib_dirs):
            lib_dirs = [lib_dirs]
        # First, try to find the mandatory libraries
        found_dirs, found_libs = self._find_libs(lib_dirs, libs, exts)
        if len(found_libs) > 0 and len(found_libs) == len(libs):
            # Now, check for optional libraries
            opt_found_dirs, opt_found_libs = self._find_libs(lib_dirs, opt_libs, exts)
            found_libs.extend(opt_found_libs)
            for lib_dir in opt_found_dirs:
                if lib_dir not in found_dirs:
                    found_dirs.append(lib_dir)
            info = {'libraries': found_libs, 'library_dirs': found_dirs}
            return info
        else:
            return None

    def combine_paths(self, *args):
        """Return a list of existing paths composed by all combinations
        of items from the arguments.
        """
        return combine_paths(*args)


class fft_opt_info(system_info):

    def calc_info(self):
        info = {}
        fftw_info = get_info('fftw3') or get_info('fftw2') or get_info('dfftw')
        djbfft_info = get_info('djbfft')
        if fftw_info:
            dict_append(info, **fftw_info)
            if djbfft_info:
                dict_append(info, **djbfft_info)
            self.set_info(**info)
            return


class fftw_info(system_info):
    #variables to override
    section = 'fftw'
    dir_env_var = 'FFTW'
    notfounderror = FFTWNotFoundError
    ver_info = [{'name':'fftw3',
                    'libs':['fftw3'],
                    'includes':['fftw3.h'],
                    'macros':[('SCIPY_FFTW3_H', None)]},
                  {'name':'fftw2',
                    'libs':['rfftw', 'fftw'],
                    'includes':['fftw.h', 'rfftw.h'],
                    'macros':[('SCIPY_FFTW_H', None)]}]

    def calc_ver_info(self, ver_param):
        """Returns True on successful version detection, else False"""
        lib_dirs = self.get_lib_dirs()
        incl_dirs = self.get_include_dirs()

        opt = self.get_option_single(self.section + '_libs', 'libraries')
        libs = self.get_libs(opt, ver_param['libs'])
        info = self.check_libs(lib_dirs, libs)
        if info is not None:
            flag = 0
            for d in incl_dirs:
                if len(self.combine_paths(d, ver_param['includes'])) \
                   == len(ver_param['includes']):
                    dict_append(info, include_dirs=[d])
                    flag = 1
                    break
            if flag:
                dict_append(info, define_macros=ver_param['macros'])
            else:
                info = None
        if info is not None:
            self.set_info(**info)
            return True
        else:
            log.info('  %s not found' % (ver_param['name']))
            return False

    def calc_info(self):
        for i in self.ver_info:
            if self.calc_ver_info(i):
                break


class fftw2_info(fftw_info):
    #variables to override
    section = 'fftw'
    dir_env_var = 'FFTW'
    notfounderror = FFTWNotFoundError
    ver_info = [{'name':'fftw2',
                    'libs':['rfftw', 'fftw'],
                    'includes':['fftw.h', 'rfftw.h'],
                    'macros':[('SCIPY_FFTW_H', None)]}
                  ]


class fftw3_info(fftw_info):
    #variables to override
    section = 'fftw3'
    dir_env_var = 'FFTW3'
    notfounderror = FFTWNotFoundError
    ver_info = [{'name':'fftw3',
                    'libs':['fftw3'],
                    'includes':['fftw3.h'],
                    'macros':[('SCIPY_FFTW3_H', None)]},
                  ]

    
class fftw3_armpl_info(fftw_info):
    section = 'fftw3'
    dir_env_var = 'ARMPL_DIR'
    notfounderror = FFTWNotFoundError
    ver_info = [{'name': 'fftw3',
                    'libs': ['armpl_lp64_mp'],
                    'includes': ['fftw3.h'],
                    'macros': [('SCIPY_FFTW3_H', None)]}]


class dfftw_info(fftw_info):
    section = 'fftw'
    dir_env_var = 'FFTW'
    ver_info = [{'name':'dfftw',
                    'libs':['drfftw', 'dfftw'],
                    'includes':['dfftw.h', 'drfftw.h'],
                    'macros':[('SCIPY_DFFTW_H', None)]}]


class sfftw_info(fftw_info):
    section = 'fftw'
    dir_env_var = 'FFTW'
    ver_info = [{'name':'sfftw',
                    'libs':['srfftw', 'sfftw'],
                    'includes':['sfftw.h', 'srfftw.h'],
                    'macros':[('SCIPY_SFFTW_H', None)]}]


class fftw_threads_info(fftw_info):
    section = 'fftw'
    dir_env_var = 'FFTW'
    ver_info = [{'name':'fftw threads',
                    'libs':['rfftw_threads', 'fftw_threads'],
                    'includes':['fftw_threads.h', 'rfftw_threads.h'],
                    'macros':[('SCIPY_FFTW_THREADS_H', None)]}]


class dfftw_threads_info(fftw_info):
    section = 'fftw'
    dir_env_var = 'FFTW'
    ver_info = [{'name':'dfftw threads',
                    'libs':['drfftw_threads', 'dfftw_threads'],
                    'includes':['dfftw_threads.h', 'drfftw_threads.h'],
                    'macros':[('SCIPY_DFFTW_THREADS_H', None)]}]


class sfftw_threads_info(fftw_info):
    section = 'fftw'
    dir_env_var = 'FFTW'
    ver_info = [{'name':'sfftw threads',
                    'libs':['srfftw_threads', 'sfftw_threads'],
                    'includes':['sfftw_threads.h', 'srfftw_threads.h'],
                    'macros':[('SCIPY_SFFTW_THREADS_H', None)]}]


class djbfft_info(system_info):
    section = 'djbfft'
    dir_env_var = 'DJBFFT'
    notfounderror = DJBFFTNotFoundError

    def get_paths(self, section, key):
        pre_dirs = system_info.get_paths(self, section, key)
        dirs = []
        for d in pre_dirs:
            dirs.extend(self.combine_paths(d, ['djbfft']) + [d])
        return [d for d in dirs if os.path.isdir(d)]

    def calc_info(self):
        lib_dirs = self.get_lib_dirs()
        incl_dirs = self.get_include_dirs()
        info = None
        for d in lib_dirs:
            p = self.combine_paths(d, ['djbfft.a'])
            if p:
                info = {'extra_objects': p}
                break
            p = self.combine_paths(d, ['libdjbfft.a', 'libdjbfft' + so_ext])
            if p:
                info = {'libraries': ['djbfft'], 'library_dirs': [d]}
                break
        if info is None:
            return
        for d in incl_dirs:
            if len(self.combine_paths(d, ['fftc8.h', 'fftfreq.h'])) == 2:
                dict_append(info, include_dirs=[d],
                            define_macros=[('SCIPY_DJBFFT_H', None)])
                self.set_info(**info)
                return
        return


class mkl_info(system_info):
    section = 'mkl'
    dir_env_var = 'MKLROOT'
    _lib_mkl = ['mkl_rt']

    def get_mkl_rootdir(self):
        mklroot = os.environ.get('MKLROOT', None)
        if mklroot is not None:
            return mklroot
        paths = os.environ.get('LD_LIBRARY_PATH', '').split(os.pathsep)
        ld_so_conf = '/etc/ld.so.conf'
        if os.path.isfile(ld_so_conf):
            with open(ld_so_conf) as f:
                for d in f:
                    d = d.strip()
                    if d:
                        paths.append(d)
        intel_mkl_dirs = []
        for path in paths:
            path_atoms = path.split(os.sep)
            for m in path_atoms:
                if m.startswith('mkl'):
                    d = os.sep.join(path_atoms[:path_atoms.index(m) + 2])
                    intel_mkl_dirs.append(d)
                    break
        for d in paths:
            dirs = glob(os.path.join(d, 'mkl', '*'))
            dirs += glob(os.path.join(d, 'mkl*'))
            for sub_dir in dirs:
                if os.path.isdir(os.path.join(sub_dir, 'lib')):
                    return sub_dir
        return None

    def __init__(self):
        mklroot = self.get_mkl_rootdir()
        if mklroot is None:
            system_info.__init__(self)
        else:
            from .cpuinfo import cpu
            if cpu.is_Itanium():
                plt = '64'
            elif cpu.is_Intel() and cpu.is_64bit():
                plt = 'intel64'
            else:
                plt = '32'
            system_info.__init__(
                self,
                default_lib_dirs=[os.path.join(mklroot, 'lib', plt)],
                default_include_dirs=[os.path.join(mklroot, 'include')])

    def calc_info(self):
        lib_dirs = self.get_lib_dirs()
        incl_dirs = self.get_include_dirs()
        opt = self.get_option_single('mkl_libs', 'libraries')
        mkl_libs = self.get_libs(opt, self._lib_mkl)
        info = self.check_libs2(lib_dirs, mkl_libs)
        if info is None:
            return
        dict_append(info,
                    define_macros=[('SCIPY_MKL_H', None),
                                   ('HAVE_CBLAS', None)],
                    include_dirs=incl_dirs)
        if sys.platform == 'win32':
            pass  # win32 has no pthread library
        else:
            dict_append(info, libraries=['pthread'])
        self.set_info(**info)


class lapack_mkl_info(mkl_info):
    pass


class blas_mkl_info(mkl_info):
    pass


class ssl2_info(system_info):
    section = 'ssl2'
    dir_env_var = 'SSL2_DIR'
    # Multi-threaded version. Python itself must be built by Fujitsu compiler.
    _lib_ssl2 = ['fjlapackexsve']
    # Single-threaded version
    #_lib_ssl2 = ['fjlapacksve']

    def get_tcsds_rootdir(self):
        tcsdsroot = os.environ.get('TCSDS_PATH', None)
        if tcsdsroot is not None:
            return tcsdsroot
        return None

    def __init__(self):
        tcsdsroot = self.get_tcsds_rootdir()
        if tcsdsroot is None:
            system_info.__init__(self)
        else:
            system_info.__init__(
                self,
                default_lib_dirs=[os.path.join(tcsdsroot, 'lib64')],
                default_include_dirs=[os.path.join(tcsdsroot,
                    'clang-comp/include')])

    def calc_info(self):
        tcsdsroot = self.get_tcsds_rootdir()

        lib_dirs = self.get_lib_dirs()
        if lib_dirs is None:
            lib_dirs = os.path.join(tcsdsroot, 'lib64')

        incl_dirs = self.get_include_dirs()
        if incl_dirs is None:
            incl_dirs = os.path.join(tcsdsroot, 'clang-comp/include')

        ssl2_libs = self.get_libs('ssl2_libs', self._lib_ssl2)

        info = self.check_libs2(lib_dirs, ssl2_libs)
        if info is None:
            return
        dict_append(info,
                    define_macros=[('HAVE_CBLAS', None),
                                   ('HAVE_SSL2', 1)],
                    include_dirs=incl_dirs,)
        self.set_info(**info)


class lapack_ssl2_info(ssl2_info):
    pass


class blas_ssl2_info(ssl2_info):
    pass



class armpl_info(system_info):
    section = 'armpl'
    dir_env_var = 'ARMPL_DIR'
    _lib_armpl = ['armpl_lp64_mp']

    def calc_info(self):
        lib_dirs = self.get_lib_dirs()
        incl_dirs = self.get_include_dirs()
        armpl_libs = self.get_libs('armpl_libs', self._lib_armpl)
        info = self.check_libs2(lib_dirs, armpl_libs)
        if info is None:
            return
        dict_append(info,
                    define_macros=[('SCIPY_MKL_H', None),
                                   ('HAVE_CBLAS', None)],
                    include_dirs=incl_dirs)
        self.set_info(**info)

class lapack_armpl_info(armpl_info):
    pass

class blas_armpl_info(armpl_info):
    pass


class atlas_info(system_info):
    section = 'atlas'
    dir_env_var = 'ATLAS'
    _lib_names = ['f77blas', 'cblas']
    if sys.platform[:7] == 'freebsd':
        _lib_atlas = ['atlas_r']
        _lib_lapack = ['alapack_r']
    else:
        _lib_atlas = ['atlas']
        _lib_lapack = ['lapack']

    notfounderror = AtlasNotFoundError

    def get_paths(self, section, key):
        pre_dirs = system_info.get_paths(self, section, key)
        dirs = []
        for d in pre_dirs:
            dirs.extend(self.combine_paths(d, ['atlas*', 'ATLAS*',
                                         'sse', '3dnow', 'sse2']) + [d])
        return [d for d in dirs if os.path.isdir(d)]

    def calc_info(self):
        lib_dirs = self.get_lib_dirs()
        info = {}
        opt = self.get_option_single('atlas_libs', 'libraries')
        atlas_libs = self.get_libs(opt, self._lib_names + self._lib_atlas)
        lapack_libs = self.get_libs('lapack_libs', self._lib_lapack)
        atlas = None
        lapack = None
        atlas_1 = None
        for d in lib_dirs:
            atlas = self.check_libs2(d, atlas_libs, [])
            if atlas is not None:
                lib_dirs2 = [d] + self.combine_paths(d, ['atlas*', 'ATLAS*'])
                lapack = self.check_libs2(lib_dirs2, lapack_libs, [])
                if lapack is not None:
                    break
            if atlas:
                atlas_1 = atlas
        log.info(self.__class__)
        if atlas is None:
            atlas = atlas_1
        if atlas is None:
            return
        include_dirs = self.get_include_dirs()
        h = (self.combine_paths(lib_dirs + include_dirs, 'cblas.h') or [None])
        h = h[0]
        if h:
            h = os.path.dirname(h)
            dict_append(info, include_dirs=[h])
        info['language'] = 'c'
        if lapack is not None:
            dict_append(info, **lapack)
            dict_append(info, **atlas)
        elif 'lapack_atlas' in atlas['libraries']:
            dict_append(info, **atlas)
            dict_append(info,
                        define_macros=[('ATLAS_WITH_LAPACK_ATLAS', None)])
            self.set_info(**info)
            return
        else:
            dict_append(info, **atlas)
            dict_append(info, define_macros=[('ATLAS_WITHOUT_LAPACK', None)])
            message = textwrap.dedent("""
                *********************************************************************
                    Could not find lapack library within the ATLAS installation.
                *********************************************************************
                """)
            warnings.warn(message, stacklevel=2)
            self.set_info(**info)
            return

        # Check if lapack library is complete, only warn if it is not.
        lapack_dir = lapack['library_dirs'][0]
        lapack_name = lapack['libraries'][0]
        lapack_lib = None
        lib_prefixes = ['lib']
        if sys.platform == 'win32':
            lib_prefixes.append('')
        for e in self.library_extensions():
            for prefix in lib_prefixes:
                fn = os.path.join(lapack_dir, prefix + lapack_name + e)
                if os.path.exists(fn):
                    lapack_lib = fn
                    break
            if lapack_lib:
                break
        if lapack_lib is not None:
            sz = os.stat(lapack_lib)[6]
            if sz <= 4000 * 1024:
                message = textwrap.dedent("""
                    *********************************************************************
                        Lapack library (from ATLAS) is probably incomplete:
                          size of %s is %sk (expected >4000k)

                        Follow the instructions in the KNOWN PROBLEMS section of the file
                        numpy/INSTALL.txt.
                    *********************************************************************
                    """) % (lapack_lib, sz / 1024)
                warnings.warn(message, stacklevel=2)
            else:
                info['language'] = 'f77'

        atlas_version, atlas_extra_info = get_atlas_version(**atlas)
        dict_append(info, **atlas_extra_info)

        self.set_info(**info)


class atlas_blas_info(atlas_info):
    _lib_names = ['f77blas', 'cblas']

    def calc_info(self):
        lib_dirs = self.get_lib_dirs()
        info = {}
        opt = self.get_option_single('atlas_libs', 'libraries')
        atlas_libs = self.get_libs(opt, self._lib_names + self._lib_atlas)
        atlas = self.check_libs2(lib_dirs, atlas_libs, [])
        if atlas is None:
            return
        include_dirs = self.get_include_dirs()
        h = (self.combine_paths(lib_dirs + include_dirs, 'cblas.h') or [None])
        h = h[0]
        if h:
            h = os.path.dirname(h)
            dict_append(info, include_dirs=[h])
        info['language'] = 'c'
        info['define_macros'] = [('HAVE_CBLAS', None)]

        atlas_version, atlas_extra_info = get_atlas_version(**atlas)
        dict_append(atlas, **atlas_extra_info)

        dict_append(info, **atlas)

        self.set_info(**info)
        return


class atlas_threads_info(atlas_info):
    dir_env_var = ['PTATLAS', 'ATLAS']
    _lib_names = ['ptf77blas', 'ptcblas']


class atlas_blas_threads_info(atlas_blas_info):
    dir_env_var = ['PTATLAS', 'ATLAS']
    _lib_names = ['ptf77blas', 'ptcblas']


class lapack_atlas_info(atlas_info):
    _lib_names = ['lapack_atlas'] + atlas_info._lib_names


class lapack_atlas_threads_info(atlas_threads_info):
    _lib_names = ['lapack_atlas'] + atlas_threads_info._lib_names


class atlas_3_10_info(atlas_info):
    _lib_names = ['satlas']
    _lib_atlas = _lib_names
    _lib_lapack = _lib_names


class atlas_3_10_blas_info(atlas_3_10_info):
    _lib_names = ['satlas']

    def calc_info(self):
        lib_dirs = self.get_lib_dirs()
        info = {}
        opt = self.get_option_single('atlas_lib', 'libraries')
        atlas_libs = self.get_libs(opt, self._lib_names)
        atlas = self.check_libs2(lib_dirs, atlas_libs, [])
        if atlas is None:
            return
        include_dirs = self.get_include_dirs()
        h = (self.combine_paths(lib_dirs + include_dirs, 'cblas.h') or [None])
        h = h[0]
        if h:
            h = os.path.dirname(h)
            dict_append(info, include_dirs=[h])
        info['language'] = 'c'
        info['define_macros'] = [('HAVE_CBLAS', None)]

        atlas_version, atlas_extra_info = get_atlas_version(**atlas)
        dict_append(atlas, **atlas_extra_info)

        dict_append(info, **atlas)

        self.set_info(**info)
        return


class atlas_3_10_threads_info(atlas_3_10_info):
    dir_env_var = ['PTATLAS', 'ATLAS']
    _lib_names = ['tatlas']
    _lib_atlas = _lib_names
    _lib_lapack = _lib_names


class atlas_3_10_blas_threads_info(atlas_3_10_blas_info):
    dir_env_var = ['PTATLAS', 'ATLAS']
    _lib_names = ['tatlas']


class lapack_atlas_3_10_info(atlas_3_10_info):
    pass


class lapack_atlas_3_10_threads_info(atlas_3_10_threads_info):
    pass


class lapack_info(system_info):
    section = 'lapack'
    dir_env_var = 'LAPACK'
    _lib_names = ['lapack']
    notfounderror = LapackNotFoundError

    def calc_info(self):
        lib_dirs = self.get_lib_dirs()

        opt = self.get_option_single('lapack_libs', 'libraries')
        lapack_libs = self.get_libs(opt, self._lib_names)
        info = self.check_libs(lib_dirs, lapack_libs, [])
        if info is None:
            return
        info['language'] = 'f77'
        self.set_info(**info)


class lapack_src_info(system_info):
    # LAPACK_SRC is deprecated, please do not use this!
    # Build or install a BLAS library via your package manager or from
    # source separately.
    section = 'lapack_src'
    dir_env_var = 'LAPACK_SRC'
    notfounderror = LapackSrcNotFoundError

    def get_paths(self, section, key):
        pre_dirs = system_info.get_paths(self, section, key)
        dirs = []
        for d in pre_dirs:
            dirs.extend([d] + self.combine_paths(d, ['LAPACK*/SRC', 'SRC']))
        return [d for d in dirs if os.path.isdir(d)]

    def calc_info(self):
        src_dirs = self.get_src_dirs()
        src_dir = ''
        for d in src_dirs:
            if os.path.isfile(os.path.join(d, 'dgesv.f')):
                src_dir = d
                break
        if not src_dir:
            #XXX: Get sources from netlib. May be ask first.
            return
        # The following is extracted from LAPACK-3.0/SRC/Makefile.
        # Added missing names from lapack-lite-3.1.1/SRC/Makefile
        # while keeping removed names for Lapack-3.0 compatibility.
        allaux = '''
        ilaenv ieeeck lsame lsamen xerbla
        iparmq
        '''  # *.f
        laux = '''
        bdsdc bdsqr disna labad lacpy ladiv lae2 laebz laed0 laed1
        laed2 laed3 laed4 laed5 laed6 laed7 laed8 laed9 laeda laev2
        lagtf lagts lamch lamrg lanst lapy2 lapy3 larnv larrb larre
        larrf lartg laruv las2 lascl lasd0 lasd1 lasd2 lasd3 lasd4
        lasd5 lasd6 lasd7 lasd8 lasd9 lasda lasdq lasdt laset lasq1
        lasq2 lasq3 lasq4 lasq5 lasq6 lasr lasrt lassq lasv2 pttrf
        stebz stedc steqr sterf

        larra larrc larrd larr larrk larrj larrr laneg laisnan isnan
        lazq3 lazq4
        '''  # [s|d]*.f
        lasrc = '''
        gbbrd gbcon gbequ gbrfs gbsv gbsvx gbtf2 gbtrf gbtrs gebak
        gebal gebd2 gebrd gecon geequ gees geesx geev geevx gegs gegv
        gehd2 gehrd gelq2 gelqf gels gelsd gelss gelsx gelsy geql2
        geqlf geqp3 geqpf geqr2 geqrf gerfs gerq2 gerqf gesc2 gesdd
        gesv gesvd gesvx getc2 getf2 getrf getri getrs ggbak ggbal
        gges ggesx ggev ggevx ggglm gghrd gglse ggqrf ggrqf ggsvd
        ggsvp gtcon gtrfs gtsv gtsvx gttrf gttrs gtts2 hgeqz hsein
        hseqr labrd lacon laein lags2 lagtm lahqr lahrd laic1 lals0
        lalsa lalsd langb lange langt lanhs lansb lansp lansy lantb
        lantp lantr lapll lapmt laqgb laqge laqp2 laqps laqsb laqsp
        laqsy lar1v lar2v larf larfb larfg larft larfx largv larrv
        lartv larz larzb larzt laswp lasyf latbs latdf latps latrd
        latrs latrz latzm lauu2 lauum pbcon pbequ pbrfs pbstf pbsv
        pbsvx pbtf2 pbtrf pbtrs pocon poequ porfs posv posvx potf2
        potrf potri potrs ppcon ppequ pprfs ppsv ppsvx pptrf pptri
        pptrs ptcon pteqr ptrfs ptsv ptsvx pttrs ptts2 spcon sprfs
        spsv spsvx sptrf sptri sptrs stegr stein sycon syrfs sysv
        sysvx sytf2 sytrf sytri sytrs tbcon tbrfs tbtrs tgevc tgex2
        tgexc tgsen tgsja tgsna tgsy2 tgsyl tpcon tprfs tptri tptrs
        trcon trevc trexc trrfs trsen trsna trsyl trti2 trtri trtrs
        tzrqf tzrzf

        lacn2 lahr2 stemr laqr0 laqr1 laqr2 laqr3 laqr4 laqr5
        '''  # [s|c|d|z]*.f
        sd_lasrc = '''
        laexc lag2 lagv2 laln2 lanv2 laqtr lasy2 opgtr opmtr org2l
        org2r orgbr orghr orgl2 orglq orgql orgqr orgr2 orgrq orgtr
        orm2l orm2r ormbr ormhr orml2 ormlq ormql ormqr ormr2 ormr3
        ormrq ormrz ormtr rscl sbev sbevd sbevx sbgst sbgv sbgvd sbgvx
        sbtrd spev spevd spevx spgst spgv spgvd spgvx sptrd stev stevd
        stevr stevx syev syevd syevr syevx sygs2 sygst sygv sygvd
        sygvx sytd2 sytrd
        '''  # [s|d]*.f
        cz_lasrc = '''
        bdsqr hbev hbevd hbevx hbgst hbgv hbgvd hbgvx hbtrd hecon heev
        heevd heevr heevx hegs2 hegst hegv hegvd hegvx herfs hesv
        hesvx hetd2 hetf2 hetrd hetrf hetri hetrs hpcon hpev hpevd
        hpevx hpgst hpgv hpgvd hpgvx hprfs hpsv hpsvx hptrd hptrf
        hptri hptrs lacgv lacp2 lacpy lacrm lacrt ladiv laed0 laed7
        laed8 laesy laev2 lahef lanhb lanhe lanhp lanht laqhb laqhe
        laqhp larcm larnv lartg lascl laset lasr lassq pttrf rot spmv
        spr stedc steqr symv syr ung2l ung2r ungbr unghr ungl2 unglq
        ungql ungqr ungr2 ungrq ungtr unm2l unm2r unmbr unmhr unml2
        unmlq unmql unmqr unmr2 unmr3 unmrq unmrz unmtr upgtr upmtr
        '''  # [c|z]*.f
        #######
        sclaux = laux + ' econd '                  # s*.f
        dzlaux = laux + ' secnd '                  # d*.f
        slasrc = lasrc + sd_lasrc                  # s*.f
        dlasrc = lasrc + sd_lasrc                  # d*.f
        clasrc = lasrc + cz_lasrc + ' srot srscl '  # c*.f
        zlasrc = lasrc + cz_lasrc + ' drot drscl '  # z*.f
        oclasrc = ' icmax1 scsum1 '                # *.f
        ozlasrc = ' izmax1 dzsum1 '                # *.f
        sources = ['s%s.f' % f for f in (sclaux + slasrc).split()] \
                  + ['d%s.f' % f for f in (dzlaux + dlasrc).split()] \
                  + ['c%s.f' % f for f in (clasrc).split()] \
                  + ['z%s.f' % f for f in (zlasrc).split()] \
                  + ['%s.f' % f for f in (allaux + oclasrc + ozlasrc).split()]
        sources = [os.path.join(src_dir, f) for f in sources]
        # Lapack 3.1:
        src_dir2 = os.path.join(src_dir, '..', 'INSTALL')
        sources += [os.path.join(src_dir2, p + 'lamch.f') for p in 'sdcz']
        # Lapack 3.2.1:
        sources += [os.path.join(src_dir, p + 'larfp.f') for p in 'sdcz']
        sources += [os.path.join(src_dir, 'ila' + p + 'lr.f') for p in 'sdcz']
        sources += [os.path.join(src_dir, 'ila' + p + 'lc.f') for p in 'sdcz']
        # Should we check here actual existence of source files?
        # Yes, the file listing is different between 3.0 and 3.1
        # versions.
        sources = [f for f in sources if os.path.isfile(f)]
        info = {'sources': sources, 'language': 'f77'}
        self.set_info(**info)

atlas_version_c_text = r'''
/* This file is generated from numpy/distutils/system_info.py */
void ATL_buildinfo(void);
int main(void) {
  ATL_buildinfo();
  return 0;
}
'''

_cached_atlas_version = {}


def get_atlas_version(**config):
    libraries = config.get('libraries', [])
    library_dirs = config.get('library_dirs', [])
    key = (tuple(libraries), tuple(library_dirs))
    if key in _cached_atlas_version:
        return _cached_atlas_version[key]
    c = cmd_config(Distribution())
    atlas_version = None
    info = {}
    try:
        s, o = c.get_output(atlas_version_c_text,
                            libraries=libraries, library_dirs=library_dirs,
                           )
        if s and re.search(r'undefined reference to `_gfortran', o, re.M):
            s, o = c.get_output(atlas_version_c_text,
                                libraries=libraries + ['gfortran'],
                                library_dirs=library_dirs,
                               )
            if not s:
                warnings.warn(textwrap.dedent("""
                    *****************************************************
                    Linkage with ATLAS requires gfortran. Use

                      python setup.py config_fc --fcompiler=gnu95 ...

                    when building extension libraries that use ATLAS.
                    Make sure that -lgfortran is used for C++ extensions.
                    *****************************************************
                    """), stacklevel=2)
                dict_append(info, language='f90',
                            define_macros=[('ATLAS_REQUIRES_GFORTRAN', None)])
    except Exception:  # failed to get version from file -- maybe on Windows
        # look at directory name
        for o in library_dirs:
            m = re.search(r'ATLAS_(?P<version>\d+[.]\d+[.]\d+)_', o)
            if m:
                atlas_version = m.group('version')
            if atlas_version is not None:
                break

        # final choice --- look at ATLAS_VERSION environment
        #   variable
        if atlas_version is None:
            atlas_version = os.environ.get('ATLAS_VERSION', None)
        if atlas_version:
            dict_append(info, define_macros=[(
                'ATLAS_INFO', _c_string_literal(atlas_version))
            ])
        else:
            dict_append(info, define_macros=[('NO_ATLAS_INFO', -1)])
        return atlas_version or '?.?.?', info

    if not s:
        m = re.search(r'ATLAS version (?P<version>\d+[.]\d+[.]\d+)', o)
        if m:
            atlas_version = m.group('version')
    if atlas_version is None:
        if re.search(r'undefined symbol: ATL_buildinfo', o, re.M):
            atlas_version = '3.2.1_pre3.3.6'
        else:
            log.info('Status: %d', s)
            log.info('Output: %s', o)

    elif atlas_version == '3.2.1_pre3.3.6':
        dict_append(info, define_macros=[('NO_ATLAS_INFO', -2)])
    else:
        dict_append(info, define_macros=[(
            'ATLAS_INFO', _c_string_literal(atlas_version))
        ])
    result = _cached_atlas_version[key] = atlas_version, info
    return result


class lapack_opt_info(system_info):
    notfounderror = LapackNotFoundError

    # List of all known LAPACK libraries, in the default order
    lapack_order = ['armpl', 'mkl', 'ssl2', 'openblas', 'flame',
                    'accelerate', 'atlas', 'lapack']
    order_env_var_name = 'NPY_LAPACK_ORDER'
    
    def _calc_info_armpl(self):
        info = get_info('lapack_armpl')
        if info:
            self.set_info(**info)
            return True
        return False

    def _calc_info_mkl(self):
        info = get_info('lapack_mkl')
        if info:
            self.set_info(**info)
            return True
        return False

    def _calc_info_ssl2(self):
        info = get_info('lapack_ssl2')
        if info:
            self.set_info(**info)
            return True
        return False

    def _calc_info_openblas(self):
        info = get_info('openblas_lapack')
        if info:
            self.set_info(**info)
            return True
        info = get_info('openblas_clapack')
        if info:
            self.set_info(**info)
            return True
        return False

    def _calc_info_flame(self):
        info = get_info('flame')
        if info:
            self.set_info(**info)
            return True
        return False

    def _calc_info_atlas(self):
        info = get_info('atlas_3_10_threads')
        if not info:
            info = get_info('atlas_3_10')
        if not info:
            info = get_info('atlas_threads')
        if not info:
            info = get_info('atlas')
        if info:
            # Figure out if ATLAS has lapack...
            # If not we need the lapack library, but not BLAS!
            l = info.get('define_macros', [])
            if ('ATLAS_WITH_LAPACK_ATLAS', None) in l \
               or ('ATLAS_WITHOUT_LAPACK', None) in l:
                # Get LAPACK (with possible warnings)
                # If not found we don't accept anything
                # since we can't use ATLAS with LAPACK!
                lapack_info = self._get_info_lapack()
                if not lapack_info:
                    return False
                dict_append(info, **lapack_info)
            self.set_info(**info)
            return True
        return False

    def _calc_info_accelerate(self):
        info = get_info('accelerate')
        if info:
            self.set_info(**info)
            return True
        return False

    def _get_info_blas(self):
        # Default to get the optimized BLAS implementation
        info = get_info('blas_opt')
        if not info:
            warnings.warn(BlasNotFoundError.__doc__ or '', stacklevel=3)
            info_src = get_info('blas_src')
            if not info_src:
                warnings.warn(BlasSrcNotFoundError.__doc__ or '', stacklevel=3)
                return {}
            dict_append(info, libraries=[('fblas_src', info_src)])
        return info

    def _get_info_lapack(self):
        info = get_info('lapack')
        if not info:
            warnings.warn(LapackNotFoundError.__doc__ or '', stacklevel=3)
            info_src = get_info('lapack_src')
            if not info_src:
                warnings.warn(LapackSrcNotFoundError.__doc__ or '', stacklevel=3)
                return {}
            dict_append(info, libraries=[('flapack_src', info_src)])
        return info

    def _calc_info_lapack(self):
        info = self._get_info_lapack()
        if info:
            info_blas = self._get_info_blas()
            dict_append(info, **info_blas)
            dict_append(info, define_macros=[('NO_ATLAS_INFO', 1)])
            self.set_info(**info)
            return True
        return False

    def _calc_info_from_envvar(self):
        info = {}
        info['language'] = 'f77'
        info['libraries'] = []
        info['include_dirs'] = []
        info['define_macros'] = []
        info['extra_link_args'] = os.environ['NPY_LAPACK_LIBS'].split()
        self.set_info(**info)
        return True

    def _calc_info(self, name):
        return getattr(self, '_calc_info_{}'.format(name))()

    def calc_info(self):
        lapack_order, unknown_order = _parse_env_order(self.lapack_order, self.order_env_var_name)
        if len(unknown_order) > 0:
            raise ValueError("lapack_opt_info user defined "
                             "LAPACK order has unacceptable "
                             "values: {}".format(unknown_order))

        if 'NPY_LAPACK_LIBS' in os.environ:
            # Bypass autodetection, set language to F77 and use env var linker
            # flags directly
            self._calc_info_from_envvar()
            return

        for lapack in lapack_order:
            if self._calc_info(lapack):
                return

        if 'lapack' not in lapack_order:
            # Since the user may request *not* to use any library, we still need
            # to raise warnings to signal missing packages!
            warnings.warn(LapackNotFoundError.__doc__ or '', stacklevel=2)
            warnings.warn(LapackSrcNotFoundError.__doc__ or '', stacklevel=2)


class _ilp64_opt_info_mixin:
    symbol_suffix = None
    symbol_prefix = None

    def _check_info(self, info):
        macros = dict(info.get('define_macros', []))
        prefix = macros.get('BLAS_SYMBOL_PREFIX', '')
        suffix = macros.get('BLAS_SYMBOL_SUFFIX', '')

        if self.symbol_prefix not in (None, prefix):
            return False

        if self.symbol_suffix not in (None, suffix):
            return False

        return bool(info)


class lapack_ilp64_opt_info(lapack_opt_info, _ilp64_opt_info_mixin):
    notfounderror = LapackILP64NotFoundError
    lapack_order = ['openblas64_', 'openblas_ilp64']
    order_env_var_name = 'NPY_LAPACK_ILP64_ORDER'

    def _calc_info(self, name):
        info = get_info(name + '_lapack')
        if self._check_info(info):
            self.set_info(**info)
            return True
        return False


class lapack_ilp64_plain_opt_info(lapack_ilp64_opt_info):
    # Same as lapack_ilp64_opt_info, but fix symbol names
    symbol_prefix = ''
    symbol_suffix = ''


class lapack64__opt_info(lapack_ilp64_opt_info):
    symbol_prefix = ''
    symbol_suffix = '64_'


class blas_opt_info(system_info):
    notfounderror = BlasNotFoundError
    # List of all known BLAS libraries, in the default order

    blas_order = ['armpl', 'mkl', 'ssl2', 'blis', 'openblas',
                  'accelerate', 'atlas', 'blas']
    order_env_var_name = 'NPY_BLAS_ORDER'
    
    def _calc_info_armpl(self):
        info = get_info('blas_armpl')
        if info:
            self.set_info(**info)
            return True
        return False

    def _calc_info_mkl(self):
        info = get_info('blas_mkl')
        if info:
            self.set_info(**info)
            return True
        return False

    def _calc_info_ssl2(self):
        info = get_info('blas_ssl2')
        if info:
            self.set_info(**info)
            return True
        return False

    def _calc_info_blis(self):
        info = get_info('blis')
        if info:
            self.set_info(**info)
            return True
        return False

    def _calc_info_openblas(self):
        info = get_info('openblas')
        if info:
            self.set_info(**info)
            return True
        return False

    def _calc_info_atlas(self):
        info = get_info('atlas_3_10_blas_threads')
        if not info:
            info = get_info('atlas_3_10_blas')
        if not info:
            info = get_info('atlas_blas_threads')
        if not info:
            info = get_info('atlas_blas')
        if info:
            self.set_info(**info)
            return True
        return False

    def _calc_info_accelerate(self):
        info = get_info('accelerate')
        if info:
            self.set_info(**info)
            return True
        return False

    def _calc_info_blas(self):
        # Warn about a non-optimized BLAS library
        warnings.warn(BlasOptNotFoundError.__doc__ or '', stacklevel=3)
        info = {}
        dict_append(info, define_macros=[('NO_ATLAS_INFO', 1)])

        blas = get_info('blas')
        if blas:
            dict_append(info, **blas)
        else:
            # Not even BLAS was found!
            warnings.warn(BlasNotFoundError.__doc__ or '', stacklevel=3)

            blas_src = get_info('blas_src')
            if not blas_src:
                warnings.warn(BlasSrcNotFoundError.__doc__ or '', stacklevel=3)
                return False
            dict_append(info, libraries=[('fblas_src', blas_src)])

        self.set_info(**info)
        return True

    def _calc_info_from_envvar(self):
        info = {}
        info['language'] = 'f77'
        info['libraries'] = []
        info['include_dirs'] = []
        info['define_macros'] = []
        info['extra_link_args'] = os.environ['NPY_BLAS_LIBS'].split()
        if 'NPY_CBLAS_LIBS' in os.environ:
            info['define_macros'].append(('HAVE_CBLAS', None))
            info['extra_link_args'].extend(
                                        os.environ['NPY_CBLAS_LIBS'].split())
        self.set_info(**info)
        return True

    def _calc_info(self, name):
        return getattr(self, '_calc_info_{}'.format(name))()

    def calc_info(self):
        blas_order, unknown_order = _parse_env_order(self.blas_order, self.order_env_var_name)
        if len(unknown_order) > 0:
            raise ValueError("blas_opt_info user defined BLAS order has unacceptable values: {}".format(unknown_order))

        if 'NPY_BLAS_LIBS' in os.environ:
            # Bypass autodetection, set language to F77 and use env var linker
            # flags directly
            self._calc_info_from_envvar()
            return

        for blas in blas_order:
            if self._calc_info(blas):
                return

        if 'blas' not in blas_order:
            # Since the user may request *not* to use any library, we still need
            # to raise warnings to signal missing packages!
            warnings.warn(BlasNotFoundError.__doc__ or '', stacklevel=2)
            warnings.warn(BlasSrcNotFoundError.__doc__ or '', stacklevel=2)


class blas_ilp64_opt_info(blas_opt_info, _ilp64_opt_info_mixin):
    notfounderror = BlasILP64NotFoundError
    blas_order = ['openblas64_', 'openblas_ilp64']
    order_env_var_name = 'NPY_BLAS_ILP64_ORDER'

    def _calc_info(self, name):
        info = get_info(name)
        if self._check_info(info):
            self.set_info(**info)
            return True
        return False


class blas_ilp64_plain_opt_info(blas_ilp64_opt_info):
    symbol_prefix = ''
    symbol_suffix = ''


class blas64__opt_info(blas_ilp64_opt_info):
    symbol_prefix = ''
    symbol_suffix = '64_'


class cblas_info(system_info):
    section = 'cblas'
    dir_env_var = 'CBLAS'
    # No default as it's used only in blas_info
    _lib_names = []
    notfounderror = BlasNotFoundError


class blas_info(system_info):
    section = 'blas'
    dir_env_var = 'BLAS'
    _lib_names = ['blas']
    notfounderror = BlasNotFoundError

    def calc_info(self):
        lib_dirs = self.get_lib_dirs()
        opt = self.get_option_single('blas_libs', 'libraries')
        blas_libs = self.get_libs(opt, self._lib_names)
        info = self.check_libs(lib_dirs, blas_libs, [])
        if info is None:
            return
        else:
            info['include_dirs'] = self.get_include_dirs()
        if platform.system() == 'Windows':
            # The check for windows is needed because get_cblas_libs uses the
            # same compiler that was used to compile Python and msvc is
            # often not installed when mingw is being used. This rough
            # treatment is not desirable, but windows is tricky.
            info['language'] = 'f77'  # XXX: is it generally true?
            # If cblas is given as an option, use those
            cblas_info_obj = cblas_info()
            cblas_opt = cblas_info_obj.get_option_single('cblas_libs', 'libraries')
            cblas_libs = cblas_info_obj.get_libs(cblas_opt, None)
            if cblas_libs:
                info['libraries'] = cblas_libs + blas_libs
                info['define_macros'] = [('HAVE_CBLAS', None)]
        else:
            lib = self.get_cblas_libs(info)
            if lib is not None:
                info['language'] = 'c'
                info['libraries'] = lib
                info['define_macros'] = [('HAVE_CBLAS', None)]
        self.set_info(**info)

    def get_cblas_libs(self, info):
        """ Check whether we can link with CBLAS interface

        This method will search through several combinations of libraries
        to check whether CBLAS is present:

        1. Libraries in ``info['libraries']``, as is
        2. As 1. but also explicitly adding ``'cblas'`` as a library
        3. As 1. but also explicitly adding ``'blas'`` as a library
        4. Check only library ``'cblas'``
        5. Check only library ``'blas'``

        Parameters
        ----------
        info : dict
           system information dictionary for compilation and linking

        Returns
        -------
        libraries : list of str or None
            a list of libraries that enables the use of CBLAS interface.
            Returns None if not found or a compilation error occurs.

            Since 1.17 returns a list.
        """
        # primitive cblas check by looking for the header and trying to link
        # cblas or blas
        c = customized_ccompiler()
        tmpdir = tempfile.mkdtemp()
        s = textwrap.dedent("""\
            #include <cblas.h>
            int main(int argc, const char *argv[])
            {
                double a[4] = {1,2,3,4};
                double b[4] = {5,6,7,8};
                return cblas_ddot(4, a, 1, b, 1) > 10;
            }""")
        src = os.path.join(tmpdir, 'source.c')
        try:
            with open(src, 'w') as f:
                f.write(s)

            try:
                # check we can compile (find headers)
                obj = c.compile([src], output_dir=tmpdir,
                                include_dirs=self.get_include_dirs())
            except (distutils.ccompiler.CompileError, distutils.ccompiler.LinkError):
                return None

            # check we can link (find library)
            # some systems have separate cblas and blas libs.
            for libs in [info['libraries'], ['cblas'] + info['libraries'],
                         ['blas'] + info['libraries'], ['cblas'], ['blas']]:
                try:
                    c.link_executable(obj, os.path.join(tmpdir, "a.out"),
                                      libraries=libs,
                                      library_dirs=info['library_dirs'],
                                      extra_postargs=info.get('extra_link_args', []))
                    return libs
                except distutils.ccompiler.LinkError:
                    pass
        finally:
            shutil.rmtree(tmpdir)
        return None


class openblas_info(blas_info):
    section = 'openblas'
    dir_env_var = 'OPENBLAS'
    _lib_names = ['openblas']
    _require_symbols = []
    notfounderror = BlasNotFoundError

    @property
    def symbol_prefix(self):
        try:
            return self.cp.get(self.section, 'symbol_prefix')
        except NoOptionError:
            return ''

    @property
    def symbol_suffix(self):
        try:
            return self.cp.get(self.section, 'symbol_suffix')
        except NoOptionError:
            return ''

    def _calc_info(self):
        c = customized_ccompiler()

        lib_dirs = self.get_lib_dirs()

        # Prefer to use libraries over openblas_libs
        opt = self.get_option_single('openblas_libs', 'libraries')
        openblas_libs = self.get_libs(opt, self._lib_names)

        info = self.check_libs(lib_dirs, openblas_libs, [])

        if c.compiler_type == "msvc" and info is None:
            from numpy.distutils.fcompiler import new_fcompiler
            f = new_fcompiler(c_compiler=c)
            if f and f.compiler_type == 'gnu95':
                # Try gfortran-compatible library files
                info = self.check_msvc_gfortran_libs(lib_dirs, openblas_libs)
                # Skip lapack check, we'd need build_ext to do it
                skip_symbol_check = True
        elif info:
            skip_symbol_check = False
            info['language'] = 'c'

        if info is None:
            return None

        # Add extra info for OpenBLAS
        extra_info = self.calc_extra_info()
        dict_append(info, **extra_info)

        if not (skip_symbol_check or self.check_symbols(info)):
            return None

        info['define_macros'] = [('HAVE_CBLAS', None)]
        if self.symbol_prefix:
            info['define_macros'] += [('BLAS_SYMBOL_PREFIX', self.symbol_prefix)]
        if self.symbol_suffix:
            info['define_macros'] += [('BLAS_SYMBOL_SUFFIX', self.symbol_suffix)]

        return info

    def calc_info(self):
        info = self._calc_info()
        if info is not None:
            self.set_info(**info)

    def check_msvc_gfortran_libs(self, library_dirs, libraries):
        # First, find the full path to each library directory
        library_paths = []
        for library in libraries:
            for library_dir in library_dirs:
                # MinGW static ext will be .a
                fullpath = os.path.join(library_dir, library + '.a')
                if os.path.isfile(fullpath):
                    library_paths.append(fullpath)
                    break
            else:
                return None

        # Generate numpy.distutils virtual static library file
        basename = self.__class__.__name__
        tmpdir = os.path.join(os.getcwd(), 'build', basename)
        if not os.path.isdir(tmpdir):
            os.makedirs(tmpdir)

        info = {'library_dirs': [tmpdir],
                'libraries': [basename],
                'language': 'f77'}

        fake_lib_file = os.path.join(tmpdir, basename + '.fobjects')
        fake_clib_file = os.path.join(tmpdir, basename + '.cobjects')
        with open(fake_lib_file, 'w') as f:
            f.write("\n".join(library_paths))
        with open(fake_clib_file, 'w') as f:
            pass

        return info

    def check_symbols(self, info):
        res = False
        c = customized_ccompiler()

        tmpdir = tempfile.mkdtemp()

        prototypes = "\n".join("void %s%s%s();" % (self.symbol_prefix,
                                                   symbol_name,
                                                   self.symbol_suffix)
                               for symbol_name in self._require_symbols)
        calls = "\n".join("%s%s%s();" % (self.symbol_prefix,
                                         symbol_name,
                                         self.symbol_suffix)
                          for symbol_name in self._require_symbols)
        s = textwrap.dedent("""\
            %(prototypes)s
            int main(int argc, const char *argv[])
            {
                %(calls)s
                return 0;
            }""") % dict(prototypes=prototypes, calls=calls)
        src = os.path.join(tmpdir, 'source.c')
        out = os.path.join(tmpdir, 'a.out')
        # Add the additional "extra" arguments
        try:
            extra_args = info['extra_link_args']
        except Exception:
            extra_args = []
        try:
            with open(src, 'w') as f:
                f.write(s)
            obj = c.compile([src], output_dir=tmpdir)
            try:
                c.link_executable(obj, out, libraries=info['libraries'],
                                  library_dirs=info['library_dirs'],
                                  extra_postargs=extra_args)
                res = True
            except distutils.ccompiler.LinkError:
                res = False
        finally:
            shutil.rmtree(tmpdir)
        return res

class openblas_lapack_info(openblas_info):
    section = 'openblas'
    dir_env_var = 'OPENBLAS'
    _lib_names = ['openblas']
    _require_symbols = ['zungqr_']
    notfounderror = BlasNotFoundError

class openblas_clapack_info(openblas_lapack_info):
    _lib_names = ['openblas', 'lapack']

class openblas_ilp64_info(openblas_info):
    section = 'openblas_ilp64'
    dir_env_var = 'OPENBLAS_ILP64'
    _lib_names = ['openblas64']
    _require_symbols = ['dgemm_', 'cblas_dgemm']
    notfounderror = BlasILP64NotFoundError

    def _calc_info(self):
        info = super()._calc_info()
        if info is not None:
            info['define_macros'] += [('HAVE_BLAS_ILP64', None)]
        return info

class openblas_ilp64_lapack_info(openblas_ilp64_info):
    _require_symbols = ['dgemm_', 'cblas_dgemm', 'zungqr_', 'LAPACKE_zungqr']

    def _calc_info(self):
        info = super()._calc_info()
        if info:
            info['define_macros'] += [('HAVE_LAPACKE', None)]
        return info

class openblas64__info(openblas_ilp64_info):
    # ILP64 Openblas, with default symbol suffix
    section = 'openblas64_'
    dir_env_var = 'OPENBLAS64_'
    _lib_names = ['openblas64_']
    symbol_suffix = '64_'
    symbol_prefix = ''

class openblas64__lapack_info(openblas_ilp64_lapack_info, openblas64__info):
    pass

class blis_info(blas_info):
    section = 'blis'
    dir_env_var = 'BLIS'
    _lib_names = ['blis']
    notfounderror = BlasNotFoundError

    def calc_info(self):
        lib_dirs = self.get_lib_dirs()
        opt = self.get_option_single('blis_libs', 'libraries')
        blis_libs = self.get_libs(opt, self._lib_names)
        info = self.check_libs2(lib_dirs, blis_libs, [])
        if info is None:
            return

        # Add include dirs
        incl_dirs = self.get_include_dirs()
        dict_append(info,
                    language='c',
                    define_macros=[('HAVE_CBLAS', None)],
                    include_dirs=incl_dirs)
        self.set_info(**info)


class flame_info(system_info):
    """ Usage of libflame for LAPACK operations

    This requires libflame to be compiled with lapack wrappers:

    ./configure --enable-lapack2flame ...

    Be aware that libflame 5.1.0 has some missing names in the shared library, so
    if you have problems, try the static flame library.
    """
    section = 'flame'
    _lib_names = ['flame']
    notfounderror = FlameNotFoundError

    def check_embedded_lapack(self, info):
        """ libflame does not necessarily have a wrapper for fortran LAPACK, we need to check """
        c = customized_ccompiler()

        tmpdir = tempfile.mkdtemp()
        s = textwrap.dedent("""\
            void zungqr_();
            int main(int argc, const char *argv[])
            {
                zungqr_();
                return 0;
            }""")
        src = os.path.join(tmpdir, 'source.c')
        out = os.path.join(tmpdir, 'a.out')
        # Add the additional "extra" arguments
        extra_args = info.get('extra_link_args', [])
        try:
            with open(src, 'w') as f:
                f.write(s)
            obj = c.compile([src], output_dir=tmpdir)
            try:
                c.link_executable(obj, out, libraries=info['libraries'],
                                  library_dirs=info['library_dirs'],
                                  extra_postargs=extra_args)
                return True
            except distutils.ccompiler.LinkError:
                return False
        finally:
            shutil.rmtree(tmpdir)

    def calc_info(self):
        lib_dirs = self.get_lib_dirs()
        flame_libs = self.get_libs('libraries', self._lib_names)

        info = self.check_libs2(lib_dirs, flame_libs, [])
        if info is None:
            return

        # Add the extra flag args to info
        extra_info = self.calc_extra_info()
        dict_append(info, **extra_info)

        if self.check_embedded_lapack(info):
            # check if the user has supplied all information required
            self.set_info(**info)
        else:
            # Try and get the BLAS lib to see if we can get it to work
            blas_info = get_info('blas_opt')
            if not blas_info:
                # since we already failed once, this ain't going to work either
                return

            # Now we need to merge the two dictionaries
            for key in blas_info:
                if isinstance(blas_info[key], list):
                    info[key] = info.get(key, []) + blas_info[key]
                elif isinstance(blas_info[key], tuple):
                    info[key] = info.get(key, ()) + blas_info[key]
                else:
                    info[key] = info.get(key, '') + blas_info[key]

            # Now check again
            if self.check_embedded_lapack(info):
                self.set_info(**info)


class accelerate_info(system_info):
    section = 'accelerate'
    _lib_names = ['accelerate', 'veclib']
    notfounderror = BlasNotFoundError

    def calc_info(self):
        # Make possible to enable/disable from config file/env var
        libraries = os.environ.get('ACCELERATE')
        if libraries:
            libraries = [libraries]
        else:
            libraries = self.get_libs('libraries', self._lib_names)
        libraries = [lib.strip().lower() for lib in libraries]

        if (sys.platform == 'darwin' and
                not os.getenv('_PYTHON_HOST_PLATFORM', None)):
            # Use the system BLAS from Accelerate or vecLib under OSX
            args = []
            link_args = []
            if get_platform()[-4:] == 'i386' or 'intel' in get_platform() or \
               'x86_64' in get_platform() or \
               'i386' in platform.platform():
                intel = 1
            else:
                intel = 0
            if (os.path.exists('/System/Library/Frameworks'
                              '/Accelerate.framework/') and
                    'accelerate' in libraries):
                if intel:
                    args.extend(['-msse3'])
                args.extend([
                    '-I/System/Library/Frameworks/vecLib.framework/Headers'])
                link_args.extend(['-Wl,-framework', '-Wl,Accelerate'])
            elif (os.path.exists('/System/Library/Frameworks'
                                 '/vecLib.framework/') and
                      'veclib' in libraries):
                if intel:
                    args.extend(['-msse3'])
                args.extend([
                    '-I/System/Library/Frameworks/vecLib.framework/Headers'])
                link_args.extend(['-Wl,-framework', '-Wl,vecLib'])

            if args:
                self.set_info(extra_compile_args=args,
                              extra_link_args=link_args,
                              define_macros=[('NO_ATLAS_INFO', 3),
                                             ('HAVE_CBLAS', None)])

        return

class blas_src_info(system_info):
    # BLAS_SRC is deprecated, please do not use this!
    # Build or install a BLAS library via your package manager or from
    # source separately.
    section = 'blas_src'
    dir_env_var = 'BLAS_SRC'
    notfounderror = BlasSrcNotFoundError

    def get_paths(self, section, key):
        pre_dirs = system_info.get_paths(self, section, key)
        dirs = []
        for d in pre_dirs:
            dirs.extend([d] + self.combine_paths(d, ['blas']))
        return [d for d in dirs if os.path.isdir(d)]

    def calc_info(self):
        src_dirs = self.get_src_dirs()
        src_dir = ''
        for d in src_dirs:
            if os.path.isfile(os.path.join(d, 'daxpy.f')):
                src_dir = d
                break
        if not src_dir:
            #XXX: Get sources from netlib. May be ask first.
            return
        blas1 = '''
        caxpy csscal dnrm2 dzasum saxpy srotg zdotc ccopy cswap drot
        dznrm2 scasum srotm zdotu cdotc dasum drotg icamax scnrm2
        srotmg zdrot cdotu daxpy drotm idamax scopy sscal zdscal crotg
        dcabs1 drotmg isamax sdot sswap zrotg cscal dcopy dscal izamax
        snrm2 zaxpy zscal csrot ddot dswap sasum srot zcopy zswap
        scabs1
        '''
        blas2 = '''
        cgbmv chpmv ctrsv dsymv dtrsv sspr2 strmv zhemv ztpmv cgemv
        chpr dgbmv dsyr lsame ssymv strsv zher ztpsv cgerc chpr2 dgemv
        dsyr2 sgbmv ssyr xerbla zher2 ztrmv cgeru ctbmv dger dtbmv
        sgemv ssyr2 zgbmv zhpmv ztrsv chbmv ctbsv dsbmv dtbsv sger
        stbmv zgemv zhpr chemv ctpmv dspmv dtpmv ssbmv stbsv zgerc
        zhpr2 cher ctpsv dspr dtpsv sspmv stpmv zgeru ztbmv cher2
        ctrmv dspr2 dtrmv sspr stpsv zhbmv ztbsv
        '''
        blas3 = '''
        cgemm csymm ctrsm dsyrk sgemm strmm zhemm zsyr2k chemm csyr2k
        dgemm dtrmm ssymm strsm zher2k zsyrk cher2k csyrk dsymm dtrsm
        ssyr2k zherk ztrmm cherk ctrmm dsyr2k ssyrk zgemm zsymm ztrsm
        '''
        sources = [os.path.join(src_dir, f + '.f') \
                   for f in (blas1 + blas2 + blas3).split()]
        #XXX: should we check here actual existence of source files?
        sources = [f for f in sources if os.path.isfile(f)]
        info = {'sources': sources, 'language': 'f77'}
        self.set_info(**info)


class x11_info(system_info):
    section = 'x11'
    notfounderror = X11NotFoundError
    _lib_names = ['X11']

    def __init__(self):
        system_info.__init__(self,
                             default_lib_dirs=default_x11_lib_dirs,
                             default_include_dirs=default_x11_include_dirs)

    def calc_info(self):
        if sys.platform  in ['win32']:
            return
        lib_dirs = self.get_lib_dirs()
        include_dirs = self.get_include_dirs()
        opt = self.get_option_single('x11_libs', 'libraries')
        x11_libs = self.get_libs(opt, self._lib_names)
        info = self.check_libs(lib_dirs, x11_libs, [])
        if info is None:
            return
        inc_dir = None
        for d in include_dirs:
            if self.combine_paths(d, 'X11/X.h'):
                inc_dir = d
                break
        if inc_dir is not None:
            dict_append(info, include_dirs=[inc_dir])
        self.set_info(**info)


class _numpy_info(system_info):
    section = 'Numeric'
    modulename = 'Numeric'
    notfounderror = NumericNotFoundError

    def __init__(self):
        include_dirs = []
        try:
            module = __import__(self.modulename)
            prefix = []
            for name in module.__file__.split(os.sep):
                if name == 'lib':
                    break
                prefix.append(name)

            # Ask numpy for its own include path before attempting
            # anything else
            try:
                include_dirs.append(getattr(module, 'get_include')())
            except AttributeError:
                pass

            include_dirs.append(sysconfig.get_path('include'))
        except ImportError:
            pass
        py_incl_dir = sysconfig.get_path('include')
        include_dirs.append(py_incl_dir)
        py_pincl_dir = sysconfig.get_path('platinclude')
        if py_pincl_dir not in include_dirs:
            include_dirs.append(py_pincl_dir)
        for d in default_include_dirs:
            d = os.path.join(d, os.path.basename(py_incl_dir))
            if d not in include_dirs:
                include_dirs.append(d)
        system_info.__init__(self,
                             default_lib_dirs=[],
                             default_include_dirs=include_dirs)

    def calc_info(self):
        try:
            module = __import__(self.modulename)
        except ImportError:
            return
        info = {}
        macros = []
        for v in ['__version__', 'version']:
            vrs = getattr(module, v, None)
            if vrs is None:
                continue
            macros = [(self.modulename.upper() + '_VERSION',
                      _c_string_literal(vrs)),
                      (self.modulename.upper(), None)]
            break
        dict_append(info, define_macros=macros)
        include_dirs = self.get_include_dirs()
        inc_dir = None
        for d in include_dirs:
            if self.combine_paths(d,
                                  os.path.join(self.modulename,
                                               'arrayobject.h')):
                inc_dir = d
                break
        if inc_dir is not None:
            dict_append(info, include_dirs=[inc_dir])
        if info:
            self.set_info(**info)
        return


class numarray_info(_numpy_info):
    section = 'numarray'
    modulename = 'numarray'


class Numeric_info(_numpy_info):
    section = 'Numeric'
    modulename = 'Numeric'


class numpy_info(_numpy_info):
    section = 'numpy'
    modulename = 'numpy'


class numerix_info(system_info):
    section = 'numerix'

    def calc_info(self):
        which = None, None
        if os.getenv("NUMERIX"):
            which = os.getenv("NUMERIX"), "environment var"
        # If all the above fail, default to numpy.
        if which[0] is None:
            which = "numpy", "defaulted"
            try:
                import numpy  # noqa: F401
                which = "numpy", "defaulted"
            except ImportError as e:
                msg1 = str(e)
                try:
                    import Numeric  # noqa: F401
                    which = "numeric", "defaulted"
                except ImportError as e:
                    msg2 = str(e)
                    try:
                        import numarray  # noqa: F401
                        which = "numarray", "defaulted"
                    except ImportError as e:
                        msg3 = str(e)
                        log.info(msg1)
                        log.info(msg2)
                        log.info(msg3)
        which = which[0].strip().lower(), which[1]
        if which[0] not in ["numeric", "numarray", "numpy"]:
            raise ValueError("numerix selector must be either 'Numeric' "
                             "or 'numarray' or 'numpy' but the value obtained"
                             " from the %s was '%s'." % (which[1], which[0]))
        os.environ['NUMERIX'] = which[0]
        self.set_info(**get_info(which[0]))


class f2py_info(system_info):
    def calc_info(self):
        try:
            import numpy.f2py as f2py
        except ImportError:
            return
        f2py_dir = os.path.join(os.path.dirname(f2py.__file__), 'src')
        self.set_info(sources=[os.path.join(f2py_dir, 'fortranobject.c')],
                      include_dirs=[f2py_dir])
        return


class boost_python_info(system_info):
    section = 'boost_python'
    dir_env_var = 'BOOST'

    def get_paths(self, section, key):
        pre_dirs = system_info.get_paths(self, section, key)
        dirs = []
        for d in pre_dirs:
            dirs.extend([d] + self.combine_paths(d, ['boost*']))
        return [d for d in dirs if os.path.isdir(d)]

    def calc_info(self):
        src_dirs = self.get_src_dirs()
        src_dir = ''
        for d in src_dirs:
            if os.path.isfile(os.path.join(d, 'libs', 'python', 'src',
                                           'module.cpp')):
                src_dir = d
                break
        if not src_dir:
            return
        py_incl_dirs = [sysconfig.get_path('include')]
        py_pincl_dir = sysconfig.get_path('platinclude')
        if py_pincl_dir not in py_incl_dirs:
            py_incl_dirs.append(py_pincl_dir)
        srcs_dir = os.path.join(src_dir, 'libs', 'python', 'src')
        bpl_srcs = glob(os.path.join(srcs_dir, '*.cpp'))
        bpl_srcs += glob(os.path.join(srcs_dir, '*', '*.cpp'))
        info = {'libraries': [('boost_python_src',
                               {'include_dirs': [src_dir] + py_incl_dirs,
                                'sources':bpl_srcs}
                              )],
                'include_dirs': [src_dir],
                }
        if info:
            self.set_info(**info)
        return


class agg2_info(system_info):
    section = 'agg2'
    dir_env_var = 'AGG2'

    def get_paths(self, section, key):
        pre_dirs = system_info.get_paths(self, section, key)
        dirs = []
        for d in pre_dirs:
            dirs.extend([d] + self.combine_paths(d, ['agg2*']))
        return [d for d in dirs if os.path.isdir(d)]

    def calc_info(self):
        src_dirs = self.get_src_dirs()
        src_dir = ''
        for d in src_dirs:
            if os.path.isfile(os.path.join(d, 'src', 'agg_affine_matrix.cpp')):
                src_dir = d
                break
        if not src_dir:
            return
        if sys.platform == 'win32':
            agg2_srcs = glob(os.path.join(src_dir, 'src', 'platform',
                                          'win32', 'agg_win32_bmp.cpp'))
        else:
            agg2_srcs = glob(os.path.join(src_dir, 'src', '*.cpp'))
            agg2_srcs += [os.path.join(src_dir, 'src', 'platform',
                                       'X11',
                                       'agg_platform_support.cpp')]

        info = {'libraries':
                [('agg2_src',
                  {'sources': agg2_srcs,
                   'include_dirs': [os.path.join(src_dir, 'include')],
                  }
                 )],
                'include_dirs': [os.path.join(src_dir, 'include')],
                }
        if info:
            self.set_info(**info)
        return


class _pkg_config_info(system_info):
    section = None
    config_env_var = 'PKG_CONFIG'
    default_config_exe = 'pkg-config'
    append_config_exe = ''
    version_macro_name = None
    release_macro_name = None
    version_flag = '--modversion'
    cflags_flag = '--cflags'

    def get_config_exe(self):
        if self.config_env_var in os.environ:
            return os.environ[self.config_env_var]
        return self.default_config_exe

    def get_config_output(self, config_exe, option):
        cmd = config_exe + ' ' + self.append_config_exe + ' ' + option
        try:
            o = subprocess.check_output(cmd)
        except (OSError, subprocess.CalledProcessError):
            pass
        else:
            o = filepath_from_subprocess_output(o)
            return o

    def calc_info(self):
        config_exe = find_executable(self.get_config_exe())
        if not config_exe:
            log.warn('File not found: %s. Cannot determine %s info.' \
                  % (config_exe, self.section))
            return
        info = {}
        macros = []
        libraries = []
        library_dirs = []
        include_dirs = []
        extra_link_args = []
        extra_compile_args = []
        version = self.get_config_output(config_exe, self.version_flag)
        if version:
            macros.append((self.__class__.__name__.split('.')[-1].upper(),
                           _c_string_literal(version)))
            if self.version_macro_name:
                macros.append((self.version_macro_name + '_%s'
                               % (version.replace('.', '_')), None))
        if self.release_macro_name:
            release = self.get_config_output(config_exe, '--release')
            if release:
                macros.append((self.release_macro_name + '_%s'
                               % (release.replace('.', '_')), None))
        opts = self.get_config_output(config_exe, '--libs')
        if opts:
            for opt in opts.split():
                if opt[:2] == '-l':
                    libraries.append(opt[2:])
                elif opt[:2] == '-L':
                    library_dirs.append(opt[2:])
                else:
                    extra_link_args.append(opt)
        opts = self.get_config_output(config_exe, self.cflags_flag)
        if opts:
            for opt in opts.split():
                if opt[:2] == '-I':
                    include_dirs.append(opt[2:])
                elif opt[:2] == '-D':
                    if '=' in opt:
                        n, v = opt[2:].split('=')
                        macros.append((n, v))
                    else:
                        macros.append((opt[2:], None))
                else:
                    extra_compile_args.append(opt)
        if macros:
            dict_append(info, define_macros=macros)
        if libraries:
            dict_append(info, libraries=libraries)
        if library_dirs:
            dict_append(info, library_dirs=library_dirs)
        if include_dirs:
            dict_append(info, include_dirs=include_dirs)
        if extra_link_args:
            dict_append(info, extra_link_args=extra_link_args)
        if extra_compile_args:
            dict_append(info, extra_compile_args=extra_compile_args)
        if info:
            self.set_info(**info)
        return


class wx_info(_pkg_config_info):
    section = 'wx'
    config_env_var = 'WX_CONFIG'
    default_config_exe = 'wx-config'
    append_config_exe = ''
    version_macro_name = 'WX_VERSION'
    release_macro_name = 'WX_RELEASE'
    version_flag = '--version'
    cflags_flag = '--cxxflags'


class gdk_pixbuf_xlib_2_info(_pkg_config_info):
    section = 'gdk_pixbuf_xlib_2'
    append_config_exe = 'gdk-pixbuf-xlib-2.0'
    version_macro_name = 'GDK_PIXBUF_XLIB_VERSION'


class gdk_pixbuf_2_info(_pkg_config_info):
    section = 'gdk_pixbuf_2'
    append_config_exe = 'gdk-pixbuf-2.0'
    version_macro_name = 'GDK_PIXBUF_VERSION'


class gdk_x11_2_info(_pkg_config_info):
    section = 'gdk_x11_2'
    append_config_exe = 'gdk-x11-2.0'
    version_macro_name = 'GDK_X11_VERSION'


class gdk_2_info(_pkg_config_info):
    section = 'gdk_2'
    append_config_exe = 'gdk-2.0'
    version_macro_name = 'GDK_VERSION'


class gdk_info(_pkg_config_info):
    section = 'gdk'
    append_config_exe = 'gdk'
    version_macro_name = 'GDK_VERSION'


class gtkp_x11_2_info(_pkg_config_info):
    section = 'gtkp_x11_2'
    append_config_exe = 'gtk+-x11-2.0'
    version_macro_name = 'GTK_X11_VERSION'


class gtkp_2_info(_pkg_config_info):
    section = 'gtkp_2'
    append_config_exe = 'gtk+-2.0'
    version_macro_name = 'GTK_VERSION'


class xft_info(_pkg_config_info):
    section = 'xft'
    append_config_exe = 'xft'
    version_macro_name = 'XFT_VERSION'


class freetype2_info(_pkg_config_info):
    section = 'freetype2'
    append_config_exe = 'freetype2'
    version_macro_name = 'FREETYPE2_VERSION'


class amd_info(system_info):
    section = 'amd'
    dir_env_var = 'AMD'
    _lib_names = ['amd']

    def calc_info(self):
        lib_dirs = self.get_lib_dirs()

        opt = self.get_option_single('amd_libs', 'libraries')
        amd_libs = self.get_libs(opt, self._lib_names)
        info = self.check_libs(lib_dirs, amd_libs, [])
        if info is None:
            return

        include_dirs = self.get_include_dirs()

        inc_dir = None
        for d in include_dirs:
            p = self.combine_paths(d, 'amd.h')
            if p:
                inc_dir = os.path.dirname(p[0])
                break
        if inc_dir is not None:
            dict_append(info, include_dirs=[inc_dir],
                        define_macros=[('SCIPY_AMD_H', None)],
                        swig_opts=['-I' + inc_dir])

        self.set_info(**info)
        return


class umfpack_info(system_info):
    section = 'umfpack'
    dir_env_var = 'UMFPACK'
    notfounderror = UmfpackNotFoundError
    _lib_names = ['umfpack']

    def calc_info(self):
        lib_dirs = self.get_lib_dirs()

        opt = self.get_option_single('umfpack_libs', 'libraries')
        umfpack_libs = self.get_libs(opt, self._lib_names)
        info = self.check_libs(lib_dirs, umfpack_libs, [])
        if info is None:
            return

        include_dirs = self.get_include_dirs()

        inc_dir = None
        for d in include_dirs:
            p = self.combine_paths(d, ['', 'umfpack'], 'umfpack.h')
            if p:
                inc_dir = os.path.dirname(p[0])
                break
        if inc_dir is not None:
            dict_append(info, include_dirs=[inc_dir],
                        define_macros=[('SCIPY_UMFPACK_H', None)],
                        swig_opts=['-I' + inc_dir])

        dict_append(info, **get_info('amd'))

        self.set_info(**info)
        return


def combine_paths(*args, **kws):
    """ Return a list of existing paths composed by all combinations of
        items from arguments.
    """
    r = []
    for a in args:
        if not a:
            continue
        if is_string(a):
            a = [a]
        r.append(a)
    args = r
    if not args:
        return []
    if len(args) == 1:
        result = reduce(lambda a, b: a + b, map(glob, args[0]), [])
    elif len(args) == 2:
        result = []
        for a0 in args[0]:
            for a1 in args[1]:
                result.extend(glob(os.path.join(a0, a1)))
    else:
        result = combine_paths(*(combine_paths(args[0], args[1]) + args[2:]))
    log.debug('(paths: %s)', ','.join(result))
    return result

language_map = {'c': 0, 'c++': 1, 'f77': 2, 'f90': 3}
inv_language_map = {0: 'c', 1: 'c++', 2: 'f77', 3: 'f90'}


def dict_append(d, **kws):
    languages = []
    for k, v in kws.items():
        if k == 'language':
            languages.append(v)
            continue
        if k in d:
            if k in ['library_dirs', 'include_dirs',
                     'extra_compile_args', 'extra_link_args',
                     'runtime_library_dirs', 'define_macros']:
                [d[k].append(vv) for vv in v if vv not in d[k]]
            else:
                d[k].extend(v)
        else:
            d[k] = v
    if languages:
        l = inv_language_map[max([language_map.get(l, 0) for l in languages])]
        d['language'] = l
    return


def parseCmdLine(argv=(None,)):
    import optparse
    parser = optparse.OptionParser("usage: %prog [-v] [info objs]")
    parser.add_option('-v', '--verbose', action='store_true', dest='verbose',
                      default=False,
                      help='be verbose and print more messages')

    opts, args = parser.parse_args(args=argv[1:])
    return opts, args


def show_all(argv=None):
    import inspect
    if argv is None:
        argv = sys.argv
    opts, args = parseCmdLine(argv)
    if opts.verbose:
        log.set_threshold(log.DEBUG)
    else:
        log.set_threshold(log.INFO)
    show_only = []
    for n in args:
        if n[-5:] != '_info':
            n = n + '_info'
        show_only.append(n)
    show_all = not show_only
    _gdict_ = globals().copy()
    for name, c in _gdict_.items():
        if not inspect.isclass(c):
            continue
        if not issubclass(c, system_info) or c is system_info:
            continue
        if not show_all:
            if name not in show_only:
                continue
            del show_only[show_only.index(name)]
        conf = c()
        conf.verbosity = 2
        # we don't need the result, but we want
        # the side effect of printing diagnostics
        conf.get_info()
    if show_only:
        log.info('Info classes not defined: %s', ','.join(show_only))

if __name__ == "__main__":
    show_all()