text: from __future__ import absolute_import, division, print_function
  
  from functools import partial
  import json
  import os
  import re
  import time
  import datetime
  
  import jinja2
  
  from .conda_interface import PY3
  from .environ import get_dict as get_environ
  from .utils import (get_installed_packages, apply_pin_expressions, get_logger, HashableDict,
                      string_types)
  from .render import get_env_dependencies
  from .utils import copy_into, check_call_env, rm_rf, ensure_valid_spec
  from .variants import DEFAULT_COMPILERS
  from .exceptions import CondaBuildException
  from . import _load_setup_py_data
  
  
  class UndefinedNeverFail(jinja2.Undefined):
      """
      A class for Undefined jinja variables.
      This is even less strict than the default jinja2.Undefined class,
      because it permits things like {{ MY_UNDEFINED_VAR[:2] }} and
      {{ MY_UNDEFINED_VAR|int }}. This can mask lots of errors in jinja templates, so it
      should only be used for a first-pass parse, when you plan on running a 'strict'
      second pass later.
  
      Note:
          When using this class, any usage of an undefined variable in a jinja template is recorded
          in the (global) all_undefined_names class member.  Therefore, after jinja rendering,
          you can detect which undefined names were used by inspecting that list.
          Be sure to clear the all_undefined_names list before calling template.render().
      """
      all_undefined_names = []
  
      def __init__(self, hint=None, obj=jinja2.runtime.missing, name=None,
                   exc=jinja2.exceptions.UndefinedError):
          jinja2.Undefined.__init__(self, hint, obj, name, exc)
  
      # Using any of these methods on an Undefined variable
      # results in another Undefined variable.
      __add__ = __radd__ = __mul__ = __rmul__ = __div__ = __rdiv__ = \
      __truediv__ = __rtruediv__ = __floordiv__ = __rfloordiv__ = \
      __mod__ = __rmod__ = __pos__ = __neg__ = __call__ = \
      __getitem__ = __lt__ = __le__ = __gt__ = __ge__ = \
      __complex__ = __pow__ = __rpow__ = \
          lambda self, *args, **kwargs: self._return_undefined(self._undefined_name)
  
      # Accessing an attribute of an Undefined variable
      # results in another Undefined variable.
      def __getattr__(self, k):
          try:
              return object.__getattr__(self, k)
          except AttributeError:
              self._return_undefined(self._undefined_name + '.' + k)
  
      # Unlike the methods above, Python requires that these
      # few methods must always return the correct type
      __str__ = __repr__ = lambda self: self._return_value(str())
      __unicode__ = lambda self: self._return_value(u'')
      __int__ = lambda self: self._return_value(0)
      __float__ = lambda self: self._return_value(0.0)
      __nonzero__ = lambda self: self._return_value(False)
  
      def _return_undefined(self, result_name):
          # Record that this undefined variable was actually used.
          UndefinedNeverFail.all_undefined_names.append(self._undefined_name)
          return UndefinedNeverFail(hint=self._undefined_hint,
                                    obj=self._undefined_obj,
                                    name=result_name,
                                    exc=self._undefined_exception)
  
      def _return_value(self, value=None):
          # Record that this undefined variable was actually used.
          UndefinedNeverFail.all_undefined_names.append(self._undefined_name)
          return value
  
  
  class FilteredLoader(jinja2.BaseLoader):
      """
      A pass-through for the given loader, except that the loaded source is
      filtered according to any metadata selectors in the source text.
      """
  
      def __init__(self, unfiltered_loader, config):
          self._unfiltered_loader = unfiltered_loader
          self.list_templates = unfiltered_loader.list_templates
          self.config = config
  
      def get_source(self, environment, template):
          # we have circular imports here.  Do a local import
          from .metadata import select_lines, ns_cfg
          contents, filename, uptodate = self._unfiltered_loader.get_source(environment,
                                                                            template)
          return (select_lines(contents, ns_cfg(self.config),
                               variants_in_place=bool(self.config.variant)), filename, uptodate)
  
  
  def load_setup_py_data(m, setup_file='setup.py', from_recipe_dir=False, recipe_dir=None,
                         permit_undefined_jinja=True):
      _setuptools_data = None
      # we must copy the script into the work folder to avoid incompatible pyc files
      origin_setup_script = os.path.join(os.path.dirname(__file__), '_load_setup_py_data.py')
      dest_setup_script = os.path.join(m.config.work_dir, '_load_setup_py_data.py')
      copy_into(origin_setup_script, dest_setup_script)
      env = get_environ(m)
      env["CONDA_BUILD_STATE"] = "RENDER"
      if os.path.isfile(m.config.build_python):
          args = [m.config.build_python, dest_setup_script, m.config.work_dir, setup_file]
          if from_recipe_dir:
              assert recipe_dir, 'recipe_dir must be set if from_recipe_dir is True'
              args.append('--from-recipe-dir')
              args.extend(['--recipe-dir', recipe_dir])
          if permit_undefined_jinja:
              args.append('--permit-undefined-jinja')
          check_call_env(args, env=env)
          # this is a file that the subprocess will have written
          with open(os.path.join(m.config.work_dir, 'conda_build_loaded_setup_py.json')) as f:
              _setuptools_data = json.load(f)
      else:
          try:
              _setuptools_data = _load_setup_py_data.load_setup_py_data(setup_file,
                                                      from_recipe_dir=from_recipe_dir,
                                                      recipe_dir=recipe_dir,
                                                      work_dir=m.config.work_dir,
                                                      permit_undefined_jinja=permit_undefined_jinja)
          except (TypeError, OSError):
              # setup.py file doesn't yet exist.  Will get picked up in future parsings
              pass
          except ImportError as e:
              if permit_undefined_jinja:
                  log = get_logger(__name__)
                  log.debug("Reading setup.py failed due to missing modules.  This is probably OK, "
                            "since it may succeed in later passes.  Watch for incomplete recipe "
                            "info, though.")
              else:
                  raise CondaBuildException("Could not render recipe - need modules "
                                          "installed in root env.  Import error was \"{}\"".format(e))
      # cleanup: we must leave the source tree empty unless the source code is already present
      rm_rf(os.path.join(m.config.work_dir, '_load_setup_py_data.py'))
      return _setuptools_data if _setuptools_data else {}
  
  
  def load_setuptools(m, setup_file='setup.py', from_recipe_dir=False, recipe_dir=None,
                      permit_undefined_jinja=True):
      log = get_logger(__name__)
      log.warn("Deprecation notice: the load_setuptools function has been renamed to "
               "load_setup_py_data.  load_setuptools will be removed in a future release.")
      return load_setup_py_data(m, setup_file=setup_file, from_recipe_dir=from_recipe_dir,
                                recipe_dir=recipe_dir, permit_undefined_jinja=permit_undefined_jinja)
  
  
  def load_npm():
      # json module expects bytes in Python 2 and str in Python 3.
      mode_dict = {'mode': 'r', 'encoding': 'utf-8'} if PY3 else {'mode': 'rb'}
      with open('package.json', **mode_dict) as pkg:
          return json.load(pkg)
  
  
  def load_file_regex(config, load_file, regex_pattern, from_recipe_dir=False,
                      recipe_dir=None, permit_undefined_jinja=True):
      match = False
      log = get_logger(__name__)
  
      cd_to_work = False
  
      if from_recipe_dir and recipe_dir:
          load_file = os.path.abspath(os.path.join(recipe_dir, load_file))
      elif os.path.exists(config.work_dir):
          cd_to_work = True
          cwd = os.getcwd()
          os.chdir(config.work_dir)
          if not os.path.isabs(load_file):
              load_file = os.path.join(config.work_dir, load_file)
      else:
          message = ("Did not find {} file in manually specified location, and source "
                    "not downloaded yet.".format(load_file))
          if permit_undefined_jinja:
              log.debug(message)
              return {}
          else:
              raise RuntimeError(message)
  
      if os.path.isfile(load_file):
          with open(load_file, 'r') as lfile:
              match = re.search(regex_pattern, lfile.read())
      else:
          if not permit_undefined_jinja:
              raise TypeError('{} is not a file that can be read'.format(load_file))
  
      # Reset the working directory
      if cd_to_work:
          os.chdir(cwd)
  
      return match if match else None
  
  
  cached_env_dependencies = {}
  
  
  def pin_compatible(m, package_name, lower_bound=None, upper_bound=None, min_pin='x.x.x.x.x.x',
                     max_pin='x', permit_undefined_jinja=False, exact=False, bypass_env_check=False):
      """dynamically pin based on currently installed version.
  
      only mandatory input is package_name.
      upper_bound is the authoritative upper bound, if provided.  The lower bound is the the
          currently installed version.
      pin expressions are of the form 'x.x' - the number of pins is the number of x's separated
          by ``.``.
      """
      global cached_env_dependencies
      compatibility = ""
  
      # optimization: this is slow (requires solver), so better to bypass it
      # until the finalization stage.
      if not bypass_env_check and not permit_undefined_jinja:
          # this is the version split up into its component bits.
          # There are two cases considered here (so far):
          # 1. Good packages that follow semver style (if not philosophy).  For example, 1.2.3
          # 2. Evil packages that cram everything alongside a single major version.  For example, 9b
          key = (m.name(), HashableDict(m.config.variant))
          if key in cached_env_dependencies:
              pins = cached_env_dependencies[key]
          else:
              if m.is_cross and not m.build_is_host:
                  pins, _, _ = get_env_dependencies(m, 'host', m.config.variant)
              else:
                  pins, _, _ = get_env_dependencies(m, 'build', m.config.variant)
                  if m.build_is_host:
                      host_pins, _, _ = get_env_dependencies(m, 'host', m.config.variant)
                      pins.extend(host_pins)
              cached_env_dependencies[key] = pins
          versions = {p.split(' ')[0]: p.split(' ')[1:] for p in pins}
          if versions:
              if exact and versions.get(package_name):
                  compatibility = ' '.join(versions[package_name])
              else:
                  version = lower_bound or versions.get(package_name)
                  if version:
                      if hasattr(version, '__iter__') and not isinstance(version, string_types):
                          version = version[0]
                      else:
                          version = str(version)
                      if upper_bound:
                          if min_pin or lower_bound:
                              compatibility = ">=" + str(version) + ","
                          compatibility += '<{upper_bound}'.format(upper_bound=upper_bound)
                      else:
                          compatibility = apply_pin_expressions(version, min_pin, max_pin)
  
      if (not compatibility and not permit_undefined_jinja and not bypass_env_check):
          check = re.compile(r'pin_compatible\s*\(\s*[''"]{}[''"]'.format(package_name))
          if check.search(m.extract_requirements_text()):
              raise RuntimeError("Could not get compatibility information for {} package.  "
                                 "Is it one of your host dependencies?".format(package_name))
      return " ".join((package_name, compatibility)) if compatibility is not None else package_name
  
  
  def pin_subpackage_against_outputs(metadata, matching_package_keys, outputs, min_pin, max_pin,
                                     exact, permit_undefined_jinja, skip_build_id=False):
      pin = None
      if matching_package_keys:
          # two ways to match:
          #    1. only one other output named the same as the subpackage_name from the key
          #    2. whole key matches (both subpackage name and variant (used keys only))
          if len(matching_package_keys) == 1:
              key = matching_package_keys[0]
          elif len(matching_package_keys) > 1:
              key = None
              for pkg_name, variant in matching_package_keys:
                  # This matches other outputs with any keys that are common to both
                  # metadata objects. For debugging, the keys are always the (package
                  # name, used vars+values). It used to be (package name, variant) -
                  # but that was really big and hard to look at.
                  shared_vars = set(variant.keys()) & set(metadata.config.variant.keys())
                  if not shared_vars or all(variant[sv] == metadata.config.variant[sv]
                                              for sv in shared_vars):
                      key = (pkg_name, variant)
                      break
  
          if key in outputs:
              sp_m = outputs[key][1]
              if permit_undefined_jinja and not sp_m.version():
                  pin = None
              else:
                  if exact:
                      pin = " ".join([sp_m.name(), sp_m.version(),
                                      sp_m.build_id() if not skip_build_id else str(sp_m.build_number())])
                  else:
                      pin = "{0} {1}".format(sp_m.name(),
                                          apply_pin_expressions(sp_m.version(), min_pin,
                                                                  max_pin))
          else:
              pin = matching_package_keys[0][0]
      return pin
  
  
  def pin_subpackage(metadata, subpackage_name, min_pin='x.x.x.x.x.x', max_pin='x',
                     exact=False, permit_undefined_jinja=False, allow_no_other_outputs=False,
                     skip_build_id=False):
      """allow people to specify pinnings based on subpackages that are defined in the recipe.
  
      For example, given a compiler package, allow it to specify either a compatible or exact
      pinning on the runtime package that is also created by the compiler package recipe
      """
      pin = None
  
      if not hasattr(metadata, 'other_outputs'):
          if allow_no_other_outputs:
              pin = subpackage_name
          else:
              raise ValueError("Bug in conda-build: we need to have info about other outputs in "
                               "order to allow pinning to them.  It's not here.")
      else:
          # two ways to match:
          #    1. only one other output named the same as the subpackage_name from the key
          #    2. whole key matches (both subpackage name and variant)
          keys = list(metadata.other_outputs.keys())
          matching_package_keys = [k for k in keys if k[0] == subpackage_name]
          pin = pin_subpackage_against_outputs(metadata, matching_package_keys,
                                               metadata.other_outputs, min_pin, max_pin,
                                               exact, permit_undefined_jinja,
                                               skip_build_id=skip_build_id)
      if not pin:
          pin = subpackage_name
          if not permit_undefined_jinja and not allow_no_other_outputs:
              raise ValueError("Didn't find subpackage version info for '{}', which is used in a"
                               " pin_subpackage expression.  Is it actually a subpackage?  If not, "
                               "you want pin_compatible instead.".format(subpackage_name))
      return pin
  
  
  def native_compiler(language, config):
      compiler = language
  
      for platform in [config.platform, config.platform.split('-')[0]]:
          try:
              compiler = DEFAULT_COMPILERS[platform][language]
              break
          except KeyError:
              continue
      if hasattr(compiler, 'keys'):
          compiler = compiler.get(config.variant.get('python', 'nope'), 'vs2017')
      return compiler
  
  
  def compiler(language, config, permit_undefined_jinja=False):
      """Support configuration of compilers.  This is somewhat platform specific.
  
      Native compilers never list their host - it is always implied.  Generally, they are
      metapackages, pointing at a package that does specify the host.  These in turn may be
      metapackages, pointing at a package where the host is the same as the target (both being the
      native architecture).
      """
  
      compiler = native_compiler(language, config)
      version = None
      if config.variant:
          target_platform = config.variant.get('target_platform', config.subdir)
          language_compiler_key = '{}_compiler'.format(language)
          # fall back to native if language-compiler is not explicitly set in variant
          compiler = config.variant.get(language_compiler_key, compiler)
          version = config.variant.get(language_compiler_key + '_version')
      else:
          target_platform = config.subdir
  
      # support cross compilers.  A cross-compiler package will have a name such as
      #    gcc_target
      #    gcc_linux-cos6-64
      compiler = '_'.join([compiler, target_platform])
      if version:
          compiler = ' '.join((compiler, version))
          compiler = ensure_valid_spec(compiler, warn=False)
      return compiler
  
  
  def cdt(package_name, config, permit_undefined_jinja=False):
      """Support configuration of Core Dependency Trees.
      We should define CDTs in a single location. The current
      idea is to emit parts of the following to index.json (the
      bits that the solver could make use of) and parts to
      about.json (the other bits).
      "system": {
        "os": {
          "type": "windows", "linux", "bsd", "darwin",
          "os_distribution": "CentOS", "FreeBSD", "Windows", "osx",
          "os_version": "6.9", "10.12.3",
          "os_kernel_version" : "2.6.32",
          "os_libc_family": "glibc",
          "os_libc_version": "2.12",
        }
        "cpu": {
          # Whichever cpu_architecture/cpu_isa we build-out for:
          # .. armv6 is compatible with and uses all CPU features of a Raspberry PI 1
          # .. armv7a is compatible with and uses all CPU features of a Raspberry PI 2
          # .. aarch64 is compatible with and uses all CPU features of a Raspberry PI 3
          "cpu_architecture": "x86", "x86_64",
                              "armv6", "armv7a", "aarch32", "aarch64",
                              "powerpc", "powerpc64",
                              "s390", "s390x",
          "cpu_isa": "nocona", "armv8.1-a", "armv8.3-a",
          # "?" because the vfpu is specified by cpu_architecture + cpu_isa + rules.
          "vfpu": "?",
          "cpu_endianness": "BE", "LE",
        }
        "gpu ?": {
        }
        "compilerflags": {
          # When put into a CDT these should be the base defaults.
          # Package builds can and will change these frequently.
          "CPPFLAGS": "-D_FORTIFY_SOURCE=2",
          "CFLAGS": "-march=nocona -mtune=haswell -ftree-vectorize -fPIC -fstack-protector-strong -O2 -pipe",
          "CXXFLAGS": "-fvisibility-inlines-hidden -std=c++17 -fmessage-length=0 -march=nocona -mtune=haswell -ftree-vectorize -fPIC -fstack-protector-strong -O2 -pipe",
          "LDFLAGS": "-Wl,-O1,--sort-common,--as-needed,-z,relro",
          "FFLAGS": "-fopenmp",
          # These are appended to the non-DEBUG values:
          "DEBUG_CFLAGS": "-Og -g -Wall -Wextra -fcheck=all -fbacktrace -fimplicit-none -fvar-tracking-assignments",
          "DEBUG_CXXFLAGS": "-Og -g -Wall -Wextra -fcheck=all -fbacktrace -fimplicit-none -fvar-tracking-assignments",
          "DEBUG_FFLAGS": "-Og -g -Wall -Wextra -fcheck=all -fbacktrace -fimplicit-none -fvar-tracking-assignments",
        }
      }
      """  # NOQA
  
      cdt_name = 'cos6'
      arch = config.host_arch or config.arch
      if arch == 'ppc64le' or arch == 'aarch64':
          cdt_name = 'cos7'
          cdt_arch = arch
      else:
          cdt_arch = 'x86_64' if arch == '64' else 'i686'
      if config.variant:
          cdt_name = config.variant.get('cdt_name', cdt_name)
          cdt_arch = config.variant.get('cdt_arch', cdt_arch)
      if ' ' in package_name:
          name = package_name.split(' ')[0]
          ver_build = package_name.split(' ')[1:]
          result = (name + '-' + cdt_name + '-' + cdt_arch + ' ' + ' '.join(ver_build))
      else:
          result = (package_name + '-' + cdt_name + '-' + cdt_arch)
      return result
  
  
  def resolved_packages(m, env, permit_undefined_jinja=False,
                        bypass_env_check=False):
      """Returns the final list of packages that are listed in host or build.
      This include all packages (including the indirect dependencies) that will
      be installed in the host or build environment. An example usage of this
      jinja function can be::
  
          requirements:
            host:
              - curl 7.55.1
            run_constrained:
            {% for package in resolved_packages('host') %}
              - {{ package }}
            {% endfor %}
  
      which will render to::
  
          requirements:
              host:
                  - ca-certificates 2017.08.26 h1d4fec5_0
                  - curl 7.55.1 h78862de_4
                  - libgcc-ng 7.2.0 h7cc24e2_2
                  - libssh2 1.8.0 h9cfc8f7_4
                  - openssl 1.0.2n hb7f436b_0
                  - zlib 1.2.11 ha838bed_2
              run_constrained:
                  - ca-certificates 2017.08.26 h1d4fec5_0
                  - curl 7.55.1 h78862de_4
                  - libgcc-ng 7.2.0 h7cc24e2_2
                  - libssh2 1.8.0 h9cfc8f7_4
                  - openssl 1.0.2n hb7f436b_0
                  - zlib 1.2.11 ha838bed_2
      """
      if env not in ('host', 'build'):
          raise ValueError('Only host and build dependencies are supported.')
  
      package_names = []
  
      # optimization: this is slow (requires solver), so better to bypass it
      # until the finalization stage as done similarly in pin_compatible.
      if not bypass_env_check and not permit_undefined_jinja:
          package_names, _, _ = get_env_dependencies(m, env, m.config.variant)
  
      return package_names
  
  
  def context_processor(initial_metadata, recipe_dir, config, permit_undefined_jinja,
                        allow_no_other_outputs=False, bypass_env_check=False, skip_build_id=False,
                        variant=None):
      """
      Return a dictionary to use as context for jinja templates.
  
      initial_metadata: Augment the context with values from this MetaData object.
                        Used to bootstrap metadata contents via multiple parsing passes.
      """
      ctx = get_environ(m=initial_metadata, for_env=False, skip_build_id=skip_build_id,
                        escape_backslash=True, variant=variant)
      environ = dict(os.environ)
      environ.update(get_environ(m=initial_metadata, skip_build_id=skip_build_id))
  
      ctx.update(
          load_setup_py_data=partial(load_setup_py_data, m=initial_metadata, recipe_dir=recipe_dir,
                                     permit_undefined_jinja=permit_undefined_jinja),
          # maintain old alias for backwards compatibility:
          load_setuptools=partial(load_setuptools, m=initial_metadata, recipe_dir=recipe_dir,
                                  permit_undefined_jinja=permit_undefined_jinja),
          load_npm=load_npm,
          load_file_regex=partial(load_file_regex, config=config, recipe_dir=recipe_dir,
                                  permit_undefined_jinja=permit_undefined_jinja),
          installed=get_installed_packages(os.path.join(config.host_prefix, 'conda-meta')),
          pin_compatible=partial(pin_compatible, initial_metadata,
                                 permit_undefined_jinja=permit_undefined_jinja,
                                 bypass_env_check=bypass_env_check),
          pin_subpackage=partial(pin_subpackage, initial_metadata,
                                 permit_undefined_jinja=permit_undefined_jinja,
                                 allow_no_other_outputs=allow_no_other_outputs,
                                 skip_build_id=skip_build_id),
          compiler=partial(compiler, config=config, permit_undefined_jinja=permit_undefined_jinja),
          cdt=partial(cdt, config=config, permit_undefined_jinja=permit_undefined_jinja),
          resolved_packages=partial(resolved_packages, initial_metadata,
                               permit_undefined_jinja=permit_undefined_jinja,
                               bypass_env_check=bypass_env_check),
          time=time,
          datetime=datetime,
  
          environ=environ)
      return ctx
  