text: # Licensed under the Apache License: http://www.apache.org/licenses/LICENSE-2.0
  # For details: https://github.com/nedbat/coveragepy/blob/master/NOTICE.txt
  
  """Core control stuff for coverage.py."""
  
  import atexit
  import os
  import os.path
  import platform
  import sys
  import time
  
  from coverage import env
  from coverage.annotate import AnnotateReporter
  from coverage.backward import string_class, iitems
  from coverage.collector import Collector, CTracer
  from coverage.config import read_coverage_config
  from coverage.context import should_start_context_test_function
  from coverage.data import CoverageData, combine_parallel_data
  from coverage.debug import DebugControl, write_formatted_info
  from coverage.disposition import disposition_debug_msg
  from coverage.files import PathAliases, set_relative_directory, abs_file
  from coverage.html import HtmlReporter
  from coverage.inorout import InOrOut
  from coverage.misc import CoverageException, bool_or_none, join_regex
  from coverage.misc import ensure_dir_for_file, file_be_gone, isolate_module
  from coverage.plugin import FileReporter
  from coverage.plugin_support import Plugins
  from coverage.python import PythonFileReporter
  from coverage.results import Analysis, Numbers
  from coverage.summary import SummaryReporter
  from coverage.xmlreport import XmlReporter
  
  try:
      from coverage.multiproc import patch_multiprocessing
  except ImportError:                                         # pragma: only jython
      # Jython has no multiprocessing module.
      patch_multiprocessing = None
  
  os = isolate_module(os)
  
  
  class Coverage(object):
      """Programmatic access to coverage.py.
  
      To use::
  
          from coverage import Coverage
  
          cov = Coverage()
          cov.start()
          #.. call your code ..
          cov.stop()
          cov.html_report(directory='covhtml')
  
      """
  
      def __init__(
          self, data_file=None, data_suffix=None, cover_pylib=None,
          auto_data=False, timid=None, branch=None, config_file=True,
          source=None, omit=None, include=None, debug=None,
          concurrency=None, check_preimported=False, context=None,
      ):
          """
          `data_file` is the base name of the data file to use, defaulting to
          ".coverage".  `data_suffix` is appended (with a dot) to `data_file` to
          create the final file name.  If `data_suffix` is simply True, then a
          suffix is created with the machine and process identity included.
  
          `cover_pylib` is a boolean determining whether Python code installed
          with the Python interpreter is measured.  This includes the Python
          standard library and any packages installed with the interpreter.
  
          If `auto_data` is true, then any existing data file will be read when
          coverage measurement starts, and data will be saved automatically when
          measurement stops.
  
          If `timid` is true, then a slower and simpler trace function will be
          used.  This is important for some environments where manipulation of
          tracing functions breaks the faster trace function.
  
          If `branch` is true, then branch coverage will be measured in addition
          to the usual statement coverage.
  
          `config_file` determines what configuration file to read:
  
              * If it is ".coveragerc", it is interpreted as if it were True,
                for backward compatibility.
  
              * If it is a string, it is the name of the file to read.  If the
                file can't be read, it is an error.
  
              * If it is True, then a few standard files names are tried
                (".coveragerc", "setup.cfg", "tox.ini").  It is not an error for
                these files to not be found.
  
              * If it is False, then no configuration file is read.
  
          `source` is a list of file paths or package names.  Only code located
          in the trees indicated by the file paths or package names will be
          measured.
  
          `include` and `omit` are lists of file name patterns. Files that match
          `include` will be measured, files that match `omit` will not.  Each
          will also accept a single string argument.
  
          `debug` is a list of strings indicating what debugging information is
          desired.
  
          `concurrency` is a string indicating the concurrency library being used
          in the measured code.  Without this, coverage.py will get incorrect
          results if these libraries are in use.  Valid strings are "greenlet",
          "eventlet", "gevent", "multiprocessing", or "thread" (the default).
          This can also be a list of these strings.
  
          If `check_preimported` is true, then when coverage is started, the
          aleady-imported files will be checked to see if they should be measured
          by coverage.  Importing measured files before coverage is started can
          mean that code is missed.
  
          `context` is a string to use as the context label for collected data.
  
          .. versionadded:: 4.0
              The `concurrency` parameter.
  
          .. versionadded:: 4.2
              The `concurrency` parameter can now be a list of strings.
  
          .. versionadded:: 5.0
              The `check_preimported` and `context` parameters.
  
          """
          # Build our configuration from a number of sources.
          self.config = read_coverage_config(
              config_file=config_file,
              data_file=data_file, cover_pylib=cover_pylib, timid=timid,
              branch=branch, parallel=bool_or_none(data_suffix),
              source=source, run_omit=omit, run_include=include, debug=debug,
              report_omit=omit, report_include=include,
              concurrency=concurrency, context=context,
              )
  
          # This is injectable by tests.
          self._debug_file = None
  
          self._auto_load = self._auto_save = auto_data
          self._data_suffix_specified = data_suffix
  
          # Is it ok for no data to be collected?
          self._warn_no_data = True
          self._warn_unimported_source = True
          self._warn_preimported_source = check_preimported
  
          # A record of all the warnings that have been issued.
          self._warnings = []
  
          # Other instance attributes, set later.
          self._data = self._collector = None
          self._plugins = None
          self._inorout = None
          self._inorout_class = InOrOut
          self._data_suffix = self._run_suffix = None
          self._exclude_re = None
          self._debug = None
  
          # State machine variables:
          # Have we initialized everything?
          self._inited = False
          self._inited_for_start = False
          # Have we started collecting and not stopped it?
          self._started = False
          # Have we written --debug output?
          self._wrote_debug = False
  
          # If we have sub-process measurement happening automatically, then we
          # want any explicit creation of a Coverage object to mean, this process
          # is already coverage-aware, so don't auto-measure it.  By now, the
          # auto-creation of a Coverage object has already happened.  But we can
          # find it and tell it not to save its data.
          if not env.METACOV:
              _prevent_sub_process_measurement()
  
      def _init(self):
          """Set all the initial state.
  
          This is called by the public methods to initialize state. This lets us
          construct a :class:`Coverage` object, then tweak its state before this
          function is called.
  
          """
          if self._inited:
              return
  
          self._inited = True
  
          # Create and configure the debugging controller. COVERAGE_DEBUG_FILE
          # is an environment variable, the name of a file to append debug logs
          # to.
          self._debug = DebugControl(self.config.debug, self._debug_file)
  
          # _exclude_re is a dict that maps exclusion list names to compiled regexes.
          self._exclude_re = {}
  
          set_relative_directory()
  
          # Load plugins
          self._plugins = Plugins.load_plugins(self.config.plugins, self.config, self._debug)
  
          # Run configuring plugins.
          for plugin in self._plugins.configurers:
              # We need an object with set_option and get_option. Either self or
              # self.config will do. Choosing randomly stops people from doing
              # other things with those objects, against the public API.  Yes,
              # this is a bit childish. :)
              plugin.configure([self, self.config][int(time.time()) % 2])
  
      def _post_init(self):
          """Stuff to do after everything is initialized."""
          if not self._wrote_debug:
              self._wrote_debug = True
              self._write_startup_debug()
  
      def _write_startup_debug(self):
          """Write out debug info at startup if needed."""
          wrote_any = False
          with self._debug.without_callers():
              if self._debug.should('config'):
                  config_info = sorted(self.config.__dict__.items())
                  config_info = [(k, v) for k, v in config_info if not k.startswith('_')]
                  write_formatted_info(self._debug, "config", config_info)
                  wrote_any = True
  
              if self._debug.should('sys'):
                  write_formatted_info(self._debug, "sys", self.sys_info())
                  for plugin in self._plugins:
                      header = "sys: " + plugin._coverage_plugin_name
                      info = plugin.sys_info()
                      write_formatted_info(self._debug, header, info)
                  wrote_any = True
  
          if wrote_any:
              write_formatted_info(self._debug, "end", ())
  
      def _should_trace(self, filename, frame):
          """Decide whether to trace execution in `filename`.
  
          Calls `_should_trace_internal`, and returns the FileDisposition.
  
          """
          disp = self._inorout.should_trace(filename, frame)
          if self._debug.should('trace'):
              self._debug.write(disposition_debug_msg(disp))
          return disp
  
      def _check_include_omit_etc(self, filename, frame):
          """Check a file name against the include/omit/etc, rules, verbosely.
  
          Returns a boolean: True if the file should be traced, False if not.
  
          """
          reason = self._inorout.check_include_omit_etc(filename, frame)
          if self._debug.should('trace'):
              if not reason:
                  msg = "Including %r" % (filename,)
              else:
                  msg = "Not including %r: %s" % (filename, reason)
              self._debug.write(msg)
  
          return not reason
  
      def _warn(self, msg, slug=None):
          """Use `msg` as a warning.
  
          For warning suppression, use `slug` as the shorthand.
          """
          if slug in self.config.disable_warnings:
              # Don't issue the warning
              return
  
          self._warnings.append(msg)
          if slug:
              msg = "%s (%s)" % (msg, slug)
          if self._debug.should('pid'):
              msg = "[%d] %s" % (os.getpid(), msg)
          sys.stderr.write("Coverage.py warning: %s\n" % msg)
  
      def get_option(self, option_name):
          """Get an option from the configuration.
  
          `option_name` is a colon-separated string indicating the section and
          option name.  For example, the ``branch`` option in the ``[run]``
          section of the config file would be indicated with `"run:branch"`.
  
          Returns the value of the option.
  
          .. versionadded:: 4.0
  
          """
          return self.config.get_option(option_name)
  
      def set_option(self, option_name, value):
          """Set an option in the configuration.
  
          `option_name` is a colon-separated string indicating the section and
          option name.  For example, the ``branch`` option in the ``[run]``
          section of the config file would be indicated with ``"run:branch"``.
  
          `value` is the new value for the option.  This should be an
          appropriate Python value.  For example, use True for booleans, not the
          string ``"True"``.
  
          As an example, calling::
  
              cov.set_option("run:branch", True)
  
          has the same effect as this configuration file::
  
              [run]
              branch = True
  
          .. versionadded:: 4.0
  
          """
          self.config.set_option(option_name, value)
  
      def load(self):
          """Load previously-collected coverage data from the data file."""
          self._init()
          if self._collector:
              self._collector.reset()
          should_skip = self.config.parallel and not os.path.exists(self.config.data_file)
          if not should_skip:
              self._init_data(suffix=None)
          self._post_init()
          if not should_skip:
              self._data.read()
  
      def _init_for_start(self):
          """Initialization for start()"""
          # Construct the collector.
          concurrency = self.config.concurrency or []
          if "multiprocessing" in concurrency:
              if not patch_multiprocessing:
                  raise CoverageException(                    # pragma: only jython
                      "multiprocessing is not supported on this Python"
                  )
              patch_multiprocessing(rcfile=self.config.config_file)
              # Multi-processing uses parallel for the subprocesses, so also use
              # it for the main process.
              self.config.parallel = True
  
          if self.config.dynamic_context is None:
              should_start_context = None
          elif self.config.dynamic_context == "test_function":
              should_start_context = should_start_context_test_function
          else:
              raise CoverageException(
                  "Don't understand dynamic_context setting: {!r}".format(self.config.dynamic_context)
              )
  
          self._collector = Collector(
              should_trace=self._should_trace,
              check_include=self._check_include_omit_etc,
              should_start_context=should_start_context,
              timid=self.config.timid,
              branch=self.config.branch,
              warn=self._warn,
              concurrency=concurrency,
              )
  
          suffix = self._data_suffix_specified
          if suffix or self.config.parallel:
              if not isinstance(suffix, string_class):
                  # if data_suffix=True, use .machinename.pid.random
                  suffix = True
          else:
              suffix = None
  
          self._init_data(suffix)
  
          self._collector.use_data(self._data, self.config.context)
  
          # Early warning if we aren't going to be able to support plugins.
          if self._plugins.file_tracers and not self._collector.supports_plugins:
              self._warn(
                  "Plugin file tracers (%s) aren't supported with %s" % (
                      ", ".join(
                          plugin._coverage_plugin_name
                              for plugin in self._plugins.file_tracers
                          ),
                      self._collector.tracer_name(),
                      )
                  )
              for plugin in self._plugins.file_tracers:
                  plugin._coverage_enabled = False
  
          # Create the file classifying substructure.
          self._inorout = self._inorout_class(warn=self._warn)
          self._inorout.configure(self.config)
          self._inorout.plugins = self._plugins
          self._inorout.disp_class = self._collector.file_disposition_class
  
          atexit.register(self._atexit)
  
      def _init_data(self, suffix):
          """Create a data file if we don't have one yet."""
          if self._data is None:
              # Create the data file.  We do this at construction time so that the
              # data file will be written into the directory where the process
              # started rather than wherever the process eventually chdir'd to.
              ensure_dir_for_file(self.config.data_file)
              self._data = CoverageData(
                  basename=self.config.data_file,
                  suffix=suffix,
                  warn=self._warn,
                  debug=self._debug,
              )
  
      def start(self):
          """Start measuring code coverage.
  
          Coverage measurement only occurs in functions called after
          :meth:`start` is invoked.  Statements in the same scope as
          :meth:`start` won't be measured.
  
          Once you invoke :meth:`start`, you must also call :meth:`stop`
          eventually, or your process might not shut down cleanly.
  
          """
          self._init()
          if not self._inited_for_start:
              self._inited_for_start = True
              self._init_for_start()
          self._post_init()
  
          # Issue warnings for possible problems.
          self._inorout.warn_conflicting_settings()
  
          # See if we think some code that would eventually be measured has
          # already been imported.
          if self._warn_preimported_source:
              self._inorout.warn_already_imported_files()
  
          if self._auto_load:
              self.load()
  
          self._collector.start()
          self._started = True
  
      def stop(self):
          """Stop measuring code coverage."""
          if self._started:
              self._collector.stop()
          self._started = False
  
      def _atexit(self):
          """Clean up on process shutdown."""
          if self._debug.should("process"):
              self._debug.write("atexit: {0!r}".format(self))
          if self._started:
              self.stop()
          if self._auto_save:
              self.save()
  
      def erase(self):
          """Erase previously-collected coverage data.
  
          This removes the in-memory data collected in this session as well as
          discarding the data file.
  
          """
          self._init()
          self._post_init()
          if self._collector:
              self._collector.reset()
          self._init_data(suffix=None)
          self._data.erase(parallel=self.config.parallel)
          self._data = None
  
      def clear_exclude(self, which='exclude'):
          """Clear the exclude list."""
          self._init()
          setattr(self.config, which + "_list", [])
          self._exclude_regex_stale()
  
      def exclude(self, regex, which='exclude'):
          """Exclude source lines from execution consideration.
  
          A number of lists of regular expressions are maintained.  Each list
          selects lines that are treated differently during reporting.
  
          `which` determines which list is modified.  The "exclude" list selects
          lines that are not considered executable at all.  The "partial" list
          indicates lines with branches that are not taken.
  
          `regex` is a regular expression.  The regex is added to the specified
          list.  If any of the regexes in the list is found in a line, the line
          is marked for special treatment during reporting.
  
          """
          self._init()
          excl_list = getattr(self.config, which + "_list")
          excl_list.append(regex)
          self._exclude_regex_stale()
  
      def _exclude_regex_stale(self):
          """Drop all the compiled exclusion regexes, a list was modified."""
          self._exclude_re.clear()
  
      def _exclude_regex(self, which):
          """Return a compiled regex for the given exclusion list."""
          if which not in self._exclude_re:
              excl_list = getattr(self.config, which + "_list")
              self._exclude_re[which] = join_regex(excl_list)
          return self._exclude_re[which]
  
      def get_exclude_list(self, which='exclude'):
          """Return a list of excluded regex patterns.
  
          `which` indicates which list is desired.  See :meth:`exclude` for the
          lists that are available, and their meaning.
  
          """
          self._init()
          return getattr(self.config, which + "_list")
  
      def save(self):
          """Save the collected coverage data to the data file."""
          data = self.get_data()
          data.write()
  
      def combine(self, data_paths=None, strict=False):
          """Combine together a number of similarly-named coverage data files.
  
          All coverage data files whose name starts with `data_file` (from the
          coverage() constructor) will be read, and combined together into the
          current measurements.
  
          `data_paths` is a list of files or directories from which data should
          be combined. If no list is passed, then the data files from the
          directory indicated by the current data file (probably the current
          directory) will be combined.
  
          If `strict` is true, then it is an error to attempt to combine when
          there are no data files to combine.
  
          .. versionadded:: 4.0
              The `data_paths` parameter.
  
          .. versionadded:: 4.3
              The `strict` parameter.
  
          """
          self._init()
          self._init_data(suffix=None)
          self._post_init()
          self.get_data()
  
          aliases = None
          if self.config.paths:
              aliases = PathAliases()
              for paths in self.config.paths.values():
                  result = paths[0]
                  for pattern in paths[1:]:
                      aliases.add(pattern, result)
  
          combine_parallel_data(self._data, aliases=aliases, data_paths=data_paths, strict=strict)
  
      def get_data(self):
          """Get the collected data.
  
          Also warn about various problems collecting data.
  
          Returns a :class:`coverage.CoverageData`, the collected coverage data.
  
          .. versionadded:: 4.0
  
          """
          self._init()
          self._init_data(suffix=None)
          self._post_init()
  
          if self._collector and self._collector.flush_data():
              self._post_save_work()
  
          return self._data
  
      def _post_save_work(self):
          """After saving data, look for warnings, post-work, etc.
  
          Warn about things that should have happened but didn't.
          Look for unexecuted files.
  
          """
          # If there are still entries in the source_pkgs_unmatched list,
          # then we never encountered those packages.
          if self._warn_unimported_source:
              self._inorout.warn_unimported_source()
  
          # Find out if we got any data.
          if not self._data and self._warn_no_data:
              self._warn("No data was collected.", slug="no-data-collected")
  
          # Find files that were never executed at all.
          for file_path, plugin_name in self._inorout.find_unexecuted_files():
              self._data.touch_file(file_path, plugin_name)
  
          if self.config.note:
              self._data.add_run_info(note=self.config.note)
  
      # Backward compatibility with version 1.
      def analysis(self, morf):
          """Like `analysis2` but doesn't return excluded line numbers."""
          f, s, _, m, mf = self.analysis2(morf)
          return f, s, m, mf
  
      def analysis2(self, morf):
          """Analyze a module.
  
          `morf` is a module or a file name.  It will be analyzed to determine
          its coverage statistics.  The return value is a 5-tuple:
  
          * The file name for the module.
          * A list of line numbers of executable statements.
          * A list of line numbers of excluded statements.
          * A list of line numbers of statements not run (missing from
            execution).
          * A readable formatted string of the missing line numbers.
  
          The analysis uses the source file itself and the current measured
          coverage data.
  
          """
          analysis = self._analyze(morf)
          return (
              analysis.filename,
              sorted(analysis.statements),
              sorted(analysis.excluded),
              sorted(analysis.missing),
              analysis.missing_formatted(),
              )
  
      def _analyze(self, it):
          """Analyze a single morf or code unit.
  
          Returns an `Analysis` object.
  
          """
          # All reporting comes through here, so do reporting initialization.
          self._init()
          Numbers.set_precision(self.config.precision)
          self._post_init()
  
          data = self.get_data()
          if not isinstance(it, FileReporter):
              it = self._get_file_reporter(it)
  
          return Analysis(data, it)
  
      def _get_file_reporter(self, morf):
          """Get a FileReporter for a module or file name."""
          plugin = None
          file_reporter = "python"
  
          if isinstance(morf, string_class):
              abs_morf = abs_file(morf)
              plugin_name = self._data.file_tracer(abs_morf)
              if plugin_name:
                  plugin = self._plugins.get(plugin_name)
  
          if plugin:
              file_reporter = plugin.file_reporter(abs_morf)
              if file_reporter is None:
                  raise CoverageException(
                      "Plugin %r did not provide a file reporter for %r." % (
                          plugin._coverage_plugin_name, morf
                      )
                  )
  
          if file_reporter == "python":
              file_reporter = PythonFileReporter(morf, self)
  
          return file_reporter
  
      def _get_file_reporters(self, morfs=None):
          """Get a list of FileReporters for a list of modules or file names.
  
          For each module or file name in `morfs`, find a FileReporter.  Return
          the list of FileReporters.
  
          If `morfs` is a single module or file name, this returns a list of one
          FileReporter.  If `morfs` is empty or None, then the list of all files
          measured is used to find the FileReporters.
  
          """
          if not morfs:
              morfs = self._data.measured_files()
  
          # Be sure we have a collection.
          if not isinstance(morfs, (list, tuple, set)):
              morfs = [morfs]
  
          file_reporters = [self._get_file_reporter(morf) for morf in morfs]
          return file_reporters
  
      def report(
          self, morfs=None, show_missing=None, ignore_errors=None,
          file=None,                  # pylint: disable=redefined-builtin
          omit=None, include=None, skip_covered=None,
      ):
          """Write a textual summary report to `file`.
  
          Each module in `morfs` is listed, with counts of statements, executed
          statements, missing statements, and a list of lines missed.
  
          If `show_missing` is true, then details of which lines or branches are
          missing will be included in the report.  If `ignore_errors` is true,
          then a failure while reporting a single file will not stop the entire
          report.
  
          `file` is a file-like object, suitable for writing.
  
          `include` is a list of file name patterns.  Files that match will be
          included in the report. Files matching `omit` will not be included in
          the report.
  
          If `skip_covered` is true, don't report on files with 100% coverage.
  
          All of the arguments default to the settings read from the
          :ref:`configuration file <config>`.
  
          Returns a float, the total percentage covered.
  
          """
          self.config.from_args(
              ignore_errors=ignore_errors, report_omit=omit, report_include=include,
              show_missing=show_missing, skip_covered=skip_covered,
              )
          reporter = SummaryReporter(self, self.config)
          return reporter.report(morfs, outfile=file)
  
      def annotate(
          self, morfs=None, directory=None, ignore_errors=None,
          omit=None, include=None,
      ):
          """Annotate a list of modules.
  
          Each module in `morfs` is annotated.  The source is written to a new
          file, named with a ",cover" suffix, with each line prefixed with a
          marker to indicate the coverage of the line.  Covered lines have ">",
          excluded lines have "-", and missing lines have "!".
  
          See :meth:`report` for other arguments.
  
          """
          self.config.from_args(
              ignore_errors=ignore_errors, report_omit=omit, report_include=include
              )
          reporter = AnnotateReporter(self, self.config)
          reporter.report(morfs, directory=directory)
  
      def html_report(self, morfs=None, directory=None, ignore_errors=None,
                      omit=None, include=None, extra_css=None, title=None,
                      skip_covered=None):
          """Generate an HTML report.
  
          The HTML is written to `directory`.  The file "index.html" is the
          overview starting point, with links to more detailed pages for
          individual modules.
  
          `extra_css` is a path to a file of other CSS to apply on the page.
          It will be copied into the HTML directory.
  
          `title` is a text string (not HTML) to use as the title of the HTML
          report.
  
          See :meth:`report` for other arguments.
  
          Returns a float, the total percentage covered.
  
          """
          self.config.from_args(
              ignore_errors=ignore_errors, report_omit=omit, report_include=include,
              html_dir=directory, extra_css=extra_css, html_title=title,
              skip_covered=skip_covered,
              )
          reporter = HtmlReporter(self, self.config)
          return reporter.report(morfs)
  
      def xml_report(
          self, morfs=None, outfile=None, ignore_errors=None,
          omit=None, include=None,
      ):
          """Generate an XML report of coverage results.
  
          The report is compatible with Cobertura reports.
  
          Each module in `morfs` is included in the report.  `outfile` is the
          path to write the file to, "-" will write to stdout.
  
          See :meth:`report` for other arguments.
  
          Returns a float, the total percentage covered.
  
          """
          self.config.from_args(
              ignore_errors=ignore_errors, report_omit=omit, report_include=include,
              xml_output=outfile,
              )
          file_to_close = None
          delete_file = False
          if self.config.xml_output:
              if self.config.xml_output == '-':
                  outfile = sys.stdout
              else:
                  # Ensure that the output directory is created; done here
                  # because this report pre-opens the output file.
                  # HTMLReport does this using the Report plumbing because
                  # its task is more complex, being multiple files.
                  ensure_dir_for_file(self.config.xml_output)
                  open_kwargs = {}
                  if env.PY3:
                      open_kwargs['encoding'] = 'utf8'
                  outfile = open(self.config.xml_output, "w", **open_kwargs)
                  file_to_close = outfile
          try:
              reporter = XmlReporter(self, self.config)
              return reporter.report(morfs, outfile=outfile)
          except CoverageException:
              delete_file = True
              raise
          finally:
              if file_to_close:
                  file_to_close.close()
                  if delete_file:
                      file_be_gone(self.config.xml_output)
  
      def sys_info(self):
          """Return a list of (key, value) pairs showing internal information."""
  
          import coverage as covmod
  
          self._init()
          self._post_init()
  
          def plugin_info(plugins):
              """Make an entry for the sys_info from a list of plug-ins."""
              entries = []
              for plugin in plugins:
                  entry = plugin._coverage_plugin_name
                  if not plugin._coverage_enabled:
                      entry += " (disabled)"
                  entries.append(entry)
              return entries
  
          info = [
              ('version', covmod.__version__),
              ('coverage', covmod.__file__),
              ('tracer', self._collector.tracer_name() if self._collector else "-none-"),
              ('CTracer', 'available' if CTracer else "unavailable"),
              ('plugins.file_tracers', plugin_info(self._plugins.file_tracers)),
              ('plugins.configurers', plugin_info(self._plugins.configurers)),
              ('configs_attempted', self.config.attempted_config_files),
              ('configs_read', self.config.config_files_read),
              ('config_file', self.config.config_file),
              ('config_contents',
                  repr(self.config._config_contents)
                  if self.config._config_contents
                  else '-none-'
              ),
              ('data_file', self._data.filename if self._data else "-none-"),
              ('python', sys.version.replace('\n', '')),
              ('platform', platform.platform()),
              ('implementation', platform.python_implementation()),
              ('executable', sys.executable),
              ('pid', os.getpid()),
              ('cwd', os.getcwd()),
              ('path', sys.path),
              ('environment', sorted(
                  ("%s = %s" % (k, v))
                  for k, v in iitems(os.environ)
                  if any(slug in k for slug in ("COV", "PY"))
              )),
              ('command_line', " ".join(getattr(sys, 'argv', ['-none-']))),
              ]
  
          if self._inorout:
              info.extend(self._inorout.sys_info())
  
          return info
  
  
  # Mega debugging...
  if int(os.environ.get("COVERAGE_DEBUG_CALLS", 0)):              # pragma: debugging
      from coverage.debug import decorate_methods, show_calls
  
      Coverage = decorate_methods(show_calls(show_args=True), butnot=['get_data'])(Coverage)
  
  
  def process_startup():
      """Call this at Python start-up to perhaps measure coverage.
  
      If the environment variable COVERAGE_PROCESS_START is defined, coverage
      measurement is started.  The value of the variable is the config file
      to use.
  
      There are two ways to configure your Python installation to invoke this
      function when Python starts:
  
      #. Create or append to sitecustomize.py to add these lines::
  
          import coverage
          coverage.process_startup()
  
      #. Create a .pth file in your Python installation containing::
  
          import coverage; coverage.process_startup()
  
      Returns the :class:`Coverage` instance that was started, or None if it was
      not started by this call.
  
      """
      cps = os.environ.get("COVERAGE_PROCESS_START")
      if not cps:
          # No request for coverage, nothing to do.
          return None
  
      # This function can be called more than once in a process. This happens
      # because some virtualenv configurations make the same directory visible
      # twice in sys.path.  This means that the .pth file will be found twice,
      # and executed twice, executing this function twice.  We set a global
      # flag (an attribute on this function) to indicate that coverage.py has
      # already been started, so we can avoid doing it twice.
      #
      # https://bitbucket.org/ned/coveragepy/issue/340/keyerror-subpy has more
      # details.
  
      if hasattr(process_startup, "coverage"):
          # We've annotated this function before, so we must have already
          # started coverage.py in this process.  Nothing to do.
          return None
  
      cov = Coverage(config_file=cps)
      process_startup.coverage = cov
      cov._warn_no_data = False
      cov._warn_unimported_source = False
      cov._warn_preimported_source = False
      cov._auto_save = True
      cov.start()
  
      return cov
  
  
  def _prevent_sub_process_measurement():
      """Stop any subprocess auto-measurement from writing data."""
      auto_created_coverage = getattr(process_startup, "coverage", None)
      if auto_created_coverage is not None:
          auto_created_coverage._auto_save = False
  