Documentation/sphinx/kernel_include.py

0001 #!/usr/bin/env python3
0002 # -*- coding: utf-8; mode: python -*-
0003 # pylint: disable=R0903, C0330, R0914, R0912, E0401
0004
0005 u"""
0006     kernel-include
0007     ~~~~~~~~~~~~~~
0008
0009     Implementation of the ``kernel-include`` reST-directive.
0010
0011     :copyright:  Copyright (C) 2016  Markus Heiser
0012     :license:    GPL Version 2, June 1991 see linux/COPYING for details.
0013
0014     The ``kernel-include`` reST-directive is a replacement for the ``include``
0015     directive. The ``kernel-include`` directive expand environment variables in
0016     the path name and allows to include files from arbitrary locations.
0017
0018     .. hint::
0019
0020       Including files from arbitrary locations (e.g. from ``/etc``) is a
0021       security risk for builders. This is why the ``include`` directive from
0022       docutils *prohibit* pathnames pointing to locations *above* the filesystem
0023       tree where the reST document with the include directive is placed.
0024
0025     Substrings of the form $name or ${name} are replaced by the value of
0026     environment variable name. Malformed variable names and references to
0027     non-existing variables are left unchanged.
0028 """
0029
0030 # ==============================================================================
0031 # imports
0032 # ==============================================================================
0033
0034 import os.path
0035
0036 from docutils import io, nodes, statemachine
0037 from docutils.utils.error_reporting import SafeString, ErrorString
0038 from docutils.parsers.rst import directives
0039 from docutils.parsers.rst.directives.body import CodeBlock, NumberLines
0040 from docutils.parsers.rst.directives.misc import Include
0041
0042 __version__  = '1.0'
0043
0044 # ==============================================================================
0045 def setup(app):
0046 # ==============================================================================
0047
0048     app.add_directive("kernel-include", KernelInclude)
0049     return dict(
0050         version = __version__,
0051         parallel_read_safe = True,
0052         parallel_write_safe = True
0053     )
0054
0055 # ==============================================================================
0056 class KernelInclude(Include):
0057 # ==============================================================================
0058
0059     u"""KernelInclude (``kernel-include``) directive"""
0060
0061     def run(self):
0062         env = self.state.document.settings.env
0063         path = os.path.realpath(
0064             os.path.expandvars(self.arguments[0]))
0065
0066         # to get a bit security back, prohibit /etc:
0067         if path.startswith(os.sep + "etc"):
0068             raise self.severe(
0069                 'Problems with "%s" directive, prohibited path: %s'
0070                 % (self.name, path))
0071
0072         self.arguments[0] = path
0073
0074         env.note_dependency(os.path.abspath(path))
0075
0076         #return super(KernelInclude, self).run() # won't work, see HINTs in _run()
0077         return self._run()
0078
0079     def _run(self):
0080         """Include a file as part of the content of this reST file."""
0081
0082         # HINT: I had to copy&paste the whole Include.run method. I'am not happy
0083         # with this, but due to security reasons, the Include.run method does
0084         # not allow absolute or relative pathnames pointing to locations *above*
0085         # the filesystem tree where the reST document is placed.
0086
0087         if not self.state.document.settings.file_insertion_enabled:
0088             raise self.warning('"%s" directive disabled.' % self.name)
0089         source = self.state_machine.input_lines.source(
0090             self.lineno - self.state_machine.input_offset - 1)
0091         source_dir = os.path.dirname(os.path.abspath(source))
0092         path = directives.path(self.arguments[0])
0093         if path.startswith('<') and path.endswith('>'):
0094             path = os.path.join(self.standard_include_path, path[1:-1])
0095         path = os.path.normpath(os.path.join(source_dir, path))
0096
0097         # HINT: this is the only line I had to change / commented out:
0098         #path = utils.relative_path(None, path)
0099
0100         path = nodes.reprunicode(path)
0101         encoding = self.options.get(
0102             'encoding', self.state.document.settings.input_encoding)
0103         e_handler=self.state.document.settings.input_encoding_error_handler
0104         tab_width = self.options.get(
0105             'tab-width', self.state.document.settings.tab_width)
0106         try:
0107             self.state.document.settings.record_dependencies.add(path)
0108             include_file = io.FileInput(source_path=path,
0109                                         encoding=encoding,
0110                                         error_handler=e_handler)
0111         except UnicodeEncodeError as error:
0112             raise self.severe('Problems with "%s" directive path:\n'
0113                               'Cannot encode input file path "%s" '
0114                               '(wrong locale?).' %
0115                               (self.name, SafeString(path)))
0116         except IOError as error:
0117             raise self.severe('Problems with "%s" directive path:\n%s.' %
0118                       (self.name, ErrorString(error)))
0119         startline = self.options.get('start-line', None)
0120         endline = self.options.get('end-line', None)
0121         try:
0122             if startline or (endline is not None):
0123                 lines = include_file.readlines()
0124                 rawtext = ''.join(lines[startline:endline])
0125             else:
0126                 rawtext = include_file.read()
0127         except UnicodeError as error:
0128             raise self.severe('Problem with "%s" directive:\n%s' %
0129                               (self.name, ErrorString(error)))
0130         # start-after/end-before: no restrictions on newlines in match-text,
0131         # and no restrictions on matching inside lines vs. line boundaries
0132         after_text = self.options.get('start-after', None)
0133         if after_text:
0134             # skip content in rawtext before *and incl.* a matching text
0135             after_index = rawtext.find(after_text)
0136             if after_index < 0:
0137                 raise self.severe('Problem with "start-after" option of "%s" '
0138                                   'directive:\nText not found.' % self.name)
0139             rawtext = rawtext[after_index + len(after_text):]
0140         before_text = self.options.get('end-before', None)
0141         if before_text:
0142             # skip content in rawtext after *and incl.* a matching text
0143             before_index = rawtext.find(before_text)
0144             if before_index < 0:
0145                 raise self.severe('Problem with "end-before" option of "%s" '
0146                                   'directive:\nText not found.' % self.name)
0147             rawtext = rawtext[:before_index]
0148
0149         include_lines = statemachine.string2lines(rawtext, tab_width,
0150                                                   convert_whitespace=True)
0151         if 'literal' in self.options:
0152             # Convert tabs to spaces, if `tab_width` is positive.
0153             if tab_width >= 0:
0154                 text = rawtext.expandtabs(tab_width)
0155             else:
0156                 text = rawtext
0157             literal_block = nodes.literal_block(rawtext, source=path,
0158                                     classes=self.options.get('class', []))
0159             literal_block.line = 1
0160             self.add_name(literal_block)
0161             if 'number-lines' in self.options:
0162                 try:
0163                     startline = int(self.options['number-lines'] or 1)
0164                 except ValueError:
0165                     raise self.error(':number-lines: with non-integer '
0166                                      'start value')
0167                 endline = startline + len(include_lines)
0168                 if text.endswith('\n'):
0169                     text = text[:-1]
0170                 tokens = NumberLines([([], text)], startline, endline)
0171                 for classes, value in tokens:
0172                     if classes:
0173                         literal_block += nodes.inline(value, value,
0174                                                       classes=classes)
0175                     else:
0176                         literal_block += nodes.Text(value, value)
0177             else:
0178                 literal_block += nodes.Text(text, text)
0179             return [literal_block]
0180         if 'code' in self.options:
0181             self.options['source'] = path
0182             codeblock = CodeBlock(self.name,
0183                                   [self.options.pop('code')], # arguments
0184                                   self.options,
0185                                   include_lines, # content
0186                                   self.lineno,
0187                                   self.content_offset,
0188                                   self.block_text,
0189                                   self.state,
0190                                   self.state_machine)
0191             return codeblock.run()
0192         self.state_machine.insert_input(include_lines, path)
0193         return []