1# -*- coding: utf-8; mode: python -*-
2# pylint: disable=W0141,C0113,C0103,C0325
3u"""
4    cdomain
5    ~~~~~~~
6
7    Replacement for the sphinx c-domain.
8
9    :copyright:  Copyright (C) 2016  Markus Heiser
10    :license:    GPL Version 2, June 1991 see Linux/COPYING for details.
11
12    List of customizations:
13
14    * Moved the *duplicate C object description* warnings for function
15      declarations in the nitpicky mode. See Sphinx documentation for
16      the config values for ``nitpick`` and ``nitpick_ignore``.
17
18    * Add option 'name' to the "c:function:" directive.  With option 'name' the
19      ref-name of a function can be modified. E.g.::
20
21          .. c:function:: int ioctl( int fd, int request )
22             :name: VIDIOC_LOG_STATUS
23
24      The func-name (e.g. ioctl) remains in the output but the ref-name changed
25      from 'ioctl' to 'VIDIOC_LOG_STATUS'. The function is referenced by::
26
27          * :c:func:`VIDIOC_LOG_STATUS` or
28          * :any:`VIDIOC_LOG_STATUS` (``:any:`` needs sphinx 1.3)
29
30     * Handle signatures of function-like macros well. Don't try to deduce
31       arguments types of function-like macros.
32
33"""
34
35from docutils import nodes
36from docutils.parsers.rst import directives
37
38import sphinx
39from sphinx import addnodes
40from sphinx.domains.c import c_funcptr_sig_re, c_sig_re
41from sphinx.domains.c import CObject as Base_CObject
42from sphinx.domains.c import CDomain as Base_CDomain
43from itertools import chain
44import re
45
46__version__  = '1.1'
47
48# Get Sphinx version
49major, minor, patch = sphinx.version_info[:3]
50
51# Namespace to be prepended to the full name
52namespace = None
53
54#
55# Handle trivial newer c domain tags that are part of Sphinx 3.1 c domain tags
56# - Store the namespace if ".. c:namespace::" tag is found
57#
58RE_namespace = re.compile(r'^\s*..\s*c:namespace::\s*(\S+)\s*$')
59
60def markup_namespace(match):
61    global namespace
62
63    namespace = match.group(1)
64
65    return ""
66
67#
68# Handle c:macro for function-style declaration
69#
70RE_macro = re.compile(r'^\s*..\s*c:macro::\s*(\S+)\s+(\S.*)\s*$')
71def markup_macro(match):
72    return ".. c:function:: " + match.group(1) + ' ' + match.group(2)
73
74#
75# Handle newer c domain tags that are evaluated as .. c:type: for
76# backward-compatibility with Sphinx < 3.0
77#
78RE_ctype = re.compile(r'^\s*..\s*c:(struct|union|enum|enumerator|alias)::\s*(.*)$')
79
80def markup_ctype(match):
81    return ".. c:type:: " + match.group(2)
82
83#
84# Handle newer c domain tags that are evaluated as :c:type: for
85# backward-compatibility with Sphinx < 3.0
86#
87RE_ctype_refs = re.compile(r':c:(var|struct|union|enum|enumerator)::`([^\`]+)`')
88def markup_ctype_refs(match):
89    return ":c:type:`" + match.group(2) + '`'
90
91#
92# Simply convert :c:expr: and :c:texpr: into a literal block.
93#
94RE_expr = re.compile(r':c:(expr|texpr):`([^\`]+)`')
95def markup_c_expr(match):
96    return '\\ ``' + match.group(2) + '``\\ '
97
98#
99# Parse Sphinx 3.x C markups, replacing them by backward-compatible ones
100#
101def c_markups(app, docname, source):
102    result = ""
103    markup_func = {
104        RE_namespace: markup_namespace,
105        RE_expr: markup_c_expr,
106        RE_macro: markup_macro,
107        RE_ctype: markup_ctype,
108        RE_ctype_refs: markup_ctype_refs,
109    }
110
111    lines = iter(source[0].splitlines(True))
112    for n in lines:
113        match_iterators = [regex.finditer(n) for regex in markup_func]
114        matches = sorted(chain(*match_iterators), key=lambda m: m.start())
115        for m in matches:
116            n = n[:m.start()] + markup_func[m.re](m) + n[m.end():]
117
118        result = result + n
119
120    source[0] = result
121
122#
123# Now implements support for the cdomain namespacing logic
124#
125
126def setup(app):
127
128    # Handle easy Sphinx 3.1+ simple new tags: :c:expr and .. c:namespace::
129    app.connect('source-read', c_markups)
130
131    if (major == 1 and minor < 8):
132        app.override_domain(CDomain)
133    else:
134        app.add_domain(CDomain, override=True)
135
136    return dict(
137        version = __version__,
138        parallel_read_safe = True,
139        parallel_write_safe = True
140    )
141
142class CObject(Base_CObject):
143
144    """
145    Description of a C language object.
146    """
147    option_spec = {
148        "name" : directives.unchanged
149    }
150
151    def handle_func_like_macro(self, sig, signode):
152        u"""Handles signatures of function-like macros.
153
154        If the objtype is 'function' and the the signature ``sig`` is a
155        function-like macro, the name of the macro is returned. Otherwise
156        ``False`` is returned.  """
157
158        global namespace
159
160        if not self.objtype == 'function':
161            return False
162
163        m = c_funcptr_sig_re.match(sig)
164        if m is None:
165            m = c_sig_re.match(sig)
166            if m is None:
167                raise ValueError('no match')
168
169        rettype, fullname, arglist, _const = m.groups()
170        arglist = arglist.strip()
171        if rettype or not arglist:
172            return False
173
174        arglist = arglist.replace('`', '').replace('\\ ', '') # remove markup
175        arglist = [a.strip() for a in arglist.split(",")]
176
177        # has the first argument a type?
178        if len(arglist[0].split(" ")) > 1:
179            return False
180
181        # This is a function-like macro, its arguments are typeless!
182        signode  += addnodes.desc_name(fullname, fullname)
183        paramlist = addnodes.desc_parameterlist()
184        signode  += paramlist
185
186        for argname in arglist:
187            param = addnodes.desc_parameter('', '', noemph=True)
188            # separate by non-breaking space in the output
189            param += nodes.emphasis(argname, argname)
190            paramlist += param
191
192        if namespace:
193            fullname = namespace + "." + fullname
194
195        return fullname
196
197    def handle_signature(self, sig, signode):
198        """Transform a C signature into RST nodes."""
199
200        global namespace
201
202        fullname = self.handle_func_like_macro(sig, signode)
203        if not fullname:
204            fullname = super(CObject, self).handle_signature(sig, signode)
205
206        if "name" in self.options:
207            if self.objtype == 'function':
208                fullname = self.options["name"]
209            else:
210                # FIXME: handle :name: value of other declaration types?
211                pass
212        else:
213            if namespace:
214                fullname = namespace + "." + fullname
215
216        return fullname
217
218    def add_target_and_index(self, name, sig, signode):
219        # for C API items we add a prefix since names are usually not qualified
220        # by a module name and so easily clash with e.g. section titles
221        targetname = 'c.' + name
222        if targetname not in self.state.document.ids:
223            signode['names'].append(targetname)
224            signode['ids'].append(targetname)
225            signode['first'] = (not self.names)
226            self.state.document.note_explicit_target(signode)
227            inv = self.env.domaindata['c']['objects']
228            if (name in inv and self.env.config.nitpicky):
229                if self.objtype == 'function':
230                    if ('c:func', name) not in self.env.config.nitpick_ignore:
231                        self.state_machine.reporter.warning(
232                            'duplicate C object description of %s, ' % name +
233                            'other instance in ' + self.env.doc2path(inv[name][0]),
234                            line=self.lineno)
235            inv[name] = (self.env.docname, self.objtype)
236
237        indextext = self.get_index_text(name)
238        if indextext:
239            self.indexnode['entries'].append(
240                    ('single', indextext, targetname, '', None))
241
242class CDomain(Base_CDomain):
243
244    """C language domain."""
245    name = 'c'
246    label = 'C'
247    directives = {
248        'function': CObject,
249        'member':   CObject,
250        'macro':    CObject,
251        'type':     CObject,
252        'var':      CObject,
253    }
254