1#!/usr/bin/env python
2# A tool to parse ASTMatchers.h and update the documentation in
3# ../LibASTMatchersReference.html automatically. Run from the
4# directory in which this file is located to update the docs.
5
6import collections
7import re
8try:
9    from urllib.request import urlopen
10except ImportError:
11    from urllib2 import urlopen
12
13MATCHERS_FILE = '../../include/clang/ASTMatchers/ASTMatchers.h'
14
15# Each matcher is documented in one row of the form:
16#   result | name | argA
17# The subsequent row contains the documentation and is hidden by default,
18# becoming visible via javascript when the user clicks the matcher name.
19TD_TEMPLATE="""
20<tr><td>%(result)s</td><td class="name" onclick="toggle('%(id)s')"><a name="%(id)sAnchor">%(name)s</a></td><td>%(args)s</td></tr>
21<tr><td colspan="4" class="doc" id="%(id)s"><pre>%(comment)s</pre></td></tr>
22"""
23
24# We categorize the matchers into these three categories in the reference:
25node_matchers = {}
26narrowing_matchers = {}
27traversal_matchers = {}
28
29# We output multiple rows per matcher if the matcher can be used on multiple
30# node types. Thus, we need a new id per row to control the documentation
31# pop-up. ids[name] keeps track of those ids.
32ids = collections.defaultdict(int)
33
34# Cache for doxygen urls we have already verified.
35doxygen_probes = {}
36
37def esc(text):
38  """Escape any html in the given text."""
39  text = re.sub(r'&', '&amp;', text)
40  text = re.sub(r'<', '&lt;', text)
41  text = re.sub(r'>', '&gt;', text)
42  def link_if_exists(m):
43    name = m.group(1)
44    url = 'https://clang.llvm.org/doxygen/classclang_1_1%s.html' % name
45    if url not in doxygen_probes:
46      try:
47        print('Probing %s...' % url)
48        urlopen(url)
49        doxygen_probes[url] = True
50      except:
51        doxygen_probes[url] = False
52    if doxygen_probes[url]:
53      return r'Matcher&lt;<a href="%s">%s</a>&gt;' % (url, name)
54    else:
55      return m.group(0)
56  text = re.sub(
57    r'Matcher&lt;([^\*&]+)&gt;', link_if_exists, text)
58  return text
59
60def extract_result_types(comment):
61  """Extracts a list of result types from the given comment.
62
63     We allow annotations in the comment of the matcher to specify what
64     nodes a matcher can match on. Those comments have the form:
65       Usable as: Any Matcher | (Matcher<T1>[, Matcher<t2>[, ...]])
66
67     Returns ['*'] in case of 'Any Matcher', or ['T1', 'T2', ...].
68     Returns the empty list if no 'Usable as' specification could be
69     parsed.
70  """
71  result_types = []
72  m = re.search(r'Usable as: Any Matcher[\s\n]*$', comment, re.S)
73  if m:
74    return ['*']
75  while True:
76    m = re.match(r'^(.*)Matcher<([^>]+)>\s*,?[\s\n]*$', comment, re.S)
77    if not m:
78      if re.search(r'Usable as:\s*$', comment):
79        return result_types
80      else:
81        return None
82    result_types += [m.group(2)]
83    comment = m.group(1)
84
85def strip_doxygen(comment):
86  """Returns the given comment without \-escaped words."""
87  # If there is only a doxygen keyword in the line, delete the whole line.
88  comment = re.sub(r'^\\[^\s]+\n', r'', comment, flags=re.M)
89
90  # If there is a doxygen \see command, change the \see prefix into "See also:".
91  # FIXME: it would be better to turn this into a link to the target instead.
92  comment = re.sub(r'\\see', r'See also:', comment)
93
94  # Delete the doxygen command and the following whitespace.
95  comment = re.sub(r'\\[^\s]+\s+', r'', comment)
96  return comment
97
98def unify_arguments(args):
99  """Gets rid of anything the user doesn't care about in the argument list."""
100  args = re.sub(r'internal::', r'', args)
101  args = re.sub(r'extern const\s+(.*)&', r'\1 ', args)
102  args = re.sub(r'&', r' ', args)
103  args = re.sub(r'(^|\s)M\d?(\s)', r'\1Matcher<*>\2', args)
104  args = re.sub(r'BindableMatcher', r'Matcher', args)
105  args = re.sub(r'const Matcher', r'Matcher', args)
106  return args
107
108def unify_type(result_type):
109  """Gets rid of anything the user doesn't care about in the type name."""
110  result_type = re.sub(r'^internal::(Bindable)?Matcher<([a-zA-Z_][a-zA-Z0-9_]*)>$', r'\2', result_type)
111  return result_type
112
113def add_matcher(result_type, name, args, comment, is_dyncast=False):
114  """Adds a matcher to one of our categories."""
115  if name == 'id':
116     # FIXME: Figure out whether we want to support the 'id' matcher.
117     return
118  matcher_id = '%s%d' % (name, ids[name])
119  ids[name] += 1
120  args = unify_arguments(args)
121  result_type = unify_type(result_type)
122
123  docs_result_type = esc('Matcher<%s>' % result_type);
124
125  if name == 'mapAnyOf':
126    args = "nodeMatcherFunction..."
127    docs_result_type = "<em>unspecified</em>"
128
129  matcher_html = TD_TEMPLATE % {
130    'result': docs_result_type,
131    'name': name,
132    'args': esc(args),
133    'comment': esc(strip_doxygen(comment)),
134    'id': matcher_id,
135  }
136  if is_dyncast:
137    dict = node_matchers
138    lookup = result_type + name
139  # Use a heuristic to figure out whether a matcher is a narrowing or
140  # traversal matcher. By default, matchers that take other matchers as
141  # arguments (and are not node matchers) do traversal. We specifically
142  # exclude known narrowing matchers that also take other matchers as
143  # arguments.
144  elif ('Matcher<' not in args or
145        name in ['allOf', 'anyOf', 'anything', 'unless', 'mapAnyOf']):
146    dict = narrowing_matchers
147    lookup = result_type + name + esc(args)
148  else:
149    dict = traversal_matchers
150    lookup = result_type + name + esc(args)
151
152  if dict.get(lookup) is None or len(dict.get(lookup)) < len(matcher_html):
153    dict[lookup] = matcher_html
154
155def act_on_decl(declaration, comment, allowed_types):
156  """Parse the matcher out of the given declaration and comment.
157
158     If 'allowed_types' is set, it contains a list of node types the matcher
159     can match on, as extracted from the static type asserts in the matcher
160     definition.
161  """
162  if declaration.strip():
163
164    if re.match(r'^\s?(#|namespace|using)', declaration): return
165
166    # Node matchers are defined by writing:
167    #   VariadicDynCastAllOfMatcher<ResultType, ArgumentType> name;
168    m = re.match(r""".*Variadic(?:DynCast)?AllOfMatcher\s*<
169                       \s*([^\s,]+)\s*(?:,
170                       \s*([^\s>]+)\s*)?>
171                       \s*([^\s;]+)\s*;\s*$""", declaration, flags=re.X)
172    if m:
173      result, inner, name = m.groups()
174      if not inner:
175        inner = result
176      add_matcher(result, name, 'Matcher<%s>...' % inner,
177                  comment, is_dyncast=True)
178      return
179
180    # Special case of type matchers:
181    #   AstTypeMatcher<ArgumentType> name
182    m = re.match(r""".*AstTypeMatcher\s*<
183                       \s*([^\s>]+)\s*>
184                       \s*([^\s;]+)\s*;\s*$""", declaration, flags=re.X)
185    if m:
186      inner, name = m.groups()
187      add_matcher('Type', name, 'Matcher<%s>...' % inner,
188                  comment, is_dyncast=True)
189      # FIXME: re-enable once we have implemented casting on the TypeLoc
190      # hierarchy.
191      # add_matcher('TypeLoc', '%sLoc' % name, 'Matcher<%sLoc>...' % inner,
192      #             comment, is_dyncast=True)
193      return
194
195    # Parse the various matcher definition macros.
196    m = re.match(""".*AST_TYPE(LOC)?_TRAVERSE_MATCHER(?:_DECL)?\(
197                       \s*([^\s,]+\s*),
198                       \s*(?:[^\s,]+\s*),
199                       \s*AST_POLYMORPHIC_SUPPORTED_TYPES\(([^)]*)\)
200                     \)\s*;\s*$""", declaration, flags=re.X)
201    if m:
202      loc, name, results = m.groups()[0:3]
203      result_types = [r.strip() for r in results.split(',')]
204
205      comment_result_types = extract_result_types(comment)
206      if (comment_result_types and
207          sorted(result_types) != sorted(comment_result_types)):
208        raise Exception('Inconsistent documentation for: %s' % name)
209      for result_type in result_types:
210        add_matcher(result_type, name, 'Matcher<Type>', comment)
211        # if loc:
212        #   add_matcher('%sLoc' % result_type, '%sLoc' % name, 'Matcher<TypeLoc>',
213        #               comment)
214      return
215
216    m = re.match(r"""^\s*AST_POLYMORPHIC_MATCHER(_P)?(.?)(?:_OVERLOAD)?\(
217                          \s*([^\s,]+)\s*,
218                          \s*AST_POLYMORPHIC_SUPPORTED_TYPES\(([^)]*)\)
219                       (?:,\s*([^\s,]+)\s*
220                          ,\s*([^\s,]+)\s*)?
221                       (?:,\s*([^\s,]+)\s*
222                          ,\s*([^\s,]+)\s*)?
223                       (?:,\s*\d+\s*)?
224                      \)\s*{\s*$""", declaration, flags=re.X)
225
226    if m:
227      p, n, name, results = m.groups()[0:4]
228      args = m.groups()[4:]
229      result_types = [r.strip() for r in results.split(',')]
230      if allowed_types and allowed_types != result_types:
231        raise Exception('Inconsistent documentation for: %s' % name)
232      if n not in ['', '2']:
233        raise Exception('Cannot parse "%s"' % declaration)
234      args = ', '.join('%s %s' % (args[i], args[i+1])
235                       for i in range(0, len(args), 2) if args[i])
236      for result_type in result_types:
237        add_matcher(result_type, name, args, comment)
238      return
239
240    m = re.match(r"""^\s*AST_POLYMORPHIC_MATCHER_REGEX(?:_OVERLOAD)?\(
241                          \s*([^\s,]+)\s*,
242                          \s*AST_POLYMORPHIC_SUPPORTED_TYPES\(([^)]*)\),
243                          \s*([^\s,]+)\s*
244                       (?:,\s*\d+\s*)?
245                      \)\s*{\s*$""", declaration, flags=re.X)
246
247    if m:
248      name, results, arg_name = m.groups()[0:3]
249      result_types = [r.strip() for r in results.split(',')]
250      if allowed_types and allowed_types != result_types:
251        raise Exception('Inconsistent documentation for: %s' % name)
252      arg = "StringRef %s, Regex::RegexFlags Flags = NoFlags" % arg_name
253      comment += """
254If the matcher is used in clang-query, RegexFlags parameter
255should be passed as a quoted string. e.g: "NoFlags".
256Flags can be combined with '|' example \"IgnoreCase | BasicRegex\"
257"""
258      for result_type in result_types:
259        add_matcher(result_type, name, arg, comment)
260      return
261
262    m = re.match(r"""^\s*AST_MATCHER_FUNCTION(_P)?(.?)(?:_OVERLOAD)?\(
263                       (?:\s*([^\s,]+)\s*,)?
264                          \s*([^\s,]+)\s*
265                       (?:,\s*([^\s,]+)\s*
266                          ,\s*([^\s,]+)\s*)?
267                       (?:,\s*([^\s,]+)\s*
268                          ,\s*([^\s,]+)\s*)?
269                       (?:,\s*\d+\s*)?
270                      \)\s*{\s*$""", declaration, flags=re.X)
271    if m:
272      p, n, result, name = m.groups()[0:4]
273      args = m.groups()[4:]
274      if n not in ['', '2']:
275        raise Exception('Cannot parse "%s"' % declaration)
276      args = ', '.join('%s %s' % (args[i], args[i+1])
277                       for i in range(0, len(args), 2) if args[i])
278      add_matcher(result, name, args, comment)
279      return
280
281    m = re.match(r"""^\s*AST_MATCHER(_P)?(.?)(?:_OVERLOAD)?\(
282                       (?:\s*([^\s,]+)\s*,)?
283                          \s*([^\s,]+)\s*
284                       (?:,\s*([^,]+)\s*
285                          ,\s*([^\s,]+)\s*)?
286                       (?:,\s*([^\s,]+)\s*
287                          ,\s*([^\s,]+)\s*)?
288                       (?:,\s*\d+\s*)?
289                      \)\s*{""", declaration, flags=re.X)
290    if m:
291      p, n, result, name = m.groups()[0:4]
292      args = m.groups()[4:]
293      if not result:
294        if not allowed_types:
295          raise Exception('Did not find allowed result types for: %s' % name)
296        result_types = allowed_types
297      else:
298        result_types = [result]
299      if n not in ['', '2']:
300        raise Exception('Cannot parse "%s"' % declaration)
301      args = ', '.join('%s %s' % (args[i], args[i+1])
302                       for i in range(0, len(args), 2) if args[i])
303      for result_type in result_types:
304        add_matcher(result_type, name, args, comment)
305      return
306
307    m = re.match(r"""^\s*AST_MATCHER_REGEX(?:_OVERLOAD)?\(
308                       \s*([^\s,]+)\s*,
309                       \s*([^\s,]+)\s*,
310                       \s*([^\s,]+)\s*
311                       (?:,\s*\d+\s*)?
312                      \)\s*{""", declaration, flags=re.X)
313    if m:
314      result, name, arg_name = m.groups()[0:3]
315      if not result:
316        if not allowed_types:
317          raise Exception('Did not find allowed result types for: %s' % name)
318        result_types = allowed_types
319      else:
320        result_types = [result]
321      arg = "StringRef %s, Regex::RegexFlags Flags = NoFlags" % arg_name
322      comment += """
323If the matcher is used in clang-query, RegexFlags parameter
324should be passed as a quoted string. e.g: "NoFlags".
325Flags can be combined with '|' example \"IgnoreCase | BasicRegex\"
326"""
327
328      for result_type in result_types:
329        add_matcher(result_type, name, arg, comment)
330      return
331
332    # Parse ArgumentAdapting matchers.
333    m = re.match(
334        r"""^.*ArgumentAdaptingMatcherFunc<.*>\s*
335              ([a-zA-Z]*);$""",
336        declaration, flags=re.X)
337    if m:
338      name = m.groups()[0]
339      add_matcher('*', name, 'Matcher<*>', comment)
340      return
341
342    # Parse Variadic functions.
343    m = re.match(
344        r"""^.*internal::VariadicFunction\s*<\s*([^,]+),\s*([^,]+),\s*[^>]+>\s*
345              ([a-zA-Z]*);$""",
346        declaration, flags=re.X)
347    if m:
348      result, arg, name = m.groups()[:3]
349      add_matcher(result, name, '%s, ..., %s' % (arg, arg), comment)
350      return
351
352    m = re.match(
353        r"""^.*internal::VariadicFunction\s*<\s*
354              internal::PolymorphicMatcher<[\S\s]+
355              AST_POLYMORPHIC_SUPPORTED_TYPES\(([^)]*)\),\s*(.*);$""",
356        declaration, flags=re.X)
357
358    if m:
359      results, trailing = m.groups()
360      trailing, name = trailing.rsplit(">", 1)
361      name = name.strip()
362      trailing, _ = trailing.rsplit(",", 1)
363      _, arg = trailing.rsplit(",", 1)
364      arg = arg.strip()
365
366      result_types = [r.strip() for r in results.split(',')]
367      for result_type in result_types:
368        add_matcher(result_type, name, '%s, ..., %s' % (arg, arg), comment)
369      return
370
371
372    # Parse Variadic operator matchers.
373    m = re.match(
374        r"""^.*VariadicOperatorMatcherFunc\s*<\s*([^,]+),\s*([^\s]+)\s*>\s*
375              ([a-zA-Z]*);$""",
376        declaration, flags=re.X)
377    if m:
378      min_args, max_args, name = m.groups()[:3]
379      if max_args == '1':
380        add_matcher('*', name, 'Matcher<*>', comment)
381        return
382      elif max_args == 'std::numeric_limits<unsigned>::max()':
383        add_matcher('*', name, 'Matcher<*>, ..., Matcher<*>', comment)
384        return
385
386    m = re.match(
387        r"""^.*MapAnyOfMatcher<.*>\s*
388              ([a-zA-Z]*);$""",
389        declaration, flags=re.X)
390    if m:
391      name = m.groups()[0]
392      add_matcher('*', name, 'Matcher<*>...Matcher<*>', comment)
393      return
394
395    # Parse free standing matcher functions, like:
396    #   Matcher<ResultType> Name(Matcher<ArgumentType> InnerMatcher) {
397    m = re.match(r"""^\s*(?:template\s+<\s*(?:class|typename)\s+(.+)\s*>\s+)?
398                     (.*)\s+
399                     ([^\s\(]+)\s*\(
400                     (.*)
401                     \)\s*{""", declaration, re.X)
402    if m:
403      template_name, result, name, args = m.groups()
404      if template_name:
405        matcherTemplateArgs = re.findall(r'Matcher<\s*(%s)\s*>' % template_name, args)
406        templateArgs = re.findall(r'(?:^|[\s,<])(%s)(?:$|[\s,>])' % template_name, args)
407        if len(matcherTemplateArgs) < len(templateArgs):
408          # The template name is used naked, so don't replace with `*`` later on
409          template_name = None
410        else :
411          args = re.sub(r'(^|[\s,<])%s($|[\s,>])' % template_name, r'\1*\2', args)
412      args = ', '.join(p.strip() for p in args.split(','))
413      m = re.match(r'(?:^|.*\s+)internal::(?:Bindable)?Matcher<([^>]+)>$', result)
414      if m:
415        result_types = [m.group(1)]
416        if template_name and len(result_types) is 1 and result_types[0] == template_name:
417          result_types = ['*']
418      else:
419        result_types = extract_result_types(comment)
420      if not result_types:
421        if not comment:
422          # Only overloads don't have their own doxygen comments; ignore those.
423          print('Ignoring "%s"' % name)
424        else:
425          print('Cannot determine result type for "%s"' % name)
426      else:
427        for result_type in result_types:
428          add_matcher(result_type, name, args, comment)
429    else:
430      print('*** Unparsable: "' + declaration + '" ***')
431
432def sort_table(matcher_type, matcher_map):
433  """Returns the sorted html table for the given row map."""
434  table = ''
435  for key in sorted(matcher_map.keys()):
436    table += matcher_map[key] + '\n'
437  return ('<!-- START_%(type)s_MATCHERS -->\n' +
438          '%(table)s' +
439          '<!--END_%(type)s_MATCHERS -->') % {
440    'type': matcher_type,
441    'table': table,
442  }
443
444# Parse the ast matchers.
445# We alternate between two modes:
446# body = True: We parse the definition of a matcher. We need
447#   to parse the full definition before adding a matcher, as the
448#   definition might contain static asserts that specify the result
449#   type.
450# body = False: We parse the comments and declaration of the matcher.
451comment = ''
452declaration = ''
453allowed_types = []
454body = False
455for line in open(MATCHERS_FILE).read().splitlines():
456  if body:
457    if line.strip() and line[0] == '}':
458      if declaration:
459        act_on_decl(declaration, comment, allowed_types)
460        comment = ''
461        declaration = ''
462        allowed_types = []
463      body = False
464    else:
465      m = re.search(r'is_base_of<([^,]+), NodeType>', line)
466      if m and m.group(1):
467        allowed_types += [m.group(1)]
468    continue
469  if line.strip() and line.lstrip()[0] == '/':
470    comment += re.sub(r'^/+\s?', '', line) + '\n'
471  else:
472    declaration += ' ' + line
473    if ((not line.strip()) or
474        line.rstrip()[-1] == ';' or
475        (line.rstrip()[-1] == '{' and line.rstrip()[-3:] != '= {')):
476      if line.strip() and line.rstrip()[-1] == '{':
477        body = True
478      else:
479        act_on_decl(declaration, comment, allowed_types)
480        comment = ''
481        declaration = ''
482        allowed_types = []
483
484node_matcher_table = sort_table('DECL', node_matchers)
485narrowing_matcher_table = sort_table('NARROWING', narrowing_matchers)
486traversal_matcher_table = sort_table('TRAVERSAL', traversal_matchers)
487
488reference = open('../LibASTMatchersReference.html').read()
489reference = re.sub(r'<!-- START_DECL_MATCHERS.*END_DECL_MATCHERS -->',
490                   node_matcher_table, reference, flags=re.S)
491reference = re.sub(r'<!-- START_NARROWING_MATCHERS.*END_NARROWING_MATCHERS -->',
492                   narrowing_matcher_table, reference, flags=re.S)
493reference = re.sub(r'<!-- START_TRAVERSAL_MATCHERS.*END_TRAVERSAL_MATCHERS -->',
494                   traversal_matcher_table, reference, flags=re.S)
495
496with open('../LibASTMatchersReference.html', 'wb') as output:
497  output.write(reference)
498
499