clang-tools 10.0.0

cppreference_parser.py
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1 #!/usr/bin/env python
2 #===- cppreference_parser.py - ------------------------------*- python -*--===#
3 #
4 # Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
5 # See https://llvm.org/LICENSE.txt for license information.
6 # SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7 #
8 #===------------------------------------------------------------------------===#
9
10 from bs4 import BeautifulSoup, NavigableString
11
12 import collections
13 import multiprocessing
14 import os
15 import re
16 import signal
17 import sys
18
19
20 class Symbol:
21
22 def __init__(self, name, namespace, headers):
23 # unqualifed symbol name, e.g. "move"
24 self.name = name
25 # namespace of the symbol (with trailing "::"), e.g. "std::", "" (global scope)
26 # None for C symbols.
27 self.namespace = namespace
28 # a list of corresponding headers
29 self.headers = headers
30
31
32 def _HasClass(tag, *classes):
33 for c in tag.get('class', []):
34 if c in classes:
35 return True
36 return False
37
38
39 def _ParseSymbolPage(symbol_page_html, symbol_name):
40 """Parse symbol page and retrieve the include header defined in this page.
41 The symbol page provides header for the symbol, specifically in
42 "Defined in header <header>" section. An example:
43
44 <tr class="t-dsc-header">
45 <td colspan="2"> <div>Defined in header <code>&lt;ratio&gt;</code> </div>
46 </td></tr>
47
48 Returns a list of headers.
49 """
50 headers = set()
51 all_headers = set()
52
53 soup = BeautifulSoup(symbol_page_html, "html.parser")
54 # Rows in table are like:
55 # Defined in header <foo> .t-dsc-header
56 # Defined in header <bar> .t-dsc-header
57 # decl1 .t-dcl
58 # Defined in header <baz> .t-dsc-header
59 # decl2 .t-dcl
60 for table in soup.select('table.t-dcl-begin, table.t-dsc-begin'):
61 current_headers = []
62 was_decl = False
63 for row in table.select('tr'):
64 if _HasClass(row, 't-dcl', 't-dsc'):
65 was_decl = True
66 # Symbols are in the first cell.
67 found_symbols = row.find('td').stripped_strings
68 if not symbol_name in found_symbols:
69 continue
70 headers.update(current_headers)
71 elif _HasClass(row, 't-dsc-header'):
72 # If we saw a decl since the last header, this is a new block of headers
73 # for a new block of decls.
74 if was_decl:
75 current_headers = []
76 was_decl = False
77 # There are also .t-dsc-header for "defined in namespace".
78 if not "Defined in header " in row.text:
79 continue
80 # The interesting header content (e.g. <cstdlib>) is wrapped in <code>.
81 for header_code in row.find_all("code"):
82 current_headers.append(header_code.text)
83 all_headers.add(header_code.text)
84 # If the symbol was never named, consider all named headers.
85 return headers or all_headers
86
87
88 def _ParseIndexPage(index_page_html):
89 """Parse index page.
90 The index page lists all std symbols and hrefs to their detailed pages
91 (which contain the defined header). An example:
92
93 <a href="abs.html" title="abs"><tt>abs()</tt></a> (int) <br>
94 <a href="acos.html" title="acos"><tt>acos()</tt></a> <br>
95
96 Returns a list of tuple (symbol_name, relative_path_to_symbol_page, variant).
97 """
98 symbols = []
99 soup = BeautifulSoup(index_page_html, "html.parser")
100 for symbol_href in soup.select("a[title]"):
101 # Ignore annotated symbols like "acos<>() (std::complex)".
102 # These tend to be overloads, and we the primary is more useful.
103 # This accidentally accepts begin/end despite the (iterator) caption: the
104 # (since C++11) note is first. They are good symbols, so the bug is unfixed.
105 caption = symbol_href.next_sibling
106 variant = isinstance(caption, NavigableString) and "(" in caption
107 symbol_tt = symbol_href.find("tt")
108 if symbol_tt:
109 symbols.append((symbol_tt.text.rstrip("<>()"), # strip any trailing <>()
110 symbol_href["href"], variant))
111 return symbols
112
113
114 def _ReadSymbolPage(path, name):
115 with open(path) as f:
116 return _ParseSymbolPage(f.read(), name)
117
118
119 def _GetSymbols(pool, root_dir, index_page_name, namespace):
120 """Get all symbols listed in the index page. All symbols should be in the
121 given namespace.
122
123 Returns a list of Symbols.
124 """
125
126 # Workflow steps:
127 # 1. Parse index page which lists all symbols to get symbol
128 # name (unqualified name) and its href link to the symbol page which
129 # contains the defined header.
130 # 2. Parse the symbol page to get the defined header.
131 index_page_path = os.path.join(root_dir, index_page_name)
132 with open(index_page_path, "r") as f:
133 # Read each symbol page in parallel.
134 results = [] # (symbol_name, promise of [header...])
135 for symbol_name, symbol_page_path, variant in _ParseIndexPage(f.read()):
136 # Variant symbols (e.g. the std::locale version of isalpha) add ambiguity.
137 # FIXME: use these as a fallback rather than ignoring entirely.
138 if variant:
139 continue
140 path = os.path.join(root_dir, symbol_page_path)
141 results.append((symbol_name,
142 pool.apply_async(_ReadSymbolPage, (path, symbol_name))))
143
144 # Build map from symbol name to a set of headers.
145 symbol_headers = collections.defaultdict(set)
146 for symbol_name, lazy_headers in results:
147 symbol_headers[symbol_name].update(lazy_headers.get())
148
149 symbols = []
150 for name, headers in sorted(symbol_headers.items(), key=lambda t : t[0]):
151 symbols.append(Symbol(name, namespace, list(headers)))
152 return symbols
153
154
155 def GetSymbols(parse_pages):
156 """Get all symbols by parsing the given pages.
157
158 Args:
159 parse_pages: a list of tuples (page_root_dir, index_page_name, namespace)
160 """
161 symbols = []
162 # Run many workers to process individual symbol pages under the symbol index.
163 # Don't allow workers to capture Ctrl-C.
164 pool = multiprocessing.Pool(
165 initializer=lambda: signal.signal(signal.SIGINT, signal.SIG_IGN))
166 try:
167 for root_dir, page_name, namespace in parse_pages:
168 symbols.extend(_GetSymbols(pool, root_dir, page_name, namespace))
169 finally:
170 pool.terminate()
171 pool.join()
172 return symbols
cppreference_parser.GetSymbols
def GetSymbols(parse_pages)
Definition: cppreference_parser.py:155
cppreference_parser.Symbol.headers
headers
Definition: cppreference_parser.py:29
cppreference_parser.Symbol.namespace
namespace
Definition: cppreference_parser.py:27
cppreference_parser.Symbol
Definition: cppreference_parser.py:20
cppreference_parser.Symbol.__init__
def __init__(self, name, namespace, headers)
Definition: cppreference_parser.py:22
cppreference_parser.Symbol.name
name
Definition: cppreference_parser.py:24