1 | /* |
2 | * Copyright Andrey Semashev 2007 - 2015. |
3 | * Distributed under the Boost Software License, Version 1.0. |
4 | * (See accompanying file LICENSE_1_0.txt or copy at |
5 | * http://www.boost.org/LICENSE_1_0.txt) |
6 | */ |
7 | /*! |
8 | * \file format_parser.cpp |
9 | * \author Andrey Semashev |
10 | * \date 16.11.2012 |
11 | * |
12 | * \brief This header is the Boost.Log library implementation, see the library documentation |
13 | * at http://www.boost.org/doc/libs/release/libs/log/doc/html/index.html. |
14 | */ |
15 | |
16 | #include <boost/log/detail/config.hpp> |
17 | #include <string> |
18 | #include <algorithm> |
19 | #include <boost/throw_exception.hpp> |
20 | #include <boost/exception/exception.hpp> |
21 | #include <boost/move/core.hpp> |
22 | #include <boost/move/utility_core.hpp> |
23 | #include <boost/spirit/include/qi_uint.hpp> |
24 | #include <boost/spirit/include/qi_parse.hpp> |
25 | #include <boost/log/detail/format.hpp> |
26 | #include <boost/log/exceptions.hpp> |
27 | #include <boost/log/support/exception.hpp> |
28 | #include "spirit_encoding.hpp" |
29 | #include <boost/log/detail/header.hpp> |
30 | |
31 | namespace qi = boost::spirit::qi; |
32 | |
33 | namespace boost { |
34 | |
35 | BOOST_LOG_OPEN_NAMESPACE |
36 | |
37 | namespace aux { |
38 | |
39 | template< typename CharT > |
40 | BOOST_LOG_API format_description< CharT > parse_format(const CharT* begin, const CharT* end) |
41 | { |
42 | typedef CharT char_type; |
43 | typedef format_description< char_type > description; |
44 | typedef typename encoding< char_type >::type traits; |
45 | |
46 | const char_type* original_begin = begin; |
47 | description descr; |
48 | unsigned int literal_start_pos = 0; |
49 | |
50 | while (begin != end) |
51 | { |
52 | const char_type* p = std::find(begin, end, static_cast< char_type >('%')); |
53 | descr.literal_chars.append(begin, p); |
54 | |
55 | if ((end - p) >= 2) |
56 | { |
57 | // Check for a percent placeholder |
58 | char_type c = p[1]; |
59 | if (c == static_cast< char_type >('%')) |
60 | { |
61 | descr.literal_chars.push_back(static_cast< char_type >('%')); |
62 | begin = p + 2; |
63 | continue; |
64 | } |
65 | |
66 | // From here on, no more literals are possible. Append the literal element. |
67 | { |
68 | const unsigned int literal_chars_size = static_cast< unsigned int >(descr.literal_chars.size()); |
69 | if (literal_start_pos < literal_chars_size) |
70 | { |
71 | descr.format_elements.push_back(format_element::literal(start_pos: literal_start_pos, len: literal_chars_size - literal_start_pos)); |
72 | literal_start_pos = literal_chars_size; |
73 | } |
74 | } |
75 | |
76 | // Check if this is a positional argument |
77 | if (traits::isdigit(c)) |
78 | { |
79 | if (c != static_cast< char_type >('0')) |
80 | { |
81 | // Positional argument in the form "%N%" |
82 | unsigned int n = 0; |
83 | const char_type* pp = p + 1; |
84 | qi::parse(pp, end, qi::uint_, n); |
85 | if (n == 0 || pp == end || *pp != static_cast< char_type >('%')) |
86 | { |
87 | boost::throw_exception(e: boost::enable_error_info(x: parse_error("Invalid positional format placeholder" )) << boost::throw_file(__FILE__) << boost::throw_line(__LINE__) |
88 | << boost::log::position_info(static_cast< unsigned int >(p - original_begin)) |
89 | ); |
90 | } |
91 | |
92 | // Safety check against ridiculously large argument numbers which would lead to excessive memory consumption. |
93 | // This could be useful if the format string is gathered from an external source (e.g. a config file). |
94 | if (n > 1000) |
95 | { |
96 | boost::throw_exception(e: boost::enable_error_info(x: limitation_error("Positional format placeholder too big" )) << boost::throw_file(__FILE__) << boost::throw_line(__LINE__) |
97 | << boost::log::position_info(static_cast< unsigned int >(p - original_begin)) |
98 | ); |
99 | } |
100 | |
101 | // We count positional arguments from 0, not from 1 as in format strings |
102 | descr.format_elements.push_back(format_element::positional_argument(arg_n: n - 1)); |
103 | begin = pp + 1; // skip the closing '%' |
104 | |
105 | continue; |
106 | } |
107 | else |
108 | { |
109 | // This must be the filler character, not supported yet |
110 | } |
111 | } |
112 | |
113 | // This must be something else, not supported yet |
114 | boost::throw_exception(e: boost::enable_error_info(x: parse_error("Unsupported format placeholder" )) << boost::throw_file(__FILE__) << boost::throw_line(__LINE__) |
115 | << boost::log::position_info(static_cast< unsigned int >(p - original_begin)) |
116 | ); |
117 | } |
118 | else |
119 | { |
120 | if (p != end) |
121 | descr.literal_chars.push_back(static_cast< char_type >('%')); // a single '%' character at the end of the string |
122 | begin = end; |
123 | } |
124 | } |
125 | |
126 | const unsigned int literal_chars_size = static_cast< unsigned int >(descr.literal_chars.size()); |
127 | if (literal_start_pos < literal_chars_size) |
128 | descr.format_elements.push_back(format_element::literal(start_pos: literal_start_pos, len: literal_chars_size - literal_start_pos)); |
129 | |
130 | return BOOST_LOG_NRVO_RESULT(descr); |
131 | } |
132 | |
133 | |
134 | #ifdef BOOST_LOG_USE_CHAR |
135 | |
136 | template BOOST_LOG_API |
137 | format_description< char > parse_format(const char* begin, const char* end); |
138 | |
139 | #endif // BOOST_LOG_USE_CHAR |
140 | |
141 | #ifdef BOOST_LOG_USE_WCHAR_T |
142 | |
143 | template BOOST_LOG_API |
144 | format_description< wchar_t > parse_format(const wchar_t* begin, const wchar_t* end); |
145 | |
146 | #endif // BOOST_LOG_USE_WCHAR_T |
147 | |
148 | } // namespace aux |
149 | |
150 | BOOST_LOG_CLOSE_NAMESPACE // namespace log |
151 | |
152 | } // namespace boost |
153 | |
154 | #include <boost/log/detail/footer.hpp> |
155 | |