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29 
30 // logging.h: Breakpad logging
31 //
32 // Breakpad itself uses Breakpad logging with statements of the form:
33 //   BPLOG(severity) << "message";
34 // severity may be INFO, ERROR, or other values defined in this file.
35 //
36 // BPLOG is an overridable macro so that users can customize Breakpad's
37 // logging.  Left at the default, logging messages are sent to stderr along
38 // with a timestamp and the source code location that produced a message.
39 // The streams may be changed by redefining BPLOG_*_STREAM, the logging
40 // behavior may be changed by redefining BPLOG_*, and the entire logging
41 // system may be overridden by redefining BPLOG(severity).  These
42 // redefinitions may be passed to the preprocessor as a command-line flag
43 // (-D).
44 //
45 // If an additional header is required to override Breakpad logging, it can
46 // be specified by the BP_LOGGING_INCLUDE macro.  If defined, this header
47 // will #include the header specified by that macro.
48 //
49 // If any initialization is needed before logging, it can be performed by
50 // a function called through the BPLOG_INIT macro.  Each main function of
51 // an executable program in the Breakpad processor library calls
52 // BPLOG_INIT(&argc, &argv); before any logging can be performed; define
53 // BPLOG_INIT appropriately if initialization is required.
54 //
55 // Author: Mark Mentovai
56 
57 #ifndef PROCESSOR_LOGGING_H__
58 #define PROCESSOR_LOGGING_H__
59 
60 #include <iostream>
61 #include <string>
62 
63 #include "common/using_std_string.h"
64 #include "google_breakpad/common/breakpad_types.h"
65 
66 #ifdef BP_LOGGING_INCLUDE
67 #include BP_LOGGING_INCLUDE
68 #endif  // BP_LOGGING_INCLUDE
69 
70 #ifndef THIRD_PARTY_BREAKPAD_GOOGLE_GLUE_LOGGING_H_
71 namespace base_logging {
72 
73 // The open-source copy of logging.h has diverged from Google's internal copy
74 // (temporarily, at least).  To support the transition to structured logging
75 // a definition for base_logging::LogMessage is needed, which is a ostream-
76 // like object for streaming arguments to construct a log message.
77 typedef std::ostream LogMessage;
78 
79 }  // namespace base_logging
80 #endif  // THIRD_PARTY_BREAKPAD_GOOGLE_GLUE_LOGGING_H_
81 
82 namespace google_breakpad {
83 
84 // These are defined in Microsoft headers.
85 #ifdef SEVERITY_ERROR
86 #undef SEVERITY_ERROR
87 #endif
88 
89 #ifdef ERROR
90 #undef ERROR
91 #endif
92 
93 class LogStream {
94  public:
95   enum Severity {
96     SEVERITY_INFO,
97     SEVERITY_ERROR
98   };
99 
100   // Begin logging a message to the stream identified by |stream|, at the
101   // indicated severity.  The file and line parameters should be set so as to
102   // identify the line of source code that is producing a message.
103   LogStream(std::ostream &stream, Severity severity,
104             const char *file, int line);
105 
106   // Finish logging by printing a newline and flushing the output stream.
107   ~LogStream();
108 
109   template<typename T> std::ostream& operator<<(const T &t) {
110     return stream_ << t;
111   }
112 
113  private:
114   std::ostream &stream_;
115 
116   // Disallow copy constructor and assignment operator
117   explicit LogStream(const LogStream &that);
118   void operator=(const LogStream &that);
119 };
120 
121 // This class is used to explicitly ignore values in the conditional logging
122 // macros.  This avoids compiler warnings like "value computed is not used"
123 // and "statement has no effect".
124 class LogMessageVoidify {
125  public:
LogMessageVoidify()126   LogMessageVoidify() {}
127 
128   // This has to be an operator with a precedence lower than << but higher
129   // than ?:
130   void operator&(base_logging::LogMessage &) {}
131 };
132 
133 // Returns number formatted as a hexadecimal string, such as "0x7b".
134 string HexString(uint32_t number);
135 string HexString(uint64_t number);
136 string HexString(int number);
137 
138 // Returns the error code as set in the global errno variable, and sets
139 // error_string, a required argument, to a string describing that error
140 // code.
141 int ErrnoString(string *error_string);
142 
143 }  // namespace google_breakpad
144 
145 #ifndef BPLOG_INIT
146 #define BPLOG_INIT(pargc, pargv)
147 #endif  // BPLOG_INIT
148 
149 #define BPLOG_LAZY_STREAM(stream, condition) \
150     !(condition) ? (void) 0 : \
151                    google_breakpad::LogMessageVoidify() & (BPLOG_ ## stream)
152 
153 #ifndef BPLOG_MINIMUM_SEVERITY
154 #define BPLOG_MINIMUM_SEVERITY SEVERITY_INFO
155 #endif
156 
157 #define BPLOG_LOG_IS_ON(severity) \
158     ((google_breakpad::LogStream::SEVERITY_ ## severity) >= \
159      (google_breakpad::LogStream::BPLOG_MINIMUM_SEVERITY))
160 
161 #ifndef BPLOG
162 #define BPLOG(severity) BPLOG_LAZY_STREAM(severity, BPLOG_LOG_IS_ON(severity))
163 #endif  // BPLOG
164 
165 #ifndef BPLOG_INFO
166 #ifndef BPLOG_INFO_STREAM
167 #define BPLOG_INFO_STREAM std::clog
168 #endif  // BPLOG_INFO_STREAM
169 #define BPLOG_INFO google_breakpad::LogStream(BPLOG_INFO_STREAM, \
170                        google_breakpad::LogStream::SEVERITY_INFO, \
171                        __FILE__, __LINE__)
172 #endif  // BPLOG_INFO
173 
174 #ifndef BPLOG_ERROR
175 #ifndef BPLOG_ERROR_STREAM
176 #define BPLOG_ERROR_STREAM std::cerr
177 #endif  // BPLOG_ERROR_STREAM
178 #define BPLOG_ERROR google_breakpad::LogStream(BPLOG_ERROR_STREAM, \
179                         google_breakpad::LogStream::SEVERITY_ERROR, \
180                         __FILE__, __LINE__)
181 #endif  // BPLOG_ERROR
182 
183 #define BPLOG_IF(severity, condition) \
184     BPLOG_LAZY_STREAM(severity, ((condition) && BPLOG_LOG_IS_ON(severity)))
185 
186 #endif  // PROCESSOR_LOGGING_H__
187