1// Copyright (c) 2007, Google Inc.
2// All rights reserved.
3//
4// Redistribution and use in source and binary forms, with or without
5// modification, are permitted provided that the following conditions are
6// met:
7//
8//     * Redistributions of source code must retain the above copyright
9// notice, this list of conditions and the following disclaimer.
10//     * Redistributions in binary form must reproduce the above
11// copyright notice, this list of conditions and the following disclaimer
12// in the documentation and/or other materials provided with the
13// distribution.
14//     * Neither the name of Google Inc. nor the names of its
15// contributors may be used to endorse or promote products derived from
16// this software without specific prior written permission.
17//
18// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
21// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
22// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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24// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
28// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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_
71namespace 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.
77typedef std::ostream LogMessage;
78
79}  // namespace base_logging
80#endif  // THIRD_PARTY_BREAKPAD_GOOGLE_GLUE_LOGGING_H_
81
82namespace 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
93class 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".
124class LogMessageVoidify {
125 public:
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".
134string HexString(uint32_t number);
135string HexString(uint64_t number);
136string 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.
141int 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