1 /* Copyright 2019 The TensorFlow Authors. All Rights Reserved.
2 
3 Licensed under the Apache License, Version 2.0 (the "License");
4 you may not use this file except in compliance with the License.
5 You may obtain a copy of the License at
6 
7     http://www.apache.org/licenses/LICENSE-2.0
8 
9 Unless required by applicable law or agreed to in writing, software
10 distributed under the License is distributed on an "AS IS" BASIS,
11 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 See the License for the specific language governing permissions and
13 limitations under the License.
14 ==============================================================================*/
15 #ifndef TENSORFLOW_LITE_MINIMAL_LOGGING_H_
16 #define TENSORFLOW_LITE_MINIMAL_LOGGING_H_
17 
18 #include <cstdarg>
19 
20 namespace tflite {
21 
22 enum LogSeverity {
23   TFLITE_LOG_INFO = 0,
24   TFLITE_LOG_WARNING = 1,
25   TFLITE_LOG_ERROR = 2,
26 };
27 
28 namespace logging_internal {
29 
30 // Helper class for simple platform-specific console logging. Note that we
31 // explicitly avoid the convenience of ostream-style logging to minimize binary
32 // size impact.
33 class MinimalLogger {
34  public:
35   // Logging hook that takes variadic args.
36   static void Log(LogSeverity severity, const char* format, ...);
37 
38   // Logging hook that takes a formatted va_list.
39   static void LogFormatted(LogSeverity severity, const char* format,
40                            va_list args);
41 
42  private:
43   static const char* GetSeverityName(LogSeverity severity);
44 };
45 
46 }  // namespace logging_internal
47 }  // namespace tflite
48 
49 // Convenience macro for basic internal logging in production builds.
50 // Note: This should never be used for debug-type logs, as it will *not* be
51 // stripped in release optimized builds. In general, prefer the error reporting
52 // APIs for developer-facing errors, and only use this for diagnostic output
53 // that should always be logged in user builds.
54 #define TFLITE_LOG_PROD(severity, format, ...) \
55   tflite::logging_internal::MinimalLogger::Log(severity, format, ##__VA_ARGS__);
56 
57 // Convenience macro for logging a statement *once* for a given process lifetime
58 // in production builds.
59 #define TFLITE_LOG_PROD_ONCE(severity, format, ...)    \
60   do {                                                 \
61     static const bool s_logged = [&] {                 \
62       TFLITE_LOG_PROD(severity, format, ##__VA_ARGS__) \
63       return true;                                     \
64     }();                                               \
65     (void)s_logged;                                    \
66   } while (false);
67 
68 #ifndef NDEBUG
69 // In debug builds, always log.
70 #define TFLITE_LOG TFLITE_LOG_PROD
71 #define TFLITE_LOG_ONCE TFLITE_LOG_PROD_ONCE
72 #else
73 // In prod builds, never log, but ensure the code is well-formed and compiles.
74 #define TFLITE_LOG(severity, format, ...)             \
75   while (false) {                                     \
76     TFLITE_LOG_PROD(severity, format, ##__VA_ARGS__); \
77   }
78 #define TFLITE_LOG_ONCE TFLITE_LOG
79 #endif
80 
81 #endif  // TENSORFLOW_LITE_MINIMAL_LOGGING_H_
82