Home | History | Annotate | Download | only in android
      1 /*
      2  * Copyright (C) 2009 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 #ifndef _ANDROID_LOG_H
     18 #define _ANDROID_LOG_H
     19 
     20 /******************************************************************
     21  *
     22  * IMPORTANT NOTICE:
     23  *
     24  *   This file is part of Android's set of stable system headers
     25  *   exposed by the Android NDK (Native Development Kit) since
     26  *   platform release 1.5
     27  *
     28  *   Third-party source AND binary code relies on the definitions
     29  *   here to be FROZEN ON ALL UPCOMING PLATFORM RELEASES.
     30  *
     31  *   - DO NOT MODIFY ENUMS (EXCEPT IF YOU ADD NEW 32-BIT VALUES)
     32  *   - DO NOT MODIFY CONSTANTS OR FUNCTIONAL MACROS
     33  *   - DO NOT CHANGE THE SIGNATURE OF FUNCTIONS IN ANY WAY
     34  *   - DO NOT CHANGE THE LAYOUT OR SIZE OF STRUCTURES
     35  */
     36 
     37 /**
     38  * \file
     39  *
     40  * Support routines to send messages to the Android log buffer,
     41  * which can later be accessed through the `logcat` utility.
     42  *
     43  * Each log message must have
     44  *   - a priority
     45  *   - a log tag
     46  *   - some text
     47  *
     48  * The tag normally corresponds to the component that emits the log message,
     49  * and should be reasonably small.
     50  *
     51  * Log message text may be truncated to less than an implementation-specific
     52  * limit (1023 bytes).
     53  *
     54  * Note that a newline character ("\n") will be appended automatically to your
     55  * log message, if not already there. It is not possible to send several
     56  * messages and have them appear on a single line in logcat.
     57  *
     58  * Please use logging in moderation:
     59  *
     60  *  - Sending log messages eats CPU and slow down your application and the
     61  *    system.
     62  *
     63  *  - The circular log buffer is pretty small, so sending many messages
     64  *    will hide other important log messages.
     65  *
     66  *  - In release builds, only send log messages to account for exceptional
     67  *    conditions.
     68  */
     69 
     70 #include <stdarg.h>
     71 
     72 #ifdef __cplusplus
     73 extern "C" {
     74 #endif
     75 
     76 /**
     77  * Android log priority values, in increasing order of priority.
     78  */
     79 typedef enum android_LogPriority {
     80   /** For internal use only.  */
     81   ANDROID_LOG_UNKNOWN = 0,
     82   /** The default priority, for internal use only.  */
     83   ANDROID_LOG_DEFAULT, /* only for SetMinPriority() */
     84   /** Verbose logging. Should typically be disabled for a release apk. */
     85   ANDROID_LOG_VERBOSE,
     86   /** Debug logging. Should typically be disabled for a release apk. */
     87   ANDROID_LOG_DEBUG,
     88   /** Informational logging. Should typically be disabled for a release apk. */
     89   ANDROID_LOG_INFO,
     90   /** Warning logging. For use with recoverable failures. */
     91   ANDROID_LOG_WARN,
     92   /** Error logging. For use with unrecoverable failures. */
     93   ANDROID_LOG_ERROR,
     94   /** Fatal logging. For use when aborting. */
     95   ANDROID_LOG_FATAL,
     96   /** For internal use only.  */
     97   ANDROID_LOG_SILENT, /* only for SetMinPriority(); must be last */
     98 } android_LogPriority;
     99 
    100 /**
    101  * Writes the constant string `text` to the log, with priority `prio` and tag
    102  * `tag`.
    103  */
    104 int __android_log_write(int prio, const char* tag, const char* text);
    105 
    106 /**
    107  * Writes a formatted string to the log, with priority `prio` and tag `tag`.
    108  * The details of formatting are the same as for
    109  * [printf(3)](http://man7.org/linux/man-pages/man3/printf.3.html).
    110  */
    111 int __android_log_print(int prio, const char* tag, const char* fmt, ...)
    112 #if defined(__GNUC__)
    113 #ifdef __USE_MINGW_ANSI_STDIO
    114 #if __USE_MINGW_ANSI_STDIO
    115     __attribute__((__format__(gnu_printf, 3, 4)))
    116 #else
    117     __attribute__((__format__(printf, 3, 4)))
    118 #endif
    119 #else
    120     __attribute__((__format__(printf, 3, 4)))
    121 #endif
    122 #endif
    123     ;
    124 
    125 /**
    126  * Equivalent to `__android_log_print`, but taking a `va_list`.
    127  * (If `__android_log_print` is like `printf`, this is like `vprintf`.)
    128  */
    129 int __android_log_vprint(int prio, const char* tag, const char* fmt, va_list ap)
    130 #if defined(__GNUC__)
    131 #ifdef __USE_MINGW_ANSI_STDIO
    132 #if __USE_MINGW_ANSI_STDIO
    133     __attribute__((__format__(gnu_printf, 3, 0)))
    134 #else
    135     __attribute__((__format__(printf, 3, 0)))
    136 #endif
    137 #else
    138     __attribute__((__format__(printf, 3, 0)))
    139 #endif
    140 #endif
    141     ;
    142 
    143 /**
    144  * Writes an assertion failure to the log (as `ANDROID_LOG_FATAL`) and to
    145  * stderr, before calling
    146  * [abort(3)](http://man7.org/linux/man-pages/man3/abort.3.html).
    147  *
    148  * If `fmt` is non-null, `cond` is unused. If `fmt` is null, the string
    149  * `Assertion failed: %s` is used with `cond` as the string argument.
    150  * If both `fmt` and `cond` are null, a default string is provided.
    151  *
    152  * Most callers should use
    153  * [assert(3)](http://man7.org/linux/man-pages/man3/assert.3.html) from
    154  * `<assert.h>` instead, or the `__assert` and `__assert2` functions provided by
    155  * bionic if more control is needed. They support automatically including the
    156  * source filename and line number more conveniently than this function.
    157  */
    158 void __android_log_assert(const char* cond, const char* tag, const char* fmt,
    159                           ...)
    160 #if defined(__GNUC__)
    161     __attribute__((__noreturn__))
    162 #ifdef __USE_MINGW_ANSI_STDIO
    163 #if __USE_MINGW_ANSI_STDIO
    164     __attribute__((__format__(gnu_printf, 3, 4)))
    165 #else
    166     __attribute__((__format__(printf, 3, 4)))
    167 #endif
    168 #else
    169     __attribute__((__format__(printf, 3, 4)))
    170 #endif
    171 #endif
    172     ;
    173 
    174 #ifndef log_id_t_defined
    175 #define log_id_t_defined
    176 typedef enum log_id {
    177   LOG_ID_MIN = 0,
    178 
    179   LOG_ID_MAIN = 0,
    180   LOG_ID_RADIO = 1,
    181   LOG_ID_EVENTS = 2,
    182   LOG_ID_SYSTEM = 3,
    183   LOG_ID_CRASH = 4,
    184   LOG_ID_STATS = 5,
    185   LOG_ID_SECURITY = 6,
    186   LOG_ID_KERNEL = 7, /* place last, third-parties can not use it */
    187 
    188   LOG_ID_MAX
    189 } log_id_t;
    190 #endif
    191 
    192 /*
    193  * Send a simple string to the log.
    194  */
    195 int __android_log_buf_write(int bufID, int prio, const char* tag,
    196                             const char* text);
    197 int __android_log_buf_print(int bufID, int prio, const char* tag,
    198                             const char* fmt, ...)
    199 #if defined(__GNUC__)
    200     __attribute__((__format__(printf, 4, 5)))
    201 #endif
    202     ;
    203 
    204 #ifdef __cplusplus
    205 }
    206 #endif
    207 
    208 #endif /* _ANDROID_LOG_H */
    209