1 /*
2 * Copyright (C) 2005-2017 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 #pragma once
18
19 #include <stdbool.h>
20 #include <sys/cdefs.h>
21 #include <sys/types.h>
22
23 #include <android/log.h>
24
25 __BEGIN_DECLS
26
27 /*
28 * Normally we strip the effects of ALOGV (VERBOSE messages),
29 * LOG_FATAL and LOG_FATAL_IF (FATAL assert messages) from the
30 * release builds be defining NDEBUG. You can modify this (for
31 * example with "#define LOG_NDEBUG 0" at the top of your source
32 * file) to change that behavior.
33 */
34
35 #ifndef LOG_NDEBUG
36 #ifdef NDEBUG
37 #define LOG_NDEBUG 1
38 #else
39 #define LOG_NDEBUG 0
40 #endif
41 #endif
42
43 /* --------------------------------------------------------------------- */
44
45 /*
46 * This file uses ", ## __VA_ARGS__" zero-argument token pasting to
47 * work around issues with debug-only syntax errors in assertions
48 * that are missing format strings. See commit
49 * 19299904343daf191267564fe32e6cd5c165cd42
50 */
51 #if defined(__clang__)
52 #pragma clang diagnostic push
53 #pragma clang diagnostic ignored "-Wgnu-zero-variadic-macro-arguments"
54 #endif
55
56 /*
57 * Use __VA_ARGS__ if running a static analyzer,
58 * to avoid warnings of unused variables in __VA_ARGS__.
59 * Use constexpr function in C++ mode, so these macros can be used
60 * in other constexpr functions without warning.
61 */
62 #ifdef __clang_analyzer__
63 #ifdef __cplusplus
64 extern "C++" {
65 template <typename... Ts>
__fake_use_va_args(Ts...)66 constexpr int __fake_use_va_args(Ts...) {
67 return 0;
68 }
69 }
70 #else
71 extern int __fake_use_va_args(int, ...);
72 #endif /* __cplusplus */
73 #define __FAKE_USE_VA_ARGS(...) ((void)__fake_use_va_args(0, ##__VA_ARGS__))
74 #else
75 #define __FAKE_USE_VA_ARGS(...) ((void)(0))
76 #endif /* __clang_analyzer__ */
77
78 #ifndef __predict_false
79 #define __predict_false(exp) __builtin_expect((exp) != 0, 0)
80 #endif
81
82 #define android_writeLog(prio, tag, text) __android_log_write(prio, tag, text)
83
84 #define android_printLog(prio, tag, ...) \
85 __android_log_print(prio, tag, __VA_ARGS__)
86
87 #define android_vprintLog(prio, cond, tag, ...) \
88 __android_log_vprint(prio, tag, __VA_ARGS__)
89
90 /*
91 * Log macro that allows you to specify a number for the priority.
92 */
93 #ifndef LOG_PRI
94 #define LOG_PRI(priority, tag, ...) android_printLog(priority, tag, __VA_ARGS__)
95 #endif
96
97 /*
98 * Log macro that allows you to pass in a varargs ("args" is a va_list).
99 */
100 #ifndef LOG_PRI_VA
101 #define LOG_PRI_VA(priority, tag, fmt, args) \
102 android_vprintLog(priority, NULL, tag, fmt, args)
103 #endif
104
105 /* --------------------------------------------------------------------- */
106
107 /* XXX Macros to work around syntax errors in places where format string
108 * arg is not passed to ALOG_ASSERT, LOG_ALWAYS_FATAL or LOG_ALWAYS_FATAL_IF
109 * (happens only in debug builds).
110 */
111
112 /* Returns 2nd arg. Used to substitute default value if caller's vararg list
113 * is empty.
114 */
115 #define __android_second(dummy, second, ...) second
116
117 /* If passed multiple args, returns ',' followed by all but 1st arg, otherwise
118 * returns nothing.
119 */
120 #define __android_rest(first, ...) , ##__VA_ARGS__
121
122 #define android_printAssert(cond, tag, ...) \
123 __android_log_assert(cond, tag, \
124 __android_second(0, ##__VA_ARGS__, NULL) \
125 __android_rest(__VA_ARGS__))
126
127 /*
128 * Log a fatal error. If the given condition fails, this stops program
129 * execution like a normal assertion, but also generating the given message.
130 * It is NOT stripped from release builds. Note that the condition test
131 * is -inverted- from the normal assert() semantics.
132 */
133 #ifndef LOG_ALWAYS_FATAL_IF
134 #define LOG_ALWAYS_FATAL_IF(cond, ...) \
135 ((__predict_false(cond)) ? (__FAKE_USE_VA_ARGS(__VA_ARGS__), \
136 ((void)android_printAssert(#cond, LOG_TAG, ##__VA_ARGS__))) \
137 : ((void)0))
138 #endif
139
140 #ifndef LOG_ALWAYS_FATAL
141 #define LOG_ALWAYS_FATAL(...) \
142 (((void)android_printAssert(NULL, LOG_TAG, ##__VA_ARGS__)))
143 #endif
144
145 /*
146 * Versions of LOG_ALWAYS_FATAL_IF and LOG_ALWAYS_FATAL that
147 * are stripped out of release builds.
148 */
149
150 #if LOG_NDEBUG
151
152 #ifndef LOG_FATAL_IF
153 #define LOG_FATAL_IF(cond, ...) __FAKE_USE_VA_ARGS(__VA_ARGS__)
154 #endif
155 #ifndef LOG_FATAL
156 #define LOG_FATAL(...) __FAKE_USE_VA_ARGS(__VA_ARGS__)
157 #endif
158
159 #else
160
161 #ifndef LOG_FATAL_IF
162 #define LOG_FATAL_IF(cond, ...) LOG_ALWAYS_FATAL_IF(cond, ##__VA_ARGS__)
163 #endif
164 #ifndef LOG_FATAL
165 #define LOG_FATAL(...) LOG_ALWAYS_FATAL(__VA_ARGS__)
166 #endif
167
168 #endif
169
170 /*
171 * Assertion that generates a log message when the assertion fails.
172 * Stripped out of release builds. Uses the current LOG_TAG.
173 */
174 #ifndef ALOG_ASSERT
175 #define ALOG_ASSERT(cond, ...) LOG_FATAL_IF(!(cond), ##__VA_ARGS__)
176 #endif
177
178 /* --------------------------------------------------------------------- */
179
180 /*
181 * C/C++ logging functions. See the logging documentation for API details.
182 *
183 * We'd like these to be available from C code (in case we import some from
184 * somewhere), so this has a C interface.
185 *
186 * The output will be correct when the log file is shared between multiple
187 * threads and/or multiple processes so long as the operating system
188 * supports O_APPEND. These calls have mutex-protected data structures
189 * and so are NOT reentrant. Do not use LOG in a signal handler.
190 */
191
192 /* --------------------------------------------------------------------- */
193
194 /*
195 * Simplified macro to send a verbose log message using the current LOG_TAG.
196 */
197 #ifndef ALOGV
198 #define __ALOGV(...) ((void)ALOG(LOG_VERBOSE, LOG_TAG, __VA_ARGS__))
199 #if LOG_NDEBUG
200 #define ALOGV(...) \
201 do { \
202 __FAKE_USE_VA_ARGS(__VA_ARGS__); \
203 if (false) { \
204 __ALOGV(__VA_ARGS__); \
205 } \
206 } while (false)
207 #else
208 #define ALOGV(...) __ALOGV(__VA_ARGS__)
209 #endif
210 #endif
211
212 #ifndef ALOGV_IF
213 #if LOG_NDEBUG
214 #define ALOGV_IF(cond, ...) __FAKE_USE_VA_ARGS(__VA_ARGS__)
215 #else
216 #define ALOGV_IF(cond, ...) \
217 ((__predict_false(cond)) \
218 ? (__FAKE_USE_VA_ARGS(__VA_ARGS__), (void)ALOG(LOG_VERBOSE, LOG_TAG, __VA_ARGS__)) \
219 : ((void)0))
220 #endif
221 #endif
222
223 /*
224 * Simplified macro to send a debug log message using the current LOG_TAG.
225 */
226 #ifndef ALOGD
227 #define ALOGD(...) ((void)ALOG(LOG_DEBUG, LOG_TAG, __VA_ARGS__))
228 #endif
229
230 #ifndef ALOGD_IF
231 #define ALOGD_IF(cond, ...) \
232 ((__predict_false(cond)) \
233 ? (__FAKE_USE_VA_ARGS(__VA_ARGS__), (void)ALOG(LOG_DEBUG, LOG_TAG, __VA_ARGS__)) \
234 : ((void)0))
235 #endif
236
237 /*
238 * Simplified macro to send an info log message using the current LOG_TAG.
239 */
240 #ifndef ALOGI
241 #define ALOGI(...) ((void)ALOG(LOG_INFO, LOG_TAG, __VA_ARGS__))
242 #endif
243
244 #ifndef ALOGI_IF
245 #define ALOGI_IF(cond, ...) \
246 ((__predict_false(cond)) \
247 ? (__FAKE_USE_VA_ARGS(__VA_ARGS__), (void)ALOG(LOG_INFO, LOG_TAG, __VA_ARGS__)) \
248 : ((void)0))
249 #endif
250
251 /*
252 * Simplified macro to send a warning log message using the current LOG_TAG.
253 */
254 #ifndef ALOGW
255 #define ALOGW(...) ((void)ALOG(LOG_WARN, LOG_TAG, __VA_ARGS__))
256 #endif
257
258 #ifndef ALOGW_IF
259 #define ALOGW_IF(cond, ...) \
260 ((__predict_false(cond)) \
261 ? (__FAKE_USE_VA_ARGS(__VA_ARGS__), (void)ALOG(LOG_WARN, LOG_TAG, __VA_ARGS__)) \
262 : ((void)0))
263 #endif
264
265 /*
266 * Simplified macro to send an error log message using the current LOG_TAG.
267 */
268 #ifndef ALOGE
269 #define ALOGE(...) ((void)ALOG(LOG_ERROR, LOG_TAG, __VA_ARGS__))
270 #endif
271
272 #ifndef ALOGE_IF
273 #define ALOGE_IF(cond, ...) \
274 ((__predict_false(cond)) \
275 ? (__FAKE_USE_VA_ARGS(__VA_ARGS__), (void)ALOG(LOG_ERROR, LOG_TAG, __VA_ARGS__)) \
276 : ((void)0))
277 #endif
278
279 /* --------------------------------------------------------------------- */
280
281 /*
282 * Conditional based on whether the current LOG_TAG is enabled at
283 * verbose priority.
284 */
285 #ifndef IF_ALOGV
286 #if LOG_NDEBUG
287 #define IF_ALOGV() if (false)
288 #else
289 #define IF_ALOGV() IF_ALOG(LOG_VERBOSE, LOG_TAG)
290 #endif
291 #endif
292
293 /*
294 * Conditional based on whether the current LOG_TAG is enabled at
295 * debug priority.
296 */
297 #ifndef IF_ALOGD
298 #define IF_ALOGD() IF_ALOG(LOG_DEBUG, LOG_TAG)
299 #endif
300
301 /*
302 * Conditional based on whether the current LOG_TAG is enabled at
303 * info priority.
304 */
305 #ifndef IF_ALOGI
306 #define IF_ALOGI() IF_ALOG(LOG_INFO, LOG_TAG)
307 #endif
308
309 /*
310 * Conditional based on whether the current LOG_TAG is enabled at
311 * warn priority.
312 */
313 #ifndef IF_ALOGW
314 #define IF_ALOGW() IF_ALOG(LOG_WARN, LOG_TAG)
315 #endif
316
317 /*
318 * Conditional based on whether the current LOG_TAG is enabled at
319 * error priority.
320 */
321 #ifndef IF_ALOGE
322 #define IF_ALOGE() IF_ALOG(LOG_ERROR, LOG_TAG)
323 #endif
324
325 /* --------------------------------------------------------------------- */
326
327 /*
328 * Basic log message macro.
329 *
330 * Example:
331 * ALOG(LOG_WARN, NULL, "Failed with error %d", errno);
332 *
333 * The second argument may be NULL or "" to indicate the "global" tag.
334 */
335 #ifndef ALOG
336 #define ALOG(priority, tag, ...) LOG_PRI(ANDROID_##priority, tag, __VA_ARGS__)
337 #endif
338
339 /*
340 * Conditional given a desired logging priority and tag.
341 */
342 #ifndef IF_ALOG
343 #define IF_ALOG(priority, tag) if (android_testLog(ANDROID_##priority, tag))
344 #endif
345
346 /* --------------------------------------------------------------------- */
347
348 /*
349 * IF_ALOG uses android_testLog, but IF_ALOG can be overridden.
350 * android_testLog will remain constant in its purpose as a wrapper
351 * for Android logging filter policy, and can be subject to
352 * change. It can be reused by the developers that override
353 * IF_ALOG as a convenient means to reimplement their policy
354 * over Android.
355 */
356
357 /*
358 * Use the per-tag properties "log.tag.<tagname>" to generate a runtime
359 * result of non-zero to expose a log. prio is ANDROID_LOG_VERBOSE to
360 * ANDROID_LOG_FATAL. default_prio if no property. Undefined behavior if
361 * any other value.
362 */
363 int __android_log_is_loggable(int prio, const char* tag, int default_prio);
364 int __android_log_is_loggable_len(int prio, const char* tag, size_t len, int default_prio);
365
366 #if LOG_NDEBUG /* Production */
367 #define android_testLog(prio, tag) \
368 (__android_log_is_loggable_len(prio, tag, (tag) ? strlen(tag) : 0, ANDROID_LOG_DEBUG) != 0)
369 #else
370 #define android_testLog(prio, tag) \
371 (__android_log_is_loggable_len(prio, tag, (tag) ? strlen(tag) : 0, ANDROID_LOG_VERBOSE) != 0)
372 #endif
373
374 #if defined(__clang__)
375 #pragma clang diagnostic pop
376 #endif
377
378 __END_DECLS
379