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
64extern "C++" {
65template <typename... Ts>
66constexpr int __fake_use_va_args(Ts...) {
67  return 0;
68}
69}
70#else
71extern 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 */
363int __android_log_is_loggable(int prio, const char* tag, int default_prio);
364int __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