logging.cpp revision ac3f7d9a78f9024563cc47f62206c6e3475778dd 
1/*
2 * Copyright (C) 2015 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#ifdef _WIN32
18#include <windows.h>
19#endif
20
21#include "base/logging.h"
22
23#include <libgen.h>
24
25// For getprogname(3) or program_invocation_short_name.
26#if defined(__ANDROID__) || defined(__APPLE__)
27#include <stdlib.h>
28#elif defined(__GLIBC__)
29#include <errno.h>
30#endif
31
32#include <iostream>
33#include <limits>
34#include <sstream>
35#include <string>
36#include <utility>
37#include <vector>
38
39#ifndef _WIN32
40#include <mutex>
41#endif
42
43#include "base/macros.h"
44#include "base/strings.h"
45#include "cutils/threads.h"
46
47// Headers for LogMessage::LogLine.
48#ifdef __ANDROID__
49#include <android/set_abort_message.h>
50#include "cutils/log.h"
51#else
52#include <sys/types.h>
53#include <unistd.h>
54#endif
55
56namespace {
57#ifndef _WIN32
58using std::mutex;
59using std::lock_guard;
60
61#if defined(__GLIBC__)
62const char* getprogname() {
63  return program_invocation_short_name;
64}
65#endif
66
67#else
68const char* getprogname() {
69  static bool first = true;
70  static char progname[MAX_PATH] = {};
71
72  if (first) {
73    // TODO(danalbert): This is a full path on Windows. Just get the basename.
74    DWORD nchars = GetModuleFileName(nullptr, progname, sizeof(progname));
75    DCHECK_GT(nchars, 0U);
76    first = false;
77  }
78
79  return progname;
80}
81
82class mutex {
83 public:
84  mutex() {
85    semaphore_ = CreateSemaphore(nullptr, 1, 1, nullptr);
86    CHECK(semaphore_ != nullptr) << "Failed to create Mutex";
87  }
88  ~mutex() {
89    CloseHandle(semaphore_);
90  }
91
92  void lock() {
93    DWORD result = WaitForSingleObject(semaphore_, INFINITE);
94    CHECK_EQ(result, WAIT_OBJECT_0) << GetLastError();
95  }
96
97  void unlock() {
98    bool result = ReleaseSemaphore(semaphore_, 1, nullptr);
99    CHECK(result);
100  }
101
102 private:
103  HANDLE semaphore_;
104};
105
106template <typename LockT>
107class lock_guard {
108 public:
109  explicit lock_guard(LockT& lock) : lock_(lock) {
110    lock_.lock();
111  }
112
113  ~lock_guard() {
114    lock_.unlock();
115  }
116
117 private:
118  LockT& lock_;
119
120  DISALLOW_COPY_AND_ASSIGN(lock_guard);
121};
122#endif
123} // namespace
124
125namespace android {
126namespace base {
127
128static mutex logging_lock;
129
130#ifdef __ANDROID__
131static LogFunction gLogger = LogdLogger();
132#else
133static LogFunction gLogger = StderrLogger;
134#endif
135
136static bool gInitialized = false;
137static LogSeverity gMinimumLogSeverity = INFO;
138static std::unique_ptr<std::string> gProgramInvocationName;
139
140static const char* ProgramInvocationName() {
141  if (gProgramInvocationName == nullptr) {
142    gProgramInvocationName.reset(new std::string(getprogname()));
143  }
144
145  return gProgramInvocationName->c_str();
146}
147
148void StderrLogger(LogId, LogSeverity severity, const char*, const char* file,
149                  unsigned int line, const char* message) {
150  static const char* log_characters = "VDIWEF";
151  CHECK_EQ(strlen(log_characters), FATAL + 1U);
152  char severity_char = log_characters[severity];
153  fprintf(stderr, "%s %c %5d %5d %s:%u] %s\n", ProgramInvocationName(),
154          severity_char, getpid(), gettid(), file, line, message);
155}
156
157
158#ifdef __ANDROID__
159LogdLogger::LogdLogger(LogId default_log_id) : default_log_id_(default_log_id) {
160}
161
162static const android_LogPriority kLogSeverityToAndroidLogPriority[] = {
163    ANDROID_LOG_VERBOSE, ANDROID_LOG_DEBUG, ANDROID_LOG_INFO,
164    ANDROID_LOG_WARN,    ANDROID_LOG_ERROR, ANDROID_LOG_FATAL,
165};
166static_assert(arraysize(kLogSeverityToAndroidLogPriority) == FATAL + 1,
167              "Mismatch in size of kLogSeverityToAndroidLogPriority and values "
168              "in LogSeverity");
169
170static const log_id kLogIdToAndroidLogId[] = {
171    LOG_ID_MAX, LOG_ID_MAIN, LOG_ID_SYSTEM,
172};
173static_assert(arraysize(kLogIdToAndroidLogId) == SYSTEM + 1,
174              "Mismatch in size of kLogIdToAndroidLogId and values in LogId");
175
176void LogdLogger::operator()(LogId id, LogSeverity severity, const char* tag,
177                            const char* file, unsigned int line,
178                            const char* message) {
179  int priority = kLogSeverityToAndroidLogPriority[severity];
180  if (id == DEFAULT) {
181    id = default_log_id_;
182  }
183
184  log_id lg_id = kLogIdToAndroidLogId[id];
185
186  if (priority == ANDROID_LOG_FATAL) {
187    __android_log_buf_print(lg_id, priority, tag, "%s:%u] %s", file, line,
188                            message);
189  } else {
190    __android_log_buf_print(lg_id, priority, tag, "%s", message);
191  }
192}
193#endif
194
195void InitLogging(char* argv[], LogFunction&& logger) {
196  SetLogger(std::forward<LogFunction>(logger));
197  InitLogging(argv);
198}
199
200void InitLogging(char* argv[]) {
201  if (gInitialized) {
202    return;
203  }
204
205  gInitialized = true;
206
207  // Stash the command line for later use. We can use /proc/self/cmdline on
208  // Linux to recover this, but we don't have that luxury on the Mac, and there
209  // are a couple of argv[0] variants that are commonly used.
210  if (argv != nullptr) {
211    gProgramInvocationName.reset(new std::string(basename(argv[0])));
212  }
213
214  const char* tags = getenv("ANDROID_LOG_TAGS");
215  if (tags == nullptr) {
216    return;
217  }
218
219  std::vector<std::string> specs = Split(tags, " ");
220  for (size_t i = 0; i < specs.size(); ++i) {
221    // "tag-pattern:[vdiwefs]"
222    std::string spec(specs[i]);
223    if (spec.size() == 3 && StartsWith(spec, "*:")) {
224      switch (spec[2]) {
225        case 'v':
226          gMinimumLogSeverity = VERBOSE;
227          continue;
228        case 'd':
229          gMinimumLogSeverity = DEBUG;
230          continue;
231        case 'i':
232          gMinimumLogSeverity = INFO;
233          continue;
234        case 'w':
235          gMinimumLogSeverity = WARNING;
236          continue;
237        case 'e':
238          gMinimumLogSeverity = ERROR;
239          continue;
240        case 'f':
241          gMinimumLogSeverity = FATAL;
242          continue;
243        // liblog will even suppress FATAL if you say 's' for silent, but that's
244        // crazy!
245        case 's':
246          gMinimumLogSeverity = FATAL;
247          continue;
248      }
249    }
250    LOG(FATAL) << "unsupported '" << spec << "' in ANDROID_LOG_TAGS (" << tags
251               << ")";
252  }
253}
254
255void SetLogger(LogFunction&& logger) {
256  lock_guard<mutex> lock(logging_lock);
257  gLogger = std::move(logger);
258}
259
260// This indirection greatly reduces the stack impact of having lots of
261// checks/logging in a function.
262class LogMessageData {
263 public:
264  LogMessageData(const char* file, unsigned int line, LogId id,
265                 LogSeverity severity, int error)
266      : file_(file),
267        line_number_(line),
268        id_(id),
269        severity_(severity),
270        error_(error) {
271    const char* last_slash = strrchr(file, '/');
272    file = (last_slash == nullptr) ? file : last_slash + 1;
273  }
274
275  const char* GetFile() const {
276    return file_;
277  }
278
279  unsigned int GetLineNumber() const {
280    return line_number_;
281  }
282
283  LogSeverity GetSeverity() const {
284    return severity_;
285  }
286
287  LogId GetId() const {
288    return id_;
289  }
290
291  int GetError() const {
292    return error_;
293  }
294
295  std::ostream& GetBuffer() {
296    return buffer_;
297  }
298
299  std::string ToString() const {
300    return buffer_.str();
301  }
302
303 private:
304  std::ostringstream buffer_;
305  const char* const file_;
306  const unsigned int line_number_;
307  const LogId id_;
308  const LogSeverity severity_;
309  const int error_;
310
311  DISALLOW_COPY_AND_ASSIGN(LogMessageData);
312};
313
314LogMessage::LogMessage(const char* file, unsigned int line, LogId id,
315                       LogSeverity severity, int error)
316    : data_(new LogMessageData(file, line, id, severity, error)) {
317}
318
319LogMessage::~LogMessage() {
320  if (data_->GetSeverity() < gMinimumLogSeverity) {
321    return;  // No need to format something we're not going to output.
322  }
323
324  // Finish constructing the message.
325  if (data_->GetError() != -1) {
326    data_->GetBuffer() << ": " << strerror(data_->GetError());
327  }
328  std::string msg(data_->ToString());
329
330  if (msg.find('\n') == std::string::npos) {
331    LogLine(data_->GetFile(), data_->GetLineNumber(), data_->GetId(),
332            data_->GetSeverity(), msg.c_str());
333  } else {
334    msg += '\n';
335    size_t i = 0;
336    while (i < msg.size()) {
337      size_t nl = msg.find('\n', i);
338      msg[nl] = '\0';
339      LogLine(data_->GetFile(), data_->GetLineNumber(), data_->GetId(),
340              data_->GetSeverity(), &msg[i]);
341      i = nl + 1;
342    }
343  }
344
345  // Abort if necessary.
346  if (data_->GetSeverity() == FATAL) {
347#ifdef __ANDROID__
348    android_set_abort_message(msg.c_str());
349#endif
350    abort();
351  }
352}
353
354std::ostream& LogMessage::stream() {
355  return data_->GetBuffer();
356}
357
358void LogMessage::LogLine(const char* file, unsigned int line, LogId id,
359                         LogSeverity severity, const char* message) {
360  const char* tag = ProgramInvocationName();
361  lock_guard<mutex> lock(logging_lock);
362  gLogger(id, severity, tag, file, line, message);
363}
364
365ScopedLogSeverity::ScopedLogSeverity(LogSeverity level) {
366  old_ = gMinimumLogSeverity;
367  gMinimumLogSeverity = level;
368}
369
370ScopedLogSeverity::~ScopedLogSeverity() {
371  gMinimumLogSeverity = old_;
372}
373
374}  // namespace base
375}  // namespace android
376