logging.cpp revision 5c19040b06b5bb61731e24ea6777c237dc23145d 
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#include "base/logging.h"
18
19#include <libgen.h>
20
21// For getprogname(3) or program_invocation_short_name.
22#if defined(__ANDROID__) || defined(__APPLE__)
23#include <stdlib.h>
24#elif defined(__GLIBC__)
25#include <errno.h>
26#endif
27
28#include <iostream>
29#include <limits>
30#include <sstream>
31#include <string>
32#include <utility>
33#include <vector>
34
35#ifndef _WIN32
36#include <mutex>
37#else
38#define NOGDI // Suppress the evil ERROR macro.
39#include <windows.h>
40#endif
41
42#include "base/macros.h"
43#include "base/strings.h"
44#include "cutils/threads.h"
45
46// Headers for LogMessage::LogLine.
47#ifdef __ANDROID__
48#include <android/set_abort_message.h>
49#include "cutils/log.h"
50#else
51#include <sys/types.h>
52#include <unistd.h>
53#endif
54
55namespace {
56#ifndef _WIN32
57using std::mutex;
58using std::lock_guard;
59
60#if defined(__GLIBC__)
61const char* getprogname() {
62  return program_invocation_short_name;
63}
64#endif
65
66#else
67const char* getprogname() {
68  static bool first = true;
69  static char progname[MAX_PATH] = {};
70
71  if (first) {
72    // TODO(danalbert): This is a full path on Windows. Just get the basename.
73    DWORD nchars = GetModuleFileName(nullptr, progname, sizeof(progname));
74    DCHECK_GT(nchars, 0U);
75    first = false;
76  }
77
78  return progname;
79}
80
81class mutex {
82 public:
83  mutex() {
84    semaphore_ = CreateSemaphore(nullptr, 1, 1, nullptr);
85    CHECK(semaphore_ != nullptr) << "Failed to create Mutex";
86  }
87  ~mutex() {
88    CloseHandle(semaphore_);
89  }
90
91  void lock() {
92    DWORD result = WaitForSingleObject(semaphore_, INFINITE);
93    CHECK_EQ(result, WAIT_OBJECT_0) << GetLastError();
94  }
95
96  void unlock() {
97    bool result = ReleaseSemaphore(semaphore_, 1, nullptr);
98    CHECK(result);
99  }
100
101 private:
102  HANDLE semaphore_;
103};
104
105template <typename LockT>
106class lock_guard {
107 public:
108  explicit lock_guard(LockT& lock) : lock_(lock) {
109    lock_.lock();
110  }
111
112  ~lock_guard() {
113    lock_.unlock();
114  }
115
116 private:
117  LockT& lock_;
118
119  DISALLOW_COPY_AND_ASSIGN(lock_guard);
120};
121#endif
122} // namespace
123
124namespace android {
125namespace base {
126
127static mutex logging_lock;
128
129#ifdef __ANDROID__
130static LogFunction gLogger = LogdLogger();
131#else
132static LogFunction gLogger = StderrLogger;
133#endif
134
135static bool gInitialized = false;
136static LogSeverity gMinimumLogSeverity = INFO;
137static std::unique_ptr<std::string> gProgramInvocationName;
138
139static const char* ProgramInvocationName() {
140  if (gProgramInvocationName == nullptr) {
141    gProgramInvocationName.reset(new std::string(getprogname()));
142  }
143
144  return gProgramInvocationName->c_str();
145}
146
147void StderrLogger(LogId, LogSeverity severity, const char*, const char* file,
148                  unsigned int line, const char* message) {
149  static const char* log_characters = "VDIWEF";
150  CHECK_EQ(strlen(log_characters), FATAL + 1U);
151  char severity_char = log_characters[severity];
152  fprintf(stderr, "%s %c %5d %5d %s:%u] %s\n", ProgramInvocationName(),
153          severity_char, getpid(), gettid(), file, line, message);
154}
155
156
157#ifdef __ANDROID__
158LogdLogger::LogdLogger(LogId default_log_id) : default_log_id_(default_log_id) {
159}
160
161static const android_LogPriority kLogSeverityToAndroidLogPriority[] = {
162    ANDROID_LOG_VERBOSE, ANDROID_LOG_DEBUG, ANDROID_LOG_INFO,
163    ANDROID_LOG_WARN,    ANDROID_LOG_ERROR, ANDROID_LOG_FATAL,
164};
165static_assert(arraysize(kLogSeverityToAndroidLogPriority) == FATAL + 1,
166              "Mismatch in size of kLogSeverityToAndroidLogPriority and values "
167              "in LogSeverity");
168
169static const log_id kLogIdToAndroidLogId[] = {
170    LOG_ID_MAX, LOG_ID_MAIN, LOG_ID_SYSTEM,
171};
172static_assert(arraysize(kLogIdToAndroidLogId) == SYSTEM + 1,
173              "Mismatch in size of kLogIdToAndroidLogId and values in LogId");
174
175void LogdLogger::operator()(LogId id, LogSeverity severity, const char* tag,
176                            const char* file, unsigned int line,
177                            const char* message) {
178  int priority = kLogSeverityToAndroidLogPriority[severity];
179  if (id == DEFAULT) {
180    id = default_log_id_;
181  }
182
183  log_id lg_id = kLogIdToAndroidLogId[id];
184
185  if (priority == ANDROID_LOG_FATAL) {
186    __android_log_buf_print(lg_id, priority, tag, "%s:%u] %s", file, line,
187                            message);
188  } else {
189    __android_log_buf_print(lg_id, priority, tag, "%s", message);
190  }
191}
192#endif
193
194void InitLogging(char* argv[], LogFunction&& logger) {
195  SetLogger(std::forward<LogFunction>(logger));
196  InitLogging(argv);
197}
198
199void InitLogging(char* argv[]) {
200  if (gInitialized) {
201    return;
202  }
203
204  gInitialized = true;
205
206  // Stash the command line for later use. We can use /proc/self/cmdline on
207  // Linux to recover this, but we don't have that luxury on the Mac, and there
208  // are a couple of argv[0] variants that are commonly used.
209  if (argv != nullptr) {
210    gProgramInvocationName.reset(new std::string(basename(argv[0])));
211  }
212
213  const char* tags = getenv("ANDROID_LOG_TAGS");
214  if (tags == nullptr) {
215    return;
216  }
217
218  std::vector<std::string> specs = Split(tags, " ");
219  for (size_t i = 0; i < specs.size(); ++i) {
220    // "tag-pattern:[vdiwefs]"
221    std::string spec(specs[i]);
222    if (spec.size() == 3 && StartsWith(spec, "*:")) {
223      switch (spec[2]) {
224        case 'v':
225          gMinimumLogSeverity = VERBOSE;
226          continue;
227        case 'd':
228          gMinimumLogSeverity = DEBUG;
229          continue;
230        case 'i':
231          gMinimumLogSeverity = INFO;
232          continue;
233        case 'w':
234          gMinimumLogSeverity = WARNING;
235          continue;
236        case 'e':
237          gMinimumLogSeverity = ERROR;
238          continue;
239        case 'f':
240          gMinimumLogSeverity = FATAL;
241          continue;
242        // liblog will even suppress FATAL if you say 's' for silent, but that's
243        // crazy!
244        case 's':
245          gMinimumLogSeverity = FATAL;
246          continue;
247      }
248    }
249    LOG(FATAL) << "unsupported '" << spec << "' in ANDROID_LOG_TAGS (" << tags
250               << ")";
251  }
252}
253
254void SetLogger(LogFunction&& logger) {
255  lock_guard<mutex> lock(logging_lock);
256  gLogger = std::move(logger);
257}
258
259// This indirection greatly reduces the stack impact of having lots of
260// checks/logging in a function.
261class LogMessageData {
262 public:
263  LogMessageData(const char* file, unsigned int line, LogId id,
264                 LogSeverity severity, int error)
265      : file_(file),
266        line_number_(line),
267        id_(id),
268        severity_(severity),
269        error_(error) {
270    const char* last_slash = strrchr(file, '/');
271    file = (last_slash == nullptr) ? file : last_slash + 1;
272  }
273
274  const char* GetFile() const {
275    return file_;
276  }
277
278  unsigned int GetLineNumber() const {
279    return line_number_;
280  }
281
282  LogSeverity GetSeverity() const {
283    return severity_;
284  }
285
286  LogId GetId() const {
287    return id_;
288  }
289
290  int GetError() const {
291    return error_;
292  }
293
294  std::ostream& GetBuffer() {
295    return buffer_;
296  }
297
298  std::string ToString() const {
299    return buffer_.str();
300  }
301
302 private:
303  std::ostringstream buffer_;
304  const char* const file_;
305  const unsigned int line_number_;
306  const LogId id_;
307  const LogSeverity severity_;
308  const int error_;
309
310  DISALLOW_COPY_AND_ASSIGN(LogMessageData);
311};
312
313LogMessage::LogMessage(const char* file, unsigned int line, LogId id,
314                       LogSeverity severity, int error)
315    : data_(new LogMessageData(file, line, id, severity, error)) {
316}
317
318LogMessage::~LogMessage() {
319  if (data_->GetSeverity() < gMinimumLogSeverity) {
320    return;  // No need to format something we're not going to output.
321  }
322
323  // Finish constructing the message.
324  if (data_->GetError() != -1) {
325    data_->GetBuffer() << ": " << strerror(data_->GetError());
326  }
327  std::string msg(data_->ToString());
328
329  if (msg.find('\n') == std::string::npos) {
330    LogLine(data_->GetFile(), data_->GetLineNumber(), data_->GetId(),
331            data_->GetSeverity(), msg.c_str());
332  } else {
333    msg += '\n';
334    size_t i = 0;
335    while (i < msg.size()) {
336      size_t nl = msg.find('\n', i);
337      msg[nl] = '\0';
338      LogLine(data_->GetFile(), data_->GetLineNumber(), data_->GetId(),
339              data_->GetSeverity(), &msg[i]);
340      i = nl + 1;
341    }
342  }
343
344  // Abort if necessary.
345  if (data_->GetSeverity() == FATAL) {
346#ifdef __ANDROID__
347    android_set_abort_message(msg.c_str());
348#endif
349    abort();
350  }
351}
352
353std::ostream& LogMessage::stream() {
354  return data_->GetBuffer();
355}
356
357void LogMessage::LogLine(const char* file, unsigned int line, LogId id,
358                         LogSeverity severity, const char* message) {
359  const char* tag = ProgramInvocationName();
360  lock_guard<mutex> lock(logging_lock);
361  gLogger(id, severity, tag, file, line, message);
362}
363
364ScopedLogSeverity::ScopedLogSeverity(LogSeverity level) {
365  old_ = gMinimumLogSeverity;
366  gMinimumLogSeverity = level;
367}
368
369ScopedLogSeverity::~ScopedLogSeverity() {
370  gMinimumLogSeverity = old_;
371}
372
373}  // namespace base
374}  // namespace android
375