logging.cpp revision 765ae6bcfc62148de629f68315fdf8cd1bc35342 
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    CHAR longname[MAX_PATH];
74    DWORD nchars = GetModuleFileNameA(nullptr, longname, arraysize(longname));
75    if ((nchars >= arraysize(longname)) || (nchars == 0)) {
76      // String truncation or some other error.
77      strcpy(progname, "<unknown>");
78    } else {
79      strcpy(progname, basename(longname));
80    }
81    first = false;
82  }
83
84  return progname;
85}
86
87class mutex {
88 public:
89  mutex() {
90    InitializeCriticalSection(&critical_section_);
91  }
92  ~mutex() {
93    DeleteCriticalSection(&critical_section_);
94  }
95
96  void lock() {
97    EnterCriticalSection(&critical_section_);
98  }
99
100  void unlock() {
101    LeaveCriticalSection(&critical_section_);
102  }
103
104 private:
105  CRITICAL_SECTION critical_section_;
106};
107
108template <typename LockT>
109class lock_guard {
110 public:
111  explicit lock_guard(LockT& lock) : lock_(lock) {
112    lock_.lock();
113  }
114
115  ~lock_guard() {
116    lock_.unlock();
117  }
118
119 private:
120  LockT& lock_;
121
122  DISALLOW_COPY_AND_ASSIGN(lock_guard);
123};
124#endif
125} // namespace
126
127namespace android {
128namespace base {
129
130static mutex logging_lock;
131
132#ifdef __ANDROID__
133static LogFunction gLogger = LogdLogger();
134#else
135static LogFunction gLogger = StderrLogger;
136#endif
137
138static bool gInitialized = false;
139static LogSeverity gMinimumLogSeverity = INFO;
140static std::unique_ptr<std::string> gProgramInvocationName;
141
142LogSeverity GetMinimumLogSeverity() {
143  return gMinimumLogSeverity;
144}
145
146static const char* ProgramInvocationName() {
147  if (gProgramInvocationName == nullptr) {
148    gProgramInvocationName.reset(new std::string(getprogname()));
149  }
150
151  return gProgramInvocationName->c_str();
152}
153
154void StderrLogger(LogId, LogSeverity severity, const char*, const char* file,
155                  unsigned int line, const char* message) {
156  static const char log_characters[] = "VDIWEF";
157  static_assert(arraysize(log_characters) - 1 == FATAL + 1,
158                "Mismatch in size of log_characters and values in LogSeverity");
159  char severity_char = log_characters[severity];
160  fprintf(stderr, "%s %c %5d %5d %s:%u] %s\n", ProgramInvocationName(),
161          severity_char, getpid(), gettid(), file, line, message);
162}
163
164
165#ifdef __ANDROID__
166LogdLogger::LogdLogger(LogId default_log_id) : default_log_id_(default_log_id) {
167}
168
169static const android_LogPriority kLogSeverityToAndroidLogPriority[] = {
170    ANDROID_LOG_VERBOSE, ANDROID_LOG_DEBUG, ANDROID_LOG_INFO,
171    ANDROID_LOG_WARN,    ANDROID_LOG_ERROR, ANDROID_LOG_FATAL,
172};
173static_assert(arraysize(kLogSeverityToAndroidLogPriority) == FATAL + 1,
174              "Mismatch in size of kLogSeverityToAndroidLogPriority and values "
175              "in LogSeverity");
176
177static const log_id kLogIdToAndroidLogId[] = {
178    LOG_ID_MAX, LOG_ID_MAIN, LOG_ID_SYSTEM,
179};
180static_assert(arraysize(kLogIdToAndroidLogId) == SYSTEM + 1,
181              "Mismatch in size of kLogIdToAndroidLogId and values in LogId");
182
183void LogdLogger::operator()(LogId id, LogSeverity severity, const char* tag,
184                            const char* file, unsigned int line,
185                            const char* message) {
186  int priority = kLogSeverityToAndroidLogPriority[severity];
187  if (id == DEFAULT) {
188    id = default_log_id_;
189  }
190
191  log_id lg_id = kLogIdToAndroidLogId[id];
192
193  if (priority == ANDROID_LOG_FATAL) {
194    __android_log_buf_print(lg_id, priority, tag, "%s:%u] %s", file, line,
195                            message);
196  } else {
197    __android_log_buf_print(lg_id, priority, tag, "%s", message);
198  }
199}
200#endif
201
202void InitLogging(char* argv[], LogFunction&& logger) {
203  SetLogger(std::forward<LogFunction>(logger));
204  InitLogging(argv);
205}
206
207void InitLogging(char* argv[]) {
208  if (gInitialized) {
209    return;
210  }
211
212  gInitialized = true;
213
214  // Stash the command line for later use. We can use /proc/self/cmdline on
215  // Linux to recover this, but we don't have that luxury on the Mac, and there
216  // are a couple of argv[0] variants that are commonly used.
217  if (argv != nullptr) {
218    gProgramInvocationName.reset(new std::string(basename(argv[0])));
219  }
220
221  const char* tags = getenv("ANDROID_LOG_TAGS");
222  if (tags == nullptr) {
223    return;
224  }
225
226  std::vector<std::string> specs = Split(tags, " ");
227  for (size_t i = 0; i < specs.size(); ++i) {
228    // "tag-pattern:[vdiwefs]"
229    std::string spec(specs[i]);
230    if (spec.size() == 3 && StartsWith(spec, "*:")) {
231      switch (spec[2]) {
232        case 'v':
233          gMinimumLogSeverity = VERBOSE;
234          continue;
235        case 'd':
236          gMinimumLogSeverity = DEBUG;
237          continue;
238        case 'i':
239          gMinimumLogSeverity = INFO;
240          continue;
241        case 'w':
242          gMinimumLogSeverity = WARNING;
243          continue;
244        case 'e':
245          gMinimumLogSeverity = ERROR;
246          continue;
247        case 'f':
248          gMinimumLogSeverity = FATAL;
249          continue;
250        // liblog will even suppress FATAL if you say 's' for silent, but that's
251        // crazy!
252        case 's':
253          gMinimumLogSeverity = FATAL;
254          continue;
255      }
256    }
257    LOG(FATAL) << "unsupported '" << spec << "' in ANDROID_LOG_TAGS (" << tags
258               << ")";
259  }
260}
261
262void SetLogger(LogFunction&& logger) {
263  lock_guard<mutex> lock(logging_lock);
264  gLogger = std::move(logger);
265}
266
267// We can't use basename(3) because this code runs on the Mac, which doesn't
268// have a non-modifying basename.
269static const char* GetFileBasename(const char* file) {
270  const char* last_slash = strrchr(file, '/');
271  return (last_slash == nullptr) ? file : last_slash + 1;
272}
273
274// This indirection greatly reduces the stack impact of having lots of
275// checks/logging in a function.
276class LogMessageData {
277 public:
278  LogMessageData(const char* file, unsigned int line, LogId id,
279                 LogSeverity severity, int error)
280      : file_(GetFileBasename(file)),
281        line_number_(line),
282        id_(id),
283        severity_(severity),
284        error_(error) {
285  }
286
287  const char* GetFile() const {
288    return file_;
289  }
290
291  unsigned int GetLineNumber() const {
292    return line_number_;
293  }
294
295  LogSeverity GetSeverity() const {
296    return severity_;
297  }
298
299  LogId GetId() const {
300    return id_;
301  }
302
303  int GetError() const {
304    return error_;
305  }
306
307  std::ostream& GetBuffer() {
308    return buffer_;
309  }
310
311  std::string ToString() const {
312    return buffer_.str();
313  }
314
315 private:
316  std::ostringstream buffer_;
317  const char* const file_;
318  const unsigned int line_number_;
319  const LogId id_;
320  const LogSeverity severity_;
321  const int error_;
322
323  DISALLOW_COPY_AND_ASSIGN(LogMessageData);
324};
325
326LogMessage::LogMessage(const char* file, unsigned int line, LogId id,
327                       LogSeverity severity, int error)
328    : data_(new LogMessageData(file, line, id, severity, error)) {
329}
330
331LogMessage::~LogMessage() {
332  // Finish constructing the message.
333  if (data_->GetError() != -1) {
334    data_->GetBuffer() << ": " << strerror(data_->GetError());
335  }
336  std::string msg(data_->ToString());
337
338  {
339    // Do the actual logging with the lock held.
340    lock_guard<mutex> lock(logging_lock);
341    if (msg.find('\n') == std::string::npos) {
342      LogLine(data_->GetFile(), data_->GetLineNumber(), data_->GetId(),
343              data_->GetSeverity(), msg.c_str());
344    } else {
345      msg += '\n';
346      size_t i = 0;
347      while (i < msg.size()) {
348        size_t nl = msg.find('\n', i);
349        msg[nl] = '\0';
350        LogLine(data_->GetFile(), data_->GetLineNumber(), data_->GetId(),
351                data_->GetSeverity(), &msg[i]);
352        i = nl + 1;
353      }
354    }
355  }
356
357  // Abort if necessary.
358  if (data_->GetSeverity() == FATAL) {
359#ifdef __ANDROID__
360    android_set_abort_message(msg.c_str());
361#endif
362    abort();
363  }
364}
365
366std::ostream& LogMessage::stream() {
367  return data_->GetBuffer();
368}
369
370void LogMessage::LogLine(const char* file, unsigned int line, LogId id,
371                         LogSeverity severity, const char* message) {
372  const char* tag = ProgramInvocationName();
373  gLogger(id, severity, tag, file, line, message);
374}
375
376ScopedLogSeverity::ScopedLogSeverity(LogSeverity level) {
377  old_ = gMinimumLogSeverity;
378  gMinimumLogSeverity = level;
379}
380
381ScopedLogSeverity::~ScopedLogSeverity() {
382  gMinimumLogSeverity = old_;
383}
384
385}  // namespace base
386}  // namespace android
387