logging.cpp revision bdab59a8613c732df5d746328ff2268be8da13ab 
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
142static const char* ProgramInvocationName() {
143  if (gProgramInvocationName == nullptr) {
144    gProgramInvocationName.reset(new std::string(getprogname()));
145  }
146
147  return gProgramInvocationName->c_str();
148}
149
150void StderrLogger(LogId, LogSeverity severity, const char*, const char* file,
151                  unsigned int line, const char* message) {
152  static const char log_characters[] = "VDIWEF";
153  static_assert(arraysize(log_characters) - 1 == FATAL + 1,
154                "Mismatch in size of log_characters and values in LogSeverity");
155  char severity_char = log_characters[severity];
156  fprintf(stderr, "%s %c %5d %5d %s:%u] %s\n", ProgramInvocationName(),
157          severity_char, getpid(), gettid(), file, line, message);
158}
159
160
161#ifdef __ANDROID__
162LogdLogger::LogdLogger(LogId default_log_id) : default_log_id_(default_log_id) {
163}
164
165static const android_LogPriority kLogSeverityToAndroidLogPriority[] = {
166    ANDROID_LOG_VERBOSE, ANDROID_LOG_DEBUG, ANDROID_LOG_INFO,
167    ANDROID_LOG_WARN,    ANDROID_LOG_ERROR, ANDROID_LOG_FATAL,
168};
169static_assert(arraysize(kLogSeverityToAndroidLogPriority) == FATAL + 1,
170              "Mismatch in size of kLogSeverityToAndroidLogPriority and values "
171              "in LogSeverity");
172
173static const log_id kLogIdToAndroidLogId[] = {
174    LOG_ID_MAX, LOG_ID_MAIN, LOG_ID_SYSTEM,
175};
176static_assert(arraysize(kLogIdToAndroidLogId) == SYSTEM + 1,
177              "Mismatch in size of kLogIdToAndroidLogId and values in LogId");
178
179void LogdLogger::operator()(LogId id, LogSeverity severity, const char* tag,
180                            const char* file, unsigned int line,
181                            const char* message) {
182  int priority = kLogSeverityToAndroidLogPriority[severity];
183  if (id == DEFAULT) {
184    id = default_log_id_;
185  }
186
187  log_id lg_id = kLogIdToAndroidLogId[id];
188
189  if (priority == ANDROID_LOG_FATAL) {
190    __android_log_buf_print(lg_id, priority, tag, "%s:%u] %s", file, line,
191                            message);
192  } else {
193    __android_log_buf_print(lg_id, priority, tag, "%s", message);
194  }
195}
196#endif
197
198void InitLogging(char* argv[], LogFunction&& logger) {
199  SetLogger(std::forward<LogFunction>(logger));
200  InitLogging(argv);
201}
202
203// TODO: make this public; it's independently useful.
204class ErrnoRestorer {
205 public:
206  ErrnoRestorer(int saved_errno) : saved_errno_(saved_errno) {
207  }
208
209  ~ErrnoRestorer() {
210    errno = saved_errno_;
211  }
212
213 private:
214  const int saved_errno_;
215};
216
217void InitLogging(char* argv[]) {
218  if (gInitialized) {
219    return;
220  }
221
222  gInitialized = true;
223
224  // Stash the command line for later use. We can use /proc/self/cmdline on
225  // Linux to recover this, but we don't have that luxury on the Mac, and there
226  // are a couple of argv[0] variants that are commonly used.
227  if (argv != nullptr) {
228    gProgramInvocationName.reset(new std::string(basename(argv[0])));
229  }
230
231  const char* tags = getenv("ANDROID_LOG_TAGS");
232  if (tags == nullptr) {
233    return;
234  }
235
236  std::vector<std::string> specs = Split(tags, " ");
237  for (size_t i = 0; i < specs.size(); ++i) {
238    // "tag-pattern:[vdiwefs]"
239    std::string spec(specs[i]);
240    if (spec.size() == 3 && StartsWith(spec, "*:")) {
241      switch (spec[2]) {
242        case 'v':
243          gMinimumLogSeverity = VERBOSE;
244          continue;
245        case 'd':
246          gMinimumLogSeverity = DEBUG;
247          continue;
248        case 'i':
249          gMinimumLogSeverity = INFO;
250          continue;
251        case 'w':
252          gMinimumLogSeverity = WARNING;
253          continue;
254        case 'e':
255          gMinimumLogSeverity = ERROR;
256          continue;
257        case 'f':
258          gMinimumLogSeverity = FATAL;
259          continue;
260        // liblog will even suppress FATAL if you say 's' for silent, but that's
261        // crazy!
262        case 's':
263          gMinimumLogSeverity = FATAL;
264          continue;
265      }
266    }
267    LOG(FATAL) << "unsupported '" << spec << "' in ANDROID_LOG_TAGS (" << tags
268               << ")";
269  }
270}
271
272void SetLogger(LogFunction&& logger) {
273  lock_guard<mutex> lock(logging_lock);
274  gLogger = std::move(logger);
275}
276
277// We can't use basename(3) because this code runs on the Mac, which doesn't
278// have a non-modifying basename.
279static const char* GetFileBasename(const char* file) {
280  const char* last_slash = strrchr(file, '/');
281  return (last_slash == nullptr) ? file : last_slash + 1;
282}
283
284// This indirection greatly reduces the stack impact of having lots of
285// checks/logging in a function.
286class LogMessageData {
287 public:
288  LogMessageData(const char* file, unsigned int line, LogId id,
289                 LogSeverity severity, int error, int saved_errno)
290      : file_(GetFileBasename(file)),
291        line_number_(line),
292        id_(id),
293        severity_(severity),
294        error_(error),
295        errno_restorer_(saved_errno) {
296  }
297
298  const char* GetFile() const {
299    return file_;
300  }
301
302  unsigned int GetLineNumber() const {
303    return line_number_;
304  }
305
306  LogSeverity GetSeverity() const {
307    return severity_;
308  }
309
310  LogId GetId() const {
311    return id_;
312  }
313
314  int GetError() const {
315    return error_;
316  }
317
318  std::ostream& GetBuffer() {
319    return buffer_;
320  }
321
322  std::string ToString() const {
323    return buffer_.str();
324  }
325
326 private:
327  std::ostringstream buffer_;
328  const char* const file_;
329  const unsigned int line_number_;
330  const LogId id_;
331  const LogSeverity severity_;
332  const int error_;
333  ErrnoRestorer errno_restorer_;
334
335  DISALLOW_COPY_AND_ASSIGN(LogMessageData);
336};
337
338LogMessage::LogMessage(const char* file, unsigned int line, LogId id,
339                       LogSeverity severity, int error)
340    : data_(new LogMessageData(file, line, id, severity, error, errno)) {
341}
342
343LogMessage::~LogMessage() {
344  if (data_->GetSeverity() < gMinimumLogSeverity) {
345    return;  // No need to format something we're not going to output.
346  }
347
348  // Finish constructing the message.
349  if (data_->GetError() != -1) {
350    data_->GetBuffer() << ": " << strerror(data_->GetError());
351  }
352  std::string msg(data_->ToString());
353
354  if (msg.find('\n') == std::string::npos) {
355    LogLine(data_->GetFile(), data_->GetLineNumber(), data_->GetId(),
356            data_->GetSeverity(), msg.c_str());
357  } else {
358    msg += '\n';
359    size_t i = 0;
360    while (i < msg.size()) {
361      size_t nl = msg.find('\n', i);
362      msg[nl] = '\0';
363      LogLine(data_->GetFile(), data_->GetLineNumber(), data_->GetId(),
364              data_->GetSeverity(), &msg[i]);
365      i = nl + 1;
366    }
367  }
368
369  // Abort if necessary.
370  if (data_->GetSeverity() == FATAL) {
371#ifdef __ANDROID__
372    android_set_abort_message(msg.c_str());
373#endif
374    abort();
375  }
376}
377
378std::ostream& LogMessage::stream() {
379  return data_->GetBuffer();
380}
381
382void LogMessage::LogLine(const char* file, unsigned int line, LogId id,
383                         LogSeverity severity, const char* message) {
384  const char* tag = ProgramInvocationName();
385  lock_guard<mutex> lock(logging_lock);
386  gLogger(id, severity, tag, file, line, message);
387}
388
389ScopedLogSeverity::ScopedLogSeverity(LogSeverity level) {
390  old_ = gMinimumLogSeverity;
391  gMinimumLogSeverity = level;
392}
393
394ScopedLogSeverity::~ScopedLogSeverity() {
395  gMinimumLogSeverity = old_;
396}
397
398}  // namespace base
399}  // namespace android
400