logging.cpp revision 47328c96d91ca71b57b8976df2df1fe51579a955 
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 <iostream>
20#include <limits>
21#include <sstream>
22#include <string>
23#include <vector>
24
25#include "base/strings.h"
26
27// Headers for LogMessage::LogLine.
28#ifdef __ANDROID__
29#include <android/set_abort_message.h>
30#include "cutils/log.h"
31#else
32#include <sys/types.h>
33#include <unistd.h>
34#endif
35
36// For GetTid.
37#if defined(__APPLE__)
38#include "AvailabilityMacros.h"  // For MAC_OS_X_VERSION_MAX_ALLOWED
39#include <sys/syscall.h>
40#include <sys/time.h>
41#elif !defined(__BIONIC__)
42#include <syscall.h>
43#endif
44
45namespace android {
46namespace base {
47
48static std::mutex logging_lock;
49
50static LogSeverity gMinimumLogSeverity = INFO;
51static std::unique_ptr<std::string> gCmdLine;
52static std::unique_ptr<std::string> gProgramInvocationName;
53static std::unique_ptr<std::string> gProgramInvocationShortName;
54
55#ifndef __ANDROID__
56static pid_t GetTid() {
57#if defined(__APPLE__)
58  uint64_t owner;
59  // Requires Mac OS 10.6
60  CHECK_PTHREAD_CALL(pthread_threadid_np, (NULL, &owner), __FUNCTION__);
61  return owner;
62#else
63  return syscall(__NR_gettid);
64#endif
65}
66#endif  // __ANDROID__
67
68const char* GetCmdLine() {
69  return (gCmdLine.get() != nullptr) ? gCmdLine->c_str() : nullptr;
70}
71
72const char* ProgramInvocationName() {
73  return (gProgramInvocationName.get() != nullptr)
74             ? gProgramInvocationName->c_str()
75             : "unknown";
76}
77
78const char* ProgramInvocationShortName() {
79  return (gProgramInvocationShortName.get() != nullptr)
80             ? gProgramInvocationShortName->c_str()
81             : "unknown";
82}
83
84void InitLogging(char* argv[]) {
85  if (gCmdLine.get() != nullptr) {
86    return;
87  }
88
89  // Stash the command line for later use. We can use /proc/self/cmdline on
90  // Linux to recover this, but we don't have that luxury on the Mac, and there
91  // are a couple of argv[0] variants that are commonly used.
92  if (argv != nullptr) {
93    gCmdLine.reset(new std::string(argv[0]));
94    for (size_t i = 1; argv[i] != nullptr; ++i) {
95      gCmdLine->append(" ");
96      gCmdLine->append(argv[i]);
97    }
98    gProgramInvocationName.reset(new std::string(argv[0]));
99    const char* last_slash = strrchr(argv[0], '/');
100    gProgramInvocationShortName.reset(
101        new std::string((last_slash != nullptr) ? last_slash + 1 : argv[0]));
102  } else {
103    // TODO: fall back to /proc/self/cmdline when argv is NULL on Linux.
104    gCmdLine.reset(new std::string("<unset>"));
105  }
106  const char* tags = getenv("ANDROID_LOG_TAGS");
107  if (tags == nullptr) {
108    return;
109  }
110
111  std::vector<std::string> specs = Split(tags, " ");
112  for (size_t i = 0; i < specs.size(); ++i) {
113    // "tag-pattern:[vdiwefs]"
114    std::string spec(specs[i]);
115    if (spec.size() == 3 && StartsWith(spec, "*:")) {
116      switch (spec[2]) {
117        case 'v':
118          gMinimumLogSeverity = VERBOSE;
119          continue;
120        case 'd':
121          gMinimumLogSeverity = DEBUG;
122          continue;
123        case 'i':
124          gMinimumLogSeverity = INFO;
125          continue;
126        case 'w':
127          gMinimumLogSeverity = WARNING;
128          continue;
129        case 'e':
130          gMinimumLogSeverity = ERROR;
131          continue;
132        case 'f':
133          gMinimumLogSeverity = FATAL;
134          continue;
135        // liblog will even suppress FATAL if you say 's' for silent, but that's
136        // crazy!
137        case 's':
138          gMinimumLogSeverity = FATAL;
139          continue;
140      }
141    }
142    LOG(FATAL) << "unsupported '" << spec << "' in ANDROID_LOG_TAGS (" << tags
143               << ")";
144  }
145}
146
147// This indirection greatly reduces the stack impact of having lots of
148// checks/logging in a function.
149class LogMessageData {
150 public:
151  LogMessageData(const char* file, unsigned int line, LogSeverity severity,
152                 int error)
153      : file_(file), line_number_(line), severity_(severity), error_(error) {
154    const char* last_slash = strrchr(file, '/');
155    file = (last_slash == nullptr) ? file : last_slash + 1;
156  }
157
158  const char* GetFile() const {
159    return file_;
160  }
161
162  unsigned int GetLineNumber() const {
163    return line_number_;
164  }
165
166  LogSeverity GetSeverity() const {
167    return severity_;
168  }
169
170  int GetError() const {
171    return error_;
172  }
173
174  std::ostream& GetBuffer() {
175    return buffer_;
176  }
177
178  std::string ToString() const {
179    return buffer_.str();
180  }
181
182 private:
183  std::ostringstream buffer_;
184  const char* const file_;
185  const unsigned int line_number_;
186  const LogSeverity severity_;
187  const int error_;
188
189  DISALLOW_COPY_AND_ASSIGN(LogMessageData);
190};
191
192LogMessage::LogMessage(const char* file, unsigned int line,
193                       LogSeverity severity, int error)
194    : data_(new LogMessageData(file, line, severity, error)) {
195}
196
197LogMessage::~LogMessage() {
198  if (data_->GetSeverity() < gMinimumLogSeverity) {
199    return;  // No need to format something we're not going to output.
200  }
201
202  // Finish constructing the message.
203  if (data_->GetError() != -1) {
204    data_->GetBuffer() << ": " << strerror(data_->GetError());
205  }
206  std::string msg(data_->ToString());
207
208  // Do the actual logging with the lock held.
209  {
210    std::lock_guard<std::mutex> lock(logging_lock);
211    if (msg.find('\n') == std::string::npos) {
212      LogLine(data_->GetFile(), data_->GetLineNumber(), data_->GetSeverity(),
213              msg.c_str());
214    } else {
215      msg += '\n';
216      size_t i = 0;
217      while (i < msg.size()) {
218        size_t nl = msg.find('\n', i);
219        msg[nl] = '\0';
220        LogLine(data_->GetFile(), data_->GetLineNumber(), data_->GetSeverity(),
221                &msg[i]);
222        i = nl + 1;
223      }
224    }
225  }
226
227  // Abort if necessary.
228  if (data_->GetSeverity() == FATAL) {
229#ifdef __ANDROID__
230    android_set_abort_message(msg.c_str());
231#endif
232    abort();
233  }
234}
235
236std::ostream& LogMessage::stream() {
237  return data_->GetBuffer();
238}
239
240#ifdef __ANDROID__
241static const android_LogPriority kLogSeverityToAndroidLogPriority[] = {
242    ANDROID_LOG_VERBOSE, ANDROID_LOG_DEBUG, ANDROID_LOG_INFO,
243    ANDROID_LOG_WARN,    ANDROID_LOG_ERROR, ANDROID_LOG_FATAL};
244static_assert(arraysize(kLogSeverityToAndroidLogPriority) == FATAL + 1,
245              "Mismatch in size of kLogSeverityToAndroidLogPriority and values "
246              "in LogSeverity");
247#endif
248
249void LogMessage::LogLine(const char* file, unsigned int line,
250                         LogSeverity log_severity, const char* message) {
251#ifdef __ANDROID__
252  const char* tag = ProgramInvocationShortName();
253  int priority = kLogSeverityToAndroidLogPriority[log_severity];
254  if (priority == ANDROID_LOG_FATAL) {
255    LOG_PRI(priority, tag, "%s:%u] %s", file, line, message);
256  } else {
257    LOG_PRI(priority, tag, "%s", message);
258  }
259#else
260  static const char* log_characters = "VDIWEF";
261  CHECK_EQ(strlen(log_characters), FATAL + 1U);
262  char severity = log_characters[log_severity];
263  fprintf(stderr, "%s %c %5d %5d %s:%u] %s\n", ProgramInvocationShortName(),
264          severity, getpid(), GetTid(), file, line, message);
265#endif
266}
267
268void LogMessage::LogLineLowStack(const char* file, unsigned int line,
269                                 LogSeverity log_severity, const char* message) {
270#ifdef __ANDROID__
271  // Use android_writeLog() to avoid stack-based buffers used by
272  // android_printLog().
273  const char* tag = ProgramInvocationShortName();
274  int priority = kLogSeverityToAndroidLogPriority[log_severity];
275  char* buf = nullptr;
276  size_t buf_size = 0u;
277  if (priority == ANDROID_LOG_FATAL) {
278    // Allocate buffer for snprintf(buf, buf_size, "%s:%u] %s", file, line,
279    // message) below.  If allocation fails, fall back to printing only the
280    // message.
281    buf_size = strlen(file) + 1 /* ':' */ +
282               std::numeric_limits<typeof(line)>::max_digits10 + 2 /* "] " */ +
283               strlen(message) + 1 /* terminating 0 */;
284    buf = reinterpret_cast<char*>(malloc(buf_size));
285  }
286  if (buf != nullptr) {
287    snprintf(buf, buf_size, "%s:%u] %s", file, line, message);
288    android_writeLog(priority, tag, buf);
289    free(buf);
290  } else {
291    android_writeLog(priority, tag, message);
292  }
293#else
294  static const char* log_characters = "VDIWEF";
295  CHECK_EQ(strlen(log_characters), FATAL + 1U);
296
297  const char* program_name = ProgramInvocationShortName();
298  write(STDERR_FILENO, program_name, strlen(program_name));
299  write(STDERR_FILENO, " ", 1);
300  write(STDERR_FILENO, &log_characters[log_severity], 1);
301  write(STDERR_FILENO, " ", 1);
302  // TODO: pid and tid.
303  write(STDERR_FILENO, file, strlen(file));
304  // TODO: line.
305  UNUSED(line);
306  write(STDERR_FILENO, "] ", 2);
307  write(STDERR_FILENO, message, strlen(message));
308  write(STDERR_FILENO, "\n", 1);
309#endif
310}
311
312ScopedLogSeverity::ScopedLogSeverity(LogSeverity level) {
313  old_ = gMinimumLogSeverity;
314  gMinimumLogSeverity = level;
315}
316
317ScopedLogSeverity::~ScopedLogSeverity() {
318  gMinimumLogSeverity = old_;
319}
320
321}  // namespace base
322}  // namespace android
323