logging.cpp revision 58310b49fc8a7a713b922319a849a419858db79e 
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;
112  Split(tags, ' ', &specs);
113  for (size_t i = 0; i < specs.size(); ++i) {
114    // "tag-pattern:[vdiwefs]"
115    std::string spec(specs[i]);
116    if (spec.size() == 3 && StartsWith(spec, "*:")) {
117      switch (spec[2]) {
118        case 'v':
119          gMinimumLogSeverity = VERBOSE;
120          continue;
121        case 'd':
122          gMinimumLogSeverity = DEBUG;
123          continue;
124        case 'i':
125          gMinimumLogSeverity = INFO;
126          continue;
127        case 'w':
128          gMinimumLogSeverity = WARNING;
129          continue;
130        case 'e':
131          gMinimumLogSeverity = ERROR;
132          continue;
133        case 'f':
134          gMinimumLogSeverity = FATAL;
135          continue;
136        // liblog will even suppress FATAL if you say 's' for silent, but that's
137        // crazy!
138        case 's':
139          gMinimumLogSeverity = FATAL;
140          continue;
141      }
142    }
143    LOG(FATAL) << "unsupported '" << spec << "' in ANDROID_LOG_TAGS (" << tags
144               << ")";
145  }
146}
147
148// This indirection greatly reduces the stack impact of having lots of
149// checks/logging in a function.
150class LogMessageData {
151 public:
152  LogMessageData(const char* file, unsigned int line, LogSeverity severity,
153                 int error)
154      : file_(file), line_number_(line), severity_(severity), error_(error) {
155    const char* last_slash = strrchr(file, '/');
156    file = (last_slash == nullptr) ? file : last_slash + 1;
157  }
158
159  const char* GetFile() const {
160    return file_;
161  }
162
163  unsigned int GetLineNumber() const {
164    return line_number_;
165  }
166
167  LogSeverity GetSeverity() const {
168    return severity_;
169  }
170
171  int GetError() const {
172    return error_;
173  }
174
175  std::ostream& GetBuffer() {
176    return buffer_;
177  }
178
179  std::string ToString() const {
180    return buffer_.str();
181  }
182
183 private:
184  std::ostringstream buffer_;
185  const char* const file_;
186  const unsigned int line_number_;
187  const LogSeverity severity_;
188  const int error_;
189
190  DISALLOW_COPY_AND_ASSIGN(LogMessageData);
191};
192
193LogMessage::LogMessage(const char* file, unsigned int line,
194                       LogSeverity severity, int error)
195    : data_(new LogMessageData(file, line, severity, error)) {
196}
197
198LogMessage::~LogMessage() {
199  if (data_->GetSeverity() < gMinimumLogSeverity) {
200    return;  // No need to format something we're not going to output.
201  }
202
203  // Finish constructing the message.
204  if (data_->GetError() != -1) {
205    data_->GetBuffer() << ": " << strerror(data_->GetError());
206  }
207  std::string msg(data_->ToString());
208
209  // Do the actual logging with the lock held.
210  {
211    std::lock_guard<std::mutex> lock(logging_lock);
212    if (msg.find('\n') == std::string::npos) {
213      LogLine(data_->GetFile(), data_->GetLineNumber(), data_->GetSeverity(),
214              msg.c_str());
215    } else {
216      msg += '\n';
217      size_t i = 0;
218      while (i < msg.size()) {
219        size_t nl = msg.find('\n', i);
220        msg[nl] = '\0';
221        LogLine(data_->GetFile(), data_->GetLineNumber(), data_->GetSeverity(),
222                &msg[i]);
223        i = nl + 1;
224      }
225    }
226  }
227
228  // Abort if necessary.
229  if (data_->GetSeverity() == FATAL) {
230#ifdef __ANDROID__
231    android_set_abort_message(msg.c_str());
232#endif
233    abort();
234  }
235}
236
237std::ostream& LogMessage::stream() {
238  return data_->GetBuffer();
239}
240
241#ifdef __ANDROID__
242static const android_LogPriority kLogSeverityToAndroidLogPriority[] = {
243    ANDROID_LOG_VERBOSE, ANDROID_LOG_DEBUG, ANDROID_LOG_INFO,
244    ANDROID_LOG_WARN,    ANDROID_LOG_ERROR, ANDROID_LOG_FATAL};
245static_assert(arraysize(kLogSeverityToAndroidLogPriority) == FATAL + 1,
246              "Mismatch in size of kLogSeverityToAndroidLogPriority and values "
247              "in LogSeverity");
248#endif
249
250void LogMessage::LogLine(const char* file, unsigned int line,
251                         LogSeverity log_severity, const char* message) {
252#ifdef __ANDROID__
253  const char* tag = ProgramInvocationShortName();
254  int priority = kLogSeverityToAndroidLogPriority[log_severity];
255  if (priority == ANDROID_LOG_FATAL) {
256    LOG_PRI(priority, tag, "%s:%u] %s", file, line, message);
257  } else {
258    LOG_PRI(priority, tag, "%s", message);
259  }
260#else
261  static const char* log_characters = "VDIWEF";
262  CHECK_EQ(strlen(log_characters), FATAL + 1U);
263  char severity = log_characters[log_severity];
264  fprintf(stderr, "%s %c %5d %5d %s:%u] %s\n", ProgramInvocationShortName(),
265          severity, getpid(), GetTid(), file, line, message);
266#endif
267}
268
269void LogMessage::LogLineLowStack(const char* file, unsigned int line,
270                                 LogSeverity log_severity, const char* message) {
271#ifdef __ANDROID__
272  // Use android_writeLog() to avoid stack-based buffers used by
273  // android_printLog().
274  const char* tag = ProgramInvocationShortName();
275  int priority = kLogSeverityToAndroidLogPriority[log_severity];
276  char* buf = nullptr;
277  size_t buf_size = 0u;
278  if (priority == ANDROID_LOG_FATAL) {
279    // Allocate buffer for snprintf(buf, buf_size, "%s:%u] %s", file, line,
280    // message) below.  If allocation fails, fall back to printing only the
281    // message.
282    buf_size = strlen(file) + 1 /* ':' */ +
283               std::numeric_limits<typeof(line)>::max_digits10 + 2 /* "] " */ +
284               strlen(message) + 1 /* terminating 0 */;
285    buf = reinterpret_cast<char*>(malloc(buf_size));
286  }
287  if (buf != nullptr) {
288    snprintf(buf, buf_size, "%s:%u] %s", file, line, message);
289    android_writeLog(priority, tag, buf);
290    free(buf);
291  } else {
292    android_writeLog(priority, tag, message);
293  }
294#else
295  static const char* log_characters = "VDIWEF";
296  CHECK_EQ(strlen(log_characters), FATAL + 1U);
297
298  const char* program_name = ProgramInvocationShortName();
299  write(STDERR_FILENO, program_name, strlen(program_name));
300  write(STDERR_FILENO, " ", 1);
301  write(STDERR_FILENO, &log_characters[log_severity], 1);
302  write(STDERR_FILENO, " ", 1);
303  // TODO: pid and tid.
304  write(STDERR_FILENO, file, strlen(file));
305  // TODO: line.
306  UNUSED(line);
307  write(STDERR_FILENO, "] ", 2);
308  write(STDERR_FILENO, message, strlen(message));
309  write(STDERR_FILENO, "\n", 1);
310#endif
311}
312
313ScopedLogSeverity::ScopedLogSeverity(LogSeverity level) {
314  old_ = gMinimumLogSeverity;
315  gMinimumLogSeverity = level;
316}
317
318ScopedLogSeverity::~ScopedLogSeverity() {
319  gMinimumLogSeverity = old_;
320}
321
322}  // namespace base
323}  // namespace android
324