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 <mutex>
31 #include <sstream>
32 #include <string>
33 #include <utility>
34 #include <vector>
35 
36 #include "base/strings.h"
37 #include "cutils/threads.h"
38 
39 // Headers for LogMessage::LogLine.
40 #ifdef __ANDROID__
41 #include <android/set_abort_message.h>
42 #include "cutils/log.h"
43 #else
44 #include <sys/types.h>
45 #include <unistd.h>
46 #endif
47 
48 namespace android {
49 namespace base {
50 
51 static std::mutex logging_lock;
52 
53 #ifdef __ANDROID__
54 static LogFunction gLogger = LogdLogger();
55 #else
56 static LogFunction gLogger = StderrLogger;
57 #endif
58 
59 static bool gInitialized = false;
60 static LogSeverity gMinimumLogSeverity = INFO;
61 static std::unique_ptr<std::string> gProgramInvocationName;
62 
63 #if defined(__GLIBC__)
getprogname()64 static const char* getprogname() {
65   return program_invocation_short_name;
66 }
67 #endif
68 
ProgramInvocationName()69 static const char* ProgramInvocationName() {
70   if (gProgramInvocationName == nullptr) {
71     gProgramInvocationName.reset(new std::string(getprogname()));
72   }
73 
74   return gProgramInvocationName->c_str();
75 }
76 
StderrLogger(LogId,LogSeverity severity,const char *,const char * file,unsigned int line,const char * message)77 void StderrLogger(LogId, LogSeverity severity, const char*, const char* file,
78                   unsigned int line, const char* message) {
79   static const char* log_characters = "VDIWEF";
80   CHECK_EQ(strlen(log_characters), FATAL + 1U);
81   char severity_char = log_characters[severity];
82   fprintf(stderr, "%s %c %5d %5d %s:%u] %s\n", ProgramInvocationName(),
83           severity_char, getpid(), gettid(), file, line, message);
84 }
85 
86 
87 #ifdef __ANDROID__
LogdLogger(LogId default_log_id)88 LogdLogger::LogdLogger(LogId default_log_id) : default_log_id_(default_log_id) {
89 }
90 
91 static const android_LogPriority kLogSeverityToAndroidLogPriority[] = {
92     ANDROID_LOG_VERBOSE, ANDROID_LOG_DEBUG, ANDROID_LOG_INFO,
93     ANDROID_LOG_WARN,    ANDROID_LOG_ERROR, ANDROID_LOG_FATAL,
94 };
95 static_assert(arraysize(kLogSeverityToAndroidLogPriority) == FATAL + 1,
96               "Mismatch in size of kLogSeverityToAndroidLogPriority and values "
97               "in LogSeverity");
98 
99 static const log_id kLogIdToAndroidLogId[] = {
100     LOG_ID_MAX, LOG_ID_MAIN, LOG_ID_SYSTEM,
101 };
102 static_assert(arraysize(kLogIdToAndroidLogId) == SYSTEM + 1,
103               "Mismatch in size of kLogIdToAndroidLogId and values in LogId");
104 
operator ()(LogId id,LogSeverity severity,const char * tag,const char * file,unsigned int line,const char * message)105 void LogdLogger::operator()(LogId id, LogSeverity severity, const char* tag,
106                             const char* file, unsigned int line,
107                             const char* message) {
108   int priority = kLogSeverityToAndroidLogPriority[severity];
109   if (id == DEFAULT) {
110     id = default_log_id_;
111   }
112 
113   log_id lg_id = kLogIdToAndroidLogId[id];
114 
115   if (priority == ANDROID_LOG_FATAL) {
116     __android_log_buf_print(lg_id, priority, tag, "%s:%u] %s", file, line,
117                             message);
118   } else {
119     __android_log_buf_print(lg_id, priority, tag, "%s", message);
120   }
121 }
122 #endif
123 
InitLogging(char * argv[],LogFunction && logger)124 void InitLogging(char* argv[], LogFunction&& logger) {
125   SetLogger(std::forward<LogFunction>(logger));
126   InitLogging(argv);
127 }
128 
InitLogging(char * argv[])129 void InitLogging(char* argv[]) {
130   if (gInitialized) {
131     return;
132   }
133 
134   gInitialized = true;
135 
136   // Stash the command line for later use. We can use /proc/self/cmdline on
137   // Linux to recover this, but we don't have that luxury on the Mac, and there
138   // are a couple of argv[0] variants that are commonly used.
139   if (argv != nullptr) {
140     gProgramInvocationName.reset(new std::string(basename(argv[0])));
141   }
142 
143   const char* tags = getenv("ANDROID_LOG_TAGS");
144   if (tags == nullptr) {
145     return;
146   }
147 
148   std::vector<std::string> specs = Split(tags, " ");
149   for (size_t i = 0; i < specs.size(); ++i) {
150     // "tag-pattern:[vdiwefs]"
151     std::string spec(specs[i]);
152     if (spec.size() == 3 && StartsWith(spec, "*:")) {
153       switch (spec[2]) {
154         case 'v':
155           gMinimumLogSeverity = VERBOSE;
156           continue;
157         case 'd':
158           gMinimumLogSeverity = DEBUG;
159           continue;
160         case 'i':
161           gMinimumLogSeverity = INFO;
162           continue;
163         case 'w':
164           gMinimumLogSeverity = WARNING;
165           continue;
166         case 'e':
167           gMinimumLogSeverity = ERROR;
168           continue;
169         case 'f':
170           gMinimumLogSeverity = FATAL;
171           continue;
172         // liblog will even suppress FATAL if you say 's' for silent, but that's
173         // crazy!
174         case 's':
175           gMinimumLogSeverity = FATAL;
176           continue;
177       }
178     }
179     LOG(FATAL) << "unsupported '" << spec << "' in ANDROID_LOG_TAGS (" << tags
180                << ")";
181   }
182 }
183 
SetLogger(LogFunction && logger)184 void SetLogger(LogFunction&& logger) {
185   std::lock_guard<std::mutex> lock(logging_lock);
186   gLogger = std::move(logger);
187 }
188 
189 // This indirection greatly reduces the stack impact of having lots of
190 // checks/logging in a function.
191 class LogMessageData {
192  public:
LogMessageData(const char * file,unsigned int line,LogId id,LogSeverity severity,int error)193   LogMessageData(const char* file, unsigned int line, LogId id,
194                  LogSeverity severity, int error)
195       : file_(file),
196         line_number_(line),
197         id_(id),
198         severity_(severity),
199         error_(error) {
200     const char* last_slash = strrchr(file, '/');
201     file = (last_slash == nullptr) ? file : last_slash + 1;
202   }
203 
GetFile() const204   const char* GetFile() const {
205     return file_;
206   }
207 
GetLineNumber() const208   unsigned int GetLineNumber() const {
209     return line_number_;
210   }
211 
GetSeverity() const212   LogSeverity GetSeverity() const {
213     return severity_;
214   }
215 
GetId() const216   LogId GetId() const {
217     return id_;
218   }
219 
GetError() const220   int GetError() const {
221     return error_;
222   }
223 
GetBuffer()224   std::ostream& GetBuffer() {
225     return buffer_;
226   }
227 
ToString() const228   std::string ToString() const {
229     return buffer_.str();
230   }
231 
232  private:
233   std::ostringstream buffer_;
234   const char* const file_;
235   const unsigned int line_number_;
236   const LogId id_;
237   const LogSeverity severity_;
238   const int error_;
239 
240   DISALLOW_COPY_AND_ASSIGN(LogMessageData);
241 };
242 
LogMessage(const char * file,unsigned int line,LogId id,LogSeverity severity,int error)243 LogMessage::LogMessage(const char* file, unsigned int line, LogId id,
244                        LogSeverity severity, int error)
245     : data_(new LogMessageData(file, line, id, severity, error)) {
246 }
247 
~LogMessage()248 LogMessage::~LogMessage() {
249   if (data_->GetSeverity() < gMinimumLogSeverity) {
250     return;  // No need to format something we're not going to output.
251   }
252 
253   // Finish constructing the message.
254   if (data_->GetError() != -1) {
255     data_->GetBuffer() << ": " << strerror(data_->GetError());
256   }
257   std::string msg(data_->ToString());
258 
259   if (msg.find('\n') == std::string::npos) {
260     LogLine(data_->GetFile(), data_->GetLineNumber(), data_->GetId(),
261             data_->GetSeverity(), msg.c_str());
262   } else {
263     msg += '\n';
264     size_t i = 0;
265     while (i < msg.size()) {
266       size_t nl = msg.find('\n', i);
267       msg[nl] = '\0';
268       LogLine(data_->GetFile(), data_->GetLineNumber(), data_->GetId(),
269               data_->GetSeverity(), &msg[i]);
270       i = nl + 1;
271     }
272   }
273 
274   // Abort if necessary.
275   if (data_->GetSeverity() == FATAL) {
276 #ifdef __ANDROID__
277     android_set_abort_message(msg.c_str());
278 #endif
279     abort();
280   }
281 }
282 
stream()283 std::ostream& LogMessage::stream() {
284   return data_->GetBuffer();
285 }
286 
LogLine(const char * file,unsigned int line,LogId id,LogSeverity severity,const char * message)287 void LogMessage::LogLine(const char* file, unsigned int line, LogId id,
288                          LogSeverity severity, const char* message) {
289   const char* tag = ProgramInvocationName();
290   std::lock_guard<std::mutex> lock(logging_lock);
291   gLogger(id, severity, tag, file, line, message);
292 }
293 
ScopedLogSeverity(LogSeverity level)294 ScopedLogSeverity::ScopedLogSeverity(LogSeverity level) {
295   old_ = gMinimumLogSeverity;
296   gMinimumLogSeverity = level;
297 }
298 
~ScopedLogSeverity()299 ScopedLogSeverity::~ScopedLogSeverity() {
300   gMinimumLogSeverity = old_;
301 }
302 
303 }  // namespace base
304 }  // namespace android
305