Merge "Add google3 style logging to libbase."

1 files changed, 323 insertions, 0 deletions

diff --git a/base/logging.cpp b/base/logging.cpp
new file mode 100644
index 0000000..3d6c0c2
--- /dev/null
+++ b/base/logging.cpp
@@ -0,0 +1,323 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "base/logging.h"
+
+#include <iostream>
+#include <limits>
+#include <sstream>
+#include <string>
+#include <vector>
+
+#include "base/strings.h"
+
+// Headers for LogMessage::LogLine.
+#ifdef __ANDROID__
+#include <android/set_abort_message.h>
+#include "cutils/log.h"
+#else
+#include <sys/types.h>
+#include <unistd.h>
+#endif
+
+// For GetTid.
+#if defined(__APPLE__)
+#include "AvailabilityMacros.h"  // For MAC_OS_X_VERSION_MAX_ALLOWED
+#include <sys/syscall.h>
+#include <sys/time.h>
+#elif !defined(__BIONIC__)
+#include <syscall.h>
+#endif
+
+namespace android {
+namespace base {
+
+static std::mutex logging_lock;
+
+static LogSeverity gMinimumLogSeverity = INFO;
+static std::unique_ptr<std::string> gCmdLine;
+static std::unique_ptr<std::string> gProgramInvocationName;
+static std::unique_ptr<std::string> gProgramInvocationShortName;
+
+#ifndef __ANDROID__
+static pid_t GetTid() {
+#if defined(__APPLE__)
+  uint64_t owner;
+  // Requires Mac OS 10.6
+  CHECK_PTHREAD_CALL(pthread_threadid_np, (NULL, &owner), __FUNCTION__);
+  return owner;
+#else
+  return syscall(__NR_gettid);
+#endif
+}
+#endif  // __ANDROID__
+
+const char* GetCmdLine() {
+  return (gCmdLine.get() != nullptr) ? gCmdLine->c_str() : nullptr;
+}
+
+const char* ProgramInvocationName() {
+  return (gProgramInvocationName.get() != nullptr)
+             ? gProgramInvocationName->c_str()
+             : "unknown";
+}
+
+const char* ProgramInvocationShortName() {
+  return (gProgramInvocationShortName.get() != nullptr)
+             ? gProgramInvocationShortName->c_str()
+             : "unknown";
+}
+
+void InitLogging(char* argv[]) {
+  if (gCmdLine.get() != nullptr) {
+    return;
+  }
+
+  // Stash the command line for later use. We can use /proc/self/cmdline on
+  // Linux to recover this, but we don't have that luxury on the Mac, and there
+  // are a couple of argv[0] variants that are commonly used.
+  if (argv != nullptr) {
+    gCmdLine.reset(new std::string(argv[0]));
+    for (size_t i = 1; argv[i] != nullptr; ++i) {
+      gCmdLine->append(" ");
+      gCmdLine->append(argv[i]);
+    }
+    gProgramInvocationName.reset(new std::string(argv[0]));
+    const char* last_slash = strrchr(argv[0], '/');
+    gProgramInvocationShortName.reset(
+        new std::string((last_slash != nullptr) ? last_slash + 1 : argv[0]));
+  } else {
+    // TODO: fall back to /proc/self/cmdline when argv is NULL on Linux.
+    gCmdLine.reset(new std::string("<unset>"));
+  }
+  const char* tags = getenv("ANDROID_LOG_TAGS");
+  if (tags == nullptr) {
+    return;
+  }
+
+  std::vector<std::string> specs;
+  Split(tags, ' ', &specs);
+  for (size_t i = 0; i < specs.size(); ++i) {
+    // "tag-pattern:[vdiwefs]"
+    std::string spec(specs[i]);
+    if (spec.size() == 3 && StartsWith(spec, "*:")) {
+      switch (spec[2]) {
+        case 'v':
+          gMinimumLogSeverity = VERBOSE;
+          continue;
+        case 'd':
+          gMinimumLogSeverity = DEBUG;
+          continue;
+        case 'i':
+          gMinimumLogSeverity = INFO;
+          continue;
+        case 'w':
+          gMinimumLogSeverity = WARNING;
+          continue;
+        case 'e':
+          gMinimumLogSeverity = ERROR;
+          continue;
+        case 'f':
+          gMinimumLogSeverity = FATAL;
+          continue;
+        // liblog will even suppress FATAL if you say 's' for silent, but that's
+        // crazy!
+        case 's':
+          gMinimumLogSeverity = FATAL;
+          continue;
+      }
+    }
+    LOG(FATAL) << "unsupported '" << spec << "' in ANDROID_LOG_TAGS (" << tags
+               << ")";
+  }
+}
+
+// This indirection greatly reduces the stack impact of having lots of
+// checks/logging in a function.
+class LogMessageData {
+ public:
+  LogMessageData(const char* file, unsigned int line, LogSeverity severity,
+                 int error)
+      : file_(file), line_number_(line), severity_(severity), error_(error) {
+    const char* last_slash = strrchr(file, '/');
+    file = (last_slash == nullptr) ? file : last_slash + 1;
+  }
+
+  const char* GetFile() const {
+    return file_;
+  }
+
+  unsigned int GetLineNumber() const {
+    return line_number_;
+  }
+
+  LogSeverity GetSeverity() const {
+    return severity_;
+  }
+
+  int GetError() const {
+    return error_;
+  }
+
+  std::ostream& GetBuffer() {
+    return buffer_;
+  }
+
+  std::string ToString() const {
+    return buffer_.str();
+  }
+
+ private:
+  std::ostringstream buffer_;
+  const char* const file_;
+  const unsigned int line_number_;
+  const LogSeverity severity_;
+  const int error_;
+
+  DISALLOW_COPY_AND_ASSIGN(LogMessageData);
+};
+
+LogMessage::LogMessage(const char* file, unsigned int line,
+                       LogSeverity severity, int error)
+    : data_(new LogMessageData(file, line, severity, error)) {
+}
+
+LogMessage::~LogMessage() {
+  if (data_->GetSeverity() < gMinimumLogSeverity) {
+    return;  // No need to format something we're not going to output.
+  }
+
+  // Finish constructing the message.
+  if (data_->GetError() != -1) {
+    data_->GetBuffer() << ": " << strerror(data_->GetError());
+  }
+  std::string msg(data_->ToString());
+
+  // Do the actual logging with the lock held.
+  {
+    std::lock_guard<std::mutex> lock(logging_lock);
+    if (msg.find('\n') == std::string::npos) {
+      LogLine(data_->GetFile(), data_->GetLineNumber(), data_->GetSeverity(),
+              msg.c_str());
+    } else {
+      msg += '\n';
+      size_t i = 0;
+      while (i < msg.size()) {
+        size_t nl = msg.find('\n', i);
+        msg[nl] = '\0';
+        LogLine(data_->GetFile(), data_->GetLineNumber(), data_->GetSeverity(),
+                &msg[i]);
+        i = nl + 1;
+      }
+    }
+  }
+
+  // Abort if necessary.
+  if (data_->GetSeverity() == FATAL) {
+#ifdef __ANDROID__
+    android_set_abort_message(msg.c_str());
+#endif
+    abort();
+  }
+}
+
+std::ostream& LogMessage::stream() {
+  return data_->GetBuffer();
+}
+
+#ifdef __ANDROID__
+static const android_LogPriority kLogSeverityToAndroidLogPriority[] = {
+    ANDROID_LOG_VERBOSE, ANDROID_LOG_DEBUG, ANDROID_LOG_INFO,
+    ANDROID_LOG_WARN,    ANDROID_LOG_ERROR, ANDROID_LOG_FATAL};
+static_assert(arraysize(kLogSeverityToAndroidLogPriority) == FATAL + 1,
+              "Mismatch in size of kLogSeverityToAndroidLogPriority and values "
+              "in LogSeverity");
+#endif
+
+void LogMessage::LogLine(const char* file, unsigned int line,
+                         LogSeverity log_severity, const char* message) {
+#ifdef __ANDROID__
+  const char* tag = ProgramInvocationShortName();
+  int priority = kLogSeverityToAndroidLogPriority[log_severity];
+  if (priority == ANDROID_LOG_FATAL) {
+    LOG_PRI(priority, tag, "%s:%u] %s", file, line, message);
+  } else {
+    LOG_PRI(priority, tag, "%s", message);
+  }
+#else
+  static const char* log_characters = "VDIWEF";
+  CHECK_EQ(strlen(log_characters), FATAL + 1U);
+  char severity = log_characters[log_severity];
+  fprintf(stderr, "%s %c %5d %5d %s:%u] %s\n", ProgramInvocationShortName(),
+          severity, getpid(), GetTid(), file, line, message);
+#endif
+}
+
+void LogMessage::LogLineLowStack(const char* file, unsigned int line,
+                                 LogSeverity log_severity, const char* message) {
+#ifdef __ANDROID__
+  // Use android_writeLog() to avoid stack-based buffers used by
+  // android_printLog().
+  const char* tag = ProgramInvocationShortName();
+  int priority = kLogSeverityToAndroidLogPriority[log_severity];
+  char* buf = nullptr;
+  size_t buf_size = 0u;
+  if (priority == ANDROID_LOG_FATAL) {
+    // Allocate buffer for snprintf(buf, buf_size, "%s:%u] %s", file, line,
+    // message) below.  If allocation fails, fall back to printing only the
+    // message.
+    buf_size = strlen(file) + 1 /* ':' */ +
+               std::numeric_limits<typeof(line)>::max_digits10 + 2 /* "] " */ +
+               strlen(message) + 1 /* terminating 0 */;
+    buf = reinterpret_cast<char*>(malloc(buf_size));
+  }
+  if (buf != nullptr) {
+    snprintf(buf, buf_size, "%s:%u] %s", file, line, message);
+    android_writeLog(priority, tag, buf);
+    free(buf);
+  } else {
+    android_writeLog(priority, tag, message);
+  }
+#else
+  static const char* log_characters = "VDIWEF";
+  CHECK_EQ(strlen(log_characters), FATAL + 1U);
+
+  const char* program_name = ProgramInvocationShortName();
+  write(STDERR_FILENO, program_name, strlen(program_name));
+  write(STDERR_FILENO, " ", 1);
+  write(STDERR_FILENO, &log_characters[log_severity], 1);
+  write(STDERR_FILENO, " ", 1);
+  // TODO: pid and tid.
+  write(STDERR_FILENO, file, strlen(file));
+  // TODO: line.
+  UNUSED(line);
+  write(STDERR_FILENO, "] ", 2);
+  write(STDERR_FILENO, message, strlen(message));
+  write(STDERR_FILENO, "\n", 1);
+#endif
+}
+
+ScopedLogSeverity::ScopedLogSeverity(LogSeverity level) {
+  old_ = gMinimumLogSeverity;
+  gMinimumLogSeverity = level;
+}
+
+ScopedLogSeverity::~ScopedLogSeverity() {
+  gMinimumLogSeverity = old_;
+}
+
+}  // namespace base
+}  // namespace android