diff --git a/base/include/android-base/logging.h b/base/include/android-base/logging.h
index f93c696..afff2c9 100644
--- a/base/include/android-base/logging.h
+++ b/base/include/android-base/logging.h
@@ -42,6 +42,10 @@
 // By default, output goes to logcat on Android and stderr on the host.
 // A process can use `SetLogger` to decide where all logging goes.
 // Implementations are provided for logcat, stderr, and dmesg.
+//
+// By default, the process' name is used as the log tag.
+// Code can choose a specific log tag by defining LOG_TAG
+// before including this header.
 
 // This header also provides assertions:
 //
@@ -63,6 +67,16 @@
 
 #include "android-base/macros.h"
 
+// Note: DO NOT USE DIRECTLY. Use LOG_TAG instead.
+#ifdef _LOG_TAG_INTERNAL
+#error "_LOG_TAG_INTERNAL must not be defined"
+#endif
+#ifdef LOG_TAG
+#define _LOG_TAG_INTERNAL LOG_TAG
+#else
+#define _LOG_TAG_INTERNAL nullptr
+#endif
+
 namespace android {
 namespace base {
 
@@ -201,10 +215,10 @@
 
 // Get an ostream that can be used for logging at the given severity and to the
 // given destination. The same notes as for LOG_STREAM apply.
-#define LOG_STREAM_TO(dest, severity)                                   \
-  ::android::base::LogMessage(__FILE__, __LINE__,                       \
-                              ::android::base::dest,                    \
-                              SEVERITY_LAMBDA(severity), -1).stream()
+#define LOG_STREAM_TO(dest, severity)                                           \
+  ::android::base::LogMessage(__FILE__, __LINE__, ::android::base::dest,        \
+                              SEVERITY_LAMBDA(severity), _LOG_TAG_INTERNAL, -1) \
+      .stream()
 
 // Logs a message to logcat on Android otherwise to stderr. If the severity is
 // FATAL it also causes an abort. For example:
@@ -231,10 +245,10 @@
 #define PLOG(severity) PLOG_TO(DEFAULT, severity)
 
 // Behaves like PLOG, but logs to the specified log ID.
-#define PLOG_TO(dest, severity)                                              \
-  LOGGING_PREAMBLE(severity) &&                                              \
-      ::android::base::LogMessage(__FILE__, __LINE__, ::android::base::dest, \
-                                  SEVERITY_LAMBDA(severity), errno)          \
+#define PLOG_TO(dest, severity)                                                        \
+  LOGGING_PREAMBLE(severity) &&                                                        \
+      ::android::base::LogMessage(__FILE__, __LINE__, ::android::base::dest,           \
+                                  SEVERITY_LAMBDA(severity), _LOG_TAG_INTERNAL, errno) \
           .stream()
 
 // Marker that code is yet to be implemented.
@@ -247,23 +261,26 @@
 //
 //     CHECK(false == true) results in a log message of
 //       "Check failed: false == true".
-#define CHECK(x)                                                                \
-  LIKELY((x)) || ABORT_AFTER_LOG_FATAL_EXPR(false) ||                           \
-      ::android::base::LogMessage(                                              \
-          __FILE__, __LINE__, ::android::base::DEFAULT, ::android::base::FATAL, \
-          -1).stream()                                                          \
+#define CHECK(x)                                                                 \
+  LIKELY((x)) || ABORT_AFTER_LOG_FATAL_EXPR(false) ||                            \
+      ::android::base::LogMessage(__FILE__, __LINE__, ::android::base::DEFAULT,  \
+                                  ::android::base::FATAL, _LOG_TAG_INTERNAL, -1) \
+              .stream()                                                          \
           << "Check failed: " #x << " "
 
+// clang-format off
 // Helper for CHECK_xx(x,y) macros.
-#define CHECK_OP(LHS, RHS, OP)                                              \
-  for (auto _values = ::android::base::MakeEagerEvaluator(LHS, RHS);        \
-       UNLIKELY(!(_values.lhs OP _values.rhs));                             \
-       /* empty */)                                                         \
-  ABORT_AFTER_LOG_FATAL                                                     \
-  ::android::base::LogMessage(__FILE__, __LINE__, ::android::base::DEFAULT, \
-                              ::android::base::FATAL, -1).stream()          \
-      << "Check failed: " << #LHS << " " << #OP << " " << #RHS              \
-      << " (" #LHS "=" << _values.lhs << ", " #RHS "=" << _values.rhs << ") "
+#define CHECK_OP(LHS, RHS, OP)                                                                 \
+  for (auto _values = ::android::base::MakeEagerEvaluator(LHS, RHS);                           \
+       UNLIKELY(!(_values.lhs OP _values.rhs));                                                \
+       /* empty */)                                                                            \
+  ABORT_AFTER_LOG_FATAL                                                                        \
+  ::android::base::LogMessage(__FILE__, __LINE__, ::android::base::DEFAULT,                    \
+                              ::android::base::FATAL, _LOG_TAG_INTERNAL, -1)                   \
+          .stream()                                                                            \
+      << "Check failed: " << #LHS << " " << #OP << " " << #RHS << " (" #LHS "=" << _values.lhs \
+      << ", " #RHS "=" << _values.rhs << ") "
+// clang-format on
 
 // Check whether a condition holds between x and y, LOG(FATAL) if not. The value
 // of the expressions x and y is evaluated once. Extra logging can be appended
@@ -278,14 +295,17 @@
 #define CHECK_GE(x, y) CHECK_OP(x, y, >= )
 #define CHECK_GT(x, y) CHECK_OP(x, y, > )
 
+// clang-format off
 // Helper for CHECK_STRxx(s1,s2) macros.
 #define CHECK_STROP(s1, s2, sense)                                             \
   while (UNLIKELY((strcmp(s1, s2) == 0) != (sense)))                           \
     ABORT_AFTER_LOG_FATAL                                                      \
     ::android::base::LogMessage(__FILE__, __LINE__, ::android::base::DEFAULT,  \
-                                ::android::base::FATAL, -1).stream()           \
+                                ::android::base::FATAL, _LOG_TAG_INTERNAL, -1) \
+        .stream()                                                              \
         << "Check failed: " << "\"" << (s1) << "\""                            \
         << ((sense) ? " == " : " != ") << "\"" << (s2) << "\""
+// clang-format on
 
 // Check for string (const char*) equality between s1 and s2, LOG(FATAL) if not.
 #define CHECK_STREQ(s1, s2) CHECK_STROP(s1, s2, true)
@@ -400,8 +420,8 @@
 // of a CHECK. The destructor will abort if the severity is FATAL.
 class LogMessage {
  public:
-  LogMessage(const char* file, unsigned int line, LogId id,
-             LogSeverity severity, int error);
+  LogMessage(const char* file, unsigned int line, LogId id, LogSeverity severity, const char* tag,
+             int error);
 
   ~LogMessage();
 
@@ -410,12 +430,17 @@
   std::ostream& stream();
 
   // The routine that performs the actual logging.
-  static void LogLine(const char* file, unsigned int line, LogId id,
-                      LogSeverity severity, const char* msg);
+  static void LogLine(const char* file, unsigned int line, LogId id, LogSeverity severity,
+                      const char* tag, const char* msg);
 
  private:
   const std::unique_ptr<LogMessageData> data_;
 
+  // TODO(b/35361699): remove these symbols once all prebuilds stop using it.
+  LogMessage(const char* file, unsigned int line, LogId id, LogSeverity severity, int error);
+  static void LogLine(const char* file, unsigned int line, LogId id, LogSeverity severity,
+                      const char* msg);
+
   DISALLOW_COPY_AND_ASSIGN(LogMessage);
 };
 
diff --git a/base/logging.cpp b/base/logging.cpp
index 75078e5..0f2012a 100644
--- a/base/logging.cpp
+++ b/base/logging.cpp
@@ -187,8 +187,8 @@
 }
 #endif
 
-void StderrLogger(LogId, LogSeverity severity, const char*, const char* file,
-                  unsigned int line, const char* message) {
+void StderrLogger(LogId, LogSeverity severity, const char* tag, const char* file, unsigned int line,
+                  const char* message) {
   struct tm now;
   time_t t = time(nullptr);
 
@@ -205,8 +205,8 @@
   static_assert(arraysize(log_characters) - 1 == FATAL + 1,
                 "Mismatch in size of log_characters and values in LogSeverity");
   char severity_char = log_characters[severity];
-  fprintf(stderr, "%s %c %s %5d %5d %s:%u] %s\n", ProgramInvocationName().c_str(),
-          severity_char, timestamp, getpid(), GetThreadId(), file, line, message);
+  fprintf(stderr, "%s %c %s %5d %5d %s:%u] %s\n", tag ? tag : "nullptr", severity_char, timestamp,
+          getpid(), GetThreadId(), file, line, message);
 }
 
 void DefaultAborter(const char* abort_message) {
@@ -344,14 +344,14 @@
 // checks/logging in a function.
 class LogMessageData {
  public:
-  LogMessageData(const char* file, unsigned int line, LogId id,
-                 LogSeverity severity, int error)
+  LogMessageData(const char* file, unsigned int line, LogId id, LogSeverity severity,
+                 const char* tag, int error)
       : file_(GetFileBasename(file)),
         line_number_(line),
         id_(id),
         severity_(severity),
-        error_(error) {
-  }
+        tag_(tag),
+        error_(error) {}
 
   const char* GetFile() const {
     return file_;
@@ -365,6 +365,8 @@
     return severity_;
   }
 
+  const char* GetTag() const { return tag_; }
+
   LogId GetId() const {
     return id_;
   }
@@ -387,15 +389,19 @@
   const unsigned int line_number_;
   const LogId id_;
   const LogSeverity severity_;
+  const char* const tag_;
   const int error_;
 
   DISALLOW_COPY_AND_ASSIGN(LogMessageData);
 };
 
-LogMessage::LogMessage(const char* file, unsigned int line, LogId id,
-                       LogSeverity severity, int error)
-    : data_(new LogMessageData(file, line, id, severity, error)) {
-}
+LogMessage::LogMessage(const char* file, unsigned int line, LogId id, LogSeverity severity,
+                       const char* tag, int error)
+    : data_(new LogMessageData(file, line, id, severity, tag, error)) {}
+
+LogMessage::LogMessage(const char* file, unsigned int line, LogId id, LogSeverity severity,
+                       int error)
+    : LogMessage(file, line, id, severity, nullptr, error) {}
 
 LogMessage::~LogMessage() {
   // Check severity again. This is duplicate work wrt/ LOG macros, but not LOG_STREAM.
@@ -413,16 +419,16 @@
     // Do the actual logging with the lock held.
     std::lock_guard<std::mutex> lock(LoggingLock());
     if (msg.find('\n') == std::string::npos) {
-      LogLine(data_->GetFile(), data_->GetLineNumber(), data_->GetId(),
-              data_->GetSeverity(), msg.c_str());
+      LogLine(data_->GetFile(), data_->GetLineNumber(), data_->GetId(), data_->GetSeverity(),
+              data_->GetTag(), 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_->GetId(),
-                data_->GetSeverity(), &msg[i]);
+        LogLine(data_->GetFile(), data_->GetLineNumber(), data_->GetId(), data_->GetSeverity(),
+                data_->GetTag(), &msg[i]);
         // Undo the zero-termination so we can give the complete message to the aborter.
         msg[nl] = '\n';
         i = nl + 1;
@@ -440,12 +446,17 @@
   return data_->GetBuffer();
 }
 
-void LogMessage::LogLine(const char* file, unsigned int line, LogId id,
-                         LogSeverity severity, const char* message) {
-  const char* tag = ProgramInvocationName().c_str();
+void LogMessage::LogLine(const char* file, unsigned int line, LogId id, LogSeverity severity,
+                         const char* tag, const char* message) {
+  if (tag == nullptr) tag = ProgramInvocationName().c_str();
   Logger()(id, severity, tag, file, line, message);
 }
 
+void LogMessage::LogLine(const char* file, unsigned int line, LogId id, LogSeverity severity,
+                         const char* message) {
+  LogLine(file, line, id, severity, nullptr, message);
+}
+
 LogSeverity GetMinimumLogSeverity() {
     return gMinimumLogSeverity;
 }