common/logging: Create a new backed for android's logcat

src/android/app/src/main/jni/id_cache.cpp

@@ -102,7 +102,7 @@ jint JNI_OnLoad(JavaVM* vm, void* reserved) {
     Log::Filter log_filter;
     log_filter.ParseFilterString(Settings::values.log_filter);
     Log::SetGlobalFilter(log_filter);
-    Log::AddBackend(std::make_unique<Log::ColorConsoleBackend>());
+    Log::AddBackend(std::make_unique<Log::LogcatBackend>());
     FileUtil::CreateFullPath(FileUtil::GetUserPath(FileUtil::UserPath::LogDir));
     Log::AddBackend(std::make_unique<Log::FileBackend>(
         FileUtil::GetUserPath(FileUtil::UserPath::LogDir) + LOG_FILE));

src/common/logging/backend.cpp

@@ -140,6 +140,10 @@ void ColorConsoleBackend::Write(const Entry& entry) {
     PrintColoredMessage(entry);
 }
 
+void LogcatBackend::Write(const Entry& entry) {
+    PrintMessageToLogcat(entry);
+}
+
 // _SH_DENYWR allows read only access to the file for other programs.
 // It is #defined to 0 on other platforms
 FileBackend::FileBackend(const std::string& filename)

src/common/logging/backend.h

@@ -81,6 +81,21 @@ public:
     void Write(const Entry& entry) override;
 };
 
+/**
+ * Backend that writes to the Android logcat
+ */
+class LogcatBackend : public Backend {
+public:
+    static const char* Name() {
+        return "logcat";
+    }
+
+    const char* GetName() const override {
+        return Name();
+    }
+    void Write(const Entry& entry) override;
+};
+
 /**
  * Backend that writes to a file passed into the constructor
  */

src/common/logging/text_formatter.cpp

@@ -34,13 +34,7 @@ std::string FormatLogMessage(const Entry& entry) {
 
 void PrintMessage(const Entry& entry) {
     const auto str = FormatLogMessage(entry).append(1, '\n');
-#ifdef ANDROID
-    // Android's log level enum are offset by '2'
-    const int android_log_level = static_cast<int>(entry.log_level) + 2;
-    __android_log_print(android_log_level, "CitraNative", "%s", str.c_str());
-#else
     fputs(str.c_str(), stderr);
-#endif
 }
 
 void PrintColoredMessage(const Entry& entry) {
@@ -78,7 +72,7 @@ void PrintColoredMessage(const Entry& entry) {
     }
 
     SetConsoleTextAttribute(console_handle, color);
-#elif !defined(ANDROID)
+#else
 #define ESC "\x1b"
     const char* color = "";
     switch (entry.log_level) {
@@ -111,9 +105,40 @@ void PrintColoredMessage(const Entry& entry) {
 
 #ifdef _WIN32
     SetConsoleTextAttribute(console_handle, original_info.wAttributes);
-#elif !defined(ANDROID)
+#else
     fputs(ESC "[0m", stderr);
 #undef ESC
 #endif
 }
+
+void PrintMessageToLogcat(const Entry& entry) {
+#ifdef ANDROID
+    const auto str = FormatLogMessage(entry);
+
+    android_LogPriority android_log_priority;
+    switch (entry.log_level) {
+        case Level::Trace:
+            android_log_priority = ANDROID_LOG_VERBOSE;
+            break;
+        case Level::Debug:
+            android_log_priority = ANDROID_LOG_DEBUG;
+            break;
+        case Level::Info:
+            android_log_priority = ANDROID_LOG_INFO;
+            break;
+        case Level::Warning:
+            android_log_priority = ANDROID_LOG_WARN;
+            break;
+        case Level::Error:
+            android_log_priority = ANDROID_LOG_ERROR;
+            break;
+        case Level::Critical:
+            android_log_priority = ANDROID_LOG_FATAL;
+            break;
+        case Level::Count:
+            UNREACHABLE();
+    }
+    __android_log_print(android_log_priority, "CitraNative", "%s", str.c_str());
+#endif
+}
 } // namespace Log

src/common/logging/text_formatter.h

@@ -17,4 +17,6 @@ std::string FormatLogMessage(const Entry& entry);
 void PrintMessage(const Entry& entry);
 /// Prints the same message as `PrintMessage`, but colored according to the severity level.
 void PrintColoredMessage(const Entry& entry);
+/// Formats and prints a log entry to the android logcat.
+void PrintMessageToLogcat(const Entry& entry);
 } // namespace Log