Logging: Add customizable logging backends and fmtlib based macros

* Change the logging backend to support multiple sinks through the
Backend Interface
* Add a new set of logging macros to use fmtlib instead.
* Qt: Compile as GUI application on windows to make the console hidden by
default. Add filter configuration and a button to open log location.
* SDL: Migrate to the new logging macros

src/citra/citra.cpp

@@ -25,6 +25,7 @@
 
 #include "citra/config.h"
 #include "citra/emu_window/emu_window_sdl2.h"
+#include "common/common_paths.h"
 #include "common/file_util.h"
 #include "common/logging/backend.h"
 #include "common/logging/filter.h"
@@ -60,39 +61,39 @@ static void PrintVersion() {
 static void OnStateChanged(const Network::RoomMember::State& state) {
     switch (state) {
     case Network::RoomMember::State::Idle:
-        LOG_DEBUG(Network, "Network is idle");
+        NGLOG_DEBUG(Network, "Network is idle");
         break;
     case Network::RoomMember::State::Joining:
-        LOG_DEBUG(Network, "Connection sequence to room started");
+        NGLOG_DEBUG(Network, "Connection sequence to room started");
         break;
     case Network::RoomMember::State::Joined:
-        LOG_DEBUG(Network, "Successfully joined to the room");
+        NGLOG_DEBUG(Network, "Successfully joined to the room");
         break;
     case Network::RoomMember::State::LostConnection:
-        LOG_DEBUG(Network, "Lost connection to the room");
+        NGLOG_DEBUG(Network, "Lost connection to the room");
         break;
     case Network::RoomMember::State::CouldNotConnect:
-        LOG_ERROR(Network, "State: CouldNotConnect");
+        NGLOG_ERROR(Network, "State: CouldNotConnect");
         exit(1);
         break;
     case Network::RoomMember::State::NameCollision:
-        LOG_ERROR(
+        NGLOG_ERROR(
             Network,
             "You tried to use the same nickname then another user that is connected to the Room");
         exit(1);
         break;
     case Network::RoomMember::State::MacCollision:
-        LOG_ERROR(Network, "You tried to use the same MAC-Address then another user that is "
+        NGLOG_ERROR(Network, "You tried to use the same MAC-Address then another user that is "
-                           "connected to the Room");
+                             "connected to the Room");
         exit(1);
         break;
     case Network::RoomMember::State::WrongPassword:
-        LOG_ERROR(Network, "Room replied with: Wrong password");
+        NGLOG_ERROR(Network, "Room replied with: Wrong password");
         exit(1);
         break;
     case Network::RoomMember::State::WrongVersion:
-        LOG_ERROR(Network,
+        NGLOG_ERROR(Network,
-                  "You are using a different version then the room you are trying to connect to");
+                    "You are using a different version then the room you are trying to connect to");
         exit(1);
         break;
     default:
@@ -119,7 +120,7 @@ int main(int argc, char** argv) {
     auto argv_w = CommandLineToArgvW(GetCommandLineW(), &argc_w);
 
     if (argv_w == nullptr) {
-        LOG_CRITICAL(Frontend, "Failed to get command line arguments");
+        NGLOG_CRITICAL(Frontend, "Failed to get command line arguments");
         return -1;
     }
 #endif
@@ -155,7 +156,7 @@ int main(int argc, char** argv) {
                 break;
             case 'i': {
                 const auto cia_progress = [](size_t written, size_t total) {
-                    LOG_INFO(Frontend, "%02zu%%", (written * 100 / total));
+                    NGLOG_INFO(Frontend, "{:02d}%", (written * 100 / total));
                 };
                 if (Service::AM::InstallCIA(std::string(optarg), cia_progress) !=
                     Service::AM::InstallStatus::Success)
@@ -223,23 +224,27 @@ int main(int argc, char** argv) {
     LocalFree(argv_w);
 #endif
 
-    Log::Filter log_filter(Log::Level::Debug);
-    Log::SetFilter(&log_filter);
-
     MicroProfileOnThreadCreate("EmuThread");
     SCOPE_EXIT({ MicroProfileShutdown(); });
 
     if (filepath.empty()) {
-        LOG_CRITICAL(Frontend, "Failed to load ROM: No ROM specified");
+        NGLOG_CRITICAL(Frontend, "Failed to load ROM: No ROM specified");
         return -1;
     }
 
     if (!movie_record.empty() && !movie_play.empty()) {
-        LOG_CRITICAL(Frontend, "Cannot both play and record a movie");
+        NGLOG_CRITICAL(Frontend, "Cannot both play and record a movie");
         return -1;
     }
 
+    Log::Filter log_filter;
     log_filter.ParseFilterString(Settings::values.log_filter);
+    Log::SetGlobalFilter(log_filter);
+
+    Log::AddBackend(std::make_unique<Log::ColorConsoleBackend>());
+    FileUtil::CreateFullPath(FileUtil::GetUserPath(D_LOGS_IDX));
+    Log::AddBackend(
+        std::make_unique<Log::FileBackend>(FileUtil::GetUserPath(D_LOGS_IDX) + LOG_FILE));
 
     // Apply the command line arguments
     Settings::values.gdbstub_port = gdb_port;
@@ -258,28 +263,28 @@ int main(int argc, char** argv) {
 
     switch (load_result) {
     case Core::System::ResultStatus::ErrorGetLoader:
-        LOG_CRITICAL(Frontend, "Failed to obtain loader for %s!", filepath.c_str());
+        NGLOG_CRITICAL(Frontend, "Failed to obtain loader for {}!", filepath);
         return -1;
     case Core::System::ResultStatus::ErrorLoader:
-        LOG_CRITICAL(Frontend, "Failed to load ROM!");
+        NGLOG_CRITICAL(Frontend, "Failed to load ROM!");
         return -1;
     case Core::System::ResultStatus::ErrorLoader_ErrorEncrypted:
-        LOG_CRITICAL(Frontend, "The game that you are trying to load must be decrypted before "
+        NGLOG_CRITICAL(Frontend, "The game that you are trying to load must be decrypted before "
-                               "being used with Citra. \n\n For more information on dumping and "
+                                 "being used with Citra. \n\n For more information on dumping and "
-                               "decrypting games, please refer to: "
+                                 "decrypting games, please refer to: "
-                               "https://citra-emu.org/wiki/dumping-game-cartridges/");
+                                 "https://citra-emu.org/wiki/dumping-game-cartridges/");
         return -1;
     case Core::System::ResultStatus::ErrorLoader_ErrorInvalidFormat:
-        LOG_CRITICAL(Frontend, "Error while loading ROM: The ROM format is not supported.");
+        NGLOG_CRITICAL(Frontend, "Error while loading ROM: The ROM format is not supported.");
         return -1;
     case Core::System::ResultStatus::ErrorNotInitialized:
-        LOG_CRITICAL(Frontend, "CPUCore not initialized");
+        NGLOG_CRITICAL(Frontend, "CPUCore not initialized");
         return -1;
     case Core::System::ResultStatus::ErrorSystemMode:
-        LOG_CRITICAL(Frontend, "Failed to determine system mode!");
+        NGLOG_CRITICAL(Frontend, "Failed to determine system mode!");
         return -1;
     case Core::System::ResultStatus::ErrorVideoCore:
-        LOG_CRITICAL(Frontend, "VideoCore not initialized");
+        NGLOG_CRITICAL(Frontend, "VideoCore not initialized");
         return -1;
     case Core::System::ResultStatus::Success:
         break; // Expected case
@@ -291,11 +296,11 @@ int main(int argc, char** argv) {
         if (auto member = Network::GetRoomMember().lock()) {
             member->BindOnChatMessageRecieved(OnMessageReceived);
             member->BindOnStateChanged(OnStateChanged);
-            LOG_DEBUG(Network, "Start connection to %s:%u with nickname %s", address.c_str(), port,
+            NGLOG_DEBUG(Network, "Start connection to {}:{} with nickname {}", address, port,
-                      nickname.c_str());
+                        nickname);
             member->Join(nickname, address.c_str(), port, 0, Network::NoPreferredMac, password);
         } else {
-            LOG_ERROR(Network, "Could not access RoomMember");
+            NGLOG_ERROR(Network, "Could not access RoomMember");
             return 0;
         }
     }

src/citra/config.cpp

@@ -27,17 +27,17 @@ bool Config::LoadINI(const std::string& default_contents, bool retry) {
     const char* location = this->sdl2_config_loc.c_str();
     if (sdl2_config->ParseError() < 0) {
         if (retry) {
-            LOG_WARNING(Config, "Failed to load %s. Creating file from defaults...", location);
+            NGLOG_WARNING(Config, "Failed to load {}. Creating file from defaults...", location);
             FileUtil::CreateFullPath(location);
             FileUtil::WriteStringToFile(true, default_contents, location);
             sdl2_config = std::make_unique<INIReader>(location); // Reopen file
 
             return LoadINI(default_contents, false);
         }
-        LOG_ERROR(Config, "Failed.");
+        NGLOG_ERROR(Config, "Failed.");
         return false;
     }
-    LOG_INFO(Config, "Successfully loaded %s", location);
+    NGLOG_INFO(Config, "Successfully loaded {}", location);
     return true;
 }
 
@@ -49,10 +49,18 @@ static const std::array<int, Settings::NativeButton::NumButtons> default_buttons
 
 static const std::array<std::array<int, 5>, Settings::NativeAnalog::NumAnalogs> default_analogs{{
     {
-        SDL_SCANCODE_UP, SDL_SCANCODE_DOWN, SDL_SCANCODE_LEFT, SDL_SCANCODE_RIGHT, SDL_SCANCODE_D,
+        SDL_SCANCODE_UP,
+        SDL_SCANCODE_DOWN,
+        SDL_SCANCODE_LEFT,
+        SDL_SCANCODE_RIGHT,
+        SDL_SCANCODE_D,
     },
     {
-        SDL_SCANCODE_I, SDL_SCANCODE_K, SDL_SCANCODE_J, SDL_SCANCODE_L, SDL_SCANCODE_D,
+        SDL_SCANCODE_I,
+        SDL_SCANCODE_K,
+        SDL_SCANCODE_J,
+        SDL_SCANCODE_L,
+        SDL_SCANCODE_D,
     },
 }};
 

src/citra/emu_window/emu_window_sdl2.cpp

@@ -66,7 +66,7 @@ EmuWindow_SDL2::EmuWindow_SDL2() {
 
     // Initialize the window
     if (SDL_Init(SDL_INIT_VIDEO) < 0) {
-        LOG_CRITICAL(Frontend, "Failed to initialize SDL2! Exiting...");
+        NGLOG_CRITICAL(Frontend, "Failed to initialize SDL2! Exiting...");
         exit(1);
     }
 
@@ -89,19 +89,19 @@ EmuWindow_SDL2::EmuWindow_SDL2() {
                          SDL_WINDOW_OPENGL | SDL_WINDOW_RESIZABLE | SDL_WINDOW_ALLOW_HIGHDPI);
 
     if (render_window == nullptr) {
-        LOG_CRITICAL(Frontend, "Failed to create SDL2 window: %s", SDL_GetError());
+        NGLOG_CRITICAL(Frontend, "Failed to create SDL2 window: {}", SDL_GetError());
         exit(1);
     }
 
     gl_context = SDL_GL_CreateContext(render_window);
 
     if (gl_context == nullptr) {
-        LOG_CRITICAL(Frontend, "Failed to create SDL2 GL context: %s", SDL_GetError());
+        NGLOG_CRITICAL(Frontend, "Failed to create SDL2 GL context: {}", SDL_GetError());
         exit(1);
     }
 
     if (!gladLoadGLLoader(static_cast<GLADloadproc>(SDL_GL_GetProcAddress))) {
-        LOG_CRITICAL(Frontend, "Failed to initialize GL functions: %s", SDL_GetError());
+        NGLOG_CRITICAL(Frontend, "Failed to initialize GL functions: {}", SDL_GetError());
         exit(1);
     }
 

src/citra_qt/CMakeLists.txt

@@ -28,6 +28,8 @@ add_executable(citra-qt
     configuration/configure_system.h
     configuration/configure_web.cpp
     configuration/configure_web.h
+    debugger/console.h
+    debugger/console.cpp
     debugger/graphics/graphics.cpp
     debugger/graphics/graphics.h
     debugger/graphics/graphics_breakpoint_observer.cpp
@@ -138,6 +140,10 @@ if (APPLE)
     target_sources(citra-qt PRIVATE ${MACOSX_ICON})
     set_target_properties(citra-qt PROPERTIES MACOSX_BUNDLE TRUE)
     set_target_properties(citra-qt PROPERTIES MACOSX_BUNDLE_INFO_PLIST ${CMAKE_CURRENT_SOURCE_DIR}/Info.plist)
+elseif(WIN32)
+    # compile as a win32 gui application instead of a console application
+    target_link_libraries(citra-qt PRIVATE Qt5::WinMain)
+    set_target_properties(citra-qt PROPERTIES LINK_FLAGS_RELEASE "/SUBSYSTEM:WINDOWS")
 endif()
 
 create_target_directory_groups(citra-qt)

src/citra_qt/configuration/config.cpp

@@ -24,10 +24,18 @@ const std::array<int, Settings::NativeButton::NumButtons> Config::default_button
 
 const std::array<std::array<int, 5>, Settings::NativeAnalog::NumAnalogs> Config::default_analogs{{
     {
-        Qt::Key_Up, Qt::Key_Down, Qt::Key_Left, Qt::Key_Right, Qt::Key_D,
+        Qt::Key_Up,
+        Qt::Key_Down,
+        Qt::Key_Left,
+        Qt::Key_Right,
+        Qt::Key_D,
     },
     {
-        Qt::Key_I, Qt::Key_K, Qt::Key_J, Qt::Key_L, Qt::Key_D,
+        Qt::Key_I,
+        Qt::Key_K,
+        Qt::Key_J,
+        Qt::Key_L,
+        Qt::Key_D,
     },
 }};
 
@@ -216,6 +224,7 @@ void Config::ReadValues() {
     UISettings::values.confirm_before_closing = qt_config->value("confirmClose", true).toBool();
     UISettings::values.first_start = qt_config->value("firstStart", true).toBool();
     UISettings::values.callout_flags = qt_config->value("calloutFlags", 0).toUInt();
+    UISettings::values.show_console = qt_config->value("showConsole", false).toBool();
 
     qt_config->endGroup();
 }
@@ -357,6 +366,7 @@ void Config::SaveValues() {
     qt_config->setValue("confirmClose", UISettings::values.confirm_before_closing);
     qt_config->setValue("firstStart", UISettings::values.first_start);
     qt_config->setValue("calloutFlags", UISettings::values.callout_flags);
+    qt_config->setValue("showConsole", UISettings::values.show_console);
 
     qt_config->endGroup();
 }

src/citra_qt/configuration/configure_debug.cpp

@@ -2,13 +2,27 @@
 // Licensed under GPLv2 or any later version
 // Refer to the license.txt file included.
 
+#include <QDesktopServices>
+#include <QUrl>
+
 #include "citra_qt/configuration/configure_debug.h"
+#include "citra_qt/debugger/console.h"
+#include "citra_qt/ui_settings.h"
+#include "common/file_util.h"
+#include "common/logging/backend.h"
+#include "common/logging/filter.h"
+#include "common/logging/log.h"
+#include "core/core.h"
 #include "core/settings.h"
 #include "ui_configure_debug.h"
 
 ConfigureDebug::ConfigureDebug(QWidget* parent) : QWidget(parent), ui(new Ui::ConfigureDebug) {
     ui->setupUi(this);
     this->setConfiguration();
+    connect(ui->open_log_button, &QPushButton::pressed, []() {
+        QString path = QString::fromStdString(FileUtil::GetUserPath(D_LOGS_IDX));
+        QDesktopServices::openUrl(QUrl::fromLocalFile(path));
+    });
 }
 
 ConfigureDebug::~ConfigureDebug() {}
@@ -17,11 +31,20 @@ void ConfigureDebug::setConfiguration() {
     ui->toggle_gdbstub->setChecked(Settings::values.use_gdbstub);
     ui->gdbport_spinbox->setEnabled(Settings::values.use_gdbstub);
     ui->gdbport_spinbox->setValue(Settings::values.gdbstub_port);
+    ui->toggle_console->setEnabled(!Core::System::GetInstance().IsPoweredOn());
+    ui->toggle_console->setChecked(UISettings::values.show_console);
+    ui->log_filter_edit->setText(QString::fromStdString(Settings::values.log_filter));
 }
 
 void ConfigureDebug::applyConfiguration() {
     Settings::values.use_gdbstub = ui->toggle_gdbstub->isChecked();
     Settings::values.gdbstub_port = ui->gdbport_spinbox->value();
+    UISettings::values.show_console = ui->toggle_console->isChecked();
+    Settings::values.log_filter = ui->log_filter_edit->text().toStdString();
+    Debugger::ToggleConsole();
+    Log::Filter filter;
+    filter.ParseFilterString(Settings::values.log_filter);
+    Log::SetGlobalFilter(filter);
     Settings::Apply();
 }
 

src/citra_qt/configuration/configure_debug.ui

@@ -72,6 +72,47 @@
      </item>
     </layout>
    </item>
+   <item>
+    <widget class="QGroupBox" name="groupBox_2">
+     <property name="title">
+      <string>Logging</string>
+     </property>
+     <layout class="QVBoxLayout" name="verticalLayout">
+      <item>
+       <layout class="QHBoxLayout" name="horizontalLayout">
+        <item>
+         <widget class="QLabel" name="label">
+          <property name="text">
+           <string>Global Log Filter</string>
+          </property>
+         </widget>
+        </item>
+        <item>
+         <widget class="QLineEdit" name="log_filter_edit"/>
+        </item>
+       </layout>
+      </item>
+      <item>
+       <layout class="QHBoxLayout" name="horizontalLayout_2">
+        <item>
+         <widget class="QCheckBox" name="toggle_console">
+          <property name="text">
+           <string>Show Log Console (Windows Only)</string>
+          </property>
+         </widget>
+        </item>
+        <item>
+         <widget class="QPushButton" name="open_log_button">
+          <property name="text">
+           <string>Open Log Location</string>
+          </property>
+         </widget>
+        </item>
+       </layout>
+      </item>
+     </layout>
+    </widget>
+   </item>
    <item>
     <spacer name="verticalSpacer">
      <property name="orientation">

src/citra_qt/debugger/console.cpp

@@ -0,0 +1,34 @@
+// Copyright 2018 Citra Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#ifdef _WIN32
+#include <windows.h>
+
+#include <wincon.h>
+#endif
+
+#include "citra_qt/debugger/console.h"
+#include "citra_qt/ui_settings.h"
+
+namespace Debugger {
+void ToggleConsole() {
+#ifdef _WIN32
+    if (UISettings::values.show_console) {
+        if (AllocConsole()) {
+            freopen_s((FILE**)stdin, "CONIN$", "r", stdin);
+            freopen_s((FILE**)stdout, "CONOUT$", "w", stdout);
+            freopen_s((FILE**)stderr, "CONOUT$", "w", stderr);
+        }
+    } else {
+        if (FreeConsole()) {
+            // In order to close the console, we have to also detach the streams on it.
+            // Just redirect them to NUL if there is no console window
+            freopen_s((FILE**)stdin, "NUL", "r", stdin);
+            freopen_s((FILE**)stdout, "NUL", "w", stdout);
+            freopen_s((FILE**)stderr, "NUL", "w", stderr);
+        }
+    }
+#endif
+}
+} // namespace Debugger

src/citra_qt/debugger/console.h

@@ -0,0 +1,14 @@
+// Copyright 2018 Citra Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+namespace Debugger {
+
+/**
+ * Uses the WINAPI to hide or show the stderr console. This function is a placeholder until we can
+ * get a real qt logging window which would work for all platforms.
+ */
+void ToggleConsole();
+} // namespace Debugger

src/citra_qt/main.cpp

@@ -20,6 +20,7 @@
 #include "citra_qt/compatdb.h"
 #include "citra_qt/configuration/config.h"
 #include "citra_qt/configuration/configure_dialog.h"
+#include "citra_qt/debugger/console.h"
 #include "citra_qt/debugger/graphics/graphics.h"
 #include "citra_qt/debugger/graphics/graphics_breakpoints.h"
 #include "citra_qt/debugger/graphics/graphics_cmdlists.h"
@@ -34,6 +35,7 @@
 #include "citra_qt/main.h"
 #include "citra_qt/ui_settings.h"
 #include "citra_qt/updater/updater.h"
+#include "common/common_paths.h"
 #include "common/logging/backend.h"
 #include "common/logging/filter.h"
 #include "common/logging/log.h"
@@ -369,6 +371,7 @@ void GMainWindow::RestoreUIState() {
 
     ui.action_Show_Status_Bar->setChecked(UISettings::values.show_status_bar);
     statusBar()->setVisible(ui.action_Show_Status_Bar->isChecked());
+    Debugger::ToggleConsole();
 }
 
 void GMainWindow::ConnectWidgetEvents() {
@@ -1295,8 +1298,7 @@ void GMainWindow::SyncMenuUISettings() {
 #endif
 
 int main(int argc, char* argv[]) {
-    Log::Filter log_filter(Log::Level::Info);
+    Log::AddBackend(std::make_unique<Log::ColorConsoleBackend>());
-    Log::SetFilter(&log_filter);
 
     MicroProfileOnThreadCreate("Frontend");
     SCOPE_EXIT({ MicroProfileShutdown(); });
@@ -1314,7 +1316,12 @@ int main(int argc, char* argv[]) {
 
     GMainWindow main_window;
     // After settings have been loaded by GMainWindow, apply the filter
+    Log::Filter log_filter;
     log_filter.ParseFilterString(Settings::values.log_filter);
+    Log::SetGlobalFilter(log_filter);
+    FileUtil::CreateFullPath(FileUtil::GetUserPath(D_LOGS_IDX));
+    Log::AddBackend(
+        std::make_unique<Log::FileBackend>(FileUtil::GetUserPath(D_LOGS_IDX) + LOG_FILE));
 
     main_window.show();
     return app.exec();

src/citra_qt/ui_settings.h

@@ -56,6 +56,8 @@ struct Values {
     std::vector<Shortcut> shortcuts;
 
     uint32_t callout_flags;
+
+    bool show_console;
 };
 
 extern Values values;

src/common/CMakeLists.txt

@@ -93,7 +93,7 @@ endif()
 
 create_target_directory_groups(common)
 
-target_link_libraries(common PUBLIC Boost::boost microprofile)
+target_link_libraries(common PUBLIC Boost::boost fmt microprofile)
 if (ARCHITECTURE_x86_64)
     target_link_libraries(common PRIVATE xbyak)
 endif()

src/common/common_paths.h

@@ -36,8 +36,12 @@
 #define SDMC_DIR "sdmc"
 #define NAND_DIR "nand"
 #define SYSDATA_DIR "sysdata"
+#define LOG_DIR "log"
 
 // Filenames
+// Files in the directory returned by GetUserPath(D_LOGS_IDX)
+#define LOG_FILE "citra_log.txt"
+
 // Files in the directory returned by GetUserPath(D_CONFIG_IDX)
 #define EMU_CONFIG "emu.ini"
 #define DEBUGGER_CONFIG "debugger.ini"

src/common/file_util.cpp

@@ -715,6 +715,8 @@ const std::string& GetUserPath(const unsigned int DirIDX, const std::string& new
         paths[D_SDMC_IDX] = paths[D_USER_IDX] + SDMC_DIR DIR_SEP;
         paths[D_NAND_IDX] = paths[D_USER_IDX] + NAND_DIR DIR_SEP;
         paths[D_SYSDATA_IDX] = paths[D_USER_IDX] + SYSDATA_DIR DIR_SEP;
+        // TODO: Put the logs in a better location for each OS
+        paths[D_LOGS_IDX] = paths[D_USER_IDX] + LOG_DIR DIR_SEP;
     }
 
     if (!newPath.empty()) {
@@ -873,20 +875,19 @@ bool IOFile::Flush() {
 }
 
 bool IOFile::Resize(u64 size) {
-    if (!IsOpen() ||
+    if (!IsOpen() || 0 !=
-        0 !=
 #ifdef _WIN32
-            // ector: _chsize sucks, not 64-bit safe
+                         // ector: _chsize sucks, not 64-bit safe
-            // F|RES: changed to _chsize_s. i think it is 64-bit safe
+                         // F|RES: changed to _chsize_s. i think it is 64-bit safe
-            _chsize_s(_fileno(m_file), size)
+                         _chsize_s(_fileno(m_file), size)
 #else
-            // TODO: handle 64bit and growing
+                         // TODO: handle 64bit and growing
-            ftruncate(fileno(m_file), size)
+                         ftruncate(fileno(m_file), size)
 #endif
-            )
+    )
         m_good = false;
 
     return m_good;
 }
 
-} // namespace
+} // namespace FileUtil

src/common/file_util.h

@@ -224,6 +224,10 @@ public:
         return WriteArray(&object, 1);
     }
 
+    size_t WriteString(const std::string& str) {
+        return WriteArray(str.c_str(), str.length());
+    }
+
     bool IsOpen() const {
         return nullptr != m_file;
     }
@@ -253,7 +257,7 @@ private:
     bool m_good = true;
 };
 
-} // namespace
+} // namespace FileUtil
 
 // To deal with Windows being dumb at unicode:
 template <typename T>

src/common/logging/backend.cpp

@@ -4,16 +4,108 @@
 
 #include <algorithm>
 #include <array>
+#include <chrono>
 #include <cstdio>
+#include <future>
+#include <memory>
+#include <thread>
 #include "common/assert.h"
 #include "common/common_funcs.h" // snprintf compatibility define
 #include "common/logging/backend.h"
-#include "common/logging/filter.h"
 #include "common/logging/log.h"
 #include "common/logging/text_formatter.h"
+#include "common/string_util.h"
+#include "common/threadsafe_queue.h"
 
 namespace Log {
 
+/**
+ * Static state as a singleton.
+ */
+class Impl {
+public:
+    static Impl& Instance() {
+        static Impl backend;
+        return backend;
+    }
+
+    Impl(Impl const&) = delete;
+    const Impl& operator=(Impl const&) = delete;
+
+    Common::MPSCQueue<Log::Entry>& GetQueue() {
+        return message_queue;
+    }
+
+    void AddBackend(std::unique_ptr<Backend> backend) {
+        backends.push_back(std::move(backend));
+    }
+
+    void RemoveBackend(const std::string& backend_name) {
+        std::remove_if(backends.begin(), backends.end(),
+                       [&backend_name](const auto& i) { return i->GetName() == backend_name; });
+    }
+
+    const Filter& GetGlobalFilter() const {
+        return filter;
+    }
+
+    void SetGlobalFilter(const Filter& f) {
+        filter = f;
+    }
+
+    Backend* GetBackend(const std::string& backend_name) {
+        auto it = std::find_if(backends.begin(), backends.end(), [&backend_name](const auto& i) {
+            return i->GetName() == backend_name;
+        });
+        if (it == backends.end())
+            return nullptr;
+        return it->get();
+    }
+
+private:
+    Impl() : running(true) {
+        backend_thread = std::async(std::launch::async, [&] {
+            using namespace std::chrono_literals;
+            Entry entry;
+            while (running) {
+                if (!message_queue.Pop(entry)) {
+                    std::this_thread::sleep_for(1ms);
+                    continue;
+                }
+                for (const auto& backend : backends) {
+                    backend->Write(entry);
+                }
+            }
+        });
+    }
+    ~Impl() {
+        if (running) {
+            running = false;
+        }
+    }
+
+    std::atomic_bool running;
+    std::future<void> backend_thread;
+    std::vector<std::unique_ptr<Backend>> backends;
+    Common::MPSCQueue<Log::Entry> message_queue;
+    Filter filter;
+};
+
+void ConsoleBackend::Write(const Entry& entry) {
+    PrintMessage(entry);
+}
+
+void ColorConsoleBackend::Write(const Entry& entry) {
+    PrintColoredMessage(entry);
+}
+
+void FileBackend::Write(const Entry& entry) {
+    if (!file.IsOpen()) {
+        return;
+    }
+    file.WriteString(FormatLogMessage(entry) + "\n");
+}
+
 /// Macro listing all log classes. Code should define CLS and SUB as desired before invoking this.
 #define ALL_LOG_CLASSES()                                                                          \
     CLS(Log)                                                                                       \
@@ -113,45 +205,65 @@ const char* GetLevelName(Level log_level) {
 }
 
 Entry CreateEntry(Class log_class, Level log_level, const char* filename, unsigned int line_nr,
-                  const char* function, const char* format, va_list args) {
+                  const char* function, const std::string& message) {
-    using std::chrono::steady_clock;
     using std::chrono::duration_cast;
+    using std::chrono::steady_clock;
 
     static steady_clock::time_point time_origin = steady_clock::now();
 
-    std::array<char, 4 * 1024> formatting_buffer;
-
     Entry entry;
     entry.timestamp = duration_cast<std::chrono::microseconds>(steady_clock::now() - time_origin);
     entry.log_class = log_class;
     entry.log_level = log_level;
-
+    entry.filename = std::string(Common::TrimSourcePath(filename));
-    snprintf(formatting_buffer.data(), formatting_buffer.size(), "%s:%s:%u", filename, function,
+    entry.line_num = line_nr;
-             line_nr);
+    entry.function = std::string(function);
-    entry.location = std::string(formatting_buffer.data());
+    entry.message = message;
-
-    vsnprintf(formatting_buffer.data(), formatting_buffer.size(), format, args);
-    entry.message = std::string(formatting_buffer.data());
 
     return entry;
 }
 
-static Filter* filter = nullptr;
+void SetGlobalFilter(const Filter& filter) {
-
+    Impl::Instance().SetGlobalFilter(filter);
-void SetFilter(Filter* new_filter) {
-    filter = new_filter;
 }
 
-void LogMessage(Class log_class, Level log_level, const char* filename, unsigned int line_nr,
+void AddBackend(std::unique_ptr<Backend> backend) {
-                const char* function, const char* format, ...) {
+    Impl::Instance().AddBackend(std::move(backend));
-    if (filter != nullptr && !filter->CheckMessage(log_class, log_level))
+}
-        return;
 
+void RemoveBackend(const std::string& backend_name) {
+    Impl::Instance().RemoveBackend(backend_name);
+}
+
+Backend* GetBackend(const std::string& backend_name) {
+    return Impl::Instance().GetBackend(backend_name);
+}
+
+void LogMessage(Class log_class, Level log_level, const char* filename, unsigned int line_num,
+                const char* function, const char* format, ...) {
+    auto filter = Impl::Instance().GetGlobalFilter();
+    if (!filter.CheckMessage(log_class, log_level))
+        return;
+    std::array<char, 4 * 1024> formatting_buffer;
     va_list args;
     va_start(args, format);
-    Entry entry = CreateEntry(log_class, log_level, filename, line_nr, function, format, args);
+    vsnprintf(formatting_buffer.data(), formatting_buffer.size(), format, args);
     va_end(args);
+    Entry entry = CreateEntry(log_class, log_level, filename, line_num, function,
+                              std::string(formatting_buffer.data()));
 
-    PrintColoredMessage(entry);
+    Impl::Instance().GetQueue().Push(std::move(entry));
 }
+
+void FmtLogMessage(Class log_class, Level log_level, const char* filename, unsigned int line_num,
+                   const char* function, const char* format, fmt::ArgList args) {
+    auto filter = Impl::Instance().GetGlobalFilter();
+    if (!filter.CheckMessage(log_class, log_level))
+        return;
+
+    Entry entry =
+        CreateEntry(log_class, log_level, filename, line_num, function, fmt::format(format, args));
+
+    Impl::Instance().GetQueue().Push(std::move(entry));
 }
+} // namespace Log

src/common/logging/backend.h

@@ -6,8 +6,11 @@
 
 #include <chrono>
 #include <cstdarg>
+#include <memory>
 #include <string>
 #include <utility>
+#include "common/file_util.h"
+#include "common/logging/filter.h"
 #include "common/logging/log.h"
 
 namespace Log {
@@ -22,15 +25,80 @@ struct Entry {
     std::chrono::microseconds timestamp;
     Class log_class;
     Level log_level;
-    std::string location;
+    std::string filename;
+    unsigned int line_num;
+    std::string function;
     std::string message;
 
     Entry() = default;
     Entry(Entry&& o) = default;
 
     Entry& operator=(Entry&& o) = default;
+    Entry& operator=(const Entry& o) = default;
 };
 
+/**
+ * Interface for logging backends. As loggers can be created and removed at runtime, this can be
+ * used by a frontend for adding a custom logging backend as needed
+ */
+class Backend {
+public:
+    virtual ~Backend() = default;
+    virtual void SetFilter(const Filter& new_filter) {
+        filter = new_filter;
+    }
+    virtual const char* GetName() const = 0;
+    virtual void Write(const Entry& entry) = 0;
+
+private:
+    Filter filter;
+};
+
+/**
+ * Backend that writes to stderr without any color commands
+ */
+class ConsoleBackend : public Backend {
+public:
+    const char* GetName() const override {
+        return "console";
+    }
+    void Write(const Entry& entry) override;
+};
+
+/**
+ * Backend that writes to stderr and with color
+ */
+class ColorConsoleBackend : public Backend {
+public:
+    const char* GetName() const override {
+        return "color_console";
+    }
+    void Write(const Entry& entry) override;
+};
+
+/**
+ * Backend that writes to a file passed into the constructor
+ */
+class FileBackend : public Backend {
+public:
+    FileBackend(const std::string& filename) : file(filename, "w") {}
+
+    const char* GetName() const override {
+        return "file";
+    }
+
+    void Write(const Entry& entry) override;
+
+private:
+    FileUtil::IOFile file;
+};
+
+void AddBackend(std::unique_ptr<Backend> backend);
+
+void RemoveBackend(const std::string& backend_name);
+
+Backend* GetBackend(const std::string& backend_name);
+
 /**
  * Returns the name of the passed log class as a C-string. Subclasses are separated by periods
  * instead of underscores as in the enumeration.
@@ -44,7 +112,13 @@ const char* GetLevelName(Level log_level);
 
 /// Creates a log entry by formatting the given source location, and message.
 Entry CreateEntry(Class log_class, Level log_level, const char* filename, unsigned int line_nr,
-                  const char* function, const char* format, va_list args);
+                  const char* function, const char* format, const std::string& message);
 
-void SetFilter(Filter* filter);
+/**
-}
+ * The global filter will prevent any messages from even being processed if they are filtered. Each
+ * backend can have a filter, but if the level is lower than the global filter, the backend will
+ * never get the message
+ */
+void SetGlobalFilter(const Filter& filter);
+
+} // namespace Log

src/common/logging/filter.h

@@ -19,7 +19,7 @@ namespace Log {
 class Filter {
 public:
     /// Initializes the filter with all classes having `default_level` as the minimum level.
-    Filter(Level default_level);
+    Filter(Level default_level = Level::Info);
 
     /// Resets the filter so that all classes have `level` as the minimum displayed level.
     void ResetAll(Level level);
@@ -50,4 +50,4 @@ public:
 private:
     std::array<Level, (size_t)Class::Count> class_levels;
 };
-}
+} // namespace Log

src/common/logging/log.h

@@ -4,6 +4,7 @@
 
 #pragma once
 
+#include <fmt/format.h>
 #include "common/common_types.h"
 
 namespace Log {
@@ -98,7 +99,7 @@ enum class Class : ClassType {
 };
 
 /// Logs a message to the global logger.
-void LogMessage(Class log_class, Level log_level, const char* filename, unsigned int line_nr,
+void LogMessage(Class log_class, Level log_level, const char* filename, unsigned int line_num,
                 const char* function,
 #ifdef _MSC_VER
                 _Printf_format_string_
@@ -110,6 +111,12 @@ void LogMessage(Class log_class, Level log_level, const char* filename, unsigned
 #endif
     ;
 
+/// Logs a message to the global logger, this time with 100% moar fmtlib
+void FmtLogMessage(Class log_class, Level log_level, const char* filename, unsigned int line_num,
+                   const char* function, const char* format, fmt::ArgList);
+
+FMT_VARIADIC(void, FmtLogMessage, Class, Level, const char*, unsigned int, const char*, const char*)
+
 } // namespace Log
 
 #define LOG_GENERIC(log_class, log_level, ...)                                                     \
@@ -132,3 +139,28 @@ void LogMessage(Class log_class, Level log_level, const char* filename, unsigned
     LOG_GENERIC(::Log::Class::log_class, ::Log::Level::Error, __VA_ARGS__)
 #define LOG_CRITICAL(log_class, ...)                                                               \
     LOG_GENERIC(::Log::Class::log_class, ::Log::Level::Critical, __VA_ARGS__)
+
+// Define the fmt lib macros
+#ifdef _DEBUG
+#define NGLOG_TRACE(log_class, fmt, ...)                                                           \
+    ::Log::FmtLogMessage(::Log::Class::log_class, ::Log::Level::Trace, __FILE__, __LINE__,         \
+                         __func__, fmt, ##__VA_ARGS__)
+#else
+#define NGLOG_TRACE(log_class, fmt, ...) (void(0))
+#endif
+
+#define NGLOG_DEBUG(log_class, fmt, ...)                                                           \
+    ::Log::FmtLogMessage(::Log::Class::log_class, ::Log::Level::Debug, __FILE__, __LINE__,         \
+                         __func__, fmt, ##__VA_ARGS__)
+#define NGLOG_INFO(log_class, fmt, ...)                                                            \
+    ::Log::FmtLogMessage(::Log::Class::log_class, ::Log::Level::Info, __FILE__, __LINE__,          \
+                         __func__, fmt, ##__VA_ARGS__)
+#define NGLOG_WARNING(log_class, fmt, ...)                                                         \
+    ::Log::FmtLogMessage(::Log::Class::log_class, ::Log::Level::Warning, __FILE__, __LINE__,       \
+                         __func__, fmt, ##__VA_ARGS__)
+#define NGLOG_ERROR(log_class, fmt, ...)                                                           \
+    ::Log::FmtLogMessage(::Log::Class::log_class, ::Log::Level::Error, __FILE__, __LINE__,         \
+                         __func__, fmt, ##__VA_ARGS__)
+#define NGLOG_CRITICAL(log_class, fmt, ...)                                                        \
+    ::Log::FmtLogMessage(::Log::Class::log_class, ::Log::Level::Critical, __FILE__, __LINE__,      \
+                         __func__, fmt, ##__VA_ARGS__)

src/common/logging/text_formatter.cpp

@@ -18,50 +18,26 @@
 
 namespace Log {
 
-// TODO(bunnei): This should be moved to a generic path manipulation library
+std::string FormatLogMessage(const Entry& entry) {
-const char* TrimSourcePath(const char* path, const char* root) {
-    const char* p = path;
-
-    while (*p != '\0') {
-        const char* next_slash = p;
-        while (*next_slash != '\0' && *next_slash != '/' && *next_slash != '\\') {
-            ++next_slash;
-        }
-
-        bool is_src = Common::ComparePartialString(p, next_slash, root);
-        p = next_slash;
-
-        if (*p != '\0') {
-            ++p;
-        }
-        if (is_src) {
-            path = p;
-        }
-    }
-    return path;
-}
-
-void FormatLogMessage(const Entry& entry, char* out_text, size_t text_len) {
     unsigned int time_seconds = static_cast<unsigned int>(entry.timestamp.count() / 1000000);
     unsigned int time_fractional = static_cast<unsigned int>(entry.timestamp.count() % 1000000);
 
     const char* class_name = GetLogClassName(entry.log_class);
     const char* level_name = GetLevelName(entry.log_level);
 
-    snprintf(out_text, text_len, "[%4u.%06u] %s <%s> %s: %s", time_seconds, time_fractional,
+    return fmt::format("[{:4d}.{:06d}] {} <{}> {}:{}:{}: {}", time_seconds, time_fractional,
-             class_name, level_name, TrimSourcePath(entry.location.c_str()), entry.message.c_str());
+                       class_name, level_name, entry.filename, entry.function, entry.line_num,
+                       entry.message);
 }
 
 void PrintMessage(const Entry& entry) {
-    std::array<char, 4 * 1024> format_buffer;
+    auto str = FormatLogMessage(entry) + "\n";
-    FormatLogMessage(entry, format_buffer.data(), format_buffer.size());
+    fputs(str.c_str(), stderr);
-    fputs(format_buffer.data(), stderr);
-    fputc('\n', stderr);
 }
 
 void PrintColoredMessage(const Entry& entry) {
 #ifdef _WIN32
-    static HANDLE console_handle = GetStdHandle(STD_ERROR_HANDLE);
+    HANDLE console_handle = GetStdHandle(STD_ERROR_HANDLE);
 
     CONSOLE_SCREEN_BUFFER_INFO original_info = {0};
     GetConsoleScreenBufferInfo(console_handle, &original_info);
@@ -129,4 +105,4 @@ void PrintColoredMessage(const Entry& entry) {
 #undef ESC
 #endif
 }
-}
+} // namespace Log

src/common/logging/text_formatter.h

@@ -10,22 +10,10 @@ namespace Log {
 
 struct Entry;
 
-/**
- * Attempts to trim an arbitrary prefix from `path`, leaving only the part starting at `root`. It's
- * intended to be used to strip a system-specific build directory from the `__FILE__` macro,
- * leaving only the path relative to the sources root.
- *
- * @param path The input file path as a null-terminated string
- * @param root The name of the root source directory as a null-terminated string. Path up to and
- *             including the last occurrence of this name will be stripped
- * @return A pointer to the same string passed as `path`, but starting at the trimmed portion
- */
-const char* TrimSourcePath(const char* path, const char* root = "src");
-
 /// Formats a log entry into the provided text buffer.
-void FormatLogMessage(const Entry& entry, char* out_text, size_t text_len);
+std::string FormatLogMessage(const Entry& entry);
 /// Formats and prints a log entry to stderr.
 void PrintMessage(const Entry& entry);
 /// Prints the same message as `PrintMessage`, but colored acoording to the severity level.
 void PrintColoredMessage(const Entry& entry);
-}
+} // namespace Log

src/common/string_util.cpp

@@ -202,7 +202,7 @@ bool SplitPath(const std::string& full_path, std::string* _pPath, std::string* _
 #ifdef _WIN32
                                             ":"
 #endif
-                                            );
+    );
     if (std::string::npos == dir_end)
         dir_end = 0;
     else
@@ -462,4 +462,26 @@ std::string StringFromFixedZeroTerminatedBuffer(const char* buffer, size_t max_l
 
     return std::string(buffer, len);
 }
+
+const char* TrimSourcePath(const char* path, const char* root) {
+    const char* p = path;
+
+    while (*p != '\0') {
+        const char* next_slash = p;
+        while (*next_slash != '\0' && *next_slash != '/' && *next_slash != '\\') {
+            ++next_slash;
+        }
+
+        bool is_src = Common::ComparePartialString(p, next_slash, root);
+        p = next_slash;
+
+        if (*p != '\0') {
+            ++p;
+        }
+        if (is_src) {
+            path = p;
+        }
+    }
+    return path;
 }
+} // namespace Common

src/common/string_util.h

@@ -134,4 +134,17 @@ bool ComparePartialString(InIt begin, InIt end, const char* other) {
  * NUL-terminated then the string ends at max_len characters.
  */
 std::string StringFromFixedZeroTerminatedBuffer(const char* buffer, size_t max_len);
-}
+
+/**
+ * Attempts to trim an arbitrary prefix from `path`, leaving only the part starting at `root`. It's
+ * intended to be used to strip a system-specific build directory from the `__FILE__` macro,
+ * leaving only the path relative to the sources root.
+ *
+ * @param path The input file path as a null-terminated string
+ * @param root The name of the root source directory as a null-terminated string. Path up to and
+ *             including the last occurrence of this name will be stripped
+ * @return A pointer to the same string passed as `path`, but starting at the trimmed portion
+ */
+const char* TrimSourcePath(const char* path, const char* root = "src");
+
+} // namespace Common

src/core/settings.cpp

@@ -4,14 +4,13 @@
 
 #include "audio_core/dsp_interface.h"
 #include "core/core.h"
+#include "core/frontend/emu_window.h"
 #include "core/gdbstub/gdbstub.h"
 #include "core/hle/service/hid/hid.h"
 #include "core/hle/service/ir/ir.h"
 #include "core/settings.h"
 #include "video_core/video_core.h"
 
-#include "core/frontend/emu_window.h"
-
 namespace Settings {
 
 Values values = {};

src/core/settings.h

@@ -54,9 +54,21 @@ constexpr int NUM_BUTTONS_IR = BUTTON_IR_END - BUTTON_IR_BEGIN;
 constexpr int NUM_BUTTONS_NS = BUTTON_NS_END - BUTTON_NS_BEGIN;
 
 static const std::array<const char*, NumButtons> mapping = {{
-    "button_a", "button_b", "button_x", "button_y", "button_up", "button_down", "button_left",
+    "button_a",
-    "button_right", "button_l", "button_r", "button_start", "button_select", "button_zl",
+    "button_b",
-    "button_zr", "button_home",
+    "button_x",
+    "button_y",
+    "button_up",
+    "button_down",
+    "button_left",
+    "button_right",
+    "button_l",
+    "button_r",
+    "button_start",
+    "button_select",
+    "button_zl",
+    "button_zr",
+    "button_home",
 }};
 } // namespace NativeButton
 
@@ -69,7 +81,8 @@ enum Values {
 };
 
 static const std::array<const char*, NumAnalogs> mapping = {{
-    "circle_pad", "c_stick",
+    "circle_pad",
+    "c_stick",
 }};
 } // namespace NativeAnalog
 
@@ -116,8 +129,6 @@ struct Values {
     float bg_green;
     float bg_blue;
 
-    std::string log_filter;
-
     // Audio
     std::string sink_id;
     bool enable_audio_stretching;
@@ -130,6 +141,7 @@ struct Values {
     // Debugging
     bool use_gdbstub;
     u16 gdbstub_port;
+    std::string log_filter;
 
     // Movie
     std::string movie_play;