Merge pull request #258 from yuriks/log-ng

New logging system

7 files changed, 760 insertions, 0 deletions

diff --git a/src/common/logging/backend.cpp b/src/common/logging/backend.cpp
new file mode 100644
index 00000000..e79b8460
--- /dev/null
+++ b/src/common/logging/backend.cpp
@@ -0,0 +1,151 @@
+// Copyright 2014 Citra Emulator Project
+// Licensed under GPLv2+
+// Refer to the license.txt file included.
+
+#include <algorithm>
+
+#include "common/log.h" // For _dbg_assert_
+
+#include "common/logging/backend.h"
+#include "common/logging/log.h"
+#include "common/logging/text_formatter.h"
+
+namespace Log {
+
+static std::shared_ptr<Logger> global_logger;
+
+/// Macro listing all log classes. Code should define CLS and SUB as desired before invoking this.
+#define ALL_LOG_CLASSES() \
+        CLS(Log) \
+        CLS(Common) \
+        SUB(Common, Filesystem) \
+        SUB(Common, Memory) \
+        CLS(Core) \
+        SUB(Core, ARM11) \
+        CLS(Config) \
+        CLS(Debug) \
+        SUB(Debug, Emulated) \
+        SUB(Debug, GPU) \
+        SUB(Debug, Breakpoint) \
+        CLS(Kernel) \
+        SUB(Kernel, SVC) \
+        CLS(Service) \
+        SUB(Service, SRV) \
+        SUB(Service, FS) \
+        SUB(Service, APT) \
+        SUB(Service, GSP) \
+        SUB(Service, AC) \
+        SUB(Service, PTM) \
+        SUB(Service, CFG) \
+        SUB(Service, DSP) \
+        SUB(Service, HID) \
+        CLS(HW) \
+        SUB(HW, Memory) \
+        SUB(HW, GPU) \
+        CLS(Frontend) \
+        CLS(Render) \
+        SUB(Render, Software) \
+        SUB(Render, OpenGL) \
+        CLS(Loader)
+
+Logger::Logger() {
+    // Register logging classes so that they can be queried at runtime
+    size_t parent_class;
+    all_classes.reserve((size_t)Class::Count);
+
+#define CLS(x) \
+        all_classes.push_back(Class::x); \
+        parent_class = all_classes.size() - 1;
+#define SUB(x, y) \
+        all_classes.push_back(Class::x##_##y); \
+        all_classes[parent_class].num_children += 1;
+
+    ALL_LOG_CLASSES()
+#undef CLS
+#undef SUB
+
+    // Ensures that ALL_LOG_CLASSES isn't missing any entries.
+    _dbg_assert_(Log, all_classes.size() == (size_t)Class::Count);
+}
+
+// GetClassName is a macro defined by Windows.h, grrr...
+const char* Logger::GetLogClassName(Class log_class) {
+    switch (log_class) {
+#define CLS(x) case Class::x: return #x;
+#define SUB(x, y) case Class::x##_##y: return #x "." #y;
+        ALL_LOG_CLASSES()
+#undef CLS
+#undef SUB
+    }
+    return "Unknown";
+}
+
+const char* Logger::GetLevelName(Level log_level) {
+#define LVL(x) case Level::x: return #x
+    switch (log_level) {
+        LVL(Trace);
+        LVL(Debug);
+        LVL(Info);
+        LVL(Warning);
+        LVL(Error);
+        LVL(Critical);
+    }
+    return "Unknown";
+#undef LVL
+}
+
+void Logger::LogMessage(Entry entry) {
+    ring_buffer.Push(std::move(entry));
+}
+
+size_t Logger::GetEntries(Entry* out_buffer, size_t buffer_len) {
+    return ring_buffer.BlockingPop(out_buffer, buffer_len);
+}
+
+std::shared_ptr<Logger> InitGlobalLogger() {
+    global_logger = std::make_shared<Logger>();
+    return global_logger;
+}
+
+Entry CreateEntry(Class log_class, Level log_level,
+                        const char* filename, unsigned int line_nr, const char* function,
+                        const char* format, va_list args) {
+    using std::chrono::steady_clock;
+    using std::chrono::duration_cast;
+
+    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;
+
+    snprintf(formatting_buffer.data(), formatting_buffer.size(), "%s:%s:%u", filename, function, line_nr);
+    entry.location = std::string(formatting_buffer.data());
+
+    vsnprintf(formatting_buffer.data(), formatting_buffer.size(), format, args);
+    entry.message = std::string(formatting_buffer.data());
+
+    return std::move(entry);
+}
+
+void LogMessage(Class log_class, Level log_level,
+                const char* filename, unsigned int line_nr, const char* function,
+                const char* format, ...) {
+    va_list args;
+    va_start(args, format);
+    Entry entry = CreateEntry(log_class, log_level,
+            filename, line_nr, function, format, args);
+    va_end(args);
+
+    if (global_logger != nullptr && !global_logger->IsClosed()) {
+        global_logger->LogMessage(std::move(entry));
+    } else {
+        // Fall back to directly printing to stderr
+        PrintMessage(entry);
+    }
+}
+
+}
diff --git a/src/common/logging/backend.h b/src/common/logging/backend.h
new file mode 100644
index 00000000..ae270efe
--- /dev/null
+++ b/src/common/logging/backend.h
@@ -0,0 +1,134 @@
+// Copyright 2014 Citra Emulator Project
+// Licensed under GPLv2+
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include <cstdarg>
+#include <memory>
+#include <vector>
+
+#include "common/concurrent_ring_buffer.h"
+
+#include "common/logging/log.h"
+
+namespace Log {
+
+/**
+ * A log entry. Log entries are store in a structured format to permit more varied output
+ * formatting on different frontends, as well as facilitating filtering and aggregation.
+ */
+struct Entry {
+    std::chrono::microseconds timestamp;
+    Class log_class;
+    Level log_level;
+    std::string location;
+    std::string message;
+
+    Entry() = default;
+
+    // TODO(yuriks) Use defaulted move constructors once MSVC supports them
+#define MOVE(member) member(std::move(o.member))
+    Entry(Entry&& o)
+        : MOVE(timestamp), MOVE(log_class), MOVE(log_level),
+        MOVE(location), MOVE(message)
+    {}
+#undef MOVE
+
+    Entry& operator=(const Entry&& o) {
+#define MOVE(member) member = std::move(o.member)
+        MOVE(timestamp);
+        MOVE(log_class);
+        MOVE(log_level);
+        MOVE(location);
+        MOVE(message);
+#undef MOVE
+        return *this;
+    }
+};
+
+struct ClassInfo {
+    Class log_class;
+
+    /**
+        * Total number of (direct or indirect) sub classes this class has. If any, they follow in
+        * sequence after this class in the class list.
+        */
+    unsigned int num_children = 0;
+
+    ClassInfo(Class log_class) : log_class(log_class) {}
+};
+
+/**
+ * Logging management class. This class has the dual purpose of acting as an exchange point between
+ * the logging clients and the log outputter, as well as containing reflection info about available
+ * log classes.
+ */
+class Logger {
+private:
+    using Buffer = Common::ConcurrentRingBuffer<Entry, 16 * 1024 / sizeof(Entry)>;
+
+public:
+    static const size_t QUEUE_CLOSED = Buffer::QUEUE_CLOSED;
+
+    Logger();
+
+    /**
+     * Returns a list of all vector classes and subclasses. The sequence returned is a pre-order of
+     * classes and subclasses, which together with the `num_children` field in ClassInfo, allows
+     * you to recover the hierarchy.
+     */
+    const std::vector<ClassInfo>& GetClasses() const { return all_classes; }
+
+    /**
+     * Returns the name of the passed log class as a C-string. Subclasses are separated by periods
+     * instead of underscores as in the enumeration.
+     */
+    static const char* GetLogClassName(Class log_class);
+
+    /**
+     * Returns the name of the passed log level as a C-string.
+     */
+    static const char* GetLevelName(Level log_level);
+
+    /**
+     * Appends a messages to the log buffer.
+     * @note This function is thread safe.
+     */
+    void LogMessage(Entry entry);
+
+    /**
+     * Retrieves a batch of messages from the log buffer, blocking until they are available.
+     * @note This function is thread safe.
+     *
+     * @param out_buffer Destination buffer that will receive the log entries.
+     * @param buffer_len The maximum size of `out_buffer`.
+     * @return The number of entries stored. In case the logger is shutting down, `QUEUE_CLOSED` is
+     *         returned, no entries are stored and the logger should shutdown.
+     */
+    size_t GetEntries(Entry* out_buffer, size_t buffer_len);
+
+    /**
+     * Initiates a shutdown of the logger. This will indicate to log output clients that they
+     * should shutdown.
+     */
+    void Close() { ring_buffer.Close(); }
+
+    /**
+     * Returns true if Close() has already been called on the Logger.
+     */
+    bool IsClosed() const { return ring_buffer.IsClosed(); }
+
+private:
+    Buffer ring_buffer;
+    std::vector<ClassInfo> all_classes;
+};
+
+/// 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);
+/// Initializes the default Logger.
+std::shared_ptr<Logger> InitGlobalLogger();
+
+}
diff --git a/src/common/logging/filter.cpp b/src/common/logging/filter.cpp
new file mode 100644
index 00000000..0cf9b05e
--- /dev/null
+++ b/src/common/logging/filter.cpp
@@ -0,0 +1,132 @@
+// Copyright 2014 Citra Emulator Project
+// Licensed under GPLv2+
+// Refer to the license.txt file included.
+
+#include <algorithm>
+
+#include "common/logging/filter.h"
+#include "common/logging/backend.h"
+#include "common/string_util.h"
+
+namespace Log {
+
+Filter::Filter(Level default_level) {
+    ResetAll(default_level);
+}
+
+void Filter::ResetAll(Level level) {
+    class_levels.fill(level);
+}
+
+void Filter::SetClassLevel(Class log_class, Level level) {
+    class_levels[static_cast<size_t>(log_class)] = level;
+}
+
+void Filter::SetSubclassesLevel(const ClassInfo& log_class, Level level) {
+    const size_t log_class_i = static_cast<size_t>(log_class.log_class);
+
+    const size_t begin = log_class_i + 1;
+    const size_t end = begin + log_class.num_children;
+    for (size_t i = begin; begin < end; ++i) {
+        class_levels[i] = level;
+    }
+}
+
+void Filter::ParseFilterString(const std::string& filter_str) {
+    auto clause_begin = filter_str.cbegin();
+    while (clause_begin != filter_str.cend()) {
+        auto clause_end = std::find(clause_begin, filter_str.cend(), ' ');
+
+        // If clause isn't empty
+        if (clause_end != clause_begin) {
+            ParseFilterRule(clause_begin, clause_end);
+        }
+
+        if (clause_end != filter_str.cend()) {
+            // Skip over the whitespace
+            ++clause_end;
+        }
+        clause_begin = clause_end;
+    }
+}
+
+template <typename It>
+static Level GetLevelByName(const It begin, const It end) {
+    for (u8 i = 0; i < static_cast<u8>(Level::Count); ++i) {
+        const char* level_name = Logger::GetLevelName(static_cast<Level>(i));
+        if (Common::ComparePartialString(begin, end, level_name)) {
+            return static_cast<Level>(i);
+        }
+    }
+    return Level::Count;
+}
+
+template <typename It>
+static Class GetClassByName(const It begin, const It end) {
+    for (ClassType i = 0; i < static_cast<ClassType>(Class::Count); ++i) {
+        const char* level_name = Logger::GetLogClassName(static_cast<Class>(i));
+        if (Common::ComparePartialString(begin, end, level_name)) {
+            return static_cast<Class>(i);
+        }
+    }
+    return Class::Count;
+}
+
+template <typename InputIt, typename T>
+static InputIt find_last(InputIt begin, const InputIt end, const T& value) {
+    auto match = end;
+    while (begin != end) {
+        auto new_match = std::find(begin, end, value);
+        if (new_match != end) {
+            match = new_match;
+            ++new_match;
+        }
+        begin = new_match;
+    }
+    return match;
+}
+
+bool Filter::ParseFilterRule(const std::string::const_iterator begin,
+        const std::string::const_iterator end) {
+    auto level_separator = std::find(begin, end, ':');
+    if (level_separator == end) {
+        LOG_ERROR(Log, "Invalid log filter. Must specify a log level after `:`: %s",
+                std::string(begin, end).c_str());
+        return false;
+    }
+
+    const Level level = GetLevelByName(level_separator + 1, end);
+    if (level == Level::Count) {
+        LOG_ERROR(Log, "Unknown log level in filter: %s", std::string(begin, end).c_str());
+        return false;
+    }
+
+    if (Common::ComparePartialString(begin, level_separator, "*")) {
+        ResetAll(level);
+        return true;
+    }
+
+    auto class_name_end = find_last(begin, level_separator, '.');
+    if (class_name_end != level_separator &&
+            !Common::ComparePartialString(class_name_end + 1, level_separator, "*")) {
+        class_name_end = level_separator;
+    }
+
+    const Class log_class = GetClassByName(begin, class_name_end);
+    if (log_class == Class::Count) {
+        LOG_ERROR(Log, "Unknown log class in filter: %s", std::string(begin, end).c_str());
+        return false;
+    }
+
+    if (class_name_end == level_separator) {
+        SetClassLevel(log_class, level);
+    }
+    SetSubclassesLevel(log_class, level);
+    return true;
+}
+
+bool Filter::CheckMessage(Class log_class, Level level) const {
+    return static_cast<u8>(level) >= static_cast<u8>(class_levels[static_cast<size_t>(log_class)]);
+}
+
+}
diff --git a/src/common/logging/filter.h b/src/common/logging/filter.h
new file mode 100644
index 00000000..32b14b15
--- /dev/null
+++ b/src/common/logging/filter.h
@@ -0,0 +1,63 @@
+// Copyright 2014 Citra Emulator Project
+// Licensed under GPLv2+
+// Refer to the license.txt file included.
+
+#include <array>
+#include <string>
+
+#include "common/logging/log.h"
+
+namespace Log {
+
+struct ClassInfo;
+
+/**
+ * Implements a log message filter which allows different log classes to have different minimum
+ * severity levels. The filter can be changed at runtime and can be parsed from a string to allow
+ * editing via the interface or loading from a configuration file.
+ */
+class Filter {
+public:
+    /// Initializes the filter with all classes having `default_level` as the minimum level.
+    Filter(Level default_level);
+
+    /// Resets the filter so that all classes have `level` as the minimum displayed level.
+    void ResetAll(Level level);
+    /// Sets the minimum level of `log_class` (and not of its subclasses) to `level`.
+    void SetClassLevel(Class log_class, Level level);
+    /**
+     * Sets the minimum level of all of `log_class` subclasses to `level`. The level of `log_class`
+     * itself is not changed.
+     */
+    void SetSubclassesLevel(const ClassInfo& log_class, Level level);
+
+    /**
+     * Parses a filter string and applies it to this filter.
+     *
+     * A filter string consists of a space-separated list of filter rules, each of the format
+     * `<class>:<level>`. `<class>` is a log class name, with subclasses separated using periods.
+     * A rule for a given class also affects all of its subclasses. `*` wildcards are allowed and
+     * can be used to apply a rule to all classes or to all subclasses of a class without affecting
+     * the parent class. `<level>` a severity level name which will be set as the minimum logging
+     * level of the matched classes. Rules are applied left to right, with each rule overriding
+     * previous ones in the sequence.
+     *
+     * A few examples of filter rules:
+     *  - `*:Info` -- Resets the level of all classes to Info.
+     *  - `Service:Info` -- Sets the level of Service and all subclasses (Service.FS, Service.APT,
+     *                       etc.) to Info.
+     *  - `Service.*:Debug` -- Sets the level of all Service subclasses to Debug, while leaving the
+     *                         level of Service unchanged.
+     *  - `Service.FS:Trace` -- Sets the level of the Service.FS class to Trace.
+     */
+    void ParseFilterString(const std::string& filter_str);
+    bool ParseFilterRule(const std::string::const_iterator start, const std::string::const_iterator end);
+
+    /// Matches class/level combination against the filter, returning true if it passed.
+    bool CheckMessage(Class log_class, Level level) const;
+
+private:
+    std::array<Level, (size_t)Class::Count> class_levels;
+};
+
+}
diff --git a/src/common/logging/log.h b/src/common/logging/log.h
new file mode 100644
index 00000000..1eec34fb
--- /dev/null
+++ b/src/common/logging/log.h
@@ -0,0 +1,115 @@
+// Copyright 2014 Citra Emulator Project
+// Licensed under GPLv2+
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include <cassert>
+#include <chrono>
+#include <string>
+
+#include "common/common_types.h"
+
+namespace Log {
+
+/// Specifies the severity or level of detail of the log message.
+enum class Level : u8 {
+    Trace,    ///< Extremely detailed and repetitive debugging information that is likely to
+              ///  pollute logs.
+    Debug,    ///< Less detailed debugging information.
+    Info,     ///< Status information from important points during execution.
+    Warning,  ///< Minor or potential problems found during execution of a task.
+    Error,    ///< Major problems found during execution of a task that prevent it from being
+              ///  completed.
+    Critical, ///< Major problems during execution that threathen the stability of the entire
+              ///  application.
+
+    Count ///< Total number of logging levels
+};
+
+typedef u8 ClassType;
+
+/**
+ * Specifies the sub-system that generated the log message.
+ *
+ * @note If you add a new entry here, also add a corresponding one to `ALL_LOG_CLASSES` in log.cpp.
+ */
+enum class Class : ClassType {
+    Log,                        ///< Messages about the log system itself
+    Common,                     ///< Library routines
+    Common_Filesystem,          ///< Filesystem interface library
+    Common_Memory,              ///< Memory mapping and management functions
+    Core,                       ///< LLE emulation core
+    Core_ARM11,                 ///< ARM11 CPU core
+    Config,                     ///< Emulator configuration (including commandline)
+    Debug,                      ///< Debugging tools
+    Debug_Emulated,             ///< Debug messages from the emulated programs
+    Debug_GPU,                  ///< GPU debugging tools
+    Debug_Breakpoint,           ///< Logging breakpoints and watchpoints
+    Kernel,                     ///< The HLE implementation of the CTR kernel
+    Kernel_SVC,                 ///< Kernel system calls
+    Service,                    ///< HLE implementation of system services. Each major service
+                                ///  should have its own subclass.
+    Service_SRV,                ///< The SRV (Service Directory) implementation
+    Service_FS,                 ///< The FS (Filesystem) service implementation
+    Service_APT,                ///< The APT (Applets) service
+    Service_GSP,                ///< The GSP (GPU control) service
+    Service_AC,                 ///< The AC (WiFi status) service
+    Service_PTM,                ///< The PTM (Power status & misc.) service
+    Service_CFG,                ///< The CFG (Configuration) service
+    Service_DSP,                ///< The DSP (DSP control) service
+    Service_HID,                ///< The HID (User input) service
+    HW,                         ///< Low-level hardware emulation
+    HW_Memory,                  ///< Memory-map and address translation
+    HW_GPU,                     ///< GPU control emulation
+    Frontend,                   ///< Emulator UI
+    Render,                     ///< Emulator video output and hardware acceleration
+    Render_Software,            ///< Software renderer backend
+    Render_OpenGL,              ///< OpenGL backend
+    Loader,                     ///< ROM loader
+
+    Count ///< Total number of logging classes
+};
+
+/**
+ * Level below which messages are simply discarded without buffering regardless of the display
+ * settings.
+ */
+const Level MINIMUM_LEVEL =
+#ifdef _DEBUG
+    Level::Trace;
+#else
+    Level::Debug;
+#endif
+
+/**
+ * Logs a message to the global logger. This proxy exists to avoid exposing the details of the
+ * Logger class, including the ConcurrentRingBuffer template, to all files that desire to log
+ * messages, reducing unecessary recompilations.
+ */
+void LogMessage(Class log_class, Level log_level,
+    const char* filename, unsigned int line_nr, const char* function,
+#ifdef _MSC_VER
+    _Printf_format_string_
+#endif
+    const char* format, ...)
+#ifdef __GNUC__
+    __attribute__((format(printf, 6, 7)))
+#endif
+    ;
+
+} // namespace Log
+
+#define LOG_GENERIC(log_class, log_level, ...) \
+    do { \
+        if (::Log::Level::log_level >= ::Log::MINIMUM_LEVEL) \
+            ::Log::LogMessage(::Log::Class::log_class, ::Log::Level::log_level, \
+                       __FILE__, __LINE__, __func__, __VA_ARGS__); \
+    } while (0)
+
+#define LOG_TRACE(   log_class, ...) LOG_GENERIC(log_class, Trace,    __VA_ARGS__)
+#define LOG_DEBUG(   log_class, ...) LOG_GENERIC(log_class, Debug,    __VA_ARGS__)
+#define LOG_INFO(    log_class, ...) LOG_GENERIC(log_class, Info,     __VA_ARGS__)
+#define LOG_WARNING( log_class, ...) LOG_GENERIC(log_class, Warning,  __VA_ARGS__)
+#define LOG_ERROR(   log_class, ...) LOG_GENERIC(log_class, Error,    __VA_ARGS__)
+#define LOG_CRITICAL(log_class, ...) LOG_GENERIC(log_class, Critical, __VA_ARGS__)
diff --git a/src/common/logging/text_formatter.cpp b/src/common/logging/text_formatter.cpp
new file mode 100644
index 00000000..3fe43534
--- /dev/null
+++ b/src/common/logging/text_formatter.cpp
@@ -0,0 +1,126 @@
+// Copyright 2014 Citra Emulator Project
+// Licensed under GPLv2+
+// Refer to the license.txt file included.
+
+#include <array>
+#include <cstdio>
+
+#ifdef _WIN32
+#   define WIN32_LEAN_AND_MEAN
+#   include <Windows.h>
+#endif
+
+#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"
+
+namespace Log {
+
+// TODO(bunnei): This should be moved to a generic path manipulation library
+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 = Logger::GetLogClassName(entry.log_class);
+    const char* level_name = Logger::GetLevelName(entry.log_level);
+
+    snprintf(out_text, text_len, "[%4u.%06u] %s <%s> %s: %s",
+        time_seconds, time_fractional, class_name, level_name,
+        TrimSourcePath(entry.location.c_str()), entry.message.c_str());
+}
+
+static void ChangeConsoleColor(Level level) {
+#ifdef _WIN32
+    static HANDLE console_handle = GetStdHandle(STD_ERROR_HANDLE);
+
+    WORD color = 0;
+    switch (level) {
+    case Level::Trace: // Grey
+        color = FOREGROUND_INTENSITY; break;
+    case Level::Debug: // Cyan
+        color = FOREGROUND_GREEN | FOREGROUND_BLUE; break;
+    case Level::Info: // Bright gray
+        color = FOREGROUND_RED | FOREGROUND_GREEN | FOREGROUND_BLUE; break;
+    case Level::Warning: // Bright yellow
+        color = FOREGROUND_RED | FOREGROUND_GREEN | FOREGROUND_INTENSITY; break;
+    case Level::Error: // Bright red
+        color = FOREGROUND_RED | FOREGROUND_INTENSITY; break;
+    case Level::Critical: // Bright magenta
+        color = FOREGROUND_RED | FOREGROUND_BLUE | FOREGROUND_INTENSITY; break;
+    }
+
+    SetConsoleTextAttribute(console_handle, color);
+#else
+#define ESC "\x1b"
+    const char* color = "";
+    switch (level) {
+    case Level::Trace: // Grey
+        color = ESC "[1;30m"; break;
+    case Level::Debug: // Cyan
+        color = ESC "[0;36m"; break;
+    case Level::Info: // Bright gray
+        color = ESC "[0;37m"; break;
+    case Level::Warning: // Bright yellow
+        color = ESC "[1;33m"; break;
+    case Level::Error: // Bright red
+        color = ESC "[1;31m"; break;
+    case Level::Critical: // Bright magenta
+        color = ESC "[1;35m"; break;
+    }
+#undef ESC
+
+    fputs(color, stderr);
+#endif
+}
+
+void PrintMessage(const Entry& entry) {
+    ChangeConsoleColor(entry.log_level);
+    std::array<char, 4 * 1024> format_buffer;
+    FormatLogMessage(entry, format_buffer.data(), format_buffer.size());
+    fputs(format_buffer.data(), stderr);
+    fputc('\n', stderr);
+}
+
+void TextLoggingLoop(std::shared_ptr<Logger> logger, const Filter* filter) {
+    std::array<Entry, 256> entry_buffer;
+
+    while (true) {
+        size_t num_entries = logger->GetEntries(entry_buffer.data(), entry_buffer.size());
+        if (num_entries == Logger::QUEUE_CLOSED) {
+            break;
+        }
+        for (size_t i = 0; i < num_entries; ++i) {
+            const Entry& entry = entry_buffer[i];
+            if (filter->CheckMessage(entry.log_class, entry.log_level)) {
+                PrintMessage(entry);
+            }
+        }
+    }
+}
+
+}
diff --git a/src/common/logging/text_formatter.h b/src/common/logging/text_formatter.h
new file mode 100644
index 00000000..d7e298e2
--- /dev/null
+++ b/src/common/logging/text_formatter.h
@@ -0,0 +1,39 @@
+// Copyright 2014 Citra Emulator Project
+// Licensed under GPLv2+
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include <cstddef>
+#include <memory>
+
+namespace Log {
+
+class Logger;
+struct Entry;
+class Filter;
+
+/**
+ * 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 occurence 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);
+/// Formats and prints a log entry to stderr.
+void PrintMessage(const Entry& entry);
+
+/**
+ * Logging loop that repeatedly reads messages from the provided logger and prints them to the
+ * console. It is the baseline barebones log outputter.
+ */
+void TextLoggingLoop(std::shared_ptr<Logger> logger, const Filter* filter);
+
+}