common/logging: Apply nodiscard where applicable

Applies the nodiscard attribute where it would be a bug/logic error to
ignore the return value.

Also marks inline member functions as noexcept where applicable.

src/common/alignment.h

@@ -8,25 +8,25 @@
 namespace Common {
 
 template <typename T>
-constexpr T AlignUp(T value, std::size_t size) {
+[[nodiscard]] constexpr T AlignUp(T value, std::size_t size) noexcept {
     static_assert(std::is_unsigned_v<T>, "T must be an unsigned value.");
     return static_cast<T>(value + (size - value % size) % size);
 }
 
 template <typename T>
-constexpr T AlignDown(T value, std::size_t size) {
+[[nodiscard]] constexpr T AlignDown(T value, std::size_t size) noexcept {
     static_assert(std::is_unsigned_v<T>, "T must be an unsigned value.");
     return static_cast<T>(value - value % size);
 }
 
 template <typename T>
-constexpr bool Is4KBAligned(T value) {
+[[nodiscard]] constexpr bool Is4KBAligned(T value) noexcept {
     static_assert(std::is_unsigned_v<T>, "T must be an unsigned value.");
     return (value & 0xFFF) == 0;
 }
 
 template <typename T>
-constexpr bool IsWordAligned(T value) {
+[[nodiscard]] constexpr bool IsWordAligned(T value) noexcept {
     static_assert(std::is_unsigned_v<T>, "T must be an unsigned value.");
     return (value & 0b11) == 0;
 }

src/common/bit_field.h

@@ -135,8 +135,8 @@ public:
      * containing several bitfields can be assembled by formatting each of their values and ORing
      * the results together.
      */
-    static constexpr FORCE_INLINE StorageType FormatValue(const T& value) {
+    [[nodiscard]] static constexpr FORCE_INLINE StorageType FormatValue(const T& value) noexcept {
-        return ((StorageType)value << position) & mask;
+        return (static_cast<StorageType>(value) << position) & mask;
     }
 
     /**
@@ -144,7 +144,8 @@ public:
      * (such as Value() or operator T), but this can be used to extract a value from a bitfield
      * union in a constexpr context.
      */
-    static constexpr FORCE_INLINE T ExtractValue(const StorageType& storage) {
+    [[nodiscard]] static constexpr FORCE_INLINE T
+    ExtractValue(const StorageType& storage) noexcept {
         if constexpr (std::numeric_limits<UnderlyingType>::is_signed) {
             std::size_t shift = 8 * sizeof(T) - bits;
             return static_cast<T>(static_cast<UnderlyingType>(storage << (shift - position)) >>
@@ -168,19 +169,19 @@ public:
     constexpr BitField(BitField&&) noexcept = default;
     constexpr BitField& operator=(BitField&&) noexcept = default;
 
-    constexpr FORCE_INLINE operator T() const {
+    [[nodiscard]] constexpr FORCE_INLINE operator T() const noexcept {
         return Value();
     }
 
-    constexpr FORCE_INLINE void Assign(const T& value) {
+    constexpr FORCE_INLINE void Assign(const T& value) noexcept {
         storage = (static_cast<StorageType>(storage) & ~mask) | FormatValue(value);
     }
 
-    constexpr T Value() const {
+    [[nodiscard]] constexpr T Value() const noexcept {
         return ExtractValue(storage);
     }
 
-    constexpr explicit operator bool() const {
+    [[nodiscard]] constexpr explicit operator bool() const noexcept {
         return Value() != 0;
     }
 

src/common/bit_util.h

@@ -17,12 +17,12 @@ namespace Common {
 
 /// Gets the size of a specified type T in bits.
 template <typename T>
-constexpr std::size_t BitSize() {
+[[nodiscard]] constexpr std::size_t BitSize() noexcept {
     return sizeof(T) * CHAR_BIT;
 }
 
 #ifdef _MSC_VER
-inline u32 CountLeadingZeroes32(u32 value) {
+[[nodiscard]] inline u32 CountLeadingZeroes32(u32 value) noexcept {
     unsigned long leading_zero = 0;
 
     if (_BitScanReverse(&leading_zero, value) != 0) {
@@ -32,7 +32,7 @@ inline u32 CountLeadingZeroes32(u32 value) {
     return 32;
 }
 
-inline u32 CountLeadingZeroes64(u64 value) {
+[[nodiscard]] inline u32 CountLeadingZeroes64(u64 value) noexcept {
     unsigned long leading_zero = 0;
 
     if (_BitScanReverse64(&leading_zero, value) != 0) {
@@ -42,7 +42,7 @@ inline u32 CountLeadingZeroes64(u64 value) {
     return 64;
 }
 #else
-inline u32 CountLeadingZeroes32(u32 value) {
+[[nodiscard]] inline u32 CountLeadingZeroes32(u32 value) noexcept {
     if (value == 0) {
         return 32;
     }
@@ -50,7 +50,7 @@ inline u32 CountLeadingZeroes32(u32 value) {
     return static_cast<u32>(__builtin_clz(value));
 }
 
-inline u32 CountLeadingZeroes64(u64 value) {
+[[nodiscard]] inline u32 CountLeadingZeroes64(u64 value) noexcept {
     if (value == 0) {
         return 64;
     }
@@ -60,7 +60,7 @@ inline u32 CountLeadingZeroes64(u64 value) {
 #endif
 
 #ifdef _MSC_VER
-inline u32 CountTrailingZeroes32(u32 value) {
+[[nodiscard]] inline u32 CountTrailingZeroes32(u32 value) noexcept {
     unsigned long trailing_zero = 0;
 
     if (_BitScanForward(&trailing_zero, value) != 0) {
@@ -70,7 +70,7 @@ inline u32 CountTrailingZeroes32(u32 value) {
     return 32;
 }
 
-inline u32 CountTrailingZeroes64(u64 value) {
+[[nodiscard]] inline u32 CountTrailingZeroes64(u64 value) noexcept {
     unsigned long trailing_zero = 0;
 
     if (_BitScanForward64(&trailing_zero, value) != 0) {
@@ -80,7 +80,7 @@ inline u32 CountTrailingZeroes64(u64 value) {
     return 64;
 }
 #else
-inline u32 CountTrailingZeroes32(u32 value) {
+[[nodiscard]] inline u32 CountTrailingZeroes32(u32 value) noexcept {
     if (value == 0) {
         return 32;
     }
@@ -88,7 +88,7 @@ inline u32 CountTrailingZeroes32(u32 value) {
     return static_cast<u32>(__builtin_ctz(value));
 }
 
-inline u32 CountTrailingZeroes64(u64 value) {
+[[nodiscard]] inline u32 CountTrailingZeroes64(u64 value) noexcept {
     if (value == 0) {
         return 64;
     }

src/common/common_funcs.h

@@ -52,11 +52,11 @@ __declspec(dllimport) void __stdcall DebugBreak(void);
 // Call directly after the command or use the error num.
 // This function might change the error code.
 // Defined in Misc.cpp.
-std::string GetLastErrorMsg();
+[[nodiscard]] std::string GetLastErrorMsg();
 
 namespace Common {
 
-constexpr u32 MakeMagic(char a, char b, char c, char d) {
+[[nodiscard]] constexpr u32 MakeMagic(char a, char b, char c, char d) noexcept {
     return a | b << 8 | c << 16 | d << 24;
 }
 

src/common/file_util.h

@@ -46,19 +46,19 @@ struct FSTEntry {
 };
 
 // Returns true if file filename exists
-bool Exists(const std::string& filename);
+[[nodiscard]] bool Exists(const std::string& filename);
 
 // Returns true if filename is a directory
-bool IsDirectory(const std::string& filename);
+[[nodiscard]] bool IsDirectory(const std::string& filename);
 
 // Returns the size of filename (64bit)
-u64 GetSize(const std::string& filename);
+[[nodiscard]] u64 GetSize(const std::string& filename);
 
 // Overloaded GetSize, accepts file descriptor
-u64 GetSize(const int fd);
+[[nodiscard]] u64 GetSize(int fd);
 
 // Overloaded GetSize, accepts FILE*
-u64 GetSize(FILE* f);
+[[nodiscard]] u64 GetSize(FILE* f);
 
 // Returns true if successful, or path already exists.
 bool CreateDir(const std::string& filename);
@@ -118,7 +118,7 @@ u64 ScanDirectoryTree(const std::string& directory, FSTEntry& parent_entry,
 bool DeleteDirRecursively(const std::string& directory, unsigned int recursion = 256);
 
 // Returns the current directory
-std::string GetCurrentDir();
+[[nodiscard]] std::string GetCurrentDir();
 
 // Create directory and copy contents (does not overwrite existing files)
 void CopyDir(const std::string& source_path, const std::string& dest_path);
@@ -128,22 +128,22 @@ bool SetCurrentDir(const std::string& directory);
 
 // Returns a pointer to a string with a yuzu data dir in the user's home
 // directory. To be used in "multi-user" mode (that is, installed).
-const std::string& GetUserPath(UserPath path, const std::string& new_path = "");
+[[nodiscard]] const std::string& GetUserPath(UserPath path, const std::string& new_path = "");
 
-std::string GetHactoolConfigurationPath();
+[[nodiscard]] std::string GetHactoolConfigurationPath();
 
-std::string GetNANDRegistrationDir(bool system = false);
+[[nodiscard]] std::string GetNANDRegistrationDir(bool system = false);
 
 // Returns the path to where the sys file are
-std::string GetSysDirectory();
+[[nodiscard]] std::string GetSysDirectory();
 
 #ifdef __APPLE__
-std::string GetBundleDirectory();
+[[nodiscard]] std::string GetBundleDirectory();
 #endif
 
 #ifdef _WIN32
-const std::string& GetExeDirectory();
+[[nodiscard]] const std::string& GetExeDirectory();
-std::string AppDataRoamingDirectory();
+[[nodiscard]] std::string AppDataRoamingDirectory();
 #endif
 
 std::size_t WriteStringToFile(bool text_file, const std::string& str, const char* filename);
@@ -162,26 +162,27 @@ void SplitFilename83(const std::string& filename, std::array<char, 9>& short_nam
 
 // Splits the path on '/' or '\' and put the components into a vector
 // i.e. "C:\Users\Yuzu\Documents\save.bin" becomes {"C:", "Users", "Yuzu", "Documents", "save.bin" }
-std::vector<std::string> SplitPathComponents(std::string_view filename);
+[[nodiscard]] std::vector<std::string> SplitPathComponents(std::string_view filename);
 
 // Gets all of the text up to the last '/' or '\' in the path.
-std::string_view GetParentPath(std::string_view path);
+[[nodiscard]] std::string_view GetParentPath(std::string_view path);
 
 // Gets all of the text after the first '/' or '\' in the path.
-std::string_view GetPathWithoutTop(std::string_view path);
+[[nodiscard]] std::string_view GetPathWithoutTop(std::string_view path);
 
 // Gets the filename of the path
-std::string_view GetFilename(std::string_view path);
+[[nodiscard]] std::string_view GetFilename(std::string_view path);
 
 // Gets the extension of the filename
-std::string_view GetExtensionFromFilename(std::string_view name);
+[[nodiscard]] std::string_view GetExtensionFromFilename(std::string_view name);
 
 // Removes the final '/' or '\' if one exists
-std::string_view RemoveTrailingSlash(std::string_view path);
+[[nodiscard]] std::string_view RemoveTrailingSlash(std::string_view path);
 
 // Creates a new vector containing indices [first, last) from the original.
 template <typename T>
-std::vector<T> SliceVector(const std::vector<T>& vector, std::size_t first, std::size_t last) {
+[[nodiscard]] std::vector<T> SliceVector(const std::vector<T>& vector, std::size_t first,
+                                         std::size_t last) {
     if (first >= last)
         return {};
     last = std::min<std::size_t>(last, vector.size());
@@ -192,7 +193,8 @@ enum class DirectorySeparator { ForwardSlash, BackwardSlash, PlatformDefault };
 
 // Removes trailing slash, makes all '\\' into '/', and removes duplicate '/'. Makes '/' into '\\'
 // depending if directory_separator is BackwardSlash or PlatformDefault and running on windows
-std::string SanitizePath(std::string_view path,
+[[nodiscard]] std::string SanitizePath(
+    std::string_view path,
     DirectorySeparator directory_separator = DirectorySeparator::ForwardSlash);
 
 // simple wrapper for cstdlib file functions to
@@ -261,13 +263,13 @@ public:
         return WriteArray(str.c_str(), str.length());
     }
 
-    bool IsOpen() const {
+    [[nodiscard]] bool IsOpen() const {
         return nullptr != m_file;
     }
 
     bool Seek(s64 off, int origin) const;
-    u64 Tell() const;
+    [[nodiscard]] u64 Tell() const;
-    u64 GetSize() const;
+    [[nodiscard]] u64 GetSize() const;
     bool Resize(u64 size);
     bool Flush();
 

src/common/hex_util.h

@@ -13,12 +13,12 @@
 
 namespace Common {
 
-u8 ToHexNibble(char c1);
+[[nodiscard]] u8 ToHexNibble(char c1);
 
-std::vector<u8> HexStringToVector(std::string_view str, bool little_endian);
+[[nodiscard]] std::vector<u8> HexStringToVector(std::string_view str, bool little_endian);
 
 template <std::size_t Size, bool le = false>
-std::array<u8, Size> HexStringToArray(std::string_view str) {
+[[nodiscard]] std::array<u8, Size> HexStringToArray(std::string_view str) {
     std::array<u8, Size> out{};
     if constexpr (le) {
         for (std::size_t i = 2 * Size - 2; i <= 2 * Size; i -= 2)
@@ -30,17 +30,17 @@ std::array<u8, Size> HexStringToArray(std::string_view str) {
     return out;
 }
 
-std::string HexVectorToString(const std::vector<u8>& vector, bool upper = true);
+[[nodiscard]] std::string HexVectorToString(const std::vector<u8>& vector, bool upper = true);
 
 template <std::size_t Size>
-std::string HexArrayToString(std::array<u8, Size> array, bool upper = true) {
+[[nodiscard]] std::string HexArrayToString(std::array<u8, Size> array, bool upper = true) {
     std::string out;
     for (u8 c : array)
         out += fmt::format(upper ? "{:02X}" : "{:02x}", c);
     return out;
 }
 
-std::array<u8, 0x10> operator"" _array16(const char* str, std::size_t len);
+[[nodiscard]] std::array<u8, 0x10> operator"" _array16(const char* str, std::size_t len);
-std::array<u8, 0x20> operator"" _array32(const char* str, std::size_t len);
+[[nodiscard]] std::array<u8, 0x20> operator"" _array32(const char* str, std::size_t len);
 
 } // namespace Common

src/common/logging/backend.h

@@ -46,7 +46,7 @@ public:
     virtual void SetFilter(const Filter& new_filter) {
         filter = new_filter;
     }
-    virtual const char* GetName() const = 0;
+    [[nodiscard]] virtual const char* GetName() const = 0;
     virtual void Write(const Entry& entry) = 0;
 
 private:
@@ -58,12 +58,14 @@ private:
  */
 class ConsoleBackend : public Backend {
 public:
-    static const char* Name() {
+    [[nodiscard]] static const char* Name() {
         return "console";
     }
-    const char* GetName() const override {
+
+    [[nodiscard]] const char* GetName() const override {
         return Name();
     }
+
     void Write(const Entry& entry) override;
 };
 
@@ -72,13 +74,14 @@ public:
  */
 class ColorConsoleBackend : public Backend {
 public:
-    static const char* Name() {
+    [[nodiscard]] static const char* Name() {
         return "color_console";
     }
 
-    const char* GetName() const override {
+    [[nodiscard]] const char* GetName() const override {
         return Name();
     }
+
     void Write(const Entry& entry) override;
 };
 
@@ -89,11 +92,11 @@ class FileBackend : public Backend {
 public:
     explicit FileBackend(const std::string& filename);
 
-    static const char* Name() {
+    [[nodiscard]] static const char* Name() {
         return "file";
     }
 
-    const char* GetName() const override {
+    [[nodiscard]] const char* GetName() const override {
         return Name();
     }
 
@@ -109,12 +112,14 @@ private:
  */
 class DebuggerBackend : public Backend {
 public:
-    static const char* Name() {
+    [[nodiscard]] static const char* Name() {
         return "debugger";
     }
-    const char* GetName() const override {
+
+    [[nodiscard]] const char* GetName() const override {
         return Name();
     }
+
     void Write(const Entry& entry) override;
 };
 
@@ -122,18 +127,18 @@ void AddBackend(std::unique_ptr<Backend> backend);
 
 void RemoveBackend(std::string_view backend_name);
 
-Backend* GetBackend(std::string_view backend_name);
+[[nodiscard]] Backend* GetBackend(std::string_view 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.
  */
-const char* GetLogClassName(Class log_class);
+[[nodiscard]] const char* GetLogClassName(Class log_class);
 
 /**
  * Returns the name of the passed log level as a C-string.
  */
-const char* GetLevelName(Level log_level);
+[[nodiscard]] const char* GetLevelName(Level log_level);
 
 /**
  * The global filter will prevent any messages from even being processed if they are filtered. Each

src/common/logging/filter.h

@@ -43,10 +43,10 @@ public:
     void ParseFilterString(std::string_view filter_view);
 
     /// Matches class/level combination against the filter, returning true if it passed.
-    bool CheckMessage(Class log_class, Level level) const;
+    [[nodiscard]] bool CheckMessage(Class log_class, Level level) const;
 
     /// Returns true if any logging classes are set to debug
-    bool IsDebug() const;
+    [[nodiscard]] bool IsDebug() const;
 
 private:
     std::array<Level, static_cast<std::size_t>(Class::Count)> class_levels;

src/common/logging/text_formatter.h

@@ -12,7 +12,7 @@ namespace Log {
 struct Entry;
 
 /// Formats a log entry into the provided text buffer.
-std::string FormatLogMessage(const Entry& entry);
+[[nodiscard]] 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 according to the severity level.

src/common/lz4_compression.h

@@ -16,7 +16,7 @@ namespace Common::Compression {
  *
  * @return the compressed data.
  */
-std::vector<u8> CompressDataLZ4(const u8* source, std::size_t source_size);
+[[nodiscard]] std::vector<u8> CompressDataLZ4(const u8* source, std::size_t source_size);
 
 /**
  * Utilizes the LZ4 subalgorithm LZ4HC with the specified compression level. Higher compression
@@ -30,7 +30,8 @@ std::vector<u8> CompressDataLZ4(const u8* source, std::size_t source_size);
  *
  * @return the compressed data.
  */
-std::vector<u8> CompressDataLZ4HC(const u8* source, std::size_t source_size, s32 compression_level);
+[[nodiscard]] std::vector<u8> CompressDataLZ4HC(const u8* source, std::size_t source_size,
+                                                s32 compression_level);
 
 /**
  * Utilizes the LZ4 subalgorithm LZ4HC with the highest possible compression level.
@@ -40,7 +41,7 @@ std::vector<u8> CompressDataLZ4HC(const u8* source, std::size_t source_size, s32
  *
  * @return the compressed data.
  */
-std::vector<u8> CompressDataLZ4HCMax(const u8* source, std::size_t source_size);
+[[nodiscard]] std::vector<u8> CompressDataLZ4HCMax(const u8* source, std::size_t source_size);
 
 /**
  * Decompresses a source memory region with LZ4 and returns the uncompressed data in a vector.
@@ -50,6 +51,7 @@ std::vector<u8> CompressDataLZ4HCMax(const u8* source, std::size_t source_size);
  *
  * @return the decompressed data.
  */
-std::vector<u8> DecompressDataLZ4(const std::vector<u8>& compressed, std::size_t uncompressed_size);
+[[nodiscard]] std::vector<u8> DecompressDataLZ4(const std::vector<u8>& compressed,
+                                                std::size_t uncompressed_size);
 
 } // namespace Common::Compression

src/common/math_util.h

@@ -18,24 +18,24 @@ struct Rectangle {
     T right{};
     T bottom{};
 
-    constexpr Rectangle() = default;
+    constexpr Rectangle() noexcept = default;
 
-    constexpr Rectangle(T left, T top, T right, T bottom)
+    constexpr Rectangle(T left, T top, T right, T bottom) noexcept
         : left(left), top(top), right(right), bottom(bottom) {}
 
-    T GetWidth() const {
+    [[nodiscard]] T GetWidth() const noexcept {
         return std::abs(static_cast<std::make_signed_t<T>>(right - left));
     }
-    T GetHeight() const {
+    [[nodiscard]] T GetHeight() const noexcept {
         return std::abs(static_cast<std::make_signed_t<T>>(bottom - top));
     }
-    Rectangle<T> TranslateX(const T x) const {
+    [[nodiscard]] Rectangle<T> TranslateX(const T x) const noexcept {
         return Rectangle{left + x, top, right + x, bottom};
     }
-    Rectangle<T> TranslateY(const T y) const {
+    [[nodiscard]] Rectangle<T> TranslateY(const T y) const noexcept {
         return Rectangle{left, top + y, right, bottom + y};
     }
-    Rectangle<T> Scale(const float s) const {
+    [[nodiscard]] Rectangle<T> Scale(const float s) const noexcept {
         return Rectangle{left, top, static_cast<T>(left + GetWidth() * s),
                          static_cast<T>(top + GetHeight() * s)};
     }

src/common/memory_hook.h

@@ -26,21 +26,22 @@ class MemoryHook {
 public:
     virtual ~MemoryHook();
 
-    virtual std::optional<bool> IsValidAddress(VAddr addr) = 0;
+    [[nodiscard]] virtual std::optional<bool> IsValidAddress(VAddr addr) = 0;
 
-    virtual std::optional<u8> Read8(VAddr addr) = 0;
+    [[nodiscard]] virtual std::optional<u8> Read8(VAddr addr) = 0;
-    virtual std::optional<u16> Read16(VAddr addr) = 0;
+    [[nodiscard]] virtual std::optional<u16> Read16(VAddr addr) = 0;
-    virtual std::optional<u32> Read32(VAddr addr) = 0;
+    [[nodiscard]] virtual std::optional<u32> Read32(VAddr addr) = 0;
-    virtual std::optional<u64> Read64(VAddr addr) = 0;
+    [[nodiscard]] virtual std::optional<u64> Read64(VAddr addr) = 0;
 
-    virtual bool ReadBlock(VAddr src_addr, void* dest_buffer, std::size_t size) = 0;
+    [[nodiscard]] virtual bool ReadBlock(VAddr src_addr, void* dest_buffer, std::size_t size) = 0;
 
-    virtual bool Write8(VAddr addr, u8 data) = 0;
+    [[nodiscard]] virtual bool Write8(VAddr addr, u8 data) = 0;
-    virtual bool Write16(VAddr addr, u16 data) = 0;
+    [[nodiscard]] virtual bool Write16(VAddr addr, u16 data) = 0;
-    virtual bool Write32(VAddr addr, u32 data) = 0;
+    [[nodiscard]] virtual bool Write32(VAddr addr, u32 data) = 0;
-    virtual bool Write64(VAddr addr, u64 data) = 0;
+    [[nodiscard]] virtual bool Write64(VAddr addr, u64 data) = 0;
 
-    virtual bool WriteBlock(VAddr dest_addr, const void* src_buffer, std::size_t size) = 0;
+    [[nodiscard]] virtual bool WriteBlock(VAddr dest_addr, const void* src_buffer,
+                                          std::size_t size) = 0;
 };
 
 using MemoryHookPointer = std::shared_ptr<MemoryHook>;

src/common/multi_level_queue.h

@@ -43,21 +43,21 @@ public:
         using reference = std::conditional_t<is_constant, const T&, T&>;
         using difference_type = typename std::pointer_traits<pointer>::difference_type;
 
-        friend bool operator==(const iterator_impl& lhs, const iterator_impl& rhs) {
+        [[nodiscard]] friend bool operator==(const iterator_impl& lhs, const iterator_impl& rhs) {
             if (lhs.IsEnd() && rhs.IsEnd())
                 return true;
             return std::tie(lhs.current_priority, lhs.it) == std::tie(rhs.current_priority, rhs.it);
         }
 
-        friend bool operator!=(const iterator_impl& lhs, const iterator_impl& rhs) {
+        [[nodiscard]] friend bool operator!=(const iterator_impl& lhs, const iterator_impl& rhs) {
             return !operator==(lhs, rhs);
         }
 
-        reference operator*() const {
+        [[nodiscard]] reference operator*() const {
             return *it;
         }
 
-        pointer operator->() const {
+        [[nodiscard]] pointer operator->() const {
             return it.operator->();
         }
 
@@ -143,15 +143,15 @@ public:
         explicit iterator_impl(container_ref mlq, u32 current_priority)
             : mlq(mlq), it(), current_priority(current_priority) {}
 
-        bool IsEnd() const {
+        [[nodiscard]] bool IsEnd() const {
             return current_priority == mlq.depth();
         }
 
-        list_iterator GetBeginItForPrio() const {
+        [[nodiscard]] list_iterator GetBeginItForPrio() const {
             return mlq.levels[current_priority].begin();
         }
 
-        list_iterator GetEndItForPrio() const {
+        [[nodiscard]] list_iterator GetEndItForPrio() const {
             return mlq.levels[current_priority].end();
         }
 
@@ -223,15 +223,15 @@ public:
         ListShiftForward(levels[priority], n);
     }
 
-    std::size_t depth() const {
+    [[nodiscard]] std::size_t depth() const {
         return Depth;
     }
 
-    std::size_t size(u32 priority) const {
+    [[nodiscard]] std::size_t size(u32 priority) const {
         return levels[priority].size();
     }
 
-    std::size_t size() const {
+    [[nodiscard]] std::size_t size() const {
         u64 priorities = used_priorities;
         std::size_t size = 0;
         while (priorities != 0) {
@@ -242,64 +242,64 @@ public:
         return size;
     }
 
-    bool empty() const {
+    [[nodiscard]] bool empty() const {
         return used_priorities == 0;
     }
 
-    bool empty(u32 priority) const {
+    [[nodiscard]] bool empty(u32 priority) const {
         return (used_priorities & (1ULL << priority)) == 0;
     }
 
-    u32 highest_priority_set(u32 max_priority = 0) const {
+    [[nodiscard]] u32 highest_priority_set(u32 max_priority = 0) const {
         const u64 priorities =
             max_priority == 0 ? used_priorities : (used_priorities & ~((1ULL << max_priority) - 1));
         return priorities == 0 ? Depth : static_cast<u32>(CountTrailingZeroes64(priorities));
     }
 
-    u32 lowest_priority_set(u32 min_priority = Depth - 1) const {
+    [[nodiscard]] u32 lowest_priority_set(u32 min_priority = Depth - 1) const {
         const u64 priorities = min_priority >= Depth - 1
                                    ? used_priorities
                                    : (used_priorities & ((1ULL << (min_priority + 1)) - 1));
         return priorities == 0 ? Depth : 63 - CountLeadingZeroes64(priorities);
     }
 
-    const_iterator cbegin(u32 max_prio = 0) const {
+    [[nodiscard]] const_iterator cbegin(u32 max_prio = 0) const {
         const u32 priority = highest_priority_set(max_prio);
         return priority == Depth ? cend()
                                  : const_iterator{*this, levels[priority].cbegin(), priority};
     }
-    const_iterator begin(u32 max_prio = 0) const {
+    [[nodiscard]] const_iterator begin(u32 max_prio = 0) const {
         return cbegin(max_prio);
     }
-    iterator begin(u32 max_prio = 0) {
+    [[nodiscard]] iterator begin(u32 max_prio = 0) {
         const u32 priority = highest_priority_set(max_prio);
         return priority == Depth ? end() : iterator{*this, levels[priority].begin(), priority};
     }
 
-    const_iterator cend(u32 min_prio = Depth - 1) const {
+    [[nodiscard]] const_iterator cend(u32 min_prio = Depth - 1) const {
         return min_prio == Depth - 1 ? const_iterator{*this, Depth} : cbegin(min_prio + 1);
     }
-    const_iterator end(u32 min_prio = Depth - 1) const {
+    [[nodiscard]] const_iterator end(u32 min_prio = Depth - 1) const {
         return cend(min_prio);
     }
-    iterator end(u32 min_prio = Depth - 1) {
+    [[nodiscard]] iterator end(u32 min_prio = Depth - 1) {
         return min_prio == Depth - 1 ? iterator{*this, Depth} : begin(min_prio + 1);
     }
 
-    T& front(u32 max_priority = 0) {
+    [[nodiscard]] T& front(u32 max_priority = 0) {
         const u32 priority = highest_priority_set(max_priority);
         return levels[priority == Depth ? 0 : priority].front();
     }
-    const T& front(u32 max_priority = 0) const {
+    [[nodiscard]] const T& front(u32 max_priority = 0) const {
         const u32 priority = highest_priority_set(max_priority);
         return levels[priority == Depth ? 0 : priority].front();
     }
 
-    T back(u32 min_priority = Depth - 1) {
+    [[nodiscard]] T back(u32 min_priority = Depth - 1) {
         const u32 priority = lowest_priority_set(min_priority); // intended
         return levels[priority == Depth ? 63 : priority].back();
     }
-    const T& back(u32 min_priority = Depth - 1) const {
+    [[nodiscard]] const T& back(u32 min_priority = Depth - 1) const {
         const u32 priority = lowest_priority_set(min_priority); // intended
         return levels[priority == Depth ? 63 : priority].back();
     }
@@ -322,7 +322,8 @@ private:
         in_list.splice(position, out_list, element);
     }
 
-    static const_list_iterator ListIterateTo(const std::list<T>& list, const T& element) {
+    [[nodiscard]] static const_list_iterator ListIterateTo(const std::list<T>& list,
+                                                           const T& element) {
         auto it = list.cbegin();
         while (it != list.cend() && *it != element) {
             ++it;

src/common/page_table.h

@@ -33,11 +33,11 @@ struct SpecialRegion {
 
     MemoryHookPointer handler;
 
-    bool operator<(const SpecialRegion& other) const {
+    [[nodiscard]] bool operator<(const SpecialRegion& other) const {
         return std::tie(type, handler) < std::tie(other.type, other.handler);
     }
 
-    bool operator==(const SpecialRegion& other) const {
+    [[nodiscard]] bool operator==(const SpecialRegion& other) const {
         return std::tie(type, handler) == std::tie(other.type, other.handler);
     }
 };

src/common/param_package.h

@@ -24,14 +24,14 @@ public:
     ParamPackage& operator=(const ParamPackage& other) = default;
     ParamPackage& operator=(ParamPackage&& other) = default;
 
-    std::string Serialize() const;
+    [[nodiscard]] std::string Serialize() const;
-    std::string Get(const std::string& key, const std::string& default_value) const;
+    [[nodiscard]] std::string Get(const std::string& key, const std::string& default_value) const;
-    int Get(const std::string& key, int default_value) const;
+    [[nodiscard]] int Get(const std::string& key, int default_value) const;
-    float Get(const std::string& key, float default_value) const;
+    [[nodiscard]] float Get(const std::string& key, float default_value) const;
     void Set(const std::string& key, std::string value);
     void Set(const std::string& key, int value);
     void Set(const std::string& key, float value);
-    bool Has(const std::string& key) const;
+    [[nodiscard]] bool Has(const std::string& key) const;
     void Erase(const std::string& key);
     void Clear();
 

src/common/quaternion.h

@@ -14,35 +14,39 @@ public:
     Vec3<T> xyz;
     T w{};
 
-    Quaternion<decltype(-T{})> Inverse() const {
+    [[nodiscard]] Quaternion<decltype(-T{})> Inverse() const noexcept {
         return {-xyz, w};
     }
 
-    Quaternion<decltype(T{} + T{})> operator+(const Quaternion& other) const {
+    [[nodiscard]] Quaternion<decltype(T{} + T{})> operator+(const Quaternion& other) const
+        noexcept {
         return {xyz + other.xyz, w + other.w};
     }
 
-    Quaternion<decltype(T{} - T{})> operator-(const Quaternion& other) const {
+    [[nodiscard]] Quaternion<decltype(T{} - T{})> operator-(const Quaternion& other) const
+        noexcept {
         return {xyz - other.xyz, w - other.w};
     }
 
-    Quaternion<decltype(T{} * T{} - T{} * T{})> operator*(const Quaternion& other) const {
+    [[nodiscard]] Quaternion<decltype(T{} * T{} - T{} * T{})> operator*(
+        const Quaternion& other) const noexcept {
         return {xyz * other.w + other.xyz * w + Cross(xyz, other.xyz),
                 w * other.w - Dot(xyz, other.xyz)};
     }
 
-    Quaternion<T> Normalized() const {
+    [[nodiscard]] Quaternion<T> Normalized() const noexcept {
         T length = std::sqrt(xyz.Length2() + w * w);
         return {xyz / length, w / length};
     }
 };
 
 template <typename T>
-auto QuaternionRotate(const Quaternion<T>& q, const Vec3<T>& v) {
+[[nodiscard]] auto QuaternionRotate(const Quaternion<T>& q, const Vec3<T>& v) noexcept {
     return v + 2 * Cross(q.xyz, Cross(q.xyz, v) + v * q.w);
 }
 
-inline Quaternion<float> MakeQuaternion(const Vec3<float>& axis, float angle) {
+[[nodiscard]] inline Quaternion<float> MakeQuaternion(const Vec3<float>& axis,
+                                                      float angle) noexcept {
     return {axis * std::sin(angle / 2), std::cos(angle / 2)};
 }
 

src/common/ring_buffer.h

@@ -64,7 +64,7 @@ public:
     /// @param output     Where to store the popped slots
     /// @param max_slots  Maximum number of slots to pop
     /// @returns The number of slots actually popped
-    std::size_t Pop(void* output, std::size_t max_slots = ~std::size_t(0)) {
+    [[nodiscard]] std::size_t Pop(void* output, std::size_t max_slots = ~std::size_t(0)) {
         const std::size_t read_index = m_read_index.load();
         const std::size_t slots_filled = m_write_index.load() - read_index;
         const std::size_t pop_count = std::min(slots_filled, max_slots);
@@ -83,7 +83,7 @@ public:
         return pop_count;
     }
 
-    std::vector<T> Pop(std::size_t max_slots = ~std::size_t(0)) {
+    [[nodiscard]] std::vector<T> Pop(std::size_t max_slots = ~std::size_t(0)) {
         std::vector<T> out(std::min(max_slots, capacity) * granularity);
         const std::size_t count = Pop(out.data(), out.size() / granularity);
         out.resize(count * granularity);
@@ -91,12 +91,12 @@ public:
     }
 
     /// @returns Number of slots used
-    std::size_t Size() const {
+    [[nodiscard]] std::size_t Size() const {
         return m_write_index.load() - m_read_index.load();
     }
 
     /// @returns Maximum size of ring buffer
-    constexpr std::size_t Capacity() const {
+    [[nodiscard]] constexpr std::size_t Capacity() const {
         return capacity;
     }
 

src/common/string_util.h

@@ -12,19 +12,19 @@
 namespace Common {
 
 /// Make a string lowercase
-std::string ToLower(std::string str);
+[[nodiscard]] std::string ToLower(std::string str);
 
 /// Make a string uppercase
-std::string ToUpper(std::string str);
+[[nodiscard]] std::string ToUpper(std::string str);
 
-std::string StringFromBuffer(const std::vector<u8>& data);
+[[nodiscard]] std::string StringFromBuffer(const std::vector<u8>& data);
 
-std::string StripSpaces(const std::string& s);
+[[nodiscard]] std::string StripSpaces(const std::string& s);
-std::string StripQuotes(const std::string& s);
+[[nodiscard]] std::string StripQuotes(const std::string& s);
 
-std::string StringFromBool(bool value);
+[[nodiscard]] std::string StringFromBool(bool value);
 
-std::string TabsToSpaces(int tab_size, std::string in);
+[[nodiscard]] std::string TabsToSpaces(int tab_size, std::string in);
 
 void SplitString(const std::string& str, char delim, std::vector<std::string>& output);
 
@@ -34,15 +34,15 @@ bool SplitPath(const std::string& full_path, std::string* _pPath, std::string* _
 
 void BuildCompleteFilename(std::string& _CompleteFilename, const std::string& _Path,
                            const std::string& _Filename);
-std::string ReplaceAll(std::string result, const std::string& src, const std::string& dest);
+[[nodiscard]] std::string ReplaceAll(std::string result, const std::string& src,
+                                     const std::string& dest);
 
-std::string UTF16ToUTF8(const std::u16string& input);
+[[nodiscard]] std::string UTF16ToUTF8(const std::u16string& input);
-std::u16string UTF8ToUTF16(const std::string& input);
+[[nodiscard]] std::u16string UTF8ToUTF16(const std::string& input);
 
 #ifdef _WIN32
-std::string UTF16ToUTF8(const std::wstring& input);
+[[nodiscard]] std::string UTF16ToUTF8(const std::wstring& input);
-std::wstring UTF8ToUTF16W(const std::string& str);
+[[nodiscard]] std::wstring UTF8ToUTF16W(const std::string& str);
-
 #endif
 
 /**
@@ -50,7 +50,7 @@ std::wstring UTF8ToUTF16W(const std::string& str);
  * `other` for equality.
  */
 template <typename InIt>
-bool ComparePartialString(InIt begin, InIt end, const char* other) {
+[[nodiscard]] bool ComparePartialString(InIt begin, InIt end, const char* other) {
     for (; begin != end && *other != '\0'; ++begin, ++other) {
         if (*begin != *other) {
             return false;
@@ -64,14 +64,15 @@ bool ComparePartialString(InIt begin, InIt end, const char* other) {
  * Creates a std::string from a fixed-size NUL-terminated char buffer. If the buffer isn't
  * NUL-terminated then the string ends at max_len characters.
  */
-std::string StringFromFixedZeroTerminatedBuffer(const char* buffer, std::size_t max_len);
+[[nodiscard]] std::string StringFromFixedZeroTerminatedBuffer(const char* buffer,
+                                                              std::size_t max_len);
 
 /**
  * Creates a UTF-16 std::u16string from a fixed-size NUL-terminated char buffer. If the buffer isn't
  * null-terminated, then the string ends at the greatest multiple of two less then or equal to
  * max_len_bytes.
  */
-std::u16string UTF16StringFromFixedZeroTerminatedBuffer(std::u16string_view buffer,
+[[nodiscard]] std::u16string UTF16StringFromFixedZeroTerminatedBuffer(std::u16string_view buffer,
                                                                       std::size_t max_len);
 
 /**
@@ -84,6 +85,6 @@ std::u16string UTF16StringFromFixedZeroTerminatedBuffer(std::u16string_view buff
  *             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");
+[[nodiscard]] const char* TrimSourcePath(const char* path, const char* root = "src");
 
 } // namespace Common

src/common/telemetry.h

@@ -42,7 +42,7 @@ public:
      * Gets the name of this field.
      * @returns Name of this field as a string.
      */
-    virtual const std::string& GetName() const = 0;
+    [[nodiscard]] virtual const std::string& GetName() const = 0;
 };
 
 /**
@@ -63,29 +63,29 @@ public:
 
     void Accept(VisitorInterface& visitor) const override;
 
-    const std::string& GetName() const override {
+    [[nodiscard]] const std::string& GetName() const override {
         return name;
     }
 
     /**
      * Returns the type of the field.
      */
-    FieldType GetType() const {
+    [[nodiscard]] FieldType GetType() const {
         return type;
     }
 
     /**
      * Returns the value of the field.
      */
-    const T& GetValue() const {
+    [[nodiscard]] const T& GetValue() const {
         return value;
     }
 
-    bool operator==(const Field& other) const {
+    [[nodiscard]] bool operator==(const Field& other) const {
         return (type == other.type) && (name == other.name) && (value == other.value);
     }
 
-    bool operator!=(const Field& other) const {
+    [[nodiscard]] bool operator!=(const Field& other) const {
         return !(*this == other);
     }
 

src/common/thread.h

@@ -29,7 +29,7 @@ public:
     }
 
     template <class Clock, class Duration>
-    bool WaitUntil(const std::chrono::time_point<Clock, Duration>& time) {
+    [[nodiscard]] bool WaitUntil(const std::chrono::time_point<Clock, Duration>& time) {
         std::unique_lock lk{mutex};
         if (!condvar.wait_until(lk, time, [this] { return is_set; }))
             return false;

src/common/thread_queue_list.h

@@ -25,7 +25,7 @@ struct ThreadQueueList {
     }
 
     // Only for debugging, returns priority level.
-    Priority contains(const T& uid) const {
+    [[nodiscard]] Priority contains(const T& uid) const {
         for (Priority i = 0; i < NUM_QUEUES; ++i) {
             const Queue& cur = queues[i];
             if (std::find(cur.data.cbegin(), cur.data.cend(), uid) != cur.data.cend()) {
@@ -36,7 +36,7 @@ struct ThreadQueueList {
         return -1;
     }
 
-    T get_first() const {
+    [[nodiscard]] T get_first() const {
         const Queue* cur = first;
         while (cur != nullptr) {
             if (!cur->data.empty()) {
@@ -49,7 +49,7 @@ struct ThreadQueueList {
     }
 
     template <typename UnaryPredicate>
-    T get_first_filter(UnaryPredicate filter) const {
+    [[nodiscard]] T get_first_filter(UnaryPredicate filter) const {
         const Queue* cur = first;
         while (cur != nullptr) {
             if (!cur->data.empty()) {
@@ -129,7 +129,7 @@ struct ThreadQueueList {
         first = nullptr;
     }
 
-    bool empty(Priority priority) const {
+    [[nodiscard]] bool empty(Priority priority) const {
         const Queue* cur = &queues[priority];
         return cur->data.empty();
     }

src/common/threadsafe_queue.h

@@ -25,15 +25,15 @@ public:
         delete read_ptr;
     }
 
-    std::size_t Size() const {
+    [[nodiscard]] std::size_t Size() const {
         return size.load();
     }
 
-    bool Empty() const {
+    [[nodiscard]] bool Empty() const {
         return Size() == 0;
     }
 
-    T& Front() const {
+    [[nodiscard]] T& Front() const {
         return read_ptr->current;
     }
 
@@ -123,15 +123,15 @@ private:
 template <typename T>
 class MPSCQueue {
 public:
-    std::size_t Size() const {
+    [[nodiscard]] std::size_t Size() const {
         return spsc_queue.Size();
     }
 
-    bool Empty() const {
+    [[nodiscard]] bool Empty() const {
         return spsc_queue.Empty();
     }
 
-    T& Front() const {
+    [[nodiscard]] T& Front() const {
         return spsc_queue.Front();
     }
 

src/common/timer.h

@@ -19,18 +19,18 @@ public:
 
     // The time difference is always returned in milliseconds, regardless of alternative internal
     // representation
-    std::chrono::milliseconds GetTimeDifference();
+    [[nodiscard]] std::chrono::milliseconds GetTimeDifference();
     void AddTimeDifference();
 
-    static std::chrono::seconds GetTimeSinceJan1970();
+    [[nodiscard]] static std::chrono::seconds GetTimeSinceJan1970();
-    static std::chrono::seconds GetLocalTimeSinceJan1970();
+    [[nodiscard]] static std::chrono::seconds GetLocalTimeSinceJan1970();
-    static double GetDoubleTime();
+    [[nodiscard]] static double GetDoubleTime();
 
-    static std::string GetTimeFormatted();
+    [[nodiscard]] static std::string GetTimeFormatted();
-    std::string GetTimeElapsedFormatted() const;
+    [[nodiscard]] std::string GetTimeElapsedFormatted() const;
-    std::chrono::milliseconds GetTimeElapsed();
+    [[nodiscard]] std::chrono::milliseconds GetTimeElapsed();
 
-    static std::chrono::milliseconds GetTimeMs();
+    [[nodiscard]] static std::chrono::milliseconds GetTimeMs();
 
 private:
     std::chrono::milliseconds m_LastTime;

src/common/uint128.cpp

@@ -12,7 +12,7 @@
 
 namespace Common {
 
-u128 Multiply64Into128(u64 a, u64 b) {
+u128 Multiply64Into128(u64 a, u64 b) noexcept {
     u128 result;
 #ifdef _MSC_VER
     result[0] = _umul128(a, b, &result[1]);
@@ -24,7 +24,7 @@ u128 Multiply64Into128(u64 a, u64 b) {
     return result;
 }
 
-std::pair<u64, u64> Divide128On32(u128 dividend, u32 divisor) {
+std::pair<u64, u64> Divide128On32(u128 dividend, u32 divisor) noexcept {
     u64 remainder = dividend[0] % divisor;
     u64 accum = dividend[0] / divisor;
     if (dividend[1] == 0)

src/common/uint128.h

@@ -10,10 +10,10 @@
 namespace Common {
 
 // This function multiplies 2 u64 values and produces a u128 value;
-u128 Multiply64Into128(u64 a, u64 b);
+[[nodiscard]] u128 Multiply64Into128(u64 a, u64 b) noexcept;
 
 // This function divides a u128 by a u32 value and produces two u64 values:
 // the result of division and the remainder
-std::pair<u64, u64> Divide128On32(u128 dividend, u32 divisor);
+[[nodiscard]] std::pair<u64, u64> Divide128On32(u128 dividend, u32 divisor) noexcept;
 
 } // namespace Common

src/common/zstd_compression.h

@@ -17,7 +17,8 @@ namespace Common::Compression {
  *
  * @return the compressed data.
  */
-std::vector<u8> CompressDataZSTD(const u8* source, std::size_t source_size, s32 compression_level);
+[[nodiscard]] std::vector<u8> CompressDataZSTD(const u8* source, std::size_t source_size,
+                                               s32 compression_level);
 
 /**
  * Compresses a source memory region with Zstandard with the default compression level and returns
@@ -28,7 +29,7 @@ std::vector<u8> CompressDataZSTD(const u8* source, std::size_t source_size, s32
  *
  * @return the compressed data.
  */
-std::vector<u8> CompressDataZSTDDefault(const u8* source, std::size_t source_size);
+[[nodiscard]] std::vector<u8> CompressDataZSTDDefault(const u8* source, std::size_t source_size);
 
 /**
  * Decompresses a source memory region with Zstandard and returns the uncompressed data in a vector.
@@ -37,6 +38,6 @@ std::vector<u8> CompressDataZSTDDefault(const u8* source, std::size_t source_siz
  *
  * @return the decompressed data.
  */
-std::vector<u8> DecompressDataZSTD(const std::vector<u8>& compressed);
+[[nodiscard]] std::vector<u8> DecompressDataZSTD(const std::vector<u8>& compressed);
 
 } // namespace Common::Compression