[common/logging] eliminate uneeded std::string{} allocations per each logging

Signed-off-by: lizzie <lizzie@eden-emu.dev>

src/common/logging.cpp

@@ -10,6 +10,7 @@
 #include <cstdlib>
 #include <regex>
 #include <thread>
+#include <fmt/base.h>
 
 #if defined(__ANDROID__)
 #include <android/log.h>
@@ -39,6 +40,19 @@
 
 namespace Common::Log {
 
+/// @brief 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 {
+    char const* message = nullptr;
+    size_t message_len = 0;
+    std::chrono::microseconds timestamp;
+    Class log_class{};
+    Level log_level{};
+    const char* filename = nullptr;
+    const char* function = nullptr;
+    uint32_t line_num = 0;
+};
+
 namespace {
 
 /// @brief Returns the name of the passed log class as a C-string. Subclasses are separated by periods
@@ -70,8 +84,6 @@ const char* GetLevelName(Level log_level) {
     }
 }
 
-}
-
 // Some IDEs prefer <file>:<line> instead, so let's just do that :)
 std::string FormatLogMessage(const Entry& entry) noexcept {
     if (!entry.filename) return "";
@@ -79,10 +91,9 @@ std::string FormatLogMessage(const Entry& entry) noexcept {
     auto const time_fractional = uint32_t(entry.timestamp.count() % 1000000);
     auto const class_name = GetLogClassName(entry.log_class);
     auto const level_name = GetLevelName(entry.log_level);
-    return fmt::format("[{:4d}.{:06d}] {} <{}> {}:{}:{}: {}", time_seconds, time_fractional, class_name, level_name, entry.filename, entry.line_num, entry.function, entry.message);
+    return fmt::format("[{:4d}.{:06d}] {} <{}> {}:{}:{}: {}\n", time_seconds, time_fractional, class_name, level_name, entry.filename, entry.line_num, entry.function, entry.message);
 }
 
-namespace {
 template <typename It>
 Level GetLevelByName(const It begin, const It end) {
     for (u32 i = 0; i < u32(Level::Count); ++i) {
@@ -127,25 +138,6 @@ bool ParseFilterRule(Filter& instance, Iterator begin, Iterator end) {
     instance.SetClassLevel(log_class, level);
     return true;
 }
-} // Anonymous namespace
-
-void Filter::ParseFilterString(std::string_view filter_view) {
-    auto clause_begin = filter_view.cbegin();
-    while (clause_begin != filter_view.cend()) {
-        auto clause_end = std::find(clause_begin, filter_view.cend(), ' ');
-        // If clause isn't empty
-        if (clause_end != clause_begin) {
-            ParseFilterRule(*this, clause_begin, clause_end);
-        }
-        if (clause_end != filter_view.cend()) {
-            // Skip over the whitespace
-            ++clause_end;
-        }
-        clause_begin = clause_end;
-    }
-}
-
-namespace {
 
 /// @brief Trims up to and including the last of ../, ..\, src/, src\ in a string
 /// do not be fooled this isn't generating new strings on .rodata :)
@@ -220,22 +212,24 @@ struct ColorConsoleBackend final : public Backend {
     ~ColorConsoleBackend() noexcept override {}
     void Write(const Entry& entry) noexcept override {
         if (enabled) {
-#define ESC "\x1b"
             auto const color_str = [&entry]() -> const char* {
                 switch (entry.log_level) {
-#define CCB_MAKE_COLOR_FMT(X) ESC X CCB_PRINTF_FMT ESC "[0m\n"
-                case Level::Debug: return CCB_MAKE_COLOR_FMT("[0;36m"); // Cyan
-                case Level::Info: return CCB_MAKE_COLOR_FMT("[0;37m"); // Bright gray
-                case Level::Warning: return CCB_MAKE_COLOR_FMT("[1;33m"); // Bright yellow
-                case Level::Error: return CCB_MAKE_COLOR_FMT("[1;31m"); // Bright red
-                case Level::Critical: return CCB_MAKE_COLOR_FMT("[1;35m"); // Bright magenta
-                default: return CCB_MAKE_COLOR_FMT("[1;30m"); // Grey
-#undef CCB_MAKE_COLOR_FMT
+                case Level::Debug: return "[0;36m"; // Cyan
+                case Level::Info: return "[0;37m"; // Bright gray
+                case Level::Warning: return "[1;33m"; // Bright yellow
+                case Level::Error: return "[1;31m"; // Bright red
+                case Level::Critical: return "[1;35m"; // Bright magenta
+                default: return "[1;30m"; // Grey
                 }
             }();
             auto const df = GetDirectFormatArgs(entry);
-            std::fprintf(stdout, color_str, df.time_seconds, df.time_fractional, df.class_name, df.level_name, entry.filename, entry.line_num, entry.function, entry.message.c_str());
-#undef ESC
+            // more restrictive, because take for example this simple prelude:
+            // [  50.872256] Config <Info> common/settings.cpp:142:LogSettings:
+            char buffer[100];
+            auto result = fmt::format_to_n(buffer, sizeof(buffer) - 1, "\x1b{}[{:4d}.{:06d}] {} <{}> {}:{}:{}: ", color_str, df.time_seconds, df.time_fractional, df.class_name, df.level_name, entry.filename, entry.line_num, entry.function, entry.message);
+            std::fwrite(buffer, 1, result.size, stdout);
+            std::fwrite(entry.message, 1, entry.message_len, stdout);
+            std::fwrite("\x1b[0m\n", 1, sizeof("\x1b[0m\n"), stdout);
         }
     }
     void Flush() noexcept override {}
@@ -246,7 +240,7 @@ struct ColorConsoleBackend final : public Backend {
 #ifndef __OPENORBIS__
 /// @brief Backend that writes to a file passed into the constructor
 struct FileBackend final : public Backend {
-    explicit FileBackend(const std::filesystem::path& filename) noexcept {
+    explicit FileBackend(const std::filesystem::path filename) noexcept {
         auto old_filename = filename;
         old_filename += ".old.txt";
         // Existence checks are done within the functions themselves.
@@ -261,7 +255,7 @@ struct FileBackend final : public Backend {
         if (!enabled)
             return;
 
-        auto message = FormatLogMessage(entry).append(1, '\n');
+        auto message = FormatLogMessage(entry);
 #ifndef __ANDROID__
         if (Settings::values.censor_username.GetValue()) {
             // This must be a static otherwise it would get checked on EVERY
@@ -269,8 +263,7 @@ struct FileBackend final : public Backend {
             static std::string username = []() -> std::string {
                 // in order of precedence
                 // LOGNAME usually works on UNIX, USERNAME on Windows
-                // Some UNIX systems suck and don't use LOGNAME so we also
-                // need USER :(
+                // Some UNIX systems suck and don't use LOGNAME so we also need USER :(
                 for (auto const var : { "LOGNAME", "USERNAME", "USER", })
                     if (auto const s = ::getenv(var); s != nullptr)
                         return std::string{s};
@@ -280,7 +273,7 @@ struct FileBackend final : public Backend {
                 boost::replace_all(message, username, "user");
         }
 #endif
-        bytes_written += file->WriteString(message);
+        bytes_written += file->WriteSpan(std::span<const char>{message.begin(), message.end()});
 
         // Option to log each line rather than 4k buffers
         if (Settings::values.log_flush_line.GetValue())
@@ -308,14 +301,13 @@ private:
     bool enabled = true;
 };
 #endif
-
 #ifdef _WIN32
 /// @brief Backend that writes to Visual Studio's output window
 struct DebuggerBackend final : public Backend {
     explicit DebuggerBackend() noexcept = default;
     ~DebuggerBackend() noexcept override = default;
     void Write(const Entry& entry) noexcept override {
-        ::OutputDebugStringW(UTF8ToUTF16W(FormatLogMessage(entry).append(1, '\n')).c_str());
+        ::OutputDebugStringW(UTF8ToUTF16W(FormatLogMessage(entry)).c_str());
     }
     void Flush() noexcept override {}
 };
@@ -377,7 +369,23 @@ struct Impl {
 #endif
     std::chrono::steady_clock::time_point time_origin{std::chrono::steady_clock::now()};
 };
-} // namespace
+} // Anonymous namespace
+
+void Filter::ParseFilterString(std::string_view filter_view) {
+    auto clause_begin = filter_view.cbegin();
+    while (clause_begin < filter_view.cend()) {
+        auto clause_end = std::find(clause_begin, filter_view.cend(), ' ');
+        // If clause isn't empty
+        if (clause_end != clause_begin) {
+            ParseFilterRule(*this, clause_begin, clause_end);
+        }
+        if (clause_end != filter_view.cend()) {
+            // Skip over the whitespace
+            ++clause_end;
+        }
+        clause_begin = clause_end;
+    }
+}
 
 // Constructor shall NOT depend upon Settings() or whatever
 // it's ran at global static ctor() time... so BE CAREFUL MFER!
@@ -418,10 +426,14 @@ void SetColorConsoleBackendEnabled(bool enabled) {
 
 void FmtLogMessageImpl(Class log_class, Level log_level, const char* filename, unsigned int line_num, const char* function, fmt::string_view format, const fmt::format_args& args) {
     if (logging_instance && logging_instance->filter.CheckMessage(log_class, log_level)) {
+        char buffer[BUFSIZ];
+        auto result = fmt::vformat_to_n(buffer, sizeof(buffer) - 1, format, args);
+        buffer[result.size] = '\0';
         auto const flush = ::Settings::values.log_flush_line.GetValue();
         logging_instance->ForEachBackend([=](Backend& backend) {
             backend.Write(Entry{
-                .message = fmt::vformat(format, args),
+                .message = buffer,
+                .message_len = result.size,
                 .timestamp = std::chrono::duration_cast<std::chrono::microseconds>(std::chrono::steady_clock::now() - logging_instance->time_origin),
                 .log_class = log_class,
                 .log_level = log_level,

src/common/logging.h

@@ -140,25 +140,4 @@ void Stop();
 void SetGlobalFilter(const Filter& filter);
 void SetColorConsoleBackendEnabled(bool enabled);
 
-/// @brief 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::string message;
-    std::chrono::microseconds timestamp;
-    Class log_class{};
-    Level log_level{};
-    const char* filename = nullptr;
-    const char* function = nullptr;
-    unsigned int line_num = 0;
-};
-
-/// Formats a log entry into the provided text buffer.
-std::string FormatLogMessage(const Entry& entry) noexcept;
-
-/// Prints the same message as `PrintMessage`, but colored according to the severity level.
-void PrintColoredMessage(const Entry& entry) noexcept;
-
-/// Formats and prints a log entry to the android logcat.
-void PrintMessageToLogcat(const Entry& entry) noexcept;
-
 } // namespace Common::Log

src/core/file_sys/ips_layer.cpp

@@ -3,12 +3,10 @@
 
 #include <algorithm>
 #include <cstring>
+#include <map>
 #include <sstream>
 #include <string>
 #include <utility>
-#include <span>
-#include <cctype>
-#include <ankerl/unordered_dense.h>
 
 #include "common/hex_util.h"
 #include "common/logging.h"
@@ -24,30 +22,61 @@ enum class IPSFileType {
     Error,
 };
 
-static IPSFileType IdentifyMagic(std::span<const u8> magic) {
-    if (magic.size() >= 5) {
-        if (std::memcmp(magic.data(), "PATCH", 5) == 0)
-            return IPSFileType::IPS;
-        if (std::memcmp(magic.data(), "IPS32", 5) == 0)
-            return IPSFileType::IPS32;
+constexpr std::array<std::pair<const char*, const char*>, 11> ESCAPE_CHARACTER_MAP{{
+    {"\\a", "\a"},
+    {"\\b", "\b"},
+    {"\\f", "\f"},
+    {"\\n", "\n"},
+    {"\\r", "\r"},
+    {"\\t", "\t"},
+    {"\\v", "\v"},
+    {"\\\\", "\\"},
+    {"\\\'", "\'"},
+    {"\\\"", "\""},
+    {"\\\?", "\?"},
+}};
+
+static IPSFileType IdentifyMagic(const std::vector<u8>& magic) {
+    if (magic.size() != 5) {
+        return IPSFileType::Error;
     }
+
+    static constexpr std::array<u8, 5> patch_magic{{'P', 'A', 'T', 'C', 'H'}};
+    if (std::equal(magic.begin(), magic.end(), patch_magic.begin())) {
+        return IPSFileType::IPS;
+    }
+
+    static constexpr std::array<u8, 5> ips32_magic{{'I', 'P', 'S', '3', '2'}};
+    if (std::equal(magic.begin(), magic.end(), ips32_magic.begin())) {
+        return IPSFileType::IPS32;
+    }
+
     return IPSFileType::Error;
 }
 
-static bool IsEOF(IPSFileType type, std::span<const u8> magic) {
-    return (type == IPSFileType::IPS && magic.size() > 3 && std::memcmp(magic.data(), "EOF", 3) == 0)
-        || (type == IPSFileType::IPS32 && magic.size() > 4 && std::memcmp(magic.data(), "EEOF", 4) == 0);
+static bool IsEOF(IPSFileType type, const std::vector<u8>& data) {
+    static constexpr std::array<u8, 3> eof{{'E', 'O', 'F'}};
+    if (type == IPSFileType::IPS && std::equal(data.begin(), data.end(), eof.begin())) {
+        return true;
+    }
+
+    static constexpr std::array<u8, 4> eeof{{'E', 'E', 'O', 'F'}};
+    return type == IPSFileType::IPS32 && std::equal(data.begin(), data.end(), eeof.begin());
 }
 
 VirtualFile PatchIPS(const VirtualFile& in, const VirtualFile& ips) {
     if (in == nullptr || ips == nullptr)
         return nullptr;
 
-    auto in_data = in->ReadAllBytes();
-    auto const type = IdentifyMagic(in_data);
+    const auto type = IdentifyMagic(ips->ReadBytes(0x5));
     if (type == IPSFileType::Error)
         return nullptr;
 
+    auto in_data = in->ReadAllBytes();
+    if (in_data.size() == 0) {
+        return nullptr;
+    }
+
     std::vector<u8> temp(type == IPSFileType::IPS ? 3 : 4);
     u64 offset = 5; // After header
     while (ips->Read(temp.data(), temp.size(), offset) == temp.size()) {
@@ -56,9 +85,12 @@ VirtualFile PatchIPS(const VirtualFile& in, const VirtualFile& ips) {
             break;
         }
 
-        u32 real_offset = (type == IPSFileType::IPS32)
-            ? ((temp[0] << 24) | (temp[1] << 16) | (temp[2] << 8) | temp[3])
-            : ((temp[0] << 16) | (temp[1] << 8) | temp[2]);
+        u32 real_offset{};
+        if (type == IPSFileType::IPS32)
+            real_offset = (temp[0] << 24) | (temp[1] << 16) | (temp[2] << 8) | temp[3];
+        else
+            real_offset = (temp[0] << 16) | (temp[1] << 8) | temp[2];
+
         if (real_offset > in_data.size()) {
             return nullptr;
         }
@@ -81,35 +113,34 @@ VirtualFile PatchIPS(const VirtualFile& in, const VirtualFile& ips) {
                 return nullptr;
 
             if (real_offset + rle_size > in_data.size())
-                rle_size = u16(in_data.size() - real_offset);
+                rle_size = static_cast<u16>(in_data.size() - real_offset);
             std::memset(in_data.data() + real_offset, *data, rle_size);
         } else { // Standard Patch
             auto read = data_size;
             if (real_offset + read > in_data.size())
-                read = u16(in_data.size() - real_offset);
+                read = static_cast<u16>(in_data.size() - real_offset);
             if (ips->Read(in_data.data() + real_offset, read, offset) != data_size)
                 return nullptr;
             offset += data_size;
         }
     }
-    if (IsEOF(type, temp)) {
-        return std::make_shared<VectorVfsFile>(std::move(in_data), in->GetName(), in->GetContainingDirectory());
+
+    if (!IsEOF(type, temp)) {
+        return nullptr;
     }
-    return nullptr;
+
+    return std::make_shared<VectorVfsFile>(std::move(in_data), in->GetName(),
+                                           in->GetContainingDirectory());
 }
 
-
-struct IPSwitchRecord {
-    std::array<uint8_t, 256 - sizeof(size_t)> data;
-    size_t count;
-};
 struct IPSwitchCompiler::IPSwitchPatch {
-    ankerl::unordered_dense::map<u32, IPSwitchRecord> records;
+    std::string name;
     bool enabled;
+    std::map<u32, std::vector<u8>> records;
 };
 
 IPSwitchCompiler::IPSwitchCompiler(VirtualFile patch_text_) : patch_text(std::move(patch_text_)) {
-    Parse(patch_text->ReadAllBytes());
+    Parse();
 }
 
 IPSwitchCompiler::~IPSwitchCompiler() = default;
@@ -118,159 +149,201 @@ std::array<u8, 32> IPSwitchCompiler::GetBuildID() const {
     return nso_build_id;
 }
 
-static IPSwitchRecord EscapeStringSequences(std::string_view sv) {
-    IPSwitchRecord r{};
-    for (auto it = sv.cbegin(); it != sv.cend(); ) {
-        if (*it == '\\' && it + 1 < sv.cend()) {
-            switch (it[1]) {
-            case 'n': r.data[r.count] = '\n'; break;
-            case 't': r.data[r.count] = '\t'; break;
-            case 'b': r.data[r.count] = '\b'; break;
-            case 'r': r.data[r.count] = '\r'; break;
-            case 'e': r.data[r.count] = '\e'; break;
-            case 'v': r.data[r.count] = '\v'; break;
-            case '?': r.data[r.count] = '\?'; break;
-            default: r.data[r.count] = it[1]; break;
-            }
-            ++r.count;
-            it += 2;
-        } else {
-            ++r.count;
-            ++it;
+bool IPSwitchCompiler::IsValid() const {
+    return valid;
+}
+
+static bool StartsWith(std::string_view base, std::string_view check) {
+    return base.size() >= check.size() && base.substr(0, check.size()) == check;
+}
+
+static std::string EscapeStringSequences(std::string in) {
+    for (const auto& seq : ESCAPE_CHARACTER_MAP) {
+        for (auto index = in.find(seq.first); index != std::string::npos;
+             index = in.find(seq.first, index)) {
+            in.replace(index, std::strlen(seq.first), seq.second);
+            index += std::strlen(seq.second);
         }
     }
-    return r;
+
+    return in;
 }
 
-[[nodiscard]] static inline std::array<u8, 32> ReadNSOBuildId(std::string_view const s) {
-    std::array<u8, 32> r{};
-    for (std::size_t i = 0; i < s.size(); ++i)
-        r[i / 2] |= u8(u8(Common::ToHexNibble(s[i])) << u8((i % 2) * 4));
-    return r;
+void IPSwitchCompiler::ParseFlag(const std::string& line) {
+    if (StartsWith(line, "@flag offset_shift ")) {
+        // Offset Shift Flag
+        offset_shift = std::strtoll(line.substr(19).c_str(), nullptr, 0);
+    } else if (StartsWith(line, "@little-endian")) {
+        // Set values to read as little endian
+        is_little_endian = true;
+    } else if (StartsWith(line, "@big-endian")) {
+        // Set values to read as big endian
+        is_little_endian = false;
+    } else if (StartsWith(line, "@flag print_values")) {
+        // Force printing of applied values
+        print_values = true;
+    }
 }
 
-void IPSwitchCompiler::Parse(std::span<u8 const> bytes) {
-    LOG_INFO(Loader, "IPSwitchCompiler: '{}'", patch_text->GetName());
-    bool is_little_endian = false;
-    s64 offset_shift = 0;
-    //bool print_values = false;
+void IPSwitchCompiler::Parse() {
+    const auto bytes = patch_text->ReadAllBytes();
+    std::stringstream s;
+    s.write(reinterpret_cast<const char*>(bytes.data()), bytes.size());
 
-    auto const parse_line = [&](std::string_view const line) {
-        // Keep in mind lines have trimmed spaces (at the end & start)!
-        LOG_INFO(Loader, "<{}>", line);
-        if (line.starts_with("@stop")) {
-            return false; // Force stop
-        } else if (line.starts_with("@nsobid-")) { // NSO Build ID Specifier
-            nso_build_id = ReadNSOBuildId(line.substr(8));
-        } else if (line.starts_with("@enabled")) {
-            patches.push_back({{}, true}); //enabled patch
-        } else if (line.starts_with("@disabled")) {
-            patches.push_back({{}, false}); //disabled patch
-        } else if (line.starts_with("@flag offset_shift ")) {
-            offset_shift = std::strtoll(line.data() + 19, nullptr, 0);  // Offset Shift Flag
-        } else if (line.starts_with("@little-endian")) {
-            is_little_endian = true;  // Set values to read as little endian
-        } else if (line.starts_with("@big-endian")) {
-            is_little_endian = false;  // Set values to read as big endian
-        } else if (line.starts_with("@flag print_values")) {
-            //print_values = true; // Force printing of applied values
-        } else if (line.starts_with("@")) {
-            LOG_WARNING(Loader, "Unknown flag {}", line);
-        } else {
-            size_t offset = size_t(std::strtoul(line.data(), nullptr, 16));
-            offset += size_t(offset_shift);
-            if (auto const first_quote = line.find_first_of("\"\'"); first_quote != std::string::npos) {
-                // string replacement
-                char quote = line[first_quote];
-                auto const start = line.cbegin() + first_quote + 1;
-                auto end = start;
-                for (; end < line.cend() && *end != quote; )
-                    end += (*end == '\\') ? 2 : 1;
-                if (start <= line.cend() && end <= line.cend()) {
-                    LOG_INFO(Loader, "[S] value @ {:#08X} ", offset);
-                    patches.back().records.insert_or_assign(u32(offset), EscapeStringSequences({start, end}));
-                } else {
-                    LOG_WARNING(Loader, "invalid string");
-                }
-            } else if (auto const first_space = line.find_last_of(" /\t\r\n"); first_space != std::string::npos) {
-                IPSwitchRecord r{}; // hex replacement
-                auto const start = line.cbegin() + first_space + 1;
-                auto const end = line.cend();
-                if (start <= line.cend() && end <= line.cend()) {
-                    auto const hs = Common::HexStringToVector({start, end}, is_little_endian);
-                    std::memcpy(r.data.data(), hs.data(), hs.size());
-                    r.count = hs.size();
-                    LOG_INFO(Loader, "[H] value @ {:#08X}", offset);
-                    patches.back().records.insert_or_assign(u32(offset), std::move(r));
-                } else {
-                    LOG_WARNING(Loader, "invalid line");
-                }
-            } else {
-                LOG_WARNING(Loader, "unhandled line!");
-            }
-        }
-        return true; //continue
-    };
+    std::vector<std::string> lines;
+    std::string stream_line;
+    while (std::getline(s, stream_line)) {
+        // Remove a trailing \r
+        if (!stream_line.empty() && stream_line.back() == '\r')
+            stream_line.pop_back();
+        lines.push_back(std::move(stream_line));
+    }
 
-    for (auto it = bytes.begin(); it < bytes.end(); ) {
-        auto const start = it;
-        auto end = start;
-        for (; end < bytes.end() && *end != '\n' && *end != '\r'; ++end)
-            ;
-        it = end + 1; //prepare for next line
-        std::string_view const sline{
-            reinterpret_cast<const char*>(bytes.data() + std::distance(bytes.begin(), start)),
-            size_t(std::distance(start, end))
-        };
-        if (sline.size() > 0) {
-            auto p = sline.cbegin();
-            // skip space off line
-            for (; p < sline.cend() && std::isspace(*p); ++p)
-                ;
-            // now make a nominal preprocessed line: remove comments
-            char quote = '\0';
-            auto const sline_start = p;
-            for (; p < sline.cend(); ) {
-                if ((!quote && p + 1 < sline.cend() && p[0] == '/' && p[1] == '/')
-                || (!quote && p[0] == '#')) {
-                    break;
-                } else if (p[0] == '\"' || p[0] == '\'') {
-                    quote = (p[0] == quote) ? '\0' : p[0];
-                    ++p;
-                } else if (p + 1 < sline.cend() && p[0] == '\\') {
-                    p += 2;
-                } else {
-                    ++p;
-                }
-            }
-            // now we have the preprocessed string ;)
-            std::string_view pp_str(sline_start, p);
-            if (pp_str.size() > 0 && !parse_line(pp_str)) {
+    for (std::size_t i = 0; i < lines.size(); ++i) {
+        auto line = lines[i];
+
+        // Remove midline comments
+        std::size_t comment_index = std::string::npos;
+        bool within_string = false;
+        for (std::size_t k = 0; k < line.size(); ++k) {
+            if (line[k] == '\"' && (k > 0 && line[k - 1] != '\\')) {
+                within_string = !within_string;
+            } else if (line[k] == '\\' && (k < line.size() - 1 && line[k + 1] == '\\')) {
+                comment_index = k;
                 break;
             }
         }
+
+        if (!StartsWith(line, "//") && comment_index != std::string::npos) {
+            last_comment = line.substr(comment_index + 2);
+            line = line.substr(0, comment_index);
+        }
+
+        if (StartsWith(line, "@stop")) {
+            // Force stop
+            break;
+        } else if (StartsWith(line, "@nsobid-")) {
+            // NSO Build ID Specifier
+            const auto raw_build_id = fmt::format("{:0<64}", line.substr(8));
+            nso_build_id = Common::HexStringToArray<0x20>(raw_build_id);
+        } else if (StartsWith(line, "#")) {
+            // Mandatory Comment
+            LOG_INFO(Loader, "[IPSwitchCompiler ('{}')] Forced output comment: {}",
+                     patch_text->GetName(), line.substr(1));
+        } else if (StartsWith(line, "//")) {
+            // Normal Comment
+            last_comment = line.substr(2);
+            if (last_comment.find_first_not_of(' ') == std::string::npos)
+                continue;
+            if (last_comment.find_first_not_of(' ') != 0)
+                last_comment = last_comment.substr(last_comment.find_first_not_of(' '));
+        } else if (StartsWith(line, "@enabled") || StartsWith(line, "@disabled")) {
+            // Start of patch
+            const auto enabled = StartsWith(line, "@enabled");
+            if (i == 0)
+                return;
+            LOG_INFO(Loader, "[IPSwitchCompiler ('{}')] Parsing patch '{}' ({})",
+                     patch_text->GetName(), last_comment, line.substr(1));
+
+            IPSwitchPatch patch{last_comment, enabled, {}};
+
+            // Read rest of patch
+            while (true) {
+                if (i + 1 >= lines.size()) {
+                    break;
+                }
+
+                const auto& patch_line = lines[++i];
+
+                // Patch line may contain comments
+                if (StartsWith(patch_line, "//") || StartsWith(patch_line, "#")) {
+                    continue;
+                }
+
+                // Start of new patch
+                if (StartsWith(patch_line, "@enabled") || StartsWith(patch_line, "@disabled")) {
+                    --i;
+                    break;
+                }
+
+                // Check for a flag
+                if (StartsWith(patch_line, "@")) {
+                    ParseFlag(patch_line);
+                    continue;
+                }
+
+                // 11 - 8 hex digit offset + space + minimum two digit overwrite val
+                if (patch_line.length() < 11)
+                    break;
+                auto offset = std::strtoul(patch_line.substr(0, 8).c_str(), nullptr, 16);
+                offset += static_cast<unsigned long>(offset_shift);
+
+                std::vector<u8> replace;
+                // 9 - first char of replacement val
+                if (patch_line[9] == '\"') {
+                    // string replacement
+                    auto end_index = patch_line.find('\"', 10);
+                    if (end_index == std::string::npos || end_index < 10)
+                        return;
+                    while (patch_line[end_index - 1] == '\\') {
+                        end_index = patch_line.find('\"', end_index + 1);
+                        if (end_index == std::string::npos || end_index < 10)
+                            return;
+                    }
+
+                    auto value = patch_line.substr(10, end_index - 10);
+                    value = EscapeStringSequences(value);
+                    replace.reserve(value.size());
+                    std::copy(value.begin(), value.end(), std::back_inserter(replace));
+                } else {
+                    // hex replacement
+                    const auto value =
+                        patch_line.substr(9, patch_line.find_first_of(" /\r\n", 9) - 9);
+                    replace = Common::HexStringToVector(value, is_little_endian);
+                }
+
+                if (print_values) {
+                    LOG_INFO(Loader,
+                             "[IPSwitchCompiler ('{}')]     - Patching value at offset {:#08x} "
+                             "with byte string '{}'",
+                             patch_text->GetName(), offset, Common::HexToString(replace));
+                }
+
+                patch.records.insert_or_assign(static_cast<u32>(offset), std::move(replace));
+            }
+
+            patches.push_back(std::move(patch));
+        } else if (StartsWith(line, "@")) {
+            ParseFlag(line);
+        }
     }
+
+    valid = true;
 }
 
 VirtualFile IPSwitchCompiler::Apply(const VirtualFile& in) const {
-    if (in == nullptr)
+    if (in == nullptr || !valid)
         return nullptr;
 
     auto in_data = in->ReadAllBytes();
 
     for (const auto& patch : patches) {
-        if (patch.enabled) {
-            for (const auto& record : patch.records) {
-                if (record.first < in_data.size()) {
-                    auto replace_size = record.second.count;
-                    if (record.first + replace_size > in_data.size())
-                        replace_size = in_data.size() - record.first;
-                    std::memcpy(in_data.data() + record.first, record.second.data.data(), replace_size);
-                }
-            }
+        if (!patch.enabled)
+            continue;
+
+        for (const auto& record : patch.records) {
+            if (record.first >= in_data.size())
+                continue;
+            auto replace_size = record.second.size();
+            if (record.first + replace_size > in_data.size())
+                replace_size = in_data.size() - record.first;
+            for (std::size_t i = 0; i < replace_size; ++i)
+                in_data[i + record.first] = record.second[i];
         }
     }
-    return std::make_shared<VectorVfsFile>(std::move(in_data), in->GetName(), in->GetContainingDirectory());
+
+    return std::make_shared<VectorVfsFile>(std::move(in_data), in->GetName(),
+                                           in->GetContainingDirectory());
 }
 
 } // namespace FileSys

src/core/file_sys/ips_layer.h

@@ -1,14 +1,11 @@
-// SPDX-FileCopyrightText: Copyright 2026 Eden Emulator Project
-// SPDX-License-Identifier: GPL-3.0-or-later
-
 // SPDX-FileCopyrightText: Copyright 2018 yuzu Emulator Project
 // SPDX-License-Identifier: GPL-2.0-or-later
 
 #pragma once
 
 #include <array>
+#include <memory>
 #include <vector>
-#include <span>
 
 #include "common/common_types.h"
 #include "core/file_sys/vfs/vfs.h"
@@ -23,17 +20,24 @@ public:
     ~IPSwitchCompiler();
 
     std::array<u8, 0x20> GetBuildID() const;
+    bool IsValid() const;
     VirtualFile Apply(const VirtualFile& in) const;
 
 private:
     struct IPSwitchPatch;
 
     void ParseFlag(const std::string& flag);
-    void Parse(std::span<u8 const> bytes);
+    void Parse();
+
+    bool valid = false;
 
     VirtualFile patch_text;
     std::vector<IPSwitchPatch> patches;
     std::array<u8, 0x20> nso_build_id{};
+    bool is_little_endian = false;
+    s64 offset_shift = 0;
+    bool print_values = false;
+    std::string last_comment = "";
 };
 
 } // namespace FileSys

src/core/file_sys/patch_manager.cpp

@@ -345,7 +345,8 @@ VirtualDir PatchManager::PatchExeFS(VirtualDir exefs) const {
     return exefs;
 }
 
-std::vector<VirtualFile> PatchManager::CollectPatches(const std::vector<VirtualDir>& patch_dirs, const std::string& build_id) const {
+std::vector<VirtualFile> PatchManager::CollectPatches(const std::vector<VirtualDir>& patch_dirs,
+                                                      const std::string& build_id) const {
     const auto& disabled = Settings::values.disabled_addons[title_id];
     const auto nso_build_id = fmt::format("{:0<64}", build_id);
 
@@ -360,11 +361,16 @@ std::vector<VirtualFile> PatchManager::CollectPatches(const std::vector<VirtualD
             for (const auto& file : exefs_dir->GetFiles()) {
                 if (file->GetExtension() == "ips") {
                     auto name = file->GetName();
-                    const auto this_build_id = fmt::format("{:0<64}", name.substr(0, name.find('.')));
+
+                    const auto this_build_id =
+                        fmt::format("{:0<64}", name.substr(0, name.find('.')));
                     if (nso_build_id == this_build_id)
                         out.push_back(file);
                 } else if (file->GetExtension() == "pchtxt") {
                     IPSwitchCompiler compiler{file};
+                    if (!compiler.IsValid())
+                        continue;
+
                     const auto this_build_id = Common::HexToString(compiler.GetBuildID());
                     if (nso_build_id == this_build_id)
                         out.push_back(file);
@@ -372,6 +378,7 @@ std::vector<VirtualFile> PatchManager::CollectPatches(const std::vector<VirtualD
             }
         }
     }
+
     return out;
 }
 

src/qt_common/util/mod.cpp

@@ -2,7 +2,6 @@
 // SPDX-License-Identifier: GPL-3.0-or-later
 
 #include <filesystem>
-#include <system_error>
 #include <JlCompress.h>
 #include "frontend_common/mod_manager.h"
 #include "mod.h"
@@ -125,8 +124,8 @@ const QString ExtractMod(const QString& path) {
     fs::remove_all(tmp, ec);
     if (!fs::create_directories(tmp, ec)) {
         QtCommon::Frontend::Critical(tr("Mod Extract Failed"),
-                                    tr("Failed to create temporary directory %1")
-                                        .arg(QString::fromStdString(tmp.string())));
+                                     tr("Failed to create temporary directory %1")
+                                         .arg(QString::fromStdString(tmp.string())));
         return QString();
     }