General.cpp

#include <atomic>
#include <cstdio>
#include <mutex>
#include <stdexcept>
#include <string>
#include <string_view>
#include <utility>
#include <vector>
#include <filesystem>
#include <optional>
#include <cerrno>
#include <cstring>
#include <map>
#include <memory>
#include <set>
#include <span>
#include <system_error>
#ifdef _WIN32
#ifndef NOMINMAX
#define NOMINMAX
#endif
#ifndef WIN32_LEAN_AND_MEAN
#define WIN32_LEAN_AND_MEAN
#endif
#include <windows.h>
#include <io.h>
#else
#include <ctime>
#include <fcntl.h>
#include <sys/stat.h>
#include <unistd.h>
#endif
#include "prx/libc/include/General.hpp"
#include "prx/libc/include/FilesystemError.hpp"
#include "prx/libc/include/AppArchive.hpp"
#include "prx/libc/include/ApplicationHeap.hpp"

namespace {
// Guest prefixes (without leading slashes) mapped to host directories, e.g. save-data mount points:
// the PS5 hands the title a short mount point ("/savedata0") whose files live under _sd/<dir name>.
struct PathAliases {
    std::mutex mutex;
    std::vector<std::pair<std::string, std::string>> entries;
    std::vector<std::string> blocked;
    std::vector<std::pair<std::string, PathProvider>> providers;
};

PathAliases& Aliases() {
    static auto* aliases = new PathAliases;
    return *aliases;
}

std::string TrimSlashes(const char* path) {
    std::string s(path);
    std::size_t start = 0;
    while (start < s.size() && (s[start] == '/' || s[start] == '\\')) {
        ++start;
    }
    std::size_t end = s.size();
    while (end > start && (s[end - 1] == '/' || s[end - 1] == '\\')) {
        --end;
    }
    return s.substr(start, end - start);
}

bool SameName(std::string_view left, std::string_view right) {
    if (left.size() != right.size()) return false;
    const auto fold = [](unsigned char value) { return value >= 'A' && value <= 'Z' ? value + ('a' - 'A') : value; };
    for (std::size_t i = 0; i < left.size(); ++i) if (fold(left[i]) != fold(right[i])) return false;
    return true;
}

bool HasPrefix(const std::string& path, const std::string& prefix) {
    return path.size() >= prefix.size() && SameName(std::string_view(path).substr(0, prefix.size()), prefix) &&
           (path.size() == prefix.size() || path[prefix.size()] == '/');
}

std::filesystem::path RelinkedModuleName(std::filesystem::path path) {
    path += ".guest.prx";
    return path;
}

struct NameMatch {
    std::string name;
    std::optional<std::filesystem::path> path;
    bool ambiguous = false;
};

std::error_code MatchNames(const std::filesystem::path& directory, std::span<NameMatch> names) {
    std::error_code error;
    std::filesystem::directory_iterator entry(directory, error), end;
    for (; !error && entry != end; entry.increment(error)) {
        const auto filename = entry->path().filename().string();
        for (auto& name : names) {
            if (!SameName(filename, name.name)) continue;
            name.ambiguous = name.ambiguous || name.path.has_value();
            name.path = entry->path();
        }
    }
    return error;
}

std::filesystem::path MatchedModuleOrPath(const std::filesystem::path& path, const std::filesystem::path& relinked, const NameMatch& match) {
    if (match.ambiguous) throw std::runtime_error("Ambiguous case-insensitive guest path: " + relinked.string());
    std::error_code error;
    return match.path && std::filesystem::is_regular_file(*match.path, error) ? *match.path : path;
}

std::filesystem::path PathOrRelinkedModule(const std::filesystem::path& path) {
    std::error_code error;
    if (std::filesystem::exists(std::filesystem::symlink_status(path, error))) return path;
    return RelinkedModulePath_nid_no_patch(path);
}

std::vector<std::string> SplitNames(std::string_view text) {
    std::vector<std::string> names;
    while (!text.empty()) {
        const auto separator = text.find('/');
        names.emplace_back(text.substr(0, separator));
        if (separator == std::string_view::npos) break;
        text.remove_prefix(separator + 1);
        if (text.empty()) names.emplace_back();
    }
    return names;
}

std::string JoinNames(const std::vector<std::string>& names) {
    std::string joined;
    for (std::size_t i = 0; i < names.size(); ++i) {
        if (i != 0) joined += '/';
        joined += names[i];
    }
    return joined;
}

std::filesystem::path Child(std::filesystem::path parent, const std::string& name) {
    parent /= "";
    parent += name;
    return parent;
}

std::filesystem::path ResolveHostPath(std::filesystem::path root, const std::vector<std::string>& relative, bool module = false) {
    const auto direct = Child(root, JoinNames(relative));
    std::error_code error;
    if (std::filesystem::exists(direct, error)) return direct;
    for (auto part = relative.begin(); part != relative.end(); ++part) {
        const auto candidate = Child(root, *part);
        const auto status = std::filesystem::symlink_status(candidate, error);
        if (std::filesystem::exists(status) || (error && error != std::errc::no_such_file_or_directory)) {
            root = candidate;
            continue;
        }
        const bool last = module && std::next(part) == relative.end();
        const auto relinked = RelinkedModuleName(candidate);
        NameMatch names[] = {{*part}, {relinked.filename().string()}};
        error = MatchNames(root, std::span(names, last ? 2 : 1));
        if (names[0].ambiguous) throw std::runtime_error("Ambiguous case-insensitive guest path: " + candidate.string());
        const bool matched = !error && names[0].path;
        root = matched ? *names[0].path : candidate;
        if (!last || matched) continue;
        if (std::filesystem::is_regular_file(relinked, error)) return relinked;
        return MatchedModuleOrPath(candidate, relinked, names[1]);
    }
    return module ? PathOrRelinkedModule(root) : root;
}

std::optional<std::filesystem::path> ResolveAlias(const std::string& guestPath, bool module) {
    const auto relative = TrimSlashes(guestPath.c_str());
    auto& aliases = Aliases();
    std::lock_guard lock(aliases.mutex);
    for (const auto& prefix : aliases.blocked) {
        if (HasPrefix(relative, prefix))
            throw std::filesystem::filesystem_error("Guest mount is unavailable", guestPath, std::make_error_code(std::errc::no_such_file_or_directory));
    }
    for (const auto& [prefix, host] : aliases.entries) {
        if (!HasPrefix(relative, prefix)) continue;
        if (relative.size() == prefix.size()) {
            const auto result = std::filesystem::path(host).make_preferred();
            return module ? PathOrRelinkedModule(result) : result;
        }
#ifndef _WIN32
        if (guestPath.back() == '/') {
            auto result = ResolveHostPath(host, SplitNames(std::string_view(relative).substr(prefix.size() + 1)));
            result /= "";
            return module ? PathOrRelinkedModule(result) : result;
        }
#endif
        return ResolveHostPath(host, SplitNames(std::string_view(relative).substr(prefix.size() + 1)), module).make_preferred();
    }
    return std::nullopt;
}

struct WorkingDirectory {
    std::mutex mutex;
    const std::filesystem::path root = std::filesystem::canonical(std::filesystem::current_path());
    std::filesystem::path current = root;
};
WorkingDirectory& Directories() {
    static auto* state = new WorkingDirectory;
    return *state;
}
std::optional<std::filesystem::path> ProvidedPath(const WorkingDirectory& state, const std::vector<std::string>& names) {
    const auto relative = TrimSlashes(JoinNames(names).c_str());
    PathProvider provide = nullptr;
    {
        auto& aliases = Aliases();
        std::lock_guard lock(aliases.mutex);
        for (const auto& [path, provider] : aliases.providers) {
            if (SameName(relative, path)) provide = provider;
        }
    }
    if (provide == nullptr) return std::nullopt;
    const auto supplied = ResolveHostPath(state.root, names);
    std::error_code error;
    if (std::filesystem::exists(supplied, error) || error) return supplied;
    auto provided = provide(state.root);
    if (provided.empty()) return std::nullopt;
    return provided.make_preferred();
}
std::filesystem::path HostPath(WorkingDirectory& state, const std::vector<std::string>& names, bool module = false) {
    if (auto aliased = ResolveAlias(JoinNames(names), module)) return *aliased;
    if (auto provided = ProvidedPath(state, names)) return *provided;
    return ResolveHostPath(state.root, names, module).make_preferred();
}
void RequireHostDirectory(WorkingDirectory& state, const std::vector<std::string>& names) {
    const auto host = HostPath(state, names);
    std::error_code error;
    const auto status = std::filesystem::status(host, error);
    if (std::filesystem::is_directory(status)) return;
    if (!error) error = std::make_error_code(std::filesystem::exists(status) ? std::errc::not_a_directory : std::errc::no_such_file_or_directory);
#ifdef _WIN32
    if (error == std::errc::no_such_file_or_directory) {
        for (auto prefix = host.parent_path(); prefix.has_relative_path(); prefix = prefix.parent_path()) {
            std::error_code prefixError;
            const auto prefixStatus = std::filesystem::status(prefix, prefixError);
            if (!std::filesystem::exists(prefixStatus)) continue;
            if (!std::filesystem::is_directory(prefixStatus)) error = std::make_error_code(std::errc::not_a_directory);
            break;
        }
    }
#endif
    throw std::filesystem::filesystem_error("Guest path component is not a directory", host, error);
}
std::vector<std::string> WithTrailingSeparator(std::vector<std::string> names, bool trailing) {
    if (trailing && !names.empty()) names.emplace_back();
    return names;
}
std::filesystem::path Resolve(WorkingDirectory& state, const char* path, bool module = false, bool archived = false) {
    std::string text(path);
    constexpr std::size_t MaxPath = 1024;
    constexpr std::size_t MaxName = 255;
    if (text.size() >= MaxPath) throw std::filesystem::filesystem_error("Guest path is too long", std::make_error_code(std::errc::filename_too_long));
    std::size_t name = 0;
    for (std::size_t index = 0; index < text.size(); ++index) {
        name = text[index] == '/' || text[index] == '\\' ? 0 : name + 1;
        if (name <= MaxName) continue;
        const std::size_t end = index + 1 - name;
        std::error_code status;
        if (end == 0 || std::filesystem::is_directory(Resolve(state, text.substr(0, end).c_str()), status)) {
            throw std::filesystem::filesystem_error("Guest path name is too long", std::make_error_code(std::errc::filename_too_long));
        }
        break;
    }
    for (auto& character : text) if (character == '\\') character = '/';
#ifdef _WIN32
    // Preserve the existing ability to pass explicit native drive paths.
    if (std::filesystem::path input(text); input.has_root_name()) return module ? PathOrRelinkedModule(input) : input;
#endif
    if (text.empty() || text.front() != '/') text = state.current.lexically_relative(state.root).generic_string() + "/" + text;
    std::vector<std::string> names;
    bool trailing = true;
    const auto parts = SplitNames(text);
    for (std::size_t i = 0; i < parts.size(); ++i) {
        const auto& name = parts[i];
        if (name.empty() && i + 1 != parts.size()) continue;
        if (name == ".." && !names.empty()) {
            if (!(archived && AppArchiveHasDirectory_nid_no_patch(HostPath(state, names)))) RequireHostDirectory(state, WithTrailingSeparator(names, trailing));
            names.pop_back();
        }
        trailing = name.empty() || name == "." || name == "..";
        if (!trailing) names.push_back(name);
    }
    return HostPath(state, WithTrailingSeparator(std::move(names), trailing), module);
}
#ifdef _WIN32
using WriteMark = FILETIME;
WriteMark Now() {
    FILETIME now;
    GetSystemTimeAsFileTime(&now);
    return now;
}
bool NotBefore(const WriteMark& time, const WriteMark& mark) {
    return CompareFileTime(&time, &mark) >= 0;
}
#else
using WriteMark = timespec;
WriteMark Now() {
    timespec now;
    clock_gettime(CLOCK_REALTIME_COARSE, &now);
    return now;
}
bool NotBefore(const WriteMark& time, const WriteMark& mark) {
    if (time.tv_sec == mark.tv_sec) return time.tv_nsec >= mark.tv_nsec;
    return time.tv_sec >= mark.tv_sec;
}
#endif
struct WrittenPathRegistry {
    std::mutex syncMutex;
    std::mutex mutex;
    std::map<std::filesystem::path, bool> dirty;
    WriteMark mark = Now();
};
WrittenPathRegistry& Written() { static WrittenPathRegistry registry; return registry; }
#ifdef _WIN32
std::optional<WriteMark> WriteTime(const std::filesystem::path& path) {
    WIN32_FILE_ATTRIBUTE_DATA data;
    if (GetFileAttributesExW(path.c_str(), GetFileExInfoStandard, &data)) return data.ftLastWriteTime;
    const auto error = GetLastError();
    if (error == ERROR_FILE_NOT_FOUND || error == ERROR_PATH_NOT_FOUND) return std::nullopt;
    throw std::system_error(static_cast<int>(error), std::system_category(), "Reading the write time of " + path.string());
}
void FlushPath(const std::filesystem::path& path) {
    const auto handle = CreateFileW(path.c_str(), GENERIC_WRITE, FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE, nullptr,
        OPEN_EXISTING, FILE_FLAG_BACKUP_SEMANTICS, nullptr);
    if (handle == INVALID_HANDLE_VALUE) {
        const auto error = GetLastError();
        if (error == ERROR_FILE_NOT_FOUND || error == ERROR_PATH_NOT_FOUND) return;
        if (error == ERROR_ACCESS_DENIED || error == ERROR_SHARING_VIOLATION) return;
        throw std::system_error(static_cast<int>(error), std::system_category(), "Opening " + path.string() + " for sync");
    }
    const std::unique_ptr<void, decltype(&CloseHandle)> owner(handle, &CloseHandle);
    if (!FlushFileBuffers(handle))
        throw std::system_error(static_cast<int>(GetLastError()), std::system_category(), "Flushing " + path.string());
}
#else
std::optional<WriteMark> WriteTime(const std::filesystem::path& path) {
    struct stat data;
    if (::stat(path.c_str(), &data) == 0) return data.st_mtim;
    if (errno == ENOENT || errno == ENOTDIR) return std::nullopt;
    throw std::system_error(errno, std::generic_category(), "Reading the write time of " + path.string());
}
void FlushPath(const std::filesystem::path& path) {
    const int descriptor = ::open(path.c_str(), O_RDONLY | O_NONBLOCK | O_CLOEXEC);
    if (descriptor < 0) {
        if (errno == ENOENT || errno == ENOTDIR || errno == EACCES) return;
        throw std::system_error(errno, std::generic_category(), "Opening " + path.string() + " for sync");
    }
    const int result = ::fsync(descriptor);
    const int error = errno;
    ::close(descriptor);
    if (result != 0 && error != EINVAL) throw std::system_error(error, std::generic_category(), "Flushing " + path.string());
}
#endif
bool ChangedSince(const std::filesystem::path& path, const WriteMark& mark) {
    const auto time = WriteTime(path);
    return time && NotBefore(*time, mark);
}
int DirectoryFailure(const std::error_code& error) {
    if (error == std::errc::permission_denied) return 13;
    if (error == std::errc::not_a_directory) return 20;
    if (error == std::errc::no_such_file_or_directory) return 2;
    if (error == std::errc::filename_too_long) return 63;
    if (error == std::errc::too_many_symbolic_link_levels) return 62;
    return 5;
}
int SetWorkingDirectory(WorkingDirectory& state, const std::filesystem::path& resolved) {
    std::error_code error;
    const auto canonical = std::filesystem::canonical(resolved, error);
    if (error) return DirectoryFailure(error);
    if (!std::filesystem::is_directory(canonical, error)) return error ? DirectoryFailure(error) : 20;
    auto relative = canonical.lexically_relative(state.root);
#ifdef _WIN32
    if (relative.empty() || *relative.begin() == "..") {
        auto ancestor = canonical;
        while (!std::filesystem::equivalent(ancestor, state.root, error)) {
            if (error) return DirectoryFailure(error);
            const auto parent = ancestor.parent_path();
            if (parent == ancestor) return 45;
            ancestor = parent;
        }
        relative = canonical.lexically_relative(ancestor);
    }
#endif
    if (relative.empty() || *relative.begin() == "..") return 45;
#ifdef _WIN32
    state.current = relative == "." ? state.root : state.root / relative;
#else
    state.current = canonical;
#endif
    return 0;
}
}

#ifndef _WIN32
namespace {
std::mutex g_hostStandardErrorMutex;
std::atomic<int> g_hostStandardError{-1};
}

extern "C" int KeepHostStandardError_nid_no_patch() {
    const std::lock_guard lock(g_hostStandardErrorMutex);
    if (const int kept = g_hostStandardError.load(); kept >= 0) return kept;
    const int kept = ::fcntl(2, F_DUPFD_CLOEXEC, 3);
    if (kept < 0) {
        if (errno == EBADF) return -1;
        throw std::system_error(errno, std::generic_category(), "Keeping the host standard error");
    }
    std::FILE* const stream = ::fdopen(kept, "w");
    if (stream == nullptr) {
        const int error = errno;
        ::close(kept);
        throw std::system_error(error, std::generic_category(), "Keeping the host standard error");
    }
    std::setvbuf(stream, nullptr, _IONBF, 0);
    std::fflush(stderr);
    stderr = stream;
    g_hostStandardError.store(kept);
    return kept;
}

extern "C" int HostStandardError_nid_no_patch() {
    return g_hostStandardError.load();
}

extern "C" int DuplicateHostDescriptor_nid_no_patch(int descriptor) {
    return ::fcntl(descriptor, F_DUPFD_CLOEXEC, 3);
}
#endif

extern "C" void AddPathAlias_nid_no_patch(const char* guestPrefix, const char* hostPath) {
    if (guestPrefix == nullptr || hostPath == nullptr) {
        APS5_INVALID_ARG_EX;
    }
    auto& aliases = Aliases();
    std::lock_guard lock(aliases.mutex);
    const auto prefix = TrimSlashes(guestPrefix);
    std::erase_if(aliases.blocked, [&](const auto& entry) { return SameName(entry, prefix); });
    for (auto& entry : aliases.entries) {
        if (SameName(entry.first, prefix)) {
            entry.second = hostPath;
            return;
        }
    }
    aliases.entries.emplace_back(prefix, hostPath);
}

extern "C" void AddPathProvider_nid_no_patch(const char* guestPath, PathProvider provide) {
    if (guestPath == nullptr || provide == nullptr) {
        APS5_INVALID_ARG_EX;
    }
    const auto path = TrimSlashes(guestPath);
    if (path.empty()) { APS5_INVALID_ARG_EX; }
    auto& aliases = Aliases();
    std::lock_guard lock(aliases.mutex);
    for (auto& entry : aliases.providers) {
        if (SameName(entry.first, path)) {
            entry.second = provide;
            return;
        }
    }
    aliases.providers.emplace_back(path, provide);
}

extern "C" void RemovePathAlias_nid_no_patch(const char* guestPrefix) {
    if (guestPrefix == nullptr) {
        APS5_INVALID_ARG_EX;
    }
    auto& aliases = Aliases();
    std::lock_guard lock(aliases.mutex);
    const auto prefix = TrimSlashes(guestPrefix);
    std::erase_if(aliases.entries, [&](const auto& entry) { return SameName(entry.first, prefix); });
}

extern "C" void RecordWrittenPath_nid_no_patch(const std::filesystem::path& path) {
    auto& registry = Written();
    std::lock_guard lock(registry.mutex);
    registry.dirty[path.lexically_normal()] = true;
}

extern "C" std::vector<std::filesystem::path> WrittenPaths_nid_no_patch() {
    auto& registry = Written();
    std::lock_guard lock(registry.mutex);
    std::vector<std::filesystem::path> paths;
    for (const auto& entry : registry.dirty) paths.push_back(entry.first);
    return paths;
}

extern "C" void SyncWrittenPaths_nid_no_patch() {
    auto& registry = Written();
    std::lock_guard serial(registry.syncMutex);
    const auto start = Now();
    WriteMark mark;
    std::vector<std::pair<std::filesystem::path, bool>> entries;
    {
        std::lock_guard lock(registry.mutex);
        mark = registry.mark;
        registry.mark = start;
        for (auto& [path, dirty] : registry.dirty) {
            entries.emplace_back(path, dirty);
            dirty = false;
        }
    }
    std::set<std::filesystem::path> flushed;
    std::vector<std::filesystem::path> missing;
    for (const auto& [path, dirty] : entries) {
        const auto time = WriteTime(path);
        if (!time) missing.push_back(path);
        if (!dirty && !(time && NotBefore(*time, mark))) continue;
        if (time && flushed.insert(path).second) FlushPath(path);
        for (auto ancestor = path.parent_path(); ancestor.has_relative_path() && !flushed.contains(ancestor) && ChangedSince(ancestor, mark);
             ancestor = ancestor.parent_path()) {
            flushed.insert(ancestor);
            FlushPath(ancestor);
        }
    }
    std::lock_guard lock(registry.mutex);
    for (const auto& path : missing) {
        const auto entry = registry.dirty.find(path);
        if (entry != registry.dirty.end() && !entry->second) registry.dirty.erase(entry);
    }
}

extern "C" void BlockPathAlias_nid_no_patch(const char* guestPrefix) {
    if (guestPrefix == nullptr) { APS5_INVALID_ARG_EX; }
    const auto prefix = TrimSlashes(guestPrefix);
    if (prefix.empty()) { APS5_INVALID_ARG_EX; }
    auto& aliases = Aliases();
    std::lock_guard lock(aliases.mutex);
    std::erase_if(aliases.entries, [&](const auto& entry) { return SameName(entry.first, prefix); });
    std::erase_if(aliases.blocked, [&](const auto& entry) { return SameName(entry, prefix); });
    aliases.blocked.push_back(prefix);
}

static std::filesystem::path ResolveLocked(const char* path, bool module, bool archived) {
    if (!path) { APS5_INVALID_ARG_EX; }
    if (archived) AppArchiveReady_nid_no_patch();
    auto& state = Directories();
    std::lock_guard lock(state.mutex);
    return Resolve(state, path, module, archived);
}

extern "C" std::filesystem::path ResolveDiskPath_nid_no_patch(const char* path) {
    return ResolveLocked(path, false, false);
}

extern "C" std::filesystem::path ResolveArchivedPath_nid_no_patch(const char* path, bool module) {
    return ResolveLocked(path, module, true);
}

extern "C" std::filesystem::path ResolvePath_nid_no_patch(const char* path) {
    auto resolved = ResolveLocked(path, false, true);
    AppArchiveRefuseOnly_nid_no_patch(resolved, path, "reading");
    return resolved;
}

extern "C" std::filesystem::path ResolvePathOrRelinkedModule_nid_no_patch(const char* path) {
    auto resolved = ResolveLocked(path, true, true);
    AppArchiveRefuseOnly_nid_no_patch(resolved, path, "reading");
    return resolved;
}

extern "C" std::filesystem::path RelinkedModulePath_nid_no_patch(const std::filesystem::path& path) {
    const auto relinked = RelinkedModuleName(path);
    std::error_code error;
    if (std::filesystem::is_regular_file(relinked, error)) return relinked;
    NameMatch names[] = {{relinked.filename().string()}};
    MatchNames(relinked.parent_path().empty() ? "." : relinked.parent_path(), names);
    return MatchedModuleOrPath(path, relinked, names[0]);
}

extern "C" int SetWorkingDirectory_nid_no_patch(const char* resolved) {
    if (resolved == nullptr) return 14;
    auto& state = Directories();
    std::lock_guard lock(state.mutex);
    try {
        return SetWorkingDirectory(state, std::filesystem::path(reinterpret_cast<const char8_t*>(resolved)));
    } catch (const std::bad_alloc&) {
        return 12;
    } catch (const std::filesystem::filesystem_error& error) {
        return DirectoryFailure(error.code());
    }
}

extern "C" bool FinalPathComponentIsDot_nid_no_patch(const char* path) {
    std::string_view text(path);
    while (!text.empty() && (text.back() == '/' || text.back() == '\\')) text.remove_suffix(1);
    const auto separator = text.find_last_of("/\\");
    const auto component = text.substr(separator == std::string_view::npos ? 0 : separator + 1);
    return component == ".";
}

extern "C" int APS5_VABI chdir_nid_postfix(const char* path) {
    if (!path) { errno = 14; return -1; }
    if (!*path) { errno = 2; return -1; }
    try {
        AppArchiveReady_nid_no_patch();
        auto& state = Directories();
        std::lock_guard lock(state.mutex);
        const auto resolved = Resolve(state, path, false, true);
        AppArchiveRefuseOnly_nid_no_patch(resolved, path, "changing the working directory to");
        const int error = SetWorkingDirectory(state, resolved);
        if (error) { errno = error == 2 ? NotFoundError_nid_no_patch(resolved) : error; return -1; }
        return 0;
    } catch (const std::bad_alloc&) { errno = 12; return -1; }
      catch (const std::filesystem::filesystem_error& error) { errno = DirectoryFailure(error.code()); return -1; }
}

extern "C" char* APS5_VABI getcwd_nid_postfix(char* buffer, std::size_t size) {
    if (buffer && size == 0) { errno = 22; return nullptr; }
    try {
        auto& state = Directories();
        std::lock_guard lock(state.mutex);
        std::error_code error;
        if (!std::filesystem::is_directory(state.current, error)) {
            errno = error ? DirectoryFailure(error) : 2; return nullptr;
        }
        const auto relative = state.current.lexically_relative(state.root);
        const auto path = relative == "." ? std::string("/") : "/" + relative.generic_string();
        const auto required = path.size() + 1;
        if (buffer && size < required) { errno = 34; return nullptr; }
        if (!buffer) buffer = static_cast<char*>(ApplicationHeapAllocate_nid_no_patch(required));
        if (!buffer) { errno = 12; return nullptr; }
        std::memcpy(buffer, path.c_str(), required);
        return buffer;
    } catch (const std::bad_alloc&) { errno = 12; return nullptr; }
      catch (const std::filesystem::filesystem_error& error) { errno = DirectoryFailure(error.code()); return nullptr; }
}

#ifdef _WIN32
extern "C" int WindowsOpenError_nid_no_patch(unsigned long error) {
    switch (error) {
    case ERROR_FILE_NOT_FOUND:
    case ERROR_PATH_NOT_FOUND:
    case ERROR_INVALID_DRIVE:
    case ERROR_BAD_NETPATH:
    case ERROR_BAD_NET_NAME:
    case ERROR_BAD_PATHNAME:
    case ERROR_FILENAME_EXCED_RANGE:
        return ENOENT;
    case ERROR_ACCESS_DENIED:
    case ERROR_SHARING_VIOLATION:
    case ERROR_LOCK_VIOLATION:
    case ERROR_WRITE_PROTECT:
    case ERROR_NETWORK_ACCESS_DENIED:
    case ERROR_CANNOT_MAKE:
    case ERROR_DRIVE_LOCKED:
        return EACCES;
    case ERROR_FILE_EXISTS:
    case ERROR_ALREADY_EXISTS:
        return EEXIST;
    case ERROR_TOO_MANY_OPEN_FILES:
        return EMFILE;
    case ERROR_NOT_ENOUGH_MEMORY:
    case ERROR_OUTOFMEMORY:
        return ENOMEM;
    case ERROR_DISK_FULL:
        return ENOSPC;
    default:
        return EINVAL;
    }
}

extern "C" _invalid_parameter_handler _set_thread_local_invalid_parameter_handler(_invalid_parameter_handler);
static DWORD StandardHandleId(int descriptor) {
    return descriptor == 0 ? STD_INPUT_HANDLE : descriptor == 1 ? STD_OUTPUT_HANDLE : STD_ERROR_HANDLE;
}
extern "C" void* HostStandardHandle_nid_no_patch(int descriptor) {
    if (descriptor < 0 || descriptor > 2) return nullptr;
    const HANDLE current = GetStdHandle(StandardHandleId(descriptor));
    if (current == nullptr || current == INVALID_HANDLE_VALUE) return nullptr;
    const auto previous = _set_thread_local_invalid_parameter_handler([](const wchar_t*, const wchar_t*, const wchar_t*, unsigned int, std::uintptr_t) {});
    const auto owned = ::_get_osfhandle(descriptor);
    _set_thread_local_invalid_parameter_handler(previous);
    if (reinterpret_cast<HANDLE>(owned) != current) return current;
    HANDLE kept = nullptr;
    if (!DuplicateHandle(GetCurrentProcess(), current, GetCurrentProcess(), &kept, 0, TRUE, DUPLICATE_SAME_ACCESS))
        throw std::runtime_error("Cannot keep the host standard handle of descriptor " + std::to_string(descriptor));
    return kept;
}
extern "C" void KeepStandardHandle_nid_no_patch(int descriptor, void* handle) {
    if (handle != nullptr && !SetStdHandle(StandardHandleId(descriptor), handle))
        throw std::runtime_error("Cannot keep the host standard handle of descriptor " + std::to_string(descriptor));
}
extern "C" int DuplicateHostDescriptor_nid_no_patch(int descriptor) {
    const auto previous = _set_thread_local_invalid_parameter_handler([](const wchar_t*, const wchar_t*, const wchar_t*, unsigned int, std::uintptr_t) {});
    const int kept = ::_dup(descriptor);
    _set_thread_local_invalid_parameter_handler(previous);
    return kept;
}
#endif

extern "C" [[noreturn]] void NotImplemented_nid_no_patch(const char* funcName) {
    throw std::runtime_error(std::string(funcName) + " not implemented");
}