log_filepath.hpp

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#pragma once
 
/// @file userver/logging/log_filepath.hpp
/// @brief Short source path calculator
 
#include <string_view>
 
USERVER_NAMESPACE_BEGIN
 
#if !defined(USERVER_LOG_PREFIX_PATH_BASE) && !defined(USERVER_LOG_SOURCE_PATH_BASE) &&
    !defined(USERVER_LOG_BUILD_PATH_BASE)
 
/// @ingroup userver_universal
///
/// @brief Short std::string_view with source path for logging.
/// @hideinitializer
// We need user's filename here, not ours
// NOLINTNEXTLINE(cppcoreguidelines-macro-usage)
#define USERVER_FILEPATH
    std::string_view { __builtin_FILE() }
 
#else
 
namespace logging::impl {
 
// I know no other way to wrap a macro value in quotes
// NOLINTNEXTLINE(cppcoreguidelines-macro-usage)
#define USERVER_LOG_FILEPATH_STRINGIZE_AUX(X) #X
// NOLINTNEXTLINE(cppcoreguidelines-macro-usage)
#define USERVER_LOG_FILEPATH_STRINGIZE(X) USERVER_LOG_FILEPATH_STRINGIZE_AUX(X)
 
// May have different macro values for different translation units, hence static
static constexpr std::size_t PathBaseSize(std::string_view path) noexcept {
    constexpr std::string_view kSourcePathPrefixes[] = {
#ifdef USERVER_LOG_PREFIX_PATH_BASE
        USERVER_LOG_FILEPATH_STRINGIZE(USERVER_LOG_PREFIX_PATH_BASE),
#endif
#ifdef USERVER_LOG_SOURCE_PATH_BASE
        USERVER_LOG_FILEPATH_STRINGIZE(USERVER_LOG_SOURCE_PATH_BASE),
#endif
#ifdef USERVER_LOG_BUILD_PATH_BASE
        USERVER_LOG_FILEPATH_STRINGIZE(USERVER_LOG_BUILD_PATH_BASE),
#endif
    };
 
    for (const std::string_view base : kSourcePathPrefixes) {
        if (path.substr(0, base.size()) == base) {
            std::size_t base_size = path.find_first_not_of('/', base.size());
            if (base_size == std::string_view::npos) {
                base_size = path.size();
            }
 
            return base_size;
        }
    }
    return 0;
}
 
// TODO: consteval
static constexpr std::string_view CutFilePath(const char* path) noexcept {
    const std::string_view path_view = path;
    return path_view.substr(impl::PathBaseSize(path_view));
}
 
#undef USERVER_LOG_FILEPATH_STRINGIZE
#undef USERVER_LOG_FILEPATH_STRINGIZE_AUX
 
}  // namespace logging::impl
 
// NOLINTNEXTLINE(cppcoreguidelines-macro-usage)
#define USERVER_FILEPATH USERVER_NAMESPACE::logging::impl::CutFilePath(__builtin_FILE())
 
#endif
 
USERVER_NAMESPACE_END