os.hpp

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#pragma once
 
#include <asmgrader/common/aliases.hpp>
 
#include <libassert/assert.hpp>
 
#include <bit>
 
namespace asmgrader {
 
// NOLINTNEXTLINE(readability-identifier-naming)
enum class ProcessorKind { Aarch64, x86_64 };
 
#if defined(__aarch64__)
#define ASMGRADER_AARCH64
constexpr auto SYSTEM_PROCESSOR = ProcessorKind::Aarch64;
#elif defined(__x86_64__)
#define ASMGRADER_X86_64
constexpr auto SYSTEM_PROCESSOR = ProcessorKind::x86_64;
#else
#error "Unsupported system architecture!"
#endif
 
consteval bool is_little_endian() {
    struct S
    {
        u8 msb;
        u8 lsb;
    };
 
    static_assert(sizeof(S) == 2, "Strange, unsupported system. struct { u8; u8; } is not packed as 2 bytes.");
 
    u16 one = 0x00'01;
 
    auto check = std::bit_cast<S>(one);
 
    if (check.msb == 1 && check.lsb == 0) {
        return true;
    }
    if (check.msb == 0 && check.lsb == 1) {
        return false;
    }
 
    UNREACHABLE("Unsupported system endianness!");
}
 
enum class EndiannessKind { Little = 0, Big = 1, Native = (is_little_endian() ? Little : Big) };
 
} // namespace asmgrader