gplib/extra_tests/001_test/syscall.hpp

#pragma once
#include <cstdint>
#include <cstddef>
#include <gp/containers/buffer.hpp>

template<int64_t syscall_id, int arg_count>
struct syscall;

template<int64_t syscall_id>
struct syscall<syscall_id, 1> {
    int64_t operator()(int64_t p1) const {
        int64_t ret;
        asm volatile
        (
            "syscall"
            : "=a" (ret)
            : "0"(syscall_id), "D"(p1)
            : "rcx", "r11", "memory"
        );
        return ret;
    }
};

template<int64_t syscall_id>
struct syscall<syscall_id, 2> {
    int64_t operator()(int64_t p1,int64_t p2) const {
        int64_t ret;
        asm volatile
        (
            "syscall"
            : "=a" (ret)
            : "0"(syscall_id), "D"(p1), "S"(p2)
            : "rcx", "r11", "memory"
        );
        return ret;
    }
};

template<int64_t syscall_id>
struct syscall<syscall_id, 3> {
    int64_t operator()(int64_t p1,int64_t p2,int64_t p3) const {
        int64_t ret;
        asm volatile
        (
            "syscall"
            : "=a" (ret)
            : "0"(syscall_id), "D"(p1), "S"(p2), "d"(p3)
            : "rcx", "r11", "memory"
        );
        return ret;
    }
};

constexpr auto _read = syscall<0, 3>{};
constexpr auto _write = syscall<1, 3>{};
constexpr auto _exit = syscall<60, 1>{};

inline int read(int fd, char* buffer, size_t sz) {
    return _read((int64_t)fd, (int64_t)buffer, (int64_t)sz);
}

inline int write(int fd, char* buffer, size_t sz) {
    return _write((int64_t)fd, (int64_t)buffer, (int64_t)sz);
}

inline int read(int fd, gp::buffer<char> buffer) {
    return _read((int64_t)fd, (int64_t)buffer.begin().data, (int64_t)buffer.size());
}

inline int write(int fd, gp::buffer<char> buffer) {
    return _write((int64_t)fd, (int64_t)buffer.begin().data, (int64_t)buffer.size());
}

extern "C" {

inline __attribute__ ((__noreturn__)) void exit(int status) {
    _exit((int64_t)status);
    while(true);
}

}