safa-api 0.4.3

A high-level API over SafaOS's syscalls
Documentation 
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pub(crate) trait IntoSyscallArg {
    type RegResults;
    fn into_syscall_arg(self) -> Self::RegResults;
}

macro_rules! impl_into_syscall_as {
    ($ty:ty) => {
        impl IntoSyscallArg for $ty {
            type RegResults = (usize,);
            #[inline(always)]
            fn into_syscall_arg(self) -> (usize,) {
                (self as usize,)
            }
        }
    };
}

impl_into_syscall_as!(usize);
impl_into_syscall_as!(isize);
impl_into_syscall_as!(u8);
impl_into_syscall_as!(i8);
impl_into_syscall_as!(u16);
impl_into_syscall_as!(i16);
impl_into_syscall_as!(u32);
impl_into_syscall_as!(i32);
impl_into_syscall_as!(u64);
impl_into_syscall_as!(i64);
impl_into_syscall_as!(u128);
impl_into_syscall_as!(i128);
impl_into_syscall_as!(bool);

impl IntoSyscallArg for (usize,) {
    type RegResults = (usize,);

    #[inline(always)]
    fn into_syscall_arg(self) -> (usize,) {
        self
    }
}

impl<T> IntoSyscallArg for *const T {
    type RegResults = (usize,);

    #[inline(always)]
    fn into_syscall_arg(self) -> (usize,) {
        (self as usize,)
    }
}

impl<T> IntoSyscallArg for *mut T {
    type RegResults = (usize,);

    #[inline(always)]
    fn into_syscall_arg(self) -> (usize,) {
        (self as usize,)
    }
}

impl IntoSyscallArg for safa_abi::fs::OpenOptions {
    type RegResults = (usize,);

    #[inline(always)]
    fn into_syscall_arg(self) -> (usize,) {
        let bits: u8 = unsafe { core::mem::transmute(self) };
        bits.into_syscall_arg()
    }
}

impl<T> IntoSyscallArg for Slice<T> {
    type RegResults = (usize, usize);

    #[inline(always)]
    fn into_syscall_arg(self) -> (usize, usize) {
        (self.as_ptr() as usize, self.len())
    }
}

impl IntoSyscallArg for Str {
    type RegResults = (usize, usize);

    #[inline(always)]
    fn into_syscall_arg(self) -> (usize, usize) {
        (self.as_ptr() as usize, self.len())
    }
}

impl<T> IntoSyscallArg for FFINonNull<T> {
    type RegResults = (usize,);
    fn into_syscall_arg(self) -> Self::RegResults {
        (self.as_ptr() as usize,)
    }
}

impl<T: NotZeroable + IntoSyscallArg> IntoSyscallArg for OptZero<T> {
    type RegResults = T::RegResults;
    fn into_syscall_arg(self) -> Self::RegResults {
        let inner = unsafe { self.into_inner_unchecked() };
        inner.into_syscall_arg()
    }
}

use safa_abi::ffi::option::OptZero;
use safa_abi::ffi::{ptr::FFINonNull, slice::Slice, str::Str};

use safa_abi::ffi::NotZeroable;

use crate::errors::ErrorStatus;

/// A nullable muttable pointer to `T`
///
/// guaranteed to be accepted by the syscall if it is null,
/// however the syscall will return [`ErrorStatus::InvalidPtr`] if it is not aligned to `align_of::<T>()`
///
/// this is typically for the syscall to return optional values
pub type OptionalPtrMut<T> = OptZero<RequiredPtrMut<T>>;

/// A nullable imuttable pointer to `T`
///
/// guaranteed to be accepted by the syscall if it is null,
/// however the syscall will return [`ErrorStatus::InvalidPtr`] if it is not aligned to `align_of::<T>()`
///
/// this is typically for the syscall to return optional values
pub type OptionalPtr<T> = OptZero<RequiredPtr<T>>;

/// A muttable pointer to `T`
///
/// the syscall will return [`ErrorStatus::InvalidPtr`] if it is not aligned to `align_of::<T>()` or if it is null
///
/// typically used for the syscall to return a value
pub type RequiredPtrMut<T> = FFINonNull<T>;

/// An immuttable pointer to `T`
///
/// the syscall will return [`ErrorStatus::InvalidPtr`] if it is not aligned to `align_of::<T>()` or if it is null
///
/// typically used for the syscall to return a value
pub type RequiredPtr<T> = FFINonNull<T>;

/// An optional immuttable nullable utf8 byte slice
///
/// the syscall will return [`ErrorStatus::InvalidStr`] if it is not null and is not valid utf-8
///
/// typically followed by a `len` parameter to specify the length of the string
///
/// can be null
pub type OptionalStr = OptZero<Str>;

/// An optional muttable nullable utf8 byte slice
///
/// the syscall will return [`ErrorStatus::InvalidStr`] if it is not null and is not valid utf-8
///
/// typically followed by a `len` parameter to specify the length of the string
///
/// can be null
pub type OptionalStrMut = OptZero<Str>;

/// An opaque type that represents a syscall result
/// the underlying type is a 16 bit unsigned integer, in which 0 is success and any other value is in error
/// represented by the [`ErrorStatus`] enum
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
#[repr(transparent)]
pub struct SyscallResult(u16);

impl SyscallResult {
    #[inline(always)]
    pub const fn into_result(self) -> Result<(), ErrorStatus> {
        match self.0 {
            0 => Ok(()),
            x => unsafe { Err(core::mem::transmute(x)) },
        }
    }

    #[inline(always)]
    pub const fn is_success(self) -> bool {
        self.0 == 0
    }
}

/// A process ID
pub type Pid = u32;
/// A thread ID
pub type Cid = u32;

/// A resource id
/// this is a generic type that can be used to represent any resource (file, directory, device, directory iterator, etc.)
pub type Ri = usize;