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use super::chars::{Char16, Char8, NUL_16, NUL_8};
use super::UnalignedSlice;
use crate::polyfill::maybe_uninit_slice_assume_init_ref;
use core::borrow::Borrow;
use core::ffi::CStr;
use core::fmt::{self, Display, Formatter};
use core::mem::MaybeUninit;
use core::slice;
#[cfg(feature = "alloc")]
use super::CString16;
/// Errors which can occur during checked `[uN]` -> `CStrN` conversions
#[derive(Clone, Copy, Debug, Eq, PartialEq)]
pub enum FromSliceWithNulError {
/// An invalid character was encountered before the end of the slice
InvalidChar(usize),
/// A null character was encountered before the end of the slice
InteriorNul(usize),
/// The slice was not null-terminated
NotNulTerminated,
}
impl Display for FromSliceWithNulError {
fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
match self {
Self::InvalidChar(usize) => write!(f, "invalid character at index {}", usize),
Self::InteriorNul(usize) => write!(f, "interior null character at index {}", usize),
Self::NotNulTerminated => write!(f, "not null-terminated"),
}
}
}
#[cfg(feature = "unstable")]
impl core::error::Error for FromSliceWithNulError {}
/// Error returned by [`CStr16::from_unaligned_slice`].
#[derive(Clone, Copy, Debug, Eq, PartialEq)]
pub enum UnalignedCStr16Error {
/// An invalid character was encountered.
InvalidChar(usize),
/// A null character was encountered before the end of the data.
InteriorNul(usize),
/// The data was not null-terminated.
NotNulTerminated,
/// The buffer is not big enough to hold the entire string and
/// trailing null character.
BufferTooSmall,
}
impl Display for UnalignedCStr16Error {
fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
match self {
Self::InvalidChar(usize) => write!(f, "invalid character at index {}", usize),
Self::InteriorNul(usize) => write!(f, "interior null character at index {}", usize),
Self::NotNulTerminated => write!(f, "not null-terminated"),
Self::BufferTooSmall => write!(f, "buffer too small"),
}
}
}
#[cfg(feature = "unstable")]
impl core::error::Error for UnalignedCStr16Error {}
/// Error returned by [`CStr16::from_str_with_buf`].
#[derive(Clone, Copy, Debug, Eq, PartialEq)]
pub enum FromStrWithBufError {
/// An invalid character was encountered before the end of the string
InvalidChar(usize),
/// A null character was encountered in the string
InteriorNul(usize),
/// The buffer is not big enough to hold the entire string and
/// trailing null character
BufferTooSmall,
}
impl Display for FromStrWithBufError {
fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
match self {
Self::InvalidChar(usize) => write!(f, "invalid character at index {}", usize),
Self::InteriorNul(usize) => write!(f, "interior null character at index {}", usize),
Self::BufferTooSmall => write!(f, "buffer too small"),
}
}
}
#[cfg(feature = "unstable")]
impl core::error::Error for FromStrWithBufError {}
/// A null-terminated Latin-1 string.
///
/// This type is largely inspired by [`core::ffi::CStr`] with the exception that all characters are
/// guaranteed to be 8 bit long.
///
/// A [`CStr8`] can be constructed from a [`core::ffi::CStr`] via a `try_from` call:
/// ```ignore
/// let cstr8: &CStr8 = TryFrom::try_from(cstr).unwrap();
/// ```
///
/// For convenience, a [`CStr8`] is comparable with [`core::str`] and
/// `alloc::string::String` from the standard library through the trait [`EqStrUntilNul`].
#[repr(transparent)]
#[derive(Eq, PartialEq, Ord, PartialOrd, Hash)]
pub struct CStr8([Char8]);
impl CStr8 {
/// Takes a raw pointer to a null-terminated Latin-1 string and wraps it in a CStr8 reference.
///
/// # Safety
///
/// The function will start accessing memory from `ptr` until the first
/// null byte. It's the callers responsibility to ensure `ptr` points to
/// a valid null-terminated string in accessible memory.
#[must_use]
pub unsafe fn from_ptr<'ptr>(ptr: *const Char8) -> &'ptr Self {
let mut len = 0;
while *ptr.add(len) != NUL_8 {
len += 1
}
let ptr = ptr.cast::<u8>();
Self::from_bytes_with_nul_unchecked(slice::from_raw_parts(ptr, len + 1))
}
/// Creates a CStr8 reference from bytes.
pub fn from_bytes_with_nul(chars: &[u8]) -> Result<&Self, FromSliceWithNulError> {
let nul_pos = chars.iter().position(|&c| c == 0);
if let Some(nul_pos) = nul_pos {
if nul_pos + 1 != chars.len() {
return Err(FromSliceWithNulError::InteriorNul(nul_pos));
}
Ok(unsafe { Self::from_bytes_with_nul_unchecked(chars) })
} else {
Err(FromSliceWithNulError::NotNulTerminated)
}
}
/// Unsafely creates a CStr8 reference from bytes.
///
/// # Safety
///
/// It's the callers responsibility to ensure chars is a valid Latin-1
/// null-terminated string, with no interior null bytes.
#[must_use]
pub const unsafe fn from_bytes_with_nul_unchecked(chars: &[u8]) -> &Self {
&*(chars as *const [u8] as *const Self)
}
/// Returns the inner pointer to this CStr8.
#[must_use]
pub const fn as_ptr(&self) -> *const Char8 {
self.0.as_ptr()
}
/// Returns the underlying bytes as slice including the terminating null
/// character.
#[must_use]
pub const fn as_bytes(&self) -> &[u8] {
unsafe { &*(&self.0 as *const [Char8] as *const [u8]) }
}
}
impl fmt::Debug for CStr8 {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
write!(f, "CStr8({:?})", &self.0)
}
}
impl fmt::Display for CStr8 {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
for c in self.0.iter() {
<Char8 as fmt::Display>::fmt(c, f)?;
}
Ok(())
}
}
impl AsRef<[u8]> for CStr8 {
fn as_ref(&self) -> &[u8] {
self.as_bytes()
}
}
impl Borrow<[u8]> for CStr8 {
fn borrow(&self) -> &[u8] {
self.as_bytes()
}
}
impl<StrType: AsRef<str> + ?Sized> EqStrUntilNul<StrType> for CStr8 {
fn eq_str_until_nul(&self, other: &StrType) -> bool {
let other = other.as_ref();
// TODO: CStr16 has .iter() implemented, CStr8 not yet
let any_not_equal = self
.0
.iter()
.copied()
.map(char::from)
.zip(other.chars())
// This only works as CStr8 is guaranteed to have a fixed character length
// (unlike UTF-8).
.take_while(|(l, r)| *l != '\0' && *r != '\0')
.any(|(l, r)| l != r);
!any_not_equal
}
}
impl<'a> TryFrom<&'a CStr> for &'a CStr8 {
type Error = FromSliceWithNulError;
fn try_from(cstr: &'a CStr) -> Result<Self, Self::Error> {
CStr8::from_bytes_with_nul(cstr.to_bytes_with_nul())
}
}
/// Get a Latin-1 character from a UTF-8 byte slice at the given offset.
///
/// Returns a pair containing the Latin-1 character and the number of bytes in
/// the UTF-8 encoding of that character.
///
/// Panics if the string cannot be encoded in Latin-1.
///
/// # Safety
///
/// The input `bytes` must be valid UTF-8.
const unsafe fn latin1_from_utf8_at_offset(bytes: &[u8], offset: usize) -> (u8, usize) {
if bytes[offset] & 0b1000_0000 == 0b0000_0000 {
(bytes[offset], 1)
} else if bytes[offset] & 0b1110_0000 == 0b1100_0000 {
let a = (bytes[offset] & 0b0001_1111) as u16;
let b = (bytes[offset + 1] & 0b0011_1111) as u16;
let ch = a << 6 | b;
if ch > 0xff {
panic!("input string cannot be encoded as Latin-1");
}
(ch as u8, 2)
} else {
// Latin-1 code points only go up to 0xff, so if the input contains any
// UTF-8 characters larger than two bytes it cannot be converted to
// Latin-1.
panic!("input string cannot be encoded as Latin-1");
}
}
/// Count the number of Latin-1 characters in a string.
///
/// Panics if the string cannot be encoded in Latin-1.
///
/// This is public but hidden; it is used in the `cstr8` macro.
#[must_use]
pub const fn str_num_latin1_chars(s: &str) -> usize {
let bytes = s.as_bytes();
let len = bytes.len();
let mut offset = 0;
let mut num_latin1_chars = 0;
while offset < len {
// SAFETY: `bytes` is valid UTF-8.
let (_, num_utf8_bytes) = unsafe { latin1_from_utf8_at_offset(bytes, offset) };
offset += num_utf8_bytes;
num_latin1_chars += 1;
}
num_latin1_chars
}
/// Convert a `str` into a null-terminated Latin-1 character array.
///
/// Panics if the string cannot be encoded in Latin-1.
///
/// This is public but hidden; it is used in the `cstr8` macro.
#[must_use]
pub const fn str_to_latin1<const N: usize>(s: &str) -> [u8; N] {
let bytes = s.as_bytes();
let len = bytes.len();
let mut output = [0; N];
let mut output_offset = 0;
let mut input_offset = 0;
while input_offset < len {
// SAFETY: `bytes` is valid UTF-8.
let (ch, num_utf8_bytes) = unsafe { latin1_from_utf8_at_offset(bytes, input_offset) };
if ch == 0 {
panic!("interior null character");
} else {
output[output_offset] = ch;
output_offset += 1;
input_offset += num_utf8_bytes;
}
}
// The output array must be one bigger than the converted string,
// to leave room for the trailing null character.
if output_offset + 1 != N {
panic!("incorrect array length");
}
output
}
/// An UCS-2 null-terminated string slice.
///
/// This type is largely inspired by [`core::ffi::CStr`] with the exception that all characters are
/// guaranteed to be 16 bit long.
///
/// For convenience, a [`CStr16`] is comparable with [`core::str`] and
/// `alloc::string::String` from the standard library through the trait [`EqStrUntilNul`].
#[derive(Eq, PartialEq, Ord, PartialOrd, Hash)]
#[repr(transparent)]
pub struct CStr16([Char16]);
impl CStr16 {
/// Wraps a raw UEFI string with a safe C string wrapper
///
/// # Safety
///
/// The function will start accessing memory from `ptr` until the first
/// null character. It's the callers responsibility to ensure `ptr` points to
/// a valid string, in accessible memory.
#[must_use]
pub unsafe fn from_ptr<'ptr>(ptr: *const Char16) -> &'ptr Self {
let mut len = 0;
while *ptr.add(len) != NUL_16 {
len += 1
}
let ptr = ptr.cast::<u16>();
Self::from_u16_with_nul_unchecked(slice::from_raw_parts(ptr, len + 1))
}
/// Creates a `&CStr16` from a u16 slice, if the slice contains exactly
/// one terminating null-byte and all chars are valid UCS-2 chars.
pub fn from_u16_with_nul(codes: &[u16]) -> Result<&Self, FromSliceWithNulError> {
for (pos, &code) in codes.iter().enumerate() {
match code.try_into() {
Ok(NUL_16) => {
if pos != codes.len() - 1 {
return Err(FromSliceWithNulError::InteriorNul(pos));
} else {
return Ok(unsafe { Self::from_u16_with_nul_unchecked(codes) });
}
}
Err(_) => {
return Err(FromSliceWithNulError::InvalidChar(pos));
}
_ => {}
}
}
Err(FromSliceWithNulError::NotNulTerminated)
}
/// Unsafely creates a `&CStr16` from a u16 slice.
///
/// # Safety
///
/// It's the callers responsibility to ensure chars is a valid UCS-2
/// null-terminated string, with no interior null characters.
#[must_use]
pub const unsafe fn from_u16_with_nul_unchecked(codes: &[u16]) -> &Self {
&*(codes as *const [u16] as *const Self)
}
/// Creates a `&CStr16` from a [`Char16`] slice, if the slice is
/// null-terminated and has no interior null characters.
pub fn from_char16_with_nul(chars: &[Char16]) -> Result<&Self, FromSliceWithNulError> {
// Fail early if the input is empty.
if chars.is_empty() {
return Err(FromSliceWithNulError::NotNulTerminated);
}
// Find the index of the first null char.
if let Some(null_index) = chars.iter().position(|c| *c == NUL_16) {
// Verify the null character is at the end.
if null_index == chars.len() - 1 {
// Safety: the input is null-terminated and has no interior nulls.
Ok(unsafe { Self::from_char16_with_nul_unchecked(chars) })
} else {
Err(FromSliceWithNulError::InteriorNul(null_index))
}
} else {
Err(FromSliceWithNulError::NotNulTerminated)
}
}
/// Unsafely creates a `&CStr16` from a `Char16` slice.
///
/// # Safety
///
/// It's the callers responsibility to ensure chars is null-terminated and
/// has no interior null characters.
#[must_use]
pub const unsafe fn from_char16_with_nul_unchecked(chars: &[Char16]) -> &Self {
let ptr: *const [Char16] = chars;
&*(ptr as *const Self)
}
/// Convert a [`&str`] to a `&CStr16`, backed by a buffer.
///
/// The input string must contain only characters representable with
/// UCS-2, and must not contain any null characters (even at the end of
/// the input).
///
/// The backing buffer must be big enough to hold the converted string as
/// well as a trailing null character.
///
/// # Examples
///
/// Convert the UTF-8 string "ABC" to a `&CStr16`:
///
/// ```
/// use uefi::CStr16;
///
/// let mut buf = [0; 4];
/// CStr16::from_str_with_buf("ABC", &mut buf).unwrap();
/// ```
pub fn from_str_with_buf<'a>(
input: &str,
buf: &'a mut [u16],
) -> Result<&'a Self, FromStrWithBufError> {
let mut index = 0;
// Convert to UTF-16.
for c in input.encode_utf16() {
*buf.get_mut(index)
.ok_or(FromStrWithBufError::BufferTooSmall)? = c;
index += 1;
}
// Add trailing null character.
*buf.get_mut(index)
.ok_or(FromStrWithBufError::BufferTooSmall)? = 0;
// Convert from u16 to Char16. This checks for invalid UCS-2 chars and
// interior nulls. The NotNulTerminated case is unreachable because we
// just added a trailing null character.
Self::from_u16_with_nul(&buf[..index + 1]).map_err(|err| match err {
FromSliceWithNulError::InvalidChar(p) => FromStrWithBufError::InvalidChar(p),
FromSliceWithNulError::InteriorNul(p) => FromStrWithBufError::InteriorNul(p),
FromSliceWithNulError::NotNulTerminated => {
unreachable!()
}
})
}
/// Create a `&CStr16` from an [`UnalignedSlice`] using an aligned
/// buffer for storage. The lifetime of the output is tied to `buf`,
/// not `src`.
pub fn from_unaligned_slice<'buf>(
src: &UnalignedSlice<'_, u16>,
buf: &'buf mut [MaybeUninit<u16>],
) -> Result<&'buf Self, UnalignedCStr16Error> {
// The input `buf` might be longer than needed, so get a
// subslice of the required length.
let buf = buf
.get_mut(..src.len())
.ok_or(UnalignedCStr16Error::BufferTooSmall)?;
src.copy_to_maybe_uninit(buf);
let buf = unsafe {
// Safety: `copy_buf` fully initializes the slice.
maybe_uninit_slice_assume_init_ref(buf)
};
Self::from_u16_with_nul(buf).map_err(|e| match e {
FromSliceWithNulError::InvalidChar(v) => UnalignedCStr16Error::InvalidChar(v),
FromSliceWithNulError::InteriorNul(v) => UnalignedCStr16Error::InteriorNul(v),
FromSliceWithNulError::NotNulTerminated => UnalignedCStr16Error::NotNulTerminated,
})
}
/// Returns the inner pointer to this C16 string.
#[must_use]
pub const fn as_ptr(&self) -> *const Char16 {
self.0.as_ptr()
}
/// Get the underlying [`Char16`]s as slice without the trailing null.
#[must_use]
pub fn as_slice(&self) -> &[Char16] {
&self.0[..self.num_chars()]
}
/// Get the underlying [`Char16`]s as slice including the trailing null.
#[must_use]
pub const fn as_slice_with_nul(&self) -> &[Char16] {
&self.0
}
/// Converts this C string to a u16 slice without the trailing null.
#[must_use]
pub fn to_u16_slice(&self) -> &[u16] {
let chars = self.to_u16_slice_with_nul();
&chars[..chars.len() - 1]
}
/// Converts this C string to a u16 slice containing the trailing null.
#[must_use]
pub const fn to_u16_slice_with_nul(&self) -> &[u16] {
unsafe { &*(&self.0 as *const [Char16] as *const [u16]) }
}
/// Returns an iterator over this C string
#[must_use]
pub const fn iter(&self) -> CStr16Iter {
CStr16Iter {
inner: self,
pos: 0,
}
}
/// Returns the number of characters without the trailing null. character
#[must_use]
pub const fn num_chars(&self) -> usize {
self.0.len() - 1
}
/// Returns if the string is empty. This ignores the null character.
#[must_use]
pub const fn is_empty(&self) -> bool {
self.num_chars() == 0
}
/// Get the number of bytes in the string (including the trailing null).
#[must_use]
pub const fn num_bytes(&self) -> usize {
self.0.len() * 2
}
/// Checks if all characters in this string are within the ASCII range.
#[must_use]
pub fn is_ascii(&self) -> bool {
self.0.iter().all(|c| c.is_ascii())
}
/// Writes each [`Char16`] as a [`char`] (4 bytes long in Rust language) into the buffer.
/// It is up to the implementer of [`core::fmt::Write`] to convert the char to a string
/// with proper encoding/charset. For example, in the case of [`alloc::string::String`]
/// all Rust chars (UTF-32) get converted to UTF-8.
///
/// ## Example
///
/// ```ignore
/// let firmware_vendor_c16_str: CStr16 = ...;
/// // crate "arrayvec" uses stack-allocated arrays for Strings => no heap allocations
/// let mut buf = arrayvec::ArrayString::<128>::new();
/// firmware_vendor_c16_str.as_str_in_buf(&mut buf);
/// log::info!("as rust str: {}", buf.as_str());
/// ```
///
/// [`alloc::string::String`]: https://doc.rust-lang.org/nightly/alloc/string/struct.String.html
pub fn as_str_in_buf(&self, buf: &mut dyn core::fmt::Write) -> core::fmt::Result {
for c16 in self.iter() {
buf.write_char(char::from(*c16))?;
}
Ok(())
}
/// Returns the underlying bytes as slice including the terminating null
/// character.
#[must_use]
pub const fn as_bytes(&self) -> &[u8] {
unsafe { slice::from_raw_parts(self.0.as_ptr().cast(), self.num_bytes()) }
}
}
impl AsRef<[u8]> for CStr16 {
fn as_ref(&self) -> &[u8] {
self.as_bytes()
}
}
impl Borrow<[u8]> for CStr16 {
fn borrow(&self) -> &[u8] {
self.as_bytes()
}
}
#[cfg(feature = "alloc")]
impl From<&CStr16> for alloc::string::String {
fn from(value: &CStr16) -> Self {
value
.as_slice()
.iter()
.copied()
.map(u16::from)
.map(u32::from)
.map(|int| char::from_u32(int).expect("Should be encodable as UTF-8"))
.collect::<Self>()
}
}
impl<StrType: AsRef<str> + ?Sized> EqStrUntilNul<StrType> for CStr16 {
fn eq_str_until_nul(&self, other: &StrType) -> bool {
let other = other.as_ref();
let any_not_equal = self
.iter()
.copied()
.map(char::from)
.zip(other.chars())
// This only works as CStr16 is guaranteed to have a fixed character length
// (unlike UTF-8 or UTF-16).
.take_while(|(l, r)| *l != '\0' && *r != '\0')
.any(|(l, r)| l != r);
!any_not_equal
}
}
impl AsRef<Self> for CStr16 {
fn as_ref(&self) -> &Self {
self
}
}
/// An iterator over the [`Char16`]s in a [`CStr16`].
#[derive(Debug)]
pub struct CStr16Iter<'a> {
inner: &'a CStr16,
pos: usize,
}
impl<'a> Iterator for CStr16Iter<'a> {
type Item = &'a Char16;
fn next(&mut self) -> Option<Self::Item> {
if self.pos >= self.inner.0.len() - 1 {
None
} else {
self.pos += 1;
self.inner.0.get(self.pos - 1)
}
}
}
impl fmt::Debug for CStr16 {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
write!(f, "CStr16({:?})", &self.0)
}
}
impl fmt::Display for CStr16 {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
for c in self.iter() {
<Char16 as fmt::Display>::fmt(c, f)?;
}
Ok(())
}
}
#[cfg(feature = "alloc")]
impl PartialEq<CString16> for &CStr16 {
fn eq(&self, other: &CString16) -> bool {
PartialEq::eq(*self, other.as_ref())
}
}
impl<'a> UnalignedSlice<'a, u16> {
/// Create a [`CStr16`] from an [`UnalignedSlice`] using an aligned
/// buffer for storage. The lifetime of the output is tied to `buf`,
/// not `self`.
pub fn to_cstr16<'buf>(
&self,
buf: &'buf mut [MaybeUninit<u16>],
) -> Result<&'buf CStr16, UnalignedCStr16Error> {
CStr16::from_unaligned_slice(self, buf)
}
}
/// The EqStrUntilNul trait helps to compare Rust strings against UEFI string types (UCS-2 strings).
/// The given generic implementation of this trait enables us that we only have to
/// implement one direction (`left.eq_str_until_nul(&right)`) for each UEFI string type and we
/// get the other direction (`right.eq_str_until_nul(&left)`) for free. Hence, the relation is
/// reflexive.
pub trait EqStrUntilNul<StrType: ?Sized> {
/// Checks if the provided Rust string `StrType` is equal to [Self] until the first null character
/// is found. An exception is the terminating null character of [Self] which is ignored.
///
/// As soon as the first null character in either `&self` or `other` is found, this method returns.
/// Note that Rust strings are allowed to contain null bytes that do not terminate the string.
/// Although this is rather unusual, you can compare `"foo\0bar"` with an instance of [Self].
/// In that case, only `foo"` is compared against [Self] (if [Self] is long enough).
fn eq_str_until_nul(&self, other: &StrType) -> bool;
}
// magic implementation which transforms an existing `left.eq_str_until_nul(&right)` implementation
// into an additional working `right.eq_str_until_nul(&left)` implementation.
impl<StrType, C16StrType> EqStrUntilNul<C16StrType> for StrType
where
StrType: AsRef<str>,
C16StrType: EqStrUntilNul<StrType> + ?Sized,
{
fn eq_str_until_nul(&self, other: &C16StrType) -> bool {
// reuse the existing implementation
other.eq_str_until_nul(self)
}
}
#[cfg(test)]
mod tests {
use super::*;
use crate::{cstr16, cstr8};
use alloc::string::String;
// Tests if our CStr8 type can be constructed from a valid core::ffi::CStr
#[test]
fn test_cstr8_from_cstr() {
let msg = "hello world\0";
let cstr = unsafe { CStr::from_ptr(msg.as_ptr().cast()) };
let cstr8: &CStr8 = TryFrom::try_from(cstr).unwrap();
assert!(cstr8.eq_str_until_nul(msg));
assert!(msg.eq_str_until_nul(cstr8));
}
#[test]
fn test_cstr8_as_bytes() {
let string: &CStr8 = cstr8!("a");
assert_eq!(string.as_bytes(), &[b'a', 0]);
assert_eq!(<CStr8 as AsRef<[u8]>>::as_ref(string), &[b'a', 0]);
assert_eq!(<CStr8 as Borrow<[u8]>>::borrow(string), &[b'a', 0]);
}
#[test]
fn test_cstr16_num_bytes() {
let s = CStr16::from_u16_with_nul(&[65, 66, 67, 0]).unwrap();
assert_eq!(s.num_bytes(), 8);
}
#[test]
fn test_cstr16_from_char16_with_nul() {
// Invalid: empty input.
assert_eq!(
CStr16::from_char16_with_nul(&[]),
Err(FromSliceWithNulError::NotNulTerminated)
);
// Invalid: interior null.
assert_eq!(
CStr16::from_char16_with_nul(&[
Char16::try_from('a').unwrap(),
NUL_16,
Char16::try_from('b').unwrap(),
NUL_16
]),
Err(FromSliceWithNulError::InteriorNul(1))
);
// Invalid: no trailing null.
assert_eq!(
CStr16::from_char16_with_nul(&[
Char16::try_from('a').unwrap(),
Char16::try_from('b').unwrap(),
]),
Err(FromSliceWithNulError::NotNulTerminated)
);
// Valid.
assert_eq!(
CStr16::from_char16_with_nul(&[
Char16::try_from('a').unwrap(),
Char16::try_from('b').unwrap(),
NUL_16,
]),
Ok(cstr16!("ab"))
);
}
#[test]
fn test_cstr16_from_str_with_buf() {
let mut buf = [0; 4];
// OK: buf is exactly the right size.
let s = CStr16::from_str_with_buf("ABC", &mut buf).unwrap();
assert_eq!(s.to_u16_slice_with_nul(), [65, 66, 67, 0]);
// OK: buf is bigger than needed.
let s = CStr16::from_str_with_buf("A", &mut buf).unwrap();
assert_eq!(s.to_u16_slice_with_nul(), [65, 0]);
// Error: buf is too small.
assert_eq!(
CStr16::from_str_with_buf("ABCD", &mut buf).unwrap_err(),
FromStrWithBufError::BufferTooSmall
);
// Error: invalid character.
assert_eq!(
CStr16::from_str_with_buf("a😀", &mut buf).unwrap_err(),
FromStrWithBufError::InvalidChar(1),
);
// Error: interior null.
assert_eq!(
CStr16::from_str_with_buf("a\0b", &mut buf).unwrap_err(),
FromStrWithBufError::InteriorNul(1),
);
}
#[test]
fn test_cstr16_macro() {
// Just a sanity check to make sure it's spitting out the right characters
assert_eq!(
crate::prelude::cstr16!("ABC").to_u16_slice_with_nul(),
[65, 66, 67, 0]
)
}
#[test]
fn test_unaligned_cstr16() {
let mut buf = [0u16; 6];
let us = unsafe {
let ptr = buf.as_mut_ptr() as *mut u8;
// Intentionally create an unaligned u16 pointer. This
// leaves room for five u16 characters.
let ptr = ptr.add(1) as *mut u16;
// Write out the "test" string.
ptr.add(0).write_unaligned(b't'.into());
ptr.add(1).write_unaligned(b'e'.into());
ptr.add(2).write_unaligned(b's'.into());
ptr.add(3).write_unaligned(b't'.into());
ptr.add(4).write_unaligned(b'\0'.into());
// Create the `UnalignedSlice`.
UnalignedSlice::new(ptr, 5)
};
// Test `to_cstr16()` with too small of a buffer.
let mut buf = [MaybeUninit::new(0); 4];
assert_eq!(
us.to_cstr16(&mut buf).unwrap_err(),
UnalignedCStr16Error::BufferTooSmall
);
// Test with a big enough buffer.
let mut buf = [MaybeUninit::new(0); 5];
assert_eq!(
us.to_cstr16(&mut buf).unwrap(),
CString16::try_from("test").unwrap()
);
// Test `to_cstring16()`.
assert_eq!(
us.to_cstring16().unwrap(),
CString16::try_from("test").unwrap()
);
}
#[test]
fn test_cstr16_as_slice() {
let string: &CStr16 = cstr16!("a");
assert_eq!(string.as_slice(), &[Char16::try_from('a').unwrap()]);
assert_eq!(
string.as_slice_with_nul(),
&[Char16::try_from('a').unwrap(), NUL_16]
);
}
#[test]
fn test_cstr16_as_bytes() {
let string: &CStr16 = cstr16!("a");
assert_eq!(string.as_bytes(), &[b'a', 0, 0, 0]);
assert_eq!(<CStr16 as AsRef<[u8]>>::as_ref(string), &[b'a', 0, 0, 0]);
assert_eq!(<CStr16 as Borrow<[u8]>>::borrow(string), &[b'a', 0, 0, 0]);
}
// Code generation helper for the compare tests of our CStrX types against "str" and "String"
// from the standard library.
#[allow(non_snake_case)]
macro_rules! test_compare_cstrX {
($input:ident) => {
assert!($input.eq_str_until_nul(&"test"));
assert!($input.eq_str_until_nul(&String::from("test")));
// now other direction
assert!(String::from("test").eq_str_until_nul($input));
assert!("test".eq_str_until_nul($input));
// some more tests
// this is fine: compare until the first null
assert!($input.eq_str_until_nul(&"te\0st"));
// this is fine
assert!($input.eq_str_until_nul(&"test\0"));
assert!(!$input.eq_str_until_nul(&"hello"));
};
}
#[test]
fn test_compare_cstr8() {
// test various comparisons with different order (left, right)
let input: &CStr8 = cstr8!("test");
test_compare_cstrX!(input);
}
#[test]
fn test_compare_cstr16() {
let input: &CStr16 = cstr16!("test");
test_compare_cstrX!(input);
}
/// Test that the `cstr16!` macro can be used in a `const` context.
#[test]
fn test_cstr16_macro_const() {
const S: &CStr16 = cstr16!("ABC");
assert_eq!(S.to_u16_slice_with_nul(), [65, 66, 67, 0]);
}
/// Tests the trait implementation of trait [`EqStrUntilNul]` for [`CStr8`].
///
/// This tests that `String` and `str` from the standard library can be
/// checked for equality against a [`CStr8`]. It checks both directions,
/// i.e., the equality is reflexive.
#[test]
fn test_cstr8_eq_std_str() {
let input: &CStr8 = cstr8!("test");
// test various comparisons with different order (left, right)
assert!(input.eq_str_until_nul("test")); // requires ?Sized constraint
assert!(input.eq_str_until_nul(&"test"));
assert!(input.eq_str_until_nul(&String::from("test")));
// now other direction
assert!(String::from("test").eq_str_until_nul(input));
assert!("test".eq_str_until_nul(input));
}
/// Tests the trait implementation of trait [`EqStrUntilNul]` for [`CStr16`].
///
/// This tests that `String` and `str` from the standard library can be
/// checked for equality against a [`CStr16`]. It checks both directions,
/// i.e., the equality is reflexive.
#[test]
fn test_cstr16_eq_std_str() {
let input: &CStr16 = cstr16!("test");
assert!(input.eq_str_until_nul("test")); // requires ?Sized constraint
assert!(input.eq_str_until_nul(&"test"));
assert!(input.eq_str_until_nul(&String::from("test")));
// now other direction
assert!(String::from("test").eq_str_until_nul(input));
assert!("test".eq_str_until_nul(input));
}
}