| // Copyright (C) 2017-2018 Baidu, Inc. All Rights Reserved. |
| // |
| // Redistribution and use in source and binary forms, with or without |
| // modification, are permitted provided that the following conditions |
| // are met: |
| // |
| // * Redistributions of source code must retain the above copyright |
| // notice, this list of conditions and the following disclaimer. |
| // * Redistributions in binary form must reproduce the above copyright |
| // notice, this list of conditions and the following disclaimer in |
| // the documentation and/or other materials provided with the |
| // distribution. |
| // * Neither the name of Baidu, Inc., nor the names of its |
| // contributors may be used to endorse or promote products derived |
| // from this software without specific prior written permission. |
| // |
| // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| |
| /// A type representing an owned, C-compatible, nul-terminated string with no nul bytes in the |
| /// middle. |
| /// |
| /// This type serves the purpose of being able to safely generate a |
| /// C-compatible string from a Rust byte slice or vector. An instance of this |
| /// type is a static guarantee that the underlying bytes contain no interior 0 |
| /// bytes ("nul characters") and that the final byte is 0 ("nul terminator"). |
| /// |
| use sgx_types::c_char; |
| use libc; |
| use memchr; |
| use ascii; |
| //use error::Error; |
| //use io; |
| |
| use core::ops; |
| use core::cmp::Ordering; |
| use core::mem; |
| use core::ptr; |
| use core::fmt::{self, Write}; |
| use alloc::boxed::Box; |
| use alloc::borrow::{Cow, Borrow, ToOwned}; |
| use alloc::vec::Vec; |
| use alloc::string::String; |
| use alloc::slice; |
| use alloc::rc::Rc; |
| use alloc::arc::Arc; |
| |
| use alloc::str::{self, Utf8Error}; |
| |
| /// A type representing an owned C-compatible string |
| /// |
| #[derive(PartialEq, PartialOrd, Eq, Ord, Hash, Clone)] |
| pub struct CString { |
| inner: Box<[u8]>, |
| } |
| |
| /// Representation of a borrowed C string. |
| /// |
| #[derive(Hash)] |
| pub struct CStr { |
| inner: [c_char] |
| } |
| |
| /// An error returned from `CString::new` to indicate that a nul byte was found |
| /// in the vector provided. |
| #[derive(Clone, PartialEq, Eq, Debug)] |
| pub struct NulError(usize, Vec<u8>); |
| |
| /// An error returned from `CStr::from_bytes_with_nul` to indicate that a nul |
| /// byte was found too early in the slice provided or one wasn't found at all. |
| #[derive(Clone, PartialEq, Eq, Debug)] |
| pub struct FromBytesWithNulError { |
| kind: FromBytesWithNulErrorKind, |
| } |
| |
| #[derive(Clone, PartialEq, Eq, Debug)] |
| enum FromBytesWithNulErrorKind { |
| InteriorNul(usize), |
| NotNulTerminated, |
| } |
| |
| impl FromBytesWithNulError { |
| fn interior_nul(pos: usize) -> FromBytesWithNulError { |
| FromBytesWithNulError { |
| kind: FromBytesWithNulErrorKind::InteriorNul(pos), |
| } |
| } |
| fn not_nul_terminated() -> FromBytesWithNulError { |
| FromBytesWithNulError { |
| kind: FromBytesWithNulErrorKind::NotNulTerminated, |
| } |
| } |
| |
| pub fn __description(&self) -> &str { |
| match self.kind { |
| FromBytesWithNulErrorKind::InteriorNul(..) => |
| "data provided contains an interior nul byte", |
| FromBytesWithNulErrorKind::NotNulTerminated => |
| "data provided is not nul terminated", |
| } |
| } |
| } |
| |
| /// An error returned from `CString::into_string` to indicate that a UTF-8 error |
| /// was encountered during the conversion. |
| #[derive(Clone, PartialEq, Eq, Debug)] |
| pub struct IntoStringError { |
| inner: CString, |
| error: Utf8Error, |
| } |
| |
| impl CString { |
| /// Creates a new C-compatible string from a container of bytes. |
| /// |
| /// This method will consume the provided data and use the underlying bytes |
| /// to construct a new string, ensuring that there is a trailing 0 byte. |
| /// |
| /// # Errors |
| /// |
| /// This function will return an error if the bytes yielded contain an |
| /// internal 0 byte. The error returned will contain the bytes as well as |
| /// the position of the nul byte. |
| pub fn new<T: Into<Vec<u8>>>(t: T) -> Result<CString, NulError> { |
| Self::_new(t.into()) |
| } |
| |
| fn _new(bytes: Vec<u8>) -> Result<CString, NulError> { |
| match memchr::memchr(0, &bytes) { |
| Some(i) => Err(NulError(i, bytes)), |
| None => Ok(unsafe { CString::from_vec_unchecked(bytes) }), |
| } |
| } |
| |
| /// Creates a C-compatible string from a byte vector without checking for |
| /// interior 0 bytes. |
| /// |
| /// This method is equivalent to `new` except that no runtime assertion |
| /// is made that `v` contains no 0 bytes, and it requires an actual |
| /// byte vector, not anything that can be converted to one with Into. |
| /// |
| pub unsafe fn from_vec_unchecked(mut v: Vec<u8>) -> CString { |
| v.reserve_exact(1); |
| v.push(0); |
| CString { inner: v.into_boxed_slice() } |
| } |
| |
| /// Retakes ownership of a `CString` that was transferred to C. |
| /// |
| /// Additionally, the length of the string will be recalculated from the pointer. |
| /// |
| /// # Safety |
| /// |
| /// This should only ever be called with a pointer that was earlier |
| /// obtained by calling `into_raw` on a `CString`. Other usage (e.g. trying to take |
| /// ownership of a string that was allocated by foreign code) is likely to lead |
| /// to undefined behavior or allocator corruption. |
| pub unsafe fn from_raw(ptr: *mut c_char) -> CString { |
| let len = libc::strlen(ptr) + 1; // Including the NUL byte |
| let slice = slice::from_raw_parts_mut(ptr, len as usize); |
| CString { inner: Box::from_raw(slice as *mut [c_char] as *mut [u8]) } |
| } |
| |
| /// Transfers ownership of the string to a C caller. |
| /// |
| /// The pointer must be returned to Rust and reconstituted using |
| /// `from_raw` to be properly deallocated. Specifically, one |
| /// should *not* use the standard C `free` function to deallocate |
| /// this string. |
| /// |
| /// Failure to call `from_raw` will lead to a memory leak. |
| pub fn into_raw(self) -> *mut c_char { |
| Box::into_raw(self.into_inner()) as *mut c_char |
| } |
| |
| /// Converts the `CString` into a `String` if it contains valid Unicode data. |
| /// |
| /// On failure, ownership of the original `CString` is returned. |
| pub fn into_string(self) -> Result<String, IntoStringError> { |
| String::from_utf8(self.into_bytes()) |
| .map_err(|e| IntoStringError { |
| error: e.utf8_error(), |
| inner: unsafe { CString::from_vec_unchecked(e.into_bytes()) }, |
| }) |
| } |
| |
| /// Returns the underlying byte buffer. |
| /// |
| /// The returned buffer does **not** contain the trailing nul separator and |
| /// it is guaranteed to not have any interior nul bytes. |
| pub fn into_bytes(self) -> Vec<u8> { |
| let mut vec = self.into_inner().into_vec(); |
| let _nul = vec.pop(); |
| debug_assert_eq!(_nul, Some(0u8)); |
| vec |
| } |
| |
| /// Equivalent to the `into_bytes` function except that the returned vector |
| /// includes the trailing nul byte. |
| pub fn into_bytes_with_nul(self) -> Vec<u8> { |
| self.into_inner().into_vec() |
| } |
| |
| /// Returns the contents of this `CString` as a slice of bytes. |
| /// |
| /// The returned slice does **not** contain the trailing nul separator and |
| /// it is guaranteed to not have any interior nul bytes. |
| pub fn as_bytes(&self) -> &[u8] { |
| &self.inner[..self.inner.len() - 1] |
| } |
| |
| /// Equivalent to the `as_bytes` function except that the returned slice |
| /// includes the trailing nul byte. |
| pub fn as_bytes_with_nul(&self) -> &[u8] { |
| &self.inner |
| } |
| |
| /// Extracts a `CStr` slice containing the entire string. |
| pub fn as_c_str(&self) -> &CStr { |
| &*self |
| } |
| |
| /// Converts this `CString` into a boxed `CStr`. |
| pub fn into_boxed_c_str(self) -> Box<CStr> { |
| unsafe { Box::from_raw(Box::into_raw(self.into_inner()) as *mut CStr) } |
| } |
| |
| // Bypass "move out of struct which implements `Drop` trait" restriction. |
| fn into_inner(self) -> Box<[u8]> { |
| unsafe { |
| let result = ptr::read(&self.inner); |
| mem::forget(self); |
| result |
| } |
| } |
| } |
| |
| // Turns this `CString` into an empty string to prevent |
| // memory unsafe code from working by accident. Inline |
| // to prevent LLVM from optimizing it away in debug builds. |
| impl Drop for CString { |
| #[inline] |
| fn drop(&mut self) { |
| unsafe { *self.inner.get_unchecked_mut(0) = 0; } |
| } |
| } |
| |
| impl ops::Deref for CString { |
| type Target = CStr; |
| |
| #[inline] |
| fn deref(&self) -> &CStr { |
| unsafe { CStr::from_bytes_with_nul_unchecked(self.as_bytes_with_nul()) } |
| } |
| } |
| |
| impl fmt::Debug for CString { |
| fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { |
| fmt::Debug::fmt(&**self, f) |
| } |
| } |
| |
| impl From<CString> for Vec<u8> { |
| #[inline] |
| fn from(s: CString) -> Vec<u8> { |
| s.into_bytes() |
| } |
| } |
| |
| impl fmt::Debug for CStr { |
| fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { |
| write!(f, "\"")?; |
| for byte in self.to_bytes().iter().flat_map(|&b| ascii::escape_default(b)) { |
| f.write_char(byte as char)?; |
| } |
| write!(f, "\"") |
| } |
| } |
| |
| impl<'a> Default for &'a CStr { |
| fn default() -> &'a CStr { |
| const SLICE: &'static [c_char] = &[0]; |
| unsafe { CStr::from_ptr(SLICE.as_ptr()) } |
| } |
| } |
| |
| impl Default for CString { |
| /// Creates an empty `CString`. |
| fn default() -> CString { |
| let a: &CStr = Default::default(); |
| a.to_owned() |
| } |
| } |
| |
| impl Borrow<CStr> for CString { |
| #[inline] |
| fn borrow(&self) -> &CStr { self } |
| } |
| |
| impl<'a> From<&'a CStr> for Box<CStr> { |
| fn from(s: &'a CStr) -> Box<CStr> { |
| let boxed: Box<[u8]> = Box::from(s.to_bytes_with_nul()); |
| unsafe { Box::from_raw(Box::into_raw(boxed) as *mut CStr) } |
| } |
| } |
| |
| impl From<Box<CStr>> for CString { |
| #[inline] |
| fn from(s: Box<CStr>) -> CString { |
| s.into_c_string() |
| } |
| } |
| |
| impl From<CString> for Box<CStr> { |
| #[inline] |
| fn from(s: CString) -> Box<CStr> { |
| s.into_boxed_c_str() |
| } |
| } |
| |
| impl From<CString> for Arc<CStr> { |
| #[inline] |
| fn from(s: CString) -> Arc<CStr> { |
| let arc: Arc<[u8]> = Arc::from(s.into_inner()); |
| unsafe { Arc::from_raw(Arc::into_raw(arc) as *const CStr) } |
| } |
| } |
| |
| impl<'a> From<&'a CStr> for Arc<CStr> { |
| #[inline] |
| fn from(s: &CStr) -> Arc<CStr> { |
| let arc: Arc<[u8]> = Arc::from(s.to_bytes_with_nul()); |
| unsafe { Arc::from_raw(Arc::into_raw(arc) as *const CStr) } |
| } |
| } |
| |
| impl From<CString> for Rc<CStr> { |
| #[inline] |
| fn from(s: CString) -> Rc<CStr> { |
| let rc: Rc<[u8]> = Rc::from(s.into_inner()); |
| unsafe { Rc::from_raw(Rc::into_raw(rc) as *const CStr) } |
| } |
| } |
| |
| impl<'a> From<&'a CStr> for Rc<CStr> { |
| #[inline] |
| fn from(s: &CStr) -> Rc<CStr> { |
| let rc: Rc<[u8]> = Rc::from(s.to_bytes_with_nul()); |
| unsafe { Rc::from_raw(Rc::into_raw(rc) as *const CStr) } |
| } |
| } |
| |
| impl Default for Box<CStr> { |
| fn default() -> Box<CStr> { |
| let boxed: Box<[u8]> = Box::from([0]); |
| unsafe { Box::from_raw(Box::into_raw(boxed) as *mut CStr) } |
| } |
| } |
| |
| impl NulError { |
| /// Returns the position of the nul byte in the slice that was provided to |
| /// `CString::new`. |
| /// |
| pub fn nul_position(&self) -> usize { self.0 } |
| |
| /// Consumes this error, returning the underlying vector of bytes which |
| /// generated the error in the first place. |
| /// |
| pub fn into_vec(self) -> Vec<u8> { self.1 } |
| } |
| |
| impl fmt::Display for NulError { |
| fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { |
| write!(f, "nul byte found in provided data at position: {}", self.0) |
| } |
| } |
| |
| impl fmt::Display for FromBytesWithNulError { |
| fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { |
| f.write_str(self.__description())?; |
| if let FromBytesWithNulErrorKind::InteriorNul(pos) = self.kind { |
| write!(f, " at byte pos {}", pos)?; |
| } |
| Ok(()) |
| } |
| } |
| |
| impl IntoStringError { |
| /// Consumes this error, returning original `CString` which generated the |
| /// error. |
| pub fn into_cstring(self) -> CString { |
| self.inner |
| } |
| |
| /// Access the underlying UTF-8 error that was the cause of this error. |
| pub fn utf8_error(&self) -> Utf8Error { |
| self.error |
| } |
| |
| pub fn __description(&self) -> &str { |
| "C string contained non-utf8 bytes" |
| } |
| |
| pub fn __cause(&self) -> Option<&Utf8Error> { |
| Some(&self.error) |
| } |
| } |
| |
| impl fmt::Display for IntoStringError { |
| fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { |
| self.__description().fmt(f) |
| } |
| } |
| |
| impl CStr { |
| /// Wraps a raw C string with a safe C string wrapper. |
| /// |
| /// This function will wrap the provided `ptr` with a `CStr` wrapper, which |
| /// allows inspection and interoperation of non-owned C strings. This method |
| /// is unsafe for a number of reasons: |
| /// |
| /// * There is no guarantee to the validity of `ptr`. |
| /// * The returned lifetime is not guaranteed to be the actual lifetime of |
| /// `ptr`. |
| /// * There is no guarantee that the memory pointed to by `ptr` contains a |
| /// valid nul terminator byte at the end of the string. |
| /// * It is not guaranteed that the memory pointed by `ptr` won't change |
| /// before the `CStr` has been destroyed. |
| /// |
| /// > **Note**: This operation is intended to be a 0-cost cast but it is |
| /// > currently implemented with an up-front calculation of the length of |
| /// > the string. This is not guaranteed to always be the case. |
| /// |
| pub unsafe fn from_ptr<'a>(ptr: *const c_char) -> &'a CStr { |
| let len = libc::strlen(ptr); |
| let ptr = ptr as *const u8; |
| CStr::from_bytes_with_nul_unchecked(slice::from_raw_parts(ptr, len as usize + 1)) |
| } |
| |
| /// Creates a C string wrapper from a byte slice. |
| /// |
| /// This function will cast the provided `bytes` to a `CStr` |
| /// wrapper after ensuring that the byte slice is nul-terminated |
| /// and does not contain any interior nul bytes. |
| /// |
| pub fn from_bytes_with_nul(bytes: &[u8]) |
| -> Result<&CStr, FromBytesWithNulError> { |
| let nul_pos = memchr::memchr(0, bytes); |
| if let Some(nul_pos) = nul_pos { |
| if nul_pos + 1 != bytes.len() { |
| return Err(FromBytesWithNulError::interior_nul(nul_pos)); |
| } |
| Ok(unsafe { CStr::from_bytes_with_nul_unchecked(bytes) }) |
| } else { |
| Err(FromBytesWithNulError::not_nul_terminated()) |
| } |
| } |
| |
| /// Unsafely creates a C string wrapper from a byte slice. |
| /// |
| /// This function will cast the provided `bytes` to a `CStr` wrapper without |
| /// performing any sanity checks. The provided slice **must** be nul-terminated |
| /// and not contain any interior nul bytes. |
| /// |
| pub unsafe fn from_bytes_with_nul_unchecked(bytes: &[u8]) -> &CStr { |
| &*(bytes as *const [u8] as *const CStr) |
| } |
| |
| /// Returns the inner pointer to this C string. |
| /// |
| /// The returned pointer will be valid for as long as `self` is, and points |
| /// to a contiguous region of memory terminated with a 0 byte to represent |
| /// the end of the string. |
| /// |
| pub fn as_ptr(&self) -> *const c_char { |
| self.inner.as_ptr() |
| } |
| |
| /// Converts this C string to a byte slice. |
| /// |
| /// The returned slice will **not** contain the trailing nul terminator that this C |
| /// string has. |
| /// |
| /// > **Note**: This method is currently implemented as a constant-time |
| /// > cast, but it is planned to alter its definition in the future to |
| /// > perform the length calculation whenever this method is called. |
| /// |
| pub fn to_bytes(&self) -> &[u8] { |
| let bytes = self.to_bytes_with_nul(); |
| &bytes[..bytes.len() - 1] |
| } |
| |
| /// Converts this C string to a byte slice containing the trailing 0 byte. |
| /// |
| /// This function is the equivalent of [`to_bytes`] except that it will retain |
| /// the trailing nul terminator instead of chopping it off. |
| /// |
| /// > **Note**: This method is currently implemented as a 0-cost cast, but |
| /// > it is planned to alter its definition in the future to perform the |
| /// > length calculation whenever this method is called. |
| /// |
| /// [`to_bytes`]: #method.to_bytes |
| /// |
| pub fn to_bytes_with_nul(&self) -> &[u8] { |
| unsafe { &*(&self.inner as *const [c_char] as *const [u8]) } |
| } |
| |
| /// Yields a [`&str`] slice if the `CStr` contains valid UTF-8. |
| /// |
| /// If the contents of the `CStr` are valid UTF-8 data, this |
| /// function will return the corresponding [`&str`] slice. Otherwise, |
| /// it will return an error with details of where UTF-8 validation failed. |
| /// |
| /// > **Note**: This method is currently implemented to check for validity |
| /// > after a constant-time cast, but it is planned to alter its definition |
| /// > in the future to perform the length calculation in addition to the |
| /// > UTF-8 check whenever this method is called. |
| /// |
| /// [`&str`]: ../primitive.str.html |
| /// |
| pub fn to_str(&self) -> Result<&str, str::Utf8Error> { |
| // NB: When CStr is changed to perform the length check in .to_bytes() |
| // instead of in from_ptr(), it may be worth considering if this should |
| // be rewritten to do the UTF-8 check inline with the length calculation |
| // instead of doing it afterwards. |
| str::from_utf8(self.to_bytes()) |
| } |
| |
| /// Converts a `CStr` into a [`Cow`]`<`[`str`]`>`. |
| /// |
| /// If the contents of the `CStr` are valid UTF-8 data, this |
| /// function will return a [`Cow`]`::`[`Borrowed`]`(`[`&str`]`)` |
| /// with the the corresponding [`&str`] slice. Otherwise, it will |
| /// replace any invalid UTF-8 sequences with `U+FFFD REPLACEMENT |
| /// CHARACTER` and return a [`Cow`]`::`[`Owned`]`(`[`String`]`)` |
| /// with the result. |
| /// |
| /// > **Note**: This method is currently implemented to check for validity |
| /// > after a constant-time cast, but it is planned to alter its definition |
| /// > in the future to perform the length calculation in addition to the |
| /// > UTF-8 check whenever this method is called. |
| /// |
| /// [`Cow`]: ../borrow/enum.Cow.html |
| /// [`Borrowed`]: ../borrow/enum.Cow.html#variant.Borrowed |
| /// [`str`]: ../primitive.str.html |
| /// [`String`]: ../string/struct.String.html |
| /// |
| pub fn to_string_lossy(&self) -> Cow<str> { |
| String::from_utf8_lossy(self.to_bytes()) |
| } |
| |
| /// Converts a [`Box`]`<CStr>` into a [`CString`] without copying or allocating. |
| /// |
| /// [`Box`]: ../boxed/struct.Box.html |
| /// [`CString`]: struct.CString.html |
| /// |
| pub fn into_c_string(self: Box<CStr>) -> CString { |
| let raw = Box::into_raw(self) as *mut [u8]; |
| CString { inner: unsafe { Box::from_raw(raw) } } |
| } |
| } |
| |
| impl PartialEq for CStr { |
| fn eq(&self, other: &CStr) -> bool { |
| self.to_bytes().eq(other.to_bytes()) |
| } |
| } |
| |
| impl Eq for CStr {} |
| |
| impl PartialOrd for CStr { |
| fn partial_cmp(&self, other: &CStr) -> Option<Ordering> { |
| self.to_bytes().partial_cmp(&other.to_bytes()) |
| } |
| } |
| |
| impl Ord for CStr { |
| fn cmp(&self, other: &CStr) -> Ordering { |
| self.to_bytes().cmp(&other.to_bytes()) |
| } |
| } |
| |
| impl ToOwned for CStr { |
| type Owned = CString; |
| |
| fn to_owned(&self) -> CString { |
| CString { inner: self.to_bytes_with_nul().into() } |
| } |
| } |
| |
| impl<'a> From<&'a CStr> for CString { |
| fn from(s: &'a CStr) -> CString { |
| s.to_owned() |
| } |
| } |
| |
| impl ops::Index<ops::RangeFull> for CString { |
| type Output = CStr; |
| |
| #[inline] |
| fn index(&self, _index: ops::RangeFull) -> &CStr { |
| self |
| } |
| } |
| |
| impl AsRef<CStr> for CStr { |
| #[inline] |
| fn as_ref(&self) -> &CStr { |
| self |
| } |
| } |
| |
| impl AsRef<CStr> for CString { |
| #[inline] |
| fn as_ref(&self) -> &CStr { |
| self |
| } |
| } |
| |