diff options
Diffstat (limited to 'library/std/src/sys/windows/stdio.rs')
-rw-r--r-- | library/std/src/sys/windows/stdio.rs | 75 |
1 files changed, 47 insertions, 28 deletions
diff --git a/library/std/src/sys/windows/stdio.rs b/library/std/src/sys/windows/stdio.rs index 70c9b14a0..32c6ccffb 100644 --- a/library/std/src/sys/windows/stdio.rs +++ b/library/std/src/sys/windows/stdio.rs @@ -1,6 +1,5 @@ #![unstable(issue = "none", feature = "windows_stdio")] -use crate::char::decode_utf16; use crate::cmp; use crate::io; use crate::mem::MaybeUninit; @@ -170,14 +169,27 @@ fn write( } fn write_valid_utf8_to_console(handle: c::HANDLE, utf8: &str) -> io::Result<usize> { + debug_assert!(!utf8.is_empty()); + let mut utf16 = [MaybeUninit::<u16>::uninit(); MAX_BUFFER_SIZE / 2]; - let mut len_utf16 = 0; - for (chr, dest) in utf8.encode_utf16().zip(utf16.iter_mut()) { - *dest = MaybeUninit::new(chr); - len_utf16 += 1; - } - // Safety: We've initialized `len_utf16` values. - let utf16: &[u16] = unsafe { MaybeUninit::slice_assume_init_ref(&utf16[..len_utf16]) }; + let utf8 = &utf8[..utf8.floor_char_boundary(utf16.len())]; + + let utf16: &[u16] = unsafe { + // Note that this theoretically checks validity twice in the (most common) case + // where the underlying byte sequence is valid utf-8 (given the check in `write()`). + let result = c::MultiByteToWideChar( + c::CP_UTF8, // CodePage + c::MB_ERR_INVALID_CHARS, // dwFlags + utf8.as_ptr() as c::LPCCH, // lpMultiByteStr + utf8.len() as c::c_int, // cbMultiByte + utf16.as_mut_ptr() as c::LPWSTR, // lpWideCharStr + utf16.len() as c::c_int, // cchWideChar + ); + assert!(result != 0, "Unexpected error in MultiByteToWideChar"); + + // Safety: MultiByteToWideChar initializes `result` values. + MaybeUninit::slice_assume_init_ref(&utf16[..result as usize]) + }; let mut written = write_u16s(handle, &utf16)?; @@ -190,8 +202,8 @@ fn write_valid_utf8_to_console(handle: c::HANDLE, utf8: &str) -> io::Result<usiz // a missing surrogate can be produced (and also because of the UTF-8 validation above), // write the missing surrogate out now. // Buffering it would mean we have to lie about the number of bytes written. - let first_char_remaining = utf16[written]; - if first_char_remaining >= 0xDCEE && first_char_remaining <= 0xDFFF { + let first_code_unit_remaining = utf16[written]; + if first_code_unit_remaining >= 0xDCEE && first_code_unit_remaining <= 0xDFFF { // low surrogate // We just hope this works, and give up otherwise let _ = write_u16s(handle, &utf16[written..written + 1]); @@ -213,6 +225,7 @@ fn write_valid_utf8_to_console(handle: c::HANDLE, utf8: &str) -> io::Result<usiz } fn write_u16s(handle: c::HANDLE, data: &[u16]) -> io::Result<usize> { + debug_assert!(data.len() < u32::MAX as usize); let mut written = 0; cvt(unsafe { c::WriteConsoleW( @@ -366,26 +379,32 @@ fn read_u16s(handle: c::HANDLE, buf: &mut [MaybeUninit<u16>]) -> io::Result<usiz Ok(amount as usize) } -#[allow(unused)] fn utf16_to_utf8(utf16: &[u16], utf8: &mut [u8]) -> io::Result<usize> { - let mut written = 0; - for chr in decode_utf16(utf16.iter().cloned()) { - match chr { - Ok(chr) => { - chr.encode_utf8(&mut utf8[written..]); - written += chr.len_utf8(); - } - Err(_) => { - // We can't really do any better than forget all data and return an error. - return Err(io::const_io_error!( - io::ErrorKind::InvalidData, - "Windows stdin in console mode does not support non-UTF-16 input; \ - encountered unpaired surrogate", - )); - } - } + debug_assert!(utf16.len() <= c::c_int::MAX as usize); + debug_assert!(utf8.len() <= c::c_int::MAX as usize); + + let result = unsafe { + c::WideCharToMultiByte( + c::CP_UTF8, // CodePage + c::WC_ERR_INVALID_CHARS, // dwFlags + utf16.as_ptr(), // lpWideCharStr + utf16.len() as c::c_int, // cchWideChar + utf8.as_mut_ptr() as c::LPSTR, // lpMultiByteStr + utf8.len() as c::c_int, // cbMultiByte + ptr::null(), // lpDefaultChar + ptr::null_mut(), // lpUsedDefaultChar + ) + }; + if result == 0 { + // We can't really do any better than forget all data and return an error. + Err(io::const_io_error!( + io::ErrorKind::InvalidData, + "Windows stdin in console mode does not support non-UTF-16 input; \ + encountered unpaired surrogate", + )) + } else { + Ok(result as usize) } - Ok(written) } impl IncompleteUtf8 { |