diff options
| -rw-r--r-- | library/std/src/sys/pal/unix/fs.rs | 36 |
1 files changed, 13 insertions, 23 deletions
diff --git a/library/std/src/sys/pal/unix/fs.rs b/library/std/src/sys/pal/unix/fs.rs index 54fa31620ac..fdf011c1948 100644 --- a/library/std/src/sys/pal/unix/fs.rs +++ b/library/std/src/sys/pal/unix/fs.rs @@ -709,7 +709,7 @@ impl Iterator for ReadDir { // thread safety for readdir() as long an individual DIR* is not accessed // concurrently, which is sufficient for Rust. super::os::set_errno(0); - let entry_ptr = readdir64(self.inner.dirp.0); + let entry_ptr: *const dirent64 = readdir64(self.inner.dirp.0); if entry_ptr.is_null() { // We either encountered an error, or reached the end. Either way, // the next call to next() should return None. @@ -735,29 +735,19 @@ impl Iterator for ReadDir { // contents were "simply" partially initialized data. // // Like for uninitialized contents, converting entry_ptr to `&dirent64` - // would not be legal. However, unique to dirent64 is that we don't even - // get to use `&raw const (*entry_ptr).d_name` because that operation - // requires the full extent of *entry_ptr to be in bounds of the same - // allocation, which is not necessarily the case here. - // - // Instead we must access fields individually through their offsets. - macro_rules! offset_ptr { - ($entry_ptr:expr, $field:ident) => {{ - const OFFSET: isize = mem::offset_of!(dirent64, $field) as isize; - if true { - // Cast to the same type determined by the else branch. - $entry_ptr.byte_offset(OFFSET).cast::<_>() - } else { - #[allow(deref_nullptr)] - { - &raw const (*ptr::null::<dirent64>()).$field - } - } - }}; + // would not be legal. However, we can use `&raw const (*entry_ptr).d_name` + // to refer the fields individually, because that operation is equivalent + // to `byte_offset` and thus does not require the full extent of `*entry_ptr` + // to be in bounds of the same allocation, only the offset of the field + // being referenced. + macro_rules! entry_field_ptr { + ($field:ident) => { + &raw const (*entry_ptr).$field + }; } // d_name is guaranteed to be null-terminated. - let name = CStr::from_ptr(offset_ptr!(entry_ptr, d_name).cast()); + let name = CStr::from_ptr(entry_field_ptr!(d_name).cast()); let name_bytes = name.to_bytes(); if name_bytes == b"." || name_bytes == b".." { continue; @@ -765,14 +755,14 @@ impl Iterator for ReadDir { #[cfg(not(target_os = "vita"))] let entry = dirent64_min { - d_ino: *offset_ptr!(entry_ptr, d_ino) as u64, + d_ino: *entry_field_ptr!(d_ino) as u64, #[cfg(not(any( target_os = "solaris", target_os = "illumos", target_os = "aix", target_os = "nto", )))] - d_type: *offset_ptr!(entry_ptr, d_type) as u8, + d_type: *entry_field_ptr!(d_type) as u8, }; #[cfg(target_os = "vita")] |