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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 12:02:58 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 12:02:58 +0000 |
commit | 698f8c2f01ea549d77d7dc3338a12e04c11057b9 (patch) | |
tree | 173a775858bd501c378080a10dca74132f05bc50 /library/std/src/sys/unix/memchr.rs | |
parent | Initial commit. (diff) | |
download | rustc-698f8c2f01ea549d77d7dc3338a12e04c11057b9.tar.xz rustc-698f8c2f01ea549d77d7dc3338a12e04c11057b9.zip |
Adding upstream version 1.64.0+dfsg1.upstream/1.64.0+dfsg1
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | library/std/src/sys/unix/memchr.rs | 40 |
1 files changed, 40 insertions, 0 deletions
diff --git a/library/std/src/sys/unix/memchr.rs b/library/std/src/sys/unix/memchr.rs new file mode 100644 index 000000000..73ba604ec --- /dev/null +++ b/library/std/src/sys/unix/memchr.rs @@ -0,0 +1,40 @@ +// Original implementation taken from rust-memchr. +// Copyright 2015 Andrew Gallant, bluss and Nicolas Koch + +pub fn memchr(needle: u8, haystack: &[u8]) -> Option<usize> { + let p = unsafe { + libc::memchr( + haystack.as_ptr() as *const libc::c_void, + needle as libc::c_int, + haystack.len(), + ) + }; + if p.is_null() { None } else { Some(p.addr() - haystack.as_ptr().addr()) } +} + +pub fn memrchr(needle: u8, haystack: &[u8]) -> Option<usize> { + #[cfg(target_os = "linux")] + fn memrchr_specific(needle: u8, haystack: &[u8]) -> Option<usize> { + // GNU's memrchr() will - unlike memchr() - error if haystack is empty. + if haystack.is_empty() { + return None; + } + let p = unsafe { + libc::memrchr( + haystack.as_ptr() as *const libc::c_void, + needle as libc::c_int, + haystack.len(), + ) + }; + // FIXME: this should *likely* use `offset_from`, but more + // investigation is needed (including running tests in miri). + if p.is_null() { None } else { Some(p.addr() - haystack.as_ptr().addr()) } + } + + #[cfg(not(target_os = "linux"))] + fn memrchr_specific(needle: u8, haystack: &[u8]) -> Option<usize> { + core::slice::memchr::memrchr(needle, haystack) + } + + memrchr_specific(needle, haystack) +} |