std: Move platform specific memchr code into sys

2 files changed, 58 insertions, 0 deletions

diff --git a/src/libstd/sys/unix/memchr.rs b/src/libstd/sys/unix/memchr.rs
new file mode 100644
index 00000000000..5038e0750c8
--- /dev/null
+++ b/src/libstd/sys/unix/memchr.rs
@@ -0,0 +1,57 @@
+// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+//
+// Original implementation taken from rust-memchr
+// Copyright 2015 Andrew Gallant, bluss and Nicolas Koch
+
+pub fn memchr(needle: u8, haystack: &[u8]) -> Option<usize> {
+    use libc;
+
+    let p = unsafe {
+        libc::memchr(
+            haystack.as_ptr() as *const libc::c_void,
+            needle as libc::c_int,
+            haystack.len() as libc::size_t)
+    };
+    if p.is_null() {
+        None
+    } else {
+        Some(p as usize - (haystack.as_ptr() as usize))
+    }
+}
+
+pub fn memrchr(needle: u8, haystack: &[u8]) -> Option<usize> {
+
+    #[cfg(target_os = "linux")]
+    fn memrchr_specific(needle: u8, haystack: &[u8]) -> Option<usize> {
+        use libc;
+
+        // 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() as libc::size_t)
+        };
+        if p.is_null() {
+            None
+        } else {
+            Some(p as usize - (haystack.as_ptr() as usize))
+        }
+    }
+
+    #[cfg(not(target_os = "linux"))]
+    fn memrchr_specific(needle: u8, haystack: &[u8]) -> Option<usize> {
+        ::sys_common::memchr::fallback::memrchr(needle, haystack)
+    }
+
+    memrchr_specific(needle, haystack)
+}
diff --git a/src/libstd/sys/unix/mod.rs b/src/libstd/sys/unix/mod.rs
index abe7018f25d..c4763e1739e 100644
--- a/src/libstd/sys/unix/mod.rs
+++ b/src/libstd/sys/unix/mod.rs
@@ -38,6 +38,7 @@ pub mod env;
 pub mod ext;
 pub mod fd;
 pub mod fs;
+pub mod memchr;
 pub mod mutex;
 pub mod net;
 pub mod os;