Use AsRef<Path> instead of AsRef<OsStr> in yanix functions (#1950)

* Use AsRef<Path> instead of AsRef<OsStr> in yanix functions.

`AsRef<Path>` makes these more consistent with `std` interfaces, making
them easier to use outside of wasi-common.

Also, refactor the conversion to `CString` into a helper function.

* Reduce clutter from fully-qualifying names.

* rustfmt

crates/wasi-common/yanix/src/sys/bsd/filetime.rs

@@ -1,7 +1,7 @@
 //! This module consists of helper types and functions for dealing
 //! with setting the file times specific to BSD-style *nixes.
 use crate::filetime::FileTime;
-use crate::from_success_code;
+use crate::{cstr, from_success_code};
 use std::ffi::CStr;
 use std::fs::File;
 use std::io::Result;
@@ -21,7 +21,6 @@ pub fn utimensat(
     symlink_nofollow: bool,
 ) -> Result<()> {
     use crate::filetime::to_timespec;
-    use std::ffi::CString;
     use std::os::unix::prelude::*;
 
     // Attempt to use the `utimensat` syscall, but if it's not supported by the
@@ -33,10 +32,10 @@ pub fn utimensat(
             0
         };
 
-        let p = CString::new(path.as_bytes())?;
+        let path = cstr(path)?;
         let times = [to_timespec(&atime)?, to_timespec(&mtime)?];
         return from_success_code(unsafe {
-            func(dirfd.as_raw_fd(), p.as_ptr(), times.as_ptr(), flags)
+            func(dirfd.as_raw_fd(), path.as_ptr(), times.as_ptr(), flags)
         });
     }
 

crates/wasi-common/yanix/src/sys/emscripten/filetime.rs

@@ -1,7 +1,7 @@
 //! This module consists of helper types and functions for dealing
 //! with setting the file times specific to Emscripten.
 use crate::filetime::FileTime;
-use crate::from_success_code;
+use crate::{cstr, from_success_code};
 use std::fs::File;
 use std::io::Result;
 
@@ -15,7 +15,6 @@ pub fn utimensat(
     symlink_nofollow: bool,
 ) -> Result<()> {
     use crate::filetime::to_timespec;
-    use std::ffi::CString;
     use std::os::unix::prelude::*;
 
     let flags = if symlink_nofollow {
@@ -23,9 +22,9 @@ pub fn utimensat(
     } else {
         0
     };
-    let p = CString::new(path.as_bytes())?;
+    let path = cstr(path)?;
     let times = [to_timespec(&atime)?, to_timespec(&mtime)?];
     from_success_code(unsafe {
-        libc::utimensat(dirfd.as_raw_fd(), p.as_ptr(), times.as_ptr(), flags)
+        libc::utimensat(dirfd.as_raw_fd(), path.as_ptr(), times.as_ptr(), flags)
     })
 }

crates/wasi-common/yanix/src/sys/linux/filetime.rs

@@ -1,7 +1,7 @@
 //! This module consists of helper types and functions for dealing
 //! with setting the file times specific to Linux.
 use crate::filetime::FileTime;
-use crate::from_success_code;
+use crate::{cstr, from_success_code};
 use std::fs::File;
 use std::io::Result;
 use std::sync::atomic::{AtomicBool, Ordering::Relaxed};
@@ -20,7 +20,6 @@ pub fn utimensat(
     symlink_nofollow: bool,
 ) -> Result<()> {
     use crate::filetime::to_timespec;
-    use std::ffi::CString;
     use std::os::unix::prelude::*;
 
     let flags = if symlink_nofollow {
@@ -33,13 +32,13 @@ pub fn utimensat(
     // current kernel then fall back to an older syscall.
     static INVALID: AtomicBool = AtomicBool::new(false);
     if !INVALID.load(Relaxed) {
-        let p = CString::new(path.as_bytes())?;
+        let path = cstr(path)?;
         let times = [to_timespec(&atime)?, to_timespec(&mtime)?];
         let res = from_success_code(unsafe {
             libc::syscall(
                 libc::SYS_utimensat,
                 dirfd.as_raw_fd(),
-                p.as_ptr(),
+                path.as_ptr(),
                 times.as_ptr(),
                 flags,
             )

crates/wasi-common/yanix/src/sys/linux/utimesat.rs

@@ -1,6 +1,6 @@
 use crate::filetime::FileTime;
 use crate::filetime::FileTimeExt;
-use crate::from_success_code;
+use crate::{cstr, from_success_code};
 use std::fs;
 use std::io::Result;
 
@@ -15,16 +15,15 @@ pub fn utimesat(
     mtime: FileTime,
     symlink_nofollow: bool,
 ) -> Result<()> {
-    use std::ffi::CString;
     use std::os::unix::prelude::*;
     // emulate *at syscall by reading the path from a combination of
     // (fd, path)
-    let p = CString::new(path.as_bytes())?;
+    let path = cstr(path)?;
     let mut flags = libc::O_RDWR;
     if symlink_nofollow {
         flags |= libc::O_NOFOLLOW;
     }
-    let fd = unsafe { libc::openat(dirfd.as_raw_fd(), p.as_ptr(), flags) };
+    let fd = unsafe { libc::openat(dirfd.as_raw_fd(), path.as_ptr(), flags) };
     let f = unsafe { fs::File::from_raw_fd(fd) };
     let (atime, mtime) = get_times(atime, mtime, || f.metadata().map_err(Into::into))?;
     let times = [to_timeval(atime)?, to_timeval(mtime)?];