std: Expand the area of std::fs

This commit is an implementation of [RFC 1044][rfc] which adds additional
surface area to the `std::fs` module. All new APIs are `#[unstable]` behind
assorted feature names for each one.

[rfc]: https://github.com/rust-lang/rfcs/pull/1044

The new APIs added are:

* `fs::canonicalize` - bindings to `realpath` on unix and
  `GetFinalPathNameByHandle` on windows.
* `fs::symlink_metadata` - similar to `lstat` on unix
* `fs::FileType` and accessor methods as `is_{file,dir,symlink}`
* `fs::Metadata::file_type` - accessor for the raw file type
* `fs::DirEntry::metadata` - acquisition of metadata which is free on Windows
  but requires a syscall on unix.
* `fs::DirEntry::file_type` - access the file type which may not require a
  syscall on most platforms.
* `fs::DirEntry::file_name` - access just the file name without leading
  components.
* `fs::PathExt::symlink_metadata` - convenience method for the top-level
  function.
* `fs::PathExt::canonicalize` - convenience method for the top-level
  function.
* `fs::PathExt::read_link` - convenience method for the top-level
  function.
* `fs::PathExt::read_dir` - convenience method for the top-level
  function.
* `std::os::raw` - type definitions for raw OS/C types available on all
  platforms.
* `std::os::$platform` - new modules have been added for all currently supported
  platforms (e.g. those more specific than just `unix`).
* `std::os::$platform::raw` - platform-specific type definitions. These modules
  are populated with the bare essentials necessary for lowing I/O types into
  their raw representations, and currently largely consist of the `stat`
  definition for unix platforms.

This commit also deprecates `Metadata::{modified, accessed}` in favor of
inspecting the raw representations via the lowering methods of `Metadata`.

1 files changed, 92 insertions, 0 deletions

diff --git a/src/libstd/os/raw.rs b/src/libstd/os/raw.rs
new file mode 100644
index 00000000000..44f4a1c828b
--- /dev/null
+++ b/src/libstd/os/raw.rs
@@ -0,0 +1,92 @@
+// 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.
+
+//! Raw OS-specific types for the current platform/architecture
+
+#![unstable(feature = "raw_os", reason = "recently added API")]
+
+#[cfg(target_arch = "aarch64")]      pub type c_char = u8;
+#[cfg(not(target_arch = "aarch64"))] pub type c_char = i8;
+pub type c_schar = i8;
+pub type c_uchar = u8;
+pub type c_short = i16;
+pub type c_ushort = u16;
+pub type c_int = i32;
+pub type c_uint = u32;
+#[cfg(any(target_pointer_width = "32", windows))] pub type c_long = i32;
+#[cfg(any(target_pointer_width = "32", windows))] pub type c_ulong = u32;
+#[cfg(all(target_pointer_width = "64", not(windows)))] pub type c_long = i64;
+#[cfg(all(target_pointer_width = "64", not(windows)))] pub type c_ulong = u64;
+pub type c_longlong = i64;
+pub type c_ulonglong = u64;
+pub type c_float = f32;
+pub type c_double = f64;
+
+/// Type used to construct void pointers for use with C.
+///
+/// This type is only useful as a pointer target. Do not use it as a
+/// return type for FFI functions which have the `void` return type in
+/// C. Use the unit type `()` or omit the return type instead.
+// NB: For LLVM to recognize the void pointer type and by extension
+//     functions like malloc(), we need to have it represented as i8* in
+//     LLVM bitcode. The enum used here ensures this and prevents misuse
+//     of the "raw" type by only having private variants.. We need two
+//     variants, because the compiler complains about the repr attribute
+//     otherwise.
+#[repr(u8)]
+pub enum c_void {
+    #[doc(hidden)] __variant1,
+    #[doc(hidden)] __variant2,
+}
+
+#[cfg(test)]
+mod tests {
+    use any::TypeId;
+    use libc;
+    use mem;
+
+    macro_rules! ok {
+        ($($t:ident)*) => {$(
+            assert!(TypeId::of::<libc::$t>() == TypeId::of::<raw::$t>(),
+                    "{} is wrong", stringify!($t));
+        )*}
+    }
+
+    macro_rules! ok_size {
+        ($($t:ident)*) => {$(
+            assert!(mem::size_of::<libc::$t>() == mem::size_of::<raw::$t>(),
+                    "{} is wrong", stringify!($t));
+        )*}
+    }
+
+    #[test]
+    fn same() {
+        use os::raw;
+        ok!(c_char c_schar c_uchar c_short c_ushort c_int c_uint c_long c_ulong
+            c_longlong c_ulonglong c_float c_double);
+    }
+
+    #[cfg(unix)]
+    fn unix() {
+        {
+            use os::unix::raw;
+            ok!(uid_t gid_t dev_t ino_t mode_t nlink_t off_t blksize_t blkcnt_t);
+        }
+        {
+            use sys::platform::raw;
+            ok_size!(stat);
+        }
+    }
+
+    #[cfg(windows)]
+    fn windows() {
+        use os::windows::raw;
+    }
+}