rust/src/librustc_llvm/archive_ro.rs
Alex Crichton ec7a50d20d std: Redesign c_str and c_vec
This commit is an implementation of [RFC 494][rfc] which removes the entire
`std::c_vec` module and redesigns the `std::c_str` module as `std::ffi`.

[rfc]: https://github.com/rust-lang/rfcs/blob/master/text/0494-c_str-and-c_vec-stability.md

The interface of the new `CString` is outlined in the linked RFC, the primary
changes being:

* The `ToCStr` trait is gone, meaning the `with_c_str` and `to_c_str` methods
  are now gone. These two methods are replaced with a `CString::from_slice`
  method.
* The `CString` type is now just a wrapper around `Vec<u8>` with a static
  guarantee that there is a trailing nul byte with no internal nul bytes. This
  means that `CString` now implements `Deref<Target = [c_char]>`, which is where
  it gains most of its methods from. A few helper methods are added to acquire a
  slice of `u8` instead of `c_char`, as well as including a slice with the
  trailing nul byte if necessary.
* All usage of non-owned `CString` values is now done via two functions inside
  of `std::ffi`, called `c_str_to_bytes` and `c_str_to_bytes_with_nul`. These
  functions are now the one method used to convert a `*const c_char` to a Rust
  slice of `u8`.

Many more details, including newly deprecated methods, can be found linked in
the RFC. This is a:

[breaking-change]
Closes #20444
2015-01-05 08:00:13 -08:00

69 lines
2.0 KiB
Rust

// Copyright 2013-2014 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.
//! A wrapper around LLVM's archive (.a) code
use libc;
use ArchiveRef;
use std::ffi::CString;
use std::mem;
use std::raw;
pub struct ArchiveRO {
ptr: ArchiveRef,
}
impl ArchiveRO {
/// Opens a static archive for read-only purposes. This is more optimized
/// than the `open` method because it uses LLVM's internal `Archive` class
/// rather than shelling out to `ar` for everything.
///
/// If this archive is used with a mutable method, then an error will be
/// raised.
pub fn open(dst: &Path) -> Option<ArchiveRO> {
unsafe {
let s = CString::from_slice(dst.as_vec());
let ar = ::LLVMRustOpenArchive(s.as_ptr());
if ar.is_null() {
None
} else {
Some(ArchiveRO { ptr: ar })
}
}
}
/// Reads a file in the archive
pub fn read<'a>(&'a self, file: &str) -> Option<&'a [u8]> {
unsafe {
let mut size = 0 as libc::size_t;
let file = CString::from_slice(file.as_bytes());
let ptr = ::LLVMRustArchiveReadSection(self.ptr, file.as_ptr(),
&mut size);
if ptr.is_null() {
None
} else {
Some(mem::transmute(raw::Slice {
data: ptr,
len: size as uint,
}))
}
}
}
}
impl Drop for ArchiveRO {
fn drop(&mut self) {
unsafe {
::LLVMRustDestroyArchive(self.ptr);
}
}
}