src/librustc_llvm/archive_ro.rs

   1 // Copyright 2013-2014 The Rust Project Developers. See the COPYRIGHT
   2 // file at the top-level directory of this distribution and at
   3 // http://rust-lang.org/COPYRIGHT.
   4 //
   5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
   6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
   8 // option. This file may not be copied, modified, or distributed
   9 // except according to those terms.
  10
  11 //! A wrapper around LLVM's archive (.a) code
  12
  13 use libc;
  14 use ArchiveRef;
  15
  16 use std::ffi::CString;
  17 use std::mem;
  18 use std::raw;
  19
  20 pub struct ArchiveRO {
  21     ptr: ArchiveRef,
  22 }
  23
  24 impl ArchiveRO {
  25     /// Opens a static archive for read-only purposes. This is more optimized
  26     /// than the `open` method because it uses LLVM's internal `Archive` class
  27     /// rather than shelling out to `ar` for everything.
  28     ///
  29     /// If this archive is used with a mutable method, then an error will be
  30     /// raised.
  31     pub fn open(dst: &Path) -> Option<ArchiveRO> {
  32         unsafe {
  33             let s = CString::new(dst.as_vec()).unwrap();
  34             let ar = ::LLVMRustOpenArchive(s.as_ptr());
  35             if ar.is_null() {
  36                 None
  37             } else {
  38                 Some(ArchiveRO { ptr: ar })
  39             }
  40         }
  41     }
  42
  43     /// Reads a file in the archive
  44     pub fn read<'a>(&'a self, file: &str) -> Option<&'a [u8]> {
  45         unsafe {
  46             let mut size = 0 as libc::size_t;
  47             let file = CString::new(file).unwrap();
  48             let ptr = ::LLVMRustArchiveReadSection(self.ptr, file.as_ptr(),
  49                                                    &mut size);
  50             if ptr.is_null() {
  51                 None
  52             } else {
  53                 Some(mem::transmute(raw::Slice {
  54                     data: ptr,
  55                     len: size as uint,
  56                 }))
  57             }
  58         }
  59     }
  60 }
  61
  62 impl Drop for ArchiveRO {
  63     fn drop(&mut self) {
  64         unsafe {
  65             ::LLVMRustDestroyArchive(self.ptr);
  66         }
  67     }
  68 }