From 786ea3ffe64209ea68421013f7721288dfab1f6d Mon Sep 17 00:00:00 2001 From: Steven Stewart-Gallus Date: Sat, 8 Jun 2013 23:29:32 -0700 Subject: [PATCH] Prototyped a dynamic library facility interface --- src/libstd/unstable/dynamic_lib.rs | 199 +++++++++++++++++++++++++++++ src/libstd/unstable/mod.rs | 8 ++ 2 files changed, 207 insertions(+) create mode 100644 src/libstd/unstable/dynamic_lib.rs diff --git a/src/libstd/unstable/dynamic_lib.rs b/src/libstd/unstable/dynamic_lib.rs new file mode 100644 index 0000000000000..96aba1d2971e8 --- /dev/null +++ b/src/libstd/unstable/dynamic_lib.rs @@ -0,0 +1,199 @@ +// Copyright 2013 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 or the MIT license +// , at your +// option. This file may not be copied, modified, or distributed +// except according to those terms. + +/*! + +Dynamic library facilities. + +A simple wrapper over the platforms dynamic library facilities + +*/ +use ptr; +use cast; +use path; +use libc; +use ops::*; +use option::*; +use result::*; + +pub struct DynamicLibrary { priv handle: *libc::c_void } + +impl Drop for DynamicLibrary { + fn finalize(&self) { + match do dl::check_for_errors_in { + unsafe { + dl::close(self.handle) + } + } { + Ok(()) => { }, + Err(str) => fail!(str) + } + } +} + +impl DynamicLibrary { + /// Lazily open a dynamic library. When passed None it gives a + /// handle to the calling process + pub fn open(filename: Option<&path::Path>) -> Result { + let open_wrapper = |raw_ptr| { + do dl::check_for_errors_in { + unsafe { + DynamicLibrary { handle: dl::open(raw_ptr) } + } + } + }; + + match filename { + Some(name) => do name.to_str().as_c_str |raw_name| { + open_wrapper(raw_name) + }, + None => open_wrapper(ptr::null()) + } + } + + /// Access the value at the symbol of the dynamic library + pub unsafe fn symbol(&self, symbol: &str) -> Result { + // This function should have a lifetime constraint of 'self on + // T but that feature is still unimplemented + + do dl::check_for_errors_in { + let symbol_value = do symbol.as_c_str |raw_string| { + dl::symbol(self.handle, raw_string) + }; + + cast::transmute(symbol_value) + } + } +} + +#[test] +priv fn test_loading_cosine () { + // The math library does not need to be loaded since it is already + // statically linked in + let libm = match DynamicLibrary::open(None) { + Err (error) => fail!("Could not load self as module: %s", error), + Ok (libm) => libm + }; + + // Unfortunately due to issue #6194 it is not possible to call + // this as a C function + let cosine: extern fn(libc::c_double) -> libc::c_double = unsafe { + match libm.symbol("cos") { + Err (error) => fail!("Could not load function cos: %s", error), + Ok (cosine) => cosine + } + }; + + let argument = 0.0; + let expected_result = 1.0; + let result = cosine(argument); + if result != expected_result { + fail!("cos(%?) != %? but equaled %? instead", argument, + expected_result, result) + } +} + +#[cfg(target_os = "linux")] +#[cfg(target_os = "android")] +#[cfg(target_os = "macos")] +#[cfg(target_os = "freebsd")] +mod dl { + use libc; + use ptr; + use str; + use task; + use result::*; + + pub unsafe fn open(filename: *libc::c_char) -> *libc::c_void { + dlopen(filename, Lazy as libc::c_int) + } + + pub fn check_for_errors_in(f: &fn()->T) -> Result { + unsafe { + do task::atomically { + let _old_error = dlerror(); + + let result = f(); + + let last_error = dlerror(); + if ptr::null() == last_error { + Ok(result) + } else { + Err(str::raw::from_c_str(last_error)) + } + } + } + } + + pub unsafe fn symbol(handle: *libc::c_void, symbol: *libc::c_char) -> *libc::c_void { + dlsym(handle, symbol) + } + pub unsafe fn close(handle: *libc::c_void) { + dlclose(handle); () + } + + pub enum RTLD { + Lazy = 1, + Now = 2, + Global = 256, + Local = 0, + } + + #[link_name = "dl"] + extern { + fn dlopen(filename: *libc::c_char, flag: libc::c_int) -> *libc::c_void; + fn dlerror() -> *libc::c_char; + fn dlsym(handle: *libc::c_void, symbol: *libc::c_char) -> *libc::c_void; + fn dlclose(handle: *libc::c_void) -> libc::c_int; + } +} + +#[cfg(target_os = "win32")] +mod dl { + use os; + use libc; + use task; + use result::*; + + pub unsafe fn open(filename: *libc::c_char) -> *libc::c_void { + LoadLibrary(filename) + } + + pub fn check_for_errors_in(f: &fn()->T) -> Result { + unsafe { + do task::atomically { + SetLastError(0); + + let result = f(); + + let error = os::errno(); + if 0 == error { + Ok(result) + } else { + Err(fmt!("Error code %?", error)) + } + } + } + } + pub unsafe fn symbol(handle: *libc::c_void, symbol: *libc::c_char) -> *libc::c_void { + GetProcAddress(handle, symbol) + } + pub unsafe fn close(handle: *libc::c_void) { + FreeLibrary(handle); () + } + + #[link_name = "kernel32"] + extern "stdcall" { + fn SetLastError(error: u32); + fn LoadLibrary(name: *libc::c_char) -> *libc::c_void; + fn GetProcAddress(handle: *libc::c_void, name: *libc::c_char) -> *libc::c_void; + fn FreeLibrary(handle: *libc::c_void); + } +} diff --git a/src/libstd/unstable/mod.rs b/src/libstd/unstable/mod.rs index 1e226da271d48..ae87805014255 100644 --- a/src/libstd/unstable/mod.rs +++ b/src/libstd/unstable/mod.rs @@ -17,6 +17,14 @@ use prelude::*; use task; pub mod at_exit; + +// Currently only works for *NIXes +#[cfg(target_os = "linux")] +#[cfg(target_os = "android")] +#[cfg(target_os = "macos")] +#[cfg(target_os = "freebsd")] +pub mod dynamic_lib; + pub mod global; pub mod finally; pub mod weak_task;