diff options
Diffstat (limited to 'library/std/src/sys/unix/weak.rs')
-rw-r--r-- | library/std/src/sys/unix/weak.rs | 53 |
1 files changed, 4 insertions, 49 deletions
diff --git a/library/std/src/sys/unix/weak.rs b/library/std/src/sys/unix/weak.rs index f5a4ce929..62ffee70b 100644 --- a/library/std/src/sys/unix/weak.rs +++ b/library/std/src/sys/unix/weak.rs @@ -1,9 +1,8 @@ //! Support for "weak linkage" to symbols on Unix //! -//! Some I/O operations we do in libstd require newer versions of OSes but we -//! need to maintain binary compatibility with older releases for now. In order -//! to use the new functionality when available we use this module for -//! detection. +//! Some I/O operations we do in std require newer versions of OSes but we need +//! to maintain binary compatibility with older releases for now. In order to +//! use the new functionality when available we use this module for detection. //! //! One option to use here is weak linkage, but that is unfortunately only //! really workable with ELF. Otherwise, use dlsym to get the symbol value at @@ -29,7 +28,7 @@ use crate::ptr; use crate::sync::atomic::{self, AtomicPtr, Ordering}; // We can use true weak linkage on ELF targets. -#[cfg(all(not(any(target_os = "macos", target_os = "ios")), not(bootstrap)))] +#[cfg(not(any(target_os = "macos", target_os = "ios")))] pub(crate) macro weak { (fn $name:ident($($t:ty),*) -> $ret:ty) => ( let ref $name: ExternWeak<unsafe extern "C" fn($($t),*) -> $ret> = { @@ -43,30 +42,14 @@ pub(crate) macro weak { ) } -#[cfg(all(not(any(target_os = "macos", target_os = "ios")), bootstrap))] -pub(crate) macro weak { - (fn $name:ident($($t:ty),*) -> $ret:ty) => ( - let ref $name: ExternWeak<unsafe extern "C" fn($($t),*) -> $ret> = { - extern "C" { - #[linkage = "extern_weak"] - static $name: *const libc::c_void; - } - #[allow(unused_unsafe)] - ExternWeak::new(unsafe { $name }) - }; - ) -} - // On non-ELF targets, use the dlsym approximation of weak linkage. #[cfg(any(target_os = "macos", target_os = "ios"))] pub(crate) use self::dlsym as weak; -#[cfg(not(bootstrap))] pub(crate) struct ExternWeak<F: Copy> { weak_ptr: Option<F>, } -#[cfg(not(bootstrap))] impl<F: Copy> ExternWeak<F> { #[inline] pub(crate) fn new(weak_ptr: Option<F>) -> Self { @@ -79,34 +62,6 @@ impl<F: Copy> ExternWeak<F> { } } -#[cfg(bootstrap)] -pub(crate) struct ExternWeak<F> { - weak_ptr: *const libc::c_void, - _marker: PhantomData<F>, -} - -#[cfg(bootstrap)] -impl<F> ExternWeak<F> { - #[inline] - pub(crate) fn new(weak_ptr: *const libc::c_void) -> Self { - ExternWeak { weak_ptr, _marker: PhantomData } - } -} - -#[cfg(bootstrap)] -impl<F> ExternWeak<F> { - #[inline] - pub(crate) fn get(&self) -> Option<F> { - unsafe { - if self.weak_ptr.is_null() { - None - } else { - Some(mem::transmute_copy::<*const libc::c_void, F>(&self.weak_ptr)) - } - } - } -} - pub(crate) macro dlsym { (fn $name:ident($($t:ty),*) -> $ret:ty) => ( dlsym!(fn $name($($t),*) -> $ret, stringify!($name)); |