Auto merge of #30759 - Manishearth:attr-tls, r=alexcrichton

fixes #30756

r? @Gankro

src/libstd/thread/local.rs

@@ -92,7 +92,7 @@ pub struct LocalKey<T: 'static> {
     // trivially devirtualizable by LLVM because the value of `inner` never
     // changes and the constant should be readonly within a crate. This mainly
     // only runs into problems when TLS statics are exported across crates.
-    inner: unsafe fn() -> Option<&'static UnsafeCell<Option<T>>>,
+    inner: fn() -> Option<&'static UnsafeCell<Option<T>>>,
 
     // initialization routine to invoke to create a value
     init: fn() -> T,
@@ -126,7 +126,7 @@ macro_rules! __thread_local_inner {
     ($t:ty, $init:expr) => {{
         fn __init() -> $t { $init }
 
-        unsafe fn __getit() -> $crate::option::Option<
+        fn __getit() -> $crate::option::Option<
             &'static $crate::cell::UnsafeCell<
                 $crate::option::Option<$t>>>
         {
@@ -183,7 +183,7 @@ impl<T: 'static> LocalKey<T> {
     #[unstable(feature = "thread_local_internals",
                reason = "recently added to create a key",
                issue = "0")]
-    pub const fn new(inner: unsafe fn() -> Option<&'static UnsafeCell<Option<T>>>,
+    pub const fn new(inner: fn() -> Option<&'static UnsafeCell<Option<T>>>,
                      init: fn() -> T) -> LocalKey<T> {
         LocalKey {
             inner: inner,
@@ -303,11 +303,13 @@ pub mod elf {
             }
         }
 
-        pub unsafe fn get(&'static self) -> Option<&'static UnsafeCell<Option<T>>> {
+        pub fn get(&'static self) -> Option<&'static UnsafeCell<Option<T>>> {
+            unsafe {
                 if intrinsics::needs_drop::<T>() && self.dtor_running.get() {
                     return None
                 }
                 self.register_dtor();
+            }
             Some(&self.inner)
         }
 
@@ -452,7 +454,8 @@ pub mod os {
             }
         }
 
-        pub unsafe fn get(&'static self) -> Option<&'static UnsafeCell<Option<T>>> {
+        pub fn get(&'static self) -> Option<&'static UnsafeCell<Option<T>>> {
+            unsafe {
                 let ptr = self.os.get() as *mut Value<T>;
                 if !ptr.is_null() {
                     if ptr as usize == 1 {
@@ -472,6 +475,7 @@ pub mod os {
                 Some(&(*ptr).value)
             }
         }
+    }
 
     pub unsafe extern fn destroy_value<T: 'static>(ptr: *mut u8) {
         // The OS TLS ensures that this key contains a NULL value when this

src/test/run-pass/issue-30756.rs

@@ -0,0 +1,16 @@
+// Copyright 2016 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.
+
+#![deny(unsafe_code)]
+
+thread_local!(static FOO: u8 = 1);
+
+fn main() {
+}