Use const fn to abstract away the contents of UnsafeCell & friends.

Author: eddyb

src/libcollectionstest/vec.rs

@@ -399,7 +399,7 @@ fn test_map_in_place_zero_sized() {
 
 #[test]
 fn test_map_in_place_zero_drop_count() {
-    use std::sync::atomic::{AtomicUsize, Ordering, ATOMIC_USIZE_INIT};
+    use std::sync::atomic::{AtomicUsize, Ordering};
 
     #[derive(Clone, PartialEq, Debug)]
     struct Nothing;
@@ -413,7 +413,7 @@ fn test_map_in_place_zero_drop_count() {
         }
     }
     const NUM_ELEMENTS: usize = 2;
-    static DROP_COUNTER: AtomicUsize = ATOMIC_USIZE_INIT;
+    static DROP_COUNTER: AtomicUsize = AtomicUsize::new(0);
 
     let v = repeat(Nothing).take(NUM_ELEMENTS).collect::<Vec<_>>();
 

src/libcore/atomic.rs

@@ -76,7 +76,6 @@ use marker::Sync;
 
 use intrinsics;
 use cell::UnsafeCell;
-use marker::PhantomData;
 
 use default::Default;
 
@@ -87,8 +86,8 @@ pub struct AtomicBool {
 }
 
 impl Default for AtomicBool {
-    fn default() -> AtomicBool {
-        ATOMIC_BOOL_INIT
+    fn default() -> Self {
+        Self::new(Default::default())
     }
 }
 
@@ -101,8 +100,8 @@ pub struct AtomicIsize {
 }
 
 impl Default for AtomicIsize {
-    fn default() -> AtomicIsize {
-        ATOMIC_ISIZE_INIT
+    fn default() -> Self {
+        Self::new(Default::default())
     }
 }
 
@@ -115,8 +114,8 @@ pub struct AtomicUsize {
 }
 
 impl Default for AtomicUsize {
-    fn default() -> AtomicUsize {
-        ATOMIC_USIZE_INIT
+    fn default() -> Self {
+        Self::new(Default::default())
     }
 }
 
@@ -125,8 +124,7 @@ unsafe impl Sync for AtomicUsize {}
 /// A raw pointer type which can be safely shared between threads.
 #[stable(feature = "rust1", since = "1.0.0")]
 pub struct AtomicPtr<T> {
-    p: UnsafeCell<usize>,
-    _marker: PhantomData<*mut T>,
+    p: UnsafeCell<*mut T>,
 }
 
 impl<T> Default for AtomicPtr<T> {
@@ -175,16 +173,13 @@ pub enum Ordering {
 
 /// An `AtomicBool` initialized to `false`.
 #[stable(feature = "rust1", since = "1.0.0")]
-pub const ATOMIC_BOOL_INIT: AtomicBool =
-        AtomicBool { v: UnsafeCell { value: 0 } };
+pub const ATOMIC_BOOL_INIT: AtomicBool = AtomicBool::new(false);
 /// An `AtomicIsize` initialized to `0`.
 #[stable(feature = "rust1", since = "1.0.0")]
-pub const ATOMIC_ISIZE_INIT: AtomicIsize =
-        AtomicIsize { v: UnsafeCell { value: 0 } };
+pub const ATOMIC_ISIZE_INIT: AtomicIsize = AtomicIsize::new(0);
 /// An `AtomicUsize` initialized to `0`.
 #[stable(feature = "rust1", since = "1.0.0")]
-pub const ATOMIC_USIZE_INIT: AtomicUsize =
-        AtomicUsize { v: UnsafeCell { value: 0, } };
+pub const ATOMIC_USIZE_INIT: AtomicUsize = AtomicUsize::new(0);
 
 // NB: Needs to be -1 (0b11111111...) to make fetch_nand work correctly
 const UINT_TRUE: usize = !0;
@@ -202,9 +197,8 @@ impl AtomicBool {
     /// ```
     #[inline]
     #[stable(feature = "rust1", since = "1.0.0")]
-    pub fn new(v: bool) -> AtomicBool {
-        let val = if v { UINT_TRUE } else { 0 };
-        AtomicBool { v: UnsafeCell::new(val) }
+    pub const fn new(v: bool) -> AtomicBool {
+        AtomicBool { v: UnsafeCell::new(-(v as isize) as usize) }
     }
 
     /// Loads a value from the bool.
@@ -445,7 +439,7 @@ impl AtomicIsize {
     /// ```
     #[inline]
     #[stable(feature = "rust1", since = "1.0.0")]
-    pub fn new(v: isize) -> AtomicIsize {
+    pub const fn new(v: isize) -> AtomicIsize {
         AtomicIsize {v: UnsafeCell::new(v)}
     }
 
@@ -633,7 +627,7 @@ impl AtomicUsize {
     /// ```
     #[inline]
     #[stable(feature = "rust1", since = "1.0.0")]
-    pub fn new(v: usize) -> AtomicUsize {
+    pub const fn new(v: usize) -> AtomicUsize {
         AtomicUsize { v: UnsafeCell::new(v) }
     }
 
@@ -821,9 +815,8 @@ impl<T> AtomicPtr<T> {
     /// ```
     #[inline]
     #[stable(feature = "rust1", since = "1.0.0")]
-    pub fn new(p: *mut T) -> AtomicPtr<T> {
-        AtomicPtr { p: UnsafeCell::new(p as usize),
-                    _marker: PhantomData }
+    pub const fn new(p: *mut T) -> AtomicPtr<T> {
+        AtomicPtr { p: UnsafeCell::new(p) }
     }
 
     /// Loads a value from the pointer.
@@ -848,7 +841,7 @@ impl<T> AtomicPtr<T> {
     #[stable(feature = "rust1", since = "1.0.0")]
     pub fn load(&self, order: Ordering) -> *mut T {
         unsafe {
-            atomic_load(self.p.get(), order) as *mut T
+            atomic_load(self.p.get() as *mut usize, order) as *mut T
         }
     }
 
@@ -875,7 +868,7 @@ impl<T> AtomicPtr<T> {
     #[inline]
     #[stable(feature = "rust1", since = "1.0.0")]
     pub fn store(&self, ptr: *mut T, order: Ordering) {
-        unsafe { atomic_store(self.p.get(), ptr as usize, order); }
+        unsafe { atomic_store(self.p.get() as *mut usize, ptr as usize, order); }
     }
 
     /// Stores a value into the pointer, returning the old value.
@@ -897,7 +890,7 @@ impl<T> AtomicPtr<T> {
     #[inline]
     #[stable(feature = "rust1", since = "1.0.0")]
     pub fn swap(&self, ptr: *mut T, order: Ordering) -> *mut T {
-        unsafe { atomic_swap(self.p.get(), ptr as usize, order) as *mut T }
+        unsafe { atomic_swap(self.p.get() as *mut usize, ptr as usize, order) as *mut T }
     }
 
     /// Stores a value into the pointer if the current value is the same as the expected value.
@@ -925,7 +918,7 @@ impl<T> AtomicPtr<T> {
     #[stable(feature = "rust1", since = "1.0.0")]
     pub fn compare_and_swap(&self, old: *mut T, new: *mut T, order: Ordering) -> *mut T {
         unsafe {
-            atomic_compare_and_swap(self.p.get(), old as usize,
+            atomic_compare_and_swap(self.p.get() as *mut usize, old as usize,
                                     new as usize, order) as *mut T
         }
     }

src/libcore/cell.rs

@@ -170,7 +170,7 @@ impl<T:Copy> Cell<T> {
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
     #[inline]
-    pub fn new(value: T) -> Cell<T> {
+    pub const fn new(value: T) -> Cell<T> {
         Cell {
             value: UnsafeCell::new(value),
         }
@@ -302,7 +302,7 @@ impl<T> RefCell<T> {
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
     #[inline]
-    pub fn new(value: T) -> RefCell<T> {
+    pub const fn new(value: T) -> RefCell<T> {
         RefCell {
             value: UnsafeCell::new(value),
             borrow: Cell::new(UNUSED),
@@ -663,7 +663,7 @@ impl<T> UnsafeCell<T> {
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
     #[inline]
-    pub fn new(value: T) -> UnsafeCell<T> {
+    pub const fn new(value: T) -> UnsafeCell<T> {
         UnsafeCell { value: value }
     }
 

src/libcore/lib.rs

@@ -74,6 +74,7 @@
 #![feature(concat_idents)]
 #![feature(reflect)]
 #![feature(custom_attribute)]
+#![feature(const_fn)]
 
 #[macro_use]
 mod macros;

src/libcoretest/atomic.rs

@@ -70,13 +70,15 @@ fn int_xor() {
     assert_eq!(x.load(SeqCst), 0xf731 ^ 0x137f);
 }
 
-static S_BOOL : AtomicBool = ATOMIC_BOOL_INIT;
-static S_INT  : AtomicIsize  = ATOMIC_ISIZE_INIT;
-static S_UINT : AtomicUsize = ATOMIC_USIZE_INIT;
+static S_FALSE: AtomicBool = AtomicBool::new(false);
+static S_TRUE: AtomicBool = AtomicBool::new(true);
+static S_INT: AtomicIsize  = AtomicIsize::new(0);
+static S_UINT: AtomicUsize = AtomicUsize::new(0);
 
 #[test]
 fn static_init() {
-    assert!(!S_BOOL.load(SeqCst));
+    assert!(!S_FALSE.load(SeqCst));
+    assert!(S_TRUE.load(SeqCst));
     assert!(S_INT.load(SeqCst) == 0);
     assert!(S_UINT.load(SeqCst) == 0);
 }

src/liblog/lib.rs

@@ -184,7 +184,7 @@ use std::mem;
 use std::env;
 use std::rt;
 use std::slice;
-use std::sync::{Once, ONCE_INIT, StaticMutex, MUTEX_INIT};
+use std::sync::{Once, StaticMutex};
 
 use directive::LOG_LEVEL_NAMES;
 
@@ -200,7 +200,7 @@ pub const MAX_LOG_LEVEL: u32 = 255;
 /// The default logging level of a crate if no other is specified.
 const DEFAULT_LOG_LEVEL: u32 = 1;
 
-static LOCK: StaticMutex = MUTEX_INIT;
+static LOCK: StaticMutex = StaticMutex::new();
 
 /// An unsafe constant that is the maximum logging level of any module
 /// specified. This is the first line of defense to determining whether a
@@ -367,7 +367,7 @@ pub struct LogLocation {
 /// module's log statement should be emitted or not.
 #[doc(hidden)]
 pub fn mod_enabled(level: u32, module: &str) -> bool {
-    static INIT: Once = ONCE_INIT;
+    static INIT: Once = Once::new();
     INIT.call_once(init);
 
     // It's possible for many threads are in this function, only one of them

src/librustc/middle/infer/region_inference/graphviz.rs

@@ -32,7 +32,7 @@ use std::env;
 use std::fs::File;
 use std::io;
 use std::io::prelude::*;
-use std::sync::atomic::{AtomicBool, Ordering, ATOMIC_BOOL_INIT};
+use std::sync::atomic::{AtomicBool, Ordering};
 use syntax::ast;
 
 fn print_help_message() {
@@ -76,7 +76,7 @@ pub fn maybe_print_constraints_for<'a, 'tcx>(region_vars: &RegionVarBindings<'a,
     let output_path = {
         let output_template = match requested_output {
             Ok(ref s) if &**s == "help" => {
-                static PRINTED_YET: AtomicBool = ATOMIC_BOOL_INIT;
+                static PRINTED_YET: AtomicBool = AtomicBool::new(false);
                 if !PRINTED_YET.load(Ordering::SeqCst) {
                     print_help_message();
                     PRINTED_YET.store(true, Ordering::SeqCst);

src/librustc_trans/back/write.rs

@@ -1005,8 +1005,8 @@ pub fn run_assembler(sess: &Session, outputs: &OutputFilenames) {
 }
 
 unsafe fn configure_llvm(sess: &Session) {
-    use std::sync::{Once, ONCE_INIT};
-    static INIT: Once = ONCE_INIT;
+    use std::sync::Once;
+    static INIT: Once = Once::new();
 
     // Copy what clang does by turning on loop vectorization at O2 and
     // slp vectorization at O3

src/librustc_trans/lib.rs

@@ -39,6 +39,7 @@
 #![feature(path_ext)]
 #![feature(fs)]
 #![feature(path_relative_from)]
+#![feature(std_misc)]
 
 #![allow(trivial_casts)]
 

src/librustc_trans/trans/base.rs

@@ -2653,8 +2653,8 @@ pub fn trans_crate<'tcx>(analysis: ty::CrateAnalysis<'tcx>)
 
     // Before we touch LLVM, make sure that multithreading is enabled.
     unsafe {
-        use std::sync::{Once, ONCE_INIT};
-        static INIT: Once = ONCE_INIT;
+        use std::sync::Once;
+        static INIT: Once = Once::new();
         static mut POISONED: bool = false;
         INIT.call_once(|| {
             if llvm::LLVMStartMultithreaded() != 1 {

src/libstd/dynamic_lib.rs

@@ -211,8 +211,8 @@ mod dl {
     pub fn check_for_errors_in<T, F>(f: F) -> Result<T, String> where
         F: FnOnce() -> T,
     {
-        use sync::{StaticMutex, MUTEX_INIT};
-        static LOCK: StaticMutex = MUTEX_INIT;
+        use sync::StaticMutex;
+        static LOCK: StaticMutex = StaticMutex::new();
         unsafe {
             // dlerror isn't thread safe, so we need to lock around this entire
             // sequence

src/libstd/env.rs

@@ -23,8 +23,8 @@ use ffi::{OsStr, OsString};
 use fmt;
 use io;
 use path::{Path, PathBuf};
-use sync::atomic::{AtomicIsize, ATOMIC_ISIZE_INIT, Ordering};
-use sync::{StaticMutex, MUTEX_INIT};
+use sync::atomic::{AtomicIsize, Ordering};
+use sync::StaticMutex;
 use sys::os as os_imp;
 
 /// Returns the current working directory as a `PathBuf`.
@@ -70,7 +70,7 @@ pub fn set_current_dir<P: AsRef<Path>>(p: P) -> io::Result<()> {
     os_imp::chdir(p.as_ref())
 }
 
-static ENV_LOCK: StaticMutex = MUTEX_INIT;
+static ENV_LOCK: StaticMutex = StaticMutex::new();
 
 /// An iterator over a snapshot of the environment variables of this process.
 ///
@@ -475,7 +475,7 @@ pub fn current_exe() -> io::Result<PathBuf> {
     os_imp::current_exe()
 }
 
-static EXIT_STATUS: AtomicIsize = ATOMIC_ISIZE_INIT;
+static EXIT_STATUS: AtomicIsize = AtomicIsize::new(0);
 
 /// Sets the process exit code
 ///

src/libstd/io/lazy.rs

@@ -11,31 +11,31 @@
 use prelude::v1::*;
 
 use boxed;
-use cell::UnsafeCell;
+use cell::Cell;
 use rt;
 use sync::{StaticMutex, Arc};
 
 pub struct Lazy<T> {
-    pub lock: StaticMutex,
-    pub ptr: UnsafeCell<*mut Arc<T>>,
-    pub init: fn() -> Arc<T>,
+    lock: StaticMutex,
+    ptr: Cell<*mut Arc<T>>,
+    init: fn() -> Arc<T>,
 }
 
 unsafe impl<T> Sync for Lazy<T> {}
 
-macro_rules! lazy_init {
-    ($init:expr) => (::io::lazy::Lazy {
-        lock: ::sync::MUTEX_INIT,
-        ptr: ::cell::UnsafeCell { value: 0 as *mut _ },
-        init: $init,
-    })
-}
-
 impl<T: Send + Sync + 'static> Lazy<T> {
+    pub const fn new(init: fn() -> Arc<T>) -> Lazy<T> {
+        Lazy {
+            lock: StaticMutex::new(),
+            ptr: Cell::new(0 as *mut _),
+            init: init
+        }
+    }
+
     pub fn get(&'static self) -> Option<Arc<T>> {
         let _g = self.lock.lock();
+        let ptr = self.ptr.get();
         unsafe {
-            let ptr = *self.ptr.get();
             if ptr.is_null() {
                 Some(self.init())
             } else if ptr as usize == 1 {
@@ -53,14 +53,14 @@ impl<T: Send + Sync + 'static> Lazy<T> {
         // `Arc`.
         let registered = rt::at_exit(move || {
             let g = self.lock.lock();
-            let ptr = *self.ptr.get();
-            *self.ptr.get() = 1 as *mut _;
+            let ptr = self.ptr.get();
+            self.ptr.set(1 as *mut _);
             drop(g);
             drop(Box::from_raw(ptr))
         });
         let ret = (self.init)();
         if registered.is_ok() {
-            *self.ptr.get() = boxed::into_raw(Box::new(ret.clone()));
+            self.ptr.set(boxed::into_raw(Box::new(ret.clone())));
         }
         return ret
     }