From 7d296c4843785f64a4246213375b21c1ab1e7462 Mon Sep 17 00:00:00 2001 From: Vitali Lovich Date: Fri, 2 Feb 2018 11:17:48 -0800 Subject: Add Condvar APIs not susceptible to spurious wake Provide wait_until and wait_timeout_until helper wrappers that aren't susceptible to spurious wake. --- src/libstd/sync/condvar.rs | 207 ++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 205 insertions(+), 2 deletions(-) (limited to 'src/libstd/sync') diff --git a/src/libstd/sync/condvar.rs b/src/libstd/sync/condvar.rs index 56402175817..1e5beaaa342 100644 --- a/src/libstd/sync/condvar.rs +++ b/src/libstd/sync/condvar.rs @@ -14,7 +14,7 @@ use sync::{mutex, MutexGuard, PoisonError}; use sys_common::condvar as sys; use sys_common::mutex as sys_mutex; use sys_common::poison::{self, LockResult}; -use time::Duration; +use time::{Duration, Instant}; /// A type indicating whether a timed wait on a condition variable returned /// due to a time out or not. @@ -219,6 +219,61 @@ impl Condvar { } } + /// Blocks the current thread until this condition variable receives a + /// notification and the required condition is met. There are no spurious + /// wakeups when calling this. + /// + /// This function will atomically unlock the mutex specified (represented by + /// `guard`) and block the current thread. This means that any calls + /// to [`notify_one`] or [`notify_all`] which happen logically after the + /// mutex is unlocked are candidates to wake this thread up. When this + /// function call returns, the lock specified will have been re-acquired. + /// + /// # Errors + /// + /// This function will return an error if the mutex being waited on is + /// poisoned when this thread re-acquires the lock. For more information, + /// see information about [poisoning] on the [`Mutex`] type. + /// + /// [`notify_one`]: #method.notify_one + /// [`notify_all`]: #method.notify_all + /// [poisoning]: ../sync/struct.Mutex.html#poisoning + /// [`Mutex`]: ../sync/struct.Mutex.html + /// + /// # Examples + /// + /// ``` + /// use std::sync::{Arc, Mutex, Condvar}; + /// use std::thread; + /// + /// let pair = Arc::new((Mutex::new(false), Condvar::new())); + /// let pair2 = pair.clone(); + /// + /// thread::spawn(move|| { + /// let &(ref lock, ref cvar) = &*pair2; + /// let mut started = lock.lock().unwrap(); + /// *started = true; + /// // We notify the condvar that the value has changed. + /// cvar.notify_one(); + /// }); + /// + /// // Wait for the thread to start up. + /// let &(ref lock, ref cvar) = &*pair; + /// // As long as the value inside the `Mutex` is false, we wait. + /// cvar.wait_until(lock.lock().unwrap(), |ref started| { started }); + /// ``` + #[stable(feature = "wait_until", since = "1.24")] + pub fn wait_until<'a, T, F>(&self, mut guard: MutexGuard<'a, T>, + mut condition: F) + -> LockResult> + where F: FnMut(&T) -> bool { + while !condition(&*guard) { + guard = self.wait(guard)?; + } + Ok(guard) + } + + /// Waits on this condition variable for a notification, timing out after a /// specified duration. /// @@ -293,7 +348,15 @@ impl Condvar { /// /// Note that the best effort is made to ensure that the time waited is /// measured with a monotonic clock, and not affected by the changes made to - /// the system time. + /// the system time. This function is susceptible to spurious wakeups. + /// Condition variables normally have a boolean predicate associated with + /// them, and the predicate must always be checked each time this function + /// returns to protect against spurious wakeups. Additionally, it is + /// typically desirable for the time-out to not exceed some duration in + /// spite of spurious wakes, thus the sleep-duration is decremented by the + /// amount slept. Alternatively, use the `wait_timeout_until` method + /// to wait until a condition is met with a total time-out regardless + /// of spurious wakes. /// /// The returned [`WaitTimeoutResult`] value indicates if the timeout is /// known to have elapsed. @@ -302,6 +365,7 @@ impl Condvar { /// returns, regardless of whether the timeout elapsed or not. /// /// [`wait`]: #method.wait + /// [`wait_timeout_until`]: #method.wait_timeout_until /// [`WaitTimeoutResult`]: struct.WaitTimeoutResult.html /// /// # Examples @@ -353,6 +417,76 @@ impl Condvar { } } + /// Waits on this condition variable for a notification, timing out after a + /// specified duration. + /// + /// The semantics of this function are equivalent to [`wait_until`] except + /// that the thread will be blocked for roughly no longer than `dur`. This + /// method should not be used for precise timing due to anomalies such as + /// preemption or platform differences that may not cause the maximum + /// amount of time waited to be precisely `dur`. + /// + /// Note that the best effort is made to ensure that the time waited is + /// measured with a monotonic clock, and not affected by the changes made to + /// the system time. + /// + /// The returned [`WaitTimeoutResult`] value indicates if the timeout is + /// known to have elapsed without the condition being met. + /// + /// Like [`wait_until`], the lock specified will be re-acquired when this + /// function returns, regardless of whether the timeout elapsed or not. + /// + /// [`wait_until`]: #method.wait_until + /// [`wait_timeout`]: #method.wait_timeout + /// [`WaitTimeoutResult`]: struct.WaitTimeoutResult.html + /// + /// # Examples + /// + /// ``` + /// use std::sync::{Arc, Mutex, Condvar}; + /// use std::thread; + /// use std::time::Duration; + /// + /// let pair = Arc::new((Mutex::new(false), Condvar::new())); + /// let pair2 = pair.clone(); + /// + /// thread::spawn(move|| { + /// let &(ref lock, ref cvar) = &*pair2; + /// let mut started = lock.lock().unwrap(); + /// *started = true; + /// // We notify the condvar that the value has changed. + /// cvar.notify_one(); + /// }); + /// + /// // wait for the thread to start up + /// let &(ref lock, ref cvar) = &*pair; + /// let result = cvar.wait_timeout_until(lock, Duration::from_millis(100), |started| { + /// started + /// }).unwrap(); + /// if result.1.timed_out() { + /// // timed-out without the condition ever evaluating to true. + /// } + /// // access the locked mutex via result.0 + /// ``` + #[stable(feature = "wait_timeout_until", since = "1.24")] + pub fn wait_timeout_until<'a, T, F>(&self, mut guard: MutexGuard<'a, T>, + mut dur: Duration, mut condition: F) + -> LockResult<(MutexGuard<'a, T>, WaitTimeoutResult)> + where F: FnMut(&T) -> bool { + let timed_out = Duration::new(0, 0); + loop { + if !condition(&*guard) { + return Ok((guard, WaitTimeoutResult(false))); + } else if dur == timed_out { + return Ok((guard, WaitTimeoutResult(false))); + } + let wait_timer = Instant::now(); + let wait_result = self.wait_timeout(guard, dur)?; + dur = dur.checked_sub(wait_timer.elapsed()).unwrap_or(timed_out); + guard = wait_result.0; + } + } + /// Wakes up one blocked thread on this condvar. /// /// If there is a blocked thread on this condition variable, then it will @@ -546,6 +680,29 @@ mod tests { } } + #[test] + #[cfg_attr(target_os = "emscripten", ignore)] + fn wait_until() { + let pair = Arc::new((Mutex::new(false), Condvar::new())); + let pair2 = pair.clone(); + + // Inside of our lock, spawn a new thread, and then wait for it to start. + thread::spawn(move|| { + let &(ref lock, ref cvar) = &*pair2; + let mut started = lock.lock().unwrap(); + *started = true; + // We notify the condvar that the value has changed. + cvar.notify_one(); + }); + + // Wait for the thread to start up. + let &(ref lock, ref cvar) = &*pair; + let guard = cvar.wait_until(lock.lock().unwrap(), |started| { + started + }); + assert!(*guard); + } + #[test] #[cfg_attr(target_os = "emscripten", ignore)] fn wait_timeout_wait() { @@ -565,6 +722,52 @@ mod tests { } } + #[test] + #[cfg_attr(target_os = "emscripten", ignore)] + fn wait_timeout_until_wait() { + let m = Arc::new(Mutex::new(())); + let c = Arc::new(Condvar::new()); + + let g = m.lock().unwrap(); + let (_g, wait) = c.wait_timeout_until(g, Duration::from_millis(1), || { false }).unwrap(); + // no spurious wakeups. ensure it timed-out + assert!(wait.timed_out()); + } + + #[test] + #[cfg_attr(target_os = "emscripten", ignore)] + fn wait_timeout_until_instant_satisfy() { + let m = Arc::new(Mutex::new(())); + let c = Arc::new(Condvar::new()); + + let g = m.lock().unwrap(); + let (_g, wait) = c.wait_timeout_until(g, Duration::from_millis(0), || { true }).unwrap(); + // ensure it didn't time-out even if we were not given any time. + assert!(!wait.timed_out()); + } + + #[test] + #[cfg_attr(target_os = "emscripten", ignore)] + fn wait_timeout_until_wake() { + let pair = Arc::new((Mutex::new(false), Condvar::new())); + let pair_copy = pair.clone(); + + let g = m.lock().unwrap(); + let t = thread::spawn(move || { + let &(ref lock, ref cvar) = &*pair2; + let mut started = lock.lock().unwrap(); + thread::sleep(Duration::from_millis(1)); + started = true; + cvar.notify_one(); + }); + let (g2, wait) = c.wait_timeout_until(g, Duration::from_millis(u64::MAX), |¬ified| { + notified + }).unwrap(); + // ensure it didn't time-out even if we were not given any time. + assert!(!wait.timed_out()); + assert!(*g2); + } + #[test] #[cfg_attr(target_os = "emscripten", ignore)] fn wait_timeout_wake() { -- cgit 1.4.1-3-g733a5 From 404e1a67007a254ab35e4fe8a8650e9335590a76 Mon Sep 17 00:00:00 2001 From: Vitali Lovich Date: Fri, 2 Feb 2018 11:52:16 -0800 Subject: Fix typo --- src/libstd/sync/condvar.rs | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'src/libstd/sync') diff --git a/src/libstd/sync/condvar.rs b/src/libstd/sync/condvar.rs index 1e5beaaa342..c58f8fd2990 100644 --- a/src/libstd/sync/condvar.rs +++ b/src/libstd/sync/condvar.rs @@ -478,7 +478,7 @@ impl Condvar { if !condition(&*guard) { return Ok((guard, WaitTimeoutResult(false))); } else if dur == timed_out { - return Ok((guard, WaitTimeoutResult(false))); + return Ok((guard, WaitTimeoutResult(true))); } let wait_timer = Instant::now(); let wait_result = self.wait_timeout(guard, dur)?; -- cgit 1.4.1-3-g733a5 From e72bd6df5398dd7ee02c6057b861537c49649b4e Mon Sep 17 00:00:00 2001 From: Vitali Lovich Date: Fri, 2 Feb 2018 12:07:16 -0800 Subject: Review response Make condition closure accept mut T&. Clarify spurious wakeup documentation. Cleanup doc example code. --- src/libstd/sync/condvar.rs | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-) (limited to 'src/libstd/sync') diff --git a/src/libstd/sync/condvar.rs b/src/libstd/sync/condvar.rs index c58f8fd2990..76b68fc4f4f 100644 --- a/src/libstd/sync/condvar.rs +++ b/src/libstd/sync/condvar.rs @@ -220,8 +220,9 @@ impl Condvar { } /// Blocks the current thread until this condition variable receives a - /// notification and the required condition is met. There are no spurious - /// wakeups when calling this. + /// notification and the required condition is met. Spurious wakeups are + /// ignored and this function will only return once the condition has been + /// met. /// /// This function will atomically unlock the mutex specified (represented by /// `guard`) and block the current thread. This means that any calls @@ -260,14 +261,14 @@ impl Condvar { /// // Wait for the thread to start up. /// let &(ref lock, ref cvar) = &*pair; /// // As long as the value inside the `Mutex` is false, we wait. - /// cvar.wait_until(lock.lock().unwrap(), |ref started| { started }); + /// cvar.wait_until(lock.lock().unwrap(), |started| { started }); /// ``` #[stable(feature = "wait_until", since = "1.24")] pub fn wait_until<'a, T, F>(&self, mut guard: MutexGuard<'a, T>, mut condition: F) -> LockResult> - where F: FnMut(&T) -> bool { - while !condition(&*guard) { + where F: FnMut(&mut T) -> bool { + while !condition(&mut *guard) { guard = self.wait(guard)?; } Ok(guard) @@ -418,7 +419,8 @@ impl Condvar { } /// Waits on this condition variable for a notification, timing out after a - /// specified duration. + /// specified duration. Spurious wakes will not cause this function to + /// return. /// /// The semantics of this function are equivalent to [`wait_until`] except /// that the thread will be blocked for roughly no longer than `dur`. This @@ -472,10 +474,10 @@ impl Condvar { pub fn wait_timeout_until<'a, T, F>(&self, mut guard: MutexGuard<'a, T>, mut dur: Duration, mut condition: F) -> LockResult<(MutexGuard<'a, T>, WaitTimeoutResult)> - where F: FnMut(&T) -> bool { + where F: FnMut(&mut T) -> bool { let timed_out = Duration::new(0, 0); loop { - if !condition(&*guard) { + if !condition(&mut *guard) { return Ok((guard, WaitTimeoutResult(false))); } else if dur == timed_out { return Ok((guard, WaitTimeoutResult(true))); -- cgit 1.4.1-3-g733a5 From 95e4dc2ad143c91d0930ea28634e6f5c54ac0812 Mon Sep 17 00:00:00 2001 From: Vitali Lovich Date: Mon, 5 Feb 2018 15:11:00 -0800 Subject: Simplify wait_timeout_until & fix condition typo --- src/libstd/sync/condvar.rs | 15 +++++++-------- 1 file changed, 7 insertions(+), 8 deletions(-) (limited to 'src/libstd/sync') diff --git a/src/libstd/sync/condvar.rs b/src/libstd/sync/condvar.rs index 76b68fc4f4f..e6a3388aa25 100644 --- a/src/libstd/sync/condvar.rs +++ b/src/libstd/sync/condvar.rs @@ -475,17 +475,16 @@ impl Condvar { mut dur: Duration, mut condition: F) -> LockResult<(MutexGuard<'a, T>, WaitTimeoutResult)> where F: FnMut(&mut T) -> bool { - let timed_out = Duration::new(0, 0); + let start = Instant::now(); loop { - if !condition(&mut *guard) { + if condition(&mut *guard) { return Ok((guard, WaitTimeoutResult(false))); - } else if dur == timed_out { - return Ok((guard, WaitTimeoutResult(true))); } - let wait_timer = Instant::now(); - let wait_result = self.wait_timeout(guard, dur)?; - dur = dur.checked_sub(wait_timer.elapsed()).unwrap_or(timed_out); - guard = wait_result.0; + let timeout = match dur.checked_sub(start.elapsed()) { + Some(timeout) => timeout, + None => return Ok((guard, WaitTimeoutResult(true))), + } + guard = self.wait_timeout(guard, dur)?.0; } } -- cgit 1.4.1-3-g733a5 From 97df227d19791b0e9d199be28851fb924c3c1e21 Mon Sep 17 00:00:00 2001 From: Vitali Lovich Date: Mon, 12 Feb 2018 21:08:14 -0800 Subject: Fix wait_timeout value --- src/libstd/sync/condvar.rs | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'src/libstd/sync') diff --git a/src/libstd/sync/condvar.rs b/src/libstd/sync/condvar.rs index e6a3388aa25..65235aa62a1 100644 --- a/src/libstd/sync/condvar.rs +++ b/src/libstd/sync/condvar.rs @@ -484,7 +484,7 @@ impl Condvar { Some(timeout) => timeout, None => return Ok((guard, WaitTimeoutResult(true))), } - guard = self.wait_timeout(guard, dur)?.0; + guard = self.wait_timeout(guard, timeout)?.0; } } -- cgit 1.4.1-3-g733a5 From 6fe2d1d765810c05ce2aa2184baa9f4aabf1a151 Mon Sep 17 00:00:00 2001 From: Vitali Lovich Date: Tue, 13 Feb 2018 11:32:04 -0800 Subject: Misc fixes Switch feature guards to unstable Add missing semicolon Remove mut that's no longer necessary --- src/libstd/sync/condvar.rs | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'src/libstd/sync') diff --git a/src/libstd/sync/condvar.rs b/src/libstd/sync/condvar.rs index 65235aa62a1..98fadbd3543 100644 --- a/src/libstd/sync/condvar.rs +++ b/src/libstd/sync/condvar.rs @@ -263,7 +263,7 @@ impl Condvar { /// // As long as the value inside the `Mutex` is false, we wait. /// cvar.wait_until(lock.lock().unwrap(), |started| { started }); /// ``` - #[stable(feature = "wait_until", since = "1.24")] + #[unstable(feature = "wait_until", issue = "47960")] pub fn wait_until<'a, T, F>(&self, mut guard: MutexGuard<'a, T>, mut condition: F) -> LockResult> @@ -470,9 +470,9 @@ impl Condvar { /// } /// // access the locked mutex via result.0 /// ``` - #[stable(feature = "wait_timeout_until", since = "1.24")] + #[unstable(feature = "wait_timeout_until", issue = "47960")] pub fn wait_timeout_until<'a, T, F>(&self, mut guard: MutexGuard<'a, T>, - mut dur: Duration, mut condition: F) + dur: Duration, mut condition: F) -> LockResult<(MutexGuard<'a, T>, WaitTimeoutResult)> where F: FnMut(&mut T) -> bool { let start = Instant::now(); @@ -483,7 +483,7 @@ impl Condvar { let timeout = match dur.checked_sub(start.elapsed()) { Some(timeout) => timeout, None => return Ok((guard, WaitTimeoutResult(true))), - } + }; guard = self.wait_timeout(guard, timeout)?.0; } } -- cgit 1.4.1-3-g733a5 From ba6a6d0f0a047bc211e69bcbf0934ae6b651f415 Mon Sep 17 00:00:00 2001 From: Guillaume Gomez Date: Thu, 15 Feb 2018 18:59:00 +0100 Subject: Fix condvar example --- src/libstd/sync/condvar.rs | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'src/libstd/sync') diff --git a/src/libstd/sync/condvar.rs b/src/libstd/sync/condvar.rs index 56402175817..54bb6513650 100644 --- a/src/libstd/sync/condvar.rs +++ b/src/libstd/sync/condvar.rs @@ -47,11 +47,13 @@ impl WaitTimeoutResult { /// /// thread::spawn(move|| { /// let &(ref lock, ref cvar) = &*pair2; + /// + /// // Let's wait 20 milliseconds before notifying the condvar. + /// thread::sleep(Duration::from_millis(20)); + /// /// let mut started = lock.lock().unwrap(); /// // We update the boolean value. /// *started = true; - /// // Let's wait 20 milliseconds before notifying the condvar. - /// thread::sleep(Duration::from_millis(20)); /// cvar.notify_one(); /// }); /// -- cgit 1.4.1-3-g733a5 From b1f04a3a2e1a01ea1b77153dd8d22e7837542aa0 Mon Sep 17 00:00:00 2001 From: Vitali Lovich Date: Thu, 15 Feb 2018 09:28:25 -0800 Subject: Fix unit test compilation Also fix some code snippets in documentation. --- src/libstd/sync/condvar.rs | 28 +++++++++++++++++----------- 1 file changed, 17 insertions(+), 11 deletions(-) (limited to 'src/libstd/sync') diff --git a/src/libstd/sync/condvar.rs b/src/libstd/sync/condvar.rs index 98fadbd3543..546e105deb7 100644 --- a/src/libstd/sync/condvar.rs +++ b/src/libstd/sync/condvar.rs @@ -244,6 +244,8 @@ impl Condvar { /// # Examples /// /// ``` + /// #![feature(wait_until)] + /// /// use std::sync::{Arc, Mutex, Condvar}; /// use std::thread; /// @@ -261,7 +263,7 @@ impl Condvar { /// // Wait for the thread to start up. /// let &(ref lock, ref cvar) = &*pair; /// // As long as the value inside the `Mutex` is false, we wait. - /// cvar.wait_until(lock.lock().unwrap(), |started| { started }); + /// let _guard = cvar.wait_until(lock.lock().unwrap(), |started| { *started }).unwrap(); /// ``` #[unstable(feature = "wait_until", issue = "47960")] pub fn wait_until<'a, T, F>(&self, mut guard: MutexGuard<'a, T>, @@ -445,6 +447,8 @@ impl Condvar { /// # Examples /// /// ``` + /// #![feature(wait_timeout_until)] + /// /// use std::sync::{Arc, Mutex, Condvar}; /// use std::thread; /// use std::time::Duration; @@ -462,8 +466,8 @@ impl Condvar { /// /// // wait for the thread to start up /// let &(ref lock, ref cvar) = &*pair; - /// let result = cvar.wait_timeout_until(lock, Duration::from_millis(100), |started| { - /// started + /// let result = cvar.wait_timeout_until(lock.lock().unwrap(), Duration::from_millis(100), |started| { + /// *started /// }).unwrap(); /// if result.1.timed_out() { /// // timed-out without the condition ever evaluating to true. @@ -613,6 +617,7 @@ impl Drop for Condvar { #[cfg(test)] mod tests { + /// #![feature(wait_until)] use sync::mpsc::channel; use sync::{Condvar, Mutex, Arc}; use sync::atomic::{AtomicBool, Ordering}; @@ -699,9 +704,9 @@ mod tests { // Wait for the thread to start up. let &(ref lock, ref cvar) = &*pair; let guard = cvar.wait_until(lock.lock().unwrap(), |started| { - started + *started }); - assert!(*guard); + assert!(*guard.unwrap()); } #[test] @@ -730,7 +735,7 @@ mod tests { let c = Arc::new(Condvar::new()); let g = m.lock().unwrap(); - let (_g, wait) = c.wait_timeout_until(g, Duration::from_millis(1), || { false }).unwrap(); + let (_g, wait) = c.wait_timeout_until(g, Duration::from_millis(1), |_| { false }).unwrap(); // no spurious wakeups. ensure it timed-out assert!(wait.timed_out()); } @@ -742,7 +747,7 @@ mod tests { let c = Arc::new(Condvar::new()); let g = m.lock().unwrap(); - let (_g, wait) = c.wait_timeout_until(g, Duration::from_millis(0), || { true }).unwrap(); + let (_g, wait) = c.wait_timeout_until(g, Duration::from_millis(0), |_| { true }).unwrap(); // ensure it didn't time-out even if we were not given any time. assert!(!wait.timed_out()); } @@ -753,15 +758,16 @@ mod tests { let pair = Arc::new((Mutex::new(false), Condvar::new())); let pair_copy = pair.clone(); + let &(ref m, ref c) = &*pair; let g = m.lock().unwrap(); - let t = thread::spawn(move || { - let &(ref lock, ref cvar) = &*pair2; + let _t = thread::spawn(move || { + let &(ref lock, ref cvar) = &*pair_copy; let mut started = lock.lock().unwrap(); thread::sleep(Duration::from_millis(1)); - started = true; + *started = true; cvar.notify_one(); }); - let (g2, wait) = c.wait_timeout_until(g, Duration::from_millis(u64::MAX), |¬ified| { + let (g2, wait) = c.wait_timeout_until(g, Duration::from_millis(u64::MAX), |&mut notified| { notified }).unwrap(); // ensure it didn't time-out even if we were not given any time. -- cgit 1.4.1-3-g733a5 From 4452446292086d9c92ea709eea61a31cedb55e22 Mon Sep 17 00:00:00 2001 From: Matthias Krüger Date: Fri, 16 Feb 2018 15:56:50 +0100 Subject: fix more typos found by codespell. --- RELEASES.md | 2 +- config.toml.example | 4 ++-- src/bootstrap/test.rs | 2 +- src/librustc/diagnostics.rs | 2 +- src/librustc/hir/mod.rs | 2 +- src/librustc/infer/error_reporting/mod.rs | 4 ++-- src/librustc/infer/outlives/obligations.rs | 2 +- src/librustc/infer/region_constraints/README.md | 2 +- src/librustc/middle/region.rs | 2 +- src/librustc/mir/interpret/mod.rs | 2 +- src/librustc/mir/mod.rs | 2 +- src/librustc/traits/coherence.rs | 2 +- src/librustc/traits/mod.rs | 2 +- src/librustc/ty/layout.rs | 4 ++-- src/librustc_apfloat/tests/ieee.rs | 4 ++-- src/librustc_borrowck/borrowck/mod.rs | 2 +- src/librustc_const_eval/_match.rs | 2 +- src/librustc_data_structures/indexed_vec.rs | 2 +- src/librustc_mir/borrow_check/mod.rs | 8 ++++---- src/librustc_mir/borrow_check/nll/mod.rs | 2 +- src/librustc_mir/borrow_check/nll/region_infer/mod.rs | 2 +- .../borrow_check/nll/region_infer/values.rs | 2 +- src/librustc_mir/build/matches/mod.rs | 2 +- src/librustc_mir/dataflow/impls/borrows.rs | 4 ++-- src/librustc_mir/diagnostics.rs | 2 +- src/librustc_mir/interpret/eval_context.rs | 2 +- src/librustc_mir/monomorphize/item.rs | 2 +- src/librustc_privacy/lib.rs | 2 +- src/librustc_resolve/check_unused.rs | 2 +- src/librustc_resolve/lib.rs | 2 +- src/librustc_resolve/resolve_imports.rs | 2 +- src/librustc_trans/back/lto.rs | 4 ++-- src/librustc_trans/builder.rs | 2 +- src/librustc_trans/mir/rvalue.rs | 2 +- src/librustc_trans_utils/trans_crate.rs | 2 +- src/libstd/io/buffered.rs | 2 +- src/libstd/sync/rwlock.rs | 4 ++-- src/libstd/sys_common/backtrace.rs | 2 +- src/libstd/sys_common/poison.rs | 2 +- src/libsyntax/ast.rs | 2 +- src/libsyntax/config.rs | 2 +- src/libsyntax/parse/parser.rs | 4 ++-- src/test/compile-fail/coerce-to-bang.rs | 2 +- .../macro_expanded_mod_helper/foo/bar.rs | 2 +- .../macro_expanded_mod_helper/foo/mod.rs | 2 +- src/test/compile-fail/hr-subtype.rs | 4 ++-- src/test/compile-fail/issue-20616-1.rs | 2 +- src/test/compile-fail/issue-20616-2.rs | 2 +- src/test/compile-fail/issue-20616-3.rs | 2 +- src/test/compile-fail/issue-20616-4.rs | 2 +- src/test/compile-fail/issue-20616-5.rs | 2 +- src/test/compile-fail/issue-20616-6.rs | 2 +- src/test/compile-fail/issue-20616-7.rs | 2 +- src/test/compile-fail/issue-20616-8.rs | 2 +- src/test/compile-fail/issue-20616-9.rs | 2 +- src/test/compile-fail/no_crate_type.rs | 2 +- src/test/mir-opt/README.md | 2 +- src/test/pretty/stmt_expr_attributes.rs | 2 +- src/test/run-make/hotplug_codegen_backend/Makefile | 2 +- .../run-make/hotplug_codegen_backend/the_backend.rs | 2 +- .../proc-macro/auxiliary/derive-reexport.rs | 2 +- src/test/run-pass/issue-29746.rs | 2 +- src/test/run-pass/issue-32008.rs | 2 +- src/test/run-pass/rfc1857-drop-order.rs | 18 +++++++++--------- src/test/run-pass/simd-target-feature-mixup.rs | 2 +- src/test/rustdoc/impl-parts-crosscrate.rs | 2 +- src/test/ui/explain.stdout | 2 +- .../issue-43106-gating-of-builtin-attrs.rs | 2 +- .../lifetime-errors/liveness-assign-imm-local-notes.rs | 2 +- 69 files changed, 89 insertions(+), 89 deletions(-) (limited to 'src/libstd/sync') diff --git a/RELEASES.md b/RELEASES.md index 7a9d256be28..64e2145e0f3 100644 --- a/RELEASES.md +++ b/RELEASES.md @@ -29,7 +29,7 @@ Libraries - [Copied `AsciiExt` methods onto `char`][46077] - [Remove `T: Sized` requirement on `ptr::is_null()`][46094] - [impl `From` for `{TryRecvError, RecvTimeoutError}`][45506] -- [Optimised `f32::{min, max}` to generate more efficent x86 assembly][47080] +- [Optimised `f32::{min, max}` to generate more efficient x86 assembly][47080] - [`[u8]::contains` now uses memchr which provides a 3x speed improvement][46713] Stabilized APIs diff --git a/config.toml.example b/config.toml.example index f153562a538..8d1fa3eec5c 100644 --- a/config.toml.example +++ b/config.toml.example @@ -151,8 +151,8 @@ # default. #extended = false -# Installs choosen set of extended tools if enables. By default builds all. -# If choosen tool failed to build the installation fails. +# Installs chosen set of extended tools if enables. By default builds all. +# If chosen tool failed to build the installation fails. #tools = ["cargo", "rls", "rustfmt", "analysis", "src"] # Verbosity level: 0 == not verbose, 1 == verbose, 2 == very verbose diff --git a/src/bootstrap/test.rs b/src/bootstrap/test.rs index 64ede4f4ecc..7b485662760 100644 --- a/src/bootstrap/test.rs +++ b/src/bootstrap/test.rs @@ -935,7 +935,7 @@ impl Step for Compiletest { } } if suite == "run-make" && !build.config.llvm_enabled { - println!("Ignoring run-make test suite as they generally dont work without LLVM"); + println!("Ignoring run-make test suite as they generally don't work without LLVM"); return; } diff --git a/src/librustc/diagnostics.rs b/src/librustc/diagnostics.rs index 4c256556191..287516474d4 100644 --- a/src/librustc/diagnostics.rs +++ b/src/librustc/diagnostics.rs @@ -1891,7 +1891,7 @@ is a function pointer, which is not zero-sized. This pattern should be rewritten. There are a few possible ways to do this: - change the original fn declaration to match the expected signature, - and do the cast in the fn body (the prefered option) + and do the cast in the fn body (the preferred option) - cast the fn item fo a fn pointer before calling transmute, as shown here: ``` diff --git a/src/librustc/hir/mod.rs b/src/librustc/hir/mod.rs index 2854b9da147..bc03f7ead81 100644 --- a/src/librustc/hir/mod.rs +++ b/src/librustc/hir/mod.rs @@ -543,7 +543,7 @@ impl Generics { } /// Synthetic Type Parameters are converted to an other form during lowering, this allows -/// to track the original form they had. Usefull for error messages. +/// to track the original form they had. Useful for error messages. #[derive(Copy, Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug)] pub enum SyntheticTyParamKind { ImplTrait diff --git a/src/librustc/infer/error_reporting/mod.rs b/src/librustc/infer/error_reporting/mod.rs index 03fc40b2e39..700d06acf11 100644 --- a/src/librustc/infer/error_reporting/mod.rs +++ b/src/librustc/infer/error_reporting/mod.rs @@ -734,7 +734,7 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> { } } - // When finding T != &T, hightlight only the borrow + // When finding T != &T, highlight only the borrow (&ty::TyRef(r1, ref tnm1), _) if equals(&tnm1.ty, &t2) => { let mut values = (DiagnosticStyledString::new(), DiagnosticStyledString::new()); push_ty_ref(&r1, tnm1, &mut values.0); @@ -946,7 +946,7 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> { let type_param = generics.type_param(param, self.tcx); let hir = &self.tcx.hir; hir.as_local_node_id(type_param.def_id).map(|id| { - // Get the `hir::TyParam` to verify wether it already has any bounds. + // Get the `hir::TyParam` to verify whether it already has any bounds. // We do this to avoid suggesting code that ends up as `T: 'a'b`, // instead we suggest `T: 'a + 'b` in that case. let has_lifetimes = if let hir_map::NodeTyParam(ref p) = hir.get(id) { diff --git a/src/librustc/infer/outlives/obligations.rs b/src/librustc/infer/outlives/obligations.rs index eda2e1f7b4e..36e657f78b4 100644 --- a/src/librustc/infer/outlives/obligations.rs +++ b/src/librustc/infer/outlives/obligations.rs @@ -106,7 +106,7 @@ impl<'cx, 'gcx, 'tcx> InferCtxt<'cx, 'gcx, 'tcx> { /// done (or else an assert will fire). /// /// See the `region_obligations` field of `InferCtxt` for some - /// comments about how this funtion fits into the overall expected + /// comments about how this function fits into the overall expected /// flow of the the inferencer. The key point is that it is /// invoked after all type-inference variables have been bound -- /// towards the end of regionck. This also ensures that the diff --git a/src/librustc/infer/region_constraints/README.md b/src/librustc/infer/region_constraints/README.md index 67ad08c7530..95f9c8c8353 100644 --- a/src/librustc/infer/region_constraints/README.md +++ b/src/librustc/infer/region_constraints/README.md @@ -19,7 +19,7 @@ The constraints are always of one of three possible forms: a subregion of Rj - `ConstrainRegSubVar(R, Ri)` states that the concrete region R (which must not be a variable) must be a subregion of the variable Ri -- `ConstrainVarSubReg(Ri, R)` states the variable Ri shoudl be less +- `ConstrainVarSubReg(Ri, R)` states the variable Ri should be less than the concrete region R. This is kind of deprecated and ought to be replaced with a verify (they essentially play the same role). diff --git a/src/librustc/middle/region.rs b/src/librustc/middle/region.rs index e5619f469e7..3ce4ab04777 100644 --- a/src/librustc/middle/region.rs +++ b/src/librustc/middle/region.rs @@ -886,7 +886,7 @@ fn resolve_block<'a, 'tcx>(visitor: &mut RegionResolutionVisitor<'a, 'tcx>, blk: // // Each of the statements within the block is a terminating // scope, and thus a temporary (e.g. the result of calling - // `bar()` in the initalizer expression for `let inner = ...;`) + // `bar()` in the initializer expression for `let inner = ...;`) // will be cleaned up immediately after its corresponding // statement (i.e. `let inner = ...;`) executes. // diff --git a/src/librustc/mir/interpret/mod.rs b/src/librustc/mir/interpret/mod.rs index 8ffea62f6be..a80695ec9b9 100644 --- a/src/librustc/mir/interpret/mod.rs +++ b/src/librustc/mir/interpret/mod.rs @@ -56,7 +56,7 @@ pub struct GlobalId<'tcx> { //////////////////////////////////////////////////////////////////////////////// pub trait PointerArithmetic: layout::HasDataLayout { - // These are not supposed to be overriden. + // These are not supposed to be overridden. //// Trunace the given value to the pointer size; also return whether there was an overflow fn truncate_to_ptr(self, val: u128) -> (u64, bool) { diff --git a/src/librustc/mir/mod.rs b/src/librustc/mir/mod.rs index 439be667861..b88dea871ce 100644 --- a/src/librustc/mir/mod.rs +++ b/src/librustc/mir/mod.rs @@ -1950,7 +1950,7 @@ pub struct GeneratorLayout<'tcx> { /// ``` /// /// here, there is one unique free region (`'a`) but it appears -/// twice. We would "renumber" each occurence to a unique vid, as follows: +/// twice. We would "renumber" each occurrence to a unique vid, as follows: /// /// ```text /// ClosureSubsts = [ diff --git a/src/librustc/traits/coherence.rs b/src/librustc/traits/coherence.rs index 9de18612d81..7311b47974a 100644 --- a/src/librustc/traits/coherence.rs +++ b/src/librustc/traits/coherence.rs @@ -277,7 +277,7 @@ pub fn orphan_check<'a, 'gcx, 'tcx>(tcx: TyCtxt<'a, 'gcx, 'tcx>, /// is bad, because the only local type with `T` as a subtree is /// `LocalType`, and `Vec<->` is between it and the type parameter. /// - similarly, `FundamentalPair, T>` is bad, because -/// the second occurence of `T` is not a subtree of *any* local type. +/// the second occurrence of `T` is not a subtree of *any* local type. /// - however, `LocalType>` is OK, because `T` is a subtree of /// `LocalType>`, which is local and has no types between it and /// the type parameter. diff --git a/src/librustc/traits/mod.rs b/src/librustc/traits/mod.rs index 80819a86b7c..41cc8ca601a 100644 --- a/src/librustc/traits/mod.rs +++ b/src/librustc/traits/mod.rs @@ -621,7 +621,7 @@ pub fn fully_normalize<'a, 'gcx, 'tcx, T>(infcx: &InferCtxt<'a, 'gcx, 'tcx>, // FIXME (@jroesch) ISSUE 26721 // I'm not sure if this is a bug or not, needs further investigation. // It appears that by reusing the fulfillment_cx here we incur more - // obligations and later trip an asssertion on regionck.rs line 337. + // obligations and later trip an assertion on regionck.rs line 337. // // The two possibilities I see is: // - normalization is not actually fully happening and we diff --git a/src/librustc/ty/layout.rs b/src/librustc/ty/layout.rs index 63b91ff1101..c3cd65230bd 100644 --- a/src/librustc/ty/layout.rs +++ b/src/librustc/ty/layout.rs @@ -2059,7 +2059,7 @@ impl<'a, 'tcx> LayoutOf> for LayoutCx<'tcx, TyCtxt<'a, 'tcx, 'tcx>> { // can however trigger recursive invocations of `layout_of`. // Therefore, we execute it *after* the main query has // completed, to avoid problems around recursive structures - // and the like. (Admitedly, I wasn't able to reproduce a problem + // and the like. (Admittedly, I wasn't able to reproduce a problem // here, but it seems like the right thing to do. -nmatsakis) self.record_layout_for_printing(layout); @@ -2085,7 +2085,7 @@ impl<'a, 'tcx> LayoutOf> for LayoutCx<'tcx, ty::maps::TyCtxtAt<'a, 'tcx // can however trigger recursive invocations of `layout_of`. // Therefore, we execute it *after* the main query has // completed, to avoid problems around recursive structures - // and the like. (Admitedly, I wasn't able to reproduce a problem + // and the like. (Admittedly, I wasn't able to reproduce a problem // here, but it seems like the right thing to do. -nmatsakis) let cx = LayoutCx { tcx: *self.tcx, diff --git a/src/librustc_apfloat/tests/ieee.rs b/src/librustc_apfloat/tests/ieee.rs index aff2076e038..ff46ee79c31 100644 --- a/src/librustc_apfloat/tests/ieee.rs +++ b/src/librustc_apfloat/tests/ieee.rs @@ -2201,12 +2201,12 @@ fn is_finite_non_zero() { assert!(!Single::ZERO.is_finite_non_zero()); assert!(!(-Single::ZERO).is_finite_non_zero()); - // Test +/- qNaN. +/- dont mean anything with qNaN but paranoia can't hurt in + // Test +/- qNaN. +/- don't mean anything with qNaN but paranoia can't hurt in // this instance. assert!(!Single::NAN.is_finite_non_zero()); assert!(!(-Single::NAN).is_finite_non_zero()); - // Test +/- sNaN. +/- dont mean anything with sNaN but paranoia can't hurt in + // Test +/- sNaN. +/- don't mean anything with sNaN but paranoia can't hurt in // this instance. assert!(!Single::snan(None).is_finite_non_zero()); assert!(!(-Single::snan(None)).is_finite_non_zero()); diff --git a/src/librustc_borrowck/borrowck/mod.rs b/src/librustc_borrowck/borrowck/mod.rs index 738c0d82ee1..58818d0ce80 100644 --- a/src/librustc_borrowck/borrowck/mod.rs +++ b/src/librustc_borrowck/borrowck/mod.rs @@ -1111,7 +1111,7 @@ impl<'a, 'tcx> BorrowckCtxt<'a, 'tcx> { /// Given a type, if it is an immutable reference, return a suggestion to make it mutable fn suggest_mut_for_immutable(&self, pty: &hir::Ty, is_implicit_self: bool) -> Option { - // Check wether the argument is an immutable reference + // Check whether the argument is an immutable reference debug!("suggest_mut_for_immutable({:?}, {:?})", pty, is_implicit_self); if let hir::TyRptr(lifetime, hir::MutTy { mutbl: hir::Mutability::MutImmutable, diff --git a/src/librustc_const_eval/_match.rs b/src/librustc_const_eval/_match.rs index a7c382eba50..e30f5cb4f12 100644 --- a/src/librustc_const_eval/_match.rs +++ b/src/librustc_const_eval/_match.rs @@ -607,7 +607,7 @@ pub fn is_useful<'p, 'a: 'p, 'tcx: 'a>(cx: &mut MatchCheckCtxt<'a, 'tcx>, // be able to observe whether the types of the struct's fields are // inhabited. // - // If the field is truely inaccessible, then all the patterns + // If the field is truly inaccessible, then all the patterns // matching against it must be wildcard patterns, so its type // does not matter. // diff --git a/src/librustc_data_structures/indexed_vec.rs b/src/librustc_data_structures/indexed_vec.rs index 753f12f400b..b11ca107af7 100644 --- a/src/librustc_data_structures/indexed_vec.rs +++ b/src/librustc_data_structures/indexed_vec.rs @@ -204,7 +204,7 @@ macro_rules! newtype_index { $($tokens)*); ); - // The case where no derives are added, but encodable is overriden. Don't + // The case where no derives are added, but encodable is overridden. Don't // derive serialization traits (@pub [$($pub:tt)*] @type [$type:ident] diff --git a/src/librustc_mir/borrow_check/mod.rs b/src/librustc_mir/borrow_check/mod.rs index 650f99828ae..c6ed971f767 100644 --- a/src/librustc_mir/borrow_check/mod.rs +++ b/src/librustc_mir/borrow_check/mod.rs @@ -117,7 +117,7 @@ fn do_mir_borrowck<'a, 'gcx, 'tcx>( for move_error in move_errors { let (span, kind): (Span, IllegalMoveOriginKind) = match move_error { MoveError::UnionMove { .. } => { - unimplemented!("dont know how to report union move errors yet.") + unimplemented!("don't know how to report union move errors yet.") } MoveError::IllegalMove { cannot_move_out_of: o, @@ -1424,7 +1424,7 @@ impl<'cx, 'gcx, 'tcx> MirBorrowckCtxt<'cx, 'gcx, 'tcx> { /// tracked in the MoveData. /// /// An Err result includes a tag indicated why the search failed. - /// Currenly this can only occur if the place is built off of a + /// Currently this can only occur if the place is built off of a /// static variable, as we do not track those in the MoveData. fn move_path_closest_to( &mut self, @@ -1439,7 +1439,7 @@ impl<'cx, 'gcx, 'tcx> MirBorrowckCtxt<'cx, 'gcx, 'tcx> { } match *last_prefix { Place::Local(_) => panic!("should have move path for every Local"), - Place::Projection(_) => panic!("PrefixSet::All meant dont stop for Projection"), + Place::Projection(_) => panic!("PrefixSet::All meant don't stop for Projection"), Place::Static(_) => return Err(NoMovePathFound::ReachedStatic), } } @@ -1484,7 +1484,7 @@ impl<'cx, 'gcx, 'tcx> MirBorrowckCtxt<'cx, 'gcx, 'tcx> { { } ProjectionElem::Subslice { .. } => { - panic!("we dont allow assignments to subslices, context: {:?}", + panic!("we don't allow assignments to subslices, context: {:?}", context); } diff --git a/src/librustc_mir/borrow_check/nll/mod.rs b/src/librustc_mir/borrow_check/nll/mod.rs index 66ca74b0139..07e5091da9c 100644 --- a/src/librustc_mir/borrow_check/nll/mod.rs +++ b/src/librustc_mir/borrow_check/nll/mod.rs @@ -278,7 +278,7 @@ fn for_each_region_constraint( /// Right now, we piggy back on the `ReVar` to store our NLL inference /// regions. These are indexed with `RegionVid`. This method will -/// assert that the region is a `ReVar` and extract its interal index. +/// assert that the region is a `ReVar` and extract its internal index. /// This is reasonable because in our MIR we replace all universal regions /// with inference variables. pub trait ToRegionVid { diff --git a/src/librustc_mir/borrow_check/nll/region_infer/mod.rs b/src/librustc_mir/borrow_check/nll/region_infer/mod.rs index 9a338947f47..33c012dfad8 100644 --- a/src/librustc_mir/borrow_check/nll/region_infer/mod.rs +++ b/src/librustc_mir/borrow_check/nll/region_infer/mod.rs @@ -964,7 +964,7 @@ impl<'tcx> RegionInferenceContext<'tcx> { debug!("check_universal_region: fr_minus={:?}", fr_minus); // Grow `shorter_fr` until we find a non-local - // regon. (We always will.) We'll call that + // region. (We always will.) We'll call that // `shorter_fr+` -- it's ever so slightly larger than // `fr`. let shorter_fr_plus = self.universal_regions.non_local_upper_bound(shorter_fr); diff --git a/src/librustc_mir/borrow_check/nll/region_infer/values.rs b/src/librustc_mir/borrow_check/nll/region_infer/values.rs index b2b2ca1182d..45236bbc4aa 100644 --- a/src/librustc_mir/borrow_check/nll/region_infer/values.rs +++ b/src/librustc_mir/borrow_check/nll/region_infer/values.rs @@ -150,7 +150,7 @@ pub(super) enum RegionElement { /// A point in the control-flow graph. Location(Location), - /// An in-scope, universally quantified region (e.g., a liftime parameter). + /// An in-scope, universally quantified region (e.g., a lifetime parameter). UniversalRegion(RegionVid), } diff --git a/src/librustc_mir/build/matches/mod.rs b/src/librustc_mir/build/matches/mod.rs index 8053a0a6948..58ce572ae8d 100644 --- a/src/librustc_mir/build/matches/mod.rs +++ b/src/librustc_mir/build/matches/mod.rs @@ -8,7 +8,7 @@ // option. This file may not be copied, modified, or distributed // except according to those terms. -//! Code related to match expresions. These are sufficiently complex +//! Code related to match expressions. These are sufficiently complex //! to warrant their own module and submodules. :) This main module //! includes the high-level algorithm, the submodules contain the //! details. diff --git a/src/librustc_mir/dataflow/impls/borrows.rs b/src/librustc_mir/dataflow/impls/borrows.rs index e798cc93cb0..8ab4035cf4a 100644 --- a/src/librustc_mir/dataflow/impls/borrows.rs +++ b/src/librustc_mir/dataflow/impls/borrows.rs @@ -80,14 +80,14 @@ pub struct Borrows<'a, 'gcx: 'tcx, 'tcx: 'a> { /// tracking (phased) borrows. It computes where a borrow is reserved; /// i.e. where it can reach in the control flow starting from its /// initial `assigned = &'rgn borrowed` statement, and ending -/// whereever `'rgn` itself ends. +/// wherever `'rgn` itself ends. pub(crate) struct Reservations<'a, 'gcx: 'tcx, 'tcx: 'a>(pub(crate) Borrows<'a, 'gcx, 'tcx>); /// The `ActiveBorrows` analysis is the second of the two flow /// analyses tracking (phased) borrows. It computes where any given /// borrow `&assigned = &'rgn borrowed` is *active*, which starts at /// the first use of `assigned` after the reservation has started, and -/// ends whereever `'rgn` itself ends. +/// ends wherever `'rgn` itself ends. pub(crate) struct ActiveBorrows<'a, 'gcx: 'tcx, 'tcx: 'a>(pub(crate) Borrows<'a, 'gcx, 'tcx>); impl<'a, 'gcx, 'tcx> Reservations<'a, 'gcx, 'tcx> { diff --git a/src/librustc_mir/diagnostics.rs b/src/librustc_mir/diagnostics.rs index 619c0dc847e..3491faf9cda 100644 --- a/src/librustc_mir/diagnostics.rs +++ b/src/librustc_mir/diagnostics.rs @@ -365,7 +365,7 @@ with `#[derive(Clone)]`. Some types have no ownership semantics at all and are trivial to duplicate. An example is `i32` and the other number types. We don't have to call `.clone()` to clone them, because they are marked `Copy` in addition to `Clone`. Implicit -cloning is more convienient in this case. We can mark our own types `Copy` if +cloning is more convenient in this case. We can mark our own types `Copy` if all their members also are marked `Copy`. In the example below, we implement a `Point` type. Because it only stores two diff --git a/src/librustc_mir/interpret/eval_context.rs b/src/librustc_mir/interpret/eval_context.rs index 52b87282180..3578164feb7 100644 --- a/src/librustc_mir/interpret/eval_context.rs +++ b/src/librustc_mir/interpret/eval_context.rs @@ -84,7 +84,7 @@ pub struct Frame<'tcx> { /// return). pub block: mir::BasicBlock, - /// The index of the currently evaluated statment. + /// The index of the currently evaluated statement. pub stmt: usize, } diff --git a/src/librustc_mir/monomorphize/item.rs b/src/librustc_mir/monomorphize/item.rs index 86a4dd4a31f..a5078187a57 100644 --- a/src/librustc_mir/monomorphize/item.rs +++ b/src/librustc_mir/monomorphize/item.rs @@ -68,7 +68,7 @@ pub enum InstantiationMode { /// however, our local copy may conflict with other crates also /// inlining the same function. /// - /// This flag indicates that this situation is occuring, and informs + /// This flag indicates that this situation is occurring, and informs /// symbol name calculation that some extra mangling is needed to /// avoid conflicts. Note that this may eventually go away entirely if /// ThinLTO enables us to *always* have a globally shared instance of a diff --git a/src/librustc_privacy/lib.rs b/src/librustc_privacy/lib.rs index b46882f054d..6ae04760953 100644 --- a/src/librustc_privacy/lib.rs +++ b/src/librustc_privacy/lib.rs @@ -781,7 +781,7 @@ impl<'a, 'tcx> Visitor<'tcx> for TypePrivacyVisitor<'a, 'tcx> { // Additionally, until better reachability analysis for macros 2.0 is available, // we prohibit access to private statics from other crates, this allows to give // more code internal visibility at link time. (Access to private functions - // is already prohibited by type privacy for funciton types.) + // is already prohibited by type privacy for function types.) fn visit_qpath(&mut self, qpath: &'tcx hir::QPath, id: ast::NodeId, span: Span) { let def = match *qpath { hir::QPath::Resolved(_, ref path) => match path.def { diff --git a/src/librustc_resolve/check_unused.rs b/src/librustc_resolve/check_unused.rs index 5a321053b7a..a757ac92df5 100644 --- a/src/librustc_resolve/check_unused.rs +++ b/src/librustc_resolve/check_unused.rs @@ -17,7 +17,7 @@ // `use` directives. // // Unused trait imports can't be checked until the method resolution. We save -// candidates here, and do the acutal check in librustc_typeck/check_unused.rs. +// candidates here, and do the actual check in librustc_typeck/check_unused.rs. use std::ops::{Deref, DerefMut}; diff --git a/src/librustc_resolve/lib.rs b/src/librustc_resolve/lib.rs index 2da4bfedd3a..d8e03552a6a 100644 --- a/src/librustc_resolve/lib.rs +++ b/src/librustc_resolve/lib.rs @@ -1440,7 +1440,7 @@ impl<'a> Resolver<'a> { /// Rustdoc uses this to resolve things in a recoverable way. ResolutionError<'a> /// isn't something that can be returned because it can't be made to live that long, /// and also it's a private type. Fortunately rustdoc doesn't need to know the error, - /// just that an error occured. + /// just that an error occurred. pub fn resolve_str_path_error(&mut self, span: Span, path_str: &str, is_value: bool) -> Result { use std::iter; diff --git a/src/librustc_resolve/resolve_imports.rs b/src/librustc_resolve/resolve_imports.rs index a8070c553bd..438ab3a3513 100644 --- a/src/librustc_resolve/resolve_imports.rs +++ b/src/librustc_resolve/resolve_imports.rs @@ -186,7 +186,7 @@ impl<'a> Resolver<'a> { } let check_usable = |this: &mut Self, binding: &'a NameBinding<'a>| { - // `extern crate` are always usable for backwards compatability, see issue #37020. + // `extern crate` are always usable for backwards compatibility, see issue #37020. let usable = this.is_accessible(binding.vis) || binding.is_extern_crate(); if usable { Ok(binding) } else { Err(Determined) } }; diff --git a/src/librustc_trans/back/lto.rs b/src/librustc_trans/back/lto.rs index a3327038019..ab354a30d41 100644 --- a/src/librustc_trans/back/lto.rs +++ b/src/librustc_trans/back/lto.rs @@ -84,7 +84,7 @@ impl LtoModuleTranslation { } } - /// A "guage" of how costly it is to optimize this module, used to sort + /// A "gauge" of how costly it is to optimize this module, used to sort /// biggest modules first. pub fn cost(&self) -> u64 { match *self { @@ -726,7 +726,7 @@ impl ThinModule { // which was basically a resurgence of #45511 after LLVM's bug 35212 was // fixed. // - // This function below is a huge hack around tihs problem. The function + // This function below is a huge hack around this problem. The function // below is defined in `PassWrapper.cpp` and will basically "merge" // all `DICompileUnit` instances in a module. Basically it'll take all // the objects, rewrite all pointers of `DISubprogram` to point to the diff --git a/src/librustc_trans/builder.rs b/src/librustc_trans/builder.rs index 5ab8d03b8c7..d4e05a18e3a 100644 --- a/src/librustc_trans/builder.rs +++ b/src/librustc_trans/builder.rs @@ -1240,7 +1240,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { /// on), and `ptr` is nonzero-sized, then extracts the size of `ptr` /// and the intrinsic for `lt` and passes them to `emit`, which is in /// charge of generating code to call the passed intrinsic on whatever - /// block of generated code is targetted for the intrinsic. + /// block of generated code is targeted for the intrinsic. /// /// If LLVM lifetime intrinsic support is disabled (i.e. optimizations /// off) or `ptr` is zero-sized, then no-op (does not call `emit`). diff --git a/src/librustc_trans/mir/rvalue.rs b/src/librustc_trans/mir/rvalue.rs index 2e876ec118d..34ac44cec02 100644 --- a/src/librustc_trans/mir/rvalue.rs +++ b/src/librustc_trans/mir/rvalue.rs @@ -844,7 +844,7 @@ fn cast_float_to_int(bx: &Builder, // They are exactly equal to int_ty::{MIN,MAX} if float_ty has enough significand bits. // Otherwise, int_ty::MAX must be rounded towards zero, as it is one less than a power of two. // int_ty::MIN, however, is either zero or a negative power of two and is thus exactly - // representable. Note that this only works if float_ty's exponent range is sufficently large. + // representable. Note that this only works if float_ty's exponent range is sufficiently large. // f16 or 256 bit integers would break this property. Right now the smallest float type is f32 // with exponents ranging up to 127, which is barely enough for i128::MIN = -2^127. // On the other hand, f_max works even if int_ty::MAX is greater than float_ty::MAX. Because diff --git a/src/librustc_trans_utils/trans_crate.rs b/src/librustc_trans_utils/trans_crate.rs index e14abdff339..9943a9bd398 100644 --- a/src/librustc_trans_utils/trans_crate.rs +++ b/src/librustc_trans_utils/trans_crate.rs @@ -151,7 +151,7 @@ impl MetadataLoader for NoLlvmMetadataLoader { } } - Err("Couldnt find metadata section".to_string()) + Err("Couldn't find metadata section".to_string()) } fn get_dylib_metadata( diff --git a/src/libstd/io/buffered.rs b/src/libstd/io/buffered.rs index 4e7db5f0826..9250c1c437b 100644 --- a/src/libstd/io/buffered.rs +++ b/src/libstd/io/buffered.rs @@ -293,7 +293,7 @@ impl Seek for BufReader { /// where `n` minus the internal buffer length overflows an `i64`, two /// seeks will be performed instead of one. If the second seek returns /// `Err`, the underlying reader will be left at the same position it would - /// have if you seeked to `SeekFrom::Current(0)`. + /// have if you called `seek` with `SeekFrom::Current(0)`. /// /// [`seek_relative`]: #method.seek_relative fn seek(&mut self, pos: SeekFrom) -> io::Result { diff --git a/src/libstd/sync/rwlock.rs b/src/libstd/sync/rwlock.rs index 2edf02efc47..f7fdedc0d21 100644 --- a/src/libstd/sync/rwlock.rs +++ b/src/libstd/sync/rwlock.rs @@ -24,8 +24,8 @@ use sys_common::rwlock as sys; /// typically allows for read-only access (shared access). /// /// In comparison, a [`Mutex`] does not distinguish between readers or writers -/// that aquire the lock, therefore blocking any threads waiting for the lock to -/// become available. An `RwLock` will allow any number of readers to aquire the +/// that acquire the lock, therefore blocking any threads waiting for the lock to +/// become available. An `RwLock` will allow any number of readers to acquire the /// lock as long as a writer is not holding the lock. /// /// The priority policy of the lock is dependent on the underlying operating diff --git a/src/libstd/sys_common/backtrace.rs b/src/libstd/sys_common/backtrace.rs index a364a0392b3..1955f3ec9a2 100644 --- a/src/libstd/sys_common/backtrace.rs +++ b/src/libstd/sys_common/backtrace.rs @@ -136,7 +136,7 @@ pub fn __rust_begin_short_backtrace(f: F) -> T f() } -/// Controls how the backtrace should be formated. +/// Controls how the backtrace should be formatted. #[derive(Debug, Copy, Clone, Eq, PartialEq)] pub enum PrintFormat { /// Show all the frames with absolute path for files. diff --git a/src/libstd/sys_common/poison.rs b/src/libstd/sys_common/poison.rs index 934ac3edbf1..e74c40ae04b 100644 --- a/src/libstd/sys_common/poison.rs +++ b/src/libstd/sys_common/poison.rs @@ -98,7 +98,7 @@ pub struct PoisonError { } /// An enumeration of possible errors associated with a [`TryLockResult`] which -/// can occur while trying to aquire a lock, from the [`try_lock`] method on a +/// can occur while trying to acquire a lock, from the [`try_lock`] method on a /// [`Mutex`] or the [`try_read`] and [`try_write`] methods on an [`RwLock`]. /// /// [`Mutex`]: struct.Mutex.html diff --git a/src/libsyntax/ast.rs b/src/libsyntax/ast.rs index c7ab6158256..8c1e5cf7586 100644 --- a/src/libsyntax/ast.rs +++ b/src/libsyntax/ast.rs @@ -918,7 +918,7 @@ pub struct Expr { } impl Expr { - /// Wether this expression would be valid somewhere that expects a value, for example, an `if` + /// Whether this expression would be valid somewhere that expects a value, for example, an `if` /// condition. pub fn returns(&self) -> bool { if let ExprKind::Block(ref block) = self.node { diff --git a/src/libsyntax/config.rs b/src/libsyntax/config.rs index fc82357455b..aa360ed1bf5 100644 --- a/src/libsyntax/config.rs +++ b/src/libsyntax/config.rs @@ -114,7 +114,7 @@ impl<'a> StripUnconfigured<'a> { } } - // Determine if a node with the given attributes should be included in this configuation. + // Determine if a node with the given attributes should be included in this configuration. pub fn in_cfg(&mut self, attrs: &[ast::Attribute]) -> bool { attrs.iter().all(|attr| { // When not compiling with --test we should not compile the #[test] functions diff --git a/src/libsyntax/parse/parser.rs b/src/libsyntax/parse/parser.rs index ac582627f88..7915109ce3a 100644 --- a/src/libsyntax/parse/parser.rs +++ b/src/libsyntax/parse/parser.rs @@ -3912,7 +3912,7 @@ impl<'a> Parser<'a> { "use `=` if you meant to assign", "=".to_string()); err.emit(); - // As this was parsed successfuly, continue as if the code has been fixed for the + // As this was parsed successfully, continue as if the code has been fixed for the // rest of the file. It will still fail due to the emitted error, but we avoid // extra noise. init @@ -6571,7 +6571,7 @@ impl<'a> Parser<'a> { return Ok(Some(macro_def)); } - // Verify wether we have encountered a struct or method definition where the user forgot to + // Verify whether we have encountered a struct or method definition where the user forgot to // add the `struct` or `fn` keyword after writing `pub`: `pub S {}` if visibility == Visibility::Public && self.check_ident() && diff --git a/src/test/compile-fail/coerce-to-bang.rs b/src/test/compile-fail/coerce-to-bang.rs index 2cf568777d4..b804bb2981b 100644 --- a/src/test/compile-fail/coerce-to-bang.rs +++ b/src/test/compile-fail/coerce-to-bang.rs @@ -14,7 +14,7 @@ fn foo(x: usize, y: !, z: usize) { } fn call_foo_a() { - // FIXME(#40800) -- accepted beacuse divergence happens **before** + // FIXME(#40800) -- accepted because divergence happens **before** // the coercion to `!`, but within same expression. Not clear that // these are the rules we want. foo(return, 22, 44); diff --git a/src/test/compile-fail/directory_ownership/macro_expanded_mod_helper/foo/bar.rs b/src/test/compile-fail/directory_ownership/macro_expanded_mod_helper/foo/bar.rs index 9177dcba0d7..4ef92981314 100644 --- a/src/test/compile-fail/directory_ownership/macro_expanded_mod_helper/foo/bar.rs +++ b/src/test/compile-fail/directory_ownership/macro_expanded_mod_helper/foo/bar.rs @@ -8,4 +8,4 @@ // option. This file may not be copied, modified, or distributed // except according to those terms. -// ignore-test not a test, auxillary +// ignore-test not a test, auxiliary diff --git a/src/test/compile-fail/directory_ownership/macro_expanded_mod_helper/foo/mod.rs b/src/test/compile-fail/directory_ownership/macro_expanded_mod_helper/foo/mod.rs index e29c985b983..41a8c288e7c 100644 --- a/src/test/compile-fail/directory_ownership/macro_expanded_mod_helper/foo/mod.rs +++ b/src/test/compile-fail/directory_ownership/macro_expanded_mod_helper/foo/mod.rs @@ -8,6 +8,6 @@ // option. This file may not be copied, modified, or distributed // except according to those terms. -// ignore-test not a test, auxillary +// ignore-test not a test, auxiliary mod_decl!(bar); diff --git a/src/test/compile-fail/hr-subtype.rs b/src/test/compile-fail/hr-subtype.rs index c88d74d53ce..86df2382732 100644 --- a/src/test/compile-fail/hr-subtype.rs +++ b/src/test/compile-fail/hr-subtype.rs @@ -84,7 +84,7 @@ check! { free_inv_x_vs_free_inv_y: (fn(Inv<'x>), fn(Inv<'y>)) } // Somewhat surprisingly, a fn taking two distinct bound lifetimes and -// a fn taking one bound lifetime can be interchangable, but only if +// a fn taking one bound lifetime can be interchangeable, but only if // we are co- or contra-variant with respect to both lifetimes. // // The reason is: @@ -100,7 +100,7 @@ check! { bound_contra_a_contra_b_ret_co_a: (for<'a,'b> fn(Contra<'a>, Contra<'b> check! { bound_co_a_co_b_ret_contra_a: (for<'a,'b> fn(Co<'a>, Co<'b>) -> Contra<'a>, for<'a> fn(Co<'a>, Co<'a>) -> Contra<'a>) } -// If we make those lifetimes invariant, then the two types are not interchangable. +// If we make those lifetimes invariant, then the two types are not interchangeable. check! { bound_inv_a_b_vs_bound_inv_a: (for<'a,'b> fn(Inv<'a>, Inv<'b>), for<'a> fn(Inv<'a>, Inv<'a>)) } check! { bound_a_b_ret_a_vs_bound_a_ret_a: (for<'a,'b> fn(&'a u32, &'b u32) -> &'a u32, diff --git a/src/test/compile-fail/issue-20616-1.rs b/src/test/compile-fail/issue-20616-1.rs index a1949df661a..3e29383d62c 100644 --- a/src/test/compile-fail/issue-20616-1.rs +++ b/src/test/compile-fail/issue-20616-1.rs @@ -9,7 +9,7 @@ // except according to those terms. // We need all these 9 issue-20616-N.rs files -// becase we can only catch one parsing error at a time +// because we can only catch one parsing error at a time diff --git a/src/test/compile-fail/issue-20616-2.rs b/src/test/compile-fail/issue-20616-2.rs index 87b836d6872..1ec7a74559a 100644 --- a/src/test/compile-fail/issue-20616-2.rs +++ b/src/test/compile-fail/issue-20616-2.rs @@ -9,7 +9,7 @@ // except according to those terms. // We need all these 9 issue-20616-N.rs files -// becase we can only catch one parsing error at a time +// because we can only catch one parsing error at a time diff --git a/src/test/compile-fail/issue-20616-3.rs b/src/test/compile-fail/issue-20616-3.rs index e5ed46d2cb3..885fd246547 100644 --- a/src/test/compile-fail/issue-20616-3.rs +++ b/src/test/compile-fail/issue-20616-3.rs @@ -9,7 +9,7 @@ // except according to those terms. // We need all these 9 issue-20616-N.rs files -// becase we can only catch one parsing error at a time +// because we can only catch one parsing error at a time diff --git a/src/test/compile-fail/issue-20616-4.rs b/src/test/compile-fail/issue-20616-4.rs index 9b731289e13..0dbe92fc1bc 100644 --- a/src/test/compile-fail/issue-20616-4.rs +++ b/src/test/compile-fail/issue-20616-4.rs @@ -9,7 +9,7 @@ // except according to those terms. // We need all these 9 issue-20616-N.rs files -// becase we can only catch one parsing error at a time +// because we can only catch one parsing error at a time diff --git a/src/test/compile-fail/issue-20616-5.rs b/src/test/compile-fail/issue-20616-5.rs index 5e3b024da9a..794e5178f4b 100644 --- a/src/test/compile-fail/issue-20616-5.rs +++ b/src/test/compile-fail/issue-20616-5.rs @@ -9,7 +9,7 @@ // except according to those terms. // We need all these 9 issue-20616-N.rs files -// becase we can only catch one parsing error at a time +// because we can only catch one parsing error at a time diff --git a/src/test/compile-fail/issue-20616-6.rs b/src/test/compile-fail/issue-20616-6.rs index b6ee26f9f62..fe91751a4a0 100644 --- a/src/test/compile-fail/issue-20616-6.rs +++ b/src/test/compile-fail/issue-20616-6.rs @@ -9,7 +9,7 @@ // except according to those terms. // We need all these 9 issue-20616-N.rs files -// becase we can only catch one parsing error at a time +// because we can only catch one parsing error at a time diff --git a/src/test/compile-fail/issue-20616-7.rs b/src/test/compile-fail/issue-20616-7.rs index fef3dd4e31d..184ad027102 100644 --- a/src/test/compile-fail/issue-20616-7.rs +++ b/src/test/compile-fail/issue-20616-7.rs @@ -9,7 +9,7 @@ // except according to those terms. // We need all these 9 issue-20616-N.rs files -// becase we can only catch one parsing error at a time +// because we can only catch one parsing error at a time diff --git a/src/test/compile-fail/issue-20616-8.rs b/src/test/compile-fail/issue-20616-8.rs index b7bef47c4f4..5cdec33e94b 100644 --- a/src/test/compile-fail/issue-20616-8.rs +++ b/src/test/compile-fail/issue-20616-8.rs @@ -9,7 +9,7 @@ // except according to those terms. // We need all these 9 issue-20616-N.rs files -// becase we can only catch one parsing error at a time +// because we can only catch one parsing error at a time diff --git a/src/test/compile-fail/issue-20616-9.rs b/src/test/compile-fail/issue-20616-9.rs index 5c16d24cef8..7995addb692 100644 --- a/src/test/compile-fail/issue-20616-9.rs +++ b/src/test/compile-fail/issue-20616-9.rs @@ -9,7 +9,7 @@ // except according to those terms. // We need all these 9 issue-20616-N.rs files -// becase we can only catch one parsing error at a time +// because we can only catch one parsing error at a time diff --git a/src/test/compile-fail/no_crate_type.rs b/src/test/compile-fail/no_crate_type.rs index bef909917d2..b2cc5cae697 100644 --- a/src/test/compile-fail/no_crate_type.rs +++ b/src/test/compile-fail/no_crate_type.rs @@ -8,7 +8,7 @@ // option. This file may not be copied, modified, or distributed // except according to those terms. -// regresion test for issue 11256 +// regression test for issue 11256 #![crate_type] //~ ERROR `crate_type` requires a value fn main() { diff --git a/src/test/mir-opt/README.md b/src/test/mir-opt/README.md index b00b35aa29f..ad4932b9fb9 100644 --- a/src/test/mir-opt/README.md +++ b/src/test/mir-opt/README.md @@ -26,7 +26,7 @@ other non-matched lines before and after, but not between $expected_lines, should you want to skip lines, you must include an elision comment, of the form (as a regex) `//\s*...\s*`. The lines will be skipped lazily, that is, if there are two identical lines in the output that match the line after the elision -comment, the first one wil be matched. +comment, the first one will be matched. Examples: diff --git a/src/test/pretty/stmt_expr_attributes.rs b/src/test/pretty/stmt_expr_attributes.rs index 1c443020d2e..17e6119f968 100644 --- a/src/test/pretty/stmt_expr_attributes.rs +++ b/src/test/pretty/stmt_expr_attributes.rs @@ -255,7 +255,7 @@ fn _11() { while true { let _ = #[attr] break ; } || #[attr] return; let _ = #[attr] expr_mac!(); - /* FIXME: pp bug, loosing delimiter styles + /* FIXME: pp bug, losing delimiter styles let _ = #[attr] expr_mac![]; let _ = #[attr] expr_mac!{}; */ diff --git a/src/test/run-make/hotplug_codegen_backend/Makefile b/src/test/run-make/hotplug_codegen_backend/Makefile index 9a216d1d81f..2ddf3aa5439 100644 --- a/src/test/run-make/hotplug_codegen_backend/Makefile +++ b/src/test/run-make/hotplug_codegen_backend/Makefile @@ -6,4 +6,4 @@ all: -o $(TMPDIR)/the_backend.dylib $(RUSTC) some_crate.rs --crate-name some_crate --crate-type bin -o $(TMPDIR)/some_crate \ -Z codegen-backend=$(TMPDIR)/the_backend.dylib -Z unstable-options - grep -x "This has been \"compiled\" succesfully." $(TMPDIR)/some_crate + grep -x "This has been \"compiled\" successfully." $(TMPDIR)/some_crate diff --git a/src/test/run-make/hotplug_codegen_backend/the_backend.rs b/src/test/run-make/hotplug_codegen_backend/the_backend.rs index 5972149590c..9e87268e699 100644 --- a/src/test/run-make/hotplug_codegen_backend/the_backend.rs +++ b/src/test/run-make/hotplug_codegen_backend/the_backend.rs @@ -69,7 +69,7 @@ impl TransCrate for TheBackend { let output_name = out_filename(sess, crate_type, &outputs, &*crate_name.as_str()); let mut out_file = ::std::fs::File::create(output_name).unwrap(); - write!(out_file, "This has been \"compiled\" succesfully.").unwrap(); + write!(out_file, "This has been \"compiled\" successfully.").unwrap(); } Ok(()) } diff --git a/src/test/run-pass-fulldeps/proc-macro/auxiliary/derive-reexport.rs b/src/test/run-pass-fulldeps/proc-macro/auxiliary/derive-reexport.rs index 24865ea2709..cfaf913216a 100644 --- a/src/test/run-pass-fulldeps/proc-macro/auxiliary/derive-reexport.rs +++ b/src/test/run-pass-fulldeps/proc-macro/auxiliary/derive-reexport.rs @@ -8,7 +8,7 @@ // option. This file may not be copied, modified, or distributed // except according to those terms. -// ignore-test not a test, auxillary +// ignore-test not a test, auxiliary #![feature(macro_reexport)] diff --git a/src/test/run-pass/issue-29746.rs b/src/test/run-pass/issue-29746.rs index 61c601ac6a9..d4463fed1a6 100644 --- a/src/test/run-pass/issue-29746.rs +++ b/src/test/run-pass/issue-29746.rs @@ -17,7 +17,7 @@ macro_rules! zip { }; // Intermediate steps to build the zipped expression, the match pattern, and - // and the output tuple of the closure, using macro hygene to repeatedly + // and the output tuple of the closure, using macro hygiene to repeatedly // introduce new variables named 'x'. ([$a:expr, $($rest:expr),*], $zip:expr, $pat:pat, [$($flat:expr),*]) => { zip!([$($rest),*], $zip.zip($a), ($pat,x), [$($flat),*, x]) diff --git a/src/test/run-pass/issue-32008.rs b/src/test/run-pass/issue-32008.rs index cb489acf1d9..95890d2e1b4 100644 --- a/src/test/run-pass/issue-32008.rs +++ b/src/test/run-pass/issue-32008.rs @@ -9,7 +9,7 @@ // except according to those terms. // Tests that binary operators allow subtyping on both the LHS and RHS, -// and as such do not introduce unnecesarily strict lifetime constraints. +// and as such do not introduce unnecessarily strict lifetime constraints. use std::ops::Add; diff --git a/src/test/run-pass/rfc1857-drop-order.rs b/src/test/run-pass/rfc1857-drop-order.rs index b2e5ff62eb8..94b2a586ddf 100644 --- a/src/test/run-pass/rfc1857-drop-order.rs +++ b/src/test/run-pass/rfc1857-drop-order.rs @@ -67,7 +67,7 @@ fn test_drop_tuple() { panic::catch_unwind(|| { (PushOnDrop::new(2, cloned.clone()), PushOnDrop::new(1, cloned.clone()), - panic!("this panic is catched :D")); + panic!("this panic is caught :D")); }).err().unwrap(); assert_eq!(*dropped_fields.borrow(), &[1, 2]); } @@ -99,7 +99,7 @@ fn test_drop_struct() { TestStruct { x: PushOnDrop::new(2, cloned.clone()), y: PushOnDrop::new(1, cloned.clone()), - z: panic!("this panic is catched :D") + z: panic!("this panic is caught :D") }; }).err().unwrap(); assert_eq!(*dropped_fields.borrow(), &[1, 2]); @@ -111,7 +111,7 @@ fn test_drop_struct() { TestStruct { y: PushOnDrop::new(2, cloned.clone()), x: PushOnDrop::new(1, cloned.clone()), - z: panic!("this panic is catched :D") + z: panic!("this panic is caught :D") }; }).err().unwrap(); assert_eq!(*dropped_fields.borrow(), &[1, 2]); @@ -122,7 +122,7 @@ fn test_drop_struct() { panic::catch_unwind(|| { TestTupleStruct(PushOnDrop::new(2, cloned.clone()), PushOnDrop::new(1, cloned.clone()), - panic!("this panic is catched :D")); + panic!("this panic is caught :D")); }).err().unwrap(); assert_eq!(*dropped_fields.borrow(), &[1, 2]); } @@ -154,7 +154,7 @@ fn test_drop_enum() { TestEnum::Struct { x: PushOnDrop::new(2, cloned.clone()), y: PushOnDrop::new(1, cloned.clone()), - z: panic!("this panic is catched :D") + z: panic!("this panic is caught :D") }; }).err().unwrap(); assert_eq!(*dropped_fields.borrow(), &[1, 2]); @@ -166,7 +166,7 @@ fn test_drop_enum() { TestEnum::Struct { y: PushOnDrop::new(2, cloned.clone()), x: PushOnDrop::new(1, cloned.clone()), - z: panic!("this panic is catched :D") + z: panic!("this panic is caught :D") }; }).err().unwrap(); assert_eq!(*dropped_fields.borrow(), &[1, 2]); @@ -177,7 +177,7 @@ fn test_drop_enum() { panic::catch_unwind(|| { TestEnum::Tuple(PushOnDrop::new(2, cloned.clone()), PushOnDrop::new(1, cloned.clone()), - panic!("this panic is catched :D")); + panic!("this panic is caught :D")); }).err().unwrap(); assert_eq!(*dropped_fields.borrow(), &[1, 2]); } @@ -207,7 +207,7 @@ fn test_drop_list() { vec![ PushOnDrop::new(2, cloned.clone()), PushOnDrop::new(1, cloned.clone()), - panic!("this panic is catched :D") + panic!("this panic is caught :D") ]; }).err().unwrap(); assert_eq!(*dropped_fields.borrow(), &[1, 2]); @@ -219,7 +219,7 @@ fn test_drop_list() { [ PushOnDrop::new(2, cloned.clone()), PushOnDrop::new(1, cloned.clone()), - panic!("this panic is catched :D") + panic!("this panic is caught :D") ]; }).err().unwrap(); assert_eq!(*dropped_fields.borrow(), &[1, 2]); diff --git a/src/test/run-pass/simd-target-feature-mixup.rs b/src/test/run-pass/simd-target-feature-mixup.rs index 2c9ef59709d..3c54921ac6e 100644 --- a/src/test/run-pass/simd-target-feature-mixup.rs +++ b/src/test/run-pass/simd-target-feature-mixup.rs @@ -30,7 +30,7 @@ fn main() { // We don't actually know if our computer has the requisite target features // for the test below. Testing for that will get added to libstd later so - // for now just asume sigill means this is a machine that can't run this test. + // for now just assume sigill means this is a machine that can't run this test. if is_sigill(status) { println!("sigill with {}, assuming spurious", level); continue diff --git a/src/test/rustdoc/impl-parts-crosscrate.rs b/src/test/rustdoc/impl-parts-crosscrate.rs index 5fa2e03e0a8..1d055ccbead 100644 --- a/src/test/rustdoc/impl-parts-crosscrate.rs +++ b/src/test/rustdoc/impl-parts-crosscrate.rs @@ -17,7 +17,7 @@ extern crate rustdoc_impl_parts_crosscrate; pub struct Bar { t: T } -// The output file is html embeded in javascript, so the html tags +// The output file is html embedded in javascript, so the html tags // aren't stripped by the processing script and we can't check for the // full impl string. Instead, just make sure something from each part // is mentioned. diff --git a/src/test/ui/explain.stdout b/src/test/ui/explain.stdout index 0bbbd95320a..411cdfb335b 100644 --- a/src/test/ui/explain.stdout +++ b/src/test/ui/explain.stdout @@ -45,7 +45,7 @@ is a function pointer, which is not zero-sized. This pattern should be rewritten. There are a few possible ways to do this: - change the original fn declaration to match the expected signature, - and do the cast in the fn body (the prefered option) + and do the cast in the fn body (the preferred option) - cast the fn item fo a fn pointer before calling transmute, as shown here: ``` diff --git a/src/test/ui/feature-gate/issue-43106-gating-of-builtin-attrs.rs b/src/test/ui/feature-gate/issue-43106-gating-of-builtin-attrs.rs index 029949b2604..21950402c8c 100644 --- a/src/test/ui/feature-gate/issue-43106-gating-of-builtin-attrs.rs +++ b/src/test/ui/feature-gate/issue-43106-gating-of-builtin-attrs.rs @@ -509,7 +509,7 @@ mod reexport_test_harness_main { //~^ WARN unused attribute } -// Cannnot feed "2700" to `#[macro_escape]` without signaling an error. +// Cannot feed "2700" to `#[macro_escape]` without signaling an error. #[macro_escape] //~^ WARN macro_escape is a deprecated synonym for macro_use mod macro_escape { diff --git a/src/test/ui/lifetime-errors/liveness-assign-imm-local-notes.rs b/src/test/ui/lifetime-errors/liveness-assign-imm-local-notes.rs index d4ef87cdd76..20a2cbfd3aa 100644 --- a/src/test/ui/lifetime-errors/liveness-assign-imm-local-notes.rs +++ b/src/test/ui/lifetime-errors/liveness-assign-imm-local-notes.rs @@ -9,7 +9,7 @@ // except according to those terms. // FIXME: Change to UI Test -// Check notes are placed on an assignment that can actually preceed the current assigmnent +// Check notes are placed on an assignment that can actually precede the current assigmnent // Don't emmit a first assignment for assignment in a loop. // compile-flags: -Zborrowck=compare -- cgit 1.4.1-3-g733a5 From d549db8031a07b79009f9efe8b3233cd8900c82b Mon Sep 17 00:00:00 2001 From: Vitali Lovich Date: Sat, 17 Feb 2018 09:17:58 -0800 Subject: Fix tidy violation --- src/libstd/sync/condvar.rs | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) (limited to 'src/libstd/sync') diff --git a/src/libstd/sync/condvar.rs b/src/libstd/sync/condvar.rs index 546e105deb7..7f9b5667628 100644 --- a/src/libstd/sync/condvar.rs +++ b/src/libstd/sync/condvar.rs @@ -466,9 +466,11 @@ impl Condvar { /// /// // wait for the thread to start up /// let &(ref lock, ref cvar) = &*pair; - /// let result = cvar.wait_timeout_until(lock.lock().unwrap(), Duration::from_millis(100), |started| { - /// *started - /// }).unwrap(); + /// let result = cvar.wait_timeout_until( + /// lock.lock().unwrap(), + /// Duration::from_millis(100), + /// |started| started, + /// ).unwrap(); /// if result.1.timed_out() { /// // timed-out without the condition ever evaluating to true. /// } -- cgit 1.4.1-3-g733a5 From 14b403c91ab9a1e4b776e00adcd9d88153e3b736 Mon Sep 17 00:00:00 2001 From: Vitali Lovich Date: Tue, 20 Feb 2018 13:07:21 -0800 Subject: Fix doc compile error --- src/libstd/sync/condvar.rs | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'src/libstd/sync') diff --git a/src/libstd/sync/condvar.rs b/src/libstd/sync/condvar.rs index 7f9b5667628..3e40cbb37e3 100644 --- a/src/libstd/sync/condvar.rs +++ b/src/libstd/sync/condvar.rs @@ -469,7 +469,7 @@ impl Condvar { /// let result = cvar.wait_timeout_until( /// lock.lock().unwrap(), /// Duration::from_millis(100), - /// |started| started, + /// |&mut started| started, /// ).unwrap(); /// if result.1.timed_out() { /// // timed-out without the condition ever evaluating to true. -- cgit 1.4.1-3-g733a5 From 1b895d8b88413f72230fbc0f00c67328870a2e9a Mon Sep 17 00:00:00 2001 From: Simon Sapin Date: Tue, 3 Apr 2018 14:36:57 +0200 Subject: Import the `alloc` crate as `alloc_crate` in std MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit … to make the name `alloc` available. --- src/libstd/collections/hash/map.rs | 4 +--- src/libstd/collections/hash/table.rs | 5 +---- src/libstd/collections/mod.rs | 10 +++++----- src/libstd/error.rs | 10 +++++----- src/libstd/heap.rs | 2 +- src/libstd/lib.rs | 18 +++++++++--------- src/libstd/sync/mod.rs | 2 +- src/libstd/sync/mpsc/mpsc_queue.rs | 3 +-- src/libstd/sync/mpsc/spsc_queue.rs | 2 +- src/libstd/sys/cloudabi/thread.rs | 2 +- src/libstd/sys/redox/thread.rs | 2 +- src/libstd/sys/unix/thread.rs | 2 +- src/libstd/sys/wasm/thread.rs | 2 +- src/libstd/sys/windows/process.rs | 2 +- src/libstd/sys/windows/thread.rs | 2 +- src/libstd/sys_common/at_exit_imp.rs | 2 +- src/libstd/sys_common/process.rs | 2 +- src/libstd/sys_common/thread.rs | 2 +- 18 files changed, 34 insertions(+), 40 deletions(-) (limited to 'src/libstd/sync') diff --git a/src/libstd/collections/hash/map.rs b/src/libstd/collections/hash/map.rs index e0b48e565d0..73a5df8dc28 100644 --- a/src/libstd/collections/hash/map.rs +++ b/src/libstd/collections/hash/map.rs @@ -11,15 +11,13 @@ use self::Entry::*; use self::VacantEntryState::*; -use alloc::heap::Heap; -use alloc::allocator::CollectionAllocErr; use cell::Cell; -use core::heap::Alloc; use borrow::Borrow; use cmp::max; use fmt::{self, Debug}; #[allow(deprecated)] use hash::{Hash, Hasher, BuildHasher, SipHasher13}; +use heap::{Heap, Alloc, CollectionAllocErr}; use iter::{FromIterator, FusedIterator}; use mem::{self, replace}; use ops::{Deref, Index}; diff --git a/src/libstd/collections/hash/table.rs b/src/libstd/collections/hash/table.rs index fa6053d3f6d..878cd82a258 100644 --- a/src/libstd/collections/hash/table.rs +++ b/src/libstd/collections/hash/table.rs @@ -8,17 +8,14 @@ // option. This file may not be copied, modified, or distributed // except according to those terms. -use alloc::heap::Heap; -use core::heap::{Alloc, Layout}; - use cmp; use hash::{BuildHasher, Hash, Hasher}; +use heap::{Heap, Alloc, Layout, CollectionAllocErr}; use marker; use mem::{align_of, size_of, needs_drop}; use mem; use ops::{Deref, DerefMut}; use ptr::{self, Unique, NonNull}; -use alloc::allocator::CollectionAllocErr; use self::BucketState::*; diff --git a/src/libstd/collections/mod.rs b/src/libstd/collections/mod.rs index c7ad27d8d26..9cf73824dea 100644 --- a/src/libstd/collections/mod.rs +++ b/src/libstd/collections/mod.rs @@ -424,13 +424,13 @@ #[doc(hidden)] pub use ops::Bound; #[stable(feature = "rust1", since = "1.0.0")] -pub use alloc::{BinaryHeap, BTreeMap, BTreeSet}; +pub use alloc_crate::{BinaryHeap, BTreeMap, BTreeSet}; #[stable(feature = "rust1", since = "1.0.0")] -pub use alloc::{LinkedList, VecDeque}; +pub use alloc_crate::{LinkedList, VecDeque}; #[stable(feature = "rust1", since = "1.0.0")] -pub use alloc::{binary_heap, btree_map, btree_set}; +pub use alloc_crate::{binary_heap, btree_map, btree_set}; #[stable(feature = "rust1", since = "1.0.0")] -pub use alloc::{linked_list, vec_deque}; +pub use alloc_crate::{linked_list, vec_deque}; #[stable(feature = "rust1", since = "1.0.0")] pub use self::hash_map::HashMap; @@ -446,7 +446,7 @@ pub mod range { } #[unstable(feature = "try_reserve", reason = "new API", issue="48043")] -pub use alloc::allocator::CollectionAllocErr; +pub use heap::CollectionAllocErr; mod hash; diff --git a/src/libstd/error.rs b/src/libstd/error.rs index 3d0c96585b5..4edb897350e 100644 --- a/src/libstd/error.rs +++ b/src/libstd/error.rs @@ -51,13 +51,13 @@ // coherence challenge (e.g., specialization, neg impls, etc) we can // reconsider what crate these items belong in. -use alloc::allocator; use any::TypeId; use borrow::Cow; use cell; use char; use core::array; use fmt::{self, Debug, Display}; +use heap::{AllocErr, CannotReallocInPlace}; use mem::transmute; use num; use str; @@ -241,18 +241,18 @@ impl Error for ! { #[unstable(feature = "allocator_api", reason = "the precise API and guarantees it provides may be tweaked.", issue = "32838")] -impl Error for allocator::AllocErr { +impl Error for AllocErr { fn description(&self) -> &str { - allocator::AllocErr::description(self) + AllocErr::description(self) } } #[unstable(feature = "allocator_api", reason = "the precise API and guarantees it provides may be tweaked.", issue = "32838")] -impl Error for allocator::CannotReallocInPlace { +impl Error for CannotReallocInPlace { fn description(&self) -> &str { - allocator::CannotReallocInPlace::description(self) + CannotReallocInPlace::description(self) } } diff --git a/src/libstd/heap.rs b/src/libstd/heap.rs index 2cf06018087..b42a1052c49 100644 --- a/src/libstd/heap.rs +++ b/src/libstd/heap.rs @@ -12,7 +12,7 @@ #![unstable(issue = "32838", feature = "allocator_api")] -pub use alloc::heap::Heap; +pub use alloc_crate::heap::Heap; pub use alloc_system::System; #[doc(inline)] pub use core::heap::*; diff --git a/src/libstd/lib.rs b/src/libstd/lib.rs index c82d600e4a1..ef4205e7a62 100644 --- a/src/libstd/lib.rs +++ b/src/libstd/lib.rs @@ -351,7 +351,7 @@ extern crate core as __core; #[macro_use] #[macro_reexport(vec, format)] -extern crate alloc; +extern crate alloc as alloc_crate; extern crate alloc_system; #[doc(masked)] extern crate libc; @@ -437,21 +437,21 @@ pub use core::u32; #[stable(feature = "rust1", since = "1.0.0")] pub use core::u64; #[stable(feature = "rust1", since = "1.0.0")] -pub use alloc::boxed; +pub use alloc_crate::boxed; #[stable(feature = "rust1", since = "1.0.0")] -pub use alloc::rc; +pub use alloc_crate::rc; #[stable(feature = "rust1", since = "1.0.0")] -pub use alloc::borrow; +pub use alloc_crate::borrow; #[stable(feature = "rust1", since = "1.0.0")] -pub use alloc::fmt; +pub use alloc_crate::fmt; #[stable(feature = "rust1", since = "1.0.0")] -pub use alloc::slice; +pub use alloc_crate::slice; #[stable(feature = "rust1", since = "1.0.0")] -pub use alloc::str; +pub use alloc_crate::str; #[stable(feature = "rust1", since = "1.0.0")] -pub use alloc::string; +pub use alloc_crate::string; #[stable(feature = "rust1", since = "1.0.0")] -pub use alloc::vec; +pub use alloc_crate::vec; #[stable(feature = "rust1", since = "1.0.0")] pub use core::char; #[stable(feature = "i128", since = "1.26.0")] diff --git a/src/libstd/sync/mod.rs b/src/libstd/sync/mod.rs index 289b47b3484..642b284c6c7 100644 --- a/src/libstd/sync/mod.rs +++ b/src/libstd/sync/mod.rs @@ -18,7 +18,7 @@ #![stable(feature = "rust1", since = "1.0.0")] #[stable(feature = "rust1", since = "1.0.0")] -pub use alloc::arc::{Arc, Weak}; +pub use alloc_crate::arc::{Arc, Weak}; #[stable(feature = "rust1", since = "1.0.0")] pub use core::sync::atomic; diff --git a/src/libstd/sync/mpsc/mpsc_queue.rs b/src/libstd/sync/mpsc/mpsc_queue.rs index 296773d20f6..df945ac3859 100644 --- a/src/libstd/sync/mpsc/mpsc_queue.rs +++ b/src/libstd/sync/mpsc/mpsc_queue.rs @@ -23,10 +23,9 @@ pub use self::PopResult::*; -use alloc::boxed::Box; use core::ptr; use core::cell::UnsafeCell; - +use boxed::Box; use sync::atomic::{AtomicPtr, Ordering}; /// A result of the `pop` function. diff --git a/src/libstd/sync/mpsc/spsc_queue.rs b/src/libstd/sync/mpsc/spsc_queue.rs index cc4be92276a..9482f6958b3 100644 --- a/src/libstd/sync/mpsc/spsc_queue.rs +++ b/src/libstd/sync/mpsc/spsc_queue.rs @@ -16,7 +16,7 @@ // http://www.1024cores.net/home/lock-free-algorithms/queues/unbounded-spsc-queue -use alloc::boxed::Box; +use boxed::Box; use core::ptr; use core::cell::UnsafeCell; diff --git a/src/libstd/sys/cloudabi/thread.rs b/src/libstd/sys/cloudabi/thread.rs index a22d9053b69..5d66936b2a4 100644 --- a/src/libstd/sys/cloudabi/thread.rs +++ b/src/libstd/sys/cloudabi/thread.rs @@ -8,7 +8,7 @@ // option. This file may not be copied, modified, or distributed // except according to those terms. -use alloc::boxed::FnBox; +use boxed::FnBox; use cmp; use ffi::CStr; use io; diff --git a/src/libstd/sys/redox/thread.rs b/src/libstd/sys/redox/thread.rs index f20350269b7..110d46ca3ab 100644 --- a/src/libstd/sys/redox/thread.rs +++ b/src/libstd/sys/redox/thread.rs @@ -8,7 +8,7 @@ // option. This file may not be copied, modified, or distributed // except according to those terms. -use alloc::boxed::FnBox; +use boxed::FnBox; use ffi::CStr; use io; use mem; diff --git a/src/libstd/sys/unix/thread.rs b/src/libstd/sys/unix/thread.rs index 2db3d4a5744..9e388808030 100644 --- a/src/libstd/sys/unix/thread.rs +++ b/src/libstd/sys/unix/thread.rs @@ -8,7 +8,7 @@ // option. This file may not be copied, modified, or distributed // except according to those terms. -use alloc::boxed::FnBox; +use boxed::FnBox; use cmp; use ffi::CStr; use io; diff --git a/src/libstd/sys/wasm/thread.rs b/src/libstd/sys/wasm/thread.rs index 7345843b975..728e678a2e8 100644 --- a/src/libstd/sys/wasm/thread.rs +++ b/src/libstd/sys/wasm/thread.rs @@ -8,7 +8,7 @@ // option. This file may not be copied, modified, or distributed // except according to those terms. -use alloc::boxed::FnBox; +use boxed::FnBox; use ffi::CStr; use io; use sys::{unsupported, Void}; diff --git a/src/libstd/sys/windows/process.rs b/src/libstd/sys/windows/process.rs index bd5507e8f89..be442f41374 100644 --- a/src/libstd/sys/windows/process.rs +++ b/src/libstd/sys/windows/process.rs @@ -31,7 +31,7 @@ use sys::stdio; use sys::cvt; use sys_common::{AsInner, FromInner, IntoInner}; use sys_common::process::{CommandEnv, EnvKey}; -use alloc::borrow::Borrow; +use borrow::Borrow; //////////////////////////////////////////////////////////////////////////////// // Command diff --git a/src/libstd/sys/windows/thread.rs b/src/libstd/sys/windows/thread.rs index 4b3d1b586b5..b6f63303dc2 100644 --- a/src/libstd/sys/windows/thread.rs +++ b/src/libstd/sys/windows/thread.rs @@ -8,7 +8,7 @@ // option. This file may not be copied, modified, or distributed // except according to those terms. -use alloc::boxed::FnBox; +use boxed::FnBox; use io; use ffi::CStr; use mem; diff --git a/src/libstd/sys_common/at_exit_imp.rs b/src/libstd/sys_common/at_exit_imp.rs index ce6fd4cb075..26da51c9825 100644 --- a/src/libstd/sys_common/at_exit_imp.rs +++ b/src/libstd/sys_common/at_exit_imp.rs @@ -12,7 +12,7 @@ //! //! Documentation can be found on the `rt::at_exit` function. -use alloc::boxed::FnBox; +use boxed::FnBox; use ptr; use sys_common::mutex::Mutex; diff --git a/src/libstd/sys_common/process.rs b/src/libstd/sys_common/process.rs index d0c5951bd6c..ddf0ebe603e 100644 --- a/src/libstd/sys_common/process.rs +++ b/src/libstd/sys_common/process.rs @@ -14,7 +14,7 @@ use ffi::{OsStr, OsString}; use env; use collections::BTreeMap; -use alloc::borrow::Borrow; +use borrow::Borrow; pub trait EnvKey: From + Into + diff --git a/src/libstd/sys_common/thread.rs b/src/libstd/sys_common/thread.rs index f1379b6ec63..da6f58ef6bb 100644 --- a/src/libstd/sys_common/thread.rs +++ b/src/libstd/sys_common/thread.rs @@ -8,7 +8,7 @@ // option. This file may not be copied, modified, or distributed // except according to those terms. -use alloc::boxed::FnBox; +use boxed::FnBox; use env; use sync::atomic::{self, Ordering}; use sys::stack_overflow; -- cgit 1.4.1-3-g733a5 From 3dbdccc6a9c1ead58325d415381b25c676386c34 Mon Sep 17 00:00:00 2001 From: "Zack M. Davis" Date: Sat, 10 Mar 2018 16:23:28 -0800 Subject: stabilize `#[must_use]` for functions and must-use operators This is in the matter of RFC 1940 and tracking issue #43302. --- .../src/language-features/fn-must-use.md | 30 ---- src/liballoc/lib.rs | 2 +- src/liballoc/tests/slice.rs | 1 + src/libcore/lib.rs | 2 +- src/librustc_lint/unused.rs | 104 +++++++------- src/libstd/ffi/c_str.rs | 2 + src/libstd/sync/mpsc/select.rs | 2 + src/libsyntax/feature_gate.rs | 22 +-- .../ui/feature-gate-fn_must_use-cap-lints-allow.rs | 22 --- ...feature-gate-fn_must_use-cap-lints-allow.stderr | 8 -- src/test/ui/feature-gate-fn_must_use.rs | 31 ----- src/test/ui/feature-gate-fn_must_use.stderr | 24 ---- .../issue-43106-gating-of-builtin-attrs.rs | 1 - .../issue-43106-gating-of-builtin-attrs.stderr | 154 ++++++++++----------- src/test/ui/fn_must_use.rs | 78 +++++++++++ src/test/ui/fn_must_use.stderr | 48 +++++++ src/test/ui/lint/must-use-ops.rs | 1 - src/test/ui/lint/must-use-ops.stderr | 44 +++--- .../rfc_1940-must_use_on_functions/fn_must_use.rs | 79 ----------- .../fn_must_use.stderr | 48 ------- src/test/ui/span/gated-features-attr-spans.rs | 23 --- src/test/ui/span/gated-features-attr-spans.stderr | 18 +-- 22 files changed, 284 insertions(+), 460 deletions(-) delete mode 100644 src/doc/unstable-book/src/language-features/fn-must-use.md delete mode 100644 src/test/ui/feature-gate-fn_must_use-cap-lints-allow.rs delete mode 100644 src/test/ui/feature-gate-fn_must_use-cap-lints-allow.stderr delete mode 100644 src/test/ui/feature-gate-fn_must_use.rs delete mode 100644 src/test/ui/feature-gate-fn_must_use.stderr create mode 100644 src/test/ui/fn_must_use.rs create mode 100644 src/test/ui/fn_must_use.stderr delete mode 100644 src/test/ui/rfc_1940-must_use_on_functions/fn_must_use.rs delete mode 100644 src/test/ui/rfc_1940-must_use_on_functions/fn_must_use.stderr (limited to 'src/libstd/sync') diff --git a/src/doc/unstable-book/src/language-features/fn-must-use.md b/src/doc/unstable-book/src/language-features/fn-must-use.md deleted file mode 100644 index 71b6cd663a0..00000000000 --- a/src/doc/unstable-book/src/language-features/fn-must-use.md +++ /dev/null @@ -1,30 +0,0 @@ -# `fn_must_use` - -The tracking issue for this feature is [#43302]. - -[#43302]: https://github.com/rust-lang/rust/issues/43302 - ------------------------- - -The `fn_must_use` feature allows functions and methods to be annotated with -`#[must_use]`, indicating that the `unused_must_use` lint should require their -return values to be used (similarly to how types annotated with `must_use`, -most notably `Result`, are linted if not used). - -## Examples - -```rust -#![feature(fn_must_use)] - -#[must_use] -fn double(x: i32) -> i32 { - 2 * x -} - -fn main() { - double(4); // warning: unused return value of `double` which must be used - - let _ = double(4); // (no warning) -} - -``` diff --git a/src/liballoc/lib.rs b/src/liballoc/lib.rs index 021395d0c82..fa74352c23c 100644 --- a/src/liballoc/lib.rs +++ b/src/liballoc/lib.rs @@ -96,7 +96,7 @@ #![feature(dropck_eyepatch)] #![feature(exact_size_is_empty)] #![feature(fmt_internals)] -#![feature(fn_must_use)] +#![cfg_attr(stage0, feature(fn_must_use))] #![feature(from_ref)] #![feature(fundamental)] #![feature(lang_items)] diff --git a/src/liballoc/tests/slice.rs b/src/liballoc/tests/slice.rs index 99d9c51efc7..6fd0b33f02a 100644 --- a/src/liballoc/tests/slice.rs +++ b/src/liballoc/tests/slice.rs @@ -1282,6 +1282,7 @@ fn test_box_slice_clone() { } #[test] +#[allow(unused_must_use)] // here, we care about the side effects of `.clone()` #[cfg_attr(target_os = "emscripten", ignore)] fn test_box_slice_clone_panics() { use std::sync::Arc; diff --git a/src/libcore/lib.rs b/src/libcore/lib.rs index 0e21a3327fd..f4ed24cc3a3 100644 --- a/src/libcore/lib.rs +++ b/src/libcore/lib.rs @@ -76,7 +76,6 @@ #![feature(doc_cfg)] #![feature(doc_spotlight)] #![feature(extern_types)] -#![feature(fn_must_use)] #![feature(fundamental)] #![feature(intrinsics)] #![feature(iterator_flatten)] @@ -114,6 +113,7 @@ #![cfg_attr(stage0, feature(target_feature))] #![cfg_attr(stage0, feature(cfg_target_feature))] +#![cfg_attr(stage0, feature(fn_must_use))] #[prelude_import] #[allow(unused)] diff --git a/src/librustc_lint/unused.rs b/src/librustc_lint/unused.rs index c32e9cdce0e..9e1b75ba336 100644 --- a/src/librustc_lint/unused.rs +++ b/src/librustc_lint/unused.rs @@ -73,59 +73,59 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for UnusedResults { let mut fn_warned = false; let mut op_warned = false; - if cx.tcx.features().fn_must_use { - let maybe_def = match expr.node { - hir::ExprCall(ref callee, _) => { - match callee.node { - hir::ExprPath(ref qpath) => { - let def = cx.tables.qpath_def(qpath, callee.hir_id); - if let Def::Fn(_) = def { - Some(def) - } else { // `Def::Local` if it was a closure, for which we - None // do not currently support must-use linting - } - }, - _ => None - } - }, - hir::ExprMethodCall(..) => { - cx.tables.type_dependent_defs().get(expr.hir_id).cloned() - }, - _ => None - }; - if let Some(def) = maybe_def { - let def_id = def.def_id(); - fn_warned = check_must_use(cx, def_id, s.span, "return value of "); - } - let must_use_op = match expr.node { - // Hardcoding operators here seemed more expedient than the - // refactoring that would be needed to look up the `#[must_use]` - // attribute which does exist on the comparison trait methods - hir::ExprBinary(bin_op, ..) => { - match bin_op.node { - hir::BiEq | hir::BiLt | hir::BiLe | hir::BiNe | hir::BiGe | hir::BiGt => { - Some("comparison") - }, - hir::BiAdd | hir::BiSub | hir::BiDiv | hir::BiMul | hir::BiRem => { - Some("arithmetic operation") - }, - hir::BiAnd | hir::BiOr => { - Some("logical operation") - }, - hir::BiBitXor | hir::BiBitAnd | hir::BiBitOr | hir::BiShl | hir::BiShr => { - Some("bitwise operation") - }, - } - }, - hir::ExprUnary(..) => Some("unary operation"), - _ => None - }; - if let Some(must_use_op) = must_use_op { - cx.span_lint(UNUSED_MUST_USE, expr.span, - &format!("unused {} which must be used", must_use_op)); - op_warned = true; - } + let maybe_def = match expr.node { + hir::ExprCall(ref callee, _) => { + match callee.node { + hir::ExprPath(ref qpath) => { + let def = cx.tables.qpath_def(qpath, callee.hir_id); + if let Def::Fn(_) = def { + Some(def) + } else { // `Def::Local` if it was a closure, for which we + None // do not currently support must-use linting + } + }, + _ => None + } + }, + hir::ExprMethodCall(..) => { + cx.tables.type_dependent_defs().get(expr.hir_id).cloned() + }, + _ => None + }; + if let Some(def) = maybe_def { + let def_id = def.def_id(); + fn_warned = check_must_use(cx, def_id, s.span, "return value of "); } + let must_use_op = match expr.node { + // Hardcoding operators here seemed more expedient than the + // refactoring that would be needed to look up the `#[must_use]` + // attribute which does exist on the comparison trait methods + hir::ExprBinary(bin_op, ..) => { + match bin_op.node { + hir::BiEq | hir::BiLt | hir::BiLe | hir::BiNe | hir::BiGe | hir::BiGt => { + Some("comparison") + }, + hir::BiAdd | hir::BiSub | hir::BiDiv | hir::BiMul | hir::BiRem => { + Some("arithmetic operation") + }, + hir::BiAnd | hir::BiOr => { + Some("logical operation") + }, + hir::BiBitXor | hir::BiBitAnd | hir::BiBitOr | hir::BiShl | hir::BiShr => { + Some("bitwise operation") + }, + } + }, + hir::ExprUnary(..) => Some("unary operation"), + _ => None + }; + + if let Some(must_use_op) = must_use_op { + cx.span_lint(UNUSED_MUST_USE, expr.span, + &format!("unused {} which must be used", must_use_op)); + op_warned = true; + } + if !(ty_warned || fn_warned || op_warned) { cx.span_lint(UNUSED_RESULTS, s.span, "unused result"); } diff --git a/src/libstd/ffi/c_str.rs b/src/libstd/ffi/c_str.rs index c88c2bc9137..d4937c00012 100644 --- a/src/libstd/ffi/c_str.rs +++ b/src/libstd/ffi/c_str.rs @@ -988,6 +988,7 @@ impl CStr { /// behavior when `ptr` is used inside the `unsafe` block: /// /// ```no_run + /// # #![allow(unused_must_use)] /// use std::ffi::{CString}; /// /// let ptr = CString::new("Hello").unwrap().as_ptr(); @@ -1003,6 +1004,7 @@ impl CStr { /// To fix the problem, bind the `CString` to a local variable: /// /// ```no_run + /// # #![allow(unused_must_use)] /// use std::ffi::{CString}; /// /// let hello = CString::new("Hello").unwrap(); diff --git a/src/libstd/sync/mpsc/select.rs b/src/libstd/sync/mpsc/select.rs index a9f3cea243f..9310dad9172 100644 --- a/src/libstd/sync/mpsc/select.rs +++ b/src/libstd/sync/mpsc/select.rs @@ -518,6 +518,7 @@ mod tests { } } + #[allow(unused_must_use)] #[test] fn cloning() { let (tx1, rx1) = channel::(); @@ -540,6 +541,7 @@ mod tests { tx3.send(()).unwrap(); } + #[allow(unused_must_use)] #[test] fn cloning2() { let (tx1, rx1) = channel::(); diff --git a/src/libsyntax/feature_gate.rs b/src/libsyntax/feature_gate.rs index a4a83712a08..f16b1ba440a 100644 --- a/src/libsyntax/feature_gate.rs +++ b/src/libsyntax/feature_gate.rs @@ -369,9 +369,6 @@ declare_features! ( // #[doc(include="some-file")] (active, external_doc, "1.22.0", Some(44732), None), - // allow `#[must_use]` on functions and comparison operators (RFC 1940) - (active, fn_must_use, "1.21.0", Some(43302), None), - // Future-proofing enums/structs with #[non_exhaustive] attribute (RFC 2008) (active, non_exhaustive, "1.22.0", Some(44109), None), @@ -591,6 +588,8 @@ declare_features! ( (accepted, target_feature, "1.27.0", None, None), // Trait object syntax with `dyn` prefix (accepted, dyn_trait, "1.27.0", Some(44662), None), + // allow `#[must_use]` on functions; and, must-use operators (RFC 1940) + (accepted, fn_must_use, "1.27.0", Some(43302), None), ); // If you change this, please modify src/doc/unstable-book as well. You must @@ -1545,11 +1544,6 @@ impl<'a> Visitor<'a> for PostExpansionVisitor<'a> { function may change over time, for now \ a top-level `fn main()` is required"); } - if let Some(attr) = attr::find_by_name(&i.attrs[..], "must_use") { - gate_feature_post!(&self, fn_must_use, attr.span, - "`#[must_use]` on functions is experimental", - GateStrength::Soft); - } } ast::ItemKind::Struct(..) => { @@ -1581,7 +1575,7 @@ impl<'a> Visitor<'a> for PostExpansionVisitor<'a> { "trait aliases are not yet fully implemented"); } - ast::ItemKind::Impl(_, polarity, defaultness, _, _, _, ref impl_items) => { + ast::ItemKind::Impl(_, polarity, defaultness, _, _, _, _) => { if polarity == ast::ImplPolarity::Negative { gate_feature_post!(&self, optin_builtin_traits, i.span, @@ -1594,16 +1588,6 @@ impl<'a> Visitor<'a> for PostExpansionVisitor<'a> { i.span, "specialization is unstable"); } - - for impl_item in impl_items { - if let ast::ImplItemKind::Method(..) = impl_item.node { - if let Some(attr) = attr::find_by_name(&impl_item.attrs[..], "must_use") { - gate_feature_post!(&self, fn_must_use, attr.span, - "`#[must_use]` on methods is experimental", - GateStrength::Soft); - } - } - } } ast::ItemKind::Trait(ast::IsAuto::Yes, ..) => { diff --git a/src/test/ui/feature-gate-fn_must_use-cap-lints-allow.rs b/src/test/ui/feature-gate-fn_must_use-cap-lints-allow.rs deleted file mode 100644 index 1c04199c05f..00000000000 --- a/src/test/ui/feature-gate-fn_must_use-cap-lints-allow.rs +++ /dev/null @@ -1,22 +0,0 @@ -// Copyright 2017 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. - -// compile-flags: --cap-lints allow - -// This tests that the fn_must_use feature-gate warning respects the lint -// cap. (See discussion in Issue #44213.) - -#![feature(rustc_attrs)] - -#[must_use] // (no feature-gate warning because of the lint cap!) -fn need_to_use_it() -> bool { true } - -#[rustc_error] -fn main() {} //~ ERROR compilation successful diff --git a/src/test/ui/feature-gate-fn_must_use-cap-lints-allow.stderr b/src/test/ui/feature-gate-fn_must_use-cap-lints-allow.stderr deleted file mode 100644 index a2c1dedff38..00000000000 --- a/src/test/ui/feature-gate-fn_must_use-cap-lints-allow.stderr +++ /dev/null @@ -1,8 +0,0 @@ -error: compilation successful - --> $DIR/feature-gate-fn_must_use-cap-lints-allow.rs:22:1 - | -LL | fn main() {} //~ ERROR compilation successful - | ^^^^^^^^^^^^ - -error: aborting due to previous error - diff --git a/src/test/ui/feature-gate-fn_must_use.rs b/src/test/ui/feature-gate-fn_must_use.rs deleted file mode 100644 index 72fdcc76cf4..00000000000 --- a/src/test/ui/feature-gate-fn_must_use.rs +++ /dev/null @@ -1,31 +0,0 @@ -// Copyright 2017 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. - -#![feature(rustc_attrs)] - -struct MyStruct; - -impl MyStruct { - #[must_use] //~ WARN `#[must_use]` on methods is experimental - fn need_to_use_method() -> bool { true } -} - -#[must_use] //~ WARN `#[must_use]` on functions is experimental -fn need_to_use_it() -> bool { true } - - -// Feature gates are tidy-required to have a specially named (or -// comment-annotated) compile-fail test (which MUST fail), but for -// backwards-compatibility reasons, we want `#[must_use]` on functions to be -// compilable even if the `fn_must_use` feature is absent, thus necessitating -// the usage of `#[rustc_error]` here, pragmatically if awkwardly solving this -// dilemma until a superior solution can be devised. -#[rustc_error] -fn main() {} //~ ERROR compilation successful diff --git a/src/test/ui/feature-gate-fn_must_use.stderr b/src/test/ui/feature-gate-fn_must_use.stderr deleted file mode 100644 index 431c57abd26..00000000000 --- a/src/test/ui/feature-gate-fn_must_use.stderr +++ /dev/null @@ -1,24 +0,0 @@ -warning: `#[must_use]` on methods is experimental (see issue #43302) - --> $DIR/feature-gate-fn_must_use.rs:16:5 - | -LL | #[must_use] //~ WARN `#[must_use]` on methods is experimental - | ^^^^^^^^^^^ - | - = help: add #![feature(fn_must_use)] to the crate attributes to enable - -warning: `#[must_use]` on functions is experimental (see issue #43302) - --> $DIR/feature-gate-fn_must_use.rs:20:1 - | -LL | #[must_use] //~ WARN `#[must_use]` on functions is experimental - | ^^^^^^^^^^^ - | - = help: add #![feature(fn_must_use)] to the crate attributes to enable - -error: compilation successful - --> $DIR/feature-gate-fn_must_use.rs:31:1 - | -LL | fn main() {} //~ ERROR compilation successful - | ^^^^^^^^^^^^ - -error: aborting due to previous error - diff --git a/src/test/ui/feature-gate/issue-43106-gating-of-builtin-attrs.rs b/src/test/ui/feature-gate/issue-43106-gating-of-builtin-attrs.rs index 21950402c8c..7b0c81dbab6 100644 --- a/src/test/ui/feature-gate/issue-43106-gating-of-builtin-attrs.rs +++ b/src/test/ui/feature-gate/issue-43106-gating-of-builtin-attrs.rs @@ -661,7 +661,6 @@ mod must_use { mod inner { #![must_use="1400"] } #[must_use = "1400"] fn f() { } - //~^ WARN `#[must_use]` on functions is experimental #[must_use = "1400"] struct S; diff --git a/src/test/ui/feature-gate/issue-43106-gating-of-builtin-attrs.stderr b/src/test/ui/feature-gate/issue-43106-gating-of-builtin-attrs.stderr index 0beed627987..76ab50c9089 100644 --- a/src/test/ui/feature-gate/issue-43106-gating-of-builtin-attrs.stderr +++ b/src/test/ui/feature-gate/issue-43106-gating-of-builtin-attrs.stderr @@ -12,14 +12,6 @@ LL | mod inner { #![macro_escape] } | = help: consider an outer attribute, #[macro_use] mod ... -warning: `#[must_use]` on functions is experimental (see issue #43302) - --> $DIR/issue-43106-gating-of-builtin-attrs.rs:663:5 - | -LL | #[must_use = "1400"] fn f() { } - | ^^^^^^^^^^^^^^^^^^^^ - | - = help: add #![feature(fn_must_use)] to the crate attributes to enable - warning: unknown lint: `x5400` --> $DIR/issue-43106-gating-of-builtin-attrs.rs:49:33 | @@ -799,433 +791,433 @@ LL | #[no_std = "2600"] | ^^^^^^^^^^^^^^^^^^ warning: unused attribute - --> $DIR/issue-43106-gating-of-builtin-attrs.rs:692:17 + --> $DIR/issue-43106-gating-of-builtin-attrs.rs:691:17 | LL | mod inner { #![crate_name="0900"] } | ^^^^^^^^^^^^^^^^^^^^^ warning: crate-level attribute should be in the root module - --> $DIR/issue-43106-gating-of-builtin-attrs.rs:692:17 + --> $DIR/issue-43106-gating-of-builtin-attrs.rs:691:17 | LL | mod inner { #![crate_name="0900"] } | ^^^^^^^^^^^^^^^^^^^^^ warning: unused attribute - --> $DIR/issue-43106-gating-of-builtin-attrs.rs:696:5 + --> $DIR/issue-43106-gating-of-builtin-attrs.rs:695:5 | LL | #[crate_name = "0900"] fn f() { } | ^^^^^^^^^^^^^^^^^^^^^^ warning: crate-level attribute should be an inner attribute: add an exclamation mark: #![foo] - --> $DIR/issue-43106-gating-of-builtin-attrs.rs:696:5 + --> $DIR/issue-43106-gating-of-builtin-attrs.rs:695:5 | LL | #[crate_name = "0900"] fn f() { } | ^^^^^^^^^^^^^^^^^^^^^^ warning: unused attribute - --> $DIR/issue-43106-gating-of-builtin-attrs.rs:700:5 + --> $DIR/issue-43106-gating-of-builtin-attrs.rs:699:5 | LL | #[crate_name = "0900"] struct S; | ^^^^^^^^^^^^^^^^^^^^^^ warning: crate-level attribute should be an inner attribute: add an exclamation mark: #![foo] - --> $DIR/issue-43106-gating-of-builtin-attrs.rs:700:5 + --> $DIR/issue-43106-gating-of-builtin-attrs.rs:699:5 | LL | #[crate_name = "0900"] struct S; | ^^^^^^^^^^^^^^^^^^^^^^ warning: unused attribute - --> $DIR/issue-43106-gating-of-builtin-attrs.rs:704:5 + --> $DIR/issue-43106-gating-of-builtin-attrs.rs:703:5 | LL | #[crate_name = "0900"] type T = S; | ^^^^^^^^^^^^^^^^^^^^^^ warning: crate-level attribute should be an inner attribute: add an exclamation mark: #![foo] - --> $DIR/issue-43106-gating-of-builtin-attrs.rs:704:5 + --> $DIR/issue-43106-gating-of-builtin-attrs.rs:703:5 | LL | #[crate_name = "0900"] type T = S; | ^^^^^^^^^^^^^^^^^^^^^^ warning: unused attribute - --> $DIR/issue-43106-gating-of-builtin-attrs.rs:708:5 + --> $DIR/issue-43106-gating-of-builtin-attrs.rs:707:5 | LL | #[crate_name = "0900"] impl S { } | ^^^^^^^^^^^^^^^^^^^^^^ warning: crate-level attribute should be an inner attribute: add an exclamation mark: #![foo] - --> $DIR/issue-43106-gating-of-builtin-attrs.rs:708:5 + --> $DIR/issue-43106-gating-of-builtin-attrs.rs:707:5 | LL | #[crate_name = "0900"] impl S { } | ^^^^^^^^^^^^^^^^^^^^^^ warning: unused attribute - --> $DIR/issue-43106-gating-of-builtin-attrs.rs:688:1 + --> $DIR/issue-43106-gating-of-builtin-attrs.rs:687:1 | LL | #[crate_name = "0900"] | ^^^^^^^^^^^^^^^^^^^^^^ warning: crate-level attribute should be an inner attribute: add an exclamation mark: #![foo] - --> $DIR/issue-43106-gating-of-builtin-attrs.rs:688:1 + --> $DIR/issue-43106-gating-of-builtin-attrs.rs:687:1 | LL | #[crate_name = "0900"] | ^^^^^^^^^^^^^^^^^^^^^^ warning: unused attribute - --> $DIR/issue-43106-gating-of-builtin-attrs.rs:717:17 + --> $DIR/issue-43106-gating-of-builtin-attrs.rs:716:17 | LL | mod inner { #![crate_type="0800"] } | ^^^^^^^^^^^^^^^^^^^^^ warning: crate-level attribute should be in the root module - --> $DIR/issue-43106-gating-of-builtin-attrs.rs:717:17 + --> $DIR/issue-43106-gating-of-builtin-attrs.rs:716:17 | LL | mod inner { #![crate_type="0800"] } | ^^^^^^^^^^^^^^^^^^^^^ warning: unused attribute - --> $DIR/issue-43106-gating-of-builtin-attrs.rs:721:5 + --> $DIR/issue-43106-gating-of-builtin-attrs.rs:720:5 | LL | #[crate_type = "0800"] fn f() { } | ^^^^^^^^^^^^^^^^^^^^^^ warning: crate-level attribute should be an inner attribute: add an exclamation mark: #![foo] - --> $DIR/issue-43106-gating-of-builtin-attrs.rs:721:5 + --> $DIR/issue-43106-gating-of-builtin-attrs.rs:720:5 | LL | #[crate_type = "0800"] fn f() { } | ^^^^^^^^^^^^^^^^^^^^^^ warning: unused attribute - --> $DIR/issue-43106-gating-of-builtin-attrs.rs:725:5 + --> $DIR/issue-43106-gating-of-builtin-attrs.rs:724:5 | LL | #[crate_type = "0800"] struct S; | ^^^^^^^^^^^^^^^^^^^^^^ warning: crate-level attribute should be an inner attribute: add an exclamation mark: #![foo] - --> $DIR/issue-43106-gating-of-builtin-attrs.rs:725:5 + --> $DIR/issue-43106-gating-of-builtin-attrs.rs:724:5 | LL | #[crate_type = "0800"] struct S; | ^^^^^^^^^^^^^^^^^^^^^^ warning: unused attribute - --> $DIR/issue-43106-gating-of-builtin-attrs.rs:729:5 + --> $DIR/issue-43106-gating-of-builtin-attrs.rs:728:5 | LL | #[crate_type = "0800"] type T = S; | ^^^^^^^^^^^^^^^^^^^^^^ warning: crate-level attribute should be an inner attribute: add an exclamation mark: #![foo] - --> $DIR/issue-43106-gating-of-builtin-attrs.rs:729:5 + --> $DIR/issue-43106-gating-of-builtin-attrs.rs:728:5 | LL | #[crate_type = "0800"] type T = S; | ^^^^^^^^^^^^^^^^^^^^^^ warning: unused attribute - --> $DIR/issue-43106-gating-of-builtin-attrs.rs:733:5 + --> $DIR/issue-43106-gating-of-builtin-attrs.rs:732:5 | LL | #[crate_type = "0800"] impl S { } | ^^^^^^^^^^^^^^^^^^^^^^ warning: crate-level attribute should be an inner attribute: add an exclamation mark: #![foo] - --> $DIR/issue-43106-gating-of-builtin-attrs.rs:733:5 + --> $DIR/issue-43106-gating-of-builtin-attrs.rs:732:5 | LL | #[crate_type = "0800"] impl S { } | ^^^^^^^^^^^^^^^^^^^^^^ warning: unused attribute - --> $DIR/issue-43106-gating-of-builtin-attrs.rs:713:1 + --> $DIR/issue-43106-gating-of-builtin-attrs.rs:712:1 | LL | #[crate_type = "0800"] | ^^^^^^^^^^^^^^^^^^^^^^ warning: crate-level attribute should be an inner attribute: add an exclamation mark: #![foo] - --> $DIR/issue-43106-gating-of-builtin-attrs.rs:713:1 + --> $DIR/issue-43106-gating-of-builtin-attrs.rs:712:1 | LL | #[crate_type = "0800"] | ^^^^^^^^^^^^^^^^^^^^^^ warning: unused attribute - --> $DIR/issue-43106-gating-of-builtin-attrs.rs:742:17 + --> $DIR/issue-43106-gating-of-builtin-attrs.rs:741:17 | LL | mod inner { #![feature(x0600)] } | ^^^^^^^^^^^^^^^^^^ warning: crate-level attribute should be in the root module - --> $DIR/issue-43106-gating-of-builtin-attrs.rs:742:17 + --> $DIR/issue-43106-gating-of-builtin-attrs.rs:741:17 | LL | mod inner { #![feature(x0600)] } | ^^^^^^^^^^^^^^^^^^ warning: unused attribute - --> $DIR/issue-43106-gating-of-builtin-attrs.rs:746:5 + --> $DIR/issue-43106-gating-of-builtin-attrs.rs:745:5 | LL | #[feature(x0600)] fn f() { } | ^^^^^^^^^^^^^^^^^ warning: crate-level attribute should be an inner attribute: add an exclamation mark: #![foo] - --> $DIR/issue-43106-gating-of-builtin-attrs.rs:746:5 + --> $DIR/issue-43106-gating-of-builtin-attrs.rs:745:5 | LL | #[feature(x0600)] fn f() { } | ^^^^^^^^^^^^^^^^^ warning: unused attribute - --> $DIR/issue-43106-gating-of-builtin-attrs.rs:750:5 + --> $DIR/issue-43106-gating-of-builtin-attrs.rs:749:5 | LL | #[feature(x0600)] struct S; | ^^^^^^^^^^^^^^^^^ warning: crate-level attribute should be an inner attribute: add an exclamation mark: #![foo] - --> $DIR/issue-43106-gating-of-builtin-attrs.rs:750:5 + --> $DIR/issue-43106-gating-of-builtin-attrs.rs:749:5 | LL | #[feature(x0600)] struct S; | ^^^^^^^^^^^^^^^^^ warning: unused attribute - --> $DIR/issue-43106-gating-of-builtin-attrs.rs:754:5 + --> $DIR/issue-43106-gating-of-builtin-attrs.rs:753:5 | LL | #[feature(x0600)] type T = S; | ^^^^^^^^^^^^^^^^^ warning: crate-level attribute should be an inner attribute: add an exclamation mark: #![foo] - --> $DIR/issue-43106-gating-of-builtin-attrs.rs:754:5 + --> $DIR/issue-43106-gating-of-builtin-attrs.rs:753:5 | LL | #[feature(x0600)] type T = S; | ^^^^^^^^^^^^^^^^^ warning: unused attribute - --> $DIR/issue-43106-gating-of-builtin-attrs.rs:758:5 + --> $DIR/issue-43106-gating-of-builtin-attrs.rs:757:5 | LL | #[feature(x0600)] impl S { } | ^^^^^^^^^^^^^^^^^ warning: crate-level attribute should be an inner attribute: add an exclamation mark: #![foo] - --> $DIR/issue-43106-gating-of-builtin-attrs.rs:758:5 + --> $DIR/issue-43106-gating-of-builtin-attrs.rs:757:5 | LL | #[feature(x0600)] impl S { } | ^^^^^^^^^^^^^^^^^ warning: unused attribute - --> $DIR/issue-43106-gating-of-builtin-attrs.rs:738:1 + --> $DIR/issue-43106-gating-of-builtin-attrs.rs:737:1 | LL | #[feature(x0600)] | ^^^^^^^^^^^^^^^^^ warning: crate-level attribute should be an inner attribute: add an exclamation mark: #![foo] - --> $DIR/issue-43106-gating-of-builtin-attrs.rs:738:1 + --> $DIR/issue-43106-gating-of-builtin-attrs.rs:737:1 | LL | #[feature(x0600)] | ^^^^^^^^^^^^^^^^^ warning: unused attribute - --> $DIR/issue-43106-gating-of-builtin-attrs.rs:768:17 + --> $DIR/issue-43106-gating-of-builtin-attrs.rs:767:17 | LL | mod inner { #![no_main="0400"] } | ^^^^^^^^^^^^^^^^^^ warning: crate-level attribute should be in the root module - --> $DIR/issue-43106-gating-of-builtin-attrs.rs:768:17 + --> $DIR/issue-43106-gating-of-builtin-attrs.rs:767:17 | LL | mod inner { #![no_main="0400"] } | ^^^^^^^^^^^^^^^^^^ warning: unused attribute - --> $DIR/issue-43106-gating-of-builtin-attrs.rs:772:5 + --> $DIR/issue-43106-gating-of-builtin-attrs.rs:771:5 | LL | #[no_main = "0400"] fn f() { } | ^^^^^^^^^^^^^^^^^^^ warning: crate-level attribute should be an inner attribute: add an exclamation mark: #![foo] - --> $DIR/issue-43106-gating-of-builtin-attrs.rs:772:5 + --> $DIR/issue-43106-gating-of-builtin-attrs.rs:771:5 | LL | #[no_main = "0400"] fn f() { } | ^^^^^^^^^^^^^^^^^^^ warning: unused attribute - --> $DIR/issue-43106-gating-of-builtin-attrs.rs:776:5 + --> $DIR/issue-43106-gating-of-builtin-attrs.rs:775:5 | LL | #[no_main = "0400"] struct S; | ^^^^^^^^^^^^^^^^^^^ warning: crate-level attribute should be an inner attribute: add an exclamation mark: #![foo] - --> $DIR/issue-43106-gating-of-builtin-attrs.rs:776:5 + --> $DIR/issue-43106-gating-of-builtin-attrs.rs:775:5 | LL | #[no_main = "0400"] struct S; | ^^^^^^^^^^^^^^^^^^^ warning: unused attribute - --> $DIR/issue-43106-gating-of-builtin-attrs.rs:780:5 + --> $DIR/issue-43106-gating-of-builtin-attrs.rs:779:5 | LL | #[no_main = "0400"] type T = S; | ^^^^^^^^^^^^^^^^^^^ warning: crate-level attribute should be an inner attribute: add an exclamation mark: #![foo] - --> $DIR/issue-43106-gating-of-builtin-attrs.rs:780:5 + --> $DIR/issue-43106-gating-of-builtin-attrs.rs:779:5 | LL | #[no_main = "0400"] type T = S; | ^^^^^^^^^^^^^^^^^^^ warning: unused attribute - --> $DIR/issue-43106-gating-of-builtin-attrs.rs:784:5 + --> $DIR/issue-43106-gating-of-builtin-attrs.rs:783:5 | LL | #[no_main = "0400"] impl S { } | ^^^^^^^^^^^^^^^^^^^ warning: crate-level attribute should be an inner attribute: add an exclamation mark: #![foo] - --> $DIR/issue-43106-gating-of-builtin-attrs.rs:784:5 + --> $DIR/issue-43106-gating-of-builtin-attrs.rs:783:5 | LL | #[no_main = "0400"] impl S { } | ^^^^^^^^^^^^^^^^^^^ warning: unused attribute - --> $DIR/issue-43106-gating-of-builtin-attrs.rs:764:1 + --> $DIR/issue-43106-gating-of-builtin-attrs.rs:763:1 | LL | #[no_main = "0400"] | ^^^^^^^^^^^^^^^^^^^ warning: crate-level attribute should be an inner attribute: add an exclamation mark: #![foo] - --> $DIR/issue-43106-gating-of-builtin-attrs.rs:764:1 + --> $DIR/issue-43106-gating-of-builtin-attrs.rs:763:1 | LL | #[no_main = "0400"] | ^^^^^^^^^^^^^^^^^^^ warning: unused attribute - --> $DIR/issue-43106-gating-of-builtin-attrs.rs:806:17 + --> $DIR/issue-43106-gating-of-builtin-attrs.rs:805:17 | LL | mod inner { #![recursion_limit="0200"] } | ^^^^^^^^^^^^^^^^^^^^^^^^^^ warning: crate-level attribute should be in the root module - --> $DIR/issue-43106-gating-of-builtin-attrs.rs:806:17 + --> $DIR/issue-43106-gating-of-builtin-attrs.rs:805:17 | LL | mod inner { #![recursion_limit="0200"] } | ^^^^^^^^^^^^^^^^^^^^^^^^^^ warning: unused attribute - --> $DIR/issue-43106-gating-of-builtin-attrs.rs:810:5 + --> $DIR/issue-43106-gating-of-builtin-attrs.rs:809:5 | LL | #[recursion_limit="0200"] fn f() { } | ^^^^^^^^^^^^^^^^^^^^^^^^^ warning: crate-level attribute should be an inner attribute: add an exclamation mark: #![foo] - --> $DIR/issue-43106-gating-of-builtin-attrs.rs:810:5 + --> $DIR/issue-43106-gating-of-builtin-attrs.rs:809:5 | LL | #[recursion_limit="0200"] fn f() { } | ^^^^^^^^^^^^^^^^^^^^^^^^^ warning: unused attribute - --> $DIR/issue-43106-gating-of-builtin-attrs.rs:814:5 + --> $DIR/issue-43106-gating-of-builtin-attrs.rs:813:5 | LL | #[recursion_limit="0200"] struct S; | ^^^^^^^^^^^^^^^^^^^^^^^^^ warning: crate-level attribute should be an inner attribute: add an exclamation mark: #![foo] - --> $DIR/issue-43106-gating-of-builtin-attrs.rs:814:5 + --> $DIR/issue-43106-gating-of-builtin-attrs.rs:813:5 | LL | #[recursion_limit="0200"] struct S; | ^^^^^^^^^^^^^^^^^^^^^^^^^ warning: unused attribute - --> $DIR/issue-43106-gating-of-builtin-attrs.rs:818:5 + --> $DIR/issue-43106-gating-of-builtin-attrs.rs:817:5 | LL | #[recursion_limit="0200"] type T = S; | ^^^^^^^^^^^^^^^^^^^^^^^^^ warning: crate-level attribute should be an inner attribute: add an exclamation mark: #![foo] - --> $DIR/issue-43106-gating-of-builtin-attrs.rs:818:5 + --> $DIR/issue-43106-gating-of-builtin-attrs.rs:817:5 | LL | #[recursion_limit="0200"] type T = S; | ^^^^^^^^^^^^^^^^^^^^^^^^^ warning: unused attribute - --> $DIR/issue-43106-gating-of-builtin-attrs.rs:822:5 + --> $DIR/issue-43106-gating-of-builtin-attrs.rs:821:5 | LL | #[recursion_limit="0200"] impl S { } | ^^^^^^^^^^^^^^^^^^^^^^^^^ warning: crate-level attribute should be an inner attribute: add an exclamation mark: #![foo] - --> $DIR/issue-43106-gating-of-builtin-attrs.rs:822:5 + --> $DIR/issue-43106-gating-of-builtin-attrs.rs:821:5 | LL | #[recursion_limit="0200"] impl S { } | ^^^^^^^^^^^^^^^^^^^^^^^^^ warning: unused attribute - --> $DIR/issue-43106-gating-of-builtin-attrs.rs:802:1 + --> $DIR/issue-43106-gating-of-builtin-attrs.rs:801:1 | LL | #[recursion_limit="0200"] | ^^^^^^^^^^^^^^^^^^^^^^^^^ warning: crate-level attribute should be an inner attribute: add an exclamation mark: #![foo] - --> $DIR/issue-43106-gating-of-builtin-attrs.rs:802:1 + --> $DIR/issue-43106-gating-of-builtin-attrs.rs:801:1 | LL | #[recursion_limit="0200"] | ^^^^^^^^^^^^^^^^^^^^^^^^^ warning: unused attribute - --> $DIR/issue-43106-gating-of-builtin-attrs.rs:831:17 + --> $DIR/issue-43106-gating-of-builtin-attrs.rs:830:17 | LL | mod inner { #![type_length_limit="0100"] } | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ warning: crate-level attribute should be in the root module - --> $DIR/issue-43106-gating-of-builtin-attrs.rs:831:17 + --> $DIR/issue-43106-gating-of-builtin-attrs.rs:830:17 | LL | mod inner { #![type_length_limit="0100"] } | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ warning: unused attribute - --> $DIR/issue-43106-gating-of-builtin-attrs.rs:835:5 + --> $DIR/issue-43106-gating-of-builtin-attrs.rs:834:5 | LL | #[type_length_limit="0100"] fn f() { } | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ warning: crate-level attribute should be an inner attribute: add an exclamation mark: #![foo] - --> $DIR/issue-43106-gating-of-builtin-attrs.rs:835:5 + --> $DIR/issue-43106-gating-of-builtin-attrs.rs:834:5 | LL | #[type_length_limit="0100"] fn f() { } | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ warning: unused attribute - --> $DIR/issue-43106-gating-of-builtin-attrs.rs:839:5 + --> $DIR/issue-43106-gating-of-builtin-attrs.rs:838:5 | LL | #[type_length_limit="0100"] struct S; | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ warning: crate-level attribute should be an inner attribute: add an exclamation mark: #![foo] - --> $DIR/issue-43106-gating-of-builtin-attrs.rs:839:5 + --> $DIR/issue-43106-gating-of-builtin-attrs.rs:838:5 | LL | #[type_length_limit="0100"] struct S; | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ warning: unused attribute - --> $DIR/issue-43106-gating-of-builtin-attrs.rs:843:5 + --> $DIR/issue-43106-gating-of-builtin-attrs.rs:842:5 | LL | #[type_length_limit="0100"] type T = S; | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ warning: crate-level attribute should be an inner attribute: add an exclamation mark: #![foo] - --> $DIR/issue-43106-gating-of-builtin-attrs.rs:843:5 + --> $DIR/issue-43106-gating-of-builtin-attrs.rs:842:5 | LL | #[type_length_limit="0100"] type T = S; | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ warning: unused attribute - --> $DIR/issue-43106-gating-of-builtin-attrs.rs:847:5 + --> $DIR/issue-43106-gating-of-builtin-attrs.rs:846:5 | LL | #[type_length_limit="0100"] impl S { } | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ warning: crate-level attribute should be an inner attribute: add an exclamation mark: #![foo] - --> $DIR/issue-43106-gating-of-builtin-attrs.rs:847:5 + --> $DIR/issue-43106-gating-of-builtin-attrs.rs:846:5 | LL | #[type_length_limit="0100"] impl S { } | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ warning: unused attribute - --> $DIR/issue-43106-gating-of-builtin-attrs.rs:827:1 + --> $DIR/issue-43106-gating-of-builtin-attrs.rs:826:1 | LL | #[type_length_limit="0100"] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ warning: crate-level attribute should be an inner attribute: add an exclamation mark: #![foo] - --> $DIR/issue-43106-gating-of-builtin-attrs.rs:827:1 + --> $DIR/issue-43106-gating-of-builtin-attrs.rs:826:1 | LL | #[type_length_limit="0100"] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ @@ -1309,7 +1301,7 @@ LL | #![proc_macro_derive = "2500"] //~ WARN unused attribute | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ error: compilation successful - --> $DIR/issue-43106-gating-of-builtin-attrs.rs:858:1 + --> $DIR/issue-43106-gating-of-builtin-attrs.rs:857:1 | LL | / fn main() { //~ ERROR compilation successful LL | | println!("Hello World"); diff --git a/src/test/ui/fn_must_use.rs b/src/test/ui/fn_must_use.rs new file mode 100644 index 00000000000..def23046db2 --- /dev/null +++ b/src/test/ui/fn_must_use.rs @@ -0,0 +1,78 @@ +// Copyright 2017 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. + +// compile-pass + +#![warn(unused_must_use)] + +#[derive(PartialEq, Eq)] +struct MyStruct { + n: usize, +} + +impl MyStruct { + #[must_use] + fn need_to_use_this_method_value(&self) -> usize { + self.n + } +} + +trait EvenNature { + #[must_use = "no side effects"] + fn is_even(&self) -> bool; +} + +impl EvenNature for MyStruct { + fn is_even(&self) -> bool { + self.n % 2 == 0 + } +} + +trait Replaceable { + fn replace(&mut self, substitute: usize) -> usize; +} + +impl Replaceable for MyStruct { + // ↓ N.b.: `#[must_use]` attribute on a particular trait implementation + // method won't work; the attribute should be on the method signature in + // the trait's definition. + #[must_use] + fn replace(&mut self, substitute: usize) -> usize { + let previously = self.n; + self.n = substitute; + previously + } +} + +#[must_use = "it's important"] +fn need_to_use_this_value() -> bool { + false +} + +fn main() { + need_to_use_this_value(); //~ WARN unused return value + + let mut m = MyStruct { n: 2 }; + let n = MyStruct { n: 3 }; + + m.need_to_use_this_method_value(); //~ WARN unused return value + m.is_even(); // trait method! + //~^ WARN unused return value + + m.replace(3); // won't warn (annotation needs to be in trait definition) + + // comparison methods are `must_use` + 2.eq(&3); //~ WARN unused return value + m.eq(&n); //~ WARN unused return value + + // lint includes comparison operators + 2 == 3; //~ WARN unused comparison + m == n; //~ WARN unused comparison +} diff --git a/src/test/ui/fn_must_use.stderr b/src/test/ui/fn_must_use.stderr new file mode 100644 index 00000000000..5026dac0a94 --- /dev/null +++ b/src/test/ui/fn_must_use.stderr @@ -0,0 +1,48 @@ +warning: unused return value of `need_to_use_this_value` which must be used: it's important + --> $DIR/fn_must_use.rs:60:5 + | +LL | need_to_use_this_value(); //~ WARN unused return value + | ^^^^^^^^^^^^^^^^^^^^^^^^^ + | +note: lint level defined here + --> $DIR/fn_must_use.rs:13:9 + | +LL | #![warn(unused_must_use)] + | ^^^^^^^^^^^^^^^ + +warning: unused return value of `MyStruct::need_to_use_this_method_value` which must be used + --> $DIR/fn_must_use.rs:65:5 + | +LL | m.need_to_use_this_method_value(); //~ WARN unused return value + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +warning: unused return value of `EvenNature::is_even` which must be used: no side effects + --> $DIR/fn_must_use.rs:66:5 + | +LL | m.is_even(); // trait method! + | ^^^^^^^^^^^^ + +warning: unused return value of `std::cmp::PartialEq::eq` which must be used + --> $DIR/fn_must_use.rs:72:5 + | +LL | 2.eq(&3); //~ WARN unused return value + | ^^^^^^^^^ + +warning: unused return value of `std::cmp::PartialEq::eq` which must be used + --> $DIR/fn_must_use.rs:73:5 + | +LL | m.eq(&n); //~ WARN unused return value + | ^^^^^^^^^ + +warning: unused comparison which must be used + --> $DIR/fn_must_use.rs:76:5 + | +LL | 2 == 3; //~ WARN unused comparison + | ^^^^^^ + +warning: unused comparison which must be used + --> $DIR/fn_must_use.rs:77:5 + | +LL | m == n; //~ WARN unused comparison + | ^^^^^^ + diff --git a/src/test/ui/lint/must-use-ops.rs b/src/test/ui/lint/must-use-ops.rs index 4ed82ab3b40..c0575f817c8 100644 --- a/src/test/ui/lint/must-use-ops.rs +++ b/src/test/ui/lint/must-use-ops.rs @@ -12,7 +12,6 @@ // compile-pass -#![feature(fn_must_use)] #![warn(unused_must_use)] fn main() { diff --git a/src/test/ui/lint/must-use-ops.stderr b/src/test/ui/lint/must-use-ops.stderr index f444ef09075..5703536ef48 100644 --- a/src/test/ui/lint/must-use-ops.stderr +++ b/src/test/ui/lint/must-use-ops.stderr @@ -1,131 +1,131 @@ warning: unused comparison which must be used - --> $DIR/must-use-ops.rs:23:5 + --> $DIR/must-use-ops.rs:22:5 | LL | val == 1; | ^^^^^^^^ | note: lint level defined here - --> $DIR/must-use-ops.rs:16:9 + --> $DIR/must-use-ops.rs:15:9 | LL | #![warn(unused_must_use)] | ^^^^^^^^^^^^^^^ warning: unused comparison which must be used - --> $DIR/must-use-ops.rs:24:5 + --> $DIR/must-use-ops.rs:23:5 | LL | val < 1; | ^^^^^^^ warning: unused comparison which must be used - --> $DIR/must-use-ops.rs:25:5 + --> $DIR/must-use-ops.rs:24:5 | LL | val <= 1; | ^^^^^^^^ warning: unused comparison which must be used - --> $DIR/must-use-ops.rs:26:5 + --> $DIR/must-use-ops.rs:25:5 | LL | val != 1; | ^^^^^^^^ warning: unused comparison which must be used - --> $DIR/must-use-ops.rs:27:5 + --> $DIR/must-use-ops.rs:26:5 | LL | val >= 1; | ^^^^^^^^ warning: unused comparison which must be used - --> $DIR/must-use-ops.rs:28:5 + --> $DIR/must-use-ops.rs:27:5 | LL | val > 1; | ^^^^^^^ warning: unused arithmetic operation which must be used - --> $DIR/must-use-ops.rs:31:5 + --> $DIR/must-use-ops.rs:30:5 | LL | val + 2; | ^^^^^^^ warning: unused arithmetic operation which must be used - --> $DIR/must-use-ops.rs:32:5 + --> $DIR/must-use-ops.rs:31:5 | LL | val - 2; | ^^^^^^^ warning: unused arithmetic operation which must be used - --> $DIR/must-use-ops.rs:33:5 + --> $DIR/must-use-ops.rs:32:5 | LL | val / 2; | ^^^^^^^ warning: unused arithmetic operation which must be used - --> $DIR/must-use-ops.rs:34:5 + --> $DIR/must-use-ops.rs:33:5 | LL | val * 2; | ^^^^^^^ warning: unused arithmetic operation which must be used - --> $DIR/must-use-ops.rs:35:5 + --> $DIR/must-use-ops.rs:34:5 | LL | val % 2; | ^^^^^^^ warning: unused logical operation which must be used - --> $DIR/must-use-ops.rs:38:5 + --> $DIR/must-use-ops.rs:37:5 | LL | true && true; | ^^^^^^^^^^^^ warning: unused logical operation which must be used - --> $DIR/must-use-ops.rs:39:5 + --> $DIR/must-use-ops.rs:38:5 | LL | false || true; | ^^^^^^^^^^^^^ warning: unused bitwise operation which must be used - --> $DIR/must-use-ops.rs:42:5 + --> $DIR/must-use-ops.rs:41:5 | LL | 5 ^ val; | ^^^^^^^ warning: unused bitwise operation which must be used - --> $DIR/must-use-ops.rs:43:5 + --> $DIR/must-use-ops.rs:42:5 | LL | 5 & val; | ^^^^^^^ warning: unused bitwise operation which must be used - --> $DIR/must-use-ops.rs:44:5 + --> $DIR/must-use-ops.rs:43:5 | LL | 5 | val; | ^^^^^^^ warning: unused bitwise operation which must be used - --> $DIR/must-use-ops.rs:45:5 + --> $DIR/must-use-ops.rs:44:5 | LL | 5 << val; | ^^^^^^^^ warning: unused bitwise operation which must be used - --> $DIR/must-use-ops.rs:46:5 + --> $DIR/must-use-ops.rs:45:5 | LL | 5 >> val; | ^^^^^^^^ warning: unused unary operation which must be used - --> $DIR/must-use-ops.rs:49:5 + --> $DIR/must-use-ops.rs:48:5 | LL | !val; | ^^^^ warning: unused unary operation which must be used - --> $DIR/must-use-ops.rs:50:5 + --> $DIR/must-use-ops.rs:49:5 | LL | -val; | ^^^^ warning: unused unary operation which must be used - --> $DIR/must-use-ops.rs:51:5 + --> $DIR/must-use-ops.rs:50:5 | LL | *val_pointer; | ^^^^^^^^^^^^ diff --git a/src/test/ui/rfc_1940-must_use_on_functions/fn_must_use.rs b/src/test/ui/rfc_1940-must_use_on_functions/fn_must_use.rs deleted file mode 100644 index d20ebf0b740..00000000000 --- a/src/test/ui/rfc_1940-must_use_on_functions/fn_must_use.rs +++ /dev/null @@ -1,79 +0,0 @@ -// Copyright 2017 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. - -// compile-pass - -#![feature(fn_must_use)] -#![warn(unused_must_use)] - -#[derive(PartialEq, Eq)] -struct MyStruct { - n: usize, -} - -impl MyStruct { - #[must_use] - fn need_to_use_this_method_value(&self) -> usize { - self.n - } -} - -trait EvenNature { - #[must_use = "no side effects"] - fn is_even(&self) -> bool; -} - -impl EvenNature for MyStruct { - fn is_even(&self) -> bool { - self.n % 2 == 0 - } -} - -trait Replaceable { - fn replace(&mut self, substitute: usize) -> usize; -} - -impl Replaceable for MyStruct { - // ↓ N.b.: `#[must_use]` attribute on a particular trait implementation - // method won't work; the attribute should be on the method signature in - // the trait's definition. - #[must_use] - fn replace(&mut self, substitute: usize) -> usize { - let previously = self.n; - self.n = substitute; - previously - } -} - -#[must_use = "it's important"] -fn need_to_use_this_value() -> bool { - false -} - -fn main() { - need_to_use_this_value(); //~ WARN unused return value - - let mut m = MyStruct { n: 2 }; - let n = MyStruct { n: 3 }; - - m.need_to_use_this_method_value(); //~ WARN unused return value - m.is_even(); // trait method! - //~^ WARN unused return value - - m.replace(3); // won't warn (annotation needs to be in trait definition) - - // comparison methods are `must_use` - 2.eq(&3); //~ WARN unused return value - m.eq(&n); //~ WARN unused return value - - // lint includes comparison operators - 2 == 3; //~ WARN unused comparison - m == n; //~ WARN unused comparison -} diff --git a/src/test/ui/rfc_1940-must_use_on_functions/fn_must_use.stderr b/src/test/ui/rfc_1940-must_use_on_functions/fn_must_use.stderr deleted file mode 100644 index d0a8bb525b6..00000000000 --- a/src/test/ui/rfc_1940-must_use_on_functions/fn_must_use.stderr +++ /dev/null @@ -1,48 +0,0 @@ -warning: unused return value of `need_to_use_this_value` which must be used: it's important - --> $DIR/fn_must_use.rs:61:5 - | -LL | need_to_use_this_value(); //~ WARN unused return value - | ^^^^^^^^^^^^^^^^^^^^^^^^^ - | -note: lint level defined here - --> $DIR/fn_must_use.rs:14:9 - | -LL | #![warn(unused_must_use)] - | ^^^^^^^^^^^^^^^ - -warning: unused return value of `MyStruct::need_to_use_this_method_value` which must be used - --> $DIR/fn_must_use.rs:66:5 - | -LL | m.need_to_use_this_method_value(); //~ WARN unused return value - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ - -warning: unused return value of `EvenNature::is_even` which must be used: no side effects - --> $DIR/fn_must_use.rs:67:5 - | -LL | m.is_even(); // trait method! - | ^^^^^^^^^^^^ - -warning: unused return value of `std::cmp::PartialEq::eq` which must be used - --> $DIR/fn_must_use.rs:73:5 - | -LL | 2.eq(&3); //~ WARN unused return value - | ^^^^^^^^^ - -warning: unused return value of `std::cmp::PartialEq::eq` which must be used - --> $DIR/fn_must_use.rs:74:5 - | -LL | m.eq(&n); //~ WARN unused return value - | ^^^^^^^^^ - -warning: unused comparison which must be used - --> $DIR/fn_must_use.rs:77:5 - | -LL | 2 == 3; //~ WARN unused comparison - | ^^^^^^ - -warning: unused comparison which must be used - --> $DIR/fn_must_use.rs:78:5 - | -LL | m == n; //~ WARN unused comparison - | ^^^^^^ - diff --git a/src/test/ui/span/gated-features-attr-spans.rs b/src/test/ui/span/gated-features-attr-spans.rs index 83a4c5d5dd2..eff1f98eb71 100644 --- a/src/test/ui/span/gated-features-attr-spans.rs +++ b/src/test/ui/span/gated-features-attr-spans.rs @@ -8,33 +8,10 @@ // option. This file may not be copied, modified, or distributed // except according to those terms. -#![feature(attr_literals)] - -#[repr(align(16))] -struct Gem { - mohs_hardness: u8, - poofed: bool, - weapon: Weapon, -} - #[repr(simd)] //~ ERROR are experimental struct Weapon { name: String, damage: u32 } -impl Gem { - #[must_use] fn summon_weapon(&self) -> Weapon { self.weapon } - //~^ WARN is experimental -} - -#[must_use] //~ WARN is experimental -fn bubble(gem: Gem) -> Result { - if gem.poofed { - Ok(gem) - } else { - Err(()) - } -} - fn main() {} diff --git a/src/test/ui/span/gated-features-attr-spans.stderr b/src/test/ui/span/gated-features-attr-spans.stderr index 179daf83c3c..a99530529fc 100644 --- a/src/test/ui/span/gated-features-attr-spans.stderr +++ b/src/test/ui/span/gated-features-attr-spans.stderr @@ -1,27 +1,11 @@ error[E0658]: SIMD types are experimental and possibly buggy (see issue #27731) - --> $DIR/gated-features-attr-spans.rs:20:1 + --> $DIR/gated-features-attr-spans.rs:11:1 | LL | #[repr(simd)] //~ ERROR are experimental | ^^^^^^^^^^^^^ | = help: add #![feature(repr_simd)] to the crate attributes to enable -warning: `#[must_use]` on methods is experimental (see issue #43302) - --> $DIR/gated-features-attr-spans.rs:27:5 - | -LL | #[must_use] fn summon_weapon(&self) -> Weapon { self.weapon } - | ^^^^^^^^^^^ - | - = help: add #![feature(fn_must_use)] to the crate attributes to enable - -warning: `#[must_use]` on functions is experimental (see issue #43302) - --> $DIR/gated-features-attr-spans.rs:31:1 - | -LL | #[must_use] //~ WARN is experimental - | ^^^^^^^^^^^ - | - = help: add #![feature(fn_must_use)] to the crate attributes to enable - error: aborting due to previous error For more information about this error, try `rustc --explain E0658`. -- cgit 1.4.1-3-g733a5 From f8b774fbf1f57e520b58ae3828e4b3a1ddf1d97c Mon Sep 17 00:00:00 2001 From: Manish Goregaokar Date: Mon, 7 May 2018 09:27:50 -0700 Subject: Add explanation for #[must_use] on mutex guards --- src/libstd/sync/mutex.rs | 2 +- src/libstd/sync/rwlock.rs | 4 ++-- src/libstd/sys_common/remutex.rs | 2 +- 3 files changed, 4 insertions(+), 4 deletions(-) (limited to 'src/libstd/sync') diff --git a/src/libstd/sync/mutex.rs b/src/libstd/sync/mutex.rs index 3b4904c98e8..f3503b0b3a6 100644 --- a/src/libstd/sync/mutex.rs +++ b/src/libstd/sync/mutex.rs @@ -150,7 +150,7 @@ unsafe impl Sync for Mutex { } /// [`lock`]: struct.Mutex.html#method.lock /// [`try_lock`]: struct.Mutex.html#method.try_lock /// [`Mutex`]: struct.Mutex.html -#[must_use] +#[must_use = "if unused the Mutex will immediately unlock"] #[stable(feature = "rust1", since = "1.0.0")] pub struct MutexGuard<'a, T: ?Sized + 'a> { // funny underscores due to how Deref/DerefMut currently work (they diff --git a/src/libstd/sync/rwlock.rs b/src/libstd/sync/rwlock.rs index f7fdedc0d21..e3db60cff84 100644 --- a/src/libstd/sync/rwlock.rs +++ b/src/libstd/sync/rwlock.rs @@ -94,7 +94,7 @@ unsafe impl Sync for RwLock {} /// [`read`]: struct.RwLock.html#method.read /// [`try_read`]: struct.RwLock.html#method.try_read /// [`RwLock`]: struct.RwLock.html -#[must_use] +#[must_use = "if unused the RwLock will immediately unlock"] #[stable(feature = "rust1", since = "1.0.0")] pub struct RwLockReadGuard<'a, T: ?Sized + 'a> { __lock: &'a RwLock, @@ -115,7 +115,7 @@ unsafe impl<'a, T: ?Sized + Sync> Sync for RwLockReadGuard<'a, T> {} /// [`write`]: struct.RwLock.html#method.write /// [`try_write`]: struct.RwLock.html#method.try_write /// [`RwLock`]: struct.RwLock.html -#[must_use] +#[must_use = "if unused the RwLock will immediately unlock"] #[stable(feature = "rust1", since = "1.0.0")] pub struct RwLockWriteGuard<'a, T: ?Sized + 'a> { __lock: &'a RwLock, diff --git a/src/libstd/sys_common/remutex.rs b/src/libstd/sys_common/remutex.rs index ce43ec6d9ab..022056f8a8a 100644 --- a/src/libstd/sys_common/remutex.rs +++ b/src/libstd/sys_common/remutex.rs @@ -41,7 +41,7 @@ unsafe impl Sync for ReentrantMutex {} /// because implementation of the trait would violate Rust’s reference aliasing /// rules. Use interior mutability (usually `RefCell`) in order to mutate the /// guarded data. -#[must_use] +#[must_use = "if unused the ReentrantMutex will immediately unlock"] pub struct ReentrantMutexGuard<'a, T: 'a> { // funny underscores due to how Deref currently works (it disregards field // privacy). -- cgit 1.4.1-3-g733a5 From 1c2abda671ace3935a70b9d4c44bf944e1d34189 Mon Sep 17 00:00:00 2001 From: Tobias Bucher Date: Thu, 24 May 2018 14:08:47 +0200 Subject: Add `Once::new` as a way of constructing a `Once` --- src/libstd/sync/once.rs | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'src/libstd/sync') diff --git a/src/libstd/sync/once.rs b/src/libstd/sync/once.rs index 6fd8b6a5bba..138993e2271 100644 --- a/src/libstd/sync/once.rs +++ b/src/libstd/sync/once.rs @@ -73,9 +73,10 @@ use thread::{self, Thread}; /// A synchronization primitive which can be used to run a one-time global /// initialization. Useful for one-time initialization for FFI or related /// functionality. This type can only be constructed with the [`ONCE_INIT`] -/// value. +/// value or the equivalent [`Once::new`] constructor. /// /// [`ONCE_INIT`]: constant.ONCE_INIT.html +/// [`Once::new`]: struct.Once.html#method.new /// /// # Examples /// -- cgit 1.4.1-3-g733a5 From 2a900e2b84f33a10ef810d6e986fc3d3be0c432d Mon Sep 17 00:00:00 2001 From: Tobias Bucher Date: Thu, 24 May 2018 14:09:42 +0200 Subject: Update the `Once` docs to use `Once::new` --- src/libstd/sync/once.rs | 20 ++++++++++---------- 1 file changed, 10 insertions(+), 10 deletions(-) (limited to 'src/libstd/sync') diff --git a/src/libstd/sync/once.rs b/src/libstd/sync/once.rs index 138993e2271..7eb7be23128 100644 --- a/src/libstd/sync/once.rs +++ b/src/libstd/sync/once.rs @@ -81,9 +81,9 @@ use thread::{self, Thread}; /// # Examples /// /// ``` -/// use std::sync::{Once, ONCE_INIT}; +/// use std::sync::Once; /// -/// static START: Once = ONCE_INIT; +/// static START: Once = Once::new(); /// /// START.call_once(|| { /// // run initialization here @@ -181,10 +181,10 @@ impl Once { /// # Examples /// /// ``` - /// use std::sync::{Once, ONCE_INIT}; + /// use std::sync::Once; /// /// static mut VAL: usize = 0; - /// static INIT: Once = ONCE_INIT; + /// static INIT: Once = Once::new(); /// /// // Accessing a `static mut` is unsafe much of the time, but if we do so /// // in a synchronized fashion (e.g. write once or read all) then we're @@ -249,10 +249,10 @@ impl Once { /// ``` /// #![feature(once_poison)] /// - /// use std::sync::{Once, ONCE_INIT}; + /// use std::sync::Once; /// use std::thread; /// - /// static INIT: Once = ONCE_INIT; + /// static INIT: Once = Once::new(); /// /// // poison the once /// let handle = thread::spawn(|| { @@ -432,10 +432,10 @@ impl OnceState { /// ``` /// #![feature(once_poison)] /// - /// use std::sync::{Once, ONCE_INIT}; + /// use std::sync::Once; /// use std::thread; /// - /// static INIT: Once = ONCE_INIT; + /// static INIT: Once = Once::new(); /// /// // poison the once /// let handle = thread::spawn(|| { @@ -453,9 +453,9 @@ impl OnceState { /// ``` /// #![feature(once_poison)] /// - /// use std::sync::{Once, ONCE_INIT}; + /// use std::sync::Once; /// - /// static INIT: Once = ONCE_INIT; + /// static INIT: Once = Once::new(); /// /// INIT.call_once_force(|state| { /// assert!(!state.poisoned()); -- cgit 1.4.1-3-g733a5 From b81da278623d9dcda1776008612bd42e1922e9c3 Mon Sep 17 00:00:00 2001 From: "NODA, Kai" Date: Sat, 9 Jun 2018 21:13:04 +0800 Subject: libstd: add an RAII utility for sys_common::mutex::Mutex Signed-off-by: NODA, Kai --- src/libstd/io/lazy.rs | 21 +++++++++++---------- src/libstd/sync/mutex.rs | 4 ++-- src/libstd/sys/redox/args.rs | 16 ++++++---------- src/libstd/sys/unix/args.rs | 14 +++++--------- src/libstd/sys/unix/os.rs | 26 +++++++++----------------- src/libstd/sys_common/at_exit_imp.rs | 27 ++++++++++++++------------- src/libstd/sys_common/mutex.rs | 26 ++++++++++++++++++++++++-- src/libstd/sys_common/thread_local.rs | 3 +-- src/libstd/thread/mod.rs | 5 +---- 9 files changed, 73 insertions(+), 69 deletions(-) (limited to 'src/libstd/sync') diff --git a/src/libstd/io/lazy.rs b/src/libstd/io/lazy.rs index 9cef4e3cdf1..d357966be92 100644 --- a/src/libstd/io/lazy.rs +++ b/src/libstd/io/lazy.rs @@ -20,6 +20,9 @@ pub struct Lazy { init: fn() -> Arc, } +#[inline] +const fn done() -> *mut Arc { 1_usize as *mut _ } + unsafe impl Sync for Lazy {} impl Lazy { @@ -33,17 +36,15 @@ impl Lazy { pub fn get(&'static self) -> Option> { unsafe { - self.lock.lock(); + let _guard = self.lock.lock(); let ptr = self.ptr.get(); - let ret = if ptr.is_null() { + if ptr.is_null() { Some(self.init()) - } else if ptr as usize == 1 { + } else if ptr == done() { None } else { Some((*ptr).clone()) - }; - self.lock.unlock(); - return ret + } } } @@ -53,10 +54,10 @@ impl Lazy { // the at exit handler). Otherwise we just return the freshly allocated // `Arc`. let registered = sys_common::at_exit(move || { - self.lock.lock(); - let ptr = self.ptr.get(); - self.ptr.set(1 as *mut _); - self.lock.unlock(); + let ptr = { + let _guard = self.lock.lock(); + self.ptr.replace(done()) + }; drop(Box::from_raw(ptr)) }); let ret = (self.init)(); diff --git a/src/libstd/sync/mutex.rs b/src/libstd/sync/mutex.rs index f3503b0b3a6..e5a410644b9 100644 --- a/src/libstd/sync/mutex.rs +++ b/src/libstd/sync/mutex.rs @@ -227,7 +227,7 @@ impl Mutex { #[stable(feature = "rust1", since = "1.0.0")] pub fn lock(&self) -> LockResult> { unsafe { - self.inner.lock(); + self.inner.raw_lock(); MutexGuard::new(self) } } @@ -454,7 +454,7 @@ impl<'a, T: ?Sized> Drop for MutexGuard<'a, T> { fn drop(&mut self) { unsafe { self.__lock.poison.done(&self.__poison); - self.__lock.inner.unlock(); + self.__lock.inner.raw_unlock(); } } } diff --git a/src/libstd/sys/redox/args.rs b/src/libstd/sys/redox/args.rs index 59ae2a74a6d..556ed77372e 100644 --- a/src/libstd/sys/redox/args.rs +++ b/src/libstd/sys/redox/args.rs @@ -73,17 +73,15 @@ mod imp { CStr::from_ptr(*argv.offset(i) as *const libc::c_char).to_bytes().to_vec() }).collect(); - LOCK.lock(); + let _guard = LOCK.lock(); let ptr = get_global_ptr(); assert!((*ptr).is_none()); (*ptr) = Some(box args); - LOCK.unlock(); } pub unsafe fn cleanup() { - LOCK.lock(); + let _guard = LOCK.lock(); *get_global_ptr() = None; - LOCK.unlock(); } pub fn args() -> Args { @@ -96,16 +94,14 @@ mod imp { fn clone() -> Option>> { unsafe { - LOCK.lock(); + let _guard = LOCK.lock(); let ptr = get_global_ptr(); - let ret = (*ptr).as_ref().map(|s| (**s).clone()); - LOCK.unlock(); - return ret + (*ptr).as_ref().map(|s| (**s).clone()) } } - fn get_global_ptr() -> *mut Option>>> { - unsafe { mem::transmute(&GLOBAL_ARGS_PTR) } + unsafe fn get_global_ptr() -> *mut Option>>> { + mem::transmute(&GLOBAL_ARGS_PTR) } } diff --git a/src/libstd/sys/unix/args.rs b/src/libstd/sys/unix/args.rs index e1c7ffc19e5..dc1dba6f2f9 100644 --- a/src/libstd/sys/unix/args.rs +++ b/src/libstd/sys/unix/args.rs @@ -82,17 +82,15 @@ mod imp { static LOCK: Mutex = Mutex::new(); pub unsafe fn init(argc: isize, argv: *const *const u8) { - LOCK.lock(); + let _guard = LOCK.lock(); ARGC = argc; ARGV = argv; - LOCK.unlock(); } pub unsafe fn cleanup() { - LOCK.lock(); + let _guard = LOCK.lock(); ARGC = 0; ARGV = ptr::null(); - LOCK.unlock(); } pub fn args() -> Args { @@ -104,13 +102,11 @@ mod imp { fn clone() -> Vec { unsafe { - LOCK.lock(); - let ret = (0..ARGC).map(|i| { + let _guard = LOCK.lock(); + (0..ARGC).map(|i| { let cstr = CStr::from_ptr(*ARGV.offset(i) as *const libc::c_char); OsStringExt::from_vec(cstr.to_bytes().to_vec()) - }).collect(); - LOCK.unlock(); - return ret + }).collect() } } } diff --git a/src/libstd/sys/unix/os.rs b/src/libstd/sys/unix/os.rs index 4c86fddee4b..82d05f78850 100644 --- a/src/libstd/sys/unix/os.rs +++ b/src/libstd/sys/unix/os.rs @@ -409,10 +409,9 @@ pub unsafe fn environ() -> *mut *const *const c_char { /// environment variables of the current process. pub fn env() -> Env { unsafe { - ENV_LOCK.lock(); + let _guard = ENV_LOCK.lock(); let mut environ = *environ(); if environ == ptr::null() { - ENV_LOCK.unlock(); panic!("os::env() failure getting env string from OS: {}", io::Error::last_os_error()); } @@ -423,12 +422,10 @@ pub fn env() -> Env { } environ = environ.offset(1); } - let ret = Env { + return Env { iter: result.into_iter(), _dont_send_or_sync_me: PhantomData, - }; - ENV_LOCK.unlock(); - return ret + } } fn parse(input: &[u8]) -> Option<(OsString, OsString)> { @@ -452,15 +449,14 @@ pub fn getenv(k: &OsStr) -> io::Result> { // always None as well let k = CString::new(k.as_bytes())?; unsafe { - ENV_LOCK.lock(); + let _guard = ENV_LOCK.lock(); let s = libc::getenv(k.as_ptr()) as *const libc::c_char; let ret = if s.is_null() { None } else { Some(OsStringExt::from_vec(CStr::from_ptr(s).to_bytes().to_vec())) }; - ENV_LOCK.unlock(); - return Ok(ret) + Ok(ret) } } @@ -469,10 +465,8 @@ pub fn setenv(k: &OsStr, v: &OsStr) -> io::Result<()> { let v = CString::new(v.as_bytes())?; unsafe { - ENV_LOCK.lock(); - let ret = cvt(libc::setenv(k.as_ptr(), v.as_ptr(), 1)).map(|_| ()); - ENV_LOCK.unlock(); - return ret + let _guard = ENV_LOCK.lock(); + cvt(libc::setenv(k.as_ptr(), v.as_ptr(), 1)).map(|_| ()) } } @@ -480,10 +474,8 @@ pub fn unsetenv(n: &OsStr) -> io::Result<()> { let nbuf = CString::new(n.as_bytes())?; unsafe { - ENV_LOCK.lock(); - let ret = cvt(libc::unsetenv(nbuf.as_ptr())).map(|_| ()); - ENV_LOCK.unlock(); - return ret + let _guard = ENV_LOCK.lock(); + cvt(libc::unsetenv(nbuf.as_ptr())).map(|_| ()) } } diff --git a/src/libstd/sys_common/at_exit_imp.rs b/src/libstd/sys_common/at_exit_imp.rs index 26da51c9825..d268d9ad6f9 100644 --- a/src/libstd/sys_common/at_exit_imp.rs +++ b/src/libstd/sys_common/at_exit_imp.rs @@ -14,6 +14,7 @@ use boxed::FnBox; use ptr; +use mem; use sys_common::mutex::Mutex; type Queue = Vec>; @@ -25,6 +26,8 @@ type Queue = Vec>; static LOCK: Mutex = Mutex::new(); static mut QUEUE: *mut Queue = ptr::null_mut(); +const DONE: *mut Queue = 1_usize as *mut _; + // The maximum number of times the cleanup routines will be run. While running // the at_exit closures new ones may be registered, and this count is the number // of times the new closures will be allowed to register successfully. After @@ -35,7 +38,7 @@ unsafe fn init() -> bool { if QUEUE.is_null() { let state: Box = box Vec::new(); QUEUE = Box::into_raw(state); - } else if QUEUE as usize == 1 { + } else if QUEUE == DONE { // can't re-init after a cleanup return false } @@ -44,18 +47,18 @@ unsafe fn init() -> bool { } pub fn cleanup() { - for i in 0..ITERS { + for i in 1..=ITERS { unsafe { - LOCK.lock(); - let queue = QUEUE; - QUEUE = if i == ITERS - 1 {1} else {0} as *mut _; - LOCK.unlock(); + let queue = { + let _guard = LOCK.lock(); + mem::replace(&mut QUEUE, if i == ITERS { DONE } else { ptr::null_mut() }) + }; // make sure we're not recursively cleaning up - assert!(queue as usize != 1); + assert!(queue != DONE); // If we never called init, not need to cleanup! - if queue as usize != 0 { + if !queue.is_null() { let queue: Box = Box::from_raw(queue); for to_run in *queue { to_run(); @@ -66,15 +69,13 @@ pub fn cleanup() { } pub fn push(f: Box) -> bool { - let mut ret = true; unsafe { - LOCK.lock(); + let _guard = LOCK.lock(); if init() { (*QUEUE).push(f); + true } else { - ret = false; + false } - LOCK.unlock(); } - ret } diff --git a/src/libstd/sys_common/mutex.rs b/src/libstd/sys_common/mutex.rs index d1a738770d3..608355b7d70 100644 --- a/src/libstd/sys_common/mutex.rs +++ b/src/libstd/sys_common/mutex.rs @@ -37,7 +37,15 @@ impl Mutex { /// Behavior is undefined if the mutex has been moved between this and any /// previous function call. #[inline] - pub unsafe fn lock(&self) { self.0.lock() } + pub unsafe fn raw_lock(&self) { self.0.lock() } + + /// Calls raw_lock() and then returns an RAII guard to guarantee the mutex + /// will be unlocked. + #[inline] + pub unsafe fn lock(&self) -> MutexGuard { + self.raw_lock(); + MutexGuard(&self.0) + } /// Attempts to lock the mutex without blocking, returning whether it was /// successfully acquired or not. @@ -51,8 +59,11 @@ impl Mutex { /// /// Behavior is undefined if the current thread does not actually hold the /// mutex. + /// + /// Consider switching from the pair of raw_lock() and raw_unlock() to + /// lock() whenever possible. #[inline] - pub unsafe fn unlock(&self) { self.0.unlock() } + pub unsafe fn raw_unlock(&self) { self.0.unlock() } /// Deallocates all resources associated with this mutex. /// @@ -64,3 +75,14 @@ impl Mutex { // not meant to be exported to the outside world, just the containing module pub fn raw(mutex: &Mutex) -> &imp::Mutex { &mutex.0 } + +#[must_use] +/// A simple RAII utility for the above Mutex without the poisoning semantics. +pub struct MutexGuard<'a>(&'a imp::Mutex); + +impl<'a> Drop for MutexGuard<'a> { + #[inline] + fn drop(&mut self) { + unsafe { self.0.unlock(); } + } +} diff --git a/src/libstd/sys_common/thread_local.rs b/src/libstd/sys_common/thread_local.rs index d0d6224de0a..75f6b9ac7fd 100644 --- a/src/libstd/sys_common/thread_local.rs +++ b/src/libstd/sys_common/thread_local.rs @@ -162,13 +162,12 @@ impl StaticKey { // we just simplify the whole branch. if imp::requires_synchronized_create() { static INIT_LOCK: Mutex = Mutex::new(); - INIT_LOCK.lock(); + let _guard = INIT_LOCK.lock(); let mut key = self.key.load(Ordering::SeqCst); if key == 0 { key = imp::create(self.dtor) as usize; self.key.store(key, Ordering::SeqCst); } - INIT_LOCK.unlock(); rtassert!(key != 0); return key } diff --git a/src/libstd/thread/mod.rs b/src/libstd/thread/mod.rs index 1b976b79b4c..1dacf99b64b 100644 --- a/src/libstd/thread/mod.rs +++ b/src/libstd/thread/mod.rs @@ -935,20 +935,17 @@ impl ThreadId { static mut COUNTER: u64 = 0; unsafe { - GUARD.lock(); + let _guard = GUARD.lock(); // If we somehow use up all our bits, panic so that we're not // covering up subtle bugs of IDs being reused. if COUNTER == ::u64::MAX { - GUARD.unlock(); panic!("failed to generate unique thread ID: bitspace exhausted"); } let id = COUNTER; COUNTER += 1; - GUARD.unlock(); - ThreadId(id) } } -- cgit 1.4.1-3-g733a5 From c7638edf5293dd471d951e64671d60febd0b628c Mon Sep 17 00:00:00 2001 From: Simon Sapin Date: Fri, 15 Jun 2018 04:07:09 +0200 Subject: Rename alloc::arc to alloc::sync, to match std::sync --- src/liballoc/arc.rs | 1936 ------------------------------------------------ src/liballoc/lib.rs | 4 +- src/liballoc/sync.rs | 1936 ++++++++++++++++++++++++++++++++++++++++++++++++ src/liballoc/task.rs | 2 +- src/libstd/sync/mod.rs | 2 +- 5 files changed, 1940 insertions(+), 1940 deletions(-) delete mode 100644 src/liballoc/arc.rs create mode 100644 src/liballoc/sync.rs (limited to 'src/libstd/sync') diff --git a/src/liballoc/arc.rs b/src/liballoc/arc.rs deleted file mode 100644 index 2abd9c85c57..00000000000 --- a/src/liballoc/arc.rs +++ /dev/null @@ -1,1936 +0,0 @@ -// Copyright 2012-2014 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. - -#![stable(feature = "rust1", since = "1.0.0")] - -//! Thread-safe reference-counting pointers. -//! -//! See the [`Arc`][arc] documentation for more details. -//! -//! [arc]: struct.Arc.html - -use core::any::Any; -use core::sync::atomic; -use core::sync::atomic::Ordering::{Acquire, Relaxed, Release, SeqCst}; -use core::borrow; -use core::fmt; -use core::cmp::Ordering; -use core::intrinsics::abort; -use core::mem::{self, align_of_val, size_of_val}; -use core::ops::Deref; -use core::ops::CoerceUnsized; -use core::ptr::{self, NonNull}; -use core::marker::{Unsize, PhantomData}; -use core::hash::{Hash, Hasher}; -use core::{isize, usize}; -use core::convert::From; - -use alloc::{Global, Alloc, Layout, box_free, handle_alloc_error}; -use boxed::Box; -use string::String; -use vec::Vec; - -/// A soft limit on the amount of references that may be made to an `Arc`. -/// -/// Going above this limit will abort your program (although not -/// necessarily) at _exactly_ `MAX_REFCOUNT + 1` references. -const MAX_REFCOUNT: usize = (isize::MAX) as usize; - -/// A sentinel value that is used for the pointer of `Weak::new()`. -const WEAK_EMPTY: usize = 1; - -/// A thread-safe reference-counting pointer. 'Arc' stands for 'Atomically -/// Reference Counted'. -/// -/// The type `Arc` provides shared ownership of a value of type `T`, -/// allocated in the heap. Invoking [`clone`][clone] on `Arc` produces -/// a new pointer to the same value in the heap. When the last `Arc` -/// pointer to a given value is destroyed, the pointed-to value is -/// also destroyed. -/// -/// Shared references in Rust disallow mutation by default, and `Arc` is no -/// exception: you cannot generally obtain a mutable reference to something -/// inside an `Arc`. If you need to mutate through an `Arc`, use -/// [`Mutex`][mutex], [`RwLock`][rwlock], or one of the [`Atomic`][atomic] -/// types. -/// -/// ## Thread Safety -/// -/// Unlike [`Rc`], `Arc` uses atomic operations for its reference -/// counting. This means that it is thread-safe. The disadvantage is that -/// atomic operations are more expensive than ordinary memory accesses. If you -/// are not sharing reference-counted values between threads, consider using -/// [`Rc`] for lower overhead. [`Rc`] is a safe default, because the -/// compiler will catch any attempt to send an [`Rc`] between threads. -/// However, a library might choose `Arc` in order to give library consumers -/// more flexibility. -/// -/// `Arc` will implement [`Send`] and [`Sync`] as long as the `T` implements -/// [`Send`] and [`Sync`]. Why can't you put a non-thread-safe type `T` in an -/// `Arc` to make it thread-safe? This may be a bit counter-intuitive at -/// first: after all, isn't the point of `Arc` thread safety? The key is -/// this: `Arc` makes it thread safe to have multiple ownership of the same -/// data, but it doesn't add thread safety to its data. Consider -/// `Arc<`[`RefCell`]`>`. [`RefCell`] isn't [`Sync`], and if `Arc` was always -/// [`Send`], `Arc<`[`RefCell`]`>` would be as well. But then we'd have a problem: -/// [`RefCell`] is not thread safe; it keeps track of the borrowing count using -/// non-atomic operations. -/// -/// In the end, this means that you may need to pair `Arc` with some sort of -/// [`std::sync`] type, usually [`Mutex`][mutex]. -/// -/// ## Breaking cycles with `Weak` -/// -/// The [`downgrade`][downgrade] method can be used to create a non-owning -/// [`Weak`][weak] pointer. A [`Weak`][weak] pointer can be [`upgrade`][upgrade]d -/// to an `Arc`, but this will return [`None`] if the value has already been -/// dropped. -/// -/// A cycle between `Arc` pointers will never be deallocated. For this reason, -/// [`Weak`][weak] is used to break cycles. For example, a tree could have -/// strong `Arc` pointers from parent nodes to children, and [`Weak`][weak] -/// pointers from children back to their parents. -/// -/// # Cloning references -/// -/// Creating a new reference from an existing reference counted pointer is done using the -/// `Clone` trait implemented for [`Arc`][arc] and [`Weak`][weak]. -/// -/// ``` -/// use std::sync::Arc; -/// let foo = Arc::new(vec![1.0, 2.0, 3.0]); -/// // The two syntaxes below are equivalent. -/// let a = foo.clone(); -/// let b = Arc::clone(&foo); -/// // a and b both point to the same memory location as foo. -/// ``` -/// -/// The [`Arc::clone(&from)`] syntax is the most idiomatic because it conveys more explicitly -/// the meaning of the code. In the example above, this syntax makes it easier to see that -/// this code is creating a new reference rather than copying the whole content of foo. -/// -/// ## `Deref` behavior -/// -/// `Arc` automatically dereferences to `T` (via the [`Deref`][deref] trait), -/// so you can call `T`'s methods on a value of type `Arc`. To avoid name -/// clashes with `T`'s methods, the methods of `Arc` itself are [associated -/// functions][assoc], called using function-like syntax: -/// -/// ``` -/// use std::sync::Arc; -/// let my_arc = Arc::new(()); -/// -/// Arc::downgrade(&my_arc); -/// ``` -/// -/// [`Weak`][weak] does not auto-dereference to `T`, because the value may have -/// already been destroyed. -/// -/// [arc]: struct.Arc.html -/// [weak]: struct.Weak.html -/// [`Rc`]: ../../std/rc/struct.Rc.html -/// [clone]: ../../std/clone/trait.Clone.html#tymethod.clone -/// [mutex]: ../../std/sync/struct.Mutex.html -/// [rwlock]: ../../std/sync/struct.RwLock.html -/// [atomic]: ../../std/sync/atomic/index.html -/// [`Send`]: ../../std/marker/trait.Send.html -/// [`Sync`]: ../../std/marker/trait.Sync.html -/// [deref]: ../../std/ops/trait.Deref.html -/// [downgrade]: struct.Arc.html#method.downgrade -/// [upgrade]: struct.Weak.html#method.upgrade -/// [`None`]: ../../std/option/enum.Option.html#variant.None -/// [assoc]: ../../book/first-edition/method-syntax.html#associated-functions -/// [`RefCell`]: ../../std/cell/struct.RefCell.html -/// [`std::sync`]: ../../std/sync/index.html -/// [`Arc::clone(&from)`]: #method.clone -/// -/// # Examples -/// -/// Sharing some immutable data between threads: -/// -// Note that we **do not** run these tests here. The windows builders get super -// unhappy if a thread outlives the main thread and then exits at the same time -// (something deadlocks) so we just avoid this entirely by not running these -// tests. -/// ```no_run -/// use std::sync::Arc; -/// use std::thread; -/// -/// let five = Arc::new(5); -/// -/// for _ in 0..10 { -/// let five = Arc::clone(&five); -/// -/// thread::spawn(move || { -/// println!("{:?}", five); -/// }); -/// } -/// ``` -/// -/// Sharing a mutable [`AtomicUsize`]: -/// -/// [`AtomicUsize`]: ../../std/sync/atomic/struct.AtomicUsize.html -/// -/// ```no_run -/// use std::sync::Arc; -/// use std::sync::atomic::{AtomicUsize, Ordering}; -/// use std::thread; -/// -/// let val = Arc::new(AtomicUsize::new(5)); -/// -/// for _ in 0..10 { -/// let val = Arc::clone(&val); -/// -/// thread::spawn(move || { -/// let v = val.fetch_add(1, Ordering::SeqCst); -/// println!("{:?}", v); -/// }); -/// } -/// ``` -/// -/// See the [`rc` documentation][rc_examples] for more examples of reference -/// counting in general. -/// -/// [rc_examples]: ../../std/rc/index.html#examples -#[stable(feature = "rust1", since = "1.0.0")] -pub struct Arc { - ptr: NonNull>, - phantom: PhantomData, -} - -#[stable(feature = "rust1", since = "1.0.0")] -unsafe impl Send for Arc {} -#[stable(feature = "rust1", since = "1.0.0")] -unsafe impl Sync for Arc {} - -#[unstable(feature = "coerce_unsized", issue = "27732")] -impl, U: ?Sized> CoerceUnsized> for Arc {} - -/// `Weak` is a version of [`Arc`] that holds a non-owning reference to the -/// managed value. The value is accessed by calling [`upgrade`] on the `Weak` -/// pointer, which returns an [`Option`]`<`[`Arc`]`>`. -/// -/// Since a `Weak` reference does not count towards ownership, it will not -/// prevent the inner value from being dropped, and `Weak` itself makes no -/// guarantees about the value still being present and may return [`None`] -/// when [`upgrade`]d. -/// -/// A `Weak` pointer is useful for keeping a temporary reference to the value -/// within [`Arc`] without extending its lifetime. It is also used to prevent -/// circular references between [`Arc`] pointers, since mutual owning references -/// would never allow either [`Arc`] to be dropped. For example, a tree could -/// have strong [`Arc`] pointers from parent nodes to children, and `Weak` -/// pointers from children back to their parents. -/// -/// The typical way to obtain a `Weak` pointer is to call [`Arc::downgrade`]. -/// -/// [`Arc`]: struct.Arc.html -/// [`Arc::downgrade`]: struct.Arc.html#method.downgrade -/// [`upgrade`]: struct.Weak.html#method.upgrade -/// [`Option`]: ../../std/option/enum.Option.html -/// [`None`]: ../../std/option/enum.Option.html#variant.None -#[stable(feature = "arc_weak", since = "1.4.0")] -pub struct Weak { - // This is a `NonNull` to allow optimizing the size of this type in enums, - // but it is actually not truly "non-null". A `Weak::new()` will set this - // to a sentinel value, instead of needing to allocate some space in the - // heap. - ptr: NonNull>, -} - -#[stable(feature = "arc_weak", since = "1.4.0")] -unsafe impl Send for Weak {} -#[stable(feature = "arc_weak", since = "1.4.0")] -unsafe impl Sync for Weak {} - -#[unstable(feature = "coerce_unsized", issue = "27732")] -impl, U: ?Sized> CoerceUnsized> for Weak {} - -#[stable(feature = "arc_weak", since = "1.4.0")] -impl fmt::Debug for Weak { - fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { - write!(f, "(Weak)") - } -} - -struct ArcInner { - strong: atomic::AtomicUsize, - - // the value usize::MAX acts as a sentinel for temporarily "locking" the - // ability to upgrade weak pointers or downgrade strong ones; this is used - // to avoid races in `make_mut` and `get_mut`. - weak: atomic::AtomicUsize, - - data: T, -} - -unsafe impl Send for ArcInner {} -unsafe impl Sync for ArcInner {} - -impl Arc { - /// Constructs a new `Arc`. - /// - /// # Examples - /// - /// ``` - /// use std::sync::Arc; - /// - /// let five = Arc::new(5); - /// ``` - #[inline] - #[stable(feature = "rust1", since = "1.0.0")] - pub fn new(data: T) -> Arc { - // Start the weak pointer count as 1 which is the weak pointer that's - // held by all the strong pointers (kinda), see std/rc.rs for more info - let x: Box<_> = box ArcInner { - strong: atomic::AtomicUsize::new(1), - weak: atomic::AtomicUsize::new(1), - data, - }; - Arc { ptr: Box::into_raw_non_null(x), phantom: PhantomData } - } - - /// Returns the contained value, if the `Arc` has exactly one strong reference. - /// - /// Otherwise, an [`Err`][result] is returned with the same `Arc` that was - /// passed in. - /// - /// This will succeed even if there are outstanding weak references. - /// - /// [result]: ../../std/result/enum.Result.html - /// - /// # Examples - /// - /// ``` - /// use std::sync::Arc; - /// - /// let x = Arc::new(3); - /// assert_eq!(Arc::try_unwrap(x), Ok(3)); - /// - /// let x = Arc::new(4); - /// let _y = Arc::clone(&x); - /// assert_eq!(*Arc::try_unwrap(x).unwrap_err(), 4); - /// ``` - #[inline] - #[stable(feature = "arc_unique", since = "1.4.0")] - pub fn try_unwrap(this: Self) -> Result { - // See `drop` for why all these atomics are like this - if this.inner().strong.compare_exchange(1, 0, Release, Relaxed).is_err() { - return Err(this); - } - - atomic::fence(Acquire); - - unsafe { - let elem = ptr::read(&this.ptr.as_ref().data); - - // Make a weak pointer to clean up the implicit strong-weak reference - let _weak = Weak { ptr: this.ptr }; - mem::forget(this); - - Ok(elem) - } - } -} - -impl Arc { - /// Consumes the `Arc`, returning the wrapped pointer. - /// - /// To avoid a memory leak the pointer must be converted back to an `Arc` using - /// [`Arc::from_raw`][from_raw]. - /// - /// [from_raw]: struct.Arc.html#method.from_raw - /// - /// # Examples - /// - /// ``` - /// use std::sync::Arc; - /// - /// let x = Arc::new(10); - /// let x_ptr = Arc::into_raw(x); - /// assert_eq!(unsafe { *x_ptr }, 10); - /// ``` - #[stable(feature = "rc_raw", since = "1.17.0")] - pub fn into_raw(this: Self) -> *const T { - let ptr: *const T = &*this; - mem::forget(this); - ptr - } - - /// Constructs an `Arc` from a raw pointer. - /// - /// The raw pointer must have been previously returned by a call to a - /// [`Arc::into_raw`][into_raw]. - /// - /// This function is unsafe because improper use may lead to memory problems. For example, a - /// double-free may occur if the function is called twice on the same raw pointer. - /// - /// [into_raw]: struct.Arc.html#method.into_raw - /// - /// # Examples - /// - /// ``` - /// use std::sync::Arc; - /// - /// let x = Arc::new(10); - /// let x_ptr = Arc::into_raw(x); - /// - /// unsafe { - /// // Convert back to an `Arc` to prevent leak. - /// let x = Arc::from_raw(x_ptr); - /// assert_eq!(*x, 10); - /// - /// // Further calls to `Arc::from_raw(x_ptr)` would be memory unsafe. - /// } - /// - /// // The memory was freed when `x` went out of scope above, so `x_ptr` is now dangling! - /// ``` - #[stable(feature = "rc_raw", since = "1.17.0")] - pub unsafe fn from_raw(ptr: *const T) -> Self { - // Align the unsized value to the end of the ArcInner. - // Because it is ?Sized, it will always be the last field in memory. - let align = align_of_val(&*ptr); - let layout = Layout::new::>(); - let offset = (layout.size() + layout.padding_needed_for(align)) as isize; - - // Reverse the offset to find the original ArcInner. - let fake_ptr = ptr as *mut ArcInner; - let arc_ptr = set_data_ptr(fake_ptr, (ptr as *mut u8).offset(-offset)); - - Arc { - ptr: NonNull::new_unchecked(arc_ptr), - phantom: PhantomData, - } - } - - /// Creates a new [`Weak`][weak] pointer to this value. - /// - /// [weak]: struct.Weak.html - /// - /// # Examples - /// - /// ``` - /// use std::sync::Arc; - /// - /// let five = Arc::new(5); - /// - /// let weak_five = Arc::downgrade(&five); - /// ``` - #[stable(feature = "arc_weak", since = "1.4.0")] - pub fn downgrade(this: &Self) -> Weak { - // This Relaxed is OK because we're checking the value in the CAS - // below. - let mut cur = this.inner().weak.load(Relaxed); - - loop { - // check if the weak counter is currently "locked"; if so, spin. - if cur == usize::MAX { - cur = this.inner().weak.load(Relaxed); - continue; - } - - // NOTE: this code currently ignores the possibility of overflow - // into usize::MAX; in general both Rc and Arc need to be adjusted - // to deal with overflow. - - // Unlike with Clone(), we need this to be an Acquire read to - // synchronize with the write coming from `is_unique`, so that the - // events prior to that write happen before this read. - match this.inner().weak.compare_exchange_weak(cur, cur + 1, Acquire, Relaxed) { - Ok(_) => return Weak { ptr: this.ptr }, - Err(old) => cur = old, - } - } - } - - /// Gets the number of [`Weak`][weak] pointers to this value. - /// - /// [weak]: struct.Weak.html - /// - /// # Safety - /// - /// This method by itself is safe, but using it correctly requires extra care. - /// Another thread can change the weak count at any time, - /// including potentially between calling this method and acting on the result. - /// - /// # Examples - /// - /// ``` - /// use std::sync::Arc; - /// - /// let five = Arc::new(5); - /// let _weak_five = Arc::downgrade(&five); - /// - /// // This assertion is deterministic because we haven't shared - /// // the `Arc` or `Weak` between threads. - /// assert_eq!(1, Arc::weak_count(&five)); - /// ``` - #[inline] - #[stable(feature = "arc_counts", since = "1.15.0")] - pub fn weak_count(this: &Self) -> usize { - let cnt = this.inner().weak.load(SeqCst); - // If the weak count is currently locked, the value of the - // count was 0 just before taking the lock. - if cnt == usize::MAX { 0 } else { cnt - 1 } - } - - /// Gets the number of strong (`Arc`) pointers to this value. - /// - /// # Safety - /// - /// This method by itself is safe, but using it correctly requires extra care. - /// Another thread can change the strong count at any time, - /// including potentially between calling this method and acting on the result. - /// - /// # Examples - /// - /// ``` - /// use std::sync::Arc; - /// - /// let five = Arc::new(5); - /// let _also_five = Arc::clone(&five); - /// - /// // This assertion is deterministic because we haven't shared - /// // the `Arc` between threads. - /// assert_eq!(2, Arc::strong_count(&five)); - /// ``` - #[inline] - #[stable(feature = "arc_counts", since = "1.15.0")] - pub fn strong_count(this: &Self) -> usize { - this.inner().strong.load(SeqCst) - } - - #[inline] - fn inner(&self) -> &ArcInner { - // This unsafety is ok because while this arc is alive we're guaranteed - // that the inner pointer is valid. Furthermore, we know that the - // `ArcInner` structure itself is `Sync` because the inner data is - // `Sync` as well, so we're ok loaning out an immutable pointer to these - // contents. - unsafe { self.ptr.as_ref() } - } - - // Non-inlined part of `drop`. - #[inline(never)] - unsafe fn drop_slow(&mut self) { - // Destroy the data at this time, even though we may not free the box - // allocation itself (there may still be weak pointers lying around). - ptr::drop_in_place(&mut self.ptr.as_mut().data); - - if self.inner().weak.fetch_sub(1, Release) == 1 { - atomic::fence(Acquire); - Global.dealloc(self.ptr.cast(), Layout::for_value(self.ptr.as_ref())) - } - } - - #[inline] - #[stable(feature = "ptr_eq", since = "1.17.0")] - /// Returns true if the two `Arc`s point to the same value (not - /// just values that compare as equal). - /// - /// # Examples - /// - /// ``` - /// use std::sync::Arc; - /// - /// let five = Arc::new(5); - /// let same_five = Arc::clone(&five); - /// let other_five = Arc::new(5); - /// - /// assert!(Arc::ptr_eq(&five, &same_five)); - /// assert!(!Arc::ptr_eq(&five, &other_five)); - /// ``` - pub fn ptr_eq(this: &Self, other: &Self) -> bool { - this.ptr.as_ptr() == other.ptr.as_ptr() - } -} - -impl Arc { - // Allocates an `ArcInner` with sufficient space for an unsized value - unsafe fn allocate_for_ptr(ptr: *const T) -> *mut ArcInner { - // Create a fake ArcInner to find allocation size and alignment - let fake_ptr = ptr as *mut ArcInner; - - let layout = Layout::for_value(&*fake_ptr); - - let mem = Global.alloc(layout) - .unwrap_or_else(|_| handle_alloc_error(layout)); - - // Initialize the real ArcInner - let inner = set_data_ptr(ptr as *mut T, mem.as_ptr() as *mut u8) as *mut ArcInner; - - ptr::write(&mut (*inner).strong, atomic::AtomicUsize::new(1)); - ptr::write(&mut (*inner).weak, atomic::AtomicUsize::new(1)); - - inner - } - - fn from_box(v: Box) -> Arc { - unsafe { - let box_unique = Box::into_unique(v); - let bptr = box_unique.as_ptr(); - - let value_size = size_of_val(&*bptr); - let ptr = Self::allocate_for_ptr(bptr); - - // Copy value as bytes - ptr::copy_nonoverlapping( - bptr as *const T as *const u8, - &mut (*ptr).data as *mut _ as *mut u8, - value_size); - - // Free the allocation without dropping its contents - box_free(box_unique); - - Arc { ptr: NonNull::new_unchecked(ptr), phantom: PhantomData } - } - } -} - -// Sets the data pointer of a `?Sized` raw pointer. -// -// For a slice/trait object, this sets the `data` field and leaves the rest -// unchanged. For a sized raw pointer, this simply sets the pointer. -unsafe fn set_data_ptr(mut ptr: *mut T, data: *mut U) -> *mut T { - ptr::write(&mut ptr as *mut _ as *mut *mut u8, data as *mut u8); - ptr -} - -impl Arc<[T]> { - // Copy elements from slice into newly allocated Arc<[T]> - // - // Unsafe because the caller must either take ownership or bind `T: Copy` - unsafe fn copy_from_slice(v: &[T]) -> Arc<[T]> { - let v_ptr = v as *const [T]; - let ptr = Self::allocate_for_ptr(v_ptr); - - ptr::copy_nonoverlapping( - v.as_ptr(), - &mut (*ptr).data as *mut [T] as *mut T, - v.len()); - - Arc { ptr: NonNull::new_unchecked(ptr), phantom: PhantomData } - } -} - -// Specialization trait used for From<&[T]> -trait ArcFromSlice { - fn from_slice(slice: &[T]) -> Self; -} - -impl ArcFromSlice for Arc<[T]> { - #[inline] - default fn from_slice(v: &[T]) -> Self { - // Panic guard while cloning T elements. - // In the event of a panic, elements that have been written - // into the new ArcInner will be dropped, then the memory freed. - struct Guard { - mem: NonNull, - elems: *mut T, - layout: Layout, - n_elems: usize, - } - - impl Drop for Guard { - fn drop(&mut self) { - use core::slice::from_raw_parts_mut; - - unsafe { - let slice = from_raw_parts_mut(self.elems, self.n_elems); - ptr::drop_in_place(slice); - - Global.dealloc(self.mem.cast(), self.layout.clone()); - } - } - } - - unsafe { - let v_ptr = v as *const [T]; - let ptr = Self::allocate_for_ptr(v_ptr); - - let mem = ptr as *mut _ as *mut u8; - let layout = Layout::for_value(&*ptr); - - // Pointer to first element - let elems = &mut (*ptr).data as *mut [T] as *mut T; - - let mut guard = Guard{ - mem: NonNull::new_unchecked(mem), - elems: elems, - layout: layout, - n_elems: 0, - }; - - for (i, item) in v.iter().enumerate() { - ptr::write(elems.offset(i as isize), item.clone()); - guard.n_elems += 1; - } - - // All clear. Forget the guard so it doesn't free the new ArcInner. - mem::forget(guard); - - Arc { ptr: NonNull::new_unchecked(ptr), phantom: PhantomData } - } - } -} - -impl ArcFromSlice for Arc<[T]> { - #[inline] - fn from_slice(v: &[T]) -> Self { - unsafe { Arc::copy_from_slice(v) } - } -} - -#[stable(feature = "rust1", since = "1.0.0")] -impl Clone for Arc { - /// Makes a clone of the `Arc` pointer. - /// - /// This creates another pointer to the same inner value, increasing the - /// strong reference count. - /// - /// # Examples - /// - /// ``` - /// use std::sync::Arc; - /// - /// let five = Arc::new(5); - /// - /// Arc::clone(&five); - /// ``` - #[inline] - fn clone(&self) -> Arc { - // Using a relaxed ordering is alright here, as knowledge of the - // original reference prevents other threads from erroneously deleting - // the object. - // - // As explained in the [Boost documentation][1], Increasing the - // reference counter can always be done with memory_order_relaxed: New - // references to an object can only be formed from an existing - // reference, and passing an existing reference from one thread to - // another must already provide any required synchronization. - // - // [1]: (www.boost.org/doc/libs/1_55_0/doc/html/atomic/usage_examples.html) - let old_size = self.inner().strong.fetch_add(1, Relaxed); - - // However we need to guard against massive refcounts in case someone - // is `mem::forget`ing Arcs. If we don't do this the count can overflow - // and users will use-after free. We racily saturate to `isize::MAX` on - // the assumption that there aren't ~2 billion threads incrementing - // the reference count at once. This branch will never be taken in - // any realistic program. - // - // We abort because such a program is incredibly degenerate, and we - // don't care to support it. - if old_size > MAX_REFCOUNT { - unsafe { - abort(); - } - } - - Arc { ptr: self.ptr, phantom: PhantomData } - } -} - -#[stable(feature = "rust1", since = "1.0.0")] -impl Deref for Arc { - type Target = T; - - #[inline] - fn deref(&self) -> &T { - &self.inner().data - } -} - -impl Arc { - /// Makes a mutable reference into the given `Arc`. - /// - /// If there are other `Arc` or [`Weak`][weak] pointers to the same value, - /// then `make_mut` will invoke [`clone`][clone] on the inner value to - /// ensure unique ownership. This is also referred to as clone-on-write. - /// - /// See also [`get_mut`][get_mut], which will fail rather than cloning. - /// - /// [weak]: struct.Weak.html - /// [clone]: ../../std/clone/trait.Clone.html#tymethod.clone - /// [get_mut]: struct.Arc.html#method.get_mut - /// - /// # Examples - /// - /// ``` - /// use std::sync::Arc; - /// - /// let mut data = Arc::new(5); - /// - /// *Arc::make_mut(&mut data) += 1; // Won't clone anything - /// let mut other_data = Arc::clone(&data); // Won't clone inner data - /// *Arc::make_mut(&mut data) += 1; // Clones inner data - /// *Arc::make_mut(&mut data) += 1; // Won't clone anything - /// *Arc::make_mut(&mut other_data) *= 2; // Won't clone anything - /// - /// // Now `data` and `other_data` point to different values. - /// assert_eq!(*data, 8); - /// assert_eq!(*other_data, 12); - /// ``` - #[inline] - #[stable(feature = "arc_unique", since = "1.4.0")] - pub fn make_mut(this: &mut Self) -> &mut T { - // Note that we hold both a strong reference and a weak reference. - // Thus, releasing our strong reference only will not, by itself, cause - // the memory to be deallocated. - // - // Use Acquire to ensure that we see any writes to `weak` that happen - // before release writes (i.e., decrements) to `strong`. Since we hold a - // weak count, there's no chance the ArcInner itself could be - // deallocated. - if this.inner().strong.compare_exchange(1, 0, Acquire, Relaxed).is_err() { - // Another strong pointer exists; clone - *this = Arc::new((**this).clone()); - } else if this.inner().weak.load(Relaxed) != 1 { - // Relaxed suffices in the above because this is fundamentally an - // optimization: we are always racing with weak pointers being - // dropped. Worst case, we end up allocated a new Arc unnecessarily. - - // We removed the last strong ref, but there are additional weak - // refs remaining. We'll move the contents to a new Arc, and - // invalidate the other weak refs. - - // Note that it is not possible for the read of `weak` to yield - // usize::MAX (i.e., locked), since the weak count can only be - // locked by a thread with a strong reference. - - // Materialize our own implicit weak pointer, so that it can clean - // up the ArcInner as needed. - let weak = Weak { ptr: this.ptr }; - - // mark the data itself as already deallocated - unsafe { - // there is no data race in the implicit write caused by `read` - // here (due to zeroing) because data is no longer accessed by - // other threads (due to there being no more strong refs at this - // point). - let mut swap = Arc::new(ptr::read(&weak.ptr.as_ref().data)); - mem::swap(this, &mut swap); - mem::forget(swap); - } - } else { - // We were the sole reference of either kind; bump back up the - // strong ref count. - this.inner().strong.store(1, Release); - } - - // As with `get_mut()`, the unsafety is ok because our reference was - // either unique to begin with, or became one upon cloning the contents. - unsafe { - &mut this.ptr.as_mut().data - } - } -} - -impl Arc { - /// Returns a mutable reference to the inner value, if there are - /// no other `Arc` or [`Weak`][weak] pointers to the same value. - /// - /// Returns [`None`][option] otherwise, because it is not safe to - /// mutate a shared value. - /// - /// See also [`make_mut`][make_mut], which will [`clone`][clone] - /// the inner value when it's shared. - /// - /// [weak]: struct.Weak.html - /// [option]: ../../std/option/enum.Option.html - /// [make_mut]: struct.Arc.html#method.make_mut - /// [clone]: ../../std/clone/trait.Clone.html#tymethod.clone - /// - /// # Examples - /// - /// ``` - /// use std::sync::Arc; - /// - /// let mut x = Arc::new(3); - /// *Arc::get_mut(&mut x).unwrap() = 4; - /// assert_eq!(*x, 4); - /// - /// let _y = Arc::clone(&x); - /// assert!(Arc::get_mut(&mut x).is_none()); - /// ``` - #[inline] - #[stable(feature = "arc_unique", since = "1.4.0")] - pub fn get_mut(this: &mut Self) -> Option<&mut T> { - if this.is_unique() { - // This unsafety is ok because we're guaranteed that the pointer - // returned is the *only* pointer that will ever be returned to T. Our - // reference count is guaranteed to be 1 at this point, and we required - // the Arc itself to be `mut`, so we're returning the only possible - // reference to the inner data. - unsafe { - Some(&mut this.ptr.as_mut().data) - } - } else { - None - } - } - - /// Determine whether this is the unique reference (including weak refs) to - /// the underlying data. - /// - /// Note that this requires locking the weak ref count. - fn is_unique(&mut self) -> bool { - // lock the weak pointer count if we appear to be the sole weak pointer - // holder. - // - // The acquire label here ensures a happens-before relationship with any - // writes to `strong` prior to decrements of the `weak` count (via drop, - // which uses Release). - if self.inner().weak.compare_exchange(1, usize::MAX, Acquire, Relaxed).is_ok() { - // Due to the previous acquire read, this will observe any writes to - // `strong` that were due to upgrading weak pointers; only strong - // clones remain, which require that the strong count is > 1 anyway. - let unique = self.inner().strong.load(Relaxed) == 1; - - // The release write here synchronizes with a read in `downgrade`, - // effectively preventing the above read of `strong` from happening - // after the write. - self.inner().weak.store(1, Release); // release the lock - unique - } else { - false - } - } -} - -#[stable(feature = "rust1", since = "1.0.0")] -unsafe impl<#[may_dangle] T: ?Sized> Drop for Arc { - /// Drops the `Arc`. - /// - /// This will decrement the strong reference count. If the strong reference - /// count reaches zero then the only other references (if any) are - /// [`Weak`][weak], so we `drop` the inner value. - /// - /// [weak]: struct.Weak.html - /// - /// # Examples - /// - /// ``` - /// use std::sync::Arc; - /// - /// struct Foo; - /// - /// impl Drop for Foo { - /// fn drop(&mut self) { - /// println!("dropped!"); - /// } - /// } - /// - /// let foo = Arc::new(Foo); - /// let foo2 = Arc::clone(&foo); - /// - /// drop(foo); // Doesn't print anything - /// drop(foo2); // Prints "dropped!" - /// ``` - #[inline] - fn drop(&mut self) { - // Because `fetch_sub` is already atomic, we do not need to synchronize - // with other threads unless we are going to delete the object. This - // same logic applies to the below `fetch_sub` to the `weak` count. - if self.inner().strong.fetch_sub(1, Release) != 1 { - return; - } - - // This fence is needed to prevent reordering of use of the data and - // deletion of the data. Because it is marked `Release`, the decreasing - // of the reference count synchronizes with this `Acquire` fence. This - // means that use of the data happens before decreasing the reference - // count, which happens before this fence, which happens before the - // deletion of the data. - // - // As explained in the [Boost documentation][1], - // - // > It is important to enforce any possible access to the object in one - // > thread (through an existing reference) to *happen before* deleting - // > the object in a different thread. This is achieved by a "release" - // > operation after dropping a reference (any access to the object - // > through this reference must obviously happened before), and an - // > "acquire" operation before deleting the object. - // - // In particular, while the contents of an Arc are usually immutable, it's - // possible to have interior writes to something like a Mutex. Since a - // Mutex is not acquired when it is deleted, we can't rely on its - // synchronization logic to make writes in thread A visible to a destructor - // running in thread B. - // - // Also note that the Acquire fence here could probably be replaced with an - // Acquire load, which could improve performance in highly-contended - // situations. See [2]. - // - // [1]: (www.boost.org/doc/libs/1_55_0/doc/html/atomic/usage_examples.html) - // [2]: (https://github.com/rust-lang/rust/pull/41714) - atomic::fence(Acquire); - - unsafe { - self.drop_slow(); - } - } -} - -impl Arc { - #[inline] - #[unstable(feature = "rc_downcast", issue = "44608")] - /// Attempt to downcast the `Arc` to a concrete type. - /// - /// # Examples - /// - /// ``` - /// #![feature(rc_downcast)] - /// use std::any::Any; - /// use std::sync::Arc; - /// - /// fn print_if_string(value: Arc) { - /// if let Ok(string) = value.downcast::() { - /// println!("String ({}): {}", string.len(), string); - /// } - /// } - /// - /// fn main() { - /// let my_string = "Hello World".to_string(); - /// print_if_string(Arc::new(my_string)); - /// print_if_string(Arc::new(0i8)); - /// } - /// ``` - pub fn downcast(self) -> Result, Self> - where - T: Any + Send + Sync + 'static, - { - if (*self).is::() { - let ptr = self.ptr.cast::>(); - mem::forget(self); - Ok(Arc { ptr, phantom: PhantomData }) - } else { - Err(self) - } - } -} - -impl Weak { - /// Constructs a new `Weak`, without allocating any memory. - /// Calling [`upgrade`] on the return value always gives [`None`]. - /// - /// [`upgrade`]: struct.Weak.html#method.upgrade - /// [`None`]: ../../std/option/enum.Option.html#variant.None - /// - /// # Examples - /// - /// ``` - /// use std::sync::Weak; - /// - /// let empty: Weak = Weak::new(); - /// assert!(empty.upgrade().is_none()); - /// ``` - #[stable(feature = "downgraded_weak", since = "1.10.0")] - pub fn new() -> Weak { - unsafe { - Weak { - ptr: NonNull::new_unchecked(WEAK_EMPTY as *mut _), - } - } - } -} - -impl Weak { - /// Attempts to upgrade the `Weak` pointer to an [`Arc`], extending - /// the lifetime of the value if successful. - /// - /// Returns [`None`] if the value has since been dropped. - /// - /// [`Arc`]: struct.Arc.html - /// [`None`]: ../../std/option/enum.Option.html#variant.None - /// - /// # Examples - /// - /// ``` - /// use std::sync::Arc; - /// - /// let five = Arc::new(5); - /// - /// let weak_five = Arc::downgrade(&five); - /// - /// let strong_five: Option> = weak_five.upgrade(); - /// assert!(strong_five.is_some()); - /// - /// // Destroy all strong pointers. - /// drop(strong_five); - /// drop(five); - /// - /// assert!(weak_five.upgrade().is_none()); - /// ``` - #[stable(feature = "arc_weak", since = "1.4.0")] - pub fn upgrade(&self) -> Option> { - // We use a CAS loop to increment the strong count instead of a - // fetch_add because once the count hits 0 it must never be above 0. - let inner = if self.ptr.as_ptr() as *const u8 as usize == WEAK_EMPTY { - return None; - } else { - unsafe { self.ptr.as_ref() } - }; - - // Relaxed load because any write of 0 that we can observe - // leaves the field in a permanently zero state (so a - // "stale" read of 0 is fine), and any other value is - // confirmed via the CAS below. - let mut n = inner.strong.load(Relaxed); - - loop { - if n == 0 { - return None; - } - - // See comments in `Arc::clone` for why we do this (for `mem::forget`). - if n > MAX_REFCOUNT { - unsafe { - abort(); - } - } - - // Relaxed is valid for the same reason it is on Arc's Clone impl - match inner.strong.compare_exchange_weak(n, n + 1, Relaxed, Relaxed) { - Ok(_) => return Some(Arc { - // null checked above - ptr: self.ptr, - phantom: PhantomData, - }), - Err(old) => n = old, - } - } - } -} - -#[stable(feature = "arc_weak", since = "1.4.0")] -impl Clone for Weak { - /// Makes a clone of the `Weak` pointer that points to the same value. - /// - /// # Examples - /// - /// ``` - /// use std::sync::{Arc, Weak}; - /// - /// let weak_five = Arc::downgrade(&Arc::new(5)); - /// - /// Weak::clone(&weak_five); - /// ``` - #[inline] - fn clone(&self) -> Weak { - let inner = if self.ptr.as_ptr() as *const u8 as usize == WEAK_EMPTY { - return Weak { ptr: self.ptr }; - } else { - unsafe { self.ptr.as_ref() } - }; - // See comments in Arc::clone() for why this is relaxed. This can use a - // fetch_add (ignoring the lock) because the weak count is only locked - // where are *no other* weak pointers in existence. (So we can't be - // running this code in that case). - let old_size = inner.weak.fetch_add(1, Relaxed); - - // See comments in Arc::clone() for why we do this (for mem::forget). - if old_size > MAX_REFCOUNT { - unsafe { - abort(); - } - } - - return Weak { ptr: self.ptr }; - } -} - -#[stable(feature = "downgraded_weak", since = "1.10.0")] -impl Default for Weak { - /// Constructs a new `Weak`, without allocating memory. - /// Calling [`upgrade`] on the return value always gives [`None`]. - /// - /// [`upgrade`]: struct.Weak.html#method.upgrade - /// [`None`]: ../../std/option/enum.Option.html#variant.None - /// - /// # Examples - /// - /// ``` - /// use std::sync::Weak; - /// - /// let empty: Weak = Default::default(); - /// assert!(empty.upgrade().is_none()); - /// ``` - fn default() -> Weak { - Weak::new() - } -} - -#[stable(feature = "arc_weak", since = "1.4.0")] -impl Drop for Weak { - /// Drops the `Weak` pointer. - /// - /// # Examples - /// - /// ``` - /// use std::sync::{Arc, Weak}; - /// - /// struct Foo; - /// - /// impl Drop for Foo { - /// fn drop(&mut self) { - /// println!("dropped!"); - /// } - /// } - /// - /// let foo = Arc::new(Foo); - /// let weak_foo = Arc::downgrade(&foo); - /// let other_weak_foo = Weak::clone(&weak_foo); - /// - /// drop(weak_foo); // Doesn't print anything - /// drop(foo); // Prints "dropped!" - /// - /// assert!(other_weak_foo.upgrade().is_none()); - /// ``` - fn drop(&mut self) { - // If we find out that we were the last weak pointer, then its time to - // deallocate the data entirely. See the discussion in Arc::drop() about - // the memory orderings - // - // It's not necessary to check for the locked state here, because the - // weak count can only be locked if there was precisely one weak ref, - // meaning that drop could only subsequently run ON that remaining weak - // ref, which can only happen after the lock is released. - let inner = if self.ptr.as_ptr() as *const u8 as usize == WEAK_EMPTY { - return; - } else { - unsafe { self.ptr.as_ref() } - }; - - if inner.weak.fetch_sub(1, Release) == 1 { - atomic::fence(Acquire); - unsafe { - Global.dealloc(self.ptr.cast(), Layout::for_value(self.ptr.as_ref())) - } - } - } -} - -#[stable(feature = "rust1", since = "1.0.0")] -impl PartialEq for Arc { - /// Equality for two `Arc`s. - /// - /// Two `Arc`s are equal if their inner values are equal. - /// - /// # Examples - /// - /// ``` - /// use std::sync::Arc; - /// - /// let five = Arc::new(5); - /// - /// assert!(five == Arc::new(5)); - /// ``` - fn eq(&self, other: &Arc) -> bool { - *(*self) == *(*other) - } - - /// Inequality for two `Arc`s. - /// - /// Two `Arc`s are unequal if their inner values are unequal. - /// - /// # Examples - /// - /// ``` - /// use std::sync::Arc; - /// - /// let five = Arc::new(5); - /// - /// assert!(five != Arc::new(6)); - /// ``` - fn ne(&self, other: &Arc) -> bool { - *(*self) != *(*other) - } -} -#[stable(feature = "rust1", since = "1.0.0")] -impl PartialOrd for Arc { - /// Partial comparison for two `Arc`s. - /// - /// The two are compared by calling `partial_cmp()` on their inner values. - /// - /// # Examples - /// - /// ``` - /// use std::sync::Arc; - /// use std::cmp::Ordering; - /// - /// let five = Arc::new(5); - /// - /// assert_eq!(Some(Ordering::Less), five.partial_cmp(&Arc::new(6))); - /// ``` - fn partial_cmp(&self, other: &Arc) -> Option { - (**self).partial_cmp(&**other) - } - - /// Less-than comparison for two `Arc`s. - /// - /// The two are compared by calling `<` on their inner values. - /// - /// # Examples - /// - /// ``` - /// use std::sync::Arc; - /// - /// let five = Arc::new(5); - /// - /// assert!(five < Arc::new(6)); - /// ``` - fn lt(&self, other: &Arc) -> bool { - *(*self) < *(*other) - } - - /// 'Less than or equal to' comparison for two `Arc`s. - /// - /// The two are compared by calling `<=` on their inner values. - /// - /// # Examples - /// - /// ``` - /// use std::sync::Arc; - /// - /// let five = Arc::new(5); - /// - /// assert!(five <= Arc::new(5)); - /// ``` - fn le(&self, other: &Arc) -> bool { - *(*self) <= *(*other) - } - - /// Greater-than comparison for two `Arc`s. - /// - /// The two are compared by calling `>` on their inner values. - /// - /// # Examples - /// - /// ``` - /// use std::sync::Arc; - /// - /// let five = Arc::new(5); - /// - /// assert!(five > Arc::new(4)); - /// ``` - fn gt(&self, other: &Arc) -> bool { - *(*self) > *(*other) - } - - /// 'Greater than or equal to' comparison for two `Arc`s. - /// - /// The two are compared by calling `>=` on their inner values. - /// - /// # Examples - /// - /// ``` - /// use std::sync::Arc; - /// - /// let five = Arc::new(5); - /// - /// assert!(five >= Arc::new(5)); - /// ``` - fn ge(&self, other: &Arc) -> bool { - *(*self) >= *(*other) - } -} -#[stable(feature = "rust1", since = "1.0.0")] -impl Ord for Arc { - /// Comparison for two `Arc`s. - /// - /// The two are compared by calling `cmp()` on their inner values. - /// - /// # Examples - /// - /// ``` - /// use std::sync::Arc; - /// use std::cmp::Ordering; - /// - /// let five = Arc::new(5); - /// - /// assert_eq!(Ordering::Less, five.cmp(&Arc::new(6))); - /// ``` - fn cmp(&self, other: &Arc) -> Ordering { - (**self).cmp(&**other) - } -} -#[stable(feature = "rust1", since = "1.0.0")] -impl Eq for Arc {} - -#[stable(feature = "rust1", since = "1.0.0")] -impl fmt::Display for Arc { - fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { - fmt::Display::fmt(&**self, f) - } -} - -#[stable(feature = "rust1", since = "1.0.0")] -impl fmt::Debug for Arc { - fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { - fmt::Debug::fmt(&**self, f) - } -} - -#[stable(feature = "rust1", since = "1.0.0")] -impl fmt::Pointer for Arc { - fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { - fmt::Pointer::fmt(&(&**self as *const T), f) - } -} - -#[stable(feature = "rust1", since = "1.0.0")] -impl Default for Arc { - /// Creates a new `Arc`, with the `Default` value for `T`. - /// - /// # Examples - /// - /// ``` - /// use std::sync::Arc; - /// - /// let x: Arc = Default::default(); - /// assert_eq!(*x, 0); - /// ``` - fn default() -> Arc { - Arc::new(Default::default()) - } -} - -#[stable(feature = "rust1", since = "1.0.0")] -impl Hash for Arc { - fn hash(&self, state: &mut H) { - (**self).hash(state) - } -} - -#[stable(feature = "from_for_ptrs", since = "1.6.0")] -impl From for Arc { - fn from(t: T) -> Self { - Arc::new(t) - } -} - -#[stable(feature = "shared_from_slice", since = "1.21.0")] -impl<'a, T: Clone> From<&'a [T]> for Arc<[T]> { - #[inline] - fn from(v: &[T]) -> Arc<[T]> { - >::from_slice(v) - } -} - -#[stable(feature = "shared_from_slice", since = "1.21.0")] -impl<'a> From<&'a str> for Arc { - #[inline] - fn from(v: &str) -> Arc { - let arc = Arc::<[u8]>::from(v.as_bytes()); - unsafe { Arc::from_raw(Arc::into_raw(arc) as *const str) } - } -} - -#[stable(feature = "shared_from_slice", since = "1.21.0")] -impl From for Arc { - #[inline] - fn from(v: String) -> Arc { - Arc::from(&v[..]) - } -} - -#[stable(feature = "shared_from_slice", since = "1.21.0")] -impl From> for Arc { - #[inline] - fn from(v: Box) -> Arc { - Arc::from_box(v) - } -} - -#[stable(feature = "shared_from_slice", since = "1.21.0")] -impl From> for Arc<[T]> { - #[inline] - fn from(mut v: Vec) -> Arc<[T]> { - unsafe { - let arc = Arc::copy_from_slice(&v); - - // Allow the Vec to free its memory, but not destroy its contents - v.set_len(0); - - arc - } - } -} - -#[cfg(test)] -mod tests { - use std::boxed::Box; - use std::clone::Clone; - use std::sync::mpsc::channel; - use std::mem::drop; - use std::ops::Drop; - use std::option::Option; - use std::option::Option::{None, Some}; - use std::sync::atomic; - use std::sync::atomic::Ordering::{Acquire, SeqCst}; - use std::thread; - use std::sync::Mutex; - use std::convert::From; - - use super::{Arc, Weak}; - use vec::Vec; - - struct Canary(*mut atomic::AtomicUsize); - - impl Drop for Canary { - fn drop(&mut self) { - unsafe { - match *self { - Canary(c) => { - (*c).fetch_add(1, SeqCst); - } - } - } - } - } - - #[test] - #[cfg_attr(target_os = "emscripten", ignore)] - fn manually_share_arc() { - let v = vec![1, 2, 3, 4, 5, 6, 7, 8, 9, 10]; - let arc_v = Arc::new(v); - - let (tx, rx) = channel(); - - let _t = thread::spawn(move || { - let arc_v: Arc> = rx.recv().unwrap(); - assert_eq!((*arc_v)[3], 4); - }); - - tx.send(arc_v.clone()).unwrap(); - - assert_eq!((*arc_v)[2], 3); - assert_eq!((*arc_v)[4], 5); - } - - #[test] - fn test_arc_get_mut() { - let mut x = Arc::new(3); - *Arc::get_mut(&mut x).unwrap() = 4; - assert_eq!(*x, 4); - let y = x.clone(); - assert!(Arc::get_mut(&mut x).is_none()); - drop(y); - assert!(Arc::get_mut(&mut x).is_some()); - let _w = Arc::downgrade(&x); - assert!(Arc::get_mut(&mut x).is_none()); - } - - #[test] - fn try_unwrap() { - let x = Arc::new(3); - assert_eq!(Arc::try_unwrap(x), Ok(3)); - let x = Arc::new(4); - let _y = x.clone(); - assert_eq!(Arc::try_unwrap(x), Err(Arc::new(4))); - let x = Arc::new(5); - let _w = Arc::downgrade(&x); - assert_eq!(Arc::try_unwrap(x), Ok(5)); - } - - #[test] - fn into_from_raw() { - let x = Arc::new(box "hello"); - let y = x.clone(); - - let x_ptr = Arc::into_raw(x); - drop(y); - unsafe { - assert_eq!(**x_ptr, "hello"); - - let x = Arc::from_raw(x_ptr); - assert_eq!(**x, "hello"); - - assert_eq!(Arc::try_unwrap(x).map(|x| *x), Ok("hello")); - } - } - - #[test] - fn test_into_from_raw_unsized() { - use std::fmt::Display; - use std::string::ToString; - - let arc: Arc = Arc::from("foo"); - - let ptr = Arc::into_raw(arc.clone()); - let arc2 = unsafe { Arc::from_raw(ptr) }; - - assert_eq!(unsafe { &*ptr }, "foo"); - assert_eq!(arc, arc2); - - let arc: Arc = Arc::new(123); - - let ptr = Arc::into_raw(arc.clone()); - let arc2 = unsafe { Arc::from_raw(ptr) }; - - assert_eq!(unsafe { &*ptr }.to_string(), "123"); - assert_eq!(arc2.to_string(), "123"); - } - - #[test] - fn test_cowarc_clone_make_mut() { - let mut cow0 = Arc::new(75); - let mut cow1 = cow0.clone(); - let mut cow2 = cow1.clone(); - - assert!(75 == *Arc::make_mut(&mut cow0)); - assert!(75 == *Arc::make_mut(&mut cow1)); - assert!(75 == *Arc::make_mut(&mut cow2)); - - *Arc::make_mut(&mut cow0) += 1; - *Arc::make_mut(&mut cow1) += 2; - *Arc::make_mut(&mut cow2) += 3; - - assert!(76 == *cow0); - assert!(77 == *cow1); - assert!(78 == *cow2); - - // none should point to the same backing memory - assert!(*cow0 != *cow1); - assert!(*cow0 != *cow2); - assert!(*cow1 != *cow2); - } - - #[test] - fn test_cowarc_clone_unique2() { - let mut cow0 = Arc::new(75); - let cow1 = cow0.clone(); - let cow2 = cow1.clone(); - - assert!(75 == *cow0); - assert!(75 == *cow1); - assert!(75 == *cow2); - - *Arc::make_mut(&mut cow0) += 1; - assert!(76 == *cow0); - assert!(75 == *cow1); - assert!(75 == *cow2); - - // cow1 and cow2 should share the same contents - // cow0 should have a unique reference - assert!(*cow0 != *cow1); - assert!(*cow0 != *cow2); - assert!(*cow1 == *cow2); - } - - #[test] - fn test_cowarc_clone_weak() { - let mut cow0 = Arc::new(75); - let cow1_weak = Arc::downgrade(&cow0); - - assert!(75 == *cow0); - assert!(75 == *cow1_weak.upgrade().unwrap()); - - *Arc::make_mut(&mut cow0) += 1; - - assert!(76 == *cow0); - assert!(cow1_weak.upgrade().is_none()); - } - - #[test] - fn test_live() { - let x = Arc::new(5); - let y = Arc::downgrade(&x); - assert!(y.upgrade().is_some()); - } - - #[test] - fn test_dead() { - let x = Arc::new(5); - let y = Arc::downgrade(&x); - drop(x); - assert!(y.upgrade().is_none()); - } - - #[test] - fn weak_self_cyclic() { - struct Cycle { - x: Mutex>>, - } - - let a = Arc::new(Cycle { x: Mutex::new(None) }); - let b = Arc::downgrade(&a.clone()); - *a.x.lock().unwrap() = Some(b); - - // hopefully we don't double-free (or leak)... - } - - #[test] - fn drop_arc() { - let mut canary = atomic::AtomicUsize::new(0); - let x = Arc::new(Canary(&mut canary as *mut atomic::AtomicUsize)); - drop(x); - assert!(canary.load(Acquire) == 1); - } - - #[test] - fn drop_arc_weak() { - let mut canary = atomic::AtomicUsize::new(0); - let arc = Arc::new(Canary(&mut canary as *mut atomic::AtomicUsize)); - let arc_weak = Arc::downgrade(&arc); - assert!(canary.load(Acquire) == 0); - drop(arc); - assert!(canary.load(Acquire) == 1); - drop(arc_weak); - } - - #[test] - fn test_strong_count() { - let a = Arc::new(0); - assert!(Arc::strong_count(&a) == 1); - let w = Arc::downgrade(&a); - assert!(Arc::strong_count(&a) == 1); - let b = w.upgrade().expect(""); - assert!(Arc::strong_count(&b) == 2); - assert!(Arc::strong_count(&a) == 2); - drop(w); - drop(a); - assert!(Arc::strong_count(&b) == 1); - let c = b.clone(); - assert!(Arc::strong_count(&b) == 2); - assert!(Arc::strong_count(&c) == 2); - } - - #[test] - fn test_weak_count() { - let a = Arc::new(0); - assert!(Arc::strong_count(&a) == 1); - assert!(Arc::weak_count(&a) == 0); - let w = Arc::downgrade(&a); - assert!(Arc::strong_count(&a) == 1); - assert!(Arc::weak_count(&a) == 1); - let x = w.clone(); - assert!(Arc::weak_count(&a) == 2); - drop(w); - drop(x); - assert!(Arc::strong_count(&a) == 1); - assert!(Arc::weak_count(&a) == 0); - let c = a.clone(); - assert!(Arc::strong_count(&a) == 2); - assert!(Arc::weak_count(&a) == 0); - let d = Arc::downgrade(&c); - assert!(Arc::weak_count(&c) == 1); - assert!(Arc::strong_count(&c) == 2); - - drop(a); - drop(c); - drop(d); - } - - #[test] - fn show_arc() { - let a = Arc::new(5); - assert_eq!(format!("{:?}", a), "5"); - } - - // Make sure deriving works with Arc - #[derive(Eq, Ord, PartialEq, PartialOrd, Clone, Debug, Default)] - struct Foo { - inner: Arc, - } - - #[test] - fn test_unsized() { - let x: Arc<[i32]> = Arc::new([1, 2, 3]); - assert_eq!(format!("{:?}", x), "[1, 2, 3]"); - let y = Arc::downgrade(&x.clone()); - drop(x); - assert!(y.upgrade().is_none()); - } - - #[test] - fn test_from_owned() { - let foo = 123; - let foo_arc = Arc::from(foo); - assert!(123 == *foo_arc); - } - - #[test] - fn test_new_weak() { - let foo: Weak = Weak::new(); - assert!(foo.upgrade().is_none()); - } - - #[test] - fn test_ptr_eq() { - let five = Arc::new(5); - let same_five = five.clone(); - let other_five = Arc::new(5); - - assert!(Arc::ptr_eq(&five, &same_five)); - assert!(!Arc::ptr_eq(&five, &other_five)); - } - - #[test] - #[cfg_attr(target_os = "emscripten", ignore)] - fn test_weak_count_locked() { - let mut a = Arc::new(atomic::AtomicBool::new(false)); - let a2 = a.clone(); - let t = thread::spawn(move || { - for _i in 0..1000000 { - Arc::get_mut(&mut a); - } - a.store(true, SeqCst); - }); - - while !a2.load(SeqCst) { - let n = Arc::weak_count(&a2); - assert!(n < 2, "bad weak count: {}", n); - } - t.join().unwrap(); - } - - #[test] - fn test_from_str() { - let r: Arc = Arc::from("foo"); - - assert_eq!(&r[..], "foo"); - } - - #[test] - fn test_copy_from_slice() { - let s: &[u32] = &[1, 2, 3]; - let r: Arc<[u32]> = Arc::from(s); - - assert_eq!(&r[..], [1, 2, 3]); - } - - #[test] - fn test_clone_from_slice() { - #[derive(Clone, Debug, Eq, PartialEq)] - struct X(u32); - - let s: &[X] = &[X(1), X(2), X(3)]; - let r: Arc<[X]> = Arc::from(s); - - assert_eq!(&r[..], s); - } - - #[test] - #[should_panic] - fn test_clone_from_slice_panic() { - use std::string::{String, ToString}; - - struct Fail(u32, String); - - impl Clone for Fail { - fn clone(&self) -> Fail { - if self.0 == 2 { - panic!(); - } - Fail(self.0, self.1.clone()) - } - } - - let s: &[Fail] = &[ - Fail(0, "foo".to_string()), - Fail(1, "bar".to_string()), - Fail(2, "baz".to_string()), - ]; - - // Should panic, but not cause memory corruption - let _r: Arc<[Fail]> = Arc::from(s); - } - - #[test] - fn test_from_box() { - let b: Box = box 123; - let r: Arc = Arc::from(b); - - assert_eq!(*r, 123); - } - - #[test] - fn test_from_box_str() { - use std::string::String; - - let s = String::from("foo").into_boxed_str(); - let r: Arc = Arc::from(s); - - assert_eq!(&r[..], "foo"); - } - - #[test] - fn test_from_box_slice() { - let s = vec![1, 2, 3].into_boxed_slice(); - let r: Arc<[u32]> = Arc::from(s); - - assert_eq!(&r[..], [1, 2, 3]); - } - - #[test] - fn test_from_box_trait() { - use std::fmt::Display; - use std::string::ToString; - - let b: Box = box 123; - let r: Arc = Arc::from(b); - - assert_eq!(r.to_string(), "123"); - } - - #[test] - fn test_from_box_trait_zero_sized() { - use std::fmt::Debug; - - let b: Box = box (); - let r: Arc = Arc::from(b); - - assert_eq!(format!("{:?}", r), "()"); - } - - #[test] - fn test_from_vec() { - let v = vec![1, 2, 3]; - let r: Arc<[u32]> = Arc::from(v); - - assert_eq!(&r[..], [1, 2, 3]); - } - - #[test] - fn test_downcast() { - use std::any::Any; - - let r1: Arc = Arc::new(i32::max_value()); - let r2: Arc = Arc::new("abc"); - - assert!(r1.clone().downcast::().is_err()); - - let r1i32 = r1.downcast::(); - assert!(r1i32.is_ok()); - assert_eq!(r1i32.unwrap(), Arc::new(i32::max_value())); - - assert!(r2.clone().downcast::().is_err()); - - let r2str = r2.downcast::<&'static str>(); - assert!(r2str.is_ok()); - assert_eq!(r2str.unwrap(), Arc::new("abc")); - } -} - -#[stable(feature = "rust1", since = "1.0.0")] -impl borrow::Borrow for Arc { - fn borrow(&self) -> &T { - &**self - } -} - -#[stable(since = "1.5.0", feature = "smart_ptr_as_ref")] -impl AsRef for Arc { - fn as_ref(&self) -> &T { - &**self - } -} diff --git a/src/liballoc/lib.rs b/src/liballoc/lib.rs index 9e1740473fe..8ec5a9ed193 100644 --- a/src/liballoc/lib.rs +++ b/src/liballoc/lib.rs @@ -40,7 +40,7 @@ //! //! ## Atomically reference counted pointers //! -//! The [`Arc`](arc/index.html) type is the threadsafe equivalent of the `Rc` +//! The [`Arc`](sync/index.html) type is the threadsafe equivalent of the `Rc` //! type. It provides all the same functionality of `Rc`, except it requires //! that the contained type `T` is shareable. Additionally, `Arc` is itself //! sendable while `Rc` is not. @@ -164,7 +164,7 @@ mod boxed { mod boxed_test; pub mod collections; #[cfg(target_has_atomic = "ptr")] -pub mod arc; +pub mod sync; pub mod rc; pub mod raw_vec; diff --git a/src/liballoc/sync.rs b/src/liballoc/sync.rs new file mode 100644 index 00000000000..2abd9c85c57 --- /dev/null +++ b/src/liballoc/sync.rs @@ -0,0 +1,1936 @@ +// Copyright 2012-2014 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. + +#![stable(feature = "rust1", since = "1.0.0")] + +//! Thread-safe reference-counting pointers. +//! +//! See the [`Arc`][arc] documentation for more details. +//! +//! [arc]: struct.Arc.html + +use core::any::Any; +use core::sync::atomic; +use core::sync::atomic::Ordering::{Acquire, Relaxed, Release, SeqCst}; +use core::borrow; +use core::fmt; +use core::cmp::Ordering; +use core::intrinsics::abort; +use core::mem::{self, align_of_val, size_of_val}; +use core::ops::Deref; +use core::ops::CoerceUnsized; +use core::ptr::{self, NonNull}; +use core::marker::{Unsize, PhantomData}; +use core::hash::{Hash, Hasher}; +use core::{isize, usize}; +use core::convert::From; + +use alloc::{Global, Alloc, Layout, box_free, handle_alloc_error}; +use boxed::Box; +use string::String; +use vec::Vec; + +/// A soft limit on the amount of references that may be made to an `Arc`. +/// +/// Going above this limit will abort your program (although not +/// necessarily) at _exactly_ `MAX_REFCOUNT + 1` references. +const MAX_REFCOUNT: usize = (isize::MAX) as usize; + +/// A sentinel value that is used for the pointer of `Weak::new()`. +const WEAK_EMPTY: usize = 1; + +/// A thread-safe reference-counting pointer. 'Arc' stands for 'Atomically +/// Reference Counted'. +/// +/// The type `Arc` provides shared ownership of a value of type `T`, +/// allocated in the heap. Invoking [`clone`][clone] on `Arc` produces +/// a new pointer to the same value in the heap. When the last `Arc` +/// pointer to a given value is destroyed, the pointed-to value is +/// also destroyed. +/// +/// Shared references in Rust disallow mutation by default, and `Arc` is no +/// exception: you cannot generally obtain a mutable reference to something +/// inside an `Arc`. If you need to mutate through an `Arc`, use +/// [`Mutex`][mutex], [`RwLock`][rwlock], or one of the [`Atomic`][atomic] +/// types. +/// +/// ## Thread Safety +/// +/// Unlike [`Rc`], `Arc` uses atomic operations for its reference +/// counting. This means that it is thread-safe. The disadvantage is that +/// atomic operations are more expensive than ordinary memory accesses. If you +/// are not sharing reference-counted values between threads, consider using +/// [`Rc`] for lower overhead. [`Rc`] is a safe default, because the +/// compiler will catch any attempt to send an [`Rc`] between threads. +/// However, a library might choose `Arc` in order to give library consumers +/// more flexibility. +/// +/// `Arc` will implement [`Send`] and [`Sync`] as long as the `T` implements +/// [`Send`] and [`Sync`]. Why can't you put a non-thread-safe type `T` in an +/// `Arc` to make it thread-safe? This may be a bit counter-intuitive at +/// first: after all, isn't the point of `Arc` thread safety? The key is +/// this: `Arc` makes it thread safe to have multiple ownership of the same +/// data, but it doesn't add thread safety to its data. Consider +/// `Arc<`[`RefCell`]`>`. [`RefCell`] isn't [`Sync`], and if `Arc` was always +/// [`Send`], `Arc<`[`RefCell`]`>` would be as well. But then we'd have a problem: +/// [`RefCell`] is not thread safe; it keeps track of the borrowing count using +/// non-atomic operations. +/// +/// In the end, this means that you may need to pair `Arc` with some sort of +/// [`std::sync`] type, usually [`Mutex`][mutex]. +/// +/// ## Breaking cycles with `Weak` +/// +/// The [`downgrade`][downgrade] method can be used to create a non-owning +/// [`Weak`][weak] pointer. A [`Weak`][weak] pointer can be [`upgrade`][upgrade]d +/// to an `Arc`, but this will return [`None`] if the value has already been +/// dropped. +/// +/// A cycle between `Arc` pointers will never be deallocated. For this reason, +/// [`Weak`][weak] is used to break cycles. For example, a tree could have +/// strong `Arc` pointers from parent nodes to children, and [`Weak`][weak] +/// pointers from children back to their parents. +/// +/// # Cloning references +/// +/// Creating a new reference from an existing reference counted pointer is done using the +/// `Clone` trait implemented for [`Arc`][arc] and [`Weak`][weak]. +/// +/// ``` +/// use std::sync::Arc; +/// let foo = Arc::new(vec![1.0, 2.0, 3.0]); +/// // The two syntaxes below are equivalent. +/// let a = foo.clone(); +/// let b = Arc::clone(&foo); +/// // a and b both point to the same memory location as foo. +/// ``` +/// +/// The [`Arc::clone(&from)`] syntax is the most idiomatic because it conveys more explicitly +/// the meaning of the code. In the example above, this syntax makes it easier to see that +/// this code is creating a new reference rather than copying the whole content of foo. +/// +/// ## `Deref` behavior +/// +/// `Arc` automatically dereferences to `T` (via the [`Deref`][deref] trait), +/// so you can call `T`'s methods on a value of type `Arc`. To avoid name +/// clashes with `T`'s methods, the methods of `Arc` itself are [associated +/// functions][assoc], called using function-like syntax: +/// +/// ``` +/// use std::sync::Arc; +/// let my_arc = Arc::new(()); +/// +/// Arc::downgrade(&my_arc); +/// ``` +/// +/// [`Weak`][weak] does not auto-dereference to `T`, because the value may have +/// already been destroyed. +/// +/// [arc]: struct.Arc.html +/// [weak]: struct.Weak.html +/// [`Rc`]: ../../std/rc/struct.Rc.html +/// [clone]: ../../std/clone/trait.Clone.html#tymethod.clone +/// [mutex]: ../../std/sync/struct.Mutex.html +/// [rwlock]: ../../std/sync/struct.RwLock.html +/// [atomic]: ../../std/sync/atomic/index.html +/// [`Send`]: ../../std/marker/trait.Send.html +/// [`Sync`]: ../../std/marker/trait.Sync.html +/// [deref]: ../../std/ops/trait.Deref.html +/// [downgrade]: struct.Arc.html#method.downgrade +/// [upgrade]: struct.Weak.html#method.upgrade +/// [`None`]: ../../std/option/enum.Option.html#variant.None +/// [assoc]: ../../book/first-edition/method-syntax.html#associated-functions +/// [`RefCell`]: ../../std/cell/struct.RefCell.html +/// [`std::sync`]: ../../std/sync/index.html +/// [`Arc::clone(&from)`]: #method.clone +/// +/// # Examples +/// +/// Sharing some immutable data between threads: +/// +// Note that we **do not** run these tests here. The windows builders get super +// unhappy if a thread outlives the main thread and then exits at the same time +// (something deadlocks) so we just avoid this entirely by not running these +// tests. +/// ```no_run +/// use std::sync::Arc; +/// use std::thread; +/// +/// let five = Arc::new(5); +/// +/// for _ in 0..10 { +/// let five = Arc::clone(&five); +/// +/// thread::spawn(move || { +/// println!("{:?}", five); +/// }); +/// } +/// ``` +/// +/// Sharing a mutable [`AtomicUsize`]: +/// +/// [`AtomicUsize`]: ../../std/sync/atomic/struct.AtomicUsize.html +/// +/// ```no_run +/// use std::sync::Arc; +/// use std::sync::atomic::{AtomicUsize, Ordering}; +/// use std::thread; +/// +/// let val = Arc::new(AtomicUsize::new(5)); +/// +/// for _ in 0..10 { +/// let val = Arc::clone(&val); +/// +/// thread::spawn(move || { +/// let v = val.fetch_add(1, Ordering::SeqCst); +/// println!("{:?}", v); +/// }); +/// } +/// ``` +/// +/// See the [`rc` documentation][rc_examples] for more examples of reference +/// counting in general. +/// +/// [rc_examples]: ../../std/rc/index.html#examples +#[stable(feature = "rust1", since = "1.0.0")] +pub struct Arc { + ptr: NonNull>, + phantom: PhantomData, +} + +#[stable(feature = "rust1", since = "1.0.0")] +unsafe impl Send for Arc {} +#[stable(feature = "rust1", since = "1.0.0")] +unsafe impl Sync for Arc {} + +#[unstable(feature = "coerce_unsized", issue = "27732")] +impl, U: ?Sized> CoerceUnsized> for Arc {} + +/// `Weak` is a version of [`Arc`] that holds a non-owning reference to the +/// managed value. The value is accessed by calling [`upgrade`] on the `Weak` +/// pointer, which returns an [`Option`]`<`[`Arc`]`>`. +/// +/// Since a `Weak` reference does not count towards ownership, it will not +/// prevent the inner value from being dropped, and `Weak` itself makes no +/// guarantees about the value still being present and may return [`None`] +/// when [`upgrade`]d. +/// +/// A `Weak` pointer is useful for keeping a temporary reference to the value +/// within [`Arc`] without extending its lifetime. It is also used to prevent +/// circular references between [`Arc`] pointers, since mutual owning references +/// would never allow either [`Arc`] to be dropped. For example, a tree could +/// have strong [`Arc`] pointers from parent nodes to children, and `Weak` +/// pointers from children back to their parents. +/// +/// The typical way to obtain a `Weak` pointer is to call [`Arc::downgrade`]. +/// +/// [`Arc`]: struct.Arc.html +/// [`Arc::downgrade`]: struct.Arc.html#method.downgrade +/// [`upgrade`]: struct.Weak.html#method.upgrade +/// [`Option`]: ../../std/option/enum.Option.html +/// [`None`]: ../../std/option/enum.Option.html#variant.None +#[stable(feature = "arc_weak", since = "1.4.0")] +pub struct Weak { + // This is a `NonNull` to allow optimizing the size of this type in enums, + // but it is actually not truly "non-null". A `Weak::new()` will set this + // to a sentinel value, instead of needing to allocate some space in the + // heap. + ptr: NonNull>, +} + +#[stable(feature = "arc_weak", since = "1.4.0")] +unsafe impl Send for Weak {} +#[stable(feature = "arc_weak", since = "1.4.0")] +unsafe impl Sync for Weak {} + +#[unstable(feature = "coerce_unsized", issue = "27732")] +impl, U: ?Sized> CoerceUnsized> for Weak {} + +#[stable(feature = "arc_weak", since = "1.4.0")] +impl fmt::Debug for Weak { + fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { + write!(f, "(Weak)") + } +} + +struct ArcInner { + strong: atomic::AtomicUsize, + + // the value usize::MAX acts as a sentinel for temporarily "locking" the + // ability to upgrade weak pointers or downgrade strong ones; this is used + // to avoid races in `make_mut` and `get_mut`. + weak: atomic::AtomicUsize, + + data: T, +} + +unsafe impl Send for ArcInner {} +unsafe impl Sync for ArcInner {} + +impl Arc { + /// Constructs a new `Arc`. + /// + /// # Examples + /// + /// ``` + /// use std::sync::Arc; + /// + /// let five = Arc::new(5); + /// ``` + #[inline] + #[stable(feature = "rust1", since = "1.0.0")] + pub fn new(data: T) -> Arc { + // Start the weak pointer count as 1 which is the weak pointer that's + // held by all the strong pointers (kinda), see std/rc.rs for more info + let x: Box<_> = box ArcInner { + strong: atomic::AtomicUsize::new(1), + weak: atomic::AtomicUsize::new(1), + data, + }; + Arc { ptr: Box::into_raw_non_null(x), phantom: PhantomData } + } + + /// Returns the contained value, if the `Arc` has exactly one strong reference. + /// + /// Otherwise, an [`Err`][result] is returned with the same `Arc` that was + /// passed in. + /// + /// This will succeed even if there are outstanding weak references. + /// + /// [result]: ../../std/result/enum.Result.html + /// + /// # Examples + /// + /// ``` + /// use std::sync::Arc; + /// + /// let x = Arc::new(3); + /// assert_eq!(Arc::try_unwrap(x), Ok(3)); + /// + /// let x = Arc::new(4); + /// let _y = Arc::clone(&x); + /// assert_eq!(*Arc::try_unwrap(x).unwrap_err(), 4); + /// ``` + #[inline] + #[stable(feature = "arc_unique", since = "1.4.0")] + pub fn try_unwrap(this: Self) -> Result { + // See `drop` for why all these atomics are like this + if this.inner().strong.compare_exchange(1, 0, Release, Relaxed).is_err() { + return Err(this); + } + + atomic::fence(Acquire); + + unsafe { + let elem = ptr::read(&this.ptr.as_ref().data); + + // Make a weak pointer to clean up the implicit strong-weak reference + let _weak = Weak { ptr: this.ptr }; + mem::forget(this); + + Ok(elem) + } + } +} + +impl Arc { + /// Consumes the `Arc`, returning the wrapped pointer. + /// + /// To avoid a memory leak the pointer must be converted back to an `Arc` using + /// [`Arc::from_raw`][from_raw]. + /// + /// [from_raw]: struct.Arc.html#method.from_raw + /// + /// # Examples + /// + /// ``` + /// use std::sync::Arc; + /// + /// let x = Arc::new(10); + /// let x_ptr = Arc::into_raw(x); + /// assert_eq!(unsafe { *x_ptr }, 10); + /// ``` + #[stable(feature = "rc_raw", since = "1.17.0")] + pub fn into_raw(this: Self) -> *const T { + let ptr: *const T = &*this; + mem::forget(this); + ptr + } + + /// Constructs an `Arc` from a raw pointer. + /// + /// The raw pointer must have been previously returned by a call to a + /// [`Arc::into_raw`][into_raw]. + /// + /// This function is unsafe because improper use may lead to memory problems. For example, a + /// double-free may occur if the function is called twice on the same raw pointer. + /// + /// [into_raw]: struct.Arc.html#method.into_raw + /// + /// # Examples + /// + /// ``` + /// use std::sync::Arc; + /// + /// let x = Arc::new(10); + /// let x_ptr = Arc::into_raw(x); + /// + /// unsafe { + /// // Convert back to an `Arc` to prevent leak. + /// let x = Arc::from_raw(x_ptr); + /// assert_eq!(*x, 10); + /// + /// // Further calls to `Arc::from_raw(x_ptr)` would be memory unsafe. + /// } + /// + /// // The memory was freed when `x` went out of scope above, so `x_ptr` is now dangling! + /// ``` + #[stable(feature = "rc_raw", since = "1.17.0")] + pub unsafe fn from_raw(ptr: *const T) -> Self { + // Align the unsized value to the end of the ArcInner. + // Because it is ?Sized, it will always be the last field in memory. + let align = align_of_val(&*ptr); + let layout = Layout::new::>(); + let offset = (layout.size() + layout.padding_needed_for(align)) as isize; + + // Reverse the offset to find the original ArcInner. + let fake_ptr = ptr as *mut ArcInner; + let arc_ptr = set_data_ptr(fake_ptr, (ptr as *mut u8).offset(-offset)); + + Arc { + ptr: NonNull::new_unchecked(arc_ptr), + phantom: PhantomData, + } + } + + /// Creates a new [`Weak`][weak] pointer to this value. + /// + /// [weak]: struct.Weak.html + /// + /// # Examples + /// + /// ``` + /// use std::sync::Arc; + /// + /// let five = Arc::new(5); + /// + /// let weak_five = Arc::downgrade(&five); + /// ``` + #[stable(feature = "arc_weak", since = "1.4.0")] + pub fn downgrade(this: &Self) -> Weak { + // This Relaxed is OK because we're checking the value in the CAS + // below. + let mut cur = this.inner().weak.load(Relaxed); + + loop { + // check if the weak counter is currently "locked"; if so, spin. + if cur == usize::MAX { + cur = this.inner().weak.load(Relaxed); + continue; + } + + // NOTE: this code currently ignores the possibility of overflow + // into usize::MAX; in general both Rc and Arc need to be adjusted + // to deal with overflow. + + // Unlike with Clone(), we need this to be an Acquire read to + // synchronize with the write coming from `is_unique`, so that the + // events prior to that write happen before this read. + match this.inner().weak.compare_exchange_weak(cur, cur + 1, Acquire, Relaxed) { + Ok(_) => return Weak { ptr: this.ptr }, + Err(old) => cur = old, + } + } + } + + /// Gets the number of [`Weak`][weak] pointers to this value. + /// + /// [weak]: struct.Weak.html + /// + /// # Safety + /// + /// This method by itself is safe, but using it correctly requires extra care. + /// Another thread can change the weak count at any time, + /// including potentially between calling this method and acting on the result. + /// + /// # Examples + /// + /// ``` + /// use std::sync::Arc; + /// + /// let five = Arc::new(5); + /// let _weak_five = Arc::downgrade(&five); + /// + /// // This assertion is deterministic because we haven't shared + /// // the `Arc` or `Weak` between threads. + /// assert_eq!(1, Arc::weak_count(&five)); + /// ``` + #[inline] + #[stable(feature = "arc_counts", since = "1.15.0")] + pub fn weak_count(this: &Self) -> usize { + let cnt = this.inner().weak.load(SeqCst); + // If the weak count is currently locked, the value of the + // count was 0 just before taking the lock. + if cnt == usize::MAX { 0 } else { cnt - 1 } + } + + /// Gets the number of strong (`Arc`) pointers to this value. + /// + /// # Safety + /// + /// This method by itself is safe, but using it correctly requires extra care. + /// Another thread can change the strong count at any time, + /// including potentially between calling this method and acting on the result. + /// + /// # Examples + /// + /// ``` + /// use std::sync::Arc; + /// + /// let five = Arc::new(5); + /// let _also_five = Arc::clone(&five); + /// + /// // This assertion is deterministic because we haven't shared + /// // the `Arc` between threads. + /// assert_eq!(2, Arc::strong_count(&five)); + /// ``` + #[inline] + #[stable(feature = "arc_counts", since = "1.15.0")] + pub fn strong_count(this: &Self) -> usize { + this.inner().strong.load(SeqCst) + } + + #[inline] + fn inner(&self) -> &ArcInner { + // This unsafety is ok because while this arc is alive we're guaranteed + // that the inner pointer is valid. Furthermore, we know that the + // `ArcInner` structure itself is `Sync` because the inner data is + // `Sync` as well, so we're ok loaning out an immutable pointer to these + // contents. + unsafe { self.ptr.as_ref() } + } + + // Non-inlined part of `drop`. + #[inline(never)] + unsafe fn drop_slow(&mut self) { + // Destroy the data at this time, even though we may not free the box + // allocation itself (there may still be weak pointers lying around). + ptr::drop_in_place(&mut self.ptr.as_mut().data); + + if self.inner().weak.fetch_sub(1, Release) == 1 { + atomic::fence(Acquire); + Global.dealloc(self.ptr.cast(), Layout::for_value(self.ptr.as_ref())) + } + } + + #[inline] + #[stable(feature = "ptr_eq", since = "1.17.0")] + /// Returns true if the two `Arc`s point to the same value (not + /// just values that compare as equal). + /// + /// # Examples + /// + /// ``` + /// use std::sync::Arc; + /// + /// let five = Arc::new(5); + /// let same_five = Arc::clone(&five); + /// let other_five = Arc::new(5); + /// + /// assert!(Arc::ptr_eq(&five, &same_five)); + /// assert!(!Arc::ptr_eq(&five, &other_five)); + /// ``` + pub fn ptr_eq(this: &Self, other: &Self) -> bool { + this.ptr.as_ptr() == other.ptr.as_ptr() + } +} + +impl Arc { + // Allocates an `ArcInner` with sufficient space for an unsized value + unsafe fn allocate_for_ptr(ptr: *const T) -> *mut ArcInner { + // Create a fake ArcInner to find allocation size and alignment + let fake_ptr = ptr as *mut ArcInner; + + let layout = Layout::for_value(&*fake_ptr); + + let mem = Global.alloc(layout) + .unwrap_or_else(|_| handle_alloc_error(layout)); + + // Initialize the real ArcInner + let inner = set_data_ptr(ptr as *mut T, mem.as_ptr() as *mut u8) as *mut ArcInner; + + ptr::write(&mut (*inner).strong, atomic::AtomicUsize::new(1)); + ptr::write(&mut (*inner).weak, atomic::AtomicUsize::new(1)); + + inner + } + + fn from_box(v: Box) -> Arc { + unsafe { + let box_unique = Box::into_unique(v); + let bptr = box_unique.as_ptr(); + + let value_size = size_of_val(&*bptr); + let ptr = Self::allocate_for_ptr(bptr); + + // Copy value as bytes + ptr::copy_nonoverlapping( + bptr as *const T as *const u8, + &mut (*ptr).data as *mut _ as *mut u8, + value_size); + + // Free the allocation without dropping its contents + box_free(box_unique); + + Arc { ptr: NonNull::new_unchecked(ptr), phantom: PhantomData } + } + } +} + +// Sets the data pointer of a `?Sized` raw pointer. +// +// For a slice/trait object, this sets the `data` field and leaves the rest +// unchanged. For a sized raw pointer, this simply sets the pointer. +unsafe fn set_data_ptr(mut ptr: *mut T, data: *mut U) -> *mut T { + ptr::write(&mut ptr as *mut _ as *mut *mut u8, data as *mut u8); + ptr +} + +impl Arc<[T]> { + // Copy elements from slice into newly allocated Arc<[T]> + // + // Unsafe because the caller must either take ownership or bind `T: Copy` + unsafe fn copy_from_slice(v: &[T]) -> Arc<[T]> { + let v_ptr = v as *const [T]; + let ptr = Self::allocate_for_ptr(v_ptr); + + ptr::copy_nonoverlapping( + v.as_ptr(), + &mut (*ptr).data as *mut [T] as *mut T, + v.len()); + + Arc { ptr: NonNull::new_unchecked(ptr), phantom: PhantomData } + } +} + +// Specialization trait used for From<&[T]> +trait ArcFromSlice { + fn from_slice(slice: &[T]) -> Self; +} + +impl ArcFromSlice for Arc<[T]> { + #[inline] + default fn from_slice(v: &[T]) -> Self { + // Panic guard while cloning T elements. + // In the event of a panic, elements that have been written + // into the new ArcInner will be dropped, then the memory freed. + struct Guard { + mem: NonNull, + elems: *mut T, + layout: Layout, + n_elems: usize, + } + + impl Drop for Guard { + fn drop(&mut self) { + use core::slice::from_raw_parts_mut; + + unsafe { + let slice = from_raw_parts_mut(self.elems, self.n_elems); + ptr::drop_in_place(slice); + + Global.dealloc(self.mem.cast(), self.layout.clone()); + } + } + } + + unsafe { + let v_ptr = v as *const [T]; + let ptr = Self::allocate_for_ptr(v_ptr); + + let mem = ptr as *mut _ as *mut u8; + let layout = Layout::for_value(&*ptr); + + // Pointer to first element + let elems = &mut (*ptr).data as *mut [T] as *mut T; + + let mut guard = Guard{ + mem: NonNull::new_unchecked(mem), + elems: elems, + layout: layout, + n_elems: 0, + }; + + for (i, item) in v.iter().enumerate() { + ptr::write(elems.offset(i as isize), item.clone()); + guard.n_elems += 1; + } + + // All clear. Forget the guard so it doesn't free the new ArcInner. + mem::forget(guard); + + Arc { ptr: NonNull::new_unchecked(ptr), phantom: PhantomData } + } + } +} + +impl ArcFromSlice for Arc<[T]> { + #[inline] + fn from_slice(v: &[T]) -> Self { + unsafe { Arc::copy_from_slice(v) } + } +} + +#[stable(feature = "rust1", since = "1.0.0")] +impl Clone for Arc { + /// Makes a clone of the `Arc` pointer. + /// + /// This creates another pointer to the same inner value, increasing the + /// strong reference count. + /// + /// # Examples + /// + /// ``` + /// use std::sync::Arc; + /// + /// let five = Arc::new(5); + /// + /// Arc::clone(&five); + /// ``` + #[inline] + fn clone(&self) -> Arc { + // Using a relaxed ordering is alright here, as knowledge of the + // original reference prevents other threads from erroneously deleting + // the object. + // + // As explained in the [Boost documentation][1], Increasing the + // reference counter can always be done with memory_order_relaxed: New + // references to an object can only be formed from an existing + // reference, and passing an existing reference from one thread to + // another must already provide any required synchronization. + // + // [1]: (www.boost.org/doc/libs/1_55_0/doc/html/atomic/usage_examples.html) + let old_size = self.inner().strong.fetch_add(1, Relaxed); + + // However we need to guard against massive refcounts in case someone + // is `mem::forget`ing Arcs. If we don't do this the count can overflow + // and users will use-after free. We racily saturate to `isize::MAX` on + // the assumption that there aren't ~2 billion threads incrementing + // the reference count at once. This branch will never be taken in + // any realistic program. + // + // We abort because such a program is incredibly degenerate, and we + // don't care to support it. + if old_size > MAX_REFCOUNT { + unsafe { + abort(); + } + } + + Arc { ptr: self.ptr, phantom: PhantomData } + } +} + +#[stable(feature = "rust1", since = "1.0.0")] +impl Deref for Arc { + type Target = T; + + #[inline] + fn deref(&self) -> &T { + &self.inner().data + } +} + +impl Arc { + /// Makes a mutable reference into the given `Arc`. + /// + /// If there are other `Arc` or [`Weak`][weak] pointers to the same value, + /// then `make_mut` will invoke [`clone`][clone] on the inner value to + /// ensure unique ownership. This is also referred to as clone-on-write. + /// + /// See also [`get_mut`][get_mut], which will fail rather than cloning. + /// + /// [weak]: struct.Weak.html + /// [clone]: ../../std/clone/trait.Clone.html#tymethod.clone + /// [get_mut]: struct.Arc.html#method.get_mut + /// + /// # Examples + /// + /// ``` + /// use std::sync::Arc; + /// + /// let mut data = Arc::new(5); + /// + /// *Arc::make_mut(&mut data) += 1; // Won't clone anything + /// let mut other_data = Arc::clone(&data); // Won't clone inner data + /// *Arc::make_mut(&mut data) += 1; // Clones inner data + /// *Arc::make_mut(&mut data) += 1; // Won't clone anything + /// *Arc::make_mut(&mut other_data) *= 2; // Won't clone anything + /// + /// // Now `data` and `other_data` point to different values. + /// assert_eq!(*data, 8); + /// assert_eq!(*other_data, 12); + /// ``` + #[inline] + #[stable(feature = "arc_unique", since = "1.4.0")] + pub fn make_mut(this: &mut Self) -> &mut T { + // Note that we hold both a strong reference and a weak reference. + // Thus, releasing our strong reference only will not, by itself, cause + // the memory to be deallocated. + // + // Use Acquire to ensure that we see any writes to `weak` that happen + // before release writes (i.e., decrements) to `strong`. Since we hold a + // weak count, there's no chance the ArcInner itself could be + // deallocated. + if this.inner().strong.compare_exchange(1, 0, Acquire, Relaxed).is_err() { + // Another strong pointer exists; clone + *this = Arc::new((**this).clone()); + } else if this.inner().weak.load(Relaxed) != 1 { + // Relaxed suffices in the above because this is fundamentally an + // optimization: we are always racing with weak pointers being + // dropped. Worst case, we end up allocated a new Arc unnecessarily. + + // We removed the last strong ref, but there are additional weak + // refs remaining. We'll move the contents to a new Arc, and + // invalidate the other weak refs. + + // Note that it is not possible for the read of `weak` to yield + // usize::MAX (i.e., locked), since the weak count can only be + // locked by a thread with a strong reference. + + // Materialize our own implicit weak pointer, so that it can clean + // up the ArcInner as needed. + let weak = Weak { ptr: this.ptr }; + + // mark the data itself as already deallocated + unsafe { + // there is no data race in the implicit write caused by `read` + // here (due to zeroing) because data is no longer accessed by + // other threads (due to there being no more strong refs at this + // point). + let mut swap = Arc::new(ptr::read(&weak.ptr.as_ref().data)); + mem::swap(this, &mut swap); + mem::forget(swap); + } + } else { + // We were the sole reference of either kind; bump back up the + // strong ref count. + this.inner().strong.store(1, Release); + } + + // As with `get_mut()`, the unsafety is ok because our reference was + // either unique to begin with, or became one upon cloning the contents. + unsafe { + &mut this.ptr.as_mut().data + } + } +} + +impl Arc { + /// Returns a mutable reference to the inner value, if there are + /// no other `Arc` or [`Weak`][weak] pointers to the same value. + /// + /// Returns [`None`][option] otherwise, because it is not safe to + /// mutate a shared value. + /// + /// See also [`make_mut`][make_mut], which will [`clone`][clone] + /// the inner value when it's shared. + /// + /// [weak]: struct.Weak.html + /// [option]: ../../std/option/enum.Option.html + /// [make_mut]: struct.Arc.html#method.make_mut + /// [clone]: ../../std/clone/trait.Clone.html#tymethod.clone + /// + /// # Examples + /// + /// ``` + /// use std::sync::Arc; + /// + /// let mut x = Arc::new(3); + /// *Arc::get_mut(&mut x).unwrap() = 4; + /// assert_eq!(*x, 4); + /// + /// let _y = Arc::clone(&x); + /// assert!(Arc::get_mut(&mut x).is_none()); + /// ``` + #[inline] + #[stable(feature = "arc_unique", since = "1.4.0")] + pub fn get_mut(this: &mut Self) -> Option<&mut T> { + if this.is_unique() { + // This unsafety is ok because we're guaranteed that the pointer + // returned is the *only* pointer that will ever be returned to T. Our + // reference count is guaranteed to be 1 at this point, and we required + // the Arc itself to be `mut`, so we're returning the only possible + // reference to the inner data. + unsafe { + Some(&mut this.ptr.as_mut().data) + } + } else { + None + } + } + + /// Determine whether this is the unique reference (including weak refs) to + /// the underlying data. + /// + /// Note that this requires locking the weak ref count. + fn is_unique(&mut self) -> bool { + // lock the weak pointer count if we appear to be the sole weak pointer + // holder. + // + // The acquire label here ensures a happens-before relationship with any + // writes to `strong` prior to decrements of the `weak` count (via drop, + // which uses Release). + if self.inner().weak.compare_exchange(1, usize::MAX, Acquire, Relaxed).is_ok() { + // Due to the previous acquire read, this will observe any writes to + // `strong` that were due to upgrading weak pointers; only strong + // clones remain, which require that the strong count is > 1 anyway. + let unique = self.inner().strong.load(Relaxed) == 1; + + // The release write here synchronizes with a read in `downgrade`, + // effectively preventing the above read of `strong` from happening + // after the write. + self.inner().weak.store(1, Release); // release the lock + unique + } else { + false + } + } +} + +#[stable(feature = "rust1", since = "1.0.0")] +unsafe impl<#[may_dangle] T: ?Sized> Drop for Arc { + /// Drops the `Arc`. + /// + /// This will decrement the strong reference count. If the strong reference + /// count reaches zero then the only other references (if any) are + /// [`Weak`][weak], so we `drop` the inner value. + /// + /// [weak]: struct.Weak.html + /// + /// # Examples + /// + /// ``` + /// use std::sync::Arc; + /// + /// struct Foo; + /// + /// impl Drop for Foo { + /// fn drop(&mut self) { + /// println!("dropped!"); + /// } + /// } + /// + /// let foo = Arc::new(Foo); + /// let foo2 = Arc::clone(&foo); + /// + /// drop(foo); // Doesn't print anything + /// drop(foo2); // Prints "dropped!" + /// ``` + #[inline] + fn drop(&mut self) { + // Because `fetch_sub` is already atomic, we do not need to synchronize + // with other threads unless we are going to delete the object. This + // same logic applies to the below `fetch_sub` to the `weak` count. + if self.inner().strong.fetch_sub(1, Release) != 1 { + return; + } + + // This fence is needed to prevent reordering of use of the data and + // deletion of the data. Because it is marked `Release`, the decreasing + // of the reference count synchronizes with this `Acquire` fence. This + // means that use of the data happens before decreasing the reference + // count, which happens before this fence, which happens before the + // deletion of the data. + // + // As explained in the [Boost documentation][1], + // + // > It is important to enforce any possible access to the object in one + // > thread (through an existing reference) to *happen before* deleting + // > the object in a different thread. This is achieved by a "release" + // > operation after dropping a reference (any access to the object + // > through this reference must obviously happened before), and an + // > "acquire" operation before deleting the object. + // + // In particular, while the contents of an Arc are usually immutable, it's + // possible to have interior writes to something like a Mutex. Since a + // Mutex is not acquired when it is deleted, we can't rely on its + // synchronization logic to make writes in thread A visible to a destructor + // running in thread B. + // + // Also note that the Acquire fence here could probably be replaced with an + // Acquire load, which could improve performance in highly-contended + // situations. See [2]. + // + // [1]: (www.boost.org/doc/libs/1_55_0/doc/html/atomic/usage_examples.html) + // [2]: (https://github.com/rust-lang/rust/pull/41714) + atomic::fence(Acquire); + + unsafe { + self.drop_slow(); + } + } +} + +impl Arc { + #[inline] + #[unstable(feature = "rc_downcast", issue = "44608")] + /// Attempt to downcast the `Arc` to a concrete type. + /// + /// # Examples + /// + /// ``` + /// #![feature(rc_downcast)] + /// use std::any::Any; + /// use std::sync::Arc; + /// + /// fn print_if_string(value: Arc) { + /// if let Ok(string) = value.downcast::() { + /// println!("String ({}): {}", string.len(), string); + /// } + /// } + /// + /// fn main() { + /// let my_string = "Hello World".to_string(); + /// print_if_string(Arc::new(my_string)); + /// print_if_string(Arc::new(0i8)); + /// } + /// ``` + pub fn downcast(self) -> Result, Self> + where + T: Any + Send + Sync + 'static, + { + if (*self).is::() { + let ptr = self.ptr.cast::>(); + mem::forget(self); + Ok(Arc { ptr, phantom: PhantomData }) + } else { + Err(self) + } + } +} + +impl Weak { + /// Constructs a new `Weak`, without allocating any memory. + /// Calling [`upgrade`] on the return value always gives [`None`]. + /// + /// [`upgrade`]: struct.Weak.html#method.upgrade + /// [`None`]: ../../std/option/enum.Option.html#variant.None + /// + /// # Examples + /// + /// ``` + /// use std::sync::Weak; + /// + /// let empty: Weak = Weak::new(); + /// assert!(empty.upgrade().is_none()); + /// ``` + #[stable(feature = "downgraded_weak", since = "1.10.0")] + pub fn new() -> Weak { + unsafe { + Weak { + ptr: NonNull::new_unchecked(WEAK_EMPTY as *mut _), + } + } + } +} + +impl Weak { + /// Attempts to upgrade the `Weak` pointer to an [`Arc`], extending + /// the lifetime of the value if successful. + /// + /// Returns [`None`] if the value has since been dropped. + /// + /// [`Arc`]: struct.Arc.html + /// [`None`]: ../../std/option/enum.Option.html#variant.None + /// + /// # Examples + /// + /// ``` + /// use std::sync::Arc; + /// + /// let five = Arc::new(5); + /// + /// let weak_five = Arc::downgrade(&five); + /// + /// let strong_five: Option> = weak_five.upgrade(); + /// assert!(strong_five.is_some()); + /// + /// // Destroy all strong pointers. + /// drop(strong_five); + /// drop(five); + /// + /// assert!(weak_five.upgrade().is_none()); + /// ``` + #[stable(feature = "arc_weak", since = "1.4.0")] + pub fn upgrade(&self) -> Option> { + // We use a CAS loop to increment the strong count instead of a + // fetch_add because once the count hits 0 it must never be above 0. + let inner = if self.ptr.as_ptr() as *const u8 as usize == WEAK_EMPTY { + return None; + } else { + unsafe { self.ptr.as_ref() } + }; + + // Relaxed load because any write of 0 that we can observe + // leaves the field in a permanently zero state (so a + // "stale" read of 0 is fine), and any other value is + // confirmed via the CAS below. + let mut n = inner.strong.load(Relaxed); + + loop { + if n == 0 { + return None; + } + + // See comments in `Arc::clone` for why we do this (for `mem::forget`). + if n > MAX_REFCOUNT { + unsafe { + abort(); + } + } + + // Relaxed is valid for the same reason it is on Arc's Clone impl + match inner.strong.compare_exchange_weak(n, n + 1, Relaxed, Relaxed) { + Ok(_) => return Some(Arc { + // null checked above + ptr: self.ptr, + phantom: PhantomData, + }), + Err(old) => n = old, + } + } + } +} + +#[stable(feature = "arc_weak", since = "1.4.0")] +impl Clone for Weak { + /// Makes a clone of the `Weak` pointer that points to the same value. + /// + /// # Examples + /// + /// ``` + /// use std::sync::{Arc, Weak}; + /// + /// let weak_five = Arc::downgrade(&Arc::new(5)); + /// + /// Weak::clone(&weak_five); + /// ``` + #[inline] + fn clone(&self) -> Weak { + let inner = if self.ptr.as_ptr() as *const u8 as usize == WEAK_EMPTY { + return Weak { ptr: self.ptr }; + } else { + unsafe { self.ptr.as_ref() } + }; + // See comments in Arc::clone() for why this is relaxed. This can use a + // fetch_add (ignoring the lock) because the weak count is only locked + // where are *no other* weak pointers in existence. (So we can't be + // running this code in that case). + let old_size = inner.weak.fetch_add(1, Relaxed); + + // See comments in Arc::clone() for why we do this (for mem::forget). + if old_size > MAX_REFCOUNT { + unsafe { + abort(); + } + } + + return Weak { ptr: self.ptr }; + } +} + +#[stable(feature = "downgraded_weak", since = "1.10.0")] +impl Default for Weak { + /// Constructs a new `Weak`, without allocating memory. + /// Calling [`upgrade`] on the return value always gives [`None`]. + /// + /// [`upgrade`]: struct.Weak.html#method.upgrade + /// [`None`]: ../../std/option/enum.Option.html#variant.None + /// + /// # Examples + /// + /// ``` + /// use std::sync::Weak; + /// + /// let empty: Weak = Default::default(); + /// assert!(empty.upgrade().is_none()); + /// ``` + fn default() -> Weak { + Weak::new() + } +} + +#[stable(feature = "arc_weak", since = "1.4.0")] +impl Drop for Weak { + /// Drops the `Weak` pointer. + /// + /// # Examples + /// + /// ``` + /// use std::sync::{Arc, Weak}; + /// + /// struct Foo; + /// + /// impl Drop for Foo { + /// fn drop(&mut self) { + /// println!("dropped!"); + /// } + /// } + /// + /// let foo = Arc::new(Foo); + /// let weak_foo = Arc::downgrade(&foo); + /// let other_weak_foo = Weak::clone(&weak_foo); + /// + /// drop(weak_foo); // Doesn't print anything + /// drop(foo); // Prints "dropped!" + /// + /// assert!(other_weak_foo.upgrade().is_none()); + /// ``` + fn drop(&mut self) { + // If we find out that we were the last weak pointer, then its time to + // deallocate the data entirely. See the discussion in Arc::drop() about + // the memory orderings + // + // It's not necessary to check for the locked state here, because the + // weak count can only be locked if there was precisely one weak ref, + // meaning that drop could only subsequently run ON that remaining weak + // ref, which can only happen after the lock is released. + let inner = if self.ptr.as_ptr() as *const u8 as usize == WEAK_EMPTY { + return; + } else { + unsafe { self.ptr.as_ref() } + }; + + if inner.weak.fetch_sub(1, Release) == 1 { + atomic::fence(Acquire); + unsafe { + Global.dealloc(self.ptr.cast(), Layout::for_value(self.ptr.as_ref())) + } + } + } +} + +#[stable(feature = "rust1", since = "1.0.0")] +impl PartialEq for Arc { + /// Equality for two `Arc`s. + /// + /// Two `Arc`s are equal if their inner values are equal. + /// + /// # Examples + /// + /// ``` + /// use std::sync::Arc; + /// + /// let five = Arc::new(5); + /// + /// assert!(five == Arc::new(5)); + /// ``` + fn eq(&self, other: &Arc) -> bool { + *(*self) == *(*other) + } + + /// Inequality for two `Arc`s. + /// + /// Two `Arc`s are unequal if their inner values are unequal. + /// + /// # Examples + /// + /// ``` + /// use std::sync::Arc; + /// + /// let five = Arc::new(5); + /// + /// assert!(five != Arc::new(6)); + /// ``` + fn ne(&self, other: &Arc) -> bool { + *(*self) != *(*other) + } +} +#[stable(feature = "rust1", since = "1.0.0")] +impl PartialOrd for Arc { + /// Partial comparison for two `Arc`s. + /// + /// The two are compared by calling `partial_cmp()` on their inner values. + /// + /// # Examples + /// + /// ``` + /// use std::sync::Arc; + /// use std::cmp::Ordering; + /// + /// let five = Arc::new(5); + /// + /// assert_eq!(Some(Ordering::Less), five.partial_cmp(&Arc::new(6))); + /// ``` + fn partial_cmp(&self, other: &Arc) -> Option { + (**self).partial_cmp(&**other) + } + + /// Less-than comparison for two `Arc`s. + /// + /// The two are compared by calling `<` on their inner values. + /// + /// # Examples + /// + /// ``` + /// use std::sync::Arc; + /// + /// let five = Arc::new(5); + /// + /// assert!(five < Arc::new(6)); + /// ``` + fn lt(&self, other: &Arc) -> bool { + *(*self) < *(*other) + } + + /// 'Less than or equal to' comparison for two `Arc`s. + /// + /// The two are compared by calling `<=` on their inner values. + /// + /// # Examples + /// + /// ``` + /// use std::sync::Arc; + /// + /// let five = Arc::new(5); + /// + /// assert!(five <= Arc::new(5)); + /// ``` + fn le(&self, other: &Arc) -> bool { + *(*self) <= *(*other) + } + + /// Greater-than comparison for two `Arc`s. + /// + /// The two are compared by calling `>` on their inner values. + /// + /// # Examples + /// + /// ``` + /// use std::sync::Arc; + /// + /// let five = Arc::new(5); + /// + /// assert!(five > Arc::new(4)); + /// ``` + fn gt(&self, other: &Arc) -> bool { + *(*self) > *(*other) + } + + /// 'Greater than or equal to' comparison for two `Arc`s. + /// + /// The two are compared by calling `>=` on their inner values. + /// + /// # Examples + /// + /// ``` + /// use std::sync::Arc; + /// + /// let five = Arc::new(5); + /// + /// assert!(five >= Arc::new(5)); + /// ``` + fn ge(&self, other: &Arc) -> bool { + *(*self) >= *(*other) + } +} +#[stable(feature = "rust1", since = "1.0.0")] +impl Ord for Arc { + /// Comparison for two `Arc`s. + /// + /// The two are compared by calling `cmp()` on their inner values. + /// + /// # Examples + /// + /// ``` + /// use std::sync::Arc; + /// use std::cmp::Ordering; + /// + /// let five = Arc::new(5); + /// + /// assert_eq!(Ordering::Less, five.cmp(&Arc::new(6))); + /// ``` + fn cmp(&self, other: &Arc) -> Ordering { + (**self).cmp(&**other) + } +} +#[stable(feature = "rust1", since = "1.0.0")] +impl Eq for Arc {} + +#[stable(feature = "rust1", since = "1.0.0")] +impl fmt::Display for Arc { + fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { + fmt::Display::fmt(&**self, f) + } +} + +#[stable(feature = "rust1", since = "1.0.0")] +impl fmt::Debug for Arc { + fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { + fmt::Debug::fmt(&**self, f) + } +} + +#[stable(feature = "rust1", since = "1.0.0")] +impl fmt::Pointer for Arc { + fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { + fmt::Pointer::fmt(&(&**self as *const T), f) + } +} + +#[stable(feature = "rust1", since = "1.0.0")] +impl Default for Arc { + /// Creates a new `Arc`, with the `Default` value for `T`. + /// + /// # Examples + /// + /// ``` + /// use std::sync::Arc; + /// + /// let x: Arc = Default::default(); + /// assert_eq!(*x, 0); + /// ``` + fn default() -> Arc { + Arc::new(Default::default()) + } +} + +#[stable(feature = "rust1", since = "1.0.0")] +impl Hash for Arc { + fn hash(&self, state: &mut H) { + (**self).hash(state) + } +} + +#[stable(feature = "from_for_ptrs", since = "1.6.0")] +impl From for Arc { + fn from(t: T) -> Self { + Arc::new(t) + } +} + +#[stable(feature = "shared_from_slice", since = "1.21.0")] +impl<'a, T: Clone> From<&'a [T]> for Arc<[T]> { + #[inline] + fn from(v: &[T]) -> Arc<[T]> { + >::from_slice(v) + } +} + +#[stable(feature = "shared_from_slice", since = "1.21.0")] +impl<'a> From<&'a str> for Arc { + #[inline] + fn from(v: &str) -> Arc { + let arc = Arc::<[u8]>::from(v.as_bytes()); + unsafe { Arc::from_raw(Arc::into_raw(arc) as *const str) } + } +} + +#[stable(feature = "shared_from_slice", since = "1.21.0")] +impl From for Arc { + #[inline] + fn from(v: String) -> Arc { + Arc::from(&v[..]) + } +} + +#[stable(feature = "shared_from_slice", since = "1.21.0")] +impl From> for Arc { + #[inline] + fn from(v: Box) -> Arc { + Arc::from_box(v) + } +} + +#[stable(feature = "shared_from_slice", since = "1.21.0")] +impl From> for Arc<[T]> { + #[inline] + fn from(mut v: Vec) -> Arc<[T]> { + unsafe { + let arc = Arc::copy_from_slice(&v); + + // Allow the Vec to free its memory, but not destroy its contents + v.set_len(0); + + arc + } + } +} + +#[cfg(test)] +mod tests { + use std::boxed::Box; + use std::clone::Clone; + use std::sync::mpsc::channel; + use std::mem::drop; + use std::ops::Drop; + use std::option::Option; + use std::option::Option::{None, Some}; + use std::sync::atomic; + use std::sync::atomic::Ordering::{Acquire, SeqCst}; + use std::thread; + use std::sync::Mutex; + use std::convert::From; + + use super::{Arc, Weak}; + use vec::Vec; + + struct Canary(*mut atomic::AtomicUsize); + + impl Drop for Canary { + fn drop(&mut self) { + unsafe { + match *self { + Canary(c) => { + (*c).fetch_add(1, SeqCst); + } + } + } + } + } + + #[test] + #[cfg_attr(target_os = "emscripten", ignore)] + fn manually_share_arc() { + let v = vec![1, 2, 3, 4, 5, 6, 7, 8, 9, 10]; + let arc_v = Arc::new(v); + + let (tx, rx) = channel(); + + let _t = thread::spawn(move || { + let arc_v: Arc> = rx.recv().unwrap(); + assert_eq!((*arc_v)[3], 4); + }); + + tx.send(arc_v.clone()).unwrap(); + + assert_eq!((*arc_v)[2], 3); + assert_eq!((*arc_v)[4], 5); + } + + #[test] + fn test_arc_get_mut() { + let mut x = Arc::new(3); + *Arc::get_mut(&mut x).unwrap() = 4; + assert_eq!(*x, 4); + let y = x.clone(); + assert!(Arc::get_mut(&mut x).is_none()); + drop(y); + assert!(Arc::get_mut(&mut x).is_some()); + let _w = Arc::downgrade(&x); + assert!(Arc::get_mut(&mut x).is_none()); + } + + #[test] + fn try_unwrap() { + let x = Arc::new(3); + assert_eq!(Arc::try_unwrap(x), Ok(3)); + let x = Arc::new(4); + let _y = x.clone(); + assert_eq!(Arc::try_unwrap(x), Err(Arc::new(4))); + let x = Arc::new(5); + let _w = Arc::downgrade(&x); + assert_eq!(Arc::try_unwrap(x), Ok(5)); + } + + #[test] + fn into_from_raw() { + let x = Arc::new(box "hello"); + let y = x.clone(); + + let x_ptr = Arc::into_raw(x); + drop(y); + unsafe { + assert_eq!(**x_ptr, "hello"); + + let x = Arc::from_raw(x_ptr); + assert_eq!(**x, "hello"); + + assert_eq!(Arc::try_unwrap(x).map(|x| *x), Ok("hello")); + } + } + + #[test] + fn test_into_from_raw_unsized() { + use std::fmt::Display; + use std::string::ToString; + + let arc: Arc = Arc::from("foo"); + + let ptr = Arc::into_raw(arc.clone()); + let arc2 = unsafe { Arc::from_raw(ptr) }; + + assert_eq!(unsafe { &*ptr }, "foo"); + assert_eq!(arc, arc2); + + let arc: Arc = Arc::new(123); + + let ptr = Arc::into_raw(arc.clone()); + let arc2 = unsafe { Arc::from_raw(ptr) }; + + assert_eq!(unsafe { &*ptr }.to_string(), "123"); + assert_eq!(arc2.to_string(), "123"); + } + + #[test] + fn test_cowarc_clone_make_mut() { + let mut cow0 = Arc::new(75); + let mut cow1 = cow0.clone(); + let mut cow2 = cow1.clone(); + + assert!(75 == *Arc::make_mut(&mut cow0)); + assert!(75 == *Arc::make_mut(&mut cow1)); + assert!(75 == *Arc::make_mut(&mut cow2)); + + *Arc::make_mut(&mut cow0) += 1; + *Arc::make_mut(&mut cow1) += 2; + *Arc::make_mut(&mut cow2) += 3; + + assert!(76 == *cow0); + assert!(77 == *cow1); + assert!(78 == *cow2); + + // none should point to the same backing memory + assert!(*cow0 != *cow1); + assert!(*cow0 != *cow2); + assert!(*cow1 != *cow2); + } + + #[test] + fn test_cowarc_clone_unique2() { + let mut cow0 = Arc::new(75); + let cow1 = cow0.clone(); + let cow2 = cow1.clone(); + + assert!(75 == *cow0); + assert!(75 == *cow1); + assert!(75 == *cow2); + + *Arc::make_mut(&mut cow0) += 1; + assert!(76 == *cow0); + assert!(75 == *cow1); + assert!(75 == *cow2); + + // cow1 and cow2 should share the same contents + // cow0 should have a unique reference + assert!(*cow0 != *cow1); + assert!(*cow0 != *cow2); + assert!(*cow1 == *cow2); + } + + #[test] + fn test_cowarc_clone_weak() { + let mut cow0 = Arc::new(75); + let cow1_weak = Arc::downgrade(&cow0); + + assert!(75 == *cow0); + assert!(75 == *cow1_weak.upgrade().unwrap()); + + *Arc::make_mut(&mut cow0) += 1; + + assert!(76 == *cow0); + assert!(cow1_weak.upgrade().is_none()); + } + + #[test] + fn test_live() { + let x = Arc::new(5); + let y = Arc::downgrade(&x); + assert!(y.upgrade().is_some()); + } + + #[test] + fn test_dead() { + let x = Arc::new(5); + let y = Arc::downgrade(&x); + drop(x); + assert!(y.upgrade().is_none()); + } + + #[test] + fn weak_self_cyclic() { + struct Cycle { + x: Mutex>>, + } + + let a = Arc::new(Cycle { x: Mutex::new(None) }); + let b = Arc::downgrade(&a.clone()); + *a.x.lock().unwrap() = Some(b); + + // hopefully we don't double-free (or leak)... + } + + #[test] + fn drop_arc() { + let mut canary = atomic::AtomicUsize::new(0); + let x = Arc::new(Canary(&mut canary as *mut atomic::AtomicUsize)); + drop(x); + assert!(canary.load(Acquire) == 1); + } + + #[test] + fn drop_arc_weak() { + let mut canary = atomic::AtomicUsize::new(0); + let arc = Arc::new(Canary(&mut canary as *mut atomic::AtomicUsize)); + let arc_weak = Arc::downgrade(&arc); + assert!(canary.load(Acquire) == 0); + drop(arc); + assert!(canary.load(Acquire) == 1); + drop(arc_weak); + } + + #[test] + fn test_strong_count() { + let a = Arc::new(0); + assert!(Arc::strong_count(&a) == 1); + let w = Arc::downgrade(&a); + assert!(Arc::strong_count(&a) == 1); + let b = w.upgrade().expect(""); + assert!(Arc::strong_count(&b) == 2); + assert!(Arc::strong_count(&a) == 2); + drop(w); + drop(a); + assert!(Arc::strong_count(&b) == 1); + let c = b.clone(); + assert!(Arc::strong_count(&b) == 2); + assert!(Arc::strong_count(&c) == 2); + } + + #[test] + fn test_weak_count() { + let a = Arc::new(0); + assert!(Arc::strong_count(&a) == 1); + assert!(Arc::weak_count(&a) == 0); + let w = Arc::downgrade(&a); + assert!(Arc::strong_count(&a) == 1); + assert!(Arc::weak_count(&a) == 1); + let x = w.clone(); + assert!(Arc::weak_count(&a) == 2); + drop(w); + drop(x); + assert!(Arc::strong_count(&a) == 1); + assert!(Arc::weak_count(&a) == 0); + let c = a.clone(); + assert!(Arc::strong_count(&a) == 2); + assert!(Arc::weak_count(&a) == 0); + let d = Arc::downgrade(&c); + assert!(Arc::weak_count(&c) == 1); + assert!(Arc::strong_count(&c) == 2); + + drop(a); + drop(c); + drop(d); + } + + #[test] + fn show_arc() { + let a = Arc::new(5); + assert_eq!(format!("{:?}", a), "5"); + } + + // Make sure deriving works with Arc + #[derive(Eq, Ord, PartialEq, PartialOrd, Clone, Debug, Default)] + struct Foo { + inner: Arc, + } + + #[test] + fn test_unsized() { + let x: Arc<[i32]> = Arc::new([1, 2, 3]); + assert_eq!(format!("{:?}", x), "[1, 2, 3]"); + let y = Arc::downgrade(&x.clone()); + drop(x); + assert!(y.upgrade().is_none()); + } + + #[test] + fn test_from_owned() { + let foo = 123; + let foo_arc = Arc::from(foo); + assert!(123 == *foo_arc); + } + + #[test] + fn test_new_weak() { + let foo: Weak = Weak::new(); + assert!(foo.upgrade().is_none()); + } + + #[test] + fn test_ptr_eq() { + let five = Arc::new(5); + let same_five = five.clone(); + let other_five = Arc::new(5); + + assert!(Arc::ptr_eq(&five, &same_five)); + assert!(!Arc::ptr_eq(&five, &other_five)); + } + + #[test] + #[cfg_attr(target_os = "emscripten", ignore)] + fn test_weak_count_locked() { + let mut a = Arc::new(atomic::AtomicBool::new(false)); + let a2 = a.clone(); + let t = thread::spawn(move || { + for _i in 0..1000000 { + Arc::get_mut(&mut a); + } + a.store(true, SeqCst); + }); + + while !a2.load(SeqCst) { + let n = Arc::weak_count(&a2); + assert!(n < 2, "bad weak count: {}", n); + } + t.join().unwrap(); + } + + #[test] + fn test_from_str() { + let r: Arc = Arc::from("foo"); + + assert_eq!(&r[..], "foo"); + } + + #[test] + fn test_copy_from_slice() { + let s: &[u32] = &[1, 2, 3]; + let r: Arc<[u32]> = Arc::from(s); + + assert_eq!(&r[..], [1, 2, 3]); + } + + #[test] + fn test_clone_from_slice() { + #[derive(Clone, Debug, Eq, PartialEq)] + struct X(u32); + + let s: &[X] = &[X(1), X(2), X(3)]; + let r: Arc<[X]> = Arc::from(s); + + assert_eq!(&r[..], s); + } + + #[test] + #[should_panic] + fn test_clone_from_slice_panic() { + use std::string::{String, ToString}; + + struct Fail(u32, String); + + impl Clone for Fail { + fn clone(&self) -> Fail { + if self.0 == 2 { + panic!(); + } + Fail(self.0, self.1.clone()) + } + } + + let s: &[Fail] = &[ + Fail(0, "foo".to_string()), + Fail(1, "bar".to_string()), + Fail(2, "baz".to_string()), + ]; + + // Should panic, but not cause memory corruption + let _r: Arc<[Fail]> = Arc::from(s); + } + + #[test] + fn test_from_box() { + let b: Box = box 123; + let r: Arc = Arc::from(b); + + assert_eq!(*r, 123); + } + + #[test] + fn test_from_box_str() { + use std::string::String; + + let s = String::from("foo").into_boxed_str(); + let r: Arc = Arc::from(s); + + assert_eq!(&r[..], "foo"); + } + + #[test] + fn test_from_box_slice() { + let s = vec![1, 2, 3].into_boxed_slice(); + let r: Arc<[u32]> = Arc::from(s); + + assert_eq!(&r[..], [1, 2, 3]); + } + + #[test] + fn test_from_box_trait() { + use std::fmt::Display; + use std::string::ToString; + + let b: Box = box 123; + let r: Arc = Arc::from(b); + + assert_eq!(r.to_string(), "123"); + } + + #[test] + fn test_from_box_trait_zero_sized() { + use std::fmt::Debug; + + let b: Box = box (); + let r: Arc = Arc::from(b); + + assert_eq!(format!("{:?}", r), "()"); + } + + #[test] + fn test_from_vec() { + let v = vec![1, 2, 3]; + let r: Arc<[u32]> = Arc::from(v); + + assert_eq!(&r[..], [1, 2, 3]); + } + + #[test] + fn test_downcast() { + use std::any::Any; + + let r1: Arc = Arc::new(i32::max_value()); + let r2: Arc = Arc::new("abc"); + + assert!(r1.clone().downcast::().is_err()); + + let r1i32 = r1.downcast::(); + assert!(r1i32.is_ok()); + assert_eq!(r1i32.unwrap(), Arc::new(i32::max_value())); + + assert!(r2.clone().downcast::().is_err()); + + let r2str = r2.downcast::<&'static str>(); + assert!(r2str.is_ok()); + assert_eq!(r2str.unwrap(), Arc::new("abc")); + } +} + +#[stable(feature = "rust1", since = "1.0.0")] +impl borrow::Borrow for Arc { + fn borrow(&self) -> &T { + &**self + } +} + +#[stable(since = "1.5.0", feature = "smart_ptr_as_ref")] +impl AsRef for Arc { + fn as_ref(&self) -> &T { + &**self + } +} diff --git a/src/liballoc/task.rs b/src/liballoc/task.rs index 7b1947b56b8..f14fe3a20da 100644 --- a/src/liballoc/task.rs +++ b/src/liballoc/task.rs @@ -18,10 +18,10 @@ pub use self::if_arc::*; #[cfg(target_has_atomic = "ptr")] mod if_arc { use super::*; - use arc::Arc; use core::marker::PhantomData; use core::mem; use core::ptr::{self, NonNull}; + use sync::Arc; /// A way of waking up a specific task. /// diff --git a/src/libstd/sync/mod.rs b/src/libstd/sync/mod.rs index 642b284c6c7..e12ef8d9eda 100644 --- a/src/libstd/sync/mod.rs +++ b/src/libstd/sync/mod.rs @@ -18,7 +18,7 @@ #![stable(feature = "rust1", since = "1.0.0")] #[stable(feature = "rust1", since = "1.0.0")] -pub use alloc_crate::arc::{Arc, Weak}; +pub use alloc_crate::sync::{Arc, Weak}; #[stable(feature = "rust1", since = "1.0.0")] pub use core::sync::atomic; -- cgit 1.4.1-3-g733a5 From 560d8079ec26f2a45ecb80e95d24917025e02104 Mon Sep 17 00:00:00 2001 From: ljedrz Date: Tue, 10 Jul 2018 20:35:36 +0200 Subject: Deny bare trait objects in `src/libstd`. --- src/libstd/error.rs | 86 ++++++++++++++++++------------------ src/libstd/ffi/c_str.rs | 2 +- src/libstd/io/error.rs | 14 +++--- src/libstd/io/mod.rs | 4 +- src/libstd/io/stdio.rs | 8 ++-- src/libstd/lib.rs | 1 + src/libstd/net/parser.rs | 2 +- src/libstd/panic.rs | 2 +- src/libstd/panicking.rs | 36 +++++++-------- src/libstd/process.rs | 4 +- src/libstd/rt.rs | 2 +- src/libstd/sync/mpsc/mod.rs | 10 ++--- src/libstd/sync/mpsc/select.rs | 2 +- src/libstd/sync/once.rs | 2 +- src/libstd/sys/windows/thread.rs | 2 +- src/libstd/sys_common/at_exit_imp.rs | 4 +- src/libstd/sys_common/backtrace.rs | 10 ++--- src/libstd/sys_common/poison.rs | 2 +- src/libstd/sys_common/thread.rs | 2 +- src/libstd/thread/mod.rs | 2 +- 20 files changed, 99 insertions(+), 98 deletions(-) (limited to 'src/libstd/sync') diff --git a/src/libstd/error.rs b/src/libstd/error.rs index 1958915602f..8d715ac0ec3 100644 --- a/src/libstd/error.rs +++ b/src/libstd/error.rs @@ -138,7 +138,7 @@ pub trait Error: Debug + Display { /// } /// ``` #[stable(feature = "rust1", since = "1.0.0")] - fn cause(&self) -> Option<&Error> { None } + fn cause(&self) -> Option<&dyn Error> { None } /// Get the `TypeId` of `self` #[doc(hidden)] @@ -151,22 +151,22 @@ pub trait Error: Debug + Display { } #[stable(feature = "rust1", since = "1.0.0")] -impl<'a, E: Error + 'a> From for Box { - fn from(err: E) -> Box { +impl<'a, E: Error + 'a> From for Box { + fn from(err: E) -> Box { Box::new(err) } } #[stable(feature = "rust1", since = "1.0.0")] -impl<'a, E: Error + Send + Sync + 'a> From for Box { - fn from(err: E) -> Box { +impl<'a, E: Error + Send + Sync + 'a> From for Box { + fn from(err: E) -> Box { Box::new(err) } } #[stable(feature = "rust1", since = "1.0.0")] -impl From for Box { - fn from(err: String) -> Box { +impl From for Box { + fn from(err: String) -> Box { #[derive(Debug)] struct StringError(String); @@ -185,38 +185,38 @@ impl From for Box { } #[stable(feature = "string_box_error", since = "1.6.0")] -impl From for Box { - fn from(str_err: String) -> Box { - let err1: Box = From::from(str_err); - let err2: Box = err1; +impl From for Box { + fn from(str_err: String) -> Box { + let err1: Box = From::from(str_err); + let err2: Box = err1; err2 } } #[stable(feature = "rust1", since = "1.0.0")] -impl<'a, 'b> From<&'b str> for Box { - fn from(err: &'b str) -> Box { +impl<'a, 'b> From<&'b str> for Box { + fn from(err: &'b str) -> Box { From::from(String::from(err)) } } #[stable(feature = "string_box_error", since = "1.6.0")] -impl<'a> From<&'a str> for Box { - fn from(err: &'a str) -> Box { +impl<'a> From<&'a str> for Box { + fn from(err: &'a str) -> Box { From::from(String::from(err)) } } #[stable(feature = "cow_box_error", since = "1.22.0")] -impl<'a, 'b> From> for Box { - fn from(err: Cow<'b, str>) -> Box { +impl<'a, 'b> From> for Box { + fn from(err: Cow<'b, str>) -> Box { From::from(String::from(err)) } } #[stable(feature = "cow_box_error", since = "1.22.0")] -impl<'a> From> for Box { - fn from(err: Cow<'a, str>) -> Box { +impl<'a> From> for Box { + fn from(err: Cow<'a, str>) -> Box { From::from(String::from(err)) } } @@ -327,7 +327,7 @@ impl Error for Box { Error::description(&**self) } - fn cause(&self) -> Option<&Error> { + fn cause(&self) -> Option<&dyn Error> { Error::cause(&**self) } } @@ -368,7 +368,7 @@ impl Error for char::ParseCharError { } // copied from any.rs -impl Error + 'static { +impl dyn Error + 'static { /// Returns true if the boxed type is the same as `T` #[stable(feature = "error_downcast", since = "1.3.0")] #[inline] @@ -390,7 +390,7 @@ impl Error + 'static { pub fn downcast_ref(&self) -> Option<&T> { if self.is::() { unsafe { - Some(&*(self as *const Error as *const T)) + Some(&*(self as *const dyn Error as *const T)) } } else { None @@ -404,7 +404,7 @@ impl Error + 'static { pub fn downcast_mut(&mut self) -> Option<&mut T> { if self.is::() { unsafe { - Some(&mut *(self as *mut Error as *mut T)) + Some(&mut *(self as *mut dyn Error as *mut T)) } } else { None @@ -412,60 +412,60 @@ impl Error + 'static { } } -impl Error + 'static + Send { +impl dyn Error + 'static + Send { /// Forwards to the method defined on the type `Any`. #[stable(feature = "error_downcast", since = "1.3.0")] #[inline] pub fn is(&self) -> bool { - ::is::(self) + ::is::(self) } /// Forwards to the method defined on the type `Any`. #[stable(feature = "error_downcast", since = "1.3.0")] #[inline] pub fn downcast_ref(&self) -> Option<&T> { - ::downcast_ref::(self) + ::downcast_ref::(self) } /// Forwards to the method defined on the type `Any`. #[stable(feature = "error_downcast", since = "1.3.0")] #[inline] pub fn downcast_mut(&mut self) -> Option<&mut T> { - ::downcast_mut::(self) + ::downcast_mut::(self) } } -impl Error + 'static + Send + Sync { +impl dyn Error + 'static + Send + Sync { /// Forwards to the method defined on the type `Any`. #[stable(feature = "error_downcast", since = "1.3.0")] #[inline] pub fn is(&self) -> bool { - ::is::(self) + ::is::(self) } /// Forwards to the method defined on the type `Any`. #[stable(feature = "error_downcast", since = "1.3.0")] #[inline] pub fn downcast_ref(&self) -> Option<&T> { - ::downcast_ref::(self) + ::downcast_ref::(self) } /// Forwards to the method defined on the type `Any`. #[stable(feature = "error_downcast", since = "1.3.0")] #[inline] pub fn downcast_mut(&mut self) -> Option<&mut T> { - ::downcast_mut::(self) + ::downcast_mut::(self) } } -impl Error { +impl dyn Error { #[inline] #[stable(feature = "error_downcast", since = "1.3.0")] /// Attempt to downcast the box to a concrete type. - pub fn downcast(self: Box) -> Result, Box> { + pub fn downcast(self: Box) -> Result, Box> { if self.is::() { unsafe { - let raw: *mut Error = Box::into_raw(self); + let raw: *mut dyn Error = Box::into_raw(self); Ok(Box::from_raw(raw as *mut T)) } } else { @@ -474,30 +474,30 @@ impl Error { } } -impl Error + Send { +impl dyn Error + Send { #[inline] #[stable(feature = "error_downcast", since = "1.3.0")] /// Attempt to downcast the box to a concrete type. pub fn downcast(self: Box) - -> Result, Box> { - let err: Box = self; - ::downcast(err).map_err(|s| unsafe { + -> Result, Box> { + let err: Box = self; + ::downcast(err).map_err(|s| unsafe { // reapply the Send marker - transmute::, Box>(s) + transmute::, Box>(s) }) } } -impl Error + Send + Sync { +impl dyn Error + Send + Sync { #[inline] #[stable(feature = "error_downcast", since = "1.3.0")] /// Attempt to downcast the box to a concrete type. pub fn downcast(self: Box) -> Result, Box> { - let err: Box = self; - ::downcast(err).map_err(|s| unsafe { + let err: Box = self; + ::downcast(err).map_err(|s| unsafe { // reapply the Send+Sync marker - transmute::, Box>(s) + transmute::, Box>(s) }) } } diff --git a/src/libstd/ffi/c_str.rs b/src/libstd/ffi/c_str.rs index 6513d11dd51..03e0d0aa6dd 100644 --- a/src/libstd/ffi/c_str.rs +++ b/src/libstd/ffi/c_str.rs @@ -883,7 +883,7 @@ impl Error for IntoStringError { "C string contained non-utf8 bytes" } - fn cause(&self) -> Option<&Error> { + fn cause(&self) -> Option<&dyn Error> { Some(&self.error) } } diff --git a/src/libstd/io/error.rs b/src/libstd/io/error.rs index bdd675e6e2b..02a3ce8b9c4 100644 --- a/src/libstd/io/error.rs +++ b/src/libstd/io/error.rs @@ -83,7 +83,7 @@ enum Repr { #[derive(Debug)] struct Custom { kind: ErrorKind, - error: Box, + error: Box, } /// A list specifying general categories of I/O error. @@ -250,12 +250,12 @@ impl Error { /// ``` #[stable(feature = "rust1", since = "1.0.0")] pub fn new(kind: ErrorKind, error: E) -> Error - where E: Into> + where E: Into> { Self::_new(kind, error.into()) } - fn _new(kind: ErrorKind, error: Box) -> Error { + fn _new(kind: ErrorKind, error: Box) -> Error { Error { repr: Repr::Custom(Box::new(Custom { kind, @@ -373,7 +373,7 @@ impl Error { /// } /// ``` #[stable(feature = "io_error_inner", since = "1.3.0")] - pub fn get_ref(&self) -> Option<&(error::Error+Send+Sync+'static)> { + pub fn get_ref(&self) -> Option<&(dyn error::Error+Send+Sync+'static)> { match self.repr { Repr::Os(..) => None, Repr::Simple(..) => None, @@ -444,7 +444,7 @@ impl Error { /// } /// ``` #[stable(feature = "io_error_inner", since = "1.3.0")] - pub fn get_mut(&mut self) -> Option<&mut (error::Error+Send+Sync+'static)> { + pub fn get_mut(&mut self) -> Option<&mut (dyn error::Error+Send+Sync+'static)> { match self.repr { Repr::Os(..) => None, Repr::Simple(..) => None, @@ -478,7 +478,7 @@ impl Error { /// } /// ``` #[stable(feature = "io_error_inner", since = "1.3.0")] - pub fn into_inner(self) -> Option> { + pub fn into_inner(self) -> Option> { match self.repr { Repr::Os(..) => None, Repr::Simple(..) => None, @@ -551,7 +551,7 @@ impl error::Error for Error { } } - fn cause(&self) -> Option<&error::Error> { + fn cause(&self) -> Option<&dyn error::Error> { match self.repr { Repr::Os(..) => None, Repr::Simple(..) => None, diff --git a/src/libstd/io/mod.rs b/src/libstd/io/mod.rs index 2b4644bd013..85304874848 100644 --- a/src/libstd/io/mod.rs +++ b/src/libstd/io/mod.rs @@ -1972,7 +1972,7 @@ impl BufRead for Take { } } -fn read_one_byte(reader: &mut Read) -> Option> { +fn read_one_byte(reader: &mut dyn Read) -> Option> { let mut buf = [0]; loop { return match reader.read(&mut buf) { @@ -2081,7 +2081,7 @@ impl std_error::Error for CharsError { CharsError::Other(ref e) => std_error::Error::description(e), } } - fn cause(&self) -> Option<&std_error::Error> { + fn cause(&self) -> Option<&dyn std_error::Error> { match *self { CharsError::NotUtf8 => None, CharsError::Other(ref e) => e.cause(), diff --git a/src/libstd/io/stdio.rs b/src/libstd/io/stdio.rs index fce85a200ba..fffe8fc559b 100644 --- a/src/libstd/io/stdio.rs +++ b/src/libstd/io/stdio.rs @@ -21,7 +21,7 @@ use thread::LocalKey; /// Stdout used by print! and println! macros thread_local! { - static LOCAL_STDOUT: RefCell>> = { + static LOCAL_STDOUT: RefCell>> = { RefCell::new(None) } } @@ -624,7 +624,7 @@ impl<'a> fmt::Debug for StderrLock<'a> { with a more general mechanism", issue = "0")] #[doc(hidden)] -pub fn set_panic(sink: Option>) -> Option> { +pub fn set_panic(sink: Option>) -> Option> { use panicking::LOCAL_STDERR; use mem; LOCAL_STDERR.with(move |slot| { @@ -648,7 +648,7 @@ pub fn set_panic(sink: Option>) -> Option> { with a more general mechanism", issue = "0")] #[doc(hidden)] -pub fn set_print(sink: Option>) -> Option> { +pub fn set_print(sink: Option>) -> Option> { use mem; LOCAL_STDOUT.with(move |slot| { mem::replace(&mut *slot.borrow_mut(), sink) @@ -670,7 +670,7 @@ pub fn set_print(sink: Option>) -> Option> { /// However, if the actual I/O causes an error, this function does panic. fn print_to( args: fmt::Arguments, - local_s: &'static LocalKey>>>, + local_s: &'static LocalKey>>>, global_s: fn() -> T, label: &str, ) diff --git a/src/libstd/lib.rs b/src/libstd/lib.rs index d73cb1f8349..006922383cf 100644 --- a/src/libstd/lib.rs +++ b/src/libstd/lib.rs @@ -221,6 +221,7 @@ // Don't link to std. We are std. #![no_std] +#![deny(bare_trait_objects)] #![deny(missing_docs)] #![deny(missing_debug_implementations)] diff --git a/src/libstd/net/parser.rs b/src/libstd/net/parser.rs index ae5037cc44e..234c5618a06 100644 --- a/src/libstd/net/parser.rs +++ b/src/libstd/net/parser.rs @@ -61,7 +61,7 @@ impl<'a> Parser<'a> { } // Return result of first successful parser - fn read_or(&mut self, parsers: &mut [Box Option + 'static>]) + fn read_or(&mut self, parsers: &mut [Box Option + 'static>]) -> Option { for pf in parsers { if let Some(r) = self.read_atomically(|p: &mut Parser| pf(p)) { diff --git a/src/libstd/panic.rs b/src/libstd/panic.rs index 451420ae88a..b8c1c4f9e68 100644 --- a/src/libstd/panic.rs +++ b/src/libstd/panic.rs @@ -421,6 +421,6 @@ pub fn catch_unwind R + UnwindSafe, R>(f: F) -> Result { /// } /// ``` #[stable(feature = "resume_unwind", since = "1.9.0")] -pub fn resume_unwind(payload: Box) -> ! { +pub fn resume_unwind(payload: Box) -> ! { panicking::update_count_then_panic(payload) } diff --git a/src/libstd/panicking.rs b/src/libstd/panicking.rs index 46b6cf60705..283fd36af41 100644 --- a/src/libstd/panicking.rs +++ b/src/libstd/panicking.rs @@ -36,7 +36,7 @@ use sys_common::util; use thread; thread_local! { - pub static LOCAL_STDERR: RefCell>> = { + pub static LOCAL_STDERR: RefCell>> = { RefCell::new(None) } } @@ -64,7 +64,7 @@ extern { #[derive(Copy, Clone)] enum Hook { Default, - Custom(*mut (Fn(&PanicInfo) + 'static + Sync + Send)), + Custom(*mut (dyn Fn(&PanicInfo) + 'static + Sync + Send)), } static HOOK_LOCK: RWLock = RWLock::new(); @@ -104,7 +104,7 @@ static mut HOOK: Hook = Hook::Default; /// panic!("Normal panic"); /// ``` #[stable(feature = "panic_hooks", since = "1.10.0")] -pub fn set_hook(hook: Box) { +pub fn set_hook(hook: Box) { if thread::panicking() { panic!("cannot modify the panic hook from a panicking thread"); } @@ -149,7 +149,7 @@ pub fn set_hook(hook: Box) { /// panic!("Normal panic"); /// ``` #[stable(feature = "panic_hooks", since = "1.10.0")] -pub fn take_hook() -> Box { +pub fn take_hook() -> Box { if thread::panicking() { panic!("cannot modify the panic hook from a panicking thread"); } @@ -197,7 +197,7 @@ fn default_hook(info: &PanicInfo) { let thread = thread_info::current_thread(); let name = thread.as_ref().and_then(|t| t.name()).unwrap_or(""); - let write = |err: &mut ::io::Write| { + let write = |err: &mut dyn (::io::Write)| { let _ = writeln!(err, "thread '{}' panicked at '{}', {}", name, msg, location); @@ -248,7 +248,7 @@ pub fn update_panic_count(amt: isize) -> usize { pub use realstd::rt::update_panic_count; /// Invoke a closure, capturing the cause of an unwinding panic if one occurs. -pub unsafe fn try R>(f: F) -> Result> { +pub unsafe fn try R>(f: F) -> Result> { #[allow(unions_with_drop_fields)] union Data { f: F, @@ -369,12 +369,12 @@ fn continue_panic_fmt(info: &PanicInfo) -> ! { } unsafe impl<'a> BoxMeUp for PanicPayload<'a> { - fn box_me_up(&mut self) -> *mut (Any + Send) { + fn box_me_up(&mut self) -> *mut (dyn Any + Send) { let contents = mem::replace(self.fill(), String::new()); Box::into_raw(Box::new(contents)) } - fn get(&mut self) -> &(Any + Send) { + fn get(&mut self) -> &(dyn Any + Send) { self.fill() } } @@ -419,15 +419,15 @@ pub fn begin_panic(msg: M, file_line_col: &(&'static str, u32, u3 } unsafe impl BoxMeUp for PanicPayload { - fn box_me_up(&mut self) -> *mut (Any + Send) { + fn box_me_up(&mut self) -> *mut (dyn Any + Send) { let data = match self.inner.take() { - Some(a) => Box::new(a) as Box, + Some(a) => Box::new(a) as Box, None => Box::new(()), }; Box::into_raw(data) } - fn get(&mut self) -> &(Any + Send) { + fn get(&mut self) -> &(dyn Any + Send) { match self.inner { Some(ref a) => a, None => &(), @@ -441,7 +441,7 @@ pub fn begin_panic(msg: M, file_line_col: &(&'static str, u32, u3 /// Executes the primary logic for a panic, including checking for recursive /// panics, panic hooks, and finally dispatching to the panic runtime to either /// abort or unwind. -fn rust_panic_with_hook(payload: &mut BoxMeUp, +fn rust_panic_with_hook(payload: &mut dyn BoxMeUp, message: Option<&fmt::Arguments>, file_line_col: &(&str, u32, u32)) -> ! { let (file, line, col) = *file_line_col; @@ -496,17 +496,17 @@ fn rust_panic_with_hook(payload: &mut BoxMeUp, } /// Shim around rust_panic. Called by resume_unwind. -pub fn update_count_then_panic(msg: Box) -> ! { +pub fn update_count_then_panic(msg: Box) -> ! { update_panic_count(1); - struct RewrapBox(Box); + struct RewrapBox(Box); unsafe impl BoxMeUp for RewrapBox { - fn box_me_up(&mut self) -> *mut (Any + Send) { + fn box_me_up(&mut self) -> *mut (dyn Any + Send) { Box::into_raw(mem::replace(&mut self.0, Box::new(()))) } - fn get(&mut self) -> &(Any + Send) { + fn get(&mut self) -> &(dyn Any + Send) { &*self.0 } } @@ -517,9 +517,9 @@ pub fn update_count_then_panic(msg: Box) -> ! { /// A private no-mangle function on which to slap yer breakpoints. #[no_mangle] #[allow(private_no_mangle_fns)] // yes we get it, but we like breakpoints -pub fn rust_panic(mut msg: &mut BoxMeUp) -> ! { +pub fn rust_panic(mut msg: &mut dyn BoxMeUp) -> ! { let code = unsafe { - let obj = &mut msg as *mut &mut BoxMeUp; + let obj = &mut msg as *mut &mut dyn BoxMeUp; __rust_start_panic(obj as usize) }; rtabort!("failed to initiate panic, error {}", code) diff --git a/src/libstd/process.rs b/src/libstd/process.rs index 00051d4487a..39692836866 100644 --- a/src/libstd/process.rs +++ b/src/libstd/process.rs @@ -813,13 +813,13 @@ impl fmt::Debug for Output { fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result { let stdout_utf8 = str::from_utf8(&self.stdout); - let stdout_debug: &fmt::Debug = match stdout_utf8 { + let stdout_debug: &dyn fmt::Debug = match stdout_utf8 { Ok(ref str) => str, Err(_) => &self.stdout }; let stderr_utf8 = str::from_utf8(&self.stderr); - let stderr_debug: &fmt::Debug = match stderr_utf8 { + let stderr_debug: &dyn fmt::Debug = match stderr_utf8 { Ok(ref str) => str, Err(_) => &self.stderr }; diff --git a/src/libstd/rt.rs b/src/libstd/rt.rs index 8f945470b7e..9e957bd87d7 100644 --- a/src/libstd/rt.rs +++ b/src/libstd/rt.rs @@ -29,7 +29,7 @@ pub use panicking::{begin_panic, begin_panic_fmt, update_panic_count}; // To reduce the generated code of the new `lang_start`, this function is doing // the real work. #[cfg(not(test))] -fn lang_start_internal(main: &(Fn() -> i32 + Sync + ::panic::RefUnwindSafe), +fn lang_start_internal(main: &(dyn Fn() -> i32 + Sync + ::panic::RefUnwindSafe), argc: isize, argv: *const *const u8) -> isize { use panic; use sys; diff --git a/src/libstd/sync/mpsc/mod.rs b/src/libstd/sync/mpsc/mod.rs index 2dd3aebe610..1dc0b1c0042 100644 --- a/src/libstd/sync/mpsc/mod.rs +++ b/src/libstd/sync/mpsc/mod.rs @@ -1638,7 +1638,7 @@ impl error::Error for SendError { "sending on a closed channel" } - fn cause(&self) -> Option<&error::Error> { + fn cause(&self) -> Option<&dyn error::Error> { None } } @@ -1681,7 +1681,7 @@ impl error::Error for TrySendError { } } - fn cause(&self) -> Option<&error::Error> { + fn cause(&self) -> Option<&dyn error::Error> { None } } @@ -1709,7 +1709,7 @@ impl error::Error for RecvError { "receiving on a closed channel" } - fn cause(&self) -> Option<&error::Error> { + fn cause(&self) -> Option<&dyn error::Error> { None } } @@ -1742,7 +1742,7 @@ impl error::Error for TryRecvError { } } - fn cause(&self) -> Option<&error::Error> { + fn cause(&self) -> Option<&dyn error::Error> { None } } @@ -1783,7 +1783,7 @@ impl error::Error for RecvTimeoutError { } } - fn cause(&self) -> Option<&error::Error> { + fn cause(&self) -> Option<&dyn error::Error> { None } } diff --git a/src/libstd/sync/mpsc/select.rs b/src/libstd/sync/mpsc/select.rs index 9310dad9172..a7a284cfb79 100644 --- a/src/libstd/sync/mpsc/select.rs +++ b/src/libstd/sync/mpsc/select.rs @@ -93,7 +93,7 @@ pub struct Handle<'rx, T:Send+'rx> { next: *mut Handle<'static, ()>, prev: *mut Handle<'static, ()>, added: bool, - packet: &'rx (Packet+'rx), + packet: &'rx (dyn Packet+'rx), // due to our fun transmutes, we be sure to place this at the end. (nothing // previous relies on T) diff --git a/src/libstd/sync/once.rs b/src/libstd/sync/once.rs index 7eb7be23128..1c63f99753a 100644 --- a/src/libstd/sync/once.rs +++ b/src/libstd/sync/once.rs @@ -301,7 +301,7 @@ impl Once { #[cold] fn call_inner(&'static self, ignore_poisoning: bool, - init: &mut FnMut(bool)) { + init: &mut dyn FnMut(bool)) { let mut state = self.state.load(Ordering::SeqCst); 'outer: loop { diff --git a/src/libstd/sys/windows/thread.rs b/src/libstd/sys/windows/thread.rs index b6f63303dc2..44ec872b244 100644 --- a/src/libstd/sys/windows/thread.rs +++ b/src/libstd/sys/windows/thread.rs @@ -28,7 +28,7 @@ pub struct Thread { } impl Thread { - pub unsafe fn new<'a>(stack: usize, p: Box) + pub unsafe fn new<'a>(stack: usize, p: Box) -> io::Result { let p = box p; diff --git a/src/libstd/sys_common/at_exit_imp.rs b/src/libstd/sys_common/at_exit_imp.rs index d268d9ad6f9..b28a4d2f8be 100644 --- a/src/libstd/sys_common/at_exit_imp.rs +++ b/src/libstd/sys_common/at_exit_imp.rs @@ -17,7 +17,7 @@ use ptr; use mem; use sys_common::mutex::Mutex; -type Queue = Vec>; +type Queue = Vec>; // NB these are specifically not types from `std::sync` as they currently rely // on poisoning and this module needs to operate at a lower level than requiring @@ -68,7 +68,7 @@ pub fn cleanup() { } } -pub fn push(f: Box) -> bool { +pub fn push(f: Box) -> bool { unsafe { let _guard = LOCK.lock(); if init() { diff --git a/src/libstd/sys_common/backtrace.rs b/src/libstd/sys_common/backtrace.rs index 61d7ed463dd..6184ba4ded6 100644 --- a/src/libstd/sys_common/backtrace.rs +++ b/src/libstd/sys_common/backtrace.rs @@ -49,7 +49,7 @@ pub struct Frame { const MAX_NB_FRAMES: usize = 100; /// Prints the current backtrace. -pub fn print(w: &mut Write, format: PrintFormat) -> io::Result<()> { +pub fn print(w: &mut dyn Write, format: PrintFormat) -> io::Result<()> { static LOCK: Mutex = Mutex::new(); // Use a lock to prevent mixed output in multithreading context. @@ -62,7 +62,7 @@ pub fn print(w: &mut Write, format: PrintFormat) -> io::Result<()> { } } -fn _print(w: &mut Write, format: PrintFormat) -> io::Result<()> { +fn _print(w: &mut dyn Write, format: PrintFormat) -> io::Result<()> { let mut frames = [Frame { exact_position: ptr::null(), symbol_addr: ptr::null(), @@ -177,7 +177,7 @@ pub fn log_enabled() -> Option { /// /// These output functions should now be used everywhere to ensure consistency. /// You may want to also use `output_fileline`. -fn output(w: &mut Write, idx: usize, frame: Frame, +fn output(w: &mut dyn Write, idx: usize, frame: Frame, s: Option<&str>, format: PrintFormat) -> io::Result<()> { // Remove the `17: 0x0 - ` line. if format == PrintFormat::Short && frame.exact_position == ptr::null() { @@ -202,7 +202,7 @@ fn output(w: &mut Write, idx: usize, frame: Frame, /// /// See also `output`. #[allow(dead_code)] -fn output_fileline(w: &mut Write, +fn output_fileline(w: &mut dyn Write, file: &[u8], line: u32, format: PrintFormat) -> io::Result<()> { @@ -254,7 +254,7 @@ fn output_fileline(w: &mut Write, // Note that this demangler isn't quite as fancy as it could be. We have lots // of other information in our symbols like hashes, version, type information, // etc. Additionally, this doesn't handle glue symbols at all. -pub fn demangle(writer: &mut Write, mut s: &str, format: PrintFormat) -> io::Result<()> { +pub fn demangle(writer: &mut dyn Write, mut s: &str, format: PrintFormat) -> io::Result<()> { // During ThinLTO LLVM may import and rename internal symbols, so strip out // those endings first as they're one of the last manglings applied to // symbol names. diff --git a/src/libstd/sys_common/poison.rs b/src/libstd/sys_common/poison.rs index e74c40ae04b..1625efe4a2a 100644 --- a/src/libstd/sys_common/poison.rs +++ b/src/libstd/sys_common/poison.rs @@ -251,7 +251,7 @@ impl Error for TryLockError { } } - fn cause(&self) -> Option<&Error> { + fn cause(&self) -> Option<&dyn Error> { match *self { TryLockError::Poisoned(ref p) => Some(p), _ => None diff --git a/src/libstd/sys_common/thread.rs b/src/libstd/sys_common/thread.rs index da6f58ef6bb..86a5e2b8694 100644 --- a/src/libstd/sys_common/thread.rs +++ b/src/libstd/sys_common/thread.rs @@ -21,7 +21,7 @@ pub unsafe fn start_thread(main: *mut u8) { let _handler = stack_overflow::Handler::new(); // Finally, let's run some code. - Box::from_raw(main as *mut Box)() + Box::from_raw(main as *mut Box)() } pub fn min_stack() -> usize { diff --git a/src/libstd/thread/mod.rs b/src/libstd/thread/mod.rs index 90f054186d1..cc0ec8a5b4d 100644 --- a/src/libstd/thread/mod.rs +++ b/src/libstd/thread/mod.rs @@ -1175,7 +1175,7 @@ impl fmt::Debug for Thread { /// /// [`Result`]: ../../std/result/enum.Result.html #[stable(feature = "rust1", since = "1.0.0")] -pub type Result = ::result::Result>; +pub type Result = ::result::Result>; // This packet is used to communicate the return value between the child thread // and the parent thread. Memory is shared through the `Arc` within and there's -- cgit 1.4.1-3-g733a5 From 0f3f292b4c7a15b656a925e7ebe5f2d3955b8553 Mon Sep 17 00:00:00 2001 From: Christopher Durham Date: Tue, 10 Jul 2018 22:47:59 -0400 Subject: remove sync::Once::call_once 'static - [std: Rewrite the `sync` modulehttps://github.com/rust-lang/rust/commit/71d4e77db8ad4b6d821da7e5d5300134ac95974e) (Nov 2014) ```diff - pub fn doit(&self, f: ||) { + pub fn doit(&'static self, f: ||) { ``` > ```text > The second layer is the layer provided by `std::sync` which is intended to be > the thinnest possible layer on top of `sys_common` which is entirely safe to > use. There are a few concerns which need to be addressed when making these > system primitives safe: > > * Once used, the OS primitives can never be **moved**. This means that they > essentially need to have a stable address. The static primitives use > `&'static self` to enforce this, and the non-static primitives all use a > `Box` to provide this guarantee. > ``` The author of this diff is @alexcrichton. `sync::Once` contains only a pointer to (privately hidden) `Waiter`s, which are all stack-allocated. The `'static` bound to `sync::Once` is thus unnecessary to guarantee that any OS primitives are non-relocatable. See https://internals.rust-lang.org/t/sync-once-per-instance/7918 for more context. --- src/libstd/sync/once.rs | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) (limited to 'src/libstd/sync') diff --git a/src/libstd/sync/once.rs b/src/libstd/sync/once.rs index 7eb7be23128..51c42995d5e 100644 --- a/src/libstd/sync/once.rs +++ b/src/libstd/sync/once.rs @@ -149,9 +149,9 @@ struct Waiter { // Helper struct used to clean up after a closure call with a `Drop` // implementation to also run on panic. -struct Finish { +struct Finish<'a> { panicked: bool, - me: &'static Once, + me: &'a Once, } impl Once { @@ -218,7 +218,7 @@ impl Once { /// /// [poison]: struct.Mutex.html#poisoning #[stable(feature = "rust1", since = "1.0.0")] - pub fn call_once(&'static self, f: F) where F: FnOnce() { + pub fn call_once(&self, f: F) where F: FnOnce() { // Fast path, just see if we've completed initialization. if self.state.load(Ordering::SeqCst) == COMPLETE { return @@ -275,7 +275,7 @@ impl Once { /// INIT.call_once(|| {}); /// ``` #[unstable(feature = "once_poison", issue = "33577")] - pub fn call_once_force(&'static self, f: F) where F: FnOnce(&OnceState) { + pub fn call_once_force(&self, f: F) where F: FnOnce(&OnceState) { // same as above, just with a different parameter to `call_inner`. if self.state.load(Ordering::SeqCst) == COMPLETE { return @@ -299,7 +299,7 @@ impl Once { // currently no way to take an `FnOnce` and call it via virtual dispatch // without some allocation overhead. #[cold] - fn call_inner(&'static self, + fn call_inner(&self, ignore_poisoning: bool, init: &mut FnMut(bool)) { let mut state = self.state.load(Ordering::SeqCst); @@ -390,7 +390,7 @@ impl fmt::Debug for Once { } } -impl Drop for Finish { +impl<'a> Drop for Finish<'a> { fn drop(&mut self) { // Swap out our state with however we finished. We should only ever see // an old state which was RUNNING. -- cgit 1.4.1-3-g733a5 From e488cba6784eebc36b9869239b729a4e41048d3f Mon Sep 17 00:00:00 2001 From: Matt Kraai Date: Wed, 11 Jul 2018 17:19:41 -0700 Subject: Uncapitalize "If" --- src/libstd/sync/mpsc/mod.rs | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'src/libstd/sync') diff --git a/src/libstd/sync/mpsc/mod.rs b/src/libstd/sync/mpsc/mod.rs index 2dd3aebe610..cbda5afadcd 100644 --- a/src/libstd/sync/mpsc/mod.rs +++ b/src/libstd/sync/mpsc/mod.rs @@ -689,7 +689,7 @@ impl UnsafeFlavor for Receiver { /// only one [`Receiver`] is supported. /// /// If the [`Receiver`] is disconnected while trying to [`send`] with the -/// [`Sender`], the [`send`] method will return a [`SendError`]. Similarly, If the +/// [`Sender`], the [`send`] method will return a [`SendError`]. Similarly, if the /// [`Sender`] is disconnected while trying to [`recv`], the [`recv`] method will /// return a [`RecvError`]. /// -- cgit 1.4.1-3-g733a5 From 3e1254d956d944a2909f61f733427350cd96f410 Mon Sep 17 00:00:00 2001 From: Ralf Jung Date: Tue, 17 Jul 2018 20:51:31 +0200 Subject: sync::Once: Use Acquire on the hot path, and explain why we don't use it elsewhere --- src/libstd/sync/once.rs | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) (limited to 'src/libstd/sync') diff --git a/src/libstd/sync/once.rs b/src/libstd/sync/once.rs index 51c42995d5e..443e2a6980d 100644 --- a/src/libstd/sync/once.rs +++ b/src/libstd/sync/once.rs @@ -220,7 +220,11 @@ impl Once { #[stable(feature = "rust1", since = "1.0.0")] pub fn call_once(&self, f: F) where F: FnOnce() { // Fast path, just see if we've completed initialization. - if self.state.load(Ordering::SeqCst) == COMPLETE { + // An `Acquire` load is enough because that makes all the initialization + // operations visible to us. The cold path uses SeqCst consistently + // because the performance difference really does not matter there, + // and SeqCst minimizes the chances of something going wrong. + if self.state.load(Ordering::Acquire) == COMPLETE { return } @@ -277,7 +281,11 @@ impl Once { #[unstable(feature = "once_poison", issue = "33577")] pub fn call_once_force(&self, f: F) where F: FnOnce(&OnceState) { // same as above, just with a different parameter to `call_inner`. - if self.state.load(Ordering::SeqCst) == COMPLETE { + // An `Acquire` load is enough because that makes all the initialization + // operations visible to us. The cold path uses SeqCst consistently + // because the performance difference really does not matter there, + // and SeqCst minimizes the chances of something going wrong. + if self.state.load(Ordering::Acquire) == COMPLETE { return } -- cgit 1.4.1-3-g733a5 From c3fdd19e43e0e0ecb7d12e15b0892dbe6139798d Mon Sep 17 00:00:00 2001 From: Felix Rabe Date: Wed, 1 Aug 2018 09:42:46 +0200 Subject: Document #39364 (WIP) --- src/libstd/sync/mpsc/mod.rs | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'src/libstd/sync') diff --git a/src/libstd/sync/mpsc/mod.rs b/src/libstd/sync/mpsc/mod.rs index 02a96b01cca..fc0e37f150e 100644 --- a/src/libstd/sync/mpsc/mod.rs +++ b/src/libstd/sync/mpsc/mod.rs @@ -1247,6 +1247,12 @@ impl Receiver { /// [`SyncSender`]: struct.SyncSender.html /// [`Err`]: ../../../std/result/enum.Result.html#variant.Err /// + /// # Panics + /// + /// Panics due to a known issue ([`#39364`][]). + /// + /// [`#39364`]: https://github.com/rust-lang/rust/issues/39364 + /// /// # Examples /// /// Successfully receiving value before encountering timeout: -- cgit 1.4.1-3-g733a5 From 94de821002f3378a59c2bf812ce73756f3ed0512 Mon Sep 17 00:00:00 2001 From: Aleksey Kladov Date: Fri, 3 Aug 2018 14:18:06 +0300 Subject: Specify reentrancy gurantees of `Once::call_once` --- src/libstd/sync/once.rs | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'src/libstd/sync') diff --git a/src/libstd/sync/once.rs b/src/libstd/sync/once.rs index 10282ecb658..113fbbf1f61 100644 --- a/src/libstd/sync/once.rs +++ b/src/libstd/sync/once.rs @@ -178,6 +178,10 @@ impl Once { /// happens-before relation between the closure and code executing after the /// return). /// + /// If the given closure recusively invokes `call_once` on the same `Once` + /// instance the exact behavior is not specified, allowed outcomes are + /// a panic or a deadlock. + /// /// # Examples /// /// ``` -- cgit 1.4.1-3-g733a5 From a2f9aaf7a35e673c3b8f0825a07505b0294aa24f Mon Sep 17 00:00:00 2001 From: Aleksey Kladov Date: Fri, 3 Aug 2018 16:50:30 +0300 Subject: Fix trailnig WS --- src/libstd/sync/once.rs | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'src/libstd/sync') diff --git a/src/libstd/sync/once.rs b/src/libstd/sync/once.rs index 113fbbf1f61..3abc260b458 100644 --- a/src/libstd/sync/once.rs +++ b/src/libstd/sync/once.rs @@ -178,7 +178,7 @@ impl Once { /// happens-before relation between the closure and code executing after the /// return). /// - /// If the given closure recusively invokes `call_once` on the same `Once` + /// If the given closure recusively invokes `call_once` on the same `Once` /// instance the exact behavior is not specified, allowed outcomes are /// a panic or a deadlock. /// -- cgit 1.4.1-3-g733a5 From a92b5cc916a42c6f3425347281bb656d071c26d5 Mon Sep 17 00:00:00 2001 From: Ralf Jung Date: Mon, 6 Aug 2018 12:34:00 +0200 Subject: Remove references to `StaticMutex` which got removed a while ago --- src/librustc_mir/diagnostics.rs | 4 +--- src/libstd/sync/once.rs | 10 ++++------ src/libstd/sys/unix/mutex.rs | 3 --- 3 files changed, 5 insertions(+), 12 deletions(-) (limited to 'src/libstd/sync') diff --git a/src/librustc_mir/diagnostics.rs b/src/librustc_mir/diagnostics.rs index 3c751d52b06..714218a0417 100644 --- a/src/librustc_mir/diagnostics.rs +++ b/src/librustc_mir/diagnostics.rs @@ -1281,9 +1281,7 @@ const F: &'static C = &D; // error ``` This is because cell types do operations that are not thread-safe. Due to this, -they don't implement Sync and thus can't be placed in statics. In this -case, `StaticMutex` would work just fine, but it isn't stable yet: -https://doc.rust-lang.org/nightly/std/sync/struct.StaticMutex.html +they don't implement Sync and thus can't be placed in statics. However, if you still wish to use these types, you can achieve this by an unsafe wrapper: diff --git a/src/libstd/sync/once.rs b/src/libstd/sync/once.rs index 3abc260b458..f6cb8beae84 100644 --- a/src/libstd/sync/once.rs +++ b/src/libstd/sync/once.rs @@ -31,12 +31,10 @@ // initialization closure panics, the Once enters a "poisoned" state which means // that all future calls will immediately panic as well. // -// So to implement this, one might first reach for a `StaticMutex`, but those -// unfortunately need to be deallocated (e.g. call `destroy()`) to free memory -// on all OSes (some of the BSDs allocate memory for mutexes). It also gets a -// lot harder with poisoning to figure out when the mutex needs to be -// deallocated because it's not after the closure finishes, but after the first -// successful closure finishes. +// So to implement this, one might first reach for a `Mutex`, but those cannot +// be put into a `static`. It also gets a lot harder with poisoning to figure +// out when the mutex needs to be deallocated because it's not after the closure +// finishes, but after the first successful closure finishes. // // All in all, this is instead implemented with atomics and lock-free // operations! Whee! Each `Once` has one word of atomic state, and this state is diff --git a/src/libstd/sys/unix/mutex.rs b/src/libstd/sys/unix/mutex.rs index 52cf3f97c5c..60b03cdbeb0 100644 --- a/src/libstd/sys/unix/mutex.rs +++ b/src/libstd/sys/unix/mutex.rs @@ -49,9 +49,6 @@ impl Mutex { // references, we instead create the mutex with type // PTHREAD_MUTEX_NORMAL which is guaranteed to deadlock if we try to // re-lock it from the same thread, thus avoiding undefined behavior. - // - // We can't do anything for StaticMutex, but that type is deprecated - // anyways. let mut attr: libc::pthread_mutexattr_t = mem::uninitialized(); let r = libc::pthread_mutexattr_init(&mut attr); debug_assert_eq!(r, 0); -- cgit 1.4.1-3-g733a5 From b1f47aa8380c8dbe7fbd2d96d685cd1f28cc1a6d Mon Sep 17 00:00:00 2001 From: Felix Rabe Date: Tue, 7 Aug 2018 16:35:03 +0200 Subject: Document panic in mpsc::Receiver::recv_timeout --- src/libstd/sync/mpsc/mod.rs | 24 +++++++++++++++++++++++- 1 file changed, 23 insertions(+), 1 deletion(-) (limited to 'src/libstd/sync') diff --git a/src/libstd/sync/mpsc/mod.rs b/src/libstd/sync/mpsc/mod.rs index fc0e37f150e..e82f40ff96f 100644 --- a/src/libstd/sync/mpsc/mod.rs +++ b/src/libstd/sync/mpsc/mod.rs @@ -1249,7 +1249,29 @@ impl Receiver { /// /// # Panics /// - /// Panics due to a known issue ([`#39364`][]). + /// There is currently a known issue with this function ([`#39364`]) that + /// causes `recv_timeout` to panic unexpectedly with the following example: + /// + /// ```no_run + /// use std::sync::mpsc::channel; + /// use std::thread; + /// use std::time::Duration; + /// + /// let (tx, rx) = channel::(); + /// + /// thread::spawn(move || { + /// let d = Duration::from_millis(10); + /// loop { + /// println!("recv"); + /// let _r = rx.recv_timeout(d); + /// } + /// }); + /// + /// thread::sleep(Duration::from_millis(100)); + /// let _c1 = tx.clone(); + /// + /// thread::sleep(Duration::from_secs(1)); + /// ``` /// /// [`#39364`]: https://github.com/rust-lang/rust/issues/39364 /// -- cgit 1.4.1-3-g733a5 From c574720d88f9310ed3fc0489c9a8d5c3ef832c2c Mon Sep 17 00:00:00 2001 From: Felix Rabe Date: Tue, 7 Aug 2018 16:38:02 +0200 Subject: Rephrase --- src/libstd/sync/mpsc/mod.rs | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'src/libstd/sync') diff --git a/src/libstd/sync/mpsc/mod.rs b/src/libstd/sync/mpsc/mod.rs index e82f40ff96f..de553556207 100644 --- a/src/libstd/sync/mpsc/mod.rs +++ b/src/libstd/sync/mpsc/mod.rs @@ -1249,8 +1249,8 @@ impl Receiver { /// /// # Panics /// - /// There is currently a known issue with this function ([`#39364`]) that - /// causes `recv_timeout` to panic unexpectedly with the following example: + /// There is currently a known issue with this `recv_timeout` (see [`#39364`]) + /// that causes it to panic unexpectedly with the following example: /// /// ```no_run /// use std::sync::mpsc::channel; -- cgit 1.4.1-3-g733a5 From 6e2051cd084aee3aa5cef0d8ec65fc564f86ed1c Mon Sep 17 00:00:00 2001 From: Felix Rabe Date: Tue, 7 Aug 2018 16:39:09 +0200 Subject: Less words better than moar words --- src/libstd/sync/mpsc/mod.rs | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'src/libstd/sync') diff --git a/src/libstd/sync/mpsc/mod.rs b/src/libstd/sync/mpsc/mod.rs index de553556207..21a6adf5827 100644 --- a/src/libstd/sync/mpsc/mod.rs +++ b/src/libstd/sync/mpsc/mod.rs @@ -1249,8 +1249,8 @@ impl Receiver { /// /// # Panics /// - /// There is currently a known issue with this `recv_timeout` (see [`#39364`]) - /// that causes it to panic unexpectedly with the following example: + /// There is currently a known issue (see [`#39364`]) that causes `recv_timeout` + /// to panic unexpectedly with the following example: /// /// ```no_run /// use std::sync::mpsc::channel; -- cgit 1.4.1-3-g733a5 From 025f41f4c0db5ed65ae6a15ec8bb4e5872bc16ff Mon Sep 17 00:00:00 2001 From: Felix Rabe Date: Tue, 7 Aug 2018 17:34:34 +0200 Subject: "Panics" -> "Known Issues"; rm trailing WS --- src/libstd/sync/mpsc/mod.rs | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'src/libstd/sync') diff --git a/src/libstd/sync/mpsc/mod.rs b/src/libstd/sync/mpsc/mod.rs index 21a6adf5827..59cf741487e 100644 --- a/src/libstd/sync/mpsc/mod.rs +++ b/src/libstd/sync/mpsc/mod.rs @@ -1247,7 +1247,7 @@ impl Receiver { /// [`SyncSender`]: struct.SyncSender.html /// [`Err`]: ../../../std/result/enum.Result.html#variant.Err /// - /// # Panics + /// # Known Issues /// /// There is currently a known issue (see [`#39364`]) that causes `recv_timeout` /// to panic unexpectedly with the following example: @@ -1256,7 +1256,7 @@ impl Receiver { /// use std::sync::mpsc::channel; /// use std::thread; /// use std::time::Duration; - /// + /// /// let (tx, rx) = channel::(); /// /// thread::spawn(move || { -- cgit 1.4.1-3-g733a5