rust/patches/0018-Add-FnBox-back.patch

From 8617310c3c9e192080df6a0c7b4835d3f02e27b9 Mon Sep 17 00:00:00 2001
From: bjorn3 <bjorn3@users.noreply.github.com>
Date: Fri, 1 Nov 2019 20:58:30 +0100
Subject: [PATCH] Add FnBox back

---
 src/liballoc/boxed.rs                | 13 +++++++++++++
 src/libstd/prelude/v1.rs             |  2 +-
 src/libstd/sys/cloudabi/thread.rs    |  2 +-
 src/libstd/sys/hermit/thread.rs      |  4 ++--
 src/libstd/sys/unix/thread.rs        |  4 ++--
 src/libstd/sys_common/at_exit_imp.rs |  6 +++---
 src/libstd/sys_common/mod.rs         |  2 +-
 src/libstd/sys_common/thread.rs      |  2 +-
 src/libstd/thread/mod.rs             |  2 +-
 9 files changed, 25 insertions(+), 12 deletions(-)

diff --git a/src/liballoc/boxed.rs b/src/liballoc/boxed.rs
index ef9b648..e32b870 100644
--- a/src/liballoc/boxed.rs
+++ b/src/liballoc/boxed.rs
@@ -1079,3 +1079,16 @@ impl<F: ?Sized + Future + Unpin> Future for Box<F> {
         F::poll(Pin::new(&mut *self), cx)
     }
 }
+
+#[stable(feature = "rust1", since = "1.0.0")]
+pub trait FnBox<A>: FnOnce<A> {
+    #[stable(feature = "rust1", since = "1.0.0")]
+    extern "rust-call" fn call_box(self: Box<Self>, args: A) -> Self::Output;
+}
+
+#[stable(feature = "rust1", since = "1.0.0")]
+impl<A, F: FnOnce<A>> FnBox<A> for F {
+    extern "rust-call" fn call_box(self: Box<Self>, args: A) -> Self::Output {
+        <F as FnOnce<A>>::call_once(*self, args)
+    }
+}
diff --git a/src/libstd/prelude/v1.rs b/src/libstd/prelude/v1.rs
index 3e4cf91..1f50eb3 100644
--- a/src/libstd/prelude/v1.rs
+++ b/src/libstd/prelude/v1.rs
@@ -94,6 +94,6 @@ pub use core::prelude::v1::{
 #[stable(feature = "rust1", since = "1.0.0")]
 #[doc(no_inline)]
-pub use crate::boxed::Box;
+pub use crate::boxed::{Box, FnBox};
 #[stable(feature = "rust1", since = "1.0.0")]
 #[doc(no_inline)]
 pub use crate::string::{String, ToString};
diff --git a/src/libstd/sys/cloudabi/thread.rs b/src/libstd/sys/cloudabi/thread.rs
index 240b6ea..6f71c6b 100644
--- a/src/libstd/sys/cloudabi/thread.rs
+++ b/src/libstd/sys/cloudabi/thread.rs
@@ -21,7 +21,7 @@ unsafe impl Sync for Thread {}
 
 impl Thread {
     // unsafe: see thread::Builder::spawn_unchecked for safety requirements
-    pub unsafe fn new(stack: usize, p: Box<dyn FnOnce()>) -> io::Result<Thread> {
+    pub unsafe fn new(stack: usize, p: Box<dyn FnBox()>) -> io::Result<Thread> {
         let p = box p;
         let mut native: libc::pthread_t = mem::zeroed();
         let mut attr: libc::pthread_attr_t = mem::zeroed();
diff --git a/src/libstd/sys/hermit/thread.rs b/src/libstd/sys/hermit/thread.rs
index 99a9c83..b8bc392 100644
--- a/src/libstd/sys/hermit/thread.rs
+++ b/src/libstd/sys/hermit/thread.rs
@@ -44,9 +44,9 @@ unsafe impl Sync for Thread {}
 pub const DEFAULT_MIN_STACK_SIZE: usize = 262144;
 
 impl Thread {
     pub unsafe fn new_with_coreid(
         _stack: usize,
-        p: Box<dyn FnOnce()>,
+        p: Box<dyn FnBox()>,
         core_id: isize,
     ) -> io::Result<Thread> {
         let p = box p;
@@ -67,7 +67,7 @@ impl Thread {
         }
     }
 
-    pub unsafe fn new(stack: usize, p: Box<dyn FnOnce()>) -> io::Result<Thread> {
+    pub unsafe fn new(stack: usize, p: Box<dyn FnBox()>) -> io::Result<Thread> {
         Thread::new_with_coreid(stack, p, -1 /* = no specific core */)
     }
 
diff --git a/src/libstd/sys/unix/thread.rs b/src/libstd/sys/unix/thread.rs
index 143cf2f..a6e8faf 100644
--- a/src/libstd/sys/unix/thread.rs
+++ b/src/libstd/sys/unix/thread.rs
@@ -38,8 +38,8 @@ unsafe fn pthread_attr_setstacksize(_attr: *mut libc::pthread_attr_t,
 
 impl Thread {
     // unsafe: see thread::Builder::spawn_unchecked for safety requirements
-    pub unsafe fn new(stack: usize, p: Box<dyn FnOnce()>) -> io::Result<Thread> {
+    pub unsafe fn new(stack: usize, p: Box<dyn FnBox()>) -> io::Result<Thread> {
         panic!("Warning: Threads are not yet fully supported, because cranelift doesn't support atomics.");
 
         let p = box p;
         let mut native: libc::pthread_t = mem::zeroed();
diff --git a/src/libstd/sys_common/at_exit_imp.rs b/src/libstd/sys_common/at_exit_imp.rs
index cdb72ee..e523333 100644
--- a/src/libstd/sys_common/at_exit_imp.rs
+++ b/src/libstd/sys_common/at_exit_imp.rs
@@ -6,7 +6,7 @@ use crate::mem;
 use crate::ptr;
 use crate::sys_common::mutex::Mutex;
 
-type Queue = Vec<Box<dyn FnOnce()>>;
+type Queue = Vec<Box<dyn FnBox()>>;
 
 // 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
@@ -53,14 +53,14 @@ pub fn cleanup() {
                 let queue: Box<Queue> = Box::from_raw(queue);
                 for to_run in *queue {
                     // We are not holding any lock, so reentrancy is fine.
-                    to_run();
+                    to_run.call_box(());
                 }
             }
         }
     }
 }
 
-pub fn push(f: Box<dyn FnOnce()>) -> bool {
+pub fn push(f: Box<dyn FnBox()>) -> bool {
     unsafe {
         let _guard = LOCK.lock();
         if init() {
diff --git a/src/libstd/sys_common/mod.rs b/src/libstd/sys_common/mod.rs
index 7a0bcd0..668bef2 100644
--- a/src/libstd/sys_common/mod.rs
+++ b/src/libstd/sys_common/mod.rs
@@ -113,7 +113,7 @@ pub trait FromInner<Inner> {
 /// closure will be run once the main thread exits. Returns `Err` to indicate
 /// that the closure could not be registered, meaning that it is not scheduled
 /// to be run.
-pub fn at_exit<F: FnOnce() + Send + 'static>(f: F) -> Result<(), ()> {
+pub fn at_exit<F: FnBox() + Send + 'static>(f: F) -> Result<(), ()> {
     if at_exit_imp::push(Box::new(f)) { Ok(()) } else { Err(()) }
 }
 
diff --git a/src/libstd/sys_common/thread.rs b/src/libstd/sys_common/thread.rs
index c638be9..5c18a18 100644
--- a/src/libstd/sys_common/thread.rs
+++ b/src/libstd/sys_common/thread.rs
@@ -10,7 +10,7 @@ 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<dyn FnBox()>)()
+    Box::from_raw(main as *mut Box<dyn FnBox()>).call_box(())
 }
 
 pub fn min_stack() -> usize {
diff --git a/src/libstd/thread/mod.rs b/src/libstd/thread/mod.rs
index 0ffa6ac..4a3e3d6 100644
--- a/src/libstd/thread/mod.rs
+++ b/src/libstd/thread/mod.rs
@@ -485,7 +485,7 @@ impl Builder {
             // returning.
             native: Some(imp::Thread::new(
                 stack_size,
-                mem::transmute::<Box<dyn FnOnce() + 'a>, Box<dyn FnOnce() + 'static>>(Box::new(
+                mem::transmute::<Box<dyn FnBox() + 'a>, Box<dyn FnBox() + 'static>>(Box::new(
                     main,
                 )),
             )?),
-- 
2.20.1