Merge pull request #209 from rust-lang/2022-08-26_sync_from_rust

2022/08/26 sync from rust

3 files changed, 48 insertions, 16 deletions

diff --git a/example/alloc_system.rs b/example/alloc_system.rs
index 5f66ca67f2d..89661918d05 100644
--- a/example/alloc_system.rs
+++ b/example/alloc_system.rs
@@ -156,7 +156,7 @@ mod platform {
     struct Header(*mut u8);
     const HEAP_ZERO_MEMORY: DWORD = 0x00000008;
     unsafe fn get_header<'a>(ptr: *mut u8) -> &'a mut Header {
-        &mut *(ptr as *mut Header).offset(-1)
+        &mut *(ptr as *mut Header).sub(1)
     }
     unsafe fn align_ptr(ptr: *mut u8, align: usize) -> *mut u8 {
         let aligned = ptr.add(align - (ptr as usize & (align - 1)));
diff --git a/example/mini_core.rs b/example/mini_core.rs
index a8435287d9f..b23ecda35d3 100644
--- a/example/mini_core.rs
+++ b/example/mini_core.rs
@@ -1,6 +1,6 @@
 #![feature(
     no_core, lang_items, intrinsics, unboxed_closures, type_ascription, extern_types,
-    untagged_unions, decl_macro, rustc_attrs, transparent_unions, auto_traits,
+    decl_macro, rustc_attrs, transparent_unions, auto_traits,
     thread_local
 )]
 #![no_core]
@@ -39,14 +39,14 @@ impl<'a, T: ?Sized+Unsize<U>, U: ?Sized> DispatchFromDyn<&'a mut U> for &'a mut
 impl<T: ?Sized+Unsize<U>, U: ?Sized> DispatchFromDyn<*const U> for *const T {}
 // *mut T -> *mut U
 impl<T: ?Sized+Unsize<U>, U: ?Sized> DispatchFromDyn<*mut U> for *mut T {}
-impl<T: ?Sized + Unsize<U>, U: ?Sized> DispatchFromDyn<Box<U>> for Box<T> {}
+impl<T: ?Sized + Unsize<U>, U: ?Sized> DispatchFromDyn<Box<U, ()>> for Box<T, ()> {}
 
 #[lang = "receiver"]
 pub trait Receiver {}
 
 impl<T: ?Sized> Receiver for &T {}
 impl<T: ?Sized> Receiver for &mut T {}
-impl<T: ?Sized> Receiver for Box<T> {}
+impl<T: ?Sized, A: Allocator> Receiver for Box<T, A> {}
 
 #[lang = "copy"]
 pub unsafe trait Copy {}
@@ -411,7 +411,15 @@ pub trait FnMut<Args>: FnOnce<Args> {
 
 #[lang = "panic"]
 #[track_caller]
-pub fn panic(_msg: &str) -> ! {
+pub fn panic(_msg: &'static str) -> ! {
+    unsafe {
+        libc::puts("Panicking\n\0" as *const str as *const u8);
+        intrinsics::abort();
+    }
+}
+
+#[lang = "panic_no_unwind"]
+fn panic_no_unwind() -> ! {
     unsafe {
         libc::puts("Panicking\n\0" as *const str as *const u8);
         intrinsics::abort();
@@ -450,17 +458,32 @@ pub trait Deref {
 pub trait Allocator {
 }
 
+impl Allocator for () {}
+
 pub struct Global;
 
 impl Allocator for Global {}
 
+#[repr(transparent)]
+#[rustc_layout_scalar_valid_range_start(1)]
+#[rustc_nonnull_optimization_guaranteed]
+pub struct NonNull<T: ?Sized>(pub *const T);
+
+impl<T: ?Sized, U: ?Sized> CoerceUnsized<NonNull<U>> for NonNull<T> where T: Unsize<U> {}
+impl<T: ?Sized, U: ?Sized> DispatchFromDyn<NonNull<U>> for NonNull<T> where T: Unsize<U> {}
+
+pub struct Unique<T: ?Sized> {
+    pub pointer: NonNull<T>,
+    pub _marker: PhantomData<T>,
+}
+
+impl<T: ?Sized, U: ?Sized> CoerceUnsized<Unique<U>> for Unique<T> where T: Unsize<U> {}
+impl<T: ?Sized, U: ?Sized> DispatchFromDyn<Unique<U>> for Unique<T> where T: Unsize<U> {}
+
 #[lang = "owned_box"]
-pub struct Box<
-    T: ?Sized,
-    A: Allocator = Global,
->(*mut T, A);
+pub struct Box<T: ?Sized, A: Allocator = Global>(Unique<T>, A);
 
-impl<T: ?Sized + Unsize<U>, U: ?Sized> CoerceUnsized<Box<U>> for Box<T> {}
+impl<T: ?Sized + Unsize<U>, U: ?Sized, A: Allocator> CoerceUnsized<Box<U, A>> for Box<T, A> {}
 
 impl<T: ?Sized, A: Allocator> Drop for Box<T, A> {
     fn drop(&mut self) {
@@ -468,7 +491,7 @@ impl<T: ?Sized, A: Allocator> Drop for Box<T, A> {
     }
 }
 
-impl<T> Deref for Box<T> {
+impl<T: ?Sized, A: Allocator> Deref for Box<T, A> {
     type Target = T;
 
     fn deref(&self) -> &Self::Target {
@@ -482,8 +505,8 @@ unsafe fn allocate(size: usize, _align: usize) -> *mut u8 {
 }
 
 #[lang = "box_free"]
-unsafe fn box_free<T: ?Sized, A: Allocator>(ptr: *mut T, alloc: A) {
-    libc::free(ptr as *mut u8);
+unsafe fn box_free<T: ?Sized>(ptr: Unique<T>, _alloc: ()) {
+    libc::free(ptr.pointer.0 as *mut u8);
 }
 
 #[lang = "drop"]
@@ -505,16 +528,18 @@ pub union MaybeUninit<T> {
 }
 
 pub mod intrinsics {
+    use crate::Sized;
+
     extern "rust-intrinsic" {
         pub fn abort() -> !;
         pub fn size_of<T>() -> usize;
-        pub fn size_of_val<T: ?::Sized>(val: *const T) -> usize;
+        pub fn size_of_val<T: ?Sized>(val: *const T) -> usize;
         pub fn min_align_of<T>() -> usize;
-        pub fn min_align_of_val<T: ?::Sized>(val: *const T) -> usize;
+        pub fn min_align_of_val<T: ?Sized>(val: *const T) -> usize;
         pub fn copy<T>(src: *const T, dst: *mut T, count: usize);
         pub fn transmute<T, U>(e: T) -> U;
         pub fn ctlz_nonzero<T>(x: T) -> T;
-        pub fn needs_drop<T>() -> bool;
+        pub fn needs_drop<T: ?Sized>() -> bool;
         pub fn bitreverse<T>(x: T) -> T;
         pub fn bswap<T>(x: T) -> T;
         pub fn write_bytes<T>(dst: *mut T, val: u8, count: usize);
diff --git a/example/mini_core_hello_world.rs b/example/mini_core_hello_world.rs
index 69d591565ac..14fd9eeffa6 100644
--- a/example/mini_core_hello_world.rs
+++ b/example/mini_core_hello_world.rs
@@ -47,6 +47,11 @@ struct NoisyDrop {
     inner: NoisyDropInner,
 }
 
+struct NoisyDropUnsized {
+    inner: NoisyDropInner,
+    text: str,
+}
+
 struct NoisyDropInner;
 
 impl Drop for NoisyDrop {
@@ -184,7 +189,9 @@ fn main() {
         assert_eq!(intrinsics::min_align_of_val(&a) as u8, intrinsics::min_align_of::<&str>() as u8);
 
         assert!(!intrinsics::needs_drop::<u8>());
+        assert!(!intrinsics::needs_drop::<[u8]>());
         assert!(intrinsics::needs_drop::<NoisyDrop>());
+        assert!(intrinsics::needs_drop::<NoisyDropUnsized>());
 
         Unique {
             pointer: 0 as *const &str,