Sync from rust a5c825cd824ee0ef9463021078a2f464b4cc1a0d

Author: bjorn3

example/mini_core.rs

@@ -7,13 +7,38 @@
     decl_macro,
     rustc_attrs,
     transparent_unions,
+    pattern_types,
     auto_traits,
     freeze_impls
 )]
 #![cfg_attr(not(all(windows, target_env = "gnu")), feature(thread_local))]
 #![no_core]
 #![allow(dead_code, internal_features, ambiguous_wide_pointer_comparisons)]
 
+#[lang = "pointee_trait"]
+pub trait Pointee: PointeeSized {
+    #[lang = "metadata_type"]
+    // needed so that layout_of will return `TooGeneric` instead of `Unknown`
+    // when asked for the layout of `*const T`. Which is important for making
+    // transmutes between raw pointers (and especially pattern types of raw pointers)
+    // work.
+    type Metadata: Copy + Sync + Unpin + Freeze;
+}
+
+#[lang = "dyn_metadata"]
+pub struct DynMetadata<Dyn: PointeeSized> {
+    _vtable_ptr: NonNull<VTable>,
+    _phantom: PhantomData<Dyn>,
+}
+
+unsafe extern "C" {
+    /// Opaque type for accessing vtables.
+    ///
+    /// Private implementation detail of `DynMetadata::size_of` etc.
+    /// There is conceptually not actually any Abstract Machine memory behind this pointer.
+    type VTable;
+}
+
 #[lang = "pointee_sized"]
 pub trait PointeeSized {}
 
@@ -104,7 +129,7 @@ unsafe impl<'a, T: PointeeSized> Sync for &'a T {}
 unsafe impl<T: Sync, const N: usize> Sync for [T; N] {}
 
 #[lang = "freeze"]
-unsafe auto trait Freeze {}
+pub unsafe auto trait Freeze {}
 
 unsafe impl<T: PointeeSized> Freeze for PhantomData<T> {}
 unsafe impl<T: PointeeSized> Freeze for *const T {}
@@ -569,10 +594,24 @@ pub trait Deref {
     fn deref(&self) -> &Self::Target;
 }
 
+#[rustc_builtin_macro(pattern_type)]
+#[macro_export]
+macro_rules! pattern_type {
+    ($($arg:tt)*) => {
+        /* compiler built-in */
+    };
+}
+
+impl<T: PointeeSized, U: PointeeSized> CoerceUnsized<pattern_type!(*const U is !null)> for pattern_type!(*const T is !null) where
+    T: Unsize<U>
+{
+}
+
+impl<T: DispatchFromDyn<U>, U> DispatchFromDyn<pattern_type!(U is !null)> for pattern_type!(T is !null) {}
+
 #[repr(transparent)]
-#[rustc_layout_scalar_valid_range_start(1)]
 #[rustc_nonnull_optimization_guaranteed]
-pub struct NonNull<T: PointeeSized>(pub *const T);
+pub struct NonNull<T: PointeeSized>(pub pattern_type!(*const T is !null));
 
 impl<T: PointeeSized, U: PointeeSized> CoerceUnsized<NonNull<U>> for NonNull<T> where T: Unsize<U> {}
 impl<T: PointeeSized, U: PointeeSized> DispatchFromDyn<NonNull<U>> for NonNull<T> where T: Unsize<U> {}
@@ -599,7 +638,16 @@ impl<T> Box<T> {
             let size = size_of::<T>();
             let ptr = libc::malloc(size);
             intrinsics::copy(&val as *const T as *const u8, ptr, size);
-            Box(Unique { pointer: NonNull(ptr as *const T), _marker: PhantomData }, Global)
+            Box(
+                Unique {
+                    pointer: NonNull(intrinsics::transmute::<
+                        *mut u8,
+                        pattern_type!(*const T is !null),
+                    >(ptr)),
+                    _marker: PhantomData,
+                },
+                Global,
+            )
         }
     }
 }
@@ -608,7 +656,9 @@ impl<T: ?Sized, A> Drop for Box<T, A> {
     fn drop(&mut self) {
         // inner value is dropped by compiler
         unsafe {
-            libc::free(self.0.pointer.0 as *mut u8);
+            libc::free(intrinsics::transmute::<pattern_type!(*const T is !null), *const T>(
+                self.0.pointer.0,
+            ) as *mut u8);
         }
     }
 }

example/mini_core_hello_world.rs

@@ -1,4 +1,13 @@
-#![feature(no_core, lang_items, never_type, extern_types, thread_local, repr_simd, rustc_private)]
+#![feature(
+    no_core,
+    lang_items,
+    never_type,
+    extern_types,
+    thread_local,
+    repr_simd,
+    pattern_types,
+    rustc_private
+)]
 #![cfg_attr(not(any(jit, target_vendor = "apple", windows)), feature(linkage))]
 #![no_core]
 #![allow(dead_code, non_camel_case_types, internal_features)]
@@ -153,7 +162,10 @@ extern "C" fn bool_struct_in_11(_arg0: bool_11) {}
 
 #[allow(unreachable_code)] // FIXME false positive
 fn main() {
-    take_unique(Unique { pointer: unsafe { NonNull(1 as *mut ()) }, _marker: PhantomData });
+    take_unique(Unique {
+        pointer: unsafe { NonNull(intrinsics::transmute(1 as *mut ())) },
+        _marker: PhantomData,
+    });
     take_f32(0.1);
 
     call_return_u128_pair();
@@ -219,7 +231,12 @@ fn main() {
         let noisy_unsized_drop = const { intrinsics::needs_drop::<NoisyDropUnsized>() };
         assert!(noisy_unsized_drop);
 
-        Unique { pointer: NonNull(1 as *mut &str), _marker: PhantomData } as Unique<dyn SomeTrait>;
+        Unique {
+            pointer: NonNull(intrinsics::transmute::<_, pattern_type!(*const &str is !null)>(
+                1 as *mut &str,
+            )),
+            _marker: PhantomData,
+        } as Unique<dyn SomeTrait>;
 
         struct MyDst<T: ?Sized>(T);
 

src/abi/pass_mode.rs

@@ -26,7 +26,9 @@ fn reg_to_abi_param(reg: Reg) -> AbiParam {
         (RegKind::Float, 4) => types::F32,
         (RegKind::Float, 8) => types::F64,
         (RegKind::Float, 16) => types::F128,
-        (RegKind::Vector, size) => types::I8.by(u32::try_from(size).unwrap()).unwrap(),
+        (RegKind::Vector { hint_vector_elem: _ }, size) => {
+            types::I8.by(u32::try_from(size).unwrap()).unwrap()
+        }
         _ => unreachable!("{:?}", reg),
     };
     AbiParam::new(clif_ty)

src/driver/aot.rs

@@ -380,11 +380,9 @@ fn codegen_cgu_content(
 
 fn module_codegen(
     tcx: TyCtxt<'_>,
-    (global_asm_config, cgu_name, token): (
-        Arc<GlobalAsmConfig>,
-        rustc_span::Symbol,
-        ConcurrencyLimiterToken,
-    ),
+    global_asm_config: Arc<GlobalAsmConfig>,
+    cgu_name: rustc_span::Symbol,
+    token: ConcurrencyLimiterToken,
 ) -> OngoingModuleCodegen {
     let mut module = make_module(tcx.sess, cgu_name.as_str().to_string());
 
@@ -513,8 +511,14 @@ pub(crate) fn run_aot(tcx: TyCtxt<'_>) -> Box<OngoingCodegen> {
                 let (module, _) = tcx.dep_graph.with_task(
                     dep_node,
                     tcx,
-                    (global_asm_config.clone(), cgu.name(), concurrency_limiter.acquire(tcx.dcx())),
-                    module_codegen,
+                    || {
+                        module_codegen(
+                            tcx,
+                            global_asm_config.clone(),
+                            cgu.name(),
+                            concurrency_limiter.acquire(tcx.dcx()),
+                        )
+                    },
                     Some(rustc_middle::dep_graph::hash_result),
                 );
                 IntoDynSyncSend(module)