redact coerced type away

compiler/rustc_codegen_cranelift/example/mini_core.rs

@@ -29,6 +29,13 @@ pub trait Unsize<T: ?Sized> {}
 #[lang = "coerce_unsized"]
 pub trait CoerceUnsized<T> {}
 
+#[lang = "coerce_pointee_validated"]
+pub trait CoercePointeeValidated {
+    /* compiler built-in */
+    #[lang = "coerce_pointee_validated_pointee"]
+    type Pointee: ?Sized;
+}
+
 impl<'a, 'b: 'a, T: ?Sized + Unsize<U>, U: ?Sized> CoerceUnsized<&'a U> for &'b T {}
 impl<'a, T: ?Sized + Unsize<U>, U: ?Sized> CoerceUnsized<&'a mut U> for &'a mut T {}
 impl<T: ?Sized + Unsize<U>, U: ?Sized> CoerceUnsized<*const U> for *const T {}

compiler/rustc_codegen_gcc/example/mini_core.rs

@@ -1,6 +1,14 @@
 #![feature(
-    no_core, lang_items, intrinsics, unboxed_closures, extern_types,
-    decl_macro, rustc_attrs, transparent_unions, auto_traits, freeze_impls,
+    no_core,
+    lang_items,
+    intrinsics,
+    unboxed_closures,
+    extern_types,
+    decl_macro,
+    rustc_attrs,
+    transparent_unions,
+    auto_traits,
+    freeze_impls,
     thread_local
 )]
 #![no_core]
@@ -26,6 +34,13 @@ pub trait Unsize<T: ?Sized> {}
 #[lang = "coerce_unsized"]
 pub trait CoerceUnsized<T> {}
 
+#[lang = "coerce_pointee_validated"]
+pub trait CoercePointeeValidated {
+    /* compiler built-in */
+    #[lang = "coerce_pointee_validated_pointee"]
+    type Pointee: ?Sized;
+}
+
 impl<'a, 'b: 'a, T: ?Sized + Unsize<U>, U: ?Sized> CoerceUnsized<&'a U> for &'b T {}
 impl<'a, T: ?Sized + Unsize<U>, U: ?Sized> CoerceUnsized<&'a mut U> for &'a mut T {}
 impl<T: ?Sized + Unsize<U>, U: ?Sized> CoerceUnsized<*const U> for *const T {}
@@ -35,13 +50,13 @@ impl<T: ?Sized + Unsize<U>, U: ?Sized> CoerceUnsized<*mut U> for *mut T {}
 pub trait DispatchFromDyn<T> {}
 
 // &T -> &U
-impl<'a, T: ?Sized+Unsize<U>, U: ?Sized> DispatchFromDyn<&'a U> for &'a T {}
+impl<'a, T: ?Sized + Unsize<U>, U: ?Sized> DispatchFromDyn<&'a U> for &'a T {}
 // &mut T -> &mut U
-impl<'a, T: ?Sized+Unsize<U>, U: ?Sized> DispatchFromDyn<&'a mut U> for &'a mut T {}
+impl<'a, T: ?Sized + Unsize<U>, U: ?Sized> DispatchFromDyn<&'a mut U> for &'a mut T {}
 // *const T -> *const U
-impl<T: ?Sized+Unsize<U>, U: ?Sized> DispatchFromDyn<*const U> for *const T {}
+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<*mut U> for *mut T {}
 impl<T: ?Sized + Unsize<U>, U: ?Sized> DispatchFromDyn<Box<U, ()>> for Box<T, ()> {}
 
 #[lang = "legacy_receiver"]
@@ -289,7 +304,6 @@ impl PartialEq for u32 {
     }
 }
 
-
 impl PartialEq for u64 {
     fn eq(&self, other: &u64) -> bool {
         (*self) == (*other)
@@ -476,7 +490,11 @@ fn panic_in_cleanup() -> ! {
 #[track_caller]
 fn panic_bounds_check(index: usize, len: usize) -> ! {
     unsafe {
-        libc::printf("index out of bounds: the len is %d but the index is %d\n\0" as *const str as *const i8, len, index);
+        libc::printf(
+            "index out of bounds: the len is %d but the index is %d\n\0" as *const str as *const i8,
+            len,
+            index,
+        );
         intrinsics::abort();
     }
 }
@@ -504,8 +522,7 @@ pub trait Deref {
     fn deref(&self) -> &Self::Target;
 }
 
-pub trait Allocator {
-}
+pub trait Allocator {}
 
 impl Allocator for () {}
 
@@ -699,19 +716,27 @@ pub struct VaList<'a>(&'a mut VaListImpl);
 
 #[rustc_builtin_macro]
 #[rustc_macro_transparency = "semitransparent"]
-pub macro stringify($($t:tt)*) { /* compiler built-in */ }
+pub macro stringify($($t:tt)*) {
+    /* compiler built-in */
+}
 
 #[rustc_builtin_macro]
 #[rustc_macro_transparency = "semitransparent"]
-pub macro file() { /* compiler built-in */ }
+pub macro file() {
+    /* compiler built-in */
+}
 
 #[rustc_builtin_macro]
 #[rustc_macro_transparency = "semitransparent"]
-pub macro line() { /* compiler built-in */ }
+pub macro line() {
+    /* compiler built-in */
+}
 
 #[rustc_builtin_macro]
 #[rustc_macro_transparency = "semitransparent"]
-pub macro cfg() { /* compiler built-in */ }
+pub macro cfg() {
+    /* compiler built-in */
+}
 
 pub static A_STATIC: u8 = 42;
 

compiler/rustc_hir_analysis/messages.ftl

@@ -85,6 +85,11 @@ hir_analysis_cmse_output_stack_spill =
     .note1 = functions with the `"{$abi_name}"` ABI must pass their result via the available return registers
     .note2 = the result must either be a (transparently wrapped) i64, u64 or f64, or be at most 4 bytes in size
 
+hir_analysis_coerce_pointee_multiple_targets = `derive(CoercePointee)` only admits exactly one data field, {$diag_trait ->
+    [DispatchFromDyn] to which `dyn` methods shall be dispatched
+    *[CoerceUnsized] on which unsize coercion shall be performed
+    }
+
 hir_analysis_coerce_pointee_no_field = `CoercePointee` can only be derived on `struct`s with at least one field
 
 hir_analysis_coerce_pointee_no_user_validity_assertion = asserting applicability of `derive(CoercePointee)` on a target data is forbidden