Auto merge of #125691 - jieyouxu:rollup-0i3wrc4, r=jieyouxu

Rollup of 8 pull requests

Successful merges:

 - #124251 (Add an intrinsic for `ptr::metadata`)
 - #124320 (Add `--print=check-cfg` to get the expected configs)
 - #125226 (Make more of the test suite run on Mac Catalyst)
 - #125381 (Silence some resolve errors when there have been glob import errors)
 - #125633 (miri: avoid making a full copy of all new allocations)
 - #125638 (Rewrite `lto-smoke`, `simple-rlib` and `mixing-deps` `run-make` tests in `rmake.rs` format)
 - #125639 (Support `./x doc run-make-support --open`)
 - #125664 (Tweak relations to no longer rely on `TypeTrace`)

r? `@ghost`
`@rustbot` modify labels: rollup

3 files changed, 36 insertions, 4 deletions

diff --git a/library/core/src/intrinsics.rs b/library/core/src/intrinsics.rs
index 5a2a4c5ae6e..89e0b670995 100644
--- a/library/core/src/intrinsics.rs
+++ b/library/core/src/intrinsics.rs
@@ -2821,6 +2821,21 @@ impl<P: ?Sized, T: ptr::Thin> AggregateRawPtr<*mut T> for *mut P {
     type Metadata = <P as ptr::Pointee>::Metadata;
 }
 
+/// Lowers in MIR to `Rvalue::UnaryOp` with `UnOp::PtrMetadata`.
+///
+/// This is used to implement functions like `ptr::metadata`.
+#[rustc_nounwind]
+#[unstable(feature = "core_intrinsics", issue = "none")]
+#[rustc_const_unstable(feature = "ptr_metadata", issue = "81513")]
+#[rustc_intrinsic]
+#[rustc_intrinsic_must_be_overridden]
+#[cfg(not(bootstrap))]
+pub const fn ptr_metadata<P: ptr::Pointee<Metadata = M> + ?Sized, M>(_ptr: *const P) -> M {
+    // To implement a fallback we'd have to assume the layout of the pointer,
+    // but the whole point of this intrinsic is that we shouldn't do that.
+    unreachable!()
+}
+
 // Some functions are defined here because they accidentally got made
 // available in this module on stable. See <https://github.com/rust-lang/rust/issues/15702>.
 // (`transmute` also falls into this category, but it cannot be wrapped due to the
diff --git a/library/core/src/intrinsics/mir.rs b/library/core/src/intrinsics/mir.rs
index 02665b2676c..fa5bb28adff 100644
--- a/library/core/src/intrinsics/mir.rs
+++ b/library/core/src/intrinsics/mir.rs
@@ -360,6 +360,10 @@ define!("mir_assume", fn Assume(operand: bool));
 define!("mir_deinit", fn Deinit<T>(place: T));
 define!("mir_checked", fn Checked<T>(binop: T) -> (T, bool));
 define!("mir_len", fn Len<T>(place: T) -> usize);
+define!(
+    "mir_ptr_metadata",
+    fn PtrMetadata<P: ?Sized>(place: *const P) -> <P as ::core::ptr::Pointee>::Metadata
+);
 define!("mir_copy_for_deref", fn CopyForDeref<T>(place: T) -> T);
 define!("mir_retag", fn Retag<T>(place: T));
 define!("mir_move", fn Move<T>(place: T) -> T);
diff --git a/library/core/src/ptr/metadata.rs b/library/core/src/ptr/metadata.rs
index 6dfeb66694d..8d75bd2e74c 100644
--- a/library/core/src/ptr/metadata.rs
+++ b/library/core/src/ptr/metadata.rs
@@ -3,6 +3,8 @@
 use crate::fmt;
 use crate::hash::{Hash, Hasher};
 use crate::intrinsics::aggregate_raw_ptr;
+#[cfg(not(bootstrap))]
+use crate::intrinsics::ptr_metadata;
 use crate::marker::Freeze;
 
 /// Provides the pointer metadata type of any pointed-to type.
@@ -94,10 +96,17 @@ pub trait Thin = Pointee<Metadata = ()>;
 #[rustc_const_unstable(feature = "ptr_metadata", issue = "81513")]
 #[inline]
 pub const fn metadata<T: ?Sized>(ptr: *const T) -> <T as Pointee>::Metadata {
-    // SAFETY: Accessing the value from the `PtrRepr` union is safe since *const T
-    // and PtrComponents<T> have the same memory layouts. Only std can make this
-    // guarantee.
-    unsafe { PtrRepr { const_ptr: ptr }.components.metadata }
+    #[cfg(bootstrap)]
+    {
+        // SAFETY: Accessing the value from the `PtrRepr` union is safe since *const T
+        // and PtrComponents<T> have the same memory layouts. Only std can make this
+        // guarantee.
+        unsafe { PtrRepr { const_ptr: ptr }.components.metadata }
+    }
+    #[cfg(not(bootstrap))]
+    {
+        ptr_metadata(ptr)
+    }
 }
 
 /// Forms a (possibly-wide) raw pointer from a data pointer and metadata.
@@ -132,6 +141,7 @@ pub const fn from_raw_parts_mut<T: ?Sized>(
 }
 
 #[repr(C)]
+#[cfg(bootstrap)]
 union PtrRepr<T: ?Sized> {
     const_ptr: *const T,
     mut_ptr: *mut T,
@@ -139,15 +149,18 @@ union PtrRepr<T: ?Sized> {
 }
 
 #[repr(C)]
+#[cfg(bootstrap)]
 struct PtrComponents<T: ?Sized> {
     data_pointer: *const (),
     metadata: <T as Pointee>::Metadata,
 }
 
 // Manual impl needed to avoid `T: Copy` bound.
+#[cfg(bootstrap)]
 impl<T: ?Sized> Copy for PtrComponents<T> {}
 
 // Manual impl needed to avoid `T: Clone` bound.
+#[cfg(bootstrap)]
 impl<T: ?Sized> Clone for PtrComponents<T> {
     fn clone(&self) -> Self {
         *self