Rollup merge of #104710 - RalfJung:doc-strict-provenance, r=thomcc

disable strict-provenance-violating doctests in Miri

Most of these are on deprecated unstable functions anyway. This lets us run the remaining doctests with `-Zmiri-strict-provenance`, which I think is a win.

r? `@thomcc`

Author: Dylan-DPC

library/core/src/primitive_docs.rs

@@ -1493,11 +1493,13 @@ mod prim_ref {}
 /// However, a direct cast back is not possible. You need to use `transmute`:
 ///
 /// ```rust
+/// # #[cfg(not(miri))] { // FIXME: use strict provenance APIs once they are stable, then remove this `cfg`
 /// # let fnptr: fn(i32) -> i32 = |x| x+2;
 /// # let fnptr_addr = fnptr as usize;
 /// let fnptr = fnptr_addr as *const ();
 /// let fnptr: fn(i32) -> i32 = unsafe { std::mem::transmute(fnptr) };
 /// assert_eq!(fnptr(40), 42);
+/// # }
 /// ```
 ///
 /// Crucially, we `as`-cast to a raw pointer before `transmute`ing to a function pointer.

library/core/src/ptr/const_ptr.rs

@@ -112,11 +112,13 @@ impl<T: ?Sized> *const T {
     ///
     /// ```
     /// #![feature(ptr_to_from_bits)]
+    /// # #[cfg(not(miri))] { // doctest does not work with strict provenance
     /// let array = [13, 42];
     /// let p0: *const i32 = &array[0];
     /// assert_eq!(<*const _>::from_bits(p0.to_bits()), p0);
     /// let p1: *const i32 = &array[1];
     /// assert_eq!(p1.to_bits() - p0.to_bits(), 4);
+    /// # }
     /// ```
     #[unstable(feature = "ptr_to_from_bits", issue = "91126")]
     #[deprecated(
@@ -140,9 +142,11 @@ impl<T: ?Sized> *const T {
     ///
     /// ```
     /// #![feature(ptr_to_from_bits)]
+    /// # #[cfg(not(miri))] { // doctest does not work with strict provenance
     /// use std::ptr::NonNull;
     /// let dangling: *const u8 = NonNull::dangling().as_ptr();
     /// assert_eq!(<*const u8>::from_bits(1), dangling);
+    /// # }
     /// ```
     #[unstable(feature = "ptr_to_from_bits", issue = "91126")]
     #[deprecated(

library/core/src/ptr/mut_ptr.rs

@@ -117,12 +117,14 @@ impl<T: ?Sized> *mut T {
     ///
     /// ```
     /// #![feature(ptr_to_from_bits)]
+    /// # #[cfg(not(miri))] { // doctest does not work with strict provenance
     /// let mut array = [13, 42];
     /// let mut it = array.iter_mut();
     /// let p0: *mut i32 = it.next().unwrap();
     /// assert_eq!(<*mut _>::from_bits(p0.to_bits()), p0);
     /// let p1: *mut i32 = it.next().unwrap();
     /// assert_eq!(p1.to_bits() - p0.to_bits(), 4);
+    /// }
     /// ```
     #[unstable(feature = "ptr_to_from_bits", issue = "91126")]
     #[deprecated(
@@ -146,9 +148,11 @@ impl<T: ?Sized> *mut T {
     ///
     /// ```
     /// #![feature(ptr_to_from_bits)]
+    /// # #[cfg(not(miri))] { // doctest does not work with strict provenance
     /// use std::ptr::NonNull;
     /// let dangling: *mut u8 = NonNull::dangling().as_ptr();
     /// assert_eq!(<*mut u8>::from_bits(1), dangling);
+    /// }
     /// ```
     #[unstable(feature = "ptr_to_from_bits", issue = "91126")]
     #[deprecated(

library/std/src/primitive_docs.rs

@@ -1493,11 +1493,13 @@ mod prim_ref {}
 /// However, a direct cast back is not possible. You need to use `transmute`:
 ///
 /// ```rust
+/// # #[cfg(not(miri))] { // FIXME: use strict provenance APIs once they are stable, then remove this `cfg`
 /// # let fnptr: fn(i32) -> i32 = |x| x+2;
 /// # let fnptr_addr = fnptr as usize;
 /// let fnptr = fnptr_addr as *const ();
 /// let fnptr: fn(i32) -> i32 = unsafe { std::mem::transmute(fnptr) };
 /// assert_eq!(fnptr(40), 42);
+/// # }
 /// ```
 ///
 /// Crucially, we `as`-cast to a raw pointer before `transmute`ing to a function pointer.