Auto merge of rust-lang#121268 - Urgau:improve_ambi_wide_ptr_cmps, r=Nadrieril

Add detection of [Partial]Ord methods in the `ambiguous_wide_pointer_comparisons` lint

Partially addresses rust-lang#121264 by adding diagnostics items for PartialOrd and Ord methods, detecting such diagnostics items as "binary operation" and suggesting the correct replacement.

I also took the opportunity to change the suggestion to use new methods `.cast()` on `*mut T` an d `*const T`.

Author: bors

core/src/cmp.rs

@@ -848,6 +848,7 @@ pub trait Ord: Eq + PartialOrd<Self> {
     #[stable(feature = "ord_max_min", since = "1.21.0")]
     #[inline]
     #[must_use]
+    #[cfg_attr(not(bootstrap), rustc_diagnostic_item = "cmp_ord_max")]
     fn max(self, other: Self) -> Self
     where
         Self: Sized,
@@ -868,6 +869,7 @@ pub trait Ord: Eq + PartialOrd<Self> {
     #[stable(feature = "ord_max_min", since = "1.21.0")]
     #[inline]
     #[must_use]
+    #[cfg_attr(not(bootstrap), rustc_diagnostic_item = "cmp_ord_min")]
     fn min(self, other: Self) -> Self
     where
         Self: Sized,
@@ -1154,6 +1156,7 @@ pub trait PartialOrd<Rhs: ?Sized = Self>: PartialEq<Rhs> {
     /// ```
     #[must_use]
     #[stable(feature = "rust1", since = "1.0.0")]
+    #[cfg_attr(not(bootstrap), rustc_diagnostic_item = "cmp_partialord_cmp")]
     fn partial_cmp(&self, other: &Rhs) -> Option<Ordering>;
 
     /// This method tests less than (for `self` and `other`) and is used by the `<` operator.
@@ -1168,6 +1171,7 @@ pub trait PartialOrd<Rhs: ?Sized = Self>: PartialEq<Rhs> {
     #[inline]
     #[must_use]
     #[stable(feature = "rust1", since = "1.0.0")]
+    #[cfg_attr(not(bootstrap), rustc_diagnostic_item = "cmp_partialord_lt")]
     fn lt(&self, other: &Rhs) -> bool {
         matches!(self.partial_cmp(other), Some(Less))
     }
@@ -1185,6 +1189,7 @@ pub trait PartialOrd<Rhs: ?Sized = Self>: PartialEq<Rhs> {
     #[inline]
     #[must_use]
     #[stable(feature = "rust1", since = "1.0.0")]
+    #[cfg_attr(not(bootstrap), rustc_diagnostic_item = "cmp_partialord_le")]
     fn le(&self, other: &Rhs) -> bool {
         matches!(self.partial_cmp(other), Some(Less | Equal))
     }
@@ -1201,6 +1206,7 @@ pub trait PartialOrd<Rhs: ?Sized = Self>: PartialEq<Rhs> {
     #[inline]
     #[must_use]
     #[stable(feature = "rust1", since = "1.0.0")]
+    #[cfg_attr(not(bootstrap), rustc_diagnostic_item = "cmp_partialord_gt")]
     fn gt(&self, other: &Rhs) -> bool {
         matches!(self.partial_cmp(other), Some(Greater))
     }
@@ -1218,6 +1224,7 @@ pub trait PartialOrd<Rhs: ?Sized = Self>: PartialEq<Rhs> {
     #[inline]
     #[must_use]
     #[stable(feature = "rust1", since = "1.0.0")]
+    #[cfg_attr(not(bootstrap), rustc_diagnostic_item = "cmp_partialord_ge")]
     fn ge(&self, other: &Rhs) -> bool {
         matches!(self.partial_cmp(other), Some(Greater | Equal))
     }

core/src/ptr/const_ptr.rs

@@ -1857,6 +1857,7 @@ impl<T: ?Sized> Ord for *const T {
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<T: ?Sized> PartialOrd for *const T {
     #[inline]
+    #[allow(ambiguous_wide_pointer_comparisons)]
     fn partial_cmp(&self, other: &*const T) -> Option<Ordering> {
         Some(self.cmp(other))
     }

core/src/ptr/metadata.rs

@@ -258,6 +258,7 @@ impl<Dyn: ?Sized> PartialEq for DynMetadata<Dyn> {
 
 impl<Dyn: ?Sized> Ord for DynMetadata<Dyn> {
     #[inline]
+    #[allow(ambiguous_wide_pointer_comparisons)]
     fn cmp(&self, other: &Self) -> crate::cmp::Ordering {
         (self.vtable_ptr as *const VTable).cmp(&(other.vtable_ptr as *const VTable))
     }

core/src/ptr/mut_ptr.rs

@@ -2275,6 +2275,7 @@ impl<T: ?Sized> Ord for *mut T {
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<T: ?Sized> PartialOrd for *mut T {
     #[inline(always)]
+    #[allow(ambiguous_wide_pointer_comparisons)]
     fn partial_cmp(&self, other: &*mut T) -> Option<Ordering> {
         Some(self.cmp(other))
     }

core/src/ptr/non_null.rs

@@ -1821,6 +1821,7 @@ impl<T: ?Sized> PartialEq for NonNull<T> {
 #[stable(feature = "nonnull", since = "1.25.0")]
 impl<T: ?Sized> Ord for NonNull<T> {
     #[inline]
+    #[allow(ambiguous_wide_pointer_comparisons)]
     fn cmp(&self, other: &Self) -> Ordering {
         self.as_ptr().cmp(&other.as_ptr())
     }
@@ -1829,6 +1830,7 @@ impl<T: ?Sized> Ord for NonNull<T> {
 #[stable(feature = "nonnull", since = "1.25.0")]
 impl<T: ?Sized> PartialOrd for NonNull<T> {
     #[inline]
+    #[allow(ambiguous_wide_pointer_comparisons)]
     fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
         self.as_ptr().partial_cmp(&other.as_ptr())
     }