implement ptr.addr() via transmute

RalfJung · RalfJung · commit 4291332175d1 · 2022-06-03T16:45:35.000-04:00
diff --git a/library/core/src/ptr/const_ptr.rs b/library/core/src/ptr/const_ptr.rs
@@ -180,7 +180,9 @@ impl<T: ?Sized> *const T {
         T: Sized,
     {
         // FIXME(strict_provenance_magic): I am magic and should be a compiler intrinsic.
-        self as usize
+        // SAFETY: Pointer-to-integer transmutes are valid (if you are okay with losing the
+        // provenance).
+        unsafe { mem::transmute(self) }
     }
 
     /// Gets the "address" portion of the pointer, and 'exposes' the "provenance" part for future
diff --git a/library/core/src/ptr/mut_ptr.rs b/library/core/src/ptr/mut_ptr.rs
@@ -184,7 +184,9 @@ impl<T: ?Sized> *mut T {
         T: Sized,
     {
         // FIXME(strict_provenance_magic): I am magic and should be a compiler intrinsic.
-        self as usize
+        // SAFETY: Pointer-to-integer transmutes are valid (if you are okay with losing the
+        // provenance).
+        unsafe { mem::transmute(self) }
     }
 
     /// Gets the "address" portion of the pointer, and 'exposes' the "provenance" part for future

Original file line number	Diff line number	Diff line change
`@@ -180,7 +180,9 @@ impl<T: ?Sized> *const T {`
`180`	`180`	`T: Sized,`
`181`	`181`	`{`
`182`	`182`	`// FIXME(strict_provenance_magic): I am magic and should be a compiler intrinsic.`
`183`		`- self as usize`
	`183`	`+ // SAFETY: Pointer-to-integer transmutes are valid (if you are okay with losing the`
	`184`	`+ // provenance).`
	`185`	`+ unsafe { mem::transmute(self) }`
`184`	`186`	`}`
`185`	`187`
`186`	`188`	`/// Gets the "address" portion of the pointer, and 'exposes' the "provenance" part for future`
Original file line number	Diff line number	Diff line change
`@@ -184,7 +184,9 @@ impl<T: ?Sized> *mut T {`
`184`	`184`	`T: Sized,`
`185`	`185`	`{`
`186`	`186`	`// FIXME(strict_provenance_magic): I am magic and should be a compiler intrinsic.`
`187`		`- self as usize`
	`187`	`+ // SAFETY: Pointer-to-integer transmutes are valid (if you are okay with losing the`
	`188`	`+ // provenance).`
	`189`	`+ unsafe { mem::transmute(self) }`
`188`	`190`	`}`
`189`	`191`
`190`	`192`	`/// Gets the "address" portion of the pointer, and 'exposes' the "provenance" part for future`