Rollup merge of #104976 - WaffleLapkin:move_comments, r=cjgillot

Prefer doc comments over `//`-comments in compiler

Doc comments are generally nicer: they show up in the documentation, they are shown in IDEs when you hover other mentions of items, etc. Thus it makes sense to use them instead of `//`-comments.

2 files changed, 31 insertions, 32 deletions

diff --git a/compiler/rustc_mir_transform/src/add_moves_for_packed_drops.rs b/compiler/rustc_mir_transform/src/add_moves_for_packed_drops.rs
index ffb5d8c6d95..9b2260f6825 100644
--- a/compiler/rustc_mir_transform/src/add_moves_for_packed_drops.rs
+++ b/compiler/rustc_mir_transform/src/add_moves_for_packed_drops.rs
@@ -5,37 +5,36 @@ use crate::util;
 use crate::MirPass;
 use rustc_middle::mir::patch::MirPatch;
 
-// This pass moves values being dropped that are within a packed
-// struct to a separate local before dropping them, to ensure that
-// they are dropped from an aligned address.
-//
-// For example, if we have something like
-// ```Rust
-//     #[repr(packed)]
-//     struct Foo {
-//         dealign: u8,
-//         data: Vec<u8>
-//     }
-//
-//     let foo = ...;
-// ```
-//
-// We want to call `drop_in_place::<Vec<u8>>` on `data` from an aligned
-// address. This means we can't simply drop `foo.data` directly, because
-// its address is not aligned.
-//
-// Instead, we move `foo.data` to a local and drop that:
-// ```
-//     storage.live(drop_temp)
-//     drop_temp = foo.data;
-//     drop(drop_temp) -> next
-// next:
-//     storage.dead(drop_temp)
-// ```
-//
-// The storage instructions are required to avoid stack space
-// blowup.
-
+/// This pass moves values being dropped that are within a packed
+/// struct to a separate local before dropping them, to ensure that
+/// they are dropped from an aligned address.
+///
+/// For example, if we have something like
+/// ```ignore (ilustrative)
+/// #[repr(packed)]
+/// struct Foo {
+///     dealign: u8,
+///     data: Vec<u8>
+/// }
+///
+/// let foo = ...;
+/// ```
+///
+/// We want to call `drop_in_place::<Vec<u8>>` on `data` from an aligned
+/// address. This means we can't simply drop `foo.data` directly, because
+/// its address is not aligned.
+///
+/// Instead, we move `foo.data` to a local and drop that:
+/// ```ignore (ilustrative)
+///     storage.live(drop_temp)
+///     drop_temp = foo.data;
+///     drop(drop_temp) -> next
+/// next:
+///     storage.dead(drop_temp)
+/// ```
+///
+/// The storage instructions are required to avoid stack space
+/// blowup.
 pub struct AddMovesForPackedDrops;
 
 impl<'tcx> MirPass<'tcx> for AddMovesForPackedDrops {
diff --git a/compiler/rustc_mir_transform/src/elaborate_box_derefs.rs b/compiler/rustc_mir_transform/src/elaborate_box_derefs.rs
index ef8d6bb6559..932134bd631 100644
--- a/compiler/rustc_mir_transform/src/elaborate_box_derefs.rs
+++ b/compiler/rustc_mir_transform/src/elaborate_box_derefs.rs
@@ -25,7 +25,7 @@ pub fn build_ptr_tys<'tcx>(
     (unique_ty, nonnull_ty, ptr_ty)
 }
 
-// Constructs the projection needed to access a Box's pointer
+/// Constructs the projection needed to access a Box's pointer
 pub fn build_projection<'tcx>(
     unique_ty: Ty<'tcx>,
     nonnull_ty: Ty<'tcx>,