code review: comment fixes

Author: Strophox

src/tools/miri/src/alloc_addresses/mod.rs

@@ -174,6 +174,8 @@ trait EvalContextExtPriv<'tcx>: crate::MiriInterpCxExt<'tcx> {
 
                 // This allocation does not have a base address yet, pick or reuse one.
                 let base_addr = if ecx.machine.native_lib.is_some() {
+                    // In native lib mode, we use the "real" address of the bytes for this allocation.
+                    // This ensures the interpreted program and native code have the same view of memory.
                     match kind {
                         AllocKind::LiveData => {
                             let ptr = if ecx.tcx.try_get_global_alloc(alloc_id).is_some() {
@@ -364,7 +366,7 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
             ecx.addr_from_alloc_id(id, kind)?;
             let mut global_state = ecx.machine.alloc_addresses.borrow_mut();
             // The memory we need here will have already been allocated during an earlier call to
-            // `global_root_pointer` for this allocation. So don't create a new `MiriAllocBytes` here, instead
+            // `addr_from_alloc_id` for this allocation. So don't create a new `MiriAllocBytes` here, instead
             // fetch the previously prepared bytes from `prepared_alloc_bytes`.
             let mut prepared_alloc_bytes = global_state
                 .prepared_alloc_bytes

src/tools/miri/src/machine.rs

@@ -1240,8 +1240,6 @@ impl<'tcx> Machine<'tcx> for MiriMachine<'tcx> {
         alloc: &'b Allocation,
     ) -> InterpResult<'tcx, Cow<'b, Allocation<Self::Provenance, Self::AllocExtra, Self::Bytes>>>
     {
-        // The default implementation does a copy; CTFE machines have a more efficient implementation
-        // based on their particular choice for `Provenance`, `AllocExtra`, and `Bytes`.
         let kind = Self::GLOBAL_KIND.unwrap().into();
         let alloc = alloc.adjust_from_tcx(&ecx.tcx,
             |bytes, align| ecx.get_global_alloc_bytes(id, kind, bytes, align),