Add missing Debug derives

Add free Debug derives plus a lint to prevent future issues.

Signed-off-by: Carlos López <[email protected]>

Author: 00xc

CHANGELOG.md

@@ -12,6 +12,8 @@
   for `Cursor<&mut [u8]>`.
 - [[#256](https://github.com/rust-vmm/vm-memory/pull/256)] Implement `ReadVolatile`
   for `Cursor<T: AsRef[u8]>`.
+- [[#266](https://github.com/rust-vmm/vm-memory/pull/266)] Derive `Debug` for several
+  types that were missing it.
 
 ## [v0.13.0]
 

src/atomic.rs

@@ -124,6 +124,7 @@ impl<M: GuestMemory> Deref for GuestMemoryLoadGuard<M> {
 /// this structure is dropped (falls out of scope) the lock will be unlocked,
 /// possibly after updating the memory map represented by the
 /// `GuestMemoryAtomic` that created the guard.
+#[derive(Debug)]
 pub struct GuestMemoryExclusiveGuard<'a, M: GuestMemory> {
     parent: &'a GuestMemoryAtomic<M>,
     _guard: MutexGuard<'a, ()>,

src/lib.rs

@@ -18,6 +18,7 @@
 
 #![deny(clippy::doc_markdown)]
 #![deny(missing_docs)]
+#![deny(missing_debug_implementations)]
 
 #[macro_use]
 pub mod address;

src/mmap.rs

@@ -616,6 +616,7 @@ impl<B: Bitmap> GuestMemoryMmap<B> {
 /// An iterator over the elements of `GuestMemoryMmap`.
 ///
 /// This struct is created by `GuestMemory::iter()`. See its documentation for more.
+#[derive(Debug)]
 pub struct Iter<'a, B>(std::slice::Iter<'a, Arc<GuestRegionMmap<B>>>);
 
 impl<'a, B> Iterator for Iter<'a, B> {

src/mmap_unix.rs

@@ -52,6 +52,7 @@ pub enum Error {
 pub type Result<T> = result::Result<T, Error>;
 
 /// A factory struct to build `MmapRegion` objects.
+#[derive(Debug)]
 pub struct MmapRegionBuilder<B = ()> {
     size: usize,
     prot: i32,

src/volatile_memory.rs

@@ -302,6 +302,7 @@ impl<'a> From<&'a mut [u8]> for VolatileSlice<'a, ()> {
 struct Packed<T>(T);
 
 /// A guard to perform mapping and protect unmapping of the memory.
+#[derive(Debug)]
 pub struct PtrGuard {
     addr: *mut u8,
     len: usize,
@@ -347,6 +348,7 @@ impl PtrGuard {
 }
 
 /// A mutable guard to perform mapping and protect unmapping of the memory.
+#[derive(Debug)]
 pub struct PtrGuardMut(PtrGuard);
 
 #[allow(clippy::len_without_is_empty)]