Move Sealed::DEBUG_STR to separate crate

Items from supertraits are accessible even if the trait is private. By using a separate trait we avoid that.

src/instructions/port.rs

@@ -4,8 +4,8 @@ use core::arch::asm;
 use core::fmt;
 use core::marker::PhantomData;
 
-use crate::sealed::Sealed;
 pub use crate::structures::port::{PortRead, PortWrite};
+use crate::{sealed::Sealed, DebugOutput};
 
 impl PortRead for u8 {
     #[inline]
@@ -80,7 +80,8 @@ pub trait PortWriteAccess: PortAccess {}
 #[derive(Debug)]
 pub struct ReadOnlyAccess(());
 
-impl Sealed for ReadOnlyAccess {
+impl Sealed for ReadOnlyAccess {}
+impl DebugOutput for ReadOnlyAccess {
     const DEBUG_STR: &'static str = "ReadOnly";
 }
 impl PortAccess for ReadOnlyAccess {}
@@ -90,7 +91,8 @@ impl PortReadAccess for ReadOnlyAccess {}
 #[derive(Debug)]
 pub struct WriteOnlyAccess(());
 
-impl Sealed for WriteOnlyAccess {
+impl Sealed for WriteOnlyAccess {}
+impl DebugOutput for WriteOnlyAccess {
     const DEBUG_STR: &'static str = "WriteOnly";
 }
 impl PortAccess for WriteOnlyAccess {}
@@ -100,7 +102,8 @@ impl PortWriteAccess for WriteOnlyAccess {}
 #[derive(Debug)]
 pub struct ReadWriteAccess(());
 
-impl Sealed for ReadWriteAccess {
+impl Sealed for ReadWriteAccess {}
+impl DebugOutput for ReadWriteAccess {
     const DEBUG_STR: &'static str = "ReadWrite";
 }
 impl PortAccess for ReadWriteAccess {}
@@ -166,7 +169,7 @@ impl<T: PortWrite, A: PortWriteAccess> PortGeneric<T, A> {
     }
 }
 
-impl<T, A: PortAccess> fmt::Debug for PortGeneric<T, A> {
+impl<T, A: PortAccess + DebugOutput> fmt::Debug for PortGeneric<T, A> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         f.debug_struct("PortGeneric")
             .field("port", &self.port)

src/instructions/tlb.rs

@@ -8,7 +8,7 @@ use crate::{
         page::{NotGiantPageSize, PageRange},
         Page, PageSize, Size2MiB, Size4KiB,
     },
-    PrivilegeLevel, VirtAddr,
+    DebugOutput, PrivilegeLevel, VirtAddr,
 };
 use core::{arch::asm, cmp, convert::TryFrom, fmt};
 
@@ -220,7 +220,7 @@ impl Invlpgb {
 #[must_use]
 pub struct InvlpgbFlushBuilder<'a, S = Size4KiB>
 where
-    S: NotGiantPageSize,
+    S: NotGiantPageSize + DebugOutput,
 {
     invlpgb: &'a Invlpgb,
     page_range: Option<PageRange<S>>,
@@ -233,15 +233,15 @@ where
 
 impl<'a, S> InvlpgbFlushBuilder<'a, S>
 where
-    S: NotGiantPageSize,
+    S: NotGiantPageSize + DebugOutput,
 {
     /// Flush a range of pages.
     ///
     /// If the range doesn't fit within `invlpgb_count_max`, `invlpgb` is
     /// executed multiple times.
     pub fn pages<T>(self, page_range: PageRange<T>) -> InvlpgbFlushBuilder<'a, T>
     where
-        T: NotGiantPageSize,
+        T: NotGiantPageSize + DebugOutput,
     {
         InvlpgbFlushBuilder {
             invlpgb: self.invlpgb,

src/lib.rs

@@ -65,8 +65,10 @@ impl PrivilegeLevel {
 }
 
 pub(crate) mod sealed {
-    pub trait Sealed {
-        /// A string representation for debug output.
-        const DEBUG_STR: &'static str;
-    }
+    pub trait Sealed {}
+}
+
+trait DebugOutput {
+    /// A string representation for debug output.
+    const DEBUG_STR: &'static str;
 }

src/structures/paging/frame.rs

@@ -2,7 +2,7 @@
 
 use super::page::AddressNotAligned;
 use crate::structures::paging::page::{PageSize, Size4KiB};
-use crate::PhysAddr;
+use crate::{DebugOutput, PhysAddr};
 use core::fmt;
 use core::marker::PhantomData;
 use core::ops::{Add, AddAssign, Sub, SubAssign};
@@ -82,7 +82,7 @@ impl<S: PageSize> PhysFrame<S> {
     }
 }
 
-impl<S: PageSize> fmt::Debug for PhysFrame<S> {
+impl<S: PageSize + DebugOutput> fmt::Debug for PhysFrame<S> {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         f.write_fmt(format_args!(
             "PhysFrame[{}]({:#x})",
@@ -163,7 +163,7 @@ impl<S: PageSize> Iterator for PhysFrameRange<S> {
     }
 }
 
-impl<S: PageSize> fmt::Debug for PhysFrameRange<S> {
+impl<S: PageSize + DebugOutput> fmt::Debug for PhysFrameRange<S> {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         f.debug_struct("PhysFrameRange")
             .field("start", &self.start)
@@ -205,7 +205,7 @@ impl<S: PageSize> Iterator for PhysFrameRangeInclusive<S> {
     }
 }
 
-impl<S: PageSize> fmt::Debug for PhysFrameRangeInclusive<S> {
+impl<S: PageSize + DebugOutput> fmt::Debug for PhysFrameRangeInclusive<S> {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         f.debug_struct("PhysFrameRangeInclusive")
             .field("start", &self.start)

src/structures/paging/mapper/mod.rs

@@ -6,11 +6,14 @@ pub use self::offset_page_table::OffsetPageTable;
 #[cfg(feature = "instructions")]
 pub use self::recursive_page_table::{InvalidPageTable, RecursivePageTable};
 
-use crate::structures::paging::{
-    frame_alloc::{FrameAllocator, FrameDeallocator},
-    page::PageRangeInclusive,
-    page_table::PageTableFlags,
-    Page, PageSize, PhysFrame, Size1GiB, Size2MiB, Size4KiB,
+use crate::{
+    structures::paging::{
+        frame_alloc::{FrameAllocator, FrameDeallocator},
+        page::PageRangeInclusive,
+        page_table::PageTableFlags,
+        Page, PageSize, PhysFrame, Size1GiB, Size2MiB, Size4KiB,
+    },
+    DebugOutput,
 };
 use crate::{PhysAddr, VirtAddr};
 
@@ -107,7 +110,7 @@ impl MappedFrame {
 }
 
 /// A trait for common page table operations on pages of size `S`.
-pub trait Mapper<S: PageSize> {
+pub trait Mapper<S: PageSize + DebugOutput> {
     /// Creates a new mapping in the page table.
     ///
     /// This function might need additional physical frames to create new page tables. These
@@ -383,9 +386,9 @@ pub trait Mapper<S: PageSize> {
 /// changed the mapping of a page to ensure that the TLB flush is not forgotten.
 #[derive(Debug)]
 #[must_use = "Page Table changes must be flushed or ignored."]
-pub struct MapperFlush<S: PageSize>(Page<S>);
+pub struct MapperFlush<S: PageSize + DebugOutput>(Page<S>);
 
-impl<S: PageSize> MapperFlush<S> {
+impl<S: PageSize + DebugOutput> MapperFlush<S> {
     /// Create a new flush promise
     ///
     /// Note that this method is intended for implementing the [`Mapper`] trait and no other uses
@@ -440,7 +443,7 @@ impl MapperFlushAll {
 
 /// This error is returned from `map_to` and similar methods.
 #[derive(Debug)]
-pub enum MapToError<S: PageSize> {
+pub enum MapToError<S: PageSize + DebugOutput> {
     /// An additional frame was needed for the mapping process, but the frame allocator
     /// returned `None`.
     FrameAllocationFailed,

src/structures/paging/mapper/recursive_page_table.rs

@@ -116,7 +116,7 @@ impl<'a> RecursivePageTable<'a> {
     /// Returns `MapToError::FrameAllocationFailed` if the entry is unused and the allocator
     /// returned `None`. Returns `MapToError::ParentEntryHugePage` if the `HUGE_PAGE` flag is set
     /// in the passed entry.
-    unsafe fn create_next_table<'b, A, S: PageSize>(
+    unsafe fn create_next_table<'b, A, S: PageSize + DebugOutput>(
         entry: &'b mut PageTableEntry,
         next_table_page: Page,
         insert_flags: PageTableFlags,
@@ -128,7 +128,7 @@ impl<'a> RecursivePageTable<'a> {
         /// This inner function is used to limit the scope of `unsafe`.
         ///
         /// This is a safe function, so we need to use `unsafe` blocks when we do something unsafe.
-        fn inner<'b, A, S: PageSize>(
+        fn inner<'b, A, S: PageSize + DebugOutput>(
             entry: &'b mut PageTableEntry,
             next_table_page: Page,
             insert_flags: PageTableFlags,

src/structures/paging/page.rs

@@ -3,7 +3,7 @@
 use crate::sealed::Sealed;
 use crate::structures::paging::page_table::PageTableLevel;
 use crate::structures::paging::PageTableIndex;
-use crate::VirtAddr;
+use crate::{DebugOutput, VirtAddr};
 use core::fmt;
 #[cfg(feature = "step_trait")]
 use core::iter::Step;
@@ -39,7 +39,9 @@ impl PageSize for Size4KiB {
 
 impl NotGiantPageSize for Size4KiB {}
 
-impl Sealed for super::Size4KiB {
+impl Sealed for super::Size4KiB {}
+
+impl DebugOutput for super::Size4KiB {
     const DEBUG_STR: &'static str = "4KiB";
 }
 
@@ -49,15 +51,19 @@ impl PageSize for Size2MiB {
 
 impl NotGiantPageSize for Size2MiB {}
 
-impl Sealed for super::Size2MiB {
+impl Sealed for super::Size2MiB {}
+
+impl DebugOutput for super::Size2MiB {
     const DEBUG_STR: &'static str = "2MiB";
 }
 
 impl PageSize for Size1GiB {
     const SIZE: u64 = Size2MiB::SIZE * 512;
 }
 
-impl Sealed for super::Size1GiB {
+impl Sealed for super::Size1GiB {}
+
+impl DebugOutput for super::Size1GiB {
     const DEBUG_STR: &'static str = "1GiB";
 }
 
@@ -241,7 +247,7 @@ impl Page<Size4KiB> {
     }
 }
 
-impl<S: PageSize> fmt::Debug for Page<S> {
+impl<S: PageSize + DebugOutput> fmt::Debug for Page<S> {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         f.write_fmt(format_args!(
             "Page[{}]({:#x})",
@@ -353,7 +359,7 @@ impl PageRange<Size2MiB> {
     }
 }
 
-impl<S: PageSize> fmt::Debug for PageRange<S> {
+impl<S: PageSize + DebugOutput> fmt::Debug for PageRange<S> {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         f.debug_struct("PageRange")
             .field("start", &self.start)
@@ -404,7 +410,7 @@ impl<S: PageSize> Iterator for PageRangeInclusive<S> {
     }
 }
 
-impl<S: PageSize> fmt::Debug for PageRangeInclusive<S> {
+impl<S: PageSize + DebugOutput> fmt::Debug for PageRangeInclusive<S> {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         f.debug_struct("PageRangeInclusive")
             .field("start", &self.start)