Implement precrement instead

4 files changed, 7 insertions, 11 deletions

diff --git a/arch/x86_64/include/arch/memory/paging/page_mapper.hpp b/arch/x86_64/include/arch/memory/paging/page_mapper.hpp
index 173db9b..a2d076a 100644
--- a/arch/x86_64/include/arch/memory/paging/page_mapper.hpp
+++ b/arch/x86_64/include/arch/memory/paging/page_mapper.hpp
@@ -63,7 +63,7 @@ namespace teachos::arch::memory::paging
   {
     auto current_handle = create_or_get();
 
-    for (auto level = page_table_handle::LEVEL4; level != page_table_handle::LEVEL1; level--)
+    for (auto level = page_table_handle::LEVEL4; level != page_table_handle::LEVEL1; --level)
     {
       auto level_index = page.get_level_index(level);
       auto next_handle = current_handle.next_table(level_index);
@@ -136,7 +136,7 @@ namespace teachos::arch::memory::paging
 
     auto current_handle = create_or_get();
 
-    for (auto level = page_table_handle::LEVEL4; level != page_table_handle::LEVEL1; level--)
+    for (auto level = page_table_handle::LEVEL4; level != page_table_handle::LEVEL1; --level)
     {
       auto level_index = page.get_level_index(level);
       auto next_handle = current_handle.next_table(level_index);
diff --git a/arch/x86_64/include/arch/memory/paging/page_table.hpp b/arch/x86_64/include/arch/memory/paging/page_table.hpp
index e6542a2..1fd6f61 100644
--- a/arch/x86_64/include/arch/memory/paging/page_table.hpp
+++ b/arch/x86_64/include/arch/memory/paging/page_table.hpp
@@ -83,7 +83,7 @@ namespace teachos::arch::memory::paging
      * @param value Value we want to decrement on
      * @return level New level value decrement by one, meaning the level is also decrement by one Level4 --> Level3, ...
      */
-    friend auto operator--(level & value, int) -> level;
+    friend auto operator--(level & value) -> level &;
 
   private:
     page_table * handle;  ///< Handle to underlying page table, can never be null (invariant ensured by constructor)
diff --git a/arch/x86_64/src/memory/paging/page_mapper.cpp b/arch/x86_64/src/memory/paging/page_mapper.cpp
index 03f9f10..e9c6766 100644
--- a/arch/x86_64/src/memory/paging/page_mapper.cpp
+++ b/arch/x86_64/src/memory/paging/page_mapper.cpp
@@ -20,7 +20,7 @@ namespace teachos::arch::memory::paging
   {
     auto current_handle = create_or_get();
 
-    for (auto level = page_table_handle::LEVEL4; level != page_table_handle::LEVEL1; level--)
+    for (auto level = page_table_handle::LEVEL4; level != page_table_handle::LEVEL1; --level)
     {
       auto next_handle = current_handle.next_table(page.get_level_index(level));
       // If the next table method failed then it is highly likely that it was a huge page and we therefore have to
diff --git a/arch/x86_64/src/memory/paging/page_table.cpp b/arch/x86_64/src/memory/paging/page_table.cpp
index b229ff7..c735a62 100644
--- a/arch/x86_64/src/memory/paging/page_table.cpp
+++ b/arch/x86_64/src/memory/paging/page_table.cpp
@@ -106,23 +106,19 @@ namespace teachos::arch::memory::paging
     auto next_table = handle->next_table(table_index);
     if (next_table)
     {
-      handle_level--;
-      return page_table_handle{next_table.value(), handle_level};
+      return page_table_handle{next_table.value(), --handle_level};
     }
     return std::nullopt;
   }
 
   auto page_table_handle::operator[](std::size_t index) const -> entry { return handle->operator[](index); }
 
-  auto operator--(page_table_handle::level & value, int) -> page_table_handle::level
+  auto operator--(page_table_handle::level & value) -> page_table_handle::level &
   {
     exception_handling::assert(value != page_table_handle::LEVEL1,
                                "[Page table] Attempted to decrement enum to value outside of range");
-
-    page_table_handle::level original_value = value;
     auto new_value = static_cast<std::underlying_type<page_table_handle::level>::type>(value);
     value = static_cast<page_table_handle::level>(--new_value);
-
-    return original_value;
+    return value;
   }
 }  // namespace teachos::arch::memory::paging