Kernel: static vs non-static constexpr variables

Problem:
- `static` variables consume memory and sometimes are less
  optimizable.
- `static const` variables can be `constexpr`, usually.
- `static` function-local variables require an initialization check
  every time the function is run.

Solution:
- If a global `static` variable is only used in a single function then
  move it into the function and make it non-`static` and `constexpr`.
- Make all global `static` variables `constexpr` instead of `const`.
- Change function-local `static const[expr]` variables to be just
  `constexpr`.

2 files changed, 4 insertions, 4 deletions

diff --git a/Kernel/VM/MemoryManager.h b/Kernel/VM/MemoryManager.h
index cb6b860b17..0800428f27 100644
--- a/Kernel/VM/MemoryManager.h
+++ b/Kernel/VM/MemoryManager.h
@@ -54,7 +54,7 @@ enum class UsedMemoryRangeType {
     BootModule,
 };
 
-constexpr static const char* UserMemoryRangeTypeNames[] {
+static constexpr StringView UserMemoryRangeTypeNames[] {
     "Low memory",
     "Kernel",
     "Boot module",
diff --git a/Kernel/VM/PageDirectory.cpp b/Kernel/VM/PageDirectory.cpp
index b8bbbdbe9b..b6b5287b48 100644
--- a/Kernel/VM/PageDirectory.cpp
+++ b/Kernel/VM/PageDirectory.cpp
@@ -13,9 +13,6 @@
 
 namespace Kernel {
 
-static const FlatPtr userspace_range_base = 0x00800000;
-static const FlatPtr userspace_range_ceiling = 0xbe000000;
-
 static AK::Singleton<HashMap<u32, PageDirectory*>> s_cr3_map;
 
 static HashMap<u32, PageDirectory*>& cr3_map()
@@ -53,6 +50,9 @@ UNMAP_AFTER_INIT PageDirectory::PageDirectory()
 
 PageDirectory::PageDirectory(const RangeAllocator* parent_range_allocator)
 {
+    constexpr FlatPtr userspace_range_base = 0x00800000;
+    constexpr FlatPtr userspace_range_ceiling = 0xbe000000;
+
     ScopedSpinLock lock(s_mm_lock);
     if (parent_range_allocator) {
         m_range_allocator.initialize_from_parent(*parent_range_allocator);