Make status implementation more correct wrt type punning

5 files changed, 26 insertions, 18 deletions

diff --git a/asl/base/utility.hpp b/asl/base/utility.hpp
index 206a5b1..85c873d 100644
--- a/asl/base/utility.hpp
+++ b/asl/base/utility.hpp
@@ -35,6 +35,13 @@ template<typename T, typename U>
     return static_cast<return_type>(x);
 }
 
+template<typename T>
+[[nodiscard]] constexpr T* launder(T* ptr) noexcept // NOLINT
+    requires (!asl::is_func<T> && !asl::is_void<T>)
+{
+    return __builtin_launder(ptr);
+}
+
 } // namespace std
 
 namespace asl
diff --git a/asl/containers/buffer.hpp b/asl/containers/buffer.hpp
index c3d865f..f5ba975 100644
--- a/asl/containers/buffer.hpp
+++ b/asl/containers/buffer.hpp
@@ -110,7 +110,9 @@ private:
     constexpr void set_size_inline(isize_t new_size)
     {
         ASL_ASSERT(new_size >= 0 && new_size <= kInlineCapacity);
-        const size_t size_encoded = (load_size_encoded() & size_t{0x00ff'ffff'ffff'ffff}) | (bit_cast<size_t>(new_size) << 56U);
+        const size_t size_encoded =
+            (load_size_encoded() & size_t{0x00ff'ffff'ffff'ffff})
+            | (bit_cast<size_t>(new_size) << 56U);
         store_size_encoded(size_encoded);
     }
 
diff --git a/asl/types/status.cpp b/asl/types/status.cpp
index 43f3b9e..246d017 100644
--- a/asl/types/status.cpp
+++ b/asl/types/status.cpp
@@ -15,7 +15,7 @@ using Allocator = asl::DefaultAllocator;
 // NOLINTNEXTLINE(*-non-const-global-variables)
 static Allocator g_allocator{};
 
-namespace
+namespace asl
 {
 
 struct StatusInternal
@@ -33,7 +33,7 @@ struct StatusInternal
     }
 };
 
-} // anonymous namespace
+}  // namespace asl
 
 asl::status::status(status_code code, string_view msg)
     : m_payload{alloc_new<StatusInternal>(g_allocator, msg, code)}
@@ -49,34 +49,29 @@ asl::status::status(status_code code, string_view fmt, span<format_internals::ty
 asl::status_code asl::status::code_internal() const
 {
     ASL_ASSERT(!is_inline());
-    // NOLINTNEXTLINE(*-reinterpret-cast)
-    return reinterpret_cast<const StatusInternal*>(m_payload)->code;
+    return m_payload->code;
 }
 
 asl::string_view asl::status::message_internal() const
 {
     ASL_ASSERT(!is_inline());
-    // NOLINTNEXTLINE(*-reinterpret-cast)
-    return reinterpret_cast<const StatusInternal*>(m_payload)->msg;
+    return m_payload->msg;
 }
 
 void asl::status::ref()
 {
     ASL_ASSERT(!is_inline());
-    // NOLINTNEXTLINE(*-reinterpret-cast)
-    auto* internal = reinterpret_cast<StatusInternal*>(m_payload);
-    atomic_fetch_increment(&internal->ref_count, memory_order::relaxed);
+    atomic_fetch_increment(&m_payload->ref_count, memory_order::relaxed);
 }
 
 void asl::status::unref()
 {
     ASL_ASSERT(!is_inline());
-    // NOLINTNEXTLINE(*-reinterpret-cast)
-    auto* internal = reinterpret_cast<StatusInternal*>(m_payload);
-    if (atomic_fetch_decrement(&internal->ref_count, memory_order::release) == 1)
+    if (atomic_fetch_decrement(&m_payload->ref_count, memory_order::release) == 1)
     {
         atomic_fence(memory_order::acquire);
-        alloc_delete(g_allocator, internal);
+        alloc_delete(g_allocator, m_payload);
+        m_payload = nullptr;
     }
 }
 
diff --git a/asl/types/status.hpp b/asl/types/status.hpp
index df96cd8..de95670 100644
--- a/asl/types/status.hpp
+++ b/asl/types/status.hpp
@@ -22,15 +22,17 @@ enum class status_code : uint8_t
     invalid_argument = 4,
 };
 
+struct StatusInternal;
+
 class status
 {
-    void* m_payload{};
+    StatusInternal* m_payload{};
 
-    static constexpr void* status_to_payload(status_code code)
+    static constexpr StatusInternal* status_to_payload(status_code code)
     {
         return code == status_code::ok
             ? nullptr
-            : bit_cast<void*>((static_cast<uintptr_t>(code) << 1) | 1);
+            : bit_cast<StatusInternal*>((static_cast<uintptr_t>(code) << 1) | 1);
     }
 
     static constexpr status_code payload_to_status(void* payload)
diff --git a/todo.txt b/todo.txt
index 8b13789..2dfd0c1 100644
--- a/todo.txt
+++ b/todo.txt
@@ -1 +1,3 @@
-
+review unions
+review reinterpret_cast
+review as_bytes & static_cast in general