From 33dbe385cec8edd62425d7d722082dcd907d5cd3 Mon Sep 17 00:00:00 2001
From: Daniel Bertalan <dani@danielbertalan.dev>
Date: Sat, 17 May 2025 11:22:02 +0200
Subject: [PATCH] AK: Replace `CallableWrapper::destroy()` with a destructor
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Previously, heap-allocated `CallableWrapper` objects were destroyed in a
very roundabout way: `AK::Function` would call a virtual `destroy()`
method, which then invoked delete manually. This was unnecessary, since
`CallableWrapper` already has a virtual destructor — deleting it through
a `CallableWrapperBase*` correctly calls the closure's destructor.

This fixes GCC `-Wfree-nonheap-object` false positive warnings (#4721)
and coincidentally removes 8 KB of vtable entries (and the corresponding
relative relocations) from LibJS.
---
 AK/Function.h | 10 ++--------
 1 file changed, 2 insertions(+), 8 deletions(-)

diff --git a/AK/Function.h b/AK/Function.h
index d1a8a4b900..3f929da139 100644
--- a/AK/Function.h
+++ b/AK/Function.h
@@ -205,7 +205,6 @@ private:
         virtual ~CallableWrapperBase() = default;
         // Note: This is not const to allow storing mutable lambdas.
         virtual Out call(In...) = 0;
-        virtual void destroy() = 0;
         virtual void init_and_swap(u8*, size_t) = 0;
         virtual void const* raw_callable() const = 0;
     };
@@ -226,16 +225,13 @@ private:
             return m_callable(forward<In>(in)...);
         }
 
-        void destroy() final override
+        virtual ~CallableWrapper() final override
         {
             if constexpr (IsBlockClosure<CallableType>) {
                 if constexpr (Detail::HaveObjcArc)
                     m_callable = nullptr;
                 else
                     _Block_release(m_callable);
-            } else {
-                // This code is a bit too clever for gcc. Pinky promise we're only deleting heap objects.
-                AK_IGNORE_DIAGNOSTIC("-Wfree-nonheap-object", delete this);
             }
         }
 
@@ -298,12 +294,10 @@ private:
             break;
         case FunctionKind::Outline:
             VERIFY(wrapper);
-            // This code is a bit too clever for gcc. Pinky promise we're only deleting heap objects.
-            AK_IGNORE_DIAGNOSTIC("-Wfree-nonheap-object", wrapper->destroy());
+            delete wrapper;
             break;
         case FunctionKind::Block:
             VERIFY(wrapper);
-            wrapper->destroy();
             wrapper->~CallableWrapperBase();
             break;
         case FunctionKind::NullPointer: