[llvm] Make SmallVectorImpl destructor protected (PR #71746)

[Andy Kaylor via llvm-commits]

https://github.com/andykaylor created https://github.com/llvm/llvm-project/pull/71746

Because the SmallVectorImpl destructor is not virtual, the destructor of derived classes will not be called if pointers to the SmallVectorImpl class are deleted directly. Making the SmallVectorImpl destructor protected will prevent this.

>From 08e6f26b3458e2e5581dfbf57905fdae2db4b3e3 Mon Sep 17 00:00:00 2001
From: Andy Kaylor <andrew.kaylor at intel.com>
Date: Mon, 6 Nov 2023 11:46:17 -0800
Subject: [PATCH] Make SmallVectorImpl destructor protected

Because the SmallVectorImpl destructor is not virtual, the destructor of
derived classes will not be called if pointers to the SmallVectorImpl class are deleted directly. Making the SmallVectorImpl destructor protected will prevent this.
---
 llvm/include/llvm/ADT/SmallVector.h | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/llvm/include/llvm/ADT/SmallVector.h b/llvm/include/llvm/ADT/SmallVector.h
index 53a107b1574c6a3..2e6d2dc6ce90a2c 100644
--- a/llvm/include/llvm/ADT/SmallVector.h
+++ b/llvm/include/llvm/ADT/SmallVector.h
@@ -601,9 +601,6 @@ class SmallVectorImpl : public SmallVectorTemplateBase<T> {
     RHS.resetToSmall();
   }
 
-public:
-  SmallVectorImpl(const SmallVectorImpl &) = delete;
-
   ~SmallVectorImpl() {
     // Subclass has already destructed this vector's elements.
     // If this wasn't grown from the inline copy, deallocate the old space.
@@ -611,6 +608,9 @@ class SmallVectorImpl : public SmallVectorTemplateBase<T> {
       free(this->begin());
   }
 
+public:
+  SmallVectorImpl(const SmallVectorImpl &) = delete;
+
   void clear() {
     this->destroy_range(this->begin(), this->end());
     this->Size = 0;