[llvm] [DebugInfo] Fix memory leak in DebugSSAUpdater (PR #159107)

[Stephen Tozer via llvm-commits]

https://github.com/SLTozer created https://github.com/llvm/llvm-project/pull/159107

Fixes an issue in commit 3946c50, PR #135349.

The DebugSSAUpdater class performs raw pointer allocations. It frees these properly in reset(), but does not do so in its destructor - as an immediate fix, this patch adds a destructor which frees the allocations correctly.

I'll be merging this immediately to fix the issue, but will be open to post-commit review and/or producing a better fix in a follow-up commit.

>From 18563233a6fd0abc031ec495367a1563c6dc276e Mon Sep 17 00:00:00 2001
From: Stephen Tozer <stephen.tozer at sony.com>
Date: Tue, 16 Sep 2025 15:37:05 +0100
Subject: [PATCH] [DebugInfo] Fix memory leak in DebugSSAUpdater

Fixes an issue in commit 3946c50, PR #135349.

The DebugSSAUpdater class performs raw pointer allocations. It frees these
properly in reset(), but does not do so in its destructor - as an immediate
fix, this patch adds a destructor which frees the allocations correctly.
---
 llvm/include/llvm/Transforms/Utils/DebugSSAUpdater.h | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/llvm/include/llvm/Transforms/Utils/DebugSSAUpdater.h b/llvm/include/llvm/Transforms/Utils/DebugSSAUpdater.h
index 90899c86f5c3b..2d25ce3245793 100644
--- a/llvm/include/llvm/Transforms/Utils/DebugSSAUpdater.h
+++ b/llvm/include/llvm/Transforms/Utils/DebugSSAUpdater.h
@@ -235,6 +235,11 @@ class DebugSSAUpdater {
   DebugSSAUpdater(const DebugSSAUpdater &) = delete;
   DebugSSAUpdater &operator=(const DebugSSAUpdater &) = delete;
 
+  ~DebugSSAUpdater() {
+    for (auto &Block : BlockMap)
+      delete Block.second;
+  }
+
   void reset() {
     for (auto &Block : BlockMap)
       delete Block.second;