[clang] [Clang] Protect ObjCMethodList assignment operator against self-assig… (PR #97933)

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llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-clang

Author: None (smanna12)

<details>
<summary>Changes</summary>

This patch adds a self-assignment check to the ObjCMethodList assignment operator to prevent issues when an object is assigned to itself.

The fix ensures the integrity of the object's data during such assignments.

---
Full diff: https://github.com/llvm/llvm-project/pull/97933.diff


1 Files Affected:

- (modified) clang/include/clang/Sema/ObjCMethodList.h (+4-2) 


``````````diff
diff --git a/clang/include/clang/Sema/ObjCMethodList.h b/clang/include/clang/Sema/ObjCMethodList.h
index 9e65e0d8e00af1..c4465f6ab59fd7 100644
--- a/clang/include/clang/Sema/ObjCMethodList.h
+++ b/clang/include/clang/Sema/ObjCMethodList.h
@@ -37,8 +37,10 @@ struct ObjCMethodList {
         NextAndExtraBits(L.NextAndExtraBits) {}
 
   ObjCMethodList &operator=(const ObjCMethodList &L) {
-    MethodAndHasMoreThanOneDecl = L.MethodAndHasMoreThanOneDecl;
-    NextAndExtraBits = L.NextAndExtraBits;
+    if (this != &L) { // Check for self-assignment
+      MethodAndHasMoreThanOneDecl = L.MethodAndHasMoreThanOneDecl;
+      NextAndExtraBits = L.NextAndExtraBits;
+    }
     return *this;
   }
 

``````````

</details>


https://github.com/llvm/llvm-project/pull/97933