[llvm] Suppress GCC dangling-pointer false positive for RAII listener pattern (PR #180875)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-llvm-selectiondag

Author: Eric Christopher (echristo)

<details>
<summary>Changes</summary>

GCC warns about storing `this` here but the destructor cleans it up, so it's a false positive. Suppress with a pragma.

Built with ToT clang and GCC 13.3.0 on Linux x86_64. All existing tests pass.

---
Full diff: https://github.com/llvm/llvm-project/pull/180875.diff


1 Files Affected:

- (modified) llvm/include/llvm/CodeGen/SelectionDAG.h (+8) 


``````````diff
diff --git a/llvm/include/llvm/CodeGen/SelectionDAG.h b/llvm/include/llvm/CodeGen/SelectionDAG.h
index 9b4b57099889a..7e24046a76c6f 100644
--- a/llvm/include/llvm/CodeGen/SelectionDAG.h
+++ b/llvm/include/llvm/CodeGen/SelectionDAG.h
@@ -324,7 +324,15 @@ class SelectionDAG {
 
     explicit DAGUpdateListener(SelectionDAG &D)
       : Next(D.UpdateListeners), DAG(D) {
+      // False positive - RAII pattern, destructor cleans up.
+#if defined(__GNUC__) && !defined(__clang__)
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wdangling-pointer"
+#endif
       DAG.UpdateListeners = this;
+#if defined(__GNUC__) && !defined(__clang__)
+#pragma GCC diagnostic pop
+#endif
     }
 
     virtual ~DAGUpdateListener() {

``````````

</details>


https://github.com/llvm/llvm-project/pull/180875