[llvm-branch-commits] [clang] [clang][HeuristicResolver] Additional hardening against an infinite loop in simplifyType() (PR #126690)

[Nathan Ridge via llvm-branch-commits]

https://github.com/HighCommander4 created https://github.com/llvm/llvm-project/pull/126690

None

>From 28630abecc42c23527687b84be8cb4dbcd2ca5d9 Mon Sep 17 00:00:00 2001
From: Nathan Ridge <zeratul976 at hotmail.com>
Date: Tue, 11 Feb 2025 02:06:32 -0500
Subject: [PATCH] [clang][HeuristicResolver] Additional hardening against an
 infinite loop in simplifyType()

---
 clang/lib/Sema/HeuristicResolver.cpp | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/clang/lib/Sema/HeuristicResolver.cpp b/clang/lib/Sema/HeuristicResolver.cpp
index 3cbf33dcdced38..adce403412f689 100644
--- a/clang/lib/Sema/HeuristicResolver.cpp
+++ b/clang/lib/Sema/HeuristicResolver.cpp
@@ -258,7 +258,11 @@ QualType HeuristicResolverImpl::simplifyType(QualType Type, const Expr *E,
     }
     return T;
   };
-  while (!Current.Type.isNull()) {
+  // As an additional protection against infinite loops, bound the number of
+  // simplification steps.
+  size_t StepCount = 0;
+  const size_t MaxSteps = 64;
+  while (!Current.Type.isNull() && StepCount++ < MaxSteps) {
     TypeExprPair New = SimplifyOneStep(Current);
     if (New.Type == Current.Type)
       break;