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

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llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-clang

Author: Nathan Ridge (HighCommander4)

<details>
<summary>Changes</summary>



---
Full diff: https://github.com/llvm/llvm-project/pull/126690.diff


1 Files Affected:

- (modified) clang/lib/Sema/HeuristicResolver.cpp (+5-1) 


``````````diff
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;

``````````

</details>


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