[clang] [clang] Avoid stack exhaustion in recursive `constexpr` calls (PR #201706)

[Tony Guillot via cfe-commits]

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@@ -816,6 +817,8 @@ namespace {
     /// initialized after CurrentCall and CallStackDepth.
     CallStackFrame BottomFrame;
 
+    StackExhaustionHandler StackHandler;
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to268 wrote:

Add a documentation comment to describe how that class member is used.

https://github.com/llvm/llvm-project/pull/201706