[clang] nonblocking/nonallocating attributes (was: nolock/noalloc) (PR #84983)

[Doug Wyatt via cfe-commits]

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@@ -464,6 +466,16 @@ class ASTContext : public RefCountedBase<ASTContext> {
   /// This is the top-level (C++20) Named module we are building.
   Module *CurrentCXXNamedModule = nullptr;
 
+  class FunctionEffectSetUniquing {
+    llvm::DenseSet<llvm::ArrayRef<FunctionEffect>> Set;
+
+  public:
+    FunctionEffectSet getUniqued(llvm::ArrayRef<FunctionEffect> FX);
+
+    ~FunctionEffectSetUniquing();
+  };
+  FunctionEffectSetUniquing UniquedFunctionEffectSet;
+
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dougsonos wrote:

The idea here was that since the set elements are `ArrayRef`s pointing to separately allocated memory, the destructor of this object could do all the destruction. Moot if this uniquing business goes away though.

https://github.com/llvm/llvm-project/pull/84983