[llvm-branch-commits] [CodeGen][CFI] Generalize transparent union in args of args of functions (PR #158194)

[Peter Collingbourne via llvm-branch-commits]

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@@ -2360,12 +2363,19 @@ static QualType GeneralizeType(ASTContext &Ctx, QualType Ty,
                                bool GeneralizePointers) {
   Ty = GeneralizeTransparentUnion(Ty);
 
-  if (!GeneralizePointers || !Ty->isPointerType())
+  if (!Ty->isPointerType())
+    return Ty;
+
+  QualType PTy = Ty->getPointeeType();
+  if (PTy->getAs<FunctionProtoType>() || PTy->getAs<FunctionNoProtoType>())
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pcc wrote:

I guess this is not the only way you can end up with a function type. E.g. pointer to pointer to function, reference to pointer to function, etc.

What do you think about doing this in the mangler? E.g. add a call to a hook near the top of `void CXXNameMangler::mangleType(QualType T)` and supply a hook that does the transparent_union generalization from here.

https://github.com/llvm/llvm-project/pull/158194