[clang] [CIR] Lowering to LLVM for global pointers (PR #125619)

[Erich Keane via cfe-commits]

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@@ -0,0 +1,51 @@
+#ifndef LLVM_CLANG_CIR_DIALECT_IR_CIRATTRVISITOR_H
+#define LLVM_CLANG_CIR_DIALECT_IR_CIRATTRVISITOR_H
+
+#include "clang/CIR/Dialect/IR/CIRAttrs.h"
+
+namespace cir {
+
+template <typename ImplClass, typename RetTy> class CirAttrVisitor {
+public:
+  // FIXME: Create a TableGen list to automatically handle new attributes
+  template <typename... Args>
+  RetTy visit(mlir::Attribute attr, Args &&...args) {
+    if (const auto intAttr = mlir::dyn_cast<cir::IntAttr>(attr))
+      return static_cast<ImplClass *>(this)->visitCirIntAttr(
+          intAttr, std::forward<Args>(args)...);
+    if (const auto fltAttr = mlir::dyn_cast<cir::FPAttr>(attr))
+      return static_cast<ImplClass *>(this)->visitCirFPAttr(
+          fltAttr, std::forward<Args>(args)...);
+    if (const auto ptrAttr = mlir::dyn_cast<cir::ConstPtrAttr>(attr))
+      return static_cast<ImplClass *>(this)->visitCirConstPtrAttr(
+          ptrAttr, std::forward<Args>(args)...);
+    llvm_unreachable("unhandled attribute type");
+  }
+
+  // If the implementation chooses not to implement a certain visit
+  // method, fall back to the parent.
+  template <typename... Args>
+  RetTy visitCirIntAttr(cir::IntAttr attr, Args &&...args) {
+    return static_cast<ImplClass *>(this)->visitCirAttr(
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erichkeane wrote:

These will cause a stack overflow, as they end up calling themselves. 

https://github.com/llvm/llvm-project/pull/125619