Also deprecate mlir::pdll::ast::Type cast members.

Remove member cast overload in TypeSwitch so we don't have to disable the warning.

Author: chsigg

llvm/include/llvm/ADT/TypeSwitch.h

@@ -61,32 +61,9 @@ template <typename DerivedT, typename T> class TypeSwitchBase {
   }
 
 protected:
-  /// Trait to check whether `ValueT` provides a 'dyn_cast' method with type
-  /// `CastT`.
-  template <typename ValueT, typename CastT>
-  using has_dyn_cast_t =
-      decltype(std::declval<ValueT &>().template dyn_cast<CastT>());
-
-  /// Attempt to dyn_cast the given `value` to `CastT`. This overload is
-  /// selected if `value` already has a suitable dyn_cast method.
+  /// Attempt to dyn_cast the given `value` to `CastT`.
   template <typename CastT, typename ValueT>
-  static decltype(auto) castValue(
-      ValueT &&value,
-      std::enable_if_t<is_detected<has_dyn_cast_t, ValueT, CastT>::value> * =
-          nullptr) {
-    // Silence warnings about MLIR's deprecated dyn_cast member functions.
-    LLVM_SUPPRESS_DEPRECATED_DECLARATIONS_PUSH;
-    return value.template dyn_cast<CastT>();
-    LLVM_SUPPRESS_DEPRECATED_DECLARATIONS_POP;
-  }
-
-  /// Attempt to dyn_cast the given `value` to `CastT`. This overload is
-  /// selected if llvm::dyn_cast should be used.
-  template <typename CastT, typename ValueT>
-  static decltype(auto) castValue(
-      ValueT &&value,
-      std::enable_if_t<!is_detected<has_dyn_cast_t, ValueT, CastT>::value> * =
-          nullptr) {
+  static decltype(auto) castValue(ValueT &&value) {
     return dyn_cast<CastT>(value);
   }
 

mlir/include/mlir/Tools/PDLL/AST/Types.h

@@ -64,23 +64,28 @@ class Type {
 
   /// Provide type casting support.
   template <typename U>
+  [[deprecated("Use mlir::isa<U>() instead")]]
   bool isa() const {
     assert(impl && "isa<> used on a null type.");
     return U::classof(*this);
   }
   template <typename U, typename V, typename... Others>
+  [[deprecated("Use mlir::isa<U>() instead")]]
   bool isa() const {
     return isa<U>() || isa<V, Others...>();
   }
   template <typename U>
+  [[deprecated("Use mlir::dyn_cast<U>() instead")]]
   U dyn_cast() const {
     return isa<U>() ? U(impl) : U(nullptr);
   }
   template <typename U>
+  [[deprecated("Use mlir::dyn_cast_or_null<U>() instead")]]
   U dyn_cast_or_null() const {
     return (impl && isa<U>()) ? U(impl) : U(nullptr);
   }
   template <typename U>
+  [[deprecated("Use mlir::cast<U>() instead")]]
   U cast() const {
     assert(isa<U>());
     return U(impl);
@@ -323,6 +328,29 @@ struct DenseMapInfo<mlir::pdll::ast::Type> {
     return lhs == rhs;
   }
 };
+
+/// Add support for llvm style casts.
+/// We provide a cast between To and From if From is mlir::pdll::ast::Type or
+/// derives from it
+template <typename To, typename From>
+struct CastInfo<
+    To, From,
+    std::enable_if_t<
+        std::is_same_v<mlir::pdll::ast::Type, std::remove_const_t<From>> ||
+        std::is_base_of_v<mlir::pdll::ast::Type, From>>>
+    : NullableValueCastFailed<To>,
+      DefaultDoCastIfPossible<To, From, CastInfo<To, From>> {
+  static inline bool isPossible(mlir::pdll::ast::Type ty) {
+    /// Return a constant true instead of a dynamic true when casting to self or
+    /// up the hierarchy.
+    if constexpr (std::is_base_of_v<To, From>) {
+      return true;
+    } else {
+      return To::classof(ty);
+    };
+  }
+  static inline To doCast(mlir::pdll::ast::Type ty) { return To(ty.getImpl()); }
+};
 } // namespace llvm
 
 #endif // MLIR_TOOLS_PDLL_AST_TYPES_H_