[flang][fir][NFC] Remove dead code.

[schweitz]

Summary

This patch removes OpaqueAttr as it is no longer used.

flang/include/flang/Optimizer/Dialect/FIRAttr.h

 class DialectAsmPrinter;
 } // namespace mlir
 
 namespace fir {
 
 class FIROpsDialect;
 
 namespace detail {
-struct OpaqueAttributeStorage;
 struct RealAttributeStorage;
 struct TypeAttributeStorage;
 } // namespace detail
 
 using KindTy = unsigned;
 
 class ExactTypeAttr
     : public mlir::Attribute::AttrBase<ExactTypeAttr, mlir::Attribute,
public:
 
   static constexpr llvm::StringRef getAttrName() { return "real"; }
   static RealAttr get(mlir::MLIRContext *ctxt, const ValueType &key);
 
   KindTy getFKind() const;
   llvm::APFloat getValue() const;
 };
 
-/// An opaque attribute is used to provide dictionary lookups of pointers. The
-/// underlying type of the pointee object is left up to the client. Opaque
-/// attributes are always constructed as null pointers when parsing. Clearly,
-/// opaque attributes come with restrictions and must be used with care.
-/// 1. An opaque attribute should not refer to information of semantic
-/// significance, since the pointed-to object will not be a part of
-/// round-tripping the IR.
-/// 2. The lifetime of the pointed-to object must outlive any possible uses
-/// via the opaque attribute.
-class OpaqueAttr
-    : public mlir::Attribute::AttrBase<OpaqueAttr, mlir::Attribute,
-                                       detail::OpaqueAttributeStorage> {
-public:
-  using Base::Base;
-
-  static constexpr llvm::StringRef getAttrName() { return "opaque"; }
-  static OpaqueAttr get(mlir::MLIRContext *ctxt, void *pointer);
-
-  void *getPointer() const;
-};
-
 mlir::Attribute parseFirAttribute(FIROpsDialect *dialect,
                                   mlir::DialectAsmParser &parser,
                                   mlir::Type type);
 
 void printFirAttribute(FIROpsDialect *dialect, mlir::Attribute attr,
                        mlir::DialectAsmPrinter &p);
 
 } // namespace fir
 
 #endif // FORTRAN_OPTIMIZER_DIALECT_FIRATTR_H

flang/lib/Optimizer/Dialect/FIRAttr.cpp

return new (allocator.allocate<TypeAttributeStorage>())
         TypeAttributeStorage(key);
   }
 
   mlir::Type getType() const { return value; }
 
 private:
   mlir::Type value;
 };
-
-/// An attribute representing a raw pointer.
-struct OpaqueAttributeStorage : public mlir::AttributeStorage {
-  using KeyTy = void *;
-
-  OpaqueAttributeStorage(void *value) : value(value) {}
-
-  /// Key equality function.
-  bool operator==(const KeyTy &key) const { return key == value; }
-
-  /// Construct a new storage instance.
-  static OpaqueAttributeStorage *
-  construct(mlir::AttributeStorageAllocator &allocator, KeyTy key) {
-    return new (allocator.allocate<OpaqueAttributeStorage>())
-        OpaqueAttributeStorage(key);
-  }
-
-  void *getPointer() const { return value; }
-
-private:
-  void *value;
-};
 } // namespace fir::detail
 
 //===----------------------------------------------------------------------===//
 // Attributes for SELECT TYPE
 //===----------------------------------------------------------------------===//
 
 ExactTypeAttr fir::ExactTypeAttr::get(mlir::Type value) {
   return Base::get(value.getContext(), value);
RealAttr fir::RealAttr::get(mlir::MLIRContext *ctxt,
   return Base::get(ctxt, key);
 }
 
 KindTy fir::RealAttr::getFKind() const { return getImpl()->getFKind(); }
 
 llvm::APFloat fir::RealAttr::getValue() const { return getImpl()->getValue(); }
 
 //===----------------------------------------------------------------------===//
-// OpaqueAttr
-//===----------------------------------------------------------------------===//
-
-OpaqueAttr fir::OpaqueAttr::get(mlir::MLIRContext *ctxt, void *key) {
-  return Base::get(ctxt, key);
-}
-
-void *fir::OpaqueAttr::getPointer() const { return getImpl()->getPointer(); }
-
-//===----------------------------------------------------------------------===//
 // FIR attribute parsing
 //===----------------------------------------------------------------------===//
 
 static mlir::Attribute parseFirRealAttr(FIROpsDialect *dialect,
                                         mlir::DialectAsmParser &parser,
                                         mlir::Type type) {
   int kind = 0;
   if (parser.parseLess() || parser.parseInteger(kind) || parser.parseComma()) {
mlir::Attribute fir::parseFirAttribute(FIROpsDialect *dialect,
   if (attrName == SubclassAttr::getAttrName()) {
     mlir::Type type;
     if (parser.parseLess() || parser.parseType(type) || parser.parseGreater()) {
       parser.emitError(loc, "expected a subtype");
       return {};
     }
     return SubclassAttr::get(type);
   }
-  if (attrName == OpaqueAttr::getAttrName()) {
-    if (parser.parseLess() || parser.parseGreater()) {
-      parser.emitError(loc, "expected <>");
-      return {};
-    }
-    // NB: opaque pointers are always parsed in as nullptrs. The tool must
-    // rebuild the context.
-    return OpaqueAttr::get(dialect->getContext(), nullptr);
-  }
   if (attrName == PointIntervalAttr::getAttrName())
     return PointIntervalAttr::get(dialect->getContext());
   if (attrName == LowerBoundAttr::getAttrName())
     return LowerBoundAttr::get(dialect->getContext());
   if (attrName == UpperBoundAttr::getAttrName())
     return UpperBoundAttr::get(dialect->getContext());
   if (attrName == ClosedIntervalAttr::getAttrName())
     return ClosedIntervalAttr::get(dialect->getContext());
if (auto exact = attr.dyn_cast<fir::ExactTypeAttr>()) {
     os << fir::LowerBoundAttr::getAttrName();
   } else if (attr.dyn_cast_or_null<fir::UpperBoundAttr>()) {
     os << fir::UpperBoundAttr::getAttrName();
   } else if (auto a = attr.dyn_cast_or_null<fir::RealAttr>()) {
     os << fir::RealAttr::getAttrName() << '<' << a.getFKind() << ", i x";
     llvm::SmallString<40> ss;
     a.getValue().bitcastToAPInt().toStringUnsigned(ss, 16);
     os << ss << '>';
-  } else if (attr.isa<fir::OpaqueAttr>()) {
-    os << fir::OpaqueAttr::getAttrName() << "<>";
   } else {
     // don't know how to print the attribute, so use a default
     os << "<(unknown attribute)>";
   }
 }

flang/lib/Optimizer/Dialect/FIRDialect.cpp

 
 fir::FIROpsDialect::FIROpsDialect(mlir::MLIRContext *ctx)
     : mlir::Dialect("fir", ctx, mlir::TypeID::get<FIROpsDialect>()) {
   addTypes<BoxType, BoxCharType, BoxProcType, CharacterType, fir::ComplexType,
            FieldType, HeapType, fir::IntegerType, LenType, LogicalType,
            PointerType, RealType, RecordType, ReferenceType, SequenceType,
            ShapeType, ShapeShiftType, SliceType, TypeDescType,
            fir::VectorType>();
-  addAttributes<ClosedIntervalAttr, ExactTypeAttr, LowerBoundAttr, OpaqueAttr,
+  addAttributes<ClosedIntervalAttr, ExactTypeAttr, LowerBoundAttr,
                 PointIntervalAttr, RealAttr, SubclassAttr, UpperBoundAttr>();
   addOperations<
 #define GET_OP_LIST
 #include "flang/Optimizer/Dialect/FIROps.cpp.inc"
       >();
 }
 
 // anchor the class vtable to this compilation unit

flang/test/Fir/fir-ops.fir

 func private @get_method_box() -> !fir.box<!fir.type<derived3{f:f32}>>
 func private @method_impl(!fir.box<!fir.type<derived3{f:f32}>>)
 
 // CHECK-LABEL: func private @nop()
 // CHECK-LABEL: func private @get_func() -> (() -> ())
 func private @nop()
 func private @get_func() -> (() -> ())
 
-// CHECK-LABEL: func private @attr1() -> none attributes {a = #fir.opaque<>, b = #fir.opaque<>}
-func private @attr1() -> none attributes {a = #fir.opaque<>, b = #fir.opaque<>}
-
 // CHECK-LABEL:       func @instructions() {
 func @instructions() {
 // CHECK: [[VAL_0:%.*]] = fir.alloca !fir.array<10xi32>
 // CHECK: [[VAL_1:%.*]] = fir.load [[VAL_0]] : !fir.ref<!fir.array<10xi32>>
 // CHECK: [[VAL_2:%.*]] = fir.alloca i32
 // CHECK: [[VAL_3:%.*]] = constant 22 : i32
   %0 = fir.alloca !fir.array<10xi32>
   %1 = fir.load %0 : !fir.ref<!fir.array<10xi32>>