[MLIR] Mark additional builtin attr methods const

[fabianschuiki]

Summary

• Mark the following methods const:
  • ArrayAttr::getAsRange
  • ArrayAttr::getAsValueRange
  • DictionaryAttr::getAs(StringRef)
• Add a DictionarAttr::getAs(Identifier) overload that may be faster in some cases.

[rriddle]

mlir/include/mlir/IR/BuiltinAttributes.h

13 ↗

(On Diff #350311)

Please try to avoid the need for an extra dependency here.

[fabianschuiki]

mlir/include/mlir/IR/BuiltinAttributes.h

13 ↗

(On Diff #350311)

Done. Only way I found to avoid this is to make getAs generic over the type of its name argument. Otherwise the compiler would choke on Identifier being an incomplete type, requiring all places that include BuiltinAttributes.h to also include Identifier.h. With the template the only place where this is necessary are call sites that pass in an Identifier, which are already very likely to include the appropriate header.

[rriddle]

mlir/include/mlir/IR/BuiltinAttributes.td

349

nit; You'll likely want to do NameClass && here.

[fabianschuiki]

mlir/include/mlir/IR/BuiltinAttributes.td

349

Added in 41135a4367a7.

mlir/include/mlir/IR/BuiltinAttributes.td

public:
       explicit attr_value_iterator(ArrayAttr::iterator it)
           : llvm::mapped_iterator<ArrayAttr::iterator, AttrTy (*)(Attribute)>(
                 it, [](Attribute attr) { return attr.cast<AttrTy>(); }) {}
       AttrTy operator*() const { return (*this->I).template cast<AttrTy>(); }
     };
 
   public:
     template <typename AttrTy>
-    iterator_range<attr_value_iterator<AttrTy>> getAsRange() {
+    iterator_range<attr_value_iterator<AttrTy>> getAsRange() const {
       return llvm::make_range(attr_value_iterator<AttrTy>(begin()),
                               attr_value_iterator<AttrTy>(end()));
     }
     template <typename AttrTy,
               typename UnderlyingTy = typename AttrTy::ValueType>
-    auto getAsValueRange() {
+    auto getAsValueRange() const {
       return llvm::map_range(getAsRange<AttrTy>(), [](AttrTy attr) {
         return static_cast<UnderlyingTy>(attr.getValue());
       });
     }
   }];
 }
 
 //===----------------------------------------------------------------------===//
let extraClassDeclaration = [{
     /// Returns an entry with a duplicate name in `array`, if it exists, else
     /// returns llvm::None. If `isSorted` is true, the array is assumed to be
     /// sorted else it will be sorted in place before finding the duplicate entry.
     static Optional<NamedAttribute>
     findDuplicate(SmallVectorImpl<NamedAttribute> &array, bool isSorted);
 
     /// Return the specified attribute if present and is an instance of
     /// `AttrClass`, null otherwise.
-    template<typename AttrClass>
-    AttrClass getAs(StringRef name) {
-      return get(name).dyn_cast_or_null<AttrClass>();
+    template<typename AttrClass, typename NameClass>
+    AttrClass getAs(NameClass name) const {
+      return get(name).template dyn_cast_or_null<AttrClass>();
     }
 
   private:
     /// Return empty dictionary.
     static DictionaryAttr getEmpty(MLIRContext *context);
 
     /// Return empty dictionary. This is a special variant of the above method
     /// that is used by the MLIRContext to cache the empty dictionary instance.