diff --git a/mlir/include/mlir/IR/BuiltinAttributes.td b/mlir/include/mlir/IR/BuiltinAttributes.td
--- a/mlir/include/mlir/IR/BuiltinAttributes.td
+++ b/mlir/include/mlir/IR/BuiltinAttributes.td
@@ -817,10 +817,25 @@
       return $_get(type.getContext(), bytes, type);
     }]>,
     AttrBuilder<(ins "StringRef":$bytes), [{
+      if (bytes.empty())
+        return get($_ctxt);
       return $_get($_ctxt, bytes, NoneType::get($_ctxt));
-    }]>
+    }]>,
+
+    /// Build an empty string attr with NoneType.
+    AttrBuilder<(ins)>
   ];
-  let extraClassDeclaration = "using ValueType = StringRef;";
+  let extraClassDeclaration = [{
+    using ValueType = StringRef;
+
+  private:
+    /// Return an empty StringAttr with NoneType type. This is a special variant
+    /// of the `get` method that is used by the MLIRContext to cache the
+    /// instance.
+    static StringAttr getEmptyStringAttrUnchecked(MLIRContext *context);
+    friend MLIRContext;
+  public:
+  }];
   let skipDefaultBuilders = 1;
 }
 
diff --git a/mlir/lib/IR/BuiltinAttributes.cpp b/mlir/lib/IR/BuiltinAttributes.cpp
--- a/mlir/lib/IR/BuiltinAttributes.cpp
+++ b/mlir/lib/IR/BuiltinAttributes.cpp
@@ -196,6 +196,10 @@
   return Base::get(context, ArrayRef<NamedAttribute>());
 }
 
+StringAttr StringAttr::getEmptyStringAttrUnchecked(MLIRContext *context) {
+  return Base::get(context, "", NoneType::get(context));
+}
+
 //===----------------------------------------------------------------------===//
 // FloatAttr
 //===----------------------------------------------------------------------===//
diff --git a/mlir/lib/IR/MLIRContext.cpp b/mlir/lib/IR/MLIRContext.cpp
--- a/mlir/lib/IR/MLIRContext.cpp
+++ b/mlir/lib/IR/MLIRContext.cpp
@@ -332,6 +332,7 @@
   UnitAttr unitAttr;
   UnknownLoc unknownLocAttr;
   DictionaryAttr emptyDictionaryAttr;
+  StringAttr emptyStringAttr;
 
 public:
   MLIRContextImpl() : identifiers(identifierAllocator) {}
@@ -400,6 +401,8 @@
   impl->unitAttr = AttributeUniquer::get<UnitAttr>(this);
   /// The empty dictionary attribute.
   impl->emptyDictionaryAttr = DictionaryAttr::getEmptyUnchecked(this);
+  /// The empty string attribute.
+  impl->emptyStringAttr = StringAttr::getEmptyStringAttrUnchecked(this);
 
   // Register the affine storage objects with the uniquer.
   impl->affineUniquer
@@ -929,6 +932,11 @@
   return context->getImpl().emptyDictionaryAttr;
 }
 
+/// Return an empty string.
+StringAttr StringAttr::get(MLIRContext *context) {
+  return context->getImpl().emptyStringAttr;
+}
+
 //===----------------------------------------------------------------------===//
 // AffineMap uniquing
 //===----------------------------------------------------------------------===//