[mlir] Promote the SubElementInterfaces to a core Attribute/Type construct

This commit restructures the sub element infrastructure to be a core part
of attributes and types, instead of being relegated to an interface. This
establishes sub element walking/replacement as something "always there",
which makes it easier to rely on for correctness/etc (which various bits of
infrastructure want, such as Symbols).

Attribute/Type now have `walk` and `replace` methods directly
accessible, which provide power API for interacting with sub elements. As
part of this, a new AttrTypeWalker class is introduced that supports caching
walked attributes/types, and a friendlier API (see the simplification of symbol
walking in SymbolTable.cpp).

Differential Revision: https://reviews.llvm.org/D142272

1 files changed, 0 insertions, 36 deletions

diff --git a/mlir/unittests/IR/SubElementInterfaceTest.cpp b/mlir/unittests/IR/SubElementInterfaceTest.cpp
deleted file mode 100644
index ab461f4dc340..000000000000
--- a/mlir/unittests/IR/SubElementInterfaceTest.cpp
+++ /dev/null
@@ -1,36 +0,0 @@
-//===- SubElementInterfaceTest.cpp - SubElementInterface unit tests -------===//
-//
-// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-// See https://llvm.org/LICENSE.txt for license information.
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-//
-//===----------------------------------------------------------------------===//
-
-#include "mlir/IR/Builders.h"
-#include "mlir/IR/BuiltinAttributes.h"
-#include "mlir/IR/SubElementInterfaces.h"
-#include "gtest/gtest.h"
-#include <cstdint>
-
-using namespace mlir;
-using namespace mlir::detail;
-
-namespace {
-TEST(SubElementInterfaceTest, Nested) {
-  MLIRContext context;
-  Builder builder(&context);
-
-  BoolAttr trueAttr = builder.getBoolAttr(true);
-  BoolAttr falseAttr = builder.getBoolAttr(false);
-  ArrayAttr boolArrayAttr = builder.getArrayAttr({trueAttr, falseAttr});
-  StringAttr strAttr = builder.getStringAttr("array");
-  DictionaryAttr dictAttr =
-      builder.getDictionaryAttr(builder.getNamedAttr(strAttr, boolArrayAttr));
-
-  SmallVector<Attribute> subAttrs;
-  dictAttr.walkSubAttrs([&](Attribute attr) { subAttrs.push_back(attr); });
-  EXPECT_EQ(llvm::ArrayRef(subAttrs),
-            ArrayRef<Attribute>({strAttr, trueAttr, falseAttr, boolArrayAttr}));
-}
-
-} // namespace