Replace StructDecoration::IsBlock with Castable

Change-Id: I4b053aab610b18f99b72156f92317bc8eaf430b4
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/34313
Reviewed-by: dan sinclair <dsinclair@chromium.org>

src/ast/struct.cc

@@ -14,6 +14,8 @@
 
 #include "src/ast/struct.h"
 
+#include "src/ast/struct_block_decoration.h"
+
 namespace tint {
 namespace ast {
 
@@ -52,7 +54,7 @@ StructMember* Struct::get_member(const std::string& name) const {
 
 bool Struct::IsBlockDecorated() const {
   for (auto* deco : decorations_) {
-    if (deco->IsBlock()) {
+    if (deco->Is<StructBlockDecoration>()) {
       return true;
     }
   }

src/ast/struct_block_decoration.cc

@@ -22,10 +22,6 @@ StructBlockDecoration::StructBlockDecoration(const Source& source)
 
 StructBlockDecoration::~StructBlockDecoration() = default;
 
-bool StructBlockDecoration::IsBlock() const {
-  return true;
-}
-
 void StructBlockDecoration::to_str(std::ostream& out, size_t indent) const {
   make_indent(out, indent);
   out << "block";

src/ast/struct_block_decoration.h

@@ -33,9 +33,6 @@ class StructBlockDecoration
   explicit StructBlockDecoration(const Source& source);
   ~StructBlockDecoration() override;
 
-  /// @returns true if this is a block struct
-  bool IsBlock() const override;
-
   /// Outputs the decoration to the given stream
   /// @param out the stream to write to
   /// @param indent number of spaces to indent the node when writing

src/ast/struct_decoration.h

@@ -35,9 +35,6 @@ class StructDecoration : public Castable<StructDecoration, Decoration> {
   /// @return the decoration kind
   DecorationKind GetKind() const override;
 
-  /// @returns true if this is a block struct
-  virtual bool IsBlock() const = 0;
-
  protected:
   /// Constructor
   /// @param source the source of this decoration

src/ast/struct_test.cc

@@ -57,7 +57,7 @@ TEST_F(StructTest, Creation_WithDecorations) {
   Struct s{decos, members};
   EXPECT_EQ(s.members().size(), 1u);
   ASSERT_EQ(s.decorations().size(), 1u);
-  EXPECT_TRUE(s.decorations()[0]->IsBlock());
+  EXPECT_TRUE(s.decorations()[0]->Is<StructBlockDecoration>());
   EXPECT_EQ(s.source().range.begin.line, 0u);
   EXPECT_EQ(s.source().range.begin.column, 0u);
   EXPECT_EQ(s.source().range.end.line, 0u);
@@ -79,7 +79,7 @@ TEST_F(StructTest, CreationWithSourceAndDecorations) {
       decos, members};
   EXPECT_EQ(s.members().size(), 1u);
   ASSERT_EQ(s.decorations().size(), 1u);
-  EXPECT_TRUE(s.decorations()[0]->IsBlock());
+  EXPECT_TRUE(s.decorations()[0]->Is<StructBlockDecoration>());
   EXPECT_EQ(s.source().range.begin.line, 27u);
   EXPECT_EQ(s.source().range.begin.column, 4u);
   EXPECT_EQ(s.source().range.end.line, 27u);

src/reader/wgsl/parser_impl_struct_decl_test.cc

@@ -13,6 +13,7 @@
 // limitations under the License.
 
 #include "gtest/gtest.h"
+#include "src/ast/struct_block_decoration.h"
 #include "src/ast/type/struct_type.h"
 #include "src/reader/wgsl/parser_impl.h"
 #include "src/reader/wgsl/parser_impl_test_helper.h"
@@ -65,7 +66,7 @@ TEST_F(ParserImplTest, StructDecl_ParsesWithDecoration) {
   EXPECT_EQ(s->impl()->members()[0]->name(), "a");
   EXPECT_EQ(s->impl()->members()[1]->name(), "b");
   ASSERT_EQ(s->impl()->decorations().size(), 1u);
-  EXPECT_TRUE(s->impl()->decorations()[0]->IsBlock());
+  EXPECT_TRUE(s->impl()->decorations()[0]->Is<ast::StructBlockDecoration>());
 }
 
 TEST_F(ParserImplTest, StructDecl_ParsesWithMultipleDecoration) {
@@ -90,8 +91,8 @@ TEST_F(ParserImplTest, StructDecl_ParsesWithMultipleDecoration) {
   EXPECT_EQ(s->impl()->members()[0]->name(), "a");
   EXPECT_EQ(s->impl()->members()[1]->name(), "b");
   ASSERT_EQ(s->impl()->decorations().size(), 2u);
-  EXPECT_TRUE(s->impl()->decorations()[0]->IsBlock());
-  EXPECT_TRUE(s->impl()->decorations()[1]->IsBlock());
+  EXPECT_TRUE(s->impl()->decorations()[0]->Is<ast::StructBlockDecoration>());
+  EXPECT_TRUE(s->impl()->decorations()[1]->Is<ast::StructBlockDecoration>());
 }
 
 TEST_F(ParserImplTest, StructDecl_EmptyMembers) {

src/reader/wgsl/parser_impl_struct_decoration_decl_test.cc

@@ -13,6 +13,7 @@
 // limitations under the License.
 
 #include "gtest/gtest.h"
+#include "src/ast/struct_block_decoration.h"
 #include "src/reader/wgsl/parser_impl.h"
 #include "src/reader/wgsl/parser_impl_test_helper.h"
 
@@ -29,7 +30,7 @@ TEST_F(ParserImplTest, StructDecorationDecl_Parses) {
   EXPECT_TRUE(decos.matched);
   ASSERT_EQ(decos.value.size(), 1u);
   auto* struct_deco = decos.value[0]->As<ast::StructDecoration>();
-  EXPECT_TRUE(struct_deco->IsBlock());
+  EXPECT_TRUE(struct_deco->Is<ast::StructBlockDecoration>());
 }
 
 TEST_F(ParserImplTest, StructDecorationDecl_MissingAttrRight) {

src/reader/wgsl/parser_impl_struct_decoration_test.cc

@@ -13,6 +13,7 @@
 // limitations under the License.
 
 #include "gtest/gtest.h"
+#include "src/ast/struct_block_decoration.h"
 #include "src/ast/struct_decoration.h"
 #include "src/reader/wgsl/parser_impl.h"
 #include "src/reader/wgsl/parser_impl_test_helper.h"
@@ -45,7 +46,7 @@ TEST_P(StructDecorationTest, Parses) {
   ASSERT_NE(deco.value, nullptr);
   auto* struct_deco = deco.value->As<ast::StructDecoration>();
   ASSERT_NE(struct_deco, nullptr);
-  EXPECT_EQ(struct_deco->IsBlock(), params.is_block);
+  EXPECT_EQ(struct_deco->Is<ast::StructBlockDecoration>(), params.is_block);
 }
 INSTANTIATE_TEST_SUITE_P(ParserImplTest,
                          StructDecorationTest,