Replace StructMemberDecoration::(Is|As) with Castable

Change-Id: I158194c60a9fe0ea2126ca31a92ad536c92a6388
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/34314
Reviewed-by: dan sinclair <dsinclair@chromium.org>

src/ast/struct_member.cc

@@ -41,7 +41,7 @@ StructMember::~StructMember() = default;
 
 bool StructMember::has_offset_decoration() const {
   for (auto* deco : decorations_) {
-    if (deco->IsOffset()) {
+    if (deco->Is<ast::StructMemberOffsetDecoration>()) {
       return true;
     }
   }
@@ -50,8 +50,8 @@ bool StructMember::has_offset_decoration() const {
 
 uint32_t StructMember::offset() const {
   for (auto* deco : decorations_) {
-    if (deco->IsOffset()) {
-      return deco->AsOffset()->offset();
+    if (auto* offset = deco->As<ast::StructMemberOffsetDecoration>()) {
+      return offset->offset();
     }
   }
   return 0;

src/ast/struct_member_decoration.cc

@@ -32,14 +32,5 @@ DecorationKind StructMemberDecoration::GetKind() const {
   return Kind;
 }
 
-bool StructMemberDecoration::IsOffset() const {
-  return false;
-}
-
-StructMemberOffsetDecoration* StructMemberDecoration::AsOffset() {
-  assert(IsOffset());
-  return static_cast<StructMemberOffsetDecoration*>(this);
-}
-
 }  // namespace ast
 }  // namespace tint

src/ast/struct_member_decoration.h

@@ -24,8 +24,6 @@
 namespace tint {
 namespace ast {
 
-class StructMemberOffsetDecoration;
-
 /// A decoration attached to a struct member
 class StructMemberDecoration
     : public Castable<StructMemberDecoration, Decoration> {
@@ -38,12 +36,6 @@ class StructMemberDecoration
   /// @return the decoration kind
   DecorationKind GetKind() const override;
 
-  /// @returns true if this is an offset decoration
-  virtual bool IsOffset() const;
-
-  /// @returns the decoration as an offset decoration
-  StructMemberOffsetDecoration* AsOffset();
-
  protected:
   /// Constructor
   /// @param source the source of this decoration

src/ast/struct_member_offset_decoration.cc

@@ -21,10 +21,6 @@ StructMemberOffsetDecoration::StructMemberOffsetDecoration(uint32_t offset,
                                                            const Source& source)
     : Base(source), offset_(offset) {}
 
-bool StructMemberOffsetDecoration::IsOffset() const {
-  return true;
-}
-
 StructMemberOffsetDecoration::~StructMemberOffsetDecoration() = default;
 
 void StructMemberOffsetDecoration::to_str(std::ostream& out,

src/ast/struct_member_offset_decoration.h

@@ -34,9 +34,6 @@ class StructMemberOffsetDecoration
   StructMemberOffsetDecoration(uint32_t offset, const Source& source);
   ~StructMemberOffsetDecoration() override;
 
-  /// @returns true if this is an offset decoration
-  bool IsOffset() const override;
-
   /// @returns the offset value
   uint32_t offset() const { return offset_; }
 

src/ast/struct_member_offset_decoration_test.cc

@@ -29,7 +29,7 @@ TEST_F(StructMemberOffsetDecorationTest, Creation) {
 
 TEST_F(StructMemberOffsetDecorationTest, Is) {
   StructMemberOffsetDecoration d{2, Source{}};
-  EXPECT_TRUE(d.IsOffset());
+  EXPECT_TRUE(d.Is<ast::StructMemberOffsetDecoration>());
 }
 
 }  // namespace

src/ast/struct_member_test.cc

@@ -36,7 +36,7 @@ TEST_F(StructMemberTest, Creation) {
   EXPECT_EQ(st.name(), "a");
   EXPECT_EQ(st.type(), &i32);
   EXPECT_EQ(st.decorations().size(), 1u);
-  EXPECT_TRUE(st.decorations()[0]->IsOffset());
+  EXPECT_TRUE(st.decorations()[0]->Is<ast::StructMemberOffsetDecoration>());
   EXPECT_EQ(st.source().range.begin.line, 0u);
   EXPECT_EQ(st.source().range.begin.column, 0u);
   EXPECT_EQ(st.source().range.end.line, 0u);

src/reader/spirv/parser_impl_convert_member_decoration_test.cc

@@ -63,8 +63,8 @@ TEST_F(SpvParserTest, ConvertMemberDecoration_Offset) {
 
   auto* result = p->ConvertMemberDecoration(1, 1, {SpvDecorationOffset, 8});
   ASSERT_NE(result, nullptr);
-  EXPECT_TRUE(result->IsOffset());
-  auto* offset_deco = result->AsOffset();
+  EXPECT_TRUE(result->Is<ast::StructMemberOffsetDecoration>());
+  auto* offset_deco = result->As<ast::StructMemberOffsetDecoration>();
   ASSERT_NE(offset_deco, nullptr);
   EXPECT_EQ(offset_deco->offset(), 8u);
   EXPECT_TRUE(p->error().empty());

src/reader/wgsl/parser_impl_struct_member_decoration_decl_test.cc

@@ -50,7 +50,7 @@ TEST_F(ParserImplTest, StructMemberDecorationDecl_Single) {
   ASSERT_EQ(decos.value.size(), 1u);
   auto* deco = decos.value[0]->As<ast::StructMemberDecoration>();
   ASSERT_NE(deco, nullptr);
-  EXPECT_TRUE(deco->IsOffset());
+  EXPECT_TRUE(deco->Is<ast::StructMemberOffsetDecoration>());
 }
 
 TEST_F(ParserImplTest, StructMemberDecorationDecl_InvalidDecoration) {

src/reader/wgsl/parser_impl_struct_member_decoration_test.cc

@@ -32,9 +32,9 @@ TEST_F(ParserImplTest, StructMemberDecoration_Offset) {
 
   auto* member_deco = deco.value->As<ast::StructMemberDecoration>();
   ASSERT_NE(member_deco, nullptr);
-  ASSERT_TRUE(member_deco->IsOffset());
+  ASSERT_TRUE(member_deco->Is<ast::StructMemberOffsetDecoration>());
 
-  auto* o = member_deco->AsOffset();
+  auto* o = member_deco->As<ast::StructMemberOffsetDecoration>();
   EXPECT_EQ(o->offset(), 4u);
 }
 

src/reader/wgsl/parser_impl_struct_member_test.cc

@@ -68,8 +68,10 @@ TEST_F(ParserImplTest, StructMember_ParsesWithDecoration) {
   EXPECT_EQ(m->name(), "a");
   EXPECT_EQ(m->type(), i32);
   EXPECT_EQ(m->decorations().size(), 1u);
-  EXPECT_TRUE(m->decorations()[0]->IsOffset());
-  EXPECT_EQ(m->decorations()[0]->AsOffset()->offset(), 2u);
+  EXPECT_TRUE(m->decorations()[0]->Is<ast::StructMemberOffsetDecoration>());
+  EXPECT_EQ(
+      m->decorations()[0]->As<ast::StructMemberOffsetDecoration>()->offset(),
+      2u);
 
   ASSERT_EQ(m->source().range.begin.line, 1u);
   ASSERT_EQ(m->source().range.begin.column, 15u);
@@ -97,10 +99,14 @@ TEST_F(ParserImplTest, StructMember_ParsesWithMultipleDecorations) {
   EXPECT_EQ(m->name(), "a");
   EXPECT_EQ(m->type(), i32);
   EXPECT_EQ(m->decorations().size(), 2u);
-  EXPECT_TRUE(m->decorations()[0]->IsOffset());
-  EXPECT_EQ(m->decorations()[0]->AsOffset()->offset(), 2u);
-  EXPECT_TRUE(m->decorations()[1]->IsOffset());
-  EXPECT_EQ(m->decorations()[1]->AsOffset()->offset(), 4u);
+  EXPECT_TRUE(m->decorations()[0]->Is<ast::StructMemberOffsetDecoration>());
+  EXPECT_EQ(
+      m->decorations()[0]->As<ast::StructMemberOffsetDecoration>()->offset(),
+      2u);
+  EXPECT_TRUE(m->decorations()[1]->Is<ast::StructMemberOffsetDecoration>());
+  EXPECT_EQ(
+      m->decorations()[1]->As<ast::StructMemberOffsetDecoration>()->offset(),
+      4u);
 
   ASSERT_EQ(m->source().range.begin.line, 2u);
   ASSERT_EQ(m->source().range.begin.column, 15u);

src/writer/msl/generator_impl.cc

@@ -218,8 +218,8 @@ uint32_t GeneratorImpl::calculate_alignment_size(ast::type::Type* type) {
     // Offset decorations in WGSL must be in increasing order.
     for (auto* mem : stct->members()) {
       for (auto* deco : mem->decorations()) {
-        if (deco->IsOffset()) {
-          count = deco->AsOffset()->offset();
+        if (auto* offset = deco->As<ast::StructMemberOffsetDecoration>()) {
+          count = offset->offset();
         }
       }
       auto align = calculate_alignment_size(mem->type());
@@ -1941,8 +1941,8 @@ bool GeneratorImpl::EmitStructType(const ast::type::StructType* str) {
   for (auto* mem : str->impl()->members()) {
     make_indent();
     for (auto* deco : mem->decorations()) {
-      if (deco->IsOffset()) {
-        uint32_t offset = deco->AsOffset()->offset();
+      if (auto* o = deco->As<ast::StructMemberOffsetDecoration>()) {
+        uint32_t offset = o->offset();
         if (offset != current_offset) {
           out_ << "int8_t pad_" << pad_count << "[" << (offset - current_offset)
                << "];" << std::endl;

src/writer/spirv/builder.cc

@@ -2696,11 +2696,11 @@ uint32_t Builder::GenerateStructMember(uint32_t struct_id,
 
   bool has_layout = false;
   for (auto* deco : member->decorations()) {
-    if (deco->IsOffset()) {
+    if (auto* offset = deco->As<ast::StructMemberOffsetDecoration>()) {
       push_annot(spv::Op::OpMemberDecorate,
                  {Operand::Int(struct_id), Operand::Int(idx),
                   Operand::Int(SpvDecorationOffset),
-                  Operand::Int(deco->AsOffset()->offset())});
+                  Operand::Int(offset->offset())});
       has_layout = true;
     } else {
       error_ = "unknown struct member decoration";

src/writer/wgsl/generator_impl.cc

@@ -580,8 +580,10 @@ bool GeneratorImpl::EmitStructType(const ast::type::StructType* str) {
       make_indent();
 
       // TODO(dsinclair): Split this out when we have more then one
-      assert(deco->IsOffset());
-      out_ << "[[offset(" << deco->AsOffset()->offset() << ")]]" << std::endl;
+      assert(deco->Is<ast::StructMemberOffsetDecoration>());
+      out_ << "[[offset("
+           << deco->As<ast::StructMemberOffsetDecoration>()->offset() << ")]]"
+           << std::endl;
     }
     make_indent();
     out_ << mem->name() << " : ";