Move sampler to type.

This CL moves the sampler from sem to type and updates the namespace.

Bug: tint:1718
Change-Id: I22d228df5d24e154dbebecb43e7c6730475e08d2
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/113283
Reviewed-by: Ben Clayton <bclayton@google.com>
Commit-Queue: Dan Sinclair <dsinclair@chromium.org>
Kokoro: Kokoro <noreply+kokoro@google.com>

src/tint/type/sampler.cc

@@ -0,0 +1,45 @@
+// Copyright 2022 The Tint Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "src/tint/type/sampler.h"
+
+#include "src/tint/program_builder.h"
+#include "src/tint/utils/hash.h"
+
+TINT_INSTANTIATE_TYPEINFO(tint::type::Sampler);
+
+namespace tint::type {
+
+Sampler::Sampler(ast::SamplerKind kind) : Base(type::TypeFlags{}), kind_(kind) {}
+
+Sampler::Sampler(Sampler&&) = default;
+
+Sampler::~Sampler() = default;
+
+size_t Sampler::Hash() const {
+    return utils::Hash(TypeInfo::Of<Sampler>().full_hashcode, kind_);
+}
+
+bool Sampler::Equals(const type::Type& other) const {
+    if (auto* o = other.As<Sampler>()) {
+        return o->kind_ == kind_;
+    }
+    return false;
+}
+
+std::string Sampler::FriendlyName(const SymbolTable&) const {
+    return kind_ == ast::SamplerKind::kSampler ? "sampler" : "sampler_comparison";
+}
+
+}  // namespace tint::type

src/tint/type/sampler.h

@@ -0,0 +1,59 @@
+// Copyright 2022 The Tint Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef SRC_TINT_TYPE_SAMPLER_H_
+#define SRC_TINT_TYPE_SAMPLER_H_
+
+#include <string>
+
+#include "src/tint/ast/sampler.h"
+#include "src/tint/type/type.h"
+
+namespace tint::type {
+
+/// A sampler type.
+class Sampler final : public Castable<Sampler, type::Type> {
+  public:
+    /// Constructor
+    /// @param kind the kind of sampler
+    explicit Sampler(ast::SamplerKind kind);
+    /// Move constructor
+    Sampler(Sampler&&);
+    ~Sampler() override;
+
+    /// @returns a hash of the type.
+    size_t Hash() const override;
+
+    /// @param other the other type to compare against
+    /// @returns true if the this type is equal to the given type
+    bool Equals(const Type& other) const override;
+
+    /// @returns the sampler type
+    ast::SamplerKind kind() const { return kind_; }
+
+    /// @returns true if this is a comparison sampler
+    bool IsComparison() const { return kind_ == ast::SamplerKind::kComparisonSampler; }
+
+    /// @param symbols the program's symbol table
+    /// @returns the name for this type that closely resembles how it would be
+    /// declared in WGSL.
+    std::string FriendlyName(const SymbolTable& symbols) const override;
+
+  private:
+    ast::SamplerKind const kind_;
+};
+
+}  // namespace tint::type
+
+#endif  // SRC_TINT_TYPE_SAMPLER_H_

src/tint/type/sampler_test.cc

@@ -0,0 +1,69 @@
+// Copyright 2022 The Tint Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "src/tint/type/sampler.h"
+#include "src/tint/type/test_helper.h"
+#include "src/tint/type/texture.h"
+
+namespace tint::type {
+namespace {
+
+using SamplerTest = TestHelper;
+
+TEST_F(SamplerTest, Creation) {
+    auto* a = create<Sampler>(ast::SamplerKind::kSampler);
+    auto* b = create<Sampler>(ast::SamplerKind::kSampler);
+    auto* c = create<Sampler>(ast::SamplerKind::kComparisonSampler);
+
+    EXPECT_EQ(a->kind(), ast::SamplerKind::kSampler);
+    EXPECT_EQ(c->kind(), ast::SamplerKind::kComparisonSampler);
+
+    EXPECT_FALSE(a->IsComparison());
+    EXPECT_TRUE(c->IsComparison());
+
+    EXPECT_EQ(a, b);
+    EXPECT_NE(a, c);
+}
+
+TEST_F(SamplerTest, Hash) {
+    auto* a = create<Sampler>(ast::SamplerKind::kSampler);
+    auto* b = create<Sampler>(ast::SamplerKind::kSampler);
+    auto* c = create<Sampler>(ast::SamplerKind::kComparisonSampler);
+
+    EXPECT_EQ(a->Hash(), b->Hash());
+    EXPECT_NE(a->Hash(), c->Hash());
+}
+
+TEST_F(SamplerTest, Equals) {
+    auto* a = create<Sampler>(ast::SamplerKind::kSampler);
+    auto* b = create<Sampler>(ast::SamplerKind::kSampler);
+    auto* c = create<Sampler>(ast::SamplerKind::kComparisonSampler);
+
+    EXPECT_TRUE(a->Equals(*b));
+    EXPECT_FALSE(a->Equals(*c));
+    EXPECT_FALSE(a->Equals(sem::Void{}));
+}
+
+TEST_F(SamplerTest, FriendlyNameSampler) {
+    Sampler s{ast::SamplerKind::kSampler};
+    EXPECT_EQ(s.FriendlyName(Symbols()), "sampler");
+}
+
+TEST_F(SamplerTest, FriendlyNameComparisonSampler) {
+    Sampler s{ast::SamplerKind::kComparisonSampler};
+    EXPECT_EQ(s.FriendlyName(Symbols()), "sampler_comparison");
+}
+
+}  // namespace
+}  // namespace tint::type

src/tint/type/type.cc

@@ -24,10 +24,10 @@
 #include "src/tint/sem/matrix.h"
 #include "src/tint/sem/pointer.h"
 #include "src/tint/sem/reference.h"
-#include "src/tint/sem/sampler.h"
 #include "src/tint/sem/struct.h"
 #include "src/tint/sem/u32.h"
 #include "src/tint/sem/vector.h"
+#include "src/tint/type/sampler.h"
 #include "src/tint/type/texture.h"
 
 TINT_INSTANTIATE_TYPEINFO(tint::type::Type);
@@ -172,7 +172,7 @@ bool Type::is_numeric_scalar_or_vector() const {
 }
 
 bool Type::is_handle() const {
-    return IsAnyOf<sem::Sampler, type::Texture>();
+    return IsAnyOf<type::Sampler, type::Texture>();
 }
 
 bool Type::HoldsAbstract() const {