Move type_manager to the ast dir/namespace

First step to moving this to the `ast::Module`.

Also remove a bunch of redundant includes to `type_manager.h` as this is already included in `context.h`

Bug: tint:307
Bug: tint:337
Change-Id: Ic4baffa7b76ddefa29f56f758c25b1003ef40888
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/33665
Commit-Queue: Ben Clayton <bclayton@google.com>
Reviewed-by: David Neto <dneto@google.com>

src/ast/type_manager.cc

@@ -0,0 +1,40 @@
+// Copyright 2020 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/ast/type_manager.h"
+
+#include <utility>
+
+namespace tint {
+namespace ast {
+
+TypeManager::TypeManager() = default;
+
+TypeManager::~TypeManager() = default;
+
+void TypeManager::Reset() {
+  types_.clear();
+}
+
+ast::type::Type* TypeManager::Get(std::unique_ptr<ast::type::Type> type) {
+  auto name = type->type_name();
+
+  if (types_.find(name) == types_.end()) {
+    types_[name] = std::move(type);
+  }
+  return types_.find(name)->second.get();
+}
+
+}  // namespace ast
+}  // namespace tint

src/ast/type_manager.h

@@ -0,0 +1,65 @@
+// Copyright 2020 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_AST_TYPE_MANAGER_H_
+#define SRC_AST_TYPE_MANAGER_H_
+
+#include <memory>
+#include <string>
+#include <unordered_map>
+#include <utility>
+
+#include "src/ast/type/type.h"
+
+namespace tint {
+namespace ast {
+
+/// The type manager holds all the pointers to the known types.
+class TypeManager {
+ public:
+  TypeManager();
+  ~TypeManager();
+
+  /// Clears all registered types.
+  void Reset();
+
+  /// Get the given type from the type manager
+  /// @param type The type to register
+  /// @return the pointer to the registered type
+  ast::type::Type* Get(std::unique_ptr<ast::type::Type> type);
+
+  /// Get the given type `T` from the type manager
+  /// @param args the arguments to pass to the type constructor
+  /// @return the pointer to the registered type
+  template <typename T, typename... ARGS>
+  T* Get(ARGS&&... args) {
+    auto ty = Get(std::make_unique<T>(std::forward<ARGS>(args)...));
+    return static_cast<T*>(ty);
+  }
+
+  /// Returns the type map
+  /// @returns the mapping from name string to type.
+  const std::unordered_map<std::string, std::unique_ptr<ast::type::Type>>&
+  types() {
+    return types_;
+  }
+
+ private:
+  std::unordered_map<std::string, std::unique_ptr<ast::type::Type>> types_;
+};
+
+}  // namespace ast
+}  // namespace tint
+
+#endif  // SRC_AST_TYPE_MANAGER_H_

src/ast/type_manager_test.cc

@@ -0,0 +1,70 @@
+// Copyright 2020 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/ast/type_manager.h"
+
+#include "gtest/gtest.h"
+#include "src/ast/test_helper.h"
+#include "src/ast/type/i32_type.h"
+#include "src/ast/type/u32_type.h"
+
+namespace tint {
+namespace {
+
+using TypeManagerTest = testing::Test;
+
+TEST_F(TypeManagerTest, GetUnregistered) {
+  ast::TypeManager tm;
+  auto* t = tm.Get(std::make_unique<ast::type::I32Type>());
+  ASSERT_NE(t, nullptr);
+  EXPECT_TRUE(t->IsI32());
+}
+
+TEST_F(TypeManagerTest, GetSameTypeReturnsSamePtr) {
+  ast::TypeManager tm;
+  auto* t = tm.Get(std::make_unique<ast::type::I32Type>());
+  ASSERT_NE(t, nullptr);
+  EXPECT_TRUE(t->IsI32());
+
+  auto* t2 = tm.Get(std::make_unique<ast::type::I32Type>());
+  EXPECT_EQ(t, t2);
+}
+
+TEST_F(TypeManagerTest, GetDifferentTypeReturnsDifferentPtr) {
+  ast::TypeManager tm;
+  auto* t = tm.Get(std::make_unique<ast::type::I32Type>());
+  ASSERT_NE(t, nullptr);
+  EXPECT_TRUE(t->IsI32());
+
+  auto* t2 = tm.Get(std::make_unique<ast::type::U32Type>());
+  ASSERT_NE(t2, nullptr);
+  EXPECT_NE(t, t2);
+  EXPECT_TRUE(t2->IsU32());
+}
+
+TEST_F(TypeManagerTest, ResetClearsPreviousData) {
+  ast::TypeManager tm;
+  auto* t = tm.Get(std::make_unique<ast::type::I32Type>());
+  ASSERT_NE(t, nullptr);
+
+  EXPECT_FALSE(tm.types().empty());
+  tm.Reset();
+  EXPECT_TRUE(tm.types().empty());
+
+  auto* t2 = tm.Get(std::make_unique<ast::type::I32Type>());
+  ASSERT_NE(t2, nullptr);
+}
+
+}  // namespace
+}  // namespace tint