[cel-types] Add Protobuf definitions and codecs for CEL type definitions and aspects.

common/typedef/BUILD

@@ -0,0 +1,196 @@
+# Copyright 2026 Google LLC
+#
+# 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
+#
+#     https://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.
+
+load("@com_google_protobuf//bazel:cc_proto_library.bzl", "cc_proto_library")
+load("@com_google_protobuf//bazel:proto_library.bzl", "proto_library")
+load("@rules_cc//cc:cc_library.bzl", "cc_library")
+load("@rules_cc//cc:cc_test.bzl", "cc_test")
+
+package(default_visibility = ["//visibility:public"])
+
+licenses(["notice"])
+
+cc_library(
+    name = "typedef",
+    srcs = ["typedef.cc"],
+    hdrs = ["typedef.h"],
+    deps = [
+        "//common:ast",
+        "//common:constant",
+        "@com_google_absl//absl/base:core_headers",
+        "@com_google_absl//absl/base:nullability",
+        "@com_google_absl//absl/container:flat_hash_map",
+        "@com_google_absl//absl/functional:overload",
+        "@com_google_absl//absl/log:absl_check",
+        "@com_google_absl//absl/status",
+        "@com_google_absl//absl/strings",
+        "@com_google_absl//absl/strings:string_view",
+    ],
+)
+
+cc_test(
+    name = "typedef_test",
+    srcs = ["typedef_test.cc"],
+    deps = [
+        ":typedef",
+        "//common:ast",
+        "//common:constant",
+        "//internal:testing",
+        "@com_google_absl//absl/status",
+        "@com_google_absl//absl/status:status_matchers",
+    ],
+)
+
+proto_library(
+    name = "typedef_protos",
+    srcs = ["typedef.proto"],
+    deps = [
+        "@com_google_cel_spec//proto/cel/expr:checked_proto",
+        "@com_google_cel_spec//proto/cel/expr:syntax_proto",
+    ],
+)
+
+cc_proto_library(
+    name = "typedef_cc_proto",
+    deps = [":typedef_protos"],
+)
+
+cc_library(
+    name = "aspect_proto",
+    srcs = ["aspect_proto.cc"],
+    hdrs = ["aspect_proto.h"],
+    deps = [
+        ":typedef_cc_proto",
+        "@com_google_absl//absl/base:core_headers",
+        "@com_google_absl//absl/base:nullability",
+        "@com_google_absl//absl/container:flat_hash_map",
+        "@com_google_absl//absl/status",
+        "@com_google_absl//absl/status:statusor",
+        "@com_google_absl//absl/strings",
+        "@com_google_absl//absl/strings:string_view",
+    ],
+)
+
+cc_test(
+    name = "aspect_proto_test",
+    srcs = ["aspect_proto_test.cc"],
+    deps = [
+        ":aspect_proto",
+        ":typedef_cc_proto",
+        "//internal:testing",
+        "@com_google_absl//absl/status",
+        "@com_google_absl//absl/status:status_matchers",
+        "@com_google_absl//absl/strings:string_view",
+    ],
+)
+
+cc_library(
+    name = "typedef_proto",
+    srcs = ["typedef_proto.cc"],
+    hdrs = ["typedef_proto.h"],
+    deps = [
+        ":aspect_proto",
+        ":typedef",
+        ":typedef_cc_proto",
+        "//common:ast",
+        "//common:constant",
+        "//common/ast:constant_proto",
+        "//internal:status_macros",
+        "@com_google_absl//absl/base:nullability",
+        "@com_google_absl//absl/container:flat_hash_map",
+        "@com_google_absl//absl/status",
+        "@com_google_absl//absl/status:statusor",
+        "@com_google_absl//absl/types:span",
+        "@com_google_absl//absl/types:variant",
+        "@com_google_cel_spec//proto/cel/expr:checked_cc_proto",
+        "@com_google_protobuf//:struct_cc_proto",
+    ],
+)
+
+cc_library(
+    name = "proto_schema",
+    hdrs = ["proto_schema.h"],
+    deps = [
+        "@com_google_absl//absl/base:core_headers",
+        "@com_google_absl//absl/strings:string_view",
+    ],
+)
+
+proto_library(
+    name = "proto_schema_protos",
+    srcs = ["proto_schema.proto"],
+    deps = [":typedef_protos"],
+)
+
+cc_proto_library(
+    name = "proto_schema_cc_proto",
+    deps = [":proto_schema_protos"],
+)
+
+cc_library(
+    name = "proto_schema_proto",
+    srcs = ["proto_schema_proto.cc"],
+    hdrs = ["proto_schema_proto.h"],
+    deps = [
+        ":aspect_proto",
+        ":proto_schema",
+        ":proto_schema_cc_proto",
+        ":typedef_cc_proto",
+        "@com_google_absl//absl/base:nullability",
+        "@com_google_absl//absl/status",
+        "@com_google_absl//absl/status:statusor",
+        "@com_google_absl//absl/strings",
+        "@com_google_absl//absl/strings:string_view",
+    ],
+)
+
+cc_test(
+    name = "proto_schema_proto_test",
+    srcs = ["proto_schema_proto_test.cc"],
+    deps = [
+        ":aspect_proto",
+        ":proto_schema",
+        ":proto_schema_cc_proto",
+        ":proto_schema_proto",
+        ":typedef_cc_proto",
+        "//internal:testing",
+        "@com_google_absl//absl/status",
+        "@com_google_absl//absl/status:status_matchers",
+        "@com_google_protobuf//:protobuf",
+    ],
+)
+
+cc_test(
+    name = "typedef_proto_test",
+    srcs = ["typedef_proto_test.cc"],
+    data = [
+        "//common/typedef/testdata:typedef_testdata",
+    ],
+    deps = [
+        ":aspect_proto",
+        ":proto_schema_proto",
+        ":typedef",
+        ":typedef_cc_proto",
+        ":typedef_proto",
+        "//internal:proto_matchers",
+        "//internal:runfiles",
+        "//internal:testing",
+        "@com_google_absl//absl/status",
+        "@com_google_absl//absl/status:status_matchers",
+        "@com_google_absl//absl/status:statusor",
+        "@com_google_absl//absl/strings",
+        "@com_google_absl//absl/strings:string_view",
+        "@com_google_protobuf//:protobuf",
+    ],
+)

common/typedef/aspect_proto.cc

@@ -0,0 +1,95 @@
+// Copyright 2026 Google LLC
+//
+// 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
+//
+//     https://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 "common/typedef/aspect_proto.h"
+
+#include <any>
+#include <memory>
+#include <utility>
+#include <vector>
+
+#include "absl/base/nullability.h"
+#include "absl/status/status.h"
+#include "absl/status/statusor.h"
+#include "absl/strings/str_cat.h"
+#include "absl/strings/string_view.h"
+#include "common/typedef/typedef.pb.h"
+
+namespace cel {
+
+absl::StatusOr<std::any> AspectProto::DecodeStructProperties(
+    const types::Struct& proto) const {
+  return std::any();
+}
+
+absl::StatusOr<std::any> AspectProto::DecodeFieldProperties(
+    const types::Struct::Field& proto) const {
+  return std::any();
+}
+
+absl::StatusOr<std::any> AspectProto::DecodeEnumProperties(
+    const types::Enum& proto) const {
+  return std::any();
+}
+
+absl::StatusOr<std::any> AspectProto::DecodeEnumConstantProperties(
+    const types::Enum::EnumConstant& proto) const {
+  return std::any();
+}
+
+absl::Status AspectProto::EncodeStructProperties(
+    const std::any& properties, types::Struct* absl_nonnull proto) const {
+  return absl::UnimplementedError(absl::StrCat(
+      "Custom struct properties are not supported for aspect '", name(), "'"));
+}
+
+absl::Status AspectProto::EncodeFieldProperties(
+    const std::any& properties,
+    types::Struct::Field* absl_nonnull proto) const {
+  return absl::UnimplementedError(absl::StrCat(
+      "Custom field properties are not supported for aspect '", name(), "'"));
+}
+
+absl::Status AspectProto::EncodeEnumProperties(
+    const std::any& properties, types::Enum* absl_nonnull proto) const {
+  return absl::UnimplementedError(absl::StrCat(
+      "Custom enum properties are not supported for aspect '", name(), "'"));
+}
+
+absl::Status AspectProto::EncodeEnumConstantProperties(
+    const std::any& properties,
+    types::Enum::EnumConstant* absl_nonnull proto) const {
+  return absl::UnimplementedError(absl::StrCat(
+      "Custom enum constant properties are not supported for aspect '", name(),
+      "'"));
+}
+
+AspectProtoRegistry::AspectProtoRegistry(
+    std::vector<std::unique_ptr<const AspectProto>> aspects) {
+  aspects_.reserve(aspects.size());
+  for (std::unique_ptr<const AspectProto>& aspect : aspects) {
+    Add(std::move(aspect));
+  }
+}
+
+const AspectProto* absl_nullable AspectProtoRegistry::Find(
+    absl::string_view aspect_name) const {
+  auto it = aspects_.find(aspect_name);
+  if (it == aspects_.end()) {
+    return nullptr;
+  }
+  return it->second.get();
+}
+
+}  // namespace cel