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Add helper for building consistent descriptor pool.
PiperOrigin-RevId: 739215894
1 parent ccc9a70 commit 87af8c8

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‎tools/BUILD‎

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@@ -121,3 +121,32 @@ cc_test(
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"@com_google_protobuf//:protobuf",
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],
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)
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cc_library(
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name = "descriptor_pool_builder",
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srcs = ["descriptor_pool_builder.cc"],
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hdrs = ["descriptor_pool_builder.h"],
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deps = [
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"//common:minimal_descriptor_database",
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"//internal:status_macros",
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"@com_google_absl//absl/base:nullability",
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"@com_google_absl//absl/container:flat_hash_set",
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"@com_google_absl//absl/status",
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"@com_google_absl//absl/strings",
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"@com_google_absl//absl/types:span",
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"@com_google_protobuf//:protobuf",
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],
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)
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cc_test(
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name = "descriptor_pool_builder_test",
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srcs = ["descriptor_pool_builder_test.cc"],
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deps = [
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":descriptor_pool_builder",
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"//internal:testing",
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"@com_google_absl//absl/status",
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"@com_google_absl//absl/status:status_matchers",
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"@com_google_cel_spec//proto/cel/expr/conformance/proto2:test_all_types_cc_proto",
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"@com_google_protobuf//:protobuf",
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],
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)

‎tools/descriptor_pool_builder.cc‎

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// Copyright 2025 Google LLC
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// https://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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#include "tools/descriptor_pool_builder.h"
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#include <memory>
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#include <vector>
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#include "google/protobuf/descriptor.pb.h"
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#include "absl/base/nullability.h"
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#include "absl/container/flat_hash_set.h"
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#include "absl/status/status.h"
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#include "absl/strings/str_cat.h"
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#include "absl/types/span.h"
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#include "common/minimal_descriptor_database.h"
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#include "internal/status_macros.h"
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#include "google/protobuf/descriptor.h"
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namespace cel {
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namespace {
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absl::Status FindDeps(
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std::vector<const google::protobuf::FileDescriptor*>& to_resolve,
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absl::flat_hash_set<const google::protobuf::FileDescriptor*>& resolved,
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DescriptorPoolBuilder& builder) {
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while (!to_resolve.empty()) {
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const auto* file = to_resolve.back();
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to_resolve.pop_back();
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if (resolved.contains(file)) {
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continue;
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}
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google::protobuf::FileDescriptorProto file_proto;
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file->CopyTo(&file_proto);
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// Note: order doesn't matter here as long as all the cross references are
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// correct in the final database.
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CEL_RETURN_IF_ERROR(builder.AddFileDescriptor(file_proto));
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resolved.insert(file);
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for (int i = 0; i < file->dependency_count(); ++i) {
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to_resolve.push_back(file->dependency(i));
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}
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}
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return absl::OkStatus();
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}
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} // namespace
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DescriptorPoolBuilder::StateHolder::StateHolder(
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google::protobuf::DescriptorDatabase* base)
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: base(base), merged(base, &extensions), pool(&merged) {}
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DescriptorPoolBuilder::DescriptorPoolBuilder()
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: state_(std::make_shared<DescriptorPoolBuilder::StateHolder>(
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cel::GetMinimalDescriptorDatabase())) {}
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std::shared_ptr<const google::protobuf::DescriptorPool>
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DescriptorPoolBuilder::Build() && {
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auto alias =
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std::shared_ptr<const google::protobuf::DescriptorPool>(state_, &state_->pool);
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state_.reset();
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return alias;
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}
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absl::Status DescriptorPoolBuilder::AddTransitiveDescriptorSet(
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absl::Nonnull<const google::protobuf::Descriptor*> desc) {
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absl::flat_hash_set<const google::protobuf::FileDescriptor*> resolved;
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std::vector<const google::protobuf::FileDescriptor*> to_resolve{desc->file()};
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return FindDeps(to_resolve, resolved, *this);
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}
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absl::Status DescriptorPoolBuilder::AddTransitiveDescriptorSet(
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absl::Span<absl::Nonnull<const google::protobuf::Descriptor*>> descs) {
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absl::flat_hash_set<const google::protobuf::FileDescriptor*> resolved;
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std::vector<absl::Nonnull<const google::protobuf::FileDescriptor*>> to_resolve;
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to_resolve.reserve(descs.size());
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for (const google::protobuf::Descriptor* desc : descs) {
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to_resolve.push_back(desc->file());
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}
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return FindDeps(to_resolve, resolved, *this);
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}
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absl::Status DescriptorPoolBuilder::AddFileDescriptor(
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const google::protobuf::FileDescriptorProto& file) {
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if (!state_->extensions.Add(file)) {
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return absl::InvalidArgumentError(
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absl::StrCat("proto descriptor conflict: ", file.name()));
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}
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return absl::OkStatus();
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}
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absl::Status DescriptorPoolBuilder::AddFileDescriptorSet(
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const google::protobuf::FileDescriptorSet& file) {
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for (const auto& file : file.file()) {
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CEL_RETURN_IF_ERROR(AddFileDescriptor(file));
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}
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return absl::OkStatus();
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}
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} // namespace cel

‎tools/descriptor_pool_builder.h‎

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// Copyright 2025 Google LLC
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// https://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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#ifndef THIRD_PARTY_CEL_CPP_TOOLS_DESCRIPTOR_POOL_BUILDER_H_
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#define THIRD_PARTY_CEL_CPP_TOOLS_DESCRIPTOR_POOL_BUILDER_H_
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#include <memory>
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#include <utility>
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#include "google/protobuf/descriptor.pb.h"
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#include "absl/base/nullability.h"
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#include "absl/status/status.h"
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#include "absl/types/span.h"
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#include "google/protobuf/descriptor.h"
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#include "google/protobuf/descriptor_database.h"
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namespace cel {
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// A helper class for building a descriptor pool from a set proto file
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// descriptors. Manages lifetime for the descriptor databases backing
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// the pool.
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//
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// Client must ensure that types are not added multiple times.
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//
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// Note: in the constructed pool, the definitions for the required types for
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// CEL will shadow any added to the builder. Clients should not modify types
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// from the google.protobuf package in general, but if they do the behavior of
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// the constructed descriptor pool will be inconsistent.
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class DescriptorPoolBuilder {
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public:
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DescriptorPoolBuilder();
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DescriptorPoolBuilder& operator=(const DescriptorPoolBuilder&) = delete;
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DescriptorPoolBuilder(const DescriptorPoolBuilder&) = delete;
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DescriptorPoolBuilder& operator=(const DescriptorPoolBuilder&&) = delete;
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DescriptorPoolBuilder(DescriptorPoolBuilder&&) = delete;
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~DescriptorPoolBuilder() = default;
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// Returns a shared pointer to the new descriptor pool that manages the
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// underlying descriptor databases backing the pool.
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//
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// Consumes the builder instance. It is unsafe to make any further changes
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// to the descriptor databases after accessing the pool.
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std::shared_ptr<const google::protobuf::DescriptorPool> Build() &&;
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// Utility for adding the transitive dependencies of a message with a linked
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// descriptor.
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absl::Status AddTransitiveDescriptorSet(
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absl::Nonnull<const google::protobuf::Descriptor*> desc);
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absl::Status AddTransitiveDescriptorSet(
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absl::Span<absl::Nonnull<const google::protobuf::Descriptor*>>);
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// Adds a file descriptor set to the pool. Client must ensure that all
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// dependencies are satisfied and that files are not added multiple times.
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absl::Status AddFileDescriptorSet(const google::protobuf::FileDescriptorSet& files);
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// Adds a single proto file descriptor set to the pool. Client must ensure
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// that all dependencies are satisfied and that files are not added multiple
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// times.
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absl::Status AddFileDescriptor(const google::protobuf::FileDescriptorProto& file);
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private:
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struct StateHolder {
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explicit StateHolder(google::protobuf::DescriptorDatabase* base);
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google::protobuf::DescriptorDatabase* base;
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google::protobuf::SimpleDescriptorDatabase extensions;
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google::protobuf::MergedDescriptorDatabase merged;
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google::protobuf::DescriptorPool pool;
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};
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explicit DescriptorPoolBuilder(std::shared_ptr<StateHolder> state)
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: state_(std::move(state)) {}
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std::shared_ptr<StateHolder> state_;
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};
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} // namespace cel
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#endif // THIRD_PARTY_CEL_CPP_TOOLS_DESCRIPTOR_POOL_BUILDER_H_

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