feat: DGR-002 - Adopt the versioned gRPC Shard protocol

packages/node/native/CMakeLists.txt

@@ -0,0 +1,74 @@
+# Native Shard protocol: C++ schema generation, build wiring and conformance test.
+#
+# The C++ stubs are generated into the build tree at configure time — they are
+# never committed. A C++ consumer already needs a toolchain, so committing
+# generated C++ would only create a second copy of the schema that can rot.
+#
+# gRPC C++ is optional here on purpose. The conformance test only needs message
+# types, so the schema can be verified on a machine that has protobuf but not
+# the gRPC C++ stack. When gRPC *is* found, the service stubs are generated too
+# and exported as `shard_runtime_grpc` for the worker (DGR-008) to link.
+#
+# Build:
+#   cmake -S packages/node/native -B build/native -DCMAKE_PREFIX_PATH=<protobuf-install>
+#   cmake --build build/native -j
+#   ctest --test-dir build/native --output-on-failure
+#
+# `scripts/bootstrap_native_toolchain.sh` builds a protobuf install from source
+# when the system has none.
+
+cmake_minimum_required(VERSION 3.24)
+project(meshnet_shard_protocol CXX)
+
+set(CMAKE_CXX_STANDARD 17)
+set(CMAKE_CXX_STANDARD_REQUIRED ON)
+
+find_package(protobuf CONFIG REQUIRED)
+find_package(gRPC CONFIG QUIET)
+
+set(SHARD_PROTO "${CMAKE_CURRENT_SOURCE_DIR}/proto/shard_runtime.proto")
+
+# Message types: always available.
+add_library(shard_runtime_proto STATIC "${SHARD_PROTO}")
+target_link_libraries(shard_runtime_proto PUBLIC protobuf::libprotobuf)
+target_include_directories(shard_runtime_proto PUBLIC "${CMAKE_CURRENT_BINARY_DIR}")
+protobuf_generate(
+  TARGET shard_runtime_proto
+  LANGUAGE cpp
+  IMPORT_DIRS "${CMAKE_CURRENT_SOURCE_DIR}/proto"
+  PROTOC_OUT_DIR "${CMAKE_CURRENT_BINARY_DIR}"
+)
+
+# Service stubs: only when the gRPC C++ stack is present.
+if(gRPC_FOUND)
+  add_library(shard_runtime_grpc STATIC "${SHARD_PROTO}")
+  target_link_libraries(shard_runtime_grpc PUBLIC shard_runtime_proto gRPC::grpc++)
+  target_include_directories(shard_runtime_grpc PUBLIC "${CMAKE_CURRENT_BINARY_DIR}")
+  protobuf_generate(
+    TARGET shard_runtime_grpc
+    LANGUAGE grpc
+    GENERATE_EXTENSIONS .grpc.pb.h .grpc.pb.cc
+    PLUGIN "protoc-gen-grpc=$<TARGET_FILE:gRPC::grpc_cpp_plugin>"
+    IMPORT_DIRS "${CMAKE_CURRENT_SOURCE_DIR}/proto"
+    PROTOC_OUT_DIR "${CMAKE_CURRENT_BINARY_DIR}"
+  )
+  message(STATUS "gRPC C++ found: building ShardRuntime service stubs")
+else()
+  message(STATUS "gRPC C++ not found: building message types only "
+                 "(sufficient for the conformance test)")
+endif()
+
+enable_testing()
+
+add_executable(shard_protocol_conformance tests/test_shard_protocol_conformance.cpp)
+target_link_libraries(shard_protocol_conformance PRIVATE shard_runtime_proto)
+
+# The test asserts against the same committed vectors the Python test uses, and
+# writes its own re-serialization back out so Python can prove the two languages
+# agree byte-for-byte.
+add_test(
+  NAME shard_protocol_conformance
+  COMMAND shard_protocol_conformance
+          "${CMAKE_CURRENT_SOURCE_DIR}/testdata"
+          "${CMAKE_CURRENT_BINARY_DIR}"
+)