Add CMake support

.github/workflows/pre-commit.yml

@@ -1,9 +1,11 @@
 name: pre-commit
 
 on:
+  workflow_dispatch:
   pull_request:
   push:
-    branches: [main]
+    branches:
+      - main
 
 jobs:
   pre-commit:

.github/workflows/ubuntu-build.yml

@@ -0,0 +1,48 @@
+name: ubuntu-build
+
+on:
+  workflow_dispatch:
+  pull_request:
+  push:
+    branches:
+      - main
+
+concurrency:
+  group: ci-${{github.workflow}}-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  build:
+    runs-on: ubuntu-22.04
+    name: ubuntu-build
+    steps:
+      - name: Show env
+        run: env
+
+      - name: Checkout
+        uses: actions/checkout@v3
+
+      - name: Install Build Dependencies
+        shell: bash
+        run: |
+          sudo apt update && sudo apt install --no-install-recommends -y \
+          cmake \
+          make
+
+      - name: Show Python version and platform info
+        run: |
+          python --version
+          python -m platform
+
+      - name: Show CMake version
+        run: cmake --version
+
+      - name: CMake Configure
+        shell: bash
+        run: |
+          cmake -S . -B build -DCMAKE_VERBOSE_MAKEFILE=ON
+
+      - name: CMake Build
+        shell: bash
+        run: |
+          cmake --build build -j$(nproc)

CMakeLists.txt

@@ -0,0 +1,138 @@
+cmake_minimum_required(VERSION 3.18)
+list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/cmake")
+
+project(pybind11_protobuf)
+
+if(MSVC)
+  set(CMAKE_CXX_STANDARD 20)
+else()
+  set(CMAKE_CXX_STANDARD 17)
+endif()
+set(CMAKE_CXX_STANDARD_REQUIRED ON)
+set(CMAKE_CXX_EXTENSIONS OFF)
+
+set(CMAKE_POSITION_INDEPENDENT_CODE ON)
+
+# ============================================================================
+# Options
+
+option(BUILD_TESTS "Build tests." OFF)
+
+# ============================================================================
+# Find Python
+
+find_package(Python COMPONENTS Interpreter Development)
+
+# ============================================================================
+# Build dependencies
+
+set(_absl_repository "https://github.com/abseil/abseil-cpp.git")
+set(_absl_version 20220623.1)
+set(_absl_tag 20220623.1)
+
+set(_protobuf_repository "https://github.com/protocolbuffers/protobuf.git")
+set(_protobuf_version 21.5)
+set(_protobuf_tag v21.5)
+
+set(_pybind11_repository "https://github.com/pybind/pybind11.git")
+set(_pybind11_version 2.10)
+set(_pybind11_tag v2.10.1)
+
+add_subdirectory(cmake/dependencies dependencies)
+
+# ============================================================================
+# pybind11_proto_utils pybind11 extension module
+pybind11_add_module(
+  pybind11_proto_utils MODULE pybind11_protobuf/proto_utils.cc
+  pybind11_protobuf/proto_utils.h)
+
+target_link_libraries(
+  pybind11_proto_utils PRIVATE absl::strings protobuf::libprotobuf
+                               ${Python_LIBRARIES})
+
+target_include_directories(
+  pybind11_proto_utils PRIVATE ${PROJECT_SOURCE_DIR} ${protobuf_INCLUDE_DIRS}
+                               ${protobuf_SOURCE_DIR} ${pybind11_INCLUDE_DIRS})
+
+# ============================================================================
+# pybind11_native_proto_caster shared library
+add_library(
+  pybind11_native_proto_caster SHARED
+  # bazel: pybind_library: native_proto_caster
+  pybind11_protobuf/native_proto_caster.h
+  # bazel: pybind_library: enum_type_caster
+  pybind11_protobuf/enum_type_caster.h
+  # bazel: pybind_library: proto_cast_util
+  pybind11_protobuf/proto_cast_util.cc
+  pybind11_protobuf/proto_cast_util.h
+  pybind11_protobuf/proto_caster_impl.h
+  # bazel: cc_library::check_unknown_fields
+  pybind11_protobuf/check_unknown_fields.cc
+  pybind11_protobuf/check_unknown_fields.h)
+
+target_link_libraries(
+  pybind11_native_proto_caster
+  absl::flat_hash_map
+  absl::flat_hash_set
+  absl::hash
+  absl::strings
+  absl::optional
+  protobuf::libprotobuf
+  pybind11::pybind11
+  ${Python_LIBRARIES})
+
+target_include_directories(
+  pybind11_native_proto_caster
+  PRIVATE ${PROJECT_SOURCE_DIR} ${protobuf_INCLUDE_DIRS} ${protobuf_SOURCE_DIR}
+          ${pybind11_INCLUDE_DIRS})
+
+# ============================================================================
+# pybind11_wrapped_proto_caster shared library
+add_library(
+  pybind11_wrapped_proto_caster SHARED
+  # bazel: pybind_library: wrapped_proto_caster
+  pybind11_protobuf/wrapped_proto_caster.h
+  # bazel: pybind_library: proto_cast_util
+  pybind11_protobuf/proto_cast_util.cc
+  pybind11_protobuf/proto_cast_util.h
+  pybind11_protobuf/proto_caster_impl.h
+  # bazel: cc_library: check_unknown_fields
+  pybind11_protobuf/check_unknown_fields.cc
+  pybind11_protobuf/check_unknown_fields.h)
+
+target_link_libraries(
+  pybind11_wrapped_proto_caster
+  absl::flat_hash_map
+  absl::flat_hash_set
+  absl::hash
+  absl::strings
+  absl::optional
+  protobuf::libprotobuf
+  pybind11::pybind11
+  ${Python_LIBRARIES})
+
+target_include_directories(
+  pybind11_wrapped_proto_caster
+  PRIVATE ${PROJECT_SOURCE_DIR} ${protobuf_INCLUDE_DIRS} ${protobuf_SOURCE_DIR}
+          ${pybind11_INCLUDE_DIRS})
+
+# TODO set defines PYBIND11_PROTOBUF_ENABLE_PYPROTO_API see: bazel:
+# pybind_library: proto_cast_util
+
+# bazel equivs. checklist
+#
+# bazel: pybind_library: enum_type_caster - enum_type_caster.h
+#
+# bazel: pybind_library: native_proto_caster - native_proto_caster.h
+#
+# check_unknown_fields enum_type_caster proto_cast_util
+#
+# bazel: pybind_library: proto_cast_util - proto_cast_util.cc -
+# proto_cast_util.h - proto_caster_impl.h
+#
+# check_unknown_fields
+#
+# bazel: pybind_library: wrapped_proto_caster - wrapped_proto_caster.h
+#
+# proto_cast_util
+#

cmake/dependencies/CMakeLists.txt

@@ -0,0 +1,64 @@
+include(FetchContent)
+
+# ============================================================================
+# Declare all dependencies first
+
+find_package(absl ${_absl_version} EXACT QUIET)
+if(NOT absl_FOUND)
+  set(ABSL_PROPAGATE_CXX_STD ON)
+  FetchContent_Declare(
+    absl
+    GIT_REPOSITORY ${_absl_repository}
+    GIT_TAG ${_absl_tag})
+endif()
+
+# https://stackoverflow.com/questions/63309544/cmake-protobuf-external-to-application-code
+# https://cmake.org/cmake/help/latest/policy/CMP0077.html
+# https://gitlab.kitware.com/cmake/cmake/-/merge_requests/7565/diffs
+find_package(Protobuf ${_protobuf_version} EXACT QUIET)
+if(NOT Protobuf_FOUND)
+  set(protobuf_BUILD_TESTS
+      OFF
+      CACHE INTERNAL "")
+  FetchContent_Declare(
+    Protobuf
+    GIT_REPOSITORY ${_protobuf_repository}
+    GIT_TAG ${_protobuf_tag}
+    GIT_SUBMODULES "")
+endif()
+
+find_package(pybind11 ${_pybind11_version} EXACT QUIET)
+if(NOT pybind11_FOUND)
+  set(PYBIND11_TEST OFF)
+  FetchContent_Declare(
+    pybind11
+    GIT_REPOSITORY ${_pybind11_repository}
+    GIT_TAG ${_pybind11_tag})
+endif()
+
+# ============================================================================
+# Make dependencies avaialble
+
+if(NOT absl_FOUND)
+  message(CHECK_START "Fetching Abseil-cpp")
+  list(APPEND CMAKE_MESSAGE_INDENT "  ")
+  FetchContent_MakeAvailable(absl)
+  list(POP_BACK CMAKE_MESSAGE_INDENT)
+  message(CHECK_PASS "fetched")
+endif()
+
+if(NOT Protobuf_FOUND)
+  message(CHECK_START "Fetching Protobuf")
+  list(APPEND CMAKE_MESSAGE_INDENT "  ")
+  FetchContent_MakeAvailable(Protobuf)
+  list(POP_BACK CMAKE_MESSAGE_INDENT)
+  message(CHECK_PASS "fetched")
+endif()
+
+if(NOT pybind11_FOUND)
+  message(CHECK_START "Fetching pybind11")
+  list(APPEND CMAKE_MESSAGE_INDENT "  ")
+  FetchContent_MakeAvailable(pybind11)
+  list(POP_BACK CMAKE_MESSAGE_INDENT)
+  message(CHECK_PASS "fetched")
+endif()