背景：

由于项目需要，把所有的proto文件放在了统一的文件夹中，为了方便更新以及加快编译速度，要把这个proto自动转成.cc .pb.h文件，再编译成so。

为此，写了个cmakelist.txt。

主要功能：

1）自动遍历指定目录下所有proto文件，调用ptotoc生成.cc文件，如下图：cc文件存放在上一级目录，目录结构类似。

2）编译成so。

目录结构：

 其中common、geometry等文件夹里面放的都是.proto

上代码CMakeLists.txt：

cmake_minimum_required(VERSION 3.12)
set(CMAKE_FIND_PACKAGE_PREFER_CONFIG ON)
project(dros_proto)

set(dp_MAJOR_VERSION 0)
set(dp_MINOR_VERSION 2)
set(dp_PATCH_VERSION 0)
set(dp_VERSION "${dp_MAJOR_VERSION}.${dp_MINOR_VERSION}.${dp_PATCH_VERSION}")

set(CMAKE_CXX_STANDARD 14)
set(CMAKE_CXX_STANDARD_REQUIRED ON)

set(CMAKE_LIBRARY_OUTPUT_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/../lib)

file(GLOB protobuf_files
  ${CMAKE_CURRENT_SOURCE_DIR}/common/*.proto
  ${CMAKE_CURRENT_SOURCE_DIR}/geometry/*.proto
  ${CMAKE_CURRENT_SOURCE_DIR}/navigation/*.proto
  ${CMAKE_CURRENT_SOURCE_DIR}/sensor/*.proto
  ${CMAKE_CURRENT_SOURCE_DIR}/tutorials/*.proto
)

set(3rd_DIR "${PROJECT_SOURCE_DIR}/../../thirdparty")
set(Protobuf_DIR "${3rd_DIR}/protobuf3.14.0.0")

set(PROTO_META_BASE_DIR ${CMAKE_CURRENT_SOURCE_DIR}/../proto_cpp)
list(APPEND PROTO_FLAGS -I${CMAKE_CURRENT_SOURCE_DIR}/ -I${Protobuf_DIR}/src/)

if(${CMAKE_SYSTEM_PROCESSOR} MATCHES "x86_64")
  set(ARCH_TYPE x64)
elseif(${CMAKE_SYSTEM_PROCESSOR} MATCHES "aarch64")
  set(ARCH_TYPE arm64)
endif()
message("arch type: ${CMAKE_SYSTEM_PROCESSOR}")

set(PROTOC_EXE ${Protobuf_DIR}/bin/${ARCH_TYPE}/protoc-3.14.0.0)
message("proto_exe = ${PROTOC_EXE}")

foreach(FIL ${protobuf_files})
  get_filename_component(FIL_WE ${FIL} NAME_WE)

  string(REGEX REPLACE ".+/(.+)\\..*" "\\1" FILE_NAME ${FIL})
  string(REGEX REPLACE "(.+)\\${FILE_NAME}.*" "\\1" FILE_PATH ${FIL})

  string(REGEX MATCH "(/proto/.*)" MATCH_PATH ${FILE_PATH})
  # message("DDD: ${FILE_PATH}: ${MATCH_PATH}")
  string(REPLACE "/proto/" "/" OUT_PATH ${MATCH_PATH})

  # message("SRC_CPP: ${PROTO_META_BASE_DIR}:${OUT_PATH}:${FIL_WE}.pb.cc")

  set(PROTO_SRCS "${PROTO_SRCS};${PROTO_META_BASE_DIR}${OUT_PATH}${FIL_WE}.pb.cc")
  set(PROTO_HDRS "${PROTO_HDRS};${PROTO_META_BASE_DIR}${OUT_PATH}${FIL_WE}.pb.h")

  EXECUTE_PROCESS(
    COMMAND ${PROTOC_EXE} ${PROTO_FLAGS} --cpp_out=${PROTO_META_BASE_DIR} ${FIL}
  )
endforeach()

include_directories(${Protobuf_DIR}/src)
include_directories(${CMAKE_CURRENT_SOURCE_DIR}/../proto_cpp)

add_library(${PROJECT_NAME} SHARED
  ${PROTO_SRCS}
  ${PROTO_HDRS}
)
set_target_properties(${PROJECT_NAME} PROPERTIES VERSION ${dp_VERSION} SOVERSION ${dp_MAJOR_VERSION})