如何将编译好的 Protobuf 导出到静态库 C++

Question

我想制作一个包含 .cc 和 .h 文件的静态库，这些文件是从 protoc 编译器生成的，以便从其他项目链接到它，我正在使用 C++

Answer 1

Instead of using protoc manually you can let CMake compile the proto files. To do so you will have CMakeLists.txt in the same folder as you proto files (I use a separate folder called proto here). and this CMakeLists.txt will look like:

# Proto files
set(proto
    test.proto
    # maybe others
)

# Generated sources
set(proto_srcs
    ${CMAKE_BINARY_DIR}/proto/test.pb.cc
    # maybe others
)

# Generated headers
set(proto_hdrs
    ${CMAKE_BINARY_DIR}/proto/test.pb.h
    # maybe others
)

add_custom_command(
    OUTPUT ${proto_srcs} ${proto_hdrs}
    COMMAND protoc
    ARGS --cpp_out ${CMAKE_BINARY_DIR}/proto
        -I ${CMAKE_SOURCE_DIR}/proto
        ${proto} 
    DEPENDS ${proto}
)

add_library(protos
    ${proto_srcs}
    ${proto_hdrs}
)
target_link_libraries(protos
    libprotobuf
)

So as you can see you need to specify the proto files that you want to compile (first set ). Then you need the specify the name of the generated cc and h file (second and third set ). And then we use the custom command to generate automatically what you have been doing manually with protoc.

Finally, we create a libprotos.a (static library) file called protos_lib.a with the add_library and link the protobuf dependency with target_link_libraries .

Hope that helps, let me know if you need more details.