# protobuf\_generate\_cpp not found

**URL:** <https://discourse.cmake.org/t/protobuf-generate-cpp-not-found/7053>\
**Category:** Code\
**Created:** [December 12, 2022, 1:39pm UTC](https://discourse.cmake.org/t/protobuf-generate-cpp-not-found/7053 "2022-12-12T13:39:06Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![eriols](https://discourse.cmake.org/user_avatar/discourse.cmake.org/eriols/32/945_2.png) [@eriols](https://discourse.cmake.org/u/eriols)\
**Post date:** [December 12, 2022, 1:39pm UTC](https://discourse.cmake.org/t/protobuf-generate-cpp-not-found/7053/1 "2022-12-12T13:39:06Z")

</div>

I don’t see a whole lot in the docs about the preqequisites of the above function (?). Using it on 3.24.2 I have no problem but on some build agents I’m using which are on 3.16 it fails with `Unknown CMake command "protobuf_generate_cpp".` Can anyone tell me what the requirements for this really are please - or perhaps even better update the docs to clarify under which conditions it won’t be found?

On SO I also found [this](https://stackoverflow.com/questions/52533396/cmake-cant-find-protobuf-protobuf-generate-cpp) old post which perhaps could use some authoritative advice. The hackish answers there did not really help me.

Edit: I guess this is because of the different modes of find\_package but I think it could be better documented that this appears to be only available if using the cmake provided find module.

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<div class="post-metadata">

**Author:** ![hwhsu1231](https://discourse.cmake.org/user_avatar/discourse.cmake.org/hwhsu1231/32/5358_2.png) [@hwhsu1231](https://discourse.cmake.org/u/hwhsu1231)\
**Post date:** [December 14, 2022, 4:13am UTC](https://discourse.cmake.org/t/protobuf-generate-cpp-not-found/7053/2 "2022-12-14T04:13:25Z")

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@eriols - I think I know the the problem you encountered. This problem is related to:

- [Using find\_package(Protobuf) with 3.0.0 · Issue #1931 · protocolbuffers/protobuf (github.com)](https://github.com/protocolbuffers/protobuf/issues/1931)

In short, **“`protobuf_generated_cpp()` is a legacy command”**. Instead, you should use **“`protobuf_generate()` command for the modern usage”**.

There will be a cache variable defined when calling `find_package(Protobuf)` with Config Mode, `protobuf_MODULE_COMPATIBLE`.

- You can use `protobuf_generate_cpp()` if it is set to `ON`.
- You cannot do so if it is set to `OFF` or EMPTY.

The following code is my template `CMakeLists.txt` using Protobuf, which works successfully. You can take a look for reference.

```cmake
get_filename_component(target_name "${CMAKE_CURRENT_SOURCE_DIR}" NAME)
message("==== TARGET: ${target_name}")
add_executable("${target_name}")

file(GLOB src_files "*.cpp")
file(GLOB hdr_files "*.hpp" "*.h")
file(GLOB proto_files "*.proto")

set(CMAKE_INCLUDE_CURRENT_DIR ON)
if(protobuf_MODULE_COMPATIBLE)
    # Legacy Support
    protobuf_generate_cpp(proto_srcs proto_hdrs "${proto_files}")
    list(APPEND src_files "${proto_srcs}")
    list(APPEND hdr_files "${proto_hdrs}")
endif()

target_sources("${target_name}"
    PRIVATE 
        "${src_files}"
        "${hdr_files}"
        "${proto_files}")

target_link_libraries("${target_name}"
    PRIVATE
        protobuf::libprotobuf
        protobuf::libprotoc)

if(NOT protobuf_MODULE_COMPATIBLE)
    # Modern Usage
    protobuf_generate(TARGET "${target_name}")
endif()

```