Link Error With Torch Library

[mf523]

Describe the bug I am trying to bind a simple example software with drogon as interface, and torch is involved as core ML function.

To Reproduce Steps to reproduce the behavior:

1. create a default drogon controller
2. add torch library in CMakeList.txt file
3. cmake --build
4. See error like below

/usr/bin/c++   -D_GLIBCXX_USE_CXX11_ABI=0 CMakeFiles/CppModelServ.dir/main.cc.o CMakeFiles/CppModelServ.dir/controllers/MmsCtrl.cc.o -o CppModelServ  -Wl,-rpath,/usr/local/libtorch/lib:/usr/local/cuda/lib64/stubs:/usr/local/cuda/lib64 /usr/local/lib/libdrogon.a /usr/local/libtorch/lib/libtorch.so /usr/local/libtorch/lib/libc10.so /usr/local/libtorch/lib/libkineto.a /usr/local/cuda/lib64/stubs/libcuda.so /usr/local/cuda/lib64/libnvrtc.so /usr/local/cuda/lib64/libnvToolsExt.so /usr/local/cuda/lib64/libcudart.so /usr/local/libtorch/lib/libc10_cuda.so /usr/local/lib/libtrantor.a -ldl -lstdc++fs /usr/lib/x86_64-linux-gnu/libjsoncpp.so /usr/lib/x86_64-linux-gnu/libuuid.so /usr/lib/x86_64-linux-gnu/libz.so /usr/lib/x86_64-linux-gnu/libssl.so /usr/lib/x86_64-linux-gnu/libcrypto.so -lpthread -Wl,--no-as-needed,"/usr/local/libtorch/lib/libtorch_cpu.so" -Wl,--as-needed -Wl,--no-as-needed,"/usr/local/libtorch/lib/libtorch_cuda.so" -Wl,--as-needed /usr/local/libtorch/lib/libc10_cuda.so /usr/local/libtorch/lib/libc10.so /usr/local/cuda/lib64/libcufft.so /usr/local/cuda/lib64/libcurand.so /usr/local/cuda/lib64/libcublas.so /usr/lib/x86_64-linux-gnu/libcudnn.so -Wl,--no-as-needed,"/usr/local/libtorch/lib/libtorch.so" -Wl,--as-needed /usr/local/cuda/lib64/libnvToolsExt.so /usr/local/cuda/lib64/libcudart.so 
/usr/bin/ld: CMakeFiles/CppModelServ.dir/main.cc.o: in function `std::enable_if<std::is_default_constructible<drogon::plugin::AccessLogger>::value, void>::type drogon::DrObject<drogon::plugin::AccessLogger>::DrAllocator::registerClass<drogon::plugin::AccessLogger>()':
main.cc:(.text._ZN6drogon8DrObjectINS_6plugin12AccessLoggerEE11DrAllocator13registerClassIS2_EENSt9enable_ifIXsrSt24is_default_constructibleIT_E5valueEvE4typeEv[_ZN6drogon8DrObjectINS_6plugin12AccessLoggerEE11DrAllocator13registerClassIS2_EENSt9enable_ifIXsrSt24is_default_constructibleIT_E5valueEvE4typeEv]+0x46): undefined reference to `drogon::DrClassMap::registerClass(std::string const&, std::function<drogon::DrObjectBase* ()> const&)'
/usr/bin/ld: CMakeFiles/CppModelServ.dir/main.cc.o: in function `std::enable_if<std::is_default_constructible<drogon::plugin::SecureSSLRedirector>::value, void>::type drogon::DrObject<drogon::plugin::SecureSSLRedirector>::DrAllocator::registerClass<drogon::plugin::SecureSSLRedirector>()':
main.cc:(.text._ZN6drogon8DrObjectINS_6plugin19SecureSSLRedirectorEE11DrAllocator13registerClassIS2_EENSt9enable_ifIXsrSt24is_default_constructibleIT_E5valueEvE4typeEv[_ZN6drogon8DrObjectINS_6plugin19SecureSSLRedirectorEE11DrAllocator13registerClassIS2_EENSt9enable_ifIXsrSt24is_default_constructibleIT_E5valueEvE4typeEv]+0x46): undefined reference to `drogon::DrClassMap::registerClass(std::string const&, std::function<drogon::DrObjectBase* ()> const&)'
/usr/bin/ld: CMakeFiles/CppModelServ.dir/main.cc.o: in function `std::enable_if<std::is_default_constructible<drogon::NotFound>::value, void>::type drogon::DrObject<drogon::NotFound>::DrAllocator::registerClass<drogon::NotFound>()':
main.cc:(.text._ZN6drogon8DrObjectINS_8NotFoundEE11DrAllocator13registerClassIS1_EENSt9enable_ifIXsrSt24is_default_constructibleIT_E5valueEvE4typeEv[_ZN6drogon8DrObjectINS_8NotFoundEE11DrAllocator13registerClassIS1_EENSt9enable_ifIXsrSt24is_default_constructibleIT_E5valueEvE4typeEv]+0x46): undefined reference to `drogon::DrClassMap::registerClass(std::string const&, std::function<drogon::DrObjectBase* ()> const&)'
/usr/bin/ld: CMakeFiles/CppModelServ.dir/main.cc.o: in function `std::enable_if<std::is_default_constructible<drogon::LocalHostFilter>::value, void>::type drogon::DrObject<drogon::LocalHostFilter>::DrAllocator::registerClass<drogon::LocalHostFilter>()':
main.cc:(.text._ZN6drogon8DrObjectINS_15LocalHostFilterEE11DrAllocator13registerClassIS1_EENSt9enable_ifIXsrSt24is_default_constructibleIT_E5valueEvE4typeEv[_ZN6drogon8DrObjectINS_15LocalHostFilterEE11DrAllocator13registerClassIS1_EENSt9enable_ifIXsrSt24is_default_constructibleIT_E5valueEvE4typeEv]+0x46): undefined reference to `drogon::DrClassMap::registerClass(std::string const&, std::function<drogon::DrObjectBase* ()> const&)'
/usr/bin/ld: CMakeFiles/CppModelServ.dir/main.cc.o: in function `std::enable_if<std::is_default_constructible<drogon::IntranetIpFilter>::value, void>::type drogon::DrObject<drogon::IntranetIpFilter>::DrAllocator::registerClass<drogon::IntranetIpFilter>()':
main.cc:(.text._ZN6drogon8DrObjectINS_16IntranetIpFilterEE11DrAllocator13registerClassIS1_EENSt9enable_ifIXsrSt24is_default_constructibleIT_E5valueEvE4typeEv[_ZN6drogon8DrObjectINS_16IntranetIpFilterEE11DrAllocator13registerClassIS1_EENSt9enable_ifIXsrSt24is_default_constructibleIT_E5valueEvE4typeEv]+0x46): undefined reference to `drogon::DrClassMap::registerClass(std::string const&, std::function<drogon::DrObjectBase* ()> const&)'
/usr/bin/ld: CMakeFiles/CppModelServ.dir/controllers/MmsCtrl.cc.o: in function `MmsCtrl::get(std::shared_ptr<drogon::HttpRequest> const&, std::function<void (std::shared_ptr<drogon::HttpResponse> const&)>&&, std::string) const':
MmsCtrl.cc:(.text+0x12a): undefined reference to `Json::Value::Value(std::string const&)'
/usr/bin/ld: MmsCtrl.cc:(.text+0x1ba): undefined reference to `Json::Value::Value(std::string const&)'
/usr/bin/ld: CMakeFiles/CppModelServ.dir/controllers/MmsCtrl.cc.o: in function `MmsCtrl::list(std::shared_ptr<drogon::HttpRequest> const&, std::function<void (std::shared_ptr<drogon::HttpResponse> const&)>&&) const':
MmsCtrl.cc:(.text+0x494): undefined reference to `Json::Value::Value(std::string const&)'
/usr/bin/ld: MmsCtrl.cc:(.text+0x55c): undefined reference to `Json::Value::Value(std::string const&)'
/usr/bin/ld: CMakeFiles/CppModelServ.dir/controllers/MmsCtrl.cc.o: in function `MmsCtrl::invoke(std::shared_ptr<drogon::HttpRequest> const&, std::function<void (std::shared_ptr<drogon::HttpResponse> const&)>&&, std::string) const':
MmsCtrl.cc:(.text+0xdc8): undefined reference to `drogon::utils::getUuid()'
/usr/bin/ld: MmsCtrl.cc:(.text+0xde1): undefined reference to `Json::Value::Value(std::string const&)'
/usr/bin/ld: CMakeFiles/CppModelServ.dir/controllers/MmsCtrl.cc.o: in function `std::enable_if<std::is_default_constructible<MmsCtrl>::value, void>::type drogon::DrObject<MmsCtrl>::DrAllocator::registerClass<MmsCtrl>()':
MmsCtrl.cc:(.text._ZN6drogon8DrObjectI7MmsCtrlE11DrAllocator13registerClassIS1_EENSt9enable_ifIXsrSt24is_default_constructibleIT_E5valueEvE4typeEv[_ZN6drogon8DrObjectI7MmsCtrlE11DrAllocator13registerClassIS1_EENSt9enable_ifIXsrSt24is_default_constructibleIT_E5valueEvE4typeEv]+0x46): undefined reference to `drogon::DrClassMap::registerClass(std::string const&, std::function<drogon::DrObjectBase* ()> const&)'
/usr/bin/ld: CMakeFiles/CppModelServ.dir/controllers/MmsCtrl.cc.o: in function `std::shared_ptr<MmsCtrl> drogon::DrClassMap::getSingleInstance<MmsCtrl>()':
MmsCtrl.cc:(.text._ZN6drogon10DrClassMap17getSingleInstanceI7MmsCtrlEESt10shared_ptrIT_Ev[_ZN6drogon10DrClassMap17getSingleInstanceI7MmsCtrlEESt10shared_ptrIT_Ev]+0x56): undefined reference to `drogon::DrClassMap::getSingleInstance(std::string const&)'
collect2: error: ld returned 1 exit status
make[2]: *** [CMakeFiles/CppModelServ.dir/build.make:136: CppModelServ] Error 1
make[2]: Leaving directory '/mnt/cpp-model-serv.git'
make[1]: *** [CMakeFiles/Makefile2:100: CMakeFiles/CppModelServ.dir/all] Error 2
make[1]: Leaving directory '/mnt/cpp-model-serv.git'
make: *** [Makefile:91: all] Error 2

Expected behavior build pass

Screenshots If applicable, add screenshots to help explain your problem.

Additional context Add any other context about the problem here.

[mf523]

CMakeFile.txt

project(CppModelServ CXX)
project(CppModelServ VERSION 1.0)

configure_file(CppModelServConfig.h.in CppModelServConfig.h)

include(CheckIncludeFileCXX)

check_include_file_cxx(any HAS_ANY)
check_include_file_cxx(string_view HAS_STRING_VIEW)
check_include_file_cxx(coroutine HAS_COROUTINE)

# specify the C++ standard
if (HAS_ANY AND HAS_STRING_VIEW AND HAS_COROUTINE)
    set(CMAKE_CXX_STANDARD 20)
elseif (HAS_ANY AND HAS_STRING_VIEW)
    set(CMAKE_CXX_STANDARD 17)
else ()
    set(CMAKE_CXX_STANDARD 14)
endif ()

set(CMAKE_CXX_STANDARD_REQUIRED ON)
set(CMAKE_CXX_EXTENSIONS OFF)


add_executable(${PROJECT_NAME} main.cc)


# ##############################################################################
# If you include the drogon source code locally in your project, use this method
# to add drogon 
# add_subdirectory(drogon) 
# target_link_libraries(${PROJECT_NAME} PRIVATE drogon)
#
# and comment out the following lines
find_package(Drogon CONFIG REQUIRED)


# ##############################################################################


find_package(Torch REQUIRED)

set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${DROGON_CXX_FLAGS} ${TORCH_CXX_FLAGS}")
target_link_libraries(${PROJECT_NAME} "${DROGON_LIBRARIES}" "${TORCH_LIBRARIES}")


if (CMAKE_CXX_STANDARD LESS 17)
    # With C++14, use boost to support any, string_view and filesystem
    message(STATUS "use c++14")
    find_package(Boost 1.61.0 REQUIRED)
    target_link_libraries(${PROJECT_NAME} PUBLIC Boost::boost)
elseif (CMAKE_CXX_STANDARD LESS 20)
    message(STATUS "use c++17")
else ()
    message(STATUS "use c++20")
endif ()

aux_source_directory(controllers CTL_SRC)
aux_source_directory(filters FILTER_SRC)
aux_source_directory(plugins PLUGIN_SRC)
aux_source_directory(models MODEL_SRC)

drogon_create_views(${PROJECT_NAME} ${CMAKE_CURRENT_SOURCE_DIR}/views
                    ${CMAKE_CURRENT_BINARY_DIR})
# use the following line to create views with namespaces.
# drogon_create_views(${PROJECT_NAME} ${CMAKE_CURRENT_SOURCE_DIR}/views
#                     ${CMAKE_CURRENT_BINARY_DIR} TRUE)

target_include_directories(${PROJECT_NAME}
                           PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}
                                   ${CMAKE_CURRENT_SOURCE_DIR}/models)
target_sources(${PROJECT_NAME}
               PRIVATE
               ${SRC_DIR}
               ${CTL_SRC}
               ${FILTER_SRC}
               ${PLUGIN_SRC}
               ${MODEL_SRC})
# ##############################################################################
# uncomment the following line for dynamically loading views 
# set_property(TARGET ${PROJECT_NAME} PROPERTY ENABLE_EXPORTS ON)

# ##############################################################################

add_subdirectory(test)

[marty1885]

@mf523 Thanks for the issue. I'm not familiar with PyTorch w/ C++. May you share a minimal reproducible example? (An example repository that reproduces the issue).

[mf523]

@marty1885 , thanks for quick reply. please follow this https://pytorch.org/cppdocs/installing.html it's good enough for a simple pytorch startup, then the rest are all about how to put drogon and torch together, really simple, no ML knowledge requried.

[marty1885]

I did (hopefully) the exact same setup and it compiled normally. The only thing I've to change being instead of

target_link_libraries(${PROJECT_NAME} "${DROGON_LIBRARIES}" "${TORCH_LIBRARIES}")

I wrote:

target_link_libraries(${PROJECT_NAME} PRIVATE "${DROGON_LIBRARIES}" "${TORCH_LIBRARIES}")

But this is a CMake issue. It has nothing to do with the linker.

[marty1885]

If you can, please share you code that is known to fail. Otherwise I'm not sure if it's my environment making it pass or my code.

[mf523]

#pragma once
#include "CppModelServConfig.h"

#include <drogon/HttpController.h>


using namespace drogon;

struct Model{
    std::string modelName;
    std::string modelUrl;
};


class MmsCtrl:public drogon::HttpController<MmsCtrl>
{
  public:
    METHOD_LIST_BEGIN
    //use METHOD_ADD to add your custom processing function here;
    ADD_METHOD_TO(MmsCtrl::get,"/models/{1:model_name}", Get);//path is /models/{model_name}
    ADD_METHOD_TO(MmsCtrl::list,"/models", Get);//path is /models
    ADD_METHOD_TO(MmsCtrl::load,"/models", Post);//path is /models
    ADD_METHOD_TO(MmsCtrl::unload,"/models/{1:model_name}", Delete);//path is /models/{model_name}
    ADD_METHOD_TO(MmsCtrl::invoke,"/models/{1:model_name}/invoke", Post);//path is /models/{model_name}/invoke
    //ADD_METHOD_TO(models::your_method_name,"/absolute/path/{1}/{2}/list",Get);//path is /absolute/path/{arg1}/{arg2}/list

    METHOD_LIST_END
    // your declaration of processing function maybe like this:
    void get(const HttpRequestPtr &, std::function<void (const HttpResponsePtr &)> &&callback, std::string p1) const;
    void list(const HttpRequestPtr &, std::function<void (const HttpResponsePtr &)> &&callback) const;
    void load(const HttpRequestPtr &, std::function<void (const HttpResponsePtr &)> &&callback, Model &&pNewModel);
    void unload(const HttpRequestPtr &, std::function<void (const HttpResponsePtr &)> &&callback, std::string p1) const;
    void invoke(const HttpRequestPtr &, std::function<void (const HttpResponsePtr &)> &&callback, std::string p1) const;
    // void your_method_name(const HttpRequestPtr& req,std::function<void (const HttpResponsePtr &)> &&callback,double p1,int p2) const;
};

[mf523]

#include "MmsCtrl.h"
#include <torch/torch.h>
#include <ATen/ATen.h>
....

void MmsCtrl::invoke(const HttpRequestPtr &req,
           std::function<void (const HttpResponsePtr &)> &&callback,
           std::string model_name) const
{
    LOG_DEBUG <<"invoke model: " << model_name;
    //Authentication algorithm, read database, verify identity, etc...
    //...
    at::Tensor a = at::ones({2, 2}, at::kInt);
    at::Tensor b = at::randn({2, 2});
    auto c = a + b.to(at::kInt);
    Json::Value ret;
    ret["hello"] = "world";
    ret["uuid"] = drogon::utils::getUuid();
    auto resp=HttpResponse::newHttpJsonResponse(ret);
    callback(resp);
}


// omitted code that has nothing to do with pytorch.

[mf523]

@marty1885 per your request, above is the code I am working one, other than that, everything else is standard drogon framework. the error comes only when I include pytorch lib in cmakefile, when I comment out pytorch in cmakefile and the controller, the error disappear.

[marty1885]

Thanks! I can confirm I've no problem building the sample code with my setup (and executing it).

May you try changing

target_link_libraries(${PROJECT_NAME} "${DROGON_LIBRARIES}" "${TORCH_LIBRARIES}")

into

target_link_libraries(${PROJECT_NAME} PRIVATE "${DROGON_LIBRARIES}" "${TORCH_LIBRARIES}")

And the only other reason I can guess being that I'm not using an official build of LibTorch. I'm using one built by Arch Linux maintainers. So maybe that also have something to do with it.

[mf523]

I tried the PRIVATE key word, doesn't work, my os is ubuntu, can you advice your libtorch version? will try your way.

[mf523]

btw, just out of curiosity, how come libtorch version could cause linker complain undefined reference on drogon side? @marty1885

[marty1885]

I don't know. That's why I asked for a minimal reproducible example as a repository. Maybe I did something that made it work that I don't know I'm doing. The only way to know definitely is to run the exact same code you are using. Here's my version https://github.com/marty1885/drogon-pytorch-poc. Hope if helps.

I'm using PyTorch 1.8.1. To be specific the python-pytorch-opt-cuda-1.8.1-5 Arch Linux Package.

[interfector18]

I don't know how relevant this is to your problem @mf523, but I've recently run into a problem with #include order between Qt 6.1.2 and PyTorch 1.9.0. Placing #include <torch/torch.h> below Qts includes resulted in a weird syntax error from the compiler on correct code. While placing torch first, fixed the issue. I tried with 1.8.1 and 1.7.1, all had the same bug.

Can't hurt to try.

[viig99]

here's a working example which serve imagenet class inference https://github.com/SABER-labs/Drogon-torch-serve.