Hi @nihui & ncnn users,

I am trying to use NCNN build library files for another project. First, I build NCNN in jetson nano according to the instruction Build for Linux / NVIDIA Jetson / Raspberry Pi. Now I have ncnn library and header files in ncnn/build/install folder. Vulkan was also enabled while building the ncnn.

While using NCNN lib in the separate project there is link error such as:

libncnn.a(gpu.cpp.o): undefined reference to `glslang::FinalizeProcess()'
...

I do not know why library linking is not working simply.

The attached file is the whole example project. I just took scrfd.cpp file in example for showing the bug.

jetson-ncnn-vulkan-app.zip

Build log and error:

jetson-ncnn-vulkan-app/build$ cmake ..
-- The C compiler identification is GNU 7.5.0
-- The CXX compiler identification is GNU 7.5.0
-- Check for working C compiler: /usr/bin/cc
-- Check for working C compiler: /usr/bin/cc -- works
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Detecting C compile features
-- Detecting C compile features - done
-- Check for working CXX compiler: /usr/bin/c++
-- Check for working CXX compiler: /usr/bin/c++ -- works
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- Found OpenCV: /usr (found version "4.1.1")
-- Found Vulkan: /usr/lib/aarch64-linux-gnu/libvulkan.so
-- Found OpenMP_C: -fopenmp (found version "4.5")
-- Found OpenMP_CXX: -fopenmp (found version "4.5")
-- Found OpenMP: TRUE (found version "4.5")
OPENMP FOUND
-- Configuring done
-- Generating done
-- Build files have been written to: /home/ghimire/Desktop/jetson-ncnn-vulkan-app/build
ghimire@jetsonnano:~/Desktop/jetson-ncnn-vulkan-app/build$ makeScanning dependencies of target NCNN_VULKAN_TEST
[ 50%] Building CXX object CMakeFiles/NCNN_VULKAN_TEST.dir/src/scrfd_ncnn.cpp.o
[100%] Linking CXX executable NCNN_VULKAN_TEST
../ncnn/lib/libncnn.a(gpu.cpp.o): In function `ncnn::destroy_gpu_instance()':
gpu.cpp:(.text+0xca0): undefined reference to `glslang::FinalizeProcess()'
../ncnn/lib/libncnn.a(gpu.cpp.o): In function `ncnn::create_gpu_instance()':
gpu.cpp:(.text+0x3e40): undefined reference to `glslang::InitializeProcess()'
../ncnn/lib/libncnn.a(gpu.cpp.o): In function `ncnn::compile_spirv_module(char const*, int, ncnn::Option const&, std::vector<unsigned int, std::allocator<unsigned int> >&)':
gpu.cpp:(.text+0x77e8): undefined reference to `glslang::TShader::TShader(EShLanguage)'
gpu.cpp:(.text+0x77fc): undefined reference to `glslang::TShader::setStringsWithLengths(char const* const*, int const*, int)'
gpu.cpp:(.text+0x7810): undefined reference to `glslang::TShader::addProcesses(std::vector<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::allocator<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > > > const&)'
gpu.cpp:(.text+0x7820): undefined reference to `glslang::TShader::setEntryPoint(char const*)'
gpu.cpp:(.text+0x782c): undefined reference to `glslang::TShader::setSourceEntryPoint(char const*)'
gpu.cpp:(.text+0x79c0): undefined reference to `glslang::TShader::parse(TBuiltInResource const*, int, EProfile, bool, bool, EShMessages, glslang::TShader::Includer&)'
gpu.cpp:(.text+0x7a08): undefined reference to `glslang::TShader::getInfoLog()'
gpu.cpp:(.text+0x7a30): undefined reference to `glslang::TShader::getInfoDebugLog()'
gpu.cpp:(.text+0x7a54): undefined reference to `glslang::TShader::~TShader()'
gpu.cpp:(.text+0x8404): undefined reference to `glslang::GlslangToSpv(glslang::TIntermediate const&, std::vector<unsigned int, std::allocator<unsigned int> >&, glslang::SpvOptions*)'
gpu.cpp:(.text+0x8410): undefined reference to `glslang::TShader::~TShader()'
gpu.cpp:(.text+0x9334): undefined reference to `glslang::TShader::~TShader()'
collect2: error: ld returned 1 exit status
CMakeFiles/NCNN_VULKAN_TEST.dir/build.make:117: recipe for target 'NCNN_VULKAN_TEST' failed
make[2]: *** [NCNN_VULKAN_TEST] Error 1
CMakeFiles/Makefile2:67: recipe for target 'CMakeFiles/NCNN_VULKAN_TEST.dir/all' failed
make[1]: *** [CMakeFiles/NCNN_VULKAN_TEST.dir/all] Error 2
Makefile:83: recipe for target 'all' failed
make: *** [all] Error 2

I will really appreciate help with this issue.
Waiting to hear from you.

Thanks.

Best,
Deepak