CMake for Halide Hexagon failed while successfully compiled using g++ - cmake

Question

I am writing CMake file for the following command:
g++ --std=c++11 -DLOG2VLEN=7 -DRUN=1 -DASSEMBLY=1 -DBITCODE=1 -I
/home/user/Qualcomm/HALIDE_Tools/2.2.06/Halide/include -fno-rtti -O3 -g
halide_gaussian_hexagon_generate.cpp /home/user/Qualcomm/HALIDE_Tools/2.2.06/Halide/tools/GenGen.cpp
-L/home/user/Qualcomm/HALIDE_Tools/2.2.06/Halide/lib -lHalide -o
bin/halide_gaussian_hexagon_generate -ldl -lpthread -lz -D_GLIBCXX_USE_CXX11_ABI=0
Above compiling works fine but when I wrote it into CMake I got a bunch of error. I am attaching my CMake file here:
cmake_minimum_required(VERSION 3.10)
project(hexagon_polyblur)
set(CMAKE_CXX_STANDARD 11)
set(HEXAGON_DIR $ENV{HALIDE_ROOT})
set(
HEXAGON_FILES_GAUSSIAN
halide_gaussian_hexagon_generate.cpp
${HEXAGON_DIR}/tools/GenGen.cpp # we must include GenGen to compile the generator
)
set(HEXAGON_GEN_GAUSSIAN ${PROJECT_NAME}_hexagon_generate_gaussian)
add_executable(${HEXAGON_GEN_GAUSSIAN} ${HEXAGON_FILES_GAUSSIAN})
target_include_directories(
${HEXAGON_GEN_GAUSSIAN} PRIVATE
${HEXAGON_DIR}/include
${HEXAGON_DIR}/tools
)
target_link_libraries(${HEXAGON_GEN_GAUSSIAN} ${HEXAGON_DIR}/lib/libHalide.so dl pthread z)
target_compile_options(${HEXAGON_GEN_GAUSSIAN} PUBLIC -fno-rtti)
# target_compile_definitions(${HVX_GEN_GAUSSIAN} PRIVATE LOG2VLEN=7 RUN=1 ASSEMBLY=1 BITCODE=1 _GLIBCXX_USE_CXX11_ABI=0)
In CMake, I am using /usr/bin/g++ and /usr/bin/gcc (g++ (Ubuntu 9.3.0-17ubuntu1~20.04) 9.3.0), which are the same compiler I used for the command line. The ${HEXAGON_DIR} is /home/user/Qualcomm/HALIDE_Tools/2.2.06/Halide. I am not sure why I the CMkae failed here. Part of the error message is shown below:
/usr/bin/ld: CMakeFiles/hexagon_polyblur_hexagon_generate_gaussian.dir /halide_gaussian_hexagon_generate.cpp.o: in function `Halide::Internal::check_introspection(void const*, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, int)':
halide_gaussian_hexagon_generate.cpp:(.text+0xaa): undefined reference to `Halide::Internal::Introspection::get_source_location[abi:cxx11]()'
/usr/bin/ld: halide_gaussian_hexagon_generate.cpp:(.text+0xc7): undefined reference to `Halide::Internal::Introspection::get_variable_name(void const*, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)'
/usr/bin/ld: CMakeFiles/hexagon_polyblur_hexagon_generate_gaussian.dir/halide_gaussian_hexagon_generate.cpp.o: in function `HalideIntrospectionCanary::(anonymous namespace)::TestCompilationUnit::TestCompilationUnit()':
...
Also, when I switch to my original working halide lib that is not for hexagon development, this CMake works. I am not sure whether or not I have a wrong setup in CMake. Any help or suggestion? Thank you!

Answer 1

Have you considered using a more recent version of Halide? Since version 10, we've had good (and constantly improving!) CMake support via find_package.
This should be all you need:
cmake_minimum_required(VERSION 3.16)
project(example)
find_package(Halide REQUIRED)
add_executable(hexagon_gen_gaussian halide_gaussian_hexagon_generate.cpp)
target_link_libraries(hexagon_gen_gaussian PRIVATE Halide::Generator)
Then you can call add_halide_library to run the generator.
Here's a link to our CMake docs for reference: https://github.com/halide/Halide/blob/master/README_cmake.md
You should also look at our example applications (most of them have CMake builds): https://github.com/halide/Halide/tree/master/apps
Feel free to ask any follow-up questions on our GitHub Discussions since I wrote our CMake build/package code.

Answer 2

-L/home/user/Qualcomm/HALIDE_Tools/2.2.06/Halide/lib -lHalide
Translates literally to:
target_link_directories(.... ${THEDIR}/lib)
target_link_libraries(... Halide)
or better:
add_library(halide SHARED IMPORTED)
set_property(TARGET halide PROPERTY
IMPORTED_LOCATION ${THEDIR}/lib/libHalide.so) # or maybe find_library
#
target_link_libraries(... halide) # I wish there would be "target_link_targets"
set(CMAKE_CXX_STANDARD 11)
Better:
set_target_properties(testproject PROPERTIES
CXX_STANDARD 11
CXX_STANDARD_REQUIRED on # maybe also
CXX_EXTENSIONS off
)