cannot import name frontend

[huyn]

When I was compiling th++ after installing folly and fbthrift, I encountered an error

[  5%] Generating thpp/if/gen-cpp2/Tensor_data.h, thpp/if/gen-cpp2/Tensor_types.h, thpp/if/gen-cpp2/Tensor_types.tcc, thpp/if/gen-cpp2/Tensor_constants.h, thpp/if/gen-cpp2/Tensor_data.cpp, thpp/if/gen-cpp2/Tensor_types.cpp, thpp/if/gen-cpp2/Tensor_constants.cpp
/usr/bin/python: cannot import name frontend
CMakeFiles/thpp.dir/build.make:61: recipe for target 'thpp/if/gen-cpp2/Tensor_data.h' failed
make[2]: *** [thpp/if/gen-cpp2/Tensor_data.h] Error 1
CMakeFiles/Makefile2:67: recipe for target 'CMakeFiles/thpp.dir/all' failed
make[1]: *** [CMakeFiles/thpp.dir/all] Error 2
Makefile:138: recipe for target 'all' failed
make: *** [all] Error 2

I checked frontend.so under fbthrift, but I could find it.
My question is How should I do to generate frontend.so?
Many thanks in advance.

[TaoTaoFu]

hi， do you solve it ？ I meet the same problem ：（

[huyn]

@TaoTaoFu not yet.
branch v1.0 on ubuntu 14.04 seems work.

[TaoTaoFu]

thanks, I will try it. @huyn

[lwjyqjykn]

i also came up this problem, how do you slove it@TaoTaoFu

[fengyang0317]

We can manually compile the frontend.so file. The following is the command I used.

g++ -I /usr/include/python2.7 -I /home/yfeng23/utils/fbthrift -std=c++14 -fpic -shared -o frontend.so compiler.cc -lboost_python -lpython2.7 -L/build/lib -lcompiler_base -lcompiler_ast -lboost_system -lboost_filesystem -lssl -lcrypto

[ZYX-MLer]

@fengyang0317 I compile frontend.so as your advise and get frontend.so in /fbthrift/thrift/compiler/py/frontend.so but i still get the error:
/usr/bin/python: cannot import name frontend

when i copy frontend.so to python2.7/dist-packages I can import frontend in python but still get that error when run ./build.sh

how do you slove it?

[siahewei]

i have faced same problem on ubuntu16.04, and i solve it from related information. frontend.so can copile by script "g++ -I /usr/include/python2.7 -I ./fbthrift -std=c++14 -fpic -shared -o frontend.so compiler.cc -lboost_python -lpython2.7 -L/build/lib -lcompiler_base -lcompiler_ast -lboost_system -lboost_filesystem -lssl -lcrypto" . then faced another problem "relocation R_X86_64_32 against", fix CMakefile.txt add "set(CMAKE_CXX_FLAGS "-fPIC")
set(CMAKE_C_FLAGS "-fPIC")", will be successed. good luck for you.

[Jayhello]

I just want to say FUCK! waste me lots of time

[Jayhello]

as @siahewei method I solve this, remember to make install After reinstall.

[SunnyCat2013]

As I said in facebookarchive/thpp#51 (comment) , you should copy frontend to somewhere under directory thrift_compiler.

[raffra]

@siahewei
Hi! I'm trying to replicate your fix recompiling fbthrift with CMAKE_CXX_FLAGS and CMAKE_C_FLAGS set to -fPIC but without success. Can you describe better your procedure?

This is what I'm doing:
-- I've added the two "set command" in the libs_only section of the fbthrift CMakeList.txt

    set(CMAKE_CXX_FLAGS "-fPIC")
    set(CMAKE_C_FLAGS "-fPIC")

-- I'm enabling libs_only flag with cmake-gui for fbthrift
-- I created another package with checkinstall called fbthrift_libs
-- I installed it with sudo dpkg --install --force-all
-- I'm running the command

   g++ -I /usr/include/python2.7 -I /home/francesco/openface/fbthrift -std=c++14 -fpic -shared -o frontend.so compiler.cc -lboost_python -lpython2.7 -L/build/lib -lcompiler_base -lcompiler_ast -lboost_system -lboost_filesystem -lssl -lcrypto

in this path
/home/francesco/openface/fbthrift/thrift/compiler/py

I remember that I've seen the "compile only" in another package, maybe thift itself, do you think I've to recompile it again even adding these flags?

[k22jung]

@raffra which CMakefile.txt did you edit? Make sure it's the Makefile in /fbthrift/thrift/compiler, because there are multiple CMakefiles and after placing the flags in that file it worked.

[engahmed1190]

i have run this command under /fbthrift/thrift/compiler/py
g++ -I /usr/include/python2.7 -I /tmp/fblualib-build.FSDy82/fbthrift -std=c++14 -fpic -shared -o frontend.so compiler.cc -lboost_python -lpython2.7 -L/build/lib -lcompiler_base -lcompiler_ast -lboost_system -lboost_filesystem -lssl -lcrypto

and added at the beginning of CMakefile.txt

# Set the compiler directory
set(COMPILER_DIR ${CMAKE_CURRENT_SOURCE_DIR})

# Override default install path for `make install` step
set(CMAKE_INSTALL_PREFIX ${THRIFT_HOME})
set(CMAKE_CXX_FLAGS "-fPIC")
set(CMAKE_C_FLAGS "-fPIC")
# Compile Flex and Bison files and tie their dependencies 

still the same error

`

/usr/bin/ld: //usr/local/lib/libcompiler_base.a(common.cc.o): relocation R_X86_64_32 against `.rodata' can not be used when making a shared object; recompile with -fPIC

`

[gbolin]

@engahmed1190 , I solved your problem, here is my operation.
1.modify CMakefile.txt
2.rebuild/reinstall fbthrift(must step)
3.run you command under /fbthrift/thrift/compiler/py

g++ -I /usr/include/python2.7 -I /tmp/fblualib-build.FSDy82/fbthrift -std=c++14 -fpic -shared -o frontend.so compiler.cc -lboost_python -lpython2.7 -L/build/lib -lcompiler_base -lcompiler_ast -lboost_system -lboost_filesystem -lssl -lcrypto

after this, you get your frontend.so successfully.

[ilovin]

thx @githubgs

1. modify which CMakeList? under the 'fbthrift'
   add two line

set(CMAKE_CXX_FLAGS "-fPIC")
set(CMAKE_C_FLAGS "-fPIC")

2. rebuild/reinstall
3. for python3

g++ -I /usr/include/python3.5 -I /tmp/fblualib-build.***/fbthrift -std=c++14 -fpic -shared -o frontend.so compiler.cc -lboost_python-py35 -lpython3.5m -L/build/lib -lcompiler_base -lcompiler_ast -lboost_system -lboost_filesystem -lssl -lcrypto

ldconfig -p to find the python version

[adam-dziedzic]

what @siahewei wrote was very helpful!

I also compiled the python files afterwards, so the whole thing is:

dir=`pwd`
git clone https://github.com/facebook/fbthrift
cd fbthrift
# echo "set(CMAKE_CXX_FLAGS "-fPIC")" >> CMakeLists.txt 
# echo "set(CMAKE_C_FLAGS "-fPIC")" >> CMakeLists.txt
# https://stackoverflow.com/questions/9533679/how-to-insert-a-text-at-the-beginning-of-a-file
# https://github.com/facebook/fbthrift/issues/249
sed -i '6s/^/set(CMAKE_CXX_FLAGS "-fPIC")\n/' CMakeLists.txt
sed -i '7s/^/set(CMAKE_C_FLAGS "-fPIC")\n/' CMakeLists.txt

cd build
cmake .. # Add -DOPENSSL_ROOT_DIR for macOS. Usually in /usr/local/ssl
# make # or make -j $(nproc), or make install.
make -j $(nproc)
sudo make install
sudo ldconfig
cd ${dir}

# more problems with thrift
# in ~/fbthrift/thrift/compiler/py$
init_dir=`pwd`
cd fbthrift/thrift/compiler/py
sudo g++ -I /usr/include/python2.7 -I /home/${USER}/fbthrift -std=c++14 -fpic -shared -o frontend.so compiler.cc -lboost_python -lpython2.7 -L/build/lib -lcompiler_base -lcompiler_ast -lboost_system -lboost_filesystem -lssl -lcrypto
cd ${init_dir}

init_dir=`pwd`
# it has to be python 2.7
mkdir tmp
cp -a fbthrift/thrift/compiler/py tmp/
cd tmp/py
sudo python setup.py install
cd ${init_dir}
 

[sani1486]

sudo g++ -I /usr/include/python2.7 -I /home/sani/fbthrift/ -std=c++14 -fPIC -shared -o frontend.so compiler.cc -lboost_python -lpython2.7 -L/build/lib -Wl,--start-group -lcompiler_base -lcompiler_base -lcompiler_ast -lboost_system -lboost_filesystem -lssl -lcrypto -Wl,--end-group

I cant figure out what am i doing wrong here .. Please help me someone .

[avalonalex]

Python front end is no loner needed