CTranslate library example code compile fail

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1

I’m not a C++ programmer by any stretch, but I wanted to try my hand at the sample code provided in the README.md for CTranslate. So I fired up a docker ubuntu:16.04 container, installed git, g++, libboost-all-dev, and libeigen3-dev. Then I cloned CTranslate and ran git submodule update --init.

Finally, I set the CPLUS_INCLUDE_PATH env var to:
/CTranslate/include:/CTranslate/include/onmt:/CTranslate/lib/TH:/CTranslate/lib/tokenizer/include:/usr/include/eigen3

Now, attempting to compile test.c (copy-pasted from the README) failed spectacularly:

/tmp/ccXYswIf.o: In function 'onmt::ids_to_words(onmt::Dictionary const&, std::vector<unsigned long, std::allocator<unsigned long> > const&)': test.c:(.text+0xaf): undefined reference to 'onmt::Dictionary::get_id_word[abi:cxx11](unsigned long) const' /tmp/ccXYswIf.o: In function 'onmt::ids_to_words_replace(onmt::Dictionary const&, onmt::PhraseTable const&, std::vector<unsigned long, std::allocator<unsigned long> > const&, 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&, std::vector<std::vector<float, std::allocator<float> >, std::allocator<std::vector<float, std::allocator<float> > > > const&)': test.c:(.text+0x1c7): undefined reference to 'onmt::Dictionary::unk_id' test.c:(.text+0x1fc): undefined reference to 'onmt::Dictionary::get_id_word[abi:cxx11](unsigned long) const' test.c:(.text+0x2cf): undefined reference to 'onmt::PhraseTable::is_empty() const' test.c:(.text+0x2f0): undefined reference to 'onmt::PhraseTable::lookup(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&) const' /tmp/ccXYswIf.o: In function 'onmt::words_to_ids(onmt::Dictionary const&, 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&)': test.c:(.text+0x463): undefined reference to 'onmt::Dictionary::get_word_id(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&) const' /tmp/ccXYswIf.o: In function 'main': test.c:(.text+0x7bb): undefined reference to 'onmt::TranslatorFactory::build(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&, bool, unsigned long, unsigned long)' collect2: error: ld returned 1 exit status

What am I missing?

2

How did you compile it exactly?

The easiest is to move test.c to CTranslate/cli/test.cc and add:

add_executable(testing
  test.cc
  )
target_link_libraries(testing
  ${PROJECT_NAME}
  )

to CTranslate/cli/CMakeLists.txt and then simply follow the compilation steps from the README.

3

Thanks for the quick reply, @guillaumekln! I used:
g++ -std=c++11 -o foo test.c

I’ll check the Boost_INCLUDE_DIRS and Boost_LIBRARIES to make sure I didn’t miss anything there. I’d like to try compiling without make/cmake initially as I try to learn how the pieces fit together, unless that’s the only way to get it to compile.

4

You need CMake to at least compile CTranslate itself, without it is unnecessarily complicated.

If you want to manually compile your binary after that:

g++ -O3 -std=c++11 test.c -o foo -I/CTranslate/include -I/CTranslate/lib/TH -I/CTranslate/lib/tokenizer/include -I/usr/include/eigen3 -L/CTranslate/build -lonmt
LD_PRELOAD=/CTranslate/build/libonmt.so ./test
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