[CMake] Can't link Openfst library

[vzxxbacq]

I'm developing a gst plugin with kaldi cmake, but I couldn't link openfst when I build project. So I remove CACHE option in get_filename_component in CMakeLists.txt line 185 as follow:

get_filename_component(OpenFST_LIBRARY_DIR ${OpenFST_LIBRARY} DIRECTORY CACHE)
message("OpenFST_LIBRARY: ${OpenFST_LIBRARY}")
message("OpenFST_LIBRARY_DIR: ${OpenFST_LIBRARY_DIR}  (with CACHE option)")
get_filename_component(OpenFST_LIBRARY_DIR ${OpenFST_LIBRARY} DIRECTORY)
message("OpenFST_LIBRARY_DIR: ${OpenFST_LIBRARY_DIR}  (without CACHE option)")

And the output is:

OpenFST_LIBRARY: /home/laptop/code/kaldi/tools/openfst/lib/libfst.so
OpenFST_LIBRARY_DIR:   (with CACHE option)
OpenFST_LIBRARY_DIR: /home/laptop/code/kaldi/tools/openfst/lib (without CACHE option)

I'm not sure this is a bug of kaldi, so I put the linking part in the CMakeLists.txt of custom gst plugin

set(GST_KALDI_DEPS kaldi-online2 kaldi-lat kaldi-decoder kaldi-feat kaldi-transform
        kaldi-gmm kaldi-hmm kaldi-tree kaldi-matrix  kaldi-util kaldi-base kaldi-lm
        kaldi-nnet2 kaldi-nnet3 kaldi-cudamatrix kaldi-ivector kaldi-fstext kaldi-chain)

target_link_libraries(gst-plugin-test
        ${GST_KALDI_DEPS}
        ${GST_LIBRARIES})

[kkm000]

The CMake support is very experimental, and has been written in an old, 2.x style. I'm afraid we cannot support it in general, and more so under Linux. It had been written long ago as a proof-of-concept. And we've all but dropped support for the gst plugin.

Under Linux, I suggest going normal configure and make route. You need to enable extra components in configure, IIRC, to include the login into compilation. It won't probably compile cleanly; if you come up with sensible, quality patches, please send a PR.

If you want to volunteer to improve our CMake build (the ultimate goal is to be able to use VSCode as the IDE for Kaldi), I'll appreciate that too. Some conceptual knowledge of the Modern CMake is required (google it). I commit to giving you a guidance if you want to commit to it, but right now I do not have free cycles to directly work on that by myself. A patch "improving it" in the old-CMake style has not been merged. but you may glean some pointers from it: #4481. The original author declined, as you may see.

Following the old CMake approach will be simply a wasted effort. CMake has improved dramatically since versions 2.x.

[vzxxbacq]

@kkm000 Thanks for your reply. Actually it works, we can use current CMake support to develop a plugin based on kaldi and gst with little modifications (like add -fPIC or change some vars). But as you said, it isn't intuitive to understand for me because I just learned CMake 3.x, if kaldi community is looking for a better CMake build based on 3.x, I'm happy to work on it if I can.

[danpovey]

That sounds great as far as I am concerned!

…

On Sat, May 15, 2021 at 9:19 PM Fang Huangqiang ***@***.***> wrote: @kkm000 <https://github.com/kkm000> Thanks for your reply. Actually it works, we can use current CMake Support to develop a plugin based kaldi and gst with little modifications (like add -fPIC or change some vars). But as you said, it isn't intuitive to understand for me because I just learned CMake 3.x, if kaldi community is looking for a better CMake build based on 3.x, I'm happy to work on it if I can. — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#4529 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAZFLO5RXNPX7MMV3G766K3TNZYFHANCNFSM443GPKQQ> .

[kkm000]

@vzxxbacq, thank you, sounds amazing! Could you please open a PR with your cleanup?

Whether to keep the location of OpenFST cached or not is up to you. Looking it up every cmake run costs nothing, because we exactly know where to look, so either way is fine.

[kkm000]

@vzxxbacq, friendly ping. If you have time share the changes that you've already implemented, we'd sure thing appreciate them!

[vzxxbacq]

@kkm000 sry for my late response, I've been working overtime for half a month :(

you can check the commit at fix cmake

I changed the OpenFST URL to my repo because the official repo used the absolute path in the CMakeLists.txt of the test module so that we can't use it as an external project. I have posted a PR about it.