[ITK-users] ITK emscripten compilation

[Matt McCormick]

Hi Juan,

> I have build ITK as described in post 912
> http://www.kitware.com/blog/home/post/912
>
> However, I did not use ninja and I added the flag -D_LARGEFILE64_SOURCE=1,
> i.e.,
>
> flags=' -Wno-warn-absolute-paths --memory-init-file 0 -s
> DISABLE_EXCEPTION_CATCHING=0 -s ALLOW_MEMORY_GROWTH=1
> -D_LARGEFILE64_SOURCE=1'
>
> cmake -DCMAKE_TOOLCHAIN_FILE=${CMAKE_TOOLCHAIN_FILE} \
>   "-DCMAKE_CXX_FLAGS=$flags" "-DCMAKE_C_FLAGS=$flags" \
>   -DBUILD_EXAMPLES=OFF \
>
>     ../ITK
>
>
> make
>
>
> This flag is needed to avoid the error while compiling itkhdf5:
>
>
> /usr/src/ITK/Modules/ThirdParty/HDF5/src/itkhdf5/src/H5FDstdio.c:192:5:
> error: use of undeclared identifier 'off64_t'
>
>
> After I added the flag, the compilation is successful.

This is interesting.  Are you using the Docker image? What version of
Emscripten are you using? This is supposed to avoided with this code
block:

  https://github.com/InsightSoftwareConsortium/ITK/blob/2f2ae65eec72701b0fc69c07b59453cc6ac2e575/Modules/ThirdParty/HDF5/src/itkhdf5/config/cmake/ConfigureChecks.cmake#L294-L304

What is CMAKE_SYSTEM?



> Now, I'm trying to build a project using ITK.
>
>
> The cmake configuration process is similar to ITK, and the compilation is
> also successful. The javascript file is generated as expected.

Cool.


> However, the execution produces the following error while on the docker
> machine:
>
>
> Could not create IO object for reading file someImage.nrrd
> The file doesn't exist.
> Filename = someImage.nrrd
>
>
> The image file is in the same built directory (not a problem of read-write
> permissions).

You'll need to mount directories from the local filesystem that you
want the Javascript code to see with NODEFS [1].  See how we do it for
the ITK test driver [2].

HTH,
Matt


[1] https://kripken.github.io/emscripten-site/docs/api_reference/Filesystem-API.html#file-systems

[2] http://itk.org/gitweb?p=ITK.git;a=commit;h=0c82b97b749cea9f409aba99c918b94295ed24c7