CODEWITHSUNDEEP
shared-librariesrustrust-cargo
luke
luke

Reputation: 1074

Proper way to make and use Rust shared libraries?

I am working on bindings for a cpp library. To do this I wrote a capi / wrapper for the library and compiled that to a shared lib (.so file).

My question is, how do I then use and integrate this file into cargo without forcing the user to install it? Currently I build the cpp via a Makefile called from the build variable in Cargo.toml, but I am unsure what to do with the compiled lib.

For testing, I can either use rpath or LD_LIBRARY_PATH to point the executable to the right location, but this will not work when distributing a library.

How are people managing this?

Upvotes: 5

Views: 7459

Answers (1)

Vladimir Matveev
Vladimir Matveev

Reputation: 127711

First of all, determine whether you really need a shared library. It's not clear from your question, but if you compiled your own wrapper into a shared library, that's probably unnecessary - you can compile your code into a static library and link it directly into your executable.

Moreover, you can try to link that third-party library statically too. I don't think this should be hard. And yes, you need to use build command in the manifest to do all of this now.

However, if you still need to use a shared library and you don't want the end user to install it herself (which is strange, because that's the point of shared libraries), you have to distribute it manually. For example, you can write a makefile which assembles an archive which your users may extract and use. For your program to find the library correctly you will either have the user to install this archive into the system root directory (e.g. /usr on linux; then this shared library will be located automatically) or you will have to write small shell script wrapper around your executable which will locate the shared library and set appropriate LD_LIBRARY_PATH.

I'd go for the first path. Usually all major platforms provide means to create installation packages (deb/rpm/pkg.tar.xz/whatever on Linux, brew on Mac, windows installer on Windows, though on Windows you can just put your shared library in the same directory as the executable and it will work). You just have to create packages for the platform your users work on, so your program will be installed in correct directories and your shared library will be resolved automatically.

Upvotes: 5

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