Linking to cmake project that links to other cmake projects

help
1

I'm using the cmake crate to compile a CMake project which depends and compiles other CMake projects

This is my build.rs:

extern crate cmake;
use cmake::Config;

fn main() {
    let dst = Config::new("src/cpp")
        .define("COMPILE_TARGET", "DESKTOP_x86_64")
        .define("FLAVOR", "DESKTOP")
        .define("LIBOPENVPN3_NOT_BUILD_EXAMPLES", "TRUE")
        .build();

    println!("cargo:rustc-link-search=native={}", dst.display());
    println!("cargo:rustc-link-lib=static=libopenvpn3");
    println!("cargo:rustc-link-lib=dylib=stdc++");
}

This is how my src/cpp/CMakeLists.txt compiles libopenvpn3

add_library(libopenvpn3 SHARED OpenVpnInstance.cpp)
target_link_libraries(libopenvpn3 crypto ssl lzo lz4 tins)

However, when I build with cargo build, I get undefined references to objects from all these libraries: crypto ssl lzo lz4 tins.

I also tried making libopenvpn3 STATIC so the final libopenvpn3 will include all of the needed libraries: crypto, ssl, lzo, lz4, tins, like this: add_library(libopenvpn3 STATIC OpenVpnInstance.cpp) but I still get the error. I think the other libraries (crypto, ssl, lzo, lz4, tins) will only be included together if they are static too. Or not?

Anyways, I think that I should relink with these libraries on build.rs, like this:

println!("cargo:rustc-link-lib=dylib=openvpn");
println!("cargo:rustc-link-lib=dylib=crypto");
println!("cargo:rustc-link-lib=dylib=lzo");
println!("cargo:rustc-link-lib=dylib=lz4");
println!("cargo:rustc-link-lib=dylib=tins");

but I don't know where they are, because they are generated from CMakeLists.txt, and I don't think hardcoding the path to where they are generated is a good idea.

What should I do here?

2

On the CMakeLists.txt, I was doing:

install(TARGETS libopenvpn3 DESTINATION .)

but then I did

install(TARGETS libopenvpn3 crypto ssl lzo lz4 tins DESTINATION .)

so it installs all the libs needed

Then, this build.rs works:

extern crate cmake;
use cmake::Config;

fn main() {
    let dst = Config::new("src/cpp")
        .define("COMPILE_TARGET", "DESKTOP_x86_64")
        .define("FLAVOR", "DESKTOP")
        .define("LIBOPENVPN3_NOT_BUILD_EXAMPLES", "TRUE")
        .build();

    println!("cargo:rustc-link-search=native={}", dst.display());
    println!("cargo:rustc-link-lib=dylib=stdc++");
    println!("cargo:rustc-link-lib=static=libopenvpn3");
    println!("cargo:rustc-link-lib=static=crypto");
    println!("cargo:rustc-link-lib=static=lzo");
    println!("cargo:rustc-link-lib=static=lz4");
    println!("cargo:rustc-link-lib=static=tins");
    println!("cargo:rustc-link-lib=static=ssl");
}

I don't know, however, why I have to link them again in Rust. They should be included in libopenvpn3 since they are static, shouldn't them?

3

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