gen-c-dynamical-library-using-rust-and-call

使用rust生成动态库cdylib

layout

├── Cargo.lock
├── Cargo.toml
└── src
    └── lib.rs

Cargo.toml

[lib]
name = "rustdll" #生成dll的文件名
crate-type = ["cdylib"]

lib.rs

#[no_mangle]
pub extern fn gettime() {
    let input = 4;
  println!("from rust dll {}",input)

build之后，在Windows平台会生成两个文件 rustdll.dll可导入路``rustdll.dll.lib ；而在Linux平台生成文件librustdll.so`

调用由rust生成的动态库里的函数

layout

aa/
├── Cargo.lock
├── Cargo.toml
├── build.rs
├── lib
│   └── librustdll.so
└── src
    └── main.rs

LInux

build.rs

fn main() {
 // indicate dynamical library
    println!("cargo:rustc-link-lib=dylib=rustdll");
   // search lib directory,relative path is also ok
    println!("cargo:rustc-link-search=native=/home/ubuntu/aa/lib");
}

src/main.rs

和 build.rs 中的cargo:rustc-link-lib 二选一
//#[link(name = "rustdll")]
extern {
    fn gettime();
}
fn main() {
    unsafe {
        gettime();

    }
}

build command

if cargo build,可以编译但link error

ldd target/debug/aa
       linux-vdso.so.1 (0x00007ffd5b12d000)
       librustdll.so => not found

add new flags

cargo rustc -- -C link-args="-Wl,-rpath,/home/ubuntu/aa/lib/"

Windows

src/main.rs

和 build.rs 中的cargo:rustc-link-lib 二选一
//#[link(name = "rustdll.dll")]
extern {
    fn gettime();
}
fn main() {
    unsafe {
        gettime();

    }
}

build.rs

fn main() {
    // search import library .lib
 // indicate dynamical library
    println!("cargo:rustc-link-lib=dylib=rustdll.dll");
   // search lib directory,relative path is also ok
    println!("cargo:rustc-link-search=native=..");
}

将rustdll.dll和rustdll.dll.lib放在和aa同目录下，执行cargo build

完成后，将可执行文件和动态库文件放在同一文件夹下即可

Reference

Linking Rust application with a dynamic library not in the runtime linker search path