feat: call rust ffi from go

build.rs

@@ -0,0 +1,33 @@
+// Adapted from https://michael-f-bryan.github.io/rust-ffi-guide/cbindgen.html
+extern crate cbindgen;
+
+use std::env;
+use std::path::PathBuf;
+
+fn main() {
+    let crate_dir = env::var("CARGO_MANIFEST_DIR").unwrap();
+
+    let package_name = env::var("CARGO_PKG_NAME").unwrap();
+    let output_file = target_dir()
+        .join(format!("{}.h", package_name))
+        .display()
+        .to_string();
+
+    cbindgen::Builder::new()
+        .with_crate(crate_dir)
+        .with_language(cbindgen::Language::C)
+        .generate()
+        .unwrap()
+        .write_to_file(&output_file);
+}
+
+/// Find the location of the `target/` directory. Note that this may be
+/// overridden by `cmake`, so we also need to check the `CARGO_TARGET_DIR`
+/// variable.
+fn target_dir() -> PathBuf {
+    if let Ok(target) = env::var("CARGO_TARGET_DIR") {
+        PathBuf::from(target)
+    } else {
+        PathBuf::from(env::var("CARGO_MANIFEST_DIR").unwrap()).join("target")
+    }
+}