Inject necessary RUNPATH klint can work without LD_LIBRARY_PATH

Author: nbdd0121

README.md

@@ -20,10 +20,7 @@ cargo install --path .
 
 Note that klint currently is pinned to a Rust version so it is likely that running `cargo install --git` will not work as it will not use the `rust-toolchain` file in the repository.
 
-To run this tool, use rustup which will prepare the necessary environment variables:
-```
-rustup run nightly klint
-```
+To run this tool for Linux kernel build, use `make RUSTC=<path to klint>` to use klint in place of a Rust compiler.
 
 klint is developed against latest nightly rustc; if you would like to use it with a stable Rust version, check the tagged releases.
 

build.rs

@@ -0,0 +1,20 @@
+fn probe_sysroot() -> String {
+    std::process::Command::new("rustc")
+        .arg("--print")
+        .arg("sysroot")
+        .output()
+        .ok()
+        .and_then(|out| String::from_utf8(out.stdout).ok())
+        .map(|x| x.trim().to_owned())
+        .expect("failed to probe rust sysroot")
+}
+
+fn main() {
+    // No need to rerun for other changes.
+    println!("cargo::rerun-if-changed=build.rs");
+
+    // Probe rustc sysroot. Although this is automatically added when using Cargo, the compiled
+    // binary would be missing the necessary RPATH so it cannot run without using Cargo.
+    let sysroot = probe_sysroot();
+    println!("cargo::rustc-link-arg=-Wl,-rpath={sysroot}/lib");
+}