build.rs

Author: RandyMcMillan

build.rs

@@ -1,4 +1,41 @@
-use std::process::exit;
-fn main() -> () {
-    exit(0)
+fn main() {
+    let git_output = std::process::Command::new("git")
+        .args(["rev-parse", "--git-dir"])
+        .output()
+        .ok();
+    let git_dir = git_output.as_ref().and_then(|output| {
+        std::str::from_utf8(&output.stdout)
+            .ok()
+            .and_then(|s| s.strip_suffix('\n').or_else(|| s.strip_suffix("\r\n")))
+    });
+
+    // Tell cargo to rebuild if the head or any relevant refs change.
+    if let Some(git_dir) = git_dir {
+        let git_path = std::path::Path::new(git_dir);
+        let refs_path = git_path.join("refs");
+        if git_path.join("HEAD").exists() {
+            println!("cargo:rerun-if-changed={}/HEAD", git_dir);
+        }
+        if git_path.join("packed-refs").exists() {
+            println!("cargo:rerun-if-changed={}/packed-refs", git_dir);
+        }
+        if refs_path.join("heads").exists() {
+            println!("cargo:rerun-if-changed={}/refs/heads", git_dir);
+        }
+        if refs_path.join("tags").exists() {
+            println!("cargo:rerun-if-changed={}/refs/tags", git_dir);
+        }
+    }
+
+    let git_output = std::process::Command::new("git")
+        .args(["describe", "--always", "--tags", "--long", "--dirty"])
+        .output()
+        .ok();
+    let git_info = git_output
+        .as_ref()
+        .and_then(|output| std::str::from_utf8(&output.stdout).ok().map(str::trim));
+
+    if let Some(git_info) = git_info {
+        println!("cargo:rustc-env=_GIT_INFO={}", git_info);
+    }
 }