more builtin variables

1 files changed, 41 insertions, 0 deletions

diff --git a/build.rs b/build.rs
new file mode 100644
index 0000000..95a5eae
--- /dev/null
+++ b/build.rs
@@ -0,0 +1,41 @@
+use std::process::Command;
+
+fn git(args: &[&str]) -> String {
+    let output = Command::new("git")
+        .args(args)
+        .output()
+        .expect("failed to execute git");
+
+    if !output.status.success() {
+        panic!("git command failed: git {}", args.join(" "));
+    }
+
+    String::from_utf8(output.stdout)
+        .expect("git output not utf8")
+        .trim()
+        .to_string()
+}
+
+fn main() {
+    // Re-run if HEAD changes
+    println!("cargo:rerun-if-changed=.git/HEAD");
+    println!("cargo:rerun-if-changed=.git/refs");
+
+    let git_hash = git(&["rev-parse", "HEAD"]);
+    let git_hash_short = git(&["rev-parse", "--short", "HEAD"]);
+
+    let git_dirty = {
+        let status = Command::new("git")
+            .args(["diff", "--quiet"])
+            .status()
+            .expect("failed to check git dirty state");
+
+        if status.success() { false } else { true }
+    };
+
+    println!("cargo:rustc-env=GIT_HASH={git_hash}");
+    println!("cargo:rustc-env=GIT_HASH_SHORT={git_hash_short}");
+    if git_dirty {
+        println!("cargo:rustc-env=GIT_DIRTY=1");
+    }
+}