feat: add build sha to parser.c header comment

cli/build.rs

@@ -60,6 +60,8 @@ fn web_playground_files_present() -> bool {
     paths.iter().all(|p| Path::new(p).exists())
 }
 
+// When updating this function, don't forget to also update generate/build.rs which has a
+// near-identical function.
 fn read_git_sha() -> Option<String> {
     let crate_path = PathBuf::from(env::var("CARGO_MANIFEST_DIR").unwrap());
 

cli/generate/build.rs

@@ -0,0 +1,32 @@
+use std::{env, path::PathBuf, process::Command};
+
+fn main() {
+    if let Some(git_sha) = read_git_sha() {
+        println!("cargo:rustc-env=BUILD_SHA={git_sha}");
+    }
+}
+
+// This is copied from the build.rs in parent directory. This should be updated if the
+// parent build.rs gets fixes.
+fn read_git_sha() -> Option<String> {
+    let crate_path = PathBuf::from(env::var("CARGO_MANIFEST_DIR").unwrap());
+
+    if !crate_path
+        .parent()?
+        .parent()
+        .map_or(false, |p| p.join(".git").is_dir())
+    {
+        return None;
+    }
+
+    Command::new("git")
+        .args(["rev-parse", "HEAD"])
+        .current_dir(crate_path)
+        .output()
+        .map_or(None, |output| {
+            if !output.status.success() {
+                return None;
+            }
+            Some(String::from_utf8_lossy(&output.stdout).to_string())
+        })
+}

cli/generate/src/render.rs

@@ -19,8 +19,9 @@ use super::{
 const SMALL_STATE_THRESHOLD: usize = 64;
 const ABI_VERSION_MIN: usize = 14;
 const ABI_VERSION_MAX: usize = tree_sitter::LANGUAGE_VERSION;
-const BUILD_VERSION: &str = env!("CARGO_PKG_VERSION");
 const ABI_VERSION_WITH_METADATA: usize = 15;
+const BUILD_VERSION: &str = env!("CARGO_PKG_VERSION");
+const BUILD_SHA: Option<&'static str> = option_env!("BUILD_SHA");
 
 macro_rules! add {
     ($this: tt, $($arg: tt)*) => {{
@@ -280,9 +281,13 @@ impl Generator {
     }
 
     fn add_header(&mut self) {
+        let version = BUILD_SHA.map_or_else(
+            || BUILD_VERSION.to_string(),
+            |build_sha| format!("{BUILD_VERSION} ({build_sha})"),
+        );
         add_line!(
             self,
-            "// Automatically generated by tree-sitter v{BUILD_VERSION}"
+            "/* Automatically generated by tree-sitter v{version} */",
         );
         add_line!(self, "");
     }