Generate git revision to a header file.

extra/git-ref.py

@@ -0,0 +1,24 @@
+#!/bin/env python3
+
+import filecmp
+import subprocess
+import os
+
+out = "GitRef.hpp"
+tmp = f"{out}.tmp"
+
+try:
+    ref = subprocess.run(["git", "rev-parse", "--short", "HEAD"], check=True, capture_output=True).stdout.decode().strip()
+except subprocess.CalledProcessError:
+    ref = "unknown"
+
+if not os.path.exists(out):
+    with open(out, "w") as f:
+        print(f"#pragma once\n\nnamespace tracy {{ static inline const char* GitRef = \"{ref}\"; }}", file=f)
+else:
+    with open(tmp, "w") as f:
+        print(f"#pragma once\n\nnamespace tracy {{ static inline const char* GitRef = \"{ref}\"; }}", file=f)
+    if not filecmp.cmp(out, tmp, shallow=False):
+        os.replace(tmp, out)
+    else:
+        os.unlink(tmp)