detect-version: Fix releng logic when subproject

scripts/detect-version.py

@@ -1,18 +1,40 @@
 import json
+import os
 from pathlib import Path
 import sys
+from typing import Iterator
 
 
-def main():
-    root_dir = Path(__file__).parent.parent.resolve()
-    pkg_data = json.loads((root_dir / "package.json").read_text(encoding="utf-8"))
-    version = pkg_data["version"]
+SOURCE_ROOT = Path(__file__).resolve().parent.parent
+
+
+def detect_version() -> str:
+    pkg = json.loads((SOURCE_ROOT / "package.json").read_text(encoding="utf-8"))
+    version = pkg["version"]
     if version == "0.0.0":
-        sys.path.insert(0, str(root_dir))
-        from releng.frida_version import detect
-        version = detect(root_dir).name
-    print(version)
+        releng_location = next(enumerate_releng_locations(), None)
+        if releng_location is not None:
+            sys.path.insert(0, str(releng_location.parent))
+            from releng.frida_version import detect
+            version = detect(SOURCE_ROOT).name
+    return version
+
+
+def enumerate_releng_locations() -> Iterator[Path]:
+    val = os.environ.get("MESON_SOURCE_ROOT")
+    if val is not None:
+        parent_releng = Path(val) / "releng"
+        if releng_location_exists(parent_releng):
+            yield parent_releng
+
+    local_releng = SOURCE_ROOT / "releng"
+    if releng_location_exists(local_releng):
+        yield local_releng
+
+
+def releng_location_exists(location: Path) -> bool:
+    return (location / "frida_version.py").exists()
 
 
 if __name__ == "__main__":
-    main()
+    print(detect_version())