Python: Add script to process results from MRVA (bqrs files)

Also makes `empty.model.yml` empty once again

python/ql/src/meta/ClassHierarchy/process-mrva-results.py

@@ -0,0 +1,68 @@
+#!/usr/bin/env python3
+
+import sys
+import glob
+from pathlib import Path
+import json
+import subprocess
+from collections import defaultdict
+import yaml
+
+VERSION = "process-mrva-results 0.0.1"
+
+mad_path = Path(__file__).parent.parent.parent.parent / "lib/semmle/python/frameworks/data/internal/"
+
+assert mad_path.exists(), mad_path
+
+package_data = defaultdict(set)
+
+# gather data
+for f in glob.glob(f"{sys.argv[1]}/**/results/results.bqrs", recursive=True):
+    print(f"Processing {f}")
+
+    json_data = subprocess.check_output(["codeql", "bqrs", "decode", "--format=json", f])
+    select = json.loads(json_data)
+
+    for t in select["#select"]["tuples"]:
+        pkg = t[1]
+        package_data[pkg].add(tuple(t))
+
+# process data
+
+def wrap_in_template(data):
+    return {
+        "extensions": [
+            {
+                "addsTo": {
+                    "pack": "codeql/python-all",
+                    "extensible": "typeModel",
+                },
+                "data": data,
+            }
+        ]
+    }
+
+def parse_from_file(path):
+    if not path.exists():
+        return set()
+
+    text = path.read_text()
+    assert text.startswith(f"# {VERSION}\n"), f"{path}: {text[:100]}"
+
+    raw_data = yaml.safe_load(text)
+    assert len(raw_data["extensions"]) == 1, path
+    assert raw_data["extensions"][0]["addsTo"]["extensible"] == "typeModel", path
+
+    return set(tuple(x) for x in raw_data["extensions"][0]["data"])
+
+for pkg in package_data:
+    pkg_path = mad_path / f"auto-{pkg}.model.yml"
+
+    all_data = parse_from_file(pkg_path)
+    all_data.update(package_data[pkg])
+
+    as_lists = [list(t) for t in all_data]
+
+    data_for_yaml = wrap_in_template(as_lists)
+
+    pkg_path.write_text(f"# {VERSION}\n" + yaml.dump(data_for_yaml, indent=2))