Pin external shader bundle in lighting measurements

tests/test_p3_lighting_benchmark.py

@@ -98,6 +98,26 @@ with path.open("w", newline="", encoding="utf-8") as stream:
 
 
 class LightingBenchmarkTests(unittest.TestCase):
+    def test_native_shader_bundle_manifest_tracks_loaded_spirv_and_reflection(self):
+        from benchmark_p3_lighting import _shader_bundle_manifest
+
+        with tempfile.TemporaryDirectory() as temporary:
+            root = Path(temporary)
+            binary = root / "faset_p3_lighting_benchmark"
+            binary.write_bytes(b"native fixture")
+            shaders = root / "shaders"
+            shaders.mkdir()
+            with self.assertRaisesRegex(ValueError, "shader bundle"):
+                _shader_bundle_manifest(binary)
+            for name in ("vertexMain.spv", "fragmentMain.spv",
+                         "fragmentMain.reflection.json", "tileBuild.spv"):
+                (shaders / name).write_bytes(name.encode())
+            before = _shader_bundle_manifest(binary)
+            self.assertEqual(set(before), {"vertexMain.spv", "fragmentMain.spv",
+                                           "fragmentMain.reflection.json", "tileBuild.spv"})
+            (shaders / "tileBuild.spv").write_bytes(b"modified tile shader")
+            self.assertNotEqual(_shader_bundle_manifest(binary), before)
+
     def test_list_runs_has_three_independent_repeats_for_each_shadow_setting(self):
         process = subprocess.run([sys.executable, SCRIPT, "--list-runs"],
                                  text=True, capture_output=True, check=True)
@@ -215,6 +235,7 @@ class LightingBenchmarkTests(unittest.TestCase):
             self.assertEqual(report["rows"], 54 * 30)
             self.assertTrue(report["forward_plus_gate"]["triggered"])
             self.assertEqual(report["benchmark_sha256"], hashlib.sha256(fake.read_bytes()).hexdigest())
+            self.assertIsNone(report["shader_bundle"])
             self.assertEqual(report["source_revision"], revision)
             self.assertFalse(report["source_dirty"])
             one = json.loads(next((output / "raw").glob("*.args.json")).read_text())

tools/benchmark_p3_lighting.py

@@ -238,6 +238,22 @@ def _binary_sha256(path: Path) -> str:
         return hashlib.file_digest(stream, "sha256").hexdigest()
 
 
+def _shader_bundle_manifest(executable: Path) -> dict[str, str] | None:
+    # Test fixtures are Python programs. A native renderer loads SPIR-V from
+    # the shader directory beside its executable before checking other roots.
+    if executable.suffix.lower() == ".py":
+        return None
+    directory = executable.parent / "shaders"
+    required = ("vertexMain.spv", "fragmentMain.spv")
+    if not all((directory / name).is_file() for name in required):
+        raise ValueError(f"Benchmark shader bundle is missing beside {executable}")
+    files = sorted((path for path in directory.iterdir()
+                    if path.is_file() and
+                    (path.suffix == ".spv" or path.name.endswith(".reflection.json"))),
+                   key=lambda path: path.name)
+    return {path.name: _binary_sha256(path) for path in files}
+
+
 def _clean_source_revision(root: Path, expected: str) -> str:
     revision = subprocess.check_output(["git", "-C", str(root), "rev-parse", "HEAD"],
                                        text=True).strip()
@@ -260,6 +276,7 @@ def sweep(executable: Path, output: Path, shadows: str, commit: str,
     source = (source_root or Path(__file__).resolve().parents[1]).resolve()
     revision = _clean_source_revision(source, commit)
     binary_sha256 = _binary_sha256(executable)
+    shader_manifest = _shader_bundle_manifest(executable)
     if output.exists() and any(output.iterdir()):
         raise ValueError(f"Output directory must be new or empty: {output}")
     raw = output / "raw"
@@ -312,14 +329,17 @@ def sweep(executable: Path, output: Path, shadows: str, commit: str,
                                                     "acquisition_index"])
         writer.writeheader()
         writer.writerows(all_rows)
-    if _binary_sha256(executable) != binary_sha256 or _clean_source_revision(source, commit) != revision:
+    if (_binary_sha256(executable) != binary_sha256 or
-        raise ValueError("Benchmark binary or source changed during the sweep")
+            _shader_bundle_manifest(executable) != shader_manifest or
+            _clean_source_revision(source, commit) != revision):
+        raise ValueError("Benchmark binary, shader bundle or source changed during the sweep")
     summary = {"format": "faset.p3-lighting-benchmark", "version": 1,
                "commit": commit, "warmup_frames_per_run": WARMUP_FRAMES,
                "measured_frames_per_run": MEASURED_FRAMES, "width": WIDTH, "height": HEIGHT,
                "validation": validation, "driver": driver,
                "source_revision": revision, "source_root": str(source), "source_dirty": False,
                "benchmark_sha256": binary_sha256,
+               "shader_bundle": shader_manifest,
                "device": identity[0], "lighting_path": identity[2],
                "validation_enabled": identity[3] == "1", "build_configuration": identity[4],
                "run_order": run_order,