compiler: one build_module/set_params path for all three module owners

Simulation, PeriodicBlockStepper and FixedPatchStepper levels each repeated
generate_config -> compile_kernel -> load_module -> cleanup and the
d_params pack/upload. They now call compiler.build_module(cfg, entry,
arch=..., n_objects=..., block_root_bc=...) and compiler.set_params.
Simulation no longer keeps its build directory alive until close (nothing
read it after loading). Removes the unused compile_kernel_v2 alias.
Host fakes and lifecycle tests follow the new seam; the close-retry case
for build-directory cleanup goes with the removed cleanup step.
No kernel, numerical or launch change.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

tests/unit/test_block_step_sync.py

@@ -37,7 +37,7 @@ def backend():
     module.get_global.return_value = (Mock(), 20)
     module.get_function.side_effect = lambda name: Mock(
         side_effect=lambda *a, **k: log.append((name, a[:2])))
-    host.compiler.load_module.return_value = module
+    host.compiler.build_module.return_value = module
     cfg = LBMConfig(nx=16, ny=16, viscosity=.1)
     run = host.PeriodicBlockStepper(cfg, BlockLayout2D.build(16, 16, 8, 8),
                                     context=Mock(activate=nullcontext, sm_arch="sm_70"))

tests/unit/test_channel_root.py

@@ -74,7 +74,7 @@ def test_evolved_ghost_snapshot_and_physical_download():
     from .test_refinement_three_level_multipatch import host_module
     host = host_module()
     storage = {}
-    host.compiler.load_module.return_value.get_global.side_effect = lambda name: (name, 12 if name == "d_block_channel" else 20)
+    host.compiler.build_module.return_value.get_global.side_effect = lambda name: (name, 12 if name == "d_block_channel" else 20)
     host.cuda.mem_alloc.side_effect = lambda size: Mock()
     host.cuda.memcpy_htod.side_effect = lambda ptr, a: storage.__setitem__(id(ptr), np.array(a, copy=True))
     host.cuda.memcpy_dtoh.side_effect = lambda a, ptr: np.copyto(a, storage[id(ptr)])
@@ -96,7 +96,7 @@ def test_evolved_ghost_snapshot_and_physical_download():
         arrays[0][0, 0, 0] = np.nan
         with pytest.raises(ValueError, match="finite"):
             backend.initialize(*arrays)
-        assert backend._levels[0].kernel == host.compiler.load_module.return_value.get_function("BlockChannelStep")
-        assert [call.kwargs["block_root_bc"] for call in host.compiler.generate_config.call_args_list] == [2, 0]
+        assert backend._levels[0].kernel == host.compiler.build_module.return_value.get_function("BlockChannelStep")
+        assert [call.kwargs["block_root_bc"] for call in host.compiler.build_module.call_args_list] == [2, 0]
     finally:
         backend.close()

tests/unit/test_projected_pair_stepper.py

@@ -29,7 +29,7 @@ def backend(**options):
             name=name, side_effect=lambda *a, **kw: calls.append((name, a, kw)))
         return module
 
-    host.compiler.load_module.side_effect = load
+    host.compiler.build_module.side_effect = lambda *a, **k: load(None)
     host.cuda.memcpy_htod.side_effect = lambda ptr, a: storage.__setitem__(id(ptr), np.array(a, copy=True))
     host.cuda.memcpy_dtoh.side_effect = lambda a, ptr: np.copyto(a, storage[id(ptr)])
     cfg = options.pop('cfg', CFG)

tests/unit/test_raw_exchange.py

@@ -25,7 +25,7 @@ def backend(observe=True, obj=None):
     module = Mock()
     module.get_global.return_value = (Mock(), 20)
     module.get_function.side_effect = lambda name: Mock(side_effect=lambda *a, **k: calls.append((name, a, k)))
-    host.compiler.load_module.return_value = module
+    host.compiler.build_module.return_value = module
     host.cuda.mem_alloc.side_effect = lambda n: Mock(size=n)
     host.cuda.memcpy_dtoh.side_effect = lambda array, pointer: array.fill(0)
     ctx = Mock(activate=nullcontext, sm_arch='sm_70')

tests/unit/test_refinement_three_level_multipatch.py

@@ -193,9 +193,9 @@ def mock_backend(*, children=CHILDREN, bodies=False, fail_compile=False, fail_up
         gpu.get_function.side_effect=lambda name: Mock(name=name)
         gpu.get_global.side_effect=lambda name: (Mock(),20 if name=='d_params' else 16)
         return gpu
-    module.compiler.load_module.side_effect=load
+    module.compiler.build_module.side_effect=lambda *a,**k: load(None)
     if fail_compile:
-        module.compiler.compile_kernel.side_effect=['first','second',RuntimeError('L2 compile failed')]
+        module.compiler.build_module.side_effect=[load(None),load(None),RuntimeError('L2 compile failed')]
     if fail_upload:
         def upload(*args):
             if len(allocations)>20:

tests/unit/test_shifted_jets.py

@@ -62,7 +62,7 @@ class ShiftedJets(unittest.TestCase):
                     level_blocks=list(blocks),level_objects=[(),(),(body(),)],
                     level_jets=[(),(),(jet(),)])
         module.cuda.mem_alloc.assert_not_called()
-        module.compiler.compile_kernel.assert_not_called()
+        module.compiler.build_module.assert_not_called()
 
     def test_switch_upload_only_then_raw_remap_keeps_live_velocity(self):
         run,module,allocations,storage,objects=ready();clone=None

tests/unit/test_shifted_storage.py

@@ -135,7 +135,7 @@ class ShiftedStorage(unittest.TestCase):
             with self.assertRaisesRegex(ValueError,'all-blocked|blocked refined levels below'):
                 module.FixedPatchStepper(cfg,context=None,refinements=[(4,4,20,28)],
                                          level_blocks=blocks)
-        module.compiler.compile_kernel.assert_not_called()
+        module.compiler.build_module.assert_not_called()
 
     def test_uniform_block_codec_and_raw_snapshot(self):
         path = Path(backend.r.__file__).with_name('block_stepper.py')
@@ -151,7 +151,7 @@ class ShiftedStorage(unittest.TestCase):
         cuda.mem_get_info.return_value=(10**9,10**9)
         cuda.mem_alloc.side_effect=lambda size: Mock()
         gpu=Mock();gpu.get_global.return_value=(Mock(),20)
-        compiler.load_module.return_value=gpu
+        compiler.build_module.return_value=gpu
         context=Mock(activate=nullcontext,sm_arch='sm_70')
         layout=module.BlockLayout2D.build(16,16,4,4)
         cfg=replace(backend.CFG,nx=16,ny=16,ddf_shifting=True)

tests/unit/test_simulation_lifecycle.py

@@ -36,12 +36,10 @@ def make_simulation(monkeypatch):
     sim = module.Simulation.__new__(module.Simulation)
     sim.ctx = Owner()
     sim._closed = False
-    sim._build_dir = "private-build"
     for name in ("stepper", "bodies", "field", "_module", "_stream"):
         setattr(sim, name, object())
     monkeypatch.setattr(module, "cuda", SimpleNamespace(
         Context=SimpleNamespace(synchronize=lambda: None)))
-    monkeypatch.setattr(module.compiler, "cleanup_build_dir", lambda path: None)
     return sim
 
 
@@ -57,7 +55,7 @@ def test_close_inside_activation_preserves_resources(monkeypatch):
     assert sim._closed and sim.ctx.is_closed
 
 
-@pytest.mark.parametrize("failure", ["synchronize", "detach", "directory"])
+@pytest.mark.parametrize("failure", ["synchronize", "detach"])
 def test_close_failure_is_retryable(monkeypatch, failure):
     sim = make_simulation(monkeypatch)
     if failure == "detach":
@@ -68,17 +66,12 @@ def test_close_failure_is_retryable(monkeypatch, failure):
             calls.append(args)
             if len(calls) == 1:
                 raise RuntimeError(failure + " failed")
-        if failure == "synchronize":
-            monkeypatch.setattr(module.cuda.Context, "synchronize", fail_once)
-        else:
-            monkeypatch.setattr(module.compiler, "cleanup_build_dir", fail_once)
+        monkeypatch.setattr(module.cuda.Context, "synchronize", fail_once)
     with pytest.raises(RuntimeError, match="failed"):
         sim.close()
     assert not sim._closed
-    assert sim._build_dir == "private-build"
     sim.close()
     assert sim._closed and sim.ctx.is_closed
-    assert sim._build_dir is None
     sim.close()
 
 

tests/unit/test_step_sync.py

@@ -31,7 +31,7 @@ def backend(window=False):
     module.get_global.return_value = (Mock(), 20)
     module.get_function.side_effect = lambda name: Mock(
         side_effect=lambda *a, **k: log.append((name, a, k)))
-    host.compiler.load_module.return_value = module
+    host.compiler.build_module.return_value = module
     host.cuda.mem_alloc.side_effect = allocate
     host.cuda.memcpy_dtoh.side_effect = lambda array, pointer: array.fill(0)
     host.cuda.memset_d8_async.side_effect = lambda *a: log.append(("memset", a, {}))