fixup! test(core.utils): guard against drift between cache + Program.compile target matrices

Author: cpcloud

cuda_core/tests/test_program_cache.py

@@ -268,6 +268,51 @@ def test_make_program_cache_key_rejects(kwargs, exc_type, match):
         _make_key(**kwargs)
 
 
+def test_make_program_cache_key_supported_targets_matches_program_compile():
+    """``_SUPPORTED_TARGETS_BY_CODE_TYPE`` duplicates the backend target
+    matrix in ``_program.pyx``. Guard against drift: parse the pyx source,
+    extract its SUPPORTED_TARGETS dict, and assert the two views agree for
+    every code_type."""
+    import ast
+    from pathlib import Path
+
+    from cuda.core.utils._program_cache import _SUPPORTED_TARGETS_BY_CODE_TYPE
+
+    # Map Program._backend strings to the public code_type values.
+    backend_to_code_type = {"NVRTC": "c++", "NVVM": "nvvm"}
+    linker_backends = ("nvJitLink", "driver")
+
+    pyx = Path(__file__).parent.parent / "cuda" / "core" / "_program.pyx"
+    text = pyx.read_text()
+    # Find the assignment: ``cdef dict SUPPORTED_TARGETS = { ... }``.
+    marker = "cdef dict SUPPORTED_TARGETS"
+    start = text.index(marker)
+    brace = text.index("{", start)
+    # Find the matching closing brace.
+    depth = 0
+    for idx in range(brace, len(text)):
+        if text[idx] == "{":
+            depth += 1
+        elif text[idx] == "}":
+            depth -= 1
+            if depth == 0:
+                end = idx + 1
+                break
+    pyx_targets = ast.literal_eval(text[brace:end])
+
+    # NVRTC and NVVM map 1:1 to their code_types.
+    for backend, code_type in backend_to_code_type.items():
+        assert frozenset(pyx_targets[backend]) == _SUPPORTED_TARGETS_BY_CODE_TYPE[code_type], (
+            backend,
+            code_type,
+        )
+    # Both linker backends ultimately serve code_type="ptx"; they should
+    # agree with each other and with the cache table.
+    linker_sets = [frozenset(pyx_targets[b]) for b in linker_backends]
+    assert all(s == linker_sets[0] for s in linker_sets)
+    assert linker_sets[0] == _SUPPORTED_TARGETS_BY_CODE_TYPE["ptx"]
+
+
 @pytest.mark.parametrize(
     "code_type, code, target_type",
     [