regenerate and symlink a single master vmlinux.py for make test

- make test/test-cov/test-verifier now depend on a 'vmlinux' target that
  regenerates vmlinux.py from the running kernel's BTF and symlinks it
  into every directory under tests/, replacing the stale, duplicated
  vmlinux.py fixtures that used to be committed there.
- collector.py now skips the 'vmlinux.py' filename when collecting BPF
  test cases, since it's a fixture module, not a test program - it was
  previously being mis-collected and compiled as a bogus test.
- functions_pass.py: llvmlite >=0.49 renamed the 'nocapture' argument
  attribute to 'captures(none)'.

Author: varun-r-mallya

Makefile

@@ -6,18 +6,29 @@ clean:
 	rm -rf examples/*.ll examples/*.o
 	rm -rf htmlcov .coverage
 
-test:
+# Regenerate the master vmlinux.py from the running kernel's BTF, then
+# symlink it into every directory under tests/ so both pytest (which
+# resolves "import vmlinux" via pythonpath=["."]) and any test file run
+# standalone from its own directory see the same, always-fresh fixture.
+vmlinux:
+	python3 tools/vmlinux-gen.py -o vmlinux.py
+	@find tests -type d -not -path '*/__pycache__*' | while read -r d; do \
+		target=$$(python3 -c "import os,sys; print(os.path.relpath('vmlinux.py', sys.argv[1]))" "$$d"); \
+		ln -sf "$$target" "$$d/vmlinux.py"; \
+	done
+
+test: vmlinux
 	pytest tests/ -W ignore::DeprecationWarning -v --tb=short -m "not verifier"
 
-test-cov:
+test-cov: vmlinux
 	pytest tests/ -W ignore::DeprecationWarning -v --tb=short -m "not verifier" \
 		--cov=pythonbpf --cov-report=term-missing --cov-report=html
 
-test-verifier:
+test-verifier: vmlinux
 	@echo "NOTE: verifier tests shell out to 'sudo bpftool'; run 'sudo -v' first so"
 	@echo "      the timestamp does not lapse mid-run. bpftool must be installed."
 	pytest tests/test_verifier.py -W ignore::DeprecationWarning -v --tb=short -m verifier
 
 all: clean install
 
-.PHONY: all clean install test test-cov test-verifier
+.PHONY: all clean install test test-cov test-verifier vmlinux

pythonbpf/functions/functions_pass.py

@@ -403,7 +403,7 @@ def process_bpf_chunk(func_node, compilation_context, return_type):
     if func_node.args.args:
         # Only look at the first argument for now
         param = func.args[0]
-        param.add_attribute("nocapture")
+        param.add_attribute("captures(none)")
 
     probe_string = get_probe_string(func_node)
     if probe_string is not None:

tests/framework/collector.py

@@ -35,6 +35,10 @@ def collect_all_test_files() -> list[BpfTestCase]:
     cases = []
     for subdir in ("passing_tests", "failing_tests"):
         for py_file in sorted((TESTS_DIR / subdir).rglob("*.py")):
+            if py_file.name == "vmlinux.py":
+                # Not a test case: the per-directory symlink to the master
+                # vmlinux fixture module, kept alongside tests that import it.
+                continue
             rel = str(py_file.relative_to(TESTS_DIR))
             needs_vmlinux = _is_vmlinux_test(rel)