diff options
| author | Ricardo B. Marlière <rbm@suse.com> | 2026-06-02 10:02:54 -0300 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2026-06-05 14:20:58 -0700 |
| commit | 5498e47741c8a742f730bf9996234bdae1c08ccc (patch) | |
| tree | e61516074b63f2153a636b5a47f2f1939246c8ab /tools | |
| parent | a97bfc9aae076f49f0bcad713bde02b87553b995 (diff) | |
selftests/bpf: Make skeleton headers order-only prerequisites of .test.d
The .test.d dependency files are generated by the C preprocessor and list
the headers each test file actually #includes. Skeleton headers appear in
those generated lists, so the .test.o -> .skel.h dependency is already
tracked by the .d file content.
Making skeletons order-only prerequisites of .test.d means that a missing
or skipped skeleton does not prevent .test.d generation, and regenerating a
skeleton does not force .test.d to be recreated. This avoids unnecessary
recompilation and, more importantly, avoids build errors when a skeleton
was intentionally skipped due to a BPF compilation failure.
$$(BPFOBJ) is intentionally kept as a normal prerequisite: a libbpf
rebuild legitimately invalidates .test.d, since libbpf header changes
can affect the headers .test.o sees. Only the skeleton headers are
moved to order-only.
Note that adding a new BPF skeleton via a modified existing local header
still works correctly: GNU make builds order-only prerequisites that do
not exist (the order-only qualifier only suppresses timestamp-driven
rebuilds, not existence-driven builds), so a brand-new .skel.h listed in
TRUNNER_BPF_SKELS is generated even when .test.d is otherwise up to date.
The modified local header invalidates .test.o through the previously
included .d content, forcing a recompile that regenerates .test.d with
the new .skel.h dependency captured by gcc -MMD.
Signed-off-by: Ricardo B. Marlière <rbm@suse.com>
Link: https://lore.kernel.org/r/20260602-selftests-bpf_misconfig-v12-5-27f898b3ba26@suse.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'tools')
| -rw-r--r-- | tools/testing/selftests/bpf/Makefile | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile index 49f6a5503e84..09de69a81112 100644 --- a/tools/testing/selftests/bpf/Makefile +++ b/tools/testing/selftests/bpf/Makefile @@ -726,11 +726,11 @@ $(TRUNNER_TEST_OBJS): $(TRUNNER_OUTPUT)/%.test.o: \ $(TRUNNER_TEST_OBJS:.o=.d): $(TRUNNER_OUTPUT)/%.test.d: \ $(TRUNNER_TESTS_DIR)/%.c \ $(TRUNNER_EXTRA_HDRS) \ + $$(BPFOBJ) | $(TRUNNER_OUTPUT) \ $(TRUNNER_BPF_SKELS) \ $(TRUNNER_BPF_LSKELS) \ $(TRUNNER_BPF_LSKELS_SIGNED) \ - $(TRUNNER_BPF_SKELS_LINKED) \ - $$(BPFOBJ) | $(TRUNNER_OUTPUT) + $(TRUNNER_BPF_SKELS_LINKED) ifeq ($(filter clean docs-clean emit_tests,$(MAKECMDGOALS)),) include $(wildcard $(TRUNNER_TEST_OBJS:.o=.d)) |