On Fri, 2024-07-12 at 17:48 +0000, Ihor Solodrai wrote:
[...]
> I've made a mistake when I removed $(TRUNNER_BPF_OBJS) as a
> prerequisite for $(TRUNNER_TEST_OBJS:.o=.d)
>
> I assumed it is covered by:
>
> $(TRUNNER_BPF_SKELS): %.skel.h: %.bpf.o $(BPFTOOL) | $(TRUNNER_OUTPUT)
>
> Apparently there are .bpf.o files for which skels are not generated,
> yet they are used in tests.
>
> Fixed in v3.
So, bear with me for a moment please.
We have 3 test_progs/smth.c files that depend on a few .bpf.o files at runtime,
but do not include skel files for those .bpf.o, namely:
- core_reloc.c
- verifier_bitfield_write.c
- pinning.c
And we fix this by adding a dependency:
$(TRUNNER_TEST_OBJS:.o=.d): ... $(TRUNNER_BPF_OBJS)
Which makes all *.test.d files depend on .bpf.o files.
Thus, if progs/some.c file is changed and `make test_progs` is requested:
- because *.test.d files are included into current makefile [1],
make invokes targets for *.test.d files;
- *.test.d targets depend on *.bpf.o, thus some.bpf.o is rebuilt
(but only some.bpf.o, dependencies for other *.bpf.o are up to date);
- case A, skel for some.c is not included anywhere (CI failure for v2):
- nothing happens further, as *.test.d files are unchanged *.test.o
files are not rebuilt and test_progs is up to date
- case B, skel for some.c is included in prog_tests/other.c:
- existing other.test.d lists some.skel.h as a dependency;
- this dependency is not up to date, so other.test.o is rebuilt;
- test_progs is rebuilt.
Do I understand the above correctly?
An alternative fix would be to specify additional dependencies for
core_reloc.test.o (and others) directly, e.g.:
core_reloc.test.o: test_core_reloc_module.bpf.o ...
(with correct trunner prefix)
What are pros and cons between these two approaches?
[1] https://make.mad-scientist.net/constructed-include-files/
