bpftool: fix make dependencies for vmlinux.h

[PATCH bpf-next] bpftool: fix make dependencies for vmlinux.h

Posted by Artem Savkov 1 year, 9 months ago

With pre-generated vmlinux.h there is no dependency on neither vmlinux
nor bootstrap bpftool. Define dependencies separately for both modes.
This avoids needless rebuilds in some corner cases.

Suggested-by: Jan Stancek <jstancek@redhat.com>
Signed-off-by: Artem Savkov <asavkov@redhat.com>
---
 tools/bpf/bpftool/Makefile | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/tools/bpf/bpftool/Makefile b/tools/bpf/bpftool/Makefile
index dfa4f1bebbb31..ba927379eb201 100644
--- a/tools/bpf/bpftool/Makefile
+++ b/tools/bpf/bpftool/Makefile
@@ -204,10 +204,11 @@ ifeq ($(feature-clang-bpf-co-re),1)
 
 BUILD_BPF_SKELS := 1
 
-$(OUTPUT)vmlinux.h: $(VMLINUX_BTF) $(BPFTOOL_BOOTSTRAP)
 ifeq ($(VMLINUX_H),)
+$(OUTPUT)vmlinux.h: $(VMLINUX_BTF) $(BPFTOOL_BOOTSTRAP)
 	$(QUIET_GEN)$(BPFTOOL_BOOTSTRAP) btf dump file $< format c > $@
 else
+$(OUTPUT)vmlinux.h: $(VMLINUX_H)
 	$(Q)cp "$(VMLINUX_H)" $@
 endif
 
-- 
2.44.0

Re: [PATCH bpf-next] bpftool: fix make dependencies for vmlinux.h

Posted by Quentin Monnet 1 year, 9 months ago

2024-05-13 12:27 UTC+0100 ~ Artem Savkov <asavkov@redhat.com>
> With pre-generated vmlinux.h there is no dependency on neither vmlinux
> nor bootstrap bpftool. Define dependencies separately for both modes.
> This avoids needless rebuilds in some corner cases.
> 
> Suggested-by: Jan Stancek <jstancek@redhat.com>
> Signed-off-by: Artem Savkov <asavkov@redhat.com>


Looks good, thank you.

Acked-by: Quentin Monnet <qmo@kernel.org>