2022-02-18 18:14 UTC+0200 ~ Nikolay Borisov <nborisov@xxxxxxxx> > > > On 18.02.22 г. 18:08 ч., Quentin Monnet wrote: >> 2022-02-17 14:04 UTC+0200 ~ Nikolay Borisov <nborisov@xxxxxxxx> >>> Sometime it can be useful to haul around a statically built version of >>> bpftool. Simply add support for passing STATIC=1 while building to build >>> the tool statically. >>> >>> Signed-off-by: Nikolay Borisov <nborisov@xxxxxxxx> >>> --- >>> >>> Currently the bpftool being distributed as part of libbpf-tools under >>> bcc project >>> is dynamically built on a system using GLIBC 2.28, this makes the >>> tool unusable on >>> ubuntu 18.04 for example. Perhaps after this patch has landed the >>> bpftool in bcc >>> can be turned into a static binary. >>> >>> tools/bpf/bpftool/Makefile | 4 ++++ >>> 1 file changed, 4 insertions(+) >>> >>> diff --git a/tools/bpf/bpftool/Makefile b/tools/bpf/bpftool/Makefile >>> index 83369f55df61..835621e215e4 100644 >>> --- a/tools/bpf/bpftool/Makefile >>> +++ b/tools/bpf/bpftool/Makefile >>> @@ -13,6 +13,10 @@ else >>> Q = @ >>> endif >>> >>> +ifeq ($(STATIC),1) >>> + CFLAGS += --static >>> +endif >>> + >>> BPF_DIR = $(srctree)/tools/lib/bpf >>> >>> ifneq ($(OUTPUT),) >>> -- >>> 2.25.1 >>> >> >> Why not just pass the flag on the command line? I don't think the >> Makefile overwrites it: >> >> $ CFLAGS=--static make > > Yeah, this also works, I initially thought that overriding a variable on > the command line would require having the override directive in the > makefile but apparently is not the case. I guess this patch can be > scratched. You'd need something if the Makefile was initialising the variable, with something like "CFLAGS = -O2" or "CFLAGS := -O2". But bpftool's Makefile always uses "CFLAGS += ...", meaning it appends to the current value, so you can pass whatever you want from the command line, as long as it doesn't get overwritten by another flag (for example, passing "-O0" would not work I think, since we add "-O2" in the Makefile).
