Daniel Borkmann <daniel@xxxxxxxxxxxxx> writes: > On 7/5/25 12:43 PM, Sam James wrote: >> Check the 'WERROR' variable and suppress adding '-Werror' if WERROR=0. >> This mirrors what tools/perf and other directories in tools do to >> handle >> -Werror rather than adding it unconditionally. > > Could you also add to the commit desc why you need it? Are there particular > warnings you specifically need to suppress when building under gentoo? Sure. In this case, it was https://bugs.gentoo.org/959293 where I think it's fixed by https://github.com/libbpf/libbpf/commit/715808d3e2d8c54f3001ce3d7fcda0844f765969 (and the corresponding commit in the kernel tree proper). Backporting that was a bit too big for our tastes. The real issue is just that -Werror when we have users who might be testing with in-development compilers or with alternative options results in a build failure when you didn't expect one. > >> Signed-off-by: Sam James <sam@xxxxxxxxxx> >> --- >> tools/lib/bpf/Makefile | 7 ++++++- >> 1 file changed, 6 insertions(+), 1 deletion(-) >> diff --git a/tools/lib/bpf/Makefile b/tools/lib/bpf/Makefile >> index 168140f8e646..9563d37265da 100644 >> --- a/tools/lib/bpf/Makefile >> +++ b/tools/lib/bpf/Makefile >> @@ -77,10 +77,15 @@ else >> CFLAGS := -g -O2 >> endif >> +# Treat warnings as errors unless directed not to >> +ifneq ($(WERROR),0) >> + CFLAGS += -Werror >> +endif > > Should we also add sth similar to tools/bpf/bpftool/Makefile and by default > enforce with -Werror with the option to disable? Yes, that sounds good to me, though I was nervous of stumbling onto a philosophical debate about -Werror and wasn't sure what y'all preferred :) I can send v2 with an updated commit message and this change. I'll wait a bit for further comments based on my two replies here. > >> # Append required CFLAGS >> override CFLAGS += -std=gnu89 >> override CFLAGS += $(EXTRA_WARNINGS) -Wno-switch-enum >> -override CFLAGS += -Werror -Wall >> +override CFLAGS += -Wall >> override CFLAGS += $(INCLUDES) >> override CFLAGS += -fvisibility=hidden >> override CFLAGS += -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 sam
