2025-03-10 22:20 UTC+0800 ~ Jiayuan Chen <jiayuan.chen@xxxxxxxxx> > This commit adds the -Wformat-signedness compiler flag to detect and > prevent printf format errors, where signed or unsigned types are > mismatched with format specifiers. This helps to catch potential issues at > compile-time, ensuring that our code is more robust and reliable. With > this flag, the compiler will now warn about incorrect format strings, such > as using %d with unsigned types or %u with signed types. > > Signed-off-by: Jiayuan Chen <jiayuan.chen@xxxxxxxxx> Acked-by: Quentin Monnet <qmo@xxxxxxxxxx> Thanks for that. Have you looked into enabling the flag along with the other EXTRA_WARNINGS in tools/scripts/Makefile.include? It would be ideal to have it there, but I suppose it raises too many warnings across tools/? (I didn't try myself.) No objection to taking it in bpftool only. > --- > tools/bpf/bpftool/Makefile | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/tools/bpf/bpftool/Makefile b/tools/bpf/bpftool/Makefile > index dd9f3ec84201..d9f3eb51a48f 100644 > --- a/tools/bpf/bpftool/Makefile > +++ b/tools/bpf/bpftool/Makefile > @@ -71,7 +71,7 @@ prefix ?= /usr/local > bash_compdir ?= /usr/share/bash-completion/completions > > CFLAGS += -O2 > -CFLAGS += -W -Wall -Wextra -Wno-unused-parameter -Wno-missing-field-initializers > +CFLAGS += -W -Wall -Wextra -Wformat-signedness -Wno-unused-parameter -Wno-missing-field-initializers Nit: This line is becoming long enough that I'd consider moving each flag to its own line, for better reading: CFLAGS += -W CFLAGS += -Wall CFLAGS += -Wextra CFLAGS += -Wformat-signedness ... > CFLAGS += $(filter-out -Wswitch-enum -Wnested-externs,$(EXTRA_WARNINGS)) > CFLAGS += -DPACKAGE='"bpftool"' -D__EXPORTED_HEADERS__ \ > -I$(or $(OUTPUT),.) \
