On 8 December 2016 at 21:18, Wangnan (F) <wangn...@huawei.com> wrote: > > > On 2016/12/9 13:04, Wangnan (F) wrote: >> >> >> >> On 2016/12/9 10:46, Joe Stringer wrote: >> >> [SNIP] >> >>> diff --git a/tools/lib/bpf/Makefile b/tools/lib/bpf/Makefile >>> index 62d89d50fcbd..616bd55f3be8 100644 >>> --- a/tools/lib/bpf/Makefile >>> +++ b/tools/lib/bpf/Makefile >>> @@ -149,6 +149,8 @@ CMD_TARGETS = $(LIB_FILE) >>> TARGETS = $(CMD_TARGETS) >>> +libbpf: all >>> + >> >> >> Why we need this? I tested this patch without it and it seems to work, and >> this line causes an extra error: >> $ pwd >> /home/wn/kernel/tools/lib/bpf >> $ make libbpf >> ... >> gcc -g -Wall -DHAVE_LIBELF_MMAP_SUPPORT -DHAVE_ELF_GETPHDRNUM_SUPPORT >> -Wbad-function-cast -Wdeclaration-after-statement -Wformat-security >> -Wformat-y2k -Winit-self -Wmissing-declarations -Wmissing-prototypes >> -Wnested-externs -Wno-system-headers -Wold-style-definition -Wpacked >> -Wredundant-decls -Wshadow -Wstrict-aliasing=3 -Wstrict-prototypes >> -Wswitch-default -Wswitch-enum -Wundef -Wwrite-strings -Wformat -Werror >> -Wall -fPIC -I. -I/home/wn/kernel-hydrogen/tools/include >> -I/home/wn/kernel-hydrogen/tools/arch/x86/include/uapi >> -I/home/wn/kernel-hydrogen/tools/include/uapi libbpf.c all -o libbpf >> gcc: error: all: No such file or directory >> make: *** [libbpf] Error 1 >> >> Thank you. > > > It is not 'caused' by your patch. 'make libbpf' fails without > your change because it tries to build an executable from > libbpf.c, but main() is missing. > > I think libbpf should never be used as a make target. Your > new dependency looks strange.
Thanks for the feedback, I sent a patch to address this on top of perf/core: https://lkml.org/lkml/2016/12/9/518
