Subject: Re: [bpf PATCH v2] bpf: fix for lex/yacc build error with gcc-5

From: Jiri Benc <[email-masked]>
Date: Thu, 26 Apr 2018 10:43:17 +0200

On Wed, 25 Apr 2018 14:22:45 -0700, John Fastabend wrote:
> --- a/tools/bpf/Makefile
> +++ b/tools/bpf/Makefile
> @@ -76,6 +76,8 @@ $(OUTPUT)bpf_asm: $(OUTPUT)bpf_asm.o $(OUTPUT)bpf_exp.yacc.o $(OUTPUT)bpf_exp.le
>  	$(QUIET_LINK)$(CC) $(CFLAGS) -o $@ $^
>  
>  $(OUTPUT)bpf_exp.lex.c: $(OUTPUT)bpf_exp.yacc.c
> +$(OUTPUT)bpf_exp.yacc.o: $(OUTPUT)bpf_exp.yacc.c
> +$(OUTPUT)bpf_exp.lex.o: $(OUTPUT)bpf_exp.lex.c

Looks better than v1, the first dependency is important.

For some reason, I did not need the other two rules.

By the way, make invoked from tools/bpf/ has never really worked, even
before my patchset. This works correctly:

cd tools
make bpf

 Jiri