| Message ID | 1528477930-7342-4-git-send-email-yamada.masahiro@socionext.com |
|---|---|
| State | New |
| Headers | show |
| Series | net: bpfilter: clean-up build rules | expand |
On Sat, Jun 09, 2018 at 02:12:10AM +0900, Masahiro Yamada wrote: > It is an ugly hack to overwrite $(HOSTCC) with $(CC) to reuse the > build rules from scripts/Makefile.host. It should not be tedious > to write a build rule for its own. > > Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> > --- > > net/bpfilter/Makefile | 17 +++++++++++------ > net/bpfilter/{main.c => bpfilter_umh.c} | 0 > 2 files changed, 11 insertions(+), 6 deletions(-) > rename net/bpfilter/{main.c => bpfilter_umh.c} (100%) > > diff --git a/net/bpfilter/Makefile b/net/bpfilter/Makefile > index 39c6980..6571b30 100644 > --- a/net/bpfilter/Makefile > +++ b/net/bpfilter/Makefile > @@ -3,18 +3,23 @@ > # Makefile for the Linux BPFILTER layer. > # > > -hostprogs-y := bpfilter_umh > -bpfilter_umh-objs := main.o > -HOSTCFLAGS += -I. -Itools/include/ -Itools/include/uapi > -HOSTCC := $(CC) that is a hack indeed. I don't like it either, but see below. > - > ifeq ($(CONFIG_BPFILTER_UMH), y) > # builtin bpfilter_umh should be compiled with -static > # since rootfs isn't mounted at the time of __init > # function is called and do_execv won't find elf interpreter > -HOSTLDFLAGS += -static > +STATIC := -static > endif > > +quiet_cmd_cc_user = CC $@ > + cmd_cc_user = $(CC) -Wall -Wmissing-prototypes -O2 -std=gnu89 \ > + -I$(srctree) -I$(srctree)/tools/include/ \ > + -I$(srctree)/tools/include/uapi $(STATIC) -o $@ $< > + > +$(obj)/bpfilter_umh: $(src)/bpfilter_umh.c FORCE > + $(call if_changed,cc_user) Does this scale? Please see two top patches here: https://git.kernel.org/pub/scm/linux/kernel/git/ast/bpf.git/log/?h=ipt_bpf that add more meat to bpfilter and a lot more files. Recompiling all of them at once isn't nice either. This Makefile needs different .c -> .o rules for bpfilter_kern.c files that get compiled into kernel module and for the rest of umh files: main.c ctor.c init.c gen.c etc that need to be compiled .c -> .o differently. I don't see how to do it without ugly hacks in Makefile. In that sense HOSTCC = CC hack looked the least ugly to me that's why I went with it. Better ideas?
2018-06-09 5:52 GMT+09:00 Alexei Starovoitov <alexei.starovoitov@gmail.com>: > On Sat, Jun 09, 2018 at 02:12:10AM +0900, Masahiro Yamada wrote: >> It is an ugly hack to overwrite $(HOSTCC) with $(CC) to reuse the >> build rules from scripts/Makefile.host. It should not be tedious >> to write a build rule for its own. >> >> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> >> --- >> >> net/bpfilter/Makefile | 17 +++++++++++------ >> net/bpfilter/{main.c => bpfilter_umh.c} | 0 >> 2 files changed, 11 insertions(+), 6 deletions(-) >> rename net/bpfilter/{main.c => bpfilter_umh.c} (100%) >> >> diff --git a/net/bpfilter/Makefile b/net/bpfilter/Makefile >> index 39c6980..6571b30 100644 >> --- a/net/bpfilter/Makefile >> +++ b/net/bpfilter/Makefile >> @@ -3,18 +3,23 @@ >> # Makefile for the Linux BPFILTER layer. >> # >> >> -hostprogs-y := bpfilter_umh >> -bpfilter_umh-objs := main.o >> -HOSTCFLAGS += -I. -Itools/include/ -Itools/include/uapi >> -HOSTCC := $(CC) > > that is a hack indeed. I don't like it either, but see below. > >> - >> ifeq ($(CONFIG_BPFILTER_UMH), y) >> # builtin bpfilter_umh should be compiled with -static >> # since rootfs isn't mounted at the time of __init >> # function is called and do_execv won't find elf interpreter >> -HOSTLDFLAGS += -static >> +STATIC := -static >> endif >> >> +quiet_cmd_cc_user = CC $@ >> + cmd_cc_user = $(CC) -Wall -Wmissing-prototypes -O2 -std=gnu89 \ >> + -I$(srctree) -I$(srctree)/tools/include/ \ >> + -I$(srctree)/tools/include/uapi $(STATIC) -o $@ $< >> + >> +$(obj)/bpfilter_umh: $(src)/bpfilter_umh.c FORCE >> + $(call if_changed,cc_user) > > Does this scale? > Please see two top patches here: > https://git.kernel.org/pub/scm/linux/kernel/git/ast/bpf.git/log/?h=ipt_bpf > that add more meat to bpfilter and a lot more files. Oh, I just thought main.c was the only user-program file. > Recompiling all of them at once isn't nice either. Indeed. It should be able to compile .c -> .o separately. > This Makefile needs different .c -> .o rules for bpfilter_kern.c files > that get compiled into kernel module and for the rest of umh files: > main.c ctor.c init.c gen.c etc > that need to be compiled .c -> .o differently. > I don't see how to do it without ugly hacks in Makefile. > In that sense HOSTCC = CC hack looked the least ugly to me that's > why I went with it. > Better ideas? I will think about it after your patches land. I will drop this for now. -- Best Regards Masahiro Yamada
diff --git a/net/bpfilter/Makefile b/net/bpfilter/Makefile index 39c6980..6571b30 100644 --- a/net/bpfilter/Makefile +++ b/net/bpfilter/Makefile @@ -3,18 +3,23 @@ # Makefile for the Linux BPFILTER layer. # -hostprogs-y := bpfilter_umh -bpfilter_umh-objs := main.o -HOSTCFLAGS += -I. -Itools/include/ -Itools/include/uapi -HOSTCC := $(CC) - ifeq ($(CONFIG_BPFILTER_UMH), y) # builtin bpfilter_umh should be compiled with -static # since rootfs isn't mounted at the time of __init # function is called and do_execv won't find elf interpreter -HOSTLDFLAGS += -static +STATIC := -static endif +quiet_cmd_cc_user = CC $@ + cmd_cc_user = $(CC) -Wall -Wmissing-prototypes -O2 -std=gnu89 \ + -I$(srctree) -I$(srctree)/tools/include/ \ + -I$(srctree)/tools/include/uapi $(STATIC) -o $@ $< + +$(obj)/bpfilter_umh: $(src)/bpfilter_umh.c FORCE + $(call if_changed,cc_user) + +targets += bpfilter_umh + $(obj)/bpfilter_umh_blob.o: $(obj)/bpfilter_umh obj-$(CONFIG_BPFILTER_UMH) += bpfilter.o diff --git a/net/bpfilter/main.c b/net/bpfilter/bpfilter_umh.c similarity index 100% rename from net/bpfilter/main.c rename to net/bpfilter/bpfilter_umh.c
It is an ugly hack to overwrite $(HOSTCC) with $(CC) to reuse the build rules from scripts/Makefile.host. It should not be tedious to write a build rule for its own. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> --- net/bpfilter/Makefile | 17 +++++++++++------ net/bpfilter/{main.c => bpfilter_umh.c} | 0 2 files changed, 11 insertions(+), 6 deletions(-) rename net/bpfilter/{main.c => bpfilter_umh.c} (100%) -- 2.7.4